FEDERAL COURT OF AUSTRALIA

Motorola Solutions, Inc. v Hytera Communications Corporation Ltd (Liability) [2022] FCA 1585

ORDERS

THE COURT ORDERS THAT:

1.    The parties confer and, if possible, bring in a minute of order giving effect to these reasons by close of business on 13 February 2023 or, if no agreement be possible, provide a minute of the orders for which each contends by the same date.

2.    Order 1 made by the Court on 25 November 2022 be set aside but only prospectively from the time of the making of these orders.

3.    Order 8 of the orders made on 22 July 2020 remain in force until 1 March 2023.

4.    The matter be stood over for further directions at 9.30 am on 15 February 2023.

5.    Pursuant to ss 37AF(1)(b) and 37AG(1)(a) of the Federal Court of Australia Act 1976 (Cth), until further order of the Court, and subject to any restrictions imposed by the confidentiality regime agreed between the parties dated 10 April 2018 (‘Confidentiality Regime’) and/or the confidentiality regime agreed between the parties dated 24 May 2019 (‘MSI Code Confidentiality Regime’), access to and disclosure (by publication or otherwise) of the unredacted text of the reasons for judgment delivered today be restricted to the parties and their legal representatives, and those persons to whom access is allowed under the terms of the Confidentiality Regime or the MSI Code Confidentiality Regime.

6.    Nothing in Order 5 or any other earlier order of the Court prevents any party from publishing the covering pages of these reasons for judgment up to and including these orders or paragraphs [1]-[8] of the reasons or the Associate’s Certificate appearing at the end of the reasons after paragraph [2315].

7.    By 27 January 2023, the legal representatives for the Applicant and the legal representatives for the Respondents exchange highlighted versions of the reasons for judgment identifying the parts of the reasons that are claimed to contain information confidential to their respective clients for redaction.

8.    By 10 February 2023, the legal representatives for the parties confer on the proposed redactions and, if the parties are able to agree on the proposed redactions, provide to chambers an agreed form of the reasons for judgment with the proposed redactions highlighted, together with an agreed redacted form of the reasons for judgment that is suitable for publication.

9.    In the event the parties are unable to agree on the proposed redactions, by 14 February 2023, the legal representatives for the parties provide chambers with:

(a)    a version of the reasons for judgment which identifies the redactions which have been agreed and those which are in dispute; and

(b)    a short written submission addressing the areas of disagreement.

Note:    Entry of orders is dealt with in Rule 39.32 of the Federal Court Rules 2011.

REASONS FOR JUDGMENT

PERRAM J:

I    INTRODUCTION

1    Motorola Solutions Inc (‘Motorola’) sues Hytera Communications Corporation Ltd (‘Hytera’) and its Australian subsidiary, Hytera Communications (Australia) Pty Ltd (‘Hytera Australia’) for patent and copyright infringement. The alleged infringements relate to digital mobile radios (‘DMR’). DMRs can be mobile (e.g. affixed to a vehicle which moves) or portable (e.g. carried around by a person). An individual DMR can communicate directly with another DMR without an intermediary, and when it does so, the two devices are said to be communicating in ‘direct mode’. However, they also are frequently deployed with fixed base stations, or ‘repeaters’, through which they communicate with each other and by which means their range is extended.

2    Motorola alleges that Hytera’s DMRs infringe three of its patents. These patents relate to a pre-existing technology which permits a frequency band within the radio spectrum (a channel) to be divided into timeslots so that more than one person may use the same channel at the same time. This technology is known as Time Division Multiple Access or, more commonly, ‘TDMA’. The three patents are methods which refine the efficiency of TDMA. The first patent, No. 2005275355 (‘355 Patent’), is a method and system which improves the time taken to scan a channel to determine whether there is activity on that channel. The second patent, No. 2009298764 (‘764 Patent’), is a method for efficiently synchronising to a desired timeslot. The third patent, No. 2006276960 (‘960 Patent’), is a method and system for accessing a base station which has been de-keyed. I will refer to the 355 Patent, the 764 Patent and the 960 Patent collectively where necessary as ‘the Patents’.

3    Motorola alleges that Hytera imported into Australia DMRs which infringed the methods of the three patents and sues for secondary infringement. Hytera disputes Motorola’s construction of each of the Patents and contends in each case that if construed as Motorola suggests, each patent is invalid for various reasons. I have concluded that Motorola’s construction of the 355 Patent is correct and that the challenges to its validity fail. I have concluded therefore that Motorola’s infringement case in relation to the 355 Patent largely succeeds although I have accepted that Hytera did not infringe the patent after November 2019 when it took steps to ensure that existing mobile stations were upgraded before reprogrammed base stations were supplied to end users (the upgrade removing the infringement). In the course of reaching this conclusion, I have rejected Hytera’s submission that any infringement was required by the relevant European Telecommunications Standards Institute (‘ETSI’) standard. I have rejected Motorola’s infringement case on the 764 Patent. Motorola’s construction of that patent is not correct. If it had been correct, I would have concluded that the patent was invalid as it would not have been fairly based. I have also rejected Motorola’s infringement case on the 960 Patent. Although Motorola’s construction of the patent is correct, the patent is invalid for want of an inventive step. In the case of all three patents, I have rejected Hytera’s contention that no manner of manufacture is involved. I have rejected Motorola’s claim for additional damages for patent infringement.

4    The copyright suit relates to the firmware which was installed on Hytera devices imported into Australia. Motorola alleges that this firmware (which is in binary code) was derived from object code which had been compiled from Hytera’s source code. That source code was written in the computer languages C and C++. Much of Hytera’s source code has been lost. Motorola alleges that Hytera developed its source code by copying Motorola’s source code. This was said to have been done in 2008 when several former employees of Motorola went across to Hytera to help it develop its DMR products. Motorola says that 11 of its computer programs have been copied by Hytera. Motorola’s proof of this was hindered by the fact that much of the Hytera source code has vanished. In relation to some of the vanished source code, the object code compiled from it was available. Motorola sought to disassemble this object code back into assembly language and to prove by these indirect means that the missing Hytera source code had been copied from the Motorola source code. The proof of these matters was protracted.

5    I have concluded that Motorola has succeeded in proving that Hytera copied a substantial part of 6 of the 11 computer programs and is liable for copyright infringement. Motorola also alleged that Hytera’s actions constituted a substantial industrial theft. I have accepted this submission and the allied contention that Motorola is entitled to additional damages on account of the flagrancy of the infringements.

6    The programs which Motorola alleges were copied by Hytera consisted of source code which was compiled into firmware to be installed on its DMR devices. The development of this firmware was a lengthy and complicated process of software engineering involving a large number of engineers. The entire undertaking was known as ‘Project Matrix’. Taking its cue from the movie The Matrix, the individual projects within Project Matrix were known as Project Neo, Project Morpheus and Project Cypher. As the Oracle observed to Neo in the third film, The Matrix Revolutions, ‘everything that has a beginning has an end’. Despite some misgivings along the way, these reasons will eventually affirm the truth of this observation, although not until paragraph [2315].

7    The trial was conducted in two phases with the patent allegations being heard before the copyright allegations. In consequence, there are two sets of transcripts and two separate court books. The reasons for judgment dealing with the patent allegations (apart from additional damages) refer only to the transcript and court book used in the patent phase. The reasons for judgment dealing with the copyright allegations refer principally to the copyright transcript and court book but there are occasional references to the patent materials. Where this occurs, I note it. These reasons were published on 23 December 2022 in an unredacted form subject to certain non-publication orders and confidentiality arrangements which restrict its publication due to the potential presence of trade secrets in the reasons for judgment. As at 23 December 2022, only the first eight paragraphs will be publicly available. The full reasons for judgment, if necessary subject to some redaction, will be published in the New Year once the parties have had an opportunity to consider whether any redaction is necessary.

8    I deal first with the patent allegations and then the copyright allegations. In order to understand the patent allegations, it is necessary to understand two-way radio communications and, more particularly, TDMA. To these dry matters I now turn.

II    BACKGROUND TO TWO-WAY RADIO COMMUNICATIONS

9    To understand the issues which arise in the patents suit, it is necessary to have a grasp of the electronic engineering underpinning two-way radio communications. The purpose of this section is to equip the reader with sufficient technical understanding to grapple with the issues which divide the parties and to understand the technical context in which the inventions which are the subject of the Patents are immersed. Where necessary, I will also discuss some of the industry standards which operated, as a prelude to the subsequent discussion of the common general knowledge (‘CGK’). Some aspects of this discussion are also relevant to Motorola’s copyright infringement allegations in relation to its source code.

10    Mr Kuhrt provided a high-level overview of two-way radio communications technology in his first affidavit at §§70-196 which I have found useful. Mr Kuhrt’s evidence was directed at information which he believed would have been well-known and generally accepted by engineers working in the field of two-way radio communications in Australia as at 26 July 2004, the priority date of the earliest patent in suit, the 355 Patent. The following discussion is largely taken from his evidence and is supplemented where necessary with the evidence of Professor Rangan. It has a particular emphasis on the three matters which are the subject of the Patents: radio scanning, repeater de-keying and re-keying, and synchronisation methods.

WHAT ARE RADIO COMMUNICATIONS AND HOW DO THEY WORK?

11    Radio is a method of transmitting electromagnetic energy across distance without using a direct, wired connection. The electromagnetic energy takes the form of radio waves which have a certain frequency. Radio waves are generated and sent out through a transmitter and are then received by a radio receiver using antennas. Depending upon their length, radio waves may travel in three ways: (i) by line of sight; (ii) by being reflected off of buildings or other objects, in which case the communications will not travel beyond the horizon; and (iii) by being reflected off of the ionosphere, in which case they can return to earth beyond the horizon. Different radio frequencies (‘RF’) are used for these different reflective requirements.

12    Radio communications can be transmissions of audio (i.e. analogue transmissions) or of data (i.e. digital transmissions). Where a transmission is an analogue transmission, the whole of the voice transmission can be sent and decoded without any additional information being transmitted. In practical terms, this means that the radio signal carries nothing but the voice transmission. By contrast, where a digital communication is involved, the decoding of the message requires the use of what are called ‘overheads’. Overheads are the bits of digital information that are not associated with the substantive transmission, or what is usually referred to as the ‘payload’. Digital transmissions are thus made up of two kinds of information: information which comprises the overhead, and information which comprises the payload.

13    Two of the Patents in this case are directly concerned with overheads and a desire to reduce them and thereby make more of the signal available for the payload. One of the overheads in a digital communication arises from the need to achieve what is called ‘synchronisation’ between the devices which is achieved using a synchronisation pattern (I explain this more fully below). Another relates to the scanning of channels which involves the use of information to identify the devices to which a payload is to be delivered. This kind of information is referred to as ‘control information’. The more of the radio transmission that is consumed by transmitting control information, the less of it is available to transmit payload.

The Radio Spectrum

14    The radio portion of the electromagnetic spectrum (which radio communications are transmitted on) is divided into three sub-categories known as ‘frequency bands’. These bands are the: (i) high frequency band (‘HF’) (3,000 kHz to 30 MHz); (ii) very high frequency band (‘VHF’) (30 MHz to 300 MHz); and (iii) ultra-high frequency band (‘UHF’) (300 MHz to 3 GHz). Each of these bands is further separated into bandwidth channels which radio users use to transmit communications. These channels reflect the frequency range occupied by a carrier signal and are separated by a space known as ‘channel spacing’. The size of the bandwidth channel and the size of the channel spacing between each channel is determined by a regulatory authority which in Australia is the Australian Communications and Media Authority (‘ACMA’). In 1999, ACMA determined that two-way radios would use channel bandwidths of 12.5 kHz. What this means is that each channel may occupy a range of frequencies in the radio spectrum which are no wider than 12.5 kHz. The size of this bandwidth limits the number of frequencies that can be defined inside a relevant band.

15    Generally, the wider the channel bandwidth, the better the audio fidelity or the higher the data rate will be. In other words, the larger the channel bandwidth is, the better quality the radio communication will be. For example, whilst the bandwidth for two-way radio communications is 12 kHz, the bandwidth for commercial frequency modulation (‘FM’) broadcasting stations is set at 100 kHz. In general, therefore, this creates a problem whereby the interests of the regulator (here, ACMA) and radio users are opposed. Whereas ACMA wishes to reduce the bandwidth of a channel, thereby increasing the number of operators that might transmit, radio users desire a greater bandwidth (for greater audio quality) which reduces the number of possible users.

The Components of Radio Devices

16    A two-way radio is a device that can both receive and transmit signals from other radios operating on the same RF. There are two kinds of two-way radio devices: half-duplex devices and full-duplex devices. A half-duplex radio is one which permits the user to talk or to listen but not to do both at the same time. A full-duplex radio, by contrast, has the ability to send and receive transmissions at the same time. It does so by sending transmissions on one frequency and receiving them on another.

17    In the case of a half-duplex two-way radio, the user presses a ‘Push-To-Talk’ (‘PTT’) button which activates the transmitter. When the PTT button is not pressed, the device’s radio receiver is activated. Half-duplex radios may also function by using what is referred to as ‘simplex communication’. Where this occurs, the transmission and reception occurs on a single RF. In other words, the radio switches between the ‘transmit’ and ‘receive’ functions, transmitting on one frequency and then switching to receive any incoming transmissions using the same frequency.

18    To be able to transmit and receive at the same time, full-duplex radios may use two different frequencies. Typically, this means that one frequency is assigned for the radio to transmit and another is assigned to receive communications. Together, the two frequencies are known as a ‘frequency pair’ or a ‘physical channel’. Alternatively, a full-duplex radio may use what are called frequency sharing methods. I discuss these further below, but in a digital system this involves breaking the communications up into digital packages and transmitting the packages sufficiently frequently such that the underlying process is not audible.

Terminal Equipment

19    Mobile stations are typically vehicle based installations that allow for communication to other local terminal equipment (e.g. between police cars). These are also referred to as ‘radios’ or ‘subscriber units’. They may communicate in either of two modes: (i) direct mode; or (ii) ‘repeater mode’. A direct mode transmission occurs between two mobile stations (without the use of a repeater, which I discuss below) and usually takes place on the same transmit and receive frequencies (i.e. with each radio switching between transmitting and receiving communications in the fashion described above at [17]). A direct mode communication is possible so long as both mobile station users are not too far apart and there is no obstruction between the sender of the communication and the receiver.

20    Portable terminals are relatively low power but more readily moveable versions of mobile stations often worn on the body, i.e. walkie-talkies.

Repeater Equipment

21    Repeaters, which are also referred to as ‘base stations’, are devices which relay transmissions from terminal equipment, thus extending the coverage of those terminals. They are typically located above terminals (such as on top of a mountain or building) and utilise a hard-wired power source. Thus, where a repeater is used, the sender of the communication will transmit the message from their terminal and once the transmission reaches the base station, the base station will then repeat the message to the intended receiver. In a trunked system, a repeater also repeats the transmissions which it receives from a control station. I return to the topic of trunking below.

22    Relatively simple two-way radio systems only include a single repeater. Multiple repeaters, however, may be interconnected to increase the coverage area (known as a ‘cell’) and to enable direct links to control stations. Repeaters typically receive and transmit on two different RFs, known as the ‘uplink’ and the ‘downlink’. Terminals transmit information (such as voice calls) through the uplink towards the repeater. The repeater then retransmits or repeats the information through the downlink towards another repeater or terminal. In its most simple form, a repeater is therefore two terminal devices connected together, with one operating as the uplink and one operating as the downlink. This is a schematic of a single repeater two-way radio system:

23    The downlink is essential to the processes of ‘de-keying’ and ‘re-keying’ which are central to the 960 Patent. In many two-way radio systems, the repeater is designed to ‘de-key’ after a transmission. When a repeater de-keys, it turns off the downlink. This means that the repeater cannot transmit information using the downlink unless it ‘re-keys’. Further, terminals listening to the repeater’s downlink frequency will not receive transmissions from that repeater. A common reason why a repeater will de-key is because there is no active terminal using the repeater’s cell. Since the radio spectrum is a limited and shared resource, repeaters are often programmed to de-key in order to ensure that they are not powered on when they are not in use and to allow other repeaters to use the frequency.

24    Repeaters often have a fixed timer (e.g. 10 sec) which starts when the repeater detects that there is no activity on the repeater’s uplink frequency. This will occur when there is no transmission being sent from any of the terminal devices. This timer is often referred to as the ‘hangtimer’. One of the purposes of the hangtimer is to ensure that the recipient has sufficient time to respond to a communication before the repeater de-keys. When the hangtimer expires, the repeater de-keys.

25    If a mobile station wants to utilise a de-keyed repeater for transmissions, it must first wait for the repeater to ‘re-key’. When the repeater re-keys, it reactivates the downlink and can send outgoing transmissions again. Although a de-keyed repeater’s downlink is deactivated, its uplink is still monitored and is able to receive transmissions. This allows a de-keyed repeater to receive messages from terminals, enabling it to re-key. The process of re-keying, however, can take time and delay transmissions. This can be a problem for users (such as a member of the emergency services) who need to relay a communication quickly.

Control Stations and Control Channels

26    Control stations facilitate communication and signalling to remote terminal equipment. They may be positioned in a control centre or a depot. A simple control station may consist of a speaker, a microphone and a PTT switch. A more complex control station may include several networked computers and remotely accessible data bases. Control stations are a common feature of trunked systems which are discussed below at [88].

27    A control channel is a channel in a trunking system where network access is requested and assigned. They are used by radio users to be assigned to a traffic channel to begin a voice transmission.

Modems

28    Modems facilitate the transfer of data using RFs. Prior to July 2004, some analogue two-way radio systems included modems as an optional component. This is because their presence allowed analogue systems to transmit data (as opposed to just voice) over the analogue signal. By allowing data to be transmitted in this way, control information could therefore be transmitted even though the system was not digital. Examples of the kind of control information that could be transmitted included: information identifying a particular terminal (terminal identification information), information identifying groups of terminals to be included in a communication (talkgroup identification information), and information as to which channels were to be used for what (channel allocation information). The word ‘terminal’ is used interchangeably with ‘subscriber unit’ or ‘mobile station’.

29    In analogue systems, modems were a physical component of the radio device (i.e. hardware in the terminals and the repeaters) which turned converted data into an analogue (that is, audio) signal. In digital systems, however, modem functionality was incorporated into the software of the devices and no physical modem was needed.

30    An early example of an analogue two-way radio system which used modems to transmit data was the system used by taxi providers. The address information for jobs was transmitted to taxi drivers from a control centre as data over the analogue network which, I infer, was otherwise used to carry voice signals.

Two-Way Radio Functionality

31    Cellular communication systems such as mobile phones are designed for one-to-one communications and so are usually used by individual consumers. By contrast, two-way radios are designed to be used by professionals in sectors such as government, industrial, and emergency services and so are focussed on group call communications which are also known as one-to-many communications. As a result, two-way radios utilise a feature known as ‘talkgroups’ (discussed in more detail below at [33]). Mobile phones are typically smaller, have lower power levels and are full-duplex devices (i.e. they can communicate and receive at the same time). Two-way radios are larger devices with a relatively higher power level and may be full-duplex or half-duplex (in which case, as explained above, they cannot transmit and receive at the same time).

32    As already noted, two-way radios can engage in direct mode between themselves, or in repeater mode via a repeater. Mobile phones do not have a direct mode and only communicate through network infrastructure.

Talkgroups

33    A talkgroup is a way of organising multiple individual radio devices into groups of users who can all communicate with each other. Each talkgroup has its own ‘group identity’ which is programmed into the memory of each individual radio device. When a radio device that is a member of a specific talkgroup transmits, all the other members of the talkgroup are able to hear and respond to that transmission. The use of talkgroups allows for private communications between members of a particular talkgroup by excluding radio users that are not part of that group. It also facilitates effective communication, in that one user can communicate to a group with a single transmission.

34    For example, an individual firefighter who is based in Richmond in Victoria may want to communicate with a number of different groups of people depending on the situation:

35    To do so, the radio device that the firefighter uses might be assigned to different talkgroups. One talkgroup to which the firefighter is assigned may include all emergency services within 15 km of where the firefighter is based in Richmond (i.e. Melbourne CBD Emergency Services in the above diagram). This talkgroup would allow the firefighter to broadcast communications to ambulances and police officers in the nearby region. The firefighter could also be assigned to a talkgroup which is limited to firefighters from Richmond Fire Station (i.e. Station 10). This could allow the firefighter to talk and receive information from his station in private. More narrowly, the firefighter could be assigned to a talkgroup which is only his or her unit (i.e. Company 6) from the Richmond Fire Station. This would allow the firefighter to communicate with his or her team while out in the field without needing to broadcast to the entire station or to all emergency services.

Scanning

36    Mobile and portable radio users tune into specific channels in order to transmit or receive communications. Users can select a channel either:

(a)    manually (usually through a dial or buttons) by selecting an appropriate channel; or

(b)    by using the radio automatically to scan channels.

37    The process of scanning involves the receiver radio searching multiple channels (known as a ‘scan group’) to find a ‘valid’ transmission. A scan group consists of a group of frequencies that may be of interest and is stored in the memory of the radio. When the radio determines that it has found a valid transmission, it will stop and lock onto that channel and then send the communication to the radio’s speaker. A valid transmission is a communication which meets specific conditions, such as having certain talkgroup or address information. The conditions which will make a transmission valid are programmed into the radio device. If the receiver radio decodes the message and identifies that all of the relevant conditions are present, the transmission will be deemed valid and will be broadcast through the speaker. If the transmission does not meet all of the programmed conditions, however, it will be ignored. In the example of the firefighter above, for instance, the radio device could be programmed such that a transmission addressed to one or more of the three talkgroups would be a valid transmission.

38    There are various ways to program a radio’s scanning capabilities. One way in which a radio’s scanning capabilities might be programmed is called ‘priority scanning’, which enables the radio to scan important channels more frequently. Automatic scanning, such as priority scanning, can be advantageous because it can take time for a user manually to select channels and users may miss transmissions if they are on the wrong channel. Various systems existed for automatic scanning prior to the priority date for the 355 Patent which is concerned with scanning.

Different Types of Two-Way Radios

39    Two-way radio systems are generally split into analogue and digital systems. The main difference between them is the way that signals are transmitted and received. Analogue radio systems use electrical signals which, at least conceptually, resemble sound waves to deliver voice audio over an RF. Digital radio systems, by contrast, process sounds into patterns of numbers which are then transmitted over an RF. Digital two-way radios can allow users to transmit data as well as audio. They are also more secure.

Analogue Two-Way Radios

40    Early two-way radio systems transmitted voice messages using analogue methods over RFs. Communication was either direct from one terminal to another on a simplex channel (that is, on a single frequency) or it was transmitted between terminals via a repeater on different transmit and receive frequencies.

41    Without the inclusion of the repeater, the coverage of a radio system is dependent on the power of the terminal. Since terminals are often portable and therefore powered by a battery, the power of early terminals was relatively low. However, since early analogue two-way radio systems could be used in both direct mode and repeater mode (that is, with or without a repeater), simple analogue two-way radio systems often included a single repeater to relay communications between connected terminals. The coverage of such a system is restricted by the power of the single repeater. This type of system was very common in Australia before the 1980s.

42    Larger two-way radio systems include multiple repeaters that enable the system to cover a larger area. While this type of system allowed for extended coverage, a problem was that all of the connected repeaters were required for a single transmission. This meant that only one transmission could take place using connected repeaters in the system at a time. This problem is illustrated in the following diagram:

Scanning in Analogue Two-Way Radio Systems before 26 July 2004

43    Early two-way radio systems required radio users (such as the user of a mobile station in a vehicle) manually to change the channel to scan the system for relevant transmissions. This meant that when a user was moving around they would need to know the channel which was associated with the closest repeater and then select that channel on the mobile station in order to receive the transmission.

44    Automatic scanning and voting functionality was then developed in around the 1980s to allow for users moving between different repeaters automatically to receive communications from different repeaters. In early analogue systems, this was achieved by a list of frequencies (each of which was associated with a different repeater) being saved in the memory of the terminal devices. When set to scan automatically, the terminal device would then step through the list of frequencies and lock onto each to determine if a transmission was taking place.

45    A problem with this automatic scanning methodology, however, was that there was no assessment of signal strength when the terminal device stepped through the list of frequencies. As a result, terminals often locked onto a repeater that was not the closest repeater to them, with the consequence that they had low signal strength.

46    Automatic voting was thus developed to ensure that signal strength was taken into account when a terminal automatically scanned RFs. Automatic voting was similar to automatic scanning in that the terminal would automatically scan through a list of frequencies saved to memory in the terminal. However, automatic voting required the terminal device to assess the signal strength of each frequency stored in memory in the terminal before deciding which frequency (i.e. which repeater) to lock onto. This type of system often included a control station that was independent of the repeaters. That control station would re-key the repeaters every minute or so to produce a burst of energy for a length of time that was sufficient for each terminal to complete the automatic voting function and record their local site (i.e. the local repeater with the strongest signal strength).

47    Techniques were also developed before 26 July 2004 that enabled analogue terminals automatically to scan frequencies for specific types of communications (e.g. communications to a specific talkgroup). One example of this kind of technique was what was known as the ‘Code Tone-Coded Squelch System’ (‘CTCSS’). The CTCSS adds a low frequency tone to a voice communication. Terminals included in their memory a list of CTCSS tones that were associated with, for example, a talkgroup. This enabled the terminals to listen for a specific CTCSS tone. If the tone for a talkgroup which was saved to the terminal’s memory was heard on a channel while it was automatically scanning, then the terminal would stay on the channel. Otherwise, the terminal would continue scanning the other channels saved in its scan list. As will become clear, the concepts of scanning and staying on a channel are important to the 355 Patent.

48    A well-known problem with both automatic scanning and automatic voting in early analogue two-way radio systems was the length of time that it took for a terminal to complete the process. This limitation was a physical limitation which was inherent in analogue two-way radio systems. It was caused by the fixed amount of time that it took the terminal to perform the automatic scanning and automatic voting processes because it involved a number of steps. First, the radio would find an RF carrier. Secondly, using the example of CTCSS tones (although other methods might be used), it would decode the CTCSS in a hardware chip or in software. Thirdly, it would ‘qualify’ the channel and then, if all the relevant criteria were met, it would remain on the channel to start receiving communications. By ‘qualify’, I understood Mr Kuhrt to mean that, having detected the relevant CTCSS tone, the device had to be sure that it had done so and that what had occurred was not a random appearance of a tone frequency. This is consistent with his explanation that automatic scanning and voting in analogue two-way radios required the device to receive a certain number of radio wave cycles before the device could qualify the radio signal. As a result of the CTCSS tone being of such a low frequency, the time spent scanning and voting was determined by the period of the waveforms. For example, a two-way radio might have to wait for five cycles of the CTCSS waveform before it could complete the process and start receiving transmissions. Mr Kuhrt thought that this problem was a well-known problem prior to the late 1980s which I accept. One solution to the problem was to limit the number of frequencies to be scanned.

De-keying and Re-keying in Analogue Two-Way Radios Prior to 26 July 2004

49    Prior to 26 July 2004, analogue repeaters included a hangtimer which prevented a repeater from de-keying immediately after a transmission. This hangtimer ensured that the recipient had sufficient time to respond before the repeater de-keyed (as above, where a repeater de-keyed it would result in the repeater releasing the downlink frequency to allow for other system users to begin a transmission).

50    Mr Kuhrt then gave this evidence in Kuhrt-1 at §117:

Analogue terminals often included a light that displayed to the user whether the repeater was keyed. If a transmission was sent to a de-keyed analogue repeater, the repeater searched for a CTCSS tone. The CTCSS tone was provided to safeguard the systems against inadvertently keying the repeater on any unintended transmissions. If the repeater detected a valid CTCSS tone, it re-keyed, such that the repeater is able to then repeat received transmissions.

51    The meaning of this is not entirely clear to me. In particular, I am not clear on who provided the CTCSS tone in the third sentence. Overall, the most likely reading of this paragraph is that when it re-keyed the repeater would, before selecting a frequency upon which to broadcast, check to see that that frequency did not already have a CTCSS tone on it. If it did have such a tone, the repeater would re-key to a different frequency.

Digital Two-Way Radios

52    Digital two-way radios were introduced in around the 1990s. In digital two-way radios, voice (and data) is transmitted using binary digits (i.e. 1’s and 0’s) (‘bits’) over RFs. The use of the binary system allows for ‘error correction embedded signalling’ and ‘control information’ to be included in each transmitted packet. I explain these concepts below at [57]. Each packet contains an assembly of bits. For present purposes, digital radios also introduced two other relevant innovations. First, the software in a digital radio contains an algorithm which understands the difference between voice audio and background noise. As a result, unwanted background noise is not transmitted to the radio’s speaker and digital radios provide users with enhanced voice capacity and higher-quality coverage.

53    Secondly, digital two-way radio technologies introduced the ability to divide single-call RF channels. By ‘single-call RF channels’ I mean that the frequency is devoted to the carrying of a single communication. In a digital radio communication, the fact that the transmission is made up of packets of data means that with appropriate timing protocols in place, more than one communication can be carried at one time on the same frequency. This means that multiple users could access a single channel at one time (discussed below at [75]). The first digital two-way radio systems were the:

(a)    MPT1327 (analogue voice with digital control messaging, discussed below at [93]);

(b)    APCO P25 (digital voice and data, discussed below at [100]); and

(c)    Terrestrial Trunked Radio (‘TETRA’) (digital voice and data, described below at [107]).

54    A transmission from a radio user in a digital system comprises two key elements:

(a)    the payload; and

(b)    embedded signalling information (also known as ‘control information’).

55    Mr Kuhrt described transmissions in digital radio systems as having three elements and in a summary section distinguished embedded signalling information from control information. However, his subsequent discussion treated control information as embedded signalling information: see Kuhrt-1 at §§120, 122-123. For present purposes, I will assume that his substantive discussion reflects the correct view.

Payload

56    As I have explained above, payload is the term used to describe the part of a transmission that contains the substantive communication (as opposed to, for example, the control information). It is a type of data that is transmitted in large blocks made up of many bits and usually relates to voice based or data based transmissions. When voice is being transmitted it is typically referred to as ‘voice payload’. Similarly, when data is being transmitted it is referred to as ‘data payload’.

Embedded Signalling (Control Information)

57    After a process referred to as synchronisation (described below at [59]), the receiving station needs to determine what sort of transmission is in progress. This is performed using ‘embedded signalling’ which is also known as control information. Control information is decoded messages which consist of bits or words (which are groups of bits). These messages give information about certain parts of the transmission. For example, the control message could give information about the payload type by differentiating between voice or data, the source of the transmission (i.e. which radio device the message has come from), or the recipient of the message which could be a single radio, a talkgroup or a ‘colour code’. I return to colour codes later in these reasons but, for present purposes, colour codes may be understood as referring to the geographical area covered by a particular base station.

Data Frames

58    Control information is contained within what are called ‘data frames’. A data frame is the frame in a digital communication system which the bits that are used to carry voice and data are packaged into. A frame is a unit of repeating structure and typically includes a specific number of bits. Bits relating to specific functions (e.g. the payload, frame synchronisation, and control messages) are assigned a specific location within a frame. A set frame structure is important as the receiving device needs to be able to decode the bits within a frame. For example, the receiving device needs to know which series of bits provide the payload portion of the received frame.

Frame Synchronisation

59    In order for these data frames to be transmitted, the sending and receiving stations must be in synchronisation. Synchronisation is important for what are referred to as ‘multiple access communications systems’. The current litigation is concerned with such systems. These are discussed below in more detail at [75]. Synchronisation is important in multiple access communications systems because the receiving device needs to determine which portion of the data on an RF is intended for that receiving device. When in use, a receiving device receives a constant stream of bits during the digital transmission. Frame synchronisation enables a receiving device to differentiate between the different portions of the constant stream of data so that it can determine the portion of the data that corresponds to the payload. As I understood this evidence, it means that in a data frame, if different groups of bits are assigned for different purposes, the receiving device must be able to know which part of the stream it is looking at. If a data frame is 216 bits in length, for example, and the first bit of the frame signals some particular meaning (such as whether the channel is active), then this meaning will be lost if the receiving device does not know where the frame starts.

60    To enable frame synchronisation, digital terminal and repeater devices include a crystal. The crystal is an electronic element made from quartz crystal which is used to generate an internal timing reference (like an internal clock). The purpose of frame synchronisation is to synchronise the internal clock of the receiving device (such as a terminal) with the internal clock of the transmitting device (such as a repeater). The purpose of this clock synchronisation is so that the receiving device is then able to recognise the start and end of the data frames. Once the receiving device knows this, it can locate specific portions of the incoming data within each frame.

61    To synchronise with a transmitting device, a receiving device locates what is known as a ‘synchronisation pattern’ or ‘synchronisation word’. A synchronisation pattern or synchronisation word is a known data sequence that is transmitted at certain times or ‘intervals’ during a transmission. This synchronisation pattern is a series of bits that form a word and is a specific sequence of 1’s and 0’s that the receiving device will recognise. I would say by way of further explanation that the two devices do not need to be have been synchronised in order for the synchronisation pattern to be recognised. That is, the synchronisation pattern can be transmitted asynchronously. A useful non-technical analogy might be to think of a train made up of carriages (data frames). The synchronisation pattern corresponds to a fixed symbol in the middle of each carriage (such as a corporate logo). Since it is known how far apart the logos on each carriage are from each other, it is easy to set one’s clock to the same speed as the train just by timing how long passes between each logo. Once that is known, one can access the carriages of the train in sync with its speed and access defined portions of the carriages using one’s own clock. For example, the first 1 m of each carriage might contain information about where the carriage is going.

62    More technically, recognition of the synchronisation pattern allows for frame synchronisation between a receiving and transmitting device. Typically, the synchronisation pattern is located at the start or the middle of the data frame. Once a device locates the recurring synchronisation pattern (recurring because it is located in each repeating frame), the receiving device is able to determine where the pattern is in the data stream and is then able to decode the incoming frames to obtain relevant information.

Frame Synchronisation in Repeater Mode

63    Terminals operating in repeater mode (i.e. where they are communicating through a repeater) synchronise to the reference timing set by the repeater. The repeater sets the reference timing (meaning the timing of the repeating frames) and, as such, the timing of the synchronisation patterns. This ensures that all of the terminals that are connected to the repeater are working to the timing reference and are synchronised to the repeater without conflicting with one another. This is important where multiple channels are included on the one frequency (a topic discussed below). Communications which are received out of synchronisation are ignored by a repeater unless the signal is a ‘wake-up’ message (which I discuss below at [72]).

64    Terminals can lose synchronisation for a variety of reasons. A loss of signal is generally referred to as a signal drop-out or a loss of carrier. Drop-outs can be short (such as a few milliseconds) or long (such as several seconds). Longer drop-outs may occur when the terminal moves too far away from the repeater or during periods of interference (such as when a terminal moves underground or under a bridge and is unable to maintain a signal with the repeater).

65    A phenomenon referred to as ‘Rayleigh fading’ causes short term drop outs in two-way radio systems. Fading may occur due to radio waves reflecting off buildings or other objects which cause an interference to radio signals. In this circumstance, the RF carrier (i.e. signal strength) may drop down to zero and then return very quickly (e.g. within milliseconds).

66    In digital two-way radio systems, terminals communicating in repeater mode may temporarily maintain data synchronisation (or reference timing) during short periods of interference. This is typically a short period of time, however, as the reference timing being maintained by the terminal will begin to drift from the timing which was being provided by the repeater before the interference occurred. The period of time that a terminal is able to maintain frame synchronisation for when there is an interference is dependent on a range of factors including the quality of the terminal’s hardware such as the crystal. For example, the period of time for which a terminal is able to maintain adequate frame synchronisation may be less than one second. When the period of interference ends and the terminal again receives data from the repeater’s downlink (including the synchronisation pattern), it will adjust its timing, if required, to ensure that synchronisation with the repeater remains in place.

67    The eventual drift between a terminal’s reference timing and the repeater’s timing means that after a period of time without receiving transmissions from the repeater, the terminal may then need to resynchronise with the repeater once again to receive and transmit data.

Examples of Systems Using Frame Synchronisation

68    An example of a two-way radio system that includes frame synchronisation is a system called APCO P25 (discussed below). In P25 systems, a special sequence of 48 bits (a synchronisation pattern) is located at the beginning of a frame. In a P25 system, frame synchronisation occurs at the beginning of every message and is inserted every 180 msec throughout the voice message. MPT1327 devices (discussed below) also rely on frame synchronisation in order to decode messages. In TETRA systems (discussed below), the repeater sends out frames in a repeating structure at constant intervals. The receiving device recognises the synchronisation pattern is being received at every interval and will set its own clock to match the intervals of the synchronisation pattern. The terminal can then decode the incoming data frames to obtain relevant information such as the control information or payload. Also inbuilt into the system is a feature that is called ‘forward error correction’ which is designed to compensate for a small percentage of lost data stream (which can occur if the user goes out of range).

Scanning in Digital Two-Way Radio Systems

69    P25 terminals (discussed below) are able automatically to scan frequencies in a conventional two-way radio system. Transmissions between repeaters and terminals include embedded control messaging that allows for the late entry into conversations (such as talkgroup conversations) by scanning terminals.

70    TETRA terminals also automatically scan. However, TETRA terminals scan control channels rather than traffic channels. This occurs periodically to determine if a control channel with an improved signal strength can be identified. Prior to 26 July 2004 (one of the priority dates), the length of time it took automatically to scan frequencies in analogue systems was a well-known problem. Prior to that date, the known digital two-way radio systems provided little improvement on the length of time it took automatically to scan frequencies.

De-keying and Re-keying in Digital Two-Way Radios

71    Similar to analogue repeaters, digital receivers have a hangtimer which prevents the repeater from de-keying immediately after a transmission. This ensures that the receiving user has sufficient time to respond to a communication before the repeater de-keys.

72    In conventional digital two-way radio systems, repeaters require a ‘wake-up’ message in order to re-key. The repeater’s uplink continues to monitor the frequency so the repeater is able to receive transmissions from terminals. This allows terminals to transmit a wake-up message to the repeater, enabling it to re-key. Although the specific type of wake-up message differs between two-way radio systems, every digital system will look for a valid transmission in order successfully to re-key.

73    As previously discussed, terminals are able temporarily to maintain data synchronisation or reference timing during short periods of interference. A short period of interference has the same effect as a condition where a repeater initially de-keys. In both circumstances, the terminal will no longer receive any data from the repeater’s downlink. As such, in both circumstances, the terminal will temporarily maintain data synchronisation without requiring data (such as the repeating synchronisation pattern) to be received from the repeater’s downlink.

74    An issue which exists in conventional digital two-way radio systems is that communications could be lost when a repeater’s downlink is initially deactivated. This can occur because of the inability of a receiving terminal to maintain reference timing in a temporary data synchronisation state. When this occurs, it is possible that the terminal transmitting a communication may not recognise that the repeater has de-keyed. This presents an issue because the terminal may continue to transmit communications which are then not repeated to the intended receiver.

Multiple Access Methods

75    There are three well-known and generally accepted methods implemented to utilise the limited RF spectrum more efficiently in two-way radio wireless communications. These methods aim to increase the number of users communicating within a specific portion of the radio spectrum. They are:

(a)    frequency division multiple access (‘FDMA’);

(b)    time division multiple access (‘TDMA’); and

(c)    code division multiple access (‘CDMA’).

76    CDMA was not used for two-way radio systems before 2004 and was instead used in cellular telecommunications systems.

1.    Frequency Division Multiple Access (FDMA)

77    FDMA separates RF channels by frequency. For instance, for two-way radio communications, FDMA may split a 12.5 kHz channel into two, smaller, 6.25 kHz channels which communications can each be transmitted on. FDMA was introduced into digital two-way radio systems in the 1990s. It has been implemented into both digital and analogue two-way radio systems such as the P25 digital radio system. An illustration of FDMA channel splitting is this:

78    Using FDMA, a conversation occupies a whole channel exclusively, meaning there is one user and one conversation at a time per channel. To increase the number of channels it is necessary to increase the number of frequencies. However, it can be difficult and costly to obtain channel assignments from the regulator. For example, using FDMA, four users (each of whom wishes to communicate at the same time) would need access to four 6.25 kHz channels (which would be split from the two 12.5 kHz channels).

2.    Time Division Multiple Access (TDMA)

79    TDMA was introduced in or around 1979 as a common multiple access technique for wired networks. It was first introduced to digital two-way radio systems in the 1990s and is still currently implemented into digital two-way systems. TETRA was the first system to implement TDMA in two-way radios.

80    TDMA separates RF channels into different timeslots while preserving the width of the 12.5 kHz channel. Timeslots are a defined period of time (usually a very short period of time) during which the sender’s communication is transmitted. TDMA allows several users to share the same channel. As a user transmits, their communication will be inserted into a timeslot of a very short, fixed period (such as 50 msec or one twentieth of a second). Usually, a mobile station operating in repeater mode will be allocated to a timeslot by a repeater whereas a mobile station operating in direct mode is able to transmit in a free timeslot which is available on the frequency.

81    Users transmit in rapid succession which gives each user the impression that they have exclusive use of the channel and that their communication is being broadcast in real time. For example, in a two-timeslot TDMA system, two users can share one frequency at the same time. The distinction between FDMA and TDMA systems can thus be illustrated in the following way:

82    In a TDMA system, User 1 utilises the frequency for the first timeslot (slot 1 in the above diagram) then User 2 transmits for the next fixed period of time (slot 2). The channel then reverts back to User 1 who transmits for the next fixed period of time. The channel then reverts back to User 2 who transmits for the next time period and so on. The process occurs so quickly that neither user is aware that they are sharing a channel and neither experiences a delay in transmission. However, if more than two users wish to transmit, additional radio channels are needed. For example, in a two-timeslot TDMA system, four users who wished to communicate at the same time would require two 12.5 kHz frequencies.

83    TDMA introduced the ability to divide the physical channels (e.g. the 12 kHz channel) into logical channels. A logical channel is a channel which has the appearance and functionality of a channel but which is, at a technical level, actually made up of quite different constituent elements. So for example, a user could select a logical channel designated as channel 1. This logical channel consists of one slot on the transmit frequency and a corresponding slot on the receiving frequency. Although the communication is happening over two frequencies, those two frequencies constitute, so far as the user is concerned, a channel called ‘1’.

84    A half-duplex radio device cannot transmit and receive at the same time. However, using TDMA, such a device can constantly tune between the transmit and receive frequencies which has the effect of simultaneous transmitting and receiving for the user. This is possible for mobile stations operating in either repeater mode or direct mode.

Conventional Two-Way Radio Systems

85    At a high level, there are two categories of two-way radio systems: conventional and trunked systems. A ‘conventional system’ uses a dedicated repeater and a fixed number of RF channels. The user may manually select which channel they want to listen to. If a channel is in use, a user must wait for the channel to be free before being able to utilise that channel. Such a system may be illustrated this way:

86    In this set up, users select a channel on which to transmit. However, only one user can transmit on each channel at one time. So, the second and third users on Channel 1 (represented pictorially above in the second and third rectangles) as well as the second user on Channel 3 (the second circle) would be required to wait for the first user to finish transmitting on the frequency before they could use the channel for communications. In contrast, the police user (the sole user of Channel 2) can transmit immediately. Importantly, in a conventional two-way radio system, users cannot make use of the other channels which may be available unless they manually tune to them. In the above example, for instance, the second or third user waiting to transmit on Channel 1 (the ambulance users) could not utilise Channel 2 to transmit once the police user has finished transmitting unless they re-tuned their device to Channel 2.

87    The number of users who can successfully access a conventional system therefore directly corresponds to the number of channels that are available. As a result, conventional radios often have dedicated channels for specific users or groups of users. If an agency such as a police station wishes to add an extra channel or talk path they are required to seek a channel assignment from the regulator.

Trunked Systems

88    Trunking is not directly relevant to this case. However, one of the patents involves a concept known as ‘pseudo-trunking’. In order to understand what pseudo-trunking is, it is necessary to understand trunking.

89    A different category of two-way radio system is known as a trunked system, which was developed in around the 1980s. Unlike conventional two-way systems, trunked systems do not require users manually to select the channel upon which they wish to transmit. Instead, trunked systems automatically allocate users to an available channel (that is, one which is not in use) and release the channel once the user has finished transmitting (thus allowing other users to be automatically allocated to it). As a result, trunked systems increase the number of users who can use the system by more efficiently allocating the frequency resources which are available.

90    In the above example involving Channels 1-3, for instance, in a trunked system the second or third user waiting to transmit on Channel 1 would be able to utilise Channel 2 to transmit once the police user had finished transmitting without needing manually to change channels. This decreases the likelihood of the user having to wait for an available channel, increasing the number of users that can transmit using the radio system in a period of time.

91    To do this, trunked systems work by having users transmit to what is called a ‘control channel’. The control channel then allocates users to what are called ‘traffic channels’ on which they can communicate. Traffic channels can be shared between groups of radio users (or ‘talkgroups’ as explained above). An illustration of a trunked system is thus:

92    In Figure 8, the ambulance user could be allocated to Channel 1, both fire users could be allocated to Channel 2 and the police user to Channel 3. This means that members of the same talkgroup can share a traffic channel (and so share a frequency). Often, if one member of the talkgroup is transmitting a message (e.g. the first fire user), the other users (the second fire user) will be listening. This means the other users in the same talkgroup will not be using the channel to transmit at the same time.

WELL-KNOWN DIGITAL RADIO SYSTEMS BEFORE JULY 2004

The MPT1327 Standard

93    One of the first trunked two-way radio systems was the MPT1327 Standard. This is a standard which was developed by the United Kingdom Ministry of Posts and Telecommunications in the mid-1980s. It is a hybrid digital/analogue radio communication system in that it transmits both data (to set up a call) and analogue voice communications. It includes a trunked system controller that retains information including a list of terminal devices that are subscribed to the network, a record of the location of the terminals subscribed to the network, and the configuration of repeaters connected to the network. Each repeater in the network is connected to the traffic system controller with several cables, including a data cable for the dedicated control channel and physical cables for each of the repeaters that have traffic channels. MPT1327 systems include ‘sites’ that each typically include several connected repeaters. One of the repeaters in each site operates as the dedicated control channel and the remaining repeaters are associated with the traffic channels.

94    Terminals connected to an MPT1327 network communicate with the dedicated control channel in order to set up and receive calls. Unless the system includes a time shared control channel, system users are typically allocated a traffic channel on the site that they are connected to in order to communicate with another system user. In a time shared MPT1327 system, the control channel can also be allocated as a traffic channel.

Scanning in MPT1327

95    Terminals in an MPT1327 system automatically scan the control channels associated with repeaters in the network on a regular basis to determine if a site with increased signal strength is able to be located. To enable the automated scanning process, the terminals include a list of frequencies associated with control channels as well as associated repeater identifications in the network that are saved to memory in the terminal.

96    MPT1327 terminals typically included more frequencies saved to the memory to which the terminal is subscribed. For example, in the 2000s, Victoria was split into geographical regions such as city and country regions. In order to use multiple regions, the terminal needed to be a subscriber to repeaters associated with sites located in the multiple regions. If the terminal was not a subscriber to a repeater in a particular region, the trunked system controller would not allow the terminal to lock onto a control channel, even if the control channel was stored to memory within the scanning terminal.

97    The repeater associated with the control channel for each site transmits control messages on the control channel to perform an action, such as setting up calls. The control messages included information such as the identification of a source terminal, the identification of a talkgroup, the identification of a site and the identification of a repeater (i.e. the traffic channel). Examples of control messages which are used by MPT1327 systems include:

(1)    A Go To Channel Message (‘GTCM’): The GTCM is transmitted by a repeater on the control channel to connected terminals to set up calls. It can be used to allocate a terminal to a particular talk channel, which can also be the control channel for systems that utilise a time shared channel (e.g. a channel that, at different times, is used as a control channel and a talk channel). The GTCM is referred to in Section 5.4 of the MPT1327 Standard. The GTCM includes the following information:

(a)    Destination identification or group identification;

(b)    Source identification; and

(c)    Channel information.

(2)    A Vote Now Message (‘VNM’): On occasion, a repeater uses a version of the broadcast message to transmit a control message on the associated control channel to the terminals connected to the site associated with that repeater to instruct the connected terminals to scan for a frequency with a higher signal strength; and

(3)    A Short Data Message (‘SDM’): SDMs have a specified size but could be used by service providers to transmit any form of data. For example, the SDM was used to send GPS location reporting messages as this information could be transmitted using the specified data size. SDMs were transmitted on the control channel. In order to allocate specific data to an SDM, users needed to make a request to the trunked system controller.

98    MPT1327 used fast frequency shift keying (‘FFSK’) to transmit data over the control channel. FFSK implements a technique that allows for digital data to be transmitted using an analogue signal. An electromagnetic carrier wave is used to carry the digital data over a distance and connect repeaters with terminals in remote locations. In FFSK, the repeaters transmit data on the control channel by modulating the carrier frequency between two discrete values. Each of the discrete values correspond to a zero and a one (the components of digital data). The terminals are able to receive and decode the digital data corresponding to control messages then perform the desired functions.

De-keying in MPT1327

99    MPT1327 terminals are not able to communicate with each other in direct mode but use repeaters to transmit. Similar to conventional analogue two-way radio systems, the repeaters in trunking two-way radio systems (such as MPT1327) de-key when the downlink associated with the repeater is not in use (e.g. when the traffic channel is released). At the end of a transmission, terminals leave the traffic channel that was being used for a communication. A message is then sent to the traffic system controller, indicating that the conversation is complete. After certain conditions are met, such as after the expiration of a timer, the traffic system controller sends a message to the repeater associated with the traffic channel that is no longer in use and instructs the repeater to de-key. It is not clear to me how an MPT1327 repeater in such a configuration re-keys.

APCO P25

100    APCO P25 is a set of digital two-way radio standards that were produced by the Association of Public Safety Communications International (‘APCO’) in the United States (‘US’) in the 1990s. P25 is an open architecture that defines a digital radio communications system for public safety organisations. P25 was implemented by manufacturers and organisations such as Motorola, Tait, Harris/MA-COM and Simoco.

101    The P25 standards define the interfaces, operation and capabilities of P25 radio systems. Before 26 July 2004, P25 systems were both conventional and trunked digital two-way radio communication systems that transmitted data using FDMA methods. These systems are now referred to as ‘Phase 1 P25’. Phase 1 systems operate using a 12.5 kHz frequency bandwidth and use Continuous 4 Level FM (‘C4FM’), a type of frequency shift keying (‘FSK’) modulation to transmit data. P25 systems implement a vocoder to encode speech (tone and audio level) into a digital data stream.

102    P25 transmissions include a link control (‘LC’) message that forms part of voice transmissions to provide signalling information to terminals. The LC message is referred to as an LC word in section 5.5 of the P25 FDMA Common Air Interface. Examples of LC words are shown in the P25 standards and include:

(a)    A message to specify the Link Control Word’s content (LCF);

(b)    The manufacturer’s identification (MFID);

(c)    Talkgroup identification (TGID);

(d)    Source identification (Source ID);

(e)    Destination identification (Destination ID); and

(f)    An emergency indicator.

Scanning in P25

103    P25 terminals are able automatically to scan frequencies that are saved to memory in the terminals. P25 transmissions between repeaters and terminals included embedded control messaging that allowed for the late entry into conversations (such as a talkgroup conversation) by scanning terminals. For example, a sequence of bits provides frame synchronisation which allows for the messages which follow to be decoded. For P25 transmissions, frame synchronisation messages are located at the start of every voice and data transmission and within transmissions (spaced at 180 msec intervals as provided for in the P25 standards) to allow for late entry by terminals. Once a terminal has synchronised to a transmission, it is then able to determine if the transmission is relevant by interrogating the LC message, that is to say, the LC word. This might occur to determine if an LC message indicates that the transmission is for a talkgroup to which the scanning terminal is subscribed.

104    The LC word is included in the Logical Link Data Units (LDU1 and LDU2) that are transmitted during a voice call. In order to receive LDU1 and LDU2 while scanning, a P25 terminal needs to decode all of the data being transmitted, including the data associated with the error correction algorithm. This was a known limitation with P25 systems and meant that it was slow to lock onto a channel.

105    An additional associated limitation with P25 systems was that a P25 terminal required several messages within a data stream to be decoded and then interrogated for the required information (such as a talkgroup identification number or an emergency status bit). Thus, automatically scanning for incoming transmissions in a P25 system was a slow process as terminals were required to decode large parts of the data stream and perform error correction of the data to allow the terminal then to interrogate the data stream for conditional requirements before locking onto a particular channel. If the transmission was a voice call, most of the packets of data were allocated to the payload being transmitted and the address information would only be transmitted every ninth frame (being every 180 msec). This meant that terminals needed to wait until the relevant information (e.g. the emergency status bit or the talkgroup ID) was received and decoded before the terminal was able to make a decision with respect to remaining on a channel. As a result, P25 did not provide much improvement to the well-known scanning problem with reference to analogue systems. This was a well-known limitation of P25.

De-keying and Re-keying in P25

106    P25 two-way radio systems can be used in conventional direct mode and repeater mode. Terminal devices also may include a button that allowed for users to toggle between the different modes. Similar to conventional analogue two-way radio systems, the repeaters in P25 systems keyed and de-keyed when the downlink associated with the repeater was not in use (such as when the talk channel is released). Also, similar to conventional analogue two-way radio systems, the repeaters in P25 systems on occasion included a timer to prevent the repeater from de-keying immediately after a transmission.

TETRA

107    TETRA is a digital trunking system that was standardised by ETSI in the mid-1990s. It was first introduced commercially in the early 2000s. TETRA is a digital system that implements TDMA to transmit communications between terminals and repeaters. Each TDMA frequency of 25 kHz is separated into four timeslots to allow for several communications to take place on a single frequency.

108    TETRA systems implement a vocoder to encode speech into a digital data stream. TETRA terminals are able to communicate directly with one another, without using a repeater. This is referred to as direct mode operation. Devices which implement TETRA perform frame synchronisation to transmit communications.

109    TETRA is similar to MPT1327 in that it includes a dedicated control channel. However, unlike MPT1327, because the system implements TDMA, a single repeater can be used for both a control slot and multiple talk slots. This means one timeslot can be used to communicate control messaging and the remaining timeslots can be used to communicate voice and data between terminals. TETRA implements a form of phase-shift keying (differential quadrature phase-shift keying (‘4DQPSK’)) to transmit data between connected repeaters and terminals. Phase-shift keying is a method of conveying data by modulating the frequency. It is not necessary for the purposes of these reasons to explore the nature of phase-shift keying. However, similar to MPT1327, the repeater associated with the control channel for each site transmits on the control slot to perform actions such as setting up calls. As also occurs in MPT1327, the control messages include information such as the identification of a source terminal, the identification of a talkgroup, the identification of a site, and the identification of a repeater.

Scanning in TETRA

110    Scanning in TETRA occurs on control channels, rather than on traffic channels. The scanning issues which existed in other systems, such as P25, still exist in TETRA. However, the use of control channels means it is not as noticeable to the user as the delays occur in the background. As a trunked system, in TETRA, the network is responsible for orchestrating scanning. As a user communicates on one channel, the network operates behind the scenes continually to scan for an alternative, improved channel. The issue of timing thus still applies to TETRA trunked systems but is far less relevant to users.

Colour Coding in TETRA

111    Colour coding was first introduced in TETRA two-way radio systems. Colour coding is a system in digital mobile radios which allows for the separation of groups of users (such as different service providers or systems) who are sharing the same frequency or channel. Colour coding prevents radios from one group from mistakenly crossing into another group which uses the same frequencies and so stops interference within a channel.

112    The purpose of colour codes is to differentiate multiple receivers that are within a geographical area using the same frequency. Colour coding is assigned by the system administrator and differentiates each group by their colour code. Each colour code is represented by a number (e.g. red equals one). Colour coding information is contained within control messages.

113    Mobile stations can be programmed with multiple colour codes (one for each channel) but a repeater can only be programmed with one colour code. In order for a mobile station to access a certain repeater, it must be programmed with the colour code assigned to that specific repeater. For example, if there are two repeaters with overlapping coverage areas, and both are trying to use the same frequency, Repeater 1 will be assigned the colour red and Repeater 2 will be assigned the colour blue. If there was a third repeater, but it was far enough away from Repeater 1, then Repeater 3 could also be assigned the colour red and utilise the same frequency. If a mobile station wishes to utilise Repeater 2 for transmission, it will need to be programmed with the colour blue. This is illustrated in Figure 10:

The Draft DMR Protocol

114    There is a document entitled ‘Draft Agenda Narrowband TDMA DMR Protocol’ which all parties referred to as the ‘Draft DMR Protocol’: Kuhrt-1 at §291. It is dated 26 April 2004. It describes a digital two-way radio system that implements TDMA methods. It is the precursor to the 2005 DMR Standard. The Draft DMR Protocol was discussed during a working group meeting at ETSI during the development of the DMR standards. Both Mr Kuhrt and Professor Rangan agreed that if a person had been tasked with designing a method for scanning in a digital two-way radio system in July 2004, that person would have located a copy of the Draft DMR Protocol in order to understand what had already been done in this area.

WELL-KNOWN DIGITAL RADIO SYSTEMS BEFORE 28 JULY 2005

115    In the field, each of the above two-way radio systems (i.e. MPT1327, P25 and TETRA) were part of the CGK prior to 28 July 2005 (the priority date of the 960 Patent). In addition to those, by 28 July 2005 the ETSI DMR standards were well-known by those working in the field of two-way radio communications.

DMR Standards

116    DMR is a digital two-way radio system that was standardised by ETSI in April 2005. It was originally developed to be a secure digital equivalent to traditional analogue transmissions and the conventional P25 two-way digital radio system. The purpose of the ETSI DMR standards was to standardise digital radios worldwide, to reduce channel interference, and to increase radio spectrum efficiency. Systems which operate using the ETSI DMR standards implement a vocoder to encode speech into a digital data stream.

117    The first ETSI DMR standard evolved from an earlier Digital Interchange of Information and Signalling (‘DIIS’) specification for a two-way radio system. DIIS, which ETSI also attempted to standardise, was developed in the early 2000s. However, DIIS was not embraced by the two-way radio community. Many of the principles from DIIS were then incorporated into the DMR standards.

118    DMR standard compliant systems operate using two-slot TDMA to transmit communications. That is, each TDMA frequency is separated into two timeslots to allow two communications to take place on a single frequency. DMR compliant systems can operate in either simplex or duplex mode meaning that mobile stations operate on either one or two frequencies. Duplex DMR compliant systems have one frequency for transmitting and a separate frequency for receiving (known as a frequency pair or physical channel). Thus use of TDMA in DMR compliant standards means that physical channels could be divided into logical channels.

119    Similar to previous digital and analogue two-way radio systems, the DMR standards allowed for direct mode communications between terminals. The purpose of this was to allow for systems that required less infrastructure because no repeater is required for direct mode communications, or for when a repeater is unavailable.

WELL-KNOWN DIGITAL RADIO SYSTEMS BEFORE 3 OCTOBER 2008

120    Each of TETRA, P25, MPT1327and the DMR standards were part of the CGK by 3 October 2008 (the priority date of the 764 Patent). Mr Kuhrt gave evidence that he became aware in 2008, whilst working on a DMR compliant device, of a problem with two-way radios which implemented the DMR standards. This problem related to the operation of such devices in direct mode and reflected the fact that in direct mode it was not possible for both timeslots to be used at the same time by two separate users.

INTERNATIONAL FIELD

121    Mr Kuhrt thought, and I accept, that in Australia by both July 2004 and July 2005 persons working in the field of two-way radio communications would have been familiar with the systems described above. He thought that this might not have been so in the US and Europe. He inclined to the view that those working in Europe would have been more familiar with the standards applying in Europe (MPT1327 and TETRA) whilst those in the US would have been more familiar with APCO P25. He thought that persons practising in the field in Australia would have been familiar with the standards in both Europe and the US since Australia was something of a green fields market (i.e. there was no local standard). I accept this evidence.

122    Having set out this general background it is now useful to turn to the three patents in suit.

III    THE PATENT TRIAL

123    Motorola is the patentee of three Australian standard patents:

124    Motorola alleges that from at least September 2013, Hytera and Hytera Australia have distributed in Australia by various means a range of DMR devices to the public without its licence. In the case of a subset of the Hytera devices Motorola claims that Hytera has infringed claims 1 to 6 and 10 of the 355 Patent. In relation to another subset of the Hytera devices Motorola claims that Hytera has infringed claims 1 to 5, 8 to 15, 17 and 18 of the 960 Patent. Finally, in relation to another subset of the Hytera devices Motorola claims that Hytera has infringed claims 2 and 3 of the 764 Patent. In relation to the Hytera devices, Hytera has since the commencement of these proceedings reprogrammed each of its DMR devices in an attempt to ensure that they do not infringe the three patents. Motorola says that this reprogramming effort has not achieved that outcome. There is also therefore a separate set of issues in relation to each patent about the status of the reprogrammed devices.

IV    THE 355 PATENT

INTRODUCTION

125    The issues which arise in relation to the 355 Patent are:

(a)    the proper construction of claims 1 and 5;

(b)    whether the 355 Patent is invalid for want of an inventive step;

(c)    whether the 355 Patent is invalid for want of utility;

(d)    whether Hytera is liable for secondary infringement where an unreprogrammed base station is used with an unreprogrammed subscriber unit;

(e)    whether Hytera is liable for secondary infringement where a reprogrammed base station is used with an unreprogrammed subscriber unit;

(f)    if yes to (e), whether Hytera is entitled to rely upon a defence of standards essentiality; and

(g)    what the scope of injunctive relief should be.

The Evidence

126    Motorola’s evidence both as to validity and infringement of the 355 Patent was given by Professor Rangan. Hytera’s evidence about the 355 Patent was given by Professor Viterbo (as to infringement), Mr Kuhrt (as to validity) and Mr Grimmett (as to standards essentiality).

Professor Rangan

127    Professor Rangan is a Professor of Electrical and Computer Engineering at New York University. Over the past twenty years he has been engaged in industry research and development at Qualcomm, Microsoft, Bell Laboratories and others. He was appointed Associate Professor at New York University in 2010 and Professor in 2018. He also has substantial experience in technology standardisation and source code writing and review.

Professor Viterbo

128    Professor Viterbo is a Professor of Electrical Engineering and the Associate Dean of Graduate Research for the Faculty of Engineering at Monash University. He completed a PhD at Politecnico di Torino between 1992 and 1995, producing a thesis relating to coding for wireless telecommunications. Since about 1990, Professor Viterbo has worked for various organisations including the European Patent Office, Politecnico di Torino, Telecom Italia Labs, AT&T Labs, the University of Calabria and Monash University. He has considerable source code experience and can program in and understand the programming languages of C, C++ and Matlab. He has also been involved in projects relating to the development of technical standards.

Mr Kuhrt

129    Mr Kuhrt is an electronic engineer. He completed a Bachelor’s degree in Engineering (Electronics) at Swinburne University of Technology in 1984. Since that time, Mr Kuhrt has worked in various positions for Hewlett Packard, Philips Communications, Simoco Pacific, TMC Radio, Simoco Group and, most recently, Pacific Wireless Communications. Throughout his career, Mr Kuhrt has acquired substantial experience in designing and implementing two-way radio telecommunications systems. He has specialist knowledge of relevant telecommunications standards and the hardware, software and production requirements for two-way radio systems.

Mr Grimmett

130    Mr Grimmett is a Technical Director. He completed a Bachelor of Science in Computer Science at Coventry University in 1992. Since leaving university, Mr Grimmett has worked in various roles, including as a software engineer, for four company groups: Mobicom (which became Simoco), Alstom Automation, Simoco, Experian and Pyronix. He has 20 years of experience working in the field of private mobile radio communications and possesses expertise in the design, development and deployment of analogue and digital radio technologies. As a member of the Digital Mobile Radio Association since 2010, Mr Grimmett has been involved in developing proposals for the improvement and development of the ETSI DMR standards (telecommunications standards of relevance to this proceeding which will be discussed in due course).

Description of the Patent

131    The 355 Patent is entitled ‘Method and system of scanning a TDMA channel’. It has a priority date of 26 July 2004. The patent describes the field of the invention as relating generally to ‘wireless communications systems and more specifically to scanning in a time division multiple access (TDMA) system’. The patent describes the background of the invention in these terms:

A wireless communications system may generally comprise a set of “subscriber units,” typically subscriber units are the endpoints of a communication path, and a set of “base radios,” (also known as “repeaters”) typically stationary and the intermediaries by which a communication path to a subscriber unit (SU) may be established or maintained. One such type of system is a time division multiple access (TDMA) communication system where the radio medium (or RF frequency) is divided into time slots to carry the communications of the system. Because the communication system carries many communications at one time, a subscriber unit may want to monitor other communications in the system. Scan is a feature that allows a subscriber unit to monitor other communications in the system.

SUs of the wireless communications system utilize a feature termed “scan” where an SU locks on to specific RF frequencies in a preprogrammed list in the SU. The RF frequencies in the scan list may be associated with more than one wireless communications system. For example, an SU may have RF frequencies from the Schaumburg fire department and the Rolling Meadows fire department in its scan list. If the preprogrammed scan list is very long and has many RF frequencies, then the scan feature takes a long time. Further, in the usual case, when many of the RF communications are normally of no interest to the scanning SU, the scanning SU spends a lot of time listening to communications that are of no interest to it. For example, this occurs when an RF frequency is included in the preprogrammed scan list, but the current communication is addressed to a SU or group of SUs that are of no interest to the scanning SU.

Accordingly, there exists a need for scanning a TDMA channel which improves the amount of time that an SU spends scanning.

132    A summary of the invention is then given in these terms:

According to one aspect of the present invention there is provided a method for scanning a TDMA channel by a subscriber unit in a wireless communications landscape, wherein the subscriber unit is operationally connected to at least one base radio over a plurality of channels, the method including the steps of:

locking onto a channel of the plurality of channels by the subscriber unit wherein a subset of the plurality of channels is preprogrammed in a list in the subscriber unit;

transmitting from at least one base radio a control message to the subscriber unit wherein the control message has a first information which informs the subscriber unit of activity present on the channel of the plurality of channels;

receiving and decoding the control message for the first information by the subscriber unit; and

if the first information indicates that activity is present on the channel of the plurality of channels, then determining whether the activity is of interest to the subscriber unit by comparing a second information in the control message with a third information preprogrammed in the subscriber unit and

if the activity is of interest to the subscriber unit, then remaining on the channel of the plurality of channels to receive the activity present on the channel.

According to a further aspect of the present invention there is provided in a TDMA system whereby the TDMA system includes a plurality of subscriber units and a plurality of base radios, a method for scanning, the method including the steps of:

locking onto a channel preprogrammed in a list of a subscriber unit whereby the channel carries activity on one timeslot of the TDMA system;

receiving an activity update message from a base radio of the plurality of base radios wherein the activity update message indicates in a first information the activity on the channel and indicates in a second information at least one characteristic of the activity on the channel;

determining whether the activity is of interest to the subscriber unit by comparing the at least one characteristic with preprogrammed third information in the subscriber unit; and

if the activity is of interest, then remaining on the channel to receive the activity; otherwise moving to the next channel in the list.

133    As will be seen, a significant issue which divides the parties is the relationship between the invention disclosed in the claims and the invention which appears in the detailed description of the invention in the body of the specification. Under the heading ‘Brief Description of the Figures’ there appears references to three figures in these terms:

An illustrative embodiment of the invention is now described, by way of example only, with reference to the accompanying figures in which:

FIG. 1 is a block diagram of an example wireless communications landscape in accordance with an embodiment of the invention.

FIG. 2 is a flow diagram of an example method for providing channel access for voice transmissions.

FIG. 3 is an example of a specific Common Announcement Channel message called an Activity Update.

…

134    The three figures are then explained in the remaining body of the specification under the heading ‘Detailed Description’. Figure 1 is as follows:

135    So far as this case is concerned, little controversy attends Figure 1. It is described in these terms at p 2 line 18 to p 3 line 20:

Referring now to FIG. 1, there is shown an example of the method and apparatus of the present invention as it may be employed and incorporated into a typical wireless communications landscape 100 having system 100, system 120, and system 130. The illustrated example has three systems 110, 120, 130 whereby a system is comprised of a multiplicity of communication resources of RF frequencies, base radios (BRs) and subscriber units (SUs) optionally managed by system controllers (not shown) whereby the SUs send and receive communications with BRs (also known as “repeaters”).

System 110 comprises a plurality of cells, each with a BR 3, 5, 7, 9, 11, 13 typically located at the center of the cell, and a plurality of SUs 12, 14, 16, 18, 20, 22 all of which are communicating on RF frequencies assigned to system 110. The SUs 12, 14, 16, 18, 20, 22 in system 110 may include all the RF frequencies associated with the BRs 3, 5, 7, 9, 11, 13 in system 110 in their preprogrammed scan lists. System 120 comprises a plurality of cells, each with a BR 26, 28, 30 typically located at the center of the cell, and a plurality of SUs 34, 36, 38 all of which are communicating on RF frequencies assigned to system 120. The SUs 34, 36, 38 of system 120 may include all the RF frequencies associated with BRs 26, 28, 30 in their preprogrammed scan lists. Further, SU 36 may include RF frequencies associated with the BRs in system 110 and with the BR in system 130 since the SU 36 is sufficiently close to all three systems 110, 120, 130. System 130 comprises a cell with a BR 24 and SUs 32, 40 all of which are communicating on RF frequencies assigned to system 130. Further, BRs 3, 13, 24, 28 may all be operating on the same RF frequency, but using a different color code since the BRs are separated by great geographical distance.

A BR preferably comprises fixed equipment for communicating data/control and voice information to and from the SUs for facilitating communications between the SUs in the wireless communication landscape 100. A subscriber unit (SU) preferably comprises mobile or portable devices (such as an in-car or handheld radios or radio telephones) capable of communicating with a BR using time division multiple access (TDMA) or time division duplex (TDD) techniques as further described herein, in which specified time segments are divided into assigned time slots for individual communication. As is known in the art, each RF frequency in the system carries time slots whereby each time slot is known as a "channel." Thus, for the BRs shown in FIG. 1, each BR has two channels associated with the coverage area.

136    The description then turns to an illustrative embodiment of the invention. The first part of this is at p 3 line 21 to line 29:

In an illustrative embodiment of the present invention, the wireless communications landscape 100 assumes a two slot TDMA communications system; however, other slotting ratios may be used in the TDMA communications system and still remain within the spirit and scope of the present invention. In an illustrative embodiment, the SU determines time slot numbering by decoding a TDMA channel field in a Common Announcement Channel (CACH) burst whereby the CACH burst is used for signalling information in the wireless communications landscape 100. In the illustrative embodiment of a two slot TDMA communications systems, the CACH burst is common to timeslot 1 and to timeslot 2.

137    The priority date for the 355 Patent is 26 July 2004. By this time, the DMR Standard had not yet come into effect and would not come into effect until 2005. That standard prescribed a two timeslot TDMA system. The illustrative embodiment proceeds on the same basis. An important aspect of this paragraph is its reference to the Common Announcement Channel (‘CACH’) burst. The CACH burst is used for signalling information and, in the illustrative embodiment, is common to both channels. Later in the description it becomes important to know this fact – the illustrative embodiment proceeds on the basis that the CACH burst is the same for both channels. An implication of this, borne out later in the description, is that the CACH burst carries signalling information for both channels.

138    The description then continues at p 3 line 30 to p 4 line 9:

As is known in the art, “color code” is a common identifier used by a group of SUs which utilize the same BR. For example, as shown in FIG. 1, SUs 12, 14, 22 are in one color code because they utilize the same BR, namely BR 9. Further, a color code field may be present in an embedded signaling message and a general data burst to provide a means of addressing a radio network or a specific repeater so that cochannel interference may be rejected. Further known in the art, a “talkgroup” is a group of SUs that share an RF frequency and timeslot and have the same color code. In an illustrative embodiment, a talkgroup is identified by a 16-bit talkgroup identifier (TGID and an individual subscriber unit is identified by a 24-bit subscriber unit identifier (SUID). Thus, in an illustrative embodiment, SUs that share a color code are further subdivided into talkgroups so that SUs in one talkgroup do not hear SUs in another talkgroup.

139    This accords with the discussion of colour coding set out above in Chapter II. Important concepts are the ideas of the Talkgroup Identification (‘TGID’) and Subscriber Unit Identification (‘SUID’). It will be noted that in the illustrative embodiment, these are 16 bit and 24 bit fields respectively. As will be seen later in the discussion of the CACH burst, the length of the SUID and TGID are important elements of the debate between the parties.

140    The description then continues at p 4 line 10 to line 21:

As used herein, the terms “communication” and “transmission” are used interchangeably and refer to contiguous TDMA bursts emanating from one radio in one timeslot. As such, transmissions may generically refer to voice, data or control information relating to the wireless communications landscape 100. The term “call” refers to related voice transmissions between SUs in the wireless communications landscape 100.

As is known in the art, the term “burst” refers to the smallest standalone unit of a TDMA transmission. In an illustrative embodiment, for a burst found in a Motorola Low Tier Digital system, a defined transmission is 216 bits of payload and 48 bits of synchronization or embedded signaling. The defined transmission takes 27.5 msec to transmit and may be followed by 2.5 msec of guard time or the CACH burst. Thus, a “burst” in such a Motorola Low Tier Digital system is 30 msec.

141    Again, this is important for some of the disputes between the parties. The defined transmission used in the illustrative embodiment is 264 bits in length. It takes 27.5 msec to transmit. It is followed by a period of 2.5 msec which can be used as guard time or for a CACH burst, it being recalled from the above that the CACH burst is used for signalling information and is transmitted on both slots 1 and 2. The total burst is therefore 30 msec. A little later in the description there is a discussion of a particular kind of CACH message known as an ‘activity update message’ which is transmitted by means of four CACH bursts: page 6 line 24. What this means is that the activity update message is transmitted in the last 2.5 msec in each of four 30 msec bursts. It is not clear from the description at this stage whether these bursts are successive or whether other signalling information is conveyed by means of the CACH bursts. Later in the description, however, it becomes apparent that more signalling information in the form of seven CACH bursts, known as the full LC message, also utilise this 2.5 msec portion. I will return to the activity update message shortly, but it may be noted that, as Professor Rangan confirmed at T806.1-4, in the illustrative embodiment, the activity update message is itself 28 bits in length:

MR BURGESS: Thank you, Professor. And the activity update message described in the body of the 355 patent is 28 bits in size; correct?

PROF RANGAN: I believe that’s correct.

142    It may be surmised from Figure 3 that each of the four CACH bursts occurs as the last 2.5 msec of the burst, that three of the four bursts contain 8 bits, and that one of the bursts contains 4 bits:

143    Very important also is the fact recorded at p 6 line 24 to 27 that the activity update message (transmitted by means of the four CACH bursts) is ‘used to assist in identifying whether there is an active transmission (also termed “activity”) on the channel’. It also ‘provides information that indicates whether the scanning SU should dwell on the channel or should resume scanning’. Jumping ahead a little, determining that there is no active transmission on the channel would be a good reason for resuming scanning. But even if there is activity on the channel, the information contained in the activity update message may indicate to the subscriber unit that the activity is not of interest to it. That observation will in due course feed into the question of the meaning of some of the claims. Part of the controversy between the parties concerns the nature of the information contained in the activity update message. For present purposes it will be seen, however, that the illustrative embodiment proceeds on the basis that the activity update message both indicates whether there is activity on the channel and also provides unspecified (at this stage) information to determine whether to ‘dwell’ on the channel or move to the next channel. The word ‘dwell’ does not appear in the claims and prefigures one of the debates between the parties which concerns whether the decision to dwell is a permanent decision or whether the subscriber unit, once confronted with further information, might decide to stop dwelling on the channel and move on to scanning for the next channel. Hytera’s construction case is that this is not permissible.

144    The description then continues to discuss the nature of scanning at p 4 line 22 to 28:

In an illustrative embodiment, a scan is performed in at least one of three situations: 1) when the SU powers on where the receiver automatically changes "channels" in a set order with a list preprogrammed in the SU, 2) when a user of the SU manually taps a button or turns a dial to manually step through frequencies preprogrammed in the SU, and 3) when a user of the SU sets the SU to scan mode where the receiver automatically changes frequencies in a set order with a list preprogrammed in the SU.

145    At p 4 line 29 to p 5 line 14, an important connection is made, in the case of the illustrative embodiment, between scanning and the concept of a characteristic of a communication:

Further, there may be different types of scanning that a SU performs. An SU may be programmed to perform scan based upon a characteristic of the active transmission such as whether the active transmission is voice, data, group, individual, emergency, and non-emergency. For example, a scanning SU may be programmed to scan for channels only carrying voice transmissions. Further, a scanning SU may be programmed to scan for channels only carrying data transmissions. Further yet, a scanning SU may be programmed to scan for channels carrying voice transmissions that are addressed to individual SUs and not voice transmissions that are addressing talkgroups. Further yet, a scanning SU may be programmed to scan for channels carrying data transmissions that are addressed to individual SUs and not data transmissions addressing talkgroups. Another example, a scanning SU may be programmed to scan for channels carrying any emergency transmissions regardless of the group that the active transmission is associated with. Yet another example, a scanning SU may be programmed to scan for channels carrying only non emergency transmissions regardless of the group that the active transmission is associated with. As can be imagined, there are numerous examples combining the characteristics to program a scanning SU to only search for specific active transmissions and the examples listed above are only illustrative and not exhaustive.

146    There appear to be six characteristics discussed but in fact they may be grouped into three sets of pairs each member of which is complimentary. For example, a communication is either a voice communication or a data communication. It is either addressed to a group or to an individual. It is either an emergency transmission or it is not. These binary pairs and their susceptibility to being represented by bits is a matter to which it will be necessary to return. As the passage describes, the scan function can be set so as to scan for channels which are only carrying voice transmissions. Or it could be set to scan for communications which are both voice transmissions and addressed to an individual subscriber unit. By doing this, the scan function is able to exclude communications which are not of interest to the subscriber unit. For example, if it is set to scan for voice communications addressed to an individual subscriber unit, the fact that the communication is not of that nature can be discerned from the characteristics. I return below to how the illustrative embodiment in fact does this.

147    The description then introduces Figures 2A and 2B which are important for the debate between the parties. Between the two figures is a single flow chart. Figure 2A is concerned with how the illustrative embodiment processes a voice transmission and Figure 2B deals with a data transmission. They are as follows:

148    It will be seen that Figure 2A is connected to Figure 2B at Block 226. The explanation of Figure 2A occupies much of the specification. It begins at p 5 lines 15 to 30:

Referring to FIG. 2, in operation, an SU performs the function of scanning by tuning to a specified channel enumerated in a scan list preprogrammed in the scanning SU (Block 202). As is known in the art, a channel is also known as a “personality” where a personality is typically a radio frequency (RF) with additional qualifying information. The scanning SU pauses on the selected personality for a specified time period and tests whether an RF carrier is detected (Block 204). In one embodiment, a scanning SU which is programmed to scan only for voice transmissions pauses for 25 msecs before continuing.

As is known in the art, the specified time period depends upon the type of signal expected to be received by the scanning SU such as analog voice, FDMA digital, and TDMA digital. Further, the specified time period may depend upon the type of scan being performed. As mentioned above, the type of scan may depend upon a characteristic of the active transmission such as whether the active transmission is voice, data, group, individual, emergency, and non-emergency. For example, if the scanning SU is programmed to scan for channels only carrying data transmissions, then it may wait for 65 msecs before continuing.

149    The significance of the time delays was not something which the evidence touched upon and appears immaterial to the debates between the parties. It is not obvious to me why the pause times might vary depending on the nature of the signal expected to be received or why the description includes reference to FDMA and analogue systems when it is concerned only with TDMA systems. In any event, this does not matter.

150    The description then continues at p 5 line 31 to p 6 line 12:

If an RF carrier is present, then the scanning SU remains on the selected personality and performs synchronization (Block 206). In an illustrative embodiment, performing synchronization between the BR and the SU involves waiting a predetermined period of time for detecting a time slot synchronization signal. The time slot synchronization signal is a 48 bit (also known as 24 symbols) frame sync word. The time slot synchronization signal identifies the center of a TDMA burst and the type of communication present on the TDMA channel so that a receiver in the scanning SU may be able to receive transmissions on the TDMA channel. Performing synchronization is complete upon detection of the time slot synchronization signal within a predetermined period of time. In one embodiment, the scanning SU must receive the time slot synchronization signal within 335 msecs. If the communication between the SU and the BR is in synchronization or the SU is successfully able to perform synchronization between the BR and the SU, then the SU determines a color code for the active transmission on the channel (Block 208).

151    Synchronisation is, as I explained above in Chapter II, an essential element of TDMA architecture. The reference to colour code at p 6 lines 11 to 12 harks back to the explanation of colour codes at p 3 line 30 (discussed above). The description then continues at p 6 lines 13 to 20:

As is known in the art, regardless of whether a carrier is detected (Block 202), a scanning SU that receives a frame synchronization message further decodes the personality. Thus, if frame synchronization is performed, then the scanning SU remains on the personality an additional amount of time to determine whether there is a match of the color code for the active transmission on the channel (Block 208). If there is not a match of the color code (Block 208), frame synchronization (Block 206), or carrier detect (Block 204), then the scanning SU tunes to the next channel in the preprogrammed scan list (Block 220).

152    At least for the illustrative embodiment, a failure to establish the presence of a carrier on the RF, or if having done so, if frame synchronisation is not achieved or, if it is, if the colour associated with the communication does not match the colour of the subscriber unit, then it moves to the next channel. If all of those matters are, on the other hand, satisfied then it follows that the subscriber unit has detected a carrier signal, has achieved frame synchronisation, and has determined that the subscriber unit and the base radio sending the communication are part of the same colour group. In this circumstance, the illustrative embodiment then decodes what it refers to as an ‘activity update message’. This appears from p 6 lines 21 to 27:

If there is a match of the color code for the active transmission on the channel, then the scanning SU remains on the channel and decodes a specific CACH message termed an “activity update” message 300 (Block 210). In an illustrative embodiment, the activity update message 300 is a 4-burst CACH message used to assist in identifying whether there is an active transmission (also termed “activity”) on the channel. The activity update message 300 provides information that indicates whether the scanning SU should dwell on the channel or should resume scanning.

153    The nature of the four CACH bursts is described a little later. The description then continues to describe the activity update message used in the illustrative embodiment in more detail. It does so by reference to Figure 3 which is extracted above at [142].

154    This diagram is not easy to follow. However, it is reasonably clear that its four horizontal layers represent the four CACH bursts which, as I have said, are either 8 or 4 bits in length (or 2.5 msec). Although, as will shortly be seen, the description of the illustrative embodiment explains the lower three horizontal layers in terms which are clear, this is not so in relation to the first layer. It is not clear, for example, what the ‘4-BURST CACH MSG. OPCODE (4 bits)’ is. Since it is an opcode, I am inclined to conclude that it is an instruction to the subscriber unit to receive the following three CACH bursts as data. The view that the opcode is part of an instruction set is supported by an observation appearing later in the description where it is contrasted with the balance of the activity update message which is said to be data (‘besides the opcode field 302, the rest of the activity update message 300 is considered to be data’: p 7 lines 19 to 20).

155    Returning then to the explanation of Figure 3, the description continues in these terms at p 6 line 28 to p 7 line 14:

As shown in FIG. 3, the activity update message 300 includes an activity field 304, 306 specific to each timeslot that indicates whether the channel is presently supporting a call or transmission on either of the timeslots. For example, as shown in FIG. 3, one-bit field 304 indicates whether timeslot one is supporting a call or transmission and one-bit field 306 indicates whether timeslot two is supporting a call or transmission where a value of “0” indicates that the timeslot is not active and “1” indicates an active transmission on the time slot. If there is an active transmission on the timeslot (Block 211), then the scanning SU determines whether the active transmission is of interest to the scanning SU. Otherwise, the scanning SU moves to the next personality in the preprogrammed scan list (Block 220).

Further, if an active transmission is present, then the activity update message 300 also has other information to identify the type of transmission. For example, the transmission may be voice, data, an emergency, talkgroup or individual transmission as shown in FIG. 3. As shown in FIG. 3, a voice or data transmission is signaled by one-bit fields 314, 318 where a value of “0” indicates that the active transmission is a voice transmission and “1” indicates that the active transmission is a data transmission. As shown in FIG. 3, an emergency or non emergency is signaled by one-bit fields 312, 316 where a value of “0” indicates that the active transmission is a non emergency transmission and “1” indicates that the active transmission is an emergency transmission.

156    There is much which is important in this passage for an understanding of what the dispute between the parties is. The first matter to understand concerns the second row which contains 8 bits marked as A1, E1, D1, I1, A2, E2, D2 and I2. It will be recalled that the illustrative embodiment concerns a two timeslot TDMA system. The first four bits concern timeslot 1 and the second four concern timeslot 2. The bits A1 and A2 (the ‘activity indicators’) indicate whether activity is present on timeslot 1 and 2 respectively, 1 signifying activity and 0 signifying no activity. The bits E1 and E2 signify the presence of an emergency broadcast if set to 1 or no emergency broadcast if set to 0. The bits D1 and D2 signify a data communication if set to 1 or a voice communication if set to 0. The bits I1 and I2 indicate whether the transmission is intended for an individual if set to 1 or a talkgroup if set to 0.

157    It will be seen from the nature of some of these fields that the decoding of the four burst CACH message and the rendering of these 8 bits is unlikely, except perhaps in the case of the emergency bit, to provide enough information to the subscriber unit to ascertain that the communication to which the activity update message relates is, in fact, a communication which the subscriber unit wishes to receive. What most of them do is to operate either in a negative fashion to indicate that the communication is not one in which the subscriber unit is interested, or alternatively, in a provisional fashion, to indicate that the communication could be of interest. For example, if the activity bit is set to no activity then the subscriber unit may move on to the next channel. Similarly, if the subscriber unit is not interested in data transmissions the fact that the D1 bit is set to 1 provides the subscriber unit with sufficient information to know to move on to the next channel.

158    Because it will be relevant when it comes to the claims, it is to be noted also that the activity bit has the consequence that the subscriber unit will not continue scanning on a timeslot which is indicated to be inactive. This activity indicator is important for the debate between the parties. Also important are the other bits in the second row in Figure 3 which, in various ways, signify the presence or absence of communications with certain characteristics. It is possible to think of these separate signifiers as a form of information. It is also possible to think of the activity indicator as a form of information. As will be seen in due course, the claims in the 355 Patents speak in terms of a ‘first information’ (signifying whether activity is present on a timeslot) and the existence of a ‘second information’ (which signifies whether the communication is of interest to the subscriber unit).

159    Another matter worth noting at this stage is an implication flowing from the inclusion of the activity update message in the 2.5 msec interval at the end of each 30 msec burst. Plainly enough, the activity indicator is useful for saving the subscriber unit from wasting time scanning an inactive timeslot. The other bits (E, D and I) perform a similar although less dramatic purpose. In terms of the signal architecture in the illustrative embodiment, the 2.5 msec is used not just to signal activity but also to convey other information about the communication. Whether this is a feature of the invention as claimed, as opposed to a feature of the illustrative embodiment, is an issue between the parties.

160    The description then continues at p 7 lines 19 to 23:

Further, besides the opcode field 302, the rest of the activity update message 300 is considered to be data and is populated by information from a full Link Control (LC) message for a voice transmission and from a data header for a data transmission. For example, the emergency one bit fields 312, 316, the group one bit fields 320, 322, and the addresses 308, 310 are recovered from the LC message or a data header.

161    Here will be seen the reference to the opcode not being data which I have mentioned above. It appears from this that in the illustrative embodiment, the data in the activity update message is populated by information from a full LC message for a voice transmission or from a data header for a data transmission. The description does not explain at this point what a full LC message or a data header is. However, it would appear that it contains at least all of the information which is in the activity update message. I return to the topic of the full LC message shortly.

162    The description then continues at p 7 line 24 to p 8 line 2:

If an active transmission is present and if the scanning SU is programmed to check the active transmission (Block 222) for a transmission addressed to a SU of interest, then the scanning SU determines whether the active transmission is addressed to a SU of interest (Block 212). Otherwise, the scanning SU checks to see if the scanning SU is programmed to receive the active transmission (Block 224). For example, the scanning SU may be programmed to receive all emergency calls regardless of identification (ID) of the source or destination of the active transmission. If the active transmission is of interest to the scanning SU, then the speaker is unmuted and audio is rendered to the user of the scanning SU (Block 218). Otherwise, the scanning SU moves to the next personality in the preprogrammed scan list (Block 220).

163    This passage and Blocks 222, 212 and 224 are, at first blush, a little obscure. However, they are important and it is necessary to dispel the obscurity. First, it will be noted that Block 222 is only reached after it has been determined at Block 211 that there is an active transmission on the timeslot. Translated back into Figure 3, this means that bit A1 (or if timeslot 2 is involved, bit A2) has been set to 1. Secondly, Block 222 reflects the programming of the subscriber unit. It will either be programmed to check for identification or it will not. Thirdly, if is programmed to check for identification, then the subscriber unit proceeds to Block 212. Block 212 is further expanded upon in the following paragraph. Fourthly, if the subscriber unit is not programmed to check for identification then it proceeds to Block 224 and checks to see if the transmission is nevertheless of interest. This it does by checking the remaining bits in the same row of Figure 3. As the description notes, if the subscriber unit is programmed to receive emergency transmissions and the emergency bit is set in the second row then the speaker is unmuted and the audio rendered (Block 218).

164    It is then necessary to say a little more about the process of identification if the subscriber unit has been programmed to receive transmissions addressed to a subscriber unit of interest. As I have explained above, the process of identification does not take place at Block 222 which instead just reflects a programming choice which has been made in the subscriber unit. If it is programmed to see if the transmission is from a subscriber unit of interest, then the actual process of identification occurs at Block 212. Of this process the description then continues in these terms at p 8 lines 3 to 15:

Further yet, if an active transmission is present, the activity update message 300 also identifies the SUID or TGID of the active transmission. As shown in FIG. 3, the identification field 308, 310 is an 8-bit hashed field as shown in FIG. 3. Further, because there are a limited number of bits in the activity update message 300, the ID field 308, 310 is hashed. For example, if the active transmission on timeslot 1 is directed to SU 16 and SU 16 is identified by a 24 bit SUID, then the ID field 308 is hashed to 8 bits. Another example is an active transmission on timeslot 2 directed to an SU in a talkgroup, e.g. SU 12, where the talkgroup is identified by a 16 bit TGID.

Thus, the ID field 310 is hashed from the TGID of 16 bits to 8 bits. As is known in the art, there are many algorithms that can be used to perform the function of hashing and one such well known algorithm is a CRC-8 checksum with a generating polynomial of g(x)=x8+x2+x+1. With an input of a 16 bit TGID or a 24 bit SUID, the output is an 8 bit CRC hashed ID field 308, 310 as shown in FIG. 3.

165    This takes one back once again to Figure 3. The third and fourth rows of Figure 3 are 8 bits in length. The bottom row is for Channel (timeslot) 2 and the second from the bottom row is for Channel (timeslot) 1. As has previously been noted, the activity update message is sent across both timeslots. To that extent it contains redundant information, for the information in bits b0 to b3 concern timeslot 2 in the row which indicates the characteristics of the transmission whilst those at b4 to b7 concern timeslot 1. Similarly, the two 8 bit ‘hashed IDs’ are each only relevant to one of the two timeslots. As above, the SUID and TGID are shorthands for ‘subscriber unit ID’ and ‘talkgroup ID’.

166    The immediate problem facing the illustrative embodiment is that the SUID is 24 bits long and the TGID is 16 bits long. The two ID fields in the activity update message are, however, only 8 bits long. The passage effectively teaches that the SUID and TGID are to be subject to a compression algorithm which will reduce them in length to an 8 bit structure. The expression ‘hashed ID’ therefore refers to a compressed form of the SUID and the TGID. As will be seen shortly, an ID match at Block 212 does not definitively determine that the transmission is for the subscriber unit of interest. As was accepted by all parties, this is because the compression algorithm can cause more than one subscriber unit identified by a 24 bit SUID to have the same 8 bit hashed ID (a similar problem affects subscriber units identified by a 16 bit TGID). It is therefore necessary for a complete ID check to be done. This is apparent from Blocks 213, 226 and 214 (if the transmission is a voice transmission) and from Blocks 213, 226 and, in Figure 2B, Blocks 228, 230, 232 and 234 (if the transmission is a data transmission).

167    The description returns to these matters shortly, but before it does so it notes that the activity update message may be received before the colour code of the active transmission is known. This it says at p 8 lines 16 to 22:

As is known in the art, the activity update message 300 may be received before knowing the color code for the active transmission on the channel. In any case, knowing the color code for the active transmission on the channel and whether it matches the color code of the scanning SU is important to deciding whether to stop scanning or not. As mentioned above, if there is not a match of the color code (Block 208), then the scanning SU tunes to the next channel in the preprogrammed scan list (Block 220).

168    Returning then to the process of identification, once it has been determined from the hashed IDs in rows 3 and 4 of Figure 3 that the subscriber unit the transmission is addressed to is of interest, the subscriber unit then asks whether the transmission is voice or data (Block 226). This it can do from the D bits in row 2 of Figure 3 which, it will be recalled, provide that information. So much is stated at p 8 lines 23 to 25:

If the ID field 308, 310 of the activity update message 300 matches the SUID or TGID of the scanning SU (Block 212), then the scanning SU determines whether the active transmission is voice or data (Block 213).

169    It is useful to pause at this point and to note what might not otherwise be obvious: that the flow chart in Figure 2A therefore uses all four of the characteristic bits in row 2 of Figure 3. The activity bit (‘A bit’) is used at Block 211 to determine whether there is activity on the channel or not. The emergency bit (‘E bit’) is used at Block 224 to determine, if the transmission is not directed to a subscriber unit of interest, whether it is an emergency transmission or not and, if it is an emergency transmission, unmutes the speaker. The individual bit (‘bit I’) is used at Block 224 to determine whether the transmission is directed to an individual or a talkgroup. Finally, the data bit (‘D bit’) is used at Block 226 to determine after identification at the level of the hashed IDs has occurred, whether the transmission is voice or data. The illustrative embodiment therefore deploys all four of the characteristic bits in the second row of the activity update message as well as the hashed IDs (and does so in respect of both timeslots).

170    This understanding of the invention depicted in Figure 2A is important for the construction issue between the parties. The language of claim 1 (to which I will return in more detail shortly), requires the invention to determine whether the activity is of interest to the subscriber unit and if it is, to remain on the channel to receive the activity. Hytera submits that the determination of whether the activity is of interest can happen only once and cannot be, as Block 212 suggests it can be, provisional. Put another way, under Hytera’s construction, the subscriber unit cannot decide that the transmission might be of interest and then carry out further acts to determine whether it actually is of interest. It will be apparent from what has been said in the preceding paragraph that in Figure 2A, this is not what is happening except in the case of an emergency transmission. In that case, the determination that the transmission is an emergency transmission, because the E bit is set to 1, leads the subscriber unit to receive the audio. However, leaving aside the position of the activity bit itself (which fits into claim 1 in a different way), all of the other information in the activity update message leads to determinations which are at best provisional. Thus, the matching of the hashed IDs at Block 212 (of which more below) requires two further determinations to be made before any audio is received: a determination using the D bit (data or voice) that the transmission is a voice communication (Block 226) and a further determination that there is a full ID match after decoding the full LC message (Block 214) (I return to the full LC message in more detail below). The information in the D bit in the activity update message also requires further determination. If the transmission is voice (Block 226), then the full LC message must be received and an ID match performed (Block 216). On the other hand, if the transmission is data (Block 226), then the subscriber unit must go through the ballet in Figure 2B which involves several steps including potentially an ID match at Box 234. In any event, the point is the same: only in the case of the E bit does the invention in Figure 2A operate in accordance with claim 1 construed as Hytera would have it. Everything else in Figure 2A is outside claim 1 construed in that fashion.

171    The description then continues at p 8 line 26 to p 9 line 11 in these terms:

If the active transmission is data (Block 226), then the scanning SU remains on the channel to recover the data message (Block 228) and waits until the end of the data transmission to receive a data terminator (Block 230). In an alternative, the scanning SU remains on the channel to receive embedded qualifying information.

Continuing, the data terminator is decoded to identify addressing identification (or an “ID”) (Block 232). If the ID is of interest to the scanning SU (Block 234), then the data message is further processed. Otherwise, the scanning SU tunes to the next channel in the preprogrammed scan list (Block 220). Continuing, the scanning SU determines whether confirmed delivery is requested (Block 236) for the data message.

If confirmed delivery is requested, then the data message is processed until the entire data message is recovered (Block 238). In one embodiment, recovering an entire data message is performed by sending Selective Automatic Repeat Request (SARQ) messages to the BR. When the entire data message is recovered, the scanning SU tunes to the next channel in the preprogrammed scan list (Block 220). If confirmed delivery is not requested, then the scanning SU waits on the channel a predetermined amount of time for a possible redundant or subsequent transmission (Block 242). At the expiration of the predetermined amount of time, the scanning SU tunes to the next channel in the preprogrammed scan list (Block 220).

172    These relate to what occurs if the transmission is a data transmission. The data aspect of Figure 2B was not the subject of contention between the parties and as such may be passed over. The description then continues at p 9 lines 12 to 28:

If the active transmission is voice (Block 226), then the scanning SU remains on the channel to perform a full link control (LC) qualification of the active transmission by decoding an LC message which identifies whether the active transmission is addressed to an individual SU or a talkgroup, an emergency or non emergency, and the source and destination of the active transmission (Block 214). In an illustrative embodiment, the LC message is a 7-burst CACH message. Performing full LC qualification means that the scanning SU waits for a LC message on the timeslot of interest and decodes an ID field of the LC message to determine whether the active transmission is of interest to the scanning SU. In an illustrative embodiment of the wireless communications landscape 100, because LC messages are available once every 360 msec, having to wait to decode a full LC message is time consuming for the scanning SU. If the ID field of the LC message is an ID of interest to the scanning SU (Block 216), then the speaker is unmuted and audio is rendered to the user of the scanning SU (Block 218). If the ID field of the LC message is not of interest to the scanning SU (Block 216), then the scanning SU tunes to the next channel in the preprogrammed scan list (Block 220).

173    It will be recalled from above that the full LC message at least includes the information in the activity update message. From this it also appears that it contains the full SUID or TGID. Consequently, it is apparent that the full LC is larger than the activity update message. This is confirmed by the fact that whereas the activity update message is transmitted as four bursts of 2.5 msec duration (at the end of each 30 msec burst), the full LC is transmitted in seven bursts (presumably of 56 bits). The statement that the full LC message is available every 360 msec suggests that it is available after 12 bursts (recalling that the bursts take 30 msec). The activity update message takes four bursts and the full LC message takes seven bursts. This suggests, but it is unclear, that the activity update message bursts and the full LC message bursts alternate at the end of the 30 msec block, i.e. one burst uses the 2.5 msec for the next burst of the activity update message and the following burst uses the 2.5 msec for the next burst of the full LC message. In any event, it is clear from what the description says in the next paragraph that the activity update message is received in full more often than the full LC message.

174    The description then continues at p 9 line 28 to p 10 line 3:

If the ID field 308, 310 of the activity update message 300 does not contain an id that is of interest to the scanning SU (Block 212), then the scanning SU moves to the next channel in the preprogrammed scan list. In such a case, the scanning SU does not have to wait for a LC message. Because the LC message only is sent once every 360 msec, not having to wait for a LC message improves the time that the scanning SU spends during the function of scanning. By not having to wait for a LC message, the scanning SU is able to quickly determine that the active transmission is not of interest and the scan function is improved.

175    The point being made here is that the activity update message operates as a rapid negative criterion of exclusion and is faster than waiting for a full identification through the full LC message. The description then continues at p 10 lines 4 to 12:

As is known in the art, the timing of events relating to color code, the activity update message 300, and the LC message may occur in any order. For example, the activity update message 300 may be received by the scanning SU before 1) the color code of the active transmission is known or 2) the full LC message is received. Also, a full LC message may be received before 1) the activity update message 300 is received by the scanning SU or 2) the color code of the active transmission is known. Further, as shown in FIG. 2, the color code of the active transmission may be known before 1) the activity update message 300 is received by the scanning SU or 2) the full LC message is received.

176    There was not a lot of discussion of this. However, it appears that its import is that where the subscriber unit actually receives the full LC message before the activity update message, it can use the full LC message.

177    The description then continues at p 10 lines 13 to 26:

In any case, determining whether to remain on the channel and render audio to the user of the scanning SU is based upon whether the received information is of interest to the user. Specifically, a match of the color code and the full LC message stops the function of scanning and renders audio to the user of the scanning SU. A match of the color code and ID field 308, 310 of the activity update message 300 stops the function of scanning but requires a match of the full LC message before rendering audio to the user of the scanning SU.

In an illustrative embodiment, a match of the ID field 308, 310 indicates that the active transmission may be of interest to the scanning SU. In such a case, the scanning SU remains on the channel and performs Link Control (LC) qualification of the active transmission before committing itself to remaining on the channel and rendering audio to the subscriber unit user. Alternatively, if there is not a match of the ID field 308, 310 then the scanning SU continues to scan with the next personality in the scan list.

178    This is an important passage and highlights the difference between the full LC message and the activity update message. The matching of colour codes, it will be recalled, relates to whether the subscriber unit is associated with the base radio which has sent the transmission. A matching of the ‘ID field 308, 310’ is a reference to a matching of the hashed ID codes in the activity message (that is, the last two rows of Figure 3). What appears from the last sentence reflects the fact, referred to above, that by compressing the SUID and TGID using a compression algorithm, a certain amount of information is lost in the process so that a match between the compressed 8 bit SUID or 8 bit TGID in the activity update message and the 24 bit SUID or 16 bit TGID which the subscriber unit is programmed to be interested in, does not entail with certainty that the SUID and TGID actually match. Only when the full LC message is received (and decoded) can a match be carried out using the full 24 bit SUID or 16 bit TGID. It is only then, according to this paragraph, that audio is rendered to the user.

179    This paragraph is important for the construction issues between the parties. As alluded to above, Hytera submits that on its proper construction, the expression in claim 1 ‘determining whether the activity is of interest to the subscriber unit’ entails a decision making process that is once and for all; or, to put it another way, that once the subscriber unit has determined that activity is of interest to it, that is the end of the process and nothing more remains to be done but to remain on the channel to receive the communication. It is not necessary to say anything about the correctness of this argument at this stage, but it will be noted that the use of the activity update message as described in this paragraph (and more generally in the illustrative embodiment) does not accord with such a construction. The determination that the activity is of interest because there is a match in the hashed IDs is inherently provisional in this paragraph and there remains the further steps of checking the full LC message before the subscriber unit commits to remaining on the channel to receive the activity. For present purposes, what should be taken away from this paragraph is that it uses the expression ‘is of interest to the user’ (at p 10 lines 14 to 15) in a way which suggests that ‘interest’ may be a provisional state of affairs.

180    The description then continues at p 10 lines 27 to p 11 line 5:

By utilizing an activity update message 300 in the wireless communications landscape 100, the time spent while scanning is reduced. For example, in the embodiment described, a scanning SU is able to identify an active transmission of no interest on average in 152 msec. In a worst case, a scanning SU takes up to 335 msec to identify an active transmission of no interest. Without the use of an embodiment of the present invention, experimentation has shown that in an average TDMA system, a scanning SU is able to identify an active transmission is of no interest on average in 512 msec and in the worst case in 695 msec. Further, without the use of an embodiment of the present invention, experimentation has shown that in an average FDMA system, a scanning SU is able to identify an active transmission is of no interest on average in 360 msec and in the worst case in 540 msec.

181    This passage explains the point of the activity update message and confirms that its advantage lies in its ability more rapidly to conclude that a transmission is not of interest. The illustrative embodiment is able to determine that a transmission is not of interest on average in 152 msec whereas without the use of the activity update message this takes on average 512 msec. In other words, the illustrative embodiment shows that the use of the activity update message allows the subscriber unit to ascertain that a transmission is not of interest more than twice as fast.

182    The description then continues at p 11 lines 6 to 12:

Further yet, by utilizing an activity update message 300 in the wireless communications landscape 100, a SU that is a party to a call may quickly join the call if the SU is not currently a party to the call. Such an SU is called a late entry SU. For example, in the embodiment described, a late entry SU may join a call in a minimum of 120 msec. In a worst case, the late entry SU may join in about 300 msec. Without the use of an embodiment of the invention, experimentation has shown that a late entry SU takes about 360 msec and in the worst case about 720 msec to join a call.

183    This is a reference to the problem of late entry subscriber units. Nothing particularly turns on this. Finally, the description concludes at p 11 lines 13 to 21 in these terms:

While the invention has been described in conjunction with specific embodiments thereof, additional advantages and modifications will readily occur to those skilled in the art. The invention, in its broader aspects, is therefore not limited to the specific details, representative apparatus, and illustrative examples shown and described. Various alterations, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Thus, it should be understood that the invention is not limited by the foregoing description, but embraces all such alterations, modifications and variations in accordance with the spirit and scope of the appended claims.

184    Nothing turns on this.

CONSTRUCTION

The Proper Construction of Claims 1-6 and 10

185    Claims 2-6 are dependent on claim 1. Claim 7 (which is not sued upon) is said by Motorola to be relevant to the construction of claim 1. Claim 7 is dependent on claim 6. Claim 10 is an independent claim.

Claim 1

186    It is useful to set claim 1 out again, this time identifying its integers with numerical parentheses:

1.     A method for scanning a TDMA channel by a subscriber unit in a wireless communications landscape, wherein the subscriber unit is operationally connected to at least one base radio over a plurality of channels, the method including the steps of:

[1]     locking onto a channel of the plurality of channels by the subscriber unit wherein a subset of the plurality of channels is preprogrammed in a list in the subscriber unit;

[2]     transmitting from at least one base radio a control message to the subscriber unit wherein the control message has a first information which informs the subscriber unit of activity present on the channel of the plurality of channels;

[3]     receiving and decoding the control message for the first information by the subscriber unit; and

[4]    if the first information indicates that activity is present on the channel of the plurality of channels, then

[5]     determining whether the activity is of interest to the subscriber unit by comparing a second information in the control message with a third information preprogrammed in the subscriber unit and

[6]     if the activity is of interest to the subscriber unit, then remaining on the channel of the plurality of channels to receive the activity present on the channel.

187    The parties are in disagreement about the construction of integers 5 and 6 and in particular about the meaning of the phrases:

(a)    ‘determining whether the activity is of interest to the subscriber unit’; and

(b)    ‘remaining on the channel … to receive the activity’.

The Competing Constructions

188    Motorola submitted that the first expression (‘determining whether the activity is of interest…’) was a reference to an assessment that the activity is of relevance or utility to the subscriber unit, in the sense of having some bearing on a subsequent communication step. It involved evaluating that the activity was of interest based on satisfaction of the test appearing in the fifth integer of claim 1, i.e. ‘by comparing a second information in the control message with a third information preprogrammed in the subscriber unit’. It did not, however, exclude the possibility of further steps including a further confirmation.

189    Hytera, on the other hand, says that both phrases are clear and prescriptive and require a determination to be made as to whether the activity is of interest to the subscriber unit and, if it is, that the subscriber unit must remain on the channel to receive the activity. On this view of claim 1, the method does not include the possibility that the determination of whether the activity is of interest to the subscriber unit may happen more than once. Motorola described Hytera’s construction as involving a once and for all determination. I consider this an accurate description. Whilst Hytera said that these were Motorola’s words and not its own, in argument Mr Dimitriadis SC accepted that the effect of Hytera’s construction was that once a determination was made, the process was concluded: T88.11.

190    The debate between the parties is best illustrated by reference to one of the preferred embodiments referred to in the specification and the figure with which it is accompanied. The relevant figure is Figure 2A. Figure 2A is described at p 2 lines 7 to 8 of the detailed description as ‘a flow diagram of an example method for providing channel access for voice transmissions’. What is key for present purposes are Blocks 212, 216 and 222 in Figure 2A (which is already set out above, but is also set out again below for convenience).

191    It will be seen that ‘ID Match’ appears at Blocks 212, 216 and 222 although in Block 222 the wording is slightly different. It should also be noted that in the order specified by the flow chart, the blocks are addressed in the order 222, 212 and 216. Jumping somewhat ahead to make it easier to follow, the parties agree that the reference to ‘ID Match’ at 212 is a reference to that part of integer 5 of claim 1 which refers to ‘determining whether the activity is of interest to the subscriber unit’. They also agree that the reference to ‘ID Match’ at Block 216 is an example of a determination of whether the activity is of interest to the subscriber unit. They disagree, however, on whether this second reference is within claim 1. The difference between them in relation to claim 1 is thus whether ‘determines’ means determined once and for all (as Hytera in substance contends) or whether it does not exclude the possibility of further subsequent determination (as Motorola contends).

192    If Motorola’s construction is correct, then both Block 212 and Block 216 may be a ‘determination’ within the meaning of claim 1. On the other hand, if Hytera is right, then the fact that it is not in dispute that a ‘yes’ answer to Block 212 is a determination within the meaning of claim 1 necessarily implies that Block 216 cannot be a determination within the meaning of claim 1.

193    Most, but not all, of the debate between the parties was generated by the interpretative tension between claim 1 and the preferred embodiment illustrated in Figure 2A. Motorola emphasises that claim 1 is to be interpreted in the context of the specification as a whole, including in light of the nature and purpose of the invention disclosed, and the CGK in the field. The presence in the preferred embodiment illustrated in Figure 2A of two steps involving a determination that the activity was of interest to the subscriber unit, led Motorola to submit that claim 1 should be construed in that light. On the other hand, Hytera emphasises that it is the language of the claims which must be construed and that it is not legitimate to expand the boundary of the monopoly as fixed by the words of claim 1 by adding a gloss drawn from the preferred embodiment illustrated in Figure 2A or the description of that embodiment in the specification. Both statements of principle are correct. The main question, therefore, is whether what Motorola seeks is a legitimate contextual construction of the word ‘determine’ or an impermissible attempt to gloss claim 1 by reference to one of the preferred embodiments.

194    Turning then to the precise issues between the parties, Motorola submitted as follows. First, as noted in the previous paragraph, it submitted that Block 212, and the preferred embodiment it illustrated, showed that the determination could be non-conclusive. There was no dispute that Block 212 is non-conclusive and I accept Motorola’s submission that the preferred embodiment and Block 212 involve a determination of whether the activity is of interest to the subscriber unit which is not on a once and for all basis. I also accept, and it was not disputed, that Block 216 involves another step where it is determined whether the activity is of interest to the subscriber unit. I also accept Motorola’s submission that the word ‘determines’ when used in the part of the description of the preferred embodiment corresponding to Block 212 must bear a meaning which encompasses the possibility of a subsequent determination at Block 216. The relevant part of the specification was at p 7 lines 24 to 27:

If an active transmission is present and if the scanning SU is programmed to check the active transmission (Block 222) for a transmission addressed to a SU of interest, then the scanning SU determines whether the active transmission is addressed to a SU of interest (Block 212).

195    I do not accept Motorola’s submission that Mr Kuhrt had agreed that the word ‘determines’ when used in the patent did not exclude a subsequent further step of confirmation. The relevant evidence is at T678.34-679.24. It was clear that Mr Kuhrt was being cross-examined about the preferred embodiment rather than claim 1. Although it is true that one of the questions he was asked included a reference to the meaning of the word ‘determines’ ‘as used in the patent’, I do not think Mr Kuhrt can be taken in the full context of the questions he was being asked to have been expressing a view about the meaning of that word in claim 1.

196    Secondly, Motorola submitted in relation to integer 6 of claim 1 that there was a distinction between ‘remaining on the channel’ (the words used) and committing itself to remain on the channel. This distinction was also to be found in the preferred embodiment. The relevant portion of the description of the preferred embodiment was at p 10 lines 20 to 24:

In an illustrative embodiment, a match of the ID field 308, 310 indicates that the active transmission may be of interest to the scanning SU. In such a case, the scanning SU remains on the channel and performs Link Control (LC) qualification of the active transmission before committing itself to remaining on the channel and rendering audio to the subscriber unit user. Alternatively, if there is not a match of the ID field 308, 310 then the scanning SU continues to scan with the next personality in the scan list.

197    The reference to fields 308 and 310 takes one again to Figure 3. Figure 3 is described at p 2 lines 9 to 10 as ‘an example of a specific Common Announcement Channel [CACH] message called an Activity Update’.

198    Figure 3, which I have already extracted above, is once again as follows:

199    Motorola submitted, and I accept, that this is a discussion of what occurs in the preferred embodiment when there is a match of the ‘hashed ID’. It submitted, and I accept, that this shows that the subscriber unit would remain on the channel until committing itself to remain on that channel. I do not accept Hytera’s submission that the reference in p 10 line 21 to ‘may’ alters this analysis. Hytera’s answer to this was that what was happening at p 10 line 21 when the question was posed whether the activity ‘may be of interest’ was not relevant to the construction of integer 6 of claim 1 because the expression there used was ‘is of interest’. What the preferred embodiment did when the activity ‘may be of interest’ threw no light on that issue. On this view, the kind of commitment to remain on the channel required by integer 6 only occurred when the comparison with the full ID field in the full LC message took place (at p 10 lines 22 to 24). I do not accept this submission. The passage at p 10 lines 20 to 24 clearly contemplates a situation where remaining on the channel has a contingent quality about it at one time and a definitive quality at another. I also do not accept Hytera’s submission that its position is supported by the reference to ‘is of interest’ at p 10 lines 14 to 15. The following sentence shows that two determinations take place before that occurs (i.e. colour matching and the full LC message).

200    I therefore accept that this portion of the description of the preferred embodiment observes a distinction between remaining on the channel and committing itself to remain on the channel. The question, however, is whether this distinction accords with the meaning of ‘remaining on the channel’ in integer 6 of claim 1. Professor Rangan thought that ‘remaining on the channel’ did not mean committing itself to remaining on the channel. Mr Kuhrt accepted that this was an available reading of integer 6 of claim 1 although it was not the one which he preferred. In his view, ‘remaining on the channel’ was what happened after it was determined that the activity was of interest to the subscriber unit.

201    Thirdly, Motorola submitted (in relation to integer 6 of claim 1) that the expression ‘remaining on the channel … to receive the activity present on the channel’ was an example where the use of the infinitive ‘to receive’ connoted a purpose or function. It followed that so parsed, integer 6 of claim 1 did not have as one of its elements the actual receipt of the activity. Whilst I accept the grammatical parsing, on balance, I regard this consideration as of little weight as it appears to involve giving considerable significance to the use of the infinitive as the expression of a function or purpose. Whilst I would accept that such reasoning would be appropriate in the construction of a statute (see, e.g. Sunchen Pty Ltd v Federal Commissioner of Taxation [2010] FCAFC 138; 190 FCR 38 at 55 per Jessup J) it would appear to be the kind of ‘meticulous verbal analysis’ which the authorities counsel against in the construction of patents: Catnic Components Limited v Hill & Smith Limited [1982] RPC 183 at 242-243 per Diplock LJ.

202    Fourthly, Motorola submitted that the main embodiment set out in the specification plainly involved a process where an initial determination was made followed by a subsequent, more definitive determination. By this, Motorola intended a reference to the method illustrated in Figure 2A which is described at p 2 line 7 as ‘a flow diagram of an example method for providing channel access for voice transmissions’. If Hytera’s construction were correct, then it would follow that the preferred embodiment lay outside the patent. Here the point was not so much that the preferred embodiment had elements which were not within the claims but that the preferred embodiment would itself not be within the claims. This was said to be unusual and not something that a construction of the claims, in light of the patent as a whole including the specification, would ordinarily yield.

203    As I understood it, Hytera developed three answers to this. The first was in Mr Dimitriadis’ opening address at T88.35-89.18 and, although Mr Dimitriadis did not refer to the graphic elements of Figure 2A specifically, was to the effect that Figure 2A also disclosed the possibility of a single determination consistent with his construction. This argument centred on Block 224 which was said to involve a determination within integer 6 of claim 1. Assuming that to be correct, the logic of the submission is that a ‘yes’ answer to Block 224 leads to the unmuting of the speaker at Block 218 and the delivery of the transmission. In such a state of affairs, there would be but one determination. Consequently, so Hytera submitted, Figure 2A was consistent with its construction of claim 1. To the extent that it had matters in addition to claim 1 – such as Blocks 212 and 216 – this did not mean that Figure 2A did not embody claim 1: Lockwood Security Products Pty Limited v Doric Products Pty Limited [2004] HCA 58; 217 CLR 274 (‘Lockwood (No 1)’) at [69] per Gleeson CJ, McHugh, Gummow, Hayne and Heydon JJ.

204    I accept this submission. It is not the case therefore that if Hytera’s construction is correct Figure 2A does not embody claim 1.

205    The second answer was also given by Mr Dimitriadis in opening at T92.15 and was to the effect that the argument could not succeed because claim 11 in fact claimed the method ‘substantially as herein described with reference to the accompanying drawings’. Motorola did not rely on claim 11 which is no answer to the point. There may be questions about the validity of a claim such as claim 11 or at least about the manner in which it is to be interpreted. In the circumstances where I have accepted that Figure 2A does embody claim 1, it is not necessary to consider claim 11 further.

206    Hytera’s third answer appeared in a different part of its closing written submissions on claim 1 at [32(c)] and was to the effect that to the extent that any part of Figure 2A was not within claim 1, it was within claim 11. In light of my acceptance of the first argument I do not need to reach a view on this second argument.

207    In writing, Hytera also advanced three further reasons to reject Motorola’s contention about the preferred embodiment not implementing the invention on Hytera’s construction. The first was that there was no reference to an initial determination that the activity ‘is of interest’. Secondly, it was said that Motorola’s reference to ‘remaining on the channel rather than switching to the next channel’ was not the wording of integer 6 of claim 1. I accept both of these points but observe that neither appears to be responsive to Motorola’s submission unless they are understood to serve as examples of Hytera’s third argument. That third argument is that Motorola’s construction impermissibly borrows language from the specification to place a gloss on claim 1. I return to this point below.

208    In any event, for the reasons I have given, I reject Motorola’s submission that Hytera’s construction has the effect that Figure 2A does not embody the invention as claimed in claim 1.

209    Fifthly, Motorola relied upon claim 7. Claim 7 was dependent on claim 1. Motorola does not assert claim 7 in its infringement suit but rather says that claim 7 offers support for its construction of claim 1. Claim 7 refers to a process of recovering and decoding an LC message for identification information and determining whether the LC message is of interest to the subscriber unit by comparing the identification information with a fourth information preprogrammed in the subscriber unit. If there is such a match then the subscriber unit is to remain on the channel to receive the activity present on the channel. Motorola’s point is that claim 7 necessarily assumes that the determination in claim 1 cannot be once and for all and that the ‘remaining on the channel’ it contemplates need not be permanent either.

210    Motorola submitted that if claim 1 meant as Hytera contended, then claim 7 could never be enlivened. It noted the evidence of Mr Kuhrt. Mr Kuhrt was not asked by Hytera to consider the significance of claim 7 for claim 1. Under cross-examination, he agreed that if one read claim 1 consistently with claim 7 this would be a pointer that Motorola’s interpretation of ‘determining’ in integer 5 and ‘remaining’ in integer 6 of claim 1 was correct.

211    On its face, if Hytera’s construction is correct this would mean that claim 7 could never be enlivened. However, Hytera disputed that this was of any significance. It submitted that there were limits on the extent to which a dependent claim such as claim 7 can inform issues of the claim upon which it depends. If the plain meaning of a claim has the effect that one or more dependent claims are redundant then the consequence of redundancy would not drive the construction of the claim itself. For this proposition Hytera cited Davies v Lazer Safe Pty Ltd [2019] FCAFC 65 (‘Davies’) at [65] and Nichia Corporation v Arrow Electronics Australia Pty Ltd [2019] FCAFC 2 (‘Nichia’) at [41].

212    I do not think that Nichia assists Hytera. The relevant passage is at [40]-[41] in the reasons of Jagot J (with whom Besanko and Nicholas JJ agreed). There, her Honour said:

In contrast to the primary judge, I also consider claim 6 does not provide assistance for the resolution of this issue of construction. Claim 6 merely raises the same issue of construction. Claim 6 can function as a dependent claim, narrower than claim 3, whether “contains” is construed to mean “includes” or “contains only”. Either way, claim 6 is narrower than claim 3 and can depend on claim 3 because there must be at least two fluorescent materials of different compositions within the general formula to satisfy claim 6 whereas one single fluorescent material represented by the general formula would satisfy claim 3.

Nor do I consider that the existence of a degree of overlap between claims 3 and 6 provides a sound basis to prefer one construction of claims over another. Even if, as the primary judge said at [97], claim 6 is “largely redundant” because claim 3 also covers two or more fluorescent materials of different compositions represented by the general formula, the redundancy is not complete as claim 6 specifically defines and claims a sub-set of claim 3 devices. In any event, some, even extensive, redundancy in the drafting of patent claims seems more an indicator of an abundance of caution than a guide to the meaning of “contains” which appears in both claims 3 and 6 (and other claims) and thus should generally be construed as having the same meaning wherever it is used.

213    So the issue Jagot J was dealing with was whether claim 6 (which required two fluorescent materials) was made redundant by claim 3 which could be satisfied by one single fluorescent material. The point was that the trial judge had found that claim 3 could also cover two or more fluorescent materials and had concluded therefore that claim 6 was redundant (on the relevant construction). Jagot J rejected that analysis but then observed, ‘some, even extensive, redundancy’ in the drafting of patent claims seemed more to indicate an abundance of caution in the drafting of the claims.

214    That is not the situation here. The present situation is that the construction of claim 1 for which Hytera contends has the effect that there can never be an invention embodying claim 7 because the criteria of operation for claim 7 is inimical to claim 1 on which it depends. This is not a case of redundancy, therefore, but rather inconsistency. The effect of the inconsistency, it is true, is that claim 7 can never have any work to do. But to describe the problem in that way would be to obscure the textual significance of the fact that claim 7 takes as its point of departure an operation for claim 1 which is contrary to that now contended for by Hytera.

215    In Davies, the Full Court (Greenwood, White and Burley JJ) said at [65]:

Finally, in ground 6 the appellants contend that in construing claim 1, the primary judge erred at [239] by failing to construe claim 1 in the context of the dependent claims, and in particular in the context of claim 2. Having regard to the conclusion that we have reached in relation to grounds 3, 4 and 5, it is unnecessary to address this ground in detail. The appellants submit that the primary judge’s construction of integers (1.5) and (1.6) is not “harmonious” with the scope of dependent claims 2 and 8 – 11. The appellants do not, however, submit that the construction adopted by the primary judge renders those claims redundant. If that were the case, then the Court would endeavour to construe claim 1 in a manner that avoided redundancy; see Bodkin, Patent Law in Australia, 3rd ed, 2019, at [21910]. This is consistent with the proper approach to claim construction that construes claims in the context of the specification as a whole, including the other claims. Nevertheless, if the plain meaning of a claim has the effect that one or more dependent claims are redundant, then the consequence of redundancy would not drive the construction of the claim itself …

216    Again, I do not think this assists since the current circumstance does not involve redundancy in the sense being discussed.

217    Sixthly, Motorola submitted that its interpretation was more consistent with the function of the patent as a whole. This argument went as follows: the patent was to be seen as primarily concerned with a method by which a subscriber unit could make faster decisions that activity on the channel was of no interest before moving on to the next channel. On this view of the invention, the critical determination was the determination to move on to the next channel or alternatively to remain on the current channel. Textual support for this understanding of the function of the patent as a whole was to be found in two passages in the description of the invention. These were at p 10 lines 1 to 3 and p 10 line 27 to p 11 line 2. These passages are as follows:

By not having to wait for a LC message, the scanning SU is able to quickly determine that the active transmission is not of interest and the scan function is improved.

…

By utilizing an activity update message 300 in the wireless communications landscape 100, the time spent while scanning is reduced. For example, in the embodiment described, a scanning SU is able to identify an active transmission of no interest on average in 152 msec. In a worst case, a scanning SU takes up to 335 msec to identify an active transmission of no interest. Without the use of an embodiment of the present invention, experimentation has shown that in an average TDMA system, a scanning SU is able to identify an active transmission is of no interest on average in 512 msec and in the worst case in 695 msec.

218    Hytera made three points about this. First, it was said that the advantage identified was an advantage obtained by the subscriber unit moving on to the next channel where a transmission was not of interest. Secondly and by extension, Hytera submitted that its construction took account of that claimed advantage because where a determination was made that the activity was not of interest, the subscriber unit would not remain on the channel. I do not accept these submissions. Where multiple determinations are possible, the determination based on the information which is then available that the activity is not of interest causes the scan to move to the next channel. Hytera’s construction requires that to be done only once so that all of the information must be unpacked – in this way, Hytera’s construction detracts from, rather than supports the advantage which claim 1 confers.

219    Thirdly, it was submitted that many of the embodiments described in the specification were within claim 1 on Hytera’s construction and to the extent that they were not within claim 1, they were within claim 11. In response to this, Motorola submitted that a claim like claim 11 would ordinarily be understood as narrower in scope than all of the other claims and would not have the effect of broadening an invention or replacing an integer. For this proposition Motorola relied on the decision of the Full Court (Allsop CJ, Yates and Robertson JJ) in GlaxoSmithKline Australia Pty Ltd v Reckitt Benckiser Healthcare (UK) Ltd [2016] FCAFC 90; 120 IPR 406 (‘GlaxoSmithKline’) at [74]-[80]. The patent under consideration in that case was for a liquid dispensing apparatus comprising a bottle, a bottle neck liner, and a syringe, used for the administration of Children’s Panadol. Claim 1 contained a consistory statement which, read together with the specification, disclosed the essential elements of the invention: at [80]. One of those elements was that the syringe claimed in claim 1 was ‘flat-nosed’. The example given in the patent depicted a flat-nosed syringe. Claim 9, in the omnibus style of claim 11 of the 355 Patent, claimed ‘a liquid dispensing apparatus, substantially as described with reference to the drawings and/or examples’. The defendant’s product used a syringe which was not flat-nosed. The trial judge accepted the patentee’s argument that although this product did not infringe claim 1, it nonetheless infringed claim 9 because, for the purposes of that claim, it was an example of a syringe ‘substantially’ as described in the patent: [54]-[56]. The Full Court reversed this holding on appeal, stating at [80]:

The word “substantially” provides no warrant for departing from what the specification itself mandates to be the essential features of the invention. A flat-nosed syringe dimensioned as described in the consistory statement is one of the essential features of the invention. Thus, whatever work the word “substantially” is to perform in claim 9, it cannot transform a feature made essential by the description of the invention into one that is now inessential. Put another way, an embodiment that does not possess the essential features of the invention as described, cannot be one that is “substantially as described”. Thus, the word “substantially” in claim 9 does not do the work which the primary judge held that it did.

220    This holding does not squarely rebut Hytera’s argument. Hytera’s point is not that claim 11 extends the inventive monopoly in a way that transforms essential features of the invention claimed in claim 1 into non-essential ones. Rather, its point is that, to the extent the drawings depict features not found in claim 1, those features may be picked up by the omnibus claim 11. Motorola’s reliance on GlaxoSmithKline is therefore somewhat misplaced. That said, I do not accept Hytera’s argument. Claim 1 is to be construed in light of the specification as a whole, which includes the examples and drawings. The elements of claim 1 with which we are presently concerned – the subscriber unit ‘determining’ that an activity is of interest and ‘remaining on the channel’ – are elements that can readily be seen to be depicted in Figure 2A once they are understood in the way that Motorola suggests. This is therefore a construction of claim 1 which makes sense in light of the specification including the drawings. The alternative view, that Figure 2A partly depicts the narrow concept of ‘determining’ and ‘remaining’ (claimed in claim 1) and then a range of other features claimed non-specifically (via the omnibus claim 11), is not one that I have found persuasive.

221    I therefore accept Motorola’s sixth submission. It is consistent with the statement under the heading ‘Background to the Invention’ at p 1 lines 31 to 32 where the problem which the patent was intended to solve was identified: ‘Accordingly, there exists a need for scanning a TDMA channel which improves the amount of time that an SU spend scanning’. I also accept that Motorola’s construction of ‘determining’ and ‘remaining’ would achieve that purpose but Hytera’s would not.

Consideration

222    Motorola’s construction of integers 5 and 6 of claim 1 is to be preferred to that of Hytera. Their wording is capable of bearing the meaning for which both parties contend, as Mr Kuhrt accepted at least in relation to ‘remaining on the channel … to receive the activity present’. The fact that Mr Kuhrt and Professor Rangan disagreed about the construction of ‘determining’ underscores my own conclusion that the word is capable of bearing both meanings as does the expression ‘remaining on the channel … to receive the activity present’.

223    Embracing either party’s construction does not therefore involve the importation into claim 1 of some feature appearing in the preferred embodiment: cf. Rehm Pty Ltd v Websters Security Systems (International) Pty Ltd (1988) 81 ALR 79 at 89 per Gummow J; Lockwood (No 1) at [69]; Australian Mud Company Pty Ltd v Coretell Pty Ltd [2011] FCAFC 121; 93 IPR 188 at [72] per Bennett, Gilmour and Yates JJ; Fresenius Medical Care Australia Pty Limited v Gambro Pty Limited [2005] FCAFC 220; 67 IPR 230 at [94] per Wilcox, Branson and Bennett JJ. Rather, it involves construing claim 1 in the context of the specification as a whole, including in light of the nature and purpose of the invention disclosed and the CGK in the field.

224    Motorola’s construction is preferable for two reasons. First, it is consistent with the function of the patent whilst Hytera’s is not. Secondly, claim 7 is drafted in a way which assumes that claim 1 does not operate as Hytera submits.

Claim 5

225    Claim 5 is as follows:

5.     The method of any one of the preceding claims wherein the activity is of interest if the control message indicates that the activity is targeted for the subscriber unit.

226    Also relevant for the way in which Motorola initially put its case is claim 6:

6.     The method of claim 5 wherein the second information indicates a characteristic of the activity wherein the characteristic is chosen from the group consisting of identification, voice, data, group, individual, emergency, and non emergency.

227    As the case was opened by both parties, the issue of construction which arose concerned the meaning of the word ‘targeted’. Motorola’s position, based on the evidence of Professor Rangan, was that the word ‘targeted’ was not limited to the use of addressing information. Hytera’s position based on the evidence in chief of Professor Viterbo, was that ‘targeted’ meant targeted to a particular identified subscriber unit.

228    During the course of the trial, the position of Professor Viterbo altered. Under cross-examination he conceded that ‘targeted’ could have the broader meaning contended for by Professor Rangan. In Motorola’s closing written submissions, the evidence about this was extensively set out. In Hytera’s submissions in response, no attempt was made to engage with this evidence. Instead, it was simply said that Professor Viterbo ‘disagreed’ with Professor Rangan’s view without dealing with what had occurred during Professor Viterbo’s cross-examination. Hytera then submitted that the difference between the two professors ‘does not appear to be a critical point of difference’. The same position was taken in Hytera’s oral closing submissions.

229    Where Hytera has not advanced any submission as to why the evidence which appears to suggest that Professor Viterbo had accepted that ‘targeted’ had the broader meaning advanced by Motorola, I see no reason why I should not accept Motorola’s submissions about it. I therefore accept that the position of both Professor Rangan and Professor Viterbo was, by the end of the trial, that ‘targeted’ was not limited to the use of addressing information.

230    That agreement reflects my own view. There are several ways in which activity might be targeted for a particular subscriber unit. It might be because the subscriber unit is programmed to receive a class of activity such as emergency transmissions which does not involve targeting by means of addressing information. Nevertheless, the word ‘targeted’ comfortably covers that situation as a matter of ordinary English. I therefore conclude that ‘targeted’ has the meaning submitted by Motorola. I am fortified in this view by Hytera’s failure to make any substantive submissions about the topic at the end of the trial beyond the formal ones to which I have referred to above.

INVENTIVE STEP

Introduction

231    Hytera’s opening case on obviousness was that the invention disclosed in the claims to the 355 Patent was obvious in light of the CGK and therefore lacked an inventive step. As an alternative case, Hytera submitted that the invention disclosed by the claims was obvious in light of the CGK, together with two other documents it submitted that the skilled person could reasonably be expected to have ascertained, understood, and regarded as relevant under s 7(3) of the Act. These were the Telecommunications Industry Association’s ‘Project 25: FDMA – Common Air Interface’ Standard (‘P25 Standard’), and the ETSI Draft DMR Protocol. It was accepted, by the conclusion of the trial, that these two documents were s 7(3) documents. It is not useful therefore to determine whether they also formed part of the CGK.

232    Hytera’s case on obviousness was based on the evidence of Mr Kuhrt and, as I discuss later, Professor Rangan’s evidence in cross-examination. Mr Kuhrt had been asked to identify what scanning method he would have proposed if asked to develop a conventional digital two-way radio system that improved the amount of time a radio spent scanning channels before July 2004. In his first affidavit, Mr Kuhrt identified such a scanning method. In his second affidavit, he gave further evidence that his method fell within claims 1-6 and 10 of the 355 Patent. He also gave evidence that no ingenuity on his part had been required in formulating his method. Mr Kuhrt’s method was subsequently criticised in certain ways by Professor Rangan. In consequence, Mr Kuhrt clarified and revised his method to address each of Professor Rangan’s concerns. This revised method, he claimed, also fell within the claims of the 355 Patent and similarly involved no ingenuity. Motorola did not submit that Mr Kuhrt’s method lay outside the claims of the 355 Patent. It did however propose its own formulation of what the inventive step of the invention was.

Relevant Principles

233    An invention is taken to involve an inventive step unless it is ‘obvious’ to a person skilled in the relevant art in light of the CGK considered alone (Patents Act 1990 (Cth) s 7(2) (‘Patents Act’)), or together with information in particular documents as defined in s 7(3). The CGK and the s 7(3) documents have a negative aspect to them as well. As the High Court observed in Lockwood Security Products Pty Ltd v Doric Products Pty Ltd (No 2) [2007] HCA 21; 235 CLR 173 at [111] (‘Lockwood (No 2)’):

Practical and technical issues can affect the means by which a concept may be implemented in respect of an already vendible product, and scepticism can inhibit recognition of the utility of applying a concept or idea to a known set of integers. These are matters within the knowledge of relevant witnesses.

234    In its written closing submissions, Motorola emphasised this negative aspect of the CGK as having particular aptness in a field such as wireless communications systems because the standards environment imposed practical and technical constraints on the developments in the relevant technology: at [33]. In Dyson Appliances Ltd v Hoover Ltd [2001] RPC 26 at [156], the English Patents Court recognised the negative aspects of the CGK when discussing how the skilled addressee might have approached the idea of cleaning air in a vacuum cleaner, not by means of bags, but instead by using cyclonic action alone:

In terms of its impact on the issue of obviousness, I believe that this negative thinking which as Mr Kitchin suggested amounted to prejudice, would at least have caused the addressee to regard modification to any of these prior art proposals with considerable reserve if not overt scepticism.

235    As at the priority date, the only TDMA system in existence, as disclosed by the evidence, was the system embodied by TETRA. ETSI was considering introducing a TDMA standard and did so the following year in the form of the 2005 DMR Standard. As at the priority date, it did not exist, although it was in preparation. As I discuss later, a draft of the standard, the Draft DMR Protocol, was available to those in the industry. The point, for relevant purposes, is that as at the priority date, there was no standardised TDMA system although it was apparent that one was soon to be forthcoming. Accepting therefore Motorola’s submission that in a field such as wireless technology the standards environment can impose practical and technical constraints on development, such restrictions in this case are those which can be discerned from 1998 TETRA Standard and the Draft DMR Protocol. As will be seen, Mr Kuhrt’s initial proposed method of scanning would not have been compatible with either of these. When Professor Rangan pointed this out, particularly in relation to the Draft DMR Protocol, Mr Kuhrt revised aspects of his method which to an extent, although not completely, would have brought it within the Draft DMR Protocol. He was explicit in this exercise in doing this only as a response to Professor Rangan’s criticisms.

236    Various expressions have been used to describe what is obvious. It must be ‘very plain’ (Lockwood (No 2) at [51]); it is something that is ‘lying in the way’ (not in the sense of an obstacle but in the sense of something encountered on the path) (Elconnex Pty Ltd v Gerard Industries Pty Ltd (1991) 32 FCR 491 at 507 per Burchett J); ‘you can go straight to it’ (American Cyanamid Company v Berk Pharmaceuticals Limited [1976] RPC 231 at 257); or it is something which ‘would at once occur to anyone acquainted with the subject, and desirous of accomplishing the end’ (Vickers, Sons & Co Ltd v Siddell (1890) 15 AC 496 at 502). Another expression coined by Lockhart J in R D Werner & Co Inc v Bailey Aluminium Products Pty Ltd (1989) 25 FCR 565 at 574 is that there must be ‘some difficulty overcome, some barrier crossed’, an expression noted by the High Court in Lockwood (No 2) at [52], and often referred to in this Court as a convenient metric. Some inventiveness is therefore required although it is also accepted that only a ‘scintilla of invention’ is required under Australian law: Aktiebolaget Hässle v Alphapharm Pty Ltd [2002] HCA 59; 212 CLR 411 at [48] (‘Alphapharm’). This perhaps may be seen as the obverse corollary of the requirement that obvious means ‘very plain’.

237    The question of obviousness is not to be addressed by asking whether each integer or step is obvious. The question is rather whether the combination of integers as a whole is obvious in the requisite sense: Alphapharm at [60]-[72]. As will be seen, this principle has some relevance to the issues which arise.

238    As articulated at [21] of Alphapharm, in considering what is very plain, one is to look forward and to avoid the perils of hindsight:

In those circumstances, the warnings in the authorities against the misuse of hindsight are not to be repeated as but prefatory averments and statements of trite law. The danger of such misuse will be particularly acute where what is claimed is a new and inventive combination for the interaction of integers, some or all of which are known.

239    In this case, as will be seen, Mr Kuhrt was aware of the 2005 DMR Standard which was published in April 2005. As I discuss below, that standard included within it a scan message which used an activity indicator bit and ID information. Although he was asked to formulate his method before being shown the 355 Patent, it must be borne in mind that Mr Kuhrt already knew (and had known for a long time) that the 2005 DMR Standard used an activity indicator bit and identification information. In assessing his proposed revised method, it is to be borne in mind, therefore, that in a sense he had already seen the solution in the 355 Patent because it was the solution in the 2005 DMR Standard. Whilst I do not doubt that Mr Kuhrt genuinely believed that he put himself in the position he would have been in as at July 2004, that is, that he knew nothing except for pre-existing standards (such as the P25 Standard, the 1998 TETRA Standard and the Draft DMR Protocol) at a remove of 14 years, it must be doubted in my view whether it is reasonably possible to put out of one’s mind the existence of the 2005 DMR Standard. I return to this topic below.

240    Whether an invention is obvious is a question to be answered by the Court (AstraZeneca AB v Apotex Pty Ltd [2014] FCAFC 99; 226 FCR 324 at [543] (‘AstraZeneca’)) and is a kind of ‘jury question’: Lockwood (No 2) at [51]. The Court poses the question for itself from the position of a hypothetical construct, the non-inventive skilled person: Wellcome Foundation Ltd v VR Laboratories (Aust) Pty Ltd (1981) 148 CLR 262 at 270-271; AstraZeneca AB v Apotex Pty Ltd [2015] HCA 30; 257 CLR 356 at [18] and [23] per French CJ.

241    It is useful then to begin with the CGK.

The Common General Knowledge

242    I have touched on much which follows in Chapter II and there is, to a degree, some overlap. However, the present discussion is more focussed on the issues relating to the 355 Patent. Much, but not all of it, is uncontroversial. Where there is a controversy, I explain it.

243    There are two categories of two-way radio systems: conventional and trunked. In conventional systems, users monitor traffic channels (i.e. channels that facilitate transmissions between users) to select one for transmission purposes. In trunked systems, users monitor control channels which then assign them to traffic channels for transmission purposes. Mobile stations in two-way radio systems have been able automatically to scan frequencies for transmissions since the 1980s.

244    In conventional two-way radio systems, mobile stations scan traffic channels. Mobile stations are pre-programmed with a list of channels for scanning purposes. When scanning, a mobile station locks onto channels in this list to locate active transmissions. While scanning, if a mobile station determines that a transmission is, for example, a valid voice transmission, it will stop scanning and render the transmission to the mobile station’s speaker.

245    FDMA separates channels by frequency. For example, FDMA could be implemented to facilitate multiple access by splitting a 12.5 kHz frequency into two 6.25 kHz frequencies that form separate channels. FDMA was introduced as a multiple access method to two-way radios in the 1990s. In FDMA systems, a transmission occupies the whole channel. APCO P25 is an example of a two-way radio system that was developed in the 1990s that implements FDMA as the multiple access method.

246    On the other hand, TDMA separates channels into timeslots while preserving the channel bandwidth. For example, a 12.5 kHz frequency may be split into two timeslots, referred to as ‘logical channels’, and a transmission occupies one timeslot on the frequency. TDMA was introduced as a multiple access method to two-way radios in the 1990s. TETRA is an example of a two-way radio system that implements TDMA as the multiple access method. The distinction between FDMA and TDMA systems may be understood diagrammatically in this way:

247    As at July 2004, the standardised two-way radio systems that were known to persons working in the field of two-way radios in Australia included the TETRA, P25 and MPT1327 systems. TETRA implemented TDMA as the multiple access method. The 2005 DMR Standard, which became a standardised TDMA two-way radio system, was known to be in its draft stage.

248    Two-way radio systems utilise control messaging for scanning purposes. The use of control messages allows scanning mobile stations to determine information about the transmission taking place on a channel. Analogue two-way radios implement frequency tones as a form of control message for scanning purposes. Analogue mobile stations often included in their memory a list of frequency tones that were associated with, for example, a talkgroup. When the frequency tone is detected during scanning, the station would stay on that relevant channel emitting that tone.

249    Digital two-way radio systems implement control messages in the form of embedded signalling within a data stream for scanning purposes. These messages may be contained within the transmission itself (conventional systems) or separately transmitted on a control channel (trunked systems). In digital systems, control messages are used to provide information about transmissions on a traffic channel.

250    MPT1327 two-way radio systems utilise digital GTCM as a form of control messaging for scanning purposes. The GTCM is transmitted by a repeater on the control channel to broadcast control information to connected terminals about transmissions on traffic channels. Similarly, TETRA two-way radio systems also utilise digital control messages that are transmitted on a dedicated control channel to broadcast information about transmissions on traffic channels. However, unlike MPT1327, because TETRA implements TDMA, a single repeater can be used for both control slots and multiple talk slots. APCO P25 two-way radio transmissions include LC messaging that forms part of a digital voice transmission to provide signalling information to scanning mobile stations in a conventional (non-trunked) system.

251    The control messages used for scanning purposes in MPT1327, TETRA and APCO P25 systems included addressing information such as TGID and/or SUID information. The inclusion of addressing information allows for a scanning mobile station to determine if it is an intended recipient of an active transmission by comparing the addressing information in the control message with addressing information stored in its memory.

Control Information and Activity Indicators

252    Control messages used in FDMA two-way radio systems do not require signalling information that indicate timeslot activity since timeslots are not used in FDMA systems. Hytera submitted that TDMA systems require control information indicating timeslot activity because one frequency can carry several concurrent transmissions on different timeslots. It submitted that it was within the CGK that control information was generally sent in control messages which could be split over multiple bursts to reduce the amount of overhead used in a single burst (i.e. in a 30 msec burst, the more of the burst that is devoted to the transmission of control information, the less of it that is available for the delivery of the substantive payload). The evidence about this needs to be attended to with some care. Hytera relied on three items of evidence to make good its submission.

253    The first was §39 of Professor Rangan’s first affidavit where he said:

This control information may include signalling information about each timeslot on each channel, such as whether the channel is presently supporting a call or transmission on each timeslot, for example as described on page 6, lines 28 to 30 of the AU 355 patent.

254    Later at §41, Professor Rangan also said that his explanation of the 355 Patent, including at §39, reflected his understanding as at July 2004. I therefore accept that it was part of the CGK in July 2004 that control information could be used in TDMA systems to indicate whether there was activity on a channel. It is important to be clear, however, that this did not involve a recognition that control information could be used to signal information about timeslot activity as part of a scanning methodology.

255    The second arose from the cross-examination of Professor Rangan. At T800.11, he was cross-examined to suggest that the CGK prior art systems did indicate information as to whether activity is present or not on each timeslot:

MR BURGESS: Let’s take a moment back. What I was putting to you originally – go back a couple of steps. The first proposition we discussed was that it was part of your background knowledge in July 2004 that the control information in a TDMA system included signalling information about each timeslot on the channel such as whether the channel is presently supporting a call or transmission on each timeslot.

PROF RANGAN: Yes. I think that – yes. Prior art systems did indicate information as to whether activity is present or not on each timeslot.

256    Two things should be noted about this. First, the cross-examination was directed to eliciting an answer about information indicating timeslot activity rather than the use of an activity bit. As I have previously mentioned, whilst the illustrative embodiment for the 355 Patent used a 28 bit CACH message which contained an activity indicator bit for each timeslot (the A bits), the claims of the patent are not expressed in terms of an ‘activity indicator’ but rather, in terms of a ‘first information’. On the other hand, it is clear that Professor Rangan’s evidence was directed to information which indicated activity.

257    Secondly, the cross-examination did not linger on which prior art systems included information indicating whether activity was present on each timeslot. An untutored reading suggests that the Draft DMR Protocol included an activity indicator bit. For example, section 5.5 contemplated a 24 bit CACH message which included an activity bit:

The CACH exists on the outbound channel only. This field provides framing and access information for the bursts as well as low-speed data. A subscriber unit that decodes the CACH can be assured that it has received an outbound transmission from a repeater or an RFSS. This channel is not tied channel l or 2 but is common between them.

Of the 24 bits present in each CACH burst, 4 are dedicated to framing and indicators, leaving 20 bits for payload and FEC.

…

AT (Access Type) – Indicate whether the next inbound slot is busy or idle.

0 = idle on the inbound channel

1 = busy on the inbound channel

TC (TDMA Channel) – Indicates whether the next inbound and outbound burst is channel 1 or channel 2.

0 = following outbound Burst is TDMA channel 1

1 = following outbound Burst is TDMA channel 2

…

258    It will be seen that the Access Type (‘AT’) bit is an indicator of whether the next timeslot is active or idle. However, as Motorola pointed out, at [62] of its written opening submissions, the Draft DMR Protocol did not concern itself with a scanning methodology. Thus, whilst I am willing to accept Professor Rangan’s evidence that the prior art did include the use of control information which indicated whether there was activity on a timeslot, his evidence did not go so far as to suggest that it did so as part of a scanning method.

259    The only prior art otherwise referred to was the P25 Standard. I was not taken to any part of this to reveal the use of control information to indicate activity on a timeslot as part of a scanning method.

260    Hytera also relied on §57 of Professor Rangan’s third affidavit. There it was said:

In addition, because the P25 Standard is describing an FDMA system, this document does not describe a system in which a channel (i.e. RF frequency with additional qualifying information) is divided into timeslots. This is a significant distinction because in a TDMA system (as in the method of scanning described in the Relevant AU 355 Claims) any method of scanning must be capable of checking activity on multiple timeslots on each radio frequency. By contrast, a method of scanning in an FDMA system, which only has one user allocated to a given radio frequency, does not need to be able to check activity on multiple timeslots on each radio frequency. It follows that substantial changes would be required before implementing any method of scanning in a TDMA system based on the requirements of the FDMA system described in the P25 Standard, in order to enable a subscriber unit to check activity on multiple timeslots on each radio frequency.

(emphasis added)

261    Again, I do not think this reveals the use of control information to indicate activity on a timeslot as part of a scanning method.

262    Into this picture must then be introduced the evidence of Mr Kuhrt under cross-examination at T776.41-777.30:

MR MOORE: Yes. And so you will agree that at the time you came to do your hypothetical task, you were familiar with the short LC message in the 2005 standard.

MR KUHRT: Yes. I don’t remember specifically of - - -

MR MOORE: Yes.

MR KUHRT: But it doesn’t really matter. I – I could have read it. Yes.

MR MOORE: Yes. And including – you were familiar with the use of an activity bit as referred to in the standard.

MR KUHRT: Yes.

MR MOORE: Yes. And you would agree, wouldn’t you, that the prior art prior to July 2004 had not used an activity bit as such?

MR KUHRT: Not that I was aware of.

MR MOORE: Yes. Now - - -

MR KUHRT: But I would like to say - - -

MR MOORE: Yes. Yes.

MR KUHRT: The bits are used as, you know, there’s things called flags in the software which are used to indicate all sorts of things.

MR MOORE: Yes.

MR KUHRT: So it’s – it’s common to use a flag or a bit to indicate different states of – of events.

MR MOORE: Yes. But being specific to the issue here, that use of a bit, a one-bit, to indicate activity or no activity had not been used in the prior art - - -

MR KUHRT: Not that I was aware of.

263    One therefore has this situation: Hytera sought to make good its case on this point based on the evidence of Motorola’s expert, Professor Rangan, whilst Motorola sought to make good its case based on the evidence of Hytera’s expert, Mr Kuhrt. Professor Rangan said that the prior art did indicate the use of information to indicate whether activity was present on a timeslot (T800.11) but Mr Kuhrt thought that nothing in the prior art had used a single bit to indicate timeslot activity: T777.27-30. It is not clear to me that Mr Kuhrt was speaking of the use of control information to indicate activity on a timeslot as part of a scanning method. Since the Draft DMR Protocol does include the use of control information in which a bit is used (outside a scanning method) to indicate timeslot activity, I am inclined to understand Mr Kuhrt’s answer as a statement that the prior art did not indicate a method of scanning in which an activity bit was used as part of a scanning methodology. Mr Kuhrt was aware of the Draft DMR Protocol and to read his evidence otherwise would involve attributing to him an ignorance of that document which I am satisfied he did not have.

264    At a factual level, I therefore find that:

(a)    there was no prior art scanning method which included the use of an activity indicating first information as part of a control message; and

(b)    the prior art did include the use of information in a control message to indicate whether there was activity on a timeslot. In the Draft DMR Protocol, this took the form of an activity bit. However, this use of activity indicating first information did not form part of a scanning method.

Scan Speeds

265    An issue with two-way radio systems as at July 2004 was that existing scan speeds presented a short delay for users. The scan speed issue was a known issue for analogue two-way radio systems and continued to be a known issue for conventional digital two-way radio systems such as APCO P25. In APCO P25 conventional two-way radio systems, the full LC message (i.e. the control message that provided addressing information for scanning purposes) was split over several bursts and could not be decoded immediately. This meant that mobile stations had to wait for the relevant information to be received and decoded before the mobile station was able to make a decision with respect to remaining on the channel.

266    As at July 2004, reducing scan time was generally considered desirable although the delay it engendered for users was only very short. It was a relatively low priority issue in July 2004.

The P25 Standard

267    Although Hytera contended that the P25 Standard was part of the CGK or was s 7(3) information, in its closing submissions it did not develop any submission in relation to obviousness based upon the P25 Standard. While I accept that the standard is s 7(3) information, its significance would appear only to be that it involved the use of an LC message.

The Draft DMR Protocol

268    As I mentioned earlier, the Draft DMR Protocol was discussed during a working group meeting at ETSI during the development of the 2005 DMR Standard. This was the unchallenged evidence of Mr Seedle who also explained that no one who was present at the meeting would have regarded the document as confidential. Mr Seedle also indicated that the document was thereafter shared and discussed in the industry. It is not surprising therefore that both Mr Kuhrt and Professor Rangan thought that the Draft DMR Protocol was a prior work which would have been located and read by a skilled addressee in order to understand what had already been developed in the field of two-way radios. Because it is a draft, it could not be regarded as part of the CGK, but given this agreement, it is plain that it is s 7(3) information.

269    In the manner in which Hytera pursued its case on obviousness in its closing submissions, the relevance of the Draft DMR Protocol arose from section 10 at page 63. This was in these terms:

10 LC Words

Two example LC words are shown in Figure 10-1. Actual LC words will vary with circumstance and application.

MFID (Manufacturers ID) – This is asserted when non-standard features are included in the voice message by the manufacturer

E – Emergency indicator.

Source ID – This identifies the transmitting subscriber unit

Destination ID – This identifies the receiving subscriber unit in cases where the destination is a single subscriber.

TG1D (Talkgroup ID) – This identifies the talk-group for the message in cases where the transmission is addressed to a group.

270    The example LC words are both 72 bits in length. Professor Rangan thought that a person of ordinary skill would have considered using the LC word discussed here for scanning purposes: T822.3-7. However, he did not think that it met the requirements of claim 1 since it did not have a ‘first information’, that is to say, it did not include an activity indicator: Joint Experts Report at Q11(c) (‘JER’). Professor Rangan was cross-examined about this and he accepted, at T823.36-824.47, that the LC word in the Draft DMR Protocol had all of the features of claim 1 apart from the first information.

Outline of Debate

271    Hytera’s case on obviousness had two main limbs. In the first limb, Hytera submitted, as I have found, that it was part of the CGK that in TDMA systems, control information was sent to identify whether a physical channel was presently supporting a call or transmission on each timeslot. Hytera characterised this kind of control information as the ‘first information’ referred to in claim 1. Hytera submitted that it was CGK at the priority date that scanning messages could include identification information. Hytera submitted that this kind of information was the second and third information referred to in claim 1. Consequently, the invention disclosed in claim 1 was an obvious combination of two elements which already existed in the CGK: the first information was just an example of the use of information to identify activity on a channel; the second information was the kind of information found in LC messages such as those used in the P25 Standard. To make good this point, Hytera relied on the evidence of Mr Kuhrt.

272    In the second limb, Hytera submitted that the LC word disclosed in the Draft DMR Protocol had all of the integers in claim 1 apart from the first information. However, given that it was CGK that TDMA systems used control information which identified whether a physical channel was presently supporting a call or transmission on a timeslot, it followed that the first information in claim 1 was part of the CGK. Consequently, the invention disclosed in claim 1 was an obvious combination of these two matters such that the 355 Patent lacked an inventive step. To make good this point, Hytera relied on the evidence of Professor Rangan.

273    Motorola’s response to this case was threefold. First, it denied that the combination of the first information with the second information in claim 1 was obvious and therefore not inventive and submitted that Mr Kuhrt’s evidence that it was obvious ought not to be accepted. Secondly, it denied that the combination of the LC word in the Draft DMR Protocol combined with the first information, which was CGK, meant that the invention was obvious. It submitted that Professor Rangan’s evidence did not establish to the contrary. Thirdly, it advanced its own identification of the inventive step. Turning then to the detail:

Professor Rangan and Mr Kuhrt

274    Although submissions were advanced that Mr Kuhrt had more specialised expertise than Professor Rangan in the field of two-way radio communications, I did not regard this as a material consideration.

Mr Kuhrt’s First Method

275    At §211 of his first affidavit, Mr Kuhrt explained that he had been asked by Hytera’s instructing solicitors to explain what, if any, scanning method he would have proposed if, at 26 July 2004, he had been asked to develop a conventional two-way radio system that improved the amount of time a radio spends scanning channels. At this time, Mr Kuhrt had not been provided with the 355 Patent. He gave evidence that in responding to this request, he took into account only information of which he was aware and which he regarded to be well-known and generally accepted in Australia in the field of two-way radio communications as at 26 July 2004.

276    In Mr Kuhrt’s initial method, a repeater would regularly transmit a message (or burst) on the downlink frequency which would be received by the mobile station. The burst would contain a synchronisation pattern that enabled the mobile station to synchronise to the transmission. The synchronisation pattern would be present in the middle or at the beginning of each timeslot (or data frame) that was transmitted from the repeater to the mobile station: Kuhrt-1 at §213.

277    Mr Kuhrt would then carve out a portion of the payload in the latter half of the same burst and insert a scan message. The scan message would consist of:

(a)    information that distinguished between an idle frequency and an active frequency such as a data bit which indicated if the frequency was currently being used for a transmission or was idle;

(b)    identification information such as data bits that indicated the transmission source identification details and/or the talkgroup identification details;

(c)    information that provided encryption information if required; and

(d)    in a TDMA system, the design would also include information that indicates which timeslots on the frequency were active.

278    Mr Kuhrt thought that the scan message would speed up the automatic scanning process because it would provide the mobile station with all of the necessary information in a single burst. By doing so, the mobile station would not need to decode other bursts in the data stream to determine if it should remain on the frequency. The addition of a complete scan message, as part of every frame, would remove the need for mobile stations to wait on a frequency to receive additional bursts. The method would therefore be faster than a system which required the decoding of multiple messages in order to determine whether to remain on the frequency.

279    Mr Kuhrt would have located the scan message after the synchronisation pattern. Doing so would have permitted for both synchronisation and interrogation of the transmission to determine if it was valid within the same timeslot. As a result, after a mobile station received the synchronisation message, it would then be able almost immediately to locate and process the scan message. This would improve the amount of time that it took to scan frequencies automatically because it would avoid a scenario in which synchronisation occurred in one burst and where the mobile station would then have to wait for another burst to receive the scan message. Mr Kuhrt illustrated his method this way:

280    Mr Kuhrt thought this design was a ‘simple solution’ (at §222) to improve the speed and efficiency of automatic scanning. At the priority date, he would have expected that both he, and other engineers working in the field of two-way radios, could easily have implemented the method using routine software coding as only minimal software changes would be required. In his second affidavit, Mr Kuhrt said that his design had all of the features of claims 1 to 6 and 10 of the 355 Patent: Kuhrt-2 at §73. In Kuhrt-2 at §138ff, he explained that he did not think that claims 1 to 6 and 10 of the 355 Patent involved any ingenuity. In his view, it was well-known and accepted in the field as at 26 July 2004 that:

(a)    control messages were used in automated scanning to enable mobile stations to make determinations about whether channels contained active transmissions of interest to the terminal. He instanced the MPT1327 and APCO P25 systems as examples where this was the case (Kuhrt-2 at §§140-141); and

(b)    control messages could be used to inform a terminal whether there was activity on the channel: Kuhrt-2 at §146.

Professor Rangan’s Criticisms of Mr Kuhrt’s First Design and Mr Kuhrt’s Response

281    In his third affidavit, Professor Rangan expressed his view that he would not have proposed Mr Kuhrt’s design as a solution to the task set for him by Hytera’s instructing solicitors. That is to say, he did not consider Mr Kuhrt’s design to be a ‘desirable or viable solution’: Rangan-3 at §§87-91. Professor Rangan had four substantial criticisms of the method.

Overhead

282    Professor Rangan thought that the method would result in a large amount of overhead being included in each burst. In particular, he felt that because the scan message included the identification information for the transmission source and the talkgroup or destination, this would require a large number of data bits to be encoded in each burst, which would comprise a large portion of each burst. He explained, as an example, the consequences of the method under the Draft DMR Protocol. In that protocol, the LC message contained data that uniquely identified the transmission source and talkgroup or destination. It was 128 bits in length in which 56 bits were for error correction. He observed that this would be approximately 50% of the payload size in a TDMA burst under the Draft DMR Protocol which was 216 bits. Indeed, to avoid such a large consumption of the payload, the Draft DMR Protocol described transmitting the full LC message over seven bursts. Splitting it up in this way reduced the amount of payload which had to be sacrificed to control data in each burst. Professor Rangan thought, in consequence, that Mr Kuhrt’s method was not viable and that an improvement in scanning speed that came at the expense of payload would be a distinct disincentive to developing a new scanning mechanism.

283    Mr Kuhrt did not accept this criticism. He had three points. First, he began by observing that in his method he had not provided any details about the size of the payload or control messages. Since the Draft DMR Protocol was just a draft at this point, I incline to the view that Mr Kuhrt cannot, in principle, be criticised for not including such details since, at this point, there was, as yet, no standard. On the other hand, since it was known that the 2005 DMR Standard was in the pipeline, there may be a certain degree of unreality in formulating a scan method which would have been incompatible with the draft. I return to this issue later.

284    Secondly, Mr Kuhrt noted that Professor Rangan had assumed that his control message was the same in length as the full LC message in the Draft DMR Protocol (i.e. 128 bits). In his first affidavit describing his method, Mr Kuhrt had not specified what was in his control message other than in general terms (i.e. an activity indicator and identification information). He now explained in his third affidavit that his scan message would use 20 bits: Kuhrt-3 at §84. It was as follows:

285    This message included a single bit to identify timeslot activity (‘TSA’), a single bit to identify if the next timeslot was active (‘NSA’), a single bit that identified whether the payload was encrypted (‘ENC’), 9 bits that are used to provide address information (‘ADR’), and 8 bits of error correction (‘CRC’). The TSA and NSA bits provided information which distinguished between idle and active frequencies. In relation to the 9 bits allocated to identification information, the Draft DMR Protocol, it will be recalled, provided 24 bits for the destination ID and 24 bits for the source ID for a total of 48 bits (for a unit to unit call), and 16 bits for TGID information where a group call was involved. Mr Kuhrt’s control message is therefore quite a bit smaller than what, at that time, was to be found in the Draft DMR Protocol.

286    However, as Mr Kuhrt explained, 9 bits still provided for 512 unique identifiers or combination of bits (29=512). From this 512, he deducted one to be reserved for a broadcast function. Splitting the 511 remaining identifiers up, Mr Kuhrt reasoned that, for example, this could be configured for 31 talkgroups and 480 individual terminals (31+480=511). Mr Kuhrt noted that as at 26 July 2004, for a small to medium sized fleet with which he was familiar, the largest number of talkgroups was about 15 and the largest number of subscriber units was around 150. He did not say this but I infer from this evidence that a 9 bit ID field may not have been sufficient for a large fleet. However, that it could not be used in a large fleet does not deny that it could be used in a small or medium sized fleet. The existence of this possibility is relevant to assessing, in due course, Motorola’s criticism that Mr Kuhrt’s solution was not practical.

287    Thirdly, with Mr Kuhrt’s revised 20 bit scanning message now in play, he did not think that deducting 20 bits from the payload in the Draft DMR Protocol was unacceptable. He noted that the control information for the Draft DMR Protocol was 72 bits. Using his 20 bit scanning message, this left 52 bits available for the remainder of the control information without in any way impinging on the payload. However, the Draft DMR Protocol also provided for there to be a synchronisation pattern of 48 bits within the control information. Mr Kuhrt now suggested that it was not necessary to use a synchronisation pattern of that size and that a 28 bit synchronisation pattern would suffice. His control message therefore consisted of 20 bits of scanning information and a 28 bit synchronisation pattern for a total of 48 bits. Even under the Draft DMR Protocol, this left 24 bits left over to be used for other purposes.

Distinguishing Idle from Active Frequencies

288    It will be recalled that Mr Kuhrt’s initial method included information which indicated whether the frequency (separate from the timeslot) was active. Professor Rangan took issue with the point of this. His point was that since the scan message included identification information, the entire message had to be decoded, and there was therefore no point in including such an indicator: Rangan-3 at §88(b). Using the identification information, the terminal would either conclude that there was an identification match, in which case it was obvious that the frequency was active, or it would not, in which case it would not matter.

289    In response, Mr Kuhrt explained that he had included the activity information ‘to allow scanning mobile stations to quickly determine if a frequency is active without having to consider the addressing information’: Kuhrt-3 at §98. This is an example of a negative criterion in operation – the time saving comes from the fact that once it is determined there is no activity there is no need to process the identification information. There is ambiguity in Mr Kuhrt’s evidence about the difference between an indicator of activity on a frequency, and activity on one of the timeslots. However, neither Mr Kuhrt nor Professor Rangan appeared to be concerned about this at this stage and I will disregard it. In any event, in Mr Kuhrt’s revised method, his 20 bit scan message (see above at [284]) does not include a bit to indicate activity on the frequency but only a bit to indicate activity on the timeslot i.e. the TSA. This issue appears, therefore, no longer to matter in relation to Mr Kuhrt’s revised method.

Timeslot Activity Indicator

290    Professor Rangan made the same criticism of the use of an activity indicator for the timeslots. Mr Kuhrt’s response was the same. I accept Mr Kuhrt’s evidence. Once the 20 bit scan message has been received, processing time can be saved if the first bit indicates there is no activity on the timeslot because there will be no need to compare the ID information bits. There was some evidence in relation to the addition of an activity bit to the full LC word which I discuss below at [317]. Both Professor Rangan and Mr Kuhrt thought that it would not have been logical to have added an activity bit to the full LC message because the saving in processing time would have been outweighed by the overhead costs of receiving and decoding the additional bit. I have considered whether this evidence may be applied to this situation. Whilst I suspect that it may, the question is not quite the same and I do not think I can conclude on the balance of probabilities that it does.

Routine Software Changes

291    It will be recalled that Mr Kuhrt thought that this method could be easily implemented using ‘very minimal software changes’. Professor Rangan disagreed. He thought it would have been desirable to implement the method in a way which was compatible with existing software ‘which would have been developed to meet the requirements of previous systems or standards’: Rangan-3 at §90. This would ensure that devices adopting the method remained interoperable with devices which used existing scanning technologies. Doing so might entail significant software changes and would require testing and troubleshooting. This was particularly so because the method proposed sending scan messages by carving out a portion of the payload which was quite different to the way in which the control messages had been transmitted prior to July 2004.

292    There is a degree of unreality about the position of both Mr Kuhrt and Professor Rangan on this aspect. As at the priority date, the only system using TDMA was TETRA and there was no ETSI standardised TDMA technology. Although an ETSI standard was in the offing at this stage, it found expression only in the Draft DMR Protocol which was, in truth, a draft. I would accept that Mr Kuhrt’s method would be radically inconsistent with the Draft DMR Protocol. The idea of using a single burst of control information following the synchronisation pattern would have been impossible to make work with any system which was using the kind of system described in the Draft DMR Protocol.

293    It is also clear that Mr Kuhrt’s solution is quite incompatible with the 1998 TETRA Standard if only because TETRA implemented a control channel. It will be recalled that TETRA split a 25 kHz frame into four timeslots. One multi-frame was comprised of 18 such frames, one of which was devoted to a control channel.

294    Part of the problem is that the argument that Mr Kuhrt and Professor Rangan have on this issue takes as its point of departure some form of software, not identified by either. Working out whether the software changes, which would need to be made to this unidentified software, would be significant (as Professor Rangan thought) or routine and straightforward (as Mr Kuhrt thought) is therefore a potentially meaningless enquiry. If the starting point is the 1998 TETRA Standard or the DMR Draft Protocol, then I accept Professor Rangan’s evidence and, indeed, might go further and express some scepticism that Mr Kuhrt’s method could ever be integrated into the then existing systems which had a radically different approach to control messages. I accept Professor Rangan’s evidence that this might, at least in theory, be surmounted. However, I correspondingly accept his point that this would be a significant software undertaking as it would involve fitting into one system, two quite different approaches to control information.

295    On the other hand, if the starting point is that there is no pre-existing system and that the writing of the software takes place on a blank canvas, then I accept Mr Kuhrt’s point that this would not have been especially difficult since the interoperability issues referred to by Professor Rangan would not arise.

Conclusions on Mr Kuhrt’s Revised Methodology

296    I conclude that Mr Kuhrt’s revised methodology would have provided an improvement in scanning time which could have been used as a system suitable for small or medium size fleets. It would not have been suitable for large fleets. It is evident that the system would have included less forward error correction and smaller synchronisation patterns. Although Mr Kuhrt’s initial method would have compromised call quality by reducing the payload, his revised methodology does not suffer from this vice. I am unable to assess the impact of the decreased forward error correction and synchronisation patterns on the utility of Mr Kuhrt’s method. It was evident that Professor Rangan looked askance at this approach. But I am unable to find that Mr Kuhrt’s revised method was unworkable for these reasons. There was no explicit evidence about the practical effect that these economies would have had on the operability of any such system. I accept that Mr Kuhrt’s revised methodology falls within the claims of the 355 Patent (which was not disputed) and that the patent makes no stipulations about control message size, the size of synchronisation patterns, or the extent of forward error correction.

297    That said, having regard to the direction in which the Draft DMR Protocol was heading, Mr Kuhrt’s revised methodology strikes me as being a very unlikely solution as at July 2004. To solve the relatively lesser problem of scan time by coming up with a methodology with diminished forward error correction and reduced synchronisation patterns (which was radically inconsistent with the direction in which the industry appeared to be heading) was possible, but it was most unlikely that anyone would have actually embarked on the search for such a method. Mr Kuhrt accepted that if he had been developing a new device at the priority date, he would have obtained the Draft DMR Protocol because it would have been instructive to him as to what was likely to become standardised in the future:

MR MOORE: Yes. And if you working in Australia were interested in developing some new device at that time, presumably, you would have obtained this standard because it would have been instructive to you as to what was likely to become standardised in the very near future?

MR KUHRT: Yes.

MR MOORE: And you would be very interested in what’s the technology being employed and how is that going to operate, and you would start thinking along those lines if you were going to be involved in any development task at that time?

MR KUHRT: Yes.

MR MOORE: Yes. And you mention in your opening paragraph there, there was little scope within the specifications to improve scan time. What you meant by that is that if you have a different mode of scanning it’s not going to be consistent with the scan mode in the specification?

MR KUHRT: Yes, if there was something that you’re proposing that would be outside what was planned in the specification. Yes.

MR MOORE: Yes. And you wouldn’t have been engaged in any task of departing from the specification in that way; correct?

MR KUHRT: Correct.

298    In my view, the problem of scan time was not a major issue and not one which the skilled addressee would have regarded as justifying such an approach to forward error correction and synchronisation patterns.

Motorola’s Submissions

299    First, Motorola emphasised that in a field such as two-way radio communications, it was a mistake to focus solely on a single problem such as improving scan speed: MCS(P) ch 2A at [80]. Every problem in the field had impacts on other problems. To take a neutral example, one could improve voice quality by enlarging the size of the payload in each burst but this would come at the expense of trimming the control information (or, more likely, slowing its delivery down by spreading it over a large number of bursts). One could increase the speed of decoding control messages by increasing the size of the control information, and thereby decreasing the number of bursts required for such information to be transmitted, but this would come at some cost to something else, for example, the size of payload. Within the control information, one could increase the size of the identification information but there is no such thing as a free lunch, and this would need to be made up somewhere else, for example, by making economies with the extent of forward error correction or the size of the synchronisation patterns.

300    Motorola denied, therefore, the legitimacy of the task which had been given to Mr Kuhrt. There was, on this view, no such thing as setting out to improve scan time as a technical task pursued in isolation. Any solution to the problem of improving scan time necessarily had to exist in a broader context of other technical constraints. By way of analogy, imperfect perhaps, it would be artificial to set the skilled addressee the task of designing the optimally safe motor vehicle without taking account of the real world facts that motor vehicles have to meet other problems too, such as fuel efficiency and cost. It might be obvious that constructing the motor vehicle out of titanium alloy would achieve this outcome, but it could not be ignored that no person designing a motor vehicle would do so given the weight and cost of the titanium solution.

301    Secondly, Motorola submitted that it was important to be alert to the perils of hindsight reasoning: MCS(P) ch 2A at [82]. Given that an activity indicator bit was present in the 2005 DMR Standard as part of a scan method of which Mr Kuhrt was aware, this was apt to have suggested to him, subconsciously, the idea of using such a bit in his methodology. At the very least, one needed to approach his evidence with some care given that context. Whilst Mr Kuhrt had said that he had only used what he knew at the priority date, the mental task of divesting oneself of certain knowledge in a question to identify the obvious was far from straightforward. I accept this submission so far as it goes. I do not think it proves necessarily that Mr Kuhrt’s evidence about obviousness is to be rejected outright but it does require some circumspection in its assessment.

302    Motorola next submitted that Mr Kuhrt’s revised method did not assist Hytera on its case on obviousness: MCS(P) ch 2A at [91]-[98]. It made five criticisms: first, the task which had been set for Mr Kuhrt was not a task that would have been attempted in the real world. The issue of scan time would never have been implemented in isolation but, for the skilled addressee, would only have arisen in the broader context of designing an entire two-way TDMA system. In such a context, the question posed for Mr Kuhrt would never have actually been posed.

303    Secondly, in any event, Mr Kuhrt’s revised method involved reductions in the size of the ID information message to 9 bits (which meant it could not be used for large fleets), a reduction in forward error correction and a reduction in the size of the synchronisation patterns. Although I have not found it possible to gauge what degradation the last two matters would have had upon a system using Mr Kuhrt’s revised method, I do accept that it is inevitable that they would have had some deleterious impact. No comment needs to be made in relation to Motorola’s submission that Mr Kuhrt’s first method reduced audio quality since his revised method did not lead to a reduction in the size of payload.

304    Thirdly, Motorola submitted that Mr Kuhrt’s revised method was not obvious because it had not occurred to Mr Kuhrt at all. What had occurred to Mr Kuhrt was his initial method and it was only once Professor Rangan pointed out the difficulties which it entailed that Mr Kuhrt had formulated his revised method. Thus, the revised method was the result of him having been asked a highly artificial question by Hytera’s instructing solicitors and having been prompted by Professor Rangan’s criticism further to refine what he had done. As such, it did not reflect what a skilled addressee would have done at the priority date.

305    Fourthly, as I have already noted, Motorola pointed out that Mr Kuhrt’s revised method used an activity indicator bit. This had been present in the 2005 DMR Standard, but not in the prior art as at July 2004. Mr Kuhrt accepted that he was aware of the 2005 DMR Standard: T777.3-6. Motorola therefore submitted that the clean slate approach Mr Kuhrt had endeavoured to take in relation to the formulation of his method (and then his revised method) was incurably affected by hindsight.

306    Fifthly, Mr Kuhrt was also aware, as a result of his familiarity with the 2005 DMR Standard, of the use of the shorter LC message. I accept, as Motorola submitted, that the shorter LC message in the 2005 DMR Standard is essentially the same as the 28 bit activity update message disclosed in the illustrative embodiment in the 355 Patent. Motorola submitted that it was therefore impossible to disentangle Mr Kuhrt’s revised method from his knowledge of the use of a shorter LC message. I do not think that Mr Kuhrt’s revised methodology was affected by hindsight in this regard. The one thing Mr Kuhrt’s revised method does not use is a shorter LC message of the kind in the 2005 DMR Standard. To the contrary, its control message is effectively a full LC message.

Hytera’s Submissions

307    In its opening written submissions, Hytera had placed emphasis upon Mr Kuhrt’s revised method to show that the claims of the 355 Patent were obvious in light of the CGK alone. It also advanced a submission that it was obvious in light of the P25 Standard and the Draft DMR Protocol. By the close of the trial, however, the role of Mr Kuhrt’s revised method had retreated in prominence. Hytera did not, however, abandon its reliance on Mr Kuhrt’s evidence.

308    The first point made by Hytera in its closing submissions was that what was required to be inventive was the invention as claimed. It was not enough that the illustrative embodiment disclosed in the body of the specification contained an inventive step if the claims themselves did not disclose that inventive step. Whilst I accept that: (a) the invention is defined by the claims which must be interpreted in light of the specification and the CGK; and (b) that the invention must involve an inventive step, I do not accept that it follows that the inventive step must itself be specified in the claims (if that is what Hytera intended). On the other hand, I do accept that the question is whether a method of scanning using a combination of a first and second information etc. is the invention whose inventiveness must be assessed. The question is not whether the use of the 28 bit CACH message described in the specification is inventive.

309    Hytera next submitted that the evidence showed that it was part of the CGK that control information was used in TDMA systems (HCS(P) ch 3 at [87]) to identify whether a physical channel (i.e. a frequency) was supporting a communication. It referred to Professor Rangan’s evidence at T800.11-12 which I have referred to above. I accept that Professor Rangan’s evidence does establish that the CGK included the use of control information to indicate activity on a timeslot. However, it does not establish, for the reasons I have given, the use of this control information as part of a method of scanning.

310    However, Hytera also submitted that Professor Rangan had accepted that if he had been designing a scan method before July 2004, he would have considered using the control information to indicate whether the timeslot was active or not:

MR BURGESS: And so for the reasons we just discussed, the detection of the carrier presence alone will not inform the scanning mobile station whether a given timeslot is busy or idle; correct?

PROF RANGAN: That’s right. In general, it would not.

MR BURGESS: Yes. Therefore, if you had designed a system to automatically scan at least the physical channels in a TDMA system before July 2004 you would have used control information to inform the scanning mobile station whether each timeslot was active or idle when a carrier was detected; correct?

PROF RANGAN: That – that seems logical, yes.

311    I take this to be evidence that the inclusion of activity indicating information in a control message as part of a scanning method, is something which would have occurred to Professor Rangan as at the priority date. Whilst the prior art indicated that such control information had been used, it had not been used as part of a scanning method. However, Professor Rangan’s evidence bears out Hytera’s contention that the use of such information as part of a scanning method was obvious. Certainly, it was obvious to Professor Rangan.

312    Hytera also submitted that the use of addressing information as part of a scanning method was obvious in light of the CGK. Here, Hytera relied upon the Draft DMR Protocol’s use of the LC message. It submitted that it had all the features of claim 1 apart from the ‘first information’. I accept these submissions. Professor Rangan thought that the person of ordinary skill would have thought of using this message for scanning: JER at Q11(c). Further, he accepted under cross-examination that the LC message in the Draft DMR Protocol had all of the features of claim 1 of the 355 Patent apart from the first information:

MR BURGESS: And you say there:

However, he –

ie, you –

believe that the full LC does not meet the claims of the standard. In particular, it lacks a first information.

Correct?

PROF RANGAN: That’s right.

MR BURGESS: Yes. And that is the only sense in which the full LC messages disclosed in the draft email protocol do not meet claim 1 of the 355 patent. Correct?

PROF RANGAN: By “only sense”, if hypothetically one were to add the full LC out of first information that satisfied this claim and then practiced the scanning as was typically done, I think – I think it would - - -

MR BURGESS: Yes. The method would be within the claim.

313    I accept this submission. Hytera’s point was therefore that the use of the first information was obvious, as was the use of the second information. Consequently, so the argument ran, claim 1 was obvious.

Motorola’s Response and Conclusions

314    As Motorola observed in its closing written submissions in reply, it is apparent that Hytera had shifted its position somewhat by the end of the trial. Whereas it had opened the case on the basis that Mr Kuhrt’s revised methodology showed that the invention was obvious, it had retreated from Mr Kuhrt somewhat by the close of the trial. Rather, by the end of the trial, its position was that Professor Rangan had accepted that the use of a control message, containing information indicating whether activity was present on the channel, was something which would have occurred to him at the priority date and had therefore accepted that the use of the first information in claim 1 was obvious. Further, he had accepted that the use of the second information was also obvious.

315    I do not accept Motorola’s objection that it was unclear what design Hytera was putting forward. Whilst it was open to Hytera to seek to prove the lack of an inventive step by reference to the method composed by Mr Kuhrt, this did not prevent it from also relying on the evidence of Professor Rangan, if it could, to show that the invention was obvious. Hytera bore the onus of proving that the invention was obvious. As a matter of trial procedure, it was not confined, in seeking to discharge that onus, to rely solely upon the evidence of Mr Kuhrt. If it wished, it was entitled to rely upon the evidence of Professor Rangan too.

316    More substantial is Motorola’s submission that Hytera’s submission skated over the question of combining the first and second information in claim 1. Whilst it is true that Professor Rangan said that the full LC message had all the features of claim 1 apart from the first information, and that he would have considered using a first information as part of a scanning method, he also gave evidence that it would have been illogical to combine an activity indicator with the full LC message in the Draft DMR Protocol. Following the exchange between Professor Rangan and Mr Burgess extracted above at [312], Professor Rangan stated at T824.42-43:

PROF RANGAN: It would – it would then – it would then – it would likely satisfy the claim. It wouldn’t be a logical design, but it would likely satisfy ..... the claims.

317    Hytera’s submission overlooks this evidence. Although it was obvious as part of a scanning method to use a first information to indicate the presence of activity, and it was obvious to use a second information of the kind which appeared in the full LC message, it was not obvious to give the full LC message an activity indicator because such a design would not have been logical. In re-examination, Professor Rangan explained why it would not be logical in these terms:

MR MOORE: Professor Rangan, you were asked some questions a few minutes ago about the link control message possibly supplying the second information on the claims, call that, and the possibility of adding a first information to the link control message and in answer to the question you said it wouldn’t be a logical design. Can you explain why you say it would not be a logical design?

PROF RANGAN: Because while – if you took the current link control as the baseline and – we refer to, let’s say, in the draft DMR or in the P25 standard and you added the first information, there would be potentially small benefit in reduction in scan time simply because you could process the – the message slightly quicker, but there would be no – that would be outweighed by the increase in overhead from adding that one bit because you already have the full information with the ID and other fields to determine all the characteristics about the activity of interest, so you’re not getting the benefit of this. In fact, even – so there would – you would be kind of torn away – or maybe I shouldn’t say torn away, but any reasonable designer would not choose to put in that bit at that time.

MR MOORE: Yes, thank you. Mr Kuhrt, I don’t know whether you were following that, but do you agree with that answer?

MR KUHRT: Yes, you would – adding the extra bit would make it – message longer and therefore you wouldn’t get any benefit of a - - -

MR MOORE: Yes, thank you. I have no further questions, your Honour.

318    That is to say, the minimal increase in speed would be offset by the overhead from the extra bit. I accept this evidence and that a person of ordinary skill would not have sought to combine an activity indicator bit with the full LC message. In my view, Hytera’s submission poses the risk identified in Alphapharm of dividing the invention into integers and then addressing the question of whether each integer was of itself obvious, rather than as a combination.

319    Thus, whilst I accept that it was open for Hytera to rely upon Professor Rangan’s evidence to prove that the invention was obvious, I do not accept that his evidence does in fact do so.

320    This then directs attention to the question of whether Hytera has otherwise discharged its burden of proving that the invention was obvious. The only other way it sought to do this was through the evidence of Mr Kuhrt which it did not formally abandon even if its reliance upon it was somewhat muted.

321    Whilst I accept that Mr Kuhrt’s revised methodology does theoretically implement claim 1, there are several reasons why I do not accept that it demonstrates that claim 1 was obvious. First, I am not persuaded that Mr Kuhrt’s revised method is something which a person of ordinary skill would ever have put forward as a method of improving scan time. A solution which led to a reduction in synchronisation patterns and forward error correction and which was inconsistent with the Draft DMR Protocol, is not something which anyone in the field of two-way radios would have contemplated as being sensible as at the priority date. Whilst I accept, as Hytera submitted at [98] of its closing written submissions, that Mr Kuhrt’s solution was viable, in the sense that it would actually work if anyone sought to implement it, I do not accept that it was plausible. As finally presented, it was a method which:

(a)    was inconsistent with the Draft DMR Protocol and hence with the direction in which the industry was heading. As Mr Kuhrt accepted at T767.13-24, what was likely to be standardised in the future was relevant to the design task;

(b)    involved reductions in the size of the synchronisation patterns and forward error correction as the price to be paid for solving what Mr Kuhrt described, at §33 of his third affidavit, as the ‘relatively minor issue’ of scan speed. The fact that the scan speed problem was regarded as a relatively minor issue means that it would be most unlikely that a design solution would be reached which involved, as the price to be paid for that solution, reductions in forward error correction, synchronisation patterns and incompatibility with what was likely to become the standard; and

(c)    was not suitable for large fleets.

322    Secondly, this unreality is itself a function of the fact that the question which Mr Kuhrt was asked was the wrong question. No person would have sought to create an improvement in scan time without this being done in the context of the design of an overall system. Indeed, Mr Kuhrt accepted that what he understood his task to be was to ‘create the ultimate scanning machine’: T770.39. As such, he did not consider weighing up advantages of his method against the disadvantages it might pose to other aspects of the device’s performance: T770.30-34. One consequence of this is Mr Kuhrt’s inevitable acceptance that the task he had been given was artificial and was not a task that he would be likely to have undertaken at the priority date: T771.22-26. Mr Kuhrt would not have embarked upon this task and I am satisfied that no other person of ordinary skill working in the field of digital two-way mobile radios would have done so either.

323    Thirdly, Mr Kuhrt’s revised methodology suffers from the further vice of not only resulting from the wrong initial question but also of being infected with the views of Professor Rangan as to the deficiencies of the first methodology. Mr Kuhrt’s final design was the result of an implausible technical task combined with the views of one of the other expert witnesses in the case. The first method would have resulted in reduced audio quality which makes it an unlikely candidate for something which the person of ordinary skill would have embarked upon. It is even less likely that having embarked on such a course that the person of ordinary skill would, without the interposition of Professor Rangan’s criticisms, come up with the revised method.

324    Fourthly, I am not satisfied that Mr Kuhrt’s scan methodology was not the result of his exposure to the 2005 DMR Standard. Whilst I do not doubt for a moment Mr Kuhrt’s honesty in saying that he had only answered the question he was asked with the knowledge he had at the priority date, I am doubtful whether that was really possible. (This may be contrasted with a similar question under the 764 Patent where I later conclude that it has not been shown that Mr Kuhrt had actually seen the 2012 DMR Standard).

325    Therefore, I am satisfied that Mr Kuhrt’s method is not something that a person of ordinary skill would ever have done.

326    Consequently, I do not accept that Hytera has demonstrated that the invention disclosed in the 355 Patent was obvious and therefore lacked an inventive step.

327    This disposes of Hytera’s ‘obviousness’ case. Neither Professor Rangan’s nor Mr Kuhrt’s evidence establishes that the invention was obvious.

Motorola’s Identification of the ‘Inventive Step’

328    Independently of Hytera’s burden to prove that the invention was not obvious, Motorola in fact identified what it said was inventive about the invention. Since Hytera has not demonstrated that the invention was obvious, it is not necessary to assess whether Motorola’s identified inventive step was in fact inventive.

329    For completeness, however, I record my conclusion that the identified step was inventive:

330    It is reasonably clear from the illustrative embodiment that one way of implementing claim 1 is to use a second information which is provisional and shorter than the full LC message. In the illustrative embodiment, this is achieved by making the second information contain characteristic information in the form of 6 bits: the D1 and D2 bits (voice/data), the I1 and I2 bits (individual/group), and the E1 and E2 bits (emergency/non-emergency). Together with the two 8 bit hashed IDs, which are compressed but provisional versions of the full IDs, these 22 bits constitute the second information. The activity bits, A1 and A2, constitute the activity indicators, that is to say, the first information. In the embodiment, it is plain that this arrangement permits the terminal to determine whether the activity is not of interest more quickly than it would if it remained on the channel to receive the full LC message.

331    As Hytera correctly observed at [94] of its closing written submissions, the combination of the first and second information in claim 1 is silent about the size of the control message. It also does not refer to the payload. Further, claim 1 does not refer to an activity update message or any requirement that the activity update message should be shorter than the full LC message. What is missing from claim 1 is any suggestion that the first and second information should be compressed or abbreviated in some way to achieve the improved scanning time. However, I do not accept that this prevents a finding that the invention involves an inventive step. For reasons I have already given, it is not necessary for the inventive step itself to be defined in the claims. It follows that Hytera’s submission has no bearing on the question of obviousness.

332    When Hytera raised this in its closing written submissions, it elicited this response from Motorola in reply:

HS [100] suggests that the inventiveness in the solution as characterised by Professor Rangan is limited to an embodiment, not the claimed invention. That is not correct. Professor Rangan indicated that the inventiveness of the combination of the first and second information was that it allowed the designer to compress the information in the control message; he explained an example in relation to the hashed ID and explicitly stated that the other embodiments disclosed in the patent demonstrated the same principle (see MS [102]).

The entire discussion ignores the advantage of the claimed invention. The 355 Patent discloses a compressed means of conveying information for scanning, thus allowing for faster scanning. It departs from the prior art in significant respects. Mr Kuhrt would not have arrived at the solution. There is no evidence that anyone else would have.

333    What Motorola had said at [102] was this:

Indeed, this illustrates the inventiveness of the claimed method. Conventional considerations taught against lengthening the control message by including an activity indicator. What had not been recognised was that the use of an activity indicator could permit the compression of other information, including (though not limited to) using a hashed ID rather than a full ID. That is because the presence of an activity indicator would allow the device to dispense with the “null ID”, which was otherwise used in the case of no activity (or idle messages). Hashing the null ID would be unacceptable because it may no longer be identifiable as the null ID and accordingly would not fulfil its purpose. Consistently with this, Professor Rangan identified that what was clever was the idea in general of using first and second information (T807.1-3). He explained that the patent enabled the use of more compressed information than the Full LC message, not just because of the possibility of using hashing (although that was one embodiment), but because of the idea of using different types of “second information” (T792.24-T793.3; T807.9-34; T809.18-T810.46). In this respect, he and Mr Kuhrt were in agreement that the point of the patent was to reduce the number of bursts required before channel rejection (T782.41-46 (Kuhrt); T812.40-42 (Rangan)).

334    There are two elements to this somewhat dense submission. The first concerns the null ID. Professor Rangan gave this evidence at T792.33-793.3:

PROF RANGAN:

…

Now, just to understand that, because I – it had not been discussed up to now, suppose you try to compress, for example, the full ID, say, using hash ID, hashing, but without the – in absence of using the first information. So in this – the issue that would arise is what happens when there’s no activity on the channel. Now, in the event there’s no activity, standard procedure is when you have the full ID to transmit what’s called a null ID. A null ID is the reserved value, typically all zeros, which no actual subscribing unit would have as an ID. So no one will think that it’s for them. So that’s fine if you transmit the full ID. But if you hash it, as we talked about yesterday, there’s a possibility that the hash of the actual user subscriber ID will match the hash of the null ID.

In this case, you will – the subscriber unit will get a match on that compressed or hashed data in every time the base radio is transmitting to no one. And that would greatly reduce the ability to benefit from the reduction in scan time. On the other hand, by adding the first information, you avoid this problem, because that separately indicates that there’s no activity, and then this situation doesn’t arise, so that’s really where the advantage is coming from in this case. Sorry. It’s a bit long explanation. I hope that adds a little bit to the discussion.

335    So the point here is that it was not possible simply to apply a compression algorithm to the full LC message. The usual indicator of no activity, the null ID, might be rendered by the compression algorithm into something which was no longer the null ID. As such, it could not be relied upon, if compressed, to indicate that there was no activity.

336    Professor Rangan’s evidence about this was at T809.14-811.35:

MR BURGESS: Yes. I might approach it a different way, your Honour. Professor Rangan, you made some introductory remarks a little earlier today about what you saw as being part of the value of the invention described in the 355 patent. Correct?

PROF RANGAN: That’s right.

MR BURGESS: And you referred to one value of the first information, which you said Mr Kuhrt had identified, which was that if you had the first information active, inactive, then you can just look at that first bit without considering the rest of the control information, if there’s no activity. Correct?

PROF RANGAN: That’s right.

MR BURGESS: Yes. So that’s one benefit of the first information. But you then refer to a second benefit, which you linked to the hashing of the second information. Correct?

PROF RANGAN: It wasn’t linked specifically to hashing. It’s linking to the concept of compressing information in general, having reduction in information in general. And I mentioned hashing as an example.

MR BURGESS: Yes. So some form of data compression, which is either hashing or some other technique. Is that right?

PROF RANGAN: Some other technique. Yes.

MR BURGESS: Yes.

PROF RANGAN: That’s fair enough.

MR BURGESS: Thank you. And you were – what you said, if I understood it right, was that you were hashing or otherwise compressing the identification information, and that enables you to get a smaller control message that can be sent more frequently. Correct?

PROF RANGAN: Yes. But it could involve, just to be clear, you may not even involve the – hashing or compressing the ID would be - - -

MR BURGESS: Yes.

PROF RANGAN: - - - one way of getting it. But you could, for example, just not have the ID at all - - -

MR BURGESS: Yes.

PROF RANGAN: - - - and look at some other characteristic of it.

MR BURGESS: Professor Rangan, I appreciate that.

PROF RANGAN: Okay. Sorry.

MR BURGESS: Would you agree that that was not the – those other arrangements were not the ones that you referred to in your introductory remarks. Correct?

PROF RANGAN: No. I thought I said it – I – maybe I don’t remember the exact words I said, but I – I think I said that it allows you to – the concept of the patent allows you to compress the information. And then I said, for example, consider the case of compressing the ID.

MR BURGESS: Yes. And your point was if compress the ID, unless you have the first information, there’s a possibility that the subscriber unit may mismatch where there’s no activity. Correct?

PROF RANGAN: That’s right, in that example. Correct.

MR BURGESS: Yes. And I think you were intending to convey that that was a key advantage that you saw in the embodiment described in the 355 patent that uses the hashing. Correct?

PROF RANGAN: The key advantages – just so I’m clear, and maybe we’re saying the same thing. The key advantages allows compression in general and so, for example, in the particular case of hashing, it has disadvantage. But it would have it in other cases, as well, other types of compression that maybe are not even associated with the ID.

MR BURGESS: Yes. Would you pardon me one moment.

PROF RANGAN: Sure.

MR BURGESS: Yes. And just to be clear, in addition to the first benefit of the first information we’ve talked about separately, the point you were making is that the first information addresses the problem of hashing or compression of the second information leading to a potential mismatch where there’s no activity. Correct?

PROF RANGAN: In that example. Correct.

MR BURGESS: Yes. Thank you. And what I was putting to you is that when you say that this 355 patent is clever, that is a key part of what you perceive as being clever. Correct?

PROF RANGAN: It’s an example of – I’m just – I – I just don’t want to say “key”, because I think you might – I might be being unclear, because you might think that the key is associated with hashing. And I’m ..... trying to say that the – a benefit that arises from the patent is that – and a very – a valuable benefit that arises from the patent is that you can compress information in general of which hashing is a particular example.

MR BURGESS: Yes. Thank you. And of which other compression techniques could be used an alternative. That’s your point. Correct?

PROF RANGAN: Yes.

MR BURGESS: Thank you. So could I ask you now, please, to turn to claim 1 of the 355 patent.

PROF RANGAN: Sure.

MR BURGESS: Now, I think you agreed yesterday that claim 1 does not refer to the hashing of any data contained in the control message. Correct?

PROF RANGAN: That’s right. Hashing doesn’t appear here.

MR BURGESS: Yes. And claim 1 also doesn’t refer to any other compression of the data contained in the control message by other techniques; correct?

PROF RANGAN: No, it doesn’t have, for example, the word “compression” in it.

337    So the claimed advantage of claim 1 is that it permits the skilled addressee to compress or abbreviate in some way the second information. What permits this to occur is the use of the activity indicator constituted by first information which effectively takes over the role of the null ID and permits what could otherwise not occur, namely, the compression or abbreviation of the full LC message.

338    It is true that claim 1 does not require the second information to be compressed or abbreviated in this way as Professor Rangan accepted. Indeed, Motorola did not contend for a construction of claim 1 which required the first and second information to be shorter than the full LC message because claim 1 does not mention the full LC message or even a concept like it. Further, whilst there is a reference to a LC message in claim 7, Motorola did not develop a construction argument which saw the first and second information in claim 1 as being shorter than the LC message in claim 7. The illustrative embodiment, and in particular Figure 3, does involve an implementation of claim 1 and claim 7 in which the second information of claim 1 is compressed (by hashing the SUID or TGID using a compression algorithm) or abbreviated (by the use of the D, I and E bits) or both and, it is true, that as such, they are in fact shorter than the LC message of claim 7 as it is embodied in the illustrative embodiment. But this shortening is not in terms required by the patent. Nevertheless, in light of Professor Rangan’s evidence, the person skilled in the art would not implement the invention disclosed in claim 1 without the use of some form of compression of the second information. The insight of the patent is that the first information permits this to be done whereas before it could not.

339    Was it inventive as a scanning methodology, to use information which indicated whether activity was present on the channel together with information which indicated whether the transmission was of interest to the subscriber unit? The important point seems to be this: the presence of the activity indicator (the first information) permits what could not be done in the prior art, namely, the compression or abbreviation of the full LC message. Without the first information, compression of the full LC message gives rise to the possibility of the null ID being compressed to a form which is no longer the null ID.

340    Where the claimed inventiveness relates to the potential for an arrangement that permits the compression of the second information, I am not persuaded that such a solution was at all obvious either by reference to the CGK or s 7(3) documents. Certainly both concepts existed in the prior art, but they had not been combined in a way which proffered to the person of ordinary skill the further potential for compression or abbreviation. The inventive step is realising that the use of the first information to indicate activity would then allow compression or abbreviation.

341    Hytera submitted that the consequence of the fact that claim 1 did not impose any limitations on the size of the control message or the payload meant that it could be implemented in a variety of ways including Mr Kuhrt’s proposed method. However, the fact that the claim can be implemented without regard to the size of the control message or payload does not impact on whether the inventive step identified by Motorola is present. The nominated inventive step is that the combination of the first and second information provided the person of ordinary skill with the potential to make the first and second information shorter than the full LC message. This it certainly does. Whilst framing the inventive step in terms of the potential it gave the person of ordinary skill to do something that the patent did not require may perhaps bring into question the utility of the invention, it does not provide a basis for inferring that an inventive step was not involved. The insight is the one identified by Professor Rangan – the activity indicating first information solves the problem that the full LC message could not be compressed because of the problem presented by the null ID.

342    The first information, it is true, existed in the prior art, but had not been used as part of a scanning method. The second information existed in the prior art as well. But it had not been grasped that combining the first and second information in a scanning method would give rise to the possibility of compression or abbreviation of the identification information. Had it been necessary, I would therefore have accepted Motorola’s identification of the inventive step.

343    In that circumstance, I do not accept that Mr Kuhrt’s evidence demonstrates that claim 1 was obvious. I also reject Hytera’s case that the invention was obvious in light of the evidence of Professor Rangan. Hytera’s attack on the other claims was premised on the same point and fails for the same reasons: HCS(P) ch 3 at [101].

Voir Dire

344    Professor Rangan was cross-examined by Mr Burgess on the possibility of the LC message supplying the first information. I have referred to this above when referring to Professor Rangan’s evidence that to do so would be illogical. Why it was illogical was then elicited by Mr Moore SC in re-examination at T830.1-16 (see above at [317]).

345    Mr Burgess then sought to ask Professor Rangan a further question which, as ultimately expressed, was in these terms at T831.31-33:

MR BURGESS: And if ETSI decided that it wanted to obtain that benefit you referred to in having the first information in these LC messages it could have used part of those reserved bits for that purpose; correct?

346    Objection was taken to this course on the basis that Hytera had no procedural right to ask Professor Rangan this question since Mr Moore’s question had been in re-examination. I accept this submission. The answer given by Professor Rangan at T832.17-44 was admitted on a voir dire basis pending my determination of this issue. It will not be admitted into evidence. Mr Burgess’ subsequent attempt to ask Mr Kuhrt’s a similar set of questions at T833.1-27 depends, for its efficacy, on the answers given by Professor Rangan and will be rejected for the same reason.

Utility

347    Hytera’s point here was a short one. Once it was accepted that claim 1 could be implemented without regard to the size of the control message or the payload, then it followed that the promise of the patent – an improvement in the time taken for scanning – need not be delivered. I accept that it is true that claim 1 can be implemented in the way suggested by Hytera. This is a consequence of Motorola not seeking to contend that any such limitations were present as a matter of construction.

348    An invention is not a patentable invention if it is not, so far as claimed, useful: s 18(1)(c). This requirement is two-fold. The claimed invention must do what it is intended by the patentee to do, and the end obtained must itself be useful: Ranbaxy Australia Pty Ltd v Warner-Lambert Co LLC [2008] FCAFC 82; 77 IPR 449 at [141]. Thus, the invention as claimed must attain the result promised by the patentee. This issue is to be tested against the breadth of the claim.

349    Hytera submitted that the promise of the 355 Patent was an improvement in the amount of time that a mobile station spends scanning a pre-programmed list of channels. Because claim 1 would permit the control message to be split over any number of bursts, including the 7 burst full LC message described in the body of the specification, there need not be any reduction in scan time at all.

350    Motorola submitted that both Mr Kuhrt and Professor Rangan agreed that it would be perverse to implement claim 1 using a second information which was longer than the prior art full LC message. I accept this submission. In relation to Mr Kuhrt, he gave this evidence under cross-examination:

MR MOORE:    And you wouldn’t understand claim 1 of the patent as specifying the use of information that is longer than the full LC message.

MR KUHRT: It depends on the construction. If it’s within the construction of the claim, then I would still read it that way.

MR MOORE: It’s not the point of the patent, as you understand it, is it, Mr Kuhrt?

MR KUHRT: It’s not the point of the patent.

MR MOORE: Yes.

MR KUHRT: I agree.

MR MOORE: And so you wouldn’t read claim 1 as referring to information that was longer than the prior art LC message, would you?

MR KUHRT: Again, it wouldn’t be the point of the patent.

MR MOORE: No, and that would be a perverse application of claim 1, wouldn’t it, to use information that’s longer than the prior art message?

MR KUHRT: It would be a pointless application.

MR MOORE: Yes.

MR KUHRT: Because it’s already there. Yes.

MR MOORE: Yes. And you would agree, wouldn’t you, that what the patent is disclosing to you is that whatever method or code word is used to convey full control information, including information about the message or about other control information, that you can use a shorter method by utilising particular criteria or particular information that is shorter than the full message.

MR KUHRT: Yes.

MR MOORE: And if you had this patent as at July 2004, you certainly wouldn’t implement claim 1 by selecting a second information that was longer than the prior art LC message, would you?

MR KUHRT: No, because you would be creating a system that would take longer to scan.

MR MOORE: Yes. Yes. And you would agree that would be a perverse way of implementing claim 1?

MR KUHRT: Yes.

351    Further, Professor Rangan gave evidence that any reasonable embodiment of claim 1 would not increase the number of bursts over whatever the base system was from which the skilled addressee was commencing. He said this at T811.43-812.3:

MR BURGESS: Yes. And you also agreed yesterday that claim 1 does not require the control message to be split over any identified number of bursts; correct?

PROF RANGAN: That’s right. Although I think, as we were discussing earlier this morning, of course any – I think the terms used were “any – any reasonable embodiment” or the term “no unpointless” or “no un-perverse embodiment” wouldn’t increase the number of bursts on whatever the base system you’re starting but – yes.

352    Thus, whilst I accept that claim 1 on its proper construction does permit both a second information which is longer than the full LC message and the transmission of the second information in more bursts than existed in a base system, I do not accept that these would be reasonable implementations of the claim. As such, I do not accept that they are relevant to the question of utility. In Apotex Pty Ltd v Warner-Lambert Co LLC (No 2) [2016] FCA 1238; 122 IPR 17 at [169], Nicholas J observed:

It is often said that the principle that a claim is bad if it is wider than what is useful is one that must be applied with great caution. As Blanco White explains at para 4–409:

It follows from what has been said that it is often a convenient test of the utility of the invention contained in a claim to consider whether the claim includes forms of the invention which are not useful, but that this test must be applied with very great caution. The function of a claim is to delimit the monopoly given by the patent, not to give instructions for the working of the invention, and it is consequently not necessary that the claim should contain these instructions; even the body of the specification is required to contain only those instructions that the reader cannot supply for himself. It would be unreasonable to expect the claims to contain more. A distinction should accordingly be drawn between cases in which the invention claimed is not useful unless an additional feature or features be added to those claimed (the claim then being invalid), and cases where the qualifications and expedients necessary to make the article claimed work can be, and on a true construction of the claim are, left to the reader to supply for himself. Since in cases where the reader can make the thing work the courts tend wherever possible to construe claims as requiring him to do so, it is not in practice enough to ask whether the claim includes things that are not useful; it is necessary to ask also whether there is anything in the language of the claim positively pointing to some useless construction. The successful utility attacks are nearly always in cases of that sort. Examples are: where a claim specifies two alternative processes or constructions of mechanism, of which only one is useful; or the claim specifies the use of any of a group of chemical compounds, and it is not substantially true that all will work; or the claim includes a series of constructions, and only certain members of the series are useful; or more generally, the claim contains a limitation directed to a particular feature and further limitation of that same feature is needed for utility; or the feature needed for effective working is expressly made optional-as when it is added by a subsidiary claim.

353    In my view, this is a case ‘where the qualifications and expedients necessary to make the article claimed work can be, and on a true construction of the claim are, left to the reader to supply for himself’. Consequently, I reject Hytera’s challenge to validity on the basis of a lack of utility.

MANNER OF MANUFACTURE

354    In its opening written submissions, Motorola identified the 355 Patent as a method of scanning which can be used in a TDMA system to reduce the time required for completing scan operations: at [5].

355    Section 18(1)(a) of the Patents Act imposes a requirement that a claimed invention be a ‘manner of manufacture’ within the meaning of s 6 of the Statute of Monopolies 1623, 21 Jac 1 c 3. The general principles governing that question are set out in the High Court’s decision in National Research Development Corporation v Commissioner of Patents (1959) 102 CLR 252 at 276-277. More recently, the High Court has affirmed and expanded those principles in D’Arcy v Myriad Genetics Inc [2015] HCA 35; 258 CLR 334 at 351.

356    It has been accepted in this Court that a computer-implemented invention will be patentable if, in substance, it constitutes an improvement in computer technology rather than a use of that technology: CCOM Pty Ltd v Jiejing Pty Ltd (1994) 51 FCR 260; Research Affiliates LLC v Commissioner of Patents [2014] FCAFC 150; 227 FCR 378; Commissioner of Patents v RPL Central Pty Ltd [2015] FCAFC 177; 238 FCR 27; Encompass Corporation Pty Ltd v InfoTrack Pty Ltd [2018] FCA 421; 130 IPR 387; Commissioner of Patents v Aristocrat Technologies Australia Pty Ltd [2021] FCAFC 202; 163 IPR 231 (‘Aristocrat’); Repipe Pty Ltd v Commissioner of Patents [2021] FCAFC 223; 164 IPR 1. I do not read Aristocrat as departing from any of the authorities which preceded it. An appeal in that case to the High Court was dismissed by force of s 23(2)(a) of the Judiciary Act 1903 (Cth) when the Court split 3-3: Aristocrat Technologies Australia Pty Ltd v Commissioner of Patents [2022] HCA 29; 96 ALJR 837. As such, the High Court’s decision has no ratio decidendi and stands only for the proposition that the Full Court’s decision stands. As a single judge, I am bound by that decision. What the Full Court is to make of the High Court’s decision is another matter but the approach for a single judge is clear.

357    At [57] of its opening submissions, Hytera submitted that the 355 Patent was a computer-implemented invention which I accept and which I do not understand to be resisted by Motorola. Hytera’s primary submission was that there could be no manner of manufacture where what is claimed merely involves the new use of a known thing for a purpose for which its known properties made it suitable: Commissioner of Patents v Microcell Ltd (1959) 102 CLR 232 at 249-250; NV Philips Gloeilampenfabrieken v Mirabella International Pty Ltd (1995) 183 CLR 655 at 663-664. It then submitted that the 355 Patent, as a matter of substance, was to be seen as being in the nature of a scheme, working directions or directions for use, rather than as an ‘improvement in computer technology’. It did not involve or contribute to any new hardware or software. The patent was merely a method achieved by programming existing hardware to carry out specified steps. There was no claimed ingenuity in the manner in which the methods were to be implemented in the subscriber units, and the patent gave no guidance on how such implementation was to be carried out. In fact, the claimed ingenuity lay in the steps identified in the claims which were no more than a scheme or set of directions.

358    I do not accept this submission. The invention claimed is of the same quality as the curve drawing algorithm in International Business Machines Corporation v Commissioner of Patents (1991) 33 FCR 218 (‘IBM’). The 355 Patent improves the way a particular class of computers – base stations and subscriber units – scan frequencies. The problem of the scanning speed is a problem of computer programming and is relevantly indistinguishable to the problem in IBM of curve drawing on computers. Curve drawing on computers required the use of processing-expensive floating point arithmetic. This kind of floating point arithmetic was expensive in terms of system resources. The solution in that case – the deployment of an algorithm which removed the need to use floating point arithmetic – resulted in an improvement in computer technology. The same is true here. The problem which existed was the problem of how to improve scanning times in a TDMA system. The solution was the use of an activity indicating first information which could permit the abolition of the null ID and therefore permit compression of ID information in the second information. To my mind, these are conceptually indistinguishable. The 355 Patent is plainly an improvement in computer technology.

359    I therefore reject Hytera’s defence that the 355 Patent as claimed does not disclose a manner of manufacture.

INFRINGEMENT

Introduction

360    The 355 Patent involves method, not product, claims. The supply by Hytera of mobile stations and base stations therefore does not per se constitute a primary infringement of the patent since such an act does not involve using the method in the patent. Necessarily, therefore, Motorola put Hytera’s liability on the secondary basis that by supplying the subscriber units and base stations for use together, Hytera had put end users in a position to infringe the patent by using the method. Secondary liability in such circumstances may arise under s 117 of the Patents Act and under the principles of authorisation and joint tortfeasorship.

361    Motorola’s case on infringement differed as between Hytera’s subscriber units and base stations which had not been reprogrammed and those which had. In relation to the former, the ‘Updated Version of Hytera’s Annexure C to its Outline of Opening Submissions’ (‘Updated Annexure C’) classifies the allegedly infringing devices into three categories. Category 1 covers mobile stations that formerly used the short LC message while scanning and includes devices MD652/652G, MD782/782G, PD502, PD562, PD602/602G, PD662/662G, PD682/682G, PD702/207G (UL913), PD702/702G, PD712 EX, PD782/782G, PD792 EX, PD982/982G, X1e, X1p, X1p (UL913) PD502(UL913), PD562(UL913), PD602(UL913), PD662(UL913), PD682(UL913) PD712IS, and PD792IS. Category 2 covers repeater devices that sent the short LC message to Category 1 mobile stations and includes devices RD622, RD962, RD982, and RD982S. Category 3 covers mobile station devices that have never used the short LC message while scanning and includes devices PDC760, and PDC680. At this point, it is useful to note that the ‘short LC message’ refers to a control message in the 2005 DMR Standard that resembles the activity update message in the 355 Patent, including the use of an activity indicator and hashed ID information. As to the latter, Motorola alleges that Hytera’s supply of reprogrammed base stations in a market where unreprogrammed subscriber units continue to be used makes Hytera liable on a secondary basis.

362    It is convenient to deal first with its case on infringement relating to unreprogrammed devices.

Unreprogrammed Devices

363    There are three clusters of issues to be resolved:

(a)    whether an end user who uses an unreprogrammed subscriber unit with an unreprogrammed base station infringes the method of the 355 Patent;

(b)    the legal nature of Hytera’s alleged secondary liability; and

(c)    the particular position of subscriber units known as the PDC760 and PDC680.

Whether the Unreprogrammed Devices Use the Method of the 355 Patent

364    By the end of the trial, Hytera accepted that if the construction issues were resolved against it and the patent was valid, then the use of unreprogrammed subscriber units with unreprogrammed base stations would involve the use of the method of the 355 Patent.

365    There was an irrelevant debate as to whether the base stations infringed the method of the 355 Patent. In my view, neither the subscriber units nor the base stations by themselves infringe the method of the 355 Patent. What infringes the method is when the two types of devices are used together and the subscriber unit is set to scan mode. So much is clear from: (a) the evidence of Professor Viterbo who explained how the Hytera devices operated; and (b) the correct construction of the patent which I have previously explained.

366    Professor Viterbo gave evidence for Hytera about, inter alia, the manner in which the Hytera devices operated in relation to the scan function. This was contained in §5 of his Confidential Annexure EV-6. Motorola submitted, at [40] of their closing submissions, that this was indeed how the scan function operated on the Hytera devices and I therefore take this to be undisputed. Professor Viterbo’s evidence was to the following effect:

(a)    The subscriber unit locates and synchronises with a TDMA channel (frequency and timeslot) from a list of channels in the subscriber unit’s scan list. The subscriber unit does this in order to ascertain if there is any transmission of interest to the subscriber unit on that channel.

(b)    Once the subscriber unit is synchronised with the channel, it will look for and decode the CACH, which contains a “Short LC” message. The Short LC message includes the “Activity ID” and may also include a “Hashed Address ID” (which can be either a subscriber unit ID or a group ID).

(c)    If the Activity ID in the Short LC message indicates that there is activity on the channel, the subscriber unit will hash (i.e., compress) its own pre-programmed full Address ID and then compare the Hashed Address ID that is contained in the Short LC message with its own Hashed Address ID.

(d)    If the two Hashed Address IDs are different, the subscriber unit will switch to the next channel in its scan list.

(e)    If the two Hashed Address IDs are the same, the subscriber unit will stay on the channel and wait to receive the Full LC message. The Full LC message contains the full Address ID of the intended recipient(s) of the communication, which may be an individual subscriber unit or a talkgroup.

(f)    When the Full LC message is received, the subscriber unit will decode it and compare the full Address ID with its own pre-programmed full Address ID. If the full Address ID in the Full LC message is the same as the full individual ID of the subscriber unit, or the full ID of a talkgroup that the subscriber unit is part of, the subscriber unit will start receiving the data or voice in the transmission. If the full Address ID is not the full individual ID of the subscriber unit, or a talkgroup that the subscriber unit is part of, the subscriber unit will switch to the next channel in its scan list.

367    Once it is accepted, as I have, that under integer 5 of claim 1 a determination that activity is of interest does not have to be a final determination, then it follows that this method of the Hytera devices when used together infringes each of the integers of claim 1. The scanning method used by the subscriber units, as described above, embodies integers 1, 3, 4, 5 and 6, and the transmission of the short LC message by the base station embodies integer 2.

368    I therefore accept Motorola’s submission that the base stations and subscriber units when used together infringe claim 1 of the 355 Patent. I did not understand it to be disputed by Hytera that if this were so, the devices also infringed claims 2 to 4. It did dispute that they infringed claim 5 but this turned on its interpretation of ‘targeted’ which I have rejected. I did not understand it to be in dispute, on this hypothesis, that claims 6 and 10 were also infringed.

369    I therefore accept, in principle, that Hytera’s unreprogrammed base stations and subscriber units, when used together by an end user, infringe the method of the 355 Patent. By itself, this does not constitute a primary infringement by Hytera, for the person using the method is the end user and not Hytera. The question then becomes whether Hytera, by supplying end users with the devices, has a secondary liability to Motorola.

The Nature of Hytera’s Alleged Liability for the Infringements in Relation to the 355 Patent

370    The precise basis on which Motorola put Hytera’s liability in relation to each device was set out in a document entitled Updated Annexure C. Motorola submitted that Hytera was liable on five bases:

(a)    s 117(2)(a);

(b)    s 117(2)(b);

(c)    s 117(2)(c);

(d)    authorisation; and

(e)    joint tortfeasorship.

371    It is convenient to consider the position of the subscriber units and base stations separately.

Supply of Subscriber Units

372    Section 117 provides:

Infringement by supply of products

(1)     If the use of a product by a person would infringe a patent, the supply of that product by one person to another is an infringement of the patent by the supplier unless the supplier is the patentee or licensee of the patent.

(2)     A reference in subsection (1) to the use of a product by a person is a reference to:

(a)    if the product is capable of only one reasonable use, having regard to its nature or design—that use; or

(b)     if the product is not a staple commercial product—any use of the product, if the supplier had reason to believe that the person would put it to that use; or

(c)    in any case—the use of the product in accordance with any instructions for the use of the product, or any inducement to use the product, given to the person by the supplier or contained in an advertisement published by or with the authority of the supplier.

373    Hytera submitted that ‘the person’ referred to in s 117(2)(b) (and I assume sub-s (c)) was the person to whom the product was supplied by the defendant. So construed, the provision could not apply where the supply involved an intermediary such as a distributor, dealer or wholesaler. I do not accept this submission. No doubt ‘the person’ referred to in ss 117(2)(b) and (c) is the same person who is referred to at the beginning of s 117(1) but that is quite a different proposition. Contrary to Hytera’s submission, it is clear from the expression ‘the supply of that product by one person to another’ in s 117(1), that the person referred to in the opening words of s 117(1) need not be the same person as the ‘another’ referred to subsequently. If Hytera’s construction were correct, ‘another’ would always mean the first mentioned person, i.e. it would mean ‘that person’ not ‘another person’. This entails on Hytera’s construction that the word ‘another’ is at least incongruous and more likely redundant: cf. the obiter remarks of Besanko, Foster, Nicholas and Yates JJ in AstraZeneca at [442]-[443]. Nor do I accept that Hytera’s submission finds support in the Explanatory Memorandum for the Patents Bill 1990 (Cth) at [171] which merely parrots the Bill. Otiose constructions are to be avoided if possible. Here, the otiosity may be avoided by giving the word ‘another’ its ordinary meaning.

374    For completeness, an operation of s 117(1) which is inapplicable where supply chains are involved is not one which I would embrace unless I was advanced towards it at gunpoint. For the reasons I have given, it does not demand any such thing but, in fact, requires the opposite. Finally, Hytera submitted that the passage referred to above from AstraZeneca provided support for its construction because it ‘may reflect a recognition of this issue’. It contains no such recognition. To the contrary, their Honours very much had in mind supply chains which can be seen by their explicit reference to supply chains at [443].

375    Consequently, Hytera must confront the operation of the provision. Turning then to the evidence, the evidence of Ms Xu, a Product Manager at Hytera, established that the subscriber units were devices that fell within s 117(1). Ms Xu’s evidence, at T153.28-154.18, confirmed the obvious i.e. that one would not use a base station without also using subscriber units, perhaps in the same way that one would not use a car wheel without a tyre:

MR MOORE: And terminal devices and repeaters would normally be used together in a system.

THE INTERPRETER:    That can be yes. That can also be no.

MR MOORE: Well, yes. Let’s take them in turn. You wouldn’t use a repeater without there also being terminal devices.

THE INTERPRETER: Sorry, sir? Would that be - - -

MR MOORE: You wouldn’t use a repeater without there also being terminal devices in a system.

THE INTERPRETER: Correct.

MR MOORE: Yes. And it would be usual for a system to have a repeater in it, correct?

THE INTERPRETER: Yes.

MR MOORE: Yes. And a system that includes terminal devices and repeaters would usually be a system that is set up for a particular customer having regard to that customer’s particular requirements.

THE INTERPRETER: Yes.

MR MOORE: Yes. And, just to clarify that, the systems that we’re talking about here are standalone systems for particular customers.

THE INTERPRETER: To set up for the customer?

MR MOORE: I’m sorry, I didn’t quite hear, Mr - - -

THE INTERPRETER: To set up for the customer?

MR MOORE: Yes, yes.

THE INTERPRETER: Yes.

(Ms Xu gave evidence with the assistance of an interpreter)

376    Extracts from Hytera’s device manuals and product brochures confirm that Hytera suggested to its end users that they use the base stations with subscriber units. Further, Motorola led evidence, contained in vol 16 of the court book, about the contents of the manuals for the subscriber units. The instruction manuals included instructions about the use of the scan mode. If an end user uses a subscriber unit in accordance with those instructions, the unit will interact with a base station in a way which infringes the 355 Patent.

377    This conclusion engages s 117(2)(c). The use of the subscriber unit ‘in accordance with any instructions for the use of the product’ is a ‘use’ under s 117(2)(c). Consequently, being such a use, it is a ‘use’ by the end user of the kind referred to in s 117(1). Since the use of the subscriber unit in scan mode with a base station involves the method of the 355 Patent, it follows that Hytera is liable under s 117(1) through s 117(2)(c). Hytera did not in fact submit that it was not liable under s 117(2)(c), although in its submissions it did not highlight this position. This calculated obscurity can be seen from [41] of its closing submissions and from its Updated Annexure C. Both extensively refer to the many ways in which Hytera does not accept it is liable, for example, under ss 117(2)(a)-(b) or the principles of authorisation or joint tortfeasorship. However, they say nothing substantive about s 117(2)(c).

378    I also accept that Hytera had reason to believe that an end user would use a subscriber unit in scan mode with a base station in terms of s 117(2)(b). It provided advice on how to use the scan mode in the instruction manuals it provided for the subscriber units and, as I have mentioned, it suggested to end users that they should use base stations with subscriber units.

379    I do not think that doing so gave rise just to a risk that the end users would use the devices in an infringing way. It was not a risk; it was a near certainty since this was the predominant ordinary operation of the devices. End users who had base stations did not acquire subscriber units so that they could only use them in direct mode for to do so would be irrational. I conclude therefore that it was inevitable that end users would use the subscriber units with the base stations in a manner which infringed the 355 Patent.

380    It follows therefore that Hytera had reason to believe that its end users would use the subscriber units in scan mode with base stations. Put another way, Hytera had reason to believe that its subscriber units would be used in the manner which Hytera itself suggested that they should be used. That being so, the use by an end user of a subscriber unit in that fashion was a ‘use’ within the meaning of s 117(2)(b). Since that use by an end user would infringe the 355 Patent, it follows that the supply by Hytera to an end user of the subscriber unit constituted an infringement of the patent under s 117(1).

381    Hytera is not, however, liable under s 117(2)(a). The subscriber units could also be used in direct mode which would not result in infringement of the 355 Patent. For the reasons I give later in relation to the reprogrammed devices, I am also satisfied that Hytera is liable both as a joint tortfeasor and for authorisation.

382    Turning then to the position of particular kinds of subscriber units, Hytera made this submission in HCS(P) ch 4 at [41(c)]:

(c)     Various other instances in Motorola’s Closing Attachment A where Motorola has:

(i)    Incorrectly asserted instructions have been given to use products in an infringing manner, when it is accepted by Motorola and/or there is unchallenged evidence that the products do not have (and have never had) the allegedly infringing feature; and

(ii)    Sought to draw inferences about the CPS that are not open to be drawn.

383    This perhaps unhelpful submission leaves the reader to work out what Hytera is talking about. Resort to the Updated Annexure C reveals that there are in fact only two such devices, the PDC760 and the PDC680. Hytera submitted that the unchallenged evidence was that these devices never used the short LC message and therefore their supply could not involve infringement. This was the evidence of Ms Xu in her fifth affidavit at §§5-9. I accept this evidence.

384    I therefore conclude that Hytera is liable for secondary infringement under s 117(1) by reason of ss 117(2)(b) and (c) for the supply of all of the subscriber units referred to in the document Updated Annexure C except the PDC760 and the PDC680.

Supply of Base Stations

385    In my view, it is also clear that Hytera is liable in relation to the supply of base stations under s 117(2)(b). It had reason to believe that end users would use the base station in conjunction with subscriber units and that such subscriber units would utilise the scan function. This is the ordinary functioning of these devices. Whilst I accept that it is possible to use a base station with subscriber units which have had the scan function disabled, I do not think it likely that an end user who had acquired a base station would generally be intending to use its subscriber units in a way which did not involve that scan function. Were it otherwise, the purchase of the base station would be pointless. Although this may be possible in some circumstances (a mistaken purchase by an overzealous end user, for example), I do not think these circumstances would be common. The existence of such circumstances therefore provides no basis for concluding that Hytera did not have reason to believe that its end users might use the base stations with subscriber units with the scan function enabled. Consequently, Hytera is liable under s 117(1) through s 117(2)(b) for its supply of base stations as well. For the reasons I give later in relation to the reprogrammed devices, Hytera is also liable as a joint tortfeasor and for authorisation of infringement.

Conclusions on Unreprogrammed Devices

386    Hytera is liable for infringement under s 117(1) for all of the subscriber units listed in the document Updated Annexure C apart from the PDC760 and PDC680. It is also liable for infringement under s 117(1) in relation to all of the base stations set out in that document.

Reprogrammed Devices

387    After the commencement of these proceedings, Hytera reprogrammed its devices in an effort to ensure that they did not infringe any of the Patents, including the 355 Patent. The firmware giving effect to this aspiration became available from September 2018. Motorola is not, however, satisfied with this. It says that unreprogrammed subscriber units remain in circulation at the level of end users and that where a reprogrammed base station interacts with an unreprogrammed subscriber unit which is in scan mode, the method of the 355 Patent is utilised.

388    The basic problem is this: the reprogrammed base station still transmits the short LC message (i.e. the first information in integer 2 of claim 1) despite its reprogramming. Indeed, the reprogramming of the base station really has nothing to do with the 355 Patent and is directed at the other patents. Hytera’s efforts to prevent infringement of the 355 Patent focussed instead on making sure that a reprogrammed subscriber unit would not use the balance of the method in claim 1 of the 355 Patent upon receipt of the short LC message (i.e. by ensuring that the subscriber unit did not perform all of integers 1, 3, 4, 5 and 6 of claim 1). In this regard, it has been successful for it is not in dispute that the reprogrammed subscriber units do not use the short LC message in a way infringes the 355 Patent. But the fact remains that when an unreprogrammed subscriber unit is used in scan mode with a reprogrammed base station, an infringement of the 355 Patent occurs.

389    Hytera’s defences in relation to the reprogrammed devices are threefold. First, it denies that the supply of reprogrammed base stations can infringe the 355 Patent because the scan mode is performed on the unreprogrammed subscriber unit. Secondly, if the supply of the base stations otherwise would give rise to an infringement, it submits that it was obliged to make sure that the reprogrammed base stations transmitted the short LC message as it was required by ETSI standards. Thirdly, if that proposition is rejected, it says that it has taken reasonable steps to ensure that the reprogrammed base stations do not interact with unreprogrammed subscriber units. These steps consist of various measures designed to ensure that end users present their unreprogrammed subscriber units for reprogramming.

390    Motorola denies each of these propositions. In relation to the steps which Hytera says it has taken to ensure that unreprogrammed subscriber units in the possession of end users have their firmware updated so that they do not infringe the 355 Patent, Motorola says that the steps are insufficient. It propounds a somewhat sterner sets of steps which it says Hytera should now be ordered to take.

391    Four issues therefore require determination:

(a)    Does the use by an end user of an unreprogrammed subscriber unit with a reprogrammed base station infringe the 355 Patent?

(b)    If so, does the supply by Hytera of such a base station to an end user, who has in their possession unreprogrammed subscriber units, give rise to secondary liability in Hytera?

(c)    If so, is a defence nevertheless available to Hytera that it is entitled to supply reprogrammed base stations which transmit the short LC message because the transmission of that message is required by ETSI standards?

(d)    If not, what should the scope of injunctive relief be?

392    There is another issue in relation to all three Patents about additional damages which I deal with separately in Chapter XVIII.

Does Use by an End User of an Unreprogrammed Subscriber Unit with a Reprogrammed Base Station Infringe the 355 Patent?

393    Because unreprogrammed base stations and reprogrammed base stations both transmit the short LC message, the interaction of either with an unreprogrammed subscriber unit inevitably leads to an infringement of the patent. Indeed, as Motorola correctly observed, there is no difference in terms of infringement by an end user between the unreprogrammed base stations and their reprogrammed successors. All that matters is that both transmit the short LC message.

394    Hytera submitted that its base stations did not infringe the 355 Patent because the scanning occurred on the subscriber units. I reject this submission which ignores both the fact that the claim is a method claim, and the fact that its particular method requires the use of two devices: a subscriber unit (integers 1, 3, 4, 5 and 6) and a base station (integer 2). Neither device infringes the patent because neither device is a method. What infringes the patent is an end user who uses the two devices together.

Does Supply of the Reprogrammed Base Stations Give Rise to Secondary Liability in Hytera?

395    Motorola’s asserted basis for liability is s 117(1), and the principles of authorisation and joint tortfeasorship.

396    Dealing first with s 117(1), I have rejected Hytera’s submission above, that s 117(1) is not engaged where the end user acquires the device from an intermediary in the supply chain. Insofar as s 117(2)(b) is concerned, the question is whether Hytera, despite the steps it has taken, had reason to believe that the end user would use the reprogrammed base station with an unreprogrammed subscriber unit. In relation to s 117(2)(c), the question is whether the use of the reprogrammed base station, in accordance with any instructions on its use, would infringe the 355 Patent.

397    Assessment of both of those propositions requires one to consider the steps which Hytera has taken to require unreprogrammed subscriber units already in circulation to be presented for reprogramming. An assessment of the facts relating to this situation may be divided into those facts which Motorola says establish that Hytera has a secondary liability in relation to the supply of reprogrammed base stations, and those facts which Hytera says show that what it has done is sufficient to avoid that liability.

Motorola’s Factual Contentions about Secondary Liability

398    Mr Li was a Technical Director at Hytera Australia. He gave evidence about the chronology of events surrounding the release of the reprogrammed devices into the Australian market. His evidence showed that Hytera released the firmware for the reprogrammed devices in late 2018: Li-1 at §35. However, it was not until Monday, 25 March 2019 that it became the case that all the devices shipped from its Australian warehouse were the reprogrammed devices: Li-1 at §37. From 1 January 2019 to 25 March 2019, Hytera supplied 810 unreprogrammed subscriber units and 19 unreprogrammed base stations. Between 26 March 2019 and 30 November 2019, Hytera supplied 4,241 reprogrammed subscriber units and 107 reprogrammed base stations: Li-1 at §43.

399    Mr Li estimated that in 2019, 30-40% of the systems for which Hytera provided pre-sale support were intended to be sold to end users who had, and would retain, existing unreprogrammed devices: Li-1 at §55(b).

400    Commencing in November and December 2019, Hytera began taking steps to ensure that end users’ existing devices were upgraded before reprogrammed devices were supplied: Li-1 at §72ff. I discuss these steps in the next section.

401    For the purposes of Motorola’s secondary infringement case about the reprogrammed base stations, the critical element is that there continued to be end users of unreprogrammed subscriber units to whom these reprogrammed base stations were provided. Based on Mr Li’s evidence, it is open to infer that 30-40% of the end users to whom reprogrammed base stations were supplied in 2019 had in their possession unreprogrammed subscriber units. It is also open to infer, and I do, that it is highly likely that in these cases, the use of the reprogrammed base station with the unreprogrammed subscriber units would have resulted in an infringement of the 355 Patent. Although it is possible that the subscriber units could have been used only other than in scan mode, this strikes me as distinctly unlikely.

402    However, this reasoning, at least in this form, only holds until November and December 2019, when on Mr Li’s evidence, Hytera began taking steps to ensure that when reprogrammed devices were supplied to end users, their existing devices were also updated with the new firmware. To those steps it is now necessary to turn.

Hytera’s Factual Contentions

403    Hytera submits that it took seven steps to minimise the chance that a reprogrammed base station would be used in a manner which would infringe the 355 Patent: HCS(C) Mod I at [26]. These steps were that Hytera:

(a)    Undertook to Motorola not to exploit non-reprogrammed devices or supply non-reprogrammed firmware;

(b)    Entered into contractual agreements with 19 of its 29 dealers requiring them to upgrade the firmware on any non-reprogrammed devices in the possession of an end user before the dealer supplied that end user with any reprogrammed devices. Evidence was also given that Hytera intended to monitor compliance with these agreements;

(c)    Entered into a contractual agreement with its sole distributor, Logic Wireless, requiring it to use its best endeavours to ensure that it communicated with its dealers that any non-reprogrammed devices were to be upgraded before being supplied to an end user, and that end users’ existing devices were to be upgraded to the latest firmware version before new devices were supplied. Under the same agreement, Logic Wireless also agreed to provide its dealers with access to the latest firmware, CPS, and other tools required to upgrade the devices;

(d)    Sent emails to its dealers and its sole distributor, Logic Wireless, regarding upgrading any non-reprogrammed devices in their possession to the reprogrammed firmware;

(e)    Completed an upgrade of firmware on non-reprogrammed devices held by Logic Wireless;

(f)    Implemented and maintained a system such that when it provided pre-sale support to its dealers or its sole distributor, it made enquiries as to whether the end user had existing non-reprogrammed devices and, if so, required an upgrade of the firmware on those devices; and

(g)    Updated the webpages and product manuals on its Australian website that refer to the use of existing Hytera devices to state that they ‘should be upgraded to Hytera’s iM or /S firmware before being used as part of a system’.

404    The evidence of Mr Li established these matters. I did not apprehend Motorola to dispute Mr Li’s evidence. Rather its attack was focussed on whether the steps Mr Li described could be described as ‘reasonable steps’. The principle mechanism by which it did this was to posit seven steps which it contended Hytera could have taken which would be more efficacious in preventing an infringement of the 355 Patent from happening: MCS(C) Mod I at [60]. These seven steps were as follows: