Insights High Court finds mobile telecoms patent obvious over the prior art in third technical trial in Optis v Apple litigation



In this litigation involving multiple trials, Optis alleges that Apple has infringed eight telecommunications Standard Essential Patents (SEPs) by Apple’s 3G and 4G connected devices.

Four technical patent trials (Trials A – D) have been listed in the High Court between October 2020 and January 2022. Two of those have been determined (A and B). In Trial A the court found one of the patents, which subsequently expired, to be valid, essential and infringed (although the findings on essentiality and infringement have since been overturned by the Court of Appeal — see item below). In Trial B, the court found a second patent, which has not expired, to be valid, essential and infringed.

Trial E will determine the terms of a global (following the Supreme Court decision in Unwired Planet v Huawei [207] EWHC 711 (Pat)) FRAND licence and rule on various allegations made by Apple of anti-competitive behaviour by Optis. This has been listed for trial in June and July 2022. The parties are far apart on what licence terms would be FRAND.

This latest judgment relates to the third of the technical trials, Trial C, which concerned three European (UK) SEPs belonging to Optis. The patents had been declared essential to LTE (4G). They were all closely related and from the same family. Accordingly, Mr Justice Meade referred to just one of them to make his findings (the Patent). The Patent was originally applied for by LG Electronics Inc and Optis was the assignee.

The Patent was entitled “Method for transmitting and receiving control information through PDCCH” (Physical Downlink Control Channel). The specification began with some general teaching about the LTE standard and the PDCCH, a type of channel that can carry control information, i.e., information comprising messages used to configure and manage the network, such as signalling to indicate whether a data packet has been received accurately. Thereafter, it identified some Ericsson slides (see below) and then described the meaning and use of the function of Claim 1

Claim 1 of the Patent stated: “A method for a User Equipment, UE, to receive control information through a Physical Downlink Control Channel, PDCCH …”.

As for the inventive concept of the Patent, essentially, the problem the invention aimed to solve was how to allocate PDCCH search spaces. The answer given by the invention was to use a LCG (Linear Congruential Generator), a recursive random number generator (RNG) algorithm.

Apple conceded that the Patent was indeed essential and therefore infringed if valid. Therefore, the trial related to validity only. Apple argued that the Patent was invalid as it was obvious over two pieces of prior art: (i) Slides R1-081101 entitled “PDCCH Blind Decoding – Outcome of offline discussions” presented at a RAN1 meeting of 11-15 February 2008 (Ericsson); and (ii) The Art of Computer Programming, Vol. 2 Seminumerical Algorithms, 2nd Ed (1981), Chapter 3 “Random Numbers”, pages 1-40 (Knuth).


Skilled person and common general knowledge

Optis said that the skilled person would be a person engaged in work on RAN1. Apple said that the skilled person would be a person engaged in the narrower field of the PDCCH specifically.

Meade J noted that the problem that the invention aimed to solve was a narrow one of how to allocate PDCCH search spaces. The established field in which this problem was in fact located was RAN1. The PDCCH was not a field in its own right. Therefore, Meade J rejected Apple’s argument that the skilled person would have been a PDCCH person.

Optis’ view of the skilled person had the benefit for Optis that RAN1 clearly was an established field, and that the problem that the invention aimed to solve was within its scope. However, Meade J said, RAN1 was a broad umbrella and probably no one real person had the knowledge, skills and experience to cover the whole of its field. This was evidenced by the number of people participating in the discussions and by the fact that major companies had teams on RAN1.

Therefore, Meade J concluded that the skilled person was a “RAN1 person” of the kind attending meetings or providing back-up, with the aptitudes and common general knowledge appropriate to the tasks that RAN1 would require of them.

To show the agreed common general knowledge, Meade J provided a summary and explanation of LTE (4G) and RAN1.

Obviousness over Ericsson

Using the Pozzoli structure to examine obviousness over Ericsson, Meade J said that the difference between Ericsson and the unspecified claims of the Patents was the use of the function of those claims instead of the Ericsson function. In other words, the inventive concept of the unspecified claims lay in the whole of the function and not just in the LCG part.

Under Pozzoli question 4, on the primary evidence, Meade J found that the Ericsson function would be identified by the skilled person as being deficient.

As for what would happen next, Meade J accepted Apple’s argument that the skilled person would look to remedy the problem with the randomisation element by searching in the literature for an established and understood way to generate randomness, i.e., an appropriate RNG. In Meade J’s view this would be the most natural way forward. It was the reliable, routine, systematic approach of the uninventive skilled person, he said.

Meade J also accepted Apple’s argument that, having embarked on a literature approach, the skilled person would find their way to Knuth and therefore to LCGs. The expert evidence showed that LCGs were very well known, had a long history, and were fast and easy to understand and implement. If the skilled person wanted to use a RNG they would look it up and come across LCGs as one of the categories.

Accordingly, Meade J found that the specified claims of the Patent were obvious over Ericsson.

Meade J also found that the specified claims, which described the values to be used for the modulus, the multiplier and the increment, were obvious options to adopt.

As for Knuth, Meade J found that the Patent was not obvious over this second piece of prior art. (Optis Cellular Technology LLC v Apple Retail UK Ltd [2021] EWHC 3121 (Pat) (25 November 2021) — to read the judgment in full, click here).