On Friday 29 January, Mr Justice Birss gave judgment in the second UK patent trial between Unwired Planet, Samsung and Huawei, holding that two of Unwired Planet's patents are invalid for obviousness. The case, despite starting out as a multi-layered, multiple obviousness references matter eventually turned on an assessment of just one piece of prior art, with the defendants accepting that if the patents were valid then they were both infringed and essential.

Background

This was the second of five "technical trials" to assess the validity and infringement of Unwired Planet's six patents in suit in the UK. After Unwired Planet brought a claim for infringement of six of its patents by Google, Samsung and Huawei, five of which patents were said to be essential to standards produced by the European Telecommunications Standards Institute (ETSI), the defendants responded by asserting that the patents were invalid and not infringed.

Additionally, the defendants allege that Unwired Planet and Ericsson, the prior owner of the five standards essential patents (SEPs), have breached competition law by, among other things, seeking to enjoin the defendants from infringing the SEPs. A summary of the "FRAND" and competition law defences, including an explanation of SEPs, can be found here.

Following a number of case management conferences, it was decided that the proceedings would be divided into five "technical" trials, followed by a 13 week trial to assess the competition law and FRAND issues. Google and Unwired Planet settled their dispute, but it remained for Samsung and Huawei to argue their respective defences in the technical trials.

In the first technical trial, Unwired Planet emerged victorious, with Birss J deciding in November 2015 that EP (UK) 2,229,744 was valid and infringed by Samsung and Huawei. A summary of the decision following the first technical trial can be found here. Unwired Planet also succeeded in a parallel German trial with judgment being handed down in January this year.

Following the second technical trial, Birss J's judgment was handed down on 29 January 2016 ([2016] EWHC 94 (Pat)). This time Unwired Planet was not successful.

The trial

The second technical trial concerned two of Unwired Planet's patents, EP(UK) 2,119,287 and EP(UK) 2,485,514 (the "287 and 514 patents" respectively). The patents are both titled "Self configuring and optimisation of cell neighbours in wireless telecommunications networks"; with the 514 patent being a divisional of the 287 patent.

Both patents were said to be essential to the LTE (4G) telecommunications system, meaning that device manufacturers/operators providing 4G equipment/services would need to implement the patented technology and therefore infringe the essential claims of the patents in order to comply with the relevant 4G standards. The essentiality of both patents was disputed by the defendants prior to trial, but had been conceded by the time the judge came to make his decision.

It therefore remained for Birss J to decide whether the patents were valid, in which case they would be infringed by Samsung and Huawei, or invalid, in which case they would be revoked. Birss J's decision came down on the side of revocation.

The technology

The patents teach a method of communicating a "neighbour cell list" to a serving base station. Telecommunications networks are comprised of a conglomeration of "cells", whereby each cell is served by a base station (i.e. an antenna) which communicates with mobile devices (i.e. mobile telephones) within the cell - hence the term "cell phones". Depicting the network simplistically, one can imagine a series of tessellating hexagons not dissimilar to a honeycomb, with each hexagon constituting a separate cell and controlling a given capacity of mobile telephones.

When a mobile telephone user passes from one cell to the next, for example while a caller is sitting as a passenger in a moving car, the telephone will need to drop its connection with the first cell and establish a connection with the second cell. This process is known as a "handover".

In order to perform a successful handover, a mobile phone will need to know the characteristics of the cell which it is entering, and vice versa. To facilitate the handover, a serving (i.e. current) base station may connect directly with a target base station in order to provide it with the characteristics of the existing connection. This base station to base station connection is known as a "transport connection". To set up a transport connection, and to facilitate handover generally, the serving base station therefore needs to know the identity of its neighbour. Accordingly, each base station stores a "neighbour cell list", identifying the cells that surround it.

Cells can be identified by "unique identifiers" or "non-unique identifiers". Unique identifiers are, as one might suspect, unique to each cell, for example a serial number which can be broadcast by a cell in its control channel. Non-unique identifiers, on the other hand, may be identified from a cell's regular transmissions, and, while not unique, may be sufficient to distinguish a cell from its locality. Unique identifiers are more reliable, but they are also more cumbersome. The use of non-unique identifiers is therefore generally more resource efficient, and it can be considered advantageous for non-unique identifiers to be used where possible.

The patents require a mobile phone to identify surrounding cells using non-unique identifiers. However, if a non-unique identifier is not included on the serving base station's neighbour cell list (i.e. if the target cell cannot be identified), the mobile phone is required instead to provide the base station with a unique identifier for the corresponding cell. The base station can then ascertain the IP address of its neighbour and update its neighbour cell list accordingly.

The patents therefore teach a method which removes the need for manual involvement when maintaining neighbour cell lists. The development of self-optimising networks (SONs), towards which the patents are directed, was an objective of the operators involved in developing the 4G standards.

The validity attack

Samsung and Huawei pleaded that the patents were obvious on two counts: first over Document R2-062303, a document which had been proposed by Qualcomm as part of the LTE standardisation process ("Qualcomm"), and secondly over common general knowledge alone.

The defendants also claimed that the patents were invalid for insufficiency and added matter, both of which claims were rejected.

The decision

Birss J concluded that the skilled team would be motivated to use Qualcomm as a starting point, and that the patented method was an obvious implementation of Qualcomm. He rejected Unwired Planet's submission that the defendants' approach was tainted with hindsight, and rejected the submission that the defendants' approach involved "numerous steps".

However, the defendants' case that the patents were obvious over common general knowledge alone was rejected, as were their assertions that the patents were invalid for sufficiency and added matter. Unwired Planet proposed amendments to the patents should they be found invalid in their current form, but the amendments were not sufficient to improve the validity position in Birss J's opinion.

Obviousness

Birss J described the obviousness arguments as arising from the same context - the development of the LTE standard and in particular the work done by the relevant committees: TSG-RAN Working Groups 2 and 3.

Before going on to consider whether the patents were obvious, Birss J repeated the statement of Kitchin J in Generics v Lundbeck:

"The question of obviousness must be considered on the facts of each case. The court must consider the weight to be attached to any particular factor in the light of all relevant circumstances. These may include such matters as the motive to find a solution to the problem the patent addresses, the number and extent of the possible avenues of research, the effort involved in pursuing them and the expectation of success".

Section 2.1 of Qualcomm stated as follows:

"If an eNode B would like to establish an association to another eNode B, the source eNode B needs to know the IP address of the target eNode B. It is expected that the UE cannot know the IP address of an eNode B that is found through radio measurement. However it is sensible to assume that the identification of the unique identity of a measured cell would be possible [2]. As example, in UMTS the "PLMN Identity" (5-6 digits) and the "Cell Identity" (28 bits) together provide a globally unique identifier of the cell.

After receiving a measurement report from the UE the serving eNode B needs to identify the IP address of the eNode B that the measured cell is belonging to.

The following section proposes a mechanism to achieve this requirement".

Noting that an "eNode B" is, in LTE terminology, a base station, and a "UE" is (among other devices) a mobile phone, Birss J considered this section of Qualcomm to be stating that the IP address of a target base station is not something that a phone can derive by measurement (i.e. by measuring parameters such as signal strength, or by decoding and interpreting radio signals being transmitted within a cell), but the unique identifier of a target base station is something that a phone can obtain by measurement.

A further section of Qualcomm noted that, "the operator deploys servers that have a mapping database for cell IDs and IP addresses of eNode Bs". In other words, the base station can receive a unique neighbouring cell identification (cell ID) from a mobile phone, and can then request the IP address of that neighbouring cell by providing the Cell ID to the server database. This allows the base stations to establish a transport connection with one another.

Thus, Birss J explained that the differences between Qualcomm and the inventive concept of the patents were that:

  • Qualcomm did not refer to the phone sending the base station a non-unique identifier for neighbouring cells; and
  • Qualcomm did not contain a step whereby the serving base station determines from the non-unique identifier that it needs to obtain a unique identifier and therefore instructs the phone to obtain it.

The defendants argued that Qualcomm represented an advancement in the art and would therefore be seen as "a good starting point for implementing a method of creating, updating and optimising the eNode B's neighbour cell list".

Unwired Planet argued that Qualcomm was just one possible approach to the problem of self-organising networks, and was in fact not the "natural solution". The natural solution, Unwired Planet proposed, would be for neighbour cell lists to be updated centrally rather than within each base station as proposed by Qualcomm. However, Birss J agreed with the defendants' expert evidence that Unwired Planet's so called natural solution would not be seen by the skilled team as a sufficiently reliable method to be allowed to run automatically, meaning that other options would be explored by the skilled team. The judge added that the skilled team would be well motivated to look in detail at a way of implementing Qualcomm.

Taking Qualcomm as a starting point, the defendants argued that the obvious way for a skilled team to implement Qualcomm would fall within the method claimed by the patents. In a section headed "What is obvious over the Qualcomm document", Birss J considered the defendants' approach, which required implementing the method in Qualcomm - i.e. establishing a transport connection between base stations based on a unique identifier supplied by the phone - "as an additional facility on top of normal measurement reporting" (recall that measurement reporting allows a phone to report non-unique identifiers to its serving base station).

Unwired Planet argued that this could be achieved in alternative ways to the patented method, for example the unique and non-unique identifiers could be reported together to reduce signalling, which would be outside the scope of the patent.

However, this was not enough to defeat the defendants' obviousness challenge. Birss J concluded:

"I find that the skilled team would see both approaches as having obvious advantages and disadvantages which would be balanced in a standard and wholly obvious trade off exercise. The defendants' approach trades off extra signalling (a message from the eNode B to the phone) against a lower burden on detected set reporting. Unwired Planet's approach reduces the signalling but increases the burden on detected set reporting. Since both approaches are obvious over Qualcomm, it is not necessary to go on and consider which would be chosen, but in case it matters, I find that the skilled team would firmly prefer the defendants' approach. The burden of an extra message from the eNode B is obviously worth it as opposed to requiring all detected set reporting to include the unique ID of all detected cells."

The case was therefore one in which the existence of multiple different avenues did not show that the avenue actually pursued and claimed in the patent was inventive. Birss J summarised the law in this context as follows:

"As a matter of law the availability of different avenues may or may not show that a step is inventive. Multiple avenues can be indicative that one avenue, which leads to the invention, is not obvious but on the other hand the existence of a number of obvious ways forward does not mean one of them is not obvious. It depends on the facts".

Finally, the judge rejected the defendants' challenge that the patents were obvious over common general knowledge alone. He was "wholly unconvinced" that a skilled team thinking about self-configuration and SON based on the common general knowledge alone would think of using the unique identifier at all. It was not used in this way in UMTS or anywhere else in the common general knowledge.

Insufficiency and the squeeze with obviousness

The defendants challenged the sufficiency of the patent but the judge noted that no specific difficulty in implementing the invention had been identified or relied upon. Although at the relevant time the LTE standard remained under development and this would inevitably make things difficult for the skilled person (or team), that was not because there was anything particularly difficult about putting the invention into practice, given the patent.

More generally, Birss J's comments on the inter-relationship between the defendants' case on obviousness and their case on insufficiency are noteworthy. The judge said:

"Part of the way the defendants put their case was to submit that the sparse nature of the disclosure in the specification to support the implementation of the claimed invention meant that the patent assumed a high level of skill on the part of the skilled person and so, for obviousness, a higher level of skill on the part of the skilled person should be applied. I believe this proposition is wrong in principle. It is close to the argument which was rejected in Conor v Angiotech and should be rejected for the same reasons. It is the properly construed patent claim which counts not the content of the specification, such as the availability of examples. The latter cannot alter the level of skill required of the skilled person when considering inventive step. Otherwise two claims for the same invention over the same prior art would be judged differently for obviousness depending on whether one patent contained a worked example and the other did not. If I may borrow in part the words of Lord Hoffmann in paragraph 19 of Conor, a patentee is entitled to have the question of obviousness determined by reference to the claim and the objectively determined skilled person, not by reference to the extent of their disclosure in the description."

Comment

Birss J's 29 January 2016 decision illustrates how an invention may be "obvious to try" even where there are alternative feasible steps that may instead have been taken. The assessment being a fact-dependent exercise, it is necessary to consider the extent to which a claimed implementation would be preferred relative to its alternatives. This includes consideration of the motivation of the skilled team to implement a method disclosed in a given prior art reference in the first place.

Birss J's decision also provides further confirmation that when defining the invention to be assessed for the purposes of a challenge of obviousness, it is the properly construed patent claim which the courts must consider rather than merely considering the extent of the disclosure provided in the patent specification.