What's the time (zone)? LTE SEP found valid, infringed & essential by UK High Court

18 minute read
30 November 2015


Unwired Planet is the victor in the first of five technical trials which leaves Huawei and Samsung considering their chances on appeal.

In January 2013, Unwired Planet acquired a portfolio of patents from Ericsson. The majority of these patents have been notified as essential to the 4G standards and this is the judgment from the first of the technical trials. Our earlier article sets out the background in detail: Unwired Planet v Huawei & Samsung: Samsung given permission to appeal strike out.

In brief, Birss J has held Unwired Planet's patent to a polling system for a wireless telecommunications network to be valid, infringed and essential. The patent is infringed by telecom networks which operate in accordance with standard 3GPP TS 36.322 release 8 version 8.8.0.

The judge's reasoning included some interesting points on the reference time zone for considering whether a document has been made available to the public before the priority date, and on the use of secondary evidence in relation to obviousness.


In March 2014, Unwired Planet brought a claim for patent infringement against Huawei, Samsung and Google. The claim was brought for infringement of six of Unwired Planet's patents, five of which were said to be essential to standards produced by the European Telecommunications Standards Institute (ETSI). All of these asserted 'standard essential patents' (SEPs) were transferred to Unwired Planet from Ericsson (along with over 2,800 other patents) in January 2013.

Following a number of case management hearings the court listed five 'technical trials' to hear the validity, infringement and, for the SEPs, essentiality issues in relation to each of the six patents in suit, followed by a thirteen week 'non-technical' trial to hear associated issues regarding SEP licensing on 'fair, reasonable and non-discriminatory (FRAND) terms, and the defendants' competition law defences.

Birss J's 23 November 2015 decision follows the first of the technical trials. The dispute with Google having settled, the remaining active defendants were Huawei and Samsung. They challenged the validity of the patent on the basis of anticipation and obviousness. They also challenged the claimed priority and further challenged infringement and essentiality.

The Patent

Birss J's 23 November 2015 decision concerned Unwired Planet's European patent (UK) no. 2,229,744 (the Patent). The Patent is concerned with an efficient 'polling' system for a wireless communication network. The 'poll' in this context is a message sent by a transmitter of data, to the receiver, to ask the receiver to tell the transmitter what information has been received.

The relevant claims alleged to be independently valid are as follows:

Claim 1: Method in a first node for requesting a status report from a second node, the first node and the second node both being comprised within a wireless communication network, the status report comprising positive and/or negative acknowledgement of data sent from the first node to be received by the second node, wherein the method comprises the steps of:

  • transmitting a sequence of data units or data unit segments to be received by the second node, the method further comprises the steps of:
    • counting the number of transmitted data units and the number of transmitted data bytes of the transmitted data units, and,
    • requesting a status report from the second node if the counted number of transmitted data units exceeds or equals a first predefined value or the counted number of transmitted data bytes of the transmitted data units exceeds or equals a second predefined value.

Claim 9: Method according to any of the previous claims 6-8, wherein the steps of resetting the first counter and the second counter is performed when the first predefined value is reached or exceeded by the first counter or when the second predefined value is reached or exceeded by the second counter.

Construction, infringement and essentiality

Birss J referred to Lord Hoffmann's summary of the law on claim construction in Kirin Amgen [2005] RPC 9, noting that construction of patent claims "is concerned with what a reasonable person to whom the utterance was addressed would have understood the author to be using the words to mean". He also noted Sir Robin Jacob's summary of the principles to be applied in Virgin Atlantic Airways v Premium Aircraft Interiors, commenting that claims are not to be construed alone:

"...purpose is vital but on the other hand purpose is not the be-all and end-all. One is concerned with the meaning of the language."

There were three points on construction and it was agreed between the parties that if Unwired Planet's construction were preferred then the claims would read onto the standard and therefore the patent would be both essential and infringed.

The points on construction do not raise any particular points of law and it is enough to note that Unwired Planet, which was contending for a broader reading of the claim language than the defendants sought, won its case. The patent was found to be both essential and infringed. The final determination of the case therefore depended on whether the patent was valid.

Challenges to validity

With regard to validity, the defendants raised issues on priority, lack of novelty in relation to intervening art and obviousness. All three arguments raised interesting and generally applicable points of law.


Birss J referred to the Court of Appeal's summary of the law on priority in Medimmune v Novartis [2013] RPC 27. He agreed with the defendants that the court is not concerned with what is made obvious by the priority document, citing Floyd LJ in HTV v Gemalto [2014] EWCA 1335 (Civ)).

Unwired Planet argued that the fact that a claim may be wider in scope than a specific embodiment described in the priority document does not mean priority is lost, relying upon AC Edwards v Acme [1992] RPC 131 and AP Racing v Alcon [2014] EWCA Civ 40. On this, Birss J said:

"...in a case in which a claim has a wider scope than that which is disclosed in a priority document, I do not accept Unwired Planet's submission if it goes as far as saying that the fact that such a claim satisfies an AC Edwards added matter test is necessarily enough to satisfy the test for priority. The AC Edwards line of cases is not followed in the European Patent Office (EPO). That UK line of authority rests on the point that added matter is not concerned with claim scope at all but with what information is disclosed by the claim language. If a claim of wider scope does not disclose any new matter then the added matter test is satisfied but to maintain priority such a claim must also satisfy the principle that its scope is commensurate with the relevant technical contribution, in this case the technical contribution of the priority document (Biogen v Medeva [1997] RPC at 48-49)."

The defendants' challenge to priority was essentially that the priority document did not contain an enabling disclosure of four aspects of the claim language, when they were construed as contended for by Unwired Planet. The priority document, argued the defendants, when properly construed as a whole, presented the 'Detailed Description' section as a detailed explanation of what the invention actually is, rather than as exemplary.

Birss J disagreed, for the following reasons:

  • First, looking at the whole document, the skilled person would understand that the key concepts are disclosed in the summary section in a general way and would not expect details in the Detailed Description document to be limiting.
  • Second, based on the language of the Detailed Description section, the skilled person would understand that i) the first part was an example that was "obviously" not limiting and ii) an explanation that something "can be achieved by a method as described in the following..." described how something can be done, not how it must be done. The Detailed Description section was therefore also not limiting.

Turning to the particular issues, Birss J found that all the relevant parts of the claim language, written as they were in general terms, were clearly and unambiguously derivable from the priority document. To the extent that claim 1 had a wider scope than the Detailed Description in the priority document, that scope was commensurate with the technical contribution made by the priority document.


The defendants' challenge of lack of novelty relied upon the Ericsson TDoc document. This document was uploaded to a publicly accessible server for consideration of an ETSI Working Group Meeting. As soon as it was uploaded, the document was freely available on the internet to anyone anywhere in the world.

It was not in dispute that the Ericsson TDoc document amounted to an enabling disclosure of the invention. But did it form part of the 'state of the art'?

Birss J noted that the starting point in this analysis must be section 2(2) of the Patents Act 1977 and Article 54(1) EPC with which it corresponds. The judge paraphrased them both as requiring that:

"the state of the art shall be held to comprise everything made available to the public before the priority date"

The judge stressed that the words refer to things made available before a date. The date mentioned is the priority date. There is no reference to ascribing a calendar date to an item of prior art (or indeed a time).

Birss J said that there are two questions:

  1. What is the priority date?
  2. Was the putative prior art made available before that date?

At any given moment, the time and date around the world are different. Thus in order to give it meaning the priority date has to be based on some frame of reference. The only frame of reference which makes sense, said the judge, is the one at the patent office at which the priority document was filed. Using any other approach would mean that an event which happened after the priority document was filed could count as prior art depending on the interplay of various time zones and that, as the judge noted, would be a "very odd result"!

Birss J noted that this view was consistent with the decision of the EPO's Opposition Division dated 31 July 2015 concerning application no. 03 012 734.4 by Innovative Sonic Ltd. That decision was apparently inconsistent with the EPO's Examining Division's decision of 6 August 2013 concerning application no. 09 733 661.4 by Huawei, which Unwired Planet contended was wrong.

Having characterised the priority date as the date of the document's filing in the United States Patent and Trademark Office (USPTO) (8 January 2008), the judge then considered whether the Ericsson TDoc was made available before that date. The uploading occurred at 08:36 CET / 07:36 GMT / 02:36 EST on 8 January 2008. In Hawaii the time and date at this point was 21:36 on 7 January 2008.

The key point was that because the priority document was filed in the USPTO, it was necessary to consider whether from the perspective of the USPTO in the EST time zone, the Ericsson TDoc was made available before 8 January 2008. From the perspective of that time zone, the upload occurred at 02:36 on 8 January 2008. This was not before the priority date, and so the Ericsson TDoc was not state of the art for the purposes of the Patent and could not form the basis of a challenge to novelty.

This might perhaps seem harsh for the defendants in the present case because the Ericsson TDoc was in fact made available to the public before the moment in time that the priority document was filed. The judge noted the "justice" in the defendants' submissions. However, if the law was as the defendants wished it to be, it would catch as prior art things made available to the public at a time after the priority document was filed. Birss J said:

"The facts in this case flatter the defendants' argument. Consider what would happen if the content of a priority document filed at the Japanese Patent Office early in the morning was then placed on the internet one hour later. It would be available all over the world and at that moment the date in the USA would be the day before. On the defendant's submission this would be prior art because it is to be regarded as having taken place before the priority date. I do not agree.

Moreover Unwired Planet is correct that the EPC accepts that a disclosure on the same day as the priority date albeit earlier in time is not prior art. Art 54(2) refers to disclosures before the priority date, not on it."

The judge also provided a useful table illustrating the times events occurred in the time zones considered in the present case:

  CET (GMT +1) GMT EST (GMT - 5) Hawaii (GMT - 10)
Ericsson Doc uploaded to ETSI server 8 Jan 08:36 8 Jan 07:36 8 Jan 02:36 7 Jan 21:36
Ericsson Doc downloaded by Mr Lieshout 8 Jan 09:45 8 Jan 08:45 8 Jan 03:45 7 Jan 22:45
Priority Doc filed at USPTO 8 Jan 22:59 8 Jan 21:59 8 Jan 16:59 8 Jan 11:59

Inventive step

On the law regarding inventive step, Birss J cited the Court of Appeal's structured approach to the assessment of obviousness in Pozzoli v BDMO and Kitchin J's statement of the law in Generic v Lundbeck [2007]RPC 32 (approved by the House of Lords in Conor v Angiotech [2008] UKHL 49).

Of more relevance in the present case was the role of secondary evidence in the assessment of obviousness. The judge said that while secondary evidence had a role to play, he had firmly in mind the need to keep such evidence in its place (Molnlyke v P&G [1994] RPC 49 and Schlumberger v EMGS [2010] RPC 33).

The defendants relied upon three prior art documents.

The Motorola TDoc

Birss J noted that as compared to claim 1, the Motorola TDoc disclosed the idea of a poll trigger based on a byte counter but did not propose counting PDUs as well. The step between this and the claim is to have a second poll trigger which counts PDUs alongside the byte counter.

Huawei submitted that the Motorola TDoc taught the use of a TTI counter, which is an approximation to a PDU counter and in some circumstances is the same, if one PDU is sent in every TTI. The difference between this and the claim, submitted Huawei, was minimal.

Unwired Planet's expert witness, Dr Cooper, agreed that it was a "perfectly plausible train of thought" to use two counters, one of which was a PDU counter.

Unwired Planet submitted that the fact a train of thought is plausible is not enough to establish obviousness. Birss J declined to comment on this.

Unwired Planet contended that, based on what actually happened, the step was not obvious. The evidence showed that over a short period of time (months), the debate on LTE was at its heart a technical one involving intense effort and focus by engineers from numerous leading firms in the field including NTT, Motorola, Samsung, Ericsson and Huawei. None of the skilled people at the time appeared to spot the idea in the Motorola TDoc. When all the evidence was considered, this secondary evidence proved decisive.

It is worth perhaps noting the judge's observations of the context in which the skilled person would have been operating:

"This invention is concerned with the definition of how entities in a mobile telecommunications system should behave. Defining these rules is precisely the task being undertaken in the standardisation process by the members of the relevant committee. To contemplate how a skilled person would think outside a standardisation process is unreal..."

Also, in cross-examination, Huawei's expert, Mr Wickins, agreed that the step contended by Unwired Planet to be inventive was "a particular milestone in the process of evolving the standard".

The draft LTE standard 3GPP TS 36.322 V.8.0.0

While the draft LTE standard 3GPP TS 36.322 V.8.0.0 was a separate prior art citation, Huawei's case over the document was very similar to its case over the Motorola TDoc, and failed too.

Samsung TDoc

Birss J concluded that in the end, the argument over the Samsung TDoc was not materially different from the argument over the Motorola TDoc, and what happened in the standard setting process was just as relevant to the one as to the other. So this challenge failed too.


On the assessment of inventive step, the decisive role of secondary evidence of non-obviousness in this case is noteworthy.

The time zone point is also interesting. Birss J's view would appear to interpret the existing legislation in the way that would present the lesser of two evils on extreme facts. However, there remains scope for apparent injustice where an invention is disclosed in a jurisdiction in an eastern time zone early in the morning. For example, if you disclosed an invention in Lahore at 12:01 on Day 1 it would be 00:01 at the USPTO on Day 1. A nefarious person would be able to take the disclosure made in Lahore and file a priority document covering the invention at the USPTO at any point on Day 1 per EST. The disclosure that took place (earlier) in Lahore would not anticipate the US application because it was made on the same date. Of course, there may well be other reasons to challenge the filing (!).

The point of most interest in this case, however, is that the UK courts have upheld validity, infringement and essentiality of a SEP arising from an acquired portfolio.

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