Unwired Planet International Ltd v Huawei Technologies Co Ltd & Ors

Patent claims are construed according to the meaning which a skilled person would give them in context. General claim language is not narrowed merely because the common general knowledge or a particular embodiment uses a more specific implementation. A claim covering counting transmitted units and bytes may therefore include counting initial transmissions only, counting payload bytes only, and counting during assembly. A claim requiring both counters to reset when either threshold is reached is not avoided by additional resets for other reasons.

For priority, the claimed subject matter must be clearly and unambiguously derivable from the priority document as a whole, with the scope commensurate with its technical contribution. For public prior art, the relevant temporal comparison is made by reference to the time zone of the patent office at which the priority document was filed. Obviousness requires assessment of all relevant circumstances, including the realities of the standardisation process.

Unwired Planet alleged that Huawei and Samsung infringed claims 1 and 9 of EP (UK) 2 229 744, a patent concerning polling in LTE radio-link control systems. The defendants argued that the claims, properly construed, either were not infringed or lacked priority, novelty or inventive step.

The principal issues concerned whether the claims covered counting retransmissions or only initial transmissions, counting payload bytes, counting and polling upon assembly, and additional resets. The court also considered whether an internet document uploaded before the priority date formed part of the state of the art, and whether the claims were obvious over three LTE development documents.

1. Construction. Claim 1 was expressed in general terms. It covered counting initial transmissions only or initial transmissions together with retransmissions; counting payload bytes, or payload and header bytes; and counting and setting the poll upon assembly of the transmitted PDU. The pseudocode did not impose a sequence of steps. Claim 9 required both counters to reset when either threshold was reached, but did not exclude further resets for other reasons.
2. Infringement. The relevant LTE standard required counting transmitted PDUs and payload bytes, counting transmissions rather than retransmissions, and setting the poll during assembly. It therefore fell within claims 1 and 9 and infringed them.
3. Priority. Under section 5(2) of the Patents Act 1977 and article 87(1) EPC, the claims were clearly and unambiguously derivable from the priority document as a whole. Their wider scope was commensurate with the technical contribution disclosed. Claims 1 and 9 retained priority.
4. Novelty. The Ericsson TDoc was enabling, but was not made available before the priority date. The relevant frame of reference was Eastern Standard Time at the USPTO, where the priority document was filed. Its availability on 8 January 2008 EST was therefore too late.
5. Inventive step. Applying the structured approach in Pozzoli v BDMO, claim 1 was not obvious over the Motorola TDoc, the draft LTE standard or the Samsung TDoc. The standardisation evidence showed a multifactorial problem, a preference for simpler or window-based mechanisms, and no proposal of the claimed combination of two counters. Claim 9 was also not obvious. The patent was valid and infringed.