Unwired Planet International Ltd v Huawei Technologies Co Ltd & Ors

A patent claim is entitled to priority when its subject matter, as a matter of substance, is directly and unambiguously derivable from the priority document as a whole, read through the skilled person's common general knowledge. The document need not disclose every embodiment falling within the claim.

Obviousness requires a multifactorial evaluation without hindsight. Contemporary conduct in the relevant technical field may provide useful secondary evidence.

For novelty under article 54(2) of the European Patent Convention, the priority date is the 24-hour day in the time zone of the filing office. A publication forms part of the state of the art only if it occurred before that period began.

Unwired Planet owned a patent concerning polling for status reports in a wireless communications network. Huawei appealed against Birss J's refusal to revoke the patent in [2015] EWHC 3366 (Pat).

The appeal raised three issues. The first was whether claims 1 and 9 were entitled to priority despite covering counting and polling when a data unit was assembled for transmission. The second was whether the claims lacked inventive step over a Motorola standards proposal. The third was whether an admittedly novelty-destroying Ericsson proposal had entered the state of the art before the priority date, given that it became available while the previous calendar day still applied in some time zones.

1. Appeal dismissed unanimously. Claims 1 and 9 were entitled to priority, were not shown to be obvious and were not deprived of novelty by the Ericsson publication.

2. A priority inquiry asks whether the claimed invention is directly and unambiguously derivable, as a matter of substance, from the priority document as a whole. The document is read through the skilled person's common general knowledge, and both explicit and implicit disclosure may be considered. The inquiry does not require every embodiment within the claim to have been disclosed. Nor may an obvious development be added to the document's disclosure.

   Here, the conventional understanding was that assembly formed part of transmission and that PDU counting occurred upon assembly. The skilled person would therefore understand the priority document's references to “transmitted” data as encompassing counting and polling upon assembly. Its disclosure also directly and unambiguously conveyed the combined-counter and linked-reset concepts of claims 1 and 9.

3. Obviousness is a multifactorial factual evaluation. Identifying individual components in the prior art with hindsight and showing that they could advantageously be combined does not establish obviousness. The Motorola proposal did not point clearly towards using both a byte counter and a PDU counter. Competing considerations included simplicity, the existing TTI counter and the technical advantages of window-based polling.

   The judge was entitled to use contemporary standards-committee documents as secondary evidence. Although they required caution, they provided a useful connection with the technical work occurring at the priority date. No error of principle justified appellate re-evaluation. Claim 9's linked resetting of both counters was a further step from the Motorola disclosure.

4. Under article 54(2) of the European Patent Convention, the priority date is the complete 24-hour period constituting the filing day in the filing office's time zone. A publication belongs to the state of the art only if it occurred before that period began, measured in the same frame of reference. The Ericsson document was uploaded during the priority day in the USPTO time zone and therefore was not prior art, notwithstanding that the previous date still applied elsewhere.

1. Court of Appeal (Civil Division): The court dismissed Huawei's appeal unanimously on priority, inventive step and novelty: [2017] EWCA Civ 266.
2. High Court, Patents Court: Birss J refused to revoke the patent: [2015] EWHC 3366 (Pat).