Conversant Wireless Licensing SARL v Huawei Technologies Co. Ltd & Ors

In patent validity proceedings, a claim must be assessed according to its construction and the disclosure of the prior art, without importing the invention’s core idea into words which do not contain it. A fixed allocation means a positive allocation of resources to a logical channel; it does not itself require control information to be omitted. Obviousness must be assessed against the skilled person’s common general knowledge. A highly general objective of reducing signalling overhead does not establish that a specific overhead problem was common general knowledge or make its solution obvious. A claim may be wider than the priority disclosure and lose priority where it covers a materially different invention. Post-grant added matter and support objections must be analysed separately. Some claims were anticipated by Bestak, while claims directed to retransmission handling and higher-layer HARQ signalling were novel and inventive.

Conversant brought a patent action concerning three UK patents relating to fixed or semi-persistent allocation of telecommunications resources and reduced control signalling in UMTS and LTE systems. The patents were challenged on priority, novelty, inventive step, added matter, support and essentiality grounds. The principal prior art was the Bestak thesis, which described periodic allocation and reuse of control information for streaming services.

The court considered whether the claims covered LTE semi-persistent scheduling, whether the 206 patent was entitled to priority, and whether the relevant claims were anticipated or obvious over Bestak. It also considered post-grant amendments and the essentiality of surviving claims.

1. Priority. The priority document disclosed only a fixed-time allocation in which the mobile knew when to expect data and what transport format to use. Claim 1 of the 206 patent also covered cases where timing was not fixed. That materially wider scope related to a different concept, so the claim was not entitled to priority and the patent was invalid.
2. Construction. “Fixed allocation” referred to a positive allocation of resources, including transmission parameters and optionally timing, to a logical channel. It did not, without more, require control information to be omitted. Claims 18 and 19 were nevertheless anticipated by Bestak. Claim 20 required the mobile to interpret an indication so as to store parameters for first transmissions but not retransmissions.
3. Novelty and inventive step. Bestak disclosed the fixed and normal allocation streams, including their coexistence for the same mobile, and disclosed a tangible per-packet indication to store control information. Claims 18 and 19 of the 177 patent, and claims 1 and 2 of the 722 patent, therefore lacked novelty. Claims 20 and 35 of the 177 patent, and claims 3, 13 and 14 of the 722 patent, were novel.
4. Applying the Pozzoli approach, the skilled team would not, without hindsight, identify a VOIP overhead problem from Bestak. The problem was not common general knowledge. Although the team might adopt Bestak’s periodic allocation, it would not be obvious without the omitted-control-information concept to introduce the tangible indication required by claim 20 or to replace existing HS-SCCH signalling with higher-layer signalling of HARQ process IDs as required by claim 35.
5. Added matter and support. The objections to the relevant amended features and claims were rejected. A claim may be wider than the disclosure without adding matter where it does not disclose new information; support is a distinct requirement and is not a post-grant validity objection to an unamended granted claim.
6. Essentiality. Claims 20 and 35 of the 177 patent, and claims 3 and 13 of the 722 patent, were essential to LTE SPS. Claim 14 of the 722 patent was not essential because SPS stored control parameters for future use before the applicable HARQ process ID was determined. The 206 patent would have been essential to HS-SCCH-less operation if valid.
7. The relevant claims were determined as follows: claims 19 and 18 of the 177 patent and claims 2 and 1 of the 722 patent were invalid for lack of novelty; claims 20 and 35 of the 177 patent and claims 3, 13 and 14 of the 722 patent were valid; the 206 patent was invalid and was to be revoked. Conversant was the overall successful party.