Insights High Court finds Interdigital telecoms patent invalid as anticipated by prior art on a particular reading of that prior art


InterDigital Technology Corporation is currently suing Lenovo Group Ltd in relation to five of its standard essential patents (SEPs) claiming inventions in 3G and 4G telecoms technology, which it says Lenovo is infringing through the manufacture and sale of its mobile phone devices.

This judgment relates to the second in a series of trials, the first of which was heard in July 2021. A FRAND trial is also upcoming. This judgment concerned an EP(UK) patent for a feature of Enhanced Uplink, also referred to as High-Speed Uplink Packet Access, or HSUPA, which was said to be essential to the UMTS (3G) standard, release 6 onwards (the Patent).

The case concerned the way in which, in HSUPA, data was assembled for transmission on the physical layer (PHY). Only data blocks of certain pre-determined sizes (called E-TFCs) were allowed to be transmitted. Further, the amounts of data that could be sent on the Enhanced Uplink were controlled. The “useful” data to be sent did not necessarily match an allowed E-TFC, so the system was one in which padding bits were added to ensure the E-TFC was filled. The Patent was concerned with minimising the amount of padding which was sent by adjusting or quantising the amount of data multiplexed into an E-TFC to more closely match the E-TFC size.

Lenovo’s case denying infringement resolved to construction issues. No equivalents arguments were raised by InterDigital, so Mr Justice Mellor undertook a “normal” interpretation of claim 1 of the Patent. Mellor J found that no skilled person would interpret certain expressions in claim 1 literally, as Lenovo argued, as it made no technical sense to do so. Lenovo’s linguistic arguments had no weight against the technical considerations.

The case on validity narrowed to anticipation or obviousness over a single piece of prior art called Filiatrault, which was a marked-up version of 3GPP TS 25.309 v6.2.0 entitled “FDD Enhanced Uplink; Overall Description; Stage 2 (Release 6)” circulated by the editor, Mr Charles Filiatrault, on 27 April 2005 to the members of the RAN WG2 (Radio Access Network Working Group 2) by email to the WG2 email reflector, which makes their contents accessible to the public on the ETSI website.

Lenovo contended that Filiatrault disclosed the invention, but if not, then it said that the Patent was obvious over Filiatrault. InterDigital said that Filiatrault missed the invention completely, so the Patent was neither anticipated nor obvious.

Mellor J dismissed Lenovo’s claims as to obviousness, whether Filiatrault was given the reading attributed to it by Lenovo or by InterDigital.

As for disclosure, however, Mellor J found that, given his findings on a particular point of construction in InterDigital’s favour and giving a particular aspect of Filiatrault the meaning attributed to it by InterDigital, with which Mellor J agreed, Filiatrault had indeed anticipated the invention described in the Patent.

Accordingly, the Patent was invalid, not essential to the standard and Lenovo had not infringed. (Interdigital Technology Corporation v Lenovo Group Ltd [2022] EWHC 10 (Pat) (6 January 2022) — to read the judgment in full, click here).