TQ Delta, LLC v ZYXEL Communications Ltd & Anor [2019] EWHC 562
The Claimant, TQ Delta, was the proprietor of two patents relating to Digital Subscriber Line (“DSL”) broadband internet technology. EP (UK) 1 453 268 concerned a method for controlling the proportion of transmission bandwidth occupied by overhead data. EP (UK) 1 792 430 was directed at ensuring that DSL lines report detected errors in a consistent manner.
TQ Delta asserted that the patents were each essential to various DSL standards, including ADSL2, ADSL2+, and VDSL2+. It commenced infringement proceedings against the Defendants, ZyXEL, in late 2017, seeking relief including declarations as to Reasonable And Non-Discriminatory (“RAND”) terms upon which it could be obliged to licence ZyXEL.
Following a trial of the technical issues in January and February 2019, Henry Carr J revoked EP 1 729 430 for obviousness but found EP (UK) 1 453 268 to be valid and essential to the standards concerned. The ‘268 Patent expires in June 2019.
Iain Purvis QC, Brian Nicholson, and David Ivison appeared for ZyXEL, instructed by Pinsent Masons LLP.