Lenovo Fights To Invalidate InterDigital 4G Patent On Appeal
By Sophia Dourou · Listen to article
Law360, London (December 14, 2022, 6:30 PM GMT) -- Lenovo asked an appeals court Wednesday to find an InterDigital patent for technology used in 4G is invalid, arguing an earlier judge took the wrong approach in deciding whether the invention would be obvious given earlier technical developments.
Counsel for Lenovo told the Court of Appeal that the patent in question — which covers a way to use a non-contention-based channel allocated for use by a single device — failed to state any advantage over prior art and was therefore obvious rather than inventive.
Lenovo's counsel Thomas Hinchliffe KC said the patent, which involves reducing a message to a 1-bit size and transmitting it using an "on-off key," should have been obvious based on prior art, including a technical document submitted by Samsung in a 2005 working group meeting during the development of LTE technology.
Lenovo is appealing a June 2021 High Court ruling that the patent in question was valid and essential, and had been infringed by the Chinese tech giant.
Hinchliffe rejected the suggestion that the patent was not obvious because it used the on-off key technology previously thought to be "impractical" for cellular networks. He stressed that a skilled person would have been aware of any potential problems and tradeoffs involved in using that technology, but it would have been part of his or her common general knowledge.
But Judge Colin Birss, leading the three-judge panel, disputed the assertion that the on-off key would have been "at the forefront" of a skilled person's mind.
"If it was a technique that was part of their toolkit, it was right at the bottom of it, right under a rusty screwdriver," Judge Birss remarked.
Douglas Campbell KC, representing InterDigital, told the court that Lenovo lacked any real legal ground to mount a challenge, and said it was merely attempting to overturn the earlier judge's findings of fact on the on-off key technology. Cambell pointed out that while Lenovo relied heavily on the patent's lack of stated advantage over prior art, it did not dispute that the invention did, in fact, offer an actual advantage.
Campbell said in his written submissions there was nothing in the Samsung document suggesting using the on-off key technology, which remains "the beginning and end" of Lenovo's case as to obviousness. Campbell further accused Lenovo of relying on a partial account of the evidence given by experts over the course of the trial in his appeal.
This appeal is the latest development in a long-running battle between the two technology companies over standard-essential patents used in cellular phones. InterDigital and Lenovo have been in talks since 2009 to license InterDigital's patent portfolio covering 3G and 4G standards, with no success.
In January, Lenovo scored a victory after a judge invalidated a pattern held by InterDigital in the second of five trials. That same month, Lenovo offered to pay its rival a lump sum of $80 million to end the ongoing dispute over fair and reasonable licensing terms for mobile phone patents.
The hearing before Judges Colin Birss, Mark Warby and Sarah Falk is set to continue Thursday.
The patent-in-suit is European Patent (UK) No. 2 485 558.
InterDigital is represented by Douglas Campbell KC and Joe Delaney of Three New Square, instructed by Alex Brodie of Gowling WLG (UK) LLP.
Lenovo is represented by Thomas Hinchliffe KC and Jeremy Heald of Three New Square, instructed by Nicola Dagg of Kirkland & Ellis International LLP.
The case is InterDigital Technology Corporation & Ors v. Lenovo Group Ltd & Ors, case number CA-2021-003431, in the Court of Appeal of England and Wales.
