The Patent Trial and Appeal Board (PTAB) has invalidated six amended claims in a wireless communications patent owned by the University of New Mexico, following a directive from the Federal Circuit to reassess the case. The PTAB determined that these amended claims were substantially similar to previously disallowed claims.
This development is part of an ongoing legal dispute between network equipment manufacturer ZyXEL Communications Corp. and UNM Rainforest Innovations, the technology transfer arm of the University of New Mexico. The patent in question, U.S. Patent No. 8,265,096, pertains to methods for constructing frame structures in orthogonal frequency-division multiple access (OFDMA) systems.
Initially, ZyXEL challenged claims 1 through 4, 6, and 7 of the ‘096 patent, arguing they were unpatentable due to obviousness. The PTAB agreed, finding these claims obvious over a combination of prior art references. However, the Board did not find claim 8 unpatentable at that time. UNM Rainforest Innovations subsequently filed a motion to amend, seeking to cancel the challenged claims and introduce new substitute claims.
In July 2024, the Federal Circuit reviewed the PTAB’s decisions. The appellate court affirmed the PTAB’s finding that claims 1 through 4, 6, and 7 were unpatentable as obvious. It also reversed the PTAB’s decision regarding claim 8, concluding that it too was obvious in light of prior art. The court remanded the case to the PTAB to determine whether the substitute claims were unpatentable under the doctrine of collateral estoppel, given the invalidation of the original claims. ([ipwatchdog.com](https://ipwatchdog.com/2024/07/22/cafc-invalidates-remaining-claim-data-transmission-patent-remands-substitute-claims-collateral-estoppel-determination/id%3D179164/?utm_source=openai))
On remand, the PTAB evaluated the substitute claims—numbered 44 through 47, 49, and 50—and found them to be substantially similar to the original claims that had been invalidated. Consequently, the Board concluded that these amended claims were also unpatentable.
This case underscores the complexities involved in patent litigation, particularly concerning the amendment of claims during inter partes review proceedings. It also highlights the interplay between the PTAB and the Federal Circuit in determining the patentability of claims and the application of collateral estoppel in such contexts.