Sierra Wireless v. Sisvel S.P.A

Authored by: Jeremy J. Gustrowsky

In a recent decision, the Federal Circuit vacated a Patent Trial and Appeal Board (PTAB) ruling that had found several claims of U.S. Patent No. 7,869,396 unpatentable. The patent, owned by Sisvel S.p.A., covers a method for improving data transmission reliability in wireless communication systems. The dispute began when Sierra Wireless, Honeywell, and Telit Cinterion challenged the patent’s validity, arguing that all claims were anticipated or made obvious by an earlier patent application known as Sachs.

A key issue in the case was how to interpret certain steps required by the patent claims. The PTAB had previously decided that some steps in the method were mutually exclusive, meaning only one needed to be present for a prior art reference to anticipate the claim. The Federal Circuit disagreed, finding that the plain language of the patent required both steps to be performed when their conditions are met. This interpretation was crucial, as it meant the prior art cited by the challengers did not fully disclose the patented method.

Another significant aspect of the decision involved the qualifications of Sisvel’s expert witness, Mr. Bates. The PTAB relied heavily on his testimony, but the Federal Circuit noted that Mr. Bates did not have the technical background the Board itself had said was necessary—specifically, a degree in electrical engineering or equivalent experience in designing wireless data transmission systems. The court held that the Board abused its discretion by relying on Mr. Bates’ testimony without making a clear finding that he met the required level of skill in the art.

As a result, the Federal Circuit vacated the PTAB’s decision and sent the case back for further proceedings. The Board will need to reconsider both the interpretation of the patent claims and whether Sisvel’s expert is qualified to offer opinions on technical matters. This case highlights the importance of clear claim interpretation and ensuring that expert witnesses meet the technical standards set by the Board.