PurpleVine Successfully Assists Client in Invalidating Sisvel US Patent


The United States Court of Appeals for the Federal Circuit (Federal Circuit) recently issued a judgment on the appeal in the invalidity case concerning Sisvel’s U.S. patent US8971279 (referred to as the ‘279 patent). The Federal Circuit affirmed the ruling of the U.S. Patent and Trademark Office, declaring the ‘279 patent (No. IPR2021-00678) invalid. Furthermore, the court once again affirmed PurpleVine’s argument, made on behalf of its client, challenging the patent involved in the case as invalid. PurpleVine IP and PV Law jointly represented the client in filing a U.S. inter parte review proceeding (IPR) concerning the validity of the aforementioned patent, effectively blocking the patent infringement case initiated by Sisvel based on the patent. 

The ‘279 patent in question, entitled "Method and Apparatus for Indicating Deactivation of Semi-Persistent Scheduling," is owned by the well-known patent holder Sisvel. PurpleVine's client sought to challenge the validity of this patent, which stands as one of the most fiercely contested patents litigated by Sisvel in recent years. 

In this matter, PurpleVine's International Litigation and Dispute Resolution team took full responsibility for liaising with the client, in-house technical experts, and U.S. attorneys, as well as drafting and reviewing legal documents. They provided comprehensive case management, strategic counseling, and facilitated communication between the parties in China and the U.S., overcoming time zone barriers. A critical aspect of a successful IPR lies in the identification of accurate evidence of prior art, which necessitates significant investment in thorough and early research of prior art. Through the meticulous prior art search conducted by PurpleVine's standards technical team, relevant prior art references were identified, enabling the filing of the petition. Ultimately, the Federal Circuit accepted PurpleVine's argument regarding obviousness and invalidated the ‘279 patent. PurpleVine's proprietary and efficient case management model, coupled with its specialized standards technical team, played a pivotal role in securing victory in the invalidation case, earning high praise from both its client and partner firm, PV Law. 

About PurpleVine IP

PurpleVine IP Group, headquartered in Shenzhen, China, is a globally-focused IP service provider dedicated to fostering innovation, collaboration, and enhancing the value of intellectual property. We offer comprehensive and integrated IP solutions encompassing global prosecution, analysis & consultation, investment, transactions, licensing, enforcement, and dispute resolution. Our core members of the PurpleVine Litigation and Dispute Resolution Team hail from top-tier law firms and elite corporate legal teams worldwide, bringing extensive experience in handling patent litigation and invalidation cases across more than 50 courts globally. Additionally, our team includes standard technology experts from the communications industry who have been involved in numerous patent licensing negotiations and litigation cases.