Anti–Suit Injunction, as a long–standing procedural mechanism, has grown in popularity in SEP disputes during the past decade and has been widely adopted in SEP extraterritorial litigations. In the beginning, ASIs were more likely deployed as a countermeasure to tackle overlapping jurisdiction issues, intending to inhibit the counterparty from starting or resuming legal action in the parallel jurisdiction. As the floodgate of global FRAND rate–setting opened by the English courts, litigants are more likely to use ASIs to chase for their preferable forum to swiftly set global FRAND royalty rates meanwhile impeding the opposing party from commencing or continuing proceedings elsewhere.

This paper adopted the comparative research approach intertwisted with case–law study methodology to explore the present–day trends and new challenges in SEP litigations when national courts are more frequently inclined to deploy Anti–Suit Injunctions to maintain their ambition of setting global FRAND rate as well as to safeguard their judicial sovereignty. The final purpose is to present readers with a comprehensive picture of ASI’s new evolvements and conundrums in the SEP litigation context, and therefore, to lay out some rudimentary thoughts on finding the realistic solutions for the out–of–control escalation.