Specialist chapter: Key challenges in licensing EVS patents in China and strategic considerations for litigating them

Specialist chapter: Key challenges in licensing EVS patents in China and strategic considerations for litigating them

This is an Insight article, written by a selected contributor as part of IAM's co-published content. Read more on Insight

Enhanced Voice Services (EVS), a super-wideband speech and audio codec standardised by 3GPP, is integral to advanced communication technologies, notably Voice over LTE (VoLTE) and Voice over New Radio (VoNR). As EVS adoption expands globally, patent licensing and litigation have become increasingly complex, especially in strategic markets such as China. Unlike baseband cellular technologies covered by traditional 4G and 5G SEPs, EVS operates independently at the application layer, necessitating distinct licensing practices and separate litigation approaches. This article analyses global EVS litigation trends, examines unique challenges within China’s legal framework, and proposes strategic pathways for effective licensing and enforcement.

The global EVS licensing and litigation landscape and the strategic role of Chinese courts

‘Two Chinese SEP injunctions in VoiceAge EVS v HMD implementer failed to comply with FRAND’[1]

Enhanced Voice Services (EVS) is an advanced speech and audio codec standardized by 3rd Generation Partnership Project (3GPP) in 2014, designed specifically to deliver superior performance in modern voice communication systems.[5] As the first 3GPP codec to support audio bandwidths up to 20kHz, EVS enables full-spectrum voice quality across narrowband, wideband, super-wideband and full band modes, operating efficiently over bit rates ranging from 5.9kbit/s to 128kbit/s.[6] Technically, EVS offers low latency, high compression efficiency, robustness against packet loss and jitter, and backward compatibility with AMR-WB, making it exceptionally resilient in variable network environments.[7] These features contribute to significantly improved voice and audio quality, particularly over LTE and 5G networks.