L4S Congestion Control Algorithm for Interactive Low Latency Applications over 5G

In recent years, applications such as cloud gaming and virtual video conferencing have gained increasing popularity and new applications, such as immersive applications, have emerged that require very low latency in order to guarantee quality of service. Such applications can benefit from using the Low Latency, Low Loss, Scalable Throughput (L4S) specification that is currently being defined by the IETF. This paper presents a congestion control algorithm aiming at achieving a target latency over a 5G connection, which together with L4S can be used in delay-critical applications. The described algorithm has been implemented into WebRTC and uses ECN marking to adapt its sending rate. The developed algorithm has been compared to the Google Congestion Control (GCC) as a baseline on various data rate patterns and shown to be more responsive to throughput variations more successfully avoiding latency spikes that surpass the acceptable latency.