Handover Detection and Fast Recovery over Satellite Networks for WebRTC
Xiangyu Li, Guixian Wang · 2022
Audio and video applications based on real-time communication (RTC) technology have gained popularity in recent years. The most widely used RTC use case is WebRTC. For instance, Google has adopted a specified congestion control (GCC) protocol stack for WebRTC applications for meeting the high-resolution and low user-perceived latency requirements. In this paper, we first carry out a measurement study to understand the performance of GCC in an emulated standard-topology satellite network. We find that GCC overreacts to satellite handover events due to the satellite networks' structural design, resulting in an extended period of video frame stalling. Based on the finding, we propose Sat-GCC, which is an enhanced GCC algorithm to recognize the satellite handover management and adjust the sending rate. Specifically, Sat-GCC uses the prior knowledge of satellite network topology to detect the satellite handover events and intelligently recover the terminal sending rate according to the memorized packet loss information. We implement Sat-GCC on our full-stack emulating testbed. The experimental evaluations imply that Sat-GCC can efficiently adjust the sending rate to carry out a speedy recovery after each satellite handover abnormality.