Understanding the Impact of Cellular RAN-induced Delay on Video Conferencing

Congestion-control algorithms for video-conferencing applications work well in wired networks but are fragile in cellular networks due to high delay variations and variable capacity in these networks. This paper investigates the causes of delay variations in cellular networks using a cross-layer approach. By measuring a WebRTC application over LTE at both the physical and network layers, we identify the effects of such delay inflation caused by physical-layer resource scheduling and link-layer retransmissions.