Delivering Low Latency Video using TCP with Network Coding over Wireless Network

Abstract

Network coding (NC) techniques for lossy wireless networks have been used for fault-tolerant and timely delivery of streaming video data. Recent research on inter-session NC notwithstanding, reliable transmission of high quality media over wireless networks continues to be a challenge. The effects of traffic and network dynamics on coding block size and thereby on latency added at playback were studied, and the interaction of congestion control on the coding technique to remedy this were examined. Simulations show an inherent latency in video playback when TCP with random linear NC is employed as the receiver needs to wait for a certain number of packets to arrive before they are decoded. This paper presents an adaptive NC algorithm based on the nature of video streaming traffic and the available transmission opportunity to improve streaming performance with lower latency and reduced jitter in case of streaming TCP traffic. This algorithm is constructed under the constraint of available transmission opportunities and arriving traffic. The simulation results corroborate that the proposed adaptive NC algorithm reduces observed latency at playback by more than 90% over traditional TCP and more than 60% over simple NC technique. Additionally, the observed jitter reduced by 70% over only TCP and about 60% over fixed bucket size NC. To demonstrate the utility of our approach, the proposed algorithm was compared with TCP’s performance for a real-world video trace. Results from this experiment indicated an 80% reduction in end-to-end latency.