Probabilistic Network Coding with Priority over Wireless Networks

Network coding can significantly improve the throughput and power efficiency of wireless networks by mixing packets from different flows into a single packet. However, forcing packets to be coded may induce large delay and packet-loss rate which is intolerable to some services such as real-time communications. Considering the diversity of traffic flows and the stochastic nature of the packet arrival process in wireless networks, we propose a Probabilistic Network Coding with Priority (PNCP) method in this paper. PNCP keeps different queues in node buffer for different flows. Whether a packet is transmitted with or without network coding is determined by its priority and the queue state. A Markov Chain Model is formulated to analyze PNCP´s performance in terms of delay and packet loss. The developed theoretical results are also validated through simulations.