An Opportunistic Network Coding Algorithm Based on the Queue State and Network Topology

Network coding is an emerging and powerful solution that can significantly improve the throughput and power efficiency of wireless networks by allowing mixing of various traffic flows into a single packet. However, when network coding is applied, a packet will have to wait to be network-coded with others, which may result on large delay and packet-loss rate. It will bring negative influence to the application of network coding in real-time video transmission. To overcome the large delay by forcing to use network coding, a novel opportunistic network coding algorithm is proposed in this paper based on the queue state of node´s buffer and the topology of the wireless network (BQST-ONC). Besides, in order to analyze the performance of the algorithm, the Packet Delivery Delay (PDD) is calculated based on a discrete Markov Chain Model, by which the optimal coding opportunity can be obtained. Simulation results show the correctness and effectiveness of the method.