Network-Coding Based Multicast Routing in VANET

Multicast can efficiently improve the utilization and scalability of wireless links. Fusion of multicast and network-coding will implement the maximum flow minimum cut value in network, which can increase the network throughput. An event-driven multicast routing algorithm using network-coding, NCMR, is proposed. This algorithm could overcome VANET’s shortcoming of frequently changed topology and short-life links. NCMR algorithm is based on local topology information and combined with location information provided by GPS systems in vehicle. In this algorithm, node determines the data transmission rate and the local network maximum flow minimum cut value, and calculates the minimum field combined with maximum distance separable code (MDS), and then formats the linearly independent characteristics of global coding matrix to guide the downstream node encoding. Aside from guaranteeing the success rate of the target node decoding, this algorithm could also reduce the information transmission size of finite field. In order to guarantee QoS of network, NCMR algorithm will force the nodes switch to opportunistic routing when the network is split. Simulation results show that the NCMR algorithm effectively reduces communication between nodes and avoids communication interference, and could achieve higher reception success rate and finally balance network load.