The Research Of Opportunistic Routing Protocol Based On Network Coding In Wireless Sensor Networks

Wireless Sensor Networks(WSN)is a hot research field in recent years.As one of the key technologies in WSN,the design of routing protocols has a great impact on the performance of the networks.However,the WSN has its own characteristics,which poses a challenge to the design of routing protocols.Traditional routing protocols for WSN cannot adapt well to the dynamic wireless environment.Opportunistic routing takes advantage of the broadcast nature of the wireless medium,which ensures the reliability of data transmission.At the same time,the opportunistic routing protocols can solve the coordination problem among the candidate forwarding nodes by introducing the network coding.In consideration of the limited energy of wireless sensor networks,an energy-balanced opportunistic routing protocol MMORE(Modified MORE)is proposed.In the MMORE protocol,considering the link quality between nodes and the residual energy and energy consumption of nodes,the ELT(Expected Life Time)metric is put forward to balance energy consumption of nodes.And based on ELT,the forwarding candidate selection algorithm is given,which optimizes the number of nodes in the forwarding candidate set.By doing so,the data packets with minimum cost has been forwarded and the network lifetime has been extended.Simulation results show that,compared with the MORE and MT-NCOR protocols,the MMORE protocol based on ELT metric can effectively balance the energy consumption and prolong the network lifetime.In addition,there is an appearance of redundant forwarding of coded packets in the opportunistic routing protocols based on network coding.We propose an opportunistic routing protocol CCFAOR,which is based on the coding coefficient feedback acknowledgement to reduce the forwarding of redundant data.In the CCFAOR protocol,downstream nodes carry a coded feedback vector when they forward the coded data packets.Through comparison and analysis,upstream nodes decide whether to stop the transmission of the coded data packets or not.Additionally,the cached data packets are marked with the coded feedback vectors to avoid being involved in random linear network coding for many times.Simulation results show that,compared with the MORE and CCACK protocols,the CCFAOR protocol can reduce the transmission of redundant packets and throughput of network has been improved.