The Research Of Multicast Error Correction Scheme In Ad Hoc Network

With the rapid development of wireless network technology, wireless users have no longer be satisfied with simple data communication. Strict delay, error rate limits and real-time multicast service demand is rapidly increasing. Research on stable and reliable real-time multicast has been a big challenge. Transporting multicast datas rapidly and accurately is the most important purpose of multicast error correction schemes in ad hoc network. The research in this paper focuses on MAC layer multicast error correction schemes and multicast routing protocols in ad hoc network in order to reduce the multicast delay and to increase the multicast error correction rate. The main works are as follows:1) In this paper, advantages and problems of existing MAC layer multicast error correction schemes in ad hoc network are analyzed, and give the describe of the MAODV multicast routing protocol in detail.2) Then an improvement named MMW of MAC layer multicast error correction scheme in ad hoc network based on BMW is presented. It reduces the correction delay in BMW by improving the members list, using retransmission request frame and eiminating unnecessary data retransmission.3) MAODV_SD is presented by improving the routing strategy in MAODV. The path with better signal quality and less hops is selected as the multicast routing to reduce multicast delay.4) Relevant error correction schemes and multicast routing protocols are implemented in the OPNET simulation environment. We give comparison of the multicast delay and packet loss rate with strict delay constraints in different situations. Simulation results show that the improved scheme can effectively reduce the multicast delay and packet loss rate with strict delay constraints.It is very good for the upper layer real-time multicast applications.