Improvement of Wireless Multicast Routing with Energy-Efficiency Based on ODMRP

Mobile ad hoc network (MANET) is temporarily constructed network with no fixed infrastructure. ODMRP (On-Demand Multicast Routing Protocol) is a popular multicast protocol for wireless ad hoc networks. The strengths of ODMRP are simplicity, high packet delivery ratio, and non-dependency on specific unicast protocols. Owing to performing scoped flooding of packets ODMRP suffers from excessive control overhead and redundant data transmissions when the number of multicast source increases, which simultaneously leads to increasing network load and waste of the limited resources of the nodes. In order to cope with the problems, we propose an improved ad hoc multicast routing protocol based on ODMRP referred to as IODMRP. In IODMRP, it is not all the nodes but partial nodes in forwarding group that relay packets, the partial ones are dynamic and chosen based on the forwarder's density and power state. Through a course of simulation experiments, the performance of IODMRP is compared to ODMRP, The simulation results show that IODMRP reduces the redundant data transmissions, enhances the transmission efficiency and extend the network lifetime, the performance of the network is improved.