Research And Improve On Multicast Routing Protocols Based ABBM

Ad hoc network is a kind of special wireless network in which no base stations are supported, consisting of a set of mobile hosts that play the role of both host and router, may communicate with one another through multi-hop and roam around at their will. In a word, the specialty of the Ad hoc network makes its routing more complex than other networks. Traditional internet multicast routing protocols can't meet the quickly-changing of the network topology, so designing the new multicast routing protocols which are suitable for Ad hoc network is hotspot.The paper sorts the existing multicast routing protocols in Ad hoc network into different types, and compares, analyzes, illuminates the content of different types of protocols, especially analyses ABBM (Adaptive Backbone-based Multicast routing protocol), which is advanced than the other. By analyze routing mechanism in ABBM, discovered that it has limitations in the scalability of multicast protocol and cluster stability. Then design the enhance scheme of ABBM: E-ABBM.Firstly, scheme of WCA (Weighted Clustering Algorithm) in ABBM is improved. Modify the average speed of node which is the weight-parameter of WCA to the average relatively speed among nodes for improving the stability of cluster, design the new clustering algorithm for the large scale Ad hoc networks router.Secondly, import the hybrid of reactive and proactive routing scheme. Use proactive routing scheme within cluster and reactive routing scheme among clusters.Finally, the different protocols including E-ABBM and ABBM are simu- lated on platform of the NS (Network Simulation). By the results of simulation,concluded that E-ABBM has better performance as packet delivery ratio and network delay and expansibility.