Studies On Key Technologies Of Multicast Routing Protocol Based On Publish/Subscribe

Publish/subscribe (pub/sub) system has characteristics of asynchronous and multi-points communication. It decouples the publishers and the subscribers in time, space, and control flow. Publish/subscribe system is suitable for highly dynamic network and data-oriented routing, and it is widely used in large-scale distributed systems. With the usage of mobile portable devices and the extension of distributed systems, the pub/sub system will be implemented in mobile, wireless and highly dynamic environment, such as Ad-hoc network. Because the topology of Ad-hoc network is dynamic and flexible, it is difficult to deploy pub/sub system in Ad-hoc network with the combination of pub/sub system and multicast routing protocol.In recent years, researchers have proposed many multicast routing protocols in Ad-hoc network. These protocols can be classified into three types. The first type is tree-based multicast routing protocols, which uses the idea of tree-based multicast protocol in fixed network, such as ADMR and MAODV. It establishes one path between source and destination. The second type is based on mesh which can provide multiple paths between source and destination, such as ODMRP, CAMP and DRMR. The third type is hybrid.This thesis mainly investigates key technologies of multicast routing protocol based on publish/subscribe. Firstly, the Publish/Subscribe Multihop Routing (PSMR) protocol for wireless Ad-hoc network is designed by combining ADMR and publish/subscribe system. Secondly, PSMR is simulated in NS-2. The result proves that PSMR can reduce the packet forwarding and improve efficient network resource utilization. Thirdly, the thesis compares the performances of PSMR, ADMR, MAODV and ODMRP in the packet delivery ratio, number of control packet transmissions and end-to-end delay. Fourthly, we analyze the predictability of the PSMR network traffic using the method of multifractal based on wavelet and the method of log-infinitely divisible cascades. The analysis results show that the traffic of PSMR has the characteristic of extended self-similarity.