The Research On Cross Layer Approach Of On-demand Routing Protocol For Wireless Mesh Networks

The Wireless Mesh Networks (WMN) is considered to be "The Wireless Version of Internet". WMN combines the advantages of WLAN and Wireless Ad hoc network. WMN is a special kind of WLAN, and can be considered as one kind of Ad hoc network with low mobility. WMN is reliable, self-organized and self-healable, and it can provide functions like mobile user management and tracing. It is a multi-hop broad bandwidth distributing wireless network with high capacity and high transmission rate.Firstly, the basis of WMN, we introduce the conceptions, architectures, and key technologies. Secondly, making reference to typical wireless self-organizing network, we research deeply into WMN routing protocol, especially on-demand routing protocol. And then necessity and demand on cross-layer design, general principles and methods, key technologies to be deeply researched are summarized in chapter three. Afterword, current MAC and routing cross-layer design schemes are introduced in the part of the thesis.On-demand routing protocol, also called reactive routing protocol, adopt on-demand routing discovery mechanism in which a node searches routing in the network when a packet waits to be sent and the node has not the corresponding routing. On-demand routing mechanism will not do the periodic broadcast of control messages, so the overhead is decreased. But the ETE (End To End) delay of packets will increase. Current CLAODV is a extend version of AODV protocol and it improves the HELLO message mechanism with a cross-layer way. In last part of the thesis, a cross-layer power-controlled routing protocol(PAODV) that needn't the help of geographical position information is designed based on symmetry of channel gain and CLAODV protocol. Through adjusting node's broadcast power and singlecast power, PAODV that saves energy prolongs node working hours. Simulation shows that PAODV not only decreases the ETE delay of packets, but also has good effect on saving power.Finally, the thesis is concluded and the future work is prospected.