Research On Routing Protocol For Wireless Mesh Networks

As a new broadband wireless access system, Wireless Mesh Networks (WMN) possesses the merits of WLAN and Wireless Ad Hoc networks. Wireless Mesh Networks have a great future for application. Nowadays, research on WMN is very popular over the world. Wireless routing protocol, as one of its key technologies, performs great function on the optimization of network performance. So the topic of this thesis is wireless routing protocol.Based on the analysis of the existing routing protocols for WMN, this thesis is focused on single-radio multi-channel routing protocol. Adoption of multi-channel can increase the network throughput and data rate, and single-radio is for the consideration of cost and backward compatibility.Firstly, the analysis of Multi-Channel routing protocol (MCRP) is done. In multi-channel networks, nodes can be on different channels while node with a single radio can only be on one channel at any time. Thus, the scheme for the nodes to exchange control messages can directly effect network connectivity. The existing resolution is to broadcast control messages on all channels, which introduces frequent channel-switching and communication blind problems. At the same time, load-balance between different channels is also a fatal problem to be considered.Secondly, for the problems illustrated above, this thesis proposed Evolved Single-Radio Multi-Channel Routing Protocol (ESRMCRP). A scheme of synchronized beacon is introduced for node on different channels to communicate control messages. According to this scheme, time is divided into periodical beacons comprising of a channel-negotiation window and a data window. During the channel-selection window, all nodes tune to a common channel to send/listen control messages, while during data window, nodes communicate on the negotiated channel. For the problem of channel load-balance, information of links along a path is collected during the transmission of RREQ, and the final judge is based on link information and path delay both. Scheme of MRREQ/MRREP is introduced for the dynamic topology of WMN. Nodes in communication periodically launch route-discovery to find the candidate routes and cache them in case of future needs.Finally, process model and wireless node model is developed on OPNET Modeler 10.0, and then network simulation and performance analysis are also done. The simulation results show that under the ESRMCRP network throughput can be greatly increased.