Analysis And Research On OLSR Protocol For Multi-Channel Assignment Of Wireless Mesh Network

With the development of the information society,wireless network technology has become a hot topic.The wireless mesh network is the next generation of the wireless network in the new wireless networking technology.Wireless mesh network is known for solving the "last mile"problem,which is characterized by high robustness and self-healing,but the capacity problem of wireless mesh network makes the network effect unsatisfactory,which greatly restricts the development of wireless Mesh network.To solve this problem,a multi-interface multi-channel routing protocol was proposed in this paper.In view of the abundant channel resources in the network,the multi-channel allocation OLSR protocol is studied to maximize the network quality of wireless mesh network on the basis of multi-interface multi-channel OLSR protocol.In the wireless mesh network,the higher utilization protocol is the OLSR protocol,which is the routing protocol to optimize the link state.The protocol is characterized by the optimization of the link through the MPR selection mechanism.As the research object in this paper,the OLSR protocol will be extended in the aspect of multi-interface multi-channel,then make channel assignment on this basis.Firstly,in order to implement the multi-interface multi-channel expansion of OLSR protocol in NS2,it is necessary to modify the NS2's mobile node model,add the link layer and the physical layer components of the NS2 to make that each interface on the node has a set of Independent components of link layer and the physical layer,the messages transmission between different interfaces do not interfere with each other.Secondly,making multi-interface multi-channel assignment of OLSR on the basis of multi-interface multi-channel OLSR protocol.In this paper,the multi-channel assignment algorithm of OLSR protocol is mainly through the channel assignment algorithm of distributed consultation mechanism.The implementation of the algorithm is mainly through the channel utilization on each interface of the node,whether there is a free interface and the interface usage with the neighbor node to negotiate with the neighbor node of the node whether to carry out channel switching.When the node and the neighbor node both have channel switching requirements,and the network has a free channel which can meet the channel switching conditions,then the node and the neighbor node can perform channel switching action,improve network performance through the channel allocation.Finally,modify the NS2 to make it can simulate the multi-interface multi-channel OLSR protocol.Make channel allocation simulation in multi-interface multi-channel OLSR protocol and get the comparison results between the single channel OLSR protocol and the multi channel OLSR protocol,the comparison results between the multi channel OLSR protocol and the multi channel allocation OLSR protocol as well as the comparison results of channel assignment under different network size.The experimental data show that:Compared with single-channel OLSR prcotocol,the multi-interface OLSR protocol has higher throughput,shorter end-to-end delay time,lower packet loss rate and less jitter.Compared to the multi-intcerface multi-channell OLSR protocol,the OLSR protocol of multi-interface multi-channel allocation has higher throughput and less jitter.The channel allocation can better improve the network quality when the network size is larger.