Research On Routing Algorithm Based On Effective Bandwidth In Cognitive Wireless Mesh Networks

As a new type network, cognitive wireless mesh network combines the technology of cognitive radio and the network mode of wireless mesh network. Because cognitive wireless mesh network inherits the advantage of fault tolerant ability, easily architecture and high bandwidth in wireless mesh networks, and has the ability to solve spectrum resource scarcity and low utilization in authorized wireless spectrum by using cognitive radio technology, it becomes the hot shot in wireless communication industry. In this new type network, available spectrum of cognitive users present dynamic characteristics with the change of time and space, it directly leads to the network topology is time-varying, so different from traditional wired and wireless network, cognitive wireless mesh network faces a great challenge in routing aspect.Aimed at the dynamics of the spectrum of the cognitive radio mesh network and the time dependence characteristics of the network topology, this paper has considered the behavior of the authorized users occupying the spectrum from the new point of view and presents a routing algorithm based on the effective bandwidths in the cognitive radio mesh network with the goal of maximizing the effective bandwidth and employing the cross-layer design method, which can let the routing layer get the spectrum information of the MAC layer in time and make accurate routing selection under the precondition of having no effect of the authorized users and taking full account of the allocation of the frequency spectrum at the same time. Four modules are included in this algorithm:neighbors found and information interaction, path selection, channel and interface allocation, and routing scheduling. Aimed at neighbors found and information interaction module, common control channel is adopted to achieve information interaction and network consultation operation. Aimed at path selection module, a novel path selection algorithm based on maximum available effective bandwidth is designed. It can choose a transmission path with high bandwidth, low resource utilization and high stability. And it is quite good at avoiding choosing congestion link. Aimed at channel and interface allocation module, a channel and interface allocation algorithm is designed, which can make the path to obtain high bandwidth and guarantee the network high connectivity and low interference in full consideration of the utilization of spectrum resource to maximize. Aimed at routing scheduling module, a minimization scheduling algorithm is proposed with the fairness goal, which can avoid date flow starve to death or long waiting time by scheduling network key nodes or local deaf network.Finally, the performance of the routing algorithm in this paper is verified by simulation experiments. A series of experimental results show that the algorithm can select a path with high bandwidth, gain higher network throughput, and has a lower total waiting time and higher scheduling fairness, which is very suitable to dynamic cognitive wireless mesh network.