Railway Wireless Mesh Networks And Optimization Of Multi-hop Transmission Performance

There is an even increasing demand for the onboard Internet access from the passenger train. As deploying the wireless overlay along the railway is one of the necessities for provision of Internet services on passenger train, Wireless Mesh Network (WMN) gives us a new solution for it. However, the performance of WMN is decreasing rapidly as the wireless hops increasing. Because the wireless hops of Railway Wireless Mesh Network (RWMN) are always up to tens and its wireless backbone should take in charge of its users' packets relay, these are dissimilar from those in the traditional WMN, which make it is necessity to solve the multi-hop problem in RWMN.This thesis presented multi-radio Mesh node structure, mixed channel multiplexing scheme, and unbalanced bandwidth allocation mechanism for the RWMN. And then, the multi-hop performances of latency and throughput are analyzed based on these methods. Finally, these proposals are realized utilizing the open source coding based on Linux OS. Then a test bed is constructed and within it, series of experiments for the RWMN are performed. Based on the theoretical analysis and experiment results, the thesis argues that these methods can improve the multi-hop performance for RWMN.Further more, the routing policy of RWMN is analyzed and its packet forwarding procedures are discussed, which is the basis for its algorithm designing.