| Wireless Mesh Network is the most promising member in the next generation wireless network families which has the potential to substitute wired networks. However, the throughput of Wireless Mesh Network can still hardly meet the quality of service required by the market. The reason of this dilemma is the insufficiency in using the spectrum resource, which is caused by the single channel mode current Wireless Mesh Networks are constructed. However, recent research paid more and more interests on the developing of multi-interface multi-channel Wireless Mesh Networks. Meanwhile, the price of wireless devises was dramatically decreasing as long as the fast developing of wireless technologies. Multi-interface multi-channels devises will occupy the market in the near future. Nevertheless, the improvement of routing protocols has not kept pace with the developing of the market. Single channel routing protocols are the main obstacle in elevating performance of Wireless Mesh Networks since they are not able to use spectrum resource efficiently.This thesis begins with a survey of wireless Mesh networks. As well as the characterizing of multi-channel wireless Mesh networks, the concept of multi-channel routing is discussed, especially the problems of design of routing metrics. As a father improvement, this thesis proposed an improved multi-channel routing metric-WETTP. This new routing metric takes the expected delay of the whole path as the criteria of discarding imperfect paths. Based on WETTP a new multi-channel routing protocol named MC_PASR is designed and implemented.In the end, the performance of MC_PASR and MR_LQSR is compared based on simulations. Four metrics are measured for the comparison: data delivery ratio, median goodput, number of TCP retransmissions and number of MAC layer retransmissions. The results evince that MC_PASR is a more efficient routing protocol with which the goodput increased by 50% and the number of transmissions decrease for 15-20%. |
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