| How to ensure cognitive wireless mesh network capacity while meeting the QoS requirements of different users has been being a popular topic in the wireless communication research field. The topic which this article has chosen is based on the related topics from the National Natural Science Foundation; and is significantly important at theoretical and experimental level.This article combines Cognitive Radio technology and wireless Mesh network architecture with multi-radio, multi-channel and study its QoS performance. A cross-layer QoS protection is achieved through channel assignment based on perception cycle and dual-mode MAC protocol. The common control channel and the perception modules are added in routing layer. And the channel assignment is separate from routing. In every perception cycle, the best channel is chosen for transmission according to channel quality array. The channel quality array is computed by the frequency of primary user activities, the robustness of the link and so on. In the MAC layer, according to the characteristics and needs of data flow, the basic mode or the fast mode can be switch. It can reduce the channel delay for consultation and competition. The simulation results show the improvements of the system in throughput, packet loss rate and the delay.This article first studies the concepts of the QoS performance and the service model based on the multi-channel cognitive mesh network. Then the article analysis the QoS issues in multi-channel mesh network, cognitive wireless network and cross-layer network. Furthermore, the article studies the structure of multi-channel cognitive mesh network design and analysis the system applications. Finally, the QoS protection scheme in multi-channel cognitive mesh network is implemented through two functions:One is the channel assignment based on perception cycle. The other is the dual-mode MAC protocol. The simulation results strongly proves that the better performances in throughput, packet loss rate and the delay. |
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