Research On QoS For 2P-based Long-distance Wireless Mesh Network

In developing regions of low population density and low-income,traditional network connectivity solutions,such as telephone,cellular,WiMax,satellite ,fiber and so on,can't be used because of high costs.This makes how to deploy networks in low population density and low-income regions become a research hotspot.As prices of single-board computers and 802.11 wireless cards decreased, WiFi-based long distance wireless Mesh networks highlighted the advantage on price.These networks are comprised of point-to-point long distance links that use high-gain directional antennas and provide services for the users in developing regions,such as sending and receiving e-mail,IP phones,distance learning, e-governance etc. One of challenges that long distance wireless Mesh networks faced is the poor performance as using the stock 802.11 protocol.So the protocol that support above a variety of services.In this thesis,the author proposed a protocol ,used 2P protocol as MAC protocol,that meet different requirements of various services.2P is a TDMA-based protocol,including SynTx phase and SynRx phase and can avoid inter-link interference.As long-distance wireless Mesh networks need to support transmission of various traffic,the author used Maximum Allocation with Reservation (MAR)Model to provide significant dynamic protection for the bandwidth of particular streams of traffic.In non-congested network conditions,all services fully share all available bandwidth.when congestion occurs ,it will protect allocation bandwidth for particular streams of traffic. We operate connection admission control on the basis of MAR model for the flow into the network , operate bandwidth reservation for the admitting flow,guatantee the bandwidth demand of QoS traffic and provide a max class-type available bandwidth for every flow into the network.Meanwhile, in order to meet the delay requirement of QoS traffic ,the author proposed a parameterized scheduling algorithm.According to the character that the topology of 2P protocol must be bipartite,the author modified the current tree topology and used multistage graph as topology,increasing the alternate paths between two nodes.The author implemented the configuration of multi-interface nodes and DSR protocol supporting multi-interface. We also implemented above bandwidth allocation algorithm and QoS scheme. Simulation results show that improved scheme can provide dynamic protection for treams of traffic,and can be served within their QoS requirements with different data rates and delay bounds.