Study On The Multipath Routing Protocol Based On QoS For Wireless Mesh Networks

Wireless Mesh networks have drawn great attention from many researchcommunities in the past few years. Simultaneously, many kinds of applicationgradually require the support of the reliable transmission for video information stream.Wireless Mesh networks urgently need the guarantee of quality of service (QoS) suchas reliable bandwidth, low end-to-end delay, balanced load and so on. Due to thefeatures of wireless networks, they often interrupt and increase end-to-end delay forvideo transmission services. The single path routing protocols are not suitable for thenetwork application with strict QoS requirements. Compared with the single pathrouting protocol, the multipath routing protocol can provide reliable communication,ensure load balancing and so on. However, multipath routing protocol faces with theproblem of increment delay and unreliability when it transmits video services.According to the disadvantages of real-time and continuity for video services, amultipath routing algorithm based on the guarantee of QoS is proposed, whichimprove the real-time and reliability for video transmission in wireless networks.Firstly, this paper summarizes the research status of actual wireless Meshnetwork, wireless video transmission and multipath routing protocol based on QoS.According to the disadvantages of real-time and continuity for video services inwireless networks, a multipath routing protocol for wireless Mesh networks which cansatisfy QoS requirement (QoS-MPOLSR) is proposed. Firstly, the protocol broadcastsHELLO messages to collect the QoS information, and calculates the link quality bythe priority function. Then through using the improved multipath Dijkstra algorithm(QoS-Dijkstra) for path selection, the protocol can gain the paths from the sourcenode to the other nodes. QoS-MPOLSR is the source routing protocol, and in order toavoid the routing failure in the process of data transmission, routing recovery is alsoproposed.Secondly, this paper designs the Testbed for wireless video transmission, andimplements QoS-MPOLSR deamon in Linux. QoS-MPOLSR based on OLSRdeamon expands the QoS multipath module and netfilter module. In a word, theTestbed can implement the real-time transmission and on-line display for video streamin wireless Mesh networks.Finally, the simulations are performed to evaluate QoS-MPOLSR for wirelessMesh networks. Network Simulation (NS2) and MyEvalvid are used for our simulation to compare the performance of the different routings. The QoS-MPOLSRhas the advantage than the other comparison protocols, especially in reliability andcontinuity. In a word, it can effectively improve the performance of the network andalso be suitable for the multimedia services transmission.