Research On Multipath Routing Protocol In Wireless Mesh Network

Wireless mesh network (WMN) is a new type of network architecture. Because of itsself-organizing, self-configuring, low-cost characteristics, WMN has received extensiveattention in various fields. Multi-radio multi-channel (MRMC) WMN can enhance overallnetwork performance and improve the capacity of the network, which is the future directionof WMN.The routing protocol in WMN determines routing establishment process, which has animportant influence on network performance. Multipath routing protocol can take fulladvantage of the network resources, enhance the fault-tolerant, reduce the overhead andinterference caused by control packets，and achieve load balancing. So research and optimizethe multipath routing protocol in MRMC WMN is important to enhance the performance ofWMN.Existing multipath routing protocols has not captured the interference and loadeffectively, which may route packets to heavy load and heavy interference areas.Furthermore, during the process of transmitting packets, most of existing multipath routingprotocols fail to choose a good path according to network status, which brings in issues likepath information expired and back path switching not timely.For those reasons, this paper studys the multipath routing protocols in MRMC WMN.The main works are as follows:(1) This paper proposes a metric of expected delay (MED). MED innovatively uses theexpected available bandwidth (EAB) to capture the physical interference, logical intra-flowand logical inter-flow interference uniformly, which avoids bringing in adjustable parametersor making the routing design complex.(2) For the issue of existing multipath routing protocols do not captured the interferenceand load effectively, this paper proposes an improved multipath routing protocol based onAd hoc On-demand Multipath Distance Vector (AOMDV), called IAOMDV. IAOMDV usesMED to establish multipath and send packets, which can identify the heave load and heavyinterference areas as it captures the influence of interference and load in the network.Simulation results show that IAOMDV can achieve interference awareness and loadbalancing, which can bypass the congested areas and high-interference region.(3) In order to measure the link quality during the process of transmitting packets better,this paper proposes an improved metric of expected delay (IMED). IMED improves MED bycapturing the actual delay, which can measure the link quality during the process oftransmitting packets.(4) For the issue of existing multipath routing protocols fail to choose a good pathaccording to network status during the process of transmitting packets, this paper proposesan interference and load aware based adaptive multipath routing protocol (ILAM). ILAMuses MED to establish multipath which can use network resource better. During the processof transmitting packets, based on IMED, ILAM combines Q learning and ε greedy algorithm to explore and learn the current network status while ensuring the quality of the network.ILAM adaptively chooses route to transmit packets according to the current network status,which can make full use of network resources and improve network quality. Simulationresults show that compared with IAOMDV, ILAM can use the network resources better,improve the overall network throughout, reduce packet loss ratio, end to end delay and routeoverhead.The results of this study have great significance for studying multipath routingprotocols in WMN.