Research Ad Hoc Network Routing Protocols Mixing QoS

Ad Hoc network is a kind of temporary multi-hop network without any infrastructure, which consists of multiple mobile nodes. As it’s easy to deployment and distributed, it has been widely used in many fields. With the development of multimedia and other services, to provide quality of service in Ad Hoc network has become a hotspot in the area of wireless communications.Because of the complexity of multimedia service, multiple QoS parameters should be considered during the design of routing protocol, howerer multiple parameters constrained QoS routing discovery is NP-Complete problem. This dissertation generates multiple parameters into the path cioncidence from the perspective of the distribution characteristics of them and find path with max path coincidence. Meanwhile it also analyzes the advantages and disadvantages of single-path and multi-path routing protocol and then proposes the dynamic multipath routing strategy. Combination of the above two points, on the basis of AODV protocol, the DMQ-AODV(Dynamic Multipath QoS AODV) routing protocol is proposed. NS2simulator is used in this dissertation to simulate, DMQ-AODV reduces the average end to end delay and the route discovery frequency while increases the packet delivery ratio. compared to AODV protocolIn the DMQ-AODV protocol, RREQ packet has been forwarded flooding. To reduce the forwarding number, many scholars put forward using hybrid routing protocol. This dissertation combines with the MultiPoint Relay mechanism of OLSR protocol. Traditional MPR selection algorithm exists deficiencies, so this dissertation uses the fluctuation of signal strength to select relatively stable node as MPR node. During the route maintenance, the signal strength is used to estimate the link status between nodes and to fix the route in advance when the link will be broken, seamlessly switch route to ensure the stability. Combination of these two points, on the basis of DMQ-AODV protocol, HQ-AODV(Hybrid QoS AODV) routing protocol has been proposed. The simulation shows, HQ-AODV reduces the average end to delay and control overhead meanwhile improves packet delivery ratio compared to DMQ-AODV protocol.