Research On Cooperation Enforcement In Wireless Ad Hoc Networks

The application and development of wireless communication technology and the requirement for valid communication under no fixed networking infrastructure attract the attection on military and civil development of wireless mobile ad hoc networks. Each node in ad hoc networks can move randomly and have the same rank and function. Each node can act both as the router and as the machine. When the node is not in the tranmitting range of the destination, it can ask the intermediate nodes to relay the packets to the destination hop by hop. Even few selfish nodes in ad hoc networks can greatly degrade the performance of the networks, because no cooperation can be assured among the nodes.The cooperation enforcement on the routing and packets forwarding was investigated in the reastic wirelss ad hoc networks under noise. First, the origin, the development, the specification and the application of ad hoc networks are reviewed. Then the analysis of the friability and secure strategy are presented. The selfish behaviours are analyzed. Following, the dissertion further investigated deeply and compared the research state and the existing problem of cooperation enforcenment in the stages of routing and packets forwarding.VCG mechanism is adapted to stimulate the the motivation to participate in the routing selecting and guarantee the truth telling about the cost. But the current mechanisms based on VCG need to broadcast all the path information and the source node or the destination node needs to store all the topology information and compute the shortest and least cost path with the overhead of O ( n2). SPOER is presented to slove the problem of high overhead. SPOER can reduce the overhead to O (n) and the destination node or the source node needs not collect all the topology information and only require the shortest path and the corresponding substituted paths. The storage of the valid paths and computing task are distributed to every node in ad hoc networks which greatly reduces the pressure of storage and computing on the source node or the destination node.Watchdog is used to monitor the behaviour of the neighbours in the packet forwarding stage. The current algorithm which assumes the ideal running environment and did not fully consider the noisy disturbance in real environment, takes the packet dropping due to noise as that caused by the selfish behaviour and have the positive false on the reputation of the nodes and can not provide the right information for path selecting. DRSPD is provided to distinguish the packet dropping misbehaviour with the sporadic transmission errors, can isolate the selfish nodes from ad hoc networks and increased the packets'delivery ratio and nodes'utility. DRSPD can enforce the cooperation in ad hoc networks.In order to stimulate the cooperative motives of the selfish nodes, the need for forwarding packets is related with the provision for others. The model of cooperation enforcement, APFIPN, is built on the fear for the punishment and not the reciprocal. APFIPN relates the payoff for the cooperation with the cost of the punishment for the selfishness and deters the selfish behaviour. The effect of punishment, isolation, successful transmission probability and hops on the cooperation are analyzed and proved by the simulation results.