Multicast Routing Protocol Based On Node Credibility Evaluation In Wireless Ad Hoc Networks

Wireless ad hoc networks originate from military needs.Nodes in the networks can move freely.Each node can act as both terminal receiving device and routing device.Wireless ad hoc network is vulnerable to malicious attacks from outside because of it's openness and dynamic topology.To deal with such attacks,we propose a trust-based multicast routing protocol TMAODV(Trust-based Multicast Ad hoc On-Demand Distance Vector Routing).Our work is as follows:(1)Designing the trustworthiness evaluation model of nodes.We calculate the comprehensive trustworthiness of nodes through the direct and indirect trustworthiness values of nodes.The Bayesian model and the beta distribution model are used to calculate the direct trustworthiness value of nodes,while the historical trustworthiness between nodes and the activity of nodes in the network are taken into account in the calculation of indirect trustworthiness value.This method can recognize the malicious nodes more definitely.(2)In the aggregation of indirect and direct trustworthiness values of nodes,predecessors usually assigned two trustworthiness values directly and aggregated them to get comprehensive trustworthiness values of nodes.However,there are different opinions about how to calculate the weights,some of which can not satisfy the subjective tendency of the nodes to the direct trusted value of the tested nodes.Therefore,we synthetically considers the problems that should be paid attention to in the process of calculating the trustworthiness of nodes.We innovatively uses the fuzzy logic method to aggregate the direct and indirect trustworthiness of nodes.And we design a reasonable fuzzy logic model according to the requirements.The results of the experiments show that this method can reasonably adjust the weights of two trusted values according to individual needs,and get the comprehensive trusted values of nodes.(3)With the help of the node trustworthiness evaluation model designed by us,the MAODV(Multicast Ad hoc On-Demand Distance Vector Routing)protocol rules are improved.We specify how to establish and maintain multicast tree after encountering malicious nodes in multicast network.We also describe that how to determine the trusted value of multicast tree path.Finally,we modified the code of MAODV protocol and substituted it into NS-2 forsimulation.The results show that the modified protocol can identify malicious nodes more accurately and improve the transmission rate of data packets.