A decentralised communication architecture for detecting selfish behaviour in wireless mesh networks
Wireless Mesh Networks (WMNs) consist of dedicated nodes, called mesh routers, which relay the traffic generated by mesh clients over multi-hop paths. In a community WMN, all mesh routers may not be managed by an Internet Service Provider (ISP). Limited capacity of wireless channels and lack of a single trusted authority in such networks can motivate mesh routers to behave selfishly by dropping relay traffic to provide a higher throughput to their own users. Existing solutions for stimulating cooperation in multi-hop networks use promiscuous monitoring, or exchange probe packets to detect selfish nodes. These schemes do not operate well when applied to WMNs which have multi-radio and multi-channel environments. In this thesis, we propose distributed communication architecture for detecting selfish behaviour in WMNs. The architecture adopts a decentralized detection scheme by partitioning the network into manageable clusters. The network consists of agents that monitor the behaviour of mesh routers in their cluster by collecting periodic traffic reports and sending them to the sink agents. The sink agents maintain the reputation of the mesh routers based upon their current, as well as, past behaviours. We discuss mechanisms for updating the reputation and isolating selfish mesh routers to enforce cooperation among them. To make the detection scheme more accurate, the quality of wireless links was considered in our study. We present the experimental results that evaluate the performance of our scheme in terms of its effectiveness, accuracy, and communication overhead.