Trust-based on-demand multipath routing in mobile ad hoc networks

A mobile ad hoc network (MANET) is a self-organised system comprised of mobile wireless nodes. All nodes act as both communicators and routers. Owing to multi-hop routing and absence of centralised administration in open environment, MANETs are vulnerable to attacks by malicious nodes. In order to decrease the hazards from malicious nodes, the authors incorporate the concept of trust to MANETs and build a simple trust model to evaluate neighbours' behaviours forwarding packets. Extended from the ad hoc on-demand distance vector (AODV) routing protocol and the ad hoc on-demand multipath distance vector (AOMDV) routing protocol, a trust-based reactive multipath routing protocol, ad hoc on-demand trusted-path distance vector (AOTDV), is proposed for MANETs. This protocol is able to discover multiple loop-free paths as candidates in one route discovery. These paths are evaluated by two aspects: hop counts and trust values. This two-dimensional evaluation provides a flexible and feasible approach to choose the shortest path from the candidates that meet the requirements of data packets for dependability or trust. Furthermore, the authors give a routing example in details to describe the procedures of route discovery and the differences among AODV, AOMDV and AOTDV. Several experiments have been conducted to compare these protocols and the results show that AOTDV improves packet delivery ratio and mitigates the impairment from black hole, grey hole and modification attacks.