Trust-Based Task Assignment With Multiobjective Optimization in Service-Oriented Ad Hoc Networks

We propose and analyze a trust management protocol in service-oriented mobile ad hoc networks (MANETs) populated with service providers and service requesters, and demonstrate the resiliency and convergence properties against bad-mouthing, ballot-stuffing, opportunistic service, and self-promotion attacks. To demonstrate the applicability, we consider a mission-driven service-oriented MANET that must handle dynamically arriving tasks to achieve multiple conflicting objectives. We devise a trust-based heuristic algorithm based on auctioning with local knowledge of node status to solve this node-to-task assignment problem with multiobjective optimization (MOO) requirements. Our trust-based heuristic algorithm has a polynomial runtime complexity, rather than an exponential runtime complexity as in existing work, thus allowing dynamic node-to-task assignment to be performed at runtime. It outperforms a nontrust-based counterpart using blacklisting techniques while performing close to the ideal solution quality with perfect knowledge of node status over a wide range of environmental conditions. We conduct extensive sensitivity analysis of the results with respect to key design parameters and alternative trust protocol designs. We also develop a table-lookup method to apply the best trust protocol parameter settings upon detection of dynamically changing environmental conditions to maximize MOO performance.