An Incentive-Based Forwarding Protocol for Mobile Ad Hoc Networks with Anonymous Packets

摘要

A mobile ad hoc network (MANET) station acts both as a source packet generator and transit packet forwarder. With selfish stations and the absence of administrative cooperation enforcement, the lack of forwarding incentives has long been recognized as a serious design problem in MANETs. Reputation systems discourage selfishness by having past cooperation increase the present source packet throughput. We describe a simple watchdog-controlled first-hand reputation system and point to a form of selfishness not addressed by existing research, arising from packet anonymity. If the watchdog at a station cannot tell a nearby station's source packets from transit packets, that station is tempted to admit more source packet traffic than a fair local admittance control (LAC) scheme permits. We analyze a related noncooperative LAC game and characterize three types of its Nash equilibria. Next we propose a simple packet forwarding protocol by the name Decline and Force (D&F) and using an approximate performance model show that, when properly configured, D&F leads to a fair and efficient game outcome.