08-05-2012, 05:13 PM
Game-Theoretic Investigation of Coaction Incentive Schemes in Mobile Ad Hoc Networks
ABSTRACT
In mobile ad hoc networks (MANETs), tasks are conducted based on the cooperation of nodes in the networks. Selfish nodes may refuse to be cooperative, since the nodes are usually constrained by limited computation resources. To overcome the node non-cooperation problem, we use, a) A reputation system, which evaluates node behaviours by reputation values and which uses a reputation threshold to distinguish trustworthy nodes and untrustworthy nodes, and, b) A price-based system which uses virtual cash to control the transactions of a packet forwarding service. In this paper, we use game theory to investigate the effectiveness of the node cooperation incentives provided by these two systems which were scarcely researched, and by a system with no cooperation incentive strategy. We find that the strategies of using a threshold to determine the trustworthiness of a node in the reputation system and of rewarding cooperative nodes in the price based system may be manipulated by clever or wealthy but selfish nodes. Illumined by the investigation results, we propose and study an integrated system with superiority in terms of the effectiveness of cooperation incentives and selfish node detection.