Collaborative watchdogs: A fast and efficient approach to deal with selfish nodes in MANETs

Mobile ad-hoc networks (MANETs) rely on network cooperation schemes to work properly. Nevertheless, if nodes have a selfish behaviour and are unwilling to cooperate, the overall network performance could be seriously affected. The use of watchdogs is a well-known mechanism to detect selfish nodes. In this paper we propose a collaborative watchdog approach, which is based on the fast diffusion of selfish nodes awareness. Then, we introduce an analytical model to evaluate the time of detection and the overhead (number of messages) of our collaborative watchdog approach. The results show that a collaborative watchdog is a very efficient approach since the detection time of selfish nodes is reduced, and the overall overhead is very low.