Impact of selfish nodes on route discovery in mobile ad hoc networks

It is against our intuition that being selfish sometimes can be beneficial to both oneself and others. In a mobile ad hoc network (MANET), we show potential use of this concept by categorizing mobile hosts into normal nodes and selfish nodes. Normal nodes forward packets for other nodes while selfish nodes do not. The advantage of using selfish nodes is that the total rebroadcast traffic during flooding based route discovery can be reduced. The disadvantage, in theory, is that we may miss the optimal route and suffer from a low delivery rate. In this paper, we propose a probabilistic approach to set up a proper number of selfish nodes. Using a combination of gossiping and dominating set, we can reduce the route discovery cost by minimizing the number of rebroadcasts, while achieving higher delivery rate due to the reduction of rebroadcast traffic, thereby reducing the number of collisions. We compare our approach with AODV in terms of several metrics, including average number of rebroadcasts, average number of packet collisions, end-to-end delay, and throughput. Simulation results show that our approach outperforms the AODV protocol in most cases.