An Effective Strategy for Greedy Behavior in Wireless Ad hoc Networks.

While the problem of greedy behavior at the MAC layer has been widely explored in the context of wireless local area networks, its study for multi-hop wireless networks still almost an unexplored and unexplained problem. Indeed, in a wireless local area network, an access point mostly forwards packets sent by wireless nodes over the wired link. In this case, a greedy node can easily get more bandwidth share and starve all other associated contending nodes by intelligently manipulating the MAC layer parameters. However, in wireless ad hoc environment, all packets are transmitted in a multi-hop fashion over wireless links. Therefore, if a greedy node behaves similarly as in WLAN case, trying to starve its neighbors, then its next hop forwarding node will also be prevented to forward its own traffic, which leads to an end-to-end throughput collapse. In this paper, we show that in order to have a more beneficial greedy behavior in wireless ad hoc networks, a node must adopt a different approach than in WLAN to achieve a better performance of its own flows. We then present a strategy to launch such greedy attack in a proactive routing based wireless ad hoc network. Through the extensive simulations, the obtained results show that by applying the proposed algorithm, a greedy node can gain more bandwidth than its neighbors and keep the end-to-end throughput of its own flows highly reasonable.