Equilibria for Broadcast Range Assignment Games in Ad-Hoc Networks

Ad-hoc networks are an emerging networking technology, in which the nodes form a network with no fixed infrastructure: each node forwards messages to the others by using the wireless links induced by their power levels. Hence, a major challenge in operation of ad-hoc networks is the efficient use of energy. Generally, energy-efficient protocols heavily rely on cooperation: only recently the behavior of networks formed by selfish nodes playing competitive network games has started to be analized, and mechanisms that stimulate nodes to cooperate have been proposed. In this paper, we analyze from a game-theoretic point of view the problem of performing a broadcast operation from a given station $s$. In particular, we first introduce a general game-theoretic framework and then show both theoretical and experimental results on how the existence of (good) Nash equilibria is determined by factors such as the transmission power that each station must use or the payment policy that stations can use to enforce their reciprocal cooperation. The experimental evaluation of our protocols has been performed by using both randomly generated instances and instances produced by means of a recent mobility model that takes into account the existence of obstacles