We study multi-hop broadcast in wireless networks with one source node and multiple receiving nodes. The message flow from the source to the receivers can be modeled as a tree-graph, called broadcast-tree. The problem of finding the minimum-power broadcast-tree (MPBT) is NP-complete.Unlike most of the existing centralized approaches, we propose a decentralized algorithm, based on a non-cooperative cost-sharing game. In this game, every receiving node, as a player, chooses another node of the network as its respective transmitting node for receiving the message. Consequently, a cost is assigned to the receiving node based on the power imposed on its chosen transmitting node.In our model, the total required power at a transmitting node consists of (i) the transmit power and (ii) the circuitry power needed for communication hardware modules. We develop our algorithm using the marginal contribution (MC) cost-sharing scheme and show that it is the only scheme by which the optimum broadcast-tree is always a Nash equilibrium (NE) of the game. Simulation results demonstrate that our proposed algorithm outperforms conventional algorithms for the MPBT problem. Besides, we show that the circuitry power, which is usually ignored by existing algorithms, significantly impacts the energy-efficiency of the network.
Index TermsEnergy-efficiency; minimum-power multi-hop broadcast; potential game; optimization. is disseminated through the network with the help of some intermediate nodes which re-transmit the message. This problem is known as the minimum-power broadcast-tree (MPBT) problem since the connections between the source and the receiving nodes form a tree-graph rooted at the source, called the broadcast-tree [1]. MPBT construction has been studied by researchers extensively during the past two decades [1][2][3][4][5][6][7][8][9][10][11][12]. NP-completeness of the MPBT can be shown by reducing the Steiner tree problem to it [13]. This means that a polynomial-time algorithm to find the optimum broadcast-tree unlikely exists. Although many algorithms have been proposed for the MPBT problem, most of them are centralized heuristics [1-6]. Since multi-hop device-todevice communication is seen as a promising technique for improving the capacity of 5G cellular networks [14] and due to the variety of its applications, e.g., video streaming [15], vehicular communications [16], etc., it is vital to revisit the MPBT problem to find a decentralized yet efficient algorithm for it.Seeing the MPBT problem from a decentralized optimization point of view, every individual node has to play its own role in forming the broadcast-tree by establishing a communication link to another node. This can be suitably modeled by game theory, in which the players of the game, here the nodes, are typically modeled as selfish agents seeking to minimize (maximize) their own cost (revenue). In our work, the action of a node is to choose another node in the network as its respective transmitting node to receive the source's message from. As a consequence of i...