Coalition formation games for energy-efficient wireless network cocast

Wireless network cocast (WNC) is a cooperative communication protocol that overcomes the issues of imperfect frequency and timing synchronization while achieving spatial diversity to substantially reduce transmit power over direct transmission (DTX). Due to additional processing power in receiving and retransmitting each other information, however, not all nodes and WNC networks result in energy efficiency. To ensure energy efficient WNC networks, a TDMA-based merge process based on coalition formation games is proposed to orderly form cooperative groups. A node is merged into a cooperative group if the merge leads to power saving without causing additional power burden to individual nodes. Simulation shows that WNC networks require much less power to provide comparable quality of service of DTX networks. In addition, WNC networks achieve even power distribution, which improves the network lifetime.