A distributed joint scheduling and power control algorithm for multicasting in wireless ad hoc networks

This paper addresses the problem of power control in ad hoc networks supporting multicast traffic. First, we present a distributed algorithm which, given the set of multicast transmitters and their corresponding receivers, provides an optimal solution to the power control problem, if there is any. The transmit power levels obtained by solving the optimization problem minimize the network power expenditure while meeting the requirements of the SNR at the receivers. Whenever no optimal solution can be found for the given set multicast transmitters, we introduce a joint scheduling and power control algorithm, which eliminates the strong interferers thus allowing the other transmitters to solve the power control problem. The algorithm can be implemented in a distributed manner; however, it provides a sub-optimal solution since it is based on local information. Simulation results show that the obtained solution is close to the global optimum, when it exists. When there is no optimal solution, the proposed algorithm tries to maximize the number of successful multicast transmission.