The University of British Columbia

To explore the energy saving advantage offered by the use of directional antennas, we consider the case of source initiated multicast traffic in static ad hoc wireless networks that use switched antennas and have limited energy resources. We present a constraint formulation for the joint optimization problem MEM-AO (minimum-energy multicast and antenna orientation) in terms of MTLP (mixed integer linear programming). The optimal solution can be obtained using an MILP solver in a timely manner for moderately sized networks with switched antennas. In addition to the theoretical effort, we also provide two heuristic algorithms and a general post-process operation TR (tree reconstruction) for handling larger networks. The experimental results show that our TR operation significantly improves the performance of both heuristic algorithms