On Orientations of Directional Antennas in Wireless Sensor Network

The paper presents a model for the total Shannon capacity of a network as a function of antenna orientations. The resulting function is neither concave nor convex and is multi-extrema with multiple local optima. An optimum solution for the orientations of the directional antennas leads to the global maximization of the total channel capacity. This global optimization problem cannot be solved by classical nonlinear programming technique. The objective function is shown to be Lipschitzian and is optimized by a Lipschitz optimization algorithm. The algorithm is a realization of the generic branch and bound methodology. Simulation results are reported and discussed.