Wireless Coverage Area Computation and Optimization

Abstract

A wireless network's design must include the optimization of the area of coverage of its wireless transmitters - mobile and base stations in cellular networks, wireless access points in WLANs, or nodes on a transmit schedule in a wireless ad-hoc network. Typically, the coverage optimization for the common channels is solved by spatial multiplexing, i.e. keeping the access networks far apart. However, with increasing densities of wireless network deployments (including the Internet-of-Things) and paucity of spectrum, and new developments like whitespace devices and self-organizing, cognitive networks, there is a need to manage interference and optimize coverage by efficient algorithms that correctly set the transmit powers to ensure that transmissions only use the power necessary. In this work we study methods for computing and optimizing interference-limited coverage maps of a set of transmitters. We progress successively through increasingly realistic network scenarios. We begin with a disk model with a fixed set of transmitters and present an optimal algorithm for computing the coverage map. We then enhance the model to include updates to the network, in the form of addition or deletion of one transmitter. In this dynamic setting, we present an optimal algorithm to maintain updates to the coverage map. We then move to a more realistic interference model - the SINR model. For the SINR model we first show geometric bases for coverage maps. We then present a method to approximate the measure of the coverage area. Finally, we present an algorithm that uses this measure to optimize the coverage area with minimum total transmit power.