Optimally Placing Base Stations in a Microcellular Urban Environment

With the increasing demand for cheaper and better wireless services from the customers, and the move towards smaller cell sizes, it is becoming very important to optimally design the cell geometries, and deploy the minimum number of base stations to provide maximum possible coverage. The gradual decrease in cell sizes with the objective of providing services to more number of users has lead to the design of microcells. These microcells have the base station antennas located well within the local environments and usually below the local building rooftops. In this paper we consider how to optimally determine the locations for the placement of base stations for a wireless system in an urban setting, given the data for building heights and their locations. The optimality of the base stations is with respect to the total coverage area using the minimum number of base stations. Coverage is being defined as the percentage of area from where it is possible to establish a communication link with at least one of the base stations. In an urban setting, where we expect a relatively high density of tall buildings, line of sight (LOS) links may not be always possible. Wherever LOS link is not possible, a non-LOS link might be considered, taking into account the attenuation of the radio waves through the building walls (and the roof, as the case may be).