Design of Indoor WLANs: Combination of a ray-tracing tool with the BPSO method.

This article presents an approach that combines a ray-tracing tool with the binary version of the particle swarm optimization (BPSO) method to the design of infrastructure-mode indoor wireless local area networks (WLANs). This approach uses the power levels of a set of candidate access point (AP) locations obtained with the ray-tracing tool at a mesh of potential receiver locations or test points to allow the BPSO optimizer to carry out the design of the WLAN. For this purpose, several restrictions are imposed through a fitness function that drives the search toward the selection of a reduced number of AP locations and their channel assignments while keeping low transmission power levels. During the design, different coverage priority areas can be defined, and the signal-to-interference ratio (SIR) levels are kept as high as possible to comply with the quality-of-service (QoS) requirements imposed. The performance of this approach in a real scenario at the authors´ premises is reported, showing its usefulness.