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

Jose Basterrechea,Rafael P Torres,Jesus R Lopez,Marta Domingo,Jose Moreno,Luis Valle

doi:10.1109/map.2015.2480078

Jose Basterrechea, Rafael P Torres + Show 4 more

Open Access

https://doi.org/10.1109/map.2015.2480078

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Abstract

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.

Highlights

Wireless Local Area Networks (WLAN) based on IEEE 802.11 access technology, known as WiFi, have been widely deployed in recent years mainly due to the unlicensed character of their frequency bands of operation and the low cost of the equipment
The approach presented in this work uses the signal levels produced by the set of candidate access point (AP) at any of the receiver locations or test points, which are uniformly distributed over regular meshes covering the areas of interest, and that are computed with the help of the ray tracing method, to feed the BPSO optimizer and start the search for a feasible infrastructure mode wireless local area networks (WLAN) configuration that satisfies the coverage and signal to interference ratio (SIR) requirements at the test points
An approach for the optimization of infrastructure mode indoor WLAN from the downlink point of view has been presented in this paper

Summary

INTRODUCTION

Wireless Local Area Networks (WLAN) based on IEEE 802.11 access technology, known as WiFi, have been widely deployed in recent years mainly due to the unlicensed character of their frequency bands of operation and the low cost of the equipment. In the WLAN case, the APs have transmitter powers which are usually fixed or limited to a reduced discrete set of values, use nearly omnidirectional antennas and have a short number of non-overlapped channels available These features make the APs location choice and their channel assignment critical from the indoor WLAN design point of view due to the complex indoor environments. The ray tracing technique is used to obtain the signal levels produced by a set of candidate APs locations in a uniform mesh of testing points defined over the area where the indoor WLAN is intended to be deployed These data are used to feed the BPSO optimizer in the search for a feasible WLAN configuration. The receivers are considered to be connected to 2.15 dBi lossless matched antennas, located at the test points and at a height of 1.5 meters

THE BINARY PARTICLE SWARM OPTIMIZER

DESCRIPTION OF THE APPROACH

THE FITNESS FUNCTION

SIRmax

Findings

CONCLUSIONS