WLAN Channel Measurement in Two Classrooms for LOS and NLOS Coverage

Coverage optimization is a key problem for wireless local area networks (WLANs) deployed for indoor access. Appropriate WLAN deployment should be planned based on the accurate channel fading characteristics. In this paper, we conduct a measurement campaign in two typical university classrooms on the large-scale channel fading of an access point (AP) at 2.4 and 5.8 GHz for both line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios. Based on the experimental data, we analyze the underlying propagation mechanisms in path loss, shadowing effect, and multipath effect in this classroom scenario. We establish the dual-band channel fading model including all these factors. The measurement data and fading model provide in-depth insights into the signal propagation mechanisms and provide guidance for the energy-efficient WLAN deployment for campus coverage.

I. Introduction

Driven by the fast dissemination of mobile Internet, wireless local area networks (WLANs) have been widely installed at hot-spot locations, from airports and campuses to residential buildings, to support convenient and high-rate Internet access. The 2.4 and 5.8 GHz bands are two main license-free spectrum bands for WLANs globally. In recent years, WLANs have been widely set up on university campuses for students and teachers to surf the Internet, search for academic articles, exchange Emails and instant messages, etc. Since the seamless coverage on a university campus requires a large number of access points (APs) that consume huge power, optimized deployment of APs can effectively reduce the number of APs needed and in turn the energy consumption.