Modeling Signal Attenuation in IEEE 802.11 Wireless LANs-Vol. 1

Path loss models are used to approximate signal attenuation as a function of the distance between transmitters and receivers, being an important building block for both research and industry efforts. In this paper we present experimental data that validates the use of the log-distance model both inside and outside a standard office building. Our measurements were performed using off-the-shelf IEEE 802.11b hardware and with distances varying from 1 to 50 meters. The values found for the path loss exponent agree with previously published results (α = 4.02, 3.32). Moreover, linear regression produced models with acceptable standard deviations (< 8 dB) and suggest the occurrence of log-normal shadowing, as the deviations from the mean (in decibels) closely follow a Gaussian distribution.