On the Effectiveness of Switched Beam Antennas in Indoor Environments

Switched beam antennas are an attractive extension to indoor wireless LANs due to their increased signal gain in a chosen direction; the gain can be exploited for improving wireless link quality, node localization and increasing spatial reuse. However, indoor environments are susceptible to multipath reflections that may reduce the degree of directionality of the antennas. To this end, in this paper, we address the following questions that have not been explored well in the open literature: how directional in reality is a beam with a switched beam antenna in a reflection-rich environment, and what are the implications of the observed directionality on spatial reuse and node localization? And how does the directionality get affected with the characteristics of a beam such as main and side lobe width, and front to side lobe ratio? We present results of measurements in a real office setting with a switched beam antenna built out of an 8-element phase array.