Architecture of a 802.11b Access Point with Single-Packet Radiolocation

This is the third in a series of articles describing an 802.11b (wi-fi) radiolocator. This device determines the direction of arrival of individual data packets, at a speed equal to the rate of wireless traffic. Radiolocation is based on rapid sampling of signal strengths from an array of stationary antennas, during the reception of a single wireless packet. This article addresses the issue of integrating the radiolocation and communication functions, which have incompatible requirements in their front-end RF sections and different real-time characteristics. We define an architecture in which these functions are integrated, describe the implementation in a working prototype device, and report the results of functionality tests. This work is intended to make radiolocation part of standard wireless infrastructure, with multiple benefits: it will improve diagnostics and security management of networks, and allow for adaptive directional response, which in turn leads to better signal quality and more rational usage of the wi-fi radio band.