With the proliferation of wireless networks and the declining cost of wireless devices there is increasing interest in the development of location aware applications. These applications include robotics, context aware systems to collect or disseminate information, duress alarms in institutions such as hospitals and prisons and security of the wireless network.\ \ There are many technologies that may be used to sense the location of mobile devices or personnel, including those based on infrared, ultrasonic, radio frequency tags and magnetic sensing. Most of these technologies require the deployment of devices specifically placed to support the location system. This paper focuses on a location system based on the RSSI of packets on the IEEE 802.11b wireless network. This technique has the great advantage that it may be implemented using off the shelf hardware that is generally already deployed to support the data network.\ \ A simple wireless network was deployed in the School of Computing Building at the Newnham Campus of the University of Tasmania and used to test the location performance of a location system based on Bayesian filtering of detected signal strengths.