Indoor location estimation using multiple wireless technologies

Future mobile devices will increasingly have multiple sources of location information associated with them, such as GPS, cellular cell-sector ID, Bluetooth or 802.11 wireless LAN. In fact, cellular phones with GPS receivers and 802.11 wireless LAN are already becoming available. However, not all location technologies will operate everywhere (e.g. GPS typically will not work indoors whereas 802.11 coverage may be available) and they typically have different accuracies and range. This paper presents an experimental study of the feasibility of using multiple wireless technologies simultaneously for location estimation. We have collected signal strength information from both IEEE 802.11 and Bluetooth wireless network technologies, developed and applied algorithms for determining location using data for each wireless technology, and then used a simple algorithm for fusing the location estimates from both technologies to try to enhance the accuracy of the location estimates.