Locating Wireless Devices - Methods for locating devices in areas where GPS is unavailable
GPS has been warmly accepted in consumer devices in recent years. It works well when a good view of the sky is available. However, the signal levels from the satellites are already very low when they reach the surface of the Earth, and when subject to the extra attenuation of buildings and urban canyons, these signals can quickly become unusable. It is such cases which provide the impetus for our study.
The framework of our study is straightforward. Firstly, we look at applications where wireless devices may need to establish their location. Initially we focus on two key applications of interest to Ofcom. Secondly, we evaluate candidate location technologies which may help where today’s GPS does not work. This includes future developments of GNSS1 as well as a large number of non-GNSS location technologies. Thirdly, we match location technology capabilities with application requirements. Finally we lay out our conclusions.
In this study, our interest does not extend to locating or tracking people nor do we seek an alternative or back-up system to GPS. Our interest lies in locating wireless devices, specifically in cases where GPS cannot help. We have a UK focus, but a global outlook.