Achieving Improved Network Subscriber Geo-Location

Future disaster and emergency management requirements are currently under discussion in the US and Europe that will require mobile phone network operators to locate their subscribers to a high level of accuracy within a short time period. Current deployed mobile phone geolocation systems are required to locate the caller to within 125 m. Future systems will require an order of magnitude better accuracy. This paper proposes a method to achieve improved location accuracy with the addition of carrier phase analysis and accurate time of flight techniques to current systems. The resulting combination of technologies has been analysed using a simplified model to benchmark and compare the subscriber location estimate against existing solutions. The system described in this paper shows the potential to meet the emerging disaster and emergency management requirements in complex radio frequency environments.