MOBILE DEVICE LOCATION SYSTEM FOR WIRELESS E911 SERVICES

摘要

Disclosed are systems and methods for locating a mobile telecommunication device within a building or underground facility. The system operates by receiving over a telecommunication network an emergency transmission from a mobile telecommunication device located within the facility. The system then determines propagation time delay of the received emergency transmission and identifies two or more RF nodes located within the facility in the proximity of the mobile device based on the determined propagation time delay. The system then sends a request to the identified RF nodes to perform signal strength measurements on the mobile telecommunication device. The system then compares the signal strength measurements of the RF nodes to estimate the approximate location coordinates of the mobile telecommunication device relative to the RF nodes within the facility.