A system and method for determining a position of a wireless mobile device. The method comprising the steps of providing one base station in communication with the mobile device, providing a sensor spaced apart a known distance from the base station, and determining the range between the mobile device and the base station. The time of arrival of a signal transmitted from the mobile device is measured at the sensor and a set of coordinates is calculated for the mobile device relative to the sensor as a function of the known distance from the sensor to the base station, the range between the mobile device and the base station, an estimate of base station transmission timing relative to a time source, and the time of arrival. One of the set of coordinates may then be chosen to thereby determine a position of the mobile device relative to the sensor.