Abstract: The location of a mobile station in a mobile cellular communication system is determined by taking measurements of known transmissions from the mobile station at a plurality of base stations. The serving base station sends a control message to the mobile station to induce the mobile station to transmit a known bit sequence. The known bit sequence transmitted by the mobile station is received at a plurality of base stations. The time of arrival of the known bit sequence at each base station is determined and used to calculate the location of the mobile station.