초록 ▼

In order to locate the position of a mobile station of a mobile radio system, the distance of the mobile station from a base transceiver station is determined, or the distances of the mobile station from at least two base transceiver stations are determined and the position is found by triangulation

In order to locate the position of a mobile station of a mobile radio system, the distance of the mobile station from a base transceiver station is determined, or the distances of the mobile station from at least two base transceiver stations are determined and the position is found by triangulation. In a GSM-type system, there is a predetermined known response delay between a particular signal received by the mobile station from the base transceiver station and a particular response transmitted from the mobile station to the base transceiver station; the distances can therefore be determined from the response delay and a measured period between transmission of the particular signal and reception of the particular response. In a GSM-type system, the mobile station transmits messages indicating the signal strengths of the base transceiver stations it is receiving, and on that basis the system allocates one of the base transceiver stations to the mobile station; in order to measure the distance between the mobile station and at least one other base transceiver station, the messages are modified in order to force a handover from one base transceiver station to another. In a CDMA-type system, the "soft hand-off" feature can be used to determine the distance to two or more BTSs at the same time.

대표청구항 ▼

[ We claim:] [1.] A position locating method for a mobile radio system having, facilities for performing an automated handover process between base stations in dependence upon indications of operating conditions unrelated to position locating, the position locating method comprising the steps of:mea

[ We claim:] [1.] A position locating method for a mobile radio system having, facilities for performing an automated handover process between base stations in dependence upon indications of operating conditions unrelated to position locating, the position locating method comprising the steps of:measuring a first property of a first communications link between a first base transceiver station of the mobile radio system and a mobile transceiver station of that system;calculating a distance between the first base station and the mobile station using the first measured property;modifying the indications of operating conditions to be inconsistent with actual operating conditions, so as to induce occurrence of a handover which would not otherwise occur and thereby cause the mobile transceiver to communicate with at least a second base transceiver station of the mobile radio system;measuring a second property of a second communications link between the second base transceiver station and the mobile transceiver station;calculating a distance between the second base station and the mobile station using the second measured property;performing the property measuring steps generally immediately before, at the time of, or immediately after the induced handover; andcalculating a position of the mobile station using the first and second calculated distances and known positions of the first and second base stations.