METHOD OF DETERMINING CURRENT LOCATION OF MOBILE STATIONS

PCT No. PCT/DE95/00293 Sec. 371 Date Sep. 12, 1996 Sec. 102(e) Date Sep. 12, 1996 PCT Filed Mar. 6, 1995 PCT Pub. No. WO95/25410 PCT Pub. Date Sep. 21, 1995Process and apparatus for locating mobile stations in a cellular mobile radio network. The apparatus may include a plurality of radio cells in which each radio cell is supplied by at least one base station, a plurality of transmitters in which each of the plurality of transmitters establish a locally defined underlay broadcast cell, the plurality of transmitters being located within at least one of the plurality of radio cells, a signal receiving and evaluating device associated with a respective mobile station that receives signals from the plurality of radio cells and the plurality of transmitters, information comparing units associated with the respective mobile station that compare information about one of the plurality of underlay broadcast cells received from a corresponding base station of the mobile radio network and information about the locally defined underlay broadcast cell received from one of the plurality of transmitters, a position determination device, and a device that forwards information about the locally defined underlay broadcast cell from the one transmitter to the position determination device when the compared information agree. The process may include emitting an underlay broadcast cell from the base stations of the mobile radio network, receiving, at the mobile stations, information about the underlay broadcast cell emitted from a corresponding base station of the mobile radio network, receiving, at the mobile stations, information about the locally defined underlay broadcast cell emitted from the transmitter, comparing the information received at the mobile stations from the corresponding base station and the transmitter, and determining a position of the mobile stations with the information received from the transmitter if the compared information agree.