Method for locating mobile stations in a digital telephone network

• US 5,564,079 A
• Filed: 05/31/1994
• Issued: 10/08/1996
• Est. Priority Date: 06/21/1993
• Status: Expired due to Term

• Current Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Original Assignee: Telia AB (Government of Norway)
• Inventors: Olsson, Bo
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): ARTHUR JEANGLAUDE, GERTRUDE
• Application Number:
  US08/251,366
• Time in Patent Office: 861 Days
• Field of Search: 455/54.1, 455/67.1, 455/54.2, 455/56.1, 455/33.1, 342/357, 342/457, 364/449, 364/460, 364/461, 395/22
• US Class Current: 455/456.3
• CPC Class Codes: G01S 5/02525 Gathering the radio frequency fingerprints
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

The invention relates to a method for locating mobile stations in a digital telecommunication network, especially the GSM network. According to the invention, reference measurements are carried out on relevant traffic routes with the aid of a measuring mobile in order to provide position information related to measured signals. With the aid of these reference data and the position information, an adaptive neural network is trained, which network, with the aid of corresponding measurement data which are transmitted from the mobile station to a respective base station, carries out the localization of the mobile station. Use of the adaptive neural network provides a more accurate position determination than earlier systems which were only based on the TA (timing advance) value.

Claims

1. Method for locating a mobile station in a digital telecommunication network, comprising the step of:

measuring no-location reference data indicative of signal strength and timing advance signals from plural base stations, wherein the measuring is performed at a reference mobile station on relevant traffic routes at known positions of the mobile station,

training an adaptive neural network using the measured non-location reference data as inputs and the known positions of the reference mobile station as desired outputs,

measuring at a subscriber mobile station non-location data indicative of signal strength and timing advance signals from said plural base stations, wherein the measured non-location data are transmitted from the subscriber mobile station to at least one of said plural base stations, and

determining a location of the subscriber mobile station using the trained adaptive neural network, wherein the trained neural network is coupled to the plural base stations and determines the location of the subscriber mobile station using the measured non-location data from the subscriber mobile station.

2. Method according to claim 1, wherein the step of measuring non-location reference data comprises:

using the reference mobile station equipped with GPS receiver to measure the non-location reference data.

3. Method according to claim 1 or 2, wherein the step of training the adaptive neural network comprises:

training the adaptive neural network by inputting the measured non-location reference data,

calculating a position from the measured non-location reference data,

comparing the calculated position with a respective one of the known positions of the reference mobile station, and

adjusting the adoptive neural network based on the comparison.