GSM Network-Based Timing Advance Positioning

• US 20080227469A1
• Filed: 03/10/2008
• Published: 09/18/2008
• Est. Priority Date: 03/13/2007
• Status: Abandoned Application

• Current Assignee: Kestrel Signal Processing, Inc.
• Original Assignee: Kestrel Signal Processing, Inc.
• Inventors: Burgess, David, Samra, Harvind, Baliga, Roshan
• Application Number:
  US12/045,690
• Publication Number:
  US 20080227469A1
• Time in Patent Office: Days
• US Class Current: 455/456.2
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Embodiments for locating mobile stations in a GSM cellular network are disclosed.

Claims

1. A system for determining the locations of mobile stations within a GSM cellular network, comprising:

(a) at least one mobile station (MS), capable of reporting the timing advance (TA), as detailed in the 3GPP Technical Specification 5.10; and

(b) at least one base transceiver station (BTS), capable of recording the reported TA from each registered MS; and

(c) a central or distributed software element that records reported TAs from each MS; and

includes a database of BTS locations; and

performs calculations to locate each MS.

2. The system of claim 1, comprising at least two BTSs, wherein each BTS is capable of forcing a handover to a neighboring BTS to determine the reported TAs from one MS to multiple BTSs.

3. The system of claim 1, wherein:

(a) said software element includes a database of handset IMEIs and associated delay bias; and

(b) said software element removes the delay bias from reported TAs prior to performing location calculations.

4. The system of claim 1, wherein said software element is capable of keeping a history of successive TA measurements to further refine the calculated MS position.

5. The system of claim 2, wherein said software element is capable of directing a BTS to perform a specific handoff to a second BTS to further refine TA measurements and calculated MS position.

6. The system of claim 2, wherein the BTS uses radio channel estimates from a software-defined radio to produce TA estimates with sub-symbol accuracies.