Location systems and cellular communication networks

• US 7,089,019 B2
• Filed: 02/26/2003
• Issued: 08/08/2006
• Est. Priority Date: 03/01/2002
• Status: Expired due to Fees

• Current Assignee: Lenovo Innovations Ltd Hong Kong (Lenovo Group Ltd.)
• Original Assignee: NEC Corporation
• Inventors: Ormson, Richard
• Primary Examiner(s): Eng, George
• Assistant Examiner(s): NGUYEN, KHAI MINH
• Application Number:
  US10/374,497
• Publication Number:
  US 20040192344A1
• Time in Patent Office: 1,259 Days
• Field of Search: 455/456.1, 455/456.2, 455/456.3, 455/456.4, 455/422.1, 455/456.5, 455/414.2, 340988-996, 342450-465, 342/357.1, 342/357.11, 342/357.06
• US Class Current: 455/456.1
• CPC Class Codes: G01S 5/0063 of measured values, i.e. measurement on base station and position calculation on mobile
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A location system for use in a mobile communication network includes base stations which transmit known signals at predetermined times for use in deriving location data; a first transmitting and receiving units; a unit for determining times of arrival of the known signals from each base station at each of the first transmitting and receiving units; a unit for determining times of arrival of the known signals from each base station at a second transmitting and receiving unit at an unknown location; a comparing unit for comparing timing differences between the known signals received at the first transmitting and receiving units and the second transmitting and receiving unit; and location determining unit for determining the location of the second unit. Each of the first transmitting and receiving units includes a unit for deriving its location from a further set of received signals such as GPS signals.

Claims

1. A location system for use in a mobile communication network comprising:

a plurality of base stations which transmit known signals at predetermined times for use in deriving location data;

a plurality of first transmitting and receiving units positioned at known locations, the first transmitting and receiving units not being base stations, and each of the first transmitting and receiving units having a means for deriving its location from a further set of received signals originating from sources external to the mobile communication network;

means for determining times of arrival of the known signals from each base station at each of the first transmitting and receiving units;

means for determining times of arrival of the known signals from each base station at a second transmitting and receiving unit at an unknown location;

means for comparing timing differences between the known signals received at the first transmitting and receiving units and the second transmitting and receiving unit; and

means for determining the location of the second transmitting and receiving unit therefrom.

2. The location system according to claim 1, wherein the further set of received signals comprise signals received from a satellite location system.

3. The location system according to claim 2, wherein the satellite location system is the Global Positioning System (GPS), and the means to derive a location from a further set of received signals comprises a GPS receiver.

4. The location system according to claim 1, wherein the mobile communication network comprises a cellular communication network.