Location systems and cellular communication networks

• US 20040192344A1
• Filed: 02/26/2003
• Published: 09/30/2004
• Est. Priority Date: 03/01/2002
• Status: Active Grant

• Current Assignee: Lenovo Innovations Ltd Hong Kong (Lenovo Group Ltd.)
• Original Assignee: NEC Corporation
• Inventors: Ormson, Richard
• Granted Patent: US 7,089,019 B2
• Time in Patent Office: Days
• 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;

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 unit therefrom, wherein each of the first transmitting and receiving units includes means to derive its location from a further set of received signals.

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.

5. A transmitting and receiving unit for use in a location system in a mobile communication network, comprising:

means for receiving known signals;

means for determining timing of receipt of the known signals;

means for transmitting the timing data to the mobile communication network;

means to receive signals from other sources;

means to determine location data from the signals from the other sources; and

means to transmit the location data to the mobile communication network.

6. The transmitting and receiving unit according to claim 5, wherein the other sources comprise satellites transmitting position determining data, and the means to determine location data operates on data received from the satellites.

7. The transmitting and receiving unit according to claim 5, wherein the means to determine location data, repeatedly determines the location data.

8. The transmitting and receiving unit according to claim 6, wherein the means to determine location data, repeatedly determines the location data.

9. The transmitting and receiving unit according to claims 6, wherein the means to transmit the location data to the mobile communication network only transmits the location data when the location data is within a predetermined limit of accuracy.

10. The transmitting and receiving unit according to claim 7, wherein the repeatedly determined location data is averaged over a predetermined number of samples.

11. The transmitting and receiving unit according to claim 8, wherein the repeatedly determined location data is averaged over a predetermined number of samples.

12. The transmitting and receiving unit according to claims 7, wherein the unit transmits a signal to the mobile communication network if the accuracy of its location data falls outside a predetermined unit.

13. The transmitting and receiving unit according to claims 5, wherein the mobile communication network comprises a cellular communication network.