Determining neighbour lists

• US 20040166876A1
• Filed: 12/12/2003
• Published: 08/26/2004
• Est. Priority Date: 12/31/2002
• Status: Active Grant

• Current Assignee: Ciena Corporation
• Original Assignee: Nokia Corporation
• Inventors: Moilanen, Jani
• Granted Patent: US 7,231,217 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 36/00835 Determination of neighbour cell lists
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A method and system for compiling neighbour lists in a mobile communication network is described. A test signal is transmitted from one base station (BTS) to a set of location measurement units (LMU), one LMU preferably being associated with the transmitting BTS. The received signal is time stamped at each LMU and the transmission times calculated from the time stamps. The transmission times are compared and the list is compiled from those LMUs with close or the same transmission times.

Claims

1. A method of compiling a list of usable neighbour location measurement units in a mobile communications network comprising a plurality of transmitters with a plurality of location measurement units, the method comprising:

(a) receiving a signal from one of said transmitters at each of a set of said location measurement units and time stamping the signal with the arrival time at each location measurement unit;

(b) determining from the arrival time at each location measurement unit and its distance from the transmitting transmitter the transmission time;

(c) comparing the transmission times determined for each of the location measurement units and placing on the list only those location measurement units whose transmission times fall in a predetermined range of one another.

2. A method according to claim 1, wherein steps (a) to (c) are carried out for each transmitter.

3. A method according to claim 2, when carried out for a predetermined sequence of transmitters at predetermined time intervals.

4. A method according to claim 2, when carried out using a computer program executed on a processor.

5. A method according to claim 2, when carried out at a serving location measurement centre in the network.

6. A method according to claim 1, wherein said time stamping is carried out using a global clock.

7. A method according to claim 1, which comprises the step of identifying one of said set of location measurement units as a target location measurement unit associated with said transmitter;

comparing the transmission times for the remaining ones of the set of location measurement units with the transmission time for the target location measurement unit; and

only placing the target location measurement unit on the list if its transmission time falls in said predetermined range.

8. A method according to claim 1, wherein each transmitter is associated with a base station.

9. A method according to claim 1, comprising the step of checking coordinates of a transmitter using the transmission times.

10. A method according to claim 7, wherein said target location measurement is identified as the location measurement unit physically located at said transmitter.

11. A serving measurement location centre in a mobile communications network having a plurality of transmitters with a plurality of location measurement units, the centre comprising:

a processor arranged to receive from each of a set of the location measurement units receiving a signal from one of the transmitters a transmission time calculated at the respective measurement units;

a store holding a list of useful location measurement units;

said processor being programmed to compare the transmission times determined at each of the location measurement units and to place on the list only the location measurement units whose determined transmission times fall in a predetermined range of one another.

12. A serving measurement location centre according to claim 11, wherein the processor is arranged to receive a signal from each of the transmitters.

13. A serving measurement location centre according to claim 12, wherein the processor is arranged to receive a signal from a predetermined sequence of transmitters at predetermined time intervals.

14. A serving measurement location centre according to claim 11, wherein the processor is programmed to identify one of said set of location measurement units as a target location measurement unit associated with said transmitter, to compare the transmission times for the remaining ones of the set of location measurement units with the transmission time for the target location measurement unit, and only placing the target location measurement unit on the list if its transmission time falls in said predetermined range.

15. A serving measurement location centre according to claim 11, wherein said transmitters are located at base stations.

16. A serving measurement location centre according to claim 14, wherein said target location measurement unit is physically located at said transmitter.

17. A serving measurement location centre according to claim 11, comprising a data store holding data defining the distances of each of the location measurement units from said transmitter.

18. A serving measurement location centre according to claim 17, which comprises means for calculating said transmission times based on said distance data.

19. A computer program product comprising program code means which when executed on a processor cause the processor to receive from each of a set of location measurement units associated with the base stations a transmission time calculated at the respective location measurement unit, and to further cause the processor to compare the transmission times determined at each of the location measurement units and to place on a list of usable neighbour location measurement units only those whose transmission times fall in a predetermined range of one another.