Locating mobile terminals

• US 20050255854A1
• Filed: 12/01/2004
• Published: 11/17/2005
• Est. Priority Date: 05/12/2004
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Sillasto, Eero, Spirito, Maurizio
• Granted Patent: US 7,680,501 B2
• Time in Patent Office: Days
• US Class Current: 455/456.100
• CPC Class Codes: G01S 5/0263 by combining or switching between positions derived from two or more separate positioning systems
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A method of providing a location estimate for a mobile station in a wireless communications network. The method of providing the location estimate includes implementing, in parallel, a plurality of different location estimate generation methods, each location generation method generating a location estimate. The method of providing the location estimate also includes selecting one of the location estimates based on predetermined criteria.

Claims

1. A method of providing a particular location estimate for a mobile station in a wireless communications network, the method comprising:

implementing in parallel a plurality of different location estimate generation methods, each method generating a location estimate; and

selecting a one of the location estimates based on predetermined criteria.

2. The method according to claim 1, wherein the mobile station has a radio link with a set of sites, the method further comprising:

determining respective distances between each site in the set of sites and the location estimates, wherein the predetermined criteria use the distances.

3. The method according to claim 2, wherein each location estimate generation method comprises:

generating a distance estimate, the distance estimate comprising an estimate of a distance of a mobile station from each site, wherein the predetermined criteria use these distance estimates in combination with said distances to minimize an error function.

4. The method according to claim 2, further comprising:

using location data of said sites in a first one of said plurality of different location estimate generation methods.

5. The method according to claim 4,

wherein said first location estimate generation method generates its location estimate as a weighted mass center of said sites.

6. The method according to claim 1, wherein a second one of said plurality of different location calculation methods comprises:

using first measurement data relating to at least one radio link between a mobile station and a first site in a location calculation method with radio network data of the first site to provide a first preliminary location estimate;

using second measurement data relating to at least one radio link between the mobile station and a second site in the location calculation method with radio network data of the second site to provide a second preliminary location estimate; and

generating the particular location estimate as a weighted mass center of the first and second preliminary location estimates.

7. The method according to claim 6, further comprising:

supporting a plurality of cells with the first site; and

relating the first measurement data to radio links of at least two of said plurality of cells,

wherein providing the first preliminary location estimate comprises generating a single first distance estimate using the first measurement data of the at least two radio links, and wherein providing the second preliminary location estimate comprises generating a second distance estimate using the second measurement data.

8. The method according to claim 6, further comprising:

supporting at least first and second located cells with the first site, wherein the first measurement data relates to a first radio link from the first located cell;

receiving further measurement data which relates to a second radio link from the second located cell; and

using the further measurement data in the location calculation method with the radio network data to provide a further preliminary location estimate which is used with the first and second preliminary location estimates to generate the weighted mass center of the particular location estimate of the mobile station.

9. A network entity in a cellular communications network, the network entity configured to provide a particular location estimate for a mobile station in the network, the network entity comprising:

first implementing means for implementing in parallel a plurality of different location estimate generation methods, each method generating a location estimate; and

selecting means for selecting one of the location estimates based on predetermined criteria.

10. The network entity according to claim 9, further comprising:

second implementing means for implementing a location calculation method using measurement data relating to radio links between the mobile station and respective first and second sites and radio network data to provide respective first and second preliminary location estimates; and

first determining means for determining the particular location estimate as a weighted mass center of the first and second preliminary location estimates.

11. The network entity according to claim 10, further comprising:

a radio network controller operably connected to at least one of the first implementing means, the selecting means, the second implementing means, and the first determining means.

12. The network entity according to claim 10, further comprising:

second determining means for determining respective distances between each site and the location estimates, wherein the predetermined criteria use the respective distances.

13. The network entity according to claim 12, further comprising:

generating means for generating distance estimates, each distance estimate comprising an estimate of a distance of the mobile station from each site, wherein the predetermined criteria use the distance estimates in combination with said distances to minimize an error function.

14. A network entity in a cellular communications network, the network entity configured to provide a particular location estimate for a mobile station in the network, the network entity comprising:

a processor configured to implement in parallel a plurality of different location estimate generation methods, each method generating a location estimate; and

a controller configured to select one of the location estimates based on predetermined criteria.