Methods and apparatus for sharing cell coverage information

• US 20050192031A1
• Filed: 02/25/2005
• Published: 09/01/2005
• Est. Priority Date: 02/27/2004
• Status: Active Grant

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Vare, Jani
• Granted Patent: US 7,369,861 B2
• Time in Patent Office: Days
• US Class Current: 455/456.6
• CPC Class Codes: G01S 5/0236 Assistance data, e.g. base station almanac
• CPC Class Codes: G01S 5/02523 Details of interaction of receiver with radio-map
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data
• CPC Class Codes: H04W 36/322 by location data
• CPC Class Codes: H04W 48/14 using user query or user detection
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

An apparatus and methods are provided for sharing cell coverage information among devices in a cell network. Cell coverage information includes bitmap models of signal strength to enable intelligent handover decisions. Mobile terminals are able to receive cell coverage information over a broadband unidirectional broadcast network, such as a digital video broadcast network. They are also able to receive cell coverage information from other mobile terminals via ad hoc wireless signalling. Mobile terminals are also able to store and upload raw signal measurements to a cell coverage information center.

Claims

1. A method for sharing cell coverage information the method comprising:

transmitting a request from a mobile terminal for cell coverage information, and wherein the request comprises one of a geographic location and a cell identifier; and

receiving a response to the request, wherein the response comprises cell coverage information for the one of a geographic location and a cell identifier.

2. The method of claim 1, further comprising:

determining a destination cell for a handover procedure using the received cell coverage information.

3. The method of claim 2, further comprising:

determining that cell coverage information is needed for the one of a geographic location, and a cell identifier in order to assist in making a handover decision.

4. The method of claim 3, further comprising:

determining a direction and speed of travel of the mobile terminal to assist in making a handover decision.

5. The method of claim 1, wherein the response comprises a bitmap model of signal strengths for a cell.

6. The method of claim 1, wherein the response is received from a mobile terminal.

7. The method of claim 1, wherein the request for cell coverage information comprises a longitude and a latitude.

8. The method of claim 1, wherein transmitting a request for cell coverage information comprises using an ad hoc signalling system to transmit the request to a second mobile terminal.

9. The method of claim 1, wherein the cell coverage information relates to cells in a digital unidirectional broadband broadcast system.

10. A mobile terminal comprising:

a memory, wherein cell coverage information is stored in the memory, and wherein the cell coverage information comprises a bitmap representation of the cell signal strength;

a positioning system, capable of determining a geographic location of the mobile terminal;

a receiver, capable of receiving cell coverage information; and

a processor, configured to perform the steps of receiving cell coverage information via the receiver, storing the cell coverage information in the memory, determining a travel vector based on changes in the geographic location of the mobile terminal over time, and determining a destination cell for a handover based on the cell coverage information.

11. The mobile terminal of claim 10, wherein the cell coverage information is received from one of a mobile terminal and a broadcast signal.

12. The mobile terminal of claim 10, wherein the cell coverage information stored in the memory comprises a bitmap model of signal strengths.

13. The mobile terminal of claim 10, wherein the cell coverage information relates to cells in a digital video broadcast system.

14. The mobile terminal of claim 10, further comprising:

a transmitter, and wherein the processor is further configured to transmit a request for cell coverage information via the transmitter.

15. The mobile terminal of claim 14, wherein the processor is further configured to record cell coverage information by storing in the memory a longitude, a latitude, and a signal strength of a cell signal at a moment in time.

16. The mobile terminal of claim 15, wherein the processor is further configured to transmit via the transmitter cell coverage information previously stored in the memory.

17. The mobile terminal of claim 14, wherein the transmitter comprises one of a cellular radio, a Bluetooth radio, a WiFi radio, a UWB radio, an infrared source, and an RFID transmitter.

18. The mobile terminal of claim 14, wherein the request for cell coverage information comprises one of a geographic location, a cell identifier, and a postal code.

19. The mobile terminal of claim 14, wherein the memory stores login information for a computer containing cell coverage information.

20. A mobile terminal comprising:

a memory, wherein at least a bitmap model of cell signal strengths is stored in the memory;

a global positioning system, capable of providing a longitude and a latitude of the mobile terminal;

a digital broadband unidirectional broadcast receiver, capable of receiving at least the bitmap model of cell signal strengths;

a transmitter, capable of transmitting at least the bitmap model of cell signal strengths;

a processor, configured to perform the steps of receiving cell coverage information via the receiver, storing at least the bitmap model of cell signal strengths in the memory, determining a travel vector based on changes in the longitude and latitude of the mobile terminal over time, and determining a destination cell for a handover based on the travel vector and at least the bitmap model of cell signal strengths.