Timed-based ephemeris identity in assistance data and assistance data request messages

• US 20080228398A1
• Filed: 10/26/2007
• Published: 09/18/2008
• Est. Priority Date: 11/03/2006
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Technologies Oy (Nokia Corporation)
• Inventors: Halivaara, Ismo, Syrjarinne, Jyri
• Granted Patent: US 9,465,114 B2
• Time in Patent Office: Days
• US Class Current: 701/213
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/258 relating to the satellite constellation, e.g. almanac, ephemeris data, lists of satellites in view

Abstract

A module (software or ASIC) for use in a serving mobile Location Centre (SMLC) or a mobile station having a GPS receiver (or an A-GPS receiver) for determining an ITOW for a CNAV-1 signal. Also provided is a module for a mobile with GPS (or A-GPS receiver) so that the mobile can use the ITOW (either the ITOW provided with the CNAV-2, or that calculated for the CNAV-1) to uniquely identify ephemeris information in a request for assistance message. Also provided is a module for a SMLC by which the SMLC can use the IOD fields in the assistance data messages in a way that uniquely identifies the associated ephemeris information.

Claims

1. A method for use by a mobile station in obtaining navigation assistance from a navigation assistance server of a wireless network or for use by the navigation assistance server, comprising:

providing a time indication value for a navigation signal as an identifier of ephemeris information included in the navigation signal; and

using the identifier as a basis for determining whether the ephemeris information is more or less current compared to other ephemeris information.

2. A method as in claim 1, wherein the navigation signal does not include a time indication value, and wherein the providing of a time indication value includes deriving the value for the time indication based on a value for the time of receipt of the navigation signal and a value for the time of the beginning of the week.

3. A method as in claim 1, wherein the received navigation signal includes the time indication value, and wherein the providing of a time indication value includes obtaining the time indication value from the received navigation signal.

4. A method as in claim 1, wherein the method is for use by the mobile station, and the method further comprises providing a navigation assistance request message including the time of week value as an indication of the ephemeris information obtained from the navigation signal.

5. A method as in claim 1, wherein the method is for use by the navigation assistance server, and the method further comprises determining whether to provide current ephemeris information in response to a navigation assistance request from the mobile station, based on comparing the time indication value and a time indication value included in the navigation assistance request.

6. A method as in claim 1, wherein the navigation signal is an L2C or L5 signal of the well-known GPS or is a corresponding signal of another kind of global navigation satellite system.

7. A method as in claim 1, wherein the navigation signal is an L1C signal of the well-known GPS or is a corresponding signal of another kind of global navigation satellite system.

8. A method as in claim 1, wherein the time indication value is a time of week broadcast value and is provided as an 8-bit information element.

9. A method as in claim 1, wherein the time indication value is a time of week broadcast value, and when the time of week broadcast value is included in a navigation assistance request, the time of week broadcast value is provided as the eight least significant bits of an issue of data information element ordinarily included in the navigation assistance message.

10. A method as in claim 1, wherein the navigation assistance message is a global navigation satellite system message or a differential global navigation satellite system message.

22. A computer program product for use by a mobile station in obtaining navigation assistance from a navigation assistance server of a cellular network or for use by the navigation assistance server, comprising a computer readable storage structure embodying computer program code thereon for execution by a computer processor, wherein said computer program code comprises instructions for performing a method according to claim 1.

23. An application specific integrated circuit for use by a mobile station in obtaining navigation assistance from a navigation assistance server of a cellular network or for use by the navigation assistance server, configured for operation according to claim 1.

11. An apparatus for use by a mobile station in obtaining navigation assistance from a navigation assistance server of a cellular network or for use by the navigation assistance server, comprising:

an identifier creation module, for providing a time indication value for a navigation signal as an identifier of ephemeris information included in the navigation signal; and

a navigation assistance module, for using the identifier as a basis for determining whether the ephemeris information is more or less current compared to other ephemeris information.

12. An apparatus as in claim 11, wherein the navigation signal does not include a time indication value, and wherein the identifier creation module is configured to derive the value for the time indication based on a value for the time of receipt of the navigation signal and a value for the time of the beginning of the week.

13. An apparatus as in claim 11, wherein the received navigation signal includes the time indication value, and wherein the identifier creation module is configured to obtain the time indication value from the received navigation signal.

14. An apparatus as in claim 11, wherein the apparatus is for use by the mobile station, and the navigation assistance module is configured to provide a navigation assistance request message including the time indication value as an indication of the ephemeris information obtained from the navigation signal.

15. An apparatus as in claim 11, wherein the apparatus is for use by the navigation assistance server, and the navigation assistance module is configured to provide current ephemeris information in response to a navigation assistance request from the mobile station, based on comparing the time indication value and a time indication value included in the navigation assistance request.

16. An apparatus as in claim 11, wherein the navigation signal is an L2C or L5 signal of the well-known GPS or is a corresponding signal of another kind of global navigation satellite system.

17. An apparatus as in claim 11, wherein the navigation signal is an L1C signal of the well-known GPS or is a corresponding signal of another kind of global navigation satellite system.

18. An apparatus as in claim 11, wherein the time indication is a time of week broadcast value, and the time of week broadcast value is provided as an 8-bit information element.

19. An apparatus as in claim 11, wherein the time indication value is a time of week broadcast value, and when the time of week broadcast value is included in a navigation assistance request, the time of week broadcast value is provided as the eight least significant bits of an issue of data information element ordinarily included in the navigation assistance message.

20. An apparatus as in claim 11, wherein the navigation assistance message is a global navigation satellite system message or a differential global navigation satellite system message.

21. A method for use by a mobile station in obtaining navigation assistance from a navigation assistance server of a cellular network or for use by the navigation assistance server, comprising:

providing a time indication value for a navigation signal as an identifier of ephemeris information included in the navigation signal; and

using the identifier as a basis for determining whether the ephemeris information is more or less current compared to other ephemeris information.