GPS assistance messages in cellular communications networks and methods therefor

• US 20020168985A1
• Filed: 02/16/2001
• Published: 11/14/2002
• Est. Priority Date: 02/16/2001
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility, Inc. (Lenovo Group Ltd.)
• Inventors: King, Thomas M., Geier, George J., Zhao, Yilin
• Granted Patent: US 7,747,257 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/07 providing data for correcting measured positioning data, e.g. DGPS [differential GPS] or ionosphere corrections
• CPC Class Codes: G01S 19/071 DGPS corrections
• CPC Class Codes: G01S 19/08 providing integrity information, e.g. health of satellites or quality of ephemeris data
• CPC Class Codes: G01S 19/258 relating to the satellite constellation, e.g. almanac, ephemeris data, lists of satellites in view
• CPC Class Codes: H04B 7/18554 using the position provided by an existing geolocalisation system
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

GPS assistance message and data issue identifiers for transmission to GPS enabled mobile stations in cellular communications networks and methods therefor. The GPS data issue identifiers indicate whether GPS data, for example corresponding ephemeris and almanac data, stored at the mobile station requires updating. In the exemplary 3^rd generation (W-CDMA/UMTS) architecture, the GPS assistance message is a System Information Block (SIB), and the GPS ephemeris data identifier and corresponding satellite identifier is encoded in a value tag included in a Master Information Block (MIB).

Claims

1. A method for updating a GPS ephemeris data issue identifier transmitted to a GPS enabled mobile station in a cellular communications network, comprising:

receiving GPS ephemeris data at a reference node in communication with a cellular communications network;

generating an assistance message including GPS ephemeris data and other parameters;

generating a GPS ephemeris data issue identifier;

receiving updated GPS ephemeris data and other updated parameters;

updating the GPS ephemeris data issue identifier only when the GPS ephemeris data has been updated.

2. The method of claim 1, not updating the GPS ephemeris data issue identifier when parameters other than the GPS ephemeris data change.

3. The method of claim 1, transmitting a GPS ephemeris data issue identifier over the cellular communications network, receiving the GPS ephemeris data issue identifier at a mobile station, comparing the received GPS ephemeris data issue identifier with a corresponding GPS ephemeris data issue identifier stored at the mobile station, reading a corresponding ephemeris assistance message at the mobile station only if the received GPS ephemeris data issue identifier is different than the stored GPS ephemeris data issue identifier.

4. The method of claim 1,

receiving GPS ephemeris data from a plurality of satellites at a reference node in communication with a cellular communications network;

generating a plurality of assistance messages including GPS ephemeris data from the plurality of satellites and other parameters;

generating a GPS ephemeris data issue identifier for each of the plurality of assistance messages;

updating the plurality of GPS ephemeris data issue identifiers only when the GPS ephemeris data of the corresponding assistance message has been updated.

5. The method of claim 4, encoding each of the GPS ephemeris data issue identifiers and a corresponding satellite identifier in a corresponding sequence of binary digits, transmitting the sequence of binary digits over the network.

6. A method for updating a GPS almanac data issue identifier transmitted to a GPS enabled mobile station in a cellular communications network, comprising:

receiving GPS almanac data at a reference node in communication with a cellular communications network;

generating an assistance message including GPS almanac data and other parameters;

generating a GPS almanac data issue identifier;

receiving updated GPS almanac data and other updated parameters;

updating the GPS almanac data issue identifier only when the GPS almanac data has been updated.

7. The method of claim 6, not updating the GPS almanac data issue identifier when parameters other than the GPS almanac data change.

8. The method of claim 6, transmitting a GPS almanac data issue identifier over the cellular communications network, receiving the GPS almanac data issue identifier at a mobile station, comparing the received GPS almanac data issue identifier with a GPS almanac data issue identifier stored at the mobile station, reading an almanac assistance message at the mobile station only if the received GPS almanac data issue identifier is different than the stored GPS almanac data issue identifier.

9. The method of claim 6, GPS almanac data issue identifier is for a cell, updating the GPS almanac data issue identifier by incrementing a 2-bit data field when the almanac data in the reference node is updated.

10. The method of claim 6, GPS almanac data issue identifier for a Public Mobile Land Network (PLMN) value tag, updating the value tag by incrementing an 8-bit data field when the almanac data is in the reference node is updated.

11. A master information block (MIB) for indicating to a GPS enabled mobile station in a cellular communications network changes in a corresponding system information block (SIB) having ephemeris data and correction clock data and other parameters, comprising:

an ephemeris value tag,

the ephemeris value tag dependent only on changes in GPS ephemeris data in the corresponding SIB,

the ephemeris value tag independent of the correction clock data and any other parameters of the corresponding SIB.

12. The MIB of claim 11, the ephemeris value tag having at least an 8-bit data field, 4 data bits identifying a corresponding satellite and 4 data bits identifying a GPS ephemeris data issue.

14. The system information block of claim 15, the almanac value tag is for a Public Mobile Land Network (PLMN), the almanac value tag having at least an 8-bit data field.

15. The system information block of claim 14, 4 data bits identifying a corresponding satellite and 4 data bits identifying a GPS almanac data issue.

17. The GPS ephemeris data issue identifier of claim 16, the first field is at least 5 bits, the second field is at least 3 bits.

18. The GPS ephemeris data issue identifier of claim 16 is a broadcast message.

13. A master information block (MIB) for indicating to a GPS enabled mobile station in a cellular communications network changes in a corresponding system information block (SIB) having almanac data and other parameters, comprising:

an almanac value tag,

the almanac value tag dependent only on changes in GPS almanac data in the corresponding SIB,

the almanac value tag independent of any other parameters of the corresponding SIB.

16. A GPS ephemeris data issue identifier for transmission to a GPS enabled mobile station in a cellular communications network, comprising:

a first field with satellite identifier data; and

a second field with an ephemeris sequence number.

20. A master information block (MIB) for transmission to a GPS enabled mobile station in a cellular communications network, comprising:

a value tag having a sequence of binary bits,

at least one combination of the binary bit indicates real-time GPS satellite integrity data.

21. A method for updating GPS ephemeris data in a cellular communications network mobile station, comprising:

obtaining ephemeris data by reading an ephemeris assistance message at the mobile handset;

evaluating validity of the ephemeris data in the mobile station by determining an age of the ephemeris data;

updating the ephemeris data by reading a new ephemeris assistance message when the stored ephemeris data reaches certain age.

22. The method of claim 21, determining the age of the ephemeris data by:

t−

t_oe, where “

t”

is the current time and “

t_oe”

is the Time of Ephemeris.

24. The method of claim 22, determining the age of the almanac data by:

t−

t_oa, where “

t”

is the current time and “

t_oa”

is the Time of Almanac.

23. A method for updating GPS almanac data in a cellular communications network mobile station, comprising:

obtaining almanac data by reading an almanac assistance message at the mobile handset;

evaluating validity of the almanac data in the mobile station by determining an age of the almanac data;

updating the almanac data by reading a new almanac assistance message when the stored almanac data reaches certain age.