Method and apparatus for broadcasting position location data in a wireless communication system

• US 20020072378A1
• Filed: 07/10/2001
• Published: 06/13/2002
• Est. Priority Date: 07/14/2000
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gaal, Peter
• Granted Patent: US 6,895,249 B2
• Time in Patent Office: Days
• US Class Current: 455/456.5
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 5/0045 Transmission from base station to mobile station G01S5/009 takes precedence
• CPC Class Codes: G01S 5/0236 Assistance data, e.g. base station almanac
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Techniques to efficiently broadcast position location data (PLD) from a base station to a number of terminals. In one aspect, PLD messages are classified into groups, and each group is broadcast in a different manner. For example, a first group of messages for PLD related to the base station is broadcast in an unscheduled format, and a second group of messages for PLD related to GPS satellites is broadcast in a scheduled format. In another aspect, a schedule for the second group describes the specific PLD elements selected for broadcast, their broadcast order, and the specific time intervals of their broadcast. The schedule is valid for a particular scheduled time interval, and the scheduling table is broadcast multiple times during the scheduled time interval to allow the terminals to quickly retrieve the schedule and ascertain what PLD information is being broadcast and where to look for specific PLD elements.

Claims

1. In a wireless communication system, a method for broadcasting messages from a base station to a plurality of terminals, comprising:

a) composing a scheduling table of times at which one or more messages will be transmitted; and

b) transmitting the scheduling table at regularly scheduled times to enable the terminals to determine when the one or more messages are transmitted.

2. In a wireless communication system, a method for broadcasting position location data (PLD) from a base station to a plurality of terminals, comprising:

classifying a plurality of messages used to convey a plurality of types of PLD information into a plurality of groups based on one or more characteristics of the PLD information;

selecting a particular transmission scheme for each group of messages; and

broadcasting the messages in each group in accordance with the selected transmission scheme.

3. The method of claim 2, wherein the plurality of groups include first and second groups, and wherein the PLD information for the messages in the first group has longer longevity than the PLD information for the messages in the second group.

4. The method of claim 2, wherein the plurality of groups include a first group for PLD information related to the base station and a second group for PLD information related to satellites in a Global Positioning Satellite (GPS) system.

5. The method of claim 4, wherein the messages in the first group are broadcast using an unscheduled transmission scheme and the messages in the second group are broadcast using a scheduled transmission scheme.

6. The method of claim 4, further comprising:

encapsulating the PLD information for the messages in the second group into a composite message;

defining a schedule for broadcasting the composite message; and

broadcasting the composite message in accordance with the defined schedule.

7. The method of claim 4, wherein each of at least one message in the first group is encapsulated within a predefined overhead message.

8. In a wireless communication system, a method for broadcasting position location data (PLD) from a base station to a plurality of terminals, comprising:

selecting one or more PLD elements for broadcast to the plurality of terminals, wherein each PLD element corresponds to a unit of PLD information of a particular type and for a particular transmitter;

defining a schedule for broadcasting the one or more selected PLD elements;

forming a scheduling table representative of the defined schedule; and

broadcasting the scheduling table and the one or more selected PLD elements to the plurality of terminals.

9. The method of claim 8, wherein the schedule is indicative of the one or more PLD elements selected for broadcast and their broadcast order.

10. The method of claim 9, wherein the schedule is further indicative of specific time intervals over which the scheduling table and the one or more selected PLD elements are broadcast.

11. The method of claim 9, wherein the schedule is further indicative of one or more broadcast channels used to broadcast the scheduling table and the one or more selected PLD elements.

12. The method of claim 8, wherein the schedule is valid for a particular scheduled time interval.

13. The method of claim 12, wherein the scheduled time interval is greater than 500 seconds.

14. The method of claim 12, wherein the scheduling table is broadcast a plurality of times during the scheduled time interval.

15. The method of claim 12, wherein the scheduling table is broadcast a plurality of times at periodic time intervals during the scheduled time interval.

16. The method of claim 12, wherein the scheduling table and the one or more selected PLD elements are broadcast within a PLD cycle of a particular time duration, and wherein the PLD cycle is repeated a plurality of times during the scheduled time interval.

17. The method of claim 8, wherein the transmitter is a satellite in a Global Positioning Satellite (GPS) system.

18. The method of claim 17, wherein the one or more selected PLD elements comprise Almanac information for one or more GPS satellites.

19. The method of claim 17, wherein the one or more selected PLD elements comprise Almanac Correction information for one or more GPS satellites.

20. The method of claim 17, wherein the one or more selected PLD elements comprise Ephemeris information for one or more GPS satellites.

21. The method of claim 8, further comprising:

encapsulating the scheduling table and the one or more selected PLD elements into a composite message; and

broadcasting the composite message in accordance with the defined schedule.

22. The method of claim 8, further comprising:

partitioning the scheduling table and the one or more selected PLD elements into one or more PLD segments; and

broadcasting each PLD segment in a respective broadcast cycle of a particular time duration.

23. The method of claim 22, wherein each PLD segment includes the scheduling table.

24. The method of claim 22, wherein each PLD segment is broadcast over a particular time interval in the broadcast cycle.

25. The method of claim 24, wherein a starting time and a duration of the particular time interval are defined by the schedule.

26. The method of claim 8, wherein the wireless communication system is a CDMA system.

27. The method of claim 26, wherein the CDMA system implements cdma2000 standard.

28. The method of claim 26, wherein transmission time for one or more broadcast channels used to broadcast the scheduling table and the one or more selected PLD elements is partitioned into broadcast cycles and each broadcast cycle is further partitioned into a plurality of slots, wherein the scheduling table and the one or more selected PLD elements are partitioned into one or more PLD segments, and wherein each PLD segment is broadcast over one or more slots of one broadcast cycle.

29. The method of claim 28, wherein each PLD segment is broadcast starting at a particular slot index.

30. A base station in a wireless communication system, comprising:

a controller operative to

select one or more PLD elements for broadcast, wherein each PLD element corresponds to a unit of PLD information of a particular type and for a particular transmitter,

define a schedule for broadcasting the one or more selected PLD elements, and

forming a scheduling table representative of the defined schedule; and

a transmit data processor coupled to the controller and operative to process the scheduling table and the one or more selected PLD elements for broadcast to the plurality of terminals.

31. The base station of claim 30, wherein the schedule is indicative of the one or more selected PLD elements, their broadcast order, and specific time intervals for their broadcast, and wherein the schedule is valid for a particular scheduled time interval and the scheduling table is broadcast a plurality of times during the scheduled time interval.

32. The base station of claim 30, wherein the transmitter is a satellite in a Global Positioning Satellite (GPS) system, and wherein the one or more selected PLD elements comprise Almanac information, Almanac Correction information, Ephemeris information, or a combination thereof for one or more GPS satellites.