Method and apparatus for supervising the performance of a quick paging channel in a dual event slotted paging system

• US 6,687,285 B1
• Filed: 03/19/1999
• Issued: 02/03/2004
• Est. Priority Date: 03/19/1999
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Jou, Yu-Cheun
• Primary Examiner(s): Bayard, Emmanuel
• Application Number:
  US09/272,802
• Time in Patent Office: 1,782 Days
• Field of Search: 375/130, 375/133, 375/141, 375/136, 375/137, 375/220, 370/278, 370/335, 370/431, 370/328, 370/441, 370/479, 370/331, 370/332, 455/442, 455/502, 455/676, 455/436, 455/440
• US Class Current: 375/133
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0219 where the power saving management affects multiple terminals
• CPC Class Codes: H04W 68/00 User notification, e.g. alerting and paging, for incoming communication, change of service or the like
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A mobile station operating in the slotted mode, while monitoring the Quick Paging Channel, monitors the Paging Channel in its assigned slot at least once every N minutes, regardless of what the Quick Paging Channel indicates for that slot. The mobile station shall keep a counter for the number of false alarms that have occurred and another counter for the number misses that have occurred. The count of accumulated false alarms (QPCH_FA) and the count of accumulated misses (QPCH_MISS) are stored by the mobile station and will be sent to the base station when so requested. These two counters can be reset at powering-up or by the base station via messaging, or both. When the number of accumulated misses in a given time interval T₁ exceeds a certain threshold N_m1, the mobile station may send a message to inform the base station of this. When the number of accumulated misses in a given time interval T₂ exceeds a threshold N_m2, the mobile station shall monitor the Paging Channel in its assigned slots regardless of what the Quick Paging Channel indicates. T₂ and N_m2 could be the same as or different from T₁ and N_m1, respectively. The mobile station returns to follow the Quick Paging Channel indication as to whether to monitor the Paging Channel or not when the number of accumulated misses in a given time interval T₃ drops below a certain threshold N_m3, or when N_h1 hits occur in a row, or both.

Claims

1. In a communication system wherein a receiver station receives information from a transmitting station, a method for monitoring a performance of a first channel indicative of the presence or absence of a forthcoming message at a receiver station, comprising the steps of:

receiving a signal on said first channel;

attempting to receive said forthcoming message;

determining from said steps of receiving a signal on said first channel and said step of attempting to receive said forthcoming message an indication of the performance of said first channel; and

maintaining a performance status of the first channel.

2. The method of claim 1 further wherein said an indication of the performance of said first channel comprises an assignment of an event as either a hit, a miss, or a false alarm.

3. The method of claim 1 wherein said an indication of the performance of said first channel comprises an assignment of an event as either a hit, a miss, a false alarm, or an erasure.

4. The method of claim 1 wherein said step of receiving a signal on a first channel comprises receiving a quick paging channel message.

5. The method of claim 1 wherein said step of receiving a signal on a first channel comprises the steps of:

demodulating a received signal in accordance with a first spreading code to provide a demodulated signal;

comparing an energy of said demodulated signal against at least one energy threshold; and

determining from said comparison the presence or absence of said forthcoming message.

6. The method of claim 5 wherein said step of attempting to receive said forthcoming message, comprises the steps of:

demodulating said received signal in accordance with a second spreading code to provide said forthcoming message; and

determining from data in said forthcoming message said indication of the performance of said first channel.

7. The method of claim 6 wherein said step of determining from data in said forthcoming message said indication of the performance of said first channel comprises searching for the inclusion of a mobile station identifier.

8. The method of claim 6 wherein said step of determining from data in said forthcoming message said indication of the performance of said first channel comprises performing a numerical algorithm on an identifier for the receiver station and a numerical algorithm on an identifier found in said forthcoming message and determining whether the result of the two numerical algorithms equate.

9. The method of claim 1 further comprising the steps of:

tracking a time interval between consecutive receptions of each of said forthcoming messages;

comparing said time interval against a threshold value; and

receiving said forthcoming message irrespective of the indication on said first channel when said time interval exceeds said threshold value.

10. The method of claim 2 further comprising the step of storing a record of a number of hits, misses, and false alarms that are recorded in a predetermined time interval.

11. The method of claim 5 further comprising the step of storing a record of a number of hits, misses, and false alarms that are recorded in a predetermined time interval.

12. The method of claim 11 further comprising the step of adjusting said energy threshold in accordance with said number of misses and false alarms.

13. The method of claim 12 further comprising the step of said receiver station transmitting a message indicative of the number of misses to said transmitting station.

14. The method of claim 13 further comprising the steps of:

receiving at said transmitting station said number of misses; and

adjusting the transmission energy of said first channel in accordance with said number of misses.

15. The method of claim 13 further comprising the steps of:

receiving at said transmitting station said number of misses; and

adjusting coding rate of said first channel in accordance with said number of misses.

16. The method of claim 2 further comprising the step of directly monitoring said forthcoming message when a number of said misses exceeds a predetermined threshold value.

17. The method of claim 1 further comprising the steps of:

transmitting a plurality of known symbols on said first channel wherein at least one of said known symbols represents the presence of a forthcoming message and wherein at least one of said known symbols represents the absence of a forthcoming message;

receiving said known symbols; and

adjusting an energy threshold value determinative of the detection of the presence or absence of said forthcoming message in accordance with the received energies of said known symbols.

18. The method of claim 6 wherein said step of determining from data in said forthcoming message said indication of the performance of said first channel comprises searching for an indication of a change in system configuration in said forthcoming message.

19. The method of claim 6 wherein said step of determining from data in said forthcoming message said indication of the performance of said first channel comprises identifying a sequence number indication within a paging message directed to said receiver station.

20. The method of claim 1 further comprising the steps of:

receiving a second signal with a known relationship between the second signal and the signal on said first channel;

measuring the received energy of said second signal; and

receiving said forthcoming message without regard to the signal on said first channel when the energy of said second signal is below a predetermined threshold.

21. A wireless communication system comprising:

a base station for transmitting Quick Page Messages on a Quick Paging Channel and Full Page Messages on a Paging Channel; and

a mobile station for monitoring the Quick Paging Channel to determine the presence or absence of a Full Page Message on the Paging Channel and maintaining a performance status of the quick Paging Channel.

22. A mobile station comprising:

a receiver for receiving an indication message on a first channel indicative of the presence or absence of a forthcoming message on a second channel, and for receiving the forthcoming message on the second channel; and

a control processor configured to evaluate the indication message received on the first channel and maintain a performance status of the first channel.

23. The mobile station as in claim 22, further comprising:

means for measuring energy of the received indication message;

means for comparing the energy of the received indication message to a threshold; and

declaring an erasure if the energy of the received indication message is below the threshold.

24. The mobile station as in claim 22, further comprising:

means for periodically monitoring an assigned slot of the second channel regardless of the indication message on the first channel.

25. The mobile station as in claim 24, wherein means for periodically monitoring an assigned slot of the second channel, comprises monitoring the assigned slot of the second channel over a time window.

26. The mobile station as in claim 25, wherein the time window is a moving window.

27. The mobile station as in claim 26, wherein the moving window starts on occurrence of receiving the indication message on the first channel and receiving the corresponding message on the second channel.

28. The mobile station as in claim 22, further comprising:

first counter responsive to occurrence of a miss; and

second counter responsive to occurrence of a hit; and

means for determining a status of the first channel based on the first and second counters.

29. The mobile station as in claim 28, further comprising:

means for comparing a count of the first counter to a threshold; and

means for monitoring each assigned slot of the second channel when the count of the first counter exceeds the threshold.

30. A base station comprising:

a control processor generating Quick Paging Messages and Full Page Messages;

a transmitter for transmitting the Quick Paging Messages on a Quick Paging Channel and the Full Page Messages on a Paging Channel, said transmitter for transmitting a request for a Quick Paging Channel status update; and

a receiver for receiving a Quick Paging Channel status message in response to the request for the Quick Paging Channel status update.

31. The base station as in claim 30, wherein the Quick Paging Channel is transmitted at a fixed transmission energy in relation to a pilot channel.

32. In a communication system, an apparatus for monitoring a performance of a first channel indicative of the presence or absence of a forthcoming message at a receiver station, comprising the steps of:

means for receiving a signal on said first channel;

means for attempting to receive said forthcoming message;

means for determining from said steps of receiving a signal on said first channel and said step of attempting to receive said forthcoming message an indication of the performance of said first channel; and

means for maintaining a performance status of the first channel.