Sleep mode for wireless communication device during out of service operation

• US 20070207841A1
• Filed: 03/06/2006
• Published: 09/06/2007
• Est. Priority Date: 08/08/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Amerga, Messay, Mittal, Vineet, Umatt, Bhupesh
• Granted Patent: US 8,527,014 B2
• Time in Patent Office: Days
• US Class Current: 455/574
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: H04W 52/287 when the channel is in stand-by
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The disclosure is directed to techniques for performing service signal searches with reduced power consumption when a wireless communication device is operating out of service. The techniques include placing the wireless communication device in a “deep sleep” mode when the wireless communication device is not in service. When operating in the deep sleep mode, the wireless communication device reduces power consumption by not looking for paging signals or searching for service signals. The wireless communication device then may periodically enter a wake-up period during which power consumption is increased to perform signal searches in one or more frequency bands. The wireless communication device returns to the deep sleep mode when the signal searches are unsuccessful.

Claims

1. A method comprising:

placing a wireless communication device in a deep sleep mode to reduce power consumption in the wireless communication device when operating out of service;

periodically increasing power in the wireless communication device to initiate one or more wake-up periods;

performing a service signal search in one or more frequency bands supported by the wireless communication device during the wake-up periods; and

returning the wireless communication device to the deep sleep mode when the service signal search is unsuccessful.

2. The method of claim 1, further comprising receiving one or more service requests during the wake-up periods that identify the one or more frequency bands in which to perform the service signal search.

3. The method of claim 1, wherein the supported frequency bands are divided into at least two band groups, the method further comprising receiving service requests during the wake-up periods that identify one of the band groups in which to perform the service signal search.

4. The method of claim 3, wherein receiving service requests comprises:

receiving one or more initial service requests for one of the band groups; and

receiving subsequent service requests for another one of the band groups when the service signal search based on the initial service requests is unsuccessful,

wherein the initial service requests are received during a first wake-up period and the subsequent service requests are receiving during a second wake-up period.

5. The method of claim 3, wherein receiving the initial service requests comprises receiving a plurality of initial service requests for a high priority one of the band groups that includes channels on which the wireless communication device previously received service.

6. The method of claim 1, wherein performing the service signal search comprises performing an acquisition database scan on the one or more supported frequency bands, and wherein performing the acquisition database scan comprises searching for a service signal on channels of the supported frequency bands included in an acquisition database.

7. The method of claim 6, wherein the acquisition database includes preloaded channels and dynamically learned channels, and wherein the dynamically learned channels comprise channels on which the wireless communication device previously received service.

8. The method of claim 6, wherein performing the service signal search comprises performing a full frequency scan on the supported frequency bands when the acquisition database scan is unsuccessful.

9. The method of claim 8, wherein performing the full frequency scan comprises searching for a service signal on each channel of the supported frequency bands.

10. The method of claim 8, wherein performing the full frequency scan comprises:

performing a coarse frequency scan on the supported frequency bands;

performing a fine frequency scan on the supported frequency bands; and

performing a code space search on each channel of the supported frequency bands.

11. The method of claim 8, wherein performing the full frequency scan comprises performing the full frequency scan on the supported frequency bands when a full frequency timer expires.

12. The method of claim 1, wherein periodically increasing power in the wireless communication device comprises increasing power in the wireless communication device to initiate the wake-up periods after operating the wireless communication device in the deep sleep mode for a predefined period of time.

13. The method of claim 1, further comprising performing both an acquisition database scan and a full frequency scan on the supported frequency bands for a predetermined number of service requests during the wake-up period.

14. The method of claim 13, further comprising starting a full frequency timer after the predetermined number of service requests, and performing only an acquisition database scan on the supported frequency bands for service requests during the wake-up periods until the full frequency timer expires.

15. The method of claim 13, further comprising starting a no service timer after the predetermined number of service requests when no public land mobile networks are found during the service signal search, and automatically generating a no service indication until the no service timer expires.

16. The method of claim 1, further comprising generating a no service indication when the service signal search is unsuccessful, and generating a service indication when the service signal search is successful.

17. The method of claim 1, further comprising removing the wireless communication device from the deep sleep mode when the service signal search is successful.

18. The method of claim 1, wherein the wireless communication device supports communication according to a code division multiple access (CDMA) standard or a wideband CDMA (W-CDMA) standard.

19. A computer-readable medium comprising instructions that cause a processor to:

place a wireless communication device in a deep sleep mode to reduce power consumption in the wireless communication device when operating out of service;

periodically increase power in the wireless communication device to initiate one or more wake-up periods;

perform a service signal search in one or more frequency bands supported by the wireless communication device during the wake-up periods; and

return the wireless communication device to the deep sleep mode when the service signal search is unsuccessful.

20. The computer-readable medium of claim 19, further comprising instructions that cause the processor to receive service requests during the wake-up periods that identify the one or more frequency bands in which to perform the service signal search.

21. The computer-readable medium of claim 19, wherein the supported frequency bands are divided into at least two band groups, further comprising instructions that cause the processor to:

receive initial service requests for one of the band groups during a first wake-up period; and

receive subsequent service requests for another one of the band groups during a second wake-up period when the service signal search based on the initial service requests is unsuccessful.

22. The computer-readable medium of claim 19, wherein the instructions that cause the processor to perform the service signal search cause the processor to perform an acquisition database scan on the one or more supported frequency bands.

23. The computer-readable medium of claim 22, wherein the instructions that cause the processor to perform the service signal search cause the processor to perform a full frequency scan on the supported frequency bands when the acquisition database scan is unsuccessful.

24. The computer-readable medium of claim 19, further comprising instructions that cause the processor to perform both an acquisition database scan and a full frequency scan on the supported frequency bands for a predetermined number of service requests during the wake-up periods.

25. The computer-readable medium of claim 24, further comprising instructions that cause the processor to start a full frequency timer after the predetermined number of service requests, and perform only an acquisition database scan on the supported frequency bands for service requests during the wake-up periods until the full frequency timer expires.

26. The computer-readable medium of claim 24, further comprising instructions that cause the processor to start a no service timer after the predetermined number of service request when no public land mobile networks are found during the service signal search, and automatically return a no service signal until the no service timer expires.

27. The computer-readable medium of claim 19, further comprising instructions that cause the processor to remove the wireless communication device from the deep sleep mode when the service signal search is successful.

28. The computer-readable medium of claim 19, further comprising instructions that cause the processor to:

generate a no service indication when the service signal search is unsuccessful; and

generate a service indication when the service signal search is successful.

29. The computer-readable medium of claim 19, wherein the wireless communication device supports communication according to a code division multiple access (CDMA) standard or a wideband CDMA (W-CDMA) standard.

30. A wireless communication device comprising a controller that:

places a wireless communication device in a deep sleep mode to reduce power consumption in the wireless communication device when operating out of service;

periodically increases power in the wireless communication device to initiate one or more wake-up periods;

performs a service signal search in one or more frequency bands supported by the wireless communication device during the wake-up periods; and

returns the wireless communication device to the deep sleep mode when the service signal search is unsuccessful.

31. The device of claim 30, further comprising a system determination module, coupled to the controller, that generates service requests within the wireless communication device during the wake-up periods, wherein the service requests identify the frequency bands in which to perform the service signal search.

32. The device of claim 30, further comprising a system determination module, coupled to the controller, that divides the supported frequency bands into at least two band groups, wherein the system determination module generates:

initial service requests for one of the band groups during a first wake-up period; and

subsequent service requests for another one of the band groups during a second wake-up period when the service signal search based on the initial service requests is unsuccessful,

wherein the initial and subsequent service requests identify the frequency bands in which to perform the service signal search.

33. The device of claim 30, wherein the initial service requests comprise service requests for a high priority one of the band groups that includes channels on which the wireless communication device previously received service, and the controller receives a plurality of consecutive service requests from the system determination module for the high priority one of the band groups.

34. The device of claim 30, further comprising a search module, wherein the controller directs the search module to perform an acquisition database scan to search for a service signal on channels of the supported frequency bands included in an acquisition database within the device.

35. The device of claim 34, wherein the acquisition database includes preloaded channels and dynamically learned channels, wherein the dynamically learned channels comprise channels on which the wireless communication device previously received service.

36. The device of claim 34, wherein the controller directs the search module to perform a full frequency scan on the supported frequency bands when the acquisition database scan is unsuccessful.

37. The device of claim 36, further comprising a full frequency timer coupled to the controller, wherein the controller directs the search module to perform the full frequency scan on the supported frequency bands when the full frequency timer expires.

38. The device of claim 30, further comprising a power supply coupled to the controller that provides increased power to the controller to initiate the wake-up periods after the controller operates the wireless communication device in the deep sleep mode for a predefined period of time.

39. The device of claim 30, further comprising a no service timer coupled to the controller, wherein the controller starts the no service timer when no public land mobile networks are found during the service signal search, and wherein the controller automatically provides a no service indication to a system determination module within the wireless communication device until the no service timer expires.

40. The device of claim 30, wherein the controller provides a no service indication to a system determination module within the wireless communication device when the service signal search is unsuccessful, and the controller provides a service indication to the system determination device when the service signal search is successful.

41. The device of claim 30, wherein the controller removes the wireless communication device from the deep sleep mode when the service signal search is successful.

42. The device of claim 30, wherein the wireless communication device supports communication according to a code division multiple access (CDMA) standard or a wideband CDMA (W-CDMA) standard.