Multi-level duty cycling

• US 8,473,013 B2
• Filed: 05/09/2008
• Issued: 06/25/2013
• Est. Priority Date: 04/23/2008
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Julian, David Jonathan, Lee, Chong U., Jia, Zhanfeng
• Primary Examiner(s): Chang, Kent
• Assistant Examiner(s): AU, SCOTT D
• Application Number:
  US12/118,376
• Publication Number:
  US 20090270030A1
• Time in Patent Office: 1,873 Days
• Field of Search: 455572-574, 4553431-3435, 455/515, 455/450
• US Class Current: 455/572
• CPC Class Codes: H04B 1/1615 Switching on; Switching off, e.g. remotely battery saving circuits associated with selective call operation H04W52/00; details of power consumption reduction in a PLL, H03L7/0802, H03L7/14, H03L2207/08, H03L2207/18; muting amplifiers by gain control see H03G3/34
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 52/0274 by switching on or off the equipment or parts thereof
• CPC Class Codes: H04W 52/04 TPC
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A duty cycle scheme for wireless communication employs three or more duty cycle levels. In some aspects, a wireless device may continually scan for signals in an active state associated with a first duty cycle, periodically scan for signals during a periodic state associated with a second duty cycle, and periodically scan for signals during a standby state associated with a third duty cycle. Here, the second duty cycle may be lower than the first duty cycle and the third duty cycle may be lower than the second duty cycle. In some aspects the timing of different states may be correlated. In some aspects each wireless device in a system may independently control its duty cycle states.

Claims

1. A method of wireless communication, comprising:

scanning a channel according to a first duty cycle during a first operational state;

scanning the channel according to a second duty cycle during a second operational state, wherein the second duty cycle is lower than the first duty cycle; and

scanning the channel according to a third duty cycle during a third operational state, wherein the third duty cycle is lower than the second duty cycle; and

wherein the channel scanning according to the second duty cycle comprises periodically scanning at times based on a first time interval, the channel scanning according to the third duty cycle comprises periodically scanning at times based on a second time interval, and the second time interval is longer than the first time interval.

2. The method of claim 1, wherein the first operational state comprises an active state, the second operational state comprises a periodic state, and the third operational state comprises a standby state.

3. The method of claim 1, wherein the channel scanning according to the first duty cycle comprises continuously scanning the channel.

4. The method of claim 1, wherein:

the channel scanning according to the first duty cycle comprises periodically scanning at times based on a third time interval; and

the third time interval is shorter than the first time interval.

5. The method of claim 4, wherein the third time interval corresponds to a scanning rate that is high enough to capture a preamble of an asynchronous packet.

6. The method of claim 4, wherein a duration of any one of the first time interval, the second time interval, or the third time interval is based on at least one of:

a size of a packet preamble, clock drift, or a probability of not detecting a packet.

7. The method of claim 1, further comprising:

transitioning from the first operational state to the second operational state if a signal is not received during a first timeout period; and

transitioning from the second operational state to the third operational state if a signal is not received during a second timeout period.

8. The method of claim 7, wherein each signal comprises a packet, a data packet, a paging message, a discovery message, or a control message.

9. The method of claim 1, further comprising:

transitioning from the first operational state to the second operational state if a signal is not received during a first defined quantity of successive channel scans; and

transitioning from the second operational state to the third operational state if a signal is not received during a second defined quantity of successive channel scans.

10. The method of claim 9, wherein each signal comprises a packet, a data packet, a paging message, a discovery message, or a control message.

11. The method of claim 1, further comprising:

transitioning from the third operational state to the first operational state if a signal is received; and

transitioning from the second operational state to the first operational state if a signal is received.

12. The method of claim 11, wherein each signal comprises a packet, a data packet, a paging message, a discovery message, or a control message.

13. The method of claim 1, further comprising correlating periodic timing of the scanning during the third operational state with periodic timing of the scanning during the second operational state.

14. The method of claim 13, wherein the periodic timing of the scanning during the third operational state and the periodic timing of the scanning during the second operational state are based on a common timing offset.

15. The method of claim 1, further comprising transmitting a response signal if a signal is received during any of the channel scanning, wherein the response signal comprises an acknowledgement message or a response to a paging message.

16. The method of claim 1, further comprising:

receiving a paging message; and

transmitting a response to the paging message, wherein timing of the transmission of the response provides an indication of timing of the scanning during the second operational state, the third operational state, or the second and third operational states.

17. The method of claim 1, further comprising:

receiving a paging message; and

transmitting a response to the paging message, wherein the response includes an indication of timing of the scanning during the second operational state, the third operational state, or the second and third operational states.

18. The method of claim 1, further comprising:

receiving paging messages from a plurality of nodes within a defined period of time; and

transmitting a single response to the paging messages.

19. The method of claim 18, wherein the transmission of the single response comprises broadcasting the single response over a channel that is common to the plurality of nodes.

20. The method of claim 18, wherein a length of a preamble of the single response is based on relative scanning period times associated with the plurality of nodes.

21. The method of claim 1, wherein at least one of the first duty cycle, the second duty cycle, or the third duty cycle is based on a node type.

22. An apparatus for wireless communication, comprising:

a state controller configured to control transitions between a first operational state, a second operational state, and a third operational state; and

a receiver configured to;

scan a channel according to a first duty cycle during the first operational state;

scan the channel according to a second duty cycle during the second operational state, wherein the second duty cycle is lower than the first duty cycle; and

scan the channel according to a third duty cycle during the third operational state, wherein the third duty cycle is lower than the second duty cycle; and

wherein the channel scanning according to the second duty cycle comprises periodically scanning at times based on a first time interval, the channel scanning according to the third duty cycle comprises periodically scanning at times based on a second time interval, and the second time interval is longer than the first time interval.

23. The apparatus of claim 22, wherein the first operational state comprises an active state, the second operational state comprises a periodic state, and the third operational state comprises a standby state.

24. The apparatus of claim 22, wherein the channel scanning according to the first duty cycle comprises continuously scanning the channel.

25. The apparatus of claim 22, wherein:

the channel scanning according to the first duty cycle comprises periodically scanning at times based on a third time interval; and

the third time interval is shorter than the first time interval.

26. The apparatus of claim 25, wherein the third time interval corresponds to a scanning rate that is high enough to capture a preamble of an asynchronous packet.

27. The apparatus of claim 25, wherein a duration of any one of the first time interval, the second time interval, or the third time interval is based on at least one of:

a size of a packet preamble, clock drift, or a probability of not detecting a packet.

28. The apparatus of claim 22, wherein the state controller is further configured to:

transition from the first operational state to the second operational state if a signal is not received during a first timeout period; and

transition from the second operational state to the third operational state if a signal is not received during a second timeout period.

29. The apparatus of claim 28, wherein each signal comprises a packet, a data packet, a paging message, a discovery message, or a control message.

30. The apparatus of claim 22, wherein the state controller is further configured to:

transition from the first operational state to the second operational state if a signal is not received during a first defined quantity of successive channel scans; and

transition from the second operational state to the third operational state if a signal is not received during a second defined quantity of successive channel scans.

31. The apparatus of claim 30, wherein each signal comprises a packet, a data packet, a paging message, a discovery message, or a control message.

32. The apparatus of claim 22, wherein the state controller is further configured to:

transition from the third operational state to the first operational state if a signal is received; and

transition from the second operational state to the first operational state if a signal is received.

33. The apparatus of claim 32, wherein each signal comprises a packet, a data packet, a paging message, a discovery message, or a control message.

34. The apparatus of claim 22, further comprising a timing controller configured to correlate periodic timing of the scanning during the third operational state with periodic timing of the scanning during the second operational state.

35. The apparatus of claim 34, wherein the periodic timing of the scanning during the third operational state and the periodic timing of the scanning during the second operational state are based on a common timing offset.

36. The apparatus of claim 22, further comprising a transmitter configured to transmit a response signal if a signal is received by the receiver during any of the channel scanning, wherein the response signal comprises an acknowledgement message or a response to a paging message.

37. The apparatus of claim 22, wherein:

the receiver is further configured to receive a paging message; and

the apparatus further comprises a transmitter configured to transmit a response to the paging message, wherein timing of the transmission of the response provides an indication of timing of the scanning during the second operational state, the third operational state, or the second and third operational states.

38. The apparatus of claim 22, wherein:

the receiver is further configured to receive a paging message; and

the apparatus further comprises a transmitter configured to transmit a response to the paging message, wherein the response includes an indication of timing of the scanning during the second operational state, the third operational state, or the second and third operational states.

39. The apparatus of claim 22, wherein:

the receiver is further configured to receive paging messages from a plurality of nodes within a defined period of time; and

the apparatus further comprises a transmitter configured to transmit a single response to the paging messages.

40. The apparatus of claim 39, wherein the transmission of the single response comprises broadcasting the single response over a channel that is common to the plurality of nodes.

41. The apparatus of claim 39, wherein a length of a preamble of the single response is based on relative scanning period times associated with the plurality of nodes.

42. The apparatus of claim 22, wherein at least one of the first duty cycle, the second duty cycle, or the third duty cycle is based on a node type.

43. An apparatus for wireless communication, comprising:

means for scanning a channel according to a first duty cycle during a first operational state;

means for scanning the channel according to a second duty cycle during a second operational state, wherein the second duty cycle is lower than the first duty cycle; and

means for scanning the channel according to a third duty cycle during a third operational state, wherein the third duty cycle is lower than the second duty cycle; and

wherein the channel scanning according to the second duty cycle comprises periodically scanning at times based on a first time interval, the channel scanning according to the third duty cycle comprises periodically scanning at times based on a second time interval, and the second time interval is longer than the first time interval.

44. The apparatus of claim 43, wherein the first operational state comprises an active state, the second operational state comprises a periodic state, and the third operational state comprises a standby state.

45. The apparatus of claim 43, wherein the channel scanning according to the first duty cycle comprises continuously scanning the channel.

46. The apparatus of claim 43, wherein:

the channel scanning according to the first duty cycle comprises periodically scanning at times based on a third time interval; and

the third time interval is shorter than the first time interval.

47. The apparatus of claim 46, wherein the third time interval corresponds to a scanning rate that is high enough to capture a preamble of an asynchronous packet.

48. The apparatus of claim 46, wherein a duration of any one of the first time interval, the second time interval, or the third time interval is based on at least one of:

a size of a packet preamble, clock drift, or a probability of not detecting a packet.

49. The apparatus of claim 43, further comprising:

means for transitioning from the first operational state to the second operational state if a signal is not received during a first timeout period; and

means for transitioning from the second operational state to the third operational state if a signal is not received during a second timeout period.

50. The apparatus of claim 49, wherein each signal comprises a packet, a data packet, a paging message, a discovery message, or a control message.

51. The apparatus of claim 43, further comprising:

means for transitioning from the first operational state to the second operational state if a signal is not received during a first defined quantity of successive channel scans; and

means for transitioning from the second operational state to the third operational state if a signal is not received during a second defined quantity of successive channel scans.

52. The apparatus of claim 51, wherein each signal comprises a packet, a data packet, a paging message, a discovery message, or a control message.

53. The apparatus of claim 43, further comprising:

means for transitioning from the third operational state to the first operational state if a signal is received; and

means for transitioning from the second operational state to the first operational state if a signal is received.

54. The apparatus of claim 53, wherein each signal comprises a packet, a data packet, a paging message, a discovery message, or a control message.

55. The apparatus of claim 43, further comprising means for correlating periodic timing of the scanning during the third operational state with periodic timing of the scanning during the second operational state.

56. The apparatus of claim 55, wherein the periodic timing of the scanning during the third operational state and the periodic timing of the scanning during the second operational state are based on a common timing offset.

57. The apparatus of claim 43, further comprising means for transmitting a response signal if a signal is received during any of the channel scanning, wherein the response signal comprises an acknowledgement message or a response to a paging message.

58. The apparatus of claim 43, further comprising:

means for receiving a paging message; and

means for transmitting a response to the paging message, wherein timing of the transmission of the response provides an indication of timing of the scanning during the second operational state, the third operational state, or the second and third operational states.

59. The apparatus of claim 43, further comprising:

means for receiving a paging message; and

means for transmitting a response to the paging message, wherein the response includes an indication of timing of the scanning during the second operational state, the third operational state, or the second and third operational states.

60. The apparatus of claim 43, further comprising:

means for receiving paging messages from a plurality of nodes within a defined period of time; and

means for transmitting a single response to the paging messages.

61. The apparatus of claim 60, wherein the transmission of the single response comprises broadcasting the single response over a channel that is common to the plurality of nodes.

62. The apparatus of claim 60, wherein a length of a preamble of the single response is based on relative scanning period times associated with the plurality of nodes.

63. The apparatus of claim 43, wherein at least one of the first duty cycle, the second duty cycle, or the third duty cycle is based on a node type.

64. A computer-program product for wireless communication, comprising:

non-transitory computer-readable medium comprising codes executable to;

scan a channel according to a first duty cycle during a first operational state;

scan the channel according to a second duty cycle during a second operational state, wherein the second duty cycle is lower than the first duty cycle; and

scan the channel according to a third duty cycle during a third operational state, wherein the third duty cycle is lower than the second duty cycle; and

wherein the channel scanning according to the second duty cycle comprises periodically scanning at times based on a first time interval, the channel scanning according to the third duty cycle comprises periodically scanning at times based on a second time interval, and the second time interval is longer than the first time interval.

65. A headset for wireless communication, comprising:

a receiver configured to;

scan a channel according to a first duty cycle during a first operational state;

scan the channel according to a second duty cycle during a second operational state, wherein the second duty cycle is lower than the first duty cycle; and

scan the channel according to a third duty cycle during a third operational state, wherein the third duty cycle is lower than the second duty cycle; and

wherein the channel scanning according to the second duty cycle comprises periodically scanning at times based on a first time interval, the channel scanning according to the third duty cycle comprises periodically scanning at times based on a second time interval, and the second time interval is longer than the first time interval; and

a transducer configured to provide an audio output based on data received via the receiver.

66. A watch for wireless communication, comprising:

a receiver configured to;

scan a channel according to a first duty cycle during a first operational state;

scan the channel according to a second duty cycle during a second operational state, wherein the second duty cycle is lower than the first duty cycle; and

scan the channel according to a third duty cycle during a third operational state, wherein the third duty cycle is lower than the second duty cycle; and

wherein the channel scanning according to the second duty cycle comprises periodically scanning at times based on a first time interval, the channel scanning according to the third duty cycle comprises periodically scanning at times based on a second time interval, and the second time interval is longer than the first time interval; and

a user interface configured to provide an indication based on data received via the receiver.

67. A sensing device for wireless communication, comprising:

a receiver configured to;

scan a channel according to a first duty cycle during a first operational state;

scan the channel according to a second duty cycle during a second operational state, wherein the second duty cycle is lower than the first duty cycle; and

scan the channel according to a third duty cycle during a third operational state, wherein the third duty cycle is lower than the second duty cycle; and

wherein the channel scanning according to the second duty cycle comprises periodically scanning at times based on a first time interval, the channel scanning according to the third duty cycle comprises periodically scanning at times based on a second time interval, and the second time interval is longer than the first time interval; and

a sensor configured to provide data to be transmitted during at least one of;

the first operational state, the second operational state, or the third operational state.