APPARATUS AND METHODS FOR CONTROLLING AN IDLE MODE IN A WIRELESS DEVICE

• US 20100067421A1
• Filed: 09/10/2009
• Published: 03/18/2010
• Est. Priority Date: 09/12/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Palanki, Ravi, Kadous, Tamer A., Ulupinar, Fatih, Gorokhov, Alexei Y.
• Granted Patent: US 8,576,760 B2
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 52/0206 in access points, e.g. base stations access point devices per se H04W88/08
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Apparatus and methods are disclosed for control of an idle mode in a wireless device. In particular, the idle mode duty cycle of a preamble transmission by an access point (AP), as an example, is variably or adaptively set in response to determined conditions of the wireless neighborhood. The conditions determined include the whether or not other wireless devices are present in the vicinity of sensing wireless device, as well as the state of those devices present, such as whether they are in an idle mode or an active mode.

Claims

1. A method for controlling an idle mode in a wireless device, the method comprising:

determining neighborhood conditions of the wireless device; and

adaptively setting an idle mode duty cycle used for at least preamble transmission by the wireless device responsive to the determined neighborhood conditions.

2. The method as defined in claim 1, wherein the preamble transmission includes at least one of a pilot waveform and a preamble payload configured to at least allow discovery of the wireless device by at least one other wireless device.

3. The method as defined in claim 2, wherein the preamble payload includes at least one of an identifier particular to the wireless device, system time, a configuration of the wireless device, an idle mode configuration, and information concerning the presence and state of neighboring wireless devices.

4. The method as defined in claim 2, wherein the pilot waveform includes a portion of an identifier particular to the wireless device.

5. The method as defined in claim 1, wherein determination of neighborhood conditions of the wireless device includes determining whether at least one other wireless device is in a vicinity of the wireless device.

6. The method as defined in claim 5, further comprising:

adaptively setting the idle mode duty cycle to a minimal duty cycle value still affording preamble transmission when no other wireless devices are determined to be in the vicinity of the wireless device.

7. The method as defined in claim 5, further comprising:

adaptively setting the idle mode duty cycle to a value greater than a minimal duty cycle value and less than an active idle mode duty cycle value when at least one

other wireless device operating in an idle mode is determined to be in the vicinity of the wireless device.

8. The method as defined in claim 5, adaptively setting the idle mode duty cycle to an active idle mode duty cycle when at least one other wireless device operating in an active mode is determined to be in the vicinity of the wireless device.

9. The method as defined in claim 8, wherein the value of the active idle mode duty cycle is variably determined in the wireless device based on whether the at least one other wireless device operating in an active mode is currently connected to the wireless device.

10. The method as defined in claim 1, wherein when determination of neighborhood conditions of the wireless device includes determining at least another wireless device operating in at least one of an active mode and an idle mode in a vicinity of the wireless device, the method further comprising:

transmitting the preamble transmission including a minimum distance value configured to communicate to at least one neighboring serving wireless device the presence of the at least another wireless device operating in active mode in the vicinity of the wireless device.

11. The method as defined in claim 10, the minimum distance value further comprising at least one of a:

a first minimum distance value configured for the at least another wireless device operating in an active mode;

a second minimum distance value configured for the at least another wireless device operating in an idle mode

12. The method as defined in claim 1, further comprising:

receiving a preamble transmission from another neighboring wireless device that includes a distance value configured to communicate distance information to at least one neighboring serving wireless device having at least one of an active wireless device and an idle wireless device operating in the coverage area of the neighboring serving wireless device; and

further adaptively setting the idle mode duty cycle based on the received distance value.

13. The method as defined in claim 12, further comprising:

incrementing the received distance value by a predetermined amount when no active wireless device is present in the coverage area of the wireless device; and

transmitting the incremented distance value to at least one further neighboring wireless device.

14. The method as defined in claim 1, further comprising:

alternating transmitting the preamble transmission by the wireless device and receiving preamble transmissions in the wireless device from at least one neighboring wireless device during respective idle mode cycles.

15. The method as defined in claim 1, further comprising:

transmitting the preamble transmission by spreading the transmission over at least a portion of frequencies in an available wireless bandwidth.

16. The method as defined in claim 1, further comprising:

transmitting the preamble transmission by spreading the transmission over all frequencies in an available wireless bandwidth.

17. The method as defined in claim 1, further comprising:

transmitting the preamble transmission in one or more particular time slots of a wireless transmission frame.

18. The method as defined in claim 17, wherein transmitting the preamble transmission in one or more particular time slots of a wireless transmission frame includes transmission of the preamble transmission staggered or randomized based on received preamble transmissions from at least one other wireless device.

19. The method as defined in claim 17, wherein transmitting the preamble transmission in one or more particular time slots of a wireless transmission frame includes selection of time slots based on a cellID of the wireless device.

20. The method as defined in claim 1, further comprising:

detecting timing information from at least one preamble transmission from at least one other wireless device; and

determining an earliest system time from the at least one preamble transmission and the system time of the wireless device based on predetermined criteria; and

slaving the system time of the wireless device to the determined earliest system

time.

21. The method as defined in claim 20, wherein the predetermined criteria includes giving priority to system times of another wireless device having active wireless devices in its vicinity over system times of another wireless device having idle wireless devices in its vicinity.

22. The method as defined in claim 1, further comprising:

determining neighborhood conditions of the wireless device includes;

determining a distance from the wireless device to an idle access terminal registered in a network based on at least one distance value received from at least one neighboring wireless device;

determining a priority class of the access terminal; and

further adaptively setting the idle mode duty cycle dependent on the determined distance and priority class.

23. The method as defined in claim 1, further comprising:

transmitting paging information within one of the preamble and a dedicated paging channel to at least one neighboring unwired access point, wherein the paging information communicates paging information concerning at least one access terminal registered in a network.

24. The method as defined in claim 1, further comprising:

determining neighborhood conditions includes determining the presence of at least one preamble demand signal from at least one neighboring wireless device; and

further adaptively setting the idle mode duty cycle based on the at least one preamble demand signal.

25. The method as defined in claim 24, further comprising:

sending a preamble in response to the preamble demand signal.

26. The method as defined in claim 1, wherein the wireless device comprises one of an unwired access point (AP), an unwired relay station (RS), and an access terminal (AT).

27. An apparatus for controlling an idle mode in a wireless device, the apparatus comprising:

means for determining neighborhood conditions of the wireless device; and

means for adaptively setting an idle mode duty cycle used for at least preamble transmission by the wireless device responsive to the determined neighborhood conditions.

28. The apparatus as defined in claim 27, wherein the means for determining neighborhood conditions of the wireless device is configured to determine whether at least one other wireless device is in a vicinity of the wireless device.

29. The apparatus as defined in claim 28, wherein the means for adaptively setting the idle mode duty cycle is configured to set the idle mode duty cycle to a minimal duty cycle value still affording preamble transmission when no other wireless devices are determined to be in the vicinity of the wireless device by the means for determining neighborhood conditions of the wireless device.

30. The apparatus as defined in claim 28, wherein the means for adaptively setting the idle mode duty cycle is configured to set the idle mode duty cycle to a value greater than a minimal duty cycle value and less than an active idle mode duty cycle value when at least one other wireless device operating in an idle mode is determined to be in the vicinity of the wireless device by the means for determining neighborhood conditions of the wireless device.

31. The apparatus as defined in claim 28, wherein the means for adaptively setting the idle mode duty cycle is configured to set the idle mode duty cycle to an active idle mode duty cycle when at least one other wireless device operating in an active mode is determined to be in the vicinity of the wireless device by the means for determining neighborhood conditions of the wireless device.

32. The apparatus as defined in claim 31, wherein the value of the active idle mode duty cycle is variably determined in the wireless device based on whether the at least one other wireless device operating in an active mode is currently connected to the wireless device.

33. The apparatus as defined in claim 27, further comprising:

means for transmitting the preamble transmission including a minimum distance value configured to communicate to at least one neighboring serving wireless device the presence of the at least another wireless device operating in active mode in the vicinity of the wireless device when the means for determining neighborhood conditions of the wireless device determines at least another wireless device operating in at least one of an active mode and an idle mode in a vicinity of the wireless device.

34. The apparatus as defined in claim 33, the minimum distance value further comprising at least one of a:

a first minimum distance value configured for the at least another wireless device operating in an active mode;

a second minimum distance value configured for the at least another wireless device operating in an idle mode

35. The apparatus as defined in claim 27, further comprising:

means for receiving a preamble transmission from another neighboring wireless device that includes a distance value configured to communicate distance information to at least one neighboring serving wireless device having at least one of an active wireless device and an idle device operating in the coverage area of the neighboring serving wireless device; and

the means for adaptively setting the idle mode duty cycle sets the duty cycle based on the received distance value.

36. The apparatus as defined in claim 35, further comprising:

means for incrementing the received distance value by a predetermined amount when no active wireless device is present in the coverage area of the wireless device; and

means for transmitting the incremented distance value to at least one further neighboring wireless device.

37. The apparatus as defined in claim 27, further comprising:

means for transmitting the preamble transmission in one or more particular time slots of a wireless transmission frame.

38. The apparatus as defined in claim 37, wherein transmitting the preamble transmission in one or more particular time slots of a wireless transmission frame includes transmission of the preamble transmission staggered or randomized based on received preamble transmissions from at least one other wireless device.

39. The apparatus as defined in claim 38, wherein transmitting the preamble transmission in one or more particular time slots of a wireless transmission frame includes selection of time slots based on a cellID of the wireless device.

40. The apparatus as defined in claim 27, further comprising:

means for detecting timing information from at least one preamble transmission from at least one other wireless device; and

means for determining an earliest system time from the at least one preamble transmission and the system time of the wireless device based on predetermined criteria; and

means for slaving the system time of the wireless device to the determined earliest system time.

41. The apparatus as defined in claim 27, further comprising:

the means for determining neighborhood conditions of the wireless device including;

means for determining a distance from the wireless device to an idle access terminal registered in a network based on at least one distance value received from at least one neighboring wireless device;

means for determining a priority class of the access terminal; and

the means for adaptively setting the idle mode duty cycle configured to set the duty cycle dependent on the determined distance and priority class.

42. The apparatus as defined in claim 27, further comprising:

means for determining neighborhood conditions includes determining the presence of at least one preamble demand signal from at least one neighboring wireless device; and

the means for adaptively setting the idle mode duty cycle configured to set the duty cycle based on the at least one send preamble demand signal.

43. An apparatus for controlling an idle mode in a wireless device, the apparatus comprising:

at least one processor configured to;

determine neighborhood conditions of the wireless device; and

adaptively set an idle mode duty cycle used for at least preamble transmission by the wireless device responsive to the determined neighborhood conditions; and

a memory configured to store instructions executable by the at least one processor.

44. The apparatus as defined in claim 43, wherein the preamble transmission includes at least one of a pilot waveform and a preamble payload configured to at least allow discovery of the wireless device by at least one other wireless device.

45. The apparatus as defined in claim 43, wherein when the processor is configured to determine whether at least one other wireless device is in a vicinity of the wireless device.

46. The apparatus as defined in claim 45, wherein when the processor is configured to set the idle mode duty cycle to a minimal duty cycle value still affording preamble transmission when no other wireless devices are determined to be in the vicinity of the wireless device.

47. The apparatus as defined in claim 45, wherein the processor is configured to set the idle mode duty cycle to a value greater than a minimal duty cycle value and less than an active idle mode duty cycle value when at least one other wireless device operating in an idle mode is determined to be in the vicinity of the wireless.

48. The apparatus as defined in claim 45, wherein the processor is configured to set the idle mode duty cycle to an active idle mode duty cycle when at least one other wireless device operating in an active mode is determined to be in the vicinity of the wireless device by the means for determining neighborhood conditions of the wireless device.

49. The apparatus as defined in claim 48, wherein the value of the active idle mode duty cycle is variably determined in the wireless device based on whether the at least one other wireless device operating in an active mode is currently connected to the wireless device.

50. The apparatus as defined in claim 43, wherein the processor is further configured to:

configure the preamble transmission including a minimum distance value configured to communicate to at least one neighboring serving wireless device the presence of the at least another wireless device operating in active mode in the vicinity of the wireless device when the means for determining neighborhood conditions of the wireless device determines at least another wireless device operating in at least one of an active mode and an idle mode in a vicinity of the wireless device.

51. The apparatus as defined in claim 43, further comprising:

a receiver configured to receive a preamble transmission from another neighboring wireless device that includes a distance value configured to communicate distance information to at least one neighboring serving wireless device having one of an active wireless device and an idle wireless device operating in the coverage area of the neighboring serving wireless device; and

the processor further configured to adaptively set the idle mode duty cycle based on the received distance value.

52. The apparatus as defined in claim 51, wherein the processor is further configured to:

increment the received distance value by a predetermined amount when no active wireless device is present in the coverage area of the wireless device; and

direct transmission of the incremented distance value by a transmitter to at least one further neighboring wireless device.

53. The apparatus as defined in claim 43, wherein the processor is further configured to direct alternating transmission of the preamble transmission by a transmitter in the wireless device and reception of preamble transmissions by a receiver in the wireless device from at least one neighboring wireless device during respective idle mode cycles.

54. The apparatus as defined in claim 43, wherein the processor is further configured to direct transmission of the preamble transmission by a transmitter in one or more particular time slots of a wireless transmission frame.

55. The apparatus as defined in claim 43, wherein the processor is further configured to:

detect timing information from at least one preamble transmission from at least one other wireless device; and

determine an earliest system time from the at least one preamble transmission and the system time of the wireless device based on predetermined criteria; and

slave the system time of the wireless device to the determined earliest system time.

56. The apparatus as defined in claim 55, wherein the predetermined criteria includes giving priority to system times of another wireless device having active wireless devices in its vicinity over system times of another wireless device having idle wireless devices in its vicinity.

57. The apparatus as defined in claim 43, wherein the processor is further configured to:

determine a distance from the wireless device to an idle access terminal registered in a network based on at least one distance value received from at least one neighboring wireless device;

determine a priority class of the access terminal; and

adaptively set the idle mode duty cycle dependent on the determined distance and priority class.

58. The apparatus as defined in claim 43, wherein the processor is further configured to direct transmission paging information within one of the preamble transmission and a dedicated paging channel to at least one neighboring unwired access point, wherein the paging information communicates paging information concerning at least one access terminal registered in a network.

59. The apparatus as defined in claim 43, wherein the processor is further configured to:

determine neighborhood conditions including determining the presence of at least one preamble demand signal from at least one neighboring wireless device; and

adaptively set the idle mode duty cycle based on the at least one send preamble demand signal.

60. The apparatus as defined in claim 59, wherein the processor is further configured to direct sending a preamble in response to the preamble demand signal.

61. A computer program product comprising:

computer-readable medium comprising;

code for causing a computer to determine neighborhood conditions of a wireless device; and

code for causing a computer to adaptively set an idle mode duty cycle used for at least preamble transmission by the wireless device responsive to the determined neighborhood conditions.

62. The computer program product as defined in claim 61, wherein the code for causing a computer to determine the neighborhood conditions of the wireless device includes code for causing the computer to determine to determine whether at least one other wireless device is in a vicinity of the wireless device.

63. The computer program product as defined in claim 62, wherein the code for causing a computer to adaptively set the idle mode duty cycle sets the idle mode duty cycle to a minimal duty cycle value still affording preamble transmission when no other wireless devices are determined to be in the vicinity of the wireless device.

64. The computer program product as defined in claim 62, wherein the code for causing a computer to adaptively set the idle mode duty cycle sets the idle mode duty cycle to a value greater than a minimal duty cycle value and less than an active idle mode duty cycle value when at least one other wireless device operating in an idle mode is determined to be in the vicinity of the wireless.

65. The computer program product as defined in claim 62, the code for causing a computer to adaptively set the idle mode duty cycle sets the idle mode duty cycle to an active idle mode duty cycle when at least one other wireless device operating in an active mode is determined to be in the vicinity of the wireless device by the means for determining neighborhood conditions of the wireless device.

66. The computer program product as defined in claim 62, wherein the code for causing a computer to determine neighborhood conditions of the wireless device includes code for determining at least another wireless device operating in an active mode in a vicinity of the wireless device, and

the computer-readable medium further comprising:

code for causing a computer to transmit the preamble transmission including a minimum distance value configured to communicate to at least one neighboring serving wireless device the presence of the at least another wireless device operating in active mode in the vicinity of the wireless device when the code for causing a computer to determine neighborhood conditions of the wireless device determines at least another wireless device operating at least one of an active mode and an idle mode in the vicinity of the wireless device.

67. The computer program product as defined in claim 61, wherein the computer-readable medium further comprises:

code for causing a computer to receive a preamble transmission from another neighboring wireless device that includes a distance value configured to communicate distance information to at least one neighboring serving wireless device having at least one of an active wireless device and an idle wireless device operating in the coverage area of the neighboring serving wireless device; and

code for causing a computer to further adaptively set the idle mode duty cycle based on the received distance value.

68. The computer program product as defined in claim 61, wherein the computer-readable medium further comprises:

code for causing a computer to cause transmission of the preamble transmission in one or more particular time slots of a wireless transmission frame.

69. The computer program product as defined in claim 61, wherein the code for causing a computer to determine neighborhood conditions of the wireless device includes:

code for causing a computer to determine a distance from the wireless device to an idle access terminal registered in a network based on at least one distance value received from at least one neighboring wireless device;

code for causing a computer to determine a priority class of the access terminal; and

code for causing a computer to further adaptively set the idle mode duty cycle dependent on the determined distance and priority class.