Method and system for a data transmission in a communication system

• US 7,139,274 B2
• Filed: 12/06/2002
• Issued: 11/21/2006
• Est. Priority Date: 08/23/2002
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Bhushan, Naga, Attar, Rashid Ahmed
• Primary Examiner(s): Rao, Seema S.
• Assistant Examiner(s): Shew, John
• Application Number:
  US10/313,553
• Publication Number:
  US 20040037291A1
• Time in Patent Office: 1,446 Days
• Field of Search: 370/252, 370/253, 370/282, 370/310.1, 370/310.2, 370/311, 370/317, 370/318, 370/320, 370/322, 370/328, 370/329, 370/331, 370/332, 370/335, 370/342, 370/395.4, 370/395.41, 370/395.42, 370/395.43, 370/441, 370/458, 370/491, 370/500, 455/69, 455/114.2, 455/127.1, 455/127.2, 455/135, 455/500, 455/507, 455/509, 455/517
• US Class Current: 370/395.4
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/16 Deriving transmission power values from another channel
• CPC Class Codes: H04W 52/26 using transmission rate or quality of service QoS [Quality of Service]
• CPC Class Codes: H04W 52/48 during retransmission after error or non-acknowledgment
• CPC Class Codes: H04W 74/0891 for synchronized access

Abstract

Methods and apparatus for a data transmission in a communication system are disclosed. Each of a subset of plural access terminals desiring to transmit user data in an interval transmits a request to transmit in the interval to an access network. The access network makes a decision to schedule at least one of the subset of the plural access terminals to transmit in the interval in accordance with the request. At least one access point of the access network transmits the decision to the plural access terminals.

Claims

1. A method for scheduling user data transmission from plural access terminals to an access network comprising at least one access point and a controller, the method comprising:

determining at each of a subset of access terminals an opportunity level to transmit data for an interval, the opportunity level indicating a reverse link channel condition;

transmitting from each of the subset of the plural access terminals a request to transmit data in the interval, the request including the opportunity level;

making a decision at the access network to schedule at least one of the subset of the plural access terminals to transmit data in the interval in accordance with the request; and

transmitting from the at least one access point the decision to the plural access terminals.

2. The method as claimed in claim 1 wherein the transmitting from each of a subset of the plural access terminals a request to transmit in an interval comprises:

transmitting from each of a subset of the plural access terminals in connected state a request to transmit in an interval.

3. The method as claimed in claim 1 wherein the transmitting from each of a subset of the plural access terminals a request to transmit in an interval comprises:

determining at each of a subset of access terminals an opportunity level for a pre-determined interval; and

wherein the transmitting comprises transmitting the opportunity level.

4. The method as claimed in claim 1 wherein the making a decision at the access network to schedule at least one of the subset of the plural access terminals to transmit in the interval in accordance with the request comprises:

scheduling at least one of the subset of the plural access terminals.

5. The method as claimed in claim 1 wherein the making a decision at the access network to schedule at least one of the subset of the plural access terminals to transmit in the interval in accordance with the request comprises:

making a decision at the access network controller.

6. The method as claimed in claim 1 wherein the making a decision at the access network to schedule at least one of the subset of the plural access terminals to transmit in the interval in accordance with the request comprises:

making a decision at each of the at least one access points that received the request to transmit.

7. The method as claimed in claim 1 wherein the transmitting from the at least one access point the decision to the plural access terminals comprises:

transmitting from each of the at least one access point that is a serving access point for the requesting access terminal.

8. The method as claimed in claim 1 further comprising:

transmitting user data from the plural access terminals in accordance with the decision.

9. A method for scheduling user data transmission from plural access terminals to an access network comprising at least one access point and a controller, the method comprising:

transmitting from each of a subset of the plural access terminals a request to transmit data in an interval;

making a decision at the access network to schedule at least one of the subset of the plural access terminals to transmit data in the interval in accordance with the request;

transmitting from the at least one access point the decision to the plural access terminals;

wherein the transmitting from each of a subset of the plural access terminals the request to transmit in the interval comprises;

determining at each of a subset of access terminals an opportunity level for an interval; and

transmitting the opportunity level and an interval indicator;

wherein the determining at each of a subset of access terminals an opportunity level for an interval comprises;

determining the opportunity level in accordance with an instantaneous quality metric of a reverse link channel in the interval, an average quality metric of the reverse link channel, and a function.

10. The method as claimed in claim 9 wherein the determining the opportunity level in accordance with an instantaneous quality metric of a reverse link channel in the interval, an average quality metric of the reverse link channel, and a function comprises:

determining the opportunity level in accordance with an instantaneous quality metric of a reverse link channel in the interval, an average quality metric of the reverse link channel, and an impatience function.

11. The method as claimed in claim 10 wherein the determining impatience function is carried out in accordance with factors selected from the group consisting of:

a maximum acceptable transmission delay;

a number of packets in a queue at the access terminal; and

an average throughput of the reverse link.

12. The method as claimed in claim 11 wherein the determining impatience function is carried out in accordance with the factors modified by a user'"'"'s attribute.

13. The method as claimed in claim 9 wherein the determining the opportunity level in accordance with an instantaneous quality metric of a reverse link channel in the interval, an average quality metric of the reverse link channel, and a function comprises:

determining the opportunity level in accordance with an instantaneous quality metric of a reverse link pilot channel in the pre-determined interval, an average quality metric of the reverse link pilot channel, and a function.

14. A method for scheduling user data transmission from plural access terminals to an access network comprising at least one access point and a controller, the method comprising:

transmitting from each of a subset of the plural access terminals a request to transmit data in an interval;

the request including an opportunity level indicating a reverse link channel condition;

making a decision at the access network to schedule at least one of the subset of the plural access terminals to transmit data in the interval in accordance with the request; and

transmitting from the at least one access point the decision to the plural access terminals;

wherein the transmitting from the at least one access point the decision to the plural access terminals comprises;

transmitting a signal representing an energy value to each of the plural access terminals permitted to transmit; and

transmitting a signal representing zero energy value to each of the plural access terminals denied to transmit.

15. The method as claimed in claim 14 wherein the transmitting from each of a subset of the plural access terminals a request to transmit in an interval comprises:

determining at each of a subset of access terminals an opportunity level for an interval; and

transmitting the opportunity level and an interval indicator.

16. The method as claimed in claim 15 wherein the making a decision at the access network to schedule at least one of the subset of the plural access terminals to transmit in the interval in accordance with the request comprises:

giving precedence to access terminals reporting the highest opportunity level;

giving a precedence to the access terminals with lower transmitted throughput when several access terminals report identical opportunity level; and

scheduling the access terminals at random when the precedence could not be established in accordance with the opportunity level.

17. The method as claimed in claim 14 wherein the transmitting a signal representing an energy value to each of the plural access terminal permitted to transmit comprises:

transmitting a signal representing a first energy value to each of the plural access terminals permitted to transmit; and

transmitting a signal representing a second energy value to each of the plural access terminals permitted to re-transmit.

18. A method for scheduling user data transmission from plural access terminals to an access network comprising at least one access point and a controller, the method comprising:

transmitting from each of a subset of the plural access terminals a request to transmit data in an interval;

the request including an opportunity level indicating a reverse link channel condition;

making a decision at the access network to schedule at least one of the subset of the plural access terminals to transmit data in the interval in accordance with the request; and

transmitting from the at least one access point the decision to the plural access terminals;

transmitting user data from the plural access terminals in accordance with the decision;

receiving at the at least one of the access points user data from each of the plural access terminals permitted to transmit;

transmitting from a serving access point a signal representing a first energy value to each of the plural access terminals whose user data has been correctly received when the access terminal is next permitted to transmit; and

transmitting from a serving access point a signal representing a second energy value to each of the plural access terminals whose user data has not been correctly received when the access terminal is next permitted to transmit.

19. The method as claimed in claim 18 further comprising:

transmitting from a non-serving access point a signal representing a first energy value to each of the plural access terminals whose user data has been correctly received; and

transmitting from a non-serving access point a signal representing a second energy value to each of the plural access terminals whose user data has not been correctly received.

20. The method as claimed in claim 18 further comprising:

storing incorrectly received user data; and

combining the stored user data with retransmitted user data.

21. The method as claimed in claim 18 wherein the receiving at the at least one of the access points user data from each of the plural access terminals permitted to transmit comprises:

receiving at one or more sectors of the at least one of the access points user data from each of the plural access terminals permitted to transmit.

22. A method for scheduling user data transmission over a reverse link at an access network comprising at least one access point and a controller, the method comprising:

receiving at the access network at least one request to transmit in an interval, the request comprising an opportunity level indicating a reverse link channel condition;

making a decision at the access network to schedule at least one transmission in the interval in accordance with the at least one request; and

transmitting from the at least one access point the decision.

23. The method as claimed in claim 22 wherein the receiving at the access network at least one request to transmit in an interval comprises:

receiving at the access network at least one opportunity level and at least one interval indicator.

24. The method as claimed in claim 22 wherein the receiving at the access network at least one request to transmit in an interval comprises:

receiving at the access network at least one opportunity level.

25. The method as claimed in claim 22 wherein the making a decision at the access network to schedule at least one transmission in the interval in accordance with the at least one request comprises:

giving precedence to at least one request that contains the highest opportunity level;

giving a precedence to at least one request from an access terminal with lower transmitted throughput when several of the at least one request contain identical opportunity level; and

scheduling the at least one transmission at random when the precedence could not be established in accordance with the opportunity level.

26. The method as claimed in claim 22 the making a decision at the access network to schedule at least one transmission in the interval in accordance with the at least one request comprises:

scheduling at least one transmission.

27. The method as claimed in claim 22 wherein the making a decision at the access network to schedule at least one transmission in the interval in accordance with the at least one request comprises:

making a decision at the access network controller.

28. The method as claimed in claim 22 wherein the making a decision at the access network to schedule at least one transmission in the interval in accordance with the at least one request comprises:

making a decision at each of the at least one access points that received the request.

29. The method as claimed in claim 22 wherein the transmitting from the at least one access point the decision comprises:

transmitting from each of the at least one access point that is a serving access point the decision.

30. A method for scheduling at an access network comprising at least one access point and a controller user data transmission over a reverse link, the method comprising:

receiving at the access network at least one request to transmit in an interval;

the request including an opportunity level indicating a reverse link channel condition;

making a decision at the access network to schedule at least one transmission in the interval in accordance with the at least one request; and

transmitting from the at least one access point the decision wherein the transmitting from the at least one access point the decision comprises;

transmitting a signal representing an energy value in response to those of the at least one request to transmit that were granted; and

transmitting a signal representing zero energy value in response to those of the at least one request to transmit that were denied.

31. The method as claimed in claim 30 wherein the transmitting a signal representing an energy value in response to those of the at least one request to transmit that were granted comprises:

transmitting a signal representing a first energy value in response to those of the at least one request to transmit that were granted permission to transmit; and

transmitting a signal representing a second energy value in response to those of the at least one request to transmit that were granted permission to re-transmit.

32. A method for scheduling at an access network comprising at least one access point and a controller user data transmission over a reverse link, the method comprising:

receiving at the access network at least one request to transmit in an interval;

the request including an opportunity level indicating a reverse link channel condition;

making a decision at the access network to schedule at least one transmission in the interval in accordance with the at least one request;

transmitting from the at least one access point the decision;

receiving at the at least one of the access point user data in response to each permission to transmit;

transmitting from a serving access point a signal representing a first energy value in response to each correctly received user data as the decision; and

transmitting from a serving access point a signal representing a second energy value in response to each incorrectly received user data the decision.

33. The method as claimed in claim 32 further comprising:

transmitting from a non-serving access point a signal representing a first energy value in response to each correctly received user data; and

transmitting from a non-serving access point a signal representing a second energy value in response to each correctly received user data.

34. The method as claimed in claim 32 further comprising:

storing incorrectly received user data; and

combining the stored user data with re-transmitted user data.

35. The method as claimed in claim 32 wherein the receiving at the at least one of the access point user data in response to each permission to transmit comprises:

receiving at least one sector of the at least one of the access point user data in response to each permission to transmit.

36. A method for scheduling user data transmission from plural access terminals, the method comprising:

transmitting from each of a subset of the plural access terminals a request to transmit in an interval; and

receiving at the at least one of the plural access terminals a scheduling decision;

wherein the transmitting from each of a subset of the plural access terminals a request to transmit in an interval comprises;

determining at each of a subset of access terminals an opportunity level for an interval;

and transmitting the opportunity level and the interval indicator;

wherein the determining at each of a subset of access terminals an opportunity level for an interval comprises;

determining the opportunity level in accordance with an instantaneous quality metric of a reverse link channel in the interval, an average quality metric of the reverse link channel, and an function.

37. The method as claimed in claim 36 wherein the determining the opportunity level in accordance with an instantaneous quality metric of a reverse link channel in the interval, an average quality metric of the reverse link channel, and a function comprises:

determining the opportunity level in accordance with an instantaneous quality metric of a reverse link channel in the interval, an average quality metric of the reverse link channel, and an impatience function.

38. The method as claimed in claim 37 wherein the determining impatience function is carried out in accordance with factors selected from the group consisting of:

a maximum acceptable transmission delay;

a number of packets in a queue at the access terminal; and

an average throughput of the reverse link.

39. The method as claimed in claim 38 the determining impatience function is carried out in accordance with the factors modified by a user'"'"'s attribute.

40. The method as claimed in claim 36 wherein the determining the opportunity level in accordance with an instantaneous quality metric of a reverse link channel in the determined interval, an average quality metric of the reverse link channel, and a function comprises:

determining the opportunity level in accordance with an instantaneous quality metric of a reverse link pilot channel in the pre-determined interval, an average quality metric of the reverse link pilot channel, and a function.

41. A method for scheduling user data transmission from plural access terminals, the method comprising:

transmitting from each of a subset of the plural access terminals a request to transmit in an interval;

the request including an opportunity level indicating a reverse link channel condition; and

receiving at the at least one of the plural access terminals a scheduling decision;

wherein the receiving at the at least one of the plural access terminals a scheduling decision comprises;

receiving a signal representing an energy value at those of the at least one of the plural access terminals permitted to transmit; and

receiving a signal representing zero energy value at those of the at least one of the plural access terminals denied to transmit.

42. The method as claimed in claim 41 wherein the receiving a signal representing an energy value at those of the at least one of the plural access terminals permitted to transmit comprises:

receiving a signal representing a first energy value at those of the at least one of the plural access terminals permitted to transmit; and

receiving a signal representing a second energy value at those of the at least one of the plural access terminals permitted to re-transmit.

43. A system for scheduling user data transmission over a reverse link, the system comprising:

plural access terminals configured to transmit a request to transmit in an interval, the request comprising an opportunity level indicating a reverse link channel condition; and

an access network comprising at least one access point and a controller, the access network configured to;

receive from each of a subset of the plural terminals request to transmit in an interval;

make a decision to schedule at least one of the subset of the plural access terminals to transmit in the interval in accordance with the request; and

transmit from the at least one access point the decision to the plural access terminals.

44. The system as claimed in claim 43 wherein the plural access terminals are configured to transmit a request to transmit in an interval when the plural access terminals are in connected state.

45. The system as claimed in claim 43 wherein the plural access terminals are configured to:

determine an opportunity level for an interval; and

transmit the opportunity level and the interval indicator.

46. The system as claimed in claim 43 wherein the plural access terminals are configured to:

determine an opportunity level for an pre-determined interval; and

transmit the opportunity level.

47. The system as claimed in claims 45 or 46 wherein the access network is configured to:

give precedence to the access terminals reporting the highest opportunity level;

give a precedence to the access terminals with lower transmitted throughput when several access terminals report identical opportunity level; and

schedule the access terminals at random when the precedence could not be established in accordance with the opportunity level.

48. The system as claimed in claim 43 wherein the access network is configured to:

schedule at least one of the subset of the plural access terminals.

49. The system as claimed in claim 43 wherein the access network is configured to:

make a decision at the access network controller.

50. The system as claimed in claim 43 wherein the access network is configured to:

make a decision at each of the at least one access points that received the request to transmit.

51. The system as claimed in claim 43 wherein the access network is configured to:

transmit from each of the at least one access point that is a serving access point for the requesting access terminal the decision.

52. The system as claimed in claim 43 wherein the plural access terminals are further configured to:

transmit user data in accordance with the scheduling decision.

53. A system for scheduling user data transmission over a reverse link, the system comprising:

plural access terminals configured to transmit a request to transmit in an interval; and

an access network comprising at least one access point and a controller, the access network configured to;

receive from each of a subset of the plural terminals request to transmit in an interval;

make a decision to schedule at least one of the subset of the plural access terminals to transmit in the interval in accordance with the request; and

transmit from the at least one access point the decision to the plural access terminals;

wherein the plural access terminals are configured to;

determine the opportunity level in accordance with an instantaneous quality metric of a reverse link channel in the interval, an average quality metric of the reverse link channel, and a function.

54. The system as claimed in claim 53 wherein the plural access terminals are configured to:

determine the opportunity level in accordance with an instantaneous quality metric of a reverse link channel in the interval, an average quality metric of the reverse link channel, and an impatience function.

55. The system as claimed in claim 54 the plural access terminals are configured to determine the impatience function in accordance with factors selected from the group consisting of:

a maximum acceptable transmission delay;

a number of packets in a queue at the access terminal; and

an average throughput of the reverse link.

56. The system as claimed in claim 55 wherein the plural access terminals are configured to determine the impatience function in accordance with the factors modified by a user'"'"'s attribute.

57. The system as claimed in claim 53 wherein the plural access terminals are configured to:

determine the opportunity level in accordance with an instantaneous quality metric of a reverse link pilot channel in the pre-determined interval, an average quality metric of the reverse link pilot channel, and a function.

58. An system for scheduling user data transmission over a reverse link, the system comprising:

plural access terminals configured to transmit a request to transmit in an interval; and

an access network comprising at least one access point and a controller, the access network configured to;

receive from each of a subset of the plural terminals request to transmit in an interval;

the request including an opportunity level indicating a reverse link channel condition;

make a decision to schedule at least one of the subset of the plural access terminals to transmit in the interval in accordance with the request; and

transmit from the at least one access point the decision to the plural access terminals wherein the access network is configured to;

transmit a signal representing an energy value to each of the plural access terminals permitted to transmit; and

transmit a signal representing zero energy value to each of the plural access terminals denied to transmit.

59. The system as claimed in claim 58 wherein the access network is configured to:

transmit a signal representing a first energy value to each of the plural access terminals permitted to transmit; and

transmit a signal representing a second energy value to each of the plural access terminals permitted to re-transmit.

60. A system for scheduling user data transmission over a reverse link, the system comprising:

plural access terminals configured to transmit a request to transmit in an interval; and

an access network comprising at least one access point and a controller, the access network configured to;

receive from each of a subset of the plural terminals request to transmit in an interval;

the request including an opportunity level indicating a reverse link channel condition;

make a decision to schedule at least one of the subset of the plural access terminals to transmit in the interval in accordance with the request; and

transmit from the at least one access point the decision to the plural access terminals;

wherein the plural access terminals are further configured to;

transmit user data in accordance with the scheduling decision;

wherein the access network is further configured to;

receive at the at least one of the access points user data from each of the plural access terminals permitted to transmit;

transmit from a serving access point a signal representing a first energy value to each of the plural access terminals whose user data has been correctly received when the access terminal is next permitted to transmit; and

transmit from a serving access point a signal representing a second energy value to each of the plural access terminals whose user data has not been correctly received when the access terminal is next permitted to transmit.

61. The system as claimed in claim 60 wherein the access network is further configured to:

transmit from a non-serving access point a signal representing a first energy value to each of the plural access terminals whose user data has been correctly received when the access terminal is next permitted to transmit; and

transmit from a non-serving access point a signal representing a second energy value to each of the plural access terminals whose user data has not been correctly received when the access terminal is next permitted to transmit.

62. The system as claimed in claim 60 the access network is further configured to:

store incorrectly received user data; and

combine the stored user data with retransmitted user data.

63. The system as claimed in claim 60 wherein the access network is further configured to

receive at least one sector of the at least one of the access points user data from each of the plural access terminals permitted to transmit.

64. An access network for scheduling user data transmission over a reverse link, the access network comprising:

at least one access point and a controller, the access network configured to;

receive at least one request to transmit in an interval, the request comprising an opportunity level indicating a reverse link channel condition;

make a decision to schedule at least one transmission in the interval in accordance with the at least one request; and

transmit from the at least one access point the decision.

65. The access network as claimed in claim 64 wherein the access network is configured to:

receive at least one opportunity level and at least one interval indicator.

66. The access network as claimed in claim 64 wherein the access network is configured to:

receive at least one opportunity level.

67. The access network as claimed in claim 64 wherein the access network is configured to:

give precedence to at least one request that contains the highest opportunity level;

give a precedence to at least one request from an access terminal with lower transmitted throughput when several of the at least one request contain identical opportunity level; and

schedule the at least one transmission at random when the precedence could not be established in accordance with the opportunity level.

68. The access network as claimed in claim 64 the access network is configured to:

schedule at least one transmission.

69. The access network as claimed in claim 64 wherein the access network is configured to:

make a decision at the access network controller.

70. The access network as claimed in claim 64 the access network is configured to:

make a decision at each of the at least one access points that received the request.

71. The access network as claimed in claim 64 wherein the access network is configured to:

transmit from each of the at least one access point that is a serving access point the decision.

72. An access network for scheduling user data transmission over a reverse link, the access network comprising:

at least one access point and a controller, the access network configured to;

receive at least one request to transmit in an interval;

the request including an opportunity level indicating a reverse link channel condition;

make a decision to schedule at least one transmission in the interval in accordance with the at least one request; and

transmit from the at least one access point the decision;

wherein the access network is configured to;

transmit a signal representing an energy value in response to those of the at least one request to transmit that were granted; and

transmit a signal representing zero energy value in response to those of the at least one request to transmit that were denied.

73. The access network as claimed in claim 72 wherein the access network is configured to:

transmit a signal representing a first energy value in response to those of the at least one request to transmit that were granted permission to transmit; and

transmit a signal representing a second energy value in response to those of the at least one request to transmit that were granted permission to re-transmit.

74. An access network for scheduling user data transmission over a reverse link, the access network comprising:

at least one access point and a controller, the access network configured to;

receive at least one request to transmit in an interval;

the request including an opportunity level indicating a reverse link channel condition;

make a decision to schedule at least one transmission in the interval in accordance with the at least one request; and

transmit from the at least one access point the decision;

wherein the access network is further configured to;

receive at the at least one of the access point user data in response to each permission to transmit;

transmit from a serving access point a signal representing a first energy value in response to each correctly received user data as the decision; and

transmit from a serving access point a signal representing a second energy value in response to each incorrectly received user data the decision.

75. The access network as claimed in claim 74 wherein the access network is further configured to:

transmit from a non-serving access point a signal representing a first energy value in response to each correctly received user data; and

transmit from a non-serving access point a signal representing a second energy value in response to each correctly received user data.

76. The access network as claimed in claim 74 wherein the access network is further configured to:

store incorrectly received user data; and

combine the stored user data with re-transmitted user data.

77. The access network as claimed in claim 74 wherein the access network is further configured to:

receive at least one sector of the at least one of the access point user data in response to each permission to transmit.

78. An access terminal configured to:

determine an opportunity level for a pre-determined interval;

transmit the opportunity level in a request to transmit data in an interval; and

receive a scheduling decision;

wherein the access terminal is configured to;

determine the opportunity level in accordance with an instantaneous quality metric of a reverse link pilot channel in the pre-determined interval, an average quality metric of the reverse link pilot channel, and a function.

79. An access terminal being configured to:

transmit a request to transmit data in an interval;

the request including an opportunity level indicating a reverse link channel condition;

receive a scheduling decision;

determine that a permission to transmit was granted when the received scheduling decision represents an energy value; and

determine that a permission to transmit was denied when the received scheduling decision represents zero energy value.

80. The access terminal as claimed in claim 79 wherein the access terminal is configured to:

determine that a permission to transmit was granted when the received scheduling decision represents a first energy value; and

determine that a permission to re-transmit was granted when the received scheduling decision represents a second energy value.

81. An access terminal being configured to:

transmit a request to transmit data in an interval;

the request including an opportunity level indicating a reverse link channel condition;

receive a scheduling decision transmit user data in accordance with the scheduling decision;

receive a signal representing an energy value;

determine that a permission to transmit was granted and that previously transmitted user data has been correctly received when a signal representing a first energy value was received from a serving access terminal; and

determine that a permission to re-transmit previously transmitted user data has been granted when a signal representing a second energy value was received from a serving access terminal.

82. The access terminal as claimed in claim 81 wherein the access terminal is configured to:

determine that previously transmitted user data has been correctly received when a signal representing a first energy value was received from a non-serving access terminal; and

determine that previously transmitted user data has been incorrectly received when a signal representing a second energy value was received from a non-serving access terminal.

83. A system for scheduling user data transmission from plural access terminals to an access network comprising at least one access point and a controller, the system comprising:

means for transmitting from each of a subset of the plural access terminals a request to transmit in an interval, the request comprising an opportunity level indicating a reverse link channel condition;

means for making a decision at the access network to schedule at least one of the subset of the plural access terminals to transmit in the interval in accordance with the request; and

means for transmitting from the at least one access point the decision to the plural access terminals.

84. A system for scheduling at an access network comprising at least one access point and a controller user data transmission over a reverse link, the method comprising:

means for receiving at the access network at least one request to transmit in an interval, the request comprising an opportunity level indicating a reverse link channel condition;

means for making a decision at the access network to schedule at least one transmission in the interval in accordance with the at least one request; and

means for transmitting from the at least one access point the decision.