MESSAGE EXCHANGE SCHEME FOR ASYNCHRONOUS WIRELESS COMMUNICATION

• US 20080031224A1
• Filed: 08/03/2007
• Published: 02/07/2008
• Est. Priority Date: 08/07/2006
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Sampath, Ashwin, Nanda, Sanjiv
• Granted Patent: US 8,416,762 B2
• Time in Patent Office: Days
• US Class Current: 370/350
• CPC Class Codes: H04W 72/27 between access points
• CPC Class Codes: H04W 72/54 based on quality criteria

Abstract

A message exchange scheme for wireless communication employs a request, a grant, and a confirmation. In some implementations wireless media access control supports asynchronous communication and overlapping transmissions. Here, a wireless node may determine whether to request or schedule a transmission based on control messages it receives from neighboring nodes. In some implementations a scheduled transmission may be divided up into several segments so that a transmitting node may receive and transmit control messages between segments. In some implementations a monitoring period is defined after a scheduled transmission period to enable the transmitting node to acquire control information that may otherwise have been transmitted during the scheduled transmission period. In some implementations data and control information are transmitted over different frequency division multiplexed channels to enable concurrent transmission of the data and control information.

Claims

1. A method of wireless communication, comprising:

transmitting, by a first wireless node, a request to transmit data;

receiving a grant that schedules the requested data transmission; and

transmitting, in response to the grant, a confirmation that comprises information regarding the scheduled data transmission.

2. The method of claim 1, further comprising:

determining whether to transmit the request based on a determination of whether the transmission of data would interfere with reception at a second wireless node during a scheduled transmit time period.

3. The method of claim 1, further comprising:

issuing the request to transmit data based on whether the transmission of data would interfere with reception at a second wireless node.

4. The method of claim 3, further comprising:

receiving information indicative of scheduled reception of data at the second wireless node; and

defining a transmit constraints state based on the received information;

wherein the request to transmit data is issued based on the transmit constraints state.

5. The method of claim 4, wherein the transmit constraints state comprises at least one of the group consisting of:

transmission start time, transmission end time, transmission time period, receive margin, and a received signal strength indication associated with a grant or an acknowledgement.

6. The method of claim 4, wherein the transmit constraints state is used to determine whether to abstain from sending a request to transmit, delay sending of a request to transmit, adjust a transmit time period, or request to transmit at a reduced power level.

7. The method of claim 4, wherein:

the received information comprises a grant generated by the second wireless node in response to another request to transmit; and

the grant comprises at least one of the group consisting of;

transmission start time, transmission end time, transmission time period, transmission power, a quantity of redundancy bits to transmit, code rate, expected channel to interference ratio, receive margin, and a pilot signal.

8. The method of claim 4, wherein:

the received information comprises an acknowledgement generated by the second wireless node to acknowledge receipt of transmitted data; and

the acknowledgement comprises at least one of the group consisting of;

transmission start time, transmission end time, transmission time period, transmission power, a quantity of redundancy bits to transmit, code rate, expected channel to interference ratio, receive margin, and a pilot signal.

9. The method of claim 1, further comprising:

receiving a resource utilization message that comprises at least one of the group consisting of;

a level of desired interference reduction, a resource to be cleared, and an indication of a degree to which reception at a receiving wireless node is not meeting a desired level of quality of service; and

determining, based on the resource utilization message, whether to limit the request to transmit data.

10. The method of claim 9, wherein the determination of whether to limit the request to transmit data comprises at least one of the group consisting of:

abstaining from sending a request to transmit, requesting to transmit at a later time, delaying a request to transmit, determining a transmit time period, and requesting to transmit at a reduced power level.

11. The method of claim 9, further comprising performing, in response to the received resource utilization message, at least one of the group consisting of:

changing a rate at which requests are transmitted, abstaining from transmitting requests until a resource utilization message of an associated receiver indicates a higher degree of disadvantage than the received resource utilization message, changing a length of a scheduled transmit time period, changing a transmit power delta, and modifying a set of rules relating to a degree to which transmissions may interfere with reception by a second wireless node.

12. The method of claim 1, further comprising:

defining at least one transmission parameter based on the grant.

13. The method of claim 12, wherein the grant comprises at least one of the group consisting of:

transmission start time, transmission end time, transmission time period, transmission power, a quantity of redundancy bits to transmit, code rate, expected channel to interference ratio, receive margin, and a pilot signal.

14. The method of claim 1, wherein the scheduling of the requested data transmission is based on a determination of whether a second wireless node will be able to receive the data to be transmitted in a sustainable manner, taking into consideration potential transmissions by other wireless nodes.

15. The method of claim 1, wherein the confirmation comprises at least one of the group consisting of:

transmission start time, transmission end time, transmission time period, transmit power delta, packet format, and a pilot signal.

16. The method of claim 1, wherein:

in conjunction with the scheduled data transmission, data is transmitted during a plurality of time segments defined within a scheduled transmit time period; and

at least one time interval for transmission or reception of control information is temporally located between the time segments.

17. The method of claim 16, wherein:

the control information comprises at least one acknowledgement that acknowledges receipt of the data transmitted during the time segments; and

the at least one acknowledgement comprises at least one of the group consisting of;

transmission start time for at least one of the time segments, transmission end time for at least one of the time segments, transmission time period for at least one of the time segments, transmission power for at least one of the time segments, a quantity of redundancy bits to transmit for at least one of the time segments, code rate for at least one of the time segments, expected channel to interference ratio for at least one of the time segments, receive margin, and a pilot signal.

18. The method of claim 16, wherein:

the control information comprises at least one confirmation transmitted during the at least one time interval; and

the at least one confirmation comprises at least one of the group consisting of;

transmission start time for at least one of the time segments, transmission end time for at least one of the time segments, transmission time period for at least one of the time segments, transmit power delta, packet format, and a pilot signal.

19. The method of claim 1, wherein:

the request and the confirmation are transmitted and the grant is received via a control channel;

the data is transmitted via a data channel;

the control and data channels are frequency division multiplexed within a common frequency band; and

the control channel is associated with a plurality of sub-frequency bands that are interspersed within the common frequency band.

20. An apparatus for wireless communication, comprising:

a transmitter configured to transmit, at a first wireless node, a request to transmit data; and

a receiver configured to receive a grant that schedules the requested data transmission;

wherein the transmitter is further configured to transmit, in response to the grant, a confirmation that comprises information regarding the scheduled data transmission.

21. The apparatus of claim 20, further comprising:

a transmission controller configured to determine whether to transmit the request based on a determination of whether the transmission of data would interfere with reception at a second wireless node during a scheduled transmit time period.

22. The apparatus of claim 20, further comprising:

a transmission controller configured to issue the request to transmit data based on whether the transmission of data would interfere with reception at a second wireless node.

23. The apparatus of claim 22, wherein:

the receiver is further configured to receive information indicative of scheduled reception of data at the second wireless node;

the apparatus further comprises a state controller configured to define a transmit constraints state based on the received information; and

the request to transmit data is issued based on the transmit constraints state.

24. The apparatus of claim 23, wherein the transmit constraints state comprises at least one of the group consisting of:

transmission start time, transmission end time, transmission time period, receive margin, and a received signal strength indication associated with a grant or an acknowledgement.

25. The apparatus of claim 23, wherein the transmit constraints state is used to determine whether to abstain from sending a request to transmit, delay sending of a request to transmit, adjust a transmit time period, or request to transmit at a reduced power level.

26. The apparatus of claim 23, wherein:

the received information comprises a grant generated by the second wireless node in response to another request to transmit; and

the grant comprises at least one of the group consisting of;

transmission start time, transmission end time, transmission time period, transmission power, a quantity of redundancy bits to transmit, code rate, expected channel to interference ratio, receive margin, and a pilot signal.

27. The apparatus of claim 23, wherein:

the received information comprises an acknowledgement generated by the second wireless node to acknowledge receipt of transmitted data; and

the acknowledgement comprises at least one of the group consisting of;

transmission start time, transmission end time, transmission time period, transmission power, a quantity of redundancy bits to transmit, code rate, expected channel to interference ratio, receive margin, and a pilot signal.

28. The apparatus of claim 20, wherein:

the receiver is further configured to receive a resource utilization message that comprises at least one of the group consisting of;

a level of desired interference reduction, a resource to be cleared, and an indication of a degree to which reception at a receiving wireless node is not meeting a desired level of quality of service; and

the apparatus further comprises a transmission controller configured to determine, based on the resource utilization message, whether to limit the request to transmit data.

29. The apparatus of claim 28, wherein the determination of whether to limit the request to transmit data comprises at least one of the group consisting of:

abstaining from sending a request to transmit, requesting to transmit at a later time, delaying a request to transmit, determining a transmit time period, and requesting to transmit at a reduced power level.

30. The apparatus of claim 28, wherein the transmission controller is further configured to perform, in response to the received resource utilization message, at least one of the group consisting of:

changing a rate at which requests are transmitted, abstaining from transmitting requests until a resource utilization message of an associated receiver indicates a higher degree of disadvantage than the received resource utilization message, changing a length of a scheduled transmit time period, changing a transmit power delta, and modifying a set of rules relating to a degree to which transmissions may interfere with reception by a second wireless node.

31. The apparatus of claim 20, further comprising:

a transmission parameter defined configured to define at least one transmission parameter based on the grant.

32. The apparatus of claim 31, wherein the grant comprises at least one of the group consisting of:

transmission start time, transmission end time, transmission time period, transmission power, a quantity of redundancy bits to transmit, code rate, expected channel to interference ratio, receive margin, and a pilot signal.

33. The apparatus of claim 20, wherein the scheduling of the requested data transmission is based on a determination of whether a second wireless node will be able to receive the data to be transmitted in a sustainable manner, taking into consideration potential transmissions by other wireless nodes.

34. The apparatus of claim 20, wherein the confirmation comprises at least one of the group consisting of:

transmission start time, transmission end time, transmission time period, transmit power delta, packet format, and a pilot signal.

35. The apparatus of claim 20, wherein:

in conjunction with the scheduled data transmission, data is transmitted during a plurality of time segments defined within a scheduled transmit time period; and

at least one time interval for transmission or reception of control information is temporally located between the time segments.

36. The apparatus of claim 35, wherein:

the control information comprises at least one acknowledgement that acknowledges receipt of the data transmitted during the time segments; and

the at least one acknowledgement comprises at least one of the group consisting of;

transmission start time for at least one of the time segments, transmission end time for at least one of the time segments, transmission time period for at least one of the time segments, transmission power for at least one of the time segments, a quantity of redundancy bits to transmit for at least one of the time segments, code rate for at least one of the time segments, expected channel to interference ratio for at least one of the time segments, receive margin, and a pilot signal.

37. The apparatus of claim 35, wherein:

the control information comprises at least one confirmation transmitted during the at least one time interval; and

the at least one confirmation comprises at least one of the group consisting of;

transmission start time for at least one of the time segments, transmission end time for at least one of the time segments, transmission time period for at least one of the time segments, transmit power delta, packet format, and a pilot signal.

38. The apparatus of claim 20, wherein:

the request and the confirmation are transmitted and the grant is received via a control channel;

the data is transmitted via a data channel;

the control and data channels are frequency division multiplexed within a common frequency band; and

the control channel is associated with a plurality of sub-frequency bands that are interspersed within the common frequency band.

39. An apparatus for wireless communication, comprising:

means for transmitting, by a first wireless node, a request to transmit data;

means for receiving a grant that schedules the requested data transmission; and

means for transmitting, in response to the grant, a confirmation that comprises information regarding the scheduled data transmission.

40. The apparatus of claim 39, further comprising:

means for determining whether to transmit the request based on a determination of whether the transmission of data would interfere with reception at a second wireless node during a scheduled transmit time period.

41. The apparatus of claim 39, further comprising:

means for issuing the request to transmit data based on whether the transmission of data would interfere with reception at a second wireless node.

42. The apparatus of claim 41, wherein:

the means for receiving further receives information indicative of scheduled reception of data at the second wireless node;

the apparatus further comprises means for defining a transmit constraints state based on the received information; and

the request to transmit data is issued based on the transmit constraints state.

43. The apparatus of claim 42, wherein the transmit constraints state comprises at least one of the group consisting of:

transmission start time, transmission end time, transmission time period, receive margin, and a received signal strength indication associated with a grant or an acknowledgement.

44. The apparatus of claim 42, wherein the transmit constraints state is used to determine whether to abstain from sending a request to transmit, delay sending of a request to transmit, adjust a transmit time period, or request to transmit at a reduced power level.

45. The apparatus of claim 42, wherein:

the received information comprises a grant generated by the second wireless node in response to another request to transmit; and

the grant comprises at least one of the group consisting of;

transmission start time, transmission end time, transmission time period, transmission power, a quantity of redundancy bits to transmit, code rate, expected channel to interference ratio, receive margin, and a pilot signal.

46. The apparatus of claim 42, wherein:

the received information comprises an acknowledgement generated by the second wireless node to acknowledge receipt of transmitted data; and

the acknowledgement comprises at least one of the group consisting of;

transmission start time, transmission end time, transmission time period, transmission power, a quantity of redundancy bits to transmit, code rate, expected channel to interference ratio, receive margin, and a pilot signal.

47. The apparatus of claim 39, wherein:

the means for receiving further receives a resource utilization message that comprises at least one of the group consisting of;

a level of desired interference reduction, a resource to be cleared, and an indication of a degree to which reception at a receiving wireless node is not meeting a desired level of quality of service; and

the apparatus further comprises means for determining, based on the resource utilization message, whether to limit the request to transmit data.

48. The apparatus of claim 47, wherein the determination of whether to limit the request to transmit data comprises at least one of the group consisting of:

abstaining from sending a request to transmit, requesting to transmit at a later time, delaying a request to transmit, determining a transmit time period, and requesting to transmit at a reduced power level.

49. The apparatus of claim 47, wherein the means for determining further performs, in response to the received resource utilization message, at least one of the group consisting of:

changing a rate at which requests are transmitted, abstaining from transmitting requests until a resource utilization message of an associated receiver indicates a higher degree of disadvantage than the received resource utilization message, changing a length of a scheduled transmit time period, changing a transmit power delta, and modifying a set of rules relating to a degree to which transmissions may interfere with reception by a second wireless node.

50. The apparatus of claim 39, further comprising:

means for defining at least one transmission parameter based on the grant.

51. The apparatus of claim 50, wherein the grant comprises at least one of the group consisting of:

transmission start time, transmission end time, transmission time period, transmission power, a quantity of redundancy bits to transmit, code rate, expected channel to interference ratio, receive margin, and a pilot signal.

52. The apparatus of claim 39, wherein the scheduling of the requested data transmission is based on a determination of whether a second wireless node will be able to receive the data to be transmitted in a sustainable manner, taking into consideration potential transmissions by other wireless nodes.

53. The apparatus of claim 39, wherein the confirmation comprises at least one of the group consisting of:

transmission start time, transmission end time, transmission time period, transmit power delta, packet format, and a pilot signal.

54. The apparatus of claim 39, wherein:

in conjunction with the scheduled data transmission, data is transmitted during a plurality of time segments defined within a scheduled transmit time period; and

at least one time interval for transmission or reception of control information is temporally located between the time segments.

55. The apparatus of claim 54, wherein:

the control information comprises at least one acknowledgement that acknowledges receipt of the data transmitted during the time segments; and

the at least one acknowledgement comprises at least one of the group consisting of;

transmission start time for at least one of the time segments, transmission end time for at least one of the time segments, transmission time period for at least one of the time segments, transmission power for at least one of the time segments, a quantity of redundancy bits to transmit for at least one of the time segments, code rate for at least one of the time segments, expected channel to interference ratio for at least one of the time segments, receive margin, and a pilot signal.

56. The apparatus of claim 54, wherein:

the control information comprises at least one confirmation transmitted during the at least one time interval; and

the at least one confirmation comprises at least one of the group consisting of;

transmission start time for at least one of the time segments, transmission end time for at least one of the time segments, transmission time period for at least one of the time segments, transmit power delta, packet format, and a pilot signal.

57. The apparatus of claim 39, wherein:

the request and the confirmation are transmitted and the grant is received via a control channel;

the data is transmitted via a data channel;

the control and data channels are frequency division multiplexed within a common frequency band; and

the control channel is associated with a plurality of sub-frequency bands that are interspersed within the common frequency band.

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

computer-readable medium comprising codes executable by at least one computer to;

transmit, at a first wireless node, a request to transmit data; and

receive a grant that schedules the requested data transmission;

transmit, in response to the grant, a confirmation that comprises information regarding the scheduled data transmission.

59. An access point for wireless communication, comprising:

an antenna;

a transmitter configured to transmit via the antenna, at a first wireless node, a request to transmit data; and

a receiver configured to receive a grant that schedules the requested data transmission;

wherein the transmitter is further configured to transmit, in response to the grant, a confirmation that comprises information regarding the scheduled data transmission.

60. An access terminal for wireless communication, comprising:

a transmitter configured to transmit, at a first wireless node, a request to transmit data; and

a receiver configured to receive a grant that schedules the requested data transmission; and

a user interface configured to output an indication based on data received by the receiver;

wherein the transmitter is further configured to transmit, in response to the grant, a confirmation that comprises information regarding the scheduled data transmission.