METHOD AND SYSTEM FOR ADAPTIVELY OBTAINING BANDWIDTH ALLOCATION REQUESTS

• US 20120026873A1
• Filed: 10/11/2011
• Published: 02/02/2012
• Est. Priority Date: 05/21/1999
• Status: Active Grant

• Current Assignee: Quarterhill Inc. (f/k/a Wi-LAN Inc.)
• Original Assignee: Quarterhill Inc. (f/k/a Wi-LAN Inc.)
• Inventors: Spinar, Brian, Stanwood, Kenneth L., Gilbert, Sheldon I., Klein, Israel Jay, Mollenauer, James F.
• Granted Patent: US 8,457,061 B2
• Time in Patent Office: Days
• US Class Current: 370/230
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 28/20 Negotiating bandwidth
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/06 using polling

Abstract

A method and apparatus for adaptively obtaining bandwidth requests in a broadband wireless communication system. The method and apparatus includes dynamically varying technique combinations enabling a plurality of users to efficiently request bandwidth from a shared base station. A user may “piggyback” a new bandwidth request upon, or set a “poll-me bit” within, presently allocated bandwidth. A base station may poll users, individually or in groups, by allocating unrequested bandwidth for new requests. Polling may respond to a “poll-me bit,” and/or it may be adaptively periodic at a rate based on communication status parameters, such as recent communication activity and connection QoS levels Group polling permits a possibility of collisions. Polling policies may be established for dynamically varying user groups, or may be determined for each user. Dynamic selection of appropriate polling techniques makes use of efficiency benefits associated with each technique.

Claims

1. A method for dynamically allocating UL bandwidth in a base station for a broadband wireless communication system where the base station exchanges uplink (UL) and downlink (DL) traffic with one or more remote units over a shared link, the method comprising:

maintaining at the base station a DL map and a UL map with a current DL bandwidth allocations and UL bandwidth allocations and periodically transmitting the maps to said remote units;

identifying within the UL traffic received from a remote unit, a bandwidth request specifying a requested amount of UL bandwidth;

based on said specified requested amount of UL bandwidth and on UL bandwidth available for sharing on said shared link, allocating an UL bandwidth grant to said remote unit; and

updating said UL map based upon said UL bandwidth grant.

2. The method as claimed in claim 1, wherein said bandwidth request is identified by said base station based on the structure of said bandwidth request.

3. The method as claimed in claim 1, wherein said UL bandwidth grant is allocated from said base station to said remote unit in a number of physical slots of a UL subframe.

4. The method as claimed in claim 1, wherein said bandwidth request is provided to said base station in response to a polling action initiated at said base station.

5. The method as claimed in claim 4, wherein an inactive remote unit responds to said polling action using a QAM-4 modulation scheme.

6. The method as claimed in claim 4, wherein said polling action is performed individually on inactive remote units.

7. The method as claimed in claim 4, wherein an active remote unit responds to said polling action with said bandwidth request, using a modulation scheme currently used by said remote unit.

8. The method as claimed in claim 4, wherein said remote unit is polled from said base station at a polling rate determined by said base station using one or more traffic parameters.

9. The method as claimed in claim 8, wherein said polling rate changes as the traffic parameters change.

10. The method as claimed in claim 9, wherein the traffic parameters include one or more of:

the QoS required by user connections established with said remote unit;

the rate of recent bandwidth usage associated with said remote unit, and a traffic priority contractually negotiated with the remote unit.

11. The method as claimed in claim 8, wherein the traffic parameters further include parameters associated with the wireless communication system.

12. The method as claimed in claim 11, wherein the parameters associated with the wireless communication system comprise one or more of:

the amount of bandwidth available for sharing among said remote units, the number of active remote units, the bandwidth currently used by the DL traffic, a composite priority parameter, and an estimated amount of bandwidth needed to accommodate bandwidth requests.

13. The method as claimed in claim 8, wherein said poling rate assumes a finite number of categorical values, each categorical value corresponding to a set of values assumed by said traffic parameters.

14. The method as claimed in claim 8, wherein the polling rate is determined as a continuous function of said traffic parameters if a large number of polling rates may be derived from the traffic parameters.

15. The method as claimed in claim 8, wherein said base station establishes a plurality of polling rates derived from the traffic parameters of remote units served by said base station, and uses an individual polling rate for each said remote unit.

16. The method as claimed in claim 8, wherein said base station establishes a plurality of polling rates derived from the traffic parameters of remote units served by said base station, and uses a polling rate for a group of remote units.

17. The method as claimed in claim 4, wherein said polling action is initiated periodically by said base station for polling said remote unit, a group of remote units, or all remote units that communicate with said base station.

18. The method as claimed in claim 8, wherein the polling rate is expressed as a time lapsed between two successive polling actions.

19. The method as claimed in claim 4, wherein said base station initiates said polling action upon identification of an explicit poll-me message received from said remote unit.

20. The method as claimed in claim 4, wherein said base station performs said polling action individually on active remote units which request to be polled explicitly, on receipt of a “

poll-me”

message within UL bandwidth already allocated to the respective remote unit.

21. The method as claimed in claim 1, wherein said bandwidth request is transmitted by said remote unit in unused UL bandwidth allocated to said remote unit.

22. The method as claimed in claim 1, wherein said bandwidth request is transmitted by said remote unit by stealing UL bandwidth allocated to said remote unit for data transmission.

23. The method as claimed in claim 19, wherein said poll-me message is a priority poll-me message.

24. The method as claimed in claim 19, wherein said poll-me message is inserted in a packet transmitted from said remote unit to said base station, which packet includes unused bytes, but does not have enough unused bytes to accommodate a bandwidth request.

25. The method as claimed in claim 1, wherein said base station informs implicitly said remote unit that said bandwidth request has been granted by including said UL bandwidth grant in the UL map.

26. A method for dynamically allocating UL bandwidth for a broadband wireless communication system where the base station exchanges uplink (UL) and downlink (DL) traffic with one or more remote units over a shared link, the method comprising:

maintaining a DL map and a UL map with a current DL bandwidth allocations and UL bandwidth allocations and periodically transmitting the maps to said remote units;

identifying within the UL traffic received from a remote unit, a bandwidth request specifying a requested amount of UL bandwidth;

determining whether there is sufficient UL bandwidth available for granting said requested amount of UL bandwidth; and

updating said UL map to indicate any granted amount of UL bandwidth.

27. A base station for a wireless communication system where the base station exchanges uplink (UL) and downlink (DL) traffic with one or more remote units over a shared link and dynamically allocates UL bandwidth, the base station comprising:

a transmitter system for transmitting DL traffic to remote units and a receiver for receiving UL traffic from said remote units;

a bandwidth request processing module for detecting a bandwidth (BW) request in the UL traffic received from a remote unit and identifying in said BW request a requested amount of UL bandwidth pertaining to a specified connection established at said remote unit; and

a bandwidth allocation module comprising

a media access arbiter for receiving said request, determining if bandwidth is available for said remote unit, and then allocating to said remote unit a granted amount of UL bandwidth, and

a processor for maintaining an UL map with uplink bandwidth allocations, updating said UL map to account for said granted amount of UL bandwidth, providing the updated UL map to said transmitter for transmitting to remote units, and indicating to said remote unit that said request has been granted by providing said granted amount of bandwidth to said remote unit.

28. The base station as claimed in claim 27, further comprising a polling module that executes a polling action individually on active remote units which request explicitly to be polled.

29. The base station as claimed in claim 27, wherein said granted amount of UL bandwidth is allocated from said base station to said remote unit based on a type of service established for said specified connection.

30. The base station as claimed in claim 27, wherein said bandwidth allocation module always grants said requested amount of UL bandwidth when said bandwidth request specifies a continuous grant service connection type.

31. The base station as claimed in claim 27, wherein for a connection type other than a continuous grant service type connection, said bandwidth allocation module grants said requested amount of UL bandwidth based on one or more traffic parameters characterizing said specified connection.

32. The base station as claimed in claim 31, wherein said traffic parameters include a quality of service (QoS) parameter characterizing said specified connection.

33. The base station as claimed in claim 31, wherein said traffic parameters include a modulation scheme used for the data transmitted on said connection.

34. The base station as claimed in claim 28, wherein the polling action is performed by the base station upon identification of an explicit poll-me message received from the remote unit.

35. The base station as claimed in claim 34, wherein said poll-me message is a poll-me bit.

36. A base station for a broadband wireless communication system, comprising:

a transmitter system for transmitting downlink (DL) traffic to remote units and a receiver for receiving uplink (UL) traffic from said remote units;

a bandwidth request processing module for detecting a bandwidth (BW) request in the UL traffic received from a remote unit and identifying in said BW request a requested amount of UL bandwidth pertaining to a specified connection established at said remote unit;

a bandwidth allocation module comprising

a media access arbiter for receiving said request, for determining if bandwidth is available for said remote unit, and then allocating to said remote unit a granted amount of UL bandwidth, and

a processor for maintaining an UL map with uplink bandwidth allocations, dynamically update said UL map to account for said granted amount of UL bandwidth, provide the updated UL map to said transmitter for transmitting to remote units and indicate to said remote unit that said request has been granted by providing said granted amount of bandwidth to said remote unit.

37. The base station as claimed in claim 36, wherein said granted amount of UL bandwidth is equal to said requested amount of UL bandwidth.

38. The base station as claimed in claim 36, wherein said granted amount of UL bandwidth is allocated from said base station to said remote unit based on a type of service established for said specified connection.

39. The base station as claimed in claim 36, wherein said bandwidth allocation module always grants said requested amount of UL bandwidth when said bandwidth request specifies a continuous grant service connection type.

40. The base station as claimed in claim 36, wherein said base station further comprises a polling module that initiates a polling action performed individually on active remote units which request explicitly to be polled.

41. The base station as claimed in claim 40, wherein said polling action is performed individually on an active remote units which explicitly requests to be polled by transmitting a poll-me message within UL bandwidth already allocated to the respective remote unit.

42. The base station as claimed in claim 36, wherein said bandwidth request processing module identifies said BW request within the UL bandwidth allocated to said remote unit for data traffic.

43. The base station as claimed in claim 42, wherein said bandwidth request processing module identifies said BW request based on the structure of said BW request.

44. A base station for a broadband wireless communication system, comprising:

a transmitter for transmitting downlink (DL) traffic to remote units and a receiver for receiving uplink (UL) traffic from said remote units;

a bandwidth request processing module for detecting a bandwidth (BW) request in the UL traffic received from a remote unit and identifying in said BW request a requested amount of UL bandwidth pertaining to a specified connection established at said remote unit; and

a bandwidth allocation module for determining if bandwidth is available for said remote unit, and if bandwidth is available for the remote unit then allocating to said remote unit a granted amount of UL bandwidth,

wherein said bandwidth allocation module indicates to said remote unit that said bandwidth request has been granted by providing said granted amount of UL bandwidth to said remote unit and for a connection type other than a continuous grant service type connection, said bandwidth allocation module grants said requested amount of UL bandwidth based on one or more traffic parameters characterizing said specified connection.

45. The base station as claimed in claim 44, wherein said traffic parameters include a quality of service (QoS) parameter characterizing said specified connection.

46. The base station as claimed in claim 44, wherein said traffic parameters include a modulation scheme used for the data transmitted on said connection.

47. The base station as claimed in claim 44, wherein said traffic parameters include a fairness criterion used by said base station to keep any individual remote unit from using up all available bandwidth.

48. The base station as claimed in claim 44, wherein said granted amount of UL bandwidth is equal to said requested amount of UL bandwidth.

49. A base station for a broadband wireless communication system, comprising:

a transmitter for transmitting downlink (DL) traffic to remote units and a receiver for receiving uplink (UL) traffic from said remote units;

a bandwidth request processing module for detecting a bandwidth (BW) request in the UL traffic received from a remote unit and identifying in said BW request a requested amount of UL bandwidth pertaining to a specified connection established at said remote unit;

a bandwidth allocation module for determining if bandwidth is available for the remote unit, and if bandwidth is available for the remote unit then allocating to said remote unit a granted amount of UL bandwidth,

wherein said bandwidth allocation module indicates to said remote unit that said bandwidth request has been granted by providing said granted amount of UL bandwidth to said remote unit; and

a polling module that initiates a polling action by allocating an unrequested amount of UL bandwidth to said remote unit for enabling said remote unit to transmit said bandwidth request to said base station.

50. The base station as claimed in claim 49, wherein said polling action is performed individually on inactive remote units.

51. The base station as claimed in claim 49, wherein said polling action is initiated for a group of active remote units that have not requested explicitly to be polled.

52. The base station as claimed in claim 49, wherein said remote unit is an active remote unit that responds to said polling action using a modulation scheme currently used by said remote unit for data transmission.

53. The base station as claimed in claim 49, wherein said polling action is initiated by said base station upon identification of an explicit poll-me message received from said remote unit.

54. The base station as claimed in claim 53, wherein said poll-me message is a priority poll-me message.

55. The base station as claimed in claim 53, wherein said poll-me message is a poll-me bit.

56. The base station as claimed in claim 55, wherein said poll-me bit is provided in a reserved field in the header of a packet sent by said remote unit to said base station.

57. The base station as claimed in claim 53, wherein said poll-me message is a particular combination of bits.

58. The base station as claimed in claim 57, wherein said poll-me message is provided in a reserved field of a packet sent by said remote unit to said base station.

59. The base station as claimed in claim 53, wherein said poll-me message specifies said required amount of bandwidth in bandwidth units.

60. The base station as claimed in claim 53, wherein said poll-me message further specifies an additional bandwidth request message within said UL traffic.

61. The base station as claimed in claim 53, wherein said poll-me message is inserted in a packet transmitted from said remote unit to said base station, which packet includes a number of unused bytes, insufficient for accommodating a bandwidth request.

62. The base station as claimed in claim 49 wherein said granted amount of UL bandwidth is equal to said requested amount of UL bandwidth.

63. A base station for a broadband wireless communication system, comprising:

a transmitter for transmitting downlink (DL) traffic to remote units and a receiver for receiving uplink (UL) traffic from said remote units;

a bandwidth request processing module for detecting a bandwidth (BW) request in the UL traffic received from a remote unit and identifying in said BW request a requested amount of UL bandwidth pertaining to a specified connection established at said remote unit;

a bandwidth allocation module for determining if bandwidth is available for the remote unit, and if bandwidth is available for the remote unit then allocating to said remote unit a granted amount of UL bandwidth;

wherein said bandwidth allocation module indicates to said remote unit said bandwidth request has been granted by providing said granted amount of UL bandwidth to said remote unit; and

wherein said bandwidth allocation module comprises a queue for each connection type supported by said base station, for accumulating data that is ready to be transmitted to the remote unit;

a high layer media access arbiter (HL-MAA) process for placing data in each said queue; and

a low level media access arbiter (LL-MAA) process for allocating an amount of downlink (DL) bandwidth to said remote unit and distributing data between the queues of said set of queues, based on a queue-specific fairness algorithm.

64. The base station as claimed in claim 63, wherein said HL-MAA uses a traffic shaping algorithm for placing data in each said queue.

65. The base station as claimed in claim 63, wherein said LL-MAA uses a queue-specific fairness algorithm for distributing data between the queues of said set of queues.

66. The base station as claimed in claim 63, wherein said LL-MAA process uses one of a fair weighted queueing method and a round robin queueing method.

67. The base station as claimed in claim 65, wherein said queue-specific fairness algorithm takes into account one or more of:

a QoS granted to each connection, a modulation scheme used for data transmission and a fairness criterion used by said base station to keep any individual remote unit from using up all available bandwidth.

68. A base station for a broadband wireless communication system which transmits downlink (DL) traffic to remote units and receives uplink (UL) traffic from said remote units, the base station comprising:

an antenna system for transmitting downlink (DL) traffic to remote units and receiving uplink (UL) traffic from said remote units;

a bandwidth request processing module for detecting a bandwidth (BW) request in the UL traffic received from a remote unit and identifying in said BW request a requested amount of UL bandwidth pertaining to a specified connection established at said remote unit; and

a bandwidth allocation module for determining if bandwidth is available for the remote unit, and allocating to said remote unit a granted amount of UL bandwidth, if bandwidth is available for the remote unit and comprising

a media access arbiter for receiving said request and granting said granted amount of bandwidth, if UL bandwidth is available for said remote unit, and

a processor for maintaining a DL map and an UL map with downlink and uplink bandwidth allocations respectively, dynamically update said UL map to account for said granted amount of UL bandwidth, if said granted amount of UL bandwidth is granted, and provide updated DL and UL maps to said antenna system for broadcasting to all remote units.

69. The base station as claimed in claim 68, wherein said granted amount of UL bandwidth is equal to said requested amount of UL bandwidth.