METHOD AND SYSTEM FOR ADAPTIVELY OBTAINING BANDWIDTH ALLOCATION REQUESTS

• US 20080232342A1
• Filed: 05/13/2008
• Published: 09/25/2008
• Est. Priority Date: 12/22/2000
• 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.
• Granted Patent: US 8,249,051 B2
• Time in Patent Office: Days
• US Class Current: 370/346
• 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, the method comprising:

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

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

c) updating said UL map to accommodate said requested amount of UL bandwidth if there is sufficient UL bandwidth available for accommodating said requested amount of UL bandwidth.

2. A 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. A method as claimed in claim 1, wherein said bandwidth request uses a specified amount of UL bandwidth within the bandwidth allocated by said base station to said remote unit for UL traffic.

4. A method as claimed in claim 1, wherein said requested amount of UL bandwidth is allocated from said base station to said remote unit in a number of physical slots of a UL subframe.

5. A 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.

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

7. A method as claimed in claim 5, wherein said polling action is performed individually on inactive remote units.

8. A method as claimed in claim 5, wherein said polling action is not performed on active remote units which do not request explicitly to be polled.

9. A method as claimed in claim 5, wherein an active remote unit responds to said polling action with said bandwidth request, using a modulation scheme currently used by said remote unit.

10. A method as claimed in claim 5, 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.

11. A method as claimed in claim 10, wherein said poling rate changes as the traffic parameters change.

12. A method as claimed in claim 10, 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.

13. A method as claimed in claim 10, wherein the traffic parameters further include parameters associated with the wireless communication system.

14. A method as claimed in claim 13, 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.

15. A method as claimed in claim 10, 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.

16. A method as claimed in claim 10, 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.

17. A method as claimed in claim 10, 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.

18. A method as claimed in claim 10, 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.

19. A method as claimed in claim 5, 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.

20. A method as claimed in claim 10, wherein the polling rate is expressed as a time lapsed between two successive polling actions.

21. A method as claimed in claim 5, wherein said base station initiates said polling action upon identification of an explicit poll-me message received from said remote unit.

22. A method as claimed in claim 5, 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.

23. A 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.

24. A 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.

25. A method as claimed in claim 21, wherein said poll-me message is a priority poll-me message.

26. A method as claimed in claim 21, wherein said poll-me message is a poll-me bit.

27. A method as claimed in claim 26, 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.

28. A method as claimed in claim 21, wherein said poll-me message is a particular combination of bits.

29. A method as claimed in claim 28, wherein said combination of bits is provided in a reserved field of a packet received by said base station from said remote unit.

30. A method as claimed in claim 21, wherein said poll-me message specifies said requested amount of UL bandwidth in bandwidth units.

31. A method as claimed in claim 30, wherein said poll-me message further identifies an additional bandwidth request message provided within said UL traffic.

32. A method as claimed in claim 21, wherein the bits of said poll-me message are used to accommodate a control message other than a bandwidth request.

33. A method as claimed in claim 21, 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.

34. A method as claimed in claim 1, wherein said base station informs implicitly said remote unit that said request has been granted by including said requested amount of UL bandwidth in the UL map.

35. 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, the method comprising:

maintaining a DL map and a UL map with a current DL bandwidth allocations and UL bandwidth allocations and periodically broadcasting 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 accommodating said request amount of UL bandwidth; and

updating said UL map to accommodate said requested amount of UL bandwidth if there is sufficient UL bandwidth available for accommodating said requested amount of UL bandwidth.

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

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

polling inactive remote units;

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

updating said UL map to accommodate said requested amount of UL bandwidth if there is sufficient UL bandwidth available for accommodating said requested amount of UL bandwidth.