METHOD AND SYSTEM FOR ADAPTIVELY OBTAINING BANDWIDTH ALLOCATION REQUESTS

• US 20080232391A1
• 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 8,243,663 B2
• Time in Patent Office: Days
• US Class Current: 370/449
• 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 base station for a broadband wireless communication system, comprising:

A transceiver 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 said requested amount of bandwidth is available, and allocating to said remote unit said requested amount of UL bandwidth, if available,

wherein said base station implicitly informs said remote unit that said request has been granted by including said requested amount of UL bandwidth in an UL bandwidth amount granted to said remote unit.

2. A base station as claimed in claim 1, wherein said bandwidth allocation module comprises:

a media access arbiter for receiving said request and granting said requested amount of bandwidth, if available; and

a processor adapted to maintain an UL map with uplink bandwidth allocations, dynamically update said UL map to account for said requested amount of UL bandwidth, if granted, and provide updated UL map to said transceiver for broadcasting to all remote units.

3. A base station as claimed in claim 1, wherein said requested 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.

4. A base station as claimed in claim 1, wherein said bandwidth allocation module always grants said requested amount of UL bandwidth when said bandwidth request specifies a continuous grant service connection type.

5. A base station as claimed in claim 1, 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.

6. A base station as claimed in claim 5, wherein said traffic parameters include a QoS granted to said specified connection.

7. A base station as claimed in claim 5, wherein said traffic parameters include a modulation scheme used for the data transmitted on said connection.

8. A base station as claimed in claim 5, 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.

9. A base station as claimed in claim 1, wherein said base station further comprises 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.

10. A base station as claimed in claim 9, wherein said polling action is performed individually on inactive remote units.

11. A base station as claimed in claim 1, 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.

12. A base station as claimed in claim 9, wherein said polling action is initiated for a group of active remote units that have not requested explicitly to be polled.

13. A base station as claimed in claim 9, 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.

14. A base station as claimed in claim 9, further comprising a polling policy module that establishes a polling rate for said remote unit.

15. A base station as claimed in claim 14, wherein said polling rate is estimated by said polling policy module based on a plurality of BW allocation parameters, whereby said poling rate changes as the BW allocation parameters change.

16. A base station as claimed in claim 15, wherein the BW allocation parameters include one or more of:

the QoS required by a user connection established with said specified remote unit, the rate of recent bandwidth usage associated with said specified remote unit, and a traffic priority contractually negotiated for the remote unit.

17. A base station as claimed in claim 16, wherein the BW allocation parameters further include system parameters.

18. A base station as claimed in claim 17, wherein the system parameters include one or more of the amount of bandwidth available for sharing, 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.

19. A base station as claimed in claim 14, wherein said poling rate changes dynamically assuming a finite number of categorical values, each categorical value corresponding to a set of values assumed by said BW allocation parameters.

20. A base station as claimed in claim 1, wherein said bandwidth request processing module identifies said BW request within the UL bandwidth allocated to said remote unit for data traffic.

21. A base station as claimed in claim 20, wherein said bandwidth request processing module identifies said BW request based on the structure of said BW request.

22. A base station as claimed in claim 9, wherein said polling action is initiated by said base station upon identification of an explicit poll-me message received from said remote unit.

23. A base station as claimed in claim 22, wherein said poll-me message is a priority poll-me message.

24. A base station as claimed in claim 22, wherein said poll-me message is a poll-me bit.

25. A base station as claimed in claim 24, 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.

26. A base station as claimed in claim 22, wherein said poll-me message is a particular combination of bits.

27. A base station as claimed in claim 26, wherein said poll-me message is provided in a reserved field of a packet sent by said remote unit to said base station.

28. A base station as claimed in claim 22, wherein said poll-me message specifies said required amount of bandwidth in bandwidth units.

29. A base station as claimed in claim 11, 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.

30. A method as claimed in claim 22, wherein said poll-me message further specifies an additional bandwidth request message within said UL traffic.

31. A method as claimed in claim 22, 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.

32. A base station as claimed in claim 1, 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;

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

33. A base station as claimed in claim 32 wherein said HL-MAA uses a traffic shaping algorithm for placing data in each said queue.

34. A base station as claimed in claim 32 wherein said LL-MAA uses a queue-specific fairness algorithm for distributing data between the queues of said set of queues.

35. A base station as claimed in claim 32, wherein said LL-MAA process uses one of a fair weighted queueing method and a round robin queueing method.

36. A base station as claimed in claim 34, 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.

37. 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:

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 said requested amount of bandwidth is available, and allocating to said remote unit said requested amount of UL bandwidth, if available and comprising

a media access arbiter for receiving said request and granting said requested amount of bandwidth, if available, and

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