Method and apparatus for bandwidth request/grant protocols in a wireless communication system

• US 7,529,193 B2
• Filed: 11/01/2004
• Issued: 05/05/2009
• Est. Priority Date: 05/21/1999
• Status: Expired due to Term

• Current Assignee: Quarterhill Inc. (f/k/a Wi-LAN Inc.)
• Original Assignee: Quarterhill Inc. (f/k/a Wi-LAN Inc.)
• Inventors: Bourlas, Yair, Stanwood, Kenneth L., Zimmerman, Ofer
• Primary Examiner(s): MARCELO, MELVIN C
• Application Number:
  US10/978,903
• Publication Number:
  US 20050089064A1
• Time in Patent Office: 1,646 Days
• Field of Search: 370/252, 370/468
• US Class Current: 370/252
• CPC Class Codes: H04L 2012/5607 Radio
• CPC Class Codes: H04L 2012/561 Star, e.g. cross-connect, concentrator, subscriber group equipment, remote electronics
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections
• CPC Class Codes: H04W 28/14 using intermediate storage
• CPC Class Codes: H04W 28/20 Negotiating bandwidth
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/543 based on requested quality, e.g. QoS

Abstract

A method and apparatus for allocating bandwidth in a broadband wireless communication system is disclosed. One embodiment uses a self-correcting bandwidth request/grant protocol. The self-correcting bandwidth request/grant protocol utilizes a combination of incremental and aggregate bandwidth requests. CPEs primarily transmit incremental bandwidth requests to their associated base stations, followed by periodic transmissions of aggregate bandwidth requests. The use of periodic aggregate bandwidth requests (that express the current state of their respective connection queues) allows the bandwidth allocation method and apparatus to be “self-correcting”. Another embodiment utilizes an abridged bandwidth request/grant protocol to allocate bandwidth. The abridged bandwidth request/grant protocol system utilizes padding packets to request a reduction in bandwidth allocation to a CPE. A base station modem alerts a base station CPU when the BS modem receives a padding packet from a CPE. After alerting the BS CPU the method can reduce the associated CPE'"'"'s bandwidth allocation.

Claims

1. A method for allocating bandwidth in a broadband wireless communication system, wherein the wireless communication system includes a plurality of Customer Premise Equipment in communication with associated base stations, and wherein the base stations maintain uplink and downlink sub-frame maps representative of the bandwidth allocations in the uplink and downlink communication paths, the method comprising:

(a) determining an incremental bandwidth requirement for a selected Customer Premises Equipment;

(b) transmitting an incremental bandwidth request to a base station that is associated with the selected Customer Premises Equipment, wherein the incremental bandwidth request contains information indicative of the incremental bandwidth requirement determined in step (a);

(c) determining an aggregate bandwidth requirement for the selected Customer Premises Equipment;

(d) determining whether an aggregate bandwidth request should be transmitted to the base station associated with the selected Customer Premises Equipment such that an aggregate bandwidth request is sent periodically, wherein the aggregate bandwidth request contains information indicative of the aggregate bandwidth requirement determined in step (c);

(e) if the aggregate bandwidth request is determined to be required in step (d), transmitting the aggregate bandwidth request to the associated base station and returning to step (a), else returning to step (a) without transmitting the aggregate bandwidth request;

(f) obtaining a packet from an associated Customer Premises Equipment;

(g) determining whether the packet of step (f) is a padding packet;

(h) if the packet is a padding packet, alerting a base station CPU of the padding packet, else returning to step (f);

(i) reducing a bandwidth allocation of the associated Customer Premises Equipment; and

(j) returning to step (f).

2. The method for allocating bandwidth as defined in claim 1, wherein the incremental bandwidth requirement comprises the change in bandwidth requirements since the selected Customer Premises Equipment last requested bandwidth from the associated base station.

3. The method for allocating bandwidth as defined in claim 1, wherein the aggregate bandwidth requirement determined in step (c) comprises a total immediate bandwidth requirement for the selected Customer Premises Equipment.

4. The method for allocating bandwidth as defined in claim 1, wherein the step (d) of determining whether an aggregate bandwidth request should be transmitted to the associated base station comprises:

(a) counting consecutive transmissions of incremental bandwidth requests;

(b) comparing the number of consecutive transmissions counted in step (a) to a pre-determined incremental bandwidth request threshold value; and

(c) indicating that an aggregate bandwidth request is required if the number of consecutive transmissions of incremental bandwidth requests equals the pre-determined threshold, else returning to step (a).

5. The method for allocating bandwidth as defined in claim 1, wherein the step (d) of determining whether an aggregate bandwidth request should be transmitted to the associated base station comprises:

(a) waiting a pre-determined time interval between transmissions of aggregate bandwidth requests;

(b) indicating that an aggregate bandwidth request is required when the pre-determined time interval has expired, else returning to step (a).

6. The method for allocating bandwidth as defined in claim 1, wherein step (e) further comprises resetting records representative of the total bandwidth requirements of the selected Customer Premises Equipment, at the associated base station in response to the transmitted aggregate bandwidth request.

7. The method for allocating bandwidth as defined in claim 1, wherein the incremental and aggregate bandwidth requests are transmitted by the selected Customer Premises Equipment to the associated base station using a piggybacking technique, wherein the selected Customer Premises Equipment transmits the bandwidth requests using unused bandwidth in packets of existing bandwidth allocations.

8. The method for allocating bandwidth as defined in claim 1, wherein the incremental and aggregate bandwidth requests are transmitted by the selected Customer Premises Equipment to the associated base station using an individual polling technique, wherein the selected Customer Premises Equipment is individually polled by the associated base station for its bandwidth requirements.

9. The method for allocating bandwidth as defined in claim 8, wherein the associated base station allocates bandwidth to the selected Customer Premises Equipment in an uplink sub-frame map, and wherein the base station determines whether the selected Customer Premises Equipment requests polling by setting a poll-me bit associated with the selected Customer Premises Equipment.

10. The method for allocating bandwidth as defined in claim 1, wherein bandwidth requests are transmitted to the associated base station using a bandwidth request message.

11. The method for allocating bandwidth as defined in claim 10, wherein the bandwidth request message includes a Message Type ID field, a Connection ID/Quality of Service field, a Request Type field, and an Amount Requested field.

12. The method for allocating bandwidth as defined in claim 11, wherein the Request Type field indicates whether an incremental or an aggregate bandwidth request is being transmitted.

13. The method for allocating bandwidth as defined in claim 11, wherein the Amount Requested field indicates the amount of bandwidth being requested by the selected Customer Premises Equipment.

14. The method for allocating bandwidth as defined in claim 13, wherein the amount of bandwidth being requested is expressed in bytes.

15. The method for allocating bandwidth as defined in claim 13, wherein the amount of bandwidth being requested is expressed in packets.

16. The method for allocating bandwidth as defined in claim 11, wherein the Message Type ID field comprises a pre-determined constant value indicating to the communication system that a bandwidth request message is being transmitted.

17. The method for allocating bandwidth as defined in claim 11, wherein the Connection ID/Quality of Service field indicates either an identifier for a connection between the selected Customer Premises Equipment and the associated base station, or a quality of service associated with the connection between the selected Customer Premises Equipment and the associated base station.

18. The method for allocating bandwidth as defined in claim 17, wherein the quality of service associated with the connection is assigned at a time when the connection is first established between the Customer Premises Equipment and the associated base station.

19. The method for allocating bandwidth of claim 1 wherein the step (h) of alerting a base station CPU comprises transmitting a flag packet to the base station CPU.

20. The method for allocating bandwidth of claim 19 wherein the flag packet comprises information regarding an associated CPU.

21. The method for allocating bandwidth of claim 1 wherein the step (h) of alerting a base station CPU uses a shared memory processor.

22. The method for allocating bandwidth of claim 1 wherein

the obtaining a packet step (f), the determining whether the packet step (g) and the alerting a base station CPU step (h) are performed by a base station modem and

the reducing a bandwidth allocation step (i) is performed by a base station CPU.

23. The method for allocating bandwidth of claim 1 wherein

the obtaining a packet step (f) is performed by a base station modem and

the determining whether the packet step (g), the if the packet is a padding packet, alerting a base station CPU step (h) and the reducing a bandwidth allocation step (i) are performed by a base station CPU.

24. The method for allocating bandwidth of claim 1 wherein the step (i) of reducing a bandwidth allocation comprises resetting all requested bandwidth for the associated Customer Premises Equipment.

25. A broadband wireless communication system, wherein the wireless communication system includes one or more of Customer Premise Equipment in communication with an associated base station, and wherein the base station maintains uplink and downlink sub-frame maps representative of the bandwidth allocations in the uplink and downlink communications paths, the system comprising:

(a) bandwidth requirement calculating means for calculating an incremental bandwidth requirement and an aggregate bandwidth requirement of a selected Customer Premises Equipment;

(b) transmitting means, operatively coupled to the bandwidth requirement calculating means, for transmitting an incremental bandwidth request and an aggregate bandwidth request to a base station associated with the selected Customer Premises Equipment, wherein the incremental bandwidth request is indicative of the incremental bandwidth requirement of the selected Customer Premises Equipment, and wherein the aggregate bandwidth request is indicative of the aggregate bandwidth requirement of the selected Customer Premises Equipment;

(c) determining means, operatively coupled to the transmitting means, for determining whether the aggregate bandwidth request should be transmitted to the associated base station, wherein the determining means causes the transmitting means to periodically transmit the aggregate bandwidth request;

(d) packet obtaining means for obtaining a packet from an associated Customer Premises Equipment;

(e) packet determining means, coupled to the packet obtaining means, for determining whether a packet is a padding packet;

(f) base station CPU alerting means, coupled to the packet determining means, for alerting a base station CPU of a padding packet; and

(g) bandwidth allocation reducing means, coupled to the base station CPU alerting means, for reducing a bandwidth allocation of the associated Customer Premises Equipment.

26. The system as defined in claim 25, wherein the incremental bandwidth requirement comprises the change in bandwidth requirements since the selected Customer Premises Equipment last requested bandwidth from the associated base station.

27. The system as defined in claim 25, wherein the aggregate bandwidth requirement comprises a total immediate bandwidth requirement for the selected Customer Premises Equipment.

28. The system as defined in claim 25, wherein the means for determining whether an aggregate bandwidth request should be transmitted to the associated base station comprises:

(a) means for counting consecutive transmissions of incremental bandwidth requests;

(b) means for comparing the number of consecutive transmissions counted by the counting means with a pre-determined incremental bandwidth request threshold value; and

(c) means for indicating that an aggregate bandwidth request is required whenever the number of consecutive transmissions of incremental bandwidth requests equals the pre-determined threshold.

29. The system as defined in claim 28, wherein the means for counting consecutive transmissions of incremental bandwidth requests includes a dynamic timer.

30. The system as defined in claim 29, wherein the timer is set to a pre-determined number of frames that the apparatus waits between transmissions of aggregate bandwidth requests, and wherein the time in decremented each time that an incremental bandwidth request is transmitted.

31. The system as defined in claim 30, wherein the pre-determined number of frames that the apparatus waits between transmissions of aggregate bandwidth requests depends upon a quality of service associated with a connection between the Customer Premises Equipment and the associated base station.

32. The system as defined in claim 25, wherein a base station modem comprises the packet obtaining means, the packet determining means and the base station CPU alerting means and wherein a base station CPU comprises the bandwidth allocation reducing means.

33. The system as defined in claim 25, wherein a base station modem comprises the packet obtaining means and wherein a base station CPU comprises the packet determining means, the base station CPU alerting means and the bandwidth allocation reducing means.