Methods and systems for transmission of multiple modulated signals over wireless networks

• US 8,027,298 B2
• Filed: 12/23/2009
• Issued: 09/27/2011
• Est. Priority Date: 05/21/1999
• Status: Expired due to Fees

• Current Assignee: Quarterhill Inc. (f/k/a Wi-LAN Inc.)
• Original Assignee: Quarterhill Inc. (f/k/a Wi-LAN Inc.)
• Inventors: Mollenauer, James F., Klein, Israel Jay, Stanwood, Kenneth L., Gilbert, Sheldon L.
• Primary Examiner(s): LY, ANH VU H
• Application Number:
  US12/645,947
• Publication Number:
  US 20100150094A1
• Time in Patent Office: 643 Days
• Field of Search: None
• US Class Current: 370/329
• 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: H04L 5/0064 Rate requirement of the data, e.g. scalable bandwidth, data priority
• CPC Class Codes: H04L 5/0092 Indication of how the channel is divided
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections
• CPC Class Codes: H04W 28/0268 using specific QoS parameters for wireless networks, e.g. QoS class identifier [QCI] or guaranteed bit rate [GBR] negotiating SLA or negotiating QoS H04W28/24
• 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 28/14 using intermediate storage
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 56/0005 synchronizing of arrival of multiple uplinks
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 72/044 based on the type of the allocated resource
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• 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 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 72/51 based on terminal or device properties
• CPC Class Codes: H04W 72/56 based on priority criteria
• CPC Class Codes: H04W 74/06 using polling
• CPC Class Codes: H04W 76/11 : Allocation or use of connection identifiers
• CPC Class Codes: H04W 8/24 : Transfer of terminal data

Abstract

A method and apparatus for requesting and allocating bandwidth in a broadband wireless communication system. The inventive method and apparatus includes a combination of techniques that allow a plurality of CPEs to communicate their bandwidth request messages to respective base stations. One technique includes a “polling” method whereby a base station polls CPEs individually or in groups and allocates bandwidth specifically for the purpose of allowing the CPEs to respond with bandwidth requests. The polling of the CPEs by the base station may be in response to a CPE setting a “poll-me bit” or, alternatively, it may be periodic. Another technique comprises “piggybacking” bandwidth requests on bandwidth already allocated to a CPE. In accordance with this technique, currently active CPEs request bandwidth using previously unused portions of uplink bandwidth that is already allocated to the CPE. The CPE is responsible for distributing the allocated uplink bandwidth in a manner that accommodates the services provided by the CPE. By using a combination of bandwidth allocation techniques, the present invention advantageously makes use of the efficiency benefits associated with each technique.

Claims

1. A base station for communication with a plurality of subscriber units connected in a wireless communication system, the base station comprising:

a transmitter for transmitting downlink (DL) traffic to subscriber units; and

one or more processors having a media access control (MAC) module configured to

detect a bandwidth request in uplink (UL) data received from a subscriber unit and identify in the bandwidth request a requested amount of UL bandwidth pertaining to a UL queue established at the subscriber unit;

determine if the requested amount of bandwidth is available; and

allocate to the subscriber unit an UL bandwidth grant based on the requested amount and the bandwidth available for UL data, wherein the UL bandwidth grant is allocated to the subscriber unit for distribution, without any control from the base station, between the connections established at the subscriber unit.

2. A base station as claimed in claim 1, wherein upon identification of an explicit message received from the subscriber unit, the base station responds by providing the subscriber unit with an allocation of UL bandwidth for enabling the subscriber unit to transmit the bandwidth request to the base station.

3. A base station as claimed in claim 1, wherein the bandwidth request is received in a contention bandwidth allocation provided to a group of subscriber units.

4. A base station as claimed in claim 1, wherein the bandwidth request is identified within UL bandwidth allocated to the subscriber unit for traffic.

5. A base station as claimed in claim 1, wherein the bandwidth request is identified within UL bandwidth specifically allocated to the subscriber units for respective bandwidth requests.

6. A base station as claimed in claim 1, wherein the bandwidth request is identified within UL bandwidth specifically allocated to a group of connections for bandwidth requests.

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

9. A base station as claimed in claim 1, wherein, for a connection of a type other than a continuous grant service type, the MAC module allocates the UL bandwidth grant to the subscriber unit based on one or more traffic parameters.

10. A base station as claimed in claim 9, wherein the traffic parameters include a fairness criterion used by the MAC module with a view to keep the subscriber unit from using up all available bandwidth.

11. A base station as claimed in claim 1, wherein the bandwidth grant is further determined based on one or more bandwidth (BW) allocation parameters.

7. A base station for communication with a plurality of subscriber units connected in a wireless communication system, the base station comprising:

a transmitter for transmitting downlink (DL) traffic to subscriber units;

a receiver for receiving uplink (UL) traffic from the subscriber units; and

one or more processors having a media access control (MAC) module configured to

detect a bandwidth request in UL data received from a subscriber unit and identify in the bandwidth request a requested amount of UL bandwidth pertaining to a UL queue established at the subscriber unit;

determine if the requested amount of bandwidth is available;

allocate to the subscriber unit an UL bandwidth grant based on the requested amount and the bandwidth available for UL data, wherein the UL bandwidth grant is allocated to the subscriber unit for distribution between the connections established at the subscriber unit, without any control from the base station; and

a memory for storing a logical view of UL queues maintained by the subscriber unit, the queues being maintained based on the bandwidth requests received from the subscriber unit.

12. A base station for communication with a plurality of subscriber units connected in a wireless communication system, comprising:

a transmitter for transmitting downlink (DL) data to subscriber units;

one or more processors;

a low level media access arbiter (LL-MAA) on the one or more processors controlling bandwidth allocation between a group of subscriber units sharing a communication link, by allocating an amount of uplink (UL) bandwidth to a subscriber unit on request; and

a high layer media access arbiter (HL-MAA) on the one or more processors, logically coupled with the LL-MAA process for controlling communication over a plurality of communication links, including the communication link to the subscriber unit, using a traffic shaping algorithm.

13. A base station as claimed in claim 12, wherein the LL-MAA process comprises a set of downlink (DL) queues, each queue for accumulating DL data received for connections with a similar quality of service (QoS) which is ready to be transmitted to the subscriber unit, the LL-MAA being configured to distribute the DL bandwidth between the queues of the set of queues.

14. A base station as claimed in claim 13, wherein the LL-MAA process uses one of a fair weighted queuing method and a round robin queuing method for distributing the DL bandwidth between the queues of the set of queues.

15. A base station as claimed in claim 14, wherein the method takes into account a QoS granted to each connection, a modulation scheme used for data transmission and a fairness criterion used by the base station to stop the subscriber unit from using up all available bandwidth.

16. A base station as claimed in claim 13, wherein the LL-MAA process is further configured

to reconstruct a logical view of the state of UL data queues maintained at the subscriber units of the group, the logical queues being reconstructed based on the bandwidth requests received from the group of subscriber stations.

17. A base station as claimed in claim 16, wherein the amount of uplink (UL) bandwidth allocated to the subscriber unit is determined based on the state of the UL data queues maintained at the subscriber units of the group.

18. A base station as claimed in claim 16, wherein the amount of uplink (UL) bandwidth allocated to the subscriber unit is determined based on the state of the logical queues maintained at the base station.

19. A method of allocating bandwidth to subscriber units from a base station operating in a wireless communication system, comprising:

initiating a polling action by allocating an unrequested amount of UL bandwidth to a subscriber unit for enabling the subscriber unit to transmit a bandwidth request;

detecting the bandwidth request in uplink (UL) data received from a subscriber unit;

identifying in the bandwidth request a requested amount of UL bandwidth pertaining to one or more of a plurality of UL queues at the subscriber unit;

determining if the requested amount of bandwidth is available;

allocating to the subscriber unit an UL bandwidth grant based on the requested amount of bandwidth and the bandwidth available for the UL data, the UL bandwidth grant being for distribution between one or more connections by the subscriber unit.

20. A method as claimed in claim 19, wherein the base station implicitly informs the subscriber unit that the bandwidth request has been processed by allocating to said subscriber unit the bandwidth grant.

21. A method as claimed in claim 19, wherein, further comprising:

identifying an explicit message received from the subscriber unit requesting an allocation of uplink (UL) bandwidth in which to transmit the bandwidth request; and

providing an allocation of UL bandwidth to the subscriber unit for enabling the subscriber unit to transmit the bandwidth request to the base station.

22. A method as claimed in claim 21, further comprising providing an allocation of uplink (UL) bandwidth to a group of subscriber units for enabling the subscriber units to transmit a respective bandwidth request.

23. A method as claimed in claim 19, wherein the bandwidth request is identified within UL bandwidth allocated to the subscriber unit for traffic.

24. A method as claimed in claim 19, wherein the polling action is performed individually on inactive subscriber units.

25. A method as claimed in claim 19, wherein the polling action is performed individually on active subscriber units which request explicitly to be polled.

26. A method as claimed in claim 19, wherein the polling action is performed on a group of active subscriber units that do not request explicitly to be polled.

27. A method as claimed in claim 26, wherein an active subscriber unit responds to the polling action using a modulation scheme currently used by the subscriber unit for data transmission.

28. A method as claimed in claim 26, wherein an active subscriber unit responds to the polling action using a modulation scheme no less robust than the most robust modulation scheme currently used by a member of the group.

29. A method as claimed in claim 25, wherein the active subscriber unit responds to the polling action using a modulation scheme currently used by the subscriber unit for data transmission.