Wireless network throughput enhancement through channel aware scheduling

• US 8,547,899 B2
• Filed: 07/28/2008
• Issued: 10/01/2013
• Est. Priority Date: 07/28/2007
• Status: Active Grant

• Current Assignee: Ruckus IP Holdings LLC
• Original Assignee: Ruckus Wireless, Inc. (CommScope Holding Company, Inc.)
• Inventors: Kish, William S.
• Primary Examiner(s): Ngo, Ricky
• Assistant Examiner(s): Chang, Richard K
• Application Number:
  US12/181,274
• Publication Number:
  US 20090028095A1
• Time in Patent Office: 1,891 Days
• Field of Search: 370/328, 370/412, 370/230, 370/395.4, 370/235, 370/331, 455/436
• US Class Current: 370/328
• CPC Class Codes: H04W 72/535 based on resource usage policies
• CPC Class Codes: H04W 72/569 of the traffic information
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A channel aware scheduler (CAS) is disclosed that takes advantage of changing wireless channel conditions in order to maximize aggregated system throughput. The CAS is aware of the different channel conditions for one or more stations and adjusts its scheduling of packet transmissions in light of the same. A related CAS algorithm may take advantage of that knowledge in order to increase aggregated system throughput while concurrently addressing other potential fairness constraints.

Claims

1. A system for increasing wireless network throughput, the system comprising:

a classifier that assigns a packet to one of a plurality of transmission queues;

a first hierarchical scheduling module stored in a non-transitory computer-readable medium and that is executable by a processing device to select an assigned packet for transmission from one of the plurality of transmission queues in accordance with a strict priority schedule specifying an order of the transmission queues, the order based on packet content type; and

a second hierarchical scheduling module stored in a non-transitory computer-readable medium and that is executable by a processing device to select a priority scheduled packet for transmission, wherein the selection is made in accordance with a weighted scheduling technique utilizing weighted round robin for determining a weight for each queue and assigning queue weights to stations within each transmission queue, wherein a failed packet is requeued for deferred retransmission at a station queue from which the failed packet originated.

2. The system of claim 1, wherein the second hierarchical scheduling module is further executable to initiate transmission of pending packets for another queue upon receipt of a retransmission request.

3. The system of claim 1, further comprising a credit register associated with each of the plurality of transmission queues, wherein the credit register is decremented for each re-transmission request received for a packet transmitted from the transmission queue.

4. The system of claim 3, wherein decrementing a credit register for a transmission queue to zero activates another transmission queue.

5. The system of claim 1, further comprising a feedback module stored in a non-transitory computer-readable medium and executable by a processing device to modify a queue weight assigned to a transmission queue such that the scheduler favors stations with a more efficient channel.

6. A method for increasing wireless throughput, the method comprising:

assigning a packet to one of a plurality of transmission queues;

executing a first hierarchical scheduling module to select an assigned packet for transmission from one of the plurality of transmission queues in accordance with a priority schedule specifying an order of the transmission queues, the order based on packet content type;

executing a second hierarchical scheduling module to select a priority scheduled packet for transmission in accordance with a weighted scheduling technique utilizing weighted round robin for determining a weight for each queue and assigning queue weights to stations within each transmission queue; and

transmitting the packet, wherein a failed packet is requeued for deferred retransmission at a station queue from which the failed packet originated.

7. The method of claim 6, wherein aggregate system throughput is increased while maintaining at least one potential fairness constraint.

8. The method of claim 6, further comprising modifying the queue weights associated with the weighted scheduling technique to reflect channel conditions, the queue weights favoring stations with a higher quality channel.

9. The method of claim 8, wherein the queue weights associated with the weighted scheduling technique are proportional to channel capacities.

10. The method of claim 9, wherein channel capacity is increased.

11. A non-transitory computer-readable storage medium having embodied thereon a program, the program being executable by a processing device to perform a method for increasing wireless throughput, the method comprising:

assigning a packet to one of a plurality of transmission queues;

selecting an assigned packet for transmission from one of the plurality of transmission queues in accordance with a priority schedule specifying an order of the transmission queues, the order based on packet content type;

selecting a priority scheduled packet for transmission in accordance with a weighted scheduling technique utilizing weighted round robin for determining a weight for each queue and assigning queue weights to stations within each transmission queue; and

transmitting the packet, wherein a failed packet is requeued for deferred retransmission at a station queue from which the failed packet originated.

12. The non-transitory computer-readable storage medium of claim 11, wherein the program is further executable to modify the queue weights associated with the weighted scheduling technique to reflect channel conditions, the queue weights favoring stations with a higher quality channel.

13. The non-transitory computer-readable storage medium of claim 12, wherein queue weights associated with the weighted scheduling technique are proportional to channel capacities.

14. The non-transitory computer-readable storage medium of claim 12, wherein aggregate system throughput is increased while maintaining at least one potential fairness constraint.