System and method for aggregation and queuing in a wireless network

• US 20080159319A1
• Filed: 12/28/2006
• Published: 07/03/2008
• Est. Priority Date: 12/28/2006
• Status: Active Grant

• Current Assignee: Trapeze Networks Incorporated (Juniper Networks Incorporated)
• Original Assignee: Trapeze Networks Incorporated (Juniper Networks Incorporated)
• Inventors: Bennett, Richard Thomas, Gast, Matthew Stuart
• Granted Patent: US 7,873,061 B2
• Time in Patent Office: Days
• US Class Current: 370/412
• CPC Class Codes: H04L 47/50 Queue scheduling
• CPC Class Codes: H04L 47/564 Attaching a deadline to packets, e.g. earliest due date first
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/9023 for implementing a jitter-buffer
• CPC Class Codes: H04W 72/569 of the traffic information
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A technique for improved throughput at an access point (AP) involves when frames are received for transmission by the AP, queuing the frames for a particular station. A system constructed according to the technique may include an aggregation and queuing layer. Station queues may be processed by the aggregation and queuing layer before being given to radio hardware for transmission. In an illustrative embodiment, when frames are received by the aggregation and queuing layer, the packet will be assigned a target delivery time (TDT) and an acceptable delivery time (ADT). The TDT is the “ideal” time to transmit a frame, based on its jitter and throughput requirements. Frames are mapped on to a time axis for transmission by TDT. In an illustrative embodiment, each frame is mapped by priority, so that there are separate maps for voice, video, best effort, and background frames. There will be gaps between frames for transmission that can be used for aggregation.

Claims

1. A system comprising:

an access point (AP), including;

one or more ingress queues;

one or more egress queues;

an aggregation and queuing engine coupling the ingress queues to the egress queues;

radio hardware coupled to the egress queues;

wherein, in operation, the aggregation and queuing engine;

assigns target delivery time (TDT) to a first packet having a first destination, a second packet having the first destination, and a third packet having a second destination in the ingress queues,

maps the first packet, the second packet, and the third packet onto a time axis for transmission by TDT, where the first packet and the third packet are adjacent on the time axis,

aggregates the first packet with the second packet if a gap between the first packet and the third packet is large enough that aggregating and sending the first packet and the second packet allows the first packet to be sent in the first packet TDT and the third packet to be sent in the third packet TDT,

enqueues the aggregated first packet and second packet, and the third packet, on the egress queues;

wherein, in operation, the radio hardware dequeues and sends packets enqueued on the egress queues.

2. The system of claim 1, further comprising a distribution system coupled to the AP.

3. The system of claim 1, further comprising a plurality of stations coupled to the AP.

4. The system of claim 1, further comprising one or more stations wirelessly connected to the AP, wherein the one or more ingress queues are associated with the one or more stations.

5. The system of claim 1, wherein the one or more ingress queues each include a plurality of sub-queues associated with packet transmission priorities.

6. The system of claim 1, wherein each of the one or more egress queues is associated with each of a plurality of priorities.

7. The system of claim 1, wherein, the third packet immediately follows the first packet on the time axis, wherein, in operation, the aggregation and queuing engine:

appends the second packet to the first packet if the gap between the first packet and the third packet is large enough that aggregating and sending the first packet and the second packet allows the first packet to be sent in the first packet TDT and the third packet to be sent in the third packet TDT,

enqueues the third packet, after the aggregated first packet and second packet, on the egress queues.

8. The system of claim 1, wherein, the first packet immediately follows the third packet on the time axis, wherein, in operation, the aggregation and queuing engine:

aggregates the second packet with the first packet if the gap between the first packet and the third packet is large enough that aggregating and sending the first packet and the second packet allows the first packet to be sent in the first packet TDT and the third packet to be sent in the third packet TDT,

enqueues the third packet, before the aggregated first packet and second packet, on the egress queues.

9. The system of claim 8, wherein the second packet is appended to the first packet.

10. The system of claim 1, wherein, in operation, the aggregation and queuing engine provides data to the radio hardware sufficient to inform at least one station regarding when a medium is predicted to be busy.

11. A system comprising:

a means for;

assigning a first target delivery time (TDT) to a first packet having a first destination;

assigning a second TDT to a second packet having the first destination;

assigning a third TDT to a third packet having a second destination,

a means for mapping the first packet, the second packet, and the third packet onto a time axis for transmission by TDT, where the first packet and the third packet are adjacent on the time axis,

a means for determining that a gap between the first packet and the third packet is large enough that aggregating and sending the first packet and the second packet allows the first packet to be sent in the first TDT and the third packet to be sent in the third TDT;

a means for aggregating the first packet and the second packet;

a means for;

transmitting the aggregated first packet and the second packet to the first destination;

transmitting the third packet to the second destination.

12. The system of claim 11, wherein, the third packet immediately follows the first packet on the time axis, wherein:

the means for aggregating further includes a means for appending the second packet to the first packet if the gap between the first packet and the third packet is large enough that aggregating and sending the first packet and the second packet allows the first packet to be sent in the first TDT and the third packet to be sent in the third TDT,

the means for transmitting further includes a means for transmitting the third packet after transmitting the aggregated first packet and second packet.

13. The system of claim 11, wherein, the first packet immediately follows the third packet on the time axis, further comprising:

the means for aggregating further includes a means for aggregating the second packet with the first packet if the gap between the first packet and the third packet is large enough that aggregating and sending the first packet and the second packet allows the first packet to be sent in the first TDT and the third packet to be sent in the third TDT,

the means for transmitting further includes a means for transmitting the third packet before the aggregated first packet and second packet.

14. The system of claim 13, wherein the second packet is appended to the first packet.

15. The system of claim 11, further comprising informing at least one station regarding when a wireless medium is predicted to be busy.

16. A method comprising:

assigning a first target delivery time (TDT) to a first packet having a first destination;

assigning a second TDT to a second packet having the first destination;

assigning a third TDT to a third packet having a second destination,

mapping the first packet, the second packet, and the third packet onto a time axis for transmission by TDT, where the first packet and the third packet are adjacent on the time axis,

determining that a gap between the first packet and the third packet is large enough that aggregating and sending the first packet and the second packet allows the first packet to be sent in the first TDT and the third packet to be sent in the third TDT;

aggregating the first packet and the second packet;

transmitting the aggregated first packet and the second packet to the first destination;

transmitting the third packet to the second destination.

17. The method of claim 16, wherein, the third packet immediately follows the first packet on the time axis, further comprising:

appending the second packet to the first packet if the gap between the first packet and the third packet is large enough that aggregating and sending the first packet and the second packet allows the first packet to be sent in the first TDT and the third packet to be sent in the third TDT,

transmitting the third packet after transmitting the aggregated first packet and second packet.

18. The method of claim 16, wherein, the first packet immediately follows the third packet on the time axis, further comprising:

aggregating the second packet with the first packet if the gap between the first packet and the third packet is large enough that aggregating and sending the first packet and the second packet allows the first packet to be sent in the first TDT and the third packet to be sent in the third TDT,

transmitting the third packet before the aggregated first packet and second packet.

19. The method of claim 18, wherein the second packet is appended to the first packet.

20. The method of claim 16, further comprising informing at least one station regarding when a wireless medium is predicted to be busy.