Multi-user MAC protocol for a local area network

• US 7,873,049 B2
• Filed: 06/28/2006
• Issued: 01/18/2011
• Est. Priority Date: 06/28/2006
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Tavares, Clifford, Gaur, Sudhanshu
• Primary Examiner(s): Ryman; Daniel J
• Assistant Examiner(s): ROBERTS, BRIAN S
• Application Number:
  US11/477,727
• Publication Number:
  US 20080002636A1
• Time in Patent Office: 1,665 Days
• Field of Search: 370/417, 370/418
• US Class Current: 370/392
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04W 72/1273 of downlink data flows
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02

Abstract

A system comprises a station manager for associating a queue block to each active station in a network, each queue block being configured to implement a contention-based process, e.g., IEEE 802.11e, to select a winning frame from a set of frames; a multiplexer for receiving frames, each frame having a destination address, and for routing each received frame to a queue block based on the destination address; an access controller for receiving the winning frame from each queue block, for forwarding the winning frame(s) to a physical layer for simultaneous transmission to the active station(s) when the number of winning frames is equal to or below a threshold greater than one, and for forwarding a subset of the winning frames to the physical layer for simultaneous transmission to the active stations when the number of winning frames is above the threshold; and a physical layer capable of simultaneous frame transmission.

Claims

1. A method implementing a multi-user media access control (MAC) layer in a broadband wireless access network, the method comprising:

creating, at the multi-user MAC layer, a queue block dedicated to one or more active stations in the broadband wireless access network;

receiving frames at a layer above the multi-user MAC layer, each frame having a destination address identifying an active station;

routing each frame to a queue block at the multi-user MAC layer based on the destination address;

performing a contention-based process by each queue block having at least one frame at the multi-user MAC layer;

receiving, at an access controller, a winning frame from each queue block that performs the contention-based process;

when the number of one or more winning frames is equal to or below a threshold greater than one, then forwarding the one or more winning frames to a physical layer for simultaneous transmission to the one or more active stations; and

when the number of the one or more winning frames is above the threshold, then forwarding a subset of the one or more winning frames to the physical layer for simultaneous transmission to the one or more active stations,

wherein the contention-based process is performed at each queue block and includes an IEEE802.11e process which provides quality of service (QoS) differentiation by grouping data traffic in the broadband wireless access network into four access classes including voice, video, best effort, and background; and

wherein the voice access class has the highest priority, the video access class has the second highest priority, the best effort access class has the third highest priority, and the background access has the lowest priority.

2. The method of claim 1,

wherein the method is performed by a wireless access point.

3. The method of claim 1, wherein the threshold is related to the number of simultaneous channels available to the physical layer.

4. The method of claim 1, wherein the subset of the one or more winning frames includes a number of frames equal to the threshold.

5. The method of claim 1, further comprising instantiating queue blocks based on the number of the one or more active stations.

6. The method of claim 1, further comprising

when a difference between the number of the one or more winning frames and the threshold is greater than the threshold, then forwarding another subset of the one or more winning frames to the physical layer for simultaneous transmission to the one or more active stations during a subsequent time slot.

7. The method of claim 1, further comprising

when a difference between the number of the one or more winning frames and the threshold is less than or equal to the threshold, then forwarding the one or more winning frames to the physical layer for simultaneous transmission to the one or more active stations during a subsequent time slot.

8. The method of claim 1, further comprising

associating with the one or more winning frame to be forwarded to the physical layer a time offset that informs the one or more active stations when to send an acknowledgement (ACK) frame, thus enabling a time shared uplink for acknowledgement (ACK) frames without contention.

9. The method of claim 1,

wherein at least two winning frames to be forwarded to the physical layer have different sizes, one frame being smaller and one frame being larger;

and

further comprising appending dummy data to the smaller frame so that the smaller frame with dummy data is the same size as the larger frame.

10. The method of claim 1,

wherein each queue block is created to be dedicated to only one active station and to function independently of other queue blocks.