Multi-user MAC protocol for a local area network

• US 20080002636A1
• Filed: 06/28/2006
• Published: 01/03/2008
• Est. Priority Date: 06/28/2006
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Tavares, Clifford, Gaur, Sudhanshu
• Granted Patent: US 7,873,049 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• 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, comprising:

associating a queue block to each active station in a network;

receiving frames, each frame having a destination address identifying an active station;

routing each frame to a queue block based on the destination address;

performing a contention-based process by each queue block having at least one frame;

receiving a winning frame from each queue block that performs the contention-based process;

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

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

2. The method of claim 1,

wherein the method is performed by a wireless access point;

and

wherein the network includes a wireless network.

3. The method of claim 1, wherein the contention-based process includes an IEEE 802.11e process.

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

5. The method of claim 1, wherein the subset of the winning frames includes a number of frames equal to the threshold.

6. The method of claim 1, further comprising instantiating queue blocks based on the number of active stations.

7. The method of claim 1, further comprising

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

8. The method of claim 1, further comprising

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

9. The method of claim 1, further comprising

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

10. 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.

11. A system, comprising:

a station manager for associating a queue block to each active station in a network, the station manager being capable of managing multiple active stations and multiple queue blocks, each queue block being configured to implement a contention-based process 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, the access controller being configured to forward the winning frame or frames to a physical layer for simultaneous transmission to the active station or stations when the number of winning frames is equal to or below a threshold greater than one, the access controller being configured to forward 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 substantially simultaneous frame transmission.

12. The system of claim 11,

wherein the system includes a wireless access point;

and

wherein the network includes a wireless network.

13. The system of claim 11, wherein the threshold is related to the number of simultaneous channels available to the physical layer.

14. The system of claim 11, wherein the subset of the winning frames includes a number of frames equal to the threshold.

15. The system of claim 11, wherein the station manager instantiates queue blocks based on the number of active stations.

16. The system of claim 11, wherein the access controller forwards another subset of winning frames to the physical layer for substantially simultaneous transmission to the active station during a subsequent time slot when the difference between the number of winning frames and the threshold is greater than the threshold.

17. The system of claim 11, wherein the access controller forwards the winning frames to the physical layer for substantially simultaneous transmission to the active station during a subsequent time slot when the difference between the number of winning frames and the threshold is less than or equal to the threshold.

18. The system of claim 11, wherein the access controller associates with the winning frame to be forwarded to the physical layer a time offset that informs the active station when to send an acknowledgement ACK frame, thus enabling a time shared uplink for acknowledgement ACK frames without contention.

19. The system of claim 11,

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

wherein the access controller appends dummy data to the smaller frame so that the smaller frame with dummy data is the same size as the larger frame.

20. A system, comprising:

means for associating a queue block to each active station in a network and for managing multiple active stations and multiple queue blocks, each queue block being configured to implement a contention-based process to select a winning frame from a set of frames;

means for receiving frames, each frame having a destination address, and for routing each received frame to a queue block based on the destination address;

means for receiving the winning frame from each queue block, for forwarding the winning frame or frames for simultaneous transmission to the active station or stations 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 for simultaneous transmission to the active stations when the number of winning frames is above the threshold; and

means for transmitting multiple frames substantially simultaneously.