Congestion Control in Wireless Mesh Networks

• US 20090232001A1
• Filed: 03/11/2008
• Published: 09/17/2009
• Est. Priority Date: 03/11/2008
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Hart, Brian Donald, Gong, Xiaohong, Kruys, Johannes Petrus, O'Hara, Robert B. JR.
• Granted Patent: US 7,843,817 B2
• Time in Patent Office: Days
• US Class Current: 370/236
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/115 using a dedicated packet
• CPC Class Codes: H04L 47/122 by diverting traffic away from congested entities
• CPC Class Codes: H04L 47/30 in combination with information about buffer occupancy at either end or at transit nodes
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames
• CPC Class Codes: H04W 28/0289 Congestion control load shedding arrangements in network planning H04W16/08; performing reselection for handling the traffic H04W36/22; wireless traffic scheduling H04W72/12
• CPC Class Codes: H04W 28/12 using signalling between network elements
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]

Abstract

A congestion control system. In particular implementations, a method includes receiving packets into one or more queues and monitoring the one or more queues for congestion. The method also includes, if a number of packets in the one or more queues exceeds a first threshold, determining a congestion control mode. The method also includes generating a congestion control message indicating the congestion control mode and transmitting the congestion control message to one or more neighboring mesh nodes.

Claims

1. A method comprising:

receiving packets into one or more queues;

monitoring the one or more queues for congestion;

if a number of packets in the one or more queues exceeds a first threshold, determining a congestion control mode;

generating a congestion control message indicating the congestion control mode; and

transmitting the congestion control message to one or more neighboring mesh nodes.

2. The method of claim 1 further comprising:

if the number of packets in a given queue exceeds the first threshold, determining whether there are one or more primary congested nodes;

if there are one or more primary congested nodes, entering a first congestion control mode if the number of packets exceeds a second threshold; and

if there are one or more primary congested nodes, entering a second congestion control mode if the number of packets does not exceed the second threshold.

3. The method of claim 1 further comprising:

if there are no primary congested nodes, entering a third congestion control mode if the number of packets exceeds a third threshold; and

if there are no primary congested nodes and if the number of packets does not exceed the third threshold, entering a fourth congestion control mode.

4. The method of claim 1 wherein the one or more neighboring mesh nodes comprise one or more of parent nodes and child nodes.

5. The method of claim 1 wherein the one or more queues are associated with a particular node.

6. Logic encoded in one or more tangible media for execution and when executed operable to:

receive packets into one or more queues;

monitor the one or more queues for congestion;

if a number of packets in the one or more queues exceeds a first threshold, determine a congestion control mode;

generate a congestion control message indicating the congestion control mode; and

transmit the congestion control message to one or more neighboring mesh nodes.

7. The logic of claim 6 wherein the logic is further operable to:

if the number of packets in a given queue exceeds the first threshold, determining whether there are one or more primary congested nodes;

if there are one or more primary congested nodes, entering a first congestion control mode if the number of packets exceeds a second threshold; and

if there are one or more primary congested nodes, entering a second congestion control mode if the number of packets does not exceed the second threshold.

8. The logic of claim 6 wherein the logic is further operable to:

if there are no primary congested nodes, enter a third congestion control mode if the number of packets exceeds a third threshold; and

if there are no primary congested nodes and if the number of packets does not exceed the third threshold, enter a fourth congestion control mode.

9. The logic of claim 6 wherein the one or more neighboring mesh nodes comprise one or more of parent nodes and child nodes.

10. The logic of claim 6 wherein the one or more queues are associated with a particular node.

11. A method comprising:

receiving a congestion control message;

if the congestion control message indicates a first congestion control mode, buffering all traffic from one or more signaling nodes; and

if the congestion control message indicates a second congestion control mode, remapping traffic from the signaling node to a different queue.

12. The method of claim 11 further comprising:

if the congestion control message indicates a third congestion control mode, buffering traffic from a signaling node that is destined for one or more congested nodes; and

if the congestion control message indicates a forth congestion control mode, remapping traffic to the identified one or more congested nodes.

13. The method of claim 11 wherein the different queue is a next lowest queue.

14. The method of claim 11 wherein the different queue is allocated for congestion mitigation.

15. Logic encoded in one or more tangible media for execution and when executed operable to:

receive a congestion control message;

if the congestion control message indicates a first congestion control mode, buffer all traffic from one or more signaling nodes; and

if the congestion control message indicates a second congestion control mode, remap traffic from the signaling node to a different queue.

16. The logic of claim 15 wherein the logic is further operable to:

if the congestion control message indicates a third congestion control mode, buffer traffic from a signaling node that is destined for one or more congested nodes; and

if the congestion control message indicates a forth congestion control mode, remap traffic to the identified one or more congested nodes.

17. The logic of claim 15 wherein the different queue is a next lowest queue.

18. The logic of claim 15 wherein the different queue is allocated for congestion mitigation.

19. An apparatus comprising:

one or more processors;

one or more transmit queues;

a memory;

one or more wireless mesh network interfaces; and

logic encoded in one or more tangible media for execution and when executed operable to cause the one or more processors to;

receive a congestion control message;

if the congestion control message indicates a first congestion control mode, buffer all traffic from one or more signaling nodes; and

if the congestion control message indicates a second congestion control mode, remap traffic from the signaling node to a different queue.

20. The apparatus of claim 19 wherein the logic is further operable to cause the one or more processors to:

if the congestion control message indicates a third congestion control mode, buffer traffic from a signaling node that is destined for one or more congested nodes; and

if the congestion control message indicates a forth congestion control mode, remap traffic to the identified one or more congested nodes.

21. The apparatus of claim 19 wherein the different queue is a next lowest queue.

22. The apparatus of claim 19 wherein the different queue is allocated for congestion mitigation.