System and method for providing quality of service provisions and congestion control in a wireless communication network

• US 20060087974A1
• Filed: 10/27/2005
• Published: 04/27/2006
• Est. Priority Date: 10/27/2004
• Status: Active Grant

• Current Assignee: Bison Patent Licensing, LLC
• Original Assignee: MeshNetworks, Inc. (Motorola Solutions, Inc.)
• Inventors: Zeng, Surong, Ozer, Sebnem Z., Barker, Charles R. Jr.
• Granted Patent: US 7,733,766 B2
• Time in Patent Office: Days
• US Class Current: 370/235
• CPC Class Codes: H04L 12/2854 Wide area networks, e.g. public data networks
• CPC Class Codes: H04L 47/11 Identifying congestion
• CPC Class Codes: H04L 47/12 Avoiding congestion; Recovering from congestion
• CPC Class Codes: H04L 47/263 Rate modification at the source after receiving feedback
• CPC Class Codes: H04L 47/30 in combination with information about buffer occupancy at either end or at transit nodes
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/0242 Determining whether packet losses are due to overload or to deterioration of radio communication conditions
• CPC Class Codes: H04W 28/0284 detecting congestion or overload during communication monitoring arrangements H04L43/00
• CPC Class Codes: H04W 28/12 using signalling between network elements
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A system and method for providing a traffic control scheme for QoS provision and congestion control across multiple interfaces of wireless nodes (102, 106 and 107), such as wireless access points (107 and 106), communicating in a wireless multihopping communication network (100). The nodes (102, 106 and 107) can include multiple transceivers. The system and method detects bottleneck interfaces in these nodes (102, 106, 107) to control the traffic along the path of the corresponding traffic flow. Different measurements and cross-layer feedback are used to differentiate the cause of the congestion, such as wireless link quality degradation due to fading or degradation due to congestion in a shared medium. The nodes (102, 106, 107) inform each other on the status of their congestion level. High and low level signaling and interruption mechanisms are used to control the interfaces of the congested node (102, 106 or 107) to adjust traffic flow and alleviate the congestion.

Claims

1. A method for responding to congestion in a wireless communication network, the wireless network comprising a plurality of nodes and at least one access point adapted to provide at least one of the nodes with access to another network, the method comprising:

operating an access point to evaluate an amount of traffic that the access point is receiving and an amount of traffic that the access point is transmitting;

determining whether congestion exists at the access point based on the evaluated amounts of received and transmitted traffic;

when the access point determines that congestion exists, operating the access point to transmit a message including information pertaining to the congestion; and

operating those of the nodes that receive the message to determine whether to adjust their respective transmission rates based on the information pertaining to the congestion included in the message.

2. A method as claimed in claim 1, further comprising:

when the access point determines that congestion exists, operating the access point to determine a reason for the congestion, and to include information pertaining to the reason for the congestion in the message.

3. A method as claimed in claim 2, wherein:

the step of operating the access point to determine the reason for congestion comprises operating the access point to determine whether the congestion is caused by a characteristic of a link between the access point and one of the other nodes or traffic among those of the other nodes neighboring the access point.

4. A method as claimed as claimed in claim 1, further comprising:

operating the nodes that received the message to transmit another message including information pertaining to the congestion of the access point.

5. A method as claimed in claim 1, wherein:

when the access point determines that the congestion no longer exists, operating the access point to transmit a message including information indicating an absence of congestion.

6. A method as claimed in claim 1, wherein:

the step of operating those nodes that receive the message comprises operating those nodes to lower their respective transmission rates for transmissions to the access point.

7. A method for operating a node in a wireless communication network to assess congestion, the method comprising:

operating the node to evaluate an amount of traffic that the node is receiving and an amount of traffic that the node is transmitting;

operating the node to determine whether congestion exists at the node based on the evaluated amounts of received and transmitted traffic; and

when the node determines that congestion exists, operating the node to transmit a message including information pertaining to the congestion.

8. A method as claimed in claim 7, further comprising:

when the node determines that congestion exists, operating the node to determine a reason for the congestion, and to include information pertaining to the reason for the congestion in the message.

9. A method as claimed in claim 8, wherein:

the step of operating the node to determine the reason for congestion comprises operating the node to determine whether the congestion is caused by a characteristic of a link between the node and another node in the network or traffic among other nodes neighboring the node.

10. A method as claimed in claim 7, wherein:

when the node determines that the congestion no longer exists, operating the node to transmit a message including information indicating an absence of congestion.

11. A wireless communication network, comprising:

a plurality of nodes; and

at least one access point, adapted to provide at least one of the nodes with access to another network;

the access point being further adapted to evaluate an amount of traffic that the access point is receiving and an amount of traffic that the access point is transmitting, to determine whether congestion exists at the access point based on the evaluated amounts of received and transmitted traffic, and to transmit a message including information pertaining to the congestion when the access point determines that congestion exists; and

the nodes that receive the message are adapted to determine whether to adjust their respective transmission rates based on the information pertaining to the congestion included in the message.

12. A wireless communication network as claimed in claim 11, wherein:

the access point is further adapted to determine a reason for the congestion, and to include information pertaining to the reason for the congestion in the message.

13. A wireless communication network as claimed in claim 12, wherein:

the access point is further adapted to determine whether the congestion is caused by a characteristic of a link between the access point and one of the other nodes or traffic among those of the other nodes neighboring the access point.

14. A wireless communication network as claimed as claimed in claim 11, wherein:

the nodes that received the message are further adapted to transmit another message including information pertaining to the congestion of the access point.

15. A wireless communication network as claimed in claim 11, wherein:

the access point is further adapted to transmit a message including information indicating an absence of congestion when the access point determines that the congestion no longer exists.

16. A wireless communication network as claimed in claim 11, wherein:

the nodes that receive the message are further adapted to lower their respective transmission rates for transmissions to the access point.

17. A node of a wireless communication, the node comprising:

at least one transceiver; and

a controller, adapted to evaluate an amount of traffic that the transceiver is receiving and an amount of traffic that the transceiver is transmitting, to determine whether congestion exists at the node based on the evaluated amounts of received and transmitted traffic, and to control the transceiver to transmit a message including information pertaining to the congestion when the controller determines that congestion exists.

18. A node as claimed in claim 17, wherein:

the controller is further adapted to determine a reason for the congestion, and to include information pertaining to the reason for the congestion in the message.

19. A node as claimed in claim 18, wherein:

the controller is further adapted to determine whether the congestion is caused by a characteristic of a link between the node and another node in the network or traffic among other nodes neighboring the node.

20. A node as claimed in claim 17, wherein:

the controller is further adapted to control the transceiver to transmit a message including information indicating an absence of congestion when the controller determines that the congestion no longer exists.