System and method for detecting transient links in multi-hop wireless networks

• US 20060023632A1
• Filed: 07/26/2005
• Published: 02/02/2006
• Est. Priority Date: 07/27/2004
• Status: Abandoned Application

• Current Assignee: MeshNetworks, Inc. (Motorola Solutions, Inc.)
• Original Assignee: MeshNetworks, Inc. (Motorola Solutions, Inc.)
• Inventors: Zeng, Surong, Ozer, Sebnem Z.
• Application Number:
  US11/189,617
• Publication Number:
  US 20060023632A1
• Time in Patent Office: Days
• US Class Current: 370/248
• CPC Class Codes: H04L 41/5009 Determining service level performance parameters or violations of service level contracts, e.g. violations of agreed response time or mean time between failures [MTBF]
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04L 43/0829 Packet loss
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements

Abstract

The present invention provides a system and method to detect transient links in a timely and reliable way. The present invention introduces a metric that depends on the unicast data timeout measurements at the receiver node (102, 106, 107). This metric can be combined with existing solutions to estimate the link quality between nodes (102, 106, 107). Furthermore, the present invention takes the packet size into consideration when transceivers (108) update the link quality based on the packet completion rate to quantify the transient link quality more precisely.

Claims

1. A method for detecting a transient link in a wireless network, the method comprising:

transmitting data between a transmitting node and a receiving node;

counting data timeouts that occur at the receiving node; and

determining whether a link between the transmitting and receiving nodes is a transient link based on a counted number of data timeouts.

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

the counting step comprises controlling at least one of the transmitting node and the receiving node to count the data timeouts.

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

the controlling step comprises controlling the transmitting and receiving nodes to count the data timeouts.

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

assessing the quality of the link based on the counted number of data timeouts; and

the determining step identifies the link as a transient link when the quality of the link is below a desired criteria.

5. A method as claimed in claim 4, wherein:

the determining step determines a level of unreliability of the transient link based on a value of the quality of the link.

6. A method as claimed in claim 4, wherein:

the assessing step adjusts a quality value representing the quality of the link based on the counted number of data timeouts and the respective sizes of the data packets for which timeout occurred.

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

the assessing step adjusts the quality value by a large amount when timeout occurs for a small data packet and by a small amount when timeout occurs for large data packet.

8. A method as claimed in claim 4, wherein:

the adjusting step comprises determining the respective size of a respective data packet based on information included in a request-to-send (RTS) message sent by the transmitting node.

9. A system for detecting a transient link in a wireless network, the system comprising:

a transmitting node and a receiving node, the transmitting node being adapted to transmit data to the receiving node;

a controller, adapted to count data timeouts that occur at the receiving node, and adapted to determine whether a link between the transmitting and receiving nodes is a transient link based on a counted number of data timeouts.

10. A system as claimed in claim 9, wherein:

the controller comprises at least one of the following to count the data timeouts;

a transmitting node controller disposed at the transmitting node; and

a receiving node controller disposed at the receiving node.

11. A system as claimed in claim 10, wherein:

the controller comprises transmitting and receiving node controllers disposed respectively at the transmitting and receiving nodes to count the data timeouts.

12. A system as claimed in claim 9, wherein:

the controller is further adapted to assess the quality of the link based on the counted number of data timeouts, and to identify the link as a transient link when the quality of the link is below a desired criteria.

13. A system as claimed in claim 12, wherein:

the controller is adapted to determine a level of unreliability of the transient link based on a value of the quality of the link.

14. A system as claimed in claim 12, wherein:

the controller is further adapted to adjust a quality value representing the quality of the link based on the counted number of data timeouts and the respective sizes of the data packets for which timeout occurred.

15. A system as claimed in claim 14, wherein:

the controller is adapted to adjust the quality value by a large amount when timeout occurs for a small data packet and by a small amount when timeout occurs for large data packet.

16. A system as claimed in claim 12, wherein:

the controller is adapted to determine the respective size of a respective data packet based on information included in a request-to-send (RTS) message sent by the transmitting node.

17. A node, adapted for use in a wireless network, the node comprising:

a transceiver, adapted to transmit data to another node in the wireless network; and

a controller, adapted to count data timeouts that occur at the another node, and adapted to determine whether a link between the node and the another node is a transient link based on a counted number of data timeouts.

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

the controller is further adapted to assess the quality of the link based on the counted number of data timeouts, and to identify the link as a transient link when the quality of the link is below a desired criteria.

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

the controller is further adapted to adjust a quality value representing the quality of the link based on the counted number of data timeouts and the respective sizes of the data packets for which timeout occurred.

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

the controller is adapted to adjust the quality value by a large amount when timeout occurs for a small data packet and by a small amount when timeout occurs for large data packet.