WIRELESS DEVICE LINK METRIC FOR EFFECTIVE COMPARISON OF MULTI-HOP ROUTES IN WIRELESS MESH NETWORKS

• US 20140213191A1
• Filed: 01/29/2013
• Published: 07/31/2014
• Est. Priority Date: 01/29/2013
• Status: Active Grant

• Current Assignee: Natbreway Pty Ltd
• Original Assignee: Cooper Technologies Company (Eaton Corporation PLC.)
• Inventors: Courtice, Harry John
• Granted Patent: US 9,860,819 B2
• Time in Patent Office: Days
• US Class Current: 455/67.11
• CPC Class Codes: H04L 45/125 based on throughput or bandwidth
• CPC Class Codes: H04W 40/12 based on transmission quality or channel quality

Abstract

Link metrics for communication paths in multi-hop wireless mesh networks of industrial radio device are determined based on signal strength and traffic level performance of each link in the communication paths. A path metric is determined from the link metrics and path metrics are compared and utilized for optimal routing of messages through the network.

Claims

1. An input/output device comprising:

a transmitter configured to generate a radio frequency signal transmission;

a receiver configured to receive a radio frequency signal transmission; and

a processor-based control coordinating transmissions of radio frequency signal transmissions in response to received signal transmissions in a multi-signal path transmission network, the processor-based control configured to;

measure a signal strength value for a first communication link established through at least one neighbouring input/output device;

calculate a signal strength performance metric based on the measured signal strength of the first communication link;

measure a traffic level value observed by the similar input/output device at the remote end of the first communication link established through the at least one input/output device;

calculate a traffic level performance metric based on the measured traffic value of the device at the remote end of the first communication link;

determine a link metric for the first communication link, based on the calculated traffic level performance metric and the calculated traffic level performance metric; and

utilize the first link metric to evaluate a preferred path for routing of a message.

2. The input/output device of claim 1, wherein the determined link metric is the product of the calculated signal strength performance metric and the calculated traffic level performance metric.

3. The input/output device of claim 1, wherein the determined link metric corresponds to a value in a lookup table corresponding to the calculated signal strength performance metric and the calculated traffic level performance metric.

4. The input/output device of claim 1, wherein the signal strength performance metric is calculated in reference to threshold values provided in a signal strength table.

5. The input/output device of claim 4, wherein the signal strength table includes a plurality of threshold signal strength values each arranged in positions 1 through x in the table, and the calculated signal strength performance metric corresponds to the position of the threshold value in the signal strength table that is closest to but higher than the measured signal strength value.

6. The input/output device of claim 1, wherein the traffic level performance metric is calculated in reference to threshold values provided in a traffic level table.

7. The input/output device of claim 6, wherein the traffic level table includes a plurality of threshold traffic level values each arranged in positions 1 through y in the table, and the calculated traffic level performance metric corresponds to the position of the threshold value in the traffic level table that is closest to but lower than the measured traffic level value.

8. The input/output device of claim 1, wherein a communication path includes the first communication link and at least a second communication link, and wherein the processor-based control is further configured to:

measure a signal strength value for the second communication link;

calculate a signal strength performance metric based on the measured signal strength of the second communication link;

measure a traffic level value observed by the input/output device at the remote end of the second communication link;

calculate a traffic level performance metric based on the measured traffic value of the device at the remote end of the second communication link;

determine a link metric for the second communication link, based on the calculated traffic level performance metric and the calculated traffic level performance metric; and

utilize the second link metric to evaluate a preferred path for routing of a message.

9. The input/output device of claim 8, wherein the processor-based control is further configured to:

add the first link metric and the at least second link metric to determine a path metric; and

utilize the path metric to select one of multiple communication paths for routing of the message.

10. A multi-path radio communications network for monitoring and controlling an industrial process, the network comprising:

a plurality of processor-based radio devices configured to wirelessly communicate in a mesh network wherein each radio communicates with multiple other radio devices in the mesh network; and

wherein at least one of the plurality of processor-based radio device is configured to;

measure a signal strength value for a first communication link established through at least one neighbouring radio device;

calculate a signal strength performance metric based on the measured signal strength of the first communication link;

measure a traffic level value observed by the input/output device at the remote end of the first communication link;

calculate a traffic level performance metric based on the measured traffic value of the device at the remote end of the first communication link;

determine a link metric for the first communication link, based on the calculated signal strength performance metric and the calculated traffic level performance metric; and

utilize the link metric to evaluate a preferred path for routing of a message.

11. The communications network of claim 10, wherein the determined link metric is the product of the calculated traffic level performance metric and the calculated traffic level performance metric.

12. The communications network of claim 10, wherein the determined link metric corresponds to a value in a lookup table corresponding to the calculated traffic level performance metric and the calculated traffic level performance metric.

13. The communications network of claim 10, wherein the signal strength performance metric is calculated in reference to threshold values provided in a signal strength table.

14. The communications network of claim 13, wherein the signal strength table includes a plurality of threshold signal strength values each arranged in positions 1 through x in the table, and the calculated signal strength performance metric corresponds to the position of the threshold value in the signal strength table that is closest to but higher than the measured signal strength value.

15. The communications network of claim 10, wherein the traffic level performance metric is calculated in reference to threshold values provided in a traffic level table.

16. The communications network of claim 15, wherein the traffic level table includes a plurality of threshold traffic level values each arranged in positions 1 through y in the table, and the calculated traffic level performance metric corresponds to the position of the threshold value in the traffic level table that is closest to but lower than the measured traffic level value.

17. The communications network of claim 10, wherein a communication path includes the first communication link and at least a second communication link, and wherein the at least one of the plurality of processor-based radio device is configured to:

measure a signal strength value for the second communication link;

calculate a signal strength performance metric based on the measured signal strength of the second communication link;

measure a traffic level value observed by the input/output device at the remote end of the second communication link;

calculate a traffic level performance metric based on the measured traffic value of the device at the remote end of the second communication link;

determine a link metric for the second communication link, based on the calculated signal strength performance metric and the calculated traffic level performance metric; and

utilize the second link metric to evaluate a preferred path for routing of a message.

18. The communications network of claim 17, wherein the at least one of the plurality of processor-based radio devices is further configured to:

add the first link metric and the at least second link metric to determine a path metric; and

utilize the path metric to select one of multiple communication paths for routing of the message.

19. A multi-path radio communications system comprising:

a plurality of processor based radio devices configured to wirelessly communicate with one another in a mesh network having a frequency hopping spread spectrum topology, each of the plurality of processor based radio devices configured to;

measure a signal strength value for a first communication link established through at least one neighbouring radio;

calculate a signal strength performance metric based on the measured signal strength for the first communication link;

measure a traffic level value observed by the input/output device at the remote end of the first communication link;

calculate a traffic level performance metric based on the measured traffic value of device at the remote end of the first communication link;

determine a link metric for the first communication link, based on the calculated signal strength performance metric and the calculated traffic level performance metric; and

utilize the link metric to evaluate a preferred path for routing of a message.

20. The multi-path radio communications system wherein each of the plurality of processor based radio devices is further configured to:

identify a plurality of communication paths to a destination radio device, at least one the plurality identified communication paths including a multi-hop communication path including a plurality of communication links between respective ones of the plurality of processor based radio devices;

calculate link metrics for each respective link associated each of the multiple paths identified;

accumulate the respective link metrics for each one of the multiple paths identified to determine respective path metrics of the multiple paths identified; and

utilize the determined path metrics of the respective multiple paths identified to select a preferred communication path.