System and method for using per-packet receive signal strength indication and transmit power levels to compute path loss for a link for use in layer II routing in a wireless communication network

• US 20060159038A1
• Filed: 02/23/2006
• Published: 07/20/2006
• Est. Priority Date: 03/06/2002
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Stanforth, Peter J., Hasty, William Vann Jr.
• Granted Patent: US 7,672,246 B2
• Time in Patent Office: Days
• US Class Current: 370/315
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04W 40/00 Communication routing or communication path finding
• CPC Class Codes: H04W 40/08 based on transmission power
• CPC Class Codes: H04W 40/12 based on transmission quality or channel quality
• CPC Class Codes: H04W 40/248 Connectivity information update
• CPC Class Codes: H04W 40/28 for reactive routing
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A system and method for evaluating at least one communication link between a transmitting node (102, 106, 107) and a receiving node in a communications network (100), such as a wireless ad-hoc communications network (100) in accordance with the 802.11 standard. The system and method perform the operation of assigning respective link quality values to the respective communication links based on a transmit power level (TPL) value at which the respective data packets were transmitted by the transmitting node (102, 106, 107) over the respective links, a received sensitivity (RS) value of the receiving node (102, 106, 107) receiving the data packets, and a receive signal strength indication (RSSI) value provided by the network (100) for each respective link. The system and method can examine a content of a data packet being sent between the two nodes (102, 106, 107) to determine the TPL, and can receive the RSSI value from a physical layer of the communications network (100). Accordingly, the system and method can determine which link that additional data packets are to be sent by the transmitting node (102, 106, 107) to the receiving node (102, 106, 107) via the communication link based on the link quality values. Specifically, the link having the highest link quality value is selected.

Claims

1. A system, adapted for use in a communications network, for evaluating at least one communication link between a transmitting node and a receiving node in the communications network, the system comprising:

a processor for assigning a link quality value to said communication link based on a transmit power level (TPL) value at which said data packet was transmitted by said transmitting node, a received sensitivity (RS) value of said receiving node receiving said data packet, and a receive signal strength indication (RSSI) value provided by said network.

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

a packet analyzer for examining a content of a data packet being sent between said two nodes to determine said TPL.

3. A system as claimed in claim 1, wherein:

said processor receives said RSSI value from a physical layer of said communications network.

4. A system as claimed in claim 1, wherein:

said processor determines whether additional data packets are to be sent by said transmitting node to said receiving node via said communication link based on said link quality value.

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

said network includes an ad-hoc wireless communications network; and

said processor assigns said link quality value to said communication link between said transmitting and receiving nodes which are each wireless nodes in said ad-hoc wireless communications network.

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

said network includes an 802.11-type network; and

said processor assigns said link quality value to said communication link between said transmitting and receiving nodes which are each wireless 802.11-type nodes in said 802.11-type network.

7. A system as claimed in claim 1, wherein:

said processor maintains an average of the link quality value.

8. A system as claimed in claim 1, wherein:

said processor assigns a respective said link quality value to each respective one of said communication links between said transmitting and receiving nodes.

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

said processor selects one of said communication links as a selected route via which additional data packets are to be sent by said transmitting node to said receiving node via said communication link based on said link quality value.

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

said processor selects as said selected route one of said communications links having the highest link quality value.

11. A system as claimed in claim 1, wherein:

said processor assigns said link quality value on a per packet basis.

12. A method for evaluating at least one communication link between a transmitting node and a receiving node in a communications network, the method comprising:

assigning a link quality value to said communication link based on a transmit power level (TPL) value at which said data packet was transmitted by said transmitting node, a received sensitivity (RS) value of said receiving node receiving said data packet, and a receive signal strength indication (RSSI) value provided by said network.

13. A method as claimed in claim 12, further comprising:

examining a content of a data packet being sent between said two nodes to determine said TPL.

14. A method as claimed in claim 12, further comprising:

receiving said RSSI value from a physical layer of said communications network.

15. A method as claimed in claim 12, further comprising:

determining whether additional data packets are to be sent by said transmitting node to said receiving node via said communication link based on said link quality value.

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

said network includes an ad-hoc wireless communications network; and

said assigning assigns said link quality value to said communication link between said transmitting and receiving nodes which are each wireless nodes in said ad-hoc wireless communications network.

17. A method as claimed in claim 12, wherein:

said network includes an 802.11-type network; and

said assigning assigns said link quality value to said communication link between said transmitting and receiving nodes which are each wireless 802.11-type nodes in said 802.11-type network.

18. A method as claimed in claim 12, further comprising:

maintaining an average of the link quality value.

19. A method as claimed in claim 12, wherein:

said assigning assigns a respective said link quality value to each respective one of said communication links between said transmitting and receiving nodes.

20. A method as claimed in claim 19, further comprising:

selecting one of said communication links as a selected route via which additional data packets are to be sent by said transmitting node to said receiving node via said communication link based on said link quality value.

21. A method as claimed in claim 20, wherein:

said selecting selects as said selected route one of said communications links having the highest link quality value.

22. A method as claimed in claim 12, wherein:

said assigning assigns said link quality value on a per packet basis.