Method and apparatus for optimized routing in networks that include free space directional links

• US 20050254430A1
• Filed: 05/13/2004
• Published: 11/17/2005
• Est. Priority Date: 05/13/2004
• Status: Abandoned Application

• Current Assignee: ITT Manufacturing Enterprises, Inc. (ITT, Inc.)
• Original Assignee: ITT Manufacturing Enterprises, Inc. (ITT, Inc.)
• Inventors: Williams, Ralph Maxwell, Clark, Pamela H., Oh, Jaenho A.
• Application Number:
  US10/844,374
• Publication Number:
  US 20050254430A1
• Time in Patent Office: Days
• US Class Current: 370/241
• 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: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 69/14 Multichannel or multilink protocols

Abstract

A method and apparatus is described for optimized routing in networks that include a free space directional link. A free space directional link within a network is monitored at the physical and/or data link layer and a router/routing layer protocol is notified regarding the status of the monitored free space directional link. By monitoring the transmitted signal at the physical and/or data link layer, the present invention avoids reliance upon less frequent control messages to determine free space directional link status, thereby allowing the router/routing layer to be notified more quickly of, and respond more quickly to, changes in free space directional link status.

Claims

1. A free space directional link monitor, comprising:

an analysis module to analyze a characteristic of a signal received via a free space directional link to produce an analysis result; and

a status module to generate a link status update that includes at least one of the analysis result and information related to the analysis result;

wherein the link status update is received by a router or a routing layer.

2. The monitor of claim 1, further comprising:

an information module to store one of a signal characteristic information and a signal characteristic requirement;

wherein the analysis performed by the analysis module includes comparing a received signal characteristic to one of said signal characteristic information and signal characteristic requirement.

3. The monitor of claim 2, wherein the information module further includes:

a threshold module to store a signal characteristic threshold value.

4. The monitor of claim 2, wherein the information module further includes:

a range module to store a signal characteristic range.

5. The monitor of claim 1, wherein the status module is configured to generate a link status update that includes an indication of whether the link is one of operational and non-operational.

6. The monitor of claim 1, wherein the status module is configured to generate a link status update that includes an indicator of whether a change in link status has occurred.

7. The monitor of claim 1, wherein the analysis module further comprises:

a physical-layer module to analyze a physical characteristic of the signal received via the free space directional link to produce an analysis result.

8. The monitor of claim 7, wherein the physical signal characteristic is a signal-to-noise ratio.

9. The monitor of claim 7, wherein the physical signal characteristic is a received signal power level.

10. The monitor of claim 9, wherein the received signal power level is one of an instantaneous power level and an average power level.

11. The monitor of claim 1, wherein the analysis module further comprises:

a data-link-layer module to analyze a data link layer characteristic of the signal received via the free space directional link to produce an analysis result.

12. The monitor of claim 11, wherein the data link layer characteristic is one of an error rate and a data transfer rate.

13. A router for routing a message within a network that supports a free space directional link, the router comprising:

a control module to receive and process a status update containing information related to a status of the free space directional link; and

a routing module to route the message based at least in part upon information contained within the status update;

wherein the status update is generated by a free space directional link monitor based upon an analysis of a characteristic of a signal received via the free space directional link.

14. The router of claim 13, wherein the control module is configured to receive a status update indicating one of link failure and link restoration.

15. The router of claim 13, wherein the control module is configured to receive a status update indicating one of a link status and a change in link status.

16. The router of claim 13, further comprising:

an information module to store one of network connectivity and routing information;

wherein the control module updates information stored in the information module in response to receipt of a status update.

17. The router of claim 13, wherein the routing module further comprises:

a re-routing module to re-route a message across one of an alternate route and an optimal route in response to receipt of a change in the status of a free space directional link.

18. A method for monitoring a free space directional link, the method comprising:

(a) analyzing a characteristic of a signal received via the free space directional link to produce an analysis result; and

(b) generating a link status update that includes at least one of the analysis result and information related to the analysis result;

wherein the link status update is received by a router or a routing layer

19. The method of claim 18, further comprising:

(c) storing one of a signal characteristic information and a signal characteristic requirement;

wherein (a) further includes comparing a received signal characteristic to one of said stored signal characteristic information and said stored signal characteristic requirement.

20. The method of claim 19, wherein (c) further includes:

(c.1) storing a signal characteristic threshold value.

21. The method of claim 19, wherein (c) further includes:

(c.1) storing a signal characteristic range.

22. The method of claim 18, wherein (b) further includes:

(b.1) generating a link status update that includes an indication of whether the link is one of operational and non-operational.

23. The method of claim 18, wherein (b) further includes:

(b.1) generating a link status update that includes an indicator of whether a change in link status has occurred.

24. The method of claim 18, wherein (a) further comprises:

(a.1) analyzing a physical characteristic of the signal received via the free space directional link to produce an analysis result.

25. The method of claim 24, wherein (a.1) further includes:

analyzing the physical signal to determine a signal-to-noise ratio.

26. The method of claim 24, wherein (a.1) further includes:

analyzing the physical signal to determine a received signal power level.

27. The method of claim 26, wherein (a.1) further includes:

analyzing the physical signal to determine one of an instantaneous signal power level and an average signal power level.

28. The method of claim 18, wherein (a) further includes:

(a.1) analyzing a data link layer characteristic of the signal received via the free space directional link to produce an analysis result.

29. The method of claim 28, wherein (a.1) further includes:

analyzing one of a data transfer rate and a data error rate.

30. A method for routing a message within a network that supports a free space directional link, the method comprising:

(a) receiving and processing a status update containing information related to a status of a free space directional link; and

(b) routing the message based at least in part upon information contained within the status update;

wherein the status update is based upon an analysis of a characteristic of a signal received via the free space directional link.

31. The method of claim 30, wherein (a) further includes:

receiving a status update indicating one of link failure and link restoration.

32. The method of claim 30, wherein (a) further includes:

receiving a status update indicating one of a link status and a change in link status.

33. The method of claim 30, further comprising:

(c) storing one of network connectivity and routing information;

wherein (a) further includes;

(a.1) storing the information in response to receipt of a status update.

34. The method of claim 30, wherein (b) further comprises:

(b.1) re-routing a message across one of an alternate route and an optimal route in response to receiving a change in the status of a free space directional link.

35. A program product apparatus having a computer readable medium with computer program logic recorded thereon for monitoring a free space directional link, said program product apparatus comprising:

an analysis module to analyze a characteristic of a signal received via a free space directional link to produce an analysis result; and

a status module to generate a link status update that includes at least one of the analysis result and information related to the analysis result;

wherein the link status update is received by a router or a routing layer

36. The program product of claim 35, further comprising:

an information module to store one of a signal characteristic information and a signal characteristic requirement;

wherein the analysis performed by the analysis module includes comparing a received signal characteristic to one of said signal characteristic information and signal characteristic requirement.

37. The program product of claim 35, wherein the status module is configured to generate a link status update that includes an indication of whether the link is one of operational and non-operational.

38. A program product apparatus having a computer readable medium with computer program logic recorded thereon for routing a message within a network that supports a free space directional link, said program product apparatus comprising:

a control module to receive and process a status update containing information related to a status of the free space directional link;

a routing module to route the message based at least in part upon information contained within the status update;

wherein the status update is generated by a free space directional link monitor based upon an analysis of a characteristic of a signal received via the free space directional link.

39. The program product of claim 38, further comprising:

an information module to store one of network connectivity and routing information;

wherein the control module updates information stored in the information module in response to receipt of a status update.

40. The program product of claim 38, wherein the routing module further comprises:

a re-routing module to re-route a message across one of an alternate route and an optimal route in response to receipt of a change in the status of a free space directional link.