Granted Patent B2

US 7,876,688 · App. 11/730,329 · Granted Jan 25, 2011

Abstract

Claims (80)

1. A method comprising:

dynamically determining, via a processor, a link connecting two adjacent nodes of a loop in a communication network in accordance with a predefined criterion,

wherein determining the link comprises collecting link capacities of each link of the loop, and calculating the link for breaking the loop using the link capacities collected, the link being optimal with regard to the predefined criterion,

wherein calculating the link comprises:

computing, for each link in the loop, a minimum of an available capacity of a node when the loop is broken at that link,

identifying, for the loop, an overall maximum of the minimum available capacities calculated for each link, and

specifying, as the optimal link for breaking, the link whose minimum available capacity calculated corresponds to the overall maximum capacity identified; and

wherein the method further comprises causing the loop to be reconfigured so that the loop is broken at the determined link.

2. The method according to claim 1 , wherein the dynamic link determination comprises checking a requirement of the dynamic link determination based on at least one of a predefined time period and link capacity changes of links of the loop.

3. The method according to claim 1 , further comprising obtaining a load measure for each node of the loop, wherein the computation of the minimum of an available capacity for each link in the loop involves the load measures obtained for the nodes of the loop.

4. The method according to claim 1 , wherein the dynamic link determination comprises checking a requirement of loop configuration based on the link calculated by applying a hysteresis.

5. The method according to claim 1 , wherein the reconfiguration comprises

acquiring a first path cost value based on current values of path cost parameters of the links of the loop, wherein the first path cost value is a value assuring that the determined link having the first path cost value is broken during loop reconfiguration,

increasing a path cost parameter of the determined link to the first path cost value, and

executing a loop recalculation in accordance with a predefined link state protocol, thus breaking the loop at the determined link.

6. The method according to claim 5 , wherein the predefined link state protocol comprises at least one of a spanning tree protocol and an open shortest path first protocol.

7. The method according to claim 1 , wherein causing the loop to be reconfigured comprises disabling respective interfaces of the two adjacent nodes towards the determined link, thus breaking the loop at the determined link.

8. The method according to claim 1 , wherein dynamically determining the link comprises determining a new determined link that replaces a previous determined link that was previously being broken, and wherein causing the loop to be reconfigured comprises causing the loop to be reconfigured so that the loop is broken at the new determined link and is re-closed at the previous determined link.

9. The method according to claim 8 , wherein causing the loop to be reconfigured comprises:

acquiring a second path cost value based on current values of path cost parameters of the links of the loop, including a first path cost value to which a path cost parameter of the previous determined link is increased, wherein the second path cost value is a value assuring that the new determined link having the second path cost value is broken during loop reconfiguration,

increasing a path cost parameter of the new determined link to the second path cost value,

executing a loop recalculation in accordance with a predefined link state protocol, thus breaking the loop at the new determined link and re-closing the loop at the previous determined link,

decreasing the previously increased path cost parameter of the previous determined link from the first path cost value to a default value,

acquiring a third path cost value based on current values of path cost parameters of the links of the loop, including the default value to which the path cost parameter of the previous determined link is decreased, and

decreasing the path cost parameter of the new determined link from the second path cost value to the third path cost value.

10. The method according to claim 9 , wherein the predefined link state protocol comprises at least one of a spanning tree protocol and an open shortest path first protocol.

11. The method according to claim 8 , wherein causing the loop to be reconfigured comprises causing respective interfaces of the two adjacent nodes towards the new determined link to be disabled and causing previously disabled interfaces of adjacent nodes towards the previous determined link to be enabled, thus breaking the loop at the determined link and re-closing the loop at the previous determined link.

12. The method according to claim 1 , wherein the loop comprises an Ethernet transport technology.

13. The method according to claim 1 , wherein the communication network comprises a radio access network.

14. The method according to claim 1 , wherein the communication network comprises at least one microwave radio link.

15. An apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, direct the apparatus at least to:

dynamically determine a link connecting two adjacent nodes of a loop in a communication network in accordance with a predefined criterion,

wherein being directed to determine the link includes being directed to collect link capacities of each link of the loop, and calculate the link for breaking the loop using the link capacities collected, the link being optimal with regard to the predefined criterion,

wherein being directed to calculate the link includes being directed to:

compute, for each link in the loop, a minimum of an available capacity of a node when the loop is broken at that link,

identify, for the loop, an overall maximum of the minimum available capacities calculated for each link, and

specify, as the optimal link for breaking, the link whose minimum available capacity calculated corresponds to the overall maximum capacity identified; and

wherein the apparatus is further directed to cause the loop to be reconfigured so that the loop is broken at the determined link.

16. The apparatus according to claim 15 , wherein the apparatus directed to determine the link includes being directed to:

determine a predefined time period,

indicate link capacity changes of links of the loop, and

check a requirement of dynamic link determination based on at least one of the predefined time period and the link capacity changes.

17. The apparatus according to claim 15 , wherein the apparatus directed to determine the link includes being directed to:

obtain a load measure for each node of the loop, and

compute the minimum of an available capacity for each link in the loop by involving the load measures obtained for the nodes of the loop.

18. The apparatus according to claim 15 , wherein the apparatus directed to determine the link includes being directed to check a requirement of loop configuration based on the link calculated by applying a hysteresis.

19. The apparatus according to claim 15 , wherein the apparatus directed to determine the link includes being directed to:

acquire a first path cost value based on current values of path cost parameters of the links of the loop, wherein the first path cost value is a value assuring that the determined link having the first path cost value is broken during loop reconfiguration,

increase a path cost parameter of the determined link to the first path cost value, and

execute a loop recalculation in accordance with a predefined link state protocol, thus breaking the loop at the determined link.

20. The apparatus according to claim 15 , wherein the apparatus directed to determine the link includes being directed to cause respective interfaces of the two adjacent nodes towards the determined link to be disabled, thus breaking the loop at the determined link.

21. The apparatus according to claim 15 , wherein the apparatus directed to determine the link includes being directed to determine a new determined link replacing a previous determined link previously being broken, and cause the loop to be reconfigured so that the loop is broken at the new determined link and is re-closed at the previous determined link.

22. The apparatus according to claim 21 , wherein the apparatus directed to determine the link includes being directed to:

acquire a second path cost value based on current values of path cost parameters of the links of the loop, including a first path cost value to which a path cost parameter of the previous determined link is increased, wherein the second path cost value is a value assuring that the new determined link having the second path cost value is broken during loop reconfiguration,

increase a path cost parameter of the new determined link to the second path cost value,

execute a loop recalculation in accordance with a predefined link state protocol, thus breaking the loop at the new determined link and re-closing the loop at the previous determined link,

decrease the previously increased path cost parameter of the previous determined link from the first path cost value to a default value,

acquire a third path cost value based on current values of path cost parameters of the links of the loop, including a default value to which the path cost parameter of the previous determined link is decreased, and

decrease the path cost parameter of the new determined link from the second path cost value to the third path cost value.

23. The apparatus according to claim 21 , wherein the apparatus directed to determine the link includes being directed to cause respective interfaces of the two adjacent nodes towards the new determined link to be disabled and cause previously disabled interfaces of adjacent nodes towards the previous determined link to be enabled, thus breaking the loop at the determined link and re-closing the loop at the previous determined link.

24. The apparatus according to claim 15 , wherein the apparatus comprises an Ethernet interface configured for communication with nodes of the loop via an Ethernet transport technology.

25. The apparatus according to claim 15 , wherein the apparatus acts as a master node of the loop.

26. The apparatus according to claim 15 , wherein the communication network comprises a radio access network.

27. The apparatus according to claim 15 , wherein the apparatus comprises a node of the loop.

28. The apparatus according to claim 15 , wherein the apparatus is integrated into at least one of a stand-alone transmission node, a base station, a base station controller, and a radio network controller.

29. The apparatus according to claim 15 , wherein the apparatus provides an interface to the outside of the loop, via which all upstream traffic passes.

30. An apparatus comprising:

means for dynamically determining a link connecting two adjacent nodes of a loop in a communication network in accordance with a predefined criterion, wherein the means for determining the link comprises means for collecting link capacities of each link of the loop, and means for calculating the link for breaking the loop using the link capacities collected, the link being optimal with regard to the predefined criterion,

wherein the means for calculating the link comprises:

means for computing, for each link in the loop, a minimum of an available capacity of a node when the loop is broken at that link,

means for identifying, for the loop, an overall maximum of the minimum available capacities calculated for each link, and

means for specifying, as the optimal link for breaking, the link whose minimum available capacity calculated corresponds to the overall maximum capacity identified; and

wherein the apparatus further comprises means for causing the loop to be reconfigured so that the loop is broken at the determined link.

31. A non-transitory computer readable medium having a computer program stored thereon, the computer program being configured to control a processor to:

dynamically determine a link connecting two adjacent nodes of a loop in a communication network in accordance with a predefined criterion, wherein the computer program configured to control the processor to determine the link includes being configured to control the processor to collect link capacities of each link of the loop, and calculate the link for breaking the loop using the link capacities collected, the link being optimal with regard to the predefined criterion,

wherein the computer program configured to control the processor to calculate the link includes being configured to control the processor to:

compute, for each link in the loop, a minimum of an available capacity of a node when the loop is broken at the link,

identify, for the loop, an overall maximum of the minimum available capacities calculated for each link, and

specify, as the optimal link for breaking, the link whose minimum available capacity calculated corresponds to the overall maximum capacity identified; and

wherein the computer program is further configured to control the processor to cause the loop to be configured so that the loop is broken at the determined link.

Assignments (9)