Method for engineering connections in a dynamically reconfigurable photonic switched network
View Patent ↗A method for engineering of a connection in a WDM photonic network with a plurality of flexibility sites connected by links comprises calculating a physical end-to-end route between a source node and a destination node and setting-up a communication path along this end-to-end route. An operational parameter of the communication path is continuously tested and compared with a test threshold. The path is declared established whenever the operational parameter is above the margin tolerance. The established path is continuously monitored by comparing the operational parameter with a maintenance threshold. A regenerator is switched into the path whenever the operational parameter is under the respective threshold, or another path is assigned to the respective connection. An adaptive channel power turn-on procedure provides for increasing gradually the power level of the transmitters in the path while measuring an error quantifier at the destination receiver until a preset error quantifier value is reached. As the connection ages, the power is increased so as to maintain the error quantifier at, or under the preset value. The path operation is controlled using a plurality of optical power/gain control loops, each for monitoring and controlling a group of optical devices, according to a set of loop rules.
1. A method for engineering of a connection in a WDM photonic network with a plurality of flexibility sites connected by links, comprising:
(a) calculating a physical end-to-end route between a source node and a destination node;
(b) setting-up a data communication path along said end-to-end route;
(c) detecting an end-to-end operational parameter of said data communication path at a power level that is between a maximum useful power level and a provisional power level; and
(d) comparing said operational parameter with a margin tolerance and declaring said data communication path as established, whenever said operational parameter is above said margin tolerance.
2. A method as claimed in claim 1 , further comprising (e) continuously monitoring said established data communication path by measuring and comparing said operational parameter with a churn threshold.
3. A method as claimed in claim 2 , wherein said margin tolerance and said churn threshold are each a negotiated value based on the cost of said data communication path and potential network churn.
4. A method as claimed in claim 2 , wherein said churn threshold is preset by averaging a plurality of values measured for said operational parameter during fast and slow variances in operation of said network.
5. A method as claimed in claim 2 , wherein said churn threshold is determined by integrating a plurality of values measured for said operational parameter over a time interval.
6. A method as claimed in claim 2 , further comprising:
abandoning said data communication path if said operational parameter cannot be improved above any of said margin and said churn threshold;
calculating a new end-to-end route, and
performing steps (b) to (d).
7. A method as claimed in claim 2 , wherein said operational parameter is any of the end-to-end Q value and the BER of said data communication path.
8. A method as claimed in claim 1 , wherein said margin tolerance is determined based on a data communication path start of life margin value.
9. A method as claimed in claim 8 , wherein said start of life margin value is a negotiated value based on potential network performance degradation during the life of said data communication path.
10. A method as claimed in claim 1 , further comprising, whenever said operational parameter is under said margin tolerance:
detecting a free regenerator at a flexibility site along said end-to-end route;
improving said operational parameter by inserting said free regenerator in said data communication path;
marking said free regenerator as allocated to said data communication path; and
performing steps (b) to (d).
11. A method for dynamic engineering of a data communication path in a WDM photonic network with a plurality of flexibility sites connected by links, comprising:
(a) calculating a physical end-to-end route for connecting a source node and a destination node over said WDM network;
(b) setting-up data communication path along said end-to-end route;
(c) detecting an end-to-end operational parameter of said data communication path at a power level that is between a maximum useful power level and a provisional power level; and
(d) comparing said operational parameter with a test threshold and declaring said data communication path as established, whenever said operational parameter is above said test threshold.
12. A method as claimed in claim 11 , further comprising (e) continuously monitoring said established data communication path by measuring and comparing said operational parameter with a maintenance threshold.
13. A method as claimed in claim 12 , wherein said performance parameter is the quality factor Q of said data communication path and said test threshold and said maintenance threshold are selected.
14. A method as claimed in claim 12 , further comprising, whenever said operational parameter is under any of said test threshold and said maintenance threshold, selecting a new end-to-end physical route for said data communication path and repeating steps (b) to (d).
15. A photonic network for routing a data communication path between a source node and a destination node along a route passing through an intermediate node, comprising:
a pool of wavelength-converter/regenerators connected at said intermediate node;
a line control system for collecting end-to-end performance information on said data communication path; and
a network management system for assigning a wavelength-converter/regenerator from said pool to said data communication path and switching said data communication path through said wavelength-converter/regenerator, whenever the performance of said data communication path is outside an operation range and adjustment of a channel power level to return the performance to within a satisfactory performance range is not successful.
16. A system for engineering a connection in a WDM photonic network with a plurality of flexibility sites connected by links, operable to:
(a) calculate a physical end-to-end route between a source node and a destination node;
(b) set-up a data communication path along said end-to-end route;
(c) detect an end-to-end operational parameter of said data communication path at a power level that is between a maximum useful power level and a provisional power level; and
(d) compare said operational parameter with a margin tolerance and declaring said data communication path as established, whenever said operational parameter is above said margin tolerance.
17. A system as claimed in claim 16 , further operable to (e) continuously monitor said established data communication path by measuring and comparing said operational parameter with a churn threshold.
18. A system as claimed in claim 17 , wherein said margin tolerance and said churn threshold are each a negotiated value based on the cost of said data communication path and potential network churn.
19. A system as claimed in claim 17 , wherein said churn threshold is preset by averaging a plurality of values measured for said operational parameter during fast and slow variances in operation of said network.
20. A system as claimed in claim 17 , wherein said churn threshold is determined by integrating a plurality of values measured for said operational parameter over a time interval.
21. A system as claimed in claim 17 , further operable to:
abandon said data communication path if said operational parameter cannot be improved above any of said margin and said churn threshold;
calculate a new end-to-end route, and
perform steps (b) to (d).
22. A system as claimed in claim 17 , wherein said operational parameter is any of the end-to-end Q value and the BER of said data communication path.
23. A system as claimed in claim 16 , wherein said margin tolerance is determined based on a data communication path start of life margin value.
24. A system as claimed in claim 23 , wherein said start of life margin value is a negotiated value based on potential network performance degradation during the life of said data communication path.
25. A system as claimed in claim 16 , further operable to, whenever said operational parameter is under said margin tolerance:
detect a free regenerator at a flexibility site along said end-to-end route;
improve said operational parameter by inserting said free regenerator in said data communication path;
mark said free regenerator as allocated to said data communication path; and
perform steps (b) to (d).
26. A system for dynamic engineering of a data communication path in a WDM photonic network with a plurality of flexibility sites connected by links, operable to:
(a) calculate a physical end-to-end route for connecting a source node and a destination node over said WDM network;
(b) set-up data communication path along said end-to-end route;
(c) detect an end-to-end operational parameter of said data communication path at a power level that is between a maximum useful power level and a provisional power level; and
(d) compare said operational parameter with a test threshold and declaring said data communication path as established, whenever said operational parameter is above said test threshold.
27. A system as claimed in claim 26 , further operable to, (e) continuously monitor said established data communication path by measuring and comparing said operational parameter with a maintenance threshold.
28. A system as claimed in claim 27 , wherein said performance parameter is the quality factor Q of said data communication path and said test threshold and said maintenance threshold are selected.
29. A system as claimed in claim 27 , further operable to, whenever said operational parameter is under any of said test threshold and said maintenance threshold, select a new end-to-end physical route for said data communication path and repeat steps (b) to (d).