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 of engineering a connection between two terminals of a dynamically reconfigurable photonic network comprising:
setting-up a path whenever an operational parameter of said path is above a test threshold;
operating said path in monitoring mode whenever an operational parameter is above a maintenance threshold; and
servicing said path whenever said operational parameter is under said maintenance threshold.
2. A method as claimed in claim 1 , wherein the step of setting-up comprises:
selecting a physical route for said path based on network topology information, resources specifications and path selection rules;
assigning ‘n’ wavelength to said path based on wavelength selection rules and the number ‘m’ of regenerators connected in said path;
lighting-up said path and measuring said operational parameter;
comparing said operational parameter with said test threshold; and
transiting the state of said path form set-up to established if said operational parameter is above said test threshold.
3. A method as claimed in claim 2 , further comprising switching a wavelength-converter/regenerator device into said path whenever said operational parameter is under said test threshold.
4. A method as claimed in claim 2 , further comprising selecting a new physical route and switching said path along said new route whenever said operational parameter is under said test threshold.
5. A method as claimed in claim 1 , wherein the step of operating said path in a monitoring mode comprises:
continuously measuring said operational parameter,
continuously comparing said operational parameter with a maintenance threshold; and
switching a wavelength-converter/regenerator device into said path whenever said operational parameter is under said maintenance threshold.
6. A method as claimed in claim 5 , further comprising transitioning from said operational state to a tearing down state if said operational parameter is under said margin tolerance after said device has been switched into said path.
7. A method as claimed in claim 1 , wherein the step of operating said path in a monitoring mode comprises:
continuously measuring said operational parameter,
continuously comparing said operational parameter with a maintenance threshold; and
selecting a new physical route and switching said path along said new route whenever said operational parameter is under said maintenance threshold.
8. A method of engineering a connection over a WDM photonic network with a plurality of flexibility sites, comprising:
selecting a data communication path for said connection based on network topology information, resources specifications and class of service constraints;
turning on a source transmitter, a destination receiver and all transmitters and receivers at all flexibility sites along said path;
increasing gradually the power level of said transmitters while measuring an error quantifier at said destination receiver; and
maintaining the power at said transmitters at a first level corresponding to a preset error quantifier.
9. A method as claimed in claim 8 , further comprising:
operating said path in a monitoring mode by continuously measuring the error quantifier at said destination receiver;
increasing the power level of said transmitter from said first level while measuring the error quantifier at said destination receiver; and
maintaining the power level for said connection at a second level where said error quantifier is below said preset error quantifier.