Method and system for increasing transponder sharing for mesh restoration in a communication network

1. A method comprising:

for each particular working demand in a communication network, calculating a dedicated backup path for a working path of the particular working demand such that each particular backup path does not include links present in the working path; and

for each particular working demand:

assigning to the backup path a wavelength associated with the particular working demand; and

assigning to the backup path a transponder at each of the source and destination of the backup path associated with the wavelength;

such that the backup path for at least one particular working demand is assigned a transponder that is also assigned to the backup path for at least one other particular working demand.

2. A method according to claim 1 , wherein assigning to the backup path the wavelength and the transponders at each of the source and destination of the backup path comprises:

for each link in the communication network, simulating a link failure;

for each particular simulated link failure, determining all working demands affected by the particular simulated link failure; and

for each particular affected working demand:

determining if one or more available wavelengths exist, each available wavelength comprising a wavelength that is not yet assigned to a conflict demand of the particular affected working demand, wherein a conflict demand comprises:

a working demand whose working path shares a link with the working path of the particular affected working demand;

a working demand whose backup path shares a link with the backup path of the particular affected working demand; and

if one or more available wavelengths exist, assigning the backup path of the particular working demand to one of the one or more available wavelengths.

3. A method according to claim 2 , further comprising determining if one of the one or more available wavelengths is associated with a transponder of at least one of the source and destination of the backup path, wherein the transponder is:

assigned to a backup path of a working demand that does not share a link with the working path of the particular affected working demand; and

not already assigned to a conflict demand.

4. A method according to claim 1 , wherein the communication network is an optical communication network.

5. A method according to claim 4 , wherein the communication network is a colored and directional reconfigurable add/drop multiplexer network.

6. A method according to claim 1 , where the backup path for the at least one particular working demand is assigned a transponder that is also assigned to the backup path for the at least one other particular working demand if the at least one particular working demand and the at least one other particular working demand are not conflict demands of one another.

7. A network element comprising:

a processor; and

a resource allocation module communicatively coupled to the processor and configured to, either individually or in concert with one or more other resource allocation modules integral to one or more other network elements:

for each particular working demand in a communication network including the network element, calculate a dedicated backup path for a working path of the particular working demand such that each particular backup path does not include links present in the working path; and

for each particular working demand:

assign to the backup path a wavelength associated with the particular working demand; and

assign to the backup path a transponder at each of the source and destination of the backup path associated with the wavelength;

such that the backup path for at least one particular working demand is assigned a transponder that is also assigned to the backup path for at least one other particular working demand.

8. A network element according to claim 7 , the resource allocation module further configured to, either individually or in concert with one or more other resource allocation modules integral to one or more other network elements, assign to the backup path the wavelength and the transponders at each of the source and destination of the backup path by:

for each link in the communication network, simulating a link failure;

for each particular simulated link failure, determining all working demands affected by the particular simulated link failure; and

for each particular affected working demand:

determining if one or more available wavelengths exist, each available wavelength comprising a wavelength that is not yet assigned to a conflict demand of the particular affected working demand, wherein a conflict demand comprises:

a working demand whose working path shares a link with the working path of the particular affected working demand;

a working demand whose backup path shares a link with the backup path of the particular affected working demand; and

if one or more available wavelengths exist, assigning the backup path of the particular working demand to one of the one or more available wavelengths.

9. A network element according to claim 8 , resource allocation module further configured to, either individually or in concert with one or more other resource allocation modules integral to one or more other network elements, determine if one of the one or more available wavelengths is associated with a transponder of at least one of the source and destination of the backup path, wherein the transponder is:

assigned to a backup path of a working demand that does not share a link with the working path of the particular affected working demand; and

not already assigned to a conflict demand.

10. A network element according to claim 7 , wherein the communication network is an optical communication network.

11. A network element according to claim 10 , wherein the communication network is a colored and directional reconfigurable add/drop multiplexer network.

12. A network element according to claim 7 , where the backup path for the at least one particular working demand is assigned a transponder that is also assigned to the backup path for the at least one other particular working demand if the at least one particular working demand and the at least one other particular working demand are not conflict demands of one another.

13. An article of manufacture, comprising:

a non-transitory computer readable medium;

computer-executable instructions carried on the computer readable medium, the instructions readable by a processor, the instructions, when read and executed, for causing the processor to:

for each particular working demand in a communication network, calculate a dedicated backup path for a working path of the particular working demand such that each particular backup path does not include links present in the working path; and

for each particular working demand:

assign to the backup path a wavelength associated with the particular working demand; and

assign to the backup path a transponder at each of the source and destination of the backup path associated with the wavelength;

such that the backup path for at least one particular working demand is assigned a transponder that is also assigned to the backup path for at least one other particular working demand.

14. An article of manufacture according to claim 13 , wherein, in order to assign to the backup path the wavelength and the transponders at each of the source and destination of the backup path, the processor further caused to:

for each link in the communication network, simulate a link failure;

for each particular simulated link failure, determine all working demands affected by the particular simulated link failure; and

for each particular affected working demand:

determine if one or more available wavelengths exist, each available wavelength comprising a wavelength that is not yet assigned to a conflict demand of the particular affected working demand, wherein a conflict demand comprises:

a working demand whose working path shares a link with the working path of the particular affected working demand;

a working demand whose backup path shares a link with the backup path of the particular affected working demand; and

if one or more available wavelengths exist, assign the backup path of the particular working demand to one of the one or more available wavelengths.

15. An article of manufacture according to claim 14 , the processor further caused to determine if one of the one or more available wavelengths is associated with a transponder of at least one of the source and destination of the backup path, wherein the transponder is:

assigned to a backup path of a working demand that does not share a link with the working path of the particular affected working demand; and

not already assigned to a conflict demand.

16. An article of manufacture according to claim 13 , wherein the communication network is an optical communication network.

17. An article of manufacture according to claim 16 , wherein the communication network is a colored and directional reconfigurable add/drop multiplexer network.

18. An article of manufacture according to claim 13 , where the backup path for the at least one particular working demand is assigned a transponder that is also assigned to the backup path for the at least one other particular working demand if the at least one particular working demand and the at least one other particular working demand are not conflict demands of one another.