Efficient amplifier placement method for self-healing metropolitan WDM rings

In this paper, we expand our previous work on amplifier placement for single-fiber WDM rings to self healing WDM rings (SHWRs). A new method to optimally place amplifiers in unidirectional and bidirectional SHWRs is presented. The method iteratively solves for the optimal number of amplifiers in a SHWR under a normal and different link failure conditions. The solution ensures that the ring is operational under a normal condition or any single link failure.