A meta-heuristic approach for monitoring trail assignment in WDM optical networks

Optical network survivability relies on automatic fiber cut detection. Cost-effective and unambiguous fiber cut localization remains an open problem for transparent optical networks. In this paper, we focus on out-of-band monitoring techniques based on the concept of monitoring trail (m-trail) recently proposed in the literature [1]. An m-trail-based solution guarantees the exact localization of any single link failure. Two approaches have been proposed for the design of m-trails: an exact Integer Linear Program formulation and a heuristic approach based on the Random Code Assignment-Random Code Swapping (RCA-RCS) concept. Numerical applications underline two drawbacks of these approaches. The former is not scalable in terms of computational complexity. The latter provides monitoring solutions that strongly depend on the choice of the initial conditions. Thus, the final solutions can be relatively far from the optimal in the case of large networks. We propose an original meta-heuristic approach called MEMOTA that overcomes these drawbacks. Numerical results show that MEMOTA provides near optimal solutions with much shorter computing delays than the ILP formulation. In addition, unlike RCA-RCS, MEMOTA is less sensitive to initial conditions.