Abstract | We design and implement various algorithms for
solving the static RWA problem with the objective of minimizing
the maximum number of requested wavelengths based on LP
relaxation formulations. We present a link formulation, a path
formulation and a heuristic that breaks the problem in the two
constituent subproblems and solves them individually and
sequentially. The flow cost functions that are used in these
formulations result in providing integer optimal solutions despite
the absence of integrality constraints for a large subset of RWA
input instances, while also minimizing the total number of used
wavelengths. We present a random perturbation technique that is
shown to increase the number of instances for which we find
integer solutions, and we also present appropriate iterative fixing
and rounding methods to be used when the algorithms do not yield
integer solutions. We comment on the number of variables and
constraints these formulations require and perform extensive
simulations to compare their performance to that of a typical minmax
congestion formulation. |