A pre-split multi-flow RMSA algorithm in elastic optical networks

摘要

Elastic optical networking is a promising technology for the next generation optical networks, due to its flexibility of spectrum provisioning. Routing, modulation and spectrum assignment (RMSA) problem is one of the key issues in Elastic optical networks. In the problem, constraints of spectrum continuity and spectrum contiguity must be met, which limits the use of spectrum resources. Multi-flow measure, which splits a connection request into multiple flows if the connection request cannot be served as a whole, can relax the spectrum contiguity constraint. The existing multi-flow RMSA algorithms are post-split. In this paper, we propose a pre-split multi-flow RMSA algorithm, in which three innovative measures are adopted, namely partitioning frequency slices into standard blocks, pre-splitting connection requests into flows exactly using the standard blocks, and searching for available standard blocks for the flows with a proposed modified-most-used rule. The measures can make both the occupied and idle frequency slices aligned, so they are expected to lower the blocking probability of connection requests. Simulation results show that the proposed algorithm can get a better performance in term of blocking probability, comparing with three benchmarks.