Experimental Evaluation of RSA Algorithms for SDN-Programmable VCSEL-Based S-BVT in High-Capacity and Cost-Efficient Optical Metro Networks

Abstract

Future metro networks need to increase the transport capacity and improve the cost-and power-efficiency. These challenges are tackled by the EU-H2020 PASSION project exploiting dense photonic integration and cost-efficient optical technologies. Specifically, PASSION investigates a) modular sliceable bandwidth variable transceivers (S-BVTs) built upòn a set of both vertical cavity surface emitting lasers (VCSEL) and Coherent Receivers (CO-Rx); and b) hierarchical switching nodes in a flexigrid network. An SDN controller handles the network programmability where a key functionality is the path computation and resource selection to fulfil the connection requirements. This is conducted by the Routing and Spectrum Assignment (RSA) algorithms. The considered S-BVT transmitter imposes that each S-BVT VCSEL reaches up to 50 Gb/s. Thus, connections requesting higher bandwidth (e.g., 200 Gb/s) are accommodated over several optical flows. In this context, two RSA algorithms called co-routed (RSA-CR) and inversed multiplexed (RSA-IM) optical flows are proposed and compared. The RSA-CR enforces that all the connection's optical flows are routed over the same spatial path; the RSA-IM relaxes this allowing the optical flows being set up over different spatial routes. The experimental evaluation, made upon dynamic traffic, aims at comparing both RSA algorithms performance according to the blocked bandwidth ratio, the average used of S-BVT devices, and the average setup time.