Experimental Evaluation of an On-line RSA Algorithm for SDN-Controlled Optical Metro Networks with VCSEL-based S-BVTs

Upcoming metro networks are required to transport huge and highly dynamic data traffic whilst resulting cost and power efficient. Thus, novel metro network architectures are being investigated to increase the transport capacity (e.g., leveraging dense photonic integrated technologies), and provide effective SDN-based network programmability. The EU-H2020 PASSION project targets such a metro network design exploiting: i) programmable, modular, cost-efficient and low-power sliceable bandwidth variable transceivers (S-BVTs) formed by a pool of vertical cavity surface emitting lasers (VCSEL) and Coherent Receivers (CO-Rx); ii) hierarchical switching nodes in a flexi-grid network to attain all-optical transport and aggregation. The SDN-based control functions considers the features of the adopted PASSION transport layer. First, we detail the defined interfaces (APIs) for the automatic transport network programmability. Such (RESTful-based) interfaces are validated within the ADRENALINE testbed. Next, upon dynamic connection requests with heterogenous data rate demands, an on-line Routing and Spectrum Assignment (RSA) algorithm based on a modified K shortest path (K-SP) is proposed. To accommodate a connection request, a set of optical flows having their own S-BVT VCSEL and CO-Rx devices at the endpoints and path’s frequency slots are selected and configured. Each optical flow is subject to the spectral continuity and contiguity constraints. The performance of the RSA algorithm for several traffic loads is experimentally evaluated through different figures of merit (e.g., blocked bandwidth ratio, average used of S-BVT devices, etc.) and diverse RSA’s K-SP settings.