Performance Analysis of WSS-Based ROADM With Shared-Per-Group Tunable Wavelength Converters

We propose a flexible shared-per-group (SPG) architecture for wavelength selective switch (WSS)-based reconfigurable optical add/drop multiplexers (ROADMs) to support dynamic datacenter wavelength-convertible networks. The key components of this module are grouping installed tunable wavelength converter (TWCs) and tunable filter (TFs). Using the SPG architecture, the demands that collide among different outputs will be all-optically resolved by a combination of TWCs and TFs without installing any switch matrix devices. Thus, the proposed SPG architecture may produce better blocking performance than the conventional shared-per-link, shared-per-wavelength architectures consuming lower costs. Meanwhile, analytical model is proposed to evaluate the SPG blocking probability by means of the self-constrained iteration method. Accurate results showed that SPG architecture requires the number of groups larger than the number of ports to produce the optimal blocking performance, saving 50% of TWCs under high and moderate traffic loads.