Optical Selective System (WSS ROADM)

The Optical Selective System is a WSS-based ROADM building block that enables dynamic wavelength routing and software-defined add/drop in metro and backbone DWDM networks. Using a liquid-crystal-on-silicon (LCoS) or MEMS Wavelength Selective Switch, it steers individual ITU channels (or sub-carriers in flex-grid) to any degree or add/drop port, while integrated VOAs perform per-channel power leveling and hitless reconfiguration.
Deployed with HYD MUX/DEMUX, EDFA/Raman, OCM/OTDR, and OLP modules, the system delivers CDC (colorless/directionless/contentionless) architectures that simplify growth, reduce truck rolls, and maintain stable OSNR during channel adds, moves, or protection events. Managed via NMS/Web/CLI/SNMP—with Netconf/YANG for automation—the module supports real-time telemetry, alarms, and topology discovery for multi-vendor environments.

• ROADM functions: colorless/directionless add/drop; M×N wavelength switching

• Grid options: fixed 50/75/100 GHz and flex-grid (e.g., 12.5 GHz granularity)

• WSS variants: 1×N (e.g., 1×9/1×20) degree, broadcast-and-select add/drop

• Equalization: per-channel VOA for power leveling; hitless reconfiguration

• Monitoring: OCM/OLPM integration; OTDR test access; event & performance logs

• Protection: interoperates with OLP, optical bypass; fast restore under LOS/degrade

• Optics: C-band operation; low IL/PDL/PMD; high isolation & return loss

• Form factors: plug-in card for HYD 1U/2U/5U chassis or 1U stand-alone

• Management: NMS/Web/CLI/SNMP; Netconf/YANG APIs; dry-contact relays