What is ROADM? _Definition & Classification

What is ROADM?

ROADM (Reconfigurable Optical Add-Drop Multiplexer) is a core component of optical communication network, which is used to dynamically manage wavelength (λ) resources in optical fibre. Compared with the traditional fixed OADM, ROADM can adjust the wavelength up/down and routing in real time through remote control by software to achieve elastic allocation of network resources.

Core features:

- Wavelength flexible scheduling: no need for manual fibre hopping, remote increase or decrease of service wavelength.

- Network self-healing: automatically switch routing when fibre is interrupted to ensure service continuity.

- Spectrum Optimization: Supports Flexi-Grid to improve fibre utilization by more than 30%.

Technical classification of ROADM

1. Classification by hardware architecture

WSS: Wavelength Selector Switch

PLC: Planar Light Waveguide

2. Classification by Functional Class

- Directionless: Wavelengths can be routed up and down in any direction, eliminating physical port limitations.

- Colorless: The same port supports any wavelength, reducing hardware redundancy.

- Contentionless: The same wavelength can be reused in different directions to avoid resource conflicts.

- Flex Grid: Break the fixed 50GHz interval and allocate 12.5GHz~200GHz spectrum on demand.

Advanced form: CDC-F ROADM (Direction/Wavelength/Competition-independent + Flex Grid), representing the highest flexibility of optical networks.

Currently Sintai Communication offers 9-degree WSS-based ROADM boards (Directionless) on the DCI platform; if interested, please feel free to contact us!