TRANSPONDER FOR WDM RING NETWORK

摘要

For a WDM ring network, a node has an optical add drop part and a transponder having a wavelength tunable transmitter for sending a selectable one of the wavelengths in a selectable direction around the ring to a destination node. There is a controller configured to select the wavelength to be sent by the wavelength tunable transmitter and to change the direction of sending around the ring, in response to a detection of a fault in sending in one of the directions. By making the transponder colourless and yet able to select direction, a simple protection switching capability can be added to an existing low cost WDM ring network having passive optical filters. This can be achieved without the need for a reconfigurable optical add drop multiplexer and associated control plane.

主权项

1. A node for a WDM ring network, the node comprising:
an optical add drop part; and a transponder, wherein: the optical add drop part has optical add filters and optical drop filters for respectively adding and dropping selected wavelengths in clockwise and anti-clockwise directions around the ring; and the transponder has a wavelength tunable transmitter having first and second output optical paths coupled to respective optical add filters for clockwise and anti-clockwise directions, of the optical add drop part, for sending a selectable one of the wavelengths in a selectable direction around the ring to a destination node, and the transponder also has: a controller for the wavelength tunable transmitter configured to select the wavelength to be sent by the wavelength tunable transmitter and to change the direction of sending around the ring, in response to a detection of a fault in sending in one of the directions.