First Mile Access Networks and Enabling Technologies

CWDM Network Protection

At the optical layer, a lightpath (an all-optical, end-to-end path on a given wavelength) is set up using a control mechanism that involves the setting up of switches and transponders at the ingress, the egress, and the intermediate nodes and equipment in addition to the fibers to set up the lightpath. Failure of equipment, fiber, or nodes can cause the lightpath to be disrupted, causing huge revenue losses. Protection of lightpaths is a means whereby failure of fiber or equipment can be overcome by other means. Protection essentially means adding some degree of redundancy or diversity to the network. The excess redundant portion of the network provides network capacity in the event of a failure or fault. This excess capacity ...