Optical ethernet overlay for loop topology network

Abstract

A telecommunications network having a ring topology overlaid with an Ethernet. An add/drop multiplexer (ADM) employing wave division multiplexing (WDM) hardware is implemented at each node of a multi-node fiber-based network. The ADM contains a robust protection scheme for reliability. The WDM allows the data traffic of the incumbent network, for example, a SONET network, to be carried over one or more frequencies while the data traffic of one or more packet-based networks may be carried over one or more other frequencies. Each ADM has protection switches, for example, micro-electromechanical switches. The protection switches provide a no-load bypass capability. A failed node can be shunted from the ring, allowing the Ethernet data to bypass the node uninterrupted. The switches also provide a self-test capability. The ADM interfaces can be checked by coupling the receiving path and the transmission path. This allows the ADM transceivers to communicate with each other.

Dependencies are inferred from the claim text.