Self-healing meshed network using logical ring structures

A hybrid ring comprising

• pairs of unidirectional communication paths for propagating multiplexed subchannels,
• add-drop multiplexer (ADM) nodes interposed in at least some of said pairs, the combination of each pair of unidirectional communication paths with any said interposed ADM nodes forming a hybrid ring segment, which is independent of other hybrid ring segments formed by other of said pairs and interposed ADM nodes and
• cross-connect nodes terminating each of the ends of said segments and of said pairs without ADM nodes, each of said cross-connect nodes including means for routing said subchannels from an incoming one of said segments or of said pairs without ADM nodes to an outgoing one of said segments or of said pairs without ADM nodes to configure the hybrid ring as a cascade of predetermined ones of said segments or of said pairs without ADM nodes and preselected one of said cross-connect nodes, thereby coupling each of the ADM nodes to the other ADM nodes on the hybrid ring,
• the circuitry thereby being configured so that the propagation of said multiplexed subchannels over any of the hybrid rings is uninterrupted by the failure of any one of the ADM nodes, of any one of said paths, or of any one of said cross-connect nodes.

Circuitry for configuring a hybrid ring composed of pairs of unidirectional communication paths and add-drop multiplexer nodes, the circuitry comprising

• a plurality of hybrid ring segments each propagating a signal composed of a plurality of multiplexed subrate channels and each of said segments being independent of one another, and
• cross-connect nodes terminating each of the ends of said segments, each of said nodes including
• means for demultiplexing each said signal propagating on each of said segments connected as an input to each said node to generate corresponding ones of said subrate channels,
• means for switching said corresponding ones of said subrate channels to assigned ones of said segments on a one-to-one basis, and
• means for multiplexing said corresponding ones of said subrate channels assigned to individual ones of said segments to propagate said corresponding ones of said subrate channels onto said individual ones of said segments,
• wherein selected ones of said hybrid ring segments and specified ones of said cross-connect nodes in combination realize the hybrid ring,
• the circuitry thereby being configured so that the propagation of said multiplexed subchannels over any of the hybrid rings is uninterrupted by the failure of any one of the ADM nodes, of any one of the paths, or of any one of said cross-connect nodes.

A meshed network comprising

• a plurality of hybrid ring segments each composed of pairs of unidirectional communication paths propagating multiplexed subchannels and each of said segments being independent of one another,
• a plurality of add-drop multiplexer nodes, each of said hybrid ring segments being defined between two of said add-drop multiplexer nodes, and
• a plurality of cross-connect nodes, each of said cross-connect nodes being interposed between at least three of said hybrid ring segments for interconnecting the multiplexed subchannels of said hybrid ring segments connected to each of said cross-connect nodes into a plurality of possible hybrid rings for maintaining subchannels even in the presence of a failure of any one of said hybrid ring segments by rearranging the connection of said multiplexed subchannels into different ones of said possible hybrid rings,
• the network thereby being configured so that the propagation of said multiplexed subchannels over any of the hybrid rings is uninterrupted by the failure of any one of the ADM nodes, of any one of said paths, or of any one of said cross-connect nodes.