Method and apparatus for capacity-efficient restoration in an optical communication system

An optical fiber communication system, comprising:

• a plurality of nodes interconnected by optical fibers, each node including an optical layer cross-connect switch interconnected to at least two interface elements, each interface element including at least two optical fiber connections, and each interface element connecting to a separate node via said at least two optical fiber connections;
• each said optical fiber connection including at least three channel groups, at least one channel group including predetermined channels allocated for restoring communication in response to a failure occurring in one of said optical fiber connections, and at least two channel groups including predetermined channels allocated for carrying user traffic;
• said optical switch being enabled for switching at least a portion of said channel groups from a first optical fiber connection to a second optical fiber connection in response to a failure occurring in the first optical fiber connection, the second optical fiber connection being enabled for carrying the same or greater capacity of information as carried by said portion of switched channel groups in the first optical fiber connection,
• wherein, said channel groups include priority levels for switching said channel groups to a second optical fiber connection in response to a failure occurring in a first optical fiber connection carrying said channel groups, said priority levels including at least a highest priority level and a second highest priority level.