Patent ID: 6414771
Filing Date: 2002-07-02
Classification: H04J,H04Q

Abstract:
A controllable optical switch matrix for use in an optical node intended to be connected with a plurality of optical nodes in an optical transmission ring configuration and the controllable switch matrix intended for use in an optical node to interface with terminal equipment including a plurality of optical inputs and a plurality of optical outputs, the controllable optical switch matrix comprising:a plurality of optical inputs to which incoming optical signals are intended to be supplied; a plurality of optical outputs to which outgoing optical signals are intended to be supplied; wherein said controllable optical switch matrix has a first predetermined number of possible optical switching states, and at least first and second of said optical switch matrix optical inputs being directly optically connected in a predetermined fixed one-to-one optical connection relationship to at least first and second of said optical switch matrix optical outputs, respectively, thereby being at least first and second predetermined fixed optical connections effecting at least first and second of said optical switch matrix switch states, said first optical input of said optical switch matrix being directly optically connected to a first optical output of the terminal equipment and intended to transport optical signals to said first optical output of said optical switch matrix in a first direction of transmission, and said second optical input of said optical switch matrix being directly optically connected to a second optical output of the terminal equipment and intended to transport optical signals to said second optical output of said optical switch matrix in a second direction of transmission opposite to said first direction of transmission; and a plurality of controllable optical switch units being responsive to switch control signals for controllably optically connecting prescribed ones of said inputs to prescribed ones of said outputs and being limited to switching of only a second number of said optical switching states fewer in number than said first predetermined number of optical switching states.