Abstract: An optical telecommunication system includes a number of transparent passive optical networks (TONs). Each TON connects a respective group of terminals and the head end of each TON is connected to a common central switching node. Each terminal includes selecting a wavelength/time channel for forming a connection with another terminal within the respective TON or within another TON. The central switching node comprises an optical spatial/wavelength switch arranged to provide switched connections between subscribers connected to different TONs.

Abstract: A generalized connection network includes a first and second sub-network interconnected by a branching circuit having N inputs and N outputs. The branching circuit has N, two-state branching elements interconnected so as to be able to replicate a signal coupled to any one of the inputs to each of up to N outputs. The cyclic connection scheme provided by an additional two-state switch permits a net reduction in the total number of two-state switches necessary to form a generalized connection network.