Abstract: A basic element for the interconnection network of a fast packet switching node, where a synchronization is made at bit input stream level, the cell beginning is identified and a stream conversion from the serial form to a word parallel form is performed. Cells are thus transformed in a completely parallel form and in the same form they are cyclically discharged in the subsequent cell time in a memory, where cells are written and read in a shared way on the basis of instructions given by a control unit, thus performing the switching function. The control unit is essentially based on the use of a content-addressed associative memory, where a fraction of the routing header and a code indicating the time sequence on which the cells are stored. Memory outgoing cells are reconverted from a completely parallel form to a form having the length of one word and therefore in a completely serial form at a bitrate equal to the input one.

Abstract: A fast packet and frequency switch, with inputs and outputs connected to optical fibers, each allowing the transit of a certain number of different-wavelength optical carriers, modulated by serial information flows organized into packets. The packets are phase-realigned and their labels are converted under the control of external processors designed to set-up and break connections. Then a frequency conversion of the optical carriers allotted to packets is carried out and the packets are recombined into a single fiber by a passive recombination network in order to be stored into an optical loop memory, which is an optical fiber delay line. Each optical packet flow is extracted at suitable times, is frequency-converted and, among the various frequencies obtained, there are selected only those to be sent to corresponding output fibers outgoing from the switch, after having been recombined with those of the other converted flows.