2X2 BUFFERED SWITCH FABRICS FOR TRAFFIC ROUTING, MERGING, AND SHAPINGIN PHOTONIC CELL NETWORKS

An approach to optical packet switching is discussed, which uses small , simplified optical elements for traffic routing, merging, and shapin g. The elements are constructed from 2 x 2 switches and optical delay lines, and may be implemented in a variety of technologies. They are d esigned for use with deflection routing, and even when using only six switches in a module, a deflection probability of 2.8 x 10(-7) is poss ible with a load of 0.8. The modules may also be used as 2 x 1 mergers , where a deflection probability of 10(-12) is possible with six switc hes and a total toad of 0.8. The BER performance of the modules is sim ulated with respect to crosstalk, with even relatively poor switch dev ices of -18.5 dB isolation yielding a power penalty of less than 1 dB. A networking strategy radically different from today's is discussed, driven by the need to reduce hardware, software and operating costs.