2×2 buffered switch fabrics for traffic routing, merging, and shaping in photonic cell networks

An approach to optical packet switching is discussed, which uses small, simplified optical elements for traffic routing, merging, and shaping. The elements are constructed from 2/spl times/2 switches and optical delay lines, and may be implemented in a variety of technologies. They are designed for use with deflection routing, and even when using only six switches in a module, a deflection probability of 2.8/spl times/10/sup -7/ is possible with a load of 0.8. The modules may also be used as 2/spl times/1 mergers where a deflection probability of 10/sup -12/ is possible with six switches and a total load of 0.8. The BER performance of the modules is simulated with respect to crosstalk, with even relatively poor switch devices 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.