Bringing Photonics to Broadband Switching

Abstract

Growing demand for high‐bit‐rate, large switching fabrics is forcing a reexamination of conventional electronic interconnection systems. A conclusion of this examination is that any large switching system will require thousands of connections at high rates to communicate the volume of data anticipated in future broadband switches. For example, a broadband switching fabric with 256 inputs and outputs each running at 622 Mbit/s would require a throughput of 160 Gbit/s. An approach to relieve the electronic interconnection bottleneck is to use optical connections. Photonics allows chip‐to‐chip and board‐to‐board communications at high rates to support building large switching fabrics. This paper discusses an approach that is being pursued to move the current state‐of‐the‐art photonics work into a switching fabric capable of routing, in real‐time, asynchronous transfer mode (ATM) cells received from 622 Mbit/s lines through a switching fabric that has 256 inputs and 256 outputs.