Optical Switch Fabrics for Terabit-Class Routers and Packet Switches

Next-generation switches and routers may rely on optical switch fabrics to overcome cost, power, space and scalability problems that arise in sizing traditional electrical backplanes into the terabit regime. However, several technological and architectural problems must be overcome to be able to use such an approach. The reconfiguration times of optical packet fabrics are longer than those of electronic fabrics. Even though we can relax some of the constraints in switching speed by utilizing appropriate packetization and scheduling mechanisms, we need to adapt optical technology to the needs of packet switching. In this paper we present an optical packet fabric design, based on arrayed waveguide gratings and fast wavelength tuning and present methods for solving the technical problems of fast switching.