This work is based on the optical switch architecture proposed in [M.M Renaud, et al., April 1997] [SBregni, G Guerra, and A Pattavina, Nov. 2002] to handle variable-length packets such as IP datagrams. This optical switch is based on an AWG device to route packets and is equipped with a fiber delay-line stage as optical input buffer. Unfortunately, this switch would require considerable buffering capability to achieve acceptable performance. A possible solution, studied in this paper, is to implement efficient packet deflection inside the optical network as a mean for solving packet contentions on outputs of optical switches. Thus, optical transport networks have been simulated to assess deflection effectiveness, based on a traffic model adherent to real IP traffic measurement. Full-mesh and wheel network topologies have been considered, comparing results to assess deflection effectiveness.

In order to support the continuous growth of transmission capacity demand, optical packet switching technology is emerging as a strong candidate, promising to allow fast dynamic allocation of wavelength-division multiplexing (channels, combined with a high degree of statistical resource sharing). This work addresses the design of optical switch architectures, based on previous proposals available in the technical literature that use an arrayed waveguide grating (AWG) device to route packets. Since the port number of currently available AWGs is a limiting factor, we propose two new modified structures which better exploit the switching capability of this component in the wavelength domain. Since a limited hardware complexity is a key requirement for all-optical switches, due to the high cost of optical components, these different node configurations are compared in terms of complexity. Traffic performance of these new structures in a full optical packet switching scenario is also examined.