The George Washington University Richard A. Barry RIA: Fundamental Limits and Practical Designs of Integrated All-Optical Networks In an All-Optical Network (AON), the signals remain in the optical domain from the origin to the destination. Since electronic packet or circuit switched routing cannot be implemented in an AON, other routing methods are required. Wavelength Routing is an attractive option where the path of a signal through the network is determined by the wavelength of the signal, the state of the network switches and wavelength changing devices. The focus here is on Wavelength Routing AONs which support multiple point and multiple rate sessions. So far only single rate point to point networks have been investigated. In the point to point case, many switching topologies can be implemented all-optically in a straightforward manner. This is not the case in the multi-point environment and new design methodologies are required. AONs supporting heterogeneous users with widely varying bandwidth requirements pose interesting questions requiring innovative engineering solutions. This research considers two network models: 1) passive networks which do not contain any switches or configurable devices, and 2) configurable networks which use switches and/or configurable wavelength changing devices to alter the paths of wavelengths through the network. Passive AONs are suitable for Local and Metropolitan Area Networks, while configurable AONs will find applications in Wide Area Networks. Recently it has been shown that wavelength routing can significantly increase the capacity of a passive AON over a broadcast star in the point-to-point single rate environment. It is likely that this conclusion will hold in an integrated environment, and how to achieve this performance advantage is a question which will be addressed. Configurable AONs are scalable and therefore appropriate for a Wide Area Network. Previous studies have shown that for "irregular" topologies, wavelength changing devices can dramatically increase throughput. What is not understood is what topological properties make wavelength changers useful. The fundamental issues in the design of networks with and without wavelength changers and the practical trade-offs will be investigated.
