Optical Routing in Broadband Fibre Communication Networks

Optical fibre networks offer low-loss high-bandwidth communication routes. But even more important for broadband communication, they offer an extra dimension for information transfer, namely the wavelength. In point-to-point links, a multiple of the single-wavelength capacity can be realised, or a variety of concurrent signals with different format (such as analog CATV along with highspeed data).
The impact on multi-access networks, however, is more profound. Electronic multi-access networks for data transfer are limited in their capacity due to collisions which may occur between data packets injected at the various terminal nodes. Also the electronic processing in the routing nodes forms a bottleneck. In data communication networks, sophisticated protocols are needed to overcome the collision problems; the inherent speed limitations of these protocols form another bottleneck. In optical fibre multi-access networks, however, multiple mutually independent transparant communication routes may be set up at different wavelengths. The wavelength-dimension offers an extra degree of freedom for data routing, besides the conventional dimensions of space and time. Thus the data collision problems can be significantly alleviated, as well as the protocol handling bottleneck. In short, multiwavelength optical networking is a very promising technology for future broadband data
communication networks.
An overview will be presented of the principles and techniques of multi-wavelength optical networking, and of a number of projects with various applications in the area of data communication and network reconfiguration, while touching upon the optical components needed for multi-wavelength routing and wavelength conversion.