Abstract

The growth of data and Internet traffic, has spurred significant changes in traffic patterns across US long-haul backbone networks. Internet traffic tends to travel much longer distances than conventional voice circuits, which are typically confined to local communities of interest. Studies predict that from 2000 to 2005 average connection distances in North America will increase from 740 km to more than 2700 km.¹ This fundamental change requires an equally dramatic shift in the way networks are designed and operated—network node designs must accommodate both high bandwidth and long connection circuits which means more through traffic at most nodes. In response to these demands, network designers are introducing remotely configurable optical architectures that lower cost by increasing transparency and reducing OEO conversions. Broadcast and Select (B&S) optical add/drop multiplexers (OADM) represent an emerging architecture tailored to the particular demands of data and Internet traffic. B&S OADMs outperform traditional approaches in all the key dimensions. Compared with conventional approaches, B&S OADMs exhibit exceptionally low loss on through channels, achieving greater distances without regeneration; have built-in spectral equalization capability; offer lower first-installed cost by integrating the multiplexing, switching and equalization functions in fewer components; and scale more cost-effectively because wavelength access can be added as needed.In addition, B&S node designs have several practical advantages including simplified node structure and fiber management.

© 2002 Optical Society of America