Architectural considerations in the design of WDM-based optical access networks

We describe a WDM-based optical access network architecture for providing b roadband Internet services. The architecture uses a passive collection and distribution network and a configurable Feeder network. Unlike earlier pape rs that concentrate on the physical layer design of the network, we focus o n higher layer architectural considerations. In particular we discuss the j oint design of the electronic and optical layers including: WDM Medium Acce ss Control protocols; the choice of electronic multiplexing and switching b etween the IF and WDM layers; joint optical and electronic protection mecha nisms; network reconfiguration algorithms that alter the logical topology o f the network in response to changes in traffic; and traffic grooming algor ithms to minimize the cost of electronic multiplexing. Finally we also disc uss the impact of the optical topology on higher layer protocols such as IP routing, TCP flow control and multi-layer switching. (C) 1999 Elsevier Sci ence B.V. All rights reserved.