Scalability issues in corporate optical backbone wavelength division multiplexing add/drop ring networks

The corporate optical backbone network (COBNET) joint research project is a iming at the next generation of highperformance corporate networks based on wavelength division multiplexing (WDM) add/drop rings. Scalability conside rations are of primary importance for these networks. Based on the measured spectral performance for WDM tunable add-after-drop filters fabricated in planar waveguide technology, the operational parameters of the ring network have been optimized using the bit error rates at the corresponding receive rs as merit functions. With the current performance of the add-after-drop f ilters, a ring with three add/drop nodes, each dropping and adding a single wavelength, can be constructed. If these filters are used, a COBNET-like n etwork will be power limited. The projected loss performance of the filters indicates that a network with five add/drop nodes is feasible. With the ad dition of an optical amplifier at the mid-point of the network that exactly compensates the losses in the first half of the network, the feasibility o f an eight-node ring has been demonstrated. (C) 2000 Elsevier Science B.V. All rights reserved.