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

Abstract

The corporate optical backbone network (COBNET) joint research project is aiming at the next generation of high-performance corporate networks based on wavelength division multiplexing (WDM) add/drop rings. Scalability considerations 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 receivers as merit functions. With the current performance of the add-after-drop filters, 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 network will be power limited. The projected loss performance of the filters indicates that a network with five add/drop nodes is feasible. With the addition 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 of an eight-node ring has been demonstrated.