Theoretical simulation and experimental investigation on a WDM survivable unidirectional open ring network using tunable channel selecting receivers

In this paper theoretical and experimental investigations on a wavelength-division-multiplexed (WDM) reconfigurable open ring network are reported. The theoretical study is focused on network component characteristics and ring network structure. These aspects will form the basis of numerical modeling. A powerful computer aided design software “COMSIS” is used for the simulation. The simulation takes into account the most important parameters: node structure, link losses, EDFA characteristics, optical powers of the channels, and signal wavelength arrangements. The power of a new channel added at each node and its wavelength with respect to those present before the node are two important parameters in the performance analysis of this open ring network. If the performance criterion is to receive the channels with high signal to noise ratios (SNR) and a narrow spread ΔSNR, the optimal length of this ring network can reach 366 km for 4 nodes and 565 km for 8 nodes. The experimental demonstrator is composed of 4 secondary nodes incorporating tunable channel selecting receivers (TCSR´s) and erbium doped fiber amplifiers (EDFA´s). The reconfiguration and the protection of the ring is computer controlled. Experimental results of a fully connected testbed demonstrator are also presented