Double crossbar circuit in node with space cross connections for transparent optical networks

There is a numerical consideration for the nodes of the transparent optical network with space cross connections realized with double crossbar configuration of circuit, with direct symmetric two channel couplers as a basic four pole circuit element. The equations for the specified double crossbar configuration are calculated for relations among the number of entrances and exits in the circuit N and the number of direct symmetric two channel couplers C, number of voltage electrode circuits V, and the most essential QoS: the characteristic for the attenuation A of the circuit and the characteristic of the signal to noise ratio SNR at the circuit can be sourced.