Abstract: System for integration of channels with quantum information in communication networks. The network includes fibre-optic segments and conventional equipment, whilst a quantum key distribution (QKD) system has devices for the exchange of information by a quantum channel. The system includes at least one filter for each one of the exchange devices and at least one unit for managing conventional and quantum channels that reduces the noise in quantum channels and has at least the following functions: attenuation of insertion power of conventional channels in the network; different polarizations in the various conventional and quantum channels; and changes of wavelength assignment in not only conventional but also quantum channels.

Abstract: A hybrid circuit for an electric operating and scanning interface is especially applicable to electronic recorders of electromechanical telephone stations. The hybrid circuit controls voltage and current parameters on different elements of the station in different situations. The hybrid circuit scans the condition of telephone station elements controlled by it, and programmably applies and receives current and voltage to and from the telephone station elements on which it acts.