Abstract: A voltage conversion apparatus for converting from a control voltage to a supply voltage and an apparatus for converting from a supply voltage to a control voltage are described. The supply voltage is designed to power, through a coaxial cable, a data communication device, and the coaxial cable is suitable for transmitting said supply voltage signal and at least one data signal associated with said data communication device. A conversion means of the conversion apparatus is configured to convert from the control voltage to the supply voltage comprising conversion means configured to convert from a first value of control voltage Vp1 and from a second value of control voltage Vp2 to a first value of supply voltage Va1 and, respectively, to a second value of supply voltage Va2. Said first value of control voltage Vp1 and said second value of control voltage Vp2 are values of control voltage for controlling a device that is distinct from such a data communication device.

Abstract: A voltage conversion apparatus for converting from a control voltage to a supply voltage and an apparatus for converting from a supply voltage to a control voltage are described. The supply voltage is designed to power, through a coaxial cable, a data communication device, and the coaxial cable is suitable for transmitting said supply voltage signal and at least one data signal associated with said data communication device. A conversion means of the conversion apparatus is configured to convert from the control voltage to the supply voltage comprising conversion means configured to convert from a first value of control voltage Vp1 and from a second value of control voltage Vp2 to a first value of supply voltage Va1 and, respectively, to a second value of supply voltage Va2. Said first value of control voltage Vp1 and said second value of control voltage Vp2 are values of control voltage for controlling a device that is distinct from such a data communication device.

Abstract: In a telecommunication network, a modular expandable gateway connects a local area network to a wide area network and includes a base module and a plurality of add-on modules arranged in one or more stacks, the base module and the add-on modules including respective encryption/decryption engines to exchange secure information with each other, thus frustrating any possible fraudulent interception of the information at the module interconnections.

Abstract: In a telecommunication network, a modular expandable gateway connects a local area network to a wide area network and includes a base module and a plurality of add-on modules arranged in one or more stacks, the base module and the add-modules including respective encryption/decryption engines to exchange secure information with each other, thus frustrating any possible fraudulent interception of the information at the module interconnections.

Abstract: A network for distributing signals to a plurality of user apparatuses having a distribution unit with a plurality of ports, and a plurality of optical-fiber cables connected to the ports and suitable to make the plurality of ports of the distribution unit communicate with the plurality of user apparatuses. At least one of the plurality of optical-fiber cables is an electrically terminated optical cable having an optical cable with a single-mode optical fiber and an opto-electronic end portion mechanically and permanently connected to an end of the optical cable, and the opto-electronic end portion has an opto-electronic conversion device having an optic port optically aligned with and mechanically connected to, an end of the single-mode optical fiber.

Abstract: A network (100) for distributing signals to a plurality of user apparel comprising: a distribution unit (40) having a plurality of ports, and a plurality of optical-fibre cables (9) connected to said ports and suitable to make said plurality of ports of said distribution unit (40) communicate with said plurality of user apparatuses, wherein at least one of said plurality of optical-fibre cables (9) is an electrically terminated optical cable (1) comprising an optical cable (9) with a single-mode optical fibre and an opto-electronic end portion (10) mechanically and permanently connected to an end of said optical cable, and said opto-electronic end portion (10) comprises an opto-electronic conversion device,(12; 13) having an optic port optically aligned with and mechanically connected to, an end of said single-mode optical fibre.

Abstract: The present invention relates to a method and to a signal predistorter circuit for eliminiating the nonlinearities in the input/output characteristics of nonlinear stages, in particular for eliminating the third-order nonlinearities. More particularly, it relates to a method and to a predistorter circuit for external optical modulators of television signals. The method for predistortion of a signal of variable amplitude comprises the phases of: delivering the said signal to at least one first distorter circuit; biasing the said at least one first distorter circuit; distorting the said signal in the said at least one first distorter circuit; characterized in that the said phase of biasing the said at least one first distorter circuit comprises the phase of maintaining a substantially constant preset voltage value on varying the amplitude of the said signal at the said at least one first distorter circuit.

Abstract: An optical communication system is described which includes an optical source; an optical modulator, receiving a transmission signal having frequencies included within a signal band and adapted to emit a modulated optical signal of a predetermined optical bandwidth; an optical transmission line comprising an optical fiber portion; and an optical receiver adapted to receive the optical signal in the presence of a predetermined SNR in the signal band, measured in a 5 MHz band. The telecommunication system further comprises, optically connected between the optical modulator and the optical transmission line, a depolarizer comprising two polarization-maintaining optical fiber portions, optically connected with each other in such a manner that the respective polarization axes form an angle of 45.degree.

Abstract: An analog-external-modulation optical, emitter is described which comprises an electro-optical modulator and a piloting circuit. The piloting circuit comprises a pilot-tone-generating circuit; an electric control signal generated by the optical signal coming out of the modulator and a predetermined bias voltage are fed to the input of a differential amplifier the output of which is added to the pilot tone to feed an electric input of the electro-optical modulator. The RF input of the analog electric signal is connected to a linearizer circuit to which the pilot-tone-generating circuit is also connected. The output of the linearizer circuit is sent to an electric input of the electro-optical modulator through a band-stop filter adapted to eliminate the pilot tone downstream of the linearizer circuit.