Abstract: A method includes a preparation step and a key agreement step. In the preparation step, a first quantum key distribution (QKD) device at a first location and a second QKD device at a second location distant from the first location together create a quantum secured key according to a QKD protocol, and a first encryption device at the first location and a second encryption device at the second location together create a symmetrically encrypted channel between the first location and the second location using the quantum secured key. In the key agreement step, a first key agreement device at the first location and a second key agreement device at the second location together create an encryption key via the symmetrically encrypted channel.

Abstract: A method includes a preparation step and a key agreement step. In the preparation step, a first quantum key distribution (QKD) device at a first location and a second QKD device at a second location distant from the first location together create a quantum secured key according to a QKD protocol, and a first encryption device at the first location and a second encryption device at the second location together create a symmetrically encrypted channel between the first location and the second location using the quantum secured key. In the key agreement step, a first key agreement device at the first location and a second key agreement device at the second location together create an encryption key via the symmetrically encrypted channel.

Abstract: A system and method for Raman amplification of optical signals in a wavelength division multiplexing (WDM) optical transmission system includes transmitting optical signals within a transmission band via an optical waveguide between a transmitter and a receiver, Raman-amplifying the optical signals with at least one pump so as to distort an amplification profile of the Raman amplification within the transmission band, and rectifying the distorted amplification profile so as to compensate for the distortion.

Abstract: A method for optical data transmission in a wavelength multiplexing system having at least two transmission channels of different wavelengths includes determining at least one value which is a measure of a physical property of an optical data transmission path of the wavelength multiplexing system; and automatically adjusting a transmission parameter of at least one of the transmission channels as a function of the determined at least one value.

Abstract: The invention relates to a method and a communication system for releasing a data processing unit used for processing project data of a selected project. In order to obtain project-related release of a data processing unit (90), a client requests a user right for the data processing unit (90) used for processing the project data that is part of a predetermined project. A first signature (I) is verified as to the correctness thereof. The data processing unit (90) is released to process the project data that is part of the selected project only if the verification process has established that the first signature (I) is correct.

Abstract: A method for detecting and locating faults in an optical transmission path, and to an optical transmission system having such a functionality, is provided. By measuring the temporal change in the state of polarization SOP, external influences on a glass fiber cable of a long-haul transmission system, e.g., a WDM transmission system, may be detected. Such fault(s) may be localized with the aid of the relative arrival time of the polarization signal at both sides of a bidirectional transmission system.

Abstract: A system and method for Raman amplification of optical signals in a wavelength division multiplexing (WDM) optical transmission system includes transmitting optical signals within a transmission band via an optical waveguide between a transmitter and a receiver, Raman-amplifying the optical signals with at least one pump so as to distort an amplification profile of the Raman amplification within the transmission band, and rectifying the distorted amplification profile so as to compensate for the distortion.

Abstract: A method for optical data transmission in a wavelength multiplexing system having at least two transmission channels of different wavelengths includes determining at least one value which is a measure of a physical property of an optical data transmission path of the wavelength multiplexing system; and automatically adjusting a transmission parameter of at least one of the transmission channels as a function of the determined at least one value.

Abstract: A method for detecting and locating faults in an optical transmission path, and to an optical transmission system having such a functionality, is provided. By measuring the temporal change in the state of polarization SOP, external influences on a glass fiber cable of a long-haul transmission system, e.g., a WDM transmission system, may be detected. Such fault(s) may be localized with the aid of the relative arrival time of the polarization signal at both sides of a bidirectional transmission system.

Abstract: The invention relates to a method and a communication system for releasing a data processing unit used for processing project data of a selected project. In order to obtain project-related release of a data processing unit (90), a client requests a user right for the data processing unit (90) used for processing the project data that is part of a predetermined project. A first signature (I) is verified as to the correctness thereof. The data processing unit (90) is released to process the project data that is part of the selected project only if the verification process has established that the first signature (I) is correct.