Abstract: Provided is a network node for a coherent optical wavelength division multiplex (WDM) transmission network including at least one remote port which is adapted to receive from and/or output to neighboring network nodes an optical WDM signal including one or more optical channel signals each lying within an optical channel of an optical WDM transmission band and a predetermined number N of local ports, each local port being adapted to receive from a dedicated coherent optical transmitter an optical add channel signal which is to be integrated in an optical WDM signal that is output at a remote port and/or each local port being adapted to output to a respective dedicated optical receiver an optical drop channel signal.

Abstract: An apparatus for management of a spectral capacity of a wavelength division multiplexing, WDM, system includes at least one pair of transmission fibers provided for transporting optical signals. Each transmission fiber of a transmission fiber pair is connected to a first port of an optical circulator having at least two additional ports and adapted to transmit an incoming optical signal entering one of its ports via its next port. WDM subsystems configured with counter-propagating assignable wavelengths are connected to associated ports of the optical circulator of the apparatus.

Abstract: An apparatus for management of a spectral capacity of a wavelength division multiplexing, WDM, system includes at least one pair of transmission fibers provided for transporting optical signals. Each transmission fiber of a transmission fiber pair is connected to a first port of an optical circulator having at least two additional ports and adapted to transmit an incoming optical signal entering one of its ports via its next port. WDM subsystems configured with counter-propagating assignable wavelengths are connected to associated ports of the optical circulator of the apparatus.

Abstract: An apparatus for monitoring a performance of an Ethernet data stream, EDS, said apparatus comprising: an evaluation unit adapted to evaluate sync headers and block type fields of line code vectors of the Ethernet data stream, EDS; and a counter unit adapted to increment at least one performance counter in response to the evaluated sync header and the evaluated block type field of each line code vector of the Ethernet data stream, EDS.

Abstract: A method for establishing bidirectional communication links includes: supplying, to at least two optical transceiver modules at each side of at least two optical paths, a multiplexed optical CW signal comprising at least two optical CW signals having the same differing wavelengths, and modulating the multiplexed optical CW signal according to modulation signals; creating, at each side of the optical paths, at least two first and second optical transmit signals by optically filtering the modulated optical signals so that only a single wavelength remains, and routing pairs of a first and second optical transmit signal to the optical paths, wherein the optical transmit signals of each pair have differing wavelengths and wherein the optical transmit signals transmitted in the same direction over the same optical paths have differing wavelengths; receiving each optical transmit signals at a dedicated optical transceiver module by mixing it with the multiplexed optical CW signal.

Abstract: A method for establishing bidirectional communication links includes: supplying, to at least two optical transceiver modules at each side of at least two optical paths, a multiplexed optical CW signal comprising at least two optical CW signals having the same differing wavelengths, and modulating the multiplexed optical CW signal according to modulation signals; creating, at each side of the optical paths, at least two first and second optical transmit signals by optically filtering the modulated optical signals so that only a single wavelength remains, and routing pairs of a first and second optical transmit signal to the optical paths, wherein the optical transmit signals of each pair have differing wavelengths and wherein the optical transmit signals transmitted in the same direction over the same optical paths have differing wavelengths; receiving each optical transmit signals at a dedicated optical transceiver module by mixing it with the multiplexed optical CW signal.

Abstract: A chromatic dispersion compensation apparatus for automatic compensation of chromatic dispersion of signals transmitted via an optical link at predetermined wavelengths of WDM channels within a predetermined band. A tapping unit taps optical signals received by the chromatic dispersion compensation apparatus via the optical link at predetermined wavelengths and supply them to an optical coherent receiver adapted to tune its local oscillator to WDM channels to generate corresponding analog electrical signals of the WDM channels which are sampled by an analog digital converter to provide digital signal samples of WDM channels processed by a digital signal processor of the chromatic dispersion compensation apparatus to calculate an estimate residual chromatic dispersion value of the received optical signals.

Abstract: A chromatic dispersion compensation apparatus for automatic compensation of chromatic dispersion of signals transmitted via an optical link at predetermined wavelengths of WDM channels within a predetermined band. A tapping unit taps optical signals received by the chromatic dispersion compensation apparatus via the optical link at predetermined wavelengths and supply them to an optical coherent receiver adapted to tune its local oscillator to WDM channels to generate corresponding analog electrical signals of the WDM channels which are sampled by an analog digital converter to provide digital signal samples of WDM channels processed by a digital signal processor of the chromatic dispersion compensation apparatus to calculate an estimate residual chromatic dispersion value of the received optical signals.

Abstract: An apparatus for monitoring a performance of an Ethernet data stream, EDS, said apparatus comprising: an evaluation unit adapted to evaluate sync headers and block type fields of line code vectors of the Ethernet data stream, EDS; and a counter unit adapted to increment at least one performance counter in response to the evaluated sync header and the evaluated block type field of each line code vector of the Ethernet data stream, EDS.

Abstract: The invention relates to a method for the transmission of a digital signal in inverse multiplexing, particularly via an Optical Transport Network (OTN), in which a digital signal to be transmitted, which is split into a certain number M of several sub-signals, where each sub-signal of a transmit side of a transmission line assigned exclusively to this sub-signal is transmitted to a reception side of the assigned transmission line, and in which, on the reception side of the transmission lines, the sub-signals are reassembled to a digital reception signal.

Abstract: A method for automatic confirmation of an optical network element optical modules each having multiple fibers; a fiber shuffle interconnector having ports to which said optical modules are connected; and a configuration unit which performs an automatic configuration of said optical network element by controlling all optical modules connected to said fiber shuffle interconnector to transmit a fiber identifier associated with a fiber of the respective optical module to the respective port of said fiber shuffle interconnector to which said optical module is connected, wherein said fiber shuffle interconnector forwards the received fiber identifier via another port of said fiber shuffle interconnector to another optical module of said optical network element which detects said forwarded fiber identifier being monitored by said configuration unit to generate a connectivity matrix indicating the connection of said optical modules to said fiber shuffle interconnector on the basis of the detected fiber identifiers.

Abstract: A method for automatic confirmation of an optical network element optical modules each having multiple fibres; a fibre shuffle interconnector having ports to which said optical modules are connected; and a configuration unit which performs an automatic configuration of said optical network element by controlling all optical modules connected to said fibre shuffle interconnector to transmit a fibre identifier associated with a fibre of the respective optical module to the respective port of said fibre shuffle interconnector to which said optical module is connected, wherein said fibre shuffle interconnector forwards the received fibre identifier via another port of said fibre shuffle interconnector to another optical module of said optical network element which detects said forwarded fibre identifier being monitored by said configuration unit to generate a connectivity matrix indicating the connection of said optical modules to said fibre shuffle interconnector on the basis of the detected fibre identifiers.

Abstract: The invention relates to a method for the transmission of a digital signal in inverse multiplexing, particularly via an Optical Transport Network (OTN), in which a digital signal to be transmitted, which is split into a certain number M of several sub-signals, where each sub-signal of a transmit side of a transmission line assigned exclusively to this sub-signal is transmitted to a reception side of the assigned transmission line, and in which, on the reception side of the transmission lines, the sub-signals are reassembled to a digital reception signal.

Abstract: In the high-bit-rate transmission of optical signals in an optical transmission system having N optical fiber link sections with, in each case, one optical fiber and one dispersion compensation unit, the absolute-magnitude compensations of the first to Nth dispersion compensation units are dimensioned in such a way that the first to N?1-th fiber link sections is/are overcompensated, in each case, by approximately the same absolute magnitude overcompensation. Furthermore, the absolute-magnitude compensation of the Nth dispersion compensation unit is dimensioned in such a way that the accumulated fiber dispersion at the output of the optical transmission system is virtually completely compensated.

Abstract: For the purpose of optical transmission, narrow pulses are generated with the aid of at least two modulators (M1, M2), in which use is made of drive signals (TS1, TS2) of the same frequency with different amplitudes, the modulators having different working points.

Abstract: Method for controlling the operating range of a modulator, and an associated drive unit, the operating range of the modulator being controlled via a control circuit such that the operating range is stable over a long period of time and in different operating conditions, relative to the transmission characteristic of the modulator.

Abstract: In the high-bit-rate transmission of optical signals in an optical transmission system having N optical fiber link sections with, in each case, one optical fiber and one dispersion compensation unit, the absolute-magnitude compensations of the first to Nth dispersion compensation units are dimensioned in such a way that the first to N−1-th fiber link sections is/are overcompensated, in each case, by approximately the same absolute magnitude overcompensation. Furthermore, the absolute-magnitude compensation of the Nth dispersion compensation unit is dimensioned in such a way that the accumulated fiber dispersion at the output of the optical transmission system is virtually completely compensated.

Abstract: Method for controlling the operating range of a modulator, and an associated drive unit, the operating range of the modulator being controlled via a control circuit such that the operating range is stable over a long period of time and in different operating conditions, relative to the transmission characteristic of the modulator.