Methods for configuring an optical link in which a distribution of transmission data rates and line rates are configured for a predetermined amount of optical bandwidth to maximize transmission capacity. In these methods, a controller of an optical network obtains input parameters that include a signal-to-noise ratio (SNR) for optical signals and an allocated bandwidth of the optical link, further obtains, for each line rate, a mapping of transmission data rates along a frequency spectrum of the allocated bandwidth compatible with the SNR, and generates a channel plan in which a number of traffic modes and a distribution of a plurality of channels in the allocated bandwidth are set to maximize transmission capacity. The plurality of channels is used for transmitting the signals on the optical link. The controller configures at least one optical network element in the optical network to establish the optical link based on the channel plan.

An optical communication system includes an optical line terminal and a plurality of optical network unit connected by optical transfer paths. The optical line terminal includes a light transmitting/receiving unit and a control unit. The light transmitting/receiving unit transmits/receives an optical signal to/from the plurality of optical network units via the optical transfer paths. The control unit performs control so as to change a launch power of an optical signal that is transmitted from the light transmitting/receiving unit, such that, when it is recognized, regarding at least one optical network unit, that a monitoring value that changes according to a receive signal quality of an optical signal transmitted from the light transmitting/receiving unit has changed to a value indicating deterioration, a receive power of an optical signal in each of the plurality of optical network units is lower than or equal to an upper limit value and a receive power of an optical signal in the optical network unit in which the monitoring value has changed to a value indicating deterioration is higher than or equal to a lower limit value.

A communication system transmits relay data through a communication path including a plurality of sections in which different communication schemes are used. A relay communication device is provided between a first section and a second section which are adjacent sections. The relay communication device includes a receiving unit receiving the relay data from the first section through a frame of a first communication scheme, and a relaying unit configuring, in a frame of a second communication scheme used to transmit the relay data to a relay destination, signal quality information representing signal quality calculated for a physical link in each of the sections through which the relay data is transmitted before arriving at the relay communication device, and outputting the frame of the second communication scheme to the second section.

There is herein provided a method for measuring the GOSNR that can be implemented using commercial-grade transceivers and which accounts for linear optical impairments (e.g. PMD, PDL and CD) and transceiver intrinsic impairments. The method may be implemented using an Optical Spectrum Analyzer (OSA) and either the system transceivers or other commercial-grade transceivers. The proposed measurement method is based on mixed optical and electronic technologies, using an OSA and a transceiver pair. By measuring a signal quality metric Q.sub.m and the OSNR under varied power and ASE noise conditions, a constant value R.sub.BW that relates the GOSNR to the signal quality metric Q.sub.m is derived. The GOSNR is then obtained from these results.

This application provides an optical power commissioning method, a commissioning system, a control device, and a commissioning station. The commissioning system includes a control device and one or more commissioning stations. The method includes the control device first identifies one or more to-be-commissioned services on which optical power commissioning needs to be performed, the control device sends, based on the to-be-commissioned service, commissioning information to the one or more commissioning stations on which the to-be-commissioned service passes through, where the one or more commissioning stations perform parallel optical power commissioning based on the commissioning information, and the one or more commissioning stations perform optical power commissioning based on the commissioning information. According to this application, a plurality of services and a plurality of commissioning stations can be commissioned concurrently.

Optical transmission system transmits WDM signal from first node to second node via optical fiber. The optical transmission system includes: first OCM that detects optical power of each wavelength channel of the WDM signal in the first node; second OCM that detects optical power of each wavelength channel of the WDM signal in the second node; first processor that calculates linear SNR of each wavelength channel based on the optical power of each wavelength channel detected by the second OCM; second processor that calculates non-linear SNR of each wavelength channel based on the optical power of each wavelength channel detected by the first OCM; third processor that calculates GSNR for each wavelength channel using the linear SNR and the non-linear SNR; and fourth processor that controls transmission power of each wavelength channel of the WDM signal based on the GSNR of each wavelength channel.

An object of the present invention is to provide an optical transmission system capable of controlling a transmission capacity and a signal processing load of a MIMO equalizer, without depending on the number of propagation modes of the optical fiber. The present optical transmission system includes an optical fiber 11 with the number of spatial modes being L (an integer of 2 or greater), an optical multiplexer 13 connected to one end of the optical fiber 11 and configured to input M (a natural number of L or less) signal beams of light to the optical fiber 11 and cause the M input signal beams of light to be propagated for each of the spatial modes of the optical fiber 11, an optical demultiplexer 14 connected to another end of the optical fiber 11 and configured to demultiplex a propagated beam of light propagated through the optical fiber 11 for each of the spatial modes of the optical fiber 11, N (N=L) receivers 15 configured to each receive a demultiplexed beam of light obtained by demultiplexing the propagated beam of light, a signal generation apparatus 17 configured to generate P (an integer of from M to L) combined signals from the N received signals, and a P×M MIMO equalizer 16 configured to receive the P combined signals to output M demodulated signals.

An apparatus and method are disclosed with some embodiments including an analog and time to digital converter (ATDC) including a receiver, the receiver for receiving an analog channel input for conversion to a digital data, the digital data having at least one bit, and a defined absolute reference time stamp, the defined absolute reference time stamp representing an absolute reference time associated with conversion of the analog channel input to the digital data and an analog-to-digital converter, the converter converting the analog channel input to the digital data.

Provided are a communication device, a communication controlling method, and a non-transitory computer-readable medium storing a communication controlling program that each make it possible to grasp the condition of communication quality. A communication device (1) includes acquiring means (2) configured to acquire quality information concerning a burst error that has occurred in an optical communication line. The communication device (1) includes estimating means (3) configured to estimate a first index value based on the quality information acquired by the acquiring means (2), the first index value indicating a degree of influence of the burst error on communication quality in a first communication device.

A communication system is configured to generate a perturbed signal by perturbing an amplitude of a spectrum of an original signal in one or more spectral regions, and to propagate the perturbed signal through components of the communication system. The communication system is further configured to obtain a measurement of the perturbed signal in a first spectral region of the one or more spectral regions following the propagation of the perturbed signal, and to calculate an estimate of an impairment associated with the communication system based on the measurement.