Systems and methods are provided for creating a sequence of turn-up processes for amplifiers. A method, according to one implementation, includes determining when a fiber span is initially installed in an optical line system or when an Optical Line Failure (OLF) in the fiber span has recovered. The optical line system includes a first set of amplifiers deployed at an upstream node and a second set of amplifiers deployed at a downstream node, the upstream node connected to the downstream node via the fiber span. In response to determining that the fiber span is initially installed in the optical line system or that an ORL in the fiber span has recovered, the method also includes sending a flag from the upstream node to the downstream node to allow the first set of amplifiers to perform a first turn-up process before the second set of amplifiers perform a second turn-up process.

Disclosed herein is a transponder comprising a transmitter and a receiver. The transponder further comprises a receiver input amplifier, a bypass line, and a control unit configured for determining the performance of the transponder in relation to an OSNR related parameter, by controlling the transponder to generate a noise signal to be received by the receiver. The receiver input amplifier is operated to thereby cause ASE in the receiver input amplifier to facilitate the determination. A test signal is generated at the transmitter Said noise signal and said test signal, and/or one or more respective replicas thereof, are superimposed to form a combined signal to be received by said receiver to further facilitate determination of said performance related parameter based on said combined signal, wherein for generating said combined signal, said test signal is fed from the transmitter to the receiver by means of said bypass line.

The present disclosure intends to provide an optical signal from an ONU according to a desired service usage state without using the ONU and an OLT. A simulated signal light generation apparatus 10 according to the present disclosure is a simulated signal light generation apparatus 10 for simulating an uplink signal light generated in an optical network unit (ONU) in a passive optical network (PON), and the apparatus includes a usage state control unit 11 that sets a service usage state of the ONU, a signal generation unit 12 that generates an uplink signal frame according to the usage state set by the usage state control unit 11, and an electrical/optical conversion unit 13 that converts an electrical signal from the signal generation unit 12 into an optical signal, and the optical signal from the electrical/optical conversion unit 13 is repeatedly transmitted to an optical fiber core 22.

There are provided a communication device, a communication system, and a communication method. A communication device includes a first receiver configured to receive a data signal and generate a level control signal based on an initial level of the data signal and on an error rate of the data signal; and a transmitter configured to transmit the level control signal.

Aspects of the present disclosure aim at configuring an optical time domain reflectometry (OTDR) in a central office such that the OTDR is configured to be operatively coupled with and also configured to periodically poll each fiber at defined intervals and compute/store a reflection signature that can be used to compare with future signatures received from subsequent polls of the fiber to determine a fault (e.g., a fiber cut or breakage) between the central office (CO) and one or more optical network unit (ONU) over GIS.

Methods, systems, and apparatus for communicating over a radio link by devices with broadband connectivity are disclosed. In one aspect, a telecommunications device includes a first transceiver, a second transceiver, and a state monitor. The first transceiver communicates over a broadband link. The second transceiver communicates over a radio link. The radio link is a Low-Power Wide-Area Network (LPWAN) link. The state monitor includes one or more processes that monitor a state of the telecommunications device, and in response to the state of the telecommunications device being one of a plurality of pre-specified states, transmit, using the second transceiver, data specifying the state of the telecommunications device over the radio link.

A method and apparatus for automatic determination of a fiber type of at least one optical fiber span used in a link of an optical network, the method comprising the steps of measuring a length of said optical fiber span; measuring a chromatic dispersion of said optical fiber span; determining a fiber dispersion profile of said optical fiber span on the basis of the measured length and the measured fiber chromatic dispersion; and determining a fiber category and/or a specific fiber type of said optical fiber span depending on the determined fiber dispersion profile.

In some examples, fiber optic link intermittent fault detection and localization may include determining, for a fiber optic link that is to be analyzed, at least one section corresponding to the fiber optic link, at least one detection threshold corresponding to the at least one section, and a reference trace for the fiber optic link. A real-time trace may be acquired for the fiber optic link, and a comparison trace may be generated based on analysis of the reference trace and the real-time trace. Based on analysis of the at least one section to determine whether at least one section level parameter determined from the comparison trace exceeds the at least one detection threshold, an event associated with the fiber optic link may be identified.

Methods and systems for monitoring an optical network are described. An optical device may receive a data signal. The optical device may send the data signal to a test port. A measuring device may measure characteristics associated with the data signal.

An optical amplification estimation method includes by an excitation light output unit connected to a first end of a first optical transmission line, making excitation light incident on the first optical transmission line, by a monitoring unit connected to the same side as the first end of the first optical transmission line, making monitoring light incident on the first optical transmission line, the monitoring light having a wavelength different from a wavelength of the excitation light, by the monitoring unit, measuring intensity of light incident on the monitoring unit when the excitation light is incident, and intensity of light incident on the monitoring unit when the excitation light is not incident, and by an amplification estimation unit, estimating a gain of an optical signal in the first optical transmission line based on the light intensity measured in the measuring. The first optical transmission line shares a partial optical transmission line with a second optical transmission line used for an optical network unit and an optical line terminal to transmit and receive an optical signal to and from each other.