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 object is to provide an optical transmission apparatus in which dummy lights can be arranged according to an arrangement of optical signals. A plurality of optical signals of different frequencies arranged in a frequency grid are input to a multiplexing unit and the multiplexing unit multiplexes the input optical signals. A dummy light output unit identifies a dummy light to be arranged in the frequency grid based on the plurality of optical signals and outputs the dummy light. A multiplexing unit multiplexes an optical signal multiplexed by the multiplexing unit and the dummy light output from the dummy light output unit to output a wavelength-multiplexed optical signal L.

Accommodation design for wavelength and sub-λ paths in a communication network is performed. If sub-λ path accommodation is possible according to search for a wavelength path present in a single-hop logical route, the accommodation in the wavelength path is executed. If sub-λ path accommodation is possible according to search for a wavelength path present in a multi-hop logical route, a logical route is selected based on the wavelength path and the sub-λ path is accommodated in the wavelength path. Additionally, each physical route suitable for the sub-λ path accommodation is searched for. If the route can accommodate a wavelength path set in a single-hop logical route by available wavelength allocation, the sub-λ path is accommodated in the wavelength path. Furthermore, routes in consideration of overlapping of nodes, pipelines, and links and operation rate are selected based on information about the start and end nodes of each of redundant routes.

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.

Processing a received optical signal in an optical communication network includes equalizing a received optical signal to provide an equalized signal, demodulating the equalized signal according to an m-ary modulation format to provide a demodulated signal, decoding the demodulated signal according to an inner code to provide an inner-decoded signal, and decoding the inner-decoded signal according to an outer code. Other aspects include other features such as equalizing an optical channel including storing channel characteristics for the optical channel associated with a client, loading the stored channel characteristics during a waiting period between bursts on the channel, and equalizing a received burst from the client using the loaded channel characteristics.

The Bi-Di coherent transmission system is configured with at least one pair of modules coupled to one another via a single fiber. The modules each are configured with a pair of laser outputting two reference signals at respective different wavelengths λ.sub.1o and λ.sub.2o, photonic transceiver and a wavelength division multiplexer (WDM) coupler. The photonic transceivers each have transmitter and receiver branches integrated in a photonic circuit and receiving the reference signals. The transmitter is configured to modulate the received reference signals λ.sub.1oT and λ.sub.2oT which are further coupled into the WDM coupler. The WDM couplers each sort out one of the modulated signals and transmit the other modulated signal such that the transmitted modulated signal at different wavelengths λ.sub.1oT and λ.sub.2oT are coupled into respective opposite ends of the fiber and propagate towards one another in opposite directions. The transmitted modulated signals arc coupled into respective branches through the WDM couplers with each transmitted modulated signal interfering with the reference signals at wavelengths λ.sub.1oT and λ.sub.2oT. The photodiodes of respective receiving brandies are configured to detect a beat frequency of the interfering signals at the same wavelength.

A radio over fiber (RoF) system and a nonlinear compensation method, where the RoF system includes a BBU and an RRU, the RRU includes an electrical component, and the BBU includes a downlink and a feedback link. A predistortion module and an optical component are disposed on the downlink, an input end of the feedback link is connected to an output end of the optical component, and the feedback link is configured to feed back, to the predistortion module, a nonlinear signal output by the optical component. The RoF system further includes a temperature detection module configured to detect a temperature value of the electrical component, and transmit the temperature value to the predistortion module. The predistortion module is configured to perform digital predistortion DPD on a baseband signal based on the temperature value and the nonlinear signal.

A link group configuration method includes obtaining first status information of M links between a source end device and a receive end device, where the first status information indicates a status of a differential delay between any two of the M links, obtaining first capability information of the receive end device, where the first capability information indicates a first capability of performing differential delay compensation on the M links by the receive end device, grouping N of the M links into a first link group based on the first status information and the first capability information, and sending first configuration information to a second device, where the first configuration information includes information used to indicate the first link group.

Embodiments of this application disclose an optical switch. The optical switch includes at least one first port, at least one second port, a first wavelength division multiplexing WDM apparatus, an optical splitter, an optical monitoring apparatus, and an optical switching apparatus. The first port is configured to transmit an input first optical signal to the first WDM apparatus, where the first optical signal is a multi-wavelength signal. The first WDM apparatus is configured to demultiplex the first optical signal. The optical splitter is configured to split a demultiplexed first optical signal to obtain a first sub-signal and a second sub-signal. The optical switching apparatus is configured to perform optical switching on the first sub-signal. The second port is configured to output a first sub-signal obtained after optical switching. The optical monitoring apparatus is configured to perform optical performance monitoring on the second sub-signal.

This application discloses an optical signal control method and apparatus, and belongs to the optical communication field. The apparatus includes: a light source, configured to output a first optical signal; an optical switch module, configured to receive the first optical signal and an external second optical signal, and output a third optical signal; and a detection module, configured to detect whether a power change of the second optical signal on at least one wavelength channel is greater than a preset power change threshold, if so, the optical switch module adjusts on/off states of at least one wavelength channel of the received first optical signal and the at least one wavelength channel of the received second optical signal, so that an adjusted first optical signal and an adjusted second optical signal are combined to obtain the third optical signal.