Example embodiments of this application provide a method and an apparatus for transmitting a service flow based on FlexE. The method includes: sending, by a first network device, a first FlexE overhead frame to a second network device, where the first network device and the second network device transmit a service flow using a first FlexE group, and the first FlexE overhead frame includes FlexE group adjustment identification information and PHY information of a physical layer (PHY) included in a second FlexE group; receiving, by the first network device, a second FlexE overhead frame sent by the second network device, where the second FlexE overhead frame includes FlexE group adjustment acknowledgment identification information; adjusting, by the first network device, the first FlexE group to the second FlexE group; and sending, by the first network device, the service flow to the second network device based on the second FlexE group, to dynamically adjust a FlexE group.

An injection locked transmitter for an optical communication network includes a master seed laser source input substantially confined to a single longitudinal mode, an input data stream, and a laser injected modulator including at least one slave laser having a resonator frequency that is injection locked to a frequency of the single longitudinal mode of the master seed laser source. The laser injected modulator is configured to receive the master seed laser source input and the input data stream, and output a laser modulated data stream.

A transmission/reception device is configured to convert an optical signal based on a plurality of first optical signals having frequency bands different from each other into an electric signal and output the electric signal as a plurality of first electric signals; receive the plurality of first electric signals, change frequency bands of some or all of a plurality of second electric signals to narrow an interval between frequency bands of two second electric signals having frequency bands adjacent to each other, and output, as third electric signals, electric signals; to receive a plurality of the third electric signals, combine and output the plurality of third electric signals as a fourth electric signal; and receive the fourth electric signal, convert the fourth electric signal into an optical signal, and output the optical signal as a second optical signal.

A node (10) includes multiplexing unit (11) that multiplexes a plurality of subcarrier signals for performing optical wavelength multiplexing communication into a wavelength group signal; output unit (12) that outputs the multiplexed wavelength group signal to an optical transmission line; pre-multiplexing level correction unit (13) that corrects a level deviation between the subcarrier signals before the multiplexing based on an optical level of the wavelength group signal in the output unit (12); and post-multiplexing level correction unit (14) that corrects a level deviation of the wavelength group signal after the multiplexing including the corrected subcarrier signals based on the optical level of the wavelength group signal in the output unit (12).

An optical transmission system (10) includes a plurality of transmission devices such as transponders (TPs) and optical cross-connects (OXCs) installed in each of stations (11-15) connected via a communication network, a control device (20), and a substitute OXC (502) serving as a substitute transmission device. The control device 20 is installed in a control station (14) of the stations. The control device (20) controls the transmission devices of the stations (11-15) in a centralized manner in accordance with physical network (NW) configuration information (20D) stored in a DB (21) and including config information. When a transmission device is replaced with a new OXC (5o3) serving as a new transmission device, the substitute OXC (5o2) operates as a substitute for the new OXC (5o3) to communicate with the control device (20) until config setting necessary for the new OXC (5o3) is completed.

An optical antenna may permit a duplex link formed by a transmit, Tx, beam towards a partner optical antenna and a receive, Rx, beam from the partner antenna. The antenna includes: a proximal path including a bidirectional waveguide for duplex propagation of the duplex link from a Tx source of the Tx beam and towards a receiver of the Rx beam; a distal path for a duplex propagation of the duplex link from/towards the partner optical antenna; a beam shaper positioned in the distal path to shape a duplex propagation pattern of the duplex link; and a controller controlling the beam shaper to adaptively shape the propagation pattern to enclose: a first position of the partner antenna at the transmission of the Rx beam; and a second of the partner antenna at the reception of the Tx beam.

Systems and methods for alien wavelength management. One embodiment is an apparatus for managing alien wavelengths for a Wavelength Division Multiplexing (WDM) system. The apparatus includes memory to store signal thresholds for alien wavelength signals transmitting over the WDM system, wherein the alien wavelength signals are generated by third-party equipment independently controlled from the WDM system. The apparatus also includes an Alien Wavelength Control Unit (AWCU) coupled between the third-party equipment and a channelization port of the WDM system, the AWCU configured to measure a signal parameter of an alien wavelength signal transmitted by the third-party equipment to the channelization port. The apparatus further includes a controller coupled with the AWCU and configured, in response to determining that the signal parameter is outside a signal threshold of the WDM system, to direct the AWCU to modify the alien wavelength signal to protect the WDM system.

An active optical machine-readable tag (i.e. optical tag) is provided that is addressable and readable within a line-of-sight of a reader device, such as a mobile device equipped with a camera, at substantially large distances. A method and a system are provided for an active optical tag and a camera-based reader thereof that facilitate asynchronous communication at data rates that are sufficiently high for practical uses, while reducing the flicker associated with the low-frequency optical carrier to a level hardly noticeable by people. The optical tag may be formed as an array of light emitting elements, arranged in a single dimension (linear) or two dimension (planar) arrangement. The array may be embodied as part of a large display unit.

This disclosure relates to wavelength division multiplexed (WDM) passive optical networks (PON), and the transmission of point-to-point and broadcast or multicast channels from an optical line transmitter (OLT) to an optical network unit (ONU). There is provided a WDM PON (100) comprising: an OLT (105) coupled to a plurality of ONU (110a, 110b) using an optical fiber network (160); the OLT (105) having one or more WDM transceivers (115a, 115b) each arranged to receive multi-cast and point-to-point channels and wherein the or each WDM transceiver (115a, 115b) is arranged to transmit a said channel to a respective said ONU (110a, 110b) using a respective dedicated wavelength (λa, λb); an input channel switch (130a, 130b) associated with the or each WDM transceiver (115a, 115b) and arranged to selectively couple the input of the WDM transceiver to the multi-cast channels and the point-to-point channels (140,135); wherein the selected multi-cast or point-to-point channels are directly converted to the respective dedicated wavelength.

A method and an apparatus for self-calibration of an ONU receiver in a multi-wavelength PON system, said method including the initial physical layer scan of the receiver tuning range, distributed estimation of the down-stream wavelength channel drift with respect to the nominal standard-based wavelengths, and reporting the estimated downstream wavelength channel drift in the downstream Channel_Map message.