In some embodiments, an apparatus includes a first optical transceiver. The first optical transceiver includes a set of optical transmitters, an optical multiplexer operatively coupled to the set of optical transmitters, and a variable optical attenuator operatively coupled to the optical multiplexer. The variable optical attenuator is configured to receive a control signal from a controller of the first optical transceiver and modulate a signal representing control information with an output from the optical multiplexer. The control information is associated with the control signal and for a second optical transceiver operatively coupled to the first optical transceiver.

The present invention discloses a passive optical network communications method: reporting, by an optical network unit, ONU, a calibration record of the ONU, where the calibration record includes an ID of a calibrated wavelength channel; sending a first message to the ONU when the OLT determines, according to the calibration record, that a target wavelength channel ID corresponding to a target wavelength channel to which the ONU needs to switch is not in the calibration record, where the first message includes a forced wavelength switching flag; and instructing the ONU to switch to the calibrated target wavelength channel. In this way, the ONU can implement wavelength switching quickly after calibrating a new wavelength channel so as to perform data communication over the calibrated new wavelength channel.

A method of local path protection in a node on a shared alternative path of a network. The method comprising receiving a signal switched on a primary label switched path (LSP). The signal is switched by lambda-switching or time-division multiplex TDM switching. The method further comprises receiving identification information arranged to identify the signal, and forwarding the signal on the alternative path based on the identification information.

Embodiments of the invention disclose a communication method which includes: receiving, by the optical network unit (ONU) by using the first port or the second port, a wavelength switching request message delivered by the optical line terminal (OLT), where the wavelength switching request message carries second wavelength channel information and port information that is of the second port; switching, by the ONU, an operating wavelength channel of an optical module connected to the second port from a first wavelength channel to a second wavelength channel corresponding to the second wavelength channel information; and sending, by the ONU, a wavelength switching complete message to the OLT by using the first port. According to the communication method provided in embodiments of the present invention, quick wavelength switching is performed based on the second port, so that a service is not interrupted in a wavelength switching process, and user experience is better.

A photonic frame switching system may include a main controller and at least one photonic frame wrapper line card. The main controller may determine a point in time at which a photonic frame wrapper line card transmits a photonic frame by allocating a time slot to the photonic frame wrapper line card. When the photonic frame switching system includes a plurality of photonic frame wrapper line cards, points in times at which the plurality of photonic frame wrapper line cards transmits the photonic frames may be synchronized. In particular, when a portion of the plurality of photonic frame wrapper line cards transmit a plurality of photonic frames having different destinations, points in times at which all of the plurality of photonic frame wrapper line cards transmits the photonic frames may be adjusted based on a latency by a destination change.

This application provides a port detection method, an optical network device, and a passive optical network system, to quickly and accurately detect a port connected to an ONU, and improve efficiency of determining the port connected to the ONU. The method includes: an optical line terminal sends optical signals corresponding to all of N wavelengths to at least one optical network unit, where the N wavelengths are different from each other, and N is a positive integer; the OLT receives optical power values that are of the optical signals corresponding to all of the N wavelengths and that are sent by a first ONU, where the first ONU is any one of the at least one ONU; and the OLT determines, bases on the optical power values of the optical signals corresponding to all of the N wavelengths, information about an optical splitter port corresponding to the first ONU.

A photonic frame switching system may include a main controller and at least one photonic frame wrapper line card. The main controller may determine a point in time at which a photonic frame wrapper line card transmits a photonic frame by allocating a time slot to the photonic frame wrapper line card. When the photonic frame switching system includes a plurality of photonic frame wrapper line cards, points in times at which the plurality of photonic frame wrapper line cards transmits the photonic frames may be synchronized. In particular, when a portion of the plurality of photonic frame wrapper line cards transmit a plurality of photonic frames having different destinations, points in times at to which all of the plurality of photonic frame wrapper line cards transmits the photonic frames may be adjusted based on a latency by a destination change.

A method for virtualizing an optical network, comprising: abstracting optical resource information corresponding to resources within the optical network, constructing a plurality of candidate paths for one or more optical reachability graph (ORG) node pairs, determining whether the candidate paths are optical reachable paths, and creating an ORG link between each ORG node pair when at least one optical reachable path exists for the ORG node pair, wherein linking the ORG node pairs creates an ORG. In another embodiment, a computer program product comprising executable instructions when executed by a processor causes a node to perform the following: determine an optical network's optical-electrical-optical (OEO) conversion capability, partition a plurality of service sites into one or more electrical reachability graph (ERG) nodes, determine a grooming capability for each ERG node, and construct a plurality of electrical-layer reach paths between the ERG nodes to form an ERG.

In some embodiments, an apparatus includes a first optical transceiver. The first optical transceiver includes a set of optical transmitters, an optical multiplexer operatively coupled to the set of optical transmitters, and a variable optical attenuator operatively coupled to the optical multiplexer. The variable optical attenuator is configured to receive a control signal from a controller of the first optical transceiver and modulate a signal representing control information with an output from the optical multiplexer. The control information is associated with the control signal and for a second optical transceiver operatively coupled to the first optical transceiver.

A method and apparatus for communications in a passive optical network (PON) system are provided. An optical line terminal (OLT) generates a PON downstream Physical Layer (PHY) frame comprising a downstream physical synchronization block (PSBd) that comprises a wavelength identification (ID) of at least one downstream wavelength of the plurality of downstream wavelengths. The OLT sends the PON PHY frame comprising the wavelength ID in the PSBd to ONU for confirming the at least one downstream wavelength.