The present disclosure relates to passive optical network (PON) systems, an optical line terminal (OLT), and an optical network unit (ONU). One example PON system includes an OLT and at least two ONUs, and the OLT and the ONUs exchange data on one downstream channel and two upstream channels. The OLT sends downstream data to each ONU on the downstream channel, where the downstream data includes an upstream bandwidth grant which is used to control the ONU to send upstream data. Each ONU receives the downstream data on the downstream channel, and sends the upstream data on a first upstream channel or a second upstream channel based on the upstream bandwidth grant included in the downstream data. The OLT receives, on the first upstream channel and the second upstream channel, the upstream data sent by each ONU.

The present disclosure relates to passive optical network (PON) systems, optical line terminals (OTLs), and optical network units (ONUs). One example PON system includes an OLT and at least two ONUs. The OLT and the ONUs exchange data on one downstream channel and two upstream channels. The OLT sends downstream data to each ONU on the downstream channel, where the downstream data includes an upstream bandwidth grant used to control each ONU to send upstream data. Each ONU receives the downstream data on the downstream channel, and sends the upstream data on a first upstream channel or a second upstream channel based on the upstream bandwidth grant included in the downstream data. The OLT receives, on the first upstream channel and the second upstream channel, the upstream data sent by each ONU, where a registration function is disabled on the first upstream channel, and enabled on the second upstream channel.

A method and an apparatus for compensating for wavelength drift are disclosed. The method includes: generating, by a burst control circuit, a burst bias current; sending, by the burst control circuit, the burst bias current to a light emitting part and a trigger; converting, by the trigger, the received burst bias current into burst DA data; sending, by the trigger, the burst DA data to a synthesizer circuit; receiving, by the synthesizer circuit, the burst DA data sent by the trigger and the calibrated DA data sent by the MCU respectively; synthesizing, by the synthesizer circuit, the burst DA data and the calibrated DA data to obtain a synthesized signal; and sending, by the synthesizer circuit, the synthesized signal to a temperature control part.

A method of communication includes receiving, by an optical line terminal (OLT), a registration request from an optical network unit (ONU) through a specific upstream wavelength, assigning, by the OLT, out of a plurality of normal service upstream wavelengths and a plurality of normal service downstream wavelengths in a wavelength resource pool, a normal service upstream wavelength and a normal service downstream wavelength to the ONU for a normal service between the ONU and the OLT, and informing, through a specific downstream wavelength, the ONU of information regarding the normal service upstream wavelength and the normal service downstream wavelength. The specific downstream and upstream wavelengths are reserved for a registration process that includes receiving, through the specific upstream wavelength, the registration request and sending, through the specific downstream wavelength, the information regarding the normal service upstream wavelength and the normal service downstream wavelength.

A method of communication includes receiving, by an optical line terminal (OLT), a registration request from an optical network unit (ONU) through a specific upstream wavelength, assigning, by the OLT, out of a plurality of normal service upstream wavelengths and a plurality of normal service downstream wavelengths in a wavelength resource pool, a normal service upstream wavelength and a normal service downstream wavelength to the ONU for a normal service between the ONU and the OLT, and informing, through a specific downstream wavelength, the ONU of information regarding the normal service upstream wavelength and the normal service downstream wavelength. The specific downstream and upstream wavelengths are reserved for a registration process that includes receiving, through the specific upstream wavelength, the registration request and sending, through the specific downstream wavelength, the information regarding the normal service upstream wavelength and the normal service downstream wavelength.

A full duplex communication network includes an optical transmitter end having a first coherent optics transceiver, an optical receiver end having a second coherent optics transceiver, and an optical transport medium operably coupling the first coherent optics transceiver to the second coherent optics transceiver. The first coherent optics transceiver is configured to simultaneously transmit a downstream optical signal and receive an upstream optical signal. The second coherent optics transceiver is configured to simultaneously receive the downstream optical signal from the first coherent optics transceiver and transmit the upstream optical signal first coherent optics transceiver. At least one of the downstream optical signal and the upstream optical signal includes at least one coherent optical carrier and at least one non-coherent optical carrier.

The present disclosure relates to passive optical network (PON) systems, optical line terminals (OTLs), and optical network units (ONUs). One example PON system includes an OLT and at least two ONUs. The OLT and the ONUs exchange data on one downstream channel and two upstream channels. The OLT sends downstream data to each ONU on the downstream channel, where the downstream data includes an upstream bandwidth grant used to control each ONU to send upstream data. Each ONU receives the downstream data on the downstream channel, and sends the upstream data on a first upstream channel or a second upstream channel based on the upstream bandwidth grant included in the downstream data. The OLT receives, on the first upstream channel and the second upstream channel, the upstream data sent by each ONU, where a registration function is disabled on the first upstream channel, and enabled on the second upstream channel.

A method and an apparatus for compensating for wavelength drift are disclosed. The method includes: generating, by a burst control circuit, a burst bias current; sending, by the burst control circuit, the burst bias current to a light emitting part and a trigger; converting, by the trigger, the received burst bias current into burst DA data; sending, by the trigger, the burst DA data to a synthesizer circuit; receiving, by the synthesizer circuit, the burst DA data sent by the trigger and the calibrated DA data sent by the MCU respectively; synthesizing, by the synthesizer circuit, the burst DA data and the calibrated DA data to obtain a synthesized signal; and sending, by the synthesizer circuit, the synthesized signal to a temperature control part.

A circuit board of the optical module comprises: a first electrical interface is configured to connect an electrical interface of a board or a second electrical interface of another optical module, and a second electrical interface is configured to connect a first electrical interface of another optical module; a first optical port is configured to connect an optical transmission device or a second optical port of another optical module, and a second optical port is configured to connect an optical receiving device or a first optical port of another optical module; and a optical transceiver assembly multiplexes downstream light and demultiplexes upstream light. The optical module provided in solutions of the present invention can be flexibly combined with another optical module, enabling flexible and gradual upgrade of an optical module bandwidth according to a user requirement by using various combination manners.

A communication method, apparatus, and system for a passive optical network (PON). The PON includes an optical line terminal (OLT) and a first optical network unit (ONU), where the method includes communicating, by the OLT, with the first ONU using one downlink wavelength (?dx), where the ?dx is any one of N downlink wavelengths ?d1 to ?dN, and communicating, by the OLT, with the first ONU using one uplink wavelength (?u0), where the ?u0 is different from any one of M uplink wavelengths ?u1 to ?uM. The N downlink wavelengths ?d1 to ?dN and the M uplink wavelengths ?u1 to ?uM are wavelength values configured for a second ONU, N and M are both integers greater than or equal to 2, and x is any value from 1 to M. Therefore, complexity and costs of the PON system are reduced.