Abstract: This application provides a data reassembly method and an apparatus, to reassemble packet fragments in combination with local reassembly and cloud reassembly, so as to obtain a reassembled packet. This improves reassembly efficiency, reduces a packet reassembly delay, and reduces power consumption of an OLT. The method includes: a first OLT receives a plurality of packet fragments of a first packet that are sent by an optical network unit ONU; and if the first OLT determines that an upload condition is met, the first OLT sends the plurality of packet fragments to a cloud reassembly device, so that after receiving the plurality of packet fragments, the cloud reassembly device reassembles the plurality of packet fragments to obtain a second packet.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: This application discloses a communication method, an optical line terminal, and an optical network unit in a passive optical network system. The PON system includes an OLT and at least one ONU, and the method includes: receiving, by the OLT, a first message that is sent by a first ONU in the at least one ONU through a first upstream channel; determining a first round trip time (RTT) of the first ONU based on a receiving moment of the first message; determining a time window based on the first RTT; sending first indication information to the first ONU through a downstream channel, where the first indication information includes the time window; receiving a second message that is sent by the first ONU through a second upstream channel within the time window; and determining a second RTT of the first ONU based on a receiving moment of the second message.

Abstract: This application discloses a communication method, an optical line terminal, and an optical network unit in a passive optical network system. The PON system includes an OLT and at least one ONU, and the method includes: receiving, by the OLT, a first message that is sent by a first ONU in the at least one ONU through a first upstream channel; determining a first round trip time (RTT) of the first ONU based on a receiving moment of the first message; determining a time window based on the first RTT; sending first indication information to the first ONU through a downstream channel, where the first indication information includes the time window; receiving a second message that is sent by the first ONU through a second upstream channel within the time window; and determining a second RTT of the first ONU based on a receiving moment of the second message.

Abstract: Embodiments of the present invention disclose a fiber recognition method, an optical line terminal, and a system. The method includes: obtaining, by an optical line terminal, identification information of a fiber connected to an optical line terminal and to be recognized; generating, by the optical line terminal, a data frame that includes the identification information of the fiber to be recognized; transmitting, by the optical line terminal, optical signals that are generated according to the data frame to the fiber to be recognized, so as to make a fiber recognition instrument implement identification for the fiber to be recognized. The present invention can implement fiber recognition easily and conveniently. When a new ONU user is added to a distributed network, service interruption can also be avoided for a user who is normally using a service, and the cost is low.

Abstract: 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.

Abstract: The present disclosure provides a data transmission method including: receiving a first-mode optical signal from a first port corresponding to a first port number; converting, according to a correspondence between the first port number and a first mode group number, the received first-mode optical signal into a second-mode optical signal carried in a first mode group identified by the first mode group number, where the second-mode optical signal carried in the first mode group identified by the first mode group number includes an optical signal in one or more modes; and outputting the second-mode optical signal obtained by means of conversion.

Abstract: The present disclosure provides a data transmission method including: receiving a first-mode optical signal from a first port corresponding to a first port number; converting, according to a correspondence between the first port number and a first mode group number, the received first-mode optical signal into a second-mode optical signal carried in a first mode group identified by the first mode group number, where the second-mode optical signal carried in the first mode group identified by the first mode group number includes an optical signal in one or more modes; and outputting the second-mode optical signal obtained by means of conversion.

Abstract: Embodiments disclose an OTDR implementation apparatus. The apparatus includes M transmitters, configured to transmit M optical waves of different wavelengths, where M is greater than or equal to 2. The apparatus also includes a processor, configured to control an OTDR detection circuit to load an OTDR detection signal onto a first transmitter, where the first transmitter is configured to only load the OTDR detection signal, and the other M?1 transmitters are configured to transmit a downlink optical signal, where the downlink optical signal is a high frequency signal. The apparatus also includes the OTDR detection circuit, configured to generate the OTDR detection signal, where the OTDR detection signal is a low frequency signal; and M receivers, where a first receiver is connected to an egress link of the M transmitters, and the other M?1 receivers are connected after a demultiplexer, and are configured to receive multiple uplink signals.

Abstract: The present disclosure discloses a data transmission method, an apparatus, and a system. The method includes: receiving, by a mode multiplexer from an input port, a first optical signal transmitted by an optical line terminal; converting, according to a correspondence between an input port of an optical signal and a mode of the optical signal, the received first optical signal into a second optical signal in a mode corresponding to the input port; and multiplexing the second optical signal obtained by means of conversion to a few-mode optical fiber for transmission. This increases transmission capacity of a single optical fiber and implements fast expansion of the transmission capacity, thereby improving total bandwidth utilization of a system.

Abstract: The present disclosure provides a data transmission method including: receiving a first-mode optical signal from a first port corresponding to a first port number; converting, according to a correspondence between the first port number and a first mode group number, the received first-mode optical signal into a second-mode optical signal carried in a first mode group identified by the first mode group number, where the second-mode optical signal carried in the first mode group identified by the first mode group number includes an optical signal in one or more modes; and outputting the second-mode optical signal obtained by means of conversion.

Abstract: Embodiments disclose an OTDR implementation apparatus. The apparatus includes M transmitters, configured to transmit M optical waves of different wavelengths, where M is greater than or equal to 2. The apparatus also includes a processor, configured to control an OTDR detection circuit to load an OTDR detection signal onto a first transmitter, where the first transmitter is configured to only load the OTDR detection signal, and the other M?1 transmitters are configured to transmit a downlink optical signal, where the downlink optical signal is a high frequency signal. The apparatus also includes the OTDR detection circuit, configured to generate the OTDR detection signal, where the OTDR detection signal is a low frequency signal; and M receivers, where a first receiver is connected to an egress link of the M transmitters, and the other M?1 receivers are connected after a demultiplexer, and are configured to receive multiple uplink signals.

Abstract: A passive optical network (PON) component comprising a power switch, a detector configured to monitor the power switch, and a processor configured to receive an interrupt from the detector and transmit a message comprising a first indicator that the PON component has powered down, and a second indicator giving a reason for the power down. A passive optical network (PON) component comprising a processor configured to implement a method comprising receiving an interrupt message from a detector, determining a reason for the interrupt, and transmitting a dying gasp message comprising an indicator of the reason for the interrupt. A method comprising transmitting an alarm message comprising an optical network terminal (ONT) manual power off indicator that indicates the ONT is shutting down because a subscriber has turned off its power switch.

Abstract: Embodiments of the present invention disclose a fiber recognition method, an optical line terminal, and a system. The method includes: obtaining, by an optical line terminal, identification information of a fiber connected to an optical line terminal and to be recognized; generating, by the optical line terminal, a data frame that includes the identification information of the fiber to be recognized; transmitting, by the optical line terminal, optical signals that are generated according to the data frame to the fiber to be recognized, so as to make a fiber recognition instrument implement identification for the fiber to be recognized. The present invention can implement fiber recognition easily and conveniently. When a new ONU user is added to a distributed network, service interruption can also be avoided for a user who is normally using a service, and the cost is low.

Abstract: Embodiments of the present disclosure describe a method and an apparatus for testing an optical network, which may be applicable to an integrated OTDR and the field of optical network technologies. The method includes obtaining a maximum test time of a single group test; dividing a total test time into at least two groups of single group test time that is not greater than the maximum test time when the total test time is greater than the maximum test time of the single group test; performing the single group tests in sequence according to each single group test time; and instructing optical network equipment to restore to a normal working state when the single group test time corresponding to each single group test ends.

Abstract: The present disclosure provides a time synchronization method, including: acquiring, by a slave device, a first optical fiber transmission delay from a master device to the slave device, and a second optical fiber transmission delay from the slave device to the master device; exchanging a time synchronization signal with the master device, and calculating an initial time offset; adjusting the initial time offset by using the first optical fiber transmission delay and the second optical fiber transmission delay to obtain a corrected time offset; and adjusting a local clock according to the corrected time offset. Embodiments of the present disclosure further provide a corresponding device and system.

Abstract: A method for measuring an optical power includes: acquiring code type information in an optical signal of a communication system, in which the optical signal includes an optical signal of burst emission and/or an optical signal of burst reception; measuring the optical signal of the communication system, and acquiring an optical power value of the optical signal; and correcting the optical power value according to the code type information.

Abstract: Embodiments of the present disclosure describe a method and an apparatus for testing an optical network, which may be applicable to an integrated OTDR and the field of optical network technologies. The method includes obtaining a maximum test time of a single group test; dividing a total test time into at least two groups of single group test time that is not greater than the maximum test time when the total test time is greater than the maximum test time of the single group test; performing the single group tests in sequence according to each single group test time; and instructing optical network equipment to restore to a normal working state when the single group test time corresponding to each single group test ends.