Embodiments of this application provide a method and an apparatus for obtaining optical distribution network (ODN) logical topology information, a device, and a storage medium. The method includes: obtaining identification information of each first ONU that is connected to a first passive optical network (PON) port and whose optical path changes and feature data of the first ONU in a first time window, where the feature data includes receive optical power and/or an alarm event; obtaining, based on the feature data of each first ONU, a feature vector corresponding to each first ONU; and performing cluster analysis on the feature vector corresponding to each first ONU, to obtain topology information corresponding to the first PON port. ONU topology information is obtained by analyzing an ONU feature.

A monitoring control unit (22) of an OXC (20d) stores a management table (22a) in which pieces of information regarding a modulation mode, an FEC, and a frame mode of an optical signal are associated with each other, and sequentially changes the modulation mode, the FEC, and the frame mode according to the management table (22a) upon an LOS alert from a relay-side optical input/output unit (24) or an LOF alert from a DSP (25) being input thereto. Upon successfully receiving an appropriate optical signal according to the change, the monitoring control unit (22) acquires transmission source information included in the optical signal, and detects an occurrence of erroneous connection of an optical transmission line in an OXC (20g), which serves as a relay apparatus, when the acquired transmission source information indicates an optical cross-connect apparatus that is a transmission source different from an original transmission source.

The present disclosure provides a ranging method and a registration method for an optical network, an Optical Line Terminal (OLT), an Optical Network Unit (ONU), and an optical network system. An OLT groups ONUs controlled by the OLT according to receiving optical power values of the ONUs. The OLT allocates corresponding uplink bandwidths to the ONUs in different groups, the uplink bandwidths being used to send registration information by the ONUs to be registered.

Provided are a link establishment method and apparatus and a computer-readable storage medium. The link establishment method includes: exchanging optical link auto-negotiation information with a terminal device through an optical link auto-negotiation channel; and in a case where exchanging the optical link auto-negotiation information is finished, establishing at least one of a traffic data channel or an optical link auto-negotiation channel; where the optical link auto-negotiation channel is independent of the traffic data channel or the optical link auto-negotiation channel; and the optical link auto-negotiation information includes at least one of information about an operating wavelength channel of the terminal device, an enabled or disabled state of forward error correction with the terminal device, a forward error correction type with the terminal device, or an operating mode of the auxiliary management channel.

A method for transmitting a digital frame by an optical network unit in a digital communications network includes steps of arranging received data into a series of symbols, installing a primary cyclic prefix immediately preceding the series of symbols in time, and inserting individual ones of a plurality of secondary cyclic prefixes between each adjacent pair of symbols in the series of symbols. A length of each secondary cyclic prefix corresponds to a first duration shorter than an amount of time needed to turn on a laser of the optical network unit. The method further includes a step of providing to the optical network unit the digital frame. The digital frame includes the primary cyclic prefix, the plurality of secondary cyclic prefixes, and the series of symbols. The method further includes a step of modulating the provided digital frame by a laser of the optical network unit.

The present disclosure relates to information transmission methods in a passive optical network (PON) system. One example method includes sending, by an optical line terminal (OLT), a first power range and time indication to an unregistered optical network unit (ONU), where the first power range and the time indication indicate the ONU to send a serial number of the ONU to the OLT at a time indicated by the time indication in case a downlink receive power of the ONU is within the first power range, and receiving, by the OLT, the serial number of the ONU.

An OLT includes a storage unit that stores management information indicating that a first address has been assigned to a client device that connects to an ONU as an operational system and an ONU as a standby system, a detection unit that detects occurrence of a failure to the ONU, a communication control unit that, connects to the ONU when the occurrence of the failure to the first slave station device is detected and controls communication performed by the client device so that the client device connects to the Internet via the ONU and the OLT, and a monitoring unit that monitors unauthorized use of the first address based on the management information both when the client device connects to the Internet via the ONU and the OLT and when the client device connects to the Internet via the ONU and the OLT.

Embodiments of this application provide a method and an apparatus for obtaining optical distribution network (ODN) logical topology information, a device, and a storage medium. The method includes: obtaining identification information of each first ONU that is connected to a first passive optical network (PON) port and whose optical path changes and feature data of the first ONU in a first time window, where the feature data includes receive optical power and/or an alarm event; obtaining, based on the feature data of each first ONU, a feature vector corresponding to each first ONU; and performing cluster analysis on the feature vector corresponding to each first ONU, to obtain topology information corresponding to the first PON port. ONU topology information is obtained by analyzing an ONU feature.

A status control method, applied to an optical network unit (ONU) or an optical network terminal (ONT) of a passive optical network (PON) includes: receiving a first downlink data frame, where the first downlink data frame includes data of N different rates and indication information, the indication information includes length information of data of each rate in the first downlink data frame, and N≥2; determining length information of first data in the data of the N different rates, where a rate of the first data is higher than a working rate of a clock and data recovery (CDR) module; and generating control information based on the length information of the first data, to control the CDR module to be in a specified state within a period of time corresponding to the length information of the first data.

A communication method, a device, and a system, the method including sending, by an optical line terminal (OLT) of a passive optical network that comprises the OLT and a plurality of optical network units (ONUs), a first downstream frame to the activated ONU using at least one downstream wavelength path, where the OLT and the at least one ONU of the plurality of ONUs communicate with each other using at the least one downstream wavelength path and a plurality of upstream wavelength paths, the plurality of ONUs comprises an activated ONU, wherein the first downstream frame comprises a first path identifier used to identify a first upstream wavelength path, and the first upstream wavelength path is one of the plurality of upstream wavelength paths, and receiving, by the OLT, upstream service data from the activated ONU using the first upstream wavelength path.