Methods and apparatus for providing enhanced optical networking service and performance which are particularly advantageous in terms of low cost and use of existing infrastructure, access control techniques, and components. In the exemplary embodiment, current widespread deployment and associated low cost of Ethernet-based systems are leveraged through use of an Ethernet CSMA/CD MAC in the optical domain on a passive optical network (PON) system. Additionally, local networking services are optionally provided to the network units on the PON since each local receiver can receive signals from all other users. An improved symmetric coupler arrangement provides the foregoing functionality at low cost. The improved system architecture also allows for fiber failure protection which is readily implemented at low cost and with minimal modification.

A Dual Parallel (DP)-Inphase/Quadrature (I/Q) Mach-Zehnder Modulator (MZM) bias controller configured to generate a pair of orthogonal dither signals; multiply the pair of dither signals to create a second order orthogonal dither signal; and lock an Inphase (I) I MZM of a DP-I/Q MZM to a value of a corresponding I component of a transmission signal by applying the pair of orthogonal dither signal to a Quadrature (Q) MZM and a Phase (P) MZM of the DP-I/Q MZM; applying an I bias signal to the I MZM of the DP-I/Q MZM; detecting an output of the DP-I/Q MZM; and determining an I error signal in the output of the I MZM of the DP-I/Q MZM based on the product of second order dither signal and the output of the DP-I/Q MZM.

A method implemented by a transmitter, comprising encoding digital in-phase and quadrature-phase (IQ) data associated with a plurality of analog signals according to a first multi-level modulation format to produce a modulated IQ signal, encoding control information associated with the plurality of analog signals according to a second multi-level modulation format that is different from the first multi-level modulation format to produce a modulated control signal, aggregating the modulated IQ signal and the modulated control signal via time-division multiplexing (TDM) to produce an aggregated TDM signal, and transmitting the aggregated TDM signal over a communication channel.

Methods and apparatus for providing enhanced optical networking service and performance which are particularly advantageous in terms of low cost and use of existing infrastructure, access control techniques, and components. In the exemplary embodiment, current widespread deployment and associated low cost of Ethernet-based systems are leveraged through use of an Ethernet CSMA/CD MAC in the optical domain on a passive optical network (PON) system. Additionally, local networking services are optionally provided to the network units on the PON since each local receiver can receive signals from all other users. An improved symmetric coupler arrangement provides the foregoing functionality at low cost. The improved system architecture also allows for fiber failure protection which is readily implemented at low cost and with minimal modification.

Disclosed is a system and method for using visible light communication (“VLC”) to perform indoor position location. Through use of a system and method configured as set forth herein, the position of any appropriately marked person or item may be found indoors using data interconnected modules that communicate with one another via RF and visible light. A mobile receiver in the form of a tag or badge attached to the person or item to be tracked receives a VLC signal from a plurality of lighting modules, and transmits back to a processor the data it received so that the processor is able determine the tag's or badge's physical position with respect to the individual network modules.

A method for detecting an optical network unit (ONU) in a passive optical network (PON), an ONU, a PON and an optical line terminal (OLT) are disclosed. In an embodiment the method include detecting an ONU identity code in an open uplink empty window or an empty timeslot, wherein the ONU identity code is a specific code stream sequence of the ONU that identifies a single ONU of the plurality of ONUs included in the PON system during the open uplink empty window or the empty timeslot and determining that the single ONU corresponding to the ONU identity code is a rogue ONU according to the ONU identity code.

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.

The present disclosure relates to communication methods, communications devices, and storage medium. In one example method, a port of a first device supports a flexible Ethernet protocol and a standard Ethernet protocol, and a protocol type supported by a port of a second device includes at least one of the flexible Ethernet protocol or the standard Ethernet protocol. The first device obtains the protocol type supported by the port of the second device, determines a target protocol type based on the protocol type supported by the port of the second device and a protocol type supported by the port of the first device, and communicates with the second device based on the target protocol type. The target protocol type includes the flexible Ethernet protocol or the standard Ethernet protocol.

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.

Disclosed are an optical-time-division-multiplexed transmission method and system using a simple sinusoidally modulated optical signal as an input pulse source. An optical-time-division-multiplexed transmission system comprises: an optical-time-division-multiplexed transmitter by applying a sinusoidal electrical signal, a first multi-level electrical PAM signal, and a second multi-level electrical PAM signal so as to generate an optical-time-division-multiplexed multi-level PAM signal; an optical detector for converting the transmitted optical-time-division-multiplexed PAM signal into an electrical signal; a time-division-demultiplexer for demultiplexing the detected electrical signal into two signals; a MIMO equalizer; and two decision elements for determining the levels of two demultiplexed signals obtained from the MIMO equalizer.