Abstract: A closed-form parametric approach to channel-estimation is provided. In one aspect, a specific parametric expression is presented for the received signal pdf that accurately models the behavior of the received signal in IM/DD optical channels. The corresponding parametric channel-estimation approach simplifies the design of MLSE receivers. The general technique lends itself well to the estimation of the signal pdf in situations where there are multiple sources of noise with different distributions, such as ASE noise, together with Gaussian and quantization noise, and signal-dependent noise, for example.

Abstract: In accordance with an embodiment of the present disclosure a method for adaptively spacing channels of an optical network comprises determining a first desired power level of a first channel of an optical network. The method further comprises determining a second desired power level of a second channel of the optical network, the second desired power level being less than the first desired power level. Additionally, the method comprises determining a first spectral space between the first channel and one or more channels neighboring the first channel based at least on the first desired power level. The method also comprises determining a second spectral space between the second channel and one or more channels neighboring the second channel based at least on the second desired power level, the second spectral space less than the first spectral space.

Abstract: A method for suppressing a skew between a first channel and a second channel in an optical transmission system having a transmitter that transmits an optical signal with the first channel and the second channel and a receiver that receives the optical signal, the method includes: controlling dispersion added to the optical signal to be larger than a specified amount; and controlling a delay time of at least one of the first channel and the second channel in the receiver based on a quality of the optical signal monitored in the receiver to suppress the skew between the first channel and the second channel in the receiver.

Abstract: A method reduces time-varying polarization crosstalk due to XPolM by transmitting multi-dimensional orthogonal constellations. Three variants of crosstalk-free constellations are provided: Grassmann constellations, unitary constellations, and rotation codes. The method uses the Grassmann constellations and the unitary constellations to deal with fiber nonlinearity by applying as a polarization-time coding. The rotation codes exploit a fiber channel characteristic to improve performance and to reduce computational complexity. The underlying orthogonality behind those constellations enables the receiver to decode it as if there is no polarization crosstalk. Moreover, the required computational complexity at the receiver is significantly reduced because neither crosstalk cancellers nor channel estimators are needed.

Abstract: In accordance with embodiments of the present disclosure, a method may include determining individual spectrum requirements for each of a plurality of signals to be communicated in an optical network, wherein a first signal of the plurality of signals has a first spectrum requirement and a second signal of the plurality of signals has a second spectrum requirement. The method may also include calculating a minimum spectrum granularity based on the individual spectrum requirements. The method may further include assigning each particular signal a channel spectrum equal to an integer multiple of the minimum spectrum granularity.

Abstract: A technique for monitoring at least a network portion of an optical communication network, by monitoring changes of a decision threshold used for discriminating a digital optical signal being propagated via the network portion.

Abstract: A system and method is disclosed that allows for the monitoring, analyzing and reporting on performance, availability and quality of optical network paths. The correlation of PM parameter metrics to client connections, coupled with threshold-based alarm generation provides a proactive and predictive management, reporting and analyzing of the health and effectiveness of individual path connections to alert Operational Support (OS) staff and/or customers to signal degradation and impending Network Element (NE) failures. The system and method performs in real-time processing intervals required for alarm surveillance in a telecommunications network.

Abstract: An optical communication apparatus that includes multiple optically communicative components positioned optically in series. Some of the optically communicative components may be optical fiber segments of perhaps different types. The optical channel represented by the series of optically communicative components and approximates a transfer function of an optical channel of a longer optical fiber. Accordingly, rather than deal with a lengthy optical fiber, an apparatus having a shorter optical channel may be used instead. The construction of the optical communicative components may be calculating an input transfer function. The construction would include an ordering of discrete optically communicative components that, when placed optically in series, simulates an estimation of a particular transfer function. Testing may then occur by actually passing an optical signal through the series construction of optically communicative components, rather than through the longer optical fiber.

Abstract: A communication apparatus with transmitted rate detecting function and the method therefore is provided. The communication apparatus receives an input signal transmitted at a first rate or a second rate from a remote apparatus. The method includes setting the communication apparatus to operate at an initial receiving rate; sampling the input signal by a specific sampling frequency to generate a sample result; estimating the input transmitted rate of the input signal according to the sample result so as to set the receiving rate of the communication apparatus at a working rate; and communicating with the remote apparatus at the working rate. The second rate is higher than the first rate, and the specific sampling frequency is associated with the initial receiving rate.

Abstract: An OPU frame generating device includes a frequency setting unit that sets a frequency corresponding to a bit rate of data which can be stored in a payload area, a parameter calculating unit that calculates a parameter Cm indicating an integer part of the amount of data included in the payload area using the set frequency, a data inserting unit that outputs a timing signal determined by the parameter Cm and inserts data at a position determined by the parameter Cm in the payload area, a data generating unit that generates data in synchronization with the timing signal, and a frame generating unit that generates an OPU frame having the payload area into which the data is inserted.

Abstract: An optical correlation apparatus is described which forms first and second parallel optical signals in response to a serial input data stream. The first parallel optical signal is arranged to have bright pulses represent binary 1 and the second parallel optical signal is arranged to have bright pulses represent binary 0. A channel select means, such as an optical switch or amplitude modulator, deselects or blocks channels in the first parallel optical signal which correspond to binary 1 in a reference data string and also deselects or blocks channels in the second parallel optical signal which correspond to binary 0 in the reference data string. The remaining optical signals are combined at one or more detectors. Where the input data matches the reference data string each bright pulse in the first and second parallel optical signals is deselected and the detector registers zero intensity. However when there is any mismatch at least one channel will pass a bright pulse to the detector.

Abstract: A transmitter (1) which transmits a predetermined amount of transfer data using an infrared ray includes: a controller (13) for transmitting an SNRM command to the other station without transmitting a station-search command (XID) for searching the other station, the SNRM command including parameters such as maximum transferable speed and maximum receivable data length of the transmitter (1); and a transmission section (14). Consequently, it is possible to shorten a time necessary for a connection between the transmitter and the receiver. This allows shortening a time from the start of communication to the end of the communication in transmitting information data.

Abstract: A light receiving circuit includes: a filter, arranged in a downstream of an electric signal amplifier to amplify an electric signal based on a light signal, to adjust a bandwidth of an amplified electric signal; a monitor circuit to monitor a communication quality of the light signal and output a monitored value; and a control circuit to control a bandwidth of the filter based on a control value corresponding to the monitored value.

Abstract: Consistent with the present disclosure, data, in digital form, is received by a transmit node of an optical communication system, and is then provided to a modulator that, in turn, modulates light, received from an optical source at one of a plurality of periodically and preferably minimally spaced wavelengths. The plurality of periodically spaced wavelengths or carriers are grouped together with minimal carrier spacing, to form a superchannel. The carrier spacing between adjacent carriers is determined by detecting a beat frequency of a combined optical signal that includes the outputs of two adjacent optical sources. The beat frequency corresponds to a frequency difference between the outputs of the adjacent carriers. This frequency difference should correspond to a desired carrier spacing between each of the plurality of carriers.

Abstract: Patterns detected by a low-speed receiver at the output of a high-speed multiplexer are used to determine when multiplexer input lanes are deskewed.

Abstract: Methods, algorithms, architectures, circuits, and/or systems for determining the status of parameters associated with optical transceiver operation are disclosed. The optical transceiver can include an optical receiver to receive optical data; an optical transmitter to transmit optical data; one or more memories to store data (and, optionally, thresholds) for each of a plurality of parameters that are related to operation of at least one of the optical receiver and the optical transmitter; a microprocessor that compares the parametric data against the threshold(s) to calculate one or more flags to indicate whether a corresponding parameter has exceeded the first or second threshold; and an interface that receives a flag request from a host, and provides the one or more flags in response to the request. In the present disclosure, the microprocessor may calculate the one or more flags only in response to the flag request from the host.

Abstract: Systems and methods to reduce passband side-lobes associated with WSS-based ROADMs by applying a filter on each channel are provided. In an exemplary embodiment, a comb filter, such as a thin film filter or an interleaver, is utilized. Additionally, the present invention provides systems and methods to adaptively control amplifier target power and per wavelength target power to maintain signal launching power as per design in networks with WSS-based ROADMs. Accordingly, signal OSNR does not collapse faster than other similar configured system without WSS-based ROADM. In order to correct amplifier target power, the present invention utilizes system information about side-lobe size and OSNR at each amplifier.

Abstract: The differential group delay is measured in an optical fiber connection for an optical signal undergoing a phase modulation BPSK or DPSK by a digital signal at a given rate. A polarization controller at an emerging end of the connection scans polarization states of the modulated optical signal. An emulator iteratively introduces an additional delay in the modulated optical signal emerging from the connection and combines the delayed modulated optical signal and the non delayed modulated optical signal which are both polarized along two orthogonal axes into a resulting optical signal. A polarization controller and a fixed polarizer select a polarization state in the resulting optical signal along one of bisecting lines of the orthogonal axes into a linearly polarized signal. An eye diagram or a spectrum of the polarized signal is acquired by a digital oscilloscope or an optical spectrum analyzer to determine the differential group delay.

Abstract: One example embodiment includes a testing device. The testing device comprises a signal reception element, an out-of-band detector and testing logic. The signal reception element is configured to receive a physical layer signal from a communication module via a physical link and to produce an incoming double modulated signal, the incoming double modulated signal including a high-speed data signal and an out-of-band data signal. The out-of-band data signal comprises diagnostic data of the communication module. The out-of-band detector is coupled to the signal reception element and is configured to extract the out-of-band data signal from the incoming double modulated signal. The testing logic is coupled to the out-of-band detector and is configured to extract and analyze the diagnostic data from the out-of-band data signal.

Abstract: Communication devices, systems, and methods for dynamic cell bonding (DCB) for Radio-over-Fiber (RoF)-based networks and communication systems are disclosed. In one embodiment, a method of operating an optical fiber-based wireless communication system is provided. The method includes determining a first plurality of remote units in a cloud bonded to a Radio-over-Fiber (RoF) communication session. The method also includes measuring a received signal strength from each of the first plurality of remote units. The method also includes measuring a received signal strength from each of a second plurality of remote units in the cloud not bonded to the RoF communication session. At least one of the second plurality of remote units is dynamically bonded to the RoF communication session if the measured received signal strength of the one of the second plurality of remote units is greater than the measured received signal strength of the first plurality of remote units.

Abstract: Methods and apparatus for varying the transmission rate of a signal transmitted within a dense wavelength division multiplexing (DWDM) system or network are disclosed. According to one aspect of the present invention, a method includes obtaining a first signal and determining a transmission rate associated with the first. If it is determined that the transmission rate is a first rate, the method includes processing the first signal as having a first transmission format and the first rate. Alternatively, it is determined that the transmission rate is not the first rate and is a second rate, the method includes processing the first signal as having a second transmission format and a second rate.

Abstract: A method for determining a value of chromatic dispersion compensation in an optical network including a plurality of nodes connected by at least one transmission line, the plurality of nodes including a plurality of dispersion compensators, the optical network including a plurality of wavelength paths between the optional nodes, the method includes determining a compensation value of the dispersion compensators in the optical network by the computer, the compensation value selecting that an error between the object value of the residual chromatic dispersion in accordance with of the first end node of the first path and the permissible value of the residual chromatic dispersion of the first end node of the first path is least, and the value of the residual chromatic dispersion of the first end is in the permissible value of the residual chromatic dispersion of the second end node of the second path.

Abstract: An optical communication base station which receives an upstream optical signal having an upstream bit rate specific to each one of a plurality of lower order communication units from a corresponding one of the plurality of lower order communication units, and which transmits a downstream optical signal having a downstream bit rate specific to each one of the plurality of lower order communication units to a designated one of the plurality of lower order communication units, includes; a first optical signal conversion unit which changes the bit rate of the upstream optical signal and thereby converts the upstream optical signal into a fixed bit-rate inter-station optical signal; and a second optical signal conversion unit which converts the inter-station optical signal into the downstream optical signal by changing the bit rate of the inter-station optical signal according to the designated one of the plurality of lower order communication units.

Abstract: A method for estimating a parameter includes: generating an optical signal, the optical signal modulated via a modulation signal having a variable modulation frequency over a period of time; transmitting the modulated optical signal from a light source into an optical fiber, the optical fiber including at least one sensing location configured to reflect light; receiving a reflected signal including light reflected from the at least one sensing location; and demodulating the reflected signal with a reference signal, the reference signal including a time delay relative to the modulation signal based on a distance between the light source and the at least one sensing location.

Abstract: The sender and the receiver prepare two photons in the entangled state of polarization. The first photon of the two photons is sent to the sender and the second photon of the two photons is sent to the receiver. The sender measures the first photon after the first photon pass the polarizer in which the vertical polarized photon can pass, when the sender sends the signal “1”. The sender measures the first photon after the first photon pass the polarizer in which the 45 degrees polarized photon can pass, when the sender sends the signal “0”. The receiver measures the second photon by the balanced homodyne measurement. And, the receiver knows the signal from the absolute value of the result of the balanced homodyne measurement.

Abstract: Described herein are systems and methods for accurately estimating and removing a carrier frequency offset. One exemplary embodiment relates to a system comprising a frequency offset detection circuit detecting a carrier frequency offset in an optical signal, and a frequency testing circuit calculating an estimated frequency offset value of the carrier frequency offset, wherein the frequency testing circuit removes a carrier phase based on the estimated frequency offset value and recovers the optical signal. Another exemplary embodiment relates to a method comprising detecting a carrier frequency offset in an optical signal, calculating an estimated frequency offset value of the carrier frequency offset, removing a carrier phase based on the estimated frequency offset value, and recovering the optical signal.

Abstract: In accordance with the present disclosure, disadvantages and problems associated with polarization dependent effects of a polarization multiplexed optical signal may be reduced through polarization scrambling. In accordance with an embodiment of the present disclosure a method for detecting polarization scrambling of a polarization multiplexed optical signal comprises receiving a polarization multiplexed optical signal associated with an optical network. The polarization multiplexed optical signal including a scrambled polarization orientation, the polarization orientation scrambled according to a scrambling frequency. The method further comprising receiving a polarization signal indicating the polarization scrambling of the received optical signal. The method additionally comprises descrambling the optical signal according to the polarization scrambling as indicated by the polarization signal.

Abstract: The invention relates to a method in a border node of an optical network and in an external optical channel originating apparatus and to a border node of an optical network and a router. The invention is particularly applicable to optical path validation in an optical network for an externally originating optical channel. The invention may be used during an optical path fault recovery operation. In the method in a border node of an optical network optical channel traffic parameter associated with an optical channel are received from an optical channel originator external to the optical network. The received optical channel traffic parameters are used to determine the suitability of at least one optical path within the optical network for an externally originating optical channel.

Abstract: an apparatus includes a first counter circuit that counts a value of first statistical information divided in the time-direction from a first period; a second counter circuit that counts a value of second statistical information divided in the time-direction from a second period following the first period; a control circuit that divides by a specific time period unit and acquires the value of the first statistical information and the value of the second statistical information, and causes a first memory to store the value of the first statistical information, and causes a second memory to store the value of the second statistical information; and a switching circuit that switches the value of the statistical information acquired by the control circuit from the value of the first statistical information to the value of the second statistical information upon a start of the second period.

Abstract: The first photon in single-photon state is divided into two components by the half beam splitter, and the first component is sent to the sender while the second component is sent to the receiver. The sender measures the first component of the first photon when he sends “1”. The sender doesn't measure the first component of the first photon when he sends “0”. The receiver makes the second component of the first photon enter into the Sagnac interferometer, and the receiver also makes the reference light enter into the Sagnac interferometer at the same time. The receiver makes the second component of the first photon interact with the reference light in the nonlinear optical medium arranged in the Sagnac interferometer. The receiver knows the signal from the phase modulation of the reference light caused by the interaction with the second component of the first photon.

Abstract: In a network design apparatus, a full channel evaluator determines whether all wavelength channels for main signals can deliver the main signals of an existing optical network. When it is found that one or more wavelength channels cannot deliver main signals, a chromatic dispersion evaluator determines whether there are a specified number of wavelength channels that satisfy a specified chromatic dispersion condition. An optical signal-to-noise ratio (SNR) evaluator extracts a specified number of wavelength channels out of those satisfying the chromatic dispersion condition in descending order of optical SNRs thereof, and determines whether the extracted wavelength channels satisfy a specified optical SNR condition.

Abstract: A computer system includes a main device and a subordinate device. Data transmission and reception by means of an optical transmission system are performed by connecting the main device and the subordinate device by an optical transmission cable. The subordinate device, a power of which needs to be cut-off prior to the main device, includes a light reception determination part and a power supply control part. The light reception determination part determines whether the main device is in a power-off state by presence or absence of light reception based on a light-receiving amount received by a photoelectric converter. When it is determined that the main device is in the power-off state, the power supply control part controls a power supply device so as to cut-off the power of the subordinate device.

Abstract: According to an aspect of an embodiment, an apparatus includes an optical branching unit for branching an input signal light in four directions, a polarization component extraction unit extracting four polarization components having mutually different polarization parameters from lights branched in four directions by the optical branching unit, and a determination unit determining input/non-input of the signal light based on the four polarization components extracted by the polarization component extraction unit.

Abstract: The present invention discloses a ranging method for an optical network unit in a passive optical network, which includes: an Optical Line Terminal (OLT) performing ranging for an Optical Network Unit (ONU) in a operation state, updating an Equalization Delay (EqD) of the ONU according to a ranging result, and sending the updated EqD to the ONU; and the ONU implementing an upstream transmission synchronization according to the updated EqD. The present invention further discloses a ranging system for an optical network unit (ONU) in a passive optical network (PON), which includes a ranging device and an equalization delay updating device. In the present invention, the influence on the interruption of services of the ONU for which ranging is performed is reduced, and the time-sensitive services of the ONU for which ranging is performed are protected, thus improving the upstream transmission efficiency of the ONU.

Abstract: There is provided a method of determining transmission quality of a path in an optical communication network system obtained by connecting a plurality of networks, the method including: acquiring a value representing transmission performance corresponding to a network condition of each of spans in the path in the optical communication network system; and determining the transmission quality of the path on the basis of the acquired value representing transmission performance corresponding to the network condition of each of spans.

Abstract: Even in a network system including a transmission line of which dominant cause of delay is a transmission line delay, controlling communication speed of the network system as a whole efficiently and suppressing the delay is made possible.

Abstract: A method and a device for monitoring and controlling a phase difference based on DQPSK modulation are provided, and the method includes: performing the nth power multiplication operation respectively on a first differential current signal and a second differential current signal output after DQPSK demodulation to correspondingly obtain a first monitor signal and a second monitor signal, where, n is a positive integral multiple of 4; monitoring phase differences between respectively two arms of a first demodulator according to the first monitor signal and two arms of a second demodulator according to the second monitor signal; adjusting the phase differences between respectively two arms of the first demodulator and two arms of the second demodulator using the monitor result, so that the differences can meet demodulation requirements and a receiver can obtain transmitted information.

Abstract: In an optical transmission system which utilizes polarization multiplexing, a receiver includes an adaptive equalizer which is adjusted at turn-up such that two polarization modes at the equalizer output are time aligned. The adaptive equalizer may be reset in a directed manner in response to an indication that one polarization mode is present at both the first and second outputs. Further, the dominant filters taps of the adaptive equalizer are maintained near a middle of a tap index range. The receiver may also include an interpolation function upstream of the adaptive equalizer and a symbol timing error estimation function that feeds a control signal back to the interpolation function, wherein the interpolation function causes the adaptive equalizer function and symbol timing error estimation function to receive an integer number of samples per symbol.

Abstract: A communication network access device is adapted for duplex communication and provides transmit and receive signal paths. A controllable socket is coupled to the transmit and receive signal paths and linked to a control interface for activating/deactivating the control interface. A pluggable module is coupled to the transmit and receive signal paths via the controllable socket in an activated status and to a transmission path carrying uni-directional signals. The module includes a first optical device and a splitter in the transmission path and is coupled to a second optical device via the splitter. The second optical device responds to a portion of uni-directional signals provided by the splitter for placing the communication access device in a link up condition for uni-directional signals provided by the first optical device to the transmission path serving an optical local area network.

Abstract: The path selection and wavelength assignment to a selected path are performed by mapping the wavelength reach to the demand distribution (agile reach) resulting in a 50-60% increase in the network reach. The network reach is further increased (about 2.2 times) when on-line measured performance data are used for path selection and wavelength assignment. The connections may be engineered/upgraded individually, by optimizing the parameters of the entire path or of a regenerator section of the respective path. The upgrades include changing the wavelength, adjusting the parameters of the regenerator section, controlling the launch powers, mapping a certain transmitter and/or receiver to the respective wavelength, selecting the wavelengths on a certain link so as to reduce cross-talk, increasing wavelength spacing, etc.

Abstract: In one exemplary embodiment, a method comprises transmitting an optical signal via the optical line, measuring a relative change in spectral intensity of the optical signal near a clock frequency (or half of that frequency) while varying a polarization of the optical signal between a first state of polarization and a second state of polarization, and using the relative change in spectral intensity of the optical signal to determine and correct the DGD of the optical line. Another method comprises splitting an optical signal traveling through the optical line into a first and second portions having a first and second principal states of polarization of the optical line, converting the first and second portions into a first and second electrical signals, delaying the second electrical signal to create a delayed electrical signal that compensates for a DGD of the optical line, and combining the delayed electrical signal with the first electrical signal to produce a fixed output electrical signal.

Abstract: A signal detection method used in an optical receiver apparatus detects the variation of an optical input level from the presence or absence of a clock signal and appropriately controls a dispersion compensator, thereby enabling the presence or absence of an input signal to be correctly determined. The signal detection method includes: detecting the level of input light of an optical amplifier, storing the level of the detected input light, comparing the level of the stored previous input light with the level of current input light, detecting the level variation of the input light by the comparison to detect the state change of the presence or absence of an optical signal, performing a dispersion compensation on the input light, and extracting a clock from an optical input. When the level variation of the input light is detected, the presence or absence of the optical signal of the input light is determined from the presence or absence of the clock signal.

Abstract: A method and a device are provided for processing data in an optical network. The method includes the steps of events of a login scan are recorded by a first optical network element; the events are conveyed to a second optical network element; and the events are processed by the second optical network element. A communication system is described that includes the device.

Abstract: The disclosure discloses a method for processing a Tandem Connection Monitoring (TCM) level, which comprises: obtaining a route of a service which needs to be configured TCM, obtaining a TCM segment on the route of the service, determining a TCM segment which needs to be configured from the obtained TCM segment, and allocating a TCM level for the TCM segment which needs to be configured according to a segment relationship between the TCM segment which needs to be configured and a configured TCM segment. The disclosure further discloses an apparatus for processing a TCM level. By means of the disclosure, a TCM level can be automatically allocated for a TCM segment and environment of multiple network applications can be applicable.

Abstract: The present relates to pluggable electronic unit with transmission power adjustment capability such as for example small form-factor pluggable transceivers. The pluggable electronic unit with transmission power adjustment capability may comprise a power adjustment unit. By verifying the transmitted power is sufficient or could be reduced, it is possible to regulate transmission power of a transceiver autonomously within the pluggable electronic unit itself.

Abstract: A receiver for a communications link includes a receiver module and a host receiver. These two components can be tested independently. In one embodiment, the receiver module is characterized with respect to noise and distortion. The noise performance can be determined by comparing input and output signals of the receiver module, to determine the relative noise of the receiver module. The distortion performance can be determined by comparing the distortion of input and output signals of the receiver module, using a reference host receiver that includes an equalizer. The host receiver can be tested by using a reference receiver module.

Abstract: A skew estimator for estimating a skew between a first signal of a first data path and a second signal of a second data path in a coherent receiver is provided. The skew estimator comprises a phase detector and an integrator. The phase detector is configured to detect a phase of the first signal or the second signal to obtain a phase signal. Further, the integrator is configured to integrate the obtained phase signal to provide an estimated skew.

Abstract: The present disclosure provides Network Element (NE) clock synchronization using Optical Transport Network (OTN) delay measurement systems and methods such as described in ITU-T G.709 (12/2009) “Interfaces for the Optical Transport Network (OTN)” and G.798 (10/2010) “Characteristics of optical transport network hierarchy equipment functional blocks”. OTN provides a Delay Measurement (DM) function to measure fiber path latency between two network elements to within microsecond accuracy. The convergence of packet switching and OTN transport into the same network element allows the sharing of this information between the two applications. The OTN delay measurement value can be used to synchronize two network element clocks to within microsecond accuracy without the need for a costly GPS synchronization solution or reduced accuracy NTP solutions.

Abstract: A method for managing upstream burst overhead parameters includes: an Optical Line Terminal (OLT) or an Optical Network Unit (ONU) detects transmission quality of a downlink between the OLT and the ONU; the OLT or the ONU determines the upstream burst overhead parameters suitable for the ONU according to the transmission quality; and the ONU starts to use the upstream burst overhead parameters suitable for the ONU after the switching time determined by the ONU itself or indicated by the OLT. The present invention also provides an ONU and an OLT for managing the upstream burst overhead parameters. The present invention can improve the bandwidth utilization rate and decrease the complexity of indicating the upstream burst overhead parameters in PON system, so that the ONU and the OLT are enabled to flexibly and simply select the upstream burst overhead parameters.

Abstract: The embodiments of the present invention disclose a system, a method, and a device for polarization multiplexing. The method includes: co-direction judgment: after judging that the similarity between the control quantities of the two optical signals meets a predetermined similarity criterion, enabling at least one of the two branches to re-search for the control quantity until the similarity between the control quantities of the two optical signals does not meet the predetermined similarity criterion. The preceding technical solution may substantially prevent the optical signals output by the two branches at a receiving end from having the co-directional state of polarization, without affecting the complexity and implementation cost of the system and the processing time delay of data signals at the receiving end.