Abstract: An electroabsorption optical modulator used as a sampling element has two optical terminals and a power supply terminal, the two optical terminals are used to input and output light, and the power supply terminal imparts an electric field to an optical path connecting the two optical terminals. The electroabsorption optical modulator has a characteristic in which an absorption index is changed with respect to the light beam propagating through the optical path according to a level of the electric field. A monitoring (synchronization sampling) object optical signal is input into one of the two optical terminals of the electroabsorption optical modulator. A predetermined direct-current voltage exhibiting a high absorption index for the monitoring (synchronization sampling) object optical signal is imparted to the power supply terminal of the electroabsorption optical modulator.

Abstract: The invention relates to a method for determining and/or evaluating a differential, optical signal. According to the invention, at least two first light sources (S1, S2) which are sequentially clocked in terms of light and emitted in a phased manner are provided, in addition to at least one receiver (E) which is used to receive at least the alternating light portion arising from the first light sources (S1, S2). The light intensity radiating through at least one light source (S1, S2) in the measuring arrangement is controlled in such a manner that the clock synchronous alternating light portion, which occurs between different phases, is zero in the receiver (E). By determining the reception signal in the receiver (E) in relation to the phase position in order to regulate the radiated light intensity and by producing an adjustable variable (R) directly or by adding current in the receiver, it is possible to simplify digital implementation of the method with as little sensitivity loss as possible.

Abstract: An optical reflector, an optical multiplexer/demultiplexer device and an optical system which can allow more flexible arrangement of an optical filter thereof, and enhance performance of wavelength division multiplexing communication thereof are provided. An optical reflector according to the present invention comprises a first and second optical fiber 14, 16, each being connected to one side of an optical propagating region such as a rod lens 12 causing optical strength distributions depending on respective wavelengths of lights to be propagated in the optical propagating region; a mirror 18 disposed on the other side of the optical propagating region; and an optical filter 20 disposed between the first and second optical fibers 14, 16 and the mirror 18.

Abstract: An apparatus and method for extracting an optical clock signal are provided. The apparatus includes a first reflection filter selecting and reflecting only a first frequency component in an input optical signal; a first Fabry-Perot laser diode matching the first frequency component reflected by the first reflection filter with a predetermined output mode and outputting the first frequency component in the predetermined output mode; a second Fabry-Perot laser diode selecting a second frequency component in an input optical signal that has not been reflected but has been transmitted by the first reflection filter, matching the second frequency component with a predetermined output mode, and outputting the second frequency component in the predetermined output mode; and a photodetector receiving the first frequency component from the first Fabry-Perot laser diode and the second frequency component from the second Fabry-Perot laser diode and beating them to extract a clock signal.

Abstract: In a telecommunication system, channels of information are modulated onto respective carriers that are swept repeatedly across a frequency range in a time-staggered fashion so that, at any one time each carrier is at a different frequency. The carriers are multiplexed onto a single communications link and separated, on reception, by filters swept in synchronism so as to de-multiplex the signals.

Abstract: A transceiver module having intergrated eye diagram opening functionality for reducing jitter is describe. The transceiver module may transmitter eye opener and a receiver eye opener integrated in a single circuit. The transceiver module may also include serial control and various other integrated components. Other functionalities that may be integrated on the transceiver module include loopback modes, bypass features, bit error rate testing, and power down mode.

Abstract: A method and system is disclosed for making timing alignment for a data transmission system, the method comprising providing a reference clock signal with a first frequency to a multiplexer through a phase shifter, generating a multiplexed signal with a second frequency by the multiplexer, wherein the second frequency follows the first frequency and is higher than the first frequency by a predetermined proportion, sending the multiplexed signal to a modulator, and phase shifting the reference clock signal by the phase shifter before the reference clock signal is provided to the multiplexer, wherein a timing of the multiplexed signal at the second frequency level can be adjusted by adjusting a timing of the reference clock signal at the lower first frequency level.

Abstract: A system and method of transmitting client data encoded according to an 8B/10B encoding between a client side and an optical communication network side, including inserting padding signals in an amount corresponding to a rate difference between a clock on the client side and a clock in the optical transmission device and controlling a clock to be used as a reference in transmitting the client data to synchronize with a clock having been used as a reference in transmitting the client data on the basis of a ratio of padding signals having been inserted in the client data.

Abstract: A fiber optical system (10) for transmitting an optical signal comprises an optical fiber line (1) with a plurality of successively arranged polarization scramblers (6a to 6c) for polarization modulation of the optical signal transmitted through the optical fiber line (1) and a reference frequency signal (11) which synchronizes scrambling frequencies of all of the polarization scramblers (6a to 6c) to a common reference frequency.

Abstract: A method and system for scanning a multiple light beam system, such as a safety light curtain, uses a plurality of transmission signals including two or more synchronization signals for synchronizing a beam receiver module with a beam transmission module. The system has transmitter circuitry which generates the transmission signals for driving light sources of the transmission module and receiver circuitry which receives corresponding transmitted signals. The receiver circuitry generates a scanning initialization signal using an uninterrupted synchronization signal among the reception signals for synchronizing the receiver module with the transmission module and scans the receiver module in response to generation of the scanning initialization signal.

Abstract: When entering an idling state, a master unit M transmits an optical signal for polling addressed to each slave unit S-1 to S-n. The slave unit S-n located at the lowest rank of a direct chain constituted by S-1 to S-n, when receiving the optical signal for polling for the self unit, responds by transmitting an optical signal representing a phase correction request signal to the other slave units. The slave units S-1 to S-(n?1) respond to the phase correction request signal, and initialize each clock signal to synchronize with the clock signal of the slave unit S-n at the lowest rank.

Abstract: A bit synchronization circuit comprising an initial phase determining unit for rapidly determining, during a period of receiving a preamble of burst data, a clock with a phase synchronized with received burst data from among multi-phase clocks having the same frequency as an internal reference clock and a phase tracking unit for modifying the synchronized phase clock responsive to phase variation of received data during a period of receiving a payload of burst data by taking the synchronized phase clock determined by the initial phase determining unit as an initial phase. The bit synchronization circuit retimes burst data with a data retiming clock having a predetermined phase relation with the synchronized phase clock and outputs the burst data in synchronization with the internal reference clock.

Abstract: System and method for data synchronization in Passive Optical Networks. According to an embodiment, the present invention provides a method for providing upstream data synchronization in an optical communication network. The method includes sending data from an Optical Network Unit. The data includes a first data frame, which includes a header sequence, a synchronization segment, and a data segment. The synchronization segment includes 66 bits, which includes a first number of bits having nonzero values and a second number of bits having a value of zero. The first number is different from the second number. The method further includes receiving at least the first data frame by an Optical Line Terminal. The method also includes processing the first data frame. The method additionally includes selecting a first segment of the first data frame, the first segment including 66 bits.

Abstract: A synchronous optical bus system for communication between computer system components is described. In one example, the optical bus system is used for communication between a memory controller and memory devices optically coupled to an optical interconnect. Optical bus interface units couple the components to the optical interconnect and are arranged on the optical interconnect in order that a sum of an optical path length from a controller component to each computer system component and from each computer system component to the controller component is the same for all the coupled computer system components. A synchronous protocol is used for communication between the components.

Abstract: A method of a conveying data through an optical communications system. An optical signal is received through the optical communication system, the optical signal comprising data symbols and SYNC bursts, each SYNC burst having a predetermined symbol sequence. The received optical signal is oversampled to generate a multi-bit sample stream. The sample stream is partitioned into blocks of contiguous samples, wherein each block of samples partially overlaps at least one other block of samples and encompasses at least one SYNC burst and a plurality of data symbols. Each block of samples is independently processed to detect a value of each data symbol.

Abstract: An optical signal regenerative repeater is provided including at least one first optical 3R repeater based on an optical communication signal pulse, regenerating the optical communication signal pulse. The first optical 3R repeater comprises a first clock extraction unit extracting a clock from the optical communication signal pulse and generating a first optical clock pulse synchronized with the extracted clock. The first optical 3R repeater also comprises a first optical gate, which is opened and closed in accordance with a control light corresponding to the optical communication signal pulse, which receives as a controlled light the first optical clock pulse generated by the first clock extraction unit, and which generates a first regenerated signal pulse corresponding to said optical communication signal pulse. Further, a pulse time width of the control light and the controlled light is different.

Abstract: A PPM transmitter includes an optical clock generator for generating equally-spaced optical pulses with a sampling period T; an encoder for transforming an incoming waveform U(t) into a linear combination V(t) of U(t) and a delayed output V(t?kT) according to a rule V(t)=a(U(t)+V(t?kT)), where k is a positive integer, V(t) is voltage generated by the encoder and a is a coefficient; and an optical delay generator for delaying optical pulses generated by the optical clock generator in proportion to the voltage V(t), such that ?tn=bV(t), where b is another coefficient and where ?tn is the amount of delay imposed by the optical delay generator. The PPM transmitter functions with a PPM receiver for communicating data without the need to transmit or otherwise provide a clock signal.

Abstract: A transmission device uses transmission delay time of reciprocation with the terminal and time information of the transmission device to create a correction value of time information of the terminal and transmits it to the terminal. The terminal includes expected arrival time information based on the time information of the terminal and the correction value received from the transmission device in a frame transmitted to the transmission device. The transmission device compares reception time of the frame with the expected arrival time information in the frame. If they match, the time information of the terminal synchronizes with the time information of the transmission device. If they do not match, the transmission device transmits a new correction value to the terminal. The terminal transmits a frame including expected arrival time information using the new correction value to the transmission device.

Abstract: Systems and methods for providing controlled impairments to an optical transport system are disclosed. In one implementation, an optical stream is received. A clock signal and a data signal are identified based on the received optical signal. A selection indicating at least a particular bit position of the optical stream to be modified is received from a user and it is determined whether the particular bit position of the optical stream is located in an active video portion, a horizontally ancillary data portion, a vertically ancillary data portion, a start-video timing portion, or an end active video portion of the optical stream. The particular bit position in the determined portion of the optical stream is identified based on at least the clock signal and the data signal, and the particular bit position of the optical stream is modified.

Abstract: A synchronous optical network (SONET) system having multi-hierarchal network service access point (NSAP) addressing includes electrically linked network elements (NEs) and first and second level routing areas which each include at least one NE. The NEs include devices having respective NSAP addresses and at least one of the NEs is a network controller that controls the SONET. The first level routing area and the second level routing areas are based on a predetermined prioritization of the NEs as first level NEs and second level NEs, and have a first level routing and having a second level routing for the NSAP addresses, respectively. Each NSAP address includes a Routing Domain field and an Area field filled with information indicative of a respective Internet Protocol (IP) address.

Abstract: A transceiver module having integrated eye diagram opening functionality for reducing jitter is described. The transceiver module may include a transmitter eye opener and a receiver eye opener integrated in a single circuit. The transceiver module may also include serial control and various other integrated components. Other functionalities that may be integrated on the transceiver module include loopback modes, bypass features, bit error rate testing, and power down modes.

Abstract: A receiver (10) for an optical signal containing a time jitter and a time-varying distortion caused by a periodic polarization scrambled signal comprises at least one decision gate (11) and a clock recovery module (13) providing a clock signal (C) recovered from the optical signal to the at least one decision gate (11). The receiver (10) further comprises a scrambling frequency generator (16) synchronized to the scrambling frequency and phase of the polarization scrambled signal, a jitter function generator (17) generating a clock phase control signal (??b) reproducing the time jitter, and at least one clock phase modulator (14) modulating the phase of the clock signal (C) according to the clock phase control signal (??b).

Abstract: An optical identification signal generation section electrical-to-optical-converts and emits identification information. A modulation section modulates information data in a predetermined modulation type determined from the identification information. An optical data signal generation section electrical-to-optical-converts and emits the modulated information data. A two-dimensional optical-to-electrical conversion section receives the optical identification signal and acquires screen information including an image of the optical identification signal. An information reading section reads predetermined pixel information from the screen information and reproduces the identification information. An optical-to-electrical conversion section optical-to-electrical-converts the optical data signal. A demodulation section demodulates the information data in the predetermined demodulation type determined from the identification information, and reproduces the information data.

Abstract: Optical signals may be communicated with A/V Bridging services between an upstream link partner and a down stream link partner, each comprising an asymmetric Ethernet optical physical layer (PHY). High bandwidth A/V optical signals may be transmitted from the upstream link partner and low bandwidth optical signals may be transmitted from the downstream link partner. One or more of a time stamp, a traffic class and/or a destination address may be utilized in generating PDUs and managing communications via the asymmetric Ethernet optical PHY. The receiving link partner may register for deliver of the PDUs. An aggregate communication rate may be distributed evenly or unevenly among one or more optical links for transmission and aggregated upon reception via asymmetric Ethernet optical PHY operations. Compressed, uncompressed, encrypted and/or unencrypted optical signals may be handled. Signal processing may comprise forward error checking and clock recovery.

Abstract: A method and system is disclosed for making time alignment for a data transmission system. A first reference clock signal is provided to a first multiplexer coupled to a data modulator through a data driver, and a second reference clock signal is provided to a second multiplexer coupled to a clock modulator through a clock driver. Phase adjustment of the reference clock signal are conducted before the first reference clock signal is provided to the first multiplexer, wherein the phase adjustment aligns a timing of data modulated by the data modulator with a periodically modulated light source generated by the clock modulator.

Abstract: An apparatus has a cross connection circuit, first switching sections located on the input side of the cross connection circuit to switch a presently-used transmission path and a reserve transmission path, and second switching sections located on the output side of the cross connection circuit to switch the presently-used transmission path and the reserve transmission path and comprises slot sections, first selecting section selectively connecting any one of the slot sections to the input side of the first switching section, second selecting section connecting the output side of the first switching section to the input side of the cross connection circuit, third selecting section selectively connecting the output side of the cross connection circuit to the input side of any of the second switching sections, and fourth selecting section connecting the output side of the second switching section to any one of the slot sections.

Abstract: A DQPSK optical signal is split by the splitter 1 into Data 1 and Data 2 systems. For each system, a phase-modulated optical signal is converted into an intensity modulated electric signal, and clock reproduction and data reproduction are independently carried out for each system. While a phase difference occurs between the data of each system, a clock signal having an intermediate phase of the reproduced clock of each system is generated to latch data of both systems by using the clock signal. This results in the data of both systems having the same phase.

Abstract: A multiplexer of a transmission section generates a clock signal by multiplying a reference clock signal of a digital image signal by a predetermined number ‘K’. A parallel digital image signal is converted into a serial digital signal on the basis of the clock signal, and the serial digital signal is converted into an optical signal in an optical transmission section for transmitting. A demultiplexer extracts a reception clock signal from a serial digital reception signal which is converted into an electric signal in an optical reception section of a reception section, the serial digital reception signal is converted into a parallel signal and a signal corresponding to the parallel digital image signal on the basis of the reception clock signal, and a clock signal corresponding to the reference clock signal is recovered by multiplying the reception clock signal by ‘1/K’.

Abstract: Provided is an apparatus for testing the performance of an optical transceiver by referencing various performance clocks provided by an OTU2 signal connection transceiver and an STM-64/OC-192 signal. The apparatus for testing performance of an optical transceiver includes: a transmitter/receiver reference clock selector for selecting one of various transmitter/receiver reference clocks provided by an STM-64/OC-192 connection optical transceiver or an OTN connection optical transceiver; a transmitter test reference clock selection switch for selecting a receiver data synchronous clock provided by the transceivers or the selected transmitter/receiver reference clock as a transmitter test reference clock; and a receiver test reference clock selection switch for selecting a transmitter supervisory clock provided by the transceivers or the selected transmitter/receiver reference clock as a receiver test reference clock.

Abstract: A wavelength converter for binary optical signals includes an interferometer structure (110) for generating an output signal by modulating a received local signal (LS) according to the modulation of a fUrther received first input signal (IS 1). When such interferometer structures (110) are operated in a standard mode it is known in the art to control the power of the input signal such that the extinction ratio of the output signal is kept minimal. The invention also controls the power of the input signals to achieve the minimal extinction ratio when the wavelength converter and in particular the interferometer structure (110) is operated in a differential mode receiving two input signals.

Abstract: A system and method for providing two-way communication of quantum signals, timing signals, and public data is provided. Generally, the system contains a first public data transceiver capable of transmitting and receiving public data in accordance with a predefined timing sequence, a first optical modulator/demodulator capable of transmitting and receiving timing signals in accordance with the predefined timing sequence, a first quantum transceiver capable of transmitting and receiving quantum signals in accordance with the predefined timing sequence, and a first controller connected to the first public data transceiver, the first optical modulator/demodulator, and the first quantum transceiver. The first controller is capable of controlling the transmission of the public data, the timing signals, and the quantum signals in accordance with the predefined timing sequence.

Abstract: A method for transmitting traffic in an optical communication system comprising separating the input traffic into a plurality of data signals, parameter encoding the data signals, transmitting each of the data signals on a separate optical channel, receiving the data signals on the channels, parameter decoding the data signals, and combining the plurality of data signals from the channels into output traffic corresponding to the input traffic.

Abstract: A method of synchronising an optical transmitter and modulator comprising transmitting a calibration sequence of pulses from the transmitter to the modulator; varying a control timing drawn from the set comprising the transmit interval timings and the modulator transmission interval timings; monitoring the resulting pulses transmitted by the modulator and selecting a preferred control timing; controlling the optical transmitter and/or modulator responsive to the selected control timing. Corresponding apparatus, systems, signals and programs for computers to implement or control the arrangement are also provided.

Abstract: An upstream signal timing control method which controls a timing of an upstream optical signal, from a terminal device to a center device, to a timing that the center device intends. Optical clock pulses synchronized with the timing that the center device intends are sent from the center device to the terminal device. The terminal device delay-controls the optical clock pulses and retransmits them to the center device. The center device detects an offset between the timing and a timing of the returned optical clock pulses, and applies timing offset information to the transmitted optical clock pulses. The terminal device performs the delay control in accordance with the timing offset information applied to the received optical clock pulses. When the offset between the timing and the returned optical clock pulse timing is at or below a threshold, the center device verifies completion of timing control of the upstream optical signal.

Abstract: Jitter in a clock signal can cause communications faults in communications networks, such as in networks in which downstream nodes use recovered clock signals as timing for upstream communications. An embodiment of the present invention detects and compensates for jitter in a network by recovering a reference clock associated with communications signals between nodes, such as an Optical Line Terminal (OLT) and Optical Network Terminal (ONT) in a Passive Optical Network (PON). A local clock is synchronized with the reference clock. Jitter induced faults may be detected and compensated for by increasing the synchronization rate, then decreasing the synchronization rate until jitter induced faults begin to occur. A loss or change in a rate of communications errors occurring as a function of the synchronization rate may be monitored and reported to a system operator. Compensating for jitter by adjusting the synchronization rate provides for robust communications between network nodes.

Abstract: An optically sampling device optically samples an optical analog signal using a sampled signal having a predetermined sampling frequency, and outputs control light having a pulse train of an optically sampled optical analog signal. A signal generating device generates a pulse train of signal light which is synchronized with the sampled signal. An optical encoding device optically encodes the pulse train of the signal light according to the control light, by using optical encoders each including nonlinear optical loop mirrors, and outputs pulse trains of optically encoded signal light from said optical encoders, respectively. An optically quantizing device performs optical threshold processing on the pulse trains of optically-encoded signal light to optically quantize them, by using at least one of optical threshold processors each of which is connected to each of said optical encoders and includes a nonlinear optical device, and outputs optically quantized pulse trains as optical digital signals.

Abstract: Detecting a pulse of a signal includes receiving the signal and a light beam. The signal drives a spatial light modulator to modulate the light beam, where the complex amplitude of the modulated light beam is proportional to the signal current. The modulated light beam passes through an optical system and is detected by an optical detector array. A processor identifies a portion of the signal comprising the pulse.

Abstract: A system and method for detecting digital symbols carried in a received optical signal. The system comprises a functional element operative to receive a stream of samples of an electrical signal derived from the received optical signal and to evaluate a non-linear function of each received sample, thereby to produce a stream of processed samples. The system also comprises a detector operative to render decisions about individual symbols present in the received optical signal on the basis of the stream of processed samples. In an embodiment, the non-linear function computes substantially the square root of each received sample.

Abstract: The present invention provides an optical switch in which a switching operation is not affected even when the polarization state of a control light varies. The optical switch includes a loop-form optical waveguide loop circuit formed from an optical nonlinear medium, a control light input arrangement for inputting the control light into the optical waveguide loop circuit and serving as a phase control arrangement, a wavelength demultiplexing/multiplexing circuit, and a phase bias circuit.

Abstract: Systems and methods for reducing or eliminating timing errors in a quantum key distribution (QKD) system (100) are disclosed. The QKD system has a pulse generator with retimer (PGRT) that includes a field-programmable gate array (FPGA) (or FPGA output) which is used as a timing generator (TG). While an FPGA has the desired degree of programmability for use in a QKD system, it also suffers from undue amounts of jitter in the digital output. The present invention utilizes emitter-coupled logic (ECL) to reduce the timing jitter from the FPGA by coupling two ECL delays (ECL delay 1 and ECL delay 2) to the FPGA and to retiming block, and by using an ECL logical AND gate to set the pulse width of the various synchronization signals. An embodiment of the present invention includes multiple clock domains having individual clocks (CLK), phase-lock loops (PLLs), retiming circuits (RT) and timing generators (TG) for robust jitter reduction and hence highly accurate QKD system timing.

Abstract: An apparatus and a method for transmitting at least a digital optical signal with return-to-zero phase-shift keying, employing a single optical modulator with dual-drive design, the encoded optical signal having improved spectral efficiency and performances and being generated by transmitters with simplified scheme; an optical communication system comprising the transmitting apparatus, a transmission line and an apparatus to receive the optical signal.

Abstract: An optical transmission system capable of time difference correction without increasing guard times, thereby improving optical packet transmission efficiency. An optical switching processor sets identical switching timing for all input ports thereof such that optical signals input from the input ports are switched at the same timing. During initialization, a time difference corrector transmits an optical dummy packet to an optical switch node, and detects synchroneity of the optical dummy packet returned thereto after being switched by the optical switch node. If synchronization error is detected, the time difference corrector adjusts the output timing of the optical dummy packet so that the timing of arrival of the optical dummy packet at the optical switching processor may coincide with the switching timing of the optical switching processor, to thereby correct the time difference between the switching timing and the arrival timing.

Abstract: A technique for synchronizing the servo control systems between two optical wireless links (OWLs) that are in communication with one another. This synchronization allows the alignment in time of the various tasks to be assigned in a desired time period. The synchronization is not intended to synchronize the two OWLs down to the processor clock level, but rather at the servo sampling level, preferably to within a few percent of the servo sampling time. This synchronization may be advantageous in improving processor efficiency and control loop performance, and or improving system calibrations.

Abstract: Disclosed are a method and a system for generating switching control signal separating transmission signal on an access point and a mobile communication terminal in an optical repeater employing, for example, a TDD scheme. The method includes the steps of generating a control signal for generating a switching control signal in transmitting data from the AP and transmitting the control information to a remote during an idle time interval, detecting synchronization information on the downlink signal and time-delay information from the control information, delaying a time interval between the synchronization information and a starting point of the downlink signal, generating the switching control signal for the downlink signal according to the transmission time information of the downlink signal, and performing a switching operation according to the switching control signal and setting a downlink path.

Abstract: In a conventional network for transmitting an optical burst signal, it is impossible to effectively swap labels, reproduce a payload signal, and switch and transmit the signals.

Abstract: According to an aspect of an embodiment, an optical switch comprises: a coupler for coupling a signal light and a control pulse; a first nonlinear medium for amplifying the signal light in accordance with the polarization direction of the control pulse light by nonlinear effect; a first polarizer outputting a component light in a signal light and the control pulse light in parallel with the transmission axis of the first polarizer; a second nonlinear medium for changing status of polarization of the signal light by nonlinear effect; and a second polarizer outputting a signal light and a control pulse light in parallel with the transmission axis of the second polarizer.

Abstract: The present photonic RF generation and distribution system provides a system and method for distributing an RF output signal. The photonic RF distribution system includes two optical sources for generating optical signals. A first optical source (42) is operable to generate a first optical signal having an operating frequency. A second optical source (44) is operable to generate a second optical signal having an operating frequency. A modulator (46) is operable to impress an RF modulation signal on a tapped portion of the first optical signal such that a modulated signal is generated. A first coupler (52) combines the modulated signal with a tapped portion of the second optical signal, thereby forming a combined signal having a difference frequency component. A control photodetector (50) is responsive to the combined signal to generate a tone signal.

Abstract: All optical clock recovery includes a transmitter for generating an optical timing signal. The transmitter includes a semiconductor laser for the production of a dynamically synchronizable timing signal, the laser having an external resonator for feedback of the timing signal to the laser, the feedback having a delay time greater than a relaxation oscillation time for the laser, and the laser outputting an optical timing signal having a characteristic dynamic. The transmitter supplies the optical timing signal to a receiver configured to receive the timing signal and to synchronize to the laser on receipt of the timing signal, such that the receiver outputs a recovered timing signal having the characteristic dynamic.

Abstract: A core network shared by a large number of edge nodes comprises core nodes interconnected by core channels. Selected core channels are provided with buffers to enable temporal alignment of signals arriving at any core node from several other core nodes. A buffer may be provided at either end of a core channel. Otherwise, all other ports of the core node may be bufferless. Providing such buffers enables the construction of high-capacity wide-coverage network comprising a large number of core nodes shared by numerous edge nodes. Methods of temporal coordination among the network nodes are disclosed.

Abstract: The discrimination phase margin monitor circuit (10) of the present invention comprises a first discrimination circuit (11 and 12) discriminating an input data signal using a clock signal extracted from the input data signal, a second discrimination circuit (13 and 14) discriminating the input data signal using a clock signal with a frequency different from that of the clock and an operation circuit (15 and 16) calculating the exclusive OR of the output signal of the first discrimination circuit and that of the second discrimination circuit and obtaining a phase margin monitor output signal by averaging the exclusive ORs.