Abstract: A system for redundancy in Ethernet passive optical networks (EPONs) facilitates fast recovery from failure (less than 50 msec), path redundancy of the fiber optic network, and location redundancy of the OLTs. An optical networking unit (ONU) in a normal state monitors input communications, and when the input communications are quiet for a predetermined minimum length of time, the ONU transitions to a lenient state in which: the ONU accepts old and new security keys; upon receiving a packet: the ONU updates an ONU timestamp based on the packet's timestamp; and the ONU transitions to the normal state of operation. While the ONU is in the lenient state if a packet is not received for a predetermined given length of time the ONU transitions to a deregistered state. In this system, main and standby OLTs do not require synchronization of security parameters or synchronization for differences in fiber lengths.

Abstract: Disclosed is an RoF system providing an HD wireless communication service.

Abstract: In order to reduce the size and simplify the structure of a coherent light receiver, the coherent light receiver includes an optical mixer for coupling local oscillator light and reception signal light, a photoelectric converter for photoelectrically converting light coupled in the optical mixer, a reception data processing unit for extracting reception data included in the reception signal light through digital signal processing for processing the coupled signal converted into an electrical signal by the photoelectric converter, based on a first clock, and a modulator for modulating the local oscillator light or the reception signal light inputted to the optical mixer respectively, by using a clock phase-synchronized with the first clock used for the digital signal processing in the reception data processing unit.

Abstract: A device may include a communication interface to communicate with an optical line terminal and a processor. The processor may set an optical path from the optical line terminal to an optical network terminal, the optical path including one or more optical network elements. In addition, the processor may obtain, from the optical line terminal, a status reading of the optical network terminal when the optical path is set. Further, the processor may obtain, from the optical line terminal, a power reading at the optical network terminal when the optical path is set. The processor may record the status reading and the power reading.

Abstract: Provided is an optical access system comprising: an optical line terminal connected to another network; a plurality of optical network units, each connected to a user terminal; and at least one of an optical switching unit and an optical splitter, which is installed between the optical line terminal and the plurality of optical network units. The optical line terminal allocates a length of time to a discovery phase for detecting the plurality of optical network units, and a length of time to data transmission phases for transferring data from the plurality of optical network units; and changes a ratio of the length of time of the discovery phase to the length of time of the data transmission phases so that the length of time of the discovery phase is shortened in the case where a number of the optical network units that are registered in the optical line terminal increase.

Abstract: The present invention provides a frequency offset monitoring device and an optical coherent receiver. A low speed frequency offset monitoring device comprises a signal speed lowering section, for lowering the speed of an inputted signal and outputting the speed lowered signal, and a frequency offset monitor, for monitoring frequency offset of the speed lowered signal outputted by the signal speed lowering section.

Abstract: A repeater is disclosed that transmits an optical signal using wave division multiplexing. The repeater includes a demultiplexing unit that separates plural channels contained in the optical signal, an adjusting unit that adjusts at least optical power of each of the channels according to a control signal, a multiplexing unit that outputs a multiple wavelength signal in which the channels are multiplexed, and a monitoring unit that determines a modulation scheme and a bit rate of the optical signal for each of the channels so as to generate the control signal.

Abstract: A distributed antenna system is provided for communicating with a plurality of base stations. The distributed antenna system includes a system controller and a master unit communicating with at least one of the plurality of base stations. A remote unit communicates over a high data rate media with the master unit and/or a downstream remote unit. Alternatively, the distributed antenna system includes a controller and a digital time/space crosspoint switch controlled by the controller. A digitizing transceiver is in communication with the digital time/space crosspoint switch. The crosspoint switch is configured to transmit and receive digital data through the digitizing transceiver.

Abstract: Embodiments of a system that includes an array of chip modules (CMs) is described. In this system, a given CM in the array includes a semiconductor die that is configured to communicate data signals with one or more adjacent CMs through electromagnetic proximity communication using proximity connectors. Note that the proximity connectors are proximate to a surface of the semiconductor die. Moreover, the given CM is configured to communicate optical signals with other CMs through an optical signal path using optical communication, and the optical signals are encoded using wavelength-division multiplexing (WDM).

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: An optical transmission system capable of efficiently reducing waveform distortion of an optical signal. A transmitting-side distortion compensation coefficient storage of a transmitting station stores transmitting-side distortion compensation coefficients for compensating for waveform distortion of an optical signal to be transmitted to a receiving station. A transmit signal processor performs distortion compensation on the optical signal on the basis of a suitable transmitting-side distortion compensation coefficient stored in the transmitting-side distortion compensation coefficient storage. A transmitter transmits the distortion-compensated signal to a transmission path. A receiver of the receiving station receives the optical signal from the transmission path. A receiving-side distortion compensation coefficient storage stores receiving-side distortion compensation coefficients for compensating for waveform distortion of the optical signal received by the receiver.

Abstract: Described herein are systems and methods for a field-configurable optical network terminal (ONT) device at a subscriber to provide one or more communication services to the subscriber. The field-configurable ONT device is of a modular design operable for the insertion of additional communication modules or removal of existing communication modules from the ONT device for scaling the device to increased or decreased communication capacity as desired.

Abstract: There is provided an abnormal light cut-off system in which even when a high power light is inputted from an optical fiber connected to a user side apparatus by a malicious user or an accident, a trouble rate is low, the abnormal light is cut off at high sensitivity, and security is high.

Abstract: The present invention is a fiber optic data network, such as a passive optical network (PON), which includes a primary sub-network and a secondary sub-network. The primary sub-network may include a primary optical line terminal communicatively coupled to a plurality of primary optical network units. The secondary sub-network may include a secondary optical line terminal communicatively coupled to a plurality of secondary optical network units and to an intermediate optical network unit. The secondary sub-network may be communicatively coupled to the primary sub-network via the intermediate optical network unit, thereby allowing the PON to be configured so that the primary optical line terminal and the secondary optical line terminal are cascaded.

Abstract: A subsea monitoring system.

Abstract: An optical switch controller controls an optical interconnection network that variably connects at least one input data channel to a plurality of outputs channels via at least one switching element. An address reader module has at least one semiconductor optical amplifier optically processes an optical signal. The address reader module obtains information by reading a data tag from the input data channel, and outputs an address control signal based on the information. The address control signal can be used to control switching elements in the optical interconnection network.

Abstract: Systems and methods of polarization-time coding are disclosed. One method includes encoding information in orthogonal polarizations of light and correlated information in multiple time slots, and transmitting the information using the orthogonal polarizations in the time slots. Another method includes receiving a first input pair which specifies a first polarization state and a second input pair containing which specifies a second polarization state; transforming each input pair according to a matrix specifying a conjugate operation to produce four output pairs. The method further includes transmitting at a first time the first output pair using the first polarization state and the third output pair using the second polarization state. The method further includes transmitting at a second time the second output pair using the first polarization state and the fourth output pair using the second polarization state.

Abstract: A programmable optical network architecture and associated components employing a two-level orthogonal frequency division multiplexing (OFDM)/wavelength division multiplexed (WDM) mechanisms for bandwith virtualization.

Abstract: A system and method for data synchronization in Passive Optical Networks are disclosed. 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: Apparatus and methods for driving a transmitter to generate DNPSK signals is disclosed including generating N data streams comprising data symbols and for each of a plurality of sets of N simultaneous data symbols of the N data streams, imposing signals are on L of a plurality of signal lines, with the value of L corresponding to values of the N simultaneous data symbols. Signals on the plurality of signal lines are ANDed with a clock signal synchronized with the N data streams to produce RZ signals. The RZ signals are summed and the summed signal is input to a laser that produces an output having frequency modulation corresponding to the magnitude of the summed signal. The output of the laser is passed through an optical discriminator.