Abstract: A communication network (1) comprising an optical transport domain network (2) having optical transport nodes connected to each other via physical optical links, packet switched networks (3) each having a boundary router (4) connected to an optical transport node of said optical transport domain network (2) via an access link (5); and a network management apparatus (6) adapted to perform an automatic bandwidth management of said communication network (1), wherein said network management apparatus (6) is adapted to activate or deactivate virtual links (VL), tributary ports and cross-connections between virtual and access links in the optical transport domain (2) in response to data traffic statistics of data transmitted on said access links (5).

Abstract: A method includes monitoring a parameter of an optical signal transmitted between two endpoints via an optical fiber. The optical fiber may be manipulated to modulate the parameter without disconnecting either endpoint of the optical fiber. Data in accordance with the modulation of the monitored parameter may be identified. A portion of the optical fiber may be wrapped around a high order mode filter (HOMF) that includes a grooved cylinder or mandrel suitable for wrapping the optical fiber. The monitored parameter may include a received power parameter. The HOMF may be a variable diameter HOMF that can be transitioned between a wrapped or attenuating diameter and an unwrapped or non-attenuating diameter in accordance with a data pattern. The wrapped and unwrapped diameters may be defined relative to a threshold diameter, above which the monitored parameter may be independent of the diameter.

Abstract: A method and device for detecting shared risk link groups is disclosed. The method comprises injecting a probe beam, respectively, into a first test link and a second test link. The method further includes recording, respectively, a first curve of a time-varying first power corresponding to the first backlight and a second curve of a time-varying second power corresponding to the second backlight; calculating a resemblance value for the first curve and the second curve; and judging, based on the resemblance value, whether the first test link and the second test link are located in the same shared risk link group. The method and device for detecting shared risk link groups provided by embodiments of the present invention detect by testing a power characteristic of backlight of a probe beam in test links and, based on that one-dimensional power characteristic, judge whether the test links are in the same shared risk link group, which are simpler in application than those in the prior art.

Abstract: A communications device may include a local device, a remote device, and a multi-mode optical fiber coupled between the local device and the remote device. The local device may include a local spatial optical mux/demux coupled to the multi-mode optical fiber and having first and second local optical outputs and first and second local optical inputs, and a local electro-optic E/O modulator coupled to the second local optical input. The remote device may include a remote spatial optical mux/demux coupled to the multi-mode optical fiber, and a remote E/O modulator configured to generate a modulated signal onto a first remote optical output based upon modulating the first optical carrier signal from a first remote optical input responsive to a radio frequency (RF) electrical input signal.

Abstract: An optical transceiver configured to interface a composite signal in a parallelized manner includes a plurality of transmitters each configured to transmit a part of the composite signal over a first optical fiber; a plurality of receivers each configured to receive a part of the composite signal over a second optical fiber; a clock forwarding mechanism configured to provide a transmitted optical clock for all of the plurality of transmitters; and a clock recovery mechanism configured to receive a received optical clock for all of the plurality of receivers.

Abstract: The present invention provides a fiber-cut detection method, apparatus, and system. When a fiber cut occurs, power of input signal light decreases quickly at a fiber-cut location. When the fiber-cut location is relatively far away from an amplifier, pump light consumption of the input signal light in the remaining fiber reduces due to reduction of the input signal light, which causes an increase of remaining pump optical power in the fiber and an increase of an actual gain value of the amplifier. A gain-locking function of the amplifier works, which decreases pump power of the pump light and maintains a gain of the amplifier unchanged basically. Output optical power of the amplifier decreases quickly with decrease of input optical power, and when power of an output optical signal decreases to power that is lower than preset power of the output optical signal, it is determined that a fiber cut occurs.

Abstract: Anode for burst switching of traffic flows in an optical network switches bursts of traffic flows in different time slots. Time slots are allocated (96) so that a time gap between successive allocated time slots is selected according to a jitter specification of the traffic flow. A map of the allocations controls a burst switch to pass the bursts in their allocated time slots (86). By making the time gap between allocated time slots for successive bursts selectable, the jitter can be controlled more precisely, or the proportion of time slots filled can be increased resulting in better utilization of available bandwidth. The allocation can be made hop by hop. The map can be generated in a distributed and duplicated manner at each node. The allocation can be updated to adapt to changes bandwidth demands.

Abstract: Signal processing sections selectively switch modulation/demodulation in low-efficiency modulation system and modulation/demodulation in high-efficiency modulation system, and perform digital signal processing. Parallel-side interfaces of input/output interface sections are electrically connected to the signal processing section. A serial-side interface of the input/output interface section is electrically connected to a serial-side interface of the input/output interface section. A selection section electrically connects a parallel-side interface of the input/output interface section to the signal processing section when the low-efficiency modulation system is selected, and electrically connects the parallel-side interface of the input/output interface section to a parallel-side interface of the input/output interface section when the high-efficiency modulation system is selected.

Abstract: A coherent transceiver system includes a local oscillator (LO) light source to generate an LO optical signal. An adaptive fiber array is coupled to the LO light source to dephase the LO optical signal. A balanced detector is coupled to the adaptive fiber array to receive a dephased LO signal from the adaptive fiber array and an optical input signal and to generate a heterodyne signal. A controller receives the heterodyne signal and generates one or more control signals. The adaptive fiber array utilizes the control signals to dephase the LO optical signal.

Abstract: An optical transmitter transmits optical signal including a first signal and a second signal. The second signal is subjected to change in a polarization state relative to a polarization state of the first signal. An optical receiver analyzes a reception characteristic of the second signal and detects, based on the analyzed result, a polarization state of the first signal indicative of a higher signal quality than that of the second signal.

Abstract: Disclosed systems and methods transmit and receive data encoded as optical signals that include a progression of symbols, with each symbol represented as a combination of light frequencies. Light is used as the carrier medium to limit reception to devices that are within visible range of the transmitting device. No mapping of data to symbols is required for generation of the symbol progression by the transmitter and no mapping of symbols to data for recognition of the symbols is required by the receiver. Disclosed embodiments allow arbitrary selection among a plurality of mappings between symbols sent and symbols received. Embodiments are robust to: ambient lighting conditions, differences in optical and temporal response of the first and second devices, and differences in relative orientation between the first and second devices. Embodiments enable a variety of functions including device discovery, feature discovery, beacon identification, status reporting, error readout, key exchange, and authentication.

Abstract: A method of registering an optical network unit (ONU) in an optical line terminal (OLT). The OLT determines a lane to be used by the ONU based on a transmission rate supported by the ONU, combines or distributes data of a dataflow based on a rate of the lane by comparing the rate of the lane to a rate of the dataflow of a media access control (MAC) client interface, and, when the OLT and the ONU are connected through multiple lanes, transmits and receives data between the OLT and the ONU through channel bonding for more effective use of a network.

Abstract: Optical network units (ONUs) for high bandwidth connectivity, and related components and methods are disclosed. A fiber optical network ends at an ONU, which may communicate with a subscriber unit wirelessly at an extremely high frequency avoiding the need to bury cable on the property of the subscriber. In one embodiment, an optical network unit (ONU) is provided. The ONU comprises a fiber interface configured to communicate with a fiber network. The ONU further comprises an optical/electrical converter configured to receive optical downlink signals at a first frequency from the fiber network through the fiber interface and convert the optical downlink signals to electrical downlink signals. The ONU further comprises electrical circuitry configured to frequency convert electrical downlink signals to extremely high frequency (EHF) downlink signals at an EHF, and a wireless transceiver configured to transmit the EHF downlink signals to a proximate subscriber unit through an antenna.

Abstract: The present invention discloses a cable distribution device for an intelligent optical distribution network (iODN), comprising a tray and a cable distribution structure for the iODN, where the tray is provided with multiple first interfaces, the cable distribution structure for the iODN includes multiple attachment plates, an upper cover, a circuit board, and a bottom cover, the circuit board is installed on the upper cover, the upper cover is installed on the bottom cover, one end of each attachment plate is installed on the bottom cover, and the other end of each attachment plate is inserted into the first interface of the tray. the cable distribution structure for the iODN may be installed on a tray by using attachment plates, so that an existing ODN can be transformed into an iODN without transforming a structure of the tray and interrupting an optical fiber transmission service.

Abstract: A system for providing underwater communication using orbital angular momentum (OAM) includes a transmitter that processes input data to be transmitted using pre-coding information based on current transmission channel conditions to maximize data rate based on channel conditions. A receiver receives a transmitted multiplexed OAM optical signal and analyzes the received signal for channel state information. The channel state information is used to determine a set of pre-coding values that allow the transmitter to pre-code the input data to maximize the data rate based on current channel conditions. The pre-coding values are mapped to a codebook entry which identifies the pre-coding values. The codebook entry is transmitted from the receiver to the transmitter. The transmitter uses the received codebook entry to identify pre-coding values used to process subsequent input data to be transmitted in order to enhance data rate across the transmit channel.

Abstract: Techniques are disclosed for enhancing indoor navigation using light-based communication (LCom). In some embodiments, an LCom-enabled luminaire configured as described herein may include access to a sensor configured to detect a given hazardous condition. In response to detection of a hazard, the LCom-enabled luminaire may adjust its light output, transmit an LCom signal, or both, in accordance with some embodiments. A given LCom signal may include data that may be utilized by a recipient computing device, for example, in providing emergency evacuation routing or other indoor navigation with hazard avoidance, emergency assistance, or both. In a network of such luminaires, data distribution via inter-luminaire communication may be provided, in accordance with some embodiments, via an optical interface or other wired or wireless communication means. In some cases, the network may include a luminaire that is not LCom-enabled yet still configured for inter-luminaire communication.

Abstract: The present invention is directed to optical communication systems and methods thereof. In various embodiments, the present invention provides method for linearizing Mach Zehnder modulators by digital pre-compensation and adjusting the gain of the driver and/or the modulation index. The pre-compensation can be implemented as a digital pre-compensation algorithm, which is a part of an adaptive feedback loop. There are other embodiments as well.

Abstract: An example optical module includes: an optical splitter configured to split a received incident optical signal into a first optical signal and a second optical signal; a wavelength filter sheet configured to receive the second optical signal to reflect a first part of the second optical signal to generate reflected light, and to transmit a second part of that to generate transmitted light; a first photo detector configured to convert the reflected light into an electric signal; a second photo detector configured to convert the transmitted light into an electric signal; and an MCU configured to obtain the first detected signal and the second detected signal, to determine the difference in optical power between the reflected light and the transmitted light, and to determine from the difference in optical power and a specified standard difference in optical power whether the wavelength of the second optical signal is shifted.

Abstract: An apparatus comprises: a first input tap; a first optical modulator coupled to the first input tap; a first output tap coupled to the first optical modulator so that the first optical modulator is positioned between the first input tap and the first output tap; and a controller indirectly coupled to the first input tap and the first output tap.

Abstract: The embodiments of the present application disclose a method and device for sending and receiving an optical signal. The method for sending an optical signal comprises: performing serial-to-parallel conversion on a data signal to be transmitted to obtain an I path data sequence, a Q path data sequence and a PPM path data sequence which are in parallel; performing mPQ-encoding on the I path data sequence, the Q path data sequence and the PPM path data sequence to obtain an I path and a Q path of an mPQ-encoded digital signal; shaping the I path and the Q path of the mPQ-encoded digital signal by Nyquist-filtering to obtain an I path and Q path of a filtered digital signal; performing digital-to-analog conversion on the I path and the Q path of the filtered digital signal and mapping the converted I path and Q path onto an optical carrier to obtain a target optical signal and send the same.