Abstract: An Ethernet-PON integrates broadcast/communication through time division multiplexing, which provides users with high-speed, high-volume communication data and high-quality, real-time digital broadcast/image data. An OLT performs a switching operation on a plurality of digital broadcast/image data received from an external broadcaster according to respective broadcast/image selection information from users, time-division-multiplexes the data into a broadcast/image signal, multiplexes the signal and communication data from an IP network into a frame, and electro-optically converts the frame and transmits to the frame to ONTs through an optical splitter. Each ONT receives and photoelectrically converts the signal from the OLT, and performs frame & time-slot demultiplexing to output the entire received communication signals and broadcast/image information contained in a time-slot assigned to the ONT to a corresponding user.

Abstract: A method and apparatus to accommodate differing output loads without sacrificing impedance matching in an optical modulator driver.

Abstract: To optimize the resources of an optical transmission network using wavelength division multiplexing, assigning carrier frequencies to signals to be transmitted consists in associating N sets of optical frequencies of the comb with N respective ranges of consecutive error rate values, each of the sets comprising frequencies generating a mean error rate in the associated range, defining a measured signal transmission constraint level that is a function of the transmission constraint parameter(s) and may take N distinct values referred to as constraint values, associating the N constraint values in increasing order respectively with the N sets of frequencies in decreasing order of the error rate values of the associated N ranges, assigning any signal to be transmitted a constraint value obtained by applying the measurement, and assigning the signal to be transmitted a carrier frequency belonging to one of the sets of frequencies that is associated with a constraint value at least equal to the constraint value as

Abstract: A method for communicating optical traffic in a network comprising a plurality of network nodes includes receiving traffic to be added to the network at a network node. The network is operable to communicate received traffic in an optical signal comprising one or more channels. The method also includes determining a data rate and one or more destination nodes of the received traffic and assigning the received traffic to one or more of the channels of the optical signal based on the determined data rate and the destination nodes. The method further includes configuring one or more of the network nodes to process the traffic contained in the assigned channels based on the data rate and the destination nodes of the optical traffic and communicating the traffic through network in the assigned channels of the optical signal based on the determined data rate and the one or more destination nodes.

Abstract: The method for operating an optical transponder, which performs maintenance of a signal in the optical transponder having a digital wrapper in an optical transmission system including multiple layers, includes (a) calling a processor for processing an interrupt when the interrupt is generated from the digital wrapper according to monitoring of a received signal; (b) the called processor detecting what defect is generated in the received signal and detecting whether or not the received signal requires maintenance; (c) performing defect processing in the case that a defect is detected at (b) or is cancelled; and (d) controlling the digital wrapper according to the defect and maintenance processing result.

Abstract: A wavelength stabilizing filter has a wavelength transmission characteristic curve that has its peak in a wavelength located between a first continuous set band and a second continuous set band longer in wavelength than the first set band, and that linearly drops from the peak toward the shorter wavelength side than the first set band and also toward the longer wavelength side longer than the second set band. A control unit generates a control signal needed to enable an optical tunable filter to extract signal light with a predetermined wavelength from an inputted WDM signal, based on light transmitted through the wavelength stabilizing filter.

Abstract: A self-healing passive optical network is disclosed. The network includes a central office and a remote node connected to the central office through a main optical fiber. The remote node transmits one portion of power of the upstream optical signal, which has been input from each of the optical network units, to the central office, and returning a remaining portion of the power of the upstream optical signal to the optical network unit. The network also includes a plurality of optical network units connected to the remote node through a plurality of distribution optical fibers. Each of the optical network units transmits an upstream optical signal to the remote node through the directly connected distribution optical fiber, and detects abnormality occurrences from a state of the upstream optical signal returning from the remote node.

Abstract: An optical source generator for wavelength-division-multiplexing optical communication systems includes a wavelength-division multiplexer/demultiplexer, optical amplifiers, and wavelength-dependent reflectors such as optical fiber-Bragg gratings or wavelength-independent reflectors such as mirrors, so as to form laser resonant cavities. Lasing of the optical fibers therefore generates spontaneously emitted lights. Further, the optical source generator controls each reflectance of the respective wavelength-dependent or independent reflectors so that lights amplified within the laser resonant cavities can be used as multi-wavelength optical sources or independent optical sources.

Abstract: A joint “packet-optical” layer restoration mechanism protects against single, packet-layer router failures by managing network resources from both the packet layer and the optical transport layer in a synergistic manner. It reuses packet-layer router service-ports and/or transport-layer service wavelengths associated with optical switch-ports instead of reserving additional standby packet-layer router service-ports. It can reuse resources from primary paths that are unaffected by router failures and paths that exist for link-failure protection at the optical layer. Embodiments feature a modified node structure that includes both an IP router and a dynamically reconfigurable OXC, which dynamically establishes connectivity between IP-router ports and transport-layer optical fibers. The joint-layer router provides fine-granularity grooming at the IP layer and full-fledged wavelength networking via dynamic wavelength switching and/or wavelength translation at the optical layer.

Abstract: A method, a device and a system for communications to and from a retro-reflector device (302) is provided. The retro-reflector device (302) receives a first frame (400) encoded in an input beam (106). The retro-reflector device (302) creates and sends a second frame (420) in a first reflected beam (108) formed by the retro-reflector device (302) reflecting the input beam (106) along a path closely aligned with a path of the input beam. At least one of the first frame (400) and the second frame (420) includes medium access control information. In some implementations, the first frame (400) may include a data throughput rate (404, 406), a preamble (402) and an error correction code (412).

Abstract: Disclosed herein is an apparatus for controlling a decision threshold voltage to an optical receiver, which is capable of automatically controlling the decision threshold voltage to the optical receiver appropriately to signal level decision on the basis of a low-frequency band signal component of an output signal from the optical receiver. The apparatus is adapted to control the level of the decision threshold voltage to the optical receiver, which converts an input optical signal into an electrical signal.

Abstract: An accurate method of reporting “minutes of outage” for a SONET facility applies a set of business rules and hierarchical definitions to delete certain minutes that would otherwise be counted as “outages”. In particular, any outage minutes reported for a network element taken out of service for “planned maintenance” activities are removed prior to performing the final count. Additionally, outage minutes for a “lower level” element (such as, for example an OC1 element) that overlap in time with outage minutes reported for a “high level” element are likewise removed before the count is performed. The elimination of these non-service impacting outage minutes thus results in a more accurate reporting of the actual service impact of the counted outage minutes.

Abstract: An optical network, which includes edge and switching nodes, optically communicate information formatted into statistically multiplexed control and data bursts and/or metadata. Control bursts are transmitted prior to the data bursts to configure optical switches in selected switching nodes so that the data bursts do not require O-E-O conversion. Each edge node consists of an adaptive PBS medium-access layer (MAC) component in order to achieve the transmission throughput improvement. The adaptive PBS MAC component enables the PBS data burst size to adapt to the TCP flow, allowing the PBS data burst to be transmitted immediately for the TCP flow experiencing TCP slow start. It performs a “deep” packet inspection of control packets coming back to the data source from the destination PBS network edge node to detect packet losses.

Abstract: Disclosed is a broadcast/communication unified passive optical network system.

Abstract: A communication optical system having a compact structure and capable of preventing crosstalk is disclosed. The communication optical system includes a light source, a light-receiving element and a beam-splitting member. The beam-splitting member performs one of transmission and reflection towards an incident/emergent port, and performs one of reflection and transmission towards the light-receiving element of a second light beam from the incident/emergent port. The light source and the light-receiving element are arranged on the same side with respect to the beam-splitting member.

Abstract: A polarization mode dispersion (PMD) controller device for controlling the state of polarization of an optical light wave comprising a dispersion compensation unit (2; 25; 40) and an adaptation control unit (6; 28; 44), wherein the dispersion compensation unit (2; 25; 40) comprises a multitude of compensation stages processing the optical light wave, and wherein the adaptation control unit (6; 28; 44) controls the dispersion compensation unit (2; 25; 40) is characterized in that at least one feed-forward signal tap (4; 26a-26c, 73a-73c) is provided tapping the optical light wave inserted into one of the compensation stages, that the feed-forward signal(s) is(are) fed into a distortion analyzer unit (5; 27; 66) and that the distortion analyzer unit (5; 27; 66) provides the adaptation control unit (6; 28; 44) with information about the incoming optical light wave. It accelerates the adaptation speed and lowers the costs of a high-speed PMD controller device.

Abstract: An optical communication method and apparatus are provided, the apparatus including polarization controllers, and drive circuitry for driving the polarization controllers at a plurality of frequencies such that the penalties from PMD, PDL and PDG are mitigated.

Abstract: In this application, the invention is a novel heuristic mechanism of working path and backup path reservation for highly utilizable WDM mesh networks, which we call dynamic-network adapted cost selection (DAC-selection) mechanism. One of its characteristics is simple traffic distribution mechanism, and the performance of DAC-selection mechanism is superior to that of Random selection (R-selection) and Advanced Combined Min-cost selection (ACM-selection) mechanism. DAC-selection mechanism provides simple cost function by assigning proper weights to each component of the cost function and the total cost is obtained by just summing up the individual cost. Therefore, it is possible to select a best pair of working path and backup path which consumes least wavelength for reservation.

Abstract: The present invention overcomes problems associated with switch isolation, noise and crosstalk suppression, insertion loss, spurious reflections, wavelength tolerance, and compactness that are present in varying degrees in other add/drop systems. The present invention includes devices or components that include, but are not limited to high efficiency switchable gratings.

Abstract: An optical transmission controller includes a semiconductor-laser, a semiconductor laser driver, a monitor photoreceptor, a waveform detector and a phase relation adjuster. The semiconductor laser driver allows the semiconductor laser to output an optical signal. The monitor photoreceptor monitors the optical signal output. The waveform detector detects a fall state of the optical signal output. The phase relation adjuster adjusts a phase relation between a fall timing of an input current and a variation timing of a relaxation oscillation of the optical signal output in accordance with a detection result of the waveform detector.