Abstract: A burst mode optical repeater is provided. The burst mode optical repeater receives optical signals, which are transmitted from a plurality of optical network units (ONUs) in a passive optical network (PON) to a central office using a time division multiplexing access (TDMA) method, and relays the received optical signals using an optical-electrical-optical (OEO) method. Since the burst mode optical repeater can be installed anywhere between an optical line terminal (OLT) and the ONUs, the number of subscribers and transmission range that can be supported by a corresponding network can be increased.

Abstract: In accordance with the teachings of the present invention, a system and method for transmitting traffic in a plurality of passive optical networks (PONs) is provided. In a particular embodiment, a method for transmitting traffic in a plurality of passive optical networks (PONs) includes transmitting traffic at a first wavelength and at a second wavelength from an optical line terminal (OLT). The method also includes combining the traffic in the first wavelength and the traffic in the second wavelength and splitting the combined traffic into a plurality of copies. The method further includes forwarding a first copy to a first wavelength router at a first distribution node and forwarding a second copy to a second wavelength router at a second distribution node, wherein the first wavelength router is coupled to a first set of optical network units (ONUs) and the second wavelength router is coupled to a second set of ONUs.

Abstract: The present invention is a method of transmitting data of different bit rates in a simple manner and, if positive minimal multiples whose multiple operation values on the bit time lengths 1/Ai for a plurality of communication bit rates Ai become common are minimal multiples ai respectively, an optical line terminal constitutes a time division multiplex signal composed of a first data area having a bit rate Ai/ai and including frame synchronization information and a second data area in which packets addressed to each optical network unit of the bit rate Ai are time division multiplexed, and transmits the time division multiplex signal to a plurality of optical network units via a branching/multiplexing means.

Abstract: An optical communication system which constructs, at low cost, a network that uses Time Division Multiplexing in at least one direction of the communication. The optical communication system includes an optical multiplexer/demultiplexer that mediates communication between a network unit and a plurality of terminal units. The optical multiplexer/demultiplexer regenerates a synchronization clock from a downstream signal light. In addition, the optical multiplexer/demultiplexer adjusts, using the regenerated synchronization clock, the delay times of a plurality of upstream signal lights received from the terminal units. The network unit and the terminal units do not need to control the timing of the upstream signal lights. Thus, the construction costs of the optical communication system are reduced.

Abstract: A transmission apparatus for use in fixed bandwidth communications and variable bandwidth communications. The transmission apparatus has a memory unit, which stores information contained in a frame and indicating the amount of data to be transmitted from a terminal device, a computing unit, which calculates a bandwidth amount to be assigned to the terminal device based on the data amount, and a transmission unit, which sends the calculated assigned bandwidth amount to the terminal device. The transmission apparatus is characterized in that the computing unit calculates bandwidth amounts to be assigned to different types of flow of which different transmission qualities are requested according to a priority level that is set to each flow type. The transmission apparatus is also characterized in that bandwidth is controlled by designating, instead of a necessary bandwidth amount, transmission starting timing and transmission ending timing, particularly for fixed bandwidth communication data.

Abstract: A transmission system for a passive optical network comprises a shared optical transmission apparatus, a shared electrical interface apparatus and a plurality of transmission convergence termination units. The shared optical transmission apparatus is configured for being coupled to an optical line termination unit via an optical fiber. The shared electrical interface apparatus is coupled to the shared optical transmission apparatus. The plurality of transmission convergence termination units is coupled to the shared electrical interface apparatus. Each one of the transmission convergence termination units is configured for selectively controlling the shared electrical interface apparatus.

Abstract: An apparatus automatically maintains bi-directional communication between an optical network unit (ONU) and a central office (CO) in a passive optical network (PON) when the CO changes from a first PON mode to a second PON mode. The apparatus senses a PON mode relating to downstream data flow from the CO to the ONU; and upon detecting a change in the PON mode from the first PON mode to the second PON mode, synchronizes the ONU to operate according to the downstream and upstream configurations of the second PON mode.

Abstract: A channel switching function is added to a wavelength division multiplexing passive optical network (WDM-PON) system, which is an access optical network system, and the potential transmission rate is increased by combining wide wavelength tunable lasers and a time division multiplexing (TDM) data structure and properly using the necessary optical components. In addition, when the wavelength of a light source or an arrayed waveguide grating (AWG) changes, the wavelength is traced and the magnitude of a transmitted signal is maximized without an additional detour line using a loop-back network structure. Furthermore, fewer thermo-electric controllers (TECs) are required for stabilizing the temperature of an optical line terminal (OLT) using wavelength tunable lasers, each laser electrically changing its wavelength.

Abstract: A method and system for ensuring confidentiality of signal transmission in a point-to-multi point data transmission network like Ether net passive optical network, including at least one hub, at least one transmission medium and at least one station connected to the hub via the transmission medium. When an upstream signal is transmitted from a first station, the upstream signal is reflected by at least one disturbing reflector for producing a disturbing reflection. The disturbing reflection combines with a second reflection of the upstream signal and renders the second reflection undependable by a second station.

Abstract: The present invention relates to allocating the use of optical light-trails. Optical light-trails enable a plurality of nodes included in a light-trail to share the use of an optical wavelength to transmit traffic between the nodes included in the light-trail. A method for allocating the use of an optical light-trail includes calculating a bid at each of one or more nodes included in the light-trail. Each of the nodes calculates a bid with consideration for the criticality of the node's need to transmit particular traffic on the light-trail. The method also includes transmitting the calculated bids from one or more of the nodes to an arbiter node. The arbiter node determines the maximum received bid, determines whether to allocate the use of the light-trail to the node associated with the maximum bid, and then communicates one or more control messages to the nodes that transmitted the bids indicating to which node use of the light-trail is allocated.

Abstract: In a passive optical network (PON), a burst-mode receiver of an optical line terminator (OLT) is initialized during an initialization phase, such as ranging, by asserting one or more reset signals in response to detecting the presence of a packet signal. For example, after the OLT transmits an initialization message, such as a ranging grant, to an optical network unit (ONU), it asserts one or more reset signals when it detects the presence of a packet signal received from the ONU in response.

Abstract: The present invention provides a kind of ultra-wide band wireless system, which changes the previous electronic structure for ultra-wide band pulse generator, and uses light to generate pulse signal, transformed by microwave differentiator to Gaussian monocycle pulse transmission signal, the derived pulse signal can provide several GHz bandwidth to transmit fast speed information, and further complete the new ultra-wide band wireless system. It reduces the complexity of electronic system and enhances output signal quality by means of light property, with considerable leading advantage. And the signal generated by this system has broader band and no infringe property, its 10 dB band falls within the range prescribed by the Federal Communication Committee of United States (FCC), successfully realizing the ultra wide band fiberoptic wireless collection network system, and further attaining the goal of seamless communication collection.

Abstract: The invention is applied to a PON system including an optical line terminal (OLT) at a center station, a plurality of optical network units (ONUs) at subscribers' sites, and an optical transmission line shared by the plurality ONUs to optically connect between the OLT and the plurality of ONUs. Each of the ONUs requests the OLT to assign a logical link according to start-up of an application.

Abstract: An enhanced Dense Wave Division Multiplexing (DWDM) network is optimized through bundling subchannel traffic in DWDM channels at network nodes and “hubbing” the DWDM channels at nodes receiving a relatively higher volume of aggregate traffic than other nodes. The optimization can eliminate low rate links and supporting network equipment. The bundling and hubbing may also be used independently from one another. The DWDM network may be enhanced with SONET, SDH, Ethernet, ATM, or other technology. The DWDM network may be a BLSR, UPSR, point-to-point, mesh, or other network configuration.

Abstract: A W-CDMA base station is disclosed in which a base band processing device and a plurality of remote radio devices are provided and downward data is transmitted from the plurality of remote radio devices at the same time. The base band processing device inserts a synchronous signal into downward data, and transmits the downward data to the remote radio devices. The remote radio device extracts the synchronous signal from the downward data transmitted from the base band processing device, inserts the synchronous signal into the upward data at an insertion timing based on an extraction timing when the signal is extracted, and transmits the upward data to the base band processing device.

Abstract: An optical network is disclosed that carries optical traffic in multiplexed wavelengths between a number of nodes. The network includes at least one light-trail associated with one of the wavelengths and established between a convener node and an end node, and including one or more intervening nodes. The network also includes an out-of-band control channel that is associated with a different wavelength than the light-trail. The control channel is used to communicate control messages to establish the light-trail and to allocate use of the light-trail by the convener node and the intervening nodes. Each of the convener node, the one or more intervening nodes, and the end node is operable to receive optical traffic in a number of multiplexed wavelengths from the optical network, drop a first copy of the multiplexed optical traffic from the optical network, and forward a second copy of the multiplexed optical traffic on the optical network.

Abstract: A system and method for simultaneous delivery of a plurality of independent blocks of 500 MHz digital broadcast television services, stacking a plurality of RF blocks on a plurality of spectrally sliced WDM optical bands.

Abstract: An optical access network system having a function of correcting upstream signal waveform distortions occurring in the PON section, wherein a central office side apparatus comprises a main controller to notify each subscriber connection apparatus of a transmission grant period, an equalizer of a tap gain adaptive control type to correct waveform distortions of signals received from the subscriber connection apparatuses, an equalizer controller, and a parameter table for storing, for each subscriber connection apparatus, the initial values of tap gains to be set for the equalizer. The main controller issues a switchover request for switching the equalization characteristic to the equalizer controller each time notifying a subscriber connection apparatus of a transmission grant period, and the equalizer controller retrieves the initial values of the tap gains for the subscriber connection apparatus from the parameter table in response to the switchover request, and sets these values to the equalizer.

Abstract: A system for integrating broadcast and communication technologies includes an optical-line terminal (OLT), a optical-network unit (ONU) and a user gateway, wherein a broadcast signal is processed on the basis of time division multiplexing (TDM) such that the quality of a broadcast service can be ensured. The ONU separates the optical signal transmitted from the OLT into the broadcast signal and the communication signal, processes upstream information transmitted from a user, and optically transmits the broadcast signal and the communication signal selected on a user-by-user basis, on the basis of a time slot. The user gateway opto-electrically converts a time slot-based optical signal transmitted from the ONU, separates the time slot-based optical signal into individual signals, distributes the individual signals on a service-by-service basis, and optically transmits the upstream information from the user to the ONU.

Abstract: An optical subscriber network system is disclosed, which comprises: a server bi-directional optical transmitter including a multiplexer to multiplexes communication data and broadcast data, a server laser diode to converts the multiplexed data into an optical signal, and a server photo diode receive communication data from a subscriber, wherein the server bi-directional optical transmitter transmits the upstream communication data; and a subscriber bi-directional optical receiver including a subscriber laser diode to transmit upstream communication data, a subscriber photo diode to receive the optical signal transmitted from the server bi-directional optical transmitter, and a demultiplexer to demultiplex and divide the multiplexed signal into communication data and broadcast data. In the optical subscriber network system, the optical transmitter and the optical receiver can transceive image signals and Ethernet communication signals in a two-way direction by means of a single laser diode and photo diode.

Abstract: This invention provides a new architecture for a communication system between head-ends and end-users which expands bandwidth and reliability of the communication system. A mux-node receives communication signals from a head-end and forwards the received communication signals to one or more mini-fiber nodes. The connection to the head-end is via a small number of optical fibers and the connections to each of the mini-fiber nodes may be via one or more optical fibers that may provide full duplex communication. The head-end may communicate with the mux-node using digital or digital and analog signals. The mini-fiber nodes may combine the signals received from the head-end with loop-back signals used for local media access control prior to forwarding the signals to the end-users. Upstream data are received by the mini-fiber nodes and transmitted to the mux-node.

Abstract: Disclosed is a upstream data transmission method in a gigabit Ethernet-passive optical network (GE-PON) system. In the GE-PON system including an optical line termination having a scheduler and optical network units connected to the optical line termination, the optical line termination receives bandwidth allocation request signals from the optical network units at a start of a first cycle, allocates transmission bandwidths to the respective optical network units in accordance with the bandwidth allocation request signals, and transmits the allocated transmission bandwidths to the respective optical network units before a second cycle that follows the first cycle.

Abstract: An Ethernet passive optical network provides a subscriber with a high speed and large capacity data service and a real time digital broadcast/video service. The network includes an optical line terminal for frame-multiplexing broadcast/video signals, which are obtained by performing a switching operation and a time-slot multiplexing with respect to a plurality of digital broadcast/video data delivered from external broadcasting vendors according to broadcast/video selection information delivered from each user, and communication data delivered through an Internet protocol network.

Abstract: A method for transmitting a packet in a wireless access network based on a wavelength identification code scheme. The method comprises the steps of connecting n number of RNCs (Radio Network Controllers) to one sub-ring where the “n” is a positive integer, and assigning a unique wavelength to each RNC; identifying a packet to be transmitted between the RNCs located within a same sub-ring using the assigned unique wavelength, and transmitting the packet through an SRC (Sub-Ring Controller); connecting m number of SRCs to one main-ring where the “m” is a positive integer, and assigning a unique wavelength to each SRC; and detaching a wavelength identification code from the packet to be transmitted between the RNCs located within different sub-rings, and transmitting the packet having the encapsulated wavelength identification code through an MRC (Main-Ring Controller).

Abstract: A fiber to the home FTTH network for convergence of broadcasting and communication is disclosed. The network includes: an OLT for receiving and converting a first predetermined number of broadcast signals and an Ethernet signal into a plurality of converted optical signals, combining the converted optical signals into converged optical signals for subsequent transmission by an optical wavelength division multiplexing method; and an optical network unit (ONU) for classifying the optical signal transmitted from the OLT into the first predetermined number of broadcast signals and the Ethernet signal, switching a second predetermined number of broadcasting signals of the first predetermined number of broadcasting signals according to each SIU by channel selection information contained in upstream Ethernet information, and switching the Ethernet signal to be transmitted to the SIU according to each SIU so as to transmit the switched signal.

Abstract: An optical modulator using a thin plate including a portion having 20 ?m or less thickness, capable of selecting a specific polarized wave from a light wave which propagates in an optical waveguide in the modulator without reduced productivity. The modulator includes an X-cut or Y-cut thin plate of a material having an electrooptic effect; an optical waveguide formed in a top or bottom surface of the plate; and a control electrode on the top surface of the plate to modulate light which propagates in the waveguide. An attenuating means which absorbs light having a specific polarization plane of a light wave which propagates in the waveguide is disposed in the vicinity of the waveguide. The attenuating means includes light absorbing members disposed at a gap L which is 0.5 to 2 times the mode-field diameter of the light wave which propagates in the waveguide with the waveguide interposed therebetween.

Abstract: An optical transmitter including a multi-lambda source to output injection light consisting of a plurality of injection wavelengths in channels, a circulator having a first port, a second port, and a third port, the circulator receiving the injection light at the first port, and outputting the received injection light to the second port, and further receiving signal light at the second port, and outputting the received signal light to the third port, an arrayed waveguide grating having a multiplexing port connected to the second port of the circulator, and a plurality of demultiplexing ports, spectrum-slicing injection light received from the circulator at the multiplexing port into a plurality of injection channels, and outputting the injection channels to the demultiplexing ports and further receiving and multiplexing a plurality of signal channels at the demultiplexing ports, into a signal light, and outputting the signal light to the multiplexing port, and a plurality of reflective semiconductor optical a

Abstract: A wavelength access server (WAS) architecture provides aggregation of traffic streams of diverse data communication protocols as well as provision of wavelength resources in an optical transport network. The WAS provides functions such as service traffic adaptation, traffic aggregation and segmentation, traffic classification, optical inter-working and system management. In particular, system management includes aspects such as signaling, connection management, resource co-ordination, protection prioritization and access policy management.

Abstract: The present invention provides an optical wavelength-division multiple access system and a corresponding optical network unit. A wavelength band Da (wavelengths ?d1 to ?dn) for downlink optical signals corresponding to the n ONUs, a wavelength band Ua (wavelengths ?u1 to ?un) for uplink optical signals corresponding to the n ONUs, a wavelength band Db (wavelengths ?dn+1 to ?dn+m) for downlink optical signals corresponding to the m ONUs, and a wavelength band Ub (wavelengths ?un+1 to ?un+m) for uplink optical signals corresponding to the m ONUs are set different from one another, the wavelength bands Ua and Ub are set adjacent to each other, and the wavelength bands Ua and Da or the wavelength bands Ub and Db are set adjacent to each other.

Abstract: The network comprises an optical ring link (F) and a concentrator (HUB) that sends via one end of the link “downlink” optical signals carried by respective wavelengths and receives “uplink” optical signals via the other end of the link. The link is divided into a plurality of segments (FS1-FS4) separated by access nodes (AN1-AN3) for receivers (RX) of downlink optical signals and for senders (TX) of uplink optical signals. Each access node comprises coupling means that are not wavelength-selective for coupling the segment on the upstream side of the node to the segment on the downstream side and to the receivers and to couple the senders (TX) to the segment on the downstream side. The downlink optical signals are carried by wavelengths belonging to a set of predefined wavelengths. To optimize the use of spectral resources, a rejection filter (NF) is inserted into a segment to reject a portion of the wavelengths of said set of wavelengths.

Abstract: A passive optical network which employs multiple wavelengths to increase overall system bandwidth, with each wavelength being shared by multiple optical network units (ONUs) according to a time division multiple access (TDMA) protocol. The upstream TDMA traffic therefore includes multiple TDMA data streams at different wavelengths. An optical line terminal (OLT) preferably receives the multiple TDMA data streams and separates them to different detectors before ultimately combining all data into a single data stream using a multiplexer after performing clock and data recovery functions. In this manner, the upstream bandwidth in a passive optical network can be markedly increased without requiring an increase in data transmit speeds, and while using low cost/low speed detectors in the OLT, and low cost/low speed transceivers in the ONUs. System bandwidth can be further improved by using higher cost, higher speed components.

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 termination device for use in a WDM-SCM PON system can effectively support a multi-channel integration function of a WDM/SCM PON system.

Abstract: An Ethernet passive optical network (EPON) ring for providing protection against fiber failures. The optical network unit (ONU) is coupled to the ring fiber by a three-port passive optical splitting module that has three two-way optical passages. By the three two-way optical passages, the OUN receives/transmits data from/to the two ends of the optical line termination (OLT) to provide protection while the fiber failure. Moreover, it provides better authorization of users and simpler collision detection by the two-way transmission of the three-port passive optical splitting module to prevent hackers from invading and to reduce collisions.

Abstract: An optical network terminator of the present invention includes an optical wavelength division multiplexer for receiving an optical signal and incoherent light. An optical detection unit converts a downstream high speed and low speed optical signals into electrical signals. A laser diode converts an upstream signal into an optical signal. A high speed driving unit is supplied with power from a power supply unit to drive a forward-biased laser diode and establish a data and video channel. A high speed reception unit is supplied with the power to receive a downstream data and video channel. A charging unit outputs charged power at the time of a power failure. A low speed driving unit is supplied with the charged power to reverse-bias the laser diode to establish a voice channel. A low speed reception unit is supplied with the charged power to receive a voice channel.

Abstract: A method and a system in which selected wavelengths of a wavelength division multiplexed (WDM) signal are modulated with multicast data for multicasting data services on an optical network. The WDM signal is received from a hub node of the optical network, such as a unidirectional ring network or a bi-directional ring network. A four-port wavelength crossbar switch (4WCS) selectably switches selected wavelengths from the optical network to a modulator loop. The modulator loop includes a multicast modulator that modulates the selected plurality of wavelengths with the multicast data. Each modulated wavelength is then switched back to the optical network by the 4WCS switch, and sent to a plurality of subscriber nodes of the optical network. This architecture allows a facility provider to be physically separated from a content provider, and affords the flexibility of selectively delivering multicast content to individual subscribers.

Abstract: An optical power converting apparatus is provided that may be used with remote sensors. A plurality of remote sensors may be coupled to a backbone optical fiber with each sensor having an optical power converter that receives an optical signal from a head end of that fiber. The optical power converters may store electrical energy derived from that optical signal and use that energy to power the remote sensors. The head end's optical signal may also include a clock signal, and each remote sensor may be set to sense a measurable parameter after a given number of clock cycles have been counted. In a further example, each of the optical sensors may be synchronized before counting these clock signals via a synchronization signal from the optical power converter. The remote sensors may individually and separately uplink their sensed data to the head end on the optical fiber. The apparatus may be implemented in a vehicle health management system, for example.

Abstract: An optical network provides a digital interconnect fabric allowing nodes to seamlessly communicate with each other. Each node is connected to a bi-directional optical bus through passive optical interface devices. The optical interface devices route signals from each node onto the bus in both directions and also route signals traveling along the bus in either direction to each node. The optical interface devices and optical bus are passive and do not involve any regeneration of the electrical signals. The nodes are assigned wavelengths of transmission and have tunable receivers for selecting a wavelength of reception. The digital interconnect fabric facilitates Ethernet, Fibre Channel, and other digital communication protocols.

Abstract: The present invention is a method of transmitting data of different bit rates in a simple manner and, if positive minimal multiples whose multiple operation values on the bit time lengths 1/Ai for a plurality of communication bit rates Ai become common are minimal multiples ai respectively, an optical line terminal constitutes a time division multiplex signal composed of a first data area having a bit rate Ai/ai and including frame synchronization information and a second data area in which packets addressed to each optical network unit of the bit rate Ai are time division multiplexed, and transmits the time division multiplex signal to a plurality of optical network units via a branching/multiplexing means.

Abstract: A broadcast/communication convergence system, and an FTTH (Fiber To The Home) system that can accommodate broadcast signals of various channels and variable band signals by converging broadcast and communication signals and transmitting the converged broadcast and communication signals using an IEEE 1394 transmission method serving as a standard interface in the FTTH system for broadcast/communication convergence. An OLT (Optical Line Terminal) transfers a plurality of broadcast signals and a communication signal received from external broadcast and communication providers through a single optical signal (A).

Abstract: An optical network unit (ONU) interconnected by passive optical network (PON) equipment to an optical line terminal (OLT) is identified using secondary modulation of the optical carrier to impress an identifier of the ONU onto the carrier. This resolves a recurring ONU failure mode detection problem caused by failure of a laser driver that causes the ONU to be stuck in an on state.

Abstract: In an optical transmission apparatus in which a plurality of nodes are optically connected to one another via an optical transmission path, a light signal which is coded so that a mixture ratio of 1 and 0 constituting data is made close to 50% is transmitted through the optical transmission path. When a light signal is not emitted from all of the nodes, a dummy signal which is an AC-like signal is emitted to the optical transmission path. Therefore, an optoelectric conversion section can be always set to an active state, and the signal recognizability can be prevented from being lowered.

Abstract: An optical transmission system accomplishes optical transmission over a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission over a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-toelectric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, and with no use of any optical booster amplifier and optical preamplifier in multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.

Abstract: This invention provides a new architecture for a communication system between head-ends and end-users which expands bandwidth and reliability of the communication system. A mux-node receives communication signals from a head-end and forwards the received communication signals to one or more mini-fiber nodes. The connection to the head-end is via a small number of optical fibers and the connections to each of the mini-fiber nodes may be via one or more optical fibers that may provide full duplex communication. The head-end may communicate with the mux-node using digital or digital and analog signals. The mini-fiber nodes may combine the signals received from the head-end with loop-back signals used for local media access control prior to forwarding the signals to the end-users. Upstream data are received by the mini-fiber nodes and transmitted to the mux-node.

Abstract: There is disclosed an optical pickup device having semiconductor laser light sources for first, second, and third wavelengths different from each other. After optical paths of laser beams outgoing from the first and second semiconductor laser light sources are synthesized by a first prism, an optical path of a laser beam outgoing from the third semiconductor laser light source is synthesized, through a magnification change lens, to raise light efficiency. At this time, each of the laser beams is synthesized by a second prism.

Abstract: A passive optical network. The optical network has an optical fiber ring with ends terminating at an optical line terminal. The optical line terminal transmits signals through the fiber ring to optical network units passively connected to the fiber ring. The optical network units receive signals from the optical line terminal through the fiber ring. In one embodiment, the optical line terminal transmits redundant signals in opposite directions through the fiber ring and the optical network units receive the redundant signals from opposite directions through the fiber ring. In another embodiment, the optical network units receive TDM signals from and transmit TDMA signals to the optical line terminal through a fiber line. A first WDM coupler passively connected to the fiber line multiplexes an overlay signal with at least one of the TDM signals and the TDMA signals for transmission through the fiber line. The overlay signal has a wavelength different than the signals with which it is multiplexed.

Abstract: An optical power converting apparatus is provided that may be used with remote sensors. A plurality of remote sensors may be coupled to a backbone optical fiber with each sensor having an optical power converter that receives an optical signal from a head end of that fiber. The optical power converters may store electrical energy derived from that optical signal and use that energy to power the remote sensors. The head end's optical signal may also include a clock signal, and each remote sensor may be set to sense a measurable parameter after a given number of clock cycles have been counted. In a further example, each of the optical sensors may be synchronized before counting these clock signals via a synchronization signal from the optical power converter. The remote sensors may individually and separately uplink their sensed data to the head end on the optical fiber. The apparatus may be implemented in a vehicle health management system, for example.

Abstract: The invention relates to the distribution of a synchronization signal in an optical communication system which is inherently asynchronous. In order to accomplish a cost-efficient mechanism for transmitting a synchronization signal in such a system, the amplitude of a payload signal is modulated with the synchronization signal, whereby an amplitude-modulated payload signal is obtained. This amplitude-modulated payload signal is transmitted as an optical signal to the opposite end of an optical link, where the synchronization signal is separated from the payload signal.

Abstract: A bit synchronization circuit composed of a multiphase data sampling unit for converting each received burst data sets to multiphase data trains, a phase determination unit for generating a control signal indicating an optimum phase data train, an output data selector for selectively passing optimum phase data train indicated by the control signal, and a data synchronization unit for converting the optimum phase data train to a data train in synchronization with a reference clock. The phase determination unit repeatedly detecting the optimum phase data train during the same burst data set is received. When optimum phase varies, the output data selector dynamically switches the optimum phase data train to be supplied to the data synchronization unit.

Abstract: A repeating apparatus and method using wireless optical transmission is disclosed. The repeating apparatus includes a donor device for transmitting two identical copies of an optical signal by receiving a RF signal from a base station and electro-optic converting the RF signal to an optical signal, and for transmitting a RF signal by receiving two identical copies of the optical signal and optic-electro converting the optical signal to a RF signal; and a coverage device for transmitting a RF signal to a mobile communication terminal by receiving two identical copies of the optical signal from the donor device and optic-electro converting the two identical copies of the optical signal to the RF signal, and transmitting two optical signals to the donor device by receiving the RF signal from the mobile communication terminal and elector-optic converting the RF signal to the optical signal.