Abstract: A contents information delivery method for delivering a desired contents information by transmitting an optical signal from a central station to each of a plurality of user stations via a transmission line includes: a first step (S1) of outputting an optical signal containing the contents information as an optical signal having mutually different wavelengths each assigned for the each user station in advance, in the central station; a second step (S2) of transmitting an optical signal having a plurality of wavelengths outputted via the transmission line in the first step; and a third step (S3), in which each user station receives the optical signal having the wavelength assigned from among the transmitted optical signals, whereby, this simple configuration does not limit the transmission rate, the coding format, or the like in an optical access system, i.e., making it possible to cope with a super-large capacity.

Abstract: Disclosed herein is a shared Local Area Network (LAN) emulation method and apparatus. The method includes the following four steps. At the first step, a Logical Link Identifier (LLID) management table is set up to assign unique LLIDs to a plurality of Optical Network Units (ONUs) and manage the assigned LLIDs so as to identify the plurality of ONUs connected to a single Optical Line Terminal (OLT). Thereafter, a MAC address table is set up for the LLIDs to learn MAC addresses of the ONUs. Thereafter, the unique LLIDs are assigned to ONUs when the ONUs request registration from the OLT. Finally, data frames, which are received by a Shared LAN Emulation (SLE) layer of the OLT, are bridged using the LLIDs, VIDs of Virtual LANs to which the ONUs belong and destination MAC addresses of the data frames so as to provide a single matched port between a Logical Link Control (LLC) layer and a MAC layer of the OLT.

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: In an optical data network, such as a passive optical network (PON), an optical line terminator (OLT) measures the strengths of one or more signals received from the optical network units (ONUs) and generates a message containing an indication responsive to the measured signal strength. The OLT transmits the message to the ONUs. The ONUs generate packets having preambles of a length responsive to the indication contained in the message.

Abstract: An optical fiber network can include an outdoor bandwidth transforming node that can be positioned in close proximity to the subscribers of an optical fiber network. The outdoor bandwidth transforming node does not require active cooling and heating devices that control the temperature surrounding the bandwidth transforming node. The bandwidth transforming node can adjust a subscriber's bandwidth on a subscription basis or on an as-needed basis. The bandwidth transforming node can also offer data bandwidth to the subscriber in preassigned increments. Additionally, the bandwidth transforming node lends itself to efficient upgrading that can be performed entirely on the network side. The bandwidth transforming node can also provide high speed symmetrical data transmission. Further, the bandwidth transforming node can increase upstream and downstream bandwidth and transmission speed by propagating data signals at different wavelengths.

Abstract: A communications network for a metropolitan area is disclosed. The network is comprised of three basic types of nodes: an access multiplexer, a photonic switch, and a core node. The access multiplexer provides multiplexing of data packets from end-users onto at least one sparse wavelength division multiplexed (SWDM) wavelength. The SWDM wavelengths are carried over fiber cable to the photonic switches, which consolidate these wavelengths into dense wavelength division multiplexed (DWDM) wavelengths for transmission to the core node. The core nodes include a photonic switch (PSX) and a service-aware terabit router core for routing packets within the metropolitan area via the network or out to a long haul network. The photonic switches and core nodes are capable of switching at the wavelength, group of wavelength, and fiber levels.

Abstract: An optical fiber network can include an outdoor laser transceiver node that can be positioned in close proximity to the subscribers of an optical fiber network. The outdoor laser transceiver node does not require active cooling and heating devices that control the temperature surrounding the laser transceiver node. The laser transceiver node can adjust a subscriber's bandwidth on a subscription basis or on an as-needed basis. The laser transceiver node can also offer data bandwidth to the subscriber in preassigned increments. Additionally, the laser transceiver node lends itself to efficient upgrading that can be performed entirely on the network side. The laser transceiver node can also provide high speed symmetrical data transmission. Further, the laser transceiver node can utilize off-the-shelf hardware to generate optical signals such as Fabry-Perot (F-P) laser transmitters, distributed feed back lasers (DFB), or vertical cavity surface emitting lasers (VCSELs).

Abstract: An optical network system includes a central office (CO) comprising an A-band BLS to be injected into a light source for downstream signals, an A-band BLS coupling device for coupling the A-band BLS, a first wavelength-division multiplexer/demultiplexer connected to the A-band BLS coupling device for multiplexing/demultiplexing, and a plurality of first optical transceivers connected to the first wavelength-division multiplexer/demultiplexer; a remote node (RN) comprising a B-band BLS coupling device and a second wavelength-division multiplexer/demultiplexer connected to the B-band BLS coupling device for multiplexing/demultiplexing, and being connected to the CO through an optical fiber; and a plurality of optical network terminations (ONTs) including a plurality of second optical transceivers connected to the second wavelength-division multiplexer/demultiplexer, wherein either the RN or one of the plurality of ONTs further includes a B-band BLS to be injected to a light source for upstream signals.

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: An optical transmitter has a resonance wavelength characteristic that varies with the refractive index of the optical transmitter. The optical transmitter receives a narrow band injected wavelength signal from an incoherent light source. The controller substantially matches a resonant wavelength of the optical transmitter to the wavelength of the injected wavelength signal by changing the refractive index of the optical transmitter to substantially match the resonant wavelength of the optical transmitter and the wavelength of the injected wavelength signal. A detector measures a parameter of the optical transmitter to provide a feedback signal to a controller to determine when the resonant wavelength of the optical transmitter and the wavelength of the injected wavelength signal are substantially matched.

Abstract: A modification to a cable modem termination system (CMTS) can include instructing the CMTS to ignore or skip steps of its timing algorithm so that upstream cable modem signals are controlled only by the upstream protocol of the optical network system. According to another exemplary aspect, a time stamp can be added to the upstream cable modem signals so that the CTMS timing scheme can be used. This time stamp can be used in the data service hub to adjust for the delays that occur while the upstream cable modem signals are sent across the optical network. Another adjustment of the CMTS timing scheme can include using less than a total number of miniature time slots for upstream cable modem transmissions. According to another exemplary aspect, a cable modem termination system can be positioned within a laser transceiver node or a subscriber optical interface.

Abstract: A method for designing a communication network is provided. First, network demand data is gathered. Network architecture data is also gathered. Based in part on the network demand data and the network architecture data, a network plan is automatically generated.

Abstract: An optical access network method, an optical access network and an optical switch for an optical access network, capable of solving all the three problems in the conventional GE-PON: transmission distance problem, security problem and communication interference problem. The optical access network comprises an OLT, a plurality of ONUs and one or more stages of optical switches, which are connected one another. In the direction from the OLT to the ONU, each frame (packet) transmitted from the OLT to one of the ONUs is checked so that only the destination ONU specified in the frame (packet) is connected to the OLT. In the direction from the ONU to the OLT, a control message transmitted from the OLT to one of the ONUs is checked so that only one ONU which has been given a transmission allowance from the OLT is connected to the OLT with respect to each frame (packet).

Abstract: A method of automatically generating a computer based layout of an optical communication network is provided. First, communications traffic demand forecast data for an optical communication network is received. Network data corresponding to a deployed optical communication network is also received. Thereafter, a network plan can be automatically generated. The network plan corresponds to a modified network that may be deployed. Also, the network plan can be derived from the network data. Further, the network plan can be constructed in response to the performance of a grooming operation that includes a first level of grooming at an optical level of the modified network and a second level of grooming at an electrical level of the modified network.

Abstract: A system and method are described for integrating a fiber optic fixed access network and a fiber optic radio access network. At least one radio unit transmits and receives communications with at least one mobile unit. A first multiplexer transmits and receives the communications with the at least one radio unit and fixed access communications with at least one fixed access subscriber. The first multiplexer is connected to each of the at least one radio unit and to each of the at least one fixed access subscriber using fiber optic connections. Each of the at least one radio unit transmits and receives the communications with the first multiplexer using a wavelength that is different for each of the at least one radio unit and different from that used to transmit and receive the fixed access communications from the at least one fixed access subscriber.

Abstract: A communication system includes a plurality of nodes and a plurality of point-to-point links that interconnect the plurality of nodes into a network. Each node includes an optical switch to controllably route a plurality of in-ports of the optical switch into a plurality of out-ports of the optical switch. Each point-to-point link includes a free space optical channel. A first free space optical channel couples to a first node through a receive path and through a transmit path. The receive path couples to a respective in-port of the optical switch of the first node, and the transmit path coupled to a respective out-port of the optical switch of the first node. In an alternative embodiment, a communication hub includes a plurality of neighborhood links, and a trunk coupled between the optical switch and a free space optical channel link to the network.

Abstract: A dual structure for a multiplexing section extended to an OSU is obtained without adding a dynamic function, such as an optical switch, to a W-MULDEM. The W-MULDEM of an optical wavelength division multiplexing access system divides, among ports corresponding to the individual ONUs, downstream optical signals having wavelengths ?d1 to ?dn, which are received along a current-use optical fiber, or downstream optical signals having wavelengths ?d1+?? to ?dn+??, which are received along a redundant optical fiber. The W-MULDEM also multiplexes, for the port that corresponds to the current-use optical fiber or the redundant optical fiber, upstream optical signals having wavelengths ?u1 to ?un or wavelengths ?u1+?? to ?un+??, which are received along optical fibers corresponding to the ONUs. A wavelength difference between the downstream optical signal and the upstream optical signal that are consonant with each ONU is defined as an integer times the FSR of an AWG.

Abstract: A WDM network (R) comprises an optical fiber (F) connected to a hub (H) via an input of a demultiplexer (DX) having N outputs to communications stations (Si-Sn) able to deliver and/or receive spectral multiplexes of modulated optical signals with different wavelengths, via coupling means (CP, CP?, MXB). The communications stations (Sn?1) are adapted to deliver spectral multiplexes of modulated optical signals from a given one of P disjoint bands of wavelengths. At least one of the coupling means (MXB) is a 2×1 band multiplexer comprising i) an output connected to a downstream portion of the optical fiber (F), ii) a first input connected to one of the stations (then referred to as the “primary” station) and adapted to its band of wavelengths, and iii) a second input connected to an upstream portion of the optical fiber (F) and adapted to channels having wavelengths different from those of the channels passing through the first input.

Abstract: There are provided fiber optic local convergence points (“LCPs”) adapted for use with multiple dwelling units (“MDUs”) that facilitate relatively easy installation and/or optical connectivity to a relatively large number of subscribers. The LCP includes a housing mounted to a surface, such as a wall, and a cable assembly with a connector end to be optically connected to a distribution cable and a splitter end to be located within the housing. The splitter end includes at least one splitter and a plurality of subscriber receptacles to which subscriber cables may be optically connected. The splitter end of the cable assembly of the LCP may also include a splice tray assembly and/or a fiber optic routing guide. Furthermore, a fiber distribution terminal (“FDT”) may be provided along the subscriber cable to facilitate installation of the fiber optic network within the MDU.

Abstract: Disclosed is a loop-back optical network terminal using a Febry-Perot laser diode as an active type optical modulator in a wavelength division multiplexing based optical network. In addition, a wavelength division multiplexing based optical network having the same is disclosed.

Abstract: A symmetrical capacity network may be adapted to accommodate asymmetrical network traffic patterns by deploying Protected Dedicated Wavelengths (PDWs) between one or more head-end nodes and the access nodes on a ring-based topology network. The PDWs include pairs of wavelengths extending in opposite directions around the fibers forming the original ring and terminating at the intended access node. The pairs of wavelengths form unidirectional working and protection paths from the head-end node to the intended access nodes. By deploying the symmetric capacity and asymmetric capacity on the same platform within the head-end node, it is possible to apply policy across the network resources to allow traffic flows to be selectively placed on the most appropriate network resource.

Abstract: The present invention relates to a Cable Television (CATV) that includes a head end with a radio-frequency hub and an Ethernet hub to separately process data transmitted within the CATV. Specifically, the radio-frequency hub receives the data, extracts radio-frequency data therefrom, outputs the extracted radio-frequency data, and transmits the data to the Ethernet hub, which is external to the radio-frequency hub. The Ethernet hub receives the data from the radio-frequency hub, extracts Ethernet data from the data, outputs the extracted Ethernet data to an Ethernet data port, inputs additional Ethernet data from the Ethernet data port, incorporates the additional Ethernet data into the data, and transmits the data, with the additional Ethernet data incorporated therein, to a receiver.

Abstract: An apparatus for measuring Optical Beat Interference (OBI) noise is applied to a central office in a Subcarrier Multiple Access (SCMA) optical network. The central office includes an optical receiver for converting an optical signal received through an optical fiber into an electrical signal. The OBI noise measurement apparatus includes a power divider, first and second filters, and a power measurement unit. The power divider divides the power of a signal output from the optical receiver into two signals. The first filter passes one of the two signals divided by the power divider in a low band of frequencies below a band of subcarrier signals. The second filter passes the other of the two signals divided by the power divider in a high band of frequencies above the band of subcarrier signals. The power measurement unit measures the power of each signal passed through the first and second filters.

Abstract: Provided are an optical transmission apparatus and method using a light source for wavelength division multiplexing (WDM) optical communication that employs a Fabry-Perot laser diode (F-P LD) whose output wavelength is locked by an externally injected incoherent light, a multifiber, and a waveguide grating router.

Abstract: An optical communication network using a communication system which is combined optical time-division multiplexing and optical wavelength-division multiplexing. The electric/optical converter converts an electric signal strings, which are input from the outside, into optical burst signals by selectively using a plurality of types of optical wavelengths. The network controller controls the optical wavelength selected by the electric/optical converter and the output timing of the optical burst signals for each one of the optical burst signals so that the optical burst signals received by the OLT are time-division multiplexed and wavelength-division multiplexed. By combining optical time-division multiplexing and optical wavelength-division multiplexing, an optical communication network of which the transmission band is wider than a TDMA system can be provided with a lower cost and lower facility scale than a WDM system.

Abstract: A system for communication of signals between remote devices and monitoring and control devices via fiber. The system in accordance with one aspect of the invention includes a plurality of remote interface units each coupled to a corresponding one of the remote devices, a base unit coupled to one or more monitoring devices and one or more control devices, and a central hub coupled between the base unit and the plurality of remote interface units. The central hub is coupled to the base unit by a first fiber optic link, and is coupled to the remote interface units by additional fiber optic links.

Abstract: Provided are a passive optical network system and a method of transmitting a broadcasting signal in the same system. A central office (CO) generates a broadcasting signal and a downstream optical data signal using a coding method guaranteeing a run-length, multiplexes the downstream optical data signal and the broadcasting signal, and transmits the multiplexed downstream optical data signal and broadcasting signal. A remote node (RN) transmits the multiplexed downstream optical data signal and broadcasting signal received from the CO to one or more optical network units (ONUs). A gain medium, which is located on a transmission line between the CO and the RN, amplifies the broadcasting signal using the downstream optical data signal as a pump light source. Accordingly, a high gain can be obtained by amplifying the broadcasting signal using the gain medium located on the transmission line without a separate pump light source.

Abstract: Various methods, systems, and apparatuses is described in which a passive-opticalnetwork includes a first multiplexer/demultiplexer, a second multiplexer/demultiplexer, a wavelength tracking component, and a transmission wavelength controller. The first multiplexer/demultiplexer is located in a first location. The second multiplexer/demultiplexer is located in a second location remote from the first location. The wavelength tracking component determines the difference between the transmission band of wavelengths of the first multiplexer/demultiplexer and the second multiplexer/demultiplexer to provide a control signal to match the transmission band of wavelengths of the first multiplexer/demultiplexer and the second multiplexer/demultiplexer. The transmission wavelength controller alters an operating parameter of the first multiplexer/demultiplexer based on the control signal to control the transmission band of wavelengths of the first multiplexer/demultiplexer.

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: An apparatus and system are provided for delivering communication services such as video, data and telephony services to individual residential units. According to one embodiment, an optical network terminal (ONT) for providing communication services to a single residential unit comprises a passive optical network interface (PI) circuit, a residential service interface (RSI) circuit, and a power unit. The PI circuit receives optical signals from an optical fiber and transmits optical signals onto the optical fiber. The PI circuit is adapted to convert received optical signals containing voice information to electrical voice ATM cells, received optical signals containing data information to electrical data ATM cells, and received optical signals containing video signals to electrical video signals. The PI circuit is also adapted to convert electrical voice ATM cells and electrical data ATM cells to optical signals for transmission over the optical fiber.

Abstract: A return path system includes inserting RF packets between regular upstream data packets, where the data packets are generated by communication devices such as a computer or internet telephone. The RF packets can be derived from analog RF signals that are produced by legacy video service terminals. In this way, the present invention can provide an RF return path for legacy terminals that shares a return path for regular data packets in an optical network architecture.

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: An optical wavelength division multiplexing network has a multi-level structure where a plurality of optical network units (ONUs) are connected to a lowest-level network. A node apparatus connected to networks other than the lowest-level network includes (a) passive optical components to branch optical signals from a higher-level network to a lower-level network, and couple optical signals from the lower-level network to the higher-level network, and (b) optical amplifiers for the optical signals. A node apparatus connected to the lowest-level network includes (a) an optical multiplexer/de-multiplexer to de-multiplex optical signals from the higher-level network, selectively output an optical signal to each ONU, and multiplex wave-length specific optical signals from the ONUs into a multiplexed optical signal, and (b) optical amplifiers for the optical signals.

Abstract: A cable television (CATV) distribution system, and a method of forming and using the CATV distribution system. In a first embodiment, a narrowcast optical signal is generated by an uncooled laser and converted by a receiver into a narrowcast electrical signal. In a second embodiment, a narrowcast optical signal generated by an uncooled laser is combined with a broadcast optical signal by an optical coupler at a hub of the CATV distribution system to generate a composite optical signal, which at a CATV node is: split into the broadcast and narrowcast optical components, respectively converted into broadcast and narrowcast electrical components, and combined into a composite electrical signal. In a third embodiment, a narrowcast optical signal is generated by an uncooled laser and then combined with the broadcast optical signal by a single receiver.

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: An optical channel monitor assembly for simultaneously measuring the optical power levels of multiple series of dense wavelength division multiplexed channels or the like traveling on separate optical fibers in an optical communications system includes an arrayed waveguide grating router having a first side and a second side, the first side including a first plurality of ports and the second side including a second plurality of ports, the first plurality of ports in optical communication with the second plurality of ports, wherein the first side includes a first input port for collectively receiving a first series of optical channels, wherein the second side includes a first plurality of output ports for individually delivering the first series of optical channels, wherein the second side includes a second input port for collectively receiving a second series of optical channels, and wherein the first side includes a second plurality of output ports for individually delivering the second series of optical cha

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: A MAC (Medium Access Control) control block for controlling transmission of data between a plurality of MAC clients and a plurality of MACs in an Ethernet passive optical network (EPON) is provided. The MAC control block includes the plurality of MAC clients and the plurality of MACs associated with the MAC clients for forming a frame for data transmission; a plurality of optical multipoint (OMP) blocks connected between the MAC clients and the MACs for implementing a multipoint control protocol (MPCP); and a multipoint gating control block for controlling the OMP blocks so that when any one of the OMP blocks is transmitting the data, the other OMP blocks are prevented from transmitting data.

Abstract: A MAC (Medium Access Control) control block for controlling transmission of data between a plurality of MAC clients and a plurality of MACs in an Ethernet passive optical network (EPON) is provided. The MAC control block includes the plurality of MAC clients and the plurality of MACs associated with the MAC clients for forming a frame for data transmission; a plurality of optical multipoint (OMP) blocks connected between the MAC clients and the MACs for implementing a multipoint control protocol (MPCP); and a multipoint gating control block for controlling the OMP blocks so that when any one of the OMP blocks is transmitting the data, the other OMP blocks are prevented from transmitting data.

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: 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: A method and system for conveying contextually relevant information to a wireless client are disclosed. More particularly, a transmitter transmits a diffuse infrared signal to a client having an IrDA compliant communication interface. The transmitter communicates with the client by making a link layer in the transmitter compliant with an IrDA link layer running on the client. To perform communication, data is received at the transmitter from a service provider. The data is formatted into an IrDA compliant diffuse infrared signal and transmitted to the client. The client receives the data and parses it to extract contextually relevant information contained therein. The client may reply to the transmitter if a user of the client is interested in a service offered by the service provider. If the service provider receives a reply from the client, the service is made available to client.

Abstract: A cable television system (100) having forward and reverse paths includes, in the reverse path, a digital optical transmitter (200) for receiving an RF signal, converting it to a digital signal, and adding a digital pilot tone thereto. A laser is driven in accordance with the summed digital signal to generate a digital optical signal representative of the pilot tone and the RF signal. The cable television system (100) also includes an optical receiver (305) for receiving the digital optical signal and recovering therefrom the RF signal and the pilot tone. The optical transmitter (200) and receiver (305) are coupled by fiber optic communication media (110).

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.