Abstract: Disclosed are a system and a method for controlling multicast data. The system may comprise: a plurality of transceivers, each of which comprises a laser configured to generate an optical carrier, the generated optical carrier being modulated by electrical downstream p-t-p data so as to generate optical downstream p-t-p IRZ signal; a PM configured to modulate the generated optical downstream p-t-p IRZ signal by electrical multicast data so as to generate orthogonally modulated signal; and a DI configured to demodulate the orthogonally modulated data and has a frequency response peak or dip in response to the demodulating, wherein an offset of a laser center wavelength of the laser from the frequency response peak or dip is adjustable so as to selectively enable or disable the multicast data.

Abstract: Provided are methods of transmitting and receiving a multicast or broadcast frame in an optical line terminal (OLT) and an optical network unit (ONU) for a wavelength division multiplexing (WDM)-passive optical network (PON), a WDM-PON system, and an OLT for a WDM-PON. The method of transmitting a multicast or broadcast frame in an OLT for a WDM-PON includes converting and splitting a multicast or broadcast frame input using a single wavelength into a plurality of wavelengths, combining the split wavelengths, and outputting the multicast or broadcast frame. In this way, a multicast or broadcast frame can be transmitted and received, thereby providing a single copy broadcast (SCB) function in a WDM-PON.

Abstract: Various methods and apparatuses are described for a wavelength division multiplexing passive optical network (WDM-PON) that performs bi-directional communication. The WDM-PON may include two or more remote distribution nodes in between a central office and the most distant optical network unit. Each remote distribution node is located in a physically separate location. A first remote distribution node has two or more optical network units connected to the first remote distribution node. Each remote node separates one or more wavelength channels from a composite optical signal distributed through that remote distribution node.

Abstract: An apparatus for managing an optical signal includes a system optics card including an add filter, a drop filter, electrical backplane connector, and a mechanical front panel including express input and output ports providing channels to other system optics cards. The card transports information over a first optical transport link and receives information over a second optical transport link. The card identifies at least one network channel on the second optical transport link destined for a client device. The drop filter delivers the identified network channel to the optical converter card for delivery to the client device. The add filter receives client channels from the optical converter card generated by the client device. The card also transports the client channels of the client device over the first optical transport link. The electrical backplane connector is connectable to a chassis for housing the system optics cards and other system optics cards and/or other optics cards.

Abstract: A system for supporting wavelength management in a passive optical network (PON), comprising an optical line terminal (OLT) configured to send an wavelength assignment for optical network unit (ONU) communications based on a wavelength tunability capability, and an ONU coupled to the OLT and configured to send the wavelength tunability capability to the OLT, wherein the wavelength assignment and the wavelength tunability capability are sent in media access control (MAC) messages. Also disclosed is an apparatus of an OLT for supporting wavelength management, comprising one or more component configured to couple to an ONU and exchange a wavelength assignment for transmission with the ONU based on a wavelength tunability of the ONU, wherein the wavelength indication and the wavelength tunability are exchanged via MAC layer frames.

Abstract: An apparatus of a passive optical network (PON) comprising an optical line terminal (OLT) component configured to couple to an optical network unit (ONU) and send downstream wavelength identification to the ONU to indicate a wavelength that corresponds to the ONU, wherein the downstream wavelength identification is transmitted using a Media Access Control (MAC) layer frame for an embedded channel, a control message channel, or a data channel. Also included is an apparatus of a PON comprising an ONU component configured to couple to an OLT and send upstream wavelength feedback to the OLT to indicate a wavelength that corresponds to the ONU, wherein the upstream wavelength feedback is transmitted using a MAC layer frame for an embedded channel, a control message channel, or a data channel.

Abstract: A passive optical network (PON) comprises an Optical Line Termination (OLT), an Optical Distribution Network (ODN), and a plurality of Optical Network Terminations (ONTs), wherein the OLT includes an OLT Dense Wavelength Division Multiplexing (DWDM) multiplexer, an OLT CWDM demultiplexer, and a Wavelength Division Multiplexing (WDM) filter, wherein the OLT DWDM multiplexer and the OLT CWDM demultiplexer are coupled to the WDM filter, wherein the ODN includes a WDM filter, a DWDM demultiplexer, and a plurality of fanout splitters, wherein the DWDM demultiplexer is coupled to the WDM filter, wherein the WDM filters are coupled to one another and wherein a portion of the plurality of ONTs that are associated with a wavelength are coupled to one of fanout splitters that is associated with the wavelength.

Abstract: An optical transceiver may include an optical fiber coupling assembly for coupling optical fibers to transmitter and receiver sub-assemblies to increase the number of usable channel wavelengths by reducing an incident angle on a WDM filter without causing unwanted back reflection to a laser. In one example, the optical fiber coupling assembly may be used to increase the number of usable channel wavelengths between the L-band and the C-band. The optical transceiver may be used, for example, in an optical line terminal (OLT) and/or optical networking unit (ONU) in a wavelength division multiplexed (WDM) passive optical network (PON) capable of transmitting and receiving optical signals on multiple channel wavelengths.

Abstract: The subject matter disclosed herein relates to synchronizing network timing. In one particular example, network timing may be synchronized using reflected signals.

Abstract: One or more overlay wavelengths are applied to a GPON architecture to provide sufficient, cost-effective forward bandwidth per home for targeted, unique narrowcast services to allow traditional HFC operators to use a PON architecture with their existing HFC equipment. A separate return path capability using a separate coaxial cable with RF signals to the GPON may also be used. This return capability may be provided either by a fiber optic link or coaxial link from the home.

Abstract: A large communication network suitable for nationwide or worldwide utilization. The present invention overthrows the conventional packet switching technologies with an all-optical network. The invention uses tunable laser sources to generate large number of highly stable narrow-band optical signals, each serving as a communication channel. With packet processing replaced by all-optical channels, the network become highly secure and scalable while harnessing the virtually unlimited capacity of fiber-optic. A large number of nodes (called area code nodes) are connected with all-fiber-optic links with all-optical switches. A routing algorithm provides one or more communication links from each area code node to every other area code node so that information never has to change carrier wavelength as it travels the network. Each area code node contains circuits that are provided to connect individual users to the network.

Abstract: Embodiments of the present invention are directed to optical broadcast systems. The nodes of the system can be any combination of cores, caches, input/output devices, and memory, or any other information processing, transmitting, or storing device. The optical broadcast system includes an optical broadcast bus. Any node of the system in optical communication with the broadcast bus can broadcast information in optical signals to all other nodes in optical communication with the broadcast bus.

Abstract: Methods and apparatuses to provide an “Open access” service model using wavelength division multiplexing (“WDM”) passive optical networks (“PONs”) are described. A cross-connect is used to supply a first set of optical signals corresponding to a first service provider and a second set of optical signals corresponding to a second service provider to a WDM multiplexer/demultiplexer. The WDM multiplexer/de-multiplexer is used to multiplex and transmit the first set and the second set to a remote location. Another WDM multiplexer/de-multiplexer at the remote location is used to de-multiplex the first set and the second set. The first set may be supplied to a first user and the second set may be supplied to a second user. Transceivers coupled to the cross-connect may be used to generate the optical signals. For one embodiment, the transceivers include a wavelength-locked light source. For one embodiment, the transceivers are alike.

Abstract: A data center network comprising with an all-optical core network which includes a number of separate all-optical networks to connect clusters of computer network equipment at network nodes. Circuit modules in the data center network each includes a memory bank to provide queues to store information scheduled to be transmitted optically through the all-optical core network. Each circuit module also includes a lambda port module which includes a number of optical mux-demux units and an equal number of lambda ports designed to provide communication between the mux-demux units and the memory bank via a number of optical transceivers. In preferred embodiments all logic communication circuits through the core network are all optical fibers. The present invention creates non-interfering circuits by means of their spectral, spatial and temporal separation from each other.

Abstract: A method and system for encoding and determining labels in a Dual Polarization (DP) Quaternary Phase Shift Keying (QPSK) signal is provided. A label frame, signature sequence, and data payload are combined using a complementary constant-weight code encoding (CCWC) encoder, the output of which is deinterleaved and differentially precoded to generate a polarized tributary of a DP-QPSK signal. This encoding can be duplicated for a second tributary of the DP-QPSK signal. The label can be determined using one or more polarizers and corresponding low-speed photodetectors, each applied to a copy of the DP-QPSK signal. The strongest output of the photodetectors is then used to determine the label. Alternatively, the DP-QPSK signal can be viewed as having XI, XQ, PH, and PV tributaries. These tributaries can then be translated into XI, XQ, YI, and YQ tributaries are encoded into a standard DP-QPSK signal.

Abstract: A system and communication method for the system interconnecting the optical network with the radio communication network is provided. The solution mainly applies to an optical access network employing fiber for transmission and the radio communication network connected to the optical access network, wherein a base station of the radio communication network is connected to the optical access network and communicates to an entity in the optical access network to achieve interconnection between the optical network and the radio communication network. After the interconnection is established, a user equipment can enjoy communication services through the interconnected radio communication network and the optical network.

Abstract: Technologies are generally described for substantially maximizing capacity in a wavelength division multiplexing (WDM) passive optical network (PON). An “achievable rate region” may be defined as a set containing admissible traffic rates of a given WDM PON system such that a volume of an achievable rate region is proportional to a capacity of the network. Deriving the achievable rate region for a particular network, decisions may be made whether incoming traffic rate can or cannot be achieved for that network. Moreover, the achievable rate region may be used to construct a WDM PON utilizing a minimum number of wavelengths, a minimum number of lasers with narrowest tuning ranges, and a minimum number of receivers, thereby reducing a capital expenditure in building the PON system.

Abstract: An optical line terminal calculates a requirement threshold for each optical subscriber unit based on a difference between the time average allocated bandwidth of each optical subscriber unit and the target bandwidth, and notifies a corresponding optical subscriber unit of the calculated requirement threshold. The corresponding optical subscriber unit then notifies, based on the data amount accumulated in a buffer, the optical line terminal of a data amount, as a transmission requirement, up to a data separation that is less or equal to the notified requirement threshold and in which a maximum transmission amount can be transmitted. The optical line terminal then notifies the corresponding optical subscriber unit of a transmission permission amount in which the data equal to the transmission requirement of which the optical line terminal is notified can be transmitted. The corresponding optical subscriber unit then transmits the data amount corresponding to the transmission permission amount.

Abstract: An optical transmission system is provided. The optical transmission system includes a user side optical repeater device, a central office side optical repeater device, and wavelength multiplexing and wavelength de-multiplexing functions. The user side optical repeater device is to be connected with a user side optical network unit, transmits data in two ways, and is used for wavelength division multiplexing. The central office side optical repeater device is to be connected with a central office side optical line terminal, transmits data in two ways, and is used for wavelength division multiplexing. The wavelength multiplexing and wavelength de-multiplexing functions are used for relaying between the user side optical repeater device and the central office side optical repeater device.

Abstract: Optical networks interconnect a plurality of optical network units (ONUs) to an optical line terminal (OLT). The OLT comprises a plurality of optical transceivers that are wavelength division multiplexed and connected to a WDM metro network. The metro network is configured to facilitate communication of a plurality of wavelengths between the OLT and local nodes, the local nodes including a wavelength sharing network configured to connect at least one of the wavelengths communicated with the OLT to a plurality of feeder fibers. The feeder fibers connect the wavelength sharing network to remote nodes that comprise WDM devices that have pluralities of output ports. An optical combiner allows the first and second ONUs to share the same transceiver in the OLT.

Abstract: The present invention discloses a low-cost light source for optical transmission systems and optical networks based on wavelength-division multiplexing (WDM) technology. A light source in accordance with the present invention is implemented by externally injecting a narrow-band incoherent light into a Fabry-Perot laser diode (F-P LD). After injection of narrow-band incoherent light, the output of F-P LD becomes wavelength-selective rather than multi-mode and the output wavelength of F-P LD coincide with the peak wavelength of the injected incoherent light. Multi-channel WDM light sources according to the present invention can be implemented using a single broadband incoherent light source and plurality of F-P LDs. An optical transmission system for upstream signal transmission in an passive optical network using the light source according the present invention is also disclosed.

Abstract: A passive optical network couples a WDM optical line terminal (“OLT”) to WDM optical network units (“ONUs”). The WDM OLT includes an optical transmitter array with coherent transmitters to generate downstream WDM signals encoded using phase modulation, an optical receiver array with direct detection photo-detectors to receive upstream WDM signals encoded with amplitude modulation, and an optical diplexer optically coupled to the optical transmitter array and the optical receiver array. The WDM ONU includes a tunable optical transmitter having a first tunable laser source coupled to generate a selectable upstream carrier wavelength and direct amplitude modulation circuitry coupled to amplitude modulate the first tunable laser source and a tunable optical receiver having coherent detection circuitry to demodulate phase information from the downstream WDM signals and a second tunable laser source operated as a local oscillator and coupled to tune to a selectable downstream carrier wavelength.

Abstract: In the manufacture and application of a PLC-ECL type wavelength tunable light source, provided is a wavelength tunable mechanism with improved performance and stability, a light source with improved packaging performance and mass productivity, and a light source applied to a WDM-PON with initialization and stabilization functions. The wavelength tunable light source having a PLC (planar lightwave circuit)-ECL (external cavity laser) structure includes a first housing in which a semiconductor optical gain medium is mounted, a second housing in which a PLC device is mounted, and a third housing in which an optical fiber is mounted. The first, second, and third housings make an optical axis alignment through an optical coupling lens and combined in a laser welding method.

Abstract: The disclosure provides a long-distance box and a method for processing uplink light and downlink light of the long-distance box, uplink light and downlink light from different Passive Optical Network (PON) systems are split, the uplink light from the different PON systems is transmitted through a first optical path, and the downlink light from the different PON systems is transmitted through a second optical path; wherein the uplink light from the different PON systems is amplified by an Optical Amplifier (OA) and then output to Optical Line Terminals (OLT) of respective systems; the downlink light from different PON systems with the different wavelengths is transmitted through different optical sub-paths of the second optical path according to the wavelengths of the downlink light, and the downlink light is amplified by different Optical-Electrical-Optical (OEO) conversion devices on the different optical sub-paths and then output to Optical Network Units (ONUs) of the respective systems.

Abstract: A wavelength routing system includes a plurality of nodes (1, 2, 3, 4) and an array waveguide grating (40) having a routing property and optically connected to the plurality of nodes. Each of the nodes has a plurality of light sources (TLS) outputting lights at different wavelengths to the array waveguide grating, respectively, and a wavelength demultiplexer (125, 225, 325, 425) having a periodic property, demultiplexing a light output from the array waveguide grating, and outputting demultiplexed lights. The wavelength demultiplexer is set a channel period which is different from that of the array waveguide, and which is more than or equal to a number of output ports of the wavelength demultiplexer.

Abstract: When a frame is received from one of PON ports 12a to 12c of ONUs 1a to 1c, an OLT 3 compares VPIDs contained in Preamble/SFD regions A of the received Ethernet® frame with VPIDs assigned to LAN ports 31 and 32 of the OLT 3. Upon coincidence, a PON MAC process is started. When a frame is received from a PON port 33 of the OLT 3, each of the ONUs 1a to 1c compares a VPID contained in a Preamble/SFD region of the received Ethernet® frame with VPIDs assigned to the ONUs 1a to 1c. Upon coincidence, a PON MAC process is started.

Abstract: A method and apparatus for implementing a hybrid SOA-Raman amplifier in a central office in order to enable multiple passive optical networks to share one or more enhancement service sources, e.g., to share a source for a broadcast service are disclosed.

Abstract: A Wavelength Division Multiplexed Passive Optical Network (WDM-PON) includes an Optical Line Terminal (OLT) including a first Arrayed Waveguide Grating (AWG) MUX/DEMUX, and a remote node including a second AWG MUX/DEMUX. Each AWG MUX/DEMUX has at least two input ports for receiving a respective wavelength division multiplexed optical signal, and a plurality of output ports. Each output port of the Optical Line Terminal AWG MUX/DEMUX is coupled to a respective transceiver of the OLT. Each output port of the remote node AWG MUX/DEMUX is coupled to a respective PON having at least one optical network terminal (ONT). Respective first and second optical paths are coupled between corresponding input ports of the first and second AWG MUX/DEMUXs. Means are provided for sourcing seed light of the WDM-PON into a selected one the first and second optical paths.

Abstract: An optical hybrid circuit includes a multimode interference coupler; a first 2:2 optical coupler; a second 2:2 optical coupler; a third 2:2 optical coupler; and a phase controlling region. The first 2:2 optical coupler, the second 2:2 optical coupler, and the third 2:2 optical coupler are coupled to one of the pair of first output channels, the pair of second output channels, the pair of third output channels, and the pair of fourth output channels of the multimode interference coupler. The phase controlling region is provided in one or both of each pair of at least two pairs of output channels from among three pairs of output channels to which the first 2:2 optical coupler, the second 2:2 optical coupler, and the third 2:2 optical coupler are coupled, respectively.

Abstract: Disclosed is a wavelength division multiplexing passive optical network for simultaneously providing a broadcasting service and a data service by employing a broadband light source, which uses mutually injected Fabry-Perot laser diodes, as well as a central office used for the same.

Abstract: A network component comprising at least one processor configured to implement a method comprising transmitting a request to compute a routing assignment, a wavelength assignment, or both for a signal in a wavelength switched optical network, wherein the request comprises a lightpath constraint and wherein the request is transmitted using a path computation element protocol. Also disclosed is a network comprising a first path computation element (PCE) and a path computation client (PCC) in communication with the PCE, wherein the PCC is configured to send a request to and receive a reply from the PCE using a PCE protocol, wherein the request comprises a lightpath constraint. Included is a method comprising sending a discovery advertisement to the at least one PCE that calculates a wavelength assignment, receiving a response comprising a PCE capability information from the PCE, wherein the request and the reply are communicated via a PCE protocol.

Abstract: An aggregation node device of a passive optical network (PON) is provided which includes an aggregation optical line terminal (OLT) and an aggregation optical network unit (ONU). The aggregation OLT is connected to a user-side ONU. The aggregation OLT aggregates service data transmitted by a user-side ONU and transmits the aggregated service data to the aggregation ONU. The aggregation ONU is adapted to transmit the received aggregated service data to a network-side OLT. A PON system is further provided. The device and system can not only support the conventional time division multiplexing (TDM) services but also support the services based on variable-length packets and the multicast service. Moreover, it is not necessary to build an equipment room and supply power for an intermediate optical distribution network (ODN) which greatly reduces the network construction and operation costs.

Abstract: A quantum key distribution system is deployed in an optical fiber network transporting classical data traffic. A source of entangled photon pairs is used to generate quantum keys. Classical data traffic is typically transported over channels in the C-band. If a pair of channels for transport of quantum data is available within the C-band, then the source of entangled photon pairs is tuned to emit in a pair of channels in the C-band. If a pair of channels for transport of quantum data is not available within the C-band, then the source of entangled photon pairs is tuned to emit in a pair of channels in a combined S-band and L-band. When a periodically-poled lithium niobate waveguide pumped with a laser is used for the source of entangled photon pairs, the output spectral properties are tuned by varying the temperature of the waveguide.

Abstract: An optical hybrid circuit includes a MMI coupler including a pair of input channels provided at positions symmetrical with respect to a center position in a widthwise direction thereof, a pair of first output channels outputting a pair of first optical signals having an in-phase relationship, and a pair of second output channels neighboring with each other outputting a pair of second optical signals having an in-phase relationship. The MMI coupler converts QPSK signal light or DQPSK signal light into the pair of first optical signals and the pair of second optical signals having an in-phase relationship. The optical hybrid circuit includes a 2:2 optical coupler connected to the first or the second output channels. The 2:2 optical coupler converts the pair of first optical signals or the pair of second optical signals into a pair of third optical signals having a quadrature phase relationship with the pair of first or second optical signals.

Abstract: A system for managing radio access resources includes a joint radio resource management/transport resource management unit configured to communicate with a plurality of radio units over a transport network, to jointly allocate radio resources at the radio unit and transport resources on the transport network in response to requests from wireless terminals requesting access to radio resources from the radio units, to send a radio resource allocation schedule to the plurality of radio units that defines radio resource allocations for the wireless terminals, and to generate a transport resource allocation schedule that defines transport resource allocations for the wireless terminals. The system further includes a transport resource controller configured to receive the transport resource allocation schedule and to map user data to physical transport resources on the transport network in response to the transport resource allocation schedule.

Abstract: In some variations, the present invention provides a method for forming a chip-scale photonic frequency channelizer or spectrum analyzer. A low-loss waveguide forms a long delay-line in a first level, from which a large number of filter-taps form narrow channel passbands. Multi-dimensional laser-written waveguides feed a slab waveguide coupler located at a stacked, second level. A chip-scale RF-photonic spectrum analyzer provided by this invention has extremely high resolution, such as a passband width of about 30 MHz over a free spectral range of 12 GHz, while occupying a device footprint of only about 10 cm2 area.

Abstract: Various example embodiments are disclosed. According to an example embodiment, a method may include receiving a resource request for optical resources within a wavelength division multiplexed (WDM) optical network; comparing one or more parameters of the resource request to a list of pre-validated paths for the WDM optical network, each pre-validated path identifying an optically feasible label switched path between a source node and a destination node; determining that there is a pre-validated path on the list that matches the one or more parameters of the optical resource request; and sending a message to request a reservation of resources along the matching pre-validated path.

Abstract: In a PON system with WDM, at the time of initial setting, each ONU negotiates with an OLT, and automatically acquires a wavelength which can be used by the ONU. One wavelength for negotiation of assigned wavelength is fixed as a default, and a newly connected ONU first uses the wavelength. The OLT 200 includes a plurality of light sources for downstream communication. The ONU 300 includes a wavelength variable filter selectively receiving one of wavelengths of downstream communication, and a wavelength variable light source selectively emitting light of one of plural wavelengths for upstream communication. The ONU 300 uses a transmission wavelength (for example, ?u32) for negotiation and transmits a wavelength assignment request 1000 to the OLT 200. The OLT 200 selects a wavelength ?u1 to be assigned from unused wavelengths, and transmits wavelength information to the ONU 300. The OLT 200 and the ONU 300 communicates using the notified wavelengths.

Abstract: Provided is a point-to-multipoint optical communication system capable of extending a transmission distance between a subscriber apparatus and a station apparatus without changing wavelengths of an upstream optical signal and a downstream optical signal, which are used in both of the apparatuses. The point-to-multipoint optical communication system includes, as a basic configuration thereof, an optical network for connecting one station apparatus (1) to a plurality of (n) subscriber apparatuses (4). Among m basic configurations, one station-side wavelength multiplexer/demultiplexer (22), one optical fiber transmission line (30), and one subscriber-side wavelength multiplexer/demultiplexer (12) are shared. The point-to-multipoint optical communication system further includes a station-side repeating unit (20) and a subscriber-side repeating unit (10) each including the one wavelength multiplexer/demultiplexer (22 or 12) and m wavelength converters (21 or 11).

Abstract: The present invention discloses a transmission device of a low-noise optical signal having a low-noise multi-wavelength light source, a transmission device of broadcast signals using a low-noise multi-wavelength light source, and an optical access network having the same. The present invention uses a low-noise multi-wavelength light source (LMLS) which has sufficiently low noises at respective wavelengths, while being lasing at a multi-wavelength. Noises at respective wavelengths are not increased, even though an output light of such an LMLS passes through a wavelength division multiplexer/demultiplexer (a tunable optical filter or an arrayed waveguide grating (AWG), etc.). When using an LMLS, it is possible to embody an optical access network capable of transmitting optical signals at a high-speed and simultaneously transmitting a multicast signal. Further, when embodying an optical amplifier by using a gain medium for an LMLS, it is possible to obtain gain at a broad band without cross-coupling.

Abstract: An optical communicating apparatus that is connected to another optical communicating apparatus by a two-core optical transmission path includes: a one-core optical transmission path that passes an optical signal transmitted from an optical transmitter/receiver performing one-core bilateral communication and an optical signal transmitted to the optical transmitter/receiver in an opposite direction; a transmitting unit that transmits the optical signal transmitted from the optical transmitter/receiver through the one-core optical transmission path, to the other optical communicating apparatus through a first core of the two-core optical transmission path; and a receiving unit that receives the optical signal transmitted from the other communicating apparatus through a second core of the two-core optical transmission path, and passes the received optical signal to the one-core optical transmission path.

Abstract: In accordance with the present disclosure, a method of configuring a wavelength division multiplexed (WDM) network is presented. The WDM network includes circuits that carry optical signals, with each signal corresponding to a wavelength. The WDM network includes nodes, with links connecting the nodes to one another. Each circuit includes at least one link and at least one node. The method comprises assigning each of the circuits to an optical signal, based on first and second criteria, and configuring the nodes based on the assignment.

Abstract: A PON station side apparatus is provided with a selection section and a receiving section. For multiple data transferred from multiple PON terminal apparatuses that transmit data at different communication speeds in time division multiplexing, the selection section selects any of the multiple receiving circuits to be a receiving circuit for a receiving destination at which data is received on the basis of the transmission time zones for the data. The receiving section switches the receiving circuit selected by the selection section among the multiple receiving circuits to be the receiving circuit for the destination at which data is received of the data and receives the data through the switched receiving circuit.

Abstract: A passive optical network is provided, which includes an optical central office connected to a line termination device by a branch of the network including a passive amplification medium. The central office is adapted to send/receive a first data optical signal and has a first amplifier for sending a second amplification optical signal. The second signal exciting the amplification medium to amplify the optical power of an optical signal. The line termination device is adapted to receive the first optical signal, modulate the second amplification optical signal; and inject the modulated second signal into the network.

Abstract: A data communications network includes N nodes, where N is an integer greater than one, and a star coupler coupled to each of the N nodes. Each node includes a transmitter and a receiver. The star coupler is configured to receive, in parallel, data streams transmitted from a plurality of the N nodes, and to passively retransmit, in parallel, each of the received data streams to each node of the N nodes. Each receiver is configured to receive multiple data streams in parallel.

Abstract: A method and apparatus for implementing a hybrid SOA-Raman amplifier in a central office in order to enable multiple passive optical networks to share one or more enhancement service sources, e.g., to share a source for a broadcast service are disclosed.

Abstract: The invention concerns a method as a pre-condition for a gain control of an optical amplifier that amplifies a whole signal out of a multiple of optical signals and where each of these signals includes regular gaps, in which these optical signals are synchronized with respect to each other such that the gaps coincide, as well as a tree-shaped optical access network, a central station, and a terminal.

Abstract: A system and method for data synchronization in Passive Optical Networks are disclosed. According to an embodiment, the present invention provides a method for providing upstream data synchronization in an optical communication network. The method includes sending data from an Optical Network Unit. The data includes a first data frame, which includes a header sequence, a synchronization segment, and a data segment. The synchronization segment includes 66 bits, which includes a first number of bits having nonzero values and a second number of bits having a value of zero. The first number is different from the second number. The method further includes receiving at least the first data frame by an Optical Line Terminal. The method also includes processing the first data frame. The method additionally includes selecting a first segment of the first data frame, the first segment including 66 bits.

Abstract: Provided are a transmission apparatus and a transmission method for a subscriber network in a cable network. A passive optical network (GPON) receiver receives data packets through a fiber line using a plurality of optical wavelengths from a head end. A micro cable modem termination system (CMTS) converts the data packets into a data over cable service interface specification (DOCSIS)-based DOCSIS frame and transmits the DOCSIS frame to at least one subscriber device through a coaxial line.

Abstract: Disclosed are a system and a method for controlling multicast data. The system may comprise: a plurality of transceivers, each of which comprises a laser configured to generate an optical carrier, the generated optical carrier being modulated by electrical downstream p-t-p data so as to generate optical downstream p-t-p IRZ signal; a PM configured to modulate the generated optical downstream p-t-p IRZ signal by electrical multicast data so as to generate orthogonally modulated signal; and a DI configured to demodulate the orthogonally modulated data and has a frequency response peak or dip in response to the demodulating, wherein an offset of a laser center wavelength of the laser from the frequency response peak or dip is adjustable so as to selectively enable or disable the multicast data.