Abstract: In general, techniques are described for inline packet replication in network devices. A network device referred to as an optical line terminal (OLT) may implement the techniques. The OLT comprises a customer interface that supports different logical interfaces to which couple a plurality of optical network terminals (ONTs) and a network interface that receives a data unit. The OLT further comprises a conversion unit, such as a media access control (MAC) module, located in a data path of the optical line terminal that determines whether the received data unit is a candidate for replication. The conversion unit includes an inline packet processing module that performs replication to generate at least one copy of the data unit based on the determination that the received packet is a candidate for packet replication. The customer interface outputs the at least one copy of the data unit to the ONTs.

Abstract: An OLT allocates a bandwidth budget and assigns upstream transmission order by receiving upstream transmission requests from a plurality of ONUs. Each ONU's request includes a requested guaranteed bandwidth and a requested best effort bandwidth. Each ONU has respective first and second attribute values. One attribute is given allocation priority over the other attribute. One attribute is given scheduling priority over the other attribute. Within each attribute, an allocation rank and a transmission rank is assigned to the possible attribute values. The bandwidth budget is allocated in accordance with the allocation priority and ranks. The upstream transmissions are scheduled in accordance with the scheduling priority and ranks.

Abstract: A time synchronization method and a time synchronization device in a passive optical network (PON), and a PON are provided. The method includes receiving a synchronization packet sent after time synchronization of an optical line terminal (OLT) with a master clock (MC) is achieved, wherein the synchronization packet carries a timestamp TMt1i determined after the time synchronization of the OLT is achieved, adjusting a local clock according to the timestamp to achieve time synchronization of an optical network unit/optical network terminal (ONU/ONT) with the OLT, and after the time synchronization of the OLT is achieved, instructing an slave clock (SC) to perform time synchronization. A time synchronization device and a time synchronization system for implementing the method in a PON are further provided.

Abstract: One embodiment provides an EPON for transporting RF signals. The system includes a reference clock, an ONU, and an OLT. The ONU includes a mechanism for receiving a frequency and phase-reference signal from the OLT, a mechanism for receiving an RF signal, an ADC for converting the RF signal into a digital signal using a sampling signal associated with the frequency and phase-reference signal, a mechanism for assembling at least a portion of the digital signal into a packet, a mechanism configured to timestamp the packet, and an optical transceiver. The OLT includes a mechanism for receiving the packet, a buffer, a delay mechanism configured to delay reading the received packet from the buffer for a predetermined amount of time, and a DAC for converting the digital signal included in the packet back to RF domain using a clock signal associated with the frequency and phase-reference signal.

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: There are disclosed techniques for power control in an Optical Network Unit (ONU) of a Passive Optical Network (PON). In one embodiment, the supply of power to an optical transmitter is controlled in accordance with information defining a plurality of transmission windows during which data can be transmitted from the ONU, in order to achieve the following: (1) to provide power to the optical transmitter beginning at a predetermined time in advance of a transmission window to ensure a laser in the optical transmitter is ready to begin transmitting the data at the start of the transmission window; and (2) to refrain from providing full power to the optical transmitter between transmission windows when the duration of time between the transmission windows is greater than a predetermined length.

Abstract: A method for time synchronization on a passive optical network is disclosed, including: an optical line terminal (OLT) receives clock information sent by a first optical network unit (ONU); the OLT adjusts local time of the OLT according to the clock information, to implement clock synchronization between the OLT and the first ONU; the OLT sends the clock information to a second ONU, to implement clock synchronization between the second ONU and the OLT. The OLT in an embodiment of the present invention does not need to obtain clock signals from an upper network and the clock information does not need to be transmitted in a multi-level mode over a packet network; therefore, the precision of ToD can be greatly increased.

Abstract: Distributed CMTS device for a HFC CATV network serving multiple neighborhoods by multiple individual cables, in which the QAM modulators that provide data for the individual cables are divided between QAM modulators located at the cable plant, and remote QAM modulators ideally located at the fiber nodes. A basic set of CATV QAM data waveforms may be transmitted to the nodes using a first fiber, and a second set of IP/on-demand data may be transmitted to the nodes using an alternate fiber or alternate fiber frequency, and optionally other protocols such as Ethernet protocols. The nodes will extract the data specific to each neighborhood and inject this data into unused QAM channels, thus achieving improved data transmission rates through finer granularity. A computerized “virtual shelf” control system for this system is also disclosed. The system has high backward compatibility, and can be configured to mimic a conventional cable plant CMTS.

Abstract: The present disclosure is directed to a passive optical avionics network system and method. A avionics network system may comprise: (a) a passive optical network, the passive optical network comprising an optical repeater; and (b) an avionics module operably coupled to the passive optical network. An integrated modular avionics (IMA) system may comprise: (a) a line-replaceable unit (LRU), the LRU comprising: (i) a processing unit; and (ii) an optical line terminal (OLT); (b) an optical repeater; (c) at least one optical network unit (ONU); and an avionics module operably coupled to the at least one ONU. A method for avionics network communication may comprise: (a) receiving optical avionics data signals; (b) monitoring the optical avionics data signals for compliance with a communications protocol; and (c) regulating transmission of the optical avionics data signals according to compliance with the communications protocol.

Abstract: A headend communications device communicates via a network to downstream network elements, such as cable modems coupled behind optical network units, and allocates and grants timeslots for upstream transmissions from the network elements. The headend communications device has a scheduler for managing and controlling timeslot allocations in a manner avoiding interference such as optical beat interference or FM carrier collisions. The scheduler identifies two or more cable modems or like customer network elements served by the headend communications device that will cause at least a pre-determined intolerable level of interference when allocated overlapping timeslots for upstream transmissions and prevents these two or more cable modems or network elements from being allocated and granted overlapping timeslots.

Abstract: A multi-core processor system including a main processor, an internal EPON bus, and a plurality of secondary core processors. The main processor includes a processing unit; an offload engine operatively connected to the processing unit for routing data to and from the processing unit; a plurality of main processor optical network units (ONU's) operatively connected to the offload engine; and, a dual optical line terminal (OLT) operatively connected to the offload engine. The internal EPON bus is operatively connected to the OLT. The plurality of secondary core processors are located physically separate from the main processor, each secondary core processor having a respective secondary core processor ONU being operatively connected to the main processor via the internal EPON bus.

Abstract: In one embodiment, a first module of a server system modulates a common-source optical signal to generate a modulated optical data signal, transmits the modulated optical data signal to a second module of the server system via an optical link, and the second module demodulates the optical data signal using a coherent detection technique using the common-source optical signal.

Abstract: An optical media converter system is divided into an outdoor installed optical media converter and an indoor installed unit, which are connected to each other through an electrical Ethernet cable. The indoor installed unit includes two electrical Ethernet terminations and a power source section for supplying an electrical power from indoor to outdoor. The outdoor installed optical media converter includes an optical-electric converter, optical Ethernet termination, electrical Ethernet termination, and a power source section for generating a power source by an electrical power supplied from the indoor. With the above configuration, there can be provided an optical media converter system in which the need to draw the fiber-optic cable into a home can be eliminated, cost involved in a wiring work can be reduced, and a circuit design thereof is advantageous in cost reduction.

Abstract: A method for reducing energy consumption of a passive optical network includes optical network units of the network which infer their downstream queue status rather than being explicitly notified by an optical line terminal of the network. Based on the inferred queue status, the optical network units make their own sleep mode decisions without assistance from optical line terminal. Both downstream traffic inference and sleep decision making at the optical network units are based on common information possessed by optical line terminal and optical network units. Accordingly, the optical line terminal can accurately infer the status of each optical network unit if the sleep control scheme implemented at an optical network unit is known by the optical line terminal.

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: A system, and methods for detecting collisions on multipoint shared optical media, comprising an optical receiver, clock phase detector, clock recovery circuit, and a Passive Optical Network (PON) that transmits optical signals wherein the PON, the clock recovery circuit, and the clock phase detector are communicably coupled to the optical receiver, detecting of the collision is determined by a distortion of transition times of the optical signals at the optical receiver.

Abstract: Techniques for updating configuration of an Optical Network Unit (ONU) in an Ethernet Passive Optical Network (EPON) include receiving a notification that an updated configuration file is available for the ONU, obtaining the updated configuration file, performing a first validation of the updated configuration file for structural errors, determining changes between a current configuration of the ONU and the updated configuration file to identify ONU resources to implement to the changes, performing a second validation about whether the ONU resources to implement the changes are available or not at the ONU and applying the changes to the ONU when it is determined that the ONU resources to implement the changes are available at the ONU.

Abstract: An apparatus comprising a data framer configured to frame an external protocol extension message for transmission, the external protocol extension message comprising a header that indicates an external protocol extension and at least one type-length-value (TLV) comprising a type field, a length field, and a value field, wherein a format of the TLV is specified by a specific organization, and wherein the value field comprises information related to protocol functions external to the network. Also included is an apparatus comprising at least one component configured to implement a method comprising compiling an external protocol extension message comprising a plurality of TLVs and a header that indicates an external protocol extension, and transmitting the external protocol message.

Abstract: A method for registration of multiple entities belonging to a specific optical network unit (ONU). In one embodiment, the multiple entity registration method comprises checking by an optical line terminal (OLT) if a registration request message received from the specific ONU belongs to a certain grant, and based on the check result, registering an entity as either a first or as an additional entity of the specific ONU. In another embodiment, the method comprises checking by an OLT of a reserved value of a flags field inside a registration request message, and based on the check result, registering an entity as either a first or as an additional entity of the specific ONU. The knowledge by an OLT that multiple entities belong to a specific ONU is used for grant optimization and packet data flow optimization.

Abstract: A system for transporting a plurality of digital signals includes a head-end unit for routing each digital signal to a particular modem, according to address information in the signal. At its respective modem, each digital signal is mixed for further transmission on a unique, modem-specific, radio frequency (fn) that is predisposed for a sub-octave transmission. A first converter then “stacks” a plurality of the different digital signals onto a common wavelength (?) for transmission as an optical signal over an optical fiber. At the receive end of the optical fiber, a second converter “de-stacks” the plurality of digital signals, and segregates them according to their respective unique radio frequency (fn). A distribution unit then directs each unique radio frequency signal to an addressed node for further transmission over a secondary network.

Abstract: A signal processing method, device, and system in a passive optical network are provided. The signal processing method in the passive optical network includes: performing baseband encoding processing on a received service signal; modulating the service signal after baseband encoding processing onto allocated Orthogonal Frequency Division Multiple Access subcarriers through an Orthogonal Frequency Division Multiplexing modulation manner; performing digital/analog conversion on the modulated OFDMA subcarriers to obtain an electric domain Orthogonal Frequency Division Multiple Access signal; modulating the electric domain Orthogonal Frequency Division Multiple Access signal to an uplink optical signal to obtain an optical domain Orthogonal Frequency Division Multiple Access signal; and transmitting the optical domain Orthogonal Frequency Division Multiple Access signal.

Abstract: A communication network access device is adapted for duplex communication and provides transmit and receive signal paths. A controllable socket is coupled to the transmit and receive signal paths and linked to a control interface for activating/deactivating the control interface. A pluggable module is coupled to the transmit and receive signal paths via the controllable socket in an activated status and to a transmission path carrying uni-directional signals. The module includes a first optical device and a splitter in the transmission path and is coupled to a second optical device via the splitter. The second optical device responds to a portion of uni-directional signals provided by the splitter for placing the communication access device in a link up condition for uni-directional signals provided by the first optical device to the transmission path serving an optical local area network.

Abstract: A method for sending uplink burst data in a passive optical network (PON) system includes: sending a synchronization pattern of the uplink burst data, the synchronization pattern being of a length, which is an integer multiple of 66 bits, and being formed by connection of 66-bit unit gene blocks; sending a burst delimiter (BD) of the uplink burst data; sending a forward error correction (FEC)-protected data in the uplink burst data; and sending an end of burst (EOB) delimiter of the uplink burst data. The technical solutions in the embodiments allow the use of a less complex equalizer at the reception end of a high-speed PON system.

Abstract: The present invention relates to the field of signal transmission using orthogonal optical frequency division multiplexing transceivers and to the use of the same set of wavelengths for the downlink and uplink signal transmission.

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: The present invention relates to the Passive Optical Network (PON) technology, and a method for sending an upstream transfer frame in a PON is provided, so as to improve flexibility of a system and satisfy a requirement that an error probability is reduced as low as possible. The method includes: after success of link, sending a preamble according to an allocated time slot, sending a burst synchronization delimiter, and then sending successively a burst header, a Gigabit-Capable Passive Optical Network (GPON) Transmission Convergence (GTC) frame header, and GTC frame data.

Abstract: An output control unit outputs data of bit rate A to a first header-attaching unit and data of bit rate B to a second header-attaching unit. An instructing unit instructs the first or the second header-attaching unit to attach a header of bit rate being the least bit rate to the data of bit rate A or B. The first header-attaching unit creates a header of bit rate A, including an ID of a destination ONU of the data of bit rate A and information concerning the data length, and attaches the header of bit rate A to the data of bit rate A. The second header-attaching unit creates a header of bit rate A, including an ID of the destination ONU of the data of bit rate B and information concerning the data length, and attaches the header of bit rate A to the data of bit rate B.

Abstract: In a WDM-PON system wherein a plurality of ONUs transfer signals by sharing wavelengths, one wavelength dedicated to a ranging procedure is set, and the ranging is performed with only the dedicated wavelength, so as to measure reciprocating delay times. At the other wavelengths, transmission signals from a plurality of ONUs are transferred in time division multiplexing based on the obtained reciprocating delay times. An OLT includes a burst receiver circuit for only the wavelength dedicated to the ranging, and subsequently to the ranging, the OLT adjusts transmission amplitudes and transmission phases for the ONUs, so as to equalize received amplitudes and received phases in the OLT. For this purpose, the OLT includes means for measuring the amplitudes and phases of received signals, as the burst receiver circuit, and it includes a table for managing the received amplitudes and received phases of the respective ONUs.

Abstract: A system, method, and computer readable medium for increasing an upstream optical coding gain in a passive optical network (PON). In an exemplary embodiment of the invention, the system may include a memory structured to store Optical Network Terminator (ONT) burst timing values, and provide a previous burst timing value of the burst timing values to a translator. Further, an upstream burst grant timing scheduler may provide a scheduled timing value to the translator, wherein the translator may be structured to translate the previous burst timing value to a new expected timing value per an ONT upstream burst in association with the scheduled timing value. Also, a delimiter match and search block may be structured to use the new expected timing value to check a bit stream for a delimiter pattern match. An alarm counter may be provided in the system that is structured to provide an alarm when the delimiter pattern match is not found.

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: 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 method and device for supporting optical transmission network service dispatch in an optical synchronization network, said device comprises service cards (401, 407), backplane interface (404) and a plurality of dispatch units (405, 406), wherein, the service cards (401, 407) process the service signals and distribute them to the backplane structure frame according to the bandwith of the service signals, and connect with the corresponding dispatch units (405, 406) through the backplane structure frame, and then the dispatch units (405, 406) execute the service dispatch. Said dispatch units (405, 406) can work independently from each other, and the dispatch units can be added linearly according to the bandwidth of the signal. The present invention can compatibly implement the uniform dispatch of the ODU and SDH service on the basis of the existing optical synchronization device without changing the backplane frame structure or increasing the backplane speed.

Abstract: A method for channel protection switching of an optical network device, an Optical Transport Network (OTN) device, and a Passive Optical Network (PON) device is provided. The method includes detecting, by the PON device, whether an OTN alarm indication signal is received after discovering a fault. If the OTN alarm indication signal is received, the alarm generated by the PON device is suppressed so that the PON device does not perform channel protection switching. The PON device detects whether an OTN alarm indication signal is received, and suppresses the alarm generated by the PON device so that the PON does not generate futile alarms or lead to futile switching when the OTN fails but the PON works normally.

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: An apparatus comprising a data framer configured to frame an external protocol extension message for transmission, the external protocol extension message comprising a header that indicates an external protocol extension and at least one type-length-value (TLV) comprising a type field, a length field, and a value field, wherein a format of the TLV is specified by a specific organization, and wherein the value field comprises information related to protocol functions external to the network. Also included is an apparatus comprising at least one component configured to implement a method comprising compiling an external protocol extension message comprising a plurality of TLVs and a header that indicates an external protocol extension, and transmitting the external protocol message.

Abstract: The present invention relates to a cable network using the frequency of a giga band. The optical signal transmission apparatus includes an optical transmission/reception unit converting received RF signals into RF optical signals and transmitting the RF optical signals, an optical line terminal converting received digital signals into digital optical signals and transmitting the digital optical signals, and a multiplexer receiving the optical signals from the optical transmission/reception unit and the optical line terminal and multiplexing the received optical signals.

Abstract: A communication unit inhibits delay and jitter during network communication, improving the communication quality. For this purpose, the communication unit includes: a first terminator that terminates a communication channel in the first optical communication scheme established between the communication unit and another communication unit; a second terminator that terminates a signal in the second optical communication scheme; and a path setting switch that switches between a first signal path setting and a second signal path setting.

Abstract: A signal transmission system for a peer-to-peer optical network. The system includes an optical line terminal, an optical distribution node, and a plurality of optical network units. The optical network unit and the optical distribution node are connected in a tree distribution having an ordered relation. The optical line terminal transmits optic signals via the optical distribution node to a first ordered optical network unit, to allow the first ordered optical network unit to process the optic signals and to generate combined optic signals, which are transmitted to a next ordered optical network unit via the optical distribution node. The above steps are iterated, until a last ordered optical network unit transmits combined optic signals to the optical line terminal via the optical distribution node.

Abstract: A Cable Television optical fiber communication system is disclosed, comprises a provider end, plural optical signal transmission devices and plural user ends, each optical signal transmission device is provided between the provider end and the user ends and has an light splitting element, a RF receive module, and a RF return module. The light splitting element is connected to the provider end via an optical transmission wire and is served to bi-directionally transfer a laser beam having a signal between the provider end and the user ends. The RF receive module is served to transfer a first signal of the provider end to the user ends. The RF return module emits a laser beam having a second signal to the provider end only when an analog return signal is emitted from the user end.

Abstract: An apparatus including a data framer and an optical transmitter. The data framer is used to frame a data stream into a plurality of frames, each of the frames includes a plurality of fields sized to align the frames with a word boundary greater than or equal to four bytes long. The optical transmitter is coupled to the data framer and is used to transmit the frames. Included is an apparatus with at least one component for implementing a method for encapsulating a data stream with at least one Gigabit Passive Optical Network (GPON) Encapsulation Method (GEM) payload aligned with a word boundary of at least four bytes long, encapsulating the GEM payload with a GPON Transmission Convergence (GTC) frame aligned with the word boundary, and transmitting the GTC frame.

Abstract: A modular, scalable, extensible, In-Flight Entertainment (IFE) data communication system is described. In one embodiment, the system comprises a hub providing connection between one or more server/switch line replaceable unit including at least one server and a plurality of passenger video display units. A server, such as, for example, an audio server, a video server, an audio/video server, a game server, an application server, a file server, etc., provides data (e.g., entertainment programming, internet file data, etc.) to the video display unit. In one embodiment, the connection between the plurality of server/switch line replacement units, the hub and the plurality of video display units is provided by passive fiber optic links.

Abstract: A manner of providing an energy-efficient two-stage PON using a multistage-PON repeater to forward data traffic and other communications between the first stage and the second stage. The multistage-PON repeater receives BI-PON transmission frames from and OLT and decimates them, forwarding data intended for end devices of the second stage. The multistage-PON repeater rate adapts the transmissions so that faster speeds may be associated with PON first stage communications and slower speeds are associated with PON second stage communications. Many though not all of the multistage-PON components are configured to operate at the slower clock speed, conserving energy. Upstream transmissions from the end devices of the second stage are buffered in the multistage-PON repeater and forwarded to the OLT according to an allocation schedule received from the OLT in a BI-PON frame.

Abstract: A protocol configuration method for use by a substation to be coupled to a main station in an optical access network is described.

Abstract: A radio-over-fiber (RoF) hybrid wired/wireless transponder is disclosed that is configured to provide both wireless and wired communication between a hybrid head-end and one or more client devices. The hybrid transponder includes optical-to-electrical (O/E) and electrical-to-optical (E/O) conversion capability and is configured to frequency multiplex/demultiplex electrical “wired” signals and electrical “wireless” signals. The electrical wireless signals are wirelessly communicated to the client device(s) via a multiple-input/multiple-output (MIMO) antenna system within a cellular coverage area. The electrical wired signals are communicated to the client device(s) via a wireline cable that plugs into a wireline cable port on the transponder. The hybrid RoF system includes a hybrid head-end capable of transmitting and receiving wired and wireless optical signals, and an optical fiber cable that is optically coupled to the hybrid head-end and to at least one hybrid transponder.

Abstract: A system, a method and a related device for signal transmission are provided in order to improve utilization efficiency of the fiber.

Abstract: In an optical access system, the OLT includes a CP inserting unit that inserts a CP into a downlink signal; a CP removing unit that removes a CP from an uplink signal received from the ONU; and an FFT unit, an EQ unit, and an inverse FFT unit that perform equalization on the uplink CP-removed signal according to a frequency domain equalization scheme based on an inverse characteristic of the characteristic of a transmission line leading to the ONU. The ONU includes a CP inserting unit; a CP removing unit; and an FFT unit, an EQ unit, and an inverse FFT unit that perform equalization on the downlink CP-removed signal according to the frequency domain equalization scheme based on an inverse characteristic of the prestored characteristic of the a transmission line leading to the OLT.

Abstract: Methods and systems for providing flexible node segmentation are provided. For example, the system can be configured to delay node segmentation in the headend/hub even though the fiber node has been segmented. When a desire for node segmentation in the headend/hub arises, the receiver can be efficiently upgraded through the use of a control signal to provide a receiver output port to each sub-service area.

Abstract: A method, apparatus and system for aligning frames in which an Optical Network Unit (ONU) receives a frame comprising frame delimitation information and synchronization-related information; performs a first verification based on a comparison of the frame delimitation information and a fixed pattern; performs a second verification based on a comparison of the synchronization-related information and a value associated with synchronization-related information in a previously received frame; proceeds to a synchronization state if both the first verification and the second verification are successful; and returns to a hunt state if either the first verification or the second verification fails.

Abstract: The invention facilitates optical signals generated from customer premise equipment (CPE) at the edges of the metro domain networks. The CPEs are connected to extension terminals that transform the optical signal originating at the CPE into a suitable format for long haul transmission. The optical signal then propagates to a primary terminal where the signal is multiplexed with other optical signals from other extension terminals. The multiplexed signals are then transmitted over LH or ULH network to a second primary terminal where the signal is then demultiplexed from other optical signals and transmited to the proper extension terminal. At the extension terminal, the demultiplexed optical signal is transformed from its LH format back into a format suitable for inter-connection to a CPE. Using this architecture, the signal under goes optical-to-electrical conversion only at the extension terminals or end points. These end points can be located in lessee's facility.