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: In a GPON system conforming to ITU-T Recommendations G.984.3, an optical line terminal is provided which has an active bandwidth allocation function that preferentially puts small bandwidth signals in a particular segment of a frame, e.g., at a head of the frame, to prevent fragmentations that may occur particularly when allocating small bandwidths of about 100 kbits/s.

Abstract: The present invention relates to a wavelength-division multiplexed passive optical network (WDM-PON) for reducing degradation in noise characteristic of a wavelength-locked Fabry-Perot Laser Diode (F-P LD).

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: Techniques, apparatus and systems for optical communications, including fiber ring networks with protection switching to maintain optical communications when an optical failure occurs and to automatically revert to normal operation when the optical failure is corrected, fiber ring networks that provide a circulating optical probe signal at an optical probe wavelength within the gain spectral range of optical amplifiers used in a fiber ring network to detect an optical failure, and fiber ring networks that support broadcast-and-select optical WDM signals carrying communication traffic to the optical ring nodes without regeneration at each optical ring node and one or more overlaid in-band node-to-node optical signals carrying communication traffic with regeneration at each node.

Abstract: An optical source for wavelength division multiplexed optical network according to the present invention comprises a broadband light source (BLS); an arrayed waveguide grating (AWG) for spectrum-dividing incoherent light outputted from the BLS; a circulator being connected between the BLS and the AWG; and a plurality of un-polarized light sources (UPLS) being respectively connected to the AWG, wherein the incoherent light which is spectrum-divided by the AWG is injected into the plurality of UPLS and thus the plurality of UPLS is wavelength-locked thereto. In case of using an optical source for wavelength division multiplexed optical network and a wavelength division multiplexed-passive optical network having the same according to the present invention. It is especially possible to lower dramatically the power of incoherent light being injected into a wavelength-locked Fabry-Perot laser diode, while to enable a high transmission speed of 1.

Abstract: A system is disclosed for an improved ROSA that has increased sensitivity for permitting greater numbers of ONTs to be connected to an optical network per defined transmission line distances. The ROSA configuration includes a digital optical module with improved performance characteristics. This digital optical module has replaced a conventional photodiode with a PIN detector that is coupled with the TIA. The resulting digital optical module containing this PIN/TIA configuration when incorporated in a ROSA provides a single ROSA solution that will meet or exceed the ITU/IEEE FTTx standards for short and long distances under substantially all operating conditions.

Abstract: An improved method and apparatus is provided for transmitting a WDM optical signal. The method begins by modulating optical channels that are each located at a different wavelength from one another with (1) a respective one of a plurality of information-bearing electrical signals that all embody the same broadcast information; (2) a respective one of a plurality of RF signals having a common functional broadcast waveform, at least one of the RF signals being out of phase with respect to remaining ones of the plurality of RF signal and (3) at least one of the RF signals being phase adjusted with respect to its original phase. Each of the modulated optical channels is multiplexed to form a WDM optical signal. The WDM optical signal, while maintaining the pre-assigned phase relationships between the modulation signals of the optical channels, is forwarded onto an optical transmission path.

Abstract: In a Wavelength Division Multiplexed Passive Optical Network (WDM-PON) including, a system for overlaying an analog broadcast signal. An Optical Line Terminal of the WDM-PON includes a broadband light source for generating uplink seed light for each uplink channel of the WDM-PON, and a modulator for modulating the analog broadcast signal onto the uplink seed light. An Optical Network Terminal of the WDM-PON receives the uplink seed light from the Optical Line Terminal, and includes an optical divider for dividing the received seed light into a first signal and a second signal; a light source for generating an uplink data signals using the first signal as seed light; and an RF receiver for detecting the analog broadcast signal modulated on the second signal.

Abstract: An optical communication system includes a plurality of wavelength selective switches arranged on an optical network; and an optical network management apparatus configured to manage and control the optical network. In response to a path establishing request, the optical network management apparatus determines power consumption of each path that satisfies the path establishing request in the optical network based upon a wavelength being used at a connection port of each of the wavelength selective switches, selects a route based upon the determined power consumption of each of the path, and sets the selected route in the optical network.

Abstract: A passive optical network is upgraded by a subsystem PON2 for additional high speed communication. The additional subsystem PON2 enables independent high speed communication between a new type of optical network terminations with second downstream time division multiplex signals and second upstream multiplex burst signals via additional upstream and downstream channels.

Abstract: There is provided a wavelength division multiplexing transmission system and apparatuses used therein, in which a remote apparatus to be newly added to a station apparatus autonomously sets a wavelength to be used in the remote apparatus, thereby avoiding the need for presetting a wavelength to be used in the remote apparatus. The remote apparatus includes wavelength determining means that determines an available wavelength on the basis of an optical signal received from the station apparatus. The wavelength determining means may determine the wavelength of an unreceived optical signal as the available wavelength or may determine the wavelength of a received optical signal as the available wavelength, and may set that wavelength as a transmission and reception wavelength to be used in the remote apparatus.

Abstract: Provided is a bidirectional wavelength division multiplexed passive optical network (WDM-PON) which includes a central office (CO) that transmits and receives multiplexed optical signals, a remote node (RN) that communicates with the CO, receives a multiplexed optical signal to demultiplex, and receives a demultiplexed optical signal to multiplex, an optical network unit (ONU) that transmits and receives demultiplexed optical signals to and from the RN, operational and protective backbone optical fibers that connect the CO to the RN, and operational and protective distribution optical fibers that connect the RN to the ONU.

Abstract: An apparatus comprising a plurality of optical line terminals (OLTs) corresponding to different providers that share an optical distribution network (ODN), a plurality of optical network units (ONUs) coupled to the OLTs via the same ODN and configured to communicate with the different OLTs using different corresponding pairs of upstream and downstream channels, wherein the upstream and downstream channels are interleaved across a plurality of wavelength bands and comprise a sequence of alternating and contiguous upstream and downstream channels, are aligned with a plurality of wavelength division multiplexing (WDM) channels, and satisfy a plurality of design requirements for the OLTs and ONUs.

Abstract: A network system and method include a wireless base station integrated at a central office of a service provider. The wireless base station is configured to provide portable and fixed services to customers. A passive optical network is coupled to the wireless base station at the central office to provide a link to extend an antenna for wireless operations of the wireless base station to a remote site such that a wireless signal from the wireless base station is transmitted in parallel with a passive fiber network signal through the link.

Abstract: Techniques for partitioning and/or combining at least a portion of an optical network tree including one or more array waveguide gratings (“AWGs”) and fibers in wavelength division multiplexing (“WDM”) passive optical networks (“PON”) with cascaded AWGs are disclosed. Example methods include deriving the optimal positions for the AWGs to minimize fiber cost and then determining the arrangement of cascaded AWGs to minimize the total cost of AWGs and fibers. Determining the arrangement of cascaded AWGs may include recursive partitioning followed by recursive combination. An example recursive partition-combination based algorithm for optimizing a tradeoff between the AWG cost and the fiber cost is disclosed.

Abstract: A general object of the present invention is to provide an optical communication system in which an optical transmission power of an optical communication apparatus is controlled to be a required minimum power that apparatuses of all subscribers in the optical communication system meet a prescribed error rate. An optical line terminating apparatus (OLT) transmits data to multiple optical network apparatuses (ONUs) at an optical intensity calculated based on information acquired from the multiple ONUs, which is related to optical intensities of signals that the multiple ONUs receive from the OLT, the optical intensity being calculated so that a minimum optical intensity of the optical intensities of the signals is greater than a predetermined value.

Abstract: According to one embodiment of the present invention, a wavelength-shifted dynamic intelligent bidirectional access optical system utilizes key optical elements such as: a quantum dot enabled semiconductor optical amplifier, a phase modulator and an intensity modulator to provide upstream optical signals. These key optical elements reduce the Rayleigh backscattering effect on the transmission of optical signals. to enable a longer-reach access network topology between a subscriber unit and a super node (e.g., many local nodes collapsed into one super node). Such a longer-reach access network topology eliminates operational and capital costs related routers and switches. Furthermore, a wavelength to a subscriber unit may be protected and dynamically varied for on-Demand bandwidth, information and services and also a subscriber's unit may be configured with any array of connectivity options.

Abstract: A system and method for a transparent WDM metro ring architecture in which optics enables simultaneous provisioning of dedicated wavelengths for high-end user terminals, while low-end user terminals share wavelengths on “virtual rings”. All wavelengths are sourced by the network and remotely modulated at customer “End Stations” by low cost semiconductor optical amplifiers, which also serve as transmission amplifiers. The transparent WDM metro ring architecture permits the communication of information and comprises a fiber optical feeder ring, at least one fiber optical distribution ring, a network node (NN), at least one access node (AN) said network node and said at least one access node connected via said fiber optical feeder ring and at least one end station (ES) connected via said fiber optical distribution ring to said at least one access node, wherein said user is attached to said at least one end station.

Abstract: An apparatus comprising a plurality of data framers, a time division multiplexer coupled to the data framers, and an optical transmitter coupled to the time division multiplexer. Also disclosed is an apparatus comprising an optical receiver, a time division demultiplexer coupled to the optical receiver, and a data framer coupled to the time division demultiplexer. Also disclosed is an apparatus comprising at least one component configured to implement a method comprising combining a first plurality of data frames corresponding to a first plurality of channels into a first plurality of combined data frames using time division multiplexing and transmitting the first combined data frames over a single optical channel.

Abstract: A time division multiplex (TDM)/wavelength division multiple access (WDMA) passive optical network (PON) device includes a base station terminal, a wavelength splitter, and a subscriber terminal optical transceiver. The base station terminal includes a transmitter, an optical circulator transmitting the optical signals output from the transmitter to an optical distribution network, and a receiver demultiplexing wavelength division multiplexed upstream signals from the optical distribution network through the optical circulator. The wavelength splitter splits the downstream signals from the base station terminal to subscriber ports corresponding to wavelengths and multiplexes the optical signals received from each of the subscriber ports to the base station terminal. The subscriber terminal optical transceiver receives the downstream signals from the wavelength splitter and reuses the received downstream signals as optical sources for upstream signals.

Abstract: Optical remote node (NR) device which is situated at a remote point in a fiber-optic metropolitan or access network, carries out the functions of connecting, and transmitting information between, various sections of the network in a passive manner without a power supply using various optical components which extract the necessary optical signals and optical pumping power from the network to which the remote node is connected, and introduces the optical signals from the sections which it connects into said network, and support equipment which is situated at a point in the network with a power supply, uses the network to provide the pumping power required by the remote nodes and has the electronics needed to carry out functions of monitoring the operation of the remote nodes and regulating their activity.

Abstract: A distributed resources sharing method using weighting factors of sub-domains in an optical network includes connecting working paths to an optical network according to a request of a subscriber, and calculating weighting factors for measurement of concentration of the sub-domains including the working paths by using information on connected working paths. The method also includes setting up the backup paths by using the weighting factors, and allocating resources in response to connection request at the time of setting up the backup path and sharing the allocated resources. With this method, it is possible to prevent a waste of idle resources caused from concentration of allocated resources. In addition, since the information of the idle resources in the network can be sensed at the time of selecting the backup paths by using a weight factor, the shared resources can be distributed, thereby maximizing efficiency of the resources.

Abstract: Provided is an apparatus for implementing an electro-optical cable distribution network in which a coaxial cable is replaced with an optical cable in order to provide a service integrating broadcast data and communication data by solving a frequency constraint problem in a cable television (CATV) network employing a conventional hybrid-fiber coaxial (HFC) network architecture. The apparatus includes an optical network unit (ONU) which converts a downstream signal received from a system operator (SO) into an optical signal and transmits the optical signal to an optical cable; and an optical cable modem which receives the optical downstream signal from the ONU and converts the received signal into an electrical signal. In addition, the ONU and the optical cable modem control signal quality of an optical path.

Abstract: A method, a computer readable medium, and a system for discovering an Optical Network Terminal (ONT) in a Dense Wave Division Multiplex (DWDM) hybrid Passive Optical Network (PON) Line Terminal (LT), comprises implementing, by an Optical Line Termination (OLT), a ranging procedure on at least one downstream link, wherein the OLT is communicably coupled to the ONT, discovering at least one new ONT, by the OLT, on the at least one downstream link based on the ranging procedure, discovering an unranged ONT, by the OLT, during the ranging procedure, and determining, by the OLT, that the unranged ONT resides on the at least one downstream link.

Abstract: In a PON system by WDM, IP broadcast can be received without oppressing a band used by a user for Internet communication. An OLT provides a first wavelength received in common by respective ONUs and plural second wavelengths by which the OLT and the respective ONUs perform communication individually. With respect to signals in the downstream direction, each of the OLTs includes a transmitter to transmit the first wavelength and plural transmitters to transmit the second wavelengths used for the individual communication with the respective ONUs. Each of the ONUs includes a receiver to receive the first wavelength and a receiver to receive the second wavelength used in the ONU itself. The OLT transmits data of the IP broadcast by the first wavelength and transmits individual data of each of the ONUs by the second wavelength corresponding to the ONU.

Abstract: A optical switch and switching system is provided for effecting a switchover from a first optical fiber to a second optical fiber includes a first, large scale switching component and a second, small scale switching component. The first, large scale switching component is configured to establish a cross connect between the second optical fiber and the second, small scale switching component. The second, small scale switching component may then be configured to select the cross connect following establishment of the cross connect, thereby ensuring rapid switchover from the first fiber to the second fiber, regardless of the speed of the first large scale switching component.

Abstract: An arrangement is provided for transporting information from a central information distribution center (CIDC) to locations where such information is intended. Upon receiving a request for narrowcast information to be delivered to a node associated with a head end, the CIDC selects the requested information, generates an optical signal encoded with the requested information using information channels dedicated to narrowcast information transport for the node, and sends the optical signal to the head end via an optical fiber. When the head end receives the optical signal, the narrowcast information transport channels dedicated to the node are translated into subcarriers acceptable to the node before the requested narrowcast information is forwarded to the node.

Abstract: When an XFP is plugged into an optical interface unit by live-line plugging, an external bias voltage higher than an internal bias voltage is kept applied to a CDR incorporated in the optical interface unit until the XFP starts up. This prevents exertion of a negative effect on the CDR.

Abstract: Methods and structures are disclosed demultiplexing optical signals transmitted over an optical fiber into a silicon substrate and to multiple detectors. The silicon substrate has two spaced-apart surfaces and a diffractive element disposed adjacent to one of the surfaces. Each of the optical signals corresponds to one of multiple wavelengths. The optical signals are directed into the silicon substrate along a path through the first surface to be incident on the diffractive element. The path is oriented generally normal with the first surface and/or with the diffractive element, which angularly separates the optical signals such that each of the wavelengths traverses through the substrate in a wavelength dependent direction to the first surface. Each optical signal is steered from the first surface towards the second surface to be incident on different optical elements that direct them generally normal to the first surface to be incident on one of the detectors.

Abstract: A three-arm-Mach-Zehnder interferometer for splitting/combining a first and a second wavelength band, wherein the optical device includes: a first and second optical splitting/combining element; a differential optical delay device comprising a first, a second and a third optical path; each of the first and second optical splitting/combining elements, is of the (25-50-25%)?x(0-0-100%)?y type, wherein ?x is a wavelength with the first optical band and ?y is a wavelength with the second optical band, and the first, second and third optical paths of the differential optical delay device are configured to introduce, at a wavelength ?z within the first optical band, a phase delay ?? of 2?m.

Abstract: The present invention provides a PON system including a plurality of PONs (passive optical network), a plurality of house devices set in an end user's house, and a station side device including a plurality of PON interface sections connected to the house devices via the plurality of PONs, and a concentrating/distributing section for accommodating the plurality of PONs and concentrating and distributing signals via the plurality of PON interface sections; wherein the station side device has N (N is a positive integer) optical switch modules, each of which is connected to a PON interface section for current use among the plurality of PONs; and realizes 1:N redundant of the PONs by cascading the N optical switch modules.

Abstract: An object of the present invention is to continue to send and receive to/from a host when a failure has occurred in a storage device interface. A storage system includes a host and a storage device connected to the host via a communication line, wherein the storage device comprises a communication controller performing data communication with the host by using optical modules, and wherein the communication controller is provided with first optical modules performing data communication with the host; a second optical module performing data communication with the host, in place of a first optical module; and a controller switching, when a failure has occurred in any of the first optical modules, the first optical module in which the failure has occurred to the second optical module.

Abstract: According to the present invention, a star-type wavelength multiplexed communication network using optical TX/RX devices capable of assigning the wavelengths can be provided without using the monitoring light. In an embodiment of the present invention, an optical TX/RX device for transmitting and receiving a wavelength-multiplexed signal light comprises an optical receiver capable of varying the RX wavelength and an optical transmitter capable of varying the TX wavelength. The optical TX/RX device detects RX wavelengths not in use via the optical receiver, and assigns the RX wavelength of the optical receiver to one of the RX wavelengths not-in-use, and assigns the TX wavelength of the optical transmitter to a TX wavelength corresponding to the RX wavelength according to a correspondence table of TX and RX wavelengths in the memory. Then, the optical TX/RX device transmits a signal light on this TX wavelength, and detects the response on the RX wavelength.

Abstract: While continuously providing a service in an existing optical communication system, a service at another communication speed is realized at low cost. For this reason, a station-side optical network terminal apparatus is configured so that to one light-emitting unit connected are a first processing unit that performs a process to output an optical signal at one communication speed by the light-emitting unit and a second processing unit that performs a process to output an optical signal at another communication speed by the light-emitting unit.

Abstract: In one embodiment, a passive optical network is provided that includes: an optical line terminal (OLT) configured to transmit a plurality of downstream signals into a corresponding plurality of passive optical networks and to receive a corresponding plurality of upstream signals from the plurality of passive optical networks, wherein each downstream signal is separated in wavelength from the remaining wavelength signals, and wherein each upstream signal is separated in wavelength from the remaining upstream signal; a Mux/Demux configured to multiplex the downstream signals from the OLT into a optical fiber and to demultiplex upstream signals from the optical fibers to the OLT; and a splitter configured to split the downstream signals from the OLT to a plurality of optical network units such that each optical network unit receives the plurality of downstream signals.

Abstract: A WDM optical system includes first and second WDM's including an optical link therebetween. Each WDM includes circuitry for linking multiplexer and demultiplexer circuitry to a plurality of modular elements. The modular elements include a first set of modules for converting between native protocol media signals and common format signals. A second set of modules converts between the common format signals and optical signals at separate wavelengths for communication with the multiplexers and demultiplexers. A dual path transmit and receive optical link is provided between near and far end WDM's.

Abstract: An optical data transmission system having a hub, an optical router, and a plurality of optically pumped sources at a curb location, and a plurality of optical network units (ONUs). The ONUs generate and transmit respective data modulated pumping light to the curb location where it is received by the optically pumped sources, which convert it into the wavelength channels having predefined wavelength ranges assigned to respective ONUs. The optical router routes the wavelength channels for transmission to the hub.

Abstract: An optical network is provided including a first optical network section operatively coupled to a carrier facility configured to transmit traffic onto channels in the first optical network section. A second optical network section may be operatively coupled to the first optical network section at a first node. Additionally, the second optical network section may be operatively coupled to a customer location at a second node. The first and second nodes may include tunable filters for passing traffic via at least one channel from the first optical network section to the second optical network section.

Abstract: A method and apparatus is provided for tracking a thermally floating wavelength signal channel grid generated at an optical transmitter (Tx) in an optical transmission system or optical network where the wavelengths of the individual Tx signal channels may move in wavelength due to, for example, changes in ambient temperature at the optical transmitter but the channel spacing between Tx signal channels along the thermally floating Tx wavelength grid remains constant.

Abstract: A data center for executing a data processing application includes processing units, sub-units or servers. Each of the processing units, sub-units or servers can execute a part or all of the data processing application. The processing units, sub-units or servers are electrical disjoint with respect to data communications, but can communicate with each other over free space optical links.

Abstract: A system includes an optical line terminal (OLT) that includes an OLT transmitter. The OLT transmitter includes one or more fixed wavelength optical sources that generate an optical signal at a first wavelength, and an optical waveguide that transmits the optical signal at the first wavelength in an optical network.

Abstract: Provided is an ONU that suppresses transmission of a useless multicast control message to a PON section and enables a communication bandwidth of the PON section to be effectively used. The ONU of the PON system has a multicast group management table that shows a correspondence between a multicast group identifier and an address of a user terminal participating in a multicast group. When the ONU receives a request message of participation in the multicast group from the user terminal, the ONU registers the correspondence between the multicast group identifier indicated by the received message and the user terminal address. A new received message is deleted without being sent to the OLT if another user terminal address is registered already, along with a correspondence with the same multicast group identifier, in the multicast group management table.

Abstract: A relaying method of an optical signal of a hybrid relaying apparatus in a gigabit passive optical element includes: selecting and receiving any one of a first serial electrical signal corresponding to a downlink wavelength division multiplexing-passive optical line terminal (WDM-PON OLT) optical signal and a second serial electrical signal corresponding to a downlink gigabit passive optical network optical line terminal (GPON OLT) optical signal; modulating the downlink serial electrical signal to a downlink GPON transmission convergence (GTC) frame; extracting control information for uplink transmission from the downlink GTC frame; converting the downlink GTC frame into the downlink serial electrical signal; and converting the converted serial electrical signal into an optical signal and transmitting the converted optical signal in a GPON OLT optical transceiver.

Abstract: A number of fiber optic interconnection systems and apparatuses, optical network nodes, and methods are disclosed. One fiber optic interconnection system embodiment includes a first interconnectivity component for receiving and sending one or more signals between at least a first optical network node and a second optical network node, a second interconnectivity component for receiving and sending one or more signals between at least the first optical network node and the second optical network node, a distribution component that encodes an information signal onto a number of optical signals having different wavelength ranges, and a directional component for directing the number of optical signals having different wavelength ranges through one of the first or second interconnectivity components.

Abstract: A method and system for provisioning a Resilient Packet Ring (“RPR”) over a Wavelength Division Multiplexing (“WDM”) network is disclosed. A plurality of stations send data packets to each other over a dual ring fiber optic link. The data packets travel over the dual ring fiber optic link at a unique wavelength to distinguish the different data packets. When one station of the plurality of stations detects a location of a failure in the WDM network, the station identifying the location of the failure either notifies all stations of the plurality of stations of the location of the failure or notifies only the stations of the plurality of stations abutting the location of the failure. If all stations of the plurality of stations are notified of the failure, all stations steer data packets sent towards the location of the failure away from the location of the failure.

Abstract: System and method for data synchronization in Passive Optical Networks. 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: A network interface apparatus comprises a bidirectional optical signal port, an optical diplexer connected to the bidirectional optical signal port, a first RF signal port (bidirectional), a second RF signal port, a first RF diplexer, and an RF splitter. The RF diplexer transmits a first received RF input signal from the first RF signal port to the optical diplexer to modulate an optical output signal transmitted by the optical diplexer to the optical signal port. The RF splitter receives from the optical diplexer an RF signal derived from an RF-modulated optical input signal received from the bidirectional optical signal port, transmits a first portion of the derived RF signal as a first RF output signal to the first RF signal port through the first RF diplexer, and transmits a second portion of the derived RF signal as a second RF output signal to the second RF signal port.

Abstract: An optical access communication apparatus and an optical access communication system for the coexistence of two wideband PON systems without using an expensive optical device or module. A low-speed PON and a high-speed PON have a same upstream wavelength, and an OLT receives optical signals by a same optical receiver in the two systems, converts the optical signals into electric signals, amplifies the electric signals, branches the amplified electric signals, and processes the branched signals by clock and data recovery sections of bit rates corresponding to the two PON systems, thereby achieving an optical communication apparatus and an optical communication system for constructing a simple and low-cost triple-play service system of excellent transmission quality.

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.