Abstract: A communication control method performing Discovery processing, which is a procedure at an OLT to detect an ONU newly connected, in a PON system, the method includes: a transmission-permission-signal transmitting step of transmitting, by the OLT, a transmission permission signal for discovery, which includes an individual number of an ONU that is permitted to respond and mask information for designating a match-detection target bit for the individual number; and a registration-request-signal transmitting step of comparing, by an ONU, which is not registered in the OLT, a match-detection target bit for the individual number designated in the mask information with an individual number of the ONU based on a received transmission permission signal, and when the target bit and the individual number match each other, transmitting a registration request signal to the OLT.

Abstract: Various embodiments of the present invention are directed to methods and systems for transmitting optical signals from a source to a plurality of receiving devices. In one method embodiment, an optical enablement signal is transmitted (401) from the source to the plurality of receiving devices. The target receiving device responds to receiving the optical enablement signal by preparing to receive one or more optical data signals. The source transmits the one or more optical data signals to the target receiving device. The remaining receiving devices do not receive the one or more optical data signals.

Abstract: An apparatus comprising a path computation element (PCE) configured to perform a path computation using signal compatibility constraints information for a network element (NE) in a wavelength switched optical network (WSON), wherein the signal constraints information are communicated at a Generalized Multi-Protocol Label Switching (GMPLS) control plane layer and comprise a plurality of signal attributes and a plurality of NE compatibility constraints. A network component comprising a transmitter unit configured to transmit signal compatibility constraints via GMPLS signaling, wherein the signal compatibility constraints define the signal compatibility constraints for a NE in a WSON. A method comprising receiving signal compatibility constraints for a NE in a WSON, performing a path calculation based on the signal compatibility constraints for the NE, and sending signal compatibility constraints associated with a computed path.

Abstract: A system and method for securing communications over a wave division multiplexing optical network between a plurality of users connected to the network. The system utilizes a primary optical source generator that is either tunable, or capable of generating a plurality of wavebands of different frequencies equal to the sum of wavebands serving individual users of the network to facilitate a key exchange between the individual users of the network using summed wavebands, each of which serving an individual user.

Abstract: According to one embodiment, a system for transmitting an optical signal comprises a traffic distribution circuit configured to distribute traffic to a plurality of wavelength division multiplexer (WDM) modules. The system further comprises a first WDM module and a second WDM module. The first and second WDM modules each comprise a plurality of tunable optical transmitters, with each transmitter associated with a different wavelength band of a plurality of wavelength bands. Each transmitter in the first and second WDM modules is also tuned to transmit optical signals in channels included within the associated wavelength band of the transmitter. The first and second WDM modules each comprise a multiplexer configured to combine the optical signals transmitted from the plurality of transmitters into optical signals. The system further comprises a cyclic multiplexer configured to combine the optical signals from the first and second WDM modules into an optical output signal.

Abstract: Due to demand for more network bandwidth, a need for multi-user optical network topologies has, and will continue to, increase. A method or corresponding apparatus in embodiments of the present invention provide for an availability determination tool for determining and displaying wavelength and subrate availabilities within a network. Benefits of embodiments of a tool include allowing a user to identify the availability and capacity of any wavelength on any network, via an interactive graphical user interface, such as by using three-dimensional representations. In one embodiment, the disclosed availability determination tool allows users to locate and view any combination of available wavelengths between nodes in an optical network topology, and generate graphical and tabular reports of the availability in order to maintain an efficient and organized method or apparatus for determining and controlling wavelengths in a network.

Abstract: An apparatus comprising a path computation element (PCE) coupled to a path computation client (PCC) and configured to perform a path computation using port wavelength restriction information for a network element (NE), wherein the port wavelength restriction information is encoded and received in a port wavelength restriction Type-Length-Value (TLV) that comprises a matrix identifier (ID), a restriction type, and the port wavelength restriction information. Also disclosed is a network component comprising at least one processor coupled to a memory and configured to receive a port wavelength restriction information TLV that corresponds to a NE, and obtain a restriction type and port wavelength restriction information based on the restriction type from the port wavelength restriction TLV, and use the port wavelength restriction information to calculate a path for the NE.

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: There is provided an optical transmission apparatus including: a plurality of wavelength selective switches including input ports, a transmission port, and monitor port used to output a light switched so that the light from the input port is monitored; a multiplexer to combine the lights output from the transmission ports of the plurality of wavelength selective switches; a monitor to monitor whether a same wavelength of the light output from the monitor port exists in wavelengths of the lights combined by the multiplexer; and a controller to control the wavelength selective switch so as to output, from the transmission port, the light switched to the monitor port in case that the same wavelength of the light output from the monitor port is absent in wavelengths of the lights combined by the multiplexer, based on a monitor result by the monitor.

Abstract: Optical safety functions are incorporated into protection switching modules which maintain redundant pathways to avoid interruptions in optical network connections. The optical safety functions which lower optical power levels upon interruptions of optical connections are effectively combined with protection switching procedures which are also triggered by interruptions in optical network connections. The interoperation of protection and safety processes keep optical power levels below hazardous levels at system points which might be accessible to human operators.

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: 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: An optical network and an optical signal modulation method thereof are provided. The optical network includes an optical fiber and a remote node (RN). The RN receives a continuous carrier wave from the optical fiber and modulates the continuous carrier wave to generate a first frequency offset carrier wave The frequency of the first frequency offset carrier wave is different from that of the continuous carrier wave. A first user device re-modulates and loads data to the first frequency offset carrier wave to generate a first upstream signal. The frequency of the first upstream signal is the same as that of the first frequency offset carrier wave. The RN inputs the first upstream signal into the optical fiber.

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: One embodiment provides a media access control (MAC) module facilitating operations of an Ethernet passive optical network (EPON). The MAC module includes a frame formatter configured to generate a MAC control frame. The generated MAC control frame includes at least one of: an organizationally unique identifier (OUI) field, an OUI-specific operation code (opcode) field, and a number of fields associated with the OUI-specific opcode. Transmission of the MAC control frame facilitates realization of an EPON function based on the fields associated with the OUI-specific opcode.

Abstract: An optical communication system includes a first optical communication apparatus configured to insert a wavelength control signal in a main signal to produce a modified main signal; convert the modified main signal into a first optical signal; and transmit the first optical signal, and a second optical communication apparatus configured to receive the first optical signal; extract the wavelength control signal from the received first optical signal; determine a wavelength of a second optical signal based on the extracted wavelength control signal; and transmit the second optical signal to the first optical communication apparatus.

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: 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: 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: In a method of allocating a bandwidth of a passive optical network, downward data are transmitted by varying a wavelength based on a wavelength division method and upward data are transmitted using a time division method. Thereby, by efficiently allocating a network bandwidth, data can be transmitted and by realizing statistical multiplexing, transmission efficiency can be improved.

Abstract: A method and a device convey data across a shared medium, wherein at least one resource is allocated for an end-to-end connection. Then the data is conveyed across the shared medium via the end-to-end connection. In this manner an efficient data transport throughout a network containing several domains or networks utilizing various technologies is accomplished.

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: 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: A tunable element of a tuning module is receptive to optical data channels of a multiplexed optical data signal, each optical data channel having a different respective wavelength. The tunable element is responsive to different stimuli such that multiple passbands of the tunable element are defined, each passband corresponding to a respective stimulus and including no more than one wavelength of the optical data channels. An optical detector communicates with the tunable element and is receptive to no more than one optical data channel from the tunable element at any given time, an output of the optical detector is an electrical data signal that corresponds to the optical data channel received by the optical detector from the tunable element. A controller communicates with the tunable element and tunes the tunable element from one optical data channel to the other by causing application of a corresponding stimulus to the tunable element.

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: An apparatus, comprising a first node configured to communicate with a second node to generate a wavelength assignment, wherein the first node is configured to send a wavelength availability information to the second node. Included is a network component comprising at least one processor configured to implement a method, comprising receiving a wavelength availability information, and updating the wavelength availability information using a local wavelength availability information. Also included is a method, comprising acquiring a local wavelength assignment information, calculating a local wavelength availability information, and transmitting the local wavelength availability information to a subsequent network element on a lightpath.

Abstract: Disclosed is an apparatus and method for medium access control (MAC) in an optical packet-switched network. The MAC apparatus may comprise a bandwidth allocation module and an MAC processor. The bandwidth allocation module determines a data transmission limit based on a probabilistic quota plus credit mechanism for each node of the network, dynamically informs all downstream nodes of unused quota and allows the downstream nodes to use remaining bandwidths of the upstream node. Through a control message carried by a control channel, the MAC processor determines uploading, downloading and data erasing for a plurality of data channels, and updates the corresponding contents in the control message.

Abstract: Provided is a channel assignment method in a wavelength-division-multiplexed transmission system. The channel assignment method includes obtaining information about signal modulation schemes from a plurality of optical transmitters, and assigning channels to the respective optical transmitters in consideration of the obtained information about the signal modulation schemes. Accordingly, in transmission of channels of different modulation formats, cross phase modulation is minimized, thereby reducing inter-channel interference.

Abstract: OFDM (Orthogonal Frequency Division Multiplexing) has been proposed for processing signals over WDM channels in an optical network. The number of OFDM sub-carrier channels utilized in transmitting optical signals from a transmitting node to a remote is adapted to the quality of transmission in a WDM channel. Responsive to control signals from the remote node, the number of used sub-carrier channels is set to optimize optical performance of the WDM channel.

Abstract: Methods and apparatus are described for DWDM transport of CATV and digital signals over optical fiber in low-dispersion spectral regions. A method includes transporting a plurality of optical carriers of different wavelengths over an optical link using wavelength division multiplexing, the optical link including a plurality of optical segments. The plurality of optical channel center wavelengths defined by the plurality of optical carriers are clustered proximate an average value of a zero-dispersion wavelength of the optical link, or near either a) a low wavelength edge or b) a high wavelength edge of a range of zero-dispersion wavelengths of the optical link and a plurality of optical channel center frequencies defined by the plurality of optical channel center wavelengths are non-uniformly spaced apart.

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

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: According to one embodiment, a system for transmitting an optical signal comprises a traffic distribution circuit configured to distribute traffic to a plurality of wavelength division multiplexer (WDM) modules. The system further comprises a first WDM module and a second WDM module. The first and second WDM modules each comprise a plurality of tunable optical transmitters, with each transmitter associated with a different wavelength band of a plurality of wavelength bands. Each transmitter in the first and second WDM modules is also tuned to transmit optical signals in channels included within the associated wavelength band of the transmitter. The first and second WDM modules each comprise a multiplexer configured to combine the optical signals transmitted from the plurality of transmitters into optical signals. The system further comprises a cyclic multiplexer configured to combine the optical signals from the first and second WDM modules into an optical output signal.

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: A wavelength division multiplexing passive optical network (WPON) comprising an optical line terminal (OLT) and a plurality of optical network units (ONUs) coupled to the OLT via a power optical splitter. The OLT is configured to monitor wavelengths in use by the ONUs and to divide upstream traffic from the ONUs into multiple channels using tunable filters. Also disclosed is an OLT for a PON, the OLT comprising a plurality of receivers and a plurality of tunable filters corresponding to each of the receivers. The OLT also comprises channel control logic coupled to the tunable filters, wherein the channel control logic is configured to detect a plurality of wavelengths in use for upstream traffic in the PON and to divide the upstream traffic into multiple channels using the tunable filters. Included is a method for managing upstream traffic in a PON, the method comprising monitoring, by a processor, wavelengths in use for upstream traffic in the PON.

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: Dynamic optical wavebands are disclosed that allow a plurality of user streams having a common destination node to be positioned in a substantially adjacent non-overlapping manner on a spectrum for treatment as a routable entity. Each waveband has an associated center wavelength and spectral extent. The plurality of user streams can optionally be encrypted using a corresponding cipher. Wavebands that are received by a network node are filtered so that individual wavebands can be isolated, if necessary. For example, individual wavebands can be switched to an appropriate output node for forwarding in the optical network. In addition, the center wavelength and spectral extent of a waveband can be converted, if necessary, to position the waveband substantially spectrally adjacent to another waveband sharing a common path portion. In this manner, the substantially spectrally adjacent wavebands can be treated as an aggregated waveband for the common portion of a path.

Abstract: The present invention relates to a multi-channel provision system for a wired network. The multi-channel provision system of the present invention includes a tap-off unit (330) for dividing a frequency band, assigned to a wired network for network communication, and providing resultant frequency bands to respective subscriber units belonging thereto. An optical network device (100) is disposed at a node where one or more sectors, divided according to a number of subscriber units that enable network access through the wired network, branch off. The optical network device (100) provides a frequency band for network access to each sector so that a same frequency band is assigned to each sector, thus generating a multi-channel for the frequency band, and reusing the frequency band, assigned to the wired network, a number of times corresponding to the number of the sectors through generation of the multi-channel.

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 passive optical network (PON) system comprising a plurality of optical network units (ONUs) having one downstream receiver and one upstream transmitter, an optical line terminal (OLT) having a downstream transmitter and a plurality of upstream receivers, wherein each upstream receiver is associated with a subset of the ONUs, and an optical distribution network (ODN) that connects the OLT to the ONUs is disclosed. An OLT for a PON, comprising a downstream transmitter, and a plurality of upstream receivers, wherein a downstream transmitter bandwidth is greater than each upstream receiver bandwidth is also disclosed. A network component comprising a processor configured to implement a method comprising determining a downstream bandwidth and an upstream bandwidth for a PON, and increasing a number of upstream channels per downstream channel for the PON when asymmetry between the downstream bandwidth and the upstream bandwidth is greater than a threshold amount is also disclosed.

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: In accordance with the teachings of the present invention, a system and method for managing wavelength drift in an optical network is provided. In a particular embodiment, the method includes receiving traffic in one or more optical channels transmitted by one or more transmitters, each channel having successive timeslots, each transmitter assigned to transmit in a channel in allocated timeslots in the channel. The method also includes determining whether the traffic received in a particular channel in a particular timeslot was transmitted by one of the transmitters that was not assigned to transmit in the particular channel.

Abstract: An optical spectrum monitor includes a tunable optical detector that receives optical channel monitoring signals from an optical channel and receives a control signal that selects a frequency of an optical channel monitoring signal for detection. The tunable optical detector detects the optical channel monitoring signal selected by the control signal and generates an electrical signal related to a power of the detected optical channel monitoring signal. A processor analyzes a plurality of differences between selected optical channel monitoring frequencies and their corresponding ITU frequencies and then generates the control signal at the output that corrects for at least one of systematic band offset and systematic band tilt in the optical channel monitoring frequency.

Abstract: Systems and methods which facilitate broadband transmission of signals using a delivery point tuning technique to provide a extended frequency passive optical network (EF-PON) are shown. Embodiments provide an extended frequency optical transition node (EF-OTN) at each of a plurality of delivery points to provide a frequency translation interface between equipment disposed at the delivery point locations and a network utilizing transmission bandwidth which is incompatible with that equipment. The foregoing frequency conversion is preferably transparent to the equipment receiving the network transmissions. Embodiments utilize a single wideband tuner for providing frequency conversion with respect to a plurality of equipment disposed a delivery point.

Abstract: An optical communication system and method for use in communicating data between nodes using wavelength division multiplexing includes an optical backbone to provide an optical pathway between the nodes. Arbitration information on a dedicated arbitration wavelength transmitted during an arbitration cycle is used by the plurality of nodes to select one of a plurality of wavelengths at which to transmit data during a subsequent data cycle.

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: A passive optical network (PON) device, system and method include an optical line terminal (OLT) receiver configured to receive multiple signals at different wavelengths simultaneously and enable multiple transmitters to operate at the same time during one upstream time slot. The optical line terminal employs Orthogonal Frequency Division Multiple Access (OFDMA) to transparently support a plurality of applications and enable dynamic bandwidth allocation among these applications where the bandwidth is allocated in two dimensional frequency and time space.

Abstract: Disclosed is a system and a method for polling in an Ethernet Passive Optical Network (EPON). The system includes: multiple Optical Network Units (ONUs) for sharing optical channels of the EPON with one another and transmitting traffic; and an Optical Line Terminal (OLT) for discriminating a plurality of ONUs gaining access to the EPON among the multiple ONUs and then collecting routing information on the plurality of ONUs gaining access to the EPON, and for classifying the plurality of ONUs gaining access to the EPON into two or more ONU groups according to the collected routing information and then carrying out forming a polling cycle and allocating bandwidth on each ONU group. Therefore, a transmission idle period in a traffic channel is not only minimized, but an availability ratio of traffic channels can also be maximized.