Abstract: An optical modulator includes: a modulator including an optical waveguide provided in a semiconductor substrate having an electro-optical effect and an electrode to apply an electric field depending on a bias voltage and a modulation signal to the optical waveguide; a driver circuit to generate a modulation signal in accordance with an input signal; a superimposer to superimpose a reference signal on the bias voltage, the reference signal having lower frequency than the modulation signal; and a controller to control a bias voltage in a direction orthogonal to a modulation direction of the modulator based on the frequency component of the reference signal extracted from a modulated optical signal generated by the modulator.

Abstract: A receiving unit using a voltage-controlled oscillator is allowed to compensate for the frequency characteristics of the voltage-controlled oscillator resulting from temperature change, without adding a capacitive element for temperature compensation. A receiving unit and an optical line terminal include a clock and data recovery circuit that extracts a clock signal and a data signal from a received signal, and have: a calibrator that calibrates an oscillation frequency of a voltage-controlled oscillator included in the clock and data recovery circuit; and a managing unit having a function of managing a schedule for receiving signals, the managing unit selecting a time where a duration of a certain state meets a time required for calibration by the calibrator to thereby output a reset signal (calibration instruction signal) to the calibrator, the state having no received signal (upstream signal) from which a clock signal and a data signal are to be extracted.

Abstract: An example is a bandwidth control method employed in an optical line terminal including: determining a first time point at which a first optical network unit starts the processing of transitioning between the states in a case where the first optical network unit is to be transitioned between the states; transmitting a state control signal containing the first time point to the first optical network unit in order to control the first optical network unit to start the processing of transitioning between the states; and stopping allocating a bandwidth used to transmit a signal to the optical line terminal to a second optical network unit during a period from the first time point until it is determined that the first optical network unit has finished the processing of transitioning between the states.

Abstract: The invention relates to techniques for controlling a dynamic hitless resizing in data transport networks. According to a method aspect of the invention, a network connection comprises M tributary slots defined in a payload area of a higher order transport scheme of the data transport network and the method comprises the steps of receiving a connection resize control signal at each of the nodes along the path of the network connection; adding at each node along the path in response to the connection resize control signal a second set of N tributary slots to the first set of the M tributary slots, such that the network connection comprises M+N tributary slots; and increasing, after M+N tributary slots are available for the network connection at each node along the path, a transport data rate of the network connection.

Abstract: There are provided an optical transponder having a first end and a second end, as well as an electric switch having the transponder. The transponder includes an optical interface, at the first end, having a variable rate optical transmitter and a variable rate optical receiver to respectively transmit and receive signals using at least one of different bandwidths and different bit rates. The transponder further includes an electrical interface, at the second end, having an electrical interface throughput matching an optical capacity of the optical interface. The transponder also includes a processor for controlling the optical capacity.

Abstract: Methods, systems, and apparatuses for time-based composite modulation of an optical carrier signal are provided. Time-based composite modulation includes determining a plurality of fixed time slots for the optical carrier signal, wherein the plurality of fixed time slots comprise a time-division-multiplexing frame. Determining a modulation format for each fixed time slot of the time-division-multiplexing frame, wherein a transport spectral efficiency of the modulation format determined for a first fixed time slot is different from a transport spectral efficiency of the modulation format determined for a second fixed time slot, and determining a number of binary bits for each fixed time slot of the time-division-multiplexing frame, wherein the number of binary bits for a fixed time slot is based on the modulation format determined for the fixed time slot.

Abstract: An exemplary method and apparatus are provided for data transmission in an optical transport network that includes receiving client data from a client, mapping the client data into a frame structure, mapping the frame structure into tributary slots of a data transport structure, and transmitting the data transport structure. The data transport structure contains a fixed number of tributary slots and the size of the frame structure is selectable in granularity of the tributary slots of the data transport structure.

Abstract: A control device (13) for scheduling the transmission of signals from a plurality of transmitters (14, 15, 16, 17, 18, 19, 20, 21). The control device (13) comprises an evaluation element (22) arranged to determine the power level of the signals received from each of the transmitters and a scheduling element (23) adapted to determine a transmit schedule comprising the order that the plurality of transmitters should transmit based on the power levels of the signals received from the transmitters (14, 15, 16, 17, 18, 19, 20, 21). A method of operation and a node incorporating the control device is also disclosed.

Abstract: A network design method that determines a TDM transmission line for accommodating a given demand includes: extracting an available demand from among a plurality of provided demands; calculating a total bandwidth of the extracted available demand; sequentially selecting the plurality of demands; generating candidates for a combination of TDM transmission lines that accommodate the selected demand; and determining a combination of TDM transmission lines that accommodates the selected demand from among the candidates for the combination of TDM transmission lines. The generating process includes: extracting a TDM transmission line with a band utilization efficiency higher than a specified threshold from among TDM transmission lines including the selected demand as an available demand; and generating candidates for a combination of TDM transmission lines that accommodate the selected demand using the extracted TDM transmission line.

Abstract: The fabric card includes at least one fabric card chip and at least two fabric card connector groups, where each fabric card connector group of the at least two fabric card connector groups includes at least two fabric card connectors, the number of fabric card chips is less than the number of at least two fabric card connector groups, each fabric card chip of the at least one fabric card chip connects to all fabric card connectors in at least one fabric card connector group, all fabric card connectors in the fabric card connector group that connect to the fabric card chip exchange data using the fabric card chip. This fully utilizes an exchange capability of the fabric card chip and saves system resources.

Abstract: The present invention relates to a method for negotiating link capability information. The method includes: After a higher order optical channel data unit (ODU) link is established, a second node receives first higher order ODU link capability information supported by a first node at one end of the link, where the second node is located at the other end of the link; determines link capability information according to the first higher order ODU link capability information and second higher order ODU link capability information that is supported by the second node; and sends the link capability information to the first node; or sends the second higher order ODU link capability information to the first node, so that the first node determines the link capability information according to the first higher order ODU link capability information and the second higher order ODU link capability information.

Abstract: When an ONU accommodating range is enlarged, and ONUs shorter and ONUs longer in a communication path to an OLT are accommodated in a PON at the same time, there is a need to change a light intensity at the time of transmitting a downstream signal in order that both of the ONUs receive a downstream signal from the OLT. When a near-end ONU receives a signal having a light intensity necessary to communicate between the OLT and a far-end ONU, there arises such a problem that the light intensity is as high as an ONU receiver fails. In order to eliminate the ONU failure of the above problem, prior to transmission of the downstream signal, a downstream signal transmission schedule (downstream light intensity map) is notified to all of the ONUs. An optical transceiver of the OLT has a function of adjusting an output light intensity, and adjusts the light intensity to values receivable by the individual ONUs when the signal arrives at the respective ONUs according to route distances to the respective ONUs.

Abstract: Provided is an optical network system and optical network unit (ONU) structure enabling a passive optical access network having a meshed structure with at least two central nodes and plurality of ONUs. One embodiment employs a partially or fully meshed structure of optical fibers between customer locations and multiple optical line terminal (OLT) locations creating a passive optical access network. The ONUs can communicate with a neighboring OLT or ONU using a symmetrical or asymmetrical TDM scheme, and convert between the different TDM schemes. For this purpose, the ONU structure includes two transceiver units, one connected to the western network port and the other to the eastern. The ONU can establish communication between either network port and a further ONU or an OLT, with the ONU controller adapted for passing through data, and converting TDM schemes.

Abstract: Methods and apparatus for line coding in a communications network are described. According to one embodiment of the invention, downstream communications traffic bits are received and mapped into downstream bit positions of a transmission structure. A pre-selected bit in each upstream bit positions of the transmission structure is provided to form a downstream transmission structure. A downstream optical signal carrying the downstream transmission structure is generated for transmission. Upstream communications traffic bits are also received and mapped into the upstream bit positions of the transmission structure to form an upstream transmission structure. An upstream optical signal carrying the upstream transmission structure is generated for transmission.

Abstract: Embodiments of the present invention provide a repeater, including a local unit and a remote unit. The local unit includes a base station interface unit, multiple local basic units and a controller. The remote unit includes multiple remote basic units. The controller is configured to generate, according to a down-tilt angle and/or azimuth angle of a downlink signal instructed by a control instruction, a downlink signal phase for each remote basic unit. The multiple local basic units each are configured to perform, according to the downlink signal phase generated by the controller for a corresponding remote basic unit, phase adjustment on the downlink signal sent by the base station interface unit. The multiple remote basic units each are configured to receive the downlink signal sent by a corresponding local basic unit and to send the downlink signal.

Abstract: A method, comprises measuring, by circuitry of a computer system, a first bandwidth of data traffic of a transport path over a time period, the transport path passing through a plurality of nodes and conforming to a protocol using a number of time slots to allocate a second bandwidth to the transport path. The method further includes passing a signal, from the computer system to at least one of the nodes of the transport path, the signal including at least one instruction that when executed by circuitry of the at least one node causes a change to the number of time slots allocated to the transport path.

Abstract: Disclosed herein is a Passive Optical Network (PON) system and method for detecting a fault in an Optical Network terminal (ONT). The PON system for detecting a fault in an ONT includes a plurality of ONTs for outputting optical signals in time slots allocated thereto in a time division access control manner and having at least one virtual ONT. An Optical Line Terminal (OLT) receives the optical signals output from the plurality of ONTs in the time division access control manner, and then detects a faulty ONT. According to the present invention, a faulty ONT that continuously outputs signals can be detected and action can be rapidly taken against system faults when a virtual ONT is formed in a plurality of ONTs connected to an OLT and then an optical signal in the section of the virtual ONT is detected, thus providing a reliable service.

Abstract: An apparatus comprising a receiver configured to receive a plurality of transmission requests from a plurality of end nodes via an optical network and an electrical network, a processor coupled to the receiver and configured to dynamically allocate optical transmission time slots to the end nodes according to measured RTTs of the end nodes, and a transmitter coupled to the processor and configured to transmit the allocated transmission time slots to the end nodes. Also disclosed is a method performed by an OLT comprising receiving a plurality of transmission requests from a plurality of network units via a PON and an electrical network, and allocating optical transmission time slots to the network units dynamically according to measured RTTs of the network units.

Abstract: A burst transmission method and a receiver resetting method and apparatus in a Passive Optical Network (PON) are provided. A burst receiver resetting method in a PON includes: receiving a preamble sequence and synchronizing data; after synchronizing the data, continuing to receive the data, and matching a Burst Terminator (BT); and resetting a receiver after successfully matching the BT. Meanwhile, an apparatus for implementing the method and a corresponding burst data transmission method are provided. By using the burst receiver resetting method and apparatus in the PON and the corresponding burst transmission method at an Optical Network Unit (ONU) burst transmission end, a Reach Extender (RE) does not need to unpack upstream burst bandwidth allocation information carried in downstream data.

Abstract: The present invention discloses a method for transmitting multimedia broadcast multicast services, comprising the following steps: a Time Division Duplex system divides a time slot for bearing multimedia broadcast multicast services into code channels; each multimedia broadcast multicast service to be transmitted is borne on a corresponding divided code channel, and is transmitted to a user equipment based on the single frequency network mode of the multimedia broadcast multicast service. The present invention also discloses a method for receiving multimedia broadcast multicast services, and apparatus for transmitting and receiving multimedia broadcast multicast services, such that time slot resources for bearing multimedia broadcast multicast services are utilized more sufficiently.

Abstract: An optical fiber transmission distribution assembly, wherein the assembly comprises at least a first splitter having a first split ratio of 1:x (where x is an integer) connected to optical drop cables leading to subscribers, and at least a second splitter having a second split ratio of 1:y (where y is an integer and is different from x), and transfer means whereby an optical drop cable connected to the first splitter can be transferred to receive split optical signals from the second splitter, thereby enabling the signal in the transferred drop cable to be further split by addition of a third splitter at a ratio of 1:p (where p is an integer), to provide p subscriber connection points each having a 1:p*y split ratio at the subscriber end of the transferred drop cable.

Abstract: The present invention provides a method, apparatus and system for transmitting and receiving a client signal. A client signal is mapped to a low-order ODU via a GFP scheme, wherein the low-order ODU is sized to M equal sized timeslots of a high-order OPUk, wherein the high-order OPUk is divided into N equal sized timeslots, wherein M is any one of a group from 1 to N; wherein if k=2, then N=8, if k=3, then N=32 and if k=4, then N=80. The low-order ODU with the client signal is mapped to M equal sized timeslots of the high-order OPUk via a GMP scheme; and an OTU with the high-order OPUk and overheads is formed, and then the OTU is transmitted.

Abstract: Techniques for converting signal and idler photons generated by a nonlinear optical system into a deterministic stream of single photons including receiving a heralded, nondeterministic source of signal and idler photons from the nonlinear optical process, separating one or more received signal photons from one or more received temporally corresponding idler photons, determining whether at least one of the one or more signal photons should be variably delayed, and if so, determining a delay length, and variably delaying the emission of one of the one or more signal photons, if any, by the determined delay length.

Abstract: A passive optical network (PON) component comprising a processor coupled to a plurality of receivers, the processor configured to monitor a plurality of drifting laser wavelengths and cause the drifting laser wavelengths to be tuned to a plurality of pass-bands. Also disclosed is an optical network unit (ONU) comprising a receiver, a transmitter coupled to the receiver, and a partially-tunable laser coupled to the transmitter and having a drifting laser wavelength, wherein the drifting laser wavelength is periodically tuned to one of a plurality of pass-bands. Included is a method comprising monitoring a plurality of drifting laser wavelengths associated with a plurality of pass-bands, and reconfiguring a plurality of time division multiple access (TDMA) timeslots when one of the drifting laser wavelengths migrates from one pass-band to another pass-band.

Abstract: A GPON module comprises a housing and a circuit board disposed in the housing. The circuit board further includes ground lines that substantially isolate regions of the circuit board, an electro-optical interface for converting an inbound optical signal to an electrical signal and processing circuitry that is arranged to provide an electrical RF signal to an RF interface. The RF interface comprises a three-pin RF connector exposed from the housing, wherein the RF connector is coupled directly to the circuit board, and two of the three pins are coupled to ground.

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

Abstract: A method of allocating upstream bandwidth on a network comprising mapping an integer portion of a value obtained from a grant start time into a symbol number of a data frame on a coaxial segment of the network, wherein the value comprises the grant start time in units of a length of a data frame in the coaxial segment of a network, and wherein the length of the data frame comprises a preselected number of units of time defined in an optical segment of a network; mapping a fractional portion of the value obtained from the grant start time into a subcarrier number of the data frame; and mapping a grant length into a number subcarriers of the data frame.

Abstract: The present invention discloses a method and system for accurate time transfer in PON. An Optical Line Terminal (OLT) ranges Optical Network Units (ONUs) and obtains ranging information, then, triggered by the periodic Pulse per n Second (PPnS), generates a PPnS timestamp based on the local reference counter and the Time of Day (TOD) above second; OLT transmits the ranging information, the periodic PPnS timestamp and TOD to ONUs; ONUs predicts the time of the next second according to said periodic PPnS timestamp, TOD and ranging information, and outputs the corresponding PPnS. The invention is characterized by the combination of the features of PON point to multi-point and PON ranging into its time transfer method, the high accuracy of time transfer, and the low hardware costs for OLT and ONU, as well as the extremely small bandwidth occupancy.

Abstract: There is provided a frame converter that writes input data included in an input frame to a buffer to accumulate the input data and outputs data read from the buffer as output data included in an output frame, the frame converter includes a setting unit configured to set a time interval from start of resizing of data rate of the input data to start of resizing of data rate of the output data when resizing of an accumulation amount in the buffer is performed in which data rates of the input data and the output data vary, and an adjustment unit configured to adjust to approximate the data rate of the output data to the data rate of the input data after the time interval has elapsed since the start of resizing of data rate of the input data.

Abstract: The embodiments of the present invention relate to communications technology, and disclose an optical power measurement method, an Optical Line Terminal (OLT), and an Optical Network Unit (ONU). The method includes: generating a Physical Layer Operation Administration Maintenance (PLOAM) message that includes an identifier of at least one ONU to be measured and information about a time bucket that is allocated to the ONU to be measured and is used for sending upstream optical signals; sending the PLOAM message to the multiple ONUs; receiving the upstream optical signals that are sent, in the allocated time bucket, by the ONU to be measured; and detecting the received upstream optical signals, and determining the optical power of the upstream optical signals. The present invention avoid waste of bandwidth caused in the prior art when the DBA is required to allocate bandwidth to the ONU to be measured for the purpose of detecting the optical power.

Abstract: There is a need to recover an ONU from a sleep state for communication with the PON before a specified sleep cancel time in a short period of time without degrading the band use efficiency. An OLT manages an electric state of each ONU connected to a PON. When at least one ONU is in sleep mode, the OLT transmits a grant to allocate a band for a sleep cancel report to the ONU. When the sleep-mode ONU requires communication, the ONU transmits the sleep cancel report to the OLT using the band for the sleep cancel report. When receiving the sleep cancel report, the OLT changes the managed ONU to a normal state and resumes the communication with the PON.

Abstract: An optical management node comprising a memory comprising instructions, a processor coupled to the memory and configured execute the instructions, wherein executing the instructions causes the processor to schedule data transmissions across an electrical network between a plurality of user terminals and an optoelectrical interface by using time division multiplexing or time division multiple access based on optimization of crosstalk performance of electrical lines of the electrical network, and a transmitter coupled to the processor and configured to transmit schedule information to the optoelectrical interface via an optical network. Also disclosed is a method implemented in a management node comprising scheduling data transmissions with a plurality of user terminals across a Digital Subscriber Line (DSL) network using time division scheduling based on optimization of crosstalk performance of DSL lines of the DSL network, and transmitting schedule information to the user terminals via an optical network.

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 system, method, and optical switch for communicating timing. A determination is made whether one of a number of data streams are available. Packets are received at a remote node in response to determining one of the number of data streams is available. A timing characteristic of the at least one of the packets is associated with a tick of a reference clock. The tick of the reference clock is extracted utilizing the timing characteristic of the at least one of the packets. A secondary clock is disciplined with the reference clock by adjusting the secondary clock based on a difference between times measured by the reference clock and the secondary clock to generate a clock signal. The clock signal is communicated to one or more interfaces for distributing.

Abstract: The present invention and its embodiments are made to provide for dynamic hitless resizing in optical transport network without any identification of matching time slots by the Network Management System (NMS) or any control plane signaling including Generalised Multi Protocol Label Switching (GMPLS). An aspect of the invention provides for a method of hitless ODUflex connection resizing in an optical transport network by incrementing or decrementing the ODUflex connection between the nodes, based on an indication command given to a source node for bandwidth increase or decrease, by identifying and matching at least one time slot through Link Connection Resizing (LCR) protocol message exchanges. Another aspect of the invention provides for a method of hitless ODUflex connection resizing in an optical transport network by decrementing the matching time slot used for the incrementing operation, in case of unsuccessful incrementing operation between nodes.

Abstract: Methods, systems, and computer-readable media provide for notifying an optical line termination (OLT) of a power failure. According to embodiments, a method for notifying an OLT of a power failure is provided. According to the method, a notification of a power failure at an optical network termination (ONT) is received. In response to receiving the notification, power is retrieved from a dedicated power storage unit dedicated to providing power for the transmission of a dying gasp alarm. The dying gasp alarm is transmitted to the OLT utilizing at least a portion of the power from the dedicated power storage unit. The dying gasp alarm notifies the OLT of the power failure.

Abstract: A system for transporting a plurality of analog and/or digital signals over an optical fiber can include one or more master modems for modulating digital signals and/or RF inserters modulating video signals. The RF signals from the modem(s)/RF inserters are up-converted resulting in frequency bands that are non-overlapping and are spaced apart within a single sub-octave. The sub-octave signal is then converted into an optical signal and directed onto an end of an optical fiber. At the downstream end of the optical fiber, the received optical signal is converted to an RF signal at an optical receiver. The RF signal is then filtered, down-converted and directed to a selected coaxial distribution unit. From the coaxial distribution unit, the RF signal is demodulated, e.g. at a slave modem, to recover the initial analog and/or digital signal.

Abstract: Consistent with the present disclosure, based on system requirements or in response to an increase in optical signal-to-noise level of an optical channel, such as a WDM channel, additional FEC bits are inserted into and replace selected data payload bits in each frame carried by the channel. The replaced data payload bits may then be transmitted in subsequent frames on the same channel. As a result, the transmitted frames have a reduced data payload rate, but a higher coding gain. Alternatively, the replaced data payload bits may be included in frames transmitted on another optical channel. In that case, the frames carried by the two channels typically have the same bit length or number of bits and may thus be compliant with the frame length requirements of G.709, for example. Preferably, the number of coding bits may be changed dynamically to obtain different coding gains.

Abstract: A multiport passive optical signal sharing device enabling optical signals received by each of a first plurality of ports of the device to be transmitted to all of the ports of a second plurality of ports of the device. The device includes a first coupling mechanism adapted to combine signals received by each port of the first plurality of ports of said device into a first optical signal, the first optical signal being transmitted over a bi-directional optical link. The device further includes a second coupling mechanism and guide for redirecting the first optical signal in a form of a second optical signal into the bi-directional optical link, in the opposite direction from that of the first optical signal, the first coupling mechanism being adapted to duplicate the second optical signal on each port of the second plurality of ports of the device.

Abstract: A dynamic bandwidth allocation apparatus of a passive optical network detects guarantee agreement information of each transmission container (T-CONT) queue of at least one optical network unit (ONU) that is connected to the dynamic bandwidth allocation apparatus in order to dynamically allocate a bandwidth is provided. The dynamic bandwidth allocation apparatus sets a queue threshold according to a buffer size of each T-CONT queue of at least one ONU, and calculates a service level agreement (SLA) parameter of at least one ONU using guarantee agreement information and a queue threshold. The dynamic bandwidth allocation apparatus allocates a bandwidth for every frame of each ONU using each SLA parameter of at least one ONU.

Abstract: A drive circuit includes a bias current supply circuit for supplying a bias current to a light-emitting device for transmitting an optical signal, the light-emitting device included in a light-emitting circuit; and a modulation current supply circuit for supplying a modulation current of a magnitude according to a logical value of data to be transmitted, to the light-emitting device. The modulation current supply circuit includes a differential drive circuit for switching whether to supply a current to the light-emitting device, according to the logical value of the data; and a termination resistor connected between differential outputs of the differential drive circuit. The differential drive circuit and the light-emitting circuit are DC-coupled to each other, and power supply of the current supplied to the light-emitting device by the differential drive circuit is supplied from the light-emitting circuit.

Abstract: Disclosed is an optical amplifier which includes an upward optical amplifier configured to amplify an input upward optical signal of an input optical signal; and a control circuit configured to control an operation of the upward optical amplifier according to whether an upward stream is detected from the input upward optical signal.

Abstract: An optical-coax unit (OCU) includes an optical PHY to receive and transmit optical signals and a coax PHY to receive and transmit coax signals. The OCU also includes a media-independent interface to provide a first continuous bitstream from the optical PHY to the coax PHY and a second continuous bitstream from the coax PHY to the optical PHY. The first continuous bitstream corresponds to received optical signals and transmitted coax signals, and the second continuous bitstream corresponds to received coax signals and transmitted optical signals.

Abstract: The present invention relates to an optical transmitter for transmitting data. The optical transmitter includes a pulse generator for generating N data streams overlapping in time from a de-multiplexed data source. Each respective data stream has pulses with shapes unique to that respective data stream. The transmitter also includes an optical source optically transmitting an output pulse that is generated by summing the uniquely shaped pulses from each respective data stream that are overlapping in time. Each output pulse represents N bits of the data source, where N>1.

Abstract: Systems, apparatus and method for modulating digital data onto an optical carrier to produce a modulated optical carrier in which symbol-modulated optical signals of orthogonal polarizations are temporally interleaved and adapted to be processed by electronic time-division demultiplexing to recover the digital data modulated onto the orthogonal polarizations of the optical signals.

Abstract: A system and an associated method of bidirectional optical transmission between a central terminal (101) and a plurality of client terminals (11, 12) via a passive optical network (PON) (3), wherein the conversion of an OTDM signal into a WDM signal (respectively the conversion of a WDM signal into an OTDM signal) is effected by an optical converter (20) (respectively 21) by a soliton trapping effect during a downlink (respectively uplink) transmission stage.

Abstract: The present invention relates to transmission and reception of data over a plastic optical fibre. In particular, the present invention provides for transmission and reception over the plastic optical fibre a particularly suitable frame structure. The frame structure includes a synchronization sequence and portions of user data alternating with alternating reference signal portions and control data portions. The length of the user data portions may be equal, the length of the synchronization sequence and the control data and reference signal portions may also be equal. The distances between the synchronization sequence and the reference signal portions and the control data portions are advantageously equal. The alternating of data and additional information avoids data decoding latency while maintaining the rate necessary for the additional information.

Abstract: A technique for forwarding downstream packets in a GPON comprising an OLT unit having a physical PON port connected to N Optical Network Termination (ONT) units by optical fibers. The physical PON port accommodates N individual virtual GEM ports terminated with the N ONT units (ONTs) which form N:1 service. The technique comprises assigning in the physical port of the OLT unit a virtual GEM port being a shared broadcast GEM port terminated with all the N ONTs of the N:1 service. Those downstream packets applied to the physical PON port, which would otherwise be flooded—such as broadcast packets or packets having unknown destination address—will now be forwarded only via the shared broadcast GEM port.

Abstract: One embodiment of the present invention provides a system that accommodates different clock frequencies in an Ethernet passive optical network (EPON). The system receives a signal from an optical line terminal (OLT) at an optical network unit (ONU) and derives an OLT clock. The system also maintains a local clock. The system further receives from the OLT an assignment for an upstream transmission window, during which the ONU can transmit an upstream data burst to the OLT based on the local clock. The system adjusts the number of bits of the data burst without affecting the payload data carried in the data burst, thereby allowing the data burst to fit properly within the upstream transmission window and compensating for frequency differences between the local clock and the OLT clock. The system transmits the data burst based on the local clock in the upstream transmission window.

Abstract: Systems, methods, and computer-readable media for propagating a timing signal over a Dense Wave Division Multiplexer fiber optic network by polarity modulation of the Optical Service Channel are provided. The systems, methods, and computer-readable media may make the timing signal available for use by devices that require a reference timing source.