Abstract: Based on the demand information etc., an accommodation designing problem and an assignment problem are solved in a conventional method to design a network. It is confirmed whether or not a restriction on the number of wavelengths for each link is observed. When there are links exceeding the restriction of the number of wavelengths, the number of available wavelengths is subtracted from the first link having the largest number of excess wavelengths and the second link farthest from the first link in the links, and the result is set as a wavelength number limited value, thereby performing a network designing process again.

Abstract: Differential dynamic content delivery including providing a session document for a presentation, wherein the session document includes a session grammar and a session structured document; selecting from the session structured document a classified structural element in dependence upon user classifications of a user participant in the presentation; presenting the selected structural element to the user; streaming presentation speech to the user including individual speech from at least one user participating in the presentation; converting the presentation speech to text; detecting whether the presentation speech contains simultaneous individual speech from two or more users; and displaying the text if the presentation speech contains simultaneous individual speech from two or more users.

Abstract: Provided is a time division multiple access over wavelength division multiplexed passive optical network (TDM-over-WDM-PON) system. According to the TDM-over-WDM-PON system, a downstream optical signal is separated according to a wavelength in a remote node, transmitted to an optical amplifying device located in subscriber equipment, amplified in the optical amplifying device, transmitted back to the remote node, and then transmitted to the subscriber equipment. Also, an upstream optical signal is transmitted to a wavelength converting device located in the subscriber equipment from the remote node, wavelength-converted in the wavelength converting device, returned back to the remote node, and then transmitted to a central office.

Abstract: A data transport card comprising an interface to receive high speed data streams from at least one client, and a pluggable conversion module which converts said data streams into optical data signals and couples these optical data signals into at least one wavelength division multiplexing channel for transport of said optical data signals via an optical fiber.

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

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

Abstract: A transmitter for generating, starting from a data-packet traffic at input, flows of information to be conveyed via optical signals with different wavelengths towards a plurality of targets in a communications network, the transmitter including: a destination decoder to identify, for each packet in the input packet traffic, a respective destination target in the plurality of targets; a plurality of emitter modules operating at different wavelengths for converting the electrical signals into optical signals; and a de-multiplexer, which is controlled by the destination decoder and is able to drive the emitter modules by sending selectively to each emitter module the electrical signals corresponding to a given packet of the input packet traffic according to the respective destination target identified by the destination decoder. A serialization module is set upstream of the de-multiplexer for converting the packet traffic into a serial flow of bits.

Abstract: A quantum cryptography communication apparatus performs quantum cryptography communication between a transmitter and a receiver. The quantum cryptography communication apparatus includes first communicating unit transmitting and receiving a communication signal including relatively strong pulse light between the transmitter and the receiver, and second communicating unit transmitting and receiving a relatively weak quantum cryptography signal between the transmitter and the receiver in a period in which the communication signal is off and the attitude axis for the receiver can be adjusted to that for the transmitter by the second communicating unit.

Abstract: An optical network unit useful in a passive optical network has capability for automatic shutdown upon detection of a malfunction, thereby protecting the integrity of upstream data transmitted in the network. The unit detects the generation of upstream light during intervals in which transmission is not authorized. In response, the light source of the unit is deactivated to prevent collisions with upstream data from other optical network units in the network.

Abstract: A system and method for handling accesses by nodes connected to a ring network, using time division multiplexing (TDM). The system includes: nodes capable of receiving only an optical signal of a wavelength or positional space allocated to the node, and of transmitting optical signals of wavelengths allocated to other nodes; and a ring network that performs TDM transmission of optical signals. The ring network has slots for transmitting optical signals of individual wavelengths. Information indicates whether an optical signal to be transmitted exists in each of the slots. Nodes include means for updating the information indicating that the optical signal exists and determining means for updating the information and determining, on the basis of the information, whether to transmit the optical signal.

Abstract: A method and apparatus for enabling multiple optical line termination (OLT) devices to share a feeder fiber are disclosed. For example, the optical network comprises a plurality of optical line termination (OLT) devices, where each OLT device having a transceiver for sending and receiving optical signals. The optical network further comprises a wave division multiplexer (WDM) combiner, coupled to the plurality of OLT devices, for combining optical signals received from the plurality of OLT devices. The optical network further comprises an optical extender box comprising at least one hybrid SOA-Raman amplifier, wherein the optical extender box is coupled to the WDM combiner via a first standard single mode fiber section. Finally, the optical network further comprises at least one optical splitter coupled to the optical extender box via a second standard single mode fiber section.

Abstract: An optical pulse time spreading apparatus wherein an optical splitter divides an input optical pulse into first to U-th input optical pulses; first to U-th optical pulse time spreaders respectively have the first to U-th input optical pulses input thereto and output first to U-th chip pulse sequences each consisting of N chip pulses from a first to an N-th chip pulse arranged in order on a time axis into which the input optical pulse is time-spread; and an interval between adjacent ones of unit FBGs arranged in a p-th optical pulse time spreader and a Bragg reflection wavelength of the unit FBGs in the p-th optical pulse time spreader are set such that spectra of the first to U-th chip pulse sequences are different from each other.

Abstract: A packet-switched WDMA ring network has an architecture utilizing packet stacking and unstacking for enabling nodes to access the entire link capacity by transmitting and receiving packets on available wavelengths. Packets are added and dropped from the ring by optical switches. A flexible credit-based MAC protocol along with an admission algorithm enhance the network throughput capacity.

Abstract: The present disclosure provides systems and methods for real-time, in-service latency measurements over optical links that may be further integrated within various optical control planes. The present invention may utilize minimal unused overhead to calculate latency of an optical line through a transport network. The present invention utilizes timers at two end-point nodes associated with the optical line, and includes a mechanism to filter out frame skew between the nodes. Advantageously, the present invention provides a highly accurate latency measurement that may calculate latency on links as small as one meter, an in-service algorithm operable without network impact, and may be integrated with an optical control plane to automatically provide administrative weight variables associated with link costs.

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: The present invention provides a method of generating time-division multiplexed encoded transmission signals, including encoding optical pulse signals for each of a plural multiplexed channels and generating a transmission signal for each channel, performing time division multiplexing on first and second transmission signals and generating a 2-channel multiplexed signal modulating the multiplexed signal with a modulation signal having a frequency of (F??f) Hz, detecting a strength of a ?f Hz frequency component of the multiplexed signal changing a time delay amount of the second transmission signal with respect to the first transmission signal, and determining a time delay amount at which a strength of the ?f Hz frequency component is minimized and adjusting the transmission signals of the individual channels such that they are arranged at equidistant intervals on a time axis.

Abstract: A quantum communication system comprising a sending unit and a receiving unit, said sending unit comprising a photon source assembly configured to output a stream of pulses of light having at least two different intensities and a memory configured to store information for determining which pulses should be reference pulses and which pulses should be data pulses, the average intensity of reference pulses being different to the average intensity of data pulses, the receiving unit comprising a memory for storing information for identifying the position of reference pulses within the stream of pulses and a processor for determining the calibration of the quantum communication system from the reference pulses.

Abstract: A data transmission apparatus for use in a separate-type base station is provided. The data transmission apparatus includes: a digital unit configured to generate first data that includes transmission method information indicating a selected transmission method and data to be transmitted; a time-division synchronization control unit configured to, in response to the selected transmission method being time-division multiplexing (TDM), generate second data by including synchronization information for transmitting the first data using TDM in the first data; and a wavelength conversion unit configured to convert at least one of the first data and the second data into one or more wavelength optical signals using a predefined wavelength or a predefined group of wavelengths and transmit the wavelength optical signals to one or more radio stations.

Abstract: In accordance with the teachings of the present invention, a system and method for extending reach in a passive optical network (PON) is provided. In a particular embodiment, a method for extending reach in a PON includes transmitting traffic at a first wavelength from a transmitter at a first optical network unit (ONU) in a PON and transmitting traffic at a second wavelength from a transmitter at a second ONU in the PON. The method also includes receiving the traffic in the first wavelength at a first input port of a multiplexer at a distribution node in the PON and receiving the traffic in the second wavelength at a second input port of the multiplexer at the distribution node. The method further includes forwarding the traffic in the first wavelength and the traffic in the second wavelength to an optical line terminal (OLT) in the PON.

Abstract: A passive optical network system includes: a plurality of optical signal splitter receiving optical signals from a plurality of optical network units (ONUs) to provide a plurality of upstream optical signals having different wavelengths; a hybrid optical filter multiplexing the plurality of upstream optical signals in a wavelength division multiplexing (WDM) scheme; and an optical line terminal (OLT) receiving the multiplexed upstream optical signals in a time division multiplexing (TDM) scheme. Therefore, the network system can be easily expanded when the number of subscribers increases, and the optical loss can be minimized.

Abstract: A passive optical network system (PON) has a plurality of OLTs and ONUs with different transmission rates. OLTs with different transmission rates share information of priority frames and destinations, and determine timing for frame transmission to ONUs so that the signal from each of the OLTs does not collide when multiplied in a splitter. OLTs transmit the data to the ONU as a burst signal to prevent the signals with different rates from colliding. ONU acquires the information of the following burst frames. ONU receives only the signal addressed to the own ONU or with the transmission rate of own ONU, therefore errors in ONUs can be avoided. OLT receives only the signal with the transmission rate of own OLT from ONUs based on the transmission timing from the ONUs shared by the line terminators, errors in OLTs can be avoided.

Abstract: A communication apparatus time-division multiplexes a first signal transmitted at a first bit rate and a second signal transmitted at a second bit rate which is an integer multiple of the first bit rate, and sends out the first signal and the second signal to one line. The communication apparatus includes a pulse generating unit and a pulse superimposing unit. The pulse generating unit generates repetitive pulses having a width equal to a width of the first signal. The pulse superimposing unit superimposes the pulses generated by the pulse generating unit on the second signal.

Abstract: An interface module comprises a serial signal transceiver to be connected to an external transmission path and an interface processing unit connected to the transceiver. The interface processing unit comprises a serializer/deserializer circuit, an encoder/decoder, a protocol processing unit having at least two kinds of selectable protocol processing functions, and a communicate mode switch circuit for changing reference clock to be supplied to the serializer/deserializer circuit in conjunction with switching of the protocol processing function from one to another.

Abstract: A process for transmitting data on an optical fiber including multiplexing in wavelength signals coming from a plurality of monochrome transmitters, each of which has its own wavelength, and modulating information to be transmitted by a carrier realized per channel, wherein timing (clocking) of each transmitter is controlled by a common clock.

Abstract: Embodiments of the present invention provide a systems, devices, and methods in which a client signal is divided into a plurality of channels, mapped within transport frames, and combined into a WDM transport signal. These embodiments include intra-nodal redundancy that protects against failure events within the transport transmitter. In particular, redundancy is provided within a network transport transmitter such that redundant paths are available so that electrical channels may be routed around a malfunctioning component within the transmitter.

Abstract: An optical fiber communications apparatus comprises a housing provided with a motherboard and a plurality of modular cards , each of which is engageable with the motherboard via one of the card receptors. A optical card includes an optical transceiver for communication using a digital, optical communications signal over a single optical fiber link. Each modular card is provided with a plurality of circuit sub-assemblies, each circuit sub-assembly being configured for digital communication with a respective local audio, video or data electronic device via a respective connector using a respective electronic information-carrying signal. Each circuit sub-assembly is configured for communication of an audio, video or data information-carrying signal with the transceiver using the digital, optical communications signal.

Abstract: Expanding the coverage of a time-shared network comprising electronic edge nodes interconnected by bufferless fast-switching optical nodes is enabled by combining spatial switching with temporal switching. The output side of each edge node preferably connects to a large number of core switches through individual time-locked channels and the input side preferably connects to each of a small number of core switches through a channel band having a sufficiently large number of channels. Wavelength routers may be used to aggregate individually-routed channels into WDM links.

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: An optical communications network architecture and associated method which employs time and wavelength-interleaving for homing between nodes/satellites and hubs and for grooming, while employing wavelength-division-multiplexed wavelength circuits between hubs without requiring cross-connects or routers therebetween.

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: Provided are a wavelength conversion apparatus in a Time Division Multiplexing Passive Optical Network (TDM-PON) system based on a Wavelength Division Multiplexing (WDM) system, and an optical transmission method using the wavelength conversion apparatus. Each subscriber does not need to have its own wavelength but transmits an uplink signal using a wavelength band used in the TDM-PON system and routs optical network unit (ONU) uplink signals belonging to the same ONU to a wavelength conversion apparatus positioned in a subscriber area. The wavelength conversion apparatus converts the ONU uplink signals into wavelengths and uplinks the wavelengths of an optical line terminal (OLT) of a central office (CO) so as to enable a WDM transmission. Thus, a method of constituting a wavelength conversion apparatus and a remote node (RN) using the wavelength conversion apparatus can be suggested to realize a hybrid-PON system into which TDM-PON system and WDM systems are combined.

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: In accordance with the teachings of the present invention, a system and method for managing different transmission architectures in a passive optical network (PON) is provided. In a particular embodiment, a method for managing different transmission architectures in a PON includes transmitting traffic in an upstream or downstream direction in a first time-slot in a PON at each channel of a first set of one or more channels. The method also includes transmitting traffic in the same upstream or downstream direction in a second time-slot in the PON at each channel of a second set of one or more channels that provide greater bandwidth than the first set of one or more channels, wherein at least one channel of the first set at least partially overlaps at least one channel of the second set but is not identical to the at least one channel of the second set.

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

Abstract: The optical time division multiplexer generates a time-division-multiplexed optical signal by time-division-multiplexing optical signals of a plurality of channels, the carrier-wave phases of which are shifted with respect to one another. The circulator guides the multiplexed optical signals split by the optical splitter to the optical interference device and the superimposed light outputted from the optical interference device is guided to the optical intensity detector. The optical interference device extends the pulse width of the multiplexed optical signal to a width equal to or more than the bit interval and superimposes the extended light of an adjacent bit onto the extended light. The optical intensity detector detects the intensity of the superimposed light outputted by the optical interference device. The temperature regulator controls the temperature of the modulator so that the phase difference of the carrier waves constituting the optical signal trains is to be a half wavelength.

Abstract: A method and apparatus for allocating resources of a Visible Light Communication (VLC) terminal in a VLC system. The VLC terminal receives a beacon message from a base station, coordinates time synchronization with the base station, searches for an available wavelength channel, constructs available wavelength channel information, and transmits an initial access request using a basic time slot channel and a basic wavelength channel. The base station considers the available wavelength channel information and a current channel allocation condition, allocates an appropriate channel, and transmits channel allocation information to the VLC terminal. The VLC terminal and the base station communicate data with each other using an allocated time slot channel included in the channel allocation information and an allocated wavelength channel included in the channel allocation information.

Abstract: Systems and methods are presented herein to achieve data privacy in the optical realm such that electronic encryption bottlenecks are removed, potentially increasing data transmission speeds to the limit of fiber optic media. In this regard, privatizing an optical data transmission may include dynamically altering a temporal length of data bits in an optical data transmission or dynamically altering a temporal length of data frames in an optical data transmission. For example, in a two-dimensional OCDMA signal, the temporal length of data bits may be altered by changing the number of time chips on a per bit basis (e.g., using OCDMA signatures having different temporal lengths). In an optical data bit scrambling signal, the temporal length of data frames may be altered by changing the number of time slices on a per data frame basis.

Abstract: A bidirectional optical network, in which an incoming/downstream modulated optical signal(s) of a particular wavelength may carry content from a headend to a subscriber. An incoming/downstream unmodulated continuous wave optical signal(s) from the headend is time-shifted (i.e., time delayed with respect to just received incoming/downstream optical signal(s)), collected, modulated and sent back as return/upstream optical signal(s) from the subscriber to the headend. The return/upstream optical signal(s) may have the same wavelength or a slightly shifted wavelength relative to incoming/downstream optical signal(s). Wavelength, bandwidth, subscriber priority and service (content) provider may be fixed, dynamically, or statistically assigned. A modulated marker optical signal(s) is sent along with a modulated data optical signal simultaneously in a different plane. The modulated data optical signal(s) can therefore be securely delivered to a subscriber(s) according to the marker identification.

Abstract: The invention concerns a device for temporal subsampling of an OTDM optical signal at a predetermined subsampling frequency, comprising a generator (10) for generating clock pulses transmitted at the predetermined subsampling frequency and at a conversion wavelength ?H and a wavelength converter device (16) adapted to receive at its input the OTDM optical signal and the clock pulses in order to deliver at its output a subsampled OTDM optical signal at the conversion wavelength. The converter device comprises a linear optical amplifier (18) adapted to receive the OTDM optical signal and the clock pulses propagating in the opposite direction, the maximum linear power of the conversion being adjusted so that it can be less than the peak power of the OTDM optical signal, and a converter (20) of phase modulation into amplitude modulation.

Abstract: Embodiments of the present invention provide a method for transmitting low rate signals over an optical transport network, including: adapting the low rate signals into low rate optical channel data units of the same rate level with the low rate signals; asynchronously mapping each of the low rate optical channel data units into a low rate optical channel data tributary unit respectively, and generating justification overhead used for rate adaptation for each of the low rate optical channel data units; and forming a higher order optical channel data unit with at least one low rate optical channel data tributary unit and justification overhead corresponding to the low rate optical channel data tributary unit. The present invention enables the optical transport network to support mapping, multiplexing and highly efficient transmission of low rate signals.

Abstract: Disclosed is a distributed controlled passive optical network system and bandwidth control method thereof. The system comprises an optical line terminal (OLT), plural optical network units (ONUs) and a splitter with combiner. Each ONU has a first Tx/Rx for respectively transmitting and receiving data packets on an upstream data channel and a downstream data channel, and a second Tx/Rx for transmitting and receiving control signals/commands on a control channel. Upstream data of each ONU is carried by the upstream data channel and sent to the OLT through the splitter with combiner. Downstream data of the OLT is carried by the downstream data channel and sent to corresponding ONUs through the splitter with combiner. With the control signals/commands carried by the control channel, the required information of network status among the ONUs is provided.

Abstract: A method for negotiating speed between a Fiber Channel (FC) local client and a remote FC client across a DWDM network is provided. A transmission speed of the local FC client at a local ingress transport interface is detected. The data from the local FC client is forwarded along with the detected transmission speed to a remote egress transport interface. The remote egress interface forwards the data at the detected transmission speed to the remote FC client. The present invention eliminates complex speed negotiation state machines that would otherwise be required to make the DWDM transport behave like a virtual wire with respect to the FC ports and to allow the FC clients to negotiate the desired speed directly between themselves.

Abstract: The invention relates to a device and a method for converting WDM signals into an OTDM signal. The device comprises shifting means (102, 103, 104) adapted to introduce a time shift between the pulses of the WDM signals carried by the optical carriers, modulation means (112, 113, 114) adapted to modify the optical power of the WDM signals, an optical temporal multiplexer/demultiplexer (120), a birefringent propagation medium (130) into which the WDM signals are injected in such a manner as to achieve a soliton trapping phenomenon, and absorption means (140) adapted to introduce optical losses into the components of the OTDM signal. This device performs WDM/OTDM conversion at very high bit rates. It also performs OTDM/WDM conversion. It is intended to be installed in long-haul telecommunication networks.

Abstract: A bidirectional optical network, in which an incoming/downstream modulated optical signal(s) of a particular wavelength may carry content from a headend to a subscriber. An incoming/downstream unmodulated continuous wave optical signal(s) from the headend is time-shifted (i.e., time delayed with respect to just received incoming/downstream optical signal(s)), collected, modulated and sent back as return/upstream optical signal(s) from the subscriber to the headend. The return/upstream optical signal(s) may have the same wavelength or a slightly shifted wavelength relative to incoming/downstream optical signal(s). Wavelength, bandwidth, subscriber priority and service (content) provider may be fixed, dynamically, or statistically assigned. A modulated marker optical signal(s) is sent along with a modulated data optical signal simultaneously in a different plane. The modulated data optical signal(s) can therefore be securely delivered to a subscriber(s) according to the marker identification.

Abstract: A method and apparatus for transmitting signals from a plurality of input channels over a TDM optical network, where each of the input channels contains an optical data signal and an electrical control signal containing control information relating to the optical data signal. In accordance with the invention, respective optical receivers convert the optical data signals to respective electrical data signals, which a TDM data multiplexer time-multiplexes to generate a multiplexed data signal. A TDM control signal multiplexer time-multiplexes the electrical control signals to generate a multiplexed control signal that is combined with said multiplexed data signal to generate a composite electrical signal. An optical transmitter generates a composite optical signal from the composite electrical signal that is transmitted over the network, optionally after WDM multiplexing it with other composite optical signals.

Abstract: An optical pulse time spreading apparatus wherein an optical splitter divides an input optical pulse into first to U-th input optical pulses; first to U-th optical pulse time spreaders respectively have the first to U-th input optical pulses input thereto and output first to U-th chip pulse sequences each consisting of N chip pulses from a first to an N-th chip pulse arranged in order on a time axis into which the input optical pulse is time-spread; and an interval between adjacent ones of unit FBGs arranged in a p-th optical pulse time spreader and a Bragg reflection wavelength of the unit FBGs in the p-th optical pulse time spreader are set such that spectra of the first to U-th chip pulse sequences are different from each other.

Abstract: An optical access system capable of avoiding cutoffs or interruption in the periodically transmitted signals that occur during the ranging time is provided. A first method to avoid signal cutoffs is to stop periodic transmit signals at the transmitter during the ranging period, and transmit all the periodic transmit signals together when the ranging ends, and buffer the signals at the receiver to prepare for ranging. A second method is to fix definite periods ahead of time for performing ranging, then cluster the multiple periodic transmit signals together in sets at the transmitter and send them, and then disassemble those sets back into signals at the receiver. The transmitting and receiving is then controlled so that the transmit periods do not overlap with the ranging periods. In this way an optical access system is provided that can send and receive signals requiring periodic transmissions without interruption even during ranging operation.

Abstract: Provided is an apparatus for connecting a wavelength division multiplexing passive optical network (WDM-PON) to a time division multiplexing passive optical network (TDM-PON). In a hybrid, passive optical network which is a combination of the WDM-PON and the TDM-PON, the apparatus is formed at a subscriber side for matching the WDM-PPN and the TDM-PON. Accordingly, a passive remote mode can be implemented as a passive node not an active node. Therefore, the entire optical network can be efficiently operated. In addition, since the apparatus located on the subscriber side uses a wavelength-tunable light source, any dependency on the wavelength of a WDM-PON optical signal is removed.

Abstract: A communication system between head-ends and end-users is provided which expands bandwidth and reliability. A concentrator receives communication signals from a head-end and forwards the received communication signals to one or more fiber nodes and/or one or more mini-fiber nodes. The concentrator demultiplexes/splits received signals for the mini-fiber nodes and the fiber nodes and forwards demultiplexed/split signals respectively. The mini-fiber nodes may combine signals received from the head-end with loop-back signals used for local medium access control prior to forwarding the signals to the end-users. Upstream data are received by the mini-fiber nodes and/or fiber node and transmitted to the concentrator. The concentrator multiplexes/couples the mini-fiber node and the fiber node upstream signals and forwards multiplexed/coupled signals to the head-end.

Abstract: A method for transmitting signaling and control information for wavelength-division multiplex networks for optical, fiber-bound information transfer in digitized form, the signaling and control information being transmitted via the same optical channel, particularly with the same wavelength, as the useful information, but being encoded and decoded independently thereof, with the result that the control and signaling information can also be accessed independently of the useful information. The use of a time-division multiplex method allowing the different encoding of useful information and control information makes it possible considerably to reduce the technical complexity of passive optical network elements with regard to the routing of the signaling and control information. This method permits the simple, low-cost and transparent transmission of signaling and control information in the optical WDM network.