Abstract: An optical WDM-TDM network includes a plurality of devices, each of the devices including at least one optical add/drop device adapted to drop optical signals of at least one channel of a plurality of received channels and pass through the remaining channels, at least one receiver, for receiving the at least one dropped channel from the at least one optical add/drop device, an aggregation device for assembling optical signals from the at least one receiver into original data formats, at least one transmitter for transmitting wavelength division multiplexed optical signals on the plurality of channels, a de-aggregation device for disassembling input data into blocks of data to be transmitted as optical signals by the at least one transmitter, and a controller for processing a global timing schedule.

Abstract: This invention provides a method and apparatus for spectral power monitoring by use of a polarization diversity scheme. In the present invention, a multi-wavelength optical signal is first decomposed into first and second polarization components, and the second polarization component is subsequently rotated by 90-degrees, prior to impinging onto a diffraction grating that provides a higher diffraction efficiency for the first polarization component. The diffraction grating separates the first and second polarization components by wavelength respectively into first and second sets of optical beams, impinging onto an array of optical power sensors. The inventive optical spectral power monitoring apparatus thus is able to minimize the insertion loss, while providing enhanced spectral resolution.

Abstract: A passive optical network employing wavelength dependent routing uses two-phase signalling between a network controller and terminals. In a first phase, terminals are informed of the wavelength channel allocated to them for a second signalling phase, groups of terminals being allocated to each channel. In the second signalling phase, control signals indicate to the terminal the wavelength and time slots allocated to the terminal in the following data transmission phase.

Abstract: A connectionless packet network and an optical WDM network are interconnected by one or more optical interface modules (gateways) that include both optical to electrical interfaces, as well as a connection management module, or control element, that is arranged to control the OADM's and the configuration of lasers and port assignments within the gateways, such that a route through the optical network to a desired endpoint is selected. The OADM's can be programmed, (i.e., locally or remotely controlled by the control element) such that the wavelengths that can be added or dropped by an OADM can be changed, thereby allowing routes to be established through the optical network, from an originating gateway to a destination gateway. In addition, the optical interface modules can include a plurality tunable lasers that can be controlled such that routes can be established through the optical network without requiring changes to the routing table that associates particular endpoints with particular ports.

Abstract: An all-optical time division multiplexing system, comprising:

Abstract: A method of providing a multi-wavelength light source includes the steps of modulating an optical pulse source so as to output optical pulses with a designated repetition frequency, time-division multiplexing the optical pulses output by the optical pulse source so as to output optical pulses with a repetition frequency which is an integral multiple of the designated repetition frequency, and demultiplexing wavelengths of the optical pulses with the repetition frequency which is the integral multiple of the designated repetition frequency so as to output the wavelengths as the multi-wavelength light source.

Abstract: A system for integrating broadcast and communication technologies is provided. The integration system performs a connection between an optical-network unit (ONU) and a user as well as a connection between an optical-line terminal (OLT) and the ONU using an optical line, and processes a broadcast signal on the basis of time division multiplexing (TDM) such that the quality of a broadcast service can be ensured. The OLT receives at least one digital-broadcast signal through an external broadcast network and at least one external data-communication signal, then electro-optically converts the received signals, combines the electro-optically converted signals to form an optical signal, and transmits the optical signal on the basis of optical wavelength-division multiplexing (WDM).

Abstract: An optical TDM multiplexing apparatus to multiplex a plurality of input signals in the optical stage in the time domain according to the invention comprise a plurality of signal light sources to generate optical signals each having a wavelength different from the others to carry each of the plurality of the input signals, a timing adjuster to adjust timings between the respective optical signals so that each optical signal output from the plurality of the signal light sources is disposed on a time slot different from the others in the time domain, an optical multiplexer to multiplex each optical signal output from the timing adjuster in the wavelength domain and a wavelength converter to convert each wavelength of the output light from the optical multiplexer into a predetermined wavelength.

Abstract: An optical-path-superposing-and-separating unit superposes optical paths of two inputted signal lights with each other, and then separate them. A non-linear waveguide is arranged in an area where the optical paths are superposed with each other. First and second optical waveguide are connected to the optical path superposing-and-separating unit. The second optical waveguide has a longer optical path than the first optical waveguide. A control light is introduced to the non-linear waveguide. An interference separator distributes the inputted two signal lights depending on a phase difference therebetween. Third and fourth optical waveguides connect the optical-path-superposing-and-separating unit to the interference separator.

Abstract: An multiplex transmission apparatus that realizes a receiving system using a phased array antenna with high efficiency and low cost is provided. A delay controller 102 gives a time delay to a local oscillation signal outputted from a signal source 101. First and second optical transmitters 1031 and 1032 each converts the local oscillation signal and the delayed local oscillation signal into optical signals. A first optical multiplexer 104 multiplexes the optical signals for transmission. An optical separator 106 separates the multiplexed optical signal. A first multiplexer 1071 multiplexes first and second main element signals, while a second multiplexer 1072 multiplexes first and second sub-element signals. First and second optical modulators 1081 and 1082 each modulates the optical signal with multiplexed electrical signal group. A second optical multiplexer 109 multiplexes the modulated optical signals for transmission.

Abstract: An optical superposition network that utilizes a time division multiplexing (TDM) protocol includes a first optical transmitter, a second optical transmitter and a receiver. The first optical transmitter transmits information in a tertiary mode during a time slot. The second optical transmitter transmits information in a tertiary mode during a different time slot. The information transmitted across the optical superposition network has an approximately constant average intensity such that the receiver can utilize a single decision threshold for the information received from the first and second optical transmitters.

Abstract: To delay optical signals precisely and continuously in a very small dynamic range, a device for applying a time-delay to optical signals includes a first phase modulator to receive an input optical signal carried by an original center wavelength and to apply a first stage of phase modulation to the carrier wave of the input signal to supply a first intermediate signal carried by a modified center wavelength, a delaying dispersive member having chromatic dispersion to receive the first intermediate signal and to supply a second intermediate signal, and a second phase modulator to receive the second intermediate signal and to apply a second stage of phase modulation to the carrier wave of the second intermediate signal to supply an output signal carried by the original center wavelength. Applications include optical telecommunication systems, in particular converting wavelength division multiplexed signals into time division multiplexed signals and regenerating wavelength division multiplexed signals.

Abstract: In a signal demultiplexing device formed by a probe light source, a wavelength converter, and a wavelength demultiplexer, the probe light source is formed by a plurality of sub-probe light sources configured to respectively generate the sub-probe lights with the prescribed different wavelengths for respective time-slots, a multiplexer configured to multiplex the sub-probe lights generated by the plurality of sub-probe light sources, and a phase different giving unit configured to give phase differences corresponding to time-slot positions to the sub-probe lights multiplexed by the multiplexer, and to sequentially output the sub-probe lights with the phase differences in correspondence to respective time-slots.

Abstract: High speed transport in a dense wavelength division multiplexed system is achieved by transmitting information supplied by multiple sources in a parallel format using a subset of the total number of optical channels in a wavelength division multiplexed signal as a parallel bus transmission group. In one illustrative embodiment, a selected number of optical channels, i.e., wavelength channels, in the wavelength division multiplexed signal are allocated to form a parallel bus transmission group, i.e., a wavelength bus. Information from one or more sources is supplied in a parallel format and then transmitted at the same transmission rate in each of the optical channels in the wavelength bus. When information from more than one source is to be transported, the information from each source is multiplexed into a parallel format.

Abstract: The present invention discloses a packet transmission device and a packet transmission system which can realize high-capacity communication. The transmission device transmits packets over a wavelength division multiplexing (WDM) link by mapping the packets into an optical path signal directly without any other medium such as an SDH path. The present invention also discloses a packet transmission device and a packet transmission system which can realize high-capacity communication over an SDH transmission link by mapping the packets directly into an SDH section payload without adding any VC path overhead in order to use the entire SDH section payload area.

Abstract: A system and control unit (26) for transmitting and distributing multiplexed audio data over an optical network (32). The control unit (26) comprises an audio sampler (36), a microcomputer (34), and an optical network interface (40). The audio sampler (36) samples a plurality of electrical signals (42A-D) from transducers (22A-D) and generates a plurality of raw audio data streams (54A-D) from the electrical signals (42A-D). The audio sampler (36) is capable of sampling the electrical signals (42A-D) at a fraction of a frame synchronization rate (Fs) of the optical network (32). The microcomputer (34) has an audio processor function (56) and a multiplexer function (58). The audio processor function (56) is capable of processing the raw audio data streams (54A-D) to generate a single processed audio data stream (62) at the frame synchronization rate (Fs) of the optical network (32). The multiplexer function (58) is capable of generating a multiplexed audio data stream (66) having a plurality of frames (70).

Abstract: A method and apparatus for preparing groups of low duty cycle WDM transmission channels such that each group can be demultiplexed either via conventional WDM (e.g., by optically filtering each channel and receiving that channel at its line rate) or via TDM (e.g., directing an entire group of WDM channels onto a signal higher speed detector, receiving them all and demultiplexing the channels in a temporal (electronic) domain).

Abstract: Optical networks using wavelength division multiplexing (WDM) techniques require innovative methods of maintaining network connectivity data and for identifying and isolating network faults. The present invention discloses such methods using a signal processor for installation at each node for retrieving upstream connectivity data from an out-of-band signal, updating the data and returning it to the out-of-band signal for use by downstream elements. A central network monitor periodically requests updates from each node of the connectivity data maintained by it in the form of messages transmitted along the out-of-band signal. When the various payload signals carried along the network are modulated with in-band signals carrying data which identifies the source and wavelength of the payload, this data can be combined with the updated connectivity data to identify network faults and raise alarms for transmission along the out-of-band signal to the central network monitor.

Abstract: An electro-optic interface structure for use in a multi-protocol OEO WDM network, the interface structure comprising a rate multiplying encoding unit for applying a rate multiplying line code to an electrical transmit data signal prior to conversion of the electrical transmit data signal into an optical WDM channel signal, and a rate dividing decoding unit for applying a corresponding rate dividing line code to an electrical receive data signal converted from a received optical WDM channel signal, wherein the encoding unit is arranged such that, in use, the same rate multiplying line code can be applied to electrical transmit data signals of different protocols, and wherein the decoding unit is arranged such that, in use, the application of the same corresponding rate dividing line code can create electrical signals of different protocols.

Abstract: The system and method are used for transparently transporting a multiplicity of data formats (TDM, frame, packet, cell, etc.) and bit rates in a deterministic manner over an optical telecommunications network facilitates purely photonic aggregation, separation and switching of granular, sub-wavelength capacity of bandwidths less than the line rate capacity. The sub-rate of the optical transport on a given optical frequency between network edge components uses time-slot based TDM channels that can be optically bursted across different wavelengths using wavelength hopping to allow all-optical switching of the channels between different signal paths in the optical switch nodes, on a time-slot-by-time slot basis using WDM to reduce the probability of blocked connections.

Abstract: Station apparatus used at a Local Serving Office (LSO) and at one or more stations reduces contention for communication access over time slots and/or wavelengths and/or fibers of an optical facility. The station apparatus enables Space-Wavelength-Time Division Multiple Access (SWT-DMA) communications using a combination of two or more different communication modes selected from a group including (1) a space division multiplexed access (SDMA) mode which selects a fiber(s) of the optical facility, (2) a wavelength division multiplexed access (WDMA) mode which selects a wavelength(s) on a fibers, and (3) a time division multiplexed access (TDMA) mode which selects time slot(s) of a wavelength. Communication mode selection may utilize (1) out-of-band signaling, (2) optical tag signaling, or (3) time marker signaling over a wavelength of one or more of the optical fibers.

Abstract: A method for assigning a predetermined wavelength between two different nodes in a wavelength division multiplexing ring communication network that has an N number of nodes and at least one pair of optical fibers sequentially connecting the N number of nodes is disclosed. A matrix is formed to represent optical-path configuration and wavelength assignment for an N−1 number of nodes. The matrix is extended by adding a column at any position of the matrix. Then X is assigned to the added column. An N/2 number of rows is added in the matrix. Tracking along each row toward the left, from the added column, a firstly encountered numeral is selected, and then the selected numeral is increased by one. Numerals 1, 2 . . . N/2 are assigned sequentially to locations corresponding to the added column in the added rows, and X is assigned to locations next to the numeral-assigned locations, where the number of X-assigned locations is equal to a hop-number corresponding to the assigned numeral.

Abstract: A lightwave network data communications system having such an architecture that routing operation within a lightwave network is simplified, and a high-speed transfer process is attained in a large-scale basic network utilizing a wavelength division multiplexing (WDM) technology which accommodates internet traffics from a plurality of subscriber networks.

Abstract: A method and apparatus for multiplexing/de-multiplexing optical signals is disclosed. The method and apparatus are applicable to a range of optical multiplexing techniques including, but not limited to: wavelength division multiplexing (WDM), dense wavelength division multiplexing (DWDM) and frequency division multiple accessing (FDMA). The disclosed devices do not require active components. The disclosed devices may be implemented with fiber or fiberless optical communication systems including telecommunications systems. The devices may be used on their own or as part of a larger system such as a multi-stage mux/demux, an optical switch, or router. Additionally, the devices are passively thermally stabilized with the result that their tuning is substantially invariant across a wide temperature range. The optical device includes a linear polarizer, at least one wave plate and a beam displacer/combiner.

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 and apparatus are disclosed for compensating for optical transmission delays in a synchronous mobile communication system. A Base Station Transceiver Subsystem (BTS) includes a Main Unit (MU) for processing a mobile communication signal and a plurality of Remote Units (RUs) connected to the MU by Synchronous Digital Hierarchy (SDH) transmission, for performing radio processing for communication with a Mobile Station (MS). The method comprises the steps of sequentially forming a loop on an optical transmission line to each of the RUs for optical transmission delay compensation test between the MU and each of the RUs; once a loop for the optical transmission delay compensation test is formed, transmitting a test SDH frame to a corresponding RU, and measuring a delay time until the test SDH frame is fed back; and transmitting data to the corresponding RU after compensating the transmission time by the measured delay time.

Abstract: The invention concerns a high speed optical transmitter, comprising at least one optical time division multiplexer, that is designed to generate a multiplexed signal with return-to-zero like pulse form out of at least two input signals, wherein further a conversion filter at the output of the optical transmitter is comprised and wherein the conversion filter shows filter means for generating an optical output signal with broadened pulses for reducing the use of spectral bandwidth, as well as an optical transmission system and a method therefore.