Abstract: A method and system for information processing in a bidirectional information transmission system, particularly for transmitting information in accordance with a change in a transmission capacity of a transmission line. A system is provided which can change an information transmission rate in accordance with a room capacity of a transmission line. This information transmission system includes a plurality of information providers, a plurality of information receivers, an information storage and distribution unit connected to the information providers and receivers, and a plurality of information transmission lines for information transmission between the information providers and receivers and the information storage and distribution unit, wherein the information transmission rate of each information transmission line is changed.

Abstract: A method and system for information processing in a bidirectional information transmission system, particularly for transmitting information in accordance with a change in a transmission capacity of a transmission line. A system is provided which can change an information transmission rate in accordance with a room capacity of a transmission line. This information transmission system includes a plurality of information providers, a plurality of information receivers, an information storage and distribution unit connected to the information providers and receivers, and a plurality of information transmission lines for information transmission between the information providers and receivers and the information storage and distribution unit, wherein the information transmission rate of each information transmission line is changed.

Abstract: Data transmission and recovery, in either the optical or the electrical domain, can be accomplished with mBnB encoding with the violation of one or more of the n code pulses for multiplexing overhead signals, with a carried clock being indicated by periodic fixed position transitions, and with both extraction of the clock and demultiplexing of the overhead signals being accomplished with only logical processing and signal delay. For the above, transmission and processing in only the optical domain can be easily obtained as well as a circuitry that can be constructed cheaply and on a small scale, particularly by integration on a single substrate. The logical processing involves logical combinations of two or more of the received encoded signal, a delay of the received encoded signal, an output of a previous logical combination, and a delayed output of a previous combination, an extracted clock, and a frequency division or a frequency multiplication of an extracted clock.

Abstract: Installation paths for routing cables or wire in a distribution service area emanate from a center point and extend outwardly to several distribution areas. Each distribution area has a plurality of subscriber stations with subscriber line extending between a distribution point for the distribution area and each of the stations. The distribution points for each of the distribution areas are connected to the center point of the distribution service areas by feeder lines. The installation paths that extend through the distribution areas adjacent the center point have both feeder lines and subscriber lines. Thus, the total length of the installation path network is shortened by the sharing of the installation paths. Further, the distribution points for each of the distribution areas is selected to be the one closest to the center point for the distribution system.

Abstract: A transmission system which includes a plurality of reproduction nodes connected to each other in a cascade connection via a communication line. Each node includes a timing extraction circuit for extracting a timing signal from a signal received via the communication line, a discriminating circuit for converting the received signal into a digital signal according to the timing signal, and a processing circuit for processing, based on the timing signal, the digital signal outputted from the discriminating circuit and outputting the processed digital signal to the communication line. The timing extraction circuit includes a signal delay unit for supplying the timing signal with a signal delay time greater than a delay time occurring in the processing circuit.

Abstract: The invention relates to an optical subscriber network transmission system and, in particular, means for smoothly enlarging the transmission capacity in such system. The invention shortens the time of service interruption during changeover of transmission line capacities by use of a spare optical transmission line. Installation of a low cost spare optical fiber line permits testing of transmission lines without service interruption. Successive changeovers are performed using the auxiliary fiber keeping service interruption to a minimum.

Abstract: The present invention relates to an optical subscriber network transmission system which comprises a first optical transmission line whiich transmits information from a center to a subscriber, a second optical transmission line which transmits information from the subscriber to the center, and an auxiliary optical transmission line which is laid between the center and the subscriber.

Abstract: An optical receiving method utilizing polarization diversity is disclosed in which first and second reference lightwaves having different frequencies and having polarization planes substantially perpendicular to each other, are combined with a signal lightwave to form a combined lightwave. The combined lightwave is subjected to heterodyne detection to obtain a detection signal and the detection signal is separated into first and second intermediate-frequency signals having different carrier frequencies. The first and second intermediate-frequency signals are converted into first and second baseband signals, respectively, and the first and second baseband signals are added to obtain an output signal.

Abstract: Disclosed is an optical switching apparatus comprising means for converting serial optical or electrical signals into parallel signals in a time division mode, first and second time division switch groups and a space division switch group for cross connecting the signal of the optical or electrical signals, and means for generating the edited optical or electrical signals as serial signals again.

Abstract: An optical subscriber network transmission system comprises a first optical transmission line transmitting information from center to a subscriber and a second optical transmission line transmitting information from to the subscriber to the center. A plurality of auxiliary optical transmission lines are disposed between the center and the subscriber.

Abstract: An optical receiver includes a squeezer for changing the quantum state of a signal lightwave to a squeezed state, a slave laser put in an injection locking state by the signal lightwave outputted from the squeezer, and an optical homodyne detector for carrying out optical homodyne detection for the signal lightwave outputted from the slave laser.

Abstract: A communication network system includes a communication line, a plurality of communication stations each having a node coupled to the communication line and a network controller coupled to the stations for controlling routing for communication messages between nodes. In one embodiment, the messages are sent from plural terminals connected with each node along with communication performance prerequisites. The communication performance prerequisites for a communication message are discriminated in the node which receives the message. Traffic in various routes between the nodes is continually measured in the communication stations and the measuring results are stored in a database storage unit.

Abstract: The invention provides a communication method and system for use in a network for digital data exchange/transfer through a circuit switched network. According to the method and system, a call is given the attribute of an intermittent transfer mode, and a device for identifying attributes is provided on network controls in connection paths so that the network control establishes a path only in response to a data transfer request from identified call and releases the path when the call is held on standby for data transfer.

Abstract: A digital signal multiplexing apparatus comprising variable multiplexers each of which can alter a multiplexed channel format every call in compliance with a subscriber's request, a fixed multiplexer which has a multiplexing capacity integral times as large as the total multiplexing capacity of the variable multiplexers and the multiplexed channel format of which is fixed, and fixed multiplexed signal demultiplexers each of which fixedly demultiplexes signals in a capacity integral times as large as that of each of the variable multiplexers into signals in a capacity equal to the total capacity of the variable multiplexers, wherein the outputs of the fixed multiplexed signal demultiplexers are distributed to the variable multiplexers through a distributing switch network, and the outputs of the variable multiplexers are multiplexed by the fixed multiplexer.

Abstract: A high speed digital signal multiplexing method and apparatus are provided wherein a plurality of first higher bit rate transmission frames are provided, each first higher bit rate transmission frame being multiplexed therein with lower bit rate signals in an n-byte (n is an integer) interleave manner, and the lower bit rate signals are selectively derived from the plurality of first higher bit rate transmission frames and multiplexed into a second higher bit rate transmission frame. When a phase conflict is detected among the derived lower bit rate signals, all the data columns of at least one of the derived lower bit rate signals are given a predetermined delay by means of a shift register, and the derived signals are multiplexed into the second higher bit rate transmission frame. When a first higher bit rate transmission frame asynchronous with the system frame is detected, a pointer is derived which pointer represents a predetermined information unit within the derived lower bit rate signal.

Abstract: A digital signal transmission system which converts first digital signals having a given bit rate into second digital signals having a predetermined bit rate to transmit them. The first digital signals are written into a buffer memory at a bit rate of the first digital signals, and the written signals are read from the first buffer memory at a bit rate of said second digital signals. The reading of the digital signals is carried out with a clock signal which consists of synchronous portions that read the written signals at any time and asynchronous portions that read the written signals depending upon the condition of the written signals. The second digital signals are sent after adding a data signal to the asynchronous portions of the digital signals.

Abstract: A high-speed light emitting diode driver circuit for optical communication systems, in which an impedance circuit is provided between the collector and emitter of a drive transistor, and another impedance circuit is provided on the emitter side. The light emitting diode is connected to the collector side of the drive transistor. The light emitting diode is driven by an input pulse signal applied to the base of the drive transistor.

Abstract: A method of searching fault locations which is employed in a transmission system comprising a transmitting terminal having a transmitter for transmitting a digital signal; a receiving terminal having a receiver for receiving the digital signal; a plurality of repeaters which are placed between the transmitting and receiving terminals, and each of which receives and amplifies the digital signal from a preceding repeater section and deliver it to a subsequent repeater section; and a plurality of transmission lines for connecting the transmitter with the first repeater, the repeaters with each other and the final repeater with each other and the final repeater with the receiver, respectively.

Abstract: In order to enhance the general purposeness of a time domain multiplexer for digital channel signals of unequal bit rates, the time domain multiplexer is constructed of a plurality of channel units which provide information signals and bit rate signals of input channel signals, a plurality of logic circuits which multiplex the information signals from the channel units, and a control circuit which selects and combines the logic circuits in accordance with the bit rate signal so as to construct a multiplexer conforming with the bit rate.

Abstract: A two-level alternate mark inversion signal transmission system wherein binary pulses of "1" and "0" levels are converted into a pulse signal in which one coded information value has its polarity inverted at a period T and the other has its polarity reversed at a period T/2, and the converted signal is transmitted. In order to facilitate an automatic gain control operation and the proper and reliable extraction of a timing signal on the receiving side of the system even when the zero binary pulses have successively arisen in the signal processed on the transmitting side, the alternate mark inversion signal is converted into a specified code (zero substitution) signal when the zero binary pulses have succeeded one another for a predetermined number of times, while on the receiving side, a received signal is subjected to duobinary shaping, whereupon the zero substitution part is detected for removal by utilizing the rules of the zero substitution process and the alternate mark inversion signal.