Abstract: The invention relates to a time division switching system which may transmit both voice and data signals. The data signals may be transmitted at a much higher speed than the voice signals, such as twice the speed, for example. To do this, the data signals are split into two time slots which are separately transmitted. Since the two time frames are so closely related, they must be transmitted within the same frame as a unit. This is done by a combination of two memory switches and control means for transmitting multi-element information. The two memory switches are used in an alternating sequence.

Abstract: A synchyronous receiver with direct mixing comprising a phase detector and an amplitude demodulator is provided with a square-law envelope detector and means for making the envelope signal audible or visible for tuning purposes.

Abstract: A mobile radio facility for installation in a motor vehicle which already includes a junction cable extending from a location in the trunk to a location in the passenger compartment, terminating at each end in a plug connector. The facility includes a radio unit which can be installed in the trunk and plug connected to the vehicular cable, and one or more peripheral units in the passenger compartment such as a micro-telephone, control panel and/or portable telephone. Each peripheral unit has at least a pair of identical plug-in terminals providing identical connections thereto. The facility also includes a plurality of additional junction cables, one of which is plug-connected at one end to the vehicular cable and at the other end to a plug-in terminal of one of the peripheral units. Each of the remaining cables is plug-connected at each end to a plug-in terminal of different peripheral units so as to establish a sequential order of interconnection of all such units to the vehicular cable.

Abstract: An emission device includes a first electro optical converter for converting electrical energy from a supply source into optical energy. A second electrical converter is provided to convert the electrical energy into digital information which is converted into digital optical information by a second electro optical converter. A reception device includes two optoelectrical converters connected to the electro optical converters by an optical path, and an electrical power accumulator capable of storing said electric power delivered by said optoelectric converter. The power accumulator is capable of supplying the reception device with electric power.

Abstract: In a receiver for receiving and decoding a baseband multilevel signal into a digital data signal, and A/D converter produces in addition to the decoded data bits a "soft" bit, which inherently indicates the error polarity of the baseband signal. The soft bits are binary added to the most significant data bits to produce a sum bit. The sum bits are integrated, and the integral is used in a feedback loop to control the baseband signal amplitiude.

Abstract: A method of selecting at least one code word from a set of second data having at least one data group representing a set of first data having at least one data group including the steps of determining for one of the set of second data, all those data groups in the set of first data covered by the one of the set of second data, eliminating the covered data group from the set of first data, selecting as one of the at least one code word the one of the set of second data which covers the maximum number of data groups in the set of first data, and repeating the above steps until a given criteria is satisfied.

Abstract: A three level network microprocessor based nodal architecture for a fiber optic local area network communication system is disclosed in which the processing responsibility for establishing a voice, video or data communication link between an initiating I/O device and a recipient I/O device and for subsequent two way data exchange between the initiating and recipient devices are shared between three levels of digital processing capability in such manner as to demand the least amount of time from the highest, most intelligent processing level common to all devices thereby making more efficient use of its processing capability as an overall supervisory processor. Each I/O device whether it be a digital terminal, computer or telephone set interfaces with a nodal system through a middle level of processor.

Abstract: Line trunk groups coupled to a double central switching matrix by way of two PCM lines and including sub-switching matrix and group control units are allocated to one another in pairs. Prepared for stand-by service switch-over by the central switching matrix and the processor are subscriber and trunk lines within each line trunk group pair, which are connected to the sub-switching matrix of a first line trunk group and are switchable to that of a second line trunk group, such that their group control unit also assumes the control functions. The processor going into service with the stand-by switch-over is connected with the group control units of all first line trunk groups via its central switching matrix, while all switching service continues with those of all second line trunk groups. Connection data of all existing connections are stored in all group control units.

Abstract: In a system which includes a data transmitting device, a repeater, and a data receiving device, the repeater accumulating input data in packets from the transmitting device and retransmitting it to the receiving device, a memory structure for the data which includes a data buffer a receive queue having a plurality entries, each entry capable of storing the starting address of a packet in the data buffer in order of receipt, and a transmit queue for storing the starting addresses of packets for transmitting to said receiving device is provided in the repeater. In operation, only addresses are transferred from receive queue to transmit queue with the data remaining in the buffer. Preferably the buffer and queues are circular.

Abstract: An oxide cathode comprising a base 1 which consists substantially of titanium and a heater element 5 coated with aluminium oxide 6 to heat the base 1, which bears a porous alkaline earth metal oxide emissive layer 4. When the surface of the titanium base 1 which is opposed to the heater element 5 bears a metal layer 7 consisting at least of one of the metals Pt, Mo, Ta and W, a solution is obtained to the problem occurring in titanium cathodes in that titanium in contact with aluminium oxide is not chemically stable. The metal layer preferably consisits of pure tungsten and is formed by chemical vapour desposition (CVD). The metal layer is preferably from 1 to 10 .mu.m thick.

Abstract: A converter to convert audio signal associated with commercial television transmissions for input into conventional AM/FM automobile receivers so as to facilitate listening to the audio portions of telecasts on conventional radios.

Abstract: Each entering and outgoing hybrid time multiplexed signal is made up of frames with fixed length time intervals each carrying a block of words that form either a packet or a channel, except the first time interval of each frame which contains a frame synchronization block. The multiplexed signal is applied to a packet time switch using a paragonal conversion, as in the switch described in European patent document EP No. 113 639. The switch is comprised of input and output rotation matrices, a packet buffer memory, and a channel buffer memory, a packet/channel discrimination memory, a packet label translation memory, a set of memory files for the addresses of the packets in the packet buffer memory, a read control memory for reading in the channel buffer memory, a time base and a control unit capable of changing the contents of the translation memory of the discrimination memory and of the read control memory in terms of the traffic to carry.

Abstract: A digitally trunked radio repeater system provides substantial improvements in timeliness of channel acquisition and channel drop, and in reliability of critical control signalling. The system uses a much higher digital signalling rate than is typically found in prior art systems, and uses a control channel to convey digital channel request and assignment messages between the central site and mobile transceivers. The mobile radio transceivers transmit channel requests on the control channel (if no response is received, the mobile retries during a retry time window which increases in duration in dependence on the number of retries). The mobile transceiver switches to a working channel in response to an assignment message received on the control channel. Subaudible digital signals transmitted on the control channel and on active working channels allow late entry, shifting to higher priority calls, and other advanced functions.

Abstract: A circuit arrangement for serial data transmission between a plurality of subscriber stations via a data bus with transmitters that are high-impedance in the passive condition and low-impedance in the active condition is provided with a mutual control of the subscriber stations which occurs via the data bus without the assistance of additional control lines. This is achieved in that the leads of the data bus are each connected to a voltage source at at least one location via a resistor and in that at least one evaluation device for evaluating the voltages carried by the two leads is provided, the evaluation device outputting a busy signal given voltages of different magnitude at the leads of the data bus and outputting a free signal given identical voltages at the leads of the data bus. The circuit arrangement is particularly suitable for utilization in remote control devices.

Abstract: Disclosed is a structure of a housing for a paging receiver of the type including a storage device and a write terminal for a writing code in the storage device. A battery case is disposed in a part of the housing and provided with a window that communicates with the interior of the housing. The write terminal electrically connected to the storage device faces the window so that a connector of a writing apparatus may be inserted into the housing through the window to be connected to the write terminal. The write terminal is not exposed to the outside of the housing, thereby to enhance the resistivity to static electricity and hermetic sealing against dust, water and other impurities and therefore to achieve reliable operation.

Abstract: A switching network is constituted by a plurality of time switches which are arranged in a matrix and at cross points between a plurality of input buses and a plurality of output buses, on which frame synchronization signals are multiplexed. Each time switch includes a data memory in which data on the input bus is written in synchronism with the frame synchronization signal included in the input bus, and from which data is read out under the address control of a control memory in synchronization with the frame synchronization signal included in the output bus.

Abstract: An optical interface which is adapted for use in a local area network is provided. The optical interface comprises an optical transmitter section and an optical receiver section. The optical transmitter section receives data in a non-return to zero inverted (NRZI) format from a LAN controller which the optical interface is part of a remote node. The optical transmitter section converts the non-return to zero inverted data to an alternate mark insertion (AMI) format. An LED driver circuit smooths out and extends the alternate mark insertion data and uses it to drive an LED. The LED driver alternately drives the LED from a fifty percent reference output level to zero percent output and one hundred percent output corresponding to alternate positive-going and negative-going transition of the data. The optical receiver section has a light sensitive detector and preamplifier which receives optical signals encoded with digital data and generates corresponding electrical signals.

Abstract: A pair of signal paths 3-1 and 3-2 are connected in parallel to an input 2, each composed of the respective mixing stages 4-1, 4-2, low-pass filters 5-1, 5-2 and mixing stages 6-1, 6-2. The mixing stages 4-1, 4-2 are connected to the oscillator 8 in a phase-quadrature relationship. The mixing stages 6-1, 6-2 are connected to the oscillator 9 in a phase-quadrature relationship and are both connected to a superposition circuit 7 having an output 10. For obviating the drawback of unbalance in the signal processing in the signal paths 3-1, 3-2, the receiver 1 includes a control signal arrangement 11, which is constituted by the respective further mixing stages 14, 25, low-pass filters 47, 48, and mixing stages 17, 29 for producing at the control signal outputs 22, 34 an amplitude and a phase control signal for correcting this unbalance.

Abstract: An automatic frequency sweeping method for controlling frequency synthesizing type autotuners for broadcasting receivers comprises a first intermediate frequency counting method in which the intermediate frequency is counted for a relatively short first time and the presence or absence of the received signal is judged in a first range having a relatively wide intermediate frequency width and a second intermediate frequency counting method in which the intermediate frequency is counted for a second time longer than the first time and the presence or absence of the received signal is judged in a second range having a intermediate frequency width narrower than that of the first range. Thus, a high speed frequency sweeping is ordinarily executed by using the first intermediate frequency counting method, and when the presence of the received signal is judged in the first intermediate frequency counting method, a more precise judgement is made in accordance with the second intermediate frequency counting method.

Abstract: There is provided by this invention an optical heterodyning device comprised of a semiconductor heterostructure having a forward biased electrode connected thereto for optically mixing an input signal frequency with a local oscillating frequency in the separate confined laser cavity and a reverse biase electrode connected thereto for detecting the intermediate frequency produced. The local oscillator provides preamplification in the laser cavity and can be effectively phase locked to the input signal frequency.