Showing papers on "Network switch published in 1985"

L-Expressnet: The Communication Subnetwork for the C-NET Project

Abstract: L-Expressnet is the communication suxbnetwork for the CNET local area network project of the CNR, Italy. Based on a single bus topology, it utilizes a simple and efficient virtual-token access protocol which provides ordered and collision-free transmission. The paper discusses the needs which led to L-Expressnet, describes the protocol, proves its correct operation, and compares its throughput-delay performance with those of other typical bus Protocols. A major advantage of L-Expressnet is that its implementation may be based on Ethernet standard transceivers and network interfaces.

Channel switch control system

Abstract: PURPOSE:To improve the efficiency of conversion by using a control circuit which makes and brakes a channel switch along the flow of the PCM signal in the channel at a designated time point. CONSTITUTION:A time division switch network of a PCM channel comprises the 1st stage channel switch 1 and the 2nd stage channel switch 2. For control of the switch network, the 1st stage channel control circuit 5 which control the switch 1 after receiving the 1st stage channel control instruction input given from a time point generating circuit 3, a time delay circuit 4 and a terminal 9 as well as the output of the circuit 3 is provided together with the 2nd stage channel control circuit 6 which receives the 2nd stage channel control instruction input given from a terminal 10 and the output of the circuit 4 and controls the switch 2. The circuit 4 functions to give a time difference to the open/close actions of switches 1 and 2 for the PCM signal to pass through the channel. Thus the efficiency of conversion is improved.

The Harris 20-20 Integrated Network Switch

Abstract: This paper describes the system architecture of the Harris 20-20, an integrated voice/data network switch. Both hardware and software aspects of the system are presented. The hardware buses and all major assemblies are identified and described. The architecture is innovative in that the system accommodates both North American and European standard multiplex equipment. The software design permits the subsystems to all run on a single microprocessor or to be distributed over multiple processors with no change to the application-level software.

Distributed Microprocessors Control Architecture for Versatile Business Communications

Abstract: This paper describes the NEAX®2400 Information Management System (IMS), which is no longer a conventional telephone switching system, but is instead a switching hub for various office automation equipment. The NEAX2400 IMS not only provides various circuit-switching functions such as conventional voice communication (telephone) switching, low-speed and high-speed data switching, but also provides stored and forward capabilities for voice (voice mail) and data (text mail, facsimile mail, etc.). This paper especially emphasizes the basic EPBX features and functions of the NEAX2400 IMS. The standard 64 kbit/s PCM technique is used for digitalization of voice signals, and switched through a nonblocking architecture time-division digital network. All digital data signals are transmitted through the same time-division digital network at the 64 kbit/s rate intermixed with digital voice signals. The controls of the switching functions, station service features, and maintenance service are performed by functionally divided distributed microprocessers. The most outstanding attribute of the NEAX2400 IMS is the unique building-block architecture of the equipment configuration. Modules are stacked above the basic module as the number of line and trunk ports, or additional stored and forward features are required. Up to four additional modules can be stacked up as a single module group. This unique arrangement permits the NEAX2400 IMS to be very flexible in its system applications and expandability. Practically, the NEAX2400 IMS will economically service as few as 184 ports (mixture of voice/data, line/trunk) and can be continuously expanded to as many as 23 184 ports.

Optical switch for optical network

Abstract: PURPOSE:To increase a switch speed by putting an optical switch in repeat operation with a control voltage when the operation of each station is normal, and lowering the control voltage to zero and by-passing all outputs from leading stations during abnormal operation. CONSTITUTION:The transmission part 1012 of a station 101 outputs a signal from an LED to an optical switch 91. A control part 1013 applies the control voltage to the electrode of the optical switch 91. When respective stations are in normal operation, optical switches 91-93 lead all light beams from leading stations to receivers 1013 with the control voltage from a control part 1013 and also lead all light beams from transmission parts 1012 to following stations. When some station operates abnormally, the voltage from its control part 1013 drops to 0V and light from the leading station is all guided to the following station. Consequently, even if one station is shut down, all signals by-pass the station with high efficiency, so station intervals are increased. Further, optical network switches which has a fast switch speed and small insertion loss are realized.

Three-way data switch for use in a control system for an automated work station

Abstract: A THREE-WAY DATA SWITCH FOR USE IN A CONTROL SYSTEM FOR AN AUTOMATED WORK STATION A control system for an automated work station comprises a data switching device having a first bidirectional port connected to a control computer, a second bidirectional port for connection to the controller of the work station and a third bidirectional port connected to an operator terminal The switching device comprises logical circuitry responsive to signals from a manually operable mode selector circuit for interconnecting any selected pair of the ports Other switch means on the device allow the monitoring at the operator terminal of the data transmitted between the computer and the work station controller

Network and packet switching method with possibility of internal transmission of packets in a floor

Abstract: RESPECT THE INVENTION PACKET SWITCHING NETWORKS. A NETWORK SWITCH INCLUDES ALL LEVELS WITH MANY PAIRS OF KNOTS SWITCHING 202-0, 202-2, ... WITH LINK 220-0 INTERNAL BETWEEN EACH PAIR OF KNOTS. ON THE BASIS OF THE INFORMATION CONTAINED IN EACH OF DESTINATION PACKAGE TOURS CONTROL FORWARD EVERY PACKAGE TO ITS DESTINATION USING ANY LINK 203-0 INTER-FLOOR OR INTERNAL LINK BETWEEN KNOTS 220-0 ACCORDING TO AVAILABILITY BONDS AND THE APPOINTMENT MADE BY A CIRCUIT USING A GENERATOR RANDOM NUMBER. APPLICATION TO DIGITAL TELECOMMUNICATIONS NETWORKS.

Signal generation device

Abstract: PURPOSE:To shift optionally a signal in phase by adding an adder for shifting, shift mode selecting circuit, and storage command generating circuit to the signal generating device. CONSTITUTION:When a shift command signal is not supplied to an input terminal 26, a data switch 21 supplies the contents of the adder to an integrating register 14, whose contents are supplied as an address signal to a waveform storage device 15 to read stored data out of a corresponding address, so that the data is outputted through a DA converter 16 and a low-pass filter 17. When the shift command signal is supplied to the input terminal 26, the storage command generating circuit 24 supplies the signal of the adder 25 for adding to the integrating register 14 through a data switch 21. When a shift in phase is made, an H signal is supplied to an input terminal 25. The adder 23 for shifting adds the output value of the integrating register 14 when the shift signal is supplied to the relative value set in a phase setting register 12 and supplies the sum to the data switch 21.