Browse Prior Art Database

Two Stage Transmission Arrangement for Local Networks

IP.com Disclosure Number: IPCOM000052628D
Original Publication Date: 1981-Jun-01
Included in the Prior Art Database: 2005-Feb-11
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Closs, F: AUTHOR [+2]

Abstract

In a local communication system comprising a number of terminal station and a common multiple-access transmission medium such as a bus, a two stage transmission arrangement is provided to simplify cabling requirements.

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Two Stage Transmission Arrangement for Local Networks

In a local communication system comprising a number of terminal station and a common multiple-access transmission medium such as a bus, a two stage transmission arrangement is provided to simplify cabling requirements.

Terminals are grouped in clusters, and for each cluster an attachment box is provided at the bus. Connections between terminals and the attachment box may be of varying lengths up to several hundred meters by twisted wire pairs or by coaxial cables.

The principle is shown in the drawing which illustrates one attachment box 1 together with its cluster of terminal stations (TS) 2, 3, and 4, and with a bus 5 common to all attachment boxes. Each terminal is connected by a coaxial cable or a twisted wire pair 6, 7, 8 to an input concentrator and matrix switch 9, and to a simple output driver in a set 10 of drivers (DR). A 2-to-4 wire converter may be provided in each of the lines 6, 7 and 8 for separating outgoing and incoming signals.

A control and selection unit 11 in the attachment box is interconnected between the input concentrator and matrix switch 9 and the bus 5. Unit 11 is also connected to the set 10 of output drivers. It comprises a receiver (R), a transmitter (T), a selector switch (SW), a microprocessor (MP), and a plurality of packet buffers (BU).

Operation is as follows: Outbound messages are distributed in broadcast mode to all terminals with the aid of output drivers 10 connected to bus receiver
R. Thus, no address translation or channe...