Page 53 - Intelligent Communication Systems

5

A VARIETY OF

TELECOMMUNICATION SYSTEMS

5.1 COMPUTER SHARING

Thirty years ago, computers were very expensive, making it difficult to buy one's
own computer. As a result, computer sharing arose, as a system for interconnect-
ing computers and terminals. Users were able to access a computer via a terminal
with time-sharing mode. This was a data communication system. The process flow
is shown in Figure 5.1
(1) Data is exchanged through path 1, between computer and terminal.
(2) A request for data processing is issued through path 2, from the
terminal to the computer.
(3) Data is exchanged between computers through telephone line 3 or
dedicated line 4. Data in a local computer is sent to the computer center
via networks. High-speed transmission of data is performed via a
dedicated line.

37