r electromechanical machines, or paper Mutilated tape transmitters or receivers, that exist on the telex networks. The modern telex terminal has in addition the ability to communicate Number not accessible with the telex network word processing software, to enable the telex No circuits; trunks busy operator to prepare messages, edit, store and finally transmit the messages. This makes the telex terminal a very powerful communi- Number changed cation tool for business use. Called party ceased or spare line Indicate your called number 59.7 References * OCC Subscriber busy Agree Barton, R.W. (1968) Telex, Pitman. Renton, R. (1974) The international telex service, Pitman. Stop the transmission Paper Received I will call again Here ready for data transmission Please What is the charge? Please send test message You are in communication with a telex position Teleprinter Words Who are you? Finished I have finished, do you wish to transmit? Facsimile transmission LM Davis NEC (UK) Ltd Contents Introduction 60/3 Facsimile types 60/3 CCITT document facsimile equipment 60/5 G3 facsimile equipment 60/5 60.5 64kbit/s facsimile equipment 60/12 60.6 G3 networks, switches, gateways and PC fax 60/14 60.7 Facsimile futures 60/15 Bibliography 60/15 This page intentionally left blank Introduction 60/3 60.1 Introduction For document facsimile a different approach was necessary. Inter- operation had been the desired aim since 1968 when Group 1 was Facsimile, or fax, as it is known for short, is the technique for standardised. No one manufacturer expected to supply the whole transmitting a copy of an original page or document to a remote requirement and it was expected that business facsimile use, like the location. It is not taken in the original full sense of an exact copy or telephone, could be to new destinations as yet unknown. reproduction but is a scanned and reproduced copy. The received The growth in G3 machines after 1980 was due to the right combination of features: copy is usually desired as a crisp, clean, good contrast doc