Part 1 of Essay
The Asynchronous Transfer Mode has been chosen as the standard system concept for integrated broadband communication networks by the ITU﷓T. The system is predicted to grow rapidly as soon as it becomes widely accepted by network operators and users. Why has communications evolved in history towards the ATM concept a ....

Part 2 of Essay
.... obvious way of keeping the constant connection necessary for voice traffic. The invention of the transistor and the concept of pulse code modulation (PCM) allowed digital communications to be developed in the late 1960's. The interconnection of computer systems over telecommunication networks soon became a requirement. Modems were used at first to generate analogue signals compatible with the PSTNs from the digital computer data to allow such interconnections. The already wide spread use of the PSTNs was an adv ....