ATM networks

After a long period of relative stability, during which telecommunication services took two essential forms: the telephone service and the telegraph service, more commonly known as telex, and where the main technical innovations remained confined to well-characterized professions - switching and transmission - several major developments marked the 70s and 80s.

The first evolution is underpinned by the fantastic technological revolution that began in the early 1960s under the impetus of information technology: the development of increasingly complex logic components led to both a change in information processing techniques in the world of computers and, by extension, in that of telecommunication network control units, and a change in information transport techniques with the irruption of digital modulation. This was the era of electronic switching and digital telephony, two developments that, after a few ups and downs, went hand in hand.

The second evolution is also a consequence of the development of information technology, this time as a client of telecommunication networks. The emergence of the "information age" gave rise to a need to communicate this information via telecommunications networks. This was the era of data transmission, both in the private sector, with the proliferation of local area networks (LANs), and in the public sector, with the deployment of X.25 and other telecoms networks. This first breach in the stability of telecoms services led, towards the end of the 1970s, to the definition and implementation of ISDN (Integrated Services Digital Network).

In telecommunication networks, the two worlds of computing and communications were brought together. However, while data transmission steadily increased its demands in terms of throughput, a third major player remained partially on the sidelines until the early 1980s: the audiovisual and broadcasting world. Long resistant to digital techniques, long isolated in telecommunication terms due to the specific nature of broadcasting services, this sector was successively attacked by the digital sound of compact discs, non-exclusive CATV (cable television) cable networks ( — ), the French cable plan ( — ) and the irruption of digital images and multimedia in the world of computing... and games.

The concept of a broadband network was born at the meeting point of the three worlds of computing, audiovisual and telecommunications. Very early on, the term B-ISDN (Broadband Integrated Services Digital Network) was coined, without it being clear at the outset whether it would really be an entirely digital network, or whether it would be truly integrated services, or even which services we were talking about... It was in this ambiguous and unpredictable context that...