Telecommunications network

A telecommunications network is a system of end user devices, intermediate relays, and transmission media through which information is transmitted through energy in the electromagnetic spectrum. The information transmitted, as for the end users of the Public Switched Telephone Network (PSTN), need not be computers, although convergence of communications is pushing the concepts of telecommunication and computer network to be interchangeable.

As mentioned, the PSTN was the first widely deployed telecommunications network, if it is assumed the end users do not need a human intermediary to communicate through the network. Users of older telegraph networks commonly had to submit messages to human operators who had the specialized skills of transmitting and receiving telegraph messages. The public Internet is the most general telecommunications network, although if one allows restrictions of information network, the set of public and private networks using the Internet Protocol Suite is even larger.