Telecommunications is the classical message or communication technology, which mainly deals with voice and moving image transmission on the basis of analog electronics, starting from the telephone to the message satellite. It includes the transmission, sending and receiving of signs, signals, written images or sounds and messages of any kind by means of lines, radio or optical as well as other electromagnetic systems.
In order to be able to carry out telecommunications, transmission paths must be available and connections between subscribers must be established. This is done by means of telecommunications networks. Depending on the switching principle, a distinction is made in wide- area networks between networks with line switching and data packet switching, and between conventional networks and mobile networks.
In addition to networks, telecommunications is characterized by telecommunications services. A telecommunications service is defined as a specific service offered by a provider to carry out communications. A distinction is made between pure transmission and switching services, transport services or transmission services, telecommunication services in which the terminal equipment is taken into account, and value-added services.
In the consumer environment, there are the distribution services and the interactive services. The former group includes pay TV with pay-per-view, pay-per- channel, etc., and the latter includes video-on-demand, video games, tele-commerce and teleshopping, among others.