Communication between parties at a distance from one another.
Modern telecommunication systems
capable of transmitting telephone , fax , data, radio , or television signals
can transmit large volumes of information over long distances. Digital transmission is employed in order to achieve high reliability with minimal noise, or interference, and because it can transmit any signal type, digital or analog. For digital transmission, analog signals must be subjected to a process of analog-to-digital conversion; most television, radio, and voice communications are analog and must be digitized before transmission. Transmission may occur over cables, wireless radio relay systems, or via satellite links.