TELECOMMUNICATION: Telecommunication is the transmission of signs, signals, messages, words, writings, images and sounds or intelligence of any nature by wire, radio, optical or other electromagnetic systems. Telecommunication occurs when the exchange of information between communication participants includes the use of technology. It is transmitted either electrically over physical media, such as cables, or via electromagnetic radiation. INSAT satellites have been traditionally supporting telecommunication applications for providing voice and data communications. Satellite links are the primary means of connectivity to remote and far-flung regions of the country and they are the backup links for large number of terrestrial connectivity in the mainland. HISTORY OF TELECOMMUNICATION: Smoke signal Carrier pegion Morse code Wireless radio Telephone Fax Mobile telephone Internet E-mail Handheld devices