Communication has developed at a rapid pace and its development has been so fast that it is aptly termed as a revolution. Postal system is the oldest mode of communication and it has been used by man since the of dawn of modern civilization. It involves sending of letters and parcels to the addressee both within the country and abroad. Radio, television, fax and internet make communication more accessible to more people cutting across all barriers of time and space. Modern communication system, more than the transport system, has converted the world into a global village. The contemporary social and economic space is closely tied to modern communication system. Modern technology has enabled man to use satellites for communication purposes. Many advanced and developing countries are busy in developing satellite communication. United States of America and Russia are pioneers in the field of space research. The satellite communication system deployed since the early 1970s has rendered the unit cost and time of communication invariant with respect to distance. It costs the same to communicate over 500 km as it does over 5,000 km via satellite. India has also made many efforts to develop satellite communication. The first attempt was in the form of Aryabhatt launched on 19th April 1975. Bhaskar-I was sent into the space on 7th June, 1979. Rohini was launched on 18th July, 1980.
On 19th June, 1981 APPLE (Arian Passenger Payload Experiment) satellite was launched. Bhaskar-2 was sent into the space on 20th November, 1981. INSAT-1A was launched on 10th April, 1982 but in September the same year it stopped working. Consequently, INSAT-2B was sent to space on 30th August, 1983 through space shuttle, Challenger. INSAT-1B has made radio, television, and long distance communication very efficient and effective. Now forecasting about storm etc. is done more effectively. We daily see information about weather conditions on our TV screen. INSAT-1B has been replaced by INSAT-1D. INSAT-3B launched in March, 2000 made communication more effective. India’s first full-fledged meteorological satellite METSAT launched on 11th Sept. 2002 is giving valuable information about weather conditions.
Remote sensing is the act of acquiring information about a phenomenon which is not in intimate contact with the information gathering device. Remote sensing is done with the help of satellites and covers large areas. The best satellite images are provided by Landsat satellites of National Aeronautical and Space Administration (NASA) of the USA. A major step in remote sensing was taken by NASA in July 1972 when Earth Resources Technology Satellite (ERST-1) was launched. Its name was changed to LANDSAT-1 in 1975. The launch of Landsat, which is operated jointly by NASA and the US Geological Survey, took place in April 1999. The satellites have provided a wealth of information about the earth to scientists as well as to map makers.
With the removal of security restrictions by the governments of the USA and Russia on data gathered from reconnaissance satellites, private companies are increasingly using the information for non-military applications such as seeking potential energy sources, monitoring pollution, and analysing building sites, besides predicting weather, locating areas of deforestation and mineral deposits, identifying hundreds of other physical patterns and processes. As the technology develops, government, academia and business are continuing to d new applications for these images.
With the digitisation of information in the late twentieth century, telecommunication steadily merged with computers to form integrated networks through the internet. Today internet is the largest electronic network on the planet. Popular access systems of the internet allow any individual with a micro-computer and modem to plug into cyberspace, the world of electronic computerised spaces encompassed by the internet and related technologies such as the World Wide Web (WWW). Cyberspace may exist in an o, a sail-boat, or virtually anywhere.
As millions of new users log on to the internet each year, cyberspace has expanded rapidly in size and in use and importance, including e-mail and electronic commerce. Thus, cyberspace exists ‘everywhere’. In short, telecommunication revolution has expanded. This electronic network has progressed at an unprecedented speed in the human history. There were less than 50 million Internet users in 1995, about 400 million in 2000 A.D. and over one billion now. In the last five years there has been a shiamong global users from U.S.A. to the developing countries. The percentage share of U.S.A. has dropped from 66 in 1995 to only 25 in 2005. Now the majority of the world’s users are in U.S.A.,U.K., Germany, Japan, China and India.
As millions of new users log on to the internet each year, cyberspace has expanded rapidly in size and in use and importance, including e-mail and electronic commerce. Thus, cyberspace exists ‘everywhere’. In short, telecommunication revolution has expanded the human, social and economic space to a great extent.