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.
The satellite networks of modern age embrace, to a large extent, Very Small Aperture Terminals (VSATs) to cater to the traffic and application requirements of varied users. The VSAT networks are designed to support all kinds of applications supporting video, voice and data, with a wide range of data rates from few kilobits per second (kbps) to 8 megabits per seconds (mbps). A VSAT network comprises of a central hub and hundreds of terminals, which are further interfaced to computers and other peripheral devices. The hub acts as a gateway with interface to external connectivity and several application servers. Rapid technological advancements and reduction in the cost of user equipment are increasing the popularity of VSAT network. A VSAT network works out to be a cheaper option while establishing a network to cover a wide geographical area, state wide or nationwide. VSAT networks operate in C, Extended C and Ku-bands.
About 1400 Satellite Earth Stations of different size are operating in satellite network of BSNL, Government users, Closed user group, commercial users and broadcasters and are being utilised for telecommunications / broadcasting applications.Telecom services are being provided by BSNL to remote and inland through satellite media in C-band and Ku-band from main earth stations as backhaul point to point connections. BSNL is also providing GSM connectivity, ATM/Banking connectivity through around 20,000 IPSTAR VSATs as well as one by two voice channel connectivity to remote areas through around 6,000 Digital Satellite Phone Terminal (DSPTs).
Captive satellite based networks for NTPC, GAIL, Oil and Natural Gas Corporation Ltd., National Fertilizer Ltd., Coal India Ltd., ERNET, Karnataka Power Transmission Corporation Ltd., IOCL, BPCL, Jai Prakash Industries Ltd., Indian Railway Project Management Unit, ICAR, POLNET and Infotel Satcom are operational in INSAT system. The networks of Bombay Stock Exchange in Extended C Band are operational on INSAT system. A number of other captive government networks like Indian Coast Guard, Ministry of Defence, Cabinet Secretariat, DRDO, etc., are also working with INSAT satellites.