INSAT 4A and INSAT 4B are dedicated to telecommunications, with 12 Ku-band and 12 C-band transponders each. Their coverage zone is the Indian sub-continent.

Designed, built, and integrated by ISRO, the INSAT 4A and INSAT 4B satellites will each weigh about 3,200 kg at liftoff.

INSAT-4 series is planned to have seven satellites, INSAT-4A through INSAT-4G with INSAT-4D as a spare. The transponder capacity of this series has been worked out after evaluating the requirement projected by different uses/user departments. It is planned that, by 2007, the INSAT system will have about 250 transponders in various bands catering to a demand of up to 11 Giga Bits Per Second (GBPS) capacity.

MSG (Meteosat Second Generation) features 12 channels enhanced imaging radiometer (SEVIRI) and the Geostationary Earth Radiation Budget (GERB) instrument.

The high performance of the new generation is 4 times better than the other ones on the market and 10 times better than the Meteosat of the first generation.

They will ensure the continuity of current services and supply highly significant advances. The transmission rate of images is doubled (one image every 15 minutes) and the number of spectral channels rises from 3 to 12 (including 8 infrared channels), three allowing for access to comprehensive information on atmospheric physics. Spatial resolution is also enhanced: MSG is able to discern details down to 1 kilometer in a visible high-resolution channel and 3 kilometers for the other channels. The general concept is derived from the first generation, but the platform and payload are completely new.