ISRO's newer geostationary communication satellites, which followed INSAT. The first, GSAT-1, flew on GSLV's first flight in April 2001.
GSAT satellites carry transponders for television, VSAT networks, internet and telephone links. They are used by both government and private users. The transponders are designed at the Space Applications Centre.
Some recent satellites in the series carry CMS names, such as CMS-01 and CMS-03.
The series runs from GSAT-1 to GSAT-N2 and CMS-03. Some were launched on India's GSLV and LVM3 rockets. Others flew on Europe's Ariane-5 from Kourou, and GSAT-N2 flew on a SpaceX Falcon 9. The Master Control Facility controls them in orbit.
ISRO lists most GSAT satellites launched since 2012, and CMS-01 and CMS-03, as operational.