The city of Ahmedabad has Space Application Center(SAC) of Indian Space Research Organization(ISRO) located on Satellite road. SAC primarily works for Pay-load of India’s satellites. Pay-load actually execute the tasks for which a particular satellite is released.

In reference to recently launched GSAT-8, it would be interesting for you to note that its payloads are ‘made in Ahmedabad’.

The GSAT-8 is carrying a payload(GAGAN) that will broadcast data to increase the accuracy and ensure the integrity of navigation based on signals from orbiting satellites of the U.S. Global Positioning System (GPS) and the Russian Global Navigation Satellite System (GLONASS). The resulting improvement in accuracy and reliability will allow aircraft, equipped with suitable receivers, to make precision approaches for landing at all runways in the country. Aircraft will also be able to fly more direct routes to their destination, saving time and fuel. Such space-based augmentation systems have begun functioning in the U.S., Europe, and Japan. Ground stations for the Indian system, known as GAGAN (GPS Aided GEO Augmented Navigation), a joint effort by ISRO and the Airports Authority of India, have been put in place. After the GSAT-8’s GAGAN payload becomes operational, further steps for testing the system as a whole and securing the necessary certification can start.(from The Hindu’s editorial)

The GSAT-8 satellite carries on-board 24 transponders that receive and send radio signals mainly for direct-to-home broadcast. With GSAT- 8, the number of transponders available with the Indian Space Research Organization ( Isro) will go up to 175 from current 151. In the beginning of the 11th five year plan, India had 211 transponders in different bands. Some satellites have completed their normal life, while others have been decommissioned. INSAT- 4B partially failed in May 2010 leaving Isro with a shortage filled by foreign transponders on lease.(From India Today)

More detail on GSAT-8 can be found on this page of ISRO

More details on SAC Ahmedabad can be found on this website