Indian National Satellite System (INSAT) is an adaptable Geostationary satellites launched by Indian Space Research Organization (ISRO) to secure the telecommunication systems, broadcasting , atmospheric conditions & search and secure operations .
it is an joint venture of Department of space , Department of telecommunications, India metrological department , All India Radio & Doordarshan. it is authorized in 1983; it is an largest domestic communication system in Indo pacific region. The overall management and firm of INSAT system rests with secretary level committee.
The INSAT had been an prime incentive for the augmentation of television coverage in India. Satellite television covers 100% of population and 100% area. the terrestrial coverage is 81% of Indian land mass & 92% of population. Doordarshan is a major user of INSAT satellites for providing television services over the country. At present, 33 Doordarshan TV channels are operating through C-band transponders of INSAT-3A, INSAT-3C, and INSAT-4B. All of the Satellite TV channels are digitalized.
The following satellite television services are being operated by Doordarshan:
National networking service (DD-1), DD News (DD-2), DD-Sports, DD-Urdu, DD-India, DD-Bharati and DD-HD
Regional services in the states of Kerala, Karnataka, Jammu & Kashmir, Tamil Nadu, West Bengal, Andhra Pradesh, Gujarat, UP, Assam, Maharashtra, Punjab, Himachal Pradesh, Rajasthan, Tripura, Odisha, Bihar, Madhya Pradesh, Uttarakhand (Uttaranchal), Haryana, Mizoram, Jharkhand, Manipur, Arunachal Pradesh, Chhattisgarh, Andaman & Nicobar Islands and Lakshadweep Islands . Around 1415 transmitters of Doordarshan are working through INSAT system to cater to DD-1 network, DD-News network and Regional services. 59 Doordarshan and Private TV channels are operational through DTH service (“DD Direct+”). 10 channel DTH planned in C-Band for Andaman & Nicobar Islands national since September 17, 2009. DD HD Service has been started on October 03, 2010 with the start of Commonwealth Games 2010.
DTH services are becoming popular with the introduction of premium services like HDTV services, On-demand movie services, etc. High power Ku-band transponders are used to support DTH television service with smallest dish antenna all over India. About 75 Ku-band transponders from INSAT/GSAT and Leased satellites are catering to DTH television services. More than 40 million DTH connections are subscribed to various DTH television providers, including DD Direct +. 
