A transponder is an electronic device on a satellite which facilitates communication from source to destination. It receives the signals through uplink frequency, translates it into downlink frequency, amplifies it and beams back to earth.

The major frequency bands used for satellite communication in India are S-band, C-band, Upper Extended C band, Ku band and Ka band. The INSAT/GSAT satellites carry transponders in these bands.

The operations of communication satellites over India are governed by “A policy framework for satellite communication in India” commonly known as Satcom Policy and the “norms, guidelines and procedures for implementation of the policy frame-work for satellite communications in India” commonly known as Satcom NGP which were approved by the Government in 1997 & 2000 respectively. Copies of these documents are available in www.isro.gov.in .

Any Communication or Broadcast service provider or and an agency intending to establish Satcom network can avail the satellite capacity/bandwidth by submitting their requirement through INSAT/GSAT Capacity Requirement Format (ICRF). Guidelines for Registration of INSAT/GSAT Capacity Requirement are available in www.isro.gov.in . Operating and other relevant licenses are required from DOT for telecommunication services and from MoIB for broadcasting services.

Use of a foreign satellite for communication services over India is permitted as per the provisions of Satcom Policy and GOI regulations, guidelines & procedures. Any requirement of capacity on foreign satellites has to be registered through ICRF. Only television broadcasters are permitted to avail C-band capacity from foreign satellites directly which will be scrutinized and permitted for use by MOIB & DOS.