How ISRO’s Communication Satellites Will Boost Internet Speed In India

The Indian Space Research Organization (ISRO) is planing to launch three communications satellites which will significantly improve the speed at which internet is available to 350 million users in the country. The three ISRO satellites - GSAT-19, GSAT-11 and GSAT-20 - will increase the speed by increasing the number of transponders available for communications.

According to ISRO chairman Kiran Kumar, “these satellites will use multiple spot beams (a special kind of transponder that operates on a high frequency) that will increase internet speed and connectivity. These multiple spot beams will cover the entire country."

Spot beams are satellite signals that are specially concentrated so that they cover only a limited geographic area on earth. As each spot beam is responsible for a small geographical area, say a city or a town, the quality of connectivity will improve. Traditional satellites use a broad single beam to cover wider geographical areas. However, for better connectivity, the beams should be narrow. The narrower the beam, more is the power.

The three satellites will be sent into orbit using GSLV Mark-III, which uses India’s fully indigenous cryogenic engine that is capable of carrying a four-tonne satellite to the geosynchronous transfer orbit. The first test of this newly developed launch vehicle will be conducted at the end of this month, the Economic Times has reported.

According to Tapan Misra, director of Ahmedabad-based Space Application Centre, “GSAT-11, which is heavier than GSAT-19, will be launched by the year-end and will use 16 beams. It will be able to transfer data at the rate of 13 gigabytes per second. GSAT-20, whose launch is set at the end of 2018, will use 40 beams. Each beam will have two polarisations, which will effectively make them 80 beams. This satellite will have data rate of 60-70 gigabytes/sec”.

The effective data rate of previously launched communication satellites is one gigabyte per second. GSAT-19, on the other hand, will be able to transfer data at four gigabytes per second, thus making it equivalent to four satellites.