It is necessary to use satellites for ling distance TV transmission. Why ?

Explanation

In order to send radio waves to a very large distance, we have to keep its frequency very high. Now, radio waves with frequency greater than 30 MHz are found to be pentrating the ionosphere. i.e. they do not return to Earth after reflection. Moreover at this high frequency, ground wave propagation is also not possible (because of very large amount of energy gets absorbed in this case). Thus, for very long distance communication and for covering entire surface of earth, use of satellites is quite inevitable (compulsory).