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RISE OF FM TECHNIQUE
FM broadcasts were introduced in Madras in 1977 and later at Jalandhar in 1992, but it was only in 1993 when slots came to be leased to private companies.
On August 15, 1993 a Frequency Modulation (FM) Channel was launched in Bombay, with nine hours of radio which sloats was leased to private producers like Times FM, radiostar and Radio Midday.
In FM Phase II some 338 frequencies were offered of which about 237 were sold.
Why FM is better then AM ???
Here is an example of both FM modulation and AM modulation you can see from the image that AM is much looser than the FM signal meaning that less data can be sent at one time as it isn’t compressed. The reason for the difference in sound quality as a lower bitrate must be sent across the wave.
ADVANTAGE
This is only means which can provide multi access two way communication.
The cost of transmitting information through satellite is independent of
distance involved.
Satellite can be used for two way communication or broadcast purpose with
the covered area.
Satellites are capable of handling very high bandwidth.
It is possible to provide large coverage using satellite. For example
Geostationary satellite can cover about 42% of earth surface using global
beam.