Satellite Television

Satellite television is a television transmission method of making a bounce off a communications satellite television signal emitted from a point on the Earth, so that it can reach other parts of the planet. In this way the distribution of television signals to large tracts of land, regardless of its mountainous nature.

There are three types of television satellite direct reception by the viewer (DBS) reception for the heads of cable television (for onward distribution) and services from local TV affiliates.
Since the Soviet Union put into orbit by the year 1957, the first satellite, called Sputnik 1 was launched thousands of these devices for all kinds of purposes. One use is hanging over the telecommunications, from which it was possible the spread of television signal providing almost complete coverage for large areas of land.

Since launching the first satellite had been several important developments emerging from the point of satellite television, such as the issuance of the first television signal, the year 1962, using the satellite Telstar 1 launch the first satellite broadcast Direct (DBS), the Ekran designed to receive TV signal at home. The use of communications satellites has been expanded to the point where there are currently more than 300 communications satellites in geostationary orbit, broadcasting TV signals anywhere in the world. The system of satellite television in Latin America is that of having SKY Latinomérica around 1.4 million subscribers in Mexico and Brazil. And DirecTV provides the same service to the rest of the Americas with a total of 1.3 million subscribers, but such services for pay is not very popular due to the high subscription prices. Services in Brazil include television with Dolby Digital to manage a new technology in the field of satellite television in Brazil. DirecTV also included as SKY and SKY + DirecTV Plus DVR, a novel system that can record, rewind and pause live programs while watching another, however this service is extremely expensive, so it does not make a lot of subscribers.

Standards

The analogue television signal is formed by a satellite video signal frequency modulated (FM) and a Subcarrier, usually between 5.5 and 8.5 MHz in FM modulated signal with associated audio. It is customary to use one of these transmission systems: PAL, NTSC or SECAM. [2]

However, if digital is customary to follow the DVB-S or its latest update, the DVB-S2. Thus, the codec used for this type of transmission is MPEG-2, although it is increasingly using the MPEG4 AVC due to increased content of high definition (HDTV). Although these standards allow the use of several modules, the most widespread is the QPSK.