Digital Satellite System is the expansion of the DSS Digital Satellite Television Transmission system. It is used by DirecTV. When the digital transmission was launched, digital broadcast satellite (DBS) television become famous in North America, and it has led to both digital broadcast satellite and digital satellite system being used interchangeably in order to refer to all three commonplace digital transmission formats, including digital satellite services, DVB-S, and 4DTV. However, analog DBS services existed prior to DirecTV, and it was still operational in continental Europe until April 2012.
When DirecTV was launched in the year 1994, the DVB-S digital satellite system had not yet been standardized. At that time, the Thomson developed DSS System was used. It functions similar in DVB – MPEG 2 video, QPSK modulation, MPEG-1 Layer II or AC3 audio, identical error correction, the transport stream as well as information tables are different from those of DVB. Unlike DVB, all DSS receivers are proprietary DirecTV reception units.
DirecTV is using a modified version of DVB-S2. It is the latest version of the DVB-protocol for HDTV services off the SPACEWAY-1, SPACEWAY-2, DirecTV-10, and DirecTV-11 satellite. However, a huge number of DSS encoded channels still remain. The ACM modulation scheme used by DirecTV prevents DVB-S2 demodulators from getting the signal, although the data carried are MPEG-4 transport streams.
DSS is a proprietary video as well as an audio distribution system used by DirecTV. DSS is a type of DBS system. It is commonly used interchangeably with DSS, but DBS refers to any satellite transmission intended for home reception. As DSS is a proprietary technology of DirecTV, there is no official documentation of DSS standards.
Technical Details of Digital Satellite Services and Its Advantages
Technical details are based on some basic facts, including
- DirecTV DSS systems broadcast over Ku Band.
- DSS uses QPSK modulation along with 127-byte packets.
- DSS uses the Viterbi as well as Reed-Solomon algorithms for fault detection as well as correction, with variable-rate forward fault correction to squeeze the max available bandwidth out of each satellite transponder.
- DSS also uses the VideoGuard conditional access system from NDS.
- The main audio encoding system used by DSS is Musicam, and it supports AC3.
There are several benefits of digital satellite TV. Take a look at some of them:
Dishes: When satellite TV was launched, an effective signal needed that you have a large dish, and it would be able to move to pick up the signals from several satellites. These days, the dishes are small in sizes, and installers can place them on the roof of homes where they receive the best signals. In addition, dishes are now stationary, which makes them quite expensive. However, satellite television companies offer the equipment free-of-charge if you sign up for 12 months.
Picture quality: Talking about picture quality, it is much more superior as compared to cable TV because of the way the signal is transmitted to your home. Satellite users get a signal that is once removed from the original source. However, cable companies string wires all the way to your home, and you are away from their hubs. Hence, you get a poor picture.
More choices: As a satellite can transmit signals from stations around the earth, you get any station with which the satellite company has a contract. Satellite TV providers offer a wide choice of channels than most cable companies.
Cost: As you know, satellite TV providers offer more channels than cable companies; many channels provided by cable companies are just available at an additional cost. With satellite TV providers, there is no need to pay extra.