When satellite television hit the market in the early 1990s, satellite dishes took up a lot of space and were highly expensive; therefore, it was much more difficult to obtain than cable television and rebroadcasting.
However, today we can see satellite dishes in most buildings and houses, both urban and rural. And, while satellite television technology is still evolving, the main companies that offer it attract more consumers every day.
The following describes how satellite television works, the changing landscape of television viewing, and some basic differences that distinguish satellite television from cable and over-the-air television.
Some problems with the television transmission
Satellite television is similar to broadcast television. It is a wireless system that allows television programming to be delivered directly to the viewer's home, through a radio signal. In this sense, the main limitation of open television is the range, since the radio signals used are fired from the transmitting antenna in a straight line; thus, to receive the signals, you must be in the direct line of sight of the antenna. Because the Earth is curved, it eventually breaks the signal's line of sight; an action that would not happen if it were flat. You may also be interested in “Sky tv network” here Whatsapp Sky
Additionally, another problem with broadcast television is that the signal is frequently distorted. To get a perfectly clear signal, like cable TV, you must be very close to the transmitting antenna, with no major obstacles in the way.
The satellite TV solution
Satellite television solves the range and distortion problems described above, as it transmits signals from satellites orbiting the Earth, allowing many more clients in line of sight. Satellite television systems transmit and receive radio signals, using satellite dishes.
Satellite television programming
Satellite TV providers get their programming from two main sources:
National responsive channels such as HBO, ESPN, and CNN.
Local channels, such as ABC, CBS, Fox, NBC, and PBS affiliates in a particular area.
The answering channels usually have a distribution center that transmits its programming to a geosynchronous satellite and, the transmission center uses large satellite dishes to capture these analog and digital signals.
Most local stations do not broadcast their programming to satellites, so the provider has to get it some other way. If the provider includes local programming in a particular area, it will have a small local facility. The equipment receives local signals directly from the station, through a fiber optic cable or an antenna, and then transmits them to the transmission center.
To transmit the signal, the transmitting center has to compress it. Otherwise, it would be too big to be handled by the satellite.
Satellite television signal
Given that satellite signals contain high-quality digital data, it would be impossible to transmit it without compression, which means that unnecessary or repetitive information is removed from the signal before it is transmitted. Then it rebuilds after transmission.
Compression standards
Satellite television uses a special type of video file compression, standardized by the Moving Picture Experts Group (MPEG). Currently, there are five MPEG standards, each with a different purpose.
DirecTV and DISH Network use MPEG-4 compression, as MPEG-4 was designed to transmit video on small screens, such as computers. However, MPEG-2 is still the official standard for digital television compression, but it is better equipped to analyze still images than dynamic moving images; while MPEG-4 can better produce dynamic images, by using spatial and temporal compression. For this reason, satellite television uses MPEG-4 compression and provides a high definition of fast-moving objects that constantly change location and direction, just like in a basketball game.
Encoding and encryption of satellite television
High-quality digital video transmission goes through a MPEG encoder, which converts programming to MPEG-4 video. That encoding process works in conjunction with compression to analyze each frame of video, and eliminate redundant or irrelevant data, reducing the overall size of the file.
Occasionally, this process produces artifacts: video image glitches. One artifact is macro-blocking, in which the fluid image is temporarily dissolved into blocks (this has been mistakenly called ‘pixelating').
The compression rate depends on the nature of the programming. If the encoder is converting a newscast, it can use many more predicted frames because most of the scene remains the same from one frame to the next, unlike in faster programming.
Encryption and transmission
When the video has already been compressed, the provider encrypts it to prevent people from accessing it for free. Encryption scrambles data in such a way that it can only be decrypted (converted back to usable data) if the receiver has the correct decryption algorithm and security keys.
Once the signal is compressed and encrypted, the transmission center transmits it directly to one of its satellites; it captures it, amplifies it, and sends it back to Earth, so that viewers can capture it.
Satellite receiver
The final component of the entire satellite television system is the receiver, which has four essential functions:
Decode the encrypted signal.
It takes the MPEG-2 or MPEG-4 digital signal and converts it to an analog format that a standard television can recognize.
Extracts individual channels from the largest satellite signal. When the channel is changed on the receiver, it sends only the signal for that channel to your TV; In that sense, since the receiver spits out only one channel at a time, it cannot record one program and watch another.
It tracks pay-per-view programs and periodically communicates billing information to a computer at the provider's headquarters.
Additionally, the receivers also allow:
Collect a programming signal from the provider and present that information in an on-screen programming guide.
Have parental lock options.
Pause live television or record it to a hard drive, if they have built-in digital video recorders (DVRs).
These receiver features are just additional benefits to satellite TV technology. With its cinema-quality picture and sound, satellite television is becoming a popular investment for consumers.
Do you have questions or want to purchase our products? At AXESS we are willing to provide you with solutions tailored to your needs and your business requirements.
