Quite simply put a digital TV signal is just a transmission that contains information regarding the video and audio components of a broadcast from the television station direct to the end user.
How Are Digital TV Signals Transmitted and Made
Before transmitting signals over long distances, a television station first takes the audio and video signals compressing them into a single signal suitable for transmission. This is then sent out of the earth’s atmosphere to a satellite that amplifies the signal and sends it back to various television receiver towers that accept microwave frequency signals all over the world. Then these towers convert the signals back into terrestrial signals suitable for low range transmission before sending them out in all directions. The antenna in your home picks up the signal converting it back to the original form by separating audio from video.
How Do You Receive Digital Signals At Home
There are many methods to receive a digital signal transmission. One of the oldest methods is to use a Digital TV and an antenna. This will however restrict viewers to the total number of channels on air and signal strength varies based on frequency used for each signal.
A more commonly seen method of transmission today is the use of digital satellite receivers and digital cable. Digital satellite receivers take in microwave signals, decode them into TV compliant signals and deliver them to end users while digital cables simply carry signals from the service provider directly to the television of the end user. Some of the standards used for either methods of receiving include Digital multimedia broadcasting and DVB-H.
A modern method of receiving digital TV signals is through IPTV or TV using Internet Protocol. They rely on a DSL or Digital Subscriber Line. Internet users can also receive free channels online using P2P television software or flash websites.
Encryption Protocol Commonly Used
Many service providers today encrypt their digital signals to ensure that they may not be recorded or viewed by many users. To access these channels, smart cards are used which are basically key generators that can decrypt signals for home users. Sometimes, signals transmitted by broadcasting stations are encrypted or encoded to ensure that they reach the destination with minimal loss of strength.
Factors That Affect Digital TV Signal
There are many factors that can play havoc with digital TV signals. Some of them include weather conditions, improper antenna orientation and damaged receivers. Interference with digital signals happens when the antenna starts picking up other signals that overpower the actual transmission it is supposed to catch. This can happen because the waves have lost signal strength over long distances or the device has grown weak. A common problem with digital receivers is that it can suddenly change from perfect video condition to no video, which is known as the cliff effect.
In remote locations with uneven terrain, digital signals can get cut off due to a sudden drop or rise in sea level. Since digital signals require a straight line of sight to catch them, interference becomes a major issue in hilly areas with digital antennas. Hence, the use of satellite receivers is preferable in such areas.