A Layman’s Guide in Understanding Broadcast Television

Ever wondered how we get the signals on our television sets in high definition (HD)? Here is a basic understanding of the key elements.

The first element that helps is the set-top box that contains the heart of DVB-S2 system (Digital Video Broadcasting – Satellite – Second Generation system). This technology is a standard established by DVB Project which is a consortium of technology partners in the telecommunication industry. The standard was brought into play to augment electronic news gathering by mobile vans that sent sound and video from various locations to a central studio which in turn edited and or collated to send the signals to our televisions.

DVB-S2 is now used widely for internet access, HDTV (High Definition television) and Standard Definition content. A prime feature of the DVB-S2 system uses a phased-locked loop oscillation control system to form the basis for a DVB-S2 modulator control system to modulate the phase of an output signal in relation to the phase of an input signal. The use of a variable phase lock oscillator and a phase detector do the trick. To put it simply phased lock loops synchronize phase and frequency of input video signals to the output.

The third key element responsible for displaying images and sound on our televisions is the unit in the front of the small dish antennae that is now ubiquitous in every home across the world. It is called a LNB short for low noise block downconverter. The LNB receives radio waves from the dish The LNB Amplifies the extremely low level signals from the Satellite and then down converts them to an intermediate block of frequencies so that a very low priced co-axial cable can carry the signal to the set-top box.