PVRs: How to buy the best PVR Digital TV broadcasts – DVB
Digital video broadcasting
Digital video broadcasting, or DVB, can be transmitted in a number of ways.
When transmitted via a satellite TV service, such as Sky or Freesat, it’s known as DVB-S (the ‘S’ stands for satellite). If transmitted by a terrestrial service such Freeview it’s known as DVB-T or digital video broadcasting – terrestrial.
When broadcasters use this method, the digital signals do not leave the earth – they go from the transmitter antenna directly to your rooftop aerial.
The terrestrial transmission method has different names in different parts of the world. DVB-T is the name used in Europe and Australia.
North American customers receive these signals using a set of standards approved by the Advanced Television Systems Committee (ATSC).
In Japan, it is known as Integrated Services Digital Broadcasting–Terrestrial (IDSB-T).
DVB-T broadcasters transmit data using a compressed digital audio-video stream, with the entire process based on the MPEG-2 standard. These transmissions can include all kinds of digital broadcasting, including HD TV and other high-definition methods.
Several digital channels are usually transmitted together in a package of data known as a multiplex, which the digital receiver or set-top box unscrambles.
This is a vast improvement over the old analogue signals, which required separate streams of transmission, and saves on the amount of radio bandwidth required.