Thursday, 27 March 2008



HD digital TV breakdown.
High Definition television transmits more picture information and better quality sound than traditional standard definition television.
So what exactly does this mean to Joe Public?
The breakdown;; future broadcasts will soon be mixed with SD or Standard Definition and HD or High Definition and we will certainly see a slow transitional move to more and more High Definition (HD) programming.
HD or High Definition picture quality is around five times clearer than exisitng TV pictures and HD sound can be surround sound is more immersive. You only have to view a nature or sport feature once, and your hooked. You will also read and hear about upscaling of pictures which again is better than normal SD or Standard Television, but is your poor mans High Definition (HD) in comparison to proper HD.
To understand further we need to take a look at Multiplex,DVB-T and the futures DVB-T2.
A Multiplex is a set MHz block of UHF spectrum which carries a bundle of digital TV channels. 1 digital Multiplex occupies the same amount of spectrum as a single analogue TV channel.
DVB-T technology is referred to as modulation with respect to digital TV signals
and the current standard is named DVB-T, this allows more efficient use of the Multiplex spectrum. DVB-T2 is in development.
Digital Multiplex transmission is subject to trade-off between coverage, capacity and resilience to interference. At present, digital television is transmitted in the spectrum gaps between analogue television channels. See our FAQ's page for more detail.
The BBC make a cautious trade-off at 16QAM mode between coverage, capacity and interference in order to ensure consumers receive a robust signal. As digital switchover proceeds and interference from analogue channels stops being an issue, the BBC will convert its Multiplexes to 64 QAM mode, enabling more channels to be carried in the Mulitplex spectrum.

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