Briefing: Freeview channels using DVB-T2

DVB-T2 is the second generation of digital broadcasting via a terrestrial TV network. The UK launched the world's first DVB-T2 service in late 2009.

Digital multiplexes (groups of channels bundled together and broadcast on a terrestrial TV frequency) originally used the original DVB-T standard. However, multiplexes that use DVB-T2 can utilise more bandwidth, which is why Ofcom decreed that HD channels would use the standard in the UK on Freeview.

DVB-T could potentially accommodate three HD channels per multiplex, whereas DVB-T2 facilitates up to five HD channels. As terrestrial TV distribution is costly, the more channels can fit on a multiplex, the lower the cost of distribution per channel can be.

Viewers need to have a Freeview HD certified receiver to be able to watch the full range of channels available through an aerial. The number of channels available depends on location, with a minimum of six HD channels available.

Freeview HD certified receivers are designed to receive DVB-T2 signals as well as the original DVB-T type of service.

Normal Freeview receivers and "HD ready" receivers without Freeview HD certification will only be able to receive a reduced number of channels.

Based on the current configuration of national DVB-T2 multiplexes in the UK, using the MPEG4 video codec, five HD channels can fit on a multiplex.

Until January 2014, standard definition (SD) channels exclusively used DVB-T multiplexes, while HD channels exclusively used DVB-T2 multiplexes - except in Northern Ireland, where Ireland's RTÉ One, Two and TG4 used the DVB-T2 standard to broadcast their channels in standard definition from 2012 on a specially configured multiplex enabling viewers to access Irish TV in more places north of the border.

On the 16th January 2014, a SD channel - Al Jazeera Arabic - launched on a national DVB-T2 multiplex, becoming the first SD channel on a UK DVB-T2 multiplex outside of Northern Ireland.

Over the course of the next decade, the broadcast industry is poised to move all terrestrial channels to the DVB-T2 standard. Sadly, this won't mean more channels, as HD services use more bandwidth and will use up the extra capacity created. Additionally, some TV frequencies could be re-used for more mobile broadband services, limiting any potential for more services.



UK national Freeview:
DVB-T
DVB-T2
MPEG2 video
MPEG4 video
Up to 13 SD channels*
Up to 5 HD channels

Can be used for SD channels as well.
Up to 24-27 Mbps bandwidth^
Up to 40 Mbps bandwidth
Services can be viewed with a Freeview, Freeview HD or YouView receiver.
Services can only be viewed with a Freeview HD or YouView receiver.
*using ¾ resolution 544x576
^commercial multiplexes use a different error correction rate giving them 27 Mbps bandwidth



UK local Freeview:
DVB-T (Comux)
DVB-T2 (Northern Ireland Mux)
MPEG2 video
MPEG4 video
Using QPSK modulation, so less bandwidth but more robust reception of low power localised multiplex signals.
Using QPSK modulation, so less bandwidth but more robust reception of low power localised multiplex signals.
Up to 3 SD channels
Up to 3 SD channels
Up to 9 Mbps bandwidth
Up to 9.9 Mbps bandwidth
Services can be viewed with a Freeview, Freeview HD or YouView receiver.
Services can only be viewed with a Freeview HD or YouView receiver.
The above table does not apply to the Manchester Television Multiplex, which has similar characteristics to the national multiplexes.


Related Link:
UK DTT multiplex capacity guide



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1 comments:

  1. So has this new Arabic service effectively blocked a potential 5th HD channel on that multiplex, or was a 5th channel in HD not going to happen anyhow?
    Much chance of more HD services in 2014?

    ReplyDelete

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