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Analysis: Ofcom postpones 600 MHz digital TV auction as more frequencies are poised to be given over to mobile broadband


The UK's broadcasting and telecommunications regulator has reportedly postponed plans for an auction of a chunk of frequencies on the UHF waveband, notably used in much of the UK by Channel 5 analogue ahead of switchover, as it becomes ever more likely that more of the TV waveband will be turned over to mobile broadband services and more households will need to purchase filters to stop broadband services affecting their terrestrial TV reception.

UHF channels 31-37 are currently being cleared through the digital switchover process. These UHF channels were going to be part of the 600 MHz auction of UHF frequencies, widely thought to be reused for up to 3 additional digital TV multiplexes in much of the UK. Originally, the section of the UHF waveband up for grabs included UHF channels 39 and 40, but these were subsequently reused to accommodate services moving from higher up the band as part of the 800 MHz clearance for 4G mobile broadband services.

The 800 MHz part of the UHF band (channels 61 upward) is in the process of being cleared for 4G mobile services. Now, following the recent ITU WRC 2012 conference, where countries negotiate use of frequencies, countries in Africa and the Middle East have been allowed to convert the 700 MHz part of the UHF band (channels 49-60). They join the USA and other parts of the world in doing so.

In a global marketplace, it is likely that devices designed to use the 700 MHz band will become widely available over the next five to ten years. Europe, where the 700 MHz band is intensively used for television services, sticks out like a sore thumb. As regulators strive to ensure that enough bandwidth remains available to consumers and businesses who will be using the mobile broadband networks more intensively for video streaming, global harmonisation of the 700 MHz band for use by telecommunications companies is becoming increasingly likely.

In order to accommodate both increased bandwidth for mobile broadband and frequencies for UK digital multiplexes, which are licenced or pending to be licenced into the 2020s, Ofcom appears to be recognising that the 600 MHz band, previously earmarked for further TV multiplexes will now have to be used to move displaced services from the 700 MHz band.

However, in order to fully do this, the more spectrum efficient DVB-T2 standard will need to be implemented on more digital multiplexes. DVB-T2 is already used for the Freeview HD multiplex. Whilst Ofcom has not yet announced that this will happen, insiders recognise that a migration to DVB-T2 will be needed, in order to compress the existing digital services into fewer frequencies. Single Frequency Networks, where neighbouring transmitters use the same rather than different frequencies,  are easier to set up using DVB-T2. By way of comparison, if neighbouring transmitters would have used same frequencies using the 2k DVB-T system originally implemented in the UK for OnDigital/ITV Digital, the transmitters would have interfered with each other, rather than complement each other.

DVB-T2 is now being rapidly deployed in developing countries across Africa and Asia and is likely to become the main digital standard for terrestrial television outside of most of the Americas this decade.

Effect on consumers
A big knock on effect is likely to hit consumers of terrestrial television though: they are already required to retune at switchover and again in some areas during late 2012 and 2013 to allow frequencies to be cleared for 4G mobile broadband. These consumers would have to look at retuning again, as more services moved down the band from the 700 MHz band to the 600 MHz band. Additionally, more transmitters than ever would need to be reconfigured to new frequency allocations and certain types of terrestrial aerials (group C/D) would become redundant.

New Filters, please
Filters to block 4G interference to be installed in households over the next 18 months - the ones that the Department for Media, Culture and Sport (DCMS) are requiring successful bidders of the 4G spectrum to pay for, would become useless if the 700 MHz band was subsequently converted. Only last month did the DCMS announce a programme of installing filters to block the 800 MHz band from TV tuners*. As part of the measures, some households would be paid to get satellite or cable services, where terrestrial television reception would no longer be possible.

With a further clearance of more of the UHF band, these filters would need to be replaced with ones for both the 700 and 800 MHz band. Filters are expected to cost £10 per unit.

Ultimately, this is the beginning of the end for multi-channel digital linear broadcasts through the airwaves. Key channels such as BBC One, news and event channels will survive with appointment-to-view live event programming. But more and more of our TV consumption - particularly of dramas, documentaries and movies - is becoming on-demand, thanks to services such as BBC iPlayer and movie-to-TV services like Lovefilm. Most new TVs are smart TVs, enabled to connect to broadband. Broadband speeds  still lag behind other countries though, which affects the ability to watch content from broadband. Unlimited downloads come at a premium. So extra capacity on the UHF waveband for mobile internet could ironically be used for what it once was used: TV - this time as a on-demand service rather than a linear one-size-fits-all service.

* TV tuners are designed to receive services in the 800 MHz band. Until this year, that part of the waveband is still being used for TV services, so such tuners are required so that all services can be tuned in. Newer models will block the 800 MHz band. It will be a while before all households exclusively have devices that don't feature a tuner for those frequencies.