18 March 2013
4G mobile services will interfere with some Freeview broadcasts when they arrive on the 800MHz radio band from Spring 2013. This is the 4G Freeview Fail.
The 4G Freeview Fail could prevent hundreds of thousands of homes from getting Freeview, forcing them to install signal filters if they’re to continue watching Freeview.
The (previous) government may be to blame for the poor planning that's lead to the clash of Freeview and 4G, but it's the mobile networks who will be stumping up the cash to fund a company called Digital Mobile Spectrum Limited.
AT800.tv - the public name for Digital Mobile Spectrum Limited (formerly known as MitCo) - will oversee the provision of 4G signal filters which people can connect to their Freeview aerial to help tune out 4G interference.
They're already available AT A PRICE, but if you've got an amplifier in the loft or on your aerial and you need to get a man in to fix it, the cost of installing 4G signal filters should be covered by the provision of £50 vouchers (I don’t think so) which will be handed out to the homes that need them. No one has discussed commercial premises yet ???? Bet we don’t get the vouchers.
UK minister for culture, communications and creative industries, Ed Vaizey, has announced: Only 900,000 are likely to rely on “Freeview” for their primary viewing, so in effect, fewer than a million people will be directly affected. The rest will be viewing television on satellite cable or broadband. Oh really Mr Vaizey! With this in mind it’s likely at this stage that vouchers will be made available for 900,000 homes, despite around 2.3 million homes affected.
4G Freeview Fail: How will it affect Freeview?
Retunes
The first problem is that some Freeview signals already use the lower end of the 800MHz band, so they will have to be moved before 4G networks can launch on these frequencies.
The affected areas will be notified in advance, and are currently going through a retune similar to the Digital Switchover. No-one will need a new Freeview box at this point, although some people may need a new aerial.
Adjacent interference
The second problem is that the international engineering teams which assigned the 4G signals to 800MHz didn't leave a large enough 'guard interval' between the bottom of the 800MHz band and the top of the 700MHz band, because radio signals always overspill a little from their assigned frequencies. No-one knows why, but the suspicion is that they were all mobile communications experts, and no-one bothered to ask a broadcast TV expert to check detail.
Mobile phone signals are likely to leak across from 800MHz and interfere with some TV at the top end of 700MHz, and in some cases it can be fixed with a simple filter, but in others the interference will be too strong, and TVs will lose some of their Freeview channels.
Out-of-channel interference
We've all heard the clicks and pops when someone is talking on a microphone and there's a mobile phone in their pocket. The microphone wire acts as an aerial and can pick up all kinds of frequencies if they're strong enough.
Digital TV boxes aren't designed to filter out interference from devices using the 800MHz, so even Virgin Media cable boxes could be affected if there's a 4G dongle or handset close by.
What if I still can’t get Freeview after installing a filter?
Ed Vaizey has announced that there will be assistance for homes to switch to 'free-to-view satellite' (Freesat) or 'cable TV' (Virgin Media) if they can’t get Freeview after 4G arrives.
In cases where dishes can’t be fixed to homes or cable isn’t available (Ofcom estimates 500) it instead 'may be appropriate to look at alternative ways of restoring good DTT reception, up to a limit of £10,000 per household'.
For those not in this category, it is estimated that at the most, 38,000 homes will be offered Virgin Media or Freesat.
Which mobile networks will affect Freeview?
EE (incorporating Orange and T-Mobile) has already launched 4G on the 1800MHz band. This is entirely separate to the 800MHz band which Freeview currently uses and therefore will not interfere with it.
As the 4G auction kicks off in the UK other networks will use the 800MHz band for their 4G services, which will interfere with Freeview reception in some areas.
Currently, the UK mobile networks use three frequency bands - 900 MHz, 1800 MHz and 2.1 GHz - to broadcast 2G voice and 3G data services, but Ofcom is currently considering a plan to allow them to use this for 4G as well.
As a condition of the Orange and T-Mobile merger, it's expected that Three will be gifted a portion of the 1800MHz band to use for 4G. Again, this will not interfere with Freeview.
Ofcom's 4G auction has allocated parts of the 800MHz and 2.6GHz spectrum for 4G services, and it's the 800MHz portion which will cause problems.
SO THERE YOU HAVE IT – “OH HAPPY DAYS ARE HERE AGAIN”
Read other articles
Back