4G Mobile Broadband to cripple Freeview?
From 2013, we can expect faster mobile Internet, courtesy of new 4G mobile services. The down-side is these new services could kill Freeview reception for some. Here's our first thoughts on the 4G problem.
Listen to FrequencyCast Show 65 - 4G Mobile Broadband and Freeview Interference |
4G vs Freeview?
In Show 65, Carl and Pete discuss a problem that could affect 750,000 Freeview homes. Here's our transcript
Carl:
So Pete, what are you going to talk to me about today? I understand there's something worrying going on in the world, isn't there?
Pete:
Well, a little bit. In the last show, we worried everyone by talking about IPv6. Today I'm going to worry everyone about 4G, and its impact on TV.
Carl:
Ooh yeah - I remember this. Actually I'm slightly aroused - or excited by the concept of 4G and what's going to go on, but I'm actually quite curious about this. This is quite devastating to the world, isn't it?
Pete:
OK, well first off, what is 4G, Carl?
Carl:
A phone company or a provider, or something to do with telephones, yeah?
Pete:
Not quite; let me try and explain. So we've got 3G at the moment - that's the mobile internet. 4G is coming to the UK in 2013, and what that offers is really high-speed downloads onto your mobile device, your tablet, your smartphone, and we can expect speeds of up to 100 megabits per second when we get 4G.
Carl:
So the fourth generation of communications - is that right?
Pete:
That's about it, yeah, so 2G was the old digital phone network; 3G is what we've got now, which is the mobile internet; and this is going to be the high-speed mobile internet.
Carl:
That's what I like about technology - it's always looking forward to the future, isn't it?
Pete:
And do you know how 4G's been made possible?
Carl:
Added one to 3G?
Pete:
OK, so let's change to a slightly different topic: the digital TV switchover. Now, you now that's happening - when's that going to be complete?
Carl:
2012, isn't it?
Pete:
Spot on, and effectively, what we've got with our TV at the moment is, we have a band on UHF that goes between 21 and 68. They're the channels that we currently get our analogue TV on. With me so far?
Carl:
Yes, so that'd be all the terrestrial channels, like BBC1, BBC2 - am I right? - up to Channel 5, yeah?
Pete:
Correct, and that band is also being used by Freeview. When the switchover's completed, what's going to happen is channels 61 to 68 will be freed. So instead of going from 21 to 68, it will go from 21 to 60. The crucial thing is, this 61 to 68 bit will be freed and made available for 4G.
Carl:
So who's using it at the moment?
Pete:
Well, it's the TV companies, so between 61 and 68 in various parts of the UK. That's still where the analogue TV services are.
Carl:
So we're talking about terrestrial services - it's not redundant at the moment; they're actually going to sell it up and move them out?
Pete:
Exactly, so it's going to use less of the bandwidth, free up this new chunk of band, which is going to be sold on to companies that want to run the 4G mobile phone network, and for anyone technically-minded, 61 to 68 is 791 to 862 megahertz. How's that?
Carl:
Really far too technical for me, but I do understand this is actually quite important technical information, isn't it?
Pete:
So this band, 791 to 862, is going to be used for the 4G network, but there is a problem, and the problem could apparently be affecting about three-quarters of a million homes when 4G starts to roll out in 2013, meaning disruption to Freeview and loss of service.
Carl:
Ouch!
Pete:
Ouch indeed. Do you think that's something we should be worried about?
Carl:
It seems to me like there could be other problems, because if this is broadcast stuff, what about spill or bleed to other frequencies?
Pete:
Well, this has all come about as the result of an Ofcom report. Let me just read you this little quote here:
"Existing DTT receivers" (that's digital TV receivers) "... and aerials were designed to receive signals across the UHF band 470 to 862 megahertz. That included the whole of the 800 megahertz band. That means, in addition to receiving the wanted digital TV signal, they will also receive the unwanted signal from new mobile phone base stations, resulting in interference and degradation to DTT reception."
Carl:
Right - so there is going to be problems, then?
Pete:
But let me explain it fairly simply. If you've got a standard TV aerial up on the roof and a Freeview box, and you happen to be in range of one of these new 4G base stations when they come out, the signal from the 4G base station is effectively going to leak into your Freeview box. If that signal is particularly loud, it's going to upset your Freeview box, and it won't be able to receive the Freeview channels. The problem is really going to hit anyone that uses some kind of amplifier, and the most likely ones to be affected are people that have a masthead amplifier. Do you know what one of those is?
Carl:
Is that the one where the amplifier's actually attached to aerial, or the top of your roof, as opposed to a sub-unit in the house, or something? I'm thinking, can't we just buy a new box?
Pete:
Er, well no, because the boxes are designed to get every signal from 21 to 68, and the TV aerials are also designed to get those signals as well. So yeah, it is the amplifiers that are up on the aerial end, because they're very hard to do anything about. The other people that are going to be affected are people that live in flats where there's a communal TV aerial, because normally they have some kind of amplifier system that amplifies the signal and pushes it round all the flats. So anyone with an amplifier might find that, when 4G comes along, their Freeview box can't cope with the amplified signal coming in from 4G.
Carl:
That's a lot of unhappy bunnies. How many are we actually thinking here?
Pete:
760,000.
Carl:
Is that why you were complaining about running out of fingers the other day? - you were counting them all?
Pete:
And of course that's homes, so most homes having more than one person, it's going to be potentially well over a million people that could be impacted when this happens in 2013. However, there are some fixes.
Carl:
OK, have the government really thought about this? - what is the fix, if you're not going to buy a new box? What can we do?
Pete:
Right, show and tell time. I'm going to hand you something, Carl - what's that?
Carl:
Physically, it looks like one of those book readers - you know those ones with the battery in the bottom and the bendy thing? - it's about 8" long? I suppose that's what you're going to say that' what that looks like?
Pete:
What a terrible description - people at home aren't going to get any of that, well done. That's the worst description of this I've ever heard.
Carl:
I'd suppose you'd say it looks like a packet of polos with a cable sticking out of the top, wouldn't you?
An inline RF filter, to reduce interference to TV reception
Pete:
Yeah. So what it is, it's an aerial socket at one end, and an aerial plug at the other. What I'm holding here is what's called a highpass filter. Amateur radio operators tend to use these to get rid of interference from their hand radio equipment into a TV set, and effectively, when the 4G networks come online, these are going to be offered to anyone that's getting these interference problems.
Carl:
When you say "offered", offered at a price, or are they going to be given free?
Pete:
What they're looking to do is sell these things called bandpass filters, which will be about £10, but the government is making these 4G companies responsible for paying for these to be distributed. So in theory, you'll get one for free, if you're affected.
Carl:
So yet again, the phone companies are going to have to fork out millions upon millions. At least they cover their backs, which is more important, I'm guess, for the current users of these things.
Pete:
The interesting thing, though, is these filters are going to work in a lot of cases, but Ofcom is estimating 30,000 viewers won't be able to use one of these filters, either because their signal's right next to the 4G end of the band, or they're very close to a base station, so 30,000 people won't get these. The fix for them is to move to satellite TV or cable TV, which is not particularly good.
Carl:
That's not really the result we're looking for, is it?
Pete:
In our forum, we had a message from Brian Hutchings, and I'm going to read this in its entirety. "This could be very bad news for me, being a disabled pensioner that watches a lot of TV. I did try to have Freesat installed, but the engineer said it was not possible, because we are almost entirely surrounded by tall trees, and he could not align my aerial with a local transmitter. I am using a mast top amplifier, plus one internally, and reception is very good. If this change goes ahead, it will be a disaster for me, as cable is not available in my area" - and I have a sneaking suspicion that Brian isn't going to be the only one affected, by a long way.
Carl:
No, there are lots of people that live in tall trees. So, what else have you got to destroy my life with?
Continues: Show 65 Transcript Part 2
Listen to FrequencyCast Show 65 - 4G Mobile Broadband and Freeview Interference |
More information:
- Freeview Reception advice - Some help on Freeview interference from the FrequencyCast team
- 4G and Freeview Interference - Your top 10 questions
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