4G operators move into new homes in the spectrum 'hood

Another £27m changes hands

By Bill Ray, 4th March 2013

Regcast training : Hyper-V 3.0, VM high availability and disaster recovery

Bidders in the UK's spectrum auction have now sorted out who's going where, and who's going to knock out our TV reception once the 4G networks get switched on.

There were two bits of spectrum auctioned off: the low-frequency 800MHz band, which was freed up when analogue terrestrial TV was switched off, and the higher-frequency 2.6 GHz band.

The auction wound up a couple of weeks back, but that only decided how much spectrum each company would get. Working out which company gets which block has taken another fortnight and seen another £27m change hands as operators vied to add the perfect spectrum to their portfolio.

The snapshot of the 800MHz band shows us that Three, the UK's smallest network operator, will be snuggling up to the Freeview transmissions, so it will be more concerned than most with the progress of AT800 - the body charged with preventing undue interference to our TV viewing.

Vodafone stumped up an additional £12m to put a little distance between itself and Freeview, though EE managed to achieve the same thing without cost.

The middle block is the Time Division Duplex spectrum, the surrounding ones are uplink and downlink pairs

In the 2.6GHz band, only BT-subsidiary Niche Spectrum paid out for a specific allocation, handing Ofcom another £15m to secure the FDD block it wanted.

Operators want specific blocks because they've already started deploying networks on the basis that they would get them, or at least buying kit ready for deployment. Those deployments can be changed, but in some cases it's easier to buy the right wavelength and the two-phase auction was designed to facilitate that.

Being next to Freeview isn't a big deal: any operator could interfere with TV reception and they're all contributing to the £180m mitigation fund, but Three's 4G transmissions will, in some areas, be a single megahertz away from the BBC - and so will likely suffer more than the rest.

Now that the frequencies have been allocated the networks can be switched on. Soon we'll find out just how bad the interference problem will really be. ®

Regcast training : Hyper-V 3.0, VM high availability and disaster recovery

COMMENTS

House Rules Send Corrections

All Reader Comments (13)

Highly Rated

Posted Monday 4th March 2013 15:28 GMT

Reading Your E-mail

and you shouldn't post if you can't read.

I am aware of why they got the low frequency block, but not why the sort order came out with three nearest to the TV frequencies.

Posted Monday 4th March 2013 16:49 GMT

The Electron

Re: For those of us less technical.....

Opt for an LCD TV (not plasma!) with a DVB-T2 receiver and native 1920x1080 resolution, then you can receive High Definition - assuming your local transmitter is supporting it?!

There are a couple of ways you can experience interference, other than the usual blocking and pausing (my aerial is a mere 2.5km from Sandy Heath, which transmits 220kW, yet my TV and DVR still experience drop-outs!). If a 4G operator enables a tower (or builds a tower) that your aerial can see, the powerful signal (I say powerful - it's all relative to the power of your local TV transmitter(s)) may blind your receiver to the TV transmitter. Yagi aerials (used for TV) typically have a +/- 15 degree acceptance angle, so even if it is pointed dead-on to the TV transmitter, a nearby tower within the 'acceptance angle' could still cause a problem. Think of trying to look at a torch in the distance whilst some yob shines a laser in your eyes.

The other problem could come from a nearby 4G tower in your local area. As we are talking about milli-metric wavelengths (a quarter-wave at 800MHz is ~93mm), there is always the possibility of pick-up on the co-axial cable, or the aerial itself; even if it's pointing in the other direction.

Both of the problems above can be exacerbated by a wide-band aerial (possibly fitted to cover both analogue and digital transmissions) and/or an amplifier-splitter. Aerial amplifiers are often wide-band, covering Band II VHF (87.5 - 108.5MHz), Band III DAB (220 - 240MHz), and both Band IV and Band V TV (400 - 800MHz). A strong 4G signal could overload the amplifier and cause it to parasitically oscillate (poorly designed models can do that all of their own accord!). Result: no signal!

We have no real way of knowing if the 4G roll-out will affect few, or many. As Ofcom have no technical expertise, and have farmed out domestic radio and TV interference problems to the BBC, I am sure people are going to be left scratching their heads staring at a black mirror.

I hope you found this reasoned guidance?

Gary M0PLT

CBer and non-bearded Radio Amateur.

Posted Monday 4th March 2013 18:32 GMT

IHateWearingATie