Original URL: http://www.theregister.co.uk/2013/04/18/at800_mailing/

Londoners in mass test of telly tech savvy as 4G filters mailed out

Come on granny, you must know where your booster is?

By Bill Ray

Posted in Media, 18th April 2013 07:43 GMT

Some 28,000 London suburbanites will have 40 days to fit their free 4G filters, before Freeview television frequencies are swamped with faked 4G networking signals in a mass test of the British public's ability to plug stuff in.

The filters come from at800, the orgainisation tasked with spending £180m of telco cash to mitigate against the expected interference from 4G networks expected to be switched on come the summer. Previous testing has involved measuring the level of interference: this time the intention is to see if the public is capable of plugging in free filters sent out by post prior to 4G switch on.

The filters are needed because the new 4G networks run at 800MHz, in spectrum formerly used by analogue TV and thus picked up by Freeview TVs and set-top boxes. Interference is only expected where amplifiers (signal boosters) have been fitted, but as no-one knows how many amplifiers are in use and the filters have been pre-ordered in bulk by at800 the plan is to shotgun them out to the public and hope for the best.

The first round of testing showed much less interference than expected, which is good as shotgunning filters won't work anyway - the average UK household contains 2.27 televisions (viewed by 2.35 people) and while only 37 per cent of primary sets are using Freeview the vast majority of the remaining 1.27 TVs are reliant on free-to-air digital TV which is vulnerable to 4G interference.

But most of those sets aren't using amplifiers, so the filters which at800 will be posting out, and many residents will be busy plugging in, will be irrelevant in the majority of cases, though (critically) no-one knows how large a majority. at800 isn't going to complicate matters by asking people if they have an amplifier, just explaining that the unpowered pack-of-cards filter "simply connects between an existing aerial cable and television, or Freeview box" adding that "If viewers have an amplifier or signal booster the filter needs to be connected between the antenna and the amplifier."

How many people won't know they're using an amplifier - or won't be able to access the wire between it and the antenna - no-one knows, which is the point of the testing. Another good question is how many of the 28,000 bits of electronics being posted out over the next week will end up in bureau draws or pointlessly connected to interference-free wiring, and that's something we'll probably never know. ®