Cellular repeaters: Can you hear me now?

Operating or installing an unlicensed radio transmitter can get you a year in chokey, or six months if you're lucky enough to be in Scotland, and El Reg would never condone such activity - so please enjoy the following work of speculative fiction.

A cellular repeater is a base station, but one whose only connection to the rest of the cellular network is over that network. They are normally installed, by network operators, in places with weak coverage where a yagi antenna pointed in the right direction can pick up a good signal; that connection is then used to provide connectivity to nearby handsets using a microcell base station. But these days cellular repeaters aren't just being deployed by network operators, despite the legal ambiguity within which they exist.

Cell Antenna, the company so effectively pushing to fit jammers in prisons on both sides of the pond, will happily sell you a cellular repeater in the UK. The company has been supplying them to US punters for years, where they are legal, but on this side of the pond Ofcom's guidelines leave little apparent room for doubt:

Installation or use of repeater devices by anyone without a licence is a criminal offence under Section 35 of the WT Act 2006. Any person found guilty of installing or using such devices without a licence would be liable on conviction to a fine of up to £5000 and/or up to 51 weeks’ imprisonment (Six months in Scotland and Northern Ireland).

...but we'll come back to that later. Initially, let's imagine you are one of the 45 per cent of home workers, or 30 per cent of office workers, whose mobile coverage is limited to near windows or the far left corner of the car park - then a cellular repeater would be just what you need, if they were legal. A basic repeater will set you back just short of £400, and you can't expect any operator subsidy on that.

The kit comes in an array of boxes - ours lacked instructions of any kind, but even without them connecting the bits together isn't complicated. The yagi looks a small TV aerial and is supposed to be pointed at the nearest base station (Google Maps can help here), though we didn't find that necessary: it is happier outside, though, and comes with a decent length of cable for fitting. That connects to a mains-powered booster, about the size of a couple of cigarette packets taped together, which in turn connects to a microcell antenna about the size of a hardback book.

The microcell is designed for wall mounting, and covered in the kind of white plastic that would render it instantly invisible in just about any office environment. Cellular repeaters are frequency-based: so generally only work with a single network operator - ours was configured for use with Vodafone.

Once plugged in the only indication that anything is happening is a green light on the booster, alongside a second light labelled "alarm" that only comes on when things aren't working. Within seconds of being switched on every Vodafone handset in the area reported a full-strength signal, and were able to make and receive calls without difficulty - even from locations that had previously been completely lacking in coverage.

Switching off the power resulted in the signal disappearing, though oddly calls that were already in progress were maintained as the handset was able to switch to a previously-unseen base station for continuing an already-established connection.

Given the utility of the repeater it's a shame you're not legally allowed to use one, though Cell Antenna maintain that if anyone at your network operator tells you it's OK; even the prole on the helpdesk, then you are legally fine as the licence holder has given you permission. We contacted all the network operators, as well as Ofcom, to seek an opinion.

3 said it had never really given the matter much thought, while T-Mobile said it planned to make such technology redundant by offering its customers Femtocells instead. The rest said they would look into it and let us know - so perhaps they're still forming opinions.

What we do know is that no one has ever been arrested, or charged, for using or installing a cellular repeater, and until the boys in blue come knocking at Vulture Towers we'll be able to hear you fine. ®