PLT chair: UK Radio Society is 'living in a dream world'

The chair of the EU committee on powerline networking has responded to the Radio Society's call to arms, claiming that every minute of filibustering pollutes the radio spectrum more.

The Radio Society of Great Britain reckons the new standard, prEN 50561‐1, will water down existing requirements, opening the way to greater spectrum pollution, and has asked members to lobby their local representatives. But Ronald Storrs, Chair of the committee defining the standard refutes that, claiming it’s the RSGB who are risking the airwaves with their pointless protests and inflexible attitude.

The problem is that sending data signals over unshielded mains wiring, as powerline kit does, generates radio interference, and as the manufacturers push to increase speeds that interference is spreading into the frequencies used by the rest of us.

That, says the RSGB, is unacceptable, as EN55022 (to which all kit bearing the CE mark must conform) requires that devices don't generate significant interference. But, say the device manufacturers, our kit isn't generating the interference, the mains wiring is, and in many homes the wiring is sufficiently shielded that no interference is generated anyway, so we'll continue to sell our devices legally.

Those manufacturers have survived several legal challenges, and in the UK Ofcom has taken a backseat, saying it can't do anything as the devices themselves aren't radio transmitters so fall outside their remit. Ofcom says it's waiting for prEN 50561‐1, which will apply to powerline tech, but it's been waiting some time on that score.

Ronald Storrs agrees that PLT kit is generating unacceptable interference, but reckons that every day there isn't an applicable standard more unrestricted kit is getting into the marketplace, and the intransigence of UK radio hams isn't helping:

"Today's equipment has no restrictions" he told us, "so bad as it might be [prEN 50561‐1] is a huge improvement".

Storrs reckons having a standard in place also means it can be tweaked later, but having no standard means nothing can be done. Once passed 50561 requires devices to reduce their transmissions to the minimum needed, as well as switching off when no data is passing over the network. It also requires PLT kit to be "notched" to avoid using frequencies which have been identified as protected – and to detect and avoid busy bands dynamically.

Dynamic notching is complicated, and the RSGB has argued in the past that it often fails, even static notching has been shown ineffective as it is often poorly implemented and signals stray from where they should be. But while the RSGB argues that this proves notching is pointless, Storrs contends that once notching is part of the standard, then poor implementations can be addressed and rectified – but until then the manufacturers have a free hand.

Which is why, according to Storrs, the PLT manufacturers have been dead set against the standard, and why it has the support of the International Amateur Radio Union - which leaves the UK hams standing alone against the EU.

PLT kit does generate interference, enough to worry the BBC, the CAA and the Spooks, but what to do about that is more difficult to say.

The RSGB calls for an outright ban, claiming that such devices breach EN55022, but that approach hasn't worked so far. If Storrs gets his way, then by the end of October we could have a new standard for PLT kit – one which can be enforced even if it's not as draconian as some would like. ®