Documents show CAA fears over powerline networks
Minutes from Ofcom meet show BBC unhappy too
Both the BBC and the CAA are concerned that powerline networking will damage their services, though only one fears that it will lead to planes falling from the sky.
Earlier this month the UK regulator Ofcom hosted a meeting on the subject, minutes of which have been seen by the Reg. At that meeting PA Consulting presented its latest study into the risks associated with the use of power line networking (PLN) equipment. But the minutes show that the study came under attack from the BBC and the CAA, and that evidence was presented that PA's Proposals would lead to greater interference, not less.
The conclusion from PA Consulting's study that the problem will disappear through the magic of technology was gratefully received by Ofcom (which funded the study), but roundly rejected by many of those attending the meeting. The study itself was attacked for failing to consider high-density areas, such as tower blocks, for making assumptions about what level of interference is acceptable, and for being hugely optimistic about how effective mitigation techniques will prove to be.
The problem is that while powerline networking kit spews out radio signals on a wide range of frequencies, it's not considered broadcast equipment and therefore isn't subject to radio licensing. At the meeting Ofcom explained that even if PLN kit were causing interference, the regulator has no legal grounds to prevent its use.
The study concluded that sending networking signals over mains wiring presents a genuine risk to commercial radio, flight communications and even the next generation of ADSL, but that mitigation technologies could remove the problem if they could be imposed on manufacturers.
Few believe that manufacturers will put the technology into place without being forced to. Mitigation will make devices more expensive and there's little incentive for the end user to pay more, but for the moment that's a moot point as Ofcom has no ability to impose rules.
Ofcom has no official minutes of the meeting, but notes seen by The Register claim the CAA is seeking legal advice on preventing the use of PLN equipment, and has asked two airlines to help investigate the issue. We put that to the CAA, which confirmed its concern with both the possibility of interference and the lack of legal recourse should it occur.
According to the notes the BBC representative told the meeting that the corporation is already receiving complaints from World Service listeners suffering from interference generated by PLN kit. Given the demonstrable nature of the interference generated by high-speed PLN kit that seems likely, though we've not been able to confirm it with the BBC representative who attended the meeting.
Ofcom tells us that the number of complaints has declined lately, and that it's just a few radio hams kicking up a fuss anyway. The regulator also reminded us that it's not responsible for dealing with interference to broadcast radio or TV - that's within the BBC's remit these days.
So the responsibility now lies between two organisations, neither of which has the power to address the problem, and one of which is still expecting the magic of technology to make the whole thing disappear. Meanwhile manufacturers of PLN kit are already expanding into higher and lower frequencies, and seem likely to continue doing so until the interference issue becomes impossible to ignore. ®