No Threat to Radio Spectrum say OFCOM
old pilot
Posts: 1,910 Forum Member
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During the last year there has been a long running thread on here suggesting broadcast radio will suffer major interferance from PLT's used for home entertainment and communication.
The last thread on this issue was pretty heated at times but centred on amateur radio enthusiasts campaigning for the banning of the technology on the grounds that PLT's would cause major disruption to mainstream broadcasting.
Below are a couple of links to the main campaigners arguments (John Petters and the Radio Society of Great Britain.)
The conclusion from the EU and OFCOM is that the use of PLT/Homeplug technology does not pose a risk to mainstream radio broadcasting and that any small problems have been or are being resolved.
Here is the reply from OFCOM's Clive Corrie to John Petters video's on Youtube suggesting homeplug/plt's and diatribe on this forum suggesting PLT's will destroy the radio spectrum
http://www.traditional-jazz.com/mainpages/documents/ReplytoPettersemail04October2010.pdf
http://www.traditional-jazz.com/mainpages/hamprojects.htm
http://www.rsgb.org/emc/docs/pdf/EC%20reply%201%20September.pdf
The last thread on this issue was pretty heated at times but centred on amateur radio enthusiasts campaigning for the banning of the technology on the grounds that PLT's would cause major disruption to mainstream broadcasting.
Below are a couple of links to the main campaigners arguments (John Petters and the Radio Society of Great Britain.)
The conclusion from the EU and OFCOM is that the use of PLT/Homeplug technology does not pose a risk to mainstream radio broadcasting and that any small problems have been or are being resolved.
Here is the reply from OFCOM's Clive Corrie to John Petters video's on Youtube suggesting homeplug/plt's and diatribe on this forum suggesting PLT's will destroy the radio spectrum
I understand some of the objectives, however I fail to see that the experiments show the type of installation intended or indeed reasonably expected by the manufacturer. For example, the use of electrical wiring to form an antenna by winding it around a garden fence and spanning to and up a metal mast (which might of itself have a conductive effect) certainly would not in our view be something that would be expected under the likely intended use. This product is intended for use in a domestic or small business environment to facilitate connectivity within a single network. I would reiterate Ofcom’s view that using PLT apparatus as intended by, and in accordance with the manufacturer’s instructions does not amount to wireless telegraphy. In arriving at this conclusion I fully acknowledge your representations relating to the wording contained in the Wireless Telegraphy Act 2006. Transmission through the electrical wires in a home is not “wireless” transmission in our view. Having delivered a response to this element of your query, clearly the matter of licensing becomes redundant. I have endeavoured to respond accurately and in a timely manner to your many e-mails on this matter and I now consider this issue closed.
http://www.traditional-jazz.com/mainpages/documents/ReplytoPettersemail04October2010.pdf
http://www.traditional-jazz.com/mainpages/hamprojects.htm
http://www.rsgb.org/emc/docs/pdf/EC%20reply%201%20September.pdf
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Comments
Remember there could be someone with PLTs reading this message and it then being picked up thousands of miles away and being decrypted...
I wonder why it was neccessary to wind electrical cable around a garden fence and up a metal mast to try and achieve results?
The average house contains relativly short lenths of cable radiating from the consumer unit.
The EU have also stated pretty bluntly that homeplug technology is here to stay.
As for OFCOM Clive Corrie has said the matter is closed.
I realise that most PLTs will not cause significant interference to strong network radio unless they are quite close (next door perhaps), but to dismiss them as 'no threat' is rather glib.
Because commercially, OFCOM have no balls and are slaves to the big corporates.
I agree they can be annoying for short wave enthusiasts Andy but BT have been very helpful in changing units in such circumstances. It might be worth a chat with the neighbour to see if they have a BT set-up.
The problem was solved months ago by inviting my neighbour into my home to witness the racket for himself. He was horrified and luckily he was in a position to install CAT 5 instead.
And don't forget there are many cases of Ofcom simply closing a case without solving it. It's not a good situation, and far from being 'not significant'.
This is the situation I am in. Ofcom say they have no enforcement powers when it comes to interference caused by PLT devices. The BT devices are being replaced by BT, not Ofcom. Those of us who suffer interference from non-BT privately purchased devices have no protection. I seem to remember this was also mentioned several times on the other thread. Here we go again?
Pop
But I'm already a keen walker and spend many hours out of the house. When I get back home I want to do a spot of radio listening and I can't, all because of this poorly thought-out technology which exceeds the emissions specs.
The belkins hd plt have been known to goto upto 370mhz now if I lived in a house near the coast and useing plt wiped out the coast gard radio would I be to blame if some one dies because the coast gard cannot hear the radio call due to the interference ?
To be fair, I think it is true that OFCOM have decided at a high level that computer networks are the future and sub-30MHz broadcasting is the past, largely because the first is profitable and the second is not. They can't formally reallocate SW and MW to computer networking (international agreements, licences paid for etc), but the statement makes very clear that is what the reality is.
The main hope is that OFCOM might reconsider this decision if "second generation" devices which wipe out both FM and DAB reception in large numbers of neighbouring houses become widely distributed. Past experience suggests Radio 4 listeners are hard to ignore, even if it would be profitable to do so.
Plus, since all PLTs operate on the same frequencies, it's worth pointing out that if everyone used them, they wouldn't work at all, since they would interfere with each other (much more so than Wi-Fi which at least has a choice of channels available).
In the long term it's not a sustainable technology, and consumers will look elsewhere...
The cable was wrapped around the fence - to support it off the ground!! What else?? The cable was attached to the tower to support the other end! What else??
House wiring, as stated, is a mish-mash of assorted pseudo-random lengths of wire, and the experiment was a minimalistic representation of this. A later experiment had an assortment of different spurs off the main extension, to better represent the domestic mess.
Different lengths of wire are rf resonant at different frequencies, simple physics prove this. Then, when someone stuffs an extension lead into a socket, whether it be 1 metre for a kettle, or 60 metres for a garden tool, somewhere in said house, they change the frequency that that particular length resonates at.
Therefore each house will resonate at a different plt frequency. Some may be innocuous, IF nobody happens to be listening to a radio nearby, while others, as has been proved repeatedly, will wipe out all communications for up to half a mile.
BT are not allowed to replace non-BT plt units, the owner has to be persuaded, and OFCOM don't have the balls to do it, because it is suspected that they have been told to shut up by BIG BUSINESS, ie the PLT manufacturers. The RSGB cannot force OFCOM, any more than a flea can change the course of a whale. :mad:
I opened the thread because on searching an unrelated matter with OFCOM (Expenses Rhodri Williams of £21 248 £28 186 £10 703) http://www.whatdotheyknow.com/body/ofcom
I discovered the matter was far from over despite the letter from Clive Corrie which was never in the original thread.He never got a chance to defend himself on this board.
There appears to be a proper well organised campaign to resolve the issue conducted by the RSGB while others persue a private mandate.Two new FOI demands to OFCOM were published just before Christmas.
There is interesting reading on the RSGB website.
Simon Hicks, Head of Electronic Communications Technology Information Economy Directorate at the Dept for Business,Innovation and skills wrote the following to the RSGB on December 10th 2010.
http://www.rsgb.org/emc/docs/pdf/RSGB_PLT_DEC_BIS_Letterhead.pdf
There is no victory dance to be had by either side - the same ridiculous situation is true now as it was three years ago, only more spectrum is being taken by PLT.
So your view is very much a "not in my back yard" - ie sacrifice HF, but protect DAB and FM? What about VHF airband, PMR radio etc?
Who are you referring to by saying "The main hope is that OFCOM might reconsider this decision if "second generation" devices which wipe out both FM and DAB...."? Your own hope I assume? Who do you have to represent your claim to access spectrum without undue interference as laid down in the EMC regs? A third party or are you relying on Ofcom?
Computer networks do not need to use mains wiring. I could argue the case against PLT from a green perspective when a simple cable can do a better job.
People seem happy to have choice taken away from them. Your point about the Radio 4 audience being " hard to ignore" is an interesting one - where is the wailing and gnashing of teeth about analogue FM switchoff from the R4 listeners? I can't hear it. Maybe they don't care or won't care until the radio in the car doesn't work one morning?
You are probably quite right in PLT not being a sustainable technology, but what about the damage that has been done to spectrum during the time that it has existed?
I am not prepared to get drawn into the argument on this thread. The topic has been discussed many times on DS with no reasoned outcome.
73 Richard
After my previous run-in with a pair of these things, I thought I might be free of their dreadful racket for a while. But no - it looks like someone around here has got a pair for Chritmas, and once again my SW listening is ruined by the familiar screeching noise.
Audible from about 4 MHz to 26 Mhz, it reaches a broad peak around 8 MHz.
This time the noise is 'only' S9, 20dB less than last time, but it's easily strong enough to mask all but the strongest of international BC stations.
Looks like I'll be out with my radio soon, doing a spot of blood-hounding.:mad:
http://www.ispreview.co.uk/story/2010/12/31/liverpool-uk-to-trial-200mbps-powerline-communications-broadband-technology.html
Liverpool UK to Trial 200Mbps Powerline Communications Broadband Technology
That's going a bit far - they are not deliberately setting out to trash analogue radio. It's an unfortunately side effect.
A child could see that a PLT causes interference. They seem to be sticking to this patently nonsensical claim that the interference is "insignificant" because they favour PLT usage of the old AM bands on commercial grounds (or at least are either too friendly with or too scared of the companies selling PLTs to take action).
I don't think PLT will be banned until sufficiently large numbers of people (and the sort of people capable of making a high profile fuss) get upset by it. If reckless damage to Radio 4 (or a few other high profile things like the air band as you suggest) can be demonstrated and publicised, I would say that PLT is toast.
"I now consider this matter closed"!!! Well he might consider it closed but all those people trying to listen to the radio next to one of these PLTs certainly will not!!!!
That email you recieved is typical of Ofcoms head in the sand, finger in ears saying lalala, hoping it will go away attitude. What an utterly useless organisation they are.
It also has the first basic 200Mb/s Powerline HomePlug integrated into a router's mains adaptor, so only one remote homeplug is needed.(up to 30Mhz)!
But also has WiFi!
http://www.reghardware.com/2011/01/05/ces_netgear_powerline/