Minutes of PLT Stakeholder Meeting August 3 2010

Nige Coleman made this Freedom of Information request to Office of Communications

This request has been closed to new correspondence from the public body. Contact us if you think it ought be re-opened.

Office of Communications did not have the information requested.

Dear Office of Communications,

Please can you supply the official minutes of the spectrum stakeholder meeting held on Tuesday 3 August 2010 at Riverside House involving the following entities:

Civil Aviation Authority
DG Enterprise & Industry
Richard Marshall Limited
Radio Society of Great Britain

If no official minutes from this meeting exist, how did Ofcom record any useful information arising from the meeting? Please provide this.

Where possible please provide Ofcom internal memos, emails and correspondence only which can offer an insight into the meeting and its results.

Yours faithfully,

Nige Coleman

Alexander Wyndham, Office of Communications

1 Attachment

Dear Coleman


Request for Information


Thank you for your request for information regarding Minutes of the PLT
Stakeholder Meeting (3 August 2010) which we received on Friday, 23 August
2013.  Please find our acknowledgement letter, attached.


Yours sincerely,


Alex Wyndham.



:: Alex Wyndham


   Spectrum Engineering & Enforcement (Spectrum Support)


:: Ofcom

   Riverside House

   2a Southwark Bridge Road

   London SE1 9HA

   020 7981 3000


show quoted sections

Alexander Wyndham, Office of Communications

1 Attachment

Dear Mr Coleman


FoI 1-241825564 - Full Response


Thank you for your request for information regarding minutes of the PLT
Stakeholder Meeting (3 August 2010).  We received this request on 23
August 2013 and I have processed it under the terms of the Freedom of
Information Act 2000.  Please find Ofcom’s response attached.


Yours sincerely,



Alex Wyndham.


:: Alex Wyndham


   Spectrum Engineering & Enforcement (Spectrum Support)


:: Ofcom

   Riverside House

   2a Southwark Bridge Road

   London SE1 9HA

   020 7981 3000



show quoted sections

Nige Coleman left an annotation ()

It should be noted that there is one participant noticeably absent from the list of attendees; Nigel Coleman. I was invited to and attended that meeting.

Nige Coleman left an annotation ()

With hindsight I should have pressed harder. Ofcom commissioned this meeting, which took place at Ofcom's head office, in a board or conference room. Senior Ofcom officials were present, the meeting dealt with a highly contentious topic of the illegality of in-house powerline networking.

It is beyond belief that Ofcom did not minute this meeting. How then were the attendees supposed to come away with a good command of all that transpired? Fortunately several of us at that meeting took detailed notes and we collaborated to produce our own round-up of the two sessions. As Ofcom are unable to provide this information, I will.

Attendees at the PA-Ofcom workshop, Ofcom question time PA were absent.

Mark Walls..........Ofcom - Head of Field ops
Andrew Reed........ Ofcom - Clive Corrie's boss
Philip Hogg........ Ofcom lawyer
Jill Ainscough......Ofcom COO
Graham Warren...... Ofcom - Head of Broadcast Technical Policy
Rod Wilkinson...... Ofcom - Licencing
Rhys Hurd.......... Ofcom
Gary Clemo..........Ofcom R&D
Clive Corrie........Ofcom - Enforcement Policy Advisor
Trevor Morsman......BT Labs Martlesham
Jonathan Lishawa....Comtrend MD, UK
Marcos Ostman...... Comtrend Engineering Director
John Pink.......... Amateur Radio
David Lewis........ UKQRM
Nigel Coleman...... Independent
Pablo Neira........ from the EU Commission, DG Enterprise & Industry
Peter Howick........EMC Directive Liaison
Richard Harris......EMC/RTTE Directive side of BIS
Cath Westcott...... BBC Overseas Services Directorate
Graham Plumb........BBC domestic services
John Mettrop........Civil Aviation Authority
Julian Lake........ PAC Report author
Peter Kirby........ RSGB
Richard Marshall....EMCIA
Dave Wilson........ RSGB President......
AWS EMC............ EMC Consultancy
Jonathan Stott......Consultant, sponsored by BBC
Don Beattie........ RSGB EMC Director
Alan Warner........ EMCIA

Notes commenced at 11.06, the Gill Ainscough COO offered a weak opening.

Phil White (PA) Opens for PA presentation on the report. Time scale of report, August 2009 - March 2010. Now will present broad conclusions of report followed by questions. Corrie affirms.

Julian Lake (PA) Project Manager of report presents report; summarises methodology, summarises conclusions.

"The UPA standard is the one we did most testing on because it is the one which is most common in the UK."
"Dynamic or Smart Notching is being experimented on and is coming in the next year."
"Firstly, all the HF services require notching." 11:26 BST
"We conclude that mitigation techniques do need to be implemented to avoid large-scale interference probability."
"Final point, we do recommend that measures are in place to ensure that these mitigation techniques are implemented to avoid the issue with large numbers of these legacy devices coming into the market without these features and existing in the populations for some time."
"Assumptions we were not 100% with, the filtering effect of the consumer unit, which is something we made key assumption on as far as conducted emissions go."

Phil White (PA) Comments. At the low frequency end (he means HF in context) PA found real evidence of interference. High frequency (VHF) was much more difficult to detect evidence of interference. Density modelling was quite low density. Were unable to model any flats or high density areas.

Corrie opens question time, 1/2 hour available.

Peter Howick (BIS) opened with a question regarding PA's usage scenarios, SmartGrid, PLT 100% coverage in UK population. BIS appeared to confuse BPL with PLT. PA responded with explanation of their statistical analysis, that 100% population of PLT would result in 3-5% increase in signal which is small compared to the reduction by mitigation techniques.

Don Beattie (RSGB) welcomed report confirms a baseline / starting point but take issue with a number of technical inconsistencies which affect the conclusions. Considers this report will become a document of record and asks Ofcom for a separate session with Ofcom / PA to thrash out the inconsistencies. Asks PA about Power Control, what percentage of devices would reduce power at launch, RSGB find PA's figure of 95% surprising on the basis that the mains supply is inherently noisy.

(PA). Didn't build this aspect into their model. DB retorts 'that's the concern'. PA cites 22dB power reduction comes from Koch report. Goes on to say that the device is assumed to work on a 100m range and at a lower distance there is less attenuation (he doesn't know the answer & waffles).

DB (RSGB) pursues original question by asking PA's assumption of the probability of any one device making a reduction in launch power as a result of dynamic power control as this fundamentally changes the conclusion's of the report.

PA, "What do you regard as significant?" DB(RSGB) enough to move it from 20% probability to 1%.(PA) haven't got those figures here & if another device next door, it can transmit without having to reduce the level of power. (DB), "if there is another device on the network or next door?" (PA) - "then that would play a part in the assumptions we took based on the Koch figures."

Jonathon Stott (ex-BBC now consultant) offers technical criticism of how PA arrived at its figures on probability of Power Control and on the shapes of the graphs relating to this. "I really can't take the idea of moving that over by 22dB at all."

PA - long pause, "That's a fair comment".

John Pink (amateur radio representative) "report uses word 'manageable', egress of PLT signal via power distribution network in house & out of the house is considerable, how would you consider that to be manageable? Plus in addition, egress of PLT signal out of telephone drop wires also considerable, how does PA consider that manageable?"

PA - VERY long pause. (15s) "You're quoting us as saying things we haven't said." Phil White (PA) hunts through his laptop. JP reiterates in different language. Further 6s pause, JP persists, further pause 6s. PA paddle around without making any sense. JP persists "So there are major sources of egress which are not covered in the report?" (PA) "We think it is covered" (JP), "Telephone wires?" (PA), "Well we modelled the mains networks". PA attempt to mitigate their omission by suggesting that it is not possible to model everything.

Civil Aviation Authority. Welcome the report, believe interference levels are very dependant on the assumptions made, need to verify assumptions. Find report worrying from aeronautical sector. One aspect of report fully disagreed is PA reference to 1% being infrequent, in aeronautical terms 0.1% is frequent. Systems such as landing systems are looked at in terms of safety as 0.000001% and above this mitigations are considered. Some of PA assumptions need to be confirmed. "From what I see here [report] some action is going to have to be taken, not sure what yet, asking airlines to start testing but action will have to be taken depending on the nature of assumptions." CAA then questions Power Control and requires clarification of assumptions.

PA: Whisper whisper; pregnant pause, no response to CAA. 10s pass, nil.

Richard Marshall (EMCIA). PA setting a great deal of faith in power control but compared to BT Comtrend, power control strategy as presently drafted has power control going upwards as well as downwards and places the BT Comtrend emissions level at the centre of the range. "You are not going to get much, if any statistical benefit from Power control and in fact there will be as much as a 15dB increase from power control over long distances. "

PA, "Is that a recent development?" RM, "the latest." PA acknowledged it would make a difference to probabilities.

Richard Marshall states that he agrees the RSGB's position that there needs to be further technical discussion of these points.

PA paddle about for 1/2 minute with no effective response. RM criticises the exchange of dBuV/Hz > dBm/9kHz.

PA paddle about further 30s, acknowledging that anything reducing the effectiveness of the mitigation would affect the report.

Graham Plumb (BBC) calls into question the PA assumptions on worst-case, suggesting that this more closely represents average radio equipment scenarios.

PA responds with 'report is general statistic, there will always be situations where it doesn't apply.

BBC is concerned that its listeners don't know how to mitigate interference when they suffer from it.

JP suggests they call Ofcom. LOL.

PA suggests that listeners should get a better antenna system…

David Lewis (UKQRM). PA sets much store by Smart Notching, how can it measure noise floor when there are other PLT's already polluting?

PA - Long pause, whisper, whisper, (15s), "What would you suggest???"

UKQRM, Notch broadcast, IARU & aeronautical bands. Smart notching cannot work.

PA. Long pause (30s) "So the noise floor becomes higher?"

Jonathon Stott (BBC) interjects. States that original specification required all PLT to pause synchronously to measure noise floor or else it is not measuring anything meaningful but this has disappeared from the spec.

UKQRM to PA, "What does this do to your conclusions on smart notching?"

PA, Does not think it changes their conclusion that smart notching is needed. The report's point was not to validate smart notching, just that it was needed.


Session 2.

Ofcom open. Invite questions.

DB (RSGB) Not quite sure what the state of the report is regarding Ofcom, Ofcom commissioned it, published it, do you accept it? Corrie refuses to answer and passes to Gary Clemo. Ofcom largely accept the report at a technical level but offer no regulatory comment.

DB states report confirms that current generation of PLT cause interference, that they require modification to be anywhere near an acceptable level of interference, why has Ofcom held back from taking action against them? Does Ofcom now accept these fail to meet the Essential Requirements?

Corrie. Obfuscated with statement regarding level of interference reports, 2009/10 down by 1/3 on previous year. In relation to number of units deployed this is significant. Stance on enforcement is unchanged from published statement. Ofcom is evidence based regulator. It will only take action based on evidence. PA report does not address or reflect on Ofcom's position on enforcement.

DB (RSGB) clarifies question. RSGB has been asking Ofcom to provide regulations under S54 WTA to address problem because Ofcom has no powers to enforce. Is Ofcom going to put in place powers to enforce?

Corrie. "We didn't say we didn't take enforcement because we didn't have the powers, we didn't take enforcement AND we don't have the powers". Looking at question of introduction of powers, Ofcom has 6 statutory instruments it can use to take action. There is a gap and Ofcom cannot take action against this category of apparatus.Ofcom is looking at measures to enable them to take action but this does not mean they would use them and is likely the measures would only be for situations where there is a danger.

DB(RSGB) States that if he were a regulator he would want to know that if there was a problem, he would want powers to act should a problem exist.

Pablo Neira (DG Enterprise) reinforces Ofcom's position of not taking regulatory action for every complaint of interference; someone might complain about atmospheric conditions (his words, not mine). Reinforces freedom of movement of goods, CENELEC has taken over responsibility of Standards.

DB (RSGB) reinforces his point that a regulator must have the power to act when the need arises and the RSGB is surprised and concerned that Ofcom do not.

CAA acknowledges that it is not unreasonable to have interference if it can be resolved. Worried about VHF landing systems, aviation want to avoid the situation before it happens, CAA are concerned that products getting into the market, how can the UK move forward to make sure it has powers to take action against a polluter, how can this be put into Standards? CAA's lawyers are looking at what legislation they have to take action against a PLT polluter. CAA want the Standards to make sure that manufacturers don't usurp the Standards.

Ofcom welcomes CAA input and interference report. So far only radio amateurs and SWL have complained. Ofcom has corresponded with manufacturers who welcome Standards. BT have expressed their desire to only use equipment which adheres to the Harmonised Standards. "Production of a standard will be a benchmark to judge everyone by."

(DL, UKQRM). Power is set by software, nothing to stop higher power by firmware change & 'aftermarket' 'turbo-charging'. Manufacturers in competition, anyone can make a product on any frequency at any power provided products have certification, they can be shipped.

Jonathan Lishawa (Comtrend UK MD). Welcome report, productive meeting, welcome dialogue with Stakeholders. Claimed to be responsible. Test against latest Standards. Want to build in mitigation that can 'realistically' be done. Product stops at 30 MHz. Would not want to interfere with any legitimate user of radio spectrum. Would not want to see his products interfere with aeronautical. "We are not all going to get what we want. If I can develop a future product which doesn't cause interference to any Stakeholder, that's good for my product. We have an obligation to be responsible in the UK market."

DL (UKQRM) In order to be responsible, are you prepared to start shipping products with the broadcast bands notched?

JL, Comtrend, "I think we need to discuss that."

DL (UKQRM) But surely being responsible means you do notch the broadcast bands?

Comtrend, "As of yet I'm unaware of any complaints out of the community that's here. Maybe you can provide visibility on that or documented cases of radio users who, with our technology, a Comtrend product, are experiencing interference.

Nigel Coleman (RAOTA) "Well I am one! I've been prevented from using the radio for 6 months on certain bands because of a Comtrend device."

Corrie intervenes, he knows exactly where this can lead. Corrie asks NC if he has a question?

NC (RAOTA) PA report states Ofcom have observed significant noise levels up to 300m from PLT installations, how does Ofcom reconcile this with the Class B limit which is 10m?

Ofcom: long pause (8s) "We don't have to reconcile." Corrie quotes Essential Requirements and continues, "So that's not the essential Requirements that you've just quoted."

NC (RAOTA). EN55022 protection limit is used to declare conformity against Essential Requirements, if device is radiating 300m but protection limit is 10m, how can that device not breach the Essential Requirements?

Corrie. Quotes the blue guide. Failing the Harmonised Standards doesn't mean the Essential Requirements are breached. The EMC regime is a legal regime not a technical one and the Harmonised Standards are voluntary.

NC (RAOTA) quotes para.2, 2004/108/EC and adds that he has evidence and Ofcom has evidence - 226 cases according to NC's FOIA, of people experiencing a breach of the essential Requirements!

Corrie. The Essential Requirements refer to one piece of apparatus placed on the market by one manufacturer and Ofcom enforce the EMC Regulations. Our stance is set out in our public statement.

JP (RSGB). "If in the next few days the IEC mark CD257 as invalid, what will Ofcom's position be?"

Corrie. "We are not involved in Standards, we enforce against the Essential Requirements & not against the Standards."

JP. There are a number of devices with certification based on meeting the requirements of CD257, what would Ofcom's position be?

Corrie. You are talking about the DoC. Manufacturer is entitled to use the compliance process of their choice. It is an administrative and technical process which allows them to place a product on the market. Ofcom as a Market Surveillance Authority will enforce against the Essential Requirements. "We are required by the EMC Regulations to enforce when there is a spectrum management or pollution issue. So that is a matter Trading Standards might be interested in, in enforcing the Essential Requirements."

Pablo Neira (DG Enterprise) reinforces that failing harmonised Standards does not automatically mean breaching Essential Requirements.

BT state that the interference doesn't come from the device, it comes from the wiring, has there been any work done to determine the RF characteristics of UK wiring stock? It is not the equipment that is at issue, it is the wiring.

Richard Marshall. (EMCIA). Have read everything in the last 12 years & found nothing on the emission characteristics of UK house wiring. PMT makes our wiring more unbalanced & more of an issue.

JP. Submitted a paper to CISPR/I PLT project team two years ago detailing systematic analysis he had done on the RF emission characteristics of his house mains. It is published.

BT. Would welcome if Ofcom had powers to deal with interference. BT have had nearly 400 cases of interference to broadband since December. BT often cannot get anything done about the interference.

Richard Marshall. Complaints. Present system doesn't positively encourage complaints. As far as PLT is concerned there is nothing in the nature of the interference which allows the man on the street to realise he is suffering interference and can do something about it. Believes the specifics of a few hundred cases are the tip of the iceberg. Ofcom's PLT complaints now exceed any other cause so they are not negligible. Other aspect of complaints is that the level will be low until the problem is so bad that irreparable damage has been done to the EMC environment. CAA won't get significant complaints until there are huge ground populations of PLT. Won't know which PLA is causing the interference because when they are all summed up, won't be able to distinguish from a few devices. "For cumulative interference, there can be no question of waiting for evidence, you have to rely on the laws of physics and take action now."

JP. Ofcom is comparatively blind and comparatively deaf. Ofcom works from evidence, JP likes this but uses Plasma interference as example. Ofcom have 12-15 cases JP has over 125 from a simple survey. Ofcom is blind & deaf.

Corrie. You [i.e.JP] have some evidence of this high figure, Ofcom's figure is from reports made to it. (Corrie)” You haven't asked for any details.” (JP)"Of course I have.” (Corrie) “You have? Well it's very unusual that they haven't been reported to Ofcom.”

JP. Very common comments in that list of 125; "I didn't want to incur any costs" or "I didn't want to upset my neighbour." Doesn't make the complaints of interference any less valid." Agree with proportionality but we have to get Ofcom to have better eyes and better ears.

Corrie. We are an evidence based organisation. We can't work on conjecture.

RM (EMCIA)." You cannot be evidence based on the question of cumulative effects, it simply won't work."

Corrie defers to the lawyer. (Philip Hogg)." We understand the point but the legal regime is what it is." Freedom of movement of goods by treaty in Europe. If we find a product doesn't meet the Essential Requirements we can use criminal law or sanctions but requires a burden of proof. A slight increase in noise for others doesn't trigger a criminal investigation, I think that's why we have a mismatch here. We understand your concerns.

RM. "No, you have changed the rules; you can't cope."

Corrie. Stops thread and pushes to Cath Westcott (BBC World Service).

CW (BBC). We still have a significant audience on shortwave and once of our difficulties is we still expect our programs to be heard wherever we send our programs to, like China and we would expect those programs to not be interfered with. My difficulty is (to Ofcom) if you are not getting many complaints, it doesn't mean that no one is listening, how would an ordinary listener with reception problems on shortwave go about reporting the problem?

Corrie. "We do have a reporting mechanism where people can report interference to us, there is wealth of information on the internet about shortwave interference, there's been a No.10 petition we are sure that your listeners wishing to listen to transmissions from outside the UK would be able to find something. That's the extent of it. But again we don't have a single report" - BBC interjects, "We have".

Gill Ainscough(Ofcom COO) perhaps you have but you handle complaints - BBC interjects, "Apparently we aren't responsible for shortwave". As far as she is aware Ofcom are still responsible for shortwave.

GA. I think this is something that will come out in the wash during this transfer of responsibilities.

RSGB. The user friendliness of the Ofcom website is very bad. Person called RSGB recently regarding licensing, had been told to call RSGB by Ofcom call centre (to rectify problem with Ofcom licensing website). Is the Ofcom website "ethnic friendly" is it in languages other than English?

GA. No it's something we are working on at the moment. She is concerned at the call centre issue.

RSGB. 40% of all the calls we get on a daily basis are referred to us by the Ofcom call centre.

RM." Will Ofcom organise a meeting to review the technical details of the Ofcom report?"

Gary Clemo (Ofcom). We need to have a discussion about this. As far as PA are concerned they have finished their report so we would be relying on their good will.

DB (RSGB). Can we send our comments to you?

GC (Ofcom) I'd much rather you sent them to me.

Corrie. Closes the meeting stating that Ofcom are liaising with manufacturers but this is a complex issue for them but Ofcom is looking to move forward with this.