Following the broadband money

Can DSL deliver 400Mbps over copper to the countryside?

with 46 comments

Br0kenTeleph0n3 has been looking for cheap alternatives for rural broadband, given that B4RN is looking at more than £1400 per home for fibre to the home (FTTH).

True, B4RN’s customers are going to receive 1Gbps symmetrical for £30/month, which may well tempt a move up north,. But then more by luck than good judgement we ran across a link to DSL Ring technology, which appears to offer some 400Mbps over copper, i.e. for free, or at least no extra cost, and for a claimed 1% of the cost of FTTH.

The xDSL attenuation problem

Source: Infineon: “Future Proof Telecommunications Networks with VDSL2” by Stephan Wimoesterer, Product Marketing Manager, VDSL2; July 2005.

It is well worth watching the video, especially for the graph (above) that shows that BT’s 80Mbps VDSL fibre to the cabinet service, to be introduced next year, suffers from severe attenuation problems. This means anyone living more than 1500 metres from the cabinet will get speeds equivalent to a brokeback donkey on Valium.

Also, DSL Rings doesn’t work on the BT network. Not for any technical reason, just that it is not yet approved for local access,

It is a mystery why BT CEO Ian Livingston hasn’t either licensed the technology or bought the company, if only to keep it off the market until it thinks we are capable of handling 400Mbps over the phonelines.

At any rate our curiosity was sufficiently piqued to ask the Canadian inventors, Genesis Technical Systems,  a couple of questions, the answers to which are below.

What is the present status of talks to get DSL Rings on to the UK ANFP (access network frequency plan)?

Genesis is a member of the NICC’s DSL Working Group and is submitting a proposal to the Carrier Steering Group to have work on DSL Rings-specific functionality included in the next work item.  Work items lead to a new issue of the ANFP.  Genesis has participated in drafting version 4i of the ANFP which is currently out for review.

 Where in the world is DSL Rings being used in pilots or even commercial applications?

Genesis has done entry lab demonstrations with both an Eastern and a Western European Telco.  Genesis is now planning further lab demonstrations and a field trial with a European Telco in the first half of 2012. Genesis anticipates commercialisation in the second half of 2012.

What is the average cost per household of providing up to 400Mbps access?

This is commercially sensitive information which is also highly volume-dependent. However, we estimate that the costs are less than 5% than that of FTTH deployments in urban areas, and less than 1% the cost of FTTH deployment in rural areas.

How well will this work in rural areas, where the distance between houses in often more than 150m?

Genesis’ DSL Rings is an excellent rural solution that provides telcos with a much needed opportunity to provide very low cost ultra-high bandwidth to their rural customers over distances even beyond 7 km from the exchange. The Genesis DSL Rings rural solution is specifically configured for networks with large distances between houses and a distance of more than 150 m does not generally affect its operation. The Genesis DSL Rings solution can provide rural telco customers with greater than 200m, and up-to 400 megabits/sec, over the telco’s existing copper phone lines at less than 1% of the cost of fibre (NB: Actual speeds depend on the availability of telco lines and equipment.)

What was BT’s response?

Genesis is not able to reveal information as to which telecoms in the UK and elsewhere in Western and Eastern Europe it is working with.

Which UK firms have signed up to sell or install DSL Ring technology?

Genesis is not able to reveal this information.

What patents protect the technology?

To-date Genesis has filed five patents covering various aspects of  its DSL Rings technology.


Written by Br0kenTeleph0n3

2011/08/22 at 21:06

46 Responses

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  1. will it work over rural aluminium and DACS, or will we have to lay new copper?
    If new copper is to be laid we may as well lay fibre.
    The phone lines in rural areas have been cut and patched so many times many can’t support even dial up.
    The same issue will apply if BT bought this DSL ring technology, they would only use it in urban areas where they could make a profit. They wouldn’t use it in rural ones. Also they are committed to their cabinets, and infinity.
    Again, even the slow cabinets won’t work in rural areas.
    The only hope is to JFDI ourselves. Like B4RN. gigabit or bust.


    2011/08/22 at 21:18

    • I am not saying FTTH isn’t the ideal solution, and I don;t know enough about this tech to be able to answer definitively. But they are claiming a rural roll-out would cost 1% of an FTTH roll-out, i.e. £14 vs £1400. If all we’ve got is BDUK’s £830m plus BT’s £2.5bn plus matching funds from Europe, RDPE etc, say another £2bn, and we want as many people as possible to get reliable high speed broadband (by hook or by crook) then we should look at all options (financial as well as technology) and make Genesis prove their claims.
      More importantly, the government needs to create the conditions where subscribers can get the best solution they can afford. They have dropped the broadband ball, so they need to leave the field, but not before they have stopped featherbedding BT’s shareholders.
      For the record, I think B4RN is a great initiative; I hope it works. If there is any justice in the world, it will.

      Ian Grant

      2011/08/23 at 08:12

    • There are “about 50,000” DACS installations, or were a few years ago. BT current policy AIUI is to spend up to £20,000 to remove one. They aren’t compatible with 21CN so will go eventually anyway. Source for 50,000 is OFCOM’s WLR charge review consultation comments & feedback. You’ll have to beleive me, or provide a better number with a reference 🙂


      2011/08/23 at 17:47

  2. Another well thought out comment, obviously won’t work over DACS, needs 2 pairs, not 0.5 to each property.


    2011/08/22 at 21:44

    • I am led to believe most homes have three pairs installed. It’s one of the reasons BT can push BET, so what’s your problem?

      Ian Grant

      2011/08/23 at 08:13

      • The dropwire to most homes is 2 pairs, but Cyberdoyle’s point is that in some locations there’s a shortage of pairs in the longer run E side cables so two homes may have one line each (using one pair in each dropwire) but that is fed from a DACS unit on the pole that itself connects to the exchange via a single pair.

        So Ian thinks there are 3 pairs per home, and Chris thinks there is less than one. Should be the basis for a logical discussion. Both are wrong.

        What would be interesting would be to dig out the BT bar chart that shows the distribution of line lengths from cabinets, which is in the public domain. It would also be interesting to know the number of DACS lines in the UK, nobody with ADSL has them and we should perhaps concentrate on the potentially large benefit to the many not get hung up on the relatively few that are left out.


        2011/08/23 at 15:57

      • Phil, if you know where that BT chart is, please post the link here, ditto the number of DACS lines.
        Regarding who benefits from high speed broadband, it would help everyone if BT published where it will not upgrade the network. Then those who want can use their own money to put in broadband systems that work for them.
        We should not use public money to help BT perpetuate and deepen the digital divide, as you suggest, but you obviously think that is OK..
        Of course, another solution is to move the 27% of the population who don’t care what’s on the net into the not-spots. That’d work, right?

        Ian Grant

        2011/08/23 at 16:38

      • ” it would help everyone if BT published where it will not upgrade the network” – including their competitors, which is a good reason not to do it. It’s also the sort of reason covered in the Treaty of Rome – though shalt not divide up a market, etc. TBH you have to be pretty dense to not know where BT aren’t going to invest. There’s at least 6 years evidence to work from.

        “We should not use public money to help BT perpetuate and deepen the digital divide” – so we should only use public money to provide exactly the same thing to everyone in some sort of communist Utopia ? I’m no fan of public intervention but I see no reason to differentiate between using it to upgrade someone from 4 to 40M or someone else from <2 to 4M if both have benefits and aren't mutually exclusive.


        2011/08/23 at 16:56

      • BT is not compelled to provide broadband anywhere. It can chose to compete where it wants. It is using its presence, due to its voice USO, to deter competitors from entering the broadband market. I would argue that’s unfair competition.
        Regarding the use of the money, the point is not to upgrade people from 4 to 40Mbps, but to provide access to people who now do not have any reasonable broadband access. Or just get out of the way and let them JFDI themselves. No harm in that, right?

        Ian Grant

        2011/08/23 at 17:24

      • “the point is not to upgrade people from 4 to 40Mbps, but to provide access to people who now do not have any reasonable broadband access”

        Perhaps we’re not talking about the same money. “BDUK’s goals include facilitating the delivery of universal broadband and stimulating private sector investment to deliver the best super-fast broadband network in Europe by 2015.” Seems to involve an awful lot uf upgrading people with a service to me.

        I don’t follow your argument that by having a USO phone service in place BT “deters competitors”. Where BT has failed to invest at Lyddington and Essendine it has been out-competed by Rutland Telecom deploying FTTC. Where it failed to invest at Ashby-de-la-Launde then NextGenUs walked off with the customers. Maybe we need more investors with guts and determination, and less hiding behind some notion that BT are preventing investment by merely existing and having a phone network.

        The few that want to JFDI can get on and do so, there’s absolutely nothing stopping them.


        2011/08/23 at 17:46

  3. We covered this several times last year on .

    It looks like an interesting solution and BT more recently told us that they did have plans to use a similar method, without specifically naming Genesis, in the future. The main problem for them wasn’t just that it would require two pairs but also the fact that such an upgrade would come at an additional cost, while the upgrade to 80Mbps next year is fairly easy/cheap to do.

    So whatever happens, it will be at least a couple more years before we see any real movement into next generation FTTC based delivery methods.

    Mark - ISPreview

    2011/08/23 at 06:24

    • Any upgrade will cost. The question is, why should BT spend £2.5bn putting in a VDSL system that is so badly affected by attenuation when there appears to be a better solution in terms of both speed and cost? Perhaps someone from BT, or BT’s advocates here, can answer that.

      Ian Grant

      2011/08/23 at 08:18

      • The video and graph is quite misleading, quoting the average distance *from the exchange* then using that to look at performance of VDSL2 which is of course deployed by BT *from the cabinet*.

        The video does go on to say that the distance from the “box on the street corner” to the house is “typically much less than 500 feet” (3m20s) in which case putting the VDSL kit in the street cab makes perfect sense.

        It goes on to say (4m20s) that the distance from house to house is generally less than 500 feet, which is not consistent with the above statement (unless you have a “box on the street corner” between every pair of houses).

        If houses are <100m apart you can put fibre to the first and wired ethernet between them in a similar manner, for any distance you can use fibre to daisy chain houses as the video describes. For intermediate distances you could daisy chain VDSL2 as proposed so there's no actual "technology" involved here at all – just an idea about using existing technologies.

        Looking at BT's FTTC deployment in a market town I see 44 street cabinets serving 20,000 people so the line lengths are not that long in the current FTTC investments. Each cab has up to 6 Gbit/s of fibre connectivity to the exchange. CIR is 20 Mbits/s per circuit or sync rate where lower. What BT are deploying is a cost effective "end of wire" solution that doesn't require major infrastructure investment and is likely to meet demands for a sensible equipment lifetime.


        2011/08/23 at 16:35

      • I think your last sentence gives you away, Phil. For you it’s all about the technology, not the customers, you old monopolist, you 😉

        Ian Grant

        2011/08/23 at 17:14

      • Well yes, I am a technologist – an Engineer in fact. I also like competition in markets.

        I like a technology that can at low cost deliver substantial broadband speed increase to customers. Why is that not to the benefit of customers ? What am I missing ?

        Would my village not benefit from FTTC putting 1 – 6 Gbits/s at the crossroads and giving everyone the option of 25-40M downloads and 4-10M uploads without any digging or other disruption and for a few quid a month more from a choice of retailers ?

        The committed CIR backhaul capacity of one FTTC cab is several times what B4RN plan to install initially. We should welcome all forms of improved service, whoever provides them. More bandwidth is always good.


        2011/08/23 at 17:56

      • I also like tech that delivers more for less. What I object to is the use of public money to deliver it to only some, and the use of privilege to deny it to those who are excluded but who are nevertheless prepared to pay an alternative supplier to deliver a service they want.
        “More bandwidth is always good.” Amen. Tell that to the ministers and the BT board.

        Ian Grant

        2011/08/23 at 22:21

  4. Thanks Ian for highlighting this anew.

    In another video Steve Cook, President and CTO announces that BT and Polish incumbent TPSA have both tested and verified the technology so I find his answers to some of your questions strange?

    I would have thought it should be fairly easy to determine which rural areas have the copper infrastructure / capacity that would support this last mile solution. These are most likely to be the same whitespots that will be last to get fibre to the home.


    2011/08/23 at 08:11

    • I don’t profess to know about all rural areas, but in Lancashire where I live there are thousands of homes on DACS, sharing a single copper pair, and engineers say they will have to run new copper just to get basic broadband to them, but the same engineers say it isn’t worth it because all they will get is less than half a meg anyway. If you bond two pairs for BET they will get a meg. It costs around £1k to do a BET I believe, some have said £900 and some £1400.


      2011/08/23 at 13:24

      • Given that copper prices make it expensive to buy and costly to replace when it is stolen, can someone please explain why BT isn’t installing fibre in all those empty ducts? If they could co-ordinate the thieves…

        Ian Grant

        2011/08/23 at 16:43

      • why isn’t there a Reply link on your reply Ian ?


        2011/08/23 at 16:50

      • I don’t know, but we seem to be managing, even if we seem talk past each other at times.

        Ian Grant

        2011/08/23 at 17:17

  5. The ANFP (frequency plan) currently doesn’t allow “reverse DSL” to avoid interference. This is in part because we have a competitive market and diverse suppliers in the same network.

    As an example, I am not allowed to put a DSLAM in my house on my end of a private rented circuit to another place because my downstream power would probably drown out next door’s ADSL signal from the exchange.

    Similarly if I did this DSL Rings thing in my house to serve someone 3 doors down but next door used Talk Talk FTTC or ADSL2+ then my VDSL output to 3 doors away could kill next door’s service as I would be shouting very loud in one ear while they were struggling to listen to a cabinet or exchange in the other.

    The ANFP is there for a reason 🙂


    2011/08/23 at 16:47

  6. BT is under a USO obligation to provide a telephony service, if someone steals the trunk copper cable it has to be replaced with copper to maintain the contracted services that people are currently enjoying.

    Isn’t it obvious ?


    2011/08/23 at 16:49

    • BT can’t do telephony on fibre? Does the USO specify copper or is it “technology agnostic”?

      Ian Grant

      2011/08/23 at 17:16

      • As of today BT don’t have a productised voice over fibre service, AFAIK. They are doing something on the FTTP greenfield pilot at Ebbsfleet. The USO could indeed be met by fibre (TPON did it, after all).

        My point really is that before the pikeys arrived there were a wide range of services from a number of providers going down a bunch of copper wires and these services were covered by contractual arrangements between various parties. At each end of the copper wires were bits of equipment and associated management systems.

        It’s a bit childish or ignorant to suggest that (overnight) all these services and contractual relationships should evaporate and be replaced by alternatives requiring new equipment at both ends. There’s the lead time for the equipment, if nothing else, and things like Redcare monitored alarms or ISDN lines to consider. How would the LLU providers react to being told “sorry lads, we had a cable theft so there’s now no LLU available but you can take our wholesale FTTx solution instead”.

        Perhaps it was a windup or a joke rather than a serious question.


        2011/08/23 at 18:12

      • It was meant lightly, but with serious intent. As Machiavelli notes, only a fool does not change when the circumstances around him change. Fibre ever closer to the home is inevitable due to technology changes and consequent demand changes and hence competitor changes. It may be prickly, but the sooner the UK as a whole, and BT in particular grasps this nettle, the better off subscribers will be in terms of service.

        Ian Grant

        2011/08/23 at 22:12

      • Consider the cost of replacing copper with fibre and the income available from the annual rental to do it. Difficult.

        Ian – do you understand the Redcars/ISDN issues?


        2011/08/24 at 08:29

      • I last looked at ISDN about 20 years ago. What’s your point?

        Ian Grant

        2011/08/24 at 10:32

      • That ripping out ‘copper’ and replacing with fibre is not so simple as it may seem.

        ISDN services are over copper, that has to be replaced by new kit. Copper cables in an area will combine together into larger ones so it’s a complex issue.

        USO means I can plug into a phone that works when the power goes off, and buy my service from many providers. With fibre there has to be a ‘white socket’ on the termination box and we need to know who replaces the batteries when they expire. What do Ofcom know about htis?


        2011/08/24 at 12:30

      • The thought occurs that perhaps the USO is obsolete. Why is it still relevant? What alternatives do we have? What effect would 100% mobile coverage have on the services provided by the USO? (Bear in mind that BT said I had to wait four weeks while it reconnected my line when I moved to a new house, and Post Office did it in two days.) Can we invent something to deliver uSO services that does not leave us dependent on an expensive, limited copper infrastructure?

        Ian Grant

        2011/08/24 at 12:43

      • USO gives an option of dependable telephony anywhere, probably more important at the fringes than in the mainstream.

        The USO is an obligation on BT (KCOM in Hull) to provide a fixed line telephony and functional internet access service (dialup) IIRC.

        Good to see the functional separation getting you an Openreach line faster via PO/Wholesale/Openreach than via BT Retail !


        2011/08/30 at 08:25

      • I was glad to get the Openreach/PO service, but I was happily surprised at the quality of mobile internet access I had from the 3 MiFi device, so much so that I am debating whether or not to cancel the landline. Now if I could just trust 3 not to cap my traffic…
        Since we are on USO, whatever happened to Openreach’s Fibre Voice Access product? I know it is only for FTTH customers, so probably not a priority, but still…

        Ian Grant

        2011/08/31 at 11:14

  7. Line length distributions can be found in a document at

    Executive summary –

    The most common total line lengths (exchange to property) are centred on 3 and 3.5km with about 12% of lines in each (lines grouped to 500m length bands).

    The most common D side (cabinet to property) line length is in the 200-400m band at ~32% of lines.
    About 93% of D side lines are below 1.5km. About 84% below 1km.

    I do have another graph, but there’s always someone off the end of any range limited technology so it’s somewhat academic whether it’s 1,2 or 5% you still need a policy for those you can’t reach.


    2011/08/23 at 19:11

    • Many thanks for posting the link to the line lengths assessments, Phil. I note that the figures are statistical models rather than actual measures. Can we assume they approximate reality?

      Ian Grant

      2011/08/23 at 22:00

      • The data is based on a paper presented to NICC DSLTG by John Cook which I haven’t researched. In the above doc it says that the John Cook paper “presents the cumulative distributions for BT’s network of line length for exchange to customer and cabinet to customer in the form of attenuations” – I would take this to be measured data, probably on a sample of lines or exchanges.

        The asses.pdf paper then converts the attenuation data back into line lengths for presentation in Fig 2 et seq. Of course it is the attenuation that matters to xDSL, not the line length per se.

        So I would disagree that they are “statistical models”, I think they are measured attenuation data turned into line lengths via some assumptions and then presented as distributions. Can we agree ? or is one of going to have to find and digest Cook’s paper ?

        (I did have another similar BT distribution of cabinet line lengths, which told a similar story – a lot of short lines and a very long thin tail of longer ones).


        2011/08/24 at 10:10

      • HI Phil – let’s agree, for the sake of the argument, that the sums are a close enough representation of reality that we can ignore the differences.
        Now, let’s address the issue raised in the Yorkshire Post, that urban SMEs are in danger of missing out on broadband ( Why would that be?

        Ian Grant

        2011/08/24 at 10:30

      • Urban premises may be covered by the BT 66%.


        2011/08/24 at 19:19

  8. Does the story have any credibility and substance, or is it just an envious cry over missed subsidy ?

    Leeds, Bradford and Wakefield – now let me see. All of those have cable, so that’s 50M download available. They are also competitive ADSL playgrounds with lots of LLU options.

    So what is their issue, and have they checked the Openreach FTTC rollout plan ?


    2011/08/24 at 12:27

    • The Openreach FTTC is opaque to say the least. It does not disclose which cabinets it will fibre up, not which lines from the cabinet, nor, within the 90 day slots, when it will happen, and even then Openreach has been know to change its mind without (much) notice.

      Ian Grant

      2011/08/24 at 12:46

      • Nit picking, to be honest – are the towns on the Openreach list or not ? What about cable – are there hundreds of urban SMEs that can’t get cable ? can they not get ADSL ? What bandwidth is available compared to what they need. What is their annual budget for connectivity. Have they tried EFM ?

        It’s such a vague story Ian I don’t see how we can address whatever issue it is they are concerned about.

        BDUK’s funding allocates money to white areas where they can subsidise, regardless of urban vs rural. Of course as the cities mentioned have cable they aren’t white areas so no subsidy.

        Data is in the public domain (accidentally) that shows postcode sectors served by cabinets and which are getting FTTC. ISPs have that info legitimately too, presumably updated. “Talk to your service provider”.


        2011/08/24 at 13:12

  9. Ian,

    back to your original point i.e. B4RN are seeking to persuade folks to invest the wrong side of a grand per connected home/business, so is there a better way?

    Well yes, that’s what NextGenUs does with FiWi that provides immediate fit-for-purpose service and a clear roadmap to FTTH over time given community demand.

    NextGenUs EXPERIENCE over the last decade informs the methodology and not a penny of taxpayers subsidy is involved either.

    Some further thoughts on B4RMY B4RN here –

    Guy Jarvis

    2011/08/25 at 00:17

    • ‘informs the methodology’ – Guy, what does that mean?


      2011/08/25 at 11:08

      • We will never know…


        2011/09/19 at 18:34

      • Is that because talks on getting the tech approved for local have failed, or because it has been tested and found wanting, or because vested interests are hell-bent on keeping it out of the UK?

        Ian Grant

        2011/09/19 at 22:06

  10. […] Br0kenTeleph0n3 has been looking for cheap alternatives for rural broadband, given that B4RN is looking at more than £1400 per home for fibre to the home (FTTH). True, B4RN's customers are going to…  […]

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