Long Reach VDSL trial in Isle of Lewis

I see 20 houses on North Tolsta on the Isle of Lewis have been selected for the trial of Long Reach VDSL.


http://www.ispreview.co.uk/index.php/2016/08/openrea...

http://www.islandnewsandadvertiser.co.uk/lewis-test-...

Edited by Nightglow (Thu 18-Aug-16 16:07:42)

Does anyone have any idea on when LR-VDSL will become a widespread solution to long-distance copper connections? Is it just a simple firmware upgrade to the cabinet, or does it require a sophisticated hardware extension like G.fast?

Should be software or at worst a new line card in an existing DSLAM. So less onerous that original VDSL roll-out.

As for widespread - issues around co-existence with ADSL/ADSL2+ signals are a key thing hence the variations in analysis of the effect at http://www.thinkbroadband.com/news/7499-what-will-lr...

The biggest restriction to widespread availability is that it needs regulatory approval.

The technical solution is incompatible with exchange-based ADSL or ADSL2+ services, whether from BTW or LLUs. The solution is to swap all subscribers, of all ISPs) onto a GEA product ... and you can imagine how well that will go down - especially with Sky and TalkTalk.

Ofcom will need to decide whether LLU takes precedence over long-range customers ... and will probably need to set up a scheme where this gets approved on a cabinet-by-cabinet basis.

When implemented, is LR-VDSL likely to only be enabled for lines which receive less than 10mbps through the fibre service, or the majority of lines with less than 20-30Mbps?

It'll be likely to improve every line on the cabinet - both those using standard "short-range" profiles, and all those eligible for the "long-range" profile.

edit: To add this...

The "long-range" profile can be used for any property whose line has electrical properties equivalent to 1.25km of 0.5mm copper, or longer. That cutoff happens to be the point where BT believes lines can achieve 25Mbps.

On cabinets where "LR-VDSL" has been activated, such lines can probably squeeze a little better out, because vectoring will help minimise the effects of crosstalk.

Edited by deleted (Thu 18-Aug-16 16:26:38)

Do you know of any estimated speed versus distance graphs for LR-VDSL? I found a couple, but they're all really vague and only show really far distances, not closer ranges such as 1-2km.

There is a survey on that page about upload speeds, which I took.

The voting results given for actuals may be valid, (influenced by people reporting sync or product speed), but the "NEED" result is ludicrous. Not ISPreview's fault of course, they did their best by the emphasis repeated here, but it is not credible that 36% of users need over 20Mbps upload.

BT supplied the graph on this article:
http://www.thinkbroadband.com/news/7176-long-reach-v...

At the time, we didn't know what the technology behind options 1 and 2 were.

Now, almost a year later, we know that the technology is
- Using the VDSL2 8b profile, which allows a higher aggregate transmit power of 20.5dBm (instead of 14.5dBm), but only over 8.5MHz
- Setting the cabinet's PSD mask to allow maximum power throughout the spectrum (instead of restricting it for ADSL compatibility)
- Adding vectoring

We still don't know whether this technology is option 1, 2 or something else. My best guess would be option 1.

In reply to a post by RobertoS:

The voting results given for actuals may be valid, (influenced by people reporting sync or product speed), but the "NEED" result is ludicrous. Not ISPreview's fault of course, they did their best by the emphasis repeated here, but it is not credible that 36% of users need over 20Mbps upload.

There appears to be not a lot of critical thinking going on for some of those surveys ... some people seem to just ticked the biggest number.

In this case, I have 20Mbps, but I reckon I only actually need 5.

For my model have taken a mid point between 1 and 2 lines

We do have some speed tests from Isfield people but I'm not happy using such a small exchange sample extrapolate across the whole UK footprint.

I have 13.5 and voted 5.

I voted for 5Mb, I have about 1.1Mb upload.

If I am WebEx video conferencing or presenting slides 1Mb just about works, but makes it slow for anybody else in the house to do things as I presume any outgoing ACK's (at the DSL or HTTP level) are not sent very quickly.

If some form of QoS is enabled then VoIP or video conferencing protocols will probably have a higher priority than normal HTTP/S protocol.

I would be intrested to know what speeds these 20 houses were getting before LR-VDSL became active on their lines.

Wonder if Andrew, in his offical capacity at Thinkbroadband, could find out anything/ be nosey, from Island News & Advertiser, bound to be big news in their area, unless BT/OR has a NDA on the whole thing.

Edited by Nightglow (Fri 19-Aug-16 15:47:51)

Trial likely to be under NDA but can see speed tests

http://www.thinkbroadband.com/speedtest/results.html... from June, so believe before any trial deployment, and checker is suggesting 19 to 48 Mbps for the property at a distance of around 1.2-1.3km.

Someone closer to the cab in June got http://www.thinkbroadband.com/speedtest/results.html... which must already feel amazing after having nothing (not even ADSL)

Sorry to dig up an old thread although there also very little online on this technology for nearly a year. Somebody asked above for a graph that shows the expected uplift at the nearer distances. Couple of my clients are in the 1.5km-2km range and I've done a rough extension of the published graph that shows the 1.5km might get 35Mbps-40Mbps - which would be a welcome speed increase from the existing 20Mbps.

Does this sound feasible and two years later, are there any more firm plans for the technology?

LR VDSL has died a death, it needs ADSL/ADSL2+ removing

So for your area its nothing more than a distraction

Just to complete...

In reply to a post by MrSaffron:

LR VDSL has died a death, it needs ADSL/ADSL2+ removing

... which BT seem happy to do, but Sky and TalkTalk were threatening legal moves against. So the concept has died, alongside BT's offer to the government to meet the 10Mbps USO.

The second variant of LR-VDSL required changes to the specification in the ITU-T. This seems to be continuing, even if it has no longer has an application here.

I'm not sure if the latter is an indication that LR-VDSL may yet return.

In reply to a post by WWWombat:

Just to complete...

In reply to a post by MrSaffron:

LR VDSL has died a death, it needs ADSL/ADSL2+ removing

... which BT seem happy to do

Then why are BT (Wholesale) upgrading nearly all the remaining 20CN exchanges to 21CN (adsl2+)? Unless BT use a different flavour of adsl2+ versus the LLU operators?

20C (DSLAM) can only do ADSL, 21C (MSAN) can do ADSL2+ so as well as speed why have two platforms to maintain?

Some of that 20CN kit must be getting on now and maintenance/spares becoming an issue.
Even some ECI FTTC parts are getting difficult to replace and that's still in contract with the supplier i understand.

In reply to a post by Gadget:

20C (DSLAM) can only do ADSL, 21C (MSAN) can do ADSL2+ so as well as speed why have two platforms to maintain?

I would assume BT would retire their clapped out 20CN kit on those exchanges upgraded to 21CN/WBC/adsl2+.

Some of the exchanges being upgraded to 21CN already have kit capable of ADSL2+. The switch to 21CN is more to do with upgrading the old ATM backhaul links at these exchanges.

LLU operators sweating their copper assets will continue to block progress, preventing tech like LR-VDSL being deployed. It also prevents a full FTTP rollout and switching off the copper network entirely which could save a small fortune in any future fibre rollout.

In reply to a post by j0hn83:

Some of the exchanges being upgraded to 21CN already have kit capable of ADSL2+.

Really? I thought wrt BT kit:
20CN exchange = not capable of adsl2+, only up to 8 Mbps on adsl max (some rural ones only get 0.5 Mbps)
21CN exchange = capable of adsl2+, up to 24 Mbps
If that�s not true then I guess I�ve learnt something new!

Edited by deleted (Wed 21-Feb-18 18:14:00)

20CN exchange = not capable of adsl2+, only up to 8 Mbps on adsl max (some rural ones only get 0.5 Mbps)
21CN exchange = capable of adsl2+, up to 24 Mbps

That's very true indeed. It was more a point about upgrading equipment.
Some of the actual DSLAMs/MSANs in the 20CN exchange may already be capable of ADSL2+. They just need the backhaul links updating before ADSL2+ can be enabled.

In reply to a post by j0hn83:

LLU operators sweating their copper assets will continue to block progress, preventing tech like LR-VDSL being deployed. It also prevents a full FTTP rollout and switching off the copper network entirely which could save a small fortune in any future fibre rollout.

Then why doesn�t BT lead by example by switching off adsl1/adsl2+ at their exchanges and moving their adsl customers over to vdsl2? Maybe, just maybe, the LLU operators will then follow suit.

That would require far too many cabinets.
They could kill ADSL for FTTP, but not for VDSL2.

They would still need to maintain the copper network in the meantime for the LLU operators. There goes the savings from that, and lost income from anyone wanting cheap broadband and happy with ADSL.

Ofcom need to grow a set or we'll be using copper forever.

In reply to a post by baby_frogmella:

Then why doesn�t BT lead by example by switching off adsl1/adsl2+ at their exchanges and moving their adsl customers over to vdsl2? Maybe, just maybe, the LLU operators will then follow suit.

It isn't about switching off ADSL on a complete exchange-wide basis.

It is about switching off ADSL (and 2+) for just those customers supplied through the cabinets that require LR-VDSL activating.

My cabinet, for example, would never need LR-VDSL. The longest line is about 400m.

In reply to a post by j0hn83:

The switch to 21CN is more to do with upgrading the old ATM backhaul links at these exchanges.

This, alongside obsolete equipment, is my understanding too. The backhaul needs a serious upgrade.

Talking about obsolete equipment ... copper will have to go eventually, as even System X will get impossible to maintain.

In reply to a post by WWWombat:

Talking about obsolete equipment ... copper will have to go eventually, as even System X will get impossible to maintain.

MSANs are like DSLAMs but with integrated VOIP capability.

If you're connected to (say) Talktalk ADSL in an unbundled exchange, you're almost certainly on an MSAN, and your voice calls don't touch BT exchange equipment at all.

I don't think FTTC works this way today - I think the voice part still follows a copper path back to the exchange - but there's no reason in principle why it couldn't.

On FTTC voice still heads off to the same exchange as the ADSL based services are delivered from, i.e. your old copper pair.

The reason voice is not terminated on the VDSL2 kit, is that it would undermine a decade of investment by Sky,TalkTalk in LLU hardware to handle both voice and ADSL2+

A product called SOGEA will do away with the need for the copper between cabinet and exchange and will support a voice service using VoIP. SOGEA has been in the planning/trial phase for a couple of years.

Is SOGEA likely to become a reality for everyone any time soon, or indeed ever?

Only the retail ISP know the answer

I think it highly likely. BT consumer are doing live product trials now and the new version of their hubs are designed for it.

In reply to a post by MrSaffron:

On FTTC voice still heads off to the same exchange as the ADSL based services are delivered from, i.e. your old copper pair.

The reason voice is not terminated on the VDSL2 kit, is that it would undermine a decade of investment by Sky,TalkTalk in LLU hardware to handle both voice and ADSL2+

A product called SOGEA will do away with the need for the copper between cabinet and exchange and will support a voice service using VoIP. SOGEA has been in the planning/trial phase for a couple of years.

As a technical note, SOGEA/SoGFast does contain an E-Side cable requirement, as the line still has to connect to the EvoTAM for line testing.
It just doesn't go to the BTW Systems for WLR, or an LLU HDF.