Vectoring

Spotted the following in a news article ontelecompaper

Shows that vectoring is giving 100Mb over 300m and is being rolled out in the EU. It will be interesting to see when this is rolled out in the UK.

Huawei Poland announced completion of the final phase of work on its vectoring system, thereby enabling mass deployment. The system developed by Huawei can reach speeds of over 100 Mbps over a distance of up to 300 meters over a single copper pair. Copper cables in Poland are available in almost 100 percent of premises, office and residential. In 2009, Huawei presented a prototype of vectoring and carried out the first tests in collaboration with BT and Swisscom. However, the development of vectoring faced problems of compatibility with the older generation of subscriber devices operating in existing networks. To overcome this, Huawei has developed the Auto Sense Function that automatically identifies the user terminal equipment and thereby applies appropriate operation on the DSLAM. As of April, Huawei provided globally more than 1.2 million VDSL2 vectoring lines.

http://community.plus.net/forum/index.php/topic,1142...

http://www.ispreview.co.uk/index.php/2013/04/bt-conf...

Watching & Waiting!

In reply to a post by shalom2005:

http://community.plus.net/forum/index.php/topic,1142...

http://www.ispreview.co.uk/index.php/2013/04/bt-conf...

Watching & Waiting!

Me too. I reckon my line will be a good test. It started off syncing at 79999 with (I think) 91 attainable. 12 months later and it just had DLM remove interleaving and it's connected at a tad under 72.

this line is telling

As of April, Huawei provided globally more than 1.2 million VDSL2 vectoring lines.

someone on here said to me there is no live use yet its barely out the labs :

In reply to a post by Chrysalis:

this line is telling

As of April, Huawei provided globally more than 1.2 million VDSL2 vectoring lines.

someone on here said to me there is no live use yet its barely out the labs :

Just goes to show, no one knows everything!

In reply to a post by Andrue:

In reply to a post by shalom2005:

http://community.plus.net/forum/index.php/topic,1142...

http://www.ispreview.co.uk/index.php/2013/04/bt-conf...

Watching & Waiting!

Me too. I reckon my line will be a good test. It started off syncing at 79999 with (I think) 91 attainable. 12 months later and it just had DLM remove interleaving and it's connected at a tad under 72.

Likewise at 450m with 46meg sync I'm well under the "typical" curve. At least mine is stable, but its always been interleaved.

If you go to the Main Site and search the News Articles for Vectorin there are eleven hits. This one is probably the best for now.

In reply to a post by jchamier:

Likewise at 450m with 46meg sync I'm well under the "typical" curve. At least mine is stable, but its always been interleaved.

This document, from the Broadband Forum, has an interesting graph - Figure 6.

It shows both vectoring behaviour, existing behaviour with crosstalk, and the worst-case behaviour, for the 17a profile on 0.4mm wire. That suggests 100Mbps over 500 metres, showing the Polish results aren't so outstanding.

That graph shows your speed is very much at the worst-case speed for your distance.

ADTran have a "what's next" presentation that shows a distance of 400 metres for 100Mbps, on 0.4mm wire, but also state that vectored reach should be multiplied by 1.3 for 0.5mm wire.

Finally, Alcatel-Lucent have a paper on their trial results, showing that recent results are an improvement over early results from 2010-2011. Those trials show 100Mbps at 500 metres, with a statement "Wire diameter and cable type do have an impact on the results and account for most of the variation [...] with commercial equipment".

what about 0.2 wire and ali ?

You have 0.2mm wire? That's incredibly thin - and is more usually seen when combined in multi-stranded cable, which we don't tend to see as telephone cable. I wouldn't expect VDSL2 to go very far at all on that.

I thought we tended to get, in the D-side, more 0.5mm stuff, some 0.4mm stuff and some 0.9mm stuff.

(In my old neighbourhood, some blocks of flats got markedly higher speed predictions compared to the nearby houses. The best explanation would be that they were fed by a batch of 0.9mm cable)

Aluminium - well, we all know it attenuates the VDSL2 signal more, so has a reduced range. However, I don't think anyone has quantified it well enough - partly because you can't tell how much aluminium is in the line.

Is aluminium cable worse than copper on VDSL due to the corrosion problem at the joins. Or is the poor performance due to its attenuation properties being worse than copper at high frequencies?

both.

And that thread mentions 0.32mm Aluminium. Ugh

yeah is some 0.2 in use.

0.32 ali top quality stuff

I'm pretty sure mine is 0.5mm, the estate is only 5 years old, but I'm so close to the cab it don't makes much difference.

My parents have 170 meters Alu D-side and they have over 100mbit attainable rate (was as high as 140) they have had 0 crc errors in about a months uptime.

Edited by lockyatlrg (Tue 18-Jun-13 11:46:44)

Interesting article

http://www.ispreview.co.uk/index.php/2013/06/bt-prep...

I am connected to LNBAR and can only hope that I am included in the trial. Apparently the way it works is that all people are or BTO gives the ISP a list.

I know to which cab I am connected, but not by uts number. Any way for me to find out?

Thanks

DrT

In reply to a post by DrTeeth:

I know to which cab I am connected, but not by uts number. Any way for me to find out?

a) The number is painted on the PCP cabinet, so if you know where it physically is located, that'll tell you.

b) Use this checker with your phone number. The first line of the result should tell you the cabinet number.

Thanks for the link - worked a treat.

Cheers

DrT

the barnet cabinets in the trial appear to be one near 'Hadley Wood' station (26), and 2 in Arkley, (41,42) (one opposite the Arkley pub, and the other at the top of Quinta drive)
I did see something suggesting they were also testing about interference from radio stations, and the arkley ones are very close to the 'Saffron Green' transmitter.

Edited by ggremlin (Fri 28-Jun-13 20:41:58)

Mine's 50, nowhere near those.

DrT

In reply to a post by ggremlin:

I did see something suggesting they were also testing about interference from radio stations, and the arkley ones are very close to the 'Saffron Green' transmitter.

Right.

I think the perceived solution is to set the vectoring process to ignore the affected frequencies. But it should be a good test to see if that happens automatically, or needs to be done manually.

I also wonder if we have any subscribers in the area, so we can get some graphs from unlocked modems during the trial

I suspect the Hadley Wood cabinet was selected because it is beside the East Coast Main Line.

In reply to a post by ggremlin:

I suspect the Hadley Wood cabinet was selected because it is beside the East Coast Main Line.

are BT hoping for miracles?

vectoring is for crosstalk noise not external

I would guess that they believe Vectoring works OK when the only noise around is crosstalk. What they probably want to see is how it performs when significant external noise is present too.

RF and electrical noise from electrified rail lines, radio transmitters and aircraft beacons/radar all sound like good test locations to me.

yeah that would be a valid reason.

External noise *IS* crosstalk noise. If it's affecting a line from a known stable baseline, vectoring will try to filter it out just like noisecancelling does on some mobile phones to block out road traffic noise etc.

Edited by LeJimster (Thu 04-Jul-13 23:23:17)

By "external", I'd normally expect it to mean from a source outside the cable.

Crosstalk is very firmly just from within the cable - other subscribers to DSL. FTTC subscribers mainly, as the ADSL crosstalk (from the exchange) is considered "alien" and cannot be removed by vectoring. Luckily it is a small-ish portion of the spectrum (and smaller, the further the cabinet is from the exchange).