FTTC in this area?

Would a fibre cabinet even be able to be placed near to the current cabinet, how would the fibre travel from the exchange to the cabinet, as the current copper cables travel underground to the exchange, which is about 2km as the crow flies,without digging up the fields?
https://maps.google.co.uk/maps?q=llansadwrn&oe=utf-8...

Edited by deleted (Sat 29-Jun-13 20:48:44)

If the currect canles are ducted underground then fibre is put through a new smaller duct in the existing ducting

Expanding on MrSaffron's reply, a plastic(?) tube is passed through the existing ducting. The fibre is literally blown through that tubing.

What do you mean by blown, also how do bt choose which cabinet to upgrade, is it how many premises in the area,or?

Blown - air pressure. Like you using a pea-shooter but with a string attached to the pea. (I think pea-shooters were made illegal many years ago, so you may not know what one is).

Which cabinets - a mystery.

Yeah the pea shooters, if I get fttc, and the last leg is done by copper and is 3.5km what speed would I be looking at?

The fibres themselves have an exterior waxy coating over the bundle, this is fairly rough, which helps the compressed air get purchase on the fibre. Also, a small 'bullet' end is crimped on, again providing more resistance for the blow.

3.5k to the cab from your place ?

If so, you are looking at virtually no improvement, the faster it goes at the start, the shorter the distance it travels, VDSL gives up at around 2.5k.

In reply to a post by Loading:

Yeah the pea shooters, if I get fttc, and the last leg is done by copper and is 3.5km what speed would I be looking at?

Uh? .

as the current copper cables travel underground to the exchange, which is about 2km

Where is the cabinet?

Won't they be using vdsl2 and it is 3km.

Yes, VDSL2.

Can you explain what "3km" refers to?

In your first post you gave the line length to the exchange. What you need to know is the line length to the cabinet.

The line length to the cabinet from the house is 3km and the length to the exchange underground is 2km, resulting in a 58db line attenuation (downstream),which isn't great I know!.

At 3k, little or no joy, I'm afraid.

What no chance of fibre at all?

He means that at that distance from the cabinet you won't see much, if any, benefit.

will it be faster than the 1-2mb we recieve now?

VDSL2 performs much the same as ADSL2+ at those distances.

we only have adsl max at our exchange, it's frustrating how slow it is!
We should have better broadband than this in 2013! We only receive 1-2.5mb max
How would we be able to have better broadband without using satellites?

Pay for FTTP on demand once fully rolled out
or move
or pay someone else to roll out fixed wireless or similar in the area

Almost certainly not, no. I think service tends to run out at around 2km, possibly up to 2.5km

The VDSL2 used in the cabinets, in theory, drops to the same speed as ADSL2+ at longer distances. By that statement, most people focus on the downstream speeds.

However, the way things have been set up, it just doesn't happen in practice:

1) The very lowest frequencies, that overlap ADSL and ADSL2+ from the exchange, are deliberately crippled in the cabinet - the "PSD mask" reduces the transmit power of those frequencies (as transmitted by the cabinet) to ensure that they don't interfere with signals from the exchange.

As a consequence, you can't actually get a better speed from the cabinet than you can from the exchange, once you've gone far enough away from the cabinet to be left with those frequencies alone.

2) The limiting factor, at the longest distances, seems to be the upstream speed. You run out of connectivity here first, before you run out downstream.

I'm not sure why this is. Power shouldn't be an issue here.

Anyway, there have been a few reports of speeds in the 1.6km - 2km region where they got 18Mbps down and 1.2Mbps up - although those were probably "early adopter" speeds without much crosstalk present.

I'm not sure why this is.

Is this not because as it's the lower tones that travel furthest, on ADSL it's the upstream that uses the lowest tones. Hence even on long lines, upstream is still at full kahuna, and just the downstream dies off.

On VDSL the 'blocks' of up and downstream tones are spread through the frequency range. Hence upstream dies back in a far more pronounced fashion. Have seen a fair few 40/10 lines where the downstream is at 40 but the upstream is already off the pace, say 7 meg for instance.

This is of course all conjecture on my part, so will happily sit and wait to be shot down in technical flames.

It really depends on what happens with band US0 - the creation of which is one of the improvements made between VDSL and VDSL2 to allow for longer range upstream.

US0 is supposed to sit at the bottom of the frequency bands, just like ADSL and ADSL2+, to make sure some bandwidth is available at maximum ranges.

Unfortunately, the modem reports that DS1 spans tones 32-859, and US0 spans 0-95. Which leads to a question... just who is using tones 32-95? Up or down?

US0 is usually labelled as optional, as it isn't really needed for nearby modems. Perhaps it is really only used for distant modems.

But the overlap of bands is strange - because it shouldn't happen. DSL doesn't work if some lines in the cabinet use the US0 frequencies upstream, while other use it downstream. Too much NEXT.

The tone allocation values show that bits/tone start being allocated at tone 7 and ramp up to tone 15. Unfortunately, you don't see any gaps after that (in my stats) where you'd expect guard bands between US and DS bands. Strange... why no gaps?

The SNR values reported by the modem do fit to the DS bands precisely, with all US bands and guard bands empty. QLN and Hlog too.

Things are too inconsistent to work out what is going on.

Things are too inconsistent to work out what is going on.

There you go, my kind of answer !