BT considering trial of G.fast

Can't see it helping me too much at almost 600m to the cab but good if you are close! Nice to see BT looking forward and could be a cheaper alternative to FoD

http://recombu.com/digital/news/bt-trial-gigabit-spe...

Edited by deleted (Mon 20-May-13 14:44:27)

Cheaper than FoD, but more than FTTC.

Hard to see this being a major product in the next 2 to 3 years, but maybe in the 5 to 10 year range perhaps. Too much spent on FTTC to abandon so early

Pretty lame story. It misses the whole shift in network architecture that V.fast needs to underpin it.

V.Fast does work from "a" cabinet, but isn't very likely to be the cabinets as we know them.

V.Fast will give high speeds in the 100-200 metre region, and is meant to tie in with a concept known as FTTdp, where the "cabinet" is located at the distribution point, is much smaller, and perhaps serves a few dozen properties.

In the current network architecture, perhaps only 20% of premises can be found within 200 metres of existing cabinets. Is there likely to be enough take-up within that portion to make it worth upgrading the whole cabinet? Especially as all those customers will be able to get 100Mbps vectored VDSL2 by then?

So V.fast is unlikely to happen with existing cabinets. It needs new cabinets, adding them at distribution points (either up telegraph poles, or placed underground), and being deeper into the network.

There's a UK-centric summary here:
http://www.uknof.org.uk/uknof21/Maes-Gfast.pdf

There's another US-centric version of the same slides here, with more technical information:
http://www.belllabs.be/opendays/archive/2012/jochen_...

It is still cheaper than full FTTH - probably - but the control of costs will need to be even tighter, or you might as well go for FTTP instead.

I suspect, though, that the decision about whether or not to ever deploy FTTdp and V.fast will depend on the take-up of FTTPoD.

I'm one of those 20%

DP is underground next to the pole less than 20 metres away

you seem to have very good luck with xDSL.

never affected by BE outges/faults.
FTTP trial.
rIght next to DP.

Are you also right next to a cabinet?

You seem the luckiest person on here.

The 20% figure was referring to those close to the cabinet, not the DP. Are you also close to the cabinet?

I saw something recently that suggested almost everyone was close to their DP. But I can't recall where.

DP is underground next to the pole less than 20 metres away

You sure ?
Normally, if pole fed, the DP will be the block at the top of the pole ?

Whats V.fast? =)

I'm not sure of the extact setup of Vectoring aka G.fast. But it is certainly not just for those within 100-200m. Their are benefits for those upto 1.2km from the cabinet from the independent testing, showing 40Mbs is possible at that range and there is a white paper out there that describes the benefits of vectoring on adjacent non-vectored lines as there can be a reduction in gain on vectored lines which helps reduce crosstalk interference for everyone.

In reply to a post by LeJimster:

Whats V.fast? =)

I can't even claim finger trouble for that, can I? It must have been temporary insanity.

I'm not sure of the extact setup of Vectoring aka G.fast.

G.fast is a DSL standard, the next one due after VDSL2 (G.993.2), aimed at using frequencies of over 100MHz, and is definitely aimed at shorter copper loops than VDSL2 - 200 metres instead of 2km.

Right now, vectoring is a different standard (G.993.5, used to be called G.Vector), and is designed to be built on top of VDSL2. However, the technique of vectoring seems to be an integral component in the G.fast spec.

G.fast, at such high frequencies, then really only works when it starts from a node closer to the customers than today's PCP. In BT's network, that node would likely be the DP - usually within 100 metres of the end-user. That is why you tend to see the G.fast specification go hand-in-hand with the other technology needed for nodes at the DP (aka FTTdp).

Plain vectoring, applied to VDSL2 at the PCP, gives the other benefits you described.