[AusNOG] DSL G.Fast Details

Tue Feb 3 16:27:01 EST 2015

Hi Skeeve,

The BT article you linked in your original post was just about upgrading to vectoring (not G.fast) right now.

A couple of articles I found from a quick google about BT actually deploying G.fast are ones like this:

http://news.slashdot.org/story/15/01/31/052237/bt-unveils-1000mbps-capable-gfast-broadband-rollout-for-the-united-kingdom

http://telecoms.com/395442/bt-claims-g-fast-will-bring-uk-ultrafast-broadband/

>From the slashdot one:

"BT, has today announced that it will begin a country-wide deployment of the next generation hybrid-fibre G.fast (ITU G.9701) broadband technology from 2016/17"

The second article says (about g.fast):

"BT will begin piloting the scheme this summer in Huntingdon, Cambridgeshire, and Goshforth, New Castle"

Summer in the UK is mid year (ie. 6 months from now). I'm guessing the full scale roll out suggested for 2016/17 will probably depend on the results from the pilot.

Both fit in line with the timeframes of general hardware availability of mid-2015 from the wiki article for g.fast hardware.

regards,
Tony.
________________________________
From: Skeeve Stevens <skeeve+ausnog at theispguy.com>
To: Tony <td_miles at yahoo.com> 
Cc: AusNOG Mailing List <ausnog at ausnog.net> 
Sent: Tuesday, 3 February 2015, 14:57
Subject: Re: [AusNOG] DSL G.Fast Details

Hey Tony,

Then what is BT deploying in the UK?

...Skeeve

--
Skeeve Stevens - The ISP Guy
Email: skeeve at theispguy.com ; Twitter: @TheISPGuy
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On Tue, Feb 3, 2015 at 10:19 AM, Tony <td_miles at yahoo.com> wrote:

>
>After 250m it would probably be similar to VDSL performance (or it will drop back to VDSL).
>
>These faster technologies are just using the higher frequency spectrum, eg:
>
>ADSL - 1.1MHz
>ADSL2 - 2.2MHz
>VDSL - 12MHz
>VDSL2 - 30MHz
>G.fast - 106MHz (212MHz future)
>
>The problem being the higher frequency that you use, the shorter loop length you can support at that frequency/speed (ie. attenuation).
>
>All of the technologies have a "negotiation" (when the modem/dslam sync) where they test each frequency and decide which ones are able to be used. You would be familiar with this in the DSL world as "sycn speed". This means that on longer length cables, the higher frequencies are marked as unusable, discarded & speed drops accordingly.
>
>So if you were to look at your typical graph of speed v' distance, adding G.fast just pushes the very LHS of the graph up a bit higher at the very short distances. It doesn't reduce the speed or the distance of the 'tail' on the RHS (nor does it increase it).
>
>
>To quote from the wikipedia page you linked:
>
>"Limited demonstration hardware was demonstrated in mid-2013.[8] The first chipsets were introduced in October 2014, with commercial hardware expected in 2015, and first deployments planned for 2016."
>
>So is anyone deploying it in AU -> unlikely for at least another 2-3 years at the minimum.
>
>
>Those who are spruiking FTTN (over FTTP) show that G.fast as the logical upgrade to FTTN to increase the speeds from the currently suggested 25+Mbps with VDSL2+ FTTN rollout/trial. Of course the only way to do this is to shorten the copper loop length, by moving the 'node' closer to the end user (as you say, "shoebox on the pole" style).
>
>
>There is a lot of discussion of this on whirlpool already, have a look for some of those threads might possibly learn some more, as well as the merits of the relevant technologies (although WP discussions on the topic tend to dissolve into idealistic arguments for 5 pages at a time fairly regularly).
>
>
>
>regards,
>Tony.
>
>
>________________________________
>From: Skeeve Stevens <skeeve+ausnog at theispguy.com>
>To: AusNOG Mailing List <ausnog at ausnog.net>
>Sent: Tuesday, 3 February 2015, 8:27
>Subject: [AusNOG] DSL G.Fast Details
>
>
>
>Hi all,
>
>BT (UK) have started deploying DSL G.FAST with a stated speed of up to 500mb.
>
>They have extended their VDSL2 Vectoring trial to 100 DSLAMs (http://www.telecompaper.com/news/bt-openreach-extends-vdsl-2-vectoring-tests-to-100-dslams--1062638)
>
>I found this: http://en.wikipedia.org/wiki/G.fast and the performance of the technology is quite interesting... especially inside buildings.
>
>Is anyone deploying this in Australia... and indeed, is this what NBNCo is planning to extend FTTN with?  The Wiki refer to deployments using this as FTTdp (distribution point)
>
>Does anyone know what the average distance from a NBNCo Node to the premises will be?
>
>The Wiki doesn't give much detail what happens after 250m
>
>I like how they say that the node is the size of a large shoebox and is often mounted on a pole.  That would be less than the size of most Bigpond Cable things on poles already in place.
>
>Just interesting to know more.
>
>
>
>...Skeeve
>
>--
>Skeeve Stevens - The ISP GuyEmail: skeeve at theispguy.com ; Twitter: @TheISPGuy
>Blog: TheISPGuy.com ; Facebook: TheISPGuy
>
>Linkedin: /in/skeeve ; Expert360: Profile
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