Kitz Forum

Broadband Related => Broadband Technology => Topic started by: mentaltom on December 11, 2018, 11:19:59 PM

Title: Naked FTTC / VDSL Only
Post by: mentaltom on December 11, 2018, 11:19:59 PM
Hello All.

As I no longer use my landline phone, I begun searching for whether it is possible to order an FTTC connection without the need to order a voice service, or use the copper pair from the PCP to the exchange.  There are a couple of articles from 2015 mentioning Openreach are trialling it , and Sky were interested. But no further developments.

Did this development ever come to fruition? Would naked FTTC not even have the potential to decrease interference on the line and hence increase speeds?

Tom
Title: Re: Naked FTTC / VDSL Only
Post by: burakkucat on December 11, 2018, 11:53:14 PM
Did this development ever come to fruition?

I'm not aware that is has. The FTTC/VDSL2 (ITU-T G.993.2) service that A&A provide is currently the "closest" to that concept.

Quote
Would naked FTTC not even have the potential to decrease interference on the line and hence increase speeds?

Hmm . . . I'm not sure.
Title: Re: Naked FTTC / VDSL Only
Post by: gt94sss2 on December 12, 2018, 12:51:08 AM
Did this development ever come to fruition? Would naked FTTC not even have the potential to decrease interference on the line and hence increase speeds?

SOGEA is still under trial - https://www.ispreview.co.uk/index.php/2018/05/openreach-extend-sogea-standalone-fttc-broadband-product-trial.html

I cannot see it making any difference to speeds..
Title: Re: Naked FTTC / VDSL Only
Post by: licquorice on December 12, 2018, 08:50:33 AM
Was the double negative intentional there or did you intend to say that wouldn't make any difference to speed?
Title: Re: Naked FTTC / VDSL Only
Post by: mentaltom on December 12, 2018, 03:34:23 PM
I think I was about 16 hours too hasty, as this has also just been published today:

https://www.ispreview.co.uk/index.php/2018/12/openreach-start-sogea-pilot-and-reveal-standalone-broadband-prices.html

It makes sense , I am not sure why this wasn’t implemented many a year ago.
Title: Re: Naked FTTC / VDSL Only
Post by: gt94sss2 on December 12, 2018, 06:41:17 PM
Was the double negative intentional there or did you intend to say that wouldn't make any difference to speed?

Typo, fixed thanks  :-X
Title: Re: Naked FTTC / VDSL Only
Post by: dee.jay on December 13, 2018, 09:37:22 AM
I have a wires-only service from AAISP, and Sky FTTC on two lines. The speed is more or less the same.
Title: Re: Naked FTTC / VDSL Only
Post by: licquorice on December 13, 2018, 10:25:35 AM
I can't see how voice frequencies could have an impact on broadband speeds.
Title: Re: Naked FTTC / VDSL Only
Post by: jelv on December 13, 2018, 10:59:42 AM
Interference from internal extension wiring/equipment would be less likely (posting as someone who has just sorted out an internal bridge tap). So no improvement over properly set up installations but fewer issues for people who don't know what they are doing.
Title: Re: Naked FTTC / VDSL Only
Post by: Weaver on December 13, 2018, 01:50:16 PM
Contrary to what liquorice said, I seem to recall Deutsche Telekom, offering either ADSL annex I or annex J, I forget which. In E.g. G.992.3 annex I and J, the lowest tones usually used by voice are available for ADSL, so making your ADSL upstream 160k faster iirc. However, that was ADSL and no one has to my knowledge done such in the UK. I would kill for that. Really want faster upstream.

We discussed this in a thread some years back as I was longing for such a thing.

I use AA’s ADSL, and, as mentioned earlier, AA is trying to get as near as possible to a naked DSL offering, so they are following BT’s developments in this. I have no telephones.
Title: Re: Naked FTTC / VDSL Only
Post by: ejs on December 13, 2018, 06:30:41 PM
Interference from internal extension wiring/equipment would be less likely (posting as someone who has just sorted out an internal bridge tap). So no improvement over properly set up installations but fewer issues for people who don't know what they are doing.

Only due to an engineer install fitting some sort of SOGEA faceplate and disconnecting any extension wiring from the incoming line in the process. If it becomes self install SOGEA just plugging a modem into a mess of internal wiring, then the mess of internal wiring is still the problem. The bridged tap is a problem due to the DSL signal in those wires. Having no voice service makes no difference if it's the same wires and same DSL signal in them.
Title: Re: Naked FTTC / VDSL Only
Post by: meritez on December 16, 2018, 09:47:29 PM
TalkTalk Business offer something called EoFTTC, ethernet over fibre to the cabinet, it's still FTTC but higher SLA and the phone line can not be used for calls as there is no phone number attached to it, which technically makes it Naked VDSL.
Title: Re: Naked FTTC / VDSL Only
Post by: Alex Atkin UK on December 28, 2018, 12:34:54 PM
TalkTalk Business offer something called EoFTTC, ethernet over fibre to the cabinet, it's still FTTC but higher SLA and the phone line can not be used for calls as there is no phone number attached to it, which technically makes it Naked VDSL.

The key point is up until now while you CAN get VDSL without voice from a few places, it costs the same as Openreach charge for the voice anyway.

If they no longer have to maintain an E side it should cost less, thus getting a second line becomes more affordable.  Plus as said above, there is potentially the possibility of allowing data over voice tones, although its hard to say if crosstalk would become an issue there.
Title: Re: Naked FTTC / VDSL Only
Post by: j0hn on December 28, 2018, 02:40:19 PM
No idea why people keep talking about data over the voice tones in this thread.

When SOGEA roles out it will give the option to NOT use voice.
For the sake of everyone else that still uses voice they will NOT allow tones 1-5 to be used.

How much extra upstream do you expect from the U0 band using the voice tones anyway? It's a pretty insignificant amount of data to go changing the band plan in use.

I can't see it ever happening in the UK.

As has also been mentioned dozens of times, SOGEA will have a very small impact on price.
More likely pence than pounds.
Title: Re: Naked FTTC / VDSL Only
Post by: Weaver on December 30, 2018, 10:51:48 AM
J0hn is right, it’s only (iirc) 160kbps more that one gets from using the voice tones, more with a short line perhaps, I don’t know. Wikipedia says 256kbps more with 32 tones in G.992.3 Annex I I or J, and G.992.5 Annex I or J. But relative to VDSL2 speeds that doesn’t seem like much if thinking in terms of fractions. In ADSL2 it’s a big deal for the extra upstream given the pitiful amount of upstream you get.

As for crosstalk, in Germany they must have dealt with this issue somehow when they deployed Annex I/J with ADSL2+.

Question: is crosstalk frequency-dependent in general in DSL? Speculating: I think in some situations crosstalk increases with frequency. The curve I have seen is something shaped -  very very roughly - shaped like 1-e-x.

If so, then perhaps crosstalk at the low end - where the voice tones live - is not so important.
Title: Re: Naked FTTC / VDSL Only
Post by: niemand on December 30, 2018, 02:22:56 PM
In Germany they deployed Annex J where there was no POTS, ISDN was a lot more of a thing there so digital voice.

Crosstalk is as frequency dependent as everything else. The higher the frequency the higher the attenuation.

Having xDSL crosstalking with POTS is bad and crosstalk would, at a raw power level, probably be worse at the receiver at lower frequencies due to lower attenuation between transmitter, a modem, and receiver, your ears. Ever pick up a handset while a dialup call is in progress on the same line?
Title: Re: Naked FTTC / VDSL Only
Post by: Weaver on January 19, 2019, 04:28:57 AM
Sorry Carl, could you explain a little more? Why would the received crosstalk absolute power level be higher at very low frequencies than at frequencies above the audio range? And anyway, there can’t be that much crosstalk power level at the very lowest frequencies because users would be complaining about voice-voice channel crosstalk being heard.
Title: Re: Naked FTTC / VDSL Only
Post by: niemand on January 19, 2019, 04:52:56 PM
The higher the frequency of anything the higher the attenuation during transmission. Whether that's the desired signal or noise ingress.
Title: Re: Naked FTTC / VDSL Only
Post by: Weaver on January 21, 2019, 07:11:08 AM
Indeed.