Kitz Forum
Broadband Related => Broadband Technology => Topic started by: mentaltom on December 11, 2018, 11:19:59 PM
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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
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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.
Would naked FTTC not even have the potential to decrease interference on the line and hence increase speeds?
Hmm . . . I'm not sure.
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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..
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Was the double negative intentional there or did you intend to say that wouldn't make any difference to speed?
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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.
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Was the double negative intentional there or did you intend to say that wouldn't make any difference to speed?
Typo, fixed thanks :-X
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I have a wires-only service from AAISP, and Sky FTTC on two lines. The speed is more or less the same.
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I can't see how voice frequencies could have an impact on broadband speeds.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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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?
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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.
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The higher the frequency of anything the higher the attenuation during transmission. Whether that's the desired signal or noise ingress.
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Indeed.