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One Thing I Don't Understand About Fibre

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One Thing I Don't Understand About Fibre

There's hundreds really but the one question on my lips is:-
When a fibre cable eventually connects to your street box surely all the normal house connections running from that box must improve by leaps and bounds?
Or is the fibre connection completely separate, not replacing the original box to exchange copper wires?
If it is won't we end up with a first and second class telecoms system?
21 REPLIES
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Re: One Thing I Don't Understand About Fibre

That is a really good question
JEB
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Re: One Thing I Don't Understand About Fibre


I had this same conversation with the engineer who installed my FTTC.  Basically voice still runs on the same copper line between your house and the exchange, it is only data which runs over fibre from the green box.

James
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Re: One Thing I Don't Understand About Fibre

As I understood things the fibre connection runs from the exchange to the green box then the signal travels from the box to your home over the usual copper wires.
The point I'm trying to make, if that's the case, won't we all end up with ADSL speeds just like we were living next to the exchange?
And if that is the case, paying extra for a bit higher fibre speed won't look that attractive.
andysen
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Re: One Thing I Don't Understand About Fibre

Depends on your distance from the exchange (for ADSL) vs distance to the cabinet (for FTTC). In the case of FTTC, its highly likely that you are much closer to the cabinet, and hence can benefit from much higher connect speeds.
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Re: One Thing I Don't Understand About Fibre

Maybe I'm wide of the mark but it all comes down to the question of does the fibre completely replace the copper exchange to cabinet wires?
And will your ADSL connection improve because of that and if not why not?
andysen
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Re: One Thing I Don't Understand About Fibre

FTTC => You will use the additional fibre cables from cabinet to exchange and existing copper cabling between premises to cabinet.
FTTP => Fibre all the way to the premises.
FTTC will definitely improve your speeds, as the much shorter distance to the cabinet will enable higher sync speeds. If you are 700m from the cabinet, you will get sync speeds of up to 24Mbps.
itsme
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Re: One Thing I Don't Understand About Fibre

FTTC use VDSL and is up to 40M, there is a faster option but not widely available at the moment.
ADSL is up to 24M
The telephone, PSTN, is copper from the exchange to the house via the cabinet. When fibre is used it's teed in with the PSTN at the cabinet.
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Re: One Thing I Don't Understand About Fibre

http://www.leyingitout.co.uk/wp-content/uploads/2010/01/FTTC_Architecture.PNG shows the whole picture
The existing copper cable to the exchange remains for voice frequencies, it does not used the fibre for voice.
The new big green box terminates the fibre connection from the exchange this is then tied into the existing copper connection to your house. In the picture you can see the IDC section of the new cabinet. This is a distribution patch panel which has all the existing cabinet connections on one side and the fibre connections on the other (the electronics on the left side of the cabinet convert the fibre signal into a copper pair on the fibre side of the patch panel).
When FTTC is installed, a link is fitted in the new cabinet to link the fibre to your existing copper pair to your house. The ADSL signal is then removed from the copper connection from the exchange and your broadband connection signals then come down the fibre, then via the patch to your copper pair. The DSLAM in the new green cabinet then negotiates with your fibre VDSL router to establish the speed of connection between your house and the cabinet.
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Re: One Thing I Don't Understand About Fibre

So it is separate.
I expect eventually it won't be. Sometime after everyone has bought into the fibre "dream".
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Re: One Thing I Don't Understand About Fibre

Quote from: billnotben
So it is separate.
I expect eventually it won't be.

It would seem quite logical that if new infrastructiure is provided to, say, a new housing development in an area served by a fibre enabled exchabge then it might save BT money if they don't have to lay copper as well as fibre to the cabinet (same way that Virgin media currently works in cablle areas telephone calls as well as broadband [+TV] all down the same fibres), they can still give a speed limited service on a line that's 'up to 40meg'  and charge a premium for those that take advantage of BT's cost saving on copper wire  Tongue
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Superuser
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Re: One Thing I Don't Understand About Fibre

Wouldn't that mean they'd have to put MSANs in the cabinets instead if DSLAMs? Don't suppose there's any reason why they couldn't.
David
itsme
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Re: One Thing I Don't Understand About Fibre

MANS are used in FTTC
The problems that BT has unlike Virginmedia are
1. They have to supply a telephone service to every household. Unlike VM which only urban areas. Not cost effective to use fibre and place equipment into street cabinets for small population areas. Cheaper to run to an exchange using copper.
2. BT are under an obligation for the telephone service to work when there is a power cut believe VM are not and their system will not. BT can't fit a backup generator to each cabinet.
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Re: One Thing I Don't Understand About Fibre

Quote from: itsme
BT are under an obligation for the telephone service to work when there is a power cut believe VM are not

I can believe that but it doesn't really make sense: If a house only has a VM telephone line then that suggests they don't have the right to emergency calls during a power cut, for the same service type the same rules ought to apply.
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Re: One Thing I Don't Understand About Fibre

[quote=itsme]BT are under an obligation for the telephone service to work when there is a power cut believe VM are not and their system will not. BT can't fit a backup generator to each cabinet.
I live out in the countryside, where currently I get the full 8Mbps of ADSL_Max, but we have mains power interruptions several times a week.
I have overcome the local mains power problems by running separate UPS for each of my PCs, router, phones, PVR, TV, and heating boiler !
This setup gives me uninterrupted internet and phone access for about three hours, which is usually enough for most outages.
In this hypothetical case, if in the distant future BT put FTTC into the cabinet (outside my front door), do you think that I will lose my internet connection during a power cut - if I switch to fibre ?