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Standard User audiodud
(newbie) Mon 02-Jul-12 19:14:21
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Broadband and distance from the exchange.


[link to this post]
 
Whilst I understand, up to a point, why a broadband signal deteriorates as the line gets further away from the exchange, what is not clear though, is seeing as the broadband signal is but a digital data stream, why is it not possible to regenerate this signal at regular points along the line before noise becomes a too significant factor.

I appreciate my question is shrouded in little direct technical knowledge and thus is probably a tad naive, but I would still be interested in the answer.

Thanks in advance.

Edited by audiodud (Mon 02-Jul-12 19:15:06)

Standard User Ribble
(committed) Mon 02-Jul-12 19:25:54
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Re: Broadband and distance from the exchange.


[re: audiodud] [link to this post]
 
xDSL actually uses a number of analogue signals, and is thus prone to the effects of cross talk. As such, boosting/repeating the signal along the length of the line would casue signiificant cross talk to the variety of other data circuits in the same / adjacent cables.

Edited by Ribble (Mon 02-Jul-12 19:27:11)

Standard User audiodud
(newbie) Mon 02-Jul-12 19:35:28
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Re: Broadband and distance from the exchange.


[re: Ribble] [link to this post]
 
So presumably if you only boosted it to a maximum value that was only the equivalent to what you would find just out of the exchange, it would still cause problems?


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Standard User Ribble
(committed) Mon 02-Jul-12 19:59:00
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Re: Broadband and distance from the exchange.


[re: audiodud] [link to this post]
 
Yes, other signals would be weaker and cross talk would have a serious impact.
Standard User audiodud
(newbie) Mon 02-Jul-12 20:14:26
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Re: Broadband and distance from the exchange.


[re: Ribble] [link to this post]
 
Many thanks for the explanation. I'm sure if it had been easy, it would have been done.
Standard User XRaySpeX
(eat-sleep-adslguide) Mon 02-Jul-12 20:18:04
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Re: Broadband and distance from the exchange.


[re: audiodud] [link to this post]
 
In reply to a post by audiodud:
why is it not possible to regenerate this signal at regular points along the line
With what devices?

Can you see a load of boosting devices along your phone line to exchange? Who's gonna put them there? At what cost & who's payng?

1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 19 Meg WBC
Standard User greenglide
(committed) Mon 02-Jul-12 20:27:15
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Re: Broadband and distance from the exchange.


[re: Ribble] [link to this post]
 
Not as simple as that!

If you were simply to use a "repeater" to boost the ASDL signal (essentially an amplifier) then the noise would be amplified as well as the ADSL signal as ADSL, as has already been stated, is a collection of tones produced by the modem.

In practice what would be required is a modem to recover the digital data and a DSLAM to generate ADSL again.

This would require a power source at the repeater point (which could be supplied down the line) and somewhere to put it.

Not a particularly scalable solution and expensive for a single line.

Ex <n>ildram , been to SKY MAX - 15,225 Download
BE Unlimited - 21,000 Download 1,200 Upload ON THE LINE THAT SKY COULD ONLY PROVIDE 15,255 DOWN AND 800 UP ON!!!,
Moved house, now BE Unlimited 6,500 Down, 1Mb/s up - gutted!
FTTC Cab installation commenced 12th April - expect full 80 / 20 - bye bye BE, hello BT Infinity soon!
Standard User Al1264
(regular) Tue 03-Jul-12 00:15:08
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Re: Broadband and distance from the exchange.


[re: greenglide] [link to this post]
 
Exactly, and think what that would do to latency.
Fibre is being introduced as a much more practical soution (FTTC and FTTP) to this very problem.
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