On 09/02/2014 20:57, Andrew Gabriel wrote:
In article ,
Graham. writes:
On Sat, 8 Feb 2014 09:24:37 -0800 (PST), David Paste
wrote:

As I understand it, ADSL signals are passed along the twisted pair (is
that right?) telephone cables which are the same used for voice calls.
At a much higher frequency, of course. I am also under the impression
that the length of this cable is critical for service quality and
overall data rate (apart from junction / joint quality).

Correct.

Would using coax for the last stretch to the subscriber's premises
provide any better quality of service?

I only ask as my cable service uses coax and I wondered about the
difference.
You have sort of answered your own question.

The whole point of ADSL is that it was invented as a means to send
high speed data over twisted pairs several km long that were only
originally intended for base band voice. The system is highly
adaptive, using digital line management.

ADSL also needs a modem at each end of each subscribers line, where
co-ax distribution systems like Virgin's can be largely passive.

That's not really fair. Cable has a multi-channel VHF modem at each
end - effectively something like 8 modems running in parallel on
different RF frequencies on the same cable.

Its probably fair to say that *any* broadband technology needs a modem
at each end, almost by definition.

(whether you would argue an optical fibre is broadband or not is another
matter!)


--
Cheers,

John.

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