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From: Green Xenon on 16 Nov 2009 20:38
>Not that you'd actually see 24 bits even if you increased the quality of
>the D/A converter -- 24 bits of precision is well below the threshold of

>seeing 2nd order effects, and into the really weird stuff.


But isn't it possible to build phone systems than can handle 144 dB [24
bits] of dynamic range?

Also, what are the 2nd order effects?

I ask because I like the nostalgia of dial-up access but would like for it
to be faster than what it currently is.

As I write, I'm brainstorming about dial-up internet access in which all
the devices involved have a dynamic range of 144 dB and a bandwidth of 20
kHz [the same as human audio perception] as opposed to current dial-up
internet devices which have a bandwidth of only 4 kHz.


From: glen herrmannsfeldt on 16 Nov 2009 20:41
Green Xenon <green_xenon1(a)yahoo.com> wrote:

> The following is not a homework question. It is a question of my
> curiosity.

> Currently dial up internet access has a maximum theoretical speed of 64
> kbps. This is due in part to the 48 dB dynamic range of telephone systems.

> If telephones systems are updated so that they have a dynamic range of 144
> dB instead of 48 dB, what will be the maximum theoretical speed of dial-up
> internet access?

144dB sounds like more than the electronics, and especially the
electromechanical parts can do. Do they also increase the sample rate?

The current phone system is mostly a digital 64kb/s system so obviously
the maximum rate is 64kb/s.

-- glen
From: Green Xenon on 16 Nov 2009 20:55
>Green Xenon <green_xenon1(a)yahoo.com> wrote:
>
>> The following is not a homework question. It is a question of my
>> curiosity.
>
>> Currently dial up internet access has a maximum theoretical speed of
64
>> kbps. This is due in part to the 48 dB dynamic range of telephone
systems.
>
>> If telephones systems are updated so that they have a dynamic range of
144
>> dB instead of 48 dB, what will be the maximum theoretical speed of
dial-up
>> internet access?
>
>144dB sounds like more than the electronics, and especially the
>electromechanical parts can do. Do they also increase the sample rate?
>
>The current phone system is mostly a digital 64kb/s system so obviously
>the maximum rate is 64kb/s.
>
>-- glen
>

A dynamic range of 144 dB doesn't necessarily mean the equipment produces
signals that loud.

Let's say the updated telephone systems have a dynamic range of 144 dB and
a bandwidth of 20 kHz [as opposed to 4 kHz]. What would be the maximum
speed possible of the dial-up internet access?
From: glen herrmannsfeldt on 16 Nov 2009 21:10
Green Xenon <green_xenon1(a)yahoo.com> wrote:
(snip)

> A dynamic range of 144 dB doesn't necessarily mean the
> equipment produces signals that loud.

No, the problem is how quiet they can be.

> Let's say the updated telephone systems have a dynamic range of 144 dB and
> a bandwidth of 20 kHz [as opposed to 4 kHz]. What would be the maximum
> speed possible of the dial-up internet access?

Why audio systems go to 20kHz is a good question. Only babies can
hear that high. The highest note on a piano is much lower than that.

If a new phone system came out it would surely be a digital system,
in which case there is no need to ask such questions. ISDN was
an attempt to sell digital phones to users, but not so successful.
Stories are that call-waiting killed it. (Having two phone channels
available to the home would have allowed fancier systems for accepting
two phone calls. Call-waiting was good enough, such that the need
for two wasn't there.

-- glen
From: Green Xenon on 16 Nov 2009 21:31
>>> Green Xenon <green_xenon1(a)yahoo.com> wrote:

>> Let's say the updated telephone systems have a dynamic range of 144 dB
and
>> a bandwidth of 20 kHz [as opposed to 4 kHz]. What would be the maximum
>> speed possible of the dial-up internet access?
>

>Who cares? Aint gonna happen.

I'm just curious, since I like the nostalgia of dial-up

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