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Guest
Thu Mar 04, 2010 4:25 pm
On Mar 4, 3:54 am, Robert Baer <robertb...@localnet.com> wrote:
Quote:
k...@att.bizzzzzzzzzzzz wrote:
On Thu, 04 Mar 2010 05:02:30 GMT, pauling...@oslotec.com (Paul Ingram) wrote:
Does anyone know what are the highest and lowest frequencies that can
be transmitted as CW over a commercial wired telephone network?
POTS is limited at the upper end by the DACs. They use 8k samples per second,
so that's ideally a 4kHz bandwidth. I'm not sure what the low end limiter is,
but it's supposed the spec is 300Hz.
Could bypassing the mic and speaker extend this range?
No.
Please comment as to WTF telcos did to throttle dial-up from 48Kbaud
to 28.8Kbaud.
Google "concentrator" a widget that pipes more lines down existing
copper pairs..
My beef is that cell uses so much compression, you cant use a modem
with cell.
And I'm stuck in a area with no wimax, so its $$$$ cable or death,
because the previous idiot renter of the apartment signed a paper
allowing removal of the copper pair...
Steve
Nico Coesel
Guest
Thu Mar 04, 2010 5:59 pm
paulingram_at_oslotec.com (Paul Ingram) wrote:
Quote:
Does anyone know what are the highest and lowest frequencies that can
be transmitted as CW over a commercial wired telephone network?
300Hz - 3600Hz
Quote:
Could bypassing the mic and speaker extend this range?
Nope.
--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico_at_nctdevpuntnl (punt=.)
--------------------------------------------------------------
John Larkin
Guest
Thu Mar 04, 2010 7:17 pm
On Thu, 04 Mar 2010 08:56:32 -0600, Vladimir Vassilevsky
<nospam_at_nowhere.com> wrote:
Quote:
John Larkin wrote:
Originally one pair of wires sent one long-distance call. Then, to
save wire, a bunch of calls were sent SSB over one pair, over
close-spaced carriers. The Western Electric "J" system used 4 KHz
channel spacings, so the baseband audio was sharply filtered between
300 and 2600 Hz to avoid channel-channel crosstalk.
2.6kHz bandlimiting significantly deteriorates the clarity of speech.
Later digital systems sampled at 8 KHz, so an antialiasing filter
preceded the digitizer, usually about 2700 Hz.
????
3.6 kHz that is.
Yup, that's better. My refs on the old FDM systems are vague, but
suggest about a 300-3500 Hz signal band, maybe 3200 Hz net bandwidth,
which fits into 4 KHz SSB spacing if you do the mod/demod well.
John
Fred Abse
Guest
Thu Mar 04, 2010 8:07 pm
On Thu, 04 Mar 2010 00:52:56 -0800, Robert Baer wrote:
Quote:
Paul Ingram wrote:
Does anyone know what are the highest and lowest frequencies that can
be transmitted as CW over a commercial wired telephone network?
Could bypassing the mic and speaker extend this range?
Paul Ingram
I think the bandwidth is supposed to be 3KHz, but do mot know if that
is the 3dB point and do not know the rolloff rate.
However, traditionally (ie up to 5 years ago and maybe later) one
could *reliably* get 48Kbaud data rate with a modem.
Not Kbaud, Kbits/sec. Baud rate is *considerably* lower (1200, or is
it 2400?). Bit rates are obtained by using fancy modulation schemes
yielding many bits per baud. IIRC, usually based on quadrature amplitude
modulation.
Shannon sets the theoretical limit.
Quote:
But (some??) telcos have deliberately, in some unknown manner,
throttled that so the best one can now do is 28.8Kbaud.
Probably down to SNR (Shannon again).
Quote:
And the response from then as well as from PUCs is "all we are
required to support is VOICE QUALITY".
All they were ever required to support.
--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
(Stephen Leacock)
Charlie E.
Guest
Thu Mar 04, 2010 8:47 pm
On Thu, 04 Mar 2010 00:54:34 -0800, Robert Baer
<robertbaer_at_localnet.com> wrote:
Quote:
krw_at_att.bizzzzzzzzzzzz wrote:
On Thu, 04 Mar 2010 05:02:30 GMT, paulingram_at_oslotec.com (Paul Ingram) wrote:
Does anyone know what are the highest and lowest frequencies that can
be transmitted as CW over a commercial wired telephone network?
POTS is limited at the upper end by the DACs. They use 8k samples per second,
so that's ideally a 4kHz bandwidth. I'm not sure what the low end limiter is,
but it's supposed the spec is 300Hz.
Could bypassing the mic and speaker extend this range?
No.
Please comment as to WTF telcos did to throttle dial-up from 48Kbaud
to 28.8Kbaud.
Probably not much...
What basically happened, was that more and more, there were 2 or more
subscribers added to a single cable pair, with carrier equipment to
share that pair between them. The carrier equipment didn't have the
bandwidth needed to support the higher modem speeds (that basically,
relied on the fact that the digital CO was digitizing right at the
cable head, so why go back to analog at the ISP...) so people got
frustrated. To the telcos, they were just selling you a voice line,
guaranteed to be usable by a telephone. If you really needed digital
transmission, then you should have to pay for a specially conditioned
line that gave you that much throughput! BTW, the data line usually
cost more than a DSL line does today...
Charlie
Adrian C
Guest
Thu Mar 04, 2010 8:55 pm
On 04/03/2010 05:02, Paul Ingram wrote:
Quote:
Does anyone know what are the highest and lowest frequencies that can
be transmitted as CW over a commercial wired telephone network?
more that 1 wpm and less than 35 wpm.
-- --- .-. ... .
--
Adrian C
Howard Eisenhauer
Guest
Thu Mar 04, 2010 11:40 pm
It's roughly between 300 to 3400 hz, thats standard for either the old
FDM or digital transport 4 khz channel systems for everything except
trans-ocianic lines which, used to be at any rate, limited to 3000 hz
to fit more calls onto the cables/satelite links. With the prevalence
of ATM these days they've probably probably gone up to 4 too.
All bets are off for IP telephony.
H.
On Thu, 04 Mar 2010 05:02:30 GMT, paulingram_at_oslotec.com (Paul Ingram)
wrote:
Quote:
Does anyone know what are the highest and lowest frequencies that can
be transmitted as CW over a commercial wired telephone network?
Could bypassing the mic and speaker extend this range?
Paul Ingram
krw@att.bizzzzzzzzzzzz
Guest
Fri Mar 05, 2010 1:05 am
On Thu, 04 Mar 2010 05:14:27 -0800, MakeNoAttemptToAdjustYourSet
<DoNotAttemptToAdjustYourSet_at_anytime.org> wrote:
Quote:
On Thu, 04 Mar 2010 06:39:17 -0600, Jim Yanik <jyanik_at_abuse.gov> wrote:
Robert Baer <robertbaer_at_localnet.com> wrote in news:-
aSdnakxDbTj6RLWnZ2dnUVZ_o-dnZ2d_at_posted.localnet:
Paul Ingram wrote:
Does anyone know what are the highest and lowest frequencies that can
be transmitted as CW over a commercial wired telephone network?
Could bypassing the mic and speaker extend this range?
Paul Ingram
I think the bandwidth is supposed to be 3KHz, but do mot know if that
is the 3dB point and do not know the rolloff rate.
However, traditionally (ie up to 5 years ago and maybe later) one
could *reliably* get 48Kbaud data rate with a modem.
I'm still on dialup,and I usually log on at 48K,according to the W98SE
taskbar indicator.Sometimes,it logs on at 49K,but it's never stable.
ISTR that the max limit was 52K,but was usually limited by coils in the
lines.
Century Link in central Florida is my telco.
NO. NONE of you get those speeds.
Wrong, AlwaysWrong. When v.90 modems first came out I was regularly doing
48-52K on one of my POTS lines (the other was stuck at 28.8 because it went
five miles, all the way back to the CO).
Quote:
Those speeds are IF the handshake
can pipe multiple streams into your NOISE FREE line.
Wrong again, Dimmie. One pipe, one stream, PCM encoded.
Quote:
The line is NEVER noise free,
Wrong, Nymbecile. Nothing is *ever* noise-free.
Quote:
and the actual hardware speed is NEVER more than 32k bits/per
second,
A lie. You're lying a lot more these days, DimBulb.
Quote:
and even that is derived from stacking several 9600 baud streams
together and that only happens on the best, most noise free connections,
which are closest to their switch.
AlwaysWrong is once again, wrong.
Quote:
It is limited by the integrity of the link between you and your first
digital switch point, which is usually not all that great.
Wrong again, AlwaysWrong. It's limited by the integrity between you and the
first DAC and the NUMBER of DACs (<28.8K if there is more than one DAC in the
link - though that is rare anymore).
krw@att.bizzzzzzzzzzzz
Guest
Fri Mar 05, 2010 1:06 am
On Thu, 04 Mar 2010 11:07:46 -0800, Fred Abse <excretatauris_at_invalid.invalid>
wrote:
Quote:
On Thu, 04 Mar 2010 00:52:56 -0800, Robert Baer wrote:
Paul Ingram wrote:
Does anyone know what are the highest and lowest frequencies that can
be transmitted as CW over a commercial wired telephone network?
Could bypassing the mic and speaker extend this range?
Paul Ingram
I think the bandwidth is supposed to be 3KHz, but do mot know if that
is the 3dB point and do not know the rolloff rate.
However, traditionally (ie up to 5 years ago and maybe later) one
could *reliably* get 48Kbaud data rate with a modem.
Not Kbaud, Kbits/sec. Baud rate is *considerably* lower (1200, or is
it 2400?). Bit rates are obtained by using fancy modulation schemes
yielding many bits per baud. IIRC, usually based on quadrature amplitude
modulation.
PCM, I think. QAM is used on the, slower, uplink.
Quote:
Shannon sets the theoretical limit.
Doesn't he always.
Quote:
But (some??) telcos have deliberately, in some unknown manner,
throttled that so the best one can now do is 28.8Kbaud.
Probably down to SNR (Shannon again).
And the response from then as well as from PUCs is "all we are
required to support is VOICE QUALITY".
All they were ever required to support.
....and that snotty attitude has lost Ma' bundles of $$.
MakeNoAttemptToAdjustYour
Guest
Fri Mar 05, 2010 5:39 am
On Thu, 04 Mar 2010 18:05:02 -0600, "krw_at_att.bizzzzzzzzzzzz"
<krw_at_att.bizzzzzzzzzzzz> wrote:
Quote:
Wrong, AlwaysWrong. When v.90 modems first came out I was regularly doing
48-52K on one of my POTS lines (the other was stuck at 28.8 because it went
five miles, all the way back to the CO).
NO, IDIOT. It was "handshaking" at that rate. You NEVER got file
transfers at that rate. Not even today. I WILL BET! FOAD!
Try it with ANY 10MB file, and the numbers and the transfer do not
match. and don't even try to hand me a load of horseshit about packet
headers, you retarded little piece of DUMB motherfucker shit. The Speeds
were NEVER attained, and I was right next door to the goddamned switch
with top gear online, fuckhead!
Not to mention that I actually researched it, and I happen to remember
what I learned. You have obviously forgotten. If you ever knew.
MakeNoAttemptToAdjustYour
Guest
Fri Mar 05, 2010 5:41 am
On Thu, 04 Mar 2010 18:05:02 -0600, "krw_at_att.bizzzzzzzzzzzz"
<krw_at_att.bizzzzzzzzzzzz> wrote:
Quote:
Wrong again, AlwaysWrong. It's limited by the integrity between you and the
first DAC and the NUMBER of DACs (<28.8K if there is more than one DAC in the
link - though that is rare anymore).
You're an idiot. It is 100% pure ISDN from the first link forward for
POTS today.
Joel Koltner
Guest
Fri Mar 05, 2010 5:42 am
"MakeNoAttemptToAdjustYourSet" <DoNotAttemptToAdjustYourSet_at_anytime.org> wrote
in message news:8h21p59cn8jfovss79anlslb0s3kei9qv5_at_4ax.com...
Quote:
NO, IDIOT. It was "handshaking" at that rate. You NEVER got file
transfers at that rate. Not even today. I WILL BET! FOAD!
I used to get ~4.5kB/s downloads with the modem reporting connecting speeds to
46-52kbps similar to what Keith reported. It wasn't twice the speed of
28.8kbps modems, but *very* noticeably faster.
krw@att.bizzzzzzzzzzzz
Guest
Fri Mar 05, 2010 5:52 am
On Thu, 04 Mar 2010 20:39:49 -0800, MakeNoAttemptToAdjustYourSet
<DoNotAttemptToAdjustYourSet_at_anytime.org> wrote:
Quote:
On Thu, 04 Mar 2010 18:05:02 -0600, "krw_at_att.bizzzzzzzzzzzz"
krw_at_att.bizzzzzzzzzzzz> wrote:
Wrong, AlwaysWrong. When v.90 modems first came out I was regularly doing
48-52K on one of my POTS lines (the other was stuck at 28.8 because it went
five miles, all the way back to the CO).
NO, IDIOT. It was "handshaking" at that rate. You NEVER got file
transfers at that rate. Not even today. I WILL BET! FOAD!
Wrong, as always.
Quote:
Try it with ANY 10MB file, and the numbers and the transfer do not
match. and don't even try to hand me a load of horseshit about packet
headers, you retarded little piece of DUMB motherfucker shit. The Speeds
were NEVER attained, and I was right next door to the goddamned switch
with top gear online, fuckhead!
Wrong, as always.
Quote:
Not to mention that I actually researched it, and I happen to remember
what I learned. You have obviously forgotten. If you ever knew.
Obviously wrong, as always.
Give it up, AlwaysWrong. You'll *always* be wrong. It's just you.
krw@att.bizzzzzzzzzzzz
Guest
Fri Mar 05, 2010 5:53 am
On Thu, 04 Mar 2010 20:41:24 -0800, MakeNoAttemptToAdjustYourSet
<DoNotAttemptToAdjustYourSet_at_anytime.org> wrote:
Quote:
On Thu, 04 Mar 2010 18:05:02 -0600, "krw_at_att.bizzzzzzzzzzzz"
krw_at_att.bizzzzzzzzzzzz> wrote:
Wrong again, AlwaysWrong. It's limited by the integrity between you and the
first DAC and the NUMBER of DACs (<28.8K if there is more than one DAC in the
link - though that is rare anymore).
You're an idiot. It is 100% pure ISDN from the first link forward for
POTS today.
AlwaysWrong does it again.
MakeNoAttemptToAdjustYour
Guest
Fri Mar 05, 2010 5:56 am
On Thu, 04 Mar 2010 22:52:44 -0600, "krw_at_att.bizzzzzzzzzzzz"
<krw_at_att.bizzzzzzzzzzzz> wrote:
Quote:
On Thu, 04 Mar 2010 20:39:49 -0800, MakeNoAttemptToAdjustYourSet
DoNotAttemptToAdjustYourSet_at_anytime.org> wrote:
On Thu, 04 Mar 2010 18:05:02 -0600, "krw_at_att.bizzzzzzzzzzzz"
krw_at_att.bizzzzzzzzzzzz> wrote:
Wrong, AlwaysWrong. When v.90 modems first came out I was regularly doing
48-52K on one of my POTS lines (the other was stuck at 28.8 because it went
five miles, all the way back to the CO).
NO, IDIOT. It was "handshaking" at that rate. You NEVER got file
transfers at that rate. Not even today. I WILL BET! FOAD!
Wrong, as always.
Try it with ANY 10MB file, and the numbers and the transfer do not
match. and don't even try to hand me a load of horseshit about packet
headers, you retarded little piece of DUMB motherfucker shit. The Speeds
were NEVER attained, and I was right next door to the goddamned switch
with top gear online, fuckhead!
Wrong, as always.
Not to mention that I actually researched it, and I happen to remember
what I learned. You have obviously forgotten. If you ever knew.
Obviously wrong, as always.
Give it up, AlwaysWrong. You'll *always* be wrong. It's just you.
Said the utter retard that actually thinks he ever got files over POTS
at 52 kbits per second.
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