Hi all:

I have been around since the 300 baud days. Slowly, modems went
up in speed. Eventually, to 9600, 14.4 . Then the speed seemed to go
up very fast. It seemed promising when it hit 28.8 quickly followed
by 56k. I was very hopeful that it would continue to go up. However,
it has been many years and that has not happened.

Why is the FCC in collision with the big communications companies
in trying to limit the poor man's high speed? Why would fcc make such
an unjust agency law?

Someone who knows about this, please enlighten me. Am I missing
something? Why isn't the American poor outraged? Are you as outraged
as I am?

sincerley, Moser.

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At 2004-02-02T18:34:51Z, saylo1234@aol.com (LovingPerson) writes:

Telephone equipment is designed to accept certain power levels. If someone
exceeds those power levels, it could disrupt the phone equipment. If the
phone equipment were disrupted, it could cause service outages. Part of the
FCC's regulatory mission is to keep people from doing things that will knock
out public services, and they do this by passing laws making those acts
illegal.

OK, then. That means that a modem can only transmit at a certain power
level, and no more. The speed limit you're referring to reflects the
maximum amount of data that can be transmitted over telephone lines via an
analog modem at the legal power levels so as to avoid disrupting telephone
service for everyone else.

Does that clarify things, or were you hoping for a more paranoia-fueled
answer?
- --
Kirk Strauser
The Strauser Group
Open. Solutions. Simple.
http://www.strausergroup.com/
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In comp.dcom.xdsl LovingPerson <saylo1234@aol.com> wrote:
Ditto here, and I've used some 110 too.

Because the phone lines were designed for voice (remember
acoustic couplers?) which requires fairly limited bandwidth,
64 kbit/s max. The Signal-to-Noise ratio combined with a
3750 baud (max) rate doesn't allow more info to pass.

The chief bottleneck is using audible frequencies and
multiplexing for voice transmission trunking. xDSL gets
around this by using higher frequencies on the short local
loops and separate data transmission trunking.

They didn't. It's simply physics. Do you believe that the
FCC or even big comms are competent enough to surpress a market?
You give them _far_ more credit than they deserve and have shown.

-- Robert

On Mon, 02 Feb 2004 19:15:06 GMT,
Kirk Strauser (kirk@strauser.com) wrote:
And even 56k works because one end of the connection (telco to service
provider) is all digital, meaning that a single analog to digital signal
conversion is done.

However, if you cannot get a digital line, you can consider using inverse
multiplexing modems (or bonding modems) to achieve 112k or beyond using
analog lines.

--
Bev A. Kupf
"The lyfe so short, the craft so long to lerne" -- Chaucer
Tintin turns 75 <http://www.tintin.com>

In article <fed77941.0402021034.6ffbbb8b@posting.google.com>, LovingPerson wrote:
56K. Yes a law is a dumb idea but.. its done. Even if you had a modem
that COULD go faster than 56K do you realize that most American
Telephone systems Can't even handle 33600bps well. Thats due to the
wiring of the telephone system itself.
As for Poor mans High speed access. Have you checked out
Planet Maca's Shell acounts yet? you get 33600bps but a real Unix
shell where you can download to/from. Plus Email, Free Usenet
Newsgroups and the account does not allow easy spread of trojans and
Virii? No Popups or time limits, you get a 20MB of disk space on the
free access level. Planet Maca's Opus is listed as a Freenet (Free Shell
account ISP) not Peer to Peer. and is dialup accessable with any standard
terminal program? See my signature for access info.

--
From the Desk of the Sysop of:
Planet Maca's Opus, a Free open BBS system.
Telephone 860-738-7176 300-33.6kbps Telnet://pinkrose.net.dhis.org
The New Cnews maintainer
B'ichela

On Mon, 02 Feb 2004 19:15:06 GMT, Kirk Strauser <kirk@strauser.com> wrote:

He may be complaining about being mislead by having the product
labelled as 56k capable without any warning that the customer will not
be able to use the "capability".

As an example, most modern automobiles are capable of driving over
100 mph but you see very little advertising that says "buy our 100 mph
automobile!".

He may agree with me that the manufacturers should be required to
mark the product with the useable speed.

Jack

B'ichela <mdalene@pinkrose.net.dhis.org> wrote:
The rule is neither unjust, nor is it "in collision with the" whatever.

No it is neither a dumb idea, nor does have anything directly to do
with bandwidth.

Again, that just isn't true. Consider that the standard T1 lines,
running 1.544 Mbps (with a bandwidth of 772 KHz) uses standard
telephone lines.

The limitation that prevents 56K modems from using the same
technology to go faster is a result of /two/ things. One is
power, the other is bandwidth.

As Bev A. Kupf mentioned in her excellent article, the high
speed down link side of a 56 K modem is digital all the way, and
involves exactly one CODEC in the telephone company equipment
(and another one in your modem, for a single pair). Normally
that telco CODEC is used to convert PCM (digitally encoded
voice) back to (quasi-) analog, but with a v.90 modem it is fed
digital data and the Pulse Amplitude Modulated output is used as
a digitial signal rather than as an analog signal. The
/bandwidth/ limitation is that the sampling rate for the CODEC
is 8000 Hz, meaning it cannot use more than 4Khz of bandwidth
for its output.

Hence, the only way to go faster, using that equipment, is to
increase the /power/ level. What the FCC has done (70 some
years ago) is determine what the *maximum power* that any one
telephone line can used without interfering with other telephone
lines using the same cable facility.

Hence it is a very smart specification, and quite just. It
prevents your neighbors' modems from interfering with *your*
voice calls (not to mention your modem connection too)!

It is definitely *not* something you want changed! The
appropriate way to get higher speeds over telephone cables is to
use different equipment at the telco. That is what DSL, ISDN,
and T1's (as well as cable modems, which use different kinds of
cable) do, and that equipment allows higher *bandwidth* (not
more power) to be used over a given cable.

--
Floyd L. Davidson <http://web.newsguy.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@barrow.com

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At 2004-02-02T21:25:12Z, J. Yazel <jyazel@ai5.net> writes:

I'm pretty sure he was grousing that we don't have 122Kbps modems, not that
he can't fully use his 56K modem.

I don't think that's a good analogy. Modems are limited to 56K by the
design of the telephone system, not by some arbitrary legal restriction.
You're perfectly free to run your modem as fast as the "road" between your
computer and your ISP will allow.

Define "usable speed". When I was a sysadmin at an ISP, some of our
customers routinely connected at 51K+, while others were limited to 26400
(oh, how we hated pair gain). How would you require the manufacturer to
label that?
- --
Kirk Strauser
The Strauser Group
Open. Solutions. Simple.
http://www.strausergroup.com/
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The problem is, we are asking the wrong question. The real question is
not 'What it the most data we can transmit over a wire between two
points?' It is 'What is the most data we can transmit over the dial up
telephone network?'

We can transmit a lot of data between two points. Certainly a few Mbs
over a high speed line. Much more if we are prepared to pay for a
dedicated line. But the ability to dial up anyone in the world, or even
anyone in North America is something else.

The real reason is very simple: the dial up system ( Called the Public
Switched Telephone System or PSTS) is designed to make voice
connections, person to person, on demand. Voice is analog and
historically about 4 kHz bandwidth was enough. As the world went
digital, only the connection from your house to the nearest telephone
office remained analog, all the conneections between offices, and all
the switching which routed your connection to the right destination
became digital, was almost univerally standardized on 8000 samples per
second (to allow nearly 4 kHz analog signals to be represented) and 8
bit samples to provide sufficient signal to noise. So the connection
between telephone offices is basically 64 kbs. In fact some of the
transmission equipment uses one bit per sample for other purposes, so
the most you can rely on is 56 kbs of clear channel. Thats all the bits
there are, you can't do better unless you redesign the whole PSTS.

Technically, your ISP can send a 56 kb signal to you. He sends it as a
digital stream to the telephone company, they forward it to an exchange
near you, they convert it to analog there and send the result to you
just as if it were voice, and your 56 kbs modem can turn it back into
data stream for you. Turns out it doesnt quite work, because the analog
signal created at the last leg is powerful enough at certain frequencies
to create interference with neighboring phones, so it had to be reduced
from 56kbs to 53kbs to eliminate this interference.

Even that you can only do if the sending end (your ISP) has a digital
link to the phone company. For ordinary consumer connections, there is
an analog link at each end, which introduces enough extra distortion
that you can't reliably transmit better than 33 kbs. Its actually
amazing you can do that well.

But, bottom line, there is a hard limit of 56 kbs over the public
switched telephone network, and practical limits rather lower. Its not a
regulatory decision, and its not basically about signal to noise ratios
over the line to your house, its fixed because that is how the PSTS
works.

quoting:

Ah yes, ISDN. ISDN is a digital phone line. With an ISDN line, you get a
direct digital connection all the way. You get the full 64kbps, as long as
you're dialing into the ISP's ISDN lines. Duel channel ISDN is 128kbps
becuase you're getting two phone lines, and using the bandwidth of those two
phone lines.

The analogy still fits. Automobile speeds are limited by the design of
the highway system (and of the automobiles), also not by some arbitrary
legal restriction.
I was referring to the government established maximum speed. Just as
in road speeds, that it the fastest that you are allowed to go.

Jack

On Mon, 02 Feb 2004 22:33:41 -0500,
J Yazel (jyazel@ai5.net) wrote:
This discussion is like a broken pencil - pointless. Nevertheless - your
analogy is incorrect. As Kirk and Floyd Davidson have pointed out in their
excellent posts, 56 kbps is _not_ a legislated limit. It is a limit
dictated by telco hardware.

On the other hand, 65 mph (on US highways) is a legislated limit. Existing
highways can tolerate higher speeds, and existing cars can operate at
higher speeds, and I'll wager that several of us here have proven that.

That then is the difference. 56 kbps is the fastest you _can_ go. You
cannot break that barrier with an existing analog telephone line. 65 mph
is the fastest you are _allowed_ to go on an existing highway. You can
break that barrier with existing conditions.

Beverly
--
Bev A. Kupf
"The lyfe so short, the craft so long to lerne" -- Chaucer
Tintin turns 75 <http://www.tintin.com>

On Tue, 03 Feb 2004 03:45:32 GMT, "Bev A. Kupf" <bevakupf@myhome.net> wrote:

I don't think you understand the subject here. 56k is not a legislated
limit and it is also NOT dictated by telco hardware. I have seen hundreds
of messages stating that the legislated limit on telco lines is less than 56k
because of hardware power limitations.

As far as I know, there is no 56kbps tel. line barrier. The only barrier is
a lower legislated one. Just as on a highway you can drive faster than the
safe legislated speed, you can also send 56k illegally on a tel. line.

Jack

On Tue, 03 Feb 2004 14:49:10 -0500,
J Yazel (jyazel@ai5.net) wrote:
Replace 56 kbps with 53 kbps - mandated limit. The original poster
wondered why analog modems supporting bps rates faster than 56 kbps
didn't exist. That _is_ a limit of existing telco hardware. Ergo
the following still holds true.

But no rate higher than that; that which the original poster desired.
Nolens volens, you cannot exceed 56 kbps on existing telco lines with an
analog modem. But you can drive faster than 65 mph (or 75 mph) on a
highway.


--
Bev A. Kupf
"The lyfe so short, the craft so long to lerne" -- Chaucer
Tintin turns 75 <http://www.tintin.com>

The really interesting part is that many. many 56K modems can't even
break the 30 K barrier and that ties in with the 53 K limit.

"Bev A. Kupf" <bevakupf@myhome.net> wrote in message
news:slrnc1vvlo.ieh.bevakupf@myhome.net...

J. Yazel <jyazel@ai5.net> wrote:
....

If you will go back and carefully read the entire thread, there
are at least two or three different articles which explain that
in detail.

The absolute limit per line due to the theoretical design of the
Public Switched Telephone Network (PSTN) as it exists today, is
64Kbps. The practical limit, due to hardware installed, is 56
Kbps. The actual limit, due to typical characteristics of
circuits and attempts at designing a modem to work the best it
can on the average line, is 53 Kbps.

The basic increment of bandwidth used for the PSTN is a DS0,
which is 64Kbps. Until that changes (when the PSTN moves from a
"circuit switched" network to a "packet switched" network), the
64 Kbps upper limit is solid. That is simply because telephone
switches switch DS0's, not DS1's or whatever.

As has previously been noted, there are _several_ reason that
equipment currently installed will not actually provide a clear
channel 64Kbps data rate to a customer. That is because there
are several equipment implementations that use up to 8Kbps for
various other purposes, such as testing, signaling, or
reliability. (Worse yet, there are *many* places where
equipment is in use that actually only provisions 32Kbps per
line, not 64!)

The 53 Kbps is actually a modem manufacturing compromise between
what could be done, and what will work best for most users. It
would be quite possible to assume 1) less cable noise and 2)
more precision from the telco CODEC, and on the one-half of one
percent of all telephone lines where those conditions exist, 64
Kbps would be possible! That is to say, that if a precision
CODEC (spelled "expensive") were used in a line card that is
connected to a short (say 1/2 mile or less) high quality cable
in an area with very little external noise and with no other
users on the cable, it is relatively easy to redesign almost
any v.90 modem to achieve 64 Kbps. (Or, forget the telco codec
and the cable, just use two modems back to back with a 6 foot
patch cord between them!)

That modem would not perform well for users with a typical line
though... So, instead of proving it can be done and going
broke, modem designers have provided modems which do as best
they can on the majority of lines, and in the process they've
simply tossed that miniscule number of users that could get
another few Kbps.

Now, where does anything you could call "legislated" fit into
the picture?

--
Floyd L. Davidson <http://web.newsguy.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@barrow.com

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At 2004-02-03T21:49:27Z, "Steve Baron - KB3MM" <SteveBaron@StarLinX.com> writes:

Example?

I've never seen a modem that couldn't break 33600 *given decent phone lines*.
- --
Kirk Strauser
The Strauser Group
Open. Solutions. Simple.
http://www.strausergroup.com/
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In article <87r7xbg5o4.fsf@strauser.com>,
Kirk Strauser <kirk@strauser.com> wrote:

You've never seen mine.

Oh, wait... you said "given decent phone lines"... Never mind.

(Sitting at the end of nearly 20 miles of mixed copper and glass, and
considering myself lucky when I get a connection above 26400 that holds
for more than 5 minutes at a stretch. People just a mile further up the
road - which translates to about 7 miles up the wire due to the
geography around here - consider it near-miraculous when they get a
connection faster than 9600. They call it a full-blown miracle when a
connection *AT ANY SPEED* holds for longer than about 8 minutes without
getting dropped.)

--
Don Bruder - dakidd@sonic.net <--- Preferred Email - SpamAssassinated.
Hate SPAM? See <http://www.spamassassin.org> for some seriously great info.
I will choose a path that's clear: I will choose Free Will! - N. Peart
Fly trap info pages: <http://www.sonic.net/~dakidd/Horses/FlyTrap/index.html>

J. A. Mc. <jaSPAMc@gbr.online.com> wrote:
How does that relate a v.90 modem though? In fact, there is no
posted limit for the modem. Instead, the same thing happens
with the modem that happens on the road: if you go too fast for
the conditions you will seriously corrupt whatever you are
transporting that fast. On the road, your life and your body
are distorted, sometimes beyond recognition or recovery. Same
with data over a telephone line.

The power limits on telephone lines are not some arbitrary
limit. Originally the specifications were designed around the
effects of crosstalk between cable pairs and the intermod
distortion caused when high levels are introduced into Frequency
Domain Modulation (FDM) telephone carrier systems. Later on,
microwave radio systems were designed to match the exact same
limits that cables had, thus if a signal was too high for a
cable, it would also be too high for the carrier and for the
radio.

That design target was also used in the theoretical design of
the digital hierarchy, and implemented in the physical design
of Time Domain Modulation (TDM) digital carrier systems. The
dynamic range of a PCM encoded quasi-analog channel carried by
digital facilities is matched very closely to the dynamic range
1) required for human speech recognition, 2) available from
typical telephone cable designs, 3) available from typical
telephone carrier designs, and 4) available from typical
telephone microwave designs. The *same* upper power level per
channel applies to *all* of them! (Actually TDM has a slightly
lower limit, which is explained below.)

This power limit is simply a matter of if you put two signals
onto different pairs in a cable, they *will* show up on all pairs
in the cable. If the level is high enough, they *will*
interfere with each other. Likewise channels in a FDM carrier
system suffer from inter-modulation if the levels are too high.
Likewise with microwave radios, where FM modulation has what is
called a "knee", which is a point at which loading the system
more no longer results in a linear increase in distortion, but
instead there is an exponential increase in distortion.

The TDM digital carrier systems that are almost universal today
are slightly more sensitive to levels. There are only 255 codes
available with PCM to indicated a voltage level. The lower
levels are right down there with the typical noise on a cable.
The upper level is only 3.7 dB above testtone level! (The upper
level for cable is +5 dB.) If you crank your modem output level
up 10 dB, you *don't* get a 10 dB higher signal at the distant
modem... you only get 3.7 dB louder, and every voltage that
originally went over the limit is grossly distorted. (Your data
will not be recoverable!)

There is no posted, legislated, mandated or whatever speed
limit. It's just a simply a fact of the physical design of the
roadway that you can drive the car around that bend at 35 mph,
but if you try to do it a 75 mph, you'll be rolled up in a ball
somewhere off the road and in one big hurt.

--
Floyd L. Davidson <http://web.newsguy.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@barrow.com

"Steve Baron - KB3MM" <SteveBaron@StarLinX.com> wrote:
How?


--
Floyd L. Davidson <http://web.newsguy.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@barrow.com