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Just
how fast is dial up internet? Thats easy, 56k. In fact the term
" 56k "
is
synonymous with " dial up ". Lets look at what 56k means numerically,
then what it means relative to download speed. To fully
understand what 56k means you have to look at it long form. 56k is
short for 56kbit/s. Lets lengthen 56kbit/s
further.
K is short for the prefix Kilo. Kilo means 1000.
A " bit " is the computer data. A bit is either a 0 or a 1.
The / means per.
S is for seconds of time.
Per second makes 56k a rate of speed like miles per
hour.
And so, if I asked the question how fast is dial up internet, the long
and more descriptive answer would be: The rate of speed one
computer can download data from another computer over standard
telephone lines is 56,000 bits every second.
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zeros and ones per second doesn't tell me how fast I can download a
song or a book. We can use 56,000 bit speed to determine how long
it will take a 1 page document.
The length of a txt file, or any file, is defined
in units of bytes. For this example I will say the txt file
we are downloading is a 1 page document containing 3000
letters. Each individual letter or character on the document
is 1 byte. It doesn't matter what the character is. " a " "
& " " 9 " are all valid characters and
individually they are 1 byte long. That means our txt file is 3KB in
size. |
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A byte or letter is 8 bits. (3000 x 8 = 24,000). Our document
contains 24,000 bits. Since dial up is 56k, it would
take approximately a little less than half a second to download this 1
page document.
Compare this to an mp3 file that is 5MB (megabytes) long.
There are 1024 bytes in a kilobyte. There are 1024 kilobytes
in a megabyte. That means there are 41,943,040 bits in a 5MB song.
That equates to 12.5 minutes if you download using dial up
internet. All these figures are approximate and are assuming a 56k
modem connection, which never happens.
What
is dial up speed?
Maximum dial up
speed is 56k. There is a reason why there is a limit to dial up
speed. There
is also a limit as to how much electric power can be used to transmit
analog signals over conventional telephone lines. The federal
communications commission imposed a power limit to prevent a
phenomenon known as"cross talk".
If you've ever
talked on the
phone
and heard someone else faintly talking or a fax tone in the
background,
thats cross talk. If too much power were used
during data transmission, "cross talk" would increase between
adjacent phone lines.
As a result
additional erroneous data would be created during
transmission and
defeat the purpose of increasing signal strength to
achieve a
higher dial
up connection
speed.
This
signal to noise ratio
is known
as Shannon's limit.
Assuming all computers,
modems, telephone lines etc are working flawlessly,
Shannon's
limit
for computers communicating with each other over a
dial up
network is
56k.
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Prior to 2002 the
modem speed limit in the united states
was
53k. Also, there is still alot of information on
the
internet suggesting that the limit still remains at 53k. Here is a link
explaining modem speed limit was officially raised to 56k since 2002.
Current
dial up speed limit
Regardless if the speed limit is 53k or 56k, the maximum
dial up modem connection speed is
always unattainable. To reach a connection speed close to
56k,
you'd really have to be at your internet service provider and
get
the telephone lines out of the loop entirely. If you're only connecting
at 33.6k or less, your residential telephone line could be
emanating from a repeater. |
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