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Re[2]: IRC Server
guy keren <choo@actcom.co.il> wrote:
> furthermore - a 14,400 bps modem still works at 2400 BAUD. even the
> 28,800 modems work at 2400 BAUD. the theoreticall limit for modems
> that are allowed to make a delay of up to 2 bits in transmission is
> a bit below 32,000 bps (not INCLUDING data compression done on top of
> that), so faster modems requiere one of two:
> 1. allow for a higher delay.
>From 'The Free On-line Dictionary of Computing':
********************************************************************************
* ... each baud may carry
* between 1 and 16 bits depending on the coding (eg. QAM). Where data is
* transmitted as packets, eg. characters, the actual "data rate" of a channel is
*
* R * D / P
*
*
*
* where R is the "raw" rate in bits per second (including packet overhead), D is
* the
* number of data bits in a packet and P is the total number of bits in a packet.
********************************************************************************
Thus, maximum RAW i/o you can get with 2400 baud is 2400*16=38,400 bps - not
much better that mentioned 32,000.
> 2. (what is usually done) use a line with a larger bandwidth
> (phone lines give you a range of 3.6Khz for data transmission -
> remove this limit, and you can get to MUCH MUCH higher rates on
> these SAME phisical lines). as far as i know, this is an
> international standard, and not just a bezeq standard - the 3.6KHz
> thingy. i might also be wrong, since i only assume so).
Could you please explain, how with 3.6kHz bandwith lines folks get something
better than 3600 bps (probably, times some factor near 1, depending on bandwith
definition)?!
Evgeny
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/ Evgeny Stambulchik <fnevgeny@plasma-gate.weizmann.ac.il> ====== \
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