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RE: bandwidth

2002-08-19 02:01:19
Bill,

The Plain Old Telephone System (POTS) is limited to a bandwidth of around 3000 
Hertz (usually 300-3400 Hertz).
We can use that technology to transport baudrates of 300, 600, 1200 or 2400 
bauds.

Thanks to different modulation techniques, we can use those 2400 bauds to 
transport 14400 or 28800 bits per second.
Thanks to some compression techniques, we can even reach 56000 bits per second.

To exceed that limit, we need to replace POTS with (e.g.) ISDN (2x64kbps), CATV 
(256-512kbps), ADSL (1Mbps)...
The bitrate you mention (100-200 bits per second) is very, very low.

Notice that the datarates I mention are not limited by the technology but by 
commercial decisions.
CATV can provide 14Mbps, 25Mbps, etc. ADSL can provide 2Mbps. Other DSL 
technologies can reach 56Mbps.
Now, the providers usually limit the maximum datarate to lower values (the ones 
hereabove mentioned).

E.T.

-----Original Message-----
From: Bill Cunningham [mailto:billcu(_at_)citynet(_dot_)net] 
Sent: lundi 19 août 2002 3:44
To: ietf(_at_)ietf(_dot_)org
Subject: bandwidth


I have a 56k v.90 and v.92 modem. 56 bps is baud per second correct, not bits 
per second. Of course the phone line will only handle 52k but is the difference 
between v.90 and v.92 in bits no baud?
    High speed bandwidth is coming to my area. Speeds such as 100-200 bps will 
be available. This sounds like DSL to me because we already have cable modems.



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