At 15:11 03/29/99 -0800, William Chops Westfield wrote:
>    how do you mean that? 28.8kbps is no bandwidth, though it may use one...
>
>Huh?  28.8kbps is exactly a bandwidth.  A normal phone conversation uses
>56kbps of digital bandwidth on a TDM "fabric" between the speaker and
>listener.

i thought of bandwidth more in the traditional sense of "width of a
frequency band", where the 28.8kbps would be transmitted in 3 point
something kHz bandwidth. (BTW, the data rate on a PSTN digital channel is
64kbps: 8000 8bit samples/s -- the 56kbps on a V.90 transmission stem
primarily from limitations of the DAC on the receiver side.)


>Yes, to get 8k and reasonable quality you need pretty good compression.  I
>don't know about "serious" compression, though

in my use of the word, "serious" compression was meant to mean "pretty
good" compression. (seemingly, this expression is not quite clear to
everyone, but excuse me: i'm no native speaker, and i may use every now and
then expressions which need a "good will" interpretation.)

>you can buy chips (not too expensive, either) that will change
>voice into an 8kbps bitstream.

know of any?

ge