[comp.dcom.telecom] 7 khz Technology for ISDN

CB06049@uafsysb.bitnet (Colin Byers) (10/07/89)

I have been reading in the Sept 25, 1989 Communications Week on page
74 about the latest sound improvement for ISDN from AT&T.

My questions are:

1) How does making a 7khz signal improve the sound quality ?
   (I know about bandwidth but thought someone could go into
    more depth than the article covered...)

2) Why is getting a switched 56-kbps line so expensive relative to
   say a 64-kbps line?

3) What difficulties are preventing Bell from implementing this?

Thanks again,

Colin
Acknowledge-To: <CB06049@UAFSYSB>

vtaft@hpindda.hp.com (Vladimir Taft) (10/14/89)

7 kHz audio standard uses a more sophisticated encoding algorithm
which provides better quality than the older standard (8-bit PCM) at
the same bit rate of 64 Kbps.

As far as the rest of your questions - sorry, I have not seen the article.

Vladimir Taft