🚀 go-pugleaf

I been reading the October 1988 issue of Electronics (A VNU Business public-
ation).  The October issue is a special issue on the technology outlook.

There was a section on ISDN

"... As a result, areas of ISDN services served only by ISDN switches will pre-
dominate through the mid-1990s at least.

	In the meantime, complementary technologies are taking a crack at
delivering ISDN like services over the installed central-office switching 
systems that were primarily envisioned for voice and low speed data.  Not
supprisingly, these data-over-voice technologies depend on multiplexing
signals and must be face the difficult trade-off between attaining a useful
local-loop transmission distance and the level of interference between voice
and and data channels.  A breakthrough is likely next year with Integrated
Network Corps....system, which delivers 19.2Kbits/s of encoded digital data
capacity with simultaneous voice over dial up lines."

Question is how are they going to achieve this on dial up lines ?
(Should I throw out my modem now ?)

The article goes on

"	Instead of using frequency-key-shifting techniques, the Bridgewater
, N.J. company's patented algorithm reduces energy in the voice frequency
band by using partial response alternate-mark-in version sinusoidal coding
techniques ... minimizing energy overlap between the 4KHz voice and remainder
56KHz baseband for data...interference-free over a 18000ft local loop -
compared to the 6000ft max of data over voice technologies."

Frequency-key-shifting ?  Is that what is currently used by modems ?
What is alternate-mark-in coding technique ?  Why do they talk about 4KHz voice
and 56KHz baseband for data when current local loop is really 4KHz voice ?
Is data-over-voice meaning modem technologies ?

-- 
Anthony Lee (Humble PhD student) (alias Doctor(Time Lord))
ACSnet:	anthony@uqcspe.cs.uq.oz		TEL: (07) 3712651
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