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From: lauren@vortex.UUCP (Lauren Weinstein)
Newsgroups: net.news
Subject: receiving vs. sending satellite netnews
Message-ID: <475@vortex.UUCP>
Date: Tue, 18-Dec-84 17:50:20 EST
Article-I.D.: vortex.475
Posted: Tue Dec 18 17:50:20 1984
Date-Received: Fri, 21-Dec-84 02:33:23 EST
Organization: Vortex Technology, Los Angeles
Lines: 36

[Technical sidenote: the reason that tuning for cabletext is so
critical is that the ideal tuning point for receiving the megabit data
streams for cabletext is often not the same as for receiving the best picture.
One of the very tricky constraints of cabletext is the balancing act 
regarding the 0 and 1 video levels that are chosen (and must be tracked
through all sorts of conditions) to avoid interference with the retrace
on the main TV picture -- particularly on older TV's.  If the video
levels sent for data are not chosen very carefully, you get buzzing
and even visual interference on the picture.  The end result is that
0 and 1 are much closer together than one would ideally like, and 
the decoders have to be pretty sophisticated to track the fairly
small variation between 0 and 1 (which tends to wobble with time)
accurately.  The custom IC's that are used for this are usually
in a bizarre configuraton that continuously tracks both sync and 
the current 0/1 levels, and adaptively slices in the middle (on a
changing basis) to try get the best data it can.  Especially in the light
of the damage that many cable companies do to their signals, this
tracking gets pretty messy and it must always be done at full video speeds.]

---

The current visualization is that people will post to the groups
that move on stargate just as they do now to moderated groups.
In fact, it is presumed that some of the moderated groups can be
fed pretty much "as is" to stargate.  Ideally, if the project grew,
there would be more mail paths created toward those moderators.
The moderators do the actual posting (mostly via direct calls)
to stargate.  So, to the extent that this technique is used, a given
message only has to traverse a single mail path to the moderator and
thence to stargate, not be broadcast all over the net by phone.
Since any given site RECEIVES *much* more news than it itself
generates, the high bandwidth receive, lower bandwidth send nature 
of this plan would seem to fit well into the traffic patterns
we'd expect.

--Lauren--