SPGDCM@CMSA.BERKELEY.EDU.UUCP (06/06/87)
MSG:FROM: SPGDCM --UCBCMSA TO: NETWORK --NETWORK 06/05/87 14:12:31
To: NETWORK --NETWORK Network Address
From: Doug Mosher <SPGDCM at UCBCMSA>
Title: MVS/Tandem Systems Manager (415)642-5823
Office: Evans 257, Univ. of California, Berkeley, CA 94720
Subject: phonevision
to: telecom@buit1.bu.edu
Phonevision (TV pic + audio phones) may hit us from a slightly different
angle.
A recent brochure from Datapoint notes their addition of MINX to their
Starbuilder network architecture.
MINX adds what they call "voice and full-motion video" to PC communication
networks. It appears that you add a Datapoint monitor-camera combination to
some sort of IBM PC; presumably the same monitor is used at other times for
high quality color graphic monitor use.
I have no idea what quality; certainly some teleconferencing video is limited
scan, like 2 per second or whatever; their term "full-motion" is interesting.
It seems to be a contest as more features are added to one's telephone and
networked pc workstation, until they meet in the middle. (But then at that
point you'll have TWO of them on every desk....)
Remembering also that the Datapoint co. stimulated the whole pc business in
the first place in about 1975 by their chip activity and the Intel 8004,
8008...
Thanks, Doug
phonevisionjanowsky@huma1.UUCP (06/08/87)
In article <8706052153.AA20677@jade.berkeley.edu> SPGDCM@CMSA.BERKELEY.EDU (Doug Mosher) writes: .> .> MINX adds what they call "voice and full-motion video" to PC communication .> networks. It appears that you add a Datapoint monitor-camera combination to .> some sort of IBM PC; presumably the same monitor is used at other times for .> high quality color graphic monitor use. .> .> I have no idea what quality; certainly some teleconferencing video is .> limited scan, like 2 per second or whatever; their term "full-motion" .> is interesting. I believe that data compression techniques allow something like "full-motion" video. When you're speaking (for example) your lips move but most of the tv screen remains constant -- and thus only the lips need to be re- transmitted. Of course this is a gross oversimplification, but... Steve Janowsky (janowsky@huma1.harvard.edu ...harvard!huma1!janowsky)
mgrant@MIMSY.UMD.EDU.UUCP (06/10/87)
I have seen picture-phones working on the Switched-56 network (AT&T's product that provides 56kbps end to end), the voice went over a seperate longdistance line. I can asure you that the quality of each individual frame was superb, but the network delay and jittering made it almost worthless. I also experienced a picture-phone link over T1, (albeit, to the next room, but still T1 (T1 is 1.544 Mbps)). I have to say that this was both crystal clear, and almost undetectable from full video. If the person turned their head real quick, the screen blured, but the action didn't stop as with the switched-56 service. The T1 service also carried voice as well. This service I could use. If it wasn't so dang expensive! I also don't think there is a switched T1 yet, atleast not one that can be dialed by the user. Anyone know anything different? -Mike p.s. according to the AT&T person I talked to at length, they can now provide full T1 over 1 twisted pair, (I thought it was 2), to most customers in the nation. Most subscribers are apparently not that far from their CO. If there is interest, I will call my friend at AT&T back and badger her somemore.