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- From: johnh@macadammq.edu.au (John Haddy)
- Subject: Re: Dallas Video on Demand Test
- Message-ID: <1992Jul29.223335.16471@mailhost.ocs.mq.edu.au>
- Sender: johnh@macadam (John Haddy)
- Nntp-Posting-Host: macadam.mpce.mq.edu.au
- Organization: Macquarie University, School of Mathematics, Physics, Computing and Electronics
- References: <Bry4vz.HDF@andy.bgsu.edu> <l7a0qvINNr7m@appserv.Eng.Sun.COM>
- Date: Wed, 29 Jul 1992 22:33:35 GMT
- Lines: 46
-
- In article <l7a0qvINNr7m@appserv.Eng.Sun.COM>, bender@oobleck (Duke of Canterbury) writes:
- |> klopfens@andy.bgsu.edu (Bruce Klopfenstein) writes:
- |> :
- |> : According to the 13 July 1992 issue of TELEVISION DIGEST,
- |> : USA Video wants to test a video-on-demand service this fall
- |> : "using one of Southwestern Bell's 2 fiber testbed communities
- |> : outside Dallas." The technology was tested in SW Bell's lab
- |> : in St. Louis in June. A compressed movie can be delivered to
- |> : the home in 3 1/2 minutes using the "equivalent of less than
- |> : 10 standard video channels for rapid delivery."
- |>
- Note the above line! 10 standard video channels, not telephone channels.
-
- |> How is this possible? Didn't we learn on the net last month that it is
- |> theoretically impossible to transmit a full motion video signal over
- |> telephone facilities because the SWR would cause the television receiver to
- |> explode into oblivion :-)?
- |>
- |> Well, didn't we?
- |>
- |> mike
-
- Modern codec technology obviously plays a big part. Somebody else on the net can
- probably provide up-to-date information on the magnitude of compression being
- achieved.
-
- Most likely, the first quoted word, "equivalent", is the key here. I can't
- imagine a new major research effort such as video-on-demand locking itself into
- ancient technology i.e. analogue transmission. More likely, the system would
- use channel aggregation techniques on multiple digital channels.
-
- The quotation states the use of SW Bell's fibre testbed communities - does
- anybody in networld know how old these are? If they're more than a couple of
- years old then they may well be broadband FDM analogue fibres. If they are
- younger, there's a great chance that high speed digital links are in use.
-
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