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- Newsgroups: bit.listserv.edtech
- Approved: NETNEWS@AUVM.AMERICAN.EDU
- Date: Tue, 15 Dec 1992 16:51:29 EST
- Sender: EDTECH - Educational Technology <EDTECH@OHSTVMA.BITNET>
- From: Edward Caffarella <ecaffare@dijkstra.UnivNorthCo.EDU>
- Subject: compressed video
- Lines: 41
-
- I am responding to the recent question regarding compressed video
- applications in education and training.
-
- The major standard for moving compressed video television images
- is the Px64 standard. This is a worldwide set of standards for
- the transmission of compressed video images and the associated
- switching. All major equipment companies now support this
- standard. Any machine supporting this standard can communicate
- with any other machine using the standard regardless of the
- manufacturer. Many vendors supply their own protocols in
- addition to the Px64 standard.
-
- The carrier for the signal is less important now than it was a
- couple of years ago. The signal can be carried over several
- different media depending upon the local needs. The most common
- is over T-1 telephone service. We did some testing last year and
- found that 1/4 T-1 (384 Kb) was very adequate for instructional
- purposes. DS3 service is probably overkill for compressed video
- unless you can justify the bandwidth for other purposes. Another
- alternative for you may be the use of an inverse multiplexer.
- This unit allows the user to dial up multiple lines so that you can
- build bandwidth on demand. This alternative works well in areas
- served by digital exchanges.
-
- The major equipment vendors for compressed video are:
- VideoTelCom, Austin, Texas
- Picturetel, Peabody, Mass.
- Compression Labs, San Jose, CA
-
- This is a quick overview of compressed video. Please contact me
- if you have further questions.
- oooOOOOOOOOOOO
- o ____ :::::::::::::::::: :::::::::::::::::: __|-----|__
- Y_,_|[]| --++++++ |[][][][][][][][]| |[][][][][][][][]| | [] [] |
- {|_|_|__|;|______|;|________________|;|________________|;|_________|;
- /oo--OO oo oo oo oo oo oo oo oo oo oo oo oo
- ---------------------------------------------------------------------
- Ed Caffarella Professor of Educational Technology
- ECAFFARE@dijkstra.UnivNorthCo.EDU College of Education
- voice 303-351-2687 University of Northern Colorado
- FAX 303-351-2377 Greeley, CO 80639
-