🚀 go-pugleaf

In article <4095@utcsri.UUCP>, gclark@utcsri.UUCP (Graeme Clark) writes:
> I'm curious about the claims of a particular LAN design (FDDI) which
> talk about sending video data and digital data over the same baseband
> channel.  Can someone tell what bit rate would be required to encode
> a standard colour TV brodcast channel?  How about monochrome?
> Thanks.
> Graeme Clark -- Dept. of Computer Science, Univ. of Toronto, Canada M5S 1A4

According to a recent talk I attended FDDI is designed for a baud rate of
125Mhz and a bit rate of 100Mhz (For those who don't know the differences
between bauds and bits, you should expect 100 million bits to come out
of the wire every second) The 'dot' clock on a video interface that produces
NTSC video (60Hz, 262.5 line frames interlaced, 640 dot horizontal resolution)
are on the order of about 10Mhz. Multiply that by some factor to color
(pixels being the multibit critters that they are) and you can get a raw
bit rate. Simplistically you would also be transmitting the black around
the edges too. However there are a number of schemes that reduce this
considerably. So for a  ball park I would guess it would take an aggregate
throughput of about 40Mbits/sec to get a "standard" colour picture out
the other end. That's definitly moving right along. 'Course it would
be great fun to mount HBO from a server on ones desktop :-) 

-- 
--Chuck McManis
uucp: {anywhere}!sun!cmcmanis   BIX: cmcmanis  ARPAnet: cmcmanis@sun.com
These opinions are my own and no one elses, but you knew that didn't you.