Coax making a comeback?
by Kevin C. Tofel 
posted Sep 14th 2005 at 7:09PM
Call it FireWire or call it IEEE-1394, but whatever name you use will describe what may bring the lowly coaxial cable back into the fold. That's right, coax could leap ahead of all of the other audio and video connections out there: component, composite, S-Video, DVI and even HDMI! How is this possible you ask? It turns out that a task group was just formed by the 1394 Trade Association (not to be confused with The Trade Federation, who were puppets controlled by an evil Sith Lord.).The task of the group is to create a simple "native 1394 over coax specification" in early 2006. This could mean FireWire speeds over regular coax cable, paving the way for bandwidth of up to 800 Megabits per second (Mbps). For comparison, an HDTV digital transmission can use up to 19.2 Mbps, meaning that a cable operator could theoretically pump 40 full HDTV channels on a single cable. Seems like a good use for all of the coax laid down over the past 25 years, no?
Reader Comments (Page 1 of 1)
Ryan @ Sep 14th 2005 7:50PM
Actually quite a bit more than 40 channels if the video was compressed in MPEG4 (like DirectTV plans to do).
Kevin C. Tofel @ Sep 14th 2005 7:50PM
That's true. My example is for uncompressed HDTV. With MPEG-2 or MPEG-4, you could fit much more programming "in the pipe."
Kevin @ Sep 15th 2005 3:40PM
HD-SDI is carried over a "lowly coaxial cable" with bitrates of around 1.5Gbps.
Cecil @ Sep 15th 2005 3:47PM
An HD signal at 19.2 Mbps IS compressed with MPEG-2.
Kevin C. Tofel @ Sep 16th 2005 2:09PM
My bad (again) Cecil! For some reason I had 8-VSB modulation on the brain when I was writing and responding. I completely forgot the other half of the current HDTV equation = MPEG-2. HDTV is a two part transmission: modulation AND compression. Thanks for the catch!
I'm surprised nobody caught my other faux pas: I wrote 19.2 Mbps when in fact, it would be more accurate to say 19.39 Mbps for an HD stream. ;)