Fire Wire Grows Like Wildfire
Stumped as usual about how to start this column, I recently
searched my laptop to find out how many times I've written the words "fire wire"
this year. The answer startled me: a rousing 48, culled from stories, proposed stories and
notes about stories for this publication.
As a reference, "DOCSIS" (Data Over Cable
Service/Interoperability Specification, for cable modems) weighed in at 107, and
"digital" at 401.
Fire wire has many aliases, the most stuffily technical of
which is "IEEE 1394." Plus, a large number of links exist, both as subsets and
supersets, between fire wire and other gibberish acronyms.
To name two, there's OpenCable's "HDNI" (which
has nothing whatsoever to do with high-definition anything, instead standing for
"Home Digital Network Interface); and "HAVi" (Home Audio Video interface),
the consumer-electronics industry's stab at fire wire.
If you look past those nuances, fire wire represents three
things. First, it's the technical underpinnings of a connector, in terms of which pins go
to which circuits. Second, it's the definition of the wire that strings between those
connectors. And third, it's the language -- or "protocol," as engineers like to
say -- that tells digital information what to do and where to go as it travels over that
wire to those connectors.
Sexy, no? Maybe not, but neither is fire wire any cause to
glaze over with jargon oversaturation. Actually, fire wire is a fairly important thing to
know, and not all that difficult to lump into understandable categories. It's also one of
those simmering issues that shouldn't be left for other industries to decide.
At the least, we should all be grateful that it has a
clever name -- one that implies data sizzling over a wire at speeds so fast that it sets
the wire afire. You have Apple Computer Inc. to thank for that; the Mac people originated
What does a broadband-network operator need to know about
fire wire and how it relates to the digital business?
According to MSO engineering gurus, fire wire is the
foundation for some of the ongoing specifications that OpenCable is writing. Specifically,
OpenCable is working on HDNI, which is a technique for sending compressed
high-definition-TV picture information at a rate of 19 megabits per second from the
digital set-top and the TV.
So what, you say? Although fire wire is fast, it's not yet
fast enough to carry uncompressed HDTV pictures, which run at roughly 1.2 gigabits per
second. That's where HDNI comes in: HDNI is a way to rearrange some of the signal
processing from the set-top to the TV, lessening the haul on the wire. Not coincidentally,
moving those processors (such as MPEG-2 decoders) into the display device lowers the cost.
Plus, fire wire is currently the only way to move
copy-protected digital material from the set-top to the TV. That's because an analog
version of copy protection isn't available for uncompressed HDTV pictures.
That last bit has a big impact on what kinds of HDTV
programming cable operators will be able to deliver. Hollywood types, not surprisingly,
don't really want pristine-quality images to move around freely over a wire, for fear that
they could be stolen fairly easily.
Interestingly, some personal computers already have 1394
connections, without copy protection, which is a potential problem.
Then there's the whole issue of moving digital information
around between different devices in the house. Engineers call this "home-area
networking," or HAN. It's the stuff, theoretically, that will let you check on your
sleeping child from your neighbor's TV, because your digital camera is hooked over fire
wire to your set-top, which has a built-in cable modem.
One closing thought: Fire wire falls into the
cross-industry zone. As such, there are many other companies harvesting their own
fire-wire interests. Don't let this one get away from you: Urge your technical teams to
get involved, especially when it comes time to vote on standards.
That way, I won't have to write a column in a few years
describing the who-knows-what ugly offshoot of a consumer-electronics-induced
"solution" that unknowingly or otherwise thwarts some cable-provided service.