At NAB Gefen displayed a couple of long-overdue technologies for transmitting HDMI over longer distances, one wireless and one using coaxial cable. The first method is wireless using a frequency band between 3.3ghz to 3.5ghz, transmitting HDMI video over a distance of about 60 feet. We actually saw it transmitting over a distance of about 10 feet, but the video looked clean without any visible artifacts. Booth reps said that the maximum rez is 1080i, but the company's working on a 1080p version that may use a pair of transmitters to pump the higher resolution through the air. That's vapor so far, though—Gefen didn't have that 1080p version at the booth.

How did that second device, pumping HDMI over coax work?

Wa saw HDMI transmitting over a coaxial cable that was about 20 feet long, and that looked like it was unfettered by the transmission, too. HDMI over coax? Not a bad idea, letting you use longer runs (up to about 300 feet) of existing coaxial cable to transmit HDMI video and audio. Hey, that's long enough for even the biggest cribs. Boothsters say the coax tech "should be ready" to rock HDMI 1.3, though they haven't been able to test that yet. We've seen the wireless HDMI box available for pre-order, but the company says both the wireless and coax products will be available in July, each for around $700. – Charlie White and Curtis Joe Walker

2:15 PM on Tue Apr 17 2007
By Charlie White
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5 comments

Comments

dkoemans at 02:38 PM on 04/17/07
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doesn't my cable company already do this? i don't understand why it is said coax can't handle hi-def. my tv decodes hi-def signals from my cable company all day long. so logically, why do i need component/hdmi/vga from my hddvd/xbox/cable box, etc? coax can clearly handle the signal. i feel a conspiracy theory coming on.
TorkLugnutz at 03:03 PM on 04/17/07
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Well, dkoemans, the problem is that if you want to plug your HDMI component into your HDMI TV, you have to use an HDMI cable, which only come in limited lengths. There are a number of niche applications where having components 100m apart would be very useful, such as presentations, auditoriums, conference rooms and video distribution in retail, for example.
scarbrtj at 03:31 PM on 04/17/07
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Of corse coax can do hi-def. It's called HD-SDI, and has been widely available longer than HDMI. The HD-SDI spec even allows for embedded audio. The problem? The spec does not provide for encryption (but FYI--the spec for HDMI for display devices does mandate for allowing non-encrypted HDMI input). Gefen will likely just be using some sort of encryption--on the coax path--to keep the Powers happy, and eveything legal. HDMI handles 1.4 Gbps bandwidth, as does 75 ohm coax. If you had a non-encrypted HDMI source, you could use any of the available HDMI-->HD-SDI converters to pass HDMI across coax, today. But Gefen's solution will be slicker, less fidgety, embed your AC3, etc. etc.
Paul at 02:04 PM on 04/18/07
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Hell Yeah there's a conspiracy and its initials are: DRM.
chigga at 11:52 AM on 01/04/08
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yeah it's how manufacturers leech money off each new technology... coax can handle HD and more... but there's no hardware that will allow you to do so.. in this case it's almost like it's proprietory, requiring HDMI and component to be the only 2 standard (retail/consumer) available to the masses.