Researchers Set World Record For Wireless Data Transmission http://phys.org/news/2016-05-world-terrestrial-radio-transmission.html Imagine being able to wirelessly transfer the entire contents of a DVD in less than 10 seconds. Researchers from the University of Stuttgart and the Fraunhofer Institute for Applied Solid State Physics have shown it’s possible by achieving a world-record transmission for wireless data of 6Gbps over a distance of 37km, exceeding the state-of-the-art by a factor of 10, according to the researchers. The discovery could supply 250 Internet connections with 24Mbps ADSL or serve as a cost-effective replacement for deploying optical fiber in cases of crises and catastrophe. The system uses efficient transmitters and receivers at a radio frequency of 71 to 76 GHz in what’s branded as the “E band” typically used for terrestrial and satellite broadcasting. The researchers note that is the only frequency range where the required high effective bandwidths are available, allowing for the incredibly fast data rates. Such a powerful transmission requires efficient transmitters and receivers, for which the researchers used fully monolithically integrated millimeter wave circuits, or MMICs. ==== In the United States, 71-76 GHz is allocated to: Fixed Microwave, Fixed Satellite, and Millimeter Wave Service (MMS). Amateur Radio Frequency Allocations, above 35 GHz: 47-47.2, 76-81, 122.25-123, 134-141, 241-250 GHz. Credit: © Photo Jörg Eisenbeis, KIT
I guess we could use all of the entire HF spectrum at one time to do the same. Imagine if we had a setup where a low power digital signal format had enough error correction so no matter whoever else is broadcasting where or part of the HF spectrum is not carrying the DX mail, that the data gets through. Could such a signal be made that would not unduly interfere with all HF users, a "stealth" signal so to speak? Could massive frequency hopping be part of the solution? How many Kb's or Gb's could be moved? Rick
We used to play with Lockeed Martin and other aerospace and defense companies with very high frequency concept gear all the time when I was in the Navy. Had one team of Lockheed engineers fly out to our destroyer in the middle of the Pacific back in 2004 I think. Anyways, they installed a few dishes and domes on the yard arms of the mast. Down in radio we were getting 3-400 mbps transfer rates to satellites back down to Earth at the Lockheed offices in California. I want to say I remember it being around 125 GHZ or something like that. It was really high and really fast. It was future conception for high speed internet and secure battlefield intelligence and communication for warships and air planes while deployed over seas. Cool stuff. I have been out for 8 years now or so and I am sure they are in the gbit range of data transfer on ships now. Glad to see that colleges are pushing the boundaries of wireless more and more. Heck I still think that my Galaxy Note 7 over LTE getting 90 mbps is still flying fast haha
Well that is not to say that my first internet connection was a 14.4kbps modem to a bulletin board service. I think that was around 1994 or something.
Technically, not very many by today's standards. At the risk of being somewhat obvious, all of HF is less than 30 megahertz wide. The bandwidth used for this test was 5 gigahertz, give or take a wiggle on the o'scope. Coming up with a specific number that could be passed over HF would involve a host of assumptions about the technology used, and the technical hurdles that would need to be overcome just from the different wavelengths involved. I could see a massive discone antenna might allow dealing with some of that. 'Back of the envelope' guesswork would put the available transfer rate at considerably less than one of the wifi channels in your home router.
COCO Was first on my block with an acoustic couple modem from Radio Shack - still have it in the box along with the TRS 80 COCO. It really got the attention of the neighbors back then.
In that stage of the game , the whole world was just learning to crawl ..... It was the best we HAD at the time .... We now are just learning how to stand up ..... Walking , without falling down , is in the future .... It is a progression ...... JMHO ...... JB
Yes, I know the difference between Megs and Gigs...LOL! To me the objective was to use HF in order to get some propagation action going. You won't have that in the very high frequencies, at the risk of being somewhat obvious...hi-hi! Discone antennas. Now that's a good suggestion. Rick
I think we would better be served if the FCC and ITU would focus efforts on removing the Noise Sources in the HF band.
Rick, Yes, no offense intended, I took this as a somewhat literal question in part because this idea is still being played with. The ARRL has that request up to the FCC to change from a symbol limit to a 2.8khz bandwidth limit for digital in the HF bands. It's still a tiny section of bandwidth, but the thought is that with modern modulation methods and error correction (as you mentioned) it would be possible to achieve genuinely useful transfer rates.
This was mine that I used back in the BBS days in '83. Stock photo... I have to dig mine up. Yep 300baud acoustic coupler(sp). ...DOUG KD4mOJ
I fear that will never happen. Even before "globalization" (internet, worldwide shipping like DHL, etc), it was tough to keep up with all the noise sources. That is a time when UL labs meant something. Now, with globalization and rapid shipping competition, the borders are effectively "Swiss Cheese", and more crap flows into the country at a rate 100x faster than any gov inspection/enforcement agency can hope to notice. HF noise sources, in my prediction, will only continue to climb. At some point in the future, we may need to use modes that are less affected by them. Or maybe I go off and start finally playing with all of our microwave allocation
