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DefCon WiFi Shootout Winner Announced
devn2k writes "At the first annual WiFi Shootout at DefCon in Las Vegas, Adversarial Science Lab won the contest to shoot a wireless signal across the Nevada desert, with a distance of 35.2196 miles. The antenna was built from metal poles, window screen mesh, cardboard, duct tape, and aluminum foil! According to the official contest page, the antenna was designed the night before the contest, its component parts were purchased for $98 at Home Depot, and the next day it was built completely from scratch in the desert, on the side of the mountain, in the rain."
Damn, I guess for US$98 you *can* change the weather :).
You forgot to add "...while walking uphill, in a blinding snowstorm..." followed by the obligatory "... and we liked it!".
I'm sure their success is attributed more to knowing what you are doing in a McGyver'ish way than simply hacking.
:)
That special knowledge that is the difference between the guy who buys dirt for a garden versus one who knows what to plant and mix in to make soil healthier.
Yeah, anyone can make a bomb with the proper chemicals, but can YOU do it with bubble gum, a piece of thread and a muffin?
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ping -f 255.255.255.255 # if only
it was built completely from scratch in the desert, on the side of the mountain, in the rain.
Why buy $98 worth of equipment at Home Depot and take the trouble of making tinfoil emitters when you can just dance to get rain in the desert?
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
Nobody expects the Adversarial Science Lab! Our main construction material is Metal Poles!
Metal poles and Window Screen Mesh!
Two construction materials! Our Two Weapons are Metal Poles, Window Screen Mesh, and Cardboard!
Our Three Main Construction Materials are Metal Poles, Window Screen Mesh, Cardboard! And Duct Tape!
Among our CHIEF building materials are such diverse materials as Metal Poles, Window Screen Mesh, Cardboard, Duct Tape, and Aluminum Foil!
Oh, bother. I'll come again.
Edward@Tomato - /home/Edward/ man woman
man: no entry for woman in the manual.
"Qua!?"
Notice that the shape of the winning antenna is a pyramid? There are a lot of theories regarding electromagnetism and the pyramid shape, including a bunch on how the ancient egyptians figured out how to utilize these electromagnetic properties, which is (supposedly) why the pyramids were built that way.
If you want to get kooky, it can also point to the extra terrestrial origins of ancient egyptian civilization.
Why do I h8 apple?
Alvarion is not Swedish (in fact, it's basically BreezeCom in new clothing), but the record was set with the help of SSC, the Swedish Space Corporation. Slashdot story link here.
Money for nothing, pix for free
Photo of anntena and team. Its look pretty cool.
-- ladies and gentlemen we are floating in space!
Easy!
You eat the muffin, stick the bubble gum over your rear end and fart until you have a nice big bubble full of explosive gas. You then poke the bit of thread into the bubble to act as a fuse. Done and ready to light.
Whilst the homemade winner was pretty good, im a bit suprised by some of the commercial entries.
eg: "Using a Stock Hyperlink 15dBi Omni at the base camp, and a stock Hyperlink 24dBi parabolic grid at the field site, with a confirmed distance of 10.1625 miles"
the WAFreenet (Perth, Western Australia) has several links of 18 to 22km (11.25 to 13.75 miles) - 30mW Clients with home modded 24dBi dishes (galaxy mods), connenecting to a 30mW AP with 14dB Waveguide. These links are about 8 - 10 SNR IIRC.
Our best is a link to the same AP from Rottnest island - 46 km! One connection was using an ipaq + cantenna with 2SNR, and another was with a modded satellite dish (overpowered at about 40dB EIRP), not sure of it's signal performance.
Several groups in the eastern states of Australia have achieved similar resulst.
If I only got 16km with a commercial 24dBi panel, i'd ask for my money back!
NASA scientists make fun of Slashdot users for unit conversion errors...
it was 9 million friggin' degrees all weekend
Farrenheight or centigrade?
Impressive yes, but typical of what ham radio operators do all the time. (Many of the ASL team members are hams, as was mentioned in the story.) We're always building equipment out of such mundane stuff as tuna fish cans and coat hangers, and making contacts around the world.
People (ahem) were flashing the firmware on their Senao cards to enable them to go up to 249 milliwatt. The entire area was bathed in 801.11 frequencies. Shit, I felt my hair stand up.
It was funny to see a thousand black-clad geeks waving their WiFi antennas in the air, trying to get a signal. If you didn't know better you would have thought it was some kind of dildo festival.
I'm sure their success is attributed more to knowing what you are doing in a McGyver'ish way than simply hacking.
Yeah, antennas don't respond well to guesswork.
Most people don't know that an antenna rings electrically the way a tuning fork rings mechanically. There's only a very limited frequency range that an antenna will handle well.
On top of that, as the frequency increases, radio waves behave more and more like light. And problems like stray capacitance and stray inductance - tiny values in farads and henries - become very important design considerations as the frequency increases.
But a well-designed amateur antenna can be very capable. The radio waves don't care if you make the elements out of silver encrusted canine feces, if they're the right lengths.
UHF TV band, around 450MHz. Design is extremely critical here. But by doing a little math first, I designed and built a 12-element Yagi (looks like an ordinary rooftop TV antenna but with more elements) which is tuned to channel 29. It's very directional, meaning I have to be pointed within a few degrees of the transmitter. But I can also watch WUTV Fox 29 from Buffalo, in Ottawa Canada, without shelling out for cable. Cost? Scrap of wood, old coat hanger wire trimmed to within 1/16" of the design dimensions, plastic tubing and clips to hold the elements to the board, old 75-300 ohm matching transformer gutted for its balun and soldered directly to the driven elements and feeding coax. Essentially free. Not waterproof, so it lives in my attic.
Fire and Meat. Yummy.
Here's part of an interesting discussion by ham radio people on VHF and UHF antennas in an area (Santa Cruz mountains) where reception is terrible.
The conclusions I draw are:
1. crappy antennas with amplifiers can work esp. if the amp is right next to the antenna (but it does have to get power- the Fubas on VWs are too short, but amplified, but they switched from separate power to "phantom" power over the RF lead that's unreliable)
2. putting the antenna outside on a tall mast is better than indoors, but in an attic might be an OK compromise
3. directional beats omni, but you'll need a rotator, a "farm" of antennas (feasible when there are only 3 or 4 xmitter sites as in SCruz) or you need to live somewhere (the end of a long peninsula?) where all the transmitter antennas are in the same direction
4. some commercial antennas are poorly designed, but good ones (Winegard) aren't that expensive- $90 - $220.
5. there are good VHF antenna designs for the ham bands near the TV bands and software that'll calculate element lengths & performance if you put in the different frequency
6. the emphasis in antenna design seems to be in UHF these days because HDTV uses that band & the set owners are the people that need the reception & have the $$ for the antenna & installation.
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If I didn't have satellite, I'd build a farm of stacked dipoles on the roof for VHF and buy a couple bowtie + screen antennas for UHF. Rotators are pain in the ass because the wind can blow the antenna out of alignment so all of your channel/angle settings need to be re-jiggered. They're also expensive.
It looks like 5G Wireless took the commercial category at the wifi shootout---14.8 mile coverage using their commercially available antenna. I'm not sure how widely known this is but Mcdonalds has a pilot in upstate NY according to this --feb 03 http://www.wirelessweek.com/index.asp?layout=artic le&articleid=CA274448
trades for a few pennies on the OTC bulletin board under FGWC
were any of these other wifi shootout companies public?
"CATEGORY 5 - Enhanced power, (omni or directional) commercially made antenna Base Camp GPS Coordinates: N36 39.698, W114 55.431 Field Site GPS Coordinates: N36 52.523, W114 57.389 At the base camp: Apple G4 800 MHz Notebook, with 10.2.6 ftpserver, 5G single panel AP, 3-foot tripod, 15-foot mast, angle ~150. At the field site: 4ms 4.26 Mbps, Toshiba Satellite 1135-s1552, P4M 2.0 GHz 512 meg ram, Windows XP Pro ftp command prompt only, 5G CPE 800 mW, 16 dbi circular polarity antenna, RSSI -67 dbm, Noise f