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DEFCON WiFi Shootout Winners Set A Land Record
bscience writes "While attending the DEFCON 12 convention this past weekend I had the chance to see the standing ovation a group of 19 year olds received for establishing a 55.1 mile unamplified WiFi connection!" A snippet from the Wired story linked there: "Mobile warriors having trouble making a wireless connection across the hall might want to give some Ohio teens a call. This weekend they were able to make a 55-mile Wi-Fi connection. ... They might have achieved an even greater distance, Justin Rigling said, "but there was no road left."" (Here's the post from a few weeks back about the competition.)
I don't get this. I've got a smallish house, but need two APs to cover it. I guess I'm considerably less directional, but still?!
Maybe these competitions could open up a second record of the largest diameter of coverage achieved. Maybe measured at four opposite points.
"Then, when they established that record, they turned off their amplifiers and broke the record for an unamplified connection at the same distance."
does that mean that the connection wasn't actually established unamplified... merely maintained?
I cant see why miles are used. Is it to make the achieved distance look longer?
I would guess it's because it's a competition held in the US. If you told someone there how many feet, yards, or meters it was then most people wouldn't really get how far that distance really it.
Evolution or ID?
It was in the United States. Miles were used for the same reason they are used on road signs and in cars - it is standard here right now, even if metrics is "better".
Ummm....perhaps because in the US, it seems like alot of you don't know how far a kilometer is.
I use metric though (Australia). Don't know how you USAnians do without it.
yeah they used the amplifiers to set it all up. they turned off the amplifiers. the little WinXP taskbar connection icon didn't disappear immediately. they all shouted "we r0x0r".
Apart from it being in the US where imperial (miles) is the standard. A mile is slightly longer than a kilometer therefore the number of miles is smaller than the same distance in Km.
But kilometres are smaller than miles so surely the distance seems shorter when displayed in miles. I think 55 miles is 88km. That said, I agree that it would make more sense to give the result in km. .
Mention the Lord of the Rings one more time and I'll more than likely kill you.
Or, if it was established at that distance, why wasn't the amplified distance longer than the non?
Because they didn't even max out the non-amplified distance. If you read the Slashdot blurb again it says They might have achieved an even greater distance, Justin Rigling said, "but there was no road left."
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- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
> Or, if it was established at that distance, why
> wasn't the amplified distance longer than the non?
As the article and summary pointed out, they ran out of road.
And yes, the unamplified distance was merely to maintain the connection and not establish it.
Either way, impressive.. especially as they would have likely gone farther if they had a good place to go to.
I touch computers in naughty places
Well, if someone parked outside my building, pointed a six foot dish at my office, and told me my wireless data needed encrypting, I'd probably freak out too.
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
Am I the only one who find it amusing that these guys roll in on a whim, break the record, win some stuff and immediately go hawk their equipment?
Some good old hacking spirit right there...
I touch computers in naughty places
Guess I have a shorter attention span than I thought... Either that or I just don't read the end of stories...
I live in an old-style "Stalin" house, some walls being more than 60cm (2ft) brick. standard OEM 802.11b "frog" won't shoot through 2 such walls. and that's a big pity :)
Sig. No Sig.
If by "slightly," you mean roughly 1.6, then yes.
About "a mile a slightly longer than a kilometer": last time I checked, 1 mile was 1.609 kilometer. What your kind of maths, you could also have said "a mile is slightly shorter than two kilometers". (Before the Dutch get confused: that dot is the seperator between 1 unit and 1/10th of a unit... not between thousands :-)
I would be interested to know what kind of transfer speed they got at that distance.
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1 mile = 1.609344 kilometers per Google.
They really should have reported it as 440.8 furlongs.
You are being MICROattacked, from various angles, in a SOFT manner.
Althought the article does not mention it, it does not seem like the hardware used to accomplish this was all that advanced.
If that is the case, their technology could be implemented in limited population density areas, tying back to the somewhat larger urban areas.
Take for example Iowa. There are many areas over 30 miles from any town larger than 15-30k.
Surprisingly enough, these 'large' towns have cable/phone (DSL) access.
So now the remote areas can be wifi attached to the bigger towns/cities and get the faster access (although 11b is not screaming it is better than modem).
For the (alike me, myself and I) imperial challanged:
Conclusion; achieved distance was 88.67km.
Hivemind harvest in progress..
1 mile = 1.609344 kilometers or for those of you who are into microelectronics it's 1609344000000 nanometers.
"It would be wrong to refuse to face the fact that everything is fundamentally sick and sad."
Seriously, at what stage does Planetary alignment, Solar Flares or wind direction start to have a bigger effect than technology??
I did quite a few Elec Eng subjects as part of my degree, and this stuff seems mind boggling.
[% slash_sig_val.text %]
And if you were performing this type of achivement underwater, you'd get..
;)
55.1 miles = 48488 fathom
1 fathom = 6 feet
Google is great for mathmatical conversions!
This year they faced only the heat and the absence of bathrooms and fresh beer for miles around.
that's just a tragedy.
I was there in the front row at the awards ceremony at DC12. These kids remind me of myself just a few years ago when I just picked up and moved to Vegas. Wasn't even sure if I had enough money for gas (good thing I was driving a Festiva @~45mpg). I guess this is a good case for those who say that all kids today are slackers.
For those who do not know, this contest was held in (and around) Vegas, when it was 110+ outside. These guys were dragging equipment up the side of a mountain to get this link. For those who would give these kids sh**, try dragging a 10ft dish(3.048 meters for you metric weenies) several hundred feet up a mountain, and then getting them aligned 55 miles apart, all in 110+f(43c) weather. There was no big 4x4's, they drove dads busted-a** minivan from Ohio for this. Sure, NASA could probably do better, but come'on, this was an amateur thing, and just something cool to do. No big prizes (they won like a couple-hundred bucks in Best Buy gift certs, and some gear).
If I had a had on, it would be off to these kids for some ingenuity and determination.
They didn't try to do so. My guess is that it's extremely difficult to align the dish with an extremely weak signal. The point of having the boosted signal was probably to help them initially align the dish. While it might be a real pain in the ass to set up such a connection without such assistance, once the dishes are aligned, apparently it's possible to run without amplification.
May we never see th
Miles on the speedometer, miles on the road signs, and 55 mph is a common speed limit, so that 55 mile record means I could drive about an hour away and still get the signal, which in Ohio would be the complete middle of nowhere! Of course, in Ohio it doesn't even matter where you start from, if you drive for exactly one hour in the same direction at 55 mph you will be in the middle of nowhere.
stuff |
55 mile? Huh! I can make 25000 mile (=40000Km) WiFi-connection.
I grew up in a metric society. I used to think metric units were superior until I lived in the US for a while, and found myself doing plenty of carpentry and DIY stuff where the most common units are inches and feet. I think the subdivision of a foot into 12 inches is fantastic; it allows one to easily divide dimensions into thirds, something that's a PITA in the metric world. In addition, the canonical subdivision of the inch into powers of 2 (1/2, 1/4, 1/8...) is convenient as well.
Regarding your point about doing without metric, note that virtually all building materials come in imperial sizes. There is no need to know metric units in that environment.
Tsunami -- You can't bring a good wave down!
"I expected the Rocky Mountains to be a little rockier than this."
"I was thinkin' the same thing. That John Denver's fulla shit, man."
They must have been using this cardm w_pcmcia_card_with_mmcx_connectors_2511-cd-plus-ex t2.htm
http://keenansystems.com/store/engenius_senao_200
Actually, Metric is the standard in the US since President Gerald R. Ford signed the Metric Conversion Act of 1975. However, conversion to metric was/is entirely voluntary (there used to be a 10 year deadline but it got dropped) so no-one actually switched.
The Metric Conversion Act of 1975 established the U.S. Metric Board to coordinate and plan the increasing use and voluntary conversion to the metric system. However, the Act was devoid of any target dates for metric conversion. In 1982 President Ronald Reagan disbanded the U.S. Metric Board and canceled its funding.
If there are any doubts about the sluggish pace of adopting the metric system in the US, the major US stock exchanges switched from fractions to decimals a scant 3 years ago.
Speak truth to power.
You can't really beat a 5/8 wavelength groundplane, and they're easy to make. (at lower frequencies anyway, not sure about ghz)
What do you mean exactly, as you probably know Wifi IS GHz (2.4)? This is rather at the end of the range where it is interesting to build non-dish based antennas. At low frequencies, the structures tend to get very big (~wavelength, of course), and at higher freqs, construction tolerances kill you...
Z
Just like Windows is standard, and Apple is "better."
"What we have here is a failure to communicate"
The Warden, Cool Hand Luke
I used to think metric units were superior until I lived in the US for a while, and found myself doing plenty of carpentry and DIY stuff where the most common units are inches and feet. I think the subdivision of a foot into 12 inches is fantastic; [cut] Regarding your point about doing without metric, note that virtually all building materials come in imperial sizes. There is no need to know metric units in that environment.
That building materials come in imperial sizes is just a convention. In Europe they come in metrics, and where they don't, they should. Maybe imperial units are more conventient for building/DIY/whatever, but I fail to see their advantage for any kind of (scientific) calculation. Also, when converting dimensions, you never have to take into account strange factors like when going from inches to miles, just move the floating point (no bash intended).
Z
When we start talking about setting and breaking distance records using any type of RF, atmospheric conditions will undoubtedly play a factor. A phenomenon known as Tropospheric Ducting can redirect a short wavelength signal back down to earth, allowing further than line of sight communication.
While this would be great for setting communication record, it would not allow for long-term reliable communication.
Dan East
Better known as 318230.
From the article:
Wired magazine helped sponsor the contest.
What's the word? Irony? Misnomer?
"When it rains, it pours." --Morton's Salt
not a fraud, just that you are stupid.
Read thre article instead of sounding like a turets victim spouting stupidity from your face.
Fresnel means nothing in directed DISH communications.. they had approximately 200db of gain at BOTH ENDS plus there was a tiny issue of BEING ON A FRICKING MOUNTIAN for the Z end.
wow, your immense stupidity is blinding... The stupidness field you are generating is destorying the minds that are around you.
Being a former Cinci resident, I was a bit curious about these guys, and google-stalked them . . .
.
Looks like they all went to St. Xavier, a pretty well respected (in both athletics and academics) prep school.
Here's a picture of Ben when he was a junior, winning a theater award for sound production.
Meng's got a website here that's a bit outdated, but considering the projects were from his junior year in high school, rather impressive. Seems he was a HAM radio guy.
Running out of time, the first link I found for Justin Rigling was this link. One more connection to the guy, since I use to work for AK Steel. The little blurb about the scholarship does make him sound like a stereotypical geek (JETS, Science Olympiad, Robotics, Math, and Photography clubs, etc etc). A bit of a contrast to his sister. Not exactly what you'd expect from the son of a steelmaker . .
Okay, enough being a stalker . . .
Although, I would be interested to know the antenna gain and RF power they were using this years 55mi link. For most of us, unamplified is about 35mW give or take, but you can also get 200mW cards which will get you a whole lot more distance 'unamplified' than with the 35mW cards.
Then to get Effective Radiated Power (ERP) you need to know the antenna gain. Every 3 db of gain will double your power. 100mw from your transmitter into a 3db antenna will give you 200mw output, assuming you have 0db cable loss.
So if they were feeding 200mW into a 23db (example figure) dish they would have a focused beam putting out 200mW*2^(23/3) which is 40W. And if you're feeding it with a 35mW card, its still 7W.
Neat.
anyone know how the atmospheric conditions played into this? seems to me that at 110 degrees of hot dry air, there's probably a lot less 'stuff' to push the signal through than say a hot steamy Wisconsin/Iowa/Minnesota/etc summer day. I know there's a point where they don't land planes because the air isn't thick enough to hold them up at landing speeds... so maybe with less air it dramatically increases the distance the signal can travel. They should put a cheap AP and dish on the ISS, we may not be able to war drive it from down here, but could, say, the Mars rover with a good dish?
As one of the judges, I can provide the GPS coordinates and you can use your favorite topo maps to determine if it is indeed possible. We will be putting up images and data on the contest page as well as www.adversarialsciencelab.net website sometime today.
I suppose you'd say that in Europe someone needs to cut a pie into ten equal slices? Get real.
Here's an article about using a surplus Primestar Dish to make an IEEE 802.11 wireless antenna http://www.wwc.edu/~frohro/Airport/Primestar/Prime star.html
e star/
Here's another one. http://www5.cs.cornell.edu/~eckstrom/802.11a/prim
As the first article notes, there are some FCC rules about antenna use within the US. Would the Defcon product be within these limits? The Wired article didn't seem to say.
i agree. this was an ok story when it was on WIRED YESTERDAY...good god, is slashdot just wired with comments?
Slashdot News: As serious as a busted rubber
I should've said "building materials in the US," since the parent comment was asking about Americans. Obviously, if they come in metric, knowing it will be much more useful. Still, having grown up in Europe, I found the decimal subdivision annoying.
I agree that it is a superior system for scientific applications, and I believe it a standard system in use by scientists, even in the US. However, we have a case of optimizing the most common case here; I think it makes sense to use whatever system of measures is most convenient for the majority of uses out there. Given that the scientific uses are probably miniscule compared to personal ones, I just don't see a good reason to switch.
Tsunami -- You can't bring a good wave down!
The link was AMPLIFIED and used parabolic/enhanced antenna designs. A well designed directional antenna will amplify the directed signal in the form of gain. However it is hardly unaided.
-AC
WWJD for a Klondike Bar?
I cant see why miles are used. Is it to make the achieved distance look longer? What "looks longer" 55 miles or 88 kilometers?
I never said the US stock exchanges going to decimal had anything to do with metric. It is just an example of how long it takes for the US institutions (government or otherwise) to switch from an old arcaic standard to a more modern one that is in line with the rest of the planet. Pieces of Eight are so pirate... and we all know zombies are the new pirate.
I suppose you'd say that in Europe someone needs to cut a pie into ten equal slices? Get real.
The real has already been gotten! I never said metric == decimal, it was a standard adoption comparison. No metric pies here, just real ones.
Cheers!Speak truth to power.
IIRC someone like Dr Bott or Kensington or thelike sells an antenna enhancer kit that fits on or into the tiBook cover. See if you can track one of those down.
https://app.box.com/WitthoftResume Code: https://github.com/cellocgw
From QST magazine (http://www.arrl.org/news/stories/2003/12/10/3/):
"Amateurs complete 82-mile two-way DSSS link on 2.4 GHz: ARRL High Speed Multimedia (HSMM) Working Group member Ken Cuddeback, NT7K, reports that his students at Weber State University in Ogden, Utah, recently completed two-way direct-sequence spread spectrum (DSSS) communication on 2.4 GHz over a distance of 82 miles. The WSU students--which include one ham, Brandon Checketts, KG4NZV, and several prospective licensees--broke the current world record of establishing a wireless link on 2.4 GHz with DSSS (using IEEE 802.11b "Wi-Fi" protocol). "Please join me in congratulating Ken and his students on this fantastic accomplishment!" said ARRL HSMM Working Group Chairman John Champa, K8OCL. Cuddeback says his students used PrimeStar dishes with unamplified Cisco Aironet 350 cards in each laptop. "We set up a NetMeeting session and transferred a 2.5 MB mp3 file successfully," he said. The Cisco Wi-Fi cards run about 100 mW."
Give a man a fish and you have fed him for today. Teach a man to fish, and he'll say "WHERE'S MY FISH, YOU IDIOT?"
You must be quite the rocket scientist, doing subdivision's of the 12 inches into a foot into fractions. Wow, no one would ever think that it would be easier then dividing something like that.. oh wait, you know it's even easier when it's power of 10's, unless you have a problem breaking a hundred dollar bill. While we are at it we should change the $10 bill to be $12 denominations, cause you can figure out the fractions of that really easily. Bring on the $6, $3 and the $1.50 bils too...
It just seems easier when you are doing carpentry work because everything is measured to imperial, since bright guys like you can't figure out metric and the 'power of 10', it seems that this will be the last place that any sort of change can take place.
Glad we have smart guys like you to sort us out.
I used to think metric units were superior until I lived in the US for a while, and found myself doing plenty of carpentry and DIY stuff where the most common units are inches and feet.
Except that a carpentry inch isn't an inch.
Unless "true dimensions" are called out, a 2x4, for example, is 1.5x3.5 inches. Strictly speaking,at least back when I was in Jr High shop, lumber measurements were +0,-0.5 inch to account for shrinkage as the wood dried after being cut.
Anyway, the point is that you may think you have the same unit (inches) but you don't -- sort of like troy vs avdp or US vs imperial.
https://app.box.com/WitthoftResume Code: https://github.com/cellocgw
Scientific uses such as splitting your plank into five equal parts, for example?
I'm a little more and less impressed their Trig is topnotch that's forsure. With WiFi it's all about the diamiter of your braudcasting dish, so yeah if you can get a 100M dish bruadcasting at ~2.4ghtz you'll get 60+ miles in a average city. The challenge is getting that saturation to be in circles not in just ONE fucking direction
I think the subdivision of a foot into 12 inches is fantastic; it allows one to easily divide dimensions into thirds, ...
Various mathematicians have explained why it would be so much better if we would switch to duodecimal (base 12) for all calculations. Somehow, I doubt if it will ever happen.
Another funny thing is that some linguists and historians have argued that there was a competition between bases 10 and 12 in Europe around 2000 years ago. It seems that there are a lot of Roman writings in which the numbers make more sense if you assume they were base 12. This starts with some docs where, for example, both iiii and iv are used, as well as viiii and ix. Why would they do this unless they thought that these were different numbers? And there are some historic dates that don't seem to be consistent in base 10, but make more sense in base 12.
The main linguistic evidence is that the Europoean languages all seem to have morphemes for the numbers from 1 to 12, and then the words become compound. It's not much, but it's one more item.
It must have created a bit of confusion, since some Romans apparently did count in base 10, while others probably used base 12.
But then the Arabs taught them a better way to write numbers, and it was all over for base 12.
It may not have actually mattered all that much anyway, since Roman trade and engineering was mostly carried out in Greek, and they had their own number notation that was a base-10 system, much like the notation used in Hebrew. It was a bit clumsy, but a lot better than Roman notation (and not as good as Arabic).
Those who do study history are doomed to stand helplessly by while everyone else repeats it.
Actually, Metric is the standard in the US since President Gerald R. Ford signed the Metric Conversion Act of 1975.
;-)
There was a funny NRP article back in the 1980s about the non-celebration of the 100th anniversary of the US going metric.
They had to explain, of course. It seems that the US, like most countries, has never actually had a legally-enforced standard system of measurements. Rather, there is a government bureau (whose name has changed several times) that defines official meanings to units of measurements. They basically just say "If you are to use units like ounces or grams or inches or meters, you must use our definitions of those units, else you'll be liable to charges of consumer fraud."
The official definitions of the units have changed occasionally, as newer and more precise means of measuring were developed. What happened in the 1880's is that the standards bureau decided that the most precise system at that time was the one in Paris. So they redefined all the Imperial units in terms of the metric units. At that time, the metric system became the basic legal units in the US, but all the other units were also legally defined. This situation has continued to this day.
So when you read that an inch is 2.54 cm, that's not an approximation. It is exact, because in the US, that has been the legal definition of an inch for about 125 years.
Some people have characterized the US system as an "extended metric system". They probably say or write this with an evil grin on their faces. We all know what "extended" means in such phrases.
(So "embrace and extend" wasn't invented by Microsoft; the US government has used it for over a century.
The closest that the US government has come to establishing SI units as a legal requirement has been in decreeing that certain products must be labelled in SI units. Most kinds of food and medicine are covered by this now, though they may also be labelled in Imperial units. Some manufacturers have gone to SI units only, for simplicity, but not very many. Usually the conversion has happened when there was an influx of imported goods. Thus, around half the cars sold in the US now come from other countries. It's a bother to have half your parts metric and half Imperial, so there has been a slow move to all-metric car parts. But the change has been slow.
We'll probably never change over completely.
Those who do study history are doomed to stand helplessly by while everyone else repeats it.
> Fresnel means nothing in directed DISH communications
Wrong. Why would you think the shape of the antenna would change physical laws? It doesn't.
I was on the N+I InteropNet Team in Las Vegas this year and one of the projects that I was able to play with was the Arruba/Airmagnet wireless rollout. It absolutely amazed me the number of vendors who didn't bother to contact the InteropNet admin ahead of time because they thought they could drag in their equipment, setup a 802.11b bridge and feed all their network needs wirelessly.
Even worse was that some of the vendors came in days before everybody else and, since their wireless bridge was working, refused to accept our FREE help in connecting directly to the network backbone. The day before the show floor opened all the newly arrived vendors flipped on their own wireless equipment and flooded the Las Vegas Convention Center with over 1200 distinct SSIDs across all channels. We scrambled to setup enough APs and track down problem spots for reconfiguration. While troubleshooting the chaos, I even heard one vendor say "well... why don't we just jack up our power and burn through all the interference!"
I absolutely applaud Defcon's wireless shootout, but I'm wondering if another segment of the test would be to subject the teams to the kind of interference that is common in a major metropolitan area. I would also love to see these guys switch over to 802.11a equipment which is vastly superior in dealing with interference.
Blackrobe "The Original TechnoWeenie!"
The connection was (re)established unamplified. The team had to shutdown the connection, tilt the antenna down, and climb a latter to remove the amp. Then of course, re-aim the antenna and try again.
All, check out http://www.wifi-shootout.com/home.html for the winning contest info (including GPS readings). We will be posting pictures soon.
I think the subdivision of a foot into 12 inches is fantastic; it allows one to easily divide dimensions into thirds, something that's a PITA in the metric world.
Yeah, because if I have a 25.4 cm board and I want thirds, it works out to a messy 8.46666... cm
But with imperial, that's a 10 inch board that so easily splits into pieces that are 3.3333... inches!
Fantastic! No, wait, the other thing. Moronic.
The unit conversions aren't as easy though, and how quickly can you tell me how many feet are in 3.8 miles? That's where metric comes out ahead.
I'd be fine with it if all imperial measurements were base-12, but it's the inconsistency between units that is why I don't like it.
it allows one to easily divide dimensions into thirds, something that's a PITA in the metric world
To be more accurate, you can't divide powers of ten by three. A third of 12cm is 4cm. A third of 10in is 3.333333 recurring inches.
Given that the scientific uses are probably miniscule compared to personal ones, I just don't see a good reason to switch.
While I still do not agree completely, I can see your point. For me (as an engineer) the advantages of the metric system are obvious, but I am aware that this vision may be (IS) biased. It is a bit difficult (for me) to guess how much more inconvenient the metric system would be in American daily (non-scientific) life. Personally I have never regretted it [the metric system], even when building stuff, or making cookbook recipes.
Something completely different: in the MS, there are some interesting relations, e.g. 1 liter of water equals about 1kg, which is very convenient for estimations of size and weight of most liquids. Are there similar relationships in the US?
Z
You probably know more about this that most - a comment in the previous Slashdot on the subject argued that at 200ft the horizon was at about 34 miles and that 2.4ghz waves don't follow the curvature of the earth, making that a top limit.
Did the team come up with different numbers? Perhaps the terrain has a significant elevation change?
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
The connection was first established with amplifiers in. We couldn't believe the signal strength (not sure if the Orinoco link client was reading right) - so we decided to test it unamplified as well. This involved a great deal more than just turning off a switch or pulling a power cord. We had to physically take apart each feed and this involved un-aiming the dish on the mountain just to get access to the feed. We (I was on the base camp side) then approximated the previous dish position and set it back. We pinged the remote computer and verified that we had a connection (1Mbps). We then did a remote desktop connect (both machines running XP) and took some screenshots and stuff after we passed the official test text between the two locations. We actually didn't even peak the signal (aim) on either dish after we had connected in either amplified or unamplified configurations. We figure we had about 34dBi antenna gain on each end, and other sources we found indicate the beamwidth should be about 4 degrees. We actually found the aiming to be much more tolerant than we had expected. On the final link we were so short on time that we didn't want to risk losing the connection to aim. Afterwards it was getting dark and we were already tearing down as the remote team drove back. -Andy