125-Mile WiFi Connection
Jason Striegel writes "Team iFibre Redwire smashed the WiFi distance record, successfully linking a distance of over 125 miles at this year's DefCon WiFi Shootout. They maintained a full 11Mbit unamplified connection for 3 hours using Z-com 300mw PCMCIA cards, surplus satellite dishes, Linux, and a great deal of hacker ingenuity. The best part: yesterday afternoon they said that they expect this rig would work at distances of over 300 miles. Here's additional team info, a couple pictures of one of their rigs, and some more technical details." I still wish I could find truly out-of-the-box Linux-friendly USB adapters, so I could get some tiny fraction of this distance, cheap.
Now I can buy a bigger house!
And sometimes I lose signal in my backyard :)
201.16800 km for us metric guys :)
hayalci
.. were they allowed to use those illegal cantennas? :)
...now all we have to pass through is (very likely to occur) incoming "using Wi-Fi causes brain tumor" FUD-campaign. And then off we go to 21st century wireless-networks world.
How are they going to wrap their wifi signal around the Earth, assuming that they don't have their own satellite?
I don't think ionospheric propogation is going to work at wifi frequencies. And you won't get 11 Mb/s at 27Mhz.
http://michaelsmith.id.au
2.12639285 x 10^-11 light years for us space-faring people. But we already have Wi-Fi anyway. Surrender your planet!
There is just no way they can maintain 300 miles/480km without using relay stations. Multi megawatt FM stations cannot get that range simply because the curvature of the earth causes the signal to disappear into space before reaching its destination. 125/200km is about the maximum range that is possible on frequencies much higher than HF, even with captain picard's private satellite link to france they are not going to get 480km out of it.
Disclaimer: On the other hand, I am kind of a psycho...
inCREASe your WIFI distance NOW!
Over-the-counter WIFI enhancers!
Make it go FARTHER!
If they can really increase the range they can just stay home and connect to Defcon from the top of their house.
Quality Hosting e3 Servers
At whatthehack there was someone telling about how he managed a 500 km connection (which is 311 miles says google)...
The 300-mile record will break the highest altitude Wi-Fi as well ;)
Tsunami -- You can't bring a good wave down!
"They're unsophisticated but reliable, and it's illegal to possess them," said Lozito of the Hi-Tech Crimes Task Force.
What the fuck is the world coming to? When did cantennas become illegal to possess??? Why are they illegal to possess? WTF???
Perhaps this could mean real internet connections for some Cuban citizens again. It's close enough to Florida, Mexico, and the Dominican Republic to make it feasable.
Not many would be able to make use of it, of course, but every bit helps when you're living under a government such as that.
And, what? I'm supposed to click on all the links, and just close the ones that don't actually contain the story I'm looking for? Oh right, this is slashdot, you won't want readers to be able to find the story, lest they discover the summaries are usually wrong, and criticize the editors for it...
,which is named "Team iFibre Redwire" is a rather spartan page about the group, and and not a link to the story.
/. is only slightly annoying usually, because most stories only have 2 links. Now, with about a dozen terribly non-descript links, it's getting awfully bad, making several recent /. stories unreadable.
Of course a link named "DefCon WiFi Shootout" wouldn't be the story, right? It would be info about the event, right? After all, the first link
Bad editing on
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
Are there any hacks yet for wimax, that should even be better.
My wife's sketchblog Blob[p]: Gastrono-me
Given some amplifiers and big dishes you could do moon bounce. Of course the time it takes the signal to go up and down again could pose a bit of a problem.
How about line of sight at 300 mi. The formula is something like:
Rr = 1.2 * (Ht)**0.5
Where:
Rr = radar range in miles
Ht = Antenna height in feet
Since you could have two towers you would only have to get 150 miles each. The antennas would only have to be 11,000 feet high.
Troposcatter anyone?
They maintained a full 11Mbit unamplified connection for 3 hours
That is until the were slashdot'd
"If all the world's a stage, I want to operate the trap door." - Paul Beatty
So a single WiFi point atop a city's tallest building could provide the entire metro region with high speed wireless internet access (hswia)? If this feat can be reliably duplicated, even at a relatively high cost it will lead to a revolution. With just a hundred or so hardware modules 80%+ of the US's pop would have free hswia! It could be the highest impact innovation since the explosion of the internet itself. Certainly it would overshadow the rise of residential broadband access. All those cable and phone companies would have to get out of the data business (since it would be free) and get back to the cable and phone businesses.
The team's story and some more technical knowledge
-nick
So the UK guy who thought he was picking up his neighbors network, turned out it was actually this !
"Sweet llamas of the Bahamas !"
high altitude weather balloons?
"He who throws mud, loses ground." - proverb
This would be useful for many developing nations. No expansive infastructure required for internet connections in remote locations. Wondering when "wired" will have the article on the competition out. Also wondering what the power requirements for the entire setup are ie -- can the whole setup be run off of micro dams, solar power, etc.
Nice juxtaposition - this article immediately following the one about the UK prosecuting an illegal WiFi hijacker (article). What's next, one about how to secure your AP?
To a politician, one email equals one voter.
All communication for longer distances than so called line of sight communication is due to tropospheric propagation.
In summertime it is very common in areas of extreme high pressure condiftions. Today it might work just fine, tomorrowe no connection.
Best of luck with your experments!
Kalevi Nyman
SM0NTE
---
Hams get the neat ability to modify their equipment to pump out more power and use better/stringer/faster toys. (Legally)
This is also true when using cantennas.
Read up here for the commercial aspects:
http://www.michwave.com/bbnetwork/faq/fcc.htm
Here for the amateur side:
http://www.qrpis.org/~k3ng/ham_wisp.html
Yep, I never spell check.
More incorrect spellings can be found he
i think they connected to my "linksys" instead of theirs ;)
sarchasm
It's not difficult to find them: Google.com Search: Wifi Linux Usb Adaptor
1000 Furlongs for those resembling equidae here
They maintained a full 11Mbit unamplified connection for 3 hours using Z-com 300mw PCMCIA cards, surplus satellite dishes, Linux, and a great deal of hacker ingenuity.
Unamplified... with a satellite dish? How did that work out? That's one hell of a passive antenna.
They had corporate support to go to DefCon.
They used the VCom 325hp+ PCMCIA cards running at a built-in power of 300 mw on each end of the link
They used two antennas with 802.11b. One was 10', the other 12'.
Yes it is fast enough to support VNC, they had a 12ms ping time.
They are going to try to break a 1Mile bluetooth record.
Oh yeah, for the guy wo said this was impossible due to the curviture of the earth: one team was on top of a mountain.
http://www.ralinktech.com/
USB wireless dongles using the RT2500 chipset aren't too hard to find, and they do have OSX and Linux (well source anyways) drivers.
http://www.ralinktech.com/supp-1.htm
(currently working on interfacing an original iMac to a Primestar dish...)
--
"I have also mastered pomposity, even if I do say so myself." -Kryten
Other than antenna legal issues, 300mW wifi cards are illegal in almost every country. Don't expect to get even similar results using the cards usually found at computer shops; you'll need high power+high sensitivity ones (read: Senao or Engenius and clones), good antennas, very short low loss cables and spending some good hours aligning the antennas.
That's an impressive result, though. Kudos to those guys.
Where d is the distance across the earth's surface, r is the radius of the earth, theta is the arc angle around the earth, and x is the height of each tower:
theta = d/r
cos(theta/2) = r/(r+x)
cos(d/2r) = r/(r+x)
r+x = r/cos(d/2r)
x = r/cos(d/2r)-r
r ~= 4000 mi., d = 300 mi., so x ~= 2.8 mi.
It's tragic. Laugh.
but what if there's even a bit of moisture in the air? The 2.4 GHz frequency of 802.11b/g is located right where microwave ovens operate, due to the absorption of the radiation by water molecules (specifically the O-H bond).
That's great for a LOS link, but what is the record for a NLOS link?
Anyone have any sites where I can find info on 600'+ NLOS links?
yesterday afternoon they said that they expect this rig would work at distances of over 300 miles." NASA's shuttles orbit at an altitude between 200K-250K miles. So Team iFibre Redwire only has another 199,700 - 247,000 miles to smash before we are all spammed from space.
Most people skipped DEFCON because of warrent issues.
"Who are in control, they are not in control of anything - they don't even control themselves!" - Glen Beck
Great! Now British wardrivers can avoid prison by using French access points.
6.51940523 × 10^-12 Parsecs
and I can't even get mine to reach my bedroom.
Havoc Video
Can we PLEASE give the evangelism a rest????
They maintained a full 11Mbit unamplified connection for 3 hours using Z-com 300mw PCMCIA cards, surplus satellite dishes, Linux, and a great deal of hacker ingenuity.
If you read TFA They did not even use the word Linux anywhere on the page!
Further, why, if they have a stable connection would the operating system on each end even matter? They could be sending recycled DECNet packets thru the antennas.
Believe it or not there there are some technologies in this world that don't involve penguins.
The Link on both ends was Linksys; the same as the 87 KM link a few years ago .....
I am the unwilling control for my Origin.
What's really amazing is that our team won this category in the same event 2 years ago with a massive 5.1 miles. We were bested 10x over by last years winner with something like 62 miles. And now this. Times they are a-changin.
List of brand/model numbers with the chipset: http://ralink.rapla.net
RALink's own GPL linux driver here.
Further development of RALink's codebase here.
Because this guy has already done it at 3kbps http://slashdot.org/comments.pl?sid=05/08/01/10132 18&threshold=1&commentsort=0&mode=nested&cid=13213 122
Unable to access the technical details link in the post, and therefore have many questions about this transmission. Please allow for my ignorance if some of these questions seem stupid. Was this transmission digital or analogue? Did you use the alloted WiFi wavelength? My understanding is the wavelength for WiFi is very very sensitive to natural and manmade conditions. Noticed your picture showed a reltively clear sky. If the transmission was done on a rainy or other inclement day would the transmission still have been possable with the wavelength you used? Do the attennas make all the difference to these questions? Needless to say after knowing more technical details, would probably have more questions. Glad amateur radio is involved in these projects. Incidentally have an extra class license myself By the way one other question. What was transmitted and what was it's mode? I mean, was it what would regularly be done on a WiFi net with a WiFi mode? Or did you use something like psk31? Again sorry if these questions may seem dumb.
You're forgetting "tropospheric ducting", which can be caused by some weather phenomena. This propagation method allows VHF signals to travel much farther than normal.
:) But they do work for "Multi megawatt FM stations"...
Ditto for "Sporadic E", which allows some lower-frequency VHF to travel due to high levels of localized ionization caused by meteors passing through the atmoshphere.
Of course, the problem is that they don't work for microwave frequencies and aren't around all the time
-JT
Looks like the old man is enjoying Astrid a little TOO much...as seen here:
http://www.usbwifi.orcon.net.nz/umbpara.jpg
Phredd - "I have found people tend to take you far less seriously once you start waving your genitals at them..."
Free market economy in the USA - you don't buy it, they don't sell it. So where's the problem?
"During this time 11,000 successful pings were made."
They were unwittingly actually connected to the McDonald's access point next door.
Now they have to do it all over again.
Richard Steven Hack - This sig is TOO GODDAMN SHORT TO DO ANYTHING USEFUL WITH! MORONS!
I'm in the unfortunate position of being 3 houses away from where the cable line stops (relatively rural area), and it is the only affordable means of high-speed internet access where I am.
I'm looking at making a deal with a neighbour 150-300m up the street to split the cost of cable internet access, and then use bog-standard 802.11b access points and cantennas to beam it down to where I am.
Problem is, there are some rather tall trees in between me and my neighbours. I can probably attach an antenna to my television aerial, which will clear some of the trees, but not all of them -- additionally I may not be able to find a cooperative neighbour with an aerial up the street, since that area has long been served with cable.
Is it feasable to get a single 150-300m in a straight line through some trees, when using cantennas?
My name is Stefan, and I was one of the contest staff this year. The Zcom cards were actually nerfed down to levels to consider them not amplified for the unamplified shot, and yes we were on top of two mountains.
Any other questions?
The cards had both been nerfed down to approximately 30mw on each end.
Unfortunately, the bluetooth link was not able to be done. They tried, but some of the hardware was not able to work with the antennas.
Both sides were on mountains. Base station on Mount Potosi at about 6225ft above sea level. Mobile unit at 4850ft above sea level near Beaver Dam.
The cards were bitbashed and nerfed to approx 30-40mw.
I'm impressed that they appear to have done this shot directly across Las Vegas. Surely the air/light/MW pollution must have been detrimental?
"For a successful technology, reality must take precedence over public relations, for nature cannot be fooled."--Feynman
I finally edited and posted the video from the DEFCON WiFI Shootout event along put some photos and topographical information up on the web.
Here they are:
http://pasadena.net/shootout05/
It was great fun watching the team set this record!