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New WiFi Link Distance Record

Posted by ScuttleMonkey on Wed Jun 20, 2007 12:32 PM
from the wifi-vs-rfc-1149 dept.
Wireless Networking Hardware
Espectr0 writes "A Venezuelan professor along with his team have set a new record for the longest WiFi link. Using commodity hardware, they established a connection between a PC in El Águila, Venezuela, and one in Platillón Mountain, a distance of about 237 miles. The previous record was 193 miles. Slides [PDF] are also available."
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  • I've come close (Score:5, Funny)

    by nolife (233813) on Wednesday June 20 2007, @12:39PM (#19583185) Homepage Journal
    I almost get a usable signal in my bedroom which is 237 decimeters away from my access point in my basement. Oh... the article claims 237 miles. My "of the shelf" equipment must have come from the clearance shelf.
    • Well, some so-called "top shelf" stuff sucks too (think of Linksys, who uses crappy Broadcom radios in most of their equipment).

      If you use good radios (Atheros, esp. the Ubiquity 400mw cards - wow), good antennas (these guys' dishes are 27dbi? Standard routers and cards are *2*dbi) and have great/incredible LOS, the distance you can go is essentially limited only by earth curvature.

  • LOS (Score:5, Insightful)

    by Moby Cock (771358) on Wednesday June 20 2007, @12:39PM (#19583197) Homepage
    The Line of Sight caveat is a rather significant point ommitted from the summary. This is still quite an achievement.

    • Re: (Score:3, Insightful)

      by Red Flayer (890720)
      I don't understand, what caveat are you talking about?

      That this connection did have LOS? That LOS (and radio interference, etc) is obviously a problem in more populated areas, and I should expect to make this work in New Jersey?

      As far as I'm concerned, anyone who doesn't RTFA, AND somehow lacks the basic understanding of wireless communications to figure out that they must have had LOS, doesn't deserve the extra effort it takes to put in a caveat like that.

      Seriously... if someone thought that they were

    • Re:LOS (Score:5, Insightful)

      by Jeff DeMaagd (2015) on Wednesday June 20 2007, @02:09PM (#19584631) Homepage Journal
      I think the fact that a mountain was involved should be an indicator.

    • Re: (Score:3, Insightful)

      by mollymoo (202721)

      You mean they didn't have anything in the way of the signal? Damn, I was thinking when they mentioned a mountain they were going through it, not using the top of it. Not only that but the damn cheats didn't even wait till it rained!

      I've done some digging and apparently this kind of flagrant dishonesty is pretty widespread. Here are some more significant points omitted from stories elsewhere in the media:

      • Miss World was wearing her makeup.
      • The lap record at Indy wasn't set in the rain.
      • Asafa Powell didn'

  • Nice work but... (Score:5, Funny)

    by Aqua_boy17 (962670) on Wednesday June 20 2007, @12:41PM (#19583245)
    Good for them. But since WiFi is line of sight, the only way they can do this is by using mountainous regions. I guess us flatlanders will have to resort to bouncing our signals off of blimps or flying pigs (coated in foil, of course).

  • These guys are in BIG trouble with the FCC! (Score:4, Funny)

    by gc8005 (733938) on Wednesday June 20 2007, @12:49PM (#19583385)
    Just wait until the FCC hears about this! These guys are in big, big trouble.
  • I'm working with a group of people to setup an emergency wifi network grid around the county. It has hit a barrier due to technical issues mostly dealing with distance. So this can be very useful as long as they give real info rather than a "we just used a WRT54GS and a directional antennae and pumped up the wattage"

  • In unrelated news... (Score:5, Funny)

    by Anonymous Coward on Wednesday June 20 2007, @12:57PM (#19583517)
    In other news...

    Cuban government officials have begun a new, lucrative service where they have established a WiFi base and are charging $10/day to residents of southern Florida for unfettered Internet access. "We have very good download rates for Sicko and, of course, for all your favorite music artists," Castro's spokesperson is quoted as saying. In the background this reporter could hear maniacal laughter and intermittent shouts of "See what the RIAA thinks of that!" and other such obscenities.

  • They used 1 meter dishes. Of course it works. (Score:5, Insightful)

    by Animats (122034) on Wednesday June 20 2007, @01:15PM (#19583843) Homepage

    The technology is straightforward. They had line of sight, used 1 meter dishes at each end, and aligned them with telescopes. Point to point microwave links have been doing that since the 1950s. After all, you can get a signal to and from geosync orbit with a dish of that size.

    The most interesting thing about this is that they found two points on the earth's surface 273 miles apart with a clear line of sight between them.

    • Re: (Score:2, Informative)

      by lostguru (987112)
      you can get a signal to and from orbit without using a dish, but thats putting out 5W, and the same with point to point microwave links of the 1950's, a lot higher power than off the shelf wireless gear and no amp

  • 295 km in Italy (Score:3, Interesting)

    by mennucc1 (568756) <d3@tonelli.sns.it> on Thursday June 21 2007, @04:43AM (#19591961) Homepage Journal
    let me also share this record [polito.it] (announced also 24 may in in this Italian newspaper [repubblica.it]): the Ixem team [polito.it] of "Politecnico" in Torino has set up a 20megabit connection from "Capanna Margherita" (Mount Blanc, 4556m of altitude) with "Pian Cavallaro" (a point on the mountain range that divides Tuscany from Emilia-Romagna); the two points were 295km apart; the hw used was a 386 CPU running Linux; the network is Hiperlan type 2 and Wi-Max 802.16 (EIRP regulatory requirements limited to 30 dBm is satisfied). They have also set a webcam in Capanna Margherita [polito.it], that is accessed thru the link

    • Re:What the? (Score:5, Interesting)

      by drinkypoo (153816) <martin.espinoza@gmail.com> on Wednesday June 20 2007, @12:44PM (#19583273) Homepage Journal

      I am also wondering, what kind of impact does outputting a signal that strong have on living things? I don't know much about that sort of thing.

      One of my ex-housemates was a Sonar tech in the Navy. The Sonar and Radar guys apparently hang out together on those ships and one of their favorite games was to paint the guys coming up the desk with an armload of flourescent tubes with the radar, illuminating the lamps. Hilarity ensues. They never killed anyone doing it. But at close range and high power, I'm told you can throw hot dogs up into the path of the radar and they come down cooked.

      Moral of the story is that it's directional and as long as you don't stand in front of it there's not likely to be any significant effect. At the other end, the signal has been scattered substantially and it's only coming in at a whisper of the original signal.

      • In cold climes, it's been a convention to stand in front
        of microwave radar if possible to warm up.

      • Re:What the? (Score:5, Funny)

        by jonnythan (79727) on Wednesday June 20 2007, @12:59PM (#19583567) Homepage
        Joke's on you.

        Hot dogs are already cooked when you buy them ;)

        • *BSD is for People who Love *nix; Linux is for People who Hate Windows

          I just wanted to point out that I use Linux because I like Linux. I wonder if it's possible for people in general to prefer X solely for the properties of X, instead of how it is related to Y.

      • A colleague of mine was a submariner who had this story. They were down for an extended dive, and when they surfaced, they would send a short, dense burst of communications and data on a very powerful microwave uplink - get up, send fast, get back down. It was a very powerful signal - and they would surface to a depth that would get the periscope and the antenna above water, do a quick scan for surface vessels, send the burst and dive. One day they did this and saw thru the periscope there was a gull on
        • If it would just stop me from having to worry about having any children, I'd go become one today. But anyway, there are many species in which we have positively correlated temperature to gender of offspring, maybe there's a similar effect at work in us. Or maybe sperm can pick up radio waves and they get confused :)

    • Re:What the? (Score:5, Interesting)

      by aktzin (882293) on Wednesday June 20 2007, @12:54PM (#19583467)
      A friend of mine who's a military history buff told me a story about Soviet fighter aircraft in the 70s and 80s. Seems they had very powerful look-down, shoot-down radars and pilots were instructed to turn them off during take off and landing. Apparently sometimes they forgot, and runway maintenance crews had to regularly pick up the carcasses of rabbits, birds and other unlucky critters that were in the area when those MiGs went on missions.
      • That would be the MIG-25. Ridiculously overpowered interceptor radar combined with gloriously short combat radius.

      • Re: (Score:3, Informative)

        by CrossChris (806549)
        A friend of mine who's a military history buff told me a story about Soviet fighter aircraft in the 70s and 80s. Seems they had very powerful look-down, shoot-down radars and pilots were instructed to turn them off during take off and landing. Apparently sometimes they forgot, and runway maintenance crews had to regularly pick up the carcasses of rabbits, birds and other unlucky critters that were in the area when those MiGs went on missions.

        That's what we engineers would call "complete cobblers". The pow
    • That's a lot of Pringles cans and many rolls of duct tape.
      And good luck keeping it from bending.

    • Re: (Score:2, Interesting)

      by KillerCow (213458)

      Yea, one of those 75 foot off the shelf antennas.


      and a parabolic, and various amplifiers... and this:

      MAC of WiFi designed for up to 100 m, extending the range two orders of magnitude requires modifications


      They never said how they accomplished that, but it was presumably done by hacking the firmware to change the collision detection and the back-off settings.
    • Well being at 2.4ghz I'd think it would cook a turkey if you were standing next to, though I might be wrong :).
    • TFA and the presentation don't provide that much information, but it looks like they used a Linksys WRT54 (check out the photo on slide 13). IIRC, the WRT54 Tx power tops out at 100mW (the presentation also mentions 100mW on one of the "background" slides).

      Based on that, I'd say the answer to your question is "none whatsoever".

    • Re:Further the science or just a dumb stunt? (Score:4, Informative)

      by PrescriptionWarning (932687) on Wednesday June 20 2007, @12:46PM (#19583301)
      Using a directed wireless transmission is certainly far cheaper in such remote regions. Think of the equivalent cost of building and maintaining 250 miles of land line!
    • The article is from Wired. I'll let you figure it out from there.

    • Re: (Score:3, Informative)

      by Wesley Felter (138342)
      They are not making any innovation in RF, but they are testing a new experimental MAC protocol from Berkeley that provides higher throughput for long-distance point-to-point links.

    • Re:Further the science or just a dumb stunt? (Score:5, Informative)

      by jeevesbond (1066726) on Wednesday June 20 2007, @01:21PM (#19583949) Homepage

      Does this do something to actually improve RF systems (eg, testing new antennas, filters, etc etc), or is it merely a dumb stunt of only interest to guys who have a lot of empty Pringles cans around?

      Neither, if you read the PDF [eslared.org.ve] about the experiment, you'll see the aim is to discover whether stock equipment can be used to connect remote areas to the Internet. Connecting people in rural locations is a challenge being faced in many countries, others have different solutions [bbc.co.uk].

      although I suspect the left wing of Slashdot might chime in about its applicability for solving all the problems of Mugabe's Zimbabwe, etc.

      Really, I consider myself a bit of a leftie and I'd like to see Mugabe slung out of power as much as any Tory would. Comparing Mugabe to the liberal left is like comparing Karl Marx with Ronald McDonald: pointless and stupid.

    • Can we now please stop trying to set ridiculous "records" concerning WIFI connections?


      No.

      We thank you for your interest.

    • Re:Amazing (Score:5, Funny)

      by Dogtanian (588974) on Wednesday June 20 2007, @01:11PM (#19583781) Homepage

      This is amazing, yet the scientist and all the kings men STILL cannot:

      1) Keep my bluetooth headset connected to its base station an amazingly 3 feet away
      2) Keep my cellphone connected with a tower a mere 1 mile away.
      3) Put Humpty Dumpty together again.

      • Re:Amazing (Score:4, Funny)

        by emlyncorrin (818871) on Wednesday June 20 2007, @02:35PM (#19585023)

        This is amazing, yet the scientist and all the kings men STILL cannot:

        1) Keep my bluetooth headset connected to its base station an amazingly 3 feet away
        2) Keep my cellphone connected with a tower a mere 1 mile away.
        3) Put Humpty Dumpty together again.
        4) ???
        5) Profit!

    • Re: (Score:3, Insightful)

      by Lockejaw (955650)

      How is this possible?
      Directional antennas?

    • Re: (Score:2, Informative)

      by SMS_Design (879582)
      As one of the crew that ran the Wifi Shootout in Vegas a couple of years ago, I can say that there won't be another Defcon Wi-Fi Shootout any time soon. We simply ran out of Line-of-Sight locations. I'll tell you right now that the iFiber Redwire team could have established that link were they to have the LoS.

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