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New Wi-Fi Distance Record Set In Utah

Posted by timothy on from the put-access-points-on-chairlift-poles dept.

cold_sake writes "Wireless guru Rob Flickenger details the known records for Wi-Fi link distances on his latest blog. Included is a new distance record for an un-amplified Wi-Fi link, set by the students of Utah's Weber State University. 82 miles was accomplished with 802.11b."

45 of 321 comments (clear)

  1. Hmm.. by Anonymous Coward · · Score: 5, Funny

    In other news, new cases of cancer have appeared all over the Weber State University campus.

    1. Re:Hmm.. by Stray7Xi · · Score: 3, Informative

      But it's unamplified.. it just means they had a really big antennas.

    2. Re:Hmm.. by tzanger · · Score: 5, Informative

      The Project Information page lists two 1.5W bidirectional amplifiers. But you are right, two primestar dishes with modified feedhorns, that's good for about 30dB of gain per dish/feedhorn assembly.

  2. Utah ? by Anonymous Coward · · Score: 4, Funny

    Figures the Mormons would perfect this technology ... Gotta get those RFID tags tags ready for all the Polygamists' wives

    1. Re:Utah ? by batura · · Score: 2, Interesting

      Sorry, but the guy isn't far off point.

      here is this news article

      It states between 50,000-80,000 people live in "multiple marriage" households. It also talks about a lawyer in SLC that has 30 wives and escapes legal hassle.

      here's another good one

  3. With Distances this great... by Azadre · · Score: 4, Interesting

    Will it be possible that wireless internet will become the default in the next five years over traditional phone/cable? With distances this far, would it be too hard to set it up in rural areas and provide low cost broadband?

    1. Re:With Distances this great... by Beatbyte · · Score: 4, Interesting

      Interesting? You didn't even read the article. Its directional microwave.

      Impossible to setup in rural areas. You would have to have a directional antenna for each user. Any more than 10 users and thats going to be a cluster-f$%@ of a guyed tower.

      --
      Get paid to code OSS
    2. Re:With Distances this great... by CaptBubba · · Score: 4, Interesting
      Not if my WISP is any indication of the direction wireless is headed.

      Current problems I have encountered:
      Frequent dropped connections, hourly most of the time, will come back after a min or so
      Not able to scale well. As I said a few months ago, wired networks merely slowed down when the viruses hit in Sept, the wireless network simply turned off for about a month until it was fixed
      Packetloss, very bad at times
      Then there's also the whole security issue

      That's not including the company-specific problems I have had (aformentioned month-long blackout, nonexistant after-buisness-hours support, etc). Not to mention that I don't have a real IP address, just 10.0.x.x, useless for a lot of stuff. I suppose this makes sense when you have a wildly fluctuating mass of people on your service, but it is still a pain. All this may just be one bad experience, but it has led to a distrust of the idea of 802.11a/b/g wireless deployed on a large scale

      Some of the trouble likely stems from the open frequency band 802.11b uses. I can only guess the packetloss spikes are from somebody else in the complex using the microwave or something. Of course, you can do what my WISP did and get the apartment complex/housing area to ban all private APs ($300 per day of operation fine, ouch!), but that still does nothing about 2.4GHz wireless phones, cheap microwaves, and other devices that could interfere. Not to mention: what happens if it rains? I doubt a long distance microwave link would take too kindly to a lot of moisture in the atmosphere.

      On a side note, since I will obviously be dropping this ISP in favor of DSL or cable as soon as my contract comes up, am I pretty much SOL in terms of their wireless AP ban? I mean, running multiple drops of cat-5e to every room is doable, but I'd like to avoid it if possible. I get the feeling that this is a grey area where they can pretty much say whatever they want.

    3. Re:With Distances this great... by tonyr60 · · Score: 2, Informative

      I would not get too optimistic about the opportunties that this accomplishment appears to offer rural communities. I am not familiar with the area, but it looks like most of the link is over water and I am sure that it is line of sight. I suspect any sort of obstruction, rain, maybe fog, dust etc. would stuff it up. In addition any sort of interference from portable phones, microwaves etc. etc. would also affect it.

      Reliable rural connection would need more than 802.11b power for anything close to that range.

    4. Re:With Distances this great... by DarkSarin · · Score: 3, Interesting

      I don't know as much as I should, but since my brother is in the business, I feel I need to comment. Most of your Microwave links are fairly hardened against weather. Yeah, it cuts down range, but you would build two towers at the extreme end of the range.

      The upshot of this is that you might consider towers every 40 mi, which is still respectable, but then it leaves you with the rather serious problem of how to connect this to the people on the ground. It sounds to me like a way to shoot data across a large distance, and then distribute. The sad part about this is that they are using 802.11b. The slow speeds make it less than ideal for large numbers of users.

      Instead, why not use one of the more powerful antennas available from Proxim (the Tsunami does like 430 Mbps (full duplex) at 5 miles), and if you need greater range, there are antennas that can handle that (although they are slower)), or a similar company. Many of their antennas are license exempt, but still operate outside th 2.4GHz band (5.8GHz, typically). The only one that is licensed operates at 23 GHz (wow!).

      At one point I was looking into starting a WISP, but decided that the rollout was a little too high initially. Instead I went back to school.

      --
      "We don't know what we are doing, but we are doing it very carefully,..." Wherry, R.J. Personnel Psychology (1995)
    5. Re:With Distances this great... by timeOday · · Score: 2, Interesting

      What's the problem with having an antenna for each user, as opposed to a mile or two of cabling or fiber?

    6. Re:With Distances this great... by drinkypoo · · Score: 4, Insightful
      You need a wireless interface for each user, but you can bring in multiple connections on one piece of fiber. You also need a bigass antenna for each user for whom you are trying to get significant range. Other than that, nothing.

      However you are better off with a series of stations, maybe mesh-networked, maybe not, with both directional and omnidirectional antennas. The directionals will point either at home base or other stations, and the omnis will handle serving individual users.

      Then, the users can have directionals pointed at the omnis. Perhaps you'll only be able to get a five mile range (on average) with a primestar dish on one end and an omni on the other, but you'll be able to get a lot of users connected to one station that way.

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
  4. Internet? In Utah? by Anonymous Coward · · Score: 3, Funny
    Wireless guru Rob Flickenger details the known records for Wi-Fi link distances on his latest blog.
    In other news, it was determined that Rob Flickenger's blog is the only internet content generated in Utah (unless you count the "Tech Support Hell" stories from all the call centers in Ogden).

    --
    Rate Naked People at FuckMeter (Not work-safe [unless your boss likes porn])
  5. Why does my wireless account at Weber suck? by MikeDawg · · Score: 5, Interesting

    Seems amazing especially because of the close by mountain range.

    Now can someone explain to me why I have such difficulty connecting to their wireless network while I'm on campus?

    --

    YOU'RE WINNER !
    Another lame blog

    1. Re:Why does my wireless account at Weber suck? by iamplupp · · Score: 5, Funny

      easy. you need the wifi speed spray!>

    2. Re:Why does my wireless account at Weber suck? by helix400 · · Score: 2, Interesting

      Heh, in the Weber State computer science building, you can't even get a wireless connection if you're not on the same floor as the hub. And the building is only two freaking floors, and only has about 10 classrooms!

  6. Inside sources... by TrevorB · · Score: 5, Funny

    A new distance record for an un-amplified Wi-Fi link, set by the students of Utah's Weber State University. 82 miles was accomplished with 802.11b.

    Sources within Utah's Weber State University state that this amazing feat was accomplished with the aid of an 82 mile long antenna, laid horizontally along the ground toward the Wi-Fi node.

    (Yes, dammit, I didn't read the article...)

  7. yeah. here's how they did it. by interstellar_donkey · · Score: 5, Funny

    They set up one wireless access point with the SSID set to the default 'Linksys'.

    And many, many miles away they turned on their windows machine, and voila! There it was, the WAP with the SSID 'Linksys', wide open just as they had left it!

    --
    The Internet is generally stupid
  8. huh? by mOoZik · · Score: 2, Insightful

    The link says 72 miles. The slashdot posting says 82. 10 miles is a pretty large error.

    --
    A blog like any other.
    1. Re:huh? by frazzydee · · Score: 3, Insightful

      check the blog- it says that the site originally said 72 miles, but now it says 82. Hope this clears things up. Maybe there was a mistake on the original .edu website which they corrected later?

    2. Re:huh? by dwillden · · Score: 2, Informative
      Well being a CS student at Weber, I had no knowledge of this except for the local newspaper.

      However the discrepancy in the distances is due to the time frame. The newspaper The Standard Examiner www.standard.net reported that they reached the 72 mile distance last week. And that they would attempt a longer distance over the weekend. They were going to try for 90 miles but I guess they settled for 82.

      --
      I'm too lazy to compose a creative sig.
  9. Scary by BassAkwards · · Score: 2, Funny

    Jeez, with that kind of range wardrivers no longer need to back the Chevy Tahoe out of the garage.

  10. What was the SSID? by Phrogz · · Score: 4, Funny

    Just out of curiosity, they didn't happen to link to an SSID named 'linksys', and think it was the right network, did they? :)

  11. I wonder what they tweaked by PureFiction · · Score: 5, Interesting

    The 802.11b MAC layer is fairly sensitive to timing latency. (I go into more detail on this article on timing in long 802.11 links)

    Did they use the old ad-hoc demo peer to peer mode, which has no ACK's and performs much better over longer links?

    Cisco cards are also well known for their quality; perhaps the cisco MAC can adapt to high latency long shots while also working well in infrastructure mode.

    Does anyone have more details on exactly how tenuous this link was, and how they pulled it (card settings, cables, antennas?)

    As a side note, myself and some others have been wondering how we might go about discerning the exact timing characteristics of different 802.11 MAC implementations using non-exotic hardware (like regular cards in monitor mode).

    When you need to measure microseconds (or fractions of them) it gets tricky...

    1. Re:I wonder what they tweaked by mindstrm · · Score: 2, Insightful

      how do you determine it was illegally amplified?

      Respectfully.. did you (or they) do the math and show that it violated FCC regulations, or are you just assuming that because there is an amplifier, it's illegal (which would be wrong)

    2. Re:I wonder what they tweaked by PureFiction · · Score: 2, Informative

      Arg, I hate doing the EIRP limit math! *grin*

      Here is the FCC law (which no one cares about, but I brought it up)

      1. The limint for directional links is 4W EIRP at 6dBi. That means 1W dBm output (from radio), plus antenna gain. The 6dBi bit is important. The higher gain your antenna, the more you have to reduce output power.

      2. For every 3dBi over 6dBi in antenna gain, you need to reduce output power by 1dBm. This means that your effective signal output is higher, while the transmit power from the radio is lower than 1W.

      So, here is a handy table of legal radio + antenna pairs starting with the most powerful radio combination first:

      1.0 W radio + 6dBi antenna == 4W EIRP
      500 mW radio + 9dBi antenna == 4W EIRP
      250 mW radio + 12dBi antenna == 4W EIRP
      125 mW radio + 15dBi antenna == 4W EIRP
      62 mW radio + 18dBi antenna == 4W EIRP
      31 mW radio + 21dBi antenna == 4W EIRP

    3. Re:I wonder what they tweaked by PureFiction · · Score: 3, Informative

      I need to quit posting sans-caffeine. The above are for multipoint. For directional the table is as follows:

      1.0 W radio + 6dBi antenna == 4W EIRP
      500 mW radio + 15dBi antenna == 16W EIRP
      250 mW radio + 24dBi antenna == 63W EIRP

  12. Once you pop, you can't stop... by rohan_leader · · Score: 4, Funny

    That must be one hell of a pringle can..

  13. Fine tradition of microwave hacking by isdnip · · Score: 5, Informative

    Weber State is famous for having launched its own satellite, Webersat, one of the OSCAR series. These kids are really at home with UHF and microwave radios!

    In practical terms, the range of a microwave link, such as 2.4 GHz, is based on having line of sight without attenuation. The radio line of sight path is based on the horizon, with a simple guideline of roughly horizon (miles) = 1.4 * sqrt(height-in-feet). So if you have totally flat ground and 100-foot towers, your range to the horizon is 14 miles. The range of a hop is the sum of both sides' horizons. Now if you have a 2500-foot-high mountain to stand on, then your horizon is stretched to 70 miles.

    The path loss is a function of distance, which antenna gain can make up for. The legality of doing this with unlicensed WiFi is a different question. Ham radio operators do this stuff routinely, but ham power limits are much higher, and there's no ERP limit. The 10 GHz band in particular is said to be popular in England. The crowded 144 and 430 MHz bands respond to similar rules. Attenuation by moisture in the air (serious form: rain fade) can get in the way, though. So if you're really looking for good distance, a nice place might be, oh, the Utah desert. Flat and no humidity.

    So while it's possible to hack a good range with enough effort, conventional WiFi equipment is still not reliable getting from one side of my house to the other. It's really not a threat to the phone companies, especially in non-rural areas.

    1. Re:Fine tradition of microwave hacking by PureFiction · · Score: 4, Informative

      So while it's possible to hack a good range with enough effort, conventional WiFi equipment is still not reliable getting from one side of my house to the other.

      I hear this complaint often. The problem is that AP's use weak radio's, especially the cheap ones. Sometimes as low as 30mw.

      Client cards use low power, almost always 30mw.

      You want good signal? Use two 200mw senao/engenius/teletronics cards (boy, these companies change hands quickly...)

      They sell them for $100 at teletronics.com and you can still find the old senao/engenius models on ebay and elsewhere for less.

      200mw on both ends of a link lets you cut through the walls in your house, through the neighbors house, and out into the street :-)

  14. Lessons Learned by numbski · · Score: 4, Informative
    Lessons Learned

    1. Unsure of FCC regulations. Experiment could not be put into commercial application

    The part15 rules would allow this so far as amplification goes. The part that would get you into trouble in a commercial application is the fact that your antenna, radio, and amp are not FCC certified as a system. You can't take a certfied amp, a certified radio, and a certified antenna, throw them together and call it a 'system'. You have to certify each combination individually, which costs roughly $10k. That being said, if you were were going to sell more than 10 of them, it would be worth the money.

    2. Better inventory of equipment.

    Spectrum analysis would probably be good too. Search for the least impeded part of the spectrum using peak hold, and use that area. Probably could have gotten better throughput that way. Just plug your antenna into the SA and viola!

    3. Better P.R. and release of information to the public.

    Local newspapers have been latching onto wireless broadband around here...especially ConvergeNow, which claimed a launch a year ago...one of the biggest wireless broadband scams EVER. And I had the misfortune of being a tech in a legally binding contract with them to help deploy. Screwed individuals out of thousands on their credit cards.

    4. Smaller teams with designated responsibility and tasks. Groups were to large for interactions

    Makes sense. ;)

    5. Defined budget - working within a budget

    That being said...someone want to lend me about $50k to finish up deployment in St. Louis? We're not on 2.4Ghz, and it's good tech! :)

    --

    Karma: Chameleon (mostly due to the fact that you come and go).

  15. watson_come_here.mp3 by Anonymous Coward · · Score: 4, Funny

    From the article (yes, the article):
    After verifying signal strength and quality the group in Bluffdale prepared an MP3 file for file transfer.

    So this was really just a way to evade file-sharing restrictions on the campus network?

  16. Utah record not valid by RealProgrammer · · Score: 5, Funny

    Actually I've been following these experiments.

    They bounced the signal off Darl McBride's head, and the resulting distortion caused a rip in the fabric of space-time. That's why some reports have 72 miles and others 83. There was some heavy magnetomoronic craniorectal inversion in the signal.

    This is similar to wind-aided records in track and field, and so the methods will have to be retested after Darl returns to his home planet.

    --
    sigs, as if you care.
  17. BFD by avgrunt357 · · Score: 4, Interesting

    Big F'n Deal.

    If you look at the map, they punched the signal over water.

    No wonder these eTards were able to get the distance out of it.

    Try it over land and get back to me.

  18. Looks like it was amplified by rednaxela · · Score: 5, Informative

    Equipment List:

    2- Primestar Satellite Dishes with modified feedhorns
    2- Laptop computers with 350 Cisco wireless cards
    2- Bidirectional Amplifiers (1.5 watt)
    Compass & GPS
    Tripods
    Cables and wires - MMCX RT ANG male to N Male on RG174, 72".
    http://classes.weber.edu/wireless/Project%20 Inform ation.htm

    They also stated they weren't sure of FCC regulations in the Lessons Learned page.
    http://classes.weber.edu/wireless/Lesson%20 Learned .htm

    FCC Regs state that the maximum power level for unlicensed devices in the 2.4 GHz range are:
    Field Strength of Fundamental (millivolts/meter) - 50
    Field strength of fundamental frequency harmonics (microvolts/meter) - 500

    See http://www.hallikainen.com/FccRules/2002/15/249/

    In other words, it's cool, but it's illegal.

  19. soudsn about right by Brigadier · · Score: 2, Funny



    after driving through utah I woudl say it's abotu the onl place desolate enough and rid of any disturbance be it microwave or otherwise. My cell phone was dead for about 2/3 of the drive. I think it's teh I80 or I70 or I76 no exits no trees no cars nothing just rocks.

    1. Re:soudsn about right by ZackSchil · · Score: 2, Funny

      Are you driving through there right now? Your post seems to be breaking up. :)

  20. Un-amplified? by erp6502 · · Score: 2, Interesting

    Hmm... According to their project info page, they used two 1.5W bidirectional amplifiers. Probably not legitimate under part 15.

  21. NOT A RECORD AT ALL!!! by Anonymous Coward · · Score: 5, Interesting

    If you read the actual blog entry, Rob refers to the actual record of 310 km (192 miles) by a Swedish team.

    Man, I know this is slashdot and no one reads the articles, but you thing the editors would once in a while.

  22. 1.5W is one heck of an "un-amplified" amplifier by Burdell · · Score: 2, Insightful

    If you read the actual pages, they used 1.5W amplifiers. Their "lessons learned" page says "Unsure of FCC regulations"; more like FCC regulations ignored. FCC regulations for unlicensed use of the 2.4GHz spectrum for communications limit you to 1W ERP; with 1.5W amps and high gain antennas, they were well beyond the FCC regulations. Give me a big enough amp and a good antenna and I can transmit 2.4GHz a lot longer distance, at least until the feds track me down.

  23. Actually by anethema · · Score: 2, Interesting

    It seems it was amplified. I dont see unamplified on their site, and in the project materials it lists bidirectional signal amplifiers (1.5 watt).

    Not to say this isnt still amazing. I'm setting up some long distance point to point WiFi myself, albiet with a bigger dish on one side for testing. Not 82 miles, but im doing it for practical reasons.

    Primestar dishes seem to have a gain of around 20dB at 2.4ghz if you have a decent feedhorn. (20dB is a gain of around 100). I'll be using at least one old c-band dish. It should have a gain of 30dB or more. (thats a gain of around 1000)

    My eventual plan is to set up a site on a mountain with a fairly high gain omnidirectional antenna, and then anyone who wants to connect to the LAN just points at it with a primestar dish. If i can find sponsors I will even make it 802.11G and connect it to the internet.

    This way anyone can have wifi access, at least from home, and I wont need to blanket the town in access points, interfere with cordless phones/other networks, etc because without the high gain of the primestar dish you shouldnt even be able to see the network. Should be fun.

    --


    It's easier to fight for one's principles than to live up to them.
    1. Re:Actually by aXis100 · · Score: 2, Informative

      We had this problem on the WaFreenet, so we set about creating some software to fix it.

      The result was frottle. It's a bit of a kludge, but essentially provides a virtual token bus over ethernet. It runs at the wrong layer (UDP), but is suprisingly effective. Before, with 14 clients to the HillsHub AP (many clients in the 10's of kilometers), we'd get crippled throughput rates below 10kB/sec. Now multiple users can sustain data rates above 80kB/sec (or better depending upon load).

  24. Re:Rural areas... by The+Clockwork+Troll · · Score: 2, Funny

    Gentlemen, you'll both recall I made fun of each of your respective "observations" in aforementioned article threads prior to either of your discovering the other and certainly before this latest silly debate.

    --

    There are no karma whores, only moderation johns
  25. So they finally got a signal... by Aadain2001 · · Score: 2, Funny

    ..from earth to the planet that Darl McBride is living in. It'll be a loooooooong time before any one is able to get a distance greater than that ;)

    --
    Space for rent, inquire within
  26. Wireless is best for rewiring anyway... by Kjella · · Score: 2, Interesting

    Every new student housing I know (and a lot of old ones retrofitted) *and* the two latest building projects I looked at directed at young people had added cables to the housing. Why? Because the cost isn't really that high when added at build time. Pulling cables everywhere afterwards would be expensive.

    Same with new housing areas. They drop the cables in the ground now, whether they use them or not. Compared to digging up the entire area again, it's cheap. Ok this long-distance wireless is cool, but for anything like relatively densely populated areas, I think wired is the future.

    The great thing about wireless is when the wires are actually in the way... like e.g. to your laptop or something else you'd actually move around. If not, I'd rather have a 100Mbit switch (as I do now) and a 1Gbit switch in the future :) Though the next one will probably be a combo with wireless for my laptop...

    The only other good use I've seen for wireless, which would be a "everywhere" access like my cellphone, is currently insanely priced. Right now I wouldn't consider it for anything, and even in the future I don't see it as my primary internet connection. Again, maybe workplaces, universities and other places where you have a laptop you carry around. But in general? No. Not until the prices come waaaay down.

    Kjella

    --
    Live today, because you never know what tomorrow brings