Slashdot Mirror

← Back to Stories (view on slashdot.org)

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."

15 of 321 comments (clear)

  1. 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 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)
    4. 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?

  2. 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 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!

  3. 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...

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.
  9. Will the Third World Please Step Up? by Anonymous Coward · · Score: 1, Interesting

    In my mind, the greatest implication for long distance transfer of data is going to be in the third world where standard phone and data lines just don't exist. I've read a few articles on the attempts to set up long distance wireless networks in Africa and other places by a variety of means. The end result? The end result is that information is given to people who wouldn't otherwise have access to it. I've also read that farmers in the US rely upon computer/internet data for information on things such as weather and disease, important things if you farm for a living.

    If we can offer this type of information in rural third world areas it can only improve on the quality of life. Let's think of the third world (in a very simplistic manner obviously) as the US 150 years ago. The telegraph revolutionized the US. Maybe a long distance WiFi connection in a country with no FCC worries can do the same thing.

    Maybe this experiment won't change the world, but then again, maybe it will.

  10. 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