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Inspiring Adventures in SF Wireless Networking

Posted by ryuzaki0 on from the and-you-too-can-be-wirelessly-groovy dept.

JimDog writes "Here's a description I wrote of how I set up a point-to-point 802.11b link over 3.5 miles for Internet access at my house. The link runs at 3.5 Mbps, which I barely make a dent in, and I'd like to offer the rest of the bandwidth to anyone who's got line-of-sight to my location in San Francisco." The great thing about this story is both his terrific exposure to different parts of city and his willingness to share. It also makes it clear just how easy it is to set up a long distance link.

7 of 154 comments (clear)

  1. try this by sydlexic · · Score: 5, Informative

    http://www.wifinder.com/ and this http://www.80211hotspots.com/

  2. Re:Directory of WiFi by ronwolf · · Score: 2, Informative

    I can add NYCWireless to the list. Great source for those of us in the city.

  3. Re:For your safety... by dismayed · · Score: 2, Informative
    Lets make the parent more informative... :)



    Security? Seattlewireless has something to say on that... . . . tips for securing wireless networks.


    A little bit on the history of the lightning rod.


    Yeah, I know, pointless links. :)

  4. Is this legal? by Skuld-Chan · · Score: 4, Informative

    Under part 15 you're only allowed 6db of gain - this guy is running two 24db grid style parabolic dishes.

    1. Re:Is this legal? by pozar · · Score: 2, Informative
      He is allowed any gain of antenna he wants. He just has to back off on his transmitter power (1W and down) depending if his antenna has more than 6 dBi of gain and if he is running point-to-point or point-to-multipoint.

      See my paper at:
      http://www.lns.com/papers/part15
      for details on FCC Part 15.247.

  5. Re:Is this legal? (probably) by yack0 · · Score: 2, Informative

    Legal? Not sure - depends on other factors as well which aren't necessarily in the article. Chances are, he's ok, but he's never made indication of what his calculations are. Also, the FCC has been beating on people (WISPs) more for using untested (uncertified by FCC) combinations of equipment - which is easier to prove in court than overradiated power.

    6dB? Where does it say that? And where relating to a point-to-point link? The ratings are ERP (effective Radiated Power) in which the dB rating of the antenna is a single factor.

    Other things include the loss of the cable, the connectors, the power output by the device itself, etc. I suggest you get your butt over to http://www.access.gpo.gov/nara/cfr/waisidx_98/47cf r15_98.html and try reading the regulations.

    Check http://www.austinwireless.net/index.cgi/FreqentlyA skedQuestions#line83 for some more info on this, including a link to the above gpo site.

    And I think the above pertains to point to multipoint links, which have different regulations than point-to-point links on wireless.

    --
    -- There is no sig line, only Zuul.
  6. Re:802.11 risks by pozar · · Score: 2, Informative
    If you want to see what the risks are to 802.11, check out my paper at:

    http://www.lns.com/papers/part15/Regulations_Affec ting_802_11.pdf

    It covers everything from co-users (interference)to Radio Frequency Radiation to human tissue, to antenna height and equipment certification.