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Extended wireless network?

Discussion in 'Electronic Design' started by George, Jul 11, 2006.

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  1. George

    George Guest

    This may not be the right place to ask this, and if so maybe someone
    can direct me.

    A friend of mine lives out in the boondocks, and has no access to
    high-speed internet. Well, except for satellite, which he has
    looked into and would prefer not to use. But he is about 5 miles
    from another friend who does have DSL. They are both ham operators,
    so they are already endowed with large antennas.

    Is it possible to set up a private wireless network between the two
    so that they can share the DSL connection? And, a related question
    is whether it be FCC-legal with respect to spectrum usage - I assume
    to get out to five miles we would be getting into regulated spectrum
    issues.

    I read about something called WiMax, which I guess is what we really
    need for this, but that appears to be a way's off, and I just
    wondered if there were some way to get this done just between these
    two guys. Kinda like your typical home network using a wireless
    router to share a connection, except that one computer is five miles
    away.

    And I apologize if this is a silly question.
     
  2. Guest

    Not a silly question, actually a quite common one. Drop the Ham radio
    licenses out of the picture. 2.4 GHZ is right next to if not inside of
    the 2.4 ghz ham band. There are a couple of options if they have a
    line of sight RF path between them. 1. Add antennas, 2.4 ghz yagis are
    available off the shelf, as are bidirectional Rf amplifiers.Adding
    antennas is more importanat then adding transmit power, as your friends
    probably know. Do some googling on extending wireless range and a
    bunch of sites are available with ideas and tested devices. Alos
    there are some long range commerical license free units. Keep the RF
    cable to the antennas short, it is very easy to loose any antenna gain
    in the cable to the antenna at 2 ghz and up.

    The reason for dropping the ham part is, with some exceptions,
    transmitting for commericial uses over ham frequencies is not legal.
    (ie you could use the autopatch once in while to order a pizza, but not
    on a daily basis.) Also hacking a part 15 unit fof ham use may be quite
    legal, as long as only ham to ham data runs on it, but then hooking it
    to the internet is questionable.

    Steve Roberts N8VKD.
     
  3. Nico Coesel

    Nico Coesel Guest

    I've spoken to somebody who managed to get a 1Mb/s wireless connection
    in the 5GHz band wich spans about 2.5 miles with a hill covered with
    forest in between. They needed amplifiers to boost the signal to
    several Watts. If you have a line of sight, then it is much easier.
    Get a wireless router and 2 dish antennas. Look at
    http://www.smartbridges.com/
     
  4. Rich Grise

    Rich Grise Guest

    Frankly, I think it's an excellent question. But I have no idea what
    the answer is - there are wireless modems, here's one hit from a google
    search on '"long-range" wireless modem':
    http://www.ipenabled.com/aw900x.html
    they seem to have a model that'll do 50 miles, line-of-sight, with
    15 dBi antennas.

    They're a thousand bucks, though.

    But, if you can find out the freq, and license requirements, anything
    can be built, if you've got the time and money. ;-)

    Good Luck!
    Rich
     
  5. Rich Grise

    Rich Grise Guest


    Remember the "good ol' days" of ham radio, where everything above 10 GHz
    was open territory?

    Sheesh! These days, it's all allocated, at least in the US:
    http://www.ntia.doc.gov/osmhome/allochrt.pdf

    So I don't know about finding an empty spot of spectrum. Maybe on
    one of the RC channels, if you had really tight antenna patterns. ;-)

    Good Luck!
    Rich
     
  6. TheDoc

    TheDoc Guest

    http://www.hyperlinktech.com/web/antennas_2400_out_directional.php

    I've run two 24dBi dishes over 1 mile with a couple of netgear WG602v3's in
    bridge mode..
    line of sight.. but five may not be possible without amplifiers..
    your ham friends should be able to calculate the dB drop over the path
    and the required sig to noise ratio etc.......
    it's not my field.. so I cant help further, but my experiment was
    successful..
     
  7. chris

    chris Guest

    Some New Zealand guys got a fair distance using WiFi with some pretty
    cheap parts:

    http://www.usbwifi.orcon.net.nz/

    Chris.
     
  8. George

    George Guest

    I appreciate everyone's suggestions. I'll pass along the
    links.

    For my own education, could someone explain this part for
    me:

    The various wireless devices I see at BestBuy or whereever
    have at most a small single telescoping pole antenna. But
    for a long distance connection, I would think it would be
    best to have separate dish antennas, and possibly
    amplifiers, for transmit and receive. (I'm assuming
    something like a wireless router does use separate
    frequencies for xmit and rec.) Are there wireless routers
    or cards that give you the choice of using external
    antennas? I mean, like jacks on the back for that purpose?

    Sorry to ask this. I did digital and analog designs in
    another life, but not RF, which, as you all know, requires
    a magic decoder ring.
     
  9. try here
    http://www.wlan.org.uk/antenna-page.html


    martin
     
  10. Sjouke Burry

    Sjouke Burry Guest

    As long as you have line of sight, why not
    use light? That has not yet been gobbled by
    big corporations and the government.
    Using visible or IR diode transmit array or
    laser and a cheap telescope with photocell
    as detector.
    The rest of the interface is left as a project
    for the reader. ;)
    (but i could suggest the audio i/o of two modems)
     
  11. James Waldby

    James Waldby Guest

    Sjouke Burry wrote:
    ....
    There are numerous homemade installations of 10-Mbips ronja (see
    eg http://ronja.twibright.com/ and "124 Registered Installations
    of Ronja" at http://ronja.twibright.com/installations.php )
    in the 1 to 1.4 km range. For 5 mile range (~ 8 km) perhaps one
    could substitute telescopes (or binocular halves) in place of the
    simple lenses that ronja uses. Also see link to 3 km ronja
    with laser diode. (Of course, the OP hasn't said whether the
    site would allow line-of-sight connection.)
    -jiw
     
  12. The old 802.11b Orinico PC cards had a removable antenna and a mmc jack.
    I dealt with these guys, and they have an SMC with connectors, 200mw.
    http://www.fab-corp.com/product.php?productid=2364&cat=266&page=1

    Both transmit and recieve are on the same freq. The multiple antennas you
    see, are automatically switched in or out depending on the recieve strenght
    on that antenna. Most links will only use one of the antenna connectors.

    Not most long distance links are 10mpbs 802.11b.

    Cheers
     
  13. Ken Smith

    Ken Smith Guest

    There are no allocated channels below 1Hz.

    There are also no channels up above 100THz and it is fairly easy to make
    things very directional up there. If it truely is "line of sight", making
    something up there may be a fun project.
     
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