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High-Gain Patch Antennas Boost Wi-Fi Capacity In Crowded Lecture Halls

An anonymous reader writes "To boost its Wi-Fi capacity in packed lecture halls, Georgia Institute of Technology gave up trying to cram in more access points with conventional omni-directional antennas, and juggle power settings and channel plans. Instead, it turned to new high-gain directional antennas. They look almost exactly like the bottom half of a small pizza box, and focus the Wi-Fi signal from the ceiling-mounted access point in a precise cone-shaped pattern, covering part of the lecture hall floor. Instead of the flaky, laggy connections, about which professors had been complaining, users now consistently get up to 144Mbps (if they have 802.11n client radios). 'Overall, the system performed much better' with the new antennas, says William Lawrence, IT project manager principal with the university's academic and research technologies group. 'And there was a much more even distribution of clients across the room's access points.'"

9 of 104 comments (clear)

  1. Re:If WiFi is necessary for the lectures, by MrEricSir · · Score: 4, Insightful

    Sometimes it's useful to look something up online, test a formula, or download notes so you can understand the material better and ask informed questions.

    Regardless, it's less distracting if everyone's wifi just works (TM) than for students to be spending more time messing with their wifi configuration than listening to the lecture.

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  2. News? by Andhesaidtome · · Score: 5, Insightful

    It is hardly newsworthy that a group of IT network techs 'fixed' their coverage and performance problems using directional antenna technology. Radio techs have been doing exactly that since they learnt about propagation. A newsworthy story would be that they have (finally) started incorporating at least basic RF theory in all IT networking related courses and subjects.

    1. Re:News? by Gravis+Zero · · Score: 4, Funny

      It is hardly newsworthy that a group of IT network techs 'fixed' their coverage and performance problems using directional antenna technology.
      Radio techs have been doing exactly that since they learnt about propagation.

      so... does this mean you aren't interested in the story about how they replaced the batteries in the remote?

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  3. Radiated power? by jhol13 · · Score: 4, Informative

    In Europe we limit the maximum radiated power (EIRP). This means you'd have to drop TX power and the directional antenna helps on RX only. Still might be worthwhile.
    Although there is ample proof that WiFi don't have health issues, I still want to limit the EIRP. But to what level, I do not know. I think directional antennas currently have too strict a limit - you are not supposed to be standing next to a directional antenna anyway. OTOH people hardly understand what a 20dB antenna does (in TX).

  4. Are you serious? by Mr.+Freeman · · Score: 4, Insightful

    URGENT! URGENT! URGENT!
    DISTRIBUTION: ALL STATIONS
    MESSAGE READS:
    IT guys fix their spotty wireless coverage by installing the proper antennas.
    END URGENT MESSAGE

    Wow, thank God for that. Good thing that we have slashdot to tell us that a university installed some standard equipment on their campus. Be sure to run an article when MIT replaces a couple of their switches next month.

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  5. Re:"New" high gain antennae? by CaptQuark · · Score: 5, Insightful

    Directional antennas are not new. But configuring an array of directional antennas to precisely cover the seats in the lecture hall to minimize the number of users on any single access point is a new and novel way to deploy wireless access.

    Deploying the same number of omnidirectional antennas in the same space would lead to massive overlap, interference, and clients unnecessarily switching between APs when they perceived a stronger signal from a different AP.

    I haven't heard of a high density environment purposely set up this way therefor I think it is indeed newsworthy.

    ~~

  6. $591.25 a pop, for the antenna alone ! by Taco+Cowboy · · Score: 4, Interesting

    I read TFA, and did a search on that "bottom of pizza box" antenna.

    Found it @ http://www.terra-wave.com/shop/font-colororangenewfont-245-ghz-14-dbi-high-density-panel-antenna-with-nstyle-jack-connectors-p-2993.html

    The only problem is the price.

    The cost of the antenna alone is $591.25 a pop.

    Perhaps Georgia Institute of Technology has a big endowment, that they can afford to install such devices all over their campuses.

    For most private enterprises, on the other hand, it's simply not affordable.

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    1. Re:$591.25 a pop, for the antenna alone ! by wadeal · · Score: 5, Interesting

      (Involved in various facets of WiFi Projects for approx. 50 commercial sites).

      Any commercial grade AP is going to cost you around the $500 mark. At the least.

      Your point?

    2. Re:$591.25 a pop, for the antenna alone ! by datapharmer · · Score: 4, Informative

      Only problem is where you shop. Not to plug newegg, there are many other cheap(er) venders you can probably find this at too, but just to prove a point:

      $43 shipped: http://www.neweggbusiness.com/product/product.aspx?item=9b-33-993-021
      $66 shipped: http://www.neweggbusiness.com/product/product.aspx?item=9b-33-978-030
      $80 shipped: http://www.neweggbusiness.com/product/product.aspx?item=9b-33-993-022


      I imagine if you are buying for a large institution you have a vendor that offers volume discounts as well, so they should in theory be paying even less than this.

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