802.11A Advice

Discussion in 'Wireless Networking' started by JohnO, Apr 2, 2008.

  1. JohnO

    JohnO Guest

    I'm helping our sales team find a solution to an ad-hoc networking problem
    when they demo our product (a mobile robot) at trade shows. The spectrum at
    2.4 GHz is filled at these shows, there's rarely any throughput available
    what with 30-40 nodes popping up all over.

    So, I had the braniac idea to try 802.11A instead. I picked up a pair of
    D-Link DWL-AG123 usb NICs (A/B/G), and after defeating their infernal
    software (and getting some help here in this NG) it's working much better
    than G ever did.

    I want to replicate this setup, but without that crap D-Link software. So
    far I have not found any way to use WZC to make these NICs go to A mode
    automatically. I hoped for a mode setting in their driver setup, but no
    luck. Am I missing anything else about forcing the frequency? (I use the
    laptop with the D-Link software to force A mode and set up the ad-hoc, then
    run the robot's NIC with WZC and it works.)

    If not, I need to find an 802.11A device that can be forced to A mode with
    WZC, or at least has software that makes sense. (Linksys' standard stuff
    looks great compared to the D-Link crap, and even D-Link says "use WZC".)

    Any ideas?

    I don't need security, the range is max at ~40 feet, and it needs to be USB
    modules or those little boxes.

    Thanks!

    -John O
     
    JohnO, Apr 2, 2008
    #1
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  2. You don't force it at the Nic.

    You control it by the Access Point.

    If the WAP is doing both A and G there will be two SSIDs showing when you
    scan for "available networks". You should have a different SSID for the A
    then you do the G,...then whether you use A or G depends entirely on what
    SSID you choose to connect to. Keep it simple,...do something similar to
    this:

    SSID for G = MyWLAN-G
    SSID for A = MyWLAN-A


    --
    Phillip Windell
    www.wandtv.com

    The views expressed, are my own and not those of my employer, or Microsoft,
    or anyone else associated with me, including my cats.
     
    Phillip Windell, Apr 2, 2008
    #2
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  3. JohnO

    John Guest

    I'm curious, what WAP has that option (dual SSIDs)? (IIRC) my Linksys WRT54G
    doesn't have have that capability, even when I enable dual mode, B/G. There
    can only be 1 SSID.
     
    John, Apr 2, 2008
    #3
  4. That is that case with B & G,...not A & G. Both B and G operate on the same
    band and G is backwards compatible with B so they are kind of the "same
    thing" in a way. They both operate together off of the same SSID

    The WRT54G does not do A,...you have to have a WRT55AG for that. The
    WRT55AG runs duel Radios,..one for A (5ghz) and one for B/G (2.x ghz),...so
    each Radio has its own config,...hence, two SSIDs.

    Some more expensive WAPs (not at the "home user" level) can have multiple
    SSIDs due to other completely different reasons, but we are talking about
    devices from several hundred dollars to over $1000. It is a whole different
    world after you go beyond the consumer grade "home user" stuff.

    --
    Phillip Windell
    www.wandtv.com

    The views expressed, are my own and not those of my employer, or Microsoft,
    or anyone else associated with me, including my cats.
    -----------------------------------------------------
    Understanding the ISA 2004 Access Rule Processing
    http://www.isaserver.org/articles/ISA2004_AccessRules.html

    Troubleshooting Client Authentication on Access Rules in ISA Server 2004
    http://download.microsoft.com/download/9/1/8/918ed2d3-71d0-40ed-8e6d-fd6eeb6cfa07/ts_rules.doc

    Microsoft Internet Security & Acceleration Server: Partners
    http://www.microsoft.com/isaserver/partners/default.mspx

    Microsoft ISA Server Partners: Partner Hardware Solutions
    http://www.microsoft.com/forefront/edgesecurity/partners/hardwarepartners.mspx
    -----------------------------------------------------
     
    Phillip Windell, Apr 2, 2008
    #4
  5. JohnO

    John Guest

    That makes sense. I've never had/seen/used 802.11a wireless devices. Didn't
    realize that there are 2 SSIDs in 11a WAP.
     
    John, Apr 2, 2008
    #5
  6. JohnO

    Pavel A. Guest

    Actually you can use same SSID on both A and G radios,
    but most people find this too confusing.

    --PA


     
    Pavel A., Apr 2, 2008
    #6
  7. JohnO

    JohnO Guest

    Appreciate the conversation and ideas, but the situation is ad-hoc...no WAP
    is being used. ;-)

    -John O


     
    JohnO, Apr 3, 2008
    #7
  8. JohnO

    Pavel A. Guest

    The mode for ad-hoc connection is usually in "advanced"
    parameters of a wireless driver, it is a proprietary parameter.

    --PA


     
    Pavel A., Apr 3, 2008
    #8
  9. And probably won't work in Wireless Zero Config anyway because Ad-Hoc is
    only defined by the IEEE and the WiFi Alliance to work in 802.11b and
    802.11n. Any ability to Ad-hoc using 802.11a or 802.11g is a vendor
    specific additon and thus most likely enabled by vendor specific settings
    and/or software... i.e. best to use the D-Link crapware to setup the link.

    Phil
     
    Philip Doragh, Apr 3, 2008
    #9
  10. JohnO

    JohnO Guest

    I haven't had any trouble making ad-hoc nets with WZC, so long as the IP
    addresses are static. It's very simple which is why I'd MUCH rather use it
    than the crapware. The Linksys advanced config has a "G-only mode" setting
    which works, and also gets me 54 Mbps, despite the specs that say ad-hoc is
    11 Mbps only.

    I'm finding that 802.11a isn't used much, which is a shame because there of
    the benefits there, but don't tell anyone because I want the 5 GHz band to
    myself. :) It's just tough finding hardware that works.

    -John O
     
    JohnO, Apr 3, 2008
    #10
  11. Agreed. The way the 5ghz band is being ignored makes no sense to me either.
    They probably could have made the N better by designing it around the 5 ghz
    instead of the crowded 2.x ghz

    --
    Phillip Windell
    www.wandtv.com

    The views expressed, are my own and not those of my employer, or Microsoft,
    or anyone else associated with me, including my cats.
    -----------------------------------------------------
     
    Phillip Windell, Apr 3, 2008
    #11
  12. JohnO

    JohnO Guest

    I've been joking about it here where I work, that N just makes the wireless
    noise cloud even bigger. Eventually, the 2.4 spectrum is going to be
    completely saturated in populated areas, rendering it useless. Last trade
    show I attended was for educators, (somewhat low-tech) and even there a G
    connection was barely possible and very unreliable. Try one of those
    robotics or tech shows, you can forget about WiFi.

    BTW, I found a couple devices this morning. Linksys has a nice dual-band USB
    adapter, but the manual says it won't do ad-hoc in A mode. Zyxel has one
    (AG-220) that claims you can make it into an AP. That takes ad-hoc craziness
    out of the picture, but if only that AP did DHCP, too... We'll see, I
    ordered one. The software shown in the manual doesn't look too bad.

    -John O
     
    JohnO, Apr 3, 2008
    #12
  13. Noise,...hmmm...maybe that is why it is called "N" :)

    --
    Phillip Windell
    www.wandtv.com

    The views expressed, are my own and not those of my employer, or Microsoft,
    or anyone else associated with me, including my cats.
    -----------------------------------------------------
     
    Phillip Windell, Apr 3, 2008
    #13
  14. JohnO

    JohnO Guest

    Sounds good to me.

    BTW, it looks like N actually does use 5 GHz. Apparently it uses both bands,
    but I can't find a good explanation.

    -John O
     
    JohnO, Apr 3, 2008
    #14
  15. That's the first I've heard. Maybe by using both is how it gains the extra
    speed? Back when I went through my "wireless classes" they only mentioned
    that the "Draft N" simply just existed and was being worked on, but then
    never went into any details about how it does anything. So what little I've
    learned about it has been in this group and what you can read on the
    "packaging". :)

    --
    Phillip Windell
    www.wandtv.com

    The views expressed, are my own and not those of my employer, or Microsoft,
    or anyone else associated with me, including my cats.
    -----------------------------------------------------
     
    Phillip Windell, Apr 3, 2008
    #15
  16. JohnO

    Pavel A. Guest

    yes, N mode can use either 2.4 or 5 ghz bands - coexisting with G or A
    networks.

    --PA
     
    Pavel A., Apr 3, 2008
    #16
  17. JohnO

    JohnO Guest

    Can a given adapter be forced to use 5 GHz? Maybe not all of them, but can
    some of them be forced? And can they do Ad-Hoc?

    -John O
     
    JohnO, Apr 3, 2008
    #17
  18. JohnO

    Pavel A. Guest

    As already replied - for infrastructure (AP) mode, all you need is to set
    the AP
    to either band and the laptop netcard will tune to it automatically.

    Only if you initiate ad-hoc connection, you need to specify the band thru
    that
    proprietary parameter, because there is no other way.

    Generally speaking, ad-hoc mode is much harder to implement correctly
    than infrastructure, so I suspect that many vendors just cut some corners.

    Also, there are country dependent regulations that forbid using
    some channels; the firmware of wi-fi adapters can be limited by this.

    Regards,
    --PA
     
    Pavel A., Apr 3, 2008
    #18
  19. JohnO

    JohnO Guest

    Can a given adapter be forced to use 5 GHz? Maybe not all of them, but

    Please keep in mind my situation...two battery-powered PCs connected
    together, no AP.

    Yeah, I can attest to that.
    Thanks, apparently the practical details of how this works aren't easy to
    locate.

    -John O
     
    JohnO, Apr 4, 2008
    #19
  20. JohnO

    Pavel A. Guest

    Perhaps the tech. support of your wi-fi adapter makers are just waiting your
    call.

    --PA
     
    Pavel A., Apr 4, 2008
    #20
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