Is it B or G I'm receiving?

Archived from groups: alt.internet.wireless (More info?)

Does anyone have any idea how to discern whether or not a received
signal is "802.11B" or "802.11G"? I mean short of having both
adaptors.

Does a "G" signal show up on a "B" survey?

As the frequencies are the same it seems to me that you could see
signal but not be able to connect. Is this a correct assumption?

TIA

Gord
5 answers Last reply
More about receiving
  1. Archived from groups: alt.internet.wireless (More info?)

    I doubt if a "b" survey list would show a "g" signal (but a "g" survey will
    show a "b" signal). The presence of a "g" signal might cause the channel to
    appear busy, but the energy would not be decoded as a signal.

    "Gord Ipsofacto" <ipsofacto@operamail.com> wrote in message
    news:2ma2b01pcrfosqoitg298sceula5kslmju@4ax.com...
    >
    >
    > Does anyone have any idea how to discern whether or not a received
    > signal is "802.11B" or "802.11G"? I mean short of having both
    > adaptors.
    >
    > Does a "G" signal show up on a "B" survey?
    >
    > As the frequencies are the same it seems to me that you could see
    > signal but not be able to connect. Is this a correct assumption?
    >
    > TIA
    >
    > Gord
  2. Archived from groups: alt.internet.wireless (More info?)

    > I doubt if a "b" survey list would show a "g" signal (but a "g" survey
    will
    > show a "b" signal). The presence of a "g" signal might cause the channel
    to
    > appear busy, but the energy would not be decoded as a signal.

    Hmm
    I have a 801.11b card in my palmtop and I use ministumbler and WiFiFoFum
    to scan for wireless networks - the card itself can only do 11Mbs but
    ministumbler states higher AP speeds like 22, 44, 56Mbs along with
    information about AP manufacturer etc. I believe that all 801.11 standards
    are backwards compatible and that the connection is actually established
    at the highest possible speed made possible by both devices (of course
    except for 801.11a which is 5GHz as oposed to 2,4GHz )

    T.P.
  3. Archived from groups: alt.internet.wireless (More info?)

    >
    >
    >Does anyone have any idea how to discern whether or not a received
    >signal is "802.11B" or "802.11G"? I mean short of having both
    >adaptors.
    >
    >Does a "G" signal show up on a "B" survey?

    Yes.
    >
    >As the frequencies are the same it seems to me that you could see
    >signal but not be able to connect. Is this a correct assumption?

    No, .11G is backwards compatible with .11B. Or .11G would be dead in
    the water (like .11 A).

    >TIA
    >
    >Gord

    B and G are completely compatible. If your throughput is over 5 or 6MB
    (and you have a .11G card) you can count on it being .11G.
    ------------
    When your PC gives a little they give a lot.
    http://www.dslreports.com/forum/disco
  4. Archived from groups: alt.internet.wireless (More info?)

    802.11g is back-compatible with 802.11b, but not the other way around. A
    frame sent at any datarate other than 1, 2. 5.5, or 11 Mbps is
    undecipherable to an 802.11b-only adapter, by definition.

    802.11g access points may transmit beacons at datarates (and therefore using
    encodings) that are defined in the 802.11b standard. These beacons include
    information elements that define the supported datarates and encoding
    types.The AP manufacturer can be deduced from the first three bytes of the
    source MAC address in the beacon frame.

    So, if an 802.11g AP is broadcasting beacons at 1 Mbps, an 802.11b client
    can receive them. If a "real" 802.11b client driver is running the adapter,
    then its site survey will probably not show an 802.11g network, because it
    will not be able to interpret the datarate parameters specifying rates over
    11 Mbps (that is, "g" is not a concept designed into "b" drivers). If
    Airsnort or Netstumbler runs the adapter in promiscuous mode, then these
    tools know how to interpret "b" and "g" information elements, and so can
    tell if the AP supports "g".

    Many vendors support a "g"-only option in configuring the AP. As far I can
    tell, the standard does not require the beacon to be transmitted at any
    particular rate. If the AP is configured to support hybrid nets, it's
    reasonable to assume that the beacon goes out at a rate supported by all
    clients - i.e., 1 or 2 Mbps. If "g"-only is configured, it seems to me that
    the AP is permitted to use a non-"b" rate.

    "Yankes [Wroc]" <USUNyankesTO@eranet.pl> wrote in message
    news:c8scpj$ltr$1@achot.icm.edu.pl...
    > > I doubt if a "b" survey list would show a "g" signal (but a "g" survey
    > will
    > > show a "b" signal). The presence of a "g" signal might cause the channel
    > to
    > > appear busy, but the energy would not be decoded as a signal.
    >
    > Hmm
    > I have a 801.11b card in my palmtop and I use ministumbler and WiFiFoFum
    > to scan for wireless networks - the card itself can only do 11Mbs but
    > ministumbler states higher AP speeds like 22, 44, 56Mbs along with
    > information about AP manufacturer etc. I believe that all 801.11 standards
    > are backwards compatible and that the connection is actually established
    > at the highest possible speed made possible by both devices (of course
    > except for 801.11a which is 5GHz as oposed to 2,4GHz )
    >
    > T.P.
    >
    >
  5. Archived from groups: alt.internet.wireless (More info?)

    In rereading the original post, I see I answered the question(s) too
    narrowly.

    802.11g supports 802.11b. An 802.11g AP can talk at "g"-only datarates to
    802.11g clients, and at "b" datarates to 802.11b clients. That's a hybrid
    network.

    Your "b" adapter cannot decipher "g"-only transmissions, or even recognize
    them as signals. It *can* connect to an 802.11g AP that is configured to
    support hybrid networks. Its conversations with the AP will use 802.11b-only
    datarates and encodings. If the AP supports hybrid networks, it probably
    sends its beacon frames at an 802.11b datarate, so it will appear to be an
    802.11b network to an 802.11b client.

    "Gord Ipsofacto" <ipsofacto@operamail.com> wrote in message
    news:2ma2b01pcrfosqoitg298sceula5kslmju@4ax.com...
    >
    >
    > Does anyone have any idea how to discern whether or not a received
    > signal is "802.11B" or "802.11G"? I mean short of having both
    > adaptors.
    >
    > Does a "G" signal show up on a "B" survey?
    >
    > As the frequencies are the same it seems to me that you could see
    > signal but not be able to connect. Is this a correct assumption?
    >
    > TIA
    >
    > Gord
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