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Hello Guys,

I've a question about how to sort Wi-Fi messages using the modulation as a filter. Do you have any suggestion for that? I saw the radiotap.channel.flags.cck filter that should provide the signals modulated with CCK.... but what about other modulation schemes?

Regards

asked 02 Sep '16, 05:32

elwifi's gravatar image

elwifi
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accept rate: 0%

Is there anything specific you are looking for? I found that the information that is contained in the radiotap header is VERY hardware dependent. Some adapters give lots of good information, others not so much. Especially with 802.11n, there are many ways to send frames.

For one of my adapters that I can use on Linux, an Intel 7260, I can get this from Linux with Wireshark:

Radiotap Header v0, Length 33
    Header revision: 0
    Header pad: 0
    Header length: 33
    Present flags
    Flags: 0x10
    Channel frequency: 5745 [A 149]
    Channel flags: 0x0140, Orthogonal Frequency-Division Multiplexing (OFDM), 5 GHz spectrum
        .... .... ...0 .... = Turbo: False
        .... .... ..0. .... = Complementary Code Keying (CCK): False
        .... .... .1.. .... = Orthogonal Frequency-Division Multiplexing (OFDM): True
        .... .... 0... .... = 2 GHz spectrum: False
        .... ...1 .... .... = 5 GHz spectrum: True
        .... ..0. .... .... = Passive: False
        .... .0.. .... .... = Dynamic CCK-OFDM: False
        .... 0... .... .... = Gaussian Frequency Shift Keying (GFSK): False
        ...0 .... .... .... = GSM (900MHz): False
        ..0. .... .... .... = Static Turbo: False
        .0.. .... .... .... = Half Rate Channel (10MHz Channel Width): False
        0... .... .... .... = Quarter Rate Channel (5MHz Channel Width): False
    SSI Signal: -46 dBm
    RX flags: 0x0000
    MCS information
    [Data Rate: 72.2 Mb/s]
    SSI Signal: -47 dBm
    Antenna: 0
    SSI Signal: -46 dBm
    Antenna: 1

802.11 radio information
    PHY type: 802.11n (7)
    MCS index: 7
    Bandwidth: 20 MHz (0)
    Short GI: True
    FEC: BEC (0)
    Number of STBC streams: 0
    Data rate: 72.2 Mb/s
    Channel: 149
    Frequency: 5745 MHz
    Signal strength (dBm): -46 dBm

Any of these fields would be filterable, I believe.

(02 Sep '16, 06:04) Bob Jones
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question asked: 02 Sep '16, 05:32

question was seen: 1,411 times

last updated: 02 Sep '16, 06:05

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