Re: [Discuss-gnuradio] Problem with BBN's 802.11 MAC

[Dan Halperin]

Are you trying to capture real 802.11 1Mbps packets, or what?

To do that you'll need to do:

$ ./bbn_80211b_rx.py -f 2.462G -d 8 -b
>>> gr_fir_ccf: using SSE
Packet received, length = 148, rssi = -15, rate = 1.0 Mbps
Packet received, length = 147, rssi = -40, rate = 1.0 Mbps
Packet received, length = 148, rssi = -16, rate = 1.0 Mbps

The -d 8 is so it gets enough of the spectrum, the -b is so it uses the
Barker spreading from the 802.11 spec.

However, I wouldn't expect to receive much more than beacons, probe
requests and responses, and CTS-to-self for 802.11g protection mode. At
least that's what I see in our wifi network.

-Dan

Dola Saha wrote:
> When I run
> ./bbn_80211b_rx.py -v
>
> I get the following output:
>
> -------------------------------------------------
> Bits Per Encoded Sample = 8
> adc frequency =  64000000
> decimation frequency =  16
> input_rate =  4000000
> gain =  45.0
> desired freq =  2400000000.0
> baseband frequency 2396000000.0
> dxc frequency -4000000.0
> Samples per data bit =  8
>>>> gr_fir_ccf: using SSE
> -------------------------------------------------
>
> No packet is captured.
>
> However, when I use ./bbn_80211b_tx.py to transmit packets, I can
> capture those packets and the output of ./bbn_80211b_rx.py -v is as
> follows (with ./bbn_80211b_tx.py run in another terminal)
>
> --------------------------------------------------------------------
> Bits Per Encoded Sample = 8
> adc frequency =  64000000
> decimation frequency =  16
> input_rate =  4000000
> gain =  45.0
> desired freq =  2400000000.0
> baseband frequency 2396000000.0
> dxc frequency -4000000.0
> Samples per data bit =  8
>>>> gr_fir_ccf: using SSE
> uOPKT: 1, len=1477, rssi=-19, src=20:61:6e:64:20:73, time=6981528,
> rate=1 Mbps
> PKT: 2, len=1477, rssi=-19, src=20:61:6e:64:20:73, time=6993624,
> rate=1 Mbps
> uOuOuOPKT: 3, len=1477, rssi=-19, src=20:61:6e:64:20:73, time=8045696,
> rate=1 Mbps
> PKT: 4, len=1477, rssi=-19, src=20:61:6e:64:20:73, time=8057792,
> rate=1 Mbps
> PKT: 5, len=1477, rssi=-19, src=20:61:6e:64:20:73, time=8069888,
> rate=1 Mbps
> PKT: 6, len=1477, rssi=-19, src=20:61:6e:64:20:73, time=8139992,
> rate=1 Mbps
> PKT: 7, len=1477, rssi=-19, src=20:61:6e:64:20:73, time=8164184,
> rate=1 Mbps
> PKT: 8, len=1477, rssi=-19, src=20:61:6e:64:20:73, time=8188376,
> rate=1 Mbps
> PKT: 9, len=1477, rssi=-19, src=20:61:6e:64:20:73, time=8212568,
> rate=1 Mbps
> PKT: 10, len=1477, rssi=-19, src=20:61:6e:64:20:73, time=8236760,
> rate=1 Mbps
> PKT: 11, len=1477, rssi=-19, src=20:61:6e:64:20:73, time=8335648,
> rate=1 Mbps
> PKT: 12, len=1477, rssi=-19, src=20:61:6e:64:20:73, time=8347744,
> rate=1 Mbps
> -------------------------------------------------------------------------------------------------
>
>
> The packet counts are not from original code, I printed them.
>
>
>
>
> Thanks,
> Dola
>
>
>
>
> On 4/4/07, Greg Troxel <address@hidden> wrote:
>> Could you explain more precisely what you are doing, and what happens?
>>
>> I have run the code under NetBSD with modified tap(4) driver that
>> handles 802.11 in addition to Ethernet.  I am not clear on the state of
>> 802.11 support in the Linux tap driver.
>>
>> -- 
>>     Greg Troxel <address@hidden>
>>
>
>
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