Re: [Discuss-gnuradio] Transmitting 802.11 packets with the HackRF w/out burst transmissions

[Bastian Bloessl]

Hi,

you're right that there is no burst mode like with the UHD blocks. But
that doesn't mean that it won't work.

With UHD (in tagged stream mode) you first load all samples of a burst
in the input buffer and then stream to the device. That makes
interruptions due to scheduling (and therefore frame corruption) less
likely.

With the HackRF, you just stream samples to the device and it will send
them out without any explicit indicators where the burst starts and
ends. If you stream samples fast enough without interruptions during a
frame, it should work.

Did you try the 3.8 version of the module? If there are problems, you
can share the flowgraph and I'll give it a try.

Best,
Bastian



On 11/6/19 7:55 AM, Eamon Heaney wrote:
> Thanks for the tip, looks like I've got some work ahead of me.
> Appreciate it.
> 
> On Wed, Nov 6, 2019 at 1:28 AM Alexander W <address@hidden
> <mailto:address@hidden>> wrote:
> 
>     Hey, 
>     I was running into the same problem by running the 802.15.4
>     flowcharts with a Pluto SDR. To enable burst transmission I wrote a
>     block that pads zeros to the end of a tagged stream to fill the
>     buffer of the SDR. 
> 
>     The block is added to bastibl's gr-foo OOT module. The Block is
>     called "pad tagged stream". To use it you need to set the buffer
>     size to the buffer size of the HackRF. 
> 
>     Regards, 
>     Alex
> 
> 
> 
>     Eamon Heaney <address@hidden <mailto:address@hidden>> schrieb am
>     Mi., 6. Nov. 2019, 07:10:
> 
>         Hi,
> 
>         Been working on this Gnuradio/HackRF wifi transmitter for a
>         while now, and recently learned that the HackRF driver doesn't
>         support burst transmission. I've been working off the wifi_tx
>         example
>         
> <https://github.com/bastibl/gr-ieee802-11/blob/maint-3.8/examples/wifi_tx.grc>
>         from bastibl's gr-ieee802-11 repo so far, but it looks like I'll
>         need another approach.
> 
>         Is there another method that could transmit 802.11 packets that
>         would work with the HackRF?
> 
>         Thanks!
> 
> 
> 
>         -- 
>         Eamon Heaney
>         /
>         /Fleet Commander/
>         //
>         /President, Model UN at Virginia Tech
>         /
>         /
> 
> 
> 
> -- 
> Eamon Heaney
> /
> /Fleet Commander/
> //
> /President, Model UN at Virginia Tech/
> /

-- 
Dr. Bastian Bloessl
Secure Mobile Networking Lab (SEEMOO)
TU Darmstadt, Germany

www.bastibl.net
GitHub/Twitter: @bastibl