transmission errors in long frames and unstable operation
pgawlowicz opened this issue · comments
Hello Seemoo Lab team,
First of all, thank you for your great work! I have managed to use it successfully. However, I have a few questions regarding the whole system running on Rpi3+.
-
Is sending a waveform through Nexmon SDR subject to CCA? I was not able to find this information, can we somehow enforce it?
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I have generated a valid waveform for 802.11 data frame with a duration of 1ms (around 2kB of payload, MCS 1) and 48k Nexmon samples. When I send the waveform using USRP the COST WiFi chip is able to receive it perfectly. However, when I send it over Rpi3+ using Nexmon SDR the frame always has some errors in the payload in the middle of it (i.e. I use a simple repeated string as payload and it using
tcpdump
as ASCII). -
For the shorter frames, e.g. 0.5ms (payload of 1kB and MCS 1), there are no errors and the frames can be received successfully. However, only one out of a few frames is received. I send
NEX_SDR_START_TRANSMISSION
command every 2 seconds to the Broadcom chip and I operate on clear WiFi channel in the 5Ghz band. Is the waveform always sent when issuing the command? Have you already experienced a similar behavior? The entire setup is great, and I want to use it for my prototype, however, I need to make it more robust and deterministic.
Thank you for your answers and help!
Best Regards,
Piotr