802.11 error frame reception

[humptydumpty]

For a commercial application we need 802.11 error frame reception in promiscuous mode. Purpose is to implement Reed-Solomon-Code for error correction of broadcast packets. Is it possible?

[ESP_Angus]

Do I understand correctly that you want to be able to receive invalid 802.11 data frames?

I don't think this is possible on ESP32, the lower MAC layer discards them at an early stage (it more or less has to, in order to maintain good throughput of valid frames.)

Maybe I don't understand your full purpose, but as you probably know 802.11 already makes use of forward error correction algorithms.

[humptydumpty]

I understand that 802.11 already has forward error correction. However, when the error correction fails for one or more blocks within a packet, the entire packet is discarded.

Due to the highly repetitive nature of the data we are sending, it would be useful to receive the discarded packets. The remaining blocks could be used. This would considerably extend the usable range of the device.

We could also just send a lot of short packets of course. But the overhead would be quite large. And the ESP32 seems to be limited to about 1.2 milliseconds per packet. So we couldn't get such a big improvement this way without sacrificing necessary throughput.

[ESP_Angus]

I see, thanks for explaining. I've asked the Wi-Fi team if it's possible to forward frames with bad FEC to the sniffer (promiscuous) interface.

We won't get an answer until next week, due to the Spring Festival holiday.

[ESP_Angus]

It seems like this may be possible in a future release, but I'm afraid I don't have any ETA.

[humptydumpty]

Thanks for asking. Would also be useful to be able to sniff for Bluetooth.

While I understand there are certification issues as far as radio transmission is concerned, I don't see why the radio functions have to be so undocumented on the reception side.