NRF700X wifi beacon scrambler seed

[JasonJ]

Hi, I am having issues with one of our wifi scanning modules not detecting the wifi beacon using the 1M rate. Looking into the PHY level, I demodulated different wifi beacons and only the NRF700X had a different scrambled preamble. It seems the NRF700X isn't using the specified scrambler seed according to this section of the wifi spec.

Can you confirm?

Is this something that can be fixed with a software update?

Regards,

Jason

[Charlie]

Hi Jason,

Thank you for bringing this issue to our attention.

I will forward it to our development team for further investigation and will get back to you as soon as I have more information.

Best regards,

Charlie

[Charlie]

Hi Jason,

To better understand your issue, could you please clarify the following:

1. What specific pattern are you observing?
2. What chipset are you using in your scanning device?

These details will help us investigate further and provide more targeted assistance.

Best regards,

Charlie

[JasonJ]

Hi Charlie,

I would just like for you to confirm the scrambler seed (from the IEEE standard 802.11 clauses 16 & 15, see original image) used by the nRF700X when beaconing at the 1M rate.

[Charlie]

Hi Jason,

According to our development team, the current scrabler seed is 0x5a and can be fixed with the firmware update. Could you please send us the NCS version so we can provide the fix?

on the issue, the Receiver is expected to demodulate with any scrambler as per the spec

Best regards,

Charlie

[JasonJ]

Great, I am using NCS v2.8.0.

Yes, we are looking to get it fixed on the receiver side as well.

[Charlie]

Hi Jason,

Raised the upstream PR and here are the details:

   nrfxlib : nrf_wifi: Update RPU patch to rev#682070c3fec by karun2796 · Pull Request #1632 · nrfconnect/sdk-nrfxlib

   nrf_wifi : nrf_wifi : Update Wi-Fi FW blobs by karun2796 · Pull Request #19 · zephyrproject-rtos/nrf_wifi

   zephyr : manifest: Update nrf_wifi for DSSS scrabler encoded as per IEEE spec by karun2796 · Pull Request #83896 · zephyrproject-rtos/zephyr

Note that fixes are in bin files and will not be useful for NCS 2.8.0.

We are pareparing a patch on top 2.8.0 branch and will share with you soon.

Best regards,

Charlie

[JasonJ]

Hi Charlie,

This has resolved the issue. Thank you. I tested the 'offloaded raw tx' bin file (replaced the bin file and updated the rpu patch number in NCS 2.8.0).

Are these bin files also compatible with the wifi driver in NCS 2.9.0?

[Elfving]

Hi, Charlie is currently OOO, so I will take over the case in the meantime.

Here are the new bin files Charlie referred to. They are for NCS 2.8.

5008.ncs.zip

Note that the fixes are in binaries and must be replaced in the codebase. Please overwrite the folder nrfxlib/nrf_wifi/bin/ncs with the attached folder.

Regards,

Elfving

[Elfving]

JasonJ said:

Are these bin files also compatible with the wifi driver in NCS 2.9.0?

The ones I sent you are not, though this one is.

ncs_2.9.zip

Regards,

Elfving