Equivalent of a radiotap header to extract rssi

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MaGr_2160016
Level 4
Level 4
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I am using a WICED module in monitor mode filtering for probe requests. I can capture the 802.11 probe request frames but I could not figure out how to obtain the information - specifically the SSI signal - as typically found in the radiotap header.

I understand radiotap is not a standard, and is only a functionality of the driver. Nevertheless, I would appreciate any information on how I can extract the SSI fields in some way through the SDK. I am comfortable in using non-standard and not documented functions, as I am sure such information must be available. I had to resort to non documented functions in the SDK to enable and take advantage of monitor mode in the first place.

Unfortunately, wiced_get_rssi() inside a capture callback host_network_process_raw_packet(), times out. I tried also disabling any filters and in running it from another thread, but it doesn't seem to be working in monitor mode. Perhaps accessing the radio registers is what is needed. I am specifically interested in the RSSI only.

Thanks in advance.

-Marco G.

3 Replies
SeyhanA_31
Employee
Employee
250 replies posted 100 replies posted 50 replies posted

Hi,

The scan results structure wiced_scan_result_t includes the signal_strength.

For sample code process_scan(...) uses the signal_strength to display signal level in .../apps/wwd/appliance/AP_content.c file.

Seyhan

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Seyhan,

Thank you for the reply. However, I am not doing a WiFI scan, I am

receiving packets from devices with the WICED module in monitor mode. More

specifically, I am capturing 802.11 device probes and I would like to know

the signal strength of the devices sending the probes. In the buffer

received from devices with the MAC header, I see 32 bytes before the header

where a radiotap or equivalent probably is. What is the format of those 32

bytes or where else the sending device signal strength can be retrieved?

Cheers,

-Marco G.

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GregG_16
Employee
Employee
50 sign-ins 25 sign-ins 25 comments on KBA

Hi Marco,

This feature is not available in WICED today. It would take some time to scope the effort and allocate resources If it is feasible. Please send me a private message @gangi and we can discuss more.

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