Wi-Fi RTT (IEEE 802.11mc) on ESP32

[r.saprykin]

Good day.
Some time ago was thread:

Tue Mar 13, 2018 5:33 am
Re: What would you like to see in The Next Chip?
Wi-Fi RTT: We actually have a fair bit of the hardware needed for something like this already; we just haven't had any requests from big customers to write the added driver support for it (at least, that's what I understand); also, I'm not sure if hardware support actually has been tested in any way; for all we know it may be broken. Don't be surprised if something like this pops up in esp-idf in an upcoming version, however.

Does it mean we can expect software support Wi-Fi RTT (IEEE 802.11mc)protocol in esp-idf on ESP32 in the near future?

Does ESP32 has hardware support or capability for Wi-Fi RTT (IEEE 802.11mc) protocol?

Thanks
Roman

[littlesky]

esp-idf has supported channel state information which is the basis of WiFi RTT since idfv3.1. But protocol stack of WiFi RTT is not supported yet. For channel state information, please refer to WiFi documentation wifi.rst in esp-idf directory.

[r.saprykin]

Thanks for your replay.

We plan to buy a small set of ESP32 chips for our project and need to be sure that protocol stack of WiFi RTT will be implemented in esp-idf.
Could you please tell an approximated time of protocol stack of WiFi RTT will released?

Thanks.
Roman

[ESP_Sprite]

I can ask around, but I'm not sure if there are any plans to implement 802.11mc.

[r.saprykin]

It would be very helpful if you could ask around and clarify the perspective of protocol stack Wi-Fi RTT (IEEE 802.11mc) on ESP32 implementation.


Big thanks
Roman

[littlesky]

Would you like to use WiFi RTT for distance measurement? ESP32 does not support it and there is no plan to implement it now. We suggest to use channel state information which can also be used to measure distance. And it is already supported in esp-idf.

[r.saprykin]

Thanks for your reply.

Do you have some examples or documentation on how to use channel state information for distance measurement in esp-idf for ESP32?

[littlesky]

We have document WiFi.rst for how to get channel state information. But we haven't document or example for how to use it to measure distance. Distance measurement is just one of the specific applications of channel state information, so it is not much possible to describe it in IDF.

[MrDev13]

Hi, please, could you clarify. Is it means that I can reach the same accuracy as the WIFI RTT approach (FTM protocol)?

I read "Wi-Fi Channel State Information" but not sure how could I calculate the distance. I found timestamp in wifi_pkt_rx_ctrl_t but it is in microseconds. This is not enough for accurate round trip time measurement. Please, provide the direction where I have to dig.

Thanks!