Which Atheros chip for Distance Measuring

[Florian Adamsky]

Hi all,

in one of our projects we need to measure the distance between two
802.11 devices as accurately as possible. Our idea is to use the
round-trip time (RTT). To avoid any delay from the operation system and
from the network stack, our idea is to measure the arrival time of the
acknowledgment control frame.

After watching Adrias talk [1] at Defcon 22, I'm convinced that the
Atheros chip is the best for this job. In this talk, he said that the
AR9380 and later support various higher resolution methods for packet
timestamps. However, in the source code it looks like that only AR6K [2]
supports high frequency timestamp. Which chip do I need to get the high
frequency timestamps? Maybe you even have a recommendation for a
wireless card on which the UART pins are easily reachable or debugging.

I'm grateful for any other hints for our project.

Best regards

Links:
[1] https://www.youtube.com/watch?v=WOcYTqoSQ68
[2]
https://github.com/qca/open-ath9k-htc-firmware/blob/master/target_firmware/magpie_fw_dev/target/inc/OTUS/OTUS_soc.h#L179
--
Dr. Florian Adamsky
http://florian.adamsky.it/