Performance comparison of 802.11mc and 802.11az Wi-Fi Fine Time Measurement protocols

TL;DR

This study compares the ranging accuracy of 802.11mc and 802.11az Wi-Fi protocols, highlighting their performance in different environments and under various conditions, with 802.11az showing superior accuracy especially in complex environments.

Contribution

The paper provides a comprehensive real-world comparison of 802.11mc and 802.11az protocols, identifying key factors affecting accuracy and demonstrating the improved performance of 802.11az in challenging conditions.

Findings

Meter-level accuracy in line-of-sight with 80/160 MHz channels

Approximately 5m accuracy in non-line-of-sight environments

802.11az outperforms 802.11mc in multipath environments

Abstract

The need for meter level location accuracy is driving increased adoption of 802.11 mc/az Fine Time Measurement (FTM) based ranging in Wi-Fi networks. In this paper, we present a comparative study of the ranging accuracy of 802.11mc and 802.11az protocols. We examine by real world measurements the critical parameters that influence the accuracy of FTM {\it{viz.,}} channel width, interference, radio environment, and offset calibration. The measurements demonstrate that meter-level ranging accuracy can be consistently attained in line of sight environment on 80 MHz and 160 MHz channels, while an accuracy of about 5m is obtained in non-line of sight environment. It is observed that the 802.11az protocol is capable of providing better accuracy than 802.11mc even in a multipath heavy environment.