IEEE has recently released a new standard, IEEE 802.11az, that promises to significantly improve the accuracy of Wi-Fi location positioning. The current Wi-Fi location accuracy ranges from 1 to 2 meters, but the new standard aims to achieve accuracy to less than 0.1 meters. This improvement in accuracy opens up a range of possibilities for secure, authenticated, and private positioning.
One of the key features of the IEEE 802.11az standard is the ability to securely and authentically position devices. This means that users can set their computers to only open via their smartwatch when they are within inches of it, adding an extra layer of security. Similarly, this technology can also be applied to unlocking a vehicle’s door via a smart device, but only when the user is within a programmed distance, which can be less than a meter away. Additionally, smart devices can be used to make payments at the point of sale in a store or facilitate ATM transactions. The proximity of two devices enhances the authenticity guarantee and thwarts attacks from relays.
The primary function and importance of the IEEE 802.11az standard lie in its integration of positioning protocols into mainstream IEEE 802.11ax, also known as Wi-Fi 6. This integration brings several additional benefits, including security and authenticity, improved accuracy and coverage of 2x to 4x, 10x improved power efficiency, and scalability. It also takes advantage of the Wi-Fi ecosystem’s superior link budget for longer-range use and access to spectrum for long-term technology investment value.
In the context of the IEEE 802.11 series, the IEEE 802.11az standard holds evolutionary significance as the third generation of Wi-Fi positioning protocols. The first generation was based on RSSI (Received Signal Strength) and provided modest accuracy of 10-15 meters. The second generation, known as REVmc FTM (Fine Timing Measurement), is based on Time of Flight (ToF) and offers an accuracy of 1-2 meters. The REVmc FTM is already supported by multiple enterprise network vendors and is available on many mobile devices. The IEEE 802.11az standard is now entering the market as the third generation, enabling sub-1 meter accuracy. It also supports MIMO (Multiple Input Multiple Output antenna) and provides enterprise-grade MAC and PHY security. The further development of IEEE 802.11bk is expected to push the accuracy to sub-0.1 meter levels using 320MHz Wi-Fi 7 channels.
The IEEE 802.11az standard enhances security by introducing the PHY level anti-spoofing mechanism called Secure LTF. This mechanism provides multi-layer protection to prevent manipulation of over-the-air signals, such as Timing Advance attacks. The standard builds on the existing IEEE 802.11 Security framework and uses the same credentials and security scheme for connectivity to authenticate IEEE 802.11az peers’ protocol signaling. It also utilizes the Key Derivation Key (KDK) derived from the Pairwise Transient Key (PTK) for independent key generation and employs unique AES128 sequences for each Secure LTF transmission.
Energy efficiency and dynamic scheduling are also improved by the IEEE 802.11az standard. It allows for the modification of the measurement rate and the amount of measurements per channel access based on the momentary needs and conditions without service renegotiation. This variability in measurement rate and amount is useful for following rapid or sporadic movement by the client and compensating for outliers, all while preserving user experience and device responsiveness. The ability to vary the amount of measurement per channel access provides increased statistics, improving the Single to Noise Ratio (SNR) for reliable and spectrum-efficient estimation and enabling the identification of brute force attacks.
In the context of home Wi-Fi use, particularly in the presence of multiple APs and mesh networks, IEEE 802.11az can contribute by providing input to AP selection algorithms. This technology can also support services such as location detection and contextual information for IoT services, such as turning on lights when entering a room.
Overall, the release of the IEEE 802.11az standard represents a significant advancement in Wi-Fi location positioning. With its improved accuracy, secure authentication, and energy efficiency, it opens up new possibilities for a range of applications, from securing devices to enhancing home Wi-Fi networks. As this standard continues to evolve, we can expect even greater accuracy and advancements in the field of Wi-Fi positioning.