What is IEEE 802.11az | Advantages of 802.11az WiFi Standard

This page covers IEEE WiFi 802.11az standard features. It mentions benefits or advantages of 802.11az WiFi used as micro-location positioning.

What is IEEE 802.11az WiFi ?

Bluetooth 5.1, UWB (Ultra Wide Band ) and 802.11az technologies are used for micro-location positioning. There are various uses of these micro-location technologies. The applications include finding things at homes and warehouses, detecting cars and their parts, auto following drones, prevention of accidents etc.

The IEEE 802.11az wifi standard defines ToA (Time of Arrival) based position estimation algorithm for WiFi clients (i.e. STATIONS) in multi-path environment. This standard helps Station (STA) to identify its position in a wifi network with respect to multiple APs (Access Points) or Routers.

This 802.11az amendment defines modifications to PHY layer and MAC layer. In comparison to previous IEEE standard i.e. 802.11-2016, 11az enables absolute as well as relative position estimation with high accuracy. It is known as next generation positioning (NGP) standard which is planned to be finalized by 2022. Unlike RSSI based positioning, this NGP standard uses Fine Timing Measurement (FTM) method to determing position of WiFi STA.

WiFi 802.11az ToF Measurement

The figure depicts ToF (Time of Flight) measurement and range calculation.
➨ToF = [ (t4-t1) - (t3-t2)]/2
➨Range = Speed of light x ToF

Following are the features of 802.11az micro-location technology.
• Defines two PPDU formats viz. HE ranging NDP & HE trigger based ranging NDP (Null Data Packet).
• Uses multiple repetitions of HE-LTF symbols in single user waveform and multi user waveform.
• Employs FTM which uses RTT (Round Trip Time) information to estimate distance between Wi-Fi enabled STAs (i.e. clients or stations) and WiFi APs (access points). RTT uses ToD (Time of Departure) and ToA (Time of Arrival) timestamps.
• It utilizes wide bandwidth channels (up to 160 MHz in WiFi 6 version and up to 320 MHz in WiFi 7 version) for providing improvement on accuracy in positioning.
• It utilizes multi-user capabilities as defined in WiFi 6 version.
• APs use OFDMA in the uplink and downlink and trigger based ranging to get ranging information from multiple STAs in single transmit opportunity.

Benefits or advantages of 802.11az

Following are the benefits or advantages of 802.11az technology :
➨It improves location and positioning of the wifi users. Hence WiFi router quickly tracks precise location of WiFi clients accurately.
➨This standard increases energy efficiency of the wifi network.
➨It reduces wireless medium utilization.
➨It is scalable to dense deployment environments.
➨It incorporates security features.
➨It offers higher resolution due to use of wider bandwidth channels.
➨It uses MIMO to provide better resilience to multi-path effects.
➨Trigger based ranging reduces overhead to significant extent and improves scalability to more STAs (i.e. stations).

Out of three technologies, UWB provides highest accuracy with centimeter level positioning. Bluetooth 5.1 offers sub-meter level accuracy and 802.11az based WiFi offers decimeter level accuracy.

Also refer Difference between WiFi 5 and WiFi 6 >> and advantages and disadvantages 802.11ac >> technology.

WLAN 802.11 ax i.e. WiFi 6 tutorial related links

802.11n versus 802.11ax
802.11ac versus 802.11ax
802.11ax wave1 vs wave2
Advantages and disadvantages of 802.11ax
BSS coloring in 11ax
RU in 802.11ax
MU-OFDMA in 802.11ax
MU-MIMO in 802.11ax
TWT power save mode in 802.11ax
EVM specification in 802.11ax
802.11ax Speed calculator

BLE (Bluetooth Low Energy) Links

Bluetooth v5 versus v5.1 >>
Bluetooth v4.2 versus v5.0 >>
BLE states and state diagram >>
BLE advertising and data channels >>
BLE protocol stack architecture >>
BLE connection process >>
BLE advertising and data packet formats >>

UWB Links

UWB tutorial
UWB Radar System tutorial
UWB Frequencies, Bandwidth and EIRP
Advantages and disadvantages of UWB


What is wlan?
WLAN standards-11a,11b,11g,11n,11ac
11a WLAN Physical layer
11b WLAN Physical layer
11n WLAN Physical layer
WLAN 802.11-ac
WLAN 802.11-ad
Difference between 11a,11b,11g,11n
WLAN router providers
WLAN providers

Advantages and Disadvantages of other wireless technologies

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difference between OFDM and OFDMA
Difference between SC-FDMA and OFDM
Difference between SISO and MIMO
Difference between TDD and FDD

RF and Wireless Terminologies