Advantages of 802.11ax | disadvantages of 802.11ax, Wifi-6
This page covers advantages and disadvantages of 802.11ax (i.e. wifi-6). It mentions 802.11ax advantages or benefits and 802.11ax disadvantages or drawbacks.
What is 802.11ax or Wifi-6?
• IEEE 802.11ax technology is 6th generation of WiFi and hence it is known as Wifi-6. Due to its high efficiency performance, it is also known as HEW (High Efficiency WLAN).
• It is developed to overcome limitations of 802.11ac such as contention based uplink access etc.
• 802.11ax offers better efficiency, network capacity, performance and user experience at reduced latency.
Image Courtesy: Ruckus Networks
Following are the features of 802.11ax.
• Higher modulation scheme such as 1024-QAM
• More number of OFDM subcarriers in a symbol or long OFDM symbol
• Multiplexing users using MU-MIMO concept both in the uplink and downlink
• Beamforming and OFDMA technique
• 8 simultaneous MU-MIMO streams
• Uplink scheduling without any contention
• BSS color codes
• Use of both 2.4 GHz and 5 GHz bands
• Refer WLAN 802.11ax tutorial >>
802.11ax physical layer supports different bandwidth options such as 20 MHz, 40 MHz, 80 MHz, 80+80 MHz and 160 MHz. It supports FFT sizes e.g. 256, 512, 1024 and 2048. The subcarrier spacing is 78.125KHz. The symbol duration is 12.8 µs + 0.8/1.6/3.2 µs CP.
Benefits or advantages of 802.11ax
Following are the benefits or advantages of 802.11ax:
➨It has been developed to deliver 40% high peak data rates using single client device. Average throughput per user is improved by at least 4 times in dense environments.
➨It offers four times increase in network efficiency compare to 802.11ac.
➨It is backward compatible with 802.11n and 802.11ac devices.
➨It uses OFDMA and hence multiple users can transmit at the same. The OFDMA based scheduling helps in reducing overhead and latency both.
➨The battery life of 802.11ax client devices have been enhanced due to introduction of new feature called TWT (Target Wake Time). TWT feature allows client devices to sleep and wake up at scheduled times.
➨Mitigation of co-channel interference is possible using BSS color codes. This codes help 11ax stations to identify transmission from another network.
➨It offers robust high efficiency signaling for better operation at significantly lower RSSI.
➨It performs well both the the indoor and outdoor environments. To achieve the same, it uses longer symbol duration and cyclic prefix (CP) in outdoor environment where as it uses shorter CP in indoor environment.
Drawbacks or disadvantages of 802.11ax
Following are the drawbacks or disadvantages of 802.11ax:
➨OFDM subcarrier spacing is narrower at 78.125 KHz. This means good phase noise oscillators and highly linear RF front ends are essential.
➨As 1024-QAM is used to achieve higher data rates, EVM specification is tight.
➨Tight frequency synchronization and clock offset correction are required to achieve better performance.
➨Moreover 802.11ax stations maintain frame timing based on their clocks. This is essential as their transmissions should be as per trigger frames and scheduling.
➨At the time of writing this page, 802.11ax is in draft stage. This will be the major hurdle for developers working on the product design to meet the market demand.
Also refer advantages and disadvantages of 802.11ac >>.
WLAN 802.11ax 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
WLAN RELATED LINKS
What is wlan?
11a WLAN Physical layer
11b WLAN Physical layer
11n WLAN Physical layer
Difference between 11a,11b,11g,11n
WLAN router providers