Power limitations
Wi-Fi appears to be the perfect option for wireless networks needing greater range than short-range, low-power protocols, but not the huge of range of the WAN technologies.
Closer inspection reveals Wi-Fi has some considerable drawbacks for IoT applications.
The first challenge is power consumption.
Wi-Fi was designed for high throughput with little regard for power consumption.
In contrast, IoT wireless technologies typically try to limit on-air time to extend battery life and hence minimize maintenance.
Interference
Second, Wi-Fi struggles in dense deployment scenarios like busy malls and libraries.
For Industrial networks comprising hundreds of sensors, reliability is important.
Orthogonal frequency-division, multiple-access
Wi-Fi 6 (IEEE 802.11ax), addresses the shortcomings that have hampered the technology’s widespread adoption for the IoT.
Approved by the Wi-Fi Alliance in early 2021, Wi-Fi 6 was designed to meet the requirements of dense deployments, both public and industrial.
The new orthogonal frequency-division, multiple-access (OFDMA) feature allows devices to use less than one channel bandwidth, sharing the bandwidth with other devices on the network, also enabling faster response to and from connected units.
Where previous versions of Wi-Fi struggled to cope with more than a few sensors, Wi-Fi 6 can comfortably manage large sensor networks comprising hundreds of devices.
Target wake time
Wi-Fi 6 also brings a key technical enhancement for smart-home and -industry applications.
Target wake time (TWT) is another technical enhancement to power-saving efforts of prior generations of Wi-Fi.
When using TWT, client devices negotiate wake-up times with access points (APs).
Therefore, the clients don't need to stay awake to maintain the wireless connection.
The benefits are more efficient, contention-free channel access, and significant client-device power savings up to 80%.