In this segment from Elektor Engineering Insights 17 – Low Power for IoT, Stuart Cording talks with Dhiraj Sogani of Silicon Labs about how low-power Wi-Fi 6 finally makes lower power designs practical. Wi-Fi has long been seen as the worst choice for battery-powered IoT, but the specification has changed.

Why Wi-Fi 6?

Traditional Wi-Fi was built for laptops and smartphones. IoT devices have very different requirements: small microcontrollers, tight energy budgets, and long sleep intervals. As Sogani notes, simply reusing “normal Wi-Fi” for IoT leads to poor results. Silicon Labs redesigned its first-generation RS9116 (Wi-Fi 4) solution from the ground up for low-power operation, and Wi-Fi 6 extends that further.


Two features in Wi-Fi 6 are central to low-power IoT:

  • Target Wake Time (TWT): Devices negotiate long sleep intervals with the access point, allowing them to wake only when needed.
  • OFDMA: More efficient channel use and fewer collisions reduce retransmissions, further lowering energy use.


These mechanisms let sensors sleep for minutes instead of milliseconds, while maintaining an active connection and avoiding full re-authentication cycles. Designers can still shut down everything for ultra-rare transmissions, but the point is choice: the radio and MCU subsystems can be selectively powered depending on the use case.

Keeping it Clean

Sogani also discusses interference — an unavoidable factor in homes, offices, and factories. Wi-Fi 6’s improved spectrum efficiency helps reduce retries, which directly saves power. Device placement, channel selection, and coexistence with 2,4 GHz technologies such as BLE also influence battery life.
 

In terms of practical evaluation, Silicon Labs supports engineers with data sheets, power-estimation spreadsheets, and hardware that includes automated energy-measurement capabilities. Accurate profiling is essential when current consumption jumps between microamps and milliamps in real-world duty cycles.
 

Finally, Sogani introduces Silicon Labs’ SiWx917, an ultra-low-power Wi-Fi 6 + Bluetooth LE SoC. It integrates the Wi-Fi stack, BLE stack, a network processor, a Cortex-M4 application core, and an on-chip ML accelerator for tasks such as keyword spotting. According to Sogani, it delivers the lowest Wi-Fi 6 power consumption in its class.
 

Demonstrations were shown of the SiWx917 running Matter over Wi-Fi, Matter-over-Thread with the MG24/BG24 families, bridging demonstrations for Zigbee/Z-Wave devices, the new BG27 Bluetooth device, Bluetooth high-accuracy distance measurement, and new MCU announcements.
 

Simplicity Studio IDE

Silicon Labs’ unified Simplicity Studio IDE supports all of these platforms and provides consistent tools for wireless stacks, power tuning, and application development.