Wi-SUN Alliance Certifies Silicon Labs’ Wi-SUN SoC for Smart Metering

February 14, 2023 by Jake Hertz

Silicon Labs' Wi-SUN SoC is now available and fully certified by the Wi-SUN Alliance for smart city applications.

In the IoT and smart city industries, a historical problem has been rampant industry fragmentation and interoperability issues. Silicon Labs, a leader in smart city hardware, recently announced a new Wi-SUN-enabled SoC and the SoC’s certification by the Wi-SUN Alliance.



Silicon Labs' Wi-SUN SoC ERF32FG25 has been certified by the Wi-SUN Alliance. Image (modified) courtesy of Silicon Labs


What Is Wi-SUN?

Wi-SUN (Wireless Smart Utility Network) is a wireless communication technology designed specifically for smart cities and the Internet of Things (IoT) applications. The protocol is an open standard that has been developed and maintained by the Wi-SUN Alliance, an organization consisting of more than 200 IoT and wireless industry leaders across the world. Wi-SUN addresses interoperability issues by providing a single, standardized solution that enables different types of devices to connect to the same network, regardless of their manufacturer or application.


Example of a Wi-SUN Field Area Network

Example of a Wi-SUN Field Area Network (FAN). Image courtesy of Silicon Labs


The Wi-SUN standard is based on the IEEE 802.15.4g wireless communication protocol and supports mesh networking, which allows devices to communicate with each other directly or through intermediate nodes, forming a self-organizing, resilient network. The technology operates on the sub-gigahertz frequency band, which provides greater range and penetration than higher frequency bands, making it suitable for outdoor and indoor environments.

Another key advantage of Wi-SUN is its ability to support large-scale deployments. By using mesh networking and optimizing power consumption, Wi-SUN can create networks that cover entire cities or regions, making it a useful technology for smart city applications such as street lighting, traffic management, and environmental monitoring.


SiLabs’ FG25 Gets Stamp of Approval

In Sept. 2022, Silicon Labs announced a new Wi-SUN-compatible SoC. Now, the company is making waves again by announcing that the FG25 has been fully certified by the Wi-SUN Alliance and that the SoC is now fully available for purchase.

That new device, the ERF32FG25, is a low-power wireless SoC designed explicitly for use in smart city applications. From a computing perspective, the device is built around a 32-bit, 97.5 MHz Arm Cortex-M33 core, including DSP instruction and a floating-point unit (FPU) for signal processing tasks. The SoC also features up to 1920 kB of flash program memory and 512 kB of RAM.


ERF32FG25 block diagram

ERF32FG25 block diagram. Image courtesy of Silicon Labs (Click to enlarge)


From a connectivity perspective, the device features a Wi-SUN-compatible high-performance transceiver. Featuring Wi-SUN multi-rate OFDM, FSK, and O-QPSK modulation, the device is said to achieve data rates up to 3.6 Mbps while maintaining immunity to 2.4 GHz interference. The device also offers deep sleep power modes as low as 2.6 uA on the low end and TX power of up to 186 mA TX current at 16 dBm output power and 914 MHz (2.4 Mbps Wi-SUN OFDM).

Altogether, the SoC aims to enable long-range, high throughput, and low latency in sub-GHz Wi-SUN applications. As a testament to this goal, Silicon Labs recently announced that Landis+Gyr has already used the SoC successfully in smart metering applications