Convergence is Coming for Smart Cities, and Certified Wi-SUN FAN 1.1 LE is Ready

Smart cities are no longer built around a single application. Electric meters, streetlights, water and gas infrastructure, parking systems, grid automation equipment, and environmental sensors require secure, scalable connectivity. But all these device types operate under vastly different power conditions. Some are line-powered and always on, while others are expected to function reliably for up to 20 years on a single battery.

Historically, this divide forced utilities and municipalities into difficult architectural trade-offs. Separate networks were often deployed for powered and battery-operated devices. Battery life was compromised to maintain high-performance mesh participation. Operational complexity increased as multiple security domains and infrastructure overlays had to be managed.

At scale, these decisions significantly increase capital and operational expenditure, expand cybersecurity exposure, and introduce vendor lock-in risks.

Wi-SUN FAN 1.1 Low Energy (LE) fundamentally changes this model.

Wi-SUN FAN 1.1 Low Energy: One Mesh. One IPv6 Domain. One Security Model.

Wi-SUN FAN 1.1 LE enables both line-powered infrastructure nodes and ultra-low-power endpoints to operate within a single, standards-based sub-GHz RF mesh network.

This architecture represents true convergence:

• Line-powered full-function nodes (FFNs) form a resilient mesh backbone.
• Battery-powered low-energy nodes securely participate in the same IPv6-based network.
• Security, onboarding, and device management remain unified.

The result is a single, consolidated infrastructure in which electric meters, water meters, streetlights, and distributed sensors coexist seamlessly. Streetlights can route traffic for neighborhood sensors, grid-edge devices can anchor connectivity across entire districts, and cities no longer need to design networks around device power constraints.

Why Wi-SUN Convergence Matters

Smart city infrastructure is a decades-long investment. Running parallel technologies for different device classes increases total cost of ownership, complicates integration, broadens attack surfaces, and limits procurement flexibility.

By converging infrastructure and endpoints onto a single Wi-SUN FAN 1.1 LE network, cities and utilities benefit from:

• Lower total cost of ownership
• Simplified network operations
• Consistent, end-to-end security policies
• Multi-vendor interoperability
• Long-term architectural stability

Architectural simplicity is more than technical elegance, it directly reduces financial and operational risk. FAN 1.1 LE is no longer an experimental technology; it’s certified, standards-based, and commercially ready.

Wi-SUN FAN 1.1 LE Certification Enables Confident Deployment

Convergence only works if interoperability is guaranteed. The Wi-SUN Alliance FAN 1.1 LE Certification Program ensures devices are validated within a multi-vendor ecosystem. This reduces vendor lock-in risk, preserves procurement flexibility, and strengthens long-term infrastructure resilience.

Silicon Labs Platforms for Converged Wi-SUN Networks

Delivering converged Wi-SUN infrastructure requires silicon platforms optimized for different roles within the mesh.

EFR32FG25: High-Performance Backbone Infrastructure

The EFR32FG25 wireless SoC is designed for border routers and line-powered FFNs forming the mesh backbone. With support for both OFDM and FSK PHYs, strong sub-GHz RF performance, substantial memory resources, Mode Switch function, and Secure Vault™ security, FG25 is well-suited for routing-intensive, always-on deployments. In large-scale, high-density city networks where OFDM capacity is required, FG25 provides a robust foundation.

EFR32FG28: Flexible Platform for FFN and LE Designs

The EFR32FG28 sub-GHz SoC supports both High-Performance (HP) and Low-Energy (LE) Wi-SUN FAN 1.1 profiles using FSK PHY. It enables developers to build line-powered FFNs for moderate-scale deployments as well as battery-powered LE Nodes for energy-sensitive applications.

With low active and sleep currents, strong sub-GHz RF performance, scalable processing capability, and integrated security, FG28 is ideal for water and gas metering, environmental sensing, and distributed monitoring applications. For bandwidth-moderate use cases where long battery life is critical, FSK-based FAN 1.1 implementations provide the optimal balance of coverage, efficiency, and performance.

Together, FG25 and FG28 form a unified silicon foundation for converged Wi-SUN networks.

Deploy Converged Smart Infrastructure Today with Wi-SUN FAN 1.1 LE

With certified Wi-SUN FAN 1.1 stack support, development kits, reference designs, Simplicity Studio tools, and integrated security, Silicon Labs enables utilities and municipalities to deploy scalable, secure Wi-SUN mesh networks today.

Wi-SUN FAN 1.1 LE, which is deployable now, closes the long-standing gap between high-performance infrastructure and ultra-low-power endpoints without fragmenting the network.

Converged smart city infrastructure is no longer a future concept.