subGHz

SubGHz, or sub-GHz, refers to the portion of the radio frequency spectrum below 1 gigahertz that is used for wireless communications. It includes bands such as 315 MHz, 433 MHz, 868 MHz in Europe, and 902–928 MHz or 915 MHz in North America, among others. Many subGHz bands are allocated as unlicensed or lightly licensed spectrum for industrial, scientific, and medical uses, with regional regulatory rules guiding power limits and duty cycles.

The propagation characteristics of sub-GHz signals favor long-range coverage and better penetration through walls and obstacles compared with higher-frequency bands. This makes subGHz attractive for low-power, wide-area applications such as IoT and remote sensing, where data rates are modest and battery life is important. Antenna size and design are influenced by the lower frequency, and link budgets are typically favorable at longer distances.

Regulatory landscapes vary by region. In the United States, bands such as 902–928 MHz are used under Part 15 unlicensed rules with power and duty-cycle limits. In Europe, 863–870 MHz is commonly used, with regional variants and CEPT/ETSI requirements. Other regions use 865–867 MHz, 915–928 MHz, or similar allocations. SubGHz technology encompasses a range of modulation schemes and technologies, including LoRaWAN and Sigfox for low-power wide-area networks, as well as proprietary FSK, GFSK, MSK, or OOK schemes for specific applications. LoRaWAN, for example, operates in 868 MHz in Europe and 915 MHz in the US.

Applications span remote telemetry, asset tracking, smart metering, agricultural sensing, and building automation. SubGHz networks offer extensive coverage with relatively low data rates, making them suitable for scalable, battery-powered IoT deployments in rural, industrial, and indoor environments.

Challenges include spectrum sharing and interference, regulatory compliance, and the need for efficient antennas and power management to maximize reach and reliability.