sub GHz area

Sub-GHz frequencies are frequencies below 1 GHz that are used for wireless technology. While various WLANs, such as 802.11, Bluetooth and ZigBee, operate in the license-free ISM bands in the gigahertz range at 2.4 GHz and 5 GHz, other radio technologies take advantage of radio transmission in frequency ranges below 1 GHz.

The sub-GHz frequencies can be the license-free ISM bands at 433 MHz, 868 MHz( EU) or 915 MHz (USA), but also the frequencies released by the digital dividend between 790 MHz and 860 MHz.

The decisive factor for the use of sub-GHz frequencies is the radio advantages offered by the certified White Spaces Devices(WSD). Frequencies below 1 GHz have lower free- space attenuation compared with microwaves and are therefore suitable for data transmission at low data rates over long distances. For example, a frequency of 900 MHz has a level advantage of 8.5 dB over microwaves of 2.4 GHz at the same distance. Since sub-GHz frequencies thus have low power consumption, these frequency ranges are used for low-power WANs, but also for sensor networks, smart metering and alarm systems.

The disadvantage is that the usable channels in the sub-gigahertz range are narrow and the frequency bands can be different in different regions.