What is ISM Frequency?
Industrial applications typically operate in “license free” frequency bands, also referred to as ISM (Industrial, Scientific and Medical). No license is required to operate 900MHz devices within the USA, and the FCC approves them. The frequencies and power of these bands varies from country to country. The most common frequencies encountered are: • 2.4 GHz – nearly worldwide • 915 MHz band – North America, South America, some other countries • 868 MHz band – Europe As frequency rises, available bandwidth typically rises, but distance and ability to overcome obstacles is reduced. For any given distance, a 2.4 GHz installation will have roughly 8.5 dB of additional path loss when compared to 900 MHz.
