ISM band
termnetworking
Stands for: industrial, scientific and medical band
Industrial, scientific and medical bands: spectrum usable without an individual licence, subject to power and interference rules.
These allocations made consumer wireless possible. Wi-Fi and Bluetooth share 2.4 GHz with microwave ovens and much else, which is exactly why that band is congested, and the 5 and 6 GHz Wi-Fi bands trade range for room. LoRa takes the opposite bet in the sub-GHz ISM allocations, accepting very low data rates to get kilometres of range and years of battery life. Licence-exempt does not mean rule-free: duty cycle and power limits are what keep the bands usable.
Also known as: unlicensed spectrum, 2.4 GHz, licence-exempt