Which of these amateur radio bands may be heavily occupied by licence-exempt devices?

The 902 MHz to 928 MHz band is globally designated for Industrial, Scientific, and Medical (ISM) purposes. In addition to ISM equipment, this frequency range is allocated for various licence-exempt consumer devices. Because it does not require a specific license for consumers to use, you will find this band heavily occupied by everyday devices such as cordless phones, baby monitors, smart utility meters, and wireless home networks. When amateurs operate in this band, they must do so on a secondary basis, meaning they must accept interference from these countless licence-exempt devices. The other bands listed (like 80m, 70cm, or the 2200m band) are not heavily populated by consumer licence-exempt wireless gadgets.