What is 900 MHz used for

The 900 MHz radio system is at a lower frequency and will penetrate surfaces more easily ; while 2.4 GHz systems are more reflective and tend to be affected more by buildings, foliage or moisture that can attenuate the signal.

Higher frequencies can use less power, but will reflect off of dense surfaces. The 900MHz radio system is at a lower frequency and will penetrate surfaces more easily . Tempest 2.4GHz systems are more reflective and tend to be affected more by bodies, foliage, or moisture that can attenuate the signal.

Comparison of radio band designation standards FrequencyIEEEITUno.30 MHzVHF8250 MHz300 MHzUHF9Radio spectrum – Wikipedia en.wikipedia.org › wiki › Radio_spectrum