Level 1 of the Digital Mobile Radio (DMR) technology standard includes unlicensed devices of DMR Tier I for unrestricted operation in the PMR 446 megahertz range. Tier I devices are low-power unlicensed radio stations with a maximum transmitter output power rating of no more than 0.5 W, offering a limited number of channels, without repeaters, telephone interfaces, or external/fixed antennas. They are most suitable for private applications such as leisure areas, small shopping centers, and other tasks that do not require large coverage areas or advanced functionality.
Related articles: DMR, DMR Tier II, DMR Tier III, LPD, PMR (446.00625-446.09375 MHz), VHF, UHF (400-520 MHz).