Level 1 of the Digital Mobile Radio (DMR) technology standard includes non-licensed communication units of DMR Tier I for unrestricted operation in the PMR 446 MHz range. Tier I devices are low-power non-licensed radio communication tools with a transmitter power of no more than 0.5 W, offering a limited number of channels, without repeaters, telephone interfaces, or external/fixed antennas. They are best designed for personal use 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 (433.075-434.775 MHz), PMR, VHF (134-174 MHz), UHF.