Level 3 of the Digital Mobile Radio (DMR) standard includes trunked DMR Tier III systems – professional trunked radio communication systems operating in licensed frequency ranges from 66 to 960 MHz. The ETSI DMR Tier III standard defines a 2-slot TDMA mode within a single 12.5 kHz radio channel. Tier III systems support voice calls and short text messaging, similar to MPT1327 systems, with an integrated system of 128-character status messages and short messages up to 288 bits of data in several different formats. Packet data transmission services are also supported in various formats, including support for IPv4 and IPv6 protocols.
Related articles: DMR, DMR Tier I, DMR Tier II, LPD, PMR (446.00625-446.09375 MHz), VHF, UHF (400-520 MHz).