Digital Mobile Radio (DMR) is a land-mobile radio network standard developed by the European Telecommunications Standards Institute (ETSI). DMR is used by thousands of professional land-mobile radio networks worldwide.
A wide variety of DMR mobile, base and portable equipment is available from numerous manufacturers.
DMR uses Time Division Multiple Access (TDMA) to provide two 30 ms “slots” per 12.5 kHz radio channel.
Each slot can carry independent voice conversations – this means that each DMR repeater provides two simultaneous voice channels – illustrated in the diagrams below: