DMR (Digital Mobile Radio) is a digital radio standard developed by the European Telecommunications Standards Institute (ETSI), which was first approved in 2005.
The DMR Association is a consortium comprising the leading manufacturers of DMR products; key equipment suppliers include Motorola, Hytera, Selex, and Tait. The consortium's principal members are CML, Funkwerk Koelleda, Fylde, Hytera, ICOM, KENWOOD, MOTOROLA, Team Simoco, SELEX, Tait, and Vertex.
The DMR standard was drafted to address the needs of the mid-to-low-end professional and commercial markets, making it suitable for sectors such as public utilities, schools, hospitals, hotels, and property management.
The DMR standard employs a TDMA (two-time-slot) multiple-access scheme, which utilizes Time Division Multiplexing (TDM) technology to divide a single 12.5 kHz channel into two independent time slots. This enables the system to support two simultaneous voice calls-or one voice call and one data stream-on a single frequency. The standard features a 12.5 kHz channel spacing, 4FSK modulation, and a data transmission rate of 9.6 kbps. It defines three operational modes: unlicensed direct mode (Tier I), licensed conventional mode (Tier II), and licensed trunked mode with support for centralized dispatch (Tier III).
