The Digital Mobile Radio (DMR) standard is a digital radio standard developed specifically for professional mobile radio users by the European Telecommunications Standards Institute (ETSI). It was initially approved in 2005 with the goal of meeting the requirements of commercial and industrial users.
The first-level equipment is for low-cost digital walkie-talkie applications.
The second-level equipment is prepared for professional modes such as peer-to-peer mode and relay mode.
The third-level equipment is for professional cluster communication mode, in which the first- and second-level equipment use confirmed and unconfirmed data transmission services, and short data transmission services.
For third-level equipment, confirmed and unconfirmed data transmission services are used on the business channel, while short data transmission services are used on the control channel. Despite being based on open communication standards, they have different protocols and target markets and are technically incompatible.
The digital technology used in DMR management can better suppress noise, especially at the edge of coverage, providing better voice quality than analog technology. These advantages are due to the use of narrowband codecs and digital error correction technology.
Digital processing can filter noise and reconstruct signals from degraded transmissions, making user communication clearer. DMR improves the reasonable and effective coverage range of wireless communication, allowing users to easily adapt to changing work conditions on-site.
Another advantage of DMR technology is that only one repeater, one antenna, and one duplexer are needed to have two channels. Compared with FDMA, the dual-slot TDMA can achieve twice the bandwidth efficiency of 6.25 kHz while minimizing investment in repeaters and combination equipment.
Dual-slot TDMA only needs to use a single frequency point device to achieve a stable channel, eliminating the need for additional repeaters or combination equipment. This reduces DMR users' costs and simplifies their network deployment plans.
Mobile devices have long faced the problem of short battery life. Previously, a fully charged battery could only add limited talk time.
The advent of dual-slot TDMA has solved this problem. This is because each call only uses one of the time slots, so it only needs half the capacity of the transmitter, and the time slots are "swapped" for use. This reduces overall power consumption per call and increases usage time, extending charging intervals. Modern digital devices also include sleep and power management technologies, which further increase battery life.
With the above functions to improve power efficiency, users of DMR management equipment can create a more concise and environmentally friendly wireless communication network, and wireless communication itself can also benefit from longer battery life.