Choose the appropriate architecture
The DMR Association describes Tier II for conventional systems and Tier III for trunked systems. The standard uses two time slots in 12.5 kHz channels in the corresponding configurations. This feature does not remove the need to size traffic. The project should assess busy periods, priority groups and compatible equipment, avoiding confusion between the number of registered radios and the capacity for simultaneous calls.
Verify coverage in the field
Transmission power alone does not determine range. Terrain, structures, antenna positions, cables and noise influence the result. The design recommendation is to combine a technical survey with tests along actual user routes and record coverage gaps. Remote installations also need power, electrical protection and maintenance provisions. A well-positioned repeater can be more useful than increasing power without reviewing the installation or the antenna arrangement.
Program for actual operations
Talkgroups, channel names and button functions should be understandable to the team. Location, messaging and emergency functions depend on the terminal, infrastructure and configuration; they are not universal across every DMR radio. Interoperability between manufacturers needs validation for the required functions. After deployment, user tests, an inventory and programming backups help keep the system organized over time, especially when devices are replaced or users move between teams.
What to assess for your project
- Map users, talkgroups and expected traffic.
- Survey coverage at actual work locations.
- Verify compatibility of the required functions.
- Document programming, infrastructure and maintenance.
COM3
How COM3 can help
COM3 can help assess DMR radio communications, design repeater and antenna systems and specify digital radios for different activities. Deployment can include programming, coverage tests and operational integration, together with an assessment of the authorization requirements applicable to the project.
Topics in this article
Further reading and references
Technical sources consulted for the fundamentals of this content. Project recommendations are an editorial synthesis by COM3.