DMR is short for Digital Mobile Radio. It was originally developed by Motorola.

DMR has become more popular recently because of the ability to use repeaters or homemade hotspots to connect to nearly any talkgroup anywhere around the world.

DMR is a perfect application for large businesses over multiple sites. It allows the use of repeaters, which can connect users to any talkgroup. It was adopted by amateur radio, and since it was used commercially first, it has some unique quirks.

There are lots of acronyms in DMR. What are they and what do they mean?
Here is a short list of acronyms and terms unique to DMR
Codeplug: A codeplug is the settings you program into your radio. It has the memories of the repeaters and the talkgroups.
CPS: Customer Programming Software. This is the software you use to program your radio. It controls everything about your radio. Be prepared to get proficient at using it to program your radio.
Talkgroup: A talkgroup is like a chatroom that you can join via radio.
DMRID: A DMRID is a unique ID assigned to every DMR user. You can only use DMR if you have a DMRID. You can request one from here: https://radioid.net/
Time Slot (A or B): A time slot tells the radio when to transmit.
Color code: This is not a color, but think of it like CTCSS for talking to the repeater. Without the correct color code, the repeater will not accept your transmission.
Zones: A DMR Zone is like a folder. It helps keep your radio memories organized. It is suggested to use a zone for the talkgroups on a certain repeater.
Hoseline: This is a great resource to test your transmissions. You can also see which talkgroups are currently active with traffic.
Hotspot: This is a user-supplied device that connects to a DMR network so you can use your radio and hotspot to connect to any talkgroup without the need for a repeater.
DMR Network: A DMR network is a collection of talkgroups managed by an organization or group. There are several with different missions and philosophies: Brandmeister, DMR+, and TGIF.

How does DMR work?
DMR uses a digital voice encoder and decoder to

How is DMR compared to standard VHF/UHF FM?
DMR is
It has some advantages over other digital voice modes.
DMR is not specific to a brand.
DMR is cheaper because it is not brand-specific.

It also has some disadvantages
DMR is pretty difficult to set up.
The audio is not as good as other digital voice modes.

DMR allows 2 transmissions to be sent on the same frequency at the same time. For each repeater, there could be 2 different users at the same time.

The magic of DMR is the talkgroup. A talk group is like a chat room. Each repeater has a set of talkgroups, some of which may be networked to the internet. This means that many outside stations can connect to the same talkgroup and be broadcast over many repeaters.

There are several DMR networks to connect to. The number of different talkgroups available is massive!
The Brandmeister network breaks the talkgroups into country, region, and zones.

Here is a presentation on DMR that was given at Seapac in 2025.

https://docs.google.com/presentation/d/1VdxJ0jvZC8QyxC3IuOWz7s_03DSVJFOJcQpt8WAFEM8/edit?usp=sharing