DEFINITIONS OF DMR TERMS
Talk group is a method of grouping or assembling multiple users (Radio ID’s) to a single contact. Static Talk group is permanently activated on a particular time slot by the repeater sysop. This type of static assignment passes ALL traffic from the DMR network over the air on the time slot it is assigned to. In simple terms, this networks many repeaters together full-time for that particular talk group. Dynamic talk group assignments are used for temporary activation on a time slot on a particular repeater. This type of talk group functions for a set amount of time AFTER a local repeater user activates it by transmitting on a repeater using that talk group in their radio. When the timer expires and no local user has keyed up again for a set amount of time… the time slot and the talk group and release and the repeater is again open only to the talk groups that remain static.
Channel contain the information required to connect to the repeater and select the talk group. Each channel is programmed with the Channel Name, Frequencies, and Talk groups.
Zone is a way of organizing a collection of channels. You can organize zones however you like in your code plug. You can think of them as file folders, and many people organize the zones based on location. The following list is an example of zones that are set up by location:
- Zone 1 – Local DMR Repeater
- Zone 2 – Local DMR Repeater to the East
- Zone 3 – Hotspot
- Zone 4 – Nearby DMR Repeater to the North
- Zone 5 – Nearby DMR Repeater to the South
- Zone 5 – Local Analog Repeaters
Color Code: DMR repeaters use Color Codes (CC) much like analog repeaters use CTCSS (PL) or DCS. To access a repeater you must program your radio to use the same CC as the repeater. There are 16 different CCs (CC0-CC15).
• The use of Color Codes is not optional on DMR systems. If your Color Code is not set correctly, you will not be able to access the repeater. The purpose of using different Color Codes is when multiple repeaters are operating on the same frequency and have overlapping coverage areas.
Time Slot: A repeater can support two simultaneous conversations by alternating between two time slots. About 30ms is given to time slot 1, then the transmitter flips to time slot 2 for 30ms, then back to time slot 1, and then to time slot 2. Since you transmit on just one time slot, your radio’s battery lasts longer as it is really only transmitting about half the time you have the PTT keyed. In other words, the repeater’s time is divided so that two different groups of Hams can have access simultaneously via a process known as “Time Division Multiple Access” (TDMA).
Code Plug is a relatively small binary file that’s managed by software a program on your computer and transferred to or from the radio via several proprietary means. It contains the operating frequencies, tone selections, timeout values, system IDs, etc. In some instances, there’s even some parts of the program itself in the code plug which defines a radio’s personality.
