# Talk Group Operation

As mentioned in introPrivateCalls, DMR aims at being repeater transparent. That is, it does not matter which repeater is used for the operation. This is also true for talk groups. In this section, I'll continue with the example of an OM at his holiday location, who wants to participate in his afternoon net. For example, the afternoon net is happening on the talk group 2621 (Berlin/Brandenbug, BB). This talk group is usually statically subscribed on all repeaters in the states Berlin and Brandenbug. That means that the local afternoon net can be performed in this talk group without any additional action in this area. (see figIntroTG top image).

## Talk group operation between countries

For the OM at his holiday location, this it not true. An Italian repeater will certainly not subscribe the BB talk group statically. Therefore, the OM at the holiday location will not hear his afternoon net. He knows, however, when this net starts. So he can perform a group call to the that TG shortly before the net starts (see figIntroTG second image). This will subscribe the BB talk group temporarily at the holiday repeater (I0ABC). Now, the OM can hear and participate in the afternoon net. The subscription will be renewed whenever he starts a group call to that TG.

Once the OM subscribed the TG to the holiday repeater, he can participate normally at his afternoon net. All other participants will not even notice that he is not in the area and is participating from an italien repeater.

Name | Talk group number
Global | 91
Europe | 92
Germany | 262
Mecklenburg-Vorpommern & Sachsen-Anhalt | 2620
Berlin & Brandenburg | 2621
Hamburg & Schleswig-Holstein | 2622
Niedersachsen & Bremen | 2623
Nordrhein-Westfalen | 2624
Rheinland-Pfalz & Saarland | 2625
Hessen | 2626
Baden-Württemberg | 2627
Bayern | 2628
Sachsen & Thüringen | 2629

## Some talk groups

In contrast to the regional talk group TG8, all other talk groups are reachable from everywhere in the DMR network. This means, that the OM at his holiday location can easily participate in his afternoon net from everywhere as described above.

If the net, however, is happening in the regional TG8, the OM at his holiday location cannot participate. This talk group is only reachable from within the region. If the OM starts a call to TG8, he would only reach the region in italy and not the region at home.

For this reason, some regional clusters of repeaters are linked to a so-called Cluster. These clusters provide normal talk groups for the repeater within a region. These clusters are then also reachable from the outside. A list of regional clusters and their associated talk group numbers can be obtained under bm262.de/cluster/.