FreeDMR Explained

  1. The FreeDMR Network
  2. How to Find your way around the FreeDMR Network
  3. Social Media
  4. FreeDMR News from the WIA
  5. Australian Servers
  6. The meaning of the Option String


The FreeDMR Network

The FreeDMR Network consists of three major components:
  1. A DMR capable Radio communicates with
  2. A Repeater or a Hotspot communicates with
  3. A Network Server that manages all the repeaters and connects their Audio according to Talk Groups.
RT3s.png Repeater.png hotspot.png-2 Server-multiple.png

The FreeDMR Network is a group of independent servers running the FreeDMR Server Software. The FreeDMR Servers are connected via OpenBridge (OPB) in a Mesh topology to one another to redundantly and diversely share all available TalkGroups among all Servers.

FreeDMR does NOT utilize a Master/Slave topology. All FreeDMR servers are seen as equal peers to each other just as all the individuals who run the servers are. No single person controls when where, what how or who can use FreeDMR. Free means free as in speech.

If you are having difficulty with one server, you can move your repeater (if you are a Administrator) or hotspot to another server. The is no such freedom with Master/Slave type networks that are controlled by one central server and it's Administrator(s) has all the control.

Here is a current listing of all Servers:


How to Find your way around the FreeDMR Network

Here is a listing of all the FreeDMR Servers:

The servers connect all the repeaters and hotspots that have connected to them to each other. On a hotspot you select a Server by selecting it in your configuration usually in the DMR Master dropdown box in Pi-Star. On a repeater the server is selected by the administrator.

Who gets relayed to who is determined by selecting a Talk Group (TG) and one of the two Time Slots (TS) available. TG on TS can be re-directed to othet TG's and TS by Re-Write rules configured into the repeater or Hotspot. To further complicate this Gateways allow for different TG to connect to other modes, For example Yaesu System Fusion, P25, D-Star, NXDN, M17, and even FM. Because audio can be encoded by different methods, Gateway connection often involve transcoding.

We also have to understand Static compared with User Activated modes. Hotspots and repeaters can be configured with selected TG to be static. In this case they listen to all traffic all the time and are available to transmit on all the time. You will aslo be able to transmitt straight off. User Activated in the other hand, require you, as the name suggests, activate the Talk Group. That is bring it online, by transmitting to the TG for a few seconds and then stopping for a second before again transmitting with your message. The process is often refered to by the onomatopoeia, "kerchunking. User activation provides for improved network efficiency when a network is busy.

There is much more to understand about Digital Voice communications. For example, we have not discussed the various timers involved, group TG and private TG, and Receive Groups, Monitor Mode which is sometimes called Promiscuous Mode.


Social Media


FreeDMR News from the WIA


VK2WAY Jared Quinn.

"Digital voice fans - The FreeDMR network is back in VK-land with a new master server, hosted in a Sydney cloud data centre and managed by VK2WAY.

FreeDMR is a global DMR Network for Amateur radio users around the worldHeading< and since its inception in November 2020 has grown to over 60 networked OpenBridge servers, over 700 talk groups and over 5000 regular users.

FreeDMR promises freedom for Repeater, Gateway Keepers and even some Hotspots to have full control, instead of being told what has to go where and when or what links to what.

FreeDMR offers features over other DMR networks includinp>g:

Hotspots are welcome to connect anytime by finding FreeDMR Australia in the Pi-Star DMR Network list or following the instructions on the FreeDMR website. Repeater and OpenBridge connection enquiries are welcome and can be made directly to VK2WAY or via the FreeDMR Australia Facebook page or Contact FreeDMR link on the FreeDMR UK website -

VK2WAY Sydney, Australia (Grid: QF56oc)
e: w:
m: +61 434 624465 ph.: +61 2 8000 8822 hamshack: 33 000 000 30


Australian Servers

ServerIDServer AddressIP AddressPortComment


The meaning of the Option String

For Example:

Glenn Lyons VK4PK
Ver:gnl2020119 - pre published v1.0