Digital Mobile Radio (DMR)

  1. The Digital Mobile Radio Standard
  2. VK-DMR - The Australian Digital Network
  3. DMR Repeater Frequencies
  4. VK-DMR Network Bridges
  5. DMR Radio and Repeater ID's
  6. DMR Registration
  7. Dynamic Reflectors
  8. Connecting to DMRPlus
  9. Using Reflectors for DMRPlus on MMDVM Repeaters
  10. VK-DMR Talk Groups and Time Slots
  11. North America Talk Groups
  12. Setting Default Option Strings in DMRGateway
  13. Hotspots
  14. Simplex Contacts
  15. Misc
  16. Why do we have DMR-marc and Brandmiester Networks
  17. OpenBridge
  18. VK-DMR Net
  19. The Seven Digit Call Connection Service
  20. Proprietary - Internet Protocol Site Connect (IPSC)
  21. Open Source - Internet Protocol Site Connect (IPSC)
  22. DMRLink Project
  23. Analog_Bridge
  24. HBLink
  26. dmrconfig - a utility for programming dmr radios
  27. DMR Reference Sites

The Digital Mobile Radio Standard

DMR is an acronym for Digital Mobile Radio.

There are four opertional areas to DMR:

  1. User operator - usually with a hand held radio.
  2. Hotspot operator - a private low power interconnect to the intenet
  3. Repeater operator - An RF repeater station to provide coverage in a geographic area
  4. Network Operator - manage your own IPSC bridge (such as the c-Bridge™) or DMRGateway
    The network operator is server based and builds regional networks that
    interconnect to the other DMR networks.

The standard defines a two-slot TDMA channel access method thus allowing two simultaneous voice or data calls on a 12,5kHz radio channel. DMR was originally designed by ETSI for land mobile, commercial communications in the 66-960MHz band. This is evident in the user interface where numbers are used in lieu of call signs. DMR modulates with 4FSK, indicating that it uses 4 frequencies (compared to D-Star with 2 frequencies). This allows to double the data rate to 9600 bit/s. The higher rate allows the transmission of 2 channels at the same time (2 time slots). Be aware that you have to enter the talkgroup number into the receive group list of your radio too, or your squelch will not open. This is a common error made by first time users and it is very frustrating. ­

The standard is divided into four chapters:


The standard also refers to three tiers:


VK-DMR - The Australian Digital Network

The main website for Australian DMR: VK-DMR - The Australian DMR Network

VK-DMR Information

Ther is a very active Facebook group that is worthwhile Joining. It is a closed group but eay to join. They let me in!:


DMR Repeater Frequencies

DMR-Repeaters.html (local)


VK-DMR Network Bridges

Australia has two server, located in a Telstra data centre in Sydney, NSW, reportedly located in close proximity to each other.

Both of these are bridged to the IPSC_MASTER VK, bMaster+, IPSC2 server. (DG1HT DL5DI OE1KBC)

Use the following links to monitor the status of the two core servers responsible for linking all repeaters currently supporting the vk-dmr network.


DMR Radio and Repeater ID's

Note that the DMR ID database has moved to:

Use this site to lookup ID's for both users (seven digit) and repeaters (six digit):!

For example the VH4RDB repeater aqt Mt Cotton, Queensland has as ID of 505424:

DMR Registration

Image Registration

The goal of RadioID is to have a master listing so you can take a DMR radio anywhere in the world and it will work without ID conflicts. Amateurs are increasingly bridging digital networks so it is important that no two users have the same ID. - DMR Registration Page

The Motorola Amateur Radio Club Worldwide Network: - DMR-MARC

The Seven Digit Call Connection Service

"CCS" stands for "Call Connection Service". The system was developed a few years ago as an optimization of the "G2 Callsign Routing", which uses the Icom DSTAR systems for the targeted establishment of connections to a specific call partner, and also to extend the call-sign routing to self-built repeaters, hotspots and private modems in one open network.

The first 3 digits of the IDentifier follows the Mobile Country Code numbering as defined in the ITU-T Recommendation E.212. This first 3 digits of the ID you are entering in your DMR radio are therefore identifying your geographical origin :

Further information about the ITU-MCC can be found eg at
Wikipedia and at the ITU

The numbering system is constructed hierarchically, the first digit represents the continent, (2 = Europe, 3 = North America, 4 = Asia, 5 = Australia / Oceania, Africa 6 = 7 = South America). The first 3 digits characterize the country, eg 505 stands for Australia, 232 for Austria, 262 for Germany. After the MCC, amateur radio DMR networks append a 4-digit code for users and a 3-digit code for repeaters.

DMR-MARC Admin info about your user ID:
ID: 5054273
Callsign: VK4PK
Name: Glenn
City: Russell Island
State: Queensland
Country: Australia
Remarks: DMR
RadioID maintains user, repeater and various other datbases. They can be downloaded here:!


Dynamic Reflectors

Talk Group 9, Time Slot 2 has a special use.

TG9-2 is used to dynamically select a specific reflectors. This provides access to the DMRPlus network of reflectors. A list of reflectors may be found at

TG9 on TS1 is local to an individual repeater. TG9 on TS2 is used to link an individual repeater to a reflector. In both situations, you would likely not hear anything unless you happened to be listening to that repeater.

To access reflectors, the radio must also be programmed with the TGs you are attempting to access

TG5000 checks your local repeater status. You then use the reflector number you wish to connect to as the tx TG – i.e. TG4400 for ref 4400.

Once you have connected, use TG9 to communicate via the reflector. TG4000 is used to disconnect your repeater from the reflector, or you can just let the reflector time out. Timeouts are normally set from 10 to 15 minutes after the last communication on that talkgroup.

Description Reflector   TS  Talk Group  DMR     DMR+
WWE         4629        2   TG91
                        2   TG9
VK-DMR      84800       2   TG8         505     4800
VK-DMR      84801       2   TG8         3801    4801

UNLINK      84000   

UK Call     4400        2   TG2300
UK Chat     4401        2   TG2351
UK Chat     4402        2   TG2352

?????       9900        2   TG9990
BM AUST                 2   TG13
JA???                   2   TG53099


Connecting to DMRPlus



Using Reflectors for DMRPlus on MMDVM Repeaters

As with MMDVM hotspots, When using MMDVM repeaters to connect to DMR Plus talkgroups, use TG8. Then to change reflectors, enter the Private Call reflector code and transmit for a few seconds. An announcement through the DMR Gateway will confirm the active reflector.

As a convenience, you can programm teh codeplug the keypad fast dial keys as follows:


VK-DMR Talk Groups and Time Slots

TG TG Number Time Slot Destination
TG 1 WW 1 1 World Wide Calling
TG VK Nets 5 1 VK Nets Broadcast TG
TG 8 Cluster Linked 8 1 Local Cluster of Repeaters connected
TG 8 Not Used 8 2 Not Used
TG 9 Local 9 1 Local Repeater Stand Alone
TG 9 9 2 DMR+ Refelctor Connections
TG 13 WWE 13 1 World Wide English
TG 113 113 1 User Defined TG
TG 123 123 1 User Defined TG
TG 133 USA 133 1 DMR+ Connection USA
TG 143 UK 143 1 DMR+ Connection UK
TG 153 SP 153 1 DMR+ Connection South Pacific
TG 505 VK 505 2 VK All Repeaters
TG 3800 3800 2 DMR+ VK All Repeaters
VK5 3805 2 DMR+ State Located Repeaters
VK6 3806 2 DMR+ State Located Repeaters
VK7 3807 2 DMR+ State Located Repeaters
VK8 3808 2 DMR+ State Located Repeaters
VK9 3809 2 DMR+ State Located Repeaters
439.200 MHz 99 TS Not Used VK Simplex Digital Calling Frequency

Source: VK_DMR-January-2018_Talk_Groups.pdf


TG505 is the national channel - it keys EVERY VK repeater
TG9 on slot 1 can be used to work another station on your local repeater only.

TG8 keys repeaters in defined groups.
This TG is programmed for each repeater and can not be changed by users. The TG8 groups are as follows:


TG8 Group Repeaters linked
Perth All Perth
Melbourne and Vic. All VK3
Sydney and Orange All Sydney and Orange
Sth NSW High Range and Goulburn
Tasmania Hobart and Launceston
SE Queensland All SE Qld
ACT Canberra
FNQ Cairns and Atherton


North America Talk Groups

This table shows the North America DMR Talk Groups as defined by DMR-MARC Motorola Amateur Radio Culb) and their mapping to DMRPlus Reflectors. The DMRPlus reflector numbering system is an Open convention agreed upon by various interest groups.

Talkgroup Name
13114581DMR+ Quebec (French)
13314639DMR+ USA (English)
13414380DMR+ Latin America (Spanish)
14314404DMR+ United Kingdom (English)
15314851DMR+ South Pacific (English)
316914640Midwest Regional
317214642Northeast Regional
317314643MidAtlantic Regional
317414644Southeast Regional
317514645Southern Plains Regional
317614646Southwest Regional
317714647Mountain Regional
302014590Newfoundland/PEI Provincial
302114591Nova Scotia Provincial
302214592Quebec Provincial
302314593Ontario Provincial
302414594Manitoba Provincial
302514595Saskatechewan Provincial
302614596Alberta Provincial
302714597British Columbia Provincial
302914599New Brunswick Provincial



Setting Default Option Strings in DMRGateway

Examples of option stringsin the Options box on the configuration page: in the Options box on the configuration page.




The VK DMR network supports hotspots.

Settings to join the VK-DMR+ Master server for connections into the VK-DMR Network:

Dongles/openspot/dv4min 143/153 haven't worked for a while unfortunately. You can use TG9 on slot 2 to connect to any DMR+ reflector.i etc:
• Server:
• Port: 8880

• Server:
• Port: 55555

DMR+ reflectors are mapped to VK-DMR talk groups as described in the table below.

Note that DMR+ reflector 4800 keys TG505 which is every VK DMR repeater.
Hotspots can experience network latency due to the nature of the internet connection. 
DMR+ reflector VK DMR TG
4800 505 – VK wide
4801 3801 VK1 ACT
4802 3802 VK2 NSW
4803 3803 VK3 VICTORIA
4804 3804 VK4 QUEENSLAND
4807 3807 VK7 TASMANIA
4808 3808 slot 2 user activated chat channel
4809 3809 slot 1 user activated chat channel

Simplex Contacts

Simplex Frequency: 439.200MHz (The Digital Voice Calling Frequency)
Use TG99/TS1.



Some information on our VK-DMR TG's. TG 113, 123 are User defined and this means you have to switch to this channel and Press your PTT for 1 secondand this will switch the repeater you are using into User mode and your mate orother person you was talkingto needs to do the same and both of you will be connectedand not tie up all otherrepeaters in the Network. TG 133 connects you to the USA Gateway ONLY, and it is the same for TG 143 to the UK Gateway and 153 to the South Pacific Gateway. 10 Minutes from the last PTT.


 143/153 haven't worked for a while unfortunately. You can use TG9 on slot 2 to connect to any DMR+ reflector.

The IPSC2 bridge cant handle the IP latency to the North American servers that
support DMR MARC; while it connects and will pass some traffic, it subsequently 
fails when it tests the connection. 
We are currently exploring options to work around the issue. 
. Joe Nevin VK6ZTN
Like · Reply · 4d
Adam Anderson
Adam Anderson Why not go back to dmr Marc
Like · Reply · 4d · Edited
Matt Perkins
Matt Perkins Hi joe where is the IPSC2 bridge located. It looks like Perth on the panel but hope it’s really in Sydney where the closest path to the US is

Like · Reply · 4d
Joe Nevin
Joe Nevin To revert to the old configuration would require replacement of the cBridge, and would result in loss of reflector and dongle access, plus a number of other features of the current network. That being noted, we are working on a hack to see if we can sort it out.

The IPSC2 & DMR+ bridges are located in the Sydney AWS data centre.


Why do we have DMR-marc and Brandmiester Networks

Ben Fergus Goes back quite a way. As far as I know the first amateur DMR network was DMR-Marc.

They started off Motorola only. Hence the name DMR- Motorola Amateur Radio Club.

They were very hostile originally to anything not Motorola. Very much against the general amateur ethos having a closed in system but at the time it was what it was.

Then along came DMR+ which allowed non Motorola repeaters. Hytera and then hotspots etc. It was more the network for experementing in the early days. However at the time you still only had commercial repeaters available so really it was still limited.

At some point DMR-Marc started to allow Hytera repeaters on the network but that was still only 2 commercial choices.

Then the major change was when MMDVM came along. It opened up the option of building a completely home brew repeater.

Around the same time along came Brandmeister and that gave a good network to run our new MMDVM repeaters.

The ethos of Brandmeister is in the name. A complete mix of brands and protocols on a completely open network and giving control to the repeater owners instead of all control being held by the network runners.

For quite a while DMR-Marc ignored Brandmeister and kept their closed ethos. But over time they kept loosing more and more repeaters and users to Brandmeister. Brandmeister grew at a huge rate simply because repeater owners wanted choice that DMR-Marc would not give them. A good percentage of repeaters were new MMDVM repeaters and another good percentage were repeaters poached from Marc.

At some point VK-DMR forked away from DMR-Marc and I have seen a huge change in their ethos for the better since the split with a much more open network giving users much more choice.

I didn't think much of the VK-DMR network before the changes but since their change in ethos they have made some big changes which I respect.

This is an exciting time in digital radio with more choice than ever and do many avenues to learn and play with.

I have only concentrated on the main networks you will hear about, and it is a limited summary as I typing this on my phone while in a waiting room so I have left a lot out. But hopefully it gives you a bit of an idea of some of the history as I am aware of things.



OpenBridge is an open protocol to link DMR servers. Protocol designed in cooperation between BrandMeister team and Kurt OE1KBC. OpenBridge is very simple protocol that allows to send call streams between servers. Protocol is based on MMDVM protocol and supports DMRD packets only.



The VK-DMR net is on at 1930 hours EST Tuesday nights on TG3809, TS1.
The cordinator is Peter Fauth VK4NBL


Proprietary - Internet Protocol Site Connect (IPSC)

IP Site Connect (IPSC) is a vendor specific repeater feature offered by some manufacturers. Note that MototrboTM repeaters will only interconnect over the Internet with other MototrboTM repeaters because it is not part of the ETSI specifications and the manufacturers don’t want to interconnect their infrastructures. Motorola Solutions MototrboTM IPSC implementation allows up to 15 MototrboTM repeaters operating in DMR mode to be connected on a fully meshed IP network, with one of the repeaters (or a c-BridgeTM) serving as a Master and all of the others as Peers. Any traffic originating on one of the interconnected repeaters is relayed over the IP network to each of the other repeaters. The Peers will first establish a connection with the Master and obtain the database of the other Peers along with their IP and port addresses.

The more repeaters in this fully meshed IPSC network, the more IP network bandwidth required for each repeater. A single Peer connected to a Master requires 15 kbps for each time slot participating in the IPSC network, 6 kbps for link management, and 55 kbps for RDAC (Remote Diagnostics and Control) traffic; if both time slots are participating in IPSC, 91 kbps bandwidth is required; each additional Peer requires 36 kbps bandwidth. The Master requires an additional 3 kbps bandwidth for each Peer in the network. The MototrboTM System Planner has full details about calculating necessary bandwidth for repeater operators. To expand beyond the limits of basic IPSC network requires the utilization of a bridge to interconnect the different IPSC networks. Rayfield Communications c-Bridge TM [] is the current preference in North America. In the European market, SmartPTT [] is common. BridgeCom Systems MV-IPSCTM [] is also compatible with the c-BridgeTM as both are products of RavenNet. These bridges require static IP addresses and larger IP network bandwidths than individual repeaters.

The c-Bridge TM supports individual managers for each repeater (micro- segmentation), which is an improvement over having the c-Bridge TM manager connected to a network of repeaters; this gives the ability to reduce bandwidth requirements and customize Talk Group availability for individual repeaters. The c-BridgeTM manager can serve as either a Master or Peer on an IPSC network. The c-Bridge TM allows for network connections to other IPSC networks, and other c-BridgesTM utilizing Control Center (CC) connections. The c- BridgeTM allows for the management of Talk Groups on an always-on, scheduled, or on-demand (PTT) basis. Models (upgradeable) are available to support 5, 15, 30, and 50 repeaters and they also support 100 CC connections between c-BridgesTM.

The c-BridgeTM also supports the interconnection of non-DMR audio sources utilizing an optional USB analog dongle and vocoder module. Remember, someone is paying for all of the infrastructure and monthly operating costs. If a club is operating your local DMR repeater, join and support the operation. If an individual is operating the local repeater, donate to support his ongoing expenses. Repeater operators should also be supporting their bridge operators. Besides the cost of the infrastructure equipment, there are also recurring monthly expenses for rent, utilities (power and Internet), insurance, and maintenance.

Source: - By John S. Burningham, W2XAB February 2015


Open Source - Internet Protocol Site Connect (IPSC)

This application is now superseded by the DMRGateway application. Details of the DMRGateway project can be found here:
DMRGateway.html (Local)
DMRplus IPSC protocol Specs for homebrew DMR repeater by DL5DI,G4KLX,DG1HT 2015

The specification for IPSC for the Home Brew DMR Repeater was initial written by DL5DI and was based on specifications from Jonathan Naylor G4KLX for the repeater side. Torsten Schultze DG1HT added requirements, and Hans-J. Barthen DL5DI added requirements for the network/reflector side.

A copy of the specification is found here: DMRplus_IPSC_Protocol_for_HB_repeater.pdf (Local)


The DMRLink - Motorola MotoTRBO IPSC Client project repository:, Thia is an open Source IPSC Client. It details building an open-source
IPSC "stack", troubleshooting IPSC performance issues, and as a basis to easily
write applications such as logging, bridging, etc.



Steve Zingman, N4IRS, Analog_Bridge Repository:

The purpose of analog bridge is to encode and decode PCM (analog audio) to AMBE for use with and


Cortney T. Buffington, N0MJS, HBLink respository can be found here:

Thanks to the work of Jonathan Naylor, G4KLX; Hans Barthen, DL5DI; Torsten Shultze, DG1HT we have an open protocol for internetworking DMR repeaters. Unfortunately, there's no generic client and/or master stacks. This project is to build an open-source, python-based implementation. This is a non-commercial license. Atribution is required if you use it.

For those who will ask: This is a piece of software that implements an open-source, amateur radio networking protocol. It is not a network. It is not indended to be a network. It is not intended to replace or circumvent a network. People do those things, code doesn't.

This work represents the author's interpretation of the HomeBrew Repeater Protocol, based on the 2015-07-26 documents from DMRplus, "IPSC Protocol Specs for homebrew DMR repeater" as written by Jonathan Naylor, G4KLX; Hans Barthen, DL5DI; Torsten Shultze, DG1HT.


Outside Motorola MOTOTRBO is known as DMR. See the article What is MOTOTRBO? at:


dmrconfig - a utility for programming dmr radios

DMRconfig is a utility for programming digital radios via USB programming cable. Supported radios:


DMR Reference Sites

Web Sites:

VK-DMR Newsletters:
No 1. VK & ZL DMR Network Newsletter September 2015
No 2. VK & ZL DMR Network Newsletter October 2015
No 3. VK & ZL DMR Network, Newsletter December 2015
No 4. VK DMR Network Newsletter July 2016, Issue 4, July 2016
VK-DMR Talk Groups Added Jan 2017 (Local Cache)
No 8. VK-DMR Newsletter, Issue 8, April 2018


Facebook Groups:
The VK DMR Network - Closed Group
DMR For Dummies - D4D - Closed Group


Glenn Lyons VK4PK
Ver:gnl20190313 - pre published v0.9