The three digital voice modes which are currently most commonly used in amateur radio are:
- D-STAR -- Digital Smart Technologies For Amateur Radio
- DMR -- Digital Mobile Radio
- C4FM -- Yaesu Fusion
In general, the digital voice modes may be accessed using a radio capable of encoding/decoding the various formats. You can connect to the required Internet resources in a number of ways, but when utilizing a radio, this is usually accomplished by using repeaters or hotspots.
A hotspot is essentially a micro-repeater. That is, it contains a low-power transceiver which is connected by some means to The Internet.
Some hotspots work with your computer, while others are self-contained, usually utilizing a Raspberry Pi.
Without a radio, you can utilize a PC with a dongle or an app. You can also use an app which runs on an Android phone.
To support long distance communications, all of the digital voice modes employ Internet Linking. The three modes discussed here do this in somewhat different ways.
One common technology utilized by all of the modes discussed here is the reflector. A reflector is a server connected to The Internet. It enables repeaters, hotspots and dongles to communicate in a shared environment, much like the old Party Line concept used in early telephone systems.
When one station transmits into the system, everyone else connected to that reflector receives the transmission.
There are different designations for the reflector types used with the various digital modes. These will be briefly described as part of the introduction which follows.
D-STAR is a mature protocol, originally devised and implemented by the Japan Amateur Radio League (JARL) in 1999.
The first full implementation was released in 2001. Over the years, new features and improvements have been incorporated into the protocol.
This digital mode was designed by and for Amateur Radio. Radio operators are identified using their amateur radio callsign.
D-STAR utilizes four types of reflectors. Each type consists of three letters, followed by three numbers, then followed by a port (single letter).
The DCS reflectors are newer and have "rooms" rather than ports and can use letters A-Z
(allowing 26 rooms).
The other reflector types generally use ports A through D.
The REF reflectors are the first generation but still widely used in English-speaking countries.
The XRF reflectors are the second generation and less used, but remain active.
The XLX reflectors are multimode reflectors, which support bridging communications across the various modes. This makes it possible for a station using D-STAR, for example, to converse with another station operating DMR, Fusion or even analog (FM).
Access to The Gateway requires a one-time registration of your callsign. Gateway access is required if you want to connect to reflectors and take advantage of worldwide access. Registration links are provided on this page.
Your callsign is also a crucial piece of information which must be programmed into your radio. There can be three other pieces of information which combine to facilitate the connection between your station and the rest of the world. These are the RPT1, RPT2 and URCALL fields.
In particular, When you connect through repeaters and some hotspots, the RPT1 and RPT2 fields provide the path between your radio and the repeater and the connection between the repeater and The Gateway, respectively.
The URCALL field is an 8-character field which specifies actions and associated data such as the name of a reflector and a request to link to it. The eighth (right-most) position of the URCALL field is the action character. For additional detail, read through my Practical D-STAR presentation listed in the Resources section of this page.
There are numerous reflectors available, located throughout the world. Refer to the reflector lists for details. As of this writing, two very popular English-speaking reflectors are REF030C located in Georgia, USA, and REF001C located in London.
DMR had its beginnings in the commercial sector. It has always been the most rigid of the three modes discussed here, however, with the introduction of BrandMeister, it has become more flexible and friendly
The three major networks utilized in DMR are Brandmeister, D-Plus and DMR-Marc.
Worldwide connections are made through TalkGroups. Each is assigned a numeric value. Some are regional, while others are more functionally divided.
DMR utilizes a two timeslot implementation. Time periods are divided. For a given interval of time, half of the time is given to timeslot1 and the other goes to timeslot2, with a small amount of time between the slots used for switching between them. This allows for two conversations to occur concurrently.
Programming is more complicated in DMR than other modes. The configuration, consisting of channels, zones, talkgroups, timeslots and destinations is packaged into something called a CodePlug. This is really nothing more than a collection of radio settings and channel data.
I have included two codeplugs on this page which can be used with the MD-380 and MD-390 radios. I have removed personal data from them. You may use them as a starting point for creating your own zones. Most states and regions also offer codeplugs containing zones pertinent to their area.
Being commercially oriented, DMR identifies each radio operator using a Subscriber ID rather than an amateur callsign. You must register to be assigned your CCS7 number. Refer to the links on this page for additional information.
Although there are many talkgroups available, one of the very active groups is TAC310. There is also a worldwide (WW) group and a North America (NA) talkgroup.
C4FM Fusion is the Yaesu proprietary digital implementation. Like D-Star it was specifically designed for Amateur Radio.
It is very easy to set up, especially for reflector operation. Its limitation is that only Yaesu radios are able to offer this digital mode.
The reflectors are designated by FCS followed by a three-digit number, i.e. FCS001, FCS002, FCS003. Each of these major groups contains 100 rooms numbered 00 to 99. A popular reflector is the America-Link reflector and it can be accessed using FCS190, FCS290 and FCS390.
There is another group of C4FM reflectors called YSF reflectors. These have names and numbers which uniquely identify them. You can find listings for all of the reflector types on-line and they are also shown in the programs associated with many hotspots.
There is also a WiresX mode of operation in Yaesu Fusion. It enables you to set up a node of your own. Thus far, I haven't explored this type of operation. To the best of my knowledge, hotspots can access FCS and YSF reflectors, but only Yaesu equipment can operate on the WiresX network.
Following is a list of links to tutorials, reviews, downloads, reflector lists and other resources related to the digital modes discussed on this page.