DStar versus DMR

Recently I have noticed a few people promoting DMR as the DStar replacement. So I have been looking into DMR a bit. Some of you may have read about Mototrbo which is Motorola's marking name for the DMR technology.

I intend to do a more in-depth comparison here between the various digital technologies. Not just DStar versus DMR, but also look at whatever Yaesu is coming out with, APCO25 and Nexedge/NXDN.

So I signed up on Yahoo Groups with a few of the DMR and Mototrbo groups. Via radio reference website, there even is a link to listen to one of the DMR networks/repeaters.

One of the first questions I asked on the groups, "can you build you own DMR/Mototrbo repeaters?" In other words, is it practical?

The answer I got was basically "no" that it is not practical and they way to get a repeater is to "get some of my friends together to share the cost." Also, not practical.

Now with DStar you can build a repeater yourself very easily. You need two transceivers with packet ports capable of supporting 9600 baud packet, a hotspot board and a computer. So here is what it cost to build a home-brew DStar repeater that a couple of folks in a local radio club are considering building.

Two single band Alinco radios. $279 each. Moencomm GMSK Node Adapter (hotspot board) at $120 and a computer, in this case a Raspberry Pi with Ethernet Adapter ($35 for the RPi and $30 for the Ethernet adapter. Total cost of the DStar repeater is $743 using all new equipment except for the duplexers and antenna which the club already has for the old UHF FM repeater days.

DMR well for a new repeater, since there are not a lot of used repeaters, about $3,000.

The other issue I see as a problem is with DMR each radio has an ID that has to be registered and is tied to the callsign of the user. This appears to be a real issue with sharing equipment and callsign routing, that is not an issue with DStar.

Also DMR programming is very complex. Mainly because DMR was meant for the commercial market. There are things that need to be programmed like "talkgroups" which do not exist in ham radio. If I read correctly, since all repeaters in a network are tied together, all transmissions go out over the entire network. There seems to be no way for an amateur operator to connect and disconnect the repeater to the network or network of choice. This is all easily done in DStar.

So here is what it really comes down to. DMR was designed for the commercial user in mind. DStar was designed for amateur radio. One fits better than the other. Both are open protocols except for the Codec which in both cases is proprietary. Both sound equally good.

DStar has over 1,000 repeaters world-wide. DMR less than 100. DStar has thousands of users world-wide while DMR has about 300.

DStar current generation radios can be used without any programming except for entering in the callsign of the user. DMR has to be programmed.

Clearly, DStar is way ahead. The question among many is will it remain there. DStar users say yes and DMR users say no. It's the 21st Century version of the code/no-code argument all over again.
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