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Digital mobile radio (dmrfordummies.com)
59 points by teleforce on Dec 4, 2022 | hide | past | favorite | 15 comments




It sure would be nice if someone that wasn't a geek about this subject could rewrite this article in a way that someone that isn't well versed in this subject could understand what this was. That opening paragraph was a struggle just to read. That, or my reading comprehension skills are deteriorating.


It's not you. That is one terribly written article. It's even called out by wikipedia for the lack of sources. Can't understand why someone posted it to YC.

DMR is a mobile radio standard. Think of a private network of walkie-talkies, vehicle-mounted and desk mounted radios connecting professional users. Let me know if I can find a better resource for you.


>Can't understand why someone posted it to YC.

I mean, we are talking about it now. It is an interesting topic. It's just very poorly written. Maybe this attention will help fix that?

From what I've been able to understand, this just means that you can buy a radio from vendor A, and I can buy one from vendor B. As long as they both claim to be part of the DMR standard, then both radios should be able to communicate with each other. Since it's digital, I'm assuming the standard describes the word length and other various aspects so that anyone can decode/encode the proper AD/DA.

But man, why couldn't they just say that?


It's wikipedia so I changed it for ya. The first sentence now says "Digital mobile radio (DMR) is a specification for commercial products so they can interoperate."


and who are you that the Wikipedia gods are not just going to revert your changes? the mods of wikipedia are not my favorite group of peeps. i have little faith in them. so, just because you, some random-to-me person on the internet makes a legit edit does not mean that a mod with an agenda won't come along and put it back


"Maybe this attention will help fix that?"

Fair enough and it sounds like it has. Maybe in future the YC title can be prefixed with something like 'Call to assist: ', for the benefit of those less inclined to edit such articles.


Yeah, the way it's written now they might as well just redirect the page to RadioReference Wiki[0], because this is useless for someone not already familiar with tons of radio technology...

[0] https://wiki.radioreference.com/index.php/DMR


The problem is that the ONLY people playing in the DMR space are mega-geeks about it, who care about building a beautiful perfect system and not at all about it's usability by actual people, nor about if it's good for ham radio or not.

DMR is essentially a commercial radio network, being run on amateur radio frequencies. This type of radio network is not designed to be understood by the user, it is designed so that the user can be handed a radio with a channel-select dial on the top and told "go to channel 3", and never think about how the radio works other than press-PTT-before-you-start-speaking.

Because so very little of it is actually user-controllable, many HAMs would just as soon never touch it. There's very little "amateur" in it at all, except for amateur network admins who think it's fun to have some gear on the top of a mountain.

In case you haven't deduced it yet, in my personal opinion: DMR is a blight on HAM radio. If you want a motorola trunked radio network, buy a motorola trunked radio network.


Let's see how ChatGPT (https://chat.openai.com/chat) does this!

My prompt was the following (I'm unclear how much it helps to include a URL): "Explain Digital Mobile Radio in simple sentences. You can use https://en.wikipedia.org/wiki/Digital_mobile_radio as a reference."

Its response:

Digital Mobile Radio (DMR) is a type of digital radio technology that is used for two-way radio communications. It allows for the transmission of voice and data over a radio signal using digital techniques. DMR is used in professional mobile radio and amateur radio applications, and it offers improved audio quality, better resistance to interference, and enhanced features compared to analog radio systems. DMR networks are typically set up by professional organizations, such as businesses, government agencies, and public safety organizations, to provide communication services for their employees or members.

I also asked it to rewrite the pasted opening paragraphs from the Wikipedia page "in simple terms so that someone who isn't well-versed in the subject can understand what it is" and it responded with this:

Digital mobile radio (DMR) is a type of radio technology used for commercial products. It is defined by a standard created by the European Telecommunications Standards Institute, and is designed to be low-cost and easy to use. It is used in competition with similar technologies like P25 phase II and NXDN. DMR has three different tiers, and was first published in 2005. The main goal of the technology is to allow radio communications to be used across different brands without being limited to one specific brand.


This reads quite clearly too me. Is this description lacking?


It's a digital radio (meaning, voice is transformed to ones and zeros, before the signal is put on the air) using TDM to make it possible for two simultanious conversations to happen at the same time in the same place (by splitting the "time" into chunks - timeslots, so you get a few milliseconds to transmit and receive, and then you stay quiet and the other users using the other timeslot get to transmit and receive).

It also adds some nice features such as groups and group calling, and since it's digital it's easy to route the data around and build cheap repeaters.

It's used mostly by commercial services and ham radio operators.



Yeah this is a much better introduction to the big deals in DMR.

If any of you folks want something that uses a free codec instead of DVSI's proprietary AMBE2, there's the M17 project[1] that uses the free open source codec2 voice codec.

There's also the Opulent voice project[2], which in turn uses Opus, but it does not fit as narrow channels as M17 or DMR does.

1. https://m17project.org/ 2. https://www.openresearch.institute/2022/07/30/opulent-voice-...


Thanks! A mod changed to that from https://en.m.wikipedia.org/wiki/Digital_mobile_radio in response to your comment.




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