what is DMR radio

Simply put, Digital Mobile Radio has beaten analog systems with its upgraded yet simplified the process of radio communication. Ever since its invention, DMR has revolutionized communication in various businesses and industries.

Even while operating the most basic equipment, you get features like quality audio output and better coverage. Other benefits include longer battery life, improved security, and an overall enhanced user experience!

Most importantly, DMR users get to benefit from data capabilities like GPS, text messaging, radio programming, and much more! Let’s find out more on how DMR really works and why it’s worth the hype:

What is DMR Radio, and what does DMR Stand for?

DMR stands for Digital Mobile Radio and is a European-developed international standard of digital radio. This new and versatile technology covers voice and data transmissions, along with conformance testing. It is an affordable and uncomplicated digital solution to analog radio.

There are three different DMR tiers, as defined by the European Telecommunications Standards Institute (ETSI):

  • Tier I: This includes unit-to-unit, unlicensed transmission on public frequencies. DMR Tier 1 is most commonly used by individuals and small businesses looking for short-distance coverage.
  • Tier II: This licensed conventional DMR system is aimed as a replacement for a conventional analog system. It offers a wide-range coverage and high-power communications.
  • Tier III: DMR trunking systems support packet data services, including IPv4 and IPv6 formats. This tier is aimed at organizations looking to benefit from trunking, voice, and data solutions. Trunking systems work efficiently for larger networks, making it possible to allocate any radio frequency to a user. It maximizes radio ‘traffic’ within any set of frequencies.

The Digital Mobile Radio system utilizes the Motorola TRBO protocol, which converts voice transmissions into digital format to send via RF. The technology enables DMR operators to connect with other DMR users and repeaters across the globe.

Furthermore, it also uses the Time-Division Multiple Access (TMDA) technology. It divides a single frequency to create two-time slots or channels. Using this unique technology, you get to communicate on two paths simultaneously while using one frequency.

DMR Radio Uses

Radio systems have changed the game of one-to-one communication, not only as a recreational hobby but also for enterprises. It is gaining popularity at workplaces like airports, warehouses, factories, retail stores, and restaurants, among several others.

Until now, bulky analog radios dominated the radio scene. They were among the most preferred mode of radio transmissions. However, with recent technological advancements, the latest additions to the radio communication industry are digital radios.

DMR is has worked its way in and is gaining popularity to replace their analog counterparts. Compared to analog systems, DMR provides greater audio clarity and more capacity from the same frequencies.

  • You can utilize DMR transceivers for amateur radio. DMR repeaters are linked to one another using a huge network, which spans the entire globe.
  • By selecting various talk groups, you can communicate around the town, across the state, or even across the country! Using a few talk groups, you can also access operators from across the world.
  • With DMR equipment priced as low as 100 dollars, you can venture into the digital radio scene with absolute ease!
  • With the future being digital, several businesses have replaced their analog two-way radios for DMR. Operators can use scanners to hear DMR. This way, scanning hobbyists, who can’t afford high-end or pricier transceivers, can enjoy these transmissions.

It becomes increasingly important for businesses operating at a large scale to offer a quick and effective response. For small businesses like schools, restaurants, and retail units, analog systems meet full requirements.

But, if your workplace is spread over a large area, say five floors, then an analog system cannot meet your needs. For business areas like construction sites, warehouses, large hotels, you need an almost instantaneous system. In that case, choosing DMR radio is your safest bet!

How does DMR Radio Works?

As mentioned above, DMR uses a 2-channel time-division technology. The benefits it offers include improved performance, efficiency, and greater spectrum capacity usage. Let’s take a look at how it functions:

Transmissions are divided into several blocks.

  • Burst: transmissions are typically in the form of 30-second bursts and include one TDMA element.
  • Frame: consists of two bursts of 30-second each.
  • Super-frame: Includes six frames, which are used for voice transmissions.

Outbound base station transmissions are labeled ‘BS TX’ and are transmitted continually when the transceiver is active. Amidst the individual bursts, the BS TX consists of a Common Announcement Channel (CACH) for signaling and traffic management.

On the other hand, mobile stations transmit when there’s data or voice traffic. This process helps to save battery as mobile stations have a limited battery capacity.

Protocol stack

Another element of digital mobile radios is the protocol stack. It comprises three distinct layers, each addressing different areas of control.

  • Layer 1: The air interface layer combines transmit and receive, radio characteristics, frequency and symbol sync, and burst building.
  • Layer 2: Layer 2, also known as the data link layer, involves channel coding, interleaving, link addressing, and media access control.
  • Layer 3: The call control layer integrates maintenance, data call control, activation, set-up, and more!

You can find more details about the DMR layers here.

DMR Frequencies

The DMR units operate between 30 MHz and 1000 MHz. This frequency range is divided into two categories of radio bands:

  • Very High Frequency (VHF): 30 MHz-300 MHz
  • Ultra-High Frequency (UHF): 300 MHz-1 GHz

In light of these frequencies, most DMR gear falls under the ranges of 136-174 MHz and 403-527 MHz. It is crucial to note that while some DMR frequencies are categorized as license-free (DMR Tier I), others require an FCC permit to operate.

Here’s a list of DMR simplex frequencies.

FrequencyRadio BandTalkgroup ID
441.0000UHF99
446.5000UHF99
446.0750UHF99
433.4500UHF99
145.7900VHF99
145.5100VHF99
  • Set Time Slot and Color Code as 1 for the above-listed DMR simplex frequencies.
  • Set Admit criteria to always.
  • Set In Call criteria to always.

How to use DMR Radio?

Although designed as an uncomplicated radio system, there are a few steps to note before getting started with Digital Mobile Radio.

  1. Before getting DMR equipment, you must first verify if you are located within the DMR coverage area. Use a DMR repeater map to verify.
  2. In addition to this, you will need to learn DMR jargons to avoid confusion.
  3. Several radio systems require obtaining a license. Digital mobile radio, on the other hand, does not require a permit. However, you will need a Radio ID, which may be obtained from https://register.ham-digital.org/.
  4. Log on to the website and fill in the required information. You will need official FCC documents with your callsign. Post the registration process; you will receive an email within 24 hours with your unique radio ID.
  5. Once you receive your Radio ID, you will need to program it into your radio, preferably through computer software.
  6. Next, you will need DMR-capable equipment. We highly recommend BTECH DMR-6X2 for its all-rounded performance. For budget needs, you can check out Retevis RT84.
  7. You will also require a programming cable and PC software compatible with your DMR transceiver. You can also look into external antenna whips and earsets.
  8. Once you have purchased all the equipment, you’re free to program your radio to benefit from an extensive range of frequencies.

DMR language

  • Code plug: This file includes all of your radio’s settings, talk groups, contacts, and repeater information. You can generate code plugs from CSV (Microsoft Excel) files.
  • Color code: Like the amateur CTCSS codes, DMR uses color codes ranging from 0 to 15. In that case, a radio configured with color code one cannot transmit on a repeater programmed with color code 2. DMR radios can be programmed with multiple color codes.
  • Contacts: This holds user data against their DMR ID, including information like your name, call sign, and location. This information can be obtained to add to your code plug. Doing so will display user information instead of the standard DMR ID.
  • Time slots: A repeater can operate as two using time slots. It reduces the bandwidth requirement on digital mobile radio.
  • Talk groups: Talk groups are stored in the contact section of the code plug. They cover national and international links, which directs your QSO to a different location. You can find several talk groups on the Brandmeister network.
  • DMR ID: As mentioned above, all-digital mobile radio users must obtain a DMR ID number, holds all user details.
  • Promiscuous mode: This unique feature may not be available on all radio models. It enables DMR radios to pick up activity on active talk groups, having the same frequency, and configured color codes.

How to Program a DMR Radio?

Programming is a vital part of DMR radios, especially if one wants to connect with a DMR repeater.  Updating and configuring your radio transceiver requires a programming cable and software that is compatible with your radio. While some devices include these two accessories, others need to be purchased separately.

Setting up the code plug for the first time may appear like a daunting task, but we’ve made sure to simplify it for you. Here’s how to set up code plugs on your transceiver using the four parameters of DMR programming:

  1. Firstly, you need to identify the talk groups desired using their name and group ID.   You can arrange these as local repeaters, those from surrounding states, National Talk Group, and so on.
  2. Perform an Echo Test (TG 9998) to check the audio quality and distortion.
  3. Next, enter channel information, including frequency, color code, time slot, and power. Make sure to enter the time slot correctly.
  4. Lastly, you will need to arrange the channels in ‘zones.’ You can set these in any order you like. Some radios allow users to store up to 16 radio channels in a zone.

What are DMR repeater and hotspots?

When it comes to DMR, the two ways to access the worldwide network are via a repeater or a hotspot. The network associated with repeater operation is DMR-MARC. On the other hand, the Brandmeister network is the one popularly associated with hotspot operations.

Although DMR units can communicate with one other directly, this isn’t always an ideal situation. Obstructions like terrain conditions, trees, and buildings can hamper the signal quality. By adding in a DMR repeater, radios can send their messages through a central point.

The repeater acts as that central point, which forwards the message to the rest of the system.

A hotspot, on the contrary, is your internet gateway to a DMR network. When you don’t have access to a nearby DMR repeater, you can use a hotspot instead.

  1. In terms of connection, Hotspot operation requires a stable internet connection.
  2. On the other hand, for repeaters, you can direct connection to repeater networks. Similarly, for repeaters, you can TX/RX from local radio to radio compared to network connection for hotspots.
  3. Speaking of handheld coverage, the repeater should ideally be within the range of another.
  4. Contrastingly, hotspot handheld coverage is dependent on a Wi-Fi connection. When using a Wi-Fi connection, the handheld should be in the cellular signal range.

Whether you should opt for repeaters or hotspot is entirely dependent on your needs. For individuals not in the digital voice repeater range, DMR hotspots are essential for accessing digital voice systems. They’re also able to access all-state talk groups. 

Another key benefit of using a hotspot is that it takes a single channel to tune into the Brandmeister network. On the contrary, repeater networks require separate channels, frequency, color code, and contacts for every repeater.

Conclusion

With DMR being a public, open standard, several businesses are replacing analog systems with digital radios. By switching to DMR, users enjoy double capacity, superior audio quality, supply security, and many other benefits. This latest technology also incorporates data services like GPS and SMS.

Compared to traditional analog systems, the DMR standard is certainly a better choice for utility organizations looking to upgrade! Given the comprehensive and advanced services offered by DMR, we highly recommend users to opt for Digital Mobile Radio.