DIGITAL MOBILE RADIO SOLUTIONSSOLUTIONS

Digital Mobile Radio (DMR) is an open digital mobile radio standard defined in the European Telecommunications

Standards Institute (ETSI) Standard TS 102 361 parts 1–4 and used in commercial products around the world. DMR,

along with P25 phase II and NXDN are the main competitor technologies in achieving 6.25 kHz equivalent

bandwidth using the proprietary AMBE+2 vocoder. DMR and P25 II both use two-slot TDMA in a 12.5 kHz channel,

while NXDN uses discrete 6.25 kHz channels using frequency division.

DMR was designed with three tiers. DMR tiers I and II (conventional) were first published in 2005, and DMR III

(trunked) was published in 2012, with manufacturers producing products within a few years of each publication.

HQT has developed private network solutions with integrated hardware and software and provides product

series covering DMR Tier-II series. HQT TI OMAP SERIES products are fully self-developed and high-end digital,

which are completely compliant with ETSI TS 102 361 protocol. Besides, all HQT TI OMAP SERIES products can

be upgraded to DMR Tier III without buying any new devices.

DMR Tier II covers licensed conventional radio systems, mobiles and hand portables operating in PMR frequency

bands from 66–960 MHz. The ETSI DMR Tier II standard is targeted at those users who need spectral efficiency,

advanced voice features and integrated IP data services in licensed bands for high-power communications.

ETSI DMR Tier II specifies two-slot TDMA in 12.5 kHz channels.

12.5kHz Channel

TransmittedSignal 2

TransmittedSignal 1

Digital:12.5kHz TDMA

SLOT 1

SLOT 2

SLOT 2

SLOT 1

SLOT 2

SLOT 1

12.5kHz Channel

RegulatoryEmissionsMask

Today’s Analog12.5kHz FDMA

SLOT 1

SLOT 2

SLOT 2

SLOT 1

SLOT 2

SLOT 1

Tim

e

Frequency

TransmittedSignal

INCREASED CAPACITY WITHIN EXISTING 12.5kHz REPEATER CHANNELS

• One voice call for each channel

• One repeater for each channel

• Two time slots enable two voice calls(or data

transmissions) for each channel

• One repeater does the work of two

• No licesing changes required

What is DMR Radio?

Why Digital?

By comparison with FDMA in the figure above, TDMA offers a proven method for achieving 6.25 kHz equivalency

in 12.5 kHz repeater channels — a major benefit for users of increasingly crowded licensed bands. Instead of

dividing the channel into two smaller slices, TDMA uses the full channel width, dividing it into two alternating

time slots. As a result, TDMA essentially doubles repeater capacity while preserving the well-known RF performance

characteristics of the 12.5 kHz signal. From the perspective of RF physics — that is, actual transmitted power

and radiated emissions — the 12.5 kHz signal of two-slot TDMA occupies the channel, propagates, and performs

essentially the same as today's 12.5 kHz analog signals. With the added advantages of digital technology,

TDMA-based radios can work within a single repeater channel to provide roughly twice the capacity of analog

while offering RF performance equivalent to, or better than, today's analog radio.

Advantages of Two-slot TDMA for professional organizations are listed below:

• Increased Spectral Efficiency

• Advanced Features and Flexibility

• Lower Equipment Costs

• Longer Battery Life

For more information about the difference between FDMA and TDMA, please go to:

http://www.hqtsolutions.com/news-information/tdma-how-it-works.html

The advantages of digital two-way systems include:

• More simultaneous talking paths are possible, and information such as unit ID, status buttons, and enhanced

text messages can be embedded into a single digital radio channel.

• Bandwidth consumption is reduced.

• Digital signals can be handled by standardized antenna systems and existing infrastructure equipment.

• The digital conversion of a user's voice reduces external background noises. And the digital technology

platform is ideal for reducing environmental noise levels during transmission, such as inside noisy manufacturing

and processing plants or outside in windy conditions.

• A number of new software applications are available for use with the digital platform.

• The digital platform provides a migration path that allows for simultaneous use of digital and analog radios.

Improved Audio Clarity

The DMR Digital technology provides improved noise reduction and protects voice quality over a longer

distance than analog, especially noticeable towards the end of the transmission range, where analog radios

will have a lot of static and background noise. The digital processing of the signal allows the receiving radio to

screen out the background noise and reconstruct the signal even when it is very weak. This keeps the transmission

clear and increases the effective range of the digital radios over analog radios where the signal clarity and

strength drops off dramatically at the end of the coverage zone.

Better Battery Life and Power Usage

Getting through a full 10-12 hour work shift on a single battery charge has always been a challenge for the

analog handheld two-way radios. The DMR technology uses the transmitter of the radio only half of the time

compared to a narrowband analog radio, which reduces the drain on the radio's battery almost by half. This

increases the actual talk time of a single battery charge by up to 40 percent. Overall battery consumption per

call is reduced, and longer usage time in the field will be noticed between recharges.

DMR digital radios double the capacity over existing analog equipment

A regular analog two-way radio system uses an entire 12.5KHz narrowband channel to provide a single talk

path for communication. However, the benefit of using a DMR digital radio system is that it supports two

simultaneous and independent calls over the same narrowband 12.5kHz channel. This results in doubling the

channel capacity of the radio system which allows businesses to split departments and users into different

completely independent and private talk groups.

D igital DMR Two-way Radios Instead of Analog

DH-8800DH-8800

HQT has been specializing in developing and providing DMR private network solutions including Emergency

Dispatch System, Digital IP Multi-site Connect System, Real-time Positioning Solution and Commercial Recording

Solution, and products such as DMR Tier-II & Tier-III digital portable radios, digital mobile radio, digital repeater

and dispatch system for several years. Now we are devoting to develop and launch more solutions and products.

HQT DIGITAL TWO-WAY RADIOS

HQT DH-9800

IP67 Standard;

• Large-sized TFT Display;

• Multiple Reprogrammable Buttons;

• Compliant with MIL-STD-810 C/D/E/F/G.

•

HQT DM-9800

256-bit Encryption;

• IP Data/Defined Data;

• Rich Second-developments;

• Support Analog and Digital Modes.

•

HQT DR-9200

IP Multi-site Connect;

• Support Trunking Extensions;

• Adopt TDMA Digital Technologies;

• Support Both Analog and Digital Modes.

•

Shenzhen HQT Science & Technology Co., Ltd.

Tel: (+86)-755-86028800

Fax: (+86)-755-86028872

Website: www.hqtsolutions.com

Address: East of Building M-8, Central Zone, Hi-tech Industrial Park,Nanshan District, Shenzhen, P.R.C. 518057

Learn more about TDMA protocol and

digital mobile radio standards at:

www.dmrassociation.org

DM-9800DR-9200

DH-9800