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DMR and dPMR^®

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Overview
Related Systems
Our Role
RF Demonstrator for dPMR®
·        Typical Results
·        What can I do with my ATB010?
·        How do I get an ATB010?
Glossary
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Overview

dPMR^® and DMR are two new digital technologies for PMR voice/data radios. Both technologies have been standardised by ETSI. The DMR system is a two-slot TDMA system offering a range of features and applications (ETSI Standards TS 102 361 and EN 300 113). dPMR^® is a FDMA system offering the lowest cost digital voice solution and a similar set of repeater and trunking options to DMR (ETSI Standards TS 102 490, TS 102 658 & EN 301 166).

Both standards use 4-FSK modulation variants, DMR using 9600 bps in 12.5 kHz channels and dPMR 4800 bps in 6.25 kHz channels. Both use voice digitally coded with error correction at 3.6 kbit/s.

DMR primarily supports Tier II and Tier III operation (i.e networked solutions). dPMR was initially  designed as a peer-to-peer solution (standard TS 102 490) however ETSI has also produced a standard combining direct-mode, repeater and trunked operation (TS 102 658). Both DMR and dPMR can be used in the 446.1 MHz license exempt band which has been designated by CEPT ECC (ECC/DEC/(05)12). The lack of support for peer-to-peer operation in DMR and the fact that dPMR^® is inherently more suitable for very low cost terminal designs, along the lines of the current analogue PMR446, means dPMR^® is the preferred technology of licence-free operation. DMR and dPMR^® compete head-to-head in the market for licensed systems.

More information on dPMR^® is available in our article published in Land Mobile magazine in March 2008.

Related Systems

Variations of the European 6.25 kHz dPMR^® technology have been adopted in a number of countries worldwide. In Japan the DCR standard (ARIB STD T-98) is closely related, as is the NXDN^TM standard promoted by the NXDN^TM Forum in the USA and elsewhere. In China the Digital Radio Association (DRA) is working on a standard called NDR which may well be closely associated to dPMR^® technology.

Our Role

Applied Technology is involved in the development of these technologies and now chairs the ETSI working group that has developed the standards. In association with our parent company we are also active members of the dPMR^® MoU group (including chairing the MoU Technical Working Group)

Based on our standardistion experience and a range of developments for dPMR^®, NXDN^TM and DCR, Applied Technology can offer a range of product design services including:

• Design of RF solutions compatible with the CMX7131/41 and CMX8341 solutions for dPMR^®, NXDN^TM and DCR
• RF Demonstrator for the dPMR^® – ATB010
• Design solutions for DMR radio
• Product design consultancy
• Consultancy on standardisation and inter-operability
• 4-FSK Modems based on CMX7031/7041, CMX7143 and CMX7164.

The CMX7131/41 and CMX8341 solutions offers a very low cost solution for dPMR and dual mode analogue FM / dPMR^® designs with excellent performance.

 To find out more contact us at enquires@app-tech.co.uk.

RF Demonstrator for dPMR^®

The ATB010 PCB is a small, low cost, RF technology demonstrator aimed at speeding manufacturers' design and development of dPMR / PMR446 transceiver products. The board is designed to plug in to the CML Microcircuits DE6181 demonstration kit for the CMX7131/41 and CMX8341 integrated circuit.  Along with a PE0002 host controller, (also available from CML Microcircuits) a full RF transceiver can be assembled with a variety of voice and data options configurable via Function Imageä and control scripts.

 All the necessary RF circuits are provided on the ATB010 PCB: receive and transmitter VCOs, a 500 mW RF power amplifier, harmonic filter, antenna switching, LNA, RF to IF mixer and limiter discriminator IF processing. The RF performance is designed to be compliant with EN 301 166 (6.25 kHz dPMR^®) and EN 300 296 (12.5 kHz PMR446). The DE6181 demonstration kit is a flexible platform that can provide both digital (dPMR^®) and analogue (PMR446) functionality.

 The design is production engineered for low bill of materials cost, with a minimum number of component types and values and uses only low-cost off-the-shelf components. The design uses a single 3.6V supply e.g. 3 AAA cells or a LiON battery.

Note: ATB010 itself is a demonstration PCB and has not been approved to any product standards. The user is advised not to radiate signals using the ATB010 without complying with the local regulatory requirements, for example obtaining a test and development licence from the appropriate national body.

Typical Results

All results for 6.25 kHz digital mode unless otherwise stated.

dPMR^®  Modulation Spectrum using CMX7131/41 (DE6181) and ATB010

What can I do with my ATB010?

ATB010 together with a DE6181 + PE0002 and PC controller can be used to demonstrate dPMR^® / PMR446 technology. The test system is capable of:

• Analogue FM (12.5 kHz) PMR446 transmission or reception

• Digital dPMR (6.25 kHz) transmission or reception

• Operation 446.0 MHz to 446.2 MHz (frequency resolution = 3.125 kHz)

• Send / receive status messages with other dPMR equipment.

• Make voice calls to dPMR equipment using a RALCWI vocoder.

• With two ATB010 / DE6181 / PE0002 systems digital mode voice calls can be made using the CMX618 Vocoder IC provided on the DE6181.

How do I get an ATB010?

ATB010 is no longer available, for further information on dPMR solutions please contact enquiries@app-tech.co.uk.

Glossary

ATB010                   Demonstration PCB for dPMR radio

4FSK                        For- Level Frequency Sift Keying

direct mode            Mode of operation where units may communicate outside the control of a network (i.e. mobile to   mobile)

CSF                          Configured Services and Facilities

DCR                         Digital Convince Radio, used in Japan (ARIB STD T-98)

DE6181                   Demonstration PCB for CMX7141 and CMX6x8 Integrated circuits

dPMR^®                    digital Private Mobile Radio (dPMR^® is a registered Trade Mark of the dPMR MoU Association)

DMR                         Digital Mobile Radio

DRA                         Digital Radio Association (Group of Chinese companies working to standardise dPMR like solution in China)

ECC/DEC/(05)12   ECC Decision of 28 October 2005 on harmonised frequencies, technical characteristics, exemption from individual licensing and free carriage and use  of digital PMR 446 applications operating in the frequency band 446.1- 446.2 MHz

ERC/DEC/(98) 25  ERC Decision of 23 November 1998 on the harmonised frequency band to be designated for PMR 446

EN 300 113             ETSI Standard covering radio parameters for DMR

EN 301 166             ETSI Standard covering radio parameters for dPMR

FEC                          Forward Error Correction

IFS                            Initial Services and Facilities

FRS                          Family Radio Service (US licence exempt radio system)

NDR                         National Digital Radio (Chinese standard being developed by DRA)

NXDN^TM                 6.25 kHz standard promoted in USA principally by manufacturers Icom and Kenwood.

RALCWI                  Robust 2400 bit/s Vocoder (3600 bit/s with FEC)

TS 102 361             Technical Requirements for Digital Mobile Radio (DMR)

TS 102 490             Peer-to-Peer Digital Private Mobile Radio using FDMA with a channel spacing of 6,25 kHz with e.r.p. of up to 500 mW

TS 102 658             dPMR Mode 1, 2, 3 Standard

TR 102 398            ETSI Guide to DMR Technology

TR 102 884             ETSI Guide to dPMR Technology

Peer to Peer          Another name for ‘Direct Mode’ operation

PMR                         Private (or Proffesional) Modile Radio

PMR446                  License exempt PMR System in the 446MHz band in Europe.

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