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DMR and dPMR
dPMR
and DMR Overview
dPMR and DMR are two new digital
technologies for low cost voice 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 lowest cost
digital voice solution with the same voice quality as DMR (ETSI
Standards TS 102 490 & EN 301 166).
DMR supports Tier I, Tier II and Tier III
operation. Today dPMR is designed as a peer-to-peer solution although
ETSI is currently working on a standard for Tier II facilities for
dPMR which will be published as document TS 102 658. Both DMR and dPMR
can be used in the 446.1MHz license exempt band which has been
designated by CEPT ECC (ECC/DEC/(05)12). The nature of dPMR however
makes it inherently suitable for very low cost terminal designs, along
the lines of the current analogue PMR446 units in the adjacent
frequency band (ERC/DEC/(98)
25). More information on dPMR is available in
our article
published in Land Mobile magazine in March 2008. Applied
Technology is involved in the development of these technologies
and attends 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. Applied Technology can offer a range of product design services including:
The CMX7141
solution 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
All
the necessary RF circuits are provided on the ATB010 PCB: receive and
transmitter VCOs, a 500mW 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 (6.25kHz dPMR) and EN 300 296 (12.5kHz 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 Li-ion battery. Full design information is available for download! – free of charge! To get access all you have to do is register. Information includes: manual, schematics, PCB layout, DE6181/PE0002 scripts, etc. Also available is the product brief including information on how to order ATB010 PCBs. Typical Results All
results for 6.25kHz digital mode unless otherwise stated.
dPMR
Modulation Spectrum using CMX7141 (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 (12.5kHz) PMR446 transmission or reception ·
Digital dPMR (6.25kHz) transmission or reception ·
Operation 446.0MHz to 446.2MHz (frequency resolution =
3.125kHz) ·
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. 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. GlossaryATB010
Demonstration
PCB for dPMR radio 4FSK
Four-Level
Frequency Shift 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 DE6181
Demonstration PCB for CMX7141 and CMX6x8 Integrated
circuits dPMR
digital Private Mobile Radio DMR
Digital Mobile Radio 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 IFS
Initial Services and Facilities FRS
Family Radio Service (US licence exempt radio system) RALCWI
Robust 2400bit/s Vocoder 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 Tier II Standard PMR446
License
exempt PMR System in the 446MHz band in Europe.
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| © 2007 Applied
Technology (UK) Ltd A Member of CML Microsystems Plc |
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