WHAT IS DMR. ((( dmr ))) A Presentation for the DATA OVER PMR GROUP -
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Transcript of WHAT IS DMR. ((( dmr ))) A Presentation for the DATA OVER PMR GROUP -
WHAT IS DMR
.
(((dmr)))
A Presentation for the DATA OVER PMR GROUP -
PMR BUSINESS MODEL
What is ((dmr))
A LOW COST LOW COMPLEXITY DIGITAL RADIO PROTOCOL
Using a polite protocol?
PMR Business ModelPMR Business Model
WHAT IS DMR(2)
SWISS
What is ((dmr)) (2)
4
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Peer to peer
Repeater
Trunked
ETSI & TEAM
Short MessagesShort Messages
EmailAVLTele
met
r
y
Protection from
Eavesdropping
Licenced
Licence
Exempt
Data
brick
Simultaneous
speech+data
((dmr)) – THE TEAM
WHAT IS DMR
• A Digital PMR Standard serving Existing PMR markets. Licenced and licence exempt
• Fits in existing PMR Spectrum
– MB, VHF & UHF• Conventional ETS 12.5Khz channel (1 carrier/Ch)
– plus 2 channels/carrier and channel sharing
• Range as good as F.M
• Simple LOW COST or fully featured radio’s (including data-bricks)
• Peer to peer OR infrastructure modes SO –
• Fully Scalable from two radio’s to large trunked networks
• A Digital PMR Standard serving Existing PMR markets. Licenced and licence exempt
• Fits in existing PMR Spectrum
– MB, VHF & UHF• Conventional ETS 12.5Khz channel (1 carrier/Ch)
– plus 2 channels/carrier and channel sharing
• Range as good as F.M
• Simple LOW COST or fully featured radio’s (including data-bricks)
• Peer to peer OR infrastructure modes SO –
• Fully Scalable from two radio’s to large trunked networks
What is ((dmr))
FEATURES CIRCLE
Range – Equal to FM
Low cost Terminal
Manufacture
Works out of the box
Good quality Speech
Battery LifeRepeaters2ch/carrier
Plug and Play Data
Scalable from two radio’s to
wide area fleets
Security
TRANSMITTER HAS A 12.5kHz
ANALOGUE MASK
DIFFERENTIATOR FROM FM
(((dmr)))(((dmr)))
Differentiator (from FM)Differentiator (from FM)
• “Free” protection from eavesdropping• “Free” Voice Storage• “Free” Pager• “Free” Simultaneous speech and SMS• “Built-in” Data.• Spectrum Sharing• Two channels/carrier
STARTING WITH 2 UNITS BACK 2 BACK
Starting with two DMR units working back-to-back in licence exempt spectrum
Starting with two DMR units working back-to-back in licence exempt spectrum
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It Works Out of the Box
The Marketing is in the Box
BRICKS
These may be DatabricksThese may be Databricks
WORKING THROUGH A REPEATER
Working through a Repeater
Working through a Repeater
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SUPPORTS TWO SIMULTANEOUS CALLS
One Channel supports two independent
simultaneous calls
One Channel supports two independent
simultaneous calls
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SHARING A CHANNEL
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Independent Repeaters sharing a single channel (in licence exempt spectrum?)
Independent Repeaters sharing a single channel (in licence exempt spectrum?)
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TRUNKED
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Repeaters may be linked
Repeaters may be linked
or sites may have multiple
channels
or sites may have multiple
channels
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DATA
Data
ApplicationAccess Interface
• MAP27
• Custom
• ………………
I am a Mode
m
TEKKI STUFF(1)
Tekki Stuff• Modulation – 4 level FM. Transmitter Mask EN300-113• Symbol Rate 6kb/s. Bit Rate 12kb/s• 20mS slots each of 240 bits unprotected• 18 slots/frame. 4 frames/superframe
STIMULUS (A)20mS
RESPONSE (B)5mS
CPU Processing
5mS TX Ramp
20mS VCO Switch
5mS SYNC tuning and timingPLL
5mS TX Ramp
20mS VCO Switch
(B) will not decode this
(B) will decode this
20mS
(B) will not decode this
(B) will not decode this
(B) will not decode this
Slot requiring a response from (B)
Slot 1 Slot 2 Slot 3 Slot 4 Slot 5 Slot 6
TEKKI STUFF(2)
Tekki Stuff(2)
360mS
Release PTT here
PLL(12)+SYNC(60)+SYS(22)+Recipient Address(18)
Pilot(14)+SenderAddress(18)+VOCODERHEADEROPCODE(8)+VocoderNegotiation(8)
Pilot(14)+TelegramType(2)+Vocoder Data
Pilot(14)+CALLMAINTENANCEOPCODE(8)+PTT ReleaseType
SYNC(60)+SYS(22)+RecipientAddress(18)+WAKEUPOPCODE(8)+WakupSlotNumber(4)
Press PTT here
POWER SAVE
DIVINITY
DATA and divinity
http://www.mod.uk/issues/pcomms/physics.htm
Capacity = Bandwidth x Log2 {1 + Signal to Noise Ratio}
TEXT BOOK
SIMULATIONS
Simulations for DMR
7.2 Kbit/s 4.8 Kbit/s
MER=10 %
MER=1%
MER=10 %
MER=1%
450 MHz - 150 Km/h
15.8 18.4 12 14.2
450 MHz - 50 Km/h
16.8 20.5 12.8 16
150 MHz - 50 Km/h
18.0 23.8 14.2 19.3
66 MHz - 5 Km/h
17.8 28.3 16.1 26.2
Static Conditions
7.8 8.4 6.6 7
THROUGHPUT
Throughput
RA
Signal strength (dbm)
Thr
ough
put
(kb/
s)
-119 -117 -115 -113 -111 -109 -107 -105 -103 -101 -99 -97 -95 -93 -91 -89 -87 -85
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MobileCoverage
PortableCoverage
Tetra 7.2kb/s
Tetra 4.8kb/s
Tetra 2.4kb/s
DMR 7.2kb/s
DMR 4.8kb/s
(((dmr)))Licensed Exempt
PMR446 - equivalentCEPT dedicated harmonised simplex channels in UHF1 (currently considering the PMR446 channels and if market demands further channels in the range 440-450MHz)
More Informations
Licensed PMR & PAMR
3W erp Handheld (max)10W erp Mobile (max)25W erp Base/Repeater (max)
.
More Information
LPRA+URL’s
URL’sMOD web sitehttp://www.mod.uk/issues/pcomms/physics.htm
Shannon Articlehttp://www.fyldemicro.com/dmr/shannon.doc
DMR Articlehttp://www.fyldemicro.com/dmr/what_is_dmr.doc
This Powerpoint Presentationhttp://www.fyldemicro.com/dmr/pmr-dmr.ppt
LPRAThere is an opportunity for the DATA OVER PMR GROUP to influence what DMR becomes. WHAT DO YOU WANT?