MARV HOFFMAN WA4NC mkhoffman2006gmailcom NC AUXCOMM WESTERN BRANCH MEETING OCTOBER 31 2015 DMR What is It How Widespread is its Use What equipment is needed to use DMR Implications for ID: 694446
Download Presentation The PPT/PDF document "A Status Report on DMR in North Carolina" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
A Status Report on DMR in North Carolina
MARV HOFFMAN, WA4NC
mkhoffman2006@gmail.com
NC AUXCOMM
WESTERN BRANCH MEETING
OCTOBER 31, 2015Slide2
DMR
What is It
?
How Widespread is its
Use?
What equipment is needed to use DMR
?
Implications for
AuxcommSlide3
Digital Mobile Radio Basics
Digital Mobile Radio is currently one of Amateur Radio’s fastest growing modesSlide4
DMR Basics - 2
DMR is popular because it offers:
Superior audio
Repeaters can carry two conversations at the same time
Extended battery life on portables
Low cost mobiles and portables
Highly reliable repeaters built to commercial standardsSlide5
DMR Basics -3
DMR Technical Standard set by the European Technical Standards Institute
Time
Division
Multiple Access promotes
spectral efficiency involving
a
single 12.5
khz
channel
used for
two 6.25
khz
equivalent
d
igital channels
Forward Error Correction and Digital Signal Processing improve audio qualitySlide6
Time Domain Multiple Access is at the Heart of DMRSlide7
There is Improved Audio Quality with DMRSlide8
Most Ham DMR systems are UHF
Frequency coordination easier
on
UHF than on VHF
More UHF repeater pairs, somewhat less crowded spectrum
Coordinators, including SERA, approved
splinter frequencies for digital
repeaters
VHF seldom used except near Cape Cod and California due to PAVE PAWS radar restrictionsSlide9
DMR Positives
One repeater, one antenna, one feedline, one duplexer but two voice channels
TDMA offers improved audio clarity over analog repeaters in fringe areas
TDMA lengthens battery duty cycle
Availability of lower cost portables and mobilesSlide10
Mototrbo RepeatersSlide11
Popular DMR RadiosSlide12
C-BridgeSlide13
C-Bridge - A Game Changer
This
c
onnects repeaters via Internet and routes traffic to DMR repeaters
5, 15, 50 Repeater models available
C-Bridges can talk to each other and import
talkgroups
, overcoming the daisy chain model
Reduced connectivity bandwidth requirements for each repeater from 1.1 Mb/s to 50kb/sSlide14
C-Bridge- Connection CentralSlide15
PRN C-Bridge
Located in a secure data center with ultra high speed, super bandwidth capacity and emergency power
PRN has 50 managers which connect to PRN repeaters as well as other
CBridges
Routes traffic across PRN network
Capable of scheduling ad hoc or
permanent connections
between
repeaters
Remotely
programmableSlide16
PRN Talkgroups
Time Slot 1
Time Slot 2
Access
TG
Timing
Access
TG
Timing
Local
27500
On Demand
PRN
2
24/7
TAC
1 (World)
8951
On
Demand
TAC310 (No America)
310
On Demand
Southeast
3174
On Demand
DCI (West Coast)
3100
On
Demand
Simplex
99
On Demand
Echotest
9998
On Demand
Clear Time Slot
27000
On
Demand
On Demand activates
Talkgroup
when user requests; connection continues for 15 minutes after end of transmissions or when Clear Timeslot is activatedSlide17
DMR Beginnings in NC
Pioneers were W4ZO, KI4M and
K4ITL
who created PRN system with
linked
MOTOTBO repeaters in Charlotte and Raleigh in
2011
MOTOTRBO architecture and high cost of equipment initially limited system growth due to Master-slave (peer) arrangement in daisy chain
setup
In 2011 there were approximately
25
PRN Users in North CarolinaSlide18
DMR Expansion in NC Due To:
Easy access to used
Mototrbo
equipment on
Ebay
and from
dealers
Major expansion came with the development of affordable C-Bridge that expanded maximum number of repeaters and the number of talk
groups
Development of Connect System
CS700
portables in 12/2013 at $180 costSlide19
26 PRN Repeaters in NC
INSERT PRN MAP HERESlide20
PRN Coverage in Western NC
INSERT PRN MAP HERESlide21
NCPRN Last HeardSlide22
Traffic on PRN System
90% of traffic occurs on local
talkgroups
PRN often used as calling channel and for repeater to repeater traffic
TAC310 is also used for in-system traffic and for connections to other systemsSlide23
Current Factors Driving Growth of DMR
Proliferation of low cost ($150-$300
)
radios
CS750 portable-2000 channels, 65k id’s
CS800
Mobile-2000 channels, 65k id’s
Tytera
MD380 portable
Hytera
PD365 portable
Baofeng
and
Kirisun
portablesSlide24
26 PRN Repeaters in North Carolina
Significant User Growth in North Carolina
Sequentially issued user id’s
User ID 3137041 (WA4NC) issued 8/2012
User ID 3137105 (KC4ZSM) issued 3/2014
User ID 3137264 (KE4KFV) issued 10/2014
User ID 3137379 (W4JJO) issued 3/2015
User ID 3137617 (KM4NCP) issued 10/2015
User ID 3137642 (KM4MBS) issued Friday
“Build It and They Will Come” Slide25
Future DMR Applications?
Direct, clear contact between Local
Auxcomm
Coordinators and District
Auxcomm
Coordinators
Statewide linkage for State
Auxcomm
to District and County Coordinators
Direct, clear contact from County EOC to State EOC and EM Branch Offices
Possible installation of DMR radios at NWS for
Skywarn
operationsSlide26
Is Another Game Changer Coming?
CS7000 Portable
Currently under development by Connect Systems
A
nalog, DMR and D-Star in one radio
Claims that future upgrades will include P25, NXDN and Fusion
Myth or Reality?Slide27
QUESTIONS?