DMR: Where We Are and Where We Are Headed ROGER MULL, KD4JQJ MARV HOFFMAN, WA4NC Shelby Hamfest September 3, 2016

DMR Basic Introduction to DMR Basic Introduction to DMR How Does It Work? How Does It Work? PRN Infrastructure PRN Infrastructure How Widespread is the Use of DMR? How Widespread is the Use of DMR? What Equipment Do You Need to Get on DMR? What Equipment Do You Need to Get on DMR? DMR Networks DMR Networks Where are We Headed? Where are We Headed?

DMR Basics - 1 DMR Technical Standard set by the European Technical Standards Institute. Originally developed for Business applications. First MOTOTRBO radio produced in 2007 DMR Technical Standard set by the European Technical Standards Institute. Originally developed for Business applications. First MOTOTRBO radio produced in 2007 Time Division Multiple Access promotes spectral efficiency involving a single 12.5 KHz channel used by two 6.25 KHz equivalent digital channels Time Division Multiple Access promotes spectral efficiency involving a single 12.5 KHz channel used by two 6.25 KHz equivalent digital channels Forward Error Correction and Digital Signal Processing improve audio quality Forward Error Correction and Digital Signal Processing improve audio quality

DMR Basics - 2 DMR is popular because it offers: DMR is popular because it offers: Cleaner audio with no static Cleaner audio with no static Repeaters can carry two conversations at the same time Repeaters can carry two conversations at the same time One repeater, one antenna, one duplexer but two “channels” One repeater, one antenna, one duplexer but two “channels” Extended battery life on portables Extended battery life on portables Low cost mobiles and portables Low cost mobiles and portables Highly reliable repeaters built to commercial standards Highly reliable repeaters built to commercial standards

DMR Basics - 3 Each second a portable or mobile is keyed is divided into 30 equal segments Each second a portable or mobile is keyed is divided into 30 equal segments Time Slot 1 has segments 1, 3, 5, 7, etc Time Slot 1 has segments 1, 3, 5, 7, etc Time Slot 2 has segments 2, 4, 6, 8, etc Time Slot 2 has segments 2, 4, 6, 8, etc PTT from mobile or portable initiates connect request and identifies user PTT from mobile or portable initiates connect request and identifies user Radio responds with a connect tone if in range of the repeater Radio responds with a connect tone if in range of the repeater Radio bonks if no reply from repeater Radio bonks if no reply from repeater

How Does it Work? Time Division Multiple Access is at the Heart of DMR

DMR Basics - 4 Each radio has a codeplug. Each radio has a codeplug. In CPS DMR repeaters are in ZONES In CPS DMR repeaters are in ZONES Radios generally can hold up to 16 channels (talkgroups) per zone (repeater). MOTOTRBO 7550 and 5550 can hold more channels per zone. Radios generally can hold up to 16 channels (talkgroups) per zone (repeater). MOTOTRBO 7550 and 5550 can hold more channels per zone. A talkgroup is a digital grouping of common users A talkgroup is a digital grouping of common users In a codeplug, each channel contains TX and RX frequency, TOT, admit criteria, talkgroup, plus radio parameters In a codeplug, each channel contains TX and RX frequency, TOT, admit criteria, talkgroup, plus radio parameters

DMR Basics – 5 Improved Audio Quality with DMR

Digital Mobile Radio Popularity Digital Mobile Radio is currently one of Amateur Radio’s fastest growing modes Digital Mobile Radio is currently one of Amateur Radio’s fastest growing modes 2900 User ID’s worldwide in User ID’s worldwide in User ID’s worldwide in User ID’s worldwide in 2016

DMR Beginnings in NC Pioneers were W4ZO, KI4M and K4ITL who created PRN system with linked MOTOTRBO repeaters in Charlotte and Raleigh in 2011 Pioneers were W4ZO, KI4M and K4ITL who created PRN system with linked MOTOTRBO repeaters in Charlotte and Raleigh in 2011 MOTOTRBO architecture and high cost of equipment at the time initially limited growth due to Master-Slave (peer) arrangement requiring a daisy chain setup MOTOTRBO architecture and high cost of equipment at the time initially limited growth due to Master-Slave (peer) arrangement requiring a daisy chain setup In 2011 there were approximately 25 PRN Users in North Carolina In 2011 there were approximately 25 PRN Users in North Carolina

There has been significant Growth in North Carolina 44 Linked PRN repeaters in North Carolina 16 non PRN repeaters in North Carolina 1235 sequentially issued user id’s in NC User ID (WA4NC) issued 8/2012 User ID (KC4ZSM) issued 3/2014 User ID (KE4KFV) issued 10/2014 User ID (W4JJO) issued 3/2015 User ID (KM4NCP) issued 10/2015 User ID (KM4MBS) issued 10/31/15 User ID (WR4AGC) issued 8/26/16 DMR Popularity - 1

There also has been significant growth in South Carolina 565 sequentially issued User ID’s in SC SC HEART DMR system now has 24 linked repeaters and plans to add 4 more. More information available on scheart.us 16 non-PRN repeaters in South Carolina DMR Popularity - 2

MOTOTRBO Repeaters

Charleston North Repeater

C-Bridge - A Game Changer  This connects repeaters via Internet and routes traffic to and from DMR repeaters  5, 15, 50 Manager (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 70 Kb/s

C-Bridge

C-Bridge- Connection Central

NC C-Bridges  Located in a secure data center near Washington with ultra high speed, super bandwidth capacity and emergency power  PRN has 2 C-Bridges with 50 managers which connect to PRN repeaters as well as other C-Bridges  Routes traffic across PRN network  Capable of scheduling ad hoc or permanent connections between repeaters  Remotely programmable

PRN System C-Bridges NC PRN Bridge #1 NC Bridge #2 (includes VA repeaters) SC PRN Bridge Provides Links to DMR MARC WNC Net CBridge VOL-NET CBridge WV DMR CBridge

PRN Talkgroups Time Slot 1Time Slot 2 AccessTGTimingAccessTGTiming Local /7PRN224/7 TAC 1 (World)8951On Demand TAC310 (North America)310On Demand PRN Chat On Demand PRN Chat On Demand DCI Bridge (Brandmeister) 3100On Demand Echotest9998On Demand On Demand activates Talkgroup when user requests; connection continues for 15 minutes after end of transmissions or when Clear Timeslot is activated

New Addition: PRN Chat 1 and Chat 2 Allows “On Demand” connections between two or more PRN Repeaters in NC, SC and VA. Developed to shift extended length user conversations off PRN Talkgroup and to avoid use of TAC310 which is connected to many North America C-Bridges Not available outside the PRN System

“Regional” PRN Locals GREENSBORO = King + GSO Browns Summit RICHMOND = Richmond + South Hill CHARLESTON = North Charleston + Downtown Charleston + South Charleston COLUMBIA = West Columbia + Downtown Columbia + East Columbia RALEIGH = Cary + Raleigh HIGH COUNTRY = Boone + Sugar OUTER BANKS = Hatteras Nags Head DOWN EAST = Ahoskie + Englehard + Hertford

NCPRN Last Heard

Traffic on PRN System 90% of traffic occurs on local talkgroups PRN often used as calling channel and for repeater to repeater traffic TAC310 could be used for in-system traffic but Chat 1 and Chat 2 are preferred. Use TAC310 for connections to other systems SC has added SC Call talkgroup which activates all SC repeaters

Continued DMR Growth Proliferation of low cost ($150-$300) radios Proliferation of low cost ($150-$300) radios CS750 portable-2000 channels, 65k ID’s CS750 portable-2000 channels, 65k ID’s CS800 Mobile-2000 channels, 65k ID’s CS800 Mobile-2000 channels, 65k ID’s Tytera MD380 portable - $98 Tytera MD380 portable - $98 Used MOTOTRBO Radios - $250-$400 Used MOTOTRBO Radios - $250-$400 Low Cost Multimode Add-ons for use with PC’s Low Cost Multimode Add-ons for use with PC’s DVMINI4 USB sticks/DV mega boards DVMINI4 USB sticks/DV mega boards

Most Ham DMR Systems Operate on UHF Frequency coordination easier on UHF than on VHF Frequency coordination easier on UHF than on VHF More UHF repeater pairs, somewhat less crowded spectrum More UHF repeater pairs, somewhat less crowded spectrum Coordinators, including SERA, approved splinter frequencies for digital repeaters Coordinators, including SERA, approved splinter frequencies for digital repeaters VHF seldom used except near Cape Cod and California due to PAVE PAWS radar restrictions, some VHF in MD-DC VHF seldom used except near Cape Cod and California due to PAVE PAWS radar restrictions, some VHF in MD-DC

Popular DMR User Radios

WNC System Repeaters-N4DTR PRN talkgroup available on demand WNC Group uses different talkgroup list than used on NCPRN WNC Marion WNC Asheville WNC Hendersonville WNC Waynesville WNC Franklin WNC Murphy (Future) Net on WNC TG - Thursday at 8:30

High Country UHF Digital Net Tuesday at 8 p.m. Boone Local Sugar Local Wilkes Local Lenoir Local West Jefferson Local Spruce Pine Local Wytheville Local Crowders Local

Where are We Headed? Large growth in Brandmeister traffic Potential for PRN links to NWS Offices Untapped potential for ARES/Auxcomm Networking Lack of Coordination Among Networks

Take Away - DMR Positives One repeater, one antenna, one feedline, one duplexer but two voice channels One repeater, one antenna, one feedline, one duplexer but two voice channels TDMA offers improved audio clarity over analog repeaters in fringe areas TDMA offers improved audio clarity over analog repeaters in fringe areas TDMA lengthens battery duty cycle TDMA lengthens battery duty cycle Availability of lower cost portables and mobiles Availability of lower cost portables and mobiles

QUESTIONS?