DIGITAL RADIO for radio amateurs Presented by Johan Lehmann ZS6JPL Welcome – Exciting Fields - Growing AN IARU REGION 1 EVENT HOSTED BY THE SOUTH AFRICAN RADIO LEAGUE

Presentation contents Digital Radio Modulation Digital Radio Equipment Digital Radio Networks Practical Demonstration AN IARU REGION 1 EVENT HOSTED BY THE SOUTH AFRICAN RADIO LEAGUE

1. digital radio Modulation What is Digital and why is it becoming popular – Awesome audio quality – Don’t need ionosphere Popular LTE4DMR

1. digital radio modulation Microphone to carrier to antenna – microphone directly influence the transmitted carrier

1. digital radio modulation Microphone is digitized – digital data can be manipulated – data is compacted – more efficient

1. digital radio modulation Can do one of 3 things with my data – not much different to analogue except extreme – all digital systems use one of these Flip back to previous

1. digital radio modulation Frequency Division Multiple Access – Time Division Multiple Access – Code Division Multiple Access Multiple users at the same time on the same carrier

1. digital radio modulation Made possible with the wonderful world of AMBE Digitize – compress – code – modulate Demodulate – reconstruct - analogue

questions

2. Digital radio equipment 3 used by amateurs – DStar old – DMR new – 100k users – Fusion not very popular

2. Digital radio equipment Voice to repeater – SMS to repeater – GPS to repeater All the same more or less

2. Digital radio Equipment Topic D-Star DMR Fusion Operator Registration Required Yes No Operator Identity Format Callsign Subscriber ID Radio ID Displayed Subscriber ID / Callsign Local QSO Link Multi Repeaters Reflectors Talk Groups / Reflectors WIRES-X Rooms Link Selection Method UR Entry Talk Group Channel Room Name Route to Single Amateur Echo Test Function Request Link Status Does not only do voice – days of DTMF or 1750Hz tone – sends data

2. Digital radio equipment Touch screen keypad for SMS

2. Digital radio equipment Keypad mic for sms and commands

2. Digital radio equipment Commercial – Homemade Radio and micro processor AMBE dongle different

2. Digital radio equipment 1. Handheld Radio 1. Repeaters 2. Mobile Radio 2. Hotspots 3. AMBE Dongle and Software 3. Internet What I have and what I need

2. Digital radio equipment Who am I, How does the world know me ? Subscriber ID / Callsign What is the starting point for my transmission ? Repeater / Gateway / Hotspot What is my destination where I need to end and any instructions for my transmission ? User / Repeater / Reflector Information to transmit for data to find its way

questions

3. Digital radio networks Accepts Incoming Connections from Repeaters, Hotspots and Users Interprets User Commands and Routes Data via the Internet Receives Data from the Internet and Routes to Repeaters, Hotspots and Users

3. Digital radio networks - dstar US trust – ircDDB – Openquad

3. Digital radio networks - fusion

3. Digital radio networks -dmr Motorola – Phoenix – Brandmeister

3. Digital radio networks REF Reflector (DPlus) DCS Reflector (DExtra) Wires-X Bridge XLX / XRF Reflector (Both) DPRS Ref the oldest – XLX / XRF latest APRS on its own – collects data from traffic

3. Digital radio networks Growing everyday exponentially – Multi Protocol is becoming the future

THANK YOU Johan Lehmann ZS6JPL jlehmann@csir.co.za TG655 (DMR) ZS6VTS_B (DStar)