1. 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

2. 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

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

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

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

6. 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

7. 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

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

9. questions

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

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

12. 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

13. 2. Digital radio equipment
Touch screen keypad for SMS

14. 2. Digital radio equipment
Keypad mic for sms and commands

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

16. 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

17. 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

18. questions

19. 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

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

21. 3. Digital radio networks - fusion

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

23. 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

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

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