1. Internet-Connected Amateur Radio Systems APRS, D-Star, Echolink, IRLP

2. Automatic Packet Reporting System (APRS) Digipeater(s) IGate AX25 Internet PC Radio (with GPS) IGate APRS Server AX25

3. APRS Characteristics Provides a data transfer system mainly used for sending GPS data Store and forward digipeaters intelligently relay data on the same frequency IGates pass data from the on-air APRS network to the APRS Internet System (APRS-IS) made up of APRS servers PCs use a browser to access APRS data

4. Internet Radio Linking Project (IRLP) Voice Repeater Analogue Internet Radio (with DTMF) IRLP Node IRLP Reflector Analogue IRLP Node

5. IRLP Characteristics Provides voice comms between radios Uses standard voice repeaters Destination node selected by DTMF tones IRLP nodes provide RF gateway to Internet Gateways normally located at Amateurs’ homes Reflector provides conferencing function Requires proprietary hardware in computer

6. EchoLink Voice Repeater Analogue Internet Radio (with DTMF) EchoLink Node PC Analogue EchoLink Node

7. EchoLink Characteristics Provides voice communications between radios or between PCs and radios Uses standard voice repeaters Destination node selected by DTMF tones EchoLink nodes provide RF gateway to Internet Gateways normally located at Amateurs’ homes EchoLink conference servers available Callsign must be validated before use Nodes can bar connections based on callsign

8. D-Star - Digital Smart Technologies for Amateur Radio D-Star Repeater Digital Internet Radio (with D-Star) IRLP Node PC with DV-Dongle Digital D-Star Node

9. D-Star Characteristics Provides voice and data communications between radios or between PCs and radios Uses specialised D-Star repeaters and radios Destination node selected by callsign D-Star Internet Gateway links RF to Internet Gateways normally located at Amateurs’ homes Requires proprietary hardware in radio D-STAR repeater call sign and IP address must be registered to the gateway server