Information on APRS

Automatic Packet Reporting System (APRS) is an amateur system for real time digital communications of information of immediate value in the local area. It utilizes radio data channels using AFSK with connections to: Internet via iGates, Cellular using SMS and DMR Connections. Data can include Global Positioning System (GPS) coordinates, weather station telemetry, text messages, announcements, queries, and other telemetry. APRS data can be displayed on a map, which can show stations, objects, tracking of moving objects, weather stations, search and rescue data, and direction finding. In many territories It is used for Amateur Balloon Telemetry /data though this is not allowed in the UK, Latvia, and Iran.

Technical Spec.

APRS is transported over the AX.25 protocol using 1200-bit/s Bell modem that uses a 1200 Hz tone for mark (typically a binary 1) and 2200 Hz for space (typically a binary 0). The Carrier frequencies used are different around the world.

• 144.390 MHz — North America, Colombia, Chile, Indonesia, Malaysia, Thailand
• 144.575 MHz — New Zealand
• 144.640 MHz — Taiwan
• 144.660 MHz — Japan
• 144.800 MHz — South Africa, Europe, Russia
• 144.930 MHz — Argentina, Uruguay
• 145.175 MHz — Australia
• 145.570 MHz — Brazil
• 145.825 MHz — International Space Station
• 432.500 MHz — Europe (UHF)

Secondary Station ID

The SSID or Secondary Station Identification is a numbered suffix that is added to your callsign to indicate that it is an additional station. APRS has the facility for up to 16 different SSIDs and certain numbers have been allocated to mean certain activities. The reason this is the case is that doing so made it easy to differentiate between a home station, digipeater, and mobile by using consistent identifiers. The current SSID recommendations to use:

• 0 Your primary station usually fixed and message capable
• 1 generic additional station, digi, mobile, wx, etc
• 2 generic additional station, digi, mobile, wx, etc
• 3 generic additional station, digi, mobile, wx, etc
• 4 generic additional station, digi, mobile, wx, etc
• 5 Other networks (Dstar, Smart Phones, etc)
• 6 Special activity, Satellite ops, etc
• 7 hand held Transceivers or other human portable
• 8 boats, sailboats, RV’s or second main mobile
• 9 Mobiles or trackers
• 10 internet, Igates, echolink, winlink, AVRS, APRN, etc
• 11 balloons, aircraft, spacecraft, etc
• 12 APRStt, DTMF, RFID, devices, one-way trackers, etc
• 13 Weather stations
• 14 Truckers or generally full time drivers
• 15 generic additional station, digi, mobile, wx, etc