Local & Worldwide Messaging With Amateur Position Reporting System
APRS Packet Overview • Packets Travel from One Digipeater to Another • The Digipeaters are only concerned with distributing APRS type data. • The data can contain Position Information, Objects or Messages • Digipeaters route packets on the air • IGATEs route packets through the internet • GATEs route packets between frequencies
How Does A Digipeater Route A Packet? For now, Let’s ignore the contents and examine the routing. WIDEn-n KB8ZGK-15>GPSLV,RELAY*,WIDE3-3:$GPRMC,163400,A,... KB8ZGK-15>GPSLV,RELAY*,WIDE3-2:$GPRMC,163400,A,... KB8ZGK-15>GPSLV,RELAY*,WIDE3-1:$GPRMC,163400,A,... TRACEn-n KB8ZGK-15>GPSLV,TRACE3-3:$GPRMC,163400,A,... KB8ZGK-15>GPSLV,K9DOG*,TRACE3-2:$GPRMC,163400,A,... KB8ZGK-15>GPSLV,K9DOG*,K9PUP*,TRACE3-1:$GPRMC,163400,A,... KB8ZGK-15>GPSLV,K9DOG*,K9PUP*,K9KAT*, TRACE3-0:$GPRMC,16340..
How Does an APRS Position Report Travel? Since APRS Packets Aren’t Addressed To A Particular Station, Anyone Can Hear Them And If An IGATE Station Hears The Position Report, It Is Passed On To the Internet For Everyone To See The Data Moves Outward In Tiers A Position Report Bounces From One “Digipeater” To Another Internet
Differences Between Messages and Other Types Of Data • All APRS data is broadcast using UI Frames. • All APRS stations hear and display all traffic. • Messages are the only type of APRS data that will cause a station to generate a reply.
How Messages Are Created, Routed, and Acknowledged
Sending Long Distance Messages from APRS • Messages are sent over the air as usual. • An IGATE hears the message and routes it to all other IGATES. • The IGATE nearest the Destination Station retransmits the message out onto the air. • The Destination Station ACK’s the message. • The local IGATE retransmits the ACK and the Destination Station’s position on to the air.
Sending Long Distance Messages from APRS KD4RDB sends message to K4TWE; Nearby IGATE hears it k4twe The IGATE nearest KE4TWE retransmits the message on the air. INTERNET kd4rdb All other IGATEs hear the message but do not retransmit it because they don’t know where K4TWE is.
Sending ICQ Messages with APRS 1.Address your APRS message to ICQSERVE 2.Make the 1st word in the text of the message the ICQ UID number 3.The rest of your message will be sent to the recipient as text 4.You will receive a confirmation message from nearest IGATE *If you register your ICQ UID with the ICQSERVE messages can be sent to your callsign OR ICQ UID number.
Sending EMAIL Messages with APRS 1.Address your APRS message to EMAIL 2.Make the 1st word in the text of the message the EMAIL address 3.The rest of your message will be sent to the recipient as text 4.You will receive a confirmation message from nearest IGATE