PulseModem A is an APRS client, that reads and reports APRS location and message.
APRS stands for: Automatic Packet Reporting System.
APRS is a digital communications protocol that can exchanges information among large number of stations both local and global.
You as a licensed Amateur Radio operators can send and receive APRS location and message in 2 ways:
Full AX.25 software AFSK modem is available for off-the-grid operations.
You can connect directly with the global APRS-IS network by Internet. Messages reaching the gateways will be relayed to the APRS-IS feed.
The PulseModem A will display messages from the APRS-IS, 100km around your current location.
APRS messages are short in length, in less than 100 bytes.
Messages are encoded in AX.25 protocol with Bell 202 AFSK modulation.
PulseModem A will play the encoded message through the audio port of your iOS device, to your radio.
Once your messages are received directly with the APRS-IS online, or a nearby radio stations, your message will appear through the APRS-IS feed.
Your positions and messages will then be available worldside on other APRS clients and websites, such as https://aprs.fi/