AMATEUR RADIO DATA

What is amateur radio?

Amateur radio — often called "ham radio" — is a hobby and public service that involves operating radio transmitters and receivers under a government-issued licence. Licensed operators (called "hams") are allowed to use a wide range of radio frequencies and can build or modify their own equipment, which makes the hobby an ongoing exercise in practical radio engineering.

The licence part is important: unlike the unlicensed radio used by Meshtastic or Wi-Fi, amateur radio operators have identified themselves and are accountable for their transmissions. In exchange, they get access to far more radio spectrum, higher power limits, and the ability to build infrastructure-grade networks.

What's less well-known is that amateur radio operators have been doing digital data communications for decades. Before the internet became widespread, hams were already building packet radio networks that could carry email and file transfers over the air. Modern ham data networks are substantially more capable.

Why a community would care

APRS — Automatic Packet Reporting System

APRS is a real-time network for position reporting, weather data, and short messages. It operates on a single well-known frequency (144.390 MHz in North America, with regional variations elsewhere). Any radio sending APRS-formatted data on that frequency will be picked up by digipeaters (digital repeaters) that re-broadcast the signal further, and by internet gateways that inject it into the APRS-IS network — an internet backbone for APRS data.

The result is that a tracker in a car, a weather station at a remote cabin, or a handheld radio carried by a hiker can be seen by anyone on the aprs.fi map in real time, as long as there's a digipeater or gateway in range. In populated areas, APRS coverage is nearly universal.

APRS is also used for two-way text messaging between stations, bulletin boards, and real-time object tracking. It's a full messaging network disguised as a position reporting system.

Winlink — email over radio

Winlink is a global network for sending and receiving email via radio. You use the Winlink Express software on a computer, compose an email as normal, and it's transmitted over the air to a Winlink Radio Message Server (RMS) — a gateway station that bridges the radio network and the internet. Your message is delivered to normal email addresses, and you can receive email back the same way.

What makes Winlink remarkable is that the gateway doesn't need to be nearby. Winlink's HF (shortwave) gateways can be hundreds or thousands of kilometres away. A sailor mid-Pacific, a researcher in the Antarctic interior, or a disaster worker in an area with no infrastructure can send and receive real email using only their radio.

Winlink also works in "peer-to-peer" mode without any internet gateway — two stations can exchange mail directly if they can hear each other.

AREDN — Amateur Radio Emergency Data Network

AREDN takes a different approach: instead of adapting radio to carry messages, it modifies commercial Wi-Fi hardware to operate on amateur radio frequencies, using the higher power limits and more spectrum available to licensed operators. The result is a broadband mesh network — similar in concept to community wireless, but operating on frequencies and at power levels that require an amateur radio licence.

An AREDN network can carry voice-over-IP phone calls, video surveillance feeds, real-time data from sensors, and standard TCP/IP networking — all over a self-healing mesh that doesn't depend on any commercial infrastructure. AREDN networks are deployed by emergency management organizations around the world for exactly the scenario where they're most needed: when everything else has failed.

Common software and tools