Packet radio is an early amateur radio technology that dates back to the early 1980s – a time when a lot of technology was really just finding its feet. Just as many people enjoy listening out for messages via digital police scanners or communicating via two-way radio to create their own HAM radio stations, this provides another exciting way to use this technology.
What is a Data Packet?
Of course, this refers to a ‘data’ packet rather than any kind of container. Packets are ‘units’ of data that get sent via the internet. So if you imagine a communication through your favorite messaging app, then you are going to be sending a lot of information in the form of words and pictures.
This is represented in the form of data – which can be broken down into simple ones and zeros. For an image for instance, you will likely use a ‘raster file’ (JPGs and PNGs are rasters) and this will work like a kind of dot matrix with each pixel plotted out and given a color and position. These pixels can then be further decompressed to ones and zeros, where the ones and zeros are converted via an algorithm into RGB color codes and coordinates.
When you send a picture over these connections, you won’t send it all in one go, but will rather break the information into smaller pieces called ‘packets’. This in turn allows your app to play nice with the bandwidth of the connection.
Here, bandwidth effectively refers to the ‘thickness’ of the internet pipe. In other words, how much data can get through at once. Meanwhile, network latency tells us about how many data packets can be transmitted over a certain period of time – think of this like the speed of the flow of water in said pipe.
If data wasn’t first broken down into packets, then it would all have to try and fit through the pipe at once. And if the pipe wasn’t big enough, then the picture wouldn’t get through – and potentially the connection would go down.
How This Applies to Radio
Packet radio then is another method for sending data between computers. Linux has historically supported this protocol (called AX.25) since 1993.
Once, this technology relied on a piece of hardware known as terminal node controller, or TNC. This is a modem that plugs into a two-way radio, and that uses audio tones to receive and send data. Today, most people will use a program that is able to do the same thing.
Effectively then, packet radio allows two computers to communicate via radio waves, and in this way, it combines the hobby of computing with the hobby of radio.
Sending packets of data is relatively slow in this manner and is therefore not a practical alternative to regular internet protocols. However, packet data does provide a way to ‘further radio art’ as a hobbyist might say, and to have fun. What’s more though, is that it provides a form of communication that many people aren’t aware of, and that allows you to reach much greater distances.
Most towns areas have BBS (packet bulletin board systems) and these allow you to send and receive personal messages, or to send and receive messages for people in a certain region. Whether you end up dabbling in shortwave radio or just staying in touch with a friend via a walkie talkie, there is a huge amount to enjoy once you explore the world of amateur radio!
Image Source: https://www.tapr.org/pr_intro.html