Encoding or decoding random radio-waveforms doesn't need incredible expensive hardware anymore which offers new possibilities for building up over-the-air communication systems. There are Software Defined Radios providing affordable cellular radio to remote villages, Community Radios are using SDR to build up digital radio networks and other cool stuff.
Some basic knowledge what is going on in SDR Hard/Software as the influence of the samplerate, I/Q-data of the math behind the waterfall-diagram is helpful to have fun with SDR. Some theory on modulation techniques helps you to decode or encode your waveforms.
With a cheap DVB-T USB receiver used with some SDR-Software you can already have a look whats going on in the airwaves around you at certain frequencies. But what happens between the antenna and your computer display showing or decoding the signal? The talk should give basic information and background about SDR and some modulation theory.
There will probably be a SDR Challenge at the Congress to practice you new skills.