QRadioLink is a Linux SDR transceiver application using VOIP, built on top of GNU radio, made for hobbyists, tinkerers and radio enthusiasts, which allows experimenting with software defined radio hardware using different digital and analog modes and a friendly user interface.
Its primary purpose is educational, but it can also be customized for low power data communications on various frequency bands. Can also be used as an amateur radio SDR transceiver for teaching students about radio communications.
Since the software is open source, it can be easily understood and modified. If you want to add your own operating mode to QRadioLink, there is an easy way to do that. All you have to do is create a GRC logical flowgraph containing the blocks that your mode would use. You need not be concerned about how the data gets in and out of the flowgraph. Just create a random source and a null sink and connect the as input and output. Also add a Qt GUI sink to verify the characteristics of your mode. The sources and sinks will be automatically added in the source code with the correct values.
Save the flowgraph in the grc/ folder, create a Github account and submit a pull request to the QRadioLink repository. It may take some time to get the request processed and tested so the changes won't automatically get into the master branch.
It is recommended that you use only standard Gnuradio blocks. If you have to use Gnuradio out-of-tree modules, please add a README file stating the location of the source code and why the module is needed.
Or, if you do not wish to do it yourself, use the mailing list to contact authors and describe the mode's functionality.
Note: QRadioLink currently uses only the default Gnuradio blocks, but that could change in the future.