The Joint Tactical Radio System (JTRS) aimed to replace existing radios in the American military with a single set of software-defined radios that could have new frequencies and modes (“waveforms”) added via upload, instead of requiring multiple radio types in ground vehicles, and using circuit board swaps in order to upgrade. JTRS has seen cost overruns and full program restructurings, along with cancellation of some parts of the program.

Software-defined radio (SDR) is a radio communication system where components that conventionally have been implemented in analog hardware are instead implemented by means of software on a computer or embedded system. While the concept of SDR is not new, the rapidly evolving capabilities of digital electronics render practical many processes which were once only theoretically possible.