The decisions that the Department of Defense made about its “radios of the future” more than 20 years ago are still having an impact on the communications gear the military services purchase today. The Joint Tactical Radio System program may have ended, but it left behind a legacy that the US Army is now trying to get away from—while still holding fast to parts of JTRS’ framework.

JTRS, as Ars reported in 2012, was DOD’s quest to build the perfect set of communications gear based on software-defined radio (SDR) technology. SDR was in its infancy in the mid-1990s, but the Joint Program Office JTRS (the organization driving the DOD-wide program) was convinced that investing early would pay off with cheaper hardware in the longterm, and the government-owned software (a sort of closed open source, with a library available to all vendors) would prevent lock-in with a limited set of contractors.

CORBA style

JPEO JTRS is gone, but its software lives on. The Joint Tactical Networking Center (JTNC) has taken over management of the Software Communications Architecture, the application framework and POSIX-based real-time operating system that powers all the software-defined radios birthed from JTRS-descendant communications gear, along with libraries for the various mission-specific “waveforms” used by different radios. SCA provides an interface for software to manipulate the field-programmable gate arrays (FPGAs) in radio hardware to reconfigure how they function. And until recently, those interfaces required radio developers to use the Common Object Request Broker Architecture (CORBA) to access them.