What is the SCA?

The Software Communications Architecture (SCA) is an open architecture framework that promotes development of “Software Defined” systems by clearly identifying the boundaries for software applications and their interactions with the physical hardware. The SCA facilitates the portability, interoperability and configurability of the software and hardware components used in embedded systems.

The SCA was originally developed by the U.S. military’s Joint Tactical Radio Systems (JTRS) to standardize the way in which Software Defined Radios (SDR) for the U.S. armed forces were to be built. Since then, the SCA has evolved with the input of the international radio community led by the Wireless Innovation Forum (WInnF).

The SCA follows a Component Based Development (CBD) paradigm where software applications (i.e., waveform applications) are assembled using a number of individually built (and tested) components. The SCA is a CBD architecture that provides location transparency as well as operating system and programming language independence for its software components. Being a key goal of the SCA to promote software reuse, application components are ‘shielded’ on their interaction with the physical hardware through an abstraction layer that offers standardized interfaces as proxies to the physical hardware. The latter in turn promotes application portability from one platform to another.

The SCA Core Framework (CF), a key element of the architecture, provides a standard operating (OE) that is identified by the combination of Operating System (OS), Processor and CORBA ORB for inter process communication. The SCA CF is a runtime deployment engine that identifies requirements of software components, and matches them with suitable targets for deployment within the SCA system. Requirements can take the form of capabilities of a platform like processor type (GPP, DSP, GPU, FPGA), or finite capacities like memory or mips needed for execution.

The SCA OE shields the SCA Application from changes in the underlying software/hardware by abstracting the deployment platform. The SCA does so for the physical hardware devices used by the SCA Application, the operating systems that runs on the target, as well as the inter process communication mechanism used by the different components executing on the platform.