Imagine a radio technology that could configure a wireless device to work with any communications system, be it a cellular phone, a pager, a WI-FI transceiver, an FM or AM radio, a satellite communications terminal and even a garage door opener. This would offer both cost and time savings for consumers, who would only need to buy one radio to meet multiple communications needs. And more importantly, that same technology could facilitate interoperability among the communications systems used by military, police and rescue-relief teams, who currently cannot always communicate with each other, even sometimes in critical, life-threatening situations because of incompatible radio systems.

This unique radio technology is called Software Defined Radio (SDR) and it works much like desktop computing, where a single hardware platform can carry out many functions based on the software applications loaded. SDR uses software to perform radio-signal processing functions instead of using resistors, capacitors, feedback loops, or application-specific integrated circuits. Frequency tuning, filtering, synchronization, encoding and modulation are now performed in software on high-speed reprogrammable devices such as digital signal processors (DSP), field programmable field array (FPGA), or general purpose processors (GPP). RF components are still needed for generation of high frequencies or for signal amplifications and radiation but SDR aims at reducing the count to a minimum.

The technology is being promoted by the US Department of Defence to replace tens of thousands of single protocol, single use radios with a common platform that could be reprogrammed to ensure interoperability. Military and public safety organizations from around the world are also considering this technology to solve their interoperability problems. The Software Defined Radio Forum (SDRF) is also promoting the technology but for commercial applications.

At the center of this new technology is the software architecture on which the radios must be built and communication protocols implemented. Many proprietary architectures exist, but to ensure portability and interoperability of the protocols on the different radios, an open architecture had to be developed. The Software Communications Architecture (SCA) is such an architecture. The SCA is a set of specifications describing the interaction between the different software and hardware components of a radio and providing software commands for their control. The SCA has been developed by the U.S. Department of Defense Joint Tactical Radio System (JTRS) project, adopted by the Software Defined Radio Forum (SDRF).

Early adopter of the Software Communications Architecture (SCA), CRC's Advanced Radio System group (RARS) has been involved in the evolution and adaptation of the specification. In collaboration with Defence Research & Development Canada (DRDC), CRC has made ongoing contributions to its development:

• Pioneered the use of a dynamic loader for DSP environments and the use of SCA CORBA adapters
• Developed and tested an SCA-enabled radio demonstrator, supporting a DSP-based implementation
• Released on its web site, an open source reference implementation of the SCA (project SCARI-OPEN sponsored by the SDRF).
• Submitted over 20 change proposals to the JTRS/Joint Program Office to enhance the SCA specifications
• Carried out the first public demonstration of a commercial SCA-enabled waveform, a Digital Audio Broadcast (DAB) waveform

Today, CRC's Advanced Radio System group (RARS) offers a number of products and services for the development of SDR technology. For more information, please visit our Products and Technical Services sections or download the SCARI Software Suite brochure HTML |  PDF.