The NASA Glenn Research Center has released an open architecture framework for space-based software-defined radios. The Space Telecommunication Radio System (STRS) architecture description and standard provides a standard framework for future NASA space radios with greater degrees of interoperability and flexibility to meet new mission requirements. The goal is to improve capability by using this common standard across NASA missions and services. An open architecture reduces system development and operation costs by promoting and enabling multiple vendor solutions and interoperability between independent hardware and software technologies. The architecture supports existing communications needs and capabilities while providing a path to more capable, advanced waveform development and mission concepts. It provides an effective approach to designing and utilizing communications systems; radios are designed, managed, and operated through the adoption of common standards.
The architecture effort defined the components and rule set framework for both software and hardware architectures. A key concept was the reuse of previously developed hardware and software components. The ability to reuse components was accomplished by defining the various hardware and software interfaces and providing additional layers to the architecture to abstract the software from the platform hardware. Because these interfaces are specified consistently and published as part of the architecture specification, and because rules are provided for each component, the various modules can be replaced and updated with a minimum amount of changes.
STRS software architecture. API, application programming interface; POSIX, Portable Operating System Interface.
Long description of figure 1.
STRS hardware architecture. RF, radiofrequency; TT&C, Telemetry, Tracking, and Control; HAL, Hardware Abstraction Layer.
Long description of figure 2.
The software architecture provides a framework for the resulting software components. It describes the functions of each software component, the interfaces between components, and the services used to communicate with the underlying hardware. The layer between the waveform application and the operating environment is a key concept for the STRS architecture. Development of this layer required a careful balance to keep the operating environment from overwhelming the processing requirements of the radio, especially for the space environment. Minimizing the required resources of the operating environment (e.g., power and mass) for the constrained space case is important because the radiation-hardened electronics used in the radios will lag at least a generation or two in processing capability from commercial equivalents. The approach was to identify the core interfaces to provide application software (e.g., waveforms) development flexibility and portability by standardizing the interface provided by the radio processing platform through standard services.
The architecture provides an initial description of the functionality and interfaces of the software-defined radio system. Instead of a static description, it provides a framework that will evolve over time as technologies mature. This year, Glenn released the STRS Architecture Description Document, and it was reviewed by experts from different NASA centers. An industry day was held to solicit comments from those developing and/or integrating radios for NASA, the Department of Defense, and commercial space applications. These comments are being incorporated into the architecture, and future work will improve the architecture so that it can be recommended as an Agency standard.
Reinhart, Richard C.; Farrington, Allen; and Israel, Dave: Space Telecommunications Radio System STRS Open Architecture Description, Rev. 1.0, Space Operations Mission Directorate, Apr. 2006. Available from NASA Glenn Research Center’s Digital Communications Branch.
Reinhart, Richard C.; Farrington, Allen; and Israel, Dave: Space Telecommunications Radio System STRS Open Architecture Standard, Rev. 1.0, Space Operations Mission Directorate, Apr. 2006. Available from NASA Glenn Research Center’s Digital Communications Branch.
ZIN Technologies, Inc., contact: Thomas J. Kacpura, 216-925-1266, Thomas.J.Kacpura@nasa.govLast updated: September 7, 2007
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