The NASA Glenn Research Center, along with General Dynamics Decision Systems, has defined an open-architecture framework for space-based software-defined radios. Software-defined radio is a collection of hardware and software technologies that enable reconfigurable system architectures for wireless networks and user terminals. Software-defined radio enables multi-band, multifunctional wireless devices that can be dynamically enhanced by software upgrades. They include technologies that are applicable across a wide range of wireless use. Software-enabled devices and equipment can be dynamically programmed to reconfigure the characteristics of radio equipment.
The framework developed by Glenn and General Dynamics consists of an architecture structure, the associated waveform parameters, and interface descriptions. Elements of software-defined radios are divided into different layers representing the hardware and software portions of the radio system. Open architectures allow technology insertion at certain layers without affecting other layers as technology changes and improves. Layering promotes and enables multiple vendor solutions and interoperability between independent hardware and software technologies.
This new architecture allows for flexibility and change and promotes the sharing and integration of software from a variety of sources. Software portability and design reuse play significant roles in containing the cost of software-defined radio developments. An open-architecture software design enables the separation of software from hardware, enabling the software to be ported to future platforms. The ability to reuse components is accomplished by defining various hardware and software interfaces and by defining the layers of the architecture framework to abstract the software from the hardware. By consistently specifying these interfaces and publishing them as part of the architecture, various hardware and software modules can be replaced and updated with a minimum amount of changes, since the interface is specified and rules are provided for each component.
Layered elements of an open architecture for software-defined radio.
Long description of figure.
A radio runs applications referred to as “waveforms” that include all the functions necessary to transmit information from one radio to another. The figure illustrates an example of the software abstraction definition between the waveform application and the radio operating environment. The application programming interface layer just below the waveform includes both a uniquely defined set of interfaces and an Institute of Electrical and Electronics Engineers, Inc. (IEEE), standard subset of the Portable Operating System Interface (POSIX) between the waveform applications and the radio’s operating environment. The hardware abstraction layer and the associated lower-level software elements abstract the hardware from the operating system and software infrastructure. The architecture framework requires that vendors publish a hardware interface definition to provide a physical definition of the hardware interfaces for subsequent module integration.
The architecture development at Glenn is part of a larger NASA effort to develop a common radio architecture. Beginning with the baseline architecture, future work will evolve the architecture as it is applied to specific mission cases and will continue to leverage the Joint Tactical Radio System’s Software Communications Architecture, a Department of Defense software radio architecture that was analyzed during this architecture development effort. The new architecture is intended to enable greater interoperability, to reduce cost through software reuse, and to minimize spacecraft resources (e.g., by combining radio functions to reduce radio count) as the architecture provides enhanced operations.
Johnson, Sandra K.; Kacpura, Thomas J.; and Reinhart, Richard C.: Software-Defined Radio Technology Analyzed for Space Exploration Scenario. Research & Technology 2005, NASA/TM--2006-214016, 2006, p. 19. http://www.grc.nasa.gov/WWW/RT/2005/RC/RCD-reinhart2.html
Kacpura, Thomas J.; Reinhart, Richard C.; and Johnson, Sandra K.: Reconfigurable, Software-Defined Waveform Developed on the Basis of the Software Communications Architecture. Research & Technology 2005, NASA/TM--2006-214016, 2006, pp. 20-21. http://www.grc.nasa.gov/WWW/RT/2005/RC/RCD-reinhart3.html
Last updated: October 12, 2006
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