Developing distributed applications rapidly and reliably using the TENA middleware

The test and training enabling architecture (TENA) middleware is the result of a joint interoperability initiative of the Director, Operational Test and Evaluation (DOT&E) of the Office of the Secretary of Defense (OSD). The goals of the initiative are to enable interoperability among ranges, facilities, and simulations in a quick and cost-efficient manner, and to foster reuse of range assets and future range system developments. The TENA middleware uses Unified Modeling Language (UML)-based model-driven code generation to automatically create a complex Common Object Request Broker Architecture (CORBA) application. This model-driven automatic code-generation greatly reduces the amount of software that must be hand-written and tested. Furthermore, the TENA middleware combines distributed shared memory, anonymous publish-subscribe, and model-driven distributed object-oriented programming paradigms into a single distributed middleware system. This unique combination yields a powerful middleware system that enables its users to rapidly develop sophisticated yet understandable distributed applications. The TENA middleware offers powerful programming abstractions that are not present in CORBA alone and provides a strongly-typed application programmer interface (API) that is much less error-prone than the existing CORBA API. These high-level, easy-to-understand programming abstractions combined with an API designed to reduce programming errors enable users to quickly and correctly express the concepts of their applications. Re-usable standardized objects farther simplify the development of applications. The net result of this combination of features is a significant reduction of application programming errors yielding increased overall reliability and decreased overall development time. Distributed applications developed using the TENA middleware exchange data using the publish-subscribe paradigm. Although many publish-subscribe systems exist, the TENA middleware represents a significant advance in the field due to the many high-level, model-driven programming abstractions it presents to the programmer. The TENA middleware API relies heavily on compile-time type-safety to help ensure reliable behavior at runtime. Careful API design allows a great number of potential errors to be detected at compile-time that might otherwise go unnoticed until run-time - where the cost of an error could be extremely high! The implementation of the TENA middleware uses C++, as well as a real-time CORBA ORB. The TENA middleware is currently in use at dozens of Department of Defense (DoD) testing and training range facilities across the county and has been used to support major test and training events such as Joint Red Flag '05. The TENA Middleware is available at http://www.tena-sda.org/