Aerospace systems are increasingly dependent upon software for their functionality, with associated software spanning a wide range of application domains. These include aircraft and spacecraft flight controls, mission computing, weapons management, command and control, surveillance, sensor management and processing, telemetry, and more. Understanding of their unique challenges has driven technology development on many fronts associated both with the products - such as real-time component-based application frameworks, supporting middleware, and algorithms - and the processes and tools by which they are created - such as model-based development and integration, automated code generation, simulations, and desktop test environments. This paper describes a number of these domains and challenges, future directions associated with networking and systems of systems, and technologies facilitating their development within The Boeing Company.

As embedded systems increase in complexity and begin to participate in distributed systems, the need for middleware in building such systems becomes imperative. However, the use of middleware that fully implements such standards can impose a significant increase in footprint for an application, making it unsuitable for use in embedded systems. We consider the use of a standard CORBA event channel in a setting where distribution and inter-language support are unnecessary. We report our experience in applying aspects to abstract the transport layer (CORBA) of the event channel into a selectable feature. Thus, enabling or disabling CORBA for a specific application can be decided at build-time, by merely selecting CORBA as a feature. We describe the patterns used to achieve this abstraction and present footprint and throughput results showing the effect of CORBA on automatically derived subsets of the event channel.

Many of the benefits of Java, including its inherent portability, networking support, and simplicity, are of increasing importance to large-scale distributed real-time embedded (DRE) systems, but have been unavailable due to the lack of acceptable real-time performance. Recent work establishing the real-time specification for Java (RTSJ) based on Bollella et al. (2000) has led to the emergence of associated real-time Java virtual machines (RT JVMs) which promise to bridge this gap. This paper describes benchmarking results on a RT JVM in a uni-processing environment, and compares them to both C++ implementations of similar behavior and application requirements associated with large-scale avionics systems. This paper extends previously published results by Corsaro et al. (2002) and Sharp et al. (2003) by including avionics application level tests.

Reusable product line software architectures and supporting components are the focus of an increasing number of software organizations attempting to reduce software costs. One essential attribute of a product line architecture is that it effectively isolates the logical, or static, aspects of the application from any product specific variations in the physical architecture or execution environment. A primary element of this isolation is hardware and low-level software (e.g., operating system) independence. This paper describes our experiences on developing object-oriented physical architectures for large scale reusable embedded systems, and on various ways that physical architecture attributes can be designed for flexibility without introducing volatility into the application architecture.