Time-accurate Middleware for the Virtualization of Communication Protocols

TL;DR

This paper presents a time-accurate middleware for virtualizing avionics communication protocols like AFDX, enabling reliable simulation-based testing to replace costly physical tests.

Contribution

It introduces formal models and a prototype middleware for AFDX protocol virtualization that ensures temporal accuracy in simulations.

Findings

Formal models accurately capture AFDX temporal constraints

Middleware enables reliable virtual testing of communication protocols

Runtime monitors verify time-accuracy of middleware behavior

Abstract

Communication between devices in avionics systems must be predictable and deterministic, and data must be delivered reliably. To help the system architects comply with these requirements, network protocol standards like ARINC 429 and AFDX were created. Even though the behaviour of each component in a network is well defined, it is still necessary to test extensively every applications before deployment. But physical test benches used in the aircraft development process are complex and expensive platforms. In order to limit the need for physical tests, we propose a time-accurate middleware for virtualizing communication protocols that can be used to replace physical tests with simulations. We specified three formal models of AFDX networks that take into account temporal constraints with different levels of precision. We also developed a prototype for a network virtualization middleware based on the AFDX protocol specification that provides an easy-to-setup environment for testing network configurations. Finally, we used formal models together with virtualization in order to define runtime monitors for checking whether the behavior of the middleware is time-accurate with respect to a real system.