Testing Deterministic Avionics Networks Using Orthogonal Arrays

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Thesis Type: Postgraduate

Institution Of The Thesis: Yildiz Technical University, Graduate School of Natural and Applied Sciences, Avionic Engineering, Turkey

Approval Date: 2022

Thesis Language: English

Student: Muhammed Efe Altuntaş

Principal Supervisor (For Co-Supervisor Theses): Erhan Akdoğan

Co-Supervisor: İbrahim Hökelek

Open Archive Collection: AVESIS Open Access Collection

Abstract:

The Integrated Modular Avionics (IMA) concept has become popular to meet the increasing requirements of next-generation aircraft. Ethernet-based deterministic network (DTN) protocols have been developed for the IMA concept. ARINC 664 which is DTN protocol, provides end-to-end communication with bounded latency and jitter for safety-critical applications in avionics systems. Existing certification requirements for equipment to be used on aircraft determine the design assurance levels (DAL) based on the equipment's criticality levels. Due to the safety criticality in the DTN, it is characterized as DAL A, which means the highest criticality. Therefore, a test bed should be prepared that includes all possible scenarios when using a deterministic network. However, It is not achievable to generate a test suite with a feasible size without employing a formal design of experiment method such as orthogonal arrays (OAs) if we consider all possible combinations of DTN switch configuration parameters such as the number of virtual links (VLs), the frame size, and bandwidth allocation gap for each connection. Because the basic logic of the orthogonal array is to obtain all pairwise combinations once and obtain a subsystem that will cover the entire test space. Using OAs is not sufficient to generate test cases representing real-life usage of DTN switches since many combinations of VL parameters may be inadvertently eliminated by the OA generation process. In this thesis, we present an approach, called \emph{chained OAs}, where multiple applications of OAs are applied to the test factors to generate test cases that are representative of real-life usage of DTN switches. The test cases are converted into executable test scripts to be run by the commercial test system. This study shows that chained OAs method is capable of reducing prohibitively large number of tests required for complex systems, while covering pair-wise combinations of all test parameters.