A Revised Trajectory Approach for the Worst-Case Delay Analysis of an AFDX Network

Xueqian Tang,Guangshan Lu,Qiao Li,Huagang Xiong

doi:10.1109/access.2019.2943543

Abstract

AFDX (Avionics Full-Duplex Switched Ethernet) standardized as ARINC 664 is a major upgrade for safety-critical applications in avionics systems. Worst-case delay analysis of all the flows transmitted on the AFDX network is mandatory for certification reasons. Different approaches have been proposed for end-to-end (ETE) delay upper bound, such as network calculus and trajectory approach, but these methods still introduce some pessimism in the computations and overestimate the exact worst-case delay of the flows. In addition, the existing trajectory approaches may underestimate the exact worst-case delay of the flows for some corner cases. In this article, we revised the trajectory approach to make the flow analysis more accurate for the computation of the worst-case ETE delay. The results had been shown that the worst-case delay analysis of an AFDX network can be improved by using our revised trajectory approach.

Highlights

The distributed real-time systems have widely spread in many domains, such as industrial automation and telecommunication, and their increasingly widespread use leads to a growing number of embedded functions, involving an exponential increase of exchanged data and connections [1]
The contribution of this paper is to propose a revised trajectory approach (RTA) for computing ETE delays in an Avionics Full-Duplex Switched Ethernet (AFDX) network
The worst-case ETE delay computed with network calculus (NC), FA [1] and RTA are presented in Table. 3 and Fig. 10

Summary

INTRODUCTION

The distributed real-time systems have widely spread in many domains, such as industrial automation and telecommunication, and their increasingly widespread use leads to a growing number of embedded functions, involving an exponential increase of exchanged data and connections [1]. AFDX still exists the indeterminism problem which requires worst-case latency analysis, as guaranteed upper bounds of end-to-end (ETE) delays for messages transmitted over an AFDX network are mandatory for certification reasons. Even though upper bounds are sufficient for certification purposes, The associate editor coordinating the review of this manuscript and approving it for publication was Nan Zhao They often imply overestimation when used for network dimensioning. The contribution of this paper is to propose a revised trajectory approach (RTA) for computing ETE delays in an AFDX network. It can reduce some overestimation ( called pessimism) in the computations and deal with the underestimation ( called optimism) problem, and improve the worst-case end-to-end delay upper bound of the flows.

RELATED WORK AND MOTIVATIONS

COMPARED WITH CTA AND OTA

Findings

CONCLUSION