Impact of source scheduling on end-to-end latencies in a QoS-aware avionics network.

This paper investigates the impact of a novel source scheduling framework tailored to introduce Quality of Service (QoS) in legacy embedded avionics networks. The protocol of interest is the Avionics Full Duplex Switched Ethernet (AFDX) deployed in modern civilian aircrafts to handle the transmission of time-critical avionics flows. Our aim is to introduce soft real-time flows on such networks in order to carry video flows. Multiplexing avionics real-time flows with video flows is tackled by introducing table scheduling at the end systems (i.e. transmitters). We propose herein a solution that preserves the worst-case end-to-end delay of avionics flows, and show how their scheduling in the table impacts the jitter of the video flows. Thorough simulations on a A350-like network architecture underline that table schedules mostly impact the jitter of video flows at the source and have limited impact on the jitter introduced by the network transfer.