A performance study of Audio Video Bridging in aeronautic Ethernet networks

Audio-Video-Bridging (AVB) is a promising new commercially available Ethernet-based standard providing mechanism for audio and video transmission over Ethernet supporting demanding audio and video transmission delay requirements. This paper addresses the applicability of using AVB in a fully-switched Ethernet network that covers safety-related functions in the aeronautics. Avionic systems leveraging such digital networks have stringent requirements in terms of audio quality, latency, and jitter; e.g., latency can be at most a few milliseconds. The result of this work is a performance study of audio transmission approaches in aeronautics where we address AVB without synchronization and AVB synchronization with 802.1AS. We pay special attention to the failure mode of losing synchronization during operation. Two real-world scenarios are addressed in the experimental results - a demonstration of a switched Ethernet aircraft cabin and a demonstration for a highly safety-related audio system. For these two scenarios hard performance bounds are required in terms of synchronous playback that cannot easily be fulfilled, especially when time synchronization is lost.