Cooperative and Efficient Real-Time Scheduling for Automotive Communications

FlexRay is an automotive network communication protocol. It provides support to transmit time-sensitive messages in automobiles. FlexRay transmits periodic messages in a static segment and a periodic messages in a dynamic segment. To improve transmission reliability, FlexRay offers hybrid data management schemes for both static and dynamic segments. However, existing approaches only schedule static segment and dynamic segment separately, leading to poor bandwidth utilization and transmission delay. Moreover, due to the bandwidth limitation, existing best-effort retransmission for all segments fails to achieve high reliability. To address these two concerns, we propose a novel and efficient scheduling scheme, called Coefficient. The idea behind Coefficient is to cooperatively schedule the static and dynamic segments, while judiciously stealing the selective slacks for reliable transmission based on practical fault models. Coefficient schedules both static and dynamic segments in the dual-channel manner based on practical fault models. Extensive experiments based on real-world case studies demonstrate that Coefficient meets the needs of both real-time transmission and reliability requirements, and delivers significant performance improvements.