An Efficient Scheduling Algorithm for Adjustable Time Slots in Time-Triggered Ethernet

When a network scale for the traditional Ethernet is continuously expanded, an increase of the number of network hops will result in an augment of waiting delay uncertainty for a service transmission, which makes the network inefficiency and difficult to guarantee service quality. The time-triggered Ethernet adopts the global time synchronization and time triggering mechanism to ensure the service quality of high-priority services such as spaceflight tracking telemetry and control, network security, and vital signs monitoring, which possesses broad applications in aerospace, medical aid, and vehicle network. Currently, the time-triggered Ethernet triggers a time-triggered stream by employing an offline generated scheduling schedule, and is difficult to adapt to dynamic changes of a network, which leads to the network rigidity and inefficiency. Therefore, this paper proposes an algorithm for generating time-triggered schedules that can adjust time slots, flexibly. The time-triggered Ethernet prototype system is designed by utilizing the TrueTime, and the process of generating the scheduling table to trigger the time-triggered stream is simulated. Compared with the existing traditional algorithm, our algorithm can adjust the time slots according to the ratio of time-triggered streams to traditional traffic in the network, which can improve the time utilization rate by 30%.