Design And Implementation Of Time-Triggered Ethernet Time Schedule Generation Software

With the rapid development of aerospace industry and computer information technology,the avionics system gradually evolves to the distributed integrated modular architecture.This architecture brings higher and higher requirements to the real-time,reliability,compatibility and data transmission rate of network communication.Traditional Ethernet is no longer able to meet these new demands,thus Time-Triggered Ethernet(TTE)is Triggered.TTE has introduced time trigger mechanism,clock synchronization mechanism and fault tolerance mechanism,and is compatible with traditional Ethernet technology,which is expected to be an ideal interconnection infrastructure in the future.However,TTE does not specify the algorithm for scheduling time-triggered business,and the schedule mechanism needs to be customized according to the network topology and business flow.Based on the business type and schedule principle of time-triggered Ethernet,this paper proposes a time schedule generation algorithm which makes the delay of time-triggered service very small and the network link utilization very high.Besides,time schedule generation software for TTE network is also designed and implemented in this paper.This paper first introduces the research background,characteristics and applications of TTE network,as well as the research status of the algorithm for the generation of time schedule.Secondly,the system structure,business types and schedulie principles of different types of businesses of TTE network are analyzed.Thirdly,the functional requirements of TTE time schedule generation software are analyzed and the overall structure of TTE scheduling timetable generation software is designed.Fourthly,this paper introduces the basic concept of time schedule and proposes a TTE time schedule generation algorithm.The design idea,algorithm steps and programming realization of the algorithm in pure unicast network,multicast support network,gigabit mixed rate port network and compatible network are described in detail.Fifthly,The TTE time schedule generation software is designed and implemented.The design idea,operation mode and programming realization of main interface and each functional unit are mainly introduced.Sixthly,the generation algorithm of TTE schedule table is simulated and verified by the real network environment,which shows that it meets the functional and performance requirements of the schedule.This paper has the following innovations: first,an algorithm for the generation of TTE time schedule is proposed.In the algorithm,the service time of time-triggered service is allocated as close as possible to the time when it is generated.The maximum port matching algorithm is also adopted which give the priority to the time-triggered service with the minimum indegree inport and the maxminm out-degree outport to get allocated.In this way,there are as many services as possible being transmitted without conflict at the same time which reduces the total time delay of time-triggered services and improves the link utilization.The algorithm designed in this paper can provide schedule services under various scenarios including unicast network,multicast support network,gigabit port network and compatible network.Second,TTE network dedicated time schedule generation software is designed and implemented.The problems of complex configuration,tedious and error-prone generation process,and the need to customize the scheduling algorithm according to the actual situation are solved.The software can be directly applied to practical engineering,which is of great significance for promoting theoretical research and independent development of key technologies and products in TTE network.