Using network calculus on worst-case latency analysis for TTEthernet in preemption transmission mode

Time-Triggered Ethernet (TTEthernet) improved from Avionics Full Duplex Switched Ethernet (AFDX) is supposed to enhance the determination by introducing time-triggered mechanism, while indeterminacy problem still exists in rate-constrained (RC) flows thus requiring worst-case latency analysis. Traditional network calculus model used for AFDX is not suitable for TTEthernet due to time-triggered (TT) flow mandatory competition for network resource. In this paper, we derive formula of traffic delay for RC flows in TTEthernet with intensive TT-schedule schema under the condition of preemption transmission mode, expand performance analysis scope to support multi-priority flows through assuming TT flow as the highest-priority RC flow when considering the pessimism of scheduling and verify the practicability of modified model by calculating its algorithmic complexity. Experiments show that our model gives effective latency upper bound which is slightly beyond exact value but no more than 16.7% and sustains rapid calculation for a real complicated network configuration within 3 seconds compared with other existing models.