交换式网络利用空分交换结构大大提高了网络的整体通信容量,已成为新一代航空电子系统组网互联的典型手段,可以采用泛化网络演算实施典型组网特性下的机载网络实时性能画像和预测,但缺乏优先级策略下的网络实时性能分析手段。在对机载交换式网络优先级控制策略特征参数抽象化的基础上,利用网络演算理论实施了高低优先级控制的泛化网络演算建模,在突发度包络函数的边界约束下完成了不同优先级流量占比的端到端确界延迟分析,并给出了优先级占比分配方案推荐。在典型机载网络拓扑结构下利用随机生成案例对优先级驱动的泛化网络演算模型进行实验验证。结果表明:相比于采用详细流量配置的演算结果,本文提出的泛化网络演算的有效性超过33%,实现了基于组网特征的机载网络性能预估。
Switching networks make use of the structure of air separation switching to increase the overall communication capacity remarkably, and have therefore become a typical means for interconnecting new generation avionics systems. Generalized network calculus can be used to predict the real-time performance of switching networks according to typical network features. However, generalized network calculus lacks the means to analyze the real-time performance of the networks which distinguish high and low priority. On the basis of abstracting the features of the priority control strategy for switched networks, the priority-driven generalized network calculus models the high and low priority streams using the network calculus theory. Under the boundary constraint of the burst envelope function, the end-to-end delay-bound analysis of different priority proportions is completed, and the priority ratio scheme is given. In the typical airborne network topology, the model proposed is verified experimentally with a randomly generated case. The results show that compared with the calculus using detailed traffic configuration, the calculus proposed is 33% more effective, and can realize performance prediction of airborne switched networks based on network features.
[1] 何锋.机载网络技术基础[M].北京:国防工业出版社, 2018:171-172. HE F. Fundamentals of airborne network[M]. Beijing:National Defense Industry Press, 2018:171-172(in Chinese).
[2] 何锋,周璇,赵长啸,等.航空电子系统机载网络实时性能评价技术[J].北京航空航天大学学报, 2020, 46(4):651-665. HE F, ZHOU X, ZHAO C X, et al. Real-time performance evaluation technology of airborne network for avionics system[J]. Journal of Beijing University of Aeronautics and Astronautics, 2020, 46(4):651-665(in Chinese).
[3] CRUZ R L. A calculus for network delay.I.Network elements in isolation[J]. IEEE Transactions on Information Theory, 1991, 37(1):114-131.
[4] CRUZ R L. A calculus for network delay. II. Network analysis[J]. IEEE Transactions on Information Theory, 1991, 37(1):132-141.
[5] CHARARA H, SCHARBARG J L, ERMONT J, et al. Methods for bounding end-to-end delays on an AFDX network[C]//18th Euromicro Conference on Real-Time Systems (ECRTS'06). Piscataway:IEEE Press, 2006:193-202.
[6] MARTIN S, MINET P. Schedulability analysis of flows scheduled with FIFO:Application to the expedited forwarding class[C]//Proceedings 20th IEEE International Parallel&Distributed Processing Symposium. Piscataway:IEEE Press, 2006:8969806.
[7] LI X T, SCHARBARG J L, FRABOUL C. Analysis of the pessimism of the Trajectory approach for upper bounding end-to-end delay of sporadic flows sharing a switched Ethernet network[C]//19th International Conference on Real-Time and Network Systems. New York:ACM, 2011:149-158.
[8] XIONG Y, HE F, LI X T, et al. Improving the serialisation of Trajectory approach for switched Ethernet network[J]. Electronics Letters, 2017, 53(13):845-847.
[9] TINDELL K, CLARK J. Holistic schedulability analysis for distributed hard real-time systems[J]. Microprocessing and Microprogramming, 1994, 40(2-3):117-134.
[10] GUTIÉRREZ J J, PALENCIA J C, GONZÁLEZ HARBOUR M. Holistic schedulability analysis for multipacket messages in AFDX networks[J]. Real-Time Systems, 2014, 50(2):230-269.
[11] SPURI M. Holistic analysis for deadline scheduled real-time distributed systems[R]. Paris:INRIA, 1996.
[12] LE BOUDEC J Y, THIRAN P. Network calculus:A theory of deterministic queuing systems for the internet[M]. Berlin:Springer-Verlag, 2001:67-75. 132-141.
[13] BAUER H, SCHARBARG J L, FRABOUL C. Improving the worst-case delay analysis of an AFDX network using an optimized trajectory approach[J]. IEEE Transactions on Industrial Informatics, 2010, 6(4):521-533.
[14] TINDELL K W, BURNS A, WELLINGS A J. Allocating hard real-time tasks:an NP-Hard problem made easy[J]. Real-Time Systems, 1992, 4(2):145-165.
[15] GRIEU J. Analyse et évaluation de techniques de commutation Ethernet pour l'interconnexion des systèmes avioniques[D]. Toulouse:Laboratory Space and Aeronautical Telecommunications, 2005.
[16] ZHAO L X, LI Q, XIONG Y, et al. Using multi-link grouping technique to achieve tight latency in network calculus[C]//2013 IEEE/AIAA 32nd Digital Avionics Systems Conference (DASC). Piscataway:IEEE Press, 2013:2E3-1.
[17] LI X T, SCHARBARG J L, FRABOUL C. Improving end-to-end delay upper bounds on an AFDX network by integrating offsets in worst-case analysis[C]//2010 IEEE 15th Conference on Emerging Technologies&Factory Automation. Piscataway:IEEE Press, 2010:11662312.
[18] THIELE L, CHAKRABORTY S, NAEDELE M. Real-time calculus for scheduling hard real-time systems[C]//2000 IEEE International Symposium on Circuits and Systems. Piscataway:IEEE Press, 2000:101-104.
[19] FIDLER M, RECKER S. Conjugate network calculus:A dual approach applying the Legendre transform[J]. Computer Networks, 2006, 50(8):1026-1039.
[20] HE F, LI E S. Deterministic bound for avionics switched networks according to networking features using network calculus[J]. Chinese Journal of Aeronautics, 2017, 30(6):1941-1957.
[21] AN D H, KIM K H, KIM K I. Optimal configuration of virtual links for avionics network systems[J]. International Journal of Aerospace Engineering, 2015, 2015:329820.
[22] YAO M, QIU Z, KWAK K. Leaky bucket algorithms in AFDX[J]. Electronics Letters, 2009, 45(11):543-544.
[23] HE F, ZHAO L, LI E S. Impact analysis of flow shaping in Ethernet-AVB/TSN and AFDX from network calculus and simulation perspective[J]. Sensors (Basel, Switzerland), 2017, 17(5):1181.
[24] DUAN Z, ZHANG Z L, HOU Y T. Fundamental trade-offs in aggregate packet scheduling[J]. IEEE Transactions on Parallel and Distributed Systems, 2005, 16(12):1166-1177.
[25] HUA Y, LIU X. Scheduling design and analysis for end-to-end heterogeneous flows in an avionics network[C]//2011 Proceedings IEEE INFOCOM. Piscataway:IEEE Press, 2011:2417-2425.
[26] HAMZA T, SCHARBARG J L, FRABOUL C. Priority assignment on an avionics switched Ethernet Network (QoS AFDX)[C]//201410th IEEE Workshop on Factory Communication Systems. Piscataway:IEEE Press, 2014:14395068.
[27] SAE INTERNATIONAL. ARINC 664 P7:ARINC specification 664. aircraft data network, parts 7:avionics full-duplex switched ethernet network[S]. Warrendale:SAE International, 2005.
CJA