Modeling and quantitative real-time analysis of Ethernet based on CSMA/CD

The communication delay uncertainty of Ethernet has become a major obstacle in application on industrial control. To solve the problem, it´s very important to exactly model and carry out quantitative research on the real-time performance of Ethernet. This paper proposes a new solution to accomplish the modeling of Ethernet based on CSMA/CD media access method and Binary Exponential Back-up algorithm, especially giving the accurate calculation formula of the net collisions adopting the multiple integrals method. On the basis of this model, some evaluation indexes including collision probability, failure probability and average time for a failure are selected to complete the quantitative analysis on Ethernet with different number of stations. Moreover, the paper comparatively studies the influence of the different network parameters on the Ethernet real-time performance. Finally, the correctness of the mathematical model is verified by the MATLAB simulation.