摘要
CSMA/CD协议作为以太网重要的MAC层接入控制协议,在工业控制网络中仍得到广泛应用.针对学生在理解网络协议的工作原理时感觉较难的问题,对CSMA/CD及二进制指数回退算法进行建模和分析,并通过MATALB对CSMA/CD协议进行仿真.通过Markov模型分析了二进制指数回退算法的性能,得出了CSMA/CD的理论吞吐量,在MATLAB环境下,对用户节点数、物理层数据速率对信道利用率的影响进行了仿真,仿真结果表明,由于帧间间隙的存在及网络回环时间的约束,用户节点数越多、物理层速率越高,信道利用率越低.
As an important MAC layer access control protocol, CSMA/CD protocol is widely used in industrial control network. The model of CSMA/CD and binary exponential backoff algorithm is analyzed, and CSMA/CD protocol is simulated using MATLAB, in view of the difficulty found among students in understanding the principle of network protocol. The per- formance of the binary exponential backoff algorithm is analyzed through Markov model, and the theoretical throughput of CS- MA/CD is derived. Under the MATLAB environment, the throughput of channel versus user node number, physical layer data rate is simulated. Simulation results show that the channel utilization rate is lower~ the user number of nodes is larger and physical layer rate is higher due to the inter-frame slot and the network loopback time constraints.
出处
《内江师范学院学报》
2015年第12期14-20,共7页
Journal of Neijiang Normal University
基金
四川省教育厅科研项目(13ZA0005)
内江师范学院项目(JG201220-215
SJ14001)
