BEB算法的不同退避阶段站点分布概率模型

BEB algorithm model of the probability distribution for the terminal in different backoff stages

在采用二进制指数退避(BEB)算法的CSMA/CA协议中,针对网络性能随网络规模变化的特性,提出了一种新的网络冲突率分析模型.该模型将网络中的传输站点建立成一个整体的排队网络服务模式,考虑了退避算法中退避次数限制、延时侦测等机制.基于该模型详细地分析了站点在退避计时器结束后,争夺传输时隙的访问方式,推导出网络冲突率的表达式.以此为基础,论证了网络传输的稳定状态的存在性,以及站点在不同退避阶段的分布情况.仿真实验结果验证了分析该模型的有效性.

In the CSMA/CA protocol using the binary exponential backoff algorithm, an effective analytical model of the network collision is proposed for the characteristics of transmission performance with the scale of networks changing. The mechanism for the retry limit of backoff and delay detection is considered, and the whole pattern of queueing networks service for terminals is established in the network, on the basis of which the media access mechanism of the terminal contending for transmission time slot is analyzed after the backoff counter reset, and the expression rate of the network conflict is derived. The model demonstrates the steady state of network transmission, and the probability distributions for the terminal in different backoff stages. Simulation results indicate that the model and the analysis are very effective.