TCN 协议分析装置丢包率研究

摘要

The paper concludes that reducing packet loss rate of the Train -Communication -Network Protocol Analyzer(TPA)is focused on decreasing the total time of transmitting a data packet from WTB (or MVB)board to PC through analyzing the packet loss reason for TPA.Regarding the minimum packet loss rate as the objective function,and treating the delay of timeout detection,the extra time of transmitting a data packet,and the com-munication load rate of bus as constrained condition,the paper establishes math model of the packet loss rate for TPA and calculates the constrained areas of each control parameter.This model can also design TPA from the points of communication -board hardware,software of CPU board and man -machine interface.Simulation re-sults verify that the setting of constrained areas is reasonable and the establishment of model is correct.Experi-mental tests show that TPA doesn’t lose data package under the condition of full communication load,and those meet the design requirements.%通过分析列车通信网络协议分析装置（TPA）的丢包原因，得出减小 TPA 丢包率的研究重点在于减小从 WTB（或MVB）板到 PC 机传输一个数据包消耗的总时间。进而以最小丢包率为目标函数，以超时检测的延时、传输一个数据包额外花费的时间和总线的通信负载率为约束条件，建立描述 TPA 丢包率的数学模型，得到各个控制参量的约束区间。从通信板硬件、CPU 板软件和人机接口软件等层面进行 TPA 设计。仿真结果验证了约束区间设置的合理性和模型建立的正确性；实验测试表明：TPA 在通信满负载的条件下不丢包，达到设计要求。