Evaluation of the Transient EM Interferences Impact on the Clear Channel Assessment in Wi-Fi Communications

This paper presents a study about transient electromagnetic (EM) interferences produced by contact losses between the catenary and the pantograph and their impact on the Internet access on board trains. This study is focused on the assessment of the impact of these transient EM interferences on the Clear Channel Assessment (CCA) mechanism used in the Wi-Fi protocol. A series of tests was carried out to analyze the effects of the transient EM interferences on the Wi-Fi communication bit rate. The results reveal the relation between the parameters of CCA mechanism and the characteristics of the transient interferences, then explaining the degradation of the achieved bit rate.