Wireless channel characterisation for IEEE 802.15.4 in railroad scenario

Abstract

In a train monitoring system, the sensor data measured at the train wheel, near the axle needs to be transmitted to a receiver located within the passenger car. The condition of the wireless channel from the outside to the inside of the train is critical because there are several metal parts between the transmitter and receiver. In addition, the channel variation characteristics change according to the area in which the train is driven. Hence, analyses of the wireless channel conditions are important for the successful transmission of the sensed data. Here, the channel profiles are estimated based on the data measured during various driving scenarios. The channel variation statistics are characterised by a probability function with certain key wireless channel parameters. In all the scenarios, the extreme value distribution in the dB scale is well matched with the channel statistics. A practical research of a railroad wireless sensor network is presented in this Letter and it is expected to be the basis for further simulation studies.