This survey paper describes WSNs for railway condition
monitoring focusing on systems described in the academic
literature. In this survey, “sensor” refers to an individual device
such as an accelerometer or strain gauge. “Node” refers to a
whole sensor unit that comprises the sensor, a power supply,
a data transmitter/receiver, and a microcontroller. Section II of
the survey discusses the design and range of sensor devices,
Section III analyzes the network topology and transmission
techniques, and Section IV reviews the sensors used in the literature
to monitor railway equipment and structures. Section V
draws conclusions, and Section VI examines future work in the
area of railway monitoring.