In the paper we can learn description like propagation delay, runtime measurement, error sources, the computation time, frequency, measurement method, and time measurements. The paper tells you info like signal, range, measurements, measurement system, transceiver, microcontroller, and synchronization.
Lots of explanation like radio transceivers, distance measurement, sensor networks, accuracy, wireless sensor networks, range measurements, and computation time are presented in the paper. Below are taken from the paper:
Hardware Limitations To measure the TOF of a radio packet we utilize the last bit of sync word pin of the transceiver chip to start a measurement on an outgoing packet and the same pin to stop the measurement on an incoming packet as described in section II-C. The measured RTT Rt is estimated as follows: Rt = Jt0 + Jc0 + T OF R + T OF A + Jt3 + Jc3 (7) In (7) T OF R is the TOF for the request packet and T OF A is the TOF for the answer packet.
Additionally, the paper contains more things like error, sensor, wireless sensor, signal processing, distance, and computation.