Assessing the Quality of Radio Coverage of the NB-IoT Network Based on RSRP Signal Level Measurements

Assessing the quality of NB-IoT network covered by the telecom “Mobile TeleSystems” company in Astrakhan, Russia was carried out. The quality was evaluated in terms of the received signal strength (RSRP). The highlights of NB-IoT standard measurements obtained from the NB-IoT TESTER RB-NBT1 device are presented. Measures were conducted in a new residential building from the 2nd to the 18th floor at the locations of smart utility meters. It simulates a scenario involving the use of smart meters with NB-IoT technology support. Logarithmic approximation equations, cubic polynomial approximation formulas, and piecewise linear interpolation of RSRP parameter measurement data related to building floor levels were created. It was founded that 18-story residential building has stable radio coverage of the NB-IoT network, which is ensured by the RSRP signal level exceeding the sensitivity the measuring device near -140 dBm by at least $\mathbf{3 0 - 3 5 ~ d B}$. It guarantees the reliability of IoT service in this area.