Comparative Performance Analysis of Empirical Propagation Models for LoRaWAN 868MHz in an Urban Scenario

Empirical propagation models are vital tools for planning and deployment of any wireless communication network as they depend less on terrain data and are faster to execute. In this paper, NS3 is used to simulate radio propagation for Long range wide area network (LoRaWAN) at 868 MHz in an urban environment using the Okumura-Hata model, the COST-231 Hata, and the COST 231 Walfish-Ikegami (COST-WI). LoRaWAN use radio frequency 868 MHz for communication in Europe. The predicted received signal strength values are compared with the real-world measurements taken in the city of Glasgow to analyze the validity and accuracy of the empirical models when used for planning and coverage prediction in LoRaWAN networks. The comparison between models and measurements shows that Okumura-Hata under-estimated the received signal strength in Glasgow city scenario while COST-WI over-estimated the same power. Similarly, the Okumura-Hata model showed higher accurate predictions whereas COST-WI accuracy was the least. The magnitude of mean absolute error indicates how big or small models prediction error can be expected. This study can be used to give an insight into the effectiveness and accuracy of empirical propagation models for evaluation of Internet of Things (IoT) connectivity with LoRaWAN networks in a non-line of sight (NLOS) urban environment.