Análise e Caracterização da Cobertura LoRa para Ambiente Indoor na Frequência de 915 MHz

Abstract

The development of the economy and the increase in productivity and profitability of producers, whether in the manufacturing or agricultural sectors, are directly linked to the use of technology in their production processes. Along with the emergence of the internet, the telecommunications sector has been standing out and enabling the exchange of information in a way that is more accessible to the general public. With the rapid development of new technologies, such as long-distance and low-power communications networks (LPWAN) - LoRa, the technology in question represents a new trend in the evolution of telecommunications, which has been gaining wide acceptance in the world scenario, due to the large signal coverage, small power consumption and low implementation cost. The present work aims to establish the characterization of wireless communication coverage, indoors, in the 915 MHz frequency band. This frequency band was chosen due to its use by communication systems of long-range and low-power networks. with the use of LoRaWAN protocols in Brazil. In this work, a fixed transmission system and a mobile reception system were set up to perform stationary and mobile measurements inside the premises of Block D of the Engineering Building, located on the Praia Vermelha Campus of the Fluminense Federal University, with the aim of characterize the propagation environment inside the building. From the collected data, it was possible to analyze the signal coverage and determine the decay coefficients over distance, as well as the signal penetration losses as a function of the distance covered. The collected data were compared to Friis, Log-Distance and ITU-R P.1238-1 prediction models. Additionally, radio signal coverage analyzes were performed using different configurations in the transmission system, among them, the scattering factors (SF) 7, 9, 10 and 12 and the bandwidths (BW) 125 and 250 kHz.