การสร้างแบบจำลองการสูญเสียคลื่นสัญญาณวิทยุ ในเขตพื้นที่เมืองของประเทศไทยโดยใช้สายอากาศชนิดทิศทางเดียว บนเทคโนโลยีการสื่อสารลอร่าแวนสำหรับสมาร์ตมิเตอร์

Abstract

Smart Meter (SM) is a device used to measure electricity consumption. The SM can report power consumption to control center via communication link automatically via wireless communication technologies. LoRaWAN (Long Range Wide Area Network) has been widely used for sensor network included the SM. The antenna is a key componence to indicate an effective communication system. A MicroStrip (MS) antenna works based on unidirectional radiation pattern, which operates at a frequency of 920-925 MHz. Unidirectional pattern increases the efficiency of the communication system by reducing some interference and some noise. The MS antenna is used to design a new Path Loss (PL) model for LoRaWAN in urban areas. The PL model is used to predict the attenuation of signals caused by environmental and distance between transmitter and receiver. The result shows that proposed path loss model is developed by our proposed MS antenna that is more accurately than the traditional path loss model. This thesis proposes a new path loss model for smart meter environment in the urban area of Thailand by using Empirical method and Linear Regression Analysis. The results show the Microstrip antenna performance is work in this environment, when compared to the commercial antenna. In addition, our model can predict the path loss more accurately than the Okumura-Hata model by estimating the Root Mean Square Error (RMSE) and the Coefficient of Determination or R-squared. Keyword: LoRa, LoRaWAN, smart meter, path loss model, empirical model, microstrip antenna, unidirectional antenna, linear regression analysis, urban area