A study on relationship, effects and interactions between power level and received signal strength of 2.45 GHz embedded active integrated RFID system for real-time monitoring utilizing wireless sensor network platform

This paper presents part of a study of the embedment of the proposed 2.45 GHz active integrated Radio Frequency Identification (RFID) system with Global Positioning System (GPS) receiver and Global System Mobile (GSM) modem. The relationship between distance, power level and received signal strength (RSS) of the proposed embedded active RFID system is compared with the non-embedded active RFID system and focused on a method based on the RSS value to estimate the distance between reader, routers and tags. The proposed active RFID system contains a modified active RFID reader and embedded active RFID tag is successfully developed with implementation of switching mechanism protocol between indoor and outdoor location as well. The design of experiments (DoE) is implemented as a method of measurement and the statistical method is used to evaluate the uncertainty and the relationship between power level and received signal strength of the proposed embedded active RFID system with the non-embedded active RFID system at a specified range. The experimental measurements were conducted for the proposed embedded active RFID system and non-embedded active RFID system in a single hop communication in an indoor environment with line of sight (LOS) direction. The results show that the RSS increases with increasing of power level as stated in propagation theory, however the RSS values for the proposed embedded active RFID system is better than the non-embedded RFID system at all power levels, which further concluded that the proposed embedded active RFID system design is better than the non-embedded active RFID design.