Theoretical models for underwater RFID

Abstract

Underwater wireless communications pose challenges due to the characteristics of water as a propagation channel medium. Regardless, it is needed for a range of systems that operate underwater. Commonly used technologies for these use cases (radio-frequency, acoustic and optical communications) are lacking, as they usually suffer from strong attenuation, multipath and propagation delays. In this context, we explore Radio Frequency Identification (RFID) systems underwater and the feasibility of their application. This paper aims to discuss the theoretical transmission models for RFID systems underwater, separating them into near-field systems -- which use Magnetic Induction (MI) to communicate -- and far-field systems -- that transfer data via Radio Frequency (RF). We determine the path loss for each case, explore its value for different system configurations and present preliminary measurements of magnetic field strength