Comparative analysis of magnetic induction based communication techniques for wireless underground sensor networks

A large range of applications have been identified based upon the communication of,underground sensors deeply buried in the soil. The classical electromagnetic wave,(EM) approach, which works well for terrestrial communication in air medium,,when applied for this underground communication, suffers from significant,challenges attributing to signal absorption by rocks, soil, or water contents, highly,varying channel condition caused by soil characteristics, and requirement of big,antennas. As a strong alternative of EM, various magnetic induction (MI) techniques,have been introduced. These techniques basically depend upon the magnetic,induction between two coupled coils associated with transceiver sensor nodes.,This paper elaborates on three basic MI communication mechanisms i.e. direct MI,transmission, MI waveguide transmission, and 3D coil MI communication with,detailed discussion of their working mechanism, advantages and limitations.