Molecular Versus Electromagnetic Wave Propagation Loss in Macro-Scale Environments

Molecular communications (MC) has been studied as a bio-inspired information carrier for micro-scale and nano-scale environments. On the macro-scale, it can also be considered as an alternative to electromagnetic (EM) wave based systems, especially in environments where there is significant attenuation to EM wave power. This paper goes beyond the unbounded free space propagation to examine three macro-scale environments: the pipe, the knife edge, and the mesh channel. Approximate analytical expressions shown in this paper demonstrate that MC has an advantage over EM wave communications when: 1) the EM frequency is below the cut-off frequency for the pipe channel, 2) the EM wavelength is considerably larger than the mesh period, and 3) when the receiver is in the high diffraction loss region of an obstacle.