Structures of tunneling nanotubes (TNTs) of the circular cross-section of 50 and 200 nm and length up to 1 mm form a communication system between cells. While transport of material such as endocytic vesicles, mitochondria, proteins, cytoplasmic molecules, etc., is experimentally proven, a possible transfer of electric and electromagnetic energy across TNTs corresponding to electrotechnical processes of excitation, propagation, and amplification in cavity systems is yet in a beginning stage of research. The ideas presented in this paper are based on technical mechanisms applied to submicroscopic systems. Main features of corrugated periodic structures, electromagnetic circular waveguides, the Manley–Rowe amplification, the Fröhlich non-linear interaction of coherent electric polar vibrations, and description of cut-off frequency propagating limits in the waveguide and cavities and along periodic structures are discussed. We suggest that cell-to-cell connection with TNTs may form a unified coherent cavity system which enables simultaneity and mutual cooperation in multicellular organisms.