Transmission Protocols for Calcium-Signaling-Based Molecular Communications in Deformable Cellular Tissue

Molecular communications is a new paradigm that enables nanomachines to communicate within a biological environment. One form of molecular communications is calcium (Ca²⁺) signaling, which occurs naturally in living biological cells. Ca²⁺ signaling enables cells in a tightly packed tissue structure to communicate at short ranges with neighboring cells. The achievable mutual information of Caa²⁺ signaling between tissue embedded nanomachines is investigated in this paper, focusing in particular on the impact that the deformation of the tissue structure has on the communication channel. Based on this analysis, a number of transmission protocols are proposed; nanomachines can utilize these to communicate using Ca²⁺ signaling. These protocols are static time-slot configuration, dynamic time-slot configuration, dynamic time-slot configuration with silent communication, and improved dynamic time-slot configuration with silent communication (IDTC-SC). The results of a simulation study show that IDTC-SC provides the maximum data rate when tissues experience frequent deformation.