Adaptive transmission protocol for molecular communications in cellular tissues

One form of molecular communications for short range transmission between nanomachines is Calcium Signaling. This form of signaling is commonly found in cellular tissues, which consist of tightly packed cells, whereby Ca²⁺ ions propagate and diffuse between the cells. However, the natural flexible structure of cells usually leads to them dynamically changing shapes under certain strains and forces. Since the interconnected cells form a tissue, changes in the shape of one cell will change the shape of neighboring cells and the tissue as a whole. This may in turn significantly impair the communication channel between the nanomachines (which we assume to be embedded within the cells). In order to counter this problem, we propose an adaptive transmission protocol for Ca²⁺ signaling based molecular communications in cellular tissues. The protocol operates in two phases. The first phase utilizes information metrics to infer the state of the tissue; second phase then involves the determination of the most appropriate time-slot for bit transmission. In this way, we aim to improve the information rate by using a time slot length that is appropriate for the prevailing type of tissue deformation. Through simulation studies we show that, for two types of deformation and two different topologies, our protocol can improve the information rate performance by 15%.