A Control-theoretic Model for Bidirectional Molecular Communication Systems

TL;DR

This paper introduces a control-theoretic framework for bidirectional molecular communication systems, enabling systematic analysis and design of feedback-mediated molecular communication channels considering diffusion and boundary dynamics.

Contribution

It presents a novel control-theoretic modeling approach for bidirectional molecular communication, incorporating feedback dynamics and boundary effects, which was lacking in prior unidirectional models.

Findings

Frequency response analysis provides design guidelines for MC channels.

The framework captures lag effects in molecular transmission and reception.

Design procedure for MC channels with specific specifications is demonstrated.

Abstract

Molecular communication (MC) enables cooperation of spatially dispersed molecular robots through the feedback control mediated by diffusing signal molecules. However, conventional analysis frameworks for the MC channels mostly consider the dynamics of unidirectional communication, lacking the effect of feedback interactions. In this paper, we propose a general control-theoretic modeling framework for bidirectional MC systems capable of capturing the dynamics of feedback control via MC in a systematic manner. The proposed framework considers not only the dynamics of molecular diffusion but also the boundary dynamics at the molecular robots that captures the lag due to the molecular transmission/reception process affecting the performance of the entire feedback system. Thus, methods in control theory can be applied to systematically analyze various dynamical properties of the feedback system. We perform a frequency response analysis based on the proposed framework to show a general design guideline for MC channels to transfer signal with desired control bandwidth. Finally, these results are demonstrated by showing the step-by-step design procedure of a specific MC channel satisfying a given specification.