Diffusive Molecular Communication in Biological Cylindrical Environment

Abstract

Diffusive molecular communication (DMC) is one of the most promising approaches for realizing nano-scale communications in biological environments for healthcare applications. In this paper, a DMC system in biological cylindrical environment is considered, inspired by blood vessel structures in the body. The internal surface of the cylinder boundary is assumed to be covered by the biological receptors which may irreversibly react with hitting molecules. Also, information molecules diffusing in the fluid medium are subject to a degradation reaction and flow. The concentration Green's function of diffusion in this environment is analytically derived which takes into account asymmetry in all radial, axial and azimuthal coordinates. Employing obtained Green's function, information channel between transmitter and transparent receiver of DMC is characterized. To evaluate the DMC system in the biological cylinder, a simple on-off keying modulation scheme is adopted and corresponding error probability is derived.Particle based simulation results confirm the proposed analysis. Also, the effect of different system parameters on the concentration Green's function are examined. Our results reveal that the degradation reaction and the boundary covered by biological receptors may be utilized to mitigate intersymbol interference and outperform corresponding error probability. Index TermsDiffusive molecular communication (DMC), biological environment, partial differential equation, Green's function.

Diffusive Molecular Communication in a Biological Spherical Environment With Partially Absorbing Boundary

“…Finally, the error probability of DMC with a simple on-off keying modulation over this channel is derived. The results in this section are adapted from our previous work [20] which is necessary to support the results that will come in Section V.…”

“…Considering (7) and the obtained separated solutions of (11), (15), (20), and (24), the principal solution of the primal diffusion equation (3) subject to the boundary condition (5) is given by…”

“…In [19], the authors obtained the channel impulse response for a 3-D microfluidic channel environment in the presence of flow where the boundaries are reflective. Also, in [20] we obtain the concentration Green's function in a biological cylindrical environment where the boundary is covered by receptor proteins and information molecules are subject to both flow and chemical degradation.…”

Secrecy Capacity of Diffusive Molecular Communication Under Biological Spherical Environment

“…Even though, some literatures suggest an unbounded environment in analysis of DMC [5,6]. Whereas according to [7] unbounded assumption is not realistic in MC applications. Further, inspired by the shape of blood vessels and microfluidic channels, [8] and [7] suggest bounded cylindrical.…”

Analytical derivation of the impulse response for the bounded 2-D diffusion channel

“…Besides the channel impulse response, the capacity of the single-input single-output molecular communication channels with flow and drift is derived in [12]. In [13], an angle dependent approach is taken to consider a diffusion-based molecular communication system in a biological cylindrical environment. In the nature, it is quite common to encounter diffusion processes that are bounded by membranes.…”