  By considering potential health problems that a fully covering receiver may
cause in vessel-like environments, the implementation of a partially covering
receiver is needed. To this end, distribution of hitting location of messenger
molecules (MM) is analyzed within the context of molecular communication via
diffusion with the aim of channel modeling. The distribution of these MMs for a
fully covering receiver is analyzed in two parts: angular and radial
dimensions. For the angular distribution analysis, the receiver is divided into
180 slices to analyze the mean, standard deviation, and coefficient of
variation of these slices. For the axial distance distribution analysis,
Kolmogorov- Smirnov test is applied for different significance levels. Also,
two different implementations of the reflection from the vessel surface (i.e.,
rollback and elastic reflection) are compared and mathematical representation
of elastic reflection is given. The results show that MMs have tendency to
spread uniformly beyond a certain ratio of the distance to the vessel radius.
By utilizing the uniformity, we propose a channel model for the partially
covering receiver in vessel-like environments and validate the proposed model
by simulations.
