  We study a symmetric random walk (RW) in one spatial dimension in
environment, formed by several zones of finite width, where the probability of
transition between two neighboring points and corresponding diffusion
coefficient are considered to be differently fixed. We derive analytically the
probability to find a walker at the given position and time. The probability
distribution function is found and has no Gaussian form because of properties
of adsorption in the bulk of zones and partial reflection at the separation
points. Time dependence of the mean squared displacement of a walker is studied
as well and revealed the transient anomalous behavior as compared with ordinary
RW.
