Several queueing processes may be modeled as random walks on a multidi
mensional grid. In this paper the equilibrium distribution for the cas
e of a two-dimensional grid is considered. In previous research it has
been shown that for some two-dimensional random walks the equilibrium
distribution has the form of an infinite series of products of powers
which can be constructed with a compensation procedure. The object of
the present paper is to investigate under which conditions such an el
egant solution exists and may be found with a compensation approach. T
he conditions can be easily formulated in terms of the random behaviou
r in the inner area and the drift on the boundaries.