  In preceding papers a Landauer-Buttiker type representation of bulk current
transport has been successfully used for the numerical simulation of the
magneto transport of 2-dimensional electron systems in the high magnetic field
regime. In this paper it is demonstrated, that this representation is in full
agreement with a treatment of the bulk current transport as a tunneling process
between magnetic bound states. Additionally we find a correspondence between
our network representation and the bulk current picture in terms of mixed
phases mapped on a checkerboard: At half filled Landau level (LL) coupled
droplets of a quantum Hall (QH) liquid phase and coupled droplets of an
insulator phase phase exist at the same time, with each of them occupying half
of the sample area. Removing a single electron from to such a QH liquid droplet
at half filling completes the QH transition to the next higher QH plateau.
Adding a single electron to such a droplet at half filling completes the QH
transition to the previous lower QH plateau. As a consequence, the sharpness of
the QH plateau transitions on the magnetic field axis depends on the typical
size of the droplets, which can be understood as a measure of the disorder in
the sample.
