  The sum capacity of a class of layered erasure one-sided interference
channels is developed under the assumption of no channel state information at
the transmitters. Outer bounds are presented for this model and are shown to be
tight for the following sub-classes: i) weak, ii) strong (mix of strong but not
very strong (SnVS) and very strong (VS)), iii) ergodic very strong (mix of
strong and weak), and (iv) a sub-class of mixed interference (mix of SnVS and
weak). Each sub-class is uniquely defined by the fading statistics.
