  The fact that the results for 2-receiver broadcast channels (BCs) are not
generalized to the 3-receiver ones is of information theoretical importance. In
this paper we study two classes of discrete memoryless BCs with non-causal side
information (SI), i.e. multilevel BC (MBC) and 3-receiver less noisy BC. First,
we obtain an achievable rate region and a capacity outer bound for the MBC.
Second, we prove a special capacity region for the 3-receiver less noisy BC.
Third, the obtained special capacity region for the 3-receiver less noisy BC is
extended to continuous alphabet fading Gaussian version. It is worth mentioning
that the previous works are special cases of our works.
