The work considers the two-user BC and IC (MISO and MIMO), and tries to concisely capture the effect of having predicted, current and delayed CSIT, as well as concisely captures the effect of the quality of CSIT offered at any time, about any channel.
The work then takes a step in exploring the interplay between topology (some links are statistically stronger than others), feedback and performance. This is done for the two user BC with random fading, in the presence of a simple two-state topological setting of statistically strong vs. weaker links, and in the presence of a practical ternary feedback setting of `alternating channel state information at the transmitter' (alternating CSIT) where for each channel realization, this CSIT can be perfect, delayed, or not available.