Subdivision enables a high degree of frequency reuse.
Rather than spreading the entire frequency over the entire footprint, it spreads subsets of the frequency over smaller footprints. And, most important, it reuses these subsets in nonadjacent footprints. On-board storage and processing. To overcome rain fade, signals need to be digital so that they can incorporate error codes. According to Edelman, ACTS uses the same TDMA system that you'll find in terrestrial cellular systems.