Three satellite eras

Dramatic increases in the number of two-way satellite terminals is a key issue in current spectrum policy, e.g. the argument between satellite and cellular interests in the millimeter wave bands. Most Earth stations used to be TV receivers. However, the growth of satellite broadband service is increasing the number of Earth station transmitters.While it's an over-simplification, but it helps me to think of the number of earth station transmitters (often referred to as uplinks) growing in three overlapping and cumulative eras.