The next step was to make sure it worked at far distances, since the scope of its default state was not much different from that of an aether letter.
To maximize the resources spent on an innovation, it must either (1) fix an actual problem, and/or (2) improve on the existing status quo.
If the radio's only range was the same as that of the aether letter, then the amount of resources they spent—the materials, the logistics, and including the fact that several teams dropped their current projects to help out—would not have been worth it.
To expand the range, and to a flexible degree, they copied how it was done in Terran: The Signal Tower.
This Signal Tower, while inspired by the functions in Terran, was hundreds of times more intricate than the ones they had seen back home. Terran did not have mega and varying extreme weathers, strong monsters, frequent wars, aether, and so on.
