User blog comment:Zathronas/Speculative Author - RWBY Relativity/@comment-25396609-20160225025456/@comment-24218038-20160225052347

The CCT is based on principles that exist in our world, it isn't something that needs explaining in-universe because the answer is right in front of us. RF communication.

Hmmm. I disagree. here's the Ozpin's quote:

''Prior to the invention of the CCTS, long range communication was extremely limited. The discovery and development of radio technology allowed for communication within the boundaries of most Kingdoms. But communication with other parts of the world was restricted to the physical delivery of messengers.''

With every alternative form of communication that was proposed, there seemed to be the perfect obstacle.

The destructive nature of the creatures of Grimm severely limited the reliability of ground-based technologies.

''The concept of relay satellites orbiting around the planet was promising. Unfortunately, modern man has yet to make the technological advancements to achieve spaceflight, as all known Dust types lose their power as they begin to leave Remnant's atmosphere.''

Eventually, it was the people of Atlas, the world's leader in science and technology, that developed the Cross Continental Transmit system.