This story is a bit more technical that what I’ve previously shared. That said, I’ll link to some definitions for you non-technical readers — I promise, this one is going to be worth the extra effort. However, a bit of technology is required in the telling — so please bear with me.
Let’s step back in time. The first transoceanic cables used copper wire as the conductor that carried signals between continents. Unfortunately, the technology at the time was such that the cables were extremely bandwidth-limited and could therefore support a very small number of simultaneous conversations.
Furthermore, the physics of metallic transmission dictated that the transmitted signals would decay over distance, making it necessary to amplify and/or regenerate the transmitted signal periodically. This was costly, and required additional circuitry to filter electromagnetic interference and increase the signal level every few thousand feet.