I found this buried deeply in my pile of Handbook notes.
Archeologists were working in Italy. They dug down one meter and found strands of copper wire. After much research, they determined that during the time of Leonardo daVinci, the Italians already had a phone system.
Not to be outdone, another team of archeologists working in Greece dug two down two meters and found strands of glass. They concluded, after much extensive research and debate, that there was a fiber-optic communications system at the time of Aristotle
A third team of archeologists working in Israel were digging as well, and at five meters they found neither copper wire nor glass strands. From this they concluded that, at the time of Joshua, the indigenous population had an extensive wireless network.