San Juan's infrastructure and UNESCO world heritage sites have made it challenging to provide fiber connectivity through Old San Juan. But that makes it an ideal city to test Facebook's Terragraph system, the 60GHz millimeter-wave wireless tech that blasts internet through buildings along a network of short-distance cell towers. This offers an alternative to costly fiber-optic lines, and the Terragraph device can be attached to existing infrastructure, like street lights and utility poles.

"Looking ahead, we are excited about the potential opportunities Terragraph provides to expand high-quality gigabit internet experience throughout the island of Puerto Rico," said Gino Villarini, AeroNet's founder and president.

Facebook first announced Terragraph in 2016, and last year, the startup Common Networks began using it to deliver 5G home broadband in Alameda, California. It has also been tested in San Jose, and Qualcomm is putting Terragraph tech in its chipsets, so that manufacturers can build 60GHz broadcast equipment.