Relays Data Across A Distance Of 540 Nautical Miles

Alphabet's Loon has reached what it is calling a major milestone after successfully relaying data across 1,000 km (about 540 nautical miles) between a network of seven balloons.

Writing in the Loon Blog, Loon head of Engineering Salvatore Candido says that one of the biggest technical challenges for the project is what's known as the "backhaul connection", which is the distance that a signal must pass from a ground access point to the first balloon in the network. To overcome the limits of the distance that signal can travel, Loon plays a game of "leapfrog" with the balloon constellation, with the backhaul signal jumping from one balloon to another.

For the milestone experiment, the connection originated from the launch site in Navata to a balloon floating at about 65,000 feet. "That data traveled nearly 1,000 km along a network of six additional balloons, going from desert to mountains and back again," Candido writes. "A few weeks later, we achieved another milestone by successfully sending data over 600 km between two balloons — our longest point-to-point link to date. These connections were made using custom-built antennas mounted to the bottom of our communications payload. Their accuracy is equivalent to throwing a ball 100 meters and landing it in a wastebasket. In this case, however, the wastebasket was in constant motion in the stratosphere."

Candido says that each balloon in the network can pass the connection to other balloons while at the same time using it to connect users on the ground.

He says that Alphabet is preparing to launch Loon as a commercial service next year.

(Image provided by Loon)

FMI: Loon Blog