Airborne relay network

Overview
Several organizations have begun experimenting with high-flying wireless relays (airborne relay network) that essentially act as ultra-low­ orbit (atmospheric) satellites to provide Internet access across a wide area with little infrastructure required on the ground. While most of this technology is aimed at expanding Internet coverage to emerging markets in order to create economic opportunities in developing regions,. . . similar networks [could be deployed] in regions without cellular coverage.



Google’s Project Loon [24] aims to place a fleet of high-altitude (20 km) balloons in the stratosphere to provide cellular coverage to those who do not have it. The balloons share LTE technology and spectrum with cellular providers, communicating with base stations on the ground that provide Internet backhaul access as well as other balloons to create a mesh network. The balloons rise or descend to move with different wind currents in the desired direction and can stay aloft up to 100 days.

Rather than balloons, Facebook and the Internet.org project aim to use a fleet of high-altitude solar-powered drones. The project hopes to achieve much longer flight times than Project Loon and the ability to better control the flight patterns of their Internet relays. Some of the research challenges they aim to address are outlined in [25].

In addition to using atmospheric satellites for providing wireless coverage, researchers are exploring the use of lower-level UAVs in providing communications using technologies such as WiFi.