Loon offers network controller for new constellations

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MOUNTAIN VIEW, California — Loon, a subsidiary of Google’s parent company Alphabet, is promoting networking technology and user interfaces it developed to operate its high-altitude balloons for constellations of nongeostationary orbiting satellites.

“Our network on Loon and these low Earth orbit and medium Earth orbit constellations have a lot of similar challenges in network operations,” Brian Barritt, Loon technical lead, said Oct. 10 at Satellite Innovation 2018 here.

It’s common for people seeking access to the network to be moving around. In these networks, though, the middle of the network is also moving.

“The path the data may take, especially if your constellation has inter-satellite links or if it has multiple spot beams, can change very rapidly,” Barritt said.

Those changes can cause service disruption. To prevent that, Loon developed a temporospatial software defined network controller for both wired and wireless networks. It looks forward over time to predict connectivity and quality by evaluating the positions of all the ground stations, user terminals, satellites and taking into account global weather, Barritt said.

In addition, customers can load the controller with their network service goals like latency requirements.

“It’s up to the controller to figure out what inter-satellite links and ground segment routers to traverse, what gateway links to use how that should be transitioned over time,” Barritt said. “It avoids any disruption to network flows by pre-scheduling routing table changes, tasking changes to steerable beams and radio resource management, changes to channel and channel bandwidth all together in unison. So there is no delay, no disruption.”