Space X plans to start offering satellite-based broadband Internet as soon as next year. Amazon and One Web have also launched fleets consisting of thousands of small, low-orbit satellites that will provide Internet access and high-speed data communications to remote areas.
Researchers led by Ankit Singla from ETH Zurich are investigating how the performance of such large networks could be improved.
Mobile rather than static
According to the researchers, Internet from space is creating completely new premises. Because unlike the Internet infrastructure on the ground, the infrastructure in orbit is not static. The satellites represent nodes that constantly change their relative positions. “In order to implement satellite-based broadband Internet, we have to rethink practically every aspect of conventional Internet design,” Ankit Singla explains.
With her team, she has developed a mathematical model that allows the design of satellite-based networks to be optimized. The researchers report that they tested their approach using the infrastructures of Space X and Amazon. They were able to increase their satellite network efficiency by 54 and 45 percent respectively. Their approach could also be applied to other satellite networks.
The principle is based on reducing the number of nodes – i.e. satellites – through which the data is transmitted. This frees up resources that can then be used for other connections. In concrete terms, this means that a satellite should not necessarily transmit the data to the satellite that is closest it, but could well connect to a more distant one, thus spanning greater distances.
At the same time the reduction in the number of intermediate nodes must not affect the length of the path as a whole, according to ETH. Otherwise, the latency, i.e. the delay in data transmission, would worsen. In addition, it is important that the connections between the satellites do not change too often, because each establishment of new connections can take several dozen seconds. Meanwhile, no data is being transmitted.
What is new about the network design is that the connections between the satellites are established according to repeating patterns: The connection pattern repeats on each satellite in the network, so they are all connected in the same way and the connections remain stable over time, even as the satellites move. Which pattern is best depends, among other things, on the geometry of the satellite constellation.
Written by: sda