E-CGR: Energy-aware Contact Graph Routing over Nanosatellite Networks

Satellite constellations are envisioned as meaningful transport networks to forward data throughout the world, both as a solution for areas where there are no other telecommunication infrastructures or as a backup solution to support the terrestrial network. Low Earth Orbit (LEO) satellites are the most appealing for this purpose due to the achievable performance keeping low design and deployment costs. Mega-constellation made of thousands of small LEO satellites are planned to be employed to cover the entire Earth's surface. However, smaller is the size and weight of satellites, higher are the technological challenges and stricter are the hardware constraints which affect the data forwarding process and have to be taken into account. Energy is one of them. Telecommunication hardware energy consumption is considerable, especially in case of high traffic volumes, while energy storage capacity and battery recharge rate are limited due to the small battery size and solar panel surface area, respectively. In this paper, we propose a novel energy-aware routing algorithm based on the Contact Graph Routing (CGR) called E-CGR. E-CGR exploits static and known a priori information about contacts to compute routing paths from sources to destinations which are then "validated" and "confirmed" from the energy viewpoint.