VLEO Eavesdropping Modeling and Prevention in Multi-Constellation Satellite Networks

The satellite-to-ground link is susceptible to eavesdropping from various open-space locations. In this paper, we investigate a new eavesdropping scenario in a multiconstellation satellite network, where very low earth orbit (VLEO) satellites eavesdrop on low earth orbit (LEO) constellations from legitimate positions. We model the VLEO eavesdropping risks in a theoretical way and propose a crossinterference scheme called LEO active cross-interference (LEOACI) to protect satellite-to-ground downlinks from eavesdropping attacks. The scheme prevents eavesdropping by scheduling spare satellites to transmit artificial noise (AN) over the protected link. Finally, we conduct simulations to evaluate the performance of the LEO-ACI scheme and it shows that VLEO eavesdroppers can possess high eavesdropping coverage and long duration. Meanwhile, the LEO network can ensure that 98.5 % of downlinks are free from eavesdropping at the cost of 12.3 % of the satellite-to-ground capacity degradation.