Estimation of the Starlink Global Satellite System Capacity

Abstract

In this paper, the capacity of the Starlink global satellite system is considered and evaluated. We will evaluate using the link budget. The code gain due to the addition of error-correcting coding has been added to the calculation of the link budget. At high frequencies, the orbit height is limited to 340 km. Most of the satellites are planned to be located at this altitude. For lower frequencies, higher orbits can be used: 550 km and 1110 km. To date, the spectral efficiency of possible variations of Starlink is limited to 4.5 bits/Hz. At the time of this writing, there are approximately 3300 Starlink satellites in orbit, which theoretically provides a capacity of about 20 Tbps due to the reduced level of modulation and the use of only one polarization. At the end of the first stage of launching satellites into orbit, the system capacity will be 88.5 Tbps over most of the studied frequency band and it will increase as more satellites are launched into low-earth orbit. Working in the future in dual polarizations with 64QAM and with a planned 11 943 satellites, SpaceX will be able to provide Internet access anywhere in the world with high bandwidth and spectral efficiency.

Keywords

• starlink
• link budget
• modulation
• capacity
• signal-to-noise ratio
• spectral efficiency
• informational efficiency
• noise immunity
• error-correcting code
• modelling