For continuous, global coverage, how many satellites are generally sufficient for a GEO Systems constellation?

Only three to four satellites suffice for coverage

Geostationary Orbit (GEO) satellites provide coverage from a very high altitude, enabling a single satellite to illuminate approximately one-third of the Earth's surface continuously due to its expansive footprint from that height. Because of this vast coverage area, the requirement for achieving global coverage is remarkably low; only a small constellation consisting of three to four strategically positioned satellites is generally needed to maintain continuous contact with the entire planet. In sharp contrast, LEO systems require massive constellations numbering in the thousands because each individual satellite’s visibility footprint over the ground is much smaller at their lower altitude.