How do you design a LEO satellite constellation for global coverage?

Constellation design balances coverage, capacity, and cost. Design process: Coverage requirements - Global vs regional, continuous vs periodic, Minimum elevation angle for link quality; Constellation geometry - Walker patterns (i:t/p/f notation - inclination, total satellites, planes, phasing), Polar vs inclined orbits, and Street-of-coverage vs distributed. Optimization: Minimize satellite count while meeting coverage, Consider inter-satellite link topology, and Ground station visibility. Orbital dynamics: Altitude selection (drag vs coverage vs latency), Differential precession for relative motion, and Orbit maintenance delta-v budget. Launch deployment: Ride-share opportunities, Phasing between planes, and Orbit plane spacing from RAAN drift. Examples: Iridium (66 satellites, 86.4 deg, 6 planes), GPS (24+, 55 deg, 6 planes), and Starlink (thousands in multiple shells). Coordination: ITU frequency coordination and Space debris mitigation (deorbit plan).