Why does GPS work when underground and under big buildings but radio signals, Wi-Fi, and cell phone signals struggle?

Question

Why does GPS work when underground and under big buildings but radio signals, Wi-Fi, and cell phone signals struggle?

In: 4773

Answer 1

GPS itself doesn’t work well or at all underground or in buildings. However most devices these days don’t rely on the GPS signal alone. Smartphones also triangulate using cell towers and known wifi hotspots. Additionally there are signal repeaters that can be installed that will boost the signal in areas where there are known blockages. The same can be done for cell phone, WiFi, and radio.