AbstractSatellites offer a promising alternative for mobile access to the Internet by both pedestrians, and more importantly, from vehicles. As such, satellites provide an essential complement to the cellular radio (UMTS) infrastructure in sparsely populated areas where high bandwidth UMTS cells cannot be economically deployed. In this paper, we analyse various mobile Internet applications in representative urban scenarios for two LEO constellations (one with polar orbits and the other with inclined orbits), as well as for some simple GEO configurations. To this end, we develop a satellite channel propagation model that includes shadowing from surrounding building skylines based on actual data in a built‐up area.Using these tools, we analyse various Internet applications and the performance of various TCP schemes in different topologies. Copyright © 2004 John Wiley & Sons, Ltd.