Since the Earth's horizon limits the coverage, each satellite has a well-defined geographical area. These areas are smaller than typical GEO satellite footprints and are isolated from each other by the horizon. This feature can be used to simplify data routing and network management. The TropNet constellation would cover the Earth tropical zone as shown below. TropNet can connect globally but does not independently cover the whole globe.
Complex technology is part of the ground station instead of required in the satellite.
TropNet can be easily expanded by adding additional satellites in the same equatorial plane. 23 degrees latitude. This reduces the cost and the number of satellites required significantly. For example GlobalStar requires 48 satellites, Iridium 66, and Teledesic proposes 840 satellites. In comparison, TropNet only requires 16 to 24.