Comment Re:Region-Specific (Score 1) 86
So you make a regional system by setting up the orbits so that there are always 3-4 satellites visible from the region of interest. Occasionally you will be able to get a fix elsewhere in the world, but usually not.
Actually, while it's generally pretty trivial to make sure 3-4 (5+ would be better) are visible from any given point on Earth, it's rather harder (read: nearly impossible) to make sure 3-4 are visible from any point in India but NOT from any point outside India.
Unless the satellites are in geosynchronous orbits, of course, but then you're not going to have the separations you need for a good solution.
Realistically, India needs an array like GPS or GLONASS, not just seven satellites.