Japan has started its own version of a global positioning system. The new system uses 4 Michibiki satellites in orbit around the earth. The final one was launched in October of last year. They complement American GPS satellites. At least one of the satellites is always above Japan.
Signals from that satellite come from an angle that tends to prevent tall buildings getting in the way. Smartphones and car-navigation systems that can receive those signals will be able to show their positions more accurately and stably.