Dunno who down-voted you - but what environment are you operating in? One of the claims for the Japanese system (you can see it in its orbital design) is that i

Dunno who down-voted you - but what environment are you operating in? One of the claims for the Japanese system (you can see it in its orbital design) is that it specifically provides more opportunities for overhead signal coverage, increasing reliability/accuracy in mountainous and heavily urbanized (ie, skyscraper canyons) terrain. That all being said, I'm also of the opinion that this is more of a defense play. QZSS has the nice property have using geosync/geostationary orbits - I'd imagine that makes ASAT work a bit harder.