What is the setting of Ender's Shadow by Orson Scott Card?

This is a science fiction novel set at some time in the future when space travel across light-years is known by at least two species, humans and Buggers. The action starts in Rotterdam, moves to Battle School in a space station and from there outward to the Command School in an asteroid. In Battle School the ventilation system becomes a setting from which Bean can observe teachers, students and school officers. He uses the ventilation system later to trap Achilles.