A three-dimensional space criss-crossed by airways. In keeping with lCAO (â€“) rules, worldwide airspace is subdivided into various classes. The provision of air traffic control is defined for each class, together with the applicable flight rules (â€“ DELTA, Upper airspace). Distinction is made between civil and military airspace; each of these is primarily reserved for one user group. Since integration (â€“), skyguide manages all of Swiss and some foreign delegated airspace, and in so doing improves both flexibility of use and capacity.