The controlled airspace should be designated by the following terms:
1. Flight Information Region (FIR);
2. Control Area (CTA);
3. Control Zone (CTR).

1. Flight Information Region (FIR):
Flight information region (FIR) shall normally be established to encompass the entire airspace over the territory of a state, and to cover the whole of the ATS route structure to be served by such region or a state.
A flight information region shall include all airspace within its lateral limits, except as limited by an upper flight information region (UIR).
FIRs are those portions of the airspace where it is determined that flight information service and alerting service will be provided.
Upper Flight Information Region (UIR) and Upper Control Area (UTA):
Where it is desirable to establish Upper Information Region (UIR) or upper control areas (UTA) through which high flying aircraft have to operate, a flight information region or control area, should include the lower and upper limit and the lateral limits of flight information regions or control areas.
FIR/UIR boundaries areas are determined on the basis of Regional Air Navigation Agreements that approved by the Council of ICAO.
2. Control Area (CTA):

Control area (CTA) shall be established so as to encompass sufficient airspace to contain the flight paths of those IFR/VFR flights or portions thereof to which it is desired to provide the applicable parts of the air traffic control service, taking into account the capabilities of the navigation aids normally used in that area.
* A lower limit of a control area shall be established at a height above the ground or water of not less than 200 m (700 ft).
Note: The lower limit of a control area should, when practicable and desirable in order to allow freedom of action for VFR flights below the control area, be established at a greater height than the specified minimum.
When the lower limit of a control area is above (3 000 ft) MSL it should coincide with a VFR cruising level.

An upper limit of a control area shall be established when either:
1. Air traffic control service will not be provided above such upper limit; or
2. The control area is situated below an upper control area, in which case the upper limit shall coincide with the lower limit of the upper control area.
When established, such upper limit shall coincide with a VFR cruising level.
Control Area (CTA) includes:
a) ATS routes; and
b) Terminal Control Areas (TMAs).

a) ATS route:
A specified route designed for channeling the flow of traffic as necessary for the provision of air traffic services. (The term ATS route is used to mean variously, airway, advisory route, controlled or uncontrolled route, arrival or departure route, etc). ATS routes shall be identified by designators.
Note: An ATS route is defined by route specifications that include an ATS route designator, the track to or from significant points (waypoints), distance between significant points, reporting requirements and, as determined by the appropriate ATS authority, the lowest safe altitude.
Airway:
A control area or portion thereof established in the form of a corridor.