In mobile or wireless communication, the air interface is the radio-based communication link between the mobile station and the active base station. In GSM/UMTS, the various UTRA standards are air interfaces, and are also (but not exclusively) referred to as "access modes".
In the OSI model, the air interface comprises layers 1 and 2 of the mobile communications system, establishing a point-to-point link between the mobile station and the base station.
