In the mobile device transmission, the air interface is a through wireless communication, to link with mobile phone end user base stations. In GSM/UMTS, various forms of UTRA standard is air interface, also is a kind of access mode "access modes." on mobile phones, "air interface" said mobile phone base stations and wireless transmission between standard. It defines each wireless channels use frequency and bandwidth, or defined by coding method.
In the OSI model under, air interface belongs to the first layer and layer 2 implementation.
