This European Telecommunications Standard (ETS) specifies a profile of AT commands and recommends that this profile be used for controlling Mobile Equipment (ME) functions and GSM network services from a Terminal Equipment (TE) through Terminal Adapter (TA). The command prefix +C is reserved for Digital Cellular in ITU-T Recommendation V.25ter [14]. This ETS has also the syntax details used to construct these extended GSM Commands. Commands from ITU-T Recommendation V.25ter [14] and existing digital cellular standards (TIA IS-99 [15] and TIA IS-135 [16]) are used whenever applicable. Some of the new commands are defined such way that they can be easily applied to ME of networks other than GSM. ITU-T.31 [11] and T.32 [12] fax AT commands may be used for GSM fax transmission from TE. This ETS assumes an abstract architecture comprising a TE (e.g. a computer) and a ME interfaced by a TA. The span of control of the defined commands should allow to handle any physical implementation that this abstract architecture may lead to: - TA@ ME and TE as three separate entities; - TA integrated under the ME cover@ and the TE implemented as a separate entity; - TA integrated under the TE cover@ and the ME implemented as a separate entity; - TA and ME integrated under the TE cover as a single entity.