02.303GPPMan-machine Interface (MMI) of the Mobile Station (MS)TS
This clause gives the requirements or guidelines for the MMI of the input related MS features. Basic requirements on these features are given in GSM 02.07  and GSM 02.40 .
2.2 MMI related to MS access
No requirements additional to those in other GSM specifications (Reference GSM 02.17 , 11.10 ).
2.3 MMI related to MS features
The three first issues are covered in GSM 02.07 :
* Country / PLMN selection:
The method is manufacturer optional.
* International Access Function ("+" key):
The physical means of entering the characters 0‑9, +, * and # (i.e. the SELECT function) may be keypad, voice input device, DTE or other, but there must be means to enter this information.
The relationship on the keypad between the numbers and letters (where used) is important when mnemonic dialling may be used. The following relationship is therefore preferred though optional.
See also subclause 5.2.1.
* ACCEPT, SEND and END functions:
The physical means to perform these functions may be keypad, voice input device, DTE or other, but there must be means to perform these functions. ACCEPT and SEND may use the same means.
* Setting of called Number Fields (Type of Number), use of the "+" key function:
Users may enter a called number in two formats, called here International or Open. The Type of Number (TON) may be set to other values if required, but the procedure for this is not defined here.
This is entered by starting with a "+" followed by country code, even for national calls. This method is preferred for roaming and international calls, and highly desirable for storage of short codes or for call-forwarding.
This sets the TON to "International" – see GSM 04.08  table 10.50.
This is when the "+" is not entered, and the number is entered in the normal way for that network. The number may require a prefix or escape code as normal, for example for entering the international access code or national access code (often "0").
This sets the TON to "Unknown" – see GSM 04.08  table 10.50. (This is not the "National" case, which does not permit prefix or escape digits).
Care should be taken with this format, since the dialled number will only be correct in a given network, and may be wrong when roaming. Caution must be applied when using stored numbers or call-forwarding.
* Setting of Called Number Fields (Number Plan Indicator):
The default Number Plan Identification (NPI) shall be CCITT E.164  if all the digits are in the range 0‑9 and the NPI shall be "unknown" if other number information is included. However, if the user selects (or has selected) a particular NPI (procedure not defined) then that NPI shall be used.
* Entry of Bearer Capability Information Elements (BCIE):
This is required in order to indicate information such as whether it is a voice or data call, facsimile, synchronous or asynchronous etc. The method for entering this information is of mobile manufacturer’s option. For those Mobile Stations offering only telephony (and emergency calls), the default BCIE shall be for telephony (or emergency call). For Mobile Stations supporting non-voice services, there shall be means to set the BCIE required, by reading the appropriate field in the SIM and possibly otherwise. This field may be associated with or independent of the called number.
2.4 MMI related to user information
These issues are covered in GSM 02.40 :
* Selection of language of announcements:
No additional requirements are defined in this specification.
2.5 Other input features
No requirements additional to those in other GSM specifications (Reference GSM 03.14  11.10 ).