This TS describes the transmission planning aspects pertaining to the speech service in the GSM PLMN system. Due to technical and economic factors, there cannot be full compliance with the general characteristics of international telephone connections and circuits recommended by the ITU T.
This TS gives guidance as to the precautions, measures and minimum requirements needed for successful interworking of the PLMN with the national and international PSTN. This TS identifies a number of routeing and network configurations. The objective is to reach a quality as close as possible to ITU T standards in order to safeguard the performance seen by PSTN customers.