4 Introduction

3GPP46.001Full rate speechProcessing functionsRelease 17TS

Figure 1 presents a reference configuration where the various speech processing functions are identified. In this figure, the relevant technical specifications for each function are also indicated.

In figure 1, the audio parts including analogue to digital and digital to analogue conversion are included to show the complete speech path between the audio input/output in the Mobile Station (MS) and the digital interface to the PSTN. The specification of the audio parts are contained in GSM 03.50 [2] (Transmission plan aspects of the speech service in the GSM PLMN system). These aspects are only considered in the GSM 06‑series to the extent that the performance of the audio parts affect the performance of the speech transcoder.