3 Definitions, symbols and abbreviations

26.1933GPPAdaptive Multi-Rate - Wideband (AMR-WB) speech codecRelease 17Source controlled rate operationSpeech codec speech processing functionsTS

3.1 Definitions

For the purpose of this document, the following definitions apply.

frame: Time interval of 20 ms, corresponding to the time segmentation of the Adaptive Multi-Rate Wideband speech Codec, also used as a short term for a traffic frame.

traffic frame: Block of 132..477 information bits transmitted on the speech traffic channels.

SID frame: Frame that conveys information about the acoustic background noise.

speech frame: Traffic frame that has been classified as SPEECH_GOOD, SPEECH_BAD or SPEECH_LOST frame.

VAD flag: Boolean flag, generated by the VAD algorithm indicating the presence ("1") or the absence ("0") of a speech frame.

RX_TYPE: classifies the received frame.

TX_TYPE: classifies the frame to be transmitted.

hangover period: A period of frames added at the end of a speech burst in which VAD flag ="0" and TX_TYPE is ="SPEECH_GOOD", this period provides the encoder with an extra window to derive the Comfort Noise parameters .

3.2 Symbols

For the purpose of this document, the following symbols apply.

Nelapsed Number of elapsed frames since the last updated SID frame.

3.3 Abbreviations

For the purpose of this document , the following abbreviations apply.

AN Access Network

SCR Source Controlled Rate operation

TS Telecommunication Standard, Technical Specification

GSM Global System for Mobile Telecommunication

UE User Equipment

RAN Radio Access Network

RX Receive

SID Silence Descriptor

TX Transmit

VAD Voice Activity Detector