3 Definitions, symbols and abbreviations

26.1323GPPRelease 17Speech and video telephony terminal acoustic test specificationTS

3.1 Definitions

For the purposes of the present document the terms narrowband, wideband, super-wideband and fullband refer to signals associated with the corresponding operating modes of the speech codecs specified in 5.2.

For the purposes of the present document, the terms dB, dBr, dBm0, dBm0p and dBA, shall be interpreted as defined in ITU-T Recommendation G.100 [51]; the term dBPa shall be interpreted as the sound pressure level relative to 1 pascal expressed in dB (0 dBPa is equivalent to 94 dB SPL).

A 3GPP softphone is a telephony system running on a general purpose computer or PDA complying with the 3GPP terminal acoustic requirements (TS 26.131[1] and 26.132).

For the purposes of the present document the term clock skew is defined as the difference between the clock of the device under test (CDUT) and the clock of the reference client (CREF). The skew of CDUT relative to CREF is defined in parts per million (PPM) as: (CDUT -CREF).106/ CREF.

For the purposes of the present document, the term electrical interface is defined as an analogue or digital access to an UE, which allows injecting and capturing signals electrically instead of through an acoustical interface. The interface can be either wired (analogue, digital) or wireless (digital). The purpose of this interface is to connect a separate device (typically a headset), which provides a receiver and transmitter for telephony.

3.2 Abbreviations

For the purposes of the present document, the abbreviations given in 3GPP TR 21.905 [47] and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in 3GPP TR 21.905 [47].

5GC 5G Core Network

ADC Analogue to Digital Converter

AMR Adaptive Multi Rate

CSS Composite Source Signal

DAC Digital to Analogue Converter

DRP Eardrum Reference Point

DTX Discontinuous Transmission

EEC Electrical Echo Control

EEP Ear Entrance Point

EL Echo Loss

ERP Ear Reference Point

EVS Enhanced Voice Services

FFT Fast Fourier Transform

G-MOS-LQOn Global (Overall) – Mean Opinion Score – Listening Quality Objective – Narrowband

G-MOS-LQOw Global (Overall) – Mean Opinion Score – Listening Quality Objective – Wideband

G-MOS-LQOfb Global (Overall) – Mean Opinion Score – Listening Quality Objective – Fullband

HATS Head and Torso Simulator

IMS IP Multimedia Subsystem

LSTR Listener Sidetone Rating

LTE Long Term Evolution

MRP Mouth Reference Point

MS Mobile Station

MTSI Multimedia Telephony Service for IMS

N-MOS-LQOn Noise (Background) – Mean Opinion Score Listening Quality Objective – Narrowband

N-MOS-LQOw Noise (Background) – Mean Opinion Score Listening Quality Objective – Wideband

N-MOS-LQOfb Noise (Background) – Mean Opinion Score Listening Quality Objective – Fullband

NR New Radio

OLR Overall Loudness Rating

PCM Pulse Code Modulation

PDA Personal Digital Assistant

POI Point of Interconnection (with PSTN)

PSTN Public Switched Telephone Network

RP Reference point (electrical or acoustical)

RLR Receive Loudness Rating

RMC Reference Measurement Channel

RMS Root Mean Squared

SLR Send Loudness Rating

S-MOS-LQOn Speech Signal Quality – Mean Opinion Score – Listening Quality Objective – Narrowband

S-MOS-LQOw Speech Signal Quality – Mean Opinion Score – Listening Quality Objective – Wideband

S-MOS-LQOfb Speech Signal Quality – Mean Opinion Score – Listening Quality Objective – Fullband

SS System Simulator

STMR Sidetone Masking Rating

SS System Simulator

TX Transmission

TCL Terminal coupling loss

TCLw Terminal coupling loss (weighted)

USB Universal Serial Bus

USB-C USB Type-C connector/socket

UE User Equipment

UMTS Universal Mobile Telecommunications System

WLAN Wireless Local Area Network