The present document gives some guidelines to implement test methods and to evaluate the transmission quality of handsfree Mobile Stations (MSs). The normative characteristics and test methods for handsfree Mobile Stations (MSs are defined in GSM 03.50). The present document gives additional data.
It includes summaries of texts or contributions presented and discussed during the meetings of ad hoc group SMG2/03.50 on environmental conditions, speech processing and quality assessment for handsfree Mobile Station.
The items covered by this report are mainly.
Environmental conditions for handsfree Mobile Stations.
Speech processing techniques and consequences on delay.
Speech quality assessment for handsfree implementing acoustic echo cancellation and noise reduction.
The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
- References are either specific (identified by date of publication, edition number, version number, etc.) or non specific.
- For a specific reference, subsequent revisions do not apply.
- For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
I-ETS 300 245-3: "Integrated Services Digital Network (ISDN);Technical characteristics of telephony terminals; Part 3: Pulse Code Modulation (PCM) A-law".
ITU-T Recommendation G.113: "Transmission Impairments Quantisation Distortion".
ITU-T Recommendation G.114: "Transmission Impairments, Delay".
ITU-T Recommendation G.165: "Performances of Network Echo Cancellers".
ITU-T Recommendation G.167: "Performance of acoustic echo control devices".
ITU-T Recommendation G.711: "64 kbit/s Pulse Code Modulation (PCM)".
ITU-T Recommendation G.721: "32 kbit/s Adaptive Differential Pulse Code Modulation (ADPCM)".
ITU-T Recommendation G.728: "16 kbit/s Low Delay CELP".
ITU-T Recommendation G.729: "8 kbit/s ACELP".
ITU-T Recommendation G.731: "Echo".
ITU-T Recommendation P.50: "Artificial Voices".
ITU-T Recommendation P.58: "Head and Torso Simulator (HATS) for telephonometry".
ITU-T Recommendation P.340: "Transmission Characteristics of Handsfree Telephones".
ITU-T Handbook On Telephonometry: Geneva 1987.
GSM 03.50: "Digital cellular telecommunications system (Phase 2+); Transmission planning aspects of the speech service in the GSM Public Land Mobile Network (PLMN) system".
For the purposes of the present document, the following terms and definitions apply:
Terminal Coupling Loss (TCL):
frequency dependent coupling loss between the receiving port and sending port of a terminal due to:
Weighted Terminal Coupling Loss (TCLW):
acoustical coupling at the user interface;
electrical coupling due to crosstalk in the handset cord or within the electrical circuits;
seismic coupling through the mechanical parts of the terminal.
weighted Terminal Coupling Loss using the weighting of CCITT Recommendation G.122.
For the purposes of the present document, the following abbreviations apply:
Head and Torso Simulator
Mouth Reference Point
Receive Loudness Rating
Send Loudness Rating
Terminal Coupling Loss
Weighted Terminal Coupling Loss