Detail of YD/T 1538-2014

Introduction of YD/T 1538-2014

Technical requirements and test methods for acoustics performance of digital mobile terminal 1 Scope This standard specifies the technical requirements and test methods of acoustics characteristics when digital mobile terminals access GSM, TD-SCDMA, WCDMA or cdma2000 for voice communication. It is applicable to all kinds of digital mobile terminal equipment used to connect with public digital mobile networks, including but not limited to one or more of the above four systems. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced documents (including any amendments) applies. ITU-T G.223(11/1988) Assumptions for the calculation of noise on hypothetical reference circuits for telephony ITU-T G.711 Pulse code modulation (PCM) of voice frequencies ITU-T G.712(11/2001) Transmission performance characteristics of pulse code modulation channels ITU-T O.41 (10/1994) Psophometer for use on telephone-type circuits ITU-T O.131 (11/1988) Quantizing distortion measuring equipment using a pseudo-random noise test signal ITU-T P.50 (09/1999) Artificial Voice ITU-T P.51(08/1996) Artificial Mouth ITU-T P.57(12/2011) Artificial Ears ITU-T P.58(05/2013) Head and torso simulator for telephonometry ITU-T P.64(11/2007) Determination of sensitivity/frequency characteristics of local telephone systems ITU-T P.340(05/2000) Transmission characteristics and speech quality parameters of hands-free terminals ITU-T P.501(01/2012) Test signals for use in telephonometry ITU-T P.581(02/2014) Use of head and torso simulator (HATS) for hands-free and handset terminal testing   3 Abbreviations For the purposes of this document, the following abbreviations apply. ARL Acoustic Reference Level CF Crest Factor EEP Ear canal Entrance Point HATS Head and Torso Simulator HATS-HFRP HATS Hands-free Reference Point HFRP Hands-free Reference Point HFT Hands-free Terminal LR Loudness Rating MRP Mouth Reference Point SLR Sending Loudness Rating RLR Receiving Loudness Rating RWP Recommended Wearing Position RTP Recommended Test Position STMR Side Tone Mask Rating SS System Simulator TCLw Terminal Coupling Loss weighted ΔSm Ssi (diff) – Ssi (direct) POI Point of Interconnection (with PSTN) S-MOS LQOn Speech-Mean Opinion Score, Listening Quality Objective measurement in Narrow-band audio context N-MOS LQOn Noise-Mean Opinion Score, Listening Quality Objective measurement in Narrow-band audio context S-MOS LQOw Speech-Mean Opinion Score, Listening Quality Objective measurement in Wide-band audio context N-MOS LQOw Noise-Mean Opinion Score, Listening Quality Objective measurement in Wide-band audio context 4 Technical requirements of narrow-band audio 4.1 Sending sensitivity/frequency characteristics 4.1.1 Handle/head-mounted terminal The sending sensitivity/frequency characteristics measured from the mouth reference point to the output port of the reference coder/decoder of system simulator (SS) shall be within the range given in Table 1. On the logarithmic (frequency)/linear (dB sensitivity) coordinates, draw a straight line between the discontinuous points in Table 1 to get a range (as shown in Figures 1 and 2) within which there shall be the testing results.   Table 1 Sending sensitivity/frequency characteristics - Handle terminal .... ... Figure 3 Sending sensitivity/frequency characteristics template - Hand-held and desktop terminals 4.2 Receiving sensitivity/frequency characteristics 4.2.1 Handle/head-mounted terminal The receiving sensitivity/frequency characteristics measured based on the equalized scattering field from input port of the reference coder/decoder of system simulator (SS) to the drumhead reference point (DRP) shall be within the range given in Table 3. On the logarithmic (frequency)/linear (dB sensitivity) coordinates, draw a straight line between the discontinuous points in Table 3 to get a range (as shown in Figures 4 and 5) within which there shall be the testing results. Table 3 Receiving sensitivity/frequency characteristics - Handle terminal

Contents of YD/T 1538-2014

Foreword i 1 Scope 2 Normative references 3 Abbreviations 4 Technical requirements of narrow-band audio 4.1 Sending sensitivity/frequency characteristics 4.2 Receiving sensitivity/frequency characteristics 4.3 Sending loudness rating (SLR) 4.4 Receiving loudness rating (RLR) 4.5 Idle channel noise 4.6 Side tone performance 4.7 Acoustics echo control 4.8 Sending distortion 4.9 Receiving distortion 4.10 Signal quality under noise conditions (handle terminal) 4.11 Delay (handle/head-mounted terminal) 4.12 Echo control characteristics 5 Technical requirements of wide-band audio 5.1 Sending sensitivity/frequency characteristics 5.2 Receiving sensitivity/frequency characteristics 5.3 Sending loudness rating (SLR) 5.4 Receiving loudness rating (RLR) 5.5 Idle channel noise 5.6 Side tone performance 5.7 Acoustics echo control 5.8 Sending distortion 5.9 Receiving distortion 5.10 Signal quality under noise conditions (handle terminal) 5.11 Delay (handle/head-mounted terminal) 5.12 Echo control characteristics 6 Testing conditions 6.1 Environmental conditions 6.2 Testing equipment and signals 7 Narrow-band voice testing method 7.1 Sending sensitivity/frequency characteristics 7.2 Receiving sensitivity/frequency characteristics 7.3 Sending loudness rating (SLR) 7.4 Receiving loudness rating (RLR) 7.5 Idle channel noise 7.6 Side tone performance 7.7 Acoustics echo control 7.8 Sending distortion 7.9 Receiving distortion 7.10 Delay 7.11 Echo control characteristics 7.12 Signal quality under noise conditions 8 Wide-band voice testing method 8.1 Sending sensitivity/frequency characteristics 8.2 Receiving sensitivity/frequency characteristics 8.3 Sending loudness rating 8.4 Receiving loudness rating (RLR) 8.5 Idle channel noise 8.6 Side tone performance 8.7 Acoustics echo control 8.8 Sending distortion 8.9 Receiving distortion 8.10 Delay 8.11 Echo control characteristics 8.12 Signal quality under noise conditions