1、ELECOMMUNICATION STANDARD FINAL DRAFT prl-ETS 300 245-3 November 1994 Source: ETSI TC-TE Reference: T/TE 10-07 (Cl UDC: 621.395 Key words: ISDN, telephony terminals Integrated Services Digital Network (ISDN); Technical characteristics of telephony terminals Part 3: Pulse Code Modulation (PCM) A-law,
2、 loudspeaking and handsfree telephony ETSI European Telecommunications Standards Institute ETSI Secretariat Postal address: 06921 Sophia Antipolis Cedex - FRANCE Office address: Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE Tel.: + 33 92 94 42 O0 - Fax: + 33 93 65 47 16 European Telecomm
3、unications Standards Institute 1 994. Ali rights reserved. No part may be reproduced except as authorised by written permission. The copyright and the foregoing restriction on reproduction extend to all media in which the information may be embodied. m 3404583 OL3b398 928 m Page 2 Final draft prl-ET
4、S 300 245-3: 1994 Whilst every care has been taken in the preparation and publication of this document, errors in content, typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to “ETSI Editing and Standards Approval Dept.“ at the address shown on the titl
5、e page. 3Li04583 Ol13b377 864 Page 3 Final draft prl-ETS 300 245-3: 1994 Contents Foreword . 7 1 Scope . 9 2 Normative references 9 3 Definitions and abbreviations 10 3.1 Definitions . 10 3.2 Abbreviations 10 4 Call control functions 11 5 Transmission aspects 11 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 Gener
6、al . 11 5.1.1 Encoding 11 5.1.2 Relative level 11 5.1.3 Volume control . 11 5.1.4 Requirements applicable to Hands-Free Telephone, Loudspeaking Telephony and Call Progress Monitoring . 12 Sensitivity frequency response . 13 5.2.2 Receiving . 13 5.2.1 Sending . 13 Loudness ratings 15 5.3.1 Sending .
7、15 5.3.2 Receiving . 15 5.3.2.1 Maximum sensitivity . 15 Volume control range 15 5.3.3 Adaptive gain control (optional) . 15 Terminal Coupling Loss (TCL) . 16 5.4.1 Hands-free function 16 5.4.2 Loudspeaking function . 16 5.4.3 Call Progress Monitoring (CPM) . 17 Stability loss 17 5.5.1 Hands free fu
8、nction . 17 5.5.2 Loudspeaking function . 17 Distortion 17 Harmonic distortion (sinusoidal signal) 17 5.6.1.1 Sending 17 5.6.1.2 Receiving 18 Total distortion (pseudo-random noise signal) 18 5.6.2.2 Receiving 18 Out-of-band signals 18 5.7.1 Sending . 18 5.7.2 Receiving . 19 5.8.1 Sending . 19 5.8.1.
9、1 Idle mode 19 5.8.2 Receiving . 20 5.3.2.2 5.6.1 5.6.2 5.6.2.1 Sending 18 Noise 19 5.8.1.2 Noise during transition from active mode to idle mode . 19 5.8.2.1 Idle mode 20 5.8.2.1.1 A-weighted 20 5.8.2.1.2 Third-octave band spectrum . 20 Noise during transition from active mode to idle mode . 20 5.8
10、.2.2 A.2.1 A.2.2 A.2.3 A.2.4 A.2.5 A.2.6 A.2.7 A.2.8 A.2.9 Page 4 Final draft prl-ETS 300 245-3: 1994 5.9 Delay . -20 Switching characteristics . 20 5.1 2 Articulation 21 Annex A (normative): Test specification 22 5.1 O 5.1 1 Acoustic Echo Controllers characteristics . 21 . A . 1 Test considerations
11、 22 A . 1 . 1 Test signals 22 A . 1.1 . 1 A . 1 . 1 . 2 A . 1 . 2 Test signal levels -23 A . 1 2.1 Sending 23 A . 1 2.2 Receiving 24 A.l . 3 Test rooms 24 A . 1 -3.1 A . 1.3.2 A.l . 4.1 A . 1 . 4.2 Broadband signal . 22 Sinusoidal and narrow-band signals 23 . . . Anechoic room 24 “Anechoic“ tests in
12、 a reverberant field . -27 Hands-free function 27 Loudspeaking function 27 Transmission requirements testing . 28 Sensitivity/frequency response 28 A.2.1 1 Sending 28 A . 1.4 Test arrangement 27 . A . 1 . 5 Alternative test methods. 28 A.2 . . A.2.1 . 2 A.2.2.1 A.2.2.2 Receiving 29 Loudness ratings
13、. 29 Sending Loudness Rating (SLR) 29 Receiving Loudness Rating (RLR) . -29 Terminal Coupling Loss 30 Stability loss 30 Distortion 30 Harmonic distortion (sinusoidal signal) 30 Sending . 30 Receiving -30 A.2.5.2.1 Sending . 31 A.2.5.2.2 Receiving -31 Out-of-band signals -31 A.2.6.1 Sending 31 A.2.6.
14、2 Receiving 31 A.2.7.1 Sending 31 A.2.7.1.1 Idle mode 32 A.2.7.2 Receiving 32 A.2.4.1 Hands-Free function . 30 A.2.4.2 Loudspeaking function 30 A.2.5.1 A.2.5.1.1 A.2.5.1 . 2 Total distortion (pseudo-random noise signal) . 31 A.2.5.2 Noise 31 A.2.7.1.2 Noise during the transition active mode to idle
15、mode 32 A.2.7.2.1 Idle mode 32 A.2.7.2.2 Noise during transition from active mode to idle mode 32 Delay 32 A.2.9.1 Switching characteristics . 33 Test signal levels . 33 . A.2.9.2 Build-up time . 33 A.2.9.3 Switching time 34 Echo cancelling characteristics 34 A.2.1 1 Articulation 34 A.2.10 Annex B (
16、informative): Description of the Composite Source Signal (CSSI 35 B.1 B.2 8.3 3404583 0336403 242 = Page 5 Final draft prl-ETS 300 245-3:1994 General presentation of the CSS . 35 Use of the CSS . 41 8.2.1 Calculation and analysis 41 B.2.1.1 B.2.1 . 2 Analysis parameters 41 Principles of testing appl
17、ied to annex A . 42 B.2.2.1 Measurements of frequency responses. TCL and Loudness Ratings, in single talk conditions . 42 B.2.2.2 Distortion measurements 42 B.2.2.3 Out-of-band measurements . 42 B.2.2.4 Noise measurements 42 B.2.2.5 Delay measurements 43 B.2.2.6 Switching characteristics 43 B.2.2.7
18、Echo cancelling characteristics 43 Principle of acoustical and electrical calibration - test signal levels 41 B.2.2 Practical Composite Source Signal . 43 B.3.1 Voiced signal to simulate voice properties 43 B.3.2 Pseudo noise signal 44 B.3.3 Pause . 44 Annex C (informative): Bibliography . 45 Histor
19、y 46 W 3404583 0136402 189 Page 7 Final draft prl-ETS 300 245-3: 1994 Foreword Part three of this final draft Interim European Telecommunication Standard (LETS) has been produced by the Terminal Equipment (TE) Technical Committee of the European Telecommunications Standards Institute (ETSI) and is n
20、ow submitted for the Voting phase of the ETSI standards approval procedure. An ETSI draft standard may be given I-ETS status either because it is regarded as a provisional solution ahead of a more advanced standard, or because it is immature and requires a “trial period“. The life of an I-ETS is lim
21、ited to three years after which it can be converted into an ETS, have its life extended for a further two years, be replaced by a new version or, be withdrawn. This is the third part of an I-ETS which is currently intended to comprise eight parts: Part 1: “General (I-ETS 300 245-1 111)“. Part 2: “PC
22、M A-Law, handset telephony (I-ETS 300 245-2 21)“. Part 3: “Pulse Code Modulation (PCM) A-Law, Loudspeaking and handsfree telephony“. Part 4: Interface for additional equipment. Part 5: Wideband (7 kHz) telephony. Part 6: Wideband (7 kHz) handsfree telephony. Part 7: Locally generated information ton
23、es. Part 8: Terminal application of 16 kbit/s speech coding algorithms (TRE 10-07H) NOTE: Part 8 to this LETS is still under study within ETSI. Proposed announcement date Date of latest announcement of this LETS (doa): 3 months after ETSI publication Previous page is blank - - 3404583 O336403 O15 W
24、Page 9 Final draft prl-ETS 300 245-3: 1994 1 Scope This third part of LETS 300 245 specifies technical characteristics for Pulse Code Modulation (PCM) A-law, 3,l kHz loudspeaking and handsfree telephony terminals to be used at the basic access for the coincident S and T reference point of the Integr
25、ated Services Digital Network (ISDN). Such terminals are intended to be used by a single person. This part of LETS 300 245 applies in conjunction with LETS 300 245-1 111 and the characteristics specified in this part are additional to those of I-ETS 300 245-1 111. 2 Normative references This LETS in
26、corporates, by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this
27、I-ETS only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to apply. i11 i21 I31 i41 i51 61 I-ETS 300 245-1 : “Integrated Services Digital Network (ISDN); Technical characteristics of telephony terminals, Part 1 : General“. LETS
28、 300 245-2: “Integrated Services Digital Network (ISDN); Technical characteristics of telephony terminals, Part 2: PCM A-law handset telephony“. ITU-T Recommendation P. 1 O f 1993): “Vocabulary of terms on telephone transmission quality and telephone sets“. CCITT Recommendation G.701 (1 988): “Vocab
29、ulary of digital transmission and multiplexing, and pulse code modulation (PCM) terms“. ETS 300 1 11 (1 992): “Integrated Services Digital Networks (ISDN); Telephony 3,l kHz teleservice, Service description“. CCITT Recommendation G. 122 (1 988): “Influence of national systems on stability, talker ec
30、ho, and listener echo in international connections“. i71 ITU-T Recommendation P.51 (1 993): “Artificial mouth“. 81 i91 i1 01 CCITT Recommendation G.711 (1 988): “Pulse code modulation (PCM) of voice frequencies“. ITU-T Recommendation P.34 (1 993): “Transmission characteristics of hands-free telephon
31、es“. CCITT Recommendation O. 131 (1 988): “Quantizing distortion measuring equipment using a pseudo-random noise test signal“. 11 11 IS0 266 (1 975): “Acoustics - Preferred frequencies for measurements“. i131 i141 ITU-T Recommendation P.79 (1 993): “Calculation of loudness ratings for telephone sets
32、“. CCITT Recommendation G.223 (1 988 1: “Assumptions for the calculation of noise on hypothetical reference circuits for telephony“. CCITT Recommendation 0.41 (1 988): “Psophometer for use on telephone- type circuits“. Previous page is blank 3404583 0336404 T5L Page 10 Final draft prl-ETS 300 245-3:
33、1994 t151 IEC 651 (1 979): “Sound level meters“. 3 Definitions and abbreviations 3.1 Definitions For the purposes of this part of the I-ETS, the relevant definitions given in ITU-T Recommendations P. 1 O 131 and G.701 141 apply along with the following: Acoustic Reference Level (ARL): The acoustic l
34、evel which gives - 1 O dBmO at the digital interface. telephony 3.1 kHz teleservice: A description of telephony 3,l kHz teleservice is given in ETS 300 111 151, clause 5. loudspeaking function: The handset is used in the normal position. The incoming signal is simultaneously presented to the user(s1
35、 from loudspeaker(s). hands-free function: For free handling no handset or any other equipment with transducers is held to the ear of the user. If a handset is implemented then it is placed at a distance from the user. Normally, the handset is not active. The numbers, the implementation and the use
36、of microphone(s1 and loudspeaker(s) are not limited. Call Progress Monitoring (CPM): The loudspeaker is used to monitor the received signals while the voice transmission in the sending direction is disconnected. Terminal Coupling Loss (TCL): The frequency dependent coupling loss between the receivin
37、g port and sending port of a terminal due to: - - - 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. NOTE 1 : The receiving port and the sending port o
38、f a digital voice terminal is a O dBr point. NOTE 2: The coupling at the user interface depends on the conditions of use. weighted Terminal Coupling Loss (TCLw): The Terminal Coupling Loss (TCL) calculated using the weighting of CCITT Recommendation G. 122 i61. Hands-Free Reference Point (HFRP): A p
39、oint located on the axis of the artificial mouth, at 50 cm from the lip ring, where the level calibration is made, in free field. It corresponds to the measurement point no 1 1, as defined in ITU-T Recommendation P.51 171. idle mode: Idle mode is when the terminal is not activated by an input signal
40、 (e.g. input signal level below implemented threshold level). active mode: Active mode is when the terminal is activated by an input signal (e.g. input signal level above implemented threshold level). single talk: An operation mode where only one user is speaking. double talk: An operation mode wher
41、e two users are speaking simultaneously 3.2 Abbreviations For the purposes of this part of the I-ETS, the following abbreviations apply: AEC AGC Ardt Acoustic Echo Controller Automatic Gain Control Received speech attenuation during double talk ARL Asdt CPM css ETS ETSI I-ETS ISDN FFT HATS HFRP HFT
42、LRGP LST MRP PCM PN RLR SLR TCL TCLw TCLwdt TCLwst Tondt Tonst TR TS Page 11 Final draft prl-ETS 300 245-3: 1994 Acoustic Reference Level Sent speech attenuation during double talk Call Progress Monitoring Composite Source Signal European Telecommunication Standard European Telecommunications Standa
43、rds Institute Interim European Telecommunication Standard Integrated Services Digital Network Fast Fourier Transformation Head And Torso Simulator Hands-Free Reference Point Hands-Free Telephony Terminal Loudness Rating Guard-ring Position Loudspeaking Telephony Terminal Mouth Reference Point Pulse
44、Code Modulation Pseudo Noise Receiving Loudness Rating Sending Loudness Rating Terminal Coupling Loss Weighted Terminai Coupling Loss Weighted Terminal Coupling Loss - double talk Weighted Terminal Coupling Loss - single talk Break in time - double talk Break in time - single talk Built up time Swit
45、ching time 4 Call control functions The requirements of LETS 300 245-1 l I shall be met. 5 Transmission aspects 5.1 General Requirements for PCM A-law terminals are given in this part of the I-ETS. When using other coding algorithms other parts of this I-ETS may apply. 5.1.1 Encoding The default spe
46、ech encoding algorithm for all speech terminals shall be the A-law encoding at 64 kbit/s, as defined in CCITT Recommendation G.71 1 i81. Any other possible encoding algorithm are additional. For some encoding algorithms, requirements are given in other parts of this I-ETS. 5.1.2 Relative level The d
47、igital interface is a O dBr point according to CCITT Recommendation G. 1 01. 5.1.3 Volume control Unless stated otherwise, the requirements apply for all positions of the user-controlled receiving volume control, if the volume control is manually operated. 3404583 0136406 824 = Sensitivity frequency
48、 response (5.2) Sending (5.2.1 1 Receiving (5.2.2) Loudness ratinas (5.3) Page 12 Final draft prl-ETS 300 245-3: 1994 X X X 5.1.4 Requirements applicable to t.dnds-Free Telephone, Loudspeaking Telephony and Call Progress Monitoring Sending (5.3.1 1 Receiving (5.3.2.1) Maximum sensitivity Receivina (
49、5.3.2.2) Volume control ranae Table 1 presents the requirements that shall be applicable to Hands-Free Telephony, Loudspeaking X X X X X Telephony and Call Progress Monitoring. The applicability is indicated by an “X“ in the corresponding column. The characteristics by “(X)“ are for further study. For Loudspeaking Telephony Terminals (LSTs), the requirements for handset telephony can in LETS 300 245-2 21. Receiving (5.3.3) Adaptive gain control (optional) Terminal coupling loss (5.4) - Handsfree Function (5.4.1) Table 1 : Applicability of requirements X X I I HFT I LST I CPM
