1、ETSI I-ETS8300 b77 9b 3400855 0148492 287 W IEL TELECOMMUNICATION STANDARD I-ETS 300 677 November I996 Source: ETSI TC-TE Reference: DI/TE-04004.1 ICs: 33.040.60 Key words: Acoustic, analogue, PSTN, telephony, terminal Public Switched Telephone Network (PSTN); Requirements for handset telephony ETSI
2、 European Telecommunications Standards Institute ETSI Secretariat Postal address: F-O6921 Sophia Antipolis CEDEX - FRANCE Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE X.400: c=fr, a=atlas, p=etsi, !+secretariat - Internet: secretariat etsi.fr Tel.: +33 4 92 94 42 O0
3、- Fax: +33 4 93 65 47 16 Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the foregoing restriction extend to reproduction in all media. Q European Telecommunications Standards Institute 1996. All rights reserved. ETSI I-ETS*300 677 96 3
4、400855 0348493 313 Page 2 I-ETS 300 67: November 1996 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 Committee Support Dept
5、.“ at the address shown on the title page. Page 3 I-ETS 300 677: November 1996 ETSI I-ETS*300 b77 96 3400855 0348494 05T. Contents Foreword . 5 Introduction 5 1 Scope 7 2 Normative references 7 3 Definitions and abbreviations 8 3.1 Definitions 8 3.2 Abbreviations . 8 4 Speech transmission aspects .
6、9 4.1 General 9 4.1.1 Polarity independence . 9 4.1.2 Feed resistance . 9 Speech performance characteristics . 10 4.2.1 Sensitivity - frequency response 10 4.2.1.1 Sending 11 Sending and Receiving Loudness Ratings 11 4.2.2.1 Sending Loudness Rating 12 4.2.2.2 4.2.3 Sidetone 14 4.2.4 Distortion . 15
7、4.2.4.1 Sending distortion 15 4.2.4.2 Receiving distortion . 15 4.2.4.3 Sidetone distortion . 15 4.2.4.4 Sending power-handling capability 15 4.2.4.5 Receiving power-handling capability 15 Linearity (variation of gain with input level) 15 4.2.5.2 Receiving . 15 Noise . 4.2.6 16 4.2.6.2 Receiving noi
8、se . 16 Echo return loss 16 4.2.7 4.2.8 Instability 16 4.1.3 Power supply . 10 4.1.4 Volume control 10 4.2 4.2.1.2 Receiving . 11 Receiving Loudness Rating . 12 4.2.2.3 Volume control . 13 4.2.2 4.2.5 4.2.5.1 Sending 15 4.2.6.1 Sending noise 16 5 Physical modules 16 5.1 Handset 16 Annex A (normative
9、): A.1 Maximum acoustically stimulated output 17 Maximum acoustically stimulated output . 17 Annex B (informative): Acoustic shock . 18 B.l.l Continuous signal 18 Annex C (informative): Immunity to out-of-band signalling 19 B.l General 18 B.1.2 Peak signal 18 ETSI I-ETSx300 677 96 m 3400855 0348495
10、Tb m Page 4 LETS 300 677: November 1996 C.1 Sending . 19 C.2 Receiving . 19 Annex D (informative): Additional requirement for dc characteristics . 20 D.l introduction . 20 D.2 Requirement . 20 Annex E (informative): Bibliography . 21 History . 22 ETSI I-ETSx300 b77 Yb = 3400855 OL484Yb 922 W Page 5
11、I-ETS 300 6: November 1996 Foreword ,This Interim European Telecommunication Standard (LETS) has been produced by the Terminal Equipment (TE) Technical Committee of the European Telecommunications Standards Institute (ETSI). An ETSI standard may be given LETS status either because it is regarded as
12、a provisional solution ahead of a more advanced standard, or because it is immature and requires a “trial period“. The life of an LETS is limited to three years after which it can be converted into an ETC, have its life extended for a further two years, be replaced by a new version, or be withdrawn.
13、 Proposed announcement date Date of adoption of this I-ETS: 25 October 1996 Date of latest announcement of this LETS (doa): 28 February 1997 Introduction This LETS describes the requirements for handset telephony terminals intended for connection to the Public Switched Telephone Network (PSTN) as de
14、scribed in clause 1 (Scope). Test methods to verify conformance to this LETS are contained in an associated standard (I-ETS 300 480 2). It is recognized that for historical reasons, feed resistances for test purposes, send and receive loudness and for sidetone may have values particular to each coun
15、trys network. These requirements are specified in a common text which, where necessary, includes parameters to which each country may assign its own national values, which are set out in accompanying tables. ETSI has derived tentative values for send and receive loudness ratings and for sidetone per
16、formance which are currently believed to be reasonable targets for handset telephony requirements in the future, when inter-exchange connections are mostly digital and the only source of loss is in the local analogue access. The tentative values were derived from the long term objectives for Sending
17、 Loudness Rating (SLR) and Receiving Loudness Rating (RLR) as described in ITU-T Recommendation G.121, taking into account R and T pads assumed to be 7 dB and O dB respectively, and allowing for an average loss of 4 dB in each local connection due to either the local line or to additional attenuatio
18、n inserted in the local exchange in the case of connections with short lines. These values have been incorporated in the LETS as tentative values forming the basis of future harmonization. As a result of ongoing discussions, the final figures implemented in a telephony TBR may differ from those give
19、n in this I-ETS. The values given in the tables of national values have been derived by transposing existing national regulatory requirements into values that would be obtained by the new harmonized test methods contained in LETS 300 480 2. National Administrations were invited to endorse these new
20、national values. At Public Enquiry, this introduction stated that: “If national values are not provided, the national values presently marked “Not Available“ will be replaced by the proposed harmonized values in the published I-ETS“. Where national values were not provided following public enquiry,
21、the proposed harmonized values have been inserted and marked with an *. ETSI I-ETS*3OO 677 96 3400855 0348497 869 I Page 6 I-ETS 300 677: November 1996 (Blank page) Page 7 I-ETS 300 6: November 1996 ETSI I-ETSx300 b77 9b m 3400855 0348498 7T5 m 1 Scope This Interim European Telecommunication Standar
22、d (I-ETC) specifies those electro-acoustical characteristics that a handset telephony terminal should fulfil to ensure the minimum speech quality when communicating across the European Public Switched Telephone Networks (PSTNs). The objective of this I-ETS is to ensure interworking between Terminal
23、Equipment (TE) via the public network. This I-ETS applies in conjunction with the general requirements for PSTN access contained in ETS 300 O01 l. The requirements of this I-ETS are additional to those for connection to the two-wire interface of the PSTN specified in ETS 300 O01 I. The requirements
24、of this LETS provide real-time (live) two-way speech of a quality consistent with the ITU-T (CCITT) P-series of Recommendations. The testing specification for analogue handset telephony is specified in I-ETS 300 480 2. This LETS is applicable both to handset telephony terminals and the handset telep
25、hony function of a multi-function terminal. The following functions are outside the scope of this I-ETS: - hands free or loudspeaking function; - cordless telephony; - telephony for people with audio-related impairments (e.g. telephones with additional receive amplification as an aid for the hard of
26、 hearing); - telephony terminals designed for use in hostile environments; - key systems or Private Automatic Branch exchange (PABX) system dependent terminals; - telephones using non-linear or time variant signal processing techniques. 2 Normative references This LETS incorporates by dated or undat
27、ed 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 LETS only when incorporated i
28、n it by amendment or revision. For undated references the latest edition of the publication referred to applies. ETS 300 O01 : “Attachments to the Public Switched Telephone Network (PSTN); General Technical requirements for equipment connected to an analogue subscriber interface in the PSTN“. LETS 3
29、00 480: “Terminal Equipment (TE); Attachments to the Public Switched Telephone Network (PSTN); Testing specification for analogue handset telephony“. Page 8 ETSI I-ETS*300 b77 9b m 3400855 0148477 631 I-ETS 300 67: November 1996 3 Definitions and abbreviations 3.1 . Definitions For the purposes of t
30、his I-ETS, the following definitions apply: acoustic shock Any temporary or permanent disturbance of the functioning of the ear, or of the nervous system, which may be caused to the user of a telephone earphone by a sudden sharp rise in the acoustic pressure produced by it (from ITU-T Recommendation
31、 P.l O). artificial ear: A device for the calibration of earphones incorporating an acoustic coupler and a calibrated microphone for the measurement of sound pressure and having an overall acoustic impedance similar to that of the average human ear over a given frequency band (from ITU-T Recommendat
32、ion P.10, see annex E). handset: A combination of telephone microphone and receiver in a form convenient for holding simultaneously to mouth and ear, which, when in use, retains the microphone in a position fixed in relation to the receiver. handsfree function: A function whereby telephony transmiss
33、ion and reception is facilitated by the use of microphone(s) and loudspeaker(s) placed at a distance from the user. No handset is required to be used and normally the handset is not active. loudness rating: A measure, expressed in decibels, for characterizing the loudness performance of complete tel
34、ephone connections or of parts thereof such as sending system, line, receiving system (from ITU-T Recommendation P.10, see annex E). An increase in a loudness rating corresponds to a decreasing subjective impression of loudness and vice versa. loudspeaking function: A function whereby the incoming s
35、ignal is presented to the user) from loudspeaker(s) and the handset is used simultaneously for sending in its normal speaking position. Mouth Reference Point (MRP): Point 25 mm in front of and on the axis of the lip position of a typical human mouth (or artificial mouth) (from ITU-T Recommendation P
36、.l O). Not Mandatory (NM): Indicates that the requirement in the common text with which the table is associated is not subject to mandatory compliance testing in that country, and that no parameter value has been assigned to it. Sidetone Masking Rating (STMR): A rating whereby the perceived loudness
37、 of the sidetone attributable to a telephone is calculated as the loudness of the speech via the electrical path masked by the speech via the natural paths (bone conduction and leakage at the ear). 3.2 Abbreviations For the purposes of this I-ETS, the following abbreviations apply: emf. MRP NM PABX
38、PSTN RLR SLR SPL STMR TE electro motive force Mouth Reference Point Not Mandatory Private Automatic Branch exchange Public Switched Telephone Network Receiving Loudness Rating Sending Loudness Rating Sound Pressure Level SideTone Masking Rating Terminal Equipment Page 9 I-ETS 300 677: November 1996
39、ETSI I-ETSx300 b? Yb 3400855 OL48500 I183 4 Speech transmission aspects 4.1 General 4.1.1 Polarity independence The TE shall conform to the requirements of this LETS for both polarities of line feeding voltage. Compliance shall be checked by reversal of the d.c. voltage applied to the terminal under
40、 test between changes of test configuration. 4.1.2 Feed resistance Unless otherwise specified, tests shall be carried out over the following range of feed resistance chosen from those given in subclause 4.2 of LETS 300 480 2. Sending and receive sensitivity (response) and sidetone test “b“ shall be
41、carried out at the feed resistance values specified. Table 1 : Range of feed resistance for testing purposes I characteristics which in this case are the same. I ETSI I-ETS*300 677 96 = 3400855 0148501 OLT Page 10 LETS 300 677: November 1996 Upper limit 4.1.3 Power supply Frequency (Hz) dB relative
42、to arbitrary level 1 O0 -9 2 O00 +4 Where the terminal requires an additional power supply in order for the handset telephony function to operate, the requirements of this I-ETS shall be met with the power supply connected and operative. I 4.1.4 Volume control 4 O00 +4 8 O00 - 16 Unless stated othet
43、wise, the requirements apply for all positions of the user-controlled receiving volume control, if provided. Lower limit Compliance tests shall be carried out at the “nominal“ setting of the volume control as described in subclause 4.2.2.3 unless otherwise specified in the appropriate requirement. 3
44、00 - 14 2 000 -6 4.2 Speech performance characteristics I 3 400 I - 11 I Figure 1 : Sending sensitivityflrequency limits 4.2.1 Sensitivity - frequency response The requirements for sending and receiving sensitivity - frequency responses shall be met at the nominated value of Rf specified as “for res
45、ponse test“ in table 1. Page 11 I-ETS 300 67: November 1996 ETSI I-ETSx300 677 96 3400855 0348502 T5b Frequency (Hz) 1 O0 200 8 O00 300 Lower limit 1 O00 3 400 Upper limit 4 O00 4.2.1.1 Sending dB relative to arbitrary level - 10 +2 +2 - 18 -9 -7 * 12 The sending sensitivity, when plotted against fr
46、equency, shall be not greater than the upper limit and not less than the lower limit given in table 2 and shown in figure 1. Compliance shall be checked by the test described in subclause 4.2.1.1 of I-ETS 300 480 2. 4.2.1.2 Receiving The receiving sensitivity, when plotted against frequency, shall b
47、e not greater than the upper limit and not less than the lower limit given in table 3 and shown in figure 2. Additionally, the sensitivity at 8 kHz shall be at least 25 dB below the sensitivity at 1 kHz. Compliance shall be checked by the test described in subclause 4.2.1.2 of I-ETS 300 480 2. 5 O S
48、ensitivity dB rel. arbitrary zero -5 -10 -1 5 100 200 500 1000 2000 5000 10 000 Frequency (Hz) Figure 2: Receiving sensitivitylfrequency limits 4.2.2 Sending and Receiving Loudness Ratings The values shown in tables 4 and 5 are those measured at terminals A and B in figure 1 of LETS 300 480 2, and d
49、o not include any attenuation due to a local telephone line. ETSI I-ETS*IOO b? 9b M 3400855 0348503 992 Page 12 I-ETS 300 67: November 1996 4.2.2.1 Sending Loudness Rating The Sending Loudness Rating (SLR), expressed as a function of feed resistance Rf shall conform to the values shown in table 4. Compliance shall be checked by the test described in subclause 4.2.2.1 of LETS 300 480 2. Table 4: Sending Loudness Rating 4.2.2.2 Receiving Loudness Rating The Receiving Loudness Rating (RLR), expressed as a function of feed resistance Rf, shall conform the val
