1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU E.1801Q.35 (03/98) SERIES E: OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS Operation, numbering, routing and mobile services - I nternational operation - Tones in national
2、signalling systems SERIES Q: SWITCHING AND SIGNALLING International automatic and semi-automatic working - Tones for use in national signalling systems Technical characteristics of tones for the telephone service ITU-T Recommendation E.? 801Q.35 (Previously CCITT Recommendation) COPYRIGHT Internatio
3、nal Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesSTD*ITU-T RECMN E-180-ENGL 1998 48b259L Ob47040 Tb7 ITU-T E-SEMES RECOMMENDATIONS OVERALL NETWORK OPERATION, TELEPHONE SERVICE, SERVICE OPERATION AND HUMAN FACTORS 3PERATlON, NUMBERING, ROUTING AND MOBILE SER
4、VICES INTERNATIONAL OPERATION Definitions General provisions concerning Administrations General provisions concerning users Operation of international telephone services Numbering plan of the intemational telephone service International routing plan _ Tones signa Maritime mobile service and public l
5、and mobile service OPERATIONAL PROVISIONS RELATING TO CHARGING AND ACCOUNTING IN THE INTERNATIONAL TELEPHONE SERVICE UTILIZATION OF THE INTERNATIONAL TELEPHONE NETWORK FOR NON- TELEPHONY APPLICATIONS ISDN PROVISIONS CONCERNING USERS QUALITY OF SERVICE, NETWORK MANAGEMENT AND TRAFFIC ENGINEERING NETW
6、ORK MANAGEMENT TRAFFIC ENGINEERING QUALITY OF TELECOMMUNICATION SERVICES: CONCEPTS, MODELS, OBJECTIVES AND DEPENDABILITY PLANNING E. E. 00-E, 04-E. 03 19 E.120-E.139 E. 140-E. 159 E. 160-E. 169 E. 170-E. I79 E.180-E.199 E.200-E.229 E.330-E.399 For further details, please refer to ITU-T List of Recom
7、mendations. COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling Services STD-ITU-T RECMN E-180-ENGL 1998 H 48b2591 Ob47041 9T3 H ITU-T Q-SERIES RECOMMENDATIONS SWITCHING AND SIGNALLING SIGNALLING IN THE INTERNATIONAL MANUAL SERVICE INTERNATIONAL AU
8、TOMATIC AND SEMI-AUTOMATIC WORKING Basic Recommendations Numbering plan and dialling procedures in the international service Routing plan for international service General Recommendations relative to signalling and switching systems (national or international) national signaii General characteristic
9、s for international telephone connections and circuits Signalling for satellite systems Signalling for circuit multiplication equipment FWNCTIONS AND INFORMATION FLOWS FOR SERVICES IN THE ISDN CLAUSES APPLICABLE TO ITU-T STANDARD SYSTEMS SPECIFICATIONS OF SIGNALLING SYSTEMS No. 4 AND No. 5 SPECIFICA
10、TIONS OF SIGNALLING SYSTEM No. 6 SPECIFICATIONS OF SIGNALLING SYSTEM R1 SPECIFICATIONS OF SIGNALLING SYSTEM R2 DIGITAL EXCHANGES INTERWORKING OF SIGNALLING SYSTEMS SPECIFICATIONS OF SIGNALLING SYSTEM No. 7 DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1 PUBLIC LAND MOBILE NETWORK INTERWORKING WITH SATELL
11、ITE MOBILE SYSTEMS INTELLIGENT NETWORK BROADBAND ISDN Q.l-Q.3 Q.4-Q.59 Q.4-Q.9 Q.10-Q.11 Q.12-Q. 19 Q .20-Q.34 Q.35-Q.39 Q.40-4.47 Q .4 8-Q .49 Q.50-Q.59 Q .60-Q. 99 Q.lOO-Q.119 Q. 1204.249 Q.250-Q.309 Q.310-Q.399 Q.400-Q.499 Q.500-Q.599 Q.600-Q.699 4.7004.849 Q.SSO-Q.999 Q. 1000-Q. 1099 Q.1100-Q.11
12、99 Q.1200-Q. 1999 Q.2000-Q.2999 Forfurther details, please refer to ITU-T List of Recommendations. COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling Services STD-ITU-T RECMN E=IiBO-ENGL 1998 4862593 06470ir2 83T ITU-T RECOMMENDATION E.1801Q.35 TE
13、CHNICAL CHARACTERISTICS OF TONES FOR THE TELEPHONE SERVICE Summary This Recommendation sets the limits and recommended values of cadences, frequencies and levels for tones used in the telephone service. Those technical characteristics are relevant either for audible tones applied within the network
14、or for those generated at the digital terminal equipment. Source ITU-T Recommendation E.180/Q.35 was revised by ITU-T Study Group 2 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 9th of March 1998. Recommendation E.180/Q.35 (03/98) i COPYRIGHT International Telecommuni
15、cations Union/ITU TelecommunicationsLicensed by Information Handling ServicesSTDmITU-T RECMN E-LBO-ENGL 1998 4Bb2591 Ob47043 77b FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommuni- cations. The IT Telecommunication Standardizatio
16、n Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), w
17、hich meets every four years, establishes the topics for study by the IT-T Study Groups which, in their turn, produce Recommendations on these topics. The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1. In some areas of informati
18、on technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency.
19、INTELLECTUAL PROPERTY RIGHTS The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Proper
20、ty Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However,
21、implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. O ITU 1998 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, includin
22、g photocopying and microfilm, without permission in writing from the ITU. 11 Recommendation E.lSO/Q.35 (03/98) COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling Services1 2 3 4 5 6 7 8 9 10 11 12 STD-ITU-T RECMN E-180-ENGL 1998 4662591 Ob47044 60
23、2 CONTENTS General . Electrical levels for tones . Acoustical levels for tones . Dial tone . Ringing tone . Busy tone and congestion tone . Warning tone to indicate that a conversation is being recorded . Payphone recognition tone . 9.3 Duration and level . Call waiting tone Caller waiting tone . Ma
24、chine recognition of tones . Special information tone hex A Digital generation of tones Annex B Examples for limitation of spurious components of the dial tone with respect to interference with the frequencies recommended for pushbutton telephone sets in Recommendation 4.23 B.1 Method A (used by ATT
25、) . B.2 Method B (used by the Federal Republic of Germany) Recommendation E.180/Q.35 (03/98) Page 1 1 2 3 3 4 6 6 6 7 7 7 8 8 9 9 9 . 111 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesRecommendation E.1801Q.35 TECHNICAL CHARACTERISTIC
26、S OF TONES FOR THE TELEPHONE SERVICE (revised in 1998) 1 General Administrations are reminded of the advantages of standardizing audible tones as far as possible so that subscribers and operators may quickly recognize any tone transmitted of whatever origin2. Guidance on the application of tones and
27、 recorded announcements in various situations is given in Recommen- dation E.182. In considering the degree of standardization, the ITU-T took account of the nature of the various tones already in use. It was also considered that Administrations introducing new tones would find it helpful to know th
28、e preferred limits of cadence, frequency and level. Limits for tone cadences and frequencies are set forth below, all working tolerances being included in the limits. Besides the limits applying to specifications, limits have been laid down for application to existing exchanges. These latter limits
29、are herein called accepted limits, while those for new equipment are called recommended limits. The present Recommendation covers the case where audible tones are applied within the network. However, the same frequencies and cadences are to be applied if, in the ISDN, the audible tones are generated
30、 at the terminal equipment. All Administrations and operating agencies are requested to submit a concise technical description of any new or changed network tones to the ITU-T whenever such tones are introduced. The technical detail should include: level, frequencies, cadence, duty cycle, modulation
31、 and any other parameters that are required to fully describe the new or changed network tone. 2 Electrical levels for tones For international purposes, the levels of the ringing tonethe busy tone, the congestion tonethe special information tone and the warning tonehave to be defined at a zero relat
32、ive level point at the incoming (in the traffic direction) end of the international circuit. The level of tones so defined must have a nominal value of -10 dBmO. The recommended limits should be not more than -5 dBmO nor less than -15 dBmO measured with continuous tone. For the special information t
33、one, a difference in level of 3 dB is tolerable between any two of the three frequencies which make up the tone. For the power level of the dial tone, the point of reference is the local exchange, where the subscriber line is connected. In the existing networks the absolute power at the 2-wire acces
34、s in the direction towards the subscriber station is normally in the range of -10 dBm k 5 dB. However, with respect to interference with Multifrequency Pushbutton (MFPB) receivers dial tone levels higher than -10 dBm should be avoided. See Supplement No. 2 at the end of the Blue Book, Fascicle 11.2,
35、 for particular values of tone cadences and frequencies in actual use. Recommendation E. 181 specifies the information which could be given to users to facilitate recognition of foreign tones. * Recommendation E.180/Q.35 (03198) 1 COPYRIGHT International Telecommunications Union/ITU Telecommunicatio
36、nsLicensed by Information Handling ServicesNOTE - The relative level of local exchanges in an analogue network is not fixed. For digital local exchanges the relative levels are given in Recommendation 4.517. A preferred level range of digital tone generators is -8 dBmO to -3 dBmO corresponding with
37、the above level range at the output of local exchanges. 3 Acoustical levels for tones When tones are generated by a source within a network, e.g. by a telephone exchange, the power level as perceived by the user will be influenced by the characteristics of the subscribers line and the equipment betw
38、een the source and the users ear. Furthermore, tones can be generated within the users equipment, triggered by signals from the exchange. In these circumstances it is necessary to define the tone level in terms of the preferred range of sound pressure levels as heard by the listener. Research has sh
39、own that the preferred listening level for information tones is substantially independent of room noise, circuit noise and tone cadence, but does vary over a range of tone frequencies. Figure 1 shows the recommended sound pressure levels, with upper and lower limits of the recommended range, over a
40、range of tone frequencies, based on these experiments. dBPa dBrap 10 I l Upper limit of recommended 1 I04 I02 I O0 98 96 u - 94 g io (u (u - 92 90 88 86 84 200 300 400 500 600 700 800 1000 2000 Hz T0207440-98/601 Frequency Figure 1lE.180 - Recommended listening level limits for tones It is emphasize
41、d that there is no one-to-one relationship between electrical and acoustical power levels. What acoustic level will result from a given electrical level is dependent on various parameters such as the characteristics of the users equipment. It should be noted that the recommended sound pressure level
42、s apply only to the most common situation of a user listening via a telephone handset, held reasonably close to the ear so that normal “ear coupling loss“ values apply. When using a loudspeaking telephone or a headset, the preferred sound pressure level is generally lower than the recommended levels
43、. 2 Recommendation E.180/Q.35 (03/98) COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling Services- STD-ITU-T RECMN E-LBO-ENGL 1998 4Bb2591 Ob47047 311 4 Dial tone 4.1 It is recommended that dial tone should be a continuous tone. 4.2 It is recommen
44、ded that dial tone should be: - either a single frequency tone in the range 400-450 Hz; - or a combined tone composed of up to three frequencies, with at least one frequency in each of the ranges 340-425 Hz and 400-450 Hz. The difference between any two frequencies should be at least 25 Hz. 4.3 Reco
45、gnizing the local nature of “normal“ use of dial tone, as well as the technical and economic consequences and consequences on customer habits of changes in dial tone, the full range of existing dial tones, including non-continuous tones as in Supplement No. 2 at the end of Blue Book, Fascicle 11.2,
46、are considered acceptable. However, when adopting a new single frequency dial tone, Administrations are recommended to use 425 Hz. 4.4 recommended for analogue generated tones (see Annex A). Where digital tone generation is applied, the frequencies for dial tone should be the same as those 4.5 In or
47、der to prevent interference of harmonics or spurious components of the dial tone with the frequencies recommended for pushbutton telephone sets in Recommendation 4.23 and the MFPB signal reception specified in Recommendation 4.24, the maximum permissible power level of harmonics or quantizing noise
48、of the dial tone has to be limited in a suitable way, depending on the specific characteristics of the implementations of the dial tone generator and the MFPB receivers within the same exchange. Examples of such limitations for the dial tone generator are given in Annex B. NOTE - In cases of digital
49、 generation of the dial tone, the quantizing noise is composed of a number of spectral lines which depend on the number of samples in the generating pattern. In order to reduce the amplitude of the quantizing components, the number of samples should be chosen sufficiently high, thus spreading the quantizing distortion power more evenly over the whole spectnim. 5 Ringing tone 5.1 Ringing tone is a slow period tone, in which the tone period is shorter than the silent period. The recommended limits for the tone period (including tolerances) are from 0.67 to 1.5 seconds.
