1、RECMN*N.LO (REV*L) 93 D 48b259L O582862 072 = INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU MAINTENANCE OF INTERNATIONAL TRANSMISSION CIRCUITS SOUND-PROGRAMME AND TELEVISION N.1 O (03/93) LIMITS FOR THE LINING-UP OF INTERNATIONAL SOUND-PROGRAMME LINKS AN
2、D CONNECTIONS ITU-T Recommendation N.l O (Previously “CCITT Recommendation”) ITU-T RECMN*N.LO (REV*L) 93 = 4862593 0582863 TO9 FOREWORD The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecom- munication Union. The ITU-T is responsible for studying
3、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), which meets every four years, established the topics for study by the ITU-T Study Groups
4、which, in their turn, produce Recommendations on these topics. ITU-T Recommendation N.10 was revised by the ITU-T Study Group IV (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). NOTES 1 As a consequence of a reform process within the International Telecommunication Union (ITU),
5、 the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector. In order not to delay publication of
6、 this Recommendation, no change has been made in the text to references containing the acronyms “CCITT, CCIR or ERB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure. 2
7、 telecommunication administration and a recognized operating agency. In this Recommendation, the expression “Administration” is used for conciseness to indicate both a O ITU 1993 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or
8、 mechanical, including photocopying and microfilm, without permission in writing from the ITU. CONTENTS Page Abstract . 11 Keywords . 11 1 General . 1 2 Limits for the loss/frequency distortion of an international sound-programme link 1 References . 6 Recommendation N.10 (03/93) i ABSTRACT This Reco
9、mmendation gives limits for the line-up of international sound-programme links and connections using bandwidths of 5,6.4,7,10 and 15 kHz carried on analogue transmission systems, and for 7 and 15 kJ3z carried on mixed analogue/digital or digital systems. Keywords Sound-programme, line-up, limits, li
10、nks, circuits, connections, hypothetical reference circuit. ii Recommendation N.10 (03/93) ITU-T RECMN*N-LO (REV*3) 93 4862593 0582866 738 Recommendation N.10 LIMITS FOR THE LINING-Up OF INTERNATIONAL SOUND-PROGRAMME LINKS AND CONNECTIONS Published 1964; revised 1968,1972,1976,1980,1984 and 1993) 1
11、General This Recommendation gives limits in Tables 1 to 5 for the lining-up of international sound-programme links as defined in Recommendation N.1 5. These limits correspond to those for three audio sections of the hypothetical reference circuit as defined in Recommendation J. 11 11. It is not poss
12、ible at the present time to recommend limits for the sound-programme connection. However, Administrations shall endeavour to provide national sound-programme circuits to as high a standard as possible so that the performance of the sound-programme connection is not markedly different to that of the
13、sound-programme link Some Administrations arrange their apparatus in an International Sound-Programme Centre (ISPC) so that at the point of interconnection the output impedance of every receive channel or circuit over the frequency band of interest is substantially lower than the input impedance of
14、any send channel or circuit. This is the so-called constant-voltage technique. Other Administrations arrange for an impedance match at the point of interconnection and choose the value of this impedance to be equal to the design resistance of measuring instruments. This is known as the impedance- ma
15、tching technique (previously referred to as the constant electromotive force technique). It should be noted that in both cases the through-level measurement results relative to the through-level at 800 Hz will be the same. Furthermore the terminated-level measurement results relative to the terminat
16、ed-level at 800 Hz will also be the same valuel). Hence the limits recommended in the following tables are applicable regardless of the arrangement adopted by Administrations at their ISPCs. This Recommendation is applicable to analogue, mixed analogue/digital and digital transmissions. In the case
17、of digital transmission performance can be expected to be better than these limits. The test procedures are described in Recommendation N.21 7. 2 Limits for the loss/frequency distortion of an international sound-programme link The majority of international sound-programme links are in practice esta
18、blished with three or less circuits in series. Many links could be established without additional equalizers but links comprising four or more circuits will probably require equalization. In this case the opportunity could again be taken to obtain as good a loss/frequency characteristic as possible.
19、 l) This depends on the almost constant ratio of the impedances on the send and receive sides at the various frequencies (see4M.11 6.) Recommendation N.10 (03/93) 1 48b25L 0582867 654 m TABLE 1N.10 Limit for the lining-up of 15 kHz sound-programme links Item Limits Parameter unit Insertion gain Adju
20、stment error dB Variation dB 0.04 to O. 125 kHz dB dB 0.125 to 10 kHz dB f 0.5 1 f 0.5 + 0.5 - 2.0 f 0.5 Gain/frequency response referred to 0.8 or 1 kHz f 0.5 2 10 to 14 kHz - 2.0 I+ 14 to 15 kHz + 0.5 - 3.0 I 0.04kHz I ms 55 0.075 kHz Group delay/frequency response referred to minimum group delay
21、24 8 3 12 - 42 4 Weighted noise - 30 - 73 5 6 Disturbing modulation by power supply I dBmOs - 45 1 .o 7 I 0.04 to 0.125 kHz Total harmonic distortion I 0.125 to 7.5 kHz 1% 0.5 8 9 3rd order difference tone at O. 18 kHz % Error in reconstitued frequency Hz 0.5 f 1.0 50 0.04 kHz dB intelligible crosst
22、alk ratio 0.5 to 5 IcHz dB 10 74 60 11 f 0.5 Error in amplitude/amplitude response dB dB I 0.04 to 0.125 kHz 1.5 Difference in gain between A and B channels 0.8 0.125 to 10 kHz 10 to 14 kHz 12 1.5 Additional parameters for stereo transmission 14 to 15 kHz dB 0.04 to 0.2 kHz Degree 3.0 30 15 0.2 to 4
23、 kHz Degree Degree Phase difference between A and B channels 13 30 40 50 14 15 Intelligible crosstalk ratio Ah3 dB Crosstalk ratio (intermodulation) Ai dB GO Recommendation N.10 (03/93) 2 Parameter Unit Limits Adjustment error dB & 0.5 dB k 1.7 0.2 to 6 kHz dB f 1.7 0.05 kHz dB - 4.3 ms 80 Single to
24、ne interference level + dBmOs - 71 Disturbing modulation by power supply t dBmOs - 45 0.1 to 10 kHz 3rd order difference tone at O. 18 kHz % % Error in reconstituted frequency intelligible crosstalk ratioc) Hz dB Item 1 Insertion gain I dB Variation with time & 0.5 0.05 to 0.1 kHz dB I - 4.3 H - 2.6
25、 0.1 to 0.2 kHz Gdfrequency response referred to 0.8 or 1 kHz 2 4 6t08kHz + 1.7 8 to 10 kHz 3 Group delay/frequency response referred to minimum ms I 0.1 kHz 20 ms I 10 kJ3z 8 4 Weighted noise (idle channelp) - 39 5 6 7 Total harmonic distortion 3 I % I 0.05 to 0.1 kHz 2 8 2 9 fl 10 74 11 Error in a
26、mplitude/amplitude response I dB f 0.5 a) b) c) For circuits on carrier systems it is not always possible in absence of special precautions to meet these limits (see Annex BlJ.22 2). Or 20 dB below measured weighted noise level whichever is higher. It is in some cases difficult or impossible to meet
27、 these limits (see Note 2 of A.3NJ.22 2). Recommendation N.10 (03/93) 3 TABLE 3N.10 Limits for the iining-up of 7 kHz sound programme links Item 1 Parameter unit Limits Adjustment error dB f 0.5 Variation during 24 h dB f 0.5 Insertion gain dB +1 0.05 to 0.1 kHz I dB I -3 Gaidfrequency response refe
28、rred to 0.8 or 1 kHz 0.1 to 6.4 kHz f1 I dB 2 6.4 to 7 kHz -3 0.05 ICHz ms 80 0.1 kHz ms 20 Group delaylfrequency response referred to minimum 3 6.4 kHz ms 5 7 kHz ms 10 Idle channel dBqOps - 44 Programme-modulated dBqoPs - 32 4 Weighted noise 5 Single tone interference level + I dBmOs I -73 6 Distu
29、rbing modulation by power supply dBmOs I- 45 I 0.1 kHz 2 7 Total harmonic distortion 1.4 8 IC 3rd order difference tone at 0.18 kHz 1.4 9 Error in reconstituted frequency fl Hz I 53 0.05 kHz 0.5 to 3.2 IrHz 74 10 Intelligible crosstalk ratio 6.4 kHz dB 68 11 10.5 Error in ampiitude/ampiitude respons
30、e dB Recommendation N.10 (03/93) 5 I Item 1 2 3 4 5 6 7 8 9 10 11 TABLE 5M.10 Limits for the lining-up of 5 kHz sound programme links Parameter unit Limits Insertion gain Gaidfrequency response referred to 0.8 or 1 kHz Group delaylfrequency response referred to minimum Maximum weighted noise level I
31、 I Adjustment error dB f 0.5 Variation during 24 h dB f 0.5 0.7 to 0.2 kHz 0.2 to 4 kHz f1 4to5kHz 0.07 kHz ms 60 5 kHz ms 15 dBqOps I -32 I I I Single tone interference level + y dBmOs - 73 I Disturbing modulation by power supply Total harmonic distortion dBmOs -45 I I I 0.1 kHz % 1.4 3rd order dif
32、ference tone at 0.18 kHz I % I 1.4 I Error in reconstituted frequency Intelligible crosstalk ratio 0.5 to 3.2 kHz dB 74 5kHz dB 70 dB Error in amplitudehnpiitude response I f0.5 I References i CCK Recommendation J. 1 1 Hypothetical reference circuits for sound-programme transmissions. 2 3 CCK Recomm
33、endation 5.22 Performance characteristics of 10 kHz type sound-programme circuits. CCI Recommendation 503-3 Performance of 7 kHz type (narrow bandwidth) sound-programme circuits. 4 5 CCIR Recommendation 505-3 Performance characteristics of 15 kHz type sound-programme circuits. CCI“ Recommendation N.
34、 1 Definitions for applications to international sound-programme transmission. 6 CClT Recommendation N. 1 1 Essential transmission performance objectives for International Sound- Programme Centre (ISPC). 7 CCIT Recommendation N.21 Limits and procedures for the lining-up of a sound-programme circuit. 6 Recommendation N.10 (03/93)
