IEEE Std 269-2010 IEEE Standard Methods for Measuring Transmission Performance of Analog and Digital Telephone Sets, Handsets, and Headsets.pdf
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1、? ? ?200? ? ? ? ?!? ? ?“?#?$?#? $? ?%? +1 978 750 8400. Permission to photocopy portions of any individual standard for educational classroom use can also be obtained through the Copyright Clearance Center. Authorized licensed use limited to: Tsinghua University Library. Downloaded on December 25,20
2、10 at 10:36:56 UTC from IEEE Xplore. Restrictions apply. iv Copyright 2010 IEEE. All rights reserved. Introduction This introduction is not part of IEEE Std 269-2010, IEEE Standard Methods for Measuring Transmission Performance of Analog and Digital Telephone Sets, Handsets, and Headsets. This stand
3、ard has been prepared in response to a widely expressed need by the telecommunications industry for a standard, comprehensive method for testing the transmission performance of telephone sets, handset, and headsets. The present standard is a revision of IEEE Std 269-2002. This revision adds coverage
4、 for a wide range of ear simulators and test signals, and incorporates and updates the contents of IEEE Std 1206-1994. Notice to users Laws and regulations Users of these documents should consult all applicable laws and regulations. Compliance with the provisions of this standard does not imply comp
5、liance to any applicable regulatory requirements. Implementers of the standard are responsible for observing or referring to the applicable regulatory requirements. IEEE does not, by the publication of its standards, intend to urge action that is not in compliance with applicable laws, and these doc
6、uments may not be construed as doing so. Copyrights This document is copyrighted by the IEEE. It is made available for a wide variety of both public and private uses. These include both use, by reference, in laws and regulations, and use in private self- regulation, standardization, and the promotio
7、n of engineering practices and methods. By making this document available for use and adoption by public authorities and private users, the IEEE does not waive any rights in copyright to this document. Updating of IEEE documents Users of IEEE standards should be aware that these documents may be sup
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9、n effect. In order to determine whether a given document is the current edition and whether it has been amended through the issuance of amendments, corrigenda, or errata, visit the IEEE Standards Association web site at http:/ieeexplore.ieee.org/xpl/standards.jsp, or contact the IEEE at the address
10、listed previously. For more information about the IEEE Standards Association or the IEEE standards development process, visit the IEEE-SA web site at http:/standards.ieee.org. Authorized licensed use limited to: Tsinghua University Library. Downloaded on December 25,2010 at 10:36:56 UTC from IEEE Xp
11、lore. Restrictions apply. v Copyright 2010 IEEE. All rights reserved. Errata Errata, if any, for this and all other standards can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/updates/errata/index.html. Users are encouraged to check this URL for errata periodically. Interpr
12、etations Current interpretations can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/interp/ index.html. Patents Attention is called to the possibility that implementation of this standard may require use of subject matter covered by patent rights. By publication of this stan
13、dard, no position is taken with respect to the existence or validity of any patent rights in connection therewith. The IEEE is not responsible for identifying Essential Patent Claims for which a license may be required, for conducting inquiries into the legal validity or scope of Patents Claims or d
14、etermining whether any licensing terms or conditions provided in connection with submission of a Letter of Assurance, if any, or in any licensing agreements are reasonable or non-discriminatory. Users of this standard are expressly advised that determination of the validity of any patent rights, and
15、 the risk of infringement of such rights, is entirely their own responsibility. Further information may be obtained from the IEEE Standards Association. Participants At the time this standard was submitted to the IEEE-SA Standards Board for approval, the subcommittee of the Transmission Access howev
16、er, no level compensation is required when speech or speech-like signals are used for receive measurements. For example, a narrow band codec will reduce the level of speech signals by less than 0.1 dB compared to the full bandwidth signal. The exact frequency range also depends on the analysis metho
17、d and the test signal (see G.6 and G.7). 5.6.2 Electrical test level The calibrated digital levels are 10 dBm0, 20 dBm0 and 35 dBm0. The calibrated analog levels are 14 dBV, 25 dBV, and 38 dBV closed circuit with generator load impedances of 900 resistive. Refer to Annex F for details about the deri
18、vation of electrical test levels. The standard test level for handsets and headsets tested as 4-wire devices is determined by the procedure for setting the default receive volume control adjustment in 8.3.2. For speech and other continuous spectrum test signals, the level shall be measured over the
19、entire spectrum. Out-of-band signals from 40 Hz to 20,000 Hz shall add no more than 0.5 dB to this level. Authorized licensed use limited to: Tsinghua University Library. Downloaded on December 25,2010 at 10:36:56 UTC from IEEE Xplore. Restrictions apply. IEEE Std 269-2010 IEEE Standard for Methods
20、Transmission Performance of Analog and Digital Telephone Sets, Handsets, and Headsets 22 Copyright 2010 IEEE. All rights reserved. 5.7 Mouth simulator The mouth simulator shall be calibrated prior to measurements. The measurement microphone used to calibrate the mouth simulator shall be calibrated f
21、irst (see 5.3). 5.7.1 Acoustic test spectrum The acoustic test spectrum is measured at the mouth reference point (MRP). The spectrum shall meet its target within 0.5 dB. Equalization may be used to meet this requirement. Typical targets can be the P.50 speech spectrum or the actual spectrum of the s
22、peech signal to be used. Annex E. The bandwidth of acoustical test signals shall not be reduced when testing narrow band or any reduced bandwidth device. The exact frequency range also depends on the analysis method and the test signal (see G.6 and G.7). 5.7.2 Acoustic test level The stimulus levels
23、 LMRP are as follows: Loud: +5 dBPa Nominal: 5 dBPa Quiet: 15 dBPa In this edition of the document, 5 dBPa is used as the nominal level. Previous editions of this document specified a nominal level of 4.7 dBPa. A nominal level of 4.7 dBPa is an acceptable alternative. Please see Annex F.6 for additi
24、onal information. Before performing tests at levels above 5 dBPa, verify the linearity of the mouth simulator. Some compression of the acoustic output of the mouth is normal at high levels. It may be necessary to perform a separate calibration of the mouth at high levels. When the mouth simulator is
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