Sp-3-4350. 120-rv3 (to become ansi/tia-470. 120-C) Draft 22a ast ballot Comments with track changes on Telecommunications Telephone Terminal Equipment Transmission Requirements for Analog Speakerphones
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- 2NORMATIVE REFERENCES
- 3Abbreviations, Acronyms, AND definitions
- 3.2Definitions
1SCOPEThis standard provides speakerphone acoustic performance requirements for Customer Premises Equipment (CPE) intended for analog connection to the Public Switched Telephone Network (PSTN). These requirements should ensure compatibility and satisfactory performance to the user in a high percentage of installations. Test measurement methods reference procedures in IEEE Std 1329 where applicable. This document proposes or references at least one measurement procedure for each technical requirement. However, these procedures are not exclusive. Any measurement procedure and equipment that can result in an identical measurement is considered valid. While the procedures may call out specific test points within the requirements, the full range of the requirements take precedent. This standard is primarily intended to be used for evaluating single user speakerphones normally used at a distance of one half meter or closer. These requirements are not intended for Cordless handset speakerphones or multi-user conference speakerphones. 2NORMATIVE REFERENCESThe following standards contain provisions, which, through reference in this text, constitute provisions of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. ANSI and TIA maintain registers of currently valid national standards. ANSI/IEEE Std 1329-1999 – Standard method for measuring transmission performance of handsfree telephone sets ANSI/IEEE Std 269-2002 – Standard methods for measuring transmission performance of analog and digital telephone sets, handsets and headsets ANSI S1.4-1983 (Reaff. 2006) – American National Standard Specification for sound level meters ANSI S1.12-1967 (Reaff. 1997) – American National Standard Specifications for Laboratory Standard Microphone ITU-T Recommendation O.41 (10/94) –Psophometer for use on telephone-type circuits ITU-T Recommendation P.50 (9/99) – Artificial Voices ITU-T Recommendation P.51 (8/96) – Artificial Mouth ITU-T Recommendation P.56 (3/93) – Objective Measurement of Active Speech Level ITU-T Recommendation P.79 (11/07) – Calculation of loudness ratings for telephone sets 3Abbreviations, Acronyms, AND definitions3.1Abbreviations and AcronymsFor the purposes of this standard, the following abbreviations and acronyms apply. ASL Active Speech Level AWG American Wire Gauge CPE Customer Premises Equipment ERP Ear Reference Point HATS Head And Torso Simulator MRP Mouth Reference Point OLR Objective Loudness Rating PSTN Public Switched Telephone Network PBX Private Branch Exchange RETP Receive Electrical Test Point RLD Receive Level Directionality RLR Receive Loudness Rating ROLR Receive Objective Loudness Rating (AST – proposal to delete Annex E, see annex for details) SDNR Signal-to-Distortion and Noise Ratio SETP Send Electrical Test Point SLR Send Loudness Rating SLRD Send Loudness Rating Directionality SOLR Sidetone Objective Loudness Rating (AST – proposal to delete Annex E, see annex for details) TOLR Transmit Objective Loudness Rating (AST – proposal to delete Annex E, see annex for details) 3.2DefinitionsFor the purposes of this standard, the following definitions apply. Artificial Mouth: A device consisting of a loudspeaker mounted in an enclosure having a directivity and radiation pattern similar to those of the average human mouth. (See ITU-T P.51) Active Speech Level (ASL): Long term average speech level which does not include pauses or silences. It is the time integral of the instantaneous power over the active time, divided by active time, in decibels relative to the appropriate reference. (See ITU-T P.56) dBA: Sound pressure level in decibels, relative to 210-5 Pa, using A-weighting. (See Annex A) dBm: Power level in decibels, relative to a power of 1 mW (milliwatt). dBmp Power level in decibels, relative to a power of 1 mW, using psophometric weighting. (See Annex A) dBPa: The sound pressure level, in decibels, of a sound is 20 times the logarithm to the base 10 of the ratio of the pressure of this sound to the reference pressure of 1 Pascal (Pa). Note: 1 Pa = 1 N/m2 dBSPL: The sound pressure level, in decibels, of a sound is 20 times the logarithm to the base 10 of the ratio of the pressure of this sound to the reference pressure of 2 X 10-5 N/m2 (0 dBPa corresponds to 94 dBSPL) dBV: Voltage level in decibels, relative to 1 volt rms. Mouth Reference Point (MRP): A point on the axis of the mouth simulator, 25 mm in front of the center of the equivalent lip plane. Off-Hook: The state of the CPE when the hook-switch is closed. Refers to the state of a particular CPE rather than the line state. On-Hook: The state of the CPE when the hook-switch is open. Refers to the state of a particular CPE rather than the line state. Off-hook noise: The internally generated noise of the telephone set. It is the psophometric weighted signal power delivered to a specified termination (SETP) in the absence of an acoustic input into the telephone set. Reference Triangle: The Reference Triangle is the physical dimensions for the placement of the measuring microphone face and the MRP plane of the artificial mouth from the device. The dimensions are 40cm horizontal, 30cm vertical, which provides a distance of 50 cm to the device, see Figure 1 and Figure 2. Reference Volume Control Setting 0 km (VC Ref 0km): The quietest volume control setting that produces a receive level of at least 65 dBSPL with a P.50 test level of -18 dBV with a 0 km artificial line. Reference Volume Control Setting 2.7 km (VC Ref 2.7km): The quietest volume control setting that produces a receive level of at least 65 dBSPL with a P.50 test level of -25 dBV with a 2.7km artificial line. Reference Volume Control Setting 4.6 km (VC Ref 4.6km): The quietest volume control setting that produces a receive level of at least 62 dBSPL with a P.50 test level of -32 dBV with a 4.6km artificial line. Speakerphone: A device that facilitates two-way voice communication between persons over the public switched telephone network without contacting the user’s head. Directory: standards standards -> Request for proposal contract form for the transit industry standards -> Indiana Academic Standards Resource Guide Grade 8 United States History – Growth and Development (to 1877) Updated April 2016 standards -> Us history Dictionary Based on the sc state Standards standards -> Integrating Standards Education into the Business School Curriculum standards -> Use of Sprint U301 3G/4g mobile Broadband usb device Installation standards -> International organisation for standardisation organisation internationale de normalisation standards -> Standards of Excellence standards -> Common Core State Standards for Mathematics (ccssm) Download 0.58 Mb. Share with your friends:
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