Transmission characteristics for wideband digital handset and headset telephones |
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Recommendation ITU-T P.311 provides audio performance requirements for wideband (8000 Hz) handset and headset telephones.
Requirements and test methods are specified for the major audio transmission parameters affecting wideband audio, including sending and receiving levels, frequency response, noise, distortion, sidetone, stability, echo path and delay. Wideband audio represents a considerable departure from traditional narrow-band telephony, offering significantly improved quality.
Major changes over the previous version of this Recommendation (2005) are as follows:
– The structure of the Recommendation is modified, the objective measurement methods originally in Annex A have been transferred into the main body.
– In addition to sinusoidal and noise signals, speech-like stimulus signals as described in Recommendation ITU-T P.50 and Recommendation ITU-T P.501 are also recommended for the measurements.
– HATS method is used for better simulation of real telephone communication.
– Specific headset requirements are incorporated.
– Some technical requirements and related test methods have been modified based on the latest research, e.g., frequency response, distortion, STMR, D-factor, and delay. |
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Citation: |
https://handle.itu.int/11.1002/1000/11076 |
Series title: |
P series: Telephone transmission quality, telephone installations, local line networks P.300-P.399: Voice terminal characteristics |
Approval date: |
2011-03-01 |
Approval process: | AAP |
Status: |
In force |
Maintenance responsibility: |
ITU-T Study Group 12 |
Further details: |
Patent statement(s)
Development history
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ITU-T Supplement
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Title
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Status
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Summary
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Table of contents
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Download
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P Suppl. 10 (11/1988)
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Considerations relating to transmission characteristics for analogue handset telephones
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In force
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-
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here
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here
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P Suppl. 16 (11/1988)
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Guidelines for placement of microphones and loudspeakers in telephone conference rooms and for group audio terminals (GATs)
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In force
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-
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here
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here
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P Suppl. 20 (03/1993)
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Examples of measurements of handset receive-frequency responses: dependence on earcap leakage losses
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In force
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-
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here
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here
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P Suppl. 23 (02/1998)
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ITU-T coded-speech database
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In force
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here
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here
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here
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P Suppl. 24 (10/2005)
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Parameters describing the interaction with spoken dialogue systems
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In force
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here
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here
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here
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P Suppl. 25 (01/2011)
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Parameters describing the interaction with multimodal dialogue systems
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In force
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here
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here
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here
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P Suppl. 26 (09/2017)
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Scenarios for the subjective evaluation of audio and audiovisual multiparty telemeeting quality
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In force
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here
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here
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here
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P Suppl. 28 (09/2020)
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Considerations for the development of new QoS and QoE related objective models to be embedded in Recommendations prepared by ITU-T Study Group 12
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In force
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here
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here
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here
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