| Transmission characteristics for cordless and mobile digital terminals |
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This Recommendation provides audio performance requirements for portable digital cordless and mobile handsets and hands-free terminals. The requirements apply to narrow-band systems (3.1 kHz) regardless of the coding algorithm used in the terminal. Associated test methods are also given. Requirements are specified for the major electro-acoustic performance parameters affecting audio quality, including sending and receiving levels, frequency responses, noise, sidetone, stability, echo path and delay. The requirements given in the Recommendation should ensure satisfactory service quality in a high percentage of installations under normal conditions.Changes over the previous ITU-T Rec. P.313 (1999) are as follows:
• Specifications for hands-free terminals have been added. These requirements are intended for mobile terminals in the car environment.
• For handsets fitted with a volume control, the maximum weighted Terminal Coupling Loss (TCLw) requirement of handsets with a volume control has been established at not less than 40 dB for the higher gain settings above the nominal setting of the volume control.
• The receiving mask for handsets has been slightly modified to align with other mobile standards.
• Out-of-band singles requirement for handsets has been added.
• The Sidetone Masking Rating (STMR) requirement is modified. The STMR range is increased from 10 dB to 18 dB, to a range of 10 dB to 20 dB. Testing methods for handsets have been updated.This revision provides, for the first time, an ITU standard for transmission characteristics of hands-free mobile terminals. Changes in the handset requirements should improve quality and increase usage with updated testing methods. |
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| Citation: |
https://handle.itu.int/11.1002/1000/7301 |
| Series title: |
P series: Telephone transmission quality, telephone installations, local line networks
P.300-P.399: Voice terminal characteristics |
| Approval date: |
2004-05-14 |
| Provisional name: | P.CMT |
| Approval process: | AAP |
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Status: |
Superseded |
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Maintenance responsibility: |
ITU-T Study Group 12 |
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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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P Suppl. 31 (01/2025)
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Subjective quality evaluation of audiovisual communication in videotelephony services
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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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