Recommendation ITU-T P.1140 (07/2022) Speech communication requirements for emergency calls originating from vehicles
Summary
History
FOREWORD
Table of Contents
1 Scope
2 References
3 Definitions
     3.1 Terms defined elsewhere
     3.2 Terms defined in this Recommendation
4 Abbreviations and acronyms
5 Conventions
6 Test set-up and preparation
     6.1 Test arrangement
     6.2 Background noise simulation in a car
     6.3 Positioning of the emergency call IVS
     6.4 Operation modes of emergency call IVS
     6.5 Artificial mouth
     6.6 Artificial ear
     6.7 Influence of the transmission system
     6.8 Calibration and equalization
          6.8.1 Calibration
          6.8.2 Equalization
          6.8.3 Reference measurement
     6.9 System simulator settings
          6.9.1 General
          6.9.2 Circuit-switched networks
          6.9.3 Packet-switched networks
     6.10 Environmental conditions
          6.10.1 Verification of environmental conditions
7 Test signals and test signal levels
     7.1 Signals
     7.2 Background noise signals
          7.2.1 Recording of background noise
          7.2.2 Playback of the recorded background noise
8 Measurement parameters and requirements for narrowband IVS terminals
     8.1 Preparation measurements
     8.2 Delay
          8.2.1 Requirements
          8.2.2 Delay in the send direction
               8.2.2.1 Test
          8.2.3 Delay in the receive direction
               8.2.3.1 Test
     8.3 Loudness ratings
          8.3.1 Requirements
          8.3.2 Test loudness rating in the send direction
          8.3.3 Test loudness rating in the receive direction
     8.4 Variation of RLR in the presence of background noise
          8.4.1 Requirements
          8.4.2 Test
     8.5 Sensitivity frequency responses
          8.5.1 Send sensitivity frequency response
               8.5.1.1 Requirements
               8.5.1.2 Test
          8.5.2 Receive sensitivity frequency response
               8.5.2.1 Requirements
               8.5.2.2 Test
     8.6 Speech intelligibility during single talk
          8.6.1 One-way speech intelligibility in send
          8.6.2 Speech intelligibility in receive
     8.7 Idle channel noise
          8.7.1 Idle channel noise in the send direction
               8.7.1.1 Requirements
               8.7.1.2 Test
          8.7.2 Idle channel noise in the receive direction
               8.7.2.1 Requirements
               8.7.2.2 Test
     8.8 Echo performance
          8.8.1 Terminal coupling loss (TCLw)
               8.8.1.1 Requirements
               8.8.1.2 Test
          8.8.2 Echo level versus time
               8.8.2.1 Requirements
               8.8.2.2 Test
          8.8.3 Echo performance with time variant echo path and speech
               8.8.3.1 Requirements
               8.8.3.2 Test
     8.9 Switching characteristics
          8.9.1 Activation in the send direction
               8.9.1.1 Requirements
               8.9.1.2 Test
     8.10 Double talk performance
          8.10.1 Attenuation range in the send direction during double talk: AH,S,dt
               8.10.1.1 Requirements
               8.10.1.2 Test
          8.10.2 Attenuation range in the receive direction during double talk: AH,R,dt
               8.10.2.1 Requirements
               8.10.2.2 Test
          8.10.3 Detection of echo components during double talk
               8.10.3.1 Requirements
               8.10.3.2 Test
          8.10.4 Robustness of double talk capability with far end background noise at the PSAP
     8.11 Background noise transmission
          8.11.1 Silent call performance
               8.11.1.1 Requirements
               8.11.1.2 Test
          8.11.2 Speech intelligibility in the presence of background noise
     8.12 Jitter buffer management
          8.12.1 Overview
          8.12.2 Requirements
          8.12.3 Test signal
          8.12.4 Delay and loss profiles
          8.12.5 Test
9 Measurement parameters and requirements for wideband IVS terminals
     9.1 Preparation measurements
     9.2 Delay
          9.2.1 Requirements
          9.2.2 Delay in the send direction
               9.2.2.1 Test
          9.2.3 Delay in the receive direction
               9.2.3.1 Test
     9.3 Loudness ratings
          9.3.1 Requirements
          9.3.2 Test loudness rating in the send direction
          9.3.3 Test loudness rating in the receive direction
     9.4 Variation of RLR in the presence of background noise
          9.4.1 Requirements
          9.4.2 Test
     9.5 Sensitivity frequency responses
          9.5.1 Send sensitivity frequency response
               9.5.1.1 Requirements
               9.5.1.2 Test
          9.5.2 Receive sensitivity frequency response
               9.5.2.1 Requirements
               9.5.2.2 Test
     9.6 Speech intelligibility during single talk
          9.6.1 One-way speech intelligibility in send
          9.6.2 Speech intelligibility in receive
     9.7 Idle channel noise
          9.7.1 Idle channel noise in the send direction
               9.7.1.1 Requirements
               9.7.1.2 Test
          9.7.2 Idle channel noise in the receive direction
               9.7.2.1 Requirements
               9.7.2.2 Test
     9.8 Echo performance without background noise
          9.8.1 Terminal coupling loss
               9.8.1.1 Requirements
               9.8.1.2 Test
          9.8.2 Echo level versus time
               9.8.2.1 Requirements
               9.8.2.2 Test
          9.8.3 Echo performance with time variant echo path and speech
               9.8.3.1 Requirements
               9.8.3.2 Test
     9.9 Switching characteristics
          9.9.1 Activation in the send direction
               9.9.1.1 Requirements
               9.9.1.2 Test
     9.10 Double talk performance
          9.10.1 Attenuation range in the send direction during double talk: AH,S,dt
               9.10.1.1 Requirements
               9.10.1.2 Test
          9.10.2 Attenuation range in the receive direction during double talk: AH,R,dt
               9.10.2.1 Requirements
               9.10.2.2 Test
          9.10.3 Detection of echo components during double talk
               9.10.3.1 Requirements
               9.10.3.2 Test
          9.10.4 Robustness of double talk capability with far end background noise at the PSAP
     9.11 Background noise transmission
          9.11.1 Silent call performance
               9.11.1.1 Requirements
               9.11.1.2 Test
          9.11.2 Speech intelligibility in the presence of background noise
     9.12 Jitter buffer management
          9.12.1 Overview
          9.12.2 Requirements
          9.12.3 Test signal
          9.12.4 Delay and loss profiles
          9.12.5 Test
Annex A  Alternative method for determining the roundtrip delay
Annex B  Void
Bibliography
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