Hands-Free Communication In Motor Vehicles By


ITU-T P.1100 & ITU-T P.1110 - IoV Application



PAL is a dedicated audio test lab and provides mobile vehicles test service that conformed to ITU-T P.1100 & P.1110

requirements. Our differentiations between others are:



a. Customizing your test 


PAL provides not only regular ITU-T P.1100/P.1110 tests but also some customizing test specifications. Customers may need to conduct testing follow some special requirements of some main operator specifications – like Apple CarPlay, Google Andriod Automotive, Microsoft Windows Embedded Automotive...etcs. PAL has capability to provide these kinds of customizing test service.



b. On-site debugging support 


PAL provides not only sample delivering test but also on-site debugging/witness test service. On-site testing is allowed during the test period. Customers will have chances to have comprehensive understanding of the test and then try to solve their issues sooner. 



c. Qualified Test Environment 


PAL has the qualified test environment for ITU-T P.1100/P.1110 test, including suitable background noise simulation system. We can evaluate your device performance in different driving conditions for the different requirement.



d. Complete Test Equipment 


1) Support both narrowband and wideband codecs.

2) Support 2G and 3G bands.

3) PAL has HATS (Head and Torso simulator) and the associated fixtures to support all product categories – Headset,

    and Handsfree.



e. Experienced engineers  


All tests will be conducted by our audio engineers instead of test operators. Customers have chances to get some recommendations and explanations during the test for free.





General introduction:


Ensure the quality of the speech quality of mobile vehicle system, ITU-T P.1100/P.1110 specification requirements demand to measure audio test items, in order to achieve quality control, to bring consumers a good experience, the following is the test items.


1. Delay

2. Loudness Rating

3. Sensitivity Frequency Response

4. Speech Quality During Single Talk

5. Listening Speech Quality Stability

6. Idle Channel Noise

7.Out-of-Band Signals

8. Distortion in Send/Receive Direction

9. Echo Performance Without Background Noise

10. Double Talk Performance

11. Background Noise Transmission 



Test Requirement



I. Delay: 


The delay in send direction is measured from the mouth reference point (MRP) to the point of interconnection (POI)

(reference speech codec of the system simulator, output). The delay in receive direction is measured from POI

(input of the reference speech coder of the system simulators) to the drum reference point (DRP).





II. Loudness Ratings: 


Mainly in the test sending\receiving path loudness rating, the sound of loudness affect the sound quality during

the call.  

a. Sending loudness rating (SLR) 

The purpose of the test item is to evaluate the microphone transmitted loudness, the loudness affect sound quality

during the call.  

b. Receiving loudness rating (RLR) 

The test project is to confirm the speaker volume to ensure that users have the appropriate volume to use.




III. Sensitivity Frequency Response: 


a. SFR  

The ratio of artificial mouth input sound pressure transmission microphone to voice codecs (codec) of output voltage.  

b. RFR 

The ratio of the amount of the artificial ear obtained by the sound pressure and the input voltage of the codec.




IV. Speech Quality during Single Talk:


To ensure that the call quality during the call in the simulated network condition is not degraded by device or interaction

with vehicle environment. Evaluating the following speech quality criteria is in focus for this test: 

a. Voice Activity Detection  

b. Voice Enhancement Devices  

c. Noise Reduction 

d. Discontinuous Transmission 




V. Listening Speech Quality Stability: 


Listening quality stability during a call (if the position or transmission characteristics change during the call (or during

several different calls) takes account degradations generated on the signal by the transmission link impairment and

the phone position.




VI. Idle channel noise: 


This test is used to evaluate the phone itself receiving \ sending noise.

All tests are conducted with average RF-signal power settings. It is recommended to check the requirement, in addition

with different RF-power settings. The requirement should be fulfilled for all RF-power settings.


a. Sending 

This test is used to assess the phone's sending path noise. The maximum noise level produced by the apparatus at the

output of the system simulator under silent conditions in the sending direction shall not exceed -64 dBm0(A) . 


b. Receiving 

This test is used to assess the phone's receiving path noise.

The maximum noise level at handset and headset user equipment when no signal is transmitted to the input of the system

simulator at the maximum volume the measured noise shall be under -53 dBPa(A).




VII. Out-of-band Signals: 


a. Sending 

If out-of-band signals are generated at the MRP, they are transmitted to the terminal and possibly to the input of the

speech decoder. For signals that are measured at the output of the speech decoder at the electrical reference point (POI)

For the measurement, a noise signal band-limited in the out-of-band frequency range is used. The total level, measured in a

frequency range interested, is measured at the electrical reference point (POI) and shall be less than 35 dB referred to the

reference level. 


b. Receiving 

The test signal used is speech sequence described in clause 7.3.2 of [ITU-T P.501], band-limited in the out-of-band

frequency range is used in the receive direction. The level of the out-of-band signal is measured in a frequency range

interested at the hands-free loudspeaker and shall be at least 45 dB.




VIII. Distortion in Send/Receive Direction: 


Mainly to test sending \ receiving distortion of processing sound signals.


a. Sending: 

The sending part shall be measured between MRP and system simulator audio. 


b. Receiving: 

The sending part shall be measured between DRP and system simulator audio.




IX. Echo Performance without Background Noise: 


Due to the expected delay in networks, the echo loss presented at the electrical reference point (POI) should be at least 50 dB during single talk. This echo loss (TCLW) should be achieved for a wide range of acoustical environments and delays.  




X. Double Talk Performance: 


During double talk, the speech is mainly determined by two parameters: impairment caused by echo during double talk and level variation between single and double talk (attenuation range). In order to guarantee sufficient quality under double talk conditions, the talker echo loudness rating should be high and the attenuation ed should be as low as possible. Terminals which do not allow double talk in any case should provide good echo attenuation which is realized by a high attenuation range in this case.




XI. Background Noise Transmission: 


For sending path, in handset mode, the user equipment shall reduce the ambient noise picked up by microphone without significantly degrading the quality of the speech signal. This test item mainly measure and analyze at different background noise environment, showing the transmitting end sound quality, sound quality is divided three MOS test. 


a. N-MOS: Transmission quality of the background noise.   

b. S-MOS: Transmission quality of the speech.  

c. G-MOS: Overall transmission quality.