Voice quality Index

[gogotchiya83]

Hello,
Can someone explain for us the calculation of the VQI (voice quality index) process?
is it the same as MOS?
is it calculated on each TRX ...
any doc about that?

[giegala]

Hi,

it is similar to E/// SQI. Voice quality is estimated from FER, BER, Codec type, HO occurrence etc. U can enable feature to measure it by network in UL and DL. Personally i do not believe in UL measurements, because system does not take into account HO, furthermore UL usually is better than DL.

DL measurements by network is based on Enhanced Measurement Reports - MS does this thing. On hearsay level - EMR is no go on the network. Certain phones are getting big issues to operate on the network with EMR.

[gogotchiya83]

Tkx for your reply, we tried to enable this feature in some BSC but Huawei refused to activate it (even in BSC under Test) someone told me that this feature create some problems in network so Huawei it become forbiden to sell it...
Can you expalin for us what does it Mean EMR (Enhanced Measurement Reports)?
For us we are looking for some KPIs (from statistic) which can show for us the voice quality ? any idea about that?

[giegala]

yes, HW always acts in that way. Somewhere some idiots test something crazy, then everyone everywhere gets frightened and refuses even to touch it. Now we got UL VQI enabled for slightly less than a week. no big issues so far. will have a report next week. Check out print out from Hedex below.

As you know, MS report DL rxlev, rxqual and upto 6 nbrs in MR - which is old MR. EMR is a new way for the same business. In EMR such quanties as BEP and CV are reported. Check google for more indepth descriptions. also compare GPRS measurement reports - they include it from beginning. BEP and CV would allow estimation of FER -> VQI. Anyway some phones go crazy, when network has EMR enable, therefore it is no recommended. Personally i have not tried myself - it could be wrong.

As for voice quality, i suppose you have AoIP. in this case, all voice processing is done in MGW. The same applies for voice quality evaluation, because BSC does not have TC, which are used for voice processing.

Therefore only old time methods are available - RxQual distribution. our customer considers that rxqual6 and 7 means silence to customer and we should decrease the % of 6 & 7. In general we have faced rxqual issues for AMR calls. It seems there is in general issue with AMR and Huawei + phones using Infineon chipsets.



Configuring Voice Quality Index (VQI)
This section describes how to activate, verify, and deactivate the optional feature GBFD-116801 Voice Quality Index (VQI).

Prerequisites
Dependencies on Hardware
This feature does not have any special requirements for hardware.
Dependencies on Other Features
The feature GBFD-117501 Enhanced Measurement Report (EMR) has been configured before this feature is activated.
License
The license for this feature is activated.
Others Prerequisites

The cell is configured with neighboring cells.
The BTS of the cell supports downlink VQI.
Context
The VQI establishes the mapping between radio network performance and voice quality. The VQI value, which helps learn the voice quality, is calculated based on the radio quality parameters for the uplink and downlink speech signals. The MOS analysis method is applied in VQI to measure the voice quality. The MOS is used to assess the quality of middle-rate and low-rate voice coding. The MOS value ranges from 1 to 5.

Based on the MOS analysis method, Huawei further divides the voice quality into 11 levels. The VQI is obtained through the analysis of the BER, FER, LFE, and CODE of the uplink and downlink speech signals. In this manner, the voice quality is quantified to facilitate voice problem identification and network optimization.

Procedure
Activation Procedure

Activating downlink VQI
Run the BSC6900 MML command SET GCELLSOFT. In this step, set Report Downlink VQI Allowed to ENABLE(Enable).
NOTE:
VQI is recorded in a measurement report if only Report Downlink VQI Allowed is set to ENABLE(Enable) and a voice service is processed. The downlink VQI value is 255 when the MS does not support enhanced measurement reports or Measurement Report Type is not set to EnhMeasReport(Enhanced Measurement Report).
Activating uplink VQI
Run the BSC6900 MML command SET GCELLOTHBASIC. In this step, set Voice quality report switch to YES(Report).

Verification Procedure

Verifying downlink VQI
Run the BSC6900 MML command SET GCELLSOFT. In this step, set Cell Index to the index of the cell to be verified and Report Downlink VQI Allowed to ENABLE(Enable). Perform a voice service test and check the downlink VQI value in the measurement reports.

Expected result: The downlink VQI value is not reported.

Run the BSC6900 MML command SET GCELLCCUTRANSYS. In this step, set Cell Index to the index of the cell to be verified and Measurement Report Type to EnhMeasReport(Enhanced Measurement Report).
NOTE:
You need to configure a neighboring GSM cell if no enhanced measurement report is obtained when enhanced measurement reports are configured and the MS in a voice service supports enhanced measurement reports.
Run the BSC6900 MML command SET GCELLCCACCESS. In this step, set Speech Version to one that matches the channel type. Speech versions are FULL_RATE_VER1(Full-rate VER 1), FULL_RATE_VER2(Full-rate VER 2), FULL_RATE_VER3(Full-rate VER 3), HALF_RATE_VER1(Half-rate VER 1), HALF_RATE_VER2(Half-rate VER 2), and HALF_RATE_VER3(Half-rate VER 3). Perform a voice service test and check the downlink VQI value in the measurement reports.

Expected result: The downlink VQI value is reported.

Run the BSC6900 MML command SET GCELLHOCTRL. In this step, set MR.Preprocessing to BTS_Preprocessing(BTS preprocessing) and Sent Freq.of preprocessed MR to an appropriate value based on the site requirements. Perform a voice service test and check the downlink VQI value in the preprocessed measurement reports.

Expected result: The downlink VQI value is reported.

Verifying uplink VQI
On the BSC6900 LMT, initiate CS domain message tracing of a single subscriber by referring to Tracing CS domain messages of a single subscriber. Perform a voice service test, and check the uplink VQI value in the measurement reports.

Expected result: The uplink VQI value is reported.

Run the BSC6900 MML command SET GCELLHOCTRL. In this step, set MR.Preprocessing to BTS_Preprocessing(BTS preprocessing) and Sent Freq.of preprocessed MR to an appropriate value based on the site requirements. Perform a voice service test and check the uplink VQI value in the preprocessed measurement reports.

Expected result: The uplink VQI value is reported.


Deactivation Procedure

Deactivating downlink VQI
Run the BSC6900 MML command SET GCELLSOFT. In this step, set Report Downlink VQI Allowed to DISABLE(Disable).
Deactivating uplink VQI
Run the BSC6900 MML command SET GCELLOTHBASIC. In this step, set Voice quality report switch to NO(Not report).

Example
//Activating downlink VQI
SET GCELLSOFT: IDTYPE=BYID, CELLID=1, RPTDLVQIALLOWED=ENABLE;
//Activating uplink VQI
SET GCELLOTHBASIC: IDTYPE=BYID, CELLID=1, RPTVOICE=YES;
//Verifying downlink VQI
SET GCELLSOFT: IDTYPE=BYID, CELLID=0, RPTDLVQIALLOWED=ENABLE;
SET GCELLCCUTRANSYS: IDTYPE=BYID, CELLID=0, MEASURETYPE=EnhMeasReport;
SET GCELLCCACCESS: IDTYPE=BYID, CELLID=0, VOICEVER=FULL_RATE_VER1-1&FULL_RATE_VER2-1&FULL_RATE_VER3-1&HALF_RATE_VER1-1&HALF_RATE_VER2-0&HALF_RATE_VER3-1&FULL_RATE_VER5-0;
SET GCELLHOCTRL: IDTYPE=BYID, CELLID=0, BTSMESRPTPREPROC=BTS_Preprocessing, MRPREPROCFREQ=Once_ps;//Deactivating downlink VQI
SET GCELLSOFT: IDTYPE=BYID, CELLID=1, RPTDLVQIALLOWED=DISABLE;
//Deactivating uplink VQI
SET GCELLOTHBASIC: IDTYPE=BYID, CELLID=1, RPTVOICE=NO;

[gogotchiya83]

Tkx for your nice response :)

Can you share with us the first conclusion after enabling this feature?
if you can also share an exemple of the report?

Why you say that you must to wait one week for the result (isn't hourly?)

Regards//
Gogo

[gogotchiya83]

any feedback after the activating of the feature?