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josef
2010-07-02, 06:39 PM
Dear All,

We have a big problem on AMR 2G. We have just implement it on our network 2G/3G. The problem is that the codecs are not changing when C/I (or AMR quality estimate) change. In some cells it is changing and in others NO. The thresholds are Ok in ALL the cells:

FRT1 = 6dB, FRT2 = 12 dB, FRT3 = 16 dB, HRT1= 11 dB, HRT2 = 14 dB

I checked all the cells, and they have the same AMR parameters.

Find attached our AMR behaviour.

Since now 5 days I'm working on it, but no success

Please some ideas brothers !!!

Josef

RF engineer
2010-07-02, 07:08 PM
Dear All,

We have a big problem on AMR 2G. We have just implement it on our network 2G/3G. The problem is that the codecs are not changing when C/I (or AMR quality estimate) change. In some cells it is changing and in others NO. The thresholds are Ok in ALL the cells:

FRT1 = 6dB, FRT2 = 12 dB, FRT3 = 16 dB, HRT1= 11 dB, HRT2 = 14 dB

I checked all the cells, and they have the same AMR parameters.

Find attached our AMR behaviour.

Since now 5 days I'm working on it, but no success

Please some ideas brothers !!!

Josef
Can you share the logfile.

BR
RF

josef
2010-07-02, 07:48 PM
Can you share the logfile.

BR
RF

Dear bro,

please find the log file: Nemo files

Thank u by advance

Josef

mbo
2010-07-02, 09:02 PM
Hello Bro,
1/Which is the vendor
2/At ALCATEL you have to define the codec of starting used on every HO, you must to have the same thing in the list of your parameter settings. Can you to Check please.
BR

josef
2010-07-02, 11:17 PM
Hello Bro,
1/Which is the vendor
2/At ALCATEL you have to define the codec of starting used on every HO, you must to have the same thing in the list of your parameter settings. Can you to Check please.
BR

The vendor is NSN. Our initial codec (for call setup & HO) is the same: 5.9 Kbps for HR and FR

It is not related to this

Thank u brother

Josef

radio_network
2010-07-02, 11:35 PM
check AMR implemetation at TRX/RTF level.

mbo
2010-07-03, 12:12 AM
I recommend you to modify the codec_init in the high value (12.2 for the FR and 7.95 for the HR) because it impacts directly on your vocal quality.
I am going to verify for thresholds...


The vendor is NSN. Our initial codec (for call setup & HO) is the same: 5.9 Kbps for HR and FR

It is not related to this

Thank u brother

Josef

josef
2010-07-03, 03:18 PM
check AMR implemetation at TRX/RTF level.

Brother,

how to check implementation at TRX/RTF level ?

Thank's

Josef.

RF engineer
2010-07-03, 05:56 PM
Dear bro,

please find the log file: Nemo files

Thank u by advance

Josef

Dear
As i see drive test you have a lot of handover and as AMR initial code or start mode is used for call setup and handover , you initial codec or start mode is 5.9?
BR

josef
2010-07-03, 06:04 PM
Dear
As i see drive test you have a lot of handover and as AMR initial code or start mode is used for call setup and handover , you initial codec or start mode is 5.9?
BR

yes it is

Br

Josef

RF engineer
2010-07-03, 07:01 PM
yes it is

Br

Josef

So in your case you have to do some optimization tasks in order to reduce handover and later make drive test you see some improvement to use higher or lower codecs

josef
2010-07-03, 07:35 PM
So in your case you have to do some optimization tasks in order to reduce handover and later make drive test you see some improvement to use higher or lower codecs

We can't start optimization in our situation.

I explain again, our situation is:

- in 90% of the cells, MS comp on 5.9 codec (on call setup or HO) and it is not changing even if C/I > 25 dB
- in 10% of the cells, MS comp on 5.9 codec and start to upgrade or downgrade basing on radio conditions (C/I level): normal behaviour

NB.

* All cells have same parameters,
* Thresholds for full rate: 6, 9 and 12 dB
* Thresholds for half rate: 11 & 14 dB
* Working cells can be: DCS or GSM 900; Half rate or Full rate

I'm waiting for your help brothers

Josef

RF engineer
2010-07-03, 07:55 PM
We can't start optimization in our situation.

I explain again, our situation is:

- in 90% of the cells, MS comp on 5.9 codec (on call setup or HO) and it is not changing even if C/I > 25 dB
- in 10% of the cells, MS comp on 5.9 codec and start to upgrade or downgrade basing on radio conditions (C/I level): normal behaviour

NB.

* All cells have same parameters,
* Thresholds for full rate: 6, 9 and 12 dB
* Thresholds for half rate: 11 & 14 dB
* Working cells can be: DCS or GSM 900; Half rate or Full rate

I'm waiting for your help brothers

Josef

Yes this 90% is come majority from handover if you don't reduce handover from cells overshooting you will not have any improvement so it is your decision what to do i am not sure any radio parameter can be help to reduce this rate.
BR
RF

josef
2010-07-03, 08:11 PM
Yes this 90% is come majority from handover if you don't reduce handover from cells overshooting you will not have any improvement so it is your decision what to do i am not sure any radio parameter can be help to reduce this rate.
BR
RF

It is not related to handovers. When MS comp on one cell and with all the values that you can imagine of C/I we have THE SAME codec (initial one).

That means that AMR algorithm is not working.

Example: We suppose that we have only full rate. when MS comp on one codec (by starting call or by handover), it will choose the initial code (for us 5.9 Kbps), and it will start to measure C/I. if it measure for example 20 dB, then as our thresholds are FRT1= 6 dB, FRT2= 9 dB, FRT3= 12 dB

ie C/I > FRT1 + Hyst1 (1dB)> FRT2 + Hyst2 (1dB)> FRT1 + Hyst3 (1dB)

MS must upgrade to 7.4 Kbps and then to 12.2 Kbps

If this is not working no need to optimize anything. the problem is not related to parameters

It is related to something that I don't know :)

Any help ?

Regards,
Josef

ayman.absi
2010-07-05, 04:50 AM
Choose one of the cells that the AMR reconfiguration not working and do Drive test stationary (without moving).
Another check AMR license (No. of TRXs that could use AMR) if Total no. of TRXs per BSC > license --> you will have some TRXs not using AMR.

josef
2010-07-05, 06:37 PM
Choose one of the cells that the AMR reconfiguration not working and do Drive test stationary (without moving).
Another check AMR license (No. of TRXs that could use AMR) if Total no. of TRXs per BSC > license --> you will have some TRXs not using AMR.

Dear Ayman,

For one BSC this is the features activated.
FEATURE INFORMATION:
----------------------------------------------
FEATURE CODE:..............73
FEATURE NAME:..............Flexi EDGE BTS Operating SW
FEATURE STATE:.............ON
FEATURE CAPACITY:..........1568
----------------------------------------------
FEATURE CODE:..............74
FEATURE NAME:..............High capa BSC3i new
FEATURE STATE:.............ON
FEATURE CAPACITY:..........2000
----------------------------------------------
FEATURE CODE:..............13
FEATURE NAME:..............PCU2 app SW
FEATURE STATE:.............ON
FEATURE CAPACITY:..........100
----------------------------------------------
FEATURE CODE:..............4
FEATURE NAME:..............EDGE BSS Fnc
FEATURE STATE:.............ON
FEATURE CAPACITY:..........1400
----------------------------------------------
FEATURE CODE:..............1
FEATURE NAME:..............AMR Capacity
FEATURE STATE:.............ON
FEATURE CAPACITY:..........1530

COMMAND EXECUTED

So the feature for AMR is "AMR capacity" or no? the number 1530 is it the number of TRXs where we can have AMR feature?

Thank you by advance,

Josef

ayman.absi
2010-07-05, 07:32 PM
Dear Josef,
Feature Code = 1 is for AMR HR and it is enabled.
What about AMR FR (Feature Code = 72)?
If it is not enabled --> AMR HR will not work in cells with low Traffic.

Thanks,

josef
2010-07-05, 07:39 PM
Dear Josef,
Feature Code = 1 is for AMR HR and it is enabled.
What about AMR FR (Feature Code = 72)?
If it is not enabled --> AMR HR will not work in cells with low Traffic.

Thanks,

I have in some cells a normal behaviour with FR mode (starting with initil codec 5.9 and going to 12.2 Kbps). I think that the feature is enabled. No?

josef
2010-07-07, 01:25 PM
Dear all,

is it possible during implementation that: when we mixe some PCMs between Radio part and Core part, we will have this kind of problem

Thank you by advance.

Josef

josef
2010-07-20, 03:38 AM
Dear community,

We still have the same problem. We discover that the problem is random: for example even in stationary mode sometimes it is working (I mean codec upgrade) and sometimes the initial codec is kept. I check even in timeslot level and the problem is the same: sometimes Ok sometimes NO

We check parameters in radio part and we check also in core part and we couldn't find anything !!

licenses are ok for AMR hr and fr

From where can come this problem?

Your help is really needed

Thank you by advance

Josef

d0000h
2010-07-20, 08:27 AM
Familiar with E*******, not NSN but here it goes. Hopefully you can relate this to NSN and find the problem:

- AMR params on setup different from AMR on call (adaptive) params.
- Params based on BOTH quality and AVAILABLE CAPACITY (on the cell)
- pools of AMR capable vocoders for the BSC. No more vocoders, no more AMR.
- MS must be capable of AMR HR.
- change from FR to HR may only happen when available capacity is below threshold. Otherwise no NEED to change to HR.
- TS consolidation can be enabled. If there are no available FULL TS, then you CANNOT switch from HR to FR.

Q’s:
1) Do you see the codec change requests happening in the logs?
2) Why only 5.9 in FR?
3) What are your settings for FRH1-3 and FRS
4) What are your settings for HRH1-3 and HRS
5) How is it determined if you set up on HR or FR?
(After re-reading your post sound like you most of the issue is only changing codec no changing between HR/FR. So some of the info above maybe not so valid)

josef
2010-07-20, 01:58 PM
Familiar with E*******, not NSN but here it goes. Hopefully you can relate this to NSN and find the problem:

- AMR params on setup different from AMR on call (adaptive) params.
- Params based on BOTH quality and AVAILABLE CAPACITY (on the cell)
- pools of AMR capable vocoders for the BSC. No more vocoders, no more AMR.
- MS must be capable of AMR HR.
- change from FR to HR may only happen when available capacity is below threshold. Otherwise no NEED to change to HR.
- TS consolidation can be enabled. If there are no available FULL TS, then you CANNOT switch from HR to FR.

Q’s:
1) Do you see the codec change requests happening in the logs?
2) Why only 5.9 in FR?
3) What are your settings for FRH1-3 and FRS
4) What are your settings for HRH1-3 and HRS
5) How is it determined if you set up on HR or FR?
(After re-reading your post sound like you most of the issue is only changing codec no changing between HR/FR. So some of the info above maybe not so valid)

1) Do you see the codec change requests happening in the logs?
when it is working yes, but otherwise No
2) Why only 5.9 in FR?
we implement 4.75, 5.9; 7.4 and 12.2 in FR but when it is not working, it stay on 5.9 (the initial codec)
3) What are your settings for FRH1-3 and FRS
FRH1: 6 dB
FRH2: 9 dB
FRH3: 13 dB
FRS: 1dB
4) What are your settings for HRH1-3 and HRS
HRH1: 11 dB
HRH2: 14 dB
HRH2: 0 AS WE HAVE ONLY 3 CODECS 4.75, 5.9 and 7.4
HRS: 1dB
5) How is it determined if you set up on HR or FR?
to go to hr or fr is determinated with 2 param
amrSegLoadDepTchRateLower = 40% and
amrSegLoadDepTchRateUpper = 60 %
So, if load is upper than 60% we go to HR and we wait until load will be lower than 40% to go back to FR
For codecs, we start with initial codec 5.9 (with any rate: HR or FR. We are not forcing the rate mode) then MS start to measure C/I and with comparison with FRHx or HRHx we can have upgrades or downgrades.

In our case, with the same radio conditions (even in stationary mode) we have upgrades only in 20% of calls (even less) !!!

Thank you bro

Josef

josef
2010-07-20, 11:08 PM
Brothers,

is this problem can be related to MGW???

turning OFF/ON AMR feature is helping on something?

Thank's by advance for your replays

Josef

d0000h
2010-07-21, 12:08 AM
3) What are your settings for FRH1-3 and FRS
FRH1: 6 dB
FRH2: 9 dB
FRH3: 13 dB
FRS: 1dB
4) What are your settings for HRH1-3 and HRS
HRH1: 11 dB
HRH2: 14 dB
HRH2: 0 AS WE HAVE ONLY 3 CODECS 4.75, 5.9 and 7.4
HRS: 1dB

Thank you bro, Josef

FRS/HRS are not dB values (just a number 0-3). Is "1" correct for FRS and HRS?

What is FRC and HRC set to and what do you feel your setting means? (it looks like a more complicated parameters). Can you confirm it is set the same setting for ALL of your sites/sectors?

FRT/FRH etc are in units/steps of 0.5dB. Just want to confirm that you are stating the correct dB level and not the parameter settings (i.e FRT1 setting of 12 = 6dB)

-Deuce-

d0000h
2010-07-21, 12:20 AM
3) What are your settings for FRH1-3 and FRS
FRH1: 6 dB
FRH2: 9 dB
FRH3: 13 dB
FRS: 1dB
4) What are your settings for HRH1-3 and HRS
HRH1: 11 dB
HRH2: 14 dB
HRH2: 0 AS WE HAVE ONLY 3 CODECS 4.75, 5.9 and 7.4
HRS: 1dB

Thank you bro, Josef

Sorry, I am a bit unsure. The numbers above are Hysteresis (FRH), and the ones below you gave for Thresholds (FRT). They are (virtually) identical in setting, is this correct or are you FRH and FRT mixed up?

* Thresholds for full rate: 6, 9 and 12 dB
* Thresholds for half rate: 11 & 14 dB

-Deuce-

josef
2010-07-21, 04:32 AM
Sorry, I am a bit unsure. The numbers above are Hysteresis (FRH), and the ones below you gave for Thresholds (FRT). They are (virtually) identical in setting, is this correct or are you FRH and FRT mixed up?

* Thresholds for full rate: 6, 9 and 12 dB
* Thresholds for half rate: 11 & 14 dB

-Deuce-

amrConfigurationFr: hysteresis1 FRH1 1
amrConfigurationFr: hysteresis2 FRH2 1
amrConfigurationFr: hysteresis3 FRH3 1
amrConfigurationFr: threshold1 FRT1 6
amrConfigurationFr: threshold2 FRT2 9
amrConfigurationFr: threshold3 FRT3 12
amrConfigurationHr: hysteresis1 HRH1 1
amrConfigurationHr: hysteresis2 HRH2 1
amrConfigurationHr: hysteresis3 HRH3 1
amrConfigurationHr: threshold1 HRT1 11
amrConfigurationHr: threshold2 HRT2 14
amrConfigurationHr: threshold3 HRT3 0

I made a mistake on writing this email, that's all :)

Any solutions brothers ???

josef
2010-07-22, 09:54 PM
FRS/HRS are not dB values (just a number 0-3). Is "1" correct for FRS and HRS?

What is FRC and HRC set to and what do you feel your setting means? (it looks like a more complicated parameters). Can you confirm it is set the same setting for ALL of your sites/sectors?

FRT/FRH etc are in units/steps of 0.5dB. Just want to confirm that you are stating the correct dB level and not the parameter settings (i.e FRT1 setting of 12 = 6dB)

-Deuce-

In our network:

FRS = 0 and amrConfFrInitCodecMode = 0 (3GPP algorithm) => start with 5.9
HRS = 1 and amrConfHrInitCodecMode = 1 => start with 5.9

FRC = 149 (4.75, 5.9; 7.4 and 12.2)
HRC = 21 (4.75, 5.9 and 7.4)
RRC & HRC are exactly same for all celles

I know that FRT/FRH etc are in units/steps of 0.5dB. please see image attached
waiting for your answer

Br
Josef

josef
2010-08-15, 09:46 AM
The problem was on MGW. One parameter can make your life bad :)

Time Alignment :eek: Disabled ==> Enabled

Thank you brothers

Jo.

moslyi0891
2010-08-15, 10:25 PM
The problem was on MGW. One parameter can make your life bad :)

Time Alignment :eek: Disabled ==> Enabled

Thank you brothers

Jo.


oh ..yes ..thanx for sharing it