low SDCCH drop in huawei

[beniy]

Dear Huawei Experts,
Our customer complaint abot low SD rop rate in huawei in comparison with E******* and NSN.

They said Huawei sd drop is fake and we should convince them
If you have any ide please help me about the reason.

[leteo]

Join my club. My network faces the same issue, I can't believe it is so so so good like that.

[beniy]

Join my club. My network faces the same issue, I can't believe it is so so so good like that.
it should be one timer or parameter I think...but what is reason??? Is it good or fake?

[danikd]

You are right!!! there is a problem with SDCCH Drop in Huawei GSM networks. I've seen it for at least 3-4 different networks and there is no explanations provided from Huawei on this issue.
I observe it already from 2006....and up to now there is no solution

[jayk]

I had similar experience with SD Statics in Huawei System. I did not found any timer or parameter, if it had been, Eric and NSN would have followed the same. I believe, formula for SD Drop Rates in Huawei is the reason for same. [ Call Drops on SDCCH]x{100}/[Successful SDCCH Seizures]. I had doubt that [Call Drops on SDCCH] only pegs MOC/MTC voice calls but excludes other reasons of SD Requests like Location Update and SMS. While in Denominator [SDCCH Seizures] considers all kind of seizures. Try calculating with other counters [CELL.SD.CALL.DROPS.CALL]*[100]/ [CELL.SD.SUCC.CALL], this one reflects SD Drops related to calls(MOC/MTC). Pls share your finding, if you conclude something.

[gogotchiya83]

We have an experience of SD Drop in our network,

We increased the value of T200/N200 and the SD drop became very well (0,05%), but it seem that this value is very strange !!!

We doubt also that the formulas used is not correct!!!

Actulay we use : ZCM30:Call Drops on SDCCH per BSC *100/ ZK3003:Successful SDCCH Seizures per BSC
i tried to use this formula as it was suggested by "jayk" : [CELL.SD.CALL.DROPS.CALL]*[100]/ [CELL.SD.SUCC.CALL]
So i found the counter for [CELL.SD.CALL.DROPS.CALL] = CM30C; but i couldn't find the other one : [CELL.SD.SUCC.CALL]
Any help PLZ?
Can you share your experience ? wht is the logic value of the SD Drop of one network still suffer from some coverage problems :(

Regards//

[RF engineer]

Dears

We had this problem when the BSC swapped from 32 to 6000 and 6900 for SDCCH drop and we did analysis found there is time on BSC called DelaySendFailIndtoMSIP.

huawei change this timer from 1second to 6 second and we change back this time to be 1 sec SDCCH drop increase but not been in BSC32.

Attach is the case study

BR

[khurrambilal01]

Hi friends,
There are couple of reasons i have identified,
1) In NSN SDCCH drop formula includes drops on A-interface & ABIS failures (T200), While for Huawei A-interface drops are not included in "SDCCH Drop calls" & ABIS faliures are always zero in Huawei :)
2) Secondly,in Huawei dnominator of SDCCH Drops is SDCCH successful assignments which is pegged at wrong cause point, (For NSN/E*******, it is pegged once establishment indication is recieved from MS, But for Huawei it is pegged once BTS has reserved SDCCH resource and send SDCCH assignment messgae to MS - before MS confirms establishment indication).So denominator is greater for huawei and thus SDCCH drops shows reduced values.

[beniy]

@RF engineer:Thank u so much, but I can not find this parameter DelaySendFailIndtoMSIP !!!!Where is it??Please guide , thank u so much

[beniy]

@Khurrambilal01:
Dear,
you are right but why SD drop is lower even in trace!!!
What you said is about SD drop rate not about number of drop.
Thanks

[RF engineer]

Dear beniy

This parameter is BSC parameter you have to check on BS6C. Which BSC you have 6000 or 6900.

Br

[beniy]

Dear beniy

This parameter is BSC parameter you have to check on BS6C. Which BSC you have 6000 or 6900.

Br
I checked in Help and hedex but nothing found about "DelaySendFailIndtoMSIP"
we have BSC6900.
Is that inner parameter?
Thanks a lot.

[RF engineer]

Dear

Yes in BSC6900 it is not viewable ask your bss team to send you the setting for the timer.

[gogotchiya83]

The attached doc confirm that :)

For me we are using BSC6900, should'I change the setting of this parameter "DelaySendFailIndtoMSIP"?

[gogotchiya83]

Any feedback PLZ :)

[gogotchiya83]

The BSS engineer can't find the parameter "DelaySendFailIndtoMSIP"; any help PLZ?

[beniy]

this is inner parameter

[gogotchiya83]

What's you mean by "inner" parameter?
Where to find the value of this parameter?

[beniy]

What's you mean by "inner" parameter?
Where to find the value of this parameter?
Inner parameters are hidden and you cannot find it there is one post in forum search that in use that one. (Actually I didnot try that)

[gogotchiya83]

thanks for your reply, but it's a BSC parameter :( any help plz?
Can you send me the @ of the thread treating the "inner" parameters?

[malik.ahsan]

The main reason is that in Huawei you can configure all 6 time slots to SDCCH on Main BCCH TRX unlike NSN and e*******. Configuring SD timeslots on BCCH TRX improves the SD drop rate especially in remote cells.

[hassan.attique]

AOA people i have already done detail working on Huawei SDR and NSN SDR. My observations are as below.

1. There is 1 parameter that people on this thread have already mentioned. That parameter stop the counter pegging. If that parameter is set as genuine then normally on a mature network huawei SDR is around .5 and .6.

2. Now the other problem is why NSN SD Drop is very high. The problem is with the shit nokia product team. They are also pegging drop in release phase. Like you have send an SMS after sending system need to clear the resources but if that procedure is not completed and T200(N+1) timer expire NSN consider it as a drop call. This problem is in both counters SDCCH RADIO FAIL and SDCCH ABIS FAIL. Where as these drops huawei and E******* dont consider as a drop call. This is why NSN SD Drop Rate is always higher as compared to any other vender. If someone has confusion he can email me on hassan.attique@gmail.com. I have detail about everything. Even NSN care team is agreed on my point they are pegging Sd Drop that are even not user impacting.

Br,s
Hassan Atique

[beniy]

AOA people i have already done detail working on Huawei SDR and NSN SDR. My observations are as below.1. There is 1 parameter that people on this thread have already mentioned. That parameter stop the counter pegging. If that parameter is set as genuine then normally on a mature network huawei SDR is around .5 and .6.2. Now the other problem is why NSN SD Drop is very high. The problem is with the shit nokia product team. They are also pegging drop in release phase. Like you have send an SMS after sending system need to clear the resources but if that procedure is not completed and T200(N+1) timer expire NSN consider it as a drop call. This problem is in both counters SDCCH RADIO FAIL and SDCCH ABIS FAIL. Where as these drops huawei and E******* dont consider as a drop call. This is why NSN SD Drop Rate is always higher as compared to any other vender. If someone has confusion he can email me on hassan.attique@gmail.com. I have detail about everything. Even NSN care team is agreed on my point they are pegging Sd Drop that are even not user impacting.Br,sHassan AtiqueDear Hassan,For Huawei is not related to that parameter I tested even for aggresive value no visible change.In E// we have same counter and we tested same result.For NSN u r right but that's just one reason

[Handover24]

Dear Hassan,For Huawei is not related to that parameter I tested even for aggresive value no visible change.In E// we have same counter and we tested same result.For NSN u r right but that's just one reason
Please could you provide us some usefull documentation ?
I'm very interested about this argument.
Thanks in advance.

[airian]

hi All,

I have found the hidden BSC parameter DelaySendFailIndtoMSIP in Huawei BSC 6900 R13. its name is changed now.
its available in the BSC OTHSOFTPARA and name is BSCRESERVEDPARA17. following is a brief description of its functionality. kindly add REP and Thanks.



MO
Parameter ID
MML Command
BIT
Meaning
Default Value
Impact on Radio Network Performance


OTHSOFTPARA
BSCRESERVEDPARA17
SET OTHSOFTPARA
Bit15
Whether the BSC sends a Clear Request message to the MSC with a 6s delay after receiving a Connect Failure, Error Indication, or Release Indication message from the BTS.
0: The BSC sends a Clear Request message to the MSC with a 6s delay after receiving a Connect Failure, Error Indication, or Release Indication message from the BTS.
1: The BSC sends a Clear Request message to the MSC immediately after receiving a Connect Failure, Error Indication, or Release Indication message from the BTS.
0
If this parameter is set to 1, the values of the counters Call Drop Rate on SDCCH, Call Drop Rate on TCH per cell(including Handover), and Call Drop Rate on TCH per cell(Excluding Handover) increase.

[BENRHOUMASALEM]

hi,
please to check if the location update is included in Drop SDCCH huawei formula !
in our case, huawei R&D confirme that it included but after trace check, we dont find it
BR

[fahmi]

Dear All,

In fact we face the same problem and below the explanation

CM30 not counted for “ciphering mode reject: cause radio interface failure”, in the BSC counter mechanism, only count “Clear Request” sent by BSC and the major problem is that the BSCHU is configured to send clear request after 6s from receiving “Error indication” or ”Connection failure”. But we found that before BSC sending “Clear request”, the MSC already sent “Clear Command”, so the BSC will not send Clear Request anymore, so this case will not be counted as SD drop.
This 6s timer will be stopped by message(such as MSC clear command) or be expired after 6s. When the timer is expire, BSC will report clear request to MSC and call drop will be counted in BSC.

A switch determines whether to start the Timer. This timer does not take effect if the most significant bit of Reserved parameter 17 is set to 1 (that is, Reserved parameter 17 is set to 32768 : SET OTHSOFTPARA command to set Reserved parameter 17 as required.

BR,