High Drop Call Rate

[almoqbali36]

Dear All
I am seeking you help, I have a cell has high drop call rate and i tried to reduce it but i didnt success. i have cange many thinges
- requency plan is very good.
- i have change Radio link Timeout (RLT) from 16 SACCH to 24 SACCH
- i have Change AMR_FR_LINK_FAIL from 28 SACCH to 32 SACCH
- Change AMR_HR_LINK_FAIL from 28 SACCH to 32 SACCH
- change LINK_ABOUT_TO_FAIL from 4 SACCH to 8 SACCH
- change rxlev_access_min from 6 to 5 (-106 to -105 dBm)
- change rach_access_level_threshold from 0 to 10 (-120 to -110 dBm)
- Disable AMR

but still there is high drop rate. even the drive test was very good.
please i am looking for help if possible


Rashid

[babak1349]

Hello
all you have done, is good for poor radio condition. You should find route cause of high drop call
For example it could be due to HW, high interference
If it is possible identify on which TRX high drop call occurs . If you have normal frequency hopping you can disable it and check through drive test to see on which TRX ( carrier ) there is high drop call. You can check received Rxlevel on each TRX and a TRX might have degradation in output power as well
You can check as well Antenna system, you may have problem with UL or VSWR
Regarding RLT you can be aggressive and put it in highest value to see what is the impact

cheers


Dear All
I am seeking you help, I have a cell has high drop call rate and i tried to reduce it but i didnt success. i have cange many thinges
- requency plan is very good.
- i have change Radio link Timeout (RLT) from 16 SACCH to 24 SACCH
- i have Change AMR_FR_LINK_FAIL from 28 SACCH to 32 SACCH
- Change AMR_HR_LINK_FAIL from 28 SACCH to 32 SACCH
- change LINK_ABOUT_TO_FAIL from 4 SACCH to 8 SACCH
- change rxlev_access_min from 6 to 5 (-106 to -105 dBm)
- change rach_access_level_threshold from 0 to 10 (-120 to -110 dBm)
- Disable AMR

but still there is high drop rate. even the drive test was very good.
please i am looking for help if possible


Rashid

[electron]

As a rull of thumb before any changes it is better to see the reason of drop !! As i see most probobly all of ur changes were blind which will make every thing more complicated . In my opinion revert back every thing to default and find drop call reason in STS. Let me give you an example :

If it is due to missed MSC definition (If you have MSC in pool) how your changes will help you ?
If you have missing neighbur and causing drop call how your changes will help?
Does your cell is overshooting?
In general how much is drop call rate ? Maybe it is normal but you feel it is abnormal !
What is clutter type and what is site to site distance? (for example if it is serving rural area and site to site distance is high you can not do much)


I hope these points give you some idea for more investigation . If you share more information we may find the problem somehow.


BR


Dear All
I am seeking you help, I have a cell has high drop call rate and i tried to reduce it but i didnt success. i have cange many thinges
- requency plan is very good.
- i have change Radio link Timeout (RLT) from 16 SACCH to 24 SACCH
- i have Change AMR_FR_LINK_FAIL from 28 SACCH to 32 SACCH
- Change AMR_HR_LINK_FAIL from 28 SACCH to 32 SACCH
- change LINK_ABOUT_TO_FAIL from 4 SACCH to 8 SACCH
- change rxlev_access_min from 6 to 5 (-106 to -105 dBm)
- change rach_access_level_threshold from 0 to 10 (-120 to -110 dBm)
- Disable AMR

but still there is high drop rate. even the drive test was very good.
please i am looking for help if possible


Rashid

[almoqbali36]

Thank you all
Actually the system is ******** BSS and It is connected to Huawei MSS.
The Drop rate is almost 6% and total calls is 600 per hour.
I've checked the HW and it seems ok. The things which I didn't mentioned there is TCH RF LOSS but is not covered rural area and the nearest site is 2.5 KM and the is not overshooting. Unfortunaitlly I couldn't find the KPI which calculate the Drop in each TRX. The handover is good


BR
RASHID

[almoqbali36]

I want to add the drop call rate also is high for two sectors in same site and there is no swap feeder

[yellowant2512]

Hi Bro

Attached tool can help you for TRX (RTF): PB, IOI, BER and Drop call analysis.
Pls add Reputation if it useful for you.

32844

[almoqbali36]

Hi Bro

Attached tool can help you for TRX (RTF): PB, IOI, BER and Drop call analysis.
Pls add Reputation if it useful for you.

32844


Thank you I will try it and update.

[yellowant2512]

The attachment includes guide document about: collect raw data, and using tool to analysing.

[Vladislav]

Thank you all
Actually the system is ******** BSS and It is connected to Huawei MSS.
The Drop rate is almost 6% and total calls is 600 per hour.
I've checked the HW and it seems ok. The things which I didn't mentioned there is TCH RF LOSS but is not covered rural area and the nearest site is 2.5 KM and the is not overshooting. Unfortunaitlly I couldn't find the KPI which calculate the Drop in each TRX. The handover is good


BR
RASHID

Hi Rashid,
I don't know how the things are with ******** BSS but for all other 2G vendors I had worked with it is possible to check the estimated reason of the drops (for e.g. Low DL Level, Low UL Lev, Poor DL Qual, Poor UL Qual, Transition, Hardware fail, etc). So I think your investigation it is better to start from such actions of counters checking, as it was already suggested by mr.Babak. As well it will be useful to trace this cell and check the results if ******** equipment has such ability. You can always check average TA from the MR to be sure that the cell is not an overshooter.
Hope this will help.

[almoqbali36]

The attachment includes guide document about: collect raw data, and using tool to analysing.

Thank you dear I like the tool
what does day Summary do? also Hardware Issues Reports

[almoqbali36]

The attachment includes guide document about: collect raw data, and using tool to analysing.
dear
do you have any other tools like this, it is helpfull for analysis

[yellowant2512]

Which tool do you need? And which vendor?

[almoqbali36]

Which tool do you need? And which vendor?

just good tools for ******** and Huawei