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taki
2009-06-01, 09:01 PM
Hi all,

I'm facing a big problem, I have a big number of SDCCH drop per cell in my area which decrease CSSR (nokia product).

Please advise

electron
2009-06-01, 09:08 PM
Check the hardware (i mean TRXs)!!!

kais
2009-06-01, 11:34 PM
Check the hardware (i mean TRXs)!!!


change SD to ather TRX !!!

gprastomo
2009-06-02, 12:01 AM
Hi all,

I'm facing a big problem, I have a big number of SDCCH drop per cell in my area which decrease CSSR (nokia product).

Please advise

Hi,

1. Kindly check the alarms whether there is alarms on TRX, Combiner, etc
2. Check Interference, (Co/Adj BCCH or other freq), change the ARFCN to the clean one.
3. Finally, you can move the SDCCH Channel to the other Trx which is clean

br

taki
2009-06-02, 12:10 AM
Thanks friends for your suggestions but I tried all thinks mentionned without
success !!!!

:confused:

gprastomo
2009-06-02, 01:26 AM
Thanks friends for your suggestions but I tried all thinks mentionned without
success !!!!

:confused:


Tell me the specific problem, you give general data

taki
2009-06-02, 01:51 AM
Tell me the specific problem, you give general data

Hi gprastomo,

I'm facing a SDCCH drop problem for about 200 cells !!!!

-I tried to change SD from trx to another one but no success
-The frequency plan is good
-No HW problem

So what's the problem
Please help

armagedd0n
2009-06-02, 02:02 AM
maybe it is N7 link problem,can you see some counter about A (BSC-MSC) interface?

hassen
2009-06-02, 07:38 AM
Hi all,

I'm facing a big problem, I have a big number of SDCCH drop per cell in my area which decrease CSSR (nokia product).

Please advise
hi taki
i suspect transmission link ,and i advice you to ask for investigation A interface with
protocole analyzer,maybe there is hardware problem in bsc level matrix responsible to make connection through transmission link between bsc and bts devices during immediate assignmente.

have a look !
[Only registered and activated users can see links]

br hassen

taki
2009-06-02, 09:51 AM
hi taki
i suspect transmission link ,and i advice you to ask for investigation A interface with
protocole analyzer,maybe there is hardware problem in bsc level matrix responsible to make connection through transmission link between bsc and bts devices during immediate assignmente.

have a look !
[Only registered and activated users can see links]

br hassen

Hi Hassen thanks a lot for your help, take care

kahnoie
2009-06-13, 10:20 PM
Wrong t3212 timer value for few cells is lower than other cells would result in more periodic LU by MS results in high SDCCH load.
SDCCH drops are linked to interference from other cells or due to large cell coverage (many subscribers at the cell border, with low RXLEV). Steps that can be taken to reduce SDCCH blocking are:
1. Increase T3212 from every 4 hours to every 6 or 8 hours.
2. SDCCH HO should be disabled as it does not improve the QoS
3. Try to reduce TA filter from 64 (32km) to 15 (7.5km) for a few hours.
4. Try to increase RXLEV_ACCESS_MIN from -104dBm to -98dBm for a few hours and observe the result.

kais
2009-06-18, 03:17 AM
Hi gprastomo,

I'm facing a SDCCH drop problem for about 200 cells !!!!

-I tried to change SD from trx to another one but no success
-The frequency plan is good
-No HW problem

So what's the problem
Please help


activate HO SD feature and chek for improvement.

Khairul
2009-06-18, 03:21 AM
activate HO SD feature and chek for improvement.

Brother..
Drill into the cause of the SDCCH drop.. is it RF or Non RF reason.. and plans your way from there.. most of the problem could be easily resolved by knowing what cause it.. if it planning, maintenance, traffic driven and only then.. you would resolved and optimized..

Best regards,
krule

adriansyah
2009-09-03, 02:33 AM
try to help:

1. Check Timeslot status (Maybe faulty)
2. Check TRX
3. Check Combiner
4. Check Site status (maybe equip / hw error)
5. Check Transmission link (maybe congestion in a interface)
6. Try to tracing in OMC , and check mobile originating steps , which step it fault (which part , fail like : ran , core and etc)

ghassen
2009-09-03, 03:08 AM
Hi all,

I'm facing a big problem, I have a big number of SDCCH drop per cell in my area which decrease CSSR (nokia product).

Please advise

try to increase the CRH it can work

simmus0300
2009-09-03, 02:01 PM
try to help:

1. Check Timeslot status (Maybe faulty)
2. Check TRX
3. Check Combiner
4. Check Site status (maybe equip / hw error)
5. Check Transmission link (maybe congestion in a interface)
6. Try to tracing in OMC , and check mobile originating steps , which step it fault (which part , fail like : ran , core and etc)

share the commands in nokia with parameters to checking above mentioned
suggestions.

simmus0300
2009-09-03, 02:02 PM
Hi,

1. Kindly check the alarms whether there is alarms on TRX, Combiner, etc
2. Check Interference, (Co/Adj BCCH or other freq), change the ARFCN to the clean one.
3. Finally, you can move the SDCCH Channel to the other Trx which is clean

br

Pl share the commands in nokia with parameters to checking above mentioned
suggestions.

diankestiwi
2009-09-03, 02:51 PM
i think maybe u can change sdcch kanal to the best kanal at that slot

ghassen
2009-09-03, 07:17 PM
Hi all,

I'm facing a big problem, I have a big number of SDCCH drop per cell in my area which decrease CSSR (nokia product).

Please advise
also you can check some counters

simmus0300
2009-09-04, 12:25 AM
also you can check some counters

uote:
Originally Posted by gprastomo View Post
Hi,

1. Kindly check the alarms whether there is alarms on TRX, Combiner, etc
2. Check Interference, (Co/Adj BCCH or other freq), change the ARFCN to the clean one.
3. Finally, you can move the SDCCH Channel to the other Trx which is clean

br
Pl share the commands in nokia with parameters to checking above mentioned
suggestions.

atese
2009-09-28, 03:05 AM
Hi Taki.

Try to check this:
1. timing advance of cell in urban areas, if you have exssesive propagation try to fix it by downtilt, many times the SDCCH drop is originated by some co-channel co-bsic that meet in long distance.
2. Check the rxLevAccesMin and try to set it no more than -102 dB, sometimes we force the mobiles to get the cell in poor RF conditions, around -110. This a SDCCH DC by lost of radiolink during signaling phase.

kais
2009-09-28, 04:15 AM
chek this case :


SD DROP RADIO rate is HIGH then

IF SD DURATION AVG > 6 PER TRX;

--------> A TRX HARDWARE PROBLEM ( RESET AND/OR REPLACE TRX)

nabil el haddani
2009-09-28, 05:09 AM
Probable Reasons of Drops on SDCCH :

Low Signal Strength on Down or Uplink
The reason for poor coverage could be too few sites, wrong output power, shadowing, no indoor coverage or network equipment failure.
Action: Check coverage plots.Check output power. Perform drive tests. Check BTS error log
Solution: Add new sites. Increase output power. Repair faulty equipment.

Poor Quality on Down or Uplink
Action: Check C/I and C/A plots. Check frequency plan. Perform drive tests.
Solution: Change frequency. Use available radio features.

Too High Timing Advance
Action: Check if the cell parameter TALIM is < 63. Check if the co-channel cells are over-heard.
Solution: Set TALIM to a value close to 63. Tilt antenna/reduce antenna height/output power, etc. for co-channel cells.

Mobile Error
Some old mobiles may cause dropped calls if certain radio network features are used. Another reason is that the MS is damaged and not working properly.
Action: .Check MS fleet.
Solution: Inform operator.

Subscriber Behavior
Poorly educated subscribers could use their handsets incorrectly by not raising antennas, choosing ill-advised locations to attempt calls, etc.
Action: Check customer complaints and their MS.

Battery Flaw
When a subscriber runs out of battery during a conversation, the call will be registered as dropped call due to low signal strength or others.
Action: Check if MS power regulation is used. Check if DTX uplink is used.

Congestion on TCH
The SDCCH is dropped when congestion on TCH.
Action: Check TCH congestion
Solution: Increase capacity on TCH or using features like Assignment to another cell, Cell Load Sharing, HCS, Dynamic Half-Rate Allocation and FR-HR Mode Adaptation etc.

capcipcup
2009-12-09, 02:41 PM
i think maybe u can change sdcch kanal to the best kanal at that slot

how do we know which one is the best kanal ?

diankestiwi
2010-01-05, 08:21 PM
how do we know which one is the best kanal ?

as i know we can use batrana for siemens ( and we can calculate from the statistic data ) so we compare each kanal where are better than other.

kadou26
2010-05-28, 01:25 AM
Please every body i want to know what mean this two sentence
"SDCCH lost radio connections (error indication) "
"SDCCH lost radio connections (connection failure)"
in Huawei system (BSC) and I to resolve it.
it's the most important SDCCH drop reason in our network that affect seriously the CSSR

Thanks

capcipcup
2010-06-03, 04:31 PM
as i know we can use batrana for siemens ( and we can calculate from the statistic data ) so we compare each kanal where are better than other.

would you tell me which statistic data should i get
thanks

kadou26
2010-06-03, 07:18 PM
Ok Thank to all

mp9413
2010-06-05, 01:56 PM
Hi,

Abis trace would be useful. Observe the messages flow and identify the abnormal release in SDCCH should give you some hints.

mp

OptimiNSN
2010-06-06, 03:39 AM
Dear I recommend that you sent us the report ND204 of the BSC or BTS, who have problems, so we can help you.