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Hi all
In one cell of Huawei site CSSR is very low (15%-60%)by statistics.
1. DT measurement has been done, but no any problem, CSSR is 100 % in DT.
2. No hardware issue
3. No transmission alarm
4. All rest KPIs are normal
This is formula for CSSR:
[Success Rate of TCH Assignment]*[Success Rate of Call Setup(immediate assignment)]/100
This formula is the same for all Huawei cells and I have never seen any unknown problem like this.
If someone of you has idea please share your experience with me.
Thanks in advance
Please search & read this post.
“Worst CSSR in Huawei”.Br\\
BijoyDear Bijoy
The mentioned post is not existing.
Please read thread 5637.Type “CSSR” in “search for an article”
Yes yes, I found. Thanks.
Can location update failure affect to CSSR even no SD congestion?
Hi
Ideally,LU shouldn’t be considered for calculating CSSR,but the formula you are using considers SDCCH drop during LU.So,yes,your CSSR will get impacted.P.S:There is a way out & you will find that in that very post.
Br\\
BijoyHi Bijoy
I have defined “Channel Request (Packet Call)” is 500-800-1800 times on this cell.
Actually what does it mean, what is Packet Call?
Channel Request for Packet Call means the MS is sending a RACH to access the PS services.
Br\\
BijoyBijoy, please have a look stat for one hour of the mention cell. Its CSSR is very low. I can’t find the cause.
Maybe you can give some ideas to find the reason, PLEASE. Thanks a lot.
Start Time 13/07/2010 06:00:00
Object Name CellA
CA300J:Channel Requests (Circuit Service) 208
CA303J:Call Setup Indications (Circuit Service) 45
Call Setup Success Rate 21.635
CA3030J:Call Setup Indications (SDCCH) (Circuit Service) 45
CA3039J:Call Setup Indications (TCH) (Circuit Service) 0
CA303A:Call Setup Indications (Call Type) 3
CA303B:Call Setup Indications (Non-Call Type) 42
A300A:Channel Requests (MOC) 4
A300C:Channel Requests (MTC) 4
A300D:Channel Requests (Emergency Call) 0
A300E:Channel Requests (Call Re-establishment) 0
A300F:Channel Requests (Location Updating) 200
A300H:Channel Requests (Packet Call) 100
A300I:Channel Requests (LMU+Reserved) 0
A300K:Channel Requests (Protocol Incompatible) 0
CA300A:Channel Requests (Call Type) 8
CA300B:Channel Requests (Non-Call Type) 300
CA303H:Call Setup Indications (Packet Service) 0
K3000:SDCCH Seizure Requests 208
K3003:Successful SDCCH Seizures 208
K3003A:Successful SDCCH Seizures (Call Type) 7
RCA313:Success Rate of TCH Assignment 100
RA303I:Success Rate of Call Setup (Immediate Assignment) 21.635Bijoy, please have a look stat for one hour of the mention cell. Its CSSR is very low. I can’t find the cause.
Maybe you can give some ideas to find the reason, PLEASE. Thanks a lot.
Start Time 13/07/2010 06:00:00
Object Name CellA
CA300J:Channel Requests (Circuit Service) : 208
CA303J:Call Setup Indications (Circuit Service) : 45
Call Setup Success Rate : 21.635
CA3030J:Call Setup Indications (SDCCH) (Circuit Service) : 45
CA3039J:Call Setup Indications (TCH) (Circuit Service) : 0
CA303A:Call Setup Indications (Call Type) : 3
CA303B:Call Setup Indications (Non-Call Type) : 42
A300A:Channel Requests (MOC) : 4
A300C:Channel Requests (MTC) : 4
A300D:Channel Requests (Emergency Call) : 0
A300E:Channel Requests (Call Re-establishment) : 0
A300F:Channel Requests (Location Updating) : 200
A300H:Channel Requests (Packet Call) : 100
A300I:Channel Requests (LMU+Reserved) : 0
A300K:Channel Requests (Protocol Incompatible) : 0
CA300A:Channel Requests (Call Type) : 8
CA300B:Channel Requests (Non-Call Type) : 300
CA303H:Call Setup Indications (Packet Service) : 0
K3000:SDCCH Seizure Requests : 208
K3003:Successful SDCCH Seizures : 208
K3003A:Successful SDCCH Seizures (Call Type) : 7
RCA313:Success Rate of TCH Assignment : 100
RA303I:Success Rate of Call Setup (Immediate Assignment) : 21.635From this data,what I can conclude is:
1.This cell is either at LA boundary or overshooting at LA boundary beacuse LU request is high.
2.Call setup Indication is Low,which means there is either Imm. assignment reject(SDCCH Blk) or call setup indication timed out(T3101 expiry).
3.Your immediate aasignment success is poor for Non-call type.Suggestions
1.Give tilt to the cell if overshooting
2.Check Co-BSIC-BCCH cells,if nearby
3.Increase Cell reselection hysteresis if on LA boundary.
4.Check for SDCCH Blocking(remote possibility)This formula is actually too gross,you should use CSSR for CS services only.
P.S:
You can increase the “RACH Min. Access level”,”RACH Busy threshold”,& “RACH error threshold” to reduce this,but you cant eliminate the effect totally.It is better if you use “Immediate assignment commands/Immediate Assignment requests” in place of RA303I.
Br\\
BijoyYou mean I should use following formula for CSSR?
Immediate assignment commands/Immediate Assignment requests*100
Or what is useful formula for CSSR in Huawei system?
As well
Call Setup Indications Timed Out: 162
for this hour.
No SD blocking
Call Setup Success Rate=BSS Call Establishment Success Rate = [([Success Rate of Call Setup (Immediate Assignment)/{100}) x ([Success Rate of TCH Assignment]/{100}) x (1 – ([Call Drop Rate on SDCCH]/{100})) x {100}.
In this formula,it is recommended to replace [Success Rate of Call Setup (Immediate Assignment)] by “Immediate assignment commands/Immediate Assignment requests”.
Br\\
BijoyHi all,
Instead of “Immediate assignment commands/Immediate Assignment requests” I would recommend using “Channel Requests (Call Type)/Call Setup Indications(Call Type)”.
This excludes Location Update, but considers SDCCH access failures for MOC or MTC (meaning: BSC sends Immediate Assignment but MS does not respond on a given time, which is given by T3101)
BR
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