UMTS PS RAB Congestion - Huawei

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2012-09-05, 07:34 PM
khurrambilal01

UMTS PS RAB Congestion - Huawei
Hi Friends,

I have Huawei 3G network, there is high PS RAB congestion and from Huawei PS congestion counters i have checked below things:
- lub congestion (VS.RAB.FailEstabPS.lubband.Cong)
- CE congestion (VS.RAB.FailEstabPS.CE.Cong)
- Code Congestion (VS.RAB.FailEstabPS.Code.Cong)
- Power congestion (VS.RAB.FailEstabPS.Power.Cong)
Out of the total PS RAB congestion 60% is Power congestion but rest 40% is not from any of the above reasons.
Can you share what can be the other causes, Like HSPA Congestion or some thing else?
2012-09-06, 12:05 PM
khurrambilal01

Re: UMTS PS RAB Congestion - Huawei

Hi friends,
Anyone plz comment? Thanks!
2012-09-07, 03:29 AM
khurrambilal01

Re: UMTS PS RAB Congestion - Huawei

Nobody can answer :(
2012-09-07, 12:00 PM
Fado

Re: UMTS PS RAB Congestion - Huawei

hi check below counters too,
- VS.RAB.FailEstPs.Code.Cong: PS RAB establishment failures due to code congestion
- VS.RAB.FailEstPs.Power.Cong: PS RAB establishment failures due to power congestion
- VS.RAB.FailEstPs.ULCE.Cong: PS RAB establishment failures due to UL CE congestion
- VS.RAB.FailEstPs.DLCE.Cong: PS RAB establishment failures due to DL CE congestion
- VS.RAB.FailEstab.PS.DLIUBBand.Cong: PS RAB establishment failures due to UL Iub bandwidth congestion
- VS.RAB.FailEstab.PS.ULIUBBand.Cong: PS RAB establishment failures due to DL Iub bandwidth congestion
- VS.RAB.FailEstabPS.Unsp.Other: PS RAB establishment failures due to congestion in other resources than the previous 6 cases
- VS.RAB.FailEstabPS.RNL.Other: PS RAB establishment failures due to any RNL related reason other than the previous 10 cases

• Lack of system resources like memory, high CPU load, etc.
- VS.RAB.FailEstPS.NResAvail: PS RAB establishment failures due to shortage on system resources

• Any other reason: following counter indicate failure due to any other reason apart from the previous ones
- VS.RAB.FailEstabPS.Other.Cell: PS RAB establishment failures due to any other reason except the previous 13 cases
2012-09-07, 06:13 PM
miri

Re: UMTS PS RAB Congestion - Huawei

Hi,

try to see how many times and how long the cell is in Overload state:
VS.LCC.OLC.UL.Num - Number of UL Overload Congestions for Cell
VS.LCC.OLC.DL.Num - Number of DL Overload Congestions for Cell
VS.LCC.OLC.UL.Time - Duration of UL Overload Congestion for Cell
VS.LCC.OLC.DL.Time - Duration of DL Overload Congestion for Cell

Btw, which software release do you use? The counter names change from release to release.
2012-09-07, 07:57 PM
khurrambilal01

Re: UMTS PS RAB Congestion - Huawei

We are using RAN 12.0

Quote:

Originally Posted by miri

Hi,

try to see how many times and how long the cell is in Overload state:
VS.LCC.OLC.UL.Num - Number of UL Overload Congestions for Cell
VS.LCC.OLC.DL.Num - Number of DL Overload Congestions for Cell
VS.LCC.OLC.UL.Time - Duration of UL Overload Congestion for Cell
VS.LCC.OLC.DL.Time - Duration of DL Overload Congestion for Cell

Btw, which software release do you use? The counter names change from release to release.
2012-09-28, 04:05 PM
mobile4lte

Re: UMTS PS RAB Congestion - Huawei

ye,i understand now ,why my 3G network speed could be so slow.
2012-10-05, 02:02 AM
phuvuong_uk

Re: UMTS PS RAB Congestion - Huawei
Quote:
Originally Posted by khurrambilal01

Hi Friends,

I have Huawei 3G network, there is high PS RAB congestion and from Huawei PS congestion counters i have checked below things:

lub congestion (VS.RAB.FailEstabPS.lubband.Cong)
CE congestion (VS.RAB.FailEstabPS.CE.Cong)
Code Congestion (VS.RAB.FailEstabPS.Code.Cong)
Power congestion (VS.RAB.FailEstabPS.Power.Cong)
Out of the total PS RAB congestion 60% is Power congestion but rest 40% is not from any of the above reasons.
Can you share what can be the other causes, Like HSPA Congestion or some thing else?
Do you use 2 carriers for 1 cell? If yes, check the Service Priority for RNC and cell.
2012-10-05, 12:09 PM
maoper11

Re: UMTS PS RAB Congestion - Huawei

check the RTWP, and if you have 2 carriers configure some feature for load balancing.
2012-10-11, 06:44 PM
sant

Re: UMTS PS RAB Congestion - Huawei

make sure the coverage is good...
I think the best way to overcome the congestion is by downtilt...

Regard,
2013-07-22, 01:18 AM
khurrambilal01

Re: UMTS PS RAB Congestion - Huawei

Quote:

Originally Posted by phuvuong_uk

Do you use 2 carriers for 1 cell? If yes, check the Service Priority for RNC and cell.

Hi,
We have two carriers for one cell, How to check Service priority for RNC & cell?
2013-07-22, 03:54 PM
tharinduwije

Re: UMTS PS RAB Congestion - Huawei

Go to RNC MML & in help tab type SPG (Service Priority Group).You can use DRD based load balancing with either serviced based or Load based Switch.We currently have two carriers configured with Service Priority.Best way to reduce Power congestion is Reduce Tilt or Deploy more carries.Take a TCP export (Total Cell Power) & see for which services most of the power has been used (AMR or HSDPA).Then you can adjust them accordingly.Power congestion Significantly impacts user throughput.

Re: UMTS PS RAB Congestion - Huawei

Hi everyone,

If you want to reduce pw congestion should verify the dedicate channel on RNC in fact, how many power does it have the DPCCH (dB). I changed to 4dB and it was succesfull. the pw congestion decreased. Be carefull and dont forget add reputation :)

SET UFRC: PilotPo=4;

PilotPo Pilot power offset Meaning: Transmit power offset of pilot bits to data bits in every timeslot for a downlink DPCCH frame. For details about this parameter, see 3GPP TS 25.214.
This parameter is an advanced parameter. To modify this parameter, contact Huawei Customer Service Center for technical support.

GUI Value Range: 0~24

Unit: 0.25dB

Actual Value Range: 0~6

MML Default Value: None

Recommended Value: 12

Parameter Relationship: None

Service Interrupted After Modification: No (And no impact on the UE in idle mode)

Impact on Network Performance: The smaller the value of this parameter: the lower the transmit power of pilot bits, the less accurate of the SIR assessment on the UE side, the greater the downlink DPCCH transmit power fluctuation, and the higher the downlink DPDCH mean power. The small parameter value also affects downlink cell capacity. The larger the value of this parameter, the higher the transmit power of pilot bits. The large parameter value also wastes downlink power resources and affects downlink cell capacity.

DlDpchSf256PilotBit DL DPCH pilot bits of SF256 Meaning: This parameter specifies the number of DPCCH pilot bits in each timeslot used when the spreading factor for DL DPCH is 256, so as to determine the timeslot format.
- The value D2 of this parameter corresponds to timeslot format 2 or 3.
- The value D4 of this parameter corresponds to timeslot format 4 or 5.
- The value D8 of this parameter corresponds to timeslot format 6 or 7.
For details of this parameter, refer to the 3GPP TS 25.211.

GUI Value Range: D2, D4, D8

Unit: bit

Actual Value Range: 2, 4, 8

MML Default Value: None

Recommended Value: D4

Parameter Relationship: None

Service Interrupted After Modification: No (And no impact on the UE in idle mode)

Impact on Network Performance: When this parameter is set to D8, the number of downlink DPCCH pilot bits increases. In this case, UEs can obtain more accurate SIRs but the transmit power of DPCCH pilots is high. To reduce the transmit power of these pilots, you can use a small pilot power offset for these pilots. By doing this, the downlink cell capacity increases. When this parameter is set to D2, the number of downlink DPCCH pilot bits decreases. In this case, UEs obtain less accurate SIRs and the transmit power of DPCCH pilots is low. To increase the transmit power of these pilots, you can use a large pilot power offset for these pilots. By doing this, the downlink cell capacity decreases.

2013-10-05, 12:09 AM
shishio

Re: UMTS PS RAB Congestion - Huawei

Hi,

also check if you have any SCTP link congestion alarms on the sites, if yes then you have to tell transmission guys to expand the link.
2013-10-05, 12:18 AM
shishio

Re: UMTS PS RAB Congestion - Huawei

Quote:

Originally Posted by tharinduwije

Go to RNC MML & in help tab type SPG (Service Priority Group).You can use DRD based load balancing with either serviced based or Load based Switch.We currently have two carriers configured with Service Priority.Best way to reduce Power congestion is Reduce Tilt or Deploy more carries.Take a TCP export (Total Cell Power) & see for which services most of the power has been used (AMR or HSDPA).Then you can adjust them accordingly.Power congestion Significantly impacts user throughput.

hello tharinduwije,

how do i check which service uses the power? which counter will show this?

PilotPo	Pilot power offset	Meaning: Transmit power offset of pilot bits to data bits in every timeslot for a downlink DPCCH frame. For details about this parameter, see 3GPP TS 25.214. This parameter is an advanced parameter. To modify this parameter, contact Huawei Customer Service Center for technical support. GUI Value Range: 0~24 Unit: 0.25dB Actual Value Range: 0~6 MML Default Value: None Recommended Value: 12 Parameter Relationship: None Service Interrupted After Modification: No (And no impact on the UE in idle mode) Impact on Network Performance: The smaller the value of this parameter: the lower the transmit power of pilot bits, the less accurate of the SIR assessment on the UE side, the greater the downlink DPCCH transmit power fluctuation, and the higher the downlink DPDCH mean power. The small parameter value also affects downlink cell capacity. The larger the value of this parameter, the higher the transmit power of pilot bits. The large parameter value also wastes downlink power resources and affects downlink cell capacity.
DlDpchSf256PilotBit	DL DPCH pilot bits of SF256	Meaning: This parameter specifies the number of DPCCH pilot bits in each timeslot used when the spreading factor for DL DPCH is 256, so as to determine the timeslot format. - The value D2 of this parameter corresponds to timeslot format 2 or 3. - The value D4 of this parameter corresponds to timeslot format 4 or 5. - The value D8 of this parameter corresponds to timeslot format 6 or 7. For details of this parameter, refer to the 3GPP TS 25.211. GUI Value Range: D2, D4, D8 Unit: bit Actual Value Range: 2, 4, 8 MML Default Value: None Recommended Value: D4 Parameter Relationship: None Service Interrupted After Modification: No (And no impact on the UE in idle mode) Impact on Network Performance: When this parameter is set to D8, the number of downlink DPCCH pilot bits increases. In this case, UEs can obtain more accurate SIRs but the transmit power of DPCCH pilots is high. To reduce the transmit power of these pilots, you can use a small pilot power offset for these pilots. By doing this, the downlink cell capacity increases. When this parameter is set to D2, the number of downlink DPCCH pilot bits decreases. In this case, UEs obtain less accurate SIRs and the transmit power of DPCCH pilots is low. To increase the transmit power of these pilots, you can use a large pilot power offset for these pilots. By doing this, the downlink cell capacity decreases.