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dear all 3G Huawei expert, please help me :)
an indoor cell has low CSSR_CS_voice. RRC rejection due to DL Power COng. this cell has many HSDPA user (reaching almost 50 ) and others are AMR12.2.
is there any strategy to raise CSSR without add new UARFCN or spplitting cell /
thanks before
Dodotiro
Hi,
Rejection due to DL power mainly during the accessibility, and usually it because of Admission Control.
Since you have many HSDPA user, just make sure this :
1. You have Dynamic Power Allocation on your RNC
2. Ensure the Admission Control for the DL Power is correctly set, since i believe this because of the DL Power Spike, so you can increase the AC threshold to higher value, let say 85-90%, dont set it to high since it will generate another problem, eg DCR, system stability.
3. Make sure that you dont have any alarm, VSWR etc which make unnecessary power drift.
4. Just check your CPICH power, and Max power Amplifier, the normal value is CPICH power 33 dBm and Max PA 43 dBm or 35 CPICH power and Max PA 46 dBm. If you set the CPICH power to 36 or 35 dBm but you have only 43 dBm of Max PA so it will generate the AC rejection due to DL Power. Reducing the CPICH power will have some trade off, you will have more capacity on DL power but you ll have less coverage.
5. If you still have this problem so its better to activate 2nd carrier
br
Quote:
Originally Posted by dodotiro
Great explanation, thanks pal.
from all 5 points you stated below. i've check and everything is okay.
no.1 LDR has been tuned
no.2 it is not spike, it happen everyday in busy hour :D
no.3 VSWR is normal (1.1)
no.4 i've set CPICH to 33 and TXpower to 43
no.5 so f2 is better solution yach :D?
Quote:
Originally Posted by gprastomo
Hi,
point 2, need to increase the AC threshold, to 90%
point 4, try to set the Max TX Power to 46 dBm, since you need more power to reduce the DL Power congestion.
if it still problem, then you can add 2nd carrier, you dont need additional HW, just add, if you have the freq license
br
If it purely DL power limitation then you can increase your power amplifier to 40W and keep CPICH to 33 dbm, so it can accommodate more traffic from power point of view.
Btw, in such a situation what is the average hsdpa cell throughput that you are getting ?
yup ,
F2 is the best solution before cell splitting
:D
You can consider trying these if you are able to verify indoor coverage yourself (i.e. you are on site to test the HS speed & voice DCR)
- reduce CPICH to 30dBm OR
- increase Max TX power setting to 50W to 60W if the PA (WRFU) can support 80W.
- Be on site to test 'before' and 'after' effects (dont wait for customer to complain) :).
hi salamanda,
-my CPICH has set to 30 dBm and nothing happen :)
- unfortunatelty my WRFU licence can not support 80 W
btw thanks for the suggestion :D
I believe following Actions need to Execute during Power Congestion Reduction:
1.Reduce the P-CPICH Power Value and Increase the Node B Power.
2.Optimize the Admission Control Threshold to control the AC Rejection due to Lack of DL Power.
2.Add New Carrier/Cell Splitting.
3.Enabled LDR Switch>Many LDR Functions such as Inter-Frequency Handover & Rate Reduction etc.
4.Try to Use Micro Node B with Fiber Connectivity to decrease the feeder losses.
Please Note:- Above all these functions, First of All we need to ensure there should not be Abnormal value of VSWR Alarm.