Solusi untuk Kemacetan Power

Summary

Power congestion will cause low CSSR of both CS and PS service.

We can check counters as below to find power congestion:

VS.RRC.Rej.Power.Cong+VS.RAB.FailEstPs.Power.Cong+VS.RAB.FailEstCs.Power.Cong

In current version, our counter can’t differentiate whether UL or DL power congestion. To check whether UL or DL congestion, we can first check the MeanTCP and MeanRTWP:

1.        Check the Max Tx power of the congested cell

Add cellsetup:cellid=1111, maxtxpower=430

2.        Check counter VS.MeanTCP and VS.MeanTCP.NonHS and calculate the utility ratio to check whether the utility ratio is very high.

3.        Monitor the RTWP to check whether RTWP is very high.

By this check then we can know the uplink and downlink power status.

Currently for uplink we use Equivalent Number of User to do CAC; for downlink we use TCP to do CAC. According to our CAC strategy, first make sure some basic parameters should be configured as follows:

ADD CELLALGOSWITCH: CellId=0, NBMUlCacAlgoSelSwitch=ALGORITHM_SECOND, NBMDlCacAlgoSelSwitch=ALGORITHM_FIRST;

ADD CELLCAC: CellId=0, UlTotalEqUserNum=180;

Solution

If the configuration is correct and power congestion still happen, we recommend solutions as follows:

Uplink power congestion:

l  If RTWP is always very high (more than -90dBm), most probability it was caused by uplink interference. Then first check whether interference problem, if uplink interference problem, then solving interference is the recommended method.

l  If not interference problem. We can:

1.        For single carrier cells or F1 cells, use LDR algorithm:

Switch on the LDR switch:

MOD CELLALGOSWITCH: CellId=0, NBMLdcAlgoSwitch=UL_UU_LDR-1;

Setting LDR action:

MOD CELLLDR: CellId=0, UlLdrFirstAction=BERateRed, UlLdrBERateReductionRabNum=1; GoldUserLoadControlSwitch=ON;

Downlink power congestion:

If TCP ratio is very high, it means downlink power congestion. Then we can:

2.        For single carrier cells, we can use downlink LDR:

l   MOD CELLALGOSWITCH: CellId=0, NBMLdcAlgoSwitch=DL_UU_LDR-1;

l   MOD CELLLDR: CellId=0, DlLdrFirstAction=BERateRed, DlLdrBERateReductionRabNum=1; GoldUserLoadControlSwitch=ON;

3.        For F1 cell, Setting LDR as follows:

l   MOD CELLALGOSWITCH: CellId=0, NBMLdcAlgoSwitch=DL_UU_LDR-1;

l   MOD CELLLDR: CellId=0, DlLdrFirstAction=BERateRed, DlLdrSecondAction=InterFreqLDHO, DlLdrBERateReductionRabNum=1, GoldUserLoadControlSwitch=ON;

Then we can monitor the counters as follows to check the effect of LDR action:

VS.LCC.LDR.InterFreq

VS.LCC.LDR.BERateDL

VS.LCC.LDR.BERateUL

Note: usually power congestion will not happen in dual carrier cell. For single carrier site, if power congestion is serious, expand carrier is recommended.