Solution for Power Congestion

Solution for power congestion 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

To check whether UL or DL congestion, we have many methods: Method1 Check the Downlink power congestion counters as below. VS.RAC.R99.Power.Cong VS.RAC.HSDPA.Power.Cong VS.RAC.Total.Power.Cong

Method2 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.

Method3

Open both uplink and downlink LDR then through the counters as below to check. VS.LCC.LDR.Time.ULPower VS.LCC.LDR.Time.DLPower VS.LCC.LDR.Num.ULPower VS.LCC.LDR.Num.DLPower

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=150;

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

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.

•

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: • •

MOD CELLALGOSWITCH: CellId=0, NBMLdcAlgoSwitch=DL_UU_LDR-1; MOD CELLLDR: CellId=0, DlLdrFirstAction=BERateRed, DlLdrBERateReductionRabNum=1; GoldUserLoadControlSwitch=ON;

3. For F1 cell, Setting LDR as follows:

• •

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

For downlink power congestion, if LDR can’t solve the problem, we can reconfigure the related congestion threshold: 1. Start DL LDR algorithm earlier MOD CELLLDM: DlLdrTrigThd=55, DlLdrRelThd=45;

2. Raise the power congestion threshold MOD CELLCAC: CellId=0, DlConvAMRThd=85, DlConvNonAMRThd=85, DlOtherThd=83, DlHOThd=87, DlCellTotalThd=93;

Note: For single carrier site, if power congestion is serious, expand carrier is recommended.