諾基亞異頻負(fù)載均衡報告-20160315 - AMLE

1、 諾基亞異頻負(fù)載均衡報告諾基亞異頻負(fù)載均衡報告 諾基亞北京項目LTE優(yōu)化組2016年3月目錄1.背景22.負(fù)載均衡功能測試32.1異廠家負(fù)載均衡功能測試32.1.1參數(shù)設(shè)置42.1.2實驗效果62.2同廠家同站雙載波負(fù)載均衡功能測試82.1.3參數(shù)設(shè)置92.1.4實驗效果103.遺留問題111. 背景在LTE中，由于小區(qū)半徑的減少，用戶分布不均勻的現(xiàn)象十分嚴(yán)重，經(jīng)常會出現(xiàn)某個小區(qū)負(fù)載較重而其鄰居負(fù)載較低的現(xiàn)象，不僅會降低網(wǎng)絡(luò)容量而且還會影響到用戶的服務(wù)質(zhì)量。上述原因直接促使了負(fù)載均衡技術(shù)的誕生，在保證用戶的服務(wù)質(zhì)量的同時，使網(wǎng)絡(luò)總?cè)萘窟_(dá)到最大化。目前所支持的負(fù)載均衡功能如下：Ø iF

2、LB：Inter Frequency Load Balance 異頻負(fù)載平衡當(dāng)高負(fù)荷小區(qū)的負(fù)荷超過High Load門限后進(jìn)入iFLB激活狀態(tài)，并可以觸發(fā)LB切換，直到小區(qū)負(fù)荷低于Target load門限，則退出iFLB激活狀態(tài)；在iFLB激活狀態(tài)期間，ENB間的負(fù)荷信息不通過X2接口進(jìn)行交互，所以這種狀態(tài)下觸發(fā)的LB切換屬于鄰區(qū)負(fù)荷未知的盲切換，只要目標(biāo)鄰區(qū)的下行rsrp大于設(shè)定的LNHOIF:thresholdRsrpIFLBFilter參數(shù)門限就會觸發(fā)。而當(dāng)切換請求消息(Handover Request Cause: Reduce Load in Serving Cell)發(fā)送給異頻的

3、目標(biāo)鄰區(qū)時如果鄰區(qū)負(fù)荷已經(jīng)超過了自己小區(qū)設(shè)置的Target Load門限的話，鄰區(qū)會拒絕該切換請求。Ø AMLE：Active Mode Load Equalization主動模式負(fù)載均衡小區(qū)開通AMLE功能后，當(dāng)小區(qū)的負(fù)荷門限高于High Load的時候，小區(qū)會觸發(fā)和異頻鄰區(qū)的負(fù)荷信息交換，它通過X2連接獲取鄰區(qū)的CAC信息(即鄰區(qū)的綜合可用容量)，當(dāng)主小區(qū)和異頻鄰區(qū)負(fù)荷滿足如下條件時觸發(fā)AMLE的LB切換： 當(dāng)鄰區(qū)可用容量與本小區(qū)的可用容量差值大于設(shè)定參數(shù)門限AMLEPR:deltaCac時則觸發(fā)LB的切換 主小區(qū)的可用容量<AMLEPR:maxCacThreshold 鄰

4、區(qū)的可用容量>= AMLEPR:cacHeadroom UE檢測到的目標(biāo)鄰區(qū)的下行rsrp大于設(shè)定的LNHOIF:thresholdRsrpIFLBFilter參數(shù)門限iFLB與AMLE的區(qū)別：iFLBAMLE當(dāng)小區(qū)達(dá)到高負(fù)載門限時，iFLB 提供負(fù)載均衡AMLE將小區(qū)與配對鄰區(qū)的負(fù)載差異控制在所設(shè)的負(fù)載差值以內(nèi)iFLB的目的是把小區(qū)的負(fù)載控制在所設(shè)的負(fù)載門限下，而不是平衡小區(qū)間的負(fù)載候選鄰區(qū)的篩選過程類似iFLB負(fù)載的信息只在同個eNB的小區(qū)間分享；對于不同eNB小區(qū)使用的是盲切換，不根據(jù)鄰區(qū)的負(fù)載情況來判斷小區(qū)間使用資源狀態(tài)報告(RSR)來分享負(fù)載情況，不使用盲切換，對于沒有RSR的

5、鄰區(qū)將不會被切換2. 負(fù)載均衡功能測試2.1 異廠家負(fù)載均衡功能測試為進(jìn)行Nokia和 HW LTE 基站間負(fù)載均衡的實驗，選定實驗點為首都機(jī)場T1出發(fā)廳。如下圖所示，涉及到的Nokia小區(qū)為朝陽機(jī)場T1F2至F3層公共區(qū)NLM（ENB ID：76309），涉及到的HW基站為順義首都機(jī)場T1航站樓F2F3東側(cè)辦公餐飲區(qū)及出港大廳HLM 499769-132。2.1.1 參數(shù)設(shè)置Ø 開啟feature LTE1531: Inter-frequency Load Balancing Extension（開啟iFLB）Parameter NameParameter Full NameMOC

6、默認(rèn)值修改值03019:0613：00修改值0226-210:4511:30修改值0226-110:0010:30actInterFreqLBActivation of inter frequency load balancing (iFLB)LNBTSfalseTRUETRUETRUEthresholdRsrpIFLBFilterInter-Frequency  LB Threshold for RSRP Target FilterLNHOIF-98-95-95-95thresholdRsrqIFLBFilterInter-Frequency  LB Threshold

7、for RSRQ Target FilterLNHOIF-12-12-12-12targetLoadGbrDlDL GBR resource target loadLNCEL50505050targetLoadNonGbrDlDL non-GBR resource target loadLNCEL75755%8%targetLoadPdcchPDCCH target loadLNCEL503%50%5%iFLBHighLoadGBRDLInter-Frequency Load Balancing DL GBR High LoadLNCEL60606060iFLBHighLoadNonGBRDL

8、Inter-Frequency Load Balancing DL non-GBR High LoadLNCEL85858%10%iFLBHighLoadPdcchInter-Freq Load Balancing PDCCH High LoadLNCEL805%80%7%nomNumPrbNonGbrNominal number of PRBs for load balancingLNCEL1101010iFLBBearCheckTimerInter-Frequency Load Balancing QCI1 Bearer Check TimerLNCEL12121212prohibitLB

9、HOTimerProhibit Load Based Handover TimerLNCEL10101010iFLBRetryTimerInter Freq Load Bal Retry TimerLNCEL60606060Ø 開啟feature LTE1841: Inter-Frequency Load Equalization（開啟AMLE）MO ClassParameter NameParameter Full Name默認(rèn)值修改值3月1日16:39:00LNBTSactIfHoEnable interFrequency handoverenabledenabledLNBTSa

10、ctAmleActivate active mode load equalizationfalseTRUELNBTSactInterFreqLBActivation of inter frequency load balancing (iFLB)falseTRUELNBTSprohibitLBHOTimerProhibit Load based handover timer1010LNRELamleAllowedActive mode load equalization allowedfalseTRUELNRELremoveAllowedRemove allowedtrueFALSELNHOI

11、FthresholdRsrpIFLBFilterInter-freq load bal threshold for RSRP target filter-98-95LNHOIFthresholdRsrqIFLBFilterInter-freq load bal threshold for RSRQ target filter-12不設(shè)置LNCELcellResourceSharingModeCell resource sharing modenonenoneLNCELthreshold2InterFreqThreshold th2 interFreq for RSRP-100-90LNCELt

12、hreshold2aThreshold th2a for RSRP-96-87LNCELiFLBRetryTimerInter Freq Load Bal Retry Timer6060sLNCELiFLBHighLoadGBRDLInter-frequency load balancing GBR high load DL6060%LNCELiFLBHighLoadNonGBRDLInter-frequency load balancing non-GBR high load DL858%LNCELiFLBHighLoadPdcchInter-frequency load balancing

13、 PDCCH high load8080%LNCELiFLBBearCheckTimerInter-frequency load balancing QCI1 Bearer check timer1212sLNCELcellCapClassCell capacity class value100100LNCELtargetLoadGbrDlDL GBR resource target load5050%LNCELtargetLoadNonGbrDlDL non-GBR resource target load755%LNCELtargetLoadPdcchPDCCH target load50

14、50%LNCELmlbEicicOperModeMode for calculating the CAC in load bal. and eICICallUesallUesLNCELnomNumPrbNonGbrNominal number of PRBs for load balancing110LNCELulStaticCacStatic CAC for uplink100100LNCELulCacSelectionUplink CAC source selectionulReflectDlCaculReflectDlCacLNCEL-AMLEPRamlePrIdamlePrId0/10

15、LNCEL-AMLEPRdeltaCacDifference in CAC of source and target cells205%LNCEL-AMLEPRcacHeadroomHeadroom in CAC00LNCEL-AMLEPRtargetCarrierFreqTarget carrier frequency39148LNCEL-AMLEPRmaxCacThresholdThreshold for maximum CAC1001002.1.2 實驗效果Ø 開啟feature LTE1531: Inter-frequency Load Balancing Extension

16、（開啟iFLB）開啟feature LTE1531后，指標(biāo)統(tǒng)計Nokia76309-1和HW 499769-132基于iFLB的LB HO全部成功，信令顯示觸發(fā)原因為reduce-load-in-serving-cell，符合預(yù)期。SDATETIMEENB_CELLHO_LB_ATTHO_LB_SUCCHIGH_CELL_LOAD_LB20160226100076309-1111820160226101576309-1442520160226103076309-1773220160226104576309-128289120160226110076309-1331620160226111576

17、309-1111120160226113076309-13325201603010945 76309_13328201603011000 76309_14343215201603011015 76309_18862201603011030 76309_1004201603011045 76309_11114201603011100 76309_18722201603011115 76309_15144146201603011130 76309_1201680201603011145 76309_1161571201603011200 76309_12110201603011215 76309_

18、15240170201603011230 76309_17733201603011245 76309_1201762201603011300 76309_12113Ø 開啟feature LTE1841: Inter-Frequency Load Equalization（開啟AMLE）開啟feature LTE1841后，指標(biāo)統(tǒng)計LB HO有嘗試計數(shù)，信令顯示觸發(fā)原因也為reduce-load-in-serving-cell，但同時也開啟了iFLB，為了區(qū)分LB基于具體feature，抓取wireshark，Nokia小區(qū)有發(fā)起資源請求，但未出現(xiàn)廠家間資源信息交互。SDATETIM

19、EENB_CELLHO_LB_ATTHO_LB_SUCCHIGH_CELL_LOAD_LB20160301160076309_100020160301161576309_100020160301163076309_1473615620160301164576309_1554622920160301170076309_100020160301171576309_100076309向HW小區(qū)發(fā)起的資源請求消息類型為Composite Available Capacity Periodic，周期性綜合可用容量。IE/Group NamePresenceRangeIE type and referen

20、ceSemantics descriptionCriticalityAssigned CriticalityReport CharacteristicsOBITSTRINGEach position in the bitmap indicates measurement object the eNB2 is requested to report.YESreject(SIZE(32)First Bit = PRB Periodic,Second Bit=  TNL load Ind Periodic,Third Bit = HW Load Ind Periodic,Four

21、th Bit = Composite Available Capacity Periodic.Bits 5 to 32 shall be ignored by the eNB22.2 同廠家同站雙載波負(fù)載均衡功能測試為進(jìn)行Nokia同站內(nèi)各載波間負(fù)載均衡的實驗，選定實驗點為76413朝陽機(jī)場2號航站樓出發(fā)廳南側(cè)NLM，該站點兩個載波業(yè)務(wù)量和用戶數(shù)分布不均。2.1.3 參數(shù)設(shè)置開啟feature LTE1841: Inter-Frequency Load Equalization（開啟AMLE）MO ClassParameter NameParameter Full Name默認(rèn)值修改值3.2

22、10：00LNBTSactIfHoEnable interFrequency handoverenabledenabledLNBTSactAmleActivate active mode load equalizationFALSETRUELNBTSactInterFreqLBActivation of inter frequency load balancing (iFLB)FALSEFALSELNBTSprohibitLBHOTimerProhibit Load based handover timer1010LNRELamleAllowedActive mode load equaliz

23、ation allowedFALSETRUELNRELremoveAllowedRemove allowedTRUEFALSELNHOIFthresholdRsrpIFLBFilterInter-freq load bal threshold for RSRP target filter-98-90LNHOIFthresholdRsrqIFLBFilterInter-freq load bal threshold for RSRQ target filter-12不設(shè)置LNCELcellResourceSharingModeCell resource sharing modenonenoneL

24、NCELthreshold2InterFreqThreshold th2 interFreq for RSRP-100-90LNCELthreshold2aThreshold th2a for RSRP-96-87LNCELiFLBRetryTimerInter Freq Load Bal Retry Timer6060sLNCELiFLBHighLoadGBRDLInter-frequency load balancing GBR high load DL6060%LNCELiFLBHighLoadNonGBRDLInter-frequency load balancing non-GBR

25、high load DL858%LNCELiFLBHighLoadPdcchInter-frequency load balancing PDCCH high load8080%LNCELiFLBBearCheckTimerInter-frequency load balancing QCI1 Bearer check timer1212sLNCELcellCapClassCell capacity class value100100LNCELtargetLoadGbrDlDL GBR resource target load5050%LNCELtargetLoadNonGbrDlDL non

26、-GBR resource target load755%LNCELtargetLoadPdcchPDCCH target load5050%LNCELmlbEicicOperModeMode for calculating the CAC in load bal. and eICICallUesallUesLNCELnomNumPrbNonGbrNominal number of PRBs for load balancing110LNCELulStaticCacStatic CAC for uplink100100LNCELulCacSelectionUplink CAC source s

27、electionulReflectDlCaculReflectDlCacLNCEL-AMLEPRamlePrIdamlePrId0/10LNCEL-AMLEPRdeltaCacDifference in CAC of source and target cells205%LNCEL-AMLEPRcacHeadroomHeadroom in CAC00LNCEL-AMLEPRtargetCarrierFreqTarget carrier frequency39148LNCEL-AMLEPRmaxCacThresholdThreshold for maximum CAC1001002.1.4 實驗

28、效果修改后76413兩載波用戶數(shù)實現(xiàn)均衡，1小區(qū)用戶數(shù)下降，PRB利用率下降，同時11小區(qū)用戶數(shù)增加，PRB利用率有所上升。由于是站內(nèi)切換無明顯log顯示LB HO，但切換事件均為LB切換的所用事件A4，符合預(yù)期。SDATETIMEENB_CELLHO_LB_ATTHO_LB_SUCCHIGH_CELL_LOAD_LB201603020800 76413_1000201603020815 76413_1000201603020830 76413_1000201603020845 76413_1000201603020900 76413_1000201603020915 76413_100020

29、1603020930 76413_1000201603020945 76413_1000201603021000 76413_11381370201603021015 76413_11201180201603021030 76413_11721690201603021045 76413_12372370201603021100 76413_12432400201603021115 76413_12642620201603021130 76413_12102050201603021145 76413_12072030201603021200 76413_11461420201603021215

30、76413_11401390201603021230 76413_11561540201603021245 76413_12302280201603021300 76413_11971960201603021315 76413_12192110201603021330 76413_12162150201603021345 76413_12222180201603021400 76413_11681650201603021415 76413_11711680201603021430 76413_11251220201603021445 76413_11621610201603021500 764

31、13_12172140201603021515 76413_12332310201603021530 76413_12512450201603021545 76413_12512400201603021600 76413_12582510201603021615 76413_12852810201603021630 76413_12142130201603021645 76413_12932890201603021700 76413_125224802.3 空閑態(tài)負(fù)載均衡2.1.5 參數(shù)設(shè)置參數(shù)名參數(shù)全稱級別默認(rèn)值3月15日14：213月15日12:163月15日9：16actIdleLBAc

32、tivation of idle mode load balancing (IdleLB)LNBTSFALSETRUETRUETRUEidleLBCapThreshIdle mode load balancing capacity thresholdLNCEL100100100100idleLBPercentageOfUesPercentage of UE for idle mode load balancingLNCEL070%70%90%idleLBCelResWeightCell reselection weight factor idle mode load balancingLNCEL空空空空idleLBEutCelResWeightEUTRA carrier weight factor idle mode load balancingIRFIM空10070702.1.6 實驗效果2個載波用戶數(shù)相當(dāng)，實現(xiàn)均衡。PERIOD_START_TIMEenb_lcr76413-1CELL_LOAD_ACT_UE_MAXenb_lcr76413-11CELL_LOAD_ACT_UE_MAX2016/3/15 9:0076413-14176413-11382016/3/15 9:1