诺基亚异频负载均衡报告-20160315 - AMLE

1、 诺基亚异频负载均衡报告诺基亚异频负载均衡报告 诺基亚北京项目LTE优化组2016年3月目录1.背景22.负载均衡功能测试32.1异厂家负载均衡功能测试32.1.1参数设置42.1.2实验效果62.2同厂家同站双载波负载均衡功能测试82.1.3参数设置92.1.4实验效果103.遗留问题111. 背景在LTE中，由于小区半径的减少，用户分布不均匀的现象十分严重，经常会出现某个小区负载较重而其邻居负载较低的现象，不仅会降低网络容量而且还会影响到用户的服务质量。上述原因直接促使了负载均衡技术的诞生，在保证用户的服务质量的同时，使网络总容量达到最大化。目前所支持的负载均衡功能如下：Ø iF

2、LB：Inter Frequency Load Balance 异频负载平衡当高负荷小区的负荷超过High Load门限后进入iFLB激活状态，并可以触发LB切换，直到小区负荷低于Target load门限，则退出iFLB激活状态；在iFLB激活状态期间，ENB间的负荷信息不通过X2接口进行交互，所以这种状态下触发的LB切换属于邻区负荷未知的盲切换，只要目标邻区的下行rsrp大于设定的LNHOIF:thresholdRsrpIFLBFilter参数门限就会触发。而当切换请求消息(Handover Request Cause: Reduce Load in Serving Cell)发送给异频的

3、目标邻区时如果邻区负荷已经超过了自己小区设置的Target Load门限的话，邻区会拒绝该切换请求。Ø AMLE：Active Mode Load Equalization主动模式负载均衡小区开通AMLE功能后，当小区的负荷门限高于High Load的时候，小区会触发和异频邻区的负荷信息交换，它通过X2连接获取邻区的CAC信息(即邻区的综合可用容量)，当主小区和异频邻区负荷满足如下条件时触发AMLE的LB切换： 当邻区可用容量与本小区的可用容量差值大于设定参数门限AMLEPR:deltaCac时则触发LB的切换 主小区的可用容量<AMLEPR:maxCacThreshold 邻

4、区的可用容量>= AMLEPR:cacHeadroom UE检测到的目标邻区的下行rsrp大于设定的LNHOIF:thresholdRsrpIFLBFilter参数门限iFLB与AMLE的区别：iFLBAMLE当小区达到高负载门限时，iFLB 提供负载均衡AMLE将小区与配对邻区的负载差异控制在所设的负载差值以内iFLB的目的是把小区的负载控制在所设的负载门限下，而不是平衡小区间的负载候选邻区的筛选过程类似iFLB负载的信息只在同个eNB的小区间分享；对于不同eNB小区使用的是盲切换，不根据邻区的负载情况来判断小区间使用资源状态报告(RSR)来分享负载情况，不使用盲切换，对于没有RSR的

5、邻区将不会被切换2. 负载均衡功能测试2.1 异厂家负载均衡功能测试为进行Nokia和 HW LTE 基站间负载均衡的实验，选定实验点为首都机场T1出发厅。如下图所示，涉及到的Nokia小区为朝阳机场T1F2至F3层公共区NLM（ENB ID：76309），涉及到的HW基站为顺义首都机场T1航站楼F2F3东侧办公餐饮区及出港大厅HLM 499769-132。2.1.1 参数设置Ø 开启feature LTE1531: Inter-frequency Load Balancing Extension（开启iFLB）Parameter NameParameter Full NameMOC

6、默认值修改值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 开启feature LTE1841: Inter-Frequency Load Equalization（开启AMLE）MO ClassParameter NameParameter Full Name默认值修改值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不设置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 实验效果Ø 开启feature LTE1531: Inter-frequency Load Balancing Extension

16、（开启iFLB）开启feature LTE1531后，指标统计Nokia76309-1和HW 499769-132基于iFLB的LB HO全部成功，信令显示触发原因为reduce-load-in-serving-cell，符合预期。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 开启feature LTE1841: Inter-Frequency Load Equalization（开启AMLE）开启feature LTE1841后，指标统计LB HO有尝试计数，信令显示触发原因也为reduce-load-in-serving-cell，但同时也开启了iFLB，为了区分LB基于具体feature，抓取wireshark，Nokia小区有发起资源请求，但未出现厂家间资源信息交互。SDATETIM

19、EENB_CELLHO_LB_ATTHO_LB_SUCCHIGH_CELL_LOAD_LB20160301160076309_100020160301161576309_100020160301163076309_1473615620160301164576309_1554622920160301170076309_100020160301171576309_100076309向HW小区发起的资源请求消息类型为Composite Available Capacity Periodic，周期性综合可用容量。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 同厂家同站双载波负载均衡功能测试为进行Nokia同站内各载波间负载均衡的实验，选定实验点为76413朝阳机场2号航站楼出发厅南侧NLM，该站点两个载波业务量和用户数分布不均。2.1.3 参数设置开启feature LTE1841: Inter-Frequency Load Equalization（开启AMLE）MO ClassParameter NameParameter Full Name默认值修改值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不设置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 实验

28、效果修改后76413两载波用户数实现均衡，1小区用户数下降，PRB利用率下降，同时11小区用户数增加，PRB利用率有所上升。由于是站内切换无明显log显示LB HO，但切换事件均为LB切换的所用事件A4，符合预期。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 空闲态负载均衡2.1.5 参数设置参数名参数全称级别默认值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 实验效果2个载波用户数相当，实现均衡。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