1、HANDOVER PROCESS切換過(guò)程,BSSPAR S9,HANDOVER PROCESS切換過(guò)程 Contents內(nèi)容,1. Overview概述 2. Handover Decision切換判決 3. Target Cell Selection目標(biāo)小區(qū)選擇 4. Algorithms 算法 5. Power Budget Handover功率預(yù)算切換 6. Level & Quality Handover電平&質(zhì)量切換 7. Umbrella Handover傘切換 8. Timers for Handovers 切換記時(shí)器,HANDOVER PROCESS 切換過(guò)程,What is

2、the purpose of HO? 切換的目的是什么? Call continuity 呼叫連續(xù)性 Call quality 呼叫質(zhì)量 Others. 其它,HANDOVER PROCESS切換過(guò)程 Causes原因,Timing Advance,Adjacent Cells,Downlink Quality,Uplink Quality,AV_RXQUAL_UL_HO,AV_RXQUAL_DL_HO,Downlink Level,Uplink Level,AV_RXLEV_UL_HO,AV_RXLEV_DL_HO,AV_RANGE_HO,AV_RXLEV_NCELL(n),QUALITY

3、& INTERFERENCE,LEVEL,DISTANCE,PERIODIC CHECKS,UMBRELLA,POWER BUDGET,IMPERATIVE HO,CHANNEL ADMINISTRATION,DIRECTED RETRY,THRESHOLD COMPARISON,RAPID FIELD DROP,Others其它: Intelligent Underlay Overlay 智能層疊覆蓋 Traffic Reason話務(wù)量原因 .,MS SPEED,MS Speed,AV_MS_SPEED,HANDOVER PROCESS切換過(guò)程 Handover Decision切換判決,H

4、andover process may be triggered by 切換過(guò)程可以由以下因素觸發(fā): Quality, field strength or distance values fall below/exceed their threshold 質(zhì)量,場(chǎng)強(qiáng)或者距離值低于/超過(guò)門(mén)限 Periodic checks周期性檢查 Power budget HO 功率預(yù)算切換 Umbrella HO 傘型切換,HANDOVER PROCESS切換過(guò)程 Handover Priority切換優(yōu)先級(jí),Handover priority切換優(yōu)先級(jí),1. Uplink and downlink Int

5、erference上行和下行干擾 2. Uplink quality上行質(zhì)量 3. Downlink quality下行質(zhì)量 4. Uplink level 上行電平 5. Downlink level 下行電平 6. Distance 距離 7. Rapid Field Drop 快速場(chǎng)強(qiáng)衰落 8. Slow moving MS 慢速移動(dòng)手機(jī) 9. Better cell i.e. Periodic check (Power Budget HO or Umbrella HO) 更好小區(qū),例如:周期性檢查(功率預(yù)算切換或者傘型切換) 10. PC: Lower quality/level th

6、resholds (UL/DL) 質(zhì)量/電平下限(上行/下行) 11. PC: Upper quality/level thresholds (UL/DL)質(zhì)量/電平上限(上行/下行),HANDOVER PROCESS切換過(guò)程 Handover Algorithms切換算法,AV_RXLEV_NCELL(n) hoLevelUmbrella(n),PBGT hoMarginPBGT(n) where PBGT = (msTxPwrMax - msTxPwrMax(n)-(AV_RXLEV_DL_HO - AV_RXLEV_NCELL(n) - (btsTxPwrMax - BTS_TXPWR)

7、,AV_RXLEV_NCELL(n) rxLevMinCell(n) + Max (0, A) A = msTxPwrMax(n) - P P = depending on MS Classmark取決于手機(jī)Classmark,PBGT hoMarginLev/Qual(n) where PBGT = (AV_RXLEV_NCELL(n) - AV_RXLEV_DL_HO)-(btsTxPwrMax - BTS_TXPWR),1.,2.,1.,In all Handover cases (in imperative HO only requirement) 在所有切換中(緊急切換的話是唯一的條

8、件),Except for Umbrella Handover 傘型切換例外,2.,The additional condition 附加條件,HANDOVER PROCESS切換過(guò)程 Target Cell Selection (1)目標(biāo)小區(qū)選擇,If two or more Adjacent cells with equal priorities - Ranking based on radio properties 如果兩個(gè)或者更多鄰區(qū)具有相同優(yōu)先級(jí) 基于無(wú)線特性排隊(duì),Load check of Candidates by btsLoadThreshold (0.100%) 候選小區(qū)的負(fù)

9、荷檢查 If overloaded priority decreased by hoLoadFactor (0.7) 如果超負(fù)荷,則降低優(yōu)先級(jí),Best candidates to RR Management無(wú)線資源管理的最佳候選小區(qū): intra BSC HO max 16 cells under the same BSC as the source cell 同BSC切換時(shí)一個(gè)BSC下最多有16個(gè)小區(qū)作為目標(biāo)小區(qū) inter BSC HO BSC之間切換numberOfPreferredCells,Comparison of priorities of Candidates (hoLeve

10、lPriority (0.7) 候選小區(qū)優(yōu)先級(jí)比較,1.,2.,3.,HANDOVER PROCESS切換過(guò)程 Target Cell Selection (2)目標(biāo)小區(qū)選擇,All cells have equal priority 具有相同優(yōu)先級(jí)的所有小區(qū),cell a b c Rx_Level -75 -80 -83 1. Load overl. overl. n.overl. hoLoadFactor 1 1 1 2. Priority 3 3 3 New Priority 2 2 3 3. Rx_Level -75 -80 = cell list c , a ,b,One cell

11、has higher priority because of some reason一個(gè)小區(qū)因?yàn)槟撤N原因而具有更高優(yōu)先級(jí),cell a b c Rx_Level -75 -80 -83 1. Load n./overl. n.overl. n.overl. hoLoadFactor 2 1 1 2. Priority 4 3 3 New Priority 4/2 3 3 3. Rx_Level -75 -80/-80 -83 = cell list a,b,c (if cell a is not overload) = cell list b,c,a,PBGT = (msTxPwrMax- m

12、sTxPwrMax(n) - (AV_RXLEV_DL_HO-AV_RXLEV_NCELL(n) - (btsTxPwrMax - BTS_TXPWR) PBGT = (33dBm-33dBm)-(-90 - -80)-(42dBm-42dBm) = 10 dB 10 dB 6 dB OK !,AV_RXLEV_NCELL(n) rxLevMinCell(n) + Max (0, msTxPwrMax(n) - msTxPwrMax) -80 dBm -99 dBm + (33 dBm - 33 dBm) = -99 dBm,1.,2.,Equations 1 and 2 are used 使

13、用方程1和2,AV_RXLEV_DL_HO = -90 dBm msTxPwrMax = 33 dBm (= 2W) btsTxPwrMax = 42 dBm (= 16 W) BTS_TX_PWR = 42 dBm = (16 W) hoMarginPBGT(n) = 6 dB,Serving Cell服務(wù)小區(qū):,Best Adjacent Cell最佳相鄰小區(qū):,AV_RXLEV_NCELL(n) = -80 dBm rxLevMinCell(n) = -99 dBm msTxPwrMax(n) = 33 dBm (= 2W) btsTxPwrMax = 42 dBm (= 16 W),H

14、ANDOVER PROCESS切換過(guò)程 Power Budget Handover (1)功率預(yù)算切換,HANDOVER PROCESS切換過(guò)程 Power Budget Handover 功率預(yù)算切換(2),Trigger 觸發(fā) Periodic Check周期性檢查 ( hoPeriodPBGT ) Candidate Selection 候選小區(qū)選擇 Equation 1 & 2 used 使用方程1和2 Priority and Load Considered 考慮優(yōu)先級(jí)和負(fù)載 Typically used between cells of the same “Layer“ 用于同層的

15、不同小區(qū)之間,hoPeriodPBGT 1 . 63 (SACCH Period) enablePwrBudgetHandover Y / N,Parameter Value,rxLevMinCell(n) -110 -47 dBm msTxPwrMax(n) 5 43 dBm hoMarginPBGT(n) -24 24 dB,HANDOVER PROCESS切換過(guò)程 Handover due to Level (1/2)由于電平的切換,Trigger 觸發(fā) Threshold Comparison 門(mén)限比較 ( hoThresholdsLevUL/DL (px - nx) ) Candid

16、ate Selection 侯選小區(qū)選擇 Equation 1 used 使用方程1 Equation 2 used if enableHoMarginLevQual = N 使用方程2 Equation 2 with hoMarginLev used if enableHoMarginLevQual = Y Priority and Load Considered 考慮優(yōu)先級(jí)和負(fù)載,hoThresholdLevUL/DL -110 -47 px 1 32 nx 1 32,Parameter Value,rxLevMinCell(n) -110 -47 dBm msTxPwrMax(n) 5

17、43 dBm hoMarginLev(n) -24 24 dB,HANDOVER PROCESS切換過(guò)程 Handover due to Level (2/2),Equations 1 and 2 are used if parameter enableHoMarginLevQual is set “Yes” 如果參數(shù)enableHoMarginLevQual設(shè)為”Yes”則使用方程1和2,2 dB,hoMarginLev = 4 dB,Trigger for Handover due to Level 觸發(fā)由于電平的切換,A,B,= Cell B is not selected as can

18、didate for HO due to level since 2dB 0 dB B小區(qū)選為質(zhì)量切換的潛在侯選小區(qū),因?yàn)?dB0dB,Threshold (Lev) -95 dBm,HANDOVER PROCESS切換過(guò)程 Handover due to Interference干擾切換 (1/2),Trigger觸發(fā) : Threshold Comparison門(mén)限比較 Threshold Comparison for Quality 質(zhì)量門(mén)限切換 ( hoThresholdsQualUL/DL (px - nx) ) Threshold Comparison for Level 電平門(mén)限

19、切換( hoThresholdsInterferenceUL/DL (px - nx) ) Candidate Selection 候選小區(qū)選擇 Priority InterCell / Intracell selected at BSC independently UL / DL BSC上下行小區(qū)間/小區(qū)內(nèi)優(yōu)先級(jí) Priority Inter Quality HO if Any Target Otherwise Intra Cell HO,enableIntraHoInterfUL/DL Y / N hoThresholdInterferenceUL/DL -110 -47 px 1 32

20、nx 1 32,Parameter Value,hoPreferenceOrderInterfUL/DL INTER / INTRA BSC,Priority Intra Intra Cell HO小區(qū)內(nèi)切換,HANDOVER PROCESS切換過(guò)程 Handover due to Interference干擾切換 (2/2),Equations 1 and 2 are used if parameter enableHandoverMarginQual is set “Yes” 如果參數(shù)enableHandoverMarginQual設(shè)為”Yes”則使用方程1和2,hoThresholdQu

21、al = 4 hoThresholdInterferenceDL = -85 dBm hoPreferenceOrderInterfDL = intra,Trigger for Handover due to Interference 干擾切換觸發(fā),A,B,- Field strength higher than threshold場(chǎng)強(qiáng)高于門(mén)限 - Bad quality 質(zhì)量差 = Interference 干擾 = intra cell handover ! 小區(qū)內(nèi)切換,Threshold (Interference Lev) -85 dBm,5,0,HANDOVER PROCESS,Pa

22、rameters,enableBSSHandoverControl enableIntracellHandover enablePwrBudgetHandover enableMSDistanceHandover enableSDCCHHandover enableUmbrellaHandover,hoPeriodPBGT(HPP) hoPeriodUmbrella(HPU),Parameter,Value,hoThresholdsLevDL/UL(LDR/LUR) rxLevel px(LDP,LUP) 默認(rèn)是1 nx(LDN,LDP) 默認(rèn)是1,-110 . -47 (dBm) 1 . 3

23、2 1 . 32,Yes/No Yes/No Yes/No Yes/No Yes/No Yes/No,0 . 63 (SACCH periods) 0 . 63 (SACCH periods),HANDOVER PROCESS,Parameters, continued,Parameter,Value,hoThresholdsQualDL/UL rxQual px nx,0 . 7 1 . 32 1 . 32,msDistanceHoThresholdParam msRangeMax px nx,0 . 63 (TA) 1 . 32 1 . 32,-110 . -47 (dBm) 1 . 32 1 . 32,hoThresholdsInterferenceDL/UL rxLevel px nx,HANDOVER PROCESS,Parameters, continued,Parameter,Value,minIntBetweenHoReq,0 . 30 (s),minInt