中中级级培培训训第第二二模模块块之之二二参参 数数课程时间课程时间l08:15开始l12:45结束l15:00开始l17:30结束l约二天时间。CHANNEL CONFIGURATIONSContents Time Slots Burst2 Signaling Channels1 TDMA frame TCH/F, TACH SDCCH/8, SDCCH/4, CBCH ( 2nd phase GSM ) BCCH/CCCH3 Traffic Channels 4 Parameters Logical ChannelsCHANNEL CONFIGURATIONSTime Slots and Frames01224 2501249 5007Hyperframe = 2048 SuperframesSuperframe = 26x51 or 51x26 Multiframes26 Multiframe = 120 ms51 Multiframe = 235 msTDMA frame = 4.615 msTCHSIGN.CHANNEL CONFIGURATIONSBurst Period07TDMA frame = 4.615 ms= BURST PERIOD000fsCHANNEL CONFIGURATIONSLogical Channels, Downlink BSS - MSBCHCCCHFCCHSCHBCCHPCHAGCHDCCHTCHSDCCHSACCHFACCHTCHTCHCOMMON CHANNELSDEDICATED CHANNELSCHANNEL CONFIGURATIONSLogical Channels, Uplink MS - BSSCCCHRACHDCCHTCHSDCCHSACCHFACCHTCHTCHCOMMON CHANNELSDEDICATED CHANNELSlFCCHFCCH频率校正信道：给提供一个标志，使它们在若干之间发现包含广播传输的，频率校正信道：给提供一个标志，使它们在若干之间发现包含广播传输的，移动台开机后，搜寻这个信号移动台开机后，搜寻这个信号lSCHSCH同步信道同步信道: :包含基站识别码包含基站识别码BSICBSIC和简化的和简化的TDMATDMA帧号帧号.BSIC.BSIC用于识别不同的小区用于识别不同的小区,TDMA,TDMA帧号用于话帧号用于话间加密间加密. .lBCCHBCCH广播控制信道广播控制信道: :包含了详细的网络和小区信息包含了详细的网络和小区信息, , 如如: :服务区和邻小区的频率服务区和邻小区的频率. . 跳频序列跳频序列, ,信道组信道组合方式合方式,COMBINE ,COMBINE 等等; ; 寻呼组寻呼组, ,通常一个小区有多个寻呼信道通常一个小区有多个寻呼信道, ,为了防止移动台为了一个寻呼消息而为了防止移动台为了一个寻呼消息而侦听所有的寻呼信道侦听所有的寻呼信道, ,寻呼信道以只有某一组移动台侦听某一特定的寻呼信道的方式分开寻呼信道以只有某一组移动台侦听某一特定的寻呼信道的方式分开; ;邻小区邻小区信息信息,MS,MS必须知道目前小区的邻区是什么必须知道目前小区的邻区是什么, ,以及它们广播频率以及它们广播频率. .lPCHPCH寻呼信道寻呼信道: :下行下行, ,寻呼用户时用寻呼用户时用, ,它是由位置区的所有它是由位置区的所有BTSBTS广播的广播的. .lRACHRACH随机接入信道随机接入信道:CCCH:CCCH中唯一的上行链路中唯一的上行链路. .用于用于MSMS启动一事务启动一事务, ,主叫主叫, ,或作为或作为PCHPCH的应答的应答. .lAGCHAGCH准许接入信道准许接入信道; ;为为MSMS指派一个指派一个SDCCH,SDCCH,是下行的是下行的. .lSDCCHSDCCH独立专用控制信道独立专用控制信道, ,用于呼叫建立用于呼叫建立, ,鉴权鉴权, ,位置更新位置更新,TCH,TCH分配分配, ,短消息短消息. .lSACCHSACCH慢随路控制信道慢随路控制信道:SACCH:SACCH伴随着伴随着SDCCHSDCCH和和TCH,TCH,用于发送测量报告用于发送测量报告, ,功率控制功率控制, ,时间校准时间校准,MS,MS通话时通话时发送短信发送短信. .lFACCHFACCH快随路控制信道快随路控制信道: :用于切换时用于切换时, ,它与一个它与一个TCHTCH对应对应, ,代替代替20MS20MS的话间的话间, ,工作于偷帧模式工作于偷帧模式. .lTCHTCH业务信道业务信道: :传送话音与数据传送话音与数据,TCHF,TCHF是全速是全速13.3Kbit/s,TCHH13.3Kbit/s,TCHH是半速率是半速率5.6, EFR5.6, EFR增加型全速率增加型全速率,13.3,13.3,但编码方式与全速率不同但编码方式与全速率不同, ,在话音质量上有更一步提高在话音质量上有更一步提高. .CHANNEL CONFIGURATIONSConfiguration of Signalling Channels07Separated ConfigurationCombined Configuration07ts0=bcch/pch/agchts1=sdcch/8ts0=bcch/sdcch/4/pch/agchCHANNEL CONFIGURATIONS Combined CCCH/SDCCH/4 Multiframef sbbb bcfcfcscc cccccc fcfs t t t tttt t ff t t t tttt t fsf s ss ssss sst tttr r sfssss s sr rrrr r rsfr r r r rrrr r rf r r r rtrt t trf t t t rtrt ttDownlinkUplinkCHANNELS f = FCCH b = BCCH r = RACH i=idle s = SCH/SACCH c = CCCH t = SDCCH/451 TDMA frames = 235 mst0501.2.3.4.if sbbbb cfcfcsc cc cccc c fcfsc c c cccc c ff c cccccc c fsf c c ccccc csr rrrr r rfrrrr r r r rrrr r rrfr r r r rrrr r rf r r r rrrr r rrf r r r rrrr rrDownlinkUplinkCHANNELS f = FCCH b = BCCHr = RACH i=idle s = SCH c = CCCH = PCH/AGCH51 TDMA frames = 235 msr050CHANNEL CONFIGURATIONSBCCH/CCCH MultiframeiCHANNEL CONFIGURATIONS SDCCH/8 Multiframet tttt t tftttt t t t tttt t ttft t t t tttt t tf s s s ssss ssf ss ss sssssss ssfsssstttt t tsft t t t tttt t tf t t t tttt t ttf t t t tttt ttDownlinkUplinkCHANNELS t = SDCCH/8 s = SACCH/8i=idlett51 TDMA frames = 235 mss1.2.3.5.6.7.8.4.050iiiiiiCHANNEL CONFIGURATION Number of Blocks for AGCH onlyf sbbbb cfcfcsc cc cccc c fcfsc c c cccc c ff c cccccc c fsf c c ccccc csBCCH/CCCHCHANNELS f = FCCH b = BCCHt = SDCCH/4i=idle s = SCH/SACCH c = CCCH = PCH/AGCH51 TDMA frames = 235 msf sbbbb cfcfcsc cc cccc c fcfst t t tttt t ff t t t tttt t fsf s s sssss ss123456789123BCCH/SDCCH/4iiCHANNEL CONFIGURATIONS Full Rate Traffic Channel (TCH) Multiframet tttt t tftttttttt t ttft t t ttDownlink and UplinkCHANNELS t = TCH s = SACCH i=idle ts26 TDMA frames = 120 ms025iCHANNEL CONFIGURATIONS Half Rate Traffic Channel (TCH) MultiframeDownlink and UplinkCHANNELS t = TCH s = SACCH i=idle 26 TDMA frames = 120 ms025Downlink and UplinkCHANNELS t = TCH s = SACCH i=idle 26 TDMA frames = 120 ms025t tttt t ttttttttt t ttttt tttt tttt t ttttttttt t ttttt tttstitCHANNEL CONFIGURATIONSSDCCH Capacity Location updates Short Message Service imsi attached/detached Call setupSDCCH used inCHANNEL CONFIGURATIONSSDCCH Capacity (a)lExample (Call establishment and Location Update included)Call Establishment2 TRXs / Cell 8,11 Erl / Cell (1% Blocking probability)1,5 min / Subs / BH = 25 mErl. / Subs8,11 Erl / Cell /25 mErl. / Subs = 325 Subs / CellAuthentication and Ciphering = 7 sec = 1,94 mErl / Call (SDCCH reservation time)= 325 Calls / Cell * 1,94 mErl / Call = 0,6305 Erl / Cell (SDCCH)Location UpdateLocation Updates once in 60 minutes ( parameter timerPeriodicUpdateMS )325 Subs / CellSDCCH reservation time for Location Update = 7 sec = 1,94 mErl= 325 Calls / Cell * 1,94 mErl / Call = 0,6305 Erl / Cell (SDCCH)lCall Establishment and Location Update together 0,632 Erl + 0,632 Erl = 1,261 Erl / CellWith 1% Blocking Probability ( Erlang B table ) = 5 SDCCH / CelllCombined BCCH/SDCCH channel structure is not possible in this case !lSeparate Configuration (1 BCCH/CCCH and 1 SDCCH/8) is needed!CHANNEL CONFIGURATIONSErlang B TableCHANNEL CONFIGURATIONSSDCCH Capacity (b)lExample (Call establishment and Location Update included)Call Establishment2 TRXs / Cell 8,11 Erl / Cell (1% Blocking probability)1,5 min / Subs / BH = 25 mErl. / Subs8,11 Erl / Cell /25 mErl. / Subs = 325 Subs / CellAuthentication and Ciphering = 7 sec = 1,94 mErl / Call (SDCCH reservation time)= 325 Calls / Cell * 1,94 mErl / Call = 0,6305 Erl / Cell (SDCCH)Location UpdateLocation Updates once in 120 minutes ( parameter timerPeriodicUpdateMS )325 Subs / CellSDCCH reservation time for Location Update = 7 sec = 1,94 mErl= 325 Calls / Cell * 1,94 mErl / Call * 1/2 = 0,31525 Erl / Cell (SDCCH)lCall Establishment and Location Update together 0,6305 Erl/Cell + 0,31525 Erl/Cell = 0,94575 Erl/Cell (SDCCH)With 1% Blocking Probability ( Erlang B table ) = 4 SDCCH / CelllCombined BCCH/SDCCH channel structure is possible in this case !CHANNEL CONFIGURATIONSSDCCH Capacity (c)lExample (Call establishment and Location Update included)Call Establishment2 TRXs / Cell 8,11 Erl / Cell (1% Blocking probability)1,5 min / Subs / BH = 25 mErl. / Subs8,11 Erl / Cell /25 mErl. / Subs = 325 Subs / CellAuthentication and Ciphering = 7 sec = 1,94 mErl / Call (SDCCH reservation time)= 325 Calls / Cell * 1,94 mErl / Call = 0,6305 Erl / Cell (SDCCH)Location UpdateLocation Updates once in 120 minutes ( parameter timerPeriodicUpdateMS )325 Subs / CellSDCCH reservation time for Location Update = 7 sec = 1,94 mErl= 325 Calls / Cell * 1,94 mErl / Call * 1/2 = 0,31525 Erl / Cell (SDCCH)SMSSMS traffic estimation 1.0 mErl / subscriber= 325 Calls / Cell * 1 mErl / Call = 0,325 Erl / Cell (SDCCH)lCall Establishment, Location Update and SMS together 0,6305 Erl/Cell + 0,31525 Erl/Cell + 0,325 Erl/Call = 1,27075Erl/Cell (SDCCH)With 1% Blocking Probability ( Erlang B table ) = 5 SDCCH / CelllSeparated channel structure is possible in this caseCHANNEL CONFIGURATIONSPaging CapacitylExampleCombined BCCH / SDCCH ConfigurationOne Block Reserved for AGCH = 2 Blocks for PCHPaged Mobile Stations per Paging_Request Message : From 2 to 4, in Average 3 In Average 2 Pages per Mobile Station 3 Pages/Blocks * 2 Blocks = 6 Pages every 51-frames Multiframe ( 235 ms. )2 Pages / Paged MS = 3 Paged MS every 235 ms.( ( 3600 * 1000 ) / 235 ) * 3 = 45，957 Paged MS per Hour.lWorst Case All Transactions are Mobile TerminatingAll Cells in Location Area get the same PCH LoadlCapacityWith one TRX 2,95 Erl. 25 mErl. / subs. = 120 subscribersBTS MS Paging_RequestBTS3MS2 Paging_RequestCapacity of PCH calculated for a Location AreaCHANNEL CONFIGURATIONNumber Of Blocks for Access Grantf sbbbb cfcfcsc c c cccc c fcfsc cc ccccc ff c cc cccc c fsf c c ccccc csBCCH/CCCHCHANNELS f = FCCH b = BCCH t = SDCCH/4 s = SCH/SACCH c = CCCH = PCH/AGCH51 TDMA frames = 235 msf sbbbb cfcfcsc c c cccc c fcfst t t tttt t ff t t t tttt t fsf s s sssss ss123456789123BCCH/SDCCH/4CHANNEL CONFIGURATIONS CCCH Improvements (1)numberOfBlocksForAccessGrant= 0 , settingPages used to have always priority in CCCH blocks no matter what numberOfBlocksForAccessGrant setting was. Now ,If numberOfBlocksForAccessGrant =0 then AGCH messages would have priority over PCH messages.If numberOfBlocksForAccessGrant 0 then PCH messages would have priority over AGCH messages . Thus capacity can be dynamically shared between PCH and AGCH = better throughput for PCH especially for combined-BCCHCHANNEL CONFIGURATIONSNumber of Multiframes Between Pagingl# of 51 TDMA frame multiframes (2.9) between transmissions of Paging_Request messages to mobiles of the same paging group.# of paging groups = numberOfBlocksForAccessGrant * noOMultiframesBetweenPaging= Page / group every 2 . 9 * 235 ms = 0.47 . 2.115 slMobile Station calculates its Paging Group based on IMSI and on the Number of Paging Groups.CHANNEL CONFIGURATIONSNumber of Multiframes Between PaginglAffects of the # of the Paging GroupsBattery Consumption of the Mobile Station手机省电Speed of Call Setups 呼叫速度根据CCCH、AG和MFR的定义，可以计算出每个小区寻呼子信道的个数：当CCCH与SDCCH共用一个物理信道时：（3AG）MFR。当CCCH不与SDCCH共用物理信道时：（9AG）MFR。当参数MFR越大，小区的寻呼子信道数也越多，相应属于每个寻呼子信道的用户数越少（参见GSM规范05.02寻呼组计算方式），因此寻呼信道的承载能力加强,上述优点的获得是以牺牲寻呼消息在无线信道上的平均时延为代价的，即MFR越大使寻呼消息在空间段的时间延迟增大，系统的平均服务性能降低。 l设置MFR时建议参考下列原则：lMFR的选择以保证寻呼信道不发生过载为原则，在此前提下应使该参数尽可能小。l一般建议：对寻呼信道负载很大的地区（通常指话务量很大的区域）， MFR设置为8或9（即以8个或9个复帧作为寻呼组的循环）；对寻呼信道负载一般的地区（通常指话务量适中的区域），MFR设置为6或7（即以6个或7个复帧作为寻呼组的循环）；对寻呼信道负载较小的地区（通常指话务量较小的区域），MFR设置为4或5（即以4个或5个复帧作为寻呼组的循环）。l在运行的网络中应定期测量寻呼信道的过载情况，并以此为根据适当调整 MFR的数值。CHANNEL CONFIGURATIONSRACH ControllingRET:Number of retransmission = maxNumberRetransmission (1, 2, 4, 7)当对信道请求无响应时，允许手机重发请求的最大次数当对信道请求无响应时，允许手机重发请求的最大次数 SLO:window = numberOfSlotsSpreadTrans (3 . 12, 14, 16, 20, 25, 32, 50)001 RACH (Re)transmission during the window= Total time for RACH = maxNumberRetransmission * numberOfSLotsSpreadTrans +.TDMA-framesl三个参数，即：发送分布时隙数SLO、最大重发次数RET和与参数SLO及信道组合有关的参数S。 CCH信道组合方式SLONOT COMBINECOMBINE3，8，14，5055414，9，16，76525，10，20，109586，11，25，163867，12，32，217115l参数SLO越大，移动台发送信道请求消息之间的间隔的变化范围越大，RACH冲突的次数相应减少。参数S越大，移动台发送信道请求消息之间的间隔越大，RACH信道上的冲突减少，然而，参数SLO和S的增大却会延长移动台的接入时间，从而导致整个网络的接入性能下降，因此必须选择合适的SLO和S。CHANNEL CONFIGURATIONSParameters Related to Signalling noOfMultiframesBetweenPaging 2 . 9 numberOfBlocksForAccessGrant 0 . 7 (if BCCH/CCCH used) 0 . 2 (if combined BCCH/SDCCH used) maxNumberRetransmission 1, 2, 4, 7 (RACH control) numberOfSlotsSpreadTrans 3 . 12, 14, 16, 20, 25, 32, 50 (RACH control)ParametersValueIDLE MODE l什么是手机开机没有专用连接会选择一个最适合的小区接入以收听下行上的系统信息，需要时可发起呼叫，当被叫时可被网络定位的三个任务：选网小区选择和小区重选位置更新locationAreaId ncc (Network Colour Code)0 7 bcc (BTS Colour Code)0 7bsIdentityCodecell-ID0 65535ParameterValuetrainingSequenceCode0 7IDLE MODE OPERATION IDs and ID Codes mcc (Mobile Country Code)0 999 mnc (Mobile Network Code)0 99 lac (Location Area Code)0 65535Cell Global IdentityMCC + MNC + LAC + CIIDLE MODE OPERATIONBaseStation Identity Code (BSIC) BSIC is a combination of NCC and BCC Reported in Measurement Results to BSC Can be listed in Hex or DecimalIDLE MODE OPERATIONBase Station Colour CodeMNC = OperatorMCC = Country e.g FinlandLAC 1 = HelsinkiLAC 2LAC 3LAC 4f1f2f3f1f1bcc = 1bcc = 2bcc = 3Neighbour list of f3:f1f2.Location Area CodeBSCBTSBTSBTS12n initialFrequency 1 . 124 GSM 900 512 885 GSM 1800 512 810GSM 1900ParameterValuebCCHAllocation-ID 1 . 128 in GSM（S11.5：660）bCCHAllocationList 1 . 124(FREQ) in GSM ( max. 32 freq. for all bands)idleStateBCCHAllocation (IDLE) 0 (BCCH list is taken from the adjacent cell) 1 . 128 (number of the BCCH list used)measurementBCCHAllocation(ACT)ADJ (BCCH frequency list taken from adj. cell)IDLE (active MS uses the same list as MS in IDLE mode)IDLE MODE OPERATION Frequencies plmnpermitted（PLMN） 0 . 7Parameter ValueIDLE MODE OPERATION PLMN SelectionlTwo ModesAutomaticManual该参数的设置不当可能是引起掉话的主要原因之一。IDLE MODE OPERATION Cell Selection in Idle ModeTwo methods:a) Normal cell selectionb) Stored list cell selection (opt)If no suitable cell found with with method b) then a) is tried.b)搜寻上次关机时,手机中存的那个频点,如果没有进行a)所有频点全听,找一个最好的.IDLE MODE OPERATION Suitable cell to camp on Cell is in the selected PLMN Cell is not barred It is not in a forbidden location area for national roaming 位置区是允许的 C1 0IDLE MODE OPERATION Cell BarredExisting Layer Barred, NoNew Microcell Layer Barred, YesCall setup on macro, GPS-satellite Measurement SystemcellBarQualify Y cell bar can be overridden不考虑不考虑CELLBAR(C2) N cell bar can not be overridden 要听要听CELLBARExampleAveraging 3-5 s.Decision 5s.IDLE MODE OPERATION Cell Selection in Idle Mode- ImplementationlRadio CriteriaC1 = (A - Max(B,0)lA = Received Level Average - p1lB = p2 - Maximum RF Output Power of the Mobile Stationlp1 = rxLevelAccessMin Min. received level at the MS required for access to the systemlp2 = msTxPowerMaxCCHMax. Tx power level an MS may use when accessing the systemrxLevelAccessMin （RXP） -110 . -47msTxPowerMaxCCH 5 43Parameter ValueIDLE MODE OPERATION Cell Re-selection in Idle ModeCell re-selection is needed if Path Loss criterion C1 0 for cell camped on ,for more than 5 seconds.连续5S,C1最大重传次数MS will calculate the C1 and C2 for the serving cell, every 5 sMS will calculate the C1 and C2 for the neighbour cells, every 5 scellReselectParamInd (PI) Y C2 reselection parameters are broadcast N C2 reselection parameters are not broadcastcellReselectOffset （REO） 0 . 126 (dB) 2 dB steppenaltyTime （PET） 20 . 640 (s)20 s steptemporaryOffset （TEO） 0 . 70 (dB) 10 dB step (the value is negative)Parameter ValueC1 + cellReselectOffset - temporaryOffset*H(penaltyTime-T) = penaltyTime 640 C2 =C1 - cellReselectOffset penaltyTime = 6401 when T penaltyTime IDLE MODE OPERATION Cell Re-selection with C2, continuesIDLE MODE OPERATION Cell Re-selection cellReselectHysteresis (0 14 dB) (mentioned in RR Management in IDLE mode Control).2dB stepA = 4 dBB = 6 dBC = 8 dB ABC 1212MS MovingAB CLA1LA2IDLE MODE OPERATION Cell Re-selectioncellReselectHysteresis (0 14 dB)cellReselectHysteresisThe nominal LA borderThe real LA borderL1L2timerPeriodicUpdateMS 0.0 . 25.5 (hours)allowIMSIAttachDetach Yes/NoParameter ValueIDLE MODE OPERATION Location UpdatelMS = MSC / VLRlMobile Station switched ONNo IMSI Attach / DetachSame Location Area = No Location UpdateDifferent Location Area = Location UpdatelChange of the Location AreaLocation Area under the same MSC / VLRLocation Area under another MSC /VLR = HLR will be updatedService is rejected (MS unknown in VLR)lTime Periodic (MS - MSC/VLR)lGSM系统中发生位置更新的原因主要有两类，一种是移动台发现其所在的位置区发生变化（LAC不同）；另一种是网络规定移动台周期地进行位置更新。周期位置更新的频度是由网络控制的，周期长度由参数PER确定。 lPER的取值范围为6分钟25小时30分，以6分钟为步长。lPER设置为0表示小区中不用周期的位置更新。l周期位置更新是网络与移动用户保持紧密联系的一种重要手段，因此周期时间越短，网络的总体服务性能越好。但频繁的周期更新有两个负作用：一是网络的信令流量大大增加，对无线资源的利用率降低，在严重时会直接影响系统中各个实体的处理能力（包括MSC、BSC和BTS）；另一方面则使移动台的功耗增大，使系统中移动台的平均待机时间大大缩短。因此PER的设置需权衡网络各方面的资源利用情况而定。lIMSI分离过程是指移动台向网络通告它正从工作状态进入非工作状态（通常指关机过程），或SIM卡已从移动台中取出的过程。网络在收到移动台的通告后将指示该IMSI用户处于非工作状态，因此以该用户作为被叫的接续请求将被拒绝。与分离过程相应的是IMSI结合过程，它是指移动台向网络通告它已进入工作状态（通常指开机过程），或SIM卡再次被插入移动台。移动台重新进入工作状态后将检测当前所在位置区（LAI）是否和最后记录在移动台中的LAI相同，若相同则移动台启动IMSI结合过程，否则移动台启动位置更新过程（代替IMSI结合过程）。网络接收到位置更新或IMSI结合过程后，将指示该IMSI用户正处于工作状态。l参数ATT用于通知移动台，在本小区内是否允许进行IMSI结合和分离过程。lATT的取值有2种，即是或否（YES/NO）。NO表示不允许移动台启动IMSI结合和分离过程；YES则表示移动台必须启用结合和分离过程。ATT标志通常应设置为YES，以便在移动台关机后网络不再处理以该用户为被叫的接续过程，这样不仅节约了网络各个实体的处理时间，还可以大大节约网络的许多资源（如寻呼信道等）。lATT的设置必须注意：在同一位置区的不同小区其ATT设置必须相同。因为，移动台在ATT为YES的小区中关机时启动IMSI分离过程，网络将记录该用户处于非工作状态并拒绝所有以该用户为被叫的接续请求。若移动台再次开机时处于它关机时的同一位置区（因此不启动位置更新过程）但不同的小区，而该小区ATT设置为NO，因此移动台也不启动IMSI结合过程。在这种情况下，该用户将无法正常成为被叫直到它启动位置更新过程。HANDOVER PROCESSWhat is the purpose of HO?Call continuityCall qualityOthers.容量容量.HANDOVER PROCESSCausesTiming AdvanceAdjacent CellsDownlink QualityUplink QualityAV_RXQUAL_UL_HOAV_RXQUAL_DL_HODownlink LevelUplink LevelAV_RXLEV_UL_HOAV_RXLEV_DL_HOAV_RANGE_HOAV_RXLEV_NCELL(n)QUALITY&INTERFERENCELEVELDISTANCEPERIODICCHECKS周期性UMBRELLAPOWER BUDGETIMPERATIVE HO强制CHANNEL ADMINISTRATIONDIRECTED RETRYTHRESHOLD COMPARISON比较门限RAPID FIELD DROPOthers:Intelligent Underlay OverlayTraffic Reason .MS SPEEDMS SpeedAV_MS_SPEEDHANDOVER PROCESSHandover Decision Handover process may be triggered by 比较门限比较门限Quality, field strength or distance values fall below/exceed their threshold周期性检查周期性检查 Periodic checksPower budget HOUmbrella HOHANDOVER PROCESSHandover Priority Handover priority1. Uplink and downlink Interference干扰干扰2. Uplink quality上行质量上行质量3. Downlink quality下行质量下行质量4. Uplink level 上行电平上行电平5. Downlink level下行电平下行电平6. Distance距离距离7. Rapid Field Drop快衰落快衰落8. Slow moving MS慢速移动慢速移动9. Better cell i.e. Periodic check (Power Budget HO or Umbrella HO)周期性检查周期性检查10. PC: Lower quality/level thresholds (UL/DL)上下行质量功控上下行质量功控11. PC: Upper quality/level thresholds (UL/DL) 上下行电平功控上下行电平功控HANDOVER PROCESSHandover AlgorithmsAV_RXLEV_NCELL(n) hoLevelUmbrella(n)PBGT hoMarginPBGT(n) wherePBGT = (msTxPwrMax - msTxPwrMax(n)-(AV_RXLEV_DL_HO - AV_RXLEV_NCELL(n) - (btsTxPwrMax - BTS_TXPWR)AV_RXLEV_NCELL(n) rxLevMinCell(n) + Max (0, A)A = msTxPwrMax(n) - P P = depending on MS 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)Except for Umbrella Handover2.The additional conditionIf enableHoMarginLevQual = YPBGT = (msTxPwrMax- msTxPwrMax(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 dBm1.2.AV_RXLEV_DL_HO = -90 dBmmsTxPwrMax = 33 dBm (= 2W)btsTxPwrMax = 42 dBm (= 16 W)BTS_TX_PWR = 42 dBm = (16 W)hoMarginPBGT(n) = 6 dBServing Cell:Best Adjacent Cell:AV_RXLEV_NCELL(n) = -80 dBmrxLevMinCell(n) = -99 dBmmsTxPwrMax(n) = 33 dBm (= 2W)btsTxPwrMax(n) = 42 dBm (= 16 W)HANDOVER PROCESSPower Budget Handover (1)HANDOVER PROCESSPower Budget Handover (2)lTrigger Periodic Check ( hoPeriodPBGT )lTypically used between cells of the same LayerhoPeriodPBGT (HPP)1 . 63 (SACCH Period)enablePwrBudgetHandover (EPB)Y / NParameterValuerxLevMinCell(n) (SL)-110 -47 dBmmsTxPwrMax(n) (PMAX1) 5 43 dBmhoMarginPBGT(n) (PMRG)-24 24 dB参数参数PRIPRI、OFOF、BLT BLT PRI、OF、BLT：定义了切换时候选小区的动态优先级，当一个小区拥塞时，可以调整其对比较空闲的相邻小区的优先级，使其容易切出，也可以调整相邻小区对之切换优先级，使其不容易切入，从而减少了本小区的拥塞。 PRI：切换优先级，其取值范围为07，7为最高，为了缓解拥塞，可以适当提高PRI值，不过，要切入的邻区属于业务量比较小的基站，也可以降低它作为邻区的切换优先级. OF：优先级PRI降低的因子，可以根据需要设置。 BLT：BTS的负荷门限，即当切换的目标小区的资源利用率小于或等于BLT时，其切换优先级不变；当切换的目标小区的资源利用率大于BLT时，其切换优先级PRI降低OF级。BLT的设置要配合小区载频数和拥塞程度来优化，当配置较小或拥塞较大时，可以适当小一点，配置较大或拥塞较小时，可以适当大一点。HANDOVER PROCESSTarget Cell Selection (2) All cells have equal prioritycellabc Rx_Level-75-80-831. Loadoverl.overl.n.overl. hoLoadFactor1112. Priority333 New Priority2233. Rx_Level-75-80 = cell list c , a ,b One cell has higher priority because of some reason cellabc Rx_Level-75-80-831. Loadn./overl. n.overl. n.overl. hoLoadFactor2112. Priority433 New Priority 4/2333. Rx_Level-75-80/-80 -83 = cell list a,b,c (if cell a is not overload)= cell list b,c,a HANDOVER PROCESSHandover due to Level (1/2)lTrigger Threshold Comparison ( hoThresholdsLevUL/DL (px - nx) )lCandidate SelectionEquation 1 used Equation 2 used if enableHoMarginLevQual = NEquation 2 with hoMarginLev used if enableHoMarginLevQual = YPriority and Load Considered hoThresholdLevUL/DL (LDR/LUR)-110 -47px (LDP/LUP)1 32nx (LDN/LUN)1 32ParameterValuerxLevMinCell(n) (SL)-110 -47 dBmmsTxPwrMax(n) (PMAX1) 5 43 dBmhoMarginLev(n) (LMRG)-24 24 dBHANDOVER PROCESSHandover due to Level (2/2)Equations 1 and 2 are used if parameter enableHoMarginLevQual is set “Yes” 2 dBhoMarginLev = 4 dBTrigger for Handover due to LevelAB= Cell B is not selected as candidate for HO due to level since 2dB Cell B is selected as potential candidate for HO due to Quality since 2 dB 0 dB Threshold (Lev)-95 dBmHANDOVER PROCESSHandover due to Interference (1/2)lTrigger : Threshold Comparison Threshold Comparison for Quality ( hoThresholdsQualUL/DL (px - nx) )Threshold Comparison for Level ( hoThresholdsInterferenceUL/DL (px - nx) )lCandidate SelectionPriority InterCell / Intracell selected at BSC independently UL / DL Priority InterQuality HO if Any Target Otherwise Intra Cell HOenableIntraHoInterfUL/DL (EIC/EIH)Y / NhoThresholdInterferenceUL/DL (IUR/IDR)-110 -47px1 32nx1 32ParameterValuehoPreferenceOrderInterfUL/DL (HDL/HUL)INTER / INTRABSCPriority Intra Intra Cell HOHANDOVER PROCESSHandover due to Interference (2/2)Equations 1 and 2 are used if parameter enableHandoverMarginQual is set “Yes” hoThresholdQual = 4hoThresholdInterferenceDL = -85 dBmhoPreferenceOrderInterfDL = intra Trigger for Handover due to InterferenceAB- Field strength higher than threshold- Bad quality= interference= intra cell handover !Threshold (Interference Lev) -85 dBm506 dBUmbrellaHandoverAB-90 dBmHandover dueto LevelMacro cellMicro cellExampleGSM MS class 4 (33 dBm)gsmMacrocellThreshold = 35 dBmgsmMicrocellThreshold = 33 dBmmsTxPwrMax(n) = 33 dBmhoLevUmbrella = -85 dBmhoThresholdLevDL = -90 dBm-85 dBmUmbrellaHandoverHandover dueto LevelHANDOVER PROCESSUmbrella Handover (1/2)lTrigger Periodic Check ( hoPeriodUmbrella )lMulti-Layered NetworkHANDOVER PROCESSUmbrella Handover (2/2)enableUmbrellaHandover (EUM)Y / NhoPeriodUmbrella (HPU)0 63 (SACCH)hoLevelUmbrella (AUCL)-110 -47ParameterValueHANDOVER PROCESSCombined Umbrella & Power BudgetlWhen enablePowerBudgetHo = Yes & enableUmbrellaHo = YesPower Budget Handover to cells of the same layerUmbrella Handover to cells of different layer微宏只有没微宏只有没有有HANDOVER PROCESS Imperative Handover: DistanceDistance Process - msDistanceBehaviour (0,1.60,255) in BSC0 : Release immediately1 - 60 : Release after certain time 1 - 60 s, try handover during that time255: No release, only imperative Handover attemptDistance ProcessenableMsDistanceProcess (EMS)Y / NmsDistanceHoThresholdParam以时间提前量为单位以时间提前量为单位0 63表示表示px (MSR/MSP/MSN)1 32nx1 32ParameterValuemsDistanceBehaviour (DISB)0, 1 60, 255BSC DISB的取值有62种情况，即：060和255。0表示由于TA原因引起的切换一旦失败，立即释放该连接；1表示移动台TA值超过门限后，网络在1秒钟时间内处理处理切换过程，超过该时间后网络将释放该连接；依此类推，60表示移动台TA值超过门限后，网络在60秒钟时间内处理处理切换过程，超过该时间后网络将释放该连 接。255则表示，当移动台的TA超过门限后，网络将启动切换过程，但无论切换是否成功，网络将维持该连接的存在，而不启动强行拆连过程。 当移动台在连接模式时移动出服务小区的覆盖范围时，一般都希望移动台切换到相应的邻区。这种切换不仅是为了保持良好的通信质量，更主要的是为了减小小区间的干扰。GSM的基站设备通过检测移动台的时间提前量（TA）来换算出移动台与基站所处位置间的空间距离，当TA值超过规定的门限时，无论通信质量的优劣，系统将启动越区切换过程。但有时由于某种原因，可能导致切换的失败。为了控制网络中的干扰，当TA值超过门限而切换又不成功时，网络在规定的时间（DISB）内将强拆除该连接。 POWER CONTROLBSSPAR S9POWER CONTROLReasons and StrategyThere can be Power Control (PC) both for MS power and BTS power. Handled by the BSC.手机和基站的功率控制是由控制的手机和基站的功率控制是由控制的REASONSOptimize Uplink and Downlink QOS - decrease interferences降降低干扰低干扰Decrease power consumption of the Mobile Station使手机省电使手机省电POWER CONTROLStrategySTRATEGYEnough margin against Rayleigh fading有足够的余量对付快衰落有足够的余量对付快衰落HO has always higher priority than PC切换优先于功控切换优先于功控Controlled by interval有间隔有间隔Increase and decrease act independently升降功率相对独立升降功率相对独立BTS and MS apply Power Control independently手机与基站的功控相手机与基站的功控相对独立对独立BCCH TRX doesnt use Power Control.载频不做功控载频不做功控DL/UL Power Control can be disabled上下行的功控可以被禁掉上下行的功控可以被禁掉POWER CONTROLOverview (1)Measurements BtsMeasAverageAveragingWindow SizeAdjCellAllAdjacentCellsAveragedNumberOfZeroResultsAveragingAveragingBookkeepingho/pc_Averaging_Lev/Qual_UL/DLWindowSizeWeightmsDistanceAveragingParameterWIndowSizeDTXModeMeasurements Power Control ?EnaFastAveCallSetupEnaFastAvePCEnaFastAveHOMS + BTSMS功控与相邻小区无关POWER CONTROLOverview (2)Uplink LevelUplink QualityAV_RXQUAL_UL_PCAV_RXLEV_UL_PCDownlink LevelDownlink QualityAV_RXQUAL_DL_PCAV_RXLEV_DL_PCPOWER CONTROLUPLINKTHRESHOLD COMPARISONSeparate Averaging Parameters For Handover and for Power ControlPOWER CONTROLDOWNLINKPCINTERVALpowerControlInterval (INT)0 30 sec.powerIncrStepSize (INC)2, 4, 6 dBpowerReductionStepSize (RED)2, 4 dBpowerControlEnabled (PENA)Y / NParameterValuePOWER CONTROLParametersParameterValue pcUpper/LowerThresholdsLevUL rxLevel px nxpcUpper/LowerThresholdsLevDL rxLevel px nxpcUpper/LowerThresholdsQualUL rxQual px nxpcUpper/LowerThresholdsQualDL rxQual px nx-110 . -47 (dBm)1 . 321 . 32-110 . -47 (dBm)1 . 321 . 320 . 7 1 . 321 . 320 . 7 1 . 321 . 32AV_RXQUAL_UL_PCAV_RXLEV_UL_PCAV_RXQUAL_DL_PCAV_RXLEV_DL_PCPOWER CONTROLSafety regionLowerLEVUpperLEVUpperQUALLowerQUALApplicable both on Downlink and Uplink DirectionsPOWER CONTROLRangesbsTxPwrMax 是最大发射功率的衰减值偶数是最大发射功率的衰减值偶数0 30 dB (2 dB step) bsTxPwrMin 0 30 dB (2 dB step) minMsTxPowerfor GSM5 43 dBm (2 dB step) msTxPwrMaxfor GSM是的发射功功率奇数是的发射功功率奇数5 43 dBm (2 dB step) ParameterValue30 dB RangeSystem Dependent RangeAttenuationsPower ValuesPOWER CONTROLif RXLEV_UL+ 2*PowIncrStepSize = PcLowerThresholdsLevULPWR_INCR_STEP = PcLowerThresholdsLevUL- RXLEV_UL(Variable step size)elsePWR_INCR_STEP = PowIncrStepSizeRXLEV_UL is the current signal level measured by the BTS上行接收电平由测量上行接收电平由测量RXLEV_UL AV_RXLEV_UL_PC ( used for threshold comparison )PcLowerThresholdsLevULPower Control TriggeredMS power increase due to signal level手机因电平原因升功率手机因电平原因升功率POWER CONTROLlif RXLEV_UL - 2*PowRedStepSize = PcUpperThresholdsLevULPWR_DECR_STEP = RXLEV_UL - PcUpperThresholdsLevUL(Variable step size)lelsePWR_DECR_STEP = PowRedStepSizeRXLEV_UL is the current signal level measured by the BTSRXLEV_UL AV_RXLEV_UL_PC ( used for threshold comparison )PcUpperThresholdsLevULPower Control TriggeredMS power decrease due to signal level手机因电平原因降功率手机因电平原因降功率POWER CONTROL MS power increase due to signal qualitylOnly variable step sizelTwo different AlgorithmslLargest increase is consideredPWR_INCR_STEP = (1+MAX(0,Qa)*PowIncrStepSizewhere Qa = RXQUAL_UL - PcLowerThresholdsQualULPWR_INCR_STEP = PcLowerThresholdsLevUL - RXLEV_ULBased on Current LevelBased on Current QualityIF : RXLEV_UL + 2*PowIncrStepSize = PcUpperThresholdsLevULPWR_DECR_STEP = RXLEV_UL - PcUpperThresholdsLevUL(Variable step size)elsePWR_DECR_STEP = PowRedStepSizeSame as in the MS Power decrease due to Signal Level, but Triggered by different condition (quality)所降的功率与因电平原因降的功率一样，但其触发原因是不同的POWER CONTROL MS power decrease due to signal quality (1)lPWR_DECR_STEP = MIN PwrDecrLimit, MAX( MAX (0, RXLEV_UL - OptimumRxLevUL), (PwrDecrFactor + MAX(0, Qa) *PowRedStepSize ) lwhere Qa = PcUpperThresholdsQualUL - AV_RXQUAL_UL_PCIF : optimumRxLevUL N打开上行优化电平打开上行优化电平POWER CONTROL MS power decrease due to signal quality (2)PwrDecrLimitBand0 : ifAV_RXQUAL_UL_PC = 0PwrDecrLimit = 10dBPwrDecrLimitBand1 : ifAV_RXQUAL_UL_PC = 1PwrDecrLimitBand2 : ifAV_RXQUAL_UL_PC = 2POWER CONTROLlif RXLEV_DL + 2*PowIncrStepSize = PcLowerThresholdsLevDLPWR_INCR_STEP = PcLowerThresholdsLevDL - RXLEV_DL(Variable step size)lelsePWR_INCR_STEP = PowIncrStepSizeRXLEV_DL is the current signal level measured by the MS 下行电平由手机测量下行电平由手机测量RXLEV_DL AV_RXLEV_DL_PC ( used for threshold comparison )PcLowerThresholdsLevDLPower Control TriggeredBTS power increase due to signal level基站因电平原因升功率基站因电平原因升功率PcUpperThresholdsLevDLPower Control TriggeredPOWER CONTROL BTS power decrease due to signal level (1) (S9 improvement)lVariableDLStepUse = Y/N 下行可变步长是否使用(S9 new feature)lIf VariableDLStepUse = N PWR_DECR_STEP = PowRedStepSize(no variable step size)POWER CONTROL BTS power decrease due to signal level (2)(S9 improvement)lVariableDLStepUse = YPcUpperThresholdsLevDLPower Control Triggeredif RXLEV_DL - 2*PowRedStepSize = PcUpperThresholdsLevDLPWR_DECR_STEP = MIN(RXLEV_DL - PcUpperThresholdsLevDL),10)(Variable step size)elsePWR_DECR_STEP = PowRedStepSizeRXLEV_DL is the current signal level measured by the MS RXLEV_DL AV_RXLEV_DL_PC ( used for threshold comparison )POWER CONTROL BTS power increase due to signal qualitylOnly variable step sizelTwo different AlgorithmslLargest increase is consideredPWR_INCR_STEP = (1+MAX(0,Qa)*PowIncrStepSizewhere Qa = RXQUAL_DL - PcLowerThresholdsQualDLPWR_INCR_STEP = PcLowerThresholdsLevDL - RXLEV_DLBased on Current LevelBased on Current QualityIF : RXLEV_DL + 2*PowIncrStepSize = PcLowerThresholdsLevDLLARGEST INCREASEPOWER CONTROL BTS power decrease due to signal quality(S9 improvement)lVariableDLStepUse =Y/N (S9 new feature)lOptimumRxLevDL = -109-47 dBm/NlIf VariableDLStepUse = N PWR_DECR_STEP = PowRedStepSize(no variable step size)PWR_DECR_STEP = PowRedStepSize(no variable step size)The decrease in power does not take place if there is the possibility that it would trigger the threshold PcLowerThresholdsLevDL (the safety margin is 6dB).POWER CONTROLBTS power decrease due to signal qualitylTwo different AlgorithmsBased on OptimumRxLevDL being used or notlif the resulting RXLEV_DL would get too close to PcLowerThresholdLevDL (as a result of the decrease) there could be a consecutive increase due to level which will lead to triggering the decrease again. To avoid this ping pong effect BSC makes sure before decreasing the power due to signal quality that RXLEV_DL is at least 6 dB higher than the PcLowerThresholdLevDL.6 dB Margin is in-built in BSCPOWER CONTROL BTS power decrease due to signal quality (2)(S9 improvement)lVariableDLStepUse = YlOptimumRxLevDL = lif RXLEV_DL - 2*PowRedStepSize = PcUpperThresholdsLevDLPWR_DECR_STEP = MIN(RXLEV_DL - PcUpperThresholdsLevDL),10)(Variable step size)lelsePWR_DECR_STEP = PowRedStepSizeRXLEV_DL is the current signal level measured by the MS RXLEV_DL AV_RXLEV_DL_PC ( used for threshold comparison )POWER CONTROL BTS power decrease due to signal quality (2)(S9 improvement)lPWR_DECR_STEP = MIN PwrDecrLimit, MAX MAX (0, RXLEV_DL - OptimumRxLevDL), (PwrDecrFactor + MAX(0, Qa) *PowRedStepSize lwhere Qa = PcUpperThresholdsQualDL - AV_RXQUAL_DL_PCIF : optimumRxLevUL NVariableDLStepUse = YOptimumRxLevDL = ( -109-47 dBm)质量等级质量等级0的功率递减限制的功率递减限制原名： power decr limit band 0（PD0）。POWER CONTROLMS Power Optimization in Call Set-uplNormally MS accesses the TCH with the maximum Tx Power allowed in the cellmsTxPwrMaxlWhen power optimization is employedMS_TXPWR_ OPT = MsTxPwrMax - MAX ( 0, (RXLEV_UL - OptimumRxLevUL) )lParameter OptimumRxLevUL must be defined for each TRX in the CellIf different values then maximum is consideredlRXLEV_UL is measured during signalling phase POWER CONTROLMS Power Optimization in HandoverlIntracell HandoverNormally MS uses the maximum Tx Power allowed in the target cellmsTxPwrMaxWhen power optimization is employedMS_TXPWR_ OPT = MsTxPwrMax - MAX( 0, (AV_RXLEV_UL_HO + (MsTxPwrMax - MS_TXPWR) - OptimumRxLevUL)lParameter OptimumRxLevUL must be defined for each TRX in the CellIf different values then maximum is consideredOptimumRxLevUL -109 -47 dBm / N ParameterValueExample: AV_RXLEV_UL_HO= -75 dBm OptimumRxLevUL= -80 dBm MS_TXPWR_OPT = 33 dBm -MAX( 0, -75 dBm+80 dBm)MS_TXPWR_MAX= 33 dBm = 33 dBm -5 dB = 28 dBmMS_TXPWR = 33 dBm POWER CONTROLMS Power Optimization in HandoverlIntra BSC intercell HandoverNormally MS uses the maximum Tx Power allowed in the target cellmsTxPwrMaxWhen power optimization is employedMS_TXPWR_ OPT(n) = MsTxPwrMax(n) - MAX ( 0, (AV_RXLEV_NCELL(n) - MsPwrOptLevel) )lParameter msPwrOptLevel is defined on a per adjacent cell basis 6 dBHandoverServing Cell DLAdjacent Cell DLAdjacent Cell ULmsPwrOptLevelmsPwrOptLevel -110 -47 dBm / N ParameterValueAffects UplinkEither Uplink signal equals downlink signal Or Differences in UL / DL considered when defining msOptPwrLevell1.HO DUE TO INTERFERENCEl2.NOTHING HAPPENl3.MS POWER DOWN DU TO LEVELl4.MS POWER DWON DUE TO QUALITYl5.HO QUE TO QUALITYl6.MS POWER UP DUE TO LEVELl7.MS POWER UP DUE TO LEVELl8.HO DUE TO QUALITYl9.HO DUETO QUALITYl10 HO DUE TO LEVELMEASUREMENTS Contents1. Coding Level and Quality 2. MS Measurements in Idle Mode3. MS Measurements in Dedicated ModeMEASUREMENTSCoding of Level and QualityLEVELQUALITYP (dBm) FS (dBuV/m) LEV-110 27 0-109 28 1-108 29 2 . . . . . . . . .-49 88 61-48 89 62-47 90 63 BER (%) BER (%) QUALRANGE MEAN 12.8 18.1 7 900 MHzP=PowerFS= Field StrengthLEV= LevelBSCBSCMEASUREMENTSMS Measurements in IDLE Mode(GSM Specs)MS has to decode BCCH of serving (camped)cell every 30 sMS has to decode BCCH of adjacent cells at least every 5 minPre-synchronization and BSIC-decoding of neighboursOnce in 30 sList of 6 best neighbours is updated every 60 s New neighbour BCCH decoding in 30 sMEASUREMENTSMS Measurements in DEDICATED Mode (1) Measures the Lev and Qual of the Server Detects whether DTX is used 26-FRAME MULTIFRAME 120 msTDMA FRAMES:TCHSACCHIDLE Measures the BA frequencies (System Info 5) BSIC decoding of at least one neighbour Pre-Synchronization on SCHTDMA FRAME 4.615 msSACCH PERIOD = 480 msRXTXRXTXRXTXMEASMEASMEASMEASUREMENTS MS Measurements in DEDICATED Mode (2)(GSM specs)Pre-synchronization and BSIC-decoding of adjacent cellsOnce in 10 sNew neighbour5 s decoding BSIC + Pre-synchronizationIf not succesfull - Old neighbour list + New tryMeasurement results of 6 best neighbours will be sent to BSCEvery SACCH period 480 msec.MEASUREMENT PROCESSINGContents1. Pre-Processing in BTS 2. Averaging and Sampling3. DTX and Weighting4. Processing in BSC5. Bookkeeping6. Parameters related to Measurements and Measurement Processing btsMeasAver 1 . 4 (SACCH Period)Parameter ValueMEASUREMENT PROCESSINGPre-processing in BTSlFor MS and BTS measurementslAverage measurements over 1, 2, 3 or 4 SACCH-periodlCause a delay (btsMeasAver-1) x 480 ms（缓存时间）lReduce a transmission load and a processing load in BSCBTS和MS必须对处于激活状态的无线信道进行测量（包括接收电平和接收质量的测量）。MS需将测量结果以测量报告的形式通过SACCH报告给BTS。BTS则需对由BTS测量的上行结果和由MS测量的下行结果进行平均统计，以此为功率控制和越区切换的依据。对测量结果进行平均处理所用的周期，BMA取值范围为14，以SACCH复帧周期为单位。1表示BTS对一个SACCH复帧周期的测量结果进行平均；2表示BTS对二个SACCH复帧周期的测量结果进行平均；由于无线信道存在有各种衰落的影响，因此测量平均的周期越长，实际的结果越准确。但测量平均的时间越长，处理功率控制和切换的时间也越长，从而使系统的控制性能下降。 (BMA)MEASUREMENT PROCESSINGAveraging and SamplingHoThresholdLevDL = 33 (= -77 dBm) WindowSize = 5, Weighting = 1Px = 3, Nx = 4btsMeasAver = 1 (no pre-processing in BTS)302550354540152010 480 msAVERAGE=40, P=0AVERAGE=35, P=0AVERAGE=30, P=1AVERAGE=25, P=2AVERAGE=20, P=3Handover attempt ho/pc_Averaging_Lev/Qual_UL/DLWindowSize1 32Weight.1 3msDistanceAveragingParameterWIndowSize.1 32ParameterValueMEASUREMENT PROCESSINGFast AveragingAveraging window size full (size = 4)232726 24 27 2427/1(27+23)/2(27+23+26+24)/4(27+23+26)/3when the averaging window is full, a normal sliding window technique is used as in the example:(23+26+24+27)/4(26+24+27+24)/4NOKIA TELECOMMUNICATIONSlAveraging started with available sampleslLevel measurements scaled after a PC commandSeparately on UL and DLEnaFastAveCallSetup (EFA)Y / NEnaFastAvePC (EFP)Y / N EnaFastAveHO (EFH)Y / NParameterValueAV_RXLEV_UL_PC = 2x35 + 1x42 + . + 2x35 2+1+2+2+1+1+1+2= 36MEASUREMENT PROCESSINGDTX and WeightinglDTX is allowed just on TCH lDTX is used only for speech calls.l“SUB”- measurement results are reported when DTX is usedSample:12345678DTX used:01001110uplink level: 35 42 33 36 39 40 39 35ExamplepcAveragingLevUL windowSize = 8 weighting = 2DTXMode0MS may use DTX1 MS shall use DTX2MS shall not use DTXParameterValueMEASUREMENT PROCESSING BSC Measurement Data Processing MS DATA (MEASURED BY BTS)0 1 0 03 2 20 0 131 0 1 0540 05 4 4 4 4 5 6565454500 0 04851452434744410036322 1 0 3 0 4 51 1 1 05 6 7 6333028325 1 0 00 0 0 0 1 1 1 0 0 0 0 0 0545452520 1 04648400424444450040351 2 2 3 5 6 40 0 0 0333435364 3 2 2494846454342404039380 253032324038424443485060585654563335384042444851535456LEV_NCELL(n)AV_RXLEV_NCELL(n) BTS DATA (MEASURED BY MS) ABTS DATA (MEASURED BY MS)DTX USEDQUAL_DLRXLEV_DLAV_RXLEV_DL_HODTX USEDQUAL_ULRXLEV_ULTIMING ADVANCEEXAMPLES:1. HO AVERAGING AND COMPARISONWindow Size = 8, Weighting = 2HoThresholdLevDL = 38 (-72 dBm), Px = 1 Nx = 12. ABTS AVERIGING AND PBGT COMPARISONWindowSizeAdjaCell = 7hoPeriodPBGT = 8 SACCH (= 4 s)hoMarginPBGT = 6 dB