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06/06/22 07:52 AM Optimazaion 1 BSS OPTIMIZATION BSS OPTIMIZATION By V.V.S.S.RAMAKRISHNA, SDE, NORTEL MSC, VJA
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Page 1: Bss Optimization

04/07/23 10:17 PMOptimazaion1

BSS OPTIMIZATIONBSS OPTIMIZATION

By

V.V.S.S.RAMAKRISHNA,

SDE, NORTEL MSC, VJA

Page 2: Bss Optimization

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What to Optimize ?What to Optimize ?

QOSCAPACITYOPERATIONAL COSTS

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QOSQOS

CoverageCall SetupVoice QualityCall Drop

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MeasurementsMeasurements

Air Interface MeasurementsAbis Interface MeasurementsA interface MeasurementsNSS & BSS counters

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MeasurementsMeasurements

Air Interface and Abis Interface Measurement reports can be had from OMCR

A interface measurements can be had from MSC

NSS & BSS parameter tuning to be done as per QOS requirement

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OMCR ReportsOMCR Reports

QOS =

100 – ( 50 x callDropTrafficRatio +

10 x signallingReleaseRatio + 10 x cellSdcchResourceFailureRatio + 10 x cellTchResourceFailureRatio + 20 x hoInTchExecutionFailRate)

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OMCR ReportsOMCR Reports

callDropTrafficRatio=trafficAbnormalRelease (1779)

------------------------------------------------------------------------------------------------------------( successfulTchFrSeizures(1050) – hoSuccessIntraBts(1083) + hoSuccessIncomingIntraBss(1073) + hoSuccessIncomingInterBss(1074))

signallingReleaseRatio =

(signallingAbnormalReleaseCell(1778) - signallingReleaseBtsT3107CircDown(1163/6)-----------------------------------------------------------------------------------------------------------------------

estabIndicSigPhase1(1195) + estabIndicSigPhase2(1196)

cellSdcchResourceFailureRatio=

sdcchRessourceFailure(1608)---------------------------------------------------------------------------------------------------------------- ---------------------------------

sdcchAllocated(1606) + sdcchRessourceFailure(1608) +tchFrAllocatedOverflowAllocation(1609/2)

cellTchResourceFailureRatio

tchFrRessourceFailure (1613) + signallingReleaseBtsT11 (1163/30) ---------------------------------------------------------------------------------------------------------------------------------------

tchFrRessourceFailure (1613) + signallingReleaseBtsT11 (1163/30) + tchFrAllocatedPrimoAllocation(1609/1) + tchFrAllocatedOverflowAllocation (1609/2)

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OMCR ReportsOMCR Reports

hoInTchExecutionFailRatio=(hoSuccessIncomingIntraBss(1073) + hoSuccessIncomingInterBss(1074))

---------------------------------------------------------------------------------------(hoExecutionIncomingIntraBss(1071) + hoExecutionIncomingInterBss(1072))

8623 Average downlink RxLev in dBm

averageDLRxLev = {rxLevDownlink

-110 + ----------------------------------------------------(connectionDurationTchCum / 480 + connectionDurationSdcchCum / 470 - msLostMeasurements)}

8624 Average uplink RxLev in dBmaverageULRxLev=

(rxLevUplink /-110 + ----------------------------------------------------------------------

{ (connectionDurationTchCum / 480)+(connectionDurationSdcchCum / 470)}

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OMCR ReportsOMCR Reports

8626 Average downlink RxQual in BER

averageDLRxQual ={ rxQualDownlink

----------------------------------------------------(connectionDurationTchCum/480 +connectionDurationSdcchCum/470 - msLostMeasurements) /100

}

8624 Average uplink RxQual in BER

averageULRxQual=(rxQualUplink /

---------------------------------------------------------------- { (connectionDurationTchCum / 480)+

(connectionDurationSdcchCum / 470)}/100

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OMCR ReportsOMCR Reports8726 Number of decoded ramdom accesses received by

the BTS from the MS for all the cellsrachBusyCountCell =

rachBusyCount + rachBusyCount2 + rachBusyCount4 + rachBusyCount6

8727 Number of random accesses transmitted to the BSC for all the cells

rachAccessCountCell =rachAccessCount + rachAccessCountTs2 +

rachAccessCountTs4 + rachAccessCountTs68733 Average level on non decoded RACHs for all the cellsrachNonDecodedAvLevelCell =

rachNonDecodedAvLevelMax + rachNonDecodedAvLevelTs2Max+ rachNonDecodedAvLevelTs4Max +rachNonDecodedAvLevelTs6Max

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OMCR ReportsOMCR Reports

8704 Ratio of the immediately served paging requests

pchNoWaitRatio =

pchNoWait(1028)----------------------------------------------------------{pchNoWait(1028) + pchOneWait(1029)+ pchTwoWait(1030) + pchMoreWait(1031) + pchQueuePagesDiscarded(1605) }

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OMCR ReportsOMCR Reports1619/0 Average number of free channels

in interference band No.0

channelAveragedIdlePerInterfBand0MoychannelAveragedIdlePerInterfBand0MaxchannelAveragedIdlePerInterfBand0CumchannelAveragedIdlePerInterfBand0Ech

Similarly for band No.1,2,3,4

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CCCH GroupCCCH Group

The Common Control Channel Group is bi-directional ie, it works in both uplink and downlink directions.

Random Access Channel (RACH) is for “uplink” used by MSs to gain access to the system.

Paging Channel (PCH) and Access Granted Channel (AGCH) operate in the “downlink” direction. The AGCH is used to assign resources to the MS, usually a Standalone Dedicated Control Channel (SDCCH), although a TCH can be assigned in this way. The PCH is used by the system to page a MS. The PCH and AGCH are never used at the same time.

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BCCH GroupBCCH Group The Broadcast Control Channels (BCCH) are

downlink only (BSS to MS) and comprise the following:

BCCH system information broadcasts allow the MS to correctly camp onto a cell’s transmission. These messages also contain information concerning idle neighbors.

The Synchronisation Channel (SCH) carries information for frame synchronization and includes the BSIC.

The Frequency Control Channel (FCCH) provides information for carrier synchronisation.

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DCCH GroupDCCH Group

Dedicated Control Channels (DCCH) are assigned to a single MS to allow point to point signalling transactions.

Standalone Dedicated Control Channel (SDCCH) which supports the transfer of Data to and from the MS during call setup, location updating and Short Message Service (SMS).

Associated Control Channel (ACCH). This consists of slow ACCH which is used for system information, radio link measurements and power control messages.

Fast ACCH is used to pass “event” type messages e.g. handover and disconnect commands. Both FACCH and SACCH operate in uplink and downlink directions.

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PLMN selectionPLMN selection

MS after switch on verify the PLMN list stored in SIM and hooks on to the frequency of PLMN selected. If not stored on SIM it scans all the frequencies in the band and measures levels (5 measurements in 3 sec) of 30 best and selects PLMN list as per BCCH (beacon frequency FCCH & SCH). BCC and NCC of BSIC will be used for selection of SCH (synchronization Channel)

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Initial cell selectionInitial cell selection

An MS must initially select a specific cell to be able to be reached, to make a call and listen to system information. The process is based on

Radio attenuation (criterion C1)Selection priority ( barred, normal or low

priority)

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Radio Attenuation (C1 Criteria)Radio Attenuation (C1 Criteria)

MS calculate C1 for all available cells (after PLMN selection) and decode their selection priority. The MS camps on to the cell which has maximum C1.

C1 = A – BA = (RXLEV – rxLevAccessMin)B = MAX[(msTxPwrMaxCCH – P),0]

P is the maximum power of mobile as per power class spec (class2-39dbm/8w; class2-37dbm/5w ; class4-33dbm/2w; class5 – 29/0.8w)

rxLevAccessMin(-100dbm) is minimum receive level of MS to access system and msTxPwrMaxCCH(33dbm) is Maximum output power of MS (received in BCCH.).

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Selection prioritySelection priority

is based on cellbarqualify(false), cellreselind(true) and cellbarred (false) for phase1 mobiles. Phase2 mobiles use cellbarred if cellbarqualify is false else uses cellreselind to select cell.

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Cell reselection criteriaCell reselection criteria

C2 (every 5 sec) = C1 + cellreselctoffset(4dbm) – temporaryoffset(dbm). The cell is selected for which C2 is more based on T, the timer started upon selection of best neighbor and if T < penalty Time (20s) temporaryoffset is used other wise not used. If cellreselind is false, C2=C1.

cellReselectHysteresis (6db) is used to reduce LU & paging messages and ping-pong effect. If C1(new) > C1(old)- cellReselectHysteresis then new cell is selected.(same applied for C2 also).

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RACCH control parametersRACCH control parameters MaxNumberRetransmission (2) is to transmit

access requests if system does not respond for 1st request. Retransmission is 2 times only. The time between two successive transmissions is controlled by numberOfSotsSpreadTrns(32TS)

Time RACH = Time RACH + 4.615x[(S+1) +N] ms

RACH access denied if Timing advance calculated by BTS and reported to BSC is greater than a Threshold value mdAccTimingAdvThreshold in BSC and BTS (set as 35Km-value 63).

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Paging Channel (PCH)Paging Channel (PCH)

noOfBlocksForAccessGrant(2) (Total CCH blocks 9 in 51 Frame Multiframe) noOfMultiframesBetweenPaging(2) This gives AGCH channels which is mandatory to give ack to RACH request immediately on SAME TS (DL)

PCH and AGCH loads can be altered by defining parameters nbOfRepeat(3), delayBetweenRetrns(0) and retransDuration(10) (Retransduration >= nbofrepeat (delaybetweenretraans+1)

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Radio measurementsRadio measurements MS calculates RXLev, RXQual, Rxlevel of 6

best Neighboring cells (+BSIC) and evaluates MS_TXPWR_CONF(present U/L pwr) and reports to BTS.

BTS measures RXlev, RXQual UL, and evaluates TA, Current BTS TX power and decodes MS_TXPWR_CONF.

For dual band sites reporting is done based on parameter multibandReporting (6 strong/strong out band/2 strong outband/3strong outband)

Reporting is done on SACCH using LAPDm protocol. 1 SACCH message contains 4 TS {Since LAPDm is 23bytes(184 bits) and after encoding it is 456bits(8X57bits) hence each TS (2x57bits)-> 4TS} for every 2x 235=470ms one report is sent if used on SDCH

If used on TCH (13th frame in 26 frame duration is 120ms) 4x 120=480ms one report

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Radio measurementsRadio measurements RXlev reported By MS in 6 bit format as values

from 0 to 63 for measured levels from -110 dbm to -47 dbm. AT BTS end RXlev= received level[0 to 63] -110. The higher the value best signal.

RXqual is reported by 0 to 7 for BER 0.14,0.28,0.57,1.13,2.26,4.53,9.05,18.1). The more the value worst cell (these are stored in 100BER)

The parameter powerControllIndicator (include BCCH/not include) states reports include measurements on BCCH frequencies or not

dtxMode [shallnotuse] for MS and sent in SYS INFO messages and for BTS cellDtxDownlink [disabled] if used SUB level measurements taken otherwise FULL measurements taken.

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Radio measurementsRadio measurements RXlev, RXQual used for power control /

handover decision. MS-BS distance used for handover/call clearing

decision using three parameters runpowercontrol (4), runhanover(1), runcallclear(16) (value indicates no of measurements to be received).

These along with rxXXHreqave(no of samples for average), rxXXhreqt(no of averages for weighted average), rxXXwtslist (list of weights), missrxXXwt(missing measurements) parameters used for averaging and taking decision which to run among the three above.

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Power ControlPower Control Runpowercontrol is used to take decision for

reducing power level of MS based on the parameters msTxPwrMax(33dbm), msTxPwrMaxCell(n), msTxPwrMax2ndBand, msTxPwrMaxCCH(maximum allowed in CCH), uplinkpowercontrol and for BTS bsTxPwrMax(43dbm), bsPowerControl(enabled), (l/u)RxLevDLP, (l/u)RxLevULP, (l/u)RxQualULP, (l/u)RxQualDLP, newpowercontroll alogorithm (stepbystep), power(Incr/red)StepSize(+4db).

lRxQualDLP >=uRxQualDLP and lRxQualULP >= uRxQuaDLPl

Attenuation for BTS is limited to 8dB and for MS it is able to attenuate at least 16db per SACCH measurement period (2dB/60ms is GSM recommendation)

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Handover controlHandover control Triggering: The BTS detects that a handover is

needed based on threshold parameters. Screening: The BTS determines what are the 6

best suitable target cells for HO and send HO indication to BSC

Selecting: BSC determines target cell and sends HO command.

Executing: Allocation, activation, assignment of new channel, switching to new channel

Different types of handovers: Intra Cell (within same cell due to quality) Inter Cell (intra BTS) Inter Cell (intra BSC) Inter Cell (inter BSC, Intra MSC) Inter Cell (Inter MSC)

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Handover controlHandover control Handovers can be decided based on Permanent

criteria i.e., Rxlev, Rxqual through configurable thresholds and configurable criteria based on OMC parameters

Intracell [disabled] msBtsDistanceInterCell [enabled] powerBudgetInterCell [enabled] intraBscDirectedRetry,interBscDirectedRetry at

BSC level and intraBscDirected RetryFromCell ,interBscDirectedRetryFromCell at BTS level all are set at notallowed.

intraCellSdcch [False] HO in SDCCH Hotraffic [enabled]

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Handover controlHandover control Handovers may be Synchronized, non-

synchronized and pre-synchronized. If synchronized MS updates TA from old value ; if non-sychronized MS waits for TA value to receive from BTS. The parameter is set at BTS are synchronized {BTS,microcellular TA=1,normal, preSynchroTimingAdvance}

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The priority order of HOThe priority order of HO Directed Retry Capture RxQual (Ul then Dl) Rxlev (Ul then Dl) Distance Power Budget Traffic intra-cell (Ul then Dl) InterZone Automatic Cell Tiering

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Directed Retry HandoverDirected Retry Handover

When a call is set up on SDCCH and no TCH is available, BSC checks for free TCH in suitable neighboring cell if intraBscDirectedRetry, interBscDirectedRetry at BSC level and intraBscDirectedRetryFromCell, interBscDirectedRetryFromCell at BTS level all are set at allowed. directedRetryModeUsed[bts,bsc] is used for type of directed retry.

If set to BTS, list of eligible cells is sent by BTS by seeing the threshold parameter directedRetry[>48dBm](=rxlevmincell+3db).

If set to BSC, BSC chooses predefined target cell set by the parameter adjacentCellUmbrellaRef.

The parameter modeModifyMandatory[used] will send the CHANNEL MODE MODIFY command to BTS to switch from Signal to Speech after HO.

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Capture HandoverCapture Handover

This handover is only from Macrocell to Microcell.

Microcell to Macrocell is normal HO based on other factors.

microCellCaptureTimer, microCellStability defines handover can be done or not. The strength criteria is verified on at least one neighboring micro cell to check for possibility using

RXLEV_NCELL(n)-rxLevMinCell(n) >0 allowed and then the following is checked for neighbor cells

RLEV_NCELL_MAX(n) – RXLEV_NCELL_MIN(n) < microCellStability(n)(10dB) during the microCellCaptureTimer(n) (multiple of runHandover=0)

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Quality HandoverQuality Handover

Handover on quality is performed if RXQUAL_UL>lRxQualULH(1.6 to3.2) or RXQUAL_DL>lRxQualDLH(1.6to3.2)

The missing measurements are replaced by latest average weighted by missRxQualWt(110).

rxQualHreqave = no of samples in an arithmetic average ;

rxQualHreqt = number of averages in the weighted average;

rxQualWtsList= List of Weights in the Weighted average.

If no average is found default value is 3

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LEVEL HandoverLEVEL Handover

Handover on level is performed if RXLEV_UL<lRxLevULH(-100dB) or RXLEV_DL < lRxLevDLH(-100dB). RXLEV_NCELL(n) – [rxLevMinCell(n) +

MAX(0,msTxPwrMaxCell(n)-P(n)) > 0 for normal HO on level

The missing measurements are replaced by latest average weighted by missRxLevWt(90).

rxLevHreqave =no of samples in an arithmetic average; rxLevHreqt=number of averages in the weighted average ;rxLevWtsList=List of Weights in the Weighted average.

If no average is found default value is 32. The receiver sensitivity of BTS is (-104,-107,-

109,-109.5,-110 for S2L,S4k,S2h,S2h,S8) and for MS (-104,-102,-100 for 8w,2w,1w)

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Distance HandoverDistance Handover

If MS_BS_Distance > msRangeMax HO on distance is performed

MS-BS Distance = TA_TO_M * Timing advance TA (1 unit of TA=1 Bit period (48/13 micro sec)

TA_TO_M = T*v/(2*BP) where T=577 microSec (1TS duration); v=velocity of light; BP bit period in one timeslot=156.25

msBtsDistanceInterCell[enabled] parameter to enable distance based handovers on BTS

distHreqt, distWtsList, missDistWt, msRangeMax (max distance before handover)

Clears call if callclearing>msrangeMax if previous HO on

distance is failed.

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Power Budget HandoverPower Budget Handover powerBudgetInterCell[enabled] sets whether PBGT is

activated or not. PBGT estimation includes RF power of the mobile, power allowed by system, and depends on minimum received power and the received field strength

PBGT(n) = RXLEV_NCELL(n) – MIN(msTxPwrMaxCell(n),P(n)) - [RxLev_DL(Pm) - Min[mxTxPwrMax,P] > 0

PBGT(n)-hoMarginXX(n) > 0 is used for decission To prevent ping pong HO (coming back to same site) on

power budget, we have another 2 formulae RXLEV_DL (Pmax) < rxlevDLPBGT(n) where

RXLEV_DL(Pmax) = RXLEV_DL + BTS attenuation and rxlevDLPBGT(n) is the maximum possible corrected received level from the current serving cell set at >-48 dBm(63) and should be set as per requirement

RXLEV_NCELL(n) – [rxLevMinCell(n) + MAX(0,msTxPwrMaxCell(n)-P(n)) > 0

For early HO decision, PBGT(n) > homargin(n)+hoMarginBeg(n) [-63 disable this feature]

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Intra-Cell HandoverIntra-Cell Handover It is from one channel in the serving cell to

another channel in the same cell due to poor quality but good signal strength.

Preferred list of cells is not sent in this case. This Ho is performed based on rxLevXXlH (-85

to -834dB), rxQualXXlH (1.6% to 3.2%). The HO is triggered towards less interfered

channels. To favor intracell HO against intercell ho on quality the parameter rxQualXXlH < lrxQualXXH.

If concentric cell/ dualband /dual coupling is used based on the parameter concentricCell[monozone], other parameters for intra-cell HO used are concentAlog(Int/Ext)RxLev[<-110dbm], concentAlog(Int/Ext)MsRange[1km], bizonePowerOffset(n).

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Inter-Cell HandoverInter-Cell Handover The list of neighbor cells is given in

adjacentcellid for the cell object. MS scans 6 best cells and reports to BTS. BTS compares the list with the above parameter and discards the reports if not in list.

The power budget (PBG(n)) is calculated to determine the preferred cells list except for Capture, Directed Retry and Forced HO. Based on the HO cause

EXP(2)=PBGT(n)-hoMarginXX(n) is calculated and list is ordered and decision is taken.

homarginRxQual(n), homarginRxLev(n), homarginDist(n), hoMarginBeg(n).

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Traffic HandoverTraffic Handover This handover is to direct one MS from overload

cell to non-over loaded. The overload criteria is based on number of free TCH in cell <=

numberOfTCHFreeBeforeCongestion or Number of Queued TCH >=

numberOfTCHQueuedBeforeCongestion Mobiles close to the boundary will run a PBGT

Ho procedure PBGT(n)-(homargin(n)-homarginTrafficOffset(n)

Hotraffic [enabled] on BSC level and BTS level decides whether to allow HO on traffic or not

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Automatic Cell tieringAutomatic Cell tiering HO HO If intracell is set as cellTieringHandover, this HO takes place from

non-hopping to hoping. If a MS1 is close to BTS with non-hopping TCH (hence no power

control) and MS2 is far from BTS with hopping (hence with power control).

BTS to MS full power is emitted and may result in interference and hence MS1 is moved to Hopping channel and MS2 is moved to non-hopping channel.

The channel allocation is done based on PWCI( Potential Worst C/I) if PWCI > upper interference threshold, to TCH TRX, if not to BCCH DRX.

The criteria for this HO is based on RXLev on UL. PWCI is ratio between signal received from current cell to the sum of levels from neighboring cells weighted by a factor (18db for adjacent channel) depending on parameter interfererType [NotApplicable /adjacent / coChannel], pwciHreqave [8], numberOfPwciSamples[20], selfTuninObs. total 8 averages values are taken with sample size as 20*1000=20000 samples. First it takes ½ of samples and measures PWCI, again takes remaining samples and computes PWCI on A+B samples, and so on. homarginTiering(4dB) is added to lPwCiDLH to get uPwCiDLH.

If PWCI < lPwCiDLH to non hopping TDM belonging to BCCH and if PWCI > uPwCiDLH to hopping belonging to TCH.

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Other HO parametersOther HO parameters To check for interference levels 5 bands were defined

thresholdInterference and radChanSelIntThreshold radChanSelIntThreshold is Maximum interference level

on free radio channels, below which are arranged in groups of priority allocation.(2)

thresholdInterference is List of four thresholds defined in ascending order, used to sort idle channels on the basis of measured interference levels (-100,-90,-80-,70)

For each idle radio channel, the BTS permanently measures the signal strength level RXLEV. When averagingPeriod “Measurement results” messages have been received, the L1M function in the BTS calculates interference level averages, sorts the idle channels according to the five defined interference levels (Level 0 corresponds to the lowest interference level), and sends the information to the BSC.

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Other HO parametersOther HO parameters HOSecondBestCellConfiguration[2] gives to go for second

attempt in case of HO failure when MS returns to old channel. Each time a HO is done, rank is indicated and this is checked with the above parameter. If < , second HO is performed.

bssMapTchocke [4 sec] is timer started when end of eligible list is reached or all Handover attempts are failed. Next HO indication is ignored till the elapse of this timer.

To avoid ping pong HOs: At BSC level timeBetweenHoConfiguration[used] and at BTS level btstimeBetweenHoConfiguration[1] and at Neighboring cell level hoPingPongCombination [upto 4 causes] to forbid Handover indications and hoPingpongTimeRejection gives the rejection duration for above combinations.

capacityTimeRejection [15to30sec] defines the rejection time of a capacity intra-cell handover after an intra-cell handover

qualityTimeRejection[0 to10sec] defines the rejection time of a quality intra-cell handover after an intra-cell handover . Number of quality intra-cell handover filtered and Number of capacity intra-cell handover filtered are given by minTimequalityintracellHo

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AMR principles and HOAMR principles and HO AMR FR and AMR HR codecs used are

(10.2,6.7,5.9,4.75) and (6.7,5.9,4.75) respectively. Initial codec used is 5.9 for FR /HR. The mode change between two modes is 40ms. UL mode is decided by BTS and DL mode is suggested by MS.

amrAdaptationSet on BSC gives threshold tables to be used and new channel RATSCCH (Robust AMR Traffic Synchronization Control Channel) takes 1 TS for FR and 2 TS for HR. Initial mode is always at 5.9Kbps HR codec. TCH allocation is triggered after receiption of an Assignment request or a handover request. The BSC should decide whether to use AMR and select between HR/FR. This depends on BSC/TCU/BTS/MS capabilities, BSS version and radio context. To select different modes we have

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AMR principles and HOAMR principles and HO speechMode [AMRHR,AMR,FR,FR,EFT] on

Signallingpoint object coderPoolConfiguration [AMR,FR,EFT] on TCU

object and speechMode on BTS object. HRCellLoadStart is 0 only FR is allocated other wise

HR is allocated depending on radio conditions at first TCH allocation only.

The criteria for selection for FR 10.2K if C/I [+∞, 7dB]; 6.7K if C/I [8dB,5dB] ; 5.90K if C/I [6dB,3dB]; 4.75K if C/I [4dB,-∞];

For HR 6.7K if C/I [+∞,15dB] ; 5.90K if C/I [16dB,10dB]; 4.75K if C/I [11dB,-∞].

To select HR/FR BSC checks for radio conditions and gets the information from BTS through “CONNECTION STATE REQUEST” ACK message. Depending the priorities set by parameter FRAMRPriority[0-2], HRAMRPriority[0-2] highest-0;low=1;2 AMR not used.

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AMR principles and HOAMR principles and HO According to the priority radio BSC chooses

radio TS using the following order Interference level TDMA priority TDMA number from the smallest to biggest TS number form biggest to the smallest. In case of HR request, BSC always fills the hole

in terms of free half TS, if no hole /2 hole above priority is used.

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AMR principles and HOAMR principles and HO For inter-BSC handover: According to speechMode parameter of the

target cell the cell load of the target cell the current channel element the cause element The BSC select the target channel type if 3,4

elements are not sent in HO REQ message, FR, if present and HR is allowed in the target, as per table based on the casue(for better cell, traffic HR) other wise FR channel

In case of Intra-BSC HO, PBGT,Traffic, and forced HO, HR is selected. Otherwise FR.

In case of Intra-cell HO major is HR except from small to large zone and HRtoFR ho.

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AMR principles and HOAMR principles and HO Power control: for AMR, hrPowerControlTargetMode

(7.4,6.7,5.9,4.75), frPowerControlTragetMode (12.2,10.2,6.7,5.9,4.75).

The attenuation is limited to RxLevULweight > lRxLevULP and RXLevDLweight lRxLevDLP. powerRedStepsize(UL/DL), powerincStepSize(UL/DL)

Alarm inter-cell HO; Intra-cell HO for FR AMR calls, FR to HR capacity HO, HR to FR alarm HO all these based on nHRRequestedCodec, pRequestedCodec, nFRRequestedCodec if the last p requested codes modes atleast n are smaller than target codec then HO is fulfilled. If n>p feature is deactivated.

Alarm inter-cell HO: the parameters AMRHRIntercellCodeModeThreshold, AMRFRIntercellCodecModeThreshold, hoMarginAMR this HO is not based on Lev/Qual

IntraCellHO:AMRFRIntracellCodecModeThreshold, AMRiRxLevDLH; AMRiRxLevDLH

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AMR principles and HOAMR principles and HO Capacity HO: FR to HR

ncapacityFRRequestedCodec for trade off between quality and capacity. If this is >pRequestedCodec the feature is deactivated. The target is fixed at 12.2 HR. (both directions)

Quality HO: HR to FR AMRHRToFRIntracellCodecModeThreshold[4.75] feature is deactivated. (one direction).

Direct HR TCH allocation: if Receive level UL/DL is > AMRDirectAllocRxlevDL (AMRDirectAllocRxLevUL

If RXLEV_DL > AMRDirectAllocIntRxLevDL & RXLEV_UL > AMRDirectAllocIntRxlevUL for interzone HO, Large to Small Zone Ho, Call establishment.

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AMR principles and HOAMR principles and HO AMR HO priority: HO Capture, AMR quality or

RXQual, RXLev, Distance, PBGT, Traffic, Inter-mode, intra-cell, interzone(DL), automatic cell tiering depending on amrReserved2 value.

0=AMR HO based on CMR/CMC (algorithm on CMR/CMC)

1=based on RxQual (algorithm on CMR/CMC) 2=based on CMR/CMC (algorithm on RXQual) 3=based on RXqual (algorithm on Rxqual)