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  <xsd:element abstract="true" id="sncr_DeferredTaxAssetsMember" name="DeferredTaxAssetsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_DeferredTaxLiabilitiesInstallmentSales" name="DeferredTaxLiabilitiesInstallmentSales" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="sncr_DeferredTaxLiabilitiesPropertyPlantandEquipmentandIntangibleAssets" name="DeferredTaxLiabilitiesPropertyPlantandEquipmentandIntangibleAssets" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="sncr_DescriptionofBusinessAbstract" name="DescriptionofBusinessAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_DiscontinuedOperationIncomeLossfromDiscontinuedOperationbeforeIncomeTaxandGainLossonDisposalofDiscontinuedOperations" name="DiscontinuedOperationIncomeLossfromDiscontinuedOperationbeforeIncomeTaxandGainLossonDisposalofDiscontinuedOperations" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="sncr_DiscontinuedOperationMajorityOwnershipInterestafterDisposal" name="DiscontinuedOperationMajorityOwnershipInterestafterDisposal" nillable="true" substitutionGroup="xbrli:item" type="xbrli:pureItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_DisposalGroupIncludingDiscontinuedOperationPeriodofTransitionServicesAgreement" name="DisposalGroupIncludingDiscontinuedOperationPeriodofTransitionServicesAgreement" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_DivestitureofSpeechCycleMember" name="DivestitureofSpeechCycleMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_DocumentAndEntityInformationAbstract" name="DocumentAndEntityInformationAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_EffectiveIncomeTaxRateBusinessAcquisitionContingentConsiderationFairMarketValueAdjustments" name="EffectiveIncomeTaxRateBusinessAcquisitionContingentConsiderationFairMarketValueAdjustments" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_EffectiveIncomeTaxRateReconciliationCustomerRelationshipAdjustmentsPercent" name="EffectiveIncomeTaxRateReconciliationCustomerRelationshipAdjustmentsPercent" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_EmployeeAndDirectorsStockOptionsMember" name="EmployeeAndDirectorsStockOptionsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_EmployeeStockPurchasePlanPayrollWithholdingPeriod" name="EmployeeStockPurchasePlanPayrollWithholdingPeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_EquityIncentivePlan2015Member" name="EquityIncentivePlan2015Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_EquityMethodInvestmentPeriodofReportingLag" name="EquityMethodInvestmentPeriodofReportingLag" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_ExcessTaxBenefitsMember" name="ExcessTaxBenefitsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_FairValueAssetsTransfersBetweenLevels12And3Amount" name="FairValueAssetsTransfersBetweenLevels12And3Amount" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="sncr_FirstSucceedingFiveYearPeriodMember" name="FirstSucceedingFiveYearPeriodMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_GoldmanSachsBankUSAMember" name="GoldmanSachsBankUSAMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_IncomeTaxAssumptionsHistoricalLookbackPeriod" name="IncomeTaxAssumptionsHistoricalLookbackPeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_IndefiniteMember" name="IndefiniteMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_JointVentureSNCRLLCMember" name="JointVentureSNCRLLCMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_JointVentureZentryLLCMember" name="JointVentureZentryLLCMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_LegalMattersDisclosureAbstract" name="LegalMattersDisclosureAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_LineOfCreditFacilityRightToIncreaseMaximumBorrowingCapacityAmount" name="LineOfCreditFacilityRightToIncreaseMaximumBorrowingCapacityAmount" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="sncr_LineofCreditFacilityAmortizationPercentPerYear" name="LineofCreditFacilityAmortizationPercentPerYear" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="sncr_LineofCreditFacilityMandatoryPrepaymentCovenantOne" name="LineofCreditFacilityMandatoryPrepaymentCovenantOne" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="sncr_LineofCreditFacilityMandatoryPrepaymentCovenantTwo" name="LineofCreditFacilityMandatoryPrepaymentCovenantTwo" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="sncr_MarketableSecuritiesFixedIncomeInvestmentsMaturityPeriod" name="MarketableSecuritiesFixedIncomeInvestmentsMaturityPeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_MarketableSecuritiesMaturityPeriod" name="MarketableSecuritiesMaturityPeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_MirapointActivationBusinessDivestitureMember" name="MirapointActivationBusinessDivestitureMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_MiyowaSAMember" name="MiyowaSAMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_NetIncomeLossfromContinuingOperationsAvailabletoCommonShareholdersDiluted" name="NetIncomeLossfromContinuingOperationsAvailabletoCommonShareholdersDiluted" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="sncr_NotesReceivableRelatedPartiesInterestRate" name="NotesReceivableRelatedPartiesInterestRate" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="sncr_NumberOfBusinessesEntityIsManagedAndOperatedAs" name="NumberOfBusinessesEntityIsManagedAndOperatedAs" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_NumberOfVotesPerShare" name="NumberOfVotesPerShare" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_ObligationsUnderAcquisitionAgreementMember" name="ObligationsUnderAcquisitionAgreementMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_OpenwaveMessagingMember" name="OpenwaveMessagingMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_OperatingLeasesFutureMinimumPaymentsDueInFiveYearsAndThereafter" name="OperatingLeasesFutureMinimumPaymentsDueInFiveYearsAndThereafter" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="sncr_OperatingLossCarryforwardsUtilized" name="OperatingLossCarryforwardsUtilized" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_Operating_leasesMember" name="Operating_leasesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_OtherComprehensiveIncomeNetGainLossOnIntraEntityForeignCurrencyTransactionsArisingDuringPeriodNetOfTax" name="OtherComprehensiveIncomeNetGainLossOnIntraEntityForeignCurrencyTransactionsArisingDuringPeriodNetOfTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="sncr_PaymentsOnContingentConsideration" name="PaymentsOnContingentConsideration" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="sncr_PropertyEquipmentAndLeaseholdImprovementsMember" name="PropertyEquipmentAndLeaseholdImprovementsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_QuarterlyVestingAfterFirstAnniversaryMember" name="QuarterlyVestingAfterFirstAnniversaryMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_RedeemableNoncontrollingInterestMember" name="RedeemableNoncontrollingInterestMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_SalesServiceLevelPenalties" name="SalesServiceLevelPenalties" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="sncr_ScheduleOfFutureMinimumRentalPaymentsForCapitalAndOperatingLeasesTableTextBlock" name="ScheduleOfFutureMinimumRentalPaymentsForCapitalAndOperatingLeasesTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_SecondSucceedingFiveYearPeriodMember" name="SecondSucceedingFiveYearPeriodMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_SequentialTechnologyInternationalHoldingsLLCMember" name="SequentialTechnologyInternationalHoldingsLLCMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_SequentialTechnologyInternationalLLCMember" name="SequentialTechnologyInternationalLLCMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_ServiceLevelStandardsPolicyTextBlock" name="ServiceLevelStandardsPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardAggregateIntrinsicValueAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_ShareRepurchaseProgram2016Member" name="ShareRepurchaseProgram2016Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_SoftwarePurchasedMember" name="SoftwarePurchasedMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_SpatialSystemsNomineesPTYLimitedMember" name="SpatialSystemsNomineesPTYLimitedMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_StockCompensationExpenseForfeitureRateMember" name="StockCompensationExpenseForfeitureRateMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_StockIncentive2000And2006PlanMember" name="StockIncentive2000And2006PlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_StockIncentive2000PlanMember" name="StockIncentive2000PlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_StockIncentive2006PlanMember" name="StockIncentive2006PlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_StockIncentive2010PlanMember" name="StockIncentive2010PlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_SucceedingPeriodAfterTenYearsMember" name="SucceedingPeriodAfterTenYearsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="sncr_TaxWithholdingForShareBasedCompensationMember" name="TaxWithholdingForShareBasedCompensationMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_TermOfEmployeeStockPurchasePlan" name="TermOfEmployeeStockPurchasePlan" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_TopCustomersMember" name="TopCustomersMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_VestingFirstAnniversaryMember" name="VestingFirstAnniversaryMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_VestingMonthlyContinuousServiceAfterSecondAnniversaryMember" name="VestingMonthlyContinuousServiceAfterSecondAnniversaryMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_VestingMonthlyContinuousServiceMember" name="VestingMonthlyContinuousServiceMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_VestingPerformanceGoalAttainedMember" name="VestingPerformanceGoalAttainedMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="sncr_VestingSecondAnniversaryMember" name="VestingSecondAnniversaryMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
</xsd:schema>