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  <xs:element id="hlit_Provisionfornoncashwarrant" abstract="false" name="Provisionfornoncashwarrant" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="hlit_UnrecognizedTaxBenefitsThatWouldNotImpactEffectiveTaxRate" abstract="false" name="UnrecognizedTaxBenefitsThatWouldNotImpactEffectiveTaxRate" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="hlit_DefinedBenefitPlanNetPeriodicBenefitCostCreditInterestCostStatementOfIncomeOrComprehensiveIncomeExtensibleListNotDisclosedFlag" abstract="false" name="DefinedBenefitPlanNetPeriodicBenefitCostCreditInterestCostStatementOfIncomeOrComprehensiveIncomeExtensibleListNotDisclosedFlag" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="hlit_DefinedBenefitPlanExpectedFutureBenefitPayments" abstract="false" name="DefinedBenefitPlanExpectedFutureBenefitPayments" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="hlit_LoansPayableNoncurrentMember" abstract="true" name="LoansPayableNoncurrentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_ConvertibleNoteDue2022Member" abstract="true" name="ConvertibleNoteDue2022Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationMobilityRate" abstract="false" name="DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationMobilityRate" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="hlit_BroadbandSegmentMember" abstract="true" name="BroadbandSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_SummaryOfRevenueByNetGeographicRegionAbstract" abstract="true" name="SummaryOfRevenueByNetGeographicRegionAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="hlit_LineOfCreditFacilityMaturityFactorPeriodRequired" abstract="false" name="LineOfCreditFacilityMaturityFactorPeriodRequired" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="hlit_ProceedsFromSaleOfEquitySecuritiesConsiderationReceivable" abstract="false" name="ProceedsFromSaleOfEquitySecuritiesConsiderationReceivable" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="hlit_DirectorOptionPlans2002Member" abstract="true" name="DirectorOptionPlans2002Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_ValueOfStockPurchaseRightPercentageOfPutOption" abstract="false" name="ValueOfStockPurchaseRightPercentageOfPutOption" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="hlit_AdjustmentsToAdditionalPaidInCapitalReclassificationFromMezzanineEquityToEquity" abstract="false" name="AdjustmentsToAdditionalPaidInCapitalReclassificationFromMezzanineEquityToEquity" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="hlit_DeferredTaxAssetsCapitalizedResearchAndDevelopmentExpenses" abstract="false" name="DeferredTaxAssetsCapitalizedResearchAndDevelopmentExpenses" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="hlit_SellingGeneralAndAdministrativeExpenseMember" abstract="true" name="SellingGeneralAndAdministrativeExpenseMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_StockIssuedDuringPeriodValueExerciseOfWarrants" abstract="false" name="StockIssuedDuringPeriodValueExerciseOfWarrants" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="hlit_CommonStockCapitalSharesReservedForFutureIssuanceIncreaseDecrease" abstract="false" name="CommonStockCapitalSharesReservedForFutureIssuanceIncreaseDecrease" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="hlit_ProceedsFromSaleOfEquitySecuritiesTotalConsideration" abstract="false" name="ProceedsFromSaleOfEquitySecuritiesTotalConsideration" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="hlit_A2022NewOrModifiedLeaseAgreementsMember" abstract="true" name="A2022NewOrModifiedLeaseAgreementsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_EncodingcomIncMember" abstract="true" name="EncodingcomIncMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_ProceedsFromSaleOfEquitySecuritiesWithoutReadilyDeterminableFairValue" abstract="false" name="ProceedsFromSaleOfEquitySecuritiesWithoutReadilyDeterminableFairValue" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="hlit_IncentiveStockOptionOrNonStatutoryStockOptionWithExercisePriceLessThan100FairValueOfCommonStockOnGrantDateMember" abstract="true" name="IncentiveStockOptionOrNonStatutoryStockOptionWithExercisePriceLessThan100FairValueOfCommonStockOnGrantDateMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_AllCountriesExceptUnitedStatesIsraelAndFranceMember" abstract="true" name="AllCountriesExceptUnitedStatesIsraelAndFranceMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_EquitySecuritiesWithoutReadilyDeterminableFairValueRealizedGainLossOnDisposal" abstract="false" name="EquitySecuritiesWithoutReadilyDeterminableFairValueRealizedGainLossOnDisposal" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="hlit_StockIssuedDuringPeriodSharesExerciseOfWarrants" abstract="false" name="StockIssuedDuringPeriodSharesExerciseOfWarrants" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="hlit_ApplianceIntegrationMember" abstract="true" name="ApplianceIntegrationMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_DiscountPercentageOnPurchaseOfStock" abstract="false" name="DiscountPercentageOnPurchaseOfStock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="hlit_AdjustmentsToAdditionalPaidInCapitalReclassificationFromEquityToMezzanineEquity" abstract="false" name="AdjustmentsToAdditionalPaidInCapitalReclassificationFromEquityToMezzanineEquity" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="hlit_ProceedsFromSaleOfEquitySecuritiesExpirationPeriod" abstract="false" name="ProceedsFromSaleOfEquitySecuritiesExpirationPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="hlit_SOFRForInterestPeriodOfOneThreeOrSixMonthsMember" abstract="true" name="SOFRForInterestPeriodOfOneThreeOrSixMonthsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_SaaSServiceMember" abstract="true" name="SaaSServiceMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_TVNMember" abstract="true" name="TVNMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_ComcastMember" abstract="true" name="ComcastMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_PRSUsMember" abstract="true" name="PRSUsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="hlit_ConvertibleNotedue2024Member" abstract="true" name="ConvertibleNotedue2024Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_OneMonthLIBORMember" abstract="true" name="OneMonthLIBORMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_VideoSegmentMember" abstract="true" name="VideoSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_SocieteGeneraleSAMember" abstract="true" name="SocieteGeneraleSAMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_DeferredTaxAssetsOperatingLeaseLiabilities" abstract="false" name="DeferredTaxAssetsOperatingLeaseLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="hlit_AmortizationOfIntangibleOperatingExpenses" abstract="false" name="AmortizationOfIntangibleOperatingExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="hlit_LoansBackedByFrenchResearchAndDevelopmentTaxCreditReceivablesMember" abstract="true" name="LoansBackedByFrenchResearchAndDevelopmentTaxCreditReceivablesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_SharebasedCompensationArrangementbySharebasedPaymentAwardMinimumEmployeeSubscriptionRate" abstract="false" name="SharebasedCompensationArrangementbySharebasedPaymentAwardMinimumEmployeeSubscriptionRate" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="hlit_InternationalMember" abstract="true" name="InternationalMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_ValuationAllowanceDeferredTaxAssetDeductions" abstract="false" name="ValuationAllowanceDeferredTaxAssetDeductions" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="hlit_MRSUsMember" abstract="true" name="MRSUsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_LoansPayableCurrentMember" abstract="true" name="LoansPayableCurrentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="hlit_Stockpricegreaterorequal130percentofNoteConversionPriceMember" abstract="true" name="Stockpricegreaterorequal130percentofNoteConversionPriceMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
