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  <xsd:element abstract="true" id="hlit_ContractManufacturingMember" name="ContractManufacturingMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_CustomerRelationshipsContractsMember" name="CustomerRelationshipsContractsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
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  <xsd:element id="hlit_DefinedBenefitPlanContributionMaximumAmountByPlanPerParticipantEligibleForEmployerMatching" name="DefinedBenefitPlanContributionMaximumAmountByPlanPerParticipantEligibleForEmployerMatching" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_DevelopedCoreTechnologyMember" name="DevelopedCoreTechnologyMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
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  <xsd:element abstract="true" id="hlit_EdgeAndAccessProductsMember" name="EdgeAndAccessProductsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
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  <xsd:element abstract="true" id="hlit_FastVDOMember" name="FastVDOMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_FederalJurisdictionMember" name="FederalJurisdictionMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_FiniteLivedIntangibleAssetsAmortizationExpenseOperatingExpense" name="FiniteLivedIntangibleAssetsAmortizationExpenseOperatingExpense" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
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  <xsd:element abstract="true" id="hlit_GrantedPriorToFebruary2006Member" name="GrantedPriorToFebruary2006Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
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  <xsd:element id="hlit_IncomeTaxReconciliationForLosses" name="IncomeTaxReconciliationForLosses" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
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  <xsd:element id="hlit_IncreasedNumberOfSharesReservedForEveryUnitForfeited" name="IncreasedNumberOfSharesReservedForEveryUnitForfeited" nillable="true" substitutionGroup="xbrli:item" type="xbrli:pureItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_InternationalMember" name="InternationalMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_LeaseExpirationMonthAndYear" name="LeaseExpirationMonthAndYear" nillable="true" substitutionGroup="xbrli:item" type="xbrli:gYearMonthItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_LineofCreditFacilityCovenantCertainAssetstoCertainLiabilitiesLessDeferredRevenueRatio" name="LineofCreditFacilityCovenantCertainAssetstoCertainLiabilitiesLessDeferredRevenueRatio" nillable="true" substitutionGroup="xbrli:item" type="xbrli:pureItemType" xbrli:periodType="duration" />
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  <xsd:element abstract="true" id="hlit_MaintenanceAgreementsAndRelatedRelationshipsMember" name="MaintenanceAgreementsAndRelatedRelationshipsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_MaximumDefinedBenefitPlanPercentageOfContributedByEligibleParticipantsreceivingemployermatching" name="MaximumDefinedBenefitPlanPercentageOfContributedByEligibleParticipantsreceivingemployermatching" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_MaximumExercisePriceAsPercentageToFairValue" name="MaximumExercisePriceAsPercentageToFairValue" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_MoreLikelyThanNotThresholdRecognitionofUncertainTaxPosition" name="MoreLikelyThanNotThresholdRecognitionofUncertainTaxPosition" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="hlit_NetAssetsOfDisposalGroupIncludingDiscontinuedOperationCurrentAndNoncurrent" name="NetAssetsOfDisposalGroupIncludingDiscontinuedOperationCurrentAndNoncurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="hlit_NumberOfCommonStocksDepositedToSecurePostClosingIndemnificationObligationsOfHolders" name="NumberOfCommonStocksDepositedToSecurePostClosingIndemnificationObligationsOfHolders" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_NumberOfCustomerAccountingForMoreThanTenPercentOfAccountsReceivable" name="NumberOfCustomerAccountingForMoreThanTenPercentOfAccountsReceivable" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element id="hlit_NumberOfEmployeesTerminated" name="NumberOfEmployeesTerminated" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_NumberOfEmployeesTerminatedRequiredtobeHired" name="NumberOfEmployeesTerminatedRequiredtobeHired" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_NumberOfPatentInfringements" name="NumberOfPatentInfringements" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="hlit_OmneonMember" name="OmneonMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
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  <xsd:element abstract="true" id="hlit_OpenMarketTransactionMember" name="OpenMarketTransactionMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_OperatingExpensesMember" name="OperatingExpensesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_OperatingLossCarryforwardsStateRelatedToStockOption" name="OperatingLossCarryforwardsStateRelatedToStockOption" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="hlit_OperatingResultsOfDiscontinuedOperationTableTextBlock" name="OperatingResultsOfDiscontinuedOperationTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_OptionsAndRestrictedStockUnitsMember" name="OptionsAndRestrictedStockUnitsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
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  <xsd:element id="hlit_PercentageAddedToLiborToFacilitateLineOfCredit" name="PercentageAddedToLiborToFacilitateLineOfCredit" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_PercentageOfEstimatedFairValueExceedingCarryingValue" name="PercentageOfEstimatedFairValueExceedingCarryingValue" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_PercentageOfRevenueRecognizedUponCompletionContractMethod" name="PercentageOfRevenueRecognizedUponCompletionContractMethod" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_PrepaidsAndOtherCurrentAssetsMember" name="PrepaidsAndOtherCurrentAssetsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_PriceAtWhichIncentiveStockOptionsMayBeGranted" name="PriceAtWhichIncentiveStockOptionsMayBeGranted" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_PriceAtWhichNonStatutoryStockOptionsMayBeGranted" name="PriceAtWhichNonStatutoryStockOptionsMayBeGranted" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ProceedsFromEscrowDepositByReimbursementInCash" name="ProceedsFromEscrowDepositByReimbursementInCash" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="hlit_ProceedsFromSaleOfDiscontinuedOperation" name="ProceedsFromSaleOfDiscontinuedOperation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_ProductionAndPlayoutMember" name="ProductionAndPlayoutMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_RangeOfPayrollDeduction" name="RangeOfPayrollDeduction" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ReceivablesTradeAndOtherAccountsReceivableAllowanceForDoubtfulAccountsReturnsAndDiscountsTableTextBlock" name="ReceivablesTradeAndOtherAccountsReceivableAllowanceForDoubtfulAccountsReturnsAndDiscountsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ReducedNumberOfSharesReservedForEveryUnitGranted" name="ReducedNumberOfSharesReservedForEveryUnitGranted" nillable="true" substitutionGroup="xbrli:item" type="xbrli:pureItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ReimbursementAmountReceivedFromEscrow" name="ReimbursementAmountReceivedFromEscrow" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="hlit_ReimbursementReceivedFromEscrowCommonStockNumberOfShares" name="ReimbursementReceivedFromEscrowCommonStockNumberOfShares" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ReimbursementReceivedFromEscrowCommonStockValue" name="ReimbursementReceivedFromEscrowCommonStockValue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_ResearchAndDevelopmentTaxCreditExtensionAmericanTaxpayerReliefActMember" name="ResearchAndDevelopmentTaxCreditExtensionAmericanTaxpayerReliefActMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_RestructuringReserveSettledWithCashNetOfSubleaseIncome" name="RestructuringReserveSettledWithCashNetOfSubleaseIncome" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="hlit_RevenueRecognitionPeriod" name="RevenueRecognitionPeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ScheduleOfDiscontinuedOperationsIncomeStatementDisclosureTableTextBlock" name="ScheduleOfDiscontinuedOperationsIncomeStatementDisclosureTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ScheduleOfNetGainLossOnSalesOfBusinessesAndAssetsTableTextBlock" name="ScheduleOfNetGainLossOnSalesOfBusinessesAndAssetsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ScheduleOfShareBasedCompensationArrangementByStockOptionAndRestrictedStockUnitActivityTableTextBlock" name="ScheduleOfShareBasedCompensationArrangementByStockOptionAndRestrictedStockUnitActivityTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsTable" name="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_SellingGeneralAndAdministrativeExpenseMember" name="SellingGeneralAndAdministrativeExpenseMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_SeriesaParticipatingPreferredStockMember" name="SeriesaParticipatingPreferredStockMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_ServiceAndSupportMember" name="ServiceAndSupportMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ShareBasedCompensationArrangementByShareBasedAwardNumberOfSharesAvailableForGrantExercised" name="ShareBasedCompensationArrangementByShareBasedAwardNumberOfSharesAvailableForGrantExercised" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ShareBasedCompensationArrangementByShareBasedPaymentAwardDecreaseInNumberOfReserveSharesPerShareGranted" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardDecreaseInNumberOfReserveSharesPerShareGranted" nillable="true" substitutionGroup="xbrli:item" type="xbrli:pureItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAuthorizesInPeriodWeightedAverageGrantDateFairValue" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAuthorizesInPeriodWeightedAverageGrantDateFairValue" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisesInPeriodWeightedAverageGrantDateFairValue" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExercisesInPeriodWeightedAverageGrantDateFairValue" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodExercisePrice" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodExercisePrice" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodAndExpectedToVestTotalFairValue" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodAndExpectedToVestTotalFairValue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="hlit_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationDate1" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationDate1" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ShareBasedCompensationArrangementByShareBasedPaymentAwardIncreaseInNumberOfReserveSharesPerShareForfeited" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardIncreaseInNumberOfReserveSharesPerShareForfeited" nillable="true" substitutionGroup="xbrli:item" type="xbrli:pureItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrantAndForfeitedOrCancelledInPeriod" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrantAndForfeitedOrCancelledInPeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
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  <xsd:element id="hlit_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesReleasedInPeriod" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesReleasedInPeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionAuthorizedWeightedAverageExercisePrice" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionAuthorizedWeightedAverageExercisePrice" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionExercisesInPeriodWeightedAverageExercisePrice" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionExercisesInPeriodWeightedAverageExercisePrice" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionGrantsInPeriodWeightedAverageExercisePrice" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionGrantsInPeriodWeightedAverageExercisePrice" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ShareBasedCompensationArrangementByShareBasedPaymentAwardOtherThanOptionsVestedAndExpectedToVestOutstandingNumber" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOtherThanOptionsVestedAndExpectedToVestOutstandingNumber" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="instant" />
  <xsd:element id="hlit_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfPlanFunded" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfPlanFunded" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsLineItems" name="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_SharebasedCompensationArrangementbySharebasedPaymentAwardAnnualContributionsPerEmployeePercentRefunded" name="SharebasedCompensationArrangementbySharebasedPaymentAwardAnnualContributionsPerEmployeePercentRefunded" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ShareholdersRightsPlanExpirationDate" name="ShareholdersRightsPlanExpirationDate" nillable="true" substitutionGroup="xbrli:item" type="us-types:dateStringItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_SolutionSalesPolicyTextBlock" name="SolutionSalesPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_StockPlan1995Member" name="StockPlan1995Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_StockRepurchaseProgramIncreaseOfCommonStockRepurchaseAuthorization" name="StockRepurchaseProgramIncreaseOfCommonStockRepurchaseAuthorization" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="hlit_StockRepurchasedAndRetiredDuringPeriodSharesAverageCostPerShare" name="StockRepurchasedAndRetiredDuringPeriodSharesAverageCostPerShare" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_SubsequentGrantsMember" name="SubsequentGrantsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_SummaryOfActivityInAllowancesForDoubtfulAccountsReturnsAndDiscountsTableTextBlock" name="SummaryOfActivityInAllowancesForDoubtfulAccountsReturnsAndDiscountsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_SummaryOfPropertyAndEquipmentAbstract" name="SummaryOfPropertyAndEquipmentAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_SummaryOfRevenueByNetGeographicRegionAbstract" name="SummaryOfRevenueByNetGeographicRegionAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_SummaryOfSignificantAccountingPoliciesLineItems" name="SummaryOfSignificantAccountingPoliciesLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_SummaryOfSignificantAccountingPoliciesTable" name="SummaryOfSignificantAccountingPoliciesTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_SunnyvaleBuildingMember" name="SunnyvaleBuildingMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_SwitzerlandMember" name="SwitzerlandMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_TaxCreditCarryforwardsExpirationDate1" name="TaxCreditCarryforwardsExpirationDate1" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_TransitionServicesAgreementsExpense" name="TransitionServicesAgreementsExpense" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_UnitedStatesMember" name="UnitedStatesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_UnrestrictedCashCashEquivalentsAndShortTermInvestmentsToCurrentLiabilitiesRatio" name="UnrestrictedCashCashEquivalentsAndShortTermInvestmentsToCurrentLiabilitiesRatio" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ValuationAllowanceDeferredTaxAssetAddition" name="ValuationAllowanceDeferredTaxAssetAddition" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="hlit_ValuationAllowanceDeferredTaxAssetDeductions" name="ValuationAllowanceDeferredTaxAssetDeductions" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="hlit_ValueOfStockPurchaseRightPercentageOfCallOption" name="ValueOfStockPurchaseRightPercentageOfCallOption" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="hlit_ValueOfStockPurchaseRightPercentageOfPutOption" name="ValueOfStockPurchaseRightPercentageOfPutOption" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="hlit_VideoProcessingProductsMember" name="VideoProcessingProductsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
</xsd:schema>
