<?xml version="1.0" encoding="us-ascii"?>
<!-- DFIN ActiveDisclosure(SM) XBRL Schema Document - http://www.dfinsolutions.com/ -->
<!-- Creation Date      : 2022-03-21T20:52:08.6934233+00:00 -->
<!-- Version            : 5.0.1.728 -->
<!-- Package ID         : 62f1e6ce62c0488b87c5a4b0358ccae1 -->
<!-- Copyright (c) 2022 Donnelley Financial Solutions, Inc. All Rights Reserved. -->
<xsd:schema xmlns:dei="http://xbrl.sec.gov/dei/2021q4" xmlns:us-types="http://fasb.org/us-types/2021-01-31" xmlns:stpr="http://xbrl.sec.gov/stpr/2021" xmlns:srt-types="http://fasb.org/srt-types/2021-01-31" xmlns:exch="http://xbrl.sec.gov/exch/2021" xmlns:sic="http://xbrl.sec.gov/sic/2021" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:sonm="http://www.sonimtech.com/20211231" xmlns:srt="http://fasb.org/srt/2021-01-31" xmlns:enum2="http://xbrl.org/2020/extensible-enumerations-2.0" xmlns:us-gaap="http://fasb.org/us-gaap/2021-01-31" xmlns:naics="http://xbrl.sec.gov/naics/2021" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:country="http://xbrl.sec.gov/country/2021" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:currency="http://xbrl.sec.gov/currency/2021" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2020-01-21" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.sonimtech.com/20211231" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <xsd:import schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" namespace="http://www.xbrl.org/2003/instance" />
  <xsd:import schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" namespace="http://www.xbrl.org/2003/linkbase" />
  <xsd:import schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd" namespace="http://xbrl.org/2005/xbrldt" />
  <xsd:import schemaLocation="https://www.xbrl.org/2020/extensible-enumerations-2.0.xsd" namespace="http://xbrl.org/2020/extensible-enumerations-2.0" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/country/2021/country-2021.xsd" namespace="http://xbrl.sec.gov/country/2021" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/currency/2021/currency-2021.xsd" namespace="http://xbrl.sec.gov/currency/2021" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd" namespace="http://xbrl.sec.gov/dei/2021q4" />
  <xsd:import schemaLocation="https://www.xbrl.org/dtr/type/2020-01-21/types.xsd" namespace="http://www.xbrl.org/dtr/type/2020-01-21" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/exch/2021/exch-2021.xsd" namespace="http://xbrl.sec.gov/exch/2021" />
  <xsd:import schemaLocation="http://www.xbrl.org/lrr/arcrole/factExplanatory-2009-12-16.xsd" namespace="http://www.xbrl.org/2009/arcrole/fact-explanatoryFact" />
  <xsd:import schemaLocation="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd" namespace="http://www.xbrl.org/2009/role/negated" />
  <xsd:import schemaLocation="http://www.xbrl.org/lrr/role/net-2009-12-16.xsd" namespace="http://www.xbrl.org/2009/role/net" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/naics/2021/naics-2021.xsd" namespace="http://xbrl.sec.gov/naics/2021" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/sic/2021/sic-2021.xsd" namespace="http://xbrl.sec.gov/sic/2021" />
  <xsd:import schemaLocation="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd" namespace="http://fasb.org/srt/2021-01-31" />
  <xsd:import schemaLocation="https://xbrl.fasb.org/srt/2021/elts/srt-roles-2021-01-31.xsd" namespace="http://fasb.org/srt-roles/2021-01-31" />
  <xsd:import schemaLocation="https://xbrl.fasb.org/srt/2021/elts/srt-types-2021-01-31.xsd" namespace="http://fasb.org/srt-types/2021-01-31" />
  <xsd:import schemaLocation="https://xbrl.sec.gov/stpr/2021/stpr-2021.xsd" namespace="http://xbrl.sec.gov/stpr/2021" />
  <xsd:import schemaLocation="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd" namespace="http://fasb.org/us-gaap/2021-01-31" />
  <xsd:import schemaLocation="https://xbrl.fasb.org/us-gaap/2021/elts/us-roles-2021-01-31.xsd" namespace="http://fasb.org/us-roles/2021-01-31" />
  <xsd:import schemaLocation="https://xbrl.fasb.org/us-gaap/2021/elts/us-types-2021-01-31.xsd" namespace="http://fasb.org/us-types/2021-01-31" />
  <xsd:annotation>
    <xsd:appinfo>
      <link:roleType id="TemplateLink" roleURI="http://www.sonimtech.com/20211231/role/TemplateLink" xmlns:link="http://www.xbrl.org/2003/linkbase">
        <link:definition>00000 - Document - Template Link</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="sonm-20211231_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:title="Calculation Links, all" xlink:type="simple" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="sonm-20211231_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:title="Definition Links, all" xlink:type="simple" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="sonm-20211231_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:title="Label Links, all" xlink:type="simple" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="sonm-20211231_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:title="Presentation Links, all" xlink:type="simple" />
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DocumentDocumentAndEntityInformation" id="Role_DocumentDocumentAndEntityInformation">
        <link:definition>100000 - Document - Document and Entity Information</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/StatementCONSOLIDATEDBALANCESHEETS" id="Role_StatementCONSOLIDATEDBALANCESHEETS">
        <link:definition>100010 - Statement - CONSOLIDATED BALANCE SHEETS</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/StatementCONSOLIDATEDBALANCESHEETSParenthetical" id="Role_StatementCONSOLIDATEDBALANCESHEETSParenthetical">
        <link:definition>100020 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/StatementCONSOLIDATEDSTATEMENTSOFOPERATIONS" id="Role_StatementCONSOLIDATEDSTATEMENTSOFOPERATIONS">
        <link:definition>100030 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/StatementCONSOLIDATEDSTATEMENTSOFOPERATIONSParenthetical" id="Role_StatementCONSOLIDATEDSTATEMENTSOFOPERATIONSParenthetical">
        <link:definition>100040 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/StatementCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY" id="Role_StatementCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY">
        <link:definition>100050 - Statement - CONSOLIDATED STATEMENTS OF STOCKHOLDERS&apos; EQUITY</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/StatementCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITYParenthetical" id="Role_StatementCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITYParenthetical">
        <link:definition>100060 - Statement - CONSOLIDATED STATEMENTS OF STOCKHOLDERS&apos; EQUITY (Parenthetical)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/StatementCONSOLIDATEDSTATEMENTOFCASHFLOWS" id="Role_StatementCONSOLIDATEDSTATEMENTOFCASHFLOWS">
        <link:definition>100070 - Statement - CONSOLIDATED STATEMENT OF CASH FLOWS</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureTheCompanyAndItsSignificantAccountingPolicies" id="Role_DisclosureTheCompanyAndItsSignificantAccountingPolicies">
        <link:definition>100080 - Disclosure - The Company and its Significant Accounting Policies</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureRevenueRecognition" id="Role_DisclosureRevenueRecognition">
        <link:definition>100090 - Disclosure - Revenue Recognition</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureFairValueMeasurement" id="Role_DisclosureFairValueMeasurement">
        <link:definition>100100 - Disclosure - Fair Value Measurement</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureSignificantBalanceSheetComponents" id="Role_DisclosureSignificantBalanceSheetComponents">
        <link:definition>100110 - Disclosure - Significant Balance Sheet Components</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureAccountsReceivable" id="Role_DisclosureAccountsReceivable">
        <link:definition>100120 - Disclosure - Accounts Receivable</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureBorrowings" id="Role_DisclosureBorrowings">
        <link:definition>100130 - Disclosure - Borrowings</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureConvertiblePreferredStockAndStockholdersEquity" id="Role_DisclosureConvertiblePreferredStockAndStockholdersEquity">
        <link:definition>100140 - Disclosure - Convertible Preferred Stock and Stockholders&apos; Equity</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureStockholdersEquity" id="Role_DisclosureStockholdersEquity">
        <link:definition>100150 - Disclosure - Stockholders&apos; Equity</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureStockBasedCompensation" id="Role_DisclosureStockBasedCompensation">
        <link:definition>100160 - Disclosure - Stock-based Compensation</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureIncomeTaxes" id="Role_DisclosureIncomeTaxes">
        <link:definition>100170 - Disclosure - Income Taxes</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureCommitmentsAndContingencies" id="Role_DisclosureCommitmentsAndContingencies">
        <link:definition>100180 - Disclosure - Commitments and Contingencies</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureNetLossPerShare" id="Role_DisclosureNetLossPerShare">
        <link:definition>100190 - Disclosure - Net Loss Per Share</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureEntityLevelInformation" id="Role_DisclosureEntityLevelInformation">
        <link:definition>100200 - Disclosure - Entity Level Information</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureRestructuringCosts" id="Role_DisclosureRestructuringCosts">
        <link:definition>100210 - Disclosure - Restructuring Costs</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureSubsequentEvents" id="Role_DisclosureSubsequentEvents">
        <link:definition>100220 - Disclosure - Subsequent Events</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureTheCompanyAndItsSignificantAccountingPoliciesPolicies" id="Role_DisclosureTheCompanyAndItsSignificantAccountingPoliciesPolicies">
        <link:definition>100230 - Disclosure - The Company and its Significant Accounting Policies (Policies)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureTheCompanyAndItsSignificantAccountingPoliciesTables" id="Role_DisclosureTheCompanyAndItsSignificantAccountingPoliciesTables">
        <link:definition>100240 - Disclosure - The Company and its Significant Accounting Policies (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureRevenueRecognitionTables" id="Role_DisclosureRevenueRecognitionTables">
        <link:definition>100250 - Disclosure - Revenue Recognition (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureFairValueMeasurementTables" id="Role_DisclosureFairValueMeasurementTables">
        <link:definition>100260 - Disclosure - Fair Value Measurement (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureSignificantBalanceSheetComponentsTables" id="Role_DisclosureSignificantBalanceSheetComponentsTables">
        <link:definition>100270 - Disclosure - Significant Balance Sheet Components (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureAccountsReceivableTables" id="Role_DisclosureAccountsReceivableTables">
        <link:definition>100280 - Disclosure - Accounts Receivable (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureBorrowingsTables" id="Role_DisclosureBorrowingsTables">
        <link:definition>100290 - Disclosure - Borrowings (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureConvertiblePreferredStockAndStockholdersEquityTables" id="Role_DisclosureConvertiblePreferredStockAndStockholdersEquityTables">
        <link:definition>100300 - Disclosure - Convertible Preferred Stock and Stockholders&apos; Equity (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureStockBasedCompensationTables" id="Role_DisclosureStockBasedCompensationTables">
        <link:definition>100310 - Disclosure - Stock-based Compensation (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureIncomeTaxesTables" id="Role_DisclosureIncomeTaxesTables">
        <link:definition>100320 - Disclosure - Income Taxes (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureCommitmentsAndContingenciesTables" id="Role_DisclosureCommitmentsAndContingenciesTables">
        <link:definition>100330 - Disclosure - Commitments and Contingencies (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureNetLossPerShareTables" id="Role_DisclosureNetLossPerShareTables">
        <link:definition>100340 - Disclosure - Net Loss Per Share (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureEntityLevelInformationTables" id="Role_DisclosureEntityLevelInformationTables">
        <link:definition>100350 - Disclosure - Entity Level Information (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureRestructuringCostsTables" id="Role_DisclosureRestructuringCostsTables">
        <link:definition>100360 - Disclosure - Restructuring Costs (Tables)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureTheCompanyAndItsSignificantAccountingPoliciesAdditionalInformationDetails" id="Role_DisclosureTheCompanyAndItsSignificantAccountingPoliciesAdditionalInformationDetails">
        <link:definition>100370 - Disclosure - The Company and its Significant Accounting Policies - Additional Information (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureTheCompanyAndItsSignificantAccountingPoliciesScheduleOfSeveranceLiabilityRelatedToRestructuringCostsDetails" id="Role_DisclosureTheCompanyAndItsSignificantAccountingPoliciesScheduleOfSeveranceLiabilityRelatedToRestructuringCostsDetails">
        <link:definition>100380 - Disclosure - The Company and its Significant Accounting Policies - Schedule of Severance Liability Related to the Restructuring Costs (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureRevenueRecognitionScheduleOfNetRevenueDisaggregateByProductCategoryDetails" id="Role_DisclosureRevenueRecognitionScheduleOfNetRevenueDisaggregateByProductCategoryDetails">
        <link:definition>100390 - Disclosure - Revenue Recognition - Schedule of Net Revenue Disaggregate by Product Category (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureRevenueRecognitionAdditionalInformationDetails" id="Role_DisclosureRevenueRecognitionAdditionalInformationDetails">
        <link:definition>100400 - Disclosure - Revenue Recognition - Additional Information (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureRevenueRecognitionSummaryOfContractBalancesDetails" id="Role_DisclosureRevenueRecognitionSummaryOfContractBalancesDetails">
        <link:definition>100410 - Disclosure - Revenue Recognition - Summary of Contract Balances (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureFairValueMeasurementSummaryOfFairValueAssetsAndLiabilitiesDetails" id="Role_DisclosureFairValueMeasurementSummaryOfFairValueAssetsAndLiabilitiesDetails">
        <link:definition>100420 - Disclosure - Fair Value Measurement - Summary of Fair Value Assets and Liabilities (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureSignificantBalanceSheetComponentsScheduleOfInventoryDetails" id="Role_DisclosureSignificantBalanceSheetComponentsScheduleOfInventoryDetails">
        <link:definition>100430 - Disclosure - Significant Balance Sheet Components - Schedule of Inventory (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureSignificantBalanceSheetComponentsAdditionalInformationDetails" id="Role_DisclosureSignificantBalanceSheetComponentsAdditionalInformationDetails">
        <link:definition>100440 - Disclosure - Significant Balance Sheet Components - Additional Information (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureSignificantBalanceSheetComponentsScheduleOfPrepaidExpensesAndOtherCurrentAssetsDetails" id="Role_DisclosureSignificantBalanceSheetComponentsScheduleOfPrepaidExpensesAndOtherCurrentAssetsDetails">
        <link:definition>100450 - Disclosure - Significant Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureSignificantBalanceSheetComponentsScheduleOfPropertyAndEquipmentDetails" id="Role_DisclosureSignificantBalanceSheetComponentsScheduleOfPropertyAndEquipmentDetails">
        <link:definition>100460 - Disclosure - Significant Balance Sheet Components - Schedule of Property and Equipment (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureSignificantBalanceSheetComponentsScheduleOfOtherAssetsDetails" id="Role_DisclosureSignificantBalanceSheetComponentsScheduleOfOtherAssetsDetails">
        <link:definition>100470 - Disclosure - Significant Balance Sheet Components - Schedule of Other Assets (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureSignificantBalanceSheetComponentsScheduleOfAccruedExpensesDetails" id="Role_DisclosureSignificantBalanceSheetComponentsScheduleOfAccruedExpensesDetails">
        <link:definition>100480 - Disclosure - Significant Balance Sheet Components - Schedule of Accrued Expenses (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureSignificantBalanceSheetComponentsScheduleOfWarrantyLiabilityWhichIsIncludedInAccruedExpensesOnConsolidatedBalanceSheetDetails" id="Role_DisclosureSignificantBalanceSheetComponentsScheduleOfWarrantyLiabilityWhichIsIncludedInAccruedExpensesOnConsolidatedBalanceSheetDetails">
        <link:definition>100490 - Disclosure - Significant Balance Sheet Components - Schedule of Warranty Liability Which is Included in Accrued Expenses on Consolidated Balance Sheet (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureAccountsReceivableScheduleOfComponentsOfCompanySReceivableDetails" id="Role_DisclosureAccountsReceivableScheduleOfComponentsOfCompanySReceivableDetails">
        <link:definition>100500 - Disclosure - Accounts Receivable - Schedule of Components of Company&apos;s Receivable (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureAccountsReceivableAdditionalInformationDetails" id="Role_DisclosureAccountsReceivableAdditionalInformationDetails">
        <link:definition>100510 - Disclosure - Accounts Receivable - Additional Information (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureBorrowingsAdditionalInformationDetails" id="Role_DisclosureBorrowingsAdditionalInformationDetails">
        <link:definition>100520 - Disclosure - Borrowings - Additional Information (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureBorrowingsScheduleOfComponentsOfLongTermDebtDetails" id="Role_DisclosureBorrowingsScheduleOfComponentsOfLongTermDebtDetails">
        <link:definition>100530 - Disclosure - Borrowings - Schedule of Components of Long-term Debt (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureBorrowingsScheduleOfFutureAggregateAnnualPrincipalPaymentOnAllLongTermDebtDetails" id="Role_DisclosureBorrowingsScheduleOfFutureAggregateAnnualPrincipalPaymentOnAllLongTermDebtDetails">
        <link:definition>100540 - Disclosure - Borrowings - Schedule of Future Aggregate Annual Principal Payment on All Long-Term Debt (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureConvertiblePreferredStockAndStockholdersEquityAdditionalInformationDetails" id="Role_DisclosureConvertiblePreferredStockAndStockholdersEquityAdditionalInformationDetails">
        <link:definition>100550 - Disclosure - Convertible Preferred Stock and Stockholders&apos; Equity - Additional Information (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureConvertiblePreferredStockAndStockholdersEquityScheduleOfCommonStockReservedDetails" id="Role_DisclosureConvertiblePreferredStockAndStockholdersEquityScheduleOfCommonStockReservedDetails">
        <link:definition>100560 - Disclosure - Convertible Preferred Stock and Stockholders&apos; Equity - Schedule of Common Stock Reserved (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureStockholdersEquityAdditionalInformationDetails" id="Role_DisclosureStockholdersEquityAdditionalInformationDetails">
        <link:definition>100570 - Disclosure - Stockholders&apos; Equity - Additional Information (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetails" id="Role_DisclosureStockBasedCompensationAdditionalInformationDetails">
        <link:definition>100580 - Disclosure - Stock-based Compensation - Additional Information (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureStockBasedCompensationScheduleOfStockBasedCompensationExpenseDetails" id="Role_DisclosureStockBasedCompensationScheduleOfStockBasedCompensationExpenseDetails">
        <link:definition>100590 - Disclosure - Stock-based Compensation - Schedule of Stock-based Compensation Expense (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStockOptionActivityDetails" id="Role_DisclosureStockBasedCompensationSummaryOfStockOptionActivityDetails">
        <link:definition>100600 - Disclosure - Stock-based Compensation - Summary of Stock Option Activity (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureStockBasedCompensationSummaryOfFairValueOfOptionsGrantsDetails" id="Role_DisclosureStockBasedCompensationSummaryOfFairValueOfOptionsGrantsDetails">
        <link:definition>100610 - Disclosure - Stock-based Compensation - Summary of Fair Value of Options Grants (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureStockBasedCompensationSummaryOfOutstandingRSUSDetails" id="Role_DisclosureStockBasedCompensationSummaryOfOutstandingRSUSDetails">
        <link:definition>100620 - Disclosure - Stock-based Compensation - Summary of Outstanding RSU&apos;s (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureIncomeTaxesScheduleOfIncomeLossBeforeIncomeTaxesAndComponentsOfProvisionBenefitForIncomeTaxesDetails" id="Role_DisclosureIncomeTaxesScheduleOfIncomeLossBeforeIncomeTaxesAndComponentsOfProvisionBenefitForIncomeTaxesDetails">
        <link:definition>100630 - Disclosure - Income Taxes - Schedule of Income (Loss) Before Income Taxes and Components of Provision (Benefit) for Income Taxes (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureIncomeTaxesScheduleOfEffectiveTaxRateDiffersFromFederalStatutoryRateDetails" id="Role_DisclosureIncomeTaxesScheduleOfEffectiveTaxRateDiffersFromFederalStatutoryRateDetails">
        <link:definition>100640 - Disclosure - Income Taxes - Schedule of Effective Tax Rate Differs from Federal Statutory Rate (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureIncomeTaxesScheduleOfSignificantComponentsOfDeferredTaxAssetsAndLiabilitiesDetails" id="Role_DisclosureIncomeTaxesScheduleOfSignificantComponentsOfDeferredTaxAssetsAndLiabilitiesDetails">
        <link:definition>100650 - Disclosure - Income Taxes - Schedule of Significant Components of Deferred Tax Assets and Liabilities (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetails" id="Role_DisclosureIncomeTaxesAdditionalInformationDetails">
        <link:definition>100660 - Disclosure - Income Taxes - Additional Information (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureIncomeTaxesScheduleOfEstimateOfCumulativeForeignEarningsDetails" id="Role_DisclosureIncomeTaxesScheduleOfEstimateOfCumulativeForeignEarningsDetails">
        <link:definition>100670 - Disclosure - Income Taxes - Schedule of Estimate of Cumulative Foreign Earnings (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureIncomeTaxesScheduleOfNetOperatingLossCarryoversDetails" id="Role_DisclosureIncomeTaxesScheduleOfNetOperatingLossCarryoversDetails">
        <link:definition>100680 - Disclosure - Income Taxes - Schedule of Net Operating Loss Carryovers (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureIncomeTaxesScheduleOfResearchAndDevelopmentCreditCarryforwardsDetails" id="Role_DisclosureIncomeTaxesScheduleOfResearchAndDevelopmentCreditCarryforwardsDetails">
        <link:definition>100690 - Disclosure - Income Taxes - Schedule of Research and Development Credit Carryforwards (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureIncomeTaxesSummaryOfActivityRelatedToUnrecognizedTaxBenefitsDetails" id="Role_DisclosureIncomeTaxesSummaryOfActivityRelatedToUnrecognizedTaxBenefitsDetails">
        <link:definition>100700 - Disclosure - Income Taxes - Summary of Activity Related to Unrecognized Tax Benefits (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetails" id="Role_DisclosureCommitmentsAndContingenciesAdditionalInformationDetails">
        <link:definition>100710 - Disclosure - Commitments and Contingencies - Additional Information (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureCommitmentsAndContingenciesFutureMinimumLeasePaymentsUnderNoncancelableOperatingLeaseCommitmentsDetails" id="Role_DisclosureCommitmentsAndContingenciesFutureMinimumLeasePaymentsUnderNoncancelableOperatingLeaseCommitmentsDetails">
        <link:definition>100720 - Disclosure - Commitments and Contingencies - Future Minimum Lease Payments under Noncancelable Operating Lease Commitments (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureNetLossPerShareAdditionalInformationDetails" id="Role_DisclosureNetLossPerShareAdditionalInformationDetails">
        <link:definition>100730 - Disclosure - Net Loss Per Share - Additional Information (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureNetLossPerShareScheduleOfComputationOfBasicAndDilutedNetLossPerShareDetails" id="Role_DisclosureNetLossPerShareScheduleOfComputationOfBasicAndDilutedNetLossPerShareDetails">
        <link:definition>100740 - Disclosure - Net Loss Per Share - Schedule of Computation of Basic and Diluted Net Loss Per Share (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureNetLossPerShareSummaryOfPotentiallyDilutiveCommonSharesWereExcludedFromCalculationOfDilutedNetLossPerShareDetails" id="Role_DisclosureNetLossPerShareSummaryOfPotentiallyDilutiveCommonSharesWereExcludedFromCalculationOfDilutedNetLossPerShareDetails">
        <link:definition>100750 - Disclosure - Net Loss Per Share - Summary of Potentially Dilutive Common Shares were Excluded from Calculation of Diluted Net Loss Per Share (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureEntityLevelInformationAdditionalInformationDetails" id="Role_DisclosureEntityLevelInformationAdditionalInformationDetails">
        <link:definition>100760 - Disclosure - Entity Level Information - Additional Information (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureEntityLevelInformationSummaryOfRevenueByRegionDetails" id="Role_DisclosureEntityLevelInformationSummaryOfRevenueByRegionDetails">
        <link:definition>100770 - Disclosure - Entity Level Information - Summary of Revenue by Region (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureEntityLevelInformationCompositionOfRevenuesDetails" id="Role_DisclosureEntityLevelInformationCompositionOfRevenuesDetails">
        <link:definition>100780 - Disclosure - Entity Level Information - Composition of Revenues (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureEntityLevelInformationPercentageOfTotalRevenuesDetails" id="Role_DisclosureEntityLevelInformationPercentageOfTotalRevenuesDetails">
        <link:definition>100790 - Disclosure - Entity Level Information - Percentage of Total Revenues (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureRestructuringCostsAdditionalInformationDetails" id="Role_DisclosureRestructuringCostsAdditionalInformationDetails">
        <link:definition>100800 - Disclosure - Restructuring Costs - Additional Information (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureRestructuringCostsSummaryOfRestructuringCostsDetails" id="Role_DisclosureRestructuringCostsSummaryOfRestructuringCostsDetails">
        <link:definition>100810 - Disclosure - Restructuring Costs - Summary of Restructuring Costs (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.sonimtech.com/20211231/taxonomy/role/DisclosureSubsequentEventsAdditionalInformationDetails" id="Role_DisclosureSubsequentEventsAdditionalInformationDetails">
        <link:definition>100820 - Disclosure - Subsequent Events - Additional Information (Details)</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
    </xsd:appinfo>
  </xsd:annotation>
  <xsd:element id="sonm_StockIssuedDuringPeriodSharesRestrictedStockUnits" name="StockIssuedDuringPeriodSharesRestrictedStockUnits" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_StockIssuedDuringPeriodValueRestrictedStockUnits" name="StockIssuedDuringPeriodValueRestrictedStockUnits" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_IncreaseDecreaseInNonTradeReceivable" name="IncreaseDecreaseInNonTradeReceivable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_ProceedsFromPPPLoan" name="ProceedsFromPPPLoan" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="sonm_RepaymentOfPPPLoan" name="RepaymentOfPPPLoan" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_SettlementOfLongTermDebtWithIssuanceOfCommonStock" name="SettlementOfLongTermDebtWithIssuanceOfCommonStock" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_CompanyAndSignificantAccountingPoliciesAbstract" name="CompanyAndSignificantAccountingPoliciesAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_SignificantBalanceSheetComponentsAbstract" name="SignificantBalanceSheetComponentsAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_DescriptionOfBusinessPolicyTextBlock" name="DescriptionOfBusinessPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_LiquidityAndAbilityToContinueAsGoingConcernPolicyTextBlock" name="LiquidityAndAbilityToContinueAsGoingConcernPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_NonRecurringEngineeringToolingAndPurchasedSoftwareLicensesPolicyPolicyTextBlock" name="NonRecurringEngineeringToolingAndPurchasedSoftwareLicensesPolicyPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_ShippingAndHandlingCostPolicyPolicyTextBlock" name="ShippingAndHandlingCostPolicyPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_DeferredRevenuesPolicyPolicyTextBlock" name="DeferredRevenuesPolicyPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_SalesTaxesPolicyPolicyTextBlock" name="SalesTaxesPolicyPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_ATMProgramPolicyTextBlock" name="ATMProgramPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_InitialPublicOfferingPolicyPolicyTextBlock" name="InitialPublicOfferingPolicyPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_ScheduleOfCommonStockReservedTableTestBlock" name="ScheduleOfCommonStockReservedTableTestBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_ScheduleOfEstimateOfCumulativeForeignEarningsTableTextBlock" name="ScheduleOfEstimateOfCumulativeForeignEarningsTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_CompanyAndSignificantAccountingPoliciesLineItems" name="CompanyAndSignificantAccountingPoliciesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_CompanyAndSignificantAccountingPoliciesTable" name="CompanyAndSignificantAccountingPoliciesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_NonRecurringEngineeringToolingAndPurchasedSoftwareLicensesMember" name="NonRecurringEngineeringToolingAndPurchasedSoftwareLicensesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_June2021AtTheMarketOfferingProgramMember" name="June2021AtTheMarketOfferingProgramMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_AtTheMarketOfferingProgramMember" name="AtTheMarketOfferingProgramMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_TwoThousandTwentyOfferingMember" name="TwoThousandTwentyOfferingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_BadDebtExpense" name="BadDebtExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="sonm_ForeignCashAndCashEquivalentsAtCarryingValue" name="ForeignCashAndCashEquivalentsAtCarryingValue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="sonm_NumbersOfEmployees" name="NumbersOfEmployees" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_NumberOfContractors" name="NumberOfContractors" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_PercentageOfReductionInForce" name="PercentageOfReductionInForce" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_RestructuringCostPaid" name="RestructuringCostPaid" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_RestructuringCostOfRevenue" name="RestructuringCostOfRevenue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_PercentageOfGrossProceedsFromSaleOfCommonStock" name="PercentageOfGrossProceedsFromSaleOfCommonStock" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_InitialPublicOfferingClosingDate" name="InitialPublicOfferingClosingDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_UnderwritingDiscountsAndCommissions" name="UnderwritingDiscountsAndCommissions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="sonm_SmartphonesMember" name="SmartphonesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_FeaturePhonesMember" name="FeaturePhonesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_AccessoriesAndOtherMember" name="AccessoriesAndOtherMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_EstimatedLifeOfParticularModelPhone" name="EstimatedLifeOfParticularModelPhone" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_ContractWithCustomerLiabilityRecognitionOfRevenue" name="ContractWithCustomerLiabilityRecognitionOfRevenue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_ContractWithCustomerLiabilityCurrentAdditionOfRevenue" name="ContractWithCustomerLiabilityCurrentAdditionOfRevenue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_ContractualLiabilityMember" name="ContractualLiabilityMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_InventoryDevicesForResale" name="InventoryDevicesForResale" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="sonm_InventoryAccessories" name="InventoryAccessories" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="sonm_AccruedLossOnPurchaseCommitments" name="AccruedLossOnPurchaseCommitments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="sonm_RefundableValueAddedTaxesCurrent" name="RefundableValueAddedTaxesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="sonm_PrepaidServicesExpenses" name="PrepaidServicesExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="sonm_PrepaidLicensesAndRoyaltiesCurrent" name="PrepaidLicensesAndRoyaltiesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="sonm_DirectorsAndOfficersInsuranceCurrent" name="DirectorsAndOfficersInsuranceCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="sonm_FurnitureFixturesAndOfficeEquipmentMember" name="FurnitureFixturesAndOfficeEquipmentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_DeferredServices" name="DeferredServices" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="sonm_AdvancesToThirdPartyManufacturers" name="AdvancesToThirdPartyManufacturers" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="sonm_AccruedCustomerAllowancesCurrent" name="AccruedCustomerAllowancesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_AccrualForGoodsReceivedNotInvoiced" name="AccrualForGoodsReceivedNotInvoiced" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_AccruedContractualObligationsCurrent" name="AccruedContractualObligationsCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_AccruedContractorsCurrent" name="AccruedContractorsCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_AccruedResearchAndDevelopmentCurrent" name="AccruedResearchAndDevelopmentCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_AccruedShippingExpensesCurrent" name="AccruedShippingExpensesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_AccruedReturnsAllowance" name="AccruedReturnsAllowance" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_AccruedLegalExpensesCurrent" name="AccruedLegalExpensesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_CustomersOneMember" name="CustomersOneMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_CustomersTwoMember" name="CustomersTwoMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_NumberOfCustomer" name="NumberOfCustomer" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="sonm_AccountsReceivablePercentage" name="AccountsReceivablePercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="sonm_SubordinatedTermLoanAndSecurityAgreementMember" name="SubordinatedTermLoanAndSecurityAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_BRileyPrincipalInvestmentsLimitedLiabilityCompanyMember" name="BRileyPrincipalInvestmentsLimitedLiabilityCompanyMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_NoteAmendmentAndDebtCancellationAgreementMember" name="NoteAmendmentAndDebtCancellationAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_PromissoryNotesPayableMember" name="PromissoryNotesPayableMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_MinimumPrincipalAmountOutstandingOfDefinedRepaymentPenalties" name="MinimumPrincipalAmountOutstandingOfDefinedRepaymentPenalties" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_PrepaymentPenaltyDescription" name="PrepaymentPenaltyDescription" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_DebtPrepaymentPenaltiesPercentage" name="DebtPrepaymentPenaltiesPercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_DebtInstrumentPeriodicPaymentNumberOfEqualQuarterlyInstallments" name="DebtInstrumentPeriodicPaymentNumberOfEqualQuarterlyInstallments" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="sonm_CapitalStockParValue" name="CapitalStockParValue" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="sonm_SharesSubjectToOptionsToPurchaseCommonStockMember" name="SharesSubjectToOptionsToPurchaseCommonStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_UnvestedRestrictedStockUnitsMember" name="UnvestedRestrictedStockUnitsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_SharesSubjectToWarrantsToPurchaseCommonStockMember" name="SharesSubjectToWarrantsToPurchaseCommonStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_TwoThousandAndNineteenEquityIncentivePlanMember" name="TwoThousandAndNineteenEquityIncentivePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_TwoThousandAndTwelveEquityIncentivePlanMember" name="TwoThousandAndTwelveEquityIncentivePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_GrantedToTenPercentStockholdersMember" name="GrantedToTenPercentStockholdersMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_TwoThousandAndNineteenEmployeeStockPurchasePlanMember" name="TwoThousandAndNineteenEmployeeStockPurchasePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_TwoThousandNineteenPlanMember" name="TwoThousandNineteenPlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_CommonStockCapitalSharesReservedForFutureIssuanceTermOfAnnualIncrease" name="CommonStockCapitalSharesReservedForFutureIssuanceTermOfAnnualIncrease" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_IncreaseInCommonStockReservedForIssuanceAsPercentageOfTotalNumberOfSharesOfCapitalStockOutstandingOnLastDayOfPriorCalendarYear" name="IncreaseInCommonStockReservedForIssuanceAsPercentageOfTotalNumberOfSharesOfCapitalStockOutstandingOnLastDayOfPriorCalendarYear" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="sonm_IncreaseInCommonStockReservedForIssuanceOfNumberOfSharesOfCapitalStockOutstandingOnLastDayOfPriorCalendarYear" name="IncreaseInCommonStockReservedForIssuanceOfNumberOfSharesOfCapitalStockOutstandingOnLastDayOfPriorCalendarYear" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="sonm_CommonStockReservedForIssuanceDescription" name="CommonStockReservedForIssuanceDescription" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_IncreaseInCommonStockReservedForIssuanceOfNumberOfSharesOfCapitalStockOutstanding" name="IncreaseInCommonStockReservedForIssuanceOfNumberOfSharesOfCapitalStockOutstanding" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="sonm_ShareBasedCompensationArrangementByShareBasedPaymentAwardDollarValueOfBonusesFixedAmount" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardDollarValueOfBonusesFixedAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="sonm_ShareBasedCompensationArrangementByShareBasedPaymentAwardFullyVestedIncludedInAccruedExpenses" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardFullyVestedIncludedInAccruedExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsCancelledInPeriod" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsCancelledInPeriod" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsCancelledInPeriodWeightedAverageExercisePrice" name="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsCancelledInPeriodWeightedAverageExercisePrice" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsReleasedInPeriod" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsReleasedInPeriod" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_DeferredTaxExpenseBenefit" name="DeferredTaxExpenseBenefit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="sonm_EffectiveIncomeTaxRateReconciliationStockBasedCompensation" name="EffectiveIncomeTaxRateReconciliationStockBasedCompensation" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_EffectiveIncomeTaxRateReconciliationTaxCostCredits" name="EffectiveIncomeTaxRateReconciliationTaxCostCredits" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_EffectiveIncomeTaxRateReconciliationGlobalIntangibleLowTaxedIncomeInclusion" name="EffectiveIncomeTaxRateReconciliationGlobalIntangibleLowTaxedIncomeInclusion" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_IncomeTaxDisclosureLineItems" name="IncomeTaxDisclosureLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_IncomeTaxDisclosureTable" name="IncomeTaxDisclosureTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_EstimateOfCumulativeForeignEarnings" name="EstimateOfCumulativeForeignEarnings" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_FederalResearchCreditsExpireDate" name="FederalResearchCreditsExpireDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_UnrecognizedTaxBenefitsAccountedForReductionInDeferredTaxAssets" name="UnrecognizedTaxBenefitsAccountedForReductionInDeferredTaxAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccruedLiability" name="UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccruedLiability" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_NonCancelableOperatingLeasesExpirationBeginningYear" name="NonCancelableOperatingLeasesExpirationBeginningYear" type="xbrli:gYearItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_WirelessEssentialPatentHoldersMember" name="WirelessEssentialPatentHoldersMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_OtherProvidersOfIntegratedTechnologiesMember" name="OtherProvidersOfIntegratedTechnologiesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_PearsonActionMember" name="PearsonActionMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_PresidentAndChiefOperatingOfficerMember" name="PresidentAndChiefOperatingOfficerMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_OtherKeyEmployeesMember" name="OtherKeyEmployeesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_ConsultantsMember" name="ConsultantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_TransactionBonusPlanMember" name="TransactionBonusPlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_RoyaltyPaymentPercentOfNetRevenues" name="RoyaltyPaymentPercentOfNetRevenues" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_RoyaltyExpireYear" name="RoyaltyExpireYear" type="xbrli:gYearItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_PercentageOfConsiderationPayable" name="PercentageOfConsiderationPayable" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_TermOfPlan" name="TermOfPlan" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_PercentageOfOwnershipInterestInPlan" name="PercentageOfOwnershipInterestInPlan" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_CustomerOneMember" name="CustomerOneMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_CustomerTwoMember" name="CustomerTwoMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_CanadaAndLatinAmericaMember" name="CanadaAndLatinAmericaMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_EuropeAndMiddleEastMember" name="EuropeAndMiddleEastMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_CustomerAMember" name="CustomerAMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_CustomerBMember" name="CustomerBMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_CustomerCMember" name="CustomerCMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_CustomerDMember" name="CustomerDMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_CustomersMember" name="CustomersMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_PercentageOfReductionInEmployees" name="PercentageOfReductionInEmployees" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_NumberOfEmployeesAndContractors" name="NumberOfEmployeesAndContractors" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_FutureBusinessVolumeAgreementAmount" name="FutureBusinessVolumeAgreementAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="sonm_MinimumFutureBusinessVolumeAgreementCommittedAmount" name="MinimumFutureBusinessVolumeAgreementCommittedAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_PaymentRelatedToOutsourcingOfSoftwareDevelopment" name="PaymentRelatedToOutsourcingOfSoftwareDevelopment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="sonm_SupportWorkerMember" name="SupportWorkerMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_EliminateEmployeesMember" name="EliminateEmployeesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="sonm_RestructuringReserveExpensedCost" name="RestructuringReserveExpensedCost" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="sonm_FailureToMaintainCommonStockMinimumClosingBidPrice" name="FailureToMaintainCommonStockMinimumClosingBidPrice" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="sonm_ClosingBidPricePeriod" name="ClosingBidPricePeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_MinimumClosingBidPricePerShare" name="MinimumClosingBidPricePerShare" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_ComplianceRegainCalendarDays" name="ComplianceRegainCalendarDays" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="sonm_AdditionalComplianceRegainCalendarDays" name="AdditionalComplianceRegainCalendarDays" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
</xsd:schema>
