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Filed Pursuant to Rule 424(b)(4)Registration No. 333-230887

3,571,429 Shares

Common Stock

Sonim Technologies, Inc. is offering 3,571,429 shares of its common stock. This is our initial public offering and no public market currently exists forshares of our common stock. The initial public offering price is $11.00 per share.

Our common stock has been approved for listing on The Nasdaq Global Market under the symbol “SONM.”

We are an “emerging growth company” as defined under the federal securities laws and, as such, may elect to comply with certain reduced publiccompany reporting requirements for this and future filings. Investing in our common stock involves risks. See “Risk Factors” beginning on page13.

Neither the Securities and Exchange Commission in the United States nor any other regulatory body has approved or disapproved of thesesecurities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

Per Share Total Public offering price $ 11.00 $39,285,719 Underwriting discounts and commissions(1) $ 0.77 $ 2,750,000 Proceeds, before expenses, to Sonim $ 10.23 $36,535,719 (1) See the section titled “Underwriting (Conflicts of Interest)” for additional information regarding compensation payable to the underwriters.

At our request, the underwriters have reserved up to 5% of the shares of common stock offered by this prospectus for sale, at the initial public offeringprice, to certain individuals associated with us. See the section titled “Underwriting (Conflicts of Interest)—Directed Share Program.”

We and the selling stockholder have granted the underwriters the right to purchase up to an additional 535,714 shares of common stock, of which 30,000shares will be offered and sold by the selling stockholder. We will not receive any proceeds from any sale of shares by the selling stockholder.

The underwriters expect to deliver the shares of common stock to purchasers on May 14, 2019.

Oppenheimer & Co. Lake Street

National Securities Corporation

May 9, 2019

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. Serving the people who serve us with rugged, reliable mobile solutions. SONIM®

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Ruggedized solutions designed and built to perform in challenging work environments. SONIM ®

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Purpose-built for demanding conditions and those who work in them. SONIM®

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TA BLE OF CONTENTS Page Prospectus Summary 1 Risk Factors 13 Special Note Regarding Forward-Looking Statements 40 Industry and Market Data 42 Use of Proceeds 43 Dividend Policy 44 Capitalization 45 Dilution 47 Selected Consolidated Financial Data 49 Management’s Discussion and Analysis of Financial Condition and Results of Operations 50 Business 65 Management 77 Executive Compensation 84 Certain Relationships and Related Party Transactions 97 Principal and Selling Stockholders 102 Description of Capital Stock 104 Shares Eligible for Future Sale 109 Material U.S. Federal Income Tax Considerations for Non-U.S. Holders of Common Stock 112 Underwriting (Conflicts of Interest) 116 Legal Matters 122 Experts 122 Where You Can Find Additional Information 122 Index to Financial Statements F-1

Through and including June 3, 2019 (the 25th day after the date of this prospectus), all dealers that buy, sell or trade our common stock, whetheror not participating in this offering, may be required to deliver a prospectus. This is in addition to the dealers’ obligation to deliver a prospectuswhen acting as underwriters and with respect to their unsold allotments or subscriptions.

Neither we, the selling stockholder nor the underwriters have authorized anyone to provide any information other than that, or to make any representationsother than those, contained in this prospectus or in any free writing prospectuses we or the selling stockholder have prepared. Neither we, the sellingstockholder nor the underwriters take any responsibility for, and cannot provide any assurance as to the reliability of, any other information that othersmay provide you. We, the selling stockholder and the underwriters are offering to sell, and seeking offers to buy, shares of common stock only undercircumstances and in jurisdictions where offers and sales are permitted. The information contained in this prospectus is accurate only as of the date of thisprospectus, regardless of the time of delivery of this prospectus or of any sale of the common stock.

For investors outside the United States: Neither we, the selling stockholder nor any of the underwriters have taken any action that would permit thisoffering or possession or distribution of this prospectus in any jurisdiction where action for that purpose is required, other than in the United States.Persons outside of the United States who come into possession of this prospectus must inform themselves about, and observe any restrictions relating to,the offering of the shares of common stock and the distribution of this prospectus outside of the United States.

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Certain Definitions

As used in this prospectus, unless otherwise noted or the context requires otherwise:

• “channel partners” refers to wireless carriers and other distributors that purchase our products, including under master sales arrangements, for further

resale and distribution to end customers and end users as well as ecosystem partners, such as accessory vendors or application developers, with whomwe collaborate to promote our collective products to end customers and end users;

• “customers” refers generally to channel partners and end customers as well as end users who may have purchased products from us directly orreceived them through a channel partner or end customer;

• “end customers” refers to enterprises, organizations or other entities that purchase our products through channel partners or directly from us anddeploy those products among their task workers for use in the field or workplace; and

• “end users” refers to task workers who use our products in the field or workplace.

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PROSPECTUS SUMMARY

This summary highlights information contained elsewhere in this prospectus and does not contain all of the information that you should consider inmaking your investment decision. Before investing in our common stock, you should carefully read this entire prospectus, including our consolidatedfinancial statements and the related notes thereto and the information set forth in the sections titled “Risk Factors,” “Special Note RegardingForward-Looking Statements” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations.” In this prospectus,“Sonim,” “Sonim Technologies, Inc.,” the “company,” “we,” “us” and “our” refer to Sonim Technologies, Inc. and its consolidated subsidiaries.

Overview

We are a leading U.S. provider of ultra-rugged mobile phones and accessories designed specifically for task workers physically engaged in their workenvironments, often in mission-critical roles. We currently sell our ruggedized mobile phones and accessories to three of the four largest wirelesscarriers in the United States—AT&T, Sprint and Verizon—as well as the three largest wireless carriers in Canada—Bell, Rogers and Telus Mobility.Our phones and accessories connect workers with voice, data and workflow applications in two end markets: industrial enterprise and public sector.

Task workers in these end markets have historically been limited to pen and paper and single-purpose electronic devices, such as barcode scanners,location-tracking devices and sensors, to accomplish specific daily tasks. These single-purpose devices have historically run on proprietary networks,such as land mobile radio, or LMR, networks, which enable push-to-talk, or PTT, services for voice communications. We provide Android-baseddevices that consolidate and integrate multiple functions into a single ruggedized solution running on commercial wireless networks at a total cost ofownership that we believe is significantly lower than comparable offerings with improved productivity and safety of task workers.

Our solutions fall into three main categories: (i) ultra-rugged mobile phones based on the Android platform that are capable of attaching to bothpublic and private wireless networks, (ii) industrial-grade accessories and (iii) cloud-based software and application services. End customers of oursolutions include construction, energy and utility, hospitality, logistics, manufacturing, public sector and transportation entities that primarilypurchase our phones and accessories through their wireless carriers. All of our devices run on the Android operating system, providing a familiar andintuitive user interface, and our smartphones have access to a library of millions of applications available through the Google Play Store. We havealso implemented dozens of application programming interfaces, or APIs, specific to our mobile phones and have partnered with over 800 applicationdevelopers to create a purpose-built experience for our end users using these applications on our mobile phones.

As of January 2019, we were the only privately held mobile phone provider to have a stocked product with three of the four largest U.S. wirelesscarriers: AT&T, Sprint and Verizon, meaning that these carriers test and certify our mobile phones on their networks and maintain inventory in theirwarehouses that they then sell through their enterprise and retail sales teams to end customers, often on a subsidized or financed basis.

We enter into master sales arrangements with the majority of our channel partners (including channel partners contributing over 90% of our totalrevenues for the year ended December 31, 2018) under which our partners purchase our solutions for distribution on a purchase order basis. Underthese arrangements, we and the channel partners determine sales channel distribution in connection with pricing (including any discounts and priceprotection) and positioning of each particular mobile device product. We also offer customer incentives in the form of funds used for channelmarketing, as well as other limited promotional incentives, such as sales volume

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incentives, in exchange for retail price reductions. We may also offer non-recurring engineering, or NRE, services in the form of third-party designservices relating to the design of materials and software licenses used in the manufacturing of our products.

Our Industry

Communication, productivity and safety among task workers has always been a central requirement in business-critical and mission-criticalenvironments. Organizations with remote and disparate workers—from police and firefighters to construction, oil rig and manufacturing workers—need an extremely durable solution that provides reliable and secure voice, data and workflow applications.

Ruggedized mobile phones are well-suited for industrial enterprise and other critical infrastructure applications due to their durability andfunctionality in a range of environments. Equipping workers with smarter mobile phones also enables more efficient communication with andbetween field employees, and enhances the information that decision-makers use to deploy resources within their organizations.

Industrial Enterprise Market Opportunity

We estimate that in the United States and Canada in 2018, there were 37.6 million task workers across verticals in our industrial enterprise endmarkets who could benefit from our solutions, including construction, energy and utility, facilities management, manufacturing and transportationand logistics. The extreme durability and enhanced voice and text communication capabilities of our devices enable these workers to be stationed inremote and hazardous environments, while remaining connected to their central command center at all times.

Public Sector Market Opportunity

Mobile phones enable public safety officers to gather real-time information collected across multiple systems and to respond and react to changingcircumstances. Following the tragic events of September 11, 2001, Congress, U.S. public safety agencies and other critical infrastructure entities tookaction to ensure that the mobile phones of first responders remain fully functional and interoperable at all times. The establishment of a nationwidepublic safety broadband network, or FirstNet, in 2017 and other public safety-focused mobile networks has created a significant opportunity for us tobe the leading mobile solution provider for public sector task workers.

Our Ruggedized Solution

• Durability and reliability. Our mobile phones can withstand a variety of harsh environments and are supported by our industry-leading three-yearcomprehensive manufacturer’s warranty, which includes physical damage. Key features of our rugged devices include: (i) puncture, shock,pressure and impact resistance, (ii) waterproof and dustproof construction, (iii) dual-shift battery life, (iv) extra-loud audio, (v) glove-friendlydesign, (vi) operational in and resistant to extreme temperatures, and (vii) chemical resistance.

• Increased communication and visibility through an enterprise. Our solutions are used to track locations, update and manage various tasks and

enable communication with and between task workers. In addition, our devices are specifically designed to capture, store and analyze multipledata types for enterprise needs, enabling them to make timely and more informed decisions.

• Enhanced functionality through software and hardware configurations. Our solutions allow end customers and task workers to customize ourmobile phones using Android-based applications and vertical-specific accessories to address their varying needs. Enterprises and agencies canleverage the millions of applications available on the Google Play Store, our dozens of device-specific APIs, and our industrial accessories tocreate a purpose-built solution to meet the specific use cases of their task workers.

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• Ease of use. Our devices are designed to look and function similarly to the latest generation of consumer-focused mobile phones with additionalfeatures for various enterprise-specific purposes, and also run on the Android operating system which has a familiar and intuitive interface. Theyprovide familiar characteristics to many single-purpose devices, such as dedicated physical buttons for PTT and barcode scanning, and offer asimplified user interface, which helps minimize the learning curve for task workers who are transitioning from LMR or data capture devices.

• Consolidation of devices. By combining commonly-used applications and functionality into one ruggedized device with the option for add-ons,

enterprises can reduce the need for multiple, single-purpose devices. We believe that replacing outdated single-purpose devices with a Sonimdevice can enhance fleets’ mobility and economically streamline equipment updates or replacements.

Our Strategy

• Invest in sales channel partnerships and brand marketing to drive sales. We intend to continue to invest in our channel partnerships to furtherpenetrate the industrial enterprise and public sector markets we target by leveraging their large direct sales forces. We are also increasing ourinvestment in marketing the Sonim brand and our solutions to end customers in these target markets. In doing so, we believe that we will be ableto raise brand awareness, deepen existing channel partnerships, and acquire and retain new channel and end customers of our solutions.

• Position Sonim as the leading solution for the public sector. We intend to leverage the large-scale deployment of our solutions over dedicatedLTE networks in the public safety market to further position us as a trusted solution within the cities that we serve. As public safety agenciescontinue to shift to these dedicated LTE networks, we intend to deliver mobility solutions to increase security, safety and efficiency across theircities.

• Expand our subscription-based products and services. We intend to expand our cloud-based software platform to (i) deploy value-addedapplications like Sonim Scan, which integrates a barcode scanning engine with the native camera on our XP8 device, (ii) be the launching pointfor third-party application providers and (iii) provide data analytics and reporting to our end customers. We intend to continue investing in thecapabilities of our software platform to create and expand subscription-based products and services for our end customers.

• Expand internationally. We are exploring public safety infrastructure projects in Australia and Europe. We will continue to invest in and expand

our international sales teams to address the needs of the agencies involved and their wireless carriers that are expected to build public safetywireless networks similar to those being deployed in North America.

• Expand into adjacent target markets. We intend to market our solutions in large adjacent vertical end markets, such as retail enterprises andadditional agencies within the federal government.

Our Target Markets

Our ruggedized mobility solutions are designed for two end markets: industrial enterprise and public sector. For the industrial enterprise, our targetmarkets include: (i) construction, (ii) energy and utility, (iii) facilities management, (iv) manufacturing and (v) transportation and logistics. For thepublic sector, our target markets include (i) public safety and (ii) federal government.

Preliminary Estimated Unaudited Financial Results for the Three Months Ended March 31, 2019

Set forth below are certain estimated preliminary results for the three months ended March 31, 2019. We have provided ranges, rather than specificamounts, because these interim results are preliminary and subject to

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change. These ranges are based on the information currently available to us as of the date of this prospectus. Our actual unaudited financial results forthe three months ended March 31, 2019 are not yet available and our closing procedures for the three months ended March 31, 2019 are not yetcompleted. As such, our actual results may vary from the estimated preliminary results presented here and will not be finalized until after thecompletion of this offering.

These are forward-looking statements and are not guarantees of future performance and may differ from actual results. These estimates should not beviewed as a substitute for our full interim or annual financial statements prepared in accordance with GAAP. There can be no assurance that theseestimates will be realized, and estimates are subject to risks and uncertainties, many of which are not within our control. Please see the sections titled“Risk Factors” and “Special Note Regarding Forward-Looking Statements.” These estimated interim preliminary results should be read inconjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and the consolidated financialstatements and related notes thereto for prior periods included elsewhere in this prospectus.

The following estimated interim preliminary results have been prepared by, and are the responsibility of, management. Our independent registeredpublic accounting firm, Moss Adams LLP, has not audited, reviewed or performed any procedures with respect to the interim preliminary financialresults for the three months ended March 31, 2019 and the unaudited interim financial results for the three months ended March 31, 2018.Accordingly, Moss Adams LLP does not express an opinion or any other form of assurance with respect thereto.

Three Months Ended March 31, March 31, 2019 2018 Low High (unaudited, in thousands) Selected Financial Data

Net revenue $ 18,190 $25,000 $27,000 Cost of revenues 12,927 16,150 17,500 Gross profit 5,263 8,850 9,500 Net loss (5,071) (6,300) (6,000)

Other Data Adjusted EBITDA(1) $ (3,631) $ (5,050) $ (4,541)

(1) Adjusted EBITDA is a non-GAAP financial measure that is presented as supplemental disclosure. See footnote 2 to “—Summary Consolidated Financial Data” for a

discussion of how we define and calculate Adjusted EBITDA and its limitations. The following table provides a reconciliation of net loss, the most closelycomparable U.S. GAAP financial measure, to Adjusted EBITDA.

Three Months Ended

March 31,

2018 March 31, 2019

Low High (unaudited, in thousands) Net loss $ (5,071) $(6,300) $(6,000)

Depreciation and amortization 467 534 550 Stock-based compensation 33 45 60 Interest expense 406 421 450 Income tax expense 534 250 399

Adjusted EBITDA $ (3,631) $(5,050) $(4,541)

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Total revenues

Our preliminary estimated total revenues for the three months ended March 31, 2019 compared to the three months ended March 31, 2018 improvedby approximately $6.8 million to $8.8 million. The increase was driven primarily by (i) the acceptance and launch of commercial sales of our XP3device by Sprint and (ii) increased mobile phone sales volumes to major wireless carriers, including AT&T.

Cost of revenues

Our preliminary estimated cost of revenues for the three months ended March 31, 2019 compared to the three months ended March 31, 2018 increasedby approximately $3.2 million to $4.5 million, driven primarily by an increase in number of mobile phones sold. While total estimated cost ofrevenues increased for the three months ended March 31, 2019 compared to the same period in 2018, estimated cost of revenues per mobile phonesold improved for the three months ended March 31, 2019 compared to the same period in 2018 as a result of a reduction in per unit labor costs byapproximately 40% and per unit materials costs by approximately 8% to 10%. These reductions were driven primarily by improved manufacturingand factory efficiencies, as well as increased production volumes, which resulted in lower labor and overhead costs and improved cost leverage withsuppliers.

Gross profit and margin

Our preliminary estimated gross profit for the three months ended March 31, 2019 compared to the three months ended March 31, 2018 improved byapproximately $3.6 million to $4.2 million. The improvement was driven primarily by an increase in revenues by approximately 37% to 48% frommobile phone sales in the three months ended March 31, 2019 compared to the three months ended March 31, 2018, as well as reduced cost ofrevenues per mobile phone sold for the three months ended March 31, 2019 compared to the three months ended March 31, 2018, in each case asdescribed above.

Net loss

Our preliminary estimated net loss for the three months ended March 31, 2019 compared to the three months ended March 31, 2018 increased byabout approximately $0.9 million to $1.2 million, driven primarily by increases in operating expenses of approximately $5.0 million to $5.7 million,partially offset by an increase in total revenues and related gross profit. Third party engineering expenses increased by approximately $1.7 million to$1.9 million due to costs associated with technical approval processes required by wireless carrier customers as well as new product launches;research and development expenses increased by approximately $1.4 million to $1.6 million primarily due to increased employee headcount; sales andmarketing expenses increased by approximately $1.1 million to $1.3 million due to new employee hires and new product launch marketing expenses;and general and administrative expenses increased by approximately $0.9 million to $1.0 million due to increased employee compensation and hiringof new consultants as well as higher audit fees.

Adjusted EBITDA

Our preliminary estimated Adjusted EBITDA for the three months ended March 31, 2019 compared to the three months ended March 31, 2018decreased by approximately $0.9 million to $1.4 million, primarily due to higher operating expenses, partially offset by increased gross profit, asdescribed above.

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Risks Affecting Our Business

Our business is subject to numerous risks and uncertainties, including those highlighted in the section titled “Risk Factors” immediately following thisprospectus summary. These risks include, but are not limited to, the following:

• We have not been profitable in recent years and may not achieve or maintain profitability in the future.

• We rely on our channel partners to generate a substantial majority of our revenues. If these channel partners fail to perform or if we cannot enterinto agreements with channel partners on favorable terms, our operating results could be significantly harmed.

• We are materially dependent on the adoption of our solutions by both the industrial enterprise and public sector markets, and if end customers inthose markets do not purchase our solutions, our revenues will be adversely impacted and we may not be able to expand into other markets.

• We participate in a competitive industry, which may become more competitive. Competitors with greater resources and significant experience in

high-volume product manufacturing may be able to respond more quickly and cost-effectively than we can to new or emerging technologies andchanges in customer requirements.

• Defects in our products could reduce demand for our products and result in a loss of sales, delay in market acceptance and injury to our reputation,which would adversely impact our business.

• If our business does not grow as we expect, or if we fail to manage our growth effectively, our operating results and business would suffer.

• We are required to undergo a lengthy customization and certification process for each wireless carrier customer, which increases our operatingexpenses, and failure to obtain such certification would adversely impact our results of operations and financial condition.

• If we fail to adequately forecast demand for our inventory and supply needs, we could incur additional costs or experience manufacturing delays,which could reduce our gross margin or cause us to delay or even lose sales.

• We may not be able to continue to develop solutions to address user needs effectively in an industry characterized by ongoing change and rapidtechnological advances.

• In 2017 and 2018, approximately 76% and 80%, respectively, of our revenues were derived from our top five channel partners. The loss of, or

significant reduction in orders from, any of these channel partners could significantly reduce our revenues and adversely impact our operatingresults.

Channels for Disclosure of Information

Investors, the media and others should note that, following the completion of this offering, we intend to announce material information to the publicthrough filings with the Securities and Exchange Commission, or the SEC, the investor relations page on our website, press releases, and publicconference calls and webcasts.

Corporate Information

We were incorporated in Delaware in August 1999 as NaviSpin.com, Inc. In December 2001, we changed our name to Sonim Technologies, Inc. Ourprincipal executive offices are located at 1875 South Grant Street, Suite 750, San Mateo, California 94402 and our telephone number is (650)378-8100. Our website address is www.sonimtech.com. Our website and the information contained therein or accessible through it is not incorporatedinto this prospectus or the registration statement of which it forms a part.

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“Sonim,” the Sonim logo and other trademarks or service marks of Sonim appearing in this prospectus are our property. This prospectus containsadditional trade names, trademarks, and service marks of other companies, which are the property of their respective owners. We do not intend ouruse or display of other companies’ trade names, trademarks or service marks to imply a relationship with, or endorsement or sponsorship of us by,these other companies.

Emerging Growth Company

We qualify as an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012, or the JOBS Act. An emerging growthcompany may take advantage of specified reduced reporting and related requirements that are otherwise generally applicable to public companies.These reduced requirements include:

• an exemption from compliance with the auditor attestation requirement on the effectiveness of our internal control over financial reporting;

• an exemption from compliance with any requirement that the Public Company Accounting Oversight Board may adopt regarding a supplement tothe auditor’s report providing additional information about the audit and the financial statements;

• reduced disclosure about executive compensation arrangements;

• an exemption from the requirements to obtain a non-binding advisory vote on executive compensation or golden parachute arrangements; and

• extended transition periods for complying with new or revised accounting standards.

We may take advantage of these provisions until we are no longer an emerging growth company. We would cease to be an “emerging growthcompany” upon the earliest to occur of: (i) the last day of the fiscal year in which we have more than $1.07 billion in annual revenues; (ii) the date wequalify as a large accelerated filer under the rules of the SEC, which means the market value of our shares of common stock that is held bynon-affiliates with at least $700.0 million as of the prior June 30th; (iii) the date on which we have, in any three-year period, issued more than$1.0 billion in non-convertible debt securities and (iv) the last day of the fiscal year ending after the fifth anniversary of this offering. We may chooseto take advantage of some or all of these reduced reporting burdens. We have taken advantage of certain reduced reporting burdens in this prospectus.Accordingly, the information contained herein may be different from the information you receive from other public companies in which you holdstock.

The JOBS Act permits an emerging growth company like us to take advantage of an extended transition period to comply with new or revisedaccounting standards applicable to public companies. We have elected to use this extended transition period until we are no longer an emerginggrowth company or until we affirmatively and irrevocably opt out of the extended transition period. As a result, our financial statements may not becomparable to companies that comply with new or revised accounting pronouncements as of public company effective dates.

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THE OFFERING Common stock offered by us 3,571,429 shares

Over-allotment option to purchase additional shares ofcommon stock

We and the selling stockholder have granted the underwriters an option for a period of 30days to purchase up to 535,714 additional shares of our common stock. We will not receiveany proceeds from any sale of our shares of common stock in this offering by the sellingstockholder. The selling stockholder will only sell shares of common stock in this offering ifthe underwriters exercise their option to purchase additional shares.

Common stock to be outstanding after this offering 19,509,722 shares (or 20,015,436 shares if the underwriters exercise their option to purchaseadditional shares of common stock in full).

Use of proceeds We estimate that the net proceeds to us from this offering will be approximately$32.3 million, or approximately $37.5 million if the underwriters exercise their over-allotmentoption to purchase additional shares in full, after deducting underwriting discounts andcommissions and estimated offering expenses payable by us.

We intend to use the net proceeds of this offering primarily for general corporate purposes,including working capital, expanded sales and marketing activities, increased research anddevelopment expenditures and funding our growth strategies. We expect to use a portion ofthe net proceeds we receive to satisfy anticipated tax withholding and remittance obligationsrelated to the RSA Settlement in connection with this offering. We may also use a portion ofthe net proceeds from the offering to prepay principal amounts outstanding and accruedinterest under the B. Riley Convertible Note, including prepayment penalties. See “Use ofProceeds.”

Directed Share Program At our request, the underwriters have reserved up to 178,571 shares of common stock, or 5%of the shares offered by us pursuant to this prospectus for sale, at the initial public offeringprice, through a directed share program, to our employees and family members of ouremployees. If purchased by these persons and entities, these shares will not be subject to a180-day lock-up restriction, except to the extent that the purchasers of such shares areotherwise subject to lock-up or market stand-off agreements as a result of their relationshipswith us. The number of shares of common stock available for sale to the general public will bereduced by the number of reserved shares sold to these persons and entities. Any reservedshares of our common stock that are not so purchased will be offered by the underwriters tothe general public on the same terms as the other shares of our common stock offered by thisprospectus. See the section titled “Underwriting (Conflicts of Interest)—Directed ShareProgram.”

Nasdaq trading symbol “SONM”

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Conflicts of interest Entities affiliated with B. Riley Financial, Inc., which beneficially owns more than 10% ofour common stock, own approximately 49% of National Holdings Inc., which wholly ownsNational Securities Corporation, one of the underwriters in this offering. Because NationalSecurities Corporation is an underwriter for this offering, it is deemed to have a “conflict ofinterest” within the meaning of FINRA Rule 5121(f)(5)(B). Accordingly, this offering isbeing made in compliance with the requirements of FINRA Rule 5121. Oppenheimer & Co.Inc. is acting as the qualified independent underwriter. National Securities Corporation willnot confirm sales to discretionary accounts without the prior written approval of the accountholder. See “Underwriting (Conflicts of Interest).”

Risk factors See “Risk Factors” for a discussion of risks you should carefully consider before investing inour common stock.

The number of shares of common stock that will be outstanding immediately after this offering is based on 15,938,293 shares of common stock(including (i) 155,338 shares of our common stock issuable upon the exercise of a warrant immediately prior to the completion of this offering, or theWarrant Exercise, and (ii) 191,598 shares of our common stock issuable upon the vesting and net settlement (after withholding an estimated amountof 191,598 shares to satisfy associated estimated income tax obligations (based on the initial public offering price and applicable tax withholdingrates)) of restricted stock awards prior to the closing of this offering (based on fully-diluted shares outstanding immediately prior to the closing of thisoffering before giving effect to the offering and sale of shares of common stock in this offering) that are expected to be granted to our chief executiveofficer immediately prior to the closing of this offering (as described under “Executive Compensation—Agreements with Our Named ExecutiveOfficers—Mr. Plaschke”), or the RSA Settlement) outstanding as of December 31, 2018, and excludes:

• 1,099,278 shares of common stock issuable upon the conversion of 75% of the aggregate principal amount and accrued interest outstanding as of

December 31, 2018 under the subordinated secured convertible promissory note issued to B. Riley Principal Investments, LLC, or the B. RileyConvertible Note;

• 956 shares of common stock issuable upon the exercise of warrants outstanding as of December 31, 2018 with a weighted-average exercise priceof $6.20 per share;

• 1,320,197 shares of common stock issuable upon the exercise of stock options outstanding as of December 31, 2018, with a weighted-averageexercise price of $0.77 per share;

• 637,213 shares of common stock issuable upon the exercise of stock options granted after December 31, 2018, with an exercise price of $10.94per share;

• 128,000 shares issuable upon the vesting of restricted stock units granted after December 31, 2018;

• 2,222,046 shares of our common stock reserved for future issuance under our equity compensation plans, which will become effective prior to thecompletion of this offering, consisting of:

• 1,885,039 shares of common stock reserved for future issuance under our 2019 Plan, effective as of the date of this prospectus, plus the

number of shares underlying outstanding stock awards granted under the 2012 Plan that expire, or are forfeited, cancelled, withheld orreacquired, as well as any automatic increases in the number of shares of common stock reserved for future issuance under this plan; and

• 337,007 shares of common stock reserved for issuance under our 2019 Employee Stock Purchase Plan, or ESPP, which will become

effective upon the execution of the underwriting agreement for this offering as well as any automatic increases in the number of shares ofcommon stock reserved for future issuance under this plan.

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Upon the execution and delivery of the underwriting agreement related to this offering, we will cease granting awards under the 2012 Plan. We do notexpect any shares to remain available for issuance under the 2012 Plan upon the execution and delivery of the underwriting agreement related to thisoffering. See the section titled “Executive Compensation—Employee Benefit Plans” for additional information.

Except as otherwise indicated herein, all information in this prospectus, including the number of shares of common stock that will be outstandingafter this offering, assumes or gives effect to:

• the one-for-fifteen reverse stock split for our common stock effected in November 2018;

• the conversion of each share of our then-outstanding preferred stock to one share of our common stock effected in November 2018, or the ShareConversion;

• the filing and effectiveness of our amended and restated certificate of incorporation in Delaware and the adoption of our amended and restatedbylaws, each of which will be in effect upon the completion of this offering;

• no exercise of outstanding options or warrants described above subsequent to December 31, 2018 (other than as set forth below with respect tothe RSA Settlement and the Warrant Exercise);

• the issuance of 155,338 shares of our common stock immediately prior to the completion of this offering upon the Warrant Exercise;

• the issuance of 191,598 shares upon the RSA Settlement; and

• no exercise by the underwriters of their over-allotment option to purchase additional shares of our common stock from us and the sellingstockholder.

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SUMMARY CONSOLIDATED FINANCIAL DATA

The following table summary is our consolidated financial and other data should be read in conjunction with, and are qualified by reference to,“Management’s Discussion and Analysis of Financial Condition and Results of Operations” and the consolidated financial statements and notesthereto included elsewhere in this prospectus. The consolidated statement of income data for the years ended December 31, 2017 and 2018 and theconsolidated balance sheet data as of December 31, 2017 and 2018 are derived from, and qualified by reference to, our audited consolidated financialstatements included elsewhere in this prospectus and should be read in conjunction with those consolidated financial statements and notes thereto.

Year Ended December 31, 2017 2018 (in thousands, except per share data)

Statements of Income Data: Net revenues $ 59,031 $ 135,665 Cost of revenues 38,720 87,576

Gross profit 20,311 48,089 Operating expenses 27,081 42,695

Income (loss) from operations (6,770) 5,394 Interest expense (820) (1,828) Change in fair value of warrant liability (460) (970) Other expense, net (335) (565)

Income (loss) before income taxes (8,385) 2,031 Income tax expense (134) (754)

Net income (loss) (8,519) 1,277 Dividends on Series A, Series A-1 and Series A-2 preferred shares (6,836) (10,152)

Net loss attributable to common stockholders $ (15,355) $ (8,875)

Net loss per share attributable to common stockholders, basic and diluted(1) $ (14.96) $ (2.57)

Weighted average common stock outstanding 1,026,616 3,447,283

Other Data: Net cash provided by (used in) operating activities $ (8,906) $ 3,861 Net cash used in investing activities (999) (2,545) Net cash provided by financing activities 4,418 10,152 Adjusted EBITDA(2) (5,685) 6,931

(1) See Note 1 to our consolidated financial statements for an explanation of the method used to compute basic and diluted net loss per share.

(2) Adjusted EBITDA is defined by us as net income (loss), adjusted to exclude the impact of stock-based compensation expense, depreciation and amortization,

interest expense, net, income tax expense and change in fair value of warrant liability. Adjusted EBITDA is not a recognized term under U.S. GAAP and should notbe considered as an alternative to net income (loss) or other measures of financial performance or liquidity derived in accordance with U.S. GAAP.

We believe that Adjusted EBITDA provides useful information to investors about us and our financial condition and results of operations for the following reasons:(i) Adjusted EBITDA is a key measure used by our management team to evaluate our operating performance and make day-to-day operating decisions; and(ii) Adjusted EBITDA is frequently used by securities analysts, investors and other interested parties as a common performance measure to compare results orestimate valuations across companies in our industry.

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Adjusted EBITDA has limitations as an analytical tool, and you should not consider such measure either in isolation or as a substitute for net income (loss), cashflow or other methods of analyzing our results as reported under U.S. GAAP. Some of these limitations are: • Adjusted EBITDA does not reflect all cash expenditures, future requirements for capital expenditures or contractual commitments; • Adjusted EBITDA does not reflect changes in, or cash requirements for, working capital; • Adjusted EBITDA does not reflect interest expense on our debt or the cash requirements necessary to service interest or principal payments; and • other companies in our industry may define and/or calculate Adjusted EBITDA differently than we do, limiting its usefulness as a comparative measure.

Because of these limitations, Adjusted EBITDA should not be considered as discretionary cash available to us to reinvest in the growth of our business or as ameasure of cash that will be available to us to meet our obligations and accomplish our business plans. The following table provides a reconciliation of net income (loss), the most closely comparable U.S. GAAP financial measure, to Adjusted EBITDA:

Year Ended December 31, 2017 2018 (in thousands) Net income (loss) $ (8,519) $ 1,277

Depreciation and amortization 1,316 1,850 Stock-based compensation 104 252 Interest expense 820 1,828 Change in fair value of warrant liability (1) 460 970 Income tax expense 134 754

Adjusted EBITDA $ (5,685) $ 6,931

(1) Prior to the Share Conversion (including the conversion of preferred stock issuable upon exercise of warrants), the fair value of outstanding warrants to purchasepreferred stock was subject to periodic remeasurement, and any change in fair value was recognized as a change in fair value of warrant liability.

As of December 31, 2018

Actual Pro Forma (1) Pro Forma

As Adjusted (2) (in thousands)

Balance Sheet Data: Cash and cash equivalents $13,049 $ 13,072 $ 45,408 Working capital 15,668 13,583 45,919 Total assets 67,345 67,368 99,704 Total liabilities 62,216 64,323 64,323 Stockholders’ equity 5,129 3,045 35,381

(1) The pro forma data reflects (i) the issuance of 155,338 shares of our common stock immediately prior to the completion of this offering upon the Warrant Exerciseand (ii) in connection with the RSA Settlement, based upon the initial public offering price of $11.00 per share and estimated income tax obligations, (a) the netissuance of 191,598 shares of common stock, (b) stock-based compensation expense of approximately $4.2 million and (c) an increase to accrued and other currentliabilities and an equivalent decrease to additional paid-in capital of approximately $2.1 million to satisfy estimated tax withholding and remittance obligations asdescribed under the section titled “Use of Proceeds.”

(2) The pro forma as adjusted balance sheet data reflects (i) the pro forma adjustments set forth above and (ii) our receipt of net proceeds from the sale of 3,571,429

shares of common stock by us at the initial public offering price of $11.00 per share, after deducting underwriting discounts and commissions and estimated offeringexpenses payable by us.

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RISK FACTORS

Investing in our securities involves a great deal of risk. Careful consideration should be made of the following factors as well as other informationincluded in this prospectus before deciding to purchase our securities. There are many risks that affect our business and results of operations, some ofwhich are beyond our control. If any of the following risks actually occur, our business, financial condition or operating results could be significantlyharmed. This could cause the trading price of our common stock to decline, and you may lose all or part of your investment. Additional risks that we donot yet know of or that we currently think are immaterial may also affect our business and results of operations.

Risks Related to Our Business

We have not been profitable in recent years and may not achieve or maintain profitability in the future.

We have incurred significant net losses since 2013, including a net loss of $8.5 million in the year ended December 31, 2017. As of December 31, 2018,we had an accumulated deficit of $143.5 million. While we have experienced stronger revenue growth in recent periods, we are not certain whether orwhen we will obtain a high enough volume of sales of our products to sustain or increase our growth or achieve or maintain profitability in the future. Wealso expect our costs to increase in future periods, which could negatively impact our future operating results if our revenues do not increase. In particular,we expect to continue to expend substantial financial and other resources on:

• research and development related to our solutions, including investments in our engineering and technical teams;

• expansion of our sales and marketing efforts;

• general and administrative expenses, including legal and accounting expenses preparing for and related to being a public company; and

• continued expansion of our business.

These investments may not result in increased revenues or growth in our business. Additionally, we may encounter unforeseen operating expenses,difficulties, complications, delays and other unknown factors that may result in losses in future periods. If we are unable to increase our revenues at a ratesufficient to offset the expected increase in our costs, our business, operating results and financial position may be harmed, and we may not be able toachieve or maintain profitability over the long term.

We rely on our channel partners to generate a substantial majority of our revenues. If these channel partners fail to perform or if we cannot enter intoagreements with channel partners on favorable terms, our operating results could be significantly harmed.

A substantial majority of our revenues are generated through sales by our channel partners, which are primarily wireless carriers who sell our phonesthrough their sales channels. To the extent our channel partners are unsuccessful in selling or do not promote our products, or we are unable to obtain andretain a sufficient number of high-quality channel partners, our business and operating results could be significantly harmed.

We enter into master sales arrangements with the majority of our channel partners (including channel partners contributing over 90% of our total revenuesfor the year ended December 31, 2018) under which our partners purchase our products for distribution on a purchase order basis. While thesearrangements are typically long term, they generally do not contain any firm purchase volume commitments. As a result, our channel partners are notcontractually obligated to purchase from us any minimum number of products. We are generally required to satisfy any and all purchase orders deliveredto us within specified delivery windows, with limited exceptions (such as orders significantly in excess of forecasts). If we are unable to efficiently manageour supply and satisfy purchase orders on a timely basis to our channel partners, we may be in breach of our sales

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arrangements and lose potential sales. Our sales arrangements also generally include technical performance standards for our mobile phones andaccessories sold, which vary by channel partner. If a technical issue with any of our covered products exceeds certain preset failure thresholds for therelevant performance standard or standards, the channel partner typically has the right to cease selling the product, cancel open purchase orders and levycertain monetary penalties. If our products suffer technical issues or failures following sales to our channel partners, we may be subject to significantmonetary penalties and our channel partners may cease making purchase orders, which would significantly harm our business and results of operations. Inaddition, our channel partners retain sole discretion in which of their stocked products to offer their customers. While we may offer limited customerincentives, we generally have limited to no control over which products our channel partners decide to offer or promote, which directly impacts thenumber of products that our partners will purchase from us.

Our channel partners may be unsuccessful in marketing, selling and supporting our solutions. They may also market, sell and support solutions that arecompetitive with ours, and may devote more resources to the marketing, sales and support of such products. They may have incentives to promote ourcompetitors’ products in lieu of our products, particularly for our competitors with larger volumes of orders, more diverse product offerings and a longerrelationship with our channel partners. As a result, our channel partners may stop selling our products completely. While we employ a small direct salesforce, our channel partners have significantly larger sales teams who are not contractually obligated to promote any of our devices and often have multiplecompeting devices in stock to offer their customers. In addition, downstream sales by our channel partners often succeed due to attractive device prices andmonthly rate plans, which we do not control. In certain cases, we may promote our own devices through customer incentives, typically in exchange forretail price reductions or contributions of funds for marketing purposes; however, there can be no assurance that any such incentives would contribute toincreased purchases of our products. Further, given the impact of attractive pricing on ultimate sales, we generally must offer increased promotionalfunding or price reductions for our more expensive products. This promotional funding or price reductions operate to reduce our margins and significantlyimpact our profitability.

New sales channel partners may take several months or more to achieve significant sales. Our channel partner sales structure could subject us to lawsuits,potential liability and reputational harm if, for example, any of our channel partners misrepresents the functionality of our products or services to theircustomers, or violate laws or our corporate policies. Additionally, some of our master agreements with our wireless carrier customers contain most“favored nation” clauses. These clauses typically provide that if we enter into an agreement with another wireless carrier or customer on more favorableterms, we must offer some of those terms to our existing wireless carrier customers. These provisions may obligate us to provide different, more favorable,terms to our existing wireless carrier customers, which could, if applied, result in lower revenues or otherwise adversely impact our business, financialcondition and results of operations.

If we fail to effectively manage our existing or future sales channel partners, our channel partners fail to promote our products effectively, we are unable tomeet our obligations under our sales arrangements or future agreements that we may enter into with wireless carrier customers have terms that are morefavorable to the customer, our business and results of operations would be harmed.

We are materially dependent on the adoption of our solutions by both the industrial enterprise and public sector markets, and if end customers in thosemarkets do not purchase our solutions, our revenues will be adversely impacted, and we may not be able to expand into other markets.

Our revenues have been primarily in the industrial enterprise market, and we are materially dependent on the adoption of our solutions by both theindustrial enterprise and public sector markets. End customers in the public sector market may remain, for reasons outside our control, tied to LMRsolutions or other competitive alternatives to our phones. Sales of our products to these buyers may also be delayed or limited by these competitiveconditions. If our products are not widely accepted by buyers in those markets, we may not be able to expand sales of our products into new markets, andour business, results of operations and financial condition may be adversely impacted.

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We participate in a competitive industry, which may become more competitive. Competitors with greater resources and significant experience in high-volume product manufacturing may be able to respond more quickly and cost-effectively than we can to new or emerging technologies and changes incustomer requirements.

We face significant competition in developing and selling our solutions. Our primary competitors in the non-rugged mobile device market include AppleInc. and Samsung Electronics Co. Ltd. Our primary competitors in the rugged mobile device market include Bullitt Mobile Ltd. and Kyocera Corporation.We also face competition from large system integrators and manufacturers of private and public wireless network equipment and devices. Competitors inthis space include Harris Corporation, JVC KENWOOD Corporation, Motorola Solutions, Inc., or MSI, and Tait International Limited. For the DataCapture and RFID portion of our product offerings, competitors include companies that provide a broad portfolio of barcode scanning products that aresuitable for the majority of global market applications, such as Datalogic USA, Inc., Honeywell International Inc., Panasonic Corporation and ZebraTechnologies Corporation.

We cannot assure we will be able to compete successfully against current or future competitors. Increased competition in mobile computing platforms, datacapture products, or related accessories and software developments may result in price reductions, lower gross profit margins, and loss of market share,and could require increased spending on research and development, sales and marketing, and customer support. Some competitors may make strategicacquisitions or establish cooperative relationships with suppliers or companies that produce complementary products, which may create additionalpressures on our competitive position in the marketplace.

Most of our competitors have longer operating histories, greater name recognition, larger customer bases and significantly greater financial, technical,sales, marketing and other resources and experience than we do. In addition, because of the higher volume of components that many of our competitorspurchase from their suppliers, they are able to keep their supply costs relatively low and, as a result, may be able to recognize higher margins on theirproduct sales than we do. Many of our competitors may also have existing relationships with the channel partners who we use to sell our products, or withour potential customers. This competition may result in reduced prices, reduced margins and longer sales cycles for our products. Our competitors mayalso be able to more quickly and cost-effectively respond to new or emerging technologies and changes in customer requirements. The combination ofbrand strength, extensive distribution channels and financial resources of the larger vendors could cause us to lose market share and could reduce ourmargins on our products. If any of our larger competitors were to commit greater technical, sales, marketing and other resources to our markets, our abilityto compete would be adversely impacted. If we are unable to successfully compete with our competitors, our sales would suffer and as a result ourfinancial condition will be adversely impacted.

Defects in our products could reduce demand for our products and result in a loss of sales, delay in market acceptance and injury to our reputation,which would adversely impact our business.

Complex software, components and assemblies used in our products may contain undetected defects that are subsequently discovered at any point in thelife of the product. For example, in 2018, we recalled one batch of our XP8 devices from two wireless carriers due to manufacturing defects. Defects in ourproducts may result in a loss of sales, delay in market acceptance and injury to our reputation and increased warranty costs.

Additionally, our software may contain undetected errors, defects or bugs. Although we have not suffered significant harm from any errors, defects orbugs to date, we may discover significant errors, defects, or bugs in the future that we may not be able to correct or correct in a timely manner. It ispossible that errors, defects or bugs will be found in our existing or future software products and related services with the potential for delays in, or loss ofmarket acceptance of, our products and services, diversion of our resources, injury to our reputation, increased service and warranty expenses, andpayment of damages.

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Further, errors, defects or bugs in our solutions could be exploited by hackers or could otherwise result in an actual or perceived breach of our informationsystems. Alleviating any of these problems could require significant expense and could cause interruptions, delays or cessation of our product licensing,which would reduce demand for our products and result in a loss of sales, delay in market acceptance and injure our reputation and could adversely impactour business, results of operations and financial condition.

If our business does not grow as we expect, or if we fail to manage our growth effectively, our operating results and business would suffer.

Our ability to successfully grow our business depends on a number of factors including our ability to:

• accelerate the adoption of our solutions by new end customers;

• expand into new vertical markets;

• develop and deliver new products and services;

• increase awareness of the benefits that our solutions offer; and

• expand our international footprint.

As usage of our solutions grows, we will need to continue to make investments to develop and implement new or updated solutions, technologies, securityfeatures and cloud-based infrastructure operations. In addition, we will need to appropriately scale our internal business systems and our servicesorganization, including the suppliers of our detection equipment and customer support services, to serve our growing customer base. Any failure of, ordelay in, these efforts could impair the performance of our solutions and reduce customer satisfaction.

Further, our growth could increase quickly and place a strain on our managerial, operational, financial and other resources, and our future operating resultsdepend to a large extent on our ability to successfully manage our anticipated expansion and growth. To manage our growth successfully, we will need tocontinue to invest in sales and marketing, research and development, and general and administrative functions and other areas. We are likely to recognizethe costs associated with these investments earlier than receiving some of the anticipated benefits, and the return on these investments may be lower, ormay develop more slowly, than we expect, which could adversely impact our operating results.

If we are unable to manage our growth effectively, we may not be able to take advantage of market opportunities or develop new solutions or upgrades toour existing solutions, satisfy customer requirements, maintain the quality and security of our solutions or execute on our business plan, any of which couldharm our business, operating results and financial condition.

We are required to undergo a lengthy customization and certification process for each wireless carrier customer, which increases our operatingexpenses, and failure to obtain such certification would adversely impact our results of operations and financial condition.

Each wireless carrier requires each of our devices to complete a thorough technical acceptance process before it can be stocked and sold. Such acceptanceprocesses impose rigorous and complex requirements on our devices, which result in a lengthy testing and certification process, during which we incursubstantial operating expenses related to the wireless carrier’s technical acceptance of our devices. The acceptance processes and related costs to us varyacross carrier customers depending on carrier size and level of customization required. During the two year period ended December 31, 2018, we incurredbetween $0.2 million and $1.1 million in operating expenses related to customization costs and between $0.4 million and $1.7 million in operatingexpenses related to certification and acceptance costs per device for our five largest wireless carrier customers. Generally, the certification processcommences within one to three months of product concept development. During this development stage, certain carriers provide a technology roadmapand target demographics, allowing us to

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define product specifications to meet carrier goals, while other carriers provide defined specifications and preferred price points. Once we receive approvalof a product concept by the carrier, we and the carrier advance the product to the development stage. When the product is close to being a functioningmodel, we commence internal quality assurance processes and field testing, which may include third-party lab testing, in-market field testing andinteroperability testing. Finally, as the last step in the testing phase, the wireless carrier typically conducts testing itself, following which the product maybe certified and stocked. The entire process can last from six to 18 months depending on the particular wireless carrier and type of device. Any delay in theacceptance process or failure to satisfy the device certification requirements would affect our ability to bring products to market and adversely impacts ourresults of operations and financial condition.

If we fail to adequately forecast demand for our inventory and supply needs, we could incur additional costs or experience manufacturing delays,which could reduce our gross margin or cause us to delay or even lose sales.

Because our production volumes are based on a forecast of channel partner demand rather than purchase commitments from our major customers, there isa risk that our forecasts could be inaccurate and that we will be unable to sell our products at the volumes and prices we expect, which may result in excessinventory. We provide, and will continue to provide, forecasts of our demand to our third-party suppliers prior to the scheduled delivery of products to ourchannel partners. If we overestimate our requirements, our contract manufacturers may have excess component inventory, which could increase our costs.If we underestimate our requirements, our contract manufacturers may have inadequate component inventory, which could interrupt the manufacturing ofour products and result in delays in shipments and revenues or even lost sales, or could incur unplanned overtime costs to meet our requirements, resultingin significant cost increases. For example, certain materials and components used to manufacture our products may reach end of life during any of ourproduct’s life cycles, following which suppliers no longer provide such expired materials and components. This would require us to either source andqualify an alternative component, which could require a re-certification of the device by the wireless carriers and/or regulatory agencies, or forecastproduct demand for a final purchase of such materials and components that may reach end of life to ensure that we have sufficient product inventorythrough a product’s life cycle. If we overestimate forecasted demand, we would hold excess end-of-life materials and components resulting in increasedcosts. If we underestimate forecasted demand, we could experience delays in shipments and loss of revenues.

In addition, if we underestimate our requirements and the applicable supplier becomes insolvent or is no longer able to timely supply our needs in a cost-efficient manner or at all, we may be required to acquire components, which may need to be customized for our products, from alternative suppliers,including at significantly higher costs. For example, in 2018, one of our suppliers became insolvent and ceased all production, requiring us to seekalternative supply of complex components in a very short time frame. If we cannot source alternative suppliers and/or alternative components, we maysuffer delays in shipments or lost sales. Similarly, credit constraints at our suppliers could require us to accelerate payment of our accounts payable,impacting our cash flow. Further, lead times for materials and components that we order vary significantly and depend on factors such as the specificsupplier, contract terms, customization needed for any particular component and demand for each component at a given time. Any such failure toaccurately forecast demand and manufacturing and supply requirements, and any need to obtain alternative supply sources, could materially harm ourbusiness, results of operations and financial condition.

We may not be able to continue to develop solutions to address user needs effectively in an industry characterized by ongoing change and rapidtechnological advances.

To be successful, we must adapt to rapidly changing technological and application needs by continually improving our products, as well as introducingnew products and services, to address user demands.

Our industry is characterized by:

• evolving industry standards;

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• frequent new product and service introductions;

• evolving distribution channels;

• increasing demand for customized product and software solutions;

• rapid competitive developments; and

• changing customer demands.

Future success will depend on our ability to effectively and economically adapt in this evolving environment. We could incur substantial costs if we mustmodify our business to adapt to these changes, and may even be unable to adapt to these changes.

In 2017 and 2018, approximately 76% and 80% of our revenues, respectively, were derived from our top five customers. We expect our revenues tocontinue to be heavily concentrated among our top customers, and the loss of, or significant reduction in orders from, any of these customers couldsignificantly reduce our revenues and adversely impact our operating results.

Historically, our revenues have been concentrated among a very small number of customers. In fiscal year 2017 and 2018, our top five wireless carrierscustomers accounted for approximately 76% and 80% of our revenues, respectively. In 2018, three of the four largest U.S. wireless carriers, and the threelargest Canadian wireless carriers, began stocking our entire next generation product portfolio for the first time in our history following their certificationof our products, resulting in significant revenue concentration among these few carriers. In addition to the certification and stocking of our products bythese wireless carriers, revenue increased among such wireless carriers as a result of increases in awareness of our brand among end users and endcustomers over the past several years, new product launches and an increased focus by carriers such as AT&T and Verizon on dedicated public safetynetworks, including FirstNet. We expect our revenues to remain heavily concentrated among these top wireless carriers, and we will be substantiallydependent on these wireless carriers continuing to purchase and promote our products to their sales channels as well as customer demand for devices andservices from these wireless carriers (factors over which we do not have any control). The loss of one or more of these significant customers, or reduceddemand or purchases from these significant customers, would result in significant harm to our revenues and results of operation, and our growth could belimited.

The markets for our devices and related accessories may not develop as quickly as we expect, or may not develop at all.

Our future success is substantially dependent upon continued adoption of devices and related accessories in the industrial enterprise and public sectormarkets, including the transition from LMR and PTT, to smartphone and LTE networks. These market developments and transitions may take longer thanwe expect or may not occur at all, and may not be as widespread as we expect. If the market does not develop as we expect, our business, operating resultsand financial condition would be significantly harmed.

Our dependence on third-party suppliers for key components of our products could delay shipment of our products and reduce our sales.

We depend on certain suppliers for the delivery of components used in the assembly of our products, including machined parts, injection molded plasticparts, printed circuit boards and other miscellaneous custom parts for our products. Our reliance on third-party suppliers creates risks related to ourpotential inability to obtain an adequate supply of components and reduced control over pricing and timing of delivery of components. In particular, wehave little to no control over the prices at which our suppliers sell materials and components to us. Certain supplies of our components are available onlyfrom a single source or limited sources and we may not be able to diversify sources in a timely manner. We have experienced shortages in the past thathave negatively impacted our results of operations and may experience such shortages in the future. For example, in 2018, we experienced a shortage insupply of a camera part from one of our suppliers for our XP8 phone, which resulted in delays in delivery of completed XP8 phones to certain of ourchannel partners.

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We also do not have long-term supply agreements with any of our suppliers. Our current contracts with certain suppliers may be canceled or not extendedby such suppliers and, therefore, do not afford us with sufficient protection against a reduction or interruption in supplies. Moreover, in the event any ofthese suppliers breach their contracts with us, our legal remedies associated with such a breach may be insufficient to compensate us for any damages wemay suffer.

Any interruption of supply for any material components of our products, or inability to obtain required components from our third-party suppliers, couldsignificantly delay the production and shipment of our products and harm our revenues, profitability and financial condition.

Our future success is dependent on our ability to create independent brand awareness for our company and products with end customers, and ourinability to achieve such brand awareness could limit our prospects.

We depend on a small number of wireless carriers to distribute our products. While we intend to ramp up direct marketing and end-customer brandawareness initiatives in the future, our sales and marketing efforts have historically been predominantly focused on channel partners. As such, ouroperating expenses related to end-customer marketing efforts have historically been very small, representing less than 1.0% of our total sales andmarketing expenses during fiscal year 2018. To increase end-customer brand awareness, we intend to develop sales tools for key verticals within are targetmarkets, increase usage of social media and expand product training efforts, among other things. As a result, we expect our sales and marketing expensesto increase in the future, primarily from increased sales personnel expenses, which will require us to cost-efficiently ramp up our sales and marketingcapabilities and effectively target end customers. However, there can be no assurance that we will successfully increase our brand awareness or do so in acost-efficient manner while maintaining market share within our existing sales channels. Our failure to establish stand-alone brand awareness with endcustomers of our products will leave us vulnerable to the marketing and selling success of others, including our channel partners, and these developmentscould have an adverse impact on our prospects. If we are unable to significantly increase the awareness of our brand and solutions with end customers in acost-efficient manner, we will remain significantly dependent on our channel partners for sales of our products, and our business, financial condition andresults of operations could be adversely impacted.

We are dependent on the continued services and performance of a concentrated group of senior management and other key personnel, the loss of anyof whom could adversely impact our business.

Our future success depends in large part on the continued contributions of a concentrated group of senior management and other key personnel. Inparticular, the leadership of key management personnel is critical to the successful management of our company, the development of our solutions and ourstrategic direction. We also depend on the contributions of key technical personnel.

We maintain “key person” insurance only for our Chief Executive Officer and do not maintain such insurance for any other member of our seniormanagement team or any of our other key employees. Our senior management and key personnel are all employed on an at-will basis, which means thatthey could terminate their employment with us at any time, for any reason and without notice. The loss of any of our key personnel could significantlydelay or prevent the achievement of our development and strategic objectives and harm our business.

We compete in a rapidly evolving market, and the failure to respond quickly and effectively to changing market requirements could cause our businessand operating results to decline.

The mobile device market is characterized by rapidly changing technology, changing customer needs, evolving industry standards and frequentintroductions of new products and services. In order to deliver a competitive mobile device, our solutions must be capable of operating in an increasinglycomplex network environment. As new wireless phones are introduced and standards in the mobile device market evolve, we may be required to modifyour phones and services to make them compatible with these new products and standards. Likewise, if

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our competitors introduce new devices and services that compete with ours, we may be required to reposition our solutions or introduce new phones andsolutions in response to such competitive pressure. We may not be successful in modifying our current phones or introducing new ones in a timely orappropriately responsive manner, or at all. If we fail to address these changes successfully, our business and operating results could be significantlyharmed.

If dedicated public safety LTE networks are not deployed at the rate we anticipate or at all, demand for our solutions may not grow as expected.

A key part of our strategy is to further expand the use of our solutions over dedicated LTE networks in the public safety market. If the deployment ofdedicated LTE networks is delayed or such networks are not adopted at the rate we anticipate, demand for our solutions may not develop as we anticipate,which would have a negative effect on our revenues.

If we are unable to sell our solutions into new markets, our revenues may not grow.

Any new market into which we attempt to sell our solutions may not be receptive. Our ability to penetrate new markets depends on the quality of oursolutions, the continued adoption of our public safety solution by first responders, the perceived value of our solutions as a risk management tool and ourability to design our solutions to meet the demands of our customers. If the markets for our solutions do not develop as we expect, our revenues may notgrow.

Our ability to successfully face these challenges depends on several factors, including increasing the awareness of our solutions and their benefits, theeffectiveness of our marketing programs, the costs of our solutions, our ability to attract, retain and effectively train sales and marketing personnel, and ourability to develop relationships with wireless carriers and other partners. If we are unsuccessful in developing and marketing our solutions into newmarkets, new markets for our solutions might not develop or might develop more slowly than we expect, either of which would harm our revenues andgrowth prospects.

If we are unable to attract, integrate and retain additional qualified personnel, including top technical talent, our business could be adverselyimpacted.

Our future success depends in part on our ability to identify, attract, integrate and retain highly skilled technical, managerial, sales and other personnel. Weface intense competition for qualified individuals from numerous other companies, including other software and technology companies, many of whomhave greater financial and other resources than we do. Some of these characteristics may be more appealing to high-quality candidates than those we haveto offer. In addition, new hires often require significant training and, in many cases, take significant time before they achieve full productivity. We mayincur significant costs to attract and retain qualified personnel, including significant expenditures related to salaries and benefits and compensationexpenses related to equity awards, and we may lose new employees to our competitors or other companies before we realize the benefit of our investmentin recruiting and training them. Moreover, new employees may not be or become as productive as we expect, as we may face challenges in adequately orappropriately integrating them into our workforce and culture. If we are unable to attract, integrate and retain suitably qualified individuals who arecapable of meeting our growing technical, operational and managerial requirements on a timely basis or at all, our business will be adversely impacted.

Volatility or lack of positive performance in our stock price may also affect our ability to attract and retain our key employees. Many of our seniormanagement personnel and other key employees have become, or will soon become, vested in a substantial amount of stock or stock options. Employeesmay be more likely to leave us if the shares they own or the shares underlying their vested options have significantly appreciated in value relative to theoriginal purchase prices of the shares or the exercise prices of the options, or, conversely, if the exercise prices of the options that they hold aresignificantly above the market price of our common stock. If we are unable to appropriately incentivize and retain our employees through equitycompensation, or if we need to increase our compensation expenses in order to appropriately incentivize and retain our employees, our business, operatingresults and financial condition would be adversely impacted.

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Our existing IT systems may not be adequate to manage our growth, and our implementation of updated IT systems could result in significantdisruptions to our operations.

Our existing IT systems may be inadequate to manage our growth, and we are planning to implement various upgrades to our enterprise resource planning,or ERP, systems, as well as other complementary IT systems, over the next several years. Implementation of these solutions and systems is highlydependent on coordination of numerous software and system providers and internal business teams. The interdependence of these solutions and systems isa significant risk to the successful completion of the initiatives and the failure of any one system could have a significant adverse impact on theimplementation of our overall IT infrastructure. We may experience difficulties as we transition to these new or upgraded systems and processes, includingloss or corruption of data, delayed shipments, decreases in productivity as our personnel and third-party providers implement and become familiar withnew systems, increased costs and lost revenues.

In addition, transitioning to these new systems requires significant capital investments and personnel resources. Difficulties in implementing new orupgraded information systems or significant system failures could disrupt our operations and have a significant adverse impact on our capital resources,financial condition, results of operations or cash flows. Implementation of this new IT infrastructure has a significant impact on our business processes andinformation systems across a significant portion of our operations. As a result, we will be undergoing significant changes in our operational processes andinternal controls as our implementation progresses, which in turn will require significant change management, including recruiting and training of qualifiedpersonnel. If we are unable to successfully manage these changes as we implement these systems, including harmonizing our systems, data, processes andreporting analytics, our ability to conduct, manage and control routine business functions could be negatively affected and significant disruptions to ourbusiness could occur. In addition, we could incur material unanticipated expenses, including additional costs of implementation or costs of conductingbusiness. These risks could result in significant business disruptions or divert management’s attention from key strategic initiatives and have a significantadverse impact on our capital resources, financial condition and results of operations.

The application development ecosystem supporting our devices and related accessories is new and evolving.

The application development ecosystem supporting our devices and related accessories is new and evolving. Specifically, the number of applicationdevelopers in the ecosystem supporting our devices and accessories is small. If the market or the application development ecosystem does not develop,timely or at all, demand for our products may be limited, and our business and results of operations will be significantly harmed.

Our business is difficult to evaluate because we have a limited operating history in our markets.

We have a limited operating history based on which you can evaluate our present business and future prospects. For example, in March 2018, we launchedour XP5s and XP8 phones in the public safety market and also have limited operating history in the industrial enterprise market. Because of this limitedoperating history, we face challenges in predicting our business and evaluating its prospects. These challenges present risks and uncertainties relating toour ability to implement our business plan successfully. Our prospects must be considered in light of the risks, expenses and difficulties frequentlyencountered by newly-public companies that have recently launched a new product into a new market. If we are unsuccessful in addressing these risks anduncertainties, our business, results of operations and financial condition will be significantly harmed.

The impact of potential changes in customs, tariffs, and trade policies in the United States and the potential corresponding actions by other countries,including recent trade initiatives announced by the U.S. presidential administration against China, in which we do business could adversely impactour financial performance.

The U.S. government has made proposals that are intended to address trade imbalances, which include encouraging increased production in the UnitedStates. These proposals could result in increased customs duties

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and tariffs, and the renegotiation of some U.S. trade agreements. We import a significant percentage of our products into the United States, and anincrease in customs duties and tariffs with respect to these imports could negatively impact our financial performance. If such customs duties and tariffsare implemented, it also may cause U.S. trading partners to take actions with respect to U.S. imports or U.S. investment activities in their respectivecountries. Any potential changes in trade policies in the United States and the potential corresponding actions by other countries in which we do businesscould adversely impact our financial performance. Given the level of uncertainty over which provisions will be enacted, we cannot predict with certaintythe impact of the proposals.

For example, in 2018, the U.S. presidential administration and Chinese government imposed significant tariffs on exports between the two countries. Thisevolving policy dispute between China and the United States is likely to have significant impact on the industries in which we participate, directly andindirectly, and no assurance can be given that any individual customer or significant groups of companies or a particular industry, will not be adverselyimpacted by any governmental actions taken by either China or the United States. In addition, we manufacture our mobile phones at our facility inShenzhen, China, which could result in significant additional costs to us when shipping our products to various customers in the United Stat