# 50 leading Telecommunications companies in California

Tamtam tracks 105 Telecommunications companies headquartered in California. This list ranks the 50 largest by number of employees on LinkedIn, led by Viasat, Poly and Pearce Services. Their median headcount is 493. Half of them were founded in 1999 or later. The most common headquarters are San Jose (8), Costa Mesa (3) and Los Angeles (3).

These California-based telecommunications companies are primarily mid-sized to large firms, with a focus on connectivity solutions, network infrastructure, and communication technologies. Companies like Viasat offer global connectivity for diverse sectors, while Pearce Services specializes in critical infrastructure maintenance. Poly provides premium audio and video products, and Sonic is a prominent ISP known for customer care.

Several companies, including Polycom, Infinera, Harmonic, and UTStarcom, are headquartered in San Jose, indicating a concentration of telecommunications expertise in the Silicon Valley area. This geographic clustering suggests a shared ecosystem for innovation and development in telecommunications solutions.

🇺🇸 California · 50 companies · Updated Nov 12, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Viasat](https://www.tamtam.ai/c/viasat) (viasat.com)<br>Global communications company providing connectivity solutions for consumers, businesses, governments, and militaries worldwide, ensuring internet access in remote locations and on-the-go | Telecommunications | 🇺🇸 Carlsbad | 6,809 | 1986 |
| 2 | [Poly](https://www.tamtam.ai/c/poly) (poly.com)<br>This company provides premium audio and video products as part of HP's hybrid work solutions for optimal meetings anytime, anywhere | Telecommunications | 🇺🇸 Santa Cruz | 3,136 |  |
| 3 | [Pearce Services](https://www.tamtam.ai/c/pearce-services) (pearce-services.com)<br>Provider of repair, maintenance, and engineering services for critical infrastructure in renewable energy, power generation, and telecom industries, with tech-enabled solutions nationwide | Telecommunications | 🇺🇸 Paso Robles | 2,961 |  |
| 4 | [Sonic](https://www.tamtam.ai/c/sonic-santa-rosa) (sonic.com)<br>A leading ISP in California providing fast, reliable internet and phone service for businesses and homes since 1994 Known for prioritizing customer care and online privacy rights | Telecommunications | 🇺🇸 Santa Rosa | 2,751 | 1994 |
| 5 | [Polycom](https://www.tamtam.ai/c/polycom) (hp.com)<br>Poly offers a range of smart communication endpoints, cloud software, and services to facilitate authentic human connection and collaboration | Telecommunications | 🇺🇸 San Jose | 2,008 | 1990 |
| 6 | [Mobileum](https://www.tamtam.ai/c/mobileum) (mobileum.com)<br>A leading provider of telecom analytics and testing solutions for roaming, security, risk management to increase revenues, improve network security, and reduce costs | Telecommunications | 🇺🇸 Cupertino | 1,970 |  |
| 7 | [Infinera](https://www.tamtam.ai/c/infinera) (nokia.com)<br>Revolutionizing telecommunications networks worldwide with innovative connectivity solutions, advanced optical technology, automation software, and professional services for global customers | Telecommunications | 🇺🇸 San Jose | 1,960 | 2000 |
| 8 | [Spirent Communications](https://www.tamtam.ai/c/spirent-communications) (spirent.com)<br>Provide innovative testing, assurance, and automation solutions for wireless, positioning, 5G, cloud, and autonomous vehicle technologies. | Telecommunications | 🇺🇸 Santa Clara | 1,755 | 1936 |
| 9 | [Finisar Corporation](https://www.tamtam.ai/c/finisar-corporation) (coherent.com)<br>Follow us at the provided link for updates and information about our rebranding as Coherent Corp Exciting changes ahead! | Telecommunications | 🇺🇸 Sunnyvale | 1,709 |  |
| 10 | [Harmonic](https://www.tamtam.ai/c/harmonic) (harmonicinc.com)<br>Industry leader in video, broadband, and media solutions Specializing in cloud streaming, software as a service, and enabling content delivery to all screens | Telecommunications | 🇺🇸 San Jose | 1,612 |  |
| 11 | [UTStarcom](https://www.tamtam.ai/c/utstarcom) (utstar.com)<br>A telecommunications solutions company providing cutting-edge packet optical transport, broadband access, and Software Defined Networking platform to simplify network operations and boost efficiency | Telecommunications | 🇺🇸 San Jose | 1,252 |  |
| 12 | [Plantronics](https://www.tamtam.ai/c/plantronics) (hp.com)<br>A global leader in audio communications, specializing in simple and clear communication solutions for business and consumers, promoting distraction-free environments | Telecommunications | 🇺🇸 Santa Cruz | 1,070 | 1961 |
| 13 | [Webex](https://www.tamtam.ai/c/webex) (webex.com)<br>cloud-based collaboration solutions including video meetings, calling, messaging, events, customer experience, AI-driven, secure, integrated with business apps | Telecommunications | 🇺🇸 San Jose | 965 |  |
| 14 | [Kyocera Mobile](https://www.tamtam.ai/c/kyocera-mobile) (kyoceramobile.com)<br>A leader in rugged mobility solutions, specializing in waterproof and durable mobile devices with enterprise-grade security and white glove services for business customers | Telecommunications | 🇺🇸 San Diego | 924 | 2000 |
| 15 | [Anuvu](https://www.tamtam.ai/c/anuvu) (anuvu.com)<br>The company offers technology solutions for entertainment and connectivity in mobility markets, catering to passengers' ever-changing needs with reliable, scalable, and affordable services | Telecommunications | 🇺🇸 Santa Ana | 916 |  |
| 16 | [Breezeline](https://www.tamtam.ai/c/breezeline) (breezeline.com)<br>A socially responsible company offering Internet, TV, and Voice services with a focus on exceptional customer service and promoting diversity | Telecommunications | 🇺🇸 Quincy | 885 |  |
| 17 | [Telecom Technology Services, Inc.](https://www.tamtam.ai/c/telecom-technology-services-inc) (linkedin.com)<br>Specializing in accelerating 5G network rollouts, this company automates and streamlines processes for vRAN, Open RAN, Fiber, and IoT deployment | Telecommunications | 🇺🇸 Pleasanton | 684 | 1997 |
| 18 | [Ooma, Inc.](https://www.tamtam.ai/c/ooma-inc) (ooma.com)<br>The company creates innovative communications solutions for businesses and consumers, offering cloud-based telephony, home security, HD voice quality, mobile integration, and smart connected devices | Telecommunications | 🇺🇸 Sunnyvale | 652 | 2003 |
| 19 | [TelePacific Communications (TPx Communications)](https://www.tamtam.ai/c/telepacific-communications-tpx-communications) (tpx.com)<br>TelePacific company is now TPx Communications, providing news and updates on their services Visit their LinkedIn page for more information | Telecommunications | 🇺🇸 Los Angeles | 616 | 1998 |
| 20 | [OCLARO](https://www.tamtam.ai/c/oclaro) (lumentum.com)<br>A photonics company offering a best-in-class portfolio, now part of Lumentum Follow them for more information on their products | Telecommunications | 🇺🇸 San Jose | 606 | 2009 |
| 21 | [CHi](https://www.tamtam.ai/c/chi) (crouching-hippo.com)<br>Specializes in providing customized software solutions for wireless telecoms industry, focusing on driving value from drive test data for big operators and equipment vendors worldwide | Telecommunications | 🇺🇸 Alameda | 584 | 2009 |
| 22 | [Metro Pcs Authorized Dealer](https://www.tamtam.ai/c/metro-pcs-authorized-dealer) (metrobyt-mobile.com)<br>A telecommunications company in Tracy, California, specializing in Metro PCS services and products | Telecommunications | 🇺🇸 Tracy | 523 |  |
| 23 | [Tarana Wireless](https://www.tamtam.ai/c/tarana-wireless) (taranawireless.com)<br>Innovative technology company accelerating global internet access deployment with next-generation fixed wireless technology for affordable high-speed connectivity | Telecommunications | 🇺🇸 Milpitas | 517 | 2009 |
| 24 | [Ansafone Contact Centers](https://www.tamtam.ai/c/ansafone-contact-centers) (ansafone.com)<br>Leading contact center with omni-channel services for US and Canadian companies, offering inbound/outbound call platforms, live chat, email, social media management, and CRM solutions | Telecommunications | 🇺🇸 Santa Ana | 497 | 1970 |
| 25 | [BORQS](https://www.tamtam.ai/c/borqs) (borqs.com)<br>Global leader in IoT solutions, offering customizable Android-based devices and E2E cloud services Specializing in connected solutions and MVNO services with key partnerships and industry recognition | Telecommunications | 🇺🇸 Suite 320 Santa Clara | 493 | 2007 |
| 26 | [Plume](https://www.tamtam.ai/c/plume) (plume.com)<br>Cloud-managed Wi-Fi platform offering AI-driven optimization, security, smart home services, and analytics to improve ISP customer experiences. | Telecommunications | 🇺🇸 Palo Alto | 474 | 2015 |
| 27 | [Source Photonics](https://www.tamtam.ai/c/source-photonics) (sourcephotonics.com)<br>Innovative global provider of technology for communications, data connectivity, FTTx networks, wireless connectivity, and data centers with a focus on quality and customer satisfaction | Telecommunications | 🇺🇸 West Hills | 447 | 1988 |
| 28 | [TruConnect](https://www.tamtam.ai/c/truconnect) (truconnect.com)<br>TruConnect offers affordable prepaid and Lifeline wireless services nationwide, simplifying communication and providing flexibility to customers | Telecommunications | 🇺🇸 Los Angeles | 433 | 2011 |
| 29 | [Marketing Solutions SRE](https://www.tamtam.ai/c/marketing-solutions-sre) (linkedin.com)<br>The company provides marketing solutions with a focus on generating revenue Their slogan emphasizes the importance of making money | Telecommunications | 🇺🇸 Mountain View | 433 | 2019 |
| 30 | [Coolpad](https://www.tamtam.ai/c/coolpad) (coolpad.com)<br>Global mobile device brand focused on affordable, reliable products with user-centric innovation Offering cost-efficient, powerful, and stylish technology backed by AI | Telecommunications | 🇺🇸 Irvine | 428 | 1993 |
| 31 | [DASAN Zhone Solutions](https://www.tamtam.ai/c/dasan-zhone-solutions) (dasanzhone.com)<br>Global leader in network access solutions for service provider and enterprise networks, offering broadband access, Ethernet switching, Passive Optical LAN, and software-defined networks worldwide | Telecommunications | 🇺🇸 Oakland | 420 | 1999 |
| 32 | [Inseego Corp](https://www.tamtam.ai/c/inseego-corp) (inseego.com)<br>Industry pioneer in smart device-to-cloud solutions, extending 5G network edge for broader coverage, high-speed data, low latency, and secure internet access worldwide | Telecommunications | 🇺🇸 San Diego | 413 | 1996 |
| 33 | [TeleDirect Call Centers](https://www.tamtam.ai/c/teledirect-call-centers) (teledirect.com)<br>TeleDirect offers on-demand contact center solutions with online tools for scripting, reporting, and lead delivery, along with consultation and services for call centers | Telecommunications | 🇺🇸 Sacramento | 376 | 1961 |
| 34 | [NeoPhotonics](https://www.tamtam.ai/c/neophotonics) (lumentum.com)<br>Specializing in accelerating optical network speed and scalability through the acquisition of NeoPhotonics products and updates under their new handle | Telecommunications | 🇺🇸 San Jose | 375 |  |
| 35 | [Mint Mobile](https://www.tamtam.ai/c/mint-mobile) (careers.t-mobile.com)<br>Provides nationwide premium wireless service at low prices by eliminating overhead and passing savings directly to customers with innovation. | Telecommunications | 🇺🇸 Costa Mesa | 355 | 2016 |
| 36 | [Aurora Networks](https://www.tamtam.ai/c/aurora-networks) (commscope.com)<br>Innovator of advanced optical transport and access systems for broadband networks, enabling providers to deliver capacity, flexibility, and high-capacity services | Telecommunications | 🇺🇸 San Jose | 353 | 1999 |
| 37 | [Faurecia](https://www.tamtam.ai/c/faurecia-el-cerrito) (intentionis.com)<br>A technology company founded in Silicon Valley in 2009, connecting devices to the cloud via intelligent software for optimized sensor traffic and privacy management | Telecommunications | 🇺🇸 El Cerrito | 349 | 2009 |
| 38 | [ITC Service Group](https://www.tamtam.ai/c/itc-service-group) (callitc.com)<br>Provider of qualified personnel and managed services for planning, design, construction, and maintenance of wireless and wireline communications networks globally | Telecommunications | 🇺🇸 Citrus Heights | 331 | 1999 |
| 39 | [Silvus Technologies](https://www.tamtam.ai/c/silvus-technologies) (silvustechnologies.com)<br>Silvus Technologies develops advanced communication technologies reshaping tactical wireless communications with Mobile Networked MIMO technology for reliable connectivity in challenging environments | Telecommunications | 🇺🇸 Los Angeles | 325 | 2004 |
| 40 | [Flash Mobile](https://www.tamtam.ai/c/flash-mobile)<br>A telecommunications company based in Santa Ana, California, specialized in mobile services and products | Telecommunications | 🇺🇸 Santa Ana | 324 |  |
| 41 | [Speakeasy](https://www.tamtam.ai/c/speakeasy) (speakeasy.net)<br>A company formed in 2010 through the merger of three companies, offering nationwide IP voice, security, VPN, and Internet services Acquired in 2018 | Telecommunications | 🇺🇸 Costa Mesa | 323 | 1996 |
| 42 | [HP Communications, Inc.](https://www.tamtam.ai/c/hp-communications-inc) (hpcomminc.com)<br>A full turnkey OSP/ISP contractor with over 20 years of experience, providing cutting-edge communication solutions and excellent customer service nationwide | Telecommunications | 🇺🇸 Corona | 320 | 1998 |
| 43 | [APWireless Infrastructure Partners, LLC](https://www.tamtam.ai/c/apwireless-infrastructure-partners-llc) (apwip.com)<br>Global telecom and digital infrastructure investment company acquiring and managing critical telecom infrastructure like cell site leases, fiber, DAS, and data centers Building towers worldwide | Telecommunications | 🇺🇸 San Diego | 316 | 2010 |
| 44 | [Ultra Mobile](https://www.tamtam.ai/c/ultra-mobile) (ultra.me)<br>wireless telecom company offering nationwide and global calling services with focus on technology, product improvement, and customer experience | Telecommunications | 🇺🇸 Costa Mesa | 312 | 2011 |
| 45 | [Halo](https://www.tamtam.ai/c/halo) (halotechnology.com)<br>A global leader in fiber optics, Halo shapes the future with compatible transceiver technology, offering innovative product solutions through its leading global brands | Telecommunications | 🇺🇸 Tustin | 307 |  |
| 46 | [Futurewei Technologies, Inc.](https://www.tamtam.ai/c/futurewei-technologies-inc) (futurewei.com)<br>A technology company founded in 2001 that focuses on open innovation, collaboration with companies worldwide, engagement in standard programs, and building open ecosystems | Telecommunications | 🇺🇸 Santa Clara | 307 | 2001 |
| 47 | [Skylite Corporation](https://www.tamtam.ai/c/skylite-corporation) (skylite.com)<br>A trusted seller of Ethernet cables since 1996, offering Cat5e/Cat6 cables at competitive prices with free shipping Also provides various low voltage cables | Telecommunications | 🇺🇸 Fremont | 303 | 1994 |
| 48 | [Viasat Energy Services](https://www.tamtam.ai/c/viasat-energy-services) (viasat.com)<br>A trusted partner for energy industries, providing connectivity, security, and intelligence from distributed sites and assets worldwide Visit energyviasatcom for more information | Telecommunications | 🇺🇸 Carlsbad | 252 | 2001 |
| 49 | [Orange Liberia](https://www.tamtam.ai/c/orange-liberia) (orange.com.lr)<br>Leading provider of telecommunications services in Liberia, offering a wide range of communication solutions to meet the needs of customers | Telecommunications | 🇺🇸 Monrovia | 246 |  |
| 50 | [Oplink Communications, LLC](https://www.tamtam.ai/c/oplink-communications-llc) (molex.com)<br>A provider of optical communication components, modules, and subsystems offering advanced solutions in DWDM, CWDM, optical amplification, switching, connectivity, and transceivers globally | Telecommunications | 🇺🇸 Fremont | 244 |  |

## How this list is built

Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 12, 2026.

## More company lists in California

- [The largest companies in California](https://www.tamtam.ai/l/largest-companies-california) (15,264)
- [Multinational companies in California](https://www.tamtam.ai/l/multinational-companies-california) (2,591)
- [SaaS companies in California](https://www.tamtam.ai/l/saas-companies-california) (1,854)
- [Software Development companies in California](https://www.tamtam.ai/l/software-development-companies-california) (1,649)
- [AI companies in California](https://www.tamtam.ai/l/ai-companies-california) (1,296)
- [Companies with in-house R&D in California](https://www.tamtam.ai/l/r-and-d-companies-california) (1,275)
- [Manufacturers in California](https://www.tamtam.ai/l/manufacturers-california) (1,066)
- [Hardware manufacturers in California](https://www.tamtam.ai/l/hardware-companies-california) (985)
- [IT Services and IT Consulting companies in California](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-california) (968)
- [Education providers in California](https://www.tamtam.ai/l/education-companies-california-united-states) (950)
- [Subscription businesses in California](https://www.tamtam.ai/l/subscription-businesses-california) (939)
- [Venture capital and private equity firms in California](https://www.tamtam.ai/l/vc-and-private-equity-firms-california) (917)
- [Professional services firms in California](https://www.tamtam.ai/l/professional-services-firms-california) (880)
- [Companies with a mobile app in California](https://www.tamtam.ai/l/companies-with-mobile-app-california) (827)
- [Retail chains in California](https://www.tamtam.ai/l/retail-chains-california) (803)
- [IT services companies in California](https://www.tamtam.ai/l/it-services-companies-california) (796)
- [Venture Capital and Private Equity Principals companies in California](https://www.tamtam.ai/l/venture-capital-and-private-equity-principals-companies-california) (731)
- [Financial services firms in California](https://www.tamtam.ai/l/financial-services-firms-california) (711)
- [Financial Services companies in California](https://www.tamtam.ai/l/financial-services-companies-california) (642)
- [Healthcare providers in California](https://www.tamtam.ai/l/healthcare-providers-california) (569)
- [AI-native companies in California](https://www.tamtam.ai/l/ai-native-companies-california) (561)
- [Hospitals and Health Care companies in California](https://www.tamtam.ai/l/hospitals-and-health-care-companies-california) (555)
- [Consulting firms in California](https://www.tamtam.ai/l/consulting-firms-california) (551)
- [Public sector organisations in California](https://www.tamtam.ai/l/public-sector-organisations-california) (535)

## The same list elsewhere in United States

- [Telecommunications companies in the United States](https://www.tamtam.ai/l/telecommunications-companies-united-states) (750)
- [Telecommunications companies in Texas](https://www.tamtam.ai/l/telecommunications-companies-texas) (81)
- [Telecommunications companies in New York State](https://www.tamtam.ai/l/telecommunications-companies-new-york-state) (56)
- [Telecommunications companies in Florida](https://www.tamtam.ai/l/telecommunications-companies-florida) (55)
- [Telecommunications companies in Virginia](https://www.tamtam.ai/l/telecommunications-companies-virginia) (40)
- [Telecommunications companies in Georgia](https://www.tamtam.ai/l/telecommunications-companies-georgia) (26)
- [Telecommunications companies in Massachusetts](https://www.tamtam.ai/l/telecommunications-companies-massachusetts) (26)
- [Telecommunications companies in New York](https://www.tamtam.ai/l/telecommunications-companies-new-york) (26)

## The same list elsewhere

- [Telecommunications companies in the world](https://www.tamtam.ai/l/telecommunications-companies-in-the-world) (3,307)
- [Telecommunications companies in North America](https://www.tamtam.ai/l/telecommunications-companies-in-north-america) (899)

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Source: https://www.tamtam.ai/l/telecommunications-companies-california