Mercury Corp. designs and manufactures telecommunications equipment. Its products include Fiber, Network, Access, and Voice Switch. The company was founded on August 21, 2000 and is headquartered in Incheon, South Korea.

AT&T Inc. is an American multinational conglomerate holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the world's largest telecommunications company, the largest provider of mobile telephone services, and the largest provider of fixed telephone services in the United States through AT&T Communications. Since June 14, 2018, it is also the parent company of mass media conglomerate WarnerMedia, making it the world's largest media and entertainment company in terms of revenue. As of 2018, AT&T is ranked #9 on the Fortune 500 rankings of the largest United States corporations by total revenue.

Huawei Technologies is a telecom solutions company that offers infrastructure application software and devices with wireline, wireless, and IP technologies. The company’s products and solutions have been deployed in over 100 countries and have served 45 of the world's top 50 telecom operators as well as one third of the world's population. Huawei Technologies has 3 divisions in the United States: enterprise (IP networking and routers, wireless, storage, data center security), carrier, and consumer devices (smartphones and tablets). Founded in January 1987, Huawei Technologies is headquartered in Shenzhen, Guangdong. Its testing lab is based in Plano, Texas with an additional office in Santa Clara, California.

Expanding 4.5 million fixed lines to 20 million in just 12 years, kt introduced universal telephone service to every citizen of Korea, leading the development and advancement of communications services. More recently, kt established an advanced broadband network for the first time in Asia, and launched Korea's first communication satellite 'Mugunghwa (Sharon's Rose)', contributing to making Korea one of the most advanced countries in information and communications. Since becoming a government-funded corporation in 1997, kt changed its business portfolio to focus more on wireless and internet services instead of fixed lines. Taking over Hansol M.com and merging with its subsidiary KTF, kt expanded its business scope and included mobile communication as its main service. kt became a privately owned company in 2002 and began concentrating on building broadband network. As a result, the company set several new records including the increase of ADSL subscribers to 6 million in just 3 years and played a leading role in the age of digital networking.

Mitel is a global provider of business communications and collaboration software and services. Mitel’s innovations make it easier to connect and collaborate, while reducing costs and implementation headaches. Market leaders like VMware and Research in Motion partner with Mitel to seamlessly integrate their solutions – increasing value to customers. Mitel’s Freedom Architecture provides the flexibility and simplicity required for today's dynamic work environment. Through a single cloud-ready software stream, Mitel delivers a powerful suite of advanced communications and collaboration capabilities that: (1)provides freedom from walled garden architectures; (2)enables organizations to implement best-of-breed solutions; (3)extends the "in-office" experience anywhere, on any device; and (4)offers a choice of commercial options to fit business needs. Mitel’s solutions fit companies across the spectrum – from single-location businesses to multinationals – servicing customers through a network of over 1,600 value-added resellers and partners.

UTStarcom is a provider of interactive protocol-based network solutions in China. It offers integration and support services in internet protocol TV (IPTV), interactive (iD) TV, internet TV, and broadband for cable and telecom operators. The company’s focus is to design and sell IP-based telecommunications infrastructure products, including its primary product suite of IPTV. It also offers broadband solutions along with the ongoing services relating to the installation, operation, and maintenance of these products. Collectively, its range of solutions is designed to expand and modernize telecommunications networks through smooth network system integration, lower operating costs, and increased broadband access. It also provides telecommunications carriers and other customers with increased revenue opportunities by enhancing their subscribers’ user experience. The majority of its sales have been to service providers in China, Japan, and India. It also sells to service providers in selected markets in Asia Pacific, Latin America, and Europe. UTStarcom was established in Delaware in 1991. Its headquarters were previously in Alameda, California, with its research and design and manufacturing operations primarily in China and its sales offices in the key markets which it serves. In September 2010, the company moved its operational headquarters to Beijing, China. On March 3, 2000, it went public on NASDAQ, raising US$200 million.

Designs and builds a wide range of public and private networks, communications systems and software, and data networking systems, as well as telephone systems and microelectronic components

China Mobile Communications Group Co., Ltd. provides basic telecommunications services. It also offers value-added telecommunications, Internet audiovisual programs, mobile television distribution, and Internet protocol television transmission services. Its business activities include radio and television program production and operation, management of system integration, roaming settlement and clearing, technology development, technical services, and advertising. The company was founded on July 22, 1999 and is headquartered in Beijing, China.

Daewoo Telecom Ltd. is a company headquartered in the South Korea ultimately controlled by the Government of South Korea focused on computers and computer peripheral equipment and software.

Nortel Networks has hung up on the telecom sector. Once one of the largest makers of telecommunications equipment in North America, it filed for bankruptcy protection in 2009 and is in the process of liquidating its assets. The company made core network switching, wireless, and optical systems for network operators. Its wireline and enterprise network equipment included systems for digital voice and data switching, routing, and call center communications. Wireless products included cellular base stations and controllers. The company also made such long-haul fiber-optic products as multiplexers. Nortel is currently focused on selling off its remaining businesses and intellectual property and winding down all operations. Today, Nortel's Metro Ethernet Networks segment provides carrier Ethernet switching, optical networking, and multi-service switching products.

Siemens AG is a technology company, which engages in the areas of automation and digitalization in the process and manufacturing industries, infrastructure for buildings and energy systems, mobility solutions for rail transport, and medical technology and digital healthcare services. It operates through the following segments: Digital Industries, Smart Infrastructure, Mobility, Siemens Healthineers, and Siemens Financial Services. The Digital Industries segment offers a product portfolio and system solutions for automation used in discrete and process industries. The Smart Infrastructure segment includes products, systems, solutions, services and software to support a transition from fossil to renewable energy sources. The Mobility segment combines all Siemens businesses in the area of passenger and freight transportation. The Siemens Healthineers segment develops, manufactures, and sells diagnostic and therapeutic products, and services to healthcare providers. The Siemens Financial Services segment focuses on financing solutions for Siemens’ customers as well as other companies in the form of debt and equity investments. The company was founded by Johann Georg Halske and Werner von Siemens on October 12, 1847 and is headquartered in Munich, Germany.

Provides inspection, verification, testing and certification services

China Mobile Group Jiangsu Co., Ltd. is a subsidiary of China Mobile Ltd. It is a telecommunication company that caters the province of Jiangsu. The company is headquartered in Jiangsu, CN.

AG Communication Systems Corp., part of Nokia Oyj, is a company headquartered in Phoenix, AZ, that develops and manufactures communication products and services.

Omnipoint Corp. is a provider of personal communications services and a\ndeveloper of technology.