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.

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.

Cequint Incorporated provides technology that enables wireless carriers to offer caller ID services in North America. The company's City ID, a caller ID product displays the city and state beneath the number of wireless call received. Its product is used by carriers, manufacturers, and end customers. Cequint Incorporated was founded in 2004 and is headquartered in Seattle, Washington.

AT&T Intellectual Property (formerly known as AT&T Knowledge Ventures) is the holding company used for AT&T, Inc.'s trademarks & intellectual property assets. Formerly known as SBC Knowledge Ventures, L.P., and, before 2004, SBC Properties, L.P., the trademark holding was formed in late 2001, when the SBC name was added to the beginning of the names of its telephone companies.

Vesta Corp. provides electronic payment solutions. It processes secure payments for goods and services through various channels, including Internet, mobile phones, retail point of sale, and mobile commerce applications. The firm also offers mobile payment platform for mobile operators that support various products, such as prepaid top up, bill payments, mobile broadband payments, content payments, connected devices, and mobile commerce. It serves the telecommunications, financial services, technology, and e-commerce industries. The company was founded in 1995 and is headquartered in Lake Oswego, OR.

SK Telecom Co., Ltd. (Hangul: SK텔레콤 or 에스케이텔레콤) is a South Korean wireless telecommunications operator; it is part of the SK Group, one of the country's largest chaebols. SK Telecom is South Korea's largest wireless carrier: it leads the local market with 50.5 percent share as of 2008. Since its creation in 1984, the company has evolved from a first generation analog cellular system, to second generation CDMA, then to the world's first third-generation synchronized IMT-2000 cellular system. SK Telecom also became the world's first carrier to commercialize HSDPA in May 2006. SK expanded into the landline market by acquiring second-rated fixed-line operator Hanaro Telecom in February 2008.

Five9 is a provider of cloud software for the enterprise contact center market, bringing the power of the cloud to thousands of customers and facilitating approximately three billion customer interactions annually. Since 2001, Five9 has led the cloud revolution in contact centers, helping organizations transition from legacy premise-based solutions to the cloud. Five9 provides businesses reliable, secure, compliant, and scalable cloud contact center software designed to create exceptional customer experiences, increase agent productivity and deliver tangible business results.

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.

Part of Lumen Technologies, Inc. (Louisiana), CenturyLink Intellectual Property LLC is an American company that engages in filing patent rights.

LG Dacom Corp. provides communications services. The company provides Internet, Internet leased line, Web hosting, server hosting and mail hosting services. The company offers Internet backbone design & implementation, advisory, network schema design, equipment management and installation services. The company was founded in 1982 and is headquartered in Seoul, Korea.

InterMetro Communications, Inc. (Ticker: IMTO) is a leading facilities-based provider of enhanced voice and data communication services. We own and operate a national, private, proprietary voice-over Internet Protocol (VoIP) network infrastructure powered by state-of-the-art switching equipment. Our robust network transports carrier-quality enhanced voice services that can be packaged into customized high margin products. Our network powers some of the industries’ leading providers of communication services, such as: wholesale transport carriers, wireless providers, broadband phone companies, VoIP service providers, prepaid calling card providers, and voice-enabled application service providers. Our experienced team has a customer-centric approach with a proven track record of success. InterMetro is headquartered in Simi Valley, California. - See more at: http://www.intermetro.net/about-us/our-company/#sthash.ejS2rdvb.dpuf

Unreal Estate helps people buy and sell homes at a fraction of the cost of traditional brokers. We charge low, flat fees nationwide, enabling sellers to rapidly list thousands of homes on the relevant Multiple Listing Services (MLS). Leaving one-dimensional real estate search engines behind, we simplify the home buying and selling headache by packaging all services in one user-friendly location and guiding people through the step-by-step process with ease. Our clients save 3% of the home cost and over $11,000 on average.

Techno-Alliance Corp. provides technical support on operating systems and software products. It offers systems development and cloud services. The company was founded on March 3, 1992 and is headquartered in Tokyo, Japan.

New World Technologies is a provider of QuickBooks Integration solutions that are geared toward cutting the operating expenses of their small business customers. They work diligently researching and developing solutions for small businesses to facilitate time management and growth. Their goal is to reduce the amount of time and money you spend on day to day operations, so you can focus on the more important aspects of your business like sales and marketing.

Telefonaktiebolaget LM Ericsson engages in the provision of telecommunications equipment and related services to mobile and fixed network operators. It operates through the following segments: Networks, Digital Services, Managed Services, and Emerging Business and Other. The Networks segment supports all radio-access technologies and offers hardware, software and related services for both radio access and transport. The Digital Services segment provides software and services in the areas of digital business support systems, operational support systems, cloud communication, cloud core, and cloud infrastructure. The Managed Services segment includes networks and information technology managed services, network design and optimization, and application development and maintenance. The Emerging Business and Other segment encompasses emerging business, Iconectiv, Red Bee Media, and Media Solutions. The company was founded by Lars Magnus Ericsson in 1876 and is headquartered in Kista, Sweden.