Бразилияның ірі телекоммуникациялық компаниясы – Oi

Brazilian telecommunication company

Oi (ˈoj, Portuguese for "Hi"), formerly known as Telemar, is the largest fixed telephone operator and the fourth mobile telephone operator in Brazil, being the third largest telecommunication company in Latin America. It is headquartered in Rio de Janeiro. In 2013, Oi announced its merger with Portugal Telecom, the largest telecommunication company in Portugal. In June 2015, Portugal Telecom was acquired by Altice Group.

Oi launched its mobile network in 2002 in its license states. It was the first network using GSM in Brazil. Oi has the practice of not calling its phones "cell phones", but rather "Ois". In 2007, Oi started selling only unlocked handsets, focusing on SIM card and plan sales. In October 2007, Oi acquired a license to operate with GSM in São Paulo, where the network went live on October 24, 2008. In December 2007, Oi purchased licenses to operate a 3G network in its area, including São Paulo, but with the exception of the Franca area. That network is expected to go live in 2009. Also in December 2007, Oi announced its purchase of Amazônia Celular, which was a condition of the sale of its sister company, Telemig Celular, to Vivo.

Oi Internet is an ISP that was launched in 2004. Oi Internet started services with a promotion that offered 31% off the dial up connection costs on the subscriber's bill. However, Anatel, the Brazilian telecom regulator, did not allow this practice. Later, the ISP relaunched the promotion, offering 31% of the dial up connection costs deposited in the subscriber's bank account or twice of that on a prepaid Oi phone. The Oi Internet dial up dialer can send SMS messages to Oi phones. In early 2005, Oi Internet launched its broadband services, initially available only for Oi's Oi Velox DSL subscribers, but now also available for Brasil Telecom Turbo and Telefónica Speedy subscribers.

In 2008, Oi announced it would purchase Brasil Telecom, creating a major Brazilian telecommunications company, already nicknamed "Supertele" or "SuperOi". That takeover required changes in legislation, which at the time prohibited a fixed telephone company from purchasing another fixed telephone company in a different license area. That legislation has changed since, and Oi completed its purchase of Brasil Telecom on January 9, 2009. Rollout of the Oi brand in the Brasil Telecom area starts with prepaid mobile service on May 17, 2009.

Oi has been criticized and fined by Anatel due to not being able to meet quality goals in their mobile phone service; they have also been criticized for poor customer service.