Oi SA engages in the provision of telecommunications utility services. The firm offers mobile, broadband, pay television, data transmission, and Internet provider services. It operates through the following segments: Residential Services, Personal Mobility, and B2B Services. The Residential Services segment focuses on the sale of fixed telephony services including, voice services, data communication services, and pay TV. The Personal Mobility segment offers mobile telephony services to subscription and prepaid customers, and mobile broadband customers. The B2B Services segment includes corporate solutions offered to small, medium-sized, and large corporate customers including, voice services and corporate data solutions, as well as certain interconnection services, wholesale network usage services, and traffic transportation services. The company was founded on November 27, 1963 and is headquartered in Rio de Janeiro, Brazil.