Telef nica, S.A. () is a Spanish broadband and telecommunications provider with operations in Europe, Asia, North America and South America. Operating globally, it is one of the largest mobile network providers in the world. The company started as a public telecommunications company. Its head office is in the Distrito Telef nica in Madrid. As well as the Telef nica brand, it also trades as O2 and Movistar. Telef nica is a supporter of the Hybrid Broadcast Broadband TV (HbbTV) initiative (a consortium of broadcasting and Internet industry companies including SES, OpenTV, and Institut f r Rundfunktechnik) that is promoting and establishing an open European standard for hybrid set-top boxes for the reception of broadcast TV and broadband multimedia applications with a single user interface, and has run pilot HbbTV services in Spain.