Nokia is a networking equipment vendor focused primarily on supporting wireless networks and, to a growing extent, Internet Protocol and optical systems. The firm operates three segments. The mobile infrastructure segment sells equipment and software used to operate the core of carrier and enterprise wireless networks. Network infrastructure comprises IP, optical, and fixed-network equipment, including switching and routing equipment, optical components, and devices used in fiber-to-the-premises networks. The portfolio business comprises businesses considered noncore to Nokia in the future, including fixed wireless access customer premises equipment, enterprise campus edge, and microwave radio.