However, its most popular application is single-cell cordless phones connected to traditional analog telephone, primarily in home and small-office systems, though gateways with multi-cell DECT and/or DECT repeaters are also available in many private branch exchange (PBX) systems for medium and large businesses, produced by Panasonic, Mitel, Gigaset, Snom, BT Business, Spectralink, and RTX Telecom. DECT can also be used for purposes other than cordless phones, such as baby monitors and industrial sensors. The ULE Alliance's DECT ULE and its "HAN FUN" protocol[2] are variants tailored for home security, automation, and the internet of things (IoT).