This invention provides a number of improvements to wireless telephone systems. There is an adapter box for interfacing standard telephone equipment to an IR-based telephone interface to replace the acoustic modem now used. A telepoint repeater system allows users to "roam" throughout the area and not be tied to a particular IR input point in the building. An IR through-the-wall repeater conducts an IR signal through a wall without having to bore a hole through it. A public telephone call-back enhancement allows a caller on an IR public telephone system to receive incoming calls. A handset credit interface system allows a portable handset (IR, RF, or cellular) to be employed as a credit transaction interface transmitting credit information directly to the credit computer. An IR interfacing base station allows a handset intended for interfacing with a public telepoint to be used at home for connection to the home's telephone line as a wireless telephone. A multi-purpose handset system includes RF transmission capability with IR capability. A passive handset system includes light-modulating smartcard technology in the handset for modulating and returning the lightbeam from the telepoint so as to provide extremely low power consumption by the handset. There is an IR PBX type telephone system. The IR telepoint is also used as a building multi-user interface to connect a plurality of users from a building to a telepoint at a site of multiple telephone lines employing an IR link. An IR telephone system for convention centers, stadiums, etc. is disclosed.