INTERFACE DEVICE BETWEEN MOBILE PHONE LINE AND FIXED TELEPHONE RECEIVER CONNECTED OR NOT TO A FIXED TELEPHONE LINE AND PROCESS OF FUNCTIONING.

摘要

An interface device (800) and a method for interfacing a mobile telephone (200) to a plurality of fixed telephones (300) for enabling a user to originate a call at one of said fixed telephones (300) either to a recipient located in the mobile communication network using a first interface unit (10) for interfacing the mobile telephone (200) or to a recipient in the public switched telephone network (PSTN) using a fixed line connection to the PSTN. The interface device unit (10) comprises a ring detector (1) for detecting incoming calls at the mobile telephone (200), an interchangeable unit (4) for adapting the size to the mobile telephone (200) and a battery charge circuit (2) for charging the mobile telephone (200). The interface unit (80) for interfacing the plurality of fixed telephones (300) comprising a ring generator (81), an on hook / off hook detector (82), a conditioner for line and busy tones (83), and a DTMF tone decoder (84). The interface device further includes an audio switching unit (30) and a controlling unit (20) that controls the interface device (800). The controlling unit (20) comprises a microprocessor (21), a memory storing the program (22), a watchodog timer (50), a line tone generator (24) and a busy tone generator (23).