EXTENSION LINE CALL DEVICE OF MOBILE COMMUNICATION TERMINAL IN PRIVATE BRANCH WIRELESS TELEPHONE SYSTEM AND METHOD THEREOF, ESPECIALLY CONCERNED WITH USING MOBILE COMMUNICATION TERMINAL AS INTERPHONE

摘要

PURPOSE: An extension line call device of a mobile communication terminal in a private branch wireless telephone system and a method thereof are provided to use a mobile communication terminal as an interphone by installing a DECT module in the mobile communication terminal. CONSTITUTION: A base station(51) communicates with a portable device accessing the base station(51) through a radio communication channel in order to perform a cell site function of a medium access layer among DECT protocols. A PABX(Private Automatic Branch Exchange)(52) communicates with the base station(51) to perform a cluster control function of the medium access layer among DECT protocols and processes a protocol of a data link layer and a network layer. A mobile communication terminal(30) has a DECT module(31) inside to process a call if entering a private network under the control of the base station(51).