SECURE CALL SERVICE METHOD USING RADIO COMMUNICATION SYSTEM

摘要

A secure call service method using a radio communication system is provided to prevent an individual key from being exposed to the outside by storing the individual key in an EPROM(Erasable and Programmable Read Only Memory) of a terminal. A secure call service method using a radio communication system includes the steps of: transmitting an invite message of a client A(11) to a server B(12) from an SIP(Session Initiation Protocol) proxy server(301); transmitting a receipt answer(100 Trying) and a bell answer(180 Ringing) to the SIP proxy server from the server B and transmitting the answers to the client A from the SIP proxy sever(302,303); transmitting a 200 OK message to the SIP proxy server from the server B by setting an SDP(Session Description Protocol) of the server B and transmitting the 200 OK message to the client A from the SIP server when receiving an answer of the server B(304); transmitting an ACK message for informing of receipt of the message to the SIP proxy server from the client A in response to the 200 OK message and transmitting the ACK message to the server B from the SIP proxy server(305); starting real VoIP(Voice over Information Provider) voice service between the client A and the server B(306); transmitting a BYE message as an SIP message for session finish from the server B(307); and finishing the session by receiving the 200 OK message as an answer of the receipt of the BYE message from the client A(308).