Patent ID: 7564975
Filing Date: 2009-07-21
Classification: H04L,H04W

Abstract:
1. A method of ciphering call information transferred between a mobile communication terminal and a network, comprising: connecting a call between the terminal and the network; transferring call information between the terminal and network without ciphering the call information; transmitting a ciphering request from the terminal to the network after the call information has been transferred between the terminal and network without ciphering; transmitting a ciphering authentication request message from the network to the terminal in response to the ciphering request; transmitting a ciphering authentication response message from the terminal to the network in response to the ciphering authentication request message; transmitting a ciphering activation completion message from the network to the terminal in accordance with the ciphering authentication response message; and ciphering additional call information to be transmitted between the terminal and network after the ciphering activation completion message is received from the network and after the call information has been transferred between the terminal and network without ciphering, wherein the ciphering request is transmitted during transfer of data from the terminal to the network during the call and after the call information has been transferred between the terminal and network without ciphering.