摘要 |
A data communications method of a mobile communications system in which a security association table is applied to a terminal in network is provided to be unnecessary to perform additional security procedure without influence on the size of the other message. Control information including information indicating a security setting parameter is transmitted in a terminal(S810). The security relation procedure within the security parameter table is performed. The security parameter table is made of security parameters corresponding to security setting parameter indexes with a plurality of security setting parameter indexes corresponding to the security setting parameter index determined through the control information. In the security setting parameter index is the security parameter table, it indicates whether any parameter will be used. |