Mobile communication method and mobile management node

A mobile communication method comprising:

• a step of transmitting, by a relay node having a secure channel established between the relay node and a subscriber identification module for a relay node, an attach request signal for requesting an attach process executed as the relay node to a radio base station;
• a step of transmitting, by the radio base station, an initial signal indicating the attach process executed as the relay node to a mobile management node in response to the attach request signal;
• a step of starting, by the mobile management node, an authentication and key agreement procedure between the relay node and the subscriber identification module for a relay node in response to the initial signal;
• a step of determining, by the mobile management node, whether the subscriber identification module for a relay node can be used for the attach process executed as the relay node on the basis of subscriber data acquired from a subscriber management server;
• a step of setting NAS security between the mobile management node and the relay node when it is determined that the subscriber identification module for a relay node can be used for the attach process executed as the relay node;
• and
• a step of failing in the authentication and key agreement procedure when it is determined that the subscriber identification module for a relay node cannot be used for the attach process executed as the relay node.