Method of managing mobility management layer of a mobile device

A method of managing a mobility management layer in a mobile device, comprising:

• the mobility management layer entering a waiting state including establishing a radio resource connection without establishing any mobility management connection;
• acquiring a waiting period after the mobility management layer enters the waiting state;
• the mobility management layer exiting the waiting state according to a command received from a network if the waiting period does not exceed a predetermined value or the mobility management layer exiting the waiting state if the waiting period exceeds the predetermined value;
• determining whether the command associated with exiting the waiting state is received from the network if the waiting period does not exceed the predetermined value;
• and
• the mobility management layer exiting the waiting state and performing a specific action corresponding to the command when receiving the command,
• wherein the specific action includes an “RR (radio resource) connection release” action, an “indicate MM (mobility management) connection” action, an “MS (mobile station) deactivated and attach allowed” action, or an “RR connection release not allow” action defined in a 3GPP (the 3rd Generation Partnership Project) specification 24.008 rel-11.2.