The technical features of this document provide a method and wireless apparatus for processing data associated with bearer resources, session management, and/or mobility management. The method comprises transmitting a packet data network connectivity request message to a mobility management entity (MME) for establishing a packet data network connection; receiving a session management back-off time value from the MME when a request of bearer resource modification or bearer resource allocation for the established packet data network connection is rejected by the MME; starting a session management back-off timer according to the session management back-off time value, the session management back-off timer being associated with the established packet data network connection; and receiving a deactivate bearer context request message, from the MME, including a cause code indicating that reactivation is requested and stopping the session management back-off timer if the session management back-off timer is running.