A user equipment (UE) transmits a packet data network (PDN) connectivity request message to a mobility management entity (MME), receives a PDN connectivity accept message, and establishes a PDN connection with a second local gateway (LGW) in accordance with the PDN connectivity accept message. Thus, it is possible to provide a communication system and the like for a purpose of implementing the optimal communication control for enabling the UE to continue communication by switching a previously established PDN connection to a new PDN connection using a more optimal gateway.