Terminal device, mme, and control method

Abstract

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.

1 . A terminal device configured to:
 establish a first PDN (Packet Data Network) connection with a first gateway;   transmit a tracking area update request message to a base station and receive, as a response to the tracking area update request message, a tracking area update accept message including identification information indicating that at least a PDN connection is reestablished;   transmit, on the basis of the reception of the identification information, to an MME (Mobility Management Entity), a first PDN connectivity request message for establishing a second PDN connection;   establish, on the basis of the transmission of the first PDN connectivity request message, the second PDN connection with a second gateway; and   delete the first PDN connection after establishing the second PDN connection.   
     
     
         2 . The terminal device according to  claim 1 , configured to:
 execute handover from a first base station to a second base station;   in the handover, receive a handover command message from the first base station,   the handover command message including identification information indicating that at least a tracking area update procedure is executed; and   transmit, on the basis of the reception of the identification information, to the second base station, a tracking area update request message.   
     
     
         3 . A terminal device configured to:
 establish a first PDN (Packet Data Network) connection with a first gateway;   execute handover from a first base station to a second base station;   in the handover, receive a handover command message from the first base station, the handover command message including identification information indicating that at least a PDN connection is reestablished;   transmit, on the basis of the reception of the identification information, to an MME (Mobility Management Entity), a first PDN connectivity request message;   establish, on the basis of the transmission of the first PDN connectivity request message, a second PDN connection with a second gateway; and   delete the first PDN connection after establishing the second PDN connection.   
     
     
         4 . The terminal device according to  claim 1 , configured to:
 establish the first PDN connection by transmitting, to the MME, a second PDN connectivity request message including at least an APN permitted to establish a PDN connection using a different gateway as an endpoint,   the first PDN connectivity request message for establishing the second PDN connection being transmitted with at least the APN included in the first PDN connectivity request message.   
     
     
         5 . The terminal device according to  claim 1 , configured to:
 request establishment of the second PDN connection and deletion of the first PDN connection by transmitting the first PDN connectivity request message for establishing the second PDN connection;   establish the second PDN connection; and   delete the first PDN connection.   
     
     
         6 . An MME (Mobility Management Entity) configured to:
 receive, via a base station, a tracking area update request message transmitted by a terminal device having a first PDN (Packet Data Network) connection with a first gateway;   transmit, as a response to the tracking area update request message, to the terminal device, a tracking area update accept message including identification information indicating that at least a PDN connection is reestablished;   receive, from the terminal device, a first PDN connectivity request message for establishing a second PDN connection;   establish, on the basis of the reception of the first PDN connectivity request message, the second PDN connection between a second gateway and the terminal device; and   delete the first PDN connection after establishing the second PDN connection.   
     
     
         7 . The MME according to  claim 6 , configured to:
 receive a handover request message from the base station; and   transmit, to the base station, a handover command message that is a response to the handover request message and includes identification information for requesting execution of at least a tracking area update procedure.   
     
     
         8 . An MME (Mobility Management Entity) configured to:
 receive, from a base station, a handover request message for handover of a terminal device having a first PDN (Packet Data Network) connection with a first gateway;   transmit, to the base station, a handover command message that is a response to the handover request message and includes identification information indicating that at least a PDN connection is reestablished;   receive, from the terminal device, a first PDN connectivity request message for establishing a second PDN connection;   establish, on the basis of the reception of the first PDN connectivity request message, the second PDN connection between a second gateway and the terminal device; and   delete the first PDN connection after establishing the second PDN connection.   
     
     
         9 . The MME according to  claim 6 , configured to:
 receive a second PDN connectivity request message including at least an APN permitted to establish a PDN connection using a different gateway as an endpoint and permit establishment of the first PDN connection; and   receive the first PDN connectivity request message for establishing the second PDN connection, the message including at least the APN.   
     
     
         10 . The MME according to  claim 6 , wherein the deletion of the first PDN connection is executed on the basis of the reception of the first PDN connectivity request message for establishing the second PDN connection. 
     
     
         11 . The MME according to  claim 6 , wherein the first PDN connection is a PDN connection for selected IP traffic offload (SIPTO). 
     
     
         12 . A method of controlling a terminal device, the method comprising the steps of:
 establishing a first PDN (Packet Data Network) connection with a first gateway;   transmitting a tracking area update request message to a base station and receiving, as a response to the tracking area update request message, a tracking area update accept message including identification information indicating that at least a PDN connection is reestablished;   transmitting, on the basis of the reception of the identification information, to an MME (Mobility Management Entity), a first PDN connectivity request message for establishing a second PDN connection;   establishing, on the basis of the transmission of the first PDN connectivity request message, the second PDN connection with a second gateway; and   deleting the first PDN connection after establishing the second PDN connection.   
     
     
         13 . The method of controlling a terminal device according to  claim 12 , the method comprising the steps of:
 in handover, receiving a handover command message from a first base station, the handover command message including identification information indicating that at least a tracking area update procedure is executed; and   transmitting, on the basis of the reception of the identification information, to a second base station, a tracking area update request message.   
     
     
         14 . A method of controlling a terminal device, the method comprising the steps of:
 establishing a first PDN (Packet Data Network) connection with a first gateway;   in handover, receiving a handover command message from a first base station,   the handover command message including identification information indicating that at least the first PDN connection is reestablished;   transmitting, on the basis of the reception of the identification information, to an MME (Mobility Management Entity), a first PDN connectivity request message for establishing the first PDN connection;   establishing, on the basis of the transmission of the first PDN connectivity request message, a second PDN connection with a second gateway; and   deleting the first PDN connection after establishing the second PDN connection.   
     
     
         15 . The method of controlling a terminal device according to  claim 12 , the method comprising the steps of:
 establishing the first PDN connection by transmitting, to the MME, a second PDN connectivity request message including at least an APN permitted to establish a first PDN connection using a different gateway as an endpoint; and   including the APN into the first PDN connectivity request message for establishing the second PDN connection.   
     
     
         16 . The method of controlling a terminal device according to  claim 12 , the method comprising the steps of:
 requesting establishment of the second PDN connection and deletion of the first PDN connection by transmitting the first PDN connectivity request message for establishing the second PDN connection; and   establishing the second PDN connection; and   deleting the first PDN connection.   
     
     
         17 . A method of controlling an MME (Mobility Management Entity), the method comprising the steps of:
 receiving, via a base station, a tracking area update request message transmitted by a terminal device having a first PDN (Packet Data Network) connection with a first gateway;   transmitting, as a response to the tracking area update request message, to the terminal device, a tracking area update accept message including identification information indicating that at least a PDN connection is reestablished;   receiving, from the terminal device, a first PDN connectivity request message for establishing a second PDN connection;   establishing, on the basis of the reception of the first PDN connectivity request message, the second PDN connection between a second gateway and the terminal device; and   deleting the first PDN connection after establishing the second PDN connection.   
     
     
         18 . The method of controlling an MME according to  claim 17 , the method comprising the steps of:
 receiving a handover request message from the base station; and   transmitting, to the base station, a handover command message that is a response to the handover request message and includes identification information for requesting execution of at least a tracking area update procedure.   
     
     
         19 . A method of controlling an MME (Mobility Management Entity), the method comprising the steps of:
 receiving, from a base station device, a handover request message for handover of a terminal device having a first PDN (Packet Data Network) connection with a first gateway;   transmitting, to the base station, a handover command message that is a response to the handover request message and includes identification information indicating that at least the first PDN connection is reestablished;   receiving, from the terminal device, a first PDN connectivity request message for establishing a second PDN connection;   establishing, on the basis of the reception of the first PDN connectivity request message, the second PDN connection between a second gateway and the terminal device; and   deleting the first PDN connection after establishing the second PDN connection.   
     
     
         20 . The method of controlling an MME according to  claim 17 , the method comprising the steps of:
 receiving a second PDN connectivity request message including at least an APN permitted to establish a PDN connection using a different gateway as an endpoint and establishing the first PDN connection; and   including the APN into the first PDN connectivity request message for establishing the second PDN connection.   
     
     
         21 . The method of controlling an MME according to  claim 17 , the method comprising the steps of:
 establishing, on the basis of the reception of the first PDN connectivity request message for establishing the second PDN connection; and,   deleting the first PDN connection.   
     
     
         22 . The method of controlling an MME according to  claim 17 , wherein the first PDN connection is a PDN connection for SIPTO (Selected IP Traffic Offload). 
     
     
         23 . The terminal device according to  claim 3 , configured to:
 establish the first PDN connection by transmitting, to the MME, a second PDN connectivity request message including at least an APN permitted to establish a PDN connection using a different gateway as an endpoint,   the first PDN connectivity request message for establishing the second PDN connection being transmitted with at least the APN included in the first PDN connectivity request message.   
     
     
         24 . The terminal device according to  claim 3 , configured to:
 request establishment of the second PDN connection and deletion of the first PDN connection by transmitting the first PDN connectivity request message for establishing the second PDN connection;   establish the second PDN connection; and   delete the first PDN connection.   
     
     
         25 . The MME according to  claim 8 , configured to:
 receive a second PDN connectivity request message including at least an APN permitted to establish a PDN connection using a different gateway as an endpoint and permit establishment of the first PDN connection; and   receive the first PDN connectivity request message for establishing the second PDN connection, the message including at least the APN.   
     
     
         26 . The MME according to  claim 8 , wherein the deletion of the first PDN connection is executed on the basis of the reception of the first PDN connectivity request message for establishing the second PDN connection. 
     
     
         27 . The MME according to  claim 8 , wherein the first PDN connection is a PDN connection for selected IP traffic offload (SIPTO). 
     
     
         28 . The method of controlling a terminal device according to  claim 14 , the method comprising the steps of:
 establishing the first PDN connection by transmitting, to the MME, a second PDN connectivity request message including at least an APN permitted to establish a first PDN connection using a different gateway as an endpoint; and   including the APN into the first PDN connectivity request message for establishing the second PDN connection.   
     
     
         29 . The method of controlling a terminal device according to  claim 14 , the method comprising the steps of:
 requesting establishment of the second PDN connection and deletion of the first PDN connection by transmitting the first PDN connectivity request message for establishing the second PDN connection; and   establishing the second PDN connection; and   deleting the first PDN connection.   
     
     
         30 . The method of controlling an MME according to  claim 19 , the method comprising the steps of:
 receiving a second PDN connectivity request message including at least an APN permitted to establish a PDN connection using a different gateway as an endpoint and establishing the first PDN connection; and   including the APN into the first PDN connectivity request message for establishing the second PDN connection.   
     
     
         31 . The method of controlling an MME according to  claim 19 , the method comprising the steps of:
 establishing, on the basis of the reception of the first PDN connectivity request message for establishing the second PDN connection; and,   deleting the first PDN connection.   
     
     
         32 . The method of controlling an MME according to  claim 19 , wherein the first PDN connection is a PDN connection for SIPTO (Selected IP Traffic Offload).