Communication system and communication controlling method

Abstract

A communication method in LIPA/SIPTO architecture is provided which, when a user equipment (UE) is to connect from a serving area to an external network, allows re-selection of an optimal gateway. The communication method allows selecting a gateway apparatus physically or topologically close to a site, where the user equipment is attached.

1 . A communication method in Local IP Access (LIPA)/Selected IP Traffic Offload (SIPTO) architecture, the method comprising:
 a Serving General Packet Radio Service Support Node (SGSN) sending a page signal to a user equipment, when the user equipment is in an EPS Connection Management (ECM)-IDLE state;   the user equipment, on receipt of the page signal, transmitting a service request signal to the SGSN;   the SGSN, on receipt of the service request signal, sending a deactivate request to a radio access apparatus;   the radio access apparatus transmitting an RRC (Radio Resource Control) connection reconfiguration to the user equipment;   the user equipment transmitting a notification of completion of the RRC connection reconfiguration to the radio access apparatus;   the radio access apparatus transmitting a deactivate response to the SGSN; and   the user equipment initiating a packet data network connectivity procedure to cause the SGSN to perform re-selection of a gateway apparatus.   
     
     
         2 . The communication method according to  claim 1 , wherein the gateway apparatus includes at least a serving gateway apparatus and a packet data network gateway apparatus. 
     
     
         3 . The communication method according to  claim 1 , wherein the gateway apparatus includes a Gateway General Packet Radio Service Support Node (GGSN). 
     
     
         4 . The communication method according to  claim 1 , wherein the radio access apparatus includes a Radio Network Controller (RNC). 
     
     
         5 . A communication system in Local IP Access (LIPA)/Selected IP Traffic Offload (SIPTO) architecture, the system comprising:
 a plurality of gateway apparatuses;   a Serving General Packet Radio Service Support Node (SGSN);   a radio access apparatus; and   a user equipment, wherein   the SGSN sends a page signal to the user equipment, when the user equipment is in an EPS Connection Management (ECM)-IDLE state;   the user equipment, on receipt of the page signal, transmits a service request signal to the SGSN;   the SGSN, on receipt of the service request signal, sends a deactivate request to the radio access apparatus;   the radio access apparatus transmits an RRC (Radio Resource Control) connection reconfiguration to the user equipment;   the user equipment transmits a notification of completion of the RRC connection reconfiguration to the radio access apparatus;   the radio access apparatus transmits a deactivate response to the SGSN; and   the user equipment initiates a packet data network connectivity procedure to cause the SGSN to perform re-selection of the gateway apparatus.   
     
     
         6 . The communication system according to  claim 5 , wherein the gateway apparatus includes at least a serving gateway apparatus and a packet data network gateway apparatus. 
     
     
         7 . The communication system according to  claim 5 , wherein the gateway apparatus includes a Gateway General Packet Radio Service Support Node (GGSN). 
     
     
         8 . The communication system according to  claim 5 , wherein the radio access apparatus includes a Radio Network Controller (RNC). 
     
     
         9 . A user equipment in a communication system by Selected IP Traffic Offload (SIPTO) architecture, wherein on receipt of a page signal from a Serving General Packet Radio Service Support Node (SGSN), when the user equipment is in an EPS Connection Management (ECM)-IDLE state, the user equipment transmits a service request signal to the SGSN,
 the user equipment, on receipt of an RRC (Radio Resource Control) connection reconfiguration transmitted from a radio access apparatus, transmits a notification of completion of the RRC connection reconfiguration to the radio access apparatus; and   the user equipment initiates a packet data network connectivity procedure to cause the SGSN to perform re-selection of a gateway apparatus to which the user equipment is to be connected.   
     
     
         10 . The user equipment according to  claim 9 , wherein the gateway apparatus includes at least a serving gateway apparatus and a packet data network gateway apparatus. 
     
     
         11 . The user equipment according to  claim 9 , wherein the gateway apparatus includes a Gateway General Packet Radio Service Support Node (GGSN). 
     
     
         12 . The user equipment according to  claim 9 , wherein the radio access apparatus includes a Radio Network Controller (RNC).