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 Selected IP Traffic Offload (SIPTO) architecture, the method comprising:
 selecting a gateway apparatus physically or topologically close to a site, where a user equipment is attached, when the user equipment  5  is in an EPS Connection Management (ECM)-IDLE state.   
     
     
         2 . The communication method according to  claim 1 , wherein the site, where the user equipment is attached, includes a node apparatus. 
     
     
         3 . The communication method according to  claim 1 , wherein the gateway apparatus includes at least one of a serving gateway apparatus and a packet data network gateway apparatus. 
     
     
         4 . A communication system in Selected IP Traffic Offload (SIPTO) architecture, wherein the system selects a gateway apparatus physically or topologically close to a site, where a user equipment is attached, when the user equipment is in an EPS Connection Management (ECM)-IDLE state. 
     
     
         5 . The communication system according to  claim 4 , wherein the site of attachment includes a node apparatus. 
     
     
         6 . The communication system according to  claim 4 , wherein the gateway apparatus includes at least one of a serving gateway apparatus and a packet data network gateway apparatus. 
     
     
         7 . A user equipment in a communication system by Selected IP Traffic Offload (SIPTO) architecture, wherein the user equipment causes a gateway apparatus physically or topologically close to a site, where the user equipment is attached, to be selected, when the user equipment is in an EPS Connection Management (ECM)-IDLE state. 
     
     
         8 . The user equipment according to  claim 7 , wherein the site of attachment includes a node apparatus. 
     
     
         9 . The user equipment according to  claim 7 , wherein the gateway apparatus includes at least one of a serving gateway apparatus and a packet data network gateway apparatus.