Patent ID: 9532292
Filing Date: 2016-12-27
CPC Classification: H04L,H04W

Claim Text:
1. A communication system that configures an IMS (IP Multimedia Subsystem) network, comprising: a femtocell base station; a service control device; a core device that controls a call; and a database device, wherein said service control device has an SGSN (Serving GPRS Support Node) function section that sends back a signal transmitted from a network that uses a communication procedure different from that of the IMS network in the same manner as a signal transmitted from an SGSN, a plurality of service control devices being provided in said IMS network, wherein one of the plurality of service control devices has been designated as a representative service control device, wherein said database device comprises: storage that correlatively stores a P-TMSI (Packet-Temporary Mobile Subscriber Identity) issued to a UE (User Equipment) and address information of a service control device that manages a femtocell base station to which the UE belongs; a search device that searches said storage for address information correlated with the P-TMSI received from said representative service control device; and address transmitter that transmits the address information for which said search device has searched said storage to said representative service control device, and wherein said service control device comprises: request transmitter that is used as said representative service control device and transmits a P-TMSI contained in a PDP (Packet Data Protocol) context succession request signal received according to a handover communication procedure prescribed in an applicable standard as an address request to said database device; and forward controller that is used as said representative service control device and that forwards the PDP context succession request signal received by said request transmitter to an address represented by address information of the service control device received from said database device, wherein said service control device comprises: first registration request device that transmits the P-TMSI received from the femtocell base station that belongs to its own service control device and the address information of its own service control device as a registration request to said database device, wherein said first registration request device transmits the registration request to said database device after the first registration request device receives the P-TMSI from the femtocell base station that belongs to its own service control device until the PDP context is activated.