Patent ID: 7702342

Claim:
A method for implementing a message service based on IP Multimedia Subsystem (IMS), the method comprising: determining a network domain of a called subscriber according to information in a message service of a calling subscriber; conducting the message service according to a type of the network domain of the called subscriber, wherein the information in the message service of the calling subscriber comprises a called subscriber identifier; wherein the process of determining the network domain comprises determining the network domain of the called subscriber by an IMS-based network domain of a calling side according to a format of the called subscriber identifier in a MESSAGE request of the message service of the calling subscriber; wherein the network domain of the called subscriber comprises an IMS-based network domain or a non-IMS-based network domain that comprises a Circuit Switch/Packet Switch (CS/PS)-based network domain; wherein the process of determining the network domain comprises: determining, by the IMS-based network domain of the calling side, that the network domain of the called subscriber is the IMS-based network domain, if the called subscriber identifier is in a Session Initial Protocol Uniform Resource Identifier (SIP URI) format; determining, by the IMS-based network domain of the calling side, that the network domain of the called subscriber is the non-IMS-based network domain, if the called subscriber identifier is in a non-SIP URI format and can not be converted into the SIP URI format; wherein the process of determining the network domain further comprises determining that the network domain of the called subscriber is the CS/PS-based network domain, if the called subscriber identifier is in a telephone (TEL) URI format and can not be converted into the SIP URI format; wherein in the process of determining the network domain, a Serving-Call Session Control Function (S-CSCF) or an IP-Short Message-Gateway (IP-SM-GW) corresponding to the calling subscriber determines the network domain of the called subscriber; wherein if the S-CSCF corresponding to the calling subscriber determines the network domain of the called subscriber, and when the called subscriber identifier is in the non-SIP URI format and can not be converted into the SIP URI format, the process of conducting the message service comprises: forwarding, by the S-CSCF corresponding to the calling subscriber, the MESSAGE request of the message service to the IP-SM-GW to proceed to conduct the message service outside the IMS-based network domain.