| 摘要 |
The invention relates to a Method for providing a roaming functionality related to an Internet Protocol Multimedia Subsystem (IMS) session, wherein a first User Equipment (UE A) is associated to a Home Public Land Mobile Network (HPLMN) and wherein first the User Equipment (UE A) roams in a Visited Public Land Mobile Network (VPLMN), wherein the Home Public Land Mobile Network (HPLMN) comprises a first Internet Protocol Multimedia Subsystem (IMS) domain, wherein the Visited Public Land Mobile Network (VPLMN) comprises a second Internet Protocol Multimedia Subsystem (IMS) domain, and wherein the Visited Public Land Mobile Network (VPLMN) comprises a Roaming Border Control Function (RBCF), - wherein in case of a session set-up request originating from the first User Equipment (UE A) (mobile originating case) the method comprises the steps of the second Internet Protocol Multimedia Subsystem (IMS) domain transmitting a session set-up request to the first Internet Protocol Multimedia Subsystem (IMS) domain, and the first Internet Protocol Multimedia Subsystem (IMS) domain transmitting a session set-up request to the Roaming Border Control Function (RBCF), and - wherein in case of a session set-up request terminating at the second User Equipment (UE B) (mobile terminating case) the method comprises the steps of the Roaming Border Control Function (RBCF) transmitting a session set-up request to the first Internet Protocol Multimedia Subsystem (IMS) domain, and the first Internet Protocol Multimedia Subsystem (IMS) domain transmiting a session set-up request to the second Internet Protocol Multimedia Subsystem (IMS) domain. |
