Calling method, device and system

Abstract

A calling method includes: a first CSCF device receiving a first communication message containing first call signaling, where the initiator / calling party or the recipient / called party of the first call signaling is a roaming user equipment of the first CSCF device; and the first CSCF device routing the first call signaling to a roaming AS of the roaming user equipment based on the first communication message. The roaming AS is an AS in the home area of ​​the first CSCF device that is capable of providing value-added call services to the user equipment. This method can improve resource utilization of the roaming AS and enhance the service experience of roaming users.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of communication technologies, and in particular to a calling method, device, and system. Background Art

[0002] In an Internet Protocol (IP) Multimedia Subsystem (IMS) network, a user equipment (UE) may move from its home area to another area, which is called a roaming area. If the UE initiates call signaling in the roaming area, the session control function device in the roaming area that receives the relevant call message must route the call message to the UE's home area to trigger the application server (AS) in the home area to provide the UE with value-added call services, such as ring back tone services, advertising video services, and short message services. The call message is then routed to the called UE.

[0003] This results in a large end-to-end delay between the roaming user equipment and the home AS, which reduces the user experience of calling value-added services. For example, there may be a freeze when watching a ringback tone advertisement. Summary of the Invention

[0004] The embodiments of the present application provide a calling method, apparatus, and system to solve the problems of long end-to-end delay between a user equipment roaming outside its home area and its home AS, and low network resource utilization of the AS.

[0005] To achieve the above objectives, the present invention adopts the following technical solutions:

[0006] In the first aspect, an embodiment of the present application provides a calling method, which is applied to a first call session control function CSCF device, the method including: receiving a first communication message containing a first call signaling, the initiator or recipient of the first call signaling is a roaming user device of the first CSCF device, and routing the first call signaling to a roaming AS of the roaming user device based on the first communication message, the roaming AS being an AS in the home area of ​​the first CSCF device that has the ability to provide call value-added services to the user device, so that the roaming AS provides call value-added services to the roaming user device.

[0007] Based on the method described in the first aspect, when the calling party or the called party is a roaming user device of the first CSCF device, call signaling is routed to the roaming AS of the roaming user device, and the roaming AS of the roaming user device provides the roaming user device with a value-added call service. Because a user device roaming outside of its home area is relatively close to its roaming AS, the roaming AS of the roaming user device provides the value-added call service to the user device. The roaming user device is relatively close to its roaming AS, and the end-to-end latency between the roaming user device and its roaming AS is relatively low, thereby improving the user experience. Furthermore, in the call method provided in the embodiments of the present application, the application server can provide value-added call services not only for local callers but also for roaming user devices roaming into their home area, thereby increasing the opportunities for the AS to provide services to the caller and improving network resource utilization.

[0008] In one possible design, the first call signaling is routed to the roaming application server AS of the roaming user equipment based on the first communication message, including: determining that the initiator or recipient of the first call signaling is the roaming user equipment of the first CSCF device based on the first communication message, and in response to the first communication message, routing the first call signaling to the roaming AS.

[0009] Based on this possible design, call signaling can be routed to the roaming AS, triggering the roaming AS to provide call value-added services to the roaming user equipment. Since the distance between the user equipment and the roaming AS is relatively close, the end-to-end delay between the user equipment and the roaming AS is relatively low, which can improve the user experience and the utilization of AS network resources.

[0010] In one possible design, the first call signaling is routed to the roaming AS, including: sending a second communication message to a second CSCF device in the home area of ​​the first CSCF device or the roaming AS, the second communication message including the first call signaling and first indication information, the first indication information indicating that the initiator or recipient of the first call signaling is a roaming user device of the first CSCF device.

[0011] Based on this possible design, the first CSCF device can send the second communication message directly to the roaming AS, or send the second communication message to the roaming AS through the second CSCF device, effectively and flexibly designing the sending method of the second communication message while simplifying the system design.

[0012] In one possible design, the first indication information further indicates that the first call signaling or the second call signaling of the call service corresponding to the first call signaling is routed to the roaming AS of the roaming user equipment.

[0013] Based on this possible design, the first indication information is given the function of instructing to route the call signaling to the roaming AS. The devices on the call signaling transmission route route the call signaling to the roaming AS according to the first indication information, thereby simplifying the system design.

[0014] In one possible design, the method further includes: storing the first indication information in correspondence with the call service or communication session corresponding to the first call signaling.

[0015] Based on this possible design, the call service or communication session corresponding to the first indication information and the first call signaling can be stored accordingly, so that after the device on the call signaling transmission route receives the call signaling again, the call signaling can be routed to the roaming AS according to the call route designed in the embodiment of the present application according to the first indication information in the corresponding relationship, triggering the roaming AS to provide call value-added services.

[0016] In one possible design, the second communication message further includes address information of the second CSCF device, so that the second communication message is routed to the second CSCF device.

[0017] Based on this possible design, the communication message carrying the call signaling can be routed to the roaming AS through the second CSCF device according to the address information of the second CSCF device, thereby simplifying the system design.

[0018] In one possible design, determining that the initiator or recipient of the first call signaling is a roaming user device of the first CSCF device based on the first communication message includes: determining that the initiator of the first call signaling is a roaming user device of the first CSCF device based on the from header field or the PAI header field in the first communication message; or determining that the recipient of the first call signaling is a roaming user device of the first CSCF device based on the to header field in the first communication message.

[0019] Based on this possible design, it is possible to determine whether the initiator or receiver of the call signaling is a roaming user equipment according to the information carried in the header field of the communication message, thereby simplifying the system design.

[0020] In one possible design, the method also includes: receiving a third communication message sent by the roaming AS, the third communication message including first call signaling, first indication information and second indication information, the second indication information being used to indicate that the roaming AS will provide value-added call services for the roaming user equipment; or, the second indication information being used to indicate that the roaming AS has provided value-added call services for the roaming user equipment; and sending a fourth communication message to a third CSCF device in the home area of ​​the roaming user equipment, the fourth communication message including the first call signaling, the first indication information and the second indication information.

[0021] Based on this possible design, the communication message sent by the roaming AS can be routed to the home area of ​​the roaming user equipment, such as to the home AS in the home area, so that the home AS handles the service conflict according to the content carried in the communication message, thereby avoiding the service conflict caused by the home AS and the roaming AS providing call value-added services to the roaming user equipment at the same time.

[0022] In one possible design, the method also includes: receiving a fifth communication message from a third CSCF device in the home area of ​​the roaming user equipment, the fifth communication message including first indication information and third indication information, the three indication information being used to indicate that the home AS of the roaming user equipment will provide value-added call services for the roaming user equipment; and sending a sixth communication message to the roaming AS based on the first indication information, the sixth communication message including the first indication information and the third indication information.

[0023] Based on this possible design, the communication message sent by the home AS can be routed back to the roaming AS in the roaming area of ​​the roaming user equipment, so that the roaming AS can handle the service conflict according to the content carried in the communication message, thereby avoiding the service conflict problem caused by the home AS and the roaming AS providing call value-added services to the roaming user equipment at the same time.

[0024] In one possible design, the method also includes: receiving a fifth communication message from a third CSCF device in the home area of ​​the roaming user equipment, the fifth communication message including first indication information and second indication information; and sending a sixth communication message to the roaming AS based on the first indication information, the sixth communication message including the first indication information and the second indication information.

[0025] Based on this possible design, the communication message sent by the home AS can be routed back to the roaming AS in the roaming area of ​​the roaming user equipment, so that the roaming AS can handle the service conflict and avoid the service conflict caused by the home AS and the roaming AS providing call value-added services to the roaming user equipment at the same time.

[0026] In one possible design, before routing the first call signaling to the roaming AS based on the first communication message, the method further includes: determining whether the roaming user equipment has the ability to use the call value-added service provided by the AS in the home area of ​​the first CSCF device.

[0027] Based on this possible design, in addition to routing call signaling to the roaming AS, it is possible to determine whether the roaming user equipment supports the ability to use the value-added call service provided by the AS in the home area of ​​the first CSCF device. Only when such capability is possessed, the call signaling is roamed to the AS, triggering the roaming AS to provide the value-added call service, thereby avoiding the problem of being unable to present the value-added call service due to the user equipment not having the ability to support the value-added call service provided by the roaming AS.

[0028] In one possible design, the second CSCF device in the home area of ​​the first CSCF device is an inquiry-call session function I-CSCF device or a service-call session control function S-CSCF device in the home area of ​​the first CSCF device. The first CSCF device is a proxy-call session control function P-CSCF device.

[0029] Based on this possible design, the device for implementing the calling method of the embodiment of the present application is designed effectively and flexibly.

[0030] In the second aspect, an embodiment of the present application provides a calling method, which is applied to a second call session control function CSCF device, and the method includes: receiving a second communication message from a first call session control function CSCF device, the second communication message including a first call signaling, and the initiator or recipient of the first call signaling is a roaming user device of the first CSCF device; based on the second communication message, the first call signaling is routed to a roaming application server AS of the roaming user device, and the roaming AS is an AS in the home area of ​​the first CSCF device that has the ability to provide call value-added services to the user device.

[0031] Based on the method described in the second aspect, call signaling is routed to the roaming AS of the roaming user device, and the roaming AS of the roaming user device provides the roaming user device with value-added call services. Because a user device roaming outside its home area is closer to its roaming AS, the roaming AS of the roaming user device provides the value-added call services to the user device. Due to the close distance between the user device and the roaming AS, the end-to-end latency between the user device and the roaming AS is low, thereby improving the user experience. Furthermore, the application server can provide value-added call services not only to local callers but also to roaming user devices roaming into their home area. This increases the opportunities for the AS to provide services to callers and improves network resource utilization.

[0032] In one possible design, the second communication message also includes first indication information, and the first indication information is used to indicate that the initiator or recipient of the first call signaling is a roaming user device of the first CSCF device; based on the second communication message, the first call signaling is routed to the roaming application server AS of the roaming user device, including: sending the second communication message to the roaming AS according to the first indication information.

[0033] In one possible design, the first indication information further indicates that the first call signaling or the second call signaling of the call service corresponding to the first call signaling is routed to the roaming AS of the roaming user equipment.

[0034] In one possible design, the method further includes: storing the first indication information in correspondence with the call service or communication session corresponding to the first call signaling.

[0035] In one possible design, the second communication message further includes address information of the second CSCF device, so that the second communication message is routed to the second CSCF device.

[0036] In one possible design, the method also includes: receiving a third communication message sent by the roaming AS, the third communication message including first call signaling, first indication information and second indication information, the second indication information being used to indicate that the roaming AS will provide value-added call services for the roaming user equipment, or the second indication information being used to indicate that the roaming AS has provided value-added call services for the roaming user equipment; and sending a fourth communication message to a third CSCF device in the home area of ​​the roaming user equipment, the fourth communication message including the first call signaling, the first indication information and the second indication information.

[0037] In one possible design, the method also includes: receiving a fifth communication message from a third CSCF device in the home area of ​​the roaming user equipment, the fifth communication message including first indication information and third indication information, the three indication information being used to indicate that the home AS of the roaming user equipment will provide value-added call services for the roaming user equipment; and sending a sixth communication message to the roaming AS based on the first indication information, the sixth communication message including the first indication information and the third indication information.

[0038] In one possible design, the method also includes: receiving a fifth communication message from a third CSCF device in the home area of ​​the roaming user equipment, the fifth communication message including first indication information and second indication information; and sending a sixth communication message to the roaming AS based on the first indication information, the sixth communication message including the first indication information and the second indication information.

[0039] In one possible design, the second CSCF device is an inquiry-call session function I-CSCF device in the home area of ​​the first CSCF device or a service-call session control function S-CSCF device in the home area of ​​the second CSCF device.

[0040] Among them, the relevant descriptions of the first indication information, the second communication message, and the second CSCF device can refer to the first aspect or the possible design of the first aspect and are not repeated here.

[0041] In the third aspect, an embodiment of the present application provides a calling method, applied to a first AS, the method comprising: receiving a second communication message from a first call session control function CSCF device or a second CSCF device; the second communication message includes a first call signaling, and the initiator or recipient of the first call signaling is a roaming user device of the first CSCF device or the second CSCF device; and providing a call value-added service for the roaming user device based on the second communication message.

[0042] Based on the method described in the third aspect, the roaming AS of the roaming user device provides a value-added call service to the roaming user device. Because a user device roaming outside of its home area is relatively close to its roaming AS, the roaming AS of the roaming user device provides the value-added call service to the user device. Due to the close distance between the roaming user device and the roaming AS, the end-to-end latency between the roaming user device and its roaming AS is low, thereby improving the user experience. Furthermore, in the calling method provided in the embodiments of the present application, the application server can provide the value-added call service not only to the local caller but also to the roaming user device roaming into its home area. This increases the opportunity for the AS to provide services to the caller and improves network resource utilization.

[0043] In one possible design, the second communication message further includes first indication information, where the first indication information is used to indicate that the initiator or recipient of the first call signaling is a roaming user equipment of the first CSCF device.

[0044] In one possible design, the first indication information also indicates that the first call signaling or the second call signaling of the call service corresponding to the first call signaling is routed to the first AS.

[0045] In one possible design, the method further includes: storing the first indication information in correspondence with the call service or communication session corresponding to the first call signaling.

[0046] In one possible design, providing a call value-added service for a roaming user device based on a second communication message includes: providing a call value-added service for the roaming user device in response to the second communication message; sending a third communication message to a second CSCF device, the third communication message including a first call signaling, a first indication information, and a second indication information, the second indication information indicating that the first AS has provided the call value-added service for the roaming user device.

[0047] In one possible design, providing a call value-added service to a roaming user device based on a second communication message includes: sending a third communication message to a second CSCF device in response to the second communication message, the third communication message including first call signaling, first indication information, and second indication information, the second indication information indicating that the first AS will provide a call value-added service to the roaming user device; receiving a sixth communication message from the second CSCF device, the sixth communication message including the first call signaling, the first indication information, and the third indication information, the third indication information indicating that the AS of the home location of the roaming user device will provide a call value-added service to the roaming user device; and providing the call value-added service to the roaming user device in response to the sixth communication message.

[0048] Among them, the relevant descriptions of the first indication information, the second communication message, the second CSCF device, the third communication message, the fourth communication message, the fifth communication message, and the sixth communication message can be referred to in the first aspect or the possible design of the first aspect, and will not be repeated here.

[0049] In the fourth aspect, an embodiment of the present application provides a calling method, applied to a second AS, the method comprising: receiving a seventh communication message from a third call session control function CSCF device; the seventh communication message includes a first call signaling, and the initiator or recipient of the first call signaling is a home user device of the third CSCF device; based on the seventh communication message, the first call signaling or the second call signaling of the call service corresponding to the first call signaling is routed to the first AS, and the first AS is the AS of the roaming area of ​​the home user device.

[0050] Based on the method described in the fourth aspect, the home AS routes call signaling to the roaming AS, and the roaming AS provides value-added call services to the roaming user device. Because a user device roaming outside of its home area is relatively close to its roaming AS, the roaming AS of the roaming user device provides the value-added call service to the user device. Due to the close distance between the roaming user device and the roaming AS, the end-to-end latency between the roaming user device and its roaming AS is low, improving the user experience. Furthermore, in the call method provided in the embodiments of the present application, the application server can provide value-added call services not only to local callers, but also to roaming user devices roaming into their home area. This increases the opportunity for the AS to provide services to the caller and improves network resource utilization.

[0051] In one possible design, the seventh communication message also includes first indication information, and the first indication information is used to indicate that the initiator or recipient of the first call signaling is a roaming user device of the first CSCF device, and the first CSCF device is a CSCF device in the roaming area of ​​the home user equipment.

[0052] In one possible design, the first indication information further indicates that the first call signaling or the second call signaling of the call service corresponding to the first call signaling is routed to the roaming area AS of the home user equipment.

[0053] In one possible design, the method further includes: storing the first indication information in correspondence with the call service or communication session corresponding to the first call signaling.

[0054] In one possible design, the first call signaling is routed to the first AS based on the seventh communication message, including: in response to the seventh communication message, sending an eighth communication message to the third CSCF device, including the first call signaling, the first indication information and the third indication information, the third indication information indicating that the second AS will provide call value-added services for the roaming user equipment.

[0055] In one possible design, the first call signaling is routed to the first AS based on the seventh communication message, including: in response to the seventh communication message, sending an eighth communication message to the third CSCF device, including the first call signaling and the first indication information.

[0056] Among them, the relevant descriptions of the first indication information and the second communication message can refer to the first aspect or the possible design of the first aspect and will not be repeated here.

[0057] In a fifth aspect, the present application provides a communication device, which may be a functional module or physical entity that implements the first aspect or any possible design of the first aspect, or a functional module or physical entity that implements the second aspect or any possible design of the second aspect, or a functional module or physical entity that implements the third aspect or any possible design of the third aspect, or a functional module or physical entity that implements the fourth aspect or any possible design of the fourth aspect. The communication device may be implemented by hardware, or may be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions. In one design, the communication device may include a module or means corresponding to the method / operation / step / action described in the first aspect, and the module, unit, or means may be implemented by hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions. For example, the communication device may include: a receiving unit and a processing unit.

[0058] In a first possible design, the communication device may be a functional module or a physical entity that implements the first aspect or any possible design of the first aspect, wherein the receiving unit is configured to receive a first communication message including first call signaling, where the initiator or recipient of the first call signaling is a roaming user equipment of a first CSCF device. The processing unit is configured to route the first call signaling to a roaming AS of the roaming user equipment based on the first communication message, where the roaming AS is an AS in a home area of ​​the first CSCF device that has the capability of providing a value-added call service for the user equipment, so that the roaming AS provides the value-added call service for the roaming user equipment.

[0059] Among them, the relevant descriptions of the first indication information and the second communication message can refer to the first aspect or the possible design of the first aspect and will not be repeated here.

[0060] The specific implementation of the communication device can refer to the behavior and function of the first CSCF device in the call method provided in the first aspect or any possible design of the first aspect, and will not be repeated here. Therefore, the provided communication device can achieve the same beneficial effects as the first aspect or any possible design of the first aspect.

[0061] In a second possible design, the communication device may be a functional module or physical entity that implements the above-mentioned second aspect or any possible design of the second aspect, and the receiving unit is used to receive a second communication message from a first call session control function CSCF device, where the second communication message includes a first call signaling, and the initiator or recipient of the first call signaling is a roaming user device of the first CSCF device; the processing unit is used to route the first call signaling to a roaming application server AS of the roaming user device based on the second communication message, where the roaming AS is an AS in the home area of ​​the first CSCF device that has the ability to provide value-added call services to the user device.

[0062] Among them, the relevant descriptions of the first indication information and the second communication message can refer to the first aspect or the possible design of the first aspect and will not be repeated here.

[0063] The specific implementation of the communication device can refer to the behavior function of the second CSCF device in the call method provided in the second aspect or any possible design of the second aspect, and will not be repeated here. Therefore, the provided communication device can achieve the same beneficial effects as the second aspect or any possible design of the second aspect.

[0064] In a third possible design, the communication device may be a functional module or physical entity that implements the above-mentioned third aspect or any possible design of the third aspect, and the receiving unit is used to receive a second communication message from a first call session control function CSCF device or a second CSCF device; the second communication message includes a first call signaling, and the initiator or recipient of the first call signaling is a roaming user device of the first CSCF device or the second CSCF device; the processing unit is used to provide a call value-added service for the roaming user device based on the second communication message.

[0065] Among them, the relevant descriptions of the first indication information and the second communication message can refer to the first aspect or the possible design of the first aspect and will not be repeated here.

[0066] The specific implementation of the communication device can refer to the behavior function of the first AS in the call method provided in the third aspect or any possible design of the third aspect, and will not be repeated here. Therefore, the provided communication device can achieve the same beneficial effects as the third aspect or any possible design of the third aspect.

[0067] In a fourth possible design, the communication device may be a functional module or physical entity that implements the above-mentioned fourth aspect or any possible design of the fourth aspect, and the receiving unit is used to receive a seventh communication message from a third call session control function CSCF device; the seventh communication message includes a first call signaling, and the initiator or recipient of the first call signaling is a home user device of the third CSCF device; the processing unit is used to route the first call signaling or the second call signaling of the call service corresponding to the first call signaling to the first AS based on the seventh communication message, and the first AS is the AS of the roaming area of ​​the home user device.

[0068] Among them, the relevant descriptions of the first indication information and the second communication message can refer to the first aspect or the possible design of the first aspect and will not be repeated here.

[0069] The specific implementation of the communication device can refer to the behavior function of the second AS in the call method provided in the fourth aspect or any possible design of the fourth aspect, and will not be repeated here. Therefore, the provided communication device can achieve the same beneficial effects as the fourth aspect or any possible design of the fourth aspect.

[0070] In a sixth aspect, a communication device is provided. The communication device may be a first CSCF device or a chip or system-on-chip in the first CSCF device, or other modules or units capable of implementing a method on the first CSCF device side. The communication device may implement the functions performed by the first CSCF device in the first aspect or each possible design, and the functions may be implemented by hardware. In one possible design, the communication device may include: a processor and a communication interface, the processor being configured to receive a first communication message containing first call signaling through the communication interface, the initiator or recipient of the first call signaling being a roaming user equipment of the first CSCF device, and routing the first call signaling to a roaming AS of the roaming user equipment based on the first communication message, the roaming AS being an AS in the home area of ​​the first CSCF device that has the capability of providing value-added call services to user equipment, so that the roaming AS provides the value-added call services to the roaming user equipment.

[0071] In another possible design, the communication device described in the sixth aspect may be a second CSCF device or a chip or system on chip in the second CSCF device, or may be a module or unit in the second CSCF device for implementing the call method described in the embodiment of the present application, or may be other modules or units capable of implementing the method executed by the second CSCF device. For example, the communication device may include: a processor and a communication interface. The processor and communication interface included in the communication device are used to support the communication device in implementing the functions performed by the second CSCF device in the above-mentioned second aspect or each possible design of the second aspect.

[0072] In another possible design, the communication device described in the sixth aspect may be the first AS or a chip or system on chip in the first AS, or may be a module or unit in the first AS for implementing the calling method described in the embodiment of the present application, or other modules or units capable of implementing the method executed by the first AS, such as the communication device may include: a processor and a communication interface. The processor and communication interface included in the communication device are used to support the communication device to implement the functions performed by the first AS in the above-mentioned third aspect or each possible design of the third aspect, or to implement the functions performed by the first AS in the above-mentioned third aspect or each possible design of the third aspect.

[0073] In another possible design, the communication device described in the sixth aspect may be a second AS or a chip or system on chip in the second AS, or a module or unit in the second AS for implementing the calling method described in the embodiment of the present application, or other modules or units capable of implementing the method executed by the second AS, such as the communication device may include: a processor and a communication interface. The processor and communication interface included in the communication device are used to support the communication device to implement the functions performed by the second AS in the above-mentioned fourth aspect or each possible design of the fourth aspect, or to implement the functions performed by the second AS in the above-mentioned fourth aspect or each possible design of the fourth aspect.

[0074] In another possible design, the communication device of the sixth aspect may further include a memory, which is used to store computer instructions and / or data. When the communication device is running, the processor executes the computer instructions stored in the memory to enable the communication device to execute the calling method described in the first aspect or any possible design of the first aspect; or, execute the calling method described in the second aspect or any possible design of the second aspect; or, execute the calling method described in the third aspect or any possible design of the third aspect; or, execute the calling method described in the fourth aspect or any possible design of the fourth aspect. In an embodiment of the present application, the communication interface may be a transceiver, an interface circuit, a bus interface, a pin or other device capable of realizing the transceiver function.

[0075] In the seventh aspect, a computer-readable storage medium is provided, which stores instructions. When the computer-readable storage medium is run on a computer, the computer can execute the calling method described in the first aspect or any possible design of the above aspects; or, execute the calling method described in the second aspect or any possible design of the second aspect; or, execute the calling method described in the third aspect or any possible design of the third aspect; or, execute the calling method described in the fourth aspect or any possible design of the fourth aspect.

[0076] In the eighth aspect, a computer program product comprising instructions is provided. The computer program product may include program instructions. When the computer program product is run on a computer, the computer can execute the calling method described in the first aspect or any possible design of the above aspects; or, execute the calling method described in the second aspect or any possible design of the second aspect; or, execute the calling method described in the third aspect or any possible design of the third aspect; or, execute the calling method described in the fourth aspect or any possible design of the fourth aspect.

[0077] In the ninth aspect, a chip system is provided, which includes a processor and a communication interface. The chip system can be used to implement the functions performed by the first CSCF device in the above-mentioned first aspect or any possible design of the first aspect, or the chip system can implement the functions performed by the second CSCF device in the above-mentioned second aspect or each possible design of the second aspect, or implement the functions performed by the first AS in the above-mentioned third aspect or each possible design of the third aspect, or implement the functions performed by the second AS in the above-mentioned fourth aspect or each possible design of the fourth aspect.

[0078] In the tenth aspect, an embodiment of the present application further provides a communication system, which includes the communication device as described in the fifth aspect or the sixth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1a Schematic diagram 1 for a roaming user accessing the IMS network in the home area;

[0080] Figure 1b Schematic diagram of a roaming user accessing the IMS network in the home area Figure 2 ;

[0081] Figure 2 Schematic diagram of using home area call value-added service for roaming users;

[0082] Figure 3 A schematic diagram of a communication network architecture provided in an embodiment of the present application;

[0083] Figure 4 Flowchart 1 of the calling method provided in an embodiment of the present application;

[0084] Figure 5 The process of the calling method provided in the embodiment of the present application Figure 2 ;

[0085] Figure 6 This is a flow chart of a call value-added service used by a calling party in a roaming area in an embodiment of the present application;

[0086] Figure 7This is a flow chart of a call value-added service used by a called party in a roaming area in an embodiment of the present application;

[0087] Figure 8 The process of the calling method provided in the embodiment of the present application Figure 3 ;

[0088] Figure 9 The process of the calling method provided in the embodiment of the present application Figure 4 ;

[0089] Figure 10 A schematic structural diagram of the apparatus 100 provided in an embodiment of the present application;

[0090] Figure 11 A schematic diagram of the structure of the device 110 provided in an embodiment of the present application;

[0091] Figure 12 A schematic diagram of the structure of the device 120 provided in an embodiment of the present application;

[0092] Figure 13 A schematic diagram of the structure of the device 130 provided in an embodiment of the present application;

[0093] Figure 14 A schematic diagram of the structure of the device 140 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0094] Before introducing the embodiments of the present application, the relevant technical terms involved in the embodiments of the present application are explained. It should be noted that these explanations are intended to make the embodiments of the present application easier to understand and should not be regarded as limiting the scope of protection claimed by the embodiments of the present application.

[0095] The IMS network is an Internet Protocol (IP)-based network architecture that provides voice and multimedia services, meeting current end-user demand for newer and more diverse multimedia services. IMS networks have the following features: They use the Session Initiation Protocol (SIP) as a call control protocol, separating call control from service control based on SIP and enhancing multimedia support capabilities. Through home control, user devices can still access the same services in their home region even when roaming.

[0096] Roaming means that a user device moves from its own registration area / home area to another area outside the registration area / home area. The network area outside the registration area / home area of ​​the user device can be referred to as the roaming area or visited area of ​​the user device or the roaming location or visited location, and the communication network therein is referred to as a visited public land mobile network (public land mobile network, PLMN) (abbreviated as VPLMN). In the embodiment of the present application, the home area of ​​the user device can be referred to as the home location, and the communication network of the home area of ​​the user device can be referred to as the home public land mobile network (HPLMN) of the user device (abbreviated as HPLMN).

[0097] Among them, the user equipment in the roaming area can Figure 1a As shown or Figure 1b The method shown is to access the IMS network of the home area of ​​the user equipment and use the call value-added services provided by the IMS network of the home area. Figure 1a As shown, the roaming area provides data channels including data gateways and border gateways (BGs). User equipment can communicate with the data gateways in the home area (such as packet data network (PDN) gateways (P-GW)) through the data channels, access the IMS network in the home area through the data gateway in the home area, and use the call value-added services in the home area. Figure 1b As shown, the proxy-call session control function (P-CSCF) device in the roaming area communicates with the IMS network in the home area. The user equipment can access the home area of ​​the user equipment through the P-CSCF device in the roaming area and use the call value-added services in the home area.

[0098] In the prior art, a user device initiates a call request in its roaming area, but the call request can be sent through Figure 1a or Figure 1b The method shown is routed to the IMS network in the home area of ​​the user equipment, and the IMS network in the home area of ​​the user equipment provides the user equipment with call value-added services. It is impossible for the IMS in the roaming area to provide call value-added services to the roaming user equipment. For example, Figure 2The figure shows a flow chart of user equipment UE1 calling user equipment UE2. After UE1 sends an invite message to the P-CSCF device in the roaming area, the P-CSCF device in the roaming area routes the invite message to the I-CSCF device / S-CSCF device in the home area of ​​UE1. The I-CSCF device / S-CSCF device in the home area of ​​UE1 routes the invite message to the IMS network in the home area of ​​UE1, triggering the AS in the home area of ​​UE1 to provide a value-added call service for UE1. At the same time, the invite message is further routed to UE2 for call connection.

[0099] Figure 2 In the call mode shown, the user equipment UE1 roaming outside the home area can only use the call value-added services provided by the application server (AS) of UE1's home area. Since the distance between UE1 roaming outside the home area and UE1's home AS is far, the end-to-end delay between UE1 and the home AS is large, which reduces the user experience. At the same time, Figure 2 In the call mode shown, the AS of UE1's home area can only provide value-added call services for local UEs, but cannot provide value-added call services for roaming UEs in the home area, which reduces the opportunity for the AS to provide services to UEs and reduces network resource utilization.

[0100] To address the above technical issues, an embodiment of the present application provides a calling method, comprising: a first CSCF device receiving a first communication message containing first call signaling, where the initiator or caller of the first call signaling is a roaming user equipment of the first CSCF device; and the first CSCF device routing the first call signaling to a roaming AS of the roaming user equipment based on the first communication message. The roaming AS is an AS in the home area of ​​the first CSCF device that is capable of providing value-added call services to the user equipment. In this manner, the roaming AS of the roaming user equipment can provide the value-added call services to the roaming user equipment, allowing the roaming user equipment to use the value-added call services in the roaming area. Because the user equipment roaming outside its home area is relatively close to the roaming AS in the roaming area of ​​the user equipment, the roaming AS in the roaming area of ​​the user equipment provides the value-added call services to the user equipment. Due to the short distance between the roaming user equipment and the roaming AS, the end-to-end latency between the user equipment and the roaming AS is reduced, thereby improving the user experience. At the same time, in the calling method provided in the embodiment of the present application, the application server can not only provide call value-added services for local user equipment, but also provide call value-added services for roaming user equipment roaming into the home area, thereby increasing the opportunity for the AS to provide services to the user equipment and improving the utilization rate of network resources.

[0101] In the embodiments of the present application, a roaming user equipment may be a user equipment that roams from the user equipment's home area (e.g., HPLMN) to an area outside the user equipment's home area (e.g., another PLMN). From the user equipment's perspective, the area outside the home area may be referred to as the user equipment's roaming area, visited area, HPLMN, or roaming location. From the perspective of a device in the area outside the home area (e.g., a P-CSCF device, an AS, or a packet data gateway (PGW)), the user equipment may be referred to as a roaming user equipment in the area outside the home area. From the perspective of a device in the user equipment's home area (e.g., HPLMN), the user equipment may be referred to as a "roaming" user equipment. For example, assuming that UE1's home area is area 1, if UE1 roams into area 2, which is different from area 1, then from the perspective of UE1, area 1 may be referred to as UE1's home area, and area 2 may be referred to as UE1's roaming area, roaming location, or visited location. From the perspective of a P-CSCF in area 2, UE1 may be referred to as a roaming user equipment of the P-CSCF device.

[0102] In the embodiment of the present application, the roaming AS may refer to an AS in a roaming area of ​​the roaming user equipment, and the home AS may refer to an AS in a home area of ​​the roaming user equipment.

[0103] In the embodiment of the present application, a call value-added service refers to a supplementary service provided by an application server to a user device (which may be the caller or the called party) participating in the call service in the context of the call service (including before, during or after the call), in addition to the call service. Specifically, the supplementary service can be used or consumed by a call service application (Application, APP, for example, a telephone communication application, telephony APP) on the user device, or by an application associated with the call service application of the user device (such as a plug-in application, a nested application, etc.). Specifically, the supplementary service may include but is not limited to a media service and a messaging service. If the supplementary service is a media service, the application server may trigger the call service application on the user device to present media content based on call signaling, wherein the media content may be game content, ringback tone content, caller ID content, etc. If the supplementary service is a messaging service, the application server may send a video notification, SMS notification (such as a fifth generation (5G) message), etc. to the user device based on call signaling.

[0104] In the embodiments of the present application, the format of the media content may include, but is not limited to, video content, audio content, a hypertext markup language (HTML) page, a joint photographic experts group (JPEG) image, and a graphics interchange format (GIF) animation. If the format is audio content, then presenting the media content means playing the audio content on the user device. If the format is video content, an HTML page, a JPEG image, a GIF animation, etc., then presenting the media content means rendering or displaying the video content, HTML page, JPEG image, GIF animation, etc. on the user device.

[0105] In an embodiment of the present application, a call service may refer to a voice call service or a video call service conducted between a user device as a caller or a called party and other calling devices (such as the called party mentioned above) via a communication network. For example, a call service may be a voice call service or a video service conducted when a user device dials a mobile phone number, an office landline number, or a customer service center number. For another example, a call service may be a voice call service or a video service conducted when a user device receives a call from a mobile phone, an office landline, or a customer service center.

[0106] For example, taking the example of UE1 calling UE2 and AS providing value-added call services for UE1, the AS can trigger UE1 to present media content, game content, etc. on the APP interface related to the call service when UE1 dials UE2's mobile phone number - when the call request reaches UE2 or before, the AS can trigger UE1 to present media content, game content, etc. on the APP interface related to the call service when the call request reaches UE2 - UE2 rings - UE2 picks up the phone. The AS can also trigger UE1 to provide media content, game content, etc. on the APP interface related to the call service when UE2 picks up the phone - UE1 and UE2 enter into a call.

[0107] The calling method provided in the embodiment of the present application is described below with reference to the accompanying drawings.

[0108] The calling method provided in the embodiment of the present application can be applied to Figure 3 The network architecture shown in Figure 3As shown, the network architecture may include: user equipment (UE), multiple IMS networks, the multiple IMS networks may include the IMS network where the user equipment is registered, each IMS network may include a P-CSCF device, an interrogating-call session control function (I-CSCF) device, a serving-call session control function (S-CSCF) device, and an AS, and may also include access network equipment, a session border controller (SBC), and a home subscriber server (HSS) and other devices, without limitation. For example, Figure 3 The network architecture shown includes multiple UEs such as UE1, UE2, UE3, access network equipment 10, SBC11, P-CSCF equipment 12, access network equipment 20, P-CSCF equipment 21, SBC31, IMS network 1, IMS network 2 and IMS network 3. IMS network 1 includes I-CSCF equipment 13, S-CSCF equipment 14 and AS15, IMS network 2 includes I-CSCF equipment 22, S-CSCF equipment 23 and AS24, and IMS network 3 includes I-CSCF equipment 33, S-CSCF equipment 34 and AS35.

[0109] The calling method provided in the embodiments of the present application can be applied to various communication scenarios, for example, it can be applied to one or more of the following communication scenarios: enhanced mobile broadband (eMBB), ultra-reliable low latency communication (URLLC), machine type communication (MTC), massive machine type communication (mMTC), device to device (D2D), vehicle to everything (V2X), vehicle to vehicle (V2V), and Internet of Things (IoT), etc.

[0110] In the embodiment of the present application, the P-CSCF device, I-CSCF device and S-CSCF device in the IMS network can be regarded as different types of SIP proxies or servers. Figure 3 As shown, they are independently deployed in the IMS network. Alternatively, the P-CSCF, I-CSCF, and S-CSCF can be deployed together. For example, instead of deploying independent I-CSCF and S-CSCF devices, the functions of the I-CSCF and S-CSCF devices can be integrated into the P-CSCF, so that the P-CSCF device has the functions of the I-CSCF and S-CSCF devices.

[0111] Below Figure 3 The network elements in the shown architecture are introduced as follows:

[0112] User equipment (UE) can be a terminal (MT), mobile station (MS), or mobile terminal (MT). Specifically, a user equipment can be a mobile phone, tablet, or computer with wireless transceiver capabilities. It can also be a virtual reality (VR) terminal, augmented reality (AR) terminal, wireless terminal in industrial control, wireless terminal in unmanned driving, wireless terminal in telemedicine, wireless terminal in smart grid, wireless terminal in smart city, smart home, or vehicle terminal. The user equipment can first connect to the access network equipment and then access the IMS network through the packet data serving node (PDSN).

[0113] Access network equipment is primarily used to provide network services for user equipment (UEs) accessing the IMS network, implementing at least one of the following functions: resource scheduling, radio resource management, and radio access control. Specifically, access network equipment can include base stations, wireless access points, transmission receive points (TRPs), transmission points (TPs), and any other access nodes.

[0114] The P-CSCF is the entry point for user devices to access the IMS network and is responsible for interacting with user devices. It primarily generates call detail records (CDRs), handles roaming billing requirements, provides SIP compression and integrity protection on the Gm interface, and routes user device requests to the correct I-CSCF or S-CSCF.

[0115] The I-CSCF device is mainly used to allocate an S-CSCF device to provide services to the user equipment when the user equipment registers, and select the S-CSCF device registered by the called party for incoming calls.

[0116] S-CSCF equipment implements user equipment registration and authentication, service triggering and control, session routing, etc.

[0117] AS is responsible for handling specific services, such as providing value-added call services for user equipment.

[0118] SBC is a network element at the edge of the IMS network used to implement IP access, intercommunication, and security protection. It exists between the access network and the IMS network or between different IMS networks and is the entry point for users to access the IMS.

[0119] The HSS is the primary data repository for all user and service-related data within the IMS. Data stored in the HSS primarily includes user identity, registration information, access parameters, service trigger information, user device identification information, user security context, user network access authentication key information, and roaming restriction information. The HSS supports user registration and stores user location information and service subscription information.

[0120] It should be noted that Figure 3 This is just an example architecture diagram. Figure 3 In addition to the functional units shown in , the system may also include other functional network elements, such as a domain name system (DNS) server, etc. This embodiment of the present application does not limit this. In addition, Figure 3 The names of the devices in the Figure 2 In addition to the names shown, each device can also be named other names, such as replacing them with network element names with the same or similar functions, without restriction.

[0121] Optionally, the P-CSCF device, I-CSCF device, S-CSCF device, etc. in the embodiments of the present application may also be referred to as a communication device, which may be a desktop computer, a portable computer, a network server, a mobile phone, a tablet computer, a wireless terminal, an embedded device, a chip system, etc., and the embodiments of the present application do not specifically limit this. In the embodiments of the present application, the chip system may be composed of a chip, or may include a chip and other discrete devices.

[0122] Optionally, the relevant functions of the P-CSCF device, I-CSCF device, and S-CSCF device in the embodiments of the present application can be implemented by a single device, or can be implemented jointly by multiple devices, or can be implemented by one or more functional modules within a single device, and the embodiments of the present application do not specifically limit this. It is understood that the above functions can be network elements in hardware devices, software functions running on dedicated hardware, or a combination of hardware and software, or virtualized functions instantiated on a platform (e.g., a cloud platform).

[0123] The following combination Figure 3 The network architecture shown in FIG. 1 describes a calling method provided in an embodiment of the present application, taking the case where a user equipment roams to an area outside its home area and initiates a call to a called party in the area outside its home area as an example. It should be noted that the actions, terms, etc. involved in the various embodiments of the present application can be referenced to each other. The message names or parameter names in the messages exchanged between network elements in the embodiments of the present application are merely examples, and other names may be used in specific implementations. For example, "roaming" in the embodiments of the present application can also be understood as "visiting," "including" in the embodiments of the present application can also be understood as "carrying," and "storing" in the embodiments of the present application can also be understood as "recording" or "saving." In the embodiments of the present application, "roaming AS" can be replaced by "first AS," and home AS can be replaced by "second AS," and the I-CSCF device or S-CSCF device in the home area of ​​the roamed user equipment can be replaced by "third CSCF device." These are all described here as a unified description, and the embodiments of the present application do not specifically limit this.

[0124] Figure 4 A flowchart of a calling method provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, the method assumes that the user equipment roams to the area (or home area) where the first CSCF device is located, becomes a roaming user equipment of the first CSCF device, and participates in the call service as a calling party or a called party. The method includes the following steps:

[0125] S401: A first CSCF device receives a first communication message.

[0126] Specifically, a first communication message is a communication message, such as a SIP message, initiated by a caller / calling party (also known as an originating party) to call a callee / called party (also known as a receiving party or terminating party), and may also be referred to as a call message or access message. The first communication message includes first call signaling initiated by the caller, which may be a SIP Invite signaling. The first call signaling may include information about the caller and the called party. The first communication message may also include other information, such as a Content-Type header field indicating the media type of the call service (such as a voice call service or a video call service) corresponding to the first call signaling, routing-related fields for identifying the device through which the first call signaling passes, and a message body. The routing-related fields may include, but are not limited to, a Via header field, a Contact header field, or a Record-Route / Route header field. The message body may include session description information, which includes information about the media content, such as the transmission mode and codec of the media content.

[0127] Specifically, the caller's information is used to indicate the caller or identify the initiator of the first call signaling, including the caller's number or the caller's international mobile subscriber identification (IMSI) or the source address of the first communication message, etc., and can be carried in the from header field or the asserted identity (P-Asserted-Identity, PAI) header field of the first communication message.

[0128] Specifically, the called party's information can be used to indicate the called party or identify the recipient of the first call signaling, including the called party's phone number, IMSI or target address of the first communication message, etc., which can be carried in the to header field of the first communication message.

[0129] Specifically, the first CSCF device can be Figure 3 The P-CSCF device 12, P-CSCF device 21, or P-CSCF device 32 in the first call signaling may be a roaming user equipment of the first CSCF device.

[0130] Specifically, an exemplary method for the first CSCF device to receive the first communication message is as follows:

[0131] 1) When the calling party of the first call signaling is a roaming user equipment of the first CSCF device, the first CSCF device receives the first communication message from the calling party directly or indirectly, for example, through an intermediate network element between the calling party and the first CSCF device, which may be an access network device, SBC, etc. Figure 3 For example, assuming that the calling party is UE1, UE1 moves from the coverage area of ​​access network device 10 to the coverage area of ​​access network device 20. If the first CSCF device is P-CSCF device 21, the intermediate network element is access network device 20. If the first CSCF device is P-CSCF device 32, the intermediate network element is access network device 20 and SBC31.

[0132] 2) When the called party of the first call signaling is a roaming user equipment of the first CSCF device, the first CSCF device receives the first communication message directly or indirectly from the second CSCF device in the home area of ​​the called party. The second CSCF device in the home area of ​​the called party can be an I-CSCF device or an S-CSCF device in the home area of ​​the called party. Figure 3 For example, assuming that the called party is UE2, and the home area of ​​UE2 is the coverage area of ​​the access network device 10, then the second CSCF device in the home area of ​​UE2 is Figure 3 The I-CSCF device 14 or the S-CSCF device 15 in the system.

[0133] It should be understood that, in addition to SIP Invite, the first call signaling in the embodiment of the present application may also be other call signaling related to the call service between the roaming user device and other calling devices, for example, it may also be the signaling shown in Table 1; however, for the sake of convenience, the embodiment of the present application mainly uses SIP-Invite as an example to describe the relevant scheme, and will not be repeated.

[0134] Table 1

[0135]

[0136]

[0137] It should be noted that Table 1 is only an exemplary table. The embodiment of the present application does not limit the type of signaling of the first call signaling. In addition to the signaling shown in Table 1, the first call signaling can also be other signaling.

[0138] S402: The first CSCF device routes the first call signaling to the roaming AS of the roaming user equipment based on the first communication message. The roaming AS is an AS in the home area of ​​the first CSCF device that has the capability of providing a call value-added service for the user equipment.

[0139] The description of the call value-added service described in S402 can be referred to above and will not be repeated here. For example, the first CSCF device routing the first call signaling to the roaming AS of the roaming user device based on the first communication message may include: the first CSCF device determining that the caller or the called party of the first call signaling is the roaming user device of the first CSCF device based on the first communication message, and directly sending a second communication message containing the first call signaling to the roaming AS; or, the first CSCF device routing the first call signaling to the roaming AS of the roaming user device through the second CSCF device in the home area of ​​the first CSCF device, if the roaming user device is Figure 3 UE1 in the roaming AS is Figure 3 AS24 or AS25 in Figure 4 As shown in S402(a)-S402(c), they are described as follows:

[0140] S402(a): The first CSCF device determines, based on the first communication message, that the calling party or the called party of the first call signaling is a roaming user equipment of the first CSCF device.

[0141] For example, when the caller of the first call signaling is a roaming user device of the first CSCF device, the first CSCF device can determine the caller's home area based on the caller's information carried in the from header field or the PAI header field in the first communication message, and then determine that the caller's home area is different from the home area of ​​the first CSCF, thereby determining that the caller of the first call signaling is a roaming user device of the first CSCF device. Otherwise, it is determined that the caller is in its own home area and is not a roaming user device.

[0142] For example, taking the caller's information as the caller's mobile phone number 135XXXX4308, the first CSCF device can determine that the attribution area corresponding to the caller's mobile phone number segment is area 1 based on the caller's mobile phone number and the correspondence between the number segment identifying the attribution area in the mobile phone number shown in Table 2 below and the attribution area.

[0143] Table 2

[0144] Number segment Attribution area 135XXXX Area 1 135YYYY Area 2

[0145] For example, in the case where the called party of the first call signaling is a roaming user device of the first CSCF device, the first CSCF device can determine the called party's home area based on the called party's information carried in the to header field in the first communication message, and then determine that the called party's home area is different from the home area of ​​the first CSCF, thereby determining that the called party is a roaming user device of the first CSCF device; otherwise, it is determined that the called party is in its own home area.

[0146] Further, execute S402(b).

[0147] Specifically, after the first CSCF device determines that the calling party or the called party of the first call signaling is a roaming user device, before executing S402(b), the method may further include: the first CSCF device determining that the roaming user device is capable of using a value-added call service provided by an AS in the home area of ​​the first CSCF device (i.e., the roaming area of ​​the roaming user device). In this way, only when it is determined that the roaming user device supports the value-added call service provided by the AS in the roaming area is the AS in the roaming area triggered to provide the value-added call service to the roaming user device, thereby avoiding the problem that the roaming user device is unable to use the value-added call service in the roaming area due to not supporting the value-added call service provided by the AS in the roaming area, thereby affecting the user experience.

[0148] Exemplarily, the first CSCF device may obtain the capability information of the roaming user equipment from the first communication message, or may request the HSS or other devices to obtain the capability information of the roaming user equipment.

[0149] Illustratively, the first CSCF device may determine, based on a configuration policy and / or capability information of the roaming user equipment, that the roaming user equipment has the capability of using a value-added call service provided by an AS in the home area of ​​the first CSCF device.

[0150] Specifically, the configuration policy can be used to determine the roaming user equipment that has the ability to use the call value-added service provided by the AS in the home area of ​​the first CSCF device. The configuration policy may include access information corresponding to the roaming user equipment, such as one or more of the configuration information including the access network device information, cell location information, access network type, etc. of the roaming user equipment. The configuration policy can be pre-stored on the first CSCF device or obtained by the first CSCF device from other devices (such as HSS) without restriction. If the access information of the roaming user equipment meets the provisions of the configuration policy and / or the capability information of the roaming user equipment indicates that the roaming user equipment has the ability to process the call value-added service provided by the AS in the roaming area (such as media content decoding capability, network capability or storage capability, etc.), then it is determined that the roaming user equipment has the ability to use the call value-added service provided by the AS in the home area of ​​the first CSCF device.

[0151] Specifically, the access network device information can be used to identify the access network device, and can be an Internet protocol (IP) address or a media access control (MAC) address of the access network device.

[0152] Specifically, the cell location information may be used to identify a certain cell, and the cell location information may be a physical cell identifier (PCI) or a cell global identifier (CGI) of the cell.

[0153] Specifically, the access network type can be used to indicate the radio access technology (RAT) or fixed access technology adopted by the access network. RAT can include any access technology of Bluetooth access, wireless-fidelity (Wi-Fi) access, new radio (NR) access, and long term evolution (LTE) access. Fixed access technology can include local area network (LAN) technology, wireless local area network (WLAN) technology, various types of digital subscriber line (xDSL) technology, or xPON technology.

[0154] Optionally, the first CSCF device may obtain capability information and access information of the roaming user equipment from an access device of the roaming user equipment.

[0155] It should be understood that the access information of the roaming user equipment and the capability information of the roaming user equipment in other embodiments of the present application can refer to the above related descriptions and will not be repeated.

[0156] S402(b): In response to the determination result of S402(a), the first CSCF device sends a second communication message to a second CSCF device in the home zone of the first CSCF device.

[0157] Specifically, the second CSCF device in the home area of ​​the first CSCF device may be an I-CSCF device or an S-CSCF device in the home area of ​​the first CSCF device.

[0158] Specifically, the second communication message may be a SIP message, and the second communication message may include parameters included in an existing communication message (such as the first communication message), such as the first call signaling, routing-related fields, a message body, and the like. In addition, the second communication message may also include first indication information. The name of the first indication information is not limited, and may be called a "roaming identifier" or a "routing identifier" or "flag1", and may be used to indicate that the caller or the called party of the first call signaling is a roaming user device of the first CSCF device, so that the second CSCF device determines that the caller or the called party of the first call signaling is a roaming user device based on the first indication information, and triggers the roaming AS of the roaming user device to provide a call value-added service for the roaming user device.

[0159] Furthermore, the first indication information may also indicate that the first call signaling or the second call signaling of the call service corresponding to the first call signaling is routed to the roaming AS of the roaming user equipment. The call service is as described above. In the embodiment of the present application, the call signaling of the call service may include the first call signaling and the second call signaling. The second call signaling of the call service refers to other call signaling related to the call service other than the first call signaling or other call signaling transmitted after the first call signaling. For example, the second call signaling may include the signaling shown in Table 1 above. For example, assuming that the first call signaling included in the first communication message is SIP Invite, the second call signaling of the corresponding call service may be called party busy signaling, called party power-off signaling, called party no-answer signaling, called party unreachable signaling, called party waiting signaling, called party call forwarding signaling, called party ringing signaling, called party off-hook signaling, calling party hang-up signaling, and called party hang-up signaling.

[0160] It should be understood that the first indication information is essentially a kind of "routing indication information". The routing indication information can change the call route traversed by the call signaling of the call service transmitted between the calling party and the called party. The call route will pass through the roaming AS of the roaming user equipment, so that the call signaling of the call service is routed to the roaming AS of the roaming user equipment, so that the roaming AS of the roaming user equipment has the opportunity to provide call value-added services to the roaming user, for example, triggering the roaming user equipment to present media content during the call service. After the call route traversed by the first call signaling of the call service (such as the Invite message when the call is initiated) is determined, the subsequent call signaling corresponding to the call service can be transmitted according to the call route.

[0161] In order to determine the call route traversed by the first call signaling of a call service (such as the Invite message when initiating a call) and to enable subsequent call signaling corresponding to the call service to be transmitted along the call route, each device on the call route can store the first indication information in correspondence with the call service or communication session corresponding to the first call signaling. In this way, after subsequently receiving other call signaling corresponding to the same call service or communication session, the first indication information can be obtained according to the stored correspondence, and then the first call signaling can be determined to be routed to the roaming AS based on the first indication information.

[0162] For example, taking the case where the caller is a roaming user device of the first CSCF device and the caller sends a SIP Invite to the called party, the original route of the SIP Invite: (caller-first CSCP device in the caller's roaming area-I-CSCF device / S-CSCF device in the caller's home area-called party) can be changed to the following route: (caller-first CSCP device in the caller's roaming area-I-CSCF device / S-CSCF device in the caller's roaming area-caller's roaming AS-I-CSCF device / S-CSCF device in the caller's roaming area-I-CSCF device / S-CSCF device in the caller's home area-called party). The first CSCP device in the roaming area of ​​the caller of the changed route, the I-CSCF device / S-CSCF device in the roaming area of ​​the caller, the roaming AS of the caller, the I-CSCF device / S-CSCF device in the roaming area of ​​the caller, the I-CSCF device / S-CSCF device in the home area of ​​the caller, etc. can store the first indication information in correspondence with the call service or communication session corresponding to the first call signaling, for example, store the first indication information in correspondence with the call service identifier or the communication session identifier.

[0163] Specifically, each device on the changed route may carry the first indication information in a communication message (such as a second communication message or other communication message) using the following method 1 or method 2:

[0164] Method 1: Carrying the first indication information through a new header field in the communication message. For example, the new header field may be an incoming visit indication header field (P-visted-incoming-indication).

[0165] Method 2: Carry the first indication information through the attributes of the existing header field in the communication message. For example, the attributes of the existing P-Access-Network-Info header field include a roaming indication (roam-incoming-indication). The value of roam-incoming-indication identifies whether the calling party or called party of the first call signaling is a roaming user device.

[0166] For example, as shown in the following fields, the P-Access-Network-Info header field includes, in addition to the existing fields, roam-incoming-indication = 1, indicating that the calling party or called party of the first call signaling is a roaming user equipment:

[0167] P-Access-Network-Info:

[0168] 3GPP-E-UTRAN;utran-cell-id-3gpp=46001251C6042203;roam-incoming-indication=1;

[0169] ue-ip=[2408:8556:41C:B3BF:7BDA:1BDD:2241:5983];ue-port=43518;network-provided.

[0170] In one example, when the first CSCF device and the I-CSCF device / S-CSCF device are deployed independently, the first CSCF device sending the second communication message to the AS in the home area of ​​the first CSCF device may include: the first CSCF device sending the second communication message to the second CSCF device in the home area of ​​the first CSCF device, where the second CSCF device may be the I-CSCF device / S-CSCF device in the home area of ​​the first CSCF device; the second CSCF device receives the second communication message and sends the second communication message to the AS of the home area of ​​the first CSCF.

[0171] In this example, because the calling party or called party of the first call signaling is a roaming user device of the first CSCF device, and the roaming user device is not registered in the first CSCF device's home zone, the first CSCF device does not have registration information for the roaming user device. Therefore, the first CSCF device cannot locally locate the I-CSCF device / S-CSCF device with which the roaming user device is registered. Therefore, the first CSCF device can randomly select a CSCF device from multiple CSCF devices in the first CSCF device's home zone as the second CSCF device. Alternatively, based on the principle of load balancing, the CSCF device with the lowest load, or a load below a preset threshold, can be selected from multiple CSCF devices in the first CSCF device's home zone as the second CSCF device. The preset threshold can be set as needed and is not limited.

[0172] Specifically, the multiple CSCF devices in the home area of ​​the first CSCF device may be multiple I-CSCS devices or S-CSCF devices in the home area of ​​the first CSCF device.

[0173] Specifically, selecting the CSCF device with the smallest load as the second CSCF device may include: if the first call signaling carried by the first communication message is the Mth first call signaling received by the first CSCF device, then selecting the i-th CSCF device among the M CSCF devices in the home area of ​​the first CSCF device as the second CSCF device, i = MmodN, M and N are integers greater than or equal to 1.

[0174] For example, taking the second CSCF device as an I-CSCF device, and there are 5 I-CSCF devices in the home area of ​​the first CSCF device, the first CSCF device can carry the received first first call signaling in the communication message and send it to the first I-CSCF device, carry the received second first call signaling in the communication message and send it to the second I-CSCF device, carry the received third first call signaling in the communication message and send it to the third I-CSCF device, carry the received fourth first call signaling in the communication message and send it to the fourth I-CSCF device, and so on, carry the received fifth first call signaling in the communication message and send it to the fifth I-CSCF device, carry the sixth first call signaling in the communication message and send it to the first I-CSCF device, and carry the eighth first call signaling in the communication message and send it to the third I-CSCF device.

[0175] Optionally, the second communication message may also include the address information of the second CSCF device, such as the routing-related field of the second communication message includes the address information of the second CSCF device, so that the previous hop of the second CSCF device routes the first call signaling or the second call signaling of the call service corresponding to the first call signaling to the second CSCF device according to the address information of the second CSCF device.

[0176] S402 (c): The second CSCF device in the home area of ​​the first CSCF device receives the second communication message sent by the first CSCF device, and routes the first call signaling to the roaming AS of the roaming user equipment based on the second communication message.

[0177] Illustratively, a second CSCF device in the home region of the first CSCF device determines, based on the first indication information included in the second communication message, that the calling party or called party of the first call signaling is a roaming user equipment of the first CSCF device, and transmits the second communication message to the roaming AS of the roaming user equipment. Furthermore, as described above, in order to subsequently route other call signaling of the call service to the roaming AS, the second CSCF device in the home region of the first CSCF device may store the first indication information in association with the call service or communication session corresponding to the first call signaling.

[0178] Since the calling party or called party of the first call signaling is a roaming user equipment of the first CSCF device, and the HSS in the home area of ​​the first CSCF device does not have the subscription information or registration information of the roaming user equipment, when the second CSCF device receives the second communication message, it no longer performs signaling interaction with the HSS to authenticate the roaming user equipment. Instead, the second CSCF device directly performs initial filter criteria (iFC) triggering logic. For example, the second CSCF device may traverse each AS in the home area of ​​the first CSCF device and, based on the header field or message content of the received second communication message, check whether the second communication message meets the triggering condition provided by the AS in the home area of ​​the first CSCF device (i.e., the roaming AS of the roaming user equipment). In other words, it performs iFC determination. If the second communication message meets the triggering condition, the second communication message is sent to the AS in the home area of ​​the first CSCF device to trigger the AS in the home area of ​​the first CSCF device to provide the value-added call service to the roaming user equipment. If the second communication message meets the triggering condition, the second CSCF device does not send the second communication message, and does not trigger the AS in the home area of ​​the first CSCF device to provide the value-added call service.

[0179] The process by which the second CSCF device checks, based on the header fields or message content of the second communication message, whether the second communication message satisfies the trigger conditions set by the AS in the home domain of the first CSCF device can be referred to in the prior art and will not be described in detail. For example, if a roaming user device subscribes to the instant messaging service, any field or message body content of the SIP message sent by the roaming user device, or any combination thereof, may satisfy the trigger conditions corresponding to the instant messaging server.

[0180] It should be noted that the process shown in S402(b)-S402(c) can be applied to the scenario where the first CSCF device and the second CSCF device are separated. Alternatively, when the second CSCF device is centrally deployed on the first CSCF device, S402(b)-S402(c) can be replaced by the first CSCF device directly sending the second communication message to the roaming AS of the roaming device. After the first CSCF device receives the first communication message and determines that the calling party or called party of the first call signaling is a roaming user device based on the first communication message, it performs iFC triggering logic and determines, based on the header field or message content of the first communication message, which AS in the home area of ​​the first CSCF device satisfies the triggering condition of the first communication message. The second communication message is then sent to the AS to trigger the AS to provide the value-added call service.

[0181] S403: The roaming AS of the roaming user equipment (ie, the AS in the home area of ​​the first CSCF device) receives the second communication message, and provides a value-added call service for the roaming user equipment based on the second communication message.

[0182] The manner in which the roaming AS of the roaming user equipment provides the call value-added service to the roaming user equipment based on the second communication message may be the following manner 1 or manner 2:

[0183] Method 1: The roaming AS of the roaming user device determines that the caller or called party of the first call signaling is the roaming user device based on the first indication information in the second communication message. If the roaming AS determines, based on the service priority processing policy, that the roaming AS shall prioritize providing the call value-added service to the roaming user device, then before connecting the call, the roaming AS provides the call value-added service to the roaming user device, completing the roaming service logic with the roaming user device. For example, the roaming AS may establish a media channel with the roaming user device before connecting the call, and provide the media stream corresponding to the call value-added service to the roaming user device through the media channel, triggering the roaming user device to present media content, game content, etc. on the APP interface related to the call service corresponding to the first call signaling, thereby using the call value-added service.

[0184] In method 1, the roaming AS can provide value-added call services to the roaming user device before or during the call connection. For example, if the caller is a roaming user device, the call service is a voice call, and the value-added call service is a ringback tone service, the roaming AS can provide the ringback tone service to the caller between the time the caller dials the phone number and the time the called party rings.

[0185] Specifically, the call connection may refer to the process from the roaming AS sending the first call signaling to the called party to the first call signaling arriving at the called party. In the case where the roaming user equipment is the calling party, the call connection may include: Figure 5 As shown in S504-S507. If the incoming user equipment is the called party of the first call signaling, the call connection may include: the roaming AS of the incoming user equipment sends the first call signaling to the first CSCF device or a second CSCF device in the home area of ​​the first CSCF device. The first CSCF device or the second CSCF device in the home area of ​​the first CSCF device receives the first call signaling and sends it to the called party, thus completing the call connection.

[0186] Specifically, the service priority policy can be used to define the priority of providing value-added services between the roaming AS and the home AS. It can be used to determine whether the roaming AS prioritizes providing value-added services to roaming user devices, or whether the home AS prioritizes providing value-added services to roaming user devices. The service priority policy can be pre-configured in the roaming AS or the home AS of the roaming user device, or the roaming AS can obtain it from other devices, such as the HSS.

[0187] Method 2: The roaming AS of the roaming user equipment determines that the caller or called party of the first call signaling is the roaming user equipment based on the first indication information in the second communication message. If the roaming AS determines, based on the service priority processing strategy, that the roaming AS shall give priority to providing the call value-added service to the roaming user equipment, the call value-added service will be provided to the roaming user equipment. It should be understood that at this time, the roaming AS can perform preparatory work such as transmitting configuration information for providing the call value-added service, and does not provide the call value-added service to the roaming user equipment.

[0188] Furthermore, the roaming AS sends a third communication message to the first CSCF device or a second CSCF device in the home area of ​​the first CSCF device to connect the call. The third communication message includes the first call signaling, the first indication information, and the second indication information. The second indication information is used to indicate that the roaming AS will provide a value-added call service for the roaming user equipment. It should be noted that the second indication information may or may not be included in the third communication message, without limitation.

[0189] After the call connection is completed, a fifth communication message is sent from the third CSCF device in the home area of ​​the roaming user equipment to the first CSCF device or the second CSCF device in the home area of ​​the first CSCF device. The fifth communication message includes the first indication information. The first CSCF device or the second CSCF device in the home area of ​​the first CSCF device sends a sixth communication message to the roaming AS based on the first indication information. The sixth communication message includes the first indication information and the third indication information. The roaming AS receives the sixth communication message from the first CSCF device or the second CSCF device in the home area of ​​the first CSCF device. The sixth communication message includes the first indication information. It should be noted that the first CSCF device or the second CSCF device in the home area of ​​the first CSCF device can send the sixth communication message directly to the roaming AS or send the sixth communication message to the roaming AS through an intermediate device without limitation.

[0190] Furthermore, if the AS of the home location of the roaming user equipment determines, based on the service priority policy, that the AS of the home location shall give priority to providing the call value-added service to the roaming user equipment, the fifth communication message and the sixth communication message may also include third indication information, and the third indication information is used to indicate that the AS of the home location of the roaming user equipment will provide the call value-added service to the roaming user equipment; conversely, if the AS of the home location of the roaming user equipment determines, based on the service priority policy, that the AS of the roaming location shall give priority to providing the call value-added service to the roaming user equipment, the fifth communication message and the sixth communication message do not include the third indication information.

[0191] Furthermore, the sixth communication message received by the roaming AS includes the third indication information. The roaming AS then determines whether the roaming AS should provide the call value-added service to the roaming user equipment on a priority basis according to the service priority processing strategy and the third indication information. If so, the call value-added service is provided to the roaming user equipment; if not, it is not provided.

[0192] Furthermore, as described above, in order to subsequently route other call signaling of the call service to the roaming AS, the roaming AS may store the first indication information in correspondence with the call service or communication session corresponding to the first call signaling.

[0193] based on Figure 4The method shown, when determining that the calling party or called party of a first call signaling is a roaming user equipment of a first CSCF device, routes the first call signaling to the roaming AS of the roaming user equipment, and the roaming AS of the roaming user equipment provides the roaming user equipment with a value-added call service. Because a user equipment roaming outside its home area is relatively close to its roaming AS, the roaming AS of the roaming user equipment provides the user equipment with a value-added call service. Due to the close distance between the roaming user equipment and the roaming AS, the end-to-end latency between the roaming user equipment and the roaming AS is low, thereby improving the user experience. Furthermore, in the call method provided in the embodiments of the present application, the application server can provide value-added call services not only for local callers, but also for roaming user equipment roaming in its home area, thereby increasing the opportunities for the AS to provide services to the caller and improving network resource utilization.

[0194] The following combination Figure 5 For example, the calling party of the first call signaling is a roaming user device, and the roaming AS of the roaming user device has provided the roaming user device with a call value-added service before the call is connected. Figure 4 The connection process when the called party of the first call signaling is a roaming user equipment can refer to the existing technology and will not be described in detail.

[0195] Figure 5 A flowchart of a calling method provided in an embodiment of the present application, the method comprising S501-S507:

[0196] Execute S501-S503. Figure 4 S401-S403 are the same and will not be described in detail.

[0197] S504: The roaming AS of the roaming user equipment sends a third communication message to the second CSCF device in the home area of ​​the first CSCF device.

[0198] The third communication message may include the first call signaling, the first indication information, and other existing header fields or messages.

[0199] During the call connection process, the AS in the home region of the roaming user device may be triggered to provide a value-added call service for the roaming user device. Furthermore, to avoid service conflicts caused by both the AS in the roaming area of ​​the roaming user device and the AS in the home region of the roaming user device providing the value-added call service for the roaming user device, the third communication message may further include second indication information to indicate that the AS in the roaming region of the roaming user device has already provided the value-added call service for the roaming user device. This allows the AS in the home region of the roaming user device to learn, based on the second indication information, that the AS in the roaming region of the roaming user device has already provided the value-added call service for the roaming user device, without triggering the home region service process.

[0200] Specifically, the name of the second indication information is not limited and may be called "service identifier," "flag2," or "roaming service identifier." If the roaming AS has already provided a value-added service to the roaming user equipment before configuring the second indication information, the second indication information may, as described above, indicate that the roaming AS has already provided the value-added service to the roaming user equipment. If the roaming AS has determined that the value-added service may be provided to the roaming user equipment and is preparing to provide the value-added service before configuring the second indication information, the second indication information may be used to instruct the roaming AS to provide the value-added service to the roaming user equipment. Similarly, referring to the function of the first indication information, if the home AS or another AS also determines that the value-added service may be provided to the roaming user equipment, the home AS or other AS may also allocate indication information, such as third indication information, indicating that the home AS or other AS will provide the value-added service to the roaming user equipment. This third indication information allows the AS that receives the third indication information to be informed of the provision of the value-added service by the home AS or other AS and to take appropriate measures to avoid service conflicts.

[0201] Taking the second indication information as an example, it should be understood that the second indication information is essentially a type of "service indication information" that can avoid service conflicts between the home AS or other AS in the home area of ​​the roaming user device and the roaming AS. For example, in an embodiment of the present application, the second indication information can be routed to the home AS or other AS in the home area of ​​the roaming user device according to the call route of the first call signaling. For example, a device on the call route of the first call signaling can carry the second indication information in a communication message and route it to the home AS or other AS in the home area of ​​the roaming user device. This allows the home AS or other AS to learn, based on the second indication information, that the roaming AS provides value-added call services for the roaming user device, thereby avoiding service conflicts with the roaming AS.

[0202] Specifically, each device on the call route of the first call signaling can carry the second indication information in a communication message (such as a third communication message or other communication message) using the following method 1, method 2, or method 3:

[0203] Method 1: Carry the second indication information through a new header field in the communication message. For example, the new header field may be an input service indication header field (P-visited-service-indication).

[0204] Method 2: Carry the second indication information through the attributes of the existing header field in the communication message. For example, the service code (service-code) is included in the attributes of the existing P-Asserted-Service-Info header field. The value of the service-code can indicate that the roaming AS of the roaming user equipment has provided the call value-added service for the roaming user equipment.

[0205] Method three: the second indication information is carried in the message body of the communication message. For example, the second indication information is added to the media description attribute line of the session description information in the message body: a=g.3gpp.rmas.

[0206] S505: The second CSCF device in the home zone of the first CSCF device receives the third communication message, and sends a fourth communication message to the second CSCF device in the home zone of the roaming user equipment.

[0207] Specifically, the second CSCF device in the home zone of the roaming user equipment may be an I-CSCF device or an S-CSCF device in the home zone of the roaming user equipment.

[0208] The fourth communication message in S505 may include the content included in the third communication message, such as the first call signaling, the first indication information, and the second indication information.

[0209] Illustratively, a second CSCF device in the home area of ​​the first CSCF device may determine the home area of ​​the roaming user device based on the number segment of the roaming user device, obtain the subscription information of the roaming user device from the HSS in the home area of ​​the roaming user device, determine a third CSCF device in the home area of ​​the roaming user device based on the subscription information of the roaming user device, and send the fourth communication message to the third CSCF device in the home area. In this embodiment of the present application, the third CSCF device may include an I-CSCF device or an S-CSCF device in the home area of ​​the roaming user device, or other device capable of receiving the fourth communication message and routing the fourth communication message to the home AS.

[0210] Furthermore, as described above, in order to subsequently route other call signaling of the call service to the roaming AS according to the call route, the third CSCF device in the home area of ​​the roaming user equipment can store the first indication information and the call service or communication session corresponding to the first call signaling.

[0211] S506: The third CSCF device in the home area of ​​the roaming user equipment receives the fourth communication message and sends a seventh communication message to the home AS of the roaming user equipment.

[0212] Exemplarily, the home AS of the roaming user equipment receives the seventh communication message, interacts with the HSS in the home area to obtain the iFC triggering condition of the home AS; checks whether the seventh communication message meets the iFC triggering condition of the home AS, and if so, sends the seventh communication message to the home AS.

[0213] Furthermore, in order to subsequently transmit other call signaling of the call service to the roaming AS according to the call route, the home AS of the roaming user equipment may store the first indication information and the call service or communication session corresponding to the first call signaling in correspondence.

[0214] S507: The home AS of the roaming user device receives the seventh communication message and, in response to the seventh communication message, learns based on the second indication information in the seventh communication message that the roaming user device's roaming AS has already provided the roaming user device with a value-added call service. The home AS does not trigger the home service process. Furthermore, the home AS of the roaming user device clears the first call signaling, routes the first call signaling sent by the calling party to the called party, completes the call connection, and simultaneously completes the call route traversed by the call signaling for the call service.

[0215] It should be noted that if the roaming AS of the incoming user equipment did not provide the value-added service to the incoming user equipment before the call was connected by the roaming AS, but instead determined that it was prepared or planned to provide the value-added service to the incoming user equipment, the second indication information included in the third communication message sent by the roaming AS may be used to indicate that the roaming AS will provide the value-added service to the incoming user equipment. Subsequently, upon receiving the second indication information, the home AS may determine, based on its service priority processing policy, whether it should prioritize providing the value-added service to the roaming user equipment or whether the roaming AS should prioritize providing the service. If the home AS prioritizes the service, the home AS replaces / overwrites the second indication information with the third indication information and feeds the third indication information back to the roaming AS. This allows the roaming AS's service priority processing policy and the third indication information to ultimately determine whether the roaming AS or the home AS will provide the service. Conversely, if the roaming AS prioritizes the service, the home AS does not trigger the home service process and connects the call.

[0216] Furthermore, the method further includes: the home AS of the roaming user equipment routes the first call signaling or the second call signaling of the call service corresponding to the first call signaling to the roaming AS based on the seventh communication message:

[0217] For example, if the caller of the first call signaling is a roaming user device of the first CSCF device, and the home AS prioritizes providing value-added call services, after the home AS of the roaming user device receives the second call signaling / subsequent call signaling (e.g., a response message to an Invite message) for the call service from the called party, it sends an eighth communication message containing the second call signaling, the first indication information, and the third indication information to a third CSCF device in the home area of ​​the roaming user device based on the first indication information in the seventh communication message. The third indication information indicates that the second AS will provide the value-added call service for the roaming user device. If the caller of the first call signaling is a roaming user device of the first CSCF device, and the roaming AS prioritizes providing value-added call services, after the home AS of the roaming user device receives the second call signaling / subsequent call signaling (e.g., a response message to an Invite message) for the call service from the called party, it sends an eighth communication message containing the second call signaling and the first indication information to the third CSCF device based on the first indication information in the seventh communication message.

[0218] For another example, if the called party in the first call signaling is a roaming user device of the first CSCF device, and the home AS prioritizes providing value-added call services, the home AS of the roaming user device sends an eighth communication message containing the first call signaling for the call service, the first indication information, and the third indication information to a third CSCF device in the home area of ​​the roaming user device based on the first indication information in the seventh communication message. The third indication information indicates that the second AS will provide the value-added call service for the roaming user device. For another example, if the called party in the first call signaling is a roaming user device of the first CSCF device, and the roaming AS prioritizes providing value-added call services, after receiving the first call signaling / subsequent call signaling for the call service from the called party (such as a response message to an Invite message), the home AS of the roaming user device sends an eighth communication message containing the first call signaling for the call service and the first indication information to the third CSCF device based on the first indication information in the seventh communication message.

[0219] Furthermore, the third CSCF device in the home area of ​​the roaming user equipment determines that the call service corresponds to the first indication information based on the correspondence between the stored first indication information and the call service or communication session, and routes the content contained in the eighth communication message to the P-CSCF device or I-CSCF device / S-CSCF device in the roaming area of ​​the roaming user equipment according to the first indication information.

[0220] The following combination Figure 6 The flow diagram of the invite message is shown in Figure 4 The method shown is described, where it is assumed that the calling party of the first call signaling is UE1, UE1 calls UE2, UE1's home area is area 1, UE1 is currently roaming to area 2, and UE2's home area is area 3. The indication information used to indicate that the calling party of the first call signaling is a roaming user equipment is named network identifier, and the indication information used to instruct the AS to provide a call value-added service for the roaming user equipment is named service identifier. Figure 6 The message flow shown includes the following processes:

[0221] (1) UE1 sends an invite message to the P-CSCF device in area 2.

[0222] (2) The P-CSCF device determines that UE1 is an incoming user equipment based on the From header field of the Invite message, allocates network ID 1, and sends network ID 1 and the Invite message to the I-CSCF device / S-CSCF device in area 2.

[0223] (3) The I-CSCF device in area 2 sends the received network ID 1 and invite message to the S-CSCF device. The S-CSCF device in area 2 completes the iFC trigger logic and sends the network ID 1 and invite message to AS1 in area 2 that meets the iFC trigger conditions.

[0224] (4) AS1 receives the network identifier 1 and the invite message, determines to provide the value-added call service for the roaming user equipment, allocates the service identifier 1 used to identify that AS1 will provide the value-added call service for UE1, and sends the network identifier 1, service identifier 1 and the invite message to the I-CSCF device / S-CSCF device in area 2.

[0225] (5) The I-CSCF device / S-CSCF device in area 2 receives the network identifier 1, service identifier 1, and invite message, and sends the network identifier 1, service identifier 1, and invite message to the I-CSCF device / S-CSCF device in area 1.

[0226] (6) The I-CSCF device in area 1 sends the received network ID 1, service ID 1, and invite message to the S-CSCF device in area 1. The S-CSCF device in area 1 completes the iFC trigger logic and sends the network ID 1, service ID 1, and invite message to AS2 in area 1 that meets the iFC trigger conditions.

[0227] (7) AS2 in area 1 that meets the iFC triggering conditions receives network ID 1, service ID 1, and an invite message. If, according to the service priority processing policy, AS2 is determined to prioritize providing the value-added call service to UE1, it replaces service ID 1 with service ID 2. Service ID 2 is used to indicate that AS2 will provide the value-added call service to UE1, and sends network ID 1, service ID 2, and an invite message to the I-CSCF device / S-CSCF device in area 1. Conversely, if, according to the service priority processing policy, AS1 is determined to prioritize providing the value-added call service to UE1, it sends network ID 1, service ID 1, and an invite message to the I-CSCF device / S-CSCF device in area 1.

[0228] ⑻ The I-CSCF device / S-CSCF device in area 1 receives network ID 1, service ID 2, and the invite message, and sends the invite message to UE2, completing the call connection. Subsequently, network ID 1, service ID 2 / service ID 1 are routed to AS1 in UE1's roaming area. AS1 ultimately determines whether AS1 or AS2 will provide the value-added call service based on service ID 2 / service ID 1 and the service priority processing policy. This allows UE1 to establish a media channel with the AS that ultimately provides the value-added call service, and receive and present the value-added call service.

[0229] above Figure 6 The calling method provided by the present application is described by taking the case where the calling party of the first call signaling roams to an area outside the home area / registration area as an example. Similarly, when the called party roams to an area outside the home area / registration area, the calling method provided by the present application can be described by referring to Figure 4 The method shown here routes the first call signaling sent to the called party to the IMS network in the called party's roaming area, and the AS in the called party's roaming area (ie, the called party's roaming AS) provides the called party with a value-added call service.

[0230] The following combination Figure 7The flow diagram of the invite message shown describes the processing flow when the called party is in a roaming area. It is assumed that the called party of the first call signaling is UE1, UE3 calls UE1, UE1's home area is area 1, and UE1 is currently roaming to area 2. The indication information used to indicate that the called party of the first call signaling is a roaming user equipment is named network identifier, and the indication information used to instruct the AS to provide a call value-added service for the called party is named service identifier. Figure 7 The message flow shown includes the following processes:

[0231] ①: UE3 sends an invite message to the I-CSCF device / S-CSCF device in area 1, which is the home area of ​​UE1.

[0232] ②: The I-CSCF device / S-CSCF device in area 1 receives the invite message, completes the iFC triggering logic, and sends an invite message to the AS3 in area 1 that meets the iFC triggering conditions.

[0233] ③: The AS that meets the iFC triggering conditions in area 1 receives the invite message, allocates service ID 3 if it determines to provide the value-added call service to UE1, and sends the service ID 3 and the invite message to the I-CSCF device / S-CSCF device in area 1.

[0234] ④: The I-CSCF device / S-CSCF device in area 1 receives the service identifier 3 and the invite message, and sends the service identifier 3 and the invite message to the P-CSCF device in area 2.

[0235] ⑤: The P-CSCF device in area 2 receives service ID 3 and the invite message, determines that UE1 is a roaming user equipment based on the to header field of the invite message, allocates network ID 2, and sends network ID 2, service ID 3, and the invite message to the I-CSCF device in area 2.

[0236] ⑥: The I-CSCF in area 2 sends the received network ID 2, service ID 3, and invite message to the S-CSCF. The S-CSCF in area 2 completes the iFC trigger logic and sends the network ID 2, service ID 3, and invite message to the AS4 in area 2 that meets the iFC trigger conditions.

[0237] ⑦: AS4 in area 2 receives network ID 2, service ID 3, and the invite message. Based on service ID 3 and the service priority processing policy, it ultimately determines whether AS3 or AS4 will provide the value-added service. UE1 then establishes a media channel with the AS providing the value-added service, receiving and presenting the service. Simultaneously, AS4 sends the invite message to the I-CSCF / S-CSCF in area 2.

[0238] ⑧: The I-CSCF device / S-CSCF device in area 2 receives the invite message and sends an invite message to the P-CSCF device in area 2.

[0239] ⑨: The P-CSCF device in area 2 receives the invite message and sends an invite message to UE1 to complete the call connection.

[0240] The following combination Figure 3 The illustrated architecture describes the process by which the calling party's roaming AS provides a value-added call service to the calling party. It is assumed that the first call signaling is an invite message, the calling party is UE1, the called party is UE2, UE1 is in the roaming area, UE2 is in the home area, and AS1 in UE1's roaming area provides the value-added call service to UE1.

[0241] Figure 8 A flowchart of a calling method provided in an embodiment of the present application, the method comprising:

[0242] S801: UE1 sends an invite message to a P-CSCF device in the roaming area.

[0243] S802: The P-CSCF device determines that UE1 is a roaming user equipment according to the from header field in the invite message.

[0244] The process of the P-CSCF device determining that UE1 is a roaming user device based on the from header field in the invite message can be referred to Figure 4 The corresponding embodiments are described in detail and will not be described in detail here.

[0245] S803: The P-CSCF device determines, based on the configuration policy and / or the capability information of UE1, that UE1 is capable of using the call value-added service provided by the AS in the roaming area, and allocates first indication information, where the first indication information is used to indicate that UE1 is a roaming user equipment.

[0246] The specific process of the P-CSCF device determining that UE1 has the capability to use the call value-added service provided by the AS in the roaming area according to the configuration policy and / or the capability information of UE1 can be referred to in Figure 4 The corresponding embodiments are described in detail and will not be described in detail here.

[0247] S804: The P-CSCF device sends an invite message and first indication information to the I-CSCF device / S-CSCF device in the home area of ​​the P-CSCF device.

[0248] In S804, the invite message and the first indication information may be included in the same communication message and sent to the I-CSCF device / S-CSCF device in the home area of ​​the P-CSCF device. For example, the invite message and the first indication information may be respectively carried in different header fields in the communication message and sent to the I-CSCF device / S-CSCF device in the home area of ​​the P-CSCF device.

[0249] For example, the P-CSCF device may send an invite message and the first indication information to the I-CSCF device / S-CSCF device with the smallest load or a load less than a preset threshold among multiple I-CSCF devices / S-CSCF devices in the P-CSCF device's home area. Figure 4 The corresponding embodiments are described in detail and will not be described in detail here.

[0250] S805: The I-CSCF device / S-CSCF device receives the invite message and the first indication information, determines based on the first indication information that the invite message is an invite message initiated by the roaming user equipment, executes the iFC trigger logic, and sends the invite message and the first indication information to the AS1 in the home area of ​​the P-CSCF device that meets the iFC trigger logic.

[0251] S806: AS1 receives the invite message and the first indication information, determines based on the first indication information that the invite message is an invite message initiated by the roaming user equipment, and determines based on the service priority processing policy that the AS in the roaming area shall prioritize providing call value-added services to the roaming user equipment. Then, AS1 completes the roaming service logic between AS1 and UE1.

[0252] Further, execute the following S807-S811 to complete the call connection. During the call connection process, the AS of UE1's home region may be triggered to provide value-added call services for UE1. In order to avoid the service conflict caused by the AS of UE1's home region and the AS in UE1's roaming area providing value-added call services to UE1 at the same time, AS1 in the roaming area also needs to allocate second indication information and route the second indication information to UE1's home region AS during the call connection process. The second indication information can be used to indicate that AS1 has provided value-added call services for UE1, so that the AS of the home region determines that AS1 has provided value-added call services for UE1 based on the second indication information, without triggering the home region service processing process.

[0253] S807: AS1 allocates second indication information, which is used to indicate that AS1 has provided a value-added call service for UE1, and sends an invite message, the first indication information, and the second indication information to the I-CSCF device / S-CSCF device in the home area of ​​the P-CSCF device.

[0254] S808: The I-CSCF device / S-CSCF device in the home area of ​​the P-CSCF device receives the invite message, the first indication information, and the second indication information, and sends the invite message, the first indication information, and the second indication information to the I-CSCF device / S-CSCF device in the home area of ​​UE1 according to the first indication information.

[0255] S809: The I-CSCF device / S-CSCF device in the home area of ​​UE1 receives the invite message, the first indication information, and the second indication information, executes the iFC trigger logic, and sends the invite message, the first indication information, and the second indication information to AS2 in the home area of ​​UE1 that meets the iFC trigger logic.

[0256] S810: AS2 receives the invite message, the first indication information and the second indication information. According to the second indication information, the AS of the home area determines that AS1 has provided the call value-added service for UE1, does not trigger the home area service processing flow, and sends the invite message and the first indication information to the I-CSCF device / S-CSCF device in the home area of ​​UE1.

[0257] S811: The I-CSCF device / S-CSCF device in the home area of ​​UE1 receives the invite message and the first indication information from AS2, and sends an invite message to the I-CSCF device / S-CSCF device in the home area of ​​UE2 according to the to header field in the invite message to complete the call connection.

[0258] The call connection process may include: the I-CSCF device / S-CSCF device in the home area of ​​UE2 receives the invite message, executes the iFC trigger logic, and sends the invite message to the AS in the home area of ​​UE2 that meets the iFC trigger logic;

[0259] The AS of UE2's home region receives the invite message and, if it determines to provide the call value-added service for UE2, completes the home region service logic with UE2.

[0260] UE2's home AS sends an invite message to the I-CSCF device / S-CSCF device in UE2's home area. The I-CSCF device / S-CSCF device in UE2's home area receives the invite message and sends an invite message to the P-CSCF device in UE2's home area. The P-CSCF device in UE2's home area receives the invite message and sends an invite message to UE2.

[0261] Furthermore, after receiving the invite message, UE2 returns a response message corresponding to the invite message to UE1. Exemplarily, UE2 may return a response message corresponding to the invite message to UE1 according to the sending path of the invite message.

[0262] based on Figure 8 In the method shown, after UE1 initiates an invite message in the roaming area, the P-CSCF device in UE1's roaming area can route the invite message initiated by UE1 to the IMS network in UE1's roaming area, and the AS in UE1's roaming area provides UE1 with a value-added call service. At the same time, to avoid service conflicts caused by the AS in UE1's roaming area and the AS in the home area simultaneously providing value-added call services to UE1, second indication information allocated by the AS in UE1's roaming area is sent to the AS in the home area during the call connection process. The AS in the home area can then determine, based on the second indication information, that AS1 has already provided the value-added call service for UE1, without triggering the home area service processing flow.

[0263] Figure 8 The calling method provided by this application is described by taking the AS in the roaming area as an example to provide the call value-added service to UE1 first. In a possible design, in the embodiment of this application, the home AS can also provide the call value-added service to UE1 first. Figure 3The architecture shown describes the processing flow of the caller's home AS providing call value-added services to the caller, assuming that the first call signaling is an invite message, the caller is UE1, the called party is UE2, UE1 calls UE2, UE1 is in the roaming area, UE2 is in the home area, and the home AS gives priority to providing call value-added services to UE1.

[0264] Figure 9 A flowchart of a calling method provided in an embodiment of the present application, the method comprising:

[0265] S901: UE1 sends an invite message to a P-CSCF device in the roaming area.

[0266] S902: The P-CSCF device determines that UE1 is a roaming user equipment according to the from header field in the invite message.

[0267] The process of the P-CSCF device determining that UE1 is a roaming user device based on the from header field in the invite message can be referred to Figure 4 The corresponding embodiments are described in detail and will not be described in detail here.

[0268] S903: The P-CSCF device determines, based on the configuration policy and / or the capability information of UE1, that UE1 is capable of using the call value-added service provided by the AS in the roaming area, and allocates first indication information, where the first indication information is used to identify UE1 as a roaming user equipment.

[0269] The specific process of the P-CSCF device determining that UE1 has the capability to use the call value-added service provided by the AS in the roaming area according to the configuration policy and / or the capability information of UE1 can be referred to in Figure 4 The corresponding embodiments are described in detail and will not be described in detail here.

[0270] S904: The P-CSCF device sends an invite message and first indication information to the I-CSCF device / S-CSCF device in the home area of ​​the P-CSCF device.

[0271] In S904, the invite message and the first indication information may be included in the same communication message and sent to the I-CSCF device / S-CSCF device in the home area of ​​the P-CSCF device.

[0272] For example, the P-CSCF device may send an invite message and the first indication information to the I-CSCF device / S-CSCF device with the smallest load or a load less than a preset threshold among multiple I-CSCF devices / S-CSCF devices in the P-CSCF device's home area. Figure 4The corresponding embodiments are described in detail and will not be described in detail here.

[0273] S905: The I-CSCF device / S-CSCF device receives the invite message and the first indication information, determines based on the first indication information that the invite message is an invite message initiated by the roaming user equipment, executes the iFC trigger logic, and sends the invite message and the first indication information to the AS1 in the home area of ​​the P-CSCF device that meets the iFC trigger logic.

[0274] S906: AS1 receives the invite message and the first indication information, determines based on the first indication information that it is not going to provide the call value-added service for the roaming user equipment, and sends the invite message and the first indication information to the I-CSCF device / S-CSCF device in the home area of ​​the P-CSCF device.

[0275] S907: The I-CSCF device / S-CSCF device in the home area of ​​the P-CSCF device receives the invite message and the first indication information, and sends the invite message and the first indication information to the I-CSCF device / S-CSCF device in the home area of ​​UE1 according to the first indication information.

[0276] S908: The I-CSCF device / S-CSCF device in the home area of ​​UE1 receives the invite message and the first indication information, executes the iFC trigger logic, and sends the invite message and the first indication information to AS2 in the home area of ​​UE1 that meets the iFC trigger logic.

[0277] S909: AS2 receives the invite message and the first indication information, and determines, based on the service priority processing policy, that UE1's home AS2 preferentially provides the call value-added service to the roaming user equipment UE1. Furthermore, AS2 completes the home service logic between UE1 and AS2.

[0278] The completion of the home service logic between AS2 and UE1 may include: UE1's home AS2 may establish a media channel with the user equipment, provide the user equipment with a media stream corresponding to the call value-added service through the media channel, and trigger the user equipment to provide a call value-added service such as media content or game content on the APP interface related to the call service corresponding to the first call signaling. UE1's home AS2 may establish a media channel with the user equipment at the start of a call service, during a call service, or at the end of a call service. This process can be referred to in the prior art and is not described in detail here.

[0279] It should be noted that, in order to avoid the service conflict caused by the AS in UE1's roaming area and the AS in UE1's home area providing value-added call services to UE1 at the same time when the first call signaling or other call signaling related to the call service initiated by UE1 is routed to AS1 in UE1's roaming area, AS2 sends first indication information and third indication information indicating that AS2 will provide value-added call services to UE1 to the I-CSCF device / S-CSCF device in UE1's home area. Based on the first indication information, the I-CSCF device / S-CSCF device in UE1's home area sends the first indication information and the third indication information indicating that AS2 will provide value-added call services to UE1 to the AS in UE1's roaming area via the I-CSCF device / S-CSCF device in UE1's roaming area. The AS in UE1's roaming area determines the service priority and, after determining that the value-added call service is provided by the AS in the home area, does not trigger the roaming service processing procedure. Specifically, the process may include the following S910 to S911:

[0280] S910: AS2 sends an invite message, first indication information, and third indication information to the I-CSCF device / S-CSCF device in the home area of ​​UE1.

[0281] The third indication information is used to instruct AS2 to provide a value-added call service for UE1.

[0282] S911: The I-CSCF device / S-CSCF device in the home area of ​​UE1 receives the invite message, the first indication information, and the third indication information from AS2, and sends an invite message to the I-CSCF device / S-CSCF device in the home area of ​​UE2 according to the to header field in the invite message to complete the call connection.

[0283] The call connection process may include: the I-CSCF device / S-CSCF device in the home area of ​​UE2 receives the invite message, executes the iFC trigger logic, and sends the invite message to the AS in the home area of ​​UE2 that meets the iFC trigger logic.

[0284] The AS of UE2's home region receives the invite message and, if it determines to provide the call value-added service for UE2, completes the home region service logic with UE2. This process can be referred to the existing technology and will not be described in detail.

[0285] UE2's home AS sends an invite message to the I-CSCF / S-CSCF in UE2's home area. The I-CSCF / S-CSCF in UE2's home area receives the invite message and sends an invite message to the P-CSCF in UE2's home area. The P-CSCF in UE2's home area receives the invite message and sends it to UE2.

[0286] Furthermore, after receiving the invite message, UE2 returns a response message corresponding to the invite message to UE1. Exemplarily, UE2 may return a response message corresponding to the invite message to UE1 according to the sending path of the invite message.

[0287] For example, UE2 sends a response message corresponding to the invite message to the P-CSCF device in UE2's home area, the P-CSCF device in UE2's home area sends a response message corresponding to the invite message to the I-CSCF device / S-CSCF device in UE2's home area, the I-CSCF device / S-CSCF device in UE2's home area sends a response message corresponding to the invite message to the I-CSCF device / S-CSCF device in UE1's home area, and the I-CSCF device / S-CSCF device in UE1's home area sends a response message corresponding to the invite message, the first indication information, and the third indication information to the I-CSCF device / S-CSCF device in UE1's roaming area based on the first indication information. The I-CSCF device / S-CSCF device in UE1's roaming area receives the response message, first indication information, and third indication information corresponding to the invite message, returns the response message corresponding to the invite message to the roaming user equipment based on the first indication information, and sends the response message, first indication information, and third indication information corresponding to the invite message to AS1 in UE1's roaming area. Based on the service priority processing policy and the third indication information, AS1 in UE1's roaming area determines that the home AS should prioritize providing the value-added call service, and does not trigger the roaming service processing flow.

[0288] based on Figure 9In the method shown, after UE1 initiates an invite message in the roaming area, the P-CSCF device in the roaming area can route the invite message initiated by UE1 to the IMS network in UE1's roaming area, and the AS in the roaming area determines whether to provide the value-added service for UE1. At the same time, to avoid service conflicts caused by the AS in the roaming area and the AS in the home area simultaneously providing the value-added service to UE1, third indication information allocated by the AS in the home area is sent to the AS in the roaming area during the process of returning the response message corresponding to the invite message to UE1. This allows the AS in the roaming area to determine, based on the third indication information and the service priority processing policy, that the AS in the roaming area should prioritize providing the value-added service, without triggering the roaming service processing process.

[0289] The above mainly introduces the solution provided by the embodiment of the present application from the perspective of the interaction between each node. It can be understood that, in order to implement the above functions, each node, such as the key management network element, includes a hardware structure and / or software module corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the algorithm steps of each example described in the embodiments disclosed herein, the method of the embodiment of the present application can be implemented in the form of hardware, software, or a combination of hardware and computer software. Whether a function is executed in a hardware or computer software-driven hardware manner depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0290] In the embodiment of the present application, the key management network element can be divided into functional modules according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical functional division. In actual implementation, there may be other division methods.

[0291] Figure 10 The structure diagram of a device 100 is shown. The device 100 can be a first CSCF device, a chip in the first CSCF device, a system on chip, or other devices capable of implementing the functions of the first CSCF device in the above method. The device 100 can be used to perform the functions of the first CSCF device involved in the above method embodiment. As an implementation method, Figure 10 The device 100 shown includes: a receiving unit 1001, a processing unit 1002;

[0292] The receiving unit 1001 is configured to receive a first communication message, the first communication message including a first call signaling, the initiator or receiver of the first call signaling being a roaming user equipment of a first CSCF device. For example, the receiving unit 1001 may be configured to support the apparatus 100 in executing S401, S802, and S902.

[0293] Processing unit 1002 is configured to route the first call signaling to a roaming AS of the roaming user equipment based on the first communication message. The roaming AS is an AS in the home area of ​​the first CSCF device that is capable of providing a value-added call service to the user equipment. For example, processing unit 1002 may be configured to support apparatus 100 in executing S402, S802-S804, and S902-S904.

[0294] Specifically, the above Figure 4-Figure 9 All relevant contents of each step involved in the embodiment of the method shown can be referred to the functional description of the corresponding functional module, and will not be repeated here. Figure 4-Figure 9 The method shown in the figure implements the function of the first CSCF device in the calling method shown in the figure, and thus can achieve the same effect as the above-mentioned calling method.

[0295] In this embodiment, the device 100 can also be presented in the form of various functional modules divided in an integrated manner. The "functional module" here can refer to an application specific integrated circuit (ASIC), a circuit, a processor and memory that executes one or more software or firmware programs, an integrated logic circuit, and / or other devices that can provide the above functions. In a simple embodiment, those skilled in the art can imagine that the functions / implementation processes of the processing unit 1001 in the device 100 can be implemented by the processor calling computer-executable instructions stored in the memory. Figure 10 The function / implementation process of the transceiver unit 1002 in the embodiment can be realized by a signal interface. For example, as another possible implementation method, the above-mentioned device 100 can adopt Figure 14 The composition structure shown.

[0296] Figure 11 The structure diagram of a device 110 is shown. The device 110 can be a second CSCF device, a chip in the second CSCF device, a system on chip, or other devices capable of implementing the functions of the second CSCF device in the above method. The device 110 can be used to perform the functions of the second CSCF device involved in the above method embodiment. As an implementation method, Figure 11 The device 110 shown includes: a receiving unit 1101, a processing unit 1102;

[0297] The receiving unit 110 is configured to receive a second communication message from the first CSCF device, where the second communication message includes first call signaling, and the initiator or recipient of the first call signaling is a roaming user equipment of the first CSCF device. For example, the receiving unit 1001 is configured to support the apparatus 110 in executing S402(c), S805, and S905.

[0298] Processing unit 1102 is configured to route the first call signaling to a roaming AS of the incoming user equipment based on the second communication message, where the roaming AS is an AS in the home area of ​​the first CSCF device that is capable of providing a value-added call service to the user equipment. For example, processing unit 1102 is configured to support apparatus 110 in executing S402(c), S805, and S905.

[0299] Specifically, the above Figure 4-Figure 9 All relevant contents of each step involved in the method embodiment can be referred to the functional description of the corresponding functional module, and will not be repeated here. Figure 4-Figure 9 The method shown in the figure implements the function of the second CSCF device in the calling method shown in the figure, and thus can achieve the same effect as the above-mentioned calling method.

[0300] In this embodiment, the device 110 can also be presented in the form of various functional modules divided in an integrated manner. The "functional module" here can refer to an application specific integrated circuit (ASIC), a circuit, a processor and memory that executes one or more software or firmware programs, an integrated logic circuit, and / or other devices that can provide the above functions. In a simple embodiment, those skilled in the art can imagine that the functions / implementation processes of the processing unit 1101 in the device 110 can be implemented by the processor calling computer-executable instructions stored in the memory. Figure 11 The function / implementation process of the transceiver unit 1102 in the embodiment can be realized by a signal interface. For example, as another possible implementation method, the above-mentioned device 110 can adopt Figure 14 The composition structure shown.

[0301] Figure 12 The structure of a device 120 is shown. The device 120 may be a roaming AS, a chip in the roaming AS, a system on chip, or other devices capable of implementing the functions of the roaming AS in the above method. The device 120 may be used to perform the functions of the roaming AS involved in the above method embodiment. As an implementation method, Figure 12 The device 120 shown includes: a receiving unit 1201, a processing unit 1202;

[0302] Receiving unit 1201 is configured to receive a second communication message from a first call session control function (CSCF) device or a second CSCF device; the second communication message includes first call signaling, and the initiator or recipient of the first call signaling is a roaming user equipment of the first CSCF device or the second CSCF device. For example, receiving unit 1201 may support apparatus 120 in executing S403 and S806.

[0303] The processing unit 1202 provides a call value-added service for the roaming user equipment based on the second communication message. For example, the processing unit 1202 can support the apparatus 120 to execute S403 and S806.

[0304] Specifically, the above Figure 4-Figure 9 All relevant contents of each step involved in the embodiment of the method shown can be referred to the functional description of the corresponding functional module, and will not be repeated here. Figure 4-Figure 9 The method shown in the calling method uses the function of the roaming AS in the calling method shown in the embodiment, so it can achieve the same effect as the above calling method.

[0305] In this embodiment, the device 120 can also be presented in the form of various functional modules divided in an integrated manner. The "functional module" here can refer to an application specific integrated circuit (ASIC), a circuit, a processor and memory that executes one or more software or firmware programs, an integrated logic circuit, and / or other devices that can provide the above functions. In a simple embodiment, those skilled in the art can imagine that the functions / implementation processes of the processing unit 1201 in the device 120 can be implemented by the processor calling computer-executable instructions stored in the memory. Figure 12 The function / implementation process of the transceiver unit 1202 in the embodiment can be realized by a signal interface. For example, as another possible implementation method, the above-mentioned device 120 can adopt Figure 14 The composition structure shown.

[0306] Figure 13 The structure diagram of a device 130 is shown. The device 130 can be a home AS, a chip in the home AS, a system on chip, or other devices capable of implementing the functions of the home AS in the above method. The device 130 can be used to perform the functions of the home AS involved in the above method embodiment. As an implementation method, Figure 13 The device 130 shown includes: a receiving unit 1301, a processing unit 1302;

[0307] The receiving unit 1301 is used to receive a seventh communication message from a third call session control function CSCF device; the seventh communication message includes a first call signaling, and the initiator or recipient of the first call signaling is a home user equipment of the third CSCF device; for example, the receiving unit 1301 is used to support the device 130 to execute S506, S810, and S910.

[0308] The processing unit 1302 is configured to route the first call signaling or the second call signaling of the call service corresponding to the first call signaling to a first AS based on the seventh communication message, where the first AS is an AS in a roaming area of ​​the home user equipment. For example, the processing unit 1302 is configured to support the apparatus 130 in executing S506, S810, and S910.

[0309] Specifically, the above Figure 4-Figure 9 All relevant contents of each step involved in the method embodiment can be referred to the functional description of the corresponding functional module, and will not be repeated here. Figure 4-Figure 9 The method shown in the calling method uses the function of the home AS, so it can achieve the same effect as the above calling method.

[0310] In this embodiment, the device 130 can also be presented in the form of various functional modules divided in an integrated manner. The "functional module" here can refer to an application specific integrated circuit (ASIC), a circuit, a processor and memory that executes one or more software or firmware programs, an integrated logic circuit, and / or other devices that can provide the above functions. In a simple embodiment, those skilled in the art can imagine that the functions / implementation processes of the processing unit 1301 in the device 130 can be implemented by the processor calling computer-executable instructions stored in the memory. Figure 13 The function / implementation process of the transceiver unit 1302 in the embodiment can be realized by a signal interface. For example, as another possible implementation method, the above-mentioned device 130 can adopt Figure 14 The composition structure shown.

[0311] As another possible implementation method, the first CSCF device, the second CSCF device, the roaming AS and the home AS can adopt Figure 14 The structure shown, or including Figure 14 Parts shown. Figure 14This is a schematic diagram of the composition of a device 140 provided in an embodiment of the present application. The device 140 may be a first CSCF device, a second CSCF device, a roaming AS, and a home AS, or a chip, a system on a chip in the first CSCF device, the second CSCF device, the roaming AS, and the home AS, or other devices capable of implementing the functions of the first CSCF device, the second CSCF device, the roaming AS, and the home AS in the above method. Figure 14 As shown, the apparatus 140 may include a processor 1401, a communication circuit 1402, and a communication interface 1403. Furthermore, the apparatus 140 may also include a memory 1404. The processor 1401, the memory 1404, and the communication interface 1403 may be connected via the communication circuit 1402. The processor 1401 may integrate the functions of the aforementioned processing units 1002, 1102, 1202, and 1302. The communication interface 1403 may integrate the functions of the aforementioned receiving units 1001, 1101, 1201, and 1301.

[0312] Processor 1401 may be a central processing unit (CPU), a general-purpose processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. Processor 1401 may also be other devices with processing capabilities, such as circuits, devices, or software modules, without limitation.

[0313] The communication line 1402 is used to transmit information between the various components included in the device 140.

[0314] Communication interface 1403 is used to communicate with other devices or other communication networks (such as Ethernet, radio access network (RAN), wireless local area network (WLAN)), etc. Communication interface 1403 can be a module, circuit, transceiver, network interface, or any device capable of implementing communication.

[0315] The memory 1404 is used to store instructions, where the instructions may be computer programs.

[0316] Among them, the memory 1404 can be a read-only memory (ROM) or other types of static storage devices that can store static information and / or instructions, or a random access memory (RAM) or other types of dynamic storage devices that can store information and / or instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc), magnetic disk storage media, or other magnetic storage devices, without limitation.

[0317] It should be noted that the memory 1404 can exist independently of the processor 1401 or can be integrated with the processor 1401. The memory 1404 can be used to store instructions, program codes, or some data. The memory 1404 can be located inside the device 140 or outside the device 140 without limitation.

[0318] The processor 1401 is configured to execute instructions stored in the memory 1404 to implement the calling method provided in the following embodiments of the present application. In one example, the processor 1401 may include one or more CPUs. As an optional implementation, the apparatus 140 includes multiple processors.

[0319] As an optional implementation, the apparatus 140 further includes an output device 1405 and an input device 1406. For example, the input device 1406 is a keyboard, a mouse, a microphone, a joystick, or the like, and the output device 1405 is a display screen, a speaker, or the like.

[0320] It should be noted that the device 140 can be a desktop computer, a portable computer, a network server, a mobile phone, a tablet computer, a wireless terminal, an embedded device, a chip system or a computer with Figure 14 In addition, Figure 14 The structure shown in the figure does not constitute a limitation on the communication device, except Figure 14 In addition to the components shown, the communication device may include more or fewer components than shown, or combine certain components, or arrange the components differently.

[0321] In the embodiment of the present application, the chip system can be composed of chips, or can include chips and other discrete devices.

[0322] The embodiments of the present application also provide a computer-readable storage medium. All or part of the processes in the above-mentioned method embodiments can be completed by a computer program to instruct the relevant hardware, and the program can be stored in the above-mentioned computer-readable storage medium. When the program is executed, it can include the processes of the above-mentioned method embodiments. The computer-readable storage medium can be a terminal device of any of the above-mentioned embodiments, such as: an internal storage unit including a data sending end and / or a data receiving end, such as a hard disk or memory of the terminal device. The above-mentioned computer-readable storage medium can also be an external storage device of the above-mentioned terminal device, such as a plug-in hard disk, a smart memory card (smart media card, SMC), a secure digital (secure digital, SD) card, a flash card (flash card), etc. equipped on the above-mentioned terminal device. Furthermore, the above-mentioned computer-readable storage medium can also include both the internal storage unit of the above-mentioned terminal device and an external storage device. The above-mentioned computer-readable storage medium is used to store the above-mentioned computer program and other programs and data required by the above-mentioned terminal device. The above-mentioned computer-readable storage medium can also be used to temporarily store data that has been output or is to be output.

[0323] The present application also provides a computer instruction. All or part of the process in the above method embodiment can be completed by the computer instruction to instruct the relevant hardware (such as a computer, processor, network device, and terminal, etc.). The program can be stored in the above computer-readable storage medium.

[0324] It should be understood that in the embodiments of the present application, "B corresponding to A" means that B is associated with A. For example, B can be determined based on A. It should also be understood that determining B based on A does not mean determining B based solely on A; B can also be determined based on A and / or other information. In addition, the "connection" in the embodiments of the present application refers to various connection methods, such as direct connection and indirect connection, to achieve communication between devices, and the embodiments of the present application do not impose any limitations on this.

[0325] In the description of this application, unless otherwise specified, " / " indicates that the objects associated with each other are in an "or" relationship. For example, A / B can represent A or B. "And / or" in the embodiments of this application is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. In addition, in the description of this application, unless otherwise specified, "multiple" means two or more than two. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple. In addition, in order to facilitate the clear description of the technical solutions of the embodiments of this application, in the embodiments of this application, words such as "first" and "second" are used to distinguish between identical or similar items with basically the same functions and effects. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit differences. At the same time, in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or design. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way for easy understanding.

[0326] Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0327] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0328] The units described as separate components may or may not be physically separate, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0329] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0330] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a device, such as a single-chip microcomputer, a chip, etc., or a processor to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

[0331] The above is only a specific embodiment of the present application, but the scope of protection of this application is not limited to this. Any changes or substitutions within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A calling method, applied to a first call session control function (CSCF) device, characterized in that: The method comprises: receiving a first communication message, where the first communication message includes first call signaling, and an initiator or a receiver of the first call signaling is a roaming user equipment of the first CSCF device; Routing the first call signaling to a roaming application server (AS) of the roaming user equipment based on the first communication message, the roaming AS being an AS in the home area of ​​the first CSCF device that has the capability of providing a call value-added service for the user equipment; The step of routing the first call signaling to the roaming application server AS of the roaming user equipment based on the first communication message includes: Determining, based on the first communication message, that an initiator or a recipient of the first call signaling is a roaming user equipment of the first CSCF device; Routing the first call signaling to the roaming AS; The routing of the first call signaling to the roaming AS includes: A second communication message is sent to a second CSCF device in the home area of ​​the first CSCF device or the roaming AS, where the second communication message includes the first call signaling and first indication information, where the first indication information indicates that the initiator or recipient of the first call signaling is a roaming user device of the first CSCF device.

2. The method according to claim 1, characterized in that The first indication information further instructs that the first call signaling or the second call signaling of a call service corresponding to the first call signaling be routed to the roaming area AS of the roaming user equipment.

3. The method according to claim 1 or 2, characterized in that The method further comprises: The first indication information and the call service or communication session corresponding to the first call signaling are stored in correspondence.

4. The method according to claim 1 or 2, characterized in that The second communication message also includes address information of the second CSCF device, so that the second communication message is routed to the second CSCF device.

5. The method according to claim 1 or 2, characterized in that The determining, based on the first communication message, that the initiator or recipient of the first call signaling is a roaming user equipment of the first CSCF device includes: Determining, based on a From header field or an Asserted-Identity header field in the first communication message, that the initiator of the first call signaling is a roaming user equipment of the first CSCF device; or Based on the arrival-to header field in the first communication message, it is determined that the recipient of the first call signaling is a roaming user equipment of the first CSCF device.

6. The method according to claim 1 or 2, characterized in that The method further comprises: receiving a third communication message sent by the roaming AS, where the third communication message includes the first call signaling, the first indication information, and second indication information, where the second indication information is used to indicate that the roaming AS will provide a value-added call service for the roaming user equipment; or, the second indication information is used to indicate that the roaming AS has already provided the value-added call service for the roaming user equipment; A fourth communication message is sent to a third CSCF device in the home zone of the roaming user equipment, where the fourth communication message includes the first call signaling, the first indication information, and the second indication information.

7. The method according to claim 6, characterized in that The method further comprises: receiving a fifth communication message from the third CSCF device, the fifth communication message including the first indication information and third indication information, the three indication information being used to indicate that the home AS of the roaming user equipment will provide a call value-added service for the roaming user equipment; According to the first indication information, a sixth communication message is sent to the roaming AS, where the sixth communication message includes the first indication information and the third indication information.

8. The method according to claim 6, characterized in that The method further comprises: receiving a fifth communication message from the third CSCF device, where the fifth communication message includes the first indication information and the second indication information; According to the first indication information, a sixth communication message is sent to the roaming AS, where the sixth communication message includes the first indication information and the second indication information.

9. The method according to any one of claims 1, 2, 7 and 8, characterized in that Before routing the first call signaling to the roaming AS based on the first communication message, the method further includes: It is determined that the roaming user equipment has the capability of using a value-added call service provided by an AS in a home area of ​​the first CSCF device.

10. The method according to any one of claims 1, 2, 7 and 8, characterized in that: The second CSCF device in the home zone of the first CSCF device is an interrogation-call session function I-CSCF device or a serving-call session control function S-CSCF device in the home zone of the first CSCF device.

11. The method according to any one of claims 1, 2, 7 and 8, characterized in that: The first CSCF device is a Proxy-Call Session Control Function P-CSCF device.

12. A calling method, applied to a second call session control function CSCF device, characterized in that: The method comprises: receiving a second communication message from a first call session control function (CSCF) device, where the second communication message includes first call signaling, and an initiator or a recipient of the first call signaling is a roaming user equipment of the first CSCF device; Routing the first call signaling to a roaming application server (AS) of the roaming user equipment based on the second communication message, the roaming AS being an AS in the home area of ​​the first CSCF device that has the capability of providing a call value-added service for the user equipment; The second communication message further includes first indication information, where the first indication information is used to indicate that an initiator or a recipient of the first call signaling is a roaming user equipment of the first CSCF device; and routing the first call signaling to a roaming application server AS of the roaming user equipment based on the second communication message includes: According to the first indication information, the second communication message is sent to the roaming AS.

13. The method according to claim 12, characterized in that The first indication information further instructs that the first call signaling or the second call signaling of a call service corresponding to the first call signaling be routed to the roaming area AS of the roaming user equipment.

14. The method according to claim 12 or 13, characterized in that The method further comprises: The first indication information and the call service or communication session corresponding to the first call signaling are stored in correspondence.

15. The method according to claim 12 or 13, characterized in that The second communication message further includes address information of the second CSCF device, so that the second communication message is routed to the second CSCF device.

16. The method according to claim 12 or 13, characterized in that The method further comprises: receiving a third communication message sent by the roaming AS, where the third communication message includes the first call signaling, the first indication information, and second indication information, where the second indication information is used to indicate that the roaming AS will provide a value-added call service for the roaming user equipment, or the second indication information is used to indicate that the roaming AS has already provided the value-added call service for the roaming user equipment; A fourth communication message is sent to a third CSCF device in the home zone of the roaming user equipment, where the fourth communication message includes the first call signaling, the first indication information, and the second indication information.

17. The method according to claim 16, characterized in that The method further comprises: receiving a fifth communication message from the third CSCF device, the fifth communication message including the first indication information and third indication information, the three indication information being used to indicate that the home AS of the roaming user equipment will provide a call value-added service for the roaming user equipment; According to the first indication information, a sixth communication message is sent to the roaming AS, where the sixth communication message includes the first indication information and the third indication information.

18. The method according to claim 16, characterized in that The method further comprises: receiving a fifth communication message from the third CSCF device, where the fifth communication message includes the first indication information and the second indication information; According to the first indication information, a sixth communication message is sent to the roaming AS, where the sixth communication message includes the first indication information and the second indication information.

19. The method according to any one of claims 12, 13, 17 and 18, characterized in that The second CSCF device is an Query-Call Session Function I-CSCF device in the home area of ​​the first CSCF device or a Serving-Call Session Control Function S-CSCF device in the home area of ​​the second CSCF device.

20. A calling method, applied to a first application server AS, characterized in that: The method comprises: receiving a second communication message from a first call session control function (CSCF) device or a second CSCF device; wherein the second communication message includes first call signaling, and an initiator or a recipient of the first call signaling is a roaming user equipment of the first CSCF device or the second CSCF device; providing a value-added call service for the roaming user equipment based on the second communication message; The second communication message further includes first indication information, where the first indication information is used to indicate that the initiator or receiver of the first call signaling is a roaming user equipment of the first CSCF device.

21. The method according to claim 20, characterized in that The first indication information further instructs that the first call signaling or second call signaling of a call service corresponding to the first call signaling be routed to the first AS.

22. The method according to claim 20 or 21, characterized in that The method further comprises: The first indication information and the call service or communication session corresponding to the first call signaling are stored in correspondence.

23. The method according to claim 20 or 21, characterized in that The providing a value-added call service for the roaming user equipment based on the second communication message includes: providing a value-added call service for the roaming user equipment in response to the second communication message; A third communication message is sent to the second CSCF device, where the third communication message includes the first call signaling, the first indication information, and second indication information, where the second indication information indicates that the first AS has provided a value-added call service for the roaming user equipment.

24. The method according to claim 20 or 21, characterized in that The providing a value-added call service to the roaming user equipment based on the second communication message includes: In response to the second communication message, sending a third communication message to the second CSCF device, where the third communication message includes the first call signaling, the first indication information, and second indication information, where the second indication information indicates that the first AS will provide a value-added call service for the roaming user equipment; receiving a sixth communication message from the second CSCF device, the sixth communication message including the first call signaling, the first indication information, and third indication information, the third indication information indicating that the home AS of the roaming user equipment will provide a call value-added service for the roaming user equipment; In response to the sixth communication message, a call value-added service is provided to the roaming user equipment.

25. A calling method, applied to a second application server AS, characterized in that: The method comprises: receiving a seventh communication message from a third call session control function (CSCF) device; wherein the seventh communication message includes first call signaling, and an initiator or a recipient of the first call signaling is a home user equipment of the third CSCF device; Routing the first call signaling or the second call signaling of the call service corresponding to the first call signaling to a first AS based on the seventh communication message, where the first AS is an AS of a roaming area of ​​the home user equipment; The seventh communication message further includes first indication information, where the first indication information is used to indicate that the initiator or receiver of the first call signaling is a roaming user equipment of a first CSCF device, and the first CSCF device is a CSCF device in a roaming area of ​​the home user equipment.

26. The method according to claim 25, characterized in that The first indication information further instructs that the first call signaling or the second call signaling of a call service corresponding to the first call signaling be routed to the roaming area AS of the home user equipment.

27. The method according to claim 25 or 26, characterized in that The method further comprises: The first indication information and the call service or communication session corresponding to the first call signaling are stored in correspondence.

28. The method according to claim 25 or 26, characterized in that The routing, based on the seventh communication message, the first call signaling or second call signaling of a call service corresponding to the first call signaling to the first AS includes: In response to the seventh communication message, an eighth communication message is sent to the third CSCF device, including the first call signaling, the first indication information and third indication information, where the third indication information indicates that the second AS will provide a call value-added service for the roaming user equipment.

29. The method according to claim 25 or 26, characterized in that The routing, based on the seventh communication message, the first call signaling or second call signaling of a call service corresponding to the first call signaling to the first AS includes: In response to the seventh communication message, an eighth communication message is sent to the third CSCF device, including the first call signaling and the first indication information.

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