CN118018997A

CN118018997A - Calling method, device, first core network equipment and third core network equipment

Info

Publication number: CN118018997A
Application number: CN202211394379.XA
Authority: CN
Inventors: 程思涵
Original assignee: Vivo Mobile Communication Co Ltd
Current assignee: Vivo Mobile Communication Co Ltd
Priority date: 2022-11-08
Filing date: 2022-11-08
Publication date: 2024-05-10
Also published as: WO2024099139A1

Abstract

The application discloses a calling method, a device, first core network equipment and third core network equipment, belonging to the technical field of communication, wherein the calling method of the embodiment of the application comprises the following steps: the method comprises the steps that first core network equipment receives a first call request, wherein the first call request is used for requesting to establish a target service for a first terminal, the first call request comprises a first value, and the first value is a value of a target parameter corresponding to the target service; in case the first value does not match the second value, the first core network device performs any of the following: transmitting a call response to the first terminal, wherein the call response comprises the second value; a second call request is sent to a second terminal, the second terminal is a call receiver corresponding to the first call request, and the second call request comprises the second value; wherein the second value is a value of the target parameter supported by a roaming network serving the first terminal.

Description

Calling method, device, first core network equipment and third core network equipment

Technical Field

The application belongs to the technical field of communication, and particularly relates to a calling method, a calling device, first core network equipment and third core network equipment.

Background

The different operators support different cases for voice, for example, the mobile network operators (mobile network operator, MNO) A, B, C support voice with guaranteed bit rates (Guaranteed Bit Rate, GBR) of 64kbps,156kbps,512kbps, respectively, i.e. the GBR upper limit used by MNO a is equal to 64kbps; the upper limit of GBR used by MNO B is equal to 156kbps; the upper limit of GBR used by MNO C is equal to 512kbps. For example, when a terminal (e.g., user Equipment (UE)) served by an MNO C roams to an MNO a, the terminal initiates an IP multimedia subsystem (IP Multimedia Subsystem, IMS) session request according to the stored MNO C configuration, and establishes a voice bearer with GBR of 512kbps.

In the related art, when the MNO establishes a voice bearer according to the negotiation result of the IMS layer, the MNO only supports the establishment of the voice bearer with the GBR upper limit of 64kbps, which results in that the fourth generation mobile communication technology (4th Generation Mobile Communication Technology,4G)/the fifth generation mobile communication technology (5th Generation Mobile Communication Technology,5G) core network Mobility management entity (Mobility MANAGEMENT ENTITY, MME) or the session management function (Visited Session Management Function, V-SMF) of the roaming network refuses the voice bearer establishment request, thereby resulting in the failure of the voice bearer establishment, and the user cannot use the voice service in the roaming area.

Disclosure of Invention

The embodiment of the application provides a calling method, a calling device, first core network equipment and third core network equipment, which can solve the problem of how to establish voice service for a user in a roaming place.

In a first aspect, a calling method is provided, the method comprising:

The method comprises the steps that first core network equipment receives a first call request, wherein the first call request is used for requesting to establish a target service for a first terminal, the first call request comprises a first value, and the first value is a value of a target parameter corresponding to the target service;

In case the first value does not match the second value, the first core network device performs any of the following:

Transmitting a call response to the first terminal, wherein the call response comprises the second value;

A second call request is sent to a second terminal, the second terminal is a call receiver corresponding to the first call request, and the second call request comprises the second value;

The second value is a value of a target parameter corresponding to the target service supported by a roaming network providing service for the first terminal.

In a second aspect, a calling method is provided, the method comprising:

The third core network device sends a first call request to the first core network device; the first call request is used for establishing a target service for a first terminal, and the first call request comprises a first value which is the value of a target parameter corresponding to the target service; the first call request also comprises second information; the second information includes at least one of:

The indication information is used for indicating that the first terminal is in a roaming state;

A first public land mobile network identifying a PLMN ID, the first PLMN ID being a PLMN ID of a roaming site network;

and the second value is the value of the target parameter corresponding to the target service supported by the roaming network for providing service for the first terminal.

In a third aspect, there is provided a calling device comprising:

The first receiving module is used for receiving a first call request, wherein the first call request is used for requesting to establish a target service for a first terminal, the first call request comprises a first value, and the first value is the value of a target parameter corresponding to the target service;

A first sending module, configured to perform any one of the following in a case where the first value does not match the second value:

In a fourth aspect, there is provided a calling device comprising:

the second sending module is used for sending a first call request to the first core network equipment; the first call request is used for establishing a target service for a first terminal, and the first call request comprises a first value which is the value of a target parameter corresponding to the target service; the first call request also comprises second information; the second information includes at least one of:

In a fifth aspect, there is provided a first core network device comprising a processor and a memory storing a program or instructions executable on the processor, which program or instructions when executed by the processor implement the steps of the calling method as described in the first aspect.

In a sixth aspect, a first core network device is provided, including a processor and a network interface, where: the network interface is used for receiving a first call request, the first call request is used for requesting to establish a target service for a first terminal, the first call request comprises a first value, and the first value is the value of a target parameter corresponding to the target service; in case the first value does not match the second value, either of the following is performed: transmitting a call response to the first terminal, wherein the call response comprises the second value; a second call request is sent to a second terminal, the second terminal is a call receiver corresponding to the first call request, and the second call request comprises the second value; the second value is a value of a target parameter corresponding to the target service supported by a roaming network providing service for the first terminal.

In a seventh aspect, a third core network device is provided, comprising a processor and a memory storing a program or instructions executable on the processor, which program or instructions when executed by the processor implement the steps of the communication processing method according to the second aspect.

An eighth aspect provides a third core network device, including a processor and a network interface, wherein: the network interface is used for sending a first call request to first core network equipment; the first call request is used for establishing a target service for a first terminal, and the first call request comprises a first value which is the value of a target parameter corresponding to the target service; the first call request also comprises second information; the second information includes at least one of: the indication information is used for indicating that the first terminal is in a roaming state; a first public land mobile network identifying a PLMN ID, the first PLMN ID being a PLMN ID of a roaming site network; and the second value is the value of the target parameter corresponding to the target service supported by the roaming network for providing service for the first terminal.

In a ninth aspect, a call system is provided, comprising: the first core network device is operable to perform the steps of the method according to the first aspect, the second terminal, the first core network device and the third core network device is operable to perform the steps of the method according to the second aspect.

In a tenth aspect, there is provided a readable storage medium having stored thereon a program or instructions which when executed by a processor, performs the steps of the method according to the first aspect or performs the steps of the method according to the second aspect.

In an eleventh aspect, there is provided a chip comprising a processor and a communication interface coupled to the processor, the processor being for running a program or instructions to implement the method according to the first aspect or to implement the method according to the second aspect.

In a twelfth aspect, there is provided a computer program/program product stored in a storage medium, the computer program/program product being executed by at least one processor to implement the steps of the method as described in the first aspect or to implement the steps of the method as described in the second aspect.

In the embodiment of the application, after receiving a first call request for establishing a target service for a first terminal, first core network equipment sends a call response carrying a second value to the first terminal under the condition that a first value corresponding to the target service required to be established is not matched with a second value supported by a roaming area network, so that the first terminal modifies parameters corresponding to the target service based on the second value and then initiates the call request again, thereby successfully establishing a voice service for a user in the roaming area; and/or the first core network device sends a second call request carrying the second value to the call receiver so that the call receiver establishes the target service based on the second value, thereby successfully establishing the voice service for the user in the roaming place, and thus, the user experience can be improved.

Drawings

Fig. 1 is a schematic diagram of a wireless communication system to which embodiments of the present application are applicable;

FIG. 2 is a schematic diagram of a prior art method for establishing a voice bearer between UE-1 and UE-2;

fig. 3 is a schematic flow chart of a calling method according to an embodiment of the present application;

FIG. 4 is a second flow chart of a calling method according to the embodiment of the application;

fig. 5 is a schematic diagram of a process of a UE-1 initiating a registration request according to an embodiment of the present application;

FIG. 6 is a schematic diagram of a process for establishing a voice bearer between UE-1 and UE-2 according to an embodiment of the present application;

fig. 7 is a second schematic diagram of a process of initiating a registration request by UE-1 according to an embodiment of the present application;

FIG. 8 is a second schematic diagram of a procedure for establishing a voice bearer between UE-1 and UE-2 according to an embodiment of the present application;

FIG. 9 is a third diagram illustrating a procedure for establishing a voice bearer between UE-1 and UE-2 according to an embodiment of the present application;

Fig. 10 is a schematic structural diagram of a calling device according to an embodiment of the present application;

FIG. 11 is a second schematic diagram of a calling device according to an embodiment of the present application;

Fig. 12 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 13 is a schematic structural diagram of a core network device according to an embodiment of the present application.

Detailed Description

The technical solutions of the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which are derived by a person skilled in the art based on the embodiments of the application, fall within the scope of protection of the application.

The terms first, second and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application are capable of operation in sequences other than those illustrated or otherwise described herein, and that the "first" and "second" distinguishing between objects generally are not limited in number to the extent that the first object may, for example, be one or more. Furthermore, in the description and claims, "and/or" means at least one of the connected objects, and the character "/" generally means a relationship in which the associated object is an "or" before and after. The term "indicated" in the description and claims of the present application may be either an explicit indication or an implicit indication. The explicit indication may be understood as that the sender explicitly informs the receiver of the operation or request result that needs to be performed in the sent indication; the implicit indication is understood as that the receiving side judges according to the indication sent by the sending side, and determines the operation or the request result to be executed according to the judging result.

It should be noted that the techniques described in the embodiments of the present application are not limited to long term evolution (Long Term Evolution, LTE)/LTE evolution (LTE-Advanced, LTE-a) systems, but may also be used in other wireless communication systems, such as code division multiple access (Code Division Multiple Access, CDMA), time division multiple access (Time Division Multiple Access, TDMA), frequency division multiple access (Frequency Division Multiple Access, FDMA), orthogonal frequency division multiple access (Orthogonal Frequency Division Multiple Access, OFDMA), single carrier frequency division multiple access (Single-carrier Frequency Division Multiple Access, SC-FDMA), and other systems. The terms "system" and "network" in embodiments of the application are often used interchangeably, and the techniques described may be used for both the above-mentioned systems and radio technologies, as well as other systems and radio technologies. The following description describes a New Radio (NR) system for exemplary purposes and NR terminology is used in much of the following description, but the techniques may also be applied to communication systems other than NR system applications, such as a 6 th Generation (6G) communication system.

Fig. 1 is a schematic diagram of a wireless communication system to which an embodiment of the present application is applicable, and the wireless communication system shown in fig. 1 includes a terminal 11 and a network-side device 12. The terminal 11 may be a Mobile phone, a tablet Computer (Tablet Personal Computer), a Laptop (Laptop Computer) or a terminal-side device called a notebook, a Personal digital assistant (Personal DIGITAL ASSISTANT, PDA), a palm Computer, a netbook, an ultra-Mobile Personal Computer (ultra-Mobile Personal Computer, UMPC), a Mobile internet appliance (Mobile INTERNET DEVICE, MID), an augmented reality (augmented reality, AR)/Virtual Reality (VR) device, a robot, a wearable device (Wearable Device), a vehicle-mounted device (VUE), a pedestrian terminal (PUE), a smart home (home device with a wireless communication function, such as a refrigerator, a television, a washing machine, a furniture, etc.), a game machine, a Personal Computer (Personal Computer, a PC), a teller machine, or a self-service machine, etc., and the wearable device includes: intelligent wrist-watch, intelligent bracelet, intelligent earphone, intelligent glasses, intelligent ornament (intelligent bracelet, intelligent ring, intelligent necklace, intelligent anklet, intelligent foot chain etc.), intelligent wrist strap, intelligent clothing etc.. In addition to the above terminal device, a Chip in the terminal, such as a Modem (Modem) Chip, a System on Chip (SoC), may be used. It should be noted that the specific type of the terminal 11 is not limited in the embodiment of the present application.

The network-side device 12 may include an access network device or a core network device, where the access network device may also be referred to as a radio access network device, a radio access network (Radio Access Network, RAN), a radio access network function, or a radio access network element. The access network device may include a base station, a WLAN access Point, a WiFi node, or the like, where the base station may be referred to as a node B, an evolved node B (eNB), an access Point, a base transceiver station (Base Transceiver Station, BTS), a radio base station, a radio transceiver, a Basic service set (Basic SERVICE SET, BSS), an Extended service set (Extended SERVICE SET, ESS), a home node B, a home evolved node B, a transmission and reception Point (TRANSMITTING RECEIVING Point, TRP), or some other suitable term in the art, and the base station is not limited to a specific technical vocabulary so long as the same technical effect is achieved, and it should be noted that, in the embodiment of the present application, only the base station in the NR system is described by way of example, and the specific type of the base station is not limited. The core network device may include, but is not limited to, at least one of: core network nodes, core network functions, mobility management entities (Mobility MANAGEMENT ENTITY, MME), access Mobility management functions (ACCESS AND Mobility Management Function, AMF), session management functions (Session Management Function, SMF), user plane functions (User Plane Function, UPF), policy control functions (Policy Control Function, PCF), policy and charging Rules Function units (Policy AND CHARGING Rules functions, PCRF), edge application service discovery functions (Edge Application Server Discovery Function, EASDF), unified data management (Unified DATA MANAGEMENT, UDM), unified data warehousing (Unified Data Repository, UDR), home subscriber servers (Home Subscriber Server, HSS), centralized network configuration (Centralized network configuration, CNC), network storage functions (Network Repository Function, NRF), network opening functions (Network Exposure Function, NEF), local NEF (or L-NEF), binding support functions (Binding Support Function, BSF), application functions (Application Function, AF), location management functions (location manage Function, LMF), enhanced services mobile location center (ENHANCED SERVING Mobile Location Centre, E-SMLC), network data analysis functions (work DATA ANALYTICS functions, NWDAF), and the like. It should be noted that, in the embodiment of the present application, only the core network device in the NR system is described as an example, and the specific type of the core network device is not limited.

In order to facilitate a clearer understanding of the technical solutions provided by the embodiments of the present application, some relevant background knowledge is first described below.

Referring to fig. 2, fig. 2 is a schematic diagram of a prior art UE-1 and UE-2 establishing a voice bearer. In FIG. 2, a flow of establishing a voice bearer between UE-1 and UE-2 is illustrated, and the voice call is performed by UE-1 and UE-2 in a roaming-to-roaming-location public land mobile network (Visit Public Land Mobile Network, VPLMN) scenario, specifically as follows:

Step 1: UE-1 establishes a protocol data unit (Protocol Data Unit, PDU) session in the roaming network using the AMF, V-SMF of the roaming network.

Step 2: the UE-1 initiates an IMS setup request, initiates the request through a session initiation protocol (Session Initiation Protocol, SIP) invite message, carries the information of the voice media to be setup in the requested session description information (Session Description Protocol, SDP), and requests to setup a voice bearer with GBR of 512kbps through b=as: 512.

Step 3: the Proxy call session control function (Proxy-Call Session Control Function, P-CSCF) sends the invite message to UE-2 via the Serving-call session control function (Serving-Call Session Control Function, S-CSCF).

It should be noted that: in the figure, both the P-CSCF and the S-CSCF are IMS network elements for providing services for the UE-1, and the IMS network elements for providing services for the UE-2 are not embodied.

Step 4: UE-2 replies to the SIP 183 message through the S-CSCF, which contains SDP ANSWER in the message.

Step 5: the P-CSCF sends a hypertext transfer protocol (Hyper Text Transfer Protocol, HTTP) notification (POST) Request (Request) to a policy control function (Policy Control Function, PCF) serving the UE-1, carrying media description information (media info) negotiated by SDP, which is derived from an SDP answer (answer) message, containing information that requires the use of 512 kbps.

Note that: the PCF is a 5G network element, and the corresponding 4G network element is PCRF.

Step 6: the PCF sends a request (i.e., modifies SM policy association (SM policy association modification)) to the home SMF of UE-1, i.e., H-SMF, requesting to establish a voice bearer, and the request carries the quality of service (Quality of Service, qoS) parameters of the voice bearer to be established, including information that GBR is 512 kbps.

Step 7: the H-SMF sends a request to the V-SMF;

I.e., nsmf _pdu session Update Request (Nsmf _ PDUSession _update Request), the QoS parameters are included in the Request.

Step 8: according to the requested QoS parameter and the QoS parameter which can be supported by the V-SMF, judging that the roaming area network cannot support the GBR bearing of 512kbps, and then the V-SMF sends a rejection message to the H-SMF; i.e., nsmf _pdu session Reject (Nsmf _ PDUSession _reject).

Step 9: the H-SMF sends a rejection message to the PCF; i.e. initiate SM policy association rejection (SM policy association reject).

Step 10: the PCF sends a reject message to the P-CSCF.

Step 11: the P-CSCF sends a bye message to UE-1 for terminating the call.

Step 12: the P-CSCF sends a bye message to UE-2 for terminating the call.

In the flow shown in fig. 2, when the UE-1 is in the roaming network, the voice bearer establishment fails due to the inconsistent parameters of the voice bearers supported by the home network and the roaming network, so that the user cannot use the voice service in the roaming network.

The call method, the call device, the first core network device and the third core network device provided by the embodiment of the application are described in detail below through some embodiments and application scenarios thereof with reference to the accompanying drawings.

Fig. 3 is a schematic flow chart of a calling method according to an embodiment of the present application, as shown in fig. 3, the method includes steps 301 to 302; wherein:

Step 301, a first core network device receives a first call request, where the first call request is used to request to establish a target service for a first terminal, and the first call request includes a first value, where the first value is a value of a target parameter corresponding to the target service.

Firstly, it should be noted that the embodiment of the present application can be applied to a scenario where two communication parties make a call; the core network devices include, but are not limited to, the types of network side devices 12 listed above, as the application is not limited in this regard.

In the related art, when a terminal is in a roaming network, the parameters supported by a home network and a roaming network are inconsistent, which results in that the terminal cannot dial or answer the voice. In order for both parties to successfully establish voice communications, therefore, in this embodiment, the first core network device needs to receive a first call request for requesting to establish a target service for the first terminal; wherein the first terminal may be a terminal in a roaming network.

It should be noted that, in one possible implementation manner of this embodiment, the first core network device includes an S-CSCF; the first core network device receives a first call request from the first terminal or the second terminal.

In another possible implementation of this embodiment, the first core network device includes an application server (Application Server, AS); the first core network device receives a first call request from the first terminal or the second terminal.

In yet another possible implementation manner of this embodiment, the first core network device includes an AS; the first core network device receives a first call request from a third core network device, wherein the third core network device comprises an S-CSCF.

The first call request includes a first value, where the first value is a value of a target parameter corresponding to the target service.

Optionally, the target service includes at least one of:

a) A voice call service;

b) Video call service.

Optionally, the target parameter includes at least one of:

a)GBR；

b) Maximum Bit Rate (MBR).

Optionally, the first value is a GBR value of a voice call service carried by the first terminal in the call request, for example, the first value is 512kbps.

Step 302, in the case that the first value does not match the second value, the first core network device performs any one of the following:

a second call request is sent to a second terminal, the second terminal is a call receiver corresponding to the first call request, and the second call request comprises the second value; wherein the second value is a value of the target parameter supported by a roaming network serving the first terminal.

Because the second value is the value of the target parameter of the target service supported by the roaming network that provides the service for the first terminal, the mismatch between the first value and the second value means that the value of the target parameter corresponding to the target service is not matched, that is, the roaming network cannot successfully establish the target service for the first terminal.

Alternatively, the second value is a GBR value of a voice call service supported by a roaming network serving the first terminal, for example, the second value is 64kbps.

Optionally, the value of the target parameter of the target service supported by the roaming network may also be understood as the maximum value or the minimum value that the roaming network can provide for the target parameter corresponding to the target service.

In this embodiment, in case the first value does not match the second value, the first core network device sends a call response comprising the second value to the first terminal, wherein the call response message, e.g. 488 message, is used to indicate rejection of the first call request. Specifically, 488 message refers to no acceptable here.

Specifically, in the case where the first core network device includes an S-CSCF, the first core network device transmits a call response including the second value to the first terminal after judging that the first value does not match the second value.

Or the first core network device sends a second call request comprising a second value to the second terminal.

Specifically, in the case where the first core network device includes an AS, the first core network device needs to modify the first value to the second value after judging that the first value does not match the second value, and then sends a second call request including the second value to the second terminal.

Optionally, the first value does not match the second value, including at least one of:

a) The first value is greater than the second value;

b) The absolute value of the difference between the first value and the second value is greater than a first threshold.

Optionally, the sending a call response to the first terminal includes: the first core network device sends 488 a message to the first terminal, the 488 message carrying the second value.

Optionally, before the first core network device receives the first call request, it needs to determine whether the first terminal is in a roaming state, and specifically includes the following steps:

Step 1, the first core network device receives a registration request from a second core network device, wherein the registration request is initiated by the first terminal, and the registration request includes a first public land mobile network identifier (PLMN ID), and the first PLMN ID is a PLMN ID of the roaming network.

Optionally, the terminal initiates an IMS registration request, which is routed to a second core network device, which sends to the first core network device.

Step 2, the first core network device determines first information based on the first PLMN ID; the first information includes at least one of:

a) The indication information is used for indicating that the first terminal is in a roaming state;

b) The first PLMN ID;

c) The second value.

It should be noted that, the first core network device may determine whether the first terminal is in the roaming state by any one of the following manners:

In mode 1, when the first core network device includes an S-CSCF and the second core network device includes a P-CSCF, the P-CSCF writes a first PLMN ID into a received registration request and sends the registration request to the S-CSCF, and then the S-CSCF determines first information based on the first PLMN ID in the registration request, so as to determine whether the first terminal is in a roaming state. Since the first PLMN ID of the roaming network is included in the registration request, the S-CSCF may obtain the first PLMN ID in a registration (registration) process, determine first information based on the first PLMN ID, and determine whether the first terminal is in a roaming state based on indication information in the first information.

Optionally, the S-CSCF determines that the first terminal is in the roaming state according to the difference between the ID of the PLMN to which the S-CSCF belongs and the first PLMN ID included in the registration request message.

In mode 2, when the first core network device includes an AS and the second core network device includes an S-CSCF, after the S-CSCF receives a registration request initiated by the first terminal, the S-CSCF sends the registration request to the AS, and then the AS determines first information based on a first PLMN ID in the registration request, so AS to determine whether the first terminal is in a roaming state.

Since the registration request includes the first PLMN ID of the roaming network, the AS may obtain the first PLMN ID in the registration process, determine the first information based on the first PLMN ID, and determine whether the first terminal is in the roaming state based on the indication information in the first information.

Optionally, the AS determines that the first terminal is in the roaming state according to the difference between the ID of the PLMN to which the AS belongs and the first PLMN ID included in the registration request message.

In the above embodiment, during the registration process, the first core network device can determine whether the first terminal is in the roaming state based on the first information. Under the condition that the first terminal is judged to be in a roaming state, the first core network equipment judges whether a first value corresponding to a target service which is requested to be established is matched with a second value supported by a roaming place network or not; under the condition that the first value is not matched with the second value, the roaming area network can not successfully establish the target service for the first terminal; further, the first core network device sends a call response carrying a second value to the first terminal, so that the first terminal modifies the parameters corresponding to the target service based on the second value and then initiates a call request again; and/or the first core network device sends a second call request carrying a second value to the call receiver so that the call receiver establishes a target service based on the second value, thereby successfully establishing a voice service for the user in a roaming place.

Optionally, the first core network device determines the first information based on the first PLMN ID, which may specifically be implemented by at least one of the following ways:

mode 1, the first core network device determines the second value based on a first mapping relationship and the first PLMN ID; the first mapping relationship is used for indicating the value of the target parameter which is respectively signed by the home network of the first terminal and different roaming networks.

Specifically, in the first mapping relationship, a Home public land mobile network (Home PLMN, HPLMN) of the first terminal has different subscriptions with different VPLMNs, that is, different VPLMNs correspond to different GBR values or MBR values.

For example, the first mapping relationship includes:

the GBR of the voice call service signed by the HPLMN of the first terminal and the PLMN-1 has the value of 128kbps;

The GBR of the voice call service signed by the HPLMN of the first terminal and the PLMN-2 has the value of 64kbps;

the GBR of the voice call service signed by the HPLMN of the first terminal and the PLMN-3 is 32kbps;

at this time, it is required that a first core network device (e.g., S-CSCF or AS) records to which VPLMN the first terminal specifically roams, and obtains the GBR or MBR value of the HPLMN subscribed to the VPLMN based on the VPLMN ID.

Mode 2, the first core network device determines the second value based on a second mapping relationship and the first PLMN ID; the second mapping relationship is used for indicating the value of the target parameter uniformly contracted by the home network and at least one roaming network of the first terminal.

Specifically, in the second mapping relationship, the HPLMN of the first terminal has a unified subscription with all VPLMNs, that is, the same GBR value or MBR value is used as long as the first terminal is in any roaming network. At this time, the first core network device (e.g., S-CSCF or AS) only needs to record that the first terminal is in the roaming state.

Mode 3, the first core network device determines the second value based on configuration information and the first PLMN ID; the configuration information includes the second value corresponding to the first PLMN ID.

In mode 4, the first core network device determines that the first terminal is in a roaming state based on the first PLMN ID and a second PLMN ID, where the second PLMN ID is a PLMN ID of a home network of the first terminal.

In the above embodiment, the first core network device may determine, based on the first PLMN ID, indication information for indicating that the first terminal is in a roaming state, the first PLMN ID, and the second value; based on the second value, the first terminal in the roaming network can successfully establish the target service with the second terminal, and user experience is improved.

Optionally, the first core network device determines whether the first value and the second value match, which may be specifically implemented by the following steps: and under the condition that the first core network equipment receives the first call request, the first core network equipment obtains the second value according to the first information and judges whether the first value is matched with the second value.

Specifically, in one possible implementation manner of this embodiment, the first core network device includes an S-CSCF; the S-CSCF stores the first information, obtains a second value according to the stored first information after the S-CSCF receives the first call request from the first terminal or the second terminal, compares the second value with the first value in the first call request, and judges whether the first value is matched with the second value.

In another possible implementation manner of this embodiment, the first core network device includes an AS; the AS stores the first information, obtains a second value according to the stored first information after the AS receives the first call request from the first terminal or the second terminal, compares the second value with the first value in the first call request, and judges whether the first value is matched with the second value.

In the above embodiment, the first core network device stores the first information, then obtains the second value based on the first information, and compares the second value with the first value in the first call request, so as to determine whether the first value and the second value match; under the condition that the first value is not matched with the second value, the first core network equipment sends a call response carrying the second value to the first terminal, so that the first terminal modifies the parameters corresponding to the target service based on the second value and then initiates a call request again, and further the voice service is successfully established for the user in the roaming place; and/or the first core network device sends a second call request carrying the second value to the call receiver so that the call receiver establishes the target service based on the second value, thereby successfully establishing the voice service for the user in the roaming place, and thus, the user experience can be improved.

Optionally, the first core network device includes an AS; in the case that the third core network device includes an S-CSCF, the first core network device receives a first call request, specifically through the following steps:

the first core network equipment receives the first call request from the third core network equipment; the first call request also comprises second information; the second information includes at least one of:

b) The first PLMN ID;

c) The second value.

Specifically, when the S-CSCF receives a first call request from the first terminal or the second terminal, the S-CSCF sends the first call request to the AS, where the first call request further includes second information.

The AS obtains a second value (for example, the value of the GBR parameter) supported by the voice service of the roaming network according to the second information, and when the AS judges that the second value is not matched with the GBR parameter contained in the first call request, the AS modifies the value of the GBR parameter in the first call request into the second value, and then sends a second call request to the second terminal, wherein the second call request comprises the second value.

Optionally, the second information is determined specifically by: the first core network device determines the second information based on the first call request.

In the above embodiment, when the first value and the second value are not matched, the first core network device modifies the value of the first value in the first call request to the second value, and then sends the second call request to the second terminal, so that the first terminal and the second terminal in the roaming network can successfully establish the target service based on the second value, and user experience is improved.

Fig. 4 is a second flowchart of a calling method according to an embodiment of the application, as shown in fig. 4, the method includes a step 401; wherein:

Step 401, a third core network device sends a first call request to a first core network device; the first call request is used for establishing a target service for a first terminal, and the first call request comprises a first value which is the value of a target parameter corresponding to the target service; the first call request also comprises second information; the second information includes at least one of:

A first PLMN ID, the first PLMN ID being a PLMN ID of a roaming site network;

For convenience of description, the voice communication service at the time of the target service is described below as an example.

In the case that the terminal is in the roaming network, the parameters supported by the home network and the roaming network are inconsistent, which results in that the terminal cannot dial or answer the voice.

In order for both parties to establish a voice communication successfully, the third core network device sends a first call request comprising a first value to the first core network device in this embodiment.

Optionally, the first core network device includes an AS; the third core network device comprises an S-CSCF.

Specifically, the S-CSCF sends a first call request to the AS, where the first call request includes a first value and second information.

Accordingly, after receiving the first call request from the S-CSCF, the AS first determines whether the first terminal is in a roaming state based on the indication information. And under the condition that the first terminal is in a roaming state and the first value is not matched with the second value, the AS modifies the value of the first value in the first call request to the second value, and then sends a second call request to the second terminal, wherein the second call request comprises the second value.

Optionally, the target parameter includes at least one of: GBR; MBR.

Optionally, the target service includes at least one of: a voice call service; video call service.

In the above embodiment, the third core network device sends, to the first core network device, a first call request for establishing a target service for the first terminal, where the first call request includes a first value and second information, and the second information includes a second value; accordingly, after receiving a first call request for establishing a target service for a first terminal, the first core network device sends a second call request carrying a second value to a call receiver under the condition that a first value corresponding to the target service required to be established is not matched with the second value supported by a roaming network, so that the call receiver establishes the target service based on the second value, thereby successfully establishing a voice service for a user in the roaming area, and improving user experience.

Optionally, before the third core network device sends the first call request to the first core network device, it needs to determine whether the first terminal is in a roaming state, and specifically includes the following steps:

Step 1, the third core network device receives a registration request from a fourth core network device, wherein the registration request is initiated by the first terminal, and the registration request comprises the first PLMN ID;

step 2, the third core network device determines first information based on the first PLMN ID; the first information includes at least one of:

b) The first PLMN ID;

c) The second value.

Optionally, the fourth core network device comprises a P-CSCF.

For example, the S-CSCF receives a registration request from the P-CSCF, the registration request including the first PLMN ID; the S-CSCF then determines the first information based on the first PLMN ID.

Optionally, the third core network device determines the first information based on the first PLMN ID, specifically by any one of the following manners:

In mode 1, the third core network device determines the second value based on a first mapping relationship and the first PLMN ID; the first mapping relationship is used for indicating the value of the target parameter which is respectively signed by the home network of the first terminal and different roaming networks.

Mode 2, the third core network device determines the second value based on a second mapping relationship and the first PLMN ID; the second mapping relationship is used for indicating the value of the target parameter uniformly contracted by the home network and at least one roaming network of the first terminal.

Mode 3, the third core network device determines the second value based on configuration information and the first PLMN ID; the configuration information comprises the second value corresponding to the first PLMN ID;

In the mode 4, the third core network device determines that the first terminal is in a roaming state based on the first PLMN ID and a second PLMN ID, where the second PLMN ID is a PLMN ID of a home network of the first terminal.

Optionally, the third core network device determines whether the first value and the second value match, specifically by the following steps:

Step 1, the third core network equipment stores first information;

And 2, under the condition that the third core network equipment receives the first call request, the third core network equipment obtains the second value according to the stored first information, and judges whether the first value is matched with the second value.

For example, the S-CSCF stores the first information after determining the first information based on the first PLMN ID; and under the condition that the S-CSCF receives the first call request, obtaining a second value according to the stored first information, and judging whether the first value is matched with the second value.

Referring to fig. 5, fig. 5 is a schematic diagram of a process of initiating a registration request by UE-1 according to an embodiment of the present application, and specific steps are as follows:

Step 1, the UE-1 sends an IMS registration (Register) request message.

Step 2, the P-CSCF subscribes to the modification of the PLMN serving the UE-1 with the Home policy control function (Home PCF, H-PCF) of the UE-1.

Step 3, the H-PCF sends a notification message to the P-CSCF, the notification message carrying the ID of the PLMN (VPLMN) currently serving the UE-1.

And 4, the P-CSCF sends a registration request message to the S-CSCF, wherein the registration request message carries the VPLMN ID.

And 5, the S-CSCF records the first information.

Specifically, the first information includes at least one of: the indication information is used for indicating that the UE-1 is in a roaming state; VPLMN ID; the VPLMN corresponds to the value of the first value (e.g. GBR parameter) that can be used by the voice service.

Wherein, the GBR parameter value is obtained and stored by the S-CSCF according to the VPLMN ID.

And 6, finishing the registration process.

Referring to fig. 6, fig. 6 is a schematic diagram of a process of establishing a voice bearer between UE-1 and UE-2 according to an embodiment of the present application, and specifically includes the following steps:

step 1, the S-CSCF receives an invite request sent by the UE-1 or the UE-2, and the invite request carries a first value (for example, GBR parameter) corresponding to the voice service requested by the UE-1 or the UE-2.

For example, a voice bearer with GBR of 512kbps is requested to be established by b=as: 512.

Step 2, the S-CSCF obtains a second value (e.g. GBR parameters usable by voice services of the PLMN serving the UE-1) according to the recorded first information.

The manner in which the S-CSCF records the first information is shown in fig. 5.

And step 3, if the GBR information value is not matched with the GBR value carried in the invite message by the UE-1, the S-CSCF sends 488 message to the UE-1, wherein the 488 contains GBR parameters which can be used by the VPLMN.

It should be noted that the mismatch may be understood as that the first value is greater than the second value, or that the absolute value of the difference between the first value and the second value is greater than a preset value, or that the first value is greater than the second value and the absolute value of the difference between the first value and the second value is greater than the preset value.

After the S-CSCF sends 488 the message to UE-1, UE-1 uses the second reinitiation invite message contained in 488.

It will be appreciated that UE-2 may also be the calling party, as described herein with respect to UE-1 calling party. I.e., UE-2 initiates a call to UE-1 in fig. 6, at which point the S-CSCF sends 488 a message to UE-2 after receiving the invite request from UE-2.

In one possible implementation of this embodiment, the HPLMN of UE-1 has different subscriptions to different VPLMNs, i.e. the GBR has different values. At this time, the S-CSCF needs to record which VPLMN the UE-1 specifically roams to, and obtain the GBR value of the HPLMN subscribed to the VPLMN based on the VPLMN ID.

In another possible implementation of this embodiment, the HPLMN of UE-1 has a unified subscription with all VPLMNs, i.e. the GBR value is used whenever UE-1 is in the VPLMN network. At this time, the S-CSCF only needs to record that the UE is in a roaming state.

The S-CSCF may obtain the GBR value usable by the VPLMN locally, or may obtain the GBR value from another network element.

Referring to fig. 7, fig. 7 is a second schematic diagram of a process of initiating a registration request by UE-1 according to an embodiment of the present application, and specifically includes the following steps:

Step 1, the UE-1 sends an IMS registration (Register) request message.

Step 2, the P-CSCF subscribes to the H-PCF for UE-1 for modification of the PLMN serving UE-1.

Step 5, S-CSCS sends a registration request message to AS, wherein the message carries the VPLMN ID.

And 6, the AS records the first information.

The first information of the base may be information that the UE-1 is in a roaming state, or VPLMN ID, or a GBR parameter value that can be used by a voice service corresponding to VPLMN.

The GBR parameter is obtained and stored by the AS according to the VPLMN ID.

And 7, finishing the registration process.

Referring to fig. 8, fig. 8 is a second schematic diagram of a process for establishing a voice bearer between UE-1 and UE-2 according to an embodiment of the present application, and specifically includes the following steps:

Step 2, the S-CSCF sends the invite request to the AS that serves the UE-1.

Step 3, the AS obtains a second value (i.e. GBR parameter usable by the voice service of the VPLMN providing the service for the UE-1) according to the recorded first information, where the manner in which the AS records the first information is shown in fig. 7.

Step 4, if the GBR value is not matched with the GBR value carried in the invite message by the UE-1, the AS modifies the GBR parameter of the invite message into a parameter usable by the VPLMN and sends the parameter to the S-CSCF; for example, modified to b=as: 64.

It should be noted that the mismatch may be understood as that the first value is smaller than the second value, or that the absolute value of the difference between the first value and the second value is larger than the preset value, or that the first value is smaller than the second value and the absolute value of the difference between the first value and the second value is larger than the preset value.

And step 5, the S-CSCF sends the modified invite request to the UE-2.

Step 6-9, the UE-2 carries the description information of the voice received by the opposite terminal through a response message, for example, 200 OK.

It should be noted that, here, taking the UE-1 calling AS an example, UE-2 may also be a calling subscriber, that is, in fig. 8, UE-2 initiates a call to UE-1, and AS may also perform parameter modification when it receives an invite sent by UE-2.

Referring to fig. 9, fig. 9 is a third schematic diagram of a process of establishing a voice bearer between UE-1 and UE-2 according to an embodiment of the present application, and the specific steps are as follows:

it should be noted that, in this embodiment, the procedure of initiating the registration request by the UE-1 is the same as that of fig. 7, and will not be described here again.

Step 2, the S-CSCF sends the invite request to an AS providing services for the UE-1, where the invite request carries second information, where the second information may be information that the UE-1 is in a roaming state, or a VPLMN ID, or a GBR parameter value that can be used by a voice service corresponding to the VPLMN.

Step 3, the AS obtains a second value (namely GBR parameters usable by the voice service of the VPLMN for providing service for the UE-1) according to the second information.

Step 4, if the GBR parameter value is not matched with the GBR parameter value carried in the invite message by the UE-1, the AS modifies the GBR parameter of the invite message into a parameter usable by the VPLMN and sends the parameter to the S-CSCF; for example, to b=as: 64

A mismatch is understood to mean that the first value is greater than the second value, or that the absolute value of the difference between the first value and the second value is greater than a preset value, or that the first value is greater than the second value and the absolute value of the difference between the first value and the second value is greater than a preset value.

And step 5-9, the S-CSCF sends the modified invite request to the UE-2. The UE-2 carries the description information of the received voice of the opposite terminal through a response message, for example, 200 OK.

It should be noted that, here, taking the UE-1 calling AS an example, UE-2 may also be a calling subscriber, that is, in fig. 9, UE-2 initiates a call to UE-1, and AS may also perform parameter modification when it receives an invite sent by UE-2.

According to the calling method provided by the embodiment of the application, the execution main body can be a calling device. In the embodiment of the present application, a calling device executes a calling method as an example, and the calling device provided in the embodiment of the present application is described.

Fig. 10 is a schematic structural diagram of a calling device according to an embodiment of the present application, and as shown in fig. 10, the calling device 1000 is applied to a first core network device, and includes:

A first receiving module 1001, configured to receive a first call request, where the first call request is used to request that a target service be established for a first terminal, and the first call request includes a first value, where the first value is a value of a target parameter corresponding to the target service;

a first sending module 1002, configured to perform any one of the following in a case where the first value does not match the second value:

In the calling device provided by the embodiment of the application, after receiving the first call request for establishing the target service for the first terminal, the first core network equipment sends a call response carrying the second value to the first terminal under the condition that the first value corresponding to the target service required to be established is not matched with the second value supported by the roaming area network, so that the first terminal modifies the parameter corresponding to the target service based on the second value and then initiates the call request again, thereby successfully establishing the voice service for the user in the roaming area; and/or the first core network device sends a second call request carrying the second value to the call receiver so that the call receiver establishes the target service based on the second value, thereby successfully establishing the voice service for the user in the roaming place, and thus, the user experience can be improved.

The first value is greater than the second value;

the absolute value of the difference between the first value and the second value is greater than a first threshold.

Optionally, the apparatus further comprises:

A second receiving module, configured to receive a registration request from a second core network device, where the registration request is initiated by the first terminal, and the registration request includes a first PLMN ID identified by a public land mobile network, where the first PLMN ID is a PLMN ID of the roaming network;

a first determining module, configured to determine first information based on the first PLMN ID; the first information includes at least one of:

The first PLMN ID;

The second value.

Optionally, the first determining module is further configured to at least one of:

Determining the second value based on a first mapping relationship and the first PLMN ID; the first mapping relation is used for indicating the value of the target parameter respectively contracted by the home network of the first terminal and different roaming networks;

determining the second value based on a second mapping relationship and the first PLMN ID; the second mapping relation is used for indicating the value of the target parameter uniformly contracted by the home network and at least one roaming network of the first terminal;

determining the second value based on configuration information and the first PLMN ID; the configuration information comprises the second value corresponding to the first PLMN ID;

and determining that the first terminal is in a roaming state based on the first PLMN ID and a second PLMN ID, wherein the second PLMN ID is the PLMN ID of a home network of the first terminal.

Optionally, the apparatus further comprises:

And the first judging module is used for obtaining the second value according to the first information under the condition that the first core network equipment receives the first call request, and judging whether the first value is matched with the second value.

Optionally, the first core network device includes a serving call session control function, and the second core network device includes a proxy call session control function;

or the first core network device comprises an application server and the second core network device comprises a serving call session control function.

Optionally, the first receiving module 1001 is further configured to:

receiving the first call request from a third core network device; the first call request also comprises second information; the second information includes at least one of:

The first PLMN ID;

The second value.

Optionally, the apparatus further comprises:

And the second determining module is used for determining the second information by the first core network device based on the first call request.

Optionally, the first core network device includes an application server; the third core network device includes a serving call session control function.

Optionally, the first sending module 1002 is further configured to:

And sending 488 message to the first terminal, wherein the 488 message carries the second value.

Optionally, the target parameter includes at least one of: guaranteeing bit rate GBR; maximum bit rate MBR.

Fig. 11 is a second schematic structural diagram of a calling device according to an embodiment of the present application, as shown in fig. 11, the calling device 1100 is applied to a third core network device, and includes:

A second sending module 1101, configured to send a first call request to a first core network device; the first call request is used for establishing a target service for a first terminal, and the first call request comprises a first value which is the value of a target parameter corresponding to the target service; the first call request also comprises second information; the second information includes at least one of:

In the calling device provided by the embodiment of the application, a first calling request for establishing a target service for a first terminal is sent to first core network equipment, wherein the first calling request comprises a first value and second information, and the second information comprises a second value; accordingly, after receiving a first call request for establishing a target service for a first terminal, the first core network device sends a second call request carrying a second value to a call receiver under the condition that a first value corresponding to the target service required to be established is not matched with the second value supported by a roaming network, so that the call receiver establishes the target service based on the second value, thereby successfully establishing a voice service for a user in the roaming area, and improving user experience.

Optionally, the apparatus further comprises:

A third receiving module, configured to receive a registration request from a fourth core network device, where the registration request is initiated by the first terminal, and the registration request includes the first PLMN ID;

a third determining module, configured to determine first information based on the first PLMN ID; the first information includes at least one of:

The first PLMN ID;

The second value.

Optionally, the third determining module is further configured to at least one of:

Optionally, the apparatus further comprises:

and the second judging module is used for obtaining the second value according to the first information under the condition that the third core network equipment receives the first call request, and judging whether the first value is matched with the second value.

Optionally, the fourth core network device comprises a proxy call session control function.

The calling device in the embodiment of the application can be an electronic device, such as an electronic device with an operating system, or can be a component in the electronic device, such as an integrated circuit or a chip. The electronic device may be a terminal, or may be other devices than a terminal. By way of example, the terminals may include, but are not limited to, the types of terminals 11 listed above, other devices may be servers, network attached storage (Network Attached Storage, NAS), etc., and embodiments of the present application are not limited in detail.

The calling device provided by the embodiment of the application can realize each process realized by the method embodiments of fig. 3 to 9 and achieve the same technical effects, and in order to avoid repetition, the description is omitted here.

Fig. 12 is a schematic structural diagram of a communication device according to an embodiment of the present application, as shown in fig. 12, the communication device 1200 includes a processor 1201 and a memory 1202, where the memory 1202 stores a program or an instruction that can be executed on the processor 1201, for example, when the communication device 1200 is a first core network device, the program or the instruction implements the steps of the foregoing call method embodiment shown in fig. 3 when executed by the processor 1201, and the same technical effects can be achieved. When the communication device 1200 is a third core network device, the program or the instructions, when executed by the processor 1201, implement the steps of the foregoing embodiment of the call method as shown in fig. 4, and achieve the same technical effects, so that repetition is avoided, and no further description is given here.

Optionally, fig. 13 is a schematic structural diagram of a core network device according to an embodiment of the present application. As shown in fig. 13, the core network apparatus 1300 includes: processor 1301, network interface 1302, and memory 1303. The network interface 1302 is, for example, a common public radio interface (common public radio interface, CPRI).

Specifically, the core network device 1300 according to the embodiment of the present invention further includes: instructions or programs stored in the memory 1303 and executable on the processor 1301, for example, when the core network device 1300 is a first core network device, the processor 1301 invokes the instructions or programs in the memory 1303 to implement the steps of the foregoing embodiment of the call method shown in fig. 3, and the same technical effects can be achieved. When the core network device 1300 is the third core network device, the processor 1001 invokes the instructions or the program in the memory 1003 to implement the steps of the foregoing embodiment of the call method shown in fig. 4, and the same technical effects can be achieved, so that repetition is avoided and no further description is given here.

The embodiment of the application also provides a calling system, which comprises: the first terminal, the second terminal, the first core network device and the third core network device, wherein the first core network device is used for executing the steps of the calling method as described in fig. 3, and the third core network device is used for executing the steps of the calling method as described in fig. 4.

The embodiment of the application also provides a readable storage medium, which can be volatile or nonvolatile, and the readable storage medium stores a program or an instruction, and when the program or the instruction is executed by a processor, the program or the instruction realizes each process of the calling method embodiment, and the same technical effect can be achieved, so that repetition is avoided, and repeated description is omitted.

Wherein the processor is a processor in the terminal described in the above embodiment. The readable storage medium includes computer readable storage medium such as computer readable memory ROM, random access memory RAM, magnetic or optical disk, etc.

The embodiment of the application further provides a chip, which comprises a processor and a communication interface, wherein the communication interface is coupled with the processor, and the processor is used for running programs or instructions to realize the processes of the calling method embodiment, and can achieve the same technical effects, so that repetition is avoided, and the description is omitted.

It should be understood that the chips referred to in the embodiments of the present application may also be referred to as system-on-chip chips, or the like.

The embodiments of the present application further provide a computer program/program product stored in a storage medium, where the computer program/program product is executed by at least one processor to implement each process of the foregoing embodiments of the calling method, and achieve the same technical effects, so that repetition is avoided and details are not repeated herein.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element. Furthermore, it should be noted that the scope of the methods and apparatus in the embodiments of the present application is not limited to performing the functions in the order shown or discussed, but may also include performing the functions in a substantially simultaneous manner or in an opposite order depending on the functions involved, e.g., the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art in the form of a computer software product stored in a storage medium (e.g. ROM/RAM, magnetic disk, optical disk) comprising instructions for causing a terminal (which may be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to perform the method according to the embodiments of the present application.

The embodiments of the present application have been described above with reference to the accompanying drawings, but the present application is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those having ordinary skill in the art without departing from the spirit of the present application and the scope of the claims, which are to be protected by the present application.

Claims

1. A method of calling, comprising:

2. The calling method of claim 1, wherein the first value does not match the second value, comprising at least one of:

The first value is greater than the second value;

3. The calling method according to claim 1 or 2, characterized in that the method further comprises:

The first core network equipment receives a registration request from the second core network equipment, wherein the registration request is initiated by the first terminal, and the registration request comprises a first public land mobile network identification (PLMN ID) which is the PLMN ID of the roaming area network;

The first core network device determines first information based on the first PLMN ID; the first information includes at least one of:

The first PLMN ID;

The second value.

4. A calling method according to claim 3, characterized in that the first core network device determines first information based on the first PLMN ID, comprising at least one of:

The first core network device determines the second value based on a first mapping relation and the first PLMN ID; the first mapping relation is used for indicating the value of the target parameter respectively contracted by the home network of the first terminal and different roaming networks;

The first core network device determines the second value based on a second mapping relation and the first PLMN ID; the second mapping relation is used for indicating the value of the target parameter uniformly contracted by the home network and at least one roaming network of the first terminal;

The first core network device determines the second value based on configuration information and the first PLMN ID; the configuration information comprises the second value corresponding to the first PLMN ID;

the first core network device determines that the first terminal is in a roaming state based on the first PLMN ID and a second PLMN ID, where the second PLMN ID is a PLMN ID of a home network of the first terminal.

5. The calling method according to claim 3 or 4, characterized in that the method further comprises:

And under the condition that the first core network equipment receives the first call request, the first core network equipment obtains the second value according to the first information and judges whether the first value is matched with the second value.

6. A call method as claimed in claim 3, characterized in that the first core network device comprises a serving call session control function and the second core network device comprises a proxy call session control function;

7. The call method according to claim 1 or 2, wherein the first core network device receives a first call request, comprising:

The first PLMN ID;

The second value.

8. The calling method of claim 7, wherein the method further comprises:

the first core network device determines the second information based on the first call request.

9. The calling method of claim 7, wherein the first core network device comprises an application server; the third core network device includes a serving call session control function.

10. The method of claim 1, wherein the sending a call response to the first terminal comprises:

the first core network device sends 488 a message to the first terminal, the 488 message carrying the second value.

11. The calling method according to any of claims 1 to 10, wherein the target parameters comprise at least one of: guaranteeing bit rate GBR; maximum bit rate MBR.

12. The calling method according to any of claims 1 to 10, wherein the target service comprises at least one of: a voice call service; video call service.

13. A method of calling, comprising:

14. The calling method of claim 13, wherein the method further comprises:

The third core network device receives a registration request from a fourth core network device, wherein the registration request is initiated by the first terminal, and the registration request comprises the first PLMN ID;

The third core network device determines first information based on the first PLMN ID; the first information includes at least one of:

The first PLMN ID;

The second value.

15. The calling method of claim 14, wherein the third core network device determines first information based on the first PLMN ID, including at least one of:

The third core network device determines the second value based on a first mapping relation and the first PLMN ID; the first mapping relation is used for indicating the value of the target parameter respectively contracted by the home network of the first terminal and different roaming networks;

The third core network device determines the second value based on a second mapping relationship and the first PLMN ID; the second mapping relation is used for indicating the value of the target parameter uniformly contracted by the home network and at least one roaming network of the first terminal;

The third core network device determines the second value based on configuration information and the first PLMN ID; the configuration information comprises the second value corresponding to the first PLMN ID;

The third core network device determines that the first terminal is in a roaming state based on the first PLMN ID and a second PLMN ID, where the second PLMN ID is a PLMN ID of a home network of the first terminal.

16. The calling method according to claim 14 or 15, characterized in that the method further comprises:

And under the condition that the third core network equipment receives the first call request, the third core network equipment obtains the second value according to the first information and judges whether the first value is matched with the second value.

17. The calling method according to any of claims 13 to 15, characterized in that the first core network device comprises an application server; the third core network device includes a serving call session control function.

18. The calling method of claim 14, wherein the fourth core network device comprises a proxy call session control function.

19. The calling method according to any of claims 13 to 18, wherein the target parameters comprise at least one of: guaranteeing bit rate GBR; maximum bit rate MBR.

20. The calling method according to any of claims 13 to 19, wherein the target service comprises at least one of: a voice call service; video call service.

21. A calling device, comprising:

22. A calling device, comprising:

23. A first core network device comprising a processor and a memory storing a program or instructions executable on the processor, which when executed by the processor, implement the steps of the calling method of any of claims 1 to 12.

24. A third core network device comprising a processor and a memory storing a program or instructions executable on the processor, which when executed by the processor, implement the steps of the calling method of any of claims 13 to 20.

25. A readable storage medium, characterized in that the readable storage medium has stored thereon a program or instructions which, when executed by a processor, implement the calling method of any of claims 1 to 12 or the steps of the calling method of any of claims 13 to 20.