Communication method and communication apparatus

Abstract

The application provides a communication method and a communication device, and relates to the technical field of communication. The method comprises the following steps: sending first information, wherein the first information is used for indicating the first media capability of the first terminal device; sending second information, wherein the second information is used for inviting a second terminal device to join an Internet Protocol Multimedia Subsystem (IMS) session; and receiving third information, wherein the third information is used for indicating the media capability supported by the first terminal device and the second terminal device. The method in the application embodiment can help to reduce the number of signaling interactions, thereby helping to reduce the transmission delay.

Description

Technical Field

[0001] This application relates to the field of communication technology, specifically to a communication method and a communication device. Background Technology

[0002] The Internet Protocol (IP) Multimedia Subsystem (IMS) is a multimedia service technology based on IP networks that can provide users with real-time or non-real-time end-to-end multimedia services, such as voice calls, video calls, multimedia messaging, unified communications, and other diverse services.

[0003] However, the existing IMS process has some problems. For example, the existing IMS process is relatively cumbersome, resulting in high service transmission latency, especially when terminal devices are communicating wirelessly based on non-terrestrial networks (NTN) systems, which can lead to excessively high service transmission latency. Summary of the Invention

[0004] This application provides a communication method and a communication device that helps reduce the number of signaling interactions, thereby helping to reduce transmission latency.

[0005] In a first aspect, a communication method is provided, the method being applied to a first terminal device or a component in the first terminal device (e.g., a processor, chip, chip system, circuit, or a functional module, etc.), the method comprising:

[0006] Send a first message, which indicates a first media capability of the first terminal device; send a second message, which invites the second terminal device to join an Internet Protocol Multimedia Subsystem (IMS) session; receive a third message, which indicates a media capability jointly supported by the first terminal device and the second terminal device.

[0007] In this embodiment, the first terminal device sends first information to indicate the first media capability, which helps the network side determine the media capability jointly supported by the first terminal device and the second terminal device based on the first media capability. In this way, it is not necessary to determine the media capability jointly supported by the first terminal device and the second terminal device through multiple signaling interactions, which helps to reduce the number of signaling interactions and thus helps to reduce transmission latency.

[0008] In some possible implementations, before sending the second information, the method further includes sending a fourth information, the fourth information being used to update the first media capability.

[0009] In this embodiment of the application, the fourth information is used to update the first media capability. The first terminal device sends the fourth information, which helps the network side to dynamically update the media capability of the first terminal device, thereby helping the network side to determine the media capability jointly supported by the first terminal device and the second terminal device.

[0010] In some possible implementations, the fourth information is used to indicate a second media capability of the first terminal device, the second media capability being a dynamic media capability supported by the first terminal device, the second media capability including one or more of the following: media type, encoding method, or bandwidth.

[0011] In some possible implementations, the first information is carried in the first registration request message.

[0012] In this embodiment of the application, the first information is carried in the first registration request message, which helps the network side to know the first media capability of the first terminal device during the registration stage, thereby helping the network side to determine the media capabilities jointly supported by the first terminal device and the second terminal device.

[0013] In some possible implementations, the third information is also used to respond to the second information.

[0014] In this embodiment of the application, the third information is also used to respond to the second information, which helps to reduce the number of signaling interactions and thus helps to reduce transmission latency.

[0015] In some possible implementations, the method further includes: receiving fifth information, the fifth information being used for one or more of the following: responding to a sixth message, instructing the second terminal device to complete resource reservation, or instructing the second terminal device to start ringing; wherein the sixth information is used to instruct the first terminal device to complete resource reservation.

[0016] In the embodiments of this application, the fifth information is used for one or more of the above-mentioned purposes, which helps to reduce the number of signaling interactions, thereby helping to reduce transmission latency.

[0017] In some possible implementations, the fifth information is carried in the first session initiation protocol (SIP) signaling.

[0018] In some possible implementations, the first media capability is a static media capability supported by the first terminal device, and the first media capability includes one or more of the following: media type, encoding method, or bandwidth.

[0019] Secondly, a communication method is provided, the method being applied to a second terminal device or a component (e.g., a processor, chip, chip system, circuit, or a functional module, etc.) in the second terminal device, the method comprising:

[0020] Send a seventh message, which indicates the third media capability of the second terminal device; receive an eighth message, which indicates the media capability jointly supported by the first terminal device and the second terminal device.

[0021] In this embodiment, the second terminal device sends seventh information to indicate the third media capability, which helps the network side determine the media capability jointly supported by the first and second terminal devices based on the third media capability. In this way, it is not necessary to determine the media capability jointly supported by the first and second terminal devices through multiple signaling interactions, which helps to reduce the number of signaling interactions and thus helps to reduce transmission latency.

[0022] In some possible implementations, before receiving the eighth information, the method further includes sending a ninth information, the ninth information being used to indicate updating the third media capability.

[0023] In this embodiment of the application, the ninth information is used to update the third media capability. The second terminal device sends the ninth information, which helps the network side to dynamically update the media capability of the second terminal device, thereby helping the network side to determine the media capability jointly supported by the first terminal device and the second terminal device.

[0024] In some possible implementations, the ninth information is used to indicate the fourth media capability of the second terminal device, which is a dynamic media capability supported by the second terminal device, and the fourth media capability includes one or more of the following: media type, encoding method, or bandwidth.

[0025] In some possible implementations, the seventh information is carried in the second registration request message.

[0026] In this embodiment, the seventh information is carried in the second registration request message, which helps the network side to learn about the third media capabilities of the second terminal device during the registration phase, thereby helping the network side to determine the media capabilities jointly supported by the first terminal device and the second terminal device.

[0027] In some possible implementations, the eighth information is also used to instruct the first terminal device to invite the second terminal device to join an Internet Protocol Multimedia Subsystem (IMS) session.

[0028] In this embodiment of the application, the eighth information is also used to instruct the first terminal device to invite the second terminal device to join the IMS session, which helps to reduce the number of signaling interactions and thus helps to reduce transmission latency.

[0029] In some possible implementations, the method further includes: sending a fifth message, the fifth message being used for one or more of the following: responding to a sixth message, instructing the second terminal device to complete resource reservation, or instructing the second terminal device to start ringing; wherein the sixth message is used to instruct the first terminal device to complete resource reservation.

[0030] In the embodiments of this application, the fifth information is used for one or more of the above-mentioned purposes, which helps to reduce the number of signaling interactions, thereby helping to reduce transmission latency.

[0031] In some possible implementations, the fifth information is carried in the first session initiation protocol (SIP) signaling.

[0032] In some possible implementations, the third media capability is a static media capability supported by the second terminal device, and the third media capability includes one or more of the following: media type, encoding method, or bandwidth.

[0033] Thirdly, a communication method is provided, the method being applied to a first network element or a component within the first network element (e.g., a processor, chip, chip system, circuit, or functional module, etc.), the method comprising:

[0034] Receive first information and seventh information, wherein the first information is used to indicate a first media capability of a first terminal device and the seventh information is used to indicate a third media capability of a second terminal device; receive second information, wherein the second information is used to invite the second terminal device to join an Internet Protocol Multimedia Subsystem (IMS) session; send third information and eighth information, wherein the third information is used to indicate media capabilities jointly supported by the first terminal device and the second terminal device and the eighth information is used to indicate media capabilities jointly supported by the first terminal device and the second terminal device.

[0035] In this embodiment, the first network element receives first information indicating a first media capability and seventh information indicating a second media capability. This helps determine the media capabilities commonly supported by the first and second terminal devices based on the first and second media capabilities. It also facilitates the first network element sending third and eighth information upon receiving the second information. This eliminates the need for multiple signaling interactions between the first and second terminal devices to determine the commonly supported media capabilities, thereby reducing the number of signaling interactions and ultimately reducing transmission latency.

[0036] In some possible implementations, before sending the third and eighth information, the method further includes: determining, based on the first and seventh information, the media capabilities commonly supported by the first terminal device and the second terminal device.

[0037] In this embodiment, the media capabilities jointly supported by the first terminal device and the second terminal device are determined based on the first information and the seventh information. This eliminates the need for multiple signaling interactions between the first terminal device and the second terminal device to determine the jointly supported media capabilities, thereby reducing the number of signaling interactions and thus reducing transmission latency.

[0038] In some possible implementations, before receiving the second information, the method further includes receiving fourth information, the fourth information being used to update the first media capability.

[0039] In this embodiment, the fourth information is used to update the first media capability. Receiving the fourth information helps the first network element dynamically update the media capability of the first terminal device, thereby helping the first network element determine the media capability jointly supported by the first terminal device and the second terminal device.

[0040] In some possible implementations, the fourth information is used to indicate a second media capability of the first terminal device, the second media capability being a dynamic media capability supported by the first terminal device, the second media capability including one or more of the following: media type, encoding method, or bandwidth.

[0041] In some possible implementations, before receiving the second information, the method further includes receiving a ninth information, the ninth information being used to update the third media capability.

[0042] In this embodiment of the application, the ninth information is used to update the third media capability. Receiving the ninth information helps the first network element to dynamically update the media capability of the second terminal device, thereby helping the first network element to determine the media capability jointly supported by the first terminal device and the second terminal device.

[0043] In some possible implementations, the ninth information is used to indicate the fourth media capability of the second terminal device, which is a dynamic media capability supported by the second terminal device, and the fourth media capability includes one or more of the following: media type, encoding method, or bandwidth.

[0044] In some possible implementations, the first information is carried in a first registration request message, and / or the seventh information is carried in a second registration request message.

[0045] In this embodiment of the application, the first information is carried in the first registration request message, and / or the seventh information is carried in the second registration request message, which helps the first network element to know the first media capability of the first terminal device and / or the third media capability of the second terminal device during the registration stage, thereby helping the first network element to determine the media capabilities jointly supported by the first terminal device and the second terminal device.

[0046] In some possible implementations, the third information is also used to respond to the second information, and / or the eighth information is also used to instruct the first terminal device to invite the second terminal device to join the IMS session.

[0047] In the embodiments of this application, the third information is also used to respond to the second information, and / or the eighth information is also used to instruct the first terminal device to invite the second terminal device to join the IMS session, which helps to reduce the number of signaling interactions, thereby helping to reduce transmission latency.

[0048] In some possible implementations, the first media capability is a static media capability supported by the first terminal device, and the first media capability includes one or more of the following: media type, encoding method, or bandwidth; and / or, the third media capability is a static media capability supported by the second terminal device, and the third media capability includes one or more of the following: media type, encoding method, or bandwidth.

[0049] Fourthly, a communication method is provided, the method being applied to a first terminal device or a component in the first terminal device (e.g., a processor, chip, chip system, circuit, or a functional module, etc.), the method comprising:

[0050] The fifth message is received, which is used to respond to the sixth message, to instruct the second terminal device to complete resource reservation, and to instruct the second terminal device to start ringing; wherein the sixth message is used to instruct the first terminal device to complete resource reservation.

[0051] In this embodiment of the application, the fifth information is used to respond to the sixth information, to instruct the second terminal device to complete resource reservation, and to instruct the second terminal device to start ringing. Receiving the fifth information can reduce the number of signaling interactions, thereby reducing transmission latency.

[0052] In some possible implementations, the fifth information is carried in the first session initiation protocol (SIP) signaling.

[0053] Fifthly, a communication method is provided, the method being applied to a second terminal device or a component (e.g., a processor, chip, chip system, circuit, or a functional module, etc.) in the second terminal device, the method comprising:

[0054] Send a fifth message, which is used to respond to the sixth message, to instruct the second terminal device to complete resource reservation, and to instruct the second terminal device to start ringing; wherein, the sixth message is used to instruct the first terminal device to complete resource reservation.

[0055] In the embodiments of this application, the fifth information is used to respond to the sixth information, to instruct the second terminal device to complete resource reservation, and to instruct the second terminal device to start ringing. Sending the fifth information can reduce the number of signaling interactions, thereby reducing transmission latency.

[0056] In some possible implementations, the fifth information is carried in the first session initiation protocol (SIP) signaling.

[0057] In a sixth aspect, a communication device is provided, comprising: the communication device can be used in any of the devices (or network elements) described above; the communication device can be the device (or network element), or a device in the device (or network element) (e.g., a chip, or a chip system, or a circuit, or a processor), or a device that can be used in conjunction with the device (or network element), or a logic module or software that can implement all or part of the device (or network element).

[0058] The communication device includes modules that perform the methods / operations / steps / actions described in any aspect or any possible implementation of any aspect. These modules can be hardware circuits, software, or a combination of hardware circuits and software.

[0059] In a seventh aspect, a communication device is provided, comprising: a processor and a memory, the processor being coupled to the memory, the memory being used to store a computer program (also referred to as code or instructions), the computer program being executed by the processor causing the device to perform a method in any of the above aspects or any possible implementations of any of the above aspects.

[0060] In some possible implementations, the device also includes a memory coupled to the processor.

[0061] In some possible implementations, there are one or more processors, and / or one or more memories.

[0062] In some possible implementations, the memory can be integrated with the processor, or the memory can be set up separately from the processor.

[0063] Eighthly, a computer-readable storage medium is provided that stores a computer program (also referred to as code or instructions) that, when run on a computer, causes the computer to perform the methods of any of the above aspects or any possible implementations thereof.

[0064] Ninthly, a computer program product is provided, comprising: a computer program (also referred to as code or instructions) that, when run on a computer, causes the computer to perform the method of any of the above aspects or any possible implementation thereof.

[0065] In a tenth aspect, a chip is provided, comprising: a processor and a memory, the memory for storing a computer program (also referred to as code or instructions), the processor for calling and running the computer program stored in the memory, such that an apparatus or device on which the chip is mounted performs the method of any of the above aspects or any possible implementation thereof. Attached Figure Description

[0066] Figure 1 This is a schematic flowchart illustrating the IMS session establishment process in one embodiment of this application.

[0067] Figure 2 This is a schematic flowchart illustrating the initial media negotiation process in one embodiment of this application.

[0068] Figure 3 This is a schematic flowchart illustrating the resource reservation completion process in one embodiment of this application.

[0069] Figure 4 This is a schematic diagram of a satellite network architecture according to an embodiment of this application.

[0070] Figure 5 This is a schematic diagram of another satellite network architecture in an embodiment of this application.

[0071] Figure 6 This is a schematic diagram of an IMS system architecture in an embodiment of this application.

[0072] Figure 7 This is a schematic diagram of the IMS architecture between the calling UE and the called UE in one embodiment of this application.

[0073] Figure 8 This is a schematic flowchart of a communication method provided in one embodiment of this application.

[0074] Figure 9 This is a schematic flowchart of a communication method provided in another embodiment of this application.

[0075] Figure 10 This is a schematic flowchart of a communication method provided in another embodiment of this application.

[0076] Figure 11 This is a schematic flowchart of a communication method provided in another embodiment of this application.

[0077] Figure 12 This is a schematic structural diagram of a communication device provided in one embodiment of this application.

[0078] Figure 13 This is a schematic structural diagram of a communication device provided in another embodiment of this application.

[0079] Figure 14 This is a schematic structural diagram of a communication device provided in another embodiment of this application.

[0080] Figure 15 This is a schematic structural diagram of a communication device provided in another embodiment of this application.

[0081] Figure 16 This is a schematic structural diagram of a communication device provided in another embodiment of this application.

[0082] Figure 17 This is a schematic structural diagram of an apparatus provided in one embodiment of this application. Detailed Implementation

[0083] To better illustrate the technical solutions of the embodiments of this application, relevant knowledge will be introduced below.

[0084] The following describes the relevant terms and nouns used in this application.

[0085] Non-terrestrial network (NTN): A network that uses transmission equipment on airborne or spacecraft as relay nodes or base stations.

[0086] Internet Protocol (IP) Multimedia Subsystem (IMS): A form of multimedia service based on IP networks, capable of providing users with real-time or non-real-time end-to-end multimedia services. IMS's modular architecture and standardized interfaces enable it to flexibly support various telecommunications services and seamlessly switch between different access technologies (such as WiFi, 4G, and 5G).

[0087] The proxy-call session control function (P-CSCF) is the first entity a user encounters in the IMS system. The P-CSCF's functions include: session initialization protocol (SIP) compression, providing security protections (such as IP security (IPSec)), policy and charging rules function (PCRF) interaction, and emergency session detection.

[0088] Interrogating-call session control function (I-CSCF): During IMS registration, the I-CSCF queries the HSS to assign a serving-call session control function (S-CSCF). During session establishment, the I-CSCF of the calling party (also known as the calling side, calling terminal equipment, or the calling party, etc.) usually does not participate, while the I-CSCF of the called party (also known as the called side, called terminal equipment, or the called party, etc.) queries the HSS to determine the S-CSCF serving the called party.

[0089] S-CSCF: This is the core control node of the IMS system, handling session logic. During session establishment, for the calling party, S-CSCF routes SIP requests to the called party's network; for the called party, S-CSCF forwards SIP requests to the called party's P-CSCF.

[0090] Home subscriber server (HSS): Stores user data and service configurations, providing necessary information for I-CSCF and S-CSCF.

[0091] SIP is a text-based application layer control protocol used to create, modify, and release sessions of one or more participants.

[0092] Session Description Protocol (SDP): Used in conjunction with SIP in IMS for media negotiation. Media negotiation is crucial in determining how the two parties (caller and callee) communicate, and may include determining the media type, media format, network address, port, bandwidth, etc. If SIP signaling is used for media negotiation or media information updates, it can carry SDP information.

[0093] Resource reservation: In this embodiment, resource reservation refers to the pre-allocation and guarantee of network resources for media streams (such as voice streams and video streams) to be transmitted during the IMS session establishment phase, in order to ensure the quality of service (QoS) of the media streams. Especially in real-time communications (such as Voice Over Long-Term Evolution (VoLTE) and video calls), resource reservation can avoid network congestion, latency, and jitter, thereby providing a high-quality user experience. During the session establishment phase, resource reservation can begin after the calling party and the called party determine the media information of the session.

[0094] Media capabilities: In this embodiment, media capabilities may include the media types and encoding formats supported by the user equipment. These media capabilities may change depending on user preferences, hardware peripherals, network conditions, battery level, and other factors.

[0095] The following explains the meaning of the SIP signaling (or SIP messages) involved in this application.

[0096] Registration Request Signalling (REGISTER): Used by the terminal device to initiate a registration request to IMS. During registration, the binding relationship between the UE's IP address and IP multimedia public identity (IMPU) can be stored in the IMS system.

[0097] Session Invitation Signal (INVITE): Used to initiate a session request, inviting users to join the session. This request includes SDP for negotiating the media type.

[0098] 100 Trying: A temporary response message indicating that the request (such as INVITE) has been received and is being processed. It can prevent INVITE from being retransmitted.

[0099] 183 Session Progress (or simply 183) is a temporary response message used by the called party to indicate that the session is being established but has not yet been completed. This signaling may include early negotiation information for the media stream (such as SDP).

[0100] Provisional response ACK (PRACK): Used to acknowledge receipt of a provisional response (1XX). This signaling may carry SDP information for media negotiation.

[0101] Update request signaling (UPDATE): Used to modify session parameters (such as media type and / or codec, i.e., SDP information). When the calling party completes resource reservation, it can send an UPDATE message to the called party to update the "a=curr" attribute in the SDP information. For example, "a=curr: qos local none" can be updated to "a=curr: qos localsendrev".

[0102] 180RINGING: Temporary response message, indicating that the called party is ringing.

[0103] 200 OK: Indicates a successful response to requests such as INVITE and UPDATE, indicating that the request has been successfully processed. This signaling can carry SDP information.

[0104] ACK: Indicates that the session has been established.

[0105] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0106] IMS can provide users with real-time or non-real-time end-to-end multimedia services, such as voice calls, video calls, multimedia messaging, unified communications, and other diverse services. IMS uses SIP as the call control protocol, which separates call control from service control. It can achieve user registration and session establishment through SIP signaling interaction.

[0107] Figure 1 This is a schematic flowchart illustrating the IMS session establishment process in one embodiment of this application. Figure 1 As shown, the entire establishment process can include three stages: media negotiation stage, resource reservation completion stage, and session establishment stage. The IMS session is established through multiple SIP signaling (also known as SIP message) interactions.

[0108] During the media negotiation phase, the calling party sends an INVITE signaling message to initiate a session invitation to the called party, and completes the negotiation of media type and encoding method after four end-to-end signaling interactions. After determining the media type and encoding method, the calling party and the called party begin resource reservation. During the resource reservation completion phase, the calling party sends an UPDATE signaling message to indicate that it has completed resource reservation, and the called party responds with a 200 OK signaling message to indicate that it has received the UPDATE signaling message and has also completed resource reservation. The session establishment phase includes the process from ringing to session connection.

[0109] SIP signaling can be divided into three parts: the start line, header fields, and message body. Functionally, SIP signaling can be categorized into request messages and response messages. The start line primarily conveys the message type. For request messages, the start line can include a SIP method, such as INVITE, ACK, PRACK, REGISTER, etc. For response messages, the start line can include return codes from 100 to 699, with different codes representing different meanings; for example, 1XX indicates a provisional response, and 2XX indicates a successful response. The header field is a crucial component of SIP signaling, used to transmit control information, describe session attributes, and guide SIP signaling processing and routing. The message body mainly carries SDP information, describing the attributes of the multimedia session, including media type, encoding format, port, and bandwidth information. Of these three parts of SIP signaling, the latter two (i.e., the header field and the message body) occupy a larger portion of the content space.

[0110] As can be seen, the above process involves a large number of signaling interactions and is cumbersome, which can lead to high transmission latency. In particular, when narrowband Internet of Things (NB-IoT) devices communicate wirelessly based on the NTN system, the transmission latency of the service will be too high.

[0111] Taking NB-IoT devices transmitting services via geostationary Earth orbit (GEO) satellites as an example, assuming the GEO transmission rate is 1 kilobits per second (kbps), the above... Figure 1 The size of each SIP signaling message in the session establishment process shown can reach hundreds of bytes or even thousands of bytes. The total size of all SIP signaling messages in the entire session establishment process may approach or even exceed 10,000 bytes. Due to the slow transmission rate of the signaling (1kbps), this will result in excessively high transmission latency.

[0112] The following is combined with Figure 2 and Figure 3 This paper provides a detailed analysis of the media negotiation phase and the resource reservation completion phase in the IMS session establishment process.

[0113] Figure 2 This is a schematic flowchart illustrating the initial media negotiation process in one embodiment of this application. Because... Figure 1 The 100Trying step in the second stage of the media negotiation phase does not carry SDP information, therefore it is not within the scope of the initial media negotiation. Figure 2 The initial media negotiation process shown only includes Figure 1 Steps 1, 3, 4, and 5 of the consultation phase with Chinese media, namely... Figure 2The specific steps of S210, S220, S230, and S240 shown are as follows:

[0114] S210, the calling party initiates an INVITE signaling message to the called party, which can carry the first SDP information, including one or more media types and encoding methods supported by the calling party. For example, the SDP information can indicate that the calling party supports video and audio types. Among them, the encoding methods supported by the video type include MPV encoding and H.261 encoding, and the encoding methods supported by the audio type include pulse code modulation μ-law (PCMU) encoding, G.726 encoding, and adaptive multi-rate-wideband (AMR-WB) encoding.

[0115] S220: The called party sends a 183 signaling message (183 Session In Progress signaling) to the calling party to indicate that it has received the session invitation sent by the calling party and to allow the calling party to reserve the necessary network resources. This signaling message may carry the first SDP response, which contains the called party's confirmation of the media type and encoding method sent by the calling party, i.e., whether the called party supports the media type and encoding method mentioned by the calling party in the INVITE signaling message. For example, the SDP response may indicate that the called party does not support video type (only audio type is supported), and the audio type supports encoding methods including G.726 encoding and AMR-WB encoding.

[0116] S230, in response to the 183 signaling sent by the called party, the calling party sends a PRACK signaling back to the called party. This signaling can carry a second SDP information, which includes the media type and encoding scheme negotiated by both parties. That is, the calling party makes a compromise based on the media type and encoding scheme supported by both parties. For example, the SDP information can instruct the calling party to select the audio type and AMR-WB encoding.

[0117] S240, in response to the PRACK signaling sent by the calling party, the called party sends a 200 OK signaling back to the calling party. This signaling carries a second SDP response, which includes the called party's confirmation of the negotiated media type and encoding scheme. For example, the SDP response can instruct the called party to confirm the audio type and AMR-WB encoding.

[0118] Through the above Figure 2 As can be seen from the process shown, the existing process for negotiating media types and encoding methods is relatively cumbersome, involves a large number of signaling interactions, and increases transmission latency.

[0119] Figure 3 This is a schematic flowchart illustrating the resource reservation completion process in one embodiment of this application. Currently, during the IMS session establishment process, the process from resource reservation completion to ringing can be as follows: Figure 3 As shown, the process may include Figure 1 Steps 6, 7, and 8 of the China-Media Consultation Phase, namely Figure 3 The specific steps of S310, S320, and S330 shown are as follows:

[0120] S310, the calling party sends an UPDATE signaling message to the called party to indicate that the calling party's resources have been successfully reserved. This signaling message can carry SDP information to update its own resource reservation status.

[0121] S320, the called party sends a 200 OK signaling message to the calling party to indicate that the called party has received the UPDATE signaling message sent by the calling party, and at the same time to indicate that the called party's resources have been successfully reserved. This signaling message can also carry SDP information.

[0122] S330: The called party sends a 180RINGING signaling message to the calling party to indicate that the called party has initiated a ringing request to the calling party. At the same time, the called party starts ringing. After receiving the signaling message, the calling party immediately generates a ringback tone. This signaling message does not contain SDP information.

[0123] Through the above Figure 3 As can be seen from the process shown, the existing resource reservation completion process is relatively cumbersome, with many interactions, which increases transmission latency. At the same time, the 200 OK (UPDATE) signaling indicates that the called party has completed resource reservation, while 180 RINGING indicates ringing. The called party sending 180 RINGING signaling to the calling party necessarily means that the called party has completed resource reservation. Therefore, this process involves redundant information transmission, which will further increase transmission latency.

[0124] In summary, the existing IMS process still has some problems. For example, the existing IMS process is relatively time-consuming, especially when the terminal device is communicating wirelessly based on the NTN system, which can lead to excessively high service transmission latency.

[0125] To address at least one of the aforementioned technical problems, this application provides a new technical solution. The technical solution in the embodiments of this application will be described below with reference to the accompanying drawings.

[0126] In the description of this application, unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship. For example, A / B can represent A or B. "And / or" in this application merely describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone, where A and B can be singular or plural. Furthermore, in the description of this application, unless otherwise stated, "multiple" refers to two or more. "At least one of the following" or similar expressions refer 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. Additionally, to facilitate a clear description of the technical solutions of the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first," "second," etc., do not limit the quantity or order of execution, and that "first," "second," etc., do not necessarily imply that they are different. It should be understood that in this application, descriptions such as "in the case of," "if," "when," "if," etc., can be used interchangeably.

[0127] The wireless communication system in this application can be various wireless communication systems, such as 5G systems or new radio (NR), long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, satellite and other non-terrestrial communication systems, and communication systems that integrate terrestrial and non-terrestrial communication. The technical solutions provided in this application can also be applied to future communication systems.

[0128] The terminal device in this application embodiment may refer to user equipment (UE), station, access terminal, user unit, user station, mobile station, mobile station (MS), remote station, remote terminal, mobile terminal (MT), user terminal, terminal (or terminal device), wireless communication equipment, user agent or user device, etc., or a device used to provide voice or data connectivity to users, or an Internet of Things device (such as NB-IoT device). For example, terminal devices include handheld devices with wireless connectivity, vehicle-mounted devices, etc., but this application embodiment does not limit this. The terminal device in this application embodiment may be a mobile phone, cellular phone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device with wireless communication function, computing device or other processing device connected to a wireless modem, large screen, vehicle-mounted device (e.g., car, bicycle, electric vehicle, airplane, ship, train, high-speed rail, etc.), wearable device (e.g., smartwatch, smart bracelet, pedometer, smart glasses, etc.), machine type communication (MTC) terminal device, terminal device in 5G network, or terminal device in future evolved public land mobile network (PLMN), etc., and is not limited to this in this application embodiment.The terminal device in the embodiments of this application may also be a tablet computer, a laptop computer, a handheld computer, a mobile internet device (MID), a virtual reality (VR) device, an augmented reality (AR) device, a point of sale (POS) machine, customer-premises equipment (CPE), a light UE, a reduced capability UE (RedCap UE), a wireless terminal in industrial control, a smart home device (e.g., a refrigerator, a television, an air conditioner, an electricity meter, etc.), a smart robot, a robotic arm, workshop equipment, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, or a flying device (e.g., a smart robot, a hot air balloon, a drone, an airplane), etc. Terminal devices can also be vehicle devices, such as vehicle devices, vehicle modules, vehicle chips, on-board units (OBU), or telematics boxes (T-BOX). Terminal devices can also be other devices with terminal functions. For example, a terminal device can also be a device that plays a terminal function in device-to-device (D2D) communication.

[0129] In some implementations, the terminal device can be used to act as a base station. Optionally, the terminal device can act as a scheduling entity to provide sidelink signals between terminal devices in vehicle-to-everything (V2X) or device-to-device (D2D) scenarios. For example, cellular phones and cars can communicate using sidelink signals, or cellular phones and smart home devices can communicate using sidelink signals without relaying communication signals through a base station.

[0130] The network device (or communication device) in this application embodiment can refer to a radio access network (RAN) node (or device) that connects a terminal device to a wireless network, and can also be called a base station (BS). For example, the network device can be a NodeB, an evolved NodeB (eNodeB), a next-generation NodeB (gNB) in a 5G mobile communication system, a transmission reception point (TRP), an access point (AP), a network device (such as a satellite) in an NTN system, a base station in a future mobile communication system or an access point (AP) in a WiFi system, a wireless controller, relay station, access point, vehicle-mounted device, wearable device, or other network devices in future evolved communication systems, etc.

[0131] In some implementations, multiple RAN nodes can collaborate to assist terminal devices in achieving wireless access, with different RAN nodes each implementing some of the functions of a base station. For example, a RAN node (i.e., the network device in this application) can be a central unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU), etc. CUs and DUs can be set up separately or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio frequency equipment or radio frequency units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs). In different systems, CUs (or CU-CPs and CU-UPs), DUs, or RUs may have different names, but those skilled in the art will understand their meaning. For example, in an open radio access network (O-RAN) system, a CU can also be called an open CU (O-CU), a DU can also be called an open DU (O-DU), a CU-CP can also be called an O-CU-CP, a CU-UP can also be called an O-CU-UP, and a RU can also be called an O-RU. Any of the units among the CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules. It should be understood that this application does not limit the specific technology or specific device form used in the network equipment.

[0132] In some implementations, the network device can be fixed or mobile, and this application does not limit this. For example, a helicopter or drone can be configured as a mobile network device, and one or more cells can move according to the location of the mobile network device. In other examples, a helicopter or drone can be configured as a device to communicate with another network device.

[0133] In some implementations, network devices can be deployed on land or in the air, and this application does not limit this. For example, network devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can also be deployed in the air on airplanes, balloons, and satellites.

[0134] In this embodiment, the terminal device or network device may include a hardware layer, an operating system layer running on top of the hardware layer, and an application layer running on top of the operating system layer. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and memory (also called main memory). The operating system can be any one or more computer operating systems that implement business processing through processes. The application layer includes applications such as browsers, address books, word processing software, and instant messaging software. Furthermore, this embodiment does not specifically limit the specific structure of the execution entity of the method provided in this embodiment, as long as it can communicate according to the method provided in this embodiment by running a program that records the code of the method provided in this embodiment.

[0135] Furthermore, various aspects or features of this application can be implemented as methods, apparatus, or articles of manufacture using standard programming and / or engineering techniques. The term "article of manufacture" as used herein encompasses a computer program accessible from any computer-readable device, carrier, or medium. For example, computer-readable media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks, or magnetic tapes), optical discs (e.g., compact discs (CDs), digital versatile discs (DVDs), etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memory (EPROMs), cards, sticks, or key drives, etc.). Additionally, the various storage media described herein may represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing, and / or carrying instructions and / or data.

[0136] With the development of communication technology, NTN systems have been introduced into some communication systems to improve their coverage. Network devices in an NTN system (also referred to as NTN equipment) can be satellites, high altitude platform stations (HAPS), drones, or other non-ground devices / equipment. HAPS are typically located at an altitude of 8–50 km above the ground. An NTN system that uses satellites (such as network devices) for networking can be called a satellite communication system. For ease of description, the following examples use a satellite communication system to illustrate the NTN system.

[0137] In satellite communication systems, satellites can be classified into three types based on their orbital altitude: geostationary Earth orbit (GEO), medium Earth orbit (MEO), and low Earth orbit (LEO).

[0138] GEO satellites orbit at an altitude of 35,786 km. Their main advantages are relative stationary position relative to the ground and the ability to provide a large coverage area. However, GEO satellites also have significant disadvantages: 1) The large distance between GEO satellites and Earth's orbits results in significant free-space propagation loss, straining communication link budgets and requiring larger-diameter antennas to increase transmit / receive gain; 2) High communication transmission latency, with round-trip delays reaching around 500 ms, which cannot meet the demands of real-time services; 3) Relatively limited orbital resources, high launch costs, and inability to provide coverage to the polar regions.

[0139] MEO satellites orbit at altitudes ranging from 1500 km to 35786 km. Their advantage is that global coverage can be achieved with a relatively small number of MEO satellites. However, MEO satellites orbit at much higher altitudes than LEO satellites, resulting in significantly longer transmission delays. Considering both advantages and disadvantages, MEO satellites are primarily used for positioning and navigation.

[0140] LEO satellites orbit at altitudes ranging from 300km to 1500km. Compared to MEO and GEO satellites, LEO satellites have lower orbital altitudes, resulting in advantages such as lower data propagation latency, lower transmission loss, and relatively lower launch costs. Therefore, NTN communication based on LEO satellites has received widespread attention in recent years.

[0141] The network architecture of a satellite communication system (which can be called a satellite network architecture) can include the following network elements: gateway, service link, feeder link, base station, satellite, and inter-satellite links. Base stations are typically located on the ground and can also be called satellite base stations (which can be understood as base stations in a satellite network); gateways are used to connect satellites and public ground networks, and there can be one or more gateways, usually located on the ground; feeder links are the links for communication between gateways and satellites; service links are the links for communication between terminal equipment and satellites; inter-satellite links are the links for communication between satellites; the interfaces between base stations can be Xn interfaces, the interfaces between base stations and the core network can be next-generation (NG) interfaces, and the interfaces between the core network and the data network can be N6 interfaces.

[0142] Satellites in a satellite communication system can operate in different modes, such as transparent transmission mode and regenerative mode. When satellites operate in these different modes, the satellite communication system can also implement different network architectures.

[0143] Figure 4 This is a schematic diagram of a transparent satellite-based NG-RAN architecture. In this network, the satellite operates in transparent mode, enabling relay forwarding. The gateway can perform all or part of the functions of a base station (gNB). In this case, the satellite and gateway can be considered as remote radio units (RRUs) in a radio access network. The gNB and gateway can be located on the ground, and the gNB can be deployed together with the gateway (or close to it), or the gNB can be deployed separately from the gateway (or far apart). Figure 4 The feeder link in the system can be implemented through an air interface (such as the New Radio Interface (NR Uu)). The delay of the feeder link can include two parts: the delay from the satellite to the gateway and the delay from the gateway to the gNB.

[0144] For example, in Figure 4 In this system, new radio interface signals are transmitted on the feeder link between the gateway and the satellite. When the network transmits downlink data to the UE, the satellite can copy the new radio interface signals transmitted on the feeder link to the serving link between the UE and the satellite. When the UE transmits uplink data to the network, the satellite can copy the radio signals transmitted on the serving link between the UE and the satellite to the feeder link. The gateway can support all the functions necessary for forwarding air interface signals. Different transmission satellites can connect to the same gNB.

[0145] Figure 5This is a schematic diagram of another regenerative satellite-based NG-RAN architecture. In this network, the satellites operate in regenerative mode, possess data processing capabilities, and can perform all or part of the functions of a gNB (gbase station). In this case, the satellites can be regarded as gNBs. Figure 5 The power supply link in the system can be implemented through the NG interface. In this case, the interface between the UE and the satellite can be an air interface.

[0146] For example, in Figure 5 In this context, the satellite can act as a base station to regenerate signals received from the ground. The satellite can contain a gNB or DU. New radio interface signals are transmitted on the service link between the UE and the satellite, and satellite radio interface (SRI) signals are transmitted on the feeder link between the gateway and the satellite. When the UE transmits uplink data to the network side, the UE can send new radio interface signals to the satellite. The satellite can transmit the data to the gateway through the satellite radio interface (SRI), and then the gateway forwards it to the core network equipment on the ground.

[0147] It should be noted that the above Figure 4 and Figure 5 The satellites in the system can be GEO satellites, MEO satellites, LEO satellites, etc., or other non-terrestrial equipment such as HAPS and drones.

[0148] Figure 6 This is a schematic diagram of an IMS system architecture according to an embodiment of this application. Figure 6 As can be seen, IMS is a service layer built on top of the core network (CN). Terminal devices need to complete registration and session management through the core network in order to use the services provided by IMS.

[0149] An IMS system can consist of three layers: the access layer, the call control layer, and the service application layer. The call control layer is the core layer of IMS, responsible for core functions such as call control, security management, service triggering, resource control, and network interconnection. Figure 6As shown, the call control layer may include network elements such as P-CSCF, I-CSCF, S-CSCF, application server (AS), and HSS. Among them, the P-CSCF is the entry point for IMS, used to forward requests or responses, provide integrity and confidentiality protection for SIP signaling, perform SIP signaling compression and decompression (reducing air interface transmission latency), and detect urgent sessions; the I-CSCF is used during session establishment to query the peer's HSS and route SIP messages to the correct S-CSCF; the S-CSCF is responsible for user registration, session establishment, modification, termination, authentication, and routing.

[0150] The Interconnection Border Control function (IBFC) can be used to connect to other operators' IMS networks, while the Breakout Gateway Control function (BGCF) can be used for routing from IMS to circuit-switched (CS) / public-switched telephone networks (PSTN).

[0151] IMS and the core network (such as the 5G core network (5GC)) have a complementary and service integration relationship. For example, 5G networks can provide voice calls and video services by integrating IMS, and IMS can leverage the high network performance and low latency of 5GC to achieve better Quality of Service (QoS) guarantees.

[0152] It should be noted that, Figure 6 Only some network elements in the IMS system are shown in the illustration. The IMS system may contain more or fewer network elements, and this application embodiment does not limit this.

[0153] During the IMS session establishment process, the IMS architecture between the calling UE and the called UE can be as follows: Figure 7 As shown. Figure 7 As shown, the S-CSCF network element in the calling IMS system corresponding to the calling UE can be connected to the I-CSCF network element in the called IMS system corresponding to the called UE.

[0154] To address one or more of the aforementioned technical problems, this application proposes a communication method and a communication device that helps reduce the number of signaling interactions, thereby helping to reduce transmission latency.

[0155] The following is combined with Figure 8 The communication methods in the embodiments of this application are illustrated in detail.

[0156] Figure 8 This is a schematic flowchart of a communication method provided in one embodiment of this application. Figure 8 The method 800 shown may include steps S810, S820 and S830, as detailed below:

[0157] S810: The first terminal device sends the first information to the first network element, and the second terminal device sends the seventh information to the first network element.

[0158] The first terminal device can be the calling UE, and the second terminal device can be the called UE. For example, the first terminal device can be... Figures 1 to 3 The calling device shown in the diagram, the second terminal device can be Figures 1 to 3 The called party is shown in the image.

[0159] The first network element can be an IMS network element; for example, the first network element may include... Figure 6 The IMS system shown includes one or more network elements. Optionally, the first network element may further include the IMS network element corresponding to the first terminal device and the IMS network element corresponding to the second terminal device, wherein the IMS network element corresponding to the first terminal device may include... Figure 6 The IMS system shown may include one or more network elements, and the IMS network element corresponding to the second terminal device may also include... Figure 6 One or more network elements in the IMS system shown. For example, as follows: Figure 9 and Figure 11 As shown, the first network element may include the calling IMS network element and the called IMS network element.

[0160] In some embodiments, the first information may be used to indicate a first media capability of the first terminal device. The first media capability may be a static media capability supported by the first terminal device. Here, static capability refers to media capabilities that the first terminal device itself can support, such as media capabilities that the first terminal device supports at the time of manufacture or that it has long supported. Optionally, the first media capability may include one or more of the following: media type, encoding method, bandwidth, or port, etc.

[0161] In some embodiments, the seventh information may be used to indicate a third media capability of the second terminal device. The third media capability may be a static media capability supported by the second terminal device, such as a media capability that the second terminal device supports at the time of manufacture or has been supported long-term. For example, the third media capability may include one or more of the following: media type, encoding method, bandwidth, or port, etc.

[0162] In some embodiments, the first information may be carried in the first registration request message, such as REGISTER signaling. That is, the first terminal device may send the first information to the first network element when performing IMS registration.

[0163] In some embodiments, the seventh information may be carried in the second registration request message, such as REGISTER signaling. That is, the second terminal device may send the seventh information to the first network element when performing IMS registration.

[0164] It should be noted that the order in which the first terminal device sends the first information and the second terminal device sends the seventh information is not limited in the embodiments of this application. For example, the second terminal device may send the seventh information to the first network element at the same time as the first terminal device sends the first information; or, the second terminal device may send the seventh information to the first network element before the first terminal device sends the first information; or, the second terminal device may send the seventh information to the first network element after the first terminal device sends the first information.

[0165] S820, the first terminal device sends the second information to the first network element.

[0166] The second information can be used to invite a second terminal device to join the IMS session. This second information can be carried in the session invitation signaling, such as the INVITE signaling.

[0167] In some embodiments, the second information may also indicate the media type, encoding method, bandwidth, and / or port that the first terminal device expects (or desires, anticipates, etc.).

[0168] In some embodiments, upon receiving the second information, the first network element may also forward the INVITE signaling to the second terminal device so that the second terminal device is aware that the first terminal device has invited the second terminal device to join the IMS session.

[0169] In some embodiments, the first terminal device may dynamically update the media capabilities it supports.

[0170] For example, before step S820 above, method 800 may also include step S812, as follows:

[0171] S812, the first terminal device sends the fourth information to the first network element.

[0172] The fourth piece of information can be used to update the first media capability.

[0173] In this embodiment, the fourth information is used to update the first media capability. The first terminal device sends the fourth information to the first network element, which helps the first network element to dynamically update the media capability of the first terminal device, thereby helping the network side to determine the media capability jointly supported by the first terminal device and the second terminal device.

[0174] In some embodiments, the fourth information may be used to indicate a second media capability of the first terminal device. The second media capability may be a dynamic media capability supported by the first terminal device. Here, dynamic media capability refers to the media capabilities that the terminal device can support when its own state, network conditions, etc., change.

[0175] For example, changes in network conditions (such as switching between WiFi and cellular networks) can lead to changes in bandwidth or network congestion; or changes in device resources (such as low battery power) or device hardware (connection of new peripherals) can cause changes in media type and encoding method; or changes in user preferences (changes in user device settings) can also cause changes in media type and encoding method.

[0176] Optionally, the second media capability may include one or more of the following: media type, encoding method, bandwidth, or port.

[0177] In some embodiments, the second terminal device may dynamically update its supported media capabilities.

[0178] For example, before step S820 above, method 800 may also include step S814, as follows:

[0179] S814, the second terminal device sends the ninth information to the first network element.

[0180] The ninth piece of information is used to update third-media capabilities.

[0181] In this embodiment, the ninth information is used to update the third media capability. The second terminal device sends the ninth information to the first network element, which helps the first network element to dynamically update the media capability of the second terminal device, thereby helping the network side to determine the media capability jointly supported by the first terminal device and the second terminal device.

[0182] In some embodiments, the ninth information may be used to indicate a fourth media capability of the second terminal device. The fourth media capability may be a dynamic media capability supported by the second terminal device. Optionally, the fourth media capability may include one or more of the following: media type, encoding method, bandwidth, or port, etc.

[0183] S830: The first network element sends the third information to the first terminal device, and the first network element sends the eighth information to the second terminal device.

[0184] The third information can be used to indicate the media capabilities jointly supported by the first terminal device and the second terminal device, and the eighth information can be used to indicate the media capabilities jointly supported by the first terminal device and the second terminal device.

[0185] In some embodiments, the third information can also be used to respond to the second information. Optionally, the third information can be carried in 100 Trying signaling.

[0186] In some embodiments, the eighth message can also be used to instruct the first terminal device to invite the second terminal device to join the IMS session. Optionally, the eighth message can be carried in the INVITE signaling.

[0187] In some embodiments, the first network element can determine the media capabilities jointly supported by the first terminal device and the second terminal device based on the first information and the seventh information. For example, before step S830 above, method 800 may further include step S822, as follows:

[0188] S822, the first network element determines the media capabilities jointly supported by the first terminal device and the second terminal device based on the first information and the seventh information.

[0189] For example, the first terminal device supports both video and audio types. The video type supports MPV and H.261 encoding, while the audio type supports PCMU, G.726, and AMR-WB encoding. The second terminal device only supports audio types, which support G.726 and AMR-WB encoding. In this case, the first network element can select either the audio type or AMR-WB encoding, which represents the media capabilities supported by both the first and second terminal devices.

[0190] In this embodiment, the media capabilities jointly supported by the first terminal device and the second terminal device are determined based on the first information and the seventh information. This eliminates the need for multiple signaling interactions between the first terminal device and the second terminal device to determine the jointly supported media capabilities, thereby reducing the number of signaling interactions and thus reducing transmission latency.

[0191] It should be noted that when the first terminal device and / or the second terminal device update the media capabilities of the first network element, the first network element can determine the media capabilities jointly supported by the first terminal device and the second terminal device based on the updated media capabilities of the first terminal device and / or the second terminal device.

[0192] For example, if the first terminal device sends fourth information to the first network element and the second terminal device sends ninth information to the first network element, the first network element can determine the media capabilities jointly supported by the first and second terminal devices based on the fourth and ninth information. That is, the first network element determines the media capabilities jointly supported by the first and second terminal devices based on the second and fourth media capabilities.

[0193] In some embodiments, the second terminal device may also respond to information sent by the first terminal device indicating that it has completed resource reservation, provide feedback to the first terminal device that it has completed resource reservation, and / or indicate to the first terminal device that it has started ringing.

[0194] For example, after step S830 above, method 800 may further include step S832, as follows:

[0195] S832, the second terminal device sends the fifth information to the first terminal device.

[0196] The fifth message can be used for one or more of the following: responding to the sixth message, instructing the second terminal device to complete resource reservation, or instructing the second terminal device to start ringing.

[0197] Before step S832 above, method 800 may also include step S834, as follows:

[0198] S834, the first terminal device sends the sixth information to the second terminal device.

[0199] Optionally, the sixth information can be used to instruct the first terminal device to complete resource reservation. For example, the sixth information can be carried in an update request signaling, such as an UPDATE signaling.

[0200] In the embodiments of this application, the fifth information is used for one or more of the above-mentioned purposes, which helps to reduce the number of signaling interactions, thereby helping to reduce transmission latency.

[0201] In some embodiments, the fifth information may be carried in the first SIP signaling.

[0202] In this embodiment, the first terminal device sends first information to indicate a first media capability, and the second terminal device sends seventh information to indicate a third media capability. This helps the network side determine the media capabilities jointly supported by the first and second terminal devices based on the first media capability. In this way, it is not necessary to determine the jointly supported media capabilities through multiple signaling interactions between the first and second terminal devices, which helps to reduce the number of signaling interactions and thus helps to reduce transmission latency.

[0203] The following is combined with Figure 9The embodiments of method 800 described above will be illustrated in detail. It should be noted that, as an example, in method 900, the second terminal device indicates the fifth information in step S832 to the first terminal device via two signaling messages: responding to the information sent by the first terminal device indicating that it has completed resource reservation via a 200 OK (UPDATE) message, and reporting back to the first terminal device that it has completed resource reservation; and indicating to the first terminal device that it has started ringing via a 180 RINGING message. Of course, the first terminal device can also indicate multiple of the above information to the first terminal device simultaneously via the same signaling message; this is not limited in the embodiments of this application.

[0204] Figure 9 This is a schematic flowchart of a communication method provided in one embodiment of this application. Figure 9 The method 900 shown may include steps S910 to S990.

[0205] S910, the calling UE sends a REGISTER signaling message to the calling IMS network element, and the called UE sends a REGISTER signaling message to the called IMS network element.

[0206] Both the calling UE and the called UE can report their supported static media capabilities when registering with their respective IMS network elements.

[0207] S920: The calling UE updates dynamic media capabilities to the calling IMS network element, and the called UE updates dynamic media capabilities to the called IMS network element.

[0208] The calling UE can dynamically update its currently supported media types or encoding methods based on its current status (such as its own status, network conditions, etc.); similarly, the called UE can also dynamically update its currently supported media types or encoding methods.

[0209] For example, changes in network conditions (such as switching between WiFi and cellular networks) can lead to changes in bandwidth or network congestion; or changes in device resources (such as low battery power) or device hardware (connection of new peripherals) can cause changes in media type and encoding method; or changes in user preferences (changes in user device settings) can also cause changes in media type and encoding method.

[0210] S930, the calling UE sends an INVITE signaling message to the calling IMS network element.

[0211] The INVITE signaling message can include the media type and encoding method expected by the calling UE. As an example, the INVITE signaling message can indicate that the media type expected by the calling UE is video and the encoding method expected by the calling UE is H.261 encoding.

[0212] S940, IMS network elements (including calling IMS network elements and called IMS network elements) select media type and encoding method.

[0213] The calling side IMS network element and the called side IMS network element exchange information on the media capabilities supported by both UEs, and select the media type and encoding method to be used in this session, i.e., the media type and encoding method supported by both the calling UE and the called UE. In this embodiment, the specific method by which the calling side IMS network element and the called side IMS network element select the media type and encoding method is not limited.

[0214] For example, if the called UE does not support video format, then the audio type and encoding format selected is AMR-WB encoding.

[0215] S950, the called IMS network element sends an INVITE signaling message to the called UE.

[0216] The called IMS network element can send the selected media type and encoding method to the called UE through this INVITE signaling.

[0217] S960, the calling IMS network element feeds back the media type and encoding method to the calling UE.

[0218] The calling IMS network element feeds back the selected media type and encoding method to the calling UE.

[0219] For example, the calling IMS network element can use 100Trying signaling to provide feedback to the calling UE on the selected media type and encoding method.

[0220] S970, the calling UE sends an UPDATE signaling message to the called UE.

[0221] The UPDATE signaling message indicates that the calling party has completed resource reservation. This signaling message may contain SDP information, for example, the SDP information may include the following:

[0222] "a=curr:qos local sendrecv

[0223] a=curr:qos remote none”.

[0224] Among them, "a=curr:qos local sendrecv" can indicate that the local resource reservation of the calling UE (represented by local) has been completed, and sending and receiving are supported; "a=curr:qos remote none" can indicate that the calling UE has not yet confirmed the resource reservation status of the called UE (represented by remote).

[0225] S980, the called UE sends a 200 OK signaling message to the calling UE.

[0226] The 200 OK signaling can indicate a response to an UPDATE request and also signify that the called UE has completed resource reservation. This signaling can include SDP information, for example, the SDP information can include the following:

[0227] "a=curr:qos local sendrecv

[0228] a=curr:qos remote sendrecv".

[0229] In this context, "a=curr:qos local sendrecv" indicates that the resource reservation for the called UE (local) has been completed; "a=curr:qos remote sendrecv" indicates that the called UE has confirmed that the resource reservation for the calling UE (remote) has been completed.

[0230] S990, the called UE sends a 180RINGING signaling message to the calling UE.

[0231] The 180RINGING signaling can indicate that the called UE has initiated a ringing request, and at the same time the calling UE starts ringing.

[0232] In the above embodiments, if the calling UE uses GEO for wireless communication and the called UE uses cellular network for wireless communication, the above method can save 2 SIP signaling calls; if the calling UE uses cellular network for wireless communication and the called UE uses GEO network for wireless communication, the above method can save 3 signaling calls. Therefore, the method in this embodiment can effectively reduce the IMS session establishment latency.

[0233] In some embodiments, the second terminal device can simultaneously instruct the first terminal device via the same signaling: responding to the information sent by the first terminal device indicating that it has completed resource reservation, providing feedback to the first terminal device that it has completed resource reservation, and / or instructing the first terminal device that it has started ringing. The following is in conjunction with... Figure 10 The communication methods in the embodiments of this application are illustrated in detail.

[0234] Figure 10 This is a schematic flowchart of a communication method provided in one embodiment of this application. Figure 10 The method 1000 shown may include step S1010, as follows:

[0235] S1010, the second terminal device sends the fifth information to the first terminal device.

[0236] The fifth message can be used to respond to the sixth message, to instruct the second terminal device to complete resource reservation, and to instruct the second terminal device to start ringing. In other words, the second terminal device can combine the 200 OK signaling and the 180 RINGING signaling into one signaling message and send the combined signaling message to the first terminal device.

[0237] Optionally, the sixth information can be used to instruct the first terminal device to complete resource reservation. For example, the sixth information can be carried in an update request signaling, such as an UPDATE signaling.

[0238] In some embodiments, the fifth information may be carried in the first SIP signaling.

[0239] In some embodiments, the second terminal device can send the fifth information to the first terminal device through the first network element. For example, the second terminal device can send the fifth information to the first network element, and the first network element can forward the fifth information to the first terminal device.

[0240] In some embodiments, the first terminal device may also indicate other completed resource reservations to the second terminal device. For example, before step S1010 above, method 1000 may further include step S1002, as follows:

[0241] S1002, the first terminal device sends the sixth information to the second terminal device.

[0242] In this embodiment, the fifth information is used to respond to the sixth information, to instruct the second terminal device to complete resource reservation, and to instruct the second terminal device to start ringing. The second terminal device sending the fifth information to the first terminal device can reduce the number of signaling interactions, thereby reducing transmission latency.

[0243] The following is combined with Figure 11 The embodiments of method 1000 described above will be illustrated in detail below. It should be noted that, as an example, in method 1100, the first terminal device and the second terminal device communicate via the aforementioned... Figure 2 The illustrated embodiment performs media negotiation. Of course, the first terminal device and the second terminal device can also communicate via the aforementioned... Figure 8 and Figure 9 The embodiments shown involve media negotiation, but this application does not limit this aspect.

[0244] Figure 11 This is a schematic flowchart of a communication method provided in one embodiment of this application. Figure 11 The method 1100 shown may include steps S1110 to S1170.

[0245] S1110, the calling UE sends a REGISTER signaling message to the calling IMS network element, and the called UE sends a REGISTER signaling message to the called IMS network element.

[0246] Both the calling UE and the called UE can register with their respective IMS network elements.

[0247] S1120, the calling UE sends an INVITE signaling message to the called UE.

[0248] The calling UE sends an INVITE signaling message to the called UE. This INVITE signaling message may contain SDP information, which may include the media types and encoding methods supported by the calling UE. For example, the SDP information may include information indicating that the calling UE supports video types with corresponding encoding formats of MPV and H.261, and audio types with corresponding encoding formats of PCMU, G.726, and AMR-WB.

[0249] S1130, the called UE sends a 183 signaling message to the calling UE.

[0250] The 183 signaling indicates that a session is being processed. This 183 signaling may contain SDP information, which may include the called UE's support for the media types and encoding methods supported by the calling UE. For example, the SDP information may indicate that the called UE does not support video but supports AMR-WB and G.726 audio formats.

[0251] S1140, the calling UE sends a PRACK signaling message to the called UE.

[0252] The PRACK signaling indicates a response to the 183 signaling. The calling UE can choose the media type and encoding method for this session based on the media capabilities provided by the called UE (e.g., the called UE does not support video but supports both AMR-WB and G.726 audio formats).

[0253] The PRACK signaling may also include the media type and encoding method selected by the calling UE for this session.

[0254] S1150, the called UE sends a 200 OK signaling message to the calling UE.

[0255] The 200 OK signaling can indicate a response to the PRACK signaling, and can also indicate that the called UE accepts the media type and encoding method selected by the calling UE (i.e., the media type and encoding method selected by the calling UE for this session as indicated in S1140 above).

[0256] S1160, the calling UE sends an UPDATE signaling message to the called UE.

[0257] This UPDATE signaling message indicates that the calling UE has completed resource reservation. This UPDATE signaling message may contain SDP information, for example, the SDP information may include the following:

[0258] "a=curr:qos local sendrecv

[0259] a=curr:qos remote none”.

[0260] Among them, "a=curr:qos local sendrecv" can indicate that the local resource reservation of the calling UE has been completed, and sending and receiving are supported; "a=curr:qos remote none" can indicate that the calling UE has not yet confirmed the resource reservation status of the called UE.

[0261] S1170, the called UE sends the merged SIP signaling to the calling UE.

[0262] The merged SIP signaling can simultaneously possess... Figure 3 The functions of the 200 OK (UPDATE) signaling and 180 RINGING signaling are shown. For example, the combined SIP signaling can indicate that the called UE has received the UPDATE signaling, that the called UE has also completed resource reservation, and that the called UE has started ringing.

[0263] The merged SIP signaling can carry SDP information to indicate that the called UE has accepted (by the calling UE) the modification of media parameters. Simultaneously with sending this SIP signaling, the called UE begins ringing, and the calling UE, upon receiving the SIP signaling, may receive early media (such as a ringback tone).

[0264] For example, the called UE can combine the 200 OK signaling and the 180 RINGING signaling into a single SIP signaling and send the combined SIP signaling to the calling UE.

[0265] The following is an example of a 200 OK signaling message:

[0266] "Status-Line:SIP / 2.0 200OK"

[0267] Message Header

[0268] Via:SIP / 2.0 / TCP[2420:bbbb:3:35:204::3]:5060;

[0269] Call-ID:JNdcbDdAM@[2420:bbbb:3:35:204::3]

[0270] Contact:

[0271] <sip:+8618211000001@[2420:bbbb:3:35:204::3]:5060>;+sip.instance=" <urn:gsma:imei:00000000-000000-0>";+g.3gpp.icsi-ref="urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel";audio;+g.3gpp.mid-call;+g.3gpp.srvcc-alerting

[0272] From:<sip:+8618211000001@ims.3gppnetwork.org>;

[0273] To:"8618211000002"<tel:+8618211000002>;

[0274] Max-Forwards:70

[0275] ...

[0276] Content-Type:application / sdp

[0277] Content-Length:473

[0278] Message Body

[0279] Session Description Protocol

[0280] ...

[0281] Media Attribute(a):curr:qos local sendrecv

[0282] Media Attribute(a):curr:qos remote sendrecv

[0283] Media Attribute(a):des:qos mandatory local sendrecv

[0284] Media Attribute(a):des:qos mandatory remote sendrecv".

[0285] The following is an example of the content of the 180 Ringing signaling:

[0286] "Status-Line:SIP / 2.0 180 Ringing

[0287] Message Header

[0288] Via:SIP / 2.0 / TCP[2420:bbbb:3:35:204::3]:5060;

[0289] Record-Route:<sip:[2420:aaaa:3:0:202::132]:5060;lr>

[0290] Call-ID:JNdcbDdAM@[2420:bbbb:3:35:204::3]

[0291] From:<sip:+8618211000001@ims.3gppnetwork.org> ;

[0292] To: "8618211000002"<tel:+8618211000002> ;

[0293] Content-Length: 0.

[0294] In the examples of the 200 OK and 180 RINGING signaling above, some of the content has the following meaning:

[0295] "Status-Line" indicates the starting line;

[0296] "Message Header" indicates the header field;

[0297] "Via:SIP / 2.0 / TCP[2420:bbbb:3:35:204::3]:5060" records the path traversed by the SIP signaling;

[0298] From:<sip:+8618211000001@ims.3gppnetwork.org> "Indicates the address of the SIP signaling initiator;

[0299] To: "8618211000002"<tel:+8618211000002> "Indicates the address of the SIP signaling receiver;

[0300] "Max-Forwards:70" indicates the maximum number of entities that the SIP signaling can pass through (maximum number of forwards).

[0301] As can be seen from the above example, the content in the header field of the 200 OK signaling is almost identical to the content in the header field of the 180 RINGING signaling. Therefore, merging these two signaling messages into one signaling message can avoid the duplication of many contents.

[0302] The following is an example of the merged SIP signaling content:

[0303] "Status-Line:SIP / 2.0 200OK+180RINGING

[0304] Message Header

[0305] Content-Type:application / sdp

[0306] Via:SIP / 2.0 / TCP[2420:bbbb:3:35:204::3]:5060;

[0307] Call-ID:JNdcbDdAM@[2420:bbbb:3:35:204::3]

[0308] From:<sip:+8618211000001@ims.3gppnetwork.org>;

[0309] To:"8618211000002"<tel:+8618211000002>;

[0310] Content-Length:473

[0311] …

[0312] Message Body

[0313] Session Description Protocol

[0314] …

[0315] Media Attribute(a):curr:qos local sendrecv

[0316] Media Attribute(a):curr:qos remote sendrecv

[0317] Media Attribute(a):des:qos mandatory local sendrecv

[0318] Media Attribute(a):des:qos mandatory remote sendrecv”

[0319] In this context, "200OK+180RINGING" in the first line of the merged SIP signaling indicates the name of the merged SIP signaling. It should be noted that this name is merely an example and not a limitation; the merged SIP signaling may also be represented by other names, and this embodiment of the application does not limit this.

[0320] It can be seen that the size (number of bytes) of the merged SIP signaling is significantly smaller than the sum of the sizes of the 200 OK signaling and the 180 RINGING signaling, thus effectively reducing redundant information in the transmission.

[0321] The above text combined Figures 1 to 11 The method embodiments of this application are described in detail below, in conjunction with... Figures 12 to 17 The present application provides a detailed description of the apparatus embodiments. It should be understood that the descriptions of the method embodiments correspond to the descriptions of the apparatus embodiments; therefore, any parts not described in detail can be found in the foregoing method embodiments.

[0322] Figure 12 This is a schematic structural diagram of a communication device provided in an embodiment of this application. Figure 12 The communication device 1200 shown can be used in the first terminal device in the foregoing embodiments. The communication device 1200 can be the first terminal device, or a device in the first terminal device (e.g., a processor, chip, chip system, circuit or a functional module, etc.), or a device that can be matched with the first terminal device, or a logic module or software that can implement all or part of the first terminal device.

[0323] like Figure 12 As shown, the communication device 1200 includes a transmitting unit 1210 and a receiving unit 1220, as detailed below:

[0324] The sending unit 1210 is used to send first information, the first information being used to indicate the first media capability of the first terminal device;

[0325] The sending unit 1210 is used to send second information, which is used to invite the second terminal device to join the Internet Protocol Multimedia Subsystem (IMS) session.

[0326] The receiving unit 1220 is used to receive third information, which is used to indicate the media capabilities jointly supported by the first terminal device and the second terminal device.

[0327] In some possible implementations, before sending the second information, the sending unit 1210 is further configured to send a fourth information, the fourth information being used to update the first media capability.

[0328] In some possible implementations, the fourth information is used to indicate a second media capability of the first terminal device, the second media capability being a dynamic media capability supported by the first terminal device, the second media capability including one or more of the following: media type, encoding method, or bandwidth.

[0329] In some possible implementations, the first information is carried in the first registration request message.

[0330] In some possible implementations, the third information is also used to respond to the second information.

[0331] In some possible implementations, the receiving unit 1220 is further configured to: receive fifth information, the fifth information being used for one or more of the following: responding to sixth information, instructing the second terminal device to complete resource reservation, or instructing the second terminal device to start ringing; wherein the sixth information is used to instruct the first terminal device to complete resource reservation.

[0332] In some possible implementations, the fifth information is carried in the first session initiation protocol (SIP) signaling.

[0333] In some possible implementations, the first media capability is a static media capability supported by the first terminal device, and the first media capability includes one or more of the following: media type, encoding method, or bandwidth.

[0334] Figure 13 This is a schematic structural diagram of a communication device provided in an embodiment of this application. Figure 13 The communication device 1300 shown can be used in the second terminal device in the foregoing embodiments. The communication device 1300 can be the second terminal device, or a device in the second terminal device (e.g., a processor, chip, chip system, circuit or a functional module, etc.), or a device that can be used in conjunction with the second terminal device, or a logic module or software that can implement all or part of the second terminal device.

[0335] like Figure 13 As shown, the communication device 1300 includes a transmitting unit 1310 and a receiving unit 1320, as detailed below:

[0336] The sending unit 1310 is used to send seventh information, which is used to indicate the third media capability of the second terminal device;

[0337] The receiving unit 1320 is used to receive eighth information, which is used to indicate the media capabilities jointly supported by the first terminal device and the second terminal device.

[0338] In some possible implementations, before receiving the eighth information, the sending unit 1310 is further configured to: send a ninth information, the ninth information being used to update the third media capability.

[0339] In some possible implementations, the ninth information is used to indicate the fourth media capability of the second terminal device, which is a dynamic media capability supported by the second terminal device, and the fourth media capability includes one or more of the following: media type, encoding method, or bandwidth.

[0340] In some possible implementations, the seventh information is carried in the second registration request message.

[0341] In some possible implementations, the eighth information is also used to instruct the first terminal device to invite the second terminal device to join an Internet Protocol Multimedia Subsystem (IMS) session.

[0342] In some possible implementations, the sending unit 1310 is further configured to: send a fifth message, the fifth message being used for one or more of the following: responding to a sixth message, instructing the second terminal device to complete resource reservation, or instructing the second terminal device to start ringing; wherein the sixth message is used to instruct the first terminal device to complete resource reservation.

[0343] In some possible implementations, the fifth information is carried in the first session initiation protocol (SIP) signaling.

[0344] In some possible implementations, the third media capability is a static media capability supported by the second terminal device, and the third media capability includes one or more of the following: media type, encoding method, or bandwidth.

[0345] Figure 14 This is a schematic structural diagram of a communication device provided in an embodiment of this application. Figure 14 The communication device 1400 shown can be used in the first network element in the foregoing embodiments. The communication device 1400 can be the first network element, or a device in the first network element (e.g., a processor, chip, chip system, circuit or a functional module, etc.), or a device that can be matched with the first network element, or a logic module or software that can implement all or part of the first network element.

[0346] like Figure 14 As shown, the communication device 1400 includes a receiving unit 1410 and a transmitting unit 1420, as detailed below:

[0347] The receiving unit 1410 is configured to receive first information and seventh information, wherein the first information is used to indicate the first media capability of the first terminal device and the seventh information is used to indicate the third media capability of the second terminal device.

[0348] The receiving unit 1410 is used to receive second information, which is used to invite the second terminal device to join the Internet Protocol Multimedia Subsystem (IMS) session.

[0349] The sending unit 1420 is used to send third information and eighth information, wherein the third information is used to indicate media capabilities jointly supported by the first terminal device and the second terminal device, and the eighth information is used to indicate media capabilities jointly supported by the first terminal device and the second terminal device.

[0350] In some possible implementations, the communication device 1400 further includes a determining unit 1430, which, before sending the third and eighth information, is configured to: determine, based on the first and seventh information, the media capabilities commonly supported by the first terminal device and the second terminal device.

[0351] In some possible implementations, before receiving the second information, the receiving unit 1410 is further configured to: receive fourth information, the fourth information being used to update the first media capability.

[0352] In some possible implementations, the fourth information is used to indicate a second media capability of the first terminal device, the second media capability being a dynamic media capability supported by the first terminal device, the second media capability including one or more of the following: media type, encoding method, or bandwidth.

[0353] In some possible implementations, before receiving the second information, the receiving unit 1410 is further configured to: receive a ninth information, the ninth information being used to update the third media capability.

[0354] In some possible implementations, the ninth information is used to indicate the fourth media capability of the second terminal device, which is a dynamic media capability supported by the second terminal device, and the fourth media capability includes one or more of the following: media type, encoding method, or bandwidth.

[0355] In some possible implementations, the first information is carried in a first registration request message, and / or the seventh information is carried in a second registration request message.

[0356] In some possible implementations, the third information is also used to respond to the second information, and / or the eighth information is also used to instruct the first terminal device to invite the second terminal device to join the IMS session.

[0357] In some possible implementations, the first media capability is a static media capability supported by the first terminal device, and the first media capability includes one or more of the following: media type, encoding method, or bandwidth; and / or, the third media capability is a static media capability supported by the second terminal device, and the third media capability includes one or more of the following: media type, encoding method, or bandwidth.

[0358] Figure 15 This is a schematic structural diagram of a communication device provided in an embodiment of this application. Figure 15 The communication device 1500 shown can be used in the first terminal device in the foregoing embodiments. The communication device 1500 can be the first terminal device, or a device in the first terminal device (e.g., a processor, chip, chip system, circuit or a functional module, etc.), or a device that can be matched with the first terminal device, or a logic module or software that can implement all or part of the first terminal device.

[0359] like Figure 15 As shown, the communication device 1500 includes a receiving unit 1510, specifically as follows:

[0360] The receiving unit 1510 is used to receive fifth information, which is used to respond to sixth information, to instruct the second terminal device to complete resource reservation, and to instruct the second terminal device to start ringing; wherein, the sixth information is used to instruct the first terminal device to complete resource reservation.

[0361] In some possible implementations, the fifth information is carried in the first session initiation protocol (SIP) signaling.

[0362] Figure 16 This is a schematic structural diagram of a communication device provided in an embodiment of this application. Figure 16 The communication device 1600 shown can be used in the second terminal device in the foregoing embodiments. The communication device 1600 can be the second terminal device, or a device in the second terminal device (e.g., a processor, chip, chip system, circuit or a functional module, etc.), or a device that can be used in conjunction with the second terminal device, or a logic module or software that can implement all or part of the second terminal device.

[0363] like Figure 16 As shown, the communication device 1600 includes a transmitting unit 1610, specifically as follows:

[0364] The sending unit 1610 is used to send fifth information, which is used to respond to the sixth information, to instruct the second terminal device to complete resource reservation, and to instruct the second terminal device to start ringing.

[0365] The sixth piece of information is used to instruct the first terminal device to complete resource reservation.

[0366] In some possible implementations, the fifth information is carried in the first session initiation protocol (SIP) signaling.

[0367] Figure 17 This is a schematic structural diagram of a device provided in an embodiment of this application. Figure 17 The dashed lines indicate that the unit or module is optional. The device 1700 can be used to implement the methods described in the above method embodiments. The device 1700 can be a chip or a communication device.

[0368] Apparatus 1700 may include one or more processors 1710. The processor 1710 may support apparatus 1700 in implementing the methods described in the preceding method embodiments. The processor 1710 may be a general-purpose processor or a special-purpose processor. For example, the processor may be a central processing unit (CPU). Alternatively, the processor may be other general-purpose processors, microprocessor units (MPUs), microcontroller units (MCUs), graphics processing units (GPUs), artificial intelligence processors (AI processors) or neural processing units (NPUs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0369] The device 1700 may also include one or more memories 1720. The memories 1720 store a program that can be executed by the processor 1710, causing the processor 1710 to perform the methods described in the preceding method embodiments. The memories 1720 may be independent of the processor 1710 or integrated within the processor 1710. In this embodiment, the memories 1720 may include, but are not limited to, cache, read-only memory (ROM), random access memory (RAM), synchronous dynamic random access memory (SDRAM), hard disk drive (HDD) or solid-state drive (SSD), erasable programmable read-only memory (EPROM), or compact disc read-only memory (CD-ROM), etc.

[0370] The device 1700 may also include a transceiver 1730. The processor 1710 can communicate with other devices or chips via the transceiver 1730. For example, the processor 1710 can send and receive data with other devices or chips via the transceiver 1730.

[0371] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0372] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0373] This application also provides a computer-readable storage medium storing a computer program that, when run on a computer, causes the computer to perform the steps described in the various method embodiments above.

[0374] This application also provides a computer program product, which includes a computer program that, when run on a computer, causes the computer to perform the steps described in the various method embodiments above.

[0375] This application also provides a chip, which includes a processor and a memory. The memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory, so that a device or equipment (such as a communication device) with the chip installed performs the steps in the above-described method embodiments.

[0376] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable storage medium can include at least: any entity or device capable of carrying computer program code to a device / app, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks. In some jurisdictions, according to legislation and patent practice, a computer-readable storage medium may not be an electrical carrier signal or a telecommunication signal.

[0377] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0378] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0379] In the embodiments provided in this application, it should be understood that the disclosed apparatus / devices and methods can be implemented in other ways. For example, the apparatus / device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0380] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0381] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A communication method, characterized in that, The method is applied to a first terminal device, and the method includes: Send first information, the first information being used to indicate the first media capability of the first terminal device; Send a second message, which is used to invite the second terminal device to join the Internet Protocol Multimedia Subsystem (IMS) session; Receive third information, which is used to indicate the media capabilities jointly supported by the first terminal device and the second terminal device.

2. The method according to claim 1, characterized in that, Before sending the second information, the method further includes: Send a fourth message, which is used to update the first media capability.

3. The method according to claim 2, characterized in that, The fourth information is used to indicate the second media capability of the first terminal device. The second media capability is the dynamic media capability supported by the first terminal device. The second media capability includes one or more of the following: media type, encoding method, or bandwidth.

4. The method according to any one of claims 1 to 3, characterized in that, The first information is carried in the first registration request message.

5. The method according to any one of claims 1 to 4, characterized in that, The third information is also used to respond to the second information.

6. The method according to any one of claims 1 to 5, characterized in that, The method further includes: Receive fifth information, which is used for one or more of the following: The system responds to the sixth message, instructs the second terminal device to complete resource reservation, or instructs the second terminal device to start ringing. The sixth piece of information is used to instruct the first terminal device to complete resource reservation.

7. The method according to claim 6, characterized in that, The fifth piece of information is carried in the first session initiation protocol (SIP) signaling.

8. The method according to any one of claims 1 to 7, characterized in that, The first media capability is the static media capability supported by the first terminal device, and the first media capability includes one or more of the following: media type, encoding method, or bandwidth.

9. A communication method, characterized in that, The method is applied to a second terminal device, and the method includes: Send a seventh message, the seventh message being used to indicate the third media capability of the second terminal device; Receive the eighth message, which is used to indicate the media capabilities jointly supported by the first terminal device and the second terminal device.

10. The method according to claim 9, characterized in that, Before receiving the eighth information, the method further includes: Send a ninth message, which is used to update the third media capability.

11. The method according to claim 10, characterized in that, The ninth information is used to indicate the fourth media capability of the second terminal device. The fourth media capability is a dynamic media capability supported by the second terminal device, and the fourth media capability includes one or more of the following: media type, encoding method, or bandwidth.

12. The method according to any one of claims 9 to 11, characterized in that, The seventh piece of information is carried in the second registration request message.

13. The method according to any one of claims 9 to 12, characterized in that, The eighth piece of information is also used to instruct the first terminal device to invite the second terminal device to join the Internet Protocol Multimedia Subsystem (IMS) session.

14. The method according to any one of claims 9 to 13, characterized in that, The method further includes: Send a fifth message, which is used for one or more of the following: The system responds to the sixth message, instructs the second terminal device to complete resource reservation, or instructs the second terminal device to start ringing. The sixth piece of information is used to instruct the first terminal device to complete resource reservation.

15. The method according to claim 14, characterized in that, The fifth piece of information is carried in the first session initiation protocol (SIP) signaling.

16. The method according to any one of claims 1 to 15, characterized in that, The third media capability is the static media capability supported by the second terminal device, and the third media capability includes one or more of the following: media type, encoding method, or bandwidth.

17. A communication method, characterized in that, The method is applied to a first network element, and the method includes: Receive first information and seventh information, wherein the first information is used to indicate the first media capability of the first terminal device, and the seventh information is used to indicate the third media capability of the second terminal device; Receive a second message, which is used to invite the second terminal device to join the Internet Protocol Multimedia Subsystem (IMS) session; Send a third message and an eighth message, wherein the third message is used to indicate the media capabilities jointly supported by the first terminal device and the second terminal device, and the eighth message is used to indicate the media capabilities jointly supported by the first terminal device and the second terminal device.

18. The method according to claim 17, characterized in that, Before sending the third and eighth messages, the method further includes: The media capabilities jointly supported by the first terminal device and the second terminal device are determined based on the first information and the seventh information.

19. The method according to claim 17 or 18, characterized in that, Before receiving the second information, the method further includes: Receive fourth information, which is used to update the first media capability.

20. The method according to claim 19, characterized in that, The fourth information is used to indicate the second media capability of the first terminal device. The second media capability is the dynamic media capability supported by the first terminal device. The second media capability includes one or more of the following: media type, encoding method, or bandwidth.

21. The method according to any one of claims 17 to 20, characterized in that, Before receiving the second information, the method further includes: Receive the ninth message, which is used to update the third media capability.

22. The method according to claim 21, characterized in that, The ninth information is used to indicate the fourth media capability of the second terminal device. The fourth media capability is a dynamic media capability supported by the second terminal device, and the fourth media capability includes one or more of the following: media type, encoding method, or bandwidth.

23. The method according to any one of claims 17 to 22, characterized in that, The first information is carried in the first registration request message, and / or the seventh information is carried in the second registration request message.

24. The method according to any one of claims 17 to 23, characterized in that, The third information is also used to respond to the second information, and / or the eighth information is also used to instruct the first terminal device to invite the second terminal device to join the IMS session.

25. The method according to any one of claims 17 to 24, characterized in that, The first media capability is the static media capability supported by the first terminal device, and the first media capability includes one or more of the following: media type, encoding method, or bandwidth; and / or, The third media capability is the static media capability supported by the second terminal device, and the third media capability includes one or more of the following: media type, encoding method, or bandwidth.

26. A communication device, characterized in that, include: A module or unit for performing the method as described in any one of claims 1 to 25.

27. A communication device, characterized in that, include: A processor and a memory, the processor being coupled to the memory, the memory being used to store a computer program, which, when executed by the processor, causes the apparatus to perform the method as described in any one of claims 1 to 25.

28. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when run on a computer, causes the computer to perform the method as described in any one of claims 1 to 25.

29. A computer program product, characterized in that, include: A computer program that, when run on a computer, causes the computer to perform the method as described in any one of claims 1 to 25.

30. A chip, characterized in that, include: A processor and a memory, the memory for storing a computer program, the processor for calling and running the computer program stored in the memory, causing a device or apparatus on which the chip is mounted to perform the method as described in any one of claims 1 to 25.

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