Communication method and apparatus

Abstract

A communication method and apparatus, relating to the technical field of communications. In the method, after a terminal and a first network element (e.g., a P-CSCF) in an IMS network perform one negotiation of compression processing capability and / or of compression enablement during registration, SIP messages sent between the terminal and the P-CSCF in subsequent call establishment procedures no longer carry "comp=sigcomp"; instead, a compression operation is performed by default on the messages, or whether to perform the compression operation is determined on the basis of an access mode of the terminal. In this way, the size of SIP messages transmitted over the air interface in a satellite network is reduced, and call delay is shortened.

Description

Communication methods and devices

[0001] This application claims priority to Chinese Patent Application No. 202510380151.2, filed on March 27, 2025, entitled "Communication Method and Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, and in particular to a communication method and apparatus. Background Technology

[0003] With the development of satellite mobile communication systems, supporting voice services in narrowband high-orbit satellite systems has become an industry trend. The current 3rd Generation Partnership Project (3GPP) standard defines the call setup process for initiating voice or video services through terrestrial networks. This process establishes a call between the calling and called parties, enabling voice or video calls. During the call setup process, the interaction between the terminal and the proxy call session control function (P-CSCF) network element in the IP multimedia subsystem (IMS) network uses the Session Initiation Protocol (SIP) message format. However, SIP message payloads are typically large, while satellite network transmission bandwidth is limited. Therefore, compared to terrestrial networks, how to reduce the message size transmitted during call setup in satellite networks is a problem that needs to be studied. Summary of the Invention

[0004] This application provides a communication method and apparatus that can reduce the transmission overhead of the air interface in satellite networks and shorten call latency.

[0005] The present application is described below from different aspects. It should be understood that the different implementation methods and beneficial effects described below can be referenced from each other.

[0006] Firstly, this application provides a communication method that can be applied to a terminal-side communication device, such as a terminal or a communication module / processing module within a terminal, or a circuit or chip in the terminal responsible for communication functions (such as a modem chip, also known as a baseband chip, or a system-on-chip (SoC) chip containing a modem core, or a system-in-package (SIP) chip), or a circuit or chip in the terminal responsible for processing functions (such as a graphics processing unit (GPU), an artificial intelligence (AI) processor, or an application-specific integrated circuit (ASIC)). Taking the application of this method to a terminal as an example, the terminal sends a registration request message to a first network element in the IMS network. The registration request message includes first information, which is used to indicate that the terminal supports the compression processing capability of a first message, and / or, the first information is used to indicate that the terminal requests to perform a compression operation on the first message. The terminal receives a registration response message from a first network element. This registration response message includes second information, which instructs the first network element to support the compression processing capability of the first message, and / or instructs the first network element to perform a compression operation on the first message. Optionally, the second information instructing the first network element to perform a compression operation on the first message can also be described as the second information instructing the first network element to accept / accept activation / agree / agree to activate the compression operation on the first message. In this application, the terminal communicates via a non-terrestrial network, and the first message is a message transmitted between the terminal and the first network element.

[0007] Optionally, the aforementioned first network element may be, for example, a P-CSCF in an IMS network, and is not limited thereto. For example, to reduce the size of transmitted SIP messages, a commonly used compression method is signaling compression (sigcomp). Optionally, the compression method involved in this application may also be other compression methods, and is not limited thereto. For ease of understanding, the following description will primarily use sigcomp as the compression method. It should be noted that, unlike existing technologies that require carrying comp=sigcomp in every SIP message during the call setup process to indicate / enable compression, in this embodiment, the terminal and the first network element (e.g., P-CSCF) in the IMS network only need to negotiate compression processing capability and / or compression enable once during the registration process (or before the call setup process). This means that the SIP messages sent between the terminal and the P-CSCF during the subsequent call setup process no longer carry comp=sigcomp, but instead perform message compression by default or determine whether to perform compression based on the terminal's access method. Therefore, the size of SIP messages transmitted over the air interface in the satellite network can be reduced, and call latency can be shortened.

[0008] In one possible implementation, the method further includes:

[0009] A first uplink message is sent, which does not include information about compressing the first downlink message. The first uplink message and the first downlink message are part of the first message. Furthermore, this first uplink message is a compressed message, such as a message after performing sigcomp.

[0010] In this implementation, after the terminal performs a negotiation on compression processing capability and / or compression enable during the registration process, it can determine that the network supports / accepts the activation of compression function. Therefore, the terminal can send a first uplink message that has been compressed to the first network element. The first uplink message does not include information on the compression processing of the first downlink message, such as not carrying comp=sigcomp. This can reduce the transmission overhead of the air interface under the satellite network and shorten the call latency.

[0011] In one possible implementation, the first uplink message does not include information on performing compression processing on the first downlink message, including: the Via header field, Contact header field, Route header field, or Record-Route header field of the first uplink message do not include information on performing compression processing on the first downlink message.

[0012] In this implementation, the routing parameters do not include information on performing compression processing on the first downlink message, such as not including comp=sigcomp, which reduces transmission overhead.

[0013] In one possible implementation, the first uplink message also includes the terminal's access method;

[0014] When the first information is used to indicate that the terminal supports the compression processing capability of the first message, the access method of the terminal is used to determine whether to perform a compression operation on the first downlink message.

[0015] In this implementation, if the terminal supports compression processing capabilities, the decision to perform compression operations can be further determined based on the terminal's access method. This allows for flexible control over the activation of compression operations and better adapts to actual needs.

[0016] In one possible implementation, the method further includes:

[0017] A second downlink message is received. This second downlink message does not include information about compressing the second uplink message. Both the second downlink message and the second uplink message are part of the first message. Furthermore, this second downlink message is a compressed message, such as a message after performing sigcomp.

[0018] In this implementation, the second downlink message does not include information on compressing the second uplink message, such as not carrying comp=sigcomp. This reduces the transmission overhead of the air interface in the satellite network and shortens the call latency.

[0019] In one possible implementation, sending the registration request message to the first network element in the IMS network includes:

[0020] When the terminal accesses the network via high-orbit satellite or narrowband high-orbit satellite, it sends the registration request message to the first network element in the IMS network.

[0021] In this implementation, since the terminal access method is through high-orbit satellite or narrowband high-orbit satellite, the transmission rate is relatively low, and the impact of the above-mentioned call latency is greater. Therefore, by performing the negotiation of compression processing capability and / or compression enable negotiation during the registration process, it is beneficial to reduce the transmission overhead in the subsequent call establishment process, thereby reducing call latency.

[0022] In one possible implementation, the registration response message is a 200 OK message, and the second information is carried in the Feature Caps field of the 200 OK message.

[0023] In this implementation, carrying second information in the Feature Caps field is beneficial for protocol compatibility.

[0024] In one possible implementation, the first information is carried in the Contact field of the registration request message.

[0025] In this implementation, carrying the first piece of information in the Contact field is beneficial for protocol compatibility.

[0026] Secondly, this application provides a communication method that can be applied to network-side communication devices, such as a first network element in an IMS network, or a module (e.g., circuit, chip, or chip system) within the first network element, or a logical node, logical module, or software capable of implementing all or part of the functions of the first network element. Taking the application of this method to a first network element as an example, in this method, the first network element receives a registration request message from a terminal. The registration request message includes first information, which indicates that the terminal supports the compression processing capability of a first message, and / or, the first information indicates that the terminal requests to perform a compression operation on the first message. The terminal communicates through a non-terrestrial network, and the first message is a message transmitted between the terminal and the first network element. The first network element sends a registration response message to the terminal. The registration response message includes second information, which indicates that the first network element supports the compression processing capability of the first message, and / or, the second information indicates that the first network element performs a compression operation on the first message.

[0027] In one possible implementation, after receiving the registration response message from the first network element, the method further includes:

[0028] A first uplink message is received, which does not include information on performing compression processing on a first downlink message. The first uplink message and the first downlink message belong to the first message.

[0029] In one possible implementation, the first uplink message does not include information on performing compression processing on the first downlink message, including: the Via header field, Contact header field, Route header field, or Record-Route header field of the first uplink message does not include information on performing compression processing on the first downlink message.

[0030] In one possible implementation, the first uplink message further includes the terminal's access method; the method further includes:

[0031] Whether to perform compression operation on the first downlink message is determined based on the access method of the terminal.

[0032] In this implementation, the decision to perform compression on the first downlink message is made by using the access method of the terminal carried in the uplink message sent by the multiplexed terminal, which is simple to implement.

[0033] In one possible implementation, the method further includes:

[0034] Send a first request message to the core network element, the first request message being used to request the terminal's access method;

[0035] Receive a first response message from the core network element, wherein the first response message includes the access method of the terminal;

[0036] Whether to perform compression operation on the first downlink message is determined based on the access method of the terminal.

[0037] This implementation method allows for easy access to terminals by interacting with core network elements.

[0038] In one possible implementation, determining whether to perform compression on the first downlink message based on the terminal's access method includes:

[0039] If the terminal accesses the network via a high-orbit satellite or a narrowband high-orbit satellite, it is determined that a compression operation will be performed on the first downlink message.

[0040] In one possible implementation, the method further includes:

[0041] Send a second downlink message, which does not include information on performing compression processing on the second uplink message. The second downlink message and the second uplink message belong to the first message.

[0042] In one possible implementation, the registration response message is a 200 OK message, and the second information is carried in the Feature Caps field of the 200 OK message.

[0043] In one possible implementation, the first information is carried in the Contact field of the registration request message.

[0044] Thirdly, this application provides a communication device comprising units, modules, or means for implementing any of the methods in the first to second aspects, or any possible implementations of any of the aspects, wherein the modules, units, or means may be implemented by software, by hardware, or by a combination of software and hardware.

[0045] Fourthly, this application provides a communication device including a processor. The processor is configured to cause the communication device to implement the methods shown in any of the first to second aspects, or any possible implementation thereof.

[0046] Optionally, the communication device further includes a transceiver for sending and receiving information.

[0047] Optionally, the communication device further includes a memory storing a computer program; the processor and transceiver are used to invoke the computer program in the memory, causing the communication device to implement the method shown in any of the first or second aspects, or any possible implementation thereof.

[0048] In one possible design, the communication device can be a chip that implements the above method or a device containing a chip.

[0049] Fifthly, this application provides a communication device comprising one or more processors, which implement, via logic circuits or execution code instructions, any of the methods described in the first or second aspects, or any possible implementation thereof.

[0050] Optionally, the communication device further includes an interface circuit for receiving signals from other communication devices outside the communication device and transmitting them to the processor, or sending signals from the processor to other communication devices outside the communication device.

[0051] Optionally, the communication device may further include a memory for storing part or all of the computer programs or instructions necessary to implement the functions involved in the first aspect above.

[0052] The aforementioned communication device may be a terminal, a communication module in a terminal, or a chip in a terminal that is responsible for communication functions, such as a modem chip (also known as a baseband chip) or a SoC or SIP chip that contains a modem module.

[0053] The aforementioned communication device may be a first network element, a module (e.g., a circuit, chip, or chip system) within the first network element, or a logic node, logic module, or software capable of implementing all or part of the functions of the first network element.

[0054] Sixthly, this application provides a computer-readable storage medium storing a computer program or instructions that, when executed by a computer, implement the method shown in any of the first to second aspects, or any possible implementation thereof.

[0055] In a seventh aspect, this application provides a computer program product that, when read and executed by a computer, causes the computer to perform any of the methods in the first aspect to the second aspect, or any possible implementation thereof.

[0056] Eighthly, this application provides a chip system including at least one processor and an interface, the processor being configured to read and execute a computer program or instructions in a memory, wherein when the computer program or instructions are executed, the chip performs the method as described in any one of the first or second aspects, or the method shown in any possible implementation of either aspect.

[0057] Ninthly, this application provides a communication system that may include a terminal and a first network element. The terminal is used to perform the method shown in the first aspect or any possible implementation thereof. The first network element is used to perform the method shown in the second aspect or any possible implementation thereof. Attached Figure Description

[0058] Figure 1 is a schematic diagram of the architecture of the communication system used in the embodiments of this application;

[0059] Figure 2 is a schematic diagram of the 4G network architecture;

[0060] Figure 3 is a schematic diagram of the 5G network architecture;

[0061] Figure 4 is a schematic diagram of the call setup process;

[0062] Figure 5 is a flowchart illustrating a communication method provided in an embodiment of this application;

[0063] Figure 6A is a schematic diagram of a scenario of the communication method provided in an embodiment of this application;

[0064] Figure 6B is a schematic diagram of another scenario of the communication method provided in the embodiment of this application;

[0065] Figure 6C is a schematic diagram of another scenario of the communication method provided in the embodiments of this application;

[0066] Figure 7 is a schematic diagram of the structure of a possible communication device provided in an embodiment of this application;

[0067] Figure 8 is a schematic diagram of the structure of a possible communication device provided in an embodiment of this application;

[0068] Figure 9 is a schematic diagram of the structure of a possible communication device provided in an embodiment of this application. Detailed Implementation

[0069] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0070] In the description of this application, terms such as "first" and "second" are used only to distinguish different objects, not to describe a specific order. Furthermore, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in this document is merely a description of 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. Additionally, "at least one" refers to one or more, and "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 multiple items. For example, at least one of a, b, or c can represent: a, b, c; a and b; a and c; b and c; or a and b and c. Where a, b, and c can be single or multiple.

[0071] The terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0072] In this application, the words "exemplary" or "for example" are used to indicate that something is an example, illustration, or illustration. Any embodiment or design described as "exemplary," "for example," or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Rather, the use of the words "exemplary," "for example," or "for example" is intended to present the relevant concepts in a specific manner.

[0073] It is understood that in this application, "when," "if," and "if" all refer to the device making a corresponding action under certain objective circumstances, and are not time-limited, nor do they require the device to make a judgment when it is implemented, nor do they imply any other limitations.

[0074] In this application, the use of singular pronouns for elements is intended to indicate "one or more," rather than "one and only one," unless otherwise specified. The terms "system" and "network" in the embodiments of this application are used interchangeably.

[0075] It is understood that in the embodiments of this application, "B corresponding to A" means that there is a correspondence between A and B, and B can be determined based on A. Determining B based on A does not mean that B is determined solely based on A; B can also be determined based on A and / or other information.

[0076] To better understand the embodiments of this application, the system architecture involved in the embodiments of this application will be described first below:

[0077] The technical solution of this application can be applied to scenarios involving non-terrestrial networks (NTN) or the convergence of NTN and terrestrial networks (TN). NTN systems can be, for example, satellite communication systems, high altitude platform station (HAPS) communication systems, global navigation satellite systems (GNSS), etc. TN systems can be, for example, 4th generation (4G) communication systems (e.g., long term evolution (LTE) systems), worldwide interoperability for microwave access (WiMAX) communication systems, 5th generation (5G) communication systems (e.g., new radio (NR) systems), and future mobile communication systems. The convergence of NTN and TN can be satellite-terrestrial convergence, etc., and is not limited to these scenarios.

[0078] The following explanation uses the system architecture shown in Figure 1 as an example. Please refer to Figure 1, which is a schematic diagram of the communication system architecture used in the embodiments of this application. It should be noted that Figure 1 is a possible, non-limiting system schematic diagram. As shown in Figure 1, a terminal (e.g., user equipment (UE)) can access a 4G / 5G network (evolved packet system (EPS) / 5G system (5GS, 5G System) as described in the dashed box in Figure 1) via satellite, and then transmit voice call control messages between the terminal and the IMS network, as well as data packets for the call, through the 4G / 5G network to perform voice services.

[0079] The IMS network may include a proxy call session control function (P-CSCF) and a serving call session control function (S-CSCF). The P-CSCF in the IMS network is the first access point, behaving like a proxy, primarily accepting requests and providing internal services or forwarding requests upwards. The S-CSCF in the IMS network is mainly used to perform session control services for the UE, maintaining session state according to the network operator's needs to support services.

[0080] Optionally, the system architecture used in this application can be other future network architectures besides the aforementioned 4G / 5G network architecture. The following description uses Figures 2 and 3 as examples to illustrate the applicable 4G / 5G network architecture.

[0081] For example, as shown in Figure 2, taking a 4G network architecture (e.g., EPS) as an example, it mainly includes UE, 4G access network equipment (e.g., evolved universal terrestrial radio access network, E-UTRAN), and 4G core network elements (e.g., mobility management entity, Serving Gateway, packet data network (PDN) gateway, etc.).

[0082] For example, as shown in Figure 3, taking the 5G network architecture (e.g., 5GS) as an example, it mainly includes UE, 5G access network equipment (e.g., radio access network (R)AN) and 5G core network elements (e.g., access and mobility management function (AMF), session management function (SMF), user plane function (UPF, etc.)).

[0083] 5G access network equipment, also known as RAN nodes, and sometimes as radio access network equipment, access network devices, access network devices, RAN entities, or access nodes, constitutes part of a communication system to help terminals achieve wireless access. In one possible scenario, an RAN node can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a base station in a future mobile communication system, or an access node in a WiFi system. RAN nodes can be macro base stations, micro base stations, indoor stations, relay nodes, donor nodes, or radio controllers in CRAN scenarios. Optionally, RAN nodes can also be servers, wearable devices, vehicles, or in-vehicle equipment. For example, the access network device in vehicle-to-everything (V2X) technology can be a roadside unit (RSU). All or part of the functions of the RAN node in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (e.g., a cloud platform). The RAN node in this application can also be a logical node, logical module, or software that can implement all or part of the functions of the RAN node.

[0084] In another possible scenario, multiple RAN nodes collaborate to assist the terminal in achieving wireless access, with different RAN nodes each implementing a portion of the base station's functions. For example, RAN nodes can be centralized units (CUs), distributed units (DUs), CU-control plane (CPs), CU-user plane (UPs), or radio units (RUs), 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 equipment or radio units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs).

[0085] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called O-CU (open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples. Any of the units among 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.

[0086] In some examples, the CU is a logical node carrying the radio resource control (RRC) layer, service data adaptation protocol (SDAP) layer, packet data convergence protocol (PDCP) layer, and other control functions of the access network device. The CU connects to network nodes such as the core network through interfaces, which may be interfaces such as E2 interfaces. Optionally, the CU may have some core network functions. The CU (e.g., the PDCP layer and higher layers) connects to the DU (e.g., the RLC layer and lower layers) through interfaces, which may be interfaces such as the F1 interface. In some examples, these interfaces (e.g., the F1 interface) can provide control plane (C-Plane) and user plane (U-Plane) functions (e.g., interface management, system information management, UE context management, RRC message transmission, etc.). F1AP is the application protocol of the F1 interface, defining the F1 signaling procedures in some examples. The F1 interface supports control plane F1-C and user plane F1-U.

[0087] In some examples, the CU can be split into CU-CP (control unit-control plane) and CU-UP (control unit-user plane). CU-CP is a logical node carrying the RRC layer and PDCP-C (control plane part of PDCP) layer, used to implement the CU's control plane functions. CU-CP can interact with network elements in the core network used to implement control plane functions. These network elements in the core network can be access and mobility function (AMF) network elements, such as the access and mobility management function (AMF) in a 5G system. The AMF network element is responsible for mobility management in the mobile network, such as terminal location updates, terminal registration with the network, and terminal handover. CU-UP is a logical node carrying the SDAP layer and PDCP-U (user plane part of PDCP) layer, used to implement the CU's user plane functions. CU-UP can interact with network elements in the core network used to implement user plane functions. These network elements in the core network, such as the user plane function (UPF) in a 5G system, are responsible for data forwarding and receiving in the terminal. The above CU and DU configurations are merely examples; the functions of the CU and DU can be configured as needed. For instance, the CU or DU can be configured to have more protocol layer functions, or only some protocol layer processing functions. For example, some RLC layer functions and protocol layer functions above the RLC layer can be placed in the CU, while the remaining RLC layer functions and protocol layer functions below the RLC layer can be placed in the DU. Furthermore, the functions of the CU or DU can be divided according to service type or other system requirements, such as by latency. Functions that require low latency can be placed in the DU, while functions that do not require low latency can be placed in the CU.

[0088] In some examples, a DU is a logical node that carries the radio link control (RLC) layer, medium access control (MAC) layer, higher physical layer (Higher PHY) layer, and other functions. In some examples, a DU can control at least one RU. The DU connects to the RU through interfaces, which can be fronthaul interfaces. In some examples, the Higher PHY layer includes the physical (PHY) layer processing, such as forward error correction (FEC) encoding and decoding, scrambling, modulation, and demodulation.

[0089] In some examples, the RU is a logical node that carries both lower physical layer (PHY) and radio frequency (RF) processing. In some examples, the RU can be a 3GPP transmission reception point (TRP), a remote radio head (RRH), or other similar entities. In some examples, the Low-PHY includes PHY processing functions such as Fast Fourier Transform (FFT), Inverse Fast Fourier Transform (IFFT), digital beamforming, and filtering. The RU communicates with one or more terminals via a wireless link.

[0090] The DU and RU can be co-located or not. The DU and RU exchange control plane and user plane information via a fronthaul link through the Lower-Layer Split CUS-Plane (LLS-CUS) interface. LLS-CUS may include LLS-C and LLS-U interfaces providing the control plane (C-Plane) and user plane (U-Plane), respectively. In some examples, the control plane (C-Plane) refers to real-time control between the DU and RU. The DU and RU exchange management information via an LLS-M interface on the fronthaul link; the management plane (M-Plane) refers to non-real-time management operations between the DU and RU.

[0091] DU and RU can cooperate to implement the functions of the PHY layer. A DU can be connected to one or more RUs. The functions of DU and RU can be configured in various ways depending on the design. For example, a DU can be configured to implement baseband functions, and an RU can be configured to implement mid-RF functions. Another example is that a DU can be configured to implement higher-level functions in the PHY layer, and an RU can be configured to implement lower-level functions in the PHY layer, or to implement both lower-level and RF functions. Higher-level functions in the physical layer can include a portion of the physical layer's functions that are closer to the MAC layer, while lower-level functions in the physical layer can include another portion of the physical layer's functions that are closer to the mid-RF side.

[0092] A terminal is a device or module that connects to the aforementioned communication system and possesses corresponding communication functions. Terminals can also be referred to as terminal equipment, UE, user device, access terminal, user unit, user station, mobile station, mobile station (MS), remote station, remote terminal, mobile device, user terminal, terminal unit, terminal station, terminal device, wireless communication equipment, user agent, or user equipment, etc. A terminal typically contains communication modules, circuits, or chips that perform the corresponding communication functions. It may also be configured with program instructions for performing these functions. Terminals can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, and smart cities. The terminal can be a mobile phone, tablet computer, computer with wireless transceiver function, wearable device, vehicle, drone, helicopter, airplane, ship, robot, robotic arm, smart home device, transportation vehicle with wireless communication function, communication module, roadside unit (RSU) with terminal function, etc. The embodiments of this application do not limit the device form of the terminal.

[0093] In this application, "sending information" can be understood as one device sending information to another device, or it can also be understood as one logic module within a device sending information to another logic module. For example, "terminal sending information" can be understood as a terminal sending information to another device (such as another terminal), or it can be understood as logic module 1 in the terminal sending information to logic module 2 in the terminal.

[0094] In this application, "receiving information" can be understood as one device receiving information from another device, or it can also be understood as a logical module within a device receiving information from another logical module. For example, "terminal receiving information" can be understood as a terminal receiving information from another device (such as another terminal), or it can be understood as logical module 1 in the terminal receiving information from logical module 2 in the terminal.

[0095] The communication between different devices involved in this application can refer to direct communication between different devices (i.e., without the need for relaying or forwarding by other devices), or communication between different devices through other devices (i.e., requiring relaying or forwarding by other devices), or communication between a functional unit within a device and other devices through another functional unit. In other words, "sending information to… (e.g., a terminal)" or the relevant illustrations in the accompanying drawings can be understood as the destination of the information being the terminal. This can include sending information directly or indirectly to the terminal. "Receiving information from… (e.g., a terminal)" or "receiving information from… (e.g., a terminal)" or "receiving information sent (e.g., by a terminal)" or the relevant illustrations in the accompanying drawings can be understood as the source of the information being the terminal. This can include receiving information directly or indirectly from the terminal. Information may undergo necessary processing between the source and destination, such as format changes, analog-to-digital conversion, amplification, filtering, etc., but the destination can understand the valid information from the source. Similar expressions in this application can be understood in a similar way, and will not be elaborated further here.

[0096] To facilitate understanding of the embodiments of this application, some knowledge / terms used in the solutions of this application are introduced below. It should be noted that these explanations are for the purpose of making the embodiments of this application easier to understand, and should not be regarded as limiting the scope of protection claimed by this application.

[0097] 1. Internet Protocol Multimedia Subsystem (IMS)

[0098] IMS is a standardized network architecture based on the Internet Protocol (IP). It is a new form of multimedia service that can meet users' more diverse multimedia service needs. IMS uses the Session Initiation Protocol (SIP) for end-to-end call control. By maximizing the reuse of Internet technologies and protocols, inheriting the network technologies unique to cellular mobile communication systems, and fully drawing on softswitch network technologies, IMS can provide carrier-grade quality of service (QoS), provide effective and flexible billing, and has a powerful ability to integrate various network services. Meanwhile, IMS draws on softswitch network technology and adopts a gateway-based interoperability scheme, including network elements such as signaling gateway (SG), media gateway control function (MGCF), and media gateway controller (MGC). Moreover, the MGCF and MGC also use the H.248 protocol jointly developed by the Internet Engineering Task Force (IEIF) and the International Telecommunication Union Telecommunication Standardization Sector (ITU-T). This allows IMS terminals to be mobile terminals, fixed-line telephone terminals, multimedia terminals, and personal computers (PCs). The access method is not limited to cellular radio frequency interfaces; it can be wireless (WLAN), wired local area networks (LAN), digital subscriber line (DSL), and other technologies.

[0099] Generally, an IMS network can include:

[0100] (1) The Home Subscriber Server (HSS) is a core user database. It provides support for the entity that actually manages calls in the IMS network. The HSS stores user and service-related data in the IMS network, including user identity, authentication data, service data, access parameters, service triggering information, and roaming information.

[0101] (2) Call Session Control Function (CSCF): As the core of IMS, the CSCF is responsible for processing user multimedia sessions. Based on its function, it can be further divided into: proxy call control function (P-CSCF), interrogation call control function (I-CSCF), and serving call control function (S-CSCF).

[0102] (3) P-CSCF: It is the interface network element between the IMS core network and the user terminal. It is responsible for user authentication, security mechanism negotiation, encryption protection, signaling compression and other functions related to the access network. When working with the access terminal with PDF function module, it can also complete the resource reservation function; and work with the I-CSCF / S-CSCF side to complete the call connection processing.

[0103] (4) I-CSCF: It is the entry point of the IMS home network. It selects the appropriate S-CSCF for incoming calls from the P-CSCF in the home network and provides access to the external IMS network of the visited network.

[0104] (5) S-CSCF: It plays a core role in IMS network session control and is responsible for terminal registration and authentication, session control, user service information management, and triggering specified services to the application server (AS).

[0105] (6)AS: Provides various service processing, such as public telephone exchange simulation service, centralized user digital exchange service, etc.

[0106] (7) Media Resource Function Controller (MRFC): Parses resource control commands from S-CSCF and AS, and controls MRFP to provide media resources, such as three-way conference mixing and announcement audio.

[0107] (8) Media Resource Function Processor (MRFP): Under the control of MRFC, it provides media resources to the terminal.

[0108] 2. Registration process and call setup process

[0109] In a communication system, registration is the process by which a terminal declares its availability to the network and obtains service permissions; it is a prerequisite for communication. Call establishment, on the other hand, is the process of establishing a real-time media session between the calling and called parties. During registration, the terminal sends a registration request message to the network, which may contain information such as the user's identity and IP address. Upon receiving the registration request message, the network verifies the user's identity and sends a registration response message to the terminal so that subsequent call requests can locate the user. In other words, registration is a prerequisite for calling; unregistered users cannot initiate or receive calls.

[0110] The call setup process is described below. The 3GPP standard defines the call setup process, through which a call can be established between the calling and called parties to conduct voice calls. For example, as shown in Figure 4, it mainly includes several processes such as call initiation, media negotiation, voice carrier establishment, temporary message confirmation, resource reservation confirmation, ringing, and call connection. The calling party includes the calling UE, RAN, CN, and IMS. Similarly, the called party includes the called UE, RAN, CN, and IMS. Specifically:

[0111] Step 1: The calling UE sends an invitation (INVITE) message to the called party through the IMS network to initiate a call.

[0112] Step 2: The IMS network sends back a temporary response message (e.g., 100 Trying), indicating that the request has been received and is being processed.

[0113] Step 3: The called party sequentially sends 183 Session Progress feedback to the calling UE through the IMS network and CN to indicate that the call is being processed.

[0114] Step 3a: The IMS network triggers the 5G core network (5GC) to establish a dedicated voice bearer.

[0115] Step 4: The calling UE sends a temporary message acknowledgment (PRACK) to the called party via the IMS network.

[0116] Step 5: The called party sends a 200 OK message to the calling UE via the IMS network, indicating that the temporary message should be reconfirmed.

[0117] Step 6: The calling UE sends an UPDATE to the called side through the IMS network, indicating that the calling resource reservation was successful.

[0118] Step 7: The called party sends a 200 OK to the calling UE via the IMS network, indicating that the called party's resource reservation was successful.

[0119] Step 8: The called party sends a 180 Ringing response to the calling UE through the IMS network, indicating that the called party is ringing.

[0120] Step 9: The called party sends a 200 OK to the calling UE via the IMS network, instructing the called party to accept the call.

[0121] Step 10: The calling UE sends an acknowledgment (ACK) to the called party via the IMS network, instructing the calling UE to acknowledge the call establishment.

[0122] Specifically, the interaction between the UE and the IMS network in each of the above steps can be the interaction between the UE and the P-CSCF in the IMS network. These interactions all use the SIP message format, such as INVITE, 100Trying, and 183Session Progress.

[0123] 3. Signaling compression (sigcomp)

[0124] SIGCOMP is a key technology for optimizing signaling transmission. Through compression algorithms and state management, it significantly reduces signaling overhead and is widely used in IMS, VoLTE, and IoT scenarios. SIGCOMP is a protocol for compressing signaling data, designed to reduce the transmission overhead of signaling messages, especially improving efficiency in bandwidth-constrained networks (such as wireless networks).

[0125] Taking the call setup process described above as an example, the call control messages involved in the call setup process (such as INVITE, 100Trying, 183Session Progress, etc.) are all SIP messages (or SIP format messages, or SIP protocol-based transmission messages). Generally speaking, SIP messages are usually quite long, or the SIP message payload is usually large. Therefore, to reduce the size of SIP messages, they can be compressed. For example, a commonly used compression method is sigcomp. It should be noted that this application does not limit the use of other compression methods; for ease of understanding, the following description mainly uses sigcomp as an illustrative example.

[0126] In one possible implementation, when using sigcomp, "comp=sigcomp" can be carried in every SIP message during the call setup process to indicate / enable compression. For example, "comp=sigcomp" can be carried in the routing parameters (routing parameters can be, for example, Via header field, Contact header field, Route header field, or Record-Route header field) of the aforementioned SIP messages such as INVITE, 100Trying, and 183Session Progress to indicate compression.

[0127] 4. Narrowband high-orbit satellites

[0128] Narrowband high-orbit satellites refer to satellites operating in geostationary earth orbit (GEO) that primarily provide narrowband communication services. With the development of communication technology, using narrowband high-orbit satellites for voice services has become an industry trend. However, narrowband high-orbit satellites suffer from low transmission rates and high latency. Especially when applied to voice services, continuing to include "comp=sigcomp" in every SIP message (e.g., INVITE, 100Trying, 183Session Progress, etc.) to indicate / enable compression further increases the transmission overhead of the satellite network over the air interface during the call setup process, thus increasing call latency.

[0129] Based on this, this application proposes a communication method and apparatus. By performing a compression function enable / negotiation during the IMS registration process, the SIP messages sent between the terminal and the P-CSCF in the subsequent call setup process no longer carry comp=sigcomp. Instead, the message compression operation is performed by default or the compression operation is determined based on the terminal's access method. Therefore, the size of messages / signaling in the call process / call setup process can be reduced, thereby saving transmission overhead and reducing call latency.

[0130] It should be noted that in the description of this application, "including" can also be replaced by "instruction" or "configuration," etc. "Instruction" can include direct and indirect instructions, as well as explicit and implicit instructions. The information indicated by a certain piece of information (such as the first information, second information, etc. below) is called the information to be instructed. In the specific implementation process, there are many ways to indicate the information to be instructed. For example, the information to be instructed can be directly indicated, including the information itself or its index. Alternatively, the information to be instructed can be indirectly indicated by indicating other information, where there is a relationship between the other information and the information to be indicated. Another example is that only a part of the information to be indicated can be indicated, while the other parts are known, pre-agreed, or deducible. Furthermore, the instruction of specific information can be achieved by using a pre-agreed (e.g., protocol-defined) arrangement of various pieces of information, thereby reducing the instruction overhead to some extent.

[0131] In this application, the descriptions of "message" and "signaling" can be used interchangeably; for example, the first message can also be called the first signaling. The naming of messages or fields described below is merely illustrative or based on the current protocol, and this application does not limit subsequent messages or fields with the same function to other naming methods.

[0132] The communication method and apparatus provided in this application will be further described below with reference to the accompanying drawings. It is understood that this application uses a first network element and a terminal as examples to illustrate the execution of the interaction, but this application does not limit the execution subject of the interaction. For example, the method executed by the first network element in this application can also be implemented by a module (e.g., a circuit, chip, or chip system) in the first network element, or by a logical node, logical module, or software capable of implementing all or part of the functions of the first network element; the method executed by the terminal in this application can also be implemented by a communication / processing module in the terminal, or by a circuit or chip (such as a modem chip (also known as a baseband chip), or a SoC chip / SIP chip containing a modem core, or a GPU / AI processor / ASIC) in the terminal responsible for communication / processing functions.

[0133] Please refer to Figure 5, which is a flowchart illustrating a communication method provided in an embodiment of this application. As shown in Figure 5, the communication method may include the following steps:

[0134] S501, the terminal sends a registration request message to the first network element in the IMS network. Correspondingly, the first network element receives the registration request message from the terminal.

[0135] The aforementioned first network element can be, for example, a P-CSCF, or it can be any other network element with P-CSCF functionality. This application does not limit the name of the first network element. The aforementioned registration request message includes first information, which is used to indicate that the terminal supports the compression processing capability of the first message, or, the first information is used to indicate that the terminal requests to perform a compression operation on the first message, or, the first information is used to indicate that the terminal supports the compression processing capability of the first message and requests to perform a compression operation on the first message. Generally, the terminal can send / report a registration request message including the first information to the first network element in the IMS network if it determines that it supports the compression processing capability of the first message. Alternatively, the terminal can send a registration request message including the first information to the first network element in the IMS network if its access method is via high-orbit satellite or narrowband high-orbit satellite. This is because when the terminal's access method is via high-orbit satellite or narrowband high-orbit satellite, the transmission rate is lower and the call latency is greater. Therefore, it is more necessary to negotiate the compression processing capability and / or the compression enable capability during the registration process to reduce the transmission overhead in the subsequent call establishment process, thereby reducing the call latency.

[0136] For example, the aforementioned first information may be specifically carried in the Contact field of the registration request message, and this application does not limit this. It is understood that the terminals involved in this application communicate via non-terrestrial networks, where the terminal may be the calling UE or the called UE; the following description primarily uses the terminal as the calling UE as an example. The aforementioned non-terrestrial network may also be called an NTN. Optionally, the non-terrestrial network may be an independent NTN, or a converged network of NTN and TN, such as a satellite-terrestrial converged network, etc., and is not limited thereto.

[0137] The aforementioned first message refers to the message transmitted between the terminal and the first network element. For example, this message can be an uplink message, i.e., a message sent by the terminal, or it can be a downlink message, such as a message received by the terminal. Generally, in a calling scenario, for the calling UE, the message sent by the calling UE to the calling IMS, or to the called UE, is an uplink message; the message received by the calling UE from the calling IMS, or from the called UE (or a message sent by the called UE to the calling UE), is a downlink message. In a called scenario, for the called UE, the message sent by the called UE to the called IMS, or to the calling UE, is an uplink message; the message received by the called UE from the called IMS, or from the calling UE (or a message sent by the calling UE to the called UE), is a downlink message. The following text primarily uses the calling scenario as an example for illustrative purposes. In the calling scenario, the calling UE can decide for itself whether to perform compression operation / processing on the uplink message, while whether the downlink message needs to be compressed / processed is decided and executed by the first network element in the IMS network. In other words, if the downlink message needs to be compressed, the first network element (e.g., P-CSCF) can compress the message received from the called side before sending it to the called UE.

[0138] Understandably, the first message in this application can be interpreted as a call-related message or a message in the call setup process. For example, the first message can be a call setup message / signaling, i.e., a message / signaling used to establish a call between the calling UE and the called UE, or it can also be called a voice call control message, or a call control / setup message for voice services, or a call control message, call control signaling, etc. For example, the first message can be, for example, INVITE, 100Trying, 183Session Progress, etc., as shown in Figure 4, and will not be listed one by one here. It should be understood that the terms "message" and "signaling" in this application can be used interchangeably.

[0139] When the compression processing / operation involved in this application is specifically signaling compression (sigcomp), the aforementioned first information can be +g.3gpp.sigcomp. Optionally, the compression processing involved in this application may also be other compression mechanisms / methods, such as simplifying existing SIP message content to generate simplified signaling, such as SimplifiedSIP. In this case, the first information can be, for example, +g.3gpp.SimplifiedSIP. This application does not limit the specific method of compression processing or the naming of the first information.

[0140] S502, the first network element sends a registration response message to the terminal. Correspondingly, the terminal receives the registration response message from the first network element.

[0141] The registration response message includes second information, which is used to instruct the first network element to support the compression processing capability of the first message, or, the second information is used to instruct the first network element to accept activation to perform compression operation on the first message (or, in short, the second information is used to instruct the first network element to perform compression operation on the first message), or, the second information is used to instruct the first network element to support the compression processing capability of the first message and accept activation to perform compression operation on the first message.

[0142] Optionally, the term "activation" described in the embodiments of this application can also be replaced by "enable," "start," or "trigger," etc., without limitation. Similarly, the term "acceptance" described in the embodiments of this application can also be replaced by "agree," "permit," etc., without limitation. For example, the second information used to instruct the first network element to accept activation and perform compression operation on the first message can also be replaced by "the second information used to instruct the first network element to accept / agree / agree to activation and perform compression operation on the first message," etc., without limitation.

[0143] For example, the aforementioned registration response message can specifically be a 200 OK message, and the aforementioned second information can be carried in the Feature Caps field of the 200 OK message. Optionally, the second information can be explicitly carried in the registration response message, or it can be not explicitly carried in the registration response message. For example, after configuring the registration response message, it is assumed that the first network element supports the compression processing capability of the first message and / or agrees to perform compression operations on the first message. In this case, it can be understood that the second information always enables the registration response message to instruct the first network element to support the compression processing capability of the first message and / or agree to perform compression operations on the first message. Therefore, the registration response message information may not contain the second information.

[0144] In one possible implementation, after the terminal and the first network element exchange registration request and registration response messages (or after the registration process between the terminal and the first network element is completed), the terminal can send a first uplink message. Unlike existing SIP messages that carry information indicating compression for the next SIP message, this first uplink message does not include / does not carry / does not carry information about compression for the first downlink message. It should be understood that the first uplink message itself can be a compressed message from the terminal; for example, the first uplink message can be a message compressed using sigcomp. Both the first uplink message and the first downlink message are considered first messages. For example, the first downlink message can be a response message to the first uplink message, or it can be another message transmitted after the first uplink message that is unrelated to it.

[0145] Optionally, the exclusion of information for compressing the first downlink message in the first uplink message can be understood as the routing parameters of the first uplink message not including information for compressing the first downlink message. For example, the Via header field, Contact header field, Route header field, or Record-Route header field of the first uplink message do not include information for compressing the first downlink message. The information for compressing the first downlink message could be, for example, comp = sigcomp, etc., and this application does not limit this.

[0146] In one possible implementation, after the terminal and the first network element exchange registration request and registration response messages, the terminal can also receive a second downlink message. This second downlink message does not include information on compressing the second uplink message, and the second downlink message and the second uplink message are part of the first message. For example, the second uplink message can be a response message to the second downlink message, or it can be another message transmitted after the second downlink message that is unrelated to the second uplink message. For example, in a calling scenario, for the calling UE, the second downlink message can be a message sent by the called UE to the calling UE. The first network element (e.g., P-CSCF) compresses the message received from the called side before sending it to the calling UE. As another example, in a called scenario, for the called UE, the second downlink message can be a message sent by the calling UE to the called UE. The first network element (e.g., P-CSCF) compresses the message received from the calling side before sending it to the called UE.

[0147] It should be understood that the first downlink message and the second downlink message mentioned above may be the same message or they may be different messages. For example, when the first downlink message and the second downlink message are the same message, the second downlink message can be understood as a response message transmitted after the first uplink message and in response to the first uplink message. For a specific example, if the second downlink message and the first downlink message are the same, the first uplink message could be invite (e.g., step 1 in Figure 4), the first downlink message / second downlink message could be 183Session Progress (e.g., step 3 in Figure 4), and the second uplink message could be PRACK (e.g., step 4 in Figure 4). For another specific example, if the second downlink message and the first downlink message are different, the first uplink message could be invite (e.g., step 1 in Figure 4), the first downlink message could be 183Session Progress (e.g., step 3 in Figure 4), the second downlink message could be 200 OK (e.g., step 9 in Figure 4), and the second uplink message could be ACK (e.g., step 10 in Figure 4).

[0148] It is easy to understand that, as described above, the compression operation of downlink messages (such as the first downlink message or the second downlink message) is performed at the first network element; in other words, the compression processing of downlink messages is implemented by the first network element. Optionally, whether uplink messages undergo compression processing is implemented by the terminal.

[0149] Generally, after negotiating compression processing capabilities and / or enabling compression operations in the aforementioned registration process, the first network element can, by default, perform compression operations / processing on downlink messages involved in subsequent call setup procedures or other procedures. Alternatively, the first network element can first make a judgment and then determine whether to perform compression operations on downlink messages in subsequent procedures. For example, when activating / enabling compression operations on the first message, the first network element can, by default, perform compression operations / processing on downlink messages involved in subsequent call setup procedures or other procedures. As another example, when the first information is used to indicate that the terminal supports the compression processing capability of the first message (or when negotiating compression processing capabilities), the first network element can first make a judgment and then determine whether to perform compression operations on downlink messages in subsequent procedures.

[0150] The so-called "first network element judgment" can specifically refer to determining whether to perform compression operations on downlink messages based on the terminal's access method, and / or, whether the first network element can determine whether to perform compression operations on downlink messages based on whether the uplink messages sent by the terminal are in compressed format (or described as the first network element determining whether to perform compression operations on downlink messages based on whether the uplink messages sent by the terminal are compressed). Specifically, if the first network element determines whether to perform compression operations on downlink messages based on the terminal's access method, then if the terminal's access method is via high-orbit satellite or narrowband high-orbit satellite, compression operations will be performed on the first downlink message; otherwise, if the terminal's access method is not via high-orbit satellite or narrowband high-orbit satellite, compression operations will not be performed on the first downlink message.

[0151] Regarding the method of obtaining the terminal's access method, one possible approach is that the first network element can determine the terminal's access method by the information included in the uplink message received from the terminal (e.g., an invite message sent by the terminal to the first network element). For example, it can determine whether the terminal accesses the network via narrowband high-orbit satellite by using access network information (e.g., P-Access-Network-Info) included in the invite message. Another possible approach is that the first network element can send a first request message to a core network element (e.g., a policy control function (PCF) or a policy and charging rules function (PCRF)) to request the terminal's access method. Correspondingly, the core network element receives the first request message and, in response, sends a first response message to the first network element, which includes the terminal's access method.

[0152] If the first network element determines whether to perform compression on downlink messages based on whether the uplink message sent by the terminal is in compressed format, then if the uplink message sent by the terminal is in compressed format (or described as if the uplink message sent by the terminal has undergone compression), it determines to perform compression on the first downlink message; if the uplink message sent by the terminal is not in compressed format (or described as if the uplink message sent by the terminal has not undergone compression), it determines not to perform compression on the first downlink message. Optionally, in the call setup process or other processes, if the first message is a downlink message instead of an uplink message, the first network element may not perform compression on the first message (i.e., the downlink message) initially, and perform compression on subsequent downlink messages only after receiving compressed uplink messages.

[0153] The following figures 6A to 6C illustrate several scenarios for compressing downlink messages in this application.

[0154] For example, as shown in Figure 6A, after negotiation to enable / activate compression operations in the registration process, the first network element performs compression operations on downlink messages in subsequent call setup or other processes by default. As shown in Figure 6A, when the first information included in the registration request message sent by the terminal to the first network element indicates that the terminal requests to perform a compression operation on the first message (i.e., step a1), and the second information included in the registration response message returned by the first network element indicates that the first network element agrees to perform a compression operation on the first message or is described as the second information instructing the first network element to accept activation to perform a compression operation on the first message (i.e., step a2), the terminal can send a first uplink message to the first network element (i.e., step a3). This first uplink message does not include information on performing compression processing on the first downlink message (e.g., the first uplink message does not include comp = sigcomp), and this first uplink message is a compressed message (e.g., the first uplink message is a message processed by sigcomp). After the first network element receives the first uplink message, the first network element can send a first downlink message to the terminal (i.e., step a4). This first downlink message does not include information on performing compression processing on the second uplink message (e.g., the first downlink message does not include comp = sigcomp), and this first downlink message is a compressed message (e.g., the first downlink message is a message processed by sigcomp).

[0155] As another example, Figure 6B illustrates the situation where, after negotiating compression capabilities during the registration process, the first network element determines whether to perform compression operations on downlink messages based on the terminal's access method. As shown in Figure 6B, when the first information included in the registration request message sent by the terminal to the first network element indicates that the terminal supports the compression capability of the first message (i.e., step b1), and the second information included in the registration response message returned by the first network element indicates that the first network element supports the compression capability of the first message (i.e., step b2), the terminal can send a first uplink message to the first network element (i.e., step b3). This first uplink message includes the terminal's access method (e.g., P-Access-Network-Info). Therefore, after receiving the first uplink message, the first network element can determine whether to perform compression processing on the downlink messages based on the terminal's access method (i.e., step b4). Specifically, if the terminal accesses the network via a narrowband high-orbit satellite, the first downlink message sent by the first network element to the terminal does not include information on compressing the second uplink message (e.g., the first downlink message does not include comp = sigcomp), and the first downlink message is a compressed message (e.g., the first downlink message is a message that has undergone sigcomp processing, i.e., step b5).

[0156] As another example, Figure 6C illustrates the situation where, after negotiating compression capabilities during the registration process, the first network element determines whether to perform compression operations on the downlink message based on whether the uplink message sent by the terminal is in compressed format. As shown in Figure 6C, when the first information included in the registration request message sent by the terminal to the first network element indicates that the terminal supports the compression capability of the first message (i.e., step c1), and the second information included in the registration response message returned by the first network element indicates that the first network element supports the compression capability of the first message (i.e., step c2), the terminal can send a first uplink message to the first network element (i.e., step c3). This first uplink message does not include information on performing compression processing on the first downlink message (e.g., the first uplink message does not include comp = sigcomp), and the first uplink message is a compressed message (e.g., the first uplink message executes sigcom). The message processed by p. After the first network element receives the first uplink message, the first network element can determine whether to compress the downlink message based on whether compression is performed on the uplink message (i.e., step c4). As shown in Figure 6C, since the first network element determines that the first uplink message is a compressed message, the first network element can send a compressed first downlink message to the terminal. This first downlink message does not include information on performing compression on the second uplink message (e.g., the first downlink message does not include comp = sigcomp), and this first downlink message is a compressed message (e.g., the first downlink message is a message that has undergone sigcomp processing, i.e., step c5).

[0157] Optionally, the above different situations can be implemented individually or in combination. For example, when the first network element determines whether to perform compression processing on the downlink message, it can specifically send a message to the terminal that does not include comp=sigcomp and performs sigcomp processing when the terminal's access method is to access the network via narrowband high-orbit satellite and the first uplink message is a compressed message.

[0158] In this embodiment, after the terminal and the first network element (e.g., P-CSCF) in the IMS network perform a negotiation on compression processing capability and / or a negotiation on compression enable during the registration process, the SIP messages sent between the terminal and the P-CSCF in the subsequent call setup process no longer carry comp=sigcomp. Instead, the message compression operation is performed by default or the compression operation is determined based on the terminal's access method. This can reduce the size of SIP messages transmitted over the air interface under the satellite network and shorten the call latency.

[0159] The communication device provided in this application will now be described in detail with reference to Figures 7 to 9.

[0160] It is understood that, in order to achieve the functions in the above embodiments, the communication device includes hardware structures and / or software modules corresponding to each function. Those skilled in the art should readily recognize that, based on the units and method steps described in conjunction with the embodiments disclosed in this application, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by hardware or by computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0161] Figures 7 to 9 are schematic diagrams illustrating possible communication devices provided in embodiments of this application. These communication devices can be used to implement the functions of the terminal or the first network element in the above method embodiments, and thus can also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the communication device can be the UE shown in Figure 1, or it can be the P-CSCF in the IMS network shown in Figure 1. Optionally, it can also be a module (such as a chip) applied to the terminal or the first network element.

[0162] As shown in Figure 7, the communication device 700 includes a processing unit 710 and a transceiver unit 720. The transceiver unit 720 and the processing unit 710 can be software, hardware, or a combination of both. Optionally, the communication device 700 may further include a storage unit 730 for storing device program code and / or data, not shown in Figure 7.

[0163] The transceiver unit 720 can implement sending and / or receiving functions. Optionally, the transceiver unit 720 can also be referred to as a communication unit. The transceiver unit 720 may further include a receiving unit and / or a sending unit, wherein the receiving unit is used to implement the receiving function, and the sending unit is used to implement the sending function. Optionally, the transceiver unit 720 can be used to receive information sent by other devices, and can also be used to send information to other devices.

[0164] The communication device 700 is used to implement the functions of the terminal-side communication device in the method embodiment shown in FIG5 above. For example, the terminal-side communication device may be a terminal or a communication module in the terminal, or a circuit or chip in the terminal responsible for communication functions. Alternatively, the communication device 700 may be used to implement the functions of the network-side communication device in the method embodiment shown in FIG5 above. For example, the network-side communication device may be a first network element, a module in the first network element (e.g., a circuit, a chip, or a chip system), or a logic node, logic module, or software that can implement all or part of the functions of the first network element.

[0165] When the communication device 700 is used to implement the functions of the terminal in the method embodiment shown in FIG5:

[0166] The transceiver unit 720 is configured to send a registration request message to a first network element in the IMS network. The registration request message includes first information, which indicates that the terminal supports the compression processing capability of a first message, and / or, the first information indicates that the terminal requests to perform a compression operation on the first message. The terminal communicates through a non-terrestrial network, and the first message is a message transmitted between the terminal and the first network element. The transceiver unit 720 is also configured to receive a registration response message from the first network element. The registration response message includes second information, which indicates that the first network element supports the compression processing capability of the first message, and / or, the second information indicates that the first network element performs a compression operation on the first message.

[0167] In one possible implementation, the transceiver unit 720 is further configured to: send a first uplink message, wherein the first uplink message does not include information on performing compression processing on a first downlink message, and the first uplink message and the first downlink message belong to the first message.

[0168] In one possible implementation, the first uplink message does not include information on performing compression processing on the first downlink message, including: the Via header field, Contact header field, Route header field, or Record-Route header field of the first uplink message do not include information on performing compression processing on the first downlink message.

[0169] In one possible implementation, the first uplink message further includes the terminal's access method; when the first information is used to indicate that the terminal supports the compression processing capability of the first message, the terminal's access method is used to determine whether to perform a compression operation on the first downlink message.

[0170] In one possible implementation, the transceiver unit 720 is further configured to: receive a second downlink message, the second downlink message not including information on performing compression processing on a second uplink message, the second downlink message and the second uplink message belonging to the first message.

[0171] In one possible implementation, sending the registration request message to the first network element in the IMS network includes: when the terminal's access method is via high-orbit satellite or narrowband high-orbit satellite access, sending the registration request message to the first network element in the IMS network.

[0172] In one possible implementation, the registration response message is a 200 OK message, and the second information is carried in the Feature Caps field of the 200 OK message.

[0173] In one possible implementation, the first information is carried in the Contact field of the registration request message.

[0174] In one possible design, when the communication device 700 is a terminal or a communication module within a terminal, the functionality of the processing unit 710 can be implemented by one or more processors. Specifically, the processor may include a modem chip, or a system-on-a-chip (SoC) or SIP chip containing a modem core. The functionality of the transceiver unit 720 can be implemented by transceiver circuitry.

[0175] In one possible design, when the communication device 700 is a circuit or chip in a terminal responsible for communication functions, such as a modem chip or a system-on-a-chip (SoC) or SIP chip containing a modem core, the function of the processing unit 710 can be implemented by a circuit system in the aforementioned chip that includes one or more processors or processor cores. The function of the transceiver unit 720 can be implemented by the interface circuitry or data transceiver circuitry on the aforementioned chip.

[0176] When the communication device 700 is used to implement the function of the first network element in the method embodiment shown in FIG5:

[0177] The transceiver unit 720 is configured to receive a registration request message from a terminal, the registration request message including first information, the first information being used to indicate that the terminal supports the compression processing capability of a first message, and / or, the first information being used to indicate that the terminal requests to perform a compression operation on the first message, the terminal communicating via a non-terrestrial network, and the first message being a message transmitted between the terminal and the first network element; the transceiver unit 720 is configured to send a registration response message to the terminal, the registration response message including second information, the second information being used to indicate that the first network element supports the compression processing capability of the first message, and / or, the second information being used to indicate that the first network element performs a compression operation on the first message.

[0178] In one possible implementation, after receiving the registration response message from the first network element, the transceiver unit 720 is further configured to: receive a first uplink message, wherein the first uplink message does not include information on performing compression processing on the first downlink message, and the first uplink message and the first downlink message belong to the first message.

[0179] In one possible implementation, the first uplink message does not include information on performing compression processing on the first downlink message, including: the Via header field, Contact header field, Route header field, or Record-Route header field of the first uplink message does not include information on performing compression processing on the first downlink message.

[0180] In one possible implementation, the first uplink message further includes the terminal's access method; the processing unit 710 is configured to: determine whether to perform a compression operation on the first downlink message based on the terminal's access method.

[0181] In one possible implementation, the transceiver unit 720 is configured to send a first request message to a core network element, the first request message being used to request the terminal's access method; the transceiver unit 720 is configured to receive a first response message from the core network element, the first response message including the terminal's access method; and the processing unit 710 is configured to determine whether to perform a compression operation on the first downlink message based on the terminal's access method.

[0182] In one possible implementation, when determining whether to perform compression operation on the first downlink message based on the terminal's access method, the processing unit 710 is specifically used to: determine to perform compression operation on the first downlink message when the terminal's access method is via high-orbit satellite or narrowband high-orbit satellite.

[0183] In one possible implementation, the transceiver unit 720 is further configured to: send a second downlink message, the second downlink message not including information on performing compression processing on the second uplink message, the second downlink message and the second uplink message belonging to the first message.

[0184] In one possible implementation, the registration response message is a 200 OK message, and the second information is carried in the Feature Caps field of the 200 OK message.

[0185] In one possible implementation, the first information is carried in the Contact field of the registration request message.

[0186] For a more detailed description of the processing unit 710 and the transceiver unit 720 described above, please refer to the relevant description in the method embodiment shown in FIG5.

[0187] It is understood that the division of units in the above-described device is merely a logical functional division. Each function can correspond to a functional unit, or two or more functions can be integrated into one functional unit. In actual implementation, all or some units can be integrated into a single physical entity, or they can be distributed across different physical entities. Furthermore, the aforementioned functional units can be implemented in hardware, software, or a combination of both. Whether a function is executed 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.

[0188] In one example, the functional unit in any of the above devices may be one or more integrated circuits configured to implement the above methods, such as: one or more ASICs, or one or more central processing units (CPUs), one or more microcontroller units (MCUs), one or more digital signal processors (DSPs), or one or more field programmable gate arrays (FPGAs), or a combination of at least two of these integrated circuit forms.

[0189] In one example, storage unit 730 may include random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory and / or registers, etc.

[0190] As shown in Figure 8, the communication device 800 includes a processor 810, and optionally, an interface circuit 820. The processor 810 and the interface circuit 820 are coupled to each other. It is understood that the interface circuit 820 can be a transceiver or an input / output interface. Optionally, the communication device 800 may also include a memory 830 for storing computer programs or instructions executed by the processor 810, or storing input data required by the processor 810 to execute instructions, or storing data generated by the processor 810 after executing computer programs or instructions.

[0191] When the communication device 800 is used to implement the method shown in FIG5, the processor 810 is used to implement the function of the processing unit 710, and the interface circuit 820 is used to implement the function of the transceiver unit 720.

[0192] When the aforementioned communication device is a chip applied to a terminal, the terminal chip implements the functions of the terminal in the above method embodiments. The terminal chip receives information sent to the terminal by the first network element through other modules (such as an RF module or antenna) in the terminal; or, the terminal chip sends information to other modules (such as an RF module or antenna) in the terminal, which is information sent by the terminal to the first network element.

[0193] When the aforementioned communication device is a module applied to the first network element, the first network element module implements the functions of the first network element in the above method embodiments. The first network element module receives information from other modules (such as radio frequency modules or antennas) in the first network element, and this information is sent by the terminal to the first network element; or, the first network element module sends information to other modules (such as radio frequency modules or antennas) in the first network element, and this information is sent by the first network element to the terminal.

[0194] As shown in Figure 9, the communication device 900 includes a processor 910, a memory 920, and a transceiver 930. The processor 910 is mainly used for processing communication protocols and communication data; controlling the terminal / first network element; executing software programs; and processing data from the software programs. The memory 920 can store computer program code, software programs, and data. The transceiver 930 includes a transmitter 931, a receiver 932, radio frequency circuitry (not shown in the figure), and an antenna 933.

[0195] The processor 910 can also be called a processing unit, processing board, processing module, or processing device. The transceiver 930 can also be called a transceiver unit, transceiver, or transceiver device.

[0196] Optionally, the devices in transceiver 930 used to implement the receiving function can be considered as receiving modules, and the devices in transceiver 930 used to implement the transmitting function can be considered as transmitting modules. That is, transceiver 930 includes a receiver and / or a transmitter. A transceiver may also be called a transceiver unit, transceiver module, or transceiver circuit, etc. A receiver may also be called a receiver unit, receiving module, or receiving circuit, etc. A transmitter may also be called a transmitter, transmitting module, or transmitting circuit, etc.

[0197] Processor 910 is used to execute terminal-side processing operations in the embodiment shown in FIG. 5. Transceiver 930 is used to execute terminal-side transmission and reception operations in the embodiment shown in FIG. 5. Alternatively, processor 910 is used to execute network-side processing operations in the embodiment shown in FIG. 5. Transceiver 930 is used to execute network-side transmission and reception operations in the embodiment shown in FIG. 5.

[0198] When the communication device is a chip, the chip includes a processor and a transceiver. The transceiver can be an input / output circuit or a communication interface. The processor can be a processing module integrated on the chip, a microprocessor, or an integrated circuit. In the above method embodiments, the terminal's transmitting operation can be understood as the chip's output, and the terminal's receiving operation can be understood as the chip's input. Similarly, in the above method embodiments, the first network element's transmitting operation can be understood as the chip's output, and the first network element's receiving operation can be understood as the chip's input.

[0199] This application also provides a computer-readable storage medium storing a computer program or instructions for implementing the method executed by a terminal or a first network element in the above method embodiments.

[0200] For example, when the computer program is executed by the computer, it enables the computer to implement the method executed by the terminal or the first network element in the above method embodiments.

[0201] This application also provides a computer program product containing a program or instructions, which, when executed by a computer, causes the computer to implement the method executed by the terminal or the first network element in the above method embodiments.

[0202] This application also provides a communication system, which includes a terminal and a first network element as described in the above embodiments. The terminal is used to perform some or all of the operations performed by the terminal in the above method embodiments, and the first network element is used to perform some or all of the operations performed by the first network element in the above method embodiments.

[0203] This application also provides a chip device, including a processor, for calling a computer program or computer instructions stored in the memory, so that the processor executes the method provided in the embodiment shown in FIG5 above.

[0204] In one possible implementation, the input of the chip device corresponds to the receiving operation in any of the embodiments shown in FIG5 above, and the output of the chip device corresponds to the sending operation in any of the embodiments shown in FIG5 above.

[0205] Optionally, the processor is coupled to the memory via an interface.

[0206] Optionally, the chip device further includes a memory storing computer programs or computer instructions.

[0207] It is understood that the processor in the embodiments of this application can be a CPU, or other general-purpose processors, DSPs, ASICs, FPGAs, or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

[0208] The method steps in the embodiments of this application can be implemented in hardware or in software instructions executable by a processor. The software instructions can consist of corresponding software modules, which can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. The storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Alternatively, the ASIC can reside in a first network element or terminal. The processor and storage medium can also exist as discrete components in the first network element or terminal.

[0209] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are performed entirely or partially. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video optical disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both types of storage media.

[0210] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0211] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The order of the process numbers described above does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.

Claims

1. A communication method, characterized in that, The method is applied to a terminal or a chip in the terminal, including: A registration request message is sent to a first network element in the Internet Protocol Multimedia Subsystem (IMS) network. The registration request message includes first information, which is used to indicate that the terminal supports the compression processing capability of the first message, and / or the first information is used to indicate that the terminal requests to perform a compression operation on the first message. The terminal communicates through a non-terrestrial network, and the first message is a message transmitted between the terminal and the first network element. The system receives a registration response message from the first network element, the registration response message including second information, the second information being used to indicate that the first network element supports the compression processing capability of the first message, and / or, the second information being used to indicate that the first network element performs a compression operation on the first message.

2. The method according to claim 1, characterized in that, The method further includes: Send a first uplink message, which does not include information on performing compression processing on the first downlink message. The first uplink message and the first downlink message belong to the first message.

3. The method according to claim 2, characterized in that, The first uplink message does not include information on performing compression processing on the first downlink message, including: the Via header field, Contact header field, Route header field, or Record-Route header field of the first uplink message do not include information on performing compression processing on the first downlink message.

4. The method according to claim 2 or 3, characterized in that, The first uplink message also includes the terminal's access method; When the first information is used to indicate that the terminal supports the compression processing capability of the first message, the access method of the terminal is used to determine whether to perform a compression operation on the first downlink message.

5. The method according to any one of claims 1-4, characterized in that, The method further includes: Receive a second downlink message, which does not include information on performing compression processing on the second uplink message. The second downlink message and the second uplink message belong to the first message.

6. The method according to any one of claims 1-5, characterized in that, Sending a registration request message to the first network element in the IMS network includes: When the terminal accesses the network via high-orbit satellite or narrowband high-orbit satellite, it sends the registration request message to the first network element in the IMS network.

7. The method according to any one of claims 1-6, characterized in that, The registration response message is a 200 OK message, and the second information is carried in the Feature Caps field of the 200 OK message.

8. The method according to any one of claims 1-7, characterized in that, The first information is carried in the Contact field of the registration request message.

9. A communication method, characterized in that, The method is applied to the first network element in an Internet Protocol Multimedia Subsystem (IMS) network, including: The terminal receives a registration request message, which includes first information indicating that the terminal supports the compression processing capability of the first message, and / or the first information indicating that the terminal requests to perform a compression operation on the first message. The terminal communicates through a non-terrestrial network, and the first message is a message transmitted between the terminal and the first network element. A registration response message is sent to the terminal. The registration response message includes second information, which is used to indicate that the first network element supports the compression processing capability of the first message, and / or, the second information is used to instruct the first network element to perform a compression operation on the first message.

10. The method according to claim 9, characterized in that, After receiving the registration response message from the first network element, the method further includes: A first uplink message is received, which does not include information on performing compression processing on a first downlink message. The first uplink message and the first downlink message belong to the first message.

11. The method according to claim 10, characterized in that, The first uplink message does not include information on performing compression processing on the first downlink message, including: the Via header field, Contact header field, Route header field, or Record-Route header field of the first uplink message do not include information on performing compression processing on the first downlink message.

12. The method according to claim 10 or 11, characterized in that, The first uplink message also includes the terminal's access method; The method further includes: Whether to perform compression operation on the first downlink message is determined based on the access method of the terminal.

13. The method according to claim 10 or 11, characterized in that, The method further includes: Send a first request message to the core network element, the first request message being used to request the terminal's access method; Receive a first response message from the core network element, wherein the first response message includes the access method of the terminal; Whether to perform compression operation on the first downlink message is determined based on the access method of the terminal.

14. The method according to claim 12 or 13, characterized in that, The step of determining whether to perform compression on the first downlink message based on the terminal's access method includes: If the terminal accesses the network via a high-orbit satellite or a narrowband high-orbit satellite, it is determined that a compression operation will be performed on the first downlink message.

15. The method according to any one of claims 9-14, characterized in that, The method further includes: Send a second downlink message, which does not include information on performing compression processing on the second uplink message. The second downlink message and the second uplink message belong to the first message.

16. The method according to any one of claims 9-15, characterized in that, The registration response message is a 200 OK message, and the second information is carried in the Feature Caps field of the 200 OK message.

17. The method according to any one of claims 9-16, characterized in that, The first information is carried in the Contact field of the registration request message.

18. A communication device, characterized in that, It includes units or modules for implementing the method as described in any one of claims 1-8, or includes units or modules for implementing the method as described in any one of claims 9-17.

19. A communication device, characterized in that, Includes a processor for executing computer programs or instructions to cause the communication device to implement the method as described in any one of claims 1-8, or to cause the communication device to implement the method as described in any one of claims 9-17.

20. A communication device, characterized in that, The device includes a processor and a transceiver, the transceiver being used to send and receive information, and the processor being used to execute a computer program or instructions to cause the communication device to implement the method as described in any one of claims 1-8, or to cause the communication device to implement the method as described in any one of claims 9-17.

21. A computer-readable storage medium, characterized in that, The storage medium stores a computer program or instructions, which, when executed by a communication device, implement the method as described in any one of claims 1-8, or the method as described in any one of claims 9-17.

22. A computer program product, characterized in that, Includes computer program code, which, when run on a computer, implements the method of any one of claims 1-8, or implements the method of any one of claims 9-17.

23. A communication system, characterized in that, The method includes a terminal and a first network element in an Internet Protocol Multimedia Subsystem (IMS) network, wherein the terminal is used to implement the method of any one of claims 1-8, and the first network element is used to implement the method of any one of claims 9-17.

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