A communication method and apparatus

Abstract

A communication method and device. In the method, a RAN sends a paging message to a target terminal device as a called user in a non-RRC connected state, and the paging message includes a SIP request message, without having to send the SIP request message to the target terminal device after the target terminal device resumes the RRC connected state. The target terminal device responds to the SIP request message in a network connection resuming process, and sends a SIP response message to the RAN / AMF through a message for resuming the network connection, without having to receive and respond to the SIP message after resuming the network connection, which helps to reduce the time delay for a calling user and a called user to establish a session, and improve user experience.

Description

Technical Field

[0001] This application relates to the field of wireless communication technology, and in particular to a communication method and apparatus. Background Technology

[0002] Common services offered by terminal devices include voice communication. Existing terrestrial communication networks, based on the IP Multimedia Subsystem (IMS), can provide users with voice, video, and information services. In satellite communication scenarios, radio access network (RAN) equipment or user plane function (UPF) elements can be deployed on satellites. However, due to the limited payload capacity of satellites, the IMS system may be located on the ground. The IMS system uses the SIP (Session Initiation Protocol) to create, modify, and terminate sessions between parties, thereby enabling multimedia services such as voice, video, images, and text.

[0003] However, if the called user is in an idle or inactive state, it needs to restore the network connection and enter a connected state before it can receive SIP messages, resulting in a significant delay. Summary of the Invention

[0004] This application provides a communication method and apparatus for reducing the latency of call establishment for terminal devices in non-radio resource control (RRC) connection states.

[0005] In a first aspect, embodiments of this application provide a communication method that can be applied to the wireless access network device side, such as the wireless access network device or the communication module in the wireless access network device, or the circuit or chip in the wireless access network device 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).

[0006] Taking the application of this method to a wireless access network device as an example, the method includes: sending a paging message, the paging message including a Session Initiation Protocol (SIP) request message for the target terminal device; receiving a connection message, the connection message being used by the target terminal device to restore network connection, and the connection message including a SIP response message.

[0007] In the above embodiments of this application, the RAN sends a paging message to the target terminal device, which is the called user and is in a non-RRC connected state. This paging message includes a SIP request message, eliminating the need to send the SIP request message to the target terminal device only after it has restored its RRC connected state. This helps reduce the latency of establishing a session between the calling user and the target terminal device. Furthermore, because the paging message contains a SIP request message, the target terminal device can respond to the SIP request message during network connection restoration and send a SIP response message to the RAN / AMF using a message for network connection restoration. This avoids having to receive and respond to the SIP message after network connection restoration, further reducing the latency of establishing a session between the calling user and the target terminal device and improving user experience.

[0008] In one possible implementation, the paging message includes a first part and a second part, the second part including the SIP request message; before sending the paging message, the method further includes: sending first indication information, the first indication information being used to instruct the target terminal device to receive the second part of the paging message. The RAN instructs the target terminal device to receive both the first and second parts of the paging message through the first indication information; other terminal devices only need to receive the first part of the paging message. Not needing to receive the second part of the paging message helps terminal devices not invited by the IMS system save power.

[0009] In one possible implementation, the first indication information includes a bitmap, where each bit in the bitmap corresponds to a terminal device. The value of the bit corresponding to the target terminal device is used to indicate that the target terminal device receives the second part of the paging message. Indicating the target terminal device through a bitmap is simple, convenient, and helps to save the overhead of the first indication information.

[0010] In one possible implementation, the method further includes: sending second indication information, the second indication information being used to indicate the resources for the target terminal device to receive the paging message. In this implementation, the RAN can indicate the resources corresponding to the paging message containing the SIP request message through the second indication information, thereby facilitating the target terminal device to receive the paging message containing the SIP request message.

[0011] In one possible implementation, the second indication information includes indication information for a first resource, indication information for a second resource, and an identifier for a first terminal device. The first resource is used to transmit paging messages that do not contain the SIP request message; the second resource is used to transmit paging messages that contain the SIP request message. The first terminal device identifier is used to indicate the terminal device receiving the paging message on the second resource, and the target terminal device belongs to the first terminal device. In this implementation, the resources used for receiving paging messages by the target terminal device invited by the IMS system and the resources used for receiving paging messages by terminal devices not invited by the IMS system can be different. The RAN can respectively indicate the first resource for transmitting paging messages that do not contain the SIP request message and the second resource for transmitting paging messages that contain the SIP request message, and indicate which terminal devices need to receive paging messages on the second resource, thereby facilitating the target terminal device to receive paging messages containing the SIP request message, and also enabling other terminal devices to receive paging messages that do not contain the SIP request message on the first resource.

[0012] In one possible implementation, the method further includes receiving the paging message before sending it. In this implementation, the paging message sent by the RAN is not generated by the RAN itself, and the RAN does not add a SIP request message to the paging message. Optionally, the paging message forwarded by the RAN may be sent by the AMF or by another RAN.

[0013] In one possible implementation, before sending the paging message, the method further includes: receiving the SIP request message and generating the paging message. In this implementation, the target terminal device may be in an inactive state, so the RAN may receive a SIP request message, such as a SIP request message sent by the UPF, instead of a paging message sent by the AMF. Therefore, the RAN needs to generate a paging message containing the SIP request message.

[0014] In one possible implementation, the method further includes sending the SIP request message to other radio access network devices in the radio access network notification area (RNA). Since the target terminal device may be in an inactive state, the RAN cannot determine whether the target terminal device is still within the RAN's coverage area. Therefore, the RAN sends a paging message to other RANs in the RNA, so that the other RANs in the RNA broadcast the paging message, enabling the target terminal device to receive the paging message.

[0015] In one possible implementation, the connection message is a Radio Resource Control (RRC) Establishment Request message or an RRC Reconfiguration message.

[0016] Secondly, embodiments of this application provide a communication method, which can be executed by a terminal device, or by a module (e.g., a chip, chip system, or processor) applied to the terminal device, or by a logical node, logical module, or software that implements all or part of the functions of the terminal device.

[0017] Taking the application of this method to a terminal device as an example, the method includes: receiving a paging message, the paging message including a Session Initiation Protocol (SIP) request message of the target terminal device; sending a connection message, the connection message being used by the target terminal device to restore network connection, and the connection message including a SIP response message.

[0018] In one possible implementation, the paging message includes a first part and a second part, the second part including the SIP request message; before receiving the paging message, the method further includes: receiving first indication information, the first indication information being used to instruct the target terminal device to receive the second part of the paging message.

[0019] In one possible implementation, the first indication information includes a bitmap, where each bit in the bitmap corresponds to a terminal device, and the value of the bit corresponding to the target terminal device is used to indicate that the target terminal device receives the second part of the paging message.

[0020] In one possible implementation, the method further includes: receiving second indication information, the second indication information being used to instruct the target terminal device on the resources for receiving the paging message.

[0021] In one possible implementation, the second indication information includes indication information for a first resource, indication information for a second resource, and an identifier for a first terminal device; the first resource is used to transmit a paging message that does not contain the SIP request message; the second resource is used to transmit a paging message that contains the SIP request message, and the first terminal device identifier is used to indicate the terminal device receiving the paging message in the second resource, wherein the target terminal device belongs to the first terminal device.

[0022] In one possible implementation, the connection message is a Radio Resource Control (RRC) Establishment Request message or an RRC Reconfiguration message.

[0023] Thirdly, embodiments of this application provide a communication method that can be executed by a network device, or by a module (e.g., a chip, chip system, or processor) applied to the network device, or by a logical node, logical module, or software that implements all or part of the functions of the network device.

[0024] Taking the application of this method to network devices as an example, the method includes: determining the target terminal device for paging based on the received trigger message; obtaining the Session Initiation Protocol (SIP) request message of the target terminal device; and sending a paging message to the access network device, wherein the paging message includes the SIP request message.

[0025] Fourthly, this application also provides a communication device, which may be a wireless access network device, a processor, a chip, or a functional module within the wireless access network device. This communication device has the function of implementing the method described in the first aspect or any implementation thereof. The function can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the aforementioned function.

[0026] In one possible implementation, the communication device includes a processing module and, optionally, an interface module. These modules can perform the corresponding functions described in the first aspect or any implementation thereof, as detailed in the method examples, which will not be repeated here.

[0027] In one possible implementation, the communication device includes a processor configured to support the communication device in performing the corresponding functions described in the first aspect or any implementation thereof. Optionally, the communication device further includes a communication interface and / or a memory. The communication interface is used for sending and receiving frames, information, or data, and for communicating with other devices in the communication system. The memory is coupled to the processor and stores necessary program instructions and data for the communication device.

[0028] Fifthly, this application also provides a communication device, which may be a terminal device, including a processor, chip, or functional module, etc., in the terminal device. This communication device has the function of implementing the method in the second aspect or any implementation thereof. The function can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-described function.

[0029] In one possible implementation, the communication device includes a processing module and, optionally, an interface module. These modules can perform the corresponding functions described in the second aspect or any implementation thereof, as detailed in the method examples, which will not be repeated here.

[0030] In one possible implementation, the communication device includes a processor configured to support the communication device in performing the corresponding functions described in the second aspect or any implementation thereof. Optionally, the communication device further includes a communication interface and / or a memory. The communication interface is used for sending and receiving frames, information, or data, and for communicating with other devices in the communication system. The memory is coupled to the processor and stores necessary program instructions and data for the communication device.

[0031] Sixthly, this application also provides a communication device, which may be a network device, a processor, a chip, or a functional module within the network device, etc. This communication device has the function of implementing the method in the third aspect or any implementation thereof. The function can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-described function.

[0032] In one possible implementation, the communication device includes a processing module and, optionally, an interface module. These modules can perform the corresponding functions described in the third aspect or any implementation thereof, as detailed in the method examples, which will not be repeated here.

[0033] In one possible implementation, the communication device includes a processor configured to support the communication device in performing the corresponding functions described in the third aspect or any implementation thereof. Optionally, the communication device further includes a communication interface and / or a memory. The communication interface is used for sending and receiving frames, information, or data, and for communicating with other devices in the communication system. The memory is coupled to the processor and stores necessary program instructions and data for the communication device.

[0034] In a seventh aspect, embodiments of this application provide a communication system including the communication device described in the fifth aspect and the communication device described in the sixth aspect. Optionally, it may also include the communication device described in the fourth aspect.

[0035] Eighthly, embodiments of this application provide a chip, including: a processor coupled to a memory for storing instructions, wherein when the instructions are executed by the processor, the chip causes the chip to implement the methods described in the first to third aspects and any of their implementations.

[0036] Ninthly, embodiments of this application provide a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the methods described in the first to third aspects and any of their implementations.

[0037] In a tenth aspect, embodiments of this application provide a computer program product containing instructions that, when run on a computer, cause the computer to perform the methods described in the first to third aspects and any of their implementations.

[0038] For the technical effects that can be achieved by any possible implementation of any of the second to tenth aspects mentioned above, please refer to the description of the technical effects that can be achieved by the corresponding implementation scheme in the first aspect mentioned above. Repeated parts will not be discussed. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the IMS session signaling flow.

[0040] Figure 2a , Figure 2b , Figure 2c This is a schematic diagram of the network architecture of the communication system provided in the embodiments of this application;

[0041] Figure 3 A flowchart illustrating a communication method provided in an embodiment of this application;

[0042] Figure 4 This is a resource illustration provided for an embodiment of this application;

[0043] Figure 5 A flowchart illustrating another communication method provided in an embodiment of this application;

[0044] Figure 6 A flowchart illustrating yet another communication method provided in an embodiment of this application;

[0045] Figure 7 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0046] Figure 8 This is a schematic diagram of another communication device provided in an embodiment of this application. Detailed Implementation

[0047] IP Multimedia Subsystem (IMS) is a form of multimedia service that can meet users' needs for newer and more diversified multimedia services. It is an important way to solve the convergence of mobile and fixed networks and introduce differentiated services such as the triple convergence of voice, data and video.

[0048] Common services for terminal devices include voice communication. Existing terrestrial communication networks, based on IMS, can provide voice, video, and information services to terminal devices. In satellite communication scenarios, radio access network (RAN) equipment or user plane function (UPF) network elements can be deployed on satellites, and IMS can also be deployed on satellites. However, due to the limited payload capacity of satellites, IMS systems may also be located on the ground. IMS systems use the Session Initiation Protocol (SIP) to create, modify, and terminate sessions between parties, thereby enabling multimedia services such as voice, video, images, and text.

[0049] IMS session signaling flow can be like Figure 1 As shown.

[0050] Step 1: The calling user (UE1) sends an invitation request.

[0051] An Invite message is a call request sent by the calling user. An Invite message can be a SIP request message and may contain Session Description Protocol (SDP) information.

[0052] The calling user sends the invite message to the proxy calls session control function (P-CSCF) in the access location. P-CSCF1 sends the invite to the serving call session control function (S-CSCF1) in the home location. S-CSCF1 sends the invite to the interrogating call session control function (I-CSCF). I-CSCF sends the invite to S-CSCF2 in the called user's home location. S-CSCF2 sends the invite to P-CSCF2 in the called user's access location. P-CSCF2 then sends the invite to the called user (UE2).

[0053] Step 2: The called user (UE2) sends a 183 message.

[0054] The 183 message is a response message to the SIP request message. It carries the negotiated media type and media encoding / decoding capabilities in the SIP message and initiates resource reservation.

[0055] The called user sends a 183 message to P-CSCF2, P-CSCF2 sends the 183 message to S-CSCF2, S-CSCF2 sends the 183 message to I-CSCF, I-CSCF sends the 183 message to S-CSCF1, S-CSCF1 sends the 183 message to P-CSCF1, and P-CSCF1 sends the 183 message to the calling user.

[0056] Step 3: The calling user sends a PRACK message.

[0057] The calling network initiates resource reservation. After the resource reservation is completed, the calling user sends a PRACK request to indicate that the 183 message has been successfully received and the resource reservation has been completed. The PRACK message serves as a response to the 183 message and provides SDP information for the second time.

[0058] The transmission path of the PRACK message is similar to that of the invite message in step 1, and will not be described again here.

[0059] Step 4: The called user sends a 200 OK (PRACK) message.

[0060] The 200 OK (PRACK) message is a response message sent by the called user to the PRACK message, indicating that the PRACK message has been successfully received.

[0061] The transmission path of the 200 OK (PRACK) message is similar to that of the 183 message in step 2, and will not be described again here.

[0062] Step 5: The called user sends a 180 Ringing message.

[0063] Once the called party's network resources are reserved, if a message indicating that the called party's network resources have been reserved has already been received, a 180 Ringing message will be sent to the calling party's network to indicate that the called party is ringing.

[0064] The transmission path of the 180 Ringing message is similar to that of the 183 message in step 2, and will not be described again here.

[0065] Step 6: The calling user sends a PRACK message.

[0066] The calling user returns a PRACK message to the called network in response to the 180 Ringing message, indicating successful reception of the 180 Ringing message. The transmission path of the PRACK message is similar to that of the invite message in step 1, and will not be described again here.

[0067] Step 7: The called user sends a 200 OK (PRACK) message.

[0068] The 200 OK (PRACK) message is a response message sent by the called user to the PRACK message, indicating that the PRACK message has been successfully received.

[0069] The transmission path of the 200 OK (PRACK) message is similar to that of the 183 message in step 2, and will not be described again here.

[0070] Step 8: The called user sends a 200 OK (invite) message.

[0071] When the called user answers the call, they return a 200 OK response message to the calling network in response to the invite request.

[0072] The transmission path of the 200 OK (invite) message is similar to that of the 183 message in step 2, and will not be described again here.

[0073] Step 9: The calling user sends an ACK message.

[0074] The calling user returns an acknowledgment message to the called network in response to the 200 OK (invite) message, and the calling and called users successfully establish a session.

[0075] The transmission path of the ACK message is similar to that of the invite message in step 1, and will not be described again here.

[0076] If the called user is in an idle state, the called user needs to restore the RRC connection before it can receive SIP messages, resulting in a longer session establishment delay.

[0077] In view of this, embodiments of this application provide a communication method for reducing call establishment latency when the called user is in a non-RRC connection state.

[0078] The technical solutions of this application embodiment can be applied to various communication systems, such as terrestrial communication systems and non-terrestrial network (NTN) communication systems (e.g., satellite communication systems). Satellite communication systems can be integrated with mobile communication systems. For example, mobile communication systems can be 4th generation (4G) communication systems (e.g., Long Term Evolution (LTE) systems), Worldwide Interoperability for Microwave Access (WiMAX) communication systems, 5G communication systems (e.g., New Radio (NR) systems), and future mobile communication systems. Mobile communication systems can also be vehicle-to-everything (V2X) systems, Internet of Things (IoT) systems, etc.

[0079] Figure 2a , Figure 2b and Figure 2c The following are exemplary network architecture diagrams of several communication systems to which embodiments of this application are applicable.

[0080] Figure 2a An exemplary 5G architecture diagram applicable to embodiments of this application is provided. For example... Figure 2a As shown, the network architecture may include UE, RAN, access and mobility management function (AMF), session management function (SMF), policy control function (PCF), unified data management (UDM), network exposure function (NEF), network repository collection (NRF), network slice selection function (NSSF), application function (AF), and data network (DN), etc.

[0081] Radio Access Network (RAN) equipment is used to implement functions related to wireless access. RAN, also known as access network equipment or base station, is used to connect terminals to a wireless network. The RAN can be a base station, an evolved NodeB (eNodeB) in an LTE system or an evolved LTE-A system (LTE-Advanced, LTE-A), a next-generation NodeB (gNB) in a 5G communication system, a transmission reception point (TRP), a base band unit (BBU), a WiFi access point (AP), a base station in a future mobile communication system, or an access node in a WiFi system, etc. RAN can also be a module or unit that performs some of the functions of a base station; for example, it can be a central unit (CU) or a distributed unit (DU). This application does not limit the specific technology or equipment form used in the RAN. In the following embodiments, the RAN is referred to as access network equipment for illustrative purposes. For ease of description, RAN will be used as an example in the following embodiments of this application.

[0082] A terminal device is a device with wireless transceiver capabilities. It connects wirelessly to a wireless access network device to access a communication system. Terminal devices can also be called terminals, user units (UEs), mobile stations, mobile terminals, etc. Terminal devices can be mobile phones, tablets, computers with wireless transceiver capabilities, virtual reality (VR) terminals, augmented reality (AR) terminals, wireless terminals in industrial control, complete vehicles, wireless communication modules within vehicles, telematics boxes (T-boxes), roadside units (RSUs), terminal devices in autonomous driving, terminal devices in Internet of Things (IoT) networks, terminal devices in remote medical care, terminal devices in smart grids, terminal devices in transportation safety, terminal devices in smart cities, or terminal devices in smart homes, etc. This application's embodiments are not limited to these specific examples.

[0083] Mobility Management (AM) elements are control plane network elements provided by the operator's network, responsible for access control and mobility management of terminal devices accessing the operator's network. These functions include mobility state management, allocation of temporary user identities, authentication, and authorization. In 5G, the AMF element may be used. In future communication systems, the AMF element may still be used, or it may have other names; this application does not limit its scope. For ease of description, the following embodiments of this application will use the AMF element as an example.

[0084] The session management network element (SMF) is a control plane network element provided by the operator's network, responsible for managing the protocol data unit (PDU) sessions of terminal equipment. A PDU session is a channel used to transmit PDUs; terminal equipment needs to exchange PDUs with the DN (Digital Network Node) through the PDU session. The SMF is responsible for establishing, maintaining, and deleting PDU sessions. The session management network element includes session management (such as session establishment, modification, and release, including tunnel maintenance between user plane network elements and access network equipment), user plane network element selection and control, service and session continuity (SSC) mode selection, roaming, and other session-related functions. In 5G, the session management network element can be an SMF. In future communication systems, the session management network element can still be an SMF, or it may have other names; this application does not limit this. For ease of description, the following embodiments of this application will use an SMF as an example.

[0085] User plane network elements are gateways provided by the operator, serving as the gateway for communication between the operator's network and the DN (Digital Network Provider). User plane network elements include user plane-related functions such as packet routing and transmission, packet inspection, service usage reporting, Quality of Service (QoS) processing, uplink packet inspection, and downlink packet storage. In 5G, user plane network elements can be UPF (User Plane Function), and in future communication systems, user plane network elements may still be UPF or have other names; this application does not limit this. For ease of description, the following embodiments of this application will use UPF as an example.

[0086] It should be understood that Figure 2a This is merely one example of an applicable network architecture; real-world network architectures may include more than [examples of applicable network architectures]. Figure 2aMore or fewer network elements. For example, the architecture may also include network data analytics function (NWDAF), unified data repository (UDR), network slice selection function (NSSF), authentication server function (AUSF), etc.

[0087] Figure 2b and Figure 2c An exemplary schematic diagram of an NTN communication system is provided. Figure 2b and Figure 2c The communication system shown may include satellites, network equipment, and terminal equipment. It may also include gateways and core network equipment. Figure 2b and Figure 2c An exemplary network architecture combining NTN and terrestrial networks is illustrated below. This will be described in conjunction with the accompanying drawings.

[0088] The satellite can be a HEO satellite, a geostationary earth orbit (GEO) satellite, a medium earth orbit (MEO) satellite, a low earth orbit (LEO) satellite, or a very low earth orbit (VLEO) satellite. This application does not limit the satellite's operating mode; for example, the satellite's operating mode can be transparent mode or regenerative mode. Figure 2b This illustration uses the satellite's transparent transmission mode as an example. Figure 2c This illustration uses the satellite's operating mode as the regeneration mode as an example.

[0089] When a satellite operates in transparent mode, it provides transparent relay functionality. A gateway functions as a network device (e.g., a base station) or partially functions as one, and in this case, the gateway can be considered a network device (e.g., a base station). Alternatively, the network device (e.g., the base station) can be deployed separately from the gateway. In this case, the feeder link latency includes both the latency from the satellite to the gateway and the latency from the gateway to the ground base station. The transparent mode discussed later assumes that the gateway and the ground base station are located together or close to each other. For cases where the gateway and the ground base station are far apart, the feeder link latency is simply the sum of the latency from the satellite to the gateway and the latency from the gateway to the ground base station.

[0090] When a satellite operates in regenerative mode, it has data processing capabilities and functions as a network device (such as a base station) or partially functions as a network device (such as a base station). In this case, the satellite can be regarded as a network device (such as a base station).

[0091] Satellites can communicate wirelessly with terminal devices via broadcast communication signals and navigation signals. Optionally, each satellite can provide communication, navigation, and positioning services to terminal devices through multiple beams. For example, each satellite uses multiple beams to cover the service area, and the relationship between different beams can be one or more of time-division, frequency-division, and space-division.

[0092] A gateway (also known as a ground station, earth station, or gateway) is a network device used to connect satellites and ground-based network equipment (such as ground base stations). One or more satellites can connect to one or more ground-based network devices (such as ground base stations) through one or more gateways; this is not a limitation. The link between the satellite and the terminal device is called a service link, and the link between the satellite and the gateway is called a feeder link. Network equipment can be deployed separately from the gateway; therefore, the latency of the feeder link can include both the latency from the satellite to the gateway and the latency from the gateway to the network equipment.

[0093] The network devices in this application embodiment may include network devices deployed on non-terrestrial surfaces (such as satellites or satellite base stations), network devices deployed on gateways, or network devices deployed on the ground (such as terrestrial base stations). For example, radio access network (RAN) nodes in mobile communication systems, RAN nodes in open access network (O-RAN or ORAN) systems, etc.

[0094] The core network (CN) primarily provides functions such as user access control, mobility management, session management, user security authentication, and accounting. The core network can consist of multiple functional units, categorized into control plane and data plane functional entities. For example, the core network may include the access and mobility management function (AMF), user plane function (UPF), and session management function (SMF). The AMF entity is responsible for user access management, security authentication, and mobility management. The UPF entity is responsible for managing user plane data transmission and traffic statistics. The SMF entity is responsible for managing protocol data unit (PDU) sessions of terminal devices.

[0095] Air interface: refers to the wireless link between the terminal device and the base station.

[0096] Xn interface: This refers to the interface between satellite base stations, mainly used for signaling interactions such as handover.

[0097] NG interface: This refers to the interface between the base station and the core network, or the interface between the ground station and the core network, or the interface between the satellite base station and the ground station (in this case, the interface is a wireless link). It mainly exchanges signaling such as NAS of the core network and user service data.

[0098] Figure 3 A flowchart illustrating the communication method provided in the embodiments of this application is shown below. Figure 3 The communication method may include the following steps:

[0099] Step 301: The RAN sends a paging message, which includes a SIP request message from the target terminal device.

[0100] The target terminal device is the called user equipment, and the target terminal device is in a non-RRC connected state, such as RRC idle state or RRC inactive state.

[0101] In the New Radio (NR) scenario, RRC has three states: connected (also known as active), idle, and inactive.

[0102] In RRC connected mode, the terminal device maintains a connection with the RAN and core network. This means the terminal device can receive and send data. In RRC connected mode, the terminal device can perform voice calls, data transmission, and other operations.

[0103] When a terminal device has no data transmission needs, it can enter the RRC idle state. In this state, the terminal device releases its connection with the RAN and core network. The terminal device can still search for networks, register with networks, and receive broadcast information, but it cannot transmit data. For example, a mobile phone is usually in the RRC idle state when it is in standby mode.

[0104] The RRC inactive state is a state between RRC connected and RRC idle. In this state, the terminal device maintains a connection with the core network but releases its connection with the RAN. While in the RRC inactive state, the terminal device can perform some lightweight operations, such as receiving paging messages or broadcast information, but cannot transmit data. This state is typically used to save power or reduce resource consumption during network handover.

[0105] In this embodiment of the application, the target terminal device is in a non-RRC connected state, such as an RRC idle state or an RRC inactive state, before the RAN sends a paging message. Therefore, when the target terminal device is the called user, a session cannot be directly established for data transmission.

[0106] In traditional technical solutions, the target terminal device needs to first perform random access to restore the RRC connection state before it can receive SIP request messages and then perform operations such as responding to SIP request messages and reserving resources for session establishment. This results in a long delay in establishing a session between the calling user and the called user.

[0107] In step 301 of this application embodiment, the paging message sent by the RAN contains a SIP request message, and it is not necessary to wait until the random access process of the terminal device is completed before sending the SIP request message to the terminal device, thereby helping to save the time for the calling user and the called user to establish a session.

[0108] Step 302: The target terminal device sends a connection message, which is used by the target terminal device to restore the network connection, and the connection message includes a SIP response message.

[0109] After receiving a paging message from the RAN, the target terminal device can perform the operation to restore network connectivity. Since the paging message contains a SIP request message, the target terminal device can also respond to the SIP request message during the network connectivity restoration process, and send the SIP response message as part of the network connectivity restoration message to the RAN or AMF. For example, the target terminal device can include the SIP response message in an RRC setup request message or in an RRC reconfiguration message.

[0110] Optionally, the SIP response message can be a non-access stratum (NAS) message. In this case, after receiving the SIP response message, the RAN forwards it to the AMF so that the AMF can determine that the target terminal device has responded to the SIP request message.

[0111] This application uses the AMF in a 5G communication system as an example for illustration. When the above method is applied to other communication systems, the AMF can also be replaced by other network elements with access management functions.

[0112] In the above embodiments of this application, the RAN sends a paging message to the target terminal device, which is the called user and is in a non-RRC connected state. This paging message includes a SIP request message, eliminating the need to send the SIP request message to the target terminal device only after it has restored its RRC connected state. This helps reduce the latency of establishing a session between the calling user and the target terminal device. Furthermore, because the paging message contains a SIP request message, the target terminal device can respond to the SIP request message during network connection restoration and send a SIP response message to the RAN / AMF using a message for network connection restoration. This avoids having to receive and respond to the SIP message after network connection restoration, further reducing the latency of establishing a session between the calling user and the target terminal device and improving user experience.

[0113] In one possible implementation, the paging message sent by the RAN may include two parts: the first part may include a traditional paging message, which may include indication information for which terminal devices should resume connection; the second part may include the aforementioned SIP request message.

[0114] For terminal devices that are in a disconnected state but have not been invited by the IMS system, receiving the first part of the paging message is sufficient; the second part is optional. However, for target terminal devices that are in a disconnected state but have been invited by the IMS system, both the first and second parts need to be received to respond to the SIP request message during the network connection restoration process.

[0115] In one possible implementation, before sending the paging message, the RAN can send a first indication message to instruct the terminal devices that need to receive the second part of the paging message, i.e., to instruct the target terminal devices to receive the second part of the paging message. By instructing the target terminal devices to receive the second part of the paging message through the first indication message, terminal devices that have not been invited by the IMS system can choose not to receive the second part of the paging message. This ensures that not all terminal devices need to receive the second part of the paging message, helping terminal devices that have not been invited by the IMS system to save power.

[0116] Optionally, the first indication information may include the identifier of the target terminal device, so that the terminal device receiving the first indication information can determine whether it needs to receive the second part of the paging message based on the identifier.

[0117] Optionally, the first indication information may also include a bitmap, in which each bit corresponds to a terminal device. When the bit value is the first value, it indicates that the terminal device corresponding to the bit needs to receive the second part of the paging message. When the bit value is the second value, it indicates that the terminal device corresponding to the bit does not need to receive the second part of the paging message.

[0118] The terminal devices corresponding to the bits in the aforementioned bitmap can be the terminal devices indicated in the paging message to restore the connection. For example, if the RAN needs to page terminal devices 1, 2, 3, and 4 to restore these four terminal devices from the idle state to the connected state, where terminal device 2 is the target terminal device invited by the IMS system, then the bitmap in the first indication information sent by the RAN can include four bits: the first bit corresponds to terminal device 1, and its value is "0", indicating that terminal device 1 can choose not to receive the second part of the paging message; the second bit corresponds to terminal device 2, and its value is "1", indicating that terminal device 2 needs to receive the second part of the paging message; the third bit corresponds to terminal device 3, and its value is "0", indicating that terminal device 3 can choose not to receive the second part of the paging message; the fourth bit corresponds to terminal device 4, and its value is "0", indicating that terminal device 4 can choose not to receive the second part of the paging message. Then, the RAN sends a paging message, which includes a first part and a second part. The second part is a SIP request message from the IMS system. Terminal device 1 and terminal device 3 receive only the first part of the paging message according to the first instruction information, while terminal device 2 receives both the first and second parts of the paging message according to the first instruction information, thereby obtaining the SIP request message and responding to the SIP request message during the network connection restoration process.

[0119] The time-frequency resources for paging messages sent by the RAN can be indicated by downlink control information (DCI). One possible design is to add the aforementioned first indication information to the DCI, which requires minimal modification to the existing communication protocol and is easy to implement. Alternatively, the first indication information can be added to other messages.

[0120] In another possible implementation, a conventional paging message can be sent on a first resource, while a paging message containing a SIP request message can be sent on a second resource; before sending the paging message, the RAN can also send a second indication message, which is used to indicate the aforementioned second resource.

[0121] Alternatively, the paging message may still consist of two parts. The first part may include a traditional paging message, including indication information to indicate which terminal devices should resume connection; the second part includes the aforementioned SIP request message. The first part of the paging message is sent on the first resource, and the second part is sent on the second resource. Before sending the paging message, the RAN may also send second indication information to indicate the aforementioned second resource.

[0122] In traditional schemes, the time-frequency resources of paging messages sent by the RAN can be indicated by the DCI. Based on this, one possible design is to add the aforementioned second indication information to the DCI, which requires minimal modification to the existing communication protocol and is easy to implement. Alternatively, the first indication information can also be added to other messages.

[0123] For example, the DCI sent by the RAN indicates two resources, PO1 and PO2, where PO1 is used to carry paging messages for non-IMS services, and PO2 is used to carry paging messages for voice services (or other services of the IMS system).

[0124] Optionally, the PO2 resource may include two parts: the first part corresponds to the first part of the paging message, and the second part corresponds to the second part of the paging message. That is, the second part of the PO2 resource is used to carry the SIP request message in the paging message, such as... Figure 4 As shown. In this case, when DCI indicates PO2 resources, it can indicate the first part of the resources and the second part of the resources in PO2 resources respectively, or it can indicate the first part of the resources in PO2 resources, while the second part of the resources has a mapping relationship with the first part of the resources. The target terminal device can determine the second part of the resources according to the pre-configured mapping relationship and the first part of the resources.

[0125] In addition, the DCI may also include the identifier of the terminal device corresponding to PO1, i.e., the terminal device that has not been invited by the IMS system. The DCI may also include the identifier of the terminal device corresponding to PO2, i.e., the identifier of the target terminal device that has been invited by the IMS system. Upon receiving the DCI, a terminal device in a disconnected state determines, based on its own identifier, whether to receive a paging message and on which resource to receive it. For terminal devices that have not been invited by the IMS system, the identifier corresponding to resource PO1 indicates that they should receive paging messages on resource PO1; for target terminal devices invited by the IMS system, the identifier corresponding to resource PO2 indicates that they need to receive paging messages on resource PO2.

[0126] Optionally, if terminal device A has both non-IMS and IMS services, the RAN can add the identifier of terminal device A only to the terminal device identifier corresponding to resource PO2. In this case, terminal device A will only receive paging messages containing SIP messages on resource PO2. Alternatively, the RAN can add the identifier of terminal device A to the terminal device identifiers corresponding to resources PO1 and PO2. In this case, the terminal device will receive paging messages on both resources PO1 and PO2.

[0127] In one possible implementation, the paging message sent by the RAN can come from the AMF.

[0128] In this implementation, the target terminal device can be in an idle state before receiving the paging message, meaning that the terminal device has released its connection with both the RAN and the core network. When the target terminal device is in an idle state, the AMF typically sends the paging message, and the RAN forwards the paging message sent by the AMF. Therefore, the paging message containing the SIP request message is generated by the AMF.

[0129] The AMF determines that the target terminal device needs to be paged based on the received trigger message, and that the target terminal device is invited by the IMS system, which can also be understood as the target terminal device having IMS service. Then, the AMF can obtain the SIP request message of the target terminal device, generate a paging message containing the SIP request message, and send it to the RAN so that the RAN can broadcast the paging message.

[0130] In a specific example, after receiving a SIP request message, the IMS system sends the SIP request message to the UPF (this embodiment uses a UPF network element in a 5G communication system as an example; when the above method is applied to other communication systems, it can also be other network elements with user plane functions). The UPF sends a trigger message (such as a trigger message) to the AMF to cause the AMF to page the target terminal device. After receiving the trigger message, the AMF can send a paging message to the RAN, which contains the identifier of the target terminal device. Then, the RAN broadcasts the paging message to cause the target terminal device to restore the connection and respond to the SIP request.

[0131] Figure 5 An exemplary flowchart is provided for paging a target terminal device by an AMF, such as... Figure 5 As shown, the process may include the following steps:

[0132] Step 501: The IMS system sends a SIP request message to the UPF.

[0133] This SIP request message is a call request sent by the calling user. This SIP request message can be... Figure 1 The `invite` message shown. This UPF can be the target terminal device (i.e., the called user).

[0134] Step 502: UPF sends a trigger message to AMF.

[0135] This trigger message is a control plane message used to indicate that the target terminal device has been invited by the IMS system so that the AMF can page the target terminal device.

[0136] Step 503: AMF obtains the SIP request message from UPF.

[0137] The trigger sent by UPF may not contain a SIP request message. In this case, if AMF determines that the target terminal device has IMS service, it will obtain the target terminal device's SIP request message from UPF.

[0138] Step 504: The AMF sends a paging message, which includes a SIP request message.

[0139] After receiving the SIP request message from the target terminal device, the AMF generates a paging message containing the SIP request message and sends it to the RAN. Optionally, the AMF can fill the paging message with the SIP request message. The paging message can include a first part and a second part, where the first part is the traditional paging message and the second part is the aforementioned SIP request message.

[0140] Compared to existing technologies that send SIP request messages to the target terminal device only after the target terminal device has reconnected, this method allows the target terminal device to receive the SIP request message in advance, thus enabling it to respond to the SIP request message earlier.

[0141] Step 505: RAN broadcasts a paging message.

[0142] After receiving a paging message from the AMF, the RAN can broadcast the paging message so that the target terminal device can receive the paging message and restore the connection.

[0143] Optionally, after receiving a paging message, the RAN can also generate a DCI based on the SIP request message in the information message. The DCI can instruct the target terminal device to receive the second part of the paging message containing the SIP request message, or the DCI can instruct the target terminal device to receive the paging message containing the SIP request message on the PO2 resource. The RAN first sends the DCI to enable the target terminal device to determine whether it needs to receive the second part of the paging message or to determine whether to receive the paging message on the PO2 resource, and then sends the paging message.

[0144] Step 506: The target terminal device restores the network connection and adds a SIP response message to the message sent for restoring the network connection.

[0145] Upon receiving the paging message, the target terminal device restores its network connection and simultaneously responds to the SIP request message. The process of restoring the network connection may include the process of restoring the connection with the RAN (i.e., the random access process) and the process of restoring the network connection with the core network.

[0146] For example, the target terminal device can execute a contention-based random access procedure: the target terminal device first sends message 1 (msg1) to the RAN, containing one or more preambles; the RAN sends message 2 (msg2) to the target terminal device, which is the random access response message; the target terminal device sends message 3 (msg3) to the RAN, which can be an RRC setup request message (RRCsetupRequest) to establish an RRC connection; the RAN sends message 4 (msg4) to the target terminal device, which can indicate connection establishment and may also include a conflict resolution message. The target terminal device can carry a SIP response message in the RRC setup request message, thereby completing the response to the SIP request message during the random access process. This SIP response message is... Figure 1 The 183 message in step 2 of the illustrated embodiment.

[0147] For example, during the process of restoring connection with the core network, the target terminal device can also send a SIP response message in an RRC reconfiguration message to the RAN / AMF, thereby completing the response to the SIP request message during the connection restoration process. This SIP response message is... Figure 1 The 183 message in step 2 of the illustrated embodiment. RRC reconfiguration messages are typically used to modify parameters such as radio bearer configuration, measurement configuration, and handover configuration of terminal devices. When the target terminal device needs to modify the corresponding parameters, it can send the modified parameters along with the SIP response message to the RAN / AMF via the RRC reconfiguration message. Alternatively, the target terminal device can also send only the SIP response message via the RRC reconfiguration message.

[0148] In another possible implementation, the paging message sent by the RAN can be generated by the RAN itself or sent by other RANs.

[0149] In this implementation, the target terminal device can be in an inactive state before receiving the paging message. That is, the terminal device releases its connection with the RAN but maintains a connection with the core network. When the target terminal device is in an inactive state, the paging message is typically sent by the RAN; therefore, the paging message containing the SIP request message is generated by the RAN.

[0150] In a specific example, after receiving a SIP request message, the IMF system forwards it to the UPF. The UPF then forwards the video request message to the last serving RAN (RAN) providing last-serving service to the target terminal device. Upon receiving the SIP request message, the last serving RAN determines that it has released its connection with the target terminal device and generates a paging message containing the aforementioned SIP request message. The last serving RAN broadcasts this paging message and forwards it to other RANs within the Radio Access Network Notification Area (RNA). Because the last serving RAN has released its connection with the target terminal device, it cannot determine whether the target terminal device is still within its coverage area. Therefore, the last serving RAN forwards the paging message to other RANs within the RNA, enabling them to broadcast the paging message and allowing the target terminal device to receive it.

[0151] Figure 6 An exemplary flowchart is provided for paging a target terminal device by an AMF, such as... Figure 6As shown, the process may include the following steps:

[0152] Step 601: The IMS system sends a SIP request message to the UPF.

[0153] This SIP request message is a call request sent by the calling user. This SIP request message can be... Figure 1 The `invite` message shown. This UPF can be the target terminal device (i.e., the called user).

[0154] Step 602: UPF sends a trigger message to RAN1.

[0155] RAN1 is the last serving RAN of the target terminal equipment.

[0156] This trigger message is a control plane message used to indicate that the target terminal equipment has been invited by the IMS system to enable RAN1 to page the target terminal equipment.

[0157] Step 603: RAN1 obtains the SIP request message from the UPF.

[0158] The trigger sent by UPF may not contain a SIP request message. In this case, when RAN1 determines that the target terminal device has IMS service, it will obtain the target terminal device's SIP request message from UPF.

[0159] Optionally, in step 602 above, the UPF can also send the SIP request message to the AMF, which will trigger RAN1 to page the target terminal device. In step 603, RAN1 can obtain the SIP request message from the AMF.

[0160] Step 604: RAN1 generates a paging message, which includes a SIP request message.

[0161] After receiving the SIP request message from the target terminal device, RAN1 generates a paging message containing the SIP request message. Optionally, RAN1 can fill the paging message with the SIP request message. The paging message can include a first part and a second part, where the first part is the traditional paging message and the second part is the aforementioned SIP request message.

[0162] Step 605: RAN1 sends paging messages to other RANs in the RNA.

[0163] RAN1 can send a paging message containing a SIP request message to other RANs in the RNA, so that the other RANs can page the target terminal device together.

[0164] Step 606, RAN1 and other RANs broadcast paging messages.

[0165] RAN1 and other RANs broadcast paging messages so that the target terminal equipment receives the paging message and restores the connection.

[0166] The execution order of RAN1 broadcasting the paging message and RAN1 sending the paging message to other RANs is not limited in this application embodiment. RAN1 may also broadcast the paging message first and then send the paging message to other RANs.

[0167] Optionally, before broadcasting the paging message, RAN1 and / or other RANs may generate a DCI based on the SIP request message in the information message. The DCI may indicate that the target terminal device needs to receive the second part of the paging message containing the SIP request message, or the DCI may indicate that the target terminal device receives the paging message containing the SIP request message on the PO2 resource. RAN1 and / or other RANs first send the DCI to enable the target terminal device to determine that it needs to receive the second part of the paging message, or to determine that it needs to receive the paging message on the PO2 resource, and then broadcast the paging message.

[0168] Compared to existing technologies that send SIP request messages to the target terminal device only after the target terminal device has reconnected, the above embodiments enable the target terminal device to receive the SIP request message in advance, and thus respond to the SIP request message in advance.

[0169] Step 607: The target terminal device restores the network connection and adds a SIP response message to the message sent for restoring the network connection.

[0170] Upon receiving the paging message, the target terminal device restores its network connection and simultaneously responds to the SIP request message. The process of restoring the network connection may include the process of restoring the connection with the RAN (i.e., the random access process) and the process of restoring the network connection with the core network.

[0171] For example, during the random access procedure, the target terminal device can send the SIP response message to the RAN / AMF via a message used for random access, such as sending the SIP response message to the RAN / AMF via an RRC setup request message; or, the target terminal device can also send the SIP response message to the RAN / AMF during the core network connection recovery process, such as sending the SIP response message to the RAN / AMF via an RRC reconfiguration message.

[0172] Through the above process, the target terminal device completes the response to the SIP request message during the network connection restoration process. Compared with the prior art, which sends the SIP request message to the target terminal device after the connection is restored, the target terminal device can receive the SIP request message in advance and respond to the SIP request message during the network connection restoration process, thereby helping to reduce session establishment latency and improve user experience.

[0173] Figure 7 This is a schematic diagram of a communication device according to an embodiment of this application. The communication device includes an interface module 701 and a processing module 702. The processing module 702 is used to process data by the communication device. The interface module 701 is used to receive content from the communication device and other units or network elements, or to send content from the communication device and other units or network elements. It should be understood that the processing module 702 in this embodiment can be implemented by a processor or processor-related circuit components (or, referred to as processing circuitry), and the interface module 701 can be implemented by a receiver / transmitter or receiver / transmitter-related circuit components.

[0174] For example, the communication device may be a communication device equipment, or it may be a chip or other combination device or component that has the functions of the aforementioned communication device equipment applied in the communication device equipment.

[0175] When the communication device is a RAN, the processing module 702 is used to: send a paging message through the interface module 701, the paging message including a Session Initiation Protocol (SIP) request message for the target terminal device; and receive a connection message through the interface module 701, the connection message being used by the target terminal device to restore network connection, and the connection message including a SIP response message.

[0176] In addition, the above modules can also be used to support Figures 3 to 6 Other processes performed by the RAN in the illustrated embodiment. The beneficial effects are described above and will not be repeated here.

[0177] When the communication device is a terminal device, the processing module 702 is used to: receive a paging message through the interface module 701, the paging message including a Session Initiation Protocol (SIP) request message of the target terminal device; and send a connection message through the interface module 701, the connection message being used by the target terminal device to restore network connection, and the connection message including a SIP response message.

[0178] In addition, the above modules can also be used to support Figures 3 to 6 Other processes performed by the terminal device in the illustrated embodiment. The beneficial effects are described above and will not be repeated here.

[0179] When the communication device is a network device (the access and mobility management function network element in the aforementioned embodiments), the processing module 702 is used to: determine the paging target terminal device according to the received trigger message; obtain the Session Initiation Protocol (SIP) request message of the target terminal device; and send a paging message to the access network device through the interface module 701, wherein the paging message includes the SIP request message.

[0180] In addition, the above modules can also be used to support Figures 3 to 6 Other processes performed by the AMF in the illustrated embodiment. The beneficial effects are described above and will not be repeated here.

[0181] Figure 8 This is a schematic diagram of another communication device provided according to an embodiment of this application. The communication device includes a processor 801, a communication interface 802, and may further include a memory 803 and a bus 804. The processor 801, communication interface 802, and memory 803 can be interconnected via the bus 804. The bus 804 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus 804 can be divided into an address bus, a data bus, and a control bus, etc. For ease of illustration, Figure 8 The symbol is represented by only one line, but this does not mean that there is only one bus or one type of bus.

[0182] Processor 801 may be a central processing unit (CPU), a network processor (NP), or a combination of CPU and NP. The processor may further include hardware chips. These hardware chips may be application-specific integrated circuits (ASICs), programmable logic devices (PLDs), or combinations thereof. The PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. Memory 803 may be volatile memory or non-volatile memory, or may include both. The non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM), which is used as an external cache.

[0183] The processor 801 is used to implement the data processing operation of the communication device, and the communication interface 802 is used to implement the receiving and sending operations of the communication device.

[0184] When the communication device is a RAN, the processor 801 is configured to: send a paging message through the communication interface 802, the paging message including a Session Initiation Protocol (SIP) request message for the target terminal device; and receive a connection message through the communication interface 802, the connection message being used by the target terminal device to restore network connection, and the connection message including a SIP response message.

[0185] In addition, the above modules can also be used to support Figures 3 to 6 Other processes performed by the RAN in the illustrated embodiment. The beneficial effects are described above and will not be repeated here.

[0186] When the communication device is a terminal device, the processor 801 is configured to: receive a paging message through the communication interface 802, the paging message including a Session Initiation Protocol (SIP) request message from the target terminal device; and send a connection message through the communication interface 802, the connection message being used by the target terminal device to restore network connection, and the connection message including a SIP response message.

[0187] In addition, the above modules can also be used to support Figures 3 to 6 Other processes performed by the terminal device in the illustrated embodiment. The beneficial effects are described above and will not be repeated here.

[0188] When the communication device is a network device (the access and mobility management function network element in the aforementioned embodiments), the processor 801 is configured to: determine the paging target terminal device based on the received trigger message; obtain the Session Initiation Protocol (SIP) request message of the target terminal device; and send a paging message to the access network device through the communication interface 802, wherein the paging message includes the SIP request message.

[0189] In addition, the above modules can also be used to support Figures 3 to 6 Other processes performed by the AMF in the illustrated embodiment. The beneficial effects are described above and will not be repeated here.

[0190] Based on the same technical concept, embodiments of this application provide a communication system including the aforementioned RAN and AMF. Optionally, it may also include the aforementioned terminal equipment.

[0191] Based on the same technical concept, embodiments of this application provide a chip, including: a processor coupled to a memory for storing instructions, wherein when the instructions are executed by the processor, the chip enables the chip to implement the method described in any of the above implementation methods.

[0192] Based on the same technical concept, embodiments of this application also provide a computer-readable storage medium storing computer-readable instructions, which, when executed on a computer, cause the above-described method embodiments to be performed.

[0193] Based on the same technical concept, this application also provides a computer program product containing instructions that, when run on a computer, cause the above-described method embodiments to be executed.

[0194] Based on the same technical concept, embodiments of this application also provide a computer-readable storage medium storing computer-readable instructions, which, when executed on a computer, cause the above-described method embodiments to be performed.

[0195] Based on the same technical concept, this application also provides a computer program product containing instructions that, when run on a computer, cause the above-described method embodiments to be executed.

[0196] It should be understood that in the description of this application, terms such as "first" and "second" are used only for distinguishing purposes and should not be construed as indicating or implying relative importance or order. References to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in still other embodiments" appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0197] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0198] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0199] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0200] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0201] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0202] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of the embodiments of this application. Therefore, if these modifications and variations to the embodiments of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. A communication method, characterized in that, The method includes: Send a paging message, the paging message including a Session Initiation Protocol (SIP) request message from the target terminal device; A connection message is received, which is used by the target terminal device to restore network connection, and the connection message includes a SIP response message.

2. The method according to claim 1, characterized in that, The paging message includes a first part and a second part, wherein the second part includes the SIP request message; Before sending the paging message, the method further includes: Send a first instruction message, which is used to instruct the target terminal device to receive the second part of the paging message.

3. The method according to claim 2, characterized in that, The first indication information includes a bitmap, where each bit in the bitmap corresponds to a terminal device, and the value of the bit corresponding to the target terminal device is used to indicate that the target terminal device receives the second part of the paging message.

4. The method according to any one of claims 1-3, characterized in that, The method further includes: Send a second instruction message, which is used to instruct the target terminal device to receive the paging message.

5. The method according to claim 4, characterized in that, The second indication information includes indication information for the first resource, indication information for the second resource, and the identifier of the first terminal device; The first resource is used to transmit paging messages that do not contain the SIP request message; The second resource is used to transmit a paging message containing the SIP request message, and the first terminal device identifier is used to indicate the terminal device receiving the paging message in the second resource, wherein the target terminal device belongs to the first terminal device.

6. The method according to any one of claims 1-5, characterized in that, Before sending the paging message, the method further includes: Receive the paging message.

7. The method according to any one of claims 1-5, characterized in that, Before sending the paging message, the method further includes: Receive the SIP request message; Generate the paging message.

8. The method according to claim 7, characterized in that, The method further includes: The SIP request message is sent to other radio access network devices in the radio access network notification area (RNA).

9. The method according to any one of claims 1-8, characterized in that, The connection message is either a Radio Resource Control (RRC) Establishment Request message or an RRC Reconfiguration message.

10. A communication method, characterized in that, The method is applied to a target terminal device, and the method includes: Receive a paging message, the paging message including a Session Initiation Protocol (SIP) request message from the target terminal device; A connection message is sent, which is used by the target terminal device to restore network connection, and the connection message includes a SIP response message.

11. The method according to claim 10, characterized in that, The paging message includes a first part and a second part, wherein the second part includes the SIP request message; Before receiving the paging message, the method further includes: Receive first instruction information, which is used to instruct the target terminal device to receive the second part of the paging message.

12. The method according to claim 11, characterized in that, The first indication information includes a bitmap, where each bit in the bitmap corresponds to a terminal device, and the value of the bit corresponding to the target terminal device is used to indicate that the target terminal device receives the second part of the paging message.

13. The method according to any one of claims 10-11, characterized in that, The method further includes: Receive second instruction information, which is used to instruct the target terminal device to receive the paging message.

14. The method according to claim 13, characterized in that, The second indication information includes indication information for the first resource, indication information for the second resource, and the identifier of the first terminal device; The first resource is used to transmit paging messages that do not contain the SIP request message; The second resource is used to transmit a paging message containing the SIP request message, and the first terminal device identifier is used to indicate the terminal device receiving the paging message in the second resource, wherein the target terminal device belongs to the first terminal device.

15. The method according to any one of claims 10-14, characterized in that, The connection message is either a Radio Resource Control (RRC) Establishment Request message or an RRC Reconfiguration message.

16. A communication method, characterized in that, The method includes: The target terminal device to be paged is determined based on the received trigger message; Obtain the Session Initiation Protocol (SIP) request message from the target terminal device; Send a paging message to the access network device, the paging message including the SIP request message.

17. A communication device, characterized in that, include: At least one processor coupled to a memory for storing a program or instructions which, when executed by the processor, cause the apparatus to perform the method as described in any one of claims 1-16.

18. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1-16.

19. A computer program product containing instructions, characterized in that, When the instructions are executed on a computer, the computer causes the computer to perform the method as described in any one of claims 1-16.

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