Communication method and communication device

Abstract

Provided are a communication method and a communication device, the method comprising: an access network device receiving a first request from a core network device, the first request being used for requesting a terminal device to join a first multicast group, the first multicast group being a multicast group that has not been established by the access network device; then, a first message number is sent to the terminal equipment, and the first message number is a temporary message number indicated by the access network equipment for the first multicast group; receiving a multicast message of the first multicast group from core network equipment; and sending a second message number to the terminal equipment, wherein the second message number is determined based on the multicast message. Through the method, the terminal equipment can be ensured to successfully join the multicast group in a scene that the terminal equipment applies for joining the multicast group but the access network equipment does not establish the multicast group.

Description

Technical Field

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

[0002] Multicast Broadcast Service (MBS) transmits data from one data source (e.g., a base station) to multiple target terminals, enabling the sharing of network resources (including core and access networks) and improving the utilization of network resources, especially air interface resources. Currently, in the 3rd Generation Partnership Project (3GPP) standard, when a terminal device requests to join a new radio (NR) MBS multicast group, the base station needs to include the multicast message number (multicastHFN-AndRefSN) in the radio resource control (RRC) message to notify the terminal device. The terminal device uses multicastHFN-AndRefSN to initialize the packet data convergence protocol (PDCP) receive window for the multicast bearer and determine the PDCP hyperframe number (HFN). In other words, when a terminal device applies to join an NR MBS multicast group, the base station needs to know which number the current multicast session is sent to. Otherwise, the base station cannot send the multicast message number to the terminal device when it applies to join the NR MBS multicast group, which will cause the terminal device to fail to join the multicast group.

[0003] For example, terminal device 1 receives multicast service A under base station 1, while no terminal device has ever joined multicast service A under base station 2. Terminal device 1 moves from base station 1 to base station 2 and applies to join multicast service A under base station 2. Since base station 2 has never received multicast service A packets from the core network, base station 2 does not know which packet number multicast service A is currently being sent to, and therefore cannot notify terminal device 1 at the air interface which packet number to start receiving from in the PDCP receive window, resulting in terminal device 1's failure to join the multicast group. Therefore, ensuring that terminal devices successfully join the multicast group is a problem that urgently needs to be solved. Summary of the Invention

[0004] This application provides a communication method and a communication device. Based on the method described in this application, it is possible to ensure that the terminal device can successfully join the multicast group.

[0005] In a first aspect, embodiments of this application provide a communication method applied to an access network device. The method includes: receiving a first request from a core network device, the first request being used to request a terminal device to join a first multicast group, the first multicast group being a multicast group that the access network device has not established; sending a first message number to the terminal device, the first message number being a temporary message number indicated by the access network device for the first multicast group; receiving a multicast message from the core network device for the first multicast group; and sending a second message number to the terminal device, the second message number being determined based on the multicast message.

[0006] In this embodiment, when a terminal device requests to join a first multicast group but the access network device has not established the first multicast group, the terminal device can first join the first multicast group based on a temporary first message number. At this time, the small amount of data received will not affect the overall service transmission. After the access network device receives the multicast message of the first multicast group sent by the core network device, the access network device determines the formal second message number based on the multicast message of the first multicast group. The terminal device then rejoins the first multicast group based on the second message number. This ensures that the terminal device can successfully join the first multicast group, while also improving the independence of the access network device in solving problems and reducing the cooperation of other devices.

[0007] In one possible implementation, after receiving the multicast message of the first multicast group from the core network device, the method further includes: storing the multicast message; after sending the second message number to the terminal device, the method further includes: sending the multicast message to the terminal device.

[0008] In this embodiment, after receiving the multicast message of the first multicast group from the core network device, the access network device stores it. Only after the access network device sends a second message number to the terminal device and the terminal device rejoins the first multicast group based on the second message number will the access network device send the multicast message of the first multicast group to the terminal device, thereby improving the reliability of data transmission.

[0009] In one possible implementation, sending a first message number to a terminal device includes: sending a first message to the terminal device, the first message indicating permission to join the first multicast group, the first message including the first message number. In this embodiment, the first message may be an RRC message.

[0010] In one possible implementation, before sending the second message number to the terminal device, the method further includes: sending a second message to the terminal device, the second message indicating exit from the first multicast group; sending the second message number to the terminal device includes: sending a third message to the terminal device, the third message indicating rejoining the first multicast group, the third message including the second message number. In this embodiment, the second message and the third message can be different RRC messages.

[0011] In one possible implementation, sending the second message number to the terminal device includes sending a fourth message to the terminal device, the fourth message indicating that the user should leave and rejoin the first multicast group, the fourth message including the second message number. In this embodiment, the fourth message may be an RRC message.

[0012] In one possible implementation, the access network device includes a centralized unit (CU), which includes a CU-control plane (CP) and a CU-user plane (UP); receiving a first request from the core network device, including: the CU-CP receiving the first request from the core network device; sending a first message number to a terminal device, including: the CU-CP sending the first message number to the terminal device; and receiving multicast messages from the first multicast group of the core network device, including: the CU-UP receiving the multicast messages from the first multicast group of the core network device.

[0013] In one possible implementation, the method further includes: the CU-UP sending the packet data aggregation protocol counter (PDCP COUNT) of the multicast message to the CU-CP; and sending a second message number to the terminal device, including: the CU-CP sending a second message number to the terminal device, the second message number being determined based on the PDCP COUNT of the multicast message.

[0014] This can be understood as follows: CU-UP simply sends the PDCP COUNT of the multicast message to CU-CP, and CU-CP, based on the second message number (i.e., multicastHFN-AndRefSN) determined by the PDCP COUNT, then sends it to the terminal device via an RRC message.

[0015] In one possible implementation, the method further includes: CU-UP sending a second message number to CU-CP, the second message number being determined based on the PDCP COUNT of the multicast message; and sending the second message number to the terminal device, including: CU-CP sending the second message number to the terminal device.

[0016] This can be understood as follows: CU-UP can determine the second message number (multicastHFN-AndRefSN) based on the PDCP COUNT of the multicast message, and then send the second message number (multicastHFN-AndRefSN) to CU-CP; in this way, CU-CP can directly send the second message number to the terminal device through RRC messages.

[0017] Secondly, embodiments of this application provide a communication method applied to a terminal device. The method includes: sending a second request to a core network device, the second request being used to request joining a first multicast group, the first multicast group being a multicast group that the access network device has not established; receiving a first message number from the access network device, the first message number being a temporary message number indicated by the access network device for the first multicast group; joining the first multicast group based on the first message number; receiving a second message number from the access network device, the second message number being determined by the access network device based on multicast messages of the first multicast group; and rejoining the first multicast group based on the second message number.

[0018] In the embodiments of this application, the beneficial effects of possible implementations of the second aspect can be referred to the beneficial effects of possible implementations of the first aspect, and will not be repeated here.

[0019] In one possible implementation, after rejoining the first multicast group based on the second message number, the method further includes: receiving multicast messages from the access network device for the first multicast group.

[0020] In one possible implementation, receiving a first message number from an access network device includes: receiving a first message from the access network device, the first message indicating permission to join the first multicast group, the first message including the first message number.

[0021] In one possible implementation, before receiving the second message number from the access network device, the method further includes: receiving a second message from the access network device, the second message indicating exiting the first multicast group; exiting the first multicast group; and receiving the second message number from the access network device, including: receiving a third message from the access network device, the third message indicating rejoining the first multicast group, the third message including the second message number.

[0022] In one possible implementation, receiving a second message number from an access network device includes: receiving a fourth message from the access network device, the fourth message indicating exiting and rejoining the first multicast group, the fourth message including the second message number; rejoining the first multicast group based on the second message number includes: exiting the first multicast group and rejoining the first multicast group based on the second message number.

[0023] In one possible implementation, the access network device includes a centralized unit (CU), which includes a CU-control plane (CP); receiving a first message number from the access network device includes receiving a first message number from the CU-CP; receiving a second message number from the access network device includes receiving a second message number from the CU-CP.

[0024] Thirdly, embodiments of this application provide a communication device for executing the methods of the first aspect and the second aspect, or any possible implementation of either the first aspect or the second aspect. The communication device includes modules having the function of executing the methods of the first aspect and the second aspect, or any possible implementation of either the first aspect or the second aspect.

[0025] Fourthly, embodiments of this application provide a communication device including a processing circuit for executing the methods of the first aspect and the second aspect, or any possible implementation of either the first aspect or the second aspect. The processing circuit executes a program stored in a memory, and when the program is executed, the methods described in either the first aspect and the second aspect or any possible implementation thereof are executed.

[0026] In one possible implementation, the memory is located outside the aforementioned communication device.

[0027] In one possible implementation, the memory is located within the aforementioned communication device.

[0028] In this embodiment, the processing circuitry and memory can also be integrated into a single device; that is, the processing circuitry and memory can be integrated together. For example, the communication device can be a chip.

[0029] In one possible implementation, the communication device further includes a transceiver circuit for receiving information (or inputting information) or sending information (or outputting information).

[0030] Fifthly, embodiments of this application provide a communication device, which includes a processing circuit and a transceiver circuit. The processing circuit can be a logic circuit, and the transceiver circuit can be an interface circuit. The logic circuit and the interface circuit are coupled. The interface circuit is used to input and / or output information, and the logic circuit is used to execute the methods in the first aspect and the second aspect, or any possible implementation of the first aspect and the second aspect.

[0031] In a sixth aspect, embodiments of this application provide a chip including a processing circuit and an interface circuit, the processing circuit and the interface circuit being coupled; the interface circuit is used for inputting and / or outputting information, and the processing circuit is used for executing code instructions to cause the method shown in any of the first and second aspects or any possible implementation thereof to be executed.

[0032] In a seventh aspect, embodiments of this application provide a computer-readable storage medium for storing a computer program that, when run on a computer, causes the methods shown in any of the first and second aspects or any possible implementation thereof to be executed.

[0033] Eighthly, embodiments of this application provide a computer program product that, when run on a computer, causes the methods shown in any of the first and second aspects or any possible implementations described above to be executed.

[0034] Ninthly, this application provides a communication system including an access network device and a terminal device. The access network device is used to perform the method shown in the first aspect or any possible implementation thereof, and the terminal device is used to perform the method shown in the second aspect or any possible implementation thereof. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the architecture of a communication system provided in an embodiment of this application;

[0036] Figure 2A This is a schematic diagram of an ORAN system provided in an embodiment of this application;

[0037] Figure 2B This is a diagram illustrating the network element function division and protocol layer structure of an ORAN device provided in an embodiment of this application;

[0038] Figure 3 This is a flowchart illustrating a communication method provided in an embodiment of this application;

[0039] Figure 4A This is a flowchart illustrating another communication method provided in an embodiment of this application;

[0040] Figure 4B This is a flowchart illustrating another communication method provided in an embodiment of this application;

[0041] Figure 5 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0042] Figure 6 This is a schematic diagram of another communication device provided in an embodiment of this application;

[0043] Figure 7 This is a schematic diagram of another communication device provided in an embodiment of this application. Detailed Implementation

[0044] To facilitate understanding of the technical solution of this application, the application will be further described below with reference to the accompanying drawings.

[0045] The terms "first" and "second," etc., used in the specification, claims, and drawings of this application are used only to distinguish different objects and not to describe a specific order. Furthermore, 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 listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0046] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0047] In this application, "at least one (item)" refers to one or more, "more than one" refers to two or more, "at least two (items)" refers to two or three or more, and "and / or" is used to describe the relationship between related objects, indicating that there can be three relationships. For example, "A and / or B" can mean: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. "Or" indicates that there can be two relationships, such as only A exists and only B exists; when A and B are not mutually exclusive, it can also mean that there are three relationships, such as only A exists, only B exists, and both A and B exist simultaneously. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items. For example, at least one (item) of a, b, or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c".

[0048] In this application, "send" and "receive" indicate the direction of signal transmission. For example, "send information to XX" can be understood as the destination of the information being XX, which can include direct transmission via the air interface or indirect transmission via the air interface from other units or modules. "Receive information from YY" can be understood as the source of the information being YY, which can include direct reception from YY via the air interface or indirect reception from YY via the air interface from other units or modules. "Send" can also be understood as the "output" of a chip interface, and "receive" can also be understood as the "input" of a chip interface. In other words, sending and receiving can occur between devices, such as between network devices and terminal devices, or within a device, such as between components, modules, chips, software modules, or hardware modules within the device via buses, traces, or interfaces.

[0049] To better understand the embodiments of this application, the communication system involved in the embodiments of this application will be described below:

[0050] The method provided in this application can be applied to various communication systems, such as: wireless local area network (WLAN) communication systems, wireless fidelity (Wi-Fi) systems, multiple-in multiple-out (MIMO) communication systems, long-term evolution (LTE) systems, internet of things (IoT) systems, narrowband internet of things (NB-IoT) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, fourth-generation (4G) systems, fifth-generation (5G) systems, or new radio (NR) systems, and other future communication systems, such as sixth-generation (6G) systems. Among these, IoT networks may include, but are not limited to, vehicle-to-everything (V2X) networks. The communication methods in V2X systems can be collectively referred to as vehicle-to-everything (V2X), where X can represent anything. For example, V2X can include vehicle-to-vehicle (V2V) communication, vehicle-to-infrastructure (V2I) communication, vehicle-to-pedestrian (V2P) communication, or vehicle-to-network (V2N) communication. The method provided in this application also supports communication systems that integrate multiple wireless technologies. For example, it can be applied to systems that integrate non-terrestrial networks (NTN) with terrestrial mobile communication networks, such as drones, satellite communication systems, and high-altitude platform station (HAPS) communication. Additionally, it can be applied to low-frequency (sub-6GHz) and high-frequency (above 6GHz) communication scenarios. It is understood that the system architecture described in this application is for the purpose of more clearly illustrating the technical solutions of this application and does not constitute a limitation on the technical solutions provided in this application.

[0051] Figure 1 This is a schematic diagram of the architecture of a communication system applicable to embodiments of this application. The communication system includes at least one network device and at least one terminal device. Figure 1 The example uses network equipment and multiple terminal devices. These terminal devices can be cellular phones, smartphones, laptops, handheld communication devices, handheld computing devices, satellite radio devices, GPS devices, personal digital assistants (PDAs), and / or any other suitable devices for communication over wireless communication systems, all of which can connect to the network equipment. These terminal devices are all capable of communicating with the network equipment. Of course, Figure 1 The number of terminal devices and network devices listed is just an example; there could be fewer or more. The following sections will discuss these separately. Figure 1 The terminal equipment and network equipment involved in the communication system are described in detail.

[0052] I. Terminal Equipment

[0053] The terminal device mentioned in the embodiments of this application can be a device with wireless transceiver capabilities. The terminal device can communicate with access network equipment (or access devices or network devices) in a radio access network (RAN). The terminal device can also be referred to as user equipment (UE), access terminal, terminal, subscriber unit, user station, mobile station, remote station, remote terminal, mobile device, user terminal, user agent, or user device, etc. In one possible implementation, the terminal device can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; or it can be deployed on water, including ships; or it can be deployed in the air, such as on airplanes, balloons, or satellites. In another possible implementation, the terminal device can be a handheld device with wireless communication capabilities, vehicle-mounted device, wearable device, sensor, terminal in the Internet of Things, terminal in the Internet of Vehicles, drone, 5G network, or any form of terminal device in future networks, etc., and this application embodiment does not limit this. In another possible implementation, the terminal device can also be a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in autonomous driving, a wireless terminal in telemedicine, a wireless terminal in a smart grid, a wireless terminal in a smart city, or a wireless terminal in a smart home, etc.

[0054] In this application embodiment, the device for implementing the functions of the terminal device can be the terminal device itself; it can also be a device capable of supporting the terminal device in implementing the functions, such as a chip system. The device can be installed in the terminal device or used in conjunction with the terminal device. In this application embodiment, the chip system can be composed of chips or can include chips and other discrete devices. For ease of description, when examples are mentioned below, the technical solutions provided in this application embodiment are described using the UE as an example to illustrate the device for implementing the functions of the terminal device.

[0055] II. Network Equipment (Access Network Equipment)

[0056] A network device can be a device deployed in a radio access network to provide wireless communication services to terminal devices. This network device can also be called an access network device, access equipment, RAN node, or RAN equipment, etc. For example, a network device can be a base station, an evolved NodeB (eNodeB), a next-generation NodeB (gNB), a next-generation evolved NodeB (ng-eNB), or a network device in 6G communication, etc. A network device can be any device with wireless transceiver capabilities, including but not limited to the base stations mentioned above (including base stations deployed on satellites). This network device can also be a device with base station functionality in 6G. As an example, this network device can be an access node, wireless relay node, or wireless backhaul node in a wireless-fidelity (Wi-Fi) system. As another example, this network device can be a wireless controller in a cloud radio access network (CRAN) scenario. As yet another example, this network device can be a wearable device or in-vehicle device capable of providing wireless communication services, etc. As another example, the network device can also be a small station, a transmission reception point (TRP) (or a transmission point), etc. The network device can also be a master station, a secondary station, a motor slide retainer (MSR) node, a home base station, an access point (AP), a baseband unit (BBU), a remote radio unit (RRU), an active antenna unit (AAU), a remote radio head (RRH), a central unit (CU), a distributed unit (DU), a radio unit (RU), a positioning node, etc. In systems using different wireless access technologies, the names of devices with network device functions may vary; these will not be listed individually in the embodiments of this application.

[0057] Network devices can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile network device, and one or more cells can move according to the location of the mobile network device. In other examples, a helicopter or drone can be configured to be used as a device to communicate with another network device.

[0058] In some network device deployments, network devices can include centralized units (CUs) and distributed units (DUs). For example, some protocol layer functions of the network device may be centrally controlled by the CU, while the remaining partial or complete protocol layer functions may be distributed across the DU, which is then centrally controlled by the CU. In other network device deployments, the CU can be divided into CU-control plane (CP) and CU-user plane (UP). In still other deployments, the network device can also be an open radio access network (ORAN / O-RAN) architecture. When the network device is in an ORAN architecture, it can be a functional entity or module within the ORAN, such as a combination of one or more of the following: CU, DU, or RU. In an ORAN system, the CU can also be called an open (O)-CU, the DU can be called an O-DU, the CU-CP can be called an O-CU-CP, and the CU-UP can be called an O-CU-UP, etc. The network device deployment methods listed herein are merely examples. As standard technologies evolve, network devices may have other deployment forms, and this application does not limit them.

[0059] In some deployments, multiple RAN nodes collaborate to assist terminals in achieving wireless access, with different RAN nodes each implementing a portion of the access network's functions. For example, a RAN node can be a CU, DU, CU-CP, CU-UP, or RU, etc. CUs and DUs can be configured separately or included in the same network element, such as a baseband unit (BBU). A radio unit (RU) can be included in radio frequency equipment or radio frequency units, such as an RRU, AAU, or RRH.

[0060] RAN nodes can support one or more types of fronthaul interfaces, each corresponding to a DU and RU with different functions. If the fronthaul interface between the DU and RU is a common public radio interface (CPRI), the DU is configured to implement one or more baseband functions, and the RU is configured to implement one or more radio frequency functions. If the fronthaul interface between the DU and RU is another type of interface, relative to CPRI, some downlink and / or uplink baseband functions, such as, for downlink, precoding, digital beamforming (BF), or one or more of inverse fast Fourier transform (IFFT) / cyclic prefix addition (CP), are moved from the DU to the RU; and for uplink, digital beamforming (BF), or one or more of fast Fourier transform (FFT) / cyclic prefix removal (CP), are moved from the DU to the RU. In one possible implementation, the interface can be an enhanced common public radio interface (eCPRI). Under the eCPRI architecture, the segmentation between DU and RU differs, corresponding to different categories (Cat) of eCPRI, such as eCPRI Cat A, B, C, D, E, F.

[0061] Taking eCPRI Cat A as an example, for downlink transmission, the DU is configured to implement one or more functions preceding and following layer mapping (i.e., coding, rate matching, scrambling, modulation, and layer mapping), while other functions following layer mapping (e.g., resource element (RE) mapping, digital beamforming (BF), or one or more functions following inverse fast Fourier transform (IFFT) / cyclic prefix (CP) addition) are moved to the RU. For uplink transmission, the DU is configured to implement one or more functions preceding and following de-mapping (i.e., decoding, rate matching de-mapping, descrambling, demodulation, inverse discrete Fourier transform (IDFT), channel equalization, and de-RE mapping), while other functions following de-mapping (e.g., digital BF or fast Fourier transform (FFT) / CP removal) are moved to the RU. It is understandable that the functional descriptions of the DU and RU corresponding to various types of eCPRI can be found in the eCPRI protocol, and will not be elaborated here.

[0062] In one possible design, the processing unit in the BBU used to implement baseband functions is called the baseband high (BBH) unit, and the processing unit in the RRU / AAU / RRH used to implement baseband functions is called the baseband low (BBL) unit.

[0063] 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. 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 modules and hardware modules.

[0064] In particular, Figure 2A This is a schematic diagram of an ORAN system provided in an embodiment of this application. Figure 2AAs shown, network devices are also called access network devices. Access network devices (RAN, such as eNB, gNB, or next-generation access network devices) communicate with the core network (CN) via a backhaul link and with user equipment (UE) via an air interface.

[0065] Specifically, the baseband unit (BBU) in the access network equipment communicates with the core network via a backhaul link, and the radio frequency unit (RU) in the access network equipment communicates with at least one UE via an air interface. The BBU communicates with at least one RU via a fronthaul link. The BBU and RU may or may not be co-located.

[0066] The BBU includes at least one control unit (CU) and at least one distributed unit (DU), which can communicate via at least one midhaul link.

[0067] Figure 2B This application provides a network element function partitioning and protocol layer structure diagram for an ORAN device. 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 is connected 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) is connected to the DU (e.g., the RLC layer and lower layers) through interfaces, which may be interfaces such as F1 interfaces. 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, and in some examples, the signaling procedures of F1 are defined. The F1 interface supports the control plane F1-C and the user plane F1-U.

[0068] In some examples, the CU can be split into CU-CP and CU-UP. 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) elements, such as the access and mobility management function (AMF) in a 5G system. The AMF element is responsible for mobility management in the mobile network, such as terminal device location updates, terminal device registration with the network, and terminal device 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 UPF (User Plane Function) in a 5G system, are responsible for data forwarding and receiving in terminal devices. 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.

[0069] 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 PHY layer processing, such as forward error correction (FEC) encoding and decoding, scrambling, modulation, and demodulation.

[0070] 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 3rd generation partnership project (3GPP) transmission reception point (TRP) or remote radio head (RRH) or other similar entities. In some examples, the Low-PHY includes portions of the PHY processing, such as fast fourier transform (FFT), inverse fast fourier transform (IFFT), digital beamforming, and filtering. The RU communicates with one or more UEs via a radio link.

[0071] 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.

[0072] 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.

[0073] In this application embodiment, the device for implementing the function of the network device can be the network device itself; it can also be a device capable of supporting the network device in implementing the function, such as a chip system. The device can be installed in the network device or used in conjunction with the network device. For ease of description, when specific examples are mentioned below, the technical solution provided in this application embodiment will be described using a base station as an example.

[0074] Network devices and / or terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can also be deployed in the air on airplanes, balloons, and satellites. This application does not limit the scenario in which the network devices and terminal devices are located. Furthermore, terminal devices and network devices can be hardware devices, or software functions running on dedicated hardware or general-purpose hardware, such as virtualization functions instantiated on a platform (e.g., a cloud platform), or entities that include dedicated or general-purpose hardware devices and software functions. This application does not limit the specific form of the terminal devices and network devices.

[0075] It should be noted that the network application architecture and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of network application architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0076] To facilitate understanding of the solutions provided in the embodiments of this application, the relevant concepts involved in the embodiments of this application are introduced below:

[0077] 1. Packet Data Convergence Protocol (PDCP) and Hyperframe Number (HFN)

[0078] In NR systems, the main functions of the PDCP protocol include compression, encryption, and integrity protection. Compression reduces data packets, thereby decreasing transmission latency and network congestion. Encryption protects transmitted data from theft or tampering. Integrity protection involves checking and verifying data during transmission to ensure that data packets are free from errors or loss.

[0079] The HFN plays a crucial role in the PDCP layer, especially in handling packet sequence numbers. It ensures the correct ordering and transmission of packets, preventing duplicates or loss. When the receiver's HFN lags behind the target terminal, specific methods are needed to restore synchronization to ensure correct data reception and processing.

[0080] In addition, PDCP associates a counter (COUNT) with each service data unit (SDU). The PDCPCOUNT consists of the PDCP sequence number (SN) and HFN, and is used to identify lost SDUs and count retransmission requests.

[0081] 2. Multicast / broadcast service (MBS)

[0082] Multicast Broadcast Groups (MBS) transmit data from one data source (e.g., a base station) to multiple target terminals, enabling resource sharing across the network (including core and access networks) and improving resource utilization, especially air interface resources. Currently, in the 3GPP standard, when a terminal device requests to join a new radio (NR) MBS multicast group, the base station needs to include the multicast message number (multicastHFN-AndRefSN) in the RRC message to notify the terminal device. The terminal device uses multicastHFN-AndRefSN to initialize the PDCP receive window for the multicast bearer and determine the PDCPHFN. In other words, when a terminal device requests to join an NR MBS multicast group, the base station needs to know which number the current multicast session is sent to; otherwise, the base station cannot send the multicast message number to the terminal device when it requests to join the NR MBS multicast group, resulting in the terminal device failing to join the multicast group.

[0083] For example, terminal device 1 receives multicast service A under base station 1, while no terminal device has ever joined multicast service A under base station 2. Terminal device 1 moves from base station 1 to base station 2 and applies to join multicast service A under base station 2. Since base station 2 has never received multicast service A packets from the core network, base station 2 does not know which packet number multicast service A is currently being sent to, and therefore cannot notify terminal device 1 at the air interface which packet number to start receiving from in the PDCP receive window, resulting in terminal device 1's failure to join the multicast group. Therefore, ensuring that terminal devices successfully join the multicast group is a problem that urgently needs to be solved.

[0084] Therefore, in order to ensure that terminal devices can successfully join multicast groups, this application provides a communication method and a communication device. The communication method and communication device provided in the embodiments of this application will be further described in detail below.

[0085] Figure 3 This is a flowchart illustrating a communication method provided in an embodiment of this application. For example... Figure 3 As shown, the communication method includes the following steps S301 to S307. Figure 3 The method shown can be implemented by the core network equipment, access network equipment, and terminal equipment mentioned above. Alternatively, Figure 3 The device that performs the method shown can be a chip in a core network device, a chip in an access network device, or a chip in a terminal device; however, this application does not limit the implementation of such a device. Figure 3 The method will be explained using core network equipment, access network equipment, and terminal equipment as the implementing entities.

[0086] S301. The terminal device sends a second request to the core network device, the second request being for requesting to join the first multicast group. Accordingly, the core network device receives the second request from the terminal device.

[0087] S302. The core network device sends a first request to the access network device, which requests the terminal device to join the first multicast group. Accordingly, the access network device receives the first request from the core network device.

[0088] S303. The access network device sends a first message number to the terminal device. This first message number is a temporary message number indicated by the access network device for the first multicast group. Correspondingly, the terminal device receives the first message number from the access network device.

[0089] In one possible implementation, the access network device sending the first message number to the terminal device can be achieved by the access network device sending a first message to the terminal device, the first message indicating permission to join the first multicast group, the first message including the first message number. Correspondingly, the terminal device receives the first message from the access network device.

[0090] Here, the first message can be the first RRC message. This can be understood as the access network device instructing the terminal device to join the first multicast group via the first RRC message and notifying the terminal device of the first message number.

[0091] S304. The terminal device joins the first multicast group based on the first message number.

[0092] S305. The core network device sends the multicast message of the first multicast group to the access network device. Correspondingly, the access network device receives the multicast message of the first multicast group from the core network device.

[0093] S306. The access network device sends a second message number to the terminal device, which is determined based on the multicast message. Accordingly, the terminal device receives the second message number from the access network device.

[0094] S307. The terminal device rejoins the first multicast group based on the second message number.

[0095] In this embodiment, the terminal device can request to join a multicast session from the network. Specifically, the terminal device can send a second request to the core network device to request to join the first multicast group. After receiving the second request from the terminal device, the core network device can further send a first request (i.e., an N2 message request) to the access network device to request the terminal device to join the first multicast group. Here, the terminal device can be in a connected state or an idle state; no restriction is imposed.

[0096] After receiving the first request from the core network device, the access network device determines that the first multicast group is a multicast group that the access network device has not established before. At this time, the terminal device applying to join the first multicast group can be understood as the first terminal device to apply to join the first multicast group; or it can be other terminal devices that apply to join the first multicast group after the first terminal device applies to join the first multicast group, but before the access network device receives the multicast message of the first multicast group sent by the core network device.

[0097] Since the access network device does not yet know which specific message number the first multicast group has been sent to, in order to ensure that the terminal device can successfully join the first multicast group, the access network device can first allow the terminal device to join the first multicast group through a first RRC message (i.e., the first message), and notify the terminal device of a temporary message number, namely the first message number. This first message number is determined by the access network device arbitrarily assigning a PDCPCOUNT for the first multicast group. After receiving the first message number, the terminal device can join the first multicast group based on that first message number. The PDCP COUNT consists of an HFN and a PDCP SN.

[0098] After receiving the multicast message for the first multicast group from the core network device, the access network device can determine the current actual PDCP COUNT based on the multicast message of the first multicast group, thus clarifying which message number has been sent, i.e., the second message number (which can also be called the official message number, i.e., multicastHFN-AndRefSN). Then, the access network device can send the second message number to the terminal device, enabling the terminal device to rejoin the first multicast group based on the second message number.

[0099] In other words, in a scenario where a terminal device requests to join the first multicast group but the access network device has not yet established the first multicast group, the terminal device can first join the first multicast group based on a temporary first message number. At this time, the small amount of data received will not affect the overall service transmission. After the access network device receives the multicast message of the first multicast group sent by the core network device, the access network device determines the formal second message number based on the multicast message of the first multicast group. The terminal device then rejoins the first multicast group based on the second message number. This ensures that the terminal device can successfully join the first multicast group, while also improving the independence of the access network device in solving problems and reducing the cooperation of other devices.

[0100] In one possible implementation, the access network device can send the second message number to the terminal device in either of the following two ways:

[0101] Method 1: The access network device instructs the terminal device to leave the first multicast group via a second message, and then instructs the terminal device to rejoin the first multicast group via a third message.

[0102] Specifically, before the access network device sends the second message number to the terminal device, the access network device sends a second message to the terminal device, which indicates that it is leaving the first multicast group. Accordingly, the terminal device receives the second message from the access network device and then leaves the first multicast group. Further, the access network device sends a third message to the terminal device, which indicates that it is rejoining the first multicast group. This third message includes the second message number. Accordingly, the terminal device receives the third message from the access network device and can then rejoin the first multicast group based on the second message number.

[0103] This can be understood as follows: the access network device can use the second RRC message (i.e., the second message) to indicate that the terminal devices that have joined the first multicast group have left in batches, and then use the third RRC message (i.e., the third message) to indicate that the terminal devices that have left in batches have rejoined the first multicast group based on the second message number.

[0104] Method 2: The access network device instructs the terminal device to exit and rejoin the first multicast group via the fourth message.

[0105] Specifically, the access network device sends a fourth message to the terminal device, which indicates whether to leave and rejoin the first multicast group. This fourth message includes a second message number. Accordingly, the terminal device receives the fourth message from the access network device, then leaves the first multicast group and rejoins it based on the second message number.

[0106] This can be understood as the access network device being able to directly instruct terminal devices that have joined the first multicast group to leave in batches via the fourth RRC message (i.e., the fourth message), and then rejoin the first multicast group based on the second message number.

[0107] In one possible implementation, after receiving the multicast message of the first multicast group from the core network device, the access network device may store the multicast message of the first multicast group; after sending the second message number to the terminal device, the access network device then sends the multicast message of the first multicast group to the terminal device. Accordingly, the terminal device receives the multicast message of the first multicast group from the access network device.

[0108] This can be understood as follows: after the access network device receives the multicast message of the first multicast group from the core network device, it stores it first. Only after the access network device sends the second message number to the terminal device, and the terminal device rejoins the first multicast group based on the second message number, will the access network device send the multicast message of the first multicast group to the terminal device, thereby improving the reliability of data transmission.

[0109] In one possible implementation, for an ORAN system, the access network equipment includes a CU, and the CU includes a CU-CP and a CU-UP; then, in the ORAN system, the specific implementation of the above steps S301 to S307 can adopt any one of the following two methods:

[0110] Method 1: such as Figure 4A As shown.

[0111] s11. The terminal device sends a second request to the core network device, which requests to join the first multicast group. Accordingly, the core network device receives the second request from the terminal device.

[0112] s12. The core network device sends a first request to the CU-CP, which requests the terminal device to join the first multicast group. Accordingly, the CU-CP receives the first request from the core network device.

[0113] s13. The CU-CP sends a first message number to the terminal device. This first message number is a temporary message number indicated by the access network device for the first multicast group. Accordingly, the terminal device receives the first message number from the CU-CP.

[0114] s14. The terminal device joins the first multicast group based on the first message number.

[0115] s15. The core network device sends the multicast message of the first multicast group to the CU-UP. Correspondingly, the CU-UP receives the multicast message of the first multicast group from the core network device.

[0116] Optionally, CU-UP can store multicast messages for the first multicast group.

[0117] s16. CU-UP sends the Packet Data Convergence Protocol Counter (PDCP COUNT) for the multicast message to CU-CP. Correspondingly, CU-CP receives the PDCP COUNT for the multicast message from CU-UP.

[0118] s17. The CU-CP sends a second message number to the terminal device, which is determined based on the PDCP COUNT of the multicast message. Accordingly, the terminal device receives the second message number from the CU-CP.

[0119] This can be understood as follows: CU-UP simply sends the PDCP COUNT of the multicast message to CU-CP, and CU-CP, based on the second message number (i.e., multicastHFN-AndRefSN) determined by the PDCP COUNT, then sends it to the terminal device via an RRC message.

[0120] s18. The terminal device rejoins the first multicast group based on the second message number.

[0121] Optionally, after the terminal device rejoins the first multicast group based on the second message number, CU-UP can send the previously stored multicast messages of the first multicast group to the terminal device.

[0122] Method 2: such as Figure 4B As shown.

[0123] s21. The terminal device sends a second request to the core network device, which requests to join the first multicast group. Accordingly, the core network device receives the second request from the terminal device.

[0124] s22. The core network device sends a first request to the CU-CP, which requests the terminal device to join the first multicast group. Accordingly, the CU-CP receives the first request from the core network device.

[0125] s23. The CU-CP sends a first message number to the terminal device. This first message number is a temporary message number indicated by the access network device for the first multicast group. Accordingly, the terminal device receives the first message number from the CU-CP.

[0126] s24. The terminal device joins the first multicast group based on the first message number.

[0127] s25. The core network device sends the multicast message of the first multicast group to the CU-UP. Correspondingly, the CU-UP receives the multicast message of the first multicast group from the core network device.

[0128] Optionally, CU-UP can store multicast messages for the first multicast group.

[0129] s26. CU-UP sends a second message number to CU-CP, which is determined based on the PDCPCOUNT of the multicast message. Correspondingly, CU-CP receives the second message number from CU-UP.

[0130] s27. The CU-CP sends the second message number to the terminal device. Accordingly, the terminal device receives the second message number from the CU-CP.

[0131] This can be understood as follows: CU-UP can determine the second message number (multicastHFN-AndRefSN) based on the PDCP COUNT of the multicast message, and then send the second message number (multicastHFN-AndRefSN) to CU-CP; in this way, CU-CP can directly send the second message number to the terminal device through RRC messages.

[0132] s28. The terminal device rejoins the first multicast group based on the second message number.

[0133] Optionally, after the terminal device rejoins the first multicast group based on the second message number, CU-UP can send the previously stored multicast messages of the first multicast group to the terminal device.

[0134] It can be seen that, based on Figure 3 The described method allows a terminal device to join a first multicast group when the access network device has not yet established such a group. The terminal device can initially join the first multicast group based on a temporary first message number. The small amount of data received at this stage will not affect the overall service transmission. Once the access network device receives the multicast message for the first multicast group from the core network device, it determines the official second message number based on this message. The terminal device then rejoins the first multicast group based on this second message number. This approach ensures successful joining of the first multicast group while also improving the access network device's independence in resolving the issue and reducing the need for cooperation from other devices.

[0135] The apparatus provided in the embodiments of this application will be described below.

[0136] This application divides the device into functional modules according to the above method embodiments. For example, each function can be divided into its own functional modules, or two or more functions can be integrated into one processing module. The integrated modules can be implemented in hardware or as software functional modules. It should be noted that the module division in this application is illustrative and only represents one logical functional division; other division methods may be used in actual implementation. The following will combine... Figures 5 to 7 The apparatus of the embodiments of this application is described in detail.

[0137] Figure 5 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application, such as... Figure 5 As shown, the communication device includes a processing module 501 and a transceiver module 502. The transceiver module 502 can implement corresponding communication functions, and the processing module 501 is used to implement corresponding processing functions. The transceiver module 502 can also be referred to as an interface, communication interface, or communication module, etc.

[0138] In some embodiments of this application, the communication device can be used to perform the actions performed by the access network device in the above method embodiments. In this case, the communication device can be the access network device itself or a chip or functional module configurable within the access network device. The transceiver module 502 is used to perform transceiver-related operations of the access network device in the above method embodiments, and the processing module 501 is used to perform processing-related operations of the access network device in the above method embodiments.

[0139] For example, the transceiver module 502 can be used to receive a first request from the core network device, the first request being used to request the terminal device to join a first multicast group, the first multicast group being a multicast group that the access network device has not established.

[0140] The transceiver module 502 can also be used to send a first message number to the terminal device, which is a temporary message number indicated by the access network device for the first multicast group.

[0141] The transceiver module 502 can also be used to receive multicast messages from the first multicast group from the core network equipment;

[0142] The transceiver module 502 can also be used to send a second message number to the terminal device, which is determined based on the multicast message.

[0143] As an example, after receiving the multicast message of the first multicast group from the core network device, the processing module 501 can be used to: store the multicast message; after sending the second message number to the terminal device, the transceiver module 502 can also be used to: send the multicast message to the terminal device.

[0144] As another example, when sending the first message number to the terminal device, the transceiver module 502 can be specifically used to: send a first message to the terminal device, the first message being used to indicate permission to join the first multicast group, the first message including the first message number.

[0145] As another example, before sending the second message number to the terminal device, the transceiver module 502 can also be used to: send a second message to the terminal device, the second message being used to indicate leaving the first multicast group; when sending the second message number to the terminal device, the transceiver module 502 can specifically be used to: send a third message to the terminal device, the third message being used to indicate rejoining the first multicast group, the third message including the second message number.

[0146] As another example, when sending the second message number to the terminal device, the transceiver module 502 can specifically be used to send a fourth message to the terminal device, the fourth message being used to indicate exiting and rejoining the first multicast group, the fourth message including the second message number.

[0147] As another example, the access network device includes a CU, which includes a CU-CP and a CU-UP; the transceiver module 502, when receiving a first request from the core network device, can be specifically used for: the CU-CP receiving the first request from the core network device; the transceiver module 502, when sending a first message number to the terminal device, can be specifically used for: the CU-CP sending the first message number to the terminal device; the transceiver module 502, when receiving multicast messages from the first multicast group from the core network device, can be specifically used for: the CU-UP receiving the multicast messages from the first multicast group from the core network device.

[0148] As another example, the transceiver module 502 can also be used to: send the packet data aggregation protocol counter (PDCP COUNT) of the multicast message to the CU-UP; when sending the second message number to the terminal device, the transceiver module 502 can specifically be used to: send the second message number to the terminal device, the second message number being determined based on the PDCP COUNT of the multicast message.

[0149] As another example, the transceiver module 502 can also be used to: send a second message number from the CU-UP to the CU-CP, the second message number being determined based on the PDCP COUNT of the multicast message; when sending the second message number to the terminal device, the transceiver module 502 can specifically be used to: send the second message number from the CU-CP to the terminal device.

[0150] For example, the transceiver module 502 may include a radio frequency module, an antenna module, etc. For example, the transceiver module 502 may include a pin module, etc.

[0151] Reuse Figure 5 In other embodiments of this application, the communication device can be used to perform the actions performed by the terminal device in the above method embodiments. In this case, the communication device can be the terminal device itself or a chip or functional module configurable within the terminal device. The transceiver module 502 is used to perform transceiver-related operations of the terminal device in the above method embodiments, and the processing module 501 is used to perform processing-related operations of the terminal device in the above method embodiments.

[0152] For example, the transceiver module 502 can be used to send a second request to the core network device, the second request being used to request to join the first multicast group, the first multicast group being a multicast group that the access network device has not established;

[0153] The transceiver module 502 can also be used to receive a first message number from the access network device, which is a temporary message number indicated by the access network device for the first multicast group.

[0154] Processing module 501 can be used to join the first multicast group based on the first message number;

[0155] The transceiver module 502 can also be used to receive a second message number from the access network device, which is determined by the access network device based on the multicast message of the first multicast group;

[0156] The processing module 501 can also be used to rejoin the first multicast group based on the second message number.

[0157] As an example, after rejoining the first multicast group based on the second message number, the transceiver module 502 can also be used to: receive multicast messages from the first multicast group from the access network device.

[0158] As another example, when receiving a first message number from an access network device, the transceiver module 502 may specifically be used to: receive a first message from the access network device, the first message indicating permission to join the first multicast group, the first message including the first message number.

[0159] As another example, before receiving the second message number from the access network device, the transceiver module 502 can also be used to: receive a second message from the access network device, the second message indicating exit from the first multicast group; the processing module 501 can be used to: exit the first multicast group; when receiving the second message number from the access network device, the transceiver module 502 can specifically be used to: receive a third message from the access network device, the third message indicating rejoining the first multicast group, the third message including the second message number.

[0160] As another example, when receiving a second message number from an access network device, the transceiver module 502 may specifically be used to: receive a fourth message from the access network device, the fourth message indicating exiting and rejoining the first multicast group, the fourth message including the second message number; when rejoining the first multicast group based on the second message number, the processing module 501 may specifically be used to: exit the first multicast group and rejoin the first multicast group based on the second message number.

[0161] As another example, the access network device includes a CU, and the CU includes a CU-CP; the transceiver module 502, when receiving a first message number from the access network device, can be specifically used to: receive a first message number from the CU-CP; the transceiver module 502, when receiving a second message number from the access network device, can be specifically used to: receive a second message number from the CU-CP.

[0162] For example, the transceiver module 502 may include a radio frequency module, an antenna module, etc. For example, the transceiver module 502 may include a pin module, etc.

[0163] Optionally, in the above embodiments, the communication device may further include a storage module, which can be used to store instructions and / or data. The processing module 501 can read the instructions and / or data in the storage module to enable the device to implement the aforementioned method embodiments. For example, the storage module may also store the multicast messages, first message number, second message number, etc., of the first multicast group shown above.

[0164] For details regarding the terms or steps such as MBS multicast group, PDCP, HFN, and message number in each sub-block in the above embodiments, please refer to the description in the above method embodiments. They will not be described in detail here.

[0165] The specific descriptions of the transceiver module and processing module shown in the above embodiments are merely examples. For the specific functions or execution steps of the transceiver module and processing module, please refer to the above method embodiments, which will not be described in detail here.

[0166] The apparatus of the embodiments of this application has been described above. The possible product forms of the described apparatus are described below. Any device possessing the above-described features... Figure 5 Any form of product that incorporates the functionality of the described device falls within the protection scope of the embodiments of this application. The following description is merely illustrative and does not limit the product form of the device in the embodiments of this application to this specific example.

[0167] In one possible implementation, Figure 5In the communication device shown, the processing module 501 can be one or more processing circuits, and the transceiver module 502 can be a transceiver circuit, or the transceiver module 502 can also be a transmitting module and a receiving module. The transmitting module can be a transmitting circuit, and the receiving module can be a receiving circuit, which are integrated into one device, such as a transceiver circuit. In the embodiments of this application, the processing circuit and the transceiver circuit can be coupled, etc., and the connection method of the processing circuit and the transceiver circuit is not limited in the embodiments of this application. In the process of performing the above method, the process of sending information in the above method can be the process of the processing circuit outputting the above information. When outputting the above information, the processing circuit outputs the above information to the transceiver circuit so that the transceiver circuit can transmit (or output). After the above information is output by the processing circuit, it may need to undergo other processing before reaching the transceiver circuit. Similarly, the process of receiving information in the above method can be the process of the processing circuit receiving the input above information. When the processing circuit receives the input information, the transceiver circuit receives the above information and inputs it into the processing circuit. Furthermore, after the transceiver circuit receives the aforementioned information, the information may need to undergo further processing before being input into the processing circuit.

[0168] Figure 6 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Figure 6 As shown, the communication device 600 includes one or more processing circuits 620 and transceiver circuits 610.

[0169] In some embodiments of this application, the communication device can be used to perform the steps, methods, or functions performed by the access network device described above. For example, the processing circuit 620 can be used to perform, for example... Figure 5 The transceiver circuit 610 can be used to perform the functions or steps implemented by the processing module 501 shown. Figure 5 The transceiver module 502 shown illustrates the functions or steps implemented by this module. For detailed descriptions of the processing circuit 620 and the transceiver circuit 610, please refer to [link / reference needed]. Figure 5 Alternatively, the method embodiments shown above will not be described in detail here.

[0170] In other embodiments of this application, the apparatus is used to perform the steps, methods, or functions performed by the terminal device described above. For example, the processing circuit 620 may be used to perform, for example... Figure 5 The transceiver circuit 610 can be used to perform the functions or steps implemented by the processing module 501 shown. Figure 5 The transceiver module 502 shown illustrates the functions or steps implemented by this module. For detailed descriptions of the processing circuit 620 and the transceiver circuit 610, please refer to [link / reference needed]. Figure 5 Alternatively, the method embodiments shown above will not be described in detail here.

[0171] For example, the processing circuitry may be one or more processors, or all or part of the circuitry within one or more processors. The transceiver circuitry may be a transceiver, an input / output circuit, or an interface circuit, etc.

[0172] For example, in Figure 6 In various implementations of the illustrated apparatus, the transceiver circuitry may include a receiver for performing a receiving function (or operation) and a transmitter for performing a transmitting function (or operation). The transceiver circuitry is also used for communicating with other devices / appliances via a transmission medium.

[0173] Optionally, the communication device 600 may further include one or more memories 630 for storing program instructions and / or data. The memories 630 are coupled to the processing circuitry 620. The coupling in this embodiment is an indirect coupling or communication connection between devices, units, or modules, and can be electrical, mechanical, or other forms, used for information exchange between devices, units, or modules. The processing circuitry 620 may operate in conjunction with the memories 630. The processing circuitry 620 may execute the program instructions stored in the memories 630. Optionally, at least one of the aforementioned memories may be included in the processing circuitry.

[0174] This application embodiment does not limit the specific connection medium between the transceiver circuit 610, the processing circuit 620, and the memory 630. This application embodiment... Figure 6 The memory 630, processing circuit 620, and transceiver circuit 610 are connected via a bus 640. Figure 6 The connections between other components are shown in bold and are for illustrative purposes only, not as limiting information. The bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, Figure 6 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0175] In the embodiments of this application, the processing circuit may be a general-purpose processing circuit, a digital signal processing circuit, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc., and can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processing circuit may be a microprocessor circuit or any conventional processing circuit, etc. The steps of the methods disclosed in the embodiments of this application can be directly manifested as being executed by a hardware processing circuit, or being executed by a combination of hardware and software modules in the processing circuit, etc.

[0176] In this application embodiment, the memory may include, but is not limited to, non-volatile memory such as hard disk drive (HDD) or solid-state drive (SSD), random access memory (RAM), erasable programmable read-only memory (EPROM), read-only memory (ROM), or compact disc read-only memory (CD-ROM), etc. Memory is any storage medium capable of carrying or storing program code having instruction or data structure forms, and capable of being read and / or written by a computer (such as the device shown in this application), but is not limited to this. The memory in this application embodiment may also be a circuit or any other device capable of implementing storage functions, used to store program instructions and / or data.

[0177] For example, the processing circuit 620 is mainly used to process communication protocols and communication data, control the entire device, execute software programs, and process the data of the software programs. The memory 630 is mainly used to store software programs and data. The transceiver circuit 610 may include a control circuit and an antenna. The control circuit is mainly used for converting baseband signals to radio frequency signals and processing radio frequency signals. The antenna is mainly used for transmitting and receiving radio frequency signals in the form of electromagnetic waves. Input / output devices, such as touch screens, displays, and keyboards, are mainly used to receive user input data and output data to the user.

[0178] When the device is powered on, the processing circuit 620 can read the software program in the memory 630, interpret and execute the instructions of the software program, and process the data of the software program. When data needs to be transmitted wirelessly, the processing circuit 620 performs baseband processing on the data to be transmitted and outputs the baseband signal to the radio frequency (RF) circuit. The RF circuit then performs RF processing on the baseband signal and transmits the RF signal outward in the form of electromagnetic waves through the antenna. When data is sent to the device, the RF circuit receives the RF signal through the antenna, converts the RF signal into a baseband signal, and outputs the baseband signal to the processing circuit 620. The processing circuit 620 converts the baseband signal into data and processes the data.

[0179] In another implementation, the radio frequency circuit and antenna can be set up independently of the processing circuit that performs baseband processing. For example, in a distributed scenario, the radio frequency circuit and antenna can be arranged remotely, independent of the device.

[0180] The apparatus shown in the embodiments of this application may also have a higher... Figure 6This application does not limit the use of other components or other related elements. The methods performed by the processing circuit and transceiver circuit shown above are merely examples; the specific steps performed by the processing circuit and transceiver circuit can be found in the methods described above.

[0181] In another possible implementation Figure 5 In the illustrated device, the processing module 501 can be one or more logic circuits, and the transceiver module 502 can be an input / output interface, or a communication interface, or an interface circuit, or an interface, etc. Alternatively, the transceiver module 502 can also be a transmitting module and a receiving module. The transmitting module can be an output interface, and the receiving module can be an input interface. The transmitting module and the receiving module are integrated into one module, such as an input / output interface.

[0182] Figure 7 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Figure 7 As shown, Figure 7 The communication device shown includes logic circuit 701 and interface circuit 702. That is, the processing module 501 can be implemented using logic circuit 701, and the transceiver module 502 can be implemented using interface circuit 702. The logic circuit 701 can be a chip, processing circuit, integrated circuit, or system-on-chip (SoC) chip, etc., and the interface circuit 702 can be a communication interface, input / output interface, pins, etc. For example, Figure 7 The above-mentioned communication device is used as an example of a chip, which includes a logic circuit 701 and an interface circuit 702.

[0183] In this embodiment, the logic circuit and the interface can also be coupled to each other. The specific connection method between the logic circuit and the interface is not limited in this embodiment. For example, the logic circuit 701 can be used to perform... Figure 5 The interface circuit 702 can be used to execute the functions or steps implemented by the processing module 501 shown. Figure 5 The transceiver module 502 shown illustrates the functions or steps implemented by this module. For detailed explanations of the logic circuit 701 and the interface circuit 702, please refer to [link / reference needed]. Figure 5 Alternatively, the method embodiments shown above will not be described in detail here.

[0184] The apparatus shown in the embodiments of this application can be implemented in hardware or software, and the embodiments of this application do not limit this.

[0185] This application also provides a communication system, which includes an access network device and a terminal device, which can be used to perform the methods in any of the foregoing embodiments. Optionally, the communication system further includes a core network device, which can be used to perform the methods in any of the foregoing embodiments.

[0186] In addition, this application also provides a computer program for implementing the operations and / or processes performed by various devices in the method provided in this application.

[0187] This application also provides a computer-readable storage medium storing computer code that, when executed on a computer, causes the computer to perform the operations and / or processes performed by the various devices in the methods provided in this application.

[0188] This application also provides a computer program product comprising computer code or a computer program that, when run on a computer, causes the operations and / or processes performed by various entities in the method provided in this application to be executed.

[0189] In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the couplings or direct couplings or communication connections shown or discussed may be indirect couplings or communication connections through some interfaces, devices, or modules, or they may be electrical, mechanical, or other forms of connection.

[0190] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected according to actual needs to achieve the technical effects of the solutions provided in the embodiments of this application.

[0191] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0192] If the integrated module is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a readable storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned readable storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0193] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method, characterized in that, Applied to access network equipment, the method includes: Receive a first request from the core network device, the first request being used to request the terminal device to join a first multicast group, the first multicast group being a multicast group that the access network device has not established; Send a first message number to the terminal device, wherein the first message number is a temporary message number indicated by the access network device for the first multicast group; Receive multicast packets from the first multicast group of the core network device; A second message number is sent to the terminal device, the second message number being determined based on the multicast message.

2. The method according to claim 1, characterized in that, After receiving the multicast message from the first multicast group of the core network device, the method further includes: Store the multicast message; After sending the second message number to the terminal device, the method further includes: The multicast message is sent to the terminal device.

3. The method according to claim 1 or 2, characterized in that, Sending the first message number to the terminal device includes: A first message is sent to the terminal device, the first message indicating permission to join the first multicast group, the first message including a first message number.

4. The method according to any one of claims 1-3, characterized in that, Before sending the second message number to the terminal device, the method further includes: Send a second message to the terminal device, the second message being used to indicate exiting the first multicast group; Sending the second message number to the terminal device includes: A third message is sent to the terminal device, the third message being used to instruct the user to rejoin the first multicast group, the third message including a second message number.

5. The method according to any one of claims 1-3, characterized in that, Sending the second message number to the terminal device includes: A fourth message is sent to the terminal device, the fourth message being used to indicate exiting and rejoining the first multicast group, the fourth message including a second message number.

6. The method according to any one of claims 1-5, characterized in that, The access network equipment includes a centralized unit (CU), which includes a CU-control plane (CP) and a CU-user plane (UP). Receiving the first request from the core network device includes: The CU-CP receives a first request from the core network device; Sending the first message number to the terminal device includes: The CU-CP sends a first message number to the terminal device; Receiving multicast packets from the first multicast group of the core network device includes: The CU-UP receives multicast packets from the first multicast group of the core network device.

7. The method according to claim 6, characterized in that, The method further includes: The CU-UP sends the packet data aggregation protocol counter (PDCP COUNT) of the multicast message to the CU-CP; Sending the second message number to the terminal device includes: The CU-CP sends a second message number to the terminal device, the second message number being determined based on the PDCP COUNT of the multicast message.

8. The method according to claim 6, characterized in that, The method further includes: The CU-UP sends a second message number to the CU-CP, the second message number being determined based on the PDCP COUNT of the multicast message; Sending the second message number to the terminal device includes: The CU-CP sends a second message number to the terminal device.

9. A communication method, characterized in that, Applied to a terminal device, the method includes: Send a second request to the core network device. The second request is used to request to join the first multicast group, which is a multicast group that the access network device has not established. Receive a first message number from the access network device, wherein the first message number is a temporary message number indicated by the access network device for the first multicast group; Join the first multicast group based on the first message number; Receive a second message number from the access network device, the second message number being determined by the access network device based on the multicast message of the first multicast group; Rejoin the first multicast group based on the second message number.

10. The method according to claim 9, characterized in that, After rejoining the first multicast group based on the second message number, the method further includes: Receive multicast messages from the first multicast group of the access network device.

11. The method according to claim 9 or 10, characterized in that, Receiving the first message number from the access network device includes: A first message is received from the access network device, the first message indicating permission to join the first multicast group, the first message including a first message number.

12. The method according to any one of claims 9-11, characterized in that, Before receiving the second message number from the access network device, the method further includes: Receive a second message from the access network device, the second message being used to indicate exiting the first multicast group; Exit the first multicast group; The receipt of the second message number from the access network device includes: A third message is received from the access network device, the third message being used to instruct rejoining the first multicast group, the third message including a second message number.

13. The method according to any one of claims 9-11, characterized in that, The receipt of the second message number from the access network device includes: Receive a fourth message from the access network device, the fourth message being used to indicate exiting and rejoining the first multicast group, the fourth message including a second message number; The step of rejoining the first multicast group based on the second message number includes: Exit the first multicast group and rejoin the first multicast group based on the second message number.

14. The method according to any one of claims 9-13, characterized in that, The access network equipment includes a centralized unit (CU), and the CU includes a CU-control plane (CP). Receiving the first message number from the access network device includes: Receive the first message number from the CU-CP; The receipt of the second message number from the access network device includes: Receive the second message number from the CU-CP.

15. A communication device, characterized in that, It includes a module for performing the method as described in any one of claims 1-8, or includes a module for performing the method as described in any one of claims 9-14.

16. A communication device, characterized in that, It includes a processing circuit and a transceiver circuit, the transceiver circuit being used to input and / or output information, and the processing circuit being used to perform the method as described in any one of claims 1-8, or the processing circuit being used to perform the method as described in any one of claims 9-14.

17. A chip, characterized in that, It includes a processing circuit and an interface circuit, the processing circuit and the interface circuit being coupled; the interface circuit is used for inputting and / or outputting information, and the processing circuit is used for executing code instructions to cause the method of any one of claims 1-8 to be executed, or to cause the method of any one of claims 9-14 to be executed.

18. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store a computer program, which, when executed, performs the method as described in any one of claims 1-8, or the method as described in any one of claims 9-14.

19. A computer program product, characterized in that, When the computer program product is executed, the method described in any one of claims 1-8 is executed, or the method described in any one of claims 9-14 is executed.

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