Communication method and apparatus

Abstract

The application provides a communication method and device, the method is applied to a terminal device, the terminal device comprises a first multicast radio bearer (MRB), the first MRB comprises a first packet data convergence protocol (PDCP) entity and a first RLC entity, the first RLC entity uses an acknowledgement mode (AM), and the method comprises the following steps: the terminal device receives first indication information sent by a source node, the first indication information indicates that the receiving window of the first PDCP entity is adjusted when the first PDCP entity is reconstructed; and the terminal device adjusts the receiving window of the first PDCP entity according to the first indication information. According to the application, the terminal device configured with an AM MRB can normally receive multicast service data when switching nodes, data packets are avoided to be lost, the continuity of multicast service and the reliability of multicast transmission mode are improved, and user experience is improved.

Description

Technical Field

[0001] This application relates to the field of communications, and more specifically, to a communication method and apparatus. Background Technology

[0002] Multicast transmission technology refers to the technique of network devices simultaneously sending the same data to multiple terminal devices, i.e., point-to-multipoint transmission. When using multicast technology, multiple terminal devices simultaneously receive the same data while the network device (e.g., a base station) is sending it. Currently, when network devices and terminal devices transmit data using multicast, transmission failures may occur, leading to poor data transmission reliability and service continuity, data corruption, and reduced communication quality and service experience. Summary of the Invention

[0003] This application provides a communication method and apparatus that can improve the adaptability of multicast services and the reliability of multicast propagation methods, thereby increasing communication efficiency.

[0004] A first aspect provides a communication method applied to a terminal device, the terminal device including a first multicast radio bearer (MRB), the first MRB including a first packet data aggregation protocol (PDCP) entity and a first radio link control (RLC) entity, the first RLC entity employing acknowledgment mode (AM), the method comprising:

[0005] The terminal device receives a first indication message sent by the source node, which indicates that the receiving window of the first PDCP entity should be adjusted when reconstructing the first PDCP entity;

[0006] The terminal device adjusts the receiving window of the first PDCP entity according to the first instruction information.

[0007] For example, the source node can be considered as the source cell or the source access network device.

[0008] In this embodiment of the application, when a terminal device with an AM MRB is configured to switch nodes, the receiving window of the PDCP entity corresponding to the AM MRB can be adjusted so that the terminal device can receive multicast service data normally after switching to the target node, avoiding data packet loss, improving the adaptability of multicast services and the reliability of multicast propagation methods, and improving communication efficiency and user experience.

[0009] In conjunction with the first aspect, in some implementations of the first aspect, the first indication information includes second indication information, which indicates that the regional session ID of the target node is inconsistent with the regional session ID of the source node;

[0010] The terminal device adjusts the receiving window of the first PDCP entity according to the first instruction information, including:

[0011] The terminal device initializes the window parameters of the receive window of the first PDCP entity.

[0012] In conjunction with the first aspect, in some implementations of the first aspect, the first indication information includes third indication information, which indicates that the PDCP sequence numbers of the target node and the source node are out of sync;

[0013] The terminal device adjusts the receiving window of the first PDCP entity according to the first instruction information, including:

[0014] The terminal device initializes the window parameters of the receive window of the first PDCP entity.

[0015] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes:

[0016] When the reordering timer is enabled, the terminal device submits the data packets cached by the first PDCP entity.

[0017] In conjunction with the first aspect, in some implementations of the first aspect, the first indication information includes fourth indication information, which is used to indicate the superframe number of the target node;

[0018] The terminal device adjusts the receiving window of the first PDCP entity according to the first instruction information, including:

[0019] The terminal device adjusts the window parameters of the receiving window of the first PDCP entity based on the difference between the superframe number of the target node and the superframe number of the source node.

[0020] In conjunction with the first aspect, in certain implementations of the first aspect, the first indication information is characterized in that the first indication information is included in the first information for indicating the switching node.

[0021] In a second aspect, a communication method is provided, the method comprising: a source node sending a first indication message to a terminal device, the first indication message indicating that the receiving window of the first PDCP entity is adjusted when reconstructing the first packet data aggregation protocol PDCP entity, wherein the terminal device includes a first multicast radio bearer MRB, the first MRB including the first PDCP entity and a first RLC entity, the first RLC entity adopting acknowledgment mode AM, and the first PDCP entity being associated with the first RLC entity.

[0022] In conjunction with the second aspect, in some implementations of the second aspect, before the source node sends the first indication information to the terminal device, the method further includes: the source node sending a handover request information to the target node; the source node receiving the handover request confirmation information, the handover request confirmation information including indication information for instructing adjustment of the receiving window of the first PDCP entity.

[0023] In conjunction with the second aspect, in some implementations of the second aspect, the first indication information includes second indication information, which indicates that the regional session ID of the target node is inconsistent with the regional session ID of the source node.

[0024] In conjunction with the second aspect, in some implementations of the second aspect, the first indication information includes a third indication information, which indicates that the sequence numbers of the target node and the source node are out of sync.

[0025] In conjunction with the second aspect, in some implementations of the second aspect, the first indication information includes a fourth indication information, which indicates the superframe number of the target node.

[0026] In conjunction with the second aspect, in some implementations of the second aspect, the first indication information is included in the first information for indicating the switching node.

[0027] Thirdly, a communication method is provided, comprising: a first access network device receiving third information sent by a terminal device, the third information indicating resources used by the terminal device to receive multicast services or the capability to support receiving multicast services; the first access network device configuring a data radio bearer (DRB) to the terminal device according to the first indication information, the DRB being used to carry unicast services, wherein the third information includes the number of ROHC-Contexts used by the terminal device to receive the multicast services and / or the number of EHC-Contexts used by the terminal device to receive the multicast services and / or the number of multicast radio bearers (MRBs) or logical channels (LCHs) used by the terminal device to receive the multicast services.

[0028] Alternatively, the third information includes the maximum number of ROHC-Contexts that the terminal device supports receiving for the multicast service and / or the maximum number of EHC-Contexts that the terminal device supports receiving for the multicast service and / or the maximum number of Multicast Radio Bearers (MRBs) or Logical Channels (LCHs) that the terminal device supports receiving for the multicast service.

[0029] The resources used by a terminal device to receive multicast services can be understood as the resources that the terminal device is currently using to receive multicast services; or the resources used by a terminal device to receive multicast services can be understood as the resources occupied by the terminal device when it wants to receive multicast services; or the resources used by a terminal device to receive multicast services can be understood as the resources that the terminal device plans or reserves for receiving multicast services; or the resources used by a terminal device to receive multicast services can be understood as the maximum resources that the terminal device supports for receiving multicast services.

[0030] In this embodiment, the terminal device reports resources for multicast services to the first access network device, thereby enabling the first access network device to configure a DRB for unicast services for the terminal device based on the multicast service resources, ensuring that the maximum capacity of the terminal device's PDCP is not exceeded.

[0031] Fourthly, a communication method is provided, comprising: a terminal device sending third information to a first access network device to enable the first access network device to configure a data radio bearer (DRB) for the terminal device according to a first indication information, wherein the third information is used to indicate resources used by the terminal device to receive multicast services, the DRB is used to carry unicast services, and the third information includes the number of ROHC-Contexts used by the terminal device to receive the multicast services and / or the number of EHC-Contexts used by the terminal device to receive the multicast services and / or the number of MRBs or LCHs used by the terminal device to receive the multicast services.

[0032] Alternatively, the third information includes the maximum number of ROHC-Contexts that the terminal device supports for receiving the multicast service and / or the maximum number of EHC-Contexts that the terminal device supports for receiving the multicast service and / or the maximum number of Multicast Radio Bearers (MRBs) or Logical Channels (LCHs) that the terminal device supports for receiving the multicast service.

[0033] The resources used by a terminal device to receive multicast services can be understood as the resources currently being used by the terminal device to receive multicast services; or the resources used by a terminal device to receive multicast services can be understood as the resources occupied by the terminal device when it wishes to receive multicast services; or the resources used by a terminal device to receive multicast services can be understood as the resources planned by the terminal device to support receiving multicast services; or the resources used by a terminal device to receive multicast services can be understood as the maximum resources that the terminal device can support for receiving multicast services.

[0034] In conjunction with the fourth aspect, in some implementations of the fourth aspect, before the terminal device sends the third information to the first access network device, the method further includes: the terminal device receiving multicast service data sent by the second access network device.

[0035] Fifthly, a communication method is provided, comprising: a third access network device sending a first data packet to a terminal device using a first packet radio network temporary identifier (G-RNTI), the first data packet corresponding to a first logical channel; when a first preset condition is met, the third access network device retransmitting the first data packet using a cell radio network temporary identifier (C-RNTI); and when a second preset condition is met, the access network device retransmitting the first data packet using the first G-RNTI.

[0036] In this embodiment of the application, under the premise of multiplexing RNTI for logical channels, when the terminal device does not receive new data transmitted using G-RNTI, the third access network device will not use C-RNTI to retransmit, thereby effectively avoiding conflicts and preventing the terminal device from being unable to distinguish which radio bearer RB or which service the HARQ retransmitted data packet belongs to based solely on the logical channel identifier.

[0037] In conjunction with the fifth aspect, in some implementations of the fifth aspect, the first preset condition is that the third access network device receives the NACK feedback of the first data packet, or the first logical channel does not have multiple RNTI multiplexing; the second preset condition is that the access network device does not receive the NACK feedback of the first data packet or the timer times out, and the first logical channel has multiple RNTI multiplexing.

[0038] A sixth aspect provides a communication method, comprising: a terminal device receiving seventh indication information sent by a fourth access network device, the seventh indication information indicating whether the fourth access network device uses C-RNTI to scramble data packets scrambled with G-RNTI during the initial transmission, or the seventh indication information indicating whether the logical channel of the terminal device corresponds to multiple RNTIs; when the seventh indication information indicates that the fourth access network device uses C-RNTI to scramble data packets scrambled with G-RNTI during the initial transmission, the logical channel of the terminal device does not correspond to multiple RNTIs; when the seventh indication information indicates that the fourth access network device does not use C-RNTI to scramble data packets scrambled with G-RNTI during the initial transmission, the logical channel of the terminal device corresponds to multiple RNTIs; when the seventh indication information indicates that the logical channel of the terminal device corresponds to multiple RNTIs, the terminal device does not use C-RNTI to receive retransmitted data packets of data packets scrambled with G-RNTI during the initial transmission; when the seventh indication information indicates that the logical channel of the terminal device does not correspond to multiple RNTIs, the terminal device uses C-RNTI to receive retransmitted data packets of data packets scrambled with G-RNTI during the initial transmission.

[0039] In this embodiment of the application, through the instruction of the fourth access network device, the terminal device can avoid conflicts by determining whether the logical channel corresponds to multiple RNTIs or whether C-RNTI is used to receive retransmitted data packets scrambled with G-RNTI during the initial transmission.

[0040] In conjunction with the sixth aspect, in some implementations of the sixth aspect, the method further includes: the terminal device sending an eighth indication message to the fourth access network device, the eighth indication message being used to indicate whether the terminal device supports receiving retransmission data packets of data packets scheduled to be descrambled using C-RNTI and received using G-RNTI.

[0041] A seventh aspect provides a communication method applied to a terminal device, the terminal device including a first multicast radio bearer (MRB), the first MRB including a first packet data aggregation protocol (PDCP) entity and a first radio link control (RLC) entity, the first RLC entity employing acknowledgement mode (AM), the method including:

[0042] The terminal device receives a first indication message sent by the source node, which indicates that the receiving window of the first PDCP entity should be adjusted when reconstructing the first PDCP entity;

[0043] The terminal device adjusts the receiving window of the first PDCP entity according to the first instruction information.

[0044] For example, the source node can be considered as the source cell or the source access network device.

[0045] In this embodiment of the application, when a terminal device with an AM MRB is configured to switch nodes, the receiving window of the PDCP entity corresponding to the AM MRB can be adjusted so that the terminal device can receive multicast service data normally after switching to the target node, avoiding data packet loss, improving the adaptability of multicast services and the reliability of multicast propagation methods, and improving communication efficiency and user experience.

[0046] In conjunction with the seventh aspect, in some implementations of the seventh aspect, the first indication information specifically indicates that the regional session ID of the target node is inconsistent with the regional session ID of the source node;

[0047] The terminal device adjusts the receiving window of the first PDCP entity according to the first instruction information, including:

[0048] The terminal device initializes the window parameters of the receive window of the first PDCP entity.

[0049] In conjunction with the seventh aspect, in some implementations of the seventh aspect, the first indication information specifically indicates that the PDCP sequence numbers of the target node and the source node are out of sync;

[0050] The terminal device adjusts the receiving window of the first PDCP entity according to the first instruction information, including:

[0051] The terminal device initializes the window parameters of the receive window of the first PDCP entity.

[0052] In conjunction with the seventh aspect, in some implementations of the seventh aspect, the method further includes:

[0053] When the reordering timer is enabled, the terminal device submits the data packets cached by the first PDCP entity.

[0054] In conjunction with the seventh aspect, in some implementations of the seventh aspect, the first instruction signal specifically indicates the superframe number of the target node;

[0055] The terminal device adjusts the receiving window of the first PDCP entity according to the first instruction information, including:

[0056] The terminal device adjusts the window parameters of the receiving window of the first PDCP entity based on the difference between the superframe number of the target node and the superframe number of the source node.

[0057] In conjunction with the seventh aspect, in certain implementations of the seventh aspect, the first indication information is characterized in that the first indication information is included in the first information for indicating the switching node.

[0058] Eighthly, a communication method is provided, the method comprising: a source node sending first indication information to a terminal device, the first indication information indicating that the receiving window of the first PDCP entity is adjusted when reconstructing the first packet data aggregation protocol PDCP entity, wherein the terminal device includes a first multicast radio bearer MRB, the first MRB including the first PDCP entity and a first RLC entity, the first RLC entity adopting acknowledgment mode AM, and the first PDCP entity being associated with the first RLC entity.

[0059] In conjunction with the eighth aspect, in some implementations of the eighth aspect, before the source node sends the first indication information to the terminal device, the method further includes: the source node sending a handover request information to the target node; the source node receiving the handover request confirmation information, the handover request confirmation information including indication information for instructing adjustment of the receiving window of the first PDCP entity.

[0060] In conjunction with the eighth aspect, in some implementations of the eighth aspect, the first indication information specifically indicates that the regional session ID of the target node is inconsistent with the regional session ID of the source node.

[0061] In conjunction with the eighth aspect, in some implementations of the eighth aspect, the first indication information specifically indicates that the sequence numbers of the target node and the source node are out of sync.

[0062] In conjunction with the eighth aspect, in some implementations of the eighth aspect, the first instruction information specifically indicates the superframe number of the target node.

[0063] In conjunction with the eighth aspect, in some implementations of the eighth aspect, the first indication information is characterized in that the first indication information is included in the first information for indicating the switching node.

[0064] A ninth aspect provides a communication method, the method comprising: a target node receiving a handover request information sent by a source node, the source node transmitting data packets of a first service to a first terminal device via a first AM MRB; when the target node determines that the transmission progress of the first AM MRB is slower than the progress of the target node transmitting data packets of the first service to a second terminal device, the target node configuring a second AM MRB to the first terminal device, the second AM MRB being used to transmit data packets of the first service already transmitted by the target node, the second AM MRB being synchronized with the PDCP SN of the first AM MRB.

[0065] It should be understood that the target node supports PDCP SN synchronization.

[0066] In this embodiment of the application, when the first terminal device switches nodes with the first AM MRB configured, the target node can configure the second AM MRB for the terminal device when the transmission progress of the first AM MRB is slower than the transmission progress of the target node, thereby avoiding data packet loss caused by switching nodes and improving user experience.

[0067] In conjunction with aspect nine, in some implementations of aspect nine, the method further includes:

[0068] When the transmission progress of the second AM MRB is the same as that of the first AM MRB, the target node instructs the first terminal device to release or reconfigure the first AM MRB.

[0069] In a tenth aspect, a communication method is provided, the method comprising: a source node sending a handover request message, the source node transmitting data packets of a first service to a first terminal device via a first AM MRB; the source node receiving a handover request confirmation message; and when the source node determines that the transmission progress of the first AM MRB is faster than the progress of the target node sending data packets of the first service to a second terminal device, the source node instructing the first terminal device to reconfigure the first AM MRB.

[0070] In this embodiment of the application, when the first terminal device is configured with the first AM MRB as the switching node, the source node can reconfigure the first AM MRB when the transmission progress of the first AM MRB is faster than that of the target node, thereby avoiding data packet loss caused by switching nodes and improving user experience.

[0071] Eleventhly, a communication apparatus is provided for performing the method in any of the possible implementations of the first to sixth aspects described above. Specifically, the apparatus may include units and / or modules for performing the method in any of the possible implementations of the first to sixth aspects, such as processing units and / or communication units. In one implementation, the apparatus is a communication device (e.g., a terminal device, or a network device). When the apparatus is a communication device, the communication unit may be a transceiver, or an input / output interface; the processing unit may be at least one processor. Optionally, the transceiver may be a transceiver circuit. Optionally, the input / output interface may be an input / output circuit. In another implementation, the apparatus is a chip, chip system, or circuit for a communication device (e.g., a terminal device, or a network device). When the apparatus is a chip, chip system, or circuit for a communication device, the communication unit may be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip, chip system, or circuit; the processing unit may be at least one processor, processing circuit, or logic circuit.

[0072] In a twelfth aspect, a communication apparatus is provided, comprising: at least one processor for executing a computer program or instructions stored in a memory to perform the method in any of the possible implementations of the first to fourth aspects described above.

[0073] Optionally, the device further includes a memory for storing computer programs or instructions. Optionally, the device further includes a communication interface through which the processor reads the computer programs or instructions stored in the memory.

[0074] In one implementation, the device is a communication device (such as a terminal device or a network device).

[0075] In another implementation, the device is a chip, chip system, or circuit for communication equipment (such as terminal equipment or network equipment).

[0076] In a thirteenth aspect, this application provides a processor for performing the methods provided in the first to sixth aspects above. Unless otherwise specified, or if it does not contradict its actual function or internal logic in the relevant description, the transmission and acquisition / reception operations involved in the processor can be understood as processor output and reception, input, and other operations, or as transmission and reception operations performed by radio frequency circuits and antennas; this application does not limit these operations.

[0077] In a fourteenth aspect, a computer-readable storage medium is provided that stores program code for execution by a device, the program code including methods for performing any of the possible implementations of the first to sixth aspects described above.

[0078] In a fifteenth aspect, a computer program product containing instructions is provided, which, when run on a computer, causes the computer to perform the method in any one of the possible implementations of the first to sixth aspects described above.

[0079] In a sixteenth aspect, a communication system is provided, including the aforementioned terminal equipment and access network equipment.

[0080] For the beneficial effects in aspects eleven through sixteen, please refer to the beneficial effects in aspects one through ten, which will not be repeated here. Attached Figure Description

[0081] Figure 1 This is a schematic diagram showing the data transmission at each layer of the protocol stack.

[0082] Figure 2 This is a schematic diagram of the architecture of a mobile communication system applicable to embodiments of this application.

[0083] Figure 3 This is a schematic flowchart of the communication method provided in the embodiments of this application.

[0084] Figure 4 This is a schematic flowchart illustrating another communication method provided in the embodiments of this application.

[0085] Figure 5 This is a schematic flowchart illustrating another communication method provided in the embodiments of this application.

[0086] Figure 6 This is a schematic flowchart illustrating another communication method provided in the embodiments of this application.

[0087] Figure 7 This is a schematic flowchart illustrating another communication method provided in the embodiments of this application.

[0088] Figure 8This is a schematic flowchart illustrating another communication method provided in the embodiments of this application.

[0089] Figure 9 This is a schematic flowchart illustrating another communication method provided in the embodiments of this application.

[0090] Figure 10 This is a schematic flowchart illustrating another communication method provided in the embodiments of this application.

[0091] Figure 11 This application provides a schematic block diagram of an apparatus.

[0092] Figure 12 This application provides a schematic block diagram of an apparatus. Detailed Implementation

[0093] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0094] The technical solutions of this application embodiment can be applied to various communication systems, such as: Global System of Mobile communication (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD) system, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) system, 5th Generation (5G) system or New Radio (NR) system, and future evolution communication systems, etc.

[0095] The terminal device in this application embodiment can refer to user equipment, access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device. The terminal device can also be a cellular phone, cordless phone, Session Initiation Protocol (SIP) phone, Wireless Local Loop (WLL) station, Personal Digital Assistant (PDA), handheld device with wireless communication capabilities, computing device or other processing device connected to a wireless modem, in-vehicle device, wearable device, terminal device in future 5G networks, or terminal device in future evolved Public Land Mobile Network (PLMN), etc., and this application embodiment does not limit this to these categories.

[0096] The network device in this application embodiment can be a device for communicating with terminal devices. The network device can be a base station (BTS) in a Global System of Mobile communication (GSM) system or Code Division Multiple Access (CDMA), a base station (NodeB, NB) in a Wideband Code Division Multiple Access (WCDMA) system, an evolved NodeB (eNB or eNodeB) in an LTE system, a radio controller in a Cloud Radio Access Network (CRAN) scenario, or a relay station, access point, vehicle-mounted device, wearable device, or a network device in a future 5G network or a network device in a future evolved PLMN network, etc. The embodiments of this application are not limited.

[0097] Furthermore, various aspects or features of this application can be implemented as methods, apparatus, or articles of manufacture using standard programming and / or engineering techniques. The term "article of manufacture" as used herein encompasses a computer program accessible from any computer-readable device, carrier, or medium. For example, computer-readable media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks, or magnetic tapes), optical discs (e.g., compact discs (CDs), digital versatile discs (DVDs), etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memory (EPROMs), cards, sticks, or key drives, etc.). Additionally, the various storage media described herein may represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing, and / or carrying instructions and / or data.

[0098] To facilitate understanding of the embodiments of this application, some terms used in the embodiments of this application are explained below, so that those skilled in the art can understand them.

[0099] 1) Network equipment, which includes devices or chips that can be configured to provide random access functionality for terminal devices. This equipment includes, but is not limited to: evolved Node B (eNB), radio network controller (RNC), Node B (NB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home-evolved Node B, or home Node B, HNB), baseband unit (BBU), access point (AP), wireless relay node, wireless backhaul node, and transmission and reception point (TRP or transmission...) in a Wi-Fi system. It can also refer to a gNB in ​​a 5G system, such as a transmission point (TP), a base station in a 5G system (including multiple antenna panels), an antenna panel, or a network node that constitutes a gNB or transmission point, such as a baseband unit (BBU) or a distributed unit (DU).

[0100] 2) A terminal, also known as user equipment (UE), mobile station (MS), or mobile terminal (MT), is a device that provides voice and / or data connectivity to a user. For example, terminal devices include handheld devices with wireless connectivity and in-vehicle devices. Currently, terminal devices can include: mobile phones, tablets, laptops, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving cars, and wireless terminals in remote medical surgery, etc.

[0101] 3) Multicast transmission technology, also known as multimedia broadcast multicast service (MBMS) technology, multicast transmission method, or multicast and broadcast service (MBS) technology, refers to a technology that allows a certain service to simultaneously send data to multiple terminal devices through network equipment. When using multicast technology for transmission, multiple terminal devices simultaneously receive the same data while the network equipment (e.g., a base station) is transmitting it.

[0102] 4) Transmission using multicast means that when a device transmits the transport block (TB) corresponding to a protocol data unit (PDU), it scrambles the PDU with a group radio network temporary identifier (G-RNTI) or scrambles the downlink control information (DCI) corresponding to the PDU, and one or more devices simultaneously receive the same PDU based on the same G-RNTI; or, transmitting a PDU using multicast means that the location of the same PDU is told to multiple devices in a semi-static way, and multiple devices can receive the PDU simultaneously; or, transmitting a PDU using multicast means that the PDU is transmitted in a radio bearer established for multicast transmission or in a channel specifically designed for multicast.

[0103] Currently, the standard supports one G-RNTI for multiple multicast services, as well as the ability of the same logical channel to carry both unicast and multicast services, or multiple multicast or unicast services (also known as logical channel multiplexing).

[0104] Furthermore, if a terminal device does not receive data transmitted using G-RNTI within the same HARQ process, it can retransmit the data using either the cell radio network temporary identifier (C-RNTI) or G-RNTI.

[0105] Receiving using multicast transmission means that when transmitting using multicast, one of the multiple receiving devices receives the PDU according to G-RNTI; or one of the multiple receiving devices receives the PDU through a radio bearer established for multicast transmission or on a channel used for multicast transmission.

[0106] In this application, multicast is a specific method of multicast; therefore, multicast can also be called multicast, broadcast, or MBS.

[0107] 5) Transmitting via unicast means that when a device transmits the TB corresponding to the PDU, it scrambles the PDU with the cell network temporary identifier (C-RNTI) or the DCI corresponding to the PDU, and only one device receives the same PDU according to the C-RNTI; or transmitting the PDU via unicast means that the PDU is transmitted in a radio bearer established for unicast transmission or in a channel specifically designed for unicast.

[0108] Receiving using unicast transmission means that when transmitting using unicast, the receiving device receives the PDU according to the C-RNTI; or the device receives through a radio bearer established for unicast transmission or on a channel used for unicast transmission.

[0109] 6) Sending and receiving using broadcast transmission means that a device sends the TB corresponding to the PDU on a broadcast channel, and all receiving devices can receive the PDU on the broadcast channel.

[0110] Interoperable network devices and terminal devices have a specific protocol layer structure. For example, the control plane protocol layer structure may include the functions of protocol layers such as RRC, PDCP, RLC, MAC, and physical layers. The user plane protocol layer structure may also include the functions of protocol layers such as PDCP, RLC, MAC, and physical layers. The physical layer is located at the lowest layer (layer one), the MAC, RLC, and PDCP belong to the second layer (layer two), and RRC belongs to the third layer (layer three). In one implementation, a service data adaptation protocol (SDAP) layer may be included above the PDCP layer.

[0111] The functions of these protocol layers can be implemented by a single node or by multiple nodes. For example, in one evolutionary architecture, the radio access network equipment may include centralized units (CUs) and distributed units (DUs), with multiple DUs being centrally controlled by a single CU. CUs and DUs can be distinguished according to the protocol layers of the wireless network; for example, the functions of PDCP and higher protocol layers are located in the CU, while the functions of lower protocol layers, such as RLC and MAC layers, are located in the DU.

[0112] It should be understood that this protocol layer division is merely an example. It can also be applied to other protocol layers, such as the RLC layer, where the functions of the RLC layer and above are placed in the CU, and the functions of the protocol layers below the RLC layer are placed in the DU. Alternatively, it can be divided within a specific protocol layer, for example, placing some functions of the RLC layer and the functions of the protocol layers above the RLC layer in the CU, and placing the remaining functions of the RLC layer and the functions of the protocol layers below the RLC layer in the DU. Furthermore, it can be divided in other ways, such as by latency, placing functions whose processing time needs to meet latency requirements in the DU, and functions that do not need to meet this latency requirement in the CU.

[0113] When data transmission occurs between network devices and terminal devices, taking downstream data transmission as an example, such as... Figure 1 As shown, Figure 1 This diagram illustrates the data transmission process at each layer of the protocol stack. Data first arrives at the PDCP layer of the network device. After processing at the PDCP layer, it is transmitted to the RLC and MAC layers. After further processing at the MAC layer, it is sent to the network device via the physical layer. When a terminal device receives data, the protocol layers it passes through in sequence are the physical layer, MAC layer, RLC layer, and PDCP layer. Data in each radio bearer requires processing at each layer. Each layer has corresponding functional entities to perform its respective function; for example, the PDCP layer corresponds to the PDCP entity, the RLC layer to the RLC entity, and the MAC layer to the MAC entity. Each radio bearer contains one PDCP entity and one or more RLC entities, each RLC entity corresponding to a logical channel. One MAC entity corresponds to multiple logical channels. Data in logical channels can be multiplexed at the MAC layer, for example, multiplexed into the same data block, and finally sent out via the physical layer. The transmission process for uplink data is similar.

[0114] Figure 2 This is a schematic diagram of a communication system applicable to embodiments of this application. For example... Figure 2 As shown, the mobile communication system 100 may include at least one radio access network device 110 and at least one terminal device (such as...). Figure 2The terminal devices 120, 130, 140, 150, and 160 shown are connected wirelessly to a wireless access network device, which can be one of the aforementioned network devices. At least one terminal device can send uplink data or information to the wireless access network device, and the wireless access network device 110 can also send downlink data or information to at least one terminal device. Furthermore, multiple terminal devices can form a communication system; for example, terminal devices 140, 150, and 160 can form a communication system where terminal device 140 can send downlink data or information to terminal devices 150 and 160, and terminal devices 150 and 160 can send uplink data or information to terminal device 140. Uplink and downlink data and information related to URLLC services can be transmitted between the terminal devices and the wireless access network device.

[0115] This should be understood. Figure 2 This is just an illustration; the communication system may also include other network devices and / or terminal devices. Figure 2 Not shown in the diagram. The embodiments of this application do not limit the number of wireless access network devices and terminals included in the mobile communication system. In the mobile communication system 100, the wireless access network device 110 can be the network device described above. Furthermore, the communication between the network device and the terminal device follows a certain protocol layer structure. For example, as... Figure 1 The protocol layer architecture is shown. Network devices may include CU and DU, which can be configured separately or centrally. This application does not impose limitations on the embodiments described herein.

[0116] Currently, when terminal devices receive multicast services, there may be issues such as lost data packets and inability to correctly map data packets to the corresponding MRBs, which affects the user experience.

[0117] In some scenarios, for multicast services, user plane data is carried by a multicast radio bearer (MRB). MRBs can be divided into unacknowledged mode (UM) and acknowledged mode (AM). The classification of an MRB can depend on the state of the RLC entity; when an MRB includes an AM RLC entity, it can be an AM MRB. Currently, when a terminal device configured with an AM MRB switches from a source node to a target node, it may affect the terminal device's normal data reception at the target node. For example, when the terminal device switches from a source node to a target node, if there are still data packets in the PDCP entity's receive window that have not been delivered to the upper layer, and the PDCP sequence numbers of the data packets in the target node and the source node are generated differently, it will affect the terminal device's normal data reception at the target node. Another example is that if the Hyperframe Number (HFN) of the target node and the source node are different, the window parameters of the terminal device's PDCP entity's receive window will not be applicable to the target node, which may result in the inability to receive data normally. For example, the data packets of the target node are not within the receiving window of the PDCP entity of the current terminal device, or the data packets of the target node and the data packets of the source node have some data packets with the same serial number but different content, resulting in a conflict between the two streams of data.

[0118] In some scenarios, the PDCP resources of a terminal device are limited, and PDCP resources can also be understood as PDCP capabilities. Currently, when access network devices configure the data radio bearer (DRB) for unicast on terminal devices, they do not consider the PDCP resources occupied by multicast services. If the PDCP resources occupied by unicast and multicast services exceed the total PDCP resources of the terminal device, some services may be discarded, resulting in unreceived services and reduced service performance. In some scenarios, network devices configure the PDCP resources of the DRB for terminal devices at the maximum usable value. The sum of the maximum usable resources of all DRBs does not exceed the total PDCP capability of the terminal device. The PDCP resources are only actually used when the service flow arrives. This means that if the terminal device receives both multicast and unicast data simultaneously, the resources configured by the access network device for the terminal device, or reserved for the DRB by the terminal device, may not be fully utilized. Due to capacity limitations, the terminal device may trigger the deletion of the DRB or stop receiving multicast services when simultaneously receiving unicast and multicast services. In this situation, PDCP resources are not fully utilized, but are not allocated to services that require PDCP resources, resulting in the shutdown of some services or some data streams.

[0119] In some scenarios, due to the multiplexing of logical channels and the retransmission of R-RNTI data using C-RNTI, terminal devices may be unable to map data to the correct radio bearer (RB). For example, when a terminal device receives a retransmission of a data packet that was initially scrambled using G-RNTI and then scrambled using C-RNTI, the terminal device can obtain the logical channel identifier after descrambling using C-RNTI. If the logical channel is multiplexed for multiple multicast services, the terminal needs to match the logical channel identifier with the G-RNTI to determine which MRB or multicast service the retransmitted data packet belongs to. If the corresponding G-RNTI cannot be found based on the logical channel identifier, the terminal device cannot determine the service corresponding to the retransmitted data packet because multiple services' G-RNTIs correspond to this logical channel. For example, the first multicast service corresponds to the first G-RNTI, the first multicast service corresponds to the first logical channel, the first logical channel also corresponds to the second multicast service, and the second multicast service corresponds to the second G-RNTI. When the transmission of the first data packet of the first multicast service fails and the first data packet is scrambled and retransmitted using C-RNTI, and the terminal device receiving the first multicast service and the second multicast service receives the retransmitted first data packet scrambled using C-RNTI, since the initial data and the retransmitted data are in the same HARQ process, the logical channel corresponding to the first data packet can be parsed as the first logical channel. However, since the G-RNTI cannot be determined, the terminal device cannot determine whether the first data packet corresponds to the first multicast service or the second multicast service. For example, the first logical channel corresponds to the first C-RNTI and the first G-RNTI, the first multicast service corresponds to the first G-RNTI, and the first unicast service corresponds to the C-RNTI. When the transmission of the first data packet of the first multicast service fails and the first data packet is scrambled and retransmitted using C-RNTI, the terminal device obtains the logical channel corresponding to the first data packet as the first logical channel through C-RNTI. However, since the first G-RNTI cannot be determined, the terminal device cannot determine whether the first data packet corresponds to the first multicast service or the first unicast service.

[0120] In summary, this application proposes a communication method and a communication device that can ensure that the multicast service of the terminal device can receive data normally, avoid the loss of data packets, thereby improving the user experience and reducing the waste of network resources.

[0121] The following is combined with Figure 3 This application provides a detailed description of the communication method. Figure 3 This is a schematic flowchart of a communication method 300 according to an embodiment of this application. Method 300 can be applied to... Figure 2 In the scenarios shown, for example, in scenarios where multicast transmission is used.

[0122] S301, the source node sends a first indication message to the terminal device, the first indication message indicating that the receiving window of the first PDCP entity should be adjusted when rebuilding the first packet data aggregation protocol PDCP entity.

[0123] Correspondingly, the terminal device receives the first instruction information.

[0124] Specifically, the terminal device includes a first MRB, which comprises a first PDCP entity and a first RLC entity, the first RLC entity using Acknowledgment Mode (AM). The terminal device and the source node can transmit data for a first service through the first MRB. The source node sends a first indication message to the terminal device, which instructs the terminal device to adjust the receive window of the first PDCP entity when reconstructing it.

[0125] It should be noted that the first MRB may also include multiple RLC entities. For example, the first MRB may also include a second RLC entity, which adopts the non-acknowledgment mode UM.

[0126] For example, the first indication information may be included in the switching indication information (RRC Reconfiguration).

[0127] Before the source node sends the first indication information to the terminal device, method 300 further includes:

[0128] S304, The source node sends a handover request message to the target node. This handover request message is used to request the service node of the terminal device to be switched.

[0129] S305, the source node receives the handover request confirmation information, which includes indication information for instructing the adjustment of the receive window of the first PDCP entity.

[0130] For example, when a terminal device needs to switch nodes, the source node will request to switch base stations via handover request signaling. After receiving the handover request signaling, the target node can send a handover request ACK signaling, which includes indication information indicating the adjustment of the receive window of the first PDCP entity.

[0131] It should be understood that the node in the embodiments of this application can be either a cell or an access network device. That is, when a terminal device configured with AMMRB switches from a source cell to a target cell, the terminal device can adjust the receiving window of the first PDCP entity; or when a terminal device configured with AMMRB switches from a source base station to a target base station, the terminal device can adjust the receiving window of the first PDCP entity. The embodiments of this application do not limit this. For simplicity, unless otherwise specified, when referring to a terminal device in the following description of method 300, the terminal device can be understood as a terminal device configured with AMMRB.

[0132] It should be noted that the source node can transparently transmit the target node's indication information, i.e., this indication information is the first indication information, and the source node simply forwards this indication information. Alternatively, the source node can generate the first indication information based on the target node's ACK feedback, and this first indication information is included in the first information (e.g., RRCReconfiguration signaling) used to instruct the terminal device to switch nodes. This application embodiment does not limit this aspect.

[0133] In this application, the source node may instruct the terminal device to adjust the receive window of the PDCP entity when reconstructing the PDCP entity, and the target node may also instruct the terminal device to adjust the receive window of the PDCP entity when reconstructing the PDCP entity. This application does not limit this.

[0134] For example, the source node sends a handover request signaling to the target node to request a switchover. After receiving the handover request signaling, the target node can send a handover request ACK. Then, the source node includes first indication information in the RRC Reconfiguration signaling to the terminal device to instruct the terminal device to adjust the receive window of the PDCP entity when rebuilding the PDCP entity.

[0135] For example, the source node sends a handover request signaling to the target node to request a node handover. After receiving the handover request signaling, the target node can send a handover request ACK. The handover request ACK includes indication information for instructing the adjustment of the receive window of the PDCP entity. After receiving the handover request ACK, the source node then includes the indication information (i.e., it can be understood as the first indication information) in the RRC Reconfiguration signaling sent to the terminal device to instruct the terminal device to adjust the receive window of the PDCP entity when rebuilding the PDCP entity.

[0136] For example, the source node sends a handover request signaling to the target node to request a node handover. After receiving the handover request signaling, the target node can send a handover request ACK. The handover request ACK includes indication information for instructing the adjustment of the receive window of the PDCP entity. After receiving the handover request ACK, the source node generates first indication information based on the handover request ACK, and then includes the first indication information in the RRC Reconfiguration signaling sent to the terminal device to instruct the terminal device to adjust the receive window of the PDCP entity when rebuilding the PDCP entity.

[0137] Optionally, in some embodiments, the first instruction information may directly instruct the terminal device to adjust the receiving window of the first PDCP entity when reconstructing the first PDCP entity.

[0138] For example, the first indication information may include one or more bits, such as 00 indicating that the receive window of the PDCP entity is not adjusted when rebuilding the PDCP entity, and 01 indicating that the receive window of the PDCP entity is adjusted when rebuilding the PDCP entity.

[0139] The terminal device adjusts the receive window of the first PDCP entity, including:

[0140] The terminal device initializes the window parameters of the receive window of the first PDCP entity. The window parameters of the receive window of the first PDCP entity include at least one of TX_NEXT, RX_NEXT, and RX_DELIV; or

[0141] The terminal device adjusts the window parameters of the receiving window of the first PDCP entity based on the HFN of the target node and the source node.

[0142] Optionally, in some embodiments, the first instruction information may also indirectly instruct the terminal device to adjust the receiving window of the first PDCP entity when reconstructing the first PDCP entity.

[0143] In some embodiments, the first indication information includes second indication information, which is used to indicate that the regional session ID of the target node is inconsistent with the regional session ID of the source node.

[0144] Specifically, a multicast service can be associated with multiple multicast service areas. Each multicast service area includes a region session ID. When the second indication information indicates that the region session IDs of the source node and the target node are inconsistent, the terminal device can know that the receiving window of the PDCP entity needs to be adjusted when rebuilding the PDCP entity based on the content included in the second indication information.

[0145] It should be noted that in some cases, the inclusion of the second indication information in the first indication information can be understood as the first indication information being equivalent to the second indication information. In this case, the second indication information used to indicate that the regional session ID of the target node is inconsistent with the regional session ID of the source node can be understood as the first indication information specifically indicating that the regional session ID of the target node is inconsistent with the regional session ID of the source node.

[0146] In other cases, the inclusion of second instruction information in the first instruction information can be understood as the second instruction information being contained within the first instruction information.

[0147] The second indication information can directly indicate that the regional session IDs of the source node and the target node are inconsistent. For example, the second indication information may include one or more bits, such as 00 indicating that the regional session IDs of the source node and the target node are inconsistent, and 01 indicating that the regional session IDs of the source node and the target node are consistent.

[0148] One possible implementation is that when the source node sends the handover request information to the target node, it also reports its area session ID. After receiving the handover request information, the target node can determine that the area session ID of the source node is different from the area session ID of the target node. Then, the target node can send a second indication information when sending the handover request confirmation information to the source node.

[0149] Another possible implementation is that the source node sends handover information to the target node. After receiving the handover request information, the target node sends its area session ID when sending the handover request confirmation information to the source node. After receiving the handover request confirmation information, the source node can determine that the area session ID of the target node is different from its area session ID. Then the source node can generate and send a second indication information to the terminal device.

[0150] The second indication information can also indirectly indicate that the regional session IDs of the source node and the target node are inconsistent. For example, the second indication information includes the regional session IDs of the source node and / or the target node. When the terminal device receives the second indication information, it can ultimately determine whether the regional session IDs of the source node and the target node are consistent based on the content of the second indication information.

[0151] One possible implementation is that the source node sends handover information to the target node. After receiving the handover request information, the target node sends its area session ID when sending the handover request confirmation information to the source node. After receiving the handover request confirmation information, the source node sends a second indication information to the terminal device. The second indication information includes the area session ID of the source node and the area session ID of the target node.

[0152] In other embodiments, the first indication information includes a third indication information, which is used to indicate that the PDCP serial numbers (SN) of the target node and the source node are out of sync.

[0153] Specifically, to ensure the normal operation of multicast services during node switching, the PDCP SNs of the target and source nodes must be synchronized. When the third indication information indicates that the PDCP SNs of the target and source nodes are out of sync, the terminal device needs to adjust the receive window of the PDCP entity when rebuilding the PDCP entity. PDCP SN synchronization can be understood as the source and target nodes having the same PDCP SN number for the same data packet from the core network.

[0154] For a description of the relationship between the first instruction information and the third instruction information, please refer to the description of the first instruction information and the second instruction information. For the sake of brevity, it will not be repeated here.

[0155] The third indication information can directly indicate that the PDCP SNs of the source node and the target node are out of sync. For example, the third indication information may include one or more bits, such as 00 indicating that the regional session PDCP SNs of the source node and the target node are out of sync, and 01 indicating that the PDCP SNs of the source node and the target node are synchronized.

[0156] One possible implementation is that when the source node sends the handover request information to the target node, it also reports whether its PDCP SN is synchronized. After receiving the handover request information, the target node can determine whether the source node is synchronized with its PDCP SN. Therefore, the target node can send a third indication information when sending the handover request confirmation information to the source node.

[0157] Another possible implementation is that the source node sends handover information to the target node. After receiving the handover request information, the target node sends whether it is PDCP SN synchronized when sending the handover request confirmation information to the source node. After receiving the handover request confirmation information, the source node can determine whether the target node is PDCP SN synchronized. Then the source node can generate and send third indication information to the terminal device.

[0158] The third indication information can also indirectly indicate that the PDCP SNs of the source node and the target node are out of sync. For example, the third indication information can indicate the method by which the source node and the target node synchronize their PDCP SNs. When the methods of synchronizing the PDCP SNs of the source node and the target node are different, it can be considered that the PDCP SNs of the source node and the target node are out of sync. This application does not limit the method of synchronizing the PDCP SN. For example, the methods of synchronizing the PDCP SN may include: a first synchronization method that reuses the SN of the GPRS Tunneling Protocol for the user plane (GTP-U) packet header; a second synchronization method that adds a new extension header for synchronizing the PDCP SN; a third synchronization method that reuses the Quality of Service Flow Identity (QFI) SN of the GTP-U Container extension header; and a fourth synchronization method that implements PDCP SN synchronization based on the common next-generation nodeB centralized unit user plane (gNB-CU-UP).

[0159] It should be understood that the above synchronization methods are merely examples. In the embodiments of this application, the source node and the target node may also adopt other synchronization methods to implement the methods of the embodiments of this application, which should also fall within the protection scope of this application.

[0160] One possible implementation is that when the source node sends a handover request to the target node, it also reports its PDCPSN synchronization method. After receiving the handover request, the target node can determine whether the source node has the same synchronization method. If the synchronization methods are different, the target node can also send a third indication message when sending the handover request confirmation message to the source node.

[0161] Another possible implementation is that the source node sends handover information to the target node. After receiving the handover request information, the target node sends its PDCP SN synchronization method when sending the handover request confirmation information to the source node. After receiving the handover request confirmation information, the source node can determine whether the target node has the same synchronization method. If the synchronization methods are different, the source node can generate and send a third indication information to the terminal device.

[0162] Optionally, in other embodiments, the first indication information includes fourth indication information, which is used to indicate the HFN of the target node.

[0163] Specifically, the window parameter of the PDCP entity's receive window is based on the count value of the PDU DATA, which includes the HFN and PDCP SN. The HFN is maintained by both the receiver and transmitter. When the fourth indication information indicates the HFN of the target node, the terminal device, upon receiving this fourth indication information, can determine whether to adjust the PDCP entity's receive window during PDCP entity reconstruction by combining the HFN currently maintained by the terminal device and the source node, and based on the content included in the fourth indication information. If the HFNs are consistent, no adjustment is needed. If the HFNs are inconsistent, adjustment is required.

[0164] One possible implementation: The source node sends a handover request to the target node. After receiving the handover request, the target node can send its HFN (i.e., fourth indication information) when sending the handover request confirmation to the source node. After receiving the handover request confirmation, the source node sends the target node's HFN to the terminal device. Thus, the terminal device can determine whether the HFNs of the source node and the target node are consistent, given the information of their respective HFNs.

[0165] S302, the terminal device adjusts the receiving window of the first PDCP entity according to the first instruction information.

[0166] Optionally, in some embodiments, the first instruction information may directly instruct the terminal device to adjust the receiving window of the first PDCP entity when reconstructing the first PDCP entity.

[0167] Specifically, after receiving the first instruction information, the terminal device can adjust the receiving window of the first PDCP entity when reconstructing the first PDCP entity. For example, the terminal device initializes the window parameters of the receiving window of the first PDCP entity.

[0168] For example, after receiving the first instruction information, the terminal device can initialize the values ​​of RX_NEXT and RX_DELIV.

[0169] Optionally, in some embodiments, the first indication information includes second indication information, which is used to indicate that the regional session ID of the target node is inconsistent with the regional session ID of the source node.

[0170] After receiving the second indication information, the terminal device can determine that the area session IDs of the target node and the source node are inconsistent. Therefore, when reconstructing the first PDCP entity, the terminal device can adjust the receive window of the first PDCP entity. For example, the terminal device can initialize the window parameters of the receive window of the first PDCP entity.

[0171] Optionally, in some embodiments, the first indication information includes a third indication information, which is used to indicate that the PDCP SN of the target node and the source node are out of sync.

[0172] After receiving the third indication information, the terminal device can determine that the PDCP SN of the target node and the source node are out of sync. Therefore, the terminal device can adjust the receive window of the first PDCP entity when reconstructing it. For example, the terminal device can initialize the window parameters of the receive window of the first PDCP entity.

[0173] In this embodiment of the application, when a terminal device configured with AM MRB switches nodes, the receiving window of the PDCP entity corresponding to AM MRB can be initialized. This avoids conflicts between data packets of the target node and data packets cached in the source node due to the window not being initialized, thereby avoiding problems such as the terminal device dropping data packets and data packets being out of order.

[0174] Optionally, in some embodiments, the first indication information includes fourth indication information, which is used to indicate the HFN of the target node.

[0175] After receiving the fourth indication information, if the terminal device determines that the HFNs of the target node and the source node are inconsistent, it can adjust the window parameters of the receiving window of the first PDCP entity based on the difference between their HFNs. For example, if the HFN maintained by the source node and the terminal device is 5, and the HFN maintained by the target node is 10, then the window parameters of the receiving window of the first PDCP entity will all be increased by 5*2. [PDCP SN Size] .

[0176] Furthermore, when the adjusted window parameters exceed the range of [0, 2]... 32 When -1], the terminal device can release or reconfigure the AM MRB.

[0177] Optionally, in some embodiments, method 300 further includes:

[0178] S304, when the reordering timer is enabled, submit the data packet of the first PDCP entity buffer.

[0179] Specifically, when the reordering timer of the terminal device is enabled, when it is necessary to adjust the receive window of the first PDCP entity, the buffered data packets can be delivered in ascending order of the count value.

[0180] In this embodiment of the application, when a terminal device with an AM MRB configured switches nodes, the receiving window of the PDCP entity corresponding to the AM MRB can be adjusted. This ensures that when the terminal device switches to the target node, the data from the source node and the target node are not inconsistent, thus avoiding the impact of the source node's data packets on the terminal device's reception of the target node's data packets and preventing the loss of data packets received and cached by the terminal device from the source node, thereby improving the user experience.

[0181] Figure 4 The diagram shown is a schematic flowchart of another communication method 400 provided in this application embodiment. This method 400 can be applied to... Figure 2 In the scenario shown, the target node in method 400 supports PDCP SN synchronization, but the target node does not use PDCP SN when sending data.

[0182] S401, the first terminal device and the source node transmit data packets of the first service through the first AM MRB.

[0183] S402, the source node sends a handover request to the target node.

[0184] Correspondingly, the target node receives the handover request information sent by the source node.

[0185] S403, the target node sends a handover request confirmation message to the source node.

[0186] Correspondingly, the source node receives the handover request confirmation information sent by the target node.

[0187] S404, the target node determines that the transmission progress of the first AM MRB is slower than the progress of the target node sending the data packets of the first service to the second terminal device.

[0188] Specifically, the target node can also send data packets of the first service to terminal devices other than the first terminal device (such as the second terminal device). Its transmission progress may be faster than that of the source node. The transmission progress of the first service of the source node is equivalent to the transmission progress of the first AM MRB. When the target node determines that the transmission progress of the first AM MRB is slower than the progress of the target node sending data packets of the first service to the second terminal device, S405 can be performed.

[0189] It should be noted that the target node did not synchronize the PDCPSN when sending the first service data packet to the second terminal device. That is, when the source node and the target node sent the same first service data packet, they did not use the same PDCP SN.

[0190] The transmission progress of the first AM MRB for the target node can be determined in the following ways:

[0191] Method 1: The source node can indicate the transmission progress of the first AM MRB through SN Status Transfer signaling.

[0192] Method 2: The source node can report the transmission progress of the first AM MRB in the handover request information.

[0193] Method 3: The target node can determine the transmission progress of the first AM MRB through core network elements.

[0194] Method 4: The target node can determine the transmission progress of the source node when switching nodes using terminal devices other than the first terminal device.

[0195] It should be understood that the embodiments of this application do not limit the method by which the target node determines the transmission progress of the first AM MRB. Any method of implementing this application that determines the transmission progress of the first AM MRB in a manner other than the four methods mentioned above should fall within the protection scope of this application.

[0196] S405, the target node configures a second AM MRB to the first terminal device. The second AM MRB is used to transmit data packets of the first service that the target node has transmitted. The second AM MRB is synchronized with the PDCP SN of the first AM MRB.

[0197] Specifically, when the target node determines that the transmission progress of the first AM MRB is slower than the progress of the target node sending the data packets of the first service to the second terminal device, it can configure the second AM MRB to transmit the data packets of the first service that the target node has already transmitted.

[0198] One possible implementation is that the second AM MRB is used to transmit all the data packets of the first service that the target node has already transmitted. For example, if the first terminal device has received the first 500 data packets of the first service through the first AM MRB, and the target node has already sent the first 600 data packets of the first service to the second terminal device, then the target node's transmission progress of the first service is faster than the transmission progress of the first AM MRB. In this case, the target node can configure a new AM MRB for the first terminal device, which is used to transmit the first 600 data packets of the first service.

[0199] One possible implementation is that the second AM MRB is used to transmit all data packets of the first service that the source node has already transmitted. For example, if the first terminal device has received the first 500 data packets of the first service through the first AM MRB, and the target node has already sent the first 600 data packets of the first service to the second terminal device, then the target node's transmission progress of the first service is faster than the transmission progress of the first AM MRB. In this case, the target node can configure a new AM MRB for the first terminal device, which is used to transmit the first 500 data packets of the first service.

[0200] One possible implementation is that the second AM MRB is used to transmit data packets of the first service that the target node has transmitted but the source node has not. For example, if the first terminal device has received the first 500 data packets of the first service through the first AM MRB, and the target node has already sent the first 600 data packets of the first service to the second terminal device, then the target node's transmission progress of the first service is faster than the transmission progress of the first AM MRB. In this case, the target node can configure a new AM MRB for the first terminal device, which is used to transmit data packets 501 to 600 of the first service.

[0201] Furthermore, in one possible implementation, the second AM MRB is also used to continue transmitting data packets for the first service.

[0202] For example, if the first terminal device has received the first 500 data packets of the first service through the first AM MRB, and the target node has sent the first 600 data packets of the first service to the second terminal device, then the target node's transmission progress of the first service is faster than the transmission progress of the first AM MRB. In this case, the target node can configure a new AM MRB for the first terminal device. This AM MRB is used to transmit the 501st to the 600th data packets of the first service, as well as the data packets after the 600th data packet.

[0203] The synchronization of the PDCP SN between the second AM MRB and the first AM MRB can be understood as the first AM MRB and the second AM MRB carrying the same data packet having the same PDCP SN.

[0204] Furthermore, when the transmission progress of the second AM MRB is the same as that of the first AM MRB, method 400 further includes:

[0205] S406, the target node instructs the first terminal device to release or reconfigure the first AM MRB.

[0206] Alternatively, S406 is performed when the transmission progress of the second AM MRB is the same as that of the first AM MRB and the duration reaches the first threshold.

[0207] Alternatively, S406 is performed when the transmission progress of the second AM MRB exceeds the transmission progress of the first AM MRB by reaching a second threshold. For example, if the second threshold is 50 and the transmission progress of the first AM MRB is 500 data packets, then S406 is performed when the transmission progress of the second AM MRB reaches 550.

[0208] Alternatively, S406 is performed when the number of data packets that differ between the transmission progress of the second AM MRB and the transmission progress of the first AM MRB is less than a third threshold.

[0209] Alternatively, S406 is performed when the target node has more data packets cached than the third threshold or when the target node is unable to cache new data packets.

[0210] For example, when the transmission progress of the second AM MRB is the same as that of the first AM MRB, the target node can instruct the first terminal device to release or reconfigure the first AM MRB. For example, if the transmission progress of the first AM MRB is the first 500 data packets of the first service, then when the transmission of the second AM MRB reaches the 500th data packet, the target node can instruct the first terminal device to release or reconfigure the first AM MRB.

[0211] Furthermore, method 400 also includes:

[0212] The target node caches data packets of the first service that the target node has sent but the source node has not sent.

[0213] Optionally, method 400 also includes:

[0214] S407, the source node determines that the transmission progress of the first AM MRB is faster than the progress of the target node in sending the data packet of the first service to the second terminal device.

[0215] The source node can determine the transmission progress of the target node in the following ways:

[0216] Method 1: The target node reports its transmission progress by sending a switch request confirmation message.

[0217] Method 2: The source node determines the transmission progress of the target node through core network elements.

[0218] It should be understood that the embodiments of this application do not limit the method by which the source node determines the transmission progress of the target node. Any method of this application that determines the transmission progress of the target node in a manner other than the two methods mentioned above should fall within the protection scope of this application.

[0219] S408, the source node instructs the first terminal device to reconfigure the first AM MRB.

[0220] Specifically, when the source node determines that the target node's transmission progress is slower than the first AM MRB's transmission progress, the source node can instruct the first terminal device to reconfigure the first AM MRB. After the first terminal device completes the reconfiguration of the first AM MRB, it can perform a node switching operation. For example, if the first terminal device has already received the first 500 data packets of the first service through the first AM MRB, and the target node has already sent the first 400 data packets of the first service to the second terminal device, then the target node's transmission progress of the first service is slower than the first AM MRB's transmission progress, and the source node can instruct the first terminal device to reconfigure the first AM MRB.

[0221] Alternatively, S407 and S408 can be determined and indicated by the target node. For example, if the target node determines that the transmission progress of the first AMMRB is faster than the progress of the data packets of the first service sent by the target node to the second terminal, the target node can instruct the first terminal device to reconfigure the first AMMRB. In this embodiment, when a terminal device configured with the first AMMRB switches nodes, the source node and the target node can select different transmission schemes according to the transmission progress of the first AMMRB and the transmission progress of the target node, avoiding data packet loss caused by node switching and improving user experience.

[0222] The following is combined with Figure 5 The communication method provided in this application is described in detail. Figure 5 This is a schematic flowchart of a communication method 500 according to an embodiment of this application. The method 500 can be applied to... Figure 2 In the scenario shown, for example, a terminal device simultaneously receives unicast and multicast services.

[0223] S501, the first access network device receives third information sent by the terminal device, the third information being used to indicate the resources used by the terminal device to receive multicast services or the ability to support receiving multicast services.

[0224] Correspondingly, the terminal device sends third information to the first access network device.

[0225] It should be noted that the ability to receive multicast services can be understood as the ability of a terminal device to receive multicast services independently, as well as the ability of a terminal device to receive multicast services when it simultaneously receives unicast and multicast services.

[0226] Specifically, the first access network device can receive third information sent by the terminal device, so that the first access network device can configure the data radio bearer for unicast services for the terminal device according to the third information.

[0227] The third piece of information includes the number of Robust Header Compression Contexts (ROHC-Context) used for receiving multicast services and / or the number of Ethernet Header Compression Contexts (Ethernet-Context) and / or the number of MRBs or logical channels (LCH).

[0228] It should be noted that the resources used by a terminal device to receive multicast services can be understood as the resources that the terminal device is currently using to receive multicast services; or

[0229] The resources used by a terminal device to receive multicast services can be understood as the resources occupied by the terminal device when it wants to receive multicast services; or

[0230] The resources used by a terminal device to receive multicast services can be understood as the resources that the terminal device supports in receiving multicast services.

[0231] Terminal devices can send third-party information in the following ways:

[0232] Option 1: The third information can be included in the MBS interest indicator signaling.

[0233] Method 2: The terminal device can send third information independently.

[0234] Method 3: The third information can be included in the UE assistance information signaling.

[0235] Method four: The third information can be included in the UECapabilityInformation signaling.

[0236] It should be understood that the embodiments of this application do not limit the resources used by the terminal device to send and receive multicast services or the ability to support receiving multicast services. Any method of implementing this application in a manner other than the four methods mentioned above shall fall within the protection scope of this application.

[0237] S502, the first access network device configures a data radiobearer (DRB) to the terminal device according to the third information. The DRB is used to carry unicast services.

[0238] Specifically, after receiving the third information, the first access network device can determine the resources available for the terminal device to use multicast services or its ability to receive multicast services based on the third information. Then, based on the terminal device's resources available for using multicast services or its ability to receive multicast services, combined with the terminal device's capabilities, it can configure a DRB for the terminal device to carry unicast services.

[0239] Specifically, network devices can configure the maximum number of Rohc-Context and / or EHC-Context and / or LCH available for each DRB for terminal devices.

[0240] For example, if the third information indicates that the terminal device is receiving LCH 15 for multicast services, and since the total number of LCHs is 32, then the first access network device can determine that the number of LCHs used for the DRB for unicast services is 17.

[0241] For example, if the third information indicates that the maximum number of ROHC-Contexts supported by the terminal device when receiving multicast services is 50, and the terminal device reports that the maximum number of ROHC-Contexts it supports is 100, then the first access network device can determine that the number of ROHC-Contexts for the DRB of the unicast service is 50.

[0242] Optionally, in some embodiments, before the terminal device sends the third information, method 500 further includes:

[0243] S503, the second access network device sends multicast service data to the terminal device.

[0244] Specifically, the terminal device receives multicast service data sent to it by the second access network device, thereby determining the resources currently being used to receive multicast services.

[0245] It should be understood that in steps S501-S503 above, (1) the first access network device can be a unicast access network device; (2) the second access network device can be a multicast access network device or a broadcast access network device. For ease of understanding of the communication method provided in this application, the following, as an example and not a limitation, assumes that the first access network device is a unicast access network device, the second access network device is a multicast access network device, and the third information is sent via method one or method two, as shown below. Figure 6 The specific example methods shown will provide a detailed explanation of S501-S503 in method 500.

[0246] It should be noted that some of the steps mentioned below are the same as those in Method 500 above. The relevant details will not be repeated here. For the specific process, please refer to the relevant steps in Method 500.

[0247] S601, the unicast access network device receives third information sent by the terminal device, which is used to indicate the resources used by the terminal device to receive multicast services.

[0248] Correspondingly, the terminal device sends third information to the unicast access network device.

[0249] Specifically, unicast access network devices can receive third information sent by terminal devices, so that the unicast access network devices can configure DRBs for unicast services for terminal devices based on the third information.

[0250] The third information includes the number of ROHC-Contexts used for receiving multicast services and / or the number of Ethernet header compression contexts and / or the number of MRBs or LCHs (logical channels, LCHs).

[0251] The resources used by a terminal device to receive multicast services can be understood as the resources that the terminal device is currently using to receive multicast services; or

[0252] The resources used by a terminal device to receive multicast services can be understood as the resources occupied by the terminal device when it wants to receive multicast services; or

[0253] The resources used by a terminal device to receive multicast services can be understood as the resources that the terminal device supports in receiving multicast services.

[0254] It is understandable that the third piece of information, including the number of ROHC-Contexts used to receive multicast services, can be interpreted as the number of ROHC-Contexts that the terminal device is currently using to receive multicast services; or

[0255] The resources used by a terminal device to receive multicast services can be understood as the number of ROHC-Contexts that the terminal device occupies when it wants to receive multicast services; or

[0256] The resources used by a terminal device to receive multicast services can be understood as the number of ROHC-Contexts that the terminal device supports for receiving multicast services.

[0257] For a description of the third information, including the number of Ethernet-Contexts and / or the number of MRBs or LCHs used for receiving multicast services, please refer to the above text, which will not be repeated here for the sake of brevity.

[0258] S602, the unicast access network device configures the DRB to the terminal device according to the third information, and the DRB is used to carry unicast services.

[0259] Specifically, the unicast access network device can determine the resources used by the terminal device for multicast services based on third-party information. Therefore, the unicast access network device can determine the resources used for unicast services based on the terminal device's capabilities. The terminal device's capabilities can be understood as its ability to receive both multicast and unicast services. For example, the terminal device can use 100 ROHC-Contexts to receive both unicast and multicast services.

[0260] S603, the multicast access network device sends multicast service data to the terminal device.

[0261] For a description of S603, please refer to the description of S503. For the sake of brevity, it will not be repeated here.

[0262] Unicast access network devices can determine the capabilities of terminal devices in the following ways.

[0263] Method 1: The terminal device reports its capabilities to the unicast access network device.

[0264] Method 2: Unicast access network equipment determines the capabilities of terminal equipment through core network elements or other access network equipment.

[0265] For method 1, before the terminal device sends the third information, method 600 further includes:

[0266] S604, Unicast access network devices send capability query information to terminal devices.

[0267] Correspondingly, the terminal device receives capability query information sent by the unicast access network device.

[0268] S605, the terminal device sends capability information to the unicast access network device.

[0269] Correspondingly, unicast access network devices receive capability information sent by terminal devices.

[0270] Specifically, this capability information includes the terminal device's ability to receive multicast and unicast services.

[0271] For example, a unicast access network device requests the terminal device's ability to receive unicast and multicast services through UECapalibityEnquiry signaling, and the terminal device reports its ability to support unicast and multicast services to the unicast access network device through UECapabilityInformation signaling.

[0272] In this embodiment, the terminal device reports resource information for multicast services to the unicast access network device, thereby enabling the first access network device to configure a DRB for unicast services for the terminal device based on the resources of multicast services and the capabilities of the terminal device, ensuring that the PDCP capabilities of the terminal device are not exceeded.

[0273] The above method 600 is introduced by sending the third information through method one or method two. The following will describe sending the third information through method four and combining it with... Figure 7 The steps S501-S502 in method 500 are described in detail.

[0274] It should be noted that some of the steps mentioned below are the same as those in methods 500 and 600 above. The relevant details will not be repeated here. For the specific process, please refer to the relevant steps in methods 500 and 600.

[0275] S701, unicast access network devices send capability query information to terminal devices.

[0276] Correspondingly, the terminal device receives capability query information sent by the unicast access network device.

[0277] Specifically, this capability query information is used to request the terminal device's ability to support multicast services.

[0278] S702, the terminal device sends capability information to the unicast access network device, which includes third information.

[0279] Response rate refers to the ability of a unicast access network device to receive information sent by a terminal device.

[0280] S703, the unicast access network device configures the DRB to the terminal device according to the third information, and the DRB is used to carry unicast services.

[0281] In one possible implementation, the capability query information sent by the unicast access network device is also used to request the terminal device's capability to support unicast services. Correspondingly, the capability information sent by the terminal device indicates that the terminal device supports unicast capabilities. Thus, the unicast access network device can configure the DRB to carry unicast services for the terminal device based on the terminal device's capability to support multicast services. For example, if the terminal device reports 25 ROHC-Contexts to support multicast services and 75 ROHC-Contexts to support unicast services, then the number of ROHC-Contexts used by the unicast access network device when configuring unicast services for the terminal device cannot exceed 75.

[0282] In this possible implementation, the terminal device can report its capabilities for supporting multicast and unicast services separately in its capability information. It can be understood that the sum of the terminal device's capabilities for supporting multicast and unicast services represents the terminal device's total service reception capability. For example, if the terminal device supports 25 ROHC-Contexts for multicast services and 75 ROHC-Contexts for unicast services, then the terminal device has a total of 100 ROHC-Contexts for receiving both unicast and multicast services.

[0283] In another possible implementation, the capability query information sent by the unicast access network device is also used to request the terminal device's total capability to support unicast and multicast services. Correspondingly, the capability information sent by the terminal device indicates its total capability to support both unicast and multicast services. Thus, the unicast access network device can configure a DRB for carrying unicast services for the terminal device based on the difference between the terminal device's total capability and its multicast service support capability. For example, if the terminal device reports a maximum supported ROHC-Context number of 100, and reports a ROHC-Context number of 25 for multicast services, then the unicast access network device cannot use more than 75 ROHC-Contexts when configuring unicast services for the terminal device.

[0284] It should be noted that in the embodiments of this application, methods one through four are not limited to being implemented individually; methods one through four can be combined arbitrarily. For example, the terminal device can send third information through methods one and two.

[0285] In this embodiment, the terminal device reports its ability to support multicast services to the unicast access network device, so that the first access network device can configure a DRB for unicast services for the terminal device according to the terminal device's ability to support multicast services, ensuring that the PDCP capability of the terminal device is not exceeded.

[0286] It should be noted that the above methods 500-700 take the terminal device receiving services from unicast access network equipment and multicast access network equipment as an example. However, the embodiments of this application are not limited to this. The terminal device can also receive unicast and multicast services from one access network equipment. The following example uses the case where the first access network sends unicast services and the second access network sends multicast services, and the first and second access networks belong to the same access network equipment. Figure 8 This application provides a schematic flowchart illustrating another communication method. The first access network and the second access network belonging to the same access network device can be understood as the first access network and the second access network being provided by the same access network device.

[0287] Some of the steps mentioned below are the same as those in methods 500-700 above. The relevant details will not be repeated here. For the specific process, please refer to the relevant steps in method 500-700.

[0288] S801, the access network device receives third information sent by the terminal device, the third information being used to indicate the resources used by the terminal device to receive multicast services or the capability to support receiving multicast services.

[0289] For a description of the third piece of information, please refer to the above text. For the sake of brevity, it will not be repeated here.

[0290] S802, the access network equipment configures the DRB to the terminal equipment according to the third information, and the DRB is used to carry unicast services.

[0291] In this embodiment, the terminal device reports its ability to support multicast services or receives resources used for multicast services to the access network device. As a result, the access network device can configure a DRB for unicast services for the terminal device based on the terminal device's ability to support multicast services or the resources used for multicast services, ensuring that the PDCP capability of the terminal device is not exceeded.

[0292] Optionally, in some embodiments, before the terminal device sends the third information, method 800 further includes:

[0293] S803, the access network device sends multicast service data to the terminal device.

[0294] The above methods 500-800 take the terminal device reporting the resources used to receive multicast services or the ability to support the use of multicast services as an example. Another communication method provided by this application will be introduced below.

[0295] S1, the access network device receives multicast service indication information sent by the terminal device, which is used to instruct the terminal device to receive multicast services.

[0296] Correspondingly, the terminal device sends multicast service instruction information to the access network device.

[0297] One possible implementation is to include multicast service indication information in the MBS interest indicator signaling.

[0298] One possible implementation is that the terminal device can send multicast service indication information separately.

[0299] S2, the access network equipment configures the PDCP resource threshold for the terminal equipment.

[0300] Specifically, when an access network device receives a multicast service indication message, it can configure a threshold for the PDCP resources of the terminal device.

[0301] S3, when the terminal device receives PDCP resources used by multicast and / or unicast services and the threshold is reached, the terminal device sends an indication message, which is used to indicate the reconfiguration of PDCP resources.

[0302] Specifically, when the PDCP resources used by the unicast and / or multicast services received by the terminal device reach a threshold, the terminal device can send an indication message to the access network device to instruct it to reconfigure PDCP resources. For example, taking the PDCP resources of the terminal device as the number of ROHC-Contexts, the total number of ROHC-Contexts of the terminal device is 100, and the threshold is 90 or 90%. When the ROHC-Contexts used by the unicast and / or multicast services received by the terminal device reach 90, it can send an indication message to the access network device.

[0303] Alternatively, in some embodiments, when the PDCP resources used by the terminal device to receive multicast and / or unicast services are ≥ N% of the threshold, the terminal device sends an indication message, where 0 ≤ N ≤ 100. For example, taking the PDCP resources of the terminal device as the number of ROHC-Contexts, the total number of ROHC-Contexts of the terminal device is 100, the threshold is 90, and N = 90. When the number of ROHC-Contexts used by the terminal device to receive unicast and / or multicast services reaches 81, it can send an indication message to the access network device.

[0304] S4, the access network device sends reconfiguration information to the terminal device, which instructs the terminal device to reconfigure PDCP resources.

[0305] Specifically, after receiving the indication information sent by the terminal device, the access network device determines that the terminal device's PDCP resource usage has reached the threshold, and can then instruct the terminal device to reconfigure PDCP resources. For example, taking the terminal device's PDCP resources as the number of ROHC-Contexts as an example, the terminal device has a total of 100 ROHC-Contexts, and the threshold is 70. The terminal device includes a first DRB and a second DRB. The first DRB can use 50 ROHC-Contexts, and the second DRB can use 50 ROHC-Contexts. The first DRB is used to carry the first service and uses 50 ROHC-Contexts, while the second DRB is used to carry the second service and uses 20 ROHC-Contexts. Since the ROHC-Context used by the first DRB and the second DRB has reached the threshold, the terminal device sends an indication message indicating the resource usage of the first DRB and the second DRB (for example, the ROHC-Context used by the first DRB is 50 and the ROHC-Context used by the second DRB is 20). After receiving the indication message, the access network device can instruct the terminal device to reconfigure PDCP resources so that the ROHC-Context resources of the second DRB become 20, and the remaining ROHC-Context can be used to receive multicast and / or unicast services.

[0306] In some embodiments, the access network device may be a unicast access network device.

[0307] In this embodiment, the access network device sets a threshold for PDCP resources. When the PDCP resources used by the terminal device exceed the threshold, the access network device can dynamically adjust the PDCP resources, thereby avoiding conflicts between multiple services.

[0308] It should be noted that methods 500 to 800 use the example of a terminal device sending resources used for receiving multicast services or the ability to support receiving multicast services to an access network device. However, this application is not limited to this. This application also provides a communication method in which the terminal device can send resources used for receiving unicast services or the ability to support receiving unicast services to the access network device, so that the access network device can configure the MRB to carry multicast services for the terminal device. This communication method can be applied to... Figure 2 In the scenario shown, the method includes:

[0309] S1, the first access network device receives the fourth information sent by the terminal device, the fourth information being used to indicate the resources used by the terminal device to receive unicast services or the ability to support receiving unicast services.

[0310] Correspondingly, the terminal device sends the fourth information to the first access network device.

[0311] It should be noted that the ability to receive unicast services can be understood as the ability of a terminal device to receive unicast services independently, as well as the ability of a terminal device to receive unicast services when it simultaneously receives unicast and multicast services.

[0312] Specifically, the first access network device can receive the fourth information sent by the terminal device, so that the first access network device can configure the MRB for multicast services for the terminal device according to the fourth information.

[0313] The way the first access network device receives the fourth information is similar to the way it receives the third information, and for the sake of simplicity, it will not be described in detail here.

[0314] S2, the first access network device configures the MRB to the terminal device according to the fourth information. The MRB is used to carry multicast services.

[0315] It should be understood that the first access network configuring the MRB to the terminal device based on the fourth information is similar to the first access network configuring the DRB to the terminal device based on the third information. For the sake of simplicity, it will not be elaborated here.

[0316] For example, if the fourth information indicates that the maximum number of ROHC-Contexts supported by the terminal device when receiving unicast services is 50, and the terminal device reports that the maximum number of ROHC-Contexts it supports is 100, then the first access network device can determine that the number of ROHC-Contexts of the MRB for multicast services is 50.

[0317] In this embodiment, the terminal device reports resource information for unicast services to the access network device, thereby enabling the first access network device to configure an MRB for multicast services for the terminal device based on the unicast service resources and the terminal device's capabilities, ensuring that the PDCP capabilities of the terminal device are not exceeded.

[0318] It is understood that the technical solution of the aforementioned terminal device reporting the resources used by the terminal device to receive unicast services or the ability to support receiving unicast services, so that the access network device can configure the MRB to carry multicast services to the terminal device, is similar to method 500-800. For detailed technical details, please refer to method 500-800.

[0319] Due to LCH multiplexing and the use of G-RNTI scrambling for retransmissions when using C-RNTI scrambling, terminal devices may be unable to map data to the correct RB. For example, when a terminal device receives a data packet that was initially scrambled with G-RNTI for a retransmission using C-RNTI scrambling, it can obtain the LCH identifier after descrambling with C-RNTI. If the LCH is multiplexed for multiple multicast services, the terminal needs to match the LCH identifier with the G-RNTI to determine which MRB or multicast service the retransmitted data packet belongs to. If the corresponding G-RNTI cannot be found based on the LCH identifier, the terminal device cannot determine the service corresponding to the retransmitted data packet because the LCH corresponds to multiple service G-RNTIs. For example, when a terminal device receives a data packet that was scrambled with G-RNTI during the initial transmission and then retransmitted using C-RNTI, the terminal device can obtain the LCH identifier after descrambling with C-RNTI. If the LCH is multiplexed with both C-RNTI and G-RNTI, the terminal needs to match the LCH identifier with the G-RNTI to determine which MRB or DRB the retransmitted data packet belongs to. If the corresponding G-RNTI cannot be found based on the LCH identifier, the terminal device cannot determine the RB corresponding to the data packet based on the LCH identifier, and therefore cannot determine the service corresponding to the data packet. For example, a first multicast service corresponds to a first G-RNTI, a first LCH, and a second multicast service corresponds to a second G-RNTI. When the first data packet of the first multicast service fails to transmit and is scrambled and retransmitted using C-RNTI, the terminal device, upon receiving the retransmitted data packet, can parse it to determine that the LCH corresponding to the first data packet is the first LCH. However, since the G-RNTI cannot be determined, the terminal device cannot determine whether the first data packet corresponds to the first or second multicast service. As another example, a first LCH corresponds to a first C-RNTI and a first G-RNTI, a first multicast service corresponds to a first G-RNTI, and a first unicast service corresponds to a C-RNTI. When the first data packet of the first multicast service fails to transmit and is scrambled and retransmitted using C-RNTI, the terminal device obtains the LCH corresponding to the first data packet as the first LCH through the C-RNTI. However, since the first G-RNTI cannot be determined, the terminal device cannot determine whether the first data packet corresponds to the first multicast or first unicast service.

[0320] Based on this, the following is combined with Figure 9 The communication method provided in this application is described in detail. Figure 9 This is a schematic flowchart of a communication method 900 according to an embodiment of this application. The method 900 can be applied to... Figure 2 In the scene shown.

[0321] S901, the third access network device uses the first G-RNTI to send a first data packet to the terminal device, and the first data packet corresponds to the first LCH.

[0322] Correspondingly, the terminal device receives the first data packet sent by the third access network device using the first G-RNTI.

[0323] Sending the first data packet using the first G-RNTI can be understood as the third access network device scrambling the first data packet with the first G-RNTI and then sending it.

[0324] S902, when the first preset condition is met, the third access network device uses C-RNTI to retransmit the first data packet.

[0325] Correspondingly, the terminal device receives the first data packet retransmitted by the third access network device using C-RNTI.

[0326] The third access network device using C-RNTI to retransmit the first data packet can be understood as the third access network device using C-RNTI to scramble and retransmit the first data packet.

[0327] S903, when the second preset condition is met, the third access network device uses the first G-RNTI to retransmit the first data packet.

[0328] Optionally, in some embodiments, the first preset condition is that the third access network device receives the NACK feedback of the first data packet, or the first LCH does not multiplex multiple RNTIs.

[0329] It should be understood that the absence of multiple RNTI multiplexing in the first LCH includes: the absence of multiple G-RNTI multiplexing in the first LCH, or the absence of one C-RNTI and at least one G-RNTI multiplexing in the first LCH.

[0330] Furthermore, in some embodiments, the first preset condition is that the first LCH does not reuse multiple G-RNTIs.

[0331] Specifically, the first preset condition can be that the third access network device receives a NACK feedback for the first data packet. When the third access network device receives a NACK feedback for the first data packet, it indicates that the terminal device has received the first data packet sent using the first G-RNTI in a HARQ process but has not successfully decoded it. In this case, the terminal device has determined that the G-RNTI corresponding to the first data packet is the first G-RNTI or the specific service corresponding to the first data packet. Then, the third access network device can use the C-RNTI to retransmit the first data packet.

[0332] For example, a first multicast service corresponds to a first G-RNTI, a first LCH, and a second multicast service, which in turn corresponds to a second G-RNTI. When a terminal device receives a first data packet from a third access network device using the first G-RNTI for the first multicast service but fails to decode it, it sends a NACK to the third access network device. However, the terminal device has already determined that the first data packet corresponds to the first G-RNTI. After receiving the NACK, the third access network device can retransmit the first data packet using a C-RNTI. When the terminal device receives the retransmitted first data packet using the C-RNTI, it decodes the retransmitted first data packet to obtain the LCH identifier, and then determines the service corresponding to the first data packet as the first multicast service based on the LCH identifier and the first G-RNTI.

[0333] Specifically, the first preset condition can also be that the first LCH does not have a C-RNTI and at least one G-RNTI multiplexed. When the first LCH carrying the first multicast service does not have a C-RNTI and at least one G-RNTI multiplexed, that is, the first LCH does not correspond to a C-RNTI and at least one G-RNTI, the third access network device can use the C-RNTI to retransmit the first data packet to the terminal device. After receiving the first data packet retransmitted using the C-RNTI, the terminal device uses the C-RNTI to descramble and obtain the LCH identifier of the first LCH, and then submits the first data packet to the corresponding higher layer, such as the RLC layer or the PDCP layer.

[0334] For example, the first multicast service corresponds to the first G-RNTI and the first LCH. When the terminal device does not receive the first data packet of the first multicast service sent by the third access network device using the first G-RNTI, and the first LCH does not have multiplexing of G-RNTI and C-RNTI, the third access network device can retransmit the first data packet to the terminal device using C-RNTI. When the terminal device receives the first data packet retransmitted using C-RNTI, it decodes the retransmitted first data packet to obtain the LCH identifier, and then determines the service corresponding to the first data packet as the first multicast service based on the LCH identifier.

[0335] Specifically, the first preset condition can also be that the first LCH does not have multiple G-RNTI multiplexing. When the first LCH carrying the first multicast service does not have multiple G-RNTI multiplexing, that is, the first LCH does not correspond to multiple G-RNTIs, the third access network device can use C-RNTI to retransmit the first data packet to the terminal device. After receiving the first data packet retransmitted using C-RNTI, the terminal device uses C-RNTI to descramble and obtain the LCH identifier of the first LCH, and then submits the first data packet to the corresponding higher layer, such as the RLC layer or PDCP layer.

[0336] For example, the first multicast service corresponds to the first G-RNTI and the first LCH. When the terminal device does not receive the first data packet of the first multicast service sent by the third access network device using the first G-RNTI, and the first LCH does not have G-RNTI multiplexing, the third access network device can retransmit the first data packet to the terminal device using C-RNTI. When the terminal device receives the first data packet retransmitted using C-RNTI, it decodes the retransmitted first data packet to obtain the LCH identifier, and then determines the service corresponding to the first data packet as the first multicast service based on the LCH identifier.

[0337] In this embodiment, the third access network device will only use C-RNTI to scramble and retransmit the data packets scrambled with R-RNTI during the initial transmission when it receives a NACK from the terminal device for the data packets sent by the third access network device using G-RNTI, or when the third access network device determines that the terminal device does not have LCH multiplexing. This avoids the terminal device being unable to distinguish which RB or service the HARQ retransmitted data packets belong to based solely on the LCH identifier, effectively avoiding conflicts between the two and ensuring communication quality.

[0338] Optionally, in some embodiments, the second preset condition is that the third access network device does not receive the NACK feedback of the first data packet or the timer times out, and the first LCH has multiple RNTI multiplexing.

[0339] Optionally, in some embodiments, the second preset condition is that the third access network device does not receive NACK feedback for the first data packet or the timer times out.

[0340] Specifically, the second preset condition is that the third access network device does not receive the NACK feedback for the first data packet or the timer times out. When the third access network device does not receive the NACK feedback for the first data packet or the timer times out, it indicates that the terminal device did not receive the first data packet sent using the first G-RNTI within one HARQ process. If the third access network device retransmits the first data packet using C-RNTI, and if the terminal device has LCH multiplexing of RNTI, the terminal device may not be able to distinguish which service the data packet belongs to. Therefore, the third access network device still uses the first G-RNTI to retransmit the first data packet.

[0341] For example, the first multicast service corresponds to the first G-RNTI, the first multicast service corresponds to the first LCH, the first LCH also corresponds to the second multicast service, and the second multicast service corresponds to the second G-RNTI. When the terminal device does not receive the first data packet of the first multicast service sent by the third access network device using the first G-RNTI, the third access network device cannot use C-RNTI to retransmit the first data packet, but still uses the first G-RNTI to retransmit the first data packet.

[0342] Specifically, the second preset condition is that the third access network device does not receive a NACK feedback for the first data packet or the timer times out, and multiple G-RNTIs are multiplexed in the first LCH. When the third access network device does not receive a NACK feedback for the first data packet or the timer times out, and it is determined that multiple G-RNTIs are multiplexed in the first LCH, if the third access network device retransmits the first data packet using C-RNTI, the terminal device will not be able to distinguish which service the data packet belongs to. Therefore, the third access network device will still use the first G-RNTI to retransmit the first data packet.

[0343] For example, if the first multicast service corresponds to the first G-RNTI and the first LCH, and the terminal device does not receive the first data packet of the first multicast service sent by the third access network device using the first G-RNTI, and the first LCH has G-RNTI multiplexing, then the third access network device cannot use C-RNTI to retransmit the first data packet, but still uses the first G-RNTI to retransmit the first data packet.

[0344] Specifically, the second preset condition is that the third access network device does not receive a NACK feedback for the first data packet or the timer times out, and the first LCH has C-RNTI and at least one G-RNTI multiplexed. When the third access network device does not receive a NACK feedback for the first data packet or the timer times out, and it is determined that the first LCH has C-RNTI and at least one G-RNTI multiplexed, if the third access network device retransmits the first data packet using C-RNTI, the terminal device will not be able to distinguish which RB the data packet belongs to, therefore the third access network device will still use the first G-RNTI to retransmit the first data packet.

[0345] For example, if the first multicast service corresponds to the first G-RNTI and the first LCH, and the terminal device does not receive the first data packet of the first multicast service sent by the third access network device using the first G-RNTI, and the first LCH has multiplexing of G-RNTI and C-RNTI, then the third access network cannot use C-RNTI to retransmit the first data packet, but still uses the first G-RNTI to retransmit the first data packet.

[0346] In this embodiment, when the terminal device does not receive new data transmitted using G-RNTI, or when the terminal device does not receive new data transmitted using G-RNTI and LCH multiplexing exists, the third access network device will not use C-RNTI for retransmission. This avoids the terminal device being unable to distinguish which RB or service the HARQ retransmitted data packet belongs to based solely on the LCH identifier, effectively avoiding conflicts between the two and ensuring communication quality.

[0347] The following is combined with Figure 10 The communication method provided in this application is described in detail. Figure 10 This is a schematic flowchart of a communication method 1000 according to an embodiment of this application. The method 1000 can be applied to... Figure 2 In the scene shown.

[0348] S1001, the terminal device receives the seventh indication information sent by the fourth access network device. The seventh indication information indicates whether the fourth access network device uses C-RNTI to scramble the data packets scrambled by G-RNTI during the initial transmission, or whether the terminal device's LCH corresponds to multiple RNTIs.

[0349] Correspondingly, the fourth access network device sends the seventh instruction information to the terminal device.

[0350] S1002, when the seventh indication information instructs the fourth access network device to use G-RNTI scrambled data packets for retransmission when using C-RNTI scrambling, the LCH of the terminal device does not correspond to multiple RNTIs.

[0351] Specifically, when the fourth access network device uses C-RNTI scrambling for retransmission and uses G-RNTI scrambling for the initial transmission, the terminal device's LCH does not correspond to multiple RNTIs, meaning that the terminal device will not have LCH multiplexing.

[0352] For example, the fourth access network device is used to transmit a first multicast service, which corresponds to a first LCH and a first G-RNTI. The first LCH also corresponds to a second multicast service, which corresponds to a second G-RNTI. When the fourth access network device fails to send the first data packet of the first multicast service using the first G-RNTI, before retransmitting the first data packet using the C-RNTI, the fourth access network device can instruct the terminal device to disable the multiplexing of the first LCH or instruct the retransmission of the first data packet through the seventh indication information, thereby ensuring that the terminal device can map the first data packet to the correct MRB.

[0353] One possible implementation: The fourth access network device directly instructs the terminal device to disable the multiplexing of the first LCH.

[0354] Another possible implementation: The fourth access network device indicates that it will use C-RNTI to retransmit data packets, thereby indirectly instructing the terminal device to disable the multiplexing of the first LCH.

[0355] S1003, when the seventh indication information indicates that the fourth access network device does not use C-RNTI scrambling for retransmission of the initial transmission but uses G-RNTI scrambling for the data packets, the LCH of the terminal device corresponds to multiple RNTIs.

[0356] Specifically, when the fourth access network device uses G-RNTI scrambled data packets instead of C-RNTI scrambling for retransmission of the initial transmission, the terminal device's LCH can correspond to multiple RNTIs, meaning that the terminal device can reuse LCH.

[0357] For example, the fourth access network device is used to transmit a first multicast service, which corresponds to a first LCH and a first G-RNTI. The first LCH also corresponds to a second multicast service, which corresponds to a second G-RNTI. When the fourth access network device fails to send the first data packet of the first multicast service using the first G-RNTI, it can also instruct the terminal device to maintain the multiplexing of the first LCH when retransmitting the first data packet using the first G-RNTI.

[0358] One possible implementation: The fourth access network device directly instructs the terminal device to maintain the multiplexing of the first LCH.

[0359] Another possible implementation: The fourth access network device indicates that it will use the first G-RNTI to retransmit the data packet, thereby indirectly instructing the terminal device to maintain the multiplexing of the first LCH.

[0360] S1004, when the seventh indication information indicates that the LCH of the terminal device corresponds to multiple RNTIs, the terminal device does not use C-RNTI to receive retransmitted data packets of data packets scrambled with G-RNTI during the initial transmission.

[0361] Specifically, when the fourth access network device indicates that the LCH of the terminal device can correspond to multiple G-RNTIs, that is, when the fourth access network device indicates that the LCH of the terminal device is multiplexed, the terminal device does not use C-RNTI to receive retransmitted data packets that were scrambled with G-RNTI during the initial transmission.

[0362] For example, the fourth access network device is used to transmit a first multicast service, which corresponds to a first LCH and a first G-RNTI. The first LCH also corresponds to a second multicast service, which corresponds to a second G-RNTI. When the fourth access network device instructs the terminal device to reuse the LCH, that is, to maintain the reuse of the first LCH, in order to avoid collisions, the terminal device does not use C-RNTI to receive retransmitted data packets that were scrambled with the first G-RNTI during the initial transmission.

[0363] One possible implementation: The fourth access network device directly instructs the terminal device to maintain the multiplexing of the first LCH.

[0364] Another possible implementation: The fourth access network device indicates that it will use the first G-RNTI to retransmit the data packet, thereby indirectly instructing the terminal device to maintain the multiplexing of the first LCH.

[0365] S1005, when the seventh indication information indicates that the LCH of the terminal device does not correspond to multiple RNTIs, the terminal device uses C-RNTI to receive the retransmitted data packet of the data packet scrambled with G-RNTI during the initial transmission.

[0366] Specifically, when the fourth access network device indicates that the terminal device's LCH does not correspond to multiple G-RNTIs, that is, when the fourth access network device indicates that the terminal device's LCH is not multiplexed, the terminal device uses C-RNTI to receive the retransmitted data packets of the data packets scrambled with G-RNTI during the initial transmission.

[0367] For example, the fourth access network device is used to transmit a first multicast service, which corresponds to a first LCH and a first G-RNTI. This first LCH also corresponds to a second multicast service, which corresponds to a second G-RNTI. When the fourth access network device instructs the terminal device that the LCH does not correspond to multiple G-RNTIs, i.e., it disables the multiplexing of the first LCH, the terminal device can use the C-RNTI to receive retransmitted data packets of the data packets scheduled by the first G-RNTI.

[0368] One possible implementation: The fourth access network device directly instructs the terminal device to disable the multiplexing of the first LCH.

[0369] Another possible implementation: The fourth access network device indicates that it will use C-RNTI to retransmit data packets, thereby indirectly instructing the terminal device to disable the multiplexing of the first LCH.

[0370] It should be understood that there is no specific order between S1002 and S1005.

[0371] Optionally, method 1000 also includes:

[0372] The terminal device sends an eighth indication message to the fourth access network device. The eighth indication message is used to indicate whether the terminal device supports receiving retransmitted data packets that were scrambled with G-RNTI during the initial transmission using C-RNTI.

[0373] In this embodiment of the application, through the instruction of the fourth access network device, the terminal device can receive retransmitted data packets that were initially scrambled with G-RNTI based on whether the LCH corresponds to multiple RNTIs or whether C-RNTI is used. This avoids the terminal device being unable to distinguish which RB or service the HARQ retransmitted data packet belongs to based solely on the LCH identifier, effectively avoiding conflicts between the two and ensuring communication quality.

[0374] Figure 11 and Figure 12 This is a schematic block diagram of a communication device provided for embodiments of this application. These devices can implement the functions of the terminal device or any access network device in the above method embodiments, and therefore can also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the device can be a terminal device or an access network device.

[0375] Figure 11 This is a schematic block diagram of a communication device provided in an embodiment of this application. The device 1100 includes a transceiver unit 1101, and optionally, it may also include a processing unit 1102.

[0376] When device 1100 is used to achieve Figure 3 In the method embodiment, when the terminal device functions as described, the transceiver unit 1101 is used to receive first indication information, which instructs the adjustment of the receiving window of the first PDCP entity when reconstructing the first Packet Data Aggregation Protocol (PDCP) entity. The processing unit 1102 is used to adjust the receiving window of the first PDCP entity according to the first indication information. Optionally, the processing unit 1102 is further used to deliver the data packets buffered by the first PDCP entity when the reordering timer is enabled.

[0377] When device 1100 is used to achieve Figure 3 In the method embodiment, when the source node functions, the transceiver unit 1101 is used to send first indication information to the terminal device. This first indication information instructs the receiving window of the first Packet Data Aggregation Protocol (PDCP) entity to be adjusted when rebuilding the first PDCP entity. The transceiver unit 1101 is also used to send handover request information to the target node. The transceiver unit 1101 is also used to receive handover request confirmation information sent by the target node.

[0378] When device 1100 is used to achieve Figure 3 In the method embodiment, when the target node is functioning, the transceiver unit 1101 is used to receive handover request information. The transceiver unit 1101 is also used to send handover request confirmation information to the source node.

[0379] When device 1100 is used to achieve Figure 4In the method embodiment, when the source node is functioning, the transceiver unit 1101 is used to send a handover request to the target node and to receive a handover request confirmation from the target node. The processing unit 1102 is used to instruct the first terminal device to reconfigure the first AM MRB when it is determined that the progress of the target node's transmission of the first service is slower than that of the first AM MRB.

[0380] When device 1100 is used to achieve Figure 4 In the method embodiment, when the target node is functioning, the transceiver unit 1101 is used to receive handover request information sent by the source node and also to send handover request confirmation information to the source node. The processing unit 1102 is used to instruct the first terminal device to configure a second AM MRB to transmit the data packets of the first service already transmitted by the target node when the progress of the target node's transmission of the first service is determined to be faster than the first AM MRB.

[0381] When device 1100 is used to achieve Figure 5 When the terminal device functions as described in the method embodiment, the transceiver unit 1101 is used to send third information to the first access network device. The third information is used to indicate the resources used by the terminal device to receive multicast services or the ability to support multicast services.

[0382] When device 1100 is used to achieve Figure 5 In the method embodiment, when the first access network device functions as described, the transceiver unit 1101 is used to receive third information sent by the terminal device. This third information indicates the resources used by the terminal device to receive multicast services or its ability to support multicast services. The processing unit 1102 is used to configure a DRB for the terminal device based on the third information. This DRB is used to carry unicast services.

[0383] When device 1100 is used to achieve Figure 8 When the third access network device in the method embodiment functions as described above, the transceiver unit 1101 is used to send a first data packet sent using the first G-RNTI to the terminal device. The processing unit 1102 is used to retransmit the first data packet using C-RNTI when a first preset condition is met; and to retransmit the first data packet using the first G-RNTI when a second preset condition is met.

[0384] When device 1100 is used to achieve Figure 8 In the method embodiment, when the terminal device functions as described, the transceiver unit 1101 is used to receive a first data packet sent by a third access network device using a first G-RNTI.

[0385] When device 1100 is used to achieve Figure 9When the fourth access network device functions as described in the method embodiment, the transceiver unit 1101 is used to send a seventh indication information to the terminal device. The seventh indication information indicates whether the fourth access network device uses C-RNTI to schedule the retransmission of data packets scheduled by G-RNTI, or whether the logical channel of the terminal device corresponds to multiple G-RNTIs.

[0386] When device 1100 is used to achieve Figure 9 In the method embodiment, when the terminal device functions as described, the transceiver unit 1101 is used to receive a seventh indication information sent by the fourth access network device. This seventh indication information indicates whether the fourth access network device uses C-RNTI to schedule retransmission data packets scheduled by G-RNTI, or whether the terminal device's logical channel corresponds to multiple G-RNTIs. The processing unit 1102 is used to handle situations where, when the seventh indication information indicates that the fourth access network device uses C-RNTI to schedule retransmission data packets scheduled by G-RNTI, the terminal device's logical channel does not correspond to multiple G-RNTIs; or, when the seventh indication information indicates that the fourth access network device does not use C-RNTI to schedule retransmission data packets scheduled by G-RNTI, the terminal device's logical channel corresponds to multiple G-RNTIs; or, when the seventh indication information indicates that the terminal device's logical channel corresponds to multiple G-RNTIs, the terminal device does not use C-RNTI to receive retransmission data packets scheduled by G-RNTI; or, when the seventh indication information indicates that the terminal device's logical channel does not correspond to multiple G-RNTIs, the terminal device uses C-RNTI to receive retransmission data packets scheduled by G-RNTI.

[0387] For a more detailed description of the transceiver unit 1101 and the processing unit 1102, please refer to the relevant descriptions in the above method embodiments 300 to 900, which will not be repeated here.

[0388] Figure 12 A schematic block diagram of an apparatus 1200 applying an embodiment of this application is shown. Any access network device and terminal device involved in any of the methods 300 to 900 described above can be provided by... Figure 12 The device shown is used to achieve this.

[0389] It should be understood that device 1200 may be a physical device, a component of a physical device (e.g., an integrated circuit, a chip, etc.), or a functional module in a physical device.

[0390] like Figure 12As shown, the device 1200 includes one or more processors 1201. The processor 1201 can store execution instructions for performing the methods of the embodiments of this application. Optionally, the processor 1201 can invoke an interface to implement receiving and transmitting functions. The interface can be a logical interface or a physical interface, without limitation. For example, the interface can be a transceiver circuit or an interface circuit. The transceiver circuit or interface circuit used to implement receiving and transmitting functions can be separate or integrated together. The aforementioned transceiver circuit or interface circuit can be used for reading and writing code / data, or it can be used for transmitting or relaying signals.

[0391] Optionally, the interface can be implemented using a transceiver. Optionally, the device 121200 may also include a transceiver 1203. The transceiver 1203 may be referred to as a transceiver unit, transceiver, transceiver circuit, or transceiver, etc., and is used to implement transceiver functions.

[0392] Optionally, the device 1200 may further include a memory 1202. This application embodiment does not specifically limit the deployment location of the memory 1202; the memory may be integrated into the processor or may be independent of the processor. In the case where the device 1200 does not include a memory, the device 1200 only needs to have processing capabilities, and the memory can be deployed in other locations (e.g., a cloud system).

[0393] The processor 1201, memory 1202 and transceiver 1203 communicate with each other through internal connection paths to transmit control and / or data signals.

[0394] It is understood that, although not shown, device 1200 may also include other devices, such as input devices, output devices, batteries, etc.

[0395] Optionally, in some embodiments, the memory 1202 may store execution instructions for performing the methods of the embodiments of this application. The processor 1201 may execute the instructions stored in the memory 1202 in conjunction with other hardware (e.g., transceiver 703) to complete the steps of the method execution shown below. For specific working processes and beneficial effects, please refer to the description in the method embodiments below.

[0396] The methods disclosed in this application can be applied to or implemented by processor 1201. Processor 1201 may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the method can be completed by integrated logic circuits in the processor's hardware or by instructions in software form. The processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software module can reside in a mature storage medium in the field, such as random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory, and the processor reads instructions from the memory and, in conjunction with its hardware, completes the steps of the above method.

[0397] It is understood that memory 1202 can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM), which serves as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0398] Furthermore, in this application, device 1100 is presented in the form of a functional module. Here, "module" can refer to an application-specific integrated circuit (ASIC), circuit, processor and memory executing one or more software or firmware programs, integrated logic circuit, and / or other devices that can provide the aforementioned functions. In a simple embodiment, those skilled in the art will understand that device 1100 can employ... Figure 11 The processing unit 1102 can be in the form shown. Figure 12 The processor 1201 shown is used for implementation. Optionally, if Figure 12 The computer device shown includes a memory 1202, and the processing unit 1102 can be implemented using a processor 1201 and the memory 1202. The transceiver unit 1101 can be implemented using... Figure 12The transceiver 1203 shown is used for implementation. The transceiver 1203 includes receiving and transmitting functions. Specifically, the processor implements this by executing a computer program stored in memory. Optionally, when the device 1100 is a chip, the function and / or implementation process of the transceiver unit 1203 can also be implemented through pins or circuits, etc. Optionally, the memory can be a storage unit within the chip, such as a register or cache, or the storage unit can be a storage unit located outside the chip within the computer device, such as... Figure 12 The memory 1202 may be a storage unit deployed in other systems or devices, not within the computer device. Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0399] Various aspects or features of this application can be implemented as methods, apparatus, or articles of manufacture using standard programming and / or engineering techniques. As used herein, the term "article of manufacture" encompasses a computer program accessible from any computer-readable device, carrier, or medium. For example, computer-readable media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks, or magnetic tapes), optical discs (e.g., compact discs (CDs), digital versatile discs (DVDs), etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memory (EPROMs), cards, sticks, or key drives, etc.). Additionally, the various storage media described herein may represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing, and / or carrying instructions and / or data.

[0400] This application also provides a computer-readable medium having a computer program stored thereon, which, when executed by a computer, implements the functions of any of the above method embodiments.

[0401] This application also provides a computer program product that, when executed by a computer, implements the functions of any of the above-described method embodiments. In the above embodiments, implementation can be achieved wholly or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented wholly or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., high-density digital video discs (DVDs)), or semiconductor media (e.g., solid-state disks (SSDs)).

[0402] It should be understood that the term "embodiment" used throughout the specification means that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, various embodiments throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0403] It should also be understood that in this application, “when…”, “if” and “if” all refer to the UE or base station taking corresponding actions under certain objective circumstances, and are not time-limited, nor do they require the UE or base station to perform a judgment action, nor do they imply any other limitations.

[0404] Furthermore, the terms "system" and "network" are often used interchangeably in this paper. The term "and / or" in this paper is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists alone, A and B exist simultaneously, and B exists alone.

[0405] In this document, the terms “at least one of…” or “at least one of…” refer to all or any combination of the listed items. For example, “at least one of A, B and C” can mean: A alone, B alone, C alone, A and B together, B and C together, and A, B and C together.

[0406] Unless otherwise specified in this application, "at least one" means one or more, and "multiple" means two or more.

[0407] It should be understood that in the embodiments of this application, "B corresponding to A" means that B is associated with A, and B can be determined based on A. However, it should also be understood that determining B based on A does not mean that B is determined solely based on A; B can also be determined based on A and / or other information.

[0408] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0409] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0410] In the several 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 units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0411] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0412] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0413] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they 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 a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a 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 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.

[0414] 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, The method is applied to a terminal device, the terminal device including a first multicast radio bearer (MRB), the first MRB including a first packet data aggregation protocol (PDCP) entity and a first radio communication protocol (RLC) entity, the first RLC entity employing acknowledgment mode (AM), the method including: The terminal device receives first indication information sent by the source node. The first indication information indicates that the receiving window of the first PDCP entity should be adjusted when rebuilding the first PDCP entity. The first indication information is included in first information used to indicate the switching node. The terminal device adjusts the receiving window of the first PDCP entity according to the first instruction information; The first indication information includes a second indication information, wherein the second indication information indicates that the regional session ID of the target node is inconsistent with the regional session ID of the source node; The terminal device adjusts the receiving window of the first PDCP entity according to the first indication information, including: The terminal device initializes the window parameters of the receiving window of the first PDCP entity based on the fact that the regional session ID of the target node is inconsistent with the regional session ID of the source node.

2. The method according to claim 1, characterized in that, The method further includes: When the reordering timer is started, the terminal device delivers the data packets cached by the first PDCP entity.

3. A communication method, characterized in that, The method includes: The source node sends a first indication message to the terminal device. The first indication message indicates that the receiving window of the first PDCP entity should be adjusted when rebuilding the first packet data aggregation protocol PDCP entity. The first indication message is included in the first information used to instruct the terminal device to switch nodes. The terminal device includes a first multicast radio bearer MRB. The first MRB includes a first PDCP entity and a first RLC entity. The first RLC entity adopts acknowledgment mode AM. The first PDCP entity is associated with the first RLC entity. The first indication information includes a second indication information, which is used to indicate that the regional session ID of the target node is inconsistent with the regional session ID of the source node; adjusting the receiving window of the first PDCP entity includes: initializing the window parameters of the receiving window of the first PDCP entity.

4. The method according to claim 3, characterized in that, Before the source node sends the first indication information to the terminal device, the method further includes: The source node sends a handover request to the target node; The source node receives a handover request confirmation message, which includes an indication message for adjusting the receive window of the first PDCP entity.

5. An apparatus, characterized in that, Includes modules or units for performing the method according to any one of claims 1 to 4.

6. An apparatus, characterized in that, Includes a processor for executing a computer program or instructions stored in a memory to cause the apparatus to perform the method of any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program or instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1 to 4.

8. A computer program product, characterized in that, The computer program product includes a computer program or instructions for performing the method as described in any one of claims 1 to 4.

9. A chip, characterized in that, The chip is coupled to a memory for reading and executing program instructions stored in the memory to implement the method as described in any one of claims 1 to 4.

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