Data processing method applied to dual-connection DC scene

Abstract

The invention provides a communication method applied to a dual-connection DC scene, and the method comprises the steps: a first network device and a second network device interact congestion auxiliary information, the first network device or the second network device comprehensively considers the network congestion condition, determines that activated / deactivated downlink data is discarded based on a PSI, and transmits the discarded data to the first network device or the second network device; or activating / deactivating the UE drop based on the PSI. According to the method, under the DC scene, the congestion capabilities of the two network devices are coordinated, and QoS guarantee is better provided for XR services.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wireless communication, and more particularly, to a data processing method applied to a dual connectivity (DC) scenario. BACKGROUND

[0002] Extended reality (XR) refers to various types of environments combining reality and virtuality generated by computing technology and wearable devices, as well as human-computer interaction, and specifically includes the following typical forms: augmented reality (AR), mixed reality (MR), and virtual reality (VR).

[0003] A 5G system is based on the granularity of a quality of service flow (QoS flow) to forward and process data and guarantee the quality of service (QoS). A 5G core network (5GC) in the 5G system indicates the QoS requirements of different QoS flows to a radio access network (RAN) through a QoS profile. For ordinary services of the 5G system, only protocol data units (PDUs) are used as the granularity to require QoS guarantee, but for XR services, it is usually expected to use PDU sets as the granularity to require QoS guarantee. A QoS flow is configured with PDU set integrated handling information (PSIHI), and the entire PDU set can be processed as a whole. If a PDU in the PDU set is lost, the remaining PDU packets in the PDU set can be considered as no longer needed by the XR service, and the remaining PDU data in the PDU set can be discarded to release wireless resources. When the network is congested, unimportant data packets can be discarded based on the importance of the protocol data unit set (PSI) to alleviate network congestion. In a dual-connectivity (DC) scenario, coordinating the PDU set processing capabilities of two network devices and processing PDU set packets, and the two network devices jointly guaranteeing the QoS of the XR service are technical problems to be solved. SUMMARY

[0004] The application provides a communication method applied to a dual connectivity (DC) scenario. In the DC scenario, the method can enable an access network device, including a master node (MN) and a secondary node (SN), to correctly process data packets of XR services, guarantee the QoS of the XR services, and improve service experience.

[0005] In a first aspect, a communication method applied to a dual connectivity (DC) scenario is provided. The method includes: a first network device receiving secondary information sent by a second network device, the secondary information being used for feeding back a radio resource congestion state of the second network device, and the secondary information including one or more of the following: an activation / deactivation suggestion based on PSI discard; a congestion state of the network device; a congestion level of the network device; an air interface rate that can be supported by the network device, etc. The first network device performs one or more of the following operations based on the secondary information: instructing a user equipment (UE) to activate / deactivate PSI-based discard; activating / deactivating downlink PSI-based discard; adjusting a split ratio of a split bearer; feeding back congestion information to a core network; adding an explicit congestion notification (ECN) to a data packet.

[0006] In combination with the first aspect, the first network device determines a congestion state condition of the first network device and the second network device, and the congestion state condition includes:

[0007] A first condition: the first network device is congested, and the second network device is congested;

[0008] A second condition: the first network device is congested, or the second network device is congested;

[0009] A third condition: the first network device is not congested, or the second network device is not congested;

[0010] A fourth condition: the first network device is not congested, and the second network device is not congested;

[0011] According to the first condition or the second condition, the UE is instructed to activate PSI-based discard; and according to the third condition or the fourth condition, the UE is instructed to deactivate PSI-based discard.

[0012] In combination with the first aspect, the secondary information is carried in an Xn interface message or a protocol data unit (PDU) header.

[0013] In combination with the first aspect, the first network device is a master node (MN) in the DC scenario, and the second network device is a secondary node (SN) in the DC scenario; or the first network device is a secondary node (SN) in the DC scenario, and the second network device is a master node (MN) in the DC scenario.

[0014] In the above scheme, the two network devices constituting the DC can update and interact the congestion information in time, and one of the network devices comprehensively considers the congestion situation between the two network devices to determine the network congestion relief action, ensuring the processing consistency between the two network devices and guaranteeing the QoS of the XR service.

[0015] In a second aspect, a method for two network nodes to interact PDU set processing capability is provided. The method comprises: a first network device receiving a PDU data packet from a core network, the PDU data packet carrying end of data burst indication information, the end of data burst indication information being used to indicate the end of data transmission of the data burst; and sending the end of data burst indication information to a second network device.

[0016] In combination with the second aspect, the sending of the end of data burst indication information to the second network device can be implemented by one or more of the following methods: forwarding the PDU data packet received from the core network, the PDU data packet carrying the end of data burst indication information; adding the end of data burst indication information in the PDU data packet forwarded to the second network device; and sending an empty PDU data packet carrying the end of data burst indication information to the second network device.

[0017] It should be understood that the beneficial effects of the scheme of the second aspect are similar to those of the first aspect, and will not be repeated here.

[0018] In a third aspect, another method for two network nodes to interact packet loss information in a handover scenario is provided. The method comprises, for a downlink data transmission scenario, a third network device sending a PDCP packet loss report to a UE, indicating that a first PDU or a first PDU set is discarded, and sending a handover command to the UE, indicating that the UE is switched from the third network device to a fourth network device. After receiving the handover command, the UE is switched to the fourth network device. The UE sends first state information to the fourth network device, indicating that the first PDU or the first PDU set has been received or confirmed.

[0019] In the fourth aspect, for uplink data, the UE sends a PDCP packet loss report to the third network device, indicating that the second PDU or the second PDU set is discarded. The third network device sends a handover command, indicating that the UE switches from the third network device to the fourth network device. After receiving the handover command, the UE switches to the fourth network device. The third network device sends the second state information to the fourth network device, indicating that the second PDU or the second PDU set has been received or confirmed. The third network device forwards the uplink data of the UE to the fourth network device. The fourth network device confirms that the second PDU or the second PDU set is not included in the uplink data forwarded by the third network device. The fourth network device considers that the second PDU or the second PDU set has been received or discarded, and the fourth network device does not start a reordering timer for the second PDU or the second PDU set.

[0020] In the fourth aspect, the fourth network device can send a third status report to the UE, indicating that the second PDU or the second PDU set has been received or confirmed. When the UE or the network device receives the PDCP packet loss report, for the data packet indicated as discarded, if the UE or the network device has received it, the indication in the packet loss report is ignored. When the UE or the network device receives the data packet, and the data packet has been indicated as discarded by the PDCP packet loss report, the UE or the network device saves the data packet and submits it to the upper layer after processing.

[0021] In the fifth aspect, the present application provides a processor for executing the method provided by any one of the implementation manners of the first aspect to the fourth aspect. In the process of executing these methods, the processes of sending and obtaining / receiving the information in the above-mentioned methods can be understood as the processes of outputting the information by the processor and the processes of receiving the input information by the processor. When outputting the information, the processor outputs the information to the interface, and transmits through the interface. After the information is output by the processor, it can also need to be processed before reaching the interface. Similarly, when the processor receives the input information, the interface obtains / receives the information and inputs it to the processor. Furthermore, after the interface receives the information, the information can need to be processed before being input to the processor.

[0022] For the operations of transmitting, sending, and obtaining / receiving involved, if there is no special description, or if it does not contradict the actual role or internal logic in the related description, it can be understood as outputting and receiving, inputting, and other operations, and can also be understood as the transmitting, sending, and receiving operations performed by the radio frequency circuit and the antenna, which are not limited in the present application.

[0023] In the implementation process, the processor can be a processor specially used for executing the methods, or a processor executing computer programs or instructions in a memory to execute the methods, such as a general-purpose processor. The memory can be a non-transitory memory, such as a read only memory (ROM), which can be integrated on the same chip as the processor, or can be separately arranged on different chips. The type of the memory and the arrangement mode of the memory and the processor are not limited in the embodiments of the present application.

[0024] In a sixth aspect, a computer readable storage medium is provided, which stores program codes for execution by a device, and the program codes include codes for executing the method provided in any of the implementation manners of the first aspect to the third aspect.

[0025] In a seventh aspect, a computer program product containing instructions is provided, which, when executed on a computer, causes the computer to execute the method provided in any of the implementation manners of the first aspect to the third aspect.

[0026] In an eighth aspect, a chip is provided, which includes a processor and a communication interface. The processor reads instructions stored on a memory through the communication interface, and executes the method provided in any of the implementation manners of the first aspect to the third aspect.

[0027] Optionally, as an implementation manner, the chip can further include a memory, which stores computer programs or instructions. The processor is configured to execute the computer programs or instructions stored on the memory, and when the computer programs or instructions are executed, the processor is configured to execute the method provided in any of the implementation manners of the first aspect to the third aspect. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a system architecture schematic diagram provided by an embodiment of the present application.

[0029] Figure 2 is a schematic diagram of a 5G system based on a QoS architecture provided by an embodiment of the present application.

[0030] Figure 3 is a control plane architecture schematic diagram of an MR-DC scenario.

[0031] Figure 4 is a schematic block diagram of a terminal device (for example, a UE) supporting EN-DC.

[0032] Figure 5 is a schematic block diagram of a terminal device (for example, a UE) supporting MR-DC.

[0033] Figure 6is a schematic block diagram of an MR-DC architecture supporting multiple bearer types.

[0034] Figure 7 is a schematic flow chart of a communication method provided by an embodiment of the present application applied to a dual connectivity (DC) scenario.

[0035] Figure 8 is a schematic flow chart of interaction of two network devices for auxiliary information provided by an embodiment of the present application applied to a dual connectivity (DC) scenario.

[0036] Figure 9 is a schematic flow chart of downlink packet loss data indication provided by an embodiment of the present application applied to a handover scenario.

[0037] Figure 10 is a schematic flow chart of uplink packet loss data indication provided by an embodiment of the present application applied to a handover scenario.

[0038] Figure 11 is a schematic block diagram of a communication apparatus provided by an embodiment of the present application.

[0039] Figure 12 is a schematic diagram of another communication apparatus provided by an embodiment of the present application.

[0040] Figure 13 is a schematic diagram of a chip system provided by an embodiment of the present application. DETAILED DESCRIPTION

[0041] The technical solutions in the present application will be described below with reference to the accompanying drawings.

[0042] First, in the present application, "for indicating" can include for directly indicating and for indirectly indicating. When describing that certain indication information is for indicating A, it can include that the indication information directly indicates A or indirectly indicates A, and does not mean that A must be carried in the indication information.

[0043] The information indicated by the indication information is referred to as to-be-indicated information, and there are many ways to indicate the to-be-indicated information in the specific implementation process, for example but not limited to, the to-be-indicated information can be directly indicated, such as the to-be-indicated information itself or an index of the to-be-indicated information. The to-be-indicated information can also be indirectly indicated by indicating other information, where the other information and the to-be-indicated information have an association relationship. The to-be-indicated information can also be only indicated in part, and the other part of the to-be-indicated information is known or agreed in advance. For example, the indication of a specific information can also be realized by means of the arrangement order of each information agreed in advance (for example, a protocol stipulates), thereby reducing the indication overhead to a certain extent. At the same time, the common part of each information can be identified and uniformly indicated, so as to reduce the indication overhead caused by separately indicating the same information.

[0044] Second, "at least one" in the present application means one or more, and "multiple" means two or more. In addition, in the embodiments of the present application, "first", "second", and various numbers (e.g., "#1", "#2", etc.) are only used for the convenience of description and do not limit the scope of the embodiments of the present application. The size of the serial number of each process below does not mean the order of execution, and the execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. It should be understood that the objects thus described can be interchanged under appropriate circumstances in order to describe solutions other than the embodiments of the present application. In addition, in the embodiments of the present application, "S210" and the like are only labels used for the convenience of description and do not limit the order of execution steps.

[0045] Third, in the embodiments of the present application, "exemplary" or "for example" is used to indicate an example, illustration or description. Any embodiment or design scheme described as "exemplary" or "for example" in the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, the use of "exemplary" or "for example" is intended to present the relevant concept in a specific manner.

[0046] Fourth, "save" in the embodiments of the present application can mean saving in one or more memories. The one or more memories can be separately provided or integrated in the encoder or decoder, processor, or communication device. The one or more memories can be partially separately provided and partially integrated in the decoder, processor, or communication device. The type of memory can be any form of storage medium, which is not limited in the present application.

[0047] Fifth, in the embodiments of the present application, "protocol" can refer to a standard protocol in the communication field, which can include NR protocol and related protocols applied to future communication systems, which is not limited in the present application.

[0048] Sixth, in the embodiments of the present application, "of", "corresponding", "corresponding" and "associated" can be used interchangeably at times, and it should be pointed out that their meanings are consistent when their differences are not emphasized.

[0049] Seventh, in the embodiments of the present application, "in the case of", "when", "if" can be used interchangeably at times, and it should be pointed out that their meanings are consistent when their differences are not emphasized.

[0050] Eighth, the term "and / or" in this document is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent three cases of A alone, A and B together, and B alone. In addition, the character " / " in this document generally represents an "or" relationship between the associated objects before and after it.

[0051] For ease of description, the system architecture of the embodiments of the present application is described in detail below.

[0052] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: global system for 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), universal mobile telecommunications system (UMTS), worldwide interoperability for microwave access (WiMAX) communication system, 5th Generation (5G) mobile communication system or new radio (NR), and future evolved communication system, etc. The present application does not limit this. Among them, the 5G mobile communication system can be non-standalone (NSA) or standalone (SA).

[0053] The technical solutions provided in the application can also be applied to machine type communication (MTC), long term evolution-machine (LTE-M), device-to-device (D2D) network, machine to machine (M2M) network, internet of things (IoT) network or other network. The IoT network may, for example, include a vehicle network. In the vehicle network system, the communication modes are collectively referred to as vehicle to X (V2X, X can represent any thing), for example, the V2X can include vehicle to vehicle (V2V) communication, vehicle to infrastructure (V2I) communication, vehicle to pedestrian (V2P) communication or vehicle to network (V2N) communication, and the like.

[0054] In the embodiments of the present application, the terminal device can also be referred to as user equipment (UE), mobile station (MS), mobile terminal (MT), etc., and refers to a device that provides voice and / or data connectivity to a user. For example, the terminal device can be a mobile phone, a tablet computer, a computer with wireless transceiver function, a mobile internet device (MID), a wearable device, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote medical treatment, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, a drone, a drone controller, etc. The embodiments of the present application do not limit the application scenarios. The terminal device also includes a device capable of sidelink (sidelink) communication, such as a vehicle-mounted terminal, or a handheld terminal capable of V2X (vehicle-to-everything) communication, etc. For the convenience of description, the terminal device will be described below by taking terminal or UE as an example.

[0055] The access network device refers to a radio access network (RAN) node (or device) that accesses the terminal to the wireless network, which can also be referred to as a base station, such as an NR gNB, an LTE eNB, etc. For the convenience of description, the embodiments of the present application uniformly refer to the "access network device" as "base station". Among them, the NR gNB can adopt a centralized unit (CU) and distributed unit (DU) separated architecture, such as the base station #1 shown in Figure 1 The CU and the DU are connected through the F1 interface for message transmission; or can adopt a CU and DU integrated architecture, such as Figure 1The base station #2 shown is not limited by embodiments of the present application. In a separate deployment scenario where the access network device includes a CU and a DU, the CU supports protocols such as radio resource control (RRC), packet data convergence protocol (PDCP), service data adaptation protocol (SDAP), etc.; and the DU mainly supports radio link control (RLC), media access control (MAC), and physical layer protocols. In a dual connectivity (DC) scenario, a terminal device can be connected to two base stations at the same time, one of which serves as a control anchor point and provides control plane connection and user plane connection for the terminal, referred to as a master base station, and the other of which only provides user plane connection for the terminal, referred to as a secondary base station.

[0056] The core network device refers to a device in a core network (CN) that provides service support for a terminal. Currently, some examples of core network devices are: access and mobility management function (AMF) entities, session management function (SMF) entities, user plane function (UPF) entities, and the like, which are not listed one by one here. Among them, the AMF entity can be responsible for access management and mobility management of the terminal; the SMF entity can be responsible for session management, such as session establishment of a user, etc.; and the UPF entity can be a functional entity of the user plane, mainly responsible for connecting external networks. It should be noted that the entity in the present application can also be referred to as a network element or a functional entity, for example, the AMF entity can also be referred to as an AMF network element or an AMF functional entity, and for another example, the SMF entity can also be referred to as an SMF network element or an SMF functional entity, etc.

[0057] The network device described above provides services for a cell, and a terminal device communicates with the cell through transmission resources (for example, frequency domain resources, or spectrum resources) allocated by the network device. The cell can belong to a macro base station (for example, a macro eNB or a macro gNB, etc.), or a base station corresponding to a small cell. The small cell here can include: a metro cell, a micro cell, a pico cell, a femto cell, etc., which have the characteristics of small coverage and low transmit power, and are suitable for providing high-speed data transmission services.

[0058] In this application, the device for implementing the functions of an access network device may be the access network device; it may also be a device capable of supporting the access network device in implementing the functions, such as a chip system, a hardware circuit, a software module, or a hardware circuit and a software module. The device may be installed in the access network device or may be used in conjunction with the access network device. In the technical solutions provided in this application, the technical solutions provided in this application are described by taking the device for implementing the functions of the access network device as the access network device, and the access network device as a base station as an example.

[0059] In the embodiment of the present application, a network device may include one or more cells, and each cell may include one or more transmission reception points (TRPs) or transmission points (TPs).

[0060] In order to facilitate understanding of the solutions of the embodiments of the present application, the technical terms involved in the embodiments of the present application will be described in detail below.

[0061] 1.PDU set

[0062] A collection of multiple data packets at the transport layer corresponds to the minimum granularity of data processing at the application layer. In some scenarios, the application layer can only correctly parse the corresponding data unit after correctly receiving all packets in a PDU set. In other scenarios, the application layer can only parse the corresponding data unit after correctly receiving a certain percentage of packets in the PDU set.

[0063] 2.XR business

[0064] Extended Reality (XR) refers to a variety of environments that combine real and virtual reality, as well as human-machine interactions, generated by computing technologies and wearable devices. XR specifically includes the following typical forms: AR, VR, and Mixed Reality (MR).

[0065] The 3rd Generation Partnership Project (3GPP) Rel-17 modeled and analyzed XR service characteristics. XR services typically generate data frames periodically at a certain frame rate. For example, an AR service with a 60fps (frames per second) frame generates 60 frames per second, or approximately every 16.67ms. A single video frame may be transmitted across multiple data packets, which may be grouped into one or more PDU sets.

[0066] 3. Quality of Service (QoS)

[0067] Quality of Service is a technology used to solve network delay and congestion and other problems. When the network is congested, data may be discarded. In order to meet the requirements of different applications for different QoS, the network needs to allocate and schedule resources according to the requirements of users, and provide different QoS for different data.

[0068] 4. QoS flow (QoS flow)

[0069] The 5G system forwards and processes data based on the granularity of the QoS flow and guarantees the QoS.

[0070] The 5G core network establishes one or more protocol data unit sessions (PDU sessions) for a UE, and the QoS flow is a data flow with the same source and destination address and the same QoS requirement in a PDU session. Figure 2 is a schematic diagram of a 5G system based on a QoS architecture provided by an embodiment of the present application. As shown in Figure 2 , a PDU session is established between the UE and the UPF, a wireless bearer is established between the UE and the NB, a core network tunnel is established between the NB and the UPF, and the PDU session includes a plurality of QoS flows, including a first QoS flow, a second QoS flow, and the like.

[0071] For downlink, the 5GC identifies the characteristics of the data packet, including the source internet protocol (IP) address, the target IP address, the source port number, the target port number, and the transmission layer protocol number, maps the data packets with the same characteristics to the same QoS flow, and carries the QoS flow ID (QFI) in the data packet header to identify which QoS flow the data packet belongs to. For uplink, the 5GC can display or implicitly configure the mapping relationship between the above data packet characteristics and the QoS flow to the UE, and the UE maps the uplink data to be transmitted to different QoS flows.

[0072] Data of different QoS flows are independent of each other when transmitted in the 5G system. For each QoS flow, the 5GC sends its QoS profile to the radio access network (RAN) to indicate its QoS requirements, such as packet delay budget (PDB), packet error rate (PER), etc., which represent the quality of service expected to be obtained by the data of the QoS flow when transmitted in the 5G system. PDB represents the upper limit of the transmission delay of data packets between the core network and the UE, and data packets that fail to be correctly transmitted within the PDB are considered to have timed out. PER represents the upper limit of the packet error rate during the transmission of the QoS flow, i.e., the proportion of data packets that are processed by the sending end but not correctly received by the receiving end. Specifically, between the core network and the UE, for downlink behavior, it can be understood as from the UPF of the core network to the UE; for uplink behavior, it can be understood as from the UE to the UPF of the core network.

[0073] For a PDU session, the RAN establishes one or more data radio bearers (DRBs) for it and maps each QoS flow to the DRBs for air interface transmission. Multiple QoS flows can be mapped to one DRB, but one QoS flow cannot be mapped to multiple DRBs. QoS flows with the same or similar QoS requirements are usually mapped to the same DRB, thereby providing the same QoS guarantee on the air interface.

[0074] 5. QoS parameters of PDU

[0075] The 5GC indicates the QoS requirements of different QoS flows to the RAN through the QoS profile, and these requirements are reflected through various QoS parameters. For example, common QoS parameters include PDB, PER, etc. The transmission network should strive to ensure that the QoS requirements of the service are met to ensure the service experience of the user.

[0076] 6. QoS parameters of PDU set

[0077] The XR service usually expects to require QoS guarantee at the granularity of a PDU set, which is determined by the encoding manner of the XR service. Since a PDU set corresponds to the smallest unit of application layer data processing, for example, a video frame, for many applications, only when all the data packets of the PDU set are correctly received, the receiving side can successfully decode the video frame. Therefore, the XR service needs the transmission network to provide overall QoS guarantee for the PDU set, so as to avoid the decoding failure of the entire video frame caused by the timeout or error of part of the data packets in the PDU set.

[0078] 3GPP R18 (Release-18) designs a new QoS parameter for the XR service, which is called the QoS parameter of the PDU set, including the PDU set delay budget (PSDB), the PDU set error rate (PSER), and the PDU set integrated information (PSIHI). The PSDB and the PSER correspond to the traditional PDB and PER, respectively. The PSDB represents the upper limit of the time delay from the transmission of the first data packet in the PDU set between the core network and the UE to the completion of the transmission of the last data packet in the PDU set between the core network and the UE, that is, the upper limit of the transmission time delay of the PDU set between the core network and the UE. The PDU set that fails to be completely and correctly transmitted within the PSDB is considered to be timed out. The PSER represents the upper limit of the proportion of the number of PDU sets that fail to be correctly transmitted in the transmission process of the QoS flow, that is, the upper limit of the proportion of the PDU sets that are processed by the sending end but not correctly received by the receiving end. The PSIHI is a description of whether the PDU set integrity is required for the QoS flow, which indicates whether all the data packets in the PDU set are required to be correctly received by the receiving side when the application layer processes the PDU set. This is related to the specific implementation of the application.

[0079] In one implementation, an application can only decode a PDU set correctly if all the packets in the PDU set are correctly received. In this case, the transport network should try its best to ensure that all the packets in a PDU set are correctly transmitted within the delay budget when transmitting the PDU set, because once a packet is lost or timed out, the application layer at the receiving end cannot process the PDU set in time, resulting in a degraded user experience. If it is determined that one packet in the PDU set cannot be correctly transmitted in time, the sending side can also give up transmitting the remaining packets, because even if the remaining packets are correctly transmitted, the application cannot process them, and actively giving up can save network resources. In another implementation, an application can decode a PDU set without correctly receiving all the packets in the PDU set, for example, when the PDU set is processed by redundancy coding at the sending side, and the receiving side can recover the data of the PDU set completely as long as it receives a certain number or proportion of the packets. In this case, even if some packets in the PDU set have been lost or timed out, the sending side should still continue to transmit the remaining packets, because they are still useful to the application layer.

[0080] Through the PDU set QoS parameter, the core network requires the RAN to provide PDU set granularity QoS guarantee for the PDU set-based QoS flow (such as XR service), so as to improve the satisfaction of XR users.

[0081] 7. Data discard based on protocol data unit set importance (PSI) (PSI based discard)

[0082] PSI based data discard refers to data discard by a terminal device according to the importance of data. A QoS flow is configured with PDU set integrated handling information (PSIHI), and the entire PDU set can be processed as a whole. If one PDU in the PDU set is lost, the remaining PDU packets in the PDU set can be considered as no longer needed by the XR service, and the remaining PDU data in the PDU set can be discarded to release wireless resources.

[0083] For the uplink, the terminal device can be configured to perform PSI-based data discard for a specific DRB. When the network is congested, the network device can use MAC CE to instruct the terminal to activate PSI-based discard. When the network congestion is relieved, the network device can also instruct the terminal to deactivate PSI-based discard through MAC CE. The terminal device is connected to a network device, and the network device sends configuration information to the terminal device. The configuration information is used to configure the discard timer with shortvalue (a shorter data discard timer) and the discard timer with long value (a longer data discard timer). The terminal device receives the PSI based discard activation command or deactivation command from the network device, and determines to start the corresponding discard timer with short value according to the activation command, or starts the corresponding discard timer with long value according to the deactivation command. After the timer expires, the terminal device discards the corresponding received data in the PDCP entity.

[0084] For downlink, the network device decides whether to indicate PSI-based discard based on parameters such as PSI, PSIHI, and PSDB.

[0085] 8.PDCP packet loss report

[0086] When the transmitting PDCP entity discards some data packets (for example, packets with PDCP sequence numbers (SN) 3 and 4), if the receiving PDCP entity has not yet successfully received these data packets, then when the receiving PDCP entity receives data packets after these packets (for example, a data packet with PDCP SN 5), a sequence number gap (SN gap) will appear in the receiving PDCP receive window. At this time, the receiving PDCP entity will start the reordering timer, hoping to receive data packets 3 and 4 within the timer, and will not submit data packet 5 to the upper layer until the reordering timer expires or data packets 3 and 4 are received. Since the transmitting side has already discarded data packets 3 and 4, the receiving side can only wait for the data packet to time out, which causes additional waiting delay for data packet 5.

[0087] In order to solve the above problem, after the PDCP entity on the sending side discards a data packet, it can actively send a PDCP packet loss report to the receiving side, indicating the SN of the discarded data packet, so that the receiving side knows that these data packets have been discarded. Then, when it is found that these data packets cause an SN gap, the reordering timer is not started for them, and the waiting time for the discarded data packet is not continued, so that the subsequent data can be delivered upward in time.

[0088] Figure 1 is a schematic diagram of a communication system applicable to embodiments of the present application. As shown in Figure 1 , the communication system can include at least one terminal device, and the communication system can also include at least two network devices, such as Figure 1 base station #1 and base station #2. Among them, the terminal device can simultaneously communicate with base station #1 and base station #2. As an example, the terminal device and base station #1, and the terminal device and base station #2 can communicate through wireless links. Each communication device, such as the terminal device, base station #1 or base station #2, can be configured with multiple antennas. For each communication device in the communication system, the configured multiple antennas can include at least one transmitting antenna for transmitting signals and at least one receiving antenna for receiving signals. Therefore, each communication device in the communication system, the terminal device and base station #1, and the terminal device and base station #2 can communicate through multi-antenna technology.

[0089] It should be understood that Figure 1 , the communication system can also include other network devices or can also include other terminal devices, which are only shown as simplified schematic diagrams for ease of understanding, and are not shown in Figure 1 .

[0090] It should also be understood that the terminal device simultaneously communicating with base station #1 and base station #2 can also be referred to as multi-radio dual connectivity (MR-DC) of the terminal device. Among them, one network device communicating with the terminal device can be referred to as a master node (MN), and another network device communicating with the terminal device can be referred to as a secondary node (SN). As an example, it is assumed that base station #1 is MN and base station #2 is SN.

[0091] As an example, according to the difference between MN and SN types, the MR-DC scenario can be further divided into: EN-DC, NR-DC, NE-DC. As an example, when the MR-DC scenario is provided herein, the specific dual connectivity type is not limited, which can be EN-DC, NR-DC, NE-DC and other subsequent evolution of dual connectivity type.

[0092] For example, Figure 3 is a control plane architecture diagram supporting MR-DC. In the MR-DC scenario, the access network device is connected to the core network through the MN, and the MN and the SN exchange related information of the control plane through the Xn interface.

[0093] Next, EN-DC and NR-DC will be described in detail.

[0094] 1、EN-DC

[0095] EN-DC refers to LTE and 5G dual connectivity. The letter E stands for evolved universal terrestrial radio access new radio (E-UTRA), which is the air interface in LTE cellular networks. The letter N stands for new radio (NR), which is a global standard for a unified, more capable 5G wireless air interface. That is, a terminal device supporting EN-DC can be connected to both LTE master node eNB (MN-eNB) and 5G-NR secondary node gNB (SN-gNB) at the same time. EN-DC is a technology that enables the introduction of 5G services and data rates in a 4G-dominant network.

[0096] For example, Figure 4 is a schematic block diagram of a terminal device (e.g., UE) supporting EN-DC. As Figure 4 shown, the bearers in the network can be divided into three categories: master cell group (MCG) bearers, secondary cell group (SCG) bearers, and Split bearers. In EN-DC, MCG bearers use PDCP, RLC, and MAC corresponding to the master node. For EN-DC, 4G (E-UTRA) is the master node, so MCG bearers use E-UTRA PDCP, E-UTRA RLC, and E-UTRA MAC. SCG bearers use PDCP, RLC, and MAC corresponding to the secondary node. For EN-DC, 5G-NR (gNB) is the secondary node, so SCG bearers use NR PDCP, NR RLC, and NR MAC. Split bearers split the air interface data into two bearers. In PDCP, NR PDCP is used. In RLC, MN air interface data is carried using E-UTRA RLC, and SN air interface data is carried using NR RLC. In MAC, MN air interface data is carried using E-UTRA MAC, and SN air interface data is carried using NR MAC.

[0097] It should be understood that the LTE master node eNB (MN-eNB) uses multiple different frequency points to form a multi-layer cell network, and these cells can all serve as control plane anchor points, so these 4G cells are collectively referred to as MCG, and the wireless data bearers established on top of them are referred to as MCG bearers. Correspondingly, multiple 5G cells form an SCG, and the wireless data bearers established on top of them are referred to as SCG bearers. Split bearers refer to splitting the air interface data into two bearers.

[0098] 2、NR-DC

[0099] NR-DC refers to 5G and 5G dual connectivity. A terminal device supporting MR-DC can be connected to a 5G-NR master node gNB (MN-gNB) and a 5G-NR secondary node gNB (SN-gNB) at the same time. Further, the UE can also be connected to a gNB which can act as both master node MN and secondary node SN at the same time and configure MCG and SCG.

[0100] For example, Figure 5 is a schematic block diagram of a terminal device (e.g., UE) supporting MR-DC. As Figure 5 shown, the bearers in the network can be classified into three categories: master cell group (MCG) bearers, secondary cell group (SCG) bearers, and Split bearers. In MR-DC, the MN-gNB is the master node, and the MCG bearers use NR PDCP, MN RLC, and MN MAC; the SN-gNB is the secondary node, and the SCG bearers use NR PDCP, SN RLC, and SN MAC. The Split bearers split the air interface data into two bearers, using NR PDCP in PDCP, using MN RLC for the air interface data of the MN in RLC, using SN RLC for the air interface data of the SN, using MN MAC for the air interface data of the MN in MAC, and using SN MAC for the air interface data of the SN.

[0101] For example, Figure 6 is a schematic diagram of MR-DC architecture supporting multiple bearer types. The multiple bearer types supported under MR-DC can include:

[0102] MCG bearers terminated at the MN (MN terminated MCG bearers);

[0103] SCG bearers terminated at the MN (MN terminated SCG bearers);

[0104] Split bearers terminated at the MN (MN terminated split bearers);

[0105] MCG bearers terminated at the SN (SN terminated MCG bearers);

[0106] SCG bearers terminated at the SN (SN terminated SCG bearers);

[0107] Split bearers terminated at the SN (SN terminated split bearers).

[0108] An MCG bearer involves only MCG-side air interface resources, primarily those at the RLC / MAC / PHY layers. An SCG bearer involves only SCG-side air interface resources, with the data plane radio bearer served solely by the SN. A split bearer involves both MCG-side and SCG-side air interface resources, with the data plane radio bearer served by both the MN and the SN. Termination at the MN / SN means the PDCP entity is located at the MN or SN.

[0109] like Figure 6 As shown in the figure, taking downlink data as an example, assuming that the MN serves as the anchor point and receives data from the core network, for Split bearer, downlink data is split starting from the PDCP layer and sent to the RLC / MAC layers of the MN and SN for processing. For example, the MN can send downlink data to the terminal device through the MN RLC and MN MAC layers in the MN. Alternatively, the MN can send the downlink data to the SN RLC in the SN, which then sends the data to the terminal device through the SN RLC and MN MAC layers in the SN.

[0110] Currently, since XR services require QoS guarantees based on the granularity of PDU sets, the corresponding base stations need to support data processing and forwarding based on PDU sets. Furthermore, during downlink transmission, when the QoS flow requires QoS guarantees based on PDU sets and the base station supports PDU set processing, the core network will add relevant information about the PDU set to the header of each data packet when transmitting the data packet to the base station. The relevant information can be used to identify the PDU set or reflect the attributes of the PDU set. For example, the PDU set sequence number, the sequence number of the PDU within the PDU set, the PDU set size, the PDU set importance, etc., so that the base station can distinguish which PDU set different data packets belong to. If the base station does not support PDU set processing, the core network does not need to add this information. Therefore, the core network needs to know whether the base station supports PDU set processing capabilities. Specifically, if the QoS profile received by the base station contains the QoS parameters of the PDU set, the base station reports to the core network whether it supports processing the PDU set.

[0111] Further, the source base station supports processing PDU set, the core network adds the related information of the PDU set in the data packet sent to the source base station, and in the handover process, the source base station can carry the PDU set QoS parameter information of the QoS flow in the handover request message sent to the target base station. If the target base station supports the processing capability of the PDU set, it carries the indication information to the source base station in the handover response message. Further, the indication information can be a PDU Set based Handling Indicator information element, and the field is set to supported. The source base station judges whether the target base station supports the PDU set processing capability based on the received response message, and further processes the PDU set information based on the judgment. If the target base station supports the PDU set processing capability, the source base station carries the PDU set related information in the data forwarded to the target base station; otherwise, the source base station does not carry the PDU set related information in the data forwarded to the target base station, so as to avoid that the target base station cannot identify the PDU set related information.

[0112] For the MR-DC scenario, the MN has a control plane with the core network, and the control plane information of the SN is forwarded through the MN. The MN and the SN can be independent base station devices and can have different PDU set processing capabilities. When the MN receives the PDU set related information from the core network, if the SN does not support the PDU set processing capability, the PDU set related information provided by the core network cannot be recognized by the SN, resulting in that the XR service cannot be guaranteed in QoS and affecting the user experience.

[0113] In the scenario where the PDCP entity is located in the MN, the QoS Flow data stream received from the core network first reaches the PDCP entity located in the MN, and then the data is processed by the PDCP entity of the MN. Processing the data can include forwarding the data by the MN according to the bearer type, etc. In the scenario where the PDCP entity is located in the SN, the QoS Flow data stream received from the core network first reaches the PDCP entity located in the SN, and then the data is processed by the PDCP entity of the SN. Processing the data can include forwarding the data by the SN according to the bearer type, etc.

[0114] For uplink traffic, after the access network device configures the UE with PSI-based discard, when the network is congested, the access network device can instruct the UE to activate PSI-based discard through MAC CE, instruct the UE to discard data packets with low importance to alleviate the network congestion state, and after the network congestion is alleviated, the access network device can instruct the UE to deactivate PSI-based discard through MAC CE. For a dual connectivity scenario, the master node MN and the secondary node SN each maintain their own congestion state, and both can issue activation / deactivation instructions to the UE through MAC CE. A mechanism is needed to coordinate the activation / deactivation of PSI-based discard between the master node MN and the secondary node SN.

[0115] Figure 7 is a schematic flowchart of a communication method applied in a dual connectivity DC scenario.

[0116] In this embodiment, the first network device and the second network device form a dual connectivity DC for the UE, the first network device can be a master node MN, and the second network device is a secondary node SN; the first network device can also be a secondary node SN, and the second network device is a master node MN. The first network device and the second network device can both include a centralized unit (CU) and a distributed unit (DU) separation architecture, wherein the CU can also include a centralized unit control plane (CU-CP) and a centralized unit user plane (CU-UP). Hereinafter, the network device can be a gNB alone, or a CU, or a DC, or a CU-CP, or a CU-UP, and no distinction is made. Hereinafter, no further description is given.

[0117] The first network device and the second network device can maintain their respective congestion states. Exemplarily, the congestion state can be {congested, not congested}. The initial congestion state of the network device can be "not congested". The first network device and the second network device can also give activation / deactivation of PSI-based discard recommendations based on the congestion state. The activation of PSI-based discard recommendation is equivalent to the congestion state, and the deactivation of PSI-based discard recommendation is equivalent to the not congested state.

[0118] Figure 8 is a schematic flowchart of interaction between two network devices for assisting information between the first network device and the second network device in a DC scenario.

[0119] The first network device and the second network device can also react to the congestion state of the network device through other auxiliary information. The auxiliary information can be that the CU of the first network device informs the DU of the first network device, or the DU of the second network device informs the CU of the second network device, and then the CU of the second network device forwards the auxiliary information to the CU of the first network device. The CU can be a CU-CP or a CU-UP. The above auxiliary information can include one or more of the following:

[0120] Activation / deactivation of the UE-based PSI discard suggestion;

[0121] Activation / deactivation of the downlink-based PSI discard suggestion;

[0122] The congestion state of the network device;

[0123] The congestion level of the network device;

[0124] The air interface rate that the network device can support, etc.

[0125] The second network device can actively update the above auxiliary information to the first network device when the auxiliary information changes, or update the above auxiliary information based on the update request of the first network device. The above auxiliary information can be transmitted through the Xn interface, or can be carried in the packet header forwarded by the network device to another network device.

[0126] In the CU and DU separation scenario, the DU of the first network device or the second network device can actively update the above auxiliary information to the CU of the first network device or the second network device through the F1 interface message, or update the above auxiliary information based on the request of the CU.

[0127] After receiving the auxiliary information, the first network device can execute one or more of the following methods to relieve network congestion based on the comprehensive congestion situation of the first network device and the second network device:

[0128] Indicating the UE to activate / deactivate the downlink-based PSI discard;

[0129] Activation / deactivation of the downlink-based PSI discard;

[0130] Adjusting the split ratio of the split bearer, for example, reducing the amount of split data of the network device on the congestion side;

[0131] Feedback of congestion information to the core network;

[0132] Adding an explicit congestion identifier (ECN) in the packet.

[0133] In the method, optionally, the CU and DU separation scenario can instruct the UE to activate / deactivate the downlink PSI-based discard by the DU of the first network device; the activation / deactivation of the downlink PSI-based discard, or the adjustment of the split ratio of the separated bearer, or the feedback of the congestion information to the core network, or the addition of the explicit congestion notification (ECN) in the data packet can be performed by the CU or CU-CP of the first network device.

[0134] In the DC scenario, the network device that decides to configure the PSI-based discard for the UE is determined by the first network device or the second network device, and the first network device can be a network device where the PDCP entity is located or a network device without the PDCP entity.

[0135] For example, for the scenario where the bearer is terminated at the MN, the PDCP entity is located at the MN side, and whether to configure the PSI-based discard for the UE is decided by the master node MN or the secondary node SN; for the scenario where the bearer is terminated at the SN, the PDCP entity is located at the SN side, and whether to configure the PSI-based discard for the UE is decided by the secondary node SN or the master node MN.

[0136] For example, in the DC scenario, for the downlink PSI-based discard, when the network is congested, the network device can decide whether to perform the PSI-based discard by itself. For the scenario where the bearer is terminated at the MN, the PDCP entity is located at the MN side, and whether to perform the PSI-based discard on the downlink PDU set is decided by the master node MN or the secondary node SN; for the scenario where the bearer is terminated at the SN, the PDCP entity is located at the SN side, and whether to perform the PSI-based discard on the downlink PDU set is decided by the secondary node SN or the master node MN. The steps of the method described in the embodiment are described in detail below. In the embodiment of the present application, the first network device can be the master node MN or the secondary node SN:

[0137] S710, the first network device configures the PSI-based discard for the UE, and the configuration information can be sent to the UE through a radio resource control (RRC) message.

[0138] S720, optionally, the first network device notifies the second network device that the PSI-based discard has been configured for the UE through an Xn interface message.

[0139] Optionally, if the network device is a CU and DU separation architecture, the CU of the first network device notifies the CU of the second network device that the PSI-based discard has been configured for the UE through an Xn interface message.

[0140] Optionally, when the first network device is the MN, the Xn interface message can be an S-NODE ADDITION / MODIFICATION REQUEST message; when the first network device is the SN, the Xn interface message can be an S-NODE ADDITION / MODIFICATION REQUEST ACKNOWLEDGE or S-NODE MODIFICATION REQUIRED message.

[0141] The first network device and the second network device maintain respective congestion states, and the initial state of each is not congested.

[0142] Optionally, if the network device is a CU and DU separation architecture, the DU can send the congestion state or the suggestion of activating / deactivating PSI-based discard to the CU, and the information can be transmitted through an F1 interface message or through a packet header of uplink data submitted by the DU to the CU.

[0143] S730, optionally, when the congestion state of the second network device changes, for example, from not congested to congested, the second network device updates the assistance information to the first network device, which can help the first network device to learn the latest congestion state of the second network device.

[0144] The first network device can learn the congestion state condition of the first network device and the second network device constituting the DC, and the congestion state condition can be:

[0145] The first condition: the first network device is congested, and the second network device is congested;

[0146] The second condition: the first network device is congested, or the second network device is congested;

[0147] The third condition: the first network device is not congested, or the second network device is not congested;

[0148] The fourth condition: the first network device is not congested, and the second network device is not congested;

[0149] The congestion state condition in the above conditions can be comprehensively derived based on the above assistance information.

[0150] S740, the first network device determines to activate the UE to perform PSI-based discard according to the congestion state condition of the first network device and the second network device, i.e., according to the first condition or the second condition, and sends the indication information of activating PSI-based discard to the UE, and the activation indication information can be sent through a MAC CE. Optionally, the first network device can notify the second network device of the activation information through an Xn interface message.

[0151] S750, optionally, when the congestion state of the second network device changes, for example, from the congested state to the uncongested state, the second network device updates the assistance information to the first network device, which can assist the first network device to learn the latest congestion state of the second network device.

[0152] S760, the first network device determines to deactivate the UE to perform the PSI-based discard according to the congestion state condition of the first network device and the second network device, i.e., according to the third condition or the fourth condition, and sends the UE the deactivation indication information of the PSI-based discard, which is sent through the MAC CE.

[0153] S770, optionally, the first network device notifies the second network device of the deactivation information through the Xn interface message.

[0154] S780, optionally, when the congestion state of the first network device changes, for example, from the uncongested state to the congested state, the first network device updates the assistance information to the second network device, which can assist the second network device to learn the latest congestion state of the first network device.

[0155] The second network device can learn the congestion state condition of the first network device and the second network device constituting the DC.

[0156] S790, the second network device determines to activate the UE to perform the PSI-based discard according to the congestion state condition of the first network device and the second network device, i.e., according to the first condition or the second condition, and sends the UE the activation indication information of the PSI-based discard, which can be sent through the MAC CE. Optionally, the second network device can notify the first network device of the activation information through the Xn interface message.

[0157] S7100, optionally, when the congestion state of the first network device changes, for example, from the congested state to the uncongested state, the first network device updates the assistance information to the second network device, which can assist the second network device to learn the latest congestion state of the first network device.

[0158] S7110, the second network device determines to deactivate the UE to perform the PSI-based discard according to the congestion state condition of the first network device and the second network device, i.e., according to the third condition or the fourth condition, and sends the UE the deactivation indication information of the PSI-based discard, which is sent through the MAC CE.

[0159] S7120, optionally, the second network device notifies the first network device of the deactivation information through the Xn interface message.

[0160] Exemplarily, the first network device sends, to the UE, indication information of activating PSI-based discard according to a first condition, and the activation indication information can be sent through a MAC CE. Optionally, the first network device can notify the second network device of the activation information through an Xn interface message. After the congestion state is updated, the first network device sends, to the UE, indication information of deactivating PSI-based discard according to a third condition, and the deactivation indication information is sent through a MAC CE. Optionally, the first network device notifies the second network device of the deactivation information through an Xn interface message.

[0161] Exemplarily, the first network device sends, to the UE, indication information of activating PSI-based discard according to a first condition, and the activation indication information can be sent through a MAC CE. Optionally, the first network device can notify the second network device of the activation information through an Xn interface message. After the congestion state is updated, the first network device sends, to the UE, indication information of deactivating PSI-based discard according to a fourth condition, and the deactivation indication information is sent through a MAC CE. Optionally, the first network device notifies the second network device of the deactivation information through an Xn interface message.

[0162] Exemplarily, the first network device sends, to the UE, indication information of activating PSI-based discard according to a second condition, and the activation indication information can be sent through a MAC CE. Optionally, the first network device can notify the second network device of the activation information through an Xn interface message. After the congestion state is updated, the first network device sends, to the UE, indication information of deactivating PSI-based discard according to a third condition, and the deactivation indication information is sent through a MAC CE. Optionally, the first network device notifies the second network device of the deactivation information through an Xn interface message.

[0163] Exemplarily, the first network device sends, to the UE, indication information of activating PSI-based discard according to a second condition, and the activation indication information can be sent through a MAC CE. Optionally, the first network device can notify the second network device of the activation information through an Xn interface message. After the congestion state is updated, the first network device sends, to the UE, indication information of deactivating PSI-based discard according to a fourth condition, and the deactivation indication information is sent through a MAC CE. Optionally, the first network device notifies the second network device of the deactivation information through an Xn interface message.

[0164] Generally, XR service generates data frames periodically at a certain frame rate. One data frame can be transmitted by multiple data packets, which can be divided into one or more PDU sets. After the transmission of a data frame or a PDU set in a data period, the core network can indicate to the base station the end of a data burst or the end of a PDU set by adding indication information in the last data packet PDU of the data burst or the PDU set, which indicates the end of data transmission of the PDU set in the current period, so that the base station can instruct the UE to enter sleep after the end of the data burst, until the next data burst period arrives, thereby achieving the effect of UE energy saving. In a dual connectivity scenario, for a split bearer, only the network device where the PDCP entity is located can receive the indication information from the core network. The following provides a method for two network devices to interact with the data burst end information in a DC scenario.

[0165] S810, the first network device receives data packet carrying data burst end indication information (End of data burst) from the core network, the data burst indication information indicating the end of data transmission of the PDU set in the current period.

[0166] S820, the first network device sends the above-mentioned data burst end indication information (End of data burst) to the second network device. The above-mentioned indication information can be forwarded by directly forwarding the data packet carrying the data burst end indication information received from the core network, or the data burst end indication information (End of data burst) can be added in the data packet forwarded to the second network device, or an empty data packet can be sent to carry the data burst end indication information.

[0167] Optionally, in a CU and DU separation scenario, the CU or CU-UP of the first network device sends the data burst end indication information (End of data burst) to the CU or CU-UP of the second network device.

[0168] Optionally, in a CU and DU separation scenario, the CU of the first network device can also indicate the data burst end indication information (End of data burst) to the DU of the first network device. For example, the indication information can be carried in the last data packet of the data burst sent by the CU to the DU, or an empty data packet can be sent to carry the data burst indication information. Similarly, after the CU of the second network device receives the data burst end indication information (End of data burst), it can also indicate the DU of the second network device according to the above-mentioned method.

[0169] When the network device location where the PDCP entity is located changes, for example, the UE switches from a source base station to a target base station, for downlink, the UE sends a status report to the target base station, requesting the target base station to retransmit the data packets that the UE has not received, if some of the data packets are discarded by the source station before the switching, the target station cannot obtain the data packets and cannot retransmit them. For uplink, the target station sends a status report to the UE, requesting the UE to retransmit the data packets that the base station has not received, if some of the data packets are discarded by the UE before the switching, the UE cannot retransmit the data packets. The following provides a method for avoiding continuing to wait for retransmission of the discarded data packets before the switching after the switching.

[0170] Figure 9 FIG. 1 is a schematic flowchart of downlink packet loss data indication in a switching scenario provided by an embodiment of the present application.

[0171] For a downlink data transmission scenario:

[0172] S910, the third network device sends a PDCP packet loss report to the UE, indicating that the first PDU or the first PDU set is discarded.

[0173] S920, the third network device sends a switching command, indicating that the UE switches from the third network device to a fourth network device. After receiving the switching command, the UE switches to the fourth network device.

[0174] S930, the UE sends first status information to the fourth network device, indicating that the first PDU or the first PDU set has been received or confirmed.

[0175] Figure 10 FIG. 2 is a schematic flowchart of uplink packet loss data indication in a switching scenario provided by an embodiment of the present application.

[0176] For an uplink data transmission scenario:

[0177] S1010, the UE sends a PDCP packet loss report to the third network device, indicating that the second PDU or the second PDU set is discarded.

[0178] S1020, the third network device sends a switching command, indicating that the UE switches from the third network device to a fourth network device. After receiving the switching command, the UE switches to the fourth network device.

[0179] S1030, the third network device sends second status information to the fourth network device, indicating that the second PDU or the second PDU set has been received or confirmed.

[0180] S1040, the third network device forwards the uplink data of the UE to the fourth network device.

[0181] S1050: The fourth network device confirms that the uplink data forwarded by the third network device does not include the second PDU or the second PDU set. The fourth network device considers that the second PDU or the second PDU set has been received or discarded, and does not start a reordering timer for the second PDU or the second PDU set.

[0182] Optionally, S1060, the fourth network device sends a third status report to the UE, indicating that the second PDU or the second PDU set has been received or confirmed.

[0183] When a UE or a network device receives a PDCP packet loss report, for a data packet indicated as discarded, if the UE or the network device has already received the data packet, the UE or the network device ignores the indication in the packet loss report.

[0184] When a UE or a network device receives a data packet, and the data packet has been indicated as discarded by a PDCP packet loss report, the UE or the network device saves the data packet, processes it, and then submits it to an upper layer.

[0185] It should be understood that the size of the serial numbers of the above processes does not mean the 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 the present application.

[0186] It should also be understood that in the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other, and the technical features in different embodiments can be combined to form new embodiments according to their internal logical relationships.

[0187] It should also be understood that in some of the above embodiments, devices in existing network architectures are mainly used as examples for illustrative purposes, and it should be understood that the embodiments of the present application do not limit the specific form of the devices. For example, devices that can achieve the same functions in the future are applicable to the embodiments of the present application.

[0188] It is understandable that in the above-mentioned various method embodiments, the methods and operations implemented by the devices (the primary node MN and the secondary node SN) may also be implemented by components (such as chips or circuits) that can be used in the devices.

[0189] It can also be understood that some optional features in the various embodiments of the present application may not depend on other features in certain scenarios, and may also be combined with other features in certain scenarios, without limitation.

[0190] Those skilled in the art can understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in the form of hardware or a combination of hardware and computer software. Whether a certain function is realized in the form of hardware or computer software driving hardware 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 the present application.

[0191] The following describes the communication device provided by the embodiments of the present application in combination with Figures 11 to 13 The communication device is described in detail. It should be understood that the description of the device embodiments corresponds to the description of the method embodiments, and therefore, the content not described in detail can be referred to the method embodiments described above, and some content will not be described again for the sake of brevity.

[0192] The embodiments of the present application can divide the function modules of the sending device or the receiving device according to the method examples described above, for example, each function module can be divided according to each function, or two or more functions can be integrated in one processing module. The integrated module can be realized in the form of hardware or software function module. It should be noted that the division of the modules in the embodiments of the present application is illustrative, and is only a logical function division, and another division mode can be used in actual implementation. The following will be described taking the example of dividing each function module according to each function.

[0193] Figure 11 FIG. 1 is a schematic block diagram of the communication device 10 provided by the embodiments of the present application. The device 10 includes a transceiver module 11 and a processing module 12. The transceiver module 11 can realize corresponding communication functions, and the processing module 12 is used for data processing, or the transceiver module 11 is used for executing operations related to receiving and sending, and the processing module 12 is used for executing other operations except receiving and sending. The transceiver module 11 can also be referred to as a communication interface or a communication unit.

[0194] Optionally, the device 10 can further include a storage module 13, which can be used to store instructions and / or data, and the processing module 12 can read the instructions and / or data in the storage module to enable the device to implement the actions of the equipment in each of the foregoing method embodiments.

[0195] In one design, the device 10 can correspond to the first network device or the second network device in the method embodiments described above, or be a component (such as a chip) of the first network device or the second network device.

[0196] The device 10 can realize the functions corresponding to the method embodiments described above. Figure 7the steps or procedures performed by the first network device or the second network device apparatus in the above method embodiments, wherein the transceiving module 11 can be configured to perform the above Figure 7 the transceiving related operations of the first network device or the second network device apparatus in the above method embodiments, the processing module 12 can be configured to perform the above Figure 7 the processing related operations of the first network device in the above method embodiments.

[0197] It should also be understood that the apparatus 10 herein is embodied in the form of functional modules. The term "module" herein can refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and / or other suitable components that provide the described functionality. In one optional example, those skilled in the art can understand that the apparatus 10 can be embodied as the first communication apparatus in the above embodiments, and can be configured to perform the procedures and / or steps corresponding to the first communication apparatus in the above method embodiments; or the apparatus 10 can be embodied as the second communication apparatus in the above embodiments, and can be configured to perform the procedures and / or steps corresponding to the second communication apparatus in the above method embodiments. To avoid repetition, details are not described herein.

[0198] The apparatus 10 of each of the above schemes has the function of implementing the corresponding steps performed by the device (e.g. the first communication apparatus) in the above method embodiments. The function can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions; for example, the transceiving module can be replaced by a transceiver (e.g. the sending unit in the transceiving module can be replaced by a transmitter, and the receiving unit in the transceiving module can be replaced by a receiver), and other units such as the processing module can be replaced by a processor, which respectively perform the transceiving operations and related processing operations in each of the method embodiments.

[0199] In addition, the above transceiving module 11 can also be a transceiving circuit (e.g. can include a receiving circuit and a sending circuit), and the processing module can be a processing circuit.

[0200] Figure 12 is a schematic diagram of another communication apparatus 20 provided by the embodiments of the present application. The apparatus 20 includes a processor 21, which is configured to execute computer programs or instructions stored in a memory 22, or read data / signaling stored in the memory 22, to perform the methods in the above method embodiments. Optionally, the processor 21 is one or more.

[0201] Optionally, as Figure 12As shown, the apparatus 20 further includes a memory 22 for storing computer programs or instructions and / or data. The memory 22 can be integrated with the processor 21, or can also be separately arranged. Optionally, the memory 22 is one or more.

[0202] Optionally, as shown, the apparatus 20 further includes a transceiver 23 for receiving and / or sending signals. For example, the processor 21 is configured to control the transceiver 23 to receive and / or send signals. Figure 12

[0203] As an option, the apparatus 20 is configured to implement operations performed by an access network device or a master node MN or a secondary node SN in the various method embodiments above.

[0204] It should be understood that the processor mentioned in the embodiments of the present application can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0205] ​It should also be understood that the memory mentioned in the embodiments of the present application may be a volatile memory and / or a non-volatile memory. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM). For example, RAM can be used as an external cache. By way of example and not limitation, RAM includes the following forms: static random access memory (SRAM), dynamic random access memory (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 link dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0206] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, the memory (storage module) can be integrated into the processor.

[0207] It should also be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0208] Figure 13 FIG2 is a schematic diagram of a chip system 30 provided in an embodiment of the present application. The chip system 30 (or also referred to as a processing system) includes a logic circuit 31 and an input / output interface 32 .

[0209] The logic circuit 31 may be a processing circuit in the chip system 30. The logic circuit 31 may be coupled to a storage unit and call instructions in the storage unit so that the chip system 30 can implement the methods and functions of the various embodiments of the present application. The input / output interface 32 may be an input / output circuit in the chip system 30, outputting information processed by the chip system 30 or inputting data or signaling information to be processed into the chip system 30 for processing.

[0210] As a solution, the chip system 30 is configured to implement operations performed by the access network device or the master node MN or the secondary node SN in the above various method embodiments.

[0211] For example, the logic circuit 31 is configured to implement processing-related operations performed by the access network device or the master node MN or the secondary node SN in the above method embodiments; and the input / output interface 32 is configured to implement sending and / or receiving-related operations performed by the terminal device in the above method embodiments.

[0212] Embodiments of the present application also provide a computer readable storage medium having stored thereon computer instructions for implementing the method performed by the device in the above various method embodiments.

[0213] For example, the computer program, when executed by a computer, enables the computer to implement the method performed by the access network device or the master node MN or the secondary node SN in the above various method embodiments.

[0214] Embodiments of the present application also provide a computer program product comprising instructions, which, when executed by a computer, implement the method performed by the access network device or the master node MN or the secondary node SN in the above various method embodiments.

[0215] Embodiments of the present application also provide a communication system comprising the aforementioned master node MN and secondary node SN.

[0216] The above-described any device-related content can be explained and beneficial effects can be referred to the corresponding method embodiments provided above, and will not be described here again.

[0217] Those skilled in the art can understand that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized 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 the present application.

[0218] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the foregoing method embodiments, and will not be described here again.

[0219] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other manners. For example, the described device embodiments are merely schematic. The division of the units is merely logical function division. There can be other division manners in actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections can be indirect couplings or communication connections through some interfaces, devices or units, and can be in electrical, mechanical or other forms.

[0220] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., can be located in one place, or can be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0221] In addition, each functional unit in the various embodiments of the present application can be integrated into a processing unit, or each unit can be a physically independent unit, or two or more units can be integrated into a unit.

[0222] If the functions are realized in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application can be embodied in the form of a software product, and the computer software product is stored in a storage medium, and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various program code storage media.

[0223] The above is merely specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for communication in a dual connectivity (DC) scenario, the method comprising: Applied to a first network device, Receiving auxiliary information sent by a second network device, the auxiliary information being used for feeding back a radio resource congestion state of the second network device, and the auxiliary information including one or more of the following: Activation / deactivation of a suggestion of discarding based on protocol data unit set importance (PSI); A congestion state of the network device; A congestion level of the network device; An air interface rate that can be supported by the network device, and the like; Based on the above auxiliary information, one or more of the following operations are performed: Indicating a UE to activate / deactivate discarding based on protocol data unit set importance (PSI); Activating / deactivating downlink discarding based on protocol data unit set importance (PSI); Adjusting a split ratio of a split bearer; Feeding back congestion information to a core network; Adding an explicit congestion notification (ECN) in a data packet.

2. The method of claim 1, wherein, The method further includes: The first network device determines a congestion state condition of the first network device and the second network device, and the congestion state condition is one of the following: A first condition: the first network device is congested, and the second network device is congested; A second condition: the first network device is congested, or the second network device is congested; A third condition: the first network device is not congested, or the second network device is not congested; A fourth condition: the first network device is not congested, and the second network device is not congested; According to the first condition or the second condition, the UE is instructed to activate discarding based on protocol data unit set importance (PSI); According to the third condition or the fourth condition, the UE is instructed to deactivate discarding based on protocol data unit set importance (PSI).

3. The method of claim 1, wherein The auxiliary information is carried in an Xn interface message or in a protocol data unit (PDU) header.

4. The method of claim 1 or 2, wherein The CU of the first network device receives auxiliary information sent by the DU of the first network device, and the auxiliary information can be carried in an F1 interface message.

5. The method of any one of claims 1 to 4, wherein The first network device is a master node (MN) in a DC scenario, and the second network device is a secondary node (SN) in the DC scenario; or the first network device is a secondary node (SN) in a DC scenario, and the second network device is a master node (MN) in the DC scenario. 6.A method for communication in a dual connectivity (DC) scenario, comprising: Applied to a second network device, The first network device sends assistance information to the second network device, wherein the assistance information is used to feed back the radio resource congestion status of the second network device, and the assistance information can include one or more of the following: Activation / deactivation of PSI discard-based suggestions; Congestion status of the network device; Congestion level of the network device; Air interface rate that can be supported by the network device, etc.

7. The method of claim 6, wherein: The CU of the second network device receives the assistance information sent by the DU of the second network device, and the assistance information can be carried in an F1 interface message.

8. The method of any one of claims 6 or 7, wherein: The first network device is a master node (MN) in a dual connectivity (DC) scenario, and the second network device is a secondary node (SN) in the DC scenario; or the first network device is a secondary node (SN) in a dual connectivity (DC) scenario, and the second network device is a master node (MN) in the DC scenario.

9. A data transmission method applied to dual connectivity (DC), wherein: The first network device receives a PDU data packet from a core network, wherein the PDU carries end of data burst indication information (End of data burst), and the end of data burst indication information is used to indicate the end of data transmission of the data burst; The first network device sends the end of data burst indication information (End of data burst) to the second network device.

10. The method of claim 9, wherein: The first network device sends the end of data burst indication information (End of data burst) to the second network device by one or more of the following methods: The first network device forwards the PDU data packet received from the core network, wherein the PDU data packet carries the end of data burst indication information (End of data burst); The first network device adds the end of data burst indication information (End of data burst) to the PDU data packet forwarded to the second network device; The first network device sends an empty PDU data packet carrying the end of data burst indication information (End of data burst) to the second network device.

11. The method of claim 9 or 10, wherein: The CU of the first network device sends the end of data burst indication information (End of data burst) to the DU of the first network device.

12. A communication device, comprising: A processor coupled with a memory, wherein the memory is used to store computer programs or instructions, and the processor is used to execute the computer programs or instructions in the memory, so that the device performs the method of any one of claims 1 to 11.

13. A computer readable storage medium, comprising: The computer readable storage medium stores computer programs or instructions which, when run on a computer, cause the computer to perform the method of any one of claims 1 to 11.

14. A chip system, characterized by comprising: a processor for calling and running computer programs from the memory, so that the communication device installed with the chip system performs the method of any one of claims 1 to 11.

15. A computer program product, characterized by: when the computer program product is run on a computer, causing the computer to perform the method of any one of claims 1 to 11.

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