CN115885557A

CN115885557A - Data transmission method, terminal equipment and network node

Info

Publication number: CN115885557A
Application number: CN202080103120.8A
Authority: CN
Inventors: 王淑坤
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2020-08-17
Filing date: 2020-08-17
Publication date: 2023-03-31
Also published as: WO2022036507A1

Abstract

A data transmission method, a terminal device and a network node are provided, the method comprises: the terminal equipment receives first configuration information, wherein the first configuration information is used for configuring small data transmission configuration corresponding to a Data Radio Bearer (DRB); and the terminal equipment transmits the small data according to the first configuration information.

Description

Data transmission method, terminal equipment and network node

Technical Field

The embodiments of the present application relate to the field of communications, and in particular, to a data transmission method, a terminal device, and a network node.

Background

Small data transmission of a terminal in an inactive state may be supported in a New Radio (NR) communication system.

The NR system also supports a Multi-RAT Dual Connectivity (MR-DC) scenario, where data transmission on different bearers differs with respect to the use of radio resources and the use of keys.

For the purpose of power saving of the terminal, a concept of Secondary Cell Group (SCG) deactivation is introduced, i.e., transmission on the SCG side may be suspended even if the terminal is in a connected state. Thus, how to perform small data transmission without activating the SCG side radio resource in the MR-DC scenario is an urgent problem to be solved.

Disclosure of Invention

The data transmission method, the terminal equipment and the network node are provided, and small data transmission can be carried out under the condition that radio resources on an SCG side are not activated.

In a first aspect, a data transmission method is provided, including: the method comprises the steps that terminal equipment receives first configuration information, wherein the first configuration information is used for configuring small data transmission configuration corresponding to a Data Radio Bearer (DRB); and the terminal equipment transmits the small data according to the first configuration information.

In a second aspect, a data transmission method is provided, including: the first node sends first configuration information to the terminal equipment, wherein the first configuration information is used for configuring small data transmission configuration corresponding to the Data Radio Bearer (DRB).

In a third aspect, a terminal device is provided, configured to perform the method in the first aspect or any possible implementation manner of the first aspect. In particular, the terminal device comprises means for performing the method of the first aspect described above or any possible implementation manner of the first aspect.

In a fourth aspect, there is provided a network device for performing the method of the second aspect or any possible implementation manner of the second aspect. In particular, the network device comprises means for performing the method of the second aspect described above or any possible implementation of the second aspect.

In a fifth aspect, a terminal device is provided, where the terminal device includes: including a processor and a memory. The memory is used for storing a computer program, and the processor is used for calling and running the computer program stored in the memory to execute the method in the first aspect or each implementation manner thereof.

In a sixth aspect, a network device is provided, which includes: including a processor and memory. The memory is used for storing a computer program, and the processor is used for calling and running the computer program stored in the memory to execute the method of the second aspect or each implementation mode thereof.

In a seventh aspect, a chip is provided for implementing the method in any one of the first to second aspects or its implementation manners.

Specifically, the chip includes: a processor configured to call and run the computer program from the memory, so that the device on which the chip is installed performs the method in any one of the first aspect to the second aspect or the implementation manner thereof.

In an eighth aspect, a computer-readable storage medium is provided for storing a computer program, the computer program causing a computer to perform the method of any one of the first to second aspects or implementations thereof.

In a ninth aspect, there is provided a computer program product comprising computer program instructions to cause a computer to perform the method of any one of the first to second aspects or implementations thereof.

A tenth aspect provides a computer program which, when run on a computer, causes the computer to perform the method of any one of the first to second aspects or implementations thereof.

Based on the above technical solution, the network device may perform small data transmission configuration on the DRB, for example, configure the SCG bearer not to be used for small data transmission or configure the SCG bearer capable of being used for small data transmission, and configure a manner of performing small data transmission on the SCG bearer, when the small data reaches the DRB, the terminal device may perform small data transmission according to the small data transmission configuration corresponding to the DRB, so as to perform small data transmission without activating radio resources on the SCG side.

Drawings

Fig. 1 and 2 are schematic block diagrams of a system framework provided by the present application.

Fig. 3 and 4 are examples of specific scenarios of EN-DC shown in fig. 2, respectively.

Fig. 5 is a schematic configuration diagram of a bearer under the EN-DC system shown in fig. 2.

Fig. 6 is a schematic structural diagram of a DC bearer under a 5GC system according to an embodiment of the present application.

Fig. 7 is a schematic diagram of state transition of a terminal device provided in the present application.

FIG. 8 is a schematic representation of an RNA of a terminal device in an inactive state as provided herein.

Fig. 9 is a schematic flow diagram of an RNAU with context migration provided herein.

Fig. 10 is a schematic flow diagram of an RNAU without context migration as provided herein.

Fig. 11 is a schematic flow chart of a small data transmission provided in the present application.

Fig. 12 is a schematic diagram of a data transmission method provided in an embodiment of the present application.

Fig. 13 is a schematic diagram of a data transmission method according to another embodiment of the present application.

Fig. 14 is a schematic diagram of a data transmission method according to another embodiment of the present application.

Fig. 15 is a detailed flowchart of the data transmission method shown in fig. 14.

Fig. 16 to 22 are schematic diagrams of packet header formats of MAC SDUs.

Fig. 23 is a schematic interaction diagram of a data transmission method according to yet another embodiment of the present application.

Fig. 24 is a detailed flowchart of the data transmission method shown in fig. 23.

Fig. 25 is a schematic block diagram of a network node provided in an embodiment of the present application.

Fig. 26 is a schematic block diagram of a terminal device provided in an embodiment of the present application.

Fig. 27 is a schematic block diagram of a communication device provided in an embodiment of the present application.

Fig. 28 is a schematic block diagram of a chip provided in an embodiment of the present application.

Fig. 29 is a schematic block diagram of a communication system provided in an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art without making any creative effort with respect to the embodiments in the present application belong to the protection scope of the present application.

Fig. 1 is a schematic diagram of a system 100 of an embodiment of the present application. As shown in fig. 1, a terminal device 110 is connected to a first network device 130 in a first communication system and a second network device 120 in a second communication system, for example, the first network device 130 is a network device in Long Term Evolution (LTE), and the second network device 120 is a network device in New Radio (NR).

The first network device 130 and the second network device 120 may include a plurality of cells.

It should be understood that fig. 1 is an example of a communication system of the embodiment of the present application, and the embodiment of the present application is not limited to that shown in fig. 1.

As an example, a communication system adapted by the embodiment of the present application may include at least a plurality of network devices under the first communication system and/or a plurality of network devices under the second communication system.

For example, the system 100 shown in fig. 1 may include one primary network device under a first communication system and at least one secondary network device under a second communication system. At least one auxiliary network device is connected to the one main network device, respectively, to form a multi-connection, and is connected to the terminal device 110, respectively, to provide a service thereto. In particular, terminal device 110 may establish a connection through both the primary network device and the secondary network device.

Optionally, the connection established between the terminal device 110 and the primary network device is a primary connection, and the connection established between the terminal device 110 and the auxiliary network device is an auxiliary connection. The control signaling of the terminal device 110 may be transmitted through the main connection, and the data of the terminal device 110 may be transmitted through the main connection and the auxiliary connection simultaneously, or may be transmitted through only the auxiliary connection.

As still another example, the first communication system and the second communication system in the embodiment of the present application are different, but the specific category of the first communication system and the second communication system is not limited.

For example, the first communication system and the second communication system may be various communication systems, such as: a Global System for Mobile communications (GSM) System, a Code Division Multiple Access (CDMA) System, a Wideband Code Division Multiple Access (WCDMA) System, a General Packet Radio Service (GPRS), a Long Term Evolution (Long Term Evolution, LTE) System, a Time Division Duplex (TDD), a Universal Mobile Telecommunications System (UMTS), and the like.

In the system 100 shown in fig. 1, the first network device 130 is taken as a main network device, and the second network device 120 is taken as an auxiliary network device.

The first network device 130 may be an LTE network device and the second network device 120 may be an NR network device. Or the first network device 130 may be an NR network device and the second network device 120 may be an LTE network device. Or both the first network device 130 and the second network device 120 may be NR network devices. Or the first network device 130 may be a GSM network device, a CDMA network device, etc., and the second network device 120 may also be a GSM network device, a CDMA network device, etc. Alternatively, the first network device 130 may be a macro base station (macro cell), and the second network device 120 may be a micro cell base station (micro cell), a pico cell base station (pico cell), a femto cell base station (Femtocell), or the like.

Alternatively, the first network device 130 and the second network device 120 may be any access network devices.

Alternatively, the Access network device may be a Base Transceiver Station (BTS) in a Global System for Mobile communications (GSM) System or a Code Division Multiple Access (CDMA), a Base Station (NodeB, NB) in a Wideband Code Division Multiple Access (WCDMA) System, or an evolved Base Station (evolved Node B, eNB, or eNodeB) in a Long Term Evolution (Long Term Evolution, LTE) System.

Optionally, the Access Network device may also be a Next Generation Radio Access Network (NG RAN), or a base station (gNB) in an NR system, or a wireless controller in a Cloud Radio Access Network (CRAN), or the Access Network device may be a relay station, an Access point, an in-vehicle device, a wearable device, or a Network device in a Public Land Mobile Network (PLMN) for future evolution, or the like.

Taking the first network device 130 as an LTE network device and the second network device 120 as an NR network device as an example, the technical solution of the embodiment of the present application may be applied to a Long Term Evolution (LTE) coverage mode and an NR isolated island coverage mode. Optionally, a tight connection (light interworking) between LTE and NR. The main application scenarios of 5G include: enhanced Mobile Ultra wide band (eMBB), low-Latency high-reliability Communication (URLLC), and massive machine type Communication (mMTC). Among them, the eMBB aims at users to obtain multimedia contents, services and data, and its demand is rapidly increasing. As the eMBB may be deployed in different scenarios. For example, indoor, urban, rural and the like, the difference between the capabilities and the needs is relatively large, so that the detailed analysis can be combined with the specific deployment scenario without any generalization. Typical applications of URLLC include: industrial automation, electric power automation, remote medical operation (surgery), traffic safety, and the like. Typical characteristics of mtc include: high connection density, small data volume, insensitive time delay service, low cost and long service life of the module, etc.

Alternatively, terminal device 110 may be any terminal device. A terminal device may communicate with one or more Core networks (Core networks) via a Radio Access Network (RAN), which may also be referred to as an Access terminal, a User Equipment (UE), a subscriber unit, a subscriber station, a mobile station, a remote terminal, a mobile device, a User terminal, a wireless communication device, a User agent, or a User Equipment. For example, it may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device having a Wireless communication function, a computing device or other processing device connected to a Wireless modem, an in-vehicle device, a wearable device, a terminal device in a 5G network, and the like.

It should be understood that the terms "system" and "network" are often used interchangeably herein. The term "and/or" herein is merely an association relationship describing an associated object, and means that there may be three relationships, for example, a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter associated objects are in an "or" relationship.

Fig. 2 is a schematic block diagram of an EN-DC network architecture 200 of an embodiment of the present invention.

As shown in fig. 2, the network architecture 200 may be LTE-NR Dual Connectivity (EN-DC). That is, LTE serves as a Master Node (MN) and NR serves as a Slave Node (SN), and in other alternative embodiments, MN is also called MeNB and SN is also called SeNB.

In the embodiment of the present application, an NR network architecture is added to an LTE architecture to form a network architecture 200, and as shown in fig. 2, the network architecture 200 may include an MME/S-GW 211, an MME/S-GW 212, a 5G base station (gNB) 221, a gNB 222, an Evolved Node B (eNB) 231, and an eNB 232. Wherein MME/S-GW 211 is connected to gNB 221 and gNB 222 via S1-U interfaces, and MME/S-GW 211 is connected to eNB 231 and eNB 232 via S1 interfaces. MME/S-GW 212 is connected to gNB 221 and gNB 222 through the S1-U interface, and MME/S-GW 212 is connected to eNB 231 and eNB 232 through the S1 interface. gNB 221 and gNB 222 are connected via X2-U. eNB 231 and eNB 232 are connected by X2. Similarly, eNB 231 and gNB 221 are connected by X2. The gNB 222 and eNB 232 are connected by X2. In other words, eNB and eNB are directly interconnected by using X2 interface, and eNB is connected to EPC through S1 interface. The S1 interface supports many-to-many connection between MME/S-GW and eNB, namely one eNB can be connected with a plurality of MME/S-GW, and a plurality of eNBs can also be connected to the same MME/S-GW at the same time. Similarly, the gNB and the gNB are directly interconnected by adopting an X2-U interface mode, and the gNB is connected to the EPC through an S1-U interface. The S1-U interface supports many-to-many connection between MME/S-GW and gNB, namely one gNB can be connected with a plurality of MME/S-GWs, and a plurality of gNB can also be connected to the same MME/S-GW at the same time.

As shown in fig. 2, in the embodiment of the present application, MME/S-GW 211 and MME/S-GW 212 belong to an Evolved Packet Core (EPC) of an LTE Network, and gbb 221, gbb 222, eNB 231, and eNB 232 constitute an Evolved Universal Terrestrial Radio Access Network (E-UTRAN). However, embodiments of the present application are not limited thereto, and for example, the MME/S-GW 211 and MME/S-GW 212 may be replaced with any core network device that communicates with an access network device.

Alternatively, the core network device may be a 5G core network device, such as an Access and Mobility Management Function (AMF), and a Session Management Function (SMF). Optionally, the Core network device may also be an Evolved Packet Core (EPC) device of the LTE network, for example, a Session Management Function + Core Packet Gateway (SMF + PGW-C) device of the Core network.

It is understood that SMF + PGW-C may perform the functions that SMF and PGW-C can perform simultaneously.

Optionally, in this embodiment, the AMF may perform information interaction with the SMF, for example, the SMF obtains some information of the radio access network side from the AMF.

As shown in fig. 3, in one scenario, the MN and the SN are respectively connected to an Evolved Packet Core (EPC) through S1-U interfaces, or the SN and the MN are respectively connected to the EPC through S1-U interfaces. For example, the MN may be a Long Term Evolution (LTE) Evolved Node B (eNB) with an SN of a 5G base station (gNB). Control plane S1-C terminates at LTE eNB). After the core network is divided, the data flow is independently transmitted through the MN and the SN, and the SN plays a role of load sharing, and this architecture may also be referred to as a 3A mode or scenario 3A. In this way, no special requirement is required for the backhaul between the base stations, no special configuration is required for the layer 2 protocol layer, no load sharing function exists between the base stations, and the peak rate completely depends on the wireless capability of the MN and the SN; in addition, in the process of switching, core network participation is needed, and the problem that data can be interrupted exists.

In another scenario, as shown in fig. 4, the MN has an S1-U connection with an Evolved Packet Core network (EPC), or the MN is connected to the EPC through an S1-U interface. For example, the MN may be a Long Term Evolution (LTE) Evolved Node B (eNB) with an SN of a 5G base station (gNB). The control plane S1-C terminates at the LTE eNB. All downlink data streams are firstly transmitted to the MN, then are divided by the MN according to a certain algorithm and proportion, and then are transmitted to the SN by the X2 interface, and finally are simultaneously transmitted to the UE on the MN and the SN, and the structure can also be called as a 3 mode or a scene 3. In this way, the user acquires downlink data from 2 systems, which is convenient for realizing load sharing and resource coordination functions and is also beneficial to improving the user rate. In addition, the handover process has less impact on the core network, and the handover delay is low due to the presence of multiple radio links. The method has the disadvantages of high requirements on the backhaul between the base stations, high requirements on the complexity of the layer 2 protocol, and the realization of functions such as flow control and the like on the backhaul between the base stations. In addition, the split bearer approach is only applicable in the downlink direction. In the uplink direction, data flow is not divided, and can be transmitted through the MN or the SN.

Further, in a dual-connectivity network architecture (e.g., network architecture 200), data radio bearers may be serviced independently by the MN or the SN, or both. A MCG bearer (bearer), i.e. a group of serving cells controlled by the MN, when served only by the MN, a SCG bearer, i.e. a group of serving cells controlled by the SN, when served only by the SN, a split bearer, also known as a split bearer, when served by the MN and the SN. Specifically, it can be classified into MCG split bearer and SCG split bearer. The MCG split bearer and the SCG split bearer mainly lie in that functions of Packet Data Convergence Protocol (PDCP) layers are different from keys of PDCP layers.

As shown in fig. 5, the bearer of the terminal device at DC may include: MCG bearers at MN for termination (MN terminated MCG bearer), forked bearers at MN for termination (MN terminated split bearer), SCG bearers at MN for termination (MN terminated SCG bearer), MCG bearers at SN for termination (SN terminated MCG bearer), forked bearers at SN for termination (SN terminated split bearer), and SCG bearers at SN for termination (SN terminated SCG bearer).

In other words, the bearer may be divided into bearers with termination points at MN or SN based on whether the Packet Data Convergence Protocol (PDCP) with bearers passing through is located at MN or SN, and may also be divided into MCG bearers or SCG bearers based on Radio Link Control (RLC) with bearers passing through.

The MCG bearer, SCG bearer, and split bearer (split bearer) served by MN and/or SN reach a Media Access Control (MAC) layer of the corresponding E-UTRA or NR through a corresponding Evolved Universal Terrestrial Radio Access (Evolved Universal Terrestrial Radio Access), E-UTRA) Radio Link Control (Radio Link Control, RLC) or New Radio, NR RLC layer. Alternatively, the forked bearer at the MN at the termination and the forked bearer at the SN at the termination may be collectively referred to as a forked bearer (Split bearer). Alternatively, the split bearer may also be referred to as a split bearer.

It should be understood that each sub-layer may send data to a designated layer of the receiving end according to the difference of the data of the pdu. Data entering each sublayer without being processed is called Service Data Unit (SDU), and Data processed by the sublayer to form a specific format is called Protocol Data Unit (PDU). An SDU is an information unit transferred from a higher layer protocol to a lower layer protocol. The raw data of the SDU is PDU of the upper layer of the protocol. That is, the PDU formed in the current layer is the SDU in the next layer.

For example, each logical channel of each terminal device has one RLC entity (RLC entity), and data received by the RLC entity from the PDCP layer or data addressed to the PDCP layer may be referred to as RLC SDU (or PDCP PDU). Data received by the RLC entity from the MAC layer or data addressed to the MAC layer may be referred to as RLC PDUs (or MAC SDUs).

Illustratively, in this embodiment of the application, the RLC layer is located between the PDCP layer and the MAC layer, and the RLC layer may communicate with the PDCP layer through a Service Access Point (SAP) and communicate with the MAC layer through a logical channel. The embodiments of the present application are not limited thereto.

It should be noted that fig. 1 to 5 are only examples of the present application and should not be construed as limiting the present application.

For example, the network architecture 200 shown in fig. 2 is merely an exemplary depiction of a Dual Connectivity (DC) network architecture and embodiments of the present invention are not limited in this respect. For example, in other alternative embodiments, simple modifications to the network architecture 200 are possible. For example, as one example, the MN and SN may not be connected to the EPC core network, but rather connected to a 5GC core network, i.e., a DC network framework under the 5GC core network. Illustratively, the DC network architecture includes, but is not limited to: NE-DC,5GC-EN-DC and NR DC. NR in the NE-DC serves as an MN node, eLTE serves as an SN node, and the MN and the SN are respectively connected with a 5GC core network. In the 5GC-EN-DC, eLTE is used as an MN node, NR is used as an SN node, and MN and SN are respectively connected with a 5GC core network. In NR DC, NR is used as MN node, NR is used as SN node, and MN and SN are respectively connected with a 5GC core network.

Fig. 6 is a schematic block diagram of a DC bearer under a 5GC core network according to an embodiment of the present application.

As shown in fig. 6, the bearer of the terminal device under DC may also include: MCG bearers with termination at MN (MN terminated MCG bearer), forked bearers with termination at MN (MN terminated split bearer), SCG bearers with termination at MN (MN terminated SCG bearer), MCG bearers with termination at SN (SN terminated MCG bearer), forked bearers with termination at SN (SN terminated split bearer) and SCG bearers with termination at SN (SN terminated SCG bearer).

The MN and the SN are respectively connected to a 5GC core network, the MN is connected to the SN through an Xn interface, the MN and the SN can respectively receive a Quality of Service (QoS) stream sent by the 5GC core network, and the QoS stream can be borne on a corresponding bearer after passing through a Service Data Attachment Protocol (SDAP). MCG bearers (bearer), SCG bearers and split bearers (split bearer) served by the MN and/or SN go through the respective MN RLC layer or SN RLC layer to reach the respective MN MAC layer or NR MAC layer.

In this embodiment, the bearer terminated at the MN by the termination node may also be referred to as a bearer terminated by the MN, and the bearer terminated at the SN by the termination node may also be referred to as a bearer terminated by the SN.

In a Multi-RAT Dual Connectivity (MR-DC) scenario, the bearer types from the UE-side and network-side perspective may include: the bearer is divided into an MN-terminated bearer and an SN-terminated bearer from the node where the PDCP resides.

The method is divided into the following aspects from the perspective of used wireless resources: MCG bearers, SCG bearers and split bearers.

Each DRB is an MCG or SCG or split bearer terminated by an MN or SN.

The network side configures a key to be used, i.e., a master key (master key) or a secondary key (secondary key), for each DRB.

In order to reduce air interface signaling, quickly recover wireless connection and quickly recover data service in a 5G network environment, a new Radio Resource Control (RRC) state, that is, an RRC _ INACTIVE state, is defined. This state is distinguished from the RRC _ IDLE and RRC _ CONNECTED states.

In RRC _ IDLE state: the mobility is cell selection and reselection based on terminal equipment, paging is initiated by a Core Network (CN), and a paging area is configured by the CN. The base station side does not have Access Stratum (AS) context of the terminal equipment, and does not have RRC connection.

In RRC _ CONNECTED state: there is an RRC connection and the base station and the terminal device have a terminal device AS context. The network device knows that the location of the terminal device is at a particular cell level. Mobility is network device controlled mobility. Unicast data may be communicated between the terminal device and the base station.

RRC _ INACTIVE: mobility is cell selection and reselection based on terminal equipment, connection between CN-NR exists, the AS context of the terminal equipment exists on a certain base station, paging is triggered by a Radio Access Network (RAN), a paging area based on the RAN is managed by the RAN, and the Network equipment knows that the position of the terminal equipment is based on the paging area level of the RAN.

It should be noted that, in the embodiment of the present application, the inactive state may also be referred to as a deactivated state, which is not limited in the present application.

The network device may control the state transition of the terminal device, for example, as shown in fig. 7, the terminal device in the RRC _ CONNECTED state may enter the RRC _ IDLE state by releasing the RRC connection; the terminal device in the RRC _ IDLE state can enter the RRC _ CONNECTED state by establishing an RRC connection; the UE in the RRC _ CONNECTED state may enter the RRC _ INACTIVE state by suspending Release (Release with Suspend) of the RRC connection; the UE in the RRC _ INACTIVE state may enter the RRC _ CONNECTED state by restoring (Resume) the RRC connection and may also enter the RRC _ IDLE state by releasing the RRC connection.

It should be noted that, the terminal device is in the RRC _ INACTIVE state, and the terminal device autonomously returns to the idle state in the following cases:

when receiving the initial paging message of CN;

when an RRC recovery request is initiated, a timer T319 is started, and if the timer is overtime;

when the integrity protection verification of the random access Message4 (Message 4, MSG 4) based on competition fails;

when a cell reselects to other Radio Access Technology (RAT);

and entering a residing any cell (camp on any cell) state.

Features of the RRC _ INACTIVE state:

connection between RAN and CN;

the terminal equipment and at least one gNB save AS context;

the terminal equipment is accessible to the RAN side, and related parameters are configured by the RAN;

when the terminal device moves in a RAN Notification Area (RNA) configured by the RAN, it is not necessary to notify the network side (core network device), but when the terminal device moves out of the RNA, it is necessary to notify the network side (core network device);

the UE moves within the RNA according to the cell selection reselection mode.

Specifically, the RNA may be as shown in fig. 8, and in the RNA shown in fig. 8, the terminal device does not need to be notified to the network side when moving between the base stations 1 to 5, but needs to be notified to the network side when moving to the base station 6 or 7.

When the terminal device is in the RRC _ INACTIVE state, the network device configures configuration parameters of RRC _ INACTIVE, such as configuration RNA, to the terminal device through RRC Release dedicated signaling, where the configuration parameters are used to control an area where the terminal device performs cell selection and reselection in the INACTIVE state, and the area is also an initial paging range area of the RAN.

When the terminal device moves in the RNA area, the network side is not informed, and the mobility behavior in an idle (idle) state, namely the cell selection reselection principle, is followed. When the terminal device moves out of the paging area configured by the RAN, the terminal device is triggered to recover the RRC connection and reacquire the paging area configured by the RAN. When downlink data arrives at the terminal equipment, the gNB maintaining the connection between the RAN and the CN for the terminal equipment triggers all cells in the RAN paging area to send paging messages to the terminal equipment, so that the terminal equipment in the INACTIVE state can recover RRC connection and receive the data. The terminal device in the INACTIVE state configures a RAN paging area, and in order to ensure the accessibility of the terminal device in the area, the terminal device needs to perform periodic location update according to a network configuration period.

Therefore, the scenario triggering the terminal device to perform RNA Update includes that a RAN Notification Area Update (RNAU) timer expires or the UE moves to an Area other than the RNA.

It should be noted that, when the target base station that the terminal device initiates the RRC connection recovery procedure is not an anchor base station, the anchor base station determines whether to transfer the context of the terminal device to the target base station. Therefore, the target base station generally sends a cause value (cause) carried in the RRC connection resume request message initiated by the terminal device to the anchor base station in the context claim process of the terminal device, and the anchor base station determines whether the context of the terminal device needs to be transferred to the target base station. For example, periodic RAN location updates typically do not require context transfers.

For example, as shown in fig. 9, the RNAU in which the context migration exists is specifically implemented as the flow described in S11 to S19 below.

S11, the terminal equipment (UE) sends an RRC connection recovery Request (Resume Request) to a target base station (gNB), wherein the RRC connection recovery Request is used for RNA updating;

s12, the target base station sends a REQUEST (RETRIEVE UE CONTEXT REQUEST) for extracting UE CONTEXT to an anchor base station (also called Last Serving gNB);

s13, the anchor base station sends a RESPONSE (RETRIEVE UE CONTEXT RESPONSE) for extracting the UE CONTEXT to the target base station;

s14, setting the UE to be in an INACTIVE state (Send UE to INACTIVE);

s15, the target base station sends a DATA FORWARDING ADDRESS INDICATION (DATA FORWARDING ADDRESS INDICATION) to the anchor base station (optional);

s16, the target base station sends a path switching request to an Access and Mobility Management Function (AMF) entity;

s17, the AMF entity sends a path switching response to the target base station;

s18, the target base station sends RRC release information to the terminal equipment;

and S19, the target base station sends a UE context release message to the anchor base station.

For another example, as shown in fig. 10, the RNAU without context migration is specifically realized by the following flow described in S21 to S24.

S21, the terminal equipment (UE) sends an RRC connection recovery Request (Resume Request) to a target base station (gNB), wherein the RRC connection recovery Request is used for RNA updating;

s22, the target base station sends a REQUEST (RETRIEVE UE CONTEXT REQUEST) for extracting UE CONTEXT to an anchor base station (also called Last Serving gNB);

s23, the anchor base station sends FAILURE (RETRIEVE UE CONTEXT FAILURE) of extracting the UE CONTEXT to the target base station;

and S24, the target base station sends an RRC release message to the terminal equipment.

In LTE, small data transmission (EDT) is introduced, and in the process, a terminal device may always remain in an idle (idle) state, a suspend (suspend) state, or an inactive (inactive) state, and complete transmission of uplink and/or downlink small data packets. For example, as shown in fig. 11, the user plane data transmission scheme may be specifically implemented by the following flows from S31 to S38.

S31, the UE sends an RRC connection recovery Request (Resume Request) to the eNB, wherein the RRC connection recovery Request comprises uplink data (namely small data transmission) sent by the UE;

s32, the eNB sends a UE CONTEXT recovery REQUEST (UE CONTEXT RESUME REQUEST) to a Mobility Management Entity (MME);

s33, modifying the load bearing between the MME and a Serving Gateway (SGW);

s34. The MME sends a UE CONTEXT recovery RESPONSE (UE CONTEXT RESUME RESPONSE) to the eNB;

s35, the eNB sends uplink data (namely small data transmission) sent by the UE to the SGW;

s36, the SGW receives downlink data sent by the eNB (optionally);

s37, suspending the flow between the eNB and the SGW, and modifying the load between the MME and the SGW;

s38. The enb sends an RRC connection release message to the UE, optionally, the RRC connection release message includes downlink data.

Meanwhile, in the R17DCCA enhancement subject, the concept of SCG deactivation is introduced, i.e., transmission on the SCG side is suspended even if the UE is in the RRC connected state. SCG deactivation is introduced primarily for UE power saving purposes. Therefore, a data transmission configuration method and a key configuration method in an MR-DC scenario are needed, so that data transmission in the MR-DC scenario does not activate SCG side radio resources as much as possible, and thus the energy saving purpose of the UE in the small data transmission process is achieved.

It should be understood that the embodiments of the present application may be applicable to a small data transmission scenario, and certainly may also be applicable to a normal data transmission scenario, and the present application is not limited thereto.

It should also be understood that the embodiments of the present application may be applied to MR-DC scenarios, or may also be applied to other dual-connection or multi-connection scenarios described in the foregoing embodiments, and the present application is not limited thereto.

First, a configuration method of data transmission in an MR-DC scenario is described with reference to fig. 12, which is denoted as embodiment one.

Example one

Fig. 12 is a schematic interaction diagram of a data transmission method 400 provided in an embodiment of the present application. As shown in fig. 12, the method 400 includes at least some of the following.

S401, a terminal device receives first configuration information, wherein the first configuration information is used for configuring small data transmission configuration corresponding to a Data Radio Bearer (DRB);

s402, the terminal device transmits small data according to the first configuration information.

Optionally, the first configuration information may be configured by a first node, and the first node may be a primary node (MN) or a Secondary Node (SN). For example, the first Node may be any one of the 5G base station (gNB) 221, gNB 222, evolved Node B (eNB) 231, eNB 232 shown in fig. 2. The terminal device may be a terminal device as shown in fig. 1.

In some embodiments, when the terminal device is in a connected state, the first node may configure the first configuration information for the terminal device through a downlink message, for example, the downlink message may be RRC signaling.

The first configuration information may be used to configure a DRB capable of performing small data transmission when the terminal device is in an inactive state, or a DRB incapable of performing small data transmission when the terminal device is in an inactive state.

Optionally, in this embodiment of the present application, the DRB may include the following types:

MN terminated MCG bearers (MN terminated MCG bearers), MN terminated split bearers (MN terminated split bearers), MN terminated SCG bearers (MN terminated SCG bearers), SN terminated MCG bearers (SN terminated MCG bearers), SN terminated split bearers (SN terminated split bearers), SN terminated SCG bearers (SN terminated SCG bearers).

Example 1: the first configuration information is used for configuring the DRB capable of being used for small data transmission when the terminal device is in an inactive state, and includes: MN terminated MCG bearer. I.e. only the MN terminated MCG bearer can be used for small data transmissions when the UE is in the inactive state.

Example 2: the first configuration information is used for configuring the DRB capable of being used for small data transmission when the terminal device is in an inactive state, and includes: MN-terminated MCG bearer and SN-terminated MCG bearer, i.e. only MCG bearers can be used for small data transmissions when the UE is in an inactive state.

Example 3: the first configuration information is used for configuring the DRB capable of being used for small data transmission when the terminal device is in an inactive state, and includes: MN terminated MCG bearer, MN terminated split bearer, SN terminated MCG bearer, and SN terminated split bearer. I.e. only SCG bearers cannot be used for small data transmissions when the UE is in the inactive state.

The embodiment of the present application does not limit the presentation form of the first configuration information, and a table manner may be adopted, as an example, as shown in table 1.

TABLE 1

DRB

Option 1

Option 2

Option 3

MN terminated MCG bearer	1	1	1
MN terminated split bearer	1	0	0
MN terminated SCG bearer	0	0	0
SN terminated MCG bearer	1	1	0
SN terminated split bearer	1	0	0
SN terminated SCG bearer	0	0	0

Where "1" indicates that the corresponding bearer can be used for small data transmission, and "0" indicates that the corresponding bearer cannot be used for small data transmission.

Option 1 may correspond to example 3, option 2 to example 2, and option 3 to example 1.

For the DRB configured to be incapable of performing small data transmission, when small data arrives, the terminal device needs to enter a connected state for data transmission.

In some embodiments, if the split bearer is configured to be capable of being used for small data transmission, in order to not activate the radio resource on the SCG side, in this embodiment of the present application, the first configuration information may also be used to configure a path, or leg (leg), activated when the split bearer is used for small data transmission.

For example, for MN terminated split bearer and SN terminated split bearer, the path activated when small data transmission is performed may be configured to be an MCG path, i.e., an MCG leg. Thus, the SCG path may not be activated when the split bearer is used for small data transmission, that is, the radio resource on the SCG side may not be activated.

Information on the activated path for small data transmission can be further configured for option 1, as shown in table 2 below.

TABLE 2

DRB	Option 1	Bearer for carrying small data
MN terminated MCG bearer	1
MN terminated split bearer	1	Activation of MCG leg only
MN terminated SCG bearer	0
SN terminated MCG bearer	1
SN terminated split bearer	1	Activation of MCG leg only
SN terminated SCG bearer	0

The configuration method of the key in the MR-DC scenario is described with reference to fig. 13, which is denoted as embodiment two.

Example two

Fig. 13 is a schematic diagram of a data transmission method 500 according to another embodiment of the present application. As shown in fig. 13, the method 500 includes at least some of the following.

S501, the terminal device generates an SCG key according to a master cell group MCG key and an auxiliary cell group SCG counting value under the condition that specific conditions are met, and the SCG key is used for encryption and decryption of the cell data.

In the second embodiment, in order to support small data transmission on the bearer terminated by the SN, a configuration method of a corresponding key is designed.

Optionally, in some embodiments, the MCG key is a master key before the terminal device initiates the small data transmission, or is a master key updated by triggering the small data transmission.

For uplink small data transmission, the SCG key may be used for encryption of uplink small data.

For example, when uplink small data arrives, or uplink data arrives at a PDCP entity terminated by an SN or a bearer associated with a "secondary" key, the terminal device may generate the SCG key according to the MCG key and the SCG count value.

For downstream small data transmission, the SCG key may be used for decryption of downstream small data.

For example, when there is a bearer terminating when downlink small data arrives at the SN, the SN may send a first message to the MN, where the first message is used to trigger the MN to page the terminal device, and further carries an indication related to small data transmission and/or key generation in a paging message.

Optionally, in some embodiments, the first message comprises at least one of:

a small data arrival indication for indicating whether small data arrives;

an SCG key derivation indication for indicating whether to generate an SCG key;

list of DRB IDs where small data arrives.

Optionally, in some embodiments, the paging message comprises at least one of:

a small data arrival indication for indicating whether small data arrives;

an SCG key derivation indication for indicating whether to generate an SCG key;

list of DRB IDs where small data arrives.

Optionally, in some embodiments, the terminal device may generate the SCG key according to the MCG key and the SCG count value when receiving the paging message, regardless of whether the paging message indicates generation of the SCG key.

Optionally, in other embodiments, the terminal device may generate the SCG key according to the MCG key and the SCG count value when receiving the paging message indicating that downlink data arrives, or downlink small data arrives, or a bearer terminated by an SN, whether the paging message indicates generation of the SCG key or not.

Optionally, in still other embodiments, the terminal device may generate the SCG key according to the MCG key and the SCG count value when receiving the paging message indicating that the SCG key is generated, regardless of whether the paging message indicates that the SCG key is generated.

Optionally, in some embodiments, the SCG count value is configured by a radio resource control, RRC, release (Release) message.

A data transmission method on an SCG bearer terminated by an SN in an MR-DC scenario is described with reference to fig. 14 to fig. 25, which is denoted as an embodiment three. Two scenarios are included: a downlink data arrival scenario and an uplink data arrival scenario.

It should be understood that the third embodiment may be implemented separately, that is, when small data reaches the SCG bearer terminated by the SN, the small data transmission on the SCG bearer without using SCG resources is implemented through cooperation between the terminal device, the SN, and the MN. Or the third embodiment may also be implemented in combination with other embodiments, for example, the third embodiment may be that, in a case that the SCG bearer terminated by the SN configured by the first configuration information in the first embodiment is capable of performing small data transmission, the small data transmission on the SCG bearer is realized through cooperation between the terminal device, the SN, and the MN without using SCG resources.

Optionally, in some embodiments, the first configuration information may also be used to configure the data transmission method in the third embodiment. Therefore, the terminal equipment can realize the small data transmission under the condition of not activating the SCG resource when the small data reaches the SCG bearer terminated by the SN based on the first configuration information.

The technical solution of the downstream data arrival scenario is explained with reference to fig. 14 to 23.

Fig. 14 is a schematic interaction diagram of a data transmission method 600 according to yet another embodiment of the application. As shown in fig. 14, the method 600 includes at least some of the following.

S601, when the first auxiliary cell group SCG bearing at the auxiliary node SN has the arrival of the downlink small data, the SN sends the information of the downlink small data to the main node MN,

s602, the MN generates a first Media Access Control (MAC) Protocol Data Unit (PDU) according to the information of the downlink small data, wherein the first MAC PDU comprises an RLC PDU or a PDCP PDU corresponding to the downlink small data from the SN;

s603, the MN sends the first MAC PDU to the terminal equipment.

Correspondingly, the terminal equipment receives the first MAC PDU sent by the MN.

Alternatively, in some embodiments, the MN and the SN may be any two of the 5G base station (gNB) 221, the gNB 222, the Evolved Node B (eNB) 231, and the eNB 232 shown in fig. 2. The terminal device may be a terminal device as shown in fig. 1.

Optionally, in some embodiments, the information of the downlink small data includes at least one of:

a radio link control RLC PDU or a PDCP PDU corresponding to the downlink small data;

a Logical Channel Identity (LCID) to which the downlink small data belongs;

a DRB ID to which the downlink small data belongs;

and a Quality of Service (QoS) parameter corresponding to the downlink small data.

A specific implementation is described in conjunction with fig. 15.

As shown in fig. 15, when the downlink small data arrives at the first SCG bearer, the SN may generate RLC PDUs or PDCP PDUs on the first SCG bearer, and further may send the RLC PDUs or PDCP PDUs corresponding to the downlink small data and/or the configuration corresponding to the downlink small data to the MN, where the configuration of the downlink small data may include at least one of the following:

LCID to which the downlink small data belongs;

the DRB ID to which the downlink small data belongs, that is, the DRB ID carried by the first SCG;

and QoS parameters corresponding to the downlink small data.

The configuration of the downlink small data may be used for the MN to generate a corresponding MAC PDU.

In some embodiments, the information of the downlink small data may be sent through interface signaling between network devices, for example, xn interface signaling, or may be sent to the MN through an RRC forwarding (Transfer) message. When the RRC Transfer message is used to carry the above information, the RLC PDU or PDCP PDU corresponding to the small downlink data is included in the RRC Transfer message in a container (container).

After receiving the information of the downlink small data sent by the SN, the MAC entity of the MN may generate a first MAC PDU according to the RLC PDU or PDCP PDU corresponding to the downlink small data. In some embodiments, the RLC PDU or PDCP PDU corresponding to the downlink small data and a message carried in a Common Control Channel (CCCH) may be multiplexed in the first MAC PDU. That is, the MN may generate the first MAC PDU according to the RLC PDU or the PDCP PDU and the message in the CCCH.

In some embodiments, the first MAC PDU may include first indication information for indicating that the downlink small data is from the first SCG bearer, i.e., the first MAC PDU includes data from the SCG bearer.

In some embodiments, the first indication information is carried in a header of a first MAC SDU in the first MAC PDU, where the first MAC SDU is a MAC SDU in the first MAC PDU for carrying an RLC PDU or a PDCP PDU. For example, the first indication information is carried in a reserved (R) field in a header of the first MAC SDU.

Fig. 16 to fig. 22 show several typical header formats of MAC SDUs, for example, a value of the R field may be set to 0 to indicate that data in the MAC SDU comes from an MCG bearer, a value of 1 to indicate that the data comes from an SCG side bearer, or vice versa.

Optionally, the LCID in the packet header of the first MAC SDU may be generated according to the LCID corresponding to the downlink small data.

After the MN generates the first MAC PDU, the MN may submit the first MAC PDU to the physical layer of the MN and further send the first MAC PDU to the terminal device, after receiving the first MAC PDU, the MCG MAC entity of the terminal device may decode the first MAC PDU, and the determination method of the key used for decoding may refer to the relevant description in the second embodiment.

After the first MAC PDU is decoded, obtaining the first indication information in a first MAC SDU in the first MAC PDU, determining whether data in the first MAC SDU is from an SCG bearer, and if it is determined that the data is from the SCG bearer, the MCG MAC entity of the terminal device may send an LCID corresponding to the first MAC SDU and/or the downlink small data to the SCG MAC entity of the terminal device.

Further, the SCG MAC entity of the terminal device may deliver the received first MAC SDU to a higher layer. Specifically, the SCG MAC entity of the terminal device may decode the first MAC SDU according to the LCID corresponding to the small downlink data, and deliver the decoded data to a higher layer of the terminal device.

It should be understood that, in this embodiment of the present application, the MCG MAC entity of the terminal device may refer to a MAC entity of the terminal device on the MN side, the SCG MAC entity of the terminal device may refer to a MAC entity of the terminal device on the SN side, and the terminal device may respectively correspond to corresponding MAC entities on the MN side and the SN side.

Technical scheme for uplink small data arrival scene is explained with reference to fig. 23 and 24

Fig. 23 is a schematic interaction diagram of a data transmission method 700 according to another embodiment of the application. As shown in fig. 23, the method 700 includes at least some of the following.

S701, under the condition that uplink small data arrive on a second auxiliary cell group SCG bearing which is ended at an auxiliary node SN, terminal equipment sends a second MAC PDU to a main node MN, wherein the second MAC PDU comprises an RLC PDU or a PDCP PDU corresponding to the uplink small data;

s702, the MN decodes the second MAC PDU and sends a second MAC SDU which carries the RLC PDU or the PDCP PDU corresponding to the uplink small data in the second MAC PDU to an SN;

s703, the SN decodes the second MAC SDU.

Further optionally, the SN delivers the decoded data to a core network side, such as a UPF entity.

Alternatively, in some embodiments, the MN and the SN may be any two of the 5G base station (gNB) 221, the gNB 222, the Evolved Node B (eNB) 231, and the eNB 232 shown in fig. 2. The terminal device may be the terminal device shown in fig. 1.

A specific implementation process is described in conjunction with fig. 24.

As shown in fig. 24, when the uplink small data arrives at the second SCG bearer, the terminal device may generate an RLC PDU or a PDCP PDU on the second SCG bearer, and further may send the RLC PDU or the PDCP PDU corresponding to the uplink small data and/or the configuration corresponding to the downlink small data to an MCG MAC entity of the terminal device, where the configuration of the downlink small data may include at least one of the following:

the LCID to which the uplink small data belongs;

the DRB ID to which the uplink small data belongs, that is, the DRB ID carried by the first SCG;

and QoS parameters corresponding to the uplink small data.

After receiving the information, the MCG MAC entity of the terminal device may generate a second MAC PDU according to the information, where the second MAC PDU includes an RLC PDU or a PDCP PDU corresponding to the uplink small data.

In some embodiments, a message (e.g., an RRC message) carried in the RLC PDU or PDCP PDU and CCCH corresponding to the uplink small data may be multiplexed in the second MAC PDU. That is, the MCG MAC entity of the terminal device may generate the second MAC PDU according to the RLC PDU or PDCP PDU and the message in the CCCH.

Optionally, in some embodiments, the second MAC PDU may include second indication information used to indicate that the uplink small data is from an SCG bearer, that is, the second MAC PDU includes data from the SCG bearer.

In some embodiments, the second indication information is carried in a packet header of a second MAC SDU in the second MAC PDU, where the second MAC SDU is a MAC SDU used for carrying an RLC PDU or a PDCP PDU corresponding to the uplink small data in the second MAC PDU.

In some embodiments, the second indication information is carried in a header of the second MAC SDU, for example, an R field of the second MAC SDU.

Fig. 16 to fig. 22 show several typical packet header formats of MAC SDUs, for example, setting the value of the R field to 0 may indicate that data comes from an MCG bearer, and setting the value to 1 indicates that data comes from an SCG side bearer, or vice versa.

Optionally, the LCID in the packet header of the second MAC SDU may be generated according to the LCID corresponding to the uplink small data.

After the MCG MAC entity of the terminal device generates the second MAC PDU, the second MAC PDU may be delivered to a physical layer and further sent to the MN, and after receiving the second MAC PDU, the MAC entity of the MN may decode the second MAC PDU.

After the second MAC PDU is decoded, obtaining the second indication information in the second MAC SDU in the second MAC PDU, and determining whether data in the second MAC SDU is from an SCG bearer, where if the data is from the SCG bearer, the MAC entity of the MN may send the second MAC SDU and/or the LCID corresponding to the uplink small data to the SN.

In some embodiments, the second MAC SDU and/or the LCID corresponding to the uplink small data may be sent through interface signaling between network devices, for example, xn interface signaling, or may be sent to the MN through an RRC forward (Transfer) message. When the RRC Transfer message is used to carry the above message, the RLC PDU or PDCP PDU corresponding to the uplink small data is included in the RRC Transfer message in the form of a container (container).

Further, after receiving the second MAC SDU and/or the LCID corresponding to the uplink small data, the SN may decode the second MAC SDU according to the LCID corresponding to the uplink small data, and further deliver the decoding result to a core network side, such as a UPF entity.

In summary, when the small data reaches the bearer terminated by the SN, the MN forwards the small data to be transmitted, so that the small data to be transmitted is transmitted to the target end without activating the radio resource on the SCG side, thereby achieving the purpose of the node of the UE in the small data transmission.

It should be understood that the foregoing first, second and third embodiments may be implemented alone or in combination, and are not modern in this application.

The preferred embodiments of the present application have been described in detail with reference to the accompanying drawings, however, the present application is not limited to the details of the above embodiments, and various simple modifications can be made to the technical solution of the present application within the technical idea of the present application, and these simple modifications are all within the protection scope of the present application. For example, the various features described in the foregoing detailed description may be combined in any suitable manner without contradiction, and in order to avoid unnecessary repetition, various combinations that may be made are not described separately in this application. For example, various embodiments of the present application may be arbitrarily combined with each other, and the same should be considered as the disclosure of the present application as long as the concept of the present application is not violated.

Method embodiments of the present application are described in detail above in conjunction with fig. 12-24, and apparatus embodiments of the present application are described in detail below in conjunction with fig. 25-29.

Fig. 25 shows a schematic block diagram of a terminal device 800 according to an embodiment of the application. As shown in fig. 25, the terminal apparatus 800 includes:

the communication unit 810 is configured to receive first configuration information, where the first configuration information is used to configure a small data transmission configuration corresponding to a data radio bearer DRB; and

and carrying out small data transmission according to the first configuration information.

Optionally, in some embodiments, the first configuration information is used to configure a radio data bearer DRB that can be used for small data transmission and/or a DRB that cannot be used for small data transmission.

Optionally, in some embodiments, the DRB capable of being used for small data transmission includes: the termination is carried in the master cell group MCG of the master node MN.

Optionally, in some embodiments, the DRB capable of being used for small data transmission includes: the termination point is carried by the MCG of the MN; the termination point is carried by the MCG of the secondary node SN.

Optionally, the DRB capable of being used for small data transmission includes: the termination point is carried by the MCG of the MN; split bearer of the termination point at the MN; the termination point is carried by the MCG of the SN; the termination point is at the split bearer of the SN.

Optionally, in some embodiments, if the DRB capable of being used for small data transmission includes a split bearer, the first configuration information is further used for configuring a path activated when the split bearer is used for small data transmission.

Optionally, in some embodiments, the path activated when the split bearer is used for small data transmission is an MCG path corresponding to the split bearer.

Optionally, the terminal device further includes: and the processing unit is used for generating an SCG key according to the MCG key and the SCG counting value under the condition that a specific condition is met, wherein the SCG key is used for encryption and decryption of the small data.

Optionally, in some embodiments, the specific condition comprises at least one of:

the small data arrives at a packet data convergence protocol PDCP entity carried by the termination point at the SN;

the small data reaches a PDCP entity associated with the auxiliary key;

small uplink data arrive;

there is uplink data arriving;

receiving a paging message of MN, wherein the paging message is used for indicating to receive small data or generating the SCG key;

a paging message for the MN is received.

Optionally, in some embodiments, the paging message comprises at least one of: a small data arrival indication for indicating whether small data arrives;

an SCG key derivation indication for indicating whether to generate an SCG key;

list of DRB IDs where small data arrives.

Optionally, in some embodiments, the SCG count value is configured by a radio resource control, RRC, release message.

Optionally, in some embodiments, the MCG key is a master key before the terminal device initiates the small data transmission, or a master key that triggers the small data transmission to be updated.

Optionally, in some embodiments, if there is a first SCG bearer at the SN where the downlink small data arrives at the termination point, the communication unit 810 is further configured to: and receiving a first Media Access Control (MAC) Protocol Data Unit (PDU) sent by an MN, wherein the first MAC PDU comprises an RLC PDU or a PDCP PDU corresponding to the downlink small data from the SN.

Optionally, in some embodiments, the RLC PDU corresponding to the downlink small data and a message carried by a common control channel CCCH are multiplexed in the first MAC PDU; or the PDCP PDU corresponding to the downlink small data and the message carried by the CCCH are multiplexed in the first MAC PDU.

Optionally, the first MAC PDU further includes first indication information and/or a logical channel identifier LCID corresponding to the downlink small data, where the first indication information is used to indicate whether the downlink small data is from an SCG bearer.

Optionally, in some embodiments, the first indication information is carried in a packet header of a first MAC service data unit SDU, an LCID corresponding to the small downlink data is carried in the packet header of the first MAC SDU, the first MAC PDU includes the first MAC SDU, and the first MAC SDU is an MAC SDU used in the first MAC PDU and used for carrying an RLC PDU or PDCP PDU corresponding to the small downlink data.

Optionally, the first indication information is carried in a reserved field in the first MAC SDU.

Optionally, the terminal device 800 further includes: the processing unit is used for determining that the data in the first MAC PDU is from an SCG bearer according to the first indication information in the first MAC PDU at an MCG MAC layer;

the communication unit 810 is further configured to: and sending the LCID corresponding to the first MAC SDU and/or the downlink small data to an SCG MAC layer in the MCG MAC layer.

Optionally, the processing unit is further configured to: and decoding the first MAC SDU on the SCG MAC layer according to the LCID corresponding to the downlink small data, and delivering the decoded data to a high layer of the terminal equipment.

Optionally, in some embodiments, if there is uplink small data arriving at the second SCG bearer at the SN at the termination point, the communication unit 810 is further configured to: and sending a second MAC PDU to the MN at the MCG MAC layer, wherein the second MAC PDU comprises an RLC PDU or a PDCP PDU corresponding to the uplink small data.

Optionally, in some embodiments, the RLC PDU corresponding to the uplink small data and the message carried by the CCCH are multiplexed in the second MAC PDU; or the PDCP PDU and the message carried by the CCCH corresponding to the uplink small data are multiplexed in the second MAC PDU.

Optionally, in some embodiments, the terminal device 800 further includes:

a processing unit, configured to generate a radio link control RLC PDU from the small uplink data on an SCG RLC layer, and send the RLC PDU to an MCG MAC entity of the terminal device; or generating PDCP PDU by the uplink small data on the SCG PDCP layer, and sending the PDCP PDU to the MCG MAC entity of the terminal equipment.

Optionally, the processing unit is further configured to: transmitting, at the SCG RLC layer or the SCG PDCP layer, at least one of the following information to the MCG MAC layer: the LCID corresponding to the uplink small data, the DRB ID carried by the second SGC, and the QoS parameter of the uplink small data.

Optionally, in some embodiments, the processing unit is further configured to generate, at the MCG MAC layer, the second MAC PDU according to the RLC PDU corresponding to the uplink small data and a message in the CCCH; or generating the second MAC PDU at the MCG MAC layer according to the PDCP PDU and the CCCH message corresponding to the uplink small data.

Optionally, in some embodiments, the second MAC PDU further includes second indication information and/or an LCID corresponding to the uplink small data, where the second indication information is used to indicate that the uplink small data is from an SCG bearer.

Optionally, in some embodiments, the second indication information is carried in a packet header of a second MAC SDU, the LCID corresponding to the uplink small data is carried in the packet header of the second MAC SDU, the second MAC PDU includes the second MAC SDU, and the second MAC SDU is an RLC PDU or PDCP SDU used for carrying the uplink small data in the second MAC PDU.

Optionally, in some embodiments, the communication unit may be a communication interface or a transceiver, or an input/output interface of a communication chip or a system on a chip. The processing unit may be one or more processors.

It should be understood that the terminal device 800 according to the embodiment of the present application may correspond to a terminal device in the embodiment of the method of the present application, and the above and other operations and/or functions of each unit in the terminal device 800 are respectively for implementing corresponding processes of the terminal device in the embodiment of the method, and are not described herein again for brevity.

Fig. 26 is a schematic block diagram of a network node according to an embodiment of the present application. The network node 900 of fig. 26 comprises:

a communication unit 910, configured to send first configuration information to a terminal device, where the first configuration information is used to configure small data transmission configuration corresponding to a data radio bearer DRB.

Optionally, in some embodiments, the first configuration information is used to configure a radio data bearer DRB capable of being used for small data transmission and/or a DRB incapable of being used for small data transmission.

Optionally, the DRB capable of being used for small data transmission includes: the termination is carried in the master cell group MCG of the master node MN.

Optionally, the DRB capable of being used for small data transmission includes: the termination point is carried by the MCG of the MN;

the termination point is carried at the MCG of the secondary node SN.

Optionally, in some embodiments, the DRB capable of being used for small data transmission includes: the termination point is carried by the MCG of the MN; splitting bearer of the termination point at the MN; the termination point is carried by the MCG of the SN; the termination point is at the split bearer of the SN.

Optionally, in some embodiments, the first node is a MN.

Optionally, in some embodiments, the first node is further configured to configure an SCG count value for the terminal device, where the SCG count value is used for the terminal device to generate an SCG key for encryption and decryption of the small data according to an MCG key and the SCG count value.

Optionally, in some embodiments, the communication unit 910 is further configured to:

receiving a first message of an SN, wherein the first message is used for triggering the MN to page the terminal equipment, and when downlink small data arrives at a terminal node and is carried by the SN, the SN sends the first message;

and sending a paging message to the terminal equipment according to the first message, wherein the paging message comprises related indications of small data arrival and/or key generation.

Optionally, in some embodiments, the first message comprises at least one of:

a small data arrival indication for indicating whether small data arrives;

an SCG key derivation indication for indicating whether to generate an SCG key;

list of DRB IDs where small data arrives.

Optionally, in some embodiments, the paging message comprises at least one of:

a small data arrival indication for indicating whether small data arrives;

an SCG key derivation indication for indicating whether to generate an SCG key;

list of DRB IDs where small data arrives.

Optionally, in some embodiments, if the small downstream data arrives at the first SCG bearer at the SN at the termination point, the communication unit is further configured to:

and receiving the information of the downlink small data sent by the SN.

a Radio Link Control (RLC) PDU or a Packet Data Convergence Protocol (PDCP) Protocol Data Unit (PDU) corresponding to the downlink small data;

the logic channel identification LCID to which the downlink small data belongs;

the DRB ID to which the downlink small data belongs;

and the service quality QoS parameter corresponding to the downlink small data.

Optionally, in some embodiments, the information of the downlink small data is signaled through an Xn interface; or

And the information of the downlink small data is carried by an RRC forwarding message, wherein the RLC PDU or the PDCP PDU is contained in the RRC forwarding message in a container mode.

and sending a first Media Access Control (MAC) Protocol Data Unit (PDU) to the terminal equipment, wherein the first MAC PDU comprises an RLC PDU or a PDCP PDU corresponding to the downlink small data from the SN.

Optionally, in some embodiments, the RLC PDU corresponding to the downlink small data and a message carried by a common control channel CCCH are multiplexed in the first MAC PDU; or the PDCP PDU and the message carried by the CCCH corresponding to the downlink small data are multiplexed in the first MAC PDU.

Optionally, the first MAC PDU further includes first indication information and/or a logical channel LCID corresponding to the downlink small data, where the first indication information is used to indicate that the downlink small data is from an SCG bearer.

Optionally, in some embodiments, the first indication information is carried in a packet header of the first MAC service data unit SDU, the LCID corresponding to the small downlink data is carried in the packet header of the first MAC SDU, the first MAC PDU includes the first MAC SDU, and the first MAC SDU is a MAC SDU used for carrying an RLC PDU or PDCP PDU corresponding to the small downlink data in the first MAC PDU.

Optionally, in some embodiments, if the uplink small data arrives at the second SCG bearer at the terminal node at the SN, the communication unit 910 is further configured to: and receiving a second MAC PDU sent by the terminal equipment, wherein the second MAC PDU comprises an RLC PDU or a PDCP PDU corresponding to the uplink small data.

Optionally, in some embodiments, the RLC PDU corresponding to the uplink small data and the message carried by the CCCH are multiplexed in the second MAC PDU; or

And multiplexing the PDCP PDU corresponding to the uplink small data and the message carried by the CCCH in the second MAC PDU.

Optionally, in some embodiments, the second MAC PDU further includes second indication information and/or a logical channel LCID corresponding to the uplink small data, where the second indication information is used to indicate that the uplink small data comes from the second SCG bearer.

Optionally, in some embodiments, the second indication information is carried in a packet header of the second MAC SDU, the LCID corresponding to the uplink small data is carried in the packet header of the second MAC SDU, the second MAC PDU includes the second MAC SDU, and the second MAC SDU is a MAC SDU used for carrying an RLC PDU or PDCP PDU corresponding to the uplink small data in the second MAC PDU.

Optionally, the second indication information is carried in a reserved field in the second MAC SDU.

Optionally, in some embodiments, the network node 900 further includes:

a processing unit, configured to determine, according to the second indication information in the second MAC PDU, that data in the second MAC PDU is from an SCG bearer;

the communication unit is further configured to: and sending the LCID corresponding to the second MAC SDU and/or the uplink small data in the second MAC PDU to an SN.

Optionally, in some embodiments, the second MAC SDU and/or the LCID corresponding to the uplink small data are sent to the SN through an Xn interface signaling; or, the second MAC SDU and/or the LCID corresponding to the uplink small data is sent to the SN through an RRC forwarding message.

Optionally, in some embodiments, the first node is a SN.

and sending a first message to the MN under the condition that the terminal node has downlink data arriving on the bearer of the SN, wherein the first message is used for triggering the MN to page the terminal equipment.

Optionally, in some embodiments, the first message comprises at least one of: a small data arrival indication for indicating whether small data arrives;

an SCG key derivation indication for indicating whether to generate an SCG key;

list of DRB IDs where small data arrives.

Optionally, in some embodiments, if the small downstream data arrives at the termination point and is carried in the first SCG of the SN, the communication unit is further configured to: and sending the information of the downlink small data to the MN.

the logic channel identification LCID to which the downlink small data belongs;

the DRB ID to which the downlink small data belongs;

and the QoS parameter corresponds to the downlink small data.

The information of the downlink small data is carried by an RRC forwarding message, wherein the RLC PDU or the PDCP PDU is contained in the RRC forwarding message in a container mode.

Optionally, in some embodiments, if the small uplink data arrives at the destination node and is carried on the second SCG of the SN, the communication unit is further configured to:

and receiving the information of the uplink small data from the terminal equipment, which is sent by the MN.

Optionally, in some embodiments, the information of the uplink small data is sent through Xn interface signaling; or, the information of the uplink small data is sent through an RRC forwarding message.

Optionally, in some embodiments, the information of the uplink small data includes at least one of:

a second MAC SDU corresponding to the uplink small data, where the second MAC SDU is used to carry an RLC PDU or PDCP PDU corresponding to the uplink small data;

and the logical channel identifier LCID to which the uplink small data belongs.

Optionally, in some embodiments, the network node further comprises:

a processing unit, configured to decode the second MAC SDU according to the LCID to which the uplink small data belongs;

the communication unit is further configured to deliver the decoding result to the core network.

It should be understood that the network node 900 according to the embodiment of the present application may correspond to a network device in the embodiment of the method of the present application, and the above and other operations and/or functions of each unit in the network node 900 are respectively for implementing corresponding flows of the SN or the MN in the embodiment of the method, and are not described herein again for brevity.

Fig. 27 is a schematic structural diagram of a communication device 1000 according to an embodiment of the present application. The communication device 1000 shown in fig. 27 includes a processor 1010, and the processor 1010 can call and run a computer program from a memory to implement the method in the embodiment of the present application.

Optionally, as shown in fig. 28, the communication device 1000 may further include a memory 1020. From the memory 1020, the processor 1010 may call and execute a computer program to implement the method in the embodiment of the present application.

The memory 1020 may be a separate device from the processor 1010 or may be integrated into the processor 1010.

Optionally, as shown in fig. 28, the communication device 1000 may further include a transceiver 1030, and the processor 1010 may control the transceiver 1030 to communicate with other devices, and specifically, may transmit information or data to the other devices or receive information or data transmitted by the other devices.

The transceiver 1030 may include a transmitter and a receiver, among others. The transceiver 1030 may further include antennas, and the number of antennas may be one or more.

Optionally, the communication device 1000 may specifically be a network node in the embodiment of the present application, for example, an SN or an MN, and the communication device 1000 may implement a corresponding process implemented by the SN or the MN in each method in the embodiment of the present application, which is not described herein again for brevity.

Optionally, the communication device 1000 may specifically be a mobile terminal/terminal device according to this embodiment, and the communication device 1000 may implement a corresponding process implemented by the mobile terminal/terminal device in each method according to this embodiment, which is not described herein again for brevity.

Fig. 28 is a schematic structural diagram of a chip of an embodiment of the present application. The chip 1100 shown in fig. 28 includes a processor 1110, and the processor 1110 can call and run a computer program from a memory to implement the method in the embodiment of the present application.

Optionally, as shown in fig. 28, the chip 1100 may further include a memory 1120. From the memory 1120, the processor 1110 can call and run a computer program to implement the method in the embodiment of the present application.

The memory 1120 may be a separate device from the processor 1110, or may be integrated in the processor 1110.

Optionally, the chip 1100 may also include an input interface 1130. The processor 1110 may control the input interface 1130 to communicate with other devices or chips, and in particular, may obtain information or data sent by the other devices or chips.

Optionally, the chip 1100 may further include an output interface 1140. The processor 1110 may control the output interface 1140 to communicate with other devices or chips, and in particular, may output information or data to the other devices or chips.

Optionally, the chip may be applied to the network node in the embodiment of the present application, and the chip may implement a corresponding flow implemented by the SN or the MN in each method in the embodiment of the present application, and for brevity, details are not described here again.

Optionally, the chip may be applied to the mobile terminal/terminal device in the embodiment of the present application, and the chip may implement the corresponding process implemented by the mobile terminal/terminal device in each method in the embodiment of the present application, and for brevity, no further description is given here.

It should be understood that the chips mentioned in the embodiments of the present application may also be referred to as a system-on-chip, a system-on-chip or a system-on-chip, etc.

Fig. 29 is a schematic block diagram of a communication system 1200 provided in an embodiment of the present application. As shown in fig. 29, the communication system 900 includes a terminal device 1210 and a network node 1220.

The terminal device 1210 may be configured to implement corresponding functions implemented by the terminal device in the foregoing method, and the network node 1220 may be configured to implement corresponding functions implemented by the network device, the SN, or the MN in the foregoing method, which is not described herein again for simplicity.

It should be understood that the processor of the embodiments of the present application may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method embodiments may be performed by integrated logic circuits of hardware in a processor or by instructions in the form of software. The Processor may be a general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, or discrete hardware components. The various methods, steps, and logic blocks disclosed in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor.

It will be appreciated that the memory in the embodiments of the subject application can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. The non-volatile Memory may be a Read-Only Memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically Erasable PROM (EEPROM), or a flash Memory. Volatile Memory can be Random Access Memory (RAM), which acts as external cache Memory. By way of example, but not limitation, many forms of RAM are available, such as Static random access memory (Static RAM, SRAM), dynamic Random Access Memory (DRAM), synchronous Dynamic random access memory (Synchronous DRAM, SDRAM), double Data Rate Synchronous Dynamic random access memory (DDR SDRAM), enhanced Synchronous SDRAM (ESDRAM), synchronous link SDRAM (SLDRAM), and Direct Rambus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

It should be understood that the above memories are exemplary but not limiting, for example, the memories in the embodiments of the present application may also be static random access memory (static RAM, SRAM), dynamic random access memory (dynamic RAM, DRAM), synchronous dynamic random access memory (synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous SDRAM (ESDRAM), synchronous Link DRAM (SLDRAM), direct Rambus RAM (DR RAM), and the like. That is, the memory in the embodiments of the present application is intended to comprise, without being limited to, these and any other suitable types of memory.

The embodiment of the application also provides a computer readable storage medium for storing the computer program.

Optionally, the computer-readable storage medium may be applied to the network device in the embodiment of the present application, and the computer program enables the computer to execute the corresponding process implemented by the network device in each method in the embodiment of the present application, which is not described herein again for brevity.

Optionally, the computer-readable storage medium may be applied to the mobile terminal/terminal device in the embodiment of the present application, and the computer program enables the computer to execute the corresponding process implemented by the mobile terminal/terminal device in each method in the embodiment of the present application, which is not described herein again for brevity.

Embodiments of the present application also provide a computer program product, including computer program instructions.

Optionally, the computer program product may be applied to the network device in the embodiment of the present application, and the computer program instructions enable the computer to execute corresponding processes implemented by the network device in the methods in the embodiment of the present application, which are not described herein again for brevity.

Optionally, the computer program product may be applied to the mobile terminal/terminal device in the embodiment of the present application, and the computer program instructions enable the computer to execute the corresponding processes implemented by the mobile terminal/terminal device in the methods in the embodiment of the present application, which are not described herein again for brevity.

The embodiment of the application also provides a computer program.

Optionally, the computer program may be applied to the network device in the embodiment of the present application, and when the computer program runs on a computer, the computer is enabled to execute a corresponding process implemented by the network device in each method in the embodiment of the present application, and for brevity, details are not described here again.

Optionally, the computer program may be applied to the mobile terminal/terminal device in the embodiment of the present application, and when the computer program runs on a computer, the computer is enabled to execute the corresponding process implemented by the mobile terminal/terminal device in each method in the embodiment of the present application, which is not described herein again for brevity.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It can be clearly understood by those skilled in the art that, for convenience and simplicity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may 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 solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

A method of data transmission, comprising:

the terminal equipment receives first configuration information, wherein the first configuration information is used for configuring small data transmission configuration corresponding to a Data Radio Bearer (DRB);

and the terminal equipment transmits the small data according to the first configuration information.
The method of claim 1, wherein the first configuration information is used for configuring a radio data bearer (DRB) capable of being used for small data transmission and/or a DRB incapable of being used for small data transmission.
The method of claim 2, wherein the DRB capable of being used for small data transmission comprises: the termination is carried in the master cell group MCG of the master node MN.
The method of claim 2, wherein the DRB capable of being used for small data transmission comprises: the termination point is carried by the MCG of the MN;

the termination point is carried by the MCG of the secondary node SN.
The method of claim 2, wherein the DRB capable of being used for small data transmission comprises: the termination point is carried by the MCG of the MN;

splitting bearer of the termination point at the MN;

the termination point is carried by the MCG of the SN;

the termination point is at the split bearer of the SN.
The method according to any of claims 2-5, wherein if the DRB capable of being used for small data transmission comprises a split bearer, the first configuration information is further used for configuring a path activated when small data transmission is performed using the split bearer.
The method of claim 6, wherein the path activated when the split bearer is used for small data transmission is an MCG path corresponding to the split bearer.
The method according to any one of claims 1-7, further comprising:

and the terminal equipment generates an SCG key according to the MCG key and the SCG counting value under the condition of meeting a specific condition, wherein the SCG key is used for encrypting and decrypting the small data.
The method according to claim 8, wherein the specific condition comprises at least one of:

a Packet Data Convergence Protocol (PDCP) entity carried by the small data at the SN when the small data arrives at the terminal node;

the small data arrives at a PDCP entity associated with the secondary key;

small uplink data arrive;

there is uplink data arriving;

receiving a paging message of MN, wherein the paging message is used for indicating to receive small data or generating the SCG key;

a paging message for the MN is received.
The method of claim 9, wherein the paging message comprises at least one of: a small data arrival indication for indicating whether small data arrives;

an SCG key derivation indication for indicating whether to generate an SCG key;

list of DRB IDs where small data arrives.
The method according to any of claims 8-10, wherein the SCG count value is configured by a radio resource control, RRC, release message.
The method according to any of claims 8-11, wherein the MCG key is a master key before the terminal device initiates the small data transmission or a master key updated to trigger the small data transmission.
The method according to any of claims 1-12, wherein if there is small downstream data arriving at the first SCG bearer at the SN at the termination point, the method further comprises:

and the terminal equipment receives a first Media Access Control (MAC) Protocol Data Unit (PDU) sent by the MN, wherein the first MAC PDU comprises an RLC PDU or a PDCP PDU corresponding to the downlink small data from the SN.
The method of claim 13, wherein an RLC PDU corresponding to the downlink small data and a message carried by a Common Control Channel (CCCH) are multiplexed in the first MAC PDU; or

And multiplexing the PDCP PDU corresponding to the downlink small data and the message carried by the CCCH in the first MAC PDU.
The method according to claim 13 or 14, wherein the first MAC PDU further comprises first indication information and/or a logical channel identity LCID corresponding to the downlink small data, wherein the first indication information is used to indicate whether the downlink small data is from an SCG bearer.
The method of claim 15, wherein the first indication information is carried in a header of a first MAC service data unit SDU, wherein the LCID corresponding to the small downlink data is carried in the header of the first MAC SDU, wherein the first MAC PDU includes the first MAC SDU, and wherein the first MAC SDU is a MAC SDU used for carrying an RLC PDU or PDCP PDU corresponding to the small downlink data in the first MAC PDU.
The method of claim 16, wherein the first indication information carries a reserved field in the first MAC SDU.
The method of claim 16 or 17, further comprising:

the MCG MAC entity of the terminal equipment determines that the data in the first MAC PDU comes from SCG load according to the first indication information in the first MAC PDU;

and the MCG MAC entity of the terminal equipment sends the first MAC SDU and/or the LCID corresponding to the downlink small data to the SCG MAC entity of the terminal equipment.
The method of claim 18, further comprising:

and the SCG MAC entity of the terminal equipment decodes the first MAC SDU according to the LCID corresponding to the downlink small data and delivers the decoded data to the high layer of the terminal equipment.
The method according to any of claims 1-19, wherein if there is uplink small data arriving at the second SCG bearer with the termination at SN, the method further comprises:

and the MCG MAC entity of the terminal equipment sends a second MAC PDU to the MN, wherein the second MAC PDU comprises an RLC PDU or a PDCP PDU corresponding to the uplink small data.
The method of claim 20, wherein RLC PDU corresponding to the uplink small data and the message carried by CCCH are multiplexed in the second MAC PDU; or

And multiplexing the PDCP PDU corresponding to the uplink small data and the message carried by the CCCH in the second MAC PDU.
The method according to claim 20 or 21, further comprising:

the SCG RLC entity of the terminal equipment generates Radio Link Control (RLC) PDU from the uplink small data and sends the RLC PDU to an MCG MAC entity of the terminal equipment; or

And the SCG PDCP entity of the terminal equipment generates PDCP PDUs from the uplink small data and sends the PDCP PDUs to the MCG MAC entity of the terminal equipment.
The method of claim 22, further comprising:

the SCG RLC entity or the SCG PDCP entity of the terminal equipment sends at least one of the following information to the MCG MAC entity of the terminal equipment:

the LCID corresponding to the uplink small data, the DRB ID carried by the second SGC, and the QoS parameter of the uplink small data.
The method of claim 22 or 23, further comprising:

the MCG MAC entity of the terminal equipment generates the second MAC PDU according to the RLC PDU and the message in the CCCH corresponding to the uplink small data; or

And the MCG MAC entity of the terminal equipment generates the second MAC PDU according to the PDCP PDU corresponding to the uplink small data and the message in the CCCH.
The method according to any of claims 20-24, wherein the second MAC PDU further comprises second indication information and/or an LCID corresponding to the uplink small data, wherein the second indication information is used to indicate that the uplink small data is from an SCG bearer.
The method of claim 25, wherein the second indication information is carried in a header of a second MAC SDU, wherein the LCID corresponding to the uplink small data is carried in the header of the second MAC SDU, and wherein the second MAC PDU comprises the second MAC SDU, and wherein the second MAC SDU is a MAC SDU in the second MAC PDU and used for carrying an RLC PDU or PDCP PDU corresponding to the uplink small data.
A method of data transmission, comprising:

the first node sends first configuration information to the terminal equipment, wherein the first configuration information is used for configuring small data transmission configuration corresponding to the Data Radio Bearer (DRB).
The method of claim 27, wherein the first configuration information is used for configuring a radio data bearer (DRB) capable of being used for small data transmission and/or a DRB incapable of being used for small data transmission.
The method of claim 28, wherein the DRB capable of being used for small data transmission comprises: the termination point is carried in the master cell group MCG of the master node MN.
The method of claim 28, wherein the DRB capable of being used for small data transmission comprises: the termination point is carried by the MCG of the MN;

the termination point is carried at the MCG of the secondary node SN.
The method of claim 28, wherein the DRB capable of being utilized for small data transmission comprises: the termination point is carried by the MCG of the MN;

split bearer of the termination point at the MN;

the termination point is carried by the MCG of the SN;

the termination point is at the split bearer of the SN.
The method according to any of claims 28-31, wherein if the DRB capable of being used for small data transmission comprises a split bearer, the first configuration information is further used for configuring a path activated when small data transmission is performed using the split bearer.
The method of claim 32, wherein the path activated when the split bearer is used for small data transmission is an MCG path corresponding to the split bearer.
A method according to any of claims 27-33, characterised in that the first node is a MN.
The method according to claim 34, wherein the first node is further configured to configure the terminal device with an SCG count value, and the SCG count value is used for the terminal device to generate an SCG key for encryption and decryption of the small data according to an MCG key and the SCG count value.
The method of claim 34 or 35, further comprising:

the MN receives a first message of an SN, wherein the first message is used for triggering the MN to page the terminal equipment, and when downlink small data reach a termination point and are carried by the SN, the SN sends the first message;

and the MN sends a paging message to the terminal equipment according to the first message, wherein the paging message comprises a related indication of small data arrival and/or key generation.
The method of claim 36, wherein the first message comprises at least one of: a small data arrival indication for indicating whether small data arrives;

an SCG key derivation indication for indicating whether to generate an SCG key;

list of DRB IDs where small data arrives.
The method according to claim 36 or 37, wherein the paging message comprises at least one of:

a small data arrival indication for indicating whether small data arrives;

an SCG key derivation indication for indicating whether to generate an SCG key;

list of DRB IDs where small data arrives.
The method according to any of claims 35-38, wherein said SCG count value is configured by means of a radio resource control, RRC, release message.
The method according to any of claims 35-39, wherein the MCG key is a master key before the terminal device initiates the small data transmission or a master key updated to trigger the small data transmission.
The method according to any of claims 27-40, wherein if the downstream small data arrives at the first SCG bearer with the termination at SN, the method further comprises:

and the MN receives the information of the downlink small data sent by the SN.
The method of claim 41, wherein the information of the downlink small data comprises at least one of the following items:

a Radio Link Control (RLC) PDU or a Packet Data Convergence Protocol (PDCP) Protocol Data Unit (PDU) corresponding to the downlink small data;

the logic channel identification LCID to which the downlink small data belongs;

the DRB ID to which the downlink small data belongs;

and the service quality QoS parameter corresponding to the downlink small data.
The method according to claim 41 or 42, wherein the information of the downlink small data is signaled through an Xn interface; or

And the information of the downlink small data is carried by an RRC forwarding message, wherein the RLC PDU or the PDCP PDU is contained in the RRC forwarding message in a container mode.
The method of claim 42, further comprising:

and the MN sends a first Media Access Control (MAC) Protocol Data Unit (PDU) to the terminal equipment, wherein the first MAC PDU comprises an RLC PDU or a PDCP PDU corresponding to the downlink small data from the SN.
The method of claim 44, wherein RLC PDUs corresponding to the downlink small data and messages carried by a Common Control Channel (CCCH) are multiplexed in the first MAC PDU; or

And multiplexing the PDCP PDU corresponding to the downlink small data and the message carried by the CCCH in the first MAC PDU.
The method according to claim 44 or 45, wherein the first MAC PDU further comprises first indication information and/or a logical channel LCID corresponding to the downlink small data, and the first indication information is used for indicating that the downlink small data is from an SCG bearer.
The method of claim 46, wherein the first indication information is carried in a header of the first MAC Service Data Unit (SDU), wherein the LCID corresponding to the small downlink data is carried in the header of the first MAC SDU, wherein the first MAC PDU comprises the first MAC SDU, and wherein the first MAC SDU is the MAC SDU used for carrying the RLC PDU or the PDCP PDU corresponding to the small downlink data in the first MAC PDU.
The method according to any of claims 34-47, wherein if the small upstream data arrives at the second SCG bearer with the termination at SN, the method further comprises:

and the MN receives a second MAC PDU sent by the terminal equipment, wherein the second MAC PDU comprises an RLC PDU or a PDCP PDU corresponding to the uplink small data.
The method of claim 48, wherein RLC PDUs and CCCH-carried messages corresponding to the uplink small data are multiplexed in the second MAC PDU; or

And multiplexing the PDCP PDU corresponding to the uplink small data and the message carried by the CCCH in the second MAC PDU.
The method of claim 49, wherein the second MAC PDU further comprises second indication information and/or a logical channel LCID corresponding to the uplink small data, and wherein the second indication information is used for indicating that the uplink small data is from the second SCG bearer.
The method of claim 50, wherein the second indication information is carried in a header of the second MAC SDU, wherein the LCID corresponding to the uplink small data is carried in the header of the second MAC SDU, wherein the second MAC PDU includes the second MAC SDU, and wherein the second MAC SDU is a MAC SDU used for carrying an RLC PDU or PDCP PDU corresponding to the uplink small data in the second MAC PDU.
The method of claim 51, wherein the second indication information is carried in a reserved field in the second MAC SDU.
The method of claim 51 or 52, further comprising:

the MN determines that the data in the second MAC PDU comes from SCG load according to the second indication information in the second MAC PDU;

and the MN sends the second MAC SDU in the second MAC PDU and/or the LCID corresponding to the uplink small data to an SN.
The method according to claim 53, wherein the second MAC SDU and/or the LCID corresponding to the uplink small data is/are sent to the SN through Xn interface signaling; or, the second MAC SDU and/or the LCID corresponding to the uplink small data is sent to the SN through an RRC forwarding message.
The method of any of claims 27-33, wherein the first node is a SN.
The method of claim 55, further comprising:

and under the condition that the terminal node has downlink data arriving on the bearer of the SN, the SN sends a first message to the MN, wherein the first message is used for triggering the MN to page the terminal equipment.
The method of claim 56, wherein the first message comprises at least one of: a small data arrival indication for indicating whether small data arrives;

an SCG key derivation indication for indicating whether to generate an SCG key;

list of DRB IDs where small data arrives.
The method according to any of claims 27-33, wherein if the downstream small data arrives at the first SCG bearer at the SN at the termination point, the method further comprises:

and the SN sends the information of the downlink small data to the MN.
The method of claim 58, wherein the information of the downlink small data comprises at least one of:

a radio link control RLC PDU or a PDCP PDU corresponding to the downlink small data;

the logic channel identification LCID to which the downlink small data belongs;

a DRB ID to which the downlink small data belongs;

and the QoS parameter corresponds to the downlink small data.
The method according to claim 58 or 59, wherein the information of the downlink small data is signaled through an Xn interface; or

And the information of the downlink small data is carried by an RRC forwarding message, wherein the RLC PDU or the PDCP PDU is contained in the RRC forwarding message in a container mode.
The method according to any of claims 27-33, wherein if an upstream small data arrives at a second SCG bearer at a termination point of the SN, the method further comprises:

and the SN receives the information of the uplink small data from the terminal equipment, which is sent by the MN.
The method of claim 61, wherein the information of the uplink small data is signaled through an Xn interface; or, the information of the uplink small data is sent through an RRC forwarding message.
The method according to claim 61 or 62, wherein the information of uplink small data comprises at least one of the following:

a second MAC SDU corresponding to the uplink small data, where the second MAC SDU is used to carry an RLC PDU or PDCP PDU corresponding to the uplink small data;

and the Logical Channel Identifier (LCID) to which the uplink small data belongs.
The method of claim 63, further comprising: and the SN decodes the second MAC SDU according to the LCID to which the uplink small data belongs, and submits a decoding result to a core network.
A terminal device, comprising:

a communication unit, configured to receive first configuration information, where the first configuration information is used to configure a small data transmission configuration corresponding to a data radio bearer DRB;

and transmitting small data according to the first configuration information.
The terminal device of claim 65, wherein the first configuration information is used to configure a radio data bearer (DRB) capable of being used for small data transmission and/or a DRB incapable of being used for small data transmission.
The terminal device of claim 66, wherein the DRBs that can be used for small data transmission comprise: the termination is carried in the master cell group MCG of the master node MN.
The terminal device of claim 66, wherein the DRBs enabled for small data transmission comprise: the termination point is carried by the MCG of the MN;

the termination point is carried by the MCG of the secondary node SN.
The terminal device of claim 66, wherein the DRBs enabled for small data transmission comprise: the termination point is carried by the MCG of the MN;

split bearer of the termination point at the MN;

the termination point is carried by the MCG of the SN;

the termination point is at the split bearer of the SN.
The terminal device of any one of claims 66-69, wherein if the DRBs that can be used for small data transmission comprise split bearers, the first configuration information is further used to configure paths that are activated when small data transmission is performed using the split bearers.
The terminal device of claim 70, wherein the path activated when the split bearer is used for small data transmission is an MCG path corresponding to the split bearer.
The terminal device according to any of claims 65-71, wherein the terminal device further comprises:

and the processing unit is used for generating an SCG key according to the MCG key and the SCG counting value under the condition that a specific condition is met, wherein the SCG key is used for encryption and decryption of the small data.
The terminal device of claim 72, wherein the specific condition comprises at least one of:

the small data arrives at a packet data convergence protocol PDCP entity carried by the termination point at the SN;

the small data arrives at a PDCP entity associated with the secondary key;

small uplink data arrive;

there is uplink data arriving;

receiving a paging message of MN, wherein the paging message is used for indicating to receive small data or generating the SCG key;

a paging message for the MN is received.
The terminal device of claim 73, wherein the paging message comprises at least one of: a small data arrival indication for indicating whether small data arrives;

an SCG key derivation indication for indicating whether to generate an SCG key;

list of DRB IDs where small data arrives.
The terminal device of any of claims 72-74, wherein the SCG count value is configured by a radio resource control, RRC, release message.
A terminal device according to any one of claims 72-75, wherein the MCG key is a master key before the terminal device initiates a small data transmission or a master key that is updated to trigger a small data transmission.
The terminal device according to any of claims 65-76, wherein if there is a first SCG bearer with a SN downstream small data arriving at the termination point, the communication unit is further configured to:

and receiving a first Media Access Control (MAC) Protocol Data Unit (PDU) sent by an MN, wherein the first MAC PDU comprises an RLC PDU or a PDCP PDU corresponding to the downlink small data from the SN.
The terminal device of claim 77, wherein an RLC PDU corresponding to the downlink small data and a message carried by a Common Control Channel (CCCH) are multiplexed in the first MAC PDU; or

And multiplexing the PDCP PDU corresponding to the downlink small data and the message carried by the CCCH in the first MAC PDU.
The terminal device of claim 77 or 78, wherein the first MAC PDU further comprises first indication information and/or a Logical Channel Identity (LCID) corresponding to the downlink small data, and wherein the first indication information is used for indicating whether the downlink small data is from an SCG bearer.
The terminal device of claim 79, wherein the first indication information is carried in a header of a first MAC Service Data Unit (SDU), wherein the LCID corresponding to the small downlink data is carried in the header of the first MAC SDU, and wherein the first MAC PDU includes the first MAC SDU, and wherein the first MAC SDU is a MAC SDU in the first MAC PDU for carrying an RLC PDU or PDCP PDU corresponding to the small downlink data.
The terminal device of claim 80, wherein the first indication information carries a reserved field in the first MAC SDU.
The terminal device of claim 80 or 81, wherein the terminal device further comprises:

the processing unit is used for determining that the data in the first MAC PDU is from an SCG bearer according to the first indication information in the first MAC PDU at an MCG MAC layer;

the communication unit is further configured to: and sending the LCID corresponding to the first MAC SDU and/or the downlink small data to an SCG MAC layer in the MCG MAC layer.
The terminal device of claim 82, wherein the processing unit is further configured to:

and decoding the first MAC SDU on the SCG MAC layer according to the LCID corresponding to the downlink small data, and delivering the decoded data to a high layer of the terminal equipment.
The terminal device according to any of claims 65-83, wherein if there is uplink small data arriving at the second SCG bearer at the SN at the termination point, the communication unit is further configured to:

and sending a second MAC PDU to the MN at the MCG MAC layer, wherein the second MAC PDU comprises an RLC PDU or a PDCP PDU corresponding to the uplink small data.
The terminal device of claim 84, wherein RLC PDUs and CCCH-carried messages corresponding to the uplink small data are multiplexed in the second MAC PDU; or

And multiplexing the PDCP PDU corresponding to the uplink small data and the message carried by the CCCH in the second MAC PDU.
The terminal device according to claim 84 or 85, wherein the terminal device further comprises:

a processing unit, configured to generate a radio link control RLC PDU from the small uplink data on an SCG RLC layer, and send the RLC PDU to an MCG MAC entity of the terminal device; or generating PDCP PDU by the uplink small data at the SCG PDCP layer and sending the PDCP PDU to the MCG MAC entity of the terminal equipment.
The terminal device of claim 86, wherein the processing unit is further configured to:

transmitting, at the SCG RLC layer or the SCG PDCP layer, at least one of the following information to the MCG MAC layer:

the LCID corresponding to the uplink small data, the DRB ID carried by the second SGC, and the QoS parameter of the uplink small data.
The terminal device according to claim 86 or 87, wherein the processing unit is further configured to:

generating the second MAC PDU according to the RLC PDU corresponding to the uplink small data and the message in the CCCH on the MCG MAC layer; or

And generating the second MAC PDU according to the PDCP PDU corresponding to the uplink small data and the message in the CCCH on the MCG MAC layer.
The terminal device according to any of claims 84-88, wherein the second MAC PDU further comprises second indication information and/or an LCID corresponding to the uplink small data, wherein the second indication information is used to indicate that the uplink small data is from an SCG bearer.
The terminal device of claim 89, wherein the second indication information is carried in a header of a second MAC SDU, wherein the LCID corresponding to the uplink small data is carried in the header of the second MAC SDU, and wherein the second MAC PDU includes the second MAC SDU, and wherein the second MAC SDU is a MAC SDU used for carrying an RLC PDU or PDCP PDU corresponding to the uplink small data in the second MAC PDU.
A network node, comprising:

a communication unit, configured to send first configuration information to a terminal device, where the first configuration information is used to configure small data transmission configuration corresponding to a data radio bearer DRB.
The network node according to claim 91, wherein the first configuration information is used to configure a radio data bearer (DRB) that can be used for small data transmission and/or a DRB that cannot be used for small data transmission.
The network node of claim 92, wherein the DRBs capable of being utilized for small data transmission comprise: the termination is carried in the master cell group MCG of the master node MN.
The network node of claim 92, wherein the DRBs capable of being utilized for small data transmission comprise: the termination point is carried by the MCG of the MN;

the termination point is carried by the MCG of the secondary node SN.
The network node of claim 92, wherein the DRBs capable of being utilized for small data transmission comprise: the termination point is carried by the MCG of the MN;

splitting bearer of the termination point at the MN;

the termination point is carried by the MCG of the SN;

the termination point is at the split bearer of the SN.
The network node according to any of claims 92-95, wherein if the DRBs available for small data transmission comprise split bearers, the first configuration information is further used to configure paths activated when small data transmission is performed using the split bearers.
The network node of claim 96, wherein the path activated when the split bearer is used for small data transmission is an MCG path corresponding to the split bearer.
The network node according to any of claims 91-97, wherein the first node is a MN.
The network node according to claim 98, wherein said first node is further configured to configure the terminal device with SCG count values, said SCG count values being used by the terminal device to generate SCG keys for encryption and decryption of the small data according to MCG keys and said SCG count values.
The network node of claim 98 or 99, wherein the communication unit is further configured to:

receiving a first message of an SN, wherein the first message is used for triggering the MN to page the terminal equipment, and when downlink small data arrives at a terminal node and is carried by the SN, the SN sends the first message;

and sending a paging message to the terminal equipment according to the first message, wherein the paging message comprises related indications of small data arrival and/or key generation.
The network node of claim 100, wherein the first message comprises at least one of: a small data arrival indication for indicating whether small data arrives;

an SCG key derivation indication for indicating whether to generate an SCG key;

list of DRB IDs where small data arrives.
The network node according to claim 100 or 101, wherein the paging message comprises at least one of:

a small data arrival indication for indicating whether small data arrives;

an SCG key derivation indication for indicating whether to generate an SCG key;

list of DRB IDs where small data arrives.
The network node according to any of claims 98-102, wherein the SCG count value is configured by a radio resource control, RRC, release message.
The network node according to any of claims 99-103, wherein the MCG key is a master key before the terminal device initiates the small data transmission or a master key that is updated to trigger the small data transmission.
The network node according to any of claims 91-104, wherein if the small downstream data arrives at the first SCG bearer at the SN at the termination, the communication unit is further configured to:

and receiving the information of the downlink small data sent by the SN.
The network node of claim 105, wherein the information of the downlink small data comprises at least one of:

a Radio Link Control (RLC) PDU or a Packet Data Convergence Protocol (PDCP) Protocol Data Unit (PDU) corresponding to the downlink small data;

the logic channel identification LCID to which the downlink small data belongs;

the DRB ID to which the downlink small data belongs;

and the QoS parameter corresponds to the downlink small data.
The network node according to claim 105 or 106, wherein the information of the downlink small data is signaled through an Xn interface; or

And the information of the downlink small data is carried by an RRC forwarding message, wherein the RLC PDU or the PDCP PDU is contained in the RRC forwarding message in a container mode.
The network node of claim 106, wherein the communication unit is further configured to:

and sending a first Media Access Control (MAC) Protocol Data Unit (PDU) to the terminal equipment, wherein the first MAC PDU comprises an RLC PDU or a PDCP PDU corresponding to the downlink small data from the SN.
The network node of claim 108, wherein an RLC PDU corresponding to the downlink small data and a message carried on a common control channel CCCH are multiplexed in the first MAC PDU; or

And multiplexing the PDCP PDU corresponding to the downlink small data and the message carried by the CCCH in the first MAC PDU.
The network node according to claim 108 or 109, wherein the first MAC PDU further comprises first indication information and/or a logical channel LCID corresponding to the downlink small data, and wherein the first indication information is used to indicate that the downlink small data is from an SCG bearer.
The network node of claim 110, wherein the first indication information is carried in a header of the first MAC service data unit SDU, wherein the LCID corresponding to the small downlink data is carried in the header of the first MAC SDU, wherein the first MAC PDU includes the first MAC SDU, and wherein the first MAC SDU is a MAC SDU used for carrying an RLC PDU or a PDCP PDU corresponding to the small downlink data in the first MAC PDU.
The network node according to any of claims 108-111, wherein if the small upstream data arrives at the second SCG bearer at the SN at the termination point, the communication unit is further configured to:

and receiving a second MAC PDU sent by the terminal equipment, wherein the second MAC PDU comprises an RLC PDU or a PDCP PDU corresponding to the uplink small data.
The network node of claim 112, wherein RLC PDUs corresponding to uplink small data and CCCH-carried messages are multiplexed in the second MAC PDU; or the PDCP PDU corresponding to the uplink small data and the message carried by the CCCH are multiplexed in the second MAC PDU.
The network node of claim 113, wherein the second MAC PDU further comprises second indication information and/or a logical channel LCID corresponding to the uplink small data, and wherein the second indication information is used to indicate that the uplink small data is from the second SCG bearer.
The network node of claim 114, wherein the second indication information is carried in a header of the second MAC SDU, wherein the LCID corresponding to the uplink small data is carried in the header of the second MAC SDU, wherein the second MAC PDU comprises the second MAC SDU, and wherein the second MAC SDU is a MAC SDU in the second MAC PDU and used for carrying an RLC PDU or PDCP PDU corresponding to the uplink small data.
The network node of claim 115, wherein the second indication information carries a reserved field in the second MAC SDU.
The network node according to claim 115 or 116, wherein the network node further comprises:

a processing unit, configured to determine, according to the second indication information in the second MAC PDU, that data in the second MAC PDU is from an SCG bearer;

the communication unit is further configured to: and sending the second MAC SDU and/or the LCID corresponding to the uplink small data in the second MAC PDU to an SN.
The network node according to claim 27, wherein the second MAC SDU and/or the LCID corresponding to the uplink small data is sent to the SN through Xn interface signaling; or, the second MAC SDU and/or the LCID corresponding to the uplink small data is sent to the SN through an RRC forwarding message.
The network node according to any of claims 91-97, wherein the first node is a SN.
The network node of claim 119, wherein the communication unit is further configured to:

and under the condition that the terminal node has downlink data arriving on the bearer of the SN, sending a first message to the MN, wherein the first message is used for triggering the MN to page the terminal equipment.
The network node of claim 120, wherein the first message comprises at least one of: a small data arrival indication for indicating whether small data arrives;

an SCG key derivation indication for indicating whether to generate an SCG key;

list of DRB IDs where small data arrives.
The network node according to any of claims 91-97, wherein if a small downstream data arrives at a termination point at a first SCG bearer of the SN, the communication unit is further configured to:

and sending the information of the downlink small data to the MN.
The network node of claim 122, wherein the information of the downlink small data comprises at least one of:

a radio link control RLC PDU or a PDCP PDU corresponding to the downlink small data;

the logic channel identification LCID to which the downlink small data belongs;

a DRB ID to which the downlink small data belongs;

and the service quality QoS parameter corresponding to the downlink small data.
The network node according to claim 122 or 123, wherein the information of the downlink small data is signaled through an Xn interface; or

The information of the downlink small data is carried by an RRC forwarding message, wherein the RLC PDU or the PDCP PDU is contained in the RRC forwarding message in a container mode.
The network node of any of claims 91-97, wherein if an upstream small data arrival termination is on a second SCG bearer of the SN, the communication unit is further configured to:

and receiving the information of the uplink small data from the terminal equipment, which is sent by the MN.
The network node according to claim 125, wherein the information of the uplink small data is signaled through an Xn interface; or, the information of the uplink small data is sent through an RRC forwarding message.
The network node according to claim 125 or 126, wherein the information of the uplink small data comprises at least one of:

a second MAC SDU corresponding to the uplink small data, where the second MAC SDU is used to carry an RLC PDU or PDCP PDU corresponding to the uplink small data;

and the logical channel identifier LCID to which the uplink small data belongs.
The network node of claim 127, wherein the network node further comprises:

a processing unit, configured to decode the second MAC SDU according to the LCID to which the uplink small data belongs;

the communication unit is further configured to: and submitting the decoding result to the core network.
A terminal device, comprising: a processor and a memory for storing a computer program, the processor being adapted to invoke and execute the computer program stored in the memory, performing the method of any of claims 1 to 26.
A chip, comprising: a processor for calling and running a computer program from a memory so that a device on which the chip is installed performs the method of any one of claims 1 to 26.
A computer-readable storage medium for storing a computer program which causes a computer to perform the method of any one of claims 1 to 26.
A computer program product comprising computer program instructions for causing a computer to perform the method of any one of claims 1 to 26.
A computer program, characterized in that the computer program causes a computer to perform the method according to any of claims 1-26.
A network device, comprising: a processor and a memory for storing a computer program, the processor for invoking and executing the computer program stored in the memory, performing the method of any one of claims 27 to 64.
A chip, comprising: a processor for calling and running a computer program from a memory so that a device on which the chip is installed performs the method of any of claims 27 to 64.
A computer-readable storage medium for storing a computer program which causes a computer to perform the method of any one of claims 27 to 64.
A computer program product comprising computer program instructions for causing a computer to perform the method of any one of claims 27 to 64.
A computer program, characterized in that the computer program causes a computer to execute the method of any of claims 27-64.