CN117156500B

CN117156500B - Data transmission method, network device and computer readable storage medium

Info

Publication number: CN117156500B
Application number: CN202210576117.9A
Authority: CN
Inventors: 张戬
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2022-05-24
Filing date: 2022-05-24
Publication date: 2025-02-11
Anticipated expiration: 2042-05-24
Also published as: WO2023226647A1; CN117156500A

Abstract

The present application relates to the field of communication technology, and aims to solve the problem that the frequent transmission of small data packets leads to large signaling overhead of network devices, and provides a data transmission method, a network device and a computer-readable storage medium. Among them, the data transmission method is applied to the network device, and when the network device is an anchor base station, the data transmission method includes: obtaining downlink data or signaling for the user device from the core network. Among them, the user equipment is in an RRC inactive state, and the downlink data or signaling carries first configuration information, and the first configuration information is used to determine whether to perform user equipment context migration. Determine whether to perform user equipment context migration according to the first configuration information. If it is determined to perform user equipment context migration, the user equipment context is migrated to the serving base station, and downlink data or signaling is sent to the serving base station.

Description

Data transmission method, network device and computer readable storage medium

Technical Field

The present application relates to the field of communications technologies, and in particular, to a data transmission method, a network device, and a computer readable storage medium.

Background

In a fifth Generation (5 th-Generation, 5G) New air interface (NR) network, a state of Radio resource control (Radio Resource Control, RRC) is introduced, namely, an RRC Inactive state, to improve the efficiency of frequent transmission of small packets. When the network device sends an RRC release (RRC RELEASE) message carrying a suspended (Suspend) configuration to a User Equipment (UE) in an RRC Connected (Connected) state, the UE will be instructed to enter an RRC inactive state. When the UE is in the RRC inactive state, the Context of the UE (UE Context) is suspended on both the UE side and the network device side. As such, when the UE needs to send data/signaling, an RRC resume request (RRC Resume Request) message may be sent to the network device first, so that the UE switches from the RRC inactive state to the RRC connected state, and then the UE may send data/signaling to the network device. If the data/signaling transmission is frequent, the ue will frequently perform state switching, resulting in excessive signaling overhead.

Disclosure of Invention

The embodiment of the application provides a data transmission method, network equipment and a computer readable storage medium, which are used for reducing signaling overhead caused by state switching of user equipment and improving data transmission efficiency.

The first aspect of the present application provides a data transmission method applied to an anchor base station, where the data transmission method includes acquiring downlink data or signaling for user equipment from a core network. The user equipment is in a radio resource control RRC inactive state, and downlink data or signaling carries first configuration information, wherein the first configuration information is used for determining whether to perform user equipment context migration. And determining whether to perform context migration of the user equipment according to the first configuration information. And if the user equipment context migration is determined, migrating the user equipment context to the service base station and sending downlink data or signaling to the service base station.

By adopting the technical scheme, when the anchor base station receives the downlink data or the signaling from the core network, whether the user equipment context migration is performed or not is determined according to the first configuration information carried by the downlink data or the signaling, so that signaling resources can be saved, and the waste of the signaling resources caused by performing the user equipment context migration under the unnecessary condition is avoided. When determining to migrate the context of the user equipment, the anchor base station migrates the context of the user equipment and sends downlink data or signaling to the service base station, so that the downlink data or signaling can be transmitted during the period that the user equipment is in the RRC inactive state without switching the user equipment from the RRC inactive state to the RRC connected state, thereby reducing signaling overhead caused by state switching of the user equipment, reducing service delay and improving data transmission efficiency.

In one embodiment, the sending of the downlink data or signaling to the serving base station includes sending the downlink data or signaling to the serving base station in a mobile terminated small data packet transfer MT-SDT mode.

By adopting the technical scheme, when the small data packet is frequently received from the core network, the anchor base station transmits downlink data or signaling in an MT-SDT mode, and can directly transmit the small data packet during the time when the user equipment is in the RRC inactive state without frequently switching the RRC state of the user equipment, so that signaling overhead caused by state switching of the user equipment can be reduced, service delay is reduced, and data transmission efficiency is improved.

In another embodiment, the first configuration information includes at least one of assistance information, radio bearers, and packet sizes. The auxiliary information is used for carrying out small data packet transmission SDT indication on data to be transmitted, and comprises at least one of subscription data, capability, data transmission statistical information, data or signaling service characteristics and first indication information related to SDT of user equipment. The first indication information is used for indicating triggering mobile termination small data packet transmission.

By adopting the technical scheme, before transmitting downlink data or signaling, the anchor base station determines whether to perform user equipment context migration or not according to at least one of auxiliary information, radio bearer and data packet size, so that signaling resources can be saved, and the signaling resources waste caused by performing user equipment context migration under the unnecessary condition is avoided.

In another embodiment, the data transmission method further comprises, prior to migrating the user equipment context to the serving base station, receiving a retrieve user equipment context request message from the serving base station, the retrieve user equipment context request message for requesting the user equipment context. Migrating the user equipment context to the serving base station includes sending a retrieve user equipment context response message to the serving base station, the retrieve user equipment context response message carrying the user equipment context. The data transmission method further includes, after migrating the user equipment context to the serving base station, receiving a user equipment context release message from the serving base station and releasing the stored user equipment context, the user equipment context release message indicating the release of the stored user equipment context.

By adopting the technical scheme, when the anchor base station determines to perform the context migration of the user equipment, the context migration of the user equipment is passively triggered, namely, after receiving the request message for retrieving the context of the user equipment from the service base station, the anchor base station sends the context of the user equipment to the service base station.

In another embodiment, the retrieving user equipment context response message also carries at least one of packet size, frequency and side information that allows transmission, the side information being used to indicate SDT of data to be transmitted.

In another embodiment, the data transmission method further comprises sending a paging message to the serving base station, the paging message carrying the first indication information, before migrating the user equipment context to the serving base station. The first indication information is used for indicating triggering MT-SDT. The data transmission method further includes receiving a user equipment context release message from the serving base station after migrating the user equipment context to the serving base station and releasing the stored user equipment context. Wherein the user equipment context release message is used to indicate the release of the stored user equipment context.

By adopting the technical scheme, when the anchor base station determines to perform the context migration of the user equipment, the context migration of the user equipment is actively triggered, namely, the user equipment context is directly sent to the service base station.

In another embodiment, the data transmission method further comprises receiving a retrieve user equipment context request message from the serving base station and sending a retrieve user equipment context failure message and downlink data or signaling to the serving base station if it is determined that no user equipment context migration is performed. Wherein, the retrieving user equipment context request message is used for requesting the user equipment context, and the retrieving user equipment context failure message is used for notifying the service base station that all the user equipment contexts are not acquired.

By adopting the technical scheme, when the fact that the user equipment context migration is not performed is determined, the anchor base station sends a message of failure in retrieving the user equipment context to the service base station so as to inform that all the user equipment contexts are not migrated, and therefore downlink data or signaling can be rapidly transmitted.

In another embodiment, the data transmission method further includes sending a user equipment part context setting request message to the serving base station if it is determined that the user equipment context migration is not performed, where the user equipment part context setting request message carries second configuration information, and the second configuration information is used for configuring a data transmission mode in a scenario where the user equipment context migration is not performed. And sending part of the user equipment context and downlink data or signaling to the service base station according to the second configuration information.

By adopting the technical scheme, when the fact that the context migration is not performed is determined, the anchor base station sends a user equipment part context setting request message to the service base station, and sends part of user equipment contexts according to second configuration information carried by the user equipment part context setting request message so as to meet the data transmission requirement of the network.

In another embodiment, the data transfer means comprises MT-SDT or SDT.

In another embodiment, the second configuration information includes a paging message, a portion of a user equipment context, and a protocol data unit of a packet data convergence protocol layer. The paging message carries second indication information, and the second indication information is used for indicating that the MT-SDT is not triggered. The protocol data units of the packet data convergence protocol layer are used for storing downlink data or signaling.

By adopting the technical scheme, the anchor base station transmits partial user equipment context and protocol data units of the packet data convergence protocol layer together when transmitting the paging message, thereby not only meeting the data transmission requirement of the network, but also reducing the signaling overhead.

The second aspect of the present application provides a data transmission method applied to a serving base station, where the data transmission method includes acquiring downlink data or signaling for a user equipment from an anchor base station. The user equipment is in a radio resource control RRC inactive state, and downlink data or signaling carries first configuration information, wherein the first configuration information is used for determining whether to perform user equipment context migration. If the anchor base station determines to migrate the user equipment context, the anchor base station receives the user equipment context from the anchor base station and sends downlink data or signaling to the user equipment.

By adopting the technical scheme, when the service base station receives the downlink data or the signaling from the anchor base station, whether the anchor base station performs the user equipment context migration or not is determined according to the first configuration information carried by the downlink data or the signaling, so that signaling resources can be saved, and the waste of the signaling resources caused by performing the user equipment context migration under the unnecessary condition is avoided. When the anchor base station determines to migrate the context of the user equipment, the anchor base station receives the context of the user equipment and downlink data or signaling from the anchor base station and sends the downlink data or signaling to the user equipment, so that the downlink data or signaling can be transmitted during the time when the user equipment is in the RRC inactive state without switching the user equipment from the RRC inactive state to the RRC connected state, thereby reducing signaling overhead caused by state switching of the user equipment, reducing service delay and improving data transmission efficiency.

In one embodiment, after sending the downlink data or signaling to the user equipment, the data transmission method further includes sending an RRC release message to the user equipment, where the RRC release message is used to instruct the user equipment to enter an RRC inactive state or an idle state. Or sending an RRC recovery message to the user equipment, wherein the RRC recovery message is used for indicating the user equipment to enter an RRC connection state.

By adopting the technical scheme, when the downlink data or signaling transmission is completed, the service base station can send the RRC release message or the RRC recovery message to the user equipment according to the actual demand, thereby indicating the user equipment to enter a corresponding state.

It will be appreciated that the data transmission method provided in the second aspect of the present application is applied to a serving base station, and is substantially the same as the data transmission method provided in the first aspect of the present application.

A third aspect of the present application provides a network device comprising a memory and a processor invoking a computer program or code stored in the memory to perform a data transmission method according to an embodiment of the present application.

It will be appreciated that the network device may be an anchor base station or a serving base station. The data transmission method provided in the first aspect of the present application may be performed when the network device is an anchor base station. The data transmission method provided in the second aspect of the present application may be performed when the network device is a serving base station.

A fourth aspect of the present application provides a computer-readable storage medium storing a computer program or instructions which, when executed by a processor, implement a data transmission method according to an embodiment of the present application.

It will be appreciated that, in particular embodiments and technical effects of the network device provided in the third aspect of the present application and the computer readable storage medium provided in the fourth aspect of the present application, reference may be made to the data transmission method provided in the first aspect and the second aspect of the present application, which are not described herein.

Drawings

Fig. 1 is a schematic diagram of a 5G network architecture.

Fig. 2 is a schematic diagram of an information interaction scenario in which a ue transitions from an RRC inactive state to an RRC connected state in an example.

Fig. 3 is a schematic diagram of an information interaction scenario in which a user equipment transitions from an RRC inactive state to an RRC connected state in another example.

Fig. 4a is a schematic diagram of an information interaction scenario of a data transmission method in a scenario in which an anchor base station performs user equipment context migration.

Fig. 4b is a schematic diagram of an information interaction scenario of a data transmission method in a scenario in which an anchor base station does not perform user equipment context migration.

Fig. 5 is a schematic diagram of an information interaction scenario of another data transmission method in a scenario in which an anchor base station performs user equipment context migration.

Fig. 6 is a schematic diagram of an information interaction scenario of another data transmission method in a scenario in which an anchor base station performs user equipment context migration.

Fig. 7 is a schematic diagram of an information interaction scenario of another data transmission method in a scenario in which an anchor base station performs user equipment context migration.

Fig. 8 is a schematic diagram of an information interaction scenario of another data transmission method in a scenario in which an anchor base station performs user equipment context migration.

Fig. 9 is a schematic diagram of an information interaction scenario of another data transmission method in a scenario in which an anchor base station performs user equipment context migration.

Fig. 10 is a schematic diagram of an information interaction scenario of another data transmission method in a scenario in which an anchor base station performs user equipment context migration.

Fig. 11 is a schematic diagram of an information interaction scenario of another data transmission method in a scenario in which an anchor base station does not perform user equipment context migration.

Fig. 12 is a schematic diagram of an information interaction scenario of another data transmission method in a scenario in which an anchor base station does not perform user equipment context migration.

Fig. 13 is a schematic diagram of an information interaction scenario of another data transmission method in a scenario in which an anchor base station does not perform user equipment context migration.

Fig. 14 is a schematic structural diagram of a network device according to an embodiment of the present application.

Fig. 15 is a schematic structural diagram of a network device according to another embodiment of the present application.

Fig. 16 is a schematic structural diagram of a user equipment according to an embodiment of the present application.

Detailed Description

It should be noted that, in the embodiments of the present application, "at least one" means one or more, and "a plurality" means two or more. "and/or" describes an association relationship of associated objects, meaning that there may be three relationships, e.g., A and/or B may mean that A alone exists, while A and B together exist, and B alone exists, where A, B may be singular or plural. The terms "first," "second," "third," "fourth" and the like in the description and in the claims and drawings, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order.

It should be further noted that, in the method disclosed in the embodiment of the present application or the method shown in the flowchart, one or more steps for implementing the method are included, and the execution order of the steps may be interchanged with each other, where some steps may be deleted without departing from the scope of the claims.

Some terms in the embodiments of the present application are explained below to facilitate understanding by those skilled in the art.

1 User Equipment (User Equipment, UE)

The user equipment, also referred to as Mobile Terminal (ms), mobile user equipment, etc., may communicate with one or more core networks via a radio access network (Radio Access Network, RAN).

2, Network device

A network device refers to a device deployed in a radio access network to provide wireless communication functionality for user equipment. The network devices may include base stations, which may include macro base stations, micro base stations, relay stations, access point base station controllers or transmission and reception points (Transmission Reception Point, TRP), and the like. The specific names of base stations are different in different networks, for example, in a long term evolution (Long Term Evolution, LTE) network, called Evolved NodeB (eNB), and in a subsequent Evolved system, also called New Radio NodeB (gNB). Herein, the base station may act as a Serving base station (Serving gNB) and/or an Anchor base station (Anchor gNB). The service base station refers to a base station currently serving the user equipment, and the anchor base station refers to a base station serving the user equipment last time.

Notification area (RAN based Notification Area, RNA) based on radio access network (Radio Access Network, RAN)

The radio access network based notification area, also referred to as radio access network notification area (RNA), may comprise one or more cells. If the RNA comprises a plurality of cells, the plurality of cells may be cells under the control of one or more base stations (e.g., eNB and/or gNB).

Core Network (CN)

The user equipment performs data transmission with the core network via the network equipment, for example with an access and mobility management function (ACCESS AND Mobility Management Function, AMF) or a user plane function (User Plane Function, UPF) of the core network.

5 Radio resource control (Radio Resource Control, RRC) state

Fig. 1 illustrates an interaction relationship between network functions and entities and corresponding interfaces, taking a network service architecture of the 5G system as an example.

Referring to fig. 1, in a 5G network architecture (service-based architecture, SBA), network functions and entities mainly include a User Equipment (UE), AN Access Network (AN) or a Radio Access Network (RAN), a User Plane Function (UPF), a Data Network (DN), AN Access Management Function (AMF), a session management function (session management function, SMF), AN authentication service function (authentication server function, AUSF), a policy control function (policy control function, PCF), AN application function (application function, AF), a network slice selection function (network slice selection function, NSSF), a unified data management (unified DATA MANAGEMENT, UDM), a network opening function (network exposure function, NEF), and a network storage function (network repository function, NRF).

The network functions can be implemented as a network element running on proprietary hardware, or as software instances running on proprietary hardware, or as virtual functions instantiated on a suitable platform, such as on a cloud-based device.

The main functions of some network elements are described in detail below.

AN/RAN various forms of network equipment may be included in the AN/RAN. The AN/RAN is mainly responsible for radio resource management, uplink and downlink data classification, quality of service (quality of service, qoS) management, data compression and encryption, signaling processing with a control plane network element or data forwarding with a user plane function network element, and the like. The embodiment of the application does not limit the specific form and structure of the AN/RAN.

UPF is mainly responsible for packet routing and forwarding, qoS processing of user plane data or statistics of charging information, etc. The transmission resources and scheduling functions in the UPF that serve the UE are managed and controlled by the SMF.

DN is the network used to transmit the data. For example, the DN may be an operator service network, an internet access or third party service network, or the like.

In the 5G network shown in fig. 1, there are three RRC states of the user equipment, RRC connected state, RRC idle state, and RRC inactive state. The three RRC states may transition between each other, and transitions between the three RRC states may also be referred to herein as "state handoffs" or "state transitions".

The RRC Connected (Connected) state may also be simply referred to as a Connected state. Herein, "connected state" and "RRC connected state" are the same concept. When the user equipment is in a connected state, the user equipment establishes RRC connection with the network, and can perform data transmission.

The RRC Idle state may also be referred to simply as Idle state. Herein, "idle state" and "RRC idle state" are the same concept. When the user equipment is in an idle state, the user equipment does not establish an RRC connection with the network, and the base station does not store a Context (Context) of the user equipment. If the user equipment needs to enter the RRC connected state from the RRC idle state, an RRC connection establishment procedure needs to be initiated.

The RRC Inactive (Inactive) state may also be simply referred to as Inactive state. Herein, "inactive state" and "RRC inactive state" are the same concept. When the user equipment is in an inactive state, the user equipment enters an RRC connection state at the anchor base station before, and then the anchor base station releases the RRC connection, but the anchor base station saves the context of the user equipment. If the user equipment needs to enter the RRC connected state again from the RRC inactive state, an RRC connection recovery procedure, otherwise referred to as an RRC connection re-establishment procedure, needs to be initiated at the serving base station. Because the user equipment may be in motion, the serving base station may be the same base station as the anchor base station or may be a different base station.

6 Small data packet Transmission ((SMALL DATA Transmission, SDT))

In the embodiment of the application, the data packet with the data volume smaller than the preset data volume threshold value can be called a small data packet. In a conventional communication network, a ue in an idle state or an inactive state needs to perform transmission of multiple control signaling with a base station to enter a connection state, and then perform data or signaling transmission with the base station. In a Communication network such as Machine Type Communication (MTC), the ue frequently sends some small data packets to the base station, which may cause the ue in an idle state or an inactive state to frequently switch to a connected state, resulting in a large amount of signaling overhead and increased power consumption of the base station.

For this situation, there is currently a way in which the ue can perform data Transmission without entering a connection state, that is, a small data packet Transmission (SDT) way. The small data packet transmission mode refers to that after the user equipment determines that the data packet to be transmitted is a small data packet, the small data packet is integrated in some control signaling, and then the small data packet is transmitted to the base station through the control signaling. Or the user equipment transmits the small data packet to the base station using its stored context. The small data packet Transmission mode may include a data early Transmission (EARLY DATA Transmission, EDT) mode, a two-step random access or Pre-uplink resource allocation (Pre-Configured Uplink Resource, PUR) mode, etc.

7 Mobile termination (Mobile Terminated, MT)

Mobile termination, also known as mobile called, involves mobile messages routed from a core network device (e.g., AMF) or a network device (e.g., base station) and sent to a user equipment. Mobile termination also refers to terminating a voice call from another mobile subscriber, public switched telephone network (Public Switch Telephone Network, PSTN), or other network onto the user equipment.

The term "terminate" means that the message terminates delivery at the user equipment. The term also describes the communication between the Short message service center (Short MESSAGE SERVICE CENTER, SMSC) and the user equipment, and between the Mobile switching center (Mobile SWITCHING CENTER, MSC) and the user equipment.

8, Mobile terminated Small data packet transfer (Mobile Terminated-SMALL DATA Transmission, MT-SDT)

MT-SDT refers to a manner of small packet transmission terminated at a user equipment, also called mobile called small packet transmission. When the user equipment receives downlink data and/or signaling from the network equipment through the MT-SDT manner, signaling overhead and UE power consumption can be reduced by not switching to the RRC connected state, and delay can be reduced by allowing a fast transmission of small data packets (e.g., small data packets for positioning).

Corresponding to MT-SDT is a Mobile originated Small data packet transfer (Mobile Originating-SMALL DATA Transmission, MO-SDT), also known as Mobile caller Small data packet transfer. MO-SDT refers to the manner in which small data packets are transmitted as initiated by a user equipment. When the user equipment sends uplink data and/or signaling to the network equipment in an MO-SDT mode, the transmission of the small data packet can be carried out in an RRC inactive state, so that signaling overhead and UE power consumption are reduced.

9 User equipment Context (UE Context)

During the communication between the UE and the network device, the network device creates a record for the UE called UE Context.

The ue context is used to store ue device information such as a cell phone number, a device number, an IP address, quality of service (Quality of Service, qos) parameters, etc. The user equipment context is used to maintain communication contact with the user equipment during communication and to handle traffic to the user equipment. Herein, the "user equipment Context (UE Context)" is simply referred to as "Context".

Radio Bearer (RB)

The radio bearers include data radio bearers (Data Radio Bearer, DRBs) and signaling radio bearers (SIGNALING RADIO BEARER, SRBs), the DRB types include DRB1, DRB2, etc., and the SRB types include SRB1, SRB2, etc.

Paging based on radio access network (RAN-based Paging)

Paging based on a radio access network refers to a network device initiating Paging (Paging) within a radio access network notification area (RNA) to determine the cell in which the user equipment is located. When the network device receives downlink data/signaling from the core network, a radio access network paging (RAN PAGING) message is triggered. Herein, "RAN-based Paging", "RAN PAGING" and "Paging" are the same concept.

12, Xn interface

The Xn interface refers to an interface for data transmission between two base stations, for example, data transmission between a serving base station and an anchor base station is performed through the Xn interface. The Xn interface may include, but is not limited to, a user plane interface Xn-U, a control plane interface Xn-C, and the like. The user interface Xn-U mainly provides a data forwarding function and a flow control function. The control plane interface Xn-C mainly provides Xn interface management, UE mobility management, dual-connection implementation and other functions.

13, NG interface

The NG interface refers to an interface for data transmission between the radio access network and the core network. The NG interface may include, but is not limited to, a user plane interface NG-U, a control plane interface NG-C, and the like. Wherein the user plane interface NG-U is an interface between the radio access network and a User Plane Function (UPF) of the core network. The control plane interface NG-C is the interface between the radio access network and the control plane function (AMF) of the core network.

It can be appreciated that the 5G New Radio (NR) network includes an RRC connected state and an RRC idle state. In order to improve the efficiency of frequent transmission of small data packets, the 5G NR network introduces an RRC inactive state.

For example, the base station transmits an RRC Release (Release) message carrying a Suspend (Suspend) configuration to a User Equipment (UE) in an RRC connected state to instruct the UE to enter an RRC inactive state. When the UE is in the RRC inactive state, the Context (Context) of the UE is suspended on both the terminal side and the base station side. When data/signaling needs to be sent, the UE triggers the procedure of an RRC Resume Request (Resume Request) to switch the UE from the RRC inactive state to the RRC connected state, and then the UE can send the data/signaling.

Fig. 2 is a schematic diagram illustrating an information interaction scenario in which a UE transitions from an RRC inactive state to an RRC connected state when there is data and/or signaling to be transmitted.

As shown in fig. 2, it can be appreciated that when the UE is in the RRC inactive state, if the UE needs to transmit data/signaling, the User Equipment (UE) transmits an RRC resume request (RRC Resume Request) message to the serving base station (see S201) to request a handover to the RRC connected state.

The serving base station transmits a retrieve user equipment Context request (Retrieve UE Context Request) message to the anchor base station (see S202) to acquire a user equipment Context (UE Context).

The anchor base station transmits a retrieve user equipment Context response (Retrieve UE Context Response) message to the serving base station in response to the retrieve user equipment Context request message (see S203), the retrieve user equipment Context response message carrying a user equipment Context (UE Context).

After the serving base station acquires the context, it transmits an RRC Resume (RRC Resume) message to the user equipment (see S204) to inform the user equipment to switch to the RRC connected state.

After the user equipment is switched from the RRC inactive state to the RRC connected state, an RRC resume complete (RRC Resume Complete) message is sent to the serving base station (see S205) to inform the serving base station that the user equipment has been switched to the RRC connected state.

The serving base station sends an Xn-U interface address indication (Xn-U Address Indication) message to the anchor base station (see S206), which carries the data forwarding address. The service base station provides the data forwarding address for the anchor base station, so that the downlink data cached by the anchor base station in the data transmission process can be prevented from being lost.

The serving base station sends a path switch Request (PATH SWITCH Request) message to the core network (e.g., AMF) (see S207) to Request a handover of the downlink termination point of the NG interface transport bearer to a new termination point.

The core network transmits a path switch Response (PATH SWITCH Response) message to the serving base station in Response to the path switch request (see S208) to inform the serving base station NG that the downlink of the transport bearer has been switched to the new termination point.

The serving base station sends a user equipment context release (UE Context Release) message to the anchor base station (see S209) to instruct the anchor base station to release its cached context.

As another example, referring to fig. 3, fig. 3 is a schematic diagram of another information interaction scenario in which a UE transitions from an RRC inactive state to an RRC connected state when there is data and/or signaling to be transmitted.

As shown in fig. 3, it may be understood that, when the UE is in the RRC inactive state, if the anchor base station receives downlink data/signaling from the core network, the anchor base station pages the UE in the radio access network notification area (RAN-based Notification Area, RNA), and may directly send a Paging (Paging) message to the UE, or may forward the Paging message to the UE through the serving base station. For example, the anchor base station transmits a radio access network paging (RAN PAGING) message to the serving base station (see S301) to inform the serving base station to page the user equipment within a radio access network notification area (RNA).

The serving base station transmits a radio access network paging message to the user equipment (see S302). It is appreciated that the radio access network paging message may include an inactive radio network temporary identity ((Inactive Radio Network Tempory Identity, I-RNTI)). The serving base station may page a user equipment (Paging UE) over an air interface through the I-RNTI. Wherein the I-RNTI is used to identify a UE to indicate paging for a particular UE.

When the ue is successfully paged, the ue triggers the flow of the RRC Resume request (see S303, i.e., steps S201 to S209 in fig. 2), switches from the RRC inactive state to the RRC connected state (Resume from RRC INACTIVE STATE), and then receives downlink data/signaling (not shown in the figure).

After the ue successfully receives the downlink data/signaling, the serving bs sends a release context message to the ue, and the ue again transitions from the RRC connected state to the RRC inactive state.

As shown in fig. 2 and 3, if data/signaling is transmitted frequently, the ue will frequently perform state transition, resulting in excessive signaling overhead.

Furthermore, there is no related solution to how to trigger downlink small packet transmission for the mobile called (MT) scenario.

Based on this, the present application provides a data transmission method, a network device and a computer storage medium, aiming at an MT-SDT trigger mechanism of a UE in an RRC inactive state, that is, triggering an MT-SDT in an RRC inactive state of the UE to receive a small data packet of an initial downlink and transmit a subsequent small data packet of an uplink or downlink. In a mobile called (MT) scene, triggering downlink small data packet transmission (SDT) to inform user equipment to receive data/signaling in an RRC inactive state, thereby reducing signaling overhead caused by state transition of the user equipment, reducing signaling number between interfaces of a service base station and an anchor base station, and reducing service delay.

It should be noted that, the UE is switched from the RRC connected state to the RRC inactive state under the service of the Anchor base station (Anchor gNB), and the Anchor base station stores the UE Context (UE Context) which is the same as or a part of the UE Context in the RRC connected state. Subsequently, the user equipment in the RRC inactive state moves within a radio access network based notification area (RNA), and there are the following two scenarios.

In a first scenario, a user equipment enters a service range of a Serving base station (Serving gNB), receives a broadcast signal of the Serving base station, and performs data transmission with a core network through the Serving base station. When the anchor base station receives downlink data/signaling from the core network, the anchor base station triggers a radio access network paging (RAN PAGING) message. When the paging message broadcast by the anchor base station in the service range is not responded by the user equipment, the paging message is sent to the service base station, and the service base station continues to broadcast the paging message. When the serving base station receives the response message of the user equipment, it may be determined that the user equipment is currently within the service range of the serving base station. As such, the anchor base station needs to forward downlink data/signaling to the user equipment through the serving base station.

And in a second scenario, the user equipment is still in the service range of the Anchor base station (Anchor gNB), continuously receives the broadcast signal of the Anchor base station, and performs data transmission with the core network through the Anchor base station. That is, the anchor base station is the same base station as the serving base station. When the anchor base station receives downlink data/signaling from the core network, the anchor base station triggers a radio access network paging (RAN PAGING) message. When the anchor base station receives the response message of the user equipment, it may be determined that the user equipment is currently within the service range of the anchor base station. At this time, the anchor base station may directly transmit downlink data/signaling to the ue.

It can be appreciated that the difference between the first scenario and the second scenario is that the anchor base station in the first scenario needs to forward the downlink data/signaling to the ue through the serving base station. In the second scenario, the anchor base station and the serving base station are the same base station, so that the anchor base station can directly send downlink data/signaling to the user equipment.

It will be understood that, for convenience of description, the technical solution in the embodiment of the present application will be clearly and completely described by taking a scene one as an example with reference to the accompanying drawings in the embodiment of the present application.

Specifically, as shown in fig. 4a, fig. 4a is an information interaction scenario diagram of a data transmission method in a scenario in which an anchor base station performs user equipment context migration. When the ue in the RRC inactive state enters the service range of the serving base station, the data transmission method may include the following steps:

s401a, the anchor base station acquires downlink data/signaling from the core network (Downlink Signaling or Data).

In the embodiment of the present application, the transmission modes of the downlink data/signaling from the core network are MT-SDT modes.

The downlink data/signaling may carry first configuration information, where the first configuration information is used to determine whether to perform user equipment Context (UE Context) migration. The first configuration information may include side information, radio Bearer (RB) information, a packet size, and the like.

The auxiliary information is used for carrying out SDT indication on data to be transmitted so as to indicate the anchor point base station to carry out SDT. The assistance information may include subscription data, capabilities, data transmission statistics, data/signaling traffic characteristics and first indication information related to the SDT by the UE.

The data traffic characteristics may include frequency of single/multiple packets, duration of one session, and size of data volume of one session duration.

The signaling traffic characteristics may include the frequency of the signaling and the packet size of the signaling.

The first indication information is used for indicating triggering MT-SDT.

The radio bearer information may include bearer information configured with at least one of MT-SDT capability, MO-SDT capability, SDT capability.

The packet size may be the size of all packets contained in the downlink data/signaling, or the size of a single packet contained in the downlink data/signaling.

S402a, the anchor base station determines whether to perform user equipment Context (UE Context) migration.

It should be noted that, the embodiment shown in fig. 4a is described by taking the case of performing the context migration of the user equipment as an example.

It is understood that the anchor base station may determine whether to perform the user equipment context migration based on one or more parameters in the first configuration information.

In some embodiments, the anchor base station determines to perform user equipment context migration when at least one of the following conditions is met.

And in the first condition, executing a first implementation algorithm of the anchor base station, and performing user equipment context migration based on the first implementation algorithm.

The first implementation algorithm is used for indicating the context of the migration user equipment.

And secondly, acquiring second indication information from the core network, wherein the second indication information is used for indicating the user equipment context migration.

And thirdly, meeting the first attribute requirement of the service delay, and performing user equipment context migration based on the first attribute requirement of the service delay.

Wherein the first attribute requirement is used to indicate a migrating user device context. The attribute of the service delay refers to the maximum delay allowed by the scheduled downlink data/signaling. When the maximum delay is greater than or equal to the delay threshold, user equipment context migration is required. The latency threshold refers to the minimum latency that triggers the user equipment context migration.

In other embodiments, the anchor base station determines not to perform user equipment context migration when at least one of the following conditions is met.

And in the first condition, executing a second implementation algorithm of the anchor base station, and not performing user equipment context migration based on the second implementation algorithm.

Wherein the second implementation algorithm is used for indicating that the user equipment context is not migrated.

And secondly, acquiring third indication information from the core network, wherein the third indication information is used for indicating that the context migration of the user equipment is not performed.

And thirdly, meeting the second attribute requirement of the service delay, and not performing user equipment context migration based on the second attribute requirement of the service delay.

Wherein the second attribute requirement is for indicating that the user equipment context is not migrated. It can be appreciated that user equipment context migration is not required when the maximum delay allowed for scheduling downlink data/signaling is less than the delay threshold.

For example, in the face of Burst Traffic (Burst Traffic), to reduce the service delay, it is necessary to quickly send downlink data/signaling to the ue without performing ue context migration.

And fourthly, acquiring data transmission statistical information of the SDT service, wherein the data transmission statistical information is used for indicating that the context migration of the user equipment is not performed.

For example, the data transmission statistics include a traffic profile (Traffic Arrtribute) based on which downlink data/signaling needs to be quickly sent to the ue without performing ue context migration.

S403, the anchor base station sends the user equipment Context (UE Context) and downlink data/signaling to the service base station in an MT-SDT mode.

In this embodiment, when it is determined to perform the user equipment context migration, the anchor base station performs step S403.

In some embodiments, when determining to perform user equipment Context migration, the anchor base station may migrate the user equipment Context (UE Context) within a radio access network active area (RNA) and transmit downlink data/signaling to the serving base station.

In other embodiments, the anchor base station may wait to obtain a retrieve user equipment context request (Retrieve UE Context Request) message from the serving base station when it is determined to perform a user equipment context migration. After receiving the retrieve user equipment Context request message, the anchor base station then migrates the user equipment Context (UE Context) within the radio access network active area (RNA) and transmits downlink data/signaling to the serving base station.

S404, the service base station saves the user equipment Context (UE Context) and sends downlink data/signaling to the user equipment in an MT-SDT mode.

In some embodiments, after receiving the user equipment Context (UE Context) and the downlink data/signaling, the serving base station performs path switching with the core network to switch the downlink of the NG interface transport bearer to a new endpoint, for example, to switch the downlink to the serving base station.

S405, the serving base station sends a user equipment Context release (UE Context Release) message to the anchor base station in the MT-SDT manner, so as to instruct the anchor base station to release its cached user equipment Context (UE Context).

It can be understood that in this embodiment, the UE in the RRC inactive state moves in a radio access network notification area (RNA), and when the UE is called, that is, there is downlink data/signaling to be transmitted to the UE, the anchor base station first receives the downlink data/signaling from the core network, and triggers downlink small data packet transmission, that is, transmits the downlink data/signaling in the MT-SDT manner. Then, the anchor base station determines whether to perform user equipment Context (UE Context) migration. When determining to perform the context migration of the user equipment, the anchor base station sends the context of the user equipment and downlink data/signaling to the serving base station in an MT-SDT mode. The service base station saves the user equipment context and sends downlink data/signaling to the user equipment in an MT-SDT mode. In this way, the downlink data/signaling from the core network is transmitted in MT-SDT mode, and in the mobile called scenario, the anchor base station may send the downlink data/signaling to the serving base station during the period that the UE is in the RRC inactive state, and then forward the downlink data/signaling to the UE through the serving base station, without the UE switching from the RRC inactive state to the RRC connected state. By the method, the number of signaling between interfaces of the service base station and the anchor base station can be reduced, signaling overhead caused by state transition of the UE is reduced, and therefore service delay is reduced.

Fig. 4b is a schematic diagram of an information interaction scenario of a data transmission method in a scenario in which an anchor base station does not perform context migration of a user equipment, as shown in fig. 4 b. Referring to fig. 4b, the data transmission method may include the steps of:

s401b, the anchor base station acquires downlink data/signaling from the core network (Downlink Signaling or Data).

Wherein the downlink data/signaling carries the first configuration information.

It will be appreciated that when the UE is called, the downlink data/signaling issued by the core network needs to be transmitted to the UE. At this time, the anchor base station first acquires downlink data/signaling issued by the core network.

S402b, the anchor base station determines whether to perform user equipment Context (UE Context) migration.

It should be noted that the embodiment shown in fig. 4b is described by taking an example that no context migration of the user equipment is performed.

In this embodiment, when downlink data/signaling from the core network is received, the anchor base station may determine whether to perform the user equipment context migration according to first configuration information carried by the downlink data/signaling. Compared with the scheme of performing the user equipment context migration by default, the embodiment can be determined according to actual requirements, so that signaling resources can be saved, and the problem that the signaling resources are wasted due to the fact that the user equipment context migration is performed under unnecessary conditions is avoided.

It will be appreciated that steps S401b to S402b in fig. 4b are identical to steps S401a to S402a in fig. 4 a.

S406, the anchor base station obtains a retrieve user equipment context request (Retrieve UE Context Request) message from the serving base station.

In this embodiment, when it is determined that the user equipment context migration is not performed, the anchor base station performs step S406.

Wherein the user equipment context request message is retrieved for requesting the user equipment context.

S407, the anchor base station sends a retrieve user equipment context failure (Retrieve UE Context Failure) message and downlink data/signaling (Downlink Data or Signaling) to the serving base station in MT-SDT manner in response to the retrieve user equipment context request (Retrieve UE Context Request) message.

In this embodiment, since it is determined that the ue context migration is not performed, when receiving the ue context retrieving request message from the serving base station, the anchor base station does not send all ue contexts, but feeds back a ue context retrieving failure message to the serving base station to notify the serving base station that all ue contexts cannot be acquired.

S408, the service base station sends downlink data/signaling to the user equipment in MT-SDT mode.

In other embodiments, the anchor base station transmits a retrieve user equipment context failure message and encrypted downlink data/signaling (ENCRYPTED DOWNLINK DATA OR SIGNALING) to the serving base station in MT-SDT fashion in response to the retrieve user equipment context request message. The serving base station decrypts the encrypted downlink data/signaling (ENCRYPTED DOWNLINK DATA OR SIGNALING) to obtain the downlink data/signaling (Downlink Data or Signaling), and sends the downlink data/signaling to the ue in MT-SDT mode.

The anchor base station may encrypt downlink data/signaling (Downlink Data or Signaling) from the core network through an encryption algorithm to obtain encrypted downlink data/signaling (ENCRYPTED DOWNLINK DATA OR SIGNALING). The serving base station may decrypt the encrypted downlink data/signaling (ENCRYPTED DOWNLINK DATA OR SIGNALING) using a key corresponding to the encryption algorithm to obtain the downlink data/signaling (Downlink Data or Signaling) issued by the core network.

In some embodiments, after the serving base station acquires the downlink data/signaling (Downlink Data or Signaling), a path switch is performed between the serving base station and the core network, so as to switch the downlink to the serving base station.

In other embodiments, the anchor base station may migrate a portion of the user equipment context (Partial UE Context) within the radio access network active area (RNA) and transmit downlink data/signaling to the serving base station.

It can be understood that in this embodiment, the UE in the RRC inactive state moves in a radio access network notification area (RNA), and when the UE is called, that is, there is downlink data/signaling to be transmitted to the UE, the anchor base station first receives the downlink data/signaling from the core network, and triggers downlink small data packet transmission, that is, transmits the downlink data/signaling in the MT-SDT manner. Then, the anchor base station determines whether to perform user equipment Context (UE Context) migration. When it is determined that the user equipment context migration is not performed, if the anchor base station receives a request (Retrieve UE Context Request) for retrieving the user equipment context from the serving base station, downlink data/signaling is sent to the serving base station in an MT-SDT manner. The service base station sends downlink data/signaling to the user equipment in an MT-SDT mode. In this way, the downlink data/signaling from the core network is transmitted in MT-SDT mode, and in the mobile called scenario, the anchor base station may send the downlink data/signaling to the serving base station during the period that the UE is in the RRC inactive state, and then forward the downlink data/signaling to the UE through the serving base station, without the UE switching from the RRC inactive state to the RRC connected state. By the method, the number of signaling between interfaces of the service base station and the anchor base station can be reduced, signaling overhead caused by state transition of the UE is reduced, and therefore service delay is reduced.

The data transmission method provided by the application is specifically described by a specific embodiment.

Example 1

Fig. 5 is an information interaction schematic diagram of a data transmission method in a scenario in which an anchor base station performs user equipment context migration. Referring to fig. 5, the data transmission method may include the steps of:

S501, the anchor base station acquires downlink data/signaling from the core network (Downlink Signaling or Data).

S502, the anchor base station determines whether to perform user equipment Context (UE Context) migration.

The embodiment shown in fig. 5 is described by taking the case of performing the context migration of the user equipment as an example.

S503, the anchor base station sends a Paging (Paging) message to the serving base station, wherein the Paging message carries first indication information.

The first indication information is used for indicating triggering MT-SDT. The first indication information may include a cause value (e.g., MT-SDT or SDT), a bearer type, and priority information.

For example, the cause value MT-SDT is used to indicate that downlink data or signaling is transmitted in the MT-SDT manner, and the cause value SDT is used to indicate that downlink data or signaling is transmitted in the SDT manner.

The Bearer type is used to indicate to which Radio Bearer (RB) type the downlink data or signaling (Downlink Data or Signaling) belongs, e.g., which type of data Radio Bearer (Data Radio Bearer, DRB) (e.g., DRB1 or DRB 2) belongs, or which type of signaling Radio Bearer (SIGNALING RADIO BEARER, SRB) (e.g., SRB1 or SRB 2) belongs.

The priority information is used to indicate the priority of a Paging (Paging) message, which may be indicated as high priority, for example.

S504, the serving base station sends a Paging (Paging) message to the user equipment.

S505, after receiving the paging message, the UE sends an RRC recovery request (RRC Resume Request) message to the serving base station, where the RRC recovery request message carries the first indication information.

It will be appreciated that the RRC resume request message is used to request establishment of an MT-SDT session, which may be used for data transfer of MT-SDT services. After the UE is successfully paged, the UE triggers MT-SDT according to the first indication information carried by the paging message so as to request the transmission of downlink data/signaling in an MT-SDT mode.

In this embodiment, the purpose of the RRC recovery request message carrying the first indication information is to request downlink data/signaling to be transmitted in the MT-SDT manner.

S506, after receiving the RRC recovery request message, the service base station sends a request (Retrieve UE Context Request) for retrieving the user equipment context to the anchor base station, wherein the request for retrieving the user equipment context carries the first indication information and a Downlink Address (Downlink Address).

The downlink address may include, among other things, an address and port number of a GPRS tunneling protocol (GPRS Tunnelling Protocol, GTP).

It will be appreciated that retrieving the user equipment context request message is used to request acquisition of the user equipment context from the anchor base station to manage the RRC state of the UE.

S507, after receiving the request message for retrieving the context of the ue, the anchor base station sends a message for retrieving the context of the ue (Retrieve UE Context Response) and downlink data/signaling (Downlink Data or Signaling) to the serving base station.

Wherein the retrieving user equipment context response message carries the user equipment context, it may also carry at least one of packet size, frequency and side information that allows transmission.

It will be appreciated that after receiving the request message for retrieving the context of the user equipment, the anchor base station triggers the MT-SDT according to the first indication information, and transmits the response message for retrieving the context of the user equipment and downlink data/signaling to the serving base station in the manner of MT-SDT through the downlink address.

S508, the serving base station transmits a path switch Request (PATH SWITCH Request) message to the core network to switch the downlink to the serving base station.

The core network sends a path switch Response (PATH SWITCH Response) message to the serving base station to inform the serving base station that the downlink has completed the handover S509.

S510, the service base station sends downlink data/signaling (Downlink Data or Signaling) to the user equipment.

The serving base station may schedule downlink data/signaling according to a base station implementation algorithm, auxiliary information, or first indication information in the auxiliary information. The base station implementation algorithm includes various algorithms for implementing the functions of the base station, such as an algorithm for implementing load balancing, positioning, and data encryption/decryption.

S511, the core network sends the subsequent downlink data/signaling (Subsequent Downlink Data or Signaling) to the user equipment.

It will be appreciated that subsequent downstream data/signalling from the core network may be forwarded directly by the serving base station to the user equipment after path switching is completed.

S512, the serving base station sends a user equipment Context release (UE Context Release) message to the anchor base station to instruct the anchor base station to release its cached user equipment Context (UE Context).

S513, the serving base station sends an RRC release (RRC RELEASE) message to the user equipment to instruct the user equipment to enter an RRC inactive state or idle state (IDLE STATE).

It is understood that the RRC release message is used to indicate termination of the MT-SDT session. The serving base station may instruct termination of the MT-SDT session based on certain criteria. For example, the serving base station may instruct termination of the MT-SDT session when the duration of the MT-SDT service ends or the data transmission of the MT-SDT service is completed.

In this embodiment, in a mobile called (MT) scenario, when an anchor base station determines to perform user equipment Context (UE Context) migration, if a UE is called, that is, the anchor base station receives downlink data/signaling (Downlink Data or Signaling) from a core network, a Paging (Paging) message carrying first indication information is triggered in a radio access network notification area. After receiving the paging message, the user equipment triggers an RRC resume request (RRC Resume Request) message to instruct the serving base station to resume the suspended bearer. After receiving the RRC resume request message, the serving base station triggers retrieval of a user equipment context request (Retrieve UE Context Request) message. After receiving the request message for restoring the context of the user equipment, the anchor base station triggers the retrieval of the context response (Retrieve UE Context Response) message of the user equipment and sends downlink data/signaling to the service base station. After the serving base station performs path conversion with the core network, the core network may directly schedule subsequent downlink data/signaling (Subsequent Downlink Data or Signaling) to the ue. The serving base station triggers a user equipment Context release (UE Context Release) message to the anchor base station to instruct the anchor base station to release its cached user equipment Context (UE Context), and sends an RRC release (RRC RELEASE) message to the user equipment to instruct the user equipment to enter an RRC inactive state or idle state.

Example 2

Embodiment 2 differs from embodiment 1 in that after step S512 in embodiment 1, the serving base station triggers an RRC Resume (RRC Resume) message to instruct the user equipment to enter an RRC connected state.

Fig. 6 is an information interaction schematic diagram of another data transmission method in a scenario in which an anchor base station performs user equipment context migration. Referring to fig. 6, the data transmission method may include the steps of:

S601, the anchor base station acquires downlink data/signaling from the core network (Downlink Signaling or Data).

S602, the anchor base station determines whether to perform user equipment Context (UE Context) migration.

S603, the anchor base station sends a Paging (Paging) message to the serving base station, wherein the Paging message carries first indication information.

S604, the serving base station sends a Paging (Paging) message to the user equipment.

S605, after receiving the paging message, the user equipment sends an RRC recovery request (RRC Resume Request) message to the serving base station, wherein the RRC recovery request message carries first indication information.

S606, after receiving the RRC recovery request message, the service base station sends a request (Retrieve UE Context Request) for retrieving the user equipment context to the anchor base station, wherein the request for retrieving the user equipment context carries the first indication information and a Downlink Address (Downlink Address).

S607, after receiving the request message for retrieving the ue context, the anchor base station sends a message for retrieving the ue context response (Retrieve UE Context Response) and downlink data/signaling (Downlink Data or Signaling) to the serving base station.

S608, the serving base station transmits a path switch Request (PATH SWITCH Request) message to the core network to switch the downlink to the serving base station.

The core network transmits a path switch Response (PATH SWITCH Response) message to the serving base station to inform the serving base station that the downlink has completed handover S609.

S610, the serving base station sends downlink data/signaling (Downlink Data or Signaling) to the user equipment.

S611, the core network sends the subsequent downlink data/signaling (Subsequent Downlink Data or Signaling) to the ue.

S612, the serving base station sends a user equipment Context release (UE Context Release) message to the anchor base station to instruct the anchor base station to release its cached user equipment Context (UE Context).

It is understood that steps S601 to S612 are the same as steps S501 to S512 in embodiment 1, and are not described herein.

S613, the serving base station determines whether to instruct the user equipment to switch to the RRC connected state.

The embodiment shown in fig. 6 is described by taking an example of instructing the ue to switch to the RRC connected state.

Wherein the serving base station determines to instruct the user equipment to switch to the RRC connected state when at least one of the following conditions is met.

And (5) updating the security context information according to the first condition. When the downstream data/signaling needs to be encrypted and integrity protected for security reasons, the serving base station updates the security context information.

And secondly, acquiring downlink data carried by Non-mobile termination small data packet transmission (Non-MT-SDT). The Non-mobile terminated small data packet transfer (Non-MT-SDT) bearer refers to a bearer which does not support the mobile terminated small data packet transfer (MT-SDT) function.

And thirdly, the size of the data packet is larger than a first preset threshold value. The size of the data packet may be the size of a single data packet or the size of the total data volume. The size of the total data amount refers to the total data amount size allowed to be transmitted during mobile terminated small data packet transfer (MT-SDT). The size of the total data amount may be the size of the downstream and/or upstream data amount.

And the fourth condition is that the number of the data packets is larger than a second preset threshold value. Wherein the number of data packets refers to the number of downstream data packets sent and/or upstream data packets received during small data packet transfer (SDT).

It can be understood that the value of the first preset threshold value/the second preset threshold value is related to factors such as transmission bandwidth, transmission rate, transmission quality, etc., and the base station can set the first preset threshold value/the second preset threshold value according to the data transmission situation.

S614, the serving base station transmits an RRC Resume (RRC Resume) message to the user equipment to instruct the user equipment to enter an RRC connected state.

S615, after entering the RRC connection state, the user equipment sends an RRC recovery complete (RRC Resume Complete) message to the serving base station.

The RRC recovery complete message is used to notify the serving base station that the ue has entered the RRC connected state.

It can be appreciated that in this embodiment, in a mobile called (MT) scenario, the anchor base station determines to perform user equipment Context (UE Context) migration, and after the serving base station sends a user equipment Context release (UE Context Release) message to the anchor base station, determines whether to instruct the user equipment to switch to the RRC connected state. When determining to instruct the user equipment to switch to the RRC connected state, the serving base station triggers an RRC Resume (RRC Resume) message to instruct the user equipment to enter the RRC connected state. When the user equipment enters the RRC connected state, an RRC resume complete (RRC Resume Complete) message is triggered. The user equipment may receive downlink data/signaling during an RRC inactive state before switching to an RRC connected state (Downlink Data or Signaling).

Example 3

Embodiment 3 differs from embodiment 1 in that after step S507 in embodiment 1, the serving base station triggers an RRC release (RRC RELEASE) message to instruct the user equipment to enter an RRC inactive state or an idle state.

Fig. 7 is an information interaction diagram of another data transmission method in a scenario in which an anchor base station performs user equipment context migration.

Referring to fig. 7, the data transmission method may include the steps of:

s701, the anchor base station acquires downlink data/signaling from the core network (Downlink Signaling or Data).

S702, the anchor base station determines whether to perform user equipment Context (UE Context) migration.

S703, the anchor base station sends a Paging (Paging) message to the serving base station, wherein the Paging message carries the first indication information.

S704, the serving base station sends a Paging (Paging) message to the user equipment.

S705, after receiving the paging message, the UE sends an RRC recovery request (RRC Resume Request) message to the serving base station, where the RRC recovery request message carries the first indication information.

S706, after receiving the RRC resume request message, the serving base station sends a request (Retrieve UE Context Request) for retrieving the user equipment context to the anchor base station, where the request for retrieving the user equipment context carries the first indication information and a Downlink Address (Downlink Address).

S707, after receiving the request message for retrieving the context of the ue, the anchor base station sends a message for retrieving the context of the ue (Retrieve UE Context Response) and downlink data/signaling (Downlink Data or Signaling) to the serving base station.

It is understood that steps S701 to S707 are the same as steps S501 to S507 in embodiment 1, and are not described herein.

S708, the serving base station determines whether to instruct the user equipment to enter an RRC inactive state or an idle state.

It should be noted that the embodiment shown in fig. 7 is described by taking an example of instructing the ue to enter the RRC inactive state or the idle state.

Wherein the serving base station determines to instruct the user equipment to enter an RRC inactive state or an idle state when at least one of the following conditions is satisfied.

And the first condition is that a base station implementation algorithm is executed, and the user equipment is configured to enter an RRC inactive state or an idle state based on the algorithm implementation.

And secondly, acquiring auxiliary information, wherein the auxiliary information is used for carrying out SDT indication on data to be transmitted so as to indicate a service base station to carry out SDT.

And thirdly, acquiring first indication information, wherein the first indication information is used for indicating the service base station to trigger MT-SDT.

S709, the serving base station transmits an RRC release (RRC RELEASE) message to the user equipment to instruct the user equipment to enter an RRC inactive state or idle state, and transmits downlink data/signaling (Downlink Data or Signaling) to the user equipment.

In this embodiment, the serving base station transmits downlink data/signaling together when triggering the RRC release message, so that the number of signaling between the serving base station and the user equipment can be reduced, thereby reducing MT-SDT service delay.

S710, the serving base station transmits a path switch Request (PATH SWITCH Request) message to the core network to switch the downlink to the serving base station.

The core network transmits a path switch Response (PATH SWITCH Response) message to the serving base station to inform the serving base station that the downlink has completed handover S711.

It is understood that steps S710 to S711 are the same as steps S508 to S509 in embodiment 1, and will not be described here.

S712, the serving base station sends a user equipment Context release (UE Context Release) message to the anchor base station to instruct the anchor base station to release its cached user equipment Context (UE Context).

It can be appreciated that in this embodiment, in a mobile called (MT) scenario, the anchor base station determines to perform a user equipment Context (UE Context) migration, and after the anchor base station sends a retrieve user equipment Context response (Retrieve UE Context Response) message and downlink data/signaling (Downlink Data or Signaling) to the serving base station, the serving base station determines whether to instruct the user equipment to enter an RRC inactive state or idle state. When it is determined to instruct the user equipment to enter an RRC inactive state or an idle state, the serving base station triggers an RRC release (RRC RELEASE) message and sends downlink data/signaling (Downlink Data or Signaling) to the user equipment. After the serving base station performs path conversion with the core network, a user equipment Context release (UE Context Release) message is triggered to instruct the anchor base station to release its cached user equipment Context (UE Context).

Example 4

Embodiment 4 differs from embodiment 1 in that after step S507 in embodiment 1, the serving base station triggers an RRC Resume (RRC Resume) message to instruct the user equipment to enter an RRC connected state.

Fig. 8 is an information interaction diagram of another data transmission method in a scenario in which an anchor base station performs user equipment context migration.

Referring to fig. 8, the data transmission method may include the steps of:

s801, an anchor base station acquires downlink data/signaling from a core network (Downlink Signaling or Data).

S802, the anchor base station determines whether to perform user equipment Context (UE Context) migration.

S803, the anchor base station sends a Paging (Paging) message to the serving base station, wherein the Paging message carries first indication information.

S804, the serving base station transmits a Paging (Paging) message to the user equipment.

S805, after receiving the paging message, the UE sends an RRC recovery request (RRC Resume Request) message to the serving base station, where the RRC recovery request message carries the first indication information.

S806, after receiving the RRC resume request message, the serving base station sends a request (Retrieve UE Context Request) for retrieving the user equipment context to the anchor base station, where the request for retrieving the user equipment context carries the first indication information and a Downlink Address (Downlink Address).

S807, after receiving the request message for retrieving the user equipment context, the anchor base station transmits a message for retrieving the user equipment context response (Retrieve UE Context Response) and downlink data/signaling (Downlink Data or Signaling) to the serving base station.

It is understood that steps S801 to S807 are the same as steps S501 to S507 in embodiment 1, and are not described here.

S808, the serving base station determines whether to instruct the user equipment to switch to the RRC connected state.

The embodiment shown in fig. 8 is described by taking an example of instructing the ue to switch to the RRC connected state.

It is understood that step S808 is the same as step S613 in embodiment 2, and will not be described here.

S809, the serving base station sends an RRC Resume (RRC Resume) message to the user equipment to instruct the user equipment to enter an RRC connected state, and sends downlink data/signaling (Downlink Data or Signaling) to the user equipment.

In this embodiment, the serving base station transmits downlink data/signaling together when triggering the RRC restore message, so that the number of signaling between the serving base station and the user equipment can be reduced, thereby reducing MT-SDT service delay.

S810, after entering the RRC connection state, the user equipment sends an RRC recovery complete (RRC Resume Complete) message to the serving base station.

It will be appreciated that in other embodiments, the RRC resume complete message may not be sent.

S811, the serving base station transmits a path switch Request (PATH SWITCH Request) message to the core network to switch the downlink to the serving base station.

The core network transmits a path switch Response (PATH SWITCH Response) message to the serving base station to inform the serving base station that the downlink has completed handover S812.

It is understood that steps S811 to S812 are the same as steps S508 to S509 in embodiment 1, and are not described herein.

S813, the serving base station sends a user equipment Context release (UE Context Release) message to the anchor base station to instruct the anchor base station to release its cached user equipment Context (UE Context).

It can be appreciated that in this embodiment, in a mobile called (MT) scenario, the anchor base station determines to perform a user equipment Context (UE Context) migration, and after the anchor base station sends a retrieve user equipment Context response (Retrieve UE Context Response) message and downlink data/signaling (Downlink Data or Signaling) to the serving base station, the serving base station determines whether to instruct the user equipment to switch to the RRC connected state. When determining to instruct the user equipment to switch to the RRC connected state, the serving base station triggers an RRC Resume (RRC Resume) message to instruct the user equipment to enter the RRC connected state, and transmits downlink data/signaling (Downlink Data or Signaling) to the user equipment. After the serving base station performs path conversion with the core network, a user equipment Context release (UE Context Release) message is triggered to instruct the anchor base station to release its cached user equipment Context (UE Context).

Example 5

Embodiment 5 differs from embodiment 1 in that when the anchor base station determines to perform a user equipment Context (UE Context) migration, the anchor base station triggers a Paging message and sends the user equipment Context (UE Context) and downlink data/signaling (Downlink Data or Signaling) to the serving base station.

Fig. 9 is an information interaction diagram of another data transmission method in a scenario in which an anchor base station performs user equipment context migration.

Referring to fig. 9, the data transmission method may include the steps of:

s901, the anchor base station acquires downlink data/signaling from the core network (Downlink Signaling or Data).

S902, the anchor base station determines whether to perform user equipment Context (UE Context) migration.

It is understood that steps S901 to S902 are the same as steps S601 to S602 in embodiment 1, and will not be described here.

S903, the anchor base station sends a Paging (Paging) message, a user equipment Context (UE Context) and downlink data/signaling (Downlink Data or Signaling) to the serving base station, wherein the Paging message carries first indication information.

The address of the service base station receiving the downlink data/signaling is a default configuration address, or an address negotiated by the service base station and the anchor base station when the Xn interface is established.

In this embodiment, the anchor base station transmits the ue context and downlink data/signaling together when triggering the paging message, so that the number of signaling between the anchor base station and the serving base station can be reduced, thereby reducing the MT-SDT service delay.

S904, the serving base station sends a Paging (Paging) message to the user equipment.

S905, after receiving the paging message, the UE sends an RRC recovery request (RRC Resume Request) message to the serving base station, where the RRC recovery request message carries the first indication information.

The RRC recovery request message is used for requesting to establish MT-SDT session, and the MT-SDT session is used for transmitting downlink data/signaling of MT-SDT service.

S906, the serving base station transmits downlink data/signaling (Downlink Data or Signaling) to the user equipment.

It can be appreciated that the serving base station transmits downstream data/signaling in MT-SDT fashion after the MT-SDT session is established.

S907, the serving base station sends a path switch Request (PATH SWITCH Request) message to the core network to switch the downlink to the serving base station.

S908, the core network sends a path switch Response (PATH SWITCH Response) message to the serving base station to inform the serving base station that the downlink has completed the handover.

It is understood that steps S907 to S908 are the same as steps S508 to S509 in embodiment 1, and are not described herein.

S909, the core network sends the subsequent downlink data/signaling (Subsequent Downlink Data or Signaling) to the user equipment.

S910, the serving base station sends a user equipment Context release (UE Context Release) message to the anchor base station to instruct the anchor base station to release its cached user equipment Context (UE Context).

S911, the serving base station transmits an RRC release (RRC RELEASE) message to the user equipment to instruct the user equipment to enter an RRC inactive state or idle state.

Wherein the RRC release message is used to indicate termination of the MT-SDT session.

It can be appreciated that in this embodiment, in a mobile called (MT) scenario, when the anchor base station determines to perform the UE Context migration, the anchor base station sends a Paging (Paging) message, a UE Context (UE Context), and downlink data/signaling (Downlink Data or Signaling) to the serving base station. After receiving the paging message, the ue triggers an RRC resume request (RRC Resume Request) message to instruct the serving base station to resume the suspended bearer. After receiving the RRC resume request message, the serving base station sends downlink data/signaling (Downlink Data or Signaling) to the user equipment. After the serving base station performs path conversion with the core network, the core network may directly schedule subsequent downlink data/signaling (Subsequent Downlink Data or Signaling) to the ue. The serving base station triggers a user equipment Context release (UE Context Release) message to the anchor base station to instruct the anchor base station to release its cached user equipment Context (UE Context), and sends an RRC release (RRC RELEASE) message to the user equipment to instruct the user equipment to enter an RRC inactive state or idle state.

Example 6

Embodiment 6 differs from embodiment 5 in that after step S905 in embodiment 5, the serving base station triggers an RRC Resume (RRC Resume) message and sends downlink data/signaling (Downlink Data or Signaling) to the user equipment.

Fig. 10 is an information interaction diagram of another data transmission method in a scenario in which an anchor base station performs user equipment context migration.

Referring to fig. 10, the data transmission method may include the steps of:

s1001, the anchor base station acquires downlink data/signaling from the core network (Downlink Signaling or Data).

S1002, the anchor base station determines whether to perform user equipment Context (UE Context) migration.

S1003, the anchor base station sends a Paging (Paging) message, a user equipment Context (UE Context), and downlink data/signaling (Downlink Data or Signaling) to the serving base station, where the Paging message carries the first indication information.

S1004, the serving base station sends a Paging (Paging) message to the user equipment.

S1005, after receiving the paging message, the UE sends an RRC recovery request (RRC Resume Request) message to the serving base station, where the RRC recovery request message carries the first indication information.

It is understood that steps S1001 to S1005 are the same as steps S901 to S905 in embodiment 5, and will not be described here.

S1006, the serving base station determines whether to instruct the user equipment to switch to the RRC connected state.

The embodiment shown in fig. 10 is described by taking an example of instructing the ue to switch to the RRC connected state.

It is understood that the specific implementation of step S1006 is the same as step S613 in embodiment 2, and will not be repeated here.

S1007, the serving base station sends an RRC Resume (RRC Resume) message to the user equipment to instruct the user equipment to enter an RRC connected state, and sends downlink data/signaling (Downlink Data or Signaling) to the user equipment.

And S1008, after entering the RRC connection state, the user equipment sends an RRC recovery complete (RRC Resume Complete) message to the service base station.

S1009, the serving base station transmits a path switch Request (PATH SWITCH Request) message to the core network to switch the downlink to the serving base station.

The core network transmits a path switch Response (PATH SWITCH Response) message to the serving base station to inform the serving base station that the downlink has completed handover S1010.

It is understood that steps S1009 to S1010 are the same as steps S907 to S908 in embodiment 5, and are not repeated here.

S1011, the serving base station sends a user equipment Context release (UE Context Release) message to the anchor base station to instruct the anchor base station to release its cached user equipment Context (UE Context).

It can be appreciated that, in this embodiment, in a mobile called (MT) scenario, the anchor base station determines to perform a user equipment Context (UE Context) migration, and after the UE triggers an RRC resume request (RRC Resume Request) message, the serving base station determines whether to instruct the UE to switch to the RRC connected state. When determining to instruct the user equipment to switch to the RRC connected state, the serving base station transmits an RRC Resume (RRC Resume) message to the user equipment to instruct the user equipment to enter the RRC connected state, and transmits downlink data/signaling (Downlink Data or Signaling) to the user equipment. When the user equipment enters the RRC connected state, an RRC resume complete (RRC Resume Complete) message is triggered. After the serving base station performs path conversion with the core network, a user equipment Context release (UE Context Release) message is triggered to instruct the anchor base station to release its cached user equipment Context (UE Context). The user equipment may receive downlink data/signaling during an RRC inactive state before entering an RRC connected state (Downlink Data or Signaling).

Example 7

Fig. 11 is an information interaction diagram of a data transmission method in a scenario in which an anchor base station does not perform user equipment context migration.

Referring to fig. 11, the data transmission method may include the steps of:

s1101, the anchor base station acquires downlink data/signaling from the core network (Downlink Signaling or Data).

S1102, the anchor base station determines whether to perform user equipment Context (UE Context) migration.

The embodiment shown in fig. 11 is described by taking an example in which no context migration of the user equipment is performed.

S1103, the anchor base station sends a user equipment part context setup request (UE Partial Context Setup Request) message to the serving base station.

Wherein the user equipment part context setting request message is used for requesting transmission of part of the user equipment context. The user equipment part context setting request message carries second configuration information, and the second configuration information is used for configuring a data transmission mode (such as MT-SDT or SDT, etc.) in a scene of not performing user equipment context migration.

Note that, the anchor base station does not perform the context migration of the user equipment means that all the contexts are not migrated. For a part of the user equipment context necessary for satisfying the information transmission between the serving base station and the user equipment, the anchor base station still needs to transmit the part of the user equipment context to the serving base station.

The second configuration information may include a Paging (Paging) message, a partial user equipment context (Partial UE Context), a protocol data unit (Protocol Data Unit, PDU) of a packet data convergence protocol (PACKET DATA Convergence Protocol, PDCP) layer of the downlink data/signaling, and an address (e.g., GTP tunnel address and port number) where the anchor base station receives the uplink data.

The Paging (Paging) message carries first indication information, where the first indication information is used to indicate triggering MT-SDT.

The partial user equipment Context (Partial UE Context) may include a Context (Context) of a radio link Control (Radio Link Control, RLC) layer and a Context (Context) of a medium access Control (MEDIA ACCESS Control, MAC) layer.

The protocol data units (PDCP PDUs) of the packet data convergence protocol layer of the downlink data/signaling store downlink data/signaling (Downlink Data or Signaling). A protocol data unit (PDCP PDU) of the packet data convergence protocol layer includes a data PDU for transmitting downlink data of the user plane and the control plane and generating a digital signature of integrity protection, and a control PDU for transmitting a status report and a decompression feedback message of the PDCP layer.

S1104, the serving base station sends a Paging (Paging) message to the ue, where the Paging message carries the first indication information.

S1105, after receiving the paging message, the UE sends an RRC recovery request (RRC Resume Request) message to the serving base station, where the RRC recovery request message carries the first indication information.

In this embodiment, the purpose of the RRC recovery request message carrying the first indication information is to request to establish an MT-SDT session, so as to transmit downlink data/signaling in the MT-SDT manner.

S1106, after receiving the RRC restoration request message, the serving base station sends downlink data/signaling (Downlink Data or Signaling) to the user equipment.

It will be appreciated that in other embodiments, the serving base station may send a path switch request message to the core network to switch the downlink to the serving base station before performing step S1106. After receiving the path switch response message from the core network, the serving base station transmits downlink data/signaling to the user equipment.

S1107, the serving base station transmits a user equipment portion context setup response (UE Partial Context Setup Response) message to the anchor base station.

The user equipment partial context setting response message is used for notifying the anchor base station that the transmission of the partial user equipment context is completed. The user equipment part context setup response message may carry an address where the serving base station receives downlink data, for example, an address of GTP and a port number.

S1108, the anchor base station receives the ue part context setup response message and then sends the subsequent data/signaling (Subsequent Data or Signaling) to the ue.

It can be understood that after receiving the context setting response message of the ue part, the anchor base station transmits the subsequent data/signaling to the serving base station through the address where the serving base station receives the downlink data, and then the serving base station forwards the subsequent data/signaling to the ue.

S1109, the anchor base station transmits an RRC release (RRC RELEASE) message to the user equipment to instruct the user equipment to enter an RRC inactive state or idle state.

It can be understood that after the subsequent data/signaling transmission is completed, the anchor base station transmits an RRC release message to the serving base station through the address where the serving base station receives the downlink data, and then the serving base station forwards the RRC release message to the user equipment, thereby terminating the MT-SDT session.

In this embodiment, in a mobile called (MT) scenario, when the anchor base station determines that no user equipment Context (UE Context) migration is performed, a user equipment part Context setup request (UE Partial Context Setup Request) message is triggered, where the user equipment part Context setup request message carries second configuration information. And after receiving the context setting request message of the user equipment part, the service base station sends the paging message in the second configuration information to the user equipment. After receiving the paging message, the ue sends an RRC resume request (RRC Resume Request) message to the serving base station to instruct the serving base station to resume the suspended bearer. After receiving the RRC resume request message, the serving base station sends downlink data/signaling (Downlink Data or Signaling) to the user equipment and triggers a user equipment part context setup response (UE Partial Context Setup Response) message. The anchor base station may then send subsequent data/signaling (Subsequent Data or Signaling) directly to the user equipment and may trigger an RRC release (RRC RELEASE) message to instruct the user equipment to enter an RRC inactive state or idle state.

Example 8

Embodiment 8 differs from embodiment 7 in that when the anchor base station determines that no user equipment Context (UE Context) migration is performed, the anchor base station does not trigger the user equipment part Context setup request (UE Partial Context Setup Request) message, but triggers the retrieval user equipment Context failure (Retrieve UE Context Failure) message after receiving the retrieval user equipment Context request (Retrieve UE Context Request) message from the serving base station, and sends encrypted downlink data/signaling (ENCRYPTED DOWNLINK DATA OR SIGNALING) to the serving base station.

Fig. 12 is an information interaction diagram of another data transmission method in a scenario in which an anchor base station does not perform user equipment context migration. Referring to fig. 12, the data transmission method may include the steps of:

s1201, the anchor base station acquires downlink data/signaling from the core network (Downlink Signaling or Data).

S1202, the anchor base station determines whether to perform user equipment Context (UE Context) migration.

The embodiment shown in fig. 12 is described by taking an example in which no context migration of the user equipment is performed.

S1203, the anchor base station sends a Paging (Paging) message to the serving base station, where the Paging message carries the first indication information.

The first indication information is used for indicating triggering MT-SDT.

S1204, the serving base station sends a Paging (Paging) message to the user equipment.

S1205, after receiving the paging message, the UE sends an RRC recovery request (RRC Resume Request) message to the serving base station, where the RRC recovery request message carries the first indication information.

S1206, after receiving the RRC resume request message, the serving base station sends a retrieve user equipment context request (Retrieve UE Context Request) message to the anchor base station, where the retrieve user equipment context request message carries the first indication information and a Downlink Address (Downlink Address).

S1207, the anchor base station sends a retrieve user equipment context failure (Retrieve UE Context Failure) message and encrypted downlink data/signaling (ENCRYPTED DOWNLINK DATA OR SIGNALING) to the serving base station.

Wherein retrieving the user equipment context failure message is used to inform the serving base station that all user equipment contexts have not been acquired. The retrieve user device context failure message may carry the address where the anchor base station receives the uplink data, e.g., the address and port number of the GTP.

The anchor base station may encrypt downlink data/signaling (Downlink Data or Signaling) from the core network by an encryption algorithm to obtain encrypted downlink data/signaling (ENCRYPTED DOWNLINK DATA OR SIGNALING).

It will be appreciated that in other embodiments, the anchor base station may also send the downlink data/signaling directly to the serving base station without encrypting the downlink data/signaling.

S1208, the serving base station decrypts the encrypted downlink data/signaling (ENCRYPTED DOWNLINK DATA OR SIGNALING) to obtain the downlink data/signaling (Downlink Data or Signaling), and sends the decrypted downlink data/signaling (Downlink Data or Signaling) to the ue.

It will be appreciated that the serving base station may decrypt the encrypted downlink data/signaling (ENCRYPTED DOWNLINK DATA OR SIGNALING) using the key corresponding to the encryption algorithm to obtain the downlink data/signaling (Downlink Data or Signaling) issued by the core network.

In other embodiments, the serving base station may send a path switch request message to the core network to switch the downlink to the serving base station before sending the downlink data/signaling. After receiving the path switch response message from the core network, the serving base station transmits downlink data/signaling to the user equipment.

The core network sends the subsequent data/signaling (Subsequent Data or Signaling) to the user equipment S1209.

It will be appreciated that after the first transmission of the downlink data/signaling to the ue, the core network may forward the subsequent data/signaling to the ue in sequence through the anchor base station and the serving base station.

In other embodiments, the core network may also forward subsequent data/signaling directly to the user equipment through the serving base station.

S1210, the anchor base station sends a user equipment context release (UE Context Release) message to the serving base station, the user equipment context release message carrying an RRC release (RRC RELEASE) message.

It will be appreciated that after completion of the MT-SDT service data transmission, the anchor base station may instruct the serving base station to release a portion of its cached user equipment context and instruct termination of the MT-SDT session. The service base station does not need to continuously buffer part of the user equipment context, so that the storage space of the service base station can be saved, and the flexibility of resource scheduling is improved. The MT-SDT service data includes all data issued by the core network during the mobile called (MT), including the downlink data/signaling transmitted for the first time in step S1208 and the subsequent data/signaling in step S1209.

The user equipment context release message is used for indicating the service base station to release part of the cached user equipment context. The RRC release message is used to indicate termination of the MT-SDT session.

In this embodiment, the anchor base station triggers the RRC release message together when triggering the user equipment context release message, so that the number of signaling between the anchor base station and the serving base station can be reduced, thereby reducing MT-SDT service delay.

S1211, after receiving the context release message of the ue, the serving base station sends an RRC release (RRC RELEASE) message to the ue to instruct the ue to enter an RRC inactive state or an idle state.

In this embodiment, the serving base station first releases a part of the cached ue context according to the ue context release message, and then instructs the ue to enter an RRC inactive state or an idle state according to the RRC release message carried by the ue context release message, so as to terminate the MT-SDT session.

S1212, the serving base station sends a user equipment context release complete (UE Context Release Complete) message to the anchor base station to inform the anchor base station that the user equipment has entered the RRC inactive state or idle state.

In other embodiments, the serving base station may not trigger the user equipment context release complete (UE Context Release Complete) message.

It can be appreciated that in this embodiment, in a mobile called (MT) scenario, when the anchor base station determines that the user equipment Context (UE Context) migration is not performed, after the serving base station triggers the retrieval of the user equipment Context request (Retrieve UE Context Request) message, the anchor base station triggers the retrieval of the user equipment Context failure (Retrieve UE Context Failure) message and sends encrypted downlink data/signaling (ENCRYPTED DOWNLINK DATA OR SIGNALING) to the serving base station. After receiving the encrypted downlink data/signaling, the serving base station decrypts the encrypted downlink data/signaling to obtain the downlink data/signaling (Downlink Data or Signaling), and sends the downlink data/signaling to the ue. The core network then sends subsequent data/signaling (Subsequent Data or Signaling) to the user equipment. The anchor base station triggers a user equipment context release (UE Context Release) message, which carries an RRC release (RRC RELEASE) message. After the serving base station acquires the RRC release message from the user equipment context release message, triggering an RRC release (RRC RELEASE) message to instruct the user equipment to enter an RRC inactive state or an idle state. After triggering the RRC release message, the serving base station may trigger a user equipment context release complete (UE Context Release Complete) message to notify the anchor base station that the user equipment has entered an RRC inactive state or idle state.

Example 9

Embodiment 9 differs from embodiment 8 in that after step S1206 in embodiment 8, the anchor base station triggers retrieval of the user equipment context failure (Retrieve UE Context Failure) message and sends encrypted downlink data/signaling (ENCRYPTED DOWNLINK DATA OR SIGNALING) to the serving base station. Wherein the retrieve user equipment context failure message carries an RRC release (RRC RELEASE) message.

Fig. 13 is an information interaction diagram of another data transmission method in a scenario in which an anchor base station does not perform user equipment context migration. Referring to fig. 13, the data transmission method may include the steps of:

S1301, the anchor base station acquires downlink data/signaling from the core network (Downlink Signaling or Data).

S1302, the anchor base station determines whether to perform user equipment Context (UE Context) migration.

The embodiment shown in fig. 13 is described by taking an example in which no context migration of the user equipment is performed.

S1303, the service base station sends a Paging (Paging) message to the user equipment, wherein the Paging message carries first indication information.

S1304, the serving base station sends a Paging (Paging) message to the user equipment.

S1305, after receiving the paging message, the ue sends an RRC recovery request (RRC Resume Request) message to the serving base station, where the RRC recovery request message carries the first indication information.

S1306, after receiving the RRC resume request message, the serving base station sends a request (Retrieve UE Context Request) for retrieving the user equipment context to the anchor base station, where the request for retrieving the user equipment context carries the first indication information and a Downlink Address (Downlink Address).

It is understood that steps S1301 to S1306 are the same as steps S1201 to S1206 in embodiment 8, and are not described here.

S1307, the anchor base station sends a retrieve user equipment context failure (Retrieve UE Context Failure) message carrying an RRC release (RRC RELEASE) message and encrypted downlink data/signaling (ENCRYPTED DOWNLINK DATA OR SIGNALING) to the serving base station.

It will be appreciated that upon informing the serving base station that all user equipment contexts have not been acquired, the anchor base station may collectively instruct termination of the MT-SDT session.

Wherein retrieving the user equipment context failure message is used to inform the serving base station that all user equipment contexts have not been acquired. The RRC release message is used to indicate termination of the MT-SDT session.

In this embodiment, the anchor base station triggers the RRC release message together when triggering the user equipment context retrieval failure, so that the number of signaling between the anchor base station and the serving base station can be reduced, thereby reducing MT-SDT service delay.

S1308, the serving base station decrypts the encrypted downlink data/signaling (ENCRYPTED DOWNLINK DATA OR SIGNALING) to obtain the downlink data/signaling (Downlink Data or Signaling), and sends the downlink data/signaling (Downlink Data or Signaling) to the ue.

It is understood that step S1308 is the same as step S1208 in embodiment 8, and will not be described herein.

S1309, the serving base station sends an RRC release (RRC RELEASE) message to the user equipment to instruct the user equipment to enter an RRC inactive state or idle state.

In this embodiment, after transmitting downlink data/signaling to the ue, the serving base station instructs the ue to enter an RRC inactive state or an idle state according to the RRC release message, thereby terminating the MT-SDT session.

S1310, the serving base station sends a user equipment context release complete (UE Context Release Complete) message to the anchor base station to inform the anchor base station that the user equipment has entered RRC inactive state or idle state.

In other embodiments, the serving base station may not trigger the ue context release complete message.

It can be appreciated that in this embodiment, in the mobile called (MT) scenario, when the anchor base station determines that the user equipment Context (UE Context) migration is not performed, after the serving base station triggers the retrieval of the user equipment Context request (Retrieve UE Context Request) message, the anchor base station triggers the retrieval of the user equipment Context failure (Retrieve UE Context Failure) message, and sends encrypted downlink data/signaling (ENCRYPTED DOWNLINK DATA OR SIGNALING) to the serving base station, the retrieval of the user equipment Context failure message carries the RRC release (RRC RELEASE) message. After receiving the encrypted downlink data/signaling, the serving base station decrypts the encrypted downlink data/signaling to obtain the downlink data/signaling (Downlink Data or Signaling), and sends the downlink data/signaling to the ue. After the serving base station acquires the RRC release message from the retrieve user equipment context failure message, triggering an RRC release (RRC RELEASE) message to instruct the user equipment to enter an RRC inactive state or an idle state. After triggering the RRC release message, the serving base station may trigger a user equipment context release complete (UE Context Release Complete) message to notify the anchor base station that the user equipment has entered an RRC inactive state or idle state.

It should be noted that, in the second scenario, the anchor base station and the serving base station are the same base station, and the "serving base station" and the "anchor base station" in all the method steps in the above embodiment of the first scenario may be replaced by the "network device" or the "base station" to implement the data transmission method in the second scenario.

It can be appreciated that the embodiments of the present application may also be used in other traffic scenarios, such as Extended Reality (XR) and quality of service (Quality of Service, qoS) requirements of traffic such as ultra-reliable low-delay communications (Ultra Reliable Low Latency Communication, URLLC), where the network device may quickly recover the downlink connection and transmit the downlink data/signaling to the user device in time by notifying the user device to receive the downlink data/signaling during the RRC inactive state.

Fig. 14 is a schematic structural diagram of a network device 100 according to an embodiment of the present application.

The network device 100 may be a serving base station, and referring to fig. 14, the network device 100 may include a first memory 110 and a first processor 120, where the first memory 110 is configured to store a computer program or instructions, and the first processor 120 may invoke the computer program or instructions stored in the first memory 110 to perform all method steps of a serving base station side method embodiment in an embodiment of the present application.

Fig. 15 is a schematic structural diagram of a network device 200 according to an embodiment of the present application.

The network device 200 may be an anchor base station, and referring to fig. 15, the network device 200 may include a second memory 210 and a second processor 220, where the second memory 210 is used to store a computer program or instructions, and the second processor 220 may call the computer program or instructions stored on the second memory 210 to perform all the method steps of the anchor base station side method embodiment in the embodiment of the present application.

In some embodiments, the structure of a User Equipment (UE) may be as shown in fig. 16, and the UE may include a processor 1610, an external memory interface 1620, an internal memory 1621, a universal serial bus (universal serial bus, USB) interface 1630, a charge management module 1640, a power management module 1641, a battery 1642, an antenna 1, an antenna 2, a mobile communication module 1650, a wireless communication module 1660, an audio module 1670, a speaker 1670A, a receiver 1670B, a microphone 1670C, an earpiece interface 1670D, a sensor module 1680, keys 1690, a motor 1691, an indicator 1692, a camera 1693, a display 1694, and a user identification module (subscriber identification module, SIM) card interface 1695, etc. The sensor modules 1680 may include, among others, pressure sensors 1680A, gyroscopic sensors 1680B, barometric pressure sensors 1680C, magnetic sensors 1680D, acceleration sensors 1680E, distance sensors 1680F, proximity sensors 1680G, fingerprint sensors 1680H, temperature sensors 1680J, touch sensors 1680K, ambient light sensors 1680L, bone conduction sensors 1680M, and the like.

It is to be understood that the structure illustrated in this embodiment does not constitute a specific limitation on the UE. In other embodiments, the UE may include more or fewer components than shown, or may combine certain components, or split certain components, or a different arrangement of components. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

Processor 1610 may include one or more processing units, for example, processor 1610 may include an application processor (application processor, AP), a Modem, a graphics processor (graphics processing unit, GPU), an image signal processor (IMAGE SIGNAL processor, ISP), a controller, a video codec, a digital signal processor (DIGITAL SIGNAL processor, DSP), a baseband processor, and/or a neural Network Processor (NPU), etc. Wherein the different processing units may be separate devices or may be integrated in one or more processors.

The charge management module 1640 is used to receive charge input from a charger. The charger can be a wireless charger or a wired charger.

The power management module 1641 is used to connect the battery 1642, the charge management module 1640 and the processor 1610. The power management module 1641 receives input from the battery 1642 and/or the charge management module 1640, and provides power to the processor 1610, the internal memory 1671, the display screen 1694, the camera 1693, the wireless communication module 1660, and the like.

The wireless communication functions of the UE may be implemented by antenna 1, antenna 2, mobile communication module 1650, wireless communication module 1660, modem, baseband processor, and the like.

The antennas 1 and 2 are used for transmitting and receiving electromagnetic wave signals. Each antenna in the UE may be used to cover a single or multiple communication bands. Different antennas may also be multiplexed to improve the utilization of the antennas.

The mobile communication module 1650 may provide a solution for wireless communication including 2G/3G/4G/5G, etc., as applied to UEs.

The wireless communication module 1660 may provide solutions for wireless communication including wireless local area network (wireless local area networks, WLAN) such as wireless fidelity (WIRELESS FIDELITY, wi-Fi) network, bluetooth (BT), global navigation satellite system (global navigation SATELLITE SYSTEM, GNSS), frequency modulation (frequency modulation, FM), near field communication (NEAR FIELD communication, NFC), infrared (IR), etc. for application on a UE. The wireless communication module 1660 may be one or more devices that integrate at least one communication processing module. The wireless communication module 1660 receives electromagnetic waves via the antenna 2, modulates the electromagnetic wave signals and filters them, and transmits the processed signals to the processor 1610. The wireless communication module 1660 may also receive signals to be transmitted from the processor 1610, frequency modulate them, amplify them, and convert them to electromagnetic waves for radiation via the antenna 2.

In an embodiment of the present application, the wireless communication module 1660 may be configured to send a request for recovering the RRC connection to the network node by the UE, and receive a response message from the network node.

The UE implements display functionality via the GPU, display screen 1694, and application processor, etc. The GPU is a microprocessor for image processing, and is connected to the display screen 1694 and the application processor.

The display screen 1694 is used to display images, videos, and the like. A series of graphical user interfaces (GRAPHICAL USER INTERFACE, GUIs) may be displayed on the display 1694 of the UE.

The UE may implement shooting functions through the ISP, camera 1693, video codec, GPU, display 1694, and application processor, etc.

Camera 1693 is used to capture still images or video.

The external memory interface 1620 may be used to connect an external memory card, such as a Micro SD card, to enable expansion of the memory capabilities of the UE.

The internal memory 1621 may be used to store computer executable program code including instructions. Processor 1610 executes various functional applications of the UE and data processing by executing instructions stored in internal memory 1621.

The UE may implement audio functionality through an audio module 1670, a speaker 1670A, a receiver 1670B, a microphone 1670C, a headphone interface 1670D, an application processor, and so forth. Such as music playing, recording, etc. The UE may also include pressure sensor 1680A, barometric sensor 1680C, gyroscopic sensor 1680B, magnetic sensor 1680D, acceleration sensor 1680E, distance sensor 1680F, proximity sensor 1680G, ambient light sensor 1680L, fingerprint sensor 1680H, temperature sensor 1680J, touch sensor 1680K, bone conduction sensor 1680M, keys 1690, motor 1691, indicator 1692, and the like.

The SIM card interface 1695 is used to connect to a SIM card. The SIM card may be contacted and separated from the UE by inserting into the SIM card interface 1695 or extracting from the SIM card interface 1695. The UE may support 1 or N SIM card interfaces, N being a positive integer greater than 1. The SIM card interface 1695 may support Nano SIM cards, micro SIM cards, and the like. The same SIM card interface 1695 can insert multiple cards at the same time. The SIM card interface 1695 may also be compatible with external memory cards. The UE interacts with the network through the SIM card to realize the functions of communication, data communication and the like.

Further, operating systems such as a honest operating system, an IOS operating system, an Android operating system, a Windows operating system, and the like are run on the above components. An operating application may be installed on the operating system. In other embodiments, there may be multiple operating systems running within the UE.

It should be understood that the hardware modules included in the UE shown in fig. 16 are only exemplarily described and are not limited to the specific structure of the UE. In fact, the UE provided in the embodiment of the present application may further include other hardware modules having an interaction relationship with the hardware modules illustrated in the figure, which is not limited in detail herein. For example, the UE may also include a flash, a mini-projector, etc. As another example, if the UE is a PC, the UE may further include a keyboard, a mouse, and the like.

It can be understood that the ue shown in fig. 16 may implement all the method steps of the ue-side method embodiment in the embodiment of the present application.

The embodiment of the present application further provides a computer readable storage medium, configured to store a computer program or an instruction, where the computer program or the instruction, when executed by a processor, implement the data transmission method of the embodiment of the present application, and detailed description of the same method steps and beneficial effects are omitted herein.

The embodiments of the present application have been described in detail with reference to the accompanying drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of one of ordinary skill in the art without departing from the spirit of the present application.

Claims

1. A data transmission method, applied to an anchor base station, characterized in that the method comprises:

Acquire downlink data or signaling for a user equipment from a core network, wherein the user equipment is in a radio resource control RRC inactive state, the downlink data or signaling carries first configuration information, and the first configuration information is used to determine whether to perform user equipment context migration; the first configuration information includes auxiliary information, and the auxiliary information is used to perform a small data packet transmission SDT indication for data to be transmitted, and the auxiliary information includes at least one of the following information: subscription data, capabilities, data transmission statistics, data or signaling service characteristics and first indication information related to the SDT of the user equipment; the first indication information is used to indicate triggering mobile terminated small data packet transmission MT-SDT;

Determining whether to perform the user equipment context migration according to the first configuration information;

If it is determined to perform the user equipment context migration, the user equipment context is migrated to the serving base station, and the downlink data or signaling is sent to the serving base station.

2. The data transmission method according to claim 1, wherein the sending the downlink data or signaling to the serving base station comprises:

The downlink data or signaling is sent to the serving base station in a mobile terminated small data packet transmission (MT-SDT) mode.

3. The data transmission method according to claim 1 or 2 is characterized in that the first configuration information also includes at least one of the following information: wireless bearer and data packet size.

4. The data transmission method according to claim 1 or 2, characterized in that:

Before migrating the user equipment context to the serving base station, the method further includes:

receiving a user equipment context retrieval request message from the serving base station, where the user equipment context retrieval request message is used to request a user equipment context;

The migrating the user equipment context to the serving base station includes:

Sending a user equipment context retrieval response message to the serving base station, where the user equipment context retrieval response message carries the user equipment context;

After migrating the user equipment context to the serving base station, the method further includes:

A user equipment context release message is received from the serving base station, and the stored user equipment context is released, wherein the user equipment context release message is used to indicate the release of the stored user equipment context.

5. The data transmission method according to claim 4 is characterized in that the retrieval user equipment context response message also carries at least one of the following information: the data packet size, frequency and auxiliary information allowed to be transmitted, and the auxiliary information is used to perform SDT indication on the data to be transmitted.

6. The data transmission method according to claim 1 or 2, characterized in that:

Sending a paging message to the serving base station, where the paging message carries first indication information; wherein the first indication information is used to indicate triggering the MT-SDT;

7. The data transmission method according to claim 1, characterized in that the method further comprises:

If it is determined not to perform the user equipment context migration, receiving a user equipment context retrieval request message from the serving base station, and sending a user equipment context retrieval failure message and the downlink data or signaling to the serving base station;

The user equipment context retrieval request message is used to request a user equipment context, and the user equipment context retrieval failure message is used to notify the serving base station that all user equipment contexts cannot be acquired.

8. The data transmission method according to claim 1, characterized in that the method further comprises:

If it is determined that the user equipment context migration is not to be performed, sending a user equipment partial context setting request message to the serving base station, wherein the user equipment partial context setting request message carries second configuration information, and the second configuration information is used to configure a data transmission mode in a scenario where the user equipment context migration is not performed;

Send part of the user equipment context and the downlink data or signaling to the serving base station according to the second configuration information.

9 . The data transmission method according to claim 8 , wherein the data transmission mode comprises MT-SDT or SDT.

10. The data transmission method according to claim 8, characterized in that the second configuration information includes a paging message, the partial user equipment context and a protocol data unit of a packet data convergence protocol layer;

The paging message carries second indication information, where the second indication information is used to indicate not triggering MT-SDT;

The protocol data unit of the packet data convergence protocol layer is used to store the downlink data or signaling.

11. A data transmission method, applied to a serving base station, characterized in that the method comprises:

Acquire downlink data or signaling for a user equipment from an anchor base station, wherein the user equipment is in a radio resource control RRC inactive state, the downlink data or signaling carries first configuration information, and the first configuration information is used to determine whether to perform user equipment context migration; the first configuration information includes auxiliary information, and the auxiliary information is used to perform a small data packet transmission SDT indication for data to be transmitted, and the auxiliary information includes at least one of the following information: subscription data, capabilities, data transmission statistics, data or signaling service characteristics and first indication information related to the SDT of the user equipment; the first indication information is used to indicate triggering mobile terminated small data packet transmission MT-SDT;

If the anchor base station determines to perform the user equipment context migration, the user equipment context is received from the anchor base station, and the downlink data or signaling is sent to the user equipment.

12. The data transmission method according to claim 11, wherein the sending the downlink data or signaling to the user equipment comprises:

The downlink data or signaling is sent to the user equipment in MT-SDT mode.

13. The data transmission method according to claim 11 or 12, characterized in that the first configuration information further includes at least one of the following information: wireless bearer and data packet size.

14. The data transmission method according to claim 11 or 12, characterized in that:

Before receiving the user equipment context from the anchor base station, the method further includes:

Sending a user equipment context retrieval request message to the anchor base station, where the user equipment context retrieval request message is used to request the user equipment context;

The receiving a user equipment context from the anchor base station comprises:

receiving a user equipment context retrieval response message from the anchor base station, wherein the user equipment context retrieval response message carries the user equipment context;

After receiving the user equipment context from the anchor base station, the method further includes:

A user equipment context release message is sent to the anchor base station, where the user equipment context release message is used to indicate the release of the stored user equipment context.

15. The data transmission method according to claim 14 is characterized in that the retrieval user equipment context response message also carries at least one of the following information: the data packet size, frequency and auxiliary information allowed to be transmitted, and the auxiliary information is used to perform SDT indication on the data to be transmitted.

16. The data transmission method according to claim 11 or 12, characterized in that:

receiving a paging message from the anchor base station, where the paging message carries first indication information, wherein the first indication information is used to indicate triggering of MT-SDT;

17. The data transmission method according to claim 11, characterized in that the method further comprises:

If the anchor base station determines not to perform the user equipment context migration, sending a user equipment context retrieval request message to the anchor base station, and receiving a user equipment context retrieval failure message and the downlink data or signaling from the anchor base station;

The user equipment context retrieval request message is used to request the user equipment context, and the user equipment context retrieval failure message is used to notify the serving base station that all user equipment contexts cannot be acquired.

18. The data transmission method according to claim 11, characterized in that the method further comprises:

If the anchor base station determines not to perform the user equipment context migration, receiving a user equipment partial context setting request message from the anchor base station, wherein the user equipment partial context setting request message carries second configuration information, and the second configuration information is used to configure a data transmission mode in a scenario where the user equipment context migration is not performed;

Receive part of the user equipment context and the downlink data or signaling from the anchor base station according to the second configuration information, and send the downlink data or signaling to the user equipment.

19. The data transmission method according to claim 18, characterized in that the data transmission mode includes MT-SDT or SDT.

20. The data transmission method according to claim 18, wherein the second configuration information comprises a paging message, the partial user equipment context and a protocol data unit of a packet data convergence protocol layer;

21. The data transmission method according to claim 11 or 12, characterized in that after sending the downlink data or signaling to the user equipment, the method further comprises:

Sending an RRC release message to the user equipment, where the RRC release message is used to instruct the user equipment to enter an RRC inactive state or an idle state; or,

An RRC recovery message is sent to the user equipment, where the RRC recovery message is used to instruct the user equipment to enter an RRC connected state.

22. A network device, characterized in that the network device comprises a memory and a processor, and the processor calls a computer program or code stored in the memory to execute the data transmission method according to any one of claims 1 to 21.

23. A computer-readable storage medium for storing a computer program or an instruction, wherein when the computer program or the instruction is executed by a processor, the data transmission method according to any one of claims 1 to 21 is implemented.