Method, apparatus and system for data transmission, and terminal and network device

Abstract

In an embodiment of the present disclosure, a data transmission method, apparatus, and system, as well as a terminal and a network device, are provided. The solution includes receiving a paging message issued by a target network device according to a first time period when the current state of the target terminal is an inactive state; and, when the received paging message includes a designated paging record for the target terminal, sending a connection resumption request to the target network device, so as to send a downlink small data packet to the target terminal based on the received connection resumption request, where the designated paging record includes a downlink small data transmission in an inactive state indication, and the connection resumption reason in the connection resumption request is a downlink small data transmission in an inactive state. The technical solution of the embodiment of the present disclosure enables downlink data transmission of a terminal in an inactive state, reducing signaling overhead and time delay consumption in the data transmission process.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This disclosure is based on and claims priority to Chinese Patent Application No. 202210986742.0, filed on August 17, 2022, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates to the field of wireless communication technology, and in particular to a method, apparatus and system for data transmission, and a terminal and network device. [Background technology]

[0003] In the related art, a new state, the inactive state (i.e., RRC_INACTIVE state), has been introduced to enable a user equipment (UE) to quickly enter a connected state (RRC_CONNECTED state) for data interaction and to reduce the signaling overhead caused by the UE's mobility and state transition processes. In the RRC_INACTIVE state, the UE's non-access stratum (NAS) remains connected, but the air interface connection corresponding to the UE's access stratum (AS) is temporarily suspended, which is similar to the idle state (i.e., RRC_IDLE state). Summary of the Invention

[0004] The objective of the embodiments of the present disclosure is to provide a data transmission method, apparatus and system, and a terminal and a network device, to realize downlink data transmission of a terminal in an inactive state and reduce signaling overhead and time delay consumption in the data transmission process. Specific technical solutions are as follows:

[0005] An embodiment of the present disclosure provides a data transmission method applied to a target terminal, the method including: receiving a paging message issued by a target network device in accordance with a first time period when a current state of the target terminal is an inactive state; sending a connection resumption request to the target network device when the received paging message includes a designated paging record for the target terminal, such that the target network device sends a downlink small data packet to the target terminal based on the received connection resumption request, where the designated paging record includes a mobile-terminated small data transmission indication and the connection resumption reason in the connection resumption request is mobile-terminated small data transmission; and receiving the downlink small data packet sent by the target network device.

[0006] An embodiment of the present disclosure also provides a data transmission method applied to a target network device, the method including: issuing a paging message to a target terminal in accordance with a second time period, where the target terminal is currently in an inactive state; receiving a connection resumption request sent by the target terminal, where the connection resumption request is sent by the target terminal upon receiving a paging message including a designated paging record of the target terminal itself, where the designated paging record includes a mobile-terminated small data transmission indication, and where the connection resumption reason in the connection resumption request is mobile-terminated small data transmission; and sending a downlink small data packet to the target terminal based on the connection resumption request, so that the target terminal receives the downlink small data packet.

[0007] An embodiment of the present disclosure also provides a data transmission apparatus applicable to a target terminal, the apparatus comprising: a first receiving module for receiving a paging message issued by a target network device in accordance with a first time period when a current state of the target terminal is an inactive state; a first sending module for sending a connection resumption request to the target network device when the received paging message includes a designated paging record of the target terminal, whereby the target network device sends a downlink small data packet to the target terminal based on the received connection resumption request, where the designated paging record includes a mobile-terminated small data transmission indication and the connection resumption reason in the connection resumption request is the mobile-terminated small data transmission; and a second receiving module for receiving the downlink small data packet sent by the target network device.

[0008] In some embodiments, the paging message includes a paging record list, which is a list for recording terminals to be paged, and the paging record list includes at least one paging record.

[0009] In some embodiments, the paging record includes at least one of a terminal identity, an access type, or a mobile-terminated small data transmission indication of the terminal being paged: the terminal identity includes a NAS identity (ID) assigned to the terminal by a Non-Access Stratum (NAS) for core network paging and a fully inactive terminal identity for Radio Access Network (RAN) paging; the access type is used to indicate whether the paging message is a paging message initiated by a Protocol Data Unit (PDU) session not accessed by 3GPP; and further, the mobile-terminated small data transmission indication is used to indicate that the paging message is used to trigger a mobile-terminated small data transmission.

[0010] In some embodiments, the paging record further includes a contention-free access preamble that indicates to the terminal to initiate contention-free random access.

[0011] In some embodiments, the data transmission apparatus further includes: an analysis module for analyzing each paging record in the received paging message after receiving the paging message issued by the target network device according to the first time period; and a first determination module for determining, for each paging record obtained by the analysis, that the paging record is a designated paging record of the target terminal if the completely inactive state terminal identification information in the paging record matches the completely inactive state terminal identification information stored by the target terminal and the paging record includes a mobile terminated small data transmission indication; and target and a second determination module for determining that the paging record is not a designated paging record for the target terminal when it does not match the fully inactive state terminal identification information stored by the terminal and / or when the paging record does not include a mobile terminated small data transmission indication.

[0012] In some embodiments, the first sending module is specifically used to send a connection resumption request to the target network device based on Configured Grant (CG) configuration information when the target terminal stores CG configuration information and the received paging message includes a designated paging record for the target terminal.

[0013] In some embodiments, the first sending module is specifically used for sending a connection resumption request to the target network device in a contention-free access method when the received paging message includes a designated paging record for the target terminal and the designated paging record does not include a contention-free access preamble, if the target terminal does not store configured grant (CG) configuration information; and for sending a connection resumption request to the target network device in a contention-free access method when the received paging message includes a designated paging record for the target terminal and the designated paging record includes a contention-free access preamble.

[0014] In some embodiments, the data transmission apparatus further comprises: a determination module for determining whether the target terminal currently satisfies a preset connection initiation condition before sending a connection resumption request to the target network device, wherein the preset connection initiation condition is that a mobile-terminated small data transmission indication is received, or the preset connection initiation condition is that a mobile-terminated small data transmission indication is received and a downlink Reference Signal Receiving Power (RSRP) is greater than a preset threshold; and an implementation module for performing the step of sending a connection resumption request to the target network device when the target terminal satisfies the preset connection initiation condition.

[0015] In some embodiments, the data transmission apparatus further comprises an implementation module for sending another connection resumption request when another preset connection initiation condition is met such that the target terminal sends uplink data packets to the target network device after the connection corresponding to the another connection resumption request is resumed, wherein the another preset connection initiation condition is that the data volume of a radio bearer configured for Mobile Originated Small Data Transmission is less than a preset data volume threshold, or the another preset connection initiation condition is that the data volume of a radio bearer configured for Mobile Originated Small Data Transmission is less than a preset data volume threshold and uplink small data transmission resources are available.

[0016] In some embodiments, the preset connection initiation condition is that a mobile-terminated small data transmission indication is received; or a mobile-terminated small data transmission indication is received, and Radio resource control ( RRC :Radio Resource Control) The lower layer below the layer, Mobile Terminated This is expressed as indicating that the trigger condition for small data transmission is met.

[0017] In some embodiments, another preset connection initiation condition is 、R R C layer A higher layer requests the resumption of the RRC connection, System Information Block Type 1 ( SIB1 :System Information Block Type 1) includes a common configuration for small data transmission, the small data transmission configuration is configured, all uplink small data is mapped to the radio bearer of the small data transmission configuration, and the lower layers below the RRC layer Mobile Originated This is expressed as indicating that the trigger condition for small data transmission is met.

[0018] In some embodiments, the data transmission device further comprises: a first initiation module that starts a timer for detecting a resumption process of the small data transmission in an inactive state when the target terminal satisfies a preset connection initiation condition; and a second initiation module that starts a timer for monitoring the resumption process in the inactive state and for sending a timeout indication to the MAC entity when the target terminal does not satisfy the preset connection initiation condition, wherein the timeout indication is used to indicate a timeout of a configured grant (CG) timing advance timer in the CG configuration information for the small data transmission.

[0019] In some embodiments, the data transmission apparatus further comprises a release module for releasing the stored configured grant (CG) configuration information when the target terminal moves from a current radio access network (RAN) cell to another RAN cell and initiates a connection resumption process in the other RAN cell.

[0020] In some embodiments, the connection resume request is a first connection resume request or a second connection resume request, and the first sending module is used: to select the first connection resume request as the connection resume request when the SIB1 sent by the base station indicates that the connection resume request uses a full resume identifier, or to select the second connection resume request as the connection resume request when the received SIB1 does not indicate the use of a full resume identifier; to restore preset security information from stored access stratum context information, in particular, the preset security information including a Radio Resource Control (RRC) configuration, a Robust Header Compression (ROHC) state, a stored mapping relationship between Quality of Service (QoS) flows and Data Resource Bearers (DRBs), a base station root key, and an integrity protection key; and the first sending module is further used to restore a Packet Data Convergence Protocol (PDCP) status of the SIB1. It is used, among other things, to reconstruct the Radio Link Control Protocol (RLC) entity; to restore SIB1; for each radio bearer configured for mobile-terminated small data transmission, to resume the configuration associated with the primary cell group of the PDCP configuration and the Radio Link Layer Control Protocol (RLC) bearer from the access stratum context information and to reconstruct the PDCP entity for this radio bearer; to resume all radio bearers configured for mobile-terminated small data transmission; and to send a connection resumption request to the target network device.

[0021] In some embodiments, the first connection resume request and the second connection resume request each include a resume identifier, a resume integrity check code, and a connection resume reason, wherein the resume identifier of the first connection resume request is a full inactive state terminal identity stored by the target terminal, and the resume identifier of the second connection resume request is a shortened inactive state terminal identity stored by the target terminal, wherein the full inactive state terminal identity and the shortened inactive state terminal identity are radio network temporary identifier values ​​of the terminal in the inactive state and are used by the target network side to find the anchor point before the terminal entered the inactive state and the access stratum context information stored by the anchor point, and the full inactive state terminal identity and the shortened inactive state terminal identity have different sizes; and the resume integrity check code is an identity authentication token for terminal identity authentication at the base station.

[0022] In some embodiments, the data transmission apparatus further comprises: a third receiving module for receiving a first release message issued by the target network device when the current state of the target terminal is a connected state, the first release message including suspension configuration information indicating that an inactive state configuration is to be implemented for the terminal; and a first switching module for switching the current state to an inactive state based on the suspension configuration information.

[0023] In some embodiments, the suspension configuration information includes full inactive state terminal identification information, shortened inactive state terminal identification information, radio paging period, radio notification area information, timers, next hop chaining count values, and mobile terminated small data transmission configuration information.

[0024] In some embodiments, the full inactive state terminal identity and the shortened inactive state terminal identity are radio network temporary identifier values ​​of the terminal in the inactive state, and are used by the target network side to find the anchor point node before the terminal entered the inactive state and the access stratum context information stored by the anchor point node, and the full inactive state terminal identity and the shortened inactive state terminal identity have different sizes; the radio paging cycle is a RAN paging cycle configured by a Radio Access Network (RAN) side node for the terminal in the inactive state; the radio notification area information includes a cell list and a radio area configuration list, and the cell list is a RAN area as A list of configured cells. The radio area configuration list is a list of configured cells. The radio area configuration list is a list of configured cells. The list of configured cells ... RA The timer is used to trigger the periodic RAN-based Notification Area Update (RNAU) process in the terminal; the next-hop chaining count value is used to calculate the security key after the connection is resumed; and the configuration information for mobile-terminated small data transmission is Mobile Terminated Data Resource Bearer (DRB) list for small data transmission or Mobile Terminated and at least one of a signaling radio bearer 2 (SRB2) indication of small data transmission; Mobile Terminated The DRB list for small data transmission indicates the DRB identifiers of the small data transmission configuration; Mobile Terminated The SRB2 indication for small data transmission indicates whether or not SRB2 is present in the small data transmission configuration of the terminal.

[0025] In some embodiments, the mobile terminated small data transmission configuration information further includes configured grant (CG) configuration information, Committed loveThe information includes a CG SSB RSRP threshold, a CG timing advance timer, a CG timing advance verification configuration, and a CG RSRP variation threshold, where: the CG SSB RSRP threshold is a reference signal received power (RSRP) threshold selected by an SSB that performs small data transmission based on the CG resource; the CG timing advance timer is used for timing synchronization of the small data transmission; the CG timing advance verification configuration is used for configuring timing advance (TA) verification based on the RSRP; and the CG RSRP variation threshold is an RSRP threshold for TA verification of the small data transmission.

[0026] In some embodiments, the first switching module: resets the media access control (MAC) to release the default MAC cell group configuration; applies suspension configuration information; and, when the suspension configuration information includes CG configuration information, each DRB in the DRB list for small data transmission in an inactive state. Mobile Terminated SRB2 instruction for small data transmission SRB2 in and Mobile TerminatedTo determine the DRB and SRB2 in the process of small data transmission, to reconstruct the Radio Link Layer Control Protocol (RLC) entity for each RLC bearer in the target terminal configuration, to trigger the Packet Data Convergence Protocol (PDCP) entity to perform a Session Data Unit (SDU) discard process for the resumed SRB2 and SRB1, to indicate to the MAC entity to configure CG resources for small data transmission and to start the CG timing advance timer; the current Access Stratum Root Key (KgNB) and Integrity Protection Key (KRRCint) for Radio Resource Control (RRC) signaling, the Robust Header Compression (ROHC) state, the stored mapping rules between Quality of Service (QoS) flows and Data Resource Bearers (DRBs), the Cell Radio Network Temporary Identifier (C-RNTI) used in the source Primary Cell (PCell), the cell identifier and physical cell identifier of the source PCell, and the New Radio Primary Secondary Cell (NR Primary Secondary Cell) It is used, among other things, to store the special cell (SpCell) common configuration in the synchronization reconfiguration message of the PSCell (New Radio Primary Secondary Cell), the parameters in the synchronization reconfiguration message of the PCell, the parameters in the synchronization reconfiguration message of the NR PSCell, the mobility control information of the secondary cell group (SCG) of the E-UTRA PSCell, the primary secondary cell (PSCell) configuration of the EN-DC, and all other configuration parameters except the serving cell common configuration SIB of the access stratum context information of the terminal in the inactive state; to suspend all SRBs except SRB0 and DRBs; to indicate to the lower layers below the RRC layer that PDCP suspension is to be performed for all DRBs; and to switch to the inactive state and perform cell reselection.

[0027] In some embodiments, the data transmission apparatus further comprises a fourth receiving module for receiving a system message broadcast by the target network device, the system message including at least one of downlink transmission frequency information, an initial downlink Bandwidth Part (BWP), Broadcast Control Channel (BCCH) configuration information, or Paging Channel (PCCH) configuration information.

[0028] In some embodiments, the downlink transmission frequency information is used to indicate a transmission frequency of a downlink small data packet; the initial downlink BWP is an initial downlink BWP configuration of the primary cell; the BCCH configuration information is a configuration related to modifying the passing period of system messages; and the PCCH configuration information is a default paging period, a paging frame number and configuration, the number of paging occasions, and a first Physical Downlink Control Channel (PDCCH) configuration. the default paging period is the default paging period broadcast in the system message; the paging frame number and configuration are used to derive the total number of paging frames and the paging frame offset; the number of paging occasions is used to indicate the number of paging occasions in each paging frame; the paging occasions are a group of PDCCH monitoring occasions consisting of multiple time slots for sending paging control information; and the first PDCCH monitoring occasion is the first PDCCH monitoring occasion for indicating that the paging occasions of the paging frame are to be monitored.

[0029] In some embodiments, the data transmission device includes a third determination module for determining, when the target terminal is in an inactive state, a smaller value of a radio paging period and a default paging period as a first time period for receiving paging messages, wherein the radio paging period is a Radio Access Network (RAN) paging period configured by a RAN side node for the terminal in the inactive state.

[0030] In some embodiments, the connection resumption request further includes an uplink small data packet; and the second receiving module is specifically used for receiving the downlink small data packet sent by the target network device and feedback information sent by the target network device for the uplink small data packet.

[0031] In some embodiments, the data transmission apparatus further comprises: a fifth receiving module for receiving a second release message sent by the target network device when transmission of the downlink small data packet is completed, the second release message including instruction information indicating to switch the state; and a second switching module for switching the current state to an inactive state or an idle state based on the instruction information.

[0032] An embodiment of the present disclosure also provides a data transmission apparatus applicable to a target network device, the data transmission apparatus including: a second sending module for issuing a paging message to a target terminal in accordance with a second time period, where the target terminal is currently in an inactive state; a sixth receiving module for receiving a connection resumption request sent by the target terminal, where the connection resumption request is sent by the target terminal upon receiving a paging message including a designated paging record of the target terminal itself, where the designated paging record includes a mobile-terminated small data transmission indication, and where the connection resumption reason in the connection resumption request is mobile-terminated small data transmission; and a third sending module for sending a downlink small data packet to the target terminal based on the connection resumption request, so that the target terminal receives the downlink small data packet.

[0033] In some embodiments, the paging message includes a paging record list, which is a list for recording terminals to be paged, and the paging record list includes at least one paging record.

[0034] In some embodiments, the paging record includes at least one of a terminal identity of the terminal being paged, an access type, or a mobile-terminated small data transmission indication: the terminal identity includes a NAS identity (ID) assigned to the terminal by a non-access stratum (NAS) for core network paging and a fully inactive terminal identity for radio access network (RAN) paging; the access type is used to indicate whether the paging message is a paging message initiated by a protocol data unit (PDU) session that is not accessed by a 3rd Generation Partnership Project (3GPP); and the mobile-terminated small data transmission indication is used to indicate that the paging message is used to trigger a mobile-terminated small data transmission.

[0035] In some embodiments, the paging record further includes a contention-free access preamble that indicates to the terminal to initiate contention-free random access.

[0036] In some embodiments, the connection resume request is a first connection resume request or a second connection resume request, where the first connection resume request is sent by the target terminal when the SIB1 sent by the base station indicates that the connection resume request uses a full resume identifier, and the second connection resume request is sent by the target terminal when the SIB1 sent by the base station does not indicate that the connection resume request uses a full resume identifier.

[0037] In some embodiments, the first connection resume request and the second connection resume request each include a resume identifier, a resume integrity check code, and a connection resume reason, wherein the resume identifier of the first connection resume request is a full inactive state terminal identity stored by the target terminal, and the resume identifier of the second connection resume request is a shortened inactive state terminal identity stored by the target terminal, wherein the full inactive state terminal identity and the shortened inactive state terminal identity are radio network temporary identifier values ​​of the terminal in the inactive state and are used by the target network side to find the anchor point before the terminal entered the inactive state and the access stratum context information stored by the anchor point, and the full inactive state terminal identity and the shortened inactive state terminal identity have different sizes; and the resume integrity check code is an identity authentication token for terminal identity authentication at the base station.

[0038] In some embodiments, the data source sends the first release message target Further comprising a fourth sending module for issuing to the terminal, the first release message including suspension configuration information indicating to the terminal to implement an inactive state configuration, whereby the target terminal switches its current state to an inactive state based on the suspension configuration information.

[0039] In some embodiments, the suspension configuration information includes full inactive state terminal identification information, shortened inactive state terminal identification information, radio paging period, radio notification area information, timers, next hop chaining count values, and mobile terminated small data transmission configuration information.

[0040] In some embodiments, the full inactive state terminal identity and the shortened inactive state terminal identity are radio network temporary identifier values ​​of the terminal in the inactive state, and are used by the target network side to find the anchor point node before the terminal entered the inactive state and the access stratum context information stored by the anchor point node, and the full inactive state terminal identity and the shortened inactive state terminal identity have different sizes; the radio paging cycle is a RAN paging cycle configured by a Radio Access Network (RAN) side node for the terminal in the inactive state; the radio notification area information includes a cell list and a radio area configuration list, and the cell list is a RAN area as A list of configured cells. The radio area configuration list is a list of configured cells. The radio area configuration list is a list of configured cells. The list of configured cells ... RA The timer is used to trigger the periodic RAN-based Notification Area Update (RNAU) process in the terminal; the next-hop chaining count value is used to calculate the security key after the connection is resumed; the mobile-terminated small data transmission configuration information is the inactive small data transmission data resource bearer (DRB) list or Mobile Terminated and a signaling radio bearer 2 (SRB2) indication of small data transmission, wherein the inactive small data transmission DRB list indicates a DRB identifier of the small data transmission configuration; Mobile Terminated The SRB2 indication for small data transmission indicates whether or not SRB2 is present in the small data transmission configuration of the terminal.

[0041] In some embodiments, the mobile terminated small data transmission configuration information further includes configured grant (CG) configuration information, Committed loveThe information includes a CG SSB RSRP threshold, a CG timing advance timer, a CG timing advance verification configuration, and a CG RSRP variation threshold: the CG SSB RSRP threshold is a reference signal received power (RSRP) threshold selected by an SSB that performs small data transmission based on the CG resource; the CG timing advance timer is used for timing synchronization of small data transmission; the CG timing advance verification configuration is used for configuring timing advance (TA) verification based on RSRP; and the CG RSRP variation threshold is an RSRP threshold for TA verification of small data transmission.

[0042] In some embodiments, the data transmission device further comprises a broadcast module for broadcasting a system message, the system message including at least one of downlink transmission frequency information, an initial downlink bandwidth portion (BWP), a broadcast control channel (BCCH) configuration information, or a paging channel (PCCH) configuration information.

[0043] In some embodiments, the downlink transmission frequency information is used to indicate a transmission frequency of a downlink small data packet; the initial downlink BWP is an initial downlink BWP configuration of the primary cell; the BCCH configuration information is a configuration related to modifying a passing period of a system message; the PDCCH configuration information includes a default paging period, a paging frame number and configuration, a number of paging occasions, and a first physical downlink control channel (PDCCH) monitoring occasion, and the default paging period is a default paging period broadcast in a system message. the paging frame number and configuration are used to derive the total number of paging frames and the paging frame offset; the number of paging occasions is used to indicate the number of paging occasions in each paging frame; the paging occasion is a group of PDCCH monitoring occasions consisting of multiple time slots for sending paging control information; and the first PDCCH monitoring occasion is the first PDCCH monitoring occasion to indicate monitoring of the paging occasions of the paging frame.

[0044] In some embodiments, the data sending device further comprises a fourth determining module that determines a default paging period as the second time period for sending the paging message.

[0045] In some embodiments, the connection resumption request further includes an uplink small data packet, and the third sending module is specifically used for: generating feedback information for the uplink small data packet and obtaining the downlink small data packet when receiving the connection resumption request; and sending the downlink small data packet and the feedback information to the target terminal.

[0046] In some embodiments, the data transmission device further comprises a fifth sending module for sending a second release message to the target terminal when transmission of the downlink small data packet is completed, the second release message including instruction information indicating to switch states, whereby the target terminal switches its current state to an inactive state or an idle state based on the instruction information.

[0047] An embodiment of the present disclosure also provides a data transmission system including a target terminal and a target network device, wherein the target terminal is used to implement any of the above-mentioned data transmission methods applied to the target terminal, and the target network device is used to implement any of the above-mentioned data transmission methods applied to the target network device.

[0048] An embodiment of the present disclosure also provides a target terminal including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus, the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory to perform any of the above data transmission methods.

[0049] An embodiment of the present disclosure also provides a target network device including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus, the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory to perform any of the above data transmission methods.

[0050] An embodiment of the present disclosure also provides a computer-readable storage medium having stored thereon a computer program that, when executed by a processor, performs any of the above data transmission methods.

[0051] Embodiments of the present disclosure also provide a computer program product comprising instructions that, when executed on a computer, cause the computer to perform any of the data transmission methods described above.

[0052] The embodiments of the present disclosure have the following beneficial effects:

[0053] According to the technical solution provided in the embodiment of the present disclosure, when the target terminal receives a paging message including a paging record designated by the target network device when the target terminal is in an inactive state, a connection resumption request can be sent to the target network device to trigger a small data transmission process between the target terminal and the target network device when the terminal is in an inactive state. At this time, the target network device can send a downlink small data packet to the target terminal based on the received connection resumption request, and the target terminal also receives the downlink small data packet, thereby realizing the downlink small data packet transmission process of the terminal in an inactive state.

[0054] Furthermore, compared with related technologies in which a terminal in an inactive state must switch to a connected state for data transmission, the embodiment of the present disclosure introduces a new terminal access type, namely, mobile-terminated small data transmission, through a mobile-terminated small data transmission indication in a designated paging record, so that the terminal can receive downlink small data packets sent by a target network device when in an inactive state. The signaling overhead and delay consumption caused by switching from an inactive state to a connected state are avoided, the transmission efficiency of downlink small data packets is improved, and the signaling overhead of downlink small data packets is saved, thereby effectively reducing the signaling overhead and delay consumption in the data transmission process.

[0055] Of course, it is not necessary to simultaneously achieve all of the above advantages by implementing any product or method of the present disclosure.

[0056] In order to more clearly describe the embodiments of the present disclosure or the technical solutions in the prior art, the accompanying drawings that need to be used to describe the embodiments or the prior art are briefly presented below. Of course, the accompanying drawings described below are only a part of the embodiments of the present disclosure. Other embodiments may also be obtained by those skilled in the art through these accompanying drawings. [Brief explanation of the drawings]

[0057] [Figure 1] 1 is a first schematic flowchart of a data transmission method provided by an embodiment of the present disclosure; [Figure 2] 2 is a second schematic flowchart of a data transmission method provided by an embodiment of the present disclosure. [Figure 3] 10 is a third schematic flowchart of a data transmission method provided by an embodiment of the present disclosure. [Figure 4]4 is a fourth schematic flowchart of a data transmission method provided by an embodiment of the present disclosure. [Figure 5] 5 is a fifth schematic flowchart of a data transmission method provided by an embodiment of the present disclosure. [Figure 6] 6 is a sixth schematic flowchart of a data transmission method provided by an embodiment of the present disclosure. [Figure 7] 1 is a schematic flowchart of a method for sending a connection resume request provided by an embodiment of the present disclosure; [Figure 8] 7 is a seventh schematic flowchart of a data transmission method provided by an embodiment of the present disclosure. [Figure 9] 8 is an eighth schematic flowchart of a data transmission method provided by an embodiment of the present disclosure. [Figure 10] 9 is a ninth schematic flowchart of a data transmission method provided by an embodiment of the present disclosure. [Figure 11] 10 is a schematic flowchart of a data transmission method provided by an embodiment of the present disclosure. [Figure 12] 11 is an eleventh schematic flowchart of a data transmission method provided by an embodiment of the present disclosure. [Figure 13] 12 is a schematic flowchart of a data transmission method provided by an embodiment of the present disclosure. [Figure 14] 13 is a schematic flowchart of a data transmission method provided by an embodiment of the present disclosure. [Figure 15] FIG. 1 is a signaling diagram of a process of data transmission in an inactive state provided by an embodiment of the present disclosure. [Figure 16] FIG. 1 is a first schematic structural diagram of a data transmitting device provided by an embodiment of the present disclosure; [Figure 17] FIG. 2 is a second schematic structural diagram of a data transmitting device provided by an embodiment of the present disclosure; [Figure 18] FIG. 1 is a schematic structural diagram illustrating a data transmission system provided by an embodiment of the present disclosure. [Figure 19] FIG. 2 is a schematic structural diagram illustrating a target terminal provided by an embodiment of the present disclosure; [Figure 20] 1 is a schematic structural diagram illustrating a target network device provided by an embodiment of the present disclosure; DETAILED DESCRIPTION OF THE INVENTION

[0058] The technical solutions in the embodiments of the present disclosure are clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. To be precise, the described embodiments are not all embodiments, but only some of the embodiments of the present disclosure. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art based on the present disclosure belong to the protection scope of the present disclosure.

[0059] In the related art, when a UE in RRC_INACTIVE state needs to send a small data packet, the UE must first switch from RRC_INACTIVE state to RRC_CONNECTED state, i.e., the data can be transmitted only after the connection is established in the network control plane and user plane, which causes more signaling overhead and time delay.

[0060] To solve the problems in the related art, an embodiment of the present disclosure provides a data transmission method. As shown in Figure 1, Figure 1 is a first schematic flowchart of the data transmission method provided by the embodiment of the present disclosure. The method shown in Figure 1 is applied to a target terminal and specifically includes the following steps:

[0061] In step S101, when the current state of the target terminal is an inactive state, a paging message issued by a target network device is received according to a first time period.

[0062] In step S102, when the received paging message includes a designated paging record for the target terminal, a connection resumption request is sent to the target network device, whereby the target network device sends downlink small data packets to the target terminal based on the received connection resumption request, the designated paging record includes a mobile-terminated small data transmission indication, and the connection resumption reason in the connection resumption request is mobile-terminated small data transmission.

[0063] In step S103, a downlink small data packet sent by a target network device is received.

[0064] In an embodiment of the present disclosure, the target network device may be a network device such as a base station accessed by a target terminal, and the target terminal may be any terminal (e.g., an electronic device such as a cell phone or a tablet) within a network coverage range corresponding to the target network device. Here, the target network device and the target terminal are not particularly limited. For ease of understanding, the following description will be given by way of example, without limiting the results, assuming that the target terminal is a UE and the target network device is a base station of a core network of 5G (5th Generation Mobile Communication Technology).

[0065] 1, when the target terminal receives a paging message including a paging record designated by the target network device when the target terminal is in an inactive state, a connection resumption request can be sent to the target network device to trigger a small data transmission process between the target terminal and the target network device when the terminal is in an inactive state. At this time, the target network device can send a downlink small data packet to the target terminal based on the received connection resumption request, and the target terminal also receives the downlink small data packet, thereby realizing the downlink small data packet transmission process of the terminal in an inactive state.

[0066] Furthermore, compared with related technologies in which a terminal in an inactive state must switch to a connected state for data transmission, the embodiment of the present disclosure introduces a new terminal access type, namely, mobile-terminated small data transmission, through a mobile-terminated small data transmission indication in a designated paging record, so that the terminal can receive downlink small data packets sent by a target network device when in an inactive state. The signaling overhead and delay consumption caused by switching from an inactive state to a connected state are avoided, the transmission efficiency of downlink small data packets is improved, and the signaling overhead of downlink small data packets is saved, thereby effectively reducing the signaling overhead and delay consumption in the data transmission process.

[0067] The embodiments of the present disclosure are described below by way of specific embodiments.

[0068] In the above step S101, that is, when the current state of the target terminal is an inactive state, a paging message sent by the target network device is received according to a first time period.

[0069] In an embodiment of the present disclosure, during the terminal's data service transmission process, the terminal may be in three states: connected state (i.e., RRC_CONNECTED state), inactive state (i.e., RRC_INACTIVE state), or idle state (i.e., RRC_IDLE state).

[0070] When any terminal accessing the network corresponding to the target network device is in the inactive state, the target network device itself cannot recognize the inactive state, so the target network device will consider the terminal to be in a connected state. The target network device can send a paging message to the target terminal considered to be in a connected state according to a preset time period (recorded as the second time period). Correspondingly, the target terminal can receive the paging message sent by the target network device according to the preset time period (recorded as the first time period).

[0071] In some embodiments, the paging message may include a paging record list, which is a list for recording terminals to be paged, and which includes at least one paging record.

[0072] In some embodiments, for each paging record included in the paging message, the paging record may include at least one of a terminal identity of the paged terminal, an access type, or a mobile-terminated small data transmission indication.

[0073] For example, the paging record may include the terminal identity of the paged terminal, an access type, or a mobile-terminated small data transmission indication. In another example, the paging record may include the terminal identity and access type of the paged terminal, or the terminal identity and mobile-terminated small data transmission indication of the paged terminal, or the access type and mobile-terminated small data transmission indication. In yet another example, the paging record may include the terminal identity, access type, and mobile-terminated small data transmission indication of the paged terminal.

[0074] The terminal identity may include the NAS ID assigned to the terminal by the NAS for core network paging and the full inactive terminal identity (recorded as Full I-RNTI) for RAN paging. The access type above is used to indicate whether the paging message is initiated by a PDU session not accessed by 3GPP. The mobile terminated small data transmission indication is used to indicate that the paging message is used to trigger a mobile terminated small data transmission.

[0075] The Full I-RNTI is the terminal identity of the inactive target terminal. In addition, the access type may include multiple access types. Depending on the access type, the connection resumption reason changes during the process of initiating the RRC connection resumption process by the paged terminal corresponding to the paging record.

[0076] Regarding the access type of the above paging record, the value corresponding to the access type may include the following cases:

[0077] In the first case, when the value corresponding to the access type is 1 (recorded as access type 1), the terminal is indicated to initiate an RRC connection resumption process, and the connection resumption reason is set as Multimedia Priority Service (MPS) priority access.

[0078] In the second case, when the value corresponding to the access type is 2 (recorded as access type 2), the terminal is indicated to initiate an RRC connection resumption process, and the connection resumption reason is set as Modulation Coding Scheme (MCS) priority access.

[0079] In the third case, when the value corresponding to the access type is any integer between 11 and 15 (recorded as access types 11 to 15, respectively), the terminal is indicated to initiate an RRC connection resumption process, and the connection resumption reason is set as high priority access.

[0080] In the fourth case, when the value corresponding to the access type is any integer N, for example between 4 and 10 (recorded as access type N), the terminal is indicated to initiate an RRC connection resumption process, and the connection resumption reason is set as mobile terminated small data transmission.

[0081] In the fifth case, when the value corresponding to the access type is a value other than the values ​​corresponding to the access types in the first to fourth cases above, for example 3, the terminal is indicated to initiate an RRC connection resumption process, and the connection resumption reason is set as downlink access.

[0082] With respect to the first to fifth cases, when the fourth case is satisfied, the paged terminal corresponding to the paging record starts small data transmission in the inactive state process. That is, a step of sending a connection resumption request to the target network device in step S102 is performed. The value corresponding to the access type in the fourth case is preset in the terminal and can be specifically set according to the user's needs, and is not particularly limited here.

[0083] In some embodiments, in addition to the terminal identification information, access type, and mobile-terminated small data transmission indication described above, for each paging record included in the paging message, the paging record may also include a contention-free access preamble that indicates to the terminal to initiate contention-free random access.

[0084] When the paging record includes the contention-free access preamble, it means that the target network device has assigned a contention-free access preamble to the paged terminal corresponding to the paging record. In this case, the terminal can initiate contention-free random access based on the contention-free access preamble. When the paging record does not include the contention-free access preamble, it means that the target network device has not assigned a contention-free access preamble to the paged terminal corresponding to the paging record. In this case, the terminal must initiate contention-free random access. For terminal-initiated contention-free random access and contention-free random access, please refer to the following description and they will not be specifically described here.

[0085] In an embodiment of the present disclosure, in order to reduce the possibility that the paged terminal does not receive the paging message issued by the target network device in time, the second time period may be equal to or greater than the first time period. That is, the time period for the target network device to issue the paging message is equal to or greater than the time period for the target terminal to receive the paging message. Here, the first time period and the second time period are not particularly limited.

[0086] Regarding the above step S102, that is, when the received paging message includes a designated paging record of the target terminal, a connection resumption request is sent to the target network device, whereby the target network device sends downlink small data packets to the target terminal based on the received connection resumption request. The designated paging record includes a mobile-terminated small data transmission indication, and the connection resumption reason in the connection resumption request is mobile-terminated small data transmission.

[0087] In this step, after receiving the paging message sent by the target network device, the target terminal can determine whether the paging message includes a designated paging record for the target terminal itself. If the paging message includes a designated paging record for the target terminal, the designated paging record includes a mobile-terminated small data transmission instruction, and the target terminal can initiate an RRC connection resumption process, i.e., a mobile-terminated small data transmission process. At this time, the target terminal can send a connection resumption request, i.e., an RRC connection resumption request, to the target network device. For information on determining the designated paging record, please refer to the description below and will not be specifically described here.

[0088] In an embodiment of the present disclosure, the connection resumption request records a connection resumption reason. Depending on the different access types in the paging record, the reason for sending the connection resumption request when the terminal initiates the RRC connection resumption process also varies. For example, in step S102, the target terminal initiates a mobile terminated small data transmission process. Therefore, the connection resumption reason is a downlink (small) data transmission in an inactive state, i.e., a mobile terminated small data transmission (MT-SDT). When the target network device receives the connection resumption request, it may determine to trigger the mobile terminated small data transmission process according to the connection resumption reason recorded in the connection resumption request. At this time, the target network device can send downlink data to the target terminal in the form of a downlink small data packet.

[0089] In some embodiments, when the amount of downlink data is less than a first data amount threshold, the target network device may send the downlink data to the target terminal as one downlink small data packet.

[0090] In another embodiment, when the amount of the downlink data exceeds the first data amount threshold, the target network device can divide the downlink data into a plurality of downlink small data packets, each of which has an amount equal to or less than the first data amount threshold, and send each of the resulting downlink small data packets to the target terminal.

[0091] In an embodiment of the present disclosure, the data transmission between the target terminal in an inactive state and the target network device is in an inactive state MT-SDT, and therefore the data volume of the downlink small data packet sent by the target network device to the target terminal each time is equal to or less than a first data volume threshold. The first data volume threshold can be set according to user needs, channel bandwidth, channel bearing capacity, etc. Here, the first data volume threshold is not particularly limited.

[0092] According to different amounts of the downlink data, the number of downlink small data packets sent by the target network device to the target terminal may be one or more, where the number of the downlink small data packets is not particularly limited.

[0093] In some embodiments, when the received paging message does not include the target terminal's designated paging record, the target terminal can determine that it is not the terminal paged by the target network device. In this case, the target terminal does not perform any processing, i.e., the target terminal does not send a connection resumption request with a connection resumption reason of mobile-terminated small data transmission to the target network device.

[0094] As regards step S103 above, that is, a downlink small data packet sent by the target network device is received.

[0095] In this step, after the target network device sends the downlink small data packet to the target terminal, the target terminal receives the downlink small data packet. According to different amounts of the downlink data, the number of downlink small data packets received by the target terminal also varies. Here, the step of receiving the downlink small data packet by the target terminal is not particularly described here.

[0096] In some embodiments, according to the above method shown in Figure 1, the embodiment of the present disclosure also provides a data transmission method. As shown in Figure 2, Figure 2 is a second schematic flowchart of the data transmission method provided by the embodiment of the present disclosure. The method includes the following steps:

[0097] In step S201, when a current state of the target terminal is an inactive state, a paging message issued by a target network device is received according to a first time period.

[0098] The above step S201 is the same as the above step S101.

[0099] In step S202, each paging record in the received paging message is parsed.

[0100] In this step, for each paging record in the received paging message, the target terminal can analyze the information contained in this paging record to determine information such as terminal identification information or access type contained in this paging record.

[0101] In the embodiment of the present disclosure, the information parsed by the target terminal also varies according to different information contained in each paging record, where the parsed information in each paging record is not particularly limited.

[0102] In step S203, for each analyzed paging record obtained by the analysis, if the completely inactive state terminal identification information in this paging record matches the completely inactive state terminal identification information stored by the target terminal and this paging record includes a mobile terminated small data transmission instruction, it is determined that this paging record is the designated paging record of the target terminal.

[0103] In an embodiment of the present disclosure, the target terminal may store fully inactive state terminal identification information corresponding to the target terminal. For each analyzed paging record obtained by analysis, the target terminal may match the fully inactive state terminal identification information analyzed for this paging record (i.e., the Full I-RNTI in the above paging record) with its stored fully inactive state terminal identification information, determine whether the analyzed information for this paging record includes a mobile-terminated small data transmission indication, and determine whether this paging record is a designated paging record for the target terminal according to the matching result and the determination result. The fully inactive state terminal identification information stored in the target terminal may refer to the description below and will not be specifically described here.

[0104] The above match results and determination results include at least the following cases.

[0105] In the first case, the fully inactive state terminal identification information in the paging record is the same as the fully inactive state terminal identification information stored by the target terminal, and the information parsed from the paging record includes a mobile terminated small data transmission instruction.

[0106] In the second case, the fully inactive state terminal identification information in the paging record is the same as the fully inactive state terminal identification information stored by the target terminal, but the information parsed from the paging record does not include a mobile terminated small data transmission indication.

[0107] In the third case, the fully inactive state terminal identification information in the paging record is different from the fully inactive state terminal identification information stored by the target terminal, but the information parsed from the paging record includes a mobile terminated small data transmission instruction.

[0108] In a fourth case, the fully inactive state terminal identification information in the paging record is different from the fully inactive state terminal identification information stored by the target terminal, and the information parsed from the paging record does not include a mobile terminated small data transmission indication.

[0109] Regarding the above four cases, when the first case above is satisfied, the target terminal can determine the paging record as its own designated paging record.

[0110] In step S204, the complete inactive state terminal identification information in this paging record is target If there is no match with the complete inactive state terminal identification information stored by the terminal and / or if the paging record does not include a mobile terminated small data transmission indication, it is determined that this paging record is not the designated paging record for the target terminal.

[0111] Regarding the four cases shown in step S203 above, when any of the second, third, or fourth cases above is met, the target terminal can determine that this paging record is not the target terminal's own designated paging record.

[0112] For a paging message received by a target terminal, if it is determined that each paging record in the paging message is not a designated paging record for the target terminal itself, the target terminal can determine that the paging message does not include a designated paging record for the target terminal itself.

[0113] In the embodiment of the present disclosure, the target terminal performs step S203 or step S204 in accordance with different cases where there is a match between the completely inactive state terminal identification information in each paging record in the paging message and the completely inactive state terminal identification information stored by the target terminal, and in accordance with different cases where each paging record includes a mobile-terminated small data transmission instruction, where the execution of steps S203 and S204 is not particularly limited.

[0114] In some embodiments, when the paging record in the paging message satisfies the second of the four cases in step S203, i.e., when the fully inactive state terminal identity in the paging record is the same as the fully inactive state terminal identity stored by the target terminal, but the information parsed from the paging record does not include a mobile-terminated small data transmission indication, the target terminal can determine that it is the terminal paged by the target network device. In this case, the target terminal can initiate an RRC connection resumption process according to the value corresponding to the access type in the paging message by the method shown in the first, second, third, or fifth of the five cases shown in step S101. The resumption reason in the connection resumption request matches the value corresponding to the access type, which is not specifically described here.

[0115] In another embodiment, if the paging record in the paging message satisfies the third or fourth case among the four cases in step S203, the completely inactive state terminal identification information in the paging record is different from the completely inactive state terminal identification information stored by the target terminal, so the target terminal can determine that it is not the terminal paged by the target network device. In this case, the target terminal does not need to perform any processing.

[0116] Through the above steps S202 to S204, the target terminal can accurately determine whether the received paging message includes the designated paging record of the target terminal itself, and start the mobile-terminated small data transmission process when the paging message includes the designated paging record, thereby ensuring the start of the downlink small data transmission process of the target terminal.

[0117] In step S205, when the received paging message includes a designated paging record for the target terminal, a connection resumption request is sent to the target network device, whereby the target network device sends downlink small data packets to the target terminal based on the received connection resumption request, the designated paging record includes a mobile-terminated small data transmission indication, and the connection resumption reason in the connection resumption request is mobile-terminated small data transmission.

[0118] In step S206, a downlink small data packet sent by the target network device is received.

[0119] The above steps S205 and S206 are the same as the above steps S102 and S103.

[0120] In some embodiments, the target terminal may store CG configuration information of the target terminal, where the CG configuration information is configured grant resources configured for small data transmission. The CG configuration information stored in the target terminal may refer to the description below and will not be specifically described here.

[0121] In an embodiment of the present disclosure, the above CG configuration information can be used for configured grant resource configuration during an uplink small data transmission process between a target terminal and a target network device, and can also be used for configured grant resource configuration during a downlink small data transmission process between a target terminal and a target network device.

[0122] In some embodiments, when the target terminal stores the CG configuration information according to the above method shown in Figure 1, the embodiment of the present disclosure also provides a data transmission method. As shown in Figure 3, Figure 3 is a third schematic flowchart of the data transmission method provided by the embodiment of the present disclosure. In the method shown in Figure 3, the above step S102 is refined into the following step, namely, step S1021.

[0123] In step S1021, when the received paging message includes a designated paging record of the target terminal, a connection resumption request is sent to the target network device based on the CG configuration information.

[0124] In this step, since the target terminal stores the CG configuration information, the target terminal can start small data transmission in the inactive state process by the configured grant method based on the CG configuration information stored in the target terminal. That is, the target terminal can configure the SDT based on the CG configuration information to configure small data transmission for the initial BWP of the target terminal, or configure small data transmission for the normal uplink (NUL) carrier and supplementary uplink (SUL) carrier of the target terminal.

[0125] In some embodiments, with respect to the CG configuration information stored by the target terminal, when the target terminal moves from the current RAN cell to another RAN cell and initiates a connection resumption process in the other RAN cell, the stored CG configuration information is released. That is, the SDT resources configured by the target terminal based on the CG configuration information are valid only in the cell where the target terminal receives an RRC release message (recorded as the first release message) and transitions to the RRC inactive state. Regarding receiving the first release message, reference may be made to the following description and will not be specifically described here.

[0126] For ease of understanding, the RAN cell where the target terminal is currently located is taken as cell A. At a certain moment, when the target terminal accesses another RAN cell, for example, cell B, as the user moves, the Configured Grant (CG) configuration information received and stored by the target terminal in cell A is not used to initiate the connection resumption process in cell B. The above cell is an abbreviation for base station cell (sometimes referred to as cellular cell).

[0127] Through the above step S1021, the target terminal can start small data transmission in the inactive state process in the CG configured grant method based on the CG configuration information stored in the target terminal.

[0128] In some embodiments, when the target terminal does not store the above CG configuration information, the embodiment of the present disclosure also provides a data transmission method according to the above method shown in Figure 2. As shown in Figure 4, Figure 4 is a fourth schematic flowchart of the data transmission method provided by the embodiment of the present disclosure. In the method shown in Figure 4, the above step S102 is refined into the following steps, namely, steps S1022 to S1023.

[0129] In step S1022, when the received paging message includes a designated paging record for the target terminal and the designated paging record does not include a contention-free access preamble, a connection resumption request is sent to the target network device using a contention access method.

[0130] In step S1023, when the received paging message includes a designated paging record for the target terminal and the designated paging record includes a contention-free access preamble, a connection resumption request is sent to the target network device in a contention-free access manner.

[0131] In an embodiment of the present disclosure, since the target terminal does not store the CG configuration information, the target terminal cannot start small data transmission in the inactive state process using the CG configured grant method. In this case, the target terminal can start small data transmission in the inactive state process using the random access method.

[0132] When the received paging message includes a designated paging record for the target terminal, the designated paging record may or may not include the contention-free access preamble described above.

[0133] In some embodiments, if the designated paging record does not include the contention-free access preamble, the target terminal performs step S1022, i.e., the target terminal can start small data transmission in the inactive state process using the contention access method.

[0134] In another embodiment, when the designated paging record includes the contention-free access preamble, the target terminal performs step S1023, i.e., starts small data transmission in the inactive state process using a contention-free access method based on the contention-free access preamble in the designated paging record. Specifically, the target terminal can send the contention-free access preamble to the target network device. In response to the received contention-free access preamble, the target network device feeds back a random access response message to the target terminal. At this time, the target terminal receives the random access response message. The target terminal can acquire uplink synchronization according to the timing synchronization information in the random access response message and send a connection resumption request according to the uplink resources allocated by the target network device.

[0135] In the above steps S1022 and S1023, a Random Access Channel (RACH) based SDT may be configured for the initial BWP of the terminal, and the RACH based SDT may also be configured for the NUL carrier and SUL carrier of the terminal.

[0136] With respect to the above RACH-based SDT process, the target terminal receives two-step RACH resources and / or four-step RACH resources sent by the target network device for SDT transmission.

[0137] In the embodiment of the present disclosure, the above steps S1022 and S1023 are respectively performed depending on whether the designated paging record includes a contention-free access preamble, and the execution of the above steps S1022 and S1023 is not particularly limited.

[0138] According to the above steps S1022 and S1023, if the target terminal does not store CG configuration information, for example, if the target terminal moves from a specific RAN cell to another RAN cell, small data transmission in the inactive state process can be initiated using different contention access methods and contention-free access methods depending on the presence or absence of a contention-free access preamble in the designated paging record, thereby effectively improving the adaptability of small data transmission in the inactive state.

[0139] In some embodiments, the priority of the small data transmission in the inactive state initiated based on the CG configuration information may be higher than the priority of the small data transmission in the inactive state initiated by the random access method, i.e., if the target terminal stores the CG configuration information, the target terminal may preferentially use the method shown in step S1021 to send a connection resumption request to the target network device, regardless of whether the designated paging record includes the contention-free access preamble.

[0140] In some embodiments, before a connection resumption request is sent to the target network device, it is determined whether the target terminal currently satisfies a preset connection initiation condition.

[0141] Here, the preset connection initiation conditions include receiving a mobile-terminated small data transmission indication, or receiving a mobile-terminated small data transmission indication and a downlink reference signal received power (RSRP) greater than a preset threshold.

[0142] In some embodiments, the preset connection initiation condition is set when a mobile terminated small data transmission indication is received, or when a mobile terminated small data transmission indication is received and a lower layer below the RRC layer: Mobile Terminated This indicates that the trigger conditions for small data transmission are met.

[0143] In some embodiments, if another preset connection initiation condition is met, another connection resume request is sent such that the target terminal sends uplink data packets to the target network device after the connection corresponding to the another connection resume request is resumed. Originated The data volume of the radio bearer configured for small data transmission is less than the preset data volume threshold, or the data volume of the radio bearer configured for mobile-origin small data transmission is less than the preset data volume threshold, and uplink small data transmission resources are available.

[0144] In some embodiments, the above-mentioned another preset connection initiation condition also includes a situation where a higher layer above a Radio Resource Control (RRC) layer requests a resumption of an RRC connection, a System Information Block Type 1 (SIB1) includes a common configuration for small data transmission, the small data transmission configuration is configured, all uplink small data is mapped to radio bearers of the small data transmission configuration, and a lower layer below the RRC layer: Mobile Originated This can also be expressed as indicating that the trigger condition for small data transmission is met.

[0145] Here, the preset connection initiation condition and the other preset connection initiation condition are not particularly limited. The preset data volume threshold and the preset threshold may be set according to user needs, wireless network capacity, etc., and are not particularly limited here.

[0146] In some embodiments, according to the above method shown in Figure 1, the embodiments of the present disclosure also provide a data transmission method. As shown in Figure 5, Figure 5 is a fifth schematic flowchart of the data transmission method provided by the embodiments of the present disclosure. The method includes the following steps:

[0147] In step S501, when the current state of the target terminal is an inactive state, a paging message issued by a target network device is received according to a first time period.

[0148] The above step S501 is the same as the above step S101.

[0149] In step S502, when the received paging message includes a paging record designated for the target terminal, it is determined whether the target terminal currently satisfies a preset connection initiation condition. The preset connection initiation condition is that a mobile-terminated small data transmission indication is received; or that a mobile-terminated small data transmission indication is received and the downlink RSRP is greater than a preset threshold. In this step, when the paging message received by the target terminal includes a paging record designated for the target terminal itself, the target terminal can determine whether the target terminal itself satisfies the preset connection initiation condition. If the preset initiation condition is met, step S503 is performed.

[0150] The lower layer below the RRC layer may be a Medium Access Control (MAC) layer, a Physical (PHY) layer, etc. The upper layer above the RRC layer may be any layer above the RRC layer. Here, the upper layer and lower layer are not particularly limited.

[0151] In step S503, when the target terminal satisfies the preset connection initiation condition, a connection resumption request is sent to the target network device, whereby the target network device sends a downlink small data packet to the target terminal based on the received connection resumption request. The designated paging record includes a mobile-terminated small data transmission indication, and the connection resumption reason in the connection resumption request is mobile-terminated small data transmission.

[0152] In this step, when the target terminal satisfies the above preset connection initiation condition, the target terminal can send a connection resumption request to the target network device, which may be specifically referred to in the above step S102 for sending the connection resumption request, which will not be described further herein.

[0153] In some embodiments, when the target terminal does not satisfy the above preset connection initiation conditions, the target terminal may not perform any processing, i.e., the above step of sending a connection resumption request is not performed.

[0154] By determining the above preset connection initiation conditions, it is possible to ensure that the target terminal meets the initiation conditions for small data transmission in an inactive state, thereby ensuring the success of the small data transmission process in an inactive state between the target terminal and the target network device.

[0155] In step S504, a downlink small data packet sent by a target network device is received.

[0156] The above step S504 is the same as the above step S103.

[0157] In some embodiments, according to the above method shown in Figure 5, the embodiment of the present disclosure also provides a data transmission method. As shown in Figure 6, Figure 6 is a sixth schematic flowchart of the data transmission method provided by the embodiment of the present disclosure. The method includes the following steps:

[0158] In step S601, when the current state of the target terminal is an inactive state, a paging message sent by a target network device is received according to a first time period.

[0159] In step S602, when the received paging message includes a designated paging record of the target terminal, it is determined whether the target terminal currently satisfies the preset connection initiation condition. 。

[0160] In step S603, when the target terminal satisfies the preset connection initiation condition, a connection resumption request is sent to the target network device, whereby the target network device sends downlink small data packets to the target terminal based on the received connection resumption request. The designated paging record includes a mobile-terminated small data transmission indication, and the connection resumption reason in the connection resumption request is mobile-terminated small data transmission.

[0161] The above steps S601 to S603 are the same as the above steps S501 to S503.

[0162] In step S604, when the target terminal satisfies the preset connection start condition, in the inactive state resume process, Can Small Data Transmission Whether it failed or not of MonitoringA timer is started to

[0163] The above step S603 and the above step S604 are both performed when the target terminal satisfies the preset connection initiation condition, where the order in which the above step S603 and the above step S604 are performed is not particularly limited.

[0164] In step S605, a downlink small data packet sent by a target network device is received.

[0165] The above step S605 is the same as the above step S504.

[0166] In step S606, if the target terminal does not satisfy the preset connection start condition, connection A timer to monitor the restart process is started and a timeout indication is sent to the MAC entity. The timeout indication is sent in response to the CG timing advance timer in the CG configuration information for small data transmission. Stop Used to indicate

[0167] According to the above steps S604 and S606, when the preset connection start condition is met, the target terminal can start a timer for detecting the inactive transmission resume process to ensure that no timeout occurs during the inactive transmission resume process, and when the preset connection start condition is not met, the target terminal can start a timer for monitoring the inactive resume process to ensure the inactive resume process.

[0168] In some embodiments, the connection resumption request is a first connection resumption request or a second connection resumption request.

[0169] The first connection resumption request and the second connection resumption request each include a resumption identifier, a resumption integrity check code, and a connection resumption reason.

[0170] The resumption identifier of the first connection resumption request is the full inactive state terminal identity stored by the target terminal, and the resumption identifier of the second connection resumption request is the shortened inactive state terminal identity stored by the target terminal. The resumption integrity check code is an identity authentication token for terminal identity authentication in the base station. The full inactive state terminal identity and the shortened inactive state terminal identity are radio network temporary identifier values ​​of the terminal in the inactive state and are used by the target network side to find the anchor point before the terminal entered the inactive state and the access stratum context information stored by the anchor point. The full inactive state terminal identity and the shortened inactive state terminal identity have different sizes.

[0171] In some embodiments, according to the above method shown in Figure 1, the embodiment of the present disclosure also provides a connection resume request sending method. As shown in Figure 7, Figure 7 is a schematic flowchart of the connection resume request sending method provided by the embodiment of the present disclosure. The method includes the following steps:

[0172] In step S701, when the SIB1 sent by the base station indicates that the connection resume request uses a full resume identifier, the first connection resume request is selected as the connection resume request, or when the received SIB1 does not indicate that the connection resume request uses a full resume identifier, the second connection resume request is selected as the connection resume request.

[0173] In this step, the base station of the core network can send SIB1 to the target terminal, which receives the SIB1. The SIB1 includes information indicating the resumption identifier to be used for the connection resumption request.

[0174] In some embodiments, if the received SIB1 indicates that the resumption identifier in the connection resume request uses a full resumption identifier, the target terminal may determine that the resumption identifier in the connection resume request is a full inactive state terminal identity stored by the target terminal, and may select the first connection resume request as the connection resume request.

[0175] In another embodiment, when the received SIB1 does not indicate that the resumption identifier in the connection resume request uses the full resumption identifier, the target terminal can determine that the resumption identifier in the connection resume request is a shortened inactive state terminal identity (recorded as Short I-RNTI) stored by the target terminal, and can select the second connection resume request as the connection resume request.

[0176] In step S702, preset security information is restored from the stored access stratum context information, including RRC configuration, ROHC state, stored mapping relationships between QoS flows and DRBs, base station root keys, and integrity protection keys.

[0177] In an embodiment of the present disclosure, the above access stratum context information can be stored in an anchor point. The anchor point reserves the UE context information and an NG connection between the UE-related Access and Mobility Management Function (AMF) and User Plane Function (UPF) for the final serving base station (gNB). The NG is a logical interface between the radio access network and the core network.

[0178] In step S703, the PDCP entity is reconstructed for SIB1.

[0179] In step S704, SIB1 is restored.

[0180] In step S705, for each radio bearer configured for mobile terminated small data transmission, the primary cell group of the PDCP configuration and the configuration associated with the RLC bearer are recovered from the access stratum context information and a PDCP entity is re-established for this radio bearer.

[0181] In step S706, all radio bearers configured for mobile terminated small data transmission are resumed.

[0182] In step S707, a connection resumption request is sent to the target network device.

[0183] The above steps S701 to S707 are refinements of the step of sending a connection resumption request to the target network device in the above step S102.

[0184] In some embodiments, according to the above method shown in Figure 1, the embodiment of the present disclosure also provides a data transmission method. As shown in Figure 8, Figure 8 is a seventh schematic flowchart of the data transmission method provided by the embodiment of the present disclosure. The method includes the following steps:

[0185] In step S801, when the current state of the target terminal is a connected state, a first release message issued by the target network device is received, the first release message including suspension configuration information indicating that the terminal is to be configured to be in an inactive state.

[0186] In an embodiment of the present disclosure, in addition to being in an inactive state, the target terminal may also be in a connected state and an idle state. When the target terminal is in a connected state, the target network device may send an RRC release message (recorded as a first release message) to the target terminal. At this time, the target terminal receives the first release message.

[0187] In some embodiments, the first release message may include suspension configuration information, which is used to indicate to the terminal that an inactive state configuration is to be implemented.

[0188] The suspension configuration information may include full inactive state terminal identification information (i.e., the above-mentioned Full I-RNTI), shortened inactive state terminal identification information (i.e., the above-mentioned Short I-RNTI), radio paging period, radio (RAN) notification area information, timer, next hop chaining count value, and mobile terminated small data transmission configuration information.

[0189] In some embodiments, the above-mentioned full inactive state terminal identity information and shortened inactive state terminal identity information are radio network temporary identifier values ​​of a terminal in an inactive state, and are used by a target network side to find an anchor point node before the terminal entered the inactive state and access stratum context information stored by the anchor point node. The full inactive state terminal identity information and the shortened inactive state terminal identity information have different sizes. For example, the size of the full inactive state terminal identity information may be 40 bits, and the size of the shortened inactive state terminal identity information may be 24 bits. Here, the sizes of the full inactive state terminal identity information and the shortened inactive state terminal identity information are not particularly limited.

[0190] The radio paging cycle is a RAN paging cycle configured by a RAN side node (e.g., a base station) for an inactive terminal. The radio paging cycle may be 32 radio frames, 64 radio frames, 128 radio frames, 256 radio frames, etc. Here, the radio paging cycle is not particularly limited.

[0191] The Radio (RAN) notification area information includes a list of cells configured as a RAN area and the RAN area code or RA The wireless area configuration list may include a wireless area code (i.e., a wireless area configuration list).

[0192] The above timer is used to trigger the periodic RNAU process in the terminal.

[0193] The above next-hop chaining count value is used to calculate the security key after the connection is resumed.

[0194] The above mobile terminated small data transmission configuration information is Mobile Terminated DRB list for small data transmission or Mobile Terminated Includes at least one of the SRB2 indications for small data transmission. Mobile Terminated The DRB list for small data transmission indicates the DRB identifiers of the small data transmission configuration, Mobile Terminated The SRB2 indication for small data transmission is used to indicate the presence or absence of SRB2 in the small data transmission configuration of the terminal. SRB stands for signaling radio bearer. For example, the configuration information for mobile terminated small data transmission is: Mobile Terminated DRB list for small data transmission or Mobile Terminated In another example, the configuration information for mobile-terminated small data transmission includes an SRB2 indication of small data transmission. Mobile Terminated DRB list for small data transmission and Mobile Terminated Includes SRB2 instructions for sending small data.

[0195] Inactive Mobile TerminatedIn the above DRB list for small data transmission, if the sequence size is 0, the target terminal can determine that the network has not configured a DRB for small data transmission.

[0196] In some embodiments, the above configuration information for mobile terminated small data transmission may further include CG configuration information. Committed love The information includes the CG SSB RSRP threshold, the CG timing advance timer, the CG timing advance verification configuration, and the CG RSRP variation threshold.

[0197] The above CG SSB RSRP thresholds are used to implement small data transmission based on CG resources. SSB (Synchronization Signal and PBCH block) The CG timing advance timer above is used for timing synchronization of small data transmissions. The CG timing advance verification configuration is used for configuring TA verification based on RSRP. The CG RSRP variation threshold above is the RSRP threshold for TA verification of small data transmissions.

[0198] In some embodiments, when the above CG timing advance verification configuration is not configured in the above CG configuration information, the target terminal does not perform the process of TA verification based on RSRP.

[0199] In an embodiment of the present disclosure, when a network redirects a terminal to a carrier frequency between radio access technologies (RATs) or configures a Dual Active Protocol Stack (DAPS) bearer for the terminal, the network does not configure suspension configuration information for the terminal, i.e., the first release message does not include the suspension configuration information.

[0200] In some embodiments, after receiving the suspension configuration information, the target terminal may store the suspension configuration information. For example, the target terminal may store the Full I-RNTI and Short I-RNTI. Depending on the stored Full I-RNTI and Short I-RNTI, the designated paging record may be queried, and a first connection resumption request / second connection resumption request may be sent.

[0201] In step S802, the current state is switched to an inactive state based on the suspension configuration information.

[0202] In an embodiment of the present disclosure, after receiving the above-mentioned first release message, the target terminal performs the following steps based on the first release message to switch the current state of the target terminal from a connected state to an inactive state:

[0203] In the first step, the MAC is reset and the default MAC cell group configuration is released.

[0204] In the second step, the suspension configuration information is applied.

[0205] In the third step, when the CG configuration information is included in the suspension configuration information, Mobile Terminated Each DRB in the DRB list for small data transmission and Mobile Terminated SRB2 instruction for small data transmission SRB2 shown in but, Mobile Terminated The DRB and SRB2 in the process of small data transmission are determined; the RLC entity is re-established for each RLC bearer in the target terminal configuration; the PDCP entity is triggered to perform the SDU discard process for the resumed SRB2 and SRB1; the small data transmission CG resource is configured for the MAC entity and is indicated to start the CG timing advance timer.

[0206] In a fourth step, the current access stratum root key (KgNB) and RRC signaling integrity protection key (KRRCint), the ROHC state, the stored mapping rules between QoS flows and data resource bearers (DRBs), the C-RNTI used in the source PCell, the cell identifier, the physical cell identifier of the source PCell, the SpCell common configuration in the NR PSCell synchronization reconfiguration message, the parameters of the PCell synchronization reconfiguration message, the parameters of the NR PSCell synchronization reconfiguration message, the mobility control information of the SCG of the E-UTRA PSCell, the PSCell configuration of the EN-DC and all other configuration parameters other than the serving cell common configuration SIB are stored in the access stratum context information of the inactive terminal.

[0207] The above SpCell is the set of the above Pcell and PSCell, and can be expressed as SpCell = Pcell + PSCell. EN-DC is Universal Terrestrial Radio Access (E-UTRA) NR dual connectivity between a Master Cell Group (MCG) using E-UTRA and an SCG using New Radio (NR).

[0208] In the above fourth step, the above SpCell common configuration included in the synchronous reconfiguration message of the NR PSCell, as well as the parameters in the synchronous reconfiguration message of the PCell, the parameters in the synchronous reconfiguration message of the NR PSCell, and other configuration parameters other than the mobility control information of the SCG of the E-UTRA PSCell are all processed according to the configuration conditions in the above CG configuration, which will not be specifically described here.

[0209] In the fifth step, all SRBs except SRB0 and DRB are suspended.

[0210] In the sixth step, all DRB lower layers are instructed to implement PDCP suspension, and the lower layers are placed below the RRC layer.

[0211] In the seventh step, the inactive state is switched off and cell reselection is performed.

[0212] In the seventh step above, the target terminal can perform cell reselection according to the steps of relevant standards, such as TS38.304. Here, the cell reselection process is not specifically described.

[0213] Through the above steps S801 to S802, the target terminal can switch its current state from a connected state to an inactive state according to the received first release message, thereby facilitating the target terminal to quickly enter the inactive state from the connected state, and also facilitating the process of small data transmission in the inactive state when the target terminal's designated paging record is later received, thereby reducing signaling overhead and delay consumption during the data transmission process.

[0214] In step S803, a system message broadcast by a target network device is received, the system message including at least one of downlink transmission frequency information, an initial downlink BWP, BCCH configuration information, or PCCH configuration information.

[0215] For example, the system message may include downlink transmission frequency information, an initial downlink BWP, BCCH configuration information, or PCCH configuration information. In another example, the system message may include downlink transmission frequency information and an initial downlink BWP, or BCCH configuration information and PCCH configuration information, or downlink transmission frequency information and BCCH configuration information, or downlink transmission frequency information and PCCH configuration information, or initial downlink BWP and BCCH configuration information, or initial downlink BWP and PCCH configuration information. In yet another example, the system message may include downlink transmission frequency information, an initial downlink BWP and BCCH configuration information, or initial downlink BWP, BCCH configuration information, and PCCH configuration information, or downlink transmission frequency information, BCCH configuration information, and PCCH configuration information, or downlink transmission frequency information, an initial downlink BWP, and PCCH configuration information. In yet another example, the system message includes downlink transmission frequency information, an initial downlink BWP, BCCH configuration information, and PCCH configuration information.

[0216] In this step, the target network device can broadcast the system message within its corresponding network coverage, and each terminal within the network coverage can receive the system message, i.e., the target terminal can receive the system message.

[0217] The system message may include downlink common configuration information for downlink small data transmission and reception, which may include downlink transmission frequency information, an initial downlink BWP, BCCH configuration information, and PCCH configuration information.

[0218] The initial downlink BWP is the initial downlink BWP configuration of the primary cell (i.e., the PCell). The BCCH configuration information is a configuration for modifying the passing period of system messages. The PDCCH configuration information includes the default paging period, paging frame number and configuration, the number of paging occasions, and the first PDCCH monitoring occasion.

[0219] The default paging cycle is the default paging cycle broadcast in system messages. The paging frame number and configuration are used to derive the total number of paging frames and the paging frame offset. The number of paging occasions is used to indicate the number of paging occasions in each paging frame. A paging occasion is a group of PDCCH monitoring occasions consisting of multiple time slots for sending paging control information. The first PDCCH monitoring occasion is the first PDCCH monitoring occasion that indicates monitoring the paging occasion of the paging frame.

[0220] In the embodiment of the present disclosure, the order in which the above steps S801 to S803 are performed is not particularly limited.

[0221] In step S804, a smaller value of the radio paging cycle and the default paging cycle is determined as a first time period for receiving paging messages when the target terminal is in an inactive state, where the radio paging cycle is a RAN paging cycle configured by a Radio Access Network (RAN) side node for the inactive terminal.

[0222] In this step, the target terminal can obtain the smaller paging cycle of the default paging cycle and the radio paging cycle according to the default paging cycle in the downlink common configuration information included in the system message and the radio paging cycle in the suspension configuration information included in the first release message, and determine this paging cycle as the time period for receiving paging messages by the target terminal (i.e., the first time period). That is, when the default paging cycle is shorter than the radio paging cycle, the default paging cycle is determined as the first time period, and when the default paging cycle is longer than the radio paging cycle, the radio paging cycle is determined as the first time period.

[0223] Through the above steps S803 to S804, the target terminal can determine the time period for receiving the paging message at the target terminal itself according to the paging period contained in the system message and the first release message, thereby effectively ensuring that the target terminal can receive the paging message issued by the target network device as much as possible.

[0224] In step S805, when the current state of the target terminal is an inactive state, a paging message issued by the target network device is received according to a first time period.

[0225] In some embodiments, the first time period is the smaller of a radio paging period in the suspension configuration information and a default paging period in the downlink common configuration information.

[0226] In step S806, when the received paging message includes a designated paging record for the target terminal, a connection resumption request is sent to the target network device, whereby the target network device sends downlink small data packets to the target terminal based on the received connection resumption request. The designated paging record includes a mobile-terminated small data transmission indication, and the connection resumption reason in the connection resumption request is mobile-terminated small data transmission.

[0227] In step S807, a downlink small data packet sent by the target network device is received.

[0228] The above steps S805 to S807 are the same as the above steps S101 to S103.

[0229] In some embodiments, the connection resumption request may also include an uplink small data packet. When the connection resumption request includes an uplink small data packet, according to the above method shown in FIG. 1, an embodiment of the present disclosure also provides a data transmission method. As shown in FIG. 9, FIG. 9 is a schematic flowchart of an eighth data transmission method provided by an embodiment of the present disclosure. The method includes the following steps:

[0230] In step S901, when a current state of a target terminal is an inactive state, a paging message issued by a target network device is received according to a first time period.

[0231] The above step S901 is the same as the above step S101.

[0232] In step S902, when the received paging message includes a designated paging record for the target terminal, a connection resumption request is sent to the target network device, whereby the target network device sends downlink small data packets to the target terminal based on the received connection resumption request. The designated paging record includes a mobile-terminated small data transmission indication, and the connection resumption reason in the connection resumption request is mobile-terminated small data transmission.

[0233] In the above step S902, when the target terminal sends a connection resumption request to the target network device, the connection resumption request may further include an uplink small data packet. The uplink small data packet is uplink data or a data packet corresponding to a subpacket obtained by dividing the uplink data. For the uplink small data packet, please refer to the above description of the downlink small data packet, and it will not be specifically described here.

[0234] The data amount of the uplink small data packet may be equal to or less than a second data amount threshold.

[0235] In an embodiment of the present disclosure, when the target network device receives the connection resumption request including the uplink small data packet, in addition to sending the downlink small data packet to the target terminal, the target network device can also generate corresponding feedback information for the uplink small data packet in the connection resumption request and send the feedback information to the target terminal, i.e., send the downlink small data packet together with the feedback information to the target terminal. Here, the generation of the feedback information is not particularly described.

[0236] In step S903, the downlink small data packet sent by the target network device and the feedback information sent by the target network device for the uplink small data packet are received.

[0237] In this step, the target network device not only sends the above-mentioned downlink small data packet to the target terminal, but also sends feedback information for the above-mentioned uplink small data packet to the target terminal, so that the target terminal receives the above-mentioned downlink small data packet and feedback information.

[0238] In some embodiments, when the uplink small data packet is a subpacket corresponding to uplink data, that is, when the target terminal still has some uplink small data packets that have not been sent to the target network device, when the target terminal receives the feedback information sent by the target network device, the target terminal can send the remaining unsent uplink small data packets to the target network device. The target network device receives the uplink small data packets sent by the target terminal and obtains all uplink data sent by the target terminal to the target network device.

[0239] In the above embodiment, since the number of the remaining unsent uplink small data packets may be two or more, the target terminal transmits only one uplink small data packet in each transmission process during the mobile-originated small data transmission process, and the data amount of each uplink small data packet is equal to or less than the second data amount threshold.

[0240] The second data volume threshold may be equal to or greater than the first data volume threshold, and may be specifically set by referring to the method for setting the first data volume threshold. Here, the second data volume threshold is not particularly limited.

[0241] During the above uplink small data transmission process, the uplink small data packet can be transmitted using a small data transmission resource configured by the CG configuration information allocated by the target network device, or using an uplink time-frequency resource temporarily scheduled by the target network device.

[0242] By carrying the above-mentioned uplink small data packet in the above-mentioned connection resumption request, an inactive uplink data transmission process is realized, the signaling overhead and delay consumption caused by switching from an inactive state to a connected state are avoided, the transmission efficiency of the uplink small data packet is improved, and the signaling overhead of the uplink small data packet is saved, thereby effectively reducing the signaling overhead and delay consumption in the data transmission process.

[0243] In some embodiments, according to the above method shown in Figure 1, the embodiment of the present disclosure also provides a data transmission method. As shown in Figure 10, Figure 10 is a ninth schematic flowchart of the data transmission method provided by the embodiment of the present disclosure. The method includes the following steps:

[0244] In step S1001, when a current state of the target terminal is an inactive state, a paging message issued by a target network device is received according to a first time period.

[0245] In step S1002, when the received paging message includes a designated paging record for the target terminal, a connection resumption request is sent to the target network device, whereby the target network device sends downlink small data packets to the target terminal based on the received connection resumption request. The designated paging record includes a mobile-terminated small data transmission indication, and the connection resumption reason in the connection resumption request is mobile-terminated small data transmission.

[0246] In step S1003, a downlink small data packet sent by a target network device is received.

[0247] The above steps S1001 to S1003 are the same as the above steps S101 to S103.

[0248] In step S1004, a second release message sent by the target network device when the transmission of the downlink small data packet is completed is received, the second release message including instruction information indicating a state change.

[0249] In this step, when the target network device completes the transmission of the downlink small data packets, i.e., after sending all downlink small data packets corresponding to the downlink data to the target terminal, the target network device can send an RRC release message (recorded as a second release message) to the target terminal, and the target terminal receives the second release message.

[0250] In an embodiment of the present disclosure, the indication information in the second release message may be used to indicate that the current state of the terminal is to be switched to an inactive state, or may be used to indicate that the current state of the terminal is to be switched to an idle state, like the suspension configuration information. The indication information in the second release message also changes depending on another state to which the target terminal is requested to switch. Here, the indication information in the second release message is not particularly limited.

[0251] In step S1005, the current state is switched to the inactive state or the idle state based on the instruction information.

[0252] In this step, after receiving the second release message, the target terminal can perform state switching according to the instruction information in the second release message, for example, switching the current state to an inactive state or an idle state. The state switching process of the target terminal is not specifically described here.

[0253] In an embodiment of the present disclosure, after the target terminal is switched to an inactive state or an idle state according to the indication information of the second release message, the target terminal and the target network device can no longer perform the small data transmission in the inactive state, i.e., the uplink small data packet transmission and the downlink small data packet transmission are no longer performed.

[0254] By sending the above second release message, the RRC connection between the target terminal and the target network device can be disconnected in time when the small data transmission in the inactive state is completed, thereby freeing up system resources.

[0255] In some embodiments, when the number of the downlink small data packets is two or more, for a last-transmitted downlink small data packet among the downlink small data packets, the target network device may send this downlink small data packet together with the second release message to the target terminal, in order to further reduce signaling overhead and delay consumption during the data transmission process.

[0256] In the above embodiment, the second release message is sent after the transmission of the last downlink small data packet corresponding to the downlink data. Furthermore, when the amount of uplink data is greater than that of downlink data, that is, when the transmission of all downlink small data packets is completed but the transmission of all uplink small data packets is not completed, the target network device can send the second release message to the target terminal after receiving the last uplink small data packet. Here, the transmission time of the second release message is not particularly limited.

[0257] Based on the same inventive concept as the above data transmission method provided by the embodiment of the present disclosure, the present disclosure also provides a data transmission method, as shown in Figure 11, which is a schematic flowchart of a tenth data transmission method provided by the embodiment of the present disclosure. This method is applied to a target network device and particularly includes the following steps:

[0258] In step S1101, a paging message is sent to a target terminal whose current state is an inactive state according to a second time period.

[0259] In this step, the target network device can send a paging message to a terminal in a connected state or an inactive state within the network coverage of the target network device according to the second time period, and the terminal within the network coverage of the target network device receives the paging message, i.e., the target terminal receives the paging message.

[0260] In the embodiment of the present disclosure, the paging message can be sent in the form of multicast / broadcast, etc. Here, the method of sending the paging message is not particularly limited.

[0261] In some embodiments, the paging message may include a paging record list, which is a list for recording terminals being paged, and which includes at least one paging record.

[0262] In some embodiments, the paging record includes at least one of a terminal identity of the paged terminal, an access type, or a mobile-terminated small data transmission indication.

[0263] For example, the paging record may include the terminal identity of the paged terminal, an access type, or a mobile-terminated small data transmission indication. In another example, the paging record may include the terminal identity and access type of the paged terminal, or the terminal identity and mobile-terminated small data transmission indication of the paged terminal, or the access type and mobile-terminated small data transmission indication. In yet another example, the paging record may include the terminal identity, access type, and mobile-terminated small data transmission indication of the paged terminal.

[0264] The terminal identity includes the NAS ID assigned to the terminal by the NAS for core network paging and the full inactive state terminal identity for RAN paging. The access type above is used to indicate whether the paging message is initiated by a PDU session not accessed by 3GPP. The mobile terminated small data transmission indication is used to indicate that the paging message is used to trigger a mobile terminated small data transmission.

[0265] In some embodiments, the paging record may further include a contention-free access preamble indicating to the terminal to initiate a contention-free random access.

[0266] In step S1102, a connection resumption request sent by the target terminal is received. The connection resumption request is sent by the target terminal when a paging message including a designated paging record for the target terminal itself is received. The designated paging record includes a mobile-terminated small data transmission instruction. The connection resumption reason in the connection resumption request is mobile-terminated small data transmission.

[0267] In this step, after the target network device sends the above paging message to the target terminal, when the paging message includes a paging record designated by the target terminal itself, the target terminal sends a connection resumption request to the target network device, with the connection resumption reason being mobile-terminated small data transmission. The target network device receives the connection resumption request.

[0268] The designated paging record includes a mobile-terminated small data transmission instruction. For a description of the designated paging record, please refer to the above description, and it will not be described in detail here.

[0269] In step S1103, a downlink small data packet is sent to the target terminal based on the connection resumption request, so that the target terminal receives the downlink small data packet.

[0270] In this step, after the target network device receives the connection resumption request sent by the target terminal, the connection resumption reason in the connection resumption request is mobile-terminated small data transmission, so the target network device can obtain a downlink small data packet based on the connection resumption reason and send the downlink small data packet to the target terminal. For a description of the downlink small data packet, please refer to the above description and will not be described in detail here.

[0271] In some embodiments, the connection resume request may be a first connection resume request or a second connection resume request, where the first connection resume request is sent by the target terminal when the SIB1 sent by the base station indicates that the connection resume request uses a full resume identifier, and the second connection resume request is sent by the target terminal when the SIB1 sent by the base station does not indicate that the connection resume request uses a full resume identifier.

[0272] The first connection resumption request and the second connection resumption request each include a resumption identifier, a resumption integrity check code, and a connection resumption reason.

[0273] The resumption identifier of the first connection resumption request is the full inactive state terminal identity stored by the target terminal, and the resumption identifier of the second connection resumption request is the shortened inactive state terminal identity stored by the target terminal. The full inactive state terminal identity and the shortened inactive state terminal identity are wireless network temporary identifier values ​​of the terminal in the inactive state and are used by the target network side to find the anchor point before the terminal entered the inactive state and the access stratum context information stored by the anchor point. The full inactive state terminal identity and the shortened inactive state terminal identity have different sizes. The resumption integrity check code is an identity authentication token for terminal identity authentication at the base station.

[0274] In the first and second connection resume requests, the resume identifier is a UE identifier for facilitating UE context information retrieval at the gNB, such as resumeIdentify in RRCResumeRequest1 of the related standard TS38.331. The resume integrity check code is a bit string and is an authentication token for UE authentication at the gNB (such as resumeMAC-I in the related standard TS38.331). The resume reason is a resume reason provided by a higher layer or RRC and added to the first connection resume request. When the UE uses an unknown cause value (such as MT-SDT in the embodiment of the present disclosure), the gNB does not reject the first connection resume request in accordance with related standards such as resumeCause in TS38.331.

[0275] 11, when the target terminal receives a paging message including a paging record designated by the target network device when the target terminal is in an inactive state, a connection resumption request can be sent to the target network device to trigger a small data transmission process between the target terminal and the target network device when the terminal is in an inactive state. At this time, the target network device can send a downlink small data packet to the target terminal based on the received connection resumption request, and the target terminal also receives the downlink small data packet, thereby realizing the downlink small data packet transmission process of the terminal in an inactive state.

[0276] Furthermore, compared with related technologies in which a terminal in an inactive state must switch to a connected state for data transmission, the embodiment of the present disclosure introduces a new terminal access type, namely, mobile-terminated small data transmission, through a mobile-terminated small data transmission indication in a designated paging record, so that the terminal can receive downlink small data packets sent by a target network device when in an inactive state. The signaling overhead and delay consumption caused by switching from an inactive state to a connected state are avoided, the transmission efficiency of downlink small data packets is improved, and the signaling overhead of downlink small data packets is saved, thereby effectively reducing the signaling overhead and delay consumption in the data transmission process.

[0277] In some embodiments, according to the above method shown in Figure 11, the embodiment of the present disclosure also provides a data transmission method. As shown in Figure 12, Figure 12 is a schematic flowchart of an eleventh data transmission method provided by the embodiment of the present disclosure. The method includes the following steps:

[0278] In step S1201, a first release message is issued to the terminal, the first release message including suspension configuration information indicating that the terminal should implement an inactive state configuration, so that the target terminal switches its current state to an inactive state based on the suspension configuration information.

[0279] In this step, the target network device can send an RRC release message (i.e., the first release message) to the target terminal in the connected state. The first release message includes suspension configuration information indicating that the terminal is to be configured to be in the inactive state. After receiving the first release message, the target terminal can switch its state according to the suspension configuration information in the first release message, i.e., switch its current state from the connected state to the inactive state.

[0280] The suspension configuration information includes full inactive state terminal identification information, shortened inactive state terminal identification information, radio paging cycle, radio notification area information, timer, next hop chaining count value, and mobile terminated small data transmission configuration information.

[0281] The above-mentioned full inactive state terminal identity information and shortened inactive state terminal identity information are wireless network temporary identifier values ​​of a terminal in an inactive state, and are used by the target network side to find the anchor point node before the terminal entered the inactive state and the access stratum context information stored by the anchor point node. The full inactive state terminal identity information and shortened inactive state terminal identity information have different sizes.

[0282] The radio paging cycle is the RAN paging cycle configured by the RAN side node for the terminal in the inactive state.

[0283] The radio notification area information includes a cell list and a radio area configuration list. The cell list is a list of the radio notification area in the RAN. as A list of configured cells, the radio area configuration list includes the RAN area code or the RA code of the RAN area.

[0284] The timer is used to trigger the periodic RNAU process in the terminal.

[0285] The next-hop chaining count value is used to calculate security keys after the connection is resumed.

[0286] Mobile terminated small data transmission configuration information is Mobile Terminated DRB list for small data transmission or Mobile Terminated Includes at least one of the SRB2 indications for small data transmission. Mobile Terminated The DRB list for small data transmission indicates the DRB identifiers of the small data transmission configuration, Mobile Terminated The small data transmission SRB2 indication is used to indicate the presence or absence of SRB2 in the terminal's small data transmission configuration. For example, the mobile-terminated small data transmission configuration information is Mobile Terminated DRB list for small data transmission or Mobile Terminated In another example, the configuration information for mobile-terminated small data transmission includes an SRB2 indication of small data transmission. Mobile Terminated DRB list for small data transmission and Mobile Terminated Includes SRB2 instructions for sending small data.

[0287] In some embodiments, the above configuration information for mobile terminated small data transmission may further include CG configuration information. Committed love The information includes the CG SSB RSRP threshold, the CG timing advance timer, the CG timing advance verification configuration, and the CG RSRP variation threshold.

[0288] The CG SSB RSRP threshold is the RSRP threshold selected by an SSB that performs small data transmissions based on CG resources. The CG timing advance timer is used for timing synchronization of small data transmissions. The CG timing advance verification configuration is used for configuring TA verification based on RSRP. The CG RSRP variation threshold is the RSRP threshold for TA verification of small data transmissions.

[0289] Through the above step S1201, the target terminal can switch its current state from a connected state to an inactive state according to the first release message issued by the target network device, thereby enabling the target terminal to switch its current state from a connected state to an inactive state. to inactive state This facilitates quick entry into the inactive state and also facilitates the process of small data transmission in the inactive state when the designated paging record of the target terminal is later received, thereby reducing signaling overhead and delay consumption during the data transmission process.

[0290] In step S1202, a system message is broadcast, the system message including at least one of downlink transmission frequency information, an initial downlink BWP, BCCH configuration information, and PCCH configuration information.

[0291] For example, the system message may include downlink transmission frequency information, an initial downlink BWP, BCCH configuration information, or PCCH configuration information. In another example, the system message may include downlink transmission frequency information and an initial downlink BWP, or BCCH configuration information and PCCH configuration information, or downlink transmission frequency information and BCCH configuration information, or downlink transmission frequency information and PCCH configuration information, or initial downlink BWP and BCCH configuration information, or initial downlink BWP and PCCH configuration information. In yet another example, the system message may include downlink transmission frequency information, an initial downlink BWP and BCCH configuration information, or initial downlink BWP, BCCH configuration information, and PCCH configuration information, or downlink transmission frequency information, BCCH configuration information, and PCCH configuration information, or downlink transmission frequency information, an initial downlink BWP, and PCCH configuration information. In yet another example, the system message may include downlink transmission frequency information, an initial downlink BWP, BCCH configuration information, and PCCH configuration information.

[0292] In this step, the target network device can broadcast a system message within its network coverage, and all terminals within the network coverage of the target network device will receive the system message. That is, the target terminals will receive the system message.

[0293] In some embodiments, the downlink transmission frequency information is used to indicate the transmission frequency of downlink small data packets. The initial downlink BWP is the initial downlink BWP configuration of the primary cell. The BCCH configuration information is a configuration for modifying the passing period of system messages. The PDCCH configuration information includes a default paging period, a paging frame number and configuration, the number of paging occasions, and the first PDCCH monitoring occasion.

[0294] The default paging cycle is the default paging cycle broadcast in system messages. The paging frame number and configuration are used to derive the total number of paging frames and the paging frame offset. The number of paging occasions is used to indicate the number of paging occasions in each paging frame. A paging occasion is a group of PDCCH monitoring occasions consisting of multiple time slots for sending paging control information. The first PDCCH monitoring occasion is the first PDCCH monitoring occasion that indicates monitoring the paging occasion of the paging frame.

[0295] In the embodiment of the present disclosure, the order in which the above steps S1201 and S1202 are performed is not particularly limited.

[0296] In step S1203, a default paging period is determined as a second time period for sending a paging message.

[0297] In an embodiment of the present disclosure, the second time period for sending a paging message by the target network device may be a radio paging period included in the first release message.

[0298] In step S1204, a paging message is sent to the target terminal whose current state is an inactive state according to a second time period.

[0299] In step S1205, a connection resumption request sent by the target terminal is received. The connection resumption request is sent by the target terminal when a paging message including a designated paging record of the target terminal itself is received. The designated paging record includes a mobile-terminated small data transmission instruction. The connection resumption reason in the connection resumption request is mobile-terminated small data transmission.

[0300] In step S1206, a downlink small data packet is sent to the target terminal based on the connection resumption request, so that the target terminal receives the downlink small data packet.

[0301] The above steps S1204 to S1206 are the same as the above steps S1101 to S1103.

[0302] In some embodiments, the connection resumption request may also include an uplink small data packet. When the connection resumption request includes an uplink small data packet, according to the above method shown in FIG. 11, an embodiment of the present disclosure also provides a data transmission method. As shown in FIG. 13, FIG. 13 is a schematic flowchart of a twelfth data transmission method provided by an embodiment of the present disclosure. The method includes the following steps:

[0303] In step S1301, a paging message is sent to a target terminal whose current state is an inactive state according to a second time period.

[0304] The above step S1301 is the same as the above step S1101.

[0305] In step S1302, a connection resumption request sent by the target terminal is received. The connection resumption request is sent by the target terminal when a paging message including a designated paging record for the target terminal itself is received. The designated paging record includes a mobile-terminated small data transmission instruction. The connection resumption reason in the connection resumption request is mobile-terminated small data transmission.

[0306] In the above step S1302, the connection resumption request sent by the target terminal to the target network device may further include an uplink small data packet, which is a data packet corresponding to uplink data sent by the target terminal to the target network device or corresponding to multiple subpackets obtained by dividing the uplink data.

[0307] In step S1303, when a connection resumption request is received, feedback information about the uplink small data packet is generated, and the downlink small data packet is obtained.

[0308] In step S1304, the downlink small data packet and feedback information are sent to the target terminal.

[0309] In an embodiment of the present disclosure, an uplink small data packet is added during the connection resumption request so that a downlink small data packet transmission is completed while an uplink small data packet transmission is being performed, thereby improving data transmission efficiency.

[0310] In some embodiments, according to the above method shown in Figure 11, the embodiment of the present disclosure also provides a data transmission method. As shown in Figure 14, Figure 14 is a schematic flowchart of a thirteenth data transmission method provided by the embodiment of the present disclosure. The method includes the following steps:

[0311] In step S1401, a paging message is sent to a target terminal whose current state is an inactive state according to a second time period.

[0312] In step S1402, a connection resumption request sent by the target terminal is received. The connection resumption request is sent by the target terminal when a paging message including a designated paging record for the target terminal itself is received. The designated paging record includes a mobile-terminated small data transmission instruction. The connection resumption reason in the connection resumption request is mobile-terminated small data transmission.

[0313] In step S1403, a downlink small data packet is sent to the target terminal based on the connection resumption request, so that the target terminal receives the downlink small data packet.

[0314] The above steps S1401 to S1403 are the same as the above steps S1101 to S1103.

[0315] In step S1404, when the downlink small data packet transmission is completed, a second release message is sent to the target terminal, the second release message including instruction information indicating state switching, so that the target terminal switches its current state to an inactive state or an idle state based on the instruction information.

[0316] In this step, after sending the downlink small data packet to the target terminal, the target network device can send a second release message to the target terminal, the second release message including instruction information to indicate to the terminal to perform state switching. Upon receiving the second release message, the target terminal can switch its current state to an inactive state or an idle state according to the instruction information in the second release message.

[0317] By sending the second release message described above, the state of the target terminal can be switched in time to the inactive state or the idle state after the mobile-terminated small data transmission is completed.

[0318] In some embodiments, to further reduce signaling overhead during the process of mobile-terminated small data transmission, when the target network device sends downlink small data packets to the target terminal, if the number of downlink small data packets is two or more, when the last downlink small data packet is sent, if the sum of the data amount of the last downlink small data packet and the data amount of the second release message is less than the bearing capacity of the wireless channel, the target network device can add the last downlink small data packet to a second release message and send the last downlink small data packet together with the second release message to the target terminal.

[0319] For ease of understanding, the above process of small data transmission in an inactive state will be described in conjunction with Figure 15. Figure 15 is a signaling diagram of the process of data transmission in an inactive state provided by an embodiment of the present disclosure.

[0320] In step S1501, the gNB sends an RRC release message to the UE. The RRC release message includes suspension configuration information. News include.

[0321] The current state of the UE is a connected state, the suspension configuration information includes a radio paging cycle, and the suspension configuration information may also include CG configuration information.

[0322] In step S1502, the UE switches its current state to an inactive state according to the suspension configuration information in the received RRC release message.

[0323] In step S1503, the gNB broadcasts a system message, which includes downlink common configuration information.

[0324] The downlink common configuration information includes downlink transmission frequency information, initial downlink BWP, BCCH configuration information, and PCCH configuration information. The PCCH configuration information includes information such as a default paging cycle.

[0325] In step S1504, the gNB sends a paging message to the UE, the paging message including a terminal identity that matches the fully inactive state terminal identity stored by the UE and a designated paging record that includes a mobile terminated small data transmission instruction.

[0326] In this step, the gNB sends the paging message to the UE at a time period equal to the radio paging cycle. In addition, the designated paging record may also include a contention-free access preamble.

[0327] In step S1505, the UE receives the paging message sent by the gNB.

[0328] In this step, the UE receives the paging message sent by the target network device for a time period equal to the smaller value of the above radio paging period and the default paging period.

[0329] In step S1506, the UE sends an RRC connection resumption request to the gNB. The RRC connection resumption request includes a connection resumption reason and an uplink small data packet. The connection resumption reason is a mobile terminated small data transmission.

[0330] The above RRC connection resumption request also includes a value indicating the access type (eg, the above access type N).

[0331] Depending on whether the RRC release message contains CG configuration information and whether the paging message contains a contention-free access preamble, the UE may send the RRC connection resumption request using a random access method or with a configured grant type that matches the CG configuration.

[0332] In the above step S1506, when the target terminal has no uplink data to send to the target network device, the above RRC connection resumption request does not include the above uplink small data packet.

[0333] In step S1507, after receiving the RRC connection resumption request, the gNB generates feedback information corresponding to the uplink small data packet, and sends the downlink small data packet and the feedback information to the UE.

[0334] In step S1508, the UE receives the downlink small data packet and the feedback information.

[0335] In step S1509, the UE sends an uplink small data packet to the gNB.

[0336] In this step, when there are multiple uplink small packets corresponding to uplink data, the UE continues to send the remaining unsent uplink small packets to the gNB after receiving the above feedback information.

[0337] In step S1510, the gNB sends a downlink small data packet to the UE.

[0338] In this step, when there are multiple downlink small data packets corresponding to the downlink data, the gNB 507 After performing this, downlink small data packets can continue to be sent to the UE.

[0339] In step S1511, the gNB sends an RRC release message to the UE.

[0340] The RRC release message includes an indication that the state is being switched.

[0341] When there are multiple downlink small data packets corresponding to the downlink data, the RRC release message may also include the last downlink small data packet corresponding to the downlink data.

[0342] The uplink small data packet / downlink small data packet in the above steps S1509 to S1511 is a subpacket corresponding to the remaining uplink data / downlink data that has not been transmitted after the transmission process of the first uplink small data packet / downlink small data packet. The above steps S1509 and S1510 can be performed multiple times, with only one small data packet being transmitted at a time.

[0343] In step S1512, the UE switches to an inactive state or an idle state according to the received RRC release message.

[0344] In this step, the state of the UE after the switch also changes according to different indication information in the RRC release message.

[0345] Based on the same inventive concept and according to the above data transmission method provided by the embodiment of the present disclosure, the embodiment of the present disclosure also provides a data transmission device. As shown in Figure 16, Figure 16 is a first schematic structural diagram of a data transmission device provided by the embodiment of the present disclosure. The data transmission device is applied to a target terminal and particularly includes the following modules:

[0346] The first receiving module 1601 is used for receiving a paging message issued by a target network device according to a first time period when the current state of the target terminal is an inactive state.

[0347] The first sending module 1602 is used to send a connection resumption request to the target network device when the received paging message includes a designated paging record of the target terminal, whereby the target network device sends a downlink small data packet to the target terminal based on the received connection resumption request, where the designated paging record includes a mobile-terminated small data transmission indication and the connection resumption reason in the connection resumption request is mobile-terminated small data transmission.

[0348] The second receiving module 1603 is used to receive downlink small data packets sent by the target network device.

[0349] In some embodiments, the paging message includes a paging record list, which is a list for recording terminals to be paged, and the paging record list includes at least one paging record.

[0350] In some embodiments, the paging record includes at least one of a terminal identity of the terminal being paged, an access type, or a mobile-terminated small data transmission indication, where the terminal identity includes a NAS ID assigned to the terminal by the NAS for core network paging and a fully inactive terminal identity for RAN paging; the access type is used to indicate whether the paging message is a paging message initiated by a PDU session that is not accessed by 3GPP; and the mobile-terminated small data transmission indication is used to indicate that the paging message is used to trigger a mobile-terminated small data transmission.

[0351] In some embodiments, the paging record further includes a contention-free access preamble that indicates to the terminal to initiate contention-free random access.

[0352] In some embodiments, the data transmission apparatus further includes: an analysis module for analyzing each paging record in a received paging message after receiving the paging message issued by the target network device according to a first time period; and a first determination module for determining, for each paging record obtained by the analysis, if the completely inactive state terminal identification information in the paging record matches the completely inactive state terminal identification information stored by the target terminal and the paging record includes a mobile-terminated small data transmission indication, that the paging record is a designated paging record of the target terminal; and targetand a second determination module for determining that the paging record is not a designated paging record for the target terminal when it does not match the fully inactive state terminal identification information stored by the terminal and / or when the paging record does not include a mobile terminated small data transmission indication.

[0353] In some embodiments, the above-mentioned first sending module 1602 can be specifically used to send a connection resumption request to a target network device based on configured grant (CG) configuration information when the target terminal stores CG configuration information and the received paging message includes a designated paging record for the target terminal.

[0354] In some embodiments, the above-mentioned first sending module 1602 can be specifically used for sending a connection resumption request to the target network device in a contention-free access method when the received paging message includes a designated paging record for the target terminal and the designated paging record does not include a contention-free access preamble, if the target terminal does not store configured grant (CG) configuration information; and for sending a connection resumption request to the target network device in a contention-free access method when the received paging message includes a designated paging record for the target terminal and the designated paging record includes a contention-free access preamble.

[0355] In some embodiments, the above-mentioned data transmission apparatus may further include: a determination module for determining whether the target terminal satisfies a preset connection initiation condition at a current time before sending a connection resumption request to the target network device, where the preset connection initiation condition is that a mobile-terminated small data transmission indication is received, or the preset connection initiation condition is that a mobile-terminated small data transmission indication is received and a downlink reference signal received power (RSRP) is greater than a preset threshold; and an implementation module for performing the step of sending a connection resumption request to the target network device when the target terminal satisfies the preset connection initiation condition.

[0356] In some embodiments, the data transmission apparatus further comprises an implementation module for sending another connection resumption request when another preset connection initiation condition is met, such that the target terminal sends uplink data packets to the target network device after the connection corresponding to the another connection resumption request is resumed, wherein the another preset connection initiation condition is that the data volume of the radio bearer configured for mobile-originate small data transmission is less than a preset data volume threshold, or the another preset connection initiation condition is that the data volume of the radio bearer configured for mobile-originate small data transmission is less than a preset data volume threshold and uplink small data transmission resources are available.

[0357] In some embodiments, the preset connection initiation condition is that a mobile terminated small data transmission indication is received; or that a mobile terminated small data transmission indication is received and a lower layer below the radio resource control (RRC) layer: Mobile Terminated This can be expressed as indicating that the trigger condition for small data transmission is met.

[0358] In some embodiments, another preset connection initiation condition is that higher layers above the Radio Resource Control (RRC) layer request a resumption of the RRC connection, SIB1 includes a common configuration for small data transmission, the small data transmission configuration is configured, all uplink small data is mapped to radio bearers of the small data transmission configuration, and lower layers below the RRC layer: Mobile Originated This is expressed as indicating that the trigger condition for small data transmission is met.

[0359] In some embodiments, the data transmission device further comprises: a data transmission device configured to transmit a data to a target terminal in an inactive state when the target terminal satisfies a preset connection initiation condition; Can Small Data Transmission Did it fail? of Monitoring The device may include a first initiation module that initiates a timer for initiating the

[0360] The data transmission device further comprises: connection The method may further include a second start module for starting a timer for monitoring the process and for sending a timeout indication to the MAC entity when the target terminal does not satisfy a preset connection start condition, the timeout indication being a configured grant (CG) timing advance timer in the CG configuration information for small data transmission. Stop Used to indicate

[0361] In some embodiments, the data transmission device may further comprise a release module for releasing the stored configured grant (CG) configuration information when the target terminal moves from a current radio access network (RAN) cell to another RAN cell and initiates a connection resumption process in the other RAN cell.

[0362] In some embodiments, the connection resumption request is a first connection resumption request or a second connection resumption request.

[0363] The above-mentioned first sending module 1602 can be used to select a first connection resume request as a connection resume request when the SIB1 sent by the base station indicates that the connection resume request uses a full resume identifier, or to select a second connection resume request as a connection resume request when the received SIB1 does not indicate the use of a full resume identifier; and to restore preset security information from stored access stratum context information, where the preset security information includes a Radio Resource Control (RRC) configuration, a Robust Header Compression (ROHC) state, a stored mapping relationship between a Quality of Service (QoS) flow and a Data Resource Bearer (DRB), a base station root key, and a full resume identifier. The first sending module 1602 may further include an integrity protection key; the first sending module 1602 may be further used, among other things, to reconstruct a Packet Data Convergence Protocol (PDCP) entity for SIB1; to restore SIB1; for each radio bearer configured for mobile-terminated small data transmission, to restore a configuration associated with the primary cell group and Radio Link Layer Control Protocol (RLC) bearer of the PDCP configuration from the access stratum context information and reconstruct a PDCP entity for this radio bearer; to resume all radio bearers configured for mobile-terminated small data transmission, and to send a connection resumption request to the target network device.

[0364] In some embodiments, the first connection resumption request and the second connection resumption request each include a resumption identifier, a resumption integrity check code, and a connection resumption reason, wherein the resumption identifier of the first connection resumption request is a full inactive state terminal identity stored by the target terminal, and the resumption identifier of the second connection resumption request is a shortened inactive state terminal identity stored by the target terminal, and the full inactive state terminal identity and the shortened inactive state terminal identity are radio network temporary identifier values ​​of the terminal in the inactive state and are used by the target network side to find the anchor point before the terminal entered the inactive state and the access stratum context information stored by the anchor point, and the full inactive state terminal identity and the shortened inactive state terminal identity have different sizes; and the resumption integrity check code is an identity authentication token for terminal identity authentication at the base station.

[0365] In some embodiments, the above-mentioned data transmission apparatus may further include: a third receiving module for receiving a first release message issued by the target network device when the current state of the target terminal is a connected state, the first release message including suspension configuration information indicating that an inactive state configuration is to be implemented for the terminal; and a first switching module for switching the current state to an inactive state based on the suspension configuration information.

[0366] In some embodiments, the suspension configuration information may include full inactive state terminal identification information, shortened inactive state terminal identification information, radio paging period, radio notification area information, timers, next hop chaining count values, and mobile terminated small data transmission configuration information.

[0367] In some embodiments, the full inactive state terminal identity and the shortened inactive state terminal identity are radio network temporary identifier values ​​of the terminal in the inactive state, and are used by the target network side to find the anchor point node before the terminal entered the inactive state and the access stratum context information stored by the anchor point node, and the full inactive state terminal identity and the shortened inactive state terminal identity have different sizes.

[0368] The above radio paging cycle refers to a RAN paging cycle configured by a Radio Access Network (RAN) side node for a terminal in an inactive state.

[0369] The above-mentioned radio notification area information includes a cell list and a radio area configuration list. The cell list is a list of radio notification areas in the RAN area. as A list of configured cells. The radio area configuration list is a list of configured cells. The radio area configuration list is a list of configured cells. The list of configured cells ... RA Includes code.

[0370] The timer is used to trigger a periodic RAN-based notification area update (RNAU) process in the terminal.

[0371] The above next-hop chaining count value is used to calculate the security key after the connection is resumed.

[0372] The above configuration information for Mobile Terminated Small Data Transmission is Mobile Terminated Data Resource Bearer (DRB) list for small data transmission or Mobile Terminated and at least one of a signaling radio bearer 2 (SRB2) indication of small data transmission; Mobile Terminated The DRB list for small data transmission indicates the DRB identifiers of the small data transmission configuration; Mobile Terminated The SRB2 indication for small data transmission indicates whether or not SRB2 is present in the small data transmission configuration of the terminal.

[0373] In some embodiments, the above configuration information for mobile terminated small data transmission is a configured grant (CG) configuration. Committed love The CG configuration information further includes information about a CG SSB RSRP threshold, a CG timing advance timer, a CG timing advance verification configuration, and a CG RSRP variation threshold.

[0374] The above CG SSB RSRP threshold is the reference signal received power (RSRP) threshold selected by the SSB that performs small data transmission based on the CG resource.

[0375] The CG timing advance timer mentioned above is used for timing synchronization of small data transmissions.

[0376] The above CG timing advance verification configuration is used for the configuration of RSRP-based timing advance (TA) verification.

[0377] The above CG RSRP fluctuation threshold is the RSRP threshold for TA verification of small data transmission.

[0378] In some embodiments, the first switching module: resets the media access control (MAC) to release the default MAC cell group configuration; applies suspension configuration information; and, when the suspension configuration information includes CG configuration information, Mobile Terminated Each DRB in the DRB list for small data transmission Mobile Terminated SRB2 instruction for small data transmission SRB2 shown in and Mobile TerminatedTo determine the DRB and SRB2 in the process of small data transmission, to re-establish a Radio Link Layer Control Protocol (RLC) entity for each RLC bearer in the target terminal configuration, to trigger a Packet Data Convergence Protocol (PDCP) entity to perform a Session Data Unit (SDU) discard process for the resumed SRB2 and SRB1, to indicate to the MAC entity to configure CG resources for small data transmission and to start a CG timing advance timer; the current Access Stratum Root Key (KgNB) and Integrity Protection Key (KRRCint) for Radio Resource Control (RRC) signaling, the Robust Header Compression (ROHC) state, the stored mapping rules between Quality of Service (QoS) flows and Data Resource Bearers (DRBs), the Cell-Radio Network Temporary Identifier (C-RNTI) used in the source primary cell (PCell), the cell identifier and physical cell identifier of the source PCell, and the new Radio Primary-Secondary Cell (NR Primary-Secondary Cell (NR Second ... It is used, among other things, to store the special cell (SpCell) common configuration in the synchronization reconfiguration message of the PCell, the parameters in the synchronization reconfiguration message of the NR PSCell, the mobility control information of the secondary cell group (SCG) of the E-UTRA PSCell, the primary and secondary cell (PSCell) configuration of the EN-DC and all other configuration parameters except the serving cell common configuration SIB of the access stratum context information of the terminal in inactive state; to suspend all SRBs except SRB0 and DRBs; to indicate to the lower layers below the RRC layer that PDCP suspension of all DRBs is to be performed; and to switch to inactive state and perform cell reselection.

[0379] In some embodiments, the data transmission apparatus may further include a fourth receiving module for receiving a system message broadcast by the target network device, the system message including at least one of downlink transmission frequency information, an initial downlink bandwidth portion (BWP), a broadcast control channel (BCCH) configuration information, or a paging channel (PCCH) configuration information.

[0380] In some embodiments, the downlink transmission frequency information is used to indicate the transmission frequency of the downlink small data packet.

[0381] The initial downlink BWP configuration above is the initial downlink BWP configuration of the primary cell.

[0382] The above BCCH configuration information is a configuration related to modifying the passing period of system messages.

[0383] The PDCCH configuration information includes a default paging cycle, a paging frame number and configuration, the number of paging occasions, and a first physical downlink control channel (PDCCH) monitoring occasion, where the default paging cycle is the default paging cycle broadcast in a system message, the paging frame number and configuration are used to derive the total number of paging frames and the paging frame offset, the number of paging occasions is used to indicate the number of paging occasions in each paging frame, the paging occasion is a group of PDCCH monitoring occasions consisting of multiple time slots for sending paging control information, and the first PDCCH monitoring occasion is the first PDCCH monitoring occasion for indicating that the paging occasion of the paging frame is to be monitored.

[0384] In some embodiments, the above-mentioned data transmission device may include a third determination module for determining, when the target terminal is in an inactive state, a smaller value of a radio paging period and a default paging period as a first time period for receiving a paging message, wherein the radio paging period is a Radio Access Network (RAN) paging period configured by a RAN side node for the terminal in the inactive state.

[0385] In some embodiments, the connection resume request also includes an uplink small data packet.

[0386] The above-mentioned second receiving module 1603 can be particularly used for receiving downlink small data packets sent by the target network device and feedback information sent by the target network device for uplink small data packets.

[0387] In some embodiments, the data transmission apparatus may further include a fifth receiving module for receiving a second release message sent by the target network device when the transmission of the downlink small data packet is completed, the second release message including instruction information indicating to switch the state; and a second switching module for switching the current state to an inactive state or an idle state based on the instruction information.

[0388] Based on the same inventive concept, according to the above data transmission method provided by the embodiment of the present disclosure, the embodiment of the present disclosure also provides a data transmission device, as shown in Figure 17, which is a second schematic structural diagram of the data transmission device provided by the embodiment of the present disclosure. The data transmission apparatus is applied to a target network device and particularly includes the following modules: a second sending module 1701 for issuing a paging message to the target terminal according to a second time period, where the current state of the target terminal is an inactive state; a sixth receiving module 1702 for receiving a connection resumption request sent by the target terminal, where the connection resumption request is sent by the target terminal upon receiving a paging message including a designated paging record of the target terminal itself, where the designated paging record includes a mobile-terminated small data transmission indication, and where the connection resumption reason in the connection resumption request is mobile-terminated small data transmission; and a third sending module 1703 for sending a downlink small data packet to the target terminal based on the connection resumption request, so that the target terminal receives the downlink small data packet.

[0389] In some embodiments, the paging message includes a paging record list, which is a list for recording terminals to be paged, and the paging record list includes at least one paging record.

[0390] In some embodiments, the paging record includes at least one of a terminal identity of the terminal being paged, an access type, or a mobile-terminated small data transmission indication.

[0391] The above terminal identity information includes the NAS ID assigned to the terminal by the NAS for core network paging and the complete inactive state terminal identity for RAN paging. The access type is used to indicate whether the paging message is a paging message initiated by a PDU session not accessed by 3GPP. The mobile terminated small data transmission indication is used to indicate that the paging message is used to trigger a mobile terminated small data transmission.

[0392] In some embodiments, the paging record further includes a contention-free access preamble that indicates to the terminal to initiate contention-free random access.

[0393] In some embodiments, the above connection resume request is a first connection resume request or a second connection resume request, where the first connection resume request is sent by the target terminal when the SIB1 sent by the base station indicates that the connection resume request uses a full resume identifier, and the second connection resume request is sent by the target terminal when the SIB1 sent by the base station does not indicate that the connection resume request uses a full resume identifier.

[0394] In some embodiments, the first connection resumption request and the second connection resumption request each include a resumption identifier, a resumption integrity check code, and a connection resumption reason.

[0395] The resumption identifier of the first connection resumption request is the full inactive state terminal identity stored by the target terminal, and the resumption identifier of the second connection resumption request is the shortened inactive state terminal identity stored by the target terminal. The full inactive state terminal identity and the shortened inactive state terminal identity are wireless network temporary identifier values ​​of the terminal in the inactive state and are used by the target network side to find the anchor point before the terminal entered the inactive state and the access stratum context information stored by the anchor point. The full inactive state terminal identity and the shortened inactive state terminal identity have different sizes. The resumption integrity check code is an identity authentication token for terminal identity authentication at the base station.

[0396] In some embodiments, the data sending device sends a first release message target The first release message may further include a fourth sending module for issuing to the terminal, the first release message comprising: target The suspension configuration information indicates to the terminal to implement an inactive state configuration, whereby the target terminal switches its current state to the inactive state based on the suspension configuration information.

[0397] In some embodiments, the suspension configuration information includes full inactive state terminal identification information, shortened inactive state terminal identification information, radio paging period, radio notification area information, timers, next hop chaining count values, and mobile terminated small data transmission configuration information.

[0398] In some embodiments, the full inactive state terminal identity and the shortened inactive state terminal identity are radio network temporary identifier values ​​of the terminal in the inactive state, and are used by the target network side to find the anchor point node before the terminal entered the inactive state and the access stratum context information stored by the anchor point node, and the full inactive state terminal identity and the shortened inactive state terminal identity have different sizes.

[0399] The above radio paging cycle refers to the RAN paging cycle configured by the RAN side node for the terminal in an inactive state.

[0400] The above-mentioned radio notification area information includes a cell list and a radio area configuration list. as A list of configured cells, the radio area configuration list includes the RAN area code or the RA code of the RAN area.

[0401] The above timer is used to trigger the periodic RNAU process in the terminal.

[0402] The above next-hop chaining count value is used to calculate the security key after the connection is resumed.

[0403] The above configuration information for Mobile Terminated Small Data Transmission is Mobile Terminated Data Resource Bearer (DRB) list for small data transmission or Mobile Terminated and at least one of a signaling radio bearer 2 (SRB2) indication of small data transmission; Mobile Terminated The DRB list for small data transmission indicates the DRB identifiers of the small data transmission configuration; Mobile Terminated The SRB2 indication for small data transmission indicates whether or not SRB2 is present in the small data transmission configuration of the terminal.

[0404] In some embodiments, the above configuration information for mobile terminated small data transmission is a configured grant (CG) configuration. Committed love The CG configuration information further includes information about a CG SSB RSRP threshold, a CG timing advance timer, a CG timing advance verification configuration, and a CG RSRP variation threshold.

[0405] The above CG SSB RSRP threshold is the RSRP threshold selected by the SSB that performs small data transmission based on the CG resource.

[0406] The CG timing advance timer mentioned above is used for timing synchronization of small data transmissions.

[0407] The above CG timing advance verification configuration is used for the RSRP-based TA verification configuration.

[0408] The above CG RSRP fluctuation threshold is the RSRP threshold for TA verification of small data transmission.

[0409] In some embodiments, the data transmission device may further comprise a broadcast module used to broadcast a system message, the system message including at least one of downlink transmission frequency information, an initial downlink BWP, BCCH configuration information, or PCCH configuration information.

[0410] In some embodiments, the downlink transmission frequency information is used to indicate the transmission frequency of the downlink small data packet.

[0411] The initial downlink BWP configuration above is the initial downlink BWP configuration of the primary cell.

[0412] The above BCCH configuration information is a configuration related to modifying the passing period of system messages.

[0413] The above PDCCH configuration information includes a default paging cycle, a paging frame number and configuration, the number of paging occasions, and a first PDCCH monitoring occasion, where the default paging cycle is the default paging cycle broadcast in a system message, the paging frame number and configuration are used to derive the total number of paging frames and the paging frame offset, the number of paging occasions is used to indicate the number of paging occasions in each paging frame, the paging occasion is a group of PDCCH monitoring occasions consisting of multiple time slots for sending paging control information, and the first PDCCH monitoring occasion is the first PDCCH monitoring occasion for indicating that the paging occasion of the paging frame is to be monitored.

[0414] In some embodiments, the data transmission device may further include a fourth determination module that determines a default paging cycle as the second time period for sending the paging message.

[0415] In some embodiments, the connection resume request also includes an uplink small data packet.

[0416] The above-mentioned third sending module 1703 can be particularly used for generating feedback information for uplink small data packets and obtaining downlink small data packets when receiving a connection resumption request; and for sending the downlink small data packets and the feedback information to the target terminal.

[0417] In some embodiments, the above data transmission device may further include a fifth sending module used to send a second release message to the target terminal when the transmission of the downlink small data packet is completed, the second release message including instruction information indicating to switch states, whereby the target terminal switches its current state to an inactive state or an idle state based on the instruction information.

[0418] According to the device provided by the embodiment of the present disclosure, when the target terminal receives a paging message including a paging record designated by the target network device when the target terminal is in an inactive state, a connection resumption request can be sent to the target network device to trigger a small data transmission process between the target terminal and the target network device when the terminal is in an inactive state. At this time, the target network device can send a downlink small data packet to the target terminal based on the received connection resumption request, and the target terminal also receives the downlink small data packet, thereby realizing the downlink small data packet transmission process of the terminal in an inactive state.

[0419] Furthermore, compared with related technologies in which a terminal in an inactive state must switch to a connected state for data transmission, the embodiment of the present disclosure introduces a new terminal access type, namely, mobile-terminated small data transmission, through a mobile-terminated small data transmission indication in a designated paging record, so that the terminal can receive downlink small data packets sent by a target network device when in an inactive state. The signaling overhead and delay consumption caused by switching from an inactive state to a connected state are avoided, the transmission efficiency of downlink small data packets is improved, and the signaling overhead of downlink small data packets is saved, thereby effectively reducing the signaling overhead and delay consumption in the data transmission process.

[0420] Based on the same inventive concept as the above data transmission method provided by the embodiment of the present disclosure, the embodiment of the present disclosure also provides a data transmission system. As shown in Figure 18, Figure 18 is a second schematic structural diagram of the data transmission system provided by the embodiment of the present disclosure. The system shown in Figure 18 includes a target terminal 1801 and a target network device 1802.

[0421] The above target terminal 1801 is used to implement the above methods shown in FIGS.

[0422] The target network device 1802 is used to implement the above-described methods illustrated in FIGS.

[0423] According to the system provided by the embodiment of the present disclosure, when the target terminal receives a paging message including a paging record designated by the target network device when the target terminal is in an inactive state, a connection resumption request can be sent to the target network device to trigger a small data transmission process between the target terminal and the target network device when the terminal is in an inactive state. At this time, the target network device can send a downlink small data packet to the target terminal based on the received connection resumption request, and the target terminal also receives the downlink small data packet, thereby realizing the downlink small data packet transmission process of the terminal in an inactive state.

[0424] Furthermore, compared with related technologies in which a terminal in an inactive state must switch to a connected state for data transmission, the embodiment of the present disclosure introduces a new terminal access type, namely, mobile-terminated small data transmission, through a mobile-terminated small data transmission indication in a designated paging record, so that the terminal can receive downlink small data packets sent by a target network device when in an inactive state. The signaling overhead and delay consumption caused by switching from an inactive state to a connected state are avoided, the transmission efficiency of downlink small data packets is improved, and the signaling overhead of downlink small data packets is saved, thereby effectively reducing the signaling overhead and delay consumption in the data transmission process.

[0425] Based on the same inventive concept as the above data transmission method provided by the embodiment of the present disclosure, the embodiment of the present disclosure also provides a target terminal. As shown in Fig. 19, the target terminal includes a processor 1901, a communication interface 1902, a memory 1903, and a communication bus 1904. The processor 1901, the communication interface 1902, and the memory 1903 communicate with each other via the communication bus 1904.

[0426] The memory 1903 is used to store computer programs.

[0427] When the processor 1901 executes the computer program stored in the memory 1903, it is used to perform the following steps: receiving a paging message issued by the target network device in accordance with a first time period when the current state of the target terminal is an inactive state; sending a connection resumption request to the target network device when the received paging message includes a designated paging record of the target terminal, whereby the target network device sends a downlink small data packet to the target terminal based on the received connection resumption request, where the designated paging record includes a mobile-terminated small data transmission instruction and the connection resumption reason in the connection resumption request is mobile-terminated small data transmission; and receiving the downlink small data packet sent by the target network device.

[0428] Based on the same inventive concept as the above data transmission method provided by the embodiment of the present disclosure, the embodiment of the present disclosure also provides a target network device. As shown in Fig. 20, the target terminal includes a processor 2001, a communication interface 2002, a memory 2003, and a communication bus 2004. The processor 2001, the communication interface 2002, and the memory 2003 communicate with each other via the communication bus 2004.

[0429] The memory 2003 is used to store computer programs.

[0430] When the processor 2001 executes the computer program stored in the memory 2003, it is used to perform the following steps: issuing a paging message to a target terminal in accordance with a second time period, the target terminal being in an inactive state; receiving a connection resumption request sent by the target terminal, the connection resumption request being sent by the target terminal upon receiving a paging message including a designated paging record of the target terminal itself, the designated paging record including a mobile-terminated small data transmission instruction, and the connection resumption reason in the connection resumption request being mobile-terminated small data transmission; and sending a downlink small data packet to the target terminal based on the connection resumption request so that the target terminal receives the downlink small data packet.

[0431] According to the aspects of the target terminal and the target network device provided by the embodiment of the present disclosure, when the target terminal receives a paging message including a paging record designated for the target terminal itself sent by the target network device while the target terminal is in an inactive state, a connection resumption request can be sent to the target network device to trigger a small data transmission process between the target terminal and the target network device when the terminal is in an inactive state. At this time, the target network device can send a downlink small data packet to the target terminal based on the received connection resumption request, and the target terminal also receives the downlink small data packet, thereby realizing the downlink small data packet transmission process of the terminal in an inactive state.

[0432] Furthermore, compared with related technologies in which a terminal in an inactive state must switch to a connected state for data transmission, the embodiment of the present disclosure introduces a new terminal access type, namely, mobile-terminated small data transmission, through a mobile-terminated small data transmission indication in a designated paging record, so that the terminal can receive downlink small data packets sent by a target network device when in an inactive state. The signaling overhead and delay consumption caused by switching from an inactive state to a connected state are avoided, the transmission efficiency of downlink small data packets is improved, and the signaling overhead of downlink small data packets is saved, thereby effectively reducing the signaling overhead and delay consumption in the data transmission process.

[0433] The communication buses of the target terminal and target network device mentioned above may be Peripheral Component Interconnect (PCI) buses or Extended Industry Standard Architecture (EISA) buses, etc. The communication buses can be divided into address buses, data buses, control buses, etc. For convenience of illustration, the buses are represented by only bold lines in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0434] The communication interface is used for communication between the target terminal and the target network device and other devices.

[0435] The memory may include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk memory. In some embodiments, the memory may also be at least one storage device located remotely from the processor.

[0436] The processor may be a general-purpose processor having a central processing unit (CPU) or network processor (NP), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component.

[0437] Based on the same inventive concept as the above data transmission method provided by the embodiments of the present disclosure, the embodiments of the present disclosure also provide a computer-readable storage medium having stored thereon a computer program that, when executed by a processor, performs the steps of the data transmission method of any of the above embodiments.

[0438] Based on the same inventive concept, according to the above data transmission methods provided by the embodiments of the present disclosure, the embodiments of the present disclosure also provide a computer program product including instructions that, when executed on a computer, cause the computer to implement any of the data transmission methods of the above embodiments.

[0439] The above embodiments may be implemented entirely or partially in software, hardware, firmware, or any combination thereof. When implemented in software, the embodiments may be implemented entirely or partially in the form of a computer program product. A computer program product includes one or more computer instructions. When loaded and executed on a computer, the computer program instructions completely or partially generate processes or functions according to embodiments of the present disclosure. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored on a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, radio, microwave, etc.) methods. A computer-readable storage medium may be any available medium accessible by a computer or by a data storage device, such as a server or data center, including one or more available media integrations. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid state disks (SSDs)).

[0440] It should be noted that relationship terms such as "first" and "second" used herein are used merely to distinguish one entity or operation from another and do not necessarily require or imply any actual relationship or order between those entities or operations. Furthermore, the terms "comprising," "containing," or any other variant thereof, are intended to cover non-exclusive inclusions, whereby a process, method, item, or device comprising a set of elements includes not only those elements but also other elements not expressly listed or elements inherent in such process, method, item, or device. Absent further limitations, an element defined by the phrase "comprising" does not exclude that additional identical elements are also present in the process, method, item, or device that comprises the element.

[0441] Various embodiments in this specification are described in a related manner, and the same or similar parts of various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for embodiments such as an apparatus, a system, a target terminal, a target network device, a computer-readable storage medium, and a computer program product, since these are substantially similar to method embodiments, the description thereof can be relatively simple, and the relevant parts can be referred to in the description of the method embodiments.

[0442] The above-mentioned are only preferred embodiments of the present disclosure and do not limit the scope of protection of the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present disclosure shall be included in the scope of protection of the present disclosure.

Claims

1. A data transmission method applied to a target terminal, comprising: receiving a paging message issued by a target network device in response to a first time period when a current state of the target terminal is an inactive state; sending a connection resumption request to the target network device when the received paging message includes a designated paging record for the target terminal, so that the target network device sends a downlink small data packet to the target terminal based on the received connection resumption request, the designated paging record including a mobile terminated small data transmission indication, and a connection resumption reason in the connection resumption request being mobile terminated small data transmission; receiving the downlink small data packet sent by the target network device; A data transmission method including:

2. 2. The data transmission method according to claim 1, wherein the paging message includes a paging record list, which is a list for recording terminals to be paged, and the paging record list includes at least one paging record.

3. the paging record includes at least one of a terminal identification information of the terminal to be paged, an access type, or the mobile terminated small data transmission instruction; the terminal identity information includes a NAS identity (ID) assigned to the terminal by a non-access stratum (NAS) for core network paging and a complete inactive state terminal identity for radio access network (RAN) paging; The access type is used to indicate whether the paging message is a paging message initiated by a Protocol Data Unit (PDU) session that is not accessed by a Third Generation Partnership Project (3GPP); and The data transmission method of claim 2 , wherein the mobile-terminated small data transmission indication is used to indicate that the paging message is used to trigger a mobile-terminated small data transmission.

4. 3. The data transmission method of claim 2, wherein the paging record further includes a contention-free access preamble that indicates to the terminal to initiate a contention-free random access.

5. After receiving the paging message issued by the target network device according to the first time period, the data transmission method includes: parsing each paging record in the received paging message; For each paging record obtained by analysis, determining that the paging record is the designated paging record for the target terminal if the completely inactive state terminal identification information in the paging record matches the completely inactive state terminal identification information stored by the target terminal and the paging record includes the mobile terminated small data transmission indication; determining that the paging record is not the designated paging record of the target terminal when the completely inactive state terminal identification information in the paging record does not match the completely inactive state terminal identification information stored by the terminal and / or when the paging record does not include the mobile terminated small data transmission indication; The data transmission method according to claim 3 , comprising:

6. If the target terminal stores configured grant (CG) configuration information, sending a connection resumption request to the target network device when the received paging message includes a designated paging record of the target terminal; 6. The data transmission method according to claim 1, further comprising: sending the connection resumption request to the target network device based on the CG configuration information when the received paging message includes the designated paging record of the target terminal.

7. If the target terminal does not store configured grant (CG) configuration information, sending a connection resumption request to the target network device when the received paging message includes a designated paging record of the target terminal; When the received paging message includes the designated paging record of the target terminal and the designated paging record does not include a contention-free access preamble, sending the connection resumption request to the target network device in a contention access method; When the received paging message includes the designated paging record of the target terminal, and the designated paging record includes the contention-free access preamble, sending the connection resumption request to the target network device in a contention-free access method; 7. The data transmission method according to claim 1, comprising:

8. Before sending the connection resumption request to the target network device, the data transmission method includes: determining whether the target terminal currently satisfies a preset connection initiation condition, wherein the preset connection initiation condition is that the mobile-terminated small data transmission indication is received, or the preset connection initiation condition is that the mobile-terminated small data transmission indication is received and a downlink reference signal received power (RSRP) is greater than a preset threshold; When the target terminal satisfies the preset connection initiation condition, sending the connection resumption request to the target network device; The data transmission method according to claim 1 , further comprising:

9. 9. The data transmission method according to claim 1, further comprising: sending another connection resume request when another preset connection initiation condition is met, whereby the target terminal sends an uplink data packet to the target network device after the connection corresponding to the another connection resume request is resumed, wherein the another preset connection initiation condition is that a data volume of a radio bearer configured for mobile-originated small data transmission is less than a preset data volume threshold, or the data volume of the radio bearer configured for mobile-origination is less than the preset data volume threshold and uplink small data transmission resources are available.

10. 9. The data transmission method of claim 8, wherein the preset connection initiation condition is expressed as: the mobile terminated small data transmission indication is received; or the mobile terminated small data transmission indication is received and a lower layer below the RRC layer indicates that a trigger condition for small data transmission is met.

11. 10. The data transmission method of claim 9, wherein the preset connection start condition is expressed as: an upper layer above a radio resource control (RRC) layer requests resumption of an RRC connection; SIB1 includes a common configuration for small data transmission; a small data transmission configuration is configured; all uplink small data is mapped to radio bearers of the small data transmission configuration; and a lower layer below the RRC layer indicates that a trigger condition for small data transmission is met.

12. Starting a timer for detecting a resumption process of small data transmission in the inactive state when the target terminal satisfies the preset connection initiation condition; 11. The data transmission method according to claim 8 or 10, further comprising: starting a timer for monitoring an inactivity state resumption process and for sending a timeout indication to a MAC entity when the target terminal does not satisfy the preset connection start condition, wherein the timeout indication is used to indicate a timeout of a configured grant (CG) timing advance timer in CG configuration information for small data transmission.

13. 2. The data transmission method of claim 1, further comprising: releasing stored configured grant (CG) configuration information when the target terminal moves from a current radio access network (RAN) cell to another RAN cell and initiates a connection resumption process in the other RAN cell.

14. the connection resumption request is a first connection resumption request or a second connection resumption request, Sending a connection resumption request to the target network device includes: selecting the first connection resume request as the connection resume request when an SIB1 sent by a base station indicates that the connection resume request uses a full restart identifier, or selecting the second connection resume request as the connection resume request when the received SIB1 does not indicate the use of the full restart identifier; Restoring preset security information from stored access stratum context information, the preset security information including a radio resource control (RRC) configuration, a robust header compression (ROHC) state, a stored mapping relationship between a quality of service (QoS) flow and a data resource bearer (DRB), a base station root key, and an integrity protection key; reconstructing a Packet Data Convergence Protocol (PDCP) entity of the SIB1; Restoring the SIB1; recovering, for each radio bearer configured for mobile terminated small data transmission, a configuration associated with a primary cell group and a Radio Link Layer Control Protocol (RLC) bearer of a PDCP configuration from the access stratum context information; resuming all said radio bearers configured for mobile terminated small data transmission; sending the connection resumption request to the target network device; The data transmission method of claim 1 , comprising:

15. the first connection resumption request and the second connection resumption request each include a resumption identifier, a resumption integrity check code, and the connection resumption reason; the resumption identifier of the first connection resumption request is a full inactive state terminal identity stored by the target terminal, the resumption identifier of the second connection resumption request is a shortened inactive state terminal identity stored by the target terminal, the full inactive state terminal identity and the shortened inactive state terminal identity are radio network temporary identifier values ​​of the terminal in the inactive state and are used by a target network side to find an anchor point before the terminal entered the inactive state and the access stratum context information stored by the anchor point, the full inactive state terminal identity and the shortened inactive state terminal identity have different sizes; and 15. The data transmission method according to claim 14, wherein the restart integrity check code is an identity authentication token for terminal identity authentication at the base station.

16. When the current state of the target terminal is a connected state, the data transmission method includes: receiving a first release message issued by the target network device, the first release message including suspension configuration information indicating that an inactive state configuration is to be implemented for a terminal; switching the current state to the inactive state based on the suspension configuration information; The data transmission method according to any one of claims 1 to 15, further comprising:

17. 17. The data transmission method of claim 16, wherein the suspension configuration information includes complete inactive state terminal identification information, shortened inactive state terminal identification information, a radio paging cycle, radio notification area information, a timer, a next-hop chaining count value, and configuration information for mobile terminated small data transmission.

18. the complete inactive state terminal identity information and the shortened inactive state terminal identity information are radio network temporary identifier values ​​of the terminal in the inactive state, and are used by a target network side to find an anchor point node before the terminal entered the inactive state and access stratum context information stored by the anchor point node, and the complete inactive state terminal identity information and the shortened inactive state terminal identity information have different sizes; the radio paging cycle is a radio access network (RAN) paging cycle configured by a RAN side node for the terminal in the inactive state; The radio notification area information includes a cell list and a radio area configuration list, the cell list being a list of cells configured in a RAN area, and the radio area configuration list including a RAN area code or a random access (RA) code of the RAN area; the timer is used to trigger a periodic RAN-based notification area update (RNAU) process in the terminal; The next-hop chaining count value is used to calculate a security key after the connection is resumed; and The data transmission method of claim 17, wherein the mobile-terminated small data transmission configuration information includes at least one of a data resource bearer (DRB) list for small data transmission or a signaling radio bearer 2 (SRB2) indication for small data transmission, the DRB list for small data transmission indicating a DRB identifier for the small data transmission configuration, and the SRB2 indication for small data transmission indicating the presence or absence of an SRB2 in the small data transmission configuration of the terminal.

19. The mobile terminated small data transmission configuration information further includes configured grant (CG) configuration information, and the CG configuration grant information includes a CG SSB RSRP threshold, a CG timing advance timer, a CG timing advance verification configuration, and a CG RSRP variation threshold; The CG SSB RSRP threshold is a reference signal received power (RSRP) threshold selected by an SSB that performs small data transmission based on CG resources; The CG timing advance timer is used for timing synchronization of small data transmission; The CG timing advance verification configuration is used for configuring RSRP-based timing advance (TA) verification; and The data transmission method according to claim 17 , wherein the CG RSRP fluctuation threshold is an RSRP threshold for TA verification of small data transmission.

20. switching the current state to the inactive state based on the suspension configuration information Resetting the Medium Access Control (MAC) and releasing the default MAC cell group configuration; applying the suspension configuration information; When the suspension configuration information includes CG configuration information, determining each DRB in the DRB list for small data transmission and an SRB2 indication for small data transmission as a DRB and SRB2 in the process of small data transmission, reconstructing a Radio Link Layer Control Protocol (RLC) entity for each RLC bearer in the target terminal configuration, triggering a Packet Data Convergence Protocol (PDCP) entity to perform a Session Data Unit (SDU) discard process for the resumed SRB2 and SRB1, and indicating to a MAC entity to configure CG resources for small data transmission and start a CG timing advance timer; a current access stratum root key (KgNB) and integrity protection key (KRRCint) for radio resource control (RRC) signaling; a robust header compression (ROHC) state; a stored mapping rule between a quality of service (QoS) flow and a data resource bearer (DRB); a cell-radio network temporary identifier (C-RNTI) used in a source primary cell (PCell); a cell identifier and a physical cell identifier of the source PCell; a special cell (SpCell) common configuration in a synchronous reconfiguration message of a new radio primary secondary cell (NR PSCell); parameters in a synchronous reconfiguration message of the PCell; parameters in the synchronous reconfiguration message of the NR PSCell; Storing all the other configuration parameters except for mobility control information of a secondary cell group (SCG) of a PSCell, a primary secondary cell (PSCell) configuration of an EN-DC, and a serving cell common configuration SIB of access stratum context information of the inactive terminal; Suspending all SRBs except SRB0 and DRB; Indicating that all lower layers of the DRB implement PDCP suspension, the lower layers being below the RRC layer; and switching to the inactive state and performing cell reselection; 20. The data transmission method according to any one of claims 16 to 19, comprising:

21. 21. The data transmission method of claim 1, further comprising receiving a system message broadcast by the target network device, the system message including at least one of downlink transmission frequency information, an initial downlink bandwidth portion (BWP), a Broadcast Control Channel (BCCH) configuration information, or a Paging Channel (PCCH) configuration information.

22. the downlink transmission frequency information is used to indicate a transmission frequency of the downlink small data packet; the initial downlink BWP is an initial downlink BWP configuration of a primary cell; the BCCH configuration information is a configuration related to modifying a passing period of the system message; 22. The data transmission method of claim 21, wherein the PDCCH configuration information includes a default paging cycle, a paging frame number and configuration, a number of paging occasions, and a first physical downlink control channel (PDCCH) monitoring occasion, the default paging cycle being a default paging cycle broadcast in the system message, the paging frame number and configuration being used to derive a total number of paging frames and a paging frame offset, the number of paging occasions being used to indicate the number of paging occasions in each paging frame, the paging occasions being a group of PDCCH monitoring occasions consisting of a plurality of time slots for sending paging control information, and the first PDCCH monitoring occasion being a first PDCCH monitoring occasion indicating monitoring a paging occasion of a paging frame.

23. 23. The data transmission method of claim 22, further comprising: when the target terminal is in the inactive state, determining a smaller value of a radio paging cycle and the default paging cycle as the first time period for receiving the paging message, wherein the radio paging cycle is a radio access network (RAN) paging cycle configured by a RAN side node for the terminal in the inactive state.

24. the connection resumption request further includes an uplink small data packet; receiving a downlink small data packet sent by the target network device; 24. The data transmission method according to claim 1, comprising receiving the downlink small data packet sent by the target network device and feedback information sent by the target network device in response to the uplink small data packet.

25. receiving a second release message sent by the target network device when transmission of the downlink small data packet is completed, the second release message including instruction information indicating to switch states; switching the current state to the inactive state or the idle state based on the instruction information; 25. The data transmission method according to any one of claims 1 to 24, further comprising:

26. A data transmission method applied to a target network device, comprising: issuing a paging message to a target terminal in response to a second time period, the target terminal having a current state of inactivity; receiving a connection resumption request sent by the target terminal, the connection resumption request being sent by the target terminal upon receiving the paging message including a designated paging record of the target terminal itself, the designated paging record including a mobile terminated small data transmission indication, and a connection resumption reason in the connection resumption request being mobile terminated small data transmission; sending a downlink small data packet to the target terminal based on the connection resumption request so that the target terminal receives the downlink small data packet; A data transmission method, including:

27. 27. The data transmission method according to claim 26, wherein the paging message includes a paging record list, which is a list for recording terminals to be paged, and the paging record list includes at least one paging record.

28. the paging record includes at least one of a terminal identification information of the terminal to be paged, an access type, or the mobile terminated small data transmission instruction; the terminal identity information includes a NAS identity (ID) assigned to the terminal by a non-access stratum (NAS) for core network paging and a complete inactive state terminal identity for radio access network (RAN) paging; The access type is used to indicate whether the paging message is a paging message initiated by a Protocol Data Unit (PDU) session that is not accessed by a Third Generation Partnership Project (3GPP); and 28. The data transmission method of claim 27, wherein the mobile-terminated small data transmission indication is used to indicate that the paging message is used to trigger a mobile-terminated small data transmission.

29. 28. The data transmission method of claim 27, wherein the paging record further includes a contention-free access preamble indicating to the terminal to initiate a contention-free random access.

30. 30. The data transmission method according to claim 26, wherein the connection resumption request is a first connection resumption request or a second connection resumption request, the first connection resumption request being sent by the target terminal when an SIB1 sent by a base station indicates that the connection resumption request uses a full resumption identifier, and the second connection resumption request being sent by the target terminal when the SIB1 sent by the base station does not indicate that the connection resumption request uses a full resumption identifier.

31. the first connection resumption request and the second connection resumption request each include a resumption identifier, a resumption integrity check code, and the connection resumption reason; the resumption identifier of the first connection resumption request is a full inactive state terminal identity stored by the target terminal, the resumption identifier of the second connection resumption request is a shortened inactive state terminal identity stored by the target terminal, the full inactive state terminal identity and the shortened inactive state terminal identity are radio network temporary identifier values ​​of the terminal in the inactive state and are used by a target network side to find an anchor point before the terminal entered the inactive state and the access stratum context information stored by the anchor point, the full inactive state terminal identity and the shortened inactive state terminal identity have different sizes; and 31. The data transmission method according to claim 30, wherein the restart integrity check code is an identity authentication token for terminal identity authentication at the base station.

32. 32. The data transmission method according to claim 26, further comprising: issuing a first release message to the terminal, wherein the first release message includes suspension configuration information indicating that the target terminal is to perform an inactive state configuration on the terminal such that the target terminal switches the current state to the inactive state based on the suspension configuration information.

33. 33. The data transmission method of claim 32, wherein the suspension configuration information includes complete inactive state terminal identification information, shortened inactive state terminal identification information, a radio paging cycle, radio notification area information, a timer, a next-hop chaining count value, and configuration information for mobile terminated small data transmission.

34. the complete inactive state terminal identity information and the shortened inactive state terminal identity information are radio network temporary identifier values ​​of the terminal in the inactive state, and are used by a target network side to find an anchor point node before the terminal entered the inactive state and access stratum context information stored by the anchor point node, and the complete inactive state terminal identity information and the shortened inactive state terminal identity information have different sizes; the radio paging cycle is a radio access network (RAN) paging cycle configured by a RAN side node for the terminal in the inactive state; The radio notification area information includes a cell list and a radio area configuration list, the cell list being a list of cells configured in a RAN area, and the radio area configuration list including a RAN area code or a random access (RA) code of the RAN area; the timer is used to trigger a periodic RAN-based notification area update (RNAU) process in the terminal; The next-hop chaining count value is used to calculate a security key after the connection is resumed; and The data transmission method of claim 33, wherein the configuration information for the mobile terminated small data transmission includes at least one of a data resource bearer (DRB) list for the inactive small data transmission or a signaling radio bearer 2 (SRB2) indication for the small data transmission, wherein the DRB list for the inactive small data transmission indicates a DRB identifier for the small data transmission configuration, and the SRB2 indication for the small data transmission indicates the presence or absence of an SRB2 for the small data transmission configuration of the terminal.

35. The mobile terminated small data transmission configuration information further includes configured grant (CG) configuration information, and the CG configuration grant information includes a CG SSB RSRP threshold, a CG timing advance timer, a CG timing advance verification configuration, and a CG RSRP variation threshold; The CG SSB RSRP threshold is a reference signal received power (RSRP) threshold selected by an SSB that performs small data transmission based on CG resources; The CG timing advance timer is used for timing synchronization of small data transmission; The CG timing advance verification configuration is used for configuring RSRP-based timing advance (TA) verification; and The data transmission method of claim 34 , wherein the CG RSRP variation threshold is an RSRP threshold for TA verification of small data transmission.

36. 36. The data transmission method of claim 26, further comprising broadcasting a system message, the system message including at least one of downlink transmission frequency information, an initial downlink bandwidth portion (BWP), a Broadcast Control Channel (BCCH) configuration information, or a Paging Channel (PCCH) configuration information.

37. the downlink transmission frequency information is used to indicate a transmission frequency of the downlink small data packet; the initial downlink BWP is an initial downlink BWP configuration of a primary cell; the BCCH configuration information is a configuration related to modifying a passing period of the system message; 37. The data transmission method of claim 36, wherein the PDCCH configuration information includes a default paging cycle, a paging frame number and configuration, a number of paging occasions, and a first physical downlink control channel (PDCCH) monitoring occasion, the default paging cycle being a default paging cycle broadcast in the system message, the paging frame number and configuration being used to derive a total number of paging frames and a paging frame offset, the number of paging occasions being used to indicate the number of paging occasions in each paging frame, the paging occasions being a group of PDCCH monitoring occasions consisting of a plurality of time slots for sending paging control information, and the first PDCCH monitoring occasion being a first PDCCH monitoring occasion indicating monitoring a paging occasion of a paging frame.

38. 38. The data transmission method of claim 37, further comprising determining the default paging cycle as the second time period for sending the paging message.

39. the connection resumption request further includes an uplink small data packet; sending a downlink small data packet to the target terminal based on the connection resumption request, generating feedback information for the uplink small data packet and obtaining the downlink small data packet when receiving the connection resumption request; sending the downlink small data packet and the feedback information to the target terminal; 39. A data transmission method according to any one of claims 26 to 38, comprising:

40. 40. The data transmission method of claim 26, further comprising: sending a second release message to the target terminal when transmission of the downlink small data packet is completed, the second release message including instruction information indicating that the target terminal should switch states based on the instruction information so as to switch the current state to the inactive state or the idle state.

41. A data transmission device applied to a target terminal, a first receiving module for receiving a paging message issued by a target network device according to a first time period when a current state of the target terminal is an inactive state; a first sending module for sending a connection resume request to the target network device when the received paging message includes a designated paging record of the target terminal, so that the target network device sends a downlink small data packet to the target terminal based on the received connection resume request, the designated paging record including a mobile terminated small data transmission indication, and a connection resumption reason in the connection resume request is mobile terminated small data transmission; a second receiving module for receiving the downlink small data packet sent by the target network device; A data transmission device comprising:

42. 42. The data transmission device according to claim 41, wherein the paging message includes a paging record list, which is a list for recording terminals to be paged, and the paging record list includes at least one paging record.

43. the paging record includes at least one of a terminal identification information of the terminal to be paged, an access type, or the mobile terminated small data transmission instruction; the terminal identity information includes a NAS identity (ID) assigned to the terminal by a non-access stratum (NAS) for core network paging and a complete inactive state terminal identity for radio access network (RAN) paging; The access type is used to indicate whether the paging message is a paging message initiated by a Protocol Data Unit (PDU) session that is not accessed by a Third Generation Partnership Project (3GPP); and 43. The data transmission device of claim 42, wherein the mobile-terminated small data transmission indication is used to indicate that the paging message is used to trigger a mobile-terminated small data transmission.

44. 43. The data transmission device of claim 42, wherein the paging record further includes a contention-free access preamble that indicates to the terminal to initiate contention-free random access.

45. an analysis module for analyzing each paging record in the paging message received after receiving the paging message issued by the target network device according to the first time period; a first determination module for determining, for each paging record obtained by the analysis, that the paging record is the designated paging record of the target terminal if the completely inactive state terminal identification information in the paging record matches the completely inactive state terminal identification information stored by the target terminal and the paging record includes the mobile terminated small data transmission indication; a second determination module for determining that the paging record is not the designated paging record of the target terminal when the completely inactive state terminal identification information in the paging record does not match the completely inactive state terminal identification information stored by the terminal and / or when the paging record does not include the mobile terminated small data transmission indication; 44. The data transmission device of claim 43, further comprising:

46. 46. ​​The data transmission device according to claim 41, wherein the first sending module is specifically used for sending the connection resumption request to the target network device based on configured grant (CG) configuration information when the target terminal stores the CG configuration information and the received paging message includes the designated paging record of the target terminal.

47. 47. The data transmission device according to claim 41, wherein the first sending module is specifically used for sending the connection resume request to the target network device in a contention access method when the received paging message includes the designated paging record of the target terminal and the designated paging record does not include a contention-free access preamble, if the target terminal does not store configured grant (CG) configuration information, and for sending the connection resume request to the target network device in a contention-free access method when the received paging message includes the designated paging record of the target terminal and the designated paging record includes the contention-free access preamble.

48. a determination module for determining whether the target terminal currently satisfies a preset connection initiation condition before sending the connection resumption request to the target network device, wherein the preset connection initiation condition is that the mobile terminated small data transmission indication is received, or the preset connection initiation condition is that the mobile terminated small data transmission indication is received and a downlink reference signal received power (RSRP) is greater than a preset threshold; an implementation module for implementing the step of sending the connection resumption request to the target network device when the target terminal satisfies the preset connection initiation condition; 48. The data transmission device according to any one of claims 41 to 47, further comprising:

49. 49. The data transmission device of claim 41, further comprising an implementation module for sending another connection resume request when another preset connection initiation condition is met, such that the target terminal sends an uplink data packet to the target network device after the connection corresponding to the another connection resume request is resumed, wherein the another preset connection initiation condition is that a data volume of a radio bearer configured for mobile-originated small data transmission is less than a preset data volume threshold, or the another preset connection initiation condition is that the data volume of the radio bearer configured for mobile-originated small data transmission is less than the preset data volume threshold and uplink small data transmission resources are available.

50. The data transmission device of claim 48, wherein the preset connection initiation condition is expressed as the mobile terminated small data transmission indication being received, or the mobile terminated small data transmission indication being received and a lower layer below the RRC layer indicating that a trigger condition for small data transmission is met.

51. 50. The data transmission device of claim 49, wherein the other preset connection start condition is expressed as: an upper layer above a radio resource control (RRC) layer requests resumption of an RRC connection; SIB1 includes a common configuration for small data transmission; a small data transmission configuration is configured; all uplink small data is mapped to a radio bearer of the small data transmission configuration; and a lower layer below the RRC layer indicates that a trigger condition for small data transmission is met.

52. a first initiation module for initiating a timer for detecting a resumption process of small data transmission in the inactive state when the target terminal satisfies the preset connection initiation condition; 51. The data transmission device of claim 48 or 50, further comprising: a second start module for starting a timer for monitoring a resumption process of an inactive state and for sending a timeout indication to a MAC entity when the target terminal does not satisfy the preset connection start condition, wherein the timeout indication is used to indicate a timeout of a configured grant (CG) timing advance timer in CG configuration information for small data transmission.

53. 53. The data transmission device of claim 41, further comprising: a release module for releasing stored configured grant (CG) configuration information when the target terminal moves from a current radio access network (RAN) cell to another RAN cell and initiates a connection resumption process in the other RAN cell.

54. The connection resumption request is a first connection resumption request or a second connection resumption request, and the first sending module: select the first connection resume request as the connection resume request when SIB1 sent by a base station indicates that the connection resume request uses a full restart identifier, or select the second connection resume request as the connection resume request when the received SIB1 does not indicate the use of the full restart identifier; Specifically used to recover preset security information from stored access stratum context information, the preset security information including Radio Resource Control (RRC) configuration, Robust Header Compression (ROHC) state, stored mapping relationships between Quality of Service (QoS) flows and Data Resource Bearers (DRBs), base station root keys, and integrity protection keys; and To reconstruct a Packet Data Convergence Protocol (PDCP) entity of the SIB1, To restore the SIB1, for each radio bearer configured for mobile terminated small data transmission, recovering from the access stratum context information a configuration associated with a primary cell group and a Radio Link Layer Control Protocol (RLC) bearer of a PDCP configuration and reconstructing a PDCP entity for this radio bearer; to resume all said radio bearers configured for mobile terminated small data transmission; and to send the connection resumption request to the target network device; Data transmission device according to any one of claims 41 to 53, of particular use.

55. the first connection resumption request and the second connection resumption request each include a resumption identifier, a resumption integrity check code, and the connection resumption reason; the resumption identifier of the first connection resumption request is a full inactive state terminal identity stored by the target terminal, the resumption identifier of the second connection resumption request is a shortened inactive state terminal identity stored by the target terminal, the full inactive state terminal identity and the shortened inactive state terminal identity are radio network temporary identifier values ​​of the terminal in the inactive state and are used by a target network side to find an anchor point before the terminal entered the inactive state and the access stratum context information stored by the anchor point, the full inactive state terminal identity and the shortened inactive state terminal identity have different sizes; and 55. The data transmission device of claim 54, wherein the restart integrity check code is an identity authentication token for terminal identity authentication at the base station.

56. a third receiving module for receiving a first release message issued by the target network device when the current state of the target terminal is a connected state, the first release message including suspension configuration information indicating that an inactive state configuration is to be implemented for the terminal; a first switching module for switching the current state to the inactive state based on the suspension configuration information; 56. The data transmission device according to any one of claims 41 to 55, further comprising:

57. The data transmission device of claim 56, wherein the suspension configuration information includes complete inactive state terminal identification information, shortened inactive state terminal identification information, radio paging period, radio notification area information, timer, next hop chaining count value, and mobile terminated small data transmission configuration information.

58. the complete inactive state terminal identity information and the shortened inactive state terminal identity information are radio network temporary identifier values ​​of the terminal in the inactive state, and are used by a target network side to find an anchor point node before the terminal entered the inactive state and access stratum context information stored by the anchor point node, and the complete inactive state terminal identity information and the shortened inactive state terminal identity information have different sizes; the radio paging cycle is a radio access network (RAN) paging cycle configured by a RAN side node for the terminal in the inactive state; The radio notification area information includes a cell list and a radio area configuration list, the cell list being a list of cells configured in a RAN area, and the radio area configuration list including a RAN area code or a random access (RA) code of the RAN area; the timer is used to trigger a periodic RAN-based notification area update (RNAU) process in the terminal; The next-hop chaining count value is used to calculate a security key after the connection is resumed; and The data transmission device of claim 57, wherein the configuration information for the mobile terminated small data transmission includes at least one of a data resource bearer (DRB) list for the inactive small data transmission or a signaling radio bearer 2 (SRB2) indication for the small data transmission, wherein the DRB list for the inactive small data transmission indicates a DRB identifier for the small data transmission configuration, and the SRB2 indication for the small data transmission indicates the presence or absence of an SRB2 for the small data transmission configuration of the terminal.

59. The mobile terminated small data transmission configuration information further includes configured grant (CG) configuration information, and the CG configuration grant information includes a CG SSB RSRP threshold, a CG timing advance timer, a CG timing advance verification configuration, and a CG RSRP variation threshold; The CG SSB RSRP threshold is a reference signal received power (RSRP) threshold selected by an SSB that performs small data transmission based on CG resources; The CG timing advance timer is used for timing synchronization of small data transmission; The CG timing advance verification configuration is used for configuring timing advance (TA) verification based on RSRP; 59. The data transmission device according to claim 57 or 58, wherein the CG RSRP fluctuation threshold is an RSRP threshold for TA verification of small data transmission.

60. The first switching module includes: To reset the Medium Access Control (MAC) to release the default MAC cell group configuration, To apply the suspension configuration information: When the suspension configuration information includes CG configuration information, to determine each DRB in the inactive state small data transmission DRB list and a small data transmission SRB2 indication as a DRB and SRB2 in the inactive state small data transmission process, to reconstruct a Radio Link Layer Control Protocol (RLC) entity for each RLC bearer in the target terminal configuration, to trigger a Packet Data Convergence Protocol (PDCP) entity to perform a Session Data Unit (SDU) discard process for the resumed SRB2 and SRB1, to configure a MAC entity with CG resources for small data transmission, and to indicate to a MAC entity to start a CG timing advance timer; a current access stratum root key (KgNB) and integrity protection key (KRRCint) for radio resource control (RRC) signaling; a robust header compression (ROHC) state; a stored mapping rule between a quality of service (QoS) flow and a data resource bearer (DRB); a cell-radio network temporary identifier (C-RNTI) used in a source primary cell (PCell); a cell identifier and a physical cell identifier of the source PCell; a special cell (SpCell) common configuration in a synchronous reconfiguration message of a new radio primary secondary cell (NR PSCell); parameters in a synchronous reconfiguration message of the PCell; parameters in the synchronous reconfiguration message of the NR PSCell; and all other configuration parameters except for mobility control information of a secondary cell group (SCG) of a PSCell, a primary secondary cell (PSCell) configuration of an EN-DC, and a serving cell common configuration SIB of access stratum context information of the inactive terminal; To suspend all SRBs except SRB0 and DRB, It is specifically used to indicate that PDCP suspension is implemented in all DRB lower layers, said lower layers being below the RRC layer, and further to switch to the inactive state and perform cell reselection, A data transmission method according to any one of claims 56 to 59, of particular use.

61. 61. The data transmission device of claim 41, further comprising a fourth receiving module for receiving a system message broadcast by the target network device, the system message including at least one of downlink transmission frequency information, an initial downlink bandwidth portion (BWP), a broadcast control channel (BCCH) configuration information, or a paging channel (PCCH) configuration information.

62. the downlink transmission frequency information is used to indicate a transmission frequency of the downlink small data packet; the initial downlink BWP is an initial downlink BWP configuration of a primary cell; the BCCH configuration information is a configuration related to modifying a passing period of the system message; 62. The data transmission device of claim 61, wherein the PDCCH configuration information includes a default paging cycle, a paging frame number and configuration, a number of paging occasions, and a first physical downlink control channel (PDCCH) monitoring occasion, the default paging cycle being a default paging cycle broadcast in the system message, the paging frame number and configuration being used to derive a total number of paging frames and a paging frame offset, the number of paging occasions being used to indicate the number of paging occasions in each paging frame, the paging occasions being a group of PDCCH monitoring occasions consisting of multiple time slots for sending paging control information, and the first PDCCH monitoring occasion being a first PDCCH monitoring occasion indicating monitoring a paging occasion of a paging frame.

63. 63. The data transmission device of claim 62, further comprising: a third determination module for determining, when the target terminal is in the inactive state, a smaller value of a radio paging cycle and the default paging cycle as the first time period for receiving the paging message, wherein the radio paging cycle is a radio access network (RAN) paging cycle configured by a RAN side node for the terminal in the inactive state.

64. the connection resumption request further includes an uplink small data packet; 64. A data transmission device according to any one of claims 41 to 63, wherein the second receiving module is specifically used for receiving the downlink small data packet sent by the target network device and feedback information sent by the target network device for the uplink small data packet.

65. a fifth receiving module for receiving a second release message sent by the target network device when the transmission of the downlink small data packet is completed, the second release message including instruction information indicating to switch states; 65. The data transmission device of claim 41, further comprising: a second switching module for switching the current state to the inactive state or the idle state based on the instruction information.

66. A data transmission device applied to a target network device, comprising: a second sending module for issuing a paging message to a target terminal in response to a second time period, the target terminal having a current state of inactivity; a sixth receiving module for receiving a connection resumption request sent by the target terminal, the connection resumption request being sent by the target terminal upon receiving the paging message including a designated paging record of the target terminal itself, the designated paging record including a mobile-terminated small data transmission indication, and a connection resumption reason in the connection resumption request being mobile-terminated small data transmission; a third sending module for sending a downlink small data packet to the target terminal based on the connection resumption request, so that the target terminal receives the downlink small data packet; A data transmission device comprising:

67. 67. The data transmission device of claim 66, wherein the paging message includes a paging record list that is a list for recording terminals to be paged, and the paging record list includes at least one paging record.

68. the paging record includes at least one of a terminal identification information of the terminal to be paged, an access type, or the mobile terminated small data transmission instruction; the terminal identity information includes a NAS identity (ID) assigned to the terminal by a non-access stratum (NAS) for core network paging and a complete inactive state terminal identity for radio access network (RAN) paging; The access type is used to indicate whether the paging message is a paging message initiated by a Protocol Data Unit (PDU) session that is not accessed by a Third Generation Partnership Project (3GPP); and 68. The data transmission device of claim 67, wherein the mobile terminated small data transmission indication is used to indicate that the paging message is used to trigger a mobile terminated small data transmission.

69. 69. The data transmission device according to claim 67 or 68, wherein the paging record further includes a contention-free access preamble that indicates to the terminal to initiate contention-free random access.

70. 70. A data transmission device according to any one of claims 66 to 69, wherein the connection resumption request is a first connection resumption request or a second connection resumption request, the first connection resumption request being sent by the target terminal when SIB1 sent by the base station indicates that the connection resumption request uses a full resumption identifier, and the second connection resumption request being sent by the target terminal when SIB1 sent by the base station does not indicate that the connection resumption request uses a full resumption identifier.

71. the first connection resumption request and the second connection resumption request each include a resumption identifier, a resumption integrity check code, and the connection resumption reason; the resumption identifier of the first connection resumption request is a full inactive state terminal identity stored by the target terminal, the resumption identifier of the second connection resumption request is a shortened inactive state terminal identity stored by the target terminal, the full inactive state terminal identity and the shortened inactive state terminal identity are radio network temporary identifier values ​​of the terminal in the inactive state and are used by a target network side to find an anchor point before the terminal entered the inactive state and the access stratum context information stored by the anchor point, the full inactive state terminal identity and the shortened inactive state terminal identity have different sizes; and 71. The data transmission device of claim 70, wherein the restart integrity check code is an identity authentication token for terminal identity authentication at the base station.

72. 72. The data transmission device of claim 66, further comprising: a fourth sending module for issuing a first release message to the terminal, the first release message including suspension configuration information indicating that an inactive state configuration is to be implemented in the terminal, whereby the target terminal switches the current state to the inactive state based on the suspension configuration information.

73. The data transmission device of claim 72, wherein the suspension configuration information includes complete inactive state terminal identification information, shortened inactive state terminal identification information, radio paging period, radio notification area information, timer, next hop chaining count value, and mobile terminated small data transmission configuration information.

74. the complete inactive state terminal identity information and the shortened inactive state terminal identity information are radio network temporary identifier values ​​of the terminal in the inactive state, and are used by a target network side to find an anchor point node before the terminal entered the inactive state and access stratum context information stored by the anchor point node, and the complete inactive state terminal identity information and the shortened inactive state terminal identity information have different sizes; the radio paging cycle is a radio access network (RAN) paging cycle configured by a RAN side node for the terminal in the inactive state; The radio notification area information includes a cell list and a radio area configuration list, the cell list being a list of cells configured in a RAN area, and the radio area configuration list including a RAN area code or a random access (RA) code of the RAN area; the timer is used to trigger a periodic RAN-based notification area update (RNAU) process in the terminal; The next-hop chaining count value is used to calculate a security key after the connection is resumed; and The data transmission device of claim 73, wherein the configuration information for the mobile terminated small data transmission includes at least one of a data resource bearer (DRB) list for the inactive small data transmission or a signaling radio bearer 2 (SRB2) indication for the small data transmission, wherein the DRB list for the inactive small data transmission indicates a DRB identifier for the small data transmission configuration, and the SRB2 indication for the small data transmission indicates the presence or absence of an SRB2 for the small data transmission configuration of the terminal.

75. The mobile terminated small data transmission configuration information further includes configured grant (CG) configuration information, and the CG configuration grant information includes a CG SSB RSRP threshold, a CG timing advance timer, a CG timing advance verification configuration, and a CG RSRP variation threshold; The CG SSB RSRP threshold is a reference signal received power (RSRP) threshold selected by an SSB that performs small data transmission based on CG resources; The CG timing advance timer is used for timing synchronization of small data transmission; The CG timing advance verification configuration is used for configuring RSRP-based timing advance (TA) verification; and The data transmission device of claim 74, wherein the CG RSRP fluctuation threshold is an RSRP threshold for TA verification of small data transmission.

76. 76. The data transmission device of claim 66, further comprising: a broadcast module for broadcasting a system message, the system message including at least one of downlink transmission frequency information, an initial downlink bandwidth portion (BWP), a broadcast control channel (BCCH) configuration information, or a paging channel (PCCH) configuration information.

77. the downlink transmission frequency information is used to indicate a transmission frequency of the downlink small data packet; the initial downlink BWP is an initial downlink BWP configuration of a primary cell; the BCCH configuration information is a configuration related to modifying a passing period of the system message; 77. The data transmission device of claim 76, wherein the PDCCH configuration information includes a default paging cycle, a paging frame number and configuration, a number of paging occasions, and a first physical downlink control channel (PDCCH) monitoring occasion, the default paging cycle being a default paging cycle broadcast in the system message, the paging frame number and configuration being used to derive a total number of paging frames and a paging frame offset, the number of paging occasions being used to indicate the number of paging occasions in each paging frame, the paging occasions being a group of PDCCH monitoring occasions consisting of a plurality of time slots for sending paging control information, and the first PDCCH monitoring occasion being a first PDCCH monitoring occasion indicating monitoring a paging occasion of a paging frame.

78. 78. The data transmission device of claim 77, further comprising a fourth determining module that determines the default paging cycle as the second time period for sending the paging message.

79. The connection resumption request further includes an uplink small data packet, and the third sending module: When receiving the connection resumption request, for generating feedback information for the uplink small data packet and for obtaining the downlink small data packet; and to send the downlink small data packet and the feedback information to the target terminal; Data transmission device according to any one of claims 66 to 78, of particular use.

80. 80. The data transmission device of claim 66, further comprising: a fifth sending module for sending a second release message to the target terminal when transmission of the downlink small data packet is completed, the second release message including instruction information indicating to switch states, whereby the target terminal switches the current state to the inactive state or the idle state based on the instruction information.

81. A target terminal for implementing the data transmission method according to any one of claims 1 to 25; a target network device for implementing the data transmission method according to any one of claims 26 to 40; A data transmission system comprising:

82. a memory for storing a computer program; a processor that executes the computer program stored in the memory to perform the data transmission method of any one of claims 1 to 25; a communication interface; a communication bus, wherein said processor, said communication interface and said memory communicate with each other via said communication bus.

83. a memory for storing a computer program; a processor that executes the computer program stored in the memory to perform the data transmission method of any one of claims 26 to 40; a communication interface; a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus.

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