A data transmission method, device, system, terminal and network equipment

Abstract

The embodiment of the present disclosure provides a data transmission method, device, system, terminal and network equipment. The scheme is as follows: when the current state of the target terminal is the non-activated state, the paging message issued by the target network equipment is received according to the first time period; when the paging message received includes the specified paging record of the target terminal, the connection recovery request is sent to the target network equipment, so that the target network equipment sends the downlink small data packet to the target terminal based on the received connection recovery request, the non-activated state downlink small data transmission indication is included in the specified paging record, and the connection recovery reason in the connection recovery request is the non-activated state downlink small data transmission; the downlink small data packet sent by the target network equipment is received. Through the technical scheme of the embodiment of the present disclosure, the downlink data transmission of the non-activated terminal can be realized, and the signaling overhead and time delay consumption of the data transmission process are reduced.

Description

Technical Field

[0001] This disclosure relates to the field of wireless communication technology, and in particular to a data transmission method, apparatus, system, terminal and network equipment. Background Technology

[0002] In related technologies, to enable User Equipment (UE) to quickly enter the connected state (i.e., RRC_CONNECTED state) for data interaction, and to reduce the signaling overhead caused by UE movement and state transition processes, a new state, namely the inactive state (i.e., RRC_INACTIVE state), has been introduced. In the RRC_INACTIVE state, the UE's Non-Access Stratum (NAS) remains in the connected state, but the air interface connection corresponding to the UE's Access Stratum (AS) is temporarily suspended, similar to the idle state (i.e., RRC_IDLE state).

[0003] Currently, if a UE in RRC_INACTIVE state needs to transmit small data packets, the UE must first switch from RRC_INACTIVE state to RRC_CONNECTED state. This means that a connection must be established between the network's control plane and user plane before data transmission can occur. This process inevitably incurs significant signaling overhead and latency. Summary of the Invention

[0004] The purpose of this disclosure is to provide a data transmission method, apparatus, system, terminal, and network device to enable downlink data transmission from inactive terminals, reducing signaling overhead and latency during data transmission. The specific technical solution is as follows:

[0005] This disclosure provides a data transmission method applied to a target terminal, the method comprising:

[0006] When the target terminal is inactive, it receives paging messages from the target network device according to a first time period.

[0007] When the received paging message includes a specified paging record of the target terminal, a connection recovery request is sent to the target network device so that the target network device sends downlink small data packets to the target terminal based on the received connection recovery request. The specified paging record includes an inactive downlink small data transmission indication, and the connection recovery request indicates that the connection recovery reason is inactive downlink small data transmission.

[0008] Receive downlink small data packets sent by the target network device.

[0009] This disclosure also provides a data transmission method applied to a target network device, the method comprising:

[0010] According to the second time period, a paging message is sent to the target terminal that is currently inactive.

[0011] The connection recovery request is received from the target terminal. The connection recovery request is sent by the target terminal when it receives a paging message that includes its own designated paging record. The designated paging record includes an inactive downlink data transmission indication. The connection recovery reason in the connection recovery request is inactive downlink data transmission.

[0012] Based on the connection restoration request, a downlink small data packet is sent to the target terminal so that the target terminal can receive the downlink small data packet.

[0013] This disclosure also provides a data transmission apparatus for use in a target terminal, the apparatus comprising:

[0014] The first receiving module is configured to receive a paging message sent by the target network device according to a first time period when the current state of the target terminal is inactive.

[0015] The first sending module is configured to send a connection restoration request to the target network device when the received paging message includes a specified 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 restoration request, wherein the specified paging record includes an inactive downlink small data transmission indication, and the connection restoration reason in the connection restoration request is inactive downlink small data transmission;

[0016] The second receiving module is used to receive downlink small data packets sent by the target network device.

[0017] Optionally, the paging message includes a paging record list; the paging record list is a list used to record the paging terminals, and the paging record list includes at least one paging record.

[0018] Optionally, the paging record includes the terminal identifier, access type, and inactive downlink data transmission indication of the paged terminal;

[0019] The terminal identifier includes: a NAS layer identifier (ID) assigned to the terminal by the NAS for core network paging, and a complete inactive terminal identifier for Radio Access Network (RAN) paging; the access type is used to indicate whether the paging message is initiated by a Protocol Data Unit (PDU) session accessed by a non-3rd Generation Partnership Project (3GPP) member; the inactive downlink data transmission indication is used to indicate that the paging message is used to trigger inactive downlink data transmission.

[0020] Optionally, the paging record may also include a non-contention access preamble that instructs the terminal to initiate non-contention random access.

[0021] Optionally, the device further includes:

[0022] The parsing module is used to parse each paging record in the received paging message after receiving the paging message sent by the target network device according to the first time period.

[0023] The first determining module is used to determine that for each parsed paging record, if the complete inactive terminal identifier in the paging record matches the complete inactive terminal identifier stored in the target terminal, and the paging record includes the inactive downlink small data transmission indication, then the paging record is the designated paging record of the target terminal.

[0024] The second determining module is configured to determine that the paging record is not the designated paging record of the target terminal if the complete inactive terminal identifier in the paging record does not match the complete inactive terminal identifier stored in the terminal, and / or the paging record does not include the inactive downlink small data transmission indication.

[0025] Optionally, the first sending module is specifically used to send a connection restoration request to the target network device based on the CG configuration information when the target terminal stores configured grant (CG) configuration information and the received paging message includes a specified paging record of the target terminal.

[0026] Optionally, the first sending module is specifically used to send a connection recovery request to the target network device in a contention access manner if the target terminal does not store CG configuration information, and the received paging message includes a specified paging record of the target terminal, and the specified paging record does not include a non-contention access preamble.

[0027] When the received paging message includes a designated paging record of the target terminal, and the designated paging record includes the non-contention access preamble, a connection recovery request is sent to the target network device via non-contention access.

[0028] Optionally, the device further includes:

[0029] The judgment module is used to determine whether the target terminal meets the preset connection initiation conditions at the current time before sending a connection recovery request to the target network device. The preset connection initiation conditions are: the data volume of the wireless bearer configured for the inactive small data transmission is less than a preset data volume threshold and / or the inactive downlink small data transmission indication is received, the downlink reference signal receiving power (RSRP) is greater than a preset threshold, and the uplink small data transmission resources are valid.

[0030] An execution module is used to execute the step of sending a connection recovery request to the target network device when the target terminal meets the preset connection initiation conditions.

[0031] Optionally, the preset connection initiation condition is expressed as follows: a higher layer above the Radio Resource Control (RRC) layer requests the restoration of the RRC connection, SIB1 contains a common configuration for small data transmission, a small data transmission configuration is configured, all uplink small data are mapped to the radio bearer of the small data transmission configuration and / or an inactive downlink small data transmission indication is received, and a lower layer indication below the RRC layer satisfies the triggering condition for inactive small data.

[0032] Optionally, the device further includes:

[0033] The first startup module is used to start a timer for detecting the recovery process of inactive small data transmission when the target terminal meets the preset connection initiation conditions;

[0034] The device further includes:

[0035] The second startup module is used to start a timer for monitoring the inactive state recovery process when the target terminal does not meet the preset connection initiation conditions, and send a timeout indication to the MAC entity. The timeout indication is used to indicate that the CG timing advance timer in the CG configuration information of the small data transmission has timed out.

[0036] Optionally, the device further includes:

[0037] The release module is used to release the stored CG configuration information if the target terminal moves from the current RAN cell to another RAN cell and initiates a connection recovery process in the other RAN cell.

[0038] Optionally, the connection restoration request may be a first connection restoration request or a second connection restoration request;

[0039] The first sending module is specifically configured to select the first connection recovery request as the connection recovery request when the SIB1 sent by the base station indicates that the connection recovery request uses the full recovery identifier; or, when the received SIB1 does not indicate that the full recovery identifier is used, select the second connection recovery request as the connection recovery request.

[0040] Recover preset security information from the stored access layer context information. The preset security information includes: RRC configuration, Robust Header Compression (ROHC) status, the mapping relationship between the stored Quality of Service (QoS) flow and the Data Radio Bearer (DRB), the base station root key, and the integrity protection key.

[0041] The SIB1 reconstruction of the Packet Data Convergence Protocol (PDCP) entity;

[0042] Restore SIB1;

[0043] For each radio bearer configured for inactive small data transmission, the configuration associated with the Radio Link Control (RLC) bearer configured with the primary cell group and PDCP is recovered from the access layer context information, and the PDCP entity is reconstructed for that radio bearer.

[0044] Restore all radio bearers to their inactive small data transmission configuration;

[0045] The connection restoration request is sent to the target network device.

[0046] Optionally, the first connection recovery request and the second connection recovery request include: a recovery identifier, a recovery integrity check code, and a recovery reason;

[0047] Wherein, the recovery identifier of the first connection recovery request is the complete inactive terminal identifier stored by the target terminal, and the recovery identifier of the second connection request is the truncated inactive terminal identifier stored by the target terminal; the recovery integrity check code is the authentication token used for terminal authentication at the base station; and the recovery reason is the inactive downlink small data transmission.

[0048] Optionally, the device further includes:

[0049] The third receiving module is used to receive a first release message sent by the target network device when the current state of the target terminal is connected. The first release message includes pause configuration information that instructs the terminal to perform inactive state configuration.

[0050] The first switching module is used to switch the current state to an inactive state based on the pause configuration information.

[0051] Optionally, the pause configuration information includes: complete inactive terminal identifier, truncated inactive terminal identifier, wireless paging cycle, wireless notification area information, timer, next-hop chain count value, and inactive small data transmission configuration information.

[0052] Optionally, the complete inactive terminal identifier and the truncated inactive terminal identifier are temporary wireless network identifier values ​​of the inactive terminal, used by the target network side to find the anchor node before the terminal enters the inactive state and the access layer context information stored therein. The complete inactive terminal identifier and the truncated inactive terminal identifier have different sizes.

[0053] The wireless paging cycle is the RAN paging cycle configured by the RAN-side node for the inactive terminal;

[0054] The wireless notification area information includes a cell list and a wireless area configuration list, wherein the cell list is configured as a list of cells in the RAN area, and the wireless area configuration list includes the RAN area code or random access RA code of the RAN area;

[0055] The timer is used to trigger the periodic notification area update (RNAU) process in the terminal;

[0056] The next-hop chain count value is used to calculate the security key after the connection is restored;

[0057] The inactive small data transmission configuration information includes: an inactive small data transmission data resource bearer (DRB) list and a small data transmission signaling radio bearer (SRB2) indication. The inactive small data transmission DRB list indicates the DRB identifier of the small data transmission configuration, and the small data transmission SRB2 indication is used to indicate whether the terminal has an SRB2 configured for small data transmission.

[0058] Optionally, the inactive small data transmission configuration information further includes CG configuration information; wherein, the CG configuration authorization information includes: CG SSB RSRP threshold, CG timing advance timer, CG timing advance verification configuration, and CG RSRP change threshold;

[0059] The CG SSB RSRP threshold is the RSRP threshold for single-sideband SSB selection based on CG resources for small data transmission.

[0060] The CG advance timer is used for timed synchronization of small data transmissions;

[0061] The CG timing advance verification configuration is used for configuring RSRP-based advance (TA) verification;

[0062] The CG RSRP change threshold is the RSRP threshold used for TA verification of small data transmission.

[0063] Optionally, the first switching module is specifically used to reset the Media Access Control (MAC) and release the default MAC cell group configuration;

[0064] Apply the aforementioned pause configuration information;

[0065] When the CG configuration information is included in the pause configuration information, each DRB in the inactive small data transmission DRB list and the small data transmission SRB2 indication are identified as the DRB and SRB2 of the inactive small data transmission process; for each RLC bearer in the target terminal configuration, the RLC entity is rebuilt; for the recovered SRB2 and SRB1, the PDCP entity is triggered to execute the Session Data Unit (SDU) discarding process; small data transmission CG resources are configured for the MAC entity, and the CG timing advance timer is started.

[0066] The current access layer root key KgNB and the integrity protection key KRRCint of RRC signaling, ROHC state, the mapping rules between the stored QoS flow and DRB, the Cell Radio Network Temporary Identifier (C-RNTI) used in the source primary cell (PCell), the cell identifier and the physical cell identifier of the source PCell, the common configuration of the special cell (SpCell) in the synchronization reconfiguration message of the New Radio Primary Secondary Cell (NR PSCell), and all other configuration parameters except those in the synchronization reconfiguration message of the PCell, 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 in EN-DC, and the serving cell common configuration SIB are stored in the inactive terminal access layer context information.

[0067] Suspend all SRBs and DRBs except SRB0;

[0068] Instruct all lower layers of the DRB to pause PDCP, which are located below the RRC layer;

[0069] Switch to the inactive state and perform cell reselection.

[0070] Optionally, the device further includes:

[0071] The fourth receiving module is used to receive system messages broadcast by the target network device. The system messages include downlink transmission frequency information, initial downlink bandwidth part (BWP), broadcast control channel (BCCH) configuration information, and paging channel (PCCH) configuration information.

[0072] Optionally, the downlink transmission frequency information is used to indicate the transmission frequency of downlink small data packets;

[0073] The initial downlink BWP is the initial downlink BWP configuration of the primary cell;

[0074] The BCCH configuration information is a configuration related to modifying the system message transmission cycle;

[0075] The PCCH configuration information includes a default paging period, the number and configuration of paging frames, the number of paging opportunities, and the first Physical Downlink Control Channel (PDCCH) listening opportunity. The default paging period is the default paging period broadcast in the system message. The number and configuration of paging frames are used to derive the total number of paging frames and the paging frame offset. The number of paging opportunities is used to indicate the number of paging opportunities in each paging frame. The paging opportunity is a set of PDCCH listening opportunities, consisting of multiple time slots for sending paging control information. The first PDCCH listening opportunity is the first PDCCH listening opportunity used to listen for paging opportunities in the paging frame.

[0076] Optionally, the device further includes:

[0077] The third determining module is used to determine the smaller value between the wireless paging period and the default paging period as the first time period for receiving paging messages when the target terminal is in an inactive state.

[0078] Optionally, the connection restoration request may also include uplink small data packets;

[0079] The second receiving module is specifically used to receive downlink small data packets sent by the target network device, as well as feedback information sent by the target network device in response to the uplink small data packets.

[0080] Optionally, the device further includes:

[0081] The fifth receiving module is used to receive a second release message sent by the target network device when the downlink small data packet transmission is completed, the second release message including indication information indicating a state switch;

[0082] The second switching module is used to switch the current state to an inactive state or an idle state based on the indication information.

[0083] This disclosure also provides a data transmission apparatus for use in a target network device, the apparatus comprising:

[0084] The second sending module is used to send paging messages to target terminals that are currently inactive, according to a second time period.

[0085] The sixth receiving module is used to receive a connection restoration request sent by the target terminal. The connection restoration request is sent by the target terminal when it receives a paging message that includes its own designated paging record. The designated paging record includes an inactive downlink data transmission indication. The connection restoration reason in the connection restoration request is inactive downlink data transmission.

[0086] The third sending module is used to send downlink small data packets to the target terminal based on the connection restoration request, so that the target terminal can receive the downlink small data packets.

[0087] Optionally, the paging message includes a paging record list; the paging record list is a list used to record the paging terminals, and the paging record list includes at least one paging record.

[0088] Optionally, the paging record includes the terminal identifier, access type, and inactive downlink data transmission indication of the paged terminal;

[0089] The terminal identifier includes: a NAS layer ID assigned to the terminal for core network paging (not assigned by NAS), and a complete inactive terminal identifier for RAN paging; the access type indicates whether the paging message is initiated by a PDU session accessed by a non-3GPP provider; the inactive downlink data transmission indication indicates that the paging message is used to trigger inactive downlink data transmission.

[0090] Optionally, the paging record may also include a non-contention access preamble that instructs the terminal to initiate non-contention random access.

[0091] Optionally, the connection recovery request can be a first connection recovery request or a second connection recovery request; the first connection recovery request is sent by the target terminal when the SIB1 sent by the base station indicates that the connection recovery request uses the full recovery identifier, and the second connection recovery request is sent by the target terminal when the SIB1 sent by the base station does not indicate that the connection recovery request uses the full recovery identifier.

[0092] Optionally, the first connection recovery request and the second connection recovery request include: a recovery identifier, a recovery integrity check code, and a recovery reason;

[0093] Wherein, the recovery identifier of the first connection recovery request is the complete inactive terminal identifier stored by the target terminal, and the recovery identifier of the second connection request is the truncated inactive terminal identifier stored by the target terminal; the recovery integrity check code is the authentication token used for terminal authentication at the base station; and the recovery reason is the inactive downlink small data transmission.

[0094] Optionally, the device further includes:

[0095] The fourth sending module is used to send a first release message to the terminal. The first release message includes pause configuration information that instructs the terminal to perform inactive state configuration, so that the target terminal switches its current state to inactive state based on the pause configuration information.

[0096] Optionally, the pause configuration information includes: complete inactive terminal identifier, truncated inactive terminal identifier, wireless paging cycle, wireless notification area information, timer, next-hop chain count value, and inactive small data transmission configuration information.

[0097] Optionally, the complete inactive terminal identifier and the truncated inactive terminal identifier are temporary wireless network identifier values ​​of the inactive terminal, used by the target network side to find the anchor node before the terminal enters the inactive state and its stored access layer context. The complete inactive terminal identifier and the truncated inactive terminal identifier have different sizes.

[0098] The wireless paging cycle is the RAN paging cycle configured by the RAN-side node for the inactive terminal;

[0099] The wireless notification area information includes a cell list and a wireless area configuration list, wherein the cell list is configured as a list of cells in the RAN area, and the wireless area configuration list includes the RAN area code or RA code of the RAN area;

[0100] The timer is used to trigger the periodic RNAU process in the terminal;

[0101] The next-hop chain count value is used to calculate the security key after the connection is restored;

[0102] The inactive small data transmission configuration information includes: an inactive small data transmission data resource bearer (DRB) list and a small data transmission signaling radio bearer (SRB2) indication. The inactive small data transmission DRB list indicates the DRB identifier of the small data transmission configuration, and the small data transmission SRB2 indication is used to indicate whether the terminal has an SRB2 configured for small data transmission.

[0103] Optionally, the inactive small data transmission configuration information further includes CG configuration information; wherein, the CG configuration authorization information includes: CG SSB RSRP threshold, CG timing advance timer, CG timing advance verification configuration, and CG RSRP change threshold;

[0104] The CG SSB RSRP threshold is the RSRP threshold for single-sideband SSB selection based on CG resources for small data transmission.

[0105] The CG advance timer is used for timed synchronization of small data transmissions;

[0106] The CG timed early verification configuration is used for configuring RSRP-based TA verification;

[0107] The CG RSRP change threshold is the RSRP threshold used for TA verification of small data transmission.

[0108] Optionally, the device further includes:

[0109] The broadcast module is used to broadcast system messages, which include downlink transmission frequency information, initial downlink BWP, BCCH configuration information, and PCCH configuration information.

[0110] Optionally, the downlink transmission frequency information is used to indicate the transmission frequency of downlink small data packets;

[0111] The initial downlink BWP is the initial downlink BWP configuration of the primary cell;

[0112] The BCCH configuration information is a configuration related to modifying the system message transmission cycle;

[0113] The PCCH configuration information includes a default paging period, the number and configuration of paging frames, the number of paging opportunities, and the first PDCCH listening opportunity. The default paging period is the default paging period broadcast in the system message. The number and configuration of paging frames are used to derive the total number of paging frames and the paging frame offset. The number of paging opportunities is used to indicate the number of paging opportunities in each paging frame. The paging opportunity is a set of PDCCH listening opportunities, consisting of multiple time slots for sending paging control information. The first PDCCH listening opportunity is the first PDCCH listening opportunity used to listen for the paging opportunities of the paging frame.

[0114] Optionally, the device further includes:

[0115] The fourth determining module is used to determine the default paging period as the second time period for sending the paging message.

[0116] Optionally, the connection restoration request may also include uplink small data packets;

[0117] The third sending module is specifically used to generate feedback information for the uplink small data and obtain downlink small data packets when the connection restoration request is received;

[0118] The downlink small data packet and the feedback information are sent to the target terminal.

[0119] Optionally, the device further includes:

[0120] The fifth sending module is used to send a second release message to the target terminal when the downlink small data packet transmission is completed. The second release message includes indication information indicating a state switch, so that the target terminal switches its current state to an inactive state or a spatial state based on the indication information.

[0121] This disclosure also provides a data transmission system, the system including a target terminal and a target network device;

[0122] The target terminal is used to execute any of the data transmission methods described above applied to the target terminal;

[0123] The target network device is used to execute any of the data transmission methods described above for the target network device.

[0124] This 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 through the communication bus;

[0125] Memory, used to store computer programs;

[0126] When a processor executes a program stored in memory, it implements any of the data transmission method steps described above.

[0127] This 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 through the communication bus;

[0128] Memory, used to store computer programs;

[0129] When a processor executes a program stored in memory, it implements any of the data transmission method steps described above.

[0130] This disclosure also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements any of the data transmission method steps described above.

[0131] This disclosure also provides a computer program product containing instructions that, when run on a computer, cause the computer to perform any of the data transmission methods described above.

[0132] Beneficial effects of the embodiments disclosed herein:

[0133] The technical solution provided in this disclosure embodiment allows the target terminal to send a connection restoration request to the target network device when the target terminal is in an inactive state. This triggers 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 restoration request. The target terminal also receives the downlink small data packet, thus realizing the downlink small data transmission process of the inactive terminal.

[0134] Furthermore, compared to related technologies where inactive terminals must switch to connected mode to transmit data, this embodiment introduces a new terminal access type, namely inactive downlink small data transmission, by specifying an inactive downlink data transmission indication in the paging record. This allows the terminal to receive downlink small data packets sent by the target network device in an inactive state, avoiding the signaling overhead and latency caused by switching from inactive to connected mode. This improves the transmission efficiency of downlink small data packets and saves signaling overhead, effectively reducing signaling overhead and latency during data transmission.

[0135] Of course, implementing any product or method of this disclosure does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0136] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other embodiments can be obtained based on these accompanying drawings.

[0137] Figure 1 This is a schematic diagram of a first type of data transmission method provided in an embodiment of the present disclosure;

[0138] Figure 2 This is a second flowchart illustrating the data transmission method provided in an embodiment of the present disclosure;

[0139] Figure 3 This is a schematic diagram of a third data transmission method provided in an embodiment of the present disclosure;

[0140] Figure 4 This is a schematic diagram of a fourth data transmission method provided in an embodiment of the present disclosure;

[0141] Figure 5 A fifth flowchart illustrating the data transmission method provided in this embodiment of the disclosure;

[0142] Figure 6 A sixth flowchart illustrating the data transmission method provided in this embodiment of the disclosure;

[0143] Figure 7 A flowchart illustrating a connection restoration request sending method provided in an embodiment of this disclosure;

[0144] Figure 8 A seventh flowchart illustrating the data transmission method provided in this embodiment of the disclosure;

[0145] Figure 9 An eighth flowchart illustrating the data transmission method provided in this embodiment of the disclosure;

[0146] Figure 10 A ninth flowchart illustrating the data transmission method provided in this embodiment of the disclosure;

[0147] Figure 11 A tenth flowchart illustrating the data transmission method provided in this embodiment of the disclosure;

[0148] Figure 12 An eleventh flowchart illustrating a data transmission method provided in an embodiment of this disclosure;

[0149] Figure 13 This is a schematic diagram of the twelfth type of data transmission method provided in the embodiments of this disclosure;

[0150] Figure 14 A schematic diagram of the thirteenth data transmission method provided in this embodiment of the disclosure;

[0151] Figure 15 A signaling diagram for a non-active state data transmission process provided in an embodiment of this disclosure;

[0152] Figure 16 This is a schematic diagram of a first structure of a data transmission device provided in an embodiment of the present disclosure;

[0153] Figure 17 This is a second structural schematic diagram of the data transmission device provided in an embodiment of the present disclosure;

[0154] Figure 18 A schematic diagram of the structure of a data transmission system provided in an embodiment of this disclosure;

[0155] Figure 19 A schematic diagram of the structure of a target terminal provided in an embodiment of this disclosure;

[0156] Figure 20 This is a schematic diagram of the structure of a target network device provided in an embodiment of this disclosure. Detailed Implementation

[0157] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art based on this disclosure are within the scope of protection of this disclosure.

[0158] To address the problems in related technologies, embodiments of this disclosure provide a data transmission method. For example... Figure 1 As shown, Figure 1 This is a schematic diagram of a first type of data transmission method provided in an embodiment of the present disclosure. Figure 1 The method shown is applied to the target terminal and specifically includes the following steps.

[0159] Step S101: When the target terminal is inactive, receive the paging message sent by the target network device according to the first time period.

[0160] Step S102: When the received paging message includes a specified paging record of the target terminal, a connection recovery request is sent to the target network device so that the target network device sends a downlink small data packet to the target terminal based on the received connection recovery request. The specified paging record includes an inactive downlink small data transmission indication, and the connection recovery reason in the connection recovery request is inactive downlink small data transmission.

[0161] Step S103: Receive downlink small data packets sent by the target network device.

[0162] In this embodiment, the target network device can be a base station or other network device accessed by the target terminal, and the target terminal can be any terminal within the network coverage area of ​​the target network device, such as a mobile phone or tablet. Here, no specific limitations are made on the target network device and the target terminal. For ease of understanding, the following description uses a UE as the target terminal and a base station in the 5G core network as the target network device, which is not intended to be limiting.

[0163] pass Figure 1 The method shown allows the target terminal to send a connection restoration request to the target network device when it is in an inactive state. This triggers 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 restoration request. The target terminal will also receive the downlink small data packet, thus realizing the downlink small data transmission process of the inactive terminal.

[0164] Furthermore, compared to related technologies where inactive terminals must switch to connected mode to transmit data, this embodiment introduces a new terminal access type, namely inactive downlink small data transmission, by specifying an inactive downlink data transmission indication in the paging record. This allows the terminal to receive downlink small data packets sent by the target network device in an inactive state, avoiding the signaling overhead and latency caused by switching from inactive to connected mode. This improves the transmission efficiency of downlink small data packets and saves signaling overhead, effectively reducing signaling overhead and latency during data transmission.

[0165] The embodiments of this disclosure will be described below through specific examples.

[0166] Regarding step S101 above, that is, when the current state of the target terminal is inactive, the paging message sent by the target network device is received according to the first time period.

[0167] In this embodiment of the disclosure, during the data service transmission process of the terminal, the terminal can be in three states: connected state (i.e., the RRC_CONNECTED state mentioned above), inactive state (i.e., the RRC_INACTIVE state mentioned above), or idle state (i.e., the RRC_IDLE state mentioned above).

[0168] When any terminal in the network corresponding to the target network device is in the aforementioned inactive state, the target network device itself cannot detect the inactive state. Therefore, the target network device will consider the terminal to be in a connected state. The target network device can send paging messages to the target terminals it considers to be in a connected state according to a preset time period (denoted as the second time period). Correspondingly, the target terminal can receive the paging messages sent by the target network device according to a preset time period (denoted as the first time period).

[0169] In an optional embodiment, the paging message may include a paging record list; the paging record list is a list used to record the paged terminals, and the paging record list includes at least one paging record.

[0170] In an optional embodiment, for each paging record included in the paging message, the paging record may include the terminal identifier, access type, and inactive downlink data transmission indication of the paging terminal.

[0171] The terminal identifier mentioned above may include: the NAS layer ID assigned to the terminal by the NAS for core network paging, and the full inactive terminal identifier (denoted as Full I-RNTI) for RAN paging. The access type mentioned above indicates whether the paging message is initiated by a PDU session not accessed by 3GPP. The inactive downlink data transmission indication mentioned above indicates that the paging message triggers inactive downlink data transmission.

[0172] The Full I-RNTI mentioned above is the terminal identifier of the target terminal in the inactive state. Furthermore, the access type mentioned above can include multiple access types. Depending on the access type, the reason for connection restoration will differ when the paged terminal initiates the RRC connection restoration process.

[0173] For the access type in the paging record mentioned above, the corresponding value can include the following:

[0174] In scenario one, when the value corresponding to the access type is 1 (referred to as access type 1), the terminal is instructed to initiate the RRC connection recovery process and the connection recovery reason is set to Multimedia Priority Service (MPS) priority access.

[0175] In scenario two, when the value corresponding to the access type is 2 (referred to as access type 2), the terminal is instructed to initiate the RRC connection recovery process and set the connection recovery reason to the Modulation Coding Scheme (MCS) priority access.

[0176] Scenario 3: When the value corresponding to the access type is any integer from 11 to 15 (referred to as access type 11-15 respectively), the terminal is instructed to initiate the RRC connection recovery process and the connection recovery reason is set to high-priority access.

[0177] Case 4: When the value corresponding to the access type is N (denoted as access type N), such as any integer from 4 to 10, an RRC connection recovery process is initiated, and the connection recovery reason is set to inactive downlink small data transmission.

[0178] Case 5: When the value corresponding to the access type is a value other than the values ​​corresponding to the access types in Cases 1 to 4 above, such as 3, the terminal is instructed to initiate the RRC connection recovery process and the connection recovery reason is set to downlink access.

[0179] Regarding situations one through five above, when situation four is met, the paging terminal corresponding to the paging record will initiate an inactive small data transmission process, that is, execute the step of sending a connection restoration request to the target network device in step S102. The value corresponding to the access type in situation four above is pre-configured in the terminal, and can be set according to user needs, etc., and is not specifically limited here.

[0180] In an optional embodiment, for each paging record included in the paging message, in addition to the aforementioned terminal identifier, access type, and inactive downlink data transmission indication, the paging record may also include a non-contention access preamble that instructs the terminal to initiate non-contention random access.

[0181] When the paging record includes the non-contention access preamble, it indicates that the target network device has allocated a non-contention access preamble to the paged terminal corresponding to the paging record. In this case, the terminal can initiate non-contention random access based on the non-contention access preamble. When the paging record does not include the non-contention access preamble, it indicates that the target network device has not allocated a non-contention access preamble to the paged terminal corresponding to the paging record. In this case, the terminal needs to initiate contention random access. For details on terminal-initiated non-contention random access and contention random access, please refer to the description below; specific explanations will not be provided here.

[0182] In this embodiment of the disclosure, in order to reduce the possibility that the paged terminal may not receive the paging message sent by the target network device in a timely manner, the second time period may be greater than or equal to the first time period. That is, the time period for the target network device to send the paging message is greater than or equal to the time period for the target terminal to receive the paging message. Here, the first time period and the second time period are not specifically limited.

[0183] Regarding step S102 above, when the received paging message includes a specified paging record of the target terminal, a connection recovery request is sent to the target network device so that the target network device sends a downlink small data packet to the target terminal based on the received connection recovery request. The specified paging record includes an inactive downlink small data transmission indication, and the connection recovery reason in the connection recovery request is inactive downlink small data transmission.

[0184] In this step, after receiving the paging message sent by the target network device, the target terminal can determine whether the paging message includes its own designated paging record. When the paging message includes the target terminal's own designated paging record, since the designated paging record includes an inactive downlink small data transmission indication, the target terminal can initiate an RRC connection recovery process, that is, initiate an inactive downlink small data transmission process. At this time, the target terminal can send a connection recovery request to the target network device, i.e., an RRC connection recovery request. The determination of the designated paging record is described below and will not be specifically explained here.

[0185] In this embodiment of the disclosure, the connection recovery request records a connection recovery reason. Depending on the access type in the paging record, the reason sent by the terminal when initiating the RRC connection recovery process varies. For example, in step S102, since the target terminal initiates an inactive downlink small data transmission process, the connection recovery reason is: inactive downlink data transmission, i.e., inactive downlink small data transmission (MT-SDT). When the target network device receives this connection recovery request, it can determine whether to trigger the inactive downlink data transmission process based on the recorded connection recovery reason. At this time, the target network device can send downlink data to the target terminal in the form of downlink small data packets.

[0186] In an optional embodiment, when the amount of the downlink data is less than the first data amount threshold, the target network device can send the downlink data to the target terminal as a downlink small data packet.

[0187] In another optional embodiment, when the amount of the downlink data is greater than the first data amount threshold, the target network device can split the downlink data into multiple downlink small data packets with a data amount less than or equal to the first data amount threshold, and send each of the split downlink small data packets to the target terminal respectively.

[0188] In this embodiment, the data transmission between the target terminal and the target network device in the inactive state is inactive MT-SDT. Therefore, the data size of each downlink small data packet sent by the target network device to the target terminal is less than or equal to the first data size threshold. The first data size threshold can be set according to user needs, channel bandwidth, channel carrying capacity, etc. Here, the first data size threshold is not specifically limited.

[0189] Depending on the amount of downlink data, the target network device may send one or more downlink small data packets to the target terminal. No specific limit is placed on the number of downlink small data packets.

[0190] In an optional embodiment, when the received paging message does not include the specified paging record of the target terminal, the target terminal can determine that it is not the terminal being paged by the target network device. In this case, the target terminal will not take any action, that is, the target terminal will not send a connection restoration request to the target network device with the connection restoration reason being inactive downlink data transmission.

[0191] For step S103 above, that is, receiving downlink small data packets sent by the target network device.

[0192] In this step, after the target network device sends the aforementioned downlink small data packet to the target terminal, the target terminal receives the downlink small data packet. The number of downlink small data packets received by the target terminal varies depending on the amount of downlink data; therefore, the specific details of the target terminal's reception of these downlink small data packets are not provided here.

[0193] In an optional embodiment, according to the above... Figure 1 In addition to the method shown, this disclosure also provides a data transmission method. For example... Figure 2 As shown, Figure 2 This is a second flowchart illustrating a data transmission method provided in an embodiment of the present disclosure. The method includes the following steps.

[0194] Step S201: When the target terminal is inactive, receive the paging message sent by the target network device according to the first time period.

[0195] The above step S201 is the same as the above step S101.

[0196] Step S202: parse each paging record in the received paging message.

[0197] In this step, for each paging record in the received paging message, the target terminal can parse the information included in the paging record to determine information such as the terminal identifier and access type included in the paging record.

[0198] In this embodiment of the disclosure, the information parsed by the target terminal varies depending on the information included in each paging record. Here, no specific limitation is made on the information parsed from each paging record.

[0199] Step S203: For each paging record obtained by parsing, if the complete inactive terminal identifier in the paging record matches the complete inactive terminal identifier stored in the target terminal, and the paging record includes an inactive downlink small data transmission indication, then the paging record is determined to be the designated paging record of the target terminal.

[0200] In this embodiment of the disclosure, the target terminal may store the complete inactive terminal identifier corresponding to the target terminal. For each parsed paging record, the target terminal can match the complete inactive terminal identifier parsed from the paging record (i.e., the Full I-RNTI in the paging record) with its stored complete inactive terminal identifier, and determine whether the information parsed from the paging record includes the aforementioned inactive downlink small data transmission indication. Based on the matching result and the determination result, the target terminal determines whether the paging record is the designated paging record of the target terminal. The complete inactive terminal identifier stored in the target terminal is described below and will not be specifically explained here.

[0201] The matching and determination results mentioned above include at least the following:

[0202] Scenario 1: The complete inactive terminal identifier in the paging record is the same as the complete inactive terminal identifier stored in the target terminal, and the information parsed from the paging record includes an inactive downlink small data transmission indication.

[0203] Scenario 2: The complete inactive terminal identifier in the paging record is the same as the complete inactive terminal identifier stored in the target terminal, but the information parsed from the paging record does not include the inactive downlink small data transmission indication.

[0204] Scenario 3: The complete inactive terminal identifier in the paging record is different from the complete inactive terminal identifier stored in the target terminal, but the information parsed from the paging record includes an inactive downlink small data transmission indication.

[0205] Case 4: The complete inactive terminal identifier in the paging record is different from the complete inactive terminal identifier stored in the target terminal, and the information parsed from the paging record does not include an inactive downlink small data transmission indication.

[0206] In response to the above four scenarios, when scenario one is met, the target terminal can determine that the paging record is its designated paging record.

[0207] Step S204: If the complete inactive terminal identifier in the paging record does not match the complete inactive terminal identifier stored in the terminal, and / or the paging record does not include an inactive downlink small data transmission indication, then it is determined that the paging record is not the designated paging record of the target terminal.

[0208] Regarding the four situations shown in step S203 above, when any one of situation two, three or four is met, the target terminal can determine that the paging record is not its designated paging record.

[0209] When a target terminal receives a paging message and determines that each paging record in the paging message is not its own designated paging record, the target terminal can determine that the paging message does not include its own designated paging record.

[0210] In this embodiment of the disclosure, depending on the matching between the complete inactive terminal identifier in each paging record in the paging message and the complete inactive terminal identifier stored in the target terminal, and whether each paging record includes an inactive downlink small data transmission indication, the target terminal will execute either step S203 or step S204 as described above. Here, the execution of steps S203 and S204 is not specifically limited.

[0211] In an optional embodiment, when the paging record in the paging message satisfies condition two of the four conditions under step S203 above, that is, when the complete inactive terminal identifier in the paging record is the same as the complete inactive terminal identifier stored in the target terminal, but the information parsed from the paging record does not include an inactive downlink small data transmission indication, the target terminal can determine that it is the terminal paging by the target network device. In this case, the target terminal can initiate an RRC connection recovery process according to the method shown in condition one, condition two, condition three, or condition five of the five conditions shown in step S101 above, based on the value corresponding to the access type in the paging message. The recovery reason in the connection recovery request matches the value corresponding to the access type, which will not be specifically described here.

[0212] In another optional embodiment, when the paging record in the paging message satisfies condition three or four of the four conditions under step S203, since the complete inactive terminal identifier in the paging record is different from the complete inactive terminal identifier stored in the target terminal, the target terminal can determine that it is not the terminal being paged by the target network device. In this case, the target terminal can perform no processing.

[0213] Through the above steps S202-S204, the target terminal can accurately determine whether the received paging message includes its own designated paging record. Thus, when the paging message includes the designated paging record, the target terminal initiates an inactive rural small data transmission process, providing a guarantee for the initiation of the target terminal's downlink small data transmission process.

[0214] Step S205: When the received paging message includes a specified paging record of the target terminal, a connection recovery request is sent to the target network device so that the target network device sends a downlink small data packet to the target terminal based on the received connection recovery request. The specified paging record includes an inactive downlink small data transmission indication, and the connection recovery reason in the connection recovery request is inactive downlink small data transmission.

[0215] Step S206: Receive downlink small data packets sent by the target network device.

[0216] Steps S205-S206 are the same as steps S102-S103.

[0217] In an optional embodiment, the target terminal may store CG configuration information, which is a configuration authorization resource for small data transmission configuration. For details regarding the storage of CG configuration information in the target terminal, please refer to the description below; specific details will not be provided here.

[0218] In this embodiment of the disclosure, the above-mentioned CG configuration information can be used for configuring authorized resources for the uplink small data transmission process between the target terminal and the target network device, and can also be used for configuring authorized resources for the downlink small data transmission process between the target terminal and the target network device.

[0219] In an optional embodiment, when the target terminal stores CG configuration information, according to the above... Figure 1 In addition to the method shown, this disclosure also provides a data transmission method. For example... Figure 3 As shown, Figure 3 This is a schematic diagram of a third flow of the data transmission method provided in an embodiment of this disclosure. Figure 3 In the method shown, the above step S102 is refined into the following steps, namely step S1021.

[0220] Step S1021: When the received paging message includes a specified paging record of the target terminal, a connection restoration request is sent to the target network device based on the CG configuration information.

[0221] In this step, since the target terminal stores CG configuration information, it can initiate an inactive small data transmission process based on this information using a configuration authorization method. Specifically, the target terminal can configure SDT based on the CG configuration information, configuring the small data transmission on the target terminal's initial BWP, or configuring it on the target terminal's normal uplink (NUL) and supplementary uplink (SUL) carriers.

[0222] In an optional embodiment, if the target terminal moves from the current RAN cell to another RAN cell and initiates a connection recovery process in that 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 only valid in cells where the target terminal receives an RRC release message (denoted as the first release message) and enters an RRC inactive state. The reception of the first release message is described below and will not be specifically explained here.

[0223] For ease of understanding, let's take cell A as an example, where the target terminal is currently located. At some point, when the target terminal moves with the user and connects to another RAN cell, such as cell B, the Configured Grant (CG) information received and stored by the target terminal in cell A will not be able to be used to initiate a connection recovery process in cell B. The cell mentioned above is short for base station cell (also known as cellular cell).

[0224] Through the above step S1021, the target terminal can initiate an inactive small data transmission process based on its own stored CG configuration information by using CG configuration authorization.

[0225] In an optional embodiment, when the target terminal does not store the aforementioned CG configuration information, according to the above... Figure 2 In addition to the method shown, this disclosure also provides a data transmission method. For example... Figure 4 As shown, Figure 4 This is a schematic diagram of a fourth flow of the data transmission method provided in an embodiment of this disclosure. Figure 4 In the method shown, step S102 is further refined into the following steps, namely step S1022-step S1023.

[0226] Step S1022: If the received paging message includes a specified paging record of the target terminal and the specified paging record does not include a non-contention access preamble, a connection recovery request is sent to the target network device through contention access.

[0227] Step S1023: When the received paging message includes a specified paging record of the target terminal and the specified paging record includes a non-contention access preamble, a connection recovery request is sent to the target network device through non-contention access.

[0228] In this embodiment, since the target terminal does not store the aforementioned CG configuration information, it cannot initiate an inactive small data transmission process using the CG configuration authorization method. In this case, the target terminal can initiate the inactive small data transmission process using a random access method.

[0229] When the received paging message includes a specified paging record of the target terminal, the specified paging record may or may not include the aforementioned non-contention access preamble.

[0230] In an optional embodiment, when the specified paging record does not include the non-contention access preamble, the target terminal will execute the above step S1022, that is, the target terminal can initiate an inactive small data transmission process using contention access.

[0231] In another optional embodiment, when the specified paging record includes the non-contention access preamble, the target terminal will execute step S1023, that is, initiate an inactive small data transmission process using non-contention access based on the non-contention access preamble in the specified paging record. Specifically, the target terminal can send the non-contention access preamble to the target network device. The target network device, in response to the received non-contention access preamble, sends a random access response message back to the target terminal. At this time, the target terminal will receive the random access response message. The target terminal can obtain uplink synchronization based on the timing synchronization information in the random access response message and send a connection recovery request based on the uplink resources allocated by the target network device.

[0232] In steps S1022 and S1023 above, the SDT based on the Random Access Channel (RACH) can be configured on the initial BWP of the terminal, and the SDT based on RACH can also be configured on the NUL and SUL carriers of the terminal.

[0233] For the above-mentioned RACH-based SDT process, the target terminal will receive 2-step RACH and / or 4-step RACH resources for SDT transmission sent by the target network device.

[0234] In this embodiment of the disclosure, steps S1022 and S1023 are steps executed respectively based on whether the specified paging record includes a non-contention access preamble. Here, the execution of steps S1022 and S1023 is not specifically limited.

[0235] Through the above steps S1022 and S1023, when the target terminal does not store CG configuration information, such as when the target terminal moves from one RAN cell to another, it can initiate the inactive small data transmission process by adopting different contention access methods and non-contention access methods according to the presence or absence of the non-contention access preamble in the specified paging record, effectively improving the flexibility of inactive small data transmission.

[0236] In an optional embodiment, the priority of the inactive small data transmission initiated based on the CG configuration information can be higher than the priority of the inactive small data transmission initiated through random access. That is, if the target terminal stores the CG configuration information, regardless of whether the specified paging record includes the non-contention access preamble, the target terminal can preferentially use the method shown in step S1021 to send a connection restoration request to the target network device.

[0237] In an optional embodiment, according to the above... Figure 1 In addition to the method shown, this disclosure also provides a data transmission method. For example... Figure 5 As shown, Figure 5 This is a fifth flowchart illustrating a data transmission method provided in an embodiment of the present disclosure. The method includes the following steps.

[0238] Step S501: When the target terminal is inactive, receive the paging message sent by the target network device according to the first time period.

[0239] The above step S501 is the same as the above step S101.

[0240] Step S502: When the received paging message includes a specified paging record of the target terminal, determine whether the target terminal meets the preset connection initiation conditions at the current time. The preset connection initiation conditions are: the data volume of the wireless bearer configured for inactive small data transmission is less than the preset data volume threshold and / or an inactive downlink small data transmission indication is received, the downlink RSRP is greater than the preset threshold, and the uplink small data transmission resources are valid.

[0241] In this step, when the paging message received by the target terminal includes its own designated paging record, the target terminal can determine whether it meets the preset connection initiation conditions, and if it meets the preset initiation conditions, it executes step S503.

[0242] The aforementioned preset connection initiation conditions may be: the data volume of the wireless bearer configured for inactive small data transmission is less than a preset data volume threshold, the downlink RSRP is greater than a preset threshold, and the uplink small data transmission resources are valid; or, receiving an inactive downlink small data transmission indication, the downlink RSRP is greater than a preset threshold, and the uplink small data transmission resources are valid; or, the data volume of the wireless bearer configured for inactive small data transmission is less than a preset data volume threshold, receiving an inactive downlink small data transmission indication, the downlink RSRP is greater than a preset threshold, and the uplink small data transmission resources are valid. Here, no specific limitations are imposed on the aforementioned preset connection initiation conditions.

[0243] The aforementioned preset data volume threshold and preset threshold can be set according to user needs, the carrying capacity of the wireless network, etc., and are not specifically limited here.

[0244] In an optional embodiment, the aforementioned preset connection initiation condition can also be expressed as follows: a higher layer above the RRC layer requests the restoration of the RRC connection, System Information Block Type 1 (SIB1) contains a common configuration for small data transmission, a small data transmission configuration is configured, all uplink small data is mapped to the radio bearer of the small data transmission configuration and / or a non-active downlink small data transmission indication is received, and a lower layer below the RRC layer indicates that the triggering condition for non-active small data is met. That is: a higher layer requests the restoration of the RRC connection, SIB1 contains a common configuration for small data transmission, a small data transmission configuration is configured, and all uplink small data is mapped to the radio bearer of the small data transmission configuration; or a higher layer requests the restoration of the RRC connection, SIB1 contains a common configuration for small data transmission, a small data transmission configuration is configured, a non-active downlink small data transmission indication is received, and a lower layer indication meets the triggering condition for non-active small data; or, a higher layer requests the restoration of the RRC connection, SIB1 contains a common configuration for small data transmission, a small data transmission configuration is configured, all uplink small data is mapped to the radio bearer of the small data transmission configuration and / or a non-active downlink small data transmission indication is received, and a lower layer indication meets the triggering condition for non-active small data.

[0245] The lower layers below the RRC layer can be the Medium Access Control (MAC) layer, the Physical (PHY) layer, etc., all below the RRC layer. The higher layers above the RRC layer can be any layer above the RRC layer; here, no specific limitations are made on the aforementioned higher and lower layers.

[0246] Step S503: When the target terminal meets the preset connection initiation conditions, a connection recovery request is sent to the target network device, so that the target network device sends a downlink small data packet to the target terminal based on the received connection recovery request, specifying that the paging record includes an inactive downlink small data transmission indication, and the connection recovery reason in the connection recovery request is inactive downlink small data transmission.

[0247] In this step, when the target terminal meets the above-mentioned preset connection initiation conditions, the target device can send a connection recovery request to the target network device. For details, please refer to the sending of the connection recovery request in step S102 above, which will not be described in detail here.

[0248] In an optional embodiment, when the target terminal does not meet the aforementioned preset connection initiation conditions, the target terminal may choose not to take any action. That is, it may not send the aforementioned connection restoration request.

[0249] By judging the above-mentioned preset connection initiation conditions, it can be ensured that the target terminal has met the conditions for initiating inactive small data transmission, thus guaranteeing the success of the inactive small data transmission process between the target terminal and the target network device.

[0250] Step S504: Receive downlink small data packets sent by the target network device.

[0251] Step S504 is the same as step S103.

[0252] In an optional embodiment, according to the above... Figure 5 The present disclosure also provides a data transmission method, as shown in the embodiments. Figure 6 As shown, Figure 6 This is a sixth flowchart illustrating a data transmission method provided in an embodiment of the present disclosure. The method includes the following steps.

[0253] Step S601: When the target terminal is inactive, receive the paging message sent by the target network device according to the first time period.

[0254] Step S602: When the received paging message includes a specified paging record of the target terminal, determine whether the target terminal meets the preset connection initiation conditions at the current time. The preset connection initiation conditions are: the data volume of the wireless bearer configured for inactive small data transmission is less than the preset data volume threshold and / or an inactive downlink small data transmission indication is received, the downlink RSRP is greater than the preset threshold, and the uplink small data transmission resources are valid.

[0255] Step S603: When the target terminal meets the preset connection initiation conditions, a connection recovery request is sent to the target network device, so that the target network device sends a downlink small data packet to the target terminal based on the received connection recovery request, specifying that the paging record includes an inactive downlink small data transmission indication, and the connection recovery reason in the connection recovery request is inactive downlink small data transmission.

[0256] The steps S601-S603 described above are the same as the steps S501-S503 described above.

[0257] Step S604: When the target terminal meets the preset connection initiation conditions, start a timer for detecting the recovery process of inactive small data transmission.

[0258] Both steps S603 and S604 are executed when the target terminal meets the preset connection initiation conditions. Here, there is no specific limitation on the execution order of steps S603 and S604.

[0259] Step S605: Receive downlink small data packets sent by the target network device.

[0260] Step S605 is the same as step S504.

[0261] Step S606: When the target terminal does not meet the preset connection initiation conditions, start a timer for monitoring the inactive state recovery process and send a timeout indication to the MAC entity. The timeout indication is used to indicate that the CG timing advance timer in the CG configuration information of the small data transmission has timed out.

[0262] Through the above steps S604 and S606, the target terminal can start a timer to detect the inactive state transmission recovery process when the preset connection initiation conditions are met, thereby ensuring that the inactive state transmission recovery process will not time out. Furthermore, when the preset connection initiation conditions are not met, the timer to monitor the inactive state recovery process is started to provide a guarantee for the inactive state recovery process.

[0263] In an optional embodiment, the connection restoration request is either a first connection restoration request or a second connection restoration request.

[0264] The aforementioned first connection recovery request and second connection recovery request include: recovery identifier, recovery integrity check code, and recovery reason.

[0265] The recovery identifier of the first connection recovery request is the complete inactive terminal identifier stored in the target terminal, and the recovery identifier of the second connection request is the truncated inactive terminal identifier stored in the target terminal; the recovery integrity check code is the authentication token used for terminal authentication at the base station; and the recovery reason is inactive downlink small data transmission.

[0266] In an optional embodiment, according to the above... Figure 1 The method shown in this disclosure also provides a method for sending a connection restoration request. For example... Figure 7 As shown, Figure 7 This is a flowchart illustrating a connection restoration request sending method provided in an embodiment of the present disclosure. The method includes the following steps.

[0267] Step S701: When the SIB1 sent by the base station indicates that the connection recovery request uses the full recovery identifier, the first connection recovery request is selected as the connection recovery request; or, when the received SIB1 does not indicate that the full recovery identifier is used, the second connection recovery request is selected as the connection recovery request.

[0268] In this step, the base station in the core network can send SIB1 to the target terminal. The target terminal will receive this SIB1. This SIB1 includes information indicating the recovery identifier used in the connection restoration request.

[0269] In an optional embodiment, when the received SIB1 indicates that the recovery identifier in the connection recovery request uses a full recovery identifier, the target terminal can determine that the recovery identifier in the connection recovery request is its own stored full inactive terminal identifier. In this case, the target terminal can select the aforementioned first connection recovery request as the connection recovery request.

[0270] In another optional embodiment, when the received SIB1 does not indicate that the recovery identifier in the connection recovery request uses the full recovery identifier, the target terminal can determine that the recovery identifier in the connection recovery request is its own stored truncated inactive terminal identifier (denoted as ShortI-RNTI). In this case, the target terminal can select the aforementioned second connection recovery request as the connection recovery request.

[0271] Step S702: Recover preset security information from the stored access layer context information. The preset security information includes: RRC configuration, ROHC status, the mapping relationship between the stored QoS flow and DRB, the base station root key, and the integrity protection key.

[0272] In this embodiment of the disclosure, the aforementioned access layer context information can be stored in an anchor point. The anchor point is the NG connection between the last serving base station (gNB) and the UE-related Access and Mobility Management Function (AMF) and User Plane Function (UPF). NG is the logical interface between the radio access network and the core network.

[0273] Step S703: Reconstruct the PDCP entity for SIB1.

[0274] Step S704, restore SIB1.

[0275] Step S705: For each radio bearer configured for inactive small data transmission, recover the configuration associated with the RLC bearer configured with the primary cell group and PDCP from the access layer context information, and reconstruct the PDCP entity for that radio bearer.

[0276] Step S706: Restore all radio bearers to the inactive small data transmission configuration.

[0277] Step S707: Send the connection restoration request to the target network device.

[0278] Steps S701-S707 above are a refinement of the step of sending a connection recovery request to the target network device in step S102 above.

[0279] In an optional embodiment, according to the above... Figure 1In addition to the method shown, this disclosure also provides a data transmission method. For example... Figure 8 As shown, Figure 8 This is a seventh flowchart illustrating a data transmission method provided in an embodiment of the present disclosure. The method includes the following steps.

[0280] Step S801: When the current state of the target terminal is connected, a first release message is received from the target network device. The first release message includes pause configuration information that instructs the terminal to perform inactive state configuration.

[0281] In this embodiment of the disclosure, the target terminal can be in an inactive state, a connected state, or an idle state. When the target terminal is in a connected state, the target network device can send an RRC release message (denoted as the first release message) to the target terminal. At this time, the target terminal will receive the first release message.

[0282] In an optional embodiment, the first release message may include pause configuration information. This pause configuration information is used to instruct the terminal to perform inactive state configuration.

[0283] The above-mentioned pause configuration information may include: full inactive terminal identifier (i.e., the Full I-RNTI), truncated inactive terminal identifier (i.e., the Short I-RNTI), radio paging cycle, radio (RAN) notification area information, timer, next-hop chain count value, and inactive small data transmission configuration information.

[0284] In an optional embodiment, the aforementioned complete inactive terminal identifier and truncated inactive terminal identifier are temporary wireless network identifier values ​​for the inactive terminal. These are used by the target network to locate the anchor node before the terminal enters the inactive state and its stored access layer context information. The complete inactive terminal identifier and the truncated inactive terminal identifier have different sizes. For example, the complete inactive terminal identifier can be 40 bits, and the truncated inactive terminal identifier can be 24 bits. Here, the specific size of the complete inactive terminal identifier and the truncated inactive terminal identifier is not limited.

[0285] The aforementioned paging cycle is the RAN paging cycle configured by the RAN-side node (such as a base station) for inactive terminals. This paging cycle can be 32 radio frames, 64 radio frames, 128 radio frames, 256 radio frames, etc. No specific limitation is made here.

[0286] Radio (RAN) notification area information may include a list of cells configured as RAN areas, as well as the RAN area code or Random Access (RA) code (i.e., the radio area configuration list).

[0287] The aforementioned timer is used to trigger the periodic RNAU process in the terminal.

[0288] The next-hop chain count value mentioned above is used to calculate the security key after the connection is restored.

[0289] The aforementioned inactive small data transmission configuration information includes: an inactive small data transmission DRB list and a small data transmission SRB2 indication. The inactive small data transmission DRB list indicates the DRB identifier of the small data transmission configuration, and the small data transmission SRB2 indication is used to indicate whether the terminal's small data transmission configuration includes SRB2. Here, SRB stands for Signalalling Radio Bearers, also known as signaling radio bearers.

[0290] In the above list of inactive small data transmission DRBs, if the sequence size is 0, the target terminal can determine that the network has not configured a DRB for small data transmission.

[0291] In an optional embodiment, the above-mentioned inactive small data transmission configuration information may further include CG configuration information; wherein, the CG configuration authorization information includes: CG SSB RSRP threshold, CG timing advance timer, CG timing advance verification configuration, and CG RSRP change threshold.

[0292] Wherein, the aforementioned CG SSB RSRP threshold is the RSRP threshold for single-sideband (SSB) selection based on CG resources for small data transmission; the aforementioned CG timing advance timer is used for timing synchronization of small data transmission; the aforementioned CG timing advance verification configuration is used for configuration of TA verification based on RSRP; and the aforementioned CG RSRP change threshold is the RSRP threshold used for TA verification of small data transmission.

[0293] In an optional embodiment, when the above-mentioned CG timed early verification configuration is not configured in the above CG configuration information, the target terminal will not execute the RSRP-based TA verification process.

[0294] In this embodiment of the disclosure, regarding the aforementioned pause configuration information, when the network redirects the terminal to the Radio Access Technology (RAT) inter-carrier frequency, or configures the terminal with a Dual Active Protocol Stack (DAPS) bearer, the network does not configure pause configuration information for the terminal; that is, the aforementioned pause configuration information is not included in the first release message.

[0295] In an optional embodiment, after receiving the aforementioned pause configuration information, the target terminal can store the pause configuration information. For example, the target terminal can store the aforementioned Full I-RNTI and Short I-RNTI. Then, based on the stored Full I-RNTI and Short I-RNTI, it can perform the query for the specified paging record, and send the first connection recovery request / second connection recovery request, etc.

[0296] Step S802: Based on the pause configuration information, switch the current state to the inactive state.

[0297] In this embodiment of the disclosure, after receiving the first release message, the target terminal will perform the following steps based on the first release message to switch the current state of the target terminal from the connected state to the inactive state.

[0298] Step 1: Reset the MAC address and release the default MAC cell group configuration.

[0299] Step 2: Apply pause configuration information.

[0300] Step 3: When the paused configuration information includes CG configuration information, determine each DRB in the inactive small data transmission DRB list and the small data transmission SRB2 indicator as the DRB and SRB2 of the inactive small data transmission process; rebuild the RLC entity for each RLC bearer in the target terminal configuration; trigger the PDCP entity to execute the SDU discarding process for the restored SRB2 and SRB1; configure the small data transmission CG resource for the MAC entity and instruct it to start the CG timer advance timer.

[0301] Step 4: Store the current access layer root key KgNB and the integrity protection key KRRCint of RRC signaling, ROHC state, the mapping rules between the stored QoS flow and DRB, the C-RNTI used in the source PCell, the cell identifier and the physical cell identifier of the source PCell, the SpCell common configuration in the synchronization reconfiguration message of the NR PSCell, and all other configuration parameters except those 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 SCG of the E-UTRAPSCell, the PSCell configuration in the EN-DC, and the serving cell common configuration SIB in the inactive terminal access layer context information.

[0302] The SpCell mentioned above is the set of Pcell and PSCell, which can be expressed as: SpCell = Pcell + PSCell. EN-DC stands for: E-UTRA NR dual connectivity with MCG using E-UTRA and SCG using NR, also known as E-UTRA NR dual connectivity (MCG Master Cell Group (MCG) uses Universal Terrestrial Radio Access (E-UTRA), SCG uses New Radio (NR)).

[0303] In step four above, the SpCell common configuration in the NR PSCell synchronization reconfiguration message, as well as the parameters in the PCell synchronization reconfiguration message, the NR PSCell synchronization reconfiguration message, and the SCG mobility control information of the E-UTRA PSCell are all processed according to the configuration in the CG configuration above, and will not be specifically explained here.

[0304] Step 5: Pause all SRBs and DRBs except SRB0.

[0305] Step 6: Instruct all lower layers of the DRB to pause PDCP, which are located below the RRC layer.

[0306] Step 7: Switch to the inactive state and perform cell reselection.

[0307] In step seven above, the target terminal can perform cell reselection according to relevant standards, such as the steps in TS38.304. The specific process of cell reselection will not be described here.

[0308] Through the above steps S801-S802, the target terminal can switch its current state from connected state to inactive state according to the received first release message. This not only allows the target terminal to quickly enter the connected state from the active state, but also facilitates the inactive small data transmission process when a specified paging record is received from the target terminal later, reducing the signaling overhead and latency of the data transmission process.

[0309] Step S803: Receive system messages broadcast by the target network device. The system messages include downlink transmission frequency information, initial downlink BWP, BCCH configuration information, and PCCH configuration information.

[0310] In this step, the target network device can broadcast system messages within its corresponding network coverage area. At this time, every terminal within that network coverage area can receive the system messages. That is, the target terminal can receive the system messages.

[0311] The aforementioned system messages may include downlink common configuration information for downlink small data transmission and reception. This downlink common configuration information may include downlink transmission frequency information, initial downlink BWP, BCCH configuration, and PCCH configuration information.

[0312] Among them, the initial downlink BWP mentioned above is the initial downlink BWP configuration of the primary cell (i.e., the PCell mentioned above); the BCCH configuration information mentioned above is the configuration related to modifying the system message transmission period; the PCCH configuration information mentioned above includes the default paging period, the number and configuration of paging frames, the number of paging opportunities, and the first PDCCH listening opportunity.

[0313] The default paging period is the default paging period broadcast in the system message. The number and configuration of paging frames are used to derive the total number of paging frames and the paging frame offset. The number of paging opportunities is used to indicate the number of paging opportunities in each paging frame. The paging opportunity is a set of PDCCH listening opportunities, which consists of multiple time slots for sending paging control information. The first PDCCH listening opportunity is the first PDCCH listening opportunity used to listen for paging opportunities in the paging frame.

[0314] In this embodiment of the disclosure, the execution order of steps S801-S803 is not specifically limited.

[0315] Step S804: The smaller value between the wireless paging period and the default paging period is determined as the first time period for the target terminal to receive paging messages when it is in an inactive state.

[0316] In this step, based on the default paging period in the downlink common configuration information included in the aforementioned system message, and the radio paging period in the pause configuration information included in the aforementioned first release message, the target terminal can obtain the smaller of the default paging period and the radio paging period, and determine this paging period as the time period for the target terminal to receive paging messages (i.e., the aforementioned first time period). That is, when the default paging period is less than the radio paging period, the default paging period is determined as the aforementioned first time period; when the default paging period is greater than the radio paging period, the radio paging period is determined as the aforementioned first time period.

[0317] Through the above steps S803-S804, the target terminal can determine its own paging message receiving time period based on the paging period included in the system message and the first release message. This can effectively ensure that the target terminal can receive as many paging messages as possible from the target network device.

[0318] Step S805: When the target terminal is inactive, receive the paging message sent by the target network device according to the first time period.

[0319] In an optional embodiment, the first time period is the smaller value between the wireless paging period in the pause configuration information and the default paging period in the downlink common configuration information.

[0320] Step S806: When the received paging message includes a specified paging record of the target terminal, a connection recovery request is sent to the target network device so that the target network device sends a downlink small data packet to the target terminal based on the received connection recovery request. The specified paging record includes an inactive downlink small data transmission indication, and the connection recovery reason in the connection recovery request is inactive downlink small data transmission.

[0321] Step S807: Receive downlink small data packets sent by the target network device.

[0322] Steps S805-S807 are the same as steps S101-S103.

[0323] In an optional embodiment, the connection restoration request may further include uplink small data packets. When the connection restoration request includes uplink small data packets, according to the above... Figure 1 In addition to the method shown, this disclosure also provides a data transmission method. For example... Figure 9 As shown, Figure 9 This is an eighth flowchart illustrating a data transmission method provided in an embodiment of the present disclosure. The method includes the following steps.

[0324] Step S901: When the target terminal is inactive, receive the paging message sent by the target network device according to the first time period.

[0325] The above step S901 is the same as the above step S101.

[0326] In step S902, when the received paging message includes a specified paging record of the target terminal, a connection recovery request is sent to the target network device so that the target network device sends a downlink small data packet to the target terminal based on the received connection recovery request. The specified paging record includes an inactive downlink small data transmission indication, and the connection recovery reason in the connection recovery request is inactive downlink small data transmission.

[0327] In step S902 above, when the target terminal sends a connection restoration request to the target network device, the connection restoration request may also include an uplink small data packet. This uplink small data packet is a data packet corresponding to the uplink data or a sub-data packet obtained by splitting up the uplink data. The description of the uplink small data packet is similar to that of the downlink small data packet described above, and will not be elaborated upon here.

[0328] The data volume of the aforementioned uplink small data packet can be less than or equal to the second data volume threshold.

[0329] In this embodiment of the disclosure, when the target network device receives the connection restoration request including the uplink small data packet, in addition to sending the downlink small data packet to the target terminal, it can also generate corresponding feedback information for the uplink small data packet in the connection restoration request and send the feedback information to the target terminal. That is, the downlink small data packet and the feedback information are sent to the target terminal together. Here, the generation of the feedback information is not specifically described.

[0330] Step S903: Receive downlink small data packets sent by the target network device, and feedback information sent by the target network device in response to the uplink small data packets.

[0331] In this step, since the target network device sends not only the aforementioned downlink small data packets to the target terminal, but also feedback information regarding the aforementioned uplink small data packets to the target terminal, the target terminal will receive the aforementioned downlink small data packets and feedback information.

[0332] In an optional embodiment, when the aforementioned uplink small data packet is a sub-data packet corresponding to uplink data, it means that the target terminal still has some uplink small data packets that have not been sent to the target network device. After 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 the uplink data sent by the target terminal to the target network device.

[0333] In the above embodiments, since there may be multiple remaining unsent uplink small data packets, the target terminal transmits only one uplink small data packet per transmission process during the inactive uplink small data transmission. The data size of each uplink small data packet is less than or equal to the aforementioned second data size threshold.

[0334] The second data volume threshold can be greater than, less than, or equal to the first data volume threshold, and can be set in accordance with the setting method of the first data volume threshold. Here, no specific limitation is made on the second data volume threshold.

[0335] During the aforementioned uplink small data transmission process, the transmission of uplink small data packets can utilize the small data transmission resources configured by the CG configuration information allocated by the target network device or the uplink time-frequency resources temporarily scheduled by the target network device.

[0336] By including the aforementioned uplink small data packet in the connection recovery request, the inactive uplink data transmission process can be realized, avoiding the signaling overhead and latency caused by switching from inactive to connected state. This improves the transmission efficiency of the uplink small data packet and saves the signaling overhead of the uplink small data packet, which effectively reduces the signaling overhead and latency of the data transmission process.

[0337] In an optional embodiment, according to the above... Figure 1 In addition to the method shown, this disclosure also provides a data transmission method. For example... Figure 10 As shown, Figure 10 This is a ninth flowchart illustrating a data transmission method provided in an embodiment of the present disclosure. The method includes the following steps.

[0338] Step S1001: When the target terminal is inactive, receive the paging message sent by the target network device according to the first time period.

[0339] In step S1002, when the received paging message includes a specified paging record of the target terminal, a connection recovery request is sent to the target network device so that the target network device sends a downlink small data packet to the target terminal based on the received connection recovery request. The specified paging record includes an inactive downlink small data transmission indication, and the connection recovery reason in the connection recovery request is inactive downlink small data transmission.

[0340] Step S1003: Receive downlink small data packets sent by the target network device.

[0341] Steps S1001-S1003 are the same as steps S101-S103.

[0342] Step S1004: Receive a second release message sent by the target network device when the downlink small data packet transmission is completed. The second release message includes indication information indicating a state switch.

[0343] In this step, after the target network device completes the transmission of the aforementioned downlink small data packets—that is, after the target network device has sent all the downlink small data packets corresponding to the aforementioned downlink data to the target terminal—it can send an RRC release message (denoted as the second release message) to the target terminal. At this time, the target terminal will receive this second release message.

[0344] In this embodiment of the disclosure, the indication information in the second release message can be used to indicate switching the current state of the terminal to an inactive state, such as the aforementioned pause configuration information, or it can be used to indicate switching the current state of the terminal to an idle state. The indication information in the second release message varies depending on the state that the target terminal needs to switch to. Here, no specific limitation is made on the indication information in the second release message.

[0345] Step S1005: Based on the indication information, switch the current state to an inactive state or an idle state.

[0346] In this step, after receiving the second release message, the target terminal can switch states based on the indication information in the second release message. For example, it can switch its current state to an inactive state or an idle state. The state switching process of the target terminal will not be described in detail here.

[0347] In this embodiment of the disclosure, when the target terminal switches to an inactive or idle state according to the indication information in the second release message, the target terminal and the target network device will no longer be able to perform the inactive small data transmission, that is, they will no longer perform the transmission of the uplink small data packets and the transmission of the downlink small data packets.

[0348] By sending the second release message, the RRC connection between the target terminal and the target network device can be promptly disconnected when the inactive small data transmission is completed, thereby releasing system resources.

[0349] In an optional embodiment, when there are multiple downlink small data packets, in order to further reduce the signaling overhead and latency consumption during data transmission, the target network device may send the last downlink small data packet transmitted in the downlink small data packet along with the second release message to the target terminal.

[0350] In the above embodiments, the second release message is sent after the transmission of the last downlink small data packet corresponding to the downlink data is completed. Alternatively, when the amount of uplink data is greater than the amount of downlink data, that is, when all downlink small data packets have been transmitted but the uplink small data packets have not yet been fully transmitted, the target network device can send the second release message to the target terminal after receiving the last uplink small data packet. Here, the specific timing of sending the second release message is not limited.

[0351] Based on the same inventive concept, and according to the data transmission method provided in the above-described embodiments of this disclosure, this disclosure also provides a data transmission method. For example... Figure 11 As shown, Figure 11This is a tenth flowchart illustrating a data transmission method provided in an embodiment of the present disclosure. The method is applied to a target network device and specifically includes the following steps.

[0352] Step S1101: According to the second time period, send a paging message to the target terminal whose current state is inactive.

[0353] In this step, the target network device can send paging messages to terminals within its network coverage area that are either connected or inactive, according to a second time period. At this time, the terminals within the target network device's network coverage area will receive the paging message. This is the paging message that the target terminal will receive.

[0354] In this embodiment of the disclosure, the paging message may be sent in the form of multicast / broadcast, etc. Here, the method of sending the paging message is not specifically limited.

[0355] In an optional embodiment, the paging message may include a paging record list; the paging record list is a list used to record the paged terminals, and the paging record list includes at least one paging record.

[0356] In one optional embodiment, the paging record includes the terminal identifier, access type, and inactive downlink data transmission indication of the paged terminal.

[0357] The terminal identifier includes: the NAS layer ID assigned to the terminal by the NAS for core network paging, and the complete inactive terminal identifier for RAN paging; the access type is used to indicate whether the paging message is initiated by a PDU session that is not accessed by 3GPP; and the inactive downlink data transmission indicator is used to indicate that the paging message is used to trigger inactive downlink data transmission.

[0358] In an optional embodiment, the paging record may further include a non-contention access preamble instructing the terminal to initiate non-contention random access.

[0359] Step S1102: Receive a connection recovery request sent by the target terminal. The connection recovery request is sent by the target terminal when it receives a paging message that includes its own designated paging record. The designated paging record includes an inactive downlink data transmission indication, and the connection recovery reason in the connection recovery request is inactive downlink data transmission.

[0360] In this step, after the target network device sends the aforementioned paging message to the target terminal, if the target terminal includes its own designated paging record in the paging message, it sends a connection restoration request to the target network device with the connection restoration reason being inactive downlink data transmission. The target network device will receive this connection restoration request.

[0361] The specified paging record mentioned above includes an inactive downlink small data transmission indication. For a description of the specified paging record, please refer to the description above; further details will not be provided here.

[0362] Step S1103: Based on the connection restoration request, send downlink small data packets to the target terminal so that the target terminal can receive the downlink small data packets.

[0363] In this step, after receiving a connection restoration request from the target terminal, the target network device, based on the connection restoration reason in the request being inactive downlink data transmission, can acquire downlink small data packets and send them to the target terminal. A description of the downlink small data packets can be found above and will not be elaborated upon here.

[0364] In an optional embodiment, the connection restoration request can be either a first connection restoration request or a second connection restoration request. The first connection restoration request is sent by the target terminal when the SIB1 sent by the base station indicates that the connection restoration request uses a full restoration identifier, while the second connection restoration request is sent by the target terminal when the SIB1 sent by the base station does not indicate that the connection restoration request uses a full restoration identifier.

[0365] The aforementioned first connection recovery request and second connection recovery request include: recovery identifier, recovery integrity check code, and recovery reason.

[0366] The recovery identifier of the first connection recovery request is the complete inactive terminal identifier stored in the target terminal, and the recovery identifier of the second connection request is the truncated inactive terminal identifier stored in the target terminal; the recovery integrity check code is the authentication token used for terminal authentication at the base station; and the recovery reason is inactive downlink small data transmission.

[0367] In the aforementioned first connection recovery request and second connection recovery request, the recovery identifier is used as the UE identifier for facilitating UE context information retrieval in the gNB, such as the resumeIdentify in RRCResumeRequest1 of the relevant standard TS38.331. The aforementioned recovery integrity checksum is a bit string used as an authentication token for UE authentication in the gNB, such as resumeMAC-I in the relevant standard TS38.331; the aforementioned recovery reason is used to add a recovery reason provided by the upper layer or RRC to the first connection recovery request. When the UE uses an unknown reason value (such as MT-SDT in this embodiment of the disclosure), the gNB will not reject the first connection recovery request according to the resumeCause in the relevant standard such as TS38.331.

[0368] pass Figure 11The method shown allows the target terminal to send a connection restoration request to the target network device when it is in an inactive state. This triggers 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 restoration request. The target terminal will also receive the downlink small data packet, thus realizing the downlink small data transmission process of the inactive terminal.

[0369] Furthermore, compared to related technologies where inactive terminals must switch to connected mode to transmit data, this embodiment introduces a new terminal access type, namely inactive downlink small data transmission, by specifying an inactive downlink data transmission indication in the paging record. This allows the terminal to receive downlink small data packets sent by the target network device in an inactive state, avoiding the signaling overhead and latency caused by switching from inactive to connected mode. This improves the transmission efficiency of downlink small data packets and saves signaling overhead, effectively reducing signaling overhead and latency during data transmission.

[0370] In an optional embodiment, according to the above... Figure 11 In addition to the method shown, this disclosure also provides a data transmission method. For example... Figure 12 As shown, Figure 12 This is an eleventh flowchart illustrating a data transmission method provided in an embodiment of this disclosure. The method includes the following steps.

[0371] Step S1201: Send a first release message to the terminal. The first release message includes pause configuration information that instructs the terminal to perform inactive state configuration, so that the target terminal can switch the current state to inactive state based on the pause configuration information.

[0372] In this step, the target network device can send an RRC release message (i.e., the first release message mentioned above) to the target terminal in the connected state. This first release message includes pause configuration information instructing the terminal to perform inactive state configuration. After receiving the first release message, the target terminal can switch its state according to the pause configuration information in the first release message, that is, switch its current state from the connected state to the inactive state.

[0373] The above-mentioned pause configuration information includes: complete inactive terminal identifier, truncated inactive terminal identifier, wireless paging cycle, wireless notification area information, timer, next-hop chain count value, and inactive small data transmission configuration information.

[0374] The above-mentioned complete inactive terminal identifier and truncated inactive terminal identifier are temporary wireless network identifier values ​​of inactive terminals. They are used by the target network side to find the anchor node before the terminal enters the inactive state and the access layer context information it stores. The complete inactive terminal identifier and the truncated inactive terminal identifier have different sizes.

[0375] The wireless paging cycle is the RAN paging cycle configured by the RAN-side node for inactive terminals;

[0376] The wireless notification area information includes a cell list and a wireless area configuration list. The cell list is a list of cells configured in the RAN area, and the wireless area configuration list includes the RAN area code or RA code of the RAN area.

[0377] The timer is used to trigger the periodic RNAU process in the terminal;

[0378] The next-hop chain count is used to calculate the security key after the connection is restored;

[0379] The inactive small data transmission configuration information includes: an inactive small data transmission DRB list and a small data transmission SRB2 indicator. The inactive small data transmission DRB list indicates the DRB identifier of the small data transmission configuration, and the small data transmission SRB2 indicator is used to indicate whether the terminal has an SRB2 for the small data transmission configuration.

[0380] In an optional embodiment, the above-mentioned inactive small data transmission configuration information further includes CG configuration information; wherein, the CG configuration authorization information includes: CG SSB RSRP threshold, CG timing advance timer, CG timing advance verification configuration, and CGRSRP change threshold.

[0381] Among them, the CG SSB RSRP threshold is the RSRP threshold for SSB selection based on CG resources for small data transmission; the CG timing advance timer is used for timing synchronization of small data transmission; the CG timing advance verification configuration is used for configuration of TA verification based on RSRP; and the CG RSRP change threshold is the RSRP threshold used for TA verification of small data transmission.

[0382] Through the above step S1201, the target terminal can switch its current state from connected state to inactive state according to the first release message issued by the target network device. This not only allows the target terminal to quickly enter the connected state, but also facilitates the inactive small data transmission process when a specified paging record is received later, reducing the signaling overhead and latency consumption of the data transmission process.

[0383] Step S1202: Broadcast system messages. The system messages include downlink transmission frequency information, initial downlink BWP, BCCH configuration information, and PCCH configuration information.

[0384] In this step, the target network device can broadcast system messages within its network coverage area. At this time, all terminals within the target network device's network coverage area will receive this system message. That is, the system message that the target terminal will receive.

[0385] In an optional embodiment, 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 the configuration related to modifying the system message passing period; the PCCH configuration information includes the default paging period, the number and configuration of paging frames, the number of paging opportunities, and the first PDCCH listening opportunity.

[0386] The default paging period is the default paging period broadcast in the system message. The number and configuration of paging frames are used to derive the total number of paging frames and the paging frame offset. The number of paging opportunities is used to indicate the number of paging opportunities in each paging frame. The paging opportunity is a set of PDCCH listening opportunities, which consists of multiple time slots for sending paging control information. The first PDCCH listening opportunity is the first PDCCH listening opportunity used to listen for paging opportunities in the paging frame.

[0387] In this embodiment of the disclosure, the execution order of the above steps S1201 and S1202 is not specifically limited.

[0388] Step S1203: The default paging period is determined as the second time period for sending paging messages.

[0389] In this embodiment of the disclosure, the second time period for the target network device to send a paging message can be the wireless paging period included in the first release message.

[0390] Step S1204: According to the second time period, send a paging message to the target terminal whose current state is inactive.

[0391] Step S1205: Receive a connection recovery request sent by the target terminal. The connection recovery request is sent by the target terminal when it receives a paging message that includes its own designated paging record. The designated paging record includes an inactive downlink data transmission indication, and the connection recovery reason in the connection recovery request is inactive downlink data transmission.

[0392] Step S1206: Based on the connection restoration request, send downlink small data packets to the target terminal so that the target terminal can receive the downlink small data packets.

[0393] The steps S1204-S1206 described above are the same as the steps S1101-S1103 described above.

[0394] In an optional embodiment, the connection restoration request may further include uplink small data packets. When the connection restoration request includes uplink small data packets, according to the above... Figure 11 In addition to the method shown, this disclosure also provides a data transmission method. For example... Figure 13 As shown, Figure 13 This is a schematic diagram of a twelfth type of data transmission method provided in an embodiment of the present disclosure. The method includes the following steps.

[0395] Step S1301: According to the second time period, send a paging message to the target terminal whose current state is inactive.

[0396] The above step S1301 is the same as the above step S1101.

[0397] Step S1302: Receive a connection recovery request sent by the target terminal. The connection recovery request is sent by the target terminal when it receives a paging message that includes its own designated paging record. The designated paging record includes an inactive downlink data transmission indication. The connection recovery reason in the connection recovery request is inactive downlink data transmission.

[0398] In step S1302 above, the connection restoration request sent by the target terminal to the target network device may also include uplink small data packets. These uplink small data packets are either the data packets corresponding to the uplink data sent by the target terminal to the target network device, or multiple sub-data packets obtained by splitting uplink data.

[0399] Step S1303: Upon receiving a connection recovery request, generate feedback information for the uplink small data packets and obtain the downlink small data packets.

[0400] Step S1304: Send downlink small data packets and feedback information to the target terminal.

[0401] In this embodiment of the disclosure, by adding uplink small data packets to the connection recovery request, downlink small data packet transmission can be completed simultaneously with uplink small data packet transmission, thereby improving data transmission efficiency.

[0402] In an optional embodiment, according to the above... Figure 11 In addition to the method shown, this disclosure also provides a data transmission method. For example... Figure 14 As shown, Figure 14 This is a thirteenth flowchart illustrating a data transmission method provided in this embodiment of the disclosure. The method includes the following steps.

[0403] Step S1401: According to the second time period, send a paging message to the target terminal whose current state is inactive.

[0404] Step S1402: Receive a connection recovery request sent by the target terminal. The connection recovery request is sent by the target terminal when it receives a paging message that includes its own designated paging record. The designated paging record includes an inactive downlink data transmission indication, and the connection recovery reason in the connection recovery request is inactive downlink data transmission.

[0405] Step S1403: Based on the connection restoration request, a downlink small data packet is sent to the target terminal so that the target terminal can receive the downlink small data packet.

[0406] The steps S1401-S1403 described above are the same as the steps S1101-S1103 described above.

[0407] 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 includes indication information indicating a state switch, so that the target terminal switches the current state to an inactive state or a spatial state based on the indication information.

[0408] In this step, after sending downlink small data packets to the target terminal, the target network device can send a second release message to the target terminal, which includes indication information. This indication information is used to instruct the terminal to switch states. 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 indication information in the second release message.

[0409] By sending the second release message mentioned above, the target terminal's state can be switched to inactive or idle state in a timely manner after the downlink data transmission in inactive state is completed.

[0410] In an optional embodiment, in order to further reduce the signaling overhead of the inactive downlink data transmission process, when the target network device sends downlink small data packets to the target terminal, if there are multiple downlink small data packets, when sending the last downlink small data packet, if the sum of the data size of the downlink small data packet and the data size of the second release message is less than the carrying capacity of the wireless channel, the target network device can add the downlink small data packet to the second release message and send it to the target terminal together with the second release message.

[0411] For ease of understanding, combined with Figure 15 The process of transmitting small data in the inactive state described above will be explained. Figure 15 This is a signaling diagram for a non-active state data transmission process provided in an embodiment of this disclosure.

[0412] In step S1501, the gNB sends an RRC release message to the UE, which includes pause configuration information and an indication of inactive downlink data transmission.

[0413] The current state of the UE described above is connected. The above pause configuration information includes the radio paging cycle. The above pause configuration information may also include CG configuration information.

[0414] In step S1502, the UE switches its current state to the inactive state according to the pause configuration information in the received RRC release message.

[0415] Step S1503: The gNB broadcasts a system message, which includes downlink common configuration information.

[0416] The aforementioned 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 the default paging period.

[0417] In step S1504, the gNB sends a paging message to the UE, which includes a terminal identifier that matches the complete inactive terminal identifier stored by the UE and a designated paging record that includes an inactive downlink data transmission indication.

[0418] In this step, the gNB sends the paging message to the UE using the aforementioned radio paging cycle as the time period. Additionally, the specified paging record may also include a non-contention access preamble.

[0419] In step S1505, the UE receives a paging message sent by the gNB.

[0420] In this step, the UE receives the paging message sent by the target network device with the smaller of the aforementioned wireless paging period and the default paging period as the time period.

[0421] In step S1506, the UE sends an RRC connection recovery request to the gNB. The RRC connection recovery request includes the reason for connection recovery and the uplink small data packet. The reason for connection recovery is: inactive downlink small data transmission.

[0422] The aforementioned RRC connection recovery request also includes a value indicating the access type, such as the access type N mentioned above.

[0423] Depending on whether the RRC release message includes CG configuration information and whether the paging message includes a non-contention access preamble, the UE can send the RRC connection recovery request using random access or a configuration grant type that matches the CG configuration.

[0424] In step S1506 above, when the target terminal does not send uplink data to the target network device, the above-mentioned uplink small data packet will not be included in the RRC connection recovery request.

[0425] In step S1507, after receiving the RRC connection recovery request, the gNB generates feedback information corresponding to the uplink small data packet and sends the downlink small data packet and feedback information to the UE.

[0426] In step S1508, the UE receives downlink small data packets and feedback information.

[0427] Step S1509: The UE sends an uplink small data packet to the gNB.

[0428] In this step, when there are multiple corresponding uplink small data packets for uplink data, the UE will continue to send the remaining unsent uplink small data packets to the gNB after receiving the above feedback information.

[0429] In step S1510, the gNB sends a downlink small data packet to the UE.

[0430] In this step, when multiple downlink small data packets exist for the downlink data, the gNB can continue to send downlink small data packets to the UE after executing step S1058 above.

[0431] In step S1511, the gNB sends an RRC release message to the UE.

[0432] The aforementioned RRC release message includes indication information indicating a state transition.

[0433] When there are multiple corresponding downlink small data packets for the aforementioned downlink data, the aforementioned RRC release message may also include the last downlink small data packet corresponding to the downlink data.

[0434] In steps S1509-S1511 above, the uplink / downlink small data packets are the sub-data packets corresponding to the remaining uplink / downlink data that was not completely transmitted during the initial uplink / downlink small data packet transmission process. Steps S1509 and S1510 can be executed multiple times, with only one small data packet being transmitted each time.

[0435] In step S1512, the UE switches to an inactive state or an idle state based on the received RRC release message.

[0436] In this step, the state of the UE after switching will vary depending on the indication information in the RRC release message.

[0437] Based on the same inventive concept, and according to the data transmission method provided in the above-described embodiments of this disclosure, this disclosure also provides a data transmission device. For example... Figure 16 As shown, Figure 16 This is a first structural schematic diagram of a data transmission device provided in an embodiment of the present disclosure. The data transmission device is applied to a target terminal and specifically includes the following modules.

[0438] The first receiving module 1601 is used to receive paging messages sent by the target network device according to a first time period when the current state of the target terminal is inactive.

[0439] The first sending module 1602 is used to send a connection restoration request to the target network device when the received paging message includes a specified 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 restoration request. The specified paging record includes an inactive downlink small data transmission indication, and the connection restoration reason in the connection restoration request is inactive downlink small data transmission.

[0440] The second receiving module 1603 is used to receive downlink small data packets sent by the target network device.

[0441] Optionally, the paging message includes a paging record list; the paging record list is a list used to record the paging terminal, and the paging record list includes at least one paging record.

[0442] Optionally, the paging record may include the terminal identifier, access type, and inactive downlink data transmission indication of the paging terminal.

[0443] The terminal identifier includes: the NAS layer ID assigned to the terminal by the NAS for core network paging, and the complete inactive terminal identifier for RAN paging; the access type is used to indicate whether the paging message is initiated by a PDU session that is not accessed by 3GPP; and the inactive downlink data transmission indicator is used to indicate that the paging message is used to trigger inactive downlink data transmission.

[0444] Optionally, the paging record may also include a non-contention access preamble that instructs the terminal to initiate non-contention random access.

[0445] Optionally, the above-mentioned data transmission device may further include:

[0446] The parsing module is used to parse each paging record in the received paging message after receiving the paging message sent by the target network device according to the first time period.

[0447] The first determining module is used to determine that for each paging record obtained by parsing, if the complete inactive terminal identifier in the paging record matches the complete inactive terminal identifier stored in the target terminal, and the paging record includes an inactive downlink small data transmission indication, then the paging record is the designated paging record of the target terminal.

[0448] The second determining module is used to determine that the paging record is not the designated paging record of the target terminal if the complete inactive terminal identifier in the paging record does not match the complete inactive terminal identifier stored in the terminal, and / or the paging record does not include an inactive downlink small data transmission indication.

[0449] Optionally, the first sending module 1602 described above can be used to send a connection restoration request to the target network device based on the CG configuration information when the target terminal stores CG configuration information and the received paging message includes a specified paging record of the target terminal.

[0450] Optionally, the first sending module 1602 described above can be specifically used to send a connection restoration request to the target network device through contention access when the received paging message includes a specified paging record of the target terminal and the specified paging record does not include a non-contention access preamble.

[0451] When the received paging message includes a specified paging record of the target terminal, and the specified paging record includes a non-contention access preamble, a connection restoration request is sent to the target network device through non-contention access.

[0452] Optionally, the above-mentioned data transmission device may further include:

[0453] The judgment module is used to determine whether the target terminal meets the preset connection initiation conditions at the current time before sending a connection recovery request to the target network device. The preset connection initiation conditions are: the data volume of the wireless bearer configured for inactive small data transmission is less than the preset data volume threshold and / or an inactive downlink small data transmission indication is received, the downlink RSRP is greater than the preset threshold, and the uplink small data transmission resources are valid.

[0454] The execution module is used to execute the step of sending a connection restoration request to the target network device when the target terminal meets the preset connection initiation conditions.

[0455] Optionally, the above-mentioned preset connection initiation conditions can be expressed as follows: a higher layer above the RRC layer requests the restoration of the RRC connection, SIB1 contains a common configuration for small data transmission, a small data transmission configuration is configured, all uplink small data is mapped to the radio bearer of the small data transmission configuration and / or an inactive downlink small data transmission indication is received, and the lower layer indication below the RRC layer meets the triggering conditions for inactive small data.

[0456] Optionally, the above-mentioned data transmission device may further include:

[0457] The first startup module is used to start a timer for detecting the recovery process of inactive small data transmission when the target terminal meets the preset connection initiation conditions;

[0458] The aforementioned data transmission device may further include:

[0459] The second startup module is used to start a timer for monitoring the inactive state recovery process when the target terminal does not meet the preset connection initiation conditions, and to send a timeout indication to the MAC entity. The timeout indication is used to indicate that the CG timing advance timer in the CG configuration information of the small data transmission has timed out.

[0460] Optionally, the above-mentioned data transmission device may further include:

[0461] The release module is used to release the stored CG configuration information if the target terminal moves from the current RAN cell to another RAN cell and initiates a connection recovery process in the other RAN cell.

[0462] Optionally, the above connection restoration request may be a first connection restoration request or a second connection restoration request;

[0463] The aforementioned first sending module 1602 can be specifically used to select a first connection recovery request as a connection recovery request when the SIB1 sent by the base station indicates that the connection recovery request uses a full recovery identifier; or, when the received SIB1 does not indicate that the full recovery identifier is used, select a second connection recovery request as a connection recovery request.

[0464] Recover preset security information from the stored access layer context information. The preset security information includes: RRC configuration, ROHC status, the mapping relationship between the stored QoS flow and the data resource bearer DRB, the base station root key and the integrity protection key.

[0465] Reconstruct the PDCP entity for SIB1;

[0466] Restore SIB1;

[0467] For each radio bearer configured for inactive small data transmission, the configuration associated with the RLC bearer configured with the primary cell group and PDCP is recovered from the access layer context information, and the PDCP entity is reconstructed for that radio bearer;

[0468] Restore all radio bearers to their inactive small data transmission configuration;

[0469] Send a connection restoration request to the target network device.

[0470] Optionally, the first connection recovery request and the second connection recovery request mentioned above include: a recovery identifier, a recovery integrity check code, and a recovery reason;

[0471] The recovery identifier of the first connection recovery request is the complete inactive terminal identifier stored in the target terminal, and the recovery identifier of the second connection request is the truncated inactive terminal identifier stored in the target terminal; the recovery integrity check code is the authentication token used for terminal authentication at the base station; and the recovery reason is inactive downlink small data transmission.

[0472] Optionally, the above-mentioned data transmission device may further include:

[0473] The third receiving module is used to receive a first release message sent by the target network device when the current state of the target terminal is connected. The first release message includes pause configuration information that instructs the terminal to perform inactive state configuration.

[0474] The first switching module is used to switch the current state to an inactive state based on the pause configuration information.

[0475] Optionally, the above-mentioned pause configuration information may include: complete inactive terminal identifier, truncated inactive terminal identifier, wireless paging cycle, wireless notification area information, timer, next-hop chain count value, and inactive small data transmission configuration information.

[0476] Optionally, the above-mentioned complete inactive terminal identifier and truncated inactive terminal identifier are temporary wireless network identifier values ​​of inactive terminals, used by the target network side to find the anchor node before the terminal enters the inactive state and the access layer context information stored therein. The size of the complete inactive terminal identifier and the truncated inactive terminal identifier are different.

[0477] The aforementioned wireless paging cycle is the RAN paging cycle configured by the RAN-side node for inactive terminals;

[0478] The aforementioned wireless notification area information includes a cell list and a wireless area configuration list. The cell list is configured as a list of cells in the RAN area, and the wireless area configuration list includes the RAN area code or RA code of the RAN area.

[0479] The aforementioned timer is used to trigger the periodic RNAU process in the terminal;

[0480] The above next-hop chain count value is used to calculate the security key after the connection is restored;

[0481] The aforementioned inactive small data transmission configuration information includes: an inactive small data transmission data resource bearer (DRB) list, and a small data transmission signaling radio bearer (SRB2) indication. The inactive small data transmission DRB list indicates the DRB identifier of the small data transmission configuration, and the small data transmission SRB2 indication is used to indicate whether the terminal has an SRB2 for the small data transmission configuration.

[0482] Optionally, the above-mentioned inactive small data transmission configuration information also includes CG configuration information; wherein, the CG configuration authorization information includes: CG SSB RSRP threshold, CG timing advance timer, CG timing advance verification configuration, and CG RSRP change threshold;

[0483] The aforementioned CG SSB RSRP threshold is the RSRP threshold for single-sideband SSB selection based on small data transmission using CG resources;

[0484] The aforementioned CG advance timer is used for timing synchronization of small data transmissions;

[0485] The above CG timed early verification configuration is used for configuring RSRP-based early (TA) verification;

[0486] The aforementioned CG RSRP change threshold is the RSRP threshold used for TA verification of small data transmission.

[0487] Optionally, the aforementioned first handover module can be used to reset the Media Access Control (MAC) and release the default MAC cell group configuration.

[0488] Application pause configuration information;

[0489] When the CG configuration information is included in the pause configuration information, each DRB in the inactive small data transmission DRB list and the small data transmission SRB2 indicator are identified as the DRB and SRB2 of the inactive small data transmission process; for each RLC bearer in the target terminal configuration, the RLC entity is rebuilt; for the restored SRB2 and SRB1, the PDCP entity is triggered to perform the SDU discarding process; small data transmission CG resources are configured for the MAC entity, and the CG timing advance timer is started.

[0490] The current access layer root key KgNB and the integrity protection key KRRCint of RRC signaling, ROHC status, the mapping rules between stored QoS flows and DRB, the C-RNTI used in the source PCell, the cell identifier and the physical cell identifier of the source PCell, the SpCell common configuration in the synchronization reconfiguration message of the NR PSCell, and all other configuration parameters except those 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 SCG of the E-UTRA PSCell, the PSCell configuration in EN-DC, and the serving cell common configuration SIB are stored in the inactive terminal access layer context information.

[0491] Suspend all SRBs and DRBs except SRB0;

[0492] Instruct all lower layers of the DRB to pause PDCP; the lower layers are located below the RRC layer.

[0493] Switch to the inactive state and perform cell reselection.

[0494] Optionally, the above-mentioned data transmission device may further include:

[0495] The fourth receiving module is used to receive system messages broadcast by the target network device. The system messages include downlink transmission frequency information, initial downlink BWP, BCCH configuration information, and PCCH configuration information.

[0496] Optionally, the aforementioned downlink transmission frequency information is used to indicate the transmission frequency of downlink small data packets;

[0497] The above initial downlink BWP is the initial downlink BWP configuration for the primary cell;

[0498] The above BCCH configuration information is related to modifying the system message passing cycle;

[0499] The aforementioned PCCH configuration information includes the default paging period, the number and configuration of paging frames, the number of paging opportunities, and the first PDCCH listening opportunity. The default paging period is the default paging period broadcast in the system message. The number and configuration of paging frames are used to derive the total number of paging frames and the paging frame offset. The number of paging opportunities is used to indicate the number of paging opportunities in each paging frame. A paging opportunity is a set of PDCCH listening opportunities, consisting of multiple time slots for sending paging control information. The first PDCCH listening opportunity is the first PDCCH listening opportunity used to listen for paging opportunities in a paging frame.

[0500] Optionally, the above-mentioned data transmission device may further include:

[0501] The third determining module is used to determine the smaller value between the wireless paging period and the default paging period as the first time period for receiving paging messages when the target terminal is in an inactive state.

[0502] Optionally, the connection restoration request may also include uplink small data packets;

[0503] The second receiving module 1603 mentioned above can be used to receive downlink small data packets sent by the target network device, as well as feedback information sent by the target network device in response to uplink small data packets.

[0504] Optionally, the above-mentioned data transmission device may further include:

[0505] The fifth receiving module is used to receive the second release message sent by the target network device when the downlink small data packet transmission is completed. The second release message includes indication information indicating a state switch.

[0506] The second switching module is used to switch the current state to an inactive state or an idle state based on the indication information.

[0507] Based on the same inventive concept, and according to the data transmission method provided in the above-described embodiments of this disclosure, this disclosure also provides a data transmission device. For example... Figure 17 As shown, Figure 17 This is a second structural schematic diagram of a data transmission apparatus provided in an embodiment of the present disclosure. The data transmission apparatus is applied to a target network device and specifically includes the following modules:

[0508] The second sending module 1701 is used to send paging messages to the target terminal whose current state is inactive according to the second time period;

[0509] The sixth receiving module 1702 is used to receive a connection restoration request sent by the target terminal. The connection restoration request is sent by the target terminal when it receives a paging message that includes its own specified paging record. The specified paging record includes an inactive downlink data transmission indication, and the connection restoration reason in the connection restoration request is inactive downlink data transmission.

[0510] The third sending module 1703 is used to send downlink small data packets to the target terminal based on the connection restoration request, so that the target terminal can receive the downlink small data packets.

[0511] Optionally, the paging message includes a paging record list; the paging record list is a list used to record the paging terminal, and the paging record list includes at least one paging record.

[0512] Optionally, the paging record may include the terminal identifier, access type, and inactive downlink data transmission indication of the paging terminal.

[0513] The aforementioned terminal identifiers include: the NAS layer ID assigned to the terminal by the NAS for core network paging, and the complete inactive terminal identifier for RAN paging; the access type is used to indicate whether the paging message is initiated by a PDU session that is not accessed by 3GPP; and the inactive downlink data transmission indicator is used to indicate that the paging message is used to trigger inactive downlink data transmission.

[0514] Optionally, the paging record may also include a non-contention access preamble that instructs the terminal to initiate non-contention random access.

[0515] Optionally, the connection recovery request can be a first connection recovery request or a second connection recovery request; the first connection recovery request is sent by the target terminal when the SIB1 sent by the base station indicates that the connection recovery request uses the full recovery identifier, and the second connection recovery request is sent by the target terminal when the SIB1 sent by the base station does not indicate that the connection recovery request uses the full recovery identifier.

[0516] Optionally, the first connection recovery request and the second connection recovery request mentioned above include: a recovery identifier, a recovery integrity check code, and a recovery reason;

[0517] The recovery identifier of the first connection recovery request is the complete inactive terminal identifier stored in the target terminal, and the recovery identifier of the second connection request is the truncated inactive terminal identifier stored in the target terminal; the recovery integrity check code is the authentication token used for terminal authentication at the base station; and the recovery reason is inactive downlink small data transmission.

[0518] Optionally, the above-mentioned data transmission device may further include:

[0519] The fourth sending module is used to send a first release message to the terminal. The first release message includes pause configuration information that instructs the terminal to perform inactive state configuration, so that the target terminal switches the current state to inactive state based on the pause configuration information.

[0520] Optionally, the above-mentioned pause configuration information includes: complete inactive terminal identifier, truncated inactive terminal identifier, wireless paging cycle, wireless notification area information, timer, next-hop chain count value, and inactive small data transmission configuration information.

[0521] Optionally, the above-mentioned complete inactive terminal identifier and truncated inactive terminal identifier are temporary wireless network identifier values ​​of inactive terminals, used by the target network side to find the anchor node before the terminal enters the inactive state and the access layer context information stored therein. The size of the complete inactive terminal identifier and the truncated inactive terminal identifier are different.

[0522] The aforementioned wireless paging cycle is the RAN paging cycle configured by the RAN-side node for inactive terminals;

[0523] The aforementioned wireless notification area information includes a cell list and a wireless area configuration list. The cell list is configured as a list of cells in the RAN area, and the wireless area configuration list includes the RAN area code or RA code of the RAN area.

[0524] The aforementioned timer is used to trigger the periodic RNAU process in the terminal;

[0525] The above next-hop chain count value is used to calculate the security key after the connection is restored;

[0526] The aforementioned inactive small data transmission configuration information includes: an inactive small data transmission data resource bearer (DRB) list, and a small data transmission signaling radio bearer (SRB2) indication. The inactive small data transmission DRB list indicates the DRB identifier of the small data transmission configuration, and the small data transmission SRB2 indication is used to indicate whether the terminal has an SRB2 for the small data transmission configuration.

[0527] Optionally, the above-mentioned inactive small data transmission configuration information also includes CG configuration information; wherein, the CG configuration authorization information includes: CG SSB RSRP threshold, CG timing advance timer, CG timing advance verification configuration, and CG RSRP change threshold;

[0528] The aforementioned CG SSB RSRP threshold is the RSRP threshold for SSB selection based on small data transfers using CG resources;

[0529] The aforementioned CG advance timer is used for timing synchronization of small data transmissions;

[0530] The above CG timed early verification configuration is used for RSRP-based TA verification configuration;

[0531] The aforementioned CG RSRP change threshold is the RSRP threshold used for TA verification of small data transmission.

[0532] Optionally, the above-mentioned data transmission device may further include:

[0533] The broadcast module is used to broadcast system messages, which include downlink transmission frequency information, initial downlink BWP, BCCH configuration information, and PCCH configuration information.

[0534] Optionally, the aforementioned downlink transmission frequency information is used to indicate the transmission frequency of downlink small data packets;

[0535] The above initial downlink BWP is the initial downlink BWP configuration for the primary cell;

[0536] The above BCCH configuration information is related to modifying the system message passing cycle;

[0537] The aforementioned PCCH configuration information includes the default paging period, the number and configuration of paging frames, the number of paging opportunities, and the first PDCCH listening opportunity. The default paging period is the default paging period broadcast in the system message. The number and configuration of paging frames are used to derive the total number of paging frames and the paging frame offset. The number of paging opportunities is used to indicate the number of paging opportunities in each paging frame. A paging opportunity is a set of PDCCH listening opportunities, consisting of multiple time slots for sending paging control information. The first PDCCH listening opportunity is the first PDCCH listening opportunity used to listen for paging opportunities in a paging frame.

[0538] Optionally, the above-mentioned data transmission device may further include:

[0539] The fourth determining module is used to determine the default paging period as the second time period for sending paging messages.

[0540] Optionally, the connection restoration request may also include uplink small data packets;

[0541] The aforementioned third sending module 1703 can be specifically used to generate feedback information for uplink small data packets and obtain downlink small data packets when a connection restoration request is received; send downlink small data packets and feedback information to the target terminal.

[0542] Optionally, the above-mentioned data transmission device may further include:

[0543] The fifth sending module is used to send a second release message to the target terminal when the downlink small data packet transmission is completed. The second release message includes indication information indicating a state switch, so that the target terminal switches the current state to an inactive state or a spatial state based on the indication information.

[0544] With the apparatus provided in this embodiment, when the target terminal is in an inactive state, if the target terminal receives a paging message from the target network device that includes its own designated paging record, it can send a connection restoration request to the target network device, thereby triggering 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 restoration request, and the target terminal will also receive the downlink small data packet, thus realizing the downlink small data transmission process of the inactive terminal.

[0545] Furthermore, compared to related technologies where inactive terminals must switch to connected mode to transmit data, this embodiment introduces a new terminal access type, namely inactive downlink small data transmission, by specifying an inactive downlink data transmission indication in the paging record. This allows the terminal to receive downlink small data packets sent by the target network device in an inactive state, avoiding the signaling overhead and latency caused by switching from inactive to connected mode. This improves the transmission efficiency of downlink small data packets and saves signaling overhead, effectively reducing signaling overhead and latency during data transmission.

[0546] Based on the same inventive concept, and according to the data transmission method provided in the above-described embodiments of this disclosure, this disclosure also provides a data transmission system. For example... Figure 18 As shown, Figure 18 This is a schematic diagram of a data transmission system provided in an embodiment of this disclosure. Figure 18The system shown includes target terminal 1801 and target network device 1802.

[0547] The aforementioned target terminal 1801 is used to execute the above... Figures 1-10 The method shown;

[0548] The aforementioned target network device 1802 is used to perform the above... Figures 11-14 The method shown.

[0549] With the system provided in this embodiment, when the target terminal is in an inactive state, if the target terminal receives a paging message from the target network device that includes its own designated paging record, it can send a connection restoration request to the target network device, thereby triggering 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 restoration request, and the target terminal will also receive the downlink small data packet, thus realizing the downlink small data transmission process of the inactive terminal.

[0550] Furthermore, compared to related technologies where inactive terminals must switch to connected mode to transmit data, this embodiment introduces a new terminal access type, namely inactive downlink small data transmission, by specifying an inactive downlink data transmission indication in the paging record. This allows the terminal to receive downlink small data packets sent by the target network device in an inactive state, avoiding the signaling overhead and latency caused by switching from inactive to connected mode. This improves the transmission efficiency of downlink small data packets and saves signaling overhead, effectively reducing signaling overhead and latency during data transmission.

[0551] Based on the same inventive concept, and according to the data transmission method provided in the above embodiments of this disclosure, this disclosure also provides a target terminal, such as... Figure 19 As shown, it includes a processor 1901, a communication interface 1902, a memory 1903, and a communication bus 1904. The processor 1901, communication interface 1902, and memory 1903 communicate with each other via the communication bus 1904.

[0552] Memory 1903 is used to store computer programs;

[0553] When processor 1901 executes a program stored in memory 1903, it performs the following steps:

[0554] When the target terminal is inactive, the paging message sent by the target network device is received according to the first time period.

[0555] When the received paging message includes a specified paging record of the target terminal, a connection restoration request is sent to the target network device so that the target network device sends a downlink small data packet to the target terminal based on the received connection restoration request. The specified paging record includes an inactive downlink small data transmission indication, and the connection restoration reason in the connection restoration request is inactive downlink small data transmission.

[0556] Receive downlink small data packets sent by the target network device.

[0557] Based on the same inventive concept, and according to the data transmission method provided in the above embodiments of this disclosure, this disclosure also provides a target network device, such as... Figure 20 As shown, it includes a processor 2001, a communication interface 2002, a memory 2003, and a communication bus 2004. The processor 2001, communication interface 2002, and memory 2003 communicate with each other via the communication bus 2004.

[0558] Memory 2003 is used to store computer programs;

[0559] When processor 2001 executes a program stored in memory 2003, it performs the following steps:

[0560] According to the second time period, a paging message is sent to the target terminal that is currently inactive.

[0561] Receive a connection restoration request sent by the target terminal. The connection restoration request is sent by the target terminal when it receives a paging message that includes its own specified paging record. The specified paging record includes an inactive downlink data transmission indication. The reason for connection restoration in the connection restoration request is inactive downlink data transmission.

[0562] Based on the connection restoration request, a downlink small data packet is sent to the target terminal so that the target terminal can receive the downlink small data packet.

[0563] With the target terminal and target network device provided in this disclosure embodiment, when the target terminal is in an inactive state, if the target terminal receives a paging message from the target network device that includes its own designated paging record, it can send a connection restoration request to the target network device, thereby triggering 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 restoration request, and the target terminal will also receive the downlink small data packet, thus realizing the downlink small data transmission process of the inactive terminal.

[0564] Furthermore, compared to related technologies where inactive terminals must switch to connected mode to transmit data, this embodiment introduces a new terminal access type, namely inactive downlink small data transmission, by specifying an inactive downlink data transmission indication in the paging record. This allows the terminal to receive downlink small data packets sent by the target network device in an inactive state, avoiding the signaling overhead and latency caused by switching from inactive to connected mode. This improves the transmission efficiency of downlink small data packets and saves signaling overhead, effectively reducing signaling overhead and latency during data transmission.

[0565] The communication bus mentioned in the target terminal and target network device above can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc. For ease of representation, only one thick line is used in the diagram, but this does not indicate that there is only one bus or one type of bus.

[0566] The communication interface is used for communication between the aforementioned target terminal and target network device and other devices.

[0567] The memory may include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0568] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0569] Based on the same inventive concept, and according to the data transmission method provided in the above-described embodiments of this disclosure, this disclosure also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of any of the above-described data transmission methods.

[0570] Based on the same inventive concept, and according to the data transmission method provided in the above-described embodiments of this disclosure, this disclosure also provides a computer program product containing instructions that, when run on a computer, causes the computer to execute any of the data transmission methods described in the above embodiments.

[0571] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this disclosure are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., a solid-state disk (SSD)).

[0572] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0573] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for embodiments such as apparatus, systems, target terminals, target network devices, computer-readable storage media, and computer program products, since they are basically similar to the method embodiments, the descriptions are relatively simple, and relevant parts can be referred to the descriptions of the method embodiments.

[0574] The above description is merely a preferred embodiment of this disclosure and is not intended to limit the scope of protection of this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure are included within the scope of protection of this disclosure.

Claims

1. A data transmission method, characterized in that, Applied to a target terminal, the method includes: When the current state of the target terminal is connected, a first release message is received from the target network device, the first release message including configuration authorization CG configuration information; When the current state of the target terminal is inactive, a paging message sent by the target network device is received. The paging message includes a paging record list, and the paging record list includes at least one paging record. For each paging record, if the Full Inactive Terminal I-RNTI in the paging record matches the Full Inactive Terminal I-RNTI stored in the target terminal, and the paging record includes an inactive downlink small data transmission indication, then a connection recovery request is sent to the target network device based on the CG configuration information. The connection recovery request includes a connection recovery reason, or the connection recovery request includes a connection recovery reason and an uplink small data packet. The inactive downlink small data transmission indication is used to indicate that the paging message is used to trigger inactive downlink data transmission, and the connection recovery reason in the connection recovery request is inactive downlink small data transmission. In an inactive state, receive downlink small data packets sent by the target network device; or in an inactive state, receive downlink small data packets sent by the target network device, as well as feedback information sent by the target network device in response to the uplink small data packets.

2. The method according to claim 1, characterized in that, The paging record includes the terminal identifier, access type, and inactive downlink data transmission indication of the paging terminal; The terminal identifier includes: a NAS layer identifier ID assigned to the terminal by the Non-Access Stratum (NAS) for core network paging, and a complete inactive terminal identifier for Radio Access Network (RAN) paging; the access type is used to indicate whether the paging message is initiated by a Protocol Data Unit (PDU) session that is not accessed by the 3GPP (3rd Generation Partnership Project).

3. The method according to claim 1, characterized in that, The paging record also includes a non-contention access preamble that instructs the terminal to initiate non-contention random access.

4. The method according to claim 1, characterized in that, If the target terminal does not store configuration authorization CG configuration information, then when the received paging message includes the specified paging record of the target terminal, the step of sending a connection restoration request to the target network device includes: When the received paging message includes a designated paging record of the target terminal, and the designated paging record does not include a non-contention access preamble, a connection recovery request is sent to the target network device through contention access. When the received paging message includes a designated paging record of the target terminal, and the designated paging record includes the non-contention access preamble, a connection recovery request is sent to the target network device via non-contention access.

5. The method according to claim 1, characterized in that, Before sending a connection restoration request to the target network device, the method further includes: Determine whether the target terminal meets the preset connection initiation conditions at the current moment. The preset connection initiation conditions are: the data volume of the wireless bearer configured for inactive small data transmission is less than a preset data volume threshold and / or the inactive downlink small data transmission indication is received, the downlink reference signal received power (RSRP) is greater than a preset threshold, and the uplink small data transmission resources are valid. When the target terminal meets the preset connection initiation conditions, the step of sending a connection recovery request to the target network device is executed.

6. The method according to claim 5, characterized in that, The preset connection initiation conditions are as follows: a higher layer above the Radio Resource Control (RRC) layer requests the restoration of the RRC connection; SIB1 contains a common configuration for small data transmission; a small data transmission configuration is configured; all uplink small data is mapped to the radio bearer of the small data transmission configuration and / or an inactive downlink small data transmission indication is received; and a lower layer indication below the RRC layer satisfies the triggering conditions for inactive small data.

7. The method according to claim 5 or 6, characterized in that, The method further includes: When the target terminal meets the preset connection initiation conditions, a timer is started to detect the recovery process of inactive small data transmission. The method further includes: When the target terminal does not meet the preset connection initiation conditions, a timer for monitoring the inactive state recovery process is started, and a timeout indication is sent to the MAC entity. The timeout indication is used to indicate that the CG timing advance timer in the configuration authorization CG configuration information for small data transmission has timed out.

8. The method according to claim 1, characterized in that, The method further includes: If the target terminal moves from the current Radio Access Network (RAN) cell to another RAN cell and initiates a connection recovery process in that other RAN cell, the stored configuration authorization (CG) configuration information is released.

9. The method according to claim 1, characterized in that, The connection recovery request is either a first connection recovery request or a second connection recovery request; The step of sending a connection restoration request to the target network device includes: When the SIB1 sent by the base station indicates that the connection recovery request uses the full recovery identifier, the first connection recovery request is selected as the connection recovery request; or, when the received SIB1 does not indicate that the full recovery identifier is used, the second connection recovery request is selected as the connection recovery request. Recover preset security information from the stored access layer context information. The preset security information includes: Radio Resource Control (RRC) configuration, Robust Header Compression (ROHC) status, the mapping relationship between the stored Quality of Service (QoS) flow and the Data Resource Bearer (DRB), the base station root key, and the integrity protection key. The SIB1 reconstruction packet data aggregation protocol PDCP entity; Restore SIB1; For each radio bearer configured for inactive small data transmission, the configuration associated with the Radio Link Layer Control Protocol (RLC) bearer configured with the primary cell group and PDCP is recovered from the access layer context information, and the PDCP entity is reconstructed for that radio bearer; Restore all radio bearers to their inactive small data transmission configuration; The connection restoration request is sent to the target network device.

10. The method according to claim 9, characterized in that, The first connection recovery request and the second connection recovery request include: a recovery identifier, a recovery integrity check code, and a recovery reason; Wherein, the recovery identifier of the first connection recovery request is the complete inactive terminal identifier stored by the target terminal, and the recovery identifier of the second connection recovery request is the truncated inactive terminal identifier stored by the target terminal; the recovery integrity check code is the authentication token used for terminal authentication at the base station; and the recovery reason is the inactive downlink small data transmission.

11. The method according to claim 1, characterized in that, The first release message includes pause configuration information instructing the terminal to perform inactive state configuration; the method further includes: Based on the pause configuration information, the current state is switched to the inactive state.

12. The method according to claim 11, characterized in that, The pause configuration information includes: complete inactive terminal identifier, truncated inactive terminal identifier, wireless paging cycle, wireless notification area information, timer, next-hop chain count value, and inactive small data transmission configuration information.

13. The method according to claim 12, characterized in that, The complete inactive terminal identifier and the truncated inactive terminal identifier are temporary wireless network identifier values ​​for inactive terminals, used by the target network side to find the anchor node before the terminal enters the inactive state and its stored access layer context information. The complete inactive terminal identifier and the truncated inactive terminal identifier have different sizes. The wireless paging cycle is the RAN paging cycle configured by the RAN-side node for the inactive terminal. The wireless notification area information includes a cell list and a wireless area configuration list, wherein the cell list is configured as a list of cells in the RAN area, and the wireless area configuration list includes the RAN area code or random access RA code of the RAN area; The timer is used to trigger the periodic notification region update RNAU process in the terminal; The next-hop chain count value is used to calculate the security key after the connection is restored; The inactive small data transmission configuration information includes: an inactive small data transmission data resource bearer (DRB) list and a small data transmission signaling radio bearer (SRB2) indication. The inactive small data transmission DRB list indicates the DRB identifier of the small data transmission configuration, and the small data transmission SRB2 indication is used to indicate whether the terminal has an SRB2 configured for small data transmission.

14. The method according to claim 13, characterized in that, The inactive small data transmission configuration information also includes configuration authorization CG configuration information; wherein, the CG configuration authorization information includes: CG SSB RSRP threshold, CG timing advance timer, CG timing advance verification configuration, and CG RSRP change threshold; The CG SSB RSRP threshold is the reference signal received power RSRP threshold for single-sideband SSB selection based on CG resources for small data transmission. The CG advance timer is used for timed synchronization of small data transmissions; The CG timed early verification configuration is used for configuring early TA verification based on RSRP; The CG RSRP change threshold is the RSRP threshold used for TA verification of small data transmission.

15. The method according to claim 14, characterized in that, The step of switching the current state to an inactive state based on the pause configuration information includes: Reset the Media Access Control MAC and release the default MAC cell group configuration; Apply the aforementioned pause configuration information; When the CG configuration information is included in the pause configuration information, each DRB in the inactive small data transmission DRB list and the small data transmission SRB2 indication are identified as the DRB and SRB2 of the inactive small data transmission process; for each Radio Link Layer Control Protocol (RLC) bearer in the target terminal configuration, the RLC entity is rebuilt; for the recovered SRB2 and SRB1, the Packet Data Convergence Protocol (PDCP) entity is triggered to perform the Session Data Unit (SDU) discarding process; small data transmission CG resources are configured for the MAC entity, and the CG timing advance timer is started. The current access layer root key KgNB and the integrity protection key KRRCint of the radio resource control (RRC) signaling, the robust header compression (ROHC) state, the mapping rules between the stored quality of service (QoS) stream and data resource bearer (DRB), the cell radio network temporary identifier (C-RNTI) used in the source primary cell (PCell), the cell identifier and the physical cell identifier of the source PCell, the special cell SpCell common configuration in the synchronization reconfiguration message of the primary and secondary NR PSCells of the New Radio Interface, and all other configuration parameters except those in the synchronization reconfiguration message of the PCell, 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 in the EN-DC, and the serving cell common configuration (SIB) are stored in the inactive terminal access layer context information. Suspend all SRBs and DRBs except SRB0; Instruct all lower layers of the DRB to pause PDCP, which are located below the RRC layer; Switch to the inactive state and perform cell reselection.

16. The method according to claim 1, characterized in that, The method further includes: The system message broadcast by the target network device is received. The system message includes downlink transmission frequency information, initial downlink bandwidth portion (BWP), broadcast control channel (BCCH) configuration information, and paging channel (PCCH) configuration information.

17. The method according to claim 16, characterized in that, 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 related to modifying the system message passing cycle; The PCCH configuration information includes a default paging period, the number and configuration of paging frames, the number of paging opportunities, and the first physical downlink control channel (PDCCH) listening opportunity. The default paging period is the default paging period broadcast in the system message. The number and configuration of paging frames are used to derive the total number of paging frames and the paging frame offset. The number of paging opportunities is used to indicate the number of paging opportunities in each paging frame. The paging opportunity is a set of PDCCH listening opportunities, consisting of multiple time slots for sending paging control information. The first PDCCH listening opportunity is the first PDCCH listening opportunity used to listen for paging opportunities in the paging frame.

18. The method according to claim 15, characterized in that, The method further includes: The smaller value between the wireless paging period and the default paging period is determined as the first time period for receiving paging messages when the target terminal is in an inactive state.

19. The method according to claim 1, characterized in that, The method further includes: The target network device receives a second release message when the downlink small data packet transmission is completed, the second release message including indication information indicating a state switch; Based on the indicated information, the current state is switched to an inactive state or an idle state.

20. A data transmission method, characterized in that, Applied to a target network device, the method includes: A first release message is sent to the target terminal whose current state is connected. The first release message includes configuration authorization CG configuration information. According to the second time period, a paging message is sent to the target terminal whose current state is inactive. After receiving the paging message, the target terminal, for each paging record, if the Full Inactive Terminal I-RNTI in the paging record matches the Full Inactive Terminal I-RNTI stored in the target terminal, and the paging record includes an inactive downlink small data transmission indication, then a connection recovery request is sent to the target network device based on the CG configuration information. The paging message includes a paging record list, and the paging record list includes at least one paging record. The system receives a connection recovery request sent by the target terminal. The connection recovery request includes a connection recovery reason and an uplink small data packet. The connection recovery request is sent by the target terminal when it receives a paging message that includes its own designated paging record. The designated paging record includes an inactive downlink data transmission indication. The inactive downlink small data transmission indication is used to indicate that the paging message is used to trigger inactive downlink data transmission. The connection recovery reason in the connection recovery request is inactive downlink data transmission. Based on the connection restoration request, feedback information is generated for the uplink small data packet, and downlink small data packets are obtained. The downlink small data packets and the feedback information are then sent to the target terminal so that the target terminal can receive the downlink small data packets.

21. The method according to claim 20, characterized in that, The paging record includes the terminal identifier, access type, and inactive downlink data transmission indication of the paging terminal; The terminal identifier includes: a NAS layer identifier ID assigned to the terminal by the Non-Access Stratum (NAS) for core network paging, and a complete inactive terminal identifier for Radio Access Network (RAN) paging; the access type is used to indicate whether the paging message is initiated by a Protocol Data Unit (PDU) session that is not accessed by the 3GPP (3rd Generation Partnership Project).

22. The method according to claim 20, characterized in that, The paging record also includes a non-contention access preamble that instructs the terminal to initiate non-contention random access.

23. The method according to claim 20, characterized in that, The connection recovery request can be a first connection recovery request or a second connection recovery request; the first connection recovery request is sent by the target terminal when the SIB1 sent by the base station indicates that the connection recovery request uses the full recovery identifier, and the second connection recovery request is sent by the target terminal when the SIB1 sent by the base station does not indicate that the connection recovery request uses the full recovery identifier.

24. The method according to claim 23, characterized in that, The first connection recovery request and the second connection recovery request include: a recovery identifier, a recovery integrity check code, and a recovery reason; Wherein, the recovery identifier of the first connection recovery request is the complete inactive terminal identifier stored by the target terminal, and the recovery identifier of the second connection recovery request is the truncated inactive terminal identifier stored by the target terminal; the recovery integrity check code is the authentication token used for terminal authentication at the base station; and the recovery reason is the inactive downlink small data transmission.

25. The method according to claim 20, characterized in that, The first release message includes pause configuration information instructing the terminal to perform inactive state configuration. Based on the pause configuration information, the target terminal switches its current state to inactive state.

26. The method according to claim 25, characterized in that, The pause configuration information includes: complete inactive terminal identifier, truncated inactive terminal identifier, wireless paging cycle, wireless notification area information, timer, next-hop chain count value, and inactive small data transmission configuration information.

27. The method according to claim 26, characterized in that, The complete inactive terminal identifier and the truncated inactive terminal identifier are temporary wireless network identifier values ​​for inactive terminals, used by the target network side to find the anchor node before the terminal enters the inactive state and its stored access layer context information. The complete inactive terminal identifier and the truncated inactive terminal identifier have different sizes. The wireless paging cycle is the RAN paging cycle configured by the RAN-side node for the inactive terminal. The wireless notification area information includes a cell list and a wireless area configuration list, wherein the cell list is configured as a list of cells in the RAN area, and the wireless area configuration list includes the RAN area code or random access RA code of the RAN area; The timer is used to trigger the periodic notification region update RNAU process in the terminal; The next-hop chain count value is used to calculate the security key after the connection is restored; The inactive small data transmission configuration information includes: an inactive small data transmission data resource bearer (DRB) list and a small data transmission signaling radio bearer (SRB2) indication. The inactive small data transmission DRB list indicates the DRB identifier of the small data transmission configuration, and the small data transmission SRB2 indication is used to indicate whether the terminal has an SRB2 configured for small data transmission.

28. The method according to claim 27, characterized in that, The inactive small data transmission configuration information also includes configuration authorization CG configuration information; wherein, the CG configuration authorization information includes: CG SSB RSRP threshold, CG timing advance timer, CG timing advance verification configuration, and CG RSRP change threshold; The CG SSB RSRP threshold is the reference signal received power RSRP threshold for single-sideband SSB selection based on CG resources for small data transmission. The CG advance timer is used for timed synchronization of small data transmissions; The CG timed early verification configuration is used for configuring early TA verification based on RSRP; The CG RSRP change threshold is the RSRP threshold used for TA verification of small data transmission.

29. The method according to claim 20, characterized in that, The method further includes: The system message includes downlink transmission frequency information, initial downlink bandwidth portion (BWP), broadcast control channel (BCCH) configuration information, and paging channel (PCCH) configuration information.

30. The method according to claim 29, characterized in that, 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 related to modifying the system message passing cycle; The PCCH configuration information includes a default paging period, the number and configuration of paging frames, the number of paging opportunities, and the first physical downlink control channel (PDCCH) listening opportunity. The default paging period is the default paging period broadcast in the system message. The number and configuration of paging frames are used to derive the total number of paging frames and the paging frame offset. The number of paging opportunities is used to indicate the number of paging opportunities in each paging frame. The paging opportunity is a set of PDCCH listening opportunities, consisting of multiple time slots for sending paging control information. The first PDCCH listening opportunity is the first PDCCH listening opportunity used to listen for paging opportunities in the paging frame.

31. The method according to claim 30, characterized in that, The method further includes: The default paging period is determined as the second time period for sending the paging message.

32. The method according to claim 20, characterized in that, The method further includes: When the downlink small data packet transmission is completed, a second release message is sent to the target terminal. The second release message includes indication information indicating a state switch, so that the target terminal switches its current state to an inactive state or an idle state based on the indication information.

33. A data transmission device, characterized in that, Applied to a target terminal, the device includes: The third receiving module is used to receive a first release message sent by the target network device when the current state of the target terminal is connected. The first release message includes configuration authorization CG configuration information. The first receiving module is configured to receive a paging message sent by the target network device when the current state of the target terminal is inactive. The paging message includes a paging record list, and the paging record list includes at least one paging record. The first sending module is configured to, for each paging record, if the Full Inactive Terminal I-RNTI in the paging record matches the Full Inactive Terminal I-RNTI stored in the target terminal, and the paging record includes an inactive downlink small data transmission indication, then send a connection recovery request to the target network device based on the CG configuration information. The connection recovery request includes a connection recovery reason, or the connection recovery request includes a connection recovery reason and an uplink small data packet. The inactive downlink small data transmission indication is used to indicate that the paging message is used to trigger inactive downlink data transmission, and the connection recovery reason in the connection recovery request is inactive downlink small data transmission. The second receiving module is used to receive downlink small data packets sent by the target network device; or to receive downlink small data packets sent by the target network device, and feedback information sent by the target network device in response to the uplink small data packets.

34. The apparatus according to claim 33, characterized in that, The paging record includes the terminal identifier, access type, and inactive downlink data transmission indication of the paging terminal; The terminal identifier includes: a NAS layer identifier ID assigned to the terminal by the Non-Access Stratum (NAS) for core network paging, and a complete inactive terminal identifier for Radio Access Network (RAN) paging; the access type is used to indicate whether the paging message is initiated by a Protocol Data Unit (PDU) session that is not accessed by the 3GPP (3rd Generation Partnership Project).

35. The apparatus according to claim 33, characterized in that, The paging record also includes a non-contention access preamble that instructs the terminal to initiate non-contention random access.

36. The apparatus according to claim 33, characterized in that, The first sending module is further configured to send a connection recovery request to the target network device in a contention access manner if the target terminal does not store configuration authorization CG configuration information, and the received paging message includes a specified paging record of the target terminal, and the specified paging record does not include a non-contention access preamble. When the received paging message includes a designated paging record of the target terminal, and the designated paging record includes the non-contention access preamble, a connection recovery request is sent to the target network device via non-contention access.

37. The apparatus according to claim 33, characterized in that, The device further includes: The judgment module is used to determine whether the target terminal meets the preset connection initiation conditions at the current time before sending a connection recovery request to the target network device. The preset connection initiation conditions are: the data volume of the wireless bearer configured for inactive small data transmission is less than a preset data volume threshold and / or the inactive downlink small data transmission indication is received, the downlink reference signal received power (RSRP) is greater than a preset threshold, and the uplink small data transmission resources are valid. An execution module is used to execute the step of sending a connection recovery request to the target network device when the target terminal meets the preset connection initiation conditions.

38. The apparatus according to claim 37, characterized in that, The preset connection initiation conditions are as follows: a higher layer above the Radio Resource Control (RRC) layer requests the restoration of the RRC connection; SIB1 contains a common configuration for small data transmission; a small data transmission configuration is configured; all uplink small data is mapped to the radio bearer of the small data transmission configuration and / or an inactive downlink small data transmission indication is received; and a lower layer indication below the RRC layer satisfies the triggering conditions for inactive small data.

39. The apparatus according to claim 37 or 38, characterized in that, The device further includes: The first startup module is used to start a timer for detecting the recovery process of inactive small data transmission when the target terminal meets the preset connection initiation conditions; The device further includes: The second startup module is used to start a timer for monitoring the inactive state recovery process when the target terminal does not meet the preset connection initiation conditions, and send a timeout indication to the MAC entity. The timeout indication is used to indicate that the CG timer in the configuration authorization CG configuration information for small data transmission has timed out.

40. The apparatus according to claim 33, characterized in that, The device further includes: The release module is used to release the stored configuration authorization CG configuration information if the target terminal moves from the current radio access network RAN ​​cell to another RAN cell and initiates a connection recovery process in the other RAN cell.

41. The apparatus according to claim 33, characterized in that, The connection recovery request is either a first connection recovery request or a second connection recovery request; The first sending module is specifically configured to select the first connection recovery request as the connection recovery request when the SIB1 sent by the base station indicates that the connection recovery request uses the full recovery identifier; or, when the received SIB1 does not indicate that the full recovery identifier is used, select the second connection recovery request as the connection recovery request. Recover preset security information from the stored access layer context information. The preset security information includes: Radio Resource Control (RRC) configuration, Robust Header Compression (ROHC) status, the mapping relationship between the stored Quality of Service (QoS) flow and the Data Resource Bearer (DRB), the base station root key, and the integrity protection key. The SIB1 reconstruction packet data aggregation protocol PDCP entity; Restore SIB1; For each radio bearer configured for inactive small data transmission, the configuration associated with the Radio Link Layer Control Protocol (RLC) bearer configured with the primary cell group and PDCP is recovered from the access layer context information, and the PDCP entity is reconstructed for that radio bearer; Restore all radio bearers to their inactive small data transmission configuration; The connection restoration request is sent to the target network device.

42. The apparatus according to claim 41, characterized in that, The first connection recovery request and the second connection recovery request include: a recovery identifier, a recovery integrity check code, and a recovery reason; Wherein, the recovery identifier of the first connection recovery request is the complete inactive terminal identifier stored by the target terminal, and the recovery identifier of the second connection recovery request is the truncated inactive terminal identifier stored by the target terminal; the recovery integrity check code is the authentication token used for terminal authentication at the base station; and the recovery reason is the inactive downlink small data transmission.

43. The apparatus according to claim 33, characterized in that, The first release message includes pause configuration information instructing the terminal to perform inactive state configuration; the device further includes: The first switching module is used to switch the current state to an inactive state based on the pause configuration information.

44. The apparatus according to claim 43, characterized in that, The pause configuration information includes: complete inactive terminal identifier, truncated inactive terminal identifier, wireless paging cycle, wireless notification area information, timer, next-hop chain count value, and inactive small data transmission configuration information.

45. The apparatus according to claim 44, characterized in that, The complete inactive terminal identifier and the truncated inactive terminal identifier are temporary wireless network identifier values ​​for inactive terminals, used by the target network side to find the anchor node before the terminal enters the inactive state and its stored access layer context information. The complete inactive terminal identifier and the truncated inactive terminal identifier have different sizes. The wireless paging cycle is the RAN paging cycle configured by the RAN-side node for the inactive terminal. The wireless notification area information includes a cell list and a wireless area configuration list, wherein the cell list is configured as a list of cells in the RAN area, and the wireless area configuration list includes the RAN area code or random access RA code of the RAN area; The timer is used to trigger the periodic notification region update RNAU process in the terminal; The next-hop chain count value is used to calculate the security key after the connection is restored; The inactive small data transmission configuration information includes: an inactive small data transmission data resource bearer (DRB) list and a small data transmission signaling radio bearer (SRB2) indication. The inactive small data transmission DRB list indicates the DRB identifier of the small data transmission configuration, and the small data transmission SRB2 indication is used to indicate whether the terminal has an SRB2 configured for small data transmission.

46. ​​The apparatus according to claim 44, characterized in that, The inactive small data transmission configuration information also includes configuration authorization CG configuration information; wherein, the CG configuration authorization information includes: CG SSB RSRP threshold, CG timing advance timer, CG timing advance verification configuration, and CG RSRP change threshold; The CG SSB RSRP threshold is the reference signal received power RSRP threshold for single-sideband SSB selection based on CG resources for small data transmission. The CG advance timer is used for timed synchronization of small data transmissions; The CG timed early verification configuration is used for configuring early TA verification based on RSRP; The CG RSRP change threshold is the RSRP threshold used for TA verification of small data transmission.

47. The apparatus according to claim 46, characterized in that, The first handover module is specifically used to reset the Media Access Control (MAC) and release the default MAC cell group configuration; Apply the aforementioned pause configuration information; When the CG configuration information is included in the pause configuration information, each DRB in the inactive small data transmission DRB list and the small data transmission SRB2 indication are identified as the DRB and SRB2 of the inactive small data transmission process; for each Radio Link Layer Control Protocol (RLC) bearer in the target terminal configuration, the RLC entity is rebuilt; for the recovered SRB2 and SRB1, the Packet Data Convergence Protocol (PDCP) entity is triggered to perform the Session Data Unit (SDU) discarding process; small data transmission CG resources are configured for the MAC entity, and the CG timing advance timer is started. The current access layer root key KgNB and the integrity protection key KRRCint of the radio resource control (RRC) signaling, the robust header compression (ROHC) state, the mapping rules between the stored quality of service (QoS) stream and data resource bearer (DRB), the cell radio network temporary identifier (C-RNTI) used in the source primary cell (PCell), the cell identifier and the physical cell identifier of the source PCell, the special cell SpCell common configuration in the synchronization reconfiguration message of the primary and secondary NR PSCells of the New Radio Interface, and all other configuration parameters except those in the synchronization reconfiguration message of the PCell, 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 in the EN-DC, and the serving cell common configuration (SIB) are stored in the inactive terminal access layer context information. Suspend all SRBs and DRBs except SRB0; Instruct all lower layers of the DRB to pause PDCP, which are located below the RRC layer; Switch to the inactive state and perform cell reselection.

48. The apparatus according to claim 33, characterized in that, The device further includes: The fourth receiving module is used to receive system messages broadcast by the target network device. The system messages include downlink transmission frequency information, initial downlink bandwidth portion (BWP), broadcast control channel (BCCH) configuration information, and paging channel (PCCH) configuration information.

49. The apparatus according to claim 48, characterized in that, 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 related to modifying the system message passing cycle; The PCCH configuration information includes a default paging period, the number and configuration of paging frames, the number of paging opportunities, and the first physical downlink control channel (PDCCH) listening opportunity. The default paging period is the default paging period broadcast in the system message. The number and configuration of paging frames are used to derive the total number of paging frames and the paging frame offset. The number of paging opportunities is used to indicate the number of paging opportunities in each paging frame. The paging opportunity is a set of PDCCH listening opportunities, consisting of multiple time slots for sending paging control information. The first PDCCH listening opportunity is the first PDCCH listening opportunity used to listen for paging opportunities in the paging frame.

50. The apparatus according to claim 45 or 49, characterized in that, The device further includes: The third determining module is used to determine the smaller value between the wireless paging period and the default paging period as the first time period for receiving paging messages when the target terminal is in an inactive state.

51. The apparatus according to claim 33, characterized in that, The device further includes: The fifth receiving module is used to receive a second release message sent by the target network device when the downlink small data packet transmission is completed, the second release message including indication information indicating a state switch; The second switching module is used to switch the current state to an inactive state or an idle state based on the indication information.

52. A data transmission device, characterized in that, Applied to a target network device, the apparatus includes: The fourth sending module is used to send a first release message to the terminal, the first release message including configuration authorization CG configuration information; The second sending module is configured to send a paging message to a target terminal currently in an inactive state according to a second time period. Upon receiving the paging message, the target terminal, for each paging record, if the Full Inactive Terminal I-RNTI in the paging record matches the Full Inactive Terminal I-RNTI stored in the target terminal, and the paging record includes an inactive downlink small data transmission indication, then sends a connection recovery request to the target network device based on the CG configuration information. The paging message includes a paging record list, and the paging record list includes at least one paging record. The sixth receiving module is used to receive a connection recovery request sent by the target terminal. The connection recovery request includes a connection recovery reason and an uplink small data packet. The connection recovery request is sent by the target terminal when it receives a paging message that includes its own designated paging record. The designated paging record includes an inactive downlink data transmission indication. The inactive downlink small data transmission indication is used to indicate that the paging message is used to trigger inactive downlink data transmission. The connection recovery reason in the connection recovery request is inactive downlink data transmission. The third sending module is used to generate feedback information for the uplink small data based on the connection recovery request, and to obtain the downlink small data packet, and send the downlink small data packet and the feedback information to the target terminal so that the target terminal receives the downlink small data packet.

53. The apparatus according to claim 52, characterized in that, The paging record includes the terminal identifier, access type, and inactive downlink data transmission indication of the paging terminal; The terminal identifier includes: a NAS layer identifier ID assigned to the terminal by the Non-Access Stratum (NAS) for core network paging, and a complete inactive terminal identifier for Radio Access Network (RAN) paging; the access type is used to indicate whether the paging message is initiated by a Protocol Data Unit (PDU) session that is not accessed by the 3GPP (3rd Generation Partnership Project).

54. The apparatus according to claim 53, characterized in that, The paging record also includes a non-contention access preamble that instructs the terminal to initiate non-contention random access.

55. The apparatus according to claim 52, characterized in that, The connection recovery request can be a first connection recovery request or a second connection recovery request; the first connection recovery request is sent by the target terminal when the SIB1 sent by the base station indicates that the connection recovery request uses the full recovery identifier, and the second connection recovery request is sent by the target terminal when the SIB1 sent by the base station does not indicate that the connection recovery request uses the full recovery identifier.

56. The apparatus according to claim 55, characterized in that, The first connection recovery request and the second connection recovery request include: a recovery identifier, a recovery integrity check code, and a recovery reason; Wherein, the recovery identifier of the first connection recovery request is the complete inactive terminal identifier stored by the target terminal, and the recovery identifier of the second connection recovery request is the truncated inactive terminal identifier stored by the target terminal; the recovery integrity check code is the authentication token used for terminal authentication at the base station; and the recovery reason is the inactive downlink small data transmission.

57. The apparatus according to claim 52, characterized in that, The device further includes: The first release message includes pause configuration information instructing the terminal to perform inactive state configuration, so that the target terminal switches its current state to inactive state based on the pause configuration information.

58. The apparatus according to claim 57, characterized in that, The pause configuration information includes: complete inactive terminal identifier, truncated inactive terminal identifier, wireless paging cycle, wireless notification area information, timer, next-hop chain count value, and inactive small data transmission configuration information.

59. The apparatus according to claim 58, characterized in that, The complete inactive terminal identifier and the truncated inactive terminal identifier are temporary wireless network identifier values ​​for inactive terminals, used by the target network side to find the anchor node before the terminal enters the inactive state and its stored access layer context information. The complete inactive terminal identifier and the truncated inactive terminal identifier have different sizes. The wireless paging cycle is the RAN paging cycle configured by the RAN-side node for the inactive terminal. The wireless notification area information includes a cell list and a wireless area configuration list, wherein the cell list is configured as a list of cells in the RAN area, and the wireless area configuration list includes the RAN area code or random access RA code of the RAN area; The timer is used to trigger the periodic notification region update RNAU process in the terminal; The next-hop chain count value is used to calculate the security key after the connection is restored; The inactive small data transmission configuration information includes: an inactive small data transmission data resource bearer (DRB) list and a small data transmission signaling radio bearer (SRB2) indication. The inactive small data transmission DRB list indicates the DRB identifier of the small data transmission configuration, and the small data transmission SRB2 indication is used to indicate whether the terminal has an SRB2 configured for small data transmission.

60. The apparatus according to claim 59, characterized in that, The inactive small data transmission configuration information also includes configuration authorization CG configuration information; wherein, the CG configuration authorization information includes: CG SSB RSRP threshold, CG timing advance timer, CG timing advance verification configuration, and CG RSRP change threshold; The CG SSB RSRP threshold is the reference signal received power RSRP threshold for single-sideband SSB selection based on CG resources for small data transmission. The CG advance timer is used for timed synchronization of small data transmissions; The CG timed early verification configuration is used for configuring early TA verification based on RSRP; The CG RSRP change threshold is the RSRP threshold used for TA verification of small data transmission.

61. The apparatus according to claim 52, characterized in that, The device further includes: The broadcast module is used to broadcast system messages, which include downlink transmission frequency information, initial downlink bandwidth portion (BWP), broadcast control channel (BCCH) configuration information, and paging channel (PCCH) configuration information.

62. The apparatus according to claim 61, characterized in that, 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 related to modifying the system message passing cycle; The PCCH configuration information includes a default paging period, the number and configuration of paging frames, the number of paging opportunities, and the first physical downlink control channel (PDCCH) listening opportunity. The default paging period is the default paging period broadcast in the system message. The number and configuration of paging frames are used to derive the total number of paging frames and the paging frame offset. The number of paging opportunities is used to indicate the number of paging opportunities in each paging frame. The paging opportunity is a set of PDCCH listening opportunities, consisting of multiple time slots for sending paging control information. The first PDCCH listening opportunity is the first PDCCH listening opportunity used to listen for paging opportunities in the paging frame.

63. The apparatus according to claim 62, characterized in that, The device further includes: The fourth determining module is used to determine the default paging period as the second time period for sending the paging message.

64. The apparatus according to claim 52, characterized in that, The device further includes: The fifth sending module is used to send a second release message to the target terminal when the downlink small data packet transmission is completed. The second release message includes indication information indicating a state switch, so that the target terminal switches its current state to an inactive state or an idle state based on the indication information.

65. A data transmission system, characterized in that, The system includes a target terminal and a target network device; The target terminal is used to execute the method according to any one of claims 1-19; The target network device is used to perform the method according to any one of claims 20-32.

66. A target terminal, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; A processor, when executing a program stored in memory, implements the steps of the method described in any one of claims 1-19.

67. A target network device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; A processor, when executing a program stored in memory, implements the steps of the method described in any one of claims 20-32.

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