CN115696644A - Method and related device for controlling transmission - Google Patents

Abstract

The embodiment of the application provides a method and a related device for controlling transmission, wherein the method is applied to a terminal in a non-Radio Resource Control (RRC) connection state and comprises the following steps: when a first preset condition is met, executing an RRC connection recovery process for updating an RNAU based on a notification area of a radio access network; the first preset condition comprises that the second timer is overtime and the first timer is not running; or the first preset condition comprises that the terminal receives a system information block SIB1 of a service cell, the service cell does not belong to a configured notification area based on a wireless access network, and a first timer is not operated; the first timer is started when the terminal initiates an RRC connection recovery process for packet data transmission SDT, and the second timer is started when the terminal receives an RRC release message comprising the duration of the second timer. The method and the device can avoid triggering of the RNAU in the SDT process, thereby avoiding influencing the transmission of packet data and unnecessary power consumption and signaling overhead.

Description

Method and related device for controlling transmission

Technical Field

The present application relates to the field of communications technologies, and in particular, to a method for controlling transmission and a related apparatus.

Background

In the communication system, a Radio Resource Control (RRC) layer may be included in a communication protocol stack of the terminal and the network device. Currently, there are three RRC states of a terminal, which are an RRC IDLE (RRC IDLE) state, an RRC INACTIVE (RRC INACTIVE) state, and an RRC CONNECTED (RRC CONNECTED) state. The terminal in the RRC INACTIVE state may transmit small packet data (small data) through the RRC connection recovery procedure and the network device, which may be referred to as performing small packet data transmission (SDT). When the terminal is in the RRC INACTIVE state, a Radio Access Network (RAN) may manage a RAN-based notification area (RNA), for example, the terminal may trigger an RNA update (RNA update, RNAU) and perform an RRC connection recovery process for the RNAU to notify the network device of the RNA in which the terminal is currently located.

When the terminal performs SDT, it may trigger execution of RNAU, and in this case, the terminal may stop the currently performed SDT and execute RNAU, thereby affecting transmission of small data, for example, increasing transmission delay, and subsequently initiating SDT again may also increase power consumption and signaling overhead.

Disclosure of Invention

The embodiment of the application discloses a method and a related device for controlling transmission, which can avoid influencing the transmission of packet data and unnecessary power consumption and signaling overhead.

In a first aspect, an embodiment of the present application provides a method for controlling transmission, where the method is applied to a terminal in a non-radio resource control RRC connected state, and the method includes: when a first preset condition is met, executing an RRC connection recovery process for updating an RNAU based on a notification area of a radio access network; wherein the first preset condition comprises that the second timer is overtime and the first timer is not running; or, the first preset condition includes that the terminal receives a system information block SIB1 of a first serving cell, the first serving cell does not belong to a configured radio access network-based notification area RNA, and the first timer is not running; the first timer is started when the terminal initiates an RRC connection recovery process for packet data transmission (SDT), and the second timer is started when the terminal receives an RRC release message comprising the duration of the second timer.

In some embodiments, the RRC connection recovery procedure for the RNAU includes sending an RRC request message with the recovery reason resumecuse information element IE being the rna-Update.

For example, the second timer is T380.

In the application, when the first timer runs (i.e. during the SDT process), no RNAU is executed, and when the SDT process is performed, the network device may acquire the RNA where the terminal is located, and not executing the RNAU may not affect the state of the network device acquiring the terminal, but may avoid affecting packet data transmitted in the SDT process, for example, avoid increasing transmission delay, and subsequently initiate the SDT again to increase unnecessary signaling overhead and power consumption.

In one possible implementation, the first timer is not running as the first timer is not started.

In some embodiments, the first timer is not on to characterize a requirement without an SDT.

In a possible implementation manner, before performing a radio resource control, RRC, connection recovery procedure for updating an RNAU based on a notification area of a radio access network when the first preset condition is satisfied, the method further includes: initiating an RRC connection recovery process for SDT, and starting the first timer; stopping the first timer when cell reselection occurs; the first preset condition comprises that the first timer does not operate and the service cell of the terminal does not belong to the configured RNA, the first timer does not operate and stops, and the service cell of the terminal is the service cell after the terminal is subjected to cell reselection.

In some embodiments, the RRC connection recovery procedure for SDT includes sending an RRC request message with the resumecuse IE mo-data.

In a possible implementation manner, the first preset condition further includes: the terminal is in an RRC inactive state; and/or the terminal can not perform the SDT process in the service cell.

In some embodiments, the terminal may not perform the SDT procedure in the serving cell, including: the terminal may not continue the previous SDT procedure in the serving cell. In some embodiments, the terminal may not perform the SDT procedure in the serving cell, including: the terminal may not initiate a new SDT procedure in the serving cell.

In one possible implementation, the method further includes: when the first timer runs, if an RRC reject message is received, stopping the first timer; if the second timer is not running, setting a first variable to a first value, the first variable being the first value indicating that there is a pending RNA update procedure.

In this application, if the first timer runs (i.e., during the SDT process), the second timer is overtime, and the terminal will not execute the RNAU, nor set the first variable to the first value, thereby avoiding affecting the current SDT process. When the SDT procedure abnormally ends (e.g., the first timer stops or times out), and the second timer does not run, the terminal may set the first variable to the first value so that the RNAU may be normally executed subsequently.

In one possible implementation, the method further includes: when the first timer runs, if an RRC reject message is received, stopping the first timer; and if the second timer is not operated, executing the Radio Resource Control (RRC) connection recovery process for the RNAU.

In the application, if the first timer runs (i.e. during the SDT process), the second timer is overtime, and the terminal cannot execute the RNAU, thereby avoiding affecting the current SDT process. When the SDT process is abnormally finished (such as the first timer stops or times out) and the second timer does not run, the terminal executes the RNAU again to ensure the normal execution of the RNAU.

In one possible implementation, the method further includes: when the first timer runs, if an RRC reject message is received, stopping the first timer; if the second timer does not run, starting a third timer, and if the third timer is overtime, if the first timer does not run, executing the RRC connection recovery process for the RNAU.

In one possible implementation, the duration of the third timer is the same as the duration of the second timer.

In one possible implementation, the duration of the third timer is different from the duration of the second timer.

In one possible implementation, the non-RRC connected state is an RRC inactive state; and after the terminal receives the RRC refusing message, the terminal is in the RRC non-activated state.

In the application, if the first timer runs (i.e. during the SDT process), the second timer is overtime, the terminal cannot execute the RNAU, and the third timer cannot be started, so that the current SDT process is prevented from being affected. When the SDT procedure ends abnormally (for example, the first timer stops or times out), and the second timer does not run, the terminal may start the third timer, and when the third timer times out and the first timer does not run, the radio resource control RRC connection recovery procedure for the RNAU is executed again, so as to ensure normal execution of the RNAU.

In one possible implementation, the method further includes: when the first timer is overtime, if the second timer is not running, setting a first variable to a first value, wherein the first variable is the first value and indicates that the pending RNA updating process exists.

In one possible implementation, the method further includes: and when the first timer is overtime, if the second timer is not operated, executing the Radio Resource Control (RRC) connection recovery process for the RNAU.

In one possible implementation, the method further includes: and when the first timer is overtime, if the second timer is not operated, starting a third timer, and when the third timer is overtime, if the first timer is not operated, executing the RRC connection recovery process for the RNAU.

In one possible implementation, the duration of the third timer is the same as the duration of the second timer.

In one possible implementation, the duration of the third timer is different from the duration of the second timer.

In one possible implementation, the non-radio resource control RRC connected state is an RRC inactive state; and after the first timer is overtime, the terminal is in the RRC non-activated state.

In one possible implementation, the method further includes: when the first timer runs, if cell reselection occurs, stopping the first timer; receiving SIB1 of a second service cell, wherein the second service cell is a service cell after the terminal is subjected to cell reselection; when receiving the SIB1 of the second serving cell, if the second serving cell belongs to the configured RNA and the second timer is not running, setting a first variable to a first value, where the first variable indicates that there is a pending RNA update procedure for the first value.

In one possible implementation, the method further includes: when the first timer runs, if cell reselection occurs, stopping the first timer; receiving SIB1 of a second serving cell, wherein the second serving cell is a serving cell after cell reselection of the terminal; and when the SIB1 of the second serving cell is received, if the second serving cell belongs to the configured RNA and the second timer is not running, executing the RRC connection recovery process for the RNAU.

In one possible implementation, the method further includes: when the first timer runs, if cell reselection occurs, stopping the first timer; receiving SIB1 of a second serving cell, wherein the second serving cell is a serving cell after cell reselection of the terminal; and when receiving the SIB1 of the second serving cell, if the second serving cell belongs to the configured RNA and the second timer does not run, starting a third timer, and if the third timer is overtime, if the first timer does not run, executing the RRC connection recovery procedure for the RNAU.

In one possible implementation, the duration of the third timer is the same as the duration of the second timer.

In one possible implementation, the duration of the third timer is different from the duration of the second timer.

In one possible implementation, the non-RRC connected state is an RRC inactive state; and after the terminal performs cell reselection, the terminal is in the RRC non-activated state.

In a possible implementation manner, after the setting the first variable to the first value, the method further includes: and if the access barring is alleviated and the non-access NAS layer does not request the RRC layer to perform RRC connection recovery, if the first variable is the first value, performing the RRC connection recovery process for the RNAU.

In one possible implementation, the non-radio resource control RRC connected state is an RRC inactive state.

In a second aspect, an embodiment of the present application provides another method for controlling transmission, which is applied to a terminal in a non-RRC connected state, and the method includes: when a first preset condition is met, setting a first variable as a first value, wherein the first variable indicates that an RNA updating process is to be determined for the first value, the first preset condition comprises that a first timer is not operated, and the first timer is started when the terminal receives an RRC release message comprising the duration of the first timer.

For example, the first timer is T380.

In a possible implementation manner, the first preset condition further includes that when a second timer runs, the terminal receives an RRC reject message; the second timer is started when the terminal initiates an RRC connection recovery process for SDT, and the second timer is stopped when the terminal receives the RRC reject message.

In a possible implementation manner, the first preset condition further includes that a second timer expires, and the second timer is started when the terminal initiates an RRC connection recovery procedure for SDT.

In one possible implementation, the non-RRC connected state is an RRC inactive state; and after the second timer is overtime, the terminal is in the RRC inactive state.

In a possible implementation manner, the first preset condition further includes that the terminal receives SIB1 of a first serving cell, and the first serving cell belongs to the configured RNA; before the setting the first variable to the first value when the first preset condition is met, the method further includes: when a second timer runs, if cell reselection occurs, stopping the second timer, and starting the second timer when the terminal initiates an RRC connection recovery process for SDT; and receiving the SIB1 of the first serving cell, wherein the first serving cell is a serving cell after the cell reselection of the terminal occurs.

In one possible implementation manner, after the setting the first variable to the first value, the method further includes: and if the access barring is alleviated and the non-access NAS layer does not request the RRC layer to perform RRC connection recovery, performing RRC connection recovery for the RNAU if the first variable is the first value.

In one possible implementation, the non-RRC connected state is an RRC inactive state.

In this application, if the second timer runs (i.e., during the SDT process), the first timer is overtime, and the terminal will not execute the RNAU, nor set the first variable to the first value, thereby avoiding affecting the current SDT process. When the SDT procedure abnormally ends (e.g., the second timer stops or times out), and the first timer does not run, the terminal may set the first variable to the first value so that the RNAU may be normally executed subsequently.

In a third aspect, an embodiment of the present application provides another method for controlling transmission, where the method is applied to a terminal in a non-RRC connected state, and the method includes: starting a first timer; initiating an RRC connection recovery procedure for SDT; in the RRC connection recovery process for the SDT, a bottom layer indicates first information to an upper layer, wherein the first information indicates that the RRC connection recovery process for the SDT is successful; stopping the first timer based on the first information.

In some embodiments, the terminal starts the first timer upon receiving the RRC release message including the first timer duration. For example, the first timer is T380.

In the application, the terminal may stop the first timer when performing the SDT procedure, so as to avoid triggering the RNAU by the first timer overtime. When the SDT is carried out, the network equipment can acquire the RNA of the terminal, and the state of the terminal acquired by the network equipment cannot be influenced without triggering the RNAU, and the influence on the packet data transmitted in the SDT process can be avoided.

In one possible implementation, the initiating the RRC connection recovery procedure for SDT includes: the terminal sends an RRC request message to network equipment, and the bottom layer of the terminal receives a first response message sent by the network equipment in response to the RRC request message; the bottom layer indicates first information to the upper layer, including: based on the first response message, the bottom layer indicates the first information to the upper layer.

In one possible implementation, the RRC connection recovery procedure for SDT includes: the terminal sends RRC request information to network equipment in the random access process; the bottom layer indicates first information to the upper layer, including: a Media Access Control (MAC) layer indicates first information to an RRC layer, wherein the first information indicates that contention resolution is successful; the stopping the first timer based on the first information includes: and the RRC layer receives the first information indicated by the MAC layer and stops the first timer.

In a possible implementation manner, the sending, by the terminal, an RRC request message to the network device includes: and the terminal sends the RRC request message to the network equipment in the random access process, and the first response message indicates that the competition resolving is successful.

For example, the first response message is a contention resolution message.

In one possible implementation, the RRC connection recovery procedure for SDT includes: the terminal sends an RRC request message to network equipment based on the preconfigured uplink resources; the first information indicates that the RRC request message was successfully transmitted.

In one possible implementation, the bottom layer indicates the first information to the upper layer, including: the Media Access Control (MAC) layer indicates the first information to the RRC layer; the stopping the first timer based on the first information includes: the RRC layer receives the first information indicated by the MAC layer and stops the first timer; or, the bottom layer indicates first information to an upper layer, including: the physical layer indicates the first information to the RRC layer; the stopping the first timer based on the first information includes: the RRC layer receives the first information indicated by the physical layer and stops the first timer; or, before the bottom layer indicates the first information to the upper layer, the method further includes: the physical layer indicates second information to the MAC layer, and the second information indicates that the RRC request message is successfully sent; the bottom layer indicates first information to the upper layer, including: the MAC layer receives the second information indicated by the physical layer and indicates first information to an RRC layer; the stopping the first timer based on the first information comprises: and the RRC layer receives the first information indicated by the MAC layer and stops the first timer.

In a possible implementation manner, the sending, by the terminal, an RRC request message to a network device includes: the terminal sends the RRC request message to the network equipment based on the preconfigured uplink resources, and the first response message indicates that the RRC request message is sent successfully.

In one possible implementation, the initiating the RRC connection recovery procedure for SDT includes: and initiating the RRC connection recovery process for the SDT and starting a second timer.

In one possible implementation, after stopping the first timer, the method further includes: when the second timer runs, if an RRC reject message is received, stopping the second timer; if the first timer is not running, setting a first variable to a first value, the first variable being the first value indicating that there is a pending RNA update procedure.

In this application, if the first timer is stopped during the SDT process, the terminal may set the first variable to the first value when the SDT process abnormally ends (for example, the second timer stops or times out), so that the RNAU may be continuously triggered subsequently, and normal execution of the RNAU is ensured.

In one possible implementation, after stopping the first timer, the method further includes: when the second timer runs, if an RRC reject message is received, stopping the second timer; and if the first timer is not operated, executing the Radio Resource Control (RRC) connection recovery process for the RNAU.

In this application, if the first timer is stopped during the SDT process, the terminal may execute the RNAU again when the SDT process is abnormally ended (e.g., the second timer is stopped or times out), so as to ensure normal execution of the RNAU.

In a possible implementation manner, after stopping the first timer, the method further includes: when the second timer runs, if an RRC reject message is received, stopping the second timer; and if the first timer does not run, starting a third timer, and if the third timer is overtime, and if the second timer does not run, executing the RRC connection recovery process for the RNAU.

In one possible implementation, the duration of the third timer is the same as the duration of the first timer.

In one possible implementation, the duration of the third timer is different from the duration of the first timer.

In one possible implementation, the non-radio resource control RRC connected state is an RRC inactive state; and after the terminal receives the RRC refusing message, the terminal is in the RRC non-activated state.

In this application, if the first timer is stopped during the SDT process, the terminal may start the third timer when the SDT process abnormally ends (for example, the second timer is stopped or is overtime), and execute the RNAU again when the third timer is overtime and the second timer is not running, so as to ensure normal execution of the RNAU.

In one possible implementation, the method further includes: when the second timer is overtime, if the first timer is not operated, setting a first variable as a first value, wherein the first variable is used as the first value to indicate that an RNA updating process to be determined exists.

In one possible implementation, the method further includes: and when the second timer is overtime, if the first timer does not run, executing the Radio Resource Control (RRC) connection recovery process for the RNAU.

In one possible implementation, the method further includes: and when the second timer is overtime, if the first timer is not operated, starting a third timer, and when the third timer is overtime, if the second timer is not operated, executing the RRC connection recovery process for the RNAU.

In one possible implementation, the duration of the third timer is the same as the duration of the first timer.

In one possible implementation, the duration of the third timer is different from the duration of the first timer.

In one possible implementation, the non-RRC connected state is an RRC inactive state; and after the first timer is overtime, the terminal is in the RRC non-activated state.

In one possible implementation, the method further includes: when the second timer runs, if cell reselection occurs, stopping the second timer; receiving an SIB1 of a first serving cell, wherein the first serving cell is a serving cell after cell reselection of the terminal; when receiving the SIB1 of the first serving cell, if the first serving cell belongs to the configured RNA and the first timer is not running, setting a first variable to a first value, where the first variable is the first value and indicates that there is a pending RNA update procedure.

In one possible implementation, the method further includes: when the second timer runs, if cell reselection occurs, stopping the second timer; receiving an SIB1 of a first serving cell, wherein the first serving cell is a serving cell after cell reselection of the terminal; when receiving the SIB1 of the first serving cell, if the first serving cell belongs to the configured RNA and the first timer is not running, performing the radio resource control RRC connection recovery procedure for the RNAU.

In one possible implementation, the method further includes: when the second timer runs, if cell reselection occurs, stopping the second timer; receiving an SIB1 of a first serving cell, wherein the first serving cell is a serving cell after cell reselection of the terminal; when SIB1 of the first service cell is received, if the first service cell belongs to the configured RNA and the first timer does not run, starting a third timer, and if the third timer is overtime, if the second timer does not run, executing an RRC connection recovery process for RNAU.

In one possible implementation, the duration of the third timer is the same as the duration of the second timer.

In one possible implementation, the duration of the third timer is different from the duration of the second timer.

In one possible implementation, the non-RRC connected state is an RRC inactive state; and after the terminal reselects the cell, the terminal is in the RRC non-activated state.

In a possible implementation manner, after the setting the first variable to the first value, the method further includes: and if the access barring is alleviated and the non-access NAS layer does not request the RRC layer to perform RRC connection recovery, performing RRC connection recovery for the RNAU if the first variable is the first value.

In one possible implementation, the non-RRC connected state is an RRC inactive state.

In a fourth aspect, an embodiment of the present application provides a terminal, including a transceiver, a processor, and a memory; the memory is configured to store a computer program code, where the computer program code includes computer instructions, and the processor invokes the computer instructions to cause the ue to execute the method for controlling transmission provided in any one of the implementations of the first aspect to the third aspect and the first aspect to the third aspect of the embodiments of the present application.

In a fifth aspect, an embodiment of the present application provides a communication apparatus, which may be a terminal or a chip in the terminal, and the communication apparatus includes a processing unit, where the processing unit is configured to execute the method for controlling transmission provided in any one implementation manner of the first aspect to the third aspect and the first aspect to the third aspect of the embodiment of the present application.

In a sixth aspect, the present application provides a computer storage medium storing a computer program, where the computer program includes program instructions, and the program instructions, when executed by a processor, are configured to execute the method for controlling transmission provided in any one implementation manner of the first aspect to the third aspect and the first aspect to the third aspect of the present application.

In a seventh aspect, an embodiment of the present application provides a computer program product, which, when run on a communication device, causes the communication device to execute the method for controlling transmission provided in any one implementation manner of the first aspect to the third aspect and the first aspect to the third aspect of the present application.

In an eighth aspect, an embodiment of the present application provides an electronic device, where the electronic device includes a device or a method for performing the method or the method described in any embodiment of the present application. The electronic device is, for example, a chip.

Drawings

The drawings used in the embodiments of the present application are described below.

Fig. 1 is a schematic architecture diagram of a communication system according to an embodiment of the present application;

fig. 2 is an architecture diagram of the communication protocol stack of the user plane of a new radio access NR;

fig. 3 is an architecture diagram of a communication protocol stack of the control plane of the NR;

FIG. 4 is a diagram illustrating a transition of a radio resource control RRC state of a user equipment UE;

fig. 5-10 are schematic diagrams illustrating a flow of some packet data transmission SDTs provided by an embodiment of the present application;

fig. 11 is a flowchart illustrating a method for controlling transmission according to an embodiment of the present application;

FIG. 12 is a timing diagram provided by an embodiment of the present application;

fig. 13-17 are schematic flow charts illustrating further methods for controlling transmissions according to embodiments of the present application;

FIG. 18 is a timing diagram of an embodiment of the present application;

fig. 19 is a flowchart illustrating another method for controlling transmission according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be described in detail and clearly with reference to the accompanying drawings. The terminology used in the description of the embodiments of the examples herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

The related devices and communication systems related to the present application will be first introduced.

In this embodiment, the network device may be a device for sending or receiving information, and in some embodiments, the network device is an access network device, such as but not limited to: a base station, a User Equipment (UE), a wireless Access Point (AP), a Transmission and Reception Point (TRP), a relay device, or other network devices having the function of the base station. The base station is a device deployed in a Radio Access Network (RAN) and configured to provide a wireless communication function. In different wireless access systems, the names of the base stations may be different, such as but not limited to: base Transceiver Stations (BTS) in global system for mobile communications (GSM) or Code Division Multiple Access (CDMA), node B (NB) in Wideband Code Division Multiple Access (WCDMA), evolved node B (eNodeB) in Long Term Evolution (LTE), fifth generation mobile communication technology (5 g), i.e., next generation base station (g node B, gbb) in new radio access (NR), or base station in other future network systems.

In this embodiment, a terminal may be a device having a wireless communication function, in some embodiments, the terminal is a UE, and in some embodiments, the terminal may also be referred to as a mobile station, an access terminal, a user agent, or the like. Illustratively, the terminal is in the form of a handheld device, a wearable device, a computing device, a portable device, or a vehicle-mounted device. Illustratively, the terminal is embodied as a device such as a cellular phone, a smart phone, smart glasses, a laptop, a personal digital assistant, or a cordless phone. The following embodiments take a terminal as an example for a UE.

Referring to fig. 1, fig. 1 is a schematic diagram of an architecture of a communication system according to an embodiment of the present disclosure. The communication system may be, but is not limited to, GSM, CDMA, wideband Code Division Multiple Access (WCDMA), time division code division multiple access (TD-SCDMA), universal Mobile Telecommunications System (UMTS), LTE, NR, or other future network systems.

As shown in fig. 1, the communication system may include a core network 110, a network device 120, and a UE130. Where core network 110 may be coupled to at least one network device 120, network device 120 may provide wireless communication services for at least one UE130, and UE130 may be coupled to at least one network device 120 via an air interface. The core network 110 is a key control node in the communication system, and is mainly responsible for signaling processing functions, such as but not limited to functions for implementing access control, mobility management, session management, and the like. In some embodiments, network device 120 is a base station. In NR, the core network 110 may be referred to as a 5G core (5G core, 5gc) 110, and the network device 120 may be referred to as a gNB120. In some embodiments, at least one base station may constitute a next generation radio access network (NG-RAN) node. The NG-RAN node may include at least one gNB120 connected to the 5GC110 through an NG interface, and at least one gNB120 in the NG-RAN node may be connected and communicate through an Xn-C interface. UE130 may connect to gNB120 over the Uu interface.

Core network 110 may send downlink data to UE130 through network device 120, and UE130 may also send uplink data to core network 110 through connected network device 120. It should be noted that the forms and numbers of the core network 110, the network device 120, and the UE130 shown in fig. 1 are only examples, and the embodiment of the present application does not limit this.

For convenience of understanding, in the embodiments of the present application, a communication system in which LTE and/or NR are mainly used, a network device is a base station, and one NG-RAN includes at least one base station is described as an example.

Next, a description will be given of a communication protocol stack of NR by way of example.

Referring to fig. 2, fig. 2 is a schematic diagram of an NR user plane protocol stack. The user plane protocol stack may include a Physical (PHY) layer, a Media Access Control (MAC) layer, a Radio Link Control (RLC) layer, a Packet Data Convergence Protocol (PDCP) layer, and a Service Data Adaptation Protocol (SDAP) layer.

Referring to fig. 3, fig. 3 is a schematic diagram of an NR control plane protocol stack. The control plane protocol stack may include a PHY layer, a MAC layer, an RLC layer, a PDCP layer, a Radio Resource Control (RRC) layer, a non-access stratum (NAS).

Compared with the user plane protocol stack of the LTE, the user plane protocol stack of the NR is additionally provided with the SDAP layer, but the architectures of other layers are consistent, the specific description is similar, the LTE is mature, and the description is omitted.

As shown in fig. 2 and 3, a lower layer of the PDCP layer includes an RLC layer. The PDCP layer may handle RRC messages on the control plane and may perform IP header compression to reduce the number of bits transmitted on the radio interface. The PDCP layer may also be responsible for ciphering in the control plane, integrity protection of transmitted data. At the receiving end, the PDCP layer performs corresponding decryption and decompression operations. One PDCP entity may be configured for each radio bearer. The RLC layer is responsible for segmentation/concatenation, retransmission control, duplicate detection, etc., and provides services to the PDCP layer, which may be configured with one RLC entity for each radio bearer. The MAC layer controls multiplexing of logical channels, retransmission of hybrid automatic repeat request, scheduling of uplink and downlink, and the like. The MAC layer provides services to the RLC layer in the form of logical channels. The PHY layer, which manages coding/decoding, modulation/demodulation, mapping of multiple antennas, and other types of physical layer functions, services the MAC layer in the form of transport channels.

As shown in fig. 2 and 3, the MAC layer may serve a higher layer (e.g., RLC layer) via a Logical Channel (LCH). The logical channels may be classified into a control channel for transmitting control information in a control plane and a traffic channel for transmitting user data in a user plane according to the type of transmission information. The control channel may include, but is not limited to, a Common Control Channel (CCCH) and a Dedicated Control Channel (DCCH). The traffic channel may include, but is not limited to, a Dedicated Traffic Channel (DTCH). The CCCH may be present all the time and may be used by UEs that do not have an RRC connection with the RAN node. The DCCH may be used for transmission of dedicated control information between the UE and the RAN node. The DTCH can be used to transfer user data between the UE and the RAN node. Generally, DCCH and DTCH do not exist all the time, but they can be used for communication between a UE and a base station after the base station connected to the UE restores a UE context (UE context). The UE context includes, but is not limited to, an identifier of a terminal, a Radio Bearer (RB) related configuration, a security related configuration of integrity protection and ciphering, a quality of service related configuration, and the like.

The RB may be a connection format set between the UE and the RAN node and may include the relevant configuration of physical channels, transport channels, and logical channels. The RB may be divided into a Signaling Radio Bearer (SRB) for transmitting control information in the control plane and a Data Radio Bearer (DRB) for transmitting user data in the user plane. A DRB may include an entity of a PDCP layer (PDCP entity), an entity of an RLC layer (RLC entity), and a logical channel.

As shown in fig. 3, the RRC layer may be used to transmit RRC messages between the UE and the base station. For example, but not limited to, an RRC resume request (RRCResumeRequest) in the NR may be used for the UE to request resumption of the already suspended RRC connection, thereby transmitting data with the base station. The RRC layer belongs to an Access Stratum (AS).

For the RRC layer, there are currently three RRC states of the UE, which are an RRC IDLE (RRC IDLE) state, an RRC INACTIVE (RRC INACTIVE) state, and an RRC CONNECTED (RRC CONNECTED) state. The operations performed by the UE in different RRC states are mostly different, and the three states and the transition procedure may specifically refer to the example in fig. 4 below.

AS shown in fig. 4, when the UE is in the RRC CONNECTED state, an RRC connection is established between the UE and the base station, in some embodiments, when the UE is in the RRC CONNECTED state, a connection between a user plane and a control plane of the UE may be established between the 5GC and the NG-RAN, the NG-RAN and the UE may reserve UE context of an AS layer, the NG-RAN may obtain a cell to which the UE belongs, the UE may send or receive unicast data, a network (e.g., the NG-RAN) may control mobility of the UE, and the UE may measure a channel with the base station and report a measurement result to the base station, and the base station may determine whether to switch the cell to which the UE belongs according to the measurement result. In other words, in the RRCCONNECTED state, the UE and the base station can not only normally transmit data, but also the base station can manage the UE. In some embodiments, a UE in an RRC CONNECTED state needs to keep synchronized with a base station according to a Timing Advance (TA) in order to send uplink data to the base station. If the UE in the RRC CONNECTED state does not obtain uplink synchronization, the UE may initiate Random Access (RA) to the base station. Wherein, when the Timing Advance Timer (TAT) of the UE keeps running, the UE keeps uplink synchronization. When the TAT of the UE is overtime, the uplink synchronization of the UE is invalid, and if the UE needs to send uplink data to the base station again, RA needs to be initiated, and a new TA is obtained through RA. In some embodiments, the base station may allocate a Configured Grant (CG) resource for the UE when the UE is in the RRC CONNECTED state. When the UE has a data transmission requirement, the CG resource may be used to transmit uplink data to the base station. In some embodiments, the base station may configure the CG resources for the UE through RRC messages, and the configured information may include time-frequency location and period. Compared with the dynamic scheduling of transmission resources, the mode of transmitting data through the CG resources can reduce signaling overhead and transmission delay.

When there is no uplink resource but there is uplink data to be sent to the base station, the UE in the RRC CONNECTED state may trigger a Buffer Status Reporting (BSR) to request the base station to schedule the uplink resource. The BSR may be used to indicate the amount of data currently pending for transmission in a data buffer (buffer) of the UE. The data amount may be different at different times, for example, the UE is a smart phone, and the user may send a message to other users through a social application installed on the UE, but types and numbers of messages sent by the user at different times may be different, sometimes the sent message may be only one text message, and sometimes the sent message may include multiple videos. The size of the BSR that the UE transmits to the base station at different times may also be different. The resource for the UE to send the BSR to the base station (BSR resource for short) may be dynamically scheduled by the base station to the UE.

When the UE is in an RRC IDLE state, no RRC connection is established between the UE and the base station. In some embodiments, when the UE is in an RRC IDLE state, the UE may perform selection of a Public Land Mobile Network (PLMN), receive system information broadcast by a base station, perform cell reselection (cell re-selection), initiate Paging (Paging) initiated by 5GC for downlink transmission, configure Discontinuous Reception (DRX) by the NAS layer for Paging of a core network, and the like.

The RRC INACTIVE state is a new RRC state in NR. In some embodiments, for a UE with infrequent data transmissions, the base station typically keeps the UE in the RRC INACTIVE state. In some embodiments, when the UE is in RRC INACTIVE state, the UE may perform PLMN selection, receive system information broadcast by the base station, perform cell reselection, initiate Paging by NG-RAN (Paging), manage RAN-based Notification Area (RNA) by NG-RAN, e.g., UE triggers RNA update (RNAU) to notify the base station of the RNA in which the UE is currently located, configure DRX for RAN Paging by NG-RAN, may establish a connection between the user plane and the control plane of the UE between 5GC and NG-RAN, may retain UE context of AS layer, and NG-RAN may obtain the RNA in which the UE is located. In some embodiments, the UE enters the RRCCONNECTED state after the UE establishes an RRC connection with the base station. If the UE in the RRC CONNECTED state has no data transmission requirement with the base station within a preset time period, the base station may instruct the UE to enter the RRC _ INACTIVE state. For example, the base station may send an RRC release with suspend indication (rrcreelease with suspend indication) message to the UE, and after the UE receives the rrcreelease with suspend indication message, the UE retains its context and enters an RRCINACTIVE state.

As shown in fig. 4, in some embodiments, when the UE is in an RRC IDLE state or an RRC INACTIVE state (which may be collectively referred to as a non-RRC connected state), if data transmission is required, an RRC connection establishment procedure or an RRC connection recovery procedure may be performed. For example, the UE in the RRC IDLE state may send an RRC setup request (RRCSetupRequest) message to the base station, then receive an RRC setup (rrcsetupmessage) sent by the base station, and after receiving the rrcsetupmessage, the UE may establish an RRC connection with the base station and enter an RRC CONNECTED state. For example, the UE in the RRC INACTIVE state may send an RRCResumeRequest message to the base station, then receive an RRC resume (RRCResume) message sent by the base station, and after receiving the RRCResume message, the UE may enter the RRC CONNECTED state. In other embodiments, when the UE is in the non-RRC connected state, the RRC connection establishment procedure or the RRC connection recovery procedure may also be performed in response to a paging message of the base station, for example, the core network may instruct the base station to send the paging message to the UE when there is data to transmit to the UE.

In some embodiments, the UE may enter the RRC INACTIVE state or the RRC IDLE state from the RRC CONNECTED state at the direction of the base station. In some embodiments, when the UE does not need to perform data subsequently, the base station may release the UE to make the UE enter the RRC INACTIVE state or the RRC IDLE state, for example, as shown below.

For example, the UE enters the RRC INACTIVE state from the RRC CONNECTED state at the direction of the base station. In detail, the base station may send a release message with a suspend indication, for example, an rrcreelease with suspend indication message, to the UE, so that the UE enters the RRC INACTIVE state. At this point, the RRC connection between the UE and the base station is suspended, but at least one RAN node retains the UE context for that UE.

Example two, the UE enters RRC IDLE state from RRC CONNECTED state at the direction of the base station. In detail, the base station may send a release message, e.g., an RRC release (rrcreelease) message, to the UE to cause the UE to enter an RRC IDLE state. At this time, the RRC connection between the UE and the base station is stopped, and the RAN node deletes the UE context of the UE.

In some embodiments, the UE may also enter the RRC IDLE state from the RRC INACTIVE state under the instruction of the base station, for example, after the UE in the RRC INACTIVE state sends an RRC connection recovery request, the base station may release the UE to make the UE enter the RRC IDLE state. It is to be appreciated that the UE enters the RRC CONNECTED state from the RRC INACTIVE state faster than from the RRC IDLE state.

In some embodiments, when the UE is in the RRC IDLE state or the RRC INACTIVE state, if data transmission is required, an RRC connection establishment procedure or an RRC connection recovery procedure may be performed to request to enter the RRC connected state for data transmission, where if the UE in the RRC IDLE state or the RRC INACTIVE state does not send resources of the RRC setup request message or the RRC staterequest message, the UE needs to initiate a Random Access (RA) procedure. Next, RA is exemplarily presented.

In some embodiments, the UE may obtain the RA configuration of the current cell from system information broadcast by the base station, for example, the configuration includes an available random access preamble (RA preamble) and an RA resource for sending the random access preamble, for example, the RA resource for sending the random access preamble is a time-frequency resource for sending the random access preamble, which may also be referred to as a random access occasion (RO) by the UE. In some embodiments, the RA may include 4-step random access (4-stepRA) and 2-step random access (2-stepRA). The base station may broadcast the RA configuration corresponding to the 4-step RA and the RA configuration corresponding to the 2-step RA in the system message, may broadcast only the RA configuration corresponding to the 4-step RA in the system message, and may broadcast only the RA configuration corresponding to the 2-step RA in the system message.

In some embodiments, the base station may broadcast the RA configuration for the 4-step RA and the RA configuration for the 2-step RA in a system message. When the UE is not configured with resources of non-contention random access (CFRA), the UE may determine to initiate a 4-step RA or a 2-step RA based on a relative size of a Reference Signal Receiving Power (RSRP) currently measured and a preset RSRP threshold. For example, the UE may initiate a 2-step RA when the currently measured RSRP is greater than or equal to a preset RSRP threshold. When the currently measured RSRP is less than the preset RSRP threshold, the UE may initiate a 4-step RA.

In the third step of 4-step RA, the message sent by the UE to the base station may be referred to as message 3, which is abbreviated as msg3. The message sent by the UE to the base station in the first step of the 2-step RA may be referred to as message a, msgA for short. In some embodiments, the msg3 or msgA described above may comprise RRC messages. The RRC messages may be different when the UE is in different RRC states and in different traffic scenarios. For example, when the UE presence data in the RRC INACTIVE state is sent to the base station, the msg3 sent by the UE to the base station may include an RRCResumeRequest message, so as to request to resume the suspended RRC connection and enter the RRC CONNECTED state to transmit data with the base station.

It can be understood that, in general, a UE in a non-RRC CONNECTED state has uplink data to transmit to a base station, or receives a Paging (Paging) message transmitted by the base station, where the Paging message is used by the base station to indicate that downlink data exists to transmit to the UE, and the UE needs to reestablish or recover an RRC connection and enter an RRC CONNECTED state, and then transmits data with the base station in the RRC CONNECTED state. However, the above method is more suitable for a case where the amount of data transmitted between the UE and the base station is large. If the transmitted data packet is small, the data packet can be called small packet data (small data), and signaling required in the process of switching the state of the UE is even larger than the small packet data, thereby causing unnecessary power consumption and signaling overhead of the UE. Therefore, it is necessary to transmit the packet data to the base station when the UE is in the non-RRC connected state, for example, when the UE in the RRC INACTIVE state has a transmission requirement for the uplink packet data, the uplink packet data may be transmitted to the base station.

In this embodiment of the application, the packet data may include, but is not limited to, a data packet whose data amount is smaller than a preset threshold (for example, the size of a transmission block indicated by the base station), a data packet whose data tag is packet data, a data packet whose data type belongs to the packet data, and the like. The data packet of the non-small packet data may be referred to as a large packet data, and may include, but is not limited to, a data packet whose data amount is greater than or equal to a preset threshold, a data packet whose data tag is a large packet data, a data packet whose data type belongs to a large packet data, and the like. The data tag and/or the data type may be negotiated by the UE and the network device. For example, the data tag may include a large packet of data and a small packet of data. For example, data of which the data type is a heartbeat packet is packet data, and data of which the data type is a file, video or audio is packet data. Illustratively, the packet data is an instant messaging message of an application program (APP) of the UE, a heartbeat packet of the APP or a push message of the APP, the packet data is periodic data of the wearable device, and the packet data is service data of an internet of things (IoT) device.

In some embodiments, the transmitting the packet data to the base station when the UE is in the non-RRC CONNECTED state may include transmitting a small data by the UE in an RA procedure, which may be referred to as RA-based Small Data Transmission (SDT), or RA-SDT for short, without entering an RRC CONNECTED state and then transmitting the small data. In some embodiments, RA may include 4-step RA and 2-step RA, SDT may also include 4-step RA based SDT (4-step SDDT) and 2-step RA based SDT (2-step SDT), examples of 4-step SDT processes may be found in FIGS. 5 and 6, examples of 2-step SDT processes may be found in FIGS. 7 and 8. The implementation of RA-SDT is similar to RA, for example, the UE may obtain the configuration of RA-SDT from system information broadcast by the base station, and the UE may determine to initiate 4-step SDT or 2-step SDT based on the relative size of the currently measured RSRP and the preset RSRP threshold.

In other embodiments, the transmitting, by the UE, the packet data to the base station when the UE is in the non-RRC CONNECTED state may further include transmitting, by the UE, the small data through a pre-allocated CG resource or a pre-configured uplink resource (PUR), without entering the RRC CONNECTED state and then transmitting the small data, where the transmission process may be referred to as CG-based SDT, or CG-SDT for short, and a specific example of the process may be referred to as fig. 9 and fig. 10.

In some embodiments, there are multiple different application scenarios for the SDT, and different implementations of SDTs, such as RA-SDT or CG-SDT, may be used depending on the application scenario. Specific examples are as follows:

example one: in the CG-SDT, the resource (e.g. CG resource or PUR) indicated by the CG-SDT configuration is issued by the base station to the UE through dedicated control signaling, so that the CG-SDT configuration is applicable to the UE in the cell covered by the base station, the CG-SDT configuration provided in one cell cannot be reused by the UE in another cell, and if the UE moves into the coverage of other network equipment, the resource indicated by the CG-SDT configuration cannot be reused, and based on such characteristics, the following scenarios may be applied: for IoT applications, UEs in the IoT realm may prefer CG-SDT because the mobility of the UE is limited and all connections are typically established to send data in the same cell, with little change to the cell.

Example two: configuration of RA-SDT configuration related RA configuration can be provided by system information sent by the base station, the UE can read and apply the configuration of system information broadcast whenever the UE reselects to a new cell, based on such characteristics can be applied to the following scenarios, for example: for applications such as instant messaging messages of smart phones, the mobility of the UE is strong, and the UE may move from the coverage of one base station to the coverage of another base station. If the UE moves from the coverage of the base station A to the coverage of the base station B and is in the coverage of the base station B, the resource indicated by CG-SDT configuration sent by the base station A before moving is adopted for SDT, data cannot be transmitted, and because the resource for sending the random access preamble in the RA-SDT is broadcasted by the base station in real time, the RA-SDT can be preferentially adopted for the UE with strong mobility.

Of course, whether the UE uses CG-SDT or RA-SDT may not be limited by the scenario, and it may be determined which way to perform SDT based on the implementation of the UE.

Illustratively, since the resource for performing CG-SDT is configured by the base station specifically for the UE, the success rate of CG-SDT performed by the UE is high. The random access resource of the RA-SDT is broadcasted by the network equipment, the UE which can receive the broadcast message can initiate the RA-SDT on the random access resource, a plurality of UEs can compete for the resource and possibly cause the situation of competition failure, therefore, the success rate of the RA-SDT is not high than that of the CG-SDT, and the CG-SDT is possibly more effective than the RA-SDT. In general, CG-SDT is preferentially selected by the UE, and the CG-SDT is also selected by the UE, and if the CG-SDT is not selected by the UE, RA-SDT can be selected by the UE. For example, whether a resource indicated by CG-SDT configuration exists in a coverage range of a normal uplink carrier (NUL) or an auxiliary uplink carrier (SUL) where the UE is currently located, if the resource indicated by CG-SDT configuration exists and an effective resource exists in the resources indicated by CG-SDT configuration, the UE may select CG-SDT, otherwise select RA-SDT.

It is understood that the base station may configure DRBs for carrying data for the UE first, and the UE may recover the context (including the DRBs) before transmitting the data. In some embodiments, the DRBs configured by the base station for the UE may include DRBs for carrying small packet data (abbreviated as SDT DRBs) and DRBs for carrying large packet data (abbreviated as non-SDT DRBs). The UE can initiate the SDT only when the small packet data carried by the SDT DRB arrives, and the UE cannot initiate the SDT if the large packet data carried by the non-SDT DRB arrives. When the UE initiates SDT, the UE context needs to be restored, which may include SDT DRB.

In some embodiments, the state of the SDT may be determined by the state of a first timer, which may be denoted as T3XX, where X is a non-negative integer less than 10, which may be referred to as an SDT failure detection timer (SDT failure detection timer), which may be a timer of the RRC layer.

In some embodiments, the first timer may be started when the UE initiates an RRC connection recovery procedure for SDT, in some embodiments, the UE initializes the RRC connection recovery procedure for SDT when the UE initiates the RRC connection recovery procedure for SDT, and in other embodiments, the first timer may be started when the UE sends an RRC request message to initiate the RRC connection recovery procedure for SDT to the base station when the UE initiates the RRC connection recovery procedure for SDT. In some embodiments, the conditions under which the first timer is on include: the RRC connection recovery procedure for SDT is initialized. In other embodiments, the conditions under which the first timer is turned on include: an RRC request message for initiating an RRC connection recovery procedure for SDT is transmitted. For example, the RRC request message is an RRC request message in msg3 or msgA that is sent by the UE to the base station based on RA-SDT, and for example, the RRC request message is an RRC request message that is sent by the UE to the base station based on CG-SDT.

In some embodiments, the UE may stop the first timer when receiving an RRC response message or when a cell reselection occurs, and in some embodiments, the condition for stopping the first timer may include receiving an RRC response message or when a cell reselection occurs, where the RRC response message is, for example, an rrcreesume message, an rrcreelease with suspension indication message, an RRC reject (rrcreect) message, or another RRC message with the same function but not standardized by the third generation partnership project (3 rd generation partnership project, GPP 3), and in case the UE receives the rrcreelease message, the rrcrease with suspension indication message, or another RRC message with the same function but not standardized by 3GPP, the UE may consider the SDT to be successful and stop the first timer. In case that the UE receives the RRCResume message, the RRCSetup message, or other RRC messages with the same function but not standardized by 3GPP, the UE may consider that the SDT is successful and stop the first timer, or the UE may consider that the SDT is successful and transfer to the RRCCONNECTED state, and continue to perform data transmission and stop the first timer. In case the UE receives the RRCReject message or other RRC message with the same function but not standardized by 3GPP, the UE may consider that the SDT failed this time, and stop the first timer.

In some embodiments, within the period from the time when the first timer is started to the time when the first timer times out, the UE does not receive any response message sent by the base station, for example, a contention resolution (contention resolution) message, an RRC response message, or another response message, and then the UE may consider that the SDT fails and automatically end the SDT. It can be understood that the first timer can avoid the situation that the base station does not respond to the UE for a long time after the UE sends the request message or data to the base station.

Next, the transmission procedure of the SDT is exemplarily described.

Turning to fig. 5, fig. 5 illustrates a flow diagram of a user-down 4-step SDT procedure. The process shown in FIG. 5 may include, but is not limited to, the following steps:

s111: and the UE sends random access preamble to the base station.

In some embodiments, the base station may send a broadcast message to the UE, where the broadcast message includes first resource configuration information, and the first resource configuration information is used to indicate a random access resource for sending a random access preamble. Optionally, the first resource configuration information may specifically indicate a first random access resource used for initiating normal random access, and optionally, the first resource configuration information may specifically indicate a second random access resource used for sending a random access preamble in an RA-SDT process. Wherein, the random access preamble may be generated by the UE according to a specific rule, but the base station can identify the random access preamble generated by the UE.

In some embodiments, the random access preamble that the UE is to send for RA-SDT may be different from the random access preamble that the UE is to initiate normal RA without RA-SDT. That is, the base station may utilize different random access preambles to distinguish the intention of the UE, such as the intention of the UE to do RA-SDT or to initiate RA.

In other embodiments, the random access preamble that the UE wants to send for RA-SDT may also be the same as the random access preamble that the UE wants to initiate normal RA without RA-SDT.

In some embodiments, if the first resource configuration information specifically indicates a first random access resource used for initiating normal random access and a second random access resource used for sending random access preamble in the RA-SDT process. The UE may send random access preamble on different random access resources based on different intents, so that the base station may distinguish the intention of the UE by using different resources for receiving random access preamble. For example, when the UE intends to initiate an RA, the random access preamble is sent on the first random access resource, and when the base station receives the random access preamble through the first random access resource, it may be determined that the UE intends to initiate an RA. And when the base station passes through the second random access resource, the UE can be determined to intend to carry out RA-SDT.

In other embodiments, the random access resource for the UE to perform RA-SDT to send random access preamble may also be the same as the random access resource for the UE to initiate normal RA without performing RA-SDT.

S112: in response to the random access preamble, the base station sends a Random Access Response (RAR) to the UE.

Specifically, after sending the random access preamble to the base station, the UE may monitor a Physical Downlink Control Channel (PDCCH) within the RAR time window to receive the RAR sent by the base station. If the UE does not receive the RAR sent by the base station within the RAR time window, the UE may determine that the RA fails this time. The RAR is configured to schedule Uplink (UL) resources for the UE, so that the UE can transmit msg3 (including the RRC request message in S113) on the resources scheduled by the RAR.

In some embodiments, the RAR may further include at least one of a temporary cell radio network temporary identifier (TC-RNTI) and a Timing Advance (TA). The TA is used for the UE to learn uplink synchronization.

S113: and the UE sends uplink packet data and an RRC request message to the base station on the resource allocated by the RAR.

In some embodiments, the RRC request message may carry intention information indicating an intention of the UE to send the RRC request message, such as the intention of the UE to do RA-SDT or to initiate RA. Exemplarily, if the random access preamble that the UE wants to initiate RA-SDT transmission is the same as the random access preamble that the UE initiates normal RA without performing RA-SDT, or the random access resource that the UE wants to initiate RA-SDT transmission is the same as the random access resource that the UE wants to initiate normal RA without performing RA-SDT transmission, the RRC request message that the UE wants to perform RA-SDT transmission may carry intention information, which is used to indicate the intention that the UE wants to initiate RA-SDT instead of initiating normal RA.

In other embodiments, the UE may transmit the BSR when transmitting msg3 to the base station, and the base station may acquire the intention of the UE through the BSR transmitted by the UE, such as the intention of the UE to perform RA-SDT or to initiate RA. Illustratively, the random access preamble to be sent by the UE for RA-SDT is the same as the random access preamble to be sent by the UE for initiating normal RA without RA-SDT, the random access resource to be sent by the UE for RA-SDT may also be the same as the random access resource to be sent by the UE for initiating normal RA without RA-SDT, if the UE is to perform RA-SDT, a BSR may be sent when msg3 is sent to the base station, the BSR is used to indicate the data volume of the packet data, and the intention that the base station can obtain the UE through the received BSR is to initiate RA-SDT instead of initiating normal RA.

In some embodiments, the RRC request messages in msg3 may be different for UEs in different RRC states and in different traffic scenarios. For example, the RRC request message sent by the UE in the RRC IDLE state (optionally, the UE may store UE context such as configuration information for obtaining a key used to encrypt the uplink packet data, or the UE may not store the context) may include an RRC connection request (RRCConnectionRequest) message, an RRC connection recovery request (RRCConnectionResumeRequest) message, an RRC data early transmission request (RRCEarlyDataRequest) message, an rrcresumererequest 1 message, an rrcsetrequest message, or other RRC messages having the same function but not standardized by 3 GPP. The RRC request message sent by the UE in the RRC INACTIVE state may be an RRCConnectionRequest message, an rrcconnectionresummerequest message, an RRCEarlyDataRequest message, an RRCResumeRequest1 message, an RRCSetupRequest message, or other RRC messages having the same function but not standardized by 3 GPP.

In some embodiments, the UE may transmit uplink packet data and an RRC request message to the base station to initiate an RRC connection recovery procedure for the 4-step SDT, and in some embodiments, the RRC request message to initiate the RRC connection recovery procedure for the 4-step SDT includes an Information Element (IE) of a recovery cause (resume _ cause), and the resume _ cause IE may be set to mo-data.

In some embodiments, the UE initiates the RRC connection recovery procedure for SDT and then sends an RRC request message to the base station based on 4-step SDT. In some embodiments, the UE starts the first timer when initiating the RRC connection recovery procedure for SDT, and in other embodiments, the UE starts the first timer when sending the uplink packet data and the RRC request message to the base station based on 4-step SDT.

In some embodiments, msg3 may include an identity of the UE, such as a unique identity of the UE at the core network. In some embodiments, msg3 may include information about a base station connected to the UE, such as an inactive temporal radio network temporal identifier (I-RNTI). In some embodiments, msg3 may include information for encryption and integrity protection.

In some embodiments, the uplink packet data may be transmitted on a DTCH, and the RRC message may be transmitted on a CCCH. The MAC layer may encapsulate the packet data and the RRC request message and transmit the encapsulated packet data and RRC request message to the base station through the PHY layer.

S114: and after receiving the RRC request message, the base station sends a content resolution message to the UE.

In some embodiments, after receiving the uplink packet data and the RRC request message, the base station may restore the UE context and send the received uplink packet data to the core network.

In some embodiments, the content resolution message is actually a contention resolution Identity medium access control element (content resolution Identity MAC control element, content resolution Identity MAC CE), which may indicate that the UE contention resolution is successful. In some embodiments, the UE may determine whether the content resolution Identity MAC CE is consistent with msg3 sent by S113, and if so, determine that the contention resolution corresponding to the current RA-SDT procedure is successful, or determine that the current RA-SDT procedure is successful.

S115: the base station sends an RRC response message to the UE.

In some embodiments, if the core network has downlink packet data to send to the UE, the core network may send the downlink packet data to the base station. Then, the base station may transmit the downlink packet data to the UE together when transmitting the RRC response message. Wherein, the downlink packet data can be transmitted on DTCH and multiplexed with RRC response message transmitted on DCCH in MAC layer.

In some embodiments, the UE may determine whether the uplink packet data is successfully transmitted according to the RRC response message, where specific examples are as follows:

the first example is as follows: the RRC response message sent by the base station is an RRC connection release (RRCConnectionRelease) message, an RRC connection recovery (rrcconnectionresponse) message, an RRC connection setup (RRCConnectionSetup) message, an RRCRelease message, an rrcreesume message, or an RRCSetup message, or other RRC messages having the same function but not standardized by 3 GPP. The UE may determine that the SDT transmission is successful this time and stop the first timer when receiving the RRC response message.

Example two: the RRC response message sent by the base station is an RRC connection reject (RRCConnectionReject) message, an RRCReject message, or other RRC messages having the same function but not standardized by 3 GPP. The UE may determine that the SDT transmission fails this time when receiving the RRC response message, and stop the first timer.

In some embodiments, the UE may remain in the current RRC state or enter into other RRC states according to the RRC response message, specific examples of which are as follows:

example one: if the core network does not have the requirement of further data transmission, the RRC response message sent by the base station is an RRC data early transfer complete (RRCEarlyDataComplete) message, an RRCConnectionRelease message, an rrcreelease with suspend configuration message, an rrcreelease message, or other RRC messages with the same function but not standardized by 3 GPP. When the UE receives the RRC response message, the UE may consider that the SDT transmission procedure is successful, and stop the first timer. And, the UE may remain in a current non-RRC connected state in response to the RRC response message. Optionally, the RRC response message (e.g., rrcreelease message) may include a next hop chain count (NCC) of the UE ciphered packet data when the UE initiates the SDT next time.

Example two: if the core network has a need for further data transmission, the core network may trigger an indication process of connection establishment, and the RRC response message sent by the base station is an RRCConnectionSetup message, an rrcconnectionsesume message, an RRCSetup message, an rrcreesume message, or another RRC message having the same function but not standardized by 3 GPP. When the UE receives the RRC response message, the UE may consider that the SDT transmission procedure is successful, and stop the first timer. And, the UE may enter an RRC CONNECTED state in response to the RRC response message.

In some embodiments, if the UE does not receive the RRC response message in S115, it is considered that the small packet data transmission in S113 fails, for example, if the first timer times out and the UE does not receive the RRC response message yet, it is considered that the small packet data transmission in S113 fails. If the UE receives the RRC response message in S115, it considers that the packet data transmission in S113 is successful. That is, the UE may determine whether the transmission of the small packet data in S113 is successful by using whether the RRC response message is received.

It should be noted that, whether the core network has a need to further transmit data does not include a need for the base station to send downlink packet data in S115.

Referring to fig. 6, fig. 6 illustrates a flow diagram of an under-control plane 4-step SDT procedure. The process shown in FIG. 6 may include, but is not limited to, the following steps:

s121: and the UE sends random access preamble to the base station.

S122: and responding to the random access preamble, and sending the RAR to the UE by the base station.

Specifically, S121-S122 are similar to S111-S112 of FIG. 5 and are not described in detail.

S123: and the UE sends an RRC request message carrying uplink packet data to the base station on the resource allocated by the RAR.

Specifically, S123 is similar to S113 of fig. 5, except that the uplink packet data is not transmitted together with msg3 after being encapsulated at the MAC layer, but is transmitted in msg3, and in some embodiments, the uplink packet data may be carried in msg3 and transmitted on the CCCH. For example, the uplink packet data may be carried in an IE (e.g., dedicated information NAS) related to the NAS layer included in the RRCEarlyDataRequest message, and transmitted on the CCCH.

S124: and after receiving the RRC request message, the base station sends a content resolution message to the UE.

Specifically, S124 is similar to S114 of fig. 5, except that the RRC request message received by the base station includes uplink packet data, and in some embodiments, the base station may send the uplink packet data to the core network through the msg3 carrying the uplink packet data. For example, the base station may transmit the uplink packet data to the core network by forwarding the NAS layer related IE included in the msg3.

S125: the base station sends an RRC response message to the UE.

Specifically, S125 is similar to S115 of fig. 5, and is not described again.

Fig. 5 and fig. 6 illustrate an example where the UE performs S111 and/or S121 when there is uplink packet data to be sent to the base station, that is, the UE actively initiates a transmission process of the packet data. However, in a specific implementation, there is also a case where the UE passively initiates a transmission process of the packet data under the instruction of the base station, for example, a terminal terminated (MT) EDT (MT-EDT for short) in LTE. The transmission process in this case is similar to the transmission process shown in fig. 5 and 6, with the following differences:

before S111, when the core network has downlink packet data to send to the UE, the core network may send a paging message to the base station. In some embodiments, the paging message may carry data amount information of downlink packet data. In some embodiments, the base station may send a paging message to the UE, and the UE determines to initiate 4-step SDT based on the relative size of the currently measured RSRP and the preset RSRP threshold, for example, the base station may trigger MT-EDT according to the paging message and send a paging message carrying an MT-EDT indication to the UE, so that the UE triggers MO-EDT for MT-EDT. The difference between the above process of actively initiating packet data transmission by the UE is that: in S113, the UE may send only an RRC message to the base station, and does not send uplink packet data, and optionally may also carry reason information for triggering MT-EDT. Accordingly, the base station may receive downlink packet data sent by the core network, and in S115, the base station may send an RRC response message and the downlink packet data to the UE.

Similarly, before S121, when the core network has downlink packet data to send to the UE, the core network may send a paging message to the base station. In some embodiments, the paging message may carry data amount information of downlink packet data. In some embodiments, the base station may send a paging message to the UE, and the UE determines to initiate 4-step SDT based on a relative size of a currently measured RSRP and a preset RSRP threshold, where different from the UE actively initiating a transmission process of the cell data: in S123, the RRC message sent by the UE to the base station may not carry uplink packet data, and optionally, may also carry reason information for triggering MT-EDT. Accordingly, the base station may receive downlink packet data sent by the core network. In S125, the RRC response message sent by the base station to the UE may carry downlink packet data.

Referring to fig. 7, fig. 7 illustrates a flow diagram of a user-level 2-step SDT procedure. The process shown in FIG. 7 may include, but is not limited to, the following steps:

s211: and the UE sends random access preamble, RRC request message and uplink packet data to the base station.

In some embodiments, the transmission resource of the UE performing S211 may be obtained through information broadcast by the base station, for example, the UE may transmit random access preamble using RA resource broadcast by the base station, and the UE may transmit RRC request message using PUSCH resource broadcast by the base station.

In some embodiments, the base station may distinguish an intention of the UE by using different random access preambles, in other embodiments, the base station may distinguish an intention of the UE by using different resources for receiving the random access preambles, in other embodiments, the base station may obtain the intention of the UE by using the BSR sent by the UE, and in other embodiments, the RRC request message may carry intention information, where the intention information is used to indicate an intention of the UE for sending the RRC request message, for example, the intention of the UE is to perform RA-SDT or to initiate RA, which may be specifically referred to the examples of S111 and S113 in fig. 5, and is not described again.

In some embodiments, the UE is in different RRC states and in different service scenarios, the RRC request message in msgA may be different, which may specifically refer to the example of the RRC request message in msg3 in fig. 5, and is not described again.

In some embodiments, the RRC request message and the uplink packet data may be carried in a Physical Uplink Shared Channel (PUSCH) payload. The uplink packet data may be transmitted on a DTCH, and the RRC message may be transmitted on a CCCH. The MAC layer may encapsulate the packet data and the RRC request message and transmit the encapsulated packet data and RRC request message to the base station through the PHY layer.

In some embodiments, the UE may send the uplink packet data and the RRC request message to the base station to initiate the RRC connection recovery procedure for the 2-step SDT, and in some embodiments, the resumecuse IE may be set to mo-data in the RRC request message to initiate the RRC connection recovery procedure for the 2-step SDT.

In some embodiments, the UE initiates the RRC connection recovery procedure for SDT and then sends an RRC request message to the base station based on 2-step SDT. In some embodiments, the UE starts the first timer when initiating the RRC connection recovery procedure for SDT, and in other embodiments, the UE starts the first timer when sending the uplink packet data and the RRC request message to the base station based on 2-step SDT.

The description of the RRC request message and the uplink packet data may refer to the description of the RRC request message and the uplink packet data in S113 of fig. 5, which is not repeated herein.

S212: and after receiving the RRC request message, the base station sends a message B to the UE.

In some embodiments, after receiving the uplink packet data and the RRC request message, the base station may restore the UE context and send the received uplink packet data to the core network.

In some embodiments, the message sent by the base station to the UE in the second step of the 2-step RA may be referred to as message B (msgB). For example, msgB includes a successful RAR (success RAR) or a fallback RAR (fallback RAR).

In some embodiments, the msgB includes a success rar, and the success rar includes a content resolution field, for example, content resolution MAC CE includes content, and the UE determines that the contention resolution corresponding to the current RA-SDT procedure is successful or determines that the current RA-SDT procedure is successful when receiving the success rar. Optionally, the content resolution field in the success rar may indicate that the contention resolution of the UE is successful, and optionally, the UE may determine whether the content resolution field in the success rar is consistent with the msgA sent by S211, and if so, determine that the contention resolution corresponding to the current RA-SDT procedure is successful, or determine that the current RA-SDT procedure is successful. In other embodiments, the msgB includes a fallback rar, and the UE sends msg3 and uplink packet data to the base station again after receiving the fallback rar.

S213: the base station sends an RRC response message to the UE.

In some embodiments, if the core network has downlink packet data to send to the UE, the core network may send the downlink packet data to the base station. Then, the base station may transmit the downlink packet data to the UE together when transmitting the RRC response message.

The description of the RRC response message may refer to the description of the RRC response message in S115 of fig. 5, and is not repeated.

Referring to fig. 8, fig. 8 illustrates a flow diagram of an under-control plane 2-step SDT procedure. The process shown in FIG. 8 may include, but is not limited to, the following steps:

s221: and the UE sends random access preamble and RRC request message carrying uplink packet data to the base station.

Specifically, S221 is similar to S211 of fig. 7, except that the uplink packet data is not transmitted together with the RRC request message in msgA, but is transmitted in the RRC request message in msgA, and in some embodiments, the RRC request message carrying the uplink packet data may be carried in a Physical Uplink Shared Channel (PUSCH) payload and may be transmitted on CCCH.

S222: and after receiving the RRC request message, the base station sends msgB to the UE.

Specifically, S222 is similar to S212 of fig. 7, except that the RRC request message received by the base station includes uplink packet data, and in some embodiments, the base station may send the uplink packet data to the core network through the RRC request message carrying the uplink packet data. For example, the base station may send the uplink packet data to the core network by forwarding an RRCResumeRequest message carrying the uplink packet data.

S223: the base station sends an RRC response message to the UE.

Specifically, S223 is similar to S213 of fig. 7, and is not described again.

Fig. 7 and fig. 8 are described by taking an example that the UE performs S211 and/or S221 when there is uplink packet data to be sent to the base station, that is, the UE actively initiates a transmission process of packet data. However, in a specific implementation, there is also a case where the UE passively initiates a transmission process of the packet data under the instruction of the base station. The transmission process in this case is similar to the transmission process shown in fig. 7 and 8, with the following differences:

before S211, when the core network has downlink packet data to send to the UE, the core network may send a paging message to the base station. In some embodiments, the paging message may carry data amount information of downlink packet data. In some embodiments, the base station may send a paging message to the UE, and the UE determines to initiate 2-step SDT based on the relative size of the currently measured RSRP and a preset RSRP threshold, for example, the base station may trigger MT-EDT according to the paging message and send the paging message carrying the MT-EDT indication to the UE, so that the UE triggers MO-EDT for MT-EDT. The difference between the above process of actively initiating packet data transmission by the UE is that: in S211, the UE may only send random access preamble and RRC request message to the base station, and does not send uplink packet data, and optionally, may also carry reason information for triggering MT-EDT. Accordingly, the base station may receive downlink packet data transmitted by the core network, and the base station may transmit an RRC response message and the downlink packet data to the UE in S213.

Similarly, before S221, when the core network has downlink packet data to send to the UE, the core network may send a paging message to the base station. In some embodiments, the paging message may carry data volume information of downlink packet data. In some embodiments, the base station may send a paging message to the UE, and the UE determines to initiate 2-step SDT based on a relative size of a currently measured RSRP and a preset RSRP threshold, where different from the UE actively initiating a transmission process of the cell data: in S221, the RRC message sent by the UE to the base station may not carry uplink packet data, and optionally, may also carry reason information for triggering MT-EDT. Accordingly, the base station may receive downlink packet data sent by the core network. In S223, the RRC response message sent by the base station to the UE may carry downlink packet data.

Without being limited to the illustrated example, in other embodiments, the base station may also transmit the msgB and the RRC response message to the UE together.

In some embodiments, after the UE initiates RA-SDT, it cannot complete transmission of small data by sending msg3 or msgA once, and the UE may complete transmission of subsequent small data by subsequent transmission (subsequent transmission), where the subsequent transmission may be performed after the UE receives the context resolution and before the base station sends an RRC response message to the UE, for example, between S114 and S115 in fig. 5, and between S212 and S213 in fig. 7. Specific examples are as follows:

example one: the RA-SDT currently initiated by the UE is used for transmitting a small data (such as an instant messaging message), when the UE initiates a 4-step SDT, the UL grant indicated by the base station in the RAR is smaller than the sum of resources for transmitting the small data and the RRC request message, or when the UE initiates a 2-step SDT, the transmission resource acquired by the UE from the broadcast message is smaller than the sum of the resources for transmitting the random access preamble, the small data and the RRC request message. In this case, the UE may first transmit partial data of the small data through msg3 or msgA, and then transmit the remaining data of the small data through a subsequent transmission, for example, the base station may dynamically schedule uplink resources for the UE to perform the subsequent transmission after transmitting the content resolution to the UE.

Example two: the RA-SDT currently initiated by the UE is used for transmitting a plurality of small data, after the small data arrives, the UE can initiate 4-step SDT or 2-step SDT, and transmit the small data through msg3 or msgA, but in the SDT process, the UE acquires new small data, and then the UE can transmit the new small data through subsequent transmission, for example, after a base station sends a containment resolution to the UE, the base station can dynamically schedule uplink resources for the UE to perform subsequent transmission.

Referring to fig. 9, fig. 9 illustrates a flow diagram of a CG-SDT procedure under a user plane. The process shown in FIG. 9 may include, but is not limited to, the following steps:

s311: and the UE sends an RRC request message and uplink packet data to the base station on the pre-configured resources.

Illustratively, the pre-configured resource is a configured resource Type one (CG Type 1) or a PUR. The CG Type 1 may be an uplink resource directly configured by the RRC layer, and may include, but is not limited to, a time-frequency resource location and a resource period of the uplink resource.

In some embodiments, when both the base station and the UE support CG-SDT and the UE satisfies the condition to use CG-SDT, the UE may perform S311 without performing RA. The conditions for using CG-SDT include, for example: the UE is in a non-RRC connection state, has the transmission requirement of uplink packet data, has pre-configured resources, meets the RSRP condition and has an effective TA.

In some embodiments, the UE determining the conditions for using CG-SDT includes at least one of:

the first condition is as follows: the TAT runs, that is, the TA of the UE is valid, and the UE and the base station are in an uplink synchronization state, which may indicate that the CG-SDT is valid, otherwise, it is invalid.

And a second condition: on the premise that the TAT operates, the current RSRP of the UE is greater than a preset first RSRP threshold (RSRP 1 for short), which may indicate that the CG-SDT is valid. Optionally, the RSRP1 may be an RSRP at which the UE may initiate SDT transmission. That is, the current RSRP of the UE is greater than the preset RSRP1, which indicates that the UE is closer to the base station and the channel quality is better, and if CG-SDT is performed, the success rate is higher and the CG-SDT is effective. The current RSRP of the UE is smaller than or equal to the preset RSRP1, which means that the UE is far away from the base station and has poor channel quality, and if CG-SDT is carried out, the success rate is low. The RSRP1 can be configured for CG-SDT and RA-SDT by the base station.

And (3) carrying out a third condition: within the preset time period in which the TA is valid last time, the RSRP increase or decrease of the UE is less than or equal to the preset second RSRP threshold (abbreviated as RSRP 2), which may indicate that the CG-SDT is valid. That is, whether the UE moves or not may be determined according to the increase or decrease of the RSRP of the UE, if the increase or decrease of the RSRP is greater than or equal to RSRP 2, it indicates that the UE moves or moves a longer distance in the period in which the TA is valid last time, and if the CG-SDT is performed, the success rate is lower, and the CG-SDT is invalid. If the increase or decrease of the RSRP is smaller than the RSRP 2, the UE does not move or the moving distance is smaller in the period of time for which the TA is valid last time, and if CG-SDT is performed, the success rate is higher and the CG-SDT is valid.

And a fourth condition: if the base station configures CG-SDT on SUL and/or NUL, the UE needs to compare the current RSRP with a third RSRP threshold (RSRP 3 for short) preset by the base station, so as to determine whether the CG-SDT configured on SUL is valid or the CG-SDT configured on NUL is valid. Optionally, assuming that CG-SDT is configured on both SUL and NUL, the UE compares the current RSRP with RSRP3, selects CG-SDT on SUL if the current RSRP is less than RSRP3, and selects CG-SDT on NUL if the current RSRP is greater than or equal to RSRP 3. That is to say, under the condition that the base station configures CG-SDT on both SUL and NUL, if the current RSRP of the UE is less than RSRP3, it indicates that the UE is far away from the base station, and the CG-SDT configured on SUL should be adopted, that is, the CG-SDT on SUL is valid, and the CG-SDT on NUL is invalid. And if the current RSRP of the UE is greater than or equal to the RSRP3, the UE is close to the base station, and the CG-SDT configured on the NUL is adopted, namely the CG-SDT on the NUL is valid and the CG-SDT on the SUL is invalid. Optionally, assuming that the base station configures CG-SDT only on the SUL, the UE compares the current RSRP with RSRP3, selects CG-SDT on the SUL if the current RSRP is less than RSRP3, where the CG-SDT is valid, cannot use CG-SDT if the current RSRP is greater than or equal to RSRP3, that is, the CG-SDT on the SUL is invalid, that is, the base station configures CG-SDT on the SUL, and when the UE is farther from the base station, the CG-SDT on the SUL may be used, otherwise, the CG-SDT on the SUL is invalid. Alternatively, assuming that the base station configures CG-SDT only on NUL, the UE compares the current RSRP with RSRP3, and cannot use CGSDT if the current RSRP is less than RSRP3, and selects CGSDT on NUL if the current RSRP is greater than or equal to RSRP3, that is, CG-SDT on NUL is valid, that is, the base station configures CG-SDT on NUL, and may use CG-SDT on NUL if the UE is closer to the base station, otherwise CG-SDT on NUL is invalid.

And a fifth condition: the UE is in the range covered by the base station, and the base station configures CG resources for CG-SDT for the UE.

In some embodiments, prior to S311, the UE may also request configuration of pre-configured resources for initiating CG-SDT from the base station. For example, the UE transmits a CG-SDT resource request message to the base station in RRCCONNECTED state. The CG-SDT resource request message is used for requesting the base station to carry out CG-SDT configuration. For example, in LTE, the UE sends a PUR configuration information (purconfiguration request) message to the base station.

Alternatively, the UE may send the CG-SDT resource request message to the base station at any time in the RRCCONNECTED state. Optionally, the UE may determine that there may be packet data in the future in the RRCCONNECTED state, and may send a CG-SDT resource request message to the base station. Optionally, the UE is in an RRCCONNECTED state, the UE does not have a data transmission requirement with the base station within a preset time period, the UE determines that the UE may be about to enter a non-RRC connected state, and in order to transmit the packet data in the non-RRC connected state, the UE may send a CG-SDT resource request message to the base station.

In some embodiments, after receiving the request configuration information (e.g., a CG-SDT resource request message or a purconfiguration request message), when the base station indicates that the UE switches from the RRC CONNECTED state to the non-RRC CONNECTED state, the RRC response message sent by the base station to the UE may carry detailed CG-SDT configuration information. For example, when the base station indicates the UE to switch from the RRC CONNECTED state to the RRC INACTIVE state, the RRC response message is an rrcreelease message, and the rrcreelease message may carry detailed configuration information of the CG resource. For example, when the base station indicates the UE to switch from the RRC CONNECTED state to the RRC IDLE state, the RRC response message is an rrcreelease message, and the rrcreelease message may carry detailed configuration information of the PUR.

Without being limited to the above-mentioned example, in other embodiments, after the CG-SDT is configured for the UE by the base station, an RRC response message carrying the release indication information may be sent to the UE to release the configured CG-SDT. For example, the rrcreelease message may carry release indication information of the CG resource. For example, the RRCConnectionRelease message may carry release indication information of the PUR.

In other embodiments, the UE may not send the CG-SDT resource request message to the network device, and the network device may directly configure the CG-SDT resource for the UE, for example, the network device may configure the CG-SDT resource for the UE with reference to the UE's historical communication service condition.

In some embodiments, the UE may send the uplink packet data and the RRC request message to the base station to initiate the RRC connection recovery procedure for CG-SDT, and in some embodiments, in the RRC request message to initiate the RRC connection recovery procedure for CG-SDT, the resumecuse IE may be set to mo-data.

In some embodiments, the UE initiates the RRC connection recovery procedure for SDT and then sends an RRC request message to the base station based on CG-SDT. In some embodiments, the UE starts the first timer when initiating the RRC connection recovery procedure for SDT, and in other embodiments, the UE starts the first timer when sending the uplink packet data and the RRC request message to the base station based on CG-SDT.

Not limited to the foregoing example, in other embodiments, the UE may send only the packet data during performing CG-SDT, for example, for a resource indicated by the CG-SDT configuration is a specific resource configured by the network device to the UE, and is not a shared resource, the UE may send only the packet data during performing CG-SDT on the resource indicated by the CG-SDT configuration. Thus, the network device can identify the UE sending the packet data according to the resource receiving the packet data. For another example, if the resource indicated by the CG-SDT configuration is a shared resource configured by the network device to multiple UEs, the UE may send packet data and an RRC request message on the resource indicated by the CG-SDT configuration during the SDT process, so that the network device may identify the UE by using the RRC message.

The description of the RRC request message and the uplink packet data may refer to the description of the RRC request message and the uplink packet data in S113 of fig. 5, and is not repeated.

S312: and the base station sends a feedback response message to the UE.

In some embodiments, the base station sends a feedback response message to the UE in response to the RRC request message sent by the UE. In some embodiments, the feedback response message is used to indicate that the transmission of the RRC request message is successful, in some embodiments, the feedback response message is used to indicate that the transmission of the RRC request message and the uplink packet data transmitted together with the RRC request message is successful, and in some embodiments, the feedback response message is used to indicate that the transmission of the uplink packet data is successful.

In some embodiments, the feedback response message is a Layer one acknowledgement message (Layer 1acknowledgement, layer 1 ACK), i.e., a physical Layer ACK.

In some embodiments, the feedback response message is Downlink Feedback Information (DFI), i.e., CG-DFI.

In some embodiments, the feedback response message is a MAC CE of the MAC layer.

In some embodiments, the feedback response message is an RRC message of the RRC layer.

S313: the base station transmits an RRC response message to the UE.

In some embodiments, if the core network has downlink packet data to send to the UE, the core network may send the downlink packet data to the base station. Then, the base station may transmit the downlink packet data to the UE together when transmitting the RRC response message.

For the description of the RRC response message, reference may be made to the description of the RRC response message in S115 in fig. 5, which is not described again.

In some embodiments, the RRC response message may include CG-SDT configuration, for example, the CG-SDT configuration in S311 is used for the UE to transmit the packet data in S311, and the CG-SDT configuration indicated by the RRC response message in S313 is used for the UE to transmit the packet data next time.

In some embodiments, when the feedback response message in S312 is an RRC message of the RRC layer, the feedback response message in S312 and the RRC response message in S313 may be the same message, that is, the feedback response message may be the RRC response message, that is, S312 and S313 are the same step.

Referring to fig. 10, fig. 10 illustrates a flow diagram of an under-control CG-SDT process. The process shown in FIG. 10 may include, but is not limited to, the following steps:

s321: and the UE sends an RRC request message carrying uplink packet data to the base station on the pre-configured resource.

Specifically, S321 is similar to S311 of fig. 9, except that the uplink packet data is not sent together with the RRC request message, but is sent in the RRC request message.

S322: and the base station sends a feedback response message to the UE.

S323: the base station sends an RRC response message to the UE.

Specifically, S322-S323 are similar to S312-S313 of fig. 9 and will not be described again.

Fig. 9 and fig. 10 illustrate an example where the UE performs S311 and/or S321 when there is uplink packet data to be sent to the base station, that is, the UE actively initiates a transmission process of the packet data. However, in a specific implementation, there is also a case where the UE passively initiates a transmission process of the packet data under the instruction of the base station. The transmission process in this case is similar to the transmission process shown in fig. 9 and 10, with the following differences:

before S311, when the core network has downlink packet data to send to the UE, the core network may send a paging message to the base station. In some embodiments, the paging message may carry data volume information of downlink packet data. In some embodiments, the base station may send a paging message to the UE to cause the UE to initiate CG-SDT. The transmission process of the packet data actively initiated by the UE is different from that of the packet data actively initiated by the UE: in S311, the UE may only send the RRC request message to the base station, and does not send the uplink packet data, and optionally, may also carry reason information for triggering the MT-EDT. Accordingly, the base station may receive downlink packet data sent by the core network, and in S313, the base station may send an RRC response message and the downlink packet data to the UE.

Similarly, before S321, when the core network has downlink packet data to send to the UE, the core network may send a paging message to the base station. In some embodiments, the paging message may carry data volume information of downlink packet data. In some embodiments, the base station may send a paging message to the UE to cause the UE to initiate CG-SDT. The difference between the above process of actively initiating packet data transmission by the UE is that: in S321, the RRC message sent by the UE to the base station may not carry uplink packet data, and optionally, may also carry reason information for triggering MT-EDT. Accordingly, the base station may receive downlink packet data sent by the core network. In S323, the RRC response message sent by the base station to the UE may carry downlink packet data.

It is understood that the UE in RRC INACTIVE state is managed by NG-RAN, and the NG-RAN can obtain the RNA of the UE.

In some embodiments, the UE in RRC INACTIVE state may be configured with one RNA by the last serving base station, wherein one RNA may cover one or more cells, and the one RNA may be included in the core network registration area. In some embodiments, an Xn connection exists between base stations within the same RNA.

In some embodiments, the base station may configure related information of the RNA, such as a cell list or a RAN area (RAN area) list, for the UE through a RAN notification area information (RAN-notificationareinfo) IE in an RRC response message (e.g., rrcreelease message) sent to the UE.

The following exemplifies the case of two configuration RNAs:

the first condition is as follows: the base station configures the UE with a cell list, which in some embodiments is explicitly indicated to the UE by the base station, wherein the cell list includes one or more cells that constitute the RNA configured for the UE by the base station.

Case two: the base station configures a RAN area list for the UE, and in some embodiments, one or more RAN areas included in the RAN area list constitute RNAs configured by the base station for the UE. In some embodiments, the base station configures a RAN area Identification (ID) for the UE. Wherein each RAN area is a subset of a core network (core network) tracking area (CN tracking area) or equal to one CN tracking area. Each RAN area is identified by a RAN area ID, and each RAN area includes a Tracking Area Code (TAC) that is the tracking area to which the RAN area belongs. In some embodiments, each RAN area may include a RAN area code (RAN area code) that may be used to identify an area of the RAN area within a tracking area. In some embodiments, each cell and corresponding base station may broadcast one or more RAN area IDs in system information.

It is understood that the UE in RRC INACTIVE state may trigger an RNA update (rnapdate, RNAU), and optionally, the UE may trigger RNAU after configuring the RNA to inform the network device of the current RNA state of the terminal, for example, whether the RNA in which the terminal is currently located is within the RNA configured by the base station for the UE, the cell in which the UE is currently located, and other mobility-related states of the UE.

Two cases of triggering RNAU are exemplified next:

the first condition is as follows: the UE may trigger the RNAU periodically, which may be controlled by a second timer, e.g. a T380 specified for 38.321 in the 3GPP protocol, the T380 timeout being used to trigger the RNAU. In some embodiments, the base station configures a second timer for the UE when sending the first RRC response message to the UE. When the UE receives the first RRC response message, the UE starts the second timer, and in some embodiments, the starting condition of the second timer includes that the UE receives the first RRC response message, which is, for example, an rrcreelease message, an RRC release with suspend configuration (rrcreelease with suspend configuration) message, or other RRC messages having the same function but not standardized by 3 GPP. In some embodiments, the UE triggers the RNAU when the second timer times out. In some embodiments, the UE stops the second timer when receiving a second RRC response message sent by the base station, and in some embodiments, the stop condition of the second timer includes that the UE receives the second RRC response message, for example, a rrcreesume message, a RRCSetup message, or a rrcreelease message or other RRC messages having the same function but not standardized by 3 GPP.

And a second condition: the RNAU is triggered by a System Information Block (SIB) 1, and the triggered RNAU is associated with RNA configured by the base station for the UE. In some embodiments, the UE may trigger the RNAU in a case that a serving cell of the UE does not belong to the configured RNA, for example, when the serving cell after the UE performs cell reselection does not belong to the configured RNA, the UE may trigger the RNAU, for example, the terminal moves, and cell reselection occurs. In some embodiments, after the UE reads SIB1 in a serving cell (e.g., a new serving cell after cell reselection), if a cell provided by SIB1 does not belong to a cell list configured by the base station for the UE, or a RAN area provided by SIB1 does not belong to a RAN area list configured by the base station for the UE, the UE may trigger the RNAU. For example, when the cell identifier read by the UE from SIB1 does not belong to the cell identifier included in the cell list configured by the base station for the UE in the RAN-notifiationarenfie, the UE may trigger the RNAU. For example, the TAC of the cell read by the UE from SIB1 does not belong to a TAC included in a RAN area list configured for the UE by the base station in the RAN-notification information, and the UE may trigger the RNAU.

The following is an exemplary description of an implementation of performing an RNAU.

In some embodiments, where the UE triggers the RNAU, the RRC connection recovery procedure for the RNAU may be initiated, and in some embodiments, the UE initiating the RRC connection recovery procedure for the RNAU may include: the RRC layer of the UE initiates a procedure (request of a suspended RRC connection) requesting resumption of the suspended RRC connection. In some embodiments, the UE initiating the RRC connection recovery procedure for the RNAU may include: the UE sends an RRC request message, for example, an RRC recovery request message such as RRCResumeRequest message or RRCResumeRequest1, to the base station, where a resumecuse IE in the RRC request message may be set to rn-Update.

In some embodiments, the UE initiating the RRC connection recovery procedure for the RNAU may further include initializing the RRC connection recovery procedure, which may specifically include: if an emergency service is currently in progress, the UE may select an Access Category (Access Category) of 2, and set the resume IE in the RRC request message sent in the RRC connection recovery procedure to emergency (emergency). If no emergency service is currently ongoing, the UE may select Access Category to be 8. The Access Category may be used for Access barring check (Access barring check), and each Access request may be associated with one Access Category, so that the base station may control the Access request of the UE. In some embodiments, the access request may be a UE-initiated RRC connection recovery request.

In some embodiments, the UE selects Access Category during the initial RRC connection recovery procedure. Then, the UE may perform a Unified Access Control (UAC) procedure, and then determine whether the Access attempts are barred, for example, each Access attempt corresponds to an Access Category, for example, the Access attempt is directed to initiate an RRC connection recovery procedure for the RNAU, where the Access Category is 2 or the Access Category is 8, when the Access attempt is barred, the UE cannot initiate the RRC connection recovery procedure for the RNAU, and when the Access attempt is not barred, the UE may initiate the RRC connection recovery procedure for the RNAU, which is specifically as follows:

alternatively, if the access attempt is barred, the UE may set the first variable to a first value and stop the access attempt.

Optionally, if the Access attempt is barred, the UE may start a timer T390, for example, the UE starts a corresponding timer T390 for the Access Category of the barred Access attempt. When T390 of the Access Category is running, the UE considers that the Access attempt is forbidden, and when T390 of the Access attempt is overtime, for example, T390 of the Access attempt is not running, the UE considers that the prohibition of the Access Category is alleviated, for example, the Access Category is 2 or the Access Category is 8.

The value of the first variable is a first value or a second value, for example, the first variable indicates whether there is a pending RNA Update (pendingRNA-Update), the first value is true (true), and the second value is false (false). In some embodiments, a value of the first variable as the first value may indicate that there is a pending RNA update process. In some embodiments, the value of the first variable to the second value may indicate that there is no pending RNA update process. In some embodiments, the taking of the first variable value as the first value may indicate that the RNAU has been triggered but not successfully performed (which may be understood as unsuccessfully performing an RRC connection recovery procedure for the RNAU).

If the access attempt is not barred, the UE may continue to perform initialization related to the RRC connection recovery procedure, e.g., applying a default physical layer configuration, a default SRB1 configuration, a default MAC layer configuration, etc., and the UE may set the first variable to the second value. Then, the UE may initiate transmission of an RRC request message, for example, restore the RRC configuration, reestablish the PDCP entity of SRB1, recover SRB1, and transmit the RRC request message to a bottom layer of the UE (where the bottom layer is relative to the RRC layer, for example, the MAC layer or the physical layer), for example, after the RRC layer of the UE performs the above initialization procedure, the RRC layer transmits the RRC request message to the MAC layer, and then the MAC layer sends the RRC request message. In some embodiments, the UE in the non-RRC connected state does not configure transmission resources, and when the MAC layer receives a transmission requirement transmitted by the RRC layer, the MAC layer may initiate an RA to transmit an RRC request message for an RNAU, for example, the RRC request message is transmitted in the msg3 or the msgA. In other embodiments, the UE in the non-RRC connected state has a pre-configured resource, such as a CG resource or a PUR, and the description of the pre-configured resource is similar to the description of the pre-configured resource in fig. 9-10 above. When the lower layer receives the transmission requirement sent by the upper layer, the RRC request message for the RNAU may be sent on the pre-configured resource. For example, the lower layer is a MAC layer and the upper layer is an RRC layer. For example, the lower layer is a physical layer and the upper layer is an RRC layer. For example, the bottom layer is a physical layer, the upper layer is an MAC layer, and the MAC layer indicates a transmission requirement to the physical layer after receiving the transmission requirement sent by the RRC. Wherein the resumecommand IE in the RRC request message for RNAU is set to rna-Update. In some embodiments, the base station receives an RRC request message for an RNAU sent by the UE, and may acquire that the UE is currently requesting the RNAU, so that the current state of the UE, for example, a mobility condition, may be known.

In some embodiments, the base station successfully receives the RRC request message for the RNAU sent by the UE, and the base station may send a third RRC response message to the UE after the contention resolution is successful (e.g., after the contention resolution message is sent to the UE), where the third RRC response message is, for example, a rrcreelease message, a rrcreelease with suspension indication message, a rrcreesum message, or other RRC messages with the same function but not standardized by 3 GPP. Alternatively, the UE receives a third RRC response message, and may consider this RNAU to be successful. Specific examples are as follows:

example one: the UE performs RNAU under a current base station (which may be referred to as a new station), but the context of the UE is stored in a last base station (which may be referred to as an old station), the old station may transmit the context of the UE to the new station through an Xn interface, and the new station may transmit an RRC response message to the UE after obtaining the context of the UE, for example, transmit an RRCRelease message to cause the UE to enter an rrciede state, or transmit an RRCRelease with suspension indication message to cause the UE to enter an RRCINACTIVE state, or transmit an rrcresum message to cause the UE to enter an RRCONNECTED state.

Example two: the UE initiates an RNAU at a current base station (which may be referred to as a new station), but the context of the UE is stored in a previous base station (which may be referred to as an old station), the old station does not send the context of the UE to the new station, and at this time, the RRC state of the UE is controlled by the old station, and the old station may indirectly send an RRC response message to the UE through an Xn interface message, that is, send the RRC response message to the new station, and then forward the RRC response message by the new station, for example, forward an rrcreelease message to make the UE enter an RRCIDLE state, or forward an rrcreelease with suspension indication message to make the UE enter an RRC _ INACTIVE state.

In other embodiments, the base station may send the fourth RRC response message to the UE, for example, in case that the base station does not successfully receive the RRC request message for the RNAU sent by the UE, the base station may send the fourth response message to the UE after the contention resolution is successful. The fourth RRC response message is, for example, an RRCConnectionReject message, an RRCReject message, or other RRC messages having the same function but not standardized by 3 GPP. Optionally, the UE may return to the RRC _ INACTIVE state after receiving the fourth RRC response message. Alternatively, the UE may set the first variable to the first value, considering that the RRC recovery request for the RNAU is rejected, upon receiving the fourth RRC response message.

In some embodiments, after receiving the fourth RRC response message, if the fourth RRC response message configures a wait time (wait time), the UE starts the timer T302, where a duration of the timer T302 is equal to the wait time. When the timer T302 is running and the Access Category is not 2 or 0, the ue considers the Access attempt to be barred. When the timer T302 times out, if the T390 of the Access Category is not running, the UE considers that the prohibition of the Access Category is relieved. It should be noted that the timer T302 is prohibited from requesting the UE, and does not distinguish Access Category of the UE.

In some embodiments, the UE currently initiates an RRC connection recovery procedure for the RNAU and selects Access Category of 8, and if the Access attempt is not prohibited and the UE does not turn on T390 with Access Category of 8 when initializing the RRC connection recovery procedure for the RNAU, the UE may continue to perform initialization related to the RRC connection recovery procedure and send an RRC request message for the RRC connection recovery procedure for the RNAU. If the base station sends a fourth RRC response message configured with wait time to the UE, the UE starts a timer T302. When the timer T302 times out, at this time, T390 with Access Category of 8 is not running, and the UE considers that the barring for the Access Category of 8 is alleviated.

In some embodiments, the UE may continue to execute the RNAU by setting the first variable to the first value when the current RNAU has been triggered but was not successfully executed. For example, after the UE triggers the RNAU, the UE may set the first variable to the first value if the access attempt is prohibited or a fourth RRC response message (e.g., RRCReject message) is received during RRC connection recovery for the RNAU. In some embodiments, the UE may continue to attempt to initiate an RRC connection recovery procedure for the RNAU with the first variable set to the first value. In some embodiments, if the barring for Access Category of 8 or Access Category of 2 is alleviated and the upper layer (e.g. NAS layer) does not request to resume the RRC connection, e.g. the upper layer (e.g. NAS layer) does not request to resume the RRC connection for transmitting data, and the first variable is set to the first value, the UE may continue to initiate the RRC connection resumption procedure for the RNAU.

Currently, when a UE and a base station in a non-RRC connected state perform SDT, an RNAU may be triggered, and in this case, a terminal may stop the SDT currently performed and execute the RNAU, so as to affect transmission of small data of the SDT, which is specifically illustrated as follows:

example one: before the UE and the base station perform RASDT, the UE receives an RRCRelease message sent by the base station, starts a second timer (e.g., T380), and then the UE initiates an RRC connection recovery procedure for SDT, for example, a 4-step SDT shown in fig. 5 and 6 or a 2-step SDT shown in fig. 7 and 8, where the second timer may be started before the UE sends random access preamble. If the second timer is timed out before the UE receives the content resolution message sent by the base station, i.e. the RNAU is triggered before the UE receives the content resolution message sent by the base station, it can be understood that a new RA for the RNAU is triggered during the current RA operation for the SDT. In this case, whether the RNAU is executed depends on the UE implementation, i.e. the UE implementation decides to continue the RA procedure currently used for SDT or to execute a new RA for the RNAU. If the UE performs a new RA for the RNAU, it may cause that uplink packet data and downlink packet data cannot be transmitted or transmission fails, for example, uplink packet data transmitted together with msg3 or msgA and downlink packet data transmitted together with RRC response message. If the second timer is expired after the UE receives the content resolution message sent by the base station, i.e. the RNAU is triggered after the UE receives the content resolution message sent by the base station. In this case, the UE needs to discard the currently running RA SDT procedure and initiate an RRC connection recovery procedure for the RNAU, which may result in that the uplink packet data and the downlink packet data cannot be sent or the sending fails, for example, the uplink packet data and/or the downlink packet data that the subsequent transmission needs to transmit and the downlink packet data that is sent together with the RRC response message.

Example two: before the UE and the base station perform CG-SDT, the UE receives an RRCRelease message sent by the base station, starts a second timer (e.g., T380), and then the UE initiates an RRC connection recovery procedure for SDT, for example, the CG-SDT shown in fig. 9 and fig. 10, where the second timer may be started before the UE sends an RRC request message and/or uplink packet data. If the second timer is expired, the UE needs to discard the currently running CG-SDT procedure and initiate an RRC connection recovery procedure for the RNAU, which may result in that the uplink packet data and the downlink packet data may not be sent or the sending may fail, for example, the uplink packet data and/or the downlink packet data that the subsequent transmission needs to transmit, and the downlink packet data that is sent together with the RRC response message.

The embodiment of the application provides a method for controlling transmission, which can be applied to a communication system, wherein the communication system comprises a terminal and a network device, and the terminal and the network device do not trigger an RNAU when performing SDT, so that the influence on the transmission of small data is avoided, for example, the transmission delay is increased, and the power consumption and the signaling overhead are also increased when subsequently initiating the SDT again. When the terminal and the network device perform SDT, the network device can acquire the RNA where the terminal is located, and does not need to additionally execute RNAU to inform the network device of the current state of the terminal.

Next, an example that when the terminal and the network device perform SDT, the network device may obtain the RNA in which the terminal is located is described: the first example is as follows: the base station that the terminal initiates the SDT this time is the same as the base station that the terminal received the rrcreelease message last time, i.e., the terminal receives the rrcreelease message under the same base station, and initiates an RRC connection recovery procedure for the SDT. Optionally, the base station that the terminal received the rrcreelease message last time may be a base station that configures an RNA for the terminal, and the base station may configure information related to the RNA for the terminal through the rrcreelease message, that is, the terminal is configured with the RNA in the same base station, and initiate the SDT. The base station maintains the context of the terminal. The base station may know the RNA in which the terminal is located, for example, the base station may know, based on the context of the terminal stored by the base station, the RNA configured for the terminal before, and at this time, the terminal initiating the SDT does not move out of the configured RNA range, so the base station may know that the RNA in which the terminal is located is the configured RNA.

Example two: the base station (which may be referred to as a new base station) that the terminal initiates the SDT this time is different from the base station (which may be referred to as an old base station) that the terminal received the rrcreelease message last time, i.e., the terminal initiates the RRC connection recovery procedure for the SDT under the new base station. Alternatively, the old base station that the terminal received the rrcreelease message last time may be a base station that configures the RNA for the terminal, and the old base station may configure the information related to the RNA for the terminal through the rrcreelease message. The new base station may know the RNA in which the terminal is located, for example, the new base station may obtain the context of the terminal from the old base station, and the new base station may know whether the terminal is beyond the range of the RNA configured for the terminal by the old base station based on the obtained context of the terminal and/or the information of the old base station. For example, if the RNA configuration acquired by the new base station from the context of the terminal does not include the RNA list or the cell list corresponding to the new base station, it may be known that the terminal has gone outside the configured RNA range, or it may be known that the terminal has not moved outside the configured RNA range. For another example, if the RNA list corresponding to the new base station does not include the RNA list corresponding to the old base station, or the cell list corresponding to the new base station does not include the cell list corresponding to the old base station, it may be known that the terminal is out of the configured RNA range, or it may be known that the terminal is not moved outside the configured RNA range.

Next, a method for controlling transmission provided in the embodiment of the present application is described based on the above description, and the method may be applied to the communication system shown in fig. 1, and the network device and the terminal in the method may be the network device 120 and the UE130 shown in fig. 1.

The following embodiment takes a transmission procedure under a user plane protocol stack as an example for explanation. The first timer and the second timer in the following embodiments may refer to the description of the first timer and the second timer.

In a possible implementation manner, when the terminal is in the non-RRC connected state and the first preset condition is satisfied, the RRC connection recovery procedure for the RNAU is performed, and the description of the RRC connection recovery procedure for the RNAU may refer to the description of initiating the RRC connection recovery procedure for the RNAU in the implementation manner of performing the RNAU.

In some embodiments, the first preset condition includes that the second timer times out and the first timer is not running, a specific example is as shown in fig. 11 below, where the first preset condition is the first condition in fig. 11. In some embodiments, the first preset condition includes that the terminal receives SIB1 of the first serving cell, the first serving cell does not belong to the configured RNA, and the first timer is not run, which is specifically illustrated in fig. 13 below, where the first preset condition is the second condition in fig. 13. The expression example of the above case is as follows:

example one: when the terminal is in the RRC INACTIVE state, if the first timer (e.g., T3 XX) is not running and the second timer (e.g., T380) times out, or if the first timer (e.g., T3 XX) is not running and the serving cell of the terminal does not belong to the configured RNA, the terminal may initiate an RRC connection recovery procedure and set the resume ecause IE in the RRC request message for initiating the RRC connection recovery procedure to RNA-Update.

Example two: when the terminal is in the RRC INACTIVE state, if the second timer (e.g., T380) expires or the serving cell of the terminal does not belong to the configured RNA, if the first timer (e.g., T3 XX) is not running, the terminal may initiate an RRC connection recovery procedure, and set a resumecuse IE in an RRC request message for initiating the RRC connection recovery procedure to RNA-Update.

Alternatively, performing the RRC connection recovery procedure for the RNAU may include in the above example: initiating an RRC connection recovery procedure, and setting a resumeHease IE in an RRC request message for initiating the RRC connection recovery procedure to rna-Update.

Referring to fig. 11, fig. 11 is a flowchart illustrating a method for controlling transmission according to an embodiment of the present disclosure. The method includes, but is not limited to, the steps of:

s401: the terminal starts a second timer.

In some embodiments, S401 is an optional step.

In some embodiments, the terminal receives the first RRC response message, and starts the second timer, in some embodiments, the first RRC response message includes the second timer, and in some embodiments, the first RRC response message includes the second timer duration. The first RRC response message is, for example, an rrcreelease message, an rrcreelease with suspend config message, or other RRC messages having the same function but not standardized by 3 GPP.

S402: and when the first condition is met, the terminal triggers the RNAU.

In some embodiments, the RNAU is triggered when the first condition is met while the terminal is in a non-RRC connected state, optionally a RRC INACTIVE state.

In some embodiments, the first condition comprises the terminal being in an RRC INACTIVE state.

In some embodiments, triggering the RNAU is to perform an RRC connection recovery procedure for the RNAU, and optionally, when performing the RRC connection recovery procedure for the RNAU, the terminal may send an RRC request message to the network device, where the resume _ alarm IE in the RRC request message is rna-Update.

In particular, the first condition comprises the second timer expiring and the first timer not running, optionally the first timer not running is not started.

In some embodiments, when the second timer expires, the terminal may determine whether the first timer is running, and if the first timer is running, the terminal does not trigger the RNAU, and if the first timer is not running, the terminal triggers the RNAU.

In some embodiments, when the second timer expires and the terminal has no SDT requirement while the second timer is running, the terminal may trigger the RNAU, optionally, the first timer not running may represent that the terminal has no SDT requirement, optionally, the second timer is running, and the first timer is not running, which is specifically exemplified as shown in fig. 12 below.

Referring to fig. 12, fig. 12 illustrates a timing diagram.

As shown in FIG. 12, the horizontal axis represents timeAxis (t) at a first time t ₁ The second timer is turned on (e.g., the first RRC response message is received), and at a second time t ₂ The second timer is expired, t ₁ ＜t ₂ . The second timer runs between the first time and the second time, the first timer does not run between the first time and the second time, and the first timer is not started between the first time and the second time. At a second time instant, the second timer times out and the first timer is not running, at which point the terminal may trigger the RNAU.

Optionally, the RRC connection recovery procedure for SDT may include: initiating an RRC connection recovery procedure, and setting a resumecuse IE in an RRC request message for initiating the RRC connection recovery procedure to mo-data.

Referring to fig. 13, fig. 13 is a flowchart illustrating another method for controlling transmission according to an embodiment of the present disclosure. The method includes, but is not limited to, the steps of:

s501: the terminal starts a first timer.

In some embodiments, S501 is an optional step.

In some embodiments, the terminal initiates an RRC connection recovery procedure for SDT, and starts a first timer, optionally, when the terminal sends an RRC request message and/or uplink packet data to the network device, the first timer is started, for example, in the flows shown in fig. 5 to 8, when the terminal sends msg3 or msgA to the network device based on RA-SDT, the first timer is started, for example, in the flows shown in fig. 9 to 10, when the terminal sends an RRC request message and/or uplink packet data to the network device based on CG-SDT, the first timer is started.

S502: the terminal performs cell reselection.

In some embodiments, S502 is an optional step.

In some embodiments, the terminal and the network device perform cell reselection during the SDT, and in some embodiments, when the first timer runs, the terminal performs cell reselection and stops the first timer.

In some embodiments, the terminal performs cell reselection and switches from the first cell to the second cell, that is, the serving cell after the cell reselection of the terminal is the second cell, which is subsequently referred to as the first serving cell, and in some embodiments, the first serving cell of the terminal does not belong to the configured RNA, where the RNA is configured for the terminal by the network device before the cell reselection of the terminal occurs.

In some embodiments, after the terminal performs cell reselection, the terminal receives an SIB1 of a current serving cell, and determines a first serving cell according to the SIB1, where the SIB1 indicates the first serving cell, and in some embodiments, the terminal determines, according to the SIB1, that the first serving cell does not belong to configured RNA, where the RNA is configured for the terminal by the network device before the terminal performs cell reselection, a specific example is as follows:

the first example is as follows: the terminal reads the cell identifier of the first serving cell from the SIB1, and when the read cell identifier of the first serving cell does not belong to the cell identifier included in the cell list configured for the terminal by the network device in the RAN-NotificationAreaInfo IE, the terminal determines that the first serving cell does not belong to the configured RNA.

Example two: the terminal reads the TAC of the first service cell from the SIB1, and when the read TAC of the first service cell does not belong to the TAC included in a RAN area list configured for the terminal by the network equipment in the RAN-Notification information IE, the terminal determines that the first service cell does not belong to the configured RNA.

In some embodiments, after the terminal performs cell reselection, the terminal is in a non-RRC connected state, and optionally, the non-RRC connected state is an RRC INACTIVE state.

S503: and when the second condition is met, the terminal triggers the RNAU.

In some embodiments, the RNAU is triggered when a second condition is met while the terminal is in a non-RRC connected state, optionally a RRC INACTIVE state.

In some embodiments, the second condition comprises the terminal being in an RRC INACTIVE state after a cell reselection.

In some embodiments, triggering the RNAU to perform the RRC connection recovery procedure for the RNAU, optionally, when performing the RRC connection recovery procedure for the RNAU, the terminal may send an RRC request message to the network device, where the resumecuse IE in the RRC request message is rna-Update.

Optionally, the second condition comprises the terminal receiving SIB1 of the first serving cell, the first serving cell does not belong to the configured RNA, and the first timer is not running. In some embodiments, the first serving cell is a serving cell after the terminal performs cell reselection, and in some embodiments, the first serving cell is a cell indicated by SIB1 received after the terminal performs cell reselection, and the terminal determines that the first serving cell does not belong to the configured RNA according to the SIB1 of the first serving cell, for a specific example, see S502.

In some embodiments, the cell reselection occurs when the terminal has no SDT requirement, optionally, the first timer in the second condition is not operated to be not started, and optionally, the first timer is not operated to represent that the terminal has no SDT requirement.

In other embodiments, the terminal performs cell reselection during the SDT, optionally, the terminal operates a first timer during the SDT, and performs cell reselection when the first timer is operating, optionally, the first timer in the second condition is not operated, and stops the first timer, optionally, the terminal stops the first timer when the terminal performs cell reselection, and optionally, the terminal is in an RRC INACTIVE state after the terminal performs cell reselection.

In some embodiments, the second condition further comprises that the terminal may not perform the SDT procedure in the first serving cell. Optionally, the terminal may not perform the SDT procedure in the first serving cell, which is the SDT procedure before the terminal may not continue in the first serving cell, for example, after the terminal performs cell reselection, the terminal may not continue the RRC connection recovery procedure for SDT initiated in S501. Optionally, the terminal may not perform the SDT procedure in the first serving cell, that is, the terminal may not initiate a new SDT procedure in the first serving cell, for example, after the terminal performs cell reselection, the terminal may not continue to initiate a new SDT procedure for the RRC connection recovery procedure for SDT initiated in S501, or may not initiate a new SDT procedure for newly acquired small data. Optionally, the terminal may not perform the SDT procedure in the first serving cell, and the terminal does not have configuration information related to the SDT in the first serving cell, for example, the first serving cell does not support the SDT, and optionally, the first serving cell does not support the SDT including that the first serving cell does not broadcast the configuration related to the SDT in the system information. As another example, the first serving cell does not support RA-SDT and/or CG-SDT.

In some embodiments, when the terminal receives SIB1 of the current serving cell after cell reselection, and the first serving cell indicated by SIB1 does not belong to the configured RNA, the terminal may determine whether the first timer is running. If the first timer runs, the terminal does not trigger the RNAU, and continues the SDT, optionally, the first timer runs as the first timer continues to run, the terminal may continue the previous SDT procedure in the serving cell, for example, after the terminal performs cell reselection, the first timer continues to run, and the terminal may continue the RRC connection recovery procedure for SDT initiated in S501 in the serving cell. Optionally, the first timer is operated to start the first timer, and the terminal may initiate a new RRC connection recovery procedure for SDT in the serving cell, for example, after the terminal performs cell reselection, initiate a new RRC connection recovery procedure for SDT, and start the first timer. If the first timer is not running, the terminal triggers an RNAU, which is optionally triggered by SIB 1.

In some embodiments, when the terminal performs SDT, the second timer may time out, and the terminal may determine whether the first timer is running. If the first timer runs, the terminal does not trigger the RNAU, and the SDT process is continued. And after the second timer is overtime, the terminal reselects the cell, stops the first timer and is in an RRC INACTIVE state. The terminal may perform an RRC connection recovery procedure for the RNAU when the second condition is satisfied.

In other embodiments, the terminal is in an RRC IDLE state after cell reselection, and the terminal does not trigger the RNAU. In other embodiments, after the terminal performs the cell reselection, the terminal may perform the SDT procedure in the first serving cell, and then the terminal does not trigger the RNAU and performs the SDT procedure. Optionally, a situation that the terminal may perform the SDT procedure in the first serving cell is opposite to the situation that the terminal may not perform the SDT procedure in the first serving cell, which may be specifically referred to in the foregoing description.

It can be understood that compared to the two cases of triggering RNAU illustrated above, the embodiment of the present application adds a triggering condition: the first timer does not run, that is, the terminal does not have an SDT requirement or can trigger the RNAU after the SDT process is completed, and the first timer does not run (for example, during the SDT process), the RNAU is not triggered, wherein when the SDT process is performed, the network device can obtain the RNA where the terminal is located, and when the RNAU is not executed, the state of the network device obtaining the terminal is not affected, and packet data affecting the SDT process transmission can be avoided, for example, the increase of transmission delay is avoided, and unnecessary signaling overhead and power consumption are increased by subsequently restarting the SDT.

In a possible implementation manner, the terminal receives the RRC reject message, and if the second timer is not running, the terminal may set the first variable to a first value, where the first variable is a value indicating that there is an undetermined RNAU, and optionally, a value of the first variable is a first value or a second value, for example, whether the first variable indicates that there is a pendingRNA-Update, the first value is true, and the second value is false. The description of the first variable and the first value can be referred to the description of the first variable and the first value in the above implementation of performing RNAU, and a specific example is shown in fig. 14 below.

Referring to fig. 14, fig. 14 is a flowchart illustrating another method for controlling transmission according to an embodiment of the present application. The method includes, but is not limited to, the steps of:

s601: the terminal starts a second timer.

In some embodiments, S601 is an optional step, and S601 is similar to S401 of fig. 11.

S602: the terminal starts a first timer.

In some embodiments, S602 is an optional step, and S602 is similar to S501 of fig. 13.

In some embodiments, the execution sequence of S601 and S602 may be that S601 is executed first and S602 is executed later, or that S602 is executed first and S601 is executed later.

S603: the network equipment sends RRCRreject message to the terminal.

In some embodiments, S603 is an optional step.

In some embodiments, when the first timer runs, the terminal receives the RRCReject message and stops the first timer.

In some embodiments, the terminal receives the RRCReject message in the RRC INACTIVE state.

In some embodiments, when the terminal initiates an RRC connection recovery procedure for SDT to the network device, the terminal sends an RRC request message to the network device, where the RRCReject message is sent by the network device in response to the RRC request message. The RRC request message is, for example, an RRC recovery request message such as rrcresemequest message or rrcresemequest 1.

S604: if the second timer is not running, the terminal sets the first variable to a first value.

In some embodiments, the terminal receives the RRCReject message and is in a non-RRC connected state, optionally, the non-RRC connected state is an RRC INACTIVE state.

In some embodiments, the terminal receives the RRCReject message, considers that the SDT procedure fails (is rejected), the terminal is in the RRC INACTIVE state, and the terminal still needs to perform a periodic RNAU, but since the second timer is not running at this time, the terminal may set the first variable to the first value.

In some embodiments, if the terminal is in the RRC INACTIVE state after receiving the RRCReject message and the second timer is not running, the terminal may set the first variable to the first value.

In some embodiments, when the terminal receives the RRCReject message and the RRCReject message configures wait time, the terminal may start the timer T302, and optionally, the RRC connection recovery procedure of the UE is prohibited when the timer T302 runs. When the timer T302 times out, the RRC connection recovery procedure that the UE is prohibited from is alleviated, and if the upper layer (e.g., NAS layer) does not request to recover the RRC connection at this time, the UE may initiate the RRC connection recovery procedure again, for example, the upper layer (e.g., NAS layer) does not request to recover the RRC connection for transmitting data, and the first variable is set to the first value, and the UE may continue to initiate the RRC connection recovery procedure for the RNAU.

In some embodiments, during the SDT procedure (e.g., before receiving the RRCReject message), the second timer expires, and the terminal may determine whether the first timer is running. If the first timer runs, the terminal does not trigger the RNAU, and the SDT process is continued. And after the second timer is overtime, the terminal receives the RRCRreject message, the first timer is stopped, and the terminal is in an RRC INACTIVE state. If the second timer is not running, the terminal may set the first variable to a first value. Optionally, the second timer is not running, and is not running after the second timer times out.

In other embodiments, the terminal receives the RRCReject message in the RRC IDLE state, and the terminal does not trigger the RNAU and sets the first variable to the first value.

Not limited to the RRC reject message illustrated in fig. 14, in other embodiments, the RRC reject message may also be an RRCConnectionReject message or other RRC messages having the same function but not standardized by 3 GPP.

Not limited to the example shown in fig. 14, in other embodiments, the terminal receives the RRC reject message, and if the second timer is not running, the terminal may directly perform the RRC connection recovery procedure for the RNAU, which is similar to fig. 14 except that the setting of the first variable to the first value in fig. 14 is replaced by performing the RRC connection recovery procedure for the RNAU, for example, the RRC layer of the terminal performs the RRC connection recovery procedure for the RNAU. Optionally, the terminal receives the RRCReject message, and the RRCReject message does not configure wait time, and the terminal performs the RRC connection recovery procedure for the RNAU, for example, the RRC layer of the terminal directly performs the RRC connection recovery procedure for the RNAU.

In other embodiments, the terminal may set the first variable to the first value, and then the terminal performs the RRC connection recovery procedure for the RNAU, for example, the RRC layer of the terminal directly performs the RRC connection recovery procedure for the RNAU.

In other embodiments, the terminal receives the RRC reject message, may start a third timer if the second timer is not running, and when the third timer expires and if the first timer is not running, the terminal performs an RRC connection recovery procedure for the RNAU, which is similar to fig. 14, except that the setting of the first variable to the first value in fig. 14 is replaced with the starting of the third timer. Optionally, the method further comprises: and when the third timer is overtime, if the first timer does not run, the terminal executes an RRC connection recovery process for the RNAU.

Optionally, the third timer is the same as the second timer, e.g., the duration of the third timer is equal to the duration of the second timer. For example, the third timer is T380.

Optionally, the third timer is different from the second timer, e.g. the duration of the third timer is not equal to the duration of the second timer. For example, the third timer duration is less than the duration of the second timer, for example, the third timer duration may be in milliseconds or seconds.

Optionally, during the running of the third timer, the terminal may wait whether the NAS layer has a data transmission requirement, for example, whether the NAS layer triggers the RRC layer to initiate a connection recovery procedure. If the NAS layer has a data transmission requirement and triggers the RRC layer to initiate a connection recovery procedure, the terminal will initiate an RRC connection recovery procedure for data transmission without performing the RRC connection recovery procedure for RNAU, which includes RRC connection recovery procedures for SDT and for non-SDT.

In some embodiments of the present invention, the,

1>else if RRCReject is received in response to an RRCResumeRequest or an RRCResumeRequest1：

2>if resume is triggered due to an SDT procedure,and

2>if T380 expires：

3>set the variable pendingRNA-Update to true.

in some embodiments, if the terminal receives a RRCReject message in response to the rrcresemequest message or the rrcresemequest 1 message, the terminal may set the first variable to a first value if the recovery is triggered based on the SDT procedure and the second timer expires, wherein the terminal may request the recovery by sending the rrcresemequest message or the rrcresemequest 1 message. Optionally, the recovering is an RRC connection recovering procedure for SDT.

In a possible implementation manner, when the first timer is expired, if the second timer is not running, the terminal may set the first variable to a first value, where the first variable is the first value and indicates that there is a pending RNAU, and the descriptions of the first variable and the first value may refer to the descriptions of the first variable and the first value in the implementation manner of executing the RNAU, which is specifically illustrated in fig. 15 below.

Referring to fig. 15, fig. 15 is a flowchart illustrating another method for controlling transmission according to an embodiment of the present application. The method includes, but is not limited to, the steps of:

s701: the terminal starts a second timer.

In some embodiments, S701 is an optional step, and S701 is similar to S401 of fig. 11.

S702: the terminal starts a first timer.

In some embodiments, S702 is an optional step, and S702 is similar to S501 of fig. 13.

In some embodiments, the execution sequence of S701 and S702 may be that S701 is executed first, and S702 is executed later, or that S702 is executed first, and S701 is executed later.

S703: when the first timer is overtime, if the second timer is not running, the terminal sets the first variable as a first value.

In some embodiments, after the first timer expires, the terminal is in a non-RRC connected state, optionally, the non-RRC connected state is an RRC INACTIVE state, and in some embodiments, when the terminal is in the RRC INACTIVE state, an RRC connection recovery procedure for the SDT is initiated to the network device, and the first timer is started. After the first timer is overtime, the terminal is still in the RRC INACTIVE state.

In some embodiments, the first timer may time out, the terminal may be in the RRC INACTIVE state, and the terminal may still need to perform the periodic RNAU, but since the second timer is not running, the terminal may set the first variable to the first value.

In some embodiments, if the terminal is in the RRC INACTIVE state after the first timer expires and the second timer is not running, the terminal sets the first variable to the first value.

In some embodiments, during the SDT procedure performed by the terminal (e.g., before the first timer expires), the second timer expires, and the terminal may determine whether the first timer is running. If the first timer runs, the terminal does not trigger the RNAU, and the SDT process is continued. And after the second timer is overtime, if the first timer is overtime, the terminal is in an RRC INACTIVE state. If the second timer is not running, the terminal may set the first variable to the first value. Optionally, the second timer is not running, and is not running after the second timer times out.

In other embodiments, the first timer expires while the terminal is in the RRC IDLE state, and the terminal does not trigger the RNAU and does not set the first variable to the first value.

Not limited to the example shown in fig. 15, in other embodiments, when the first timer expires and if the second timer is not running, the terminal may directly perform the RRC connection recovery procedure for the RNAU, and the specific example is similar to fig. 15 except that the setting of the first variable to the first value in fig. 15 is replaced by performing the RRC connection recovery procedure for the RNAU, for example, the RRC layer of the terminal performs the RRC connection recovery procedure for the RNAU.

In other embodiments, the terminal may set the first variable to the first value, and then the terminal performs the RRC connection recovery procedure for the RNAU, for example, the RRC layer of the terminal directly performs the RRC connection recovery procedure for the RNAU.

In other embodiments, the terminal may start a third timer if the second timer is not running when the first timer expires, and perform an RRC connection recovery procedure for the RNAU if the first timer is not running when the third timer expires, which is similar to fig. 15 except that the setting of the first variable as the first value in fig. 15 is replaced by starting the third timer. Optionally, the method further comprises: and when the third timer is overtime, if the first timer does not run, the terminal executes an RRC connection recovery process for the RNAU.

Optionally, the third timer is the same as the second timer, e.g., the duration of the third timer is equal to the duration of the second timer. For example, the third timer is T380.

Optionally, the third timer is different from the second timer, e.g. the duration of the third timer is not equal to the duration of the second timer. For example, the third timer duration is less than the duration of the second timer, for example, the third timer duration may be in milliseconds or seconds.

Optionally, during the running of the third timer, the terminal may wait whether the NAS layer has a data transmission requirement, for example, whether the NAS triggers the RRC layer to initiate a connection recovery procedure. If the NAS layer has a data transmission requirement and triggers the RRC layer to initiate a connection recovery procedure, the terminal will initiate an RRC connection recovery procedure for data transmission without performing the RRC connection recovery procedure for RNAU, which includes RRC connection recovery procedures for SDT and for non-SDT.

In a possible implementation manner, when receiving the SIB1 of the second serving cell, if the second serving cell belongs to the configured RNA and the second timer is not running, the terminal may set the first variable to a first value, where the first variable is the first value indicating that there is a pending RNAU, and the description of the first variable and the first value may refer to the description of the first variable and the first value in the implementation manner of performing RNAU, as shown in fig. 16 below.

Referring to fig. 16, fig. 16 is a flowchart illustrating another method for controlling transmission according to an embodiment of the present application. The method includes, but is not limited to, the steps of:

s801: the terminal starts a second timer.

In some embodiments, S801 is an optional step, and S801 is similar to S401 of fig. 11.

S802: the terminal starts a first timer.

In some embodiments, S802 is an optional step, and S802 is similar to S501 of fig. 13.

In some embodiments, the execution sequence of S801 and S802 may be that S801 is executed first, and S802 is executed later, or that S802 is executed first, and S801 is executed later.

S803: the terminal performs cell reselection.

In some embodiments, S803 is an optional step.

In some embodiments, the terminal and the network device perform cell reselection during the SDT, and in some embodiments, when the first timer runs, the terminal performs cell reselection and stops the first timer.

In some embodiments, the terminal performs cell reselection and switches from the third cell to a fourth cell, that is, a serving cell after the cell reselection of the terminal is a fourth cell, which is subsequently referred to as a second serving cell, and in some embodiments, the second serving cell of the terminal belongs to configured RNA, where the RNA is configured for the terminal by the network device before the cell reselection of the terminal.

In some embodiments, after a cell reselection occurs in a terminal, the terminal receives an SIB1 of a current serving cell, and determines a second serving cell according to the SIB1, where the SIB1 indicates the second serving cell, and in some embodiments, the terminal determines that the second serving cell belongs to configured RNA according to the SIB1, where the RNA is configured for the terminal by a network device before the cell reselection occurs in the terminal, and a specific example is similar to S502 in fig. 11 and is not described again.

In some embodiments, after the terminal performs cell reselection, the terminal is in a non-RRC connected state, which is optionally an RRC INACTIVE state.

S804: if the second serving cell belongs to the configured RNA and the second timer is not running, the terminal sets the first variable to a first value.

In some embodiments, after the terminal performs cell reselection, the terminal is in a non-RRC connected state, optionally, the non-RRC connected state is an RRC INACTIVE state, and in some embodiments, when the terminal is in the RRC INACTIVE state, an RRC connection recovery procedure for SDT is initiated to the network device, and the first timer is started. When the first timer runs, cell reselection occurs, and the terminal is still in an RRC INACTIVE state.

In some embodiments, if the terminal is in RRC INACTIVE state after cell reselection and the second serving cell belongs to the configured RNA, the second timer is not running, and the terminal may set the first variable to a first value.

In some embodiments, if the terminal is in the RRC INACTIVE state, and the second serving cell belongs to the configured RNA, and the second timer is not running, and the terminal cannot perform the SDT procedure in the second serving cell, the terminal may set the first variable to the first value. Optionally, the terminal may not perform the SDT procedure in the second serving cell is that the terminal may not continue the previous SDT procedure in the second serving cell, for example, after the terminal performs cell reselection, the terminal may not continue the RRC connection recovery procedure for SDT initiated in S802. Optionally, the terminal may not perform the SDT procedure in the second serving cell, that is, the terminal may not initiate a new SDT procedure in the second serving cell, for example, after the terminal performs cell reselection, the terminal may not continue to initiate a new SDT procedure for the RRC connection recovery procedure for SDT initiated in S802, or may not initiate a new SDT procedure for newly acquired small data. Optionally, the terminal may not perform the SDT procedure in the second serving cell, so that the terminal does not have configuration information related to the SDT in the second serving cell, for example, the second serving cell does not support the SDT, and optionally, the second serving cell does not support the SDT including that the second serving cell does not broadcast the configuration related to the SDT in the system information. As another example, the second serving cell does not support RA-SDT and/or CG-SDT.

In some embodiments, the terminal performs cell reselection, is in an RRC INACTIVE state, and still needs to perform a periodic RNAU, but since the second timer is not running, the terminal may set the first variable to the first value.

In some embodiments, during the SDT (e.g., before cell reselection occurs) performed by the terminal, the second timer may expire, and the terminal may determine whether the first timer is running. If the first timer runs, the terminal does not trigger the RNAU, and the SDT process is continued. Optionally, the first timer is run to continue running of the first timer, and the terminal may continue the previous SDT procedure in the second serving cell, optionally, the first timer is run to start the first timer, and the terminal may initiate a new RRC connection recovery procedure for SDT in the second serving cell. And after the second timer is overtime, the terminal reselects the cell, stops the first timer and is in an RRC INACTIVE state. If the second timer is not running, the terminal may set the first variable to the first value. Optionally, the second timer is not running, and is not running after the second timer times out.

In other embodiments, after the cell reselection, the terminal is in an RRC IDLE state, and the terminal does not trigger the RNA, and does not set the first variable to the first value, and in other embodiments, after the cell reselection, the terminal may perform an SDT procedure in the second serving cell, and the terminal does not trigger the RNA, and does not set the first variable to the first value.

Not limited to the example shown in fig. 16, in other embodiments, when receiving SIB1 of the second serving cell, if the second serving cell belongs to the configured RNA and the second timer is not running, the terminal may directly perform the RRC connection recovery procedure for the RNAU, the specific example being similar to fig. 16, except that setting the first variable to the first value in fig. 16 is replaced by performing the RRC connection recovery procedure for the RNAU, e.g., the RRC layer of the terminal performs the RRC connection recovery procedure for the RNAU.

In other embodiments, the terminal may set the first variable to the first value, and then the terminal performs the RRC connection recovery procedure for the RNAU, for example, the RRC layer of the terminal directly performs the RRC connection recovery procedure for the RNAU.

In other embodiments, when receiving SIB1 of the second serving cell, if the second serving cell belongs to the configured RNA and the second timer is not running, the terminal starts a third timer, which is similar to fig. 16 except that the setting of the first variable to the first value in fig. 16 is replaced by starting the third timer. Optionally, the method further comprises: and when the third timer is overtime, if the first timer does not run, the terminal executes an RRC connection recovery process for the RNAU.

Optionally, the third timer is the same as the second timer, e.g., the duration of the third timer is equal to the duration of the second timer. For example, the third timer is T380.

Optionally, the third timer is different from the second timer, e.g. the duration of the third timer is not equal to the duration of the second timer. For example, the third timer duration is less than the duration of the second timer, e.g., the third timer duration is in milliseconds or seconds.

Optionally, during the running of the third timer, the terminal may wait whether the NAS layer has a data transmission requirement, for example, whether the NAS layer triggers the RRC layer to initiate a connection recovery procedure. If the NAS layer has a data transmission requirement and triggers the RRC layer to initiate a connection recovery procedure, the terminal will initiate an RRC connection recovery procedure for data transmission without performing the RRC connection recovery procedure for RNAU, which includes RRC connection recovery procedures for SDT and for non-SDT.

In some embodiments, 1>, if cell reselection occure while T319 or T302 or T3XX is running:

2>if T380 expires during an SDT procedure or has expired during an SDT procedure:

3>set the variable pendingRNA-Update to true.

in some embodiments, if the terminal performs cell reselection while the timer T319, the timer T302, or the first timer T3XX is running, if the second timer T380 times out during the SDT or has timed out, the terminal may set the variable pendingRNA-Update to true.

In a possible implementation manner, when the integrity check of the terminal fails, if the second timer is not running, the terminal may set the first variable to a first value, where the first variable is a first value indicating that there is a pending RNAU, and the descriptions of the first variable and the first value may refer to the descriptions of the first variable and the first value in the above implementation manner of performing RNAU, and a specific example is shown in fig. 17 below.

Referring to fig. 17, fig. 17 is a flowchart illustrating another method for controlling transmission according to an embodiment of the present application. The method includes, but is not limited to, the steps of:

s901: the terminal starts a second timer.

In some embodiments, S901 is an optional step, and S901 is similar to S401 of fig. 11.

S902: the terminal starts a first timer.

In some embodiments, S902 is an optional step, and S902 is similar to S501 of fig. 13.

In some embodiments, the execution sequence of S901 and S902 may be that S901 is executed first, and S902 is executed later, or that S902 is executed first, and S901 is executed later.

S903: when the integrity check of the terminal fails, if the second timer is not running, the terminal sets the first variable to be a first value.

In some embodiments, the integrity check of the terminal fails when the first timer runs. In some embodiments, the integrity check failure of the terminal is: the RRC layer of the terminal receives the integrity check failure indicated by the bottom layer of the RRC layer, for example, the PDCP layer.

In some embodiments, after the integrity check of the terminal fails, the terminal is in an RRC INACTIVE state, and in some embodiments, when the terminal is in the RRC INACTIVE state, an RRC connection recovery procedure for SDT is initiated to the network device, and the first timer is started. And after the integrity check of the terminal fails when the first timer runs, the terminal is still in an RRC INACTIVE state.

In some embodiments, the integrity check of the terminal fails, the terminal is in the RRC INACTIVE state, and the terminal still needs to perform a periodic RNAU, but since the second timer is not running at this time, the terminal may set the first variable to the first value.

In some embodiments, during the SDT procedure performed by the terminal (e.g., before the integrity check of the terminal fails), the second timer may time out, and the terminal may determine whether the first timer is running. If the first timer runs, the terminal does not trigger the RNAU, and the SDT process is continued. And after the second timer is overtime, if the integrity check of the terminal fails, the terminal is in an RRC INACTIVE state. If the second timer is not running, the terminal may set the first variable to a first value. Optionally, the second timer is not running, and is not running after the second timer times out.

In other embodiments, the integrity check of the terminal fails, the terminal is in an RRC IDLE state, and the terminal does not trigger the RNAU and does not set the first variable to the first value.

Without being limited to the example shown in fig. 17, in other embodiments, when the integrity check of the terminal fails, if the second timer is not running, the terminal may directly perform the RRC connection recovery procedure for the RNAU, which is similar to fig. 17 except that the setting of the first variable to the first value in fig. 17 is replaced by performing the RRC connection recovery procedure for the RNAU, for example, the RRC layer of the terminal performs the RRC connection recovery procedure for the RNAU.

In other embodiments, the terminal may set the first variable to the first value and then the terminal performs the RRC connection recovery procedure for the RNAU, for example, the RRC layer of the terminal directly performs the RRC connection recovery procedure for the RNAU.

In other embodiments, when the integrity check of the terminal fails, if the second timer is not running, the terminal may start a third timer, and when the third timer is expired, if the first timer is not running, the terminal performs an RRC connection recovery procedure for the RNAU, which is similar to fig. 17 except that the setting of the first variable as the first value in fig. 17 is replaced by starting the third timer. Optionally, the method further comprises: and when the third timer is overtime, if the first timer does not run, the terminal executes an RRC connection recovery process for the RNAU.

Optionally, the third timer is the same as the second timer, e.g., the duration of the third timer is equal to the duration of the second timer. For example, the third timer is T380.

Optionally, the third timer is different from the second timer, e.g., the duration of the third timer is not equal to the duration of the second timer. For example, the third timer duration is less than the duration of the second timer, e.g., the third timer duration is in milliseconds or seconds.

Optionally, during the running of the third timer, the terminal may wait whether the NAS layer has a data transmission requirement, for example, whether the NAS triggers the RRC layer to initiate a connection recovery procedure. If the NAS layer has a data transmission requirement and triggers the RRC layer to initiate a connection recovery procedure, the terminal will initiate an RRC connection recovery procedure for data transmission without performing the RRC connection recovery procedure for RNAU, which includes RRC connection recovery procedures for SDT and for non-SDT.

It can be understood that, in the application, the RNAU is not triggered when the SDT process is performed, where when the SDT process is performed, the network device may obtain the RNA where the terminal is located, and not performing the RNAU does not affect the state of the network device obtaining the terminal, but also may avoid affecting the packet data transmitted in the SDT process.

And, for the case that the SDT abnormally ends (e.g., the fourth RRC response message is received, the cell reselection occurs, the first timer times out, or the integrity check of the terminal fails), if the second timer does not run (e.g., does not run after the time-out), the terminal may set the first variable to the first value, so that the subsequent UE may continue to periodically trigger the RNAU without affecting the normal execution of the RNAU.

In one possible implementation, if the first variable is set to the first value in the SDT procedure, the terminal may perform an RRC connection recovery procedure for the RNAU. In some embodiments, if the first variable is set to the first value in the SDT procedure and the upper layer (e.g., NAS layer) does not request to recover the RRC connection, the terminal performs the RRC connection recovery procedure for the RNAU. In some embodiments, if the barring of the terminal with the Access Category of 2 or the Access Category of 8 is alleviated and an upper layer (e.g., NAS layer) does not request to resume the RRC connection and the first variable is set to the first value, the terminal performs the RRC connection resumption procedure for the RNAU. In some embodiments, if the barring of the Access Category of the terminal in the SDT procedure is mitigated and an upper layer (e.g., NAS layer) does not request to restore the RRC connection and the first variable is set to the first value, the terminal performs the RRC connection restoration procedure for the RNAU. In some embodiments, if the access barring is mitigated and an upper layer (e.g., NAS layer) does not request the RRC layer to perform RRC connection recovery, the terminal may perform an RRC connection recovery procedure for the RNAU if the first variable is the first value.

Referring to fig. 18, fig. 18 illustrates yet another timing diagram.

As shown in FIG. 18, the horizontal axis represents the time axis (t), and at the third time t ₃ The second timer is started (e.g., the first RRC response message is received), and at the fourth time t ₄ The first timer is turned on (e.g., sending an RRC request message), and at a fifth time t ₅ The second timer is overtime and at a sixth time t ₆ First fixed ofTimer stopped or timed out, t ₃ ＜t ₄ ＜t ₅ ＜t ₆ . The second timer runs between the third time and the fifth time, the first timer runs between the fourth time and the sixth time, and the terminal performs the SDT process between the fourth time and the sixth time. At the fifth moment, in the SDT process of the terminal, the second timer is overtime, and the terminal does not trigger the RNAU, that is, when the second timer is overtime and the first timer is running, the terminal does not trigger the RNAU.

In some embodiments, at the sixth time, the terminal performs cell reselection, the first timer is stopped, the terminal is in an RRC INACTIVE state, and if the serving cell of the terminal after cell reselection does not belong to the configured RNA and the terminal may not perform an SDT procedure in the serving cell, the terminal may trigger the RNAU, and optionally trigger the RNAU to perform an RRC connection recovery procedure for the RNAU, which may be specifically described in reference to fig. 13.

In other embodiments, at the sixth time, the terminal receives the fourth RRC response message, the first timer is stopped, the terminal is in the RRC INACTIVE state, and if the second timer is not running, the terminal may trigger the RNAU, and optionally, trigger the RNAU to set the first variable to the first value, which may be described with reference to fig. 14 above.

In other embodiments, at the sixth time, the first timer expires, and the terminal is in the RRC INACTIVE state, and if the second timer is not running, the terminal may trigger the RNAU, and optionally, trigger the RNAU to set the first variable to the first value, which may be specifically described with reference to fig. 15.

In other embodiments, at the sixth time, the terminal performs cell reselection, the first timer is stopped, the terminal is in an RRC INACTIVE state, and if a serving cell of the terminal after the cell reselection belongs to the configured RNA, the terminal may not perform an SDT procedure in the serving cell, and the second timer is not run at this time, the terminal may trigger the RNAU, and optionally, trigger the RNAU to set the first variable to the first value, which may be specifically described with reference to fig. 16.

In other embodiments, at the sixth time, the integrity check of the terminal fails, the first timer is stopped, the terminal is in the RRC INACTIVE state, and if the second timer is not running, the terminal may trigger the RNAU, and optionally, the RNAU is triggered to set the first variable to the first value, which may be described with reference to fig. 17 above.

In one possible implementation manner, when the terminal performs the SDT procedure, the second timer may be stopped, which is illustrated in fig. 19 as a specific example below.

Referring to fig. 19, fig. 19 is a flowchart illustrating another method for controlling transmission according to an embodiment of the present disclosure. The method includes, but is not limited to, the steps of:

s1001: the terminal sends an RRC request message to the network device.

In some embodiments, S1001 is an optional step.

In some embodiments, when the terminal has a need for SDT, an RRC connection recovery procedure for SDT may be initiated, which may include the terminal sending an RRC request message to the network device based on SDT.

In some embodiments, when the terminal has a requirement of SDT, it may initiate an RRC connection recovery procedure for 4-step SDT, which may refer to the procedures shown in fig. 5-6, where the RRC request message sent by the terminal in the RRC connection recovery procedure is sent based on 4-step SDT, and the RRC request message may be in msg3.

In some embodiments, when the terminal has a requirement of SDT, it may initiate an RRC connection recovery procedure for 2-step SDT, which may refer to the flows shown in fig. 7-8 above, where the RRC request message sent by the terminal in the RRC connection recovery procedure is sent based on 2-step SDT, and the RRC request message may be in msgA.

In some embodiments, when the terminal has a need of SDT, it may initiate an RRC connection recovery procedure for CG-SDT, which may refer to the flow illustrated in fig. 9-10 above, where the RRC request message sent by the terminal in the RRC connection recovery procedure is sent based on CG-SDT.

In some embodiments, when the terminal sends the RRC request message to the network device, the terminal sends uplink packet data together, for example, the flows shown in fig. 5, fig. 7, and fig. 9.

S1002: the network equipment sends a first response message to the terminal.

In some embodiments, S1002 is an optional step.

In some embodiments, the network device may send the first response message to the terminal after receiving the RRC request message sent by the terminal, and in some embodiments, the network device may send the first response message to the terminal after receiving the RRC request message and the uplink packet data sent by the terminal.

In some embodiments, the terminal initiates an RA-SDT, the network device receives an RRC request message sent by the terminal based on the RA-SDT, and may send a first response message to the terminal, optionally, the first response message may indicate that contention resolution is successful, optionally, the first response message may indicate that a random access procedure is successfully completed, optionally, the terminal receives the first response message and determines that contention resolution is successful, optionally, the terminal receives the first response message and determines that the random access procedure is successfully completed, optionally, the first response message is a contention resolution message shown in fig. 5 to 8.

In some embodiments, the terminal initiates CG-SDT, the network device receives an RRC request message sent by the terminal based on the CG-SDT, and may send a first response message to the terminal, optionally, the first response message may be for the RRC request message and/or the uplink packet data sent in S1001, optionally, the first response message may indicate that the RRC request message is successfully sent, optionally, the first response message may indicate that the uplink packet data is successfully sent, optionally, the first response message is a feedback response message shown in fig. 9 to 10, optionally, the first response message may be Downlink Control Information (DCI) for scheduling retransmission, and optionally, the first response message may be DCI for scheduling retransmission.

S1003: the bottom layer of the terminal indicates the first information to the upper layer.

In some embodiments, S1003 is an optional step.

In particular, the terminal may comprise a plurality of layers, specific examples of which may refer to layers comprised in the user plane protocol stack or the control plane protocol stack shown in fig. 2-3 above. It is to be understood that the bottom layer and the upper layer in S1003 are relative concepts, and in some embodiments, the bottom layer of the terminal in S1003 is a first layer, and the first layer is a layer in a user plane protocol stack or a control plane protocol stack, and in some embodiments, the first layer is a layer that receives the first response message sent by the network device. In some embodiments, the upper layer in S1003 is a second layer, and the second layer is a layer above the first layer.

For example, the first layer is a MAC layer and the second layer is an RRC layer.

For example, the first layer is a physical layer and the second layer is a MAC layer.

For example, the first layer is a physical layer and the second layer is an RRC layer.

S1004: the terminal stops the second timer.

In some embodiments, the third layer of the terminal receives the first information indicated by the bottom layer of the third layer, and stops the second timer, optionally, the third layer is an RRC layer, optionally, the bottom layer of the third layer is a MAC layer, and optionally, the bottom layer of the third layer is a physical layer.

In some embodiments, in the RA-SDT procedure, the MAC layer of the terminal receives a first response message sent by the network device, and the MAC layer indicates first information to an RRC layer above the MAC layer, optionally, the first information indicates that contention resolution is successful, and optionally, the first indication information indicates that the random access procedure is successfully completed. And the RRC layer receives the first information indicated by the MAC layer and stops the second timer. Optionally, the bottom layer in S1003 is a MAC layer, the upper layer is an RRC layer, and the part that stops the second timer in S1004 is the RRC layer.

In some embodiments, in the CG-SDT process, the MAC layer of the terminal receives the first response message sent by the network device, the MAC layer indicates the first information to the RRC layer above the MAC layer, the first information indicates that the sending of the RRC request message and/or the uplink packet data is successful, and the RRC layer receives the first information indicated by the MAC layer and stops the second timer. Optionally, the bottom layer in S1003 is a MAC layer, the upper layer is an RRC layer, and the part that stops the second timer in S1004 is the RRC layer.

In some embodiments, in the CG-SDT process, a physical layer of the terminal receives a first response message sent by the network device, the physical layer indicates first information to an RRC layer above the physical layer, the first information indicates that sending of the RRC request message and/or the uplink packet data is successful, and the RRC layer receives the first information indicated by the physical layer and stops the second timer. Optionally, the bottom layer in S1003 is a physical layer, the upper layer is an RRC layer, and the part for stopping the second timer in S1004 is the RRC layer.

In some embodiments, in the CG-SDT process, a physical layer of the terminal receives a first response message sent by the network device, and the physical layer indicates second information to a MAC layer above the physical layer, where the second information indicates that the RRC request message and/or the uplink packet data is successfully sent. The MAC layer receives the second information indicated by the physical layer and indicates the first information to the RRC layer above the MAC layer, the first information indicates that the RRC request message and/or the uplink packet data are successfully sent, and the RRC layer receives the first information indicated by the MAC layer and stops the second timer. Optionally, the bottom layer in S1003 is a MAC layer, the upper layer is an RRC layer, and the part that stops the second timer in S1004 is the RRC layer.

In some embodiments, the second timer is in an on state before the terminal stops the second timer, e.g., the terminal starts the second timer before initiating an RRC connection recovery procedure for SDT (as in S1001).

In some embodiments, after the terminal stops the second timer, a subsequent transmission may be performed based on the SDT procedure, which may be specifically described in the description of subsequent transmission in fig. 5 to fig. 10 above. The second timer is stopped and does not time out, so that the RNAU is not triggered, and the transmission of small data in the SDT process is not influenced.

In some embodiments, after the terminal stops the second timer, the terminal may receive an RRC response message sent by the network device, which may be specifically described in the RRC response message in fig. 5 to fig. 10. In some embodiments, after the terminal stops the second timer, and receives a first RRC response message sent by the network device, for example, an rrcreelease message, an rrcreelease with suspend config message, or other RRC messages having the same function but not standardized by 3GPP, the terminal may start the second timer.

It is to be understood that the situations of turning on the second timer described in the above embodiments may include a plurality of situations, and the following exemplarily shows two situations:

the first condition is as follows: and when the terminal carries out SDT, the terminal receives the first RRC response message, stops the first timer and starts the second timer. Illustratively, first, when the terminal has an SDT requirement, an RRC connection recovery procedure for SDT is initiated, and a first timer is started. Then, when the second timer is overtime but the first timer is in the running state, the terminal does not trigger the RNAU and continues SDT. And finally, the terminal receives the first RRC response message, considers that the SDT is successful, stops the first timer and keeps in a non-RRC connection state, and the terminal receives the first RRC response message and starts the second timer so as to continuously and periodically trigger the RNAU subsequently.

Case two: when the terminal performs the SDT, the terminal receives a fifth RRC response message, stops the first timer, subsequently receives the first RRC response message, and then starts the second timer, where the fifth RRC response message is, for example, an rrcreesume message, an RRCSetup message, or another RRC message having the same function but not standardized by 3 GPP. Illustratively, first, when the terminal has an SDT requirement, an RRC connection recovery procedure for the SDT is initiated, and a first timer is started. Then, when the second timer is overtime but the first timer is in the running state, the terminal does not trigger the RNAU and continues SDT. Next, the terminal receives the fifth RRC response message, considers that the SDT is successful, stops the first timer, and may enter an RRC CONNECTED state from a non-RRC CONNECTED state. The subsequent terminal receives the first RRC response message, enters a non-RRC CONNECTED state from the RRC CONNECTED state, and starts a second timer so that the subsequent terminal can continue to periodically trigger the RNAU.

In a possible implementation manner, the terminal receives the RRC reject message, and if the second timer is not running, the terminal may set the first variable to the first value, which is similar to fig. 14 in a specific example, except that the timeout of the second timer in fig. 14 needs to be replaced by stopping the second timer, and the description of stopping the second timer may be referred to in fig. 19.

In a possible implementation manner, the terminal receives the RRC reject message, and if the second timer is not running, the terminal may directly perform an RRC connection recovery procedure for the RNAU, which is similar to fig. 14, except that S604 may be changed to: if the second timer is not running, the RRC connection recovery procedure for the RNAU is executed, and in fig. 14, if the second timer is overtime, the second timer needs to be replaced by the second timer, and the description of the second timer stopping can be referred to above in fig. 19.

In a possible implementation manner, the terminal receives the RRC reject message, if the second timer is not running, the terminal may start a third timer, and when the third timer expires, if the first timer is not running, the terminal performs an RRC connection recovery procedure for the RNAU, which is similar to fig. 14 with the difference that S604 may be changed to: if the second timer is not running, starting a third timer, and after S604, the method further includes: when the third timer expires, if the first timer is not running, the terminal performs an RRC connection recovery procedure for the RNAU, and in fig. 14, the second timer needs to be replaced with the second timer to stop when the second timer expires, and the description of stopping the second timer may refer to fig. 19.

In a possible implementation manner, when the first timer expires and if the second timer does not run, the terminal may set the first variable to the first value, which is similar to fig. 15, except that the second timer expires and needs to be replaced by stopping the second timer in fig. 15, and the description of stopping the second timer may refer to fig. 19.

In a possible implementation manner, when the first timer expires and if the second timer is not running, the terminal may directly perform an RRC connection recovery procedure for the RNAU, which is similar to that in fig. 15, except that S703 may be changed to: when the first timer expires, if the second timer is not running, the RRC connection recovery procedure for the RNAU is executed, and in fig. 15, if the second timer expires, the second timer needs to be replaced with the second timer to stop, and the description of stopping the second timer may refer to fig. 19.

In a possible implementation manner, when the first timer expires and if the second timer is not running, the terminal may start a third timer, and when the third timer expires and if the first timer is not running, the terminal performs an RRC connection recovery procedure for the RNAU, which is similar to fig. 15, except that S703 may be changed to: when the first timer is overtime, if the second timer is not running, the third timer is started, and after S703, the method further includes: when the third timer is overtime, if the first timer is not running, the terminal executes the RRC connection recovery procedure for the RNAU, and in fig. 15, if the second timer is overtime, the second timer needs to be replaced by the second timer to stop, and the description of stopping the second timer can be referred to fig. 19.

In a possible implementation manner, when receiving SIB1 of the second serving cell, if the second serving cell belongs to the configured RNA and the second timer is not running, the terminal may set the first variable to the first value, which is similar to fig. 16, except that the expiration of the second timer in fig. 16 needs to be replaced by stopping the second timer, and the description of stopping the second timer may refer to fig. 19.

In one possible implementation manner, when receiving SIB1 of the second serving cell, if the second serving cell belongs to the configured RNA and the second timer is not running, the terminal may directly perform an RRC connection recovery procedure for RNAU, which is similar to fig. 15 with the difference that S804 may be changed to: if the second serving cell belongs to the configured RNA and the second timer is not running, the RRC connection recovery procedure for the RNAU is performed, and if the second timer expires, the second timer is stopped in fig. 16, and the description of stopping the second timer can be referred to in fig. 19.

In a possible implementation manner, when receiving SIB1 of the second serving cell, if the second serving cell belongs to the configured RNA and the second timer is not running, the terminal starts the third timer, which is similar to fig. 16, except that S804 may be changed to: if the second serving cell belongs to the configured RNA and the second timer is not running, starting a third timer, and after S804, the method further includes: when the third timer expires, if the first timer is not running, the terminal performs an RRC connection recovery procedure for the RNAU, and in fig. 16, the second timer needs to be replaced with the second timer to stop when the second timer expires, and the description of stopping the second timer may refer to fig. 19.

In a possible implementation manner, when the integrity check of the terminal fails, if the second timer is not running, the terminal may set the first variable to the first value, which is similar to fig. 17 in a specific example, except that the timeout of the second timer in fig. 17 needs to be replaced by the stop of the second timer, and the description of the stop of the second timer may refer to fig. 19 above.

In a possible implementation manner, when the integrity check of the terminal fails, if the second timer is not running, the terminal may directly perform an RRC connection recovery procedure for the RNAU, which is similar to fig. 17, except that S903 may be changed to: when the integrity check fails and the second timer is not running, the RRC connection recovery procedure for the RNAU is performed, and the expiration of the second timer in fig. 17 needs to be replaced by stopping the second timer, which is described with reference to fig. 19.

In a possible implementation manner, when the integrity check of the terminal fails, if the second timer is not running, the terminal may start a third timer, which is similar to fig. 17, except that S903 may be changed to: when the integrity check fails and the second timer is not running, starting a third timer, and after S903, the method further includes: when the third timer is overtime, if the first timer is not running, the terminal executes the RRC connection recovery procedure for the RNAU, and in fig. 17, if the second timer is overtime, the second timer needs to be replaced by the second timer to stop, and the description of stopping the second timer can be referred to fig. 19.

In one possible implementation, after the terminal sets the first variable to the first value in the SDT procedure, if the access barring is mitigated and the non-access NAS layer does not request the RRC layer to perform RRC connection recovery, the terminal may perform an RRC connection recovery procedure for the RNAU if the first variable is the first value.

It is to be understood that the SDT procedure in this application (e.g., the SDT procedure shown in fig. 5-10 above) may include the RRC connection recovery procedure for SDT described above, optionally, where the resumecuse IE in the transmitted RRC request message is mo-data. An RNAU in this application (e.g., the implementation of performing an RNAU described above) may include the RRC connection recovery procedure described above for the RNAU, optionally where the resumecuse IE in the transmitted RRC request message is an rna-Update.

Without being limited to the above list, in other embodiments, the RNAU may be executed in the RRC IDLE state, and the specific implementation is similar to that of the UE in the RRC INACTIVE state, except that the description may be different, for example, the RRC connection recovery procedure for the RNAU may be replaced by the RRC connection establishment procedure for the RNAU.

Not limited to SIB1 in the above example, in other embodiments, the terminal may receive another message, determine whether the serving cell belongs to the configured RNA according to the message, for example, read a cell identifier from the message, determine whether the read cell identifier belongs to a cell identifier included in a cell list configured by the base station for the UE in the RAN-notifiationinformation IE, for example, read a TAC of the cell from the message, and determine whether the read TAC belongs to a TAC included in a RAN area list configured by the base station for the UE in the RAN-notifiationinformation IE. The present application does not limit the manner of determining whether the serving cell belongs to the configured RNA.

In some embodiments, a UE in the RRCINACTIVE state needs to trigger the RRC connection recovery procedure for RNAU after a T380 timeout or a cell outside the UE's current RNA receives SIB 1. However, the UE that is performing SDT data transmission does not actually need to perform RNAU because the network setup can know the cell location of the UE. Therefore, triggering of RNAU during SDT should be avoided.

In some embodiments, T380 is stopped during SDT. For example, after the SDT procedure starts, the UE stops T380 upon receiving a first response message from the network device corresponding to the UE's RRC request message. For example, the UE stops T380 upon receiving a contention resolution MAC CE for the RA-SDT, or upon receiving an ACK in response to a RRCRESUMeRequest sent over the CG-SDT.

In some embodiments, an additional condition is introduced that the RNAU is triggered if T380 times out only if the SDT failure detection timer is not running, i.e. the first timer is not running. The SDT failure detection timer is started when the UE initiates an RRC connection recovery procedure for SDT, that is, when the SDT failure detection timer runs, the UE is performing an SDT procedure. Thus, to avoid T380 timeout triggered periodic RNAUs, an additional condition may be added to the condition currently triggering the periodic RNAU.

It is to be understood that the communication system architecture and the service scenario described in the present application are for more clearly illustrating the technical solution of the present application, and do not constitute a limitation to the technical solution provided in the present application, and it is known by those skilled in the art that as the communication system architecture evolves and a new service scenario appears, the technical solution provided in the present application is also applicable to similar technical problems.

One of ordinary skill in the art will appreciate that all or part of the processes in the methods of the above embodiments can be implemented by hardware associated with a computer program that can be stored in a computer-readable storage medium, and when executed, can include the processes of the above method embodiments. And the aforementioned storage medium includes: various media that can store computer program code, such as a read-only memory (ROM) or a Random Access Memory (RAM), magnetic or optical disk, and the like.

Claims (16)

1. A method for controlling transmission, applied to a terminal in a non-radio resource control, RRC, connected state, the method comprising:

when a first preset condition is met, executing an RRC connection recovery process for updating an RNAU based on a notification area of a radio access network; wherein the content of the first and second substances,

the first preset condition comprises that the second timer is overtime and the first timer is not running; or the like, or, alternatively,

the first preset condition comprises that the terminal receives a system information block SIB1 of a first service cell, the first service cell does not belong to a configured notification area RNA based on a radio access network, and the first timer is not operated;

the first timer is started when the terminal initiates an RRC connection recovery process for packet data transmission (SDT), and the second timer is started when the terminal receives an RRC release message comprising the duration of the second timer.

2. The method of claim 1, wherein the method further comprises:

when the first timer runs, if an RRC reject message is received, stopping the first timer;

if the second timer is not running, setting a first variable to a first value, the first variable being the first value indicating that there is a pending RNA update procedure.

3. The method of claim 1, wherein the method further comprises:

when the first timer runs, if an RRC reject message is received, stopping the first timer;

and if the second timer is not operated, executing the RRC connection recovery process for the RNAU.

4. The method of claim 1, wherein the method further comprises:

when the first timer runs, if an RRC reject message is received, stopping the first timer;

if the second timer does not run, starting a third timer;

and when the third timer is overtime, if the first timer is not operated, executing the RRC connection recovery process for the RNAU.

5. The method of claim 1, wherein the method further comprises:

when the first timer is overtime, if the second timer is not running, setting a first variable to a first value, wherein the first variable is the first value and indicates that the pending RNA updating process exists.

6. The method of claim 1, wherein the method further comprises:

and when the first timer is overtime, if the second timer is not operated, executing the RRC connection recovery process for the RNAU.

7. The method of claim 1, wherein the method further comprises:

when the first timer is overtime, if the second timer is not operated, a third timer is started;

and when the third timer is overtime, if the first timer is not operated, executing the RRC connection recovery process for the RNAU.

8. The method according to any of claims 5-7 wherein the non-radio resource control, RRC, connected state is an RRC inactive state; and after the first timer is overtime, the terminal is in the RRC non-activated state.

9. The method of claim 1, wherein the method further comprises:

when the first timer runs, if cell reselection occurs, stopping the first timer;

receiving SIB1 of a second serving cell, wherein the second serving cell is a serving cell after cell reselection of the terminal;

when receiving the SIB1 of the second serving cell, if the second serving cell belongs to the configured RNA and the second timer is not running, setting a first variable to a first value, where the first variable indicates that there is a pending RNA update procedure for the first value.

10. The method of claim 1, wherein the method further comprises:

when the first timer runs, if cell reselection occurs, stopping the first timer;

receiving SIB1 of a second serving cell, wherein the second serving cell is a serving cell after cell reselection of the terminal;

when receiving the SIB1 of the second serving cell, if the second serving cell belongs to the configured RNA and the second timer is not running, performing the RRC connection recovery procedure for the RNAU.

11. The method of claim 1, wherein the method further comprises:

when the first timer runs, if cell reselection occurs, stopping the first timer;

receiving SIB1 of a second serving cell, wherein the second serving cell is a serving cell after cell reselection of the terminal;

when receiving the SIB1 of the second serving cell, if the second serving cell belongs to the configured RNA and the second timer is not running, starting a third timer;

and when the third timer is overtime, if the first timer is not operated, executing the RRC connection recovery process for the RNAU.

12. The method according to any of claims 9-11, wherein the non-radio resource control, RRC, connected state is an RRC inactive state; and after the terminal performs cell reselection, the terminal is in the RRC non-activated state.

13. The method of claim 2, 5 or 9, wherein after the setting the first variable to the first value, the method further comprises:

and if the access barring is alleviated and the non-access NAS layer does not request the RRC layer to perform RRC connection recovery, if the first variable is the first value, performing the RRC connection recovery process for the RNAU.

14. The method according to any of claims 1-13 wherein the non-radio resource control, RRC, connected state is an RRC inactive state.

15. A terminal, characterized in that it comprises a transceiver, a processor and a memory for storing a computer program, which the processor invokes for performing the method according to any of claims 1-14.

16. A computer storage medium, characterized in that it stores a computer program which, when executed by a processor, implements the method of any one of claims 1-14.

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