Data transmission method and related device

Abstract

An embodiment of the present application provides a data transmission method, which is applied to a terminal. The terminal is in a non-connected state. The method includes: the terminal obtains a first data packet, and the first data packet is a small packet of data; the terminal and a network device perform a small packet data transmission process; the small packet data transmission process includes the terminal sending a random access preamble, the first data packet, and a radio resource control (RRC) request message to the network device, and the terminal receiving an RRC response message sent by the network device; during the small packet data transmission process, the terminal obtains a second data packet; if the second data packet is a small packet of data, the terminal sends a first scheduling request (SR) to the network device, and the first SR is used to request scheduling resources; the terminal receives first transmission resources scheduled by the network device in response to the first SR; the terminal uses the first transmission resources to send the second data packet to the network device. By adopting the embodiment of the present application, the transmission delay of the second data packet can be reduced without affecting the transmission of the first data packet.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a data transmission method and related devices. Background Art

[0002] In a communication system, the communication protocol stack between a terminal and a network device may include a radio resource control (RRC) layer. Currently, there are three RRC states of a terminal, namely, RRC idle (RRC IDLE) state, RRC inactive (RRC INACTIVE) state, and RRC connected (RRC CONNECTED) state.

[0003] Generally, when the terminal is in the RRC CONNECTED state, data can be transmitted between the terminal and the network device. However, in some scenarios, the data packets to be transmitted by a terminal in the RRC IDLE state or the RRC INACTIVE state are very small, and such data packets can be called small data, such as instant messaging messages, heartbeat packets, periodic data, etc. Moreover, the signaling required for the terminal to enter the RRC CONNECTED state from the RRC IDLE state or the RRC INACTIVE state is even greater than the small data, resulting in unnecessary power consumption and signaling overhead of the terminal. To avoid the above situation, a terminal in the RRC IDLE state or the RRC INACTIVE state can transmit small data during the random access (RA) process without having to enter the RRC CONNECTED state to transmit the small data. The above transmission process can be referred to as small data transmission (SDT).

[0004] However, when performing SDT, the terminal may obtain new data packets to be transmitted. At this time, the terminal may trigger reporting a buffer status report (BSR) to the network device, but there may be no transmission resources for reporting the BSR. Then the terminal may trigger reporting a scheduling request (SR) to the network device. However, the network device usually only allocates SR resources to terminals in the RRC CONNECTED state. Therefore, the terminal performing SDT has no transmission resources for reporting the SR. At this time, the terminal can only initiate a new RA or SDT to request scheduling resources from the network device, but this will affect the transmission delay of the currently transmitted small data or the new data packets. For example, if a new RA or SDT is initiated after waiting for the currently ongoing SDT to end, the transmission delay of the new data packets will be relatively large. Or, if the currently ongoing SDT is stopped and a new RA or SDT is directly initiated, the transmission delay of the currently transmitted small data will be relatively large. Summary of the Invention

[0005] Embodiments of the present application disclose a data transmission method and related apparatus, which can improve the transmission delay of new data packets while not affecting the transmission delay of the currently transmitted small data packets.

[0006] In a first aspect, an embodiment of the present application provides a data transmission method, which is applied to a user equipment terminal. The terminal is in a non-connected state. The method includes: the terminal obtains a first data packet, and the first data packet is a small data packet; the terminal and the network device perform a small data packet transmission process; the small data packet transmission process includes the terminal sending a random access preamble, the first data packet, and a radio resource control (RRC) request message to the network device, and the terminal receiving an RRC response message sent by the network device; during the small data packet transmission process, the terminal obtains a second data packet; if the second data packet is a small data packet, the terminal sends a first scheduling request (SR) to the network device, and the first SR is used to request scheduling resources; the terminal receives first transmission resources scheduled by the network device in response to the first SR; the terminal uses the first transmission resources to send the second data packet to the network device.

[0007] Among them, the small packet data is a data packet with a data volume smaller than a preset threshold (such as the size of a transport block indicated by the base station), or a data packet with a data label of small packet data, or a data packet whose data type belongs to small packet data, etc. The data packet that is not small packet data can be called large packet data, which can be a data packet with a data volume greater than or equal to the preset threshold, or a data packet with a data label of large packet data, or a data packet whose data type belongs to large packet data, etc. For example, the data with the data type of heartbeat packet is small packet data, and the data with the data types of file, video or audio is large packet data. The small packet data is, for example, an instant messaging message, a heartbeat packet, periodic data, etc.

[0008] Optionally, the process of the terminal and the network device performing small packet data transmission may be replaced with: the terminal sends a random access preamble for transmitting small packet data or the first data packet to the network device. Optionally, the second data packet is obtained by the terminal when the terminal sends the random access preamble to the network device, or is obtained by the terminal after the terminal sends the random access preamble to the network device.

[0009] In the embodiment of the present application, during the process of the terminal and the network device performing small packet data transmission, the terminal generates a second data packet, and the terminal can timely notify the network device of the arrival of new small packet data through a first SR. In response to the first SR, the network device can dynamically schedule a first transmission resource for the terminal, so that the terminal uses the first transmission resource to send the second data packet. Therefore, the terminal can continue to transmit new small packet data in the non-connected state without initiating a new RA or SDT, avoiding unnecessary signaling overhead and power consumption. At the same time, the transmission delay of the second data packet can be reduced without affecting the transmission delay of the first data packet.

[0010] In a possible implementation manner, the first SR is used to request scheduling resources for the small packet data, and the method further includes: if the second data packet is large packet data, the terminal sends a second SR to the network device, and the second SR is used to request scheduling resources for the large packet data, and the RRC response message in the small packet data transmission process is sent by the network device in response to the second SR; the terminal enters the RRC connected state in response to the RRC response message; the terminal sends the second data packet to the network device.

[0011] In the embodiments of the present application, during the process of the terminal and the network device performing small packet data transmission, the terminal generates a second data packet, and the terminal can timely notify the network device of the arrival of new large packet data through the second SR. In response to the second SR, the network device can instruct the terminal to enter the RRC connected state, so that the terminal sends the second data packet in the RRC connected state. The terminal does not need to initiate a new RA or SDT, saving transmission resources and avoiding unnecessary signaling overhead and power consumption. At the same time, the transmission delay of the second data packet can be reduced without affecting the transmission delay of the first data packet.

[0012] In a possible implementation manner, the method further includes: if the second data packet is large packet data, the terminal performs a random access process; the terminal enters the RRC connected state based on the random access process; the terminal sends the second data packet to the network device.

[0013] In a possible implementation manner, the terminal and the network device performing the random access process includes: the terminal interrupts the small packet data transmission process and performs the random access process; after the terminal enters the RRC connected state based on the random access process, the method further includes: the terminal sends the first data packet to the network device.

[0014] In the embodiments of the present application, during the process of the terminal and the network device performing small packet data transmission, the terminal generates new large packet data, and the terminal can interrupt the small packet data process and perform a random access process to request to enter the RRC connected state. After the terminal enters the connected state, it then transmits the small packet data (i.e., the first data packet) and the new large packet data (i.e., the second data packet), avoiding affecting the transmission delay of the large packet data.

[0015] In a possible implementation manner, the method further includes: in a case where the terminal does not have resources to send a BSR to the network device, the terminal triggers reporting the first SR or the second SR.

[0016] In the embodiments of the present application, during the process of the terminal and the network device performing small packet data transmission, the terminal generates a second data packet, and the terminal can trigger reporting a BSR. If there are no resources to report a BSR, the terminal can trigger reporting an SR. If the first SR and / or the second SR are configured, the terminal can timely notify the network device of the arrival of new data packets through the first SR and / or the second SR, thereby reducing the transmission delay of the second data packet without affecting the transmission delay of the first data packet. If the second data packet is large packet data and the second SR is not configured, the terminal can perform a random access process to enter the RRC connected state to transmit the new large packet data, reducing the transmission delay of the second data packet.

[0017] In a possible implementation, when the terminal and the network device perform the small packet data transmission process, the terminal restores the data radio bearer (DRB) for transmitting small packet data and the DRB for transmitting large packet data.

[0018] In a possible implementation, the logical channel corresponding to the first SR is the logical channel included in the first DRB, the first DRB is the DRB for transmitting small packet data, the logical channel corresponding to the second SR is the logical channel included in the second DRB, and the second DRB is the DRB for transmitting large packet data.

[0019] In a possible implementation, when the terminal sends the first SR to the network device, the terminal maintains uplink synchronization; and / or when the terminal sends the second SR to the network device, the terminal maintains uplink synchronization.

[0020] In the embodiments of the present application, during the small packet data transmission process between the terminal and the network device, the terminal generates a second data packet. The terminal can timely notify the network device of the arrival of a new data packet through the first SR and / or the second SR while maintaining uplink synchronization, thereby reducing multipath interference and improving the transmission quality.

[0021] In a possible implementation, before the terminal and the network device perform the small packet data transmission process, the method further includes: the terminal receives a configuration message sent by the network device, the configuration message includes information about the first SR and the second SR; the terminal determines that the information about the first SR and the second SR becomes effective; or, before the terminal and the network device perform the small packet data transmission process, the method further includes: the terminal receives a configuration message sent by the network device, the configuration message includes information about the first SR and the second SR; the terminal receives an effective message sent by the network device, the effective message is used to indicate that the information about the first SR and the second SR becomes effective; wherein, the information about the first SR and the second SR includes the configuration information of the first SR and the second SR, and the resource information of the first SR and the second SR.

[0022] In the embodiments of the present application, the manner in which the network device indicates the effectiveness of the configuration information of the first SR and the second SR to the terminal is relatively flexible. The network device can flexibly select the manner of indicating the effectiveness of the above configuration information according to the network situation, and the application scenario is more extensive.

[0023] In a possible implementation, the method further includes: when a preset condition is satisfied, the terminal releases the configuration information of the first SR and the second SR, and / or the resource information of the first SR and the second SR; the preset condition includes at least one of the following: the terminal performs cell reselection, the terminal fails to maintain uplink synchronization, the terminal receives an RRC response message sent by the network device, and the RRC response message is used to indicate any one of the following: the terminal enters the RRC connected state, and the small packet data transmission process ends.

[0024] In the embodiments of the present application, the terminal can choose whether to release the configuration information and / or resource information of the first SR and the second SR according to the actual situation and requirements, so as to avoid unnecessary power consumption.

[0025] In a possible implementation, the capability information of the first SR and the second SR is obtained by the network device from the network device to which the terminal was previously connected.

[0026] In the embodiments of the present application, even if the network device to which the terminal is connected is switched, the network device newly connected to the terminal can obtain the configuration information of the first SR and the second SR of the terminal from the network device to which the terminal was previously connected, which is convenient for the network device newly connected to the terminal to configure the first SR and the second SR for the terminal. Therefore, the terminal configured with the first SR and the second SR can choose to use the first SR and the second SR to notify the network device that a new data packet has arrived according to the actual situation, thereby reducing the data transmission delay.

[0027] In a possible implementation, the method further includes: the terminal determines a first beam, and the terminal determines the first SR according to the first beam; the first beam is the beam for the terminal to send the first SR to the network device, or the beam corresponding to the first SR, and the network device is used to determine a second beam according to the first SR after receiving the first SR, and the second beam is the beam for the network device to send downlink data to the terminal; or, the terminal determines a first beam, and the terminal determines the second SR according to the first beam; the first beam is the beam for the terminal to send the second SR to the network device, or the beam corresponding to the second SR; the network device is used to determine a second beam according to the second SR after receiving the second SR, and the second beam is the beam for the network device to send downlink data to the terminal.

[0028] In the embodiments of the present application, the network device can complete beam update through the first SR, improving the subsequent transmission quality.

[0029] Second aspect, an embodiment of the present application provides another data transmission method, which is applied to a user equipment terminal. The terminal is in a non-connected state. The method includes: the terminal obtains a first data packet; the first data packet is a small packet of data; the terminal and a network device perform a small packet data transmission process; the small packet data transmission process includes the terminal sending a random access preamble, the first data packet, and an RRC request message to the network device, and the terminal receiving an RRC response message sent by the network device; during the small packet data transmission process, the terminal obtains a second data packet; when the second data packet is a small packet of data, the terminal sends a first BSR to the network device to obtain a first transmission resource scheduled by the network device in response to the first BSR; the terminal uses the first transmission resource to send the second data packet to the network device.

[0030] In an embodiment of the present application, during the small packet data transmission process between the terminal and the network device, the terminal generates a second data packet, and the terminal can trigger the reporting of the BSR. The terminal can timely notify the network device of the arrival of new small packet data through the BSR. The network device can dynamically schedule a first transmission resource for the terminal, so that the terminal uses the first transmission resource to send a new data packet, and the terminal can continue to transmit small packet data in the non-connected state. The terminal does not need to initiate a new RA or SDT, saving transmission resources and avoiding unnecessary signaling overhead and power consumption. Without affecting the transmission delay of the first data packet, the transmission delay of the second data packet is reduced.

[0031] In a possible implementation manner, the method further includes: when the second data packet is a large packet of data, the terminal sends a second BSR to the network device, and the terminal receives an RRC response message sent by the network device in response to the second BSR; the terminal enters the RRC connected state in response to the RRC response message, and the terminal sends the second data packet to the network device.

[0032] In a possible implementation manner, the above-mentioned when the second data packet is a small packet of data, the terminal sends a first BSR to the network device to obtain a first transmission resource scheduled by the network device in response to the first BSR; the terminal uses the first transmission resource to send the second data packet to the network device can be replaced by: when the second data packet is a large packet of data, the terminal sends a second BSR to the network device, and the terminal receives an RRC response message sent by the network device in response to the second BSR; the terminal enters the RRC connected state in response to the RRC response message, and the terminal sends the second data packet to the network device.

[0033] In a possible implementation, the first BSR includes a first field indicating a transmission resource for obtaining small packet data, and the first BSR includes a second field indicating a transmission resource for obtaining large packet data.

[0034] In a possible implementation, the first field indicates a first logical channel group, and the first logical channel group includes a logical channel for transmitting small packet data. The second field indicates a second logical channel group, and the second logical channel group includes a logical channel for transmitting large packet data.

[0035] Optionally, when the value of the first field is a first value, it indicates that there is small packet data to be transmitted. When the value of the first field is a second value, it indicates that there is no small packet data to be transmitted. When the value of the second field is a first value, it indicates that there is large packet data to be transmitted. When the value of the second field is a second value, it indicates that there is no large packet data to be transmitted.

[0036] In the embodiments of the present application, the manner in which the BSR indicates the existence of small packet data or large packet data to be transmitted is relatively flexible, and the application scenarios are more extensive.

[0037] In a third aspect, the embodiments of the present application provide another data transmission method, which is applied to a user equipment terminal in a non-connected state. The method includes: the terminal obtains a first data packet, and the first data packet is small packet data; the terminal sends a random access preamble to a network device; the terminal obtains a second data packet; the terminal sends a third data packet, an RRC request message, and a first indication information to the network device, and the first indication information is used to request scheduling resources; the third data packet is the data packet with a higher priority among the first data packet and the second data packet; the terminal receives first transmission resources scheduled by the network device in response to the first indication information for the terminal; the terminal uses the first transmission resources to send the second data packet to the network device.

[0038] In the embodiments of the present application, during the process of small packet data transmission between the terminal and the network device, the terminal generates a second data packet. The terminal can send the third data packet with a higher priority during the current small packet data transmission process, and timely notify the network device of the arrival of new small packet data through the first indication information, which not only avoids the low-priority data packet affecting the transmission of the high-priority data packet, but also reduces the transmission delay of the low-priority data packet. Moreover, the terminal can continue to transmit low-priority small packet data in the non-connected state without initiating a new RA or SDT, avoiding unnecessary signaling overhead and power consumption.

[0039] In a possible implementation, the priority of the terminal to send the third data packet is higher than the priority of the terminal to send the BSR. The terminal sends a third data packet, an RRC request message, and a first indication message to the network device, including: when the terminal does not have resources to send the BSR to the network device, the terminal sends the third data packet, the RRC request message, and the first indication message to the network device.

[0040] In a fourth aspect, an embodiment of the present application provides a data transmission method applied to a network device. The method includes: the network device and a terminal in a non-connected state perform a small packet data transmission process; the small packet data transmission process includes the network device receiving a random access preamble, a first data packet, and an RRC request message sent by the terminal, and the network device sending an RRC response message to the terminal; the first data packet is small packet data obtained by the terminal; the network device receives a first SR sent by the terminal, where the first SR is sent by the terminal when a second data packet is small packet data, and the second data packet is obtained by the terminal during the small packet data transmission process; the network device schedules first transmission resources for the terminal in response to the first SR; the network device receives the second data packet sent by the terminal using the first transmission resources.

[0041] In a possible implementation, the method further includes: the network device receives a second SR sent by the terminal, where the second SR is sent by the terminal when the second data packet is large packet data; the RRC response message in the small packet data transmission process is sent by the network device in response to the second SR, and the RRC response message is used to instruct the terminal to enter the RRC connected state; the network device receives the second data packet sent by the terminal in the RRC connected state.

[0042] In a possible implementation, the method further includes: the network device receives the second data packet sent by the terminal in the RRC connected state, and the RRC connected state is entered by the terminal through a random access process when the second data packet is large packet data.

[0043] In a possible implementation, when the terminal and the network device perform the small packet data transmission process, the terminal restores a data radio bearer DRB for transmitting small packet data and a DRB for transmitting large packet data.

[0044] In a possible implementation, the logical channel corresponding to the first SR is the logical channel included in the first DRB, the first DRB is a DRB for transmitting small packet data, the logical channel corresponding to the second SR is the logical channel included in the second DRB, and the second DRB is a DRB for transmitting large packet data.

[0045] In a possible implementation, the capability information of the first SR and the second SR is obtained by the network device from the network device to which the terminal was previously connected. In a possible implementation, the first SR is determined by the terminal according to a first beam, where the first beam is the beam for the terminal to send the first SR to the network device, or the beam corresponding to the first SR. The method further includes: after receiving the first SR, the network device determines a second beam according to the first SR, and the second beam is the beam for the network device to send downlink data to the terminal; or,

[0046] The second SR is determined by the terminal according to a first beam, where the first beam is the beam for the terminal to send the second SR to the network device, or the beam corresponding to the second SR. The method further includes: after receiving the second SR, the network device determines a second beam according to the second SR, and the second beam is the beam for the network device to send downlink data to the terminal.

[0047] In a fifth aspect, an embodiment of the present application provides a data transmission method applied to a network device. The method includes: the network device performs a small packet data transmission process with a terminal in a non-connected state; the small packet data transmission process includes the network device receiving a random access preamble, a first data packet, and an RRC request message sent by the terminal, and the network device sending an RRC response message to the terminal; the first data packet is the small packet data obtained by the terminal; the network device receives a first BSR sent by the terminal, where the first BSR is sent by the terminal when the second data packet is small packet data, and the second data packet is obtained by the terminal during the small packet data transmission process; the network device schedules a first transmission resource for the terminal in response to the first BSR; and the network device receives the second data packet sent by the terminal using the first transmission resource.

[0048] In a possible implementation, the first BSR includes a first field indicating a transmission resource for obtaining small packet data, and the first BSR includes a second field indicating a transmission resource for obtaining large packet data.

[0049] In a possible implementation, the first field indicates a first logical channel group, the first logical channel group includes logical channels for transmitting small packet data, the second field indicates a second logical channel group, and the second logical channel group includes logical channels for transmitting large packet data.

[0050] In a sixth aspect, an embodiment of the present application provides a data transmission method applied to a network device. The method includes: the network device receives a random access preamble sent by the terminal, the random access preamble is sent after the terminal obtains a first data packet, and the first data packet is small packet data; the network device receives a third data packet, an RRC request message, and first indication information sent by the terminal, the first indication information is sent after the terminal obtains a second data packet, and the second data packet is small packet data obtained by the terminal when or after sending the random access preamble to the network device; the third data packet is the data packet with a higher priority among the first data packet and the second data packet; the network device schedules first transmission resources for the terminal in response to the first indication information; the network device receives the second data packet sent by the terminal using the first transmission resources.

[0051] In a possible implementation, the priority of the terminal sending the third data packet is higher than the priority of the terminal sending the BSR, and the first indication information is sent by the terminal without sending the BSR to the network device.

[0052] In a seventh aspect, an embodiment of the present application provides a user equipment terminal, including a transceiver, a processor, and a memory; the memory is used to store computer program code, the computer program code includes computer instructions, and the processor calls the computer instructions to enable the user equipment to execute the data transmission methods provided in the first aspect to the third aspect, and any implementation manner of the first aspect to the third aspect of the embodiments of the present application.

[0053] In an eighth aspect, an embodiment of the present application provides a network device, including a transceiver, a processor, and a memory; the memory is used to store computer program code, the computer program code includes computer instructions, and the processor calls the computer instructions to enable the network device to execute the data transmission methods provided in the fourth aspect to the sixth aspect, and any implementation manner of the fourth aspect to the sixth aspect of the embodiments of the present application.

[0054] In a ninth aspect, an embodiment of the present application provides a computer storage medium storing a computer program including program instructions. When the program instructions are executed by a processor, they are used to execute the data transmission methods provided in the first to sixth aspects of the embodiments of the present application and any implementation manners of the first to sixth aspects.

[0055] In a tenth aspect, an embodiment of the present application provides a computer program product. When the computer program product runs on a communication device, it causes the communication device to execute the data transmission methods provided in the first to sixth aspects of the embodiments of the present application and any implementation manners of the first to sixth aspects.

[0056] In an eleventh aspect, an embodiment of the present application provides an electronic device including a method or device described in any embodiment of the present application. The above-mentioned electronic device is, for example, a chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The following introduces the drawings used in the embodiments of the present application.

[0058] Figure 1 is a schematic diagram of the architecture of a communication system provided by an embodiment of the present application;

[0059] Figure 2 is a schematic diagram of the architecture of the user plane communication protocol stack of a New Radio (NR) access;

[0060] Figure 3 is a schematic diagram of the architecture of the control plane communication protocol stack of an NR;

[0061] Figure 4 is a schematic diagram of the transition of the Radio Resource Control (RRC) state of a User Equipment (UE);

[0062] Figures 5 - 8 is a schematic diagram of the process of some Small Data Transmission (SDT) provided by an embodiment of the present application;

[0063] Figure 9 is a schematic diagram of a Data Radio Bearer (DRB) provided by an embodiment of the present application;

[0064] Figures 10 - 18 is a schematic diagram of the process of some data transmission methods provided by an embodiment of the present application;

[0065] Figures 19 - 20 is a schematic diagram of the process of some methods for obtaining the capability information of a UE provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0066] The embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.

[0067] In the embodiments of the present application, a network device may be a device for sending or receiving information. Optionally, the network device is an access network device. For example but not limited to: a base station, a user equipment (UE), a wireless access point (AP), a transmission and receiver point (TRP), a relay device, or other network devices with the functions of a base station, etc. Among them, a base station is a device deployed in a radio access network (RAN) for providing wireless communication functions. In different wireless access systems, the name of the base station may be different. For example but not limited to, a base transceiver station (BTS) in a global system for mobile communications (GSM) or code division multiple access (CDMA), a node B (NB) in wideband code division multiple access (WCDMA), an evolved node B (eNodeB) in long term evolution (LTE), and may also be a next-generation base station (g node B, gNB) in the 5th generation mobile networks (5G), i.e., new radio (NR), or a base station in other future network systems.

[0068] In the embodiments of the present application, a terminal may be a device with wireless communication functions. Optionally, the terminal is a UE. In some scenarios, the terminal may also be referred to as a mobile station, an access terminal, a user agent, etc. For example, the terminal is in the form of a handheld device, a wearable device, a computing device, a portable device, or a vehicle-mounted device, etc. For example, the terminal is specifically a device such as a cellular phone, a smartphone, smart glasses, a laptop computer, a personal digital assistant, or a cordless phone. The following embodiments will be described by taking the terminal as a UE as an example.

[0069] In the present application, the UE obtains data packets, can generate data packets for the UE, or can receive data packets for the UE from other devices.

[0070] Please refer to Figure 1 , Figure 1It is a schematic diagram of the architecture of a communication system provided by an embodiment of the present application. The communication system can 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.

[0071] As Figure 1 shown, the communication system may include a core network 110, network devices 120, and UEs 130. Among them, the core network 110 can be connected to at least one network device 120. The network device 120 can provide wireless communication services for at least one UE 130. The UE 130 can be connected to at least one network device 120 through an air interface. The core network 110 is a key control node in this communication system, mainly responsible for signaling processing functions, such as but not limited to functions for implementing access control, mobility management, session management, etc. Optionally, the network device 120 is a base station. At least one base station can form a RAN node. In NR, the core network 110 can be referred to as the 5G Core (5GC) 110, and the network device 120 can be referred to as gNB 120. The NR-RAN node can include at least one gNB 120 connected to the 5GC 110 through the NG interface, and at least one gNB 120 in the NR-RAN node can be connected and communicate through the Xn-C interface. The UE 130 can be connected to the gNB 120 through the Uu interface.

[0072] The core network 110 can send downlink data to the UE 130 through the network device 120, and the UE 130 can also send uplink data to the core network 110 through the connected network device 120. It should be noted that Figure 1 the forms and quantities of the core network 110, network devices 120, and UEs 130 shown are only for illustration, and the embodiments of the present application do not limit this.

[0073] For the convenience of understanding, the embodiments of the present application mainly take the communication system with LTE and / or NR as the application, and the network device as the base station as an example for description. Among them, LTE is relatively mature, and the description of the communication protocol stack of LTE will not be elaborated too much. Next, the communication protocol stack of NR will be mainly described.

[0074] Please refer to Figure 2 , Figure 2It is a schematic diagram of the architecture of the user plane protocol stack of NR. The user plane protocol stack may include a physical (PHY) layer, a medium 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.

[0075] Please refer to Figure 3 , Figure 3 It is a schematic diagram of the architecture of the control plane protocol stack of NR. 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, and a non-access stratum (NAS).

[0076] Such as Figure 2 and Figure 3As shown, the MAC layer can provide services for higher layers (such as the RLC layer) via logical channels (LCH). According to the type of information transmitted, logical channels can be classified into control channels for transmitting control information on the control plane and traffic channels for transmitting user data on the user plane. Among them, control channels can include but are not limited to common control channels (CCCH) and dedicated control channels (DCCH). Traffic channels can include but are not limited to dedicated traffic channels (DTCH). CCCH can always exist, and UEs without an RRC connection to the RAN node can also use CCCH to transmit information. DCCH can be used to transmit dedicated control information between the UE and the RAN node. DTCH can be used to transmit user data between the UE and the RAN node. Generally, DCCH and DTCH do not always exist. Instead, after the base station connected to the UE restores the UE context, DCCH and DTCH can be used for communication between the UE and the base station. Among them, UE context includes but is not limited to the identification of the terminal, radio bearer (RB) - related configurations, security encryption - related configurations, quality - of - service - related configurations, etc. When the base station configures logical channels for the UE, it will simultaneously indicate the logical channel group (LCG) to which the logical channel belongs, that is, the base station knows which LCG each logical channel belongs to.

[0077] RB can be a set of connection formats between the UE and the RAN node, and can include related configurations of physical channels, transport channels, and logical channels. RB can be divided into signaling radio bearers (SRB) for transmitting control information on the control plane and data radio bearers (DRB) for transmitting user data on the user plane. One DRB can include an entity of the PDCP layer (abbreviated as PDCP entity), an entity of the RLC layer (abbreviated as RLC entity), and a logical channel.

[0078] Such as Figure 3As shown, the RRC layer can be used to transmit RRC messages between the UE and the base station. For example but not limited to, the RRC Resume Request in NR can be used by the UE to request the resumption of a suspended RRC connection to transmit data with the base station. The RRC layer belongs to the access stratum (AS). For the RRC layer, there are currently three RRC states of the UE, namely the RRC IDLE state, the RRC INACTIVE state, and the RRC CONNECTED state. When the UE is in different RRC states, most of the operations performed are different. The specific conversion process of these three states can be seen in the following Figure 4 example.

[0079] Compared with the user plane protocol stack of LTE, the user plane protocol stack of NR has added an SDAP layer, but the architectures of other layers are the same, and the specific descriptions are also similar, so they will not be elaborated here. The architectures of the control plane protocol stack of LTE and the control plane protocol stack of NR are the same, and the specific descriptions of each layer are also similar, so they will not be elaborated here.

[0080] It can be understood that the architectures and service scenarios described in this application are for more clearly explaining the technical solutions of this application, and do not constitute a limitation to the technical solutions provided by this application. Those of ordinary skill in the art know that with the evolution of the network architecture and the emergence of new service scenarios, the technical solutions provided by this application are equally applicable to similar technical problems.

[0081] Please refer to Figure 4 , Figure 4 which is a schematic diagram of the conversion of the RRC state of the UE. Specifically, when the UE is in the RRC CONNECTED state, there is an RRC connection between the UE and the base station, so that information such as user data can be sent and received. The NR-RAN and the UE can retain the UE context of the AS layer, and the NG-RAN knows the cell to which the UE belongs. The UE can enter the RRC IDLE state from the RRC CONNECTED state under the indication of the base station. When the UE is in the RRC IDLE state, there is no RRC connection between the UE and the base station. For example, after the UE receives the RRC connection release message sent by the base station, the RRC connection between the UE and the base station will be stopped, and the RAN node will delete the UE context of this UE. When the UE is in the RRC IDLE state, the UE can perform operations such as selection of the public land mobile network (PLMN), cell reselection, acquisition of system information, paging initiated by the 5GC for incoming calls, and discontinuous reception (DRX) configured by the NAS layer for paging by the core network.

[0082] The RRC INACTIVE state is a newly added RRC state in NR. Generally, for UEs with infrequent data transmissions, the base station usually keeps the UE in the RRC INACTIVE state. The UE can also enter the RRC INACTIVE state from the RRC CONNECTED state under the indication of the base station. For example, after the UE receives the RRC connection release message with a suspension indication sent by the base station, the RRC connection between the UE and the base station is suspended, but at least one RAN node retains the UE context of the UE. When the UE is in the RRC INACTIVE state, the UE can perform public land mobile network (PLMN) selection, cell reselection, obtain system information, be paged for an incoming call initiated by the NG-RAN (Paging), manage the RAN-based Notification Area (RNA) by the NG-RAN, and configure the DRX for RAN paging by the NG-RAN, etc. The NR-RAN and the UE can retain the UE context at the AS layer, and the NG-RAN knows the RNA where the UE is located.

[0083] Understandably, compared with entering the RRC CONNECTED state from the RRC IDLE state, the UE can enter the RRC CONNECTED state faster from the RRC INACTIVE state. The UE can also enter the RRC IDLE state from the RRC INACTIVE state under the indication of the base station, and the specific process is similar to the above process of entering the RRC IDLE state from the RRC CONNECTED state.

[0084] To enter the RRC CONNECTED state, a UE in the RRC IDLE state or RRC INACTIVE state can perform random access (RA), or perform RA in response to a paging message from the base station. RA can include 4-step random access (abbreviated as 4step-RA) and 2-step random access (abbreviated as 2step-RA). When the UE is not configured with contention free random access, the UE can initiate 4step-RA or 2step-RA based on the relative magnitude of the currently measured reference signal receiving power (RSRP) and a preset RSRP threshold. For example, when the currently measured RSRP is greater than or equal to the preset RSRP threshold, the UE can initiate 2step-RA. When the currently measured RSRP is less than the preset RSRP threshold, the UE can initiate 4step-RA. Among them, the message sent by the UE to the base station in the third step of 4step-RA can be called message 3, abbreviated as msg3. The message sent by the UE to the base station in the first step of 2step-RA can be called message A, abbreviated as msgA.

[0085] Among them, the above msg3 or msgA can include RRC messages. The RRC message can be different when the UE is in different RRC states and in different service scenarios. For example, when a large amount of data needs to be sent from a UE in the RRC INACTIVE state to the base station, msg3 can include an RRCResumeRequest message to request the resumption of the suspended RRC connection and enter the RRC CONNECTED state to transmit data with the base station. It should be noted that the base station does not indicate the RRC state of the UE only based on the message sent by the UE (such as msg3 or msgA), but also needs to comprehensively consider network conditions such as network congestion, resource scheduling, and resource occupancy to determine the indicated RRC state of the UE.

[0086] A UE in the RRC CONNECTED state needs to maintain uplink synchronization (timing advance, TA) if it wants to send uplink data to the network device. If a UE in the RRC CONNECTED state does not obtain uplink synchronization, the UE can initiate RA to the network device. Among them, when the UE's timing advance timer (TAT) is running, the UE maintains uplink synchronization. When the UE's TAT times out, the UE's uplink synchronization fails.

[0087] When there is no uplink resource but there is uplink data to be sent to the base station, a UE in the RRC CONNECTED state can trigger the reporting of a buffer status report (BSR) to request the base station to schedule uplink resources. The BSR can be used to indicate the amount of data currently waiting to be transmitted in the UE's data buffer. This amount of data can be different at different times. For example, if the UE is a smartphone, the user can send messages to other users through the social applications installed on the UE, but the types and quantities of the messages sent by the user at different times can be different. Sometimes the message sent may be just a text message, and sometimes the message sent may include multiple videos. Therefore, the size of the BSR sent by the UE to the base station can also be different at different times. The resource for the UE to send the BSR (abbreviated as the BSR resource) can be dynamically scheduled by the base station for the UE.

[0088] When the UE also has no BSR resources, the UE can trigger the reporting of a scheduling request (SR). The SR is used by a UE in the RRC CONNECTED state to request the base station to schedule uplink resources. Different from the BSR resource being dynamically scheduled by the base station for the UE, the resource used to transmit the SR (abbreviated as the SR resource) is a series of physical uplink control channel (PUCCH) resources pre-configured by the base station for the UE. Different UEs are configured with different SR resources, and the base station can determine the corresponding UE according to the SR resource used by the UE when reporting the SR. Also, different from the size of the BSR being variable, the size of the SR is usually a fixed 1 bit. The SR is used to indicate that there is data waiting to be transmitted in the UE, but it cannot indicate the specific amount of data.

[0089] When the UE has no BSR resources but has SR resources, the UE can report the SR on the SR resources to the network device so that the base station schedules uplink resources for the UE. Among them, the time to report the SR needs to be within the period configured by the base station for the UE (abbreviated as the SR period). Unless the UE can complete the transmission of the data in the UE's buffer through this uplink resource, otherwise the UE will transmit the BSR through this uplink resource instead of sending newly obtained data packets or data packets with higher priorities. That is to say, when the uplink resources are limited, the priority of the BSR is higher than that of the data packets.

[0090] Among them, each set of SR configurations configured by the network device for the UE can correspond to at least one logical channel. Correspondingly, each logical channel can be mapped to at least one set of SR configurations. Each set of SR configurations can include SR configuration (SchedulingRequestConfig) information and SR resource configuration (SchedulingRequestResourceConfig) information. Among them, the fields included in SchedulingRequestConfig are, for example: SR configuration identity (Identity document, ID) (schedulingRequestId), prohibited SR transmission time (sr-ProhibitTime), maximum number of SR retransmissions (sr-TransMax). The unit of sr-ProhibitTime is milliseconds. After the UE reports the SR, the prohibited timer starts timing. When the timing duration exceeds sr-ProhibitTime, the UE can report the SR again. sr-TransMax indicates the maximum number of times the UE can retransmit the SR. When the prohibited timer times out, the UE can report the SR again. If the number of times the UE reports the SR again is equal to sr-TransMax, the UE can initiate a random access.

[0091] The fields included in SchedulingRequestResourceConfig are, for example: SR resource (resource), SR resource ID (schedulingRequestResourceId), SR configuration ID (schedulingRequestID) using this SR resource, SR period (periodicityAndOffset), priority of the SR resource (phy-PriorityIndex).

[0092] However, if the UE also does not have an SR resource, the UE needs to initiate an RA to the base station to request scheduling resources. Or when the SR configured by the base station fails (such as TAT timeout), the UE needs to initiate an RA to the base station to obtain uplink synchronization.

[0093] Understandably, generally, if a UE in the RRC IDLE state or RRC INACTIVE state has uplink data to send to the base station, or if a UE in the RRC IDLE state or RRC INACTIVE state receives a paging message sent by the base station, and this paging message is used by the base station to indicate that there is downlink data to send to the UE, then the UE needs to perform a random access procedure and enter the RRC CONNECTED state, and then transmit data with the base station in the RRC CONNECTED state. However, the above method is more applicable to the case where the amount of data transmitted between the UE and the base station is large. If the transmitted data packet is very small, such data packets can be called small data. The signaling required for the UE to switch states is even greater than the small data, resulting in unnecessary power consumption and signaling overhead of the UE.

[0094] In the embodiments of the present application, small data may include, but is not limited to, data packets with a data volume smaller than a preset threshold (such as the size of the transport block indicated by the base station), data packets with a data label of small data, data packets with a data type belonging to small data, etc. Data packets that are not small data can be called large data, and may include, but is not limited to, data packets with a data volume greater than or equal to the preset threshold, data packets with a data label of large data, data packets with a data type belonging to large data, etc. Among them, the above data label and / or the above data type can be jointly negotiated by the UE and the network device. For example, the data label may include large data and small data. For example, data with a data type of heartbeat packet is small data, and data with a data type of file, video, or audio is large data. Small data is, for example, instant messaging messages, heartbeat packets, periodic data, etc.

[0095] In the embodiments of the present application, a UE in the RRC IDLE state or RRC INACTIVE state (subsequently collectively referred to as the non-connected state) can transmit small data during the RA process without having to enter the RRC CONNECTED state to transmit small data. The above transmission process can be called small data transmission (SDT) based on RA. RA can include 4step-RA and 2step-RA. Correspondingly, SDT can also include SDT based on 4step-RA (abbreviated as 4step-SDT) and SDT based on 2step-RA (abbreviated as 2step-SDT). An example of 4step-SDT can be specifically seen in the following Figure 5 and Figure 6 , and an example of 2step-SDT can be specifically seen in the following Figure 7 and Figure 8 .

[0096] It should be noted that the DRBs configured by the base station for the UE may include a DRB for carrying small-packet data (abbreviated as SDTDRB) and a DRB for carrying large-packet data (abbreviated as non-SDT DRB (non-SDT DRB)). Only when the small-packet data carried by the SDT DRB arrives can the UE initiate SDT. When the large-packet data carried by the non-SDT DRB arrives, the UE cannot initiate SDT. Next Figures 5 - 8 All the DRBs mentioned above are SDT DRBs. When the UE initiates SDT, it is necessary to restore the UE context, which may specifically include the SDT DRB, and optionally, the non-SDT DRB.

[0097] Please refer to Figure 5 and Figure 6 , Figure 5 is a schematic diagram of the 4-step-SDT process under the control plane provided by an embodiment of the present application, Figure 6 is a schematic diagram of the 4-step-SDT process under the user plane provided by an embodiment of the present application.

[0098] As Figure 5 shown, Figure 5 The SDT shown includes but is not limited to the following steps:

[0099] S101: The UE sends a random access preamble to the base station.

[0100] S102: In response to the random access preamble, the base station sends a random access response (RAR) to the UE.

[0101] S103: Based on the resources scheduled by the RAR, the UE sends an RRC request message carrying uplink small-packet data to the base station.

[0102] S104: The base station sends the uplink small-packet data to the core network.

[0103] S105: The base station sends an RRC response message to the UE.

[0104] Specifically, when the UE has uplink small packet data to send to the base station, the UE can initiate 4-step RA. After the UE sends a random access preamble to the base station, it can monitor the 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 can determine that this RA fails. The RAR is used to schedule uplink resources (uplink grant, UL grant) for the UE, so that the UE can send msg3 (i.e., the above RRC request message) based on the resources scheduled by the RAR, where msg3 carries the uplink small packet data. For example, the msg3 sent by the UE can be an RRC Early Data Request message.

[0105] When the UE is in different RRC states and different service scenarios, the RRC request message can be different. For example, the msg3 sent by a UE in the RRC IDLE state (optionally, at this time, the UE can store UE context such as configuration information for obtaining the key for encrypting uplink small packet data) can be an RRC Connection Request message, an RRC Connection Resume Request message, an RRC Early Data Request message, an RRC Resume Request message, an RRC Setup Request message, or other RRC messages with the same function but not standardized by the 3rd generation partnership project (3GPP). The msg3 sent by a UE in the RRC INACTIVE state can also be an RRC Connection Request message, an RRC Connection Resume Request message, an RRC Early Data Request message, an RRC Resume Request message, an RRC Setup Request message, or other RRC messages with the same function but not standardized by 3GPP.

[0106] Among them, the uplink small packet data can be carried in msg3, borne by the SRB and transmitted on the CCCH. For example, the uplink small packet data can be carried in an IE related to the NAS layer included in the RRC Early Data Request message (such as the dedicatedInfoNAS IE) and transmitted on the CCCH.

[0107] Accordingly, the base station can send uplink small packet data to the core network through msg3 carrying the uplink small packet data. For example, the base station can send uplink small packet data to the core network by forwarding the NAS layer-related IEs included in msg3. The base station can also send a contention resolution message to the UE. The contention resolution message is actually a contention resolution MAC control element (CE), and the contention resolution message is used to indicate that the UE's current random access is successful.

[0108] Finally, the base station can send an RRC response message to the UE. In some embodiments, before S105, if the core network has downlink small packet data to send to the UE, the core network can send the downlink small packet data to the base station. Then, in S105, the base station can send the downlink small packet data to the UE through the RRC response message carrying the downlink small packet data. Among them, the downlink small packet data can be carried in the RRC response message and transmitted on the CCCH. For example, the RRC response message is an RRCEarlyDataComplete message, and the downlink small packet data can be carried in the NAS layer-related IEs included in the RRCEarlyDataComplete message and transmitted on the CCCH.

[0109] If the UE does not receive the RRC response message, it is considered that the uplink small packet data transmission is unsuccessful. If the UE receives the RRC response message sent by the base station, it can obtain whether the uplink small packet data transmission is successful according to the RRC response message. For example, if the RRC response message sent by the base station is an RRCEarlyDataComplete message or an RRCConnectionSetup message, the UE can obtain that the uplink small packet data transmission is successful according to the RRC response message.

[0110] In some embodiments, if the core network has no further need to transmit data, the RRC response message can be used to indicate that the uplink small packet data transmission of the UE is successful and indicate that the UE remains in the current non-connected state. For example, the RRC response message is an RRCEarlyDataComplete message, an RRCConnectionRelease message, an RRCRelease message, or other RRC messages with the same function but not standardized by 3GPP. The UE can obtain that the uplink small packet data transmission is successful according to the RRC response message.

[0111] In some embodiments, if the core network has a further need to transmit data, the core network may trigger an indication process for connection establishment, and the RRC response message may be used to indicate that the UE enters the RRC CONNECTED state. For example, the RRC response message is an RRCConnectionSetup message, an RRCConnectionResume message, an RRCSetup message, an RRCResume message, or other RRC messages with the same function but not standardized by 3GPP. The UE may obtain the success of the above uplink small packet data transmission according to the RRC response message.

[0112] In some embodiments, the RRC response message is used to indicate the failure of the UE's uplink small packet data transmission and indicate that the UE remains in the current non-connected state. For example, the RRC response message is an RRCConnectionReject message, an RRCReject message, or other RRC messages with the same function but not standardized by 3GPP. The UE may obtain the failure of the uplink small packet data transmission according to the RRC response message.

[0113] As Figure 6 shown, Figure 6 The SDT shown includes but is not limited to the following steps:

[0114] S201: The UE sends a random access preamble to the base station.

[0115] S202: In response to the random access preamble, the base station sends an RAR to the UE.

[0116] S203: Based on the resources scheduled by the RAR, the UE sends uplink small packet data and an RRC request message to the base station.

[0117] S204: The base station restores the UE's context and sends the uplink small packet data to the core network.

[0118] S205: The base station sends an RRC response message to the UE.

[0119] Specifically, when the UE has uplink small packet data to send to the base station, the UE may initiate a 4-step RA, and in the third step of the 4-step RA, send msg3 (i.e., the RRC request message) and the uplink small packet data to the base station. For example, the msg3 sent by the UE may be an RRCConnectionResumeRequest message or an RRCResumeRequest message. When the UE is in different RRC states and in different service scenarios, the RRC request message may be different. For details, please refer to Figure 5Examples of RRC request messages are not elaborated here.

[0120] Among them, uplink small packet data can be carried by the DRB and sent on the logical channel DTCH. The RRC request message can be carried by the SRB and sent on the logical channel CCCH, and then the MAC layer multiplexes the two into a MAC protocol data unit (PDU) and sends it to the base station (the process of multiplexing into a MAC PDU can be called packet assembly). That is to say, after the UE receives the RAR, before the UE sends msg3 and uplink small packet data to the base station, packet assembly will also be performed. And the data actually sent by the UE in S203 is the above MAC PDU.

[0121] Correspondingly, the base station can restore the UE context and send the received uplink small packet data to the core network. The base station can also send a contention resolution message (i.e., contention resolution MAC CE) to the UE to indicate that the UE's current random access is successful.

[0122] Finally, the base station can send an RRC response message to the UE. In some embodiments, before S205, if the core network has downlink small packet data to send to the UE, the core network can send the downlink small packet data to the base station. Then, in S205, the base station can send the downlink small packet data together with the RRC response message when sending the RRC response message. Among them, the downlink small packet data can be transmitted on the DTCH and multiplexed with the RRC response message transmitted on the DCCH.

[0123] If the UE does not receive the RRC response message, it is considered that the uplink small packet data transmission is unsuccessful. If the UE receives the RRC response message sent by the base station, the UE can obtain whether the uplink small packet data transmission is successful according to the RRC response message. For example, if the RRC response message sent by the base station is an RRCConnectionRelease message, an RRCConnectionResume message, an RRCConnectionSetup message, an RRCRelease message, an RRCResume message, or an RRCSetup message, then the UE can obtain that the above uplink small packet data transmission is successful according to the RRC response message. For the description of the RRC response message, please refer specifically to Figure 5 the description of the RRC response message in

[0124] Figure 5 and Figure 6Taking the case where the UE executes S101 and / or S201 when there is uplink small packet data to be sent to the base station, that is, the UE actively initiates SDT as an example for illustration. However, in the specific implementation, there is also a case where the UE passively initiates the transmission process of small packet data under the indication of the base station. For example, the mobile terminated (MT) EDT in LTE (abbreviated as MT-EDT). The transmission process of this case is similar to the Figure 5 and Figure 6 shown transmission process, and the differences are specifically described as follows:

[0125] Before S101 or S201, when there is downlink small packet data to be sent from the core network to the UE, the core network can send a paging message to the base station. Optionally, the paging message can carry the data volume information of the downlink small packet data. Correspondingly, the base station can send a paging message to the UE to enable the UE to initiate 4step-RA. For example, the base station can trigger MT-EDT according to the paging message and send a paging message carrying the MT-EDT indication to the UE to enable the UE to trigger the MO-EDT for MT-EDT. Among them, different from the Figure 5 shown process: the RRC request message sent by the UE to the base station in S103 may not carry the uplink small packet data, and optionally, it may also carry the reason information for triggering MT-EDT. Correspondingly, S104 can be changed to the base station receiving the downlink small packet data sent by the core network. The RRC response message sent by the base station to the UE in S105 carries the downlink small packet data. Different from the Figure 6 shown process: in S203, the UE can only send an RRC request message to the base station without sending the uplink small packet data, and optionally, it may also carry the reason information for triggering MT-EDT. Correspondingly, S204 can be changed to the base station receiving the downlink small packet data sent by the core network. S205 can be changed to the base station sending an RRC response message and the downlink small packet data to the UE.

[0126] Please refer to Figure 7 and Figure 8 , Figure 7 which is a schematic flow diagram of 2step-SDT under the control plane provided by an embodiment of the present application, Figure 8 which is a schematic flow diagram of 2step-SDT under the user plane provided by an embodiment of the present application.

[0127] As Figure 7 shown, Figure 7 the SDT shown includes but is not limited to the following steps:

[0128] S301: The UE sends a random access preamble and an RRC request message carrying the uplink small packet data to the base station.

[0129] S302: The base station sends uplink small-packet data to the core network.

[0130] S303: The base station sends an RRC response message to the UE.

[0131] Specifically, when the UE has uplink small-packet data to send to the base station, the UE can initiate 2-step RA, and in the first step of 2-step RA, send a random access preamble and msgA carrying the uplink small-packet data (i.e., the above RRC request message) to the base station. For example, the msgA sent by the UE can be an RRCResumeRequest message. Depending on the different RRC states of the UE and different service scenarios, the RRC request message can be different. For specific examples, refer to Figure 5 the examples of RRC request messages in, which will not be elaborated here.

[0132] Among them, the RRC request message carrying the uplink small-packet data can be carried in the physical uplink share channel (PUSCH) payload and can be transmitted on the CCCH.

[0133] Correspondingly, the base station can send the uplink small-packet data to the core network through msgA. For example, the base station can send the above uplink small-packet data to the core network by forwarding the RRCResumeRequest message carrying the uplink small-packet data. The base station can also send a contention resolution message (i.e., contention resolution MAC CE) to the UE to indicate that the UE's current random access is successful.

[0134] Finally, the base station can send an RRC response message to the UE. In some embodiments, before S303, if the core network has downlink small-packet data to send to the UE, the core network can send the downlink small-packet data to the base station. Then, in S303, the base station can send the downlink small-packet data to the UE through the RRC response message carrying the downlink small-packet data. Among them, the downlink small-packet data can be carried in the RRC response message and transmitted on the CCCH.

[0135] If the UE does not receive the RRC response message, it is considered that the uplink small-packet data transmission is unsuccessful. If the UE receives the RRC response message sent by the base station, the UE can determine whether the uplink small-packet data transmission is successful according to the response message. For example, if the RRC response message sent by the base station is an RRCRelease message, an RRCSetup message, or an RRCResume message, the UE can determine that the above uplink small-packet data transmission is successful according to the RRC response message. For the description of the RRC response message, refer to Figure 5The description of the RRC response message will not be elaborated here.

[0136] As Figure 8 shown, Figure 8 the SDT shown includes but is not limited to the following steps:

[0137] S401: The UE sends a random access preamble, an RRC request message, and uplink small packet data to the base station.

[0138] S402: The base station restores the UE's context and sends the uplink small packet data to the core network.

[0139] S403: The base station sends an RRC response message to the UE.

[0140] Specifically, the process of S401 is similar to Figure 7 S301, the difference being that in S401, the uplink small packet data is not carried in the RRC request message but is sent together with the RRC request message. When the UE is in different RRC states and in different service scenarios, the RRC request message can be different. For details, refer to Figure 5 the example of the RRC request message in

[0141] In S401, the RRC request message and the uplink small packet data can be carried in the PUSCH payload. Moreover, the uplink small packet data can be carried by a DRB and sent on the logical channel DTCH, and the RRC request message can be carried by an SRB and sent on the logical channel CCCH. Then, the MAC layer multiplexes the two into a MAC PDU (i.e., packet assembly). Then, the RRC request message and the uplink small packet data sent by the UE to the base station in S401 are actually the MAC PDU obtained by the above packet assembly.

[0142] Correspondingly, the base station can restore the UE context and send the received uplink small packet data to the core network. The base station can also send a contention resolution message (i.e., contention resolution MAC CE) to the UE to indicate that the UE's current random access is successful.

[0143] Finally, the base station can send an RRC response message to the UE. In some embodiments, before S403, if the core network has downlink small packet data to send to the UE, the core network can send the downlink small packet data to the base station. Then, in S403, the base station can send the downlink small packet data to the UE together when sending the RRC response message. Among them, the downlink small packet data can be transmitted on the DTCH and multiplexed with the RRC response message transmitted on the DCCH.

[0144] If the UE does not receive the RRC response message, it is considered that the uplink small packet data transmission is unsuccessful. If the UE receives the RRC response message sent by the base station, the UE can obtain whether the uplink small packet data is successfully transmitted according to the RRC response message. For example, the RRC response message sent by the base station can be an RRCRelease message, an RRCSetup message or an RRCResume message, then the UE can obtain the successful transmission of the uplink small packet data according to the RRC response message. For the specific description of the RRC response message, please refer to Figure 5 the description of the RRC response message in it, which will not be elaborated here.

[0145] Figure 7 and Figure 8 Taking the case where the UE executes S301 and / or S401 when there is uplink small packet data to be sent to the base station, that is, the UE actively initiates the transmission process of the small packet data as an example for illustration. However, in the specific implementation, there is also a case where the UE is instructed by the base station to passively initiate the transmission process of the small packet data. The transmission process of this case is similar to Figure 7 and Figure 8 the transmission process shown, and the differences are specifically described as follows:

[0146] Before S301 or S401, when there is downlink small packet data sent from the core network to the UE, the core network can send a paging message to the base station. Optionally, this paging message can carry the data volume information of the downlink small packet data. Correspondingly, the base station can send a paging message to the UE to enable the UE to initiate 2step-RA. Among them, different from Figure 7 the process shown: in S301, the RRC request message sent by the UE to the base station may not carry the uplink small packet data. Different from Figure 8 the process shown: in S401, the UE can only send the random access preamble and the RRC request message to the base station without sending the uplink small packet data. Correspondingly, S302 and S402 can be changed to the base station receiving the downlink small packet data sent by the core network. The RRC response message sent by the base station to the UE in S303 carries the downlink small packet data. The base station sends the RRC response message and the downlink small packet data to the UE in S403.

[0147] Not limited to the RA-based SDT listed above, in a specific implementation, SDT can also be implemented based on configured grants. That is, a UE in a non-connected state can also send an RRC request message and uplink packet data to a base station based on pre-configured uplink resources, or send an RRC request message to a base station based on pre-configured uplink resources and receive downlink packet data sent by the base station. Among them, the pre-configured uplink resources are, for example but not limited to, pre-configured uplink resources (preconfigured uplink resource, PUR) or configured grants type 1 (configured grants type 1, CG Type 1).

[0148] It is understandable that the base station may not configure the above pre-configured uplink resources for the UE. At this time, the UE in the non-connected state can only perform RA-based SDT. This application takes the example that the base station does not configure the above pre-configured uplink resources for the UE as an example, so the SDT in the following embodiments is actually RA-based SDT.

[0149] When the UE and the network device perform SDT, the UE may obtain new data packets to be transmitted. Figure 6 After S201 and before S205, the UE obtains a new data packet. Figure 8 After S401 and before S403, the UE obtains a new data packet. At this time, the UE can trigger reporting of a BSR to the network device, but there may be no BSR resources, then the UE can trigger reporting of an SR to the network device. However, the network device usually only allocates SR resources to UEs in the RRC CONNECTED state, so the UE that is performing an SDT can only initiate a new RA or SDT to request scheduling resources from the network device. Exemplarily, when the new data packet is a small packet, the UE can re-initiate a new SDT, and when the new data packet is a large packet, the UE can re-initiate a new RA.

[0150] When the UE initiates a new RA or SDT, it can wait for the current SDT to end before initiating a new RA or SDT, but the transmission delay of the new data packet will be longer. Alternatively, the UE can stop the current SDT and directly initiate a new RA or SDT, but the delay of the currently transmitted small packet data will be longer. Alternatively, the UE can directly initiate a new RA or SDT without stopping the current SDT, but if the new data packet is a small packet data, it will also bring unnecessary signaling overhead and affect the transmission delay of the new data packet. In other words, the transmission delay of the currently transmitted small packet data or the new data packet will be longer.

[0151] The present application provides a data transmission method, which can be applied to the scenario where a UE obtains a new data packet while the UE and the network device are performing SDT. The network device can configure an SR applied to the non-connected state for the UE, abbreviated as inactive SR (inactive SR), which can specifically include a first SR and a second SR. When the UE obtains a new data packet, if the UE does not have a resource for sending a BSR, it can trigger the reporting of the inactive SR, and then the UE can report the inactive SR to the network device so that the network device can obtain the UE's data transmission requirements. Among them, when the new data packet is a small packet of data, the UE can send the first SR to the network device, and the network device can dynamically schedule uplink resources for the UE according to the first SR, and the uplink resources are used for the UE to send the new data packet to the network device. The specific process is as follows Figure 10 , Figure 12 as shown. When the second data packet is a large packet of data, the UE can send the second SR to the network device, and the network device can instruct the UE to enter the RRC CONNECTED state in response to the second SR, and the UE can transmit the new data packet in the RRC CONNECTED state. The specific process is as follows Figure 11 , Figure 13 as shown. Therefore, the UE does not need to initiate a new RA or SDT, saving unnecessary signaling overhead and power consumption, and can reduce the transmission delay of the new data packet while not affecting the delay of the currently transmitted small packet of data, and the user experience is better.

[0152] Among them, the inactive SR can be used for the UE in the non-connected state to request scheduling resources from the network device, and the inactive SR can be a PUCCH resource. The DRBs configured by the network device for the UE can include a DRB for carrying small packet of data, that is, the SDT DRB, and a DRB for carrying large packet of data, that is, the non-SDT DRB. When the UE initiates SDT, it can resume the SDT DRB, and optionally, it can also resume the non-SDT DRB.

[0153] The network device can configure the inactive SR for the UE in one of the following ways, but not limited to any of them:

[0154] Method 1: When the UE is in the RRC CONNECTED state, the network device configures available inactive SRs for the logical channels included in the DRB of the UE. The available inactive SRs can be identified by inactive SR IDs. For example, the network device configures an available inactive SR for logical channel 1 of the UE, and the inactive SR ID of this available inactive SR is 1. Moreover, when the UE is in the RRC CONNECTED state, the network device can also configure multiple sets of inactive SRs for the UE. Each set of inactive SRs can include an inactive SR ID. Each set of inactive SRs can also include SchedulingRequestConfig information and SchedulingRequestResourceConfig information. For specific details, please refer to the description above. Figure 4 description.

[0155] Method 2: When the UE is in the RRC CONNECTED state, the network device configures available inactive SRs for the logical channels included in the DRB of the UE. The available inactive SRs can be identified by inactive SR IDs. For example, the network device configures an available inactive SR for logical channel 1 of the UE, and the inactive SR ID of this available inactive SR is 1. When the UE transitions from the RRC CONNECTED state to the non-connected state or when the UE ends the currently ongoing SDT process, the network device can also configure multiple sets of inactive SRs for the UE through an RRC response message (such as an RRCRelease message). Each set of inactive SRs can include an inactive SR ID. Each set of inactive SRs can also include SchedulingRequestConfig information and SchedulingRequestResourceConfig information. For specific details, please refer to the description above. Figure 4 description.

[0156] Method 3: When the UE transitions from the RRC CONNECTED state to the non-connected state or when the UE ends the currently ongoing SDT process, the network device can also configure multiple sets of inactive SRs for the UE through an RRC response message (such as an RRCRelease message). Each set of inactive SRs can include the ID of the logical channel that can use this inactive SR. Each set of inactive SRs can also include the above Figure 4SchedulingRequestConfig information and SchedulingRequestResourceConfig information.

[0157] In Method 1 and Method 2, the available inactive SRs included in the logical channel configurations of the SDT DRB can be the first SR, and the available inactive SRs included in the logical channel configurations of the non-SDT DRB can be the second SR. Therefore, after receiving the first SR, the network device can determine that the corresponding logical channel is the logical channel included in the SDT DRB, and thus determine that the data to be transmitted by the UE is small-packet data.

[0158] In Method 3, the first SR configured by the network device for the UE includes the logical channel ID that can use the first SR, and the ID of the logical channel that can use the first SR can be the ID of the logical channel included in the SDT DRB. The second SR configured by the network device for the UE includes the logical channel ID that can use the second SR, and the ID of the logical channel that can use the second SR can be the ID of the logical channel included in the non-SDT DRB.

[0159] In this application, the logical channel included in the DRB of the above UE and the available inactive SR configured for this logical channel can be referred to as having a binding relationship. It can also be said that the inactive SR configured by the above network device for the UE and the logical channel that can use this inactive SR have a binding relationship.

[0160] After receiving the first SR, the network device can determine that the logical channel having a binding relationship with the first SR is the logical channel included in the SDT DRB, and thus determine that the data to be transmitted by the UE is small-packet data. After receiving the second SR, the network device can determine that the corresponding logical channel is the logical channel included in the non-SDT DRB, and thus determine that the data to be transmitted by the UE is large-packet data. Examples of the configured first SR and second SR can be seen below Figure 9 .

[0161] Please refer to Figure 9 , Figure 9 An exemplary schematic diagram showing the DRBs recovered by the UE when the UE initiates SDT. Figure 9 Taking the example where the UE recovers the SDT DRB and non-SDT DRB when the UE initiates SDT, and the inactive SRs configured by the network device for the UE include the first SR and the second SR for illustration.

[0162] As Figure 9As shown, the DRBs recovered by the UE when the UE initiates SDT may include DRB1, DRB2, DRB3, and DRB4. Among them, DRB1 and DRB2 are DRBs for transmitting small-packet data, that is, SDT DRBs, and DRB3 and DRB4 are DRBs for transmitting large-packet data, that is, non-SDT DRBs. DRB1 may include logical channel 1, DRB2 may include logical channel 2, and the logical channels having a binding relationship with the first SR may be logical channel 1 and logical channel 2. Therefore, when the new data packet obtained by the UE is small-packet data, that is, the new data packet can be carried by DRB1 and DRB2, the UE can send the first SR to the network device. After receiving the first SR, the network device can determine that there is small-packet data to be transmitted by the UE.

[0163] Similarly, DRB3 may include logical channel 3, DRB3 may include logical channel 4, and the logical channels having a binding relationship with the second SR may be logical channel 3 and logical channel 4. Therefore, when the new data packet obtained by the UE is large-packet data, that is, the new data packet is carried by DRB3 and DRB4, the UE can send the second SR to the network device. After receiving the second SR, the network device can determine that there is large-packet data to be transmitted by the UE.

[0164] In some embodiments, the UE can send an inactive SR to the network device only after determining that the configuration of the inactive SR takes effect. Optionally, the UE can determine that the inactive SR takes effect when receiving the configuration message based on the inactive SR sent by the network device. Optionally, the UE can also determine that the inactive SR takes effect when receiving the first activation message sent by the network device for indicating the activation of the inactive SR after receiving the configuration message based on the inactive SR sent by the network device. Among them, the first activation message may be downlink control information (DCI), for example, the DCI corresponding to the RAR sent by the network device, or the DCI corresponding to the contention resolution MAC CE sent by the network device. The above configuration message based on the inactive SR may be the RRC response message sent by the network device before the UE performs the SDT process. For the description of the RRC response message, refer to the Figure 5 description of the RRC response message above. For example, this configuration message is the RRC Release message sent during the SDT process before the UE performs the SDT process, or this configuration message is the RRC Resume message sent during the RA process before the UE performs the RA.

[0165] In some embodiments, the UE also needs to meet the conditions for reporting an inactive SR before it can send an inactive SR to the network device. The conditions for the UE to report an inactive SR include that the UE is in the SDT process and the UE maintains uplink synchronization. When the UE obtains a second data packet during the SDT process and the UE has no resources to send a BSR, the reporting of the inactive SR can be triggered at this time. When the UE maintains uplink synchronization, the UE can send an inactive SR. For example, the UE is in the SDT process, but at this time the UE has no TA, then after the UE completes contention resolution and when the TAT is running, it reports an inactive SR to the network device. Or, the UE is in the SDT process, and the UE's current TA is valid, that is, the TAT is running, and this TA can be obtained by the UE during the RA process or the SDT process before the above SDT process, then the UE can directly report an inactive SR to the network device.

[0166] It should be noted that the SDT process performed by the above UE may include the start and the end of the SDT process. It can be that the UE sends a random access preamble to the network device to indicate the start of the SDT process, or it can be that the UE sends msg3 or msgA to the network device to indicate the start of the SDT process. For example, the UE executes the above Figure 6 S201 or S203 to indicate the start of the SDT process, or the UE executes the above Figure 8 S401 which indicates the start of the SDT process. It can be that the UE receives an RRC response message sent by the network device to indicate the end of the SDT process. For example, the UE executes the above Figure 6 S205 to indicate the end of the SDT process, or the UE executes the above Figure 8 S403 to indicate the end of the SDT process.

[0167] This application takes the example where when the UE sends an inactive SR to the network device, the configuration of the inactive SR has taken effect and the conditions for reporting the inactive SR are met.

[0168] Next, based on some of the above Figures 1 - 8 shown embodiments, the data transmission method in this application is described. The following embodiments are described by taking the transmission process of uplink small packet data under the user plane protocol stack as an example.

[0169] First, the data transmission method when the SDT being performed by the UE is 4-step SDT is introduced.

[0170] Please refer to Figure 10 , Figure 10It is a schematic flowchart of a data transmission method provided by an embodiment of this application. This method can be applied to Figure 1 the communication system shown in Figure 1 where the network device and the UE in this method can be Figure 10 the network device 120 and the UE 130 shown in

[0171] S501: The UE obtains the first data packet.

[0172] Specifically, when the first data packet obtained by the UE is a small packet of data, the UE initiates 4step-SDT, that is, executes S502.

[0173] S502: The UE sends a random access preamble to the network device.

[0174] S503: In response to the random access preamble, the network device sends an RAR to the UE.

[0175] S504: Based on the resources scheduled by the RAR, the UE sends the first data packet and an RRC request message to the network device.

[0176] S505: The network device restores the UE context and sends the first data packet to the core network.

[0177] Specifically, S502 - S505 is the same as Figure 6 the above S201 - S204 and will not be elaborated here.

[0178] S506: The network device sends a contention resolution message to the UE.

[0179] Specifically, the network device sends a contention resolution message (i.e., contention resolution MAC CE) to the UE to indicate that the current SDT is successful.

[0180] Among them, the order of S505 and S506 is not limited.

[0181] S507: The UE obtains the second data packet.

[0182] S508: When the second data packet is a small packet of data, the UE sends the first SR to the network device.

[0183] Specifically, the network device may configure a first SR for the UE before S501, that is, configure the binding relationship between the first SR and the logical channels included in the SDT DRB. Therefore, after receiving the first SR, the network device can determine that there is small packet data to be transmitted by the UE. Specifically, during the 4-step SDT process, if the newly obtained second data packet of the UE is small packet data carried by the recovered SDT DRB, the UE may trigger the reporting of a BSR for indicating the small packet data carried by the SDT DRB. When the UE does not have a BSR resource for reporting this BSR, the UE may trigger the reporting of the first SR, and then the UE may send the first SR to the network device.

[0184] In some embodiments, the UE may obtain the second data packet before packing the first data packet and the RRC request message (i.e., multiplexing the first data packet and the RRC request message into a MAC PDU at the MAC layer). That is, S507 is after S501 and before S504, and the order of S507 and S502, S503 is not limited. For example, if the current SDT is the SDT shown above, the UE may obtain a new second data packet after S201 and before S203 shown above. Figure 6 the Figure 6 above

[0185] Exemplarily, the situation where the UE does not have a BSR resource may be: the resources scheduled by the RAR are greater than or equal to the sum of the resources for transmitting the third data packet and the RRC request message, but less than the sum of the resources for transmitting the third data packet, the RRC request message, and the first BSR. That is, the UE does not have a resource for transmitting the first BSR. Among them, the third data packet may be the data packet with a higher priority among the first data packet and the second data packet, the first BSR may indicate the data volume of the fourth data packet, and the fourth data packet may be the data packet with a lower priority among the first data packet and the second data packet. It should be noted that in this case, what is actually sent in S504 is the third data packet. When the priority of the first data packet is higher than or equal to the priority of the second data packet, the first data packet is sent in S504. When the priority of the first data packet is lower than the priority of the second data packet, the second data packet is sent in S504. At this time, due to the limited uplink resources scheduled by the RAR, the UE may preferentially send small packet data with a higher priority instead of sending a BSR. It can be understood that when the uplink resources scheduled by the network device are limited, the priority of the UE sending a data packet with a higher priority is higher than the priority of the UE sending a BSR MAC CE.

[0186] In some embodiments, the UE may obtain the second data packet after packing the first data packet and the RRC request message, that is, S507 is after S504, and the order of S507 and S505, S506 is not limited. For example, if the current SDT is the SDT shown above, Figure 6For the SDT shown, the UE can obtain a new second data packet after S203 and before S205 as shown in Figure 6 . Figure 6 After S203 and before S205 as shown in and

[0187] , the UE can obtain a new second data packet.

[0187] Exemplarily, the situation where the UE has no BSR resource can be as follows: there is no subsequent transmission for the currently ongoing SDT. For example, when the UE initiates the current SDT process, the resources scheduled by the RAR are greater than or equal to the sum of the resources for transmitting the first data packet and the RRC request message. That is, the UE can complete the transmission of the current first data packet only through one transmission of msg3. Therefore, in S504, the UE only needs to send the first data packet and the RRC request message without carrying the second BSR for indicating subsequent transmission. Since the network device does not receive the second BSR sent by the UE in S504, it can be considered that after the UE completes the transmission of the first data packet, the UE has no subsequent data transmission requirement. Therefore, the network device will end the SDT process (such as sending an RRC response message to the UE) after completing the transmission of the first data packet, resulting in the UE having no resource to send the third BSR, and the third BSR can indicate the data volume of the second data packet.

[0188] S509: In response to the first SR, the network device allocates the first transmission resource for the UE.

[0189] Specifically, the network device can determine that the second data packet to be transmitted by the UE is small packet data according to the first SR, and thus can dynamically schedule the first transmission resource for the UE. The first transmission resource is used for the UE to send the second data packet to the network device, that is, for the UE to execute S510.

[0190] Among them, the size of the first transmission resource dynamically scheduled by the above network device for the UE can depend on the network device. For example, the network device determines the size of the first transmission resource based on the current load status. Or, the size of the resource dynamically scheduled by the network device for the UE meets the size of the resource for scheduling small packet data specified in the SDT process. Optionally, the first transmission resource can also be greater than the size of the resource for scheduling small packet data specified in the currently ongoing SDT process.

[0191] S510: The UE uses the first transmission resource to send the second data packet to the network device.

[0192] S511: The network device sends the first response message to the UE.

[0193] Specifically, S511 is the same as S205 above. The first response message is the RRC response message above, such as the RRCRelease message. For specific details, please refer to the description in Figure 5 and will not be elaborated here. Figure 6 The first response message is the RRC response message above, such as the RRCRelease message. For specific details, please refer to the description in Figure 5 and will not be elaborated here. Figure 5 The first response message is the RRC response message above, such as the RRCRelease message. For specific details, please refer to the description in Figure 5 and will not be elaborated here. Figure 5 For specific details, please refer to the description in Figure 5 and will not be elaborated here.

[0194] InFigure 10 In the method shown, during the SDT process between the UE and the network device, the UE obtains a second data packet. The UE can promptly notify the network device of the arrival of new small packet data through the first SR. In response to the first SR, the network device can dynamically schedule the first transmission resource for the UE, enabling the UE to use the first transmission resource to send the second data packet. Therefore, the UE can continue to transmit new small packet data in the non-connected state without initiating a new RA or SDT, avoiding unnecessary signaling overhead and the situation of the UE entering the RRC CONNECTED state and increasing power consumption. At the same time, the transmission delay of the second data packet can be reduced without affecting the transmission delay of the first data packet.

[0195] Please refer to Figure 11 , Figure 11 which is a schematic flowchart of another data transmission method provided by an embodiment of this application. This method can be applied to Figure 1 the communication system shown, and the network device and the UE in this method can be Figure 1 the network device 120 and the UE 130 shown. Figure 11 Taking the second data packet as a large packet data as an example for illustration. This method includes but is not limited to the following steps:

[0196] S601: The UE obtains a first data packet.

[0197] Specifically, when the first data packet obtained by the UE is small packet data, the UE initiates 4step-SDT, that is, executes S602.

[0198] S602: The UE sends a random access preamble to the network device.

[0199] S603: In response to the random access preamble, the network device sends an RAR to the UE.

[0200] S604: Based on the resources scheduled by the RAR, the UE sends the first data packet and an RRC request message to the network device.

[0201] S605: The network device restores the UE context and sends the first data packet to the core network.

[0202] S606: The network device sends a contention resolution message to the UE.

[0203] Specifically, S602 - S606 is the same as Figure 10 the above S502 - S506 and will not be elaborated here. Among them, the order of S605 and S606 is not limited.

[0204] S607: The UE obtains a second data packet.

[0205] S608: When the second data packet is a large packet of data, the UE sends a second SR to the network device.

[0206] Specifically, the network device may configure a second SR for the UE before S601, that is, configure the binding relationship between the second SR and the logical channels included in the non-SDT DRB. Therefore, after receiving the second SR, the network device can determine that there is large packet data to be transmitted. Specifically, during the 4-step SDT process, if the newly obtained second data packet is large packet data and there is no BSR resource for reporting the BSR, the UE can trigger the reporting of the second SR, and then the UE can send the second SR to the network.

[0207] In some embodiments, when the UE initiates Figure 11 the 4-step SDT shown, the SDT DRB and non-SDT DRB can be restored. When the newly obtained second data packet is large packet data carried by the non-SDT DRB, the UE can trigger the reporting of a BSR for indicating the large packet data carried by the non-SDT DRB. When the UE does not have a BSR resource for reporting this BSR, the UE can trigger the reporting of the second SR, and then the UE can send the second SR to the network device.

[0208] In some embodiments, when the UE initiates Figure 11 the 4-step SDT shown, only the SDT DRB can be restored, and the non-SDT DRB is not restored. At this time, the BSR triggered by the UE for reporting can be used not only to indicate the small packet data carried by the restored SDT DRB, but also to indicate the large packet data carried by the non-restored non-SDT DRB. Therefore, when the newly obtained second data packet is large packet data, the UE can trigger the reporting of a BSR for indicating the large packet data carried by the non-SDT DRB. When there is no BSR resource for reporting this BSR, the UE can trigger the reporting of the second SR, and then the UE can send the second SR to the network device.

[0209] In some embodiments, the UE may obtain the second data packet before packing the first data packet and the RRC request message, that is, S607 is after S601 and before S604, and the order of S607 and S602, S603 is not limited. Exemplarily, the situation where the UE has no BSR resource may be that the resource scheduled by the RAR is greater than or equal to the sum of the resources for transmitting the first data packet and the RRC request message, but less than the sum of the resources for transmitting the first data packet, the RRC request message, and the third BSR, that is, the UE has no resource for transmitting the third BSR. Among them, the third BSR may indicate the data volume of the second data packet. At this time, due to the limited uplink resources scheduled by the RAR, the UE may preferentially send the small packet data currently being transmitted instead of sending the BSR.

[0210] In some embodiments, the UE may obtain the second data packet after packing the first data packet and the RRC request message, that is, S607 is after S604, and the order of S607 and S605, S606 is not limited. For an example of the situation where the UE has no BSR resource, refer to the example in Figure 10 S508 above where the UE obtains the second data packet after packing the first data packet and the RRC request message.

[0211] S609: In response to the second SR, the network device sends a second response message to the UE.

[0212] Specifically, the network device may determine, based on the second SR, that the second data packet to be transmitted by the UE is large packet data, and thus may send a second response message to the UE. The second response message may be an RRC response message for instructing the UE to enter the RRC CONNECTED state. For example, the second response message is an RRCConnectionResume message, an RRCResume message, or other RRC messages with the same function but not standardized by 3GPP. The UE may enter the RRC CONNECTED state and then transmit the second data packet.

[0213] In Figure 11 the method shown, during the SDT process between the UE and the network device, when the UE obtains the second data packet, the UE may timely notify the network device of the arrival of new large packet data through the second SR. In response to the second SR, the network device may instruct the UE to enter the RRC CONNECTED state so that the UE transmits the second data packet in the RRC CONNECTED state. The UE does not need to initiate a new RA or SDT, saving transmission resources and also avoiding unnecessary signaling overhead and power consumption. At the same time, the transmission delay of the second data packet can be reduced without affecting the transmission delay of the first data packet.

[0214] Next, a data transmission method when the SDT being performed by the UE is 2step - SDT is introduced.

[0215] Please refer to Figure 12 , Figure 12 which is a schematic flowchart of another data transmission method provided by an embodiment of this application. This method can be applied to Figure 1 the communication system shown in Figure 1 , and the network device and UE in this method can be Figure 12 the network device 120 and UE 130 shown in

[0216] S701: The UE obtains a first data packet.

[0217] Specifically, when the first data packet obtained by the UE is a small packet of data, the UE initiates 2step-SDT, that is, S702 is executed.

[0218] S702: The UE sends a random access preamble, an RRC request message, and the first data packet to the network device.

[0219] S703: The network device restores the context of the UE and sends the first data packet to the core network.

[0220] Specifically, S702 - S703 is the same as Figure 8 S401 - S402 above, and will not be elaborated here.

[0221] S704: The network device sends a contention resolution message to the UE.

[0222] Specifically, the network device sends a contention resolution MAC CE to the UE to indicate that the current SDT is successful.

[0223] Among them, the order of S703 and S704 is not limited.

[0224] S705: The UE obtains a second data packet.

[0225] S706: When the second data packet is a small packet of data, the UE sends a first SR to the network device.

[0226] Specifically, during the process of 2step-SDT, if the newly obtained second data packet by the UE is a small packet of data carried by the recovered SDT DRB, the UE can trigger the reporting of a BSR for indicating the small packet of data carried by the SDT DRB. When the UE does not have a BSR resource for reporting this BSR, the UE can trigger the reporting of a first SR, and then the UE can send the first SR to the network device.

[0227] It should be noted that after the UE obtains the second data packet and packets the first data packet and the RRC request message, for example, if the current SDT is the one shown above, the UE can obtain a new second data packet after S401 shown above and before S403. That is to say, the order of S705 and S703, S704 is not limited. Figure 8 As shown in the SDT above, the UE can Figure 8 obtain a new second data packet after S401 shown above and before S403. That is to say, the order of S705 and S703, S704 is not limited.

[0228] Exemplarily, the situation where the UE has no BSR resource can be: there is no subsequent transmission in the current SDT being performed. For example, the resource for transmitting the small packet data of the SDT broadcast or pre-configured by the network device is greater than or equal to the sum of the resources for transmitting the random access preamble, the first data packet, and the RRC request message, that is, the UE can complete the transmission of the current first data packet only through one transmission of msgA. Therefore, in S702, the UE only needs to send the random access preamble, the first data packet, and the RRC request message, without carrying the second BSR. Since the network device does not receive the second BSR sent by the UE in S702, it can be considered that after the UE completes the transmission of the first data packet, the UE has no subsequent data transmission requirement. Therefore, the network device will end the SDT process after completing the transmission of the first data packet (for example, send an RRC response message to the UE), resulting in the UE having no resource to send the third BSR, and the third BSR can indicate the data volume of the second data packet.

[0229] S707: In response to the first SR, the network device allocates the first transmission resource for the UE.

[0230] S708: The UE uses the first transmission resource to send the second data packet to the network device.

[0231] S709: The network device sends the first response message to the UE.

[0232] Specifically, S707 - S709 is the same as S509 - S511 shown above, and will not be elaborated here. Figure 10 and will not be elaborated here.

[0233] Please refer to Figure 13 , Figure 13 which is a schematic flowchart of another data transmission method provided by an embodiment of the present application. This method can be applied to Figure 1 the communication system shown above, and the network device and the UE in this method can be Figure 1 the network device 120 and the UE130 shown above. Figure 13 Taking the second data packet as a large packet data as an example for illustration. This method includes but is not limited to the following steps:

[0234] S801: The UE obtains the first data packet.

[0235] Specifically, when the first data packet obtained by the UE is small packet data, the UE initiates 2step-SDT, that is, executes S802.

[0236] S802: The UE sends a random access preamble, an RRC request message, and the first data packet to the network device.

[0237] S803: The network device restores the UE's context and sends the first data packet to the core network.

[0238] S804: The network device sends a contention resolution message to the UE.

[0239] Specifically, S802 - S804 is the same as Figure 12 the above S702 - S704 and will not be elaborated here. Among them, the order of S803 and S804 is not limited.

[0240] S805: The UE obtains the second data packet.

[0241] S806: When the second data packet is large packet data, the UE sends a second SR to the network device.

[0242] Specifically, during the process of 2step-SDT, if the newly obtained second data packet by the UE is large packet data and there is no BSR resource for reporting the BSR, the UE can trigger the reporting of the second SR, and then the UE can send the second SR to the network. For the description of the UE restoring the DRB, refer to the description of Figure 11 S608 above. It should be noted that the UE obtains the second data packet after packetizing the first data packet and the RRC request message, that is, the order of S805 and S803, S804 is not limited. For an example of the UE having no BSR resource, refer to the description of Figure 12 S706 above.

[0243] S807: In response to the second SR, the network device sends a second response message to the UE.

[0244] Specifically, S807 is the same as Figure 11 the above S609 and will not be elaborated here.

[0245] In a possible implementation, the network device may also configure only the first SR for the UE. If a new second data packet arrives when the UE is performing SDT, the UE may trigger the reporting of a BSR. However, if the UE does not have BSR resources, the UE may trigger the reporting of an inactive SR. When the second data packet is small packet data, the UE may send the first SR to the network device, and the network device may dynamically schedule the first transmission resource for the UE according to the first SR. The first transmission resource is used for the UE to send the second data packet to the network device, and the specific process is as above Figure 10 、 Figure 11 as shown. When the second data packet is large packet data, since the UE is not configured with a second SR, that is, there is no resource for reporting the second SR, the UE may initiate a RA to transmit the second data packet, and the specific process is as follows Figure 14 and Figure 15 as shown

[0246] Among them, Figure 14 taking the SDT being performed by the UE as 4-step SDT as an example for illustration, Figure 15 taking the SDT being performed by the UE as 2-step SDT as an example for illustration

[0247] Please refer to Figure 14 , Figure 14 which is a schematic flow diagram of another data transmission method provided by an embodiment of the present application. This method can be applied to Figure 1 the communication system shown in Figure 1 where the network device and the UE in this method may be Figure 14 the network device 120 and the UE 130 shown in

[0248] S901: The UE obtains a first data packet

[0249] Specifically, when the first data packet obtained by the UE is small packet data, the UE initiates 4-step SDT, that is, executes S902

[0250] S902: The UE sends a random access preamble to the network device

[0251] S903: In response to the random access preamble, the network device sends an RAR to the UE

[0252] S904: Based on the resources scheduled by the RAR, the UE sends the first data packet and an RRC request message to the network device

[0253] S905: The network device restores the UE context and sends the first data packet to the core network

[0254] S906: The network device sends a contention resolution message to the UE.

[0255] Specifically, S902 - S906 is the same as S502 - S506 above and will not be elaborated further. Among them, the order of S905 and S906 is not limited. Figure 10 Specifically, S902 - S906 is the same as S502 - S506 above and will not be elaborated further. Among them, the order of S905 and S906 is not limited.

[0256] S907: The UE obtains the second data packet.

[0257] S908: When the second data packet is a large packet of data, the UE initiates RA.

[0258] Specifically, during the process of 4step - SDT, if the newly obtained second data packet by the UE is a large packet of data, the UE can trigger the reporting of BSR. However, when the UE does not have BSR resources for reporting BSR, the UE can trigger the reporting of inactive SR. However, when the UE does not have resources for reporting SR, the UE can initiate RA to enter the RRC CONNECTED state to transmit the second data packet. Examples where the UE does not have resources for reporting SR include but are not limited to: the network device does not configure SR for the UE, the network device does not configure inactive SR for the UE, the inactive SR configured by the network device for the UE does not take effect, and the UE does not maintain uplink synchronization.

[0259] Among them, RA can be 4step - RA, and the UE can send a random access preamble to the network device and send msg3 based on the RAR sent by the network device. RA can also be 2step - RA, and the UE can send a random access preamble and msgA to the network device. An example of the UE not having BSR resources can be seen in the description of S608 above. Figure 11 The description of S608 above.

[0260] In some embodiments, when the UE initiates Figure 14 the 4step - SDT as shown, the SDT DRB and non - SDT DRB can be restored. When the newly obtained second data packet is a large packet of data carried by the non - SDT DRB, the UE can trigger the reporting of BSR for indicating the large packet of data carried by the non - SDT DRB.

[0261] In some embodiments, when the UE initiates Figure 14When the 4-step SDT shown is performed, only the SDT DRB can be restored, and the non-SDT DRB is not restored. At this time, the BSR triggered and reported by the UE can be used not only to indicate the small packet data carried by the restored SDT DRB, but also to indicate the large packet data carried by the non-restored non-SDT DRB. Therefore, when the newly obtained second data packet is large packet data, the UE can trigger and report a BSR for indicating the large packet data carried by the non-SDT DRB.

[0262] In some embodiments, the UE initiates Figure 14 When the 4-step SDT shown is performed, only the SDT DRB can be restored, and the non-SDT DRB is not restored. The UE initiates Figure 14 When the 4-step SDT shown is performed, if a second data packet is obtained, at this time the NAS layer can instruct the RRC layer to send an RRC request message, and this RRC request message can correspond to the second data packet, that is, the RRC request message is sent when requesting to transmit the second data packet. That is, the UE can trigger and report a BSR for indicating the RRC request message carried by the SRB.

[0263] The above-mentioned RA initiated by the UE can be but is not limited to any one of the following requests:

[0264] Case 1: The UE can wait for the current ongoing SDT to end and then initiate an RA to the network device. That is, when the UE receives the RRC response message sent by the network device, the UE can determine that the current ongoing SDT has ended. For the description of the RRC response message, please refer to Figure 5 the description of the RRC response message in. For example, after S906, if the UE receives the RRCRelease message sent by the network device, the UE can determine that the current ongoing SDT has ended and can directly initiate an RA. This can avoid affecting the transmission delay of the first data packet being currently transmitted.

[0265] Case 2: The UE can end the current ongoing SDT and directly initiate an RA to the network device. For example, the UE no longer listens for the DCI sent by the network device. The DCI is used by the network device to schedule the RAR or RRC response message in response to the random access preamble. Or, the UE is performing a 4-step based RA. After the UE sends the random access preamble to the network device, it no longer sends msg3 and the first data packet to the network device. After ending the current ongoing SDT, the UE can directly initiate an RA to enter the RRC CONNECTED state to transmit the first data packet and the second data packet. This can avoid affecting the transmission delay of the new large packet data (i.e., the second data packet).

[0266] Scenario 3: The UE may not stop the currently ongoing SDT, that is, when the SDT is in progress, initiate an RA to the network device. For example, the UE is performing an SDT based on 4-step RA. After the UE sends msg3 and the first data packet to the network device and before receiving the RRC response message sent by the network device, the UE obtains a new second data packet. At this time, the UE may directly send a random access preamble to the network device, that is, initiate a 4-step RA, or send a random access preamble and msgA to the network device, that is, initiate a 2-step RA. Thus, the transmission delay of the new large packet data (i.e., the second data packet) is avoided from being affected.

[0267] It should be noted that the order of S907 and S902, S903, S904, S905, S906 is not limited, that is, S907 may be after S901 and before S908.

[0268] Please refer to Figure 15 , Figure 15 is a schematic flowchart of another data transmission method provided by an embodiment of the present application. This method can be applied to Figure 1 the communication system shown in Figure 1 where the network device and the UE in this method may be Figure 15 the network device 120 and the UE130 shown in

[0269] S1001: The UE obtains a first data packet.

[0270] Specifically, when the first data packet obtained by the UE is a small packet of data, the UE initiates a 2-step SDT, that is, executes S1002.

[0271] S1002: The UE sends a random access preamble, an RRC request message, and the first data packet to the network device.

[0272] S1003: The network device restores the UE context and sends the first data packet to the core network.

[0273] S1004: The network device sends a contention resolution message to the UE.

[0274] Specifically, S1002 - S1004 is the same as Figure 12 the above S702 - S704 and will not be elaborated here. Among them, the order of S1003 and S1004 is not limited.

[0275] S1005: The UE obtains a second data packet.

[0276] S1006: When the second data packet is a large packet of data, the UE initiates RA.

[0277] Specifically, S1006 is similar to Figure 14 S908 of Figure 14 For the description of S908, at this time, there is no BSR resource example for the UE, which can be seen in the above Figure 12 description of S706.

[0278] It should be noted that the order of S1005, S1002, S1003, and S1004 is not limited, that is, S1005 can be after S1001 and before S1006.

[0279] Not limited to the above-listed situations. In a specific implementation, if the UE and the network device obtain a new second data packet during SDT and there is no resource to transmit the second data packet, the UE can also directly trigger the reporting of inactive SR, such as the first SR and the second SR. When the conditions for reporting inactive SR are met, the UE can send inactive SR to the network device. For the conditions for reporting the above inactive SR, refer to the description of the above inactive SR and the above Figures 10 - 13 description of the UE sending the first SR or the second SR to the network device.

[0280] In a possible implementation, when the UE and the network device perform 4-step SDT, the UE obtains a new small packet of data (i.e., the second data packet) before packing the first data packet and the RRC request message. The UE can carry the first indication information when sending msg3 to request scheduling resources from the network device. In some embodiments, when the UE obtains the second data packet, the UE can first trigger the reporting of BSR. If there is no resource to transmit the BSR, the UE can carry the first indication information when sending msg3. For the description of the UE having no BSR resource, refer to the Figure 10 description of S508 of Figure 12 the description of the UE having no BSR resource in S706 of Figure 16 as shown below.

[0281] Among them, the first indication information may indicate that the UE has data to be transmitted. Optionally, the first indication information may indicate that the UE has small packet data to be transmitted. During the SDT process, the msg3 sent by the UE is actually the MAC PDU obtained by the MAC layer. A MAC PDU may include multiple MAC sub-PDUs (subPDUs). Each MAC subPDU may correspond to a MAC sub-header (subheader), and the content included in each MAC subPDU may be represented by the corresponding MAC subheader. For example, each MAC subheader may correspond to a MAC SDU (Service Data Unit) or a MAC CE. The network device may obtain the content and the indicated function included in the MAC subPDU through the MAC subheader in the MAC PDU. The fields included in the MAC subheader may include: logical channel identity (LCID), reserved bit (R), and fields L and F for indicating the length of the MAC SDU or MAC CE, etc. The first indication information may be represented by the MAC subheader in the MAC PDU, and specific examples are as follows:

[0282] Example 1: The first indication information may be represented by the MAC subheader corresponding to the MAC SDU indicating the RRC request message.

[0283] Optionally, the first indication information may be represented by the LCID included in the above MAC subheader, and the value of this LCID is a new value. The RRC request message is transmitted on the CCCH, that is, the LCID included in the MAC subheader corresponding to the RRC request message is the LCID of the CCCH. For example, the value of the LCID included in this MAC subheader is usually 0, and 0 is the LCID of the logical channel CCCH. If the value of the LCID is 0, the network device may default that the UE has no data to be transmitted. If the value of the LCID is not 0, for example, 35, the network device may determine that the UE has data to be transmitted.

[0284] Optionally, the first indication information may be represented by the reserved bit in the above MAC subheader. For example, when the reserved bit is 0, the network device may determine that the UE has no data to be transmitted, and when the reserved bit is 1, the network device may determine that the UE has data to be transmitted.

[0285] Example 2: The first indication information may be represented by the MAC subheader of the MAC SDU indicating the logical channel corresponding to the DRB.

[0286] Optionally, the first indication information may be indicated by the LCID included in the foregoing MAC subheader, and the value of the LCID is a new value. For example, the value of the LCID included in the foregoing MAC subheader is usually from 1 to 32, and the value of the LCID is a positive integer. If the value of the LCID is any one of the values from 1 to 32, the network device may default that the UE has no data to be transmitted. If the value of the LCID is not any one of the values from 1 to 32, for example, 38, the network device may determine that the UE has data to be transmitted.

[0287] Optionally, the first indication information may be indicated by the reserved bits in the foregoing MAC subheader. For example, when the reserved bit is 0, the network device may determine that the UE has no data to be transmitted, and when the reserved bit is 1, the network device may determine that the UE has data to be transmitted.

[0288] Without being limited to the above example, in a specific implementation, the first indication information may also be indicated by the MAC subheader of the MAC SDU of the logical channel corresponding to other DRBs, and the present application does not limit the specific indication of the first indication information.

[0289] Please refer to Figure 16 , Figure 16 which is a schematic flowchart of another data transmission method provided by an embodiment of the present application. This method may be applied to Figure 1 the communication system shown in Figure 1 where the network device and the UE in this method may be Figure 16 the network device 120 and the UE 130 shown in

[0290] S1101: The UE obtains a first data packet.

[0291] Specifically, when the first data packet obtained by the UE is a small packet of data, the UE initiates 4step-SDT, that is, S1102 is executed.

[0292] S1102: The UE sends a random access preamble to the network device.

[0293] S1103: In response to the random access preamble, the network device sends an RAR to the UE.

[0294] Specifically, S1102 - S1103 is the same as Figure 6 S201 - S202 above and will not be described in detail.

[0295] S1104: The UE obtains a second data packet.

[0296] S1105: Based on the resources scheduled by the RAR, the UE sends a third data packet, an RRC request message, and first indication information to the network device.

[0297] Specifically, the UE can packetize the third data packet and the RRC request message to obtain a MAC PDU. The third data packet can be the data packet with a higher priority among the first data packet and the second data packet. Before packetization, the UE obtains new small packet data (i.e., the second data packet). The UE can determine the content included in the MAC PDU according to the resources scheduled by the RAR.

[0298] If the resources scheduled by the RAR are greater than the sum of the resources for transmitting the third data packet and the RRC request message, but less than the sum of the resources for transmitting the third data packet, the RRC request message, and the first BSR. Among them, the first BSR can indicate the data volume of a fourth data packet, and the fourth data packet can be the data packet with a lower priority among the first data packet and the second data packet. At this time, the UE can determine that the MAC PDU to be sent includes the third data packet and does not include the first BSR, thereby avoiding the low-priority fourth data packet from affecting the transmission of the high-priority third data packet. In the above case, if the UE does not have resources to transmit the first BSR, the UE can carry the first indication information in the MAC PDU during packetization to notify the network device that a new data packet has arrived. The first indication information can be used for the UE to request scheduling resources from the network device.

[0299] Exemplarily, the third data packet is the first data packet, and the fourth data packet is the second data packet. In S1105, the UE will send the higher-priority first data packet instead of the BSR for indicating the data volume of the second data packet, thereby avoiding the low-priority newly obtained data packet from affecting the transmission of the high-priority data packet in the current SDT.

[0300] S1106: The network device sends a contention resolution message to the UE to indicate that the current SDT is successful.

[0301] S1107: In response to the first indication information, the network device allocates second transmission resources for the UE.

[0302] Specifically, the network device can determine that there is small packet data to be transmitted by the UE according to the first indication information in the MAC PDU and dynamically schedule second transmission resources for the UE. The second transmission resources are used for the UE to send the fourth data packet to the network device, that is, for the UE to execute S1108.

[0303] Among them, the size of the second transmission resource dynamically scheduled by the above network device for the UE can depend on the network device. For example, the network device can determine the size of the second transmission resource based on the current load status. Alternatively, the size of the resource dynamically scheduled by the network device for the UE can meet the resource size for scheduling small packet data specified in the SDT process. Optionally, the second transmission resource is greater than the resource for scheduling small packet data specified in the current SDT process.

[0304] S1108: The UE uses the second transmission resource to send the fourth data packet to the network device.

[0305] S1109: The network device sends a first response message to the UE.

[0306] Specifically, S1109 is the same as Figure 6 the above S205, and the first response message is the Figure 5 RRC response message above, such as the RRCRelease message. For specific details, please refer to Figure 5 the description above and will not be elaborated here.

[0307] In some embodiments, when the UE and the network device perform 4-step SDT, if a new second data packet is obtained and the second data packet is small packet data, the UE can trigger the reporting of the BSR. If the second data packet is obtained by the UE before packing the first data packet and the RRC request message, and the UE does not have the resource to report the BSR, the UE can execute the Figure 16 process shown. If the second data packet is obtained by the UE after packing the first data packet and the RRC request message, and the UE does not have the resource to report the BSR, the UE can execute the Figure 10 process shown.

[0308] Not limited to the above-listed situations, in specific implementations, when the UE obtains small packet data, the UE can initiate 4-step SDT or 2-step SDT. Moreover, the UE can send the Figure 16 first indication information described above when sending msg3 or msgA, so that there is a resource to report the BSR or transmit new data when new data arrives later, rather than re-initiating RA or SDT, avoiding unnecessary signaling overhead and power consumption, and reducing data transmission delay.

[0309] In Figure 16In the method shown, if the UE obtains new small packet data during the SDT process, the UE can trigger the reporting of a BSR. If there is no resource for reporting the BSR, the UE can send a third data packet with a higher priority during the current SDT process, and timely notify the network device of the arrival of new small packet data through the first indication information carried in msg3. This not only avoids the low-priority data packets from affecting the transmission of high-priority data packets, but also reduces the transmission delay of the low-priority data packets. Moreover, the UE can continue to transmit low-priority small packet data in the non-connected state without initiating a new RA or SDT, avoiding unnecessary signaling overhead and power consumption.

[0310] Not limited to the above-listed situations, in a specific implementation, if the second data packet newly obtained by the UE and the network device during SDT is a large packet of data, the UE can also timely notify the network device of the arrival of new data packets through the first indication information carried in msg3 to request scheduling resources from the network device. Optionally, when the UE obtains the second data packet, the UE can first trigger the reporting of a BSR. If there is no resource for transmitting the BSR, the UE can carry the first indication information when sending msg3. For the description of the UE having no BSR resource, reference can be made to the description of the UE having no BSR resource in S608 Figure 11 of Figure 12 S706 of this application. This application does not make any limitations in this regard.

[0311] Not limited to the above-listed situations, in a specific implementation, the resources scheduled by the RAR can also be greater than the sum of the resources for transmitting the first data packet, the second data packet, and the RRC request message. Then, the UE can send the first data packet, the second data packet, and the RRC request message to the network device based on the resources scheduled by the RAR.

[0312] Alternatively, the resources scheduled by the RAR can also be greater than the sum of the resources for transmitting the third data packet, the RRC request message, and the first BSR. That is, the UE has BSR resources for reporting the first BSR. Therefore, the UE can send the third data packet, the RRC request message, and the first BSR to the network device based on the resources scheduled by the RAR. The first BSR can indicate the data volume of the fourth data packet. The network device can comprehensively schedule resources according to the first BSR. For example, the network device can dynamically schedule second transmission resources for the UE so that the UE can send the fourth data packet to the network device based on the second transmission resources.

[0313] In a possible implementation manner, when the UE and the network device obtain new data packets during SDT, the UE can trigger the reporting of a BSR. If the UE has resources for reporting the BSR, the UE can send a BSR to the network device. The network device determines whether the data to be transmitted by the UE is large packet data or small packet data according to the reported BSR, which is convenient for the network device to comprehensively schedule resources for the UE. The process example is as follows Figure 17 and Figure 18 shown.Figure 17 and Figure 18 Taking the 4-step SDT that the UE is performing as an example for illustration.

[0314] Among them, the BSR sent by the UE is actually the BSR MAC CE obtained by the MAC layer. The BSR MAC CE can be a short BSR MAC CE (short BSR MAC CE), or a short truncated BSR MAC CE (short truncated BSR MAC CE), and the fields included can be seen in Table 1 below; it can also be a long BSR MAC CE (long BSR MAC CE), or a long truncated BSR MAC CE (long truncated BSR MAC CE), and the fields included can be seen in Table 2 below.

[0315] Table 1 Fields included in short BSR MAC CE or short truncated BSR MAC CE

[0316] LCG ID buffer size

[0317] Among them, the field LCG ID can include the identifier of the LCG reported by the UE, that is, the identifier of the LCG with data to be transmitted. The length of the field LCG ID is 3 bits. The field buffer size is used to indicate the amount of data to be transmitted in the LCG reported by the UE.

[0318] Table 2 Fields included in long BSR MAC CE or long truncated BSR MAC CE

[0319]

[0320] Among them, the field LCGi is used to indicate whether there is data to be transmitted in logical channel group i. The positive integer i can identify a logical channel group, and the value range of i is greater than or equal to 0 and less than or equal to 7. When the value of the field LCGi is the first value, it means that there is data to be transmitted in logical channel group i, and when the value is the second value, it indicates that there is no data to be transmitted in logical channel i. For example, LCG1 is used to indicate whether there is data to be transmitted in logical channel group 1. When the field LCGi is 1, it means that there is data to be transmitted in logical channel group i, and it also means that this BSR includes the amount of data to be transmitted in logical channel group i. When the field LCGi is 0, it means that there is no data to be transmitted in logical channel group i.

[0321] The field buffer size j is used to indicate the amount of data to be transmitted in the j-th LCG with data to be transmitted. For example, assume j = 3, LCG0, LCG1, and LCG3 are all 1, and LCG2, LCG4, LCG5, LCG6, and LCG7 are all 0. Therefore, buffer size1 is used to indicate the amount of data to be transmitted in logical channel group 0, buffer size2 is used to indicate the amount of data to be transmitted in logical channel group 1, and buffer size3 is used to indicate the amount of data to be transmitted in logical channel group 3.

[0322] From the above description, it can be seen that the UE reports the BSR MAC CE in the form of LCGs, that is, the BSR MAC CE is used to indicate the amount of data to be transmitted in at least one LCG, which can be simply referred to as the BSR MAC CE indicating at least one LCG. The network device can obtain the amount of data to be transmitted in the above at least one LCG through the BSR MAC CE, but cannot obtain the amount of data to be transmitted in each logical channel included in each LCG.

[0323] In this application, when the network device configures logical channels for the UE, it can put the logical channels included in the SDT DRB and the logical channels included in the non-SDT DRB into different LCGs. That is to say, it can configure the LCG of the logical channels included in at least one SDT DRB as the first LCG, and configure the LCG of the logical channels included in at least one non-SDT DRB as the second LCG. At this time, it can be said that the first LCG is the LCG corresponding to the SDT DRB, and the second LCG is the LCG corresponding to the non-SDT DRB. It can be understood that the logical channels in the first LCG are used to transmit small-packet data, and the logical channels in the second LCG are used to transmit large-packet data. The first LCG and the second LCG are respectively at least one LCG.

[0324] Exemplarily, the network device can configure the first LCG and the second LCG for the UE through an RRC response message (such as an RRCRelease message). Or the network device can configure the first LCG and the second LCG for the UE when the UE is in the RRC CONNECTED state.

[0325] After receiving the BSR MAC CE sent by the UE, the network device can determine the LCG, the first LCG or the second LCG, indicated therein, that is, determine that the data to be transmitted in the LCG indicated therein is small-packet data or large-packet data. When the LCG indicated by the BSR MAC CE is the first LCG, the network device can determine that the data to be transmitted by the UE is small-packet data. When the LCG indicated by the BSR MAC CE is the second LCG, the network device can determine that the data to be transmitted by the UE is large-packet data.

[0326] Exemplarily, the above Figure 9 In this case, DRB1 and DRB2 are SDT DRBs for transmitting small packet data, and DRB3 and DRB4 are non-SDT DRBs for transmitting large packet data. The logical channel 1 included in DRB1 and the logical channel 2 included in DRB2 may both belong to the first LCG. Assume that the first LCG is logical channel group 2. The logical channel 3 included in DRB3 and the logical channel 4 included in DRB3 may both belong to the second LCG. Assume that the second LCG is logical channel group 3. If the BSR MAC CE sent by the UE indicates logical channel group 2 and does not indicate logical channel group 3. For example, the BSR MAC CE is a short BSR MAC CE, and the LCG ID of this BSR MAC CE includes the identifier of logical channel group 2. Or, the BSR MAC CE is a long BSR MAC CE, the LCG2 of this BSR MAC CE is 1, and the LCG3 is 0. Then, the network device may determine that there is small packet data to be transmitted in logical channel group 2 and the amount of data to be transmitted in logical channel group 2 according to the BSR MAC CE sent by the UE.

[0327] Please refer to Figure 17 , Figure 17 which is a schematic flowchart of another data transmission method provided by an embodiment of this application. This method may be applied to Figure 1 the communication system shown in Figure 1 The network device and the UE in this method may be

[0328] S1201: The UE obtains a first data packet.

[0329] Specifically, when the first data packet obtained by the UE is small packet data, the UE initiates 4step-SDT, that is, executes S1202.

[0330] S1202: The UE sends a random access preamble to the network device.

[0331] S1203: In response to the random access preamble, the network device sends an RAR to the UE.

[0332] Specifically, S1202-S1203 is the same as Figure 6 S201-S202 above and will not be elaborated.

[0333] S1204: The UE obtains a second data packet.

[0334] S1205: Based on the resources scheduled by the RAR, the UE sends the first data packet, an RRC request message, and a third BSR to the network device.

[0335] Specifically, when the UE obtains the second data packet, it may trigger the reporting of the BSR. For example, the BSR may be triggered by the second data packet, or the BSR may be the BSR that has been triggered during the SDT process initiated by the current UE. When the resources scheduled by the RAR are less than the sum of the resources for transmitting the first data packet, the RRC request message, and the second data packet, but greater than or equal to the sum of the resources for transmitting the first data packet, the RRC request message, and the third BSR, that is, the UE has resources to report the third BSR, the UE may perform S1205. The third BSR may indicate the data volume of the second data packet. If the second data packet is small packet data, the LCG indicated in the third BSR is the first LCG of the corresponding SDT DRB. If the second data packet is large packet data, the LCG indicated in the third BSR is the second LCG of the corresponding non-SDT DRB.

[0336] S1206: The network device sends a contention resolution message to the UE to indicate that the UE's current random access is successful.

[0337] S1207: In response to the third BSR, the network device allocates the first transmission resources for the UE, or sends a second response message to the UE.

[0338] Specifically, if the LCG indicated by the third BSR is the first LCG of the corresponding SDT DRB, the network device may determine that there is small packet data to be transmitted by the UE. The network device may dynamically schedule the first transmission resources for the UE, and the first transmission resources are used for the UE to transmit the second data packet. For details, please refer to the description of S510 - S511 above. Figure 10 If the LCG indicated by the third BSR is the second LCG of the corresponding non-SDT DRB, the network device may determine that there is large packet data to be transmitted by the UE. The network device may send a second response message to the UE to indicate that the UE enters the RRC CONNECTED state. The UE may transmit the second data packet after entering the RRC CONNECTED state.

[0339] It should be noted that the UE may obtain the second data packet before packing the RRC request message and the first data packet, that is, the order of S1204 and S1202, S1203 is not limited.

[0340] Please refer to Figure 18 , Figure 18 which is a schematic flowchart of another data transmission method provided by an embodiment of the present application. This method may be applied to Figure 1 the communication system shown in Figure 1 The network device and the UE in this method may be

[0341] S1301: The UE obtains the first data packet.

[0342] Specifically, when the first data packet obtained by the UE is small packet data, the UE initiates 4step-SDT, that is, S1302 is executed.

[0343] S1302: The UE sends a random access preamble to the network device.

[0344] S1303: In response to the random access preamble, the network device sends an RAR to the UE.

[0345] Specifically, S1302 - S1303 is the same as S201 - S202 above Figure 6 and will not be elaborated further.

[0346] S1304: Based on the resources scheduled by the RAR, the UE sends an RRC request message, the first data packet, and the fourth BSR to the network device.

[0347] Specifically, when the UE initiates Figure 18 the 4step-SDT shown, it can trigger the reporting of the fourth BSR. For example, when the UE obtains the first data packet, the NAS layer instructs the RRC layer to send an RRC request message, and this RRC request message can be applicable to Figure 18 the 4step-SDT shown, that is, corresponding to the first data packet. At this time, the UE can trigger the reporting of the fourth BSR for indicating the RRC request message carried by the SRB.

[0348] Exemplarily, when the resources scheduled by the RAR are less than the sum of the resources for transmitting the first data packet and the RRC request message, the UE cannot complete the transmission of the first data packet through one transmission of msg3. Therefore, the UE can send the first part of the data in the first data packet and the fourth BSR in S1304. The part of the first data packet other than the first part is the second part of the data. The fourth BSR can indicate the data volume of the second part of the data.

[0349] S1305: The network device restores the UE context and sends the first data packet to the core network.

[0350] S1306: The network device sends a contention resolution message to the UE.

[0351] Specifically, S1305 - S1306 is the same as S505 - S506 above Figure 10 and will not be elaborated further. Among them, the order of S1305 and S1306 is not limited.

[0352] S1307: In response to the fourth BSR, the network device allocates third transmission resources for the UE.

[0353] Specifically, the third transmission resources are used for the UE to perform subsequent transmission. For example, the network device dynamically schedules the third transmission resources for the UE so that the UE uses the third transmission resources to transmit the second part of the data in the first data packet.

[0354] S1308: The UE obtains a second data packet.

[0355] S1309: The UE uses the third transmission resources to send a third BSR to the network device.

[0356] Specifically, when the UE obtains the second data packet, the second data packet can trigger the reporting of the third BSR. The network device has dynamically scheduled the third transmission resources for the UE. Since the priority of reporting the BSR is higher than the priority of reporting service data, after the UE obtains the third transmission resources, the UE can use the third transmission resources to preferentially send the third BSR. That is, when the UE has resources to report the third BSR, the UE can use the third transmission resources to send the third BSR to the network device. If the second data packet is small packet data, the LCG indicated in the third BSR is the first LCG of the corresponding SDT DRB. If the second data packet is large packet data, the LCG indicated in the third BSR is the second LCG of the corresponding non-SDT DRB.

[0357] S1310: In response to the third BSR, the network device allocates first transmission resources for the UE, or sends a second response message to the UE.

[0358] Specifically, S1310 is the same as S1207 above and will not be elaborated here. Figure 17 and will not be elaborated here.

[0359] It should be noted that the UE can obtain the second data packet after packetizing the RRC request message and the first data packet, that is, the order of S1308 and S1305, S1306, S1307 is not limited.

[0360] It can be understood that the process of 2step-SDT is similar to the above Figure 18 process, except that in 2step-SDT, the fourth BSR is sent together with msgA and will not be elaborated here.

[0361] In some embodiments, in the case of obtaining a new second data packet during SDT between the UE and the network device, if the UE does not have BSR resources, the UE can execute the above Figures 10 - 16 shown process. If the UE has BSR resources, the UE can execute the above Figures 17 - 18 shown process.

[0362] Not limited to this, in a specific implementation, when a UE in the RRC CONNECTED state obtains a data packet, it can also trigger the reporting of a BSR. When the UE has resources to report a BSR, the UE can send a BSR to the network device indicating the LCG with large data packets to be transmitted or small data packets to be transmitted. For specific details, refer to the description of the BSR above. The network device can comprehensively schedule transmission resources based on the reported BSR. For specific details, refer to the description of S1207 above. Figure 17 description of S1207.

[0363] In Figure 17 and Figure 18 In the method shown in the figure, during the SDT process between the UE and the network device, when the UE obtains a second data packet, the UE can trigger the reporting of a BSR. The UE can timely notify the network device of the arrival of a new data packet through the BSR, and notify the network device whether the new data packet is a large data packet or a small data packet through BSRs with different contents. When the new data packet is a small data packet, the network device can dynamically schedule first transmission resources for the UE so that the UE uses the first transmission resources to send the new data packet, that is, the UE can continue to transmit small data packets in the non-connected state. When the new data packet is a large data packet, the network device instructs the UE to enter the RRC connected state so that the UE can send the large data packet in the RRC connected state. The UE does not need to initiate a new RA or SDT, saving transmission resources and avoiding unnecessary signaling overhead and power consumption. At the same time, without affecting the transmission delay of the first data packet, the transmission delay of the second data packet is reduced.

[0364] In a possible implementation, since the UE is mobile, the network device connected to the UE may change. Assume that the network device originally connected to the UE is the first device, and the first device configures an inactive SR for the UE (i.e., the first SR, optionally, and the second SR). The network device connected to the UE changes, that is, it switches from the first device to the second device. Then the second device can interact with the first device through the Xn interface to obtain the UE context information and capability information of the UE. The capability information of the UE may include whether the UE supports inactive SR. Not limited to the above-listed situations, in a specific implementation, the second device can also interact with the first device through the Xn interface to obtain the inactive SR configuration information, inactive SR resource configuration information, etc. of the UE. The specific process example is as follows Figures 19 - 20 shown.

[0365] Please refer to Figure 19 , Figure 19 which exemplarily shows a schematic diagram of a process for obtaining the capability information of a UE. This method can be applied to the Figure 1 communication system shown in the figure. The first device and the second device in this method can be Figure 1The network device 120 shown, the UE can be Figure 1 the UE130 shown. The method includes but is not limited to the following steps:

[0366] S1401: The UE obtains a first data packet.

[0367] S1402: The UE sends an RRC request message and the first data packet to a second device.

[0368] Specifically, when the first data packet obtained by the UE is small packet data, the UE initiates SDT. For example, if the SDT is 4step - SDT, then S1402 is the step of sending msg3. Or if the SDT is 2step - SDT, then S1402 is the step of sending msgA.

[0369] Before S1401, the method further includes: The UE connects to a first device, the UE cancels the connection with the first device and connects to a second device. That is to say, the network device to which the UE is connected can be switched from the first device to the second device.

[0370] S1403: The second device sends a retrieve UE context request message to the first device.

[0371] Specifically, the retrieve UE context request message can be used to request to obtain the UE context information and capability information of the UE. The capability information of the UE can include whether the UE supports inactive SR.

[0372] Exemplarily, a first information element (IE) is added to the retrieve UE context request message, and the first IE is used to request to obtain the capability information of the UE. When the value of the first IE is different, it is used to indicate whether to request to obtain the capability information of the UE. For example, the value of the first IE is 0 or 1, or the value is true or false. A value of 1 or true indicates a request to obtain the capability information of the UE, and a value of 0 or false indicates that the request to obtain the capability information of the UE is not made. Without limitation, it can also be indicated whether to request to obtain the capability information of the UE by whether the first IE is carried. When the retrieve UE context request message carries the first IE, it indicates a request to obtain the capability information of the UE, and when the first IE is not carried, it indicates that the request to obtain the capability information of the UE is not made.

[0373] S1404: The first device sends a retrieve UE context response message to the second device.

[0374] Specifically, the retrieve UE context response message may include the UE context information and capability information of the UE. The retrieve UE context response message may be a message sent by the first device to the second device when the first device obtains the UE context information of the UE.

[0375] Exemplarily, a second IE is added to the retrieve UE context request message. When the value of the second IE is different, it is used to indicate whether the UE supports inactive SR. For example, the value of the second IE is 0 or 1, or the value is true or false. A value of 1 or true indicates that the UE supports inactive SR, and a value of 0 or false indicates that the UE does not support inactive SR. Without limitation, it can also be indicated whether the UE supports inactive SR by whether the second IE is carried. When the retrieve UE context request message carries the second IE, it indicates that the UE supports inactive SR, and when the second IE is not carried, it indicates that the UE does not support inactive SR.

[0376] S1405: After the second device obtains the UE context of the UE, a path switch process is performed with the core network.

[0377] S1406: The second device sends a first data packet to the core network.

[0378] Specifically, the second device obtains the UE context information and capability information of the UE according to the retrieve UE context request message. After the second device obtains the UE context information, it can perform a path switch with the core network, and subsequently, the second device can forward the data packet sent by the UE to the core network.

[0379] S1407: The second device sends a first response message to the UE.

[0380] Specifically, the first response message is an RRC response message, for example, an RRC Release message. For specific details, please refer to the description of the RRC response message above. Figure 5 In some embodiments, if the first device obtains that the UE supports inactive SR, the second device may configure inactive SR for the UE through the first response message (such as the above-mentioned first SR and second SR).

[0381] S1408: The second device sends a UE context release message to the first device.

[0382] Specifically, the second device requests the first device to release the UE context of the UE through the UE context release message. After the first device releases the UE context, the first device cannot forward the data sent by the UE to the core network.

[0383] Please refer to Figure 20 , Figure 20 Exemplarily shown is another schematic flowchart of obtaining the capability information of the UE. This method can be applied to Figure 1 the communication system shown. The first device and the second device in this method can be Figure 1 the network device 120 shown. The UE can be Figure 1 the UE130 shown. This method includes but is not limited to the following steps:

[0384] S1501: The UE obtains the first data packet.

[0385] S1502: The UE sends an RRC request message and the first data packet to the second device.

[0386] S1503: The second device sends a retrieve UE context request message to the first device.

[0387] Specifically, S1501 - S1503 is the same as Figure 19 the above S1401 - S1403 and will not be elaborated here.

[0388] S1504: The first device sends a retrieve UE context failure message to the second device.

[0389] Specifically, the retrieve UE context failure message may include the capability information of the UE. The retrieve UE context failure message may be a message sent by the first device when it fails to obtain the UE context information of the UE. Optionally, the retrieve UE context failure message may include the reason for the failure to obtain the UE context information. An example of the retrieve UE context failure message indicating whether the UE supports inactive SR is the same as the above Figure 19The example in S1404 of the retrieve UE context request message indicating whether the UE supports inactive SR is similar and will not be elaborated here.

[0390] S1505: The second device sends a first data packet to the first device.

[0391] S1506: The first device sends the first data packet to the core network.

[0392] Specifically, the second device can obtain the UE's capability information (such as inactive SR information) based on the retrieve UE context failure message. If the second device fails to restore the UE context of the UE, it cannot forward the first data packet sent by the UE to the core network. In this case, the second device can send the first data packet to the first device so that the first device forwards the first data packet to the core network.

[0393] S1507: The second device sends a first response message to the UE.

[0394] Specifically, the first response message is an RRC response message, such as an RRCRelease message. For details, please refer to the Figure 5 description of the RRC response message above.

[0395] In a possible implementation, the UE can release the inactive SR configured by the network device for the UE, specifically, it can release the configuration information of the inactive SR and / or the resource configuration information of the inactive SR. For the description of this configuration information and resource configuration information, please refer to the Figure 4 description of the SR configuration information and SR resource configuration information above. The situations where the UE releases the inactive SR include, but are not limited to: the UE performs cell reselection, the UE receives an RRC response message (such as an RRCRelease message) sent by the network device, and fails to maintain uplink synchronization (i.e., TAT does not keep running), etc. Among them, after receiving the RRC response message, the UE can, but is not limited to, enter the RRC CONNECTED state and determine that the SDT process ends, etc. For the specific description of the RRC response message, please refer to the Figure 5 description of the RRC response message above.

[0396] Exemplarily, when the UE does not perform cell reselection or switch the connected network device, if the UE meets the above conditions for releasing the UE inactive SR, it can only release the resource configuration information of the inactive SR, but does not release the configuration information of the inactive SR. Alternatively, the UE can release the configuration information of the inactive SR and the resource configuration information of the inactive SR.

[0397] Exemplarily, when the UE performs cell reselection or switches the connected network device, the UE can release the configuration information of the inactive SR and the resource configuration information of the inactive SR.

[0398] In a possible implementation, the inactive SR configured by the network device for the UE may include multiple sets of resources for transmitting the inactive SR, simply referred to as inactive SR resources. And each set of inactive SR resources may correspond to at least one beam. Alternatively, the inactive SR configured by the network device for the UE may include multiple sets of inactive SR configurations, simply referred to as inactive SR configurations. And each set of inactive SR configurations may correspond to at least one beam. When the UE sends the inactive SR to the network device, the network device can determine, based on the inactive SR resources or inactive SR configurations corresponding to the inactive SR (such as the SR configuration ID), that at least one beam corresponding to the inactive SR is a beam with better quality for the UE to receive downlink data currently, so as to achieve beam update for the UE in the non-connected state. Subsequently, the network device can send downlink data to the UE based on at least this one beam. The UE does not need to specifically report the reference signal receiving power (RSRP) of the beam to the network device, and the network device can obtain the beam with better quality for the UE to receive downlink data currently, thereby reducing unnecessary signaling overhead and power consumption.

[0399] It can be understood that, combined with the Figures 5 - 8 SDT shown above, the situation where the first data packet transmitted in the ongoing SDT is a downlink small packet data is similar to the situation where the first data packet is an uplink data packet.

[0400] Exemplarily, assume that the UE and the network device are performing 4-step SDT, and the first data packet transmitted in this SDT is downlink small packet data. If the UE obtains a new second data packet before sending msg3, such as Figure 6After S201 and before S203 as shown. When the second data packet is a small packet of data, the UE can directly send the second data packet in msg3. The UE can trigger the reporting of a BSR. When the second data packet is a large packet of data, if there is BSR resource, the UE can report the BSR. For the specific process, please refer to the above Figures 17 - 18 above. If there is no BSR resource, the UE can trigger the reporting of an inactive SR. If there is a resource for sending an inactive SR, the UE can send a second SR to the network device. For the specific process, please refer to the above Figure 11 above. If there is no resource for sending an inactive SR, the UE can initiate a new RA. For the specific process, please refer to the above Figure 14 above.

[0401] If the UE obtains a new second data packet after sending msg3, for example, after S203 and before S205 as shown above Figure 6 above. The UE can trigger the reporting of a BSR. When the second data packet is a small packet of data, if there is BSR resource, the UE can report the BSR. For the specific process, please refer to the above Figures 17 - 18 above. If there is no BSR resource, the UE can trigger the reporting of an inactive SR. If there is a resource for sending an inactive SR, the UE can send a first SR to the network device. For the specific process, please refer to the above Figure 10 above. When the second data packet is a large packet of data, if there is BSR resource, the UE can report the BSR. For the specific process, please refer to the above Figures 17 - 18 above. If there is no BSR resource, the UE can trigger the reporting of an inactive SR. If there is a resource for sending an inactive SR, the UE can send a second SR to the network device. For the specific process, please refer to the above Figure 11 above. If there is no resource for sending an inactive SR, the UE can initiate a new RA. For the specific process, please refer to the above Figure 14 above.

[0402] Exemplarily, assume that the UE and the network device are performing 2-step SDT, and the first data packet transmitted in this SDT is a downlink small packet of data. If the UE obtains a new second data packet, for example, after S401 and before S403 as shown above Figure 8 above. The UE can trigger the reporting of a BSR. If there is BSR resource, the UE can report the BSR. For the specific process, please refer to the above Figures 17 - 18 above. If there is no BSR resource, the UE can trigger the reporting of an inactive SR. When the second data packet is a small packet of data, if there is a resource for sending an inactive SR, the UE can send a first SR to the network device. For the specific process, please refer to the above Figure 12When the second data packet is a large packet of data, if there are resources for sending an inactive SR, the UE can send a second SR to the network device. For the specific process, please refer to the above Figure 13 If there are no resources for sending an inactive SR, the UE can initiate a new RA. For the specific process, please refer to the above Figure 15 。

[0403] In this application, when the UE and the network device are performing SDT, examples of scenarios where the UE obtains a new data packet are as follows:

[0404] Example 1: The first UE and the second UE can be smart phones, and social applications can be installed on both the first UE and the second UE. The network device can be connected to the application server of the social application. Without limitation, the network device can be the application server of the social application. The first UE in the disconnected state can receive a first operation of the user based on the social application. The first operation is used to send the first text information input by the user to the second UE. The first text information is the first data packet, and the first data packet is a small packet of data. The first UE can initiate SDT based on RA to send the first data packet to the network device. The network device sends the first data packet to the application server of the social application, and then the application server of the social application sends the first data packet to the second UE. However, when the first UE performs the above SDT based on RA, the first UE receives a second operation of the user based on the social application. The second operation is used to send the second text information input by the user to the second UE. The second text information is the second data packet, and the second data packet is also a small packet of data. At this time, reporting a BSR can be triggered, but there are no BSR resources, and reporting an inactive SR can be triggered. Then the first UE can send a first SR to the network device. The network device can dynamically schedule uplink resources for the first UE in response to the first SR. The UE can send the second data packet to the network device based on the uplink resources. The network device sends the second data packet to the application server of the social application, and then the application server of the social application sends the second data packet to the second UE.

[0405] Alternatively, when the first UE performs the above RA-based SDT, the first UE receives a third operation of the user based on a social application, and the third operation is used to send a video file to the second UE. The video file is the second data packet, and the second data packet is a large packet of data. Then the first UE may send a second SR to the network device, and the network device may instruct the first UE to enter the RRC CONNECTED state in response to the second SR. Alternatively, the first UE may initiate a new RA to the network device to enter the RRC CONNECTED state in this way. The first UE in the RRC CONNECTED state then sends the second data packet to the network device, and the network device sends the second data packet to the application server of the social application, and then the application server of the social application sends the second data packet to the second UE.

[0406] Example 2: The UE is a smart bracelet, and the UE may be installed with an application for recording motion data or health data (abbreviated as a health application). The network device may be connected to the application server of the health application. Without limitation, the network device may be the application server of the health application. When the user uses the UE, the UE in the non-connected state may periodically send location information to the network device, and the location information is the first data packet. The first data packet is a small packet of data. The UE may initiate an RA-based SDT to the network device to send the first data packet to the network device. However, when the UE performs the above RA-based SDT, the UE receives a third operation of the user based on the health application, and the third operation is used to upload the user's motion data or health data to the application server of the health application. The user's motion data or health data is the second data packet, and the second data packet is a large packet of data. At this time, reporting a BSR may be triggered, but there is no BSR resource, and reporting an inactive SR may be triggered. Then the first UE may send a second SR to the network device. The network device may instruct the first UE to enter the RRC CONNECTED state in response to the second SR. Alternatively, the first UE may initiate a new RA to the network device to enter the RRC CONNECTED state in this way. The first UE in the RRC CONNECTED state then sends the second data packet to the network device, and the network device sends the second data packet to the application server of the health application.

[0407] The application scenarios are not limited to those listed above. In specific implementations, if the UE is a smart phone, the small packet data may be, for example: instant messaging messages, push messages of applications, heartbeat packets of applications, and indication messages for keeping the applications active. If the UE is not a smart phone, for example, the UE is a wearable device such as a smart bracelet or a smart watch, the small packet data may be, for example, periodically sent location information. For example, if the UE is a sensor such as a temperature sensor or a pressure sensor or is in an industrial wireless sensor network, the small packet data may be, for example, periodically sent or triggered detection signals (such as temperature and pressure values). For example, if the UE is a smart meter such as a smart electricity meter or is in a smart meter network, the small packet data may be, for example, periodically sent readings.

[0408] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by computer programs related to the hardware. The computer programs can be stored in a computer-readable storage medium. When the computer programs are executed, they may include the processes of the above method embodiments. The foregoing storage medium includes: various media that can store computer program codes such as read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs.

Claims

1. A data transmission method, characterized in that, applied to a terminal, the terminal being in a non-connected state, the method comprising: the terminal obtains a first data packet, the first data packet being small packet data; the terminal and a network device perform a small packet data transmission process; the small packet data transmission process includes the terminal sending a random access preamble, the first data packet, and a radio resource control (RRC) request message to the network device, and the terminal receiving an RRC response message sent by the network device; during the small packet data transmission process, the terminal obtains a second data packet; if the second data packet is small packet data, the terminal sends a first scheduling request (SR) to the network device, the first SR being used to request scheduling resources; the terminal receives first transmission resources scheduled by the network device in response to the first SR for the terminal; the terminal uses the first transmission resources to send the second data packet to the network device.

2. The method according to claim 1, characterized in that, the first SR is used to request scheduling resources for the small packet data, and the method further comprises: if the second data packet is large packet data, the terminal sends a second SR to the network device, the second SR being used to request scheduling resources for the large packet data, and the RRC response message in the small packet data transmission process is sent by the network device in response to the second SR; the terminal enters the RRC connected state in response to the RRC response message; the terminal sends the second data packet to the network device.

3. The method according to claim 1, characterized in that, the method further comprises: if the second data packet is large packet data, the terminal performs a random access process; the terminal enters the RRC connected state based on the random access process; the terminal sends the second data packet to the network device.

4. The method according to claim 3, characterized in that, the terminal and the network device perform a random access process, including: the terminal interrupts the small packet data transmission process and performs the random access process; after the terminal enters the RRC connected state based on the random access process, the method further comprises: the terminal sends the first data packet to the network device.

5. The method according to claim 2, characterized in that, the method further comprises: in a case where the terminal does not have resources to send a buffer status report (BSR) to the network device, the terminal triggers reporting the first SR or the second SR.

6. The method according to any one of claims 1-3, characterized in that, when the terminal and the network device perform the small packet data transmission process, the terminal resumes a data radio bearer (DRB) for transmitting small packet data and a DRB for transmitting large packet data.

7. The method according to claim 2, characterized in that, The logical channel corresponding to the first SR is the logical channel included in the first DRB, where the first DRB is a DRB for transmitting small packet data. The logical channel corresponding to the second SR is the logical channel included in the second DRB, where the second DRB is a DRB for transmitting large packet data.

8. The method according to claim 2, wherein, when the terminal sends the first SR to the network device, the terminal maintains uplink synchronization, and / or when the terminal sends the second SR to the network device, the terminal maintains uplink synchronization.

9. The method according to claim 2, wherein, before the terminal and the network device perform the small packet data transmission process, the method further includes: the terminal receives a configuration message sent by the network device, where the configuration message includes information about the first SR and the second SR; the terminal determines that the information about the first SR and the second SR becomes effective; or, before the terminal and the network device perform the small packet data transmission process, the method further includes: the terminal receives a configuration message sent by the network device, where the configuration message includes information about the first SR and the second SR; the terminal receives an effectiveness message sent by the network device, where the effectiveness message is used to indicate that the information about the first SR and the second SR becomes effective; wherein, the information about the first SR and the second SR includes the configuration information of the first SR and the second SR, and the resource information of the first SR and the second SR.

10. The method according to claim 9, wherein, the method further includes: when a preset condition is satisfied, the terminal releases the configuration information of the first SR and the second SR, and / or the resource information of the first SR and the second SR; the preset condition includes at least one of the following: the terminal performs cell reselection, the terminal does not maintain uplink synchronization, the terminal receives an RRC response message sent by the network device, and the RRC response message is used to indicate any one of the following: the terminal enters the RRC connected state, and the small packet data transmission process ends.

11. The method according to claim 2, wherein, the capability information of the first SR and the second SR is obtained by the network device from the network device to which the terminal was previously connected.

12. The method according to claim 1, wherein, the method further includes: the terminal determines a first beam, and the terminal determines the first SR according to the first beam; the first beam is the beam for the terminal to send the first SR to the network device, or the beam corresponding to the first SR; the network device is used to determine a second beam according to the first SR after receiving the first SR, and the second beam is the beam for the network device to send downlink data to the terminal; or, The method further includes: the terminal determines a first beam, and the terminal determines the second SR according to the first beam; the first beam is the beam for the terminal to send the second SR to the network device, or the beam corresponding to the second SR; the network device is configured to determine a second beam according to the second SR after receiving the second SR, and the second beam is the beam for the network device to send downlink data to the terminal.

13. A data transmission method, characterized in that, applied to a terminal, the terminal is in a non-connected state, and the method includes: the terminal obtains a first data packet; the first data packet is a small packet of data; the terminal and the network device perform a small packet data transmission process; the small packet data transmission process includes the terminal sending a random access preamble, the first data packet, and an RRC request message to the network device, and the terminal receiving an RRC response message sent by the network device; during the small packet data transmission process, the terminal obtains a second data packet; when the second data packet is a small packet of data, the terminal sends a first BSR to the network device to obtain first transmission resources scheduled by the network device in response to the first BSR for the terminal; the terminal uses the first transmission resources to send the second data packet to the network device.

14. The method according to claim 13, characterized in that, the first BSR includes a first field indicating obtaining transmission resources for small packet data, and the first BSR includes a second field indicating obtaining transmission resources for large packet data.

15. The method according to claim 14, characterized in that, the first field indicates a first logical channel group, the first logical channel group includes logical channels for transmitting small packet data, and the second field indicates a second logical channel group, the second logical channel group includes logical channels for transmitting large packet data.

16. A data transmission method, characterized in that, applied to a terminal, the terminal is in a non-connected state, and the method includes: the terminal obtains a first data packet, and the first data packet is a small packet of data; the terminal sends a random access preamble to the network device; the terminal obtains a second data packet; the terminal sends a third data packet, an RRC request message, and a first indication information to the network device, the first indication information is used to request scheduling resources; the third data packet is the data packet with a higher priority among the first data packet and the second data packet; the terminal receives first transmission resources scheduled by the network device in response to the first indication information for the terminal; the terminal uses the first transmission resources to send the second data packet to the network device.

17. The method according to claim 16, characterized in that, the priority of the terminal sending the third data packet is higher than the priority of the terminal sending the BSR, and the terminal sending the third data packet, the RRC request message, and the first indication information to the network device includes: In a case where the terminal does not send the resources of the BSR to the network device, the terminal sends the third data packet, the RRC request message, and the first indication information to the network device.

18. A data transmission method, characterized in that, applied to a network device, the method includes: The network device and a terminal in a non-connected state perform a small packet data transmission process; the small packet data transmission process includes the network device receiving a random access preamble, a first data packet, and an RRC request message sent by the terminal, and the network device sending an RRC response message to the terminal; the first data packet is small packet data obtained by the terminal; The network device receives a first SR sent by the terminal, where the first SR is sent by the terminal when a second data packet is small packet data, and the second data packet is obtained by the terminal during the small packet data transmission process; The network device schedules first transmission resources for the terminal in response to the first SR; The network device receives the second data packet sent by the terminal using the first transmission resources.

19. The method according to claim 18, characterized in that, the method further includes: The network device receives a second SR sent by the terminal, where the second SR is sent by the terminal when the second data packet is large packet data; the RRC response message in the small packet data transmission process is sent by the network device in response to the second SR, and the RRC response message is used to instruct the terminal to enter the RRC connected state; The network device receives the second data packet sent by the terminal in the RRC connected state.

20. The method according to claim 18, characterized in that, the method further includes: The network device receives the second data packet sent by the terminal in the RRC connected state, and the RRC connected state is entered by the terminal performing a random access process when the second data packet is large packet data.

21. The method according to any one of claims 18-20, characterized in that, when the terminal and the network device perform the small packet data transmission process, the terminal restores a data radio bearer DRB for transmitting small packet data and a DRB for transmitting large packet data.

22. The method according to claim 19, characterized in that, a logical channel corresponding to the first SR is a logical channel included in a first DRB, the first DRB is a DRB for transmitting small packet data, a logical channel corresponding to the second SR is a logical channel included in a second DRB, and the second DRB is a DRB for transmitting large packet data.

23. A data transmission method, characterized in that, applied to a network device, the method includes: The network device and a terminal in a non-connected state perform a small packet data transmission process; the small packet data transmission process includes the network device receiving a random access preamble, a first data packet, and an RRC request message sent by the terminal, and the network device sending an RRC response message to the terminal; the first data packet is small packet data obtained by the terminal; The network device receives a first BSR sent by the terminal, where the first BSR is sent by the terminal when the second data packet is small-packet data, and the second data packet is obtained by the terminal during the small-packet data transmission process; The network device schedules first transmission resources for the terminal in response to the first BSR; The network device receives the second data packet sent by the terminal using the first transmission resources.

24. The method according to claim 23, wherein, the first BSR includes a first field indicating obtaining transmission resources for small-packet data, and the first BSR includes a second field indicating obtaining transmission resources for large-packet data.

25. The method according to claim 24, wherein, the first field indicates a first logical channel group, the first logical channel group includes logical channels for transmitting small-packet data, and the second field indicates a second logical channel group, the second logical channel group includes logical channels for transmitting large-packet data.

26. A data transmission method, wherein, applied to a network device, the method includes: The network device receives a random access preamble sent by the terminal, where the random access preamble is sent by the terminal after obtaining a first data packet, and the first data packet is small-packet data; The network device receives a third data packet, an RRC request message, and first indication information sent by the terminal, where the first indication information is sent by the terminal after obtaining a second data packet, and the second data packet is small-packet data obtained by the terminal when sending or after sending the random access preamble to the network device; the third data packet is the data packet with a higher priority among the first data packet and the second data packet; The network device schedules first transmission resources for the terminal in response to the first indication information; The network device receives the second data packet sent by the terminal using the first transmission resources.

27. A user equipment, wherein, comprising a transceiver, a processor, and a memory, the memory is used to store a computer program, and the processor calls the computer program to execute the method according to any one of claims 1-17.

28. A network device, wherein, comprising a transceiver, a processor, and a memory, the memory is used to store a computer program, and the processor calls the computer program to execute the method according to any one of claims 18-26.

29. A computer storage medium, wherein, the computer storage medium stores a computer program, and when the computer program is executed by a processor, it implements the method according to any one of claims 1-17 or the method according to any one of claims 18-26.

Images