Message transmission method, and apparatus

Abstract

A message transmission method and an apparatus. In the message transmission method, a first network device receives a first request message from a second network device, the first request message being used for requesting context of a terminal device, the first request message comprising first indication information, the first indication information being used for indicating that the terminal device has initiated an SDT process in an RRC inactive state, and the first network device having already stored the context of the terminal device. If the volume of data to be transmitted during SDT of the terminal device is greater than or equal to a data volume threshold value, the first network device sends an RRC release message to the second network device, the RRC release message being used for instructing the terminal device to terminate the SDT process and maintain the RRC inactive state. When the terminal device has mass data to arrive during the SDT process, the method can avoid low transmission efficiency of mass data.

Description

Message transmission method and device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on September 22, 2023, with application number 202311247988.7 and application name “Message Transmission Method and Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a message transmission method and device. Background Art

[0003] In fifth-generation mobile communication technology (5G) networks, terminal devices may be in an inactive radio resource control (RRC) state. This RRC inactive state can save energy. If data arrives at a terminal device in an inactive RRC state, it can be transmitted via a small data transmission (SDT) process. During the SDT process, a large amount of data may arrive at the terminal device, and how to avoid inefficient transmission of large amounts of data is a technical issue that needs to be addressed.

[0004] Summary of the Invention

[0005] The embodiments of the present application provide a message transmission method and apparatus, which can avoid low transmission efficiency of a large amount of data when a large amount of data arrives at a terminal device during the SDT process.

[0006] In the first aspect, the present application provides a message transmission method, which can be applied to a first network device, a chip in the first network device, or a logic module or software that can realize all or part of the functions of the first network device. The following description is taken as an example of the first network device. The method includes: the first network device receives a first request message from the second network device, the first request message is used to request the context of the terminal device, the first request message includes first indication information, the first indication information is used to indicate that the terminal device has initiated an SDT process in an RRC inactive state, and the first network device has saved the context of the terminal device. If the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold, an RRC release message is sent to the second network device, and the RRC release message is used to instruct the terminal device to terminate the SDT process and maintain the RRC inactive state.

[0007] It can be seen that when a large amount of data arrives at the terminal device during the SDT process, if the large amount of data is still transmitted through the SDT process, the transmission efficiency of the large amount of data will be low. The message transmission method provided in the embodiment of the present application can promptly instruct the terminal device to terminate the SDT process, thereby avoiding the low transmission efficiency of the large amount of data. In addition, this method is also conducive to the terminal device that has terminated the SDT process and remains in the RRC inactive state to initiate the RRC recovery process, so that the terminal device transmits this large amount of data in the RRC connected state, thereby improving the transmission efficiency.

[0008] In an optional embodiment, the RRC release message also includes information for instructing the terminal device to immediately initiate an RRC recovery process, where the RRC recovery process is used by the terminal device to request to enter an RRC connected state and transmit data in the RRC connected state.

[0009] It can be seen that when the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data volume threshold, the first network device instructs the terminal device to immediately initiate the RRC recovery process, so that the terminal device transmits these large amounts of data in the RRC connection state, thereby improving transmission efficiency.

[0010] In an optional embodiment, the method further includes: the first network device receiving second indication information from the second network device, the second indication information being used to indicate that the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to a data amount threshold. Thus, the first network device determines, based on the received second indication information, that the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold.

[0011] Optionally, the second indication information is carried in a control plane message or a user plane message from the second network device.

[0012] In an optional embodiment, before the first network device receives the second indication information from the second network device, the method further includes: the first network device sending a data volume threshold to the second network device. This facilitates the second network device to determine the data volume threshold, and further determine whether the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to the data volume threshold.

[0013] Optionally, the data volume threshold is carried in a first response message sent to the second network device, and the first response message is used to indicate a partial context of the terminal device.

[0014] In an optional embodiment, the method further includes: the first network device sending a first response message to the second network device, the first response message including address information, the address information corresponding to third indication information, the third indication information being used to indicate the amount of data to be transmitted in the SDT of the terminal device. The first network device receives the third indication information from the second network device based on the address information. The first network device determines, based on the third indication information, that the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to a data amount threshold.

[0015] It can be seen that the first network device sends address information to the second network device, so that the first network device can determine the content and type of the third indication information based on the address information to determine the amount of data to be transmitted of the SDT of the terminal device, and then determine whether the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to the data amount threshold value.

[0016] Optionally, the first response message is used to indicate a partial context of the terminal device.

[0017] In a second aspect, the present application provides a message transmission method, which can be applied to a second network device, a chip in the second network device, or a logic module or software that can implement all or part of the functions of the second network device. The following description takes the second network device as an example. The method includes: the second network device sends a first request message to the first network device, the first request message is used to request the context of the terminal device, the first request message includes first indication information, the first indication information is used to indicate that the terminal device has initiated an SDT process in an RRC inactive state, and the first network device has saved the context of the terminal device. The second network device sends a second indication message to the first network device, the second indication information is used to indicate that the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to a data amount threshold. The second network device receives an RRC release message from the first network device, the RRC release message is used to instruct the terminal device to terminate the SDT process and maintain the RRC inactive state. The second network device sends an RRC release message to the terminal device.

[0018] It can be seen that when the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold, the second network device notifies the first network device of this situation, which is beneficial for the first network device to promptly instruct the terminal device to terminate the SDT process and maintain the RRC inactive state. When a large amount of data arrives at the terminal device during the SDT process, still transmitting a large amount of data through the SDT process will result in low transmission efficiency of a large amount of data. The message transmission method provided in the embodiment of the present application can promptly instruct the terminal device to terminate the SDT process, avoiding low transmission efficiency of a large amount of data. In addition, the method is also beneficial for the terminal device that has terminated the SDT process and maintained the RRC inactive state to initiate the RRC recovery process, so that the terminal device transmits these large amounts of data in the RRC connected state, thereby improving transmission efficiency.

[0019] In an optional embodiment, the RRC release message also includes information for instructing the terminal device to immediately initiate an RRC recovery process, where the RRC recovery process is used by the terminal device to request to enter an RRC connected state and transmit data in the RRC connected state.

[0020] It can be seen that when the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold, the terminal device is instructed to immediately initiate the RRC recovery process, so that the terminal device transmits these large amounts of data in the RRC connection state, thereby improving transmission efficiency.

[0021] In an optional embodiment, the second network device sending the second indication information to the first network device includes: the second network device determining a data volume threshold; or the second network device receiving the data volume threshold from the first network device. If the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data volume threshold, the second network device sending the second indication information to the first network device.

[0022] In an optional embodiment, the method further includes: the second network device receiving third indication information from the terminal device, the third indication information being used to indicate an amount of data to be transmitted in the SDT of the terminal device. This facilitates the second network device determining the amount of data to be transmitted in the SDT of the terminal device based on the third indication information, and further determining whether the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to a data amount threshold.

[0023] In an optional implementation, the data volume threshold value received by the second network device is carried in a first response message from the first network device, and the first response message is used to indicate a partial context of the terminal device.

[0024] In an optional implementation manner, the second indication information is carried in a control plane message or a user plane message sent to the first network device.

[0025] In a third aspect, the present application provides a message transmission method. The method can be applied to a second network device, a chip within the second network device, or a logic module or software that implements all or part of the second network device's functions. The following description uses the second network device as an example. The method comprises: the second network device sends a first request message to a first network device, the first request message being used to request a context for a terminal device. The first request message includes first indication information, the first indication information indicating that the terminal device has initiated an SDT process in an RRC inactive state and that the first network device has saved the terminal device's context. The second network device receives a first response message from the first network device, the first response message including address information corresponding to third indication information, the third indication information indicating the amount of data to be transmitted for the terminal device's SDT. Based on the address information, the second network device sends a third indication information to the first network device. The second network device receives an RRC release message from the first network device, the RRC release message being used to instruct the terminal device to terminate the SDT process and remain in an RRC inactive state. The second network device sends an RRC release message to the terminal device.

[0026] It can be seen that the second network device sends the third indication information to the first network device based on the address information; it is beneficial for the first network device to determine the content and type of the third indication information based on the address information to determine the amount of data to be transmitted in the SDT of the terminal device, thereby determining whether the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold value. This is further beneficial for the first network device to promptly instruct the terminal device to terminate the SDT process and maintain the RRC inactive state when the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold value. When a large amount of data arrives at the terminal device during the SDT process, the large amount of data is still transmitted through the SDT process, which will result in low transmission efficiency of the large amount of data. The message transmission method provided in the embodiment of the present application can promptly instruct the terminal device to terminate the SDT process, thereby avoiding low transmission efficiency of the large amount of data. In addition, the method is also beneficial for the terminal device that has terminated the SDT process and maintained the RRC inactive state to initiate the RRC recovery process, so that the terminal device transmits these large amounts of data in the RRC connection state, thereby improving transmission efficiency.

[0027] In an optional embodiment, the RRC release message also includes information for instructing the terminal device to immediately initiate an RRC recovery process, where the RRC recovery process is used by the terminal device to request to enter an RRC connected state and transmit data in the RRC connected state.

[0028] It can be seen that when the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold, instructing the terminal device to immediately initiate the RRC recovery process is conducive to enabling the terminal device to transmit a large amount of data in the RRC connection state and improve transmission efficiency.

[0029] In an optional implementation, the first response message is used to indicate a partial context of the terminal device.

[0030] In a fourth aspect, the present application further provides a communication device. The communication device may be a first network device or a second network device, or a chip in the first network device or the second network device, or a logic module or software capable of implementing all or part of the functions of the first network device or the second network device. The communication device has the function of implementing part or all of the embodiments described in any of the first to third aspects above. The functions may be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more units or modules corresponding to the above functions.

[0031] In one possible design, the communication device may include a processing unit and a communication unit, wherein the processing unit is configured to support the communication device in performing the corresponding functions of the above method. The communication unit is used to support communication between the communication device and other communication devices. The communication device may also include a storage unit, which is coupled to the processing unit and the communication unit and stores program instructions and data necessary for the communication device. In addition, the processing unit may be used to control the communication unit to transmit and receive data / signaling.

[0032] In one embodiment, the communication unit is used to receive a first request message from a second network device, the first request message is used to request the context of the terminal device, the first request message includes first indication information, the first indication information is used to indicate that the terminal device has initiated an SDT process in an RRC inactive state, and the communication device has saved the context of the terminal device.

[0033] The communication unit is also used to: if the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold, send an RRC release message to the second network device, and the RRC release message is used to instruct the terminal device to terminate the SDT process and maintain the RRC inactive state.

[0034] In addition, in this aspect, other optional implementations of the communication device can refer to the relevant content of the first aspect above and will not be described in detail here.

[0035] In another embodiment, the communication unit is used to send a first request message to the first network device, the first request message is used to request the context of the terminal device, the first request message includes first indication information, the first indication information is used to indicate that the terminal device has initiated an SDT process in an RRC inactive state, and the first network device has saved the context of the terminal device.

[0036] The communication unit is also used to send second indication information to the first network device, where the second indication information is used to indicate that the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to a data amount threshold.

[0037] The communication unit is also used to receive an RRC release message from the first network device, where the RRC release message is used to instruct the terminal device to terminate the SDT process and maintain an RRC inactive state.

[0038] The communication unit is also used to send an RRC release message to the terminal device.

[0039] In addition, in this aspect, other optional implementations of the communication device can refer to the relevant content of the second aspect above and will not be described in detail here.

[0040] In another embodiment, the communication unit is used to send a first request message to the first network device, the first request message is used to request the context of the terminal device, the first request message includes first indication information, the first indication information is used to indicate that the terminal device has initiated an SDT process in an RRC inactive state, and the first network device has saved the context of the terminal device.

[0041] The communication unit is also used to receive a first response message from the first network device, the first response message includes address information, the address information corresponds to the third indication information, and the third indication information is used to indicate the amount of data to be transmitted of the SDT of the terminal device.

[0042] The communication unit is further configured to send third indication information to the first network device according to the address information.

[0043] The communication unit is also used to receive an RRC release message from the first network device, where the RRC release message is used to instruct the terminal device to terminate the SDT process and maintain an RRC inactive state.

[0044] The communication unit is also used to send an RRC release message to the terminal device.

[0045] In addition, in this aspect, other optional implementations of the communication device can refer to the relevant content of the third aspect above and will not be described in detail here.

[0046] As an example, the communication unit may be a transceiver or a communication interface, the storage unit may be a memory, and the processing unit may be a processor. The processor is coupled to the memory, the memory being used to store programs or instructions to the processor, and the processor being used to cause the communication device to perform the method described in any one of the first to third aspects above when the programs or instructions are executed by the processor. The transceiver or communication interface may be used to transmit and receive signals and / or data.

[0047] In one embodiment, the transceiver is used to receive a first request message from a second network device, the first request message is used to request the context of the terminal device, the first request message includes first indication information, the first indication information is used to indicate that the terminal device has initiated an SDT process in an RRC inactive state, and the communication device has saved the context of the terminal device.

[0048] The transceiver is also used to: if the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold, send an RRC release message to the second network device, and the RRC release message is used to instruct the terminal device to terminate the SDT process and maintain the RRC inactive state.

[0049] In addition, in this aspect, other optional implementations of the communication device can refer to the relevant content of the first aspect above and will not be described in detail here.

[0050] In another embodiment, the transceiver is used to send a first request message to the first network device, the first request message is used to request the context of the terminal device, the first request message includes first indication information, the first indication information is used to indicate that the terminal device has initiated an SDT process in an RRC inactive state, and the first network device has saved the context of the terminal device.

[0051] The transceiver is also used to send second indication information to the first network device, where the second indication information is used to indicate that the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to a data amount threshold.

[0052] The transceiver is also used to receive an RRC release message from the first network device, where the RRC release message is used to instruct the terminal device to terminate the SDT process and maintain an RRC inactive state.

[0053] The transceiver is also used to send an RRC release message to the terminal device.

[0054] In addition, in this aspect, other optional implementations of the communication device can refer to the relevant content of the second aspect above and will not be described in detail here.

[0055] In another embodiment, the transceiver is used to send a first request message to the first network device, the first request message is used to request the context of the terminal device, the first request message includes first indication information, the first indication information is used to indicate that the terminal device has initiated an SDT process in an RRC inactive state, and the first network device has saved the context of the terminal device.

[0056] The transceiver is also used to receive a first response message from the first network device, the first response message includes address information, the address information corresponds to the third indication information, and the third indication information is used to indicate the amount of data to be transmitted of the SDT of the terminal device.

[0057] The transceiver is further configured to send third indication information to the first network device according to the address information.

[0058] The transceiver is also used to receive an RRC release message from the first network device, where the RRC release message is used to instruct the terminal device to terminate the SDT process and maintain an RRC inactive state.

[0059] The transceiver is also used to send an RRC release message to the terminal device.

[0060] In addition, in this aspect, other optional implementations of the communication device can refer to the relevant content of the third aspect above and will not be described in detail here.

[0061] In another embodiment, the communication device is a chip or a chip system. The processing unit may also be embodied as a processing circuit or a logic circuit; and the transceiver unit may be an input / output interface, an interface circuit, an output circuit, an input circuit, a pin, or a related circuit on the chip or chip system.

[0062] During implementation, the processor can be used to perform, for example, but not limited to, baseband-related processing, and the transceiver or communication interface can be used to perform, for example, but not limited to, radio frequency transceiver. The above-mentioned devices can be provided on separate chips, or at least partially or entirely on the same chip. For example, the processor can be further divided into an analog baseband processor and a digital baseband processor. The analog baseband processor can be integrated with the transceiver (or communication interface) on the same chip, while the digital baseband processor can be provided on a separate chip. With the continuous development of integrated circuit technology, more and more devices can be integrated on the same chip. For example, a digital baseband processor can be integrated with multiple application processors (such as, but not limited to, a graphics processor, a multimedia processor, etc.) on the same chip. Such a chip can be called a system on a chip (SoC). Whether each device is provided independently on different chips or integrated on one or more chips often depends on the needs of the product design. The embodiments of the present application do not limit the implementation form of the above-mentioned devices.

[0063] In a fifth aspect, the present application also provides a processor for executing the various methods described above. In the process of executing these methods, the process of sending the above-mentioned signal and receiving the above-mentioned signal in the above-mentioned method can be understood as the process of outputting the above-mentioned signal by the processor, and the process of inputting the above-mentioned signal by the processor. When outputting the above-mentioned signal, the processor outputs the above-mentioned signal to the transceiver so that it is transmitted by the transceiver (or communication interface). After being output by the processor, the above-mentioned signal may also need to undergo other processing before reaching the transceiver (or communication interface). Similarly, when the processor receives the above-mentioned input signal, the transceiver (or communication interface) receives the above-mentioned signal and inputs it into the processor. Furthermore, after the transceiver (or communication interface) receives the above-mentioned signal, the above-mentioned signal may need to undergo other processing before being input into the processor.

[0064] For the sending and receiving operations involved in the processor, unless otherwise specified, or unless they conflict with their actual functions or internal logic in the relevant descriptions, they can be more generally understood as processor output, reception, input and other operations, rather than sending and receiving operations directly performed by the RF circuit and antenna.

[0065] During implementation, the processor may be a processor specifically configured to execute these methods, or may be a processor that executes computer instructions in a memory to execute these methods, such as a general-purpose processor. The memory may be a non-transitory memory, such as a read-only memory (ROM), which may be integrated with the processor on the same chip or disposed on separate chips. The embodiments of the present application do not limit the type of memory or the configuration of the memory and the processor.

[0066] In a sixth aspect, the present application further provides a communication system, comprising at least one first network device and at least one second network device according to the above aspects. In another possible design, the system may further include other devices that interact with the first network device and / or the second network device in the solution provided by the present application.

[0067] In a seventh aspect, the present application provides a computer-readable storage medium storing a computer program. When the computer program is run, the method described in any one of the first to third aspects above is executed.

[0068] In an eighth aspect, the present application further provides a computer program product comprising instructions, the computer program product comprising: computer program code, which, when the computer program code is run, enables the method described in any one of the above-mentioned first to third aspects to be executed.

[0069] In a ninth aspect, the present application provides a chip system, which includes a processor and an interface, wherein the interface is used to obtain a program or instruction, and the processor is used to call the program or instruction to implement the functions involved in any one of the first to third aspects. In one possible design, the chip system also includes a memory, which is used to store program instructions and data necessary for the terminal. The chip system can be composed of a chip, or it can include a chip and other discrete devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] FIG1 is a schematic structural diagram of a communication system;

[0071] FIG2 is a schematic diagram of a 5G system architecture;

[0072] FIG3 is a schematic diagram of another 5G system architecture;

[0073] FIG4 is a schematic diagram of a gNB;

[0074] FIG5 is a schematic diagram of a 5G protocol stack;

[0075] FIG6 is a flow chart of a message transmission method provided in an embodiment of the present application;

[0076] FIG7 is a schematic diagram of another message transmission method provided in an embodiment of the present application;

[0077] FIG8 is a schematic diagram of another message transmission method provided in an embodiment of the present application;

[0078] FIG9 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0079] FIG10 is a schematic structural diagram of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0080] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0081] First, in order to better understand the message transmission method disclosed in the embodiment of the present application, a communication system to which the embodiment of the present application is applicable is described.

[0082] The technical solutions of the embodiments of the present application can be applied to various communication systems. For example, the Global System for Mobile Communications, the Long Term Evolution (LTE) system, the Universal Mobile Communications System, the fourth generation mobile communication technology (4G) system, the fourth and fifth generation mobile communication technology (4.5G) system, the fifth generation mobile communication technology (5G) system, and with the continuous development of communication technology, the technical solutions of the embodiments of the present application can also be used in subsequent evolved communication systems, such as the sixth generation mobile communication technology (6G) system, the seventh generation mobile communication technology (7G) system, and so on. Among them, the 5G system aims to increase data transmission speed, reduce latency, support more users, devices and services, and improve network efficiency. The three major application scenarios supported by the 5G system are: enhanced mobile broadband (eMBB), ultra-reliable low latency communication (URLLC), and massive machine type of communication (mMTC).

[0083] Please refer to Figure 1, which is a structural diagram of a communication system provided in an embodiment of the present application. The communication system includes a terminal device, a second network device, and a first network device. The terminal device can communicate with the second network device, and the second network device can communicate with the first network device. For example, taking the network device as a next-generation base station (next-generation NodeB, gNB) as an example, the second network device is the receiving gNB corresponding to the terminal device, and the first network device is the last serving gNB corresponding to the terminal device. In addition, the number and form of the devices shown in Figure 1 are for example only and do not constitute a limitation on the embodiments of the present application.

[0084] The following example describes the 5G system architecture. As shown in Figure 2, the 5G system architecture consists of a 5G core network (5th generation core, 5GC) and a 5G radio access network (NG-RAN). Network communication can be carried out between the NG-RAN and the 5GC. The radio access network (RAN) nodes in the NG-RAN include gNBs and ng-eNBs. The gNB provides the termination point for the user plane and control plane protocols of the new radio technology (NR), and the ng-eNB provides the termination point for the user plane and control plane protocol stack of the evolved universal mobile telecommunication system (UMTS) terrestrial radio access network (abbreviated as: E-UTRAN). In addition, gNBs are connected to each other, between gNBs and ng-eNBs, and between ng-eNBs and ng-eNBs via the Xn interface. The gNB and 5GC, as well as the ng-eNB and 5GC, are connected through the NG interface. Specifically, the gNB and the access and mobility management function (AMF) module, as well as the ng-eNB and AMF module are connected through the NG-C interface. The gNB and the user plane function (UPF) module, as well as the ng-eNB and UPF module are connected through the NG-U interface.

[0085] In one possible deployment, as shown in Figure 3, a gNB includes a gNB-centralized unit (CU) and multiple gNB-distributed units (DUs). The gNB-CU connects to the gNB-DUs via the F1 interface, and connects to other gNBs via the Xn-C interface. In another possible deployment, as shown in Figure 4, a gNB-CU includes a gNB-CU-control plane (CP) and multiple gNB-CU-user planes (UPs). The gNB-CU-CP connects to each gNB-CU-UP via the E1 interface, the gNB-CU-CP connects to the gNB-DUs via the F1-C interface, and each gNB-CU-UP connects to the gNB-DU via the F1-U interface.

[0086] As shown in Figure 5, the 5G system protocol stack includes the following layers: RRC, service data adaptation protocol (SDAP), packet data convergence protocol (PDCP), radio link control (RLC), medium access control (MAC), and physical (PHY). The following briefly describes the functions of each protocol layer.

[0087] The functions of the RRC layer include but are not limited to: controlling the PDCP layer, RLC layer, MAC layer and PHY layer, obtaining system messages, paging, mobility management, etc.

[0088] The SDAP layer directly carries Internet Protocol (IP) packets on the user plane. Its functions include, but are not limited to, mapping Quality of Service (QoS) flows to Data Radio Bearers (DRBs) and adding QoS flow indicators (QFIs) to packets.

[0089] The functions of the PDCP layer include but are not limited to: user IP header compression, encryption / decryption (for control plane / user plane data), data integrity protection / verification, data packet sorting, data packet replication, and traffic diversion.

[0090] The functions of the RLC layer include, but are not limited to, transparent mode (TM) (broadcast messages), unacknowledged mode (UM) (voice services with latency requirements), and acknowledged mode (AM) (normal services with high accuracy). The RLC layer also includes segmentation and reassembly, and error correction.

[0091] The functions of the MAC layer include, but are not limited to, resource scheduling, mapping between logical channels and transport channels, multiplexing / demultiplexing, and asynchronous uplink and downlink hybrid automatic repeat request (HARQ).

[0092] The functions of the PHY layer include but are not limited to error detection, forward error correction (FEC), rate matching, physical channel mapping, adjustment and demodulation, frequency synchronization and time synchronization, wireless measurement, and multiple-in multiple-out (MIMO) processing.

[0093] In the embodiment of the present application, the network device is any device with a wireless transceiver function or a chip that can be set in the device, and the network device includes but is not limited to: an evolved node B (eNB), a radio network controller (RNC), a node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home network device (for example, a home evolved Node B, or a home Node B, HNB), a baseband unit (BBU), an access point (AP) in a wireless fidelity (WIFI) system, a wireless relay node, a wireless backhaul node, a transmission and reception point (TRP or transmission point, TP), etc., and can also be a device used in a 4G, 5G or even 6G system, such as an evolved base station (NodeB or eNB or e-NodeB, evolutional Node B) in LTE, a next-generation LTE base station (next-generation eNodeB, ng-eNB), a next-generation base station (next-generation NR) in NR. A base station can be a NodeB (gNodeB, gNodeB, or gNB), a transceiver point or transmission point (TRP or TP), or a base station developed by the 3rd Generation Partnership Project (3GPP). Alternatively, it can be a network node that constitutes a gNB or transmission point, such as a baseband unit (BBU), a picocell, a femtocell, or a roadside unit (RSU) in smart driving scenarios. A base station can be a macro base station, a micro base station, a picocell, a small cell, a relay station, or a balloon base station. Network devices can also be servers, wearable devices, or in-vehicle devices.

[0094] The terminal device may also be referred to as user equipment (UE), terminal, access terminal, subscriber unit (SU), user station, mobile station, mobile station (MS), remote station, remote terminal, mobile device, user terminal, user agent or user device, and may be applied to 4G, 5G or even 6G systems. The terminal device in the embodiments of the present application may be a handheld device, a vehicle-mounted device, a wearable device, a computing device or other processing device connected to a wireless modem with wireless communication capabilities; the terminal device may be a terminal with a function of connecting to a cellular base station; the terminal device may also be a terminal in a WIFI system (i.e., a WIFI terminal), which has a function of connecting to a WIFI AP. For example, the terminal device may be a mobile phone, a cellular phone, a smart phone, a tablet computer, a computer with wireless transceiver capabilities, a wireless data card, a personal digital assistant (PDA), a tablet computer, a wireless modem, a handheld device, a laptop computer, a machine type communication (MTC) terminal, etc. The terminal device can also be a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a tactile terminal device, a vehicle-mounted terminal device, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, a wearable terminal device, and the like.

[0095] The central network (CN) is responsible for completing registration, connection, and session management. Core network elements include: authentication server function (AUSF), network exposure function (NEF), policy control function (PCF), unified data management (UDM), unified data repository (UDR), network repository function (NRF), application function (AF), AMF, session management function (SMF), and UPF.

[0096] The AUSF network element is primarily responsible for user authentication to determine whether a user or device is allowed to access the network. The NEF network element exposes the services and capabilities of 3GPP network functions to the AF network element, and also enables the AF network element to provide information to 3GPP network functions. The PCF network element manages charging and QoS policies. The UDM network element manages subscription data and user access authorization. The UDR network element accesses subscription data, policy data, application data, and other types of data. The NRF network element provides network element discovery, providing information specific to the network element type upon request from other network elements. The NRF network element also provides network element management services, such as registration, update, and deregistration of network elements, as well as subscription and push notification of network element status. The AF network element primarily communicates application-side requests to the network. The AMF network element primarily performs functions such as mobility management and access authentication / authorization. The AMF network element is also responsible for communicating user policies between terminal devices and the PCF network element. The SMF network element performs session management functions such as IP address allocation, UPF selection, and charging and QoS policy control for terminal devices. The UPF network element serves as the interface UPF with the data network, completing functions such as user plane data forwarding, session / flow-level billing statistics, and bandwidth limitation.

[0097] The following is a detailed description of the embodiments of the present application in conjunction with the accompanying drawings. The flowchart in this application uses the terminal device, the second network device, and the first network device as examples to illustrate the corresponding method, but this application does not limit the execution of the interactive diagram. For example, any device in the figure can also be a chip, chip system, or processor that supports the device to implement the corresponding method, or a logic module or software that can implement all or part of the functions of the device.

[0098] Please refer to Figure 6, which is a flow chart of a message transmission method provided in an embodiment of the present application. The message transmission method includes the following steps.

[0099] S101. A second network device sends a first request message to a first network device. The first request message is used to request a context of a terminal device. The first request message includes first indication information, which is used to indicate that the terminal device has initiated an SDT process in an RRC inactive state. Accordingly, the first network device receives the first request message from the second network device.

[0100] The first network device has saved the context of the terminal device. For example, the context of the terminal device includes the PDCP configuration and RLC configuration of the terminal device.

[0101] Understandably, when data arrives, the terminal device in the RRC inactive state initiates an RRC inactive SDT process to the second network device. The second network device then sends a first request message to the first network device to request the context of the terminal device, thereby facilitating SDT data transmission. Furthermore, in the embodiment of the present application, the first request message is, for example, a Retrieve UE Context request message.

[0102] For example, in a 5G network, a terminal device in an RRC inactive state has the following characteristics:

[0103] 1. The terminal device remains in the connection management (CM)-connected (CM-CONNECTED) state.

[0104] 2. The RRC connection is suspended.

[0105] 3. The terminal device can move within the area configured by NG-RAN without notifying NG-RAN.

[0106] 4. When the terminal device moves outside the configured RAN-based notification area (RNA), the terminal device will notify the NG-RAN through RNA update.

[0107] 5. NG-RAN can use the inactive radio network temporary identify (I-RNTI) configured by NG-RAN to page the terminal device.

[0108] In an optional embodiment, the terminal device initiates an SDT process in an RRC inactive state, including: the terminal device sends an RRC resume request message (i.e., RRC Resume Request) of SDT, as well as uplink SDT data (i.e., UL SDT data) and / or uplink SDT signaling to the second network device. The RRC resume request message of SDT includes an I-RNTI, which is used to identify the context of the terminal device. The second network device determines the first network device through the I-RNTI, and then the second network device executes step S101.

[0109] In an optional embodiment, after the first network device receives the first request message from the second network device, the method further includes: the first network device sends a first response message to the second network device, where the first response message is used to indicate a partial context of the terminal device; and accordingly, the second network device receives the first response message from the first network device. For example, the partial context of the terminal device includes an RLC configuration of the terminal device. In addition, in this embodiment of the present application, the first response message is, for example, a partial context transfer (i.e., a Partial UE Context transfer) message.

[0110] Optionally, after the first network device determines that the anchor point for executing the SDT process remains unchanged (i.e., SDT without anchor relocation), the first network device sends a first response message to the second network device. It is understandable that the message transmission method provided in the embodiment of the present application can be applied to the SDT process with a unchanged anchor point.

[0111] Optionally, after the second network device receives the first response message from the first network device, the method further includes: the second network device sending a confirmation message to the first network device, the confirmation message being used to indicate that the second network device confirms receipt of the partial context of the terminal device; and correspondingly, the first network device receives the confirmation message from the second network device. For example, the confirmation message is a partial context transfer acknowledgement message.

[0112] S102: If the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold, the first network device sends an RRC release message to the second network device. The RRC release message is used to instruct the terminal device to terminate the SDT process and maintain an RRC inactive state. Correspondingly, the second network device receives the RRC release message from the first network device.

[0113] In the embodiment of the present application, "if..." can also be understood as "in the case of..." For example, step S102 can also be understood as: the first network device sends an RRC release message to the second network device when the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold.

[0114] Optionally, the amount of data to be transmitted of the SDT of the terminal device may be the amount of uplink data to be transmitted of the SDT of the terminal device, such as the UL SDT data size to be transmitted by the terminal device or the amount of data in the buffer of the terminal device (for example, the amount of data indicated by the buffer status report (BSR)).

[0115] The following describes an optional manner in which the first network device determines whether the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to the data amount threshold, as described in the following optional implementations 1.1 and 1.2.

[0116] In implementation 1.1, the first network device determines, based on the second indication information, that the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to the data amount threshold value. The second indication information is sent by the second network device to the first network device, and the second indication information is used to indicate that the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to the data amount threshold value. In addition, the second indication information can also be referred to as an SDT data size threshold crossed message, for example.

[0117] Optionally, the method further includes: the second network device determining a data volume threshold value, or the second network device receiving the data volume threshold value from the first network device. The second network device compares the amount of data to be transmitted of the terminal device's SDT with the data volume threshold value to determine whether the amount of data to be transmitted of the terminal device's SDT is greater than or equal to the data volume threshold value. If the amount of data to be transmitted of the terminal device's SDT is greater than or equal to the data volume threshold value, the second network device sends second indication information to the first network device.

[0118] Optionally, before the second network device determines whether the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to a data amount threshold, the method further includes: the terminal device sends third indication information to the second network device, the third indication information being used to indicate the amount of data to be transmitted of the SDT of the terminal device; and correspondingly, the second network device receives the third indication information from the terminal device. The second network device determines the amount of data to be transmitted of the SDT of the terminal device based on the third indication information. For example, the third indication information is a BSR, which indicates data corresponding to one or more logical channel groups. The second network device sums the data of the multiple logical channel groups to determine the amount of data to be transmitted of the SDT of the terminal device.

[0119] Optionally, for the case where the data volume threshold value is sent by the first network device to the second network device, the data volume threshold value is carried in the first response message, and the first response message is used to indicate part of the context of the terminal device. For a detailed description of the first response message, please refer to the above-mentioned related description and will not be repeated here.

[0120] In an optional manner, the second indication information is carried in a control plane message sent by the second network device to the first network device. For example, the control plane message is a Retrieve UE Context Confirm message, which is used to request termination of the SDT process.

[0121] In another optional manner, the second indication information is carried in a user plane message sent by the second network device to the first network device. For example, the user plane message is assistance information data of protocol data unit (PDU) type 2 (i.e., PDU type 2). In addition, when the first network device is a CU-CP and CU-UP separated architecture, the second network device sends a user plane message to the CU-UP in the first network device, and the user plane message carries the second indication information, and then the CU-UP in the first network device sends the user plane message to the CU-CP.

[0122] In implementation 1.2, the first network device determines, based on third indication information, whether the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to a data amount threshold. The third indication information is sent by the second network device to the first network device, and is used to indicate the amount of data to be transmitted in the SDT of the terminal device.

[0123] Specifically, the first network device determines the amount of data to be transmitted of the SDT of the terminal device based on the third indication information. The first network device compares the amount of data to be transmitted of the SDT of the terminal device with the data amount threshold to determine whether the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to the data amount threshold.

[0124] Optionally, the method also includes: the first network device sends a first response message to the second network device, the first response message includes address information, and the address information corresponds to the third indication information; accordingly, the second network device receives the first response message from the first network device. The second network device receives the third indication information from the terminal device, and sends the third indication information to the first network device according to the address information; accordingly, the first network device receives the third indication information from the second network device according to the address information. It can be understood that the address information is used to transmit the third indication information, but not for transmitting user data and non-access stratum (NAS) signaling. In addition, for the specific explanation of the third indication information, please refer to the relevant explanation in Implementation 1.1, which will not be repeated here.

[0125] In addition, in the case where the first network device is a CU-CP and CU-UP separated architecture, the second network device sends the third indication information to the CU-UP of the first network device according to the address information, and then the CU-UP of the first network device sends the third indication information to the CU-CP.

[0126] Optionally, the second network device sends third indication information to the first network device based on the address information, including: the second network device sends the address information and the third indication information to the first network device. Correspondingly, the first network device receives the third indication information from the first network device based on the address information, including: the first network device receives the address information and the third indication information from the second network device. Because the address information and the third indication information correspond to each other, the first network device determines the content and type of the third indication information based on the received address information, thereby enabling the first network device to determine the amount of data to be transmitted in the SDT of the terminal device.

[0127] Optionally, the address information is a tunnel endpoint identifier (TEID).

[0128] Optionally, the data volume threshold is determined by the first network device itself or is predefined.

[0129] Optionally, the first response message is used to indicate a portion of the context of the terminal device. For a detailed description of the first response message, please refer to the aforementioned related description, which will not be repeated here.

[0130] S103. The second network device sends an RRC release message to the terminal device; accordingly, the terminal device receives the RRC release message from the second network device.

[0131] In an optional embodiment, the RRC release message also includes information for instructing the terminal device to immediately initiate an RRC recovery process, where the RRC recovery process is used for the terminal device to request to enter the RRC connection state and transmit data in the RRC connection state. It can be understood that the RRC recovery process is a non-SDT RRC recovery process. It can be seen that when the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold, the first network device instructs the terminal device to immediately initiate an RRC recovery process, so that the terminal device transmits these large amounts of data in the RRC connection state, thereby improving transmission efficiency.

[0132] S104. The terminal device terminates the SDT process and maintains the RRC inactive state.

[0133] In an optional implementation, after the terminal device receives the RRC release message from the first network device, the method further includes: the terminal device immediately initiating an RRC recovery process.

[0134] Specifically, the terminal device initiates an RRC recovery process, including: the terminal device sends an RRC recovery request (i.e., RRC resume request) message to the second network device (without sending uplink data), where the RRC recovery request message is used to request the restoration of the RRC connection; accordingly, the second network device receives the RRC recovery request message from the terminal device. The second network device sends an RRC recovery message to the terminal device, where the RRC recovery message is used to instruct the terminal device to restore the RRC connection; accordingly, the terminal device receives the RRC recovery message from the second network device. The terminal device restores the RRC connection to enter the RRC connected state, and the terminal device sends a large amount of data to the second network device in the RRC connected state.

[0135] To summarize, in this message transmission method, when the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold, the first network device sends an RRC release message to the second network device. The RRC release message is used to instruct the terminal device to terminate the SDT process and maintain an RRC inactive state. It can be seen that when a large amount of data arrives at the terminal device during the SDT process, a large amount of data is still transmitted through the SDT process, which will result in low transmission efficiency of a large amount of data. The message transmission method provided in the embodiment of the present application can promptly instruct the terminal device to terminate the SDT process, thereby avoiding low transmission efficiency of a large amount of data. In addition, the terminal device that has terminated the SDT process and maintains an RRC inactive state initiates an RRC recovery process, so that the terminal device transmits these large amounts of data in an RRC connected state, thereby improving transmission efficiency.

[0136] The embodiments of the present application also provide exemplary explanations of the message transmission methods using the above-mentioned implementation 1.1 and implementation 1.2 respectively.

[0137] Example 1: Using the first network device described in Implementation 1.1, the first network device determines, based on the second indication information, that the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to the data amount threshold. The second indication information is sent by the second network device to the first network device, and the second indication information is used to indicate that the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to the data amount threshold. An exemplary message transmission method is shown in FIG7 and includes the following steps:

[0138] S201: A terminal device sends an SDT RRC recovery request message, along with uplink SDT data and / or uplink SDT signaling, to a second network device. In response, the second network device receives the SDT RRC recovery request message, along with uplink SDT data and / or uplink SDT signaling, from the terminal device. The SDT RRC recovery request message includes an I-RNTI, which is used to identify a context of the terminal device.

[0139] S202: The second network device sends a first request message to the first network device; in response, the first network device receives the first request message from the second network device. The first request message is used to request a context of the terminal device, and the first request message includes first indication information, which is used to indicate that the terminal device has initiated an SDT process in an RRC inactive state.

[0140] In addition, before the second network device sends the first request message to the first network device, the method further includes: the second network device determining the first network device according to the I-RNTI.

[0141] S203: The first network device sends a first response message to the second network device; correspondingly, the second network device receives the first response message from the first network device, wherein the first response message is used to indicate a portion of the context of the terminal device.

[0142] S204: The second network device sends a confirmation message to the first network device; accordingly, the first network device receives the confirmation message from the second network device, wherein the confirmation message is used to indicate that the second network device confirms receipt of the partial context of the terminal device.

[0143] S205: The terminal device sends third indication information to the second network device; correspondingly, the second network device receives the third indication information from the terminal device, wherein the third indication information is used to indicate the amount of data to be transmitted of the SDT of the terminal device.

[0144] S206: The second network device determines whether the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold. If the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold, execute steps S207 to S211.

[0145] In an optional implementation, the data volume threshold is determined by the second network device itself. Alternatively, the data volume threshold is sent by the first network device to the second network device, for example, the data volume threshold is carried in the first response message in step S203.

[0146] S207: The second network device sends a second indication message to the first network device; correspondingly, the first network device receives the second indication message from the second network device, wherein the second indication message is used to indicate that the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to the data amount threshold.

[0147] S208: The first network device sends an RRC release message to the second network device; in response, the second network device receives the RRC release message from the first network device. The RRC release message is used to instruct the terminal device to terminate the SDT process and maintain an RRC inactive state.

[0148] In an optional embodiment, the RRC release message also includes information for instructing the terminal device to immediately initiate an RRC recovery process, where the RRC recovery process is used by the terminal device to request to enter an RRC connected state and transmit data in the RRC connected state.

[0149] S209: The second network device sends an RRC release message to the terminal device. Correspondingly, the terminal device receives the RRC release message from the second network device.

[0150] S210. The terminal device terminates the SDT process and maintains the RRC inactive state.

[0151] S211. The terminal device initiates the RRC recovery process.

[0152] For detailed description of steps S201 to S211, please refer to the relevant description in the message transmission method shown in FIG6 , which also has corresponding beneficial effects and will not be described in detail.

[0153] Example 2: Using the first network device described in Implementation 1.2, the first network device determines whether the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to a data volume threshold based on the third indication information. The third indication information is sent by the second network device to the first network device and is used to indicate the amount of data to be transmitted in the SDT of the terminal device. An exemplary message transmission method is shown in Figure 8.

[0154] As shown in the dotted box in FIG8 , the message transmission method shown in FIG8 differs from the message transmission method shown in FIG7 in that:

[0155] 1. In the message transmission method shown in FIG8 , the first response message transmitted in step S203 includes address information, and the address information corresponds to the third indication information, and the third indication information is used to indicate the amount of data to be transmitted of the SDT of the terminal device.

[0156] 2. The message transmission method shown in FIG8 does not include steps S206 and S207 in FIG7.

[0157] 3. In the message transmission method shown in FIG8 , after step S205 , steps S301 and S302 are further included:

[0158] S301: The second network device sends third indication information to the first network device according to address information. Correspondingly, the first network device receives the third indication information from the second network device according to the address information.

[0159] S302: The first network device determines whether the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold based on the third indication information. If the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold, execute steps S208 to S211.

[0160] In addition, for the specific description of each step in Figure 8, please refer to the relevant description in the message transmission method shown in Figure 6, which also has corresponding beneficial effects and will not be repeated here.

[0161] To implement the various functions of the methods provided in the embodiments of the present application, the first network device or the second network device may include hardware structures and / or software modules, and implement the aforementioned functions in the form of hardware structures, software modules, or a combination of hardware structures and software modules. Whether a particular one of the aforementioned functions is implemented in the form of hardware structures, software modules, or a combination of hardware structures and software modules depends on the specific application and design constraints of the technical solution.

[0162] As shown in Figure 9, an embodiment of the present application provides a communication device 900. The communication device 900 can be a first network device or a second network device, or can also be a component of the first network device (for example, an integrated circuit, a chip, etc.), or can also be a component of the second network device (for example, an integrated circuit, a chip, etc.). The communication device 900 can also be other communication units for implementing the method in the method embodiment of the present application. The communication device 900 may include a processing unit 901. Optionally, the communication device 900 may also include a communication unit 902, and the processing unit 901 is used to control the communication unit 902 to send and receive data / signaling. The communication unit 902 can also be referred to as a transceiver unit. Optionally, the communication unit 902 may include a sending unit and a receiving unit. The sending unit can be used to send data / signaling, and the receiving unit can be used to receive data / signaling. Optionally, the communication device 900 may also include a storage unit 903. The storage unit 903 can be used to store information and / or data and / or instructions, etc. The storage unit 903 can interact with the processing unit 901 and can also interact with the communication unit 902.

[0163] In one possible design, for a case where the communication apparatus 900 is used to implement the function of the first network device in the above method embodiment:

[0164] The communication unit 902 is used to receive a first request message from the second network device, where the first request message is used to request the context of the terminal device. The first request message includes first indication information, where the first indication information is used to indicate that the terminal device has initiated an SDT process in an RRC inactive state, and the communication device 900 has saved the context of the terminal device.

[0165] The communication unit 902 is also used to: if the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold, send an RRC release message to the second network device, and the RRC release message is used to instruct the terminal device to terminate the SDT process and maintain the RRC inactive state.

[0166] In an optional embodiment, the RRC release message also includes information for instructing the terminal device to immediately initiate an RRC recovery process, where the RRC recovery process is used by the terminal device to request to enter an RRC connected state and transmit data in the RRC connected state.

[0167] In an optional implementation, the communication unit 902 is further configured to receive second indication information from a second network device, where the second indication information is configured to indicate that the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to a data amount threshold.

[0168] Optionally, the second indication information is carried in a control plane message or a user plane message from the second network device.

[0169] In an optional implementation, the communication unit 902 is further configured to send a data volume threshold to the second network device.

[0170] Optionally, the data volume threshold is carried in a first response message sent to the second network device, and the first response message is used to indicate a partial context of the terminal device.

[0171] In an optional embodiment, the communication unit 902 is further configured to send a first response message to the second network device, the first response message including address information corresponding to third indication information, the third indication information being used to indicate the amount of data to be transmitted in the SDT of the terminal device. The communication unit 902 is further configured to receive the third indication information from the second network device based on the address information. The processing unit 901 is configured to determine, based on the third indication information, that the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to a data amount threshold.

[0172] Optionally, the first response message is used to indicate a partial context of the terminal device.

[0173] In another possible design, for a case where the communication apparatus 900 is used to implement the function of the second network device in the above method embodiment:

[0174] Communication unit 902 is used to send a first request message to the first network device, the first request message is used to request the context of the terminal device, the first request message includes first indication information, the first indication information is used to indicate that the terminal device has initiated an SDT process in an RRC inactive state, and the first network device has saved the context of the terminal device.

[0175] The communication unit 902 is further used to send second indication information to the first network device, where the second indication information is used to indicate that the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to a data amount threshold.

[0176] The communication unit 902 is further used to receive an RRC release message from the first network device, where the RRC release message is used to instruct the terminal device to terminate the SDT process and maintain an RRC inactive state.

[0177] The communication unit 902 is also used to send an RRC release message to the terminal device.

[0178] In an optional embodiment, the RRC release message also includes information for instructing the terminal device to immediately initiate an RRC recovery process, where the RRC recovery process is used by the terminal device to request to enter an RRC connected state and transmit data in the RRC connected state.

[0179] In an optional embodiment, the processing unit 901 is configured to determine a data volume threshold; or the communication unit 902 is further configured to receive the data volume threshold from the first network device. The communication unit 902 is further configured to: if the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data volume threshold, send second indication information to the first network device.

[0180] In an optional implementation, the communication unit 902 is further configured to receive third indication information from the terminal device, where the third indication information is configured to indicate the amount of SDT data to be transmitted of the terminal device.

[0181] In an optional implementation, the data volume threshold value received by the communication unit 902 is carried in a first response message from the first network device, and the first response message is used to indicate a partial context of the terminal device.

[0182] In an optional implementation manner, the second indication information is carried in a control plane message or a user plane message sent to the first network device.

[0183] In another possible design, for a case where the communication apparatus 900 is used to implement the function of the second network device in the above method embodiment:

[0184] Communication unit 902 is used to send a first request message to the first network device, the first request message is used to request the context of the terminal device, the first request message includes first indication information, the first indication information is used to indicate that the terminal device has initiated an SDT process in an RRC inactive state, and the first network device has saved the context of the terminal device.

[0185] The communication unit 902 is also used to receive a first response message from the first network device, the first response message includes address information, the address information corresponds to the third indication information, and the third indication information is used to indicate the amount of data to be transmitted of the SDT of the terminal device.

[0186] The communication unit 902 is further configured to send third indication information to the first network device according to the address information.

[0187] The communication unit is also used to receive an RRC release message from the first network device, where the RRC release message is used to instruct the terminal device to terminate the SDT process and maintain an RRC inactive state.

[0188] The communication unit 902 is also used to send an RRC release message to the terminal device.

[0189] In an optional embodiment, the RRC release message also includes information for instructing the terminal device to immediately initiate an RRC recovery process, where the RRC recovery process is used by the terminal device to request to enter an RRC connected state and transmit data in the RRC connected state.

[0190] In an optional implementation, the first response message is used to indicate a partial context of the terminal device.

[0191] The embodiments of the present application and the method embodiments shown above are based on the same concept, and the technical effects they bring are also the same. For the specific principles, please refer to the description of the embodiments shown above, and no further details will be given.

[0192] The present application also provides a communication device 1000, as shown in Figure 10. The communication device 1000 can be a first network device or a second network device, or can be a chip, chip system, or processor that supports the first network device to implement the above method, or can be a chip, chip system, or processor that supports the second network device to implement the above method. The device can be used to implement the method described in the above method embodiment. For details, please refer to the description of the above method embodiment.

[0193] The communication device 1000 may include one or more processors 1001. The processor 1001 may be used to implement some or all of the functions of the first network device or the second network device through logic circuits or running computer programs. The processor 1001 may be a general-purpose processor or a dedicated processor, etc. For example, it may be a baseband processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component or a central processing unit (CPU). The baseband processor may be used to process communication protocols and communication data, and the central processing unit may be used to control the communication device, execute software programs, and process data of the software programs, wherein the communication device is, for example, a base station, a baseband chip, a terminal, a terminal chip, a distributed unit (DU) or a distributed unit (CU), etc.

[0194] Optionally, the communication device 1000 may include one or more memories 1002, on which instructions 1004 may be stored. The instructions may be executed on the processor 1001, causing the communication device 1000 to perform the method described in the above method embodiment. Optionally, the memory 1002 may also store data. The processor 1001 and the memory 1002 may be provided separately or integrated together.

[0195] The memory 1002 may include, but is not limited to, non-volatile memory such as a hard disk drive (HDD) or a solid-state drive (SSD), random access memory (RAM), erasable programmable ROM (EPROM), ROM or compact disc read-only memory (CD-ROM), etc.

[0196] Optionally, the communication device 1000 may further include a transceiver 1005 and an antenna 1006. The transceiver 1005 may be referred to as a transceiver unit, a transceiver, or a transceiver circuit, etc., and is configured to implement transceiver functions. The transceiver 1005 may include a receiver and a transmitter. The receiver may be referred to as a receiver or a receiving circuit, etc., and is configured to implement a receiving function; the transmitter may be referred to as a transmitter or a transmitting circuit, etc., and is configured to implement a transmitting function.

[0197] In one possible design, for a case where the communication apparatus 1000 is used to implement the function of the first network device in the above method embodiment:

[0198] Transceiver 1005 is used to receive a first request message from a second network device, where the first request message is used to request the context of the terminal device. The first request message includes first indication information, where the first indication information is used to indicate that the terminal device has initiated an SDT process in an RRC inactive state, and the communication device 1000 has saved the context of the terminal device.

[0199] The transceiver 1005 is also used to: if the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold, send an RRC release message to the second network device, and the RRC release message is used to instruct the terminal device to terminate the SDT process and maintain the RRC inactive state.

[0200] In an optional embodiment, the RRC release message also includes information for instructing the terminal device to immediately initiate an RRC recovery process, where the RRC recovery process is used by the terminal device to request to enter an RRC connected state and transmit data in the RRC connected state.

[0201] In an optional implementation, the transceiver 1005 is further configured to receive second indication information from a second network device, where the second indication information is configured to indicate that the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to a data amount threshold.

[0202] Optionally, the second indication information is carried in a control plane message or a user plane message from the second network device.

[0203] In an optional implementation, the transceiver 1005 is further configured to send a data volume threshold to the second network device.

[0204] Optionally, the data volume threshold is carried in a first response message sent to the second network device, and the first response message is used to indicate a partial context of the terminal device.

[0205] In an optional embodiment, transceiver 1005 is further configured to send a first response message to the second network device, the first response message including address information, the address information corresponding to third indication information, the third indication information being used to indicate the amount of data to be transmitted in the SDT of the terminal device. Transceiver 1005 is further configured to receive the third indication information from the second network device based on the address information. Processor 1001 is configured to determine, based on the third indication information, that the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to a data amount threshold.

[0206] Optionally, the first response message is used to indicate a partial context of the terminal device.

[0207] In another possible design, for the case where the communication apparatus 1000 is used to implement the function of the second network device in the above method embodiment:

[0208] Transceiver 1005 is used to send a first request message to the first network device, the first request message is used to request the context of the terminal device, the first request message includes first indication information, the first indication information is used to indicate that the terminal device has initiated an SDT process in an RRC inactive state, and the first network device has saved the context of the terminal device.

[0209] The transceiver 1005 is further configured to send second indication information to the first network device, where the second indication information is configured to indicate that the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to a data amount threshold.

[0210] The transceiver 1005 is also used to receive an RRC release message from the first network device, where the RRC release message is used to instruct the terminal device to terminate the SDT process and maintain an RRC inactive state.

[0211] Transceiver 1005 is also used to send an RRC release message to the terminal device.

[0212] In an optional embodiment, the RRC release message also includes information for instructing the terminal device to immediately initiate an RRC recovery process, where the RRC recovery process is used by the terminal device to request to enter an RRC connected state and transmit data in the RRC connected state.

[0213] In an optional embodiment, processor 1001 is configured to determine a data volume threshold; or transceiver 1005 is further configured to receive the data volume threshold from the first network device. Transceiver 1005 is further configured to: if the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data volume threshold, send second indication information to the first network device.

[0214] In an optional implementation, the transceiver 1005 is further configured to receive third indication information from the terminal device, where the third indication information is configured to indicate the amount of SDT data to be transmitted of the terminal device.

[0215] In an optional implementation, the data volume threshold value received by the transceiver 1005 is carried in a first response message from the first network device, and the first response message is used to indicate a partial context of the terminal device.

[0216] In an optional implementation manner, the second indication information is carried in a control plane message or a user plane message sent to the first network device.

[0217] In another possible design, for the case where the communication apparatus 1000 is used to implement the function of the second network device in the above method embodiment:

[0218] Transceiver 1005 is used to send a first request message to the first network device, the first request message is used to request the context of the terminal device, the first request message includes first indication information, the first indication information is used to indicate that the terminal device has initiated an SDT process in an RRC inactive state, and the first network device has saved the context of the terminal device.

[0219] The transceiver 1005 is also used to receive a first response message from the first network device, the first response message includes address information, the address information corresponds to the third indication information, and the third indication information is used to indicate the amount of data to be transmitted of the SDT of the terminal device.

[0220] The transceiver 1005 is further configured to send third indication information to the first network device according to the address information.

[0221] The communication unit is also used to receive an RRC release message from the first network device, where the RRC release message is used to instruct the terminal device to terminate the SDT process and maintain an RRC inactive state.

[0222] Transceiver 1005 is also used to send an RRC release message to the terminal device.

[0223] In an optional embodiment, the RRC release message also includes information for instructing the terminal device to immediately initiate an RRC recovery process, where the RRC recovery process is used by the terminal device to request to enter an RRC connected state and transmit data in the RRC connected state.

[0224] In an optional implementation, the first response message is used to indicate a partial context of the terminal device.

[0225] In another possible design, processor 1001 may include a transceiver for implementing receiving and transmitting functions. For example, the transceiver may be a transceiver circuit, an interface, or an interface circuit. The transceiver circuit, interface, or interface circuit for implementing the receiving and transmitting functions may be separate or integrated. The transceiver circuit, interface, or interface circuit may be used for reading and writing code / data, or the transceiver circuit, interface, or interface circuit may be used for transmitting or delivering signals.

[0226] In another possible design, processor 1001 may optionally store instructions 1003. Instructions 1003, when executed on processor 1001, may cause communication device 1000 to perform the method described in the above method embodiment. Instructions 1003 may be fixed in processor 1001. In this case, processor 1001 may be implemented by hardware.

[0227] In another possible design, the communication device 1000 may include a circuit that can implement the functions of sending, receiving, or communicating in the aforementioned method embodiments. The processor and transceiver described in the embodiments of the present application can be implemented in an integrated circuit (IC), an analog IC, a radio frequency integrated circuit (RFIC), a mixed signal IC, an application specific integrated circuit (ASIC), a printed circuit board (PCB), an electronic device, etc. The processor and transceiver can also be manufactured using various IC process technologies, such as complementary metal oxide semiconductor (CMOS), N-type metal oxide semiconductor (nMetal-oxide-semiconductor, NMOS), P-type metal oxide semiconductor (positive channel metal oxide semiconductor, PMOS), bipolar junction transistor (bipolar junction transistor, BJT), bipolar CMOS (BiCMOS), silicon germanium (SiGe), gallium arsenide (GaAs), etc.

[0228] Those skilled in the art will also appreciate that the various illustrative logical blocks and steps listed in the embodiments of the present application can be implemented by electronic hardware, computer software, or a combination of both. Whether such functions are implemented by hardware or software depends on the specific application and the design requirements of the entire system. Those skilled in the art may use various methods to implement the described functions for each specific application, but such implementation should not be construed as exceeding the scope of protection of the embodiments of the present application.

[0229] The embodiments of the present application and the above-mentioned method embodiments are based on the same concept, and the technical effects they bring are also the same. For the specific principles, please refer to the description in the above-mentioned method embodiments, and no further details will be given.

[0230] The present application also provides a computer-readable storage medium for storing computer software instructions, which, when executed by a communication device, implements the functions of any of the above method embodiments.

[0231] The present application also provides a computer program product for storing computer software instructions, which, when executed by a communication device, implements the functions of any of the above method embodiments.

[0232] The present application also provides a computer program that, when executed on a computer, implements the functions of any of the above method embodiments.

[0233] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a high-density digital video disc (DVD)), or a semiconductor medium (eg, an SSD).

[0234] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A message transmission method, characterized in that: Applied to a first network device, the method comprises: Receiving a first request message from a second network device, where the first request message is used to request a context of a terminal device, where the first request message includes first indication information, where the first indication information is used to indicate that the terminal device has initiated a small data transmission SDT process in an inactive radio access control RRC state, and that the first network device has saved the context of the terminal device; If the amount of data to be transmitted in the SDT of the terminal device is greater than or equal to the data amount threshold, an RRC release message is sent to the second network device, and the RRC release message is used to instruct the terminal device to terminate the SDT process and maintain the RRC inactive state.

2. The method according to claim 1, characterized in that: The RRC release message also includes information for instructing the terminal device to immediately initiate an RRC recovery process, where the RRC recovery process is used by the terminal device to request to enter an RRC connection state and transmit data in the RRC connection state.

3. The method according to claim 1 or 2, characterized in that: The method further comprises: Receive second indication information from the second network device, where the second indication information is used to indicate that the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to the data amount threshold.

4. The method according to claim 3, characterized in that The second indication information is carried in a control plane message or a user plane message from the second network device.

5. The method according to claim 3 or 4, characterized in that: Before receiving the second indication information from the second network device, the method further includes: Send the data volume threshold to the second network device.

6. The method according to claim 5, characterized in that The data volume threshold value is carried in a first response message sent to the second network device, and the first response message is used to indicate a partial context of the terminal device.

7. The method according to claim 1 or 2, characterized in that: The method further comprises: Sending a first response message to the second network device, where the first response message includes address information, where the address information corresponds to third indication information, and where the third indication information is used to indicate the amount of data to be transmitted of the SDT of the terminal device; receiving the third indication information from the second network device according to the address information; According to the third indication information, it is determined that the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to the data amount threshold.

8. The method according to claim 7, characterized in that The first response message is used to indicate a partial context of the terminal device.

9. A message transmission method, characterized in that: Applied in the second network device, the method includes: Sending a first request message to a first network device, where the first request message is used to request a context of a terminal device, where the first request message includes first indication information, where the first indication information is used to indicate that the terminal device has initiated a small data transmission SDT process in an inactive radio access control RRC state, and that the first network device has saved the context of the terminal device; Sending second indication information to the first network device, where the second indication information is used to indicate that the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to a data amount threshold value; Receiving an RRC release message from the first network device, where the RRC release message is used to instruct the terminal device to terminate the SDT process and maintain an RRC inactive state; Send the RRC release message to the terminal device.

10. The method according to claim 9, characterized in that The RRC release message also includes information for instructing the terminal device to immediately initiate an RRC recovery process, where the RRC recovery process is used by the terminal device to request to enter an RRC connection state and transmit data in the RRC connection state.

11. The method according to claim 9 or 10, characterized in that: The sending second indication information to the first network device includes: Determine the data volume threshold value; or, receive the data volume threshold value from the first network device; If the amount of data to be transmitted of the SDT of the terminal device is greater than or equal to the data amount threshold, the second indication information is sent to the first network device.

12. The method according to claim 11, characterized in that The method further comprises: Receive third indication information from the terminal device, where the third indication information is used to indicate the amount of SDT data to be transmitted of the terminal device.

13. The method according to claim 11 or 12, characterized in that: The received data volume threshold value is carried in a first response message from the first network device, and the first response message is used to indicate a partial context of the terminal device.

14. The method according to any one of claims 9 to 13, characterized in that: The second indication information is carried in a control plane message or a user plane message sent to the first network device.

15. A message transmission method, characterized in that: Applied to the second network device, the method comprises: Sending a first request message to a first network device, where the first request message is used to request a context of a terminal device, where the first request message includes first indication information, where the first indication information is used to indicate that the terminal device has initiated a small data transmission SDT process in an inactive radio resource control RRC state, and that the first network device has saved the context of the terminal device; receiving a first response message from the first network device, the first response message including address information, the address information corresponding to third indication information, the third indication information being used to indicate the amount of data to be transmitted of the SDT of the terminal device; Sending the third indication information to the first network device according to the address information; Receiving an RRC release message from the first network device, where the RRC release message is used to instruct the terminal device to terminate the SDT process and maintain an RRC inactive state; Send the RRC release message to the terminal device.

16. The method according to claim 15, characterized in that The RRC release message also includes information for instructing the terminal device to immediately initiate an RRC recovery process, where the RRC recovery process is used by the terminal device to request to enter an RRC connection state and transmit data in the RRC connection state.

17. The method according to claim 15 or 16, characterized in that The first response message is used to indicate a partial context of the terminal device.

18. A communication device, characterized in that: The device includes a module or unit for implementing the method described in any one of claims 1 to 8, or the device includes a module or unit for implementing the method described in any one of claims 9 to 14, or the device includes a module or unit for implementing the method described in any one of claims 15 to 17.

19. A communication device, characterized in that: Including processors; The processor is used to execute a computer program or instruction in the memory so that the communication device performs the method described in any one of claims 1 to 8, or so that the communication device performs the method described in any one of claims 9 to 14, or so that the communication device performs the method described in any one of claims 15 to 17.

20. A communication system, characterized in that: The method comprises at least one of the following devices: a device for executing the method according to any one of claims 1 to 8, a device for executing the method according to any one of claims 9 to 14, and a device for executing the method according to any one of claims 15 to 17.

21. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed, it implements the method according to any one of claims 1 to 8, or implements the method according to any one of claims 9 to 14, or implements the method according to any one of claims 15 to 17.

22. A computer program product, characterized in that The computer program product comprises: a computer program code, which, when executed, implements the method according to any one of claims 1 to 8, or implements the method according to any one of claims 9 to 14, or implements the method according to any one of claims 15 to 17.

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