Data transmission method and device

Abstract

The present application provides a method and device for data transmission, wherein the method includes: receiving downlink data, wherein the downlink data is used to be sent to a terminal device; receiving first information from a second network device, wherein the first information is used to determine a time for sending the downlink data to the second network device; and sending the downlink data to the second network device according to the first information, thereby avoiding directly sending the downlink data to the second network device after receiving the downlink data, thereby alleviating the storage burden of the second network device.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the priority of the PCT international patent application filed with the China Patent Office on April 14, 2020, with application number PCT / CN2020 / 084774 and application name “A method and device for data transmission”, the entire contents of which are incorporated by reference in this application. Technical Field

[0003] The present application relates to the field of communication technology, and in particular to a method and device for data transmission. Background Art

[0004] When the terminal device is in a radio resource control (RRC) inactive state and the core network device receives downlink data from the terminal device, the core network device will send the downlink data to the anchor network device of the terminal device, and then the anchor network device will initiate paging to the terminal device to restore the RRC connection of the terminal device. When the RRC connection recovery is completed, the terminal device changes from the RRC inactive state to the RRC connected state. At this time, the network device can send the downlink data sent by the core network device to the terminal device.

[0005] In order to save energy, when the terminal device is in an RRC inactive state, the network device and the terminal device will agree on a possible time to page the terminal device, so that the terminal device wakes up periodically to listen to the paging messages of the network device.

[0006] After the network device receives the downlink data of the terminal device from the core network device, it needs to store the downlink data before the agreed paging time. When the discontinuous cycle of the terminal device is long, it will cause a large storage burden on the network device. Summary of the invention

[0007] The present application provides a data transmission method and device for reducing the load of downlink data stored by a network device at a terminal device.

[0008] In a first aspect, an embodiment of the present application provides a method for data transmission, which can be implemented by a first network device, or by a component of the first network device, such as a processing device, a circuit, a chip, or other component in the first network device. The method includes:

[0009] Receive downlink data, the downlink data is used to send to the terminal device; receive first information from a second network device, the first information is used to determine the time to send the downlink data to the second network device; send the downlink data to the second network device according to the first information.

[0010] Exemplarily, the first network device may be a user plane function (UPF) network element, and the second network device may be an access network device.

[0011] Through the above method, after receiving the downlink data, the first network device determines the time to send the downlink data to the second network device according to the first information, avoiding directly sending the downlink data to the second network device after receiving the downlink data, thereby alleviating the storage burden of the second network device.

[0012] In one possible design, the first information includes an extended discontinuous reception (eDRX) cycle; or, the first information includes an eDRX cycle and a paging time window (PTW) duration; or, the first information includes an eDRX cycle and a first duration; or, the first information includes an eDRX cycle, a PTW duration and a first duration; or, the first information includes the first duration; or, the first information includes eighth indication information; or, the first information includes the eighth indication information and a second duration; or, the first information includes ninth indication information; wherein the first duration is used to indicate a time interval to a next PTW, or to indicate a time interval to a next paging occasion (PO), the eighth indication information is used to indicate a suspension of sending downlink data to a terminal device, the second duration is used to indicate a duration of suspension of sending the downlink data to the terminal device, and the ninth indication information is used to indicate a resumption of sending the downlink data to the terminal device.

[0013] Through the above method, the first information can be used to determine the sending time of downlink data. Exemplarily, when the first information is an eDRX cycle, the downlink data can be sent a little before the eDRX cycle. After receiving the downlink data, the second network device does not need to wait for a long time to page the terminal device, thereby reducing the time for the second network device to cache downlink data. When the first information contains other information, the first network device can determine a more accurate sending time based on the first information, further reducing the storage burden of the second network device. In addition, the eighth indication information can directly indicate the suspension of sending downlink data to the access network device, or the ninth indication information can directly indicate the resumption of sending downlink data to the access network device, which can save the computing resources of the first network device, such as the core network device, and the interaction process is simple and more flexible.

[0014] In one possible design, sending the downlink data to the second network device according to the first information includes: determining a latest sending time for sending the downlink data according to the first information; and sending the downlink data to the second network device within a first preset time period before the latest sending time.

[0015] In an optional implementation, the first preset duration may be predefined, for example, defined by a protocol or standard, or preconfigured, or may be in other ways, such as notified by the second network device, which is not limited in this embodiment of the present application.

[0016] In another optional implementation, the latest sending time is the wake-up time of the terminal device after receiving the downlink data.

[0017] Exemplarily, the first information also includes PTW; if the time when the first network device receives the downlink data is within the PTW, the latest sending time is the end time domain position of the end time of the PTW; if the time when the UPF receives the downlink data is outside the PTW, the latest sending time is the first time domain position, and the first time domain position is the starting time domain position of the next eDRX cycle, or the end time domain position of the PTW within the next eDRX cycle, or the starting time domain position of any paging opportunity within the PTW within the next eDRX cycle.

[0018] Another exemplary embodiment is that the first message includes a first duration; and further includes: the first network device determines the starting time domain position of the next PTW based on the time of receiving the first message and the first duration, or determines the starting time domain position of the next PO; the latest sending time is the starting time domain position of the next eDRX cycle of the eDRX cycle in which the first network device receives the downlink data; or the latest sending time is the starting time domain position of the next PO when the first network device receives the downlink data.

[0019] Through the above method, the first network device can determine the eDRX cycle of the terminal device based on the first information, the eDRX cycle includes the wake-up time of the terminal device, and the latest sending time of the downlink data determined by the first network device can be the wake-up time of the terminal device most recently after the first network device receives the downlink data. The first network device can send the downlink data to the access network device of the terminal device before the most recent wake-up time of the terminal device, thereby reducing the storage burden of the access network device and reducing the delay of the terminal device in receiving the downlink data.

[0020] In one possible design, the method includes: sending second indication information to the second network device or the third network device; wherein the second indication information is used to indicate the presence of the downlink data.

[0021] In an optional implementation, the third network device may be an access and mobility management function (AMF) network element.

[0022] Through the above method, the first network device can notify the second network device or the third network device through the second indication information when the downlink data is not cached, so that the second network device or the third network device selectively releases the terminal device to save the power consumption of the terminal device. For example, when the second network device does not need to send downlink data to the terminal device, it can switch the terminal device to a radio resource control (RRC) inactive state, or maintain the RRC inactive state.

[0023] In one possible design, the first network device is a user plane network element UPF, the second network device is an access network device, and the third network device is an access network device or an access and mobility management network element AMF.

[0024] In a second aspect, an embodiment of the present application provides a method for data transmission, which can be implemented by a second network device, or by a component of the second network device, such as a processing device, a circuit, a chip, etc. in the second network device. The method includes: determining first information, the first information is used to determine a sending time of downlink data, and the downlink data is used to send to a terminal device; sending the first information to the first network device.

[0025] In one possible design, the first information includes: the first information includes an extended discontinuous reception eDRX cycle; or, the first information includes the eDRX cycle and the paging time window PTW duration; or, the first information includes the eDRX cycle and the first duration; or, the first information includes the eDRX cycle, the PTW duration and the first duration; or, the first information includes the first duration; or, the first information includes eighth indication information; or, the first information includes the eighth indication information and the second duration; or, the first information includes ninth indication information; wherein, the first duration is used to indicate the time interval to the next PTW, or to indicate the time interval to the next paging occasion (paging occasion, PO), the eighth indication information is used to indicate the suspension of sending downlink data to the terminal device, the second duration is used to indicate the duration of suspending the sending of the downlink data to the terminal device, and the ninth indication information is used to indicate the resumption of sending the downlink data to the terminal device.

[0026] In one possible design, the method includes: receiving second indication information; wherein the second indication information is used to indicate the presence of the downlink data.

[0027] In a possible design, before sending the first information to the first network device, it also includes: determining that an extended discontinuous reception eDRX cycle is not less than a preset threshold.

[0028] Through the above method, when the UE is in the eDRX cycle mode, the second network device (e.g., the access network device) can send the first information to the third network device (e.g., AMF). Furthermore, it can also decide whether to send the first information based on the length of the eDRX cycle. For example, when the length of the eDRX cycle is not less than a preset threshold, the access network device sends the first information to avoid the access network device needing to cache the UE's downlink data for a long time when the UE is in a longer eDRX cycle, thereby reducing the storage load of the access network device.

[0029] In one possible design, the first network device is a user plane network element UPF or an access and mobility management network element AMF.

[0030] The technical effects that can be achieved by any possible design of the second aspect mentioned above can refer to the technical effects that can be achieved by the first aspect mentioned above, and will not be repeated here.

[0031] In a third aspect, an embodiment of the present application provides a method for data transmission, which can be implemented by a third network device, or by a component of the third network device, such as a processing device, a circuit, a chip, or other component in the third network device. The method includes:

[0032] Receive first information from a second network device; the first information is used to determine a time to send downlink data, and the downlink data is used to send to a terminal device; send the first information to the first network device.

[0033] In one possible design, the first information includes: the first information includes an extended discontinuous reception eDRX cycle; or, the first information includes the eDRX cycle and the paging time window PTW duration; or, the first information includes the eDRX cycle and the first duration; or, the first information includes the eDRX cycle, the PTW duration and the first duration; wherein the first duration is used to indicate the time interval to the next PTW, or, to indicate the time interval to the next paging opportunity PO.

[0034] In one possible design, the method includes: receiving second indication information from the first network device; wherein the second indication information is used to indicate that the first network device has the downlink data.

[0035] In one possible design, the first network device is a user plane network element UPF, and the second network device is an access network device.

[0036] The technical effects that can be achieved by any possible design of the third aspect mentioned above can refer to the technical effects that can be achieved by the first aspect mentioned above, and will not be repeated here.

[0037] In a fourth aspect, an embodiment of the present application provides a method for data transmission, which can be implemented by a first network device, or by a component of the first network device, such as a processing device, a circuit, a chip, or other components in the first network device. The method includes: receiving second information from a second network device, the second information being used to indicate that a terminal device is reachable; and sending downlink data of the terminal device to the second network device according to the second information.

[0038] Exemplarily, the terminal device being reachable means that the terminal device is online or indicates that downlink data is reachable or indicates that the terminal device is in RRC activated state. In short, the terminal device being reachable can be used by the first network device to determine that the downlink data of the terminal device can be sent to the access network device.

[0039] Optionally, after receiving the second information, the first network device determines whether the downlink data of the terminal device is cached, and if so, sends the downlink data of the terminal device to the access network device according to the second information.

[0040] The above method enhances the flexibility of the first network device in sending downlink data to the access network device and reduces the delay of the terminal device in receiving the downlink data.

[0041] In one possible design, the second information is used to indicate that the terminal device requests to enter a radio resource control (RRC) connection state, or the second information is used to indicate that the terminal device is in an RRC connection state.

[0042] In one possible design, the method further includes: determining that downlink data of the terminal device is cached.

[0043] In one possible design, the method includes: sending fourth indication information to the second network device or the third network device; wherein the fourth indication information is used to indicate whether downlink data of the terminal device is cached.

[0044] In one possible design, the second network device is an access network device, and the third network device is an access network device or an access and mobility management network element AMF.

[0045] In a fifth aspect, an embodiment of the present application provides a method for data transmission, which can be implemented by a second network device, or by components of the second network device, such as a processing device, circuit, chip, or other components in the second network device.

[0046] Determine second information, where the second information is used to indicate that the terminal device is reachable; and send the second information to the first network device.

[0047] In one possible design, the second information is used to indicate that the terminal device requests to enter a radio resource control (RRC) connection state, or the second information is used to indicate that the terminal device is in an RRC connection state.

[0048] In one possible design, the method includes: receiving fourth indication information from the first network device; wherein the fourth indication information is used to indicate whether downlink data of the terminal device is cached.

[0049] In a possible design, it also includes: sending sixth indication information to the third network device, the sixth indication information is used to indicate the load status of the second network device, or the sixth indication information is used to indicate that the second network device supports the ability to send first information to the first network device.

[0050] In one possible design, the first network device is a user plane network element UPF; the second network device is an access network device, and the third network device is an access and mobility management network element AMF.

[0051] The technical effects that can be achieved by any possible design of the fifth aspect mentioned above can refer to the technical effects that can be achieved by the fourth aspect mentioned above, and will not be repeated here.

[0052] In a sixth aspect, an embodiment of the present application provides a method for data transmission, which can be implemented by a third network device, or by a component of the third network device, such as a processing device, a circuit, a chip, etc. in the third network device. The method includes: determining second information, where the second information is used to indicate that the terminal device is reachable; and sending the second information to the first network device.

[0053] In one possible design, the second information is used to indicate that the terminal device requests to enter a radio resource control (RRC) connection state, or the second information is used to indicate that the terminal device is in an RRC connection state.

[0054] In one possible design, the method includes receiving second information from a second network device.

[0055] In one possible design, the method includes: receiving fourth indication information from the first network device, the fourth indication information being used to indicate whether downlink data of the terminal device is cached.

[0056] In a possible design, it also includes: receiving sixth indication information, where the sixth indication information is used to indicate the load status of the second network device, or the sixth indication information is used to indicate that the second network device supports the ability to send first information to the first network device.

[0057] In one possible design, the first network device is a user plane network element UPF, and the second network device is an access network device.

[0058] The technical effects that can be achieved by any possible design of the sixth aspect mentioned above can refer to the technical effects that can be achieved by the fourth aspect mentioned above, and will not be repeated here.

[0059] In the seventh aspect, the embodiment of the present application provides a method for data transmission, which can be implemented by a third network device, or by a component of the third network device, such as a processing device, a circuit, a chip, and other components in the third network device. The method includes: receiving a first message from a second network device; after sending the second message, waiting to receive a response message from a terminal device within the waiting time, wherein the second message is used to send to the terminal device; wherein the first message includes one or more of the following: an extended discontinuous reception eDRX cycle, a paging time window PTW duration, a first duration, and a first indication information; wherein the first duration is used to indicate a time interval from the next PTW, or to indicate a time interval from the next paging opportunity PO; the first indication information is used to indicate that the terminal device is in an RRC inactive state.

[0060] Exemplarily, waiting to receive the response information of the UE within the waiting time can be achieved through a timer. Specifically, the setting time of the timer is the determined waiting time, and the waiting to receive the response information of the UE is performed before the timer times out. If the response information of the UE is received before the timeout, the timer can be turned off.

[0061] Through the above method, the waiting time is determined according to the first information, and after sending the second information to the access network device, the response information of the terminal device is received during the determined waiting time. Compared with the existing time, the waiting time can be more adapted to the response time required by the UE, and is dynamically configurable. For example, the access network device can dynamically configure the first information according to the eDRX cycle of the UE to avoid misoperation of the UE.

[0062] In one possible design, the terminal device is in a connection management connection state (CM connected); the second information is non-access stratum (NAS) signaling.

[0063] In an eighth aspect, an embodiment of the present application provides a method for data transmission, which can be implemented by a second network device, or by a component of the second network device, such as a processing device, a circuit, a chip, or other components in a third network device. The method includes: determining first information; sending the first information to the first network device; wherein the first information includes one or more of the following: an extended discontinuous reception eDRX cycle, a paging time window PTW duration, a first duration, and a first indication information; wherein the first duration is used to indicate a time interval from the next PTW, or to indicate a time interval from the next paging opportunity PO; the first indication information is used to indicate that the terminal device is in an RRC inactive state.

[0064] In one possible design, the first information is used to determine the response time of the terminal device to the second information, and the second information is used to send to the terminal device.

[0065] In a possible design, before sending the first information to the first network device, it also includes: determining that an extended discontinuous reception eDRX cycle is not less than a preset threshold.

[0066] Through the above method, when the UE is in the eDRX cycle mode, the second network device (such as the access network device) can send the first information to the third network device (such as the AMF). Further, it can also decide whether to send the first information according to the length of the eDRX cycle. For example, when the length of the eDRX cycle is not less than the preset threshold, the second network device sends the first information, so that the third network side device can adjust the waiting time in time, better adapt to the mode change of the UE, and reduce the erroneous operation of the UE. If the length of the eDRX cycle is less than the preset threshold, the second network device may not send the first information, which can be understood as the original waiting time of the third network device can cover the response time required after the UE mode changes, so as to reduce the signaling interaction and save signaling and computing resources on the basis of determining that the erroneous operation of the UE can be reduced.

[0067] The technical effects that can be achieved by any possible design of the eighth aspect mentioned above can refer to the technical effects that can be achieved by the seventh aspect mentioned above, and will not be repeated here.

[0068] In a ninth aspect, the present application provides a data transmission device, which may be a user plane network element, or a chip for a user plane network element. The device has the functions of implementing the embodiments of the first aspect above, or the functions of the embodiments of the fourth aspect above. The function may be implemented by hardware, or may be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0069] Exemplarily, the device includes a communication module and a processing module, wherein the communication module includes a sending module and a receiving module.

[0070] In one possible design, a receiving module is used to receive downlink data, and the downlink data is used to send to a terminal device; receive first information from a second network device, and the first information is used to determine the time to send the downlink data to the second network device; and a processing module is used to send the downlink data to the second network device according to the first information.

[0071] In one possible design, a receiving module is used to receive second information from a second network device, where the second information is used to indicate that the terminal device is reachable; and a processing module is used to send downlink data of the terminal device to the second network device according to the second information.

[0072] In a tenth aspect, the present application provides a data transmission device, which may be an access network device or a chip for an access network device. The device has the functions of implementing the embodiments of the second aspect, the functions of the embodiments of the fifth aspect, or the functions of the embodiments of the eighth aspect. The functions may be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0073] Exemplarily, the device includes a communication module and a processing module, wherein the communication module includes a sending module and a receiving module.

[0074] In one possible design, a processing module is used to determine first information, where the first information is used to determine a sending time of downlink data, and the downlink data is used to send to a terminal device; and a sending module is used to send the first information to a first network device.

[0075] In one possible design, a processing module is used to determine second information, where the second information is used to indicate that a terminal device is reachable; and a sending module is used to send the second information to a first network device.

[0076] In one possible design, a processing module is used to determine first information; wherein the first information includes one or more of the following: an extended discontinuous reception eDRX cycle, a paging time window PTW duration, a first duration, and first indication information; wherein the first duration is used to indicate the time interval to the next PTW, or to indicate the time interval to the next paging opportunity PO; the first indication information is used to indicate that the terminal device is in an RRC inactive state; a sending module is used to send the first information to a third network device.

[0077] In an eleventh aspect, the present application provides a data transmission device, which may be a mobility management network element, or a chip for a mobility management network element. The device has the functions of implementing the embodiments of the third aspect, or the functions of the embodiments of the sixth aspect, or the functions of the embodiments of the seventh aspect. The function may be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0078] The device comprises a communication module and a processing module, wherein the communication module comprises a sending module and a receiving module.

[0079] In one possible design, a receiving module is used to receive first information from a second network device; the first information is used to determine a sending time of downlink data, and the downlink data is used to send to a terminal device; and a sending module is used to send the first information to the first network device.

[0080] In one possible design, a processing module is used to determine second information, where the second information is used to indicate that a terminal device is reachable; and a sending module is used to send the second information to a first network device.

[0081] In one possible design, a receiving module is used to receive first information from a second network device; wherein the first information includes one or more of the following: an extended discontinuous reception eDRX cycle, a paging time window PTW duration, a first duration, and a first indication information; wherein the first duration is used to indicate a time interval to the next PTW, or to indicate a time interval to the next paging opportunity PO; the first indication information is used to indicate that the terminal device is in an RRC inactive state; a processing module is used to wait for receiving a response information from the terminal device through the receiving module within the waiting time after sending the second information through the sending module, wherein the second information is used to be sent to the terminal device.

[0082] In a twelfth aspect, the present application provides a data transmission device, comprising a processor and an interface circuit, wherein the processor is used to communicate with other devices through the interface circuit and execute the methods described in the above aspects. The processor comprises one or more.

[0083] In the first embodiment, when the device is the device of the seventh aspect above, exemplarily, the interface circuit is used to receive downlink data, and the downlink data is used to send to the terminal device; receive first information from the second network device, and the first information is used to determine the time to send the downlink data to the second network device; the processor is used to send the downlink data to the second network device according to the first information.

[0084] As another example, the interface circuit is used to receive second information from a second network device, where the second information is used to indicate that the terminal device is reachable; and the processor is used to send downlink data of the terminal device to the second network device according to the second information.

[0085] In a second embodiment, when the device is the device of the eighth aspect above, exemplarily, the processor is used to determine first information, wherein the first information is used to determine the sending time of downlink data, and the downlink data is used to send to a terminal device; and the interface circuit is used to send the first information to a first network device.

[0086] As another example, the processor is used to determine second information, where the second information is used to indicate that the terminal device is reachable; and the interface circuit is used to send the second information to the first network device.

[0087] In a third embodiment, when the device is the device of the ninth aspect above, exemplarily, the interface circuit is used to receive first information from a second network device; the first information is used to determine the sending time of downlink data, and the downlink data is used to send to a terminal device; and the first information is sent to the first network device.

[0088] As another example, the processor is used to determine second information, where the second information is used to indicate that the terminal device is reachable; and the interface circuit is used to send the second information to the first network device.

[0089] In an eleventh aspect, the present application provides a data transmission device, including a processor, which is connected to a memory and is used to call a program stored in the memory to execute the methods described in the above aspects. The memory can be located inside the device or outside the device. And the processor includes one or more.

[0090] In a twelfth aspect, the present application further provides a computer-readable storage medium, wherein instructions are stored in the computer-readable storage medium, and when the computer-readable storage medium is run on a computer, the processor executes the methods described in the above aspects.

[0091] In a thirteenth aspect, the present application also provides a computer program product comprising instructions, which, when executed on a computer, enables the computer to execute the methods described in the above aspects.

[0092] In a fourteenth aspect, the present application also provides a chip or a chip system, including: a processor and a communication interface, wherein the processor is used to communicate with other devices through the communication interface and execute the methods described in the above aspects.

[0093] In a fifteenth aspect, the present application also provides a system for data transmission, comprising: a first network device for executing any method described in the first aspect, a second network device for executing any method described in the second aspect, and a third network device for executing any method described in the third aspect.

[0094] In the sixteenth aspect, the present application also provides a system for data transmission, including: a first network device for executing any method described in the fourth aspect, a second network device for executing any method described in the fifth aspect, and a third network device for executing any method described in the sixth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0095] Figure 1 A schematic diagram of the DRX principle provided in this application;

[0096] Figure 2 A system architecture diagram provided for an embodiment of the present application;

[0097] Figure 3 A schematic diagram of a data transmission method provided in an embodiment of the present application;

[0098] Figure 4 One of the schematic diagrams of a method for determining a downlink data sending time according to first information provided in an embodiment of the present application;

[0099] Figure 5 One of the schematic diagrams of a method for determining a downlink data sending time according to first information provided in an embodiment of the present application;

[0100] Figure 6 One of the schematic diagrams of a method for determining a downlink data sending time according to first information provided in an embodiment of the present application;

[0101] Figure 7 One of the schematic diagrams of a method for determining a downlink data sending time according to first information provided in an embodiment of the present application;

[0102] Figure 8 One of the schematic diagrams of a method for determining a downlink data sending time according to first information provided in an embodiment of the present application;

[0103] Fig. 9 One of the schematic diagrams of a method for determining a downlink data sending time according to first information provided in an embodiment of the present application;

[0104] Fig.10 One of the schematic diagrams of a method for determining a downlink data sending time according to first information provided in an embodiment of the present application;

[0105] Fig.11a One of the schematic diagrams of a method for determining a downlink data sending time according to first information provided in an embodiment of the present application;

[0106] Fig.11b One of the schematic diagrams of a method for determining a downlink data sending time according to first information provided in an embodiment of the present application;

[0107] Fig.12 One of the schematic diagrams of a method for determining a downlink data sending time according to first information provided in an embodiment of the present application;

[0108] Fig.13 One of the schematic diagrams of a method for determining a downlink data sending time according to first information provided in an embodiment of the present application;

[0109] Fig.14 A schematic diagram of a data transmission method provided in an embodiment of the present application;

[0110] Fig.15 A schematic diagram of a data transmission method provided in an embodiment of the present application;

[0111] Fig.16 A schematic diagram of another method flow for data transmission provided in an embodiment of the present application;

[0112] Fig.17 A schematic diagram of another method flow for data transmission provided in an embodiment of the present application;

[0113] Fig.18 A schematic diagram of a method for determining a downlink data sending time according to first information and second information provided in an embodiment of the present application;

[0114] Fig.19 A schematic diagram of another method flow for data transmission provided in an embodiment of the present application;

[0115] Fig. 20 A schematic diagram of another method flow for data transmission provided in an embodiment of the present application;

[0116] Fig.21 A schematic diagram of another method flow for data transmission provided in an embodiment of the present application;

[0117] Fig. 22 A schematic diagram of another method flow for data transmission provided in an embodiment of the present application;

[0118] Fig.23 A schematic diagram of another method flow for data transmission provided in an embodiment of the present application;

[0119] Fig.24 A schematic diagram of a protocol data unit session modification process;

[0120] Fig.25 A flowchart corresponding to a data transmission method provided in an embodiment of the present application;

[0121] Fig.26 One of the schematic diagrams of the method for determining the waiting time according to the first information provided in the embodiment of the present application;

[0122] Fig. 27 One of the schematic diagrams of the method for determining the waiting time according to the first information provided in the embodiment of the present application;

[0123] Fig.28 One of the schematic diagrams of the method for determining the waiting time according to the first information provided in the embodiment of the present application;

[0124] Fig.29 One of the schematic diagrams of the method for determining the waiting time according to the first information provided in the embodiment of the present application;

[0125] Fig.30 One of the schematic diagrams of the method for determining the waiting time according to the first information provided in the embodiment of the present application;

[0126] Fig.31 One of the schematic diagrams of the method for determining the waiting time according to the first information provided in the embodiment of the present application;

[0127] Fig.32 One of the schematic diagrams of the method for determining the waiting time according to the first information provided in the embodiment of the present application;

[0128] Fig.33 One of the schematic diagrams of the method for determining the waiting time according to the first information provided in the embodiment of the present application;

[0129] Fig.34 A schematic diagram of a complete method flow for data transmission provided in an embodiment of the present application;

[0130] Fig.35 A flowchart corresponding to another data transmission method provided in an embodiment of the present application;

[0131] Fig.36 One of the schematic diagrams of a method for determining a time to send second information according to first information provided in an embodiment of the present application;

[0132] Fig.37 One of the schematic diagrams of a method for determining a time to send second information according to first information provided in an embodiment of the present application;

[0133] Fig.38 One of the schematic diagrams of a method for determining a time to send second information according to first information provided in an embodiment of the present application;

[0134] Fig.39 One of the schematic diagrams of a method for determining a time to send second information according to first information provided in an embodiment of the present application;

[0135] Fig.40 One of the schematic diagrams of a method for determining a time to send second information according to first information provided in an embodiment of the present application;

[0136] Fig.41 One of the schematic diagrams of a method for determining a time to send second information according to first information provided in an embodiment of the present application;

[0137] Fig.42 One of the schematic diagrams of a method for determining a time to send second information according to first information provided in an embodiment of the present application;

[0138] Fig.43 One of the schematic diagrams of a method for determining a time to send second information according to first information provided in an embodiment of the present application;

[0139] Fig.44One of the schematic diagrams of a method for determining a time to send second information according to first information provided in an embodiment of the present application;

[0140] Fig.45 A schematic diagram of the structure of a device provided in this application;

[0141] Fig.46 A schematic diagram of the structure of another device provided in this application. DETAILED DESCRIPTION

[0142] In order to make the purpose, technical solution and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings. The specific operation method in the method embodiment can also be applied to the device embodiment or the system embodiment. In the description of the present application, unless otherwise specified, the meaning of "multiple" is two or more.

[0143] In a wireless communication system, such as a long term evolution (LTE) system or a fifth generation (5G) communication system, a terminal device can perform a radio resource control (RRC) connection establishment process with a network device. When the terminal device and the network device establish an RRC connection, the RRC state of the terminal device is the RRC connected state. Subsequently, the RRC state of the terminal device can be converted in the following states: RRC idle (RRC_IDLE) state, RRC connected (RRC_CONNECTED) state, and RRC inactive (RRC_INACTIVE) state.

[0144] First, the three RRC states of the terminal device are introduced:

[0145] 1. RRC idle state

[0146] When the terminal device is in the RRC idle state, the RRC connection between the terminal device and the access network is released. At this time, the terminal device can receive paging messages, broadcast channels, and / or system information from the network device.

[0147] In this RRC state, the network device does not know whether the terminal device is within the coverage of the network device or within the management scope of the network device. For example, the network device does not know whether the terminal device is within the coverage of the cell managed by the network device. The core network does not know which network device's coverage or management scope the terminal device is within, and the core network does not know through which network device the terminal device can be located or found.

[0148] 2. RRC inactive state

[0149] When the terminal device is in the RRC inactive state, there is no RRC connection between the terminal device and the network device. At this time, the network device does not know whether the terminal device is within the coverage of the network device or the management scope of the network device, for example, the network device does not know whether the terminal device is within the coverage of the cell managed by the network device; the core network knows which network device or devices the terminal device is within the coverage or management scope, and the core network knows which network device or devices can be used to locate or find the terminal device.

[0150] When the terminal device is in the RRC_INACTIVE state, the terminal device can receive paging messages, synchronization signals, broadcast messages, and / or system information from the network device.

[0151] 3. RRC connection state;

[0152] When the terminal device is in the RRC_CONNECTED state, there is an RRC connection between the terminal device and the network device. Therefore, the network device knows that the terminal device is within the coverage of the network device or within the management scope of the network device.

[0153] At present, when a network device and a terminal device perform data transmission specific to the terminal device, for example, the network device is an access network device, and the access network device receives downlink data of the terminal device from the core network device (for example, downlink data of a PDU session of the terminal device), when the access network device sends the downlink data to the terminal device, the terminal device needs to be in an RRC connected state. Exemplarily, if the terminal device is in an RRC idle state or an RRC inactive state, the terminal device first performs an RRC connection establishment process with the network device. After the terminal device and the network device establish an RRC connection, the terminal device is in an RRC connected state, and data transmission specific to the terminal device can be performed at this time.

[0154] Exemplarily, the terminal device can convert the terminal device from an RRC idle state or an RRC inactive state to an RRC connected state through an RRC connection establishment process with a network device. The RRC connection establishment process can be triggered by a network device. For example, when the terminal device is in an RRC inactive state, the network device sends a paging message to the terminal device, and the paging message includes an identifier of the terminal device. Correspondingly, after the terminal device receives the paging message from the network device, it triggers the RRC connection establishment process. The RRC connection establishment process can also be triggered by a high layer of the terminal device. For example, when the terminal device has a need to send uplink data, the high layer of the terminal device triggers the RRC connection establishment process.

[0155] The process of the network device sending a paging message to the terminal device may be:

[0156] Since the downlink data from the network device is unpredictable, when the RRC is not activated, the terminal device wakes up periodically to monitor the downlink data that the network device may send. For example, the network device configures discontinuous reception (DRX) for the terminal device. DRX means that the terminal device does not need to continuously monitor paging messages, but wakes up periodically according to DRX to monitor paging messages, so as to achieve the purpose of power saving. Figure 1 FIG. 1 is a schematic diagram of a DRX cycle. DRX includes on duration (wake-up period) and Opportunity for DRX (sleep period).

[0157] Specifically, for on duration, the terminal device is in an awake activation state. If the network device has downlink data to send to the terminal device, it will initiate paging to the terminal device within the on duration. Accordingly, the terminal device needs to monitor PDCCH within the on duration to detect whether the network device initiates paging to itself. Exemplarily, on duration includes at least one paging occasion (PO). The process of the network device initiating paging to the terminal device may include: the network device sends a DCI for scheduling a paging message at a paging occasion (PO) within the on duration, and sends a paging message at the resource location indicated by the DCI. Accordingly, the terminal device monitors PDCCH at the paging occasion within the on duration, blindly detects DCI, and receives the paging message according to the resource location indicated by the DCI, and performs an RRC connection establishment process with the network device.

[0158] During the Opportunity for DRX period, the terminal device is in a sleep state and does not monitor the PDCCH. Therefore, the network device does not initiate paging to the terminal device during this period.

[0159] For example, if the DRX cycle is 10s and the on duration is 1s, the terminal device will wake up every 10s and listen to the paging message that the access network device may send within 1s of the on duration until the paging message is received or the onduration is completed. In the above method, although the terminal device does not need to continuously monitor the channel, the terminal device still needs to wake up frequently to listen to the paging message.

[0160] In order to further reduce the energy consumption of the terminal device, the network device can also configure a longer sleep time for the terminal device in the RRC inactive state, for example, the network device configures extended discontinuous reception (eDRX) for the terminal device. In eDRX, the network device can configure a paging time window PTW for the terminal device. For example, (see Fig.11b )PTW can be understood as one or more DRX cycles that are executed cyclically, that is, the terminal device wakes up according to the DRX periodicity in the PTW to listen to the paging message, and continues to be in a sleep state outside the PTW of eDRX. In PTW, the on duration in the DRX cycle can be called the paging opportunity (PO). For example, the eDRX cycle can be 3h, the PTW can be 100s, and the paging opportunity period is 10s. The terminal device wakes up every 10s in the PTW and listens to the paging message in the paging opportunity. In eDRX, the time except the paging opportunity is the sleep state, that is, the terminal device only needs to wake up 10 times in an eDRX cycle. In summary, compared with DRX, the terminal device in eDRX is in a sleep state for a longer time, and does not need to wake up frequently to listen to the paging message, thereby further reducing the power consumption of the terminal device, but it increases the difficulty of the network device to page the terminal device, that is, the network device may need to store the downlink data of the terminal device for a long time, which increases the storage burden of the network device. How to reduce the storage load of the network device on the basis of reducing the energy consumption of the terminal device is an urgent problem to be solved.

[0161] In view of this, a technical solution of an embodiment of the present application is provided. In an embodiment of the present application, an access network device sends a first information to a core network device, and the first information is used to determine the time when the core network device sends the downlink data of the terminal device to the access network device. After the core network device receives the downlink data of the terminal device, for example, the data of the Youku service requested by the terminal device through the PDU session is received from the DN, the core network device sends the downlink data to the access network device according to the first information. For example, the core gateway device determines the time to send the downlink data according to the first information, and when the time arrives, the downlink data is sent to the access network device, thereby reducing the storage burden of the access network device.

[0162] The technical solution provided in the embodiments of the present application can be applied to various communication systems, for example, it can be applied to communication systems such as LTE and 5G, and can also be applied to wireless fidelity (WiFi), worldwide interoperability for microwave access (WiMAX), or future communication systems, such as the future sixth generation (6G) system. Among them, 5G can also be called new radio (NR). Exemplarily, in a communication system to which the technical solution provided in the embodiments of the present application can be applied, one entity can initiate paging or access to another entity. In the introduction process of the embodiments of the present application, the air interface communication process between a network device and a terminal device is taken as an example. Optionally, the technical solution provided in the embodiments of the present application can also be applied to sidelink (SL) communication, in which a terminal device can initiate paging or access to another terminal device. For example, the technical solution provided in the embodiments of the present application can be applied to device-to-device (D2D) communication scenarios, such as NR D2D communication scenarios and / or LTE D2D communication scenarios, etc.; or it can be applied to vehicle-to-everything (V2X) communication scenarios, such as NR V2X communication scenarios, LTE V2X communication scenarios, Internet of Vehicles communication scenarios, and / or vehicle-to-vehicle (V2V) communication scenarios, etc.; or it can be used in the fields of intelligent driving, intelligent connected vehicles, etc.

[0163] like Figure 2 The figure shows a network architecture applicable to the embodiment of the present application. The following briefly introduces some network elements included in the architecture and the functions of each network element.

[0164] 1) Terminal equipment, which can be a device with wireless transceiver function. The terminal equipment can be referred to as a terminal, which can be deployed on land, including indoors, outdoors, and / or handheld or vehicle-mounted; it can also be deployed on the water (such as ships, etc.); it can also be deployed in the air (for example, on airplanes, balloons, and satellites, etc.). The terminal equipment can be a user equipment (UE), and the UE includes a handheld device, a vehicle-mounted device, a wearable device, or a computing device with wireless communication function. Exemplarily, the UE can be a mobile phone, a tablet computer, or a computer with wireless transceiver function. The terminal equipment can also be a virtual reality (VR) terminal equipment, an augmented reality (AR) terminal equipment, a wireless terminal in industrial control, a wireless terminal in unmanned driving, a wireless terminal in telemedicine, a wireless terminal in a smart grid, a wireless terminal in a smart city, and / or a wireless terminal in a smart home, etc.

[0165] In the embodiment of the present application, the device for realizing the function of the terminal device may be a terminal device, or a device capable of supporting the terminal device to realize the function, such as a chip system, which may be installed in the terminal device. In the embodiment of the present application, the chip system may be composed of a chip, or may include a chip and other discrete devices. In the technical solution provided in the embodiment of the present application, the technical solution provided in the embodiment of the present application is described by taking the terminal device as an example in which the device for realizing the function of the terminal is a terminal device.

[0166] 2) Access network equipment is a radio access network (RAN) node that connects terminal devices to the wireless network. At present, some examples of RAN nodes are: next generation NodeB (gNB), transmission reception point (TRP), evolved NodeB (eNB), radio network controller (RNC), NodeB (NB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home evolved NodeB, or home NodeB, HNB), base band unit (BBU), or wireless fidelity (WiFi) access point (AP).

[0167] 3) Access and mobility management function (AMF) network element: It belongs to the core network element and is mainly responsible for signaling processing, such as access control, mobility management, registration and deregistration. When the AMF network element provides services for a session in the UE, it will provide storage resources on the control plane for the session to store the session identifier, the SMF network element identifier associated with the session identifier, etc. In this application, AMF can also be a mobility management entity (MME).

[0168] 4) Session management function (SMF) network element: responsible for user plane network element selection, user plane network element redirection, Internet Protocol (IP) address allocation between networks, session establishment, modification and release, and quality of service (QoS) control. In this application, SMF can also be a serving gateway (S-GW).

[0169] 5) User plane function (UPF) network element: responsible for forwarding and receiving user data of terminal devices. User data can be received from the data network (DN) and transmitted to the terminal device through the access network device; the UPF network element can also receive user data from the terminal device through the access network device and forward it to the data network. The transmission resources and scheduling functions that provide services to terminal devices in the UPF network element are managed and controlled by the SMF network element. In this application, UPF can also be a public data network gateway (P-GW). In this application, the functions of SMF and UPF can be integrated into the service gateway or the public data network gateway. SMF, UPF, S-GW and P-GW can be collectively referred to as data gateway devices, which interact with AMF or MME, so that the interaction between SMF and UPF and the interaction between S-GW and P-GW can be omitted. The data gateway device can cache downlink data.

[0170] Among them, the interface between UE and AMF network element is called N1 interface, the interface between AMF network element and RAN equipment is called N2 interface, the interface between RAN equipment and UPF network element can be called N3 interface, the interface between SMF network element and UPF network element is called N4 interface, the interface between UPF network element and DN is called N6 interface, the interface between SMF network element and PCF network element is called N7 interface, and the interface between AMF network element and SMF network element is called N11 interface.

[0171] The first network device, the second network device, the third network device, and the fourth network device in the present application can be respectively Figure 2 The UPF network element, RAN, AMF, and SMF shown in the figure may also be a network element having the functions of the above-mentioned UPF network element, RAN, AMF, and SMF network element in a future communication system.

[0172] For the convenience of explanation, in the following of this application, the first network device, the second network device, the third network device, and the fourth network device are respectively Figure 2 The UPF network element, RAN, AMF, and SMF network element in the example are used for explanation. Further, the AMF network element is referred to as AMF, the SMF network element is referred to as SMF, the UPF network element is referred to as UPF, and the terminal device is referred to as UE, and the access network device is referred to as RAN, that is, the AMF described later in this application can be replaced by a mobility management network element, the SMF can be replaced by a session management network element, the UPF can be replaced by a user plane network element, the UE can be replaced by a terminal device, and the RAN can be replaced by an access network device.

[0173] It should be noted that the above is only an example and is not a limitation on the first network device, the second network device, the third network device, and the fourth network device. For example, the first network device can also be other network elements that can receive downlink data from a terminal device, or can send downlink data from a terminal device to an access network device, and this embodiment of the present application does not limit this. Among them, the UPF can also be a protocol data unit (PDU) session anchor (PSA) UPF or a downlink classifier user plane network element (DLCL UPF), etc., and this embodiment of the present application does not limit this.

[0174] Next, the technical solution of the embodiments of the present application will be introduced in conjunction with specific embodiments.

[0175] Embodiment 1 (UPF-drx)

[0176] Figure 3 A data transmission method implemented in the present application is shown, which can be applied to Figure 2In the network structure shown in Figure 3 As shown, the method may include the following process:

[0177] Step S301: The access network device sends first information to the AMF, where the first information is used by the UPF to determine the time for sending downlink data of the UE to the access network device. Accordingly, the AMF receives the first information from the access network device.

[0178] Optionally, the first information may also include UE information, such as an identifier of the UE, so that when the UPF receives the downlink data of the UE, it sends the downlink data to the access network device of the UE according to the first information corresponding to the identifier of the UE. It can be understood that if the access network device configures the same eDRX for different UEs, the first information may not include the UE information. If the first information may not include the UE information, the UE in this application may be any UE under the access network device that sends the first information. If there are multiple UEs under the access network device, the steps shown in the method for data transmission provided in the embodiment of the present application are performed for each UE.

[0179] Step S302: AMF sends the first information to SMF, and correspondingly, SMF receives the first information from AMF.

[0180] Step S303: SMF sends the first information to UPF, and correspondingly, UPF receives the first information from SMF.

[0181] Step S304: UPF sends the UE's downlink data to the access network device according to the first information.

[0182] Exemplarily, the UPF receives the downlink data of the UE, determines the latest sending time of the downlink data according to the first information, and sends the downlink data to the access network device within a preset time before the latest sending time. Among them, the latest sending time can be understood as the deadline for the UPF to store the downlink data. The UPF sends the downlink data to the access network device at the latest sending time, so that when the access network device receives the downlink data, the paging opportunity of the UE arrives, so that the time for the access network device to store the downlink data is as short as possible. If the UPF sends the downlink data after the latest sending time, the access network device may need to store the downlink data until the paging opportunity of the UE arrives, causing the access network device to store the downlink data of the UE for too long. Specifically, the latest sending time can be determined according to the wake-up time of the terminal device. Exemplarily, the latest sending time can be the wake-up time of the UE after the UPF receives the downlink data of the UE. For example, the start time of DRX (PTW), or the end time of PTW, or any time within PTW, or the start time of any PO within PTW, or the end time of any PO within PTW, or any time included in any PO within PTW, which is not limited in the embodiments of the present application. The preset duration refers to a time period of a preset length before the latest sending time, which can be preset or defined by a protocol, or preconfigured according to prior information, which is not limited in the embodiments of the present application.

[0183] The process of sending downlink data according to the first information is introduced below with reference to a specific example.

[0184] Example 1: The first information includes an eDRX cycle.

[0185] The eDRX cycle may also be a wake-up cycle of the UE or a discontinuous reception DRX cycle or a sleep cycle of the UE; the following description is given by taking the example that the first information includes the eDRX cycle.

[0186] In a possible implementation, UPF can determine a third time based on the eDRX cycle and the time of receiving the first information, and UPF sends the downlink data to the access network device before the third time, wherein the third time is the eDRX cycle boundary or the eDRX cycle start time after UPF receives the downlink data.

[0187] like Figure 4As shown, the access network device sends the first information at t1, and the UPF receives the first information at t2. If the UPF receives downlink data at t3, the UPF determines the third time, i.e., t5, according to t2 and the eDRX cycle, and the UPF sends the downlink data to the access network device at t4 before t5; if the UPF receives downlink data at t6, the UPF determines the third time, i.e., t8, according to t2 and the eDRX cycle, and the UPF sends the downlink data to the access network device at t7 before t8; if the UPF receives downlink data at t9, the UPF determines the third time, i.e., t11, according to t2 and the eDRX cycle, and the UPF sends the downlink data to the access network device at t10 before t11.

[0188] Exemplarily, t5 can be understood as the latest sending time, and the interval between t5 and t4 can be understood as the preset time. UPF can send downlink data to the access network device at the preset time before t5, i.e., t4. Optionally, UPF can also send downlink data to the access network device at any time between t4 and t5, and the repetitive parts will not be repeated below.

[0189] It should be noted that Figure 4 This is only an example and does not constitute a limitation on the time when the access network device sends the first information and the time when the UPF receives the first information in the embodiment of the present application. In one implementation, t1 can be equal to t2.

[0190] In a possible implementation, the UPF may determine a fourth time according to the eDRX cycle and the time of receiving the first information, and the UPF sends the downlink data to the access network device at the fourth time, wherein the fourth time is the time before the eDRX cycle boundary or the eDRX cycle start time (just before) after the UPF receives the downlink data. Figure 5 As shown, the access network device sends the first information at t1, and the UPF receives the first information at t2. If the UPF receives downlink data at t3, the UPF determines the fourth time according to t2 and the eDRX cycle, that is, t4, and the UPF sends the downlink data to the access network device at t4. For example, the UPF determines the fourth time according to t2, eDRX, and the time advance for sending downlink data. If the UPF receives downlink data at t6, the UPF determines the fourth time according to t2 and the eDRX cycle, that is, t7, and the UPF sends the downlink data to the access network device at t7; if the UPF receives downlink data at t9, the UPF determines the fourth time according to t2 and the eDRX cycle, that is, t10, and the UPF sends the downlink data to the access network device at t10.

[0191] It should be noted that Figure 5This is only an example and does not constitute a limitation on the time when the access network device sends the first information and the time when the UPF receives the first information in the embodiment of the present application. In one implementation, t1 can be equal to t2.

[0192] Example 2: The first information may include an eDRX cycle and a PTW duration;

[0193] In a possible implementation, the UPF determines the time when the first information is received as the start time of the eDRX cycle and the PTW, and the UPF may determine the third time according to the eDRX cycle, the PTW duration, and the time when the first information is received, and the UPF sends the downlink data to the access network device before the third time. For example, the UPF sends the downlink data to the access network device within the PTW before the third time, wherein the third time is the end time of the PTW after the UPF receives the downlink data. Figure 6 As shown, the access network device sends the first information at t1, and the UPF receives the first information at t2. If the UPF receives the downlink data at t9, the UPF determines the third time, i.e., t11, according to t2, the eDRX cycle and the PTW, and the UPF sends the downlink data to the access network device at t10 before t11.

[0194] It should be noted that Figure 6 This is only an example and does not constitute a limitation on the time when the access network device sends the first information and the time when the UPF receives the first information in the embodiment of the present application. In one implementation, t1 can be equal to t2.

[0195] In a possible implementation, the UPF determines the time when the first information is received as the start time of the eDRX cycle and the PTW, and the UPF may determine the fourth time according to the eDRX cycle, the PTW duration, and the time when the first information is received, and the UPF sends the downlink data to the access network device at the fourth time, wherein the fourth time is the time before the PTW ends (just before), for example, the fourth time is the time within the PTW. Figure 7 As shown, the access network device sends the first information at t1, and the UPF receives the first information at t2. If the UPF receives downlink data at t9, the UPF determines the fourth time, i.e., t10, according to t2, the eDRX cycle and the PTW, and the UPF sends the downlink data to the access network device at t10.

[0196] It should be noted that Figure 7 This is only an example and does not constitute a limitation on the time when the access network device sends the first information and the time when the UPF receives the first information in the embodiment of the present application. In one implementation, t1 can be equal to t2.

[0197] In a possible implementation, the UPF determines the time when the first information is received as the start time of the eDRX cycle and the end time of the PTW, and the UPF can determine the third time according to the eDRX cycle, the PTW duration, and the time when the first information is received, and the UPF sends the downlink data to the access network device before the third time. For example, the UPF sends the downlink data to the access network device within the PTW before the third time, wherein the third time is the end time of the PTW. Figure 8 As shown, the access network device sends the first information at t1, and the UPF receives the first information at t2. If the UPF receives the downlink data at t9, the UPF determines the third time, i.e., t11, according to t2, the eDRX cycle and the PTW, and the UPF sends the downlink data to the access network device at t10 before t11.

[0198] It should be noted that Figure 8 This is only an example and does not constitute a limitation on the time when the access network device sends the first information and the time when the UPF receives the first information in the embodiment of the present application. In one implementation, t1 can be equal to t2.

[0199] In a possible implementation, the UPF determines the time when the first information is received as the start time of the eDRX cycle and the end time of the PTW, and the UPF can determine the fourth time according to the eDRX cycle, the PTW duration, and the time when the first information is received, and the UPF sends the downlink data to the access network device at the fourth time, wherein the fourth time is the time before the end of the PTW, for example, the fourth time is within the PTW. Fig. 9 As shown, the access network device sends the first information at t1, and the UPF receives the first information at t2. If the UPF receives downlink data at t9, the UPF determines the fourth time, i.e., t10, according to t2, the eDRX cycle and the PTW, and the UPF sends the downlink data to the access network device at t10.

[0200] It should be noted that Fig. 9 This is only an example and does not constitute a limitation on the time when the access network device sends the first information and the time when the UPF receives the first information in the embodiment of the present application. In one implementation, t1 can be equal to t2.

[0201] In a possible implementation, the UPF determines the time when the first information is received as the start time of the eDRX cycle and the end time of the PTW, and the UPF can determine the fourth time according to the eDRX cycle, the PTW duration, and the time when the first information is received, and the UPF sends the downlink data to the access network device at the fourth time, wherein the fourth time is the time before the PTW. Fig.10As shown, the access network device sends the first information at t1, and the UPF receives the first information at t2. If the UPF receives downlink data at t9, the UPF determines the fourth time, i.e., t10, according to t2, the eDRX cycle and the PTW, and the UPF sends the downlink data to the access network device at t10.

[0202] It should be noted that Fig.10 This is only an example and does not constitute a limitation on the time when the access network device sends the first information and the time when the UPF receives the first information in the embodiment of the present application. In one implementation, t1 can be equal to t2.

[0203] In the present application, the eDRX cycle may be a paging occasion (PO) cycle, such as Fig.11a Alternatively, the eDRX cycle is a paging time window (PTW) cycle, wherein the PTW includes one or more POs, such as Fig.11b shown.

[0204] Example 3: The first information may include an eDRX cycle and a first duration;

[0205] In a possible implementation manner, the first duration is used to indicate at least one of the following:

[0206] (1) the time interval between the time when the access network device sends the first information and the next eDRX cycle boundary;

[0207] (2) The time interval to the next PTW;

[0208] (3) The time interval to the next paging opportunity PO.

[0209] The UPF determines the third time according to the first duration and the eDRX cycle, wherein the third time is the eDRX cycle boundary after the UPF receives the downlink data. Fig.12 As shown, the access network device sends the first information at t1, the UPF receives the first information at t2, the UPF receives the downlink data at t9, and the UPF determines t1 according to t2 and the transmission delay of the first information (the time difference between t1 and t2), and then determines the eDRX cycle boundary according to the first duration L, and determines the third time t11 according to the determined eDRX cycle boundary and the eDRX cycle. Exemplarily, if t1 is equal to t2, the UPF directly determines the third time t11 according to t1, L and the eDRX cycle. The UPF sends downlink data to the access network device at t10 before the third time.

[0210] In a possible implementation, the first duration is used to indicate the time interval between the time when the access network device sends the first information and the next eDRX cycle boundary. The UPF determines the fourth time according to the first duration and the eDRX cycle, wherein the fourth time is the time before the eDRX cycle boundary after the UPF receives the downlink data. Fig.13 As shown, the access network device sends the first information at t1, the UPF receives the first information at t2, the UPF receives the downlink data at t9, and the UPF determines t1 based on t2 and the transmission delay of the first information, and then determines the eDRX cycle boundary based on t1 and the first duration L, and determines the fourth time, i.e., t10, based on the determined eDRX cycle boundary and the eDRX cycle. Exemplarily, if t1 is equal to t2, the UPF directly determines the fourth time t10 based on t1, L and the eDRX cycle. The UPF sends downlink data to the access network device at the fourth time t10.

[0211] In the above manner, the UPF sends the downlink data of the UE to the access network device according to the first information, and can wake up the UE (just

[0212] Before sending the UE's downlink data to the access network device, the storage burden of the access network device can be effectively alleviated.

[0213] Example three: The first information includes the eighth indication information.

[0214] Specifically, the eighth indication information may be used to indicate suspension of sending downlink data to the UE.

[0215] After receiving the eighth indication information, the UPF stops sending downlink data to the UE.

[0216] Example 4: The first information includes the eighth indication information and the second duration.

[0217] After receiving the eighth indication information, the UPF suspends sending downlink data to the UE, wherein the suspension time is the second duration.

[0218] If the UPR buffers the downlink data of the UE, the buffered downlink data may be sent to the UE after pausing for the second time period.

[0219] Example 5: The first information includes ninth indication information.

[0220] Specifically, the ninth indication information may be used to indicate the resumption of sending downlink data to the UE.

[0221] After receiving the ninth indication information, UPF resumes sending downlink data to the UE. For example, UPF first receives the eighth indication information, UPF suspends sending downlink data to the UE, and then, UPF receives the ninth indication information, then UPF resumes sending downlink data to the UE. For another example, UPF first receives the eighth indication information and the second duration, UPF suspends sending downlink data to the UE, and the suspension duration is the second duration. If the ninth indication information is received within the second duration, then after receiving the ninth indication information, UPF can send downlink data to the UE.

[0222] Embodiment 2 (SMF-drx)

[0223] Fig.14 A data transmission method implemented in the present application is shown, which can be applied to Figure 2 In the system architecture shown in Fig.14 As shown, the method may include the following process:

[0224] Step S1401: the access network device sends first information to the AMF, where the first information is used by the SMF to determine the time for instructing the UPF to send downlink data of the UE. Accordingly, the AMF receives the first information from the access network device;

[0225] Exemplarily, the first information may be the above Figures 4 to 13 After receiving the first information, SMF can execute the process steps of UPF in the above embodiment to determine the time when SMF sends the downlink data of UE, which will not be repeated in the following embodiments.

[0226] Step S1402: AMF sends first information to SMF, and correspondingly, SMF receives the first information from AMF;

[0227] Step S1403: SMF sends first indication information to UPF, where the first indication information is used to indicate the following a1 or a2 or a3 to UPF.

[0228] a1: When receiving downlink data from UE:

[0229] (1) Buffering UE downlink data, and

[0230] (2) Sending second indication information to the SMF, where the second indication information is used to indicate that the UPF has downlink data of the UE.

[0231] Exemplarily, the UPF has the downlink data of the UE, and the UPF may have cached the downlink data, or the UPF may have (just) received the downlink data.

[0232] a2: When receiving downlink data from the UE, cache the downlink data from the UE.

[0233] a3: When receiving downlink data from the UE, the downlink data is sent to the SMF.

[0234] The "cache" in the embodiments of the present application can be understood as temporary storage, and the cache described in this article can also be replaced by storage.

[0235] The above design can instruct UPF to perform different operations through the first indication information, so that the data transmission method in the embodiment of the present application is more flexible. For example, the first indication information is used to indicate a1, and UPF will not directly send the downlink data to the access network device when receiving the downlink data of the UE. The downlink data can be cached by UPF to reduce the storage burden of the access network device. In addition, UPF can determine the sending time of the downlink data by itself, and UPF sends the downlink data to the access network device at the determined sending time, thereby reducing the delay of the terminal device receiving the downlink data on the basis of reducing the storage burden of the access network device. UPF can also notify SMF through the second indication information that UPF has the downlink data of the UE cached. After receiving the second indication information, SMF determines the sending time of the downlink data for UPF, thereby saving the calculation overhead of UPF. For another example, the first indication information is used to indicate a3, and UPF can also send the received downlink data to SMF, and SMF caches the downlink data to share the storage burden of the access network device, and at the same time share the storage burden of UPF.

[0236] In a possible implementation, step S1403 may be performed before step S1401 or S1402.

[0237] Step S1404: UPF receives downlink data from UE. This step is optional.

[0238] The first optional implementation method:

[0239] If the UPF receives the downlink data in step S1404 and the first indication information is used to indicate a1, steps S1405b, S1406b, S1407b and S1409 are executed.

[0240] Step S1405b: UPF caches the downlink data.

[0241] Step S1406b: When receiving the downlink data, the UPF sends the second indication information to the SMF.

[0242] Step S1407b: If the SMF receives the second indication information, the SMF sends third indication information to the UPF according to the second indication information and the first information, and the third indication information is used to instruct the UPF to send the downlink data.

[0243] If the SMF does not receive the second indication information, the SMF sends the third indication information to the UPF according to the first information.

[0244] Step S1409: UPF sends the UE's downlink data to the access network device according to the third indication information.

[0245] In a possible implementation, when the UPF receives the third indication information, the UPF sends the downlink data of the UE to the access network device.

[0246] In summary, when UPF receives downlink data, UPF caches the downlink data, and UPF sends a second indication message to SMF to indicate that UPF has cached downlink data. SMF determines the time for UPF to send the downlink data of the UE based on the first information received in step S1402, and notifies UPF through the third indication message. UPF sends the cached downlink data based on the third indication message.

[0247] The second optional implementation method:

[0248] If the UPF receives the downlink data in step S1404 and the first indication information is used to indicate a2, steps S1405b, S1407b and S1409 are executed.

[0249] A third optional implementation method:

[0250] If the UPF receives the downlink data in step S1404 and the first indication information is used to indicate a3, steps S1405a, S1406a, S1407a and S1409 are executed.

[0251] Step S1405a: UPF sends the downlink data to SMF.

[0252] Step S1406a: SMF buffers the downlink data.

[0253] Step S1407a: SMF sends the downlink data to UPF according to the first information.

[0254] A fourth optional implementation method:

[0255] If the UPF does not receive the downlink data in step S1404 (or step S1404 is not executed in this embodiment) and the first indication information is used to indicate a2, steps S1407b and S1408 are executed.

[0256] Step S1408: UPF sends fourth indication information to AMF based on the third indication information, where the fourth indication information is used to indicate that the downlink data has not been received.

[0257] Exemplarily, the SMF determines the time that can be used for the UPF to send the downlink data of the UE based on the first information. It is assumed here that the SMF does not know whether the UPF has cached downlink data. The SMF can periodically send a third indication message to the UPF to notify the UPF to send the downlink data when the third indication message is received or cached. When the UPF receives the third indication message sent by the SMF, if the UPF has no cached downlink data, the UPF can send a fourth indication message to the SMF. The SMF determines whether to send the third indication message to the UPF again based on the fourth indication message.

[0258] It should be noted that, for the convenience of description, the information with the same name in the embodiments listed in this application is not necessarily the same information, and the function of the information is limited by the respective embodiments.

[0259] Embodiment 3 (AMF-drx)

[0260] Fig.15 A data transmission method implemented in the present application is shown, which can be applied to Figure 2 In the system architecture shown in Fig.15 As shown, the method may include the following process:

[0261] Step S1501: The access network device sends first information to the AMF, where the first information is used by the AMF to determine the time for instructing the SMF or UPF to send downlink data of the UE. Accordingly, the AMF receives the first information from the access network device;

[0262] Step S1502: AMF sends fifth indication information to SMF according to the first information, and the fifth indication information is used to indicate the following a1 or a2 to SMF.

[0263] a1: When receiving downlink data from UE:

[0264] (1) Buffering UE downlink data, and

[0265] (2) Sending second indication information, where the second indication information is used to indicate that there is downlink data of the UE.

[0266] a2: When receiving downlink data from the UE, cache the downlink data from the UE.

[0267] Step S1503: SMF sends first indication information to UPF, where the first indication information is used to indicate a1, a2 or a3 to UPF.

[0268] a3: When receiving the downlink data, send the downlink data to SMF.

[0269] Specifically, if the fifth indication information is used to indicate a1, the fifth indication information is used to indicate SMF to send the second indication information to AMF. When the first indication information is used to indicate a1, the first indication is used to indicate UPF to send the second indication information to SMF, and the repetitive parts are not repeated hereafter.

[0270] The above design instructs SMF to perform different operations through the fifth indication information, and instructs UPF to perform different operations through the first indication information, so as to reduce the delay of the terminal device in receiving downlink data on the basis of reducing the storage burden of the access network device, thereby making the data transmission method in the embodiment of the present application more flexible.

[0271] In a possible implementation, step S1503 may be performed before step S1501 or S1502.

[0272] Step S1504: UPF receives downlink data from UE. This step is optional.

[0273] The first optional implementation method:

[0274] If in step S1504, the UPF receives the downlink data and the fifth indication information is used to indicate a1 and the first indication information is used to indicate a1, steps S1505b, S1506b, S1507, S1508, S1509b and S1512 are executed.

[0275] Step S1505b: UPF caches the downlink data.

[0276] Step S1506b: When receiving the downlink data, the UPF sends the second indication information to the SMF.

[0277] Step S1507: SMF sends the second indication information to AMF.

[0278] Step S1508: If the AMF receives the second indication information, the AMF sends third indication information to the SMF according to the second indication information and the first information, where the third indication information is used to indicate the sending of the downlink data.

[0279] If the AMF does not receive the second indication information, the AMF sends the third indication information to the SMF according to the first information.

[0280] Step S1509b: SMF sends the third indication information to UPF.

[0281] Step S1512: UPF sends the downlink data to the access network device according to the third indication information.

[0282] The second optional implementation method:

[0283] If in step S1504, the UPF receives the downlink data and the fifth indication information is used to indicate a1 and the first indication information is used to indicate a3, steps S1505a, S1506a, S1507, S1508, S1509a and S1512 are executed.

[0284] Step S1505a: When receiving the downlink data, the UPF sends the downlink data to the SMF according to the first indication information.

[0285] Step S1506a: The SMF caches the downlink data.

[0286] Step S1509a: The SMF sends the downlink data to the UPF according to the third indication information.

[0287] The other steps are the same as the corresponding steps in the first optional implementation.

[0288] A third optional implementation method:

[0289] If in step S1504, the UPF receives the downlink data and the fifth indication information is used to indicate a2 and the first indication information is used to indicate a1, steps S1505b, S1506b, S1508, S1509b and S1512 are executed.

[0290] A fourth optional implementation method:

[0291] If in step S1504, the UPF receives the downlink data and the fifth indication information is used to indicate a2 and the first indication information is used to indicate a2, steps S1505b, S1508, S1509b and S1512 are executed.

[0292] A fifth optional implementation:

[0293] If in step S1504, the UPF receives the downlink data and the fifth indication information is used to indicate a2 and the first indication information is used to indicate a3, steps S1505a, S1506a, S1508, S1509a and S1512 are executed.

[0294] A sixth optional implementation method:

[0295] If the UPF does not receive the downlink data in step S1504 (or step S1504 is not executed in this embodiment) and the fifth indication information is used to indicate a2 and the first indication information is used to indicate a2, then steps S1508, S1509b, S1510 and S1511 are executed.

[0296] Step S1510: UPF sends fourth indication information to SMF, where the fourth indication information is used to indicate that the downlink data has not been received.

[0297] Step S1511: SMF sends the fourth indication information to AMF.

[0298] A seventh optional implementation method:

[0299] If the UPF does not receive the downlink data in step S1504 (or step S1504 is not executed in this embodiment) and the fifth indication information is used to indicate a2 and the first indication information is used to indicate a3, steps S1508 and S1511 are executed.

[0300] As mentioned above, the first indication information in indication a3 is used to instruct UPF to send downlink data to the SMF cache. Therefore, AMF can send third indication information to SMF when it is not sure whether SMF has cached downlink data, indicating the time when SMF can send cached downlink data to UPF. Step S1508 can be executed once, or step S1508 can be executed periodically. SMF can send fourth indication information to AMF when no downlink data is cached.

[0301] Embodiment 4 (RAN-drx)

[0302] Fig.16 A data transmission method implemented in the present application is shown, which can be applied to Figure 2 In the system architecture shown in FIG. 1 , in this embodiment, the access network device determines the time to send the downlink data according to the first information, such as Fig.16 As shown, the method may include the following process:

[0303] Step S1601: The access network device sends the fifth indication information to the AMF.

[0304] Step S1602: AMF sends the fifth indication information to SMF, and the fifth indication information is used to indicate the following a1 or a2 to SMF.

[0305] a1: When receiving downlink data from UE:

[0306] (1) Buffering UE downlink data, and

[0307] (2) Sending second indication information, where the second indication information is used to indicate that there is downlink data of the UE.

[0308] a2: When receiving downlink data from the UE, cache the downlink data from the UE.

[0309] Step S1603: SMF sends first indication information to UPF, where the first indication information is used to indicate a1, a2 or a3 to UPF.

[0310] a3: When receiving the downlink data, send the downlink data to SMF.

[0311] In a possible implementation, step S1603 may be performed before step S1601 or S1602.

[0312] Step S1604: UPF receives downlink data from UE. This step is optional.

[0313] The first optional implementation method:

[0314] If in step S1604, the UPF receives the downlink data and the fifth indication information is used to indicate a1 and the first indication information is used to indicate a1, steps S1605b, S1606b, S1607, S1608, S1609b and S1612 are executed.

[0315] Step S1605b: UPF caches the downlink data.

[0316] Step S1606b: When receiving the downlink data, the UPF sends the second indication information to the SMF.

[0317] Step S1607: SMF sends the second indication information to AMF, and AMF sends the second indication information to the access network device.

[0318] Step S1608: When the access network device receives the second indication information, the access network device sends third indication information to AMF based on the second indication information and the first information, and AMF sends the third indication information to SMF, where the third indication information is used to indicate the sending of the downlink data.

[0319] Step S1609b: SMF sends the third indication information to UPF.

[0320] Step S1612: UPF sends the downlink data to the access network device according to the third indication information.

[0321] The second optional implementation method:

[0322] If in step S1604, the UPF receives the downlink data and the fifth indication information is used to indicate a1 and the first indication information is used to indicate a3, steps S1605a, S1606a, S1607, S1608, S1609a and S1612 are executed.

[0323] Step S1605a: When receiving the downlink data, the UPF sends the downlink data to the SMF according to the first indication information.

[0324] Step S1606a: The SMF caches the downlink data.

[0325] Step S1609a: The SMF sends the downlink data to the UPF according to the third indication information.

[0326] The other steps are the same as the corresponding steps in the first optional implementation.

[0327] A third optional implementation method:

[0328] If in step S1604, the UPF receives the downlink data and the fifth indication information is used to indicate a2 and the first indication information is used to indicate a1, steps S1605b, S1606b, S1608, S1609b and S1612 are executed.

[0329] A fourth optional implementation method:

[0330] If in step S1604, the UPF receives the downlink data and the fifth indication information is used to indicate a2 and the first indication information is used to indicate a2, steps S1605b, S1608, S1609b and S1612 are executed.

[0331] A fifth optional implementation:

[0332] If in step S1604, the UPF receives the downlink data and the fifth indication information is used to indicate a2 and the first indication information is used to indicate a3, steps S1605a, S1606a, S1607, S1608, S1609a and S1612 are executed.

[0333] A sixth optional implementation method:

[0334] If the UPF does not receive the downlink data in step S1604 (or step S1604 is not executed in this embodiment) and the fifth indication information is used to indicate a2 and the first indication information is used to indicate a2, then steps S1608, S1609b, S1610 and S1611 are executed.

[0335] Step S1610: UPF sends fourth indication information to SMF, where the fourth indication information is used to indicate that the downlink data has not been received.

[0336] Step S1611: SMF sends the fourth indication information to AMF, and AMF sends the fourth indication information to the access network device.

[0337] A seventh optional implementation method:

[0338] If the UPF does not receive the downlink data in step S1604 (or step S1604 is not executed in this embodiment) and the fifth indication information is used to indicate a2 and the first indication information is used to indicate a3, steps S1608 and S1611 are executed.

[0339] Example 5 (RNAU)

[0340] Fig.17 Another data transmission method provided in the embodiment of the present application can be applied to Figure 2 In the system architecture shown, the method can be applied alone, or combined with the above embodiments, for example, after the following steps:

[0341] (1) Step S301, S302 or S303 of Embodiment 1, or

[0342] (2) Steps S1401, S1402, S1403, S1404, S1405a, S1406a or S1405b of Embodiment 2, or

[0343] (3) Steps S1501, S1502, S1503, S1504, S1505a, S1506a or S1505b of Embodiment 3, or

[0344] (4) Steps S1601, S1602, S1603, S1604, S1605a, S1606a or S1605b of Embodiment 4.

[0345] like Fig.17 As shown, the method may include the following process:

[0346] Step S1701: The access network device sends second information to the AMF, where the second information is used to indicate to the UPF that the UE is reachable. Correspondingly, the AMF receives the second information from the access network device.

[0347] The reachable here means that the terminal device can currently receive downlink data from the network side, for example, the terminal device is in the RRC connected state, or the terminal device requests to enter the RRC connected state.

[0348] Step S1702: AMF sends the second information to SMF, and correspondingly, SMF receives the second information from AMF.

[0349] Step S1703: SMF sends the second information to UPF, and correspondingly, UPF receives the second information from SMF.

[0350] Step S1704: UPF sends the UE's downlink data to the access network device according to the second information.

[0351] Exemplarily, before receiving the second information, UPF stores (or caches) the downlink data of the UE. After receiving the second information, it determines that the UE is reachable and sends the cached downlink data to the access network device of the UE. Another exemplary example is that if UPF caches the downlink data of the UE, when UPF receives the second information, UPF can send second indication information to SMF, and the second indication information is used to indicate that there is downlink data of the UE. If UPF does not cache the downlink data of the UE, when UPF receives the second information, it can send fourth indication information to SMF, and the fourth indication information is used to indicate that there is no downlink data of the UE or to indicate that the UE can be released.

[0352] It should be noted that the various embodiments provided in the present application can be used alone or in combination with each other. For example, some steps of Embodiment 1 are combined with some steps of Embodiment 2 to form new embodiments, which are all within the protection scope of the present application. For another example, specifically (step S301 in Embodiment 1) the access network device can send the first information to AMF, and AMF and SMF send the first information to UPF. When UPF receives the downlink data from the UE, UPF determines the sending time of the downlink data according to the first information. If, while waiting for the sending time, (steps S1701, S1702, S1703 in Embodiment 5) UPF receives the second information, then UPF determines that the UE to which the downlink data to be sent belongs is reachable according to the second information, and (step S1704 in Embodiment 5) UPF sends the downlink data to the access network device. Fig.18 As shown, UPF receives the downlink data of the UE at t9, and determines that the sending time of the downlink data is t11 according to the first information. If UPF receives the second information at t10, UPF determines that the UE is reachable according to the second information, and sends the downlink data to the access network device. In one possible implementation, UPF sends the downlink data to the access network device before t10 or t11.

[0353] The above method increases the flexibility of UPF in sending UE's downlink data to the access network equipment and reduces the delay of the terminal equipment in receiving downlink data.

[0354] The following is a detailed description of the embodiments (Example 6 to Example 8). Figure 3 or Fig.17 The scheme of the embodiment shown is described in detail.

[0355] Example 6 (Capability)

[0356] In the sixth embodiment, when the UE is in the RRC inactive state, the UPF sends downlink data to the access network device as an example. Figure 3 The data transmission method provided in the embodiment of the present application is introduced. Fig.19 Schematic diagram of the flow chart corresponding to the data transmission method provided in the embodiment of the present application. Fig.19 As shown, the method includes:

[0357] Step S1901: The access network device sends the sixth indication information to the AMF, and correspondingly, the AMF receives the sixth indication information from the access network device.

[0358] The sixth indication information is used to indicate the load state of the access network device, or the sixth indication information is used to indicate that the access network device supports sending the first information to the core network device, or the sixth indication information is used to indicate the ability of the access network device to report the first information. This embodiment can be applied alone or in combination with the above embodiment. For example, the access network device can determine whether to execute the steps of the following embodiment through the sixth indication information:

[0359] (1) Step S301 of Embodiment 1, or,

[0360] (2) Step S1401 of the second embodiment, or,

[0361] (3) Step S1501 of Embodiment 3, or,

[0362] (4) Step S1601 of the fourth embodiment,

[0363] To alleviate the storage load of access network equipment.

[0364] Optionally, the sixth indication information may be, but is not limited to, carried in at least one of the following messages:

[0365] NG setup request, RAN configuration update, AMF configuration update acknowledge, NG reset acknowledge.

[0366] Step S1902: AMF sends the seventh indication information to the access network device, where the seventh indication information is used to indicate that the access network device can send the first information to the core network device. Correspondingly, the access network device receives the seventh indication information from the AMF.

[0367] The seventh indication information here can be understood as 1) used to characterize that the core network device has the ability to send UE's downlink data to the access network device according to the first information, and / or 2) instructing the access network device to send the first information to the core network device.

[0368] Optionally, the seventh indication information may be, but is not limited to, carried in at least one of the following messages:

[0369] NG setup response, RAN configuration update acknowledge, AMF configuration update, NG reset, AMF status indication, Overload Start, OverloadStop.

[0370] It should be noted that the present application has no strict restrictions on the execution order of step S1901. For example, step S1901 can also be executed after step S1902, that is, step S1902 is executed first, and then step S1901. In addition, the above steps S1901 and S1902 are optional steps.

[0371] Step S1903: The access network device sends configuration information of the eDRX cycle to the UE.

[0372] Specifically, the access network device may send the configuration information of the eDRX cycle to the UE before the UE switches to the RRC inactive state. For example, the configuration information of the eDRX cycle may be carried in an RRC release message, and the RRC release message is used to release the UE from the RRC connected state to the RRC inactive state.

[0373] Exemplarily, the configuration information of the eDRX cycle includes the duration information of the eDRX cycle, and may also include PTW duration information and the like.

[0374] After step S1902 or S1903, the first embodiment, the second embodiment, the third embodiment or the fourth embodiment is executed. During the execution of the first embodiment, the second embodiment, the third embodiment or the fourth embodiment, the fifth embodiment, the seventh embodiment or the eighth embodiment may be executed.

[0375] After executing the above-mentioned embodiment 1, embodiment 2, embodiment 3 or embodiment 4, if the access network device receives the downlink data from the UPF, step S1904 is executed.

[0376] Step S1904: The access network device sends a paging message to the UE, and after establishing an RRC connection with the UE, sends the downlink data of the UE received from the UPF to the UE.

[0377] After executing Example 5, Example 7 or Example 8, if the access network device receives the downlink data or the second information from the UPF, execute step S1905a, or S1905b, or S1905c.

[0378] Step S1905a: If the access network device receives the downlink data or the second information, and the access network device receives the RRC resume request message sent by the terminal device, the access network device sends an RRC resume message and the downlink data to the terminal device; wherein, the RRC resume message and the downlink data may be sent through one message or through different messages, which is not limited in this application.

[0379] Step S1905b: If the access network device receives the downlink data or the second information, and the access network device receives the RRC setup request (RRC setup request) message sent by the terminal device, the access network device sends an RRC setup (RRC setup) message and the downlink data to the terminal device; wherein, the RRC setup message and the downlink data can be sent through one message or through different messages, which is not limited in this application.

[0380] Step S1905c: If the access network device receives the downlink data or the second information, and the access network device receives an RRC setup complete message sent by the terminal device, the access network device sends the downlink data to the terminal device.

[0381] It should be understood that, through the embodiment of the present application, the time when the access network device receives the downlink data of the UE from the UPF is close to the time when the access network device can page the UE, and the access network device does not need to cache the downlink data of the UE for a long time.

[0382] Example 7 (RNAU)

[0383] In Embodiment 7, the data transmission method of the embodiment of the present application will be described by taking the UE requesting to enter the RRC connected state from the RRC inactive state, for example, taking the access network notification area update (ran notification area update, RNAU) process as an example.

[0384] The following is combined with Example 1 and Fig.17 The data transmission method provided in the embodiment of the present application is introduced. Fig. 20 Schematic diagram of the flow chart corresponding to the data transmission method provided in the embodiment of the present application. Fig. 20 As shown, the method includes:

[0385] Step S2001: the access network device sends an RRC release message to the UE. Correspondingly, the UE receives the RRC release message sent by the access network device and enters the RRC inactive state from the RRC connected state.

[0386] The RRC release message includes an RRC inactive state configuration (rrc-inactiveConfig), where the RRC inactive state configuration is used to indicate the configuration of the RRC inactive state, or the RRC inactive state configuration is used to indicate that the UE enters the RRC inactive state.

[0387] Step S2002: The UE sends an RRC resume request message (RRC Resume Request) to the access network device, where the RRC Resume Request is used by the UE to request the access network device to resume the RRC connection.

[0388] The RRC recovery request message includes a recovery cause indication (Resume Cause), and the recovery cause indication includes an access network notification area update indication (rna-Update).

[0389] In a possible implementation manner, the RRC resume request may be replaced by an RRC setup request message (RRC setup request.

[0390] Step S2003: The access network device sends second information to the AMF. In a possible implementation, the second information may be included in an RRC Inactive Transition Report message. The second information is used to indicate one of the following:

[0391] (1) the UE is converted from an RRC inactive state to an RRC connected state;

[0392] (2) the UE is about to transition from an RRC inactive state to an RRC connected state;

[0393] (3) The UE requests to restore the RRC connection;

[0394] (4) The UE requests to enter the RRC connected state;

[0395] (5) The UE can receive downlink data;

[0396] (6) The UE is reachable;

[0397] (7) The UE is online;

[0398] (8) The UE goes online;

[0399] (9) The UE is in an RRC connected state.

[0400] Step S2004: The AMF sends the second information to the SMF, and correspondingly, the SMF receives the second information sent by the AMF.

[0401] Case 1: There is downlink data in the cache

[0402] In combination with the above-mentioned embodiment one, embodiment two, embodiment three or embodiment four, if the SMF caches the downlink data, that is, step S0a, execute step S2005a; if the UPF caches the downlink data, that is, step S0b, execute step S2005b.

[0403] Step S2005a: The SMF sends the downlink data to the UPF.

[0404] Step S2005b: The SMF sends the second information to the UPF, and correspondingly, the UPF receives the second information sent by the SMF.

[0405] After step S2005a or S2005b, execute step S2009b.

[0406] Step S2009b: If the UPF caches the downlink data of the UE and receives the second information, or if the UPF receives the downlink data from the SMF, it sends the downlink data to the access network device.

[0407] In a possible implementation, in combination with the above-mentioned Example 1, Example 2, Example 3 or Example 4, if the SMF caches the downlink data, that is, step S0a, then step S2007 can also be executed after step S2004; if the UPF caches the downlink data, that is, step S0b, then steps S2006 and S2007 can also be executed after step S2005a or S2005b.

[0408] Step S2006: If the UPF caches the downlink data of the UE and receives the second information, the UPF sends fourth indication information to the SMF, where the fourth indication information is used to indicate one of the following:

[0409] (1) caching downlink data of the UE;

[0410] (2) The UE needs to enter the RRC connected state;

[0411] (3) The UE needs to restore the RRC connection;

[0412] (4) The UE may wait for downlink data;

[0413] (5) The UE does not need to immediately enter the RRC inactive state or the RRC idle state.

[0414] Step S2007: If the SMF caches the downlink data and receives the second information, or if the SMF receives the fourth indication information from the UPF, the SMF sends the fourth indication information to the AMF.

[0415] After step S2007, execute step S2008.

[0416] Step S2008: The AMF sends the fourth indication information to the access network device.

[0417] After step S2008 or S2009b, steps S2010b and S2011b are executed.

[0418] Step S2010b: If the access network device receives the downlink data or the fourth indication information, an RRC resumption message (RRC resume) is sent to the UE, where the RRC resume is used to resume the RRC connection of the UE.

[0419] In a possible implementation manner, the RRC resume may be replaced by an RRC setup message (RRC setup).

[0420] Step S2011b: The access network device sends the downlink data to the UE.

[0421] In a possible implementation, S2010b and S2011b may be combined into one step.

[0422] Case 2: Downlink data is not cached

[0423] In combination with the above-mentioned embodiment one, embodiment two, embodiment three or embodiment four, if the SMF does not cache the downlink data, execute step S2007; if the UPF does not cache the downlink data, execute steps S2005b and S2006.

[0424] Step S2005b: Same as S2005b in situation one.

[0425] Step S2006: If the UPF does not cache the downlink data of the UE and receives the second information, the UPF sends fourth indication information to the SMF, where the fourth indication information is used to indicate one of the following:

[0426] (1) No downlink data of the UE is cached;

[0427] (2) The UE does not need to enter the RRC connected state;

[0428] (3) The UE does not need to restore the RRC connection;

[0429] (4) The UE does not need to wait for downlink data;

[0430] (5) The UE may immediately enter the RRC inactive state or the RRC idle state.

[0431] Step S2007: If the SMF receives the fourth indication information from the UPF, or if the SMF does not cache the downlink data and receives the second information, the SMF sends the fourth indication information to the AMF.

[0432] After step S2007, steps S2008 and S2010a are executed.

[0433] Step S2008: The AMF sends the fourth indication information to the access network device.

[0434] Step S2010a: If the access network device receives the fourth indication information sent by the AMF, the access network device sends an RRC Release message to the UE, and the RRC release is used to release the RRC connection of the UE.

[0435] Through the above method, when the access network device receives the RRC recovery request message sent by the UE due to rna-Update, the access network device can notify the SMF or UPF through the AMF that the UE can receive downlink data, so that when the SMF or UPF caches the downlink data of the UE, it can send the downlink data of the UE to the access network device in time, and then the access network device sends the downlink data to the UE, avoiding paging the UE after the access network device receives the downlink data of the UE, so as to achieve the purpose of saving signaling overhead and equipment power consumption.

[0436] Embodiment 8 (TAU)

[0437] In Embodiment 8, the data transmission method of the embodiment of the present application is described by taking the UE switching from the RRC idle state to the RRC connected state as an example. Fig.14 The data transmission method provided in the embodiment of the present application is introduced. Fig.21 Schematic diagram of the flow chart corresponding to the data transmission method provided in the embodiment of the present application. Fig.21 As shown, the method includes:

[0438] Step S2101: the access network device sends an RRC release message to the UE. Correspondingly, the UE receives the RRC release message sent by the access network device and enters the RRC idle state from the RRC connected state.

[0439] After step S2101, execute step S2102a or S2102b.

[0440] Step S2102a: the UE sends an RRC resume complete message (RRC resumecomplete) or an RRC setup complete message (RRC setup complete) to the access network device.

[0441] After step S2102a, execute step S2103.

[0442] Step S2103: Same as step S2003.

[0443] Step S2102b: The UE sends a registration request message (Registration Requst) or a tracking area update request message (tracking area update request) to the AMF. The registration request message (Registration Requst) contains the tracking area identifier message (Last visited registered TAI) where the UE last resided and registered, which is used by the UE to update the tracking area identifier where the UE last resided and registered to the AMF.

[0444] After step S2103 or S2102b, execute step S2104.

[0445] Step S2104: Same as step S2004.

[0446] In a possible implementation, step S2104 may also be: the AMF sends the second information to the SMF according to the tracking area update request message or the registration request message.

[0447] If the SMF cache has the downlink data, execute steps S2105a, S2106, S2107, S2108, and S2109b. This process is the same as the process in which the SMF cache has the downlink data in Example 7 (i.e., execute steps S2005a, S2006, S2007, S2108, and S2109b), where S2106, S2107, and S2108 are optional steps.

[0448] If the UPF caches the downlink data, execute steps S2005b, S2006, S2007, S2008, and S2009b. This process is the same as the process in which the UPF caches the downlink data in Example 7 (i.e., execute steps S2005b, S2006, S2007, S2008, and S2009b), where S2106, S2107, and S2108 are optional steps.

[0449] After step S2108 or S2109b, step S2110b is executed, where step S2110b is the same as S2010b.

[0450] If the SMF does not cache the downlink data, execute steps S2107 and S2108. This process is the same as the process described in Example 7 where the SMF does not cache the downlink data (i.e., execute steps S1707 and S1708).

[0451] If the UPF does not cache the downlink data, execute steps S2105b, S2106, S2107, and S2108. This process is the same as the process in Example 7 where the UPF does not cache the downlink data (i.e., execute steps S2005b, S2006, S2007, and S2008).

[0452] After step S2108, execute step S2110a, where step S2110a is the same as S2010a.

[0453] Through the above method, when AMF receives the Registration Requst or tracking area update request or the second information sent by the UE, it can be determined that the UE is online, and AMF can notify the SMF or UPF of the online status of the UE, so that when the SMF or UPF caches the downlink data of the UE, it can send the downlink data of the UE to the access network device in time, and at the same time, it can notify the AMF and the access network device to keep the UE online, avoiding re-paging the UE after the access network device receives the downlink data of the UE, so as to achieve the purpose of saving signaling overhead and equipment power consumption.

[0454] Embodiment 9

[0455] In the ninth embodiment, the data transmission method of the embodiment of the present application is described by taking the first information including the eighth indication information as an example. Fig. 22 , Fig. 22 A data transmission method implemented in the present application is shown, which can be applied to Figure 2 In the system architecture shown in Fig. 22 As shown, the method may include the following process:

[0456] Step 2200: The access network device determines that the eDRX cycle is greater than a set threshold. This step is optional.

[0457] Step 2201: The access network device sends eighth indication information to the AMF, where the eighth indication information is used to indicate any one of the following:

[0458] a1, UPF suspends sending downlink data to UE.

[0459] a2, SMF instructs UPF to suspend sending downlink data to UE.

[0460] a3, AMF instructs SMF, and SMF instructs UPF to suspend sending downlink data to UE.

[0461] a4, AMF instructs UPF to suspend sending downlink data to UE.

[0462] The first optional implementation method:

[0463] Step 2202a, AMF sends the eighth indication information to SMF.

[0464] Step 2203a, SMF sends the eighth indication information to UPF, and the eighth indication information is used to indicate a1.

[0465] The second optional implementation method:

[0466] Step 2202b, AMF sends the eighth indication information to SMF, and the eighth indication information is used to indicate a2.

[0467] Step 2203b, SMF sends the tenth indication information to UPF, and the tenth indication information is used to indicate a1.

[0468] A third optional implementation: the eighth indication information is used to indicate a3.

[0469] Step 2202c, AMF sends the eleventh indication information to SMF, and the eleventh indication information is used to indicate a2.

[0470] Step 2203c, SMF sends the tenth indication information to UPF, and the tenth indication information is used to indicate a1.

[0471] A fourth optional implementation: the eighth indication information is used to indicate a4.

[0472] Step 2202d, AMF sends the twelfth indication information to UPF, and the twelfth indication information is used to indicate a1.

[0473] Step S2204: UPF receives downlink data from the UE and buffers the downlink data from the UE. This step is optional.

[0474] The above method can realize the control of UPF through different network elements. The implementation method is flexible, the interaction process is simple, and it has stronger applicability.

[0475] Optionally, after step S2204, the following process of resuming data transmission may also be performed, see Fig.23 , is a process for restoring data transmission, which includes the following steps:

[0476] Step 2301: The access network device sends ninth indication information to the AMF. The ninth indication information is used to indicate any one of the following:

[0477] b1, UPF resumes sending downlink data to UE.

[0478] b2, SMF instructs UPF to resume sending downlink data to the UE.

[0479] b3, AMF instructs SMF, and SMF instructs UPF to resume sending downlink data to the UE.

[0480] b4, AMF instructs UPF to resume sending downlink data to the UE.

[0481] The first optional implementation method:

[0482] Step 2302a, AMF sends the ninth indication information to SMF.

[0483] Step 2303a, SMF sends the ninth indication information to UPF, and the ninth indication information is used to indicate b1.

[0484] The second optional implementation method:

[0485] Step 2302b, AMF sends the ninth indication information to SMF, and the ninth indication information is used to indicate b2.

[0486] Step 2303b, SMF sends the thirteenth indication information to UPF, and the thirteenth indication information is used to indicate b1.

[0487] A third optional implementation: the ninth indication information is used to indicate b3.

[0488] Step 2302c, AMF sends the fourteenth indication information to SMF, and the fourteenth indication information is used to indicate b2.

[0489] Step 2303c, SMF sends the fifteenth indication information to UPF, and the fifteenth indication information is used to indicate b1.

[0490] A fourth optional implementation: the eighth indication information is used to indicate b4.

[0491] Step 2302d, AMF sends the sixteenth indication information to UPF, and the sixteenth indication information is used to indicate b1.

[0492] Step S2304: UPF sends the received or cached downlink data of the UE to the access network device. This step is optional.

[0493] In the above method, the access network device can determine to execute the above method process according to its own cache status and the status of the UE. In one possible scenario, for example, the access network device determines that its own cache is insufficient, for example, the remaining cache space is lower than a first preset value, then sends a first message to the AMF. For another example, the access network device determines that the UE is in eDRX mode, or the UE is in an RRC inactive state, then sends a first message to the AMF. In this scenario, the first message may include an eighth indication information, so that the UPF suspends sending the UE's downlink data to the access network device to reduce the storage load of the access network device.

[0494] In another possible scenario, for example, after the RAN sends the cached downlink data to the UE, the cache space is sufficient. For example, if the remaining cache space is not less than the second preset value, the first information is sent to the AMF, and the first information may include the ninth indication information, so that the UPF resumes sending the downlink data of the UE to the access network device.

[0495] Connection management may include the establishment of a NAS signaling connection between the UE and the AMF and the release of a NAS signaling connection between the UE and the AMF. The NAS signaling connection is used for NAS signaling interaction between the UE and the core network.

[0496] Currently, there are two states of signaling connection between UE and AMF in 5GS: connection management idle state (CM-IDLE) and connection management connected state (CM connected). When the UE is in CM connected, a NAS signaling connection is established between the UE and the corresponding AMF.

[0497] Specifically, the NAS signaling connection includes two connections: 1. The signaling connection between the UE and the access network device (for example, the RRC connection in the 3GPP access mode). 2. The N2 connection between the access network device and the AMF. Exemplarily, when the core network device sends NAS signaling to the UE, the core network device may send the NAS signaling to the access network device through the N2 connection, and the access network device may send the NAS signaling to the corresponding terminal device.

[0498] Among them, after sending NAS signaling, the core network device can start a timer and wait to receive a response message from the terminal device. When the timer times out and still has not received a response message from the terminal device, the core network device responds to the timeout and may initiate signaling retransmission or directly release the connection of the terminal device.

[0499] See also Fig.24 , is a flow chart of PDU session modification (protocol data unit session modification). Fig.24 As shown, the AMF sends an N2 message 1 (for example, a PDU session modification command) to the RAN. In addition, the AMF starts a timer while sending the N2 message 1, and waits for receiving a response message from the UE before the timer times out. Correspondingly, the RAN receives the N2 message 1.

[0500] The RAN encapsulates the PDU session modification command into RRC message 1 and sends it to the corresponding UE. Correspondingly, the UE receives the RRC message 1.

[0501] In response to RRC message 1, the UE sends RRC message 2 to the RAN. RRC message 2 includes PDU session modification command Ack (PDU session modification command confirmation), that is, RRC message 2 is the response information of the UE to the PDU session modification command. Correspondingly, the RAN receives RRC message 2.

[0502] RAN encapsulates PDU session modification command Ack into N2 message 2 and sends it to AMF. Correspondingly, AMF receives N2 message 2.

[0503] Specifically, AMF receives N2 message 2 within the time set by the timer. If the timer times out and N2 message 2 is not received, AMF may release the connection of the UE. In a possible scenario, the UE sends a response message after a long time, but the AMF does not receive a response message from the UE within the set time, and believes that the connection with the UE has been lost, resulting in the AMF's erroneous release.

[0504] In view of this, an embodiment of the present application provides a new data transmission method to reduce the erroneous release of the terminal device by the first network device and improve the data transmission efficiency.

[0505] The data transmission method can be applied to the second network device and the third network device. As mentioned above, the second network device and the third network device can be RAN and AMF respectively. The following is an example in which the execution subject of the method is RAN and AMF.

[0506] See also Fig.25 , Fig.25 The first data transmission method implemented in this application is shown, which can be applied to Figure 2 In the network structure shown in Fig.25 As shown, the method may include the following process:

[0507] Step 2500: The access network device determines that the eDRX cycle is greater than a preset threshold. This step is optional.

[0508] The preset threshold is predefined or configured by a message from a core network device.

[0509] Step 2501: The access network device sends first information to the AMF, and the first information can be used by the AMF to determine the waiting time. Correspondingly, the AMF receives the first information from the access network device.

[0510] Exemplarily, the first information includes but is not limited to one or more of the following: eDRX cycle, paging time window PTW duration, first duration, first indication information; wherein, the first duration is used to indicate the time interval to the next PTW; the first indication information is used to indicate that the terminal device is in an RRC inactive state.

[0511] Optionally, the first information may also include UE information, such as the identifier of the UE, so that when the AMF sends the second information to the UE, it determines the waiting time for the UE according to the first information corresponding to the identifier of the UE, and waits for the response information of the UE within the waiting time. It can be understood that if the access network device configures the same eDRX for different UEs, the first information may not include the UE information. If the first information may not include the UE information, the UE in this application may be any UE under the access network device that sends the first information. If there are multiple UEs under the access network device, the steps shown in the method for data transmission provided in the embodiment of the present application are performed for each UE.

[0512] Step 2502: AMF sends the second information, and the second information is used to send to the terminal device.

[0513] Specifically, the second information may be NAS signaling, which is a message between the UE and the core network device, and the UE is in a CM connected state. Exemplarily, the transmission process of the NAS signaling includes: the AMF sends the NAS signaling to the access network device, and the access network device sends the NAS signaling to the UE.

[0514] Step 2503: AMF waits to receive a response message from the terminal device within a determined waiting time.

[0515] In one practicable manner, when sending the second information, the AMF starts a timer, and before the timer times out, waits to receive a response message from the UE, where the response message may be a response message of the UE to the second information. Specifically, the timing duration of the timer is the duration determined by the AMF according to the first information, that is, the waiting duration.

[0516] The following describes the process of determining the waiting time according to the first information with reference to a specific example.

[0517] Example 1: The first information includes an eDRX cycle;

[0518] In a possible implementation, the AMF may determine the waiting time corresponding to the received first information according to the first corresponding relationship. The first corresponding relationship includes a first corresponding relationship between different first information and waiting times. See Table 1 for a specific example of a first corresponding relationship provided in an embodiment of the present application.

[0519] Table 1

[0520] eDRX cycle Waiting time eDRX 1 L1 eDRX 1 L2 ... ...

[0521] Exemplarily, the waiting time in the first corresponding relationship may be agreed upon by protocol, or may be notified by other network devices, such as SMF, UPF, RAN, or UE.

[0522] Exemplarily, the first corresponding relationship may also be a corresponding relationship between an eDRX cycle and a scaling factor, and the waiting time may be obtained by multiplying the waiting time in the prior art by the scaling factor corresponding to the eDRX cycle.

[0523] As another example, the waiting time in the first corresponding relationship may also be determined according to the eDRX cycle, for example, the eDRX cycle and the waiting time satisfy a functional relationship, for example, the eDRX cycle and the waiting time are in a positive proportional relationship, and the longer the eDRX cycle, the longer the waiting time. For example, the waiting time satisfies the following formula 1:

[0524] Waiting time = (eDRX / eDRX 0)*L; wherein the waiting time corresponding to eDRX 0 is L.

[0525] like Fig.26 As shown, the access network device sends the first information at t1, and the AMF receives the first information at t2. The first information includes eDRX 1, and the AMF determines the waiting time, i.e., L1, according to the first correspondence and eDRX 1. The AMF sends the second information at t3, and the second information is used to send to the UE. The AMF waits to receive the response information from the UE within the time length of L1 from t3.

[0526] For AMF to receive the response information of UE within the waiting time, one implementation method is that AMF starts the timer at t3 when sending the second information, and the set timer duration is L1, and waits to receive the response information from UE before the timer times out. If AMF does not receive the response information of UE within L1, the timer times out; if AMF receives the response information from the UE at t4, and t4 is within the L1 duration, AMF turns off the timer at t4. In the following implementation method, this explanation can still be used, and it will not be repeated below.

[0527] In another possible implementation, the AMF may determine the waiting time according to the eDRX cycle, wherein the waiting time should not be less than the length of at least one eDRX cycle.

[0528] like Fig. 27As shown, the access network device t1 sends the first information, the AMF receives the first information at t2, the AMF sends the second information at t5, and the time interval between t5 and t6 is one eDRX cycle, then the AMF determines that the waiting time should be at least one eDRX cycle, that is, from t5 to t6. For another example, the AMF sends the second information at t7, and the time interval between t7 and t8 is one eDRX cycle, then the AMF determines that the waiting time should be at least from t7 to t8.

[0529] It should be noted that Fig.26 and Fig. 27 This is only an example and does not constitute a limitation on the time when the access network device sends the first information and the time when the AMF receives the first information in the embodiment of the present application. In one implementation, t1 can be equal to t2.

[0530] Example 2: The first information includes the eDRX cycle and the PTW duration;

[0531] In a possible implementation, illustratively, the AMF may determine the time of receiving the first information as the start time of the PTW, and then the AMF may determine the end time of the PTW according to the PTW duration, and determine the end time of the PTW in each eDRX cycle in multiple eDRX cycles according to the eDRX cycle. Correspondingly, the AMF determines the waiting time according to the first information, and the start time of the waiting time is the start time of sending the second information, and the end time should be at least until the end time of the next PTW after sending the second information, that is, the end time of the waiting time can be the end time of the next PTW after sending the second information, or it can be a time after the end time of the next PTW. Fig.28 As shown, the access network device sends the first information at t1, and the AMF receives the first information at t2, where t2 is the start time of the PTW window. If the AMF sends the second information at t9, the AMF can determine the waiting time according to t2, the eDRX cycle, the PTW and t9. For example, the waiting time can be from the start time of t9 to the end time of the next PTW of t9 (for example, t10), and the time between t9 and t10 is the waiting time. Optionally, the waiting time can also be greater than the time (the time between t9 and t10). For example, the waiting time can be from the start time of t9 to a time after t10. The AMF waits to receive the response information from the UE within the waiting time.

[0532] As another example, the AMF may also determine the time of receiving the first information as the end time of the PTW window, and then determine the end time of the PTW in each eDRX cycle in multiple eDRX cycles according to the eDRX cycle. Correspondingly, the waiting time after the AMF sends the second information should be at least the time from sending the second information to the end time of the next PTW. Fig.29 As shown, the access network device sends the first information at t1, and the AMF receives the first information at t2, where t2 is the end time of the PTW. If the AMF sends the second information at t11, the AMF determines the waiting time according to t2, the eDRX cycle, the PTW and t11. The waiting time may be from the start time of t11 to the end time of the next PTW of t11 (e.g., t12), and the time between t11 and 12 is the waiting time. The waiting may also be other time lengths, for example, the waiting time may be from the start time of t11 to a time after t12. The AMF waits to receive the response information from the UE during the waiting time.

[0533] It should be noted that, 1) in Example 2, the first possible implementation in Example 1 above can also be implemented, that is, the waiting time is determined according to the first corresponding relationship and the received eDRX cycle. Or the waiting time is determined by a new corresponding relationship and the first information, such as a second corresponding relationship, the second corresponding relationship includes a corresponding relationship between a combination of different eDRX cycles and different PTW durations and the waiting time. Similar schemes are not repeated in the following examples. 2) Fig.28 and Fig.29 This is only an example and does not constitute a limitation on the time when the access network device sends the first information and the time when the AMF receives the first information in the embodiment of the present application. In one implementation, t1 can be equal to t2.

[0534] Example 3: The first information includes first indication information;

[0535] The first indication information may be used to indicate that the terminal device is in an RRC inactive state, or to indicate that the terminal device is in an eDRX mode, or to indicate that the UE needs a longer time to send response information.

[0536] In this method, AMF can preconfigure two waiting periods, for example, including a first waiting period and a second waiting period, wherein the first waiting period is a relatively short period, and the second waiting period is a relatively long period. If the AMF receives the first indication information, the second waiting period is determined as the period of waiting for receiving the response information of the UE. If the AMF does not receive the first indication information, the first waiting period is determined as the period of waiting for the response information of the UE. Among them, the first waiting period can also be understood as a period defined in other implementations, or it can be a newly defined period in the embodiment of the present application, such as a period agreed in the protocol, or a period determined by the core network device, which is not limited in the embodiment of the present application.

[0537] Example 4: The first information includes a first duration; in a possible implementation manner, the first duration is used to indicate at least one of the following:

[0538] (1) The time interval to the next PTW;

[0539] (2) The time interval to the next paging opportunity PO.

[0540] It should be understood that the first duration here may indicate an accurate time interval value, for example, the PTW length may be at the subframe level, and the time interval value may also be accurate to the subframe level. Alternatively, the time interval indicated by the first duration may also indicate an approximate time interval, for example, the aforementioned PTW length may be at the subframe level, and the time interval value may also be at the second level or the minute level, that is, an approximate time range, which is not limited in the embodiments of the present application.

[0541] In a first practicable manner, the first duration is used to indicate the time interval to the next PTW, that is, the first duration may be the time interval from the time when the access network device sends the first information to the next PTW, such as Fig.30 As shown, the first duration is Fig.30 L, where the start time of L is the time when the access network device sends the first message, and the end time of L is the end time of PTW. The access network device sends the first message at t1, and AMF receives the first message at t2. Assuming that AMF can determine the time t1, for example, AMF determines t1 based on t2 and the transmission delay of the first message (the time difference between t1 and t2). Assuming that AMF sends the second message at t12, AMF determines t1 based on t1, the first duration ( Fig.30 L) in the waiting time is determined, and the waiting time is at least the time elapsed between t12 and the end time of the first time.

[0542] Optionally, the first information may also include an eDRX cycle, and the first duration is still used to indicate the time interval from the end time of the next PTW. The AMF may determine the end time of multiple PTWs according to the eDRX cycle and the first duration, such as Fig.31 As shown, the access network device sends the first information at t1, and the AMF receives the first information at t2. Exemplarily, the AMF determines t1 based on t2 and the transmission delay of the first information (the time difference between t11 and t2). The AMF sends the second information at t13. The AMF can determine the waiting time based on t1, the first time duration and the eDRX cycle. The waiting time should be at least the time elapsed between t13 and the end time of the next PTW after t13.

[0543] It should be understood that Fig.30 and Fig.31 The length of the PTW in is only for illustration, and is used to indicate the time until the end of the next PTW.

[0544] In a second feasible manner, the first duration is used to indicate the time interval to the next paging occasion PO, such as Fig.32 As shown, the first duration is Fig.32 L, where the start time of L is the time when the access network device sends the first message, and the end time of L is the end time of the paging opportunity PO. The access network device sends the first message at t1, and the AMF receives the first message at t2. Exemplarily, the AMF determines t1 based on t2 and the transmission delay of the first message (the time difference between t1 and t2). The AMF sends the second message at t14. Then the AMF determines t1 based on t1, the first duration ( Fig.30 L) in the waiting time is determined, and the waiting time is at least the time elapsed between t14 and the end time of the first time.

[0545] Optionally, the first information may also include an eDRX cycle and a first duration, and the first duration is still used to indicate the time interval from the next paging opportunity PO. Then the AMF may also determine the end time of multiple POs according to the eDRX cycle and the first duration, such as Fig.33 As shown, the access network device sends the first information at t1, and the AMF receives the first information at t2. Exemplarily, the AMF determines t1 based on t2 and the transmission delay of the first information (the time difference between t1 and t2). The AMF sends the second information at t15. The AMF can determine the waiting time based on t1, the first time duration and the eDRX cycle. The waiting time should be at least the time elapsed between t15 and the end time of the next PO after t15.

[0546] In a possible implementation, the first information may include only the following time points:

[0547] (1) The end time of the next PTW;

[0548] (2) The end time of the next paging opportunity PO.

[0549] The AMF determines the waiting time based on the time of sending the second information and the time point information in (1)(2), and the waiting time is at least the time from the AMF sending the second information to (1)(2).

[0550] Fig.34 A complete method for data transmission in an embodiment of the present application is shown, which can be applied to Figure 2 In the system architecture shown in Fig.34 As shown, the method may include the following process:

[0551] Step 3401: The access network device sends an RRC release message to the UE;

[0552] Specifically, the RRC release message includes a suspend configuration and an eDRX cycle. The suspend configuration is used to suspend the RRC connection, so that the UE enters an RRC inactive state. Optionally, the RRC release message may also include a PTW duration. In an achievable manner, the eDRX cycle may also be included in the suspend configuration. The embodiment of the present application does not limit the form of sending data.

[0553] Step 3402: The access network device sends the first information to the AMF. Correspondingly, the AMF receives the first information.

[0554] The first information may be the first information in the above examples.

[0555] Step 3403: AMF sends the second information (such as Fig.34 The access network device receives the second message N2 in the N2 message 1), and starts a timer, and waits for receiving a response message from the UE before the timer times out. Correspondingly, the access network device receives the second message.

[0556] The second information is used to send to the UE. The AMF determines the waiting time according to the first information, where the waiting time can be reflected as the timeout value of the timer, that is, the setting time of the timer is the waiting time.

[0557] Step 3404: The access network device pages the UE to perform RRC connection recovery with the UE.

[0558] Step 3405: ​​The access network device sends the second information (for example, Fig.34 The second information is sent to the UE in the form of RRC message 1 in the RRC message 1. Correspondingly, the UE receives the second information.

[0559] Step 3406: The UE sends the response information (eg Fig.34 The RRC message 2) in the access network device is sent to the access network device. Correspondingly, the access network device receives the response information.

[0560] Step 3407: The access network device sends the response information (eg Fig.34 N2 message 2) is sent to AMF.

[0561] Step 3408: AMF receives the response information.

[0562] A possible scenario is that the AMF receives the response information within the timing of the timer (i.e. before the timeout).

[0563] Another possible scenario is that the timer times out and the AMF has not received the response information from the UE. In this case, the AMF responds to the timeout and the core network device may trigger a retransmission. If the response information times out after multiple retransmissions, it can be determined that the UE is unreachable.

[0564] Through the above manner, the waiting time in the embodiment of the present application is longer than the existing time, or is more adapted to the actual response time of the UE, and can also be dynamically configurable to avoid the core network device from misoperating the UE. For example, the problem of misrelease caused by the UE not replying to the response information in time in the eDRX mode can be avoided.

[0565] See also Fig.35 , Fig.35 Another data transmission method implemented in the present application is shown, which can be applied to Figure 2 In the network structure shown in Fig.35 As shown, the method may include the following process:

[0566] Step 3501: The access network device sends first information to the AMF, and the first information can be used by the AMF to determine the time to send the second information. Correspondingly, the AMF receives the first information.

[0567] Step 3502: AMF sends the second information based on the first information.

[0568] In the above data transmission method, the AMF determines the waiting time according to the first information, that is, the waiting time after the AMF sends the second information. Fig.35 In the data transmission method shown, the second information may not be sent first, that is, the second information may be sent with a delay so that the time of sending the second information is closer to the time when the UE can be awakened.

[0569] The process of sending the second information according to the first information is introduced below with reference to a specific example.

[0570] Example 1: The first information includes an eDRX cycle.

[0571] The eDRX cycle may also be a wake-up cycle of the UE or a discontinuous reception DRX cycle or a sleep cycle of the UE; the following description is given by taking the example that the first information includes the eDRX cycle.

[0572] In a possible implementation, the AMF may determine a third time based on the eDRX cycle and the time of receiving the first information, and the AMF sends the second information to the access network device before the third time, wherein the third time is the eDRX cycle boundary or the eDRX cycle start time after the AMF determines that there is the second information.

[0573] like Fig.36As shown, the access network device sends the first information at t1, and the AMF receives the first information at t2. If the AMF determines that there is the second information at t3, the AMF determines the third time according to t2 and the eDRX cycle, that is, t5, and the AMF sends the second information to the access network device at t4 before t5; if the AMF receives and determines that there is the second information at t6, the AMF determines the third time according to t2 and the eDRX cycle, that is, t8, and the UPF sends the second information to the access network device at t7 before t8; if the AMF determines that there is the second information at t9, the AMF determines the third time according to t2 and the eDRX cycle, that is, t11, and the UPF sends the second information to the access network device at t10 before t11.

[0574] Exemplarily, t5 can be understood as the latest sending time, the interval between t5 and t4 can be understood as the preset duration, and AMF can send the second information to the access network device at the preset duration before t5, that is, t4. Optionally, AMF can also send the second information to the access network device at any time between t4 and t5, and the repetitive parts will not be repeated below.

[0575] It should be noted that Fig.36 This is only an example and does not constitute a limitation on the time when the access network device sends the first information and the time when the AMF receives the first information in the embodiment of the present application. In one implementation, t1 can be equal to t2.

[0576] In a possible implementation, the AMF may determine the fourth time according to the eDRX cycle and the time of receiving the first information, and the AMF sends the second information to the access network device at the fourth time, wherein the fourth time is the time before the eDRX cycle boundary or the eDRX cycle start time (just before) after the AMF determines that there is the second information. Fig.37 As shown, the access network device sends the first information at t1, and the AMF receives the first information at t2. If the AMF determines at t3 that there is the second information, the AMF determines the fourth time according to t2 and the eDRX cycle, that is, t4, and the AMF sends the second information to the access network device at t4. For example, the AMF determines the fourth time according to t2, eDRX and the time advance for sending the second information. If the AMF determines at t6 that there is the second information, the AMF determines the fourth time according to t2 and the eDRX cycle, that is, t7, and the AMF sends the second information to the access network device at t7; if the AMF determines at t9 that there is the second information, the AMF determines the fourth time according to t2 and the eDRX cycle, that is, t10, and the AMF sends the second information to the access network device at t10.

[0577] It should be noted that Fig.37This is only an example and does not constitute a limitation on the time when the access network device sends the first information and the time when the AMF receives the first information in the embodiment of the present application. In one implementation, t1 can be equal to t2.

[0578] Example 2: The first information may include an eDRX cycle and a PTW duration;

[0579] In a possible implementation, the AMF determines the time when the first information is received as the start time of the eDRX cycle and the PTW, and the AMF may determine the third time according to the eDRX cycle, the PTW duration, and the time when the first information is received, and the AMF sends the second information to the access network device before the third time. For example, the AMF sends the second information to the access network device within the PTW before the third time, wherein the third time is the end time of the PTW after the AMF determines that there is the second information. Fig.38 As shown, the access network device sends the first information at t1, and the AMF receives the first information at t2. If the AMF determines at t9 that there is the second information, the AMF determines the third time, i.e., t11, according to t2, the eDRX cycle and the PTW, and the AMF sends the second information to the access network device at t10 before t11.

[0580] It should be noted that Fig.38 This is only an example and does not constitute a limitation on the time when the access network device sends the first information and the time when the AMF receives the first information in the embodiment of the present application. In one implementation, t1 can be equal to t2.

[0581] In a possible implementation, the AMF determines the time when the first information is received as the start time of the eDRX cycle and the PTW, and the AMF may determine the fourth time according to the eDRX cycle, the PTW duration, and the time when the first information is received, and the AMF sends the second information to the access network device at the fourth time, wherein the fourth time is the time before the PTW ends (just before), for example, the fourth time is the time within the PTW. Fig.39 As shown, the access network device sends the first information at t1, and the AMF receives the first information at t2. If the AMF determines at t9 that there is second information, the AMF determines the fourth time, that is, t10, according to t2, the eDRX cycle and the PTW, and the AMF sends the second information to the access network device at t10.

[0582] It should be noted that Fig.39 This is only an example and does not constitute a limitation on the time when the access network device sends the first information and the time when the AMF receives the first information in the embodiment of the present application. In one implementation, t1 can be equal to t2.

[0583] In a possible implementation, the AMF determines the time when the first information is received as the start time of the eDRX cycle and the end time of the PTW, and the AMF may determine the third time according to the eDRX cycle, the PTW duration, and the time when the first information is received, and the AMF sends the second information to the access network device before the third time. For example, the AMF sends the second information to the access network device within the PTW before the third time, wherein the third time is the end time of the PTW. Fig.40 As shown, the access network device sends the first information at t1, and the AMF receives the first information at t2. If the AMF determines at t9 that there is the second information, the AMF determines the third time, i.e., t11, according to t2, the eDRX cycle and the PTW, and the AMF sends the second information to the access network device at t10 before t11.

[0584] It should be noted that Fig.40 This is only an example and does not constitute a limitation on the time when the access network device sends the first information and the time when the AMF receives the first information in the embodiment of the present application. In one implementation, t1 can be equal to t2.

[0585] In a possible implementation, the AMF determines the time when the first information is received as the start time of the eDRX cycle and the end time of the PTW, and the AMF can determine the fourth time according to the eDRX cycle, the PTW duration, and the time when the first information is received, and the AMF sends the second information to the access network device at the fourth time, wherein the fourth time is the time before the end of the PTW, for example, the fourth time is within the PTW. Fig.41 As shown, the access network device sends the first information at 11, and the AMF receives the first information at t2. If the AMF determines at t9 that there is second information, the AMF determines the fourth time, that is, t10, according to t2, the eDRX cycle and the PTW, and the AMF sends the second information to the access network device at t10.

[0586] It should be noted that Fig.41 This is only an example and does not constitute a limitation on the time when the access network device sends the first information and the time when the AMF receives the first information in the embodiment of the present application. In one implementation, t1 can be equal to t2.

[0587] In a possible implementation, the AMF determines the time when the first information is received as the start time of the eDRX cycle and the end time of the PTW, and the AMF can determine the fourth time according to the eDRX cycle, the PTW duration, and the time when the first information is received, and the AMF sends the second information to the access network device at the fourth time, wherein the fourth time is the time before the PTW. Fig.42As shown, the access network device sends the first information at t1, and the AMF receives the first information at t2. If the AMF determines at t9 that there is second information, the AMF determines the fourth time, that is, t10, according to t2, the eDRX cycle and the PTW, and the AMF sends the second information to the access network device at t10.

[0588] It should be noted that Fig.42 This is only an example and does not constitute a limitation on the time when the access network device sends the first information and the time when the AMF receives the first information in the embodiment of the present application. In one implementation, t1 can be equal to t2.

[0589] In the present application, the eDRX cycle may be a paging occasion (PO) cycle, such as Fig.11a Alternatively, the eDRX cycle is a paging time window (PTW) cycle, wherein the PTW includes one or more POs, such as Fig.11b shown.

[0590] Example 3: The first information may include an eDRX cycle and a first duration;

[0591] In a possible implementation manner, the first duration is used to indicate at least one of the following:

[0592] (1) the time interval between the time when the access network device sends the first information and the next eDRX cycle boundary;

[0593] (2) The time interval to the next PTW;

[0594] (3) The time interval to the next paging opportunity PO.

[0595] The AMF determines a third time according to the first duration and the eDRX cycle, wherein the third time is the eDRX cycle boundary after the AMF determines that the second information is available. Fig.43 As shown, the access network device sends the first information at t1, the AMF receives the first information at t2, the AMF determines that there is the second information at t9, and the AMF determines t1 according to t2 and the transmission delay of the first information (the time difference between t1 and t2), and then determines the eDRX cycle boundary according to the first duration L, and determines the third time t11 according to the determined eDRX cycle boundary and the eDRX cycle. Exemplarily, if t1 is equal to t2, the AMF directly determines the third time t11 according to t1, L and the eDRX cycle. The AMF sends the second information to the access network device at t10 before the third time.

[0596] In a possible implementation manner, the first duration is used to indicate the time interval between the time when the access network device sends the first information and the next eDRX cycle boundary. The AMF determines the fourth time according to the first duration and the eDRX cycle, wherein the fourth time is the time before the eDRX cycle boundary after the AMF determines that there is the second information. Fig.44 As shown, the access network device sends the first information at t1, the AMF receives the first information at t2, the AMF determines that there is the second information at t9, the AMF determines t1 based on t2 and the transmission delay of the first information, and then determines the eDRX cycle boundary based on t1 and the first duration L, and determines the fourth time, i.e., t10, based on the determined eDRX cycle boundary and the eDRX cycle. Exemplarily, if t1 is equal to t2, the AMF directly determines the fourth time t10 based on 11, L and the eDRX cycle. The AMF sends the second information to the access network device at the fourth time t10.

[0597] The above mainly introduces the solution provided by the present application from the perspective of the interaction between various network elements. It can be understood that in order to realize the above functions, each of the above network elements includes a hardware structure and / or software module corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of each example described in the embodiments disclosed in this document, the present invention can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0598] like Fig.45 As shown, it is a possible exemplary block diagram of the data transmission device involved in the present application. The device 4500 can exist in the form of software or hardware. The device 4500 may include: a processing unit 4502 and a communication unit 4503. As an implementation method, the communication unit 4503 may include a receiving unit and a sending unit. The processing unit 4502 is used to control and manage the actions of the device 4500. The communication unit 4503 is used to support the communication between the device 4500 and other network entities. The device 4500 may also include a storage unit 4501 for storing program codes and data of the device 4500.

[0599] Among them, the processing unit 4502 can be a processor or a controller, for example, it can be a general-purpose central processing unit (CPU), a general-purpose processor, a digital signal processing (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. It can implement or execute various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of this application. The processor can also be a combination that implements a computing function, for example, including a combination of one or more microprocessors, a combination of DSP and microprocessors, and the like. The storage unit 4501 can be a memory. The communication unit 4503 is an interface circuit of the device for receiving signals from other devices. For example, when the device is implemented in the form of a chip, the communication unit 4503 is an interface circuit of the chip for receiving signals from other chips or devices, or an interface circuit of the chip for sending signals to other chips or devices.

[0600] The device 4500 may be a network device (such as an access and mobility management network element, a session management network element, a user plane network element or an access network device) in any of the above embodiments, and may also be a chip for a network device. For example, when the device 4500 is a network device, the processing unit 4502 may be, for example, a processor, and the communication unit 4503 may be, for example, a transceiver. Optionally, the transceiver may include a radio frequency circuit, and the storage unit may be, for example, a memory. For example, when the device 4500 is a chip for a network device, the processing unit 4502 may be, for example, a processor, and the communication unit 4503 may be, for example, an input / output interface, a pin or a circuit, etc. The processing unit 4502 may execute computer-executable instructions stored in the storage unit. Optionally, the storage unit is a storage unit in the chip, such as a register, a cache, etc. The storage unit may also be a storage unit in the network device located outside the chip, such as a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM), etc.

[0601] In the first embodiment, the device 4500 is the first network device (user plane network element) in the above example, and the communication unit 4503 of the first network device includes a sending unit and a receiving unit. The receiving unit is used to receive downlink data, and the downlink data is used to send to the terminal device; receive first information from the second network device, and the first information is used to determine the time to send the downlink data to the second network device; the processing unit 4502 is used to send the downlink data to the second network device according to the first information.

[0602] In a possible implementation method, the first information includes an extended discontinuous reception eDRX cycle; or, the first information includes the eDRX cycle and the paging time window PTW duration; or, the first information includes the eDRX cycle and the first duration; or, the first information includes the eDRX cycle, the PTW duration and the first duration; the first information includes the first duration; or, the first information includes the eighth indication information; or, the first information includes the eighth indication information and the second duration; or, the first information includes the ninth indication information; wherein the first duration is used to indicate the time interval to the next PTW, or to indicate the time interval to the next paging opportunity PO, the eighth indication information is used to indicate the suspension of sending downlink data to the terminal device, the second duration is used to indicate the duration of suspending the sending of the downlink data to the terminal device, and the ninth indication information is used to indicate the resumption of sending the downlink data to the terminal device.

[0603] In a possible implementation method, the processing unit 4502 is specifically used to determine the latest sending time of sending the downlink data according to the first information; the sending unit is specifically used to send the downlink data to the second network device within a first preset time before the latest sending time.

[0604] In a possible implementation method, the latest sending time is the wake-up time of the terminal device after receiving the downlink data.

[0605] In a possible implementation method, the sending unit is specifically used to send second indication information to the second network device or the third network device; wherein the second indication information is used to indicate the presence of the downlink data.

[0606] In a possible implementation method, the first network device is a user plane network element UPF, the second network device is an access network device, and the third network device is an access network device or an access and mobility management network element AMF.

[0607] In the second embodiment, the device 4500 is the second network device (access network device) in the above example, and the communication unit 4503 of the second network device includes a sending unit and a receiving unit. The processing unit 4502 is used to determine the first information, the first information is used to determine the sending time of the downlink data, and the downlink data is used to send to the terminal device; the sending unit is used to send the first information to the first network device.

[0608] In a possible implementation method, the first information includes: the first information includes an extended discontinuous reception eDRX cycle; or, the first information includes the eDRX cycle and the paging time window PTW duration; or, the first information includes the eDRX cycle and the first duration; or, the first information includes the eDRX cycle, the PTW duration and the first duration; the first information includes the first duration; or, the first information includes the eighth indication information; or, the first information includes the eighth indication information and the second duration; or, the first information includes the ninth indication information; wherein the first duration is used to indicate the time interval to the next PTW, or to indicate the time interval to the next paging opportunity PO, the eighth indication information is used to indicate the suspension of sending downlink data to the terminal device, the second duration is used to indicate the duration of suspending the sending of the downlink data to the terminal device, and the ninth indication information is used to indicate the resumption of sending the downlink data to the terminal device.

[0609] In a possible implementation method, the receiving unit is specifically configured to receive second indication information; wherein the second indication information is used to indicate the presence of the downlink data.

[0610] In a possible implementation method, the processing unit 4502 is further configured to determine that the extended discontinuous reception eDRX cycle is not less than a preset threshold.

[0611] In a possible implementation method, the first network device is a user plane network element UPF or an access and mobility management network element AMF.

[0612] In the third embodiment, the device 4500 is the third network device (access and mobility management network element) in the above example, and the communication unit 4503 of the access network device includes a sending unit and a receiving unit. The receiving unit is used to receive the first information from the second network device; the first information is used to determine the sending time of the downlink data, and the downlink data is used to send to the terminal device; the sending unit is used to send the first information to the first network device.

[0613] In a possible implementation method, the first information includes: the first information includes an extended discontinuous reception eDRX cycle; or, the first information includes the eDRX cycle and the paging time window PTW duration; or, the first information includes the eDRX cycle and the first duration; or, the first information includes the eDRX cycle, the PTW duration and the first duration; wherein the first duration is used to indicate the time interval to the next PTW, or, to indicate the time interval to the next paging opportunity PO.

[0614] In a possible implementation method, the receiving unit is specifically configured to receive second indication information from the first network device; wherein the second indication information is used to indicate that the first network device has the downlink data.

[0615] In a possible implementation method, the first network device is a user plane network element UPF, and the second network device is an access network device.

[0616] In the fourth embodiment, the device 4500 is the first network device (user plane network element) in the above example, and the communication unit 4503 of the first network device includes a sending unit and a receiving unit. The receiving unit is used to receive second information from the second network device, and the second information is used to indicate that the terminal device is reachable; the processing unit 4502 is used to send the downlink data of the terminal device to the second network device according to the second information.

[0617] In a possible implementation method, the second information is used to indicate that the terminal device requests to enter a radio resource control (RRC) connection state, or the second information is used to indicate that the terminal device is in an RRC connection state.

[0618] In a possible implementation method, the processing unit is used to determine whether the downlink data of the terminal device is cached.

[0619] In a possible implementation method, the sending unit is specifically used to send fourth indication information to the second network device or the third network device; wherein the fourth indication information is used to indicate whether downlink data of the terminal device is cached.

[0620] In a possible implementation method, the second network device is an access network device, and the third network device is an access network device or an access and mobility management network element AMF.

[0621] In the fifth embodiment, the device 4500 is the second network device (access network device) in the above example, and the communication unit 4503 of the second network device includes a sending unit and a receiving unit. The processing unit 4502 is used to determine the second information, and the second information is used to indicate that the terminal device is reachable; the sending unit is used to send the second information to the first network device.

[0622] In a possible implementation method, the second information is used to indicate that the terminal device requests to enter a radio resource control (RRC) connection state, or the second information is used to indicate that the terminal device is in an RRC connection state.

[0623] In a possible implementation method, the receiving unit is specifically used to receive fourth indication information from the first network device; wherein the fourth indication information is used to indicate that downlink data of the terminal device is cached.

[0624] In a possible implementation method, the sending unit is also used to send sixth indication information to the third network device, where the sixth indication information is used to indicate the load status of the second network device, or the sixth indication information is used to indicate that the second network device supports the ability to send first information to the first network device.

[0625] In a possible implementation method, the first network device is a user plane network element UPF; the second network device is an access network device, and the third network device is an access and mobility management network element AMF.

[0626] In the sixth embodiment, the device 4500 is the third network device (access and mobility management network element) in the above example, and the communication unit 4503 of the access network device includes a sending unit and a receiving unit. The processing unit 4502 is used to determine the second information, and the second information is used to indicate that the terminal device is reachable; the sending unit is used to send the second information to the first network device.

[0627] In a possible implementation method, the second information is used to indicate that the terminal device requests to enter a radio resource control (RRC) connection state, or the second information is used to indicate that the terminal device is in an RRC connection state.

[0628] In a possible implementation method, the receiving unit is specifically used to receive fourth indication information from the first network device; wherein the fourth indication information is used to indicate that downlink data of the terminal device is cached.

[0629] In a possible implementation method, the receiving unit is further used to receive sixth indication information, where the sixth indication information is used to indicate a load status of the second network device, or the sixth indication information is used to indicate that the second network device supports the ability to send first information to the first network device.

[0630] In a possible implementation method, the first network device is a user plane network element UPF; the second network device is an access network device, and the third network device is an access and mobility management network element AMF.

[0631] In the sixth embodiment, the device 4500 is the third network device (access and mobility management network element) in the above example, and the communication unit 4503 of the access network device includes a sending unit and a receiving unit. The receiving unit is used to receive the first information from the second network device; the sending unit is used to send the second information, and the second information is used to send to the terminal device; the processing unit 4502 is used to wait for receiving the response information from the terminal device through the receiving unit within the waiting time after the sending unit sends the second information;

[0632] The first information includes one or more of the following: an extended discontinuous reception eDRX cycle, a paging time window PTW duration, a first duration, and a first indication information; wherein the first duration is used to indicate the time interval to the next PTW, or to indicate the time interval to the next paging opportunity PO; the first indication information is used to indicate that the terminal device is in an RRC inactive state.

[0633] In a possible implementation method, the terminal device is in a connection management connection state CM connected; and the second information is NAS signaling.

[0634] In the seventh embodiment, the device 4500 is the second network device (access network device) in the above example, and the communication unit 4503 of the second network device includes a sending unit and a receiving unit. The processing unit 4502 is used to determine the first information; wherein the first information includes one or more of the following: an extended discontinuous reception eDRX cycle, a paging time window PTW duration, a first duration, and a first indication information; wherein the first duration is used to indicate the time interval from the next PTW, or, to indicate the time interval from the next paging opportunity PO; the first indication information is used to indicate that the terminal device is in an RRC inactive state; the sending unit is used to send the first information to the third network device.

[0635] In a possible implementation method, the first information is used to determine the response time of the terminal device to the second information, and the second information is used to send to the terminal device.

[0636] In a possible implementation method, before the sending unit sends the first information to the first network device, the processing unit is further configured to determine that an extended discontinuous reception eDRX cycle is not less than a preset threshold.

[0637] See also Fig.46 As shown, it is a schematic diagram of a device provided by the present application, and the device may be a network device in the above-mentioned embodiments (such as the access and mobility management network element, session management network element, user plane network element or access network device in the above-mentioned examples). The device 4600 includes: a processor 4602 and a communication interface 4603. Optionally, the device 4600 may also include a memory 4601 and / or a communication line 4604. Among them, the communication interface 4603, the processor 4602 and the memory 4601 may be interconnected via a communication line 4604; the communication line 4604 may be a peripheral component interconnect standard (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The communication line 4604 may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig.46 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0638] Processor 4602 can be a CPU, a microprocessor, an ASIC, or one or more integrated circuits for controlling the execution of the program of the present application.

[0639] The communication interface 4603 uses any transceiver-like device to communicate with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), wired access networks, etc.

[0640] The memory 4601 may be a ROM or other type of static storage device that can store static information and instructions, a RAM or other type of dynamic storage device that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory may exist independently and be connected to the processor via a communication line 4604. The memory may also be integrated with the processor.

[0641] The memory 4601 is used to store computer-executable instructions for executing the solution of the present application, and the execution is controlled by the processor 4602. The processor 4602 is used to execute the computer-executable instructions stored in the memory 4601, thereby realizing the session processing method provided in the above embodiment of the present application.

[0642] Optionally, the computer-executable instructions in the embodiments of the present application may also be referred to as application code, which is not specifically limited in the embodiments of the present application.

[0643] The program product may use any combination of one or more readable media. The readable medium may be a readable signal medium or a readable medium. The readable medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of readable media (a non-exhaustive list) include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical device, a magnetic device, or any suitable combination of the above.

[0644] The program product for configuring parameters according to an embodiment of the present invention may be in a portable compact disk read-only device (CD-ROM) and include program code, and may be run on a server device. However, the program product of the present invention is not limited thereto, and in this document, the readable medium may be any tangible medium containing or having a program, which may be used by or in combination with information transmission, an apparatus or a device.

[0645] The readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, wherein the readable program code is carried. Such propagated data signals may take a variety of forms, including, but not limited to, electromagnetic signals, optical signals, or any suitable combination of the above. The readable signal medium may also be any readable medium other than a readable medium, which may transmit, propagate, or transfer a program for use by or in conjunction with a periodic network action system, device, or device.

[0646] The program code embodied on the readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0647] Program code for performing the operations of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device.

[0648] The embodiment of the present application also provides a computing device readable medium for the information synchronization method, that is, the content is not lost after power failure. The medium contains a software program, including program code, and when the program code is run on the computing device, the software program can implement any of the above information synchronization solutions of the embodiment of the present application when it is read and executed by one or more processors.

[0649] The present application is described above with reference to the block diagrams and / or flow charts showing the methods, devices (systems) and / or computer program products according to the embodiments of the present application. It should be understood that a block of the block diagram and / or flow chart diagram and a combination of blocks of the block diagram and / or flow chart diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer and / or other programmable data processing device to produce a machine, so that the instructions executed by the computer processor and / or other programmable data processing device create a method for implementing the functions / actions specified in the block diagram and / or flow chart block.

[0650] Accordingly, the present application may also be implemented in hardware and / or software (including firmware, resident software, microcode, etc.). Furthermore, the present application may take the form of a computer program product on a computer-usable or computer-readable medium, which has a computer-usable or computer-readable program code implemented in the medium, for use by or in conjunction with an instruction execution system. In the context of the present application, a computer-usable or computer-readable medium may be any medium that may contain, carry, communicate, transmit, or convey a program for use by or in conjunction with an instruction execution system, device, or apparatus.

[0651] Although the present application has been described in conjunction with specific features and embodiments thereof, it is obvious that various modifications and combinations may be made thereto without departing from the spirit and scope of the present application. Accordingly, this specification and the drawings are merely exemplary illustrations of the present application as defined by the appended claims, and are deemed to have covered any and all modifications, variations, combinations or equivalents within the scope of the present application. Obviously, a person skilled in the art may make various modifications and variations to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for data transmission, characterized in that: The method is applicable to an access network device or a chip of the access network device, and the method includes: Determine first information; the first information is used to trigger the access and mobility management function AMF to send first indication information to the network device, the first indication information is used to instruct the network device to cache the downlink data when receiving the downlink data of the terminal device; the first information is also used to determine the deadline for the network device to cache the downlink data; Sending the first information to the AMF; The first information includes an extended discontinuous reception eDRX cycle; or the first information includes an eDRX cycle and a paging time window PTW duration.

2. The method according to claim 1, characterized in that The first information also includes a first duration; wherein the first duration is used to indicate a time interval to a next PTW, or to indicate a time interval to a next paging occasion PO.

3. The method according to claim 1 or 2, characterized in that The method further comprises: Receive second indication information from the AMF, wherein the second indication information is used to indicate that there is downlink data of the terminal device.

4. The method according to claim 1 or 2, characterized in that: The network device includes a user plane network element UPF or a task management function network element SMF.

5. A method for data transmission, characterized in that: The method is applicable to an access and mobility management function AMF or a chip of the AMF, and the method includes: receiving first information from an access network device; the first information is used to trigger the AMF to send first indication information to the network device; the first information is also used to determine a deadline for the network device to cache downlink data; Sending first indication information to the network device, wherein the first indication information instructs the network device to cache the downlink data when receiving the downlink data from the terminal device.

6. The method according to claim 5, characterized in that The method further comprises: Receive second indication information from the network device, where the second indication information indicates downlink data from the terminal device.

7. The method according to claim 5 or 6, characterized in that The first information includes an extended discontinuous reception eDRX cycle; or, the first information includes an eDRX cycle and a paging time window PTW duration.

8. The method according to claim 5 or 6, characterized in that The method further comprises: Determine that the extended discontinuous reception eDRX cycle is not less than a preset threshold.

9. The method according to claim 5 or 6, characterized in that The network device includes a user plane network element UPF or a task management function network element SMF.

10. A data transmission device, characterized in that: The device comprises: a processing unit, configured to determine first information, wherein the first information is used to trigger an access and mobility management function AMF to send first indication information to a network device, wherein the first indication information is used to instruct the network device to cache the downlink data when receiving the downlink data of a terminal device; the first information is also used to determine a deadline for the network device to cache the downlink data; A communication unit, configured to send the first information to the AMF; The first information includes an extended discontinuous reception eDRX cycle; or the first information includes an eDRX cycle and a paging time window PTW duration.

11. The device according to claim 10, characterized in that The first information also includes a first duration; wherein the first duration is used to indicate a time interval to a next PTW, or to indicate a time interval to a next paging occasion PO.

12. The device according to claim 10 or 11, characterized in that The communication unit is also used to: receive second indication information from the AMF, wherein the second indication information is used to indicate that there is downlink data of the terminal device.

13. The device according to claim 10 or 11, characterized in that The network device includes a user plane network element UPF or a task management function network element SMF.

14. A data transmission device, characterized in that: The device comprises: A communication unit, configured to receive first information from an access network device; the first information is used to trigger the apparatus to send first indication information to the network device; the first information is also used to determine a deadline for the network device to cache downlink data; The communication unit is also used to send first indication information to the network device, wherein the first indication information instructs the network device to cache the downlink data when receiving the downlink data from the terminal device.

15. The device according to claim 14, characterized in that The communication unit is further used to: receive second indication information from the network device, where the second indication information indicates downlink data from the terminal device.

16. The device according to claim 14 or 15, characterized in that The first information includes an extended discontinuous reception eDRX cycle; or, the first information includes an eDRX cycle and a paging time window PTW duration.

17. The device according to claim 14 or 15, characterized in that The device also includes a determining unit; The determining unit is used to determine that the extended discontinuous reception eDRX cycle is not less than a preset threshold.

18. The device according to claim 14 or 15, characterized in that The network device includes a user plane network element UPF or a task management function network element SMF.

19. A data transmission device, characterized in that: The device comprises a processor and a memory, wherein the processor is configured to execute instructions stored in the memory, and when the instructions are executed, the device executes the method according to any one of claims 1 to 4, or the method according to any one of claims 5 to 9.

20. A computer-readable storage medium, characterized in that: The method comprises instructions which, when executed, implement the method according to any one of claims 1 to 9.

21. A computer program product, characterized in that The method comprises computer instructions, which, when executed, enable the method according to any one of claims 1 to 4 to be implemented, or enable the method according to any one of claims 5 to 9 to be implemented.

22. A chip, comprising a processor, configured to call a computer program or a computer instruction in a memory so that the method according to any one of claims 1 to 4 is implemented, or the method according to any one of claims 5 to 9 is implemented.

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