Downlink transmission method and communication device

Abstract

This application provides a downlink transmission method and a communication device. A session management network element obtains a time period, i.e., a first delay, between an expected time point at which a downlink service packet arrives at an access network element and an estimated time point at which the downlink service packet arrives at the access network element. The expected time point at which the downlink service packet arrives at the access network element is within a first scheduling window, and a next scheduling window adjacent to the first scheduling window is a downlink scheduling window. The session management network element then transmits time adjustment information related to the first delay to a user plane network element or an application network element. The time adjustment information is used by the user plane network element to determine a first time point at which the downlink service packet will be transmitted, or by an application server to determine a second time point at which the downlink service packet will be transmitted, and the time point at which the downlink service packet transmitted by the user plane network element at the first time point or the application server at the second time point arrives at the access network element is within the first scheduling window. This solution can reduce the scheduling delay on the access network element side.

Description

[Technical field]

[0002] The present application relates to the field of communications, and more particularly, to a downlink transmission method and a communication device. [Background technology]

[0003] In a communication system, a scheduling delay may be introduced by a downlink service packet on the access network element side, taking into account the particularity of the scheduling of the access network element, for example, the uplink-downlink configuration and the scheduling protection window between slots. For example, if the time when the downlink service packet arrives at the access network element is within the scheduling window of the access network element, the downlink service packet can be scheduled only when at least the closest downlink scheduling window arrives. If the closest scheduling window is not the downlink scheduling window but the uplink scheduling window, the scheduling waiting delay introduced on the access network element side is greater than the length of at least one scheduling window. As another example, if the time when the downlink service packet arrives at the access network element is within the processing window of the access network element, the downlink service packet can be scheduled only when at least the next back downlink scheduling window arrives. However, the scheduling waiting delay introduced on the access network element side may not guarantee the end-to-end delay of the downlink service packet. Summary of the Invention [Means for solving the problem]

[0004] The present application provides a downlink transmission method and a communication device to help reduce the scheduling delay on the access network element side and guarantee the end-to-end delay requirement of downlink service packets.

[0005] According to a first aspect, a downlink transmission method is provided, the method includes the steps of: a session management network element obtains a first delay, the first delay being a period between an expected time when a downlink service packet arrives at an access network element and an estimated time when the downlink service packet arrives at the access network element, the expected time when the downlink service packet arrives at the access network element is within a first scheduling window, and a next scheduling window adjacent to the first scheduling window is a downlink scheduling window. The session management network element transmits time adjustment information related to the first delay to the first network element, the first network element being a user plane network element or an application network element, the time adjustment information is for determining a first time when the user plane network element transmits the downlink service packet, or is used by an application server to determine a second time when the downlink service packet is transmitted, and a third time when the downlink service packet transmitted by the user plane network element at the first time or transmitted by the application server at the second time arrives at the access network element is within the first scheduling window.

[0006] According to the downlink transmission method provided in the present application, the application server or user plane network element can adjust the time point of sending the downlink service packet based on the time adjustment information provided by the session management network element, so that when the downlink service packet is sent at the adjusted sending time point, the time point of the downlink service packet arriving at the access network element can be within a first scheduling window of the access network element, and the downlink service packet can be scheduled within a second downlink scheduling window, which is the next scheduling window adjacent to the first scheduling window. This helps to reduce the scheduling waiting delay of scheduling the downlink service by the access network element, and also helps to guarantee the end-to-end delay of the downlink service packet. In addition, the application server or user plane network element usually receives multiple downlink service packets for multiple access network elements. According to the method, in order to make appropriate use of resources, mitigate and avoid processing contention between downlink service packets sent to different access network element nodes, improve the processing efficiency of downlink service packets in an application server or user plane network element, and help guarantee the end-to-end delay requirements of a downlink service packet and another downlink service packet, an application server or a user plane network element can buffer a downlink service packet while preferentially processing another downlink service packet.

[0007] Referring to the first aspect, in some implementations of the first aspect, the session management network element obtaining the first delay includes the session management network element obtaining configuration information of radio resources of the access network element and an estimated time when the downlink service packet arrives at the access network element. The session management network element determines the first delay based on the configuration information of the radio resources and the estimated time when the downlink service packet arrives at the access network element.

[0008] Optionally, the access network element can report the radio resource configuration information and the corresponding cell identifier (ID) to the mobility management network element (e.g., access and mobility management function (AMF)) in the NG Setup process, and the session management network element can obtain the radio resource configuration information and the cell ID from the mobility management network element. The NG Setup process is sometimes called the N2 Setup process, and the interface between the access network element and the mobility management network element is called the NG interface.

[0009] Alternatively, in the registration process of the terminal device, when the access network element forwards the registration request to the mobility management network element, the registration request may carry the cell ID and the configuration information of the radio resource, or may carry the cell ID, the terminal device ID, and the configuration information of the radio resource. Then, the session management network element can obtain the configuration information of the radio resource from the mobility management network element.

[0010] Alternatively, at the time of session setup, the access network element may send the cell ID and corresponding configuration information of radio resources, or may send the cell ID, the terminal device ID, and corresponding configuration information of radio resources to the session management network element in an N2 message.

[0011] Alternatively, the access network element may provide the configuration information of the radio resources corresponding to the cell to a network data analytics function (NWDAF) network element, and the session management network element may obtain the configuration information of the radio resources and the corresponding cell ID from the NWDAF.

[0012] Referring to the first aspect, in some implementations of the first aspect, determining the first delay based on the configuration information of the radio resource and the estimated time when the downlink service packet arrives at the access network element includes determining an estimated second downlink scheduling window for the access network element to schedule the downlink service packet based on the configuration information of the radio resource and the estimated time when the downlink service packet arrives at the access network element. The session management network element determines a boundary of a third scheduling window based on the configuration information of the radio resource and the second downlink scheduling window, the third scheduling window being a scheduling window before the second downlink scheduling window. The session management network element determines the first delay based on the boundary of the third scheduling window.

[0013] Referring to the first aspect, in some implementations of the first aspect, the configuration information of the radio resource includes a slot start time, a slot duration, an uplink-downlink slot configuration, and a scheduling processing delay of the access network element.

[0014] Referring to the first aspect, in some implementations of the first aspect, the session management network element obtaining the first delay includes the session management network element obtaining an estimated time when the downlink service packet arrives at the access network element. The session management network element transmits the estimated time when the downlink service packet arrives at the access network element to the access network element. The session management network element receives the first delay from the access network element.

[0015] Referring to the first aspect, in some implementations of the first aspect, the session management network element obtaining an estimated time when a downlink service packet arrives at an access network element includes a step of the session management network element determining an estimated time when the downlink service packet arrives at the access network element based on a transmission delay from the user plane network element to the access network element and the estimated time when the downlink service packet arrives at the user plane network element, or a step of the session management network element obtaining quality of service (QoS) information of the downlink service from a policy control network element, and determining an estimated time when the downlink service packet arrives at the access network element based on the QoS information.

[0016] Referring to the first aspect, in some implementations of the first aspect, when the first network element is a user plane network element, the time adjustment information is a fourth time point determined based on the first delay or the first delay and an estimated time point at which the downlink service packet arrives at the user plane network element.

[0017] Referring to the first aspect, in some implementations of the first aspect, when the first network element is an application network element, the time adjustment information includes one or more of a first delay, an expected time at which the downlink service packet, determined based on the first delay, arrives at the user plane network element, and an expected time at which the downlink service packet, determined based on the first delay, arrives at the terminal device.

[0018] Referring to the first aspect, in some implementations of the first aspect, the method further includes the step of: the session management network element determining a third time point based on the time adjustment information. The session management network element sends the third time point to the access network element, and the third time point is used by the access network element to schedule the downlink service packet.

[0019] For example, in order to reduce the end-to-end transmission delay of the downlink service packet and save the control plane resource, the access network element can perform semi-persistent scheduling for the downlink service packet based on the periodicity of the downlink service packet and the time when the downlink service packet arrives at the access network element, i.e., can allocate the same time-frequency resource once to the downlink service packet, which can be used repeatedly periodically.

[0020] According to a second aspect, a downlink transmission method is provided, the method including: a user plane network element receiving time adjustment information related to a first delay from a session management network element, the first delay being a period between an expected time when a downlink service packet arrives at the access network element and an estimated time when the downlink service packet arrives at the access network element, the expected time when the downlink service packet arrives at the access network element is within a first scheduling window, and a next scheduling window adjacent to the first scheduling window is a downlink scheduling window. The user plane network element determines a first time when the user plane network element transmits the downlink service packet based on the time adjustment information, and a third time when the downlink service packet transmitted at the first time arrives at the access network element is within the first scheduling window.

[0021] According to the downlink transmission method provided in the present application, the user plane network element can adjust the time point of sending the downlink service packet based on the time adjustment information provided by the session management network element, so that when the downlink service packet is sent at the adjusted sending time point, the time point of the downlink service packet arriving at the access network element can be within a first scheduling window of the access network element, and the downlink service packet can be scheduled within a second downlink scheduling window, which is the next scheduling window adjacent to the first scheduling window. This helps to reduce the scheduling waiting delay of scheduling the downlink service by the access network element, and also helps to guarantee the end-to-end delay of the downlink service packet. In addition, the user plane network element usually receives multiple downlink service packets for multiple access network elements. According to the method, the user plane network element can buffer a downlink service packet while preferentially processing another downlink service packet, so as to make appropriate use of resources, reduce and avoid processing contention between downlink service packets transmitted to different access network element nodes, improve the processing efficiency of the downlink service packet in the user plane network element, and help guarantee the end-to-end delay requirements of the downlink service packet and another downlink service packet.

[0022] Referring to the second aspect, in some implementations of the second aspect, the time adjustment information is a first delay or a fourth point in time determined based on the first delay and an estimated point in time at which the downlink service packet arrives at the user plane network element.

[0023] According to a third aspect, a downlink transmission method is provided, the method including: an application network element receiving time adjustment information related to a first delay from a session management network element, the first delay being a period between an expected time when a downlink service packet arrives at the access network element and an estimated time when the downlink service packet arrives at the access network element, the expected time when the downlink service packet arrives at the access network element is within a first scheduling window, and a next scheduling window adjacent to the first scheduling window is a downlink scheduling window. The application network element determines a second time when an application server transmits the downlink service packet based on the time adjustment information, and a third time when the downlink service packet transmitted at the second time arrives at the access network element is within the first scheduling window.

[0024] According to the downlink transmission method provided in the present application, the application network element can adjust the time point at which the application server sends the downlink service packet based on the time adjustment information provided by the session management network element, so that when the downlink service packet is sent at the adjusted sending time point, the time point at which the downlink service packet arrives at the access network element can be within a first scheduling window of the access network element, and the downlink service packet can be scheduled within a second downlink scheduling window, which is the next scheduling window adjacent to the first scheduling window. This helps to reduce the scheduling waiting delay of scheduling the downlink service by the access network element, and also helps to guarantee the end-to-end delay of the downlink service packet. In addition, the application server usually receives multiple downlink service packets for multiple access network elements. According to the method, the application server can buffer a downlink service packet while preferentially processing another downlink service packet, so as to make proper use of resources, mitigate and avoid processing collisions between downlink service packets sent to different access network element nodes, improve the processing efficiency of the downlink service packet in the application server, and help guarantee the end-to-end delay requirements of the downlink service packet and another downlink service packet.

[0025] With reference to the third aspect, in some implementations of the third aspect, the time adjustment information includes one or more of a first delay, an expected time at which the downlink service packet arrives at the user plane network element, determined based on the first delay, and an expected time at which the downlink service packet arrives at the terminal device, determined based on the first delay.

[0026] According to a fourth aspect, a downlink transmission method is provided, the method including a step of an access network element receiving an estimated time when a downlink service packet arrives at the access network element from a session management network element. The access network element determines a first delay based on the estimated time when the downlink service packet arrives at the access network element, the first delay being a period between a time when the downlink service packet expected by the access network element arrives at the access network element and the estimated time when the downlink service packet arrives at the access network element, the time when the downlink service packet expected by the access network element arrives at the access network element is within a first scheduling window, and a next scheduling window adjacent to the first scheduling window is a downlink scheduling window. The access network element transmits the first delay to the session management network element, and the first delay is used by the session management network element to adjust a time when the user plane network element transmits the downlink service packet and / or a time when the application server transmits the downlink service packet.

[0027] According to the downlink transmission method provided in the present application, the access network element can provide the determined first delay to the session management network element, and the session management network element adjusts the time when the user plane network element transmits the downlink service packet and / or the time when the application server transmits the downlink service packet based on the first delay, so that the user plane network element can transmit the downlink service packet at the adjusted time and / or the application server can transmit the downlink service packet at the adjusted time. In this way, the time when the downlink service packet arrives at the access network element can be within the first scheduling window of the access network element, and the downlink service packet can be scheduled in the second downlink scheduling window, which is the next scheduling window adjacent to the first scheduling window. This helps to reduce the scheduling waiting delay of scheduling the downlink service by the access network element, and also helps to guarantee the end-to-end delay requirement of the downlink service packet.

[0028] Referring to the fourth aspect, in some implementations of the fourth aspect, determining the first delay based on an estimated time when the downlink service packet arrives at the access network element includes a step of the access network element determining the first delay based on the estimated time when the downlink service packet arrives at the access network element and configuration information of radio resources of the access network element.

[0029] Referring to the fourth aspect, in some implementations of the fourth aspect, the configuration information of the radio resource includes a slot start time, a slot duration, an uplink-downlink slot configuration, and a scheduling processing delay of the access network element.

[0030] Referring to the fourth aspect, in some implementations of the fourth aspect, the determining of the first delay by the access network element based on the estimated time when the downlink service packet arrives at the access network element and the configuration information of the radio resource of the access network element includes determining an estimated second downlink scheduling window for the access network element to schedule the downlink service based on the configuration information of the radio resource and the estimated time when the downlink service packet arrives at the access network element. The access network element determines a boundary of a third scheduling window based on the configuration information of the radio resource and the second downlink scheduling window, the third scheduling window being a scheduling window before the second downlink scheduling window. The access network element determines the first delay based on the boundary of the third scheduling window.

[0031] According to a fifth aspect, a downlink transmission method is provided, the method including: an access network element receiving from a session management network element an estimated time when a downlink service packet arrives at the access network element. The access network element determines time adjustment information based on the estimated time when the downlink service packet arrives at the access network element and configuration information of radio resources. The access network element sends the time adjustment information to the session management network element, and the time adjustment information is used by the session management network element to adjust a time when a user plane network element sends the downlink service packet and / or a time when an application server sends the downlink service packet.

[0032] According to the downlink transmission method provided in the present application, the access network element can determine time adjustment information based on the estimated time when the downlink service packet arrives at the access network element and the configuration information of the radio resource, and can provide the time adjustment information to the session management network element. The session management network element can adjust the time when the user plane network element transmits the downlink service packet and / or the application server transmits the downlink service packet based on the time adjustment information, so that the user plane network element can transmit the downlink service packet at the adjusted time and / or the application server can transmit the downlink service packet at the adjusted time. In this way, the time when the downlink service packet arrives at the access network element can be within a first scheduling window of the access network element, and the downlink service packet can be scheduled in a second downlink scheduling window, which is the next scheduling window adjacent to the first scheduling window. This helps to reduce the scheduling waiting delay of scheduling the downlink service by the access network element, and also helps to guarantee the end-to-end delay requirement of the downlink service packet.

[0033] Referring to the fifth aspect, in some implementations of the fifth aspect, determining the time adjustment information based on an estimated time when the downlink service packet arrives at the access network element and configuration information of radio resources includes determining a first delay based on the estimated time when the downlink service packet arrives at the access network element and configuration information of radio resources, the first delay being a period between a time when the downlink service packet expected by the access network element arrives at the access network element and an estimated time when the downlink service packet arrives at the access network element, the time when the downlink service packet expected by the access network element arrives at the access network element is within a first scheduling window, and a next scheduling window adjacent to the first scheduling window is a downlink scheduling window. The access network element determines the time adjustment information based on the first delay.

[0034] Referring to the fifth aspect, in some implementations of the fifth aspect, the step of the access network element determining the time adjustment information based on the estimated time when the downlink service packet arrives at the access network element and the configuration information of the radio resource includes the step of the access network element determining an estimated second downlink scheduling window for the access network element to schedule the downlink service packet based on the estimated time when the downlink service packet arrives at the access network element and the configuration information of the radio resource. The access network element determines a boundary of a third scheduling window based on the second downlink scheduling window, and the third scheduling window is a scheduling window before the second downlink scheduling window. The access network element determines the time adjustment information based on the boundary of the third scheduling window.

[0035] Referring to the fifth aspect, in some implementations of the fifth aspect, the configuration information of the radio resource includes a slot start time, a slot duration, an uplink-downlink slot configuration, and a scheduling processing delay of the access network element.

[0036] According to a sixth aspect, a downlink transmission method is provided, the method including: a session management network element obtains first information, the first information including configuration information of radio resources and an estimated time point at which a downlink service packet arrives at an access network element. The session management network element transmits the first information to a user plane network element, the first information is for determining a first time point at which the user plane network element transmits the downlink service packet, a third time point at which the downlink service packet transmitted at the first time point arrives at the access network element is within a first scheduling window of the access network element, and a next scheduling window adjacent to the first scheduling window is a downlink scheduling window.

[0037] According to the downlink transmission method provided in the present application, the user plane network element can determine the sending time of the downlink service packet according to the first information provided by the session management network element, so that the time when the downlink service packet arrives at the access network element can be within a first scheduling window of the access network element, and the downlink service packet can be scheduled within a second downlink scheduling window, which is the next scheduling window adjacent to the first scheduling window, which helps to reduce the scheduling waiting delay of scheduling the downlink service by the access network element, and also helps to guarantee the end-to-end delay of the downlink service packet.

[0038] Referring to the sixth aspect, in some implementations of the sixth aspect, the configuration information of the radio resource includes a slot start time, a slot duration, an uplink-downlink slot configuration, and a scheduling processing delay of the access network element.

[0039] With reference to the sixth aspect, in some implementations of the sixth aspect, the method further includes a step of: the session management network element receiving second information from the user plane network element, the second information being the first time point or a waiting delay of the downlink service packet on the user plane network element. The session management network element determines a third time point based on the second information. The session management network element transmits the third time point to the access network element.

[0040] According to a seventh aspect, a downlink transmission method is provided, the method including: a user plane network element receives first information from a session management network element, the first information including configuration information of radio resources and an estimated time point at which a downlink service packet arrives at an access network element. The user plane network element determines a first time point at which the downlink service packet is transmitted based on the first information, and a third time point at which the downlink service packet transmitted at the first time point arrives at the access network element is within a first scheduling window of the access network element, and a next scheduling window adjacent to the first scheduling window is a downlink scheduling window.

[0041] According to the downlink transmission method provided in the present application, the user plane network element can determine the sending time of the downlink service packet according to the first information provided by the session management network element, so that the time when the downlink service packet arrives at the access network element can be within a first scheduling window of the access network element, and the downlink service packet can be scheduled within a second downlink scheduling window, which is the next scheduling window adjacent to the first scheduling window, which helps to reduce the scheduling waiting delay of scheduling the downlink service by the access network element, and also helps to guarantee the end-to-end delay of the downlink service packet.

[0042] Referring to the seventh aspect, in some implementations of the seventh aspect, the configuration information of the radio resource includes a slot start time, a slot duration, an uplink-downlink slot configuration, and a scheduling processing delay of the access network element.

[0043] With reference to the seventh aspect, in some implementations of the seventh aspect, the user plane network element determining, based on the first information, a first time point at which the downlink service packet is transmitted includes the user plane network element determining a first delay based on the first information, the first delay being a period between an expected time point at which the downlink service packet arrives at the access network element and an estimated time point at which the downlink service packet arrives at the access network element. The user plane network element determines the first time point based on the first delay.

[0044] With reference to the seventh aspect, in some implementations of the seventh aspect, the method further includes a step of the user plane network element sending second information to the session management network element, where the second information is a first time point or a waiting delay of the downlink service on the user plane network element, and the second information is for determining a third time point.

[0045] According to an eighth aspect, there is provided a communication apparatus, the communication apparatus including a module or unit configured to perform a method according to any one of the first to seventh aspects or possible implementations of the first to seventh aspects.

[0046] According to a ninth aspect, an apparatus is provided, comprising a processor. The processor may be coupled to a memory and configured to execute instructions in the memory, such that the apparatus performs a method according to any one of the first to seventh aspects or possible implementations of the first to seventh aspects. Optionally, the apparatus further comprises the memory. Optionally, the apparatus further comprises an interface circuit, the processor coupled to the interface circuit.

[0047] According to a tenth aspect, a processor is provided, comprising an input circuit, an output circuit, and a processing circuit configured to receive a signal through the input circuit and to transmit a signal through the output circuit, such that the processor performs a method according to any one of the first to seventh aspects or possible implementations of the first to seventh aspects.

[0048] In a specific implementation process, the processor may be a chip, the input circuit may be an input pin, the output circuit may be an output pin, the processing circuit may be a transistor, a gate circuit, a trigger, various logic circuits, etc. The input signal received by the input circuit may be, for example, but not limited to, received and input by a receiver, the signal output by the output circuit may be, for example, but not limited to, output and transmitted by a transmitter, the input circuit and the output circuit may be the same circuit, and the circuit may be used as an input circuit and an output circuit at different times. The specific implementation of the processor and various circuits is not limited in this embodiment of the present application.

[0049] According to an eleventh aspect, a processing device is provided, including a processor and a memory. The processor is configured to read instructions stored in the memory and can receive a signal using the receiver and transmit a signal using the transmitter to perform a method according to any one of the first to seventh aspects and possible implementations of the first to seventh aspects.

[0050] Optionally, there are one or more processors and one or more memories.

[0051] Optionally, the memory may be integrated with the processor, or the memory and the processor may be located separately.

[0052] In a specific implementation, the memory may be a non-transitory memory such as a read only memory (ROM). The memory and the processor may be integrated into the same chip, or may be separately located on separate chips. The type of memory and the manner in which the memory and the processor are located are not limited in this embodiment of the present application.

[0053] The processing device according to the eleventh aspect may be a chip. The processor may be implemented using hardware or software. When the processor is implemented using hardware, the processor may be a logic circuit or an integrated circuit, etc., or when the processor is implemented using software, the processor may be a general-purpose processor, and is implemented by reading software code stored in a memory. The memory may be integrated into the processor, or may exist independently outside the processor.

[0054] According to a twelfth aspect, a computer program product is provided. The computer program product includes a computer program (also called code or instructions). When the computer program is executed, the computer is enabled to perform a method according to any one of the first to seventh aspects or possible implementations of the first to seventh aspects.

[0055] According to a thirteenth aspect, a computer readable medium is provided. The computer readable medium stores a computer program (also called code or instructions). When the computer program is executed on a computer, the computer is enabled to execute a method according to any one of the first to seventh aspects or possible implementations of the first to seventh aspects. [Brief description of the drawings]

[0056] [Figure 1] FIG. 1 is a diagram of the architecture of a system that may be used in the present application. [Diagram 2] A diagram of the 5G system architecture. [Diagram 3] FIG. 1 is a schematic diagram of a TSN centralized management architecture. [Figure 4] FIG. 1 is a diagram of an architecture for achieving end-to-end deterministic transmission of users. [Diagram 5]FIG. 1 is a schematic diagram of scheduling downlink service packets by an access network element in the prior art; [Figure 6] 2 is a schematic flowchart of a downlink transmission method according to the present application; [Figure 7] FIG. 2 is a schematic diagram of scheduling downlink service packets by an access network element according to the present application; [Figure 8] 2 is a schematic flowchart of a downlink transmission method according to the present application; [Figure 9] FIG. 2 is a schematic diagram of scheduling downlink service packets by an application server and an access network element according to the present application; [Figure 10] 2 is a schematic flowchart of a downlink transmission method according to the present application; [Figure 11] 2 is a schematic flowchart of a downlink transmission method according to the present application; [Figure 12] 2 is a schematic flowchart of a downlink transmission method according to the present application; [Figure 13] 1 is a schematic block diagram of a communication device according to the present application; [Figure 14] 2 is a schematic block diagram of another communication device according to the present application; [Figure 15] FIG. 2 is a schematic diagram of the structure of a network device according to the present application; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] The technical solutions of the present application are described below with reference to the accompanying drawings.

[0058] The technical solutions of the embodiments of the present application may be applied to various communication systems, for example, long term evolution (LTE) systems, 5th generation (5G) systems, new radio (NR) systems, or other communication systems that may emerge in the future.

[0059] 1 is an architecture diagram of a system 100 that may be used in the present application. As shown in FIG. 1, the system 100 may include any one or more of the following devices: a terminal device 101, an access network element 102, a user plane network element 103, a data network 104, an access and mobility management network element 105, a session management network element 106, a policy control network element 107, an application network element 108, a unified data management network element 109, and a network exposure network element 110.

[0060] The terminal device 101 may be a user equipment (UE), a user, an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, or a user device, such as a mobile phone, a tablet, a computer with a wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote medical, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, and a wireless terminal in a smart home, etc. The terminal device 110 may alternatively be an apparatus or circuit structure, such as a chip or a chip system, disposed within the various devices mentioned above.

[0061] The access network element 102 can manage radio resources, provide access services for terminal devices, and further complete the transfer of control signals and user data between the terminal devices and the core network.

[0062] The access network element 102 may be a transmission reception point (TRP), an evolved NodeB (eNB or eNodeB) in an LTE system, or a home base station (e.g., home evolved NodeB or home Node B, HNB) or a base band unit (BBU), or a radio controller in a cloud radio access network (CRAN) scenario. Alternatively, the access network device may be a relay station, an access point, an in-vehicle device, a wearable device, an access network device in a 5G network, or an access network device in a future evolved public land mobile network (PLMN), etc., an access point (AP) in a WLAN, or a gNB in ​​a new radio (NR) system. This is not limited in the embodiments of the present application. In a network structure, the access network device may include a centralized unit (CU) node, a distributed unit (DU) node, an access network device including a CU node and a DU node, or an access network device including a CU control plane node (CU-CP node), a CU user plane node (CU-UP node), and a DU node.

[0063] The user plane network element 103 is primarily responsible for processing user packets, eg, forwarding and charging.

[0064] The data network 104 is a carrier network that provides data transmission services to users, such as IP Multi-media Service (IMS) or the Internet. The DN may include an application server (AS). The AS is a software framework that provides an environment in which application programs run and is configured to provide services to the application programs, such as security, data, transaction support, load balancing, and large-scale distributed system management. The terminal device obtains application packets by communicating with the AS. It should be noted that the AF is the control plane of the AS.

[0065] The access and mobility management network element 105 is mainly responsible for mobility management in a mobile network, such as user location update, user network registration, and user handover.

[0066] The session management network element 106 is mainly responsible for session management in the mobile network, such as establishing, modifying, and releasing a session. Specific functions may include, for example, allocating an IP address to a user and selecting a user plane network element that provides a packet forwarding function.

[0067] The policy control network element 107 is responsible for providing policies, such as quality of service (QoS) policies and slice selection policies, to the access and mobility management network elements and the session management network elements.

[0068] The application network element 108 is responsible for providing services to the 3GPP network, interacting with the policy control network element to implement policy control, and so on.

[0069] The unified data management network element 109 is configured to store user data such as subscription information and authentication / authorization information.

[0070] The network exposure network element 110 provides the framework, authentication, and interface related to network capability exposure and transfers information between 5G system network functions and other network functions.

[0071] It should be understood that the aforementioned devices or network elements may be apparatuses having corresponding functions, or may be software / hardware modules (e.g., chips) within an apparatus, etc. It should be further understood that any device or network element of the present application may be implemented in the form of software, or a combination of software and hardware.

[0072] In one example, the system 100 shown in Figure 1 may be the 5G system shown in Figure 2. It should be understood that the system 100 may alternatively be a 4G system or another system, which is not a limitation of this application.

[0073] Figure 2 is a schematic diagram of the architecture of a 5G system. In the diagram of the system architecture, the network elements with the same reference numbers as in Figure 1 are the names of the corresponding network elements in Figure 1 in the current 5G system. Referring to Figure 2, the architecture of the 5G system may include any one or more of the following network elements: UE 101, (radio) access network ((R)AN) 102, user plane function (UPF) 103, data network (DN) 104, access and mobility management function (AMF) 105, session management function (SMF) 106, policy control function (PCF) 107, application function (AF) 108, unified data management (UDM) 109, and network exposure function 110.

[0074] It should be understood that the names of each network element shown in FIG. 2 are merely names, and the names do not limit the functions of the network elements. In another network, the aforementioned network elements may have other names instead. This is not specifically limited in the embodiments of the present application. For example, in a 6G network, some or all of the aforementioned network elements may continue to use 5G terminology or may have other names. A general description is provided here. Details will not be described again below. Similarly, the interfaces between the network elements shown in FIG. 2 are merely examples. In a 5G network and another future network, the interfaces between the network elements may instead not be the interfaces shown in the figure. This is not limited in the present application.

[0075] It should be further understood that the embodiments of the present application are not limited to the architecture of the system shown in Fig. 2. For example, a communication system to which the present application is applicable may include more or less network elements or devices. The devices or network elements in Fig. 2 may be hardware or software obtained by functional division, or a combination of hardware and software. The devices or network elements in Fig. 2 can communicate with each other by using another device or network element.

[0076] In the conventional Ethernet forwarding implementation, if a large number of data packets arrive at a forwarding port instantaneously, a large forwarding delay or packet loss may occur. As a result, conventional Ethernet cannot provide reliable services with guaranteed transmission delays and cannot meet the requirements of fields such as vehicle control and industrial Internet. The Institute of Electrical and Electronics Engineers (IEEE) has specified the time sensitive networking (TSN) standard for the requirements of reliable delay transmission. This standard provides reliable delay transmission services based on Layer 2 switching to guarantee the reliability of data transmission and predictable end-to-end transmission delays for delay-sensitive services.

[0077] TSN is based on Layer 2 transmission and includes TSN switch nodes (also called TSN Bridges) and TSN endpoints (end stations or endpoints). Unlike Layer 2 forwarding, TSN switch nodes do not forward packets based on media access control address (MAC address) learning, but forward packets according to forwarding rules configured or created on the TSN switch node. TSN flows are unidirectional. For TSN flows, TSN endpoints are classified as senders (Talkers) and receivers (Listeners). The TSN standard specifies the behavior of TSN switch nodes and TSN endpoints, as well as the scheduling method by which TSN switch nodes forward data flows, to achieve reliable delay transmission. The TSN switch node uses the destination MAC address of a packet as an identifier of the data flow, and performs resource reservation and scheduling planning based on the delay requirements of the service flow to guarantee reliability and transmission delay according to the generated scheduling policy.

[0078] The TSN standard specifies a TSN centralized management architecture. Figure 3 is a schematic diagram of the TSN centralized management architecture. Please refer to Figure 3. This architecture includes TSN endpoints (Talker / Listener), TSN switch nodes, and control plane network elements. The control plane network elements include a centralized user configuration (CUC) and a centralized network configuration (CNC). The details are as follows:

[0079] A TSN endpoint is the sender or receiver of a data flow.

[0080] A TSN switch node reserves resources for a data flow and schedules and forwards data packets according to TSN regulations.

[0081] The CNC manages the topology of the TSN user plane and the capability information of the TSN switch nodes (e.g., the transmission delay of the TSN switch node, and the internal processing delay between the ports of the TSN switch node), generates forwarding paths and processing policies (e.g., ports for transmitting and receiving packets, and time gate control parameters) of data flows on the TSN endpoints and TSN switch nodes based on the flow creation request provided by the CUC, and then distributes the processing policies on the TSN switch nodes to the corresponding TSN switch nodes.

[0082] The CUC is responsible for collecting flow creation requests from TSN endpoints, matching the requests of Talkers and Listeners, and then requesting the CNC to create a data flow and verifying the processing policy generated by the CNC.

[0083] The 5G System (5GS) specifies the architecture shown in Figure 4 to realize end-to-end deterministic transmission of users. Please refer to Figure 4. To realize the function of a TSN switch node and realize end-to-end deterministic transmission in TSN including 5GS, the 5GS is simulated as a switch node in TSN (hereinafter referred to as a 5GS switch node). The AF adapts information about the 5GS to information about the TSN switch node, interacts with the CNC, and sends information distributed by the CNC to the 5GS in a 5GS manner. The user plane TSN Translator (Device) (hereinafter referred to as Device Side-TSN Translator (DS-TT)) and the TSN Translator (UP) (hereinafter referred to as Network Side-TSN Translator (NW-TT)) are logical functions of the 5GS user plane, which are for implementing the external functions of the TSN switch node, e.g. topology discovery, and for implementing the CNC scheduling rules. The DS-TT may be deployed with the UE or alone. Similarly, the NW-TT may be deployed with the UPF or alone.

[0084] It should be noted that in this application, the UPF may be replaced by the NW-TT, and the UE may be replaced by the DS-TT.

[0085] In any of the systems shown in Figures 1 to 4, a scheduling delay may be introduced on the access network element side by the downlink service, taking into account the scheduling particularities of the access network element, e.g., uplink-downlink configuration and TTI scheduling protection.

[0086] For example, FIG. 5 is a schematic diagram of scheduling a downlink service packet by an access network element in the prior art. For example, FIG. 5 shows four slots, each of which includes a scheduling window and a processing window. Each scheduling window can be for uplink or downlink. The processing window is used by the access network element to process the downlink service packet. The downlink service packet can be scheduled in the nearest downlink scheduling window only if the downlink service packet arrives before the processing window begins. However, the downlink service packet can arrive at the access network element at any time. For example, as shown in FIG. 5, if the time t1 at which the downlink service packet arrives at the access network element is within the downlink scheduling window 1 of the access network element, the access network element can first schedule the downlink service packet in the next nearest downlink scheduling window (i.e., downlink scheduling window 2). However, if the time t2 at which the downlink service packet arrives at the access network element is within the processing window of the access network element, the downlink service packet can first be scheduled in the next back downlink scheduling window (i.e., downlink scheduling window 3). If the time t3 at which a downlink service packet arrives at an access network element is within the downlink scheduling window 2 of the access network element and the next scheduling window adjacent to the downlink scheduling window 2 is the uplink scheduling window 1, the downlink service packet can only be scheduled when at least the closest downlink scheduling window (i.e., downlink scheduling window 3) arrives.If the time t4 at which the downlink service packet arrives at the access network element is within the uplink scheduling window 1 of the access network element, the access network element can first schedule the downlink service packet in the next closest downlink scheduling window (i.e., downlink scheduling window 3). The downlink service packet received at the time t2 in Fig. 5 needs at least two slots of delay to be scheduled, and the downlink service packet received at the time t3 in Fig. 5 needs at least one slot of delay to be scheduled. Therefore, the scheduling delay introduced on the access network element side may not guarantee the end-to-end delay of the service.

[0087] In view of this, the present application provides a downlink transmission method to reduce the scheduling delay on the access network element side. In the following, the method provided in the present application is described using the naming of corresponding network elements in a 5G network as an example.

[0088] Note that the duration of the processing window is equal to the scheduling processing delay of the RAN: The processing window is used by the access network element to process the downlink service packet. The downlink service packet can be scheduled in the nearest downlink scheduling window only if the downlink service packet arrives before the processing window begins. The downlink service packet that arrives in the processing window needs to be scheduled in the next following nearest downlink scheduling window, i.e., at least one more slot needs to be waited.

[0089] It should be noted that the downlink service described in this application may be a periodic service. In other words, the service packets may be transmitted at regular intervals. The regular interval is the transmission period of the downlink service packets. Usually, the size of the packets transmitted periodically in industrial scenarios may also be fixed.

[0090] In this application, the SMF and the AF may not communicate directly with each other, but may use network elements such as PCF and NEF to communicate with each other, which is not limited in this application. The SMF and the RAN may not communicate directly with each other, but may use AMF to communicate with each other.

[0091] In this application, unless otherwise specified, the same terms have the same meaning in various embodiments. For example, the first time adjustment information is only described in the method 600. Please refer to the description of the method 600 for the meaning of the first time adjustment information below.

[0092] 6 is a schematic flow chart of a downlink transmission method according to the present application. The method 600 shown in FIG. 6 will now be described.

[0093] S601: The SMF obtains a first delay.

[0094] The first delay is a period between an expected time when the downlink service packet arrives at the RAN and an estimated time when the downlink service packet arrives at the RAN. The expected time when the downlink service packet arrives at the RAN is within a first scheduling window, and the next scheduling window adjacent to the first scheduling window is a downlink scheduling window. The "estimated" may be understood as "originally scheduled" rather than actually occurring.

[0095] In this specification, the time when the downlink service packet expected by the RAN arrives at the RAN is t RANyt and the estimated time when the downlink service packet arrives at the RAN is t RANyaIt is written as follows.

[0096] In this case, the first delay = t RANyt -t RANya It is.

[0097] For example, t RANyt is 10:30 and t RANya Suppose the time is 10:29, then the first delay is 1min.

[0098] In the following, two methods are described in which the SMF obtains the first delay.

[0099] Method 1: The first delay provided by the SMF is determined by the SMF.

[0100] Optionally, the SMF may store information about the configuration of radio resources in the RAN and the estimated time t when the downlink service packets arrive at the RAN. RANya , and obtains the radio resource configuration information and the estimated time t RANya The first delay may be determined based on:

[0101] For example, the radio resource configuration information may include at least one of a slot start time, a slot duration, or a number of symbols in a slot, an uplink-downlink slot configuration, and a scheduling processing delay of the RAN. Based on the radio resource configuration information, the SMF can determine the boundaries of the scheduling window, the boundaries of the processing window, and whether the scheduling window is an uplink scheduling window or a downlink scheduling window in FIG. 5.

[0102] For example, the RAN can report radio resource configuration information and corresponding cell IDs to the AMF in an NG setup process, and the SMF can obtain the radio resource configuration information and cell IDs from the AMF. The NG setup process may also be called an N2 setup process, and the interface between the RAN and the AMF is called an NG interface.

[0103] Alternatively, in the registration process of the UE, when the RAN forwards a registration request to the AMF, the registration request may carry a cell ID and radio resource configuration information, or may carry a cell ID, a UE ID, and radio resource configuration information. Then, the SMF can obtain the radio resource configuration information from the AMF.

[0104] Alternatively, at the time of session setup, the RAN may send the cell ID and corresponding configuration information of radio resources, or may send the cell ID, the UE ID, and corresponding configuration information of radio resources to the SMF in an N2 message.

[0105] Alternatively, the RAN may provide configuration information of radio resources corresponding to the cell to a network data analytics function (NWDAF) network element, and the SMF may obtain the configuration information of the radio resources and the corresponding cell ID from the NWDAF.

[0106] In one example, the SMF determines an estimated time t t t t t t t t t RANya can be determined.

[0107] In this specification, the transmission delay from the UPF to the RAN is T UPF-RAN The estimated time when the downlink service packet arrives at the UPF is t UPFya It is written as follows.

[0108] For example, tRANya =T UPF-RAN +t UPFya Or, t RANya =T UPF-RAN +t UPFya +T UPF and T UPF is the buffer (or queue) time of downlink service packets in UPF. T UPF may be determined by the SMF or UPF based on the delay requirement or service priority in the QoS information, but this is not limited in this application.

[0109] In another example, the SMF may obtain QoS information of a downlink service packet (or a downlink service) from the PCF, and determine an estimated time when the downlink service packet will arrive at the RAN based on the QoS information.

[0110] Specifically, the QoS information or PCC rule provided by the PCF includes an estimated time when the downlink service packet arrives at the UPF. The SMF receives the QoS information or PCC rule from the PCF, obtains the estimated time when the downlink service packet arrives at the UPF, and then determines the estimated time when the downlink service packet arrives at the RAN based on the estimated time when the downlink service packet arrives at the UPF. The QoS information or PCC rule may further include a period of the downlink service packet and a total number of service packets in the period.

[0111] Further, the SMF determining the first delay based on the configuration information of the radio resources and the estimated time when the downlink service packet arrives at the RAN may include the steps of: the SMF determining an estimated second downlink scheduling window for the RAN to schedule the downlink service packet based on the configuration information of the radio resources and the estimated time when the downlink service packet arrives at the RAN; the SMF determining a boundary of a third scheduling window based on the second downlink scheduling window, where the third scheduling window is a scheduling window before the second downlink scheduling window; and the SMF determining the first delay based on the boundary of the third scheduling window.

[0112] In the following, an explanation is provided by way of an example with reference to FIG.

[0113] Example 1: Estimated time t when a downlink service packet arrives at the RAN RANyaAssuming that t1 is t1, the SMF can determine, based on the radio resource configuration information and t1, that the estimated second downlink scheduling window for the RAN to schedule the downlink service packet is the downlink scheduling window 2. In this case, the expected time when the downlink service packet arrives at the RAN is within the third scheduling window, which is the scheduling window before the second downlink scheduling window, i.e., the downlink scheduling window 1. The first delay can be a period T2 between the upper limit of the downlink scheduling window 1 (i.e., the boundary of the two boundaries of the downlink scheduling window 1 that is closer to the downlink scheduling window 2) and t1. Alternatively, the first delay can be any value less than T2. ​​In Example 1, the expected time when the downlink service packet arrives at the RAN can be understood as the upper limit of the downlink scheduling window 1, or as any time between t1 (including t1) and the upper limit of the downlink scheduling window 1.

[0114] Example 2: Estimated time t when a downlink service packet arrives at the RAN RANyaAssuming that the time t1 is t2, the SMF can determine, based on the radio resource configuration information and t2, that the estimated second downlink scheduling window for the RAN to schedule the downlink service packet is the downlink scheduling window 3. In this case, the expected time when the downlink service packet arrives at the RAN is within the third scheduling window, and the third scheduling window is the scheduling window before the second downlink scheduling window, i.e., the uplink scheduling window 1. The first delay may be a period T3 between the lower limit of the uplink scheduling window 1 (i.e., the boundary of the two boundaries of the uplink scheduling window 1 that is closer to the downlink scheduling window 2) and t2. Alternatively, the first delay may be a period T4 between the upper limit of the uplink scheduling window 2 (i.e., the boundary of the two boundaries of the uplink scheduling window 2 that is closer to the downlink scheduling window 3) and t2. Alternatively, the first delay may be any value greater than T3 and less than T4. In Example 2, the expected time at which the downlink service packet arrives at the RAN may be understood as the upper limit of uplink scheduling window 1, or any time between the lower limit of uplink scheduling window 1 (including the lower limit of uplink scheduling window 1) and the upper limit of uplink scheduling window 1.

[0115] Example 3: Estimated time t when a downlink service packet arrives at the RAN RANyaAssuming that the time t1 is t3, the SMF can determine, based on the radio resource configuration information and t3, that the estimated second downlink scheduling window for the RAN to schedule the downlink service packet is the downlink scheduling window 3. In this case, the expected time when the downlink service packet arrives at the RAN is within the third scheduling window, which is the scheduling window before the second downlink scheduling window, i.e., the uplink scheduling window 1. The first delay may be a period T5 between the lower limit of the uplink scheduling window 1 and t3. Alternatively, the first delay may be a period T6 between the upper limit of the uplink scheduling window 1 and t3. Alternatively, the first delay may be any value greater than T5 and less than T6. In Example 3, the expected time when the downlink service packet arrives at the RAN may be understood as the upper limit of the uplink scheduling window 1, or as any time between the lower limit of the uplink scheduling window 1 (including the lower limit of the uplink scheduling window 1) and the upper limit of the uplink scheduling window 1.

[0116] Example 4: Estimation of the time t when a downlink service packet arrives at the RAN RANyaAssuming that t4 is t4, the SMF can determine, based on the radio resource configuration information and t4, that the estimated second downlink scheduling window for the RAN to schedule the downlink service packet is the downlink scheduling window 3. In this case, the expected time when the downlink service packet arrives at the RAN is within the third scheduling window, which is the scheduling window before the second downlink scheduling window, i.e., the uplink scheduling window 1. The first delay may be a period T7 between the upper limit of the uplink scheduling window 1 and t4. Alternatively, the first delay may be any value less than T7. In Example 4, the expected time when the downlink service packet arrives at the RAN may be understood as the upper limit of the uplink scheduling window 1, or as any time between t4 (including t4) and the upper limit of the uplink scheduling window 1. In the above example, the first delay may instead be a time range. For example, the first delay in example 1 may be [0,T2], the first delay in example 2 may be [T3,T4], the first delay in example 3 may be [T5,T6], and the first delay in example 4 may be [0,T7].

[0117] Method 2: The SMF may obtain the first delay from the RAN, in other words, the RAN may determine the first delay and transmit the first delay to the SMF.

[0118] For example, the SMF may estimate the time t when a downlink service packet arrives at the RAN. RANya Then, the estimated time t RANya The RAN can transmit the estimated time t RANya The estimated time t when the downlink service packet arrives at the RAN after receiving RANya and then transmitting the first delay to the SMF.

[0119] For example, the RAN may determine the estimated time t RANya Based on the radio resource configuration information, the first delay can be determined. RANya For details of how to determine the first delay based on the radio resource configuration information, see the estimated time t RANya Please refer to the above description of determining the first delay by the SMF based on the configuration information of the radio resource and the SMF, and the details will not be described again here.

[0120] In addition, the estimated time t when the downlink service packet arrives at the RAN RANya The way in which the SMF obtains the ,is described below. RANya See also the above explanation of how the SMF obtains the . The details will not be repeated here.

[0121] Optionally, S601 may determine the estimated time t when the downlink service packet arrives at the RAN. RANya Only if t is within the processing window of the RAN, or RANya For example, the estimated time t RANya If is t1 or t4, step S601 may not be performed, in other words, method 600 is not performed.

[0122] S602: The SMF sends time adjustment information related to the first delay to the UPF (ie, an example of a first network element). Correspondingly, the UPF receives the time adjustment information from the SMF.

[0123] Hereinafter, this time adjustment information is referred to as the first time adjustment information. It should be understood that the first delay may be a time point or a time range, so the first time adjustment information may be a time point or a time range.

[0124] The first time adjustment information may be a first delay. Alternatively, the first time adjustment information may be a first delay and an estimated time t at which the downlink service packet arrives at the UPF. UPFya and a fourth time point determined based on the above.

[0125] The fourth time point is the expected time point when the UPF transmits the downlink service packet. For example, the fourth time point=t UPFya + 1st delay. Or, 4th time point = t UPFya +First Delay+T UPF It is. UPF For the meaning of t, see above. If the first delay is a time range, the SMF may set a specific value within the time range as t to obtain the fourth point in time. UPFya to, or t UPFya and T UPF Alternatively, the SMF can add the time range to t to obtain a new time range. UPFya to, or t UPFya and T UPF and the resulting new time range may be used as the fourth time point, or any time point within the resulting new time range may be used as the fourth time point.

[0126] S603: The UPF determines, based on the first time adjustment information, a time point (denoted as a first time point) for sending a downlink service packet.

[0127] The time when the downlink service packet transmitted by the UPF at the first time arrives at the RAN (denoted as the third time) is within the first scheduling window of the RAN, and the next scheduling window adjacent to the first scheduling window is the downlink scheduling window. In other words, since the UPF transmits the downlink service packet at the first time, the downlink service packet can be scheduled in the fourth downlink scheduling window after arriving at the RAN, and the fourth downlink scheduling window is the next scheduling window adjacent to the first scheduling window.

[0128] For example, when the first time adjustment information is a first delay, the UPF determines that the first time point is an estimated time t UPFya and the first delay.

[0129] For example, when the first time adjustment information is the fourth time point, the UPF determines that the first time point is the fourth time point or that the first time point is T from the fourth time point. UPF It can be determined that the time is obtained by subtracting

[0130] It should be understood that when the first time adjustment information is a specific time point, the fourth time point is a specific time point.When the first time adjustment information is a time range, the fourth time point can be any value within the new time range obtained according to the above calculation method.

[0131] S604: Upon receiving the downlink service packet, the UPF sends the downlink service packet at a first time point.

[0132] An example is provided with reference to FIG. 7 for explanation. Please refer to FIG. 7. If the UPF transmits a downlink service packet at time t5 according to the original schedule, the time when the downlink service packet arrives at the RAN is t2, and the downlink service packet needs to be buffered at least two slots on the RAN side before being scheduled. That is, the downlink service packet can be scheduled first in the downlink scheduling window 3. If the transmission time of the downlink service packet is adjusted to the first time, the time when the downlink service packet arrives at the RAN is within the first scheduling window of the RAN, so the time when the RAN buffers the downlink service packet is shortened. For example, if the first time is t7, the time when the downlink service packet arrives at the RAN is within the uplink scheduling window 1 of the RAN, and the uplink scheduling window 1 is the previous scheduling window adjacent to the downlink scheduling window 3, and the time when the RAN buffers the downlink service packet can be shortened by a period of t7-t5. As another example, if the UPF transmits a downlink service packet at time t6 according to the original schedule, the time when the downlink service packet arrives at the RAN is t3, and the downlink service packet needs to be buffered at least one slot on the RAN side before being scheduled, that is, the downlink service packet may be first scheduled in the downlink scheduling window 3. If the transmission time of the downlink service packet is adjusted to the first time, the time when the downlink service packet arrives at the RAN is within the first scheduling window of the RAN, so that the time when the RAN buffers the downlink service packet is reduced.For example, if the first time point is t7, the time point t4 at which the downlink service packet arrives at the RAN is within the uplink scheduling window 1 of the RAN, and the uplink scheduling window 1 is the previous scheduling window adjacent to the downlink scheduling window 3, and the time for buffering the downlink service packet in the RAN may be shortened by a period of t7-t6.

[0133] Therefore, according to the downlink transmission method provided in the present application, the UPF can adjust the transmission time of the downlink service packet based on the time adjustment information provided by the SMF, so that when the UPF transmits the downlink service packet at the adjusted transmission time, the time when the downlink service packet arrives at the RAN can be within a first scheduling window of the RAN, and the downlink service packet can be scheduled within a second downlink scheduling window, which is the next scheduling window adjacent to the first scheduling window. This helps to reduce the scheduling waiting delay of scheduling the downlink service packet by the access network element. In addition, the UPF is usually connected to multiple RANs and receives multiple downlink service packets. According to the method, the UPF can prioritize processing of another downlink service packet while buffering the downlink service packet, so as to properly use resources, mitigate and avoid processing contention between the downlink service packets transmitted to different RANs, improve the processing efficiency of the downlink service packet in the UPF, and help guarantee the end-to-end delay requirement of the downlink service packet and another downlink service packet.

[0134] Optionally, the method may further comprise the following steps:

[0135] S605: The SMF determines a third time point based on the first time adjustment information.

[0136] Specifically, the third time point is the time point when the downlink service packet arrives at the RAN. For example, the third time point=t RANya + the first time adjustment information, or the third time point = the fourth time point + T UPF-RAN Alternatively, the third time point is the expected time t RANyt is the same as t RANya and T UPF-RAN For the meaning of, please refer to the explanation above.

[0137] Since the first time adjustment information may be a time point or may be a time range, the third time point may be a time point or may be a time range.

[0138] S606: The SMF sends the third point in time to the RAN, where the third point in time is used by the RAN to schedule downlink service packets.

[0139] Specifically, after receiving a third time point related to the downlink service packet sent by the SMF, the RAN can determine a time point at which the downlink service packet arrives at the RAN based on the third time point. After determining a time point at which the downlink service packet arrives at the RAN, the RAN can schedule the downlink service packet based on the time point. For example, in order to reduce the end-to-end transmission delay of the downlink service packet and save control plane resources, the RAN can perform semi-persistent scheduling for the downlink service packet based on the periodicity of the downlink service packet and the time point at which the downlink service packet arrives at the RAN, i.e., can allocate the same time-frequency resource to the downlink service packet once, which can be repeatedly used periodically.

[0140] 8 is an exemplary flowchart of another downlink transmission method according to the present application. The method 800 shown in FIG. 8 will be described below.

[0141] S801: The SMF obtains a first delay.

[0142] The first delay is a period between an expected time when the downlink service packet arrives at the RAN and an estimated time when the downlink service packet arrives at the RAN, where the expected time when the downlink service packet arrives at the RAN is within a first scheduling window, and the next scheduling window adjacent to the first scheduling window is a downlink scheduling window. "Estimated" may be understood as "originally scheduled" rather than actually occurring.

[0143] In this specification, the expected time when a downlink service packet arrives at the RAN is t RANyt and the estimated time when the downlink service packet arrives at the RAN is t RANya It is written as follows.

[0144] In this case, the first delay = t RANyt -t RANya It is.

[0145] For example, t RANyt is 10:30 and t RANya Suppose the time is 10:29, then the first delay is 1min.

[0146] In the following, two methods are described in which the SMF obtains the first delay.

[0147] Method 1: The first delay provided by the SMF is determined by the SMF.

[0148] Optionally, the SMF may store information about the configuration of radio resources in the RAN and the estimated time t when the downlink service packets arrive at the RAN. RANya , and obtains the radio resource configuration information and the estimated time t RANyaThe first delay may be determined based on:

[0149] For example, the radio resource configuration information may include information such as a slot start time, a slot duration, or the number of symbols in a slot that may be used to estimate the slot duration, an uplink-downlink slot configuration, and a RAN scheduling processing delay.

[0150] For example, the RAN can report radio resource configuration information and corresponding cell IDs to the AMF in an NG setup process, and the SMF can obtain the radio resource configuration information and cell IDs from the AMF. The NG setup process may also be called an N2 setup process, and the interface between the RAN and the AMF is called an NG interface.

[0151] Alternatively, in the registration process of the UE, when the RAN forwards a registration request to the AMF, the registration request may carry a cell ID and radio resource configuration information, or may carry a cell ID, a UE ID, and radio resource configuration information. Then, the SMF can obtain the radio resource configuration information from the AMF.

[0152] Alternatively, at the time of session setup, the RAN may send the cell ID and corresponding configuration information of radio resources, or may send the cell ID, the UE ID, and corresponding configuration information of radio resources to the SMF in an N2 message.

[0153] Alternatively, the RAN may provide configuration information of radio resources corresponding to the cell to a network data analytics function (NWDAF) network element, and the SMF may obtain the configuration information of the radio resources and the corresponding cell ID from the NWDAF.

[0154] In one example, the SMF determines an estimated time t t t t t t t t t RANya can be determined.

[0155] In this specification, the transmission delay from the UPF to the RAN is T UPF-RAN The estimated time when the downlink service packet arrives at the UPF is t UPFya It is written as follows.

[0156] For example, t RANya =T UPF-RAN +t UPFya Or, t RANya =T UPF-RAN +t UPFya +T UPF and T UPF is the buffer (or queue) time of downlink service packets in UPF. T UPF may be determined by the SMF or UPF based on the delay requirement or service priority in the QoS information, but this is not limited in this application.

[0157] In another example, the SMF may obtain QoS information of a downlink service packet (or a downlink service) from the PCF, and determine an estimated time when the downlink service packet will arrive at the RAN based on the QoS information.

[0158] Specifically, the QoS information or PCC rule provided by the PCF includes an estimated time when the downlink service packet arrives at the UPF. The SMF receives the QoS information or PCC rule from the PCF, obtains the estimated time when the downlink service packet arrives at the UPF, and then determines the estimated time when the downlink service packet arrives at the RAN based on the estimated time when the downlink service packet arrives at the UPF. The QoS information or PCC rule may further include a period of the downlink service packet and a burst size within the period.

[0159] Further, the SMF determining the first delay based on the configuration information of the radio resources and the estimated time when the downlink service packet arrives at the RAN may include the steps of: the SMF determining an estimated second downlink scheduling window for the RAN to schedule the downlink service packet based on the configuration information of the radio resources and the estimated time when the downlink service packet arrives at the RAN; the SMF determining a boundary of a third scheduling window based on the second downlink scheduling window, where the third scheduling window is a scheduling window before the second downlink scheduling window; and the SMF determining the first delay based on the boundary of the third scheduling window.

[0160] For specific examples, see examples 1 to 4 of step S601.

[0161] In addition, the SMF determining the first delay based on the configuration information of the radio resources and the estimated time when the downlink service packet arrives at the RAN may include the steps of: the SMF determining an estimated second downlink scheduling window for the RAN to schedule the downlink service packet based on the configuration information of the radio resources and the estimated time when the downlink service packet arrives at the RAN; the SMF determining a boundary of a fifth scheduling window based on the second downlink scheduling window, where the fifth scheduling window is an expected window in which the RAN schedules the downlink service packet, and the fifth scheduling window is a downlink scheduling window before the second downlink scheduling window; the SMF determining a sixth scheduling window based on a boundary of the fifth scheduling window, where the sixth scheduling window is a scheduling window in which an expected time when the downlink service packet arrives at the RAN is located; and the AMF determining the first delay based on a boundary of the sixth scheduling window.

[0162] It should be understood that the expected time at which the downlink service packet arrives at the RAN determined according to the present method is earlier than or equal to the estimated time at which the downlink service packet arrives at the RAN.

[0163] In the following, an explanation is provided by way of an example with reference to FIG.

[0164] Example 5: Estimation of the time t when a downlink service packet arrives at the RAN RANyaAssuming that the time t1 is t2, the SMF can determine, based on the radio resource configuration information and t2, that the estimated second downlink scheduling window for the RAN to schedule the downlink service packet is the downlink scheduling window 3. In this case, the expected window for the RAN to schedule the downlink service packet is the fifth scheduling window, where the fifth scheduling window is the downlink scheduling window before the second downlink scheduling window, i.e., the downlink scheduling window 2, and the sixth scheduling window is the downlink scheduling window 1. Thus, the first delay may be a period T3' between the lower limit of the downlink scheduling window 1 (i.e., the boundary of the two boundaries of the downlink scheduling window 1 that is farther from the downlink scheduling window 2) and t2. Alternatively, the first delay may be a period T4' between the upper limit of the downlink scheduling window 1 (i.e., the boundary of the two boundaries of the downlink scheduling window 1 that is closer to the downlink scheduling window 2) and t2. Alternatively, the first delay may be any value greater than T4' and less than T3'. In Example 5, the expected time at which a downlink service packet arrives at the RAN may be understood as the upper limit of downlink scheduling window 1, or any time between the lower limit of uplink scheduling window 1 (including the lower limit of uplink scheduling window 1) and the upper limit of uplink scheduling window 1.

[0165] Example 6: Estimation of the time t when a downlink service packet arrives at the RAN RANyaAssuming that the time t1 is t3, the SMF can determine, based on the radio resource configuration information and t3, that the estimated second downlink scheduling window for the RAN to schedule the downlink service packet is the downlink scheduling window 3. In this case, the expected window for the RAN to schedule the downlink service packet is the fifth scheduling window, where the fifth scheduling window is the downlink scheduling window before the second downlink scheduling window, i.e., the downlink scheduling window 2, and the sixth scheduling window is the downlink scheduling window 1. Thus, the first delay may be a period T5' between the lower limit of the downlink scheduling window 1 and t3. Alternatively, the first delay may be a period T6' between the upper limit of the downlink scheduling window 1 and t3. Alternatively, the first delay may be any value greater than T6' and less than T5'. In Example 6, the expected time at which the downlink service packet arrives at the RAN may be understood as the upper limit of uplink scheduling window 1, or any time between the lower limit of uplink scheduling window 1 (including the lower limit of uplink scheduling window 1) and the upper limit of uplink scheduling window 1.

[0166] In the above examples, the first delay may be a time range, e.g., the first delay in Example 5 may be [T4', T3'], and the first delay in Example 6 may be [T6', T5'].

[0167] Method 2: The SMF may obtain the first delay from the RAN, in other words, the RAN may determine the first delay and transmit the first delay to the SMF.

[0168] For example, the SMF may estimate the time t when a downlink service packet arrives at the RAN. RANya Then, the estimated time tRANya The RAN can transmit the estimated time t RANya The estimated time t when the downlink service packet arrives at the RAN after receiving RANya and then transmitting the first delay to the SMF.

[0169] For example, the RAN may determine the estimated time t RANya Based on the radio resource configuration information, the first delay can be determined. RANya For details of how to determine the first delay based on the radio resource configuration information, see the estimated time t RANya Please refer to the above description of determining the first delay by the SMF based on the configuration information of the radio resource and the SMF, and the details will not be described again here.

[0170] In addition, the estimated time t when the downlink service packet arrives at the RAN RANya The way in which the SMF obtains the ,is described below. RANya See also the above explanation of how the SMF obtains the . The details will not be repeated here.

[0171] Optionally, S801 may determine the estimated time t when the downlink service packet arrives at the RAN. RANya Only if t is within the processing window of the RAN, or RANya For example, the estimated time t RANya If is t1 or t4, step S801 may not be performed, in other words, method 800 is not performed.

[0172] S802: The SMF sends time adjustment information related to the first delay to the AF (i.e., another example of the first network element). Correspondingly, the AF receives the time adjustment information from the SMF.

[0173] Hereinafter, this time adjustment information is referred to as second time adjustment information.

[0174] Optionally, the second time adjustment information may include any one or more of the first delay, an expected time at which the downlink service packet arrives at the UPF, determined based on the first delay, and an expected time at which the downlink service packet arrives at the UE, determined based on the first delay.

[0175] For example, if the second time adjustment information is a first delay, the SMF can instruct the AF whether the first delay is an advance or a retardation. For example, if the first delay is determined based on a boundary of the third scheduling window, the first delay is a retardation, or if the first delay is determined based on a boundary of the sixth scheduling window, the first delay is an advance. If the first delay is an advance, the transmission time of the downlink service packet determined by the AF is earlier than the estimated transmission time by the first delay, or if the first delay is a retardation, the transmission time of the downlink service packet determined by the AF is later than the estimated transmission time by the first delay.

[0176] Optionally, the SMF may provide an additional instruction for AF only if the first delay is a retardation, otherwise the first delay is an advance.

[0177] Optionally, the SMF may instead provide both an advance first delay and a retardation first delay for the AF to select from.

[0178] It should be understood that if the second time adjustment information is not the first delay, or further includes an item other than the first delay among the aforementioned items, the SMF first determines the second time adjustment information, or an item other than the first delay among the aforementioned items, based on the first delay, and then sends the determined information to the AF.

[0179] For example, the expected time when the downlink service packet arrives at the UPF may be the sum or difference of the estimated time when the downlink service packet arrives at the UPF and the first delay. For example, if the first delay is determined based on the boundary of the third scheduling window, the expected time when the downlink service packet arrives at the UPF may be the sum of the estimated time when the downlink service packet arrives at the UPF and the first delay, or if the first delay is determined based on the boundary of the sixth scheduling window, the expected time when the downlink service packet arrives at the UPF may be the difference between the estimated time when the downlink service packet arrives at the UPF and the first delay.

[0180] The expected time when the downlink service packet arrives at the UE may be the sum or difference of the estimated time when the downlink service packet arrives at the UE and the first delay. For example, when the first delay is determined based on the boundary of the third scheduling window, the expected time when the downlink service packet arrives at the UE may be the sum of the estimated time when the downlink service packet arrives at the UE and the first delay, or when the first delay is determined based on the boundary of the sixth scheduling window, the expected time when the downlink service packet arrives at the UPF may be the difference between the estimated time when the downlink service packet arrives at the UE and the first delay.

[0181] The first delay may be a time range, and the second time adjustment information is determined based on the first delay. Thus, the second time adjustment information may be a point in time or may be a time range. If the first delay is a time range, the second time adjustment information may be a time range determined by the SMF based on the first delay. Alternatively, the SMF may determine a time range based on the first delay, and then determine a point in time within the time range as the second time adjustment information based on the time range.

[0182] S803: The AF determines, based on the second time adjustment information, a second time point at which the AS sends the downlink service packet.

[0183] The third time when the downlink service packet transmitted at the second time arrives at the RAN is within the first scheduling window of the RAN, and the next scheduling window adjacent to the first scheduling window is the downlink scheduling window. In other words, since the AS transmits the downlink service packet at the second time, the downlink service packet can be scheduled in the fourth downlink scheduling window after arriving at the RAN, and the fourth downlink scheduling window is the next scheduling window adjacent to the first scheduling window.

[0184] For example, when the second time adjustment information is a first delay, the AF determines that the second time point is the estimated time t ASya The second time point can be determined to be the sum or difference between the first delay and the estimated time t ASya and the first delay, or if the first delay is a retardation, the second time point is the estimated time t ASya and the first delay.

[0185] For example, if the second time adjustment information is an expected time when the downlink service packet arrives at the UPF, the AF may estimate the estimated time t UPFya and the expected time t UPFqa The second time point can be determined based on the difference between t and t. Specifically, the second time point = t ASys +t UPFqa -t UPFya and t ASys is the estimated time when the AS transmits a downlink service packet.

[0186] For example, if the second time adjustment information is an expected time when the downlink service packet arrives at the UE, the AF may be set to an estimated time t UEya and the expected time t UEqa The second time point can be determined based on the difference between t and t. Specifically, the second time point = t ASys +t UEqa -t UEya and t ASys is the estimated time when the AS transmits a downlink service packet.

[0187] If the second time adjustment information is a time range, the AF can first determine a specific time point in the time range based on the time range, and then determine a second time point based on the specific time point. Alternatively, the AF may directly determine the time range based on the second time adjustment information, and the AF further determines a second time point in the time range based on the time range.

[0188] S804: The AF transmits the second time point to the AS.

[0189] S805: The AS sends a downlink service packet at a second time.

[0190] An example is provided to illustrate with reference to FIG. 9. Please refer to FIG. 9. If an AS transmits a downlink service packet at time t9, the time when the downlink service packet arrives at the RAN is t2, and the downlink service packet needs to be buffered at least two slots on the RAN side before being scheduled. That is, the downlink service packet can be first scheduled in the downlink scheduling window 3. If the transmission time of the downlink service packet is adjusted to a second time, the time when the downlink service packet arrives at the RAN is within the first scheduling window of the RAN, so the time when the RAN buffers the downlink service packet is shortened. For example, if the second time is t11, the time when the downlink service packet arrives at the RAN is within the uplink scheduling window 1 of the RAN, and the uplink scheduling window 1 is a previous scheduling window adjacent to the downlink scheduling window 3, and the time when the downlink service packet buffers the downlink service packet can be shortened by a period of t11-t9. As another example, when the second time point is t8, the time point when the downlink service packet arrives at the RAN is within the downlink scheduling window 1 of the RAN, the downlink service packet can be scheduled in the downlink scheduling window 2 by buffering one slot, and the time for buffering the downlink service packet can be shortened by one slot.

[0191] As another example, if an AS transmits a downlink service packet at time t10, the time when the downlink service packet arrives at the RAN is t3, and the downlink service packet needs to be buffered in at least one slot on the RAN side before being scheduled. That is, the downlink service packet may be first scheduled in the downlink scheduling window 3. If the transmission time of the downlink service packet is adjusted to a second time, the time when the downlink service packet arrives at the RAN is within the first scheduling window of the RAN, so the time when the RAN buffers the downlink service packet is shortened. For example, if the second time is t11, the time when the downlink service packet arrives at the RAN is within the uplink scheduling window 1 of the RAN, and the uplink scheduling window 1 is a previous scheduling window adjacent to the downlink scheduling window 3, and the time when the downlink service packet is buffered may be shortened by a period of t11-t10. As another example, when the second time point is t8, the time point when the downlink service packet arrives at the RAN is within the downlink scheduling window 1 of the RAN, the downlink service packet can be scheduled in the downlink scheduling window 2 by buffering one slot, and the time for buffering the downlink service packet can be shortened by one slot.

[0192] Therefore, according to the downlink transmission method provided in the present application, the AF can adjust the time point at which the AS transmits the downlink service packet based on the time adjustment information provided by the SMF, so that when the AS transmits the downlink service packet at the adjusted transmission time point, the time point at which the downlink service packet arrives at the RAN can be within a first scheduling window of the RAN, and the downlink service packet can be scheduled within a second downlink scheduling window, which is the next scheduling window adjacent to the first scheduling window. This helps to reduce the scheduling waiting delay of scheduling the downlink service by the access network element, and also helps to guarantee the end-to-end delay of the downlink service packet. In addition, the AS usually receives multiple downlink service packets for multiple RANs. According to the method, the AS can preferentially process another downlink service packet while buffering the downlink service packet, so as to properly use resources, mitigate and avoid processing contention between the downlink service packets transmitted to different RAN nodes, improve the processing efficiency of the downlink service packet in the AS, and help guarantee the end-to-end delay requirement of the downlink service packet and another downlink service packet.

[0193] Optionally, the method 800 may further include the following steps.

[0194] S806: The SMF determines a third point in time based on the second time adjustment information.

[0195] The third point in time is when the downlink service packet arrives at the RAN.

[0196] For example, if the second time adjustment information is a first delay and the first delay is an advance, the third time point=t RANya - Second time adjustment information.

[0197] If the second timing information is a first delay, and the first delay is retardation, then the third time point=t RANya +The second time adjustment information.

[0198] The second time adjustment information is an expected time t UPFya If so, then the third time point = t UPFya +T UPF-RAN It is.

[0199] The second time adjustment information is an expected time t UPFya If so, then the third time point = t UEya +T UE-RAN It is.

[0200] t RANya and T UPF-RAN For the meaning of, see the explanation above. UE-RAN is the transmission delay between the UE and the RAN. The second time adjustment information may be a time point or may be a time range, so the third time point may also be a time range.

[0201] S807: The SMF sends a third point in time to the RAN, where the third point in time is used by the RAN to schedule downlink service packets.

[0202] Step S807 is the same as step S606. For details, please refer to the above description of step S606. The details will not be described again here.

[0203] It should be noted that the methods 600 and 800 may be used separately or in combination.

[0204] 10 illustrates another downlink transmission method according to the present application. Method 1000 is described below.

[0205] S1001: The SMF sends to the RAN an estimated time when a downlink service packet arrives at the RAN. Correspondingly, the RAN receives from the SMF an estimated time when a downlink service packet arrives at the RAN.

[0206] Before the SMF sends the estimated time when the downlink service packet arrives at the RAN to the RAN, the SMF first needs to determine the estimated time when the downlink service packet arrives at the RAN. For the manner in which the SMF determines the estimated time when the downlink service packet arrives at the RAN, please refer to the description of step S601 of the method 600. The details will not be described again here.

[0207] S1002: The RAN determines first time adjustment information based on an estimated time when the downlink service packet arrives at the RAN and configuration information of radio resources.

[0208] Optionally, in a manner, the RAN may determine a first delay based on an estimated time when the downlink service packet arrives at the RAN and configuration information of radio resources, where the first delay is a period between a time when the downlink service packet expected by the RAN arrives at the RAN and an estimated time when the downlink service packet arrives at the RAN, where the time when the downlink service packet expected by the RAN arrives at the RAN is within a first scheduling window, and a next scheduling window adjacent to the first scheduling window is a downlink scheduling window. Then, the RAN determines first time adjustment information based on the first delay.

[0209] The manner in which the RAN determines the first delay is similar to the manner in which the SMF determines the first delay in step S601. For details, please refer to S601. The details will not be described again here.

[0210] The RAN determines the first time adjustment information based on the first delay, and the first time adjustment information may be the first delay. Alternatively, the first time adjustment information may be the first delay and an estimated time t 1 at which the downlink service packet arrives at the RAN. RANya and the fifth time point is an expected time point at which the UPF transmits the downlink service packet. For example, the fifth time point=t RANya +First Delay+T UPF-RAN Alternatively, the first time adjustment information may be a first delay and an estimated time t UPFya and the fifth time point is an expected time point at which the UPF transmits the downlink service packet. For example, the fifth time point=t UPFya + the first delay. In this case, the RAN receives t UPFya Specifically, in step S1001, the SMF obtains t UPFya to the RAN.

[0211] In another manner, the RAN may determine an estimated second downlink scheduling window for the RAN to schedule the downlink service packet based on the estimated time when the downlink service packet arrives at the RAN and the configuration information of the radio resource. Then, the RAN determines a boundary of a third scheduling window based on the second downlink scheduling window, where the third scheduling window is a scheduling window before the second downlink scheduling window. Finally, the RAN determines the first time adjustment information based on the boundary of the third scheduling window.

[0212] For the method of the RAN determining an estimated second downlink scheduling window for the RAN to schedule the downlink service packet based on the estimated time when the downlink service packet arrives at the RAN and the configuration information of the radio resource, and determining the boundary of the third scheduling window based on the second downlink scheduling window, please refer to the description of the SMF determining an estimated second downlink scheduling window for the RAN to schedule the downlink service packet based on the estimated time when the downlink service packet arrives at the RAN and the configuration information of the radio resource in step S601, and determining the boundary of the third scheduling window based on the second downlink scheduling window. Details will not be described again here.

[0213] The RAN may determine the first time adjustment information after determining the boundary of the third scheduling window. For example, the RAN may first determine a first delay based on the boundary of the third scheduling window, and then determine the first time adjustment information based on the first delay. In this regard, please refer to the description of step S601 in which the SMF determines the first delay based on the boundary of the third scheduling window. As another example, the RAN may directly determine the first time adjustment information based on the boundary of the third scheduling window. For example, see FIG. 5. The estimated time t RANyaAssuming that t1 is t1, the RAN can determine, based on the radio resource configuration information and t1, that the estimated second downlink scheduling window for the RAN to schedule the downlink service packet is the downlink scheduling window 2. In this case, the expected time point when the downlink service packet arrives at the RAN is within the third scheduling window, and the third scheduling window is a scheduling window before the second downlink scheduling window, i.e., the downlink scheduling window 1. The first time adjustment information may be a first delay, and the first time adjustment information may be a period T2 (i.e., the first delay) between the upper limit of the downlink scheduling window 1 and t1 and a period T2 between the upper limit of the downlink scheduling window 1 and t1. UPFya or the first time adjustment information may be t RANya , the first delay, and T UPF-RAN It can be the sum of t UPFya and T UPF For the meaning of , see the above explanation. The estimated time t when the downlink service packet arrives at the RAN RANya Assuming that [T3, T4] is t2, the SMF can determine, based on the radio resource configuration information and t2, that the estimated second downlink scheduling window for the RAN to schedule the downlink service packet is the downlink scheduling window 3. In this case, the expected time when the downlink service packet arrives at the RAN is within the third scheduling window, and the third scheduling window is a scheduling window before the second downlink scheduling window, i.e., the uplink scheduling window 1. The first time adjustment information may be a first delay, and the first time adjustment information may be a first delay, which is expressed as [T3, T4] and t UPFya or the first time adjustment information may be [T3, T4], t RANya , and T UPF-RAN where T3 is the period between the lower limit of uplink scheduling window 1 and t2, and T4 is the period between the upper limit of uplink scheduling window 2 and t2.

[0214] The first delay may be a time range, and the first time adjustment information is determined based on the first delay. Thus, the first time adjustment information may be a point in time or may be a time range. If the first delay is a time range, the first time adjustment information may be a time range determined by the RAN based on the first delay. Alternatively, the RAN may determine a time range based on the first delay, and then determine a point in time within the time range as the first time adjustment information based on the time range.

[0215] S1003: The RAN transmits first time adjustment information to the SMF.

[0216] S1004-S1006: The SMF transmits first time adjustment information to the UPF, and the UPF determines a first time point at which the downlink service packet is transmitted based on the first time adjustment information, and transmits the downlink service packet at the first time point.

[0217] Steps S1004 to S1006 are the same as steps S602 to S604. For details, please refer to the explanation of steps S602 to S604. The details will not be explained again here.

[0218] Optionally, the method may further include S1007 and S1008. S1007 and S1008 are the same as S605 and S606. For details, please refer to the description of S605 and S606. The details will not be described again here.

[0219] According to the downlink transmission method provided in the present application, the RAN can determine time adjustment information based on the estimated time when the downlink service packet arrives at the RAN and the configuration information of the radio resource, and can provide the time adjustment information to the SMF. The SMF can adjust the time when the UPF transmits the downlink service packet based on the time adjustment information, so that the UPF can transmit the downlink service packet at the adjusted time. In this way, the time when the downlink service packet arrives at the RAN can be within a first scheduling window of the RAN, and the downlink service packet can be scheduled in a second downlink scheduling window, which is the next scheduling window adjacent to the first scheduling window. This helps to reduce the scheduling waiting delay of scheduling the downlink service by the access network element, and also helps to guarantee the end-to-end delay requirement of the downlink service packet.

[0220] 11 illustrates another downlink transmission method according to the present application. Method 1100 is described below.

[0221] S1101: The SMF sends to the RAN an estimated time when a downlink service packet arrives at the RAN. Correspondingly, the RAN receives from the SMF an estimated time when a downlink service packet arrives at the RAN.

[0222] This step is the same as S1001. Please refer to the above description of S1001. The details will not be described again here.

[0223] S1102: The RAN determines second time adjustment information based on the estimated time when the downlink service packet arrives at the RAN and the configuration information of the radio resource.

[0224] For example, the RAN can determine a first delay based on the estimated time when the downlink service packet arrives at the RAN and the configuration information of the radio resource, and then determine the second time adjustment information based on the first delay. For the method of determining the first delay, please refer to the above description of step S801. The details will not be described again here.

[0225] The RAN determines second time adjustment information based on the first delay, and the second time adjustment information may be the first delay.

[0226] For example, if the second time adjustment information is a first delay, the RAN may instruct the SMF whether the first delay is an advance or a retardation, e.g., if the first delay is determined based on a boundary of the third scheduling window, the first delay is a retardation, or if the first delay is determined based on a boundary of the sixth scheduling window, the first delay is an advance.

[0227] Optionally, the RAN may provide an additional indication for the SMF only if the first delay is a retardation, otherwise the first delay is an advance.

[0228] Optionally, the RAN may instead provide both an advance first delay and a retardation first delay for the SMF to select from.

[0229] The first delay may be a time range, and the second time adjustment information is determined based on the first delay. Thus, the second time adjustment information may be a point in time or may be a time range. If the first delay is a time range, the second time adjustment information may be a time range determined by the RAN based on the first delay. Alternatively, the RAN may determine a time range based on the first delay, and then determine a point in the time range as the second time adjustment information based on the time range. S1103: The RAN transmits the second time adjustment information to the SMF.

[0230] For example, if the second time adjustment information is a first delay, the RAN may instruct the SMF whether the second time adjustment information is an advance or a retardation, for example, if the second time adjustment information is determined based on a boundary of the third scheduling window, the second time adjustment information is a retardation, or if the second time adjustment information is determined based on a boundary of the sixth scheduling window, the second time adjustment information is an advance.

[0231] Optionally, the RAN may provide an additional indication for the SMF only if the second time alignment information is retardation, otherwise the second time alignment information is advance.

[0232] Optionally, the RAN may instead provide both the advance second time alignment information and the retardation second time alignment information for the SMF to select from.

[0233] S1104~S1107: The SMF sends second time adjustment information to the AF, and the AF determines a second time point at which the AS sends a downlink service packet based on the second time adjustment information, and then the AF sends the second time point to the AS, so that the AS can send the downlink service packet at the second time point.

[0234] Steps S1104 to S1107 are the same as steps S802 to S805. For details, please refer to the above description of steps S802 to S805. The details will not be described again here.

[0235] Optionally, the method may further include S1108 and S1109. S1108 and S1109 are the same as S806 and S807. For details, please refer to the above description of S806 and S807. The details will not be described again here.

[0236] According to the downlink transmission method provided in the present application, the RAN can determine time adjustment information based on the estimated time when the downlink service packet arrives at the RAN and the configuration information of the radio resource, and can provide the time adjustment information to the AF using the SMF. The AF can adjust the time when the AS transmits the downlink service packet based on the time adjustment information, so that the AS can transmit the downlink service packet at the adjusted time. In this way, the time when the downlink service packet arrives at the RAN can be within a first scheduling window of the RAN, and the downlink service packet can be scheduled in a second downlink scheduling window, which is the next scheduling window adjacent to the first scheduling window. This helps to reduce the scheduling waiting delay of scheduling the downlink service by the access network element, and also helps to guarantee the end-to-end delay requirement of the downlink service packet.

[0237] 12 illustrates another downlink transmission method according to the present application. Method 1200 is described below.

[0238] S1201: The SMF obtains first information, where the first information includes radio resource configuration information and an estimated time when a downlink service packet arrives at the RAN.

[0239] For the specific content of the radio resource configuration information and how the SMF obtains the radio resource configuration information, please refer to the description of step S601, and the details will not be described again here.

[0240] S1202: The SMF sends the first information to the UPF.

[0241] S1203: The UPF determines a first time point based on the first information.

[0242] The time when the downlink service packet transmitted by the UPF at the first time arrives at the RAN (denoted as the third time) is within the first scheduling window of the RAN, and the next scheduling window adjacent to the first scheduling window is the downlink scheduling window. In other words, since the UPF transmits the downlink service packet at the first time, the downlink service packet can be scheduled in the fourth downlink scheduling window after arriving at the RAN, and the fourth downlink scheduling window is the next scheduling window adjacent to the first scheduling window.

[0243] For example, the UPF may determine first time adjustment information based on the first information, and then determine a first time point based on the first time adjustment information.

[0244] The method of the UPF determining the first time adjustment information based on the first information is the same as the method of the SMF determining the first delay based on the configuration information of the radio resource and the estimated time when the downlink service packet arrives at the RAN in S601. For details, please refer to the description of S601. The details will not be described again here.

[0245] In addition, for how the UPF specifically determines the first time point based on the first time adjustment information, please refer to the description of S603, and the details will not be described again here.

[0246] Optionally, after receiving the downlink packets of the first service, the UPF may buffer the downlink packets of the first service based on the first time alignment information, and the buffering period is a period indicated by the first time alignment information.

[0247] S1204: The UPF transmits a downlink service at a first time point.

[0248] According to the downlink transmission method provided in the present application, the UPF can determine the transmission time of the downlink service packet based on the first information provided by the SMF, so that the time when the downlink service packet arrives at the RAN may be within a first scheduling window of the RAN, and the downlink service packet may be scheduled within a second downlink scheduling window, which is the next scheduling window adjacent to the first scheduling window, which helps to reduce the scheduling waiting delay of scheduling the downlink service by the access network element, and also helps to guarantee the end-to-end delay of the downlink service packet.

[0249] Optionally, the method may further comprise the following steps:

[0250] S1205: The UPF sends the second information to the SMF. Correspondingly, the SMF receives the second information from the UPF.

[0251] The second information is the first time point or the waiting or buffering delay of the downlink service on the UPF.

[0252] S1206: The SMF determines a third time point based on the second information.

[0253] S1207: The SMF sends the third point in time to the RAN, where the third point in time is used by the RAN to schedule the downlink service.

[0254] In S1206, for example, when the second information is a waiting or buffering delay of a downlink service on the UPF, the third time point may be a sum of a time point when a downlink service packet arrives at the UPF, the second information, and a transmission delay from the UPF to the RAN. For example, when the second information is a first time point, the third time point may be a sum of the first time point and a transmission delay from the UPF to the RAN.

[0255] Step S1207 is the same as step S606. Please refer to the description of S606. The details will not be described again here.

[0256] It should be noted that if the SMF obtains the second information in another manner, step S1206 and step S1207 are also applicable and will not be described in detail in this application.

[0257] It should be noted that in the present application, since the downlink service may be a periodic service, the time at which the downlink service packet is transmitted or scheduled may be the start time of transmission of the downlink service packet, and then each network element periodically transmits or schedules the downlink service packet based on that time.

[0258] It should be understood that the solutions of the embodiments of the present application can be appropriately combined for operation, and the explanations or descriptions of terms in the embodiments can be cross-referenced or explained in the embodiments. This is not limited.

[0259] It should be further understood that the sequence numbers of the above processes do not mean the execution order in the embodiments of the present application. The execution order of the processes should be determined based on the functions and internal logic of the processes. The numbers or sequence numbers in the above processes are merely for distinction to facilitate the description, and do not limit the implementation process of the embodiments of the present application in any way.

[0260] The method provided in the embodiment of the present application is described in detail above with reference to Figures 5 to 12. The apparatus provided in the embodiment of the present application is described in detail below with reference to Figures 13 to 15.

[0261] 13 is a schematic block diagram of a communication device according to an embodiment of the present application. As shown in FIG. 13, a communication device 2000 may include a transceiver unit 2010 and a processing unit 2020.

[0262] The transceiver unit 2010 may be configured to transmit information to or receive information from another device, e.g., transmit or receive time adjustment information (e.g., first time adjustment information). The processing unit 1200 may be configured to perform internal processing of the device, e.g., derive a first delay.

[0263] In one implementation, the communication device 2000 corresponds to a session management network element (e.g., SMF) of the above-mentioned method. The communication device 2000 may be a session management network element or a chip configured in a session management network element, and may include a unit configured to perform the operations performed by the session management network element.

[0264] In one example, the communication device 2000 corresponds to a session management network element of the method 600 or 800 .

[0265] The processing unit 2020 is configured to obtain a first delay, the first delay being a period between an expected time when the downlink service packet arrives at the access network element and an estimated time when the downlink service packet arrives at the access network element, the expected time when the downlink service packet arrives at the access network element is within a first scheduling window, and a next scheduling window adjacent to the first scheduling window is a downlink scheduling window. The transceiver unit 2010 is configured to transmit time adjustment information related to the first delay to the first network element, the first network element being a user plane network element or an application network element, the time adjustment information being for determining a first time when the user plane network element transmits the downlink service packet, or being used by an application server to determine a second time when the downlink service packet is transmitted, and a third time when the downlink service packet transmitted by the user plane network element at the first time or transmitted by the application server at the second time arrives at the access network element is within the first scheduling window.

[0266] Optionally, the processing unit 2020 is specifically configured to obtain configuration information of radio resources of the access network element and an estimated time when the downlink service packet arrives at the access network element, and determine a first delay based on the configuration information of the radio resources and the estimated time when the downlink service packet arrives at the access network element.

[0267] Optionally, the processing unit 2020 is specifically configured to: determine, based on the configuration information of radio resources and an estimated time point when the downlink service packet arrives at the access network element, an estimated second downlink scheduling window for the access network element to schedule the downlink service packet; determine, based on the configuration information of radio resources and the second downlink scheduling window, a boundary of a third scheduling window, the third scheduling window being a scheduling window before the second downlink scheduling window, and determine the first delay based on the boundary of the third scheduling window.

[0268] Optionally, the radio resource configuration information includes a slot start time, a slot duration, an uplink-downlink slot configuration, and a scheduling processing delay of the access network element.

[0269] Optionally, the processing unit 2020 is specifically configured to obtain an estimated time when the downlink service packet arrives at the access network element. The transceiver unit 2010 is further configured to send the estimated time when the downlink service packet arrives at the access network element to the access network element, and to receive a first delay from the access network element.

[0270] Optionally, the processing unit 2020 is specifically configured to determine an estimated time when the downlink service packet arrives at the access network element based on a transmission delay from the user plane network element to the access network element and the estimated time when the downlink service packet arrives at the user plane network element, or obtain quality of service QoS information of the downlink service from the policy control network element, and determine an estimated time when the downlink service packet arrives at the access network element based on the QoS information.

[0271] Optionally, when the first network element is a user plane network element, the time adjustment information is the first delay or a fourth time point determined based on the first delay and an estimated time point at which the downlink service packet arrives at the user plane network element.

[0272] Optionally, when the first network element is an application network element, the time adjustment information includes one or more of a first delay, an expected time at which the downlink service packet arrives at the user plane network element determined based on the first delay, and an expected time at which the downlink service packet arrives at the terminal device determined based on the first delay.

[0273] Optionally, the processing unit 2020 is further configured to determine a third time point based on the time adjustment information. The transceiver unit 2010 is further configured to send the third time point to the access network element, where the third time point is used by the access network element to schedule downlink service packets.

[0274] In another example, the communication device 2000 corresponds to a session management network element of the method 1200 .

[0275] Specifically, the processing unit 2020 is configured to obtain first information, the first information including radio resource configuration information and an estimated time when a downlink service packet arrives at an access network element. The transceiver unit 2010 is configured to send the first information to a user plane network element, the first information is for determining a first time when the user plane network element sends a downlink service packet, a third time when the downlink service packet sent at the first time arrives at the access network element is within a first scheduling window of the access network element, and a next scheduling window adjacent to the first scheduling window is a downlink scheduling window.

[0276] Optionally, the radio resource configuration information includes a slot start time, a slot duration, an uplink-downlink slot configuration, and a scheduling processing delay of the access network element.

[0277] Optionally, the transceiver unit 2010 is further configured to receive second information from the user plane network element, the second information being the first time point or a waiting delay of the downlink service packet on the user plane network element. The processing unit 2020 is further configured to determine a third time point based on the second information. The transceiver unit 2010 is further configured to transmit the third time point to the access network element.

[0278] It should be understood that the communication device 2000 may further correspond to the session management network element of the methods 1000 and 1100. For specific operations performed by the communication device 2000, please refer to the description of the session management network element of the methods 1000 and 1100. Details will not be described again here.

[0279] In one implementation, the communication device 2000 corresponds to a user plane network element (e.g., UPF) of the above method. The communication device 2000 may be a user plane network element or a chip configured in a user plane network element, and may include a unit configured to perform the operations performed by the user plane network element.

[0280] In one example, the communication device 2000 corresponds to a user plane network element of the method 600 or 800 .

[0281] Specifically, the transceiver unit 2010 is configured to receive time adjustment information related to a first delay from the session management network element, the first delay being a period between an expected time when the downlink service packet arrives at the access network element and an estimated time when the downlink service packet arrives at the access network element, the expected time when the downlink service packet arrives at the access network element is within a first scheduling window, and a next scheduling window adjacent to the first scheduling window is a downlink scheduling window. The processing unit 2020 is configured to determine a first time when the communication device 2000 transmits the downlink service packet based on the time adjustment information, and a third time when the downlink service packet transmitted at the first time arrives at the access network element is within the first scheduling window.

[0282] Optionally, the time adjustment information is the first delay or a fourth time point determined based on the first delay and an estimated time point at which the downlink service packet will arrive at the communication device 2000 .

[0283] In one example, the communication device 2000 corresponds to a user plane network element of the method 1200 .

[0284] Specifically, the transceiver unit 2010 is configured to receive first information from a session management network element, the first information including radio resource configuration information and an estimated time when a downlink service packet arrives at an access network element. The processing unit 2020 is configured to determine a first time when the downlink service packet is transmitted based on the first information, and a third time when the downlink service packet transmitted at the first time arrives at the access network element is within a first scheduling window of the access network element, and a next scheduling window adjacent to the first scheduling window is a downlink scheduling window.

[0285] Optionally, the radio resource configuration information includes a slot start time, a slot duration, an uplink-downlink slot configuration, and a scheduling processing delay of the access network element.

[0286] Optionally, the processing unit 2020 is specifically configured to determine a first delay based on the first information, the first delay being a period between an expected time when the downlink service packet arrives at the access network element and an estimated time when the downlink service packet arrives at the access network element, and to determine the first time point based on the first delay.

[0287] Optionally, the transceiver unit 2010 is further configured to transmit second information to the session management network element, the second information being the first time point or a waiting delay of the downlink service on the communication device 2000, and the second information being for determining a third time point.

[0288] It should be understood that the communication device 2000 may further correspond to the user plane network element of the methods 1000 and 1100. For specific operations performed by the communication device 2000, please refer to the description of the user plane network element of the methods 1000 and 1100. Details will not be described again here.

[0289] In one implementation, the communication device 2000 corresponds to an application network element (e.g., an AF) of the above-mentioned method. The communication device 2000 may be an application network element or a chip configured in an application network element, and may include a unit configured to perform the work performed by the application network element.

[0290] In one example, the communication device 2000 corresponds to an application network element of the method 800 .

[0291] Specifically, the transceiver unit 2010 is configured to receive time adjustment information related to a first delay from the session management network element, the first delay being a period between an expected time when the downlink service packet arrives at the access network element and an estimated time when the downlink service packet arrives at the access network element, the expected time when the downlink service packet arrives at the access network element is within a first scheduling window, and a next scheduling window adjacent to the first scheduling window is a downlink scheduling window. The processing unit 2020 is configured to determine a second time when the application server transmits the downlink service packet based on the time adjustment information, and a third time when the downlink service packet transmitted at the second time arrives at the access network element is within the first scheduling window.

[0292] Optionally, the time adjustment information includes one or more of a first delay, an expected time at which the downlink service packet arrives at the user plane network element, the expected time being determined based on the first delay, and an expected time at which the downlink service packet arrives at the terminal device, the expected time being determined based on the first delay.

[0293] It should be understood that the communication device 2000 may further correspond to the application network element of the method 1100. For specific operations performed by the communication device 2000, please refer to the description of the application network element of the method 1100. Details will not be described again here.

[0294] In one implementation, the communication device 2000 corresponds to an access network element (e.g., a RAN) of the above-mentioned method. The communication device 2000 may be an access network element or a chip configured in an access network element, and may include units configured to perform the operations performed by the access network element.

[0295] In one example, the communication device 2000 corresponds to an access network element of the method 600 or 800 .

[0296] Specifically, the transceiver unit 2010 is configured to receive from the session management network element an estimated time when the downlink service packet arrives at the communication device 2000. The processing unit 2020 is configured to determine a first delay based on the estimated time when the downlink service packet arrives at the communication device 2000, the first delay being a period between a time when the downlink service packet expected by the communication device 2000 arrives at the communication device 2000 and the estimated time when the downlink service packet arrives at the communication device 2000, the time when the downlink service packet expected by the communication device 2000 arrives at the communication device 2000 is within a first scheduling window, and a next scheduling window adjacent to the first scheduling window is a downlink scheduling window. The transceiver unit 2010 is further configured to transmit the first delay to the session management network element, and the first delay is used by the session management network element to adjust a time when the user plane network element transmits the downlink service packet and / or a time when the application server transmits the downlink service packet.

[0297] Optionally, the processing unit 2020 is specifically configured to determine the first delay based on an estimated time when the downlink service packet arrives at the communication device 2000 and configuration information of the radio resources of the communication device 2000 .

[0298] Optionally, the radio resource configuration information includes the slot start time, slot duration, uplink-downlink slot configuration, and scheduling process delay of the communications device 2000.

[0299] Optionally, the processing unit 2020 is specifically configured to determine an estimated second downlink scheduling window for the communication device 2000 to schedule a downlink service based on the configuration information of the radio resources and an estimated time when the downlink service packet arrives at the communication device 2000, determine a boundary of a third scheduling window based on the configuration information of the radio resources and the second downlink scheduling window, the third scheduling window being a scheduling window before the second downlink scheduling window, and determine the first delay based on the boundary of the third scheduling window.

[0300] In one example, the communications device 2000 corresponds to an access network element of the method 1000 or 1100 .

[0301] Specifically, the transceiver unit 2010 is configured to receive from the session management network element an estimated time when the downlink service packet arrives at the communication device 2000. The processing unit 2020 is configured to determine time adjustment information based on the estimated time when the downlink service packet arrives at the communication device 2000 and the configuration information of the radio resource. The transceiver unit 2010 is further configured to send the time adjustment information to the session management network element, where the time adjustment information is used by the session management network element to adjust the time when the user plane network element sends the downlink service packet and / or the time when the application server sends the downlink service packet.

[0302] Optionally, the processing unit 2020 is specifically configured to determine a first delay based on an estimated time when the downlink service packet will arrive at the communication device 2000 and configuration information of radio resources, the first delay being a period between the time when the downlink service packet expected by the communication device 2000 will arrive at the communication device 2000 and the estimated time when the downlink service packet will arrive at the communication device 2000, the time when the downlink service packet expected by the communication device 2000 will arrive at the communication device 2000 is within a first scheduling window, the next scheduling window adjacent to the first scheduling window is a downlink scheduling window, and determine time adjustment information based on the first delay.

[0303] Optionally, the processing unit 2020 is specifically configured to determine an estimated second downlink scheduling window for the communication device 2000 to schedule the downlink service packet based on an estimated time point when the downlink service packet arrives at the communication device 2000 and radio resource configuration information, determine a boundary of a third scheduling window based on the second downlink scheduling window, the third scheduling window being a scheduling window before the second downlink scheduling window, and determine time adjustment information based on the boundary of the third scheduling window.

[0304] Optionally, the radio resource configuration information includes the slot start time, slot duration, uplink-downlink slot configuration, and scheduling process delay of the communications device 2000.

[0305] It should be understood that the communication device 2000 may further correspond to an access network element of the method 1200. For specific operations performed by the communication device 2000, please refer to the description of the access network element of the method 1200. Details will not be described again here.

[0306] It should be understood that the specific processes by which the units perform the above corresponding steps have been described in detail in the above method embodiments, and for the sake of brevity, the details will not be described again here.

[0307] It should be further understood that, when the communication device 2000 corresponds to a session management network element, an application network element, a user plane network element, or an access network element, the transceiver unit 2010 of the communication device 2000 may correspond to the communication interface 3200 of the communication device 3000 shown in Figure 14, and the processing unit 2020 of the communication device 2000 may correspond to the processor 3100 of the communication device 3000 shown in Figure 14. When the communication device 2000 corresponds to an access network element, the transceiver unit 2010 of the communication device 2000 may further correspond to the transceiver 4200 of the network device 4000 shown in Figure 15, and the processing unit 2020 of the communication device 2000 may further correspond to the processor 4100 of the network device 4000 shown in Figure 15.

[0308] 14 is a schematic block diagram of another communication device 3000 according to the present application. Any network element in the above-mentioned method embodiment, such as a session management network element, an application network element, a user plane network element, or an access network element, may be implemented by the communication device shown in FIG.

[0309] It is to be understood that the communications apparatus 3000 may be a physical device, a component of a physical device (eg, an integrated circuit or chip), or a functional module within a physical device.

[0310] As shown in FIG. 14, the communication device 3000 includes one or more processors 3100. The processor 3100 can store executable instructions for executing the method of the embodiment of the present application. Optionally, the processor 3100 can call the communication interface 3200 to perform the receiving and transmitting functions. The communication interface 3200 can be a logical interface or a physical interface. This is not limited. For example, the communication interface 3200 can be a transceiver circuit, an interface circuit, a transceiver, or a transceiver circuit configured to perform the transmitting and receiving functions. The transmitting and receiving functions of the communication interface 3200 can be separate or integrated. The transceiver circuit or the interface circuit can be configured to read and write code / data, or the transceiver circuit or the interface circuit can be configured to transmit or forward signals.

[0311] Optionally, the communication device 3000 may further include a memory 3300. The specific location of the memory 3300 is not specifically limited in this embodiment of the present application. The memory 3300 may be integrated into the processor 3100 or may be independent from the processor 3100. If the communication device 3000 does not include a memory, the communication device 3000 only needs to have a processing function, and the memory may be located elsewhere (e.g., a cloud system).

[0312] The processor 3100, memory 3300, and communication interface 3200 communicate with each other through internal connection paths to transfer control and / or data signals.

[0313] Although not shown, it will be understood that the communication device 3000 may further include other devices, such as an input device, an output device, or a battery.

[0314] Optionally, in some embodiments, the memory 3300 may store execution instructions for performing the method of the embodiments of the present application. The processor 3100 can execute the instructions stored in the memory 3300 and cooperate with other hardware (e.g., the communication interface 3200) to complete the steps performed in the following method. For specific work processes and beneficial effects, please refer to the description of the above method embodiments.

[0315] The methods disclosed in the embodiments of the present application may be applied to or implemented by the memory 3300. The memory 3300 may be an integrated circuit chip having signal processing capabilities. In the course of implementation, the steps of the methods may be executed through hardware integrated logic circuitry in a processor or by using instructions in the form of software. The aforementioned processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or another programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. The processor may implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor, etc. The steps of the methods disclosed with reference to the embodiments of the present application may be directly executed and achieved by using a hardware decode processor, or may be executed and achieved by using a combination of hardware and software modules in the decode processor. The software module may be located in a storage medium well known in the art, such as a random access memory (RAM), a flash memory, a read-only memory (ROM), a programmable read-only memory, an electrically erasable programmable memory, or a register. The storage medium is located in the memory, and the processor reads the instructions in the memory and cooperates with the processor hardware to complete the steps of the aforementioned method.

[0316] It will be appreciated that the memory 3300 may be volatile or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory may be a read-only memory ROM, a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory RAM, which functions as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchlink dynamic random access memory (SLDRAM), and direct rambus random access memory (DR RAM). It should be noted that memory in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0317] FIG. 15 is a schematic diagram of a structure of a network device according to an embodiment of the present application. For example, FIG. 15 may be a schematic diagram of a structure of a base station. The network device 4000 can be used in the system shown in FIG. 1 or FIG. 2 and perform the function of an access network element in the embodiment of the method described above. As shown in FIG. 15, the network device 4000 may include one or more radio frequency units, such as a remote radio unit (RRU) 4100 and one or more baseband units (BBUs) (also referred to as distributed units (DUs)) 4200. The RRU 4100 may also be referred to as a transceiver unit or a communication unit, and corresponds to the transceiver unit 2010 in FIG. 13. Optionally, the transceiver unit 4100 may also be referred to as a transceiver, a transceiver circuit, etc., and may include at least one antenna 4101 and a radio frequency unit 4102. Optionally, the transceiver unit 4100 may include a receiving unit and a transmitting unit. The receiving unit may correspond to a receiver (or referred to as a receiving circuit), and the transmitting unit may correspond to a transmitter (or referred to as a transmitting circuit). The RRU4100 is mainly configured to transmit and receive radio frequency signals, and perform conversion between radio frequency signals and baseband signals. The BBU4200 is mainly configured to perform baseband processing, control network devices, and so on. The RRU4100 and the BBU4200 may be physically co-located or physically separate, i.e., may be a distributed base station.

[0318] The BBU 4200 is a control center of the network device, which may also be called a processing unit, and may correspond to the processing unit 2020 of Fig. 13, and is mainly configured to perform baseband processing functions, such as channel coding, multiplexing, modulation, or spreading. For example, the BBU (processing unit) may be configured to control the network device to perform work procedures related to the access network device in the embodiment of the method described above.

[0319] In one example, the BBU 4200 may include one or more boards, and the multiple boards may jointly support a radio access network having a single access standard (e.g., an LTE network) or separately support radio access networks having separate access standards (e.g., an LTE network, a 5G network, or another network). The BBU 4200 further includes a memory 4201 and a processor 4202. The memory 4201 is configured to store necessary instructions and data. The processor 4202 is configured to control the network device to perform necessary operations, for example, to control the network device to perform work procedures related to the access network device in the embodiment of the method described above. The memory 4201 and the processor 4202 may serve one or more boards. In other words, the memory and the processor may be separately located on each board. Alternatively, the multiple boards may share the same memory and the same processor. In addition, necessary circuits may be further located on each board.

[0320] It should be understood that the network device 4000 shown in Fig. 15 can implement the process related to the access network device in the above-mentioned method embodiment. The work or function of the module in the network device 4000 is respectively intended to implement the corresponding procedure in the above-mentioned method embodiment. For details, please refer to the description of the above-mentioned method embodiment. In order to avoid repetition, detailed description will be omitted here as appropriate.

[0321] The BBU4200 may be configured to perform the operations implemented in the access network device in the aforementioned method embodiments, and the RRU4100 may be configured to perform the operations of sending to or receiving from the terminal device by the access network device in the aforementioned method embodiments. For details, please refer to the description of the aforementioned method embodiments. Details will not be described again here.

[0322] The present application further provides a computer program product, the computer program product including computer program code, which, when executed on a computer, enables the computer to perform a method on a session management network element side, an application network element side, a user plane network element side, or an access network element side in any one of the embodiments of the method described above.

[0323] The present application further provides a computer-readable medium, which stores program code, which, when executed on a computer, enables the computer to perform a method on a session management network element side, an application network element side, a user plane network element side, or an access network element side in the above-mentioned method embodiments.

[0324] The present application further provides a system including any one or more of the above-mentioned session management network element, application network element, user plane network element, and access network element. Optionally, the system may further include the above-mentioned terminal device.

[0325] An embodiment of the present application further provides a processing device, including a processor and an interface, the processor being configured to execute the communication method in any one of the embodiments of the method described above.

[0326] It should be understood that the processing device may be a chip. For example, the processing device may be a field programmable gate array (FPGA), a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), another programmable logic device, a discrete gate, a transistor logic device, or a discrete hardware component, a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a micro controller unit (MCU), or a programmable logic device (PLD) or another integrated chip. The processing device can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor, etc. The steps of the methods disclosed with reference to the embodiments of the present application may be directly performed and achieved by using a hardware decoding processor, or may be performed and achieved by using a combination of hardware and software modules in the decoding processor. The software modules may be located in any storage medium mature in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, or a register.The storage medium is located in the memory, and the processor reads the information in the memory and cooperates with the processor's hardware to complete the steps of the above-mentioned method.

[0327] It will be understood that the memory of the present embodiment of the present application may be volatile or non-volatile memory, or may include volatile and non-volatile memory. The non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory may be random access memory (RAM) used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchlink dynamic random access memory (SLDRAM), and direct rambus random access memory (DR RAM). It should be noted that memory in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0328] All or part of the above-mentioned embodiments may be implemented by using software, hardware, firmware, or any combination thereof. If software is for implementing the embodiments, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded into a computer and executed, the procedures or functions according to the embodiments of the present application are generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center in a wired manner (e.g., coaxial cable, optical fiber, or digital subscriber line (DSL)) or in a wireless manner (e.g., infrared, radio wave, or microwave). A computer-readable storage medium may be any available medium accessible by a computer, or a data storage device integrating one or more available media, such as a server or a data center. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk drive, or a magnetic tape), an optical medium (e.g., a digital video disc (DVD)), or a semiconductor medium (e.g., a solid state disc (SSD)), etc.

[0329] The network device and the terminal device in the above-mentioned apparatus embodiments fully correspond to the network device and the terminal device in the method embodiments. The corresponding modules or units perform the corresponding steps. For example, a communication unit (transceiver) performs the receiving step or the transmitting step of the method embodiments, and a processing unit (processor) can perform steps other than the transmitting step and the receiving step. For the functions of specific units, please refer to the corresponding method embodiments. There may be one or more processors.

[0330] As used herein, terms such as "component," "module," and "system" refer to computer-related entities, hardware, firmware, a combination of hardware and software, software, or software being executed. For example, a component may be, but is not limited to, a process running on a processor, a processor, an object, an executable file, a thread of execution, a program, or a computer. As illustrated using the figures, both a computing device and an application running on a computing device may be a component. One or more components may reside within a process or thread of execution, and a component may be located on one computer or distributed across two or more computers. In addition, these components may be executed by various computer-readable media that store various data structures. For example, components may communicate by using local or remote processes based on signals that have one or more data packets (e.g., data from two components communicating with another component in a local system, in a distributed system, or across a network such as the Internet that communicates with another system using signals).

[0331] It should be understood that the term "embodiment" as used throughout this specification means that a particular feature, structure, or characteristic associated with this embodiment is included in at least one embodiment of the present application. Thus, embodiments throughout this specification do not necessarily refer to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0332] It should be understood that in the embodiments of the present application, the numbers such as "first" and "second" are merely for distinguishing different objects, for example, for distinguishing different network devices, and do not limit the scope of the embodiments of the present application. The embodiments of the present application are not limited thereto.

[0333] It should be further understood that in this application, both "when" and "if" mean that the network element executes the corresponding processing in an objective situation, but do not limit the time, do not require the network element to have a decision-making operation during implementation, and do not imply any other limitation.

[0334] It should be further understood that, in this application, "at least one" means one or more, and "plurality" means two or more.

[0335] It should be further understood that in the embodiments of the present application, "B corresponding to A" indicates that B is associated with A, and B can be determined based on A. However, it should be further understood that determining B based on A does not mean that B is determined based only on A, i.e., B can be determined based on A and / or other information.

[0336] It should also be understood that the term "and / or" in this specification describes only the relational relationship between related objects and indicates that three relations may exist. For example, A and / or B can represent the following three cases: only A is present, both A and B are present, and only B is present. In addition, the character " / " in this specification generally indicates an "or" relationship between related objects.

[0337] Unless otherwise stated, expressions used in this application similar to the expression "the item includes any one or more of A, B, and C" usually mean that the item can be any one of the following: A; B; C; A and B; A and C; B and C; A, B, and C; A and A; A, A, and A; A, A, and B; A, A, and C; A, B, and B; A, C, and C; B and B; B, B and B; B, B and C; C and C; C, C, and C; and other combinations of A, B, and C. In the above description, three elements A, B, and C are used as an example to describe the optional case of the item. If the expression is "the item includes at least any one of A, B, ..., and X", in other words, if more elements are included in the expression, the case in which the item is applicable can also be obtained according to the above rules.

[0338] It is understood that in the embodiments of the present application, the terminal device and / or the network device can perform some or all of the steps of the embodiments of the present application. These steps or operations are merely examples. In the embodiments of the present application, other operations or variations of various operations may be further performed. In addition, the steps may be performed in an order different from the order presented in the embodiments of the present application, and some operations of the embodiments of the present application may not be performed.

[0339] Those skilled in the art can realize that, in combination with the examples described in the embodiments disclosed herein, the units and algorithm steps can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether a function is performed by hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can implement the described functions using various methods for each specific application, but the implementation should not be considered to go beyond the scope of this application.

[0340] It will be clearly understood by those skilled in the art that for the purpose of convenience of description, the detailed working processes of the aforementioned systems, devices and units should be referred to the corresponding processes of the aforementioned method embodiments, and the details will not be described again here.

[0341] In some embodiments provided in the present application, it should be understood that the disclosed system, device, and method may be implemented in other ways. For example, the above-mentioned device embodiment is merely an example. For example, the division into units is merely a logical functional division, and may be other divisions in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not implemented. In addition, the shown or discussed mutual couplings or direct couplings or communication connections may be implemented using some interfaces. Indirect couplings or communication connections between devices or units may be implemented in electrical, mechanical, or other forms.

[0342] The units described as separate parts may or may not be physically separate, and the parts shown as units may or may not be physical units, and may be located in one place or distributed among multiple network units. Some or all of the units may be selected based on actual requirements to achieve the objectives of the solutions of the embodiments.

[0343] In addition, the functional units of the embodiments of the present application may be integrated into one processing unit, and each unit may exist physically alone, or two or more units may be integrated into one unit.

[0344] When a function is implemented in the form of a software functional unit and sold or used as an independent product, the function may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application may essentially, or a part that contributes to the prior art, or a part of the technical solution may be implemented in the form of a software product. The computer software product includes some instructions that are stored in a storage medium and instruct a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method of the embodiments of the present application. The aforementioned storage medium includes any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory ROM, a random access memory RAM, a magnetic disk, or an optical disk.

[0345] The above description is merely a specific implementation of the present application, and the protection scope of the present application is not limited thereto. Any variations or replacements that are easily conceived by those skilled in the art within the technical scope disclosed in this application shall fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims. [Explanation of symbols]

[0346] 100 Systems 101 Terminal device, UE 102 Access network elements, (wireless) access networks 103 User Plane Network Element, User Plane Function 104 Data Network 105 Access and Mobility Management Network Elements, Access and Mobility Management Functions 106 Session Management Network Element, Session Management Function 107 Policy Control Network Element, Policy Control Function 108 Application Network Elements, Application Functions 109 Unified Data Management Network Elements, Unified Data Management 110 Network Exposure Network Element, Network Exposure Function 1200 Processing Units 2000 Communication Equipment 2010 Transceiver Unit 2020 Processing Unit 3000 Communication Equipment 3100 Processor 3200 Communication Interface 3300 Memory 4000 Network Devices 4100 Processor, Remote Radio Unit, Transceiver Unit 4101 Antenna 4102 Radio Frequency Unit 4200 Transceiver, Baseband Unit 4201 Memory 4202 processor

Claims

1. obtaining, by a session management network element, a first delay, the first delay being a period between an expected time when a downlink service packet arrives at an access network element and an estimated time when the downlink service packet arrives at the access network element, the estimated time when the downlink service packet arrives at the access network element being determined based on a Policy of Charging and Control (PCC) rule from a policy control network element, the expected time when the downlink service packet arrives at the access network element being within a first scheduling window, and a next scheduling window adjacent to the first scheduling window being a downlink scheduling window; sending, by the session management network element, time adjustment information related to the first delay to a first network element, the first network element being an application network element, the time adjustment information being used by the application network element to determine a second time point at which the downlink service packet is transmitted, and a third time point at which the downlink service packet transmitted at the second time point arrives at the access network element is within the first scheduling window; A downlink transmission method comprising:

2. The step of obtaining a first delay by a session management network element includes: obtaining, by the session management network element, configuration information of radio resources of the access network element and the estimated time when the downlink service packet arrives at the access network element; determining, by the session management network element, the first delay based on the configuration information of the radio resources and the estimated time when the downlink service packet arrives at the access network element; 2. The method of claim 1, comprising:

3. The step of determining, by the session management network element, the first delay based on the configuration information of the radio resource and the estimated time when the downlink service packet arrives at the access network element, comprises: determining, by the session management network element, a second downlink scheduling window for the access network element to schedule the downlink service packet based on the configuration information of the radio resource and the estimated time when the downlink service packet arrives at the access network element; determining, by the session management network element, a boundary of a third scheduling window based on the configuration information of the radio resources and the second downlink scheduling window, the third scheduling window being a scheduling window preceding the second downlink scheduling window; determining, by the session management network element, the first delay based on the boundary of the third scheduling window; 3. The method of claim 2, comprising:

4. The method according to claim 2 or 3, wherein the configuration information of the radio resources includes: a slot start time, a slot duration, an uplink-downlink slot configuration, and a scheduling processing delay of the access network element.

5. The step of obtaining a first delay by a session management network element includes: obtaining, by the session management network element, the estimated time when the downlink service packet arrives at the access network element; sending, by the session management network element, to the access network element, the estimated time when the downlink service packet will arrive at the access network element; receiving, by the session management network element, the first delay from the access network element; 2. The method of claim 1, comprising:

6. The step of obtaining, by the session management network element, the estimated time point at which the downlink service packet arrives at the access network element, comprises: determining, by the session management network element, the estimated time at which the downlink service packet will arrive at the access network element based on a transmission delay from a user plane network element to the access network element and the estimated time at which the downlink service packet will arrive at the user plane network element.

6. The method of claim 5, comprising:

7. The method comprises: receiving, by the session management network element, the PCC rule from the policy control network element, the PCC rule including the estimated time when the downlink service packet will arrive at the user plane network element; 7. The method of claim 6, further comprising:

8. 8. The method according to claim 1, wherein the time adjustment information includes one or more of the first delay, an expected time at which the downlink service packet arrives at a user plane network element, the expected time being determined based on the first delay, and an expected time at which the downlink service packet arrives at a terminal device, the expected time being determined based on the first delay.

9. The method comprises: determining, by the session management network element, the third time point based on the time adjustment information; sending, by the session management network element, the third time point to the access network element, the third time point being used by the access network element to schedule the downlink service packets; 9. The method of claim 1, further comprising:

10. receiving, by the application network element, time adjustment information related to a first delay from a session management network element, the first delay being a period between an expected time when a downlink service packet arrives at an access network element and an estimated time when the downlink service packet arrives at the access network element, the estimated time when the downlink service packet arrives at the access network element being determined based on a Policy of Charging and Control (PCC) rule from a Policy Control network element, the expected time when the downlink service packet arrives at the access network element being within a first scheduling window, and a next scheduling window adjacent to the first scheduling window being a downlink scheduling window; determining, by the application network element, a second time point at which the downlink service packet is transmitted based on the time adjustment information, wherein a third time point at which the downlink service packet transmitted at the second time point arrives at the access network element is within a first scheduling window; A downlink transmission method comprising:

11. 11. The method of claim 10, wherein the time adjustment information includes one or more of the first delay, an expected time at which the downlink service packet arrives at a user plane network element, the expected time being determined based on the first delay, and an expected time at which the downlink service packet arrives at a terminal device, the expected time being determined based on the first delay.

12. receiving, by the access network element, from a session management network element, an estimated time when a downlink service packet arrives at the access network element, the estimated time when the downlink service packet arrives at the access network element being determined based on a Policy of Charging and Control rule (PCC rule) from a policy control network element; determining, by the access network element, a first delay based on the estimated time when the downlink service packet will arrive at the access network element, the first delay being a period between a time when the downlink service packet is expected by the access network element to arrive at the access network element and the estimated time when the downlink service packet will arrive at the access network element, the time when the downlink service packet is expected by the access network element to arrive at the access network element is within a first scheduling window, and a next scheduling window adjacent to the first scheduling window is a downlink scheduling window; sending the first delay by the access network element to the session management network element, the first delay being provided by the session management network element to an application network element to adjust a time at which the downlink service packet is transmitted; A downlink transmission method comprising:

13. The step of determining, by the access network element, a first delay based on the estimated time point at which the downlink service packet arrives at the access network element, comprises: determining, by the access network element, the first delay based on the estimated time when the downlink service packet arrives at the access network element and configuration information of radio resources of the access network element; 13. The method of claim 12, comprising:

14. The step of determining, by the access network element, the first delay based on the estimated time when the downlink service packet arrives at the access network element and configuration information of radio resources of the access network element, comprises: determining, by the access network element, a second downlink scheduling window for the access network element to schedule the downlink service packet based on the configuration information of the radio resource and the estimated time point when the downlink service packet arrives at the access network element; determining, by the access network element, a boundary of a third scheduling window based on the configuration information of the radio resources and the second downlink scheduling window, the third scheduling window being a scheduling window preceding the second downlink scheduling window; determining, by the access network element, the first delay based on the boundary of the third scheduling window; 14. The method of claim 13, comprising:

15. A communications device, the device being configured to perform a method according to any one of claims 1 to 9, claims 10 or 11, or any one of claims 12 to 14.

16. receiving, by the access network element, from a session management network element, an estimated time when a downlink service packet arrives at the access network element, the estimated time when the downlink service packet arrives at the access network element being determined based on a Policy of Charging and Control rule (PCC rule) from a policy control network element; determining, by the access network element, a first delay based on the estimated time point at which the downlink service packet will arrive at the access network element, the first delay being a period between a time point at which the downlink service packet is expected by the access network element to arrive at the access network element and the estimated time point at which the downlink service packet will arrive at the access network element, the time point at which the downlink service packet is expected by the access network element to arrive at the access network element being within a first scheduling window, and a next scheduling window adjacent to the first scheduling window being a downlink scheduling window; transmitting, by the access network element, the first delay to the session management network element; obtaining, by the session management network element, the first delay; sending, by the session management network element, time adjustment information related to the first delay to a first network element, the first network element being an application network element, the time adjustment information being used by the application network element to determine a second time point at which the downlink service packet is transmitted, and a third time point at which the downlink service packet transmitted at the second time point arrives at the access network element is within the first scheduling window; A downlink transmission method comprising:

17. A system comprising: a session management network element configured to perform the method according to any one of claims 1 to 9; and an access network element configured to perform the method according to any one of claims 12 to 14.

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