Downlink transmission method and communication device

Abstract

The present application provides a method and communication device for downlink transmission, wherein a session management network element obtains the time length between the time when an expected downlink service message arrives at an access network element and the time when the downlink service message is expected to arrive at the access network element, that is, a first delay, and the time when the expected downlink service message arrives at the access network element is within a first scheduling window, and the next scheduling window adjacent to the first scheduling window is a downlink scheduling window, and then the session management network element sends time adjustment information related to the first delay to a user plane network element or an application network element, and the time adjustment information is used for the user plane network element to determine the first time to send the downlink service message or the application server to determine the second time to send the downlink service message, and the time when the downlink service message sent by the user plane network element at the first time or the application server at the second time 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

[0001] The present application relates to the field of communications, and more specifically, to a downlink transmission method and a communication device. Background Art

[0002] In the communication system, taking into account the particularity of the access network element scheduling, such as the uplink and downlink ratio, the scheduling protection window between time slots, etc., the downlink service message may introduce a scheduling delay on the access network element side. For example, if the time when a downlink service message arrives at the access network element is within a scheduling window of the access network element, it is necessary to wait until at least the arrival of the most recent downlink scheduling window before the downlink service message can be scheduled. If the most recent scheduling window is an uplink scheduling window instead of a downlink scheduling window, the scheduling waiting delay introduced on the access network element side is at least greater than the length of a scheduling window. For another example, if the time when a downlink service message arrives at the access network element is within the processing window of the access network element, it is necessary to wait until at least the arrival of the next downlink scheduling window before the downlink service message can be scheduled. The scheduling waiting delay introduced on the access network element side may cause the end-to-end delay of the downlink service message to be unable to be guaranteed. Summary of the invention

[0003] The present application provides a method and a communication device for downlink transmission, which can reduce the scheduling delay on the access network element side, and is conducive to ensuring the end-to-end delay requirement of downlink service messages.

[0004] In a first aspect, a method for downlink transmission is provided, including: a session management network element acquires a first delay, where the first delay is the time length between a time when a downlink service message is expected to arrive at the access network element and a time when the downlink service message is expected to arrive at the access network element, wherein the time when the expected downlink service message arrives at the access network element is within a first scheduling window, wherein a next scheduling window adjacent to the first scheduling window is a downlink scheduling window; the session management network element sends time adjustment information related to the first delay to a first network element, where the first network element is a user plane network element or an application network element, and the time adjustment information is used to determine a first time when the user plane network element sends the downlink service message, or is used by an application server to determine a second time when the downlink service message is sent, wherein a third time when the downlink service message sent by the user plane network element at the first time or by the application server at the second time arrives at the access network element is within the first scheduling window.

[0005] According to the downlink transmission method provided by the present application, the application server or user plane network element can adjust the time of sending the downlink service message according to the time adjustment information provided by the session management network element, so that when the downlink service message is sent at the adjusted sending time, the time when the downlink service message arrives at the access network element can be located within the first scheduling window of the access network element, and the downlink service message can be scheduled in the second downlink scheduling window, and the second downlink scheduling window is the next scheduling window adjacent to the first scheduling window. In this way, it is beneficial to reduce the scheduling waiting delay of the access network element scheduling the downlink service, and further to ensure the end-to-end delay of the downlink service message. Furthermore, under normal circumstances, an application server or a user-plane network element will receive messages for multiple downlink services for multiple access network network elements. This method enables the application server or the user-plane network element to cache the downlink service messages while giving priority to other downlink service messages, making rational use of resources, alleviating and avoiding processing conflicts between downlink service messages sent to different access network network element nodes, and improving the processing efficiency of downlink service messages in the application server or the user-plane network element, which is beneficial to ensuring the end-to-end delay requirements of the downlink service message and other downlink service messages.

[0006] In combination with the first aspect, in certain implementations of the first aspect, the session management network element obtains the first delay, including: the session management network element obtains the configuration information of the wireless resources of the access network network element and the time when the downlink service message is expected to arrive at the access network network element; the session management network element determines the first delay based on the configuration information of the wireless resources and the time when the downlink service message is expected to arrive at the access network element.

[0007] Optionally, the access network element may report the configuration information of the wireless resources and the corresponding cell identifier (ID) to the mobility management element (e.g., access and mobility management function (AMF)) during the NG setup process, and the session management element may obtain the configuration information of the wireless resources and the cell ID from the mobility management element. The NG setup process may be referred to as the N2 setup process, and the interface between the access network element and the mobility management element is referred to as the NG interface.

[0008] Alternatively, during the terminal device registration process, the access network element may carry the cell ID and the configuration information of the wireless resources, or carry the cell ID, the terminal device ID and the configuration information of the wireless resources when forwarding the registration request to the mobility management element. Then, the session management element may obtain the configuration information of the wireless resources from the mobility management element.

[0009] Alternatively, when a session is established, the access network element may send a cell ID and corresponding wireless resource configuration information to the session management element via an N2 message, or send a cell ID, a terminal device ID and corresponding wireless resource configuration information.

[0010] Alternatively, the access network element may provide the configuration information of the wireless resources corresponding to the cell to the Network Data Analytics Function (NWDAF), and the session management element may obtain the configuration information of the wireless resources and the corresponding cell ID from the NWDAF.

[0011] In combination with the first aspect, in some implementations of the first aspect, the session management network element determines the first delay according to the configuration information of the wireless resources and the time when the downlink service is expected to arrive at the access network element, including: the session management network element determines a second downlink scheduling window in which the access network element is expected to schedule the downlink service message according to the configuration information of the wireless resources and the time when the downlink service message is expected to arrive at the access network element; the session management network element determines a boundary of a third scheduling window according to the configuration information of the wireless resources and the second downlink scheduling window, and the third scheduling window is a previous scheduling window of the second downlink scheduling window; the session management network element determines the first delay according to the boundary of the third scheduling window.

[0012] In combination with the first aspect, in certain implementations of the first aspect, the configuration information of the wireless resources includes a time slot start time, a time slot duration, an uplink and downlink time slot ratio, and a scheduling processing delay of the access network element.

[0013] In combination with the first aspect, in certain implementations of the first aspect, the session management network element obtains the first delay, including: the session management network element obtains the time when the downlink service message is expected to arrive at the access network network element; the session management network element sends the time when the downlink service message is expected to arrive at the access network network element to the access network element; the session management network element receives the first delay from the access network element.

[0014] In combination with the first aspect, in certain implementations of the first aspect, the session management network element obtains the time when the downlink service message is expected to arrive at the access network element, including: the session management network element determines the time when the downlink service message is expected to arrive at the access network element according to the transmission delay from the user plane network element to the access network element and the time when the downlink service message is expected to arrive at the user plane network element; or, the session management network element obtains the quality of service (QoS) information of the downlink service from the policy control network element, and determines the time when the downlink service message is expected to arrive at the access network element according to the QoS information.

[0015] In combination with the first aspect, in certain implementations of the first aspect, when the first network element is the user plane network element, the time adjustment information is the first delay or a fourth time moment determined based on the first delay and the time moment when the downlink service message is expected to arrive at the user plane network element.

[0016] In combination with the first aspect, in certain implementations of the first aspect, when the first network element is the application network element, the time adjustment information includes one or more of the following: the first delay, the time when the expected downlink service message arrives at the user-plane network element based on the first delay, and the time when the expected downlink service message arrives at the terminal device based on the first delay.

[0017] In combination with the first aspect, in certain implementations of the first aspect, the method further includes: the session management network element determines the third moment based on the time adjustment information; the session management network element sends the third moment to the access network network element, and the third moment is used by the access network network element to schedule the downlink service message.

[0018] For example, the access network element can implement semi-static scheduling of the downlink service message according to the period of the downlink service message and the time when the downlink service message arrives at the access network element, that is, allocate the same time-frequency resources that can be periodically reused to the downlink service message at one time, thereby reducing the end-to-end transmission delay of the downlink service message and saving control plane resources.

[0019] In a second aspect, a method for downlink transmission is provided, characterized in that it includes: a user plane network element receives time adjustment information related to a first delay from a session management network element, the first delay being the time length between a moment when an expected downlink service message arrives at the access network element and a moment when the downlink service message is expected to arrive at the access network element, wherein the moment when the expected downlink service message arrives at the access network element is within a first scheduling window, wherein a next scheduling window adjacent to the first scheduling window is a downlink scheduling window; the user plane network element determines, based on the time adjustment information, a first moment when the user plane network element sends the downlink service message, wherein a third moment when the downlink service message sent at the first moment arrives at the access network element is within the first scheduling window.

[0020] According to the downlink transmission method provided by the present application, the user plane network element can adjust the time of sending the downlink service message according to the time adjustment information provided by the session management network element, so that when the downlink service message is sent at the adjusted sending time, the time when the downlink service message arrives at the access network element can be located in the first scheduling window of the access network element, and the downlink service message can be scheduled in the second downlink scheduling window, and the second downlink scheduling window is the next scheduling window adjacent to the first scheduling window. In this way, it is beneficial to reduce the scheduling waiting delay of the access network element to schedule the downlink service, and thus it is beneficial to ensure the end-to-end delay of the downlink service message. Furthermore, under normal circumstances, the user plane network element will receive messages of multiple downlink services for multiple access network elements. This method enables the user plane network element to cache the messages of the downlink service while giving priority to other downlink service messages, reasonably utilizing resources, alleviating and avoiding the processing conflict problem between downlink service messages sent to different access network network element nodes, and improving the processing efficiency of downlink service messages in the user plane network element, and thus it is beneficial to ensure the end-to-end delay requirements of the downlink service message and other downlink service messages.

[0021] In combination with the second aspect, in certain implementations of the second aspect, the time adjustment information is the first delay or a fourth time determined based on the first delay and the time when the downlink service message is expected to arrive at the user plane network element.

[0022] According to a third aspect, a method for downlink transmission is provided, comprising: an application network element receives time adjustment information related to a first delay from a session management network element, the first delay being the length of time between a time when an expected downlink service message arrives at the access network element and a time when the downlink service message is expected to arrive at the access network element, wherein the time when the expected downlink service message arrives at the access network element is within a first scheduling window, wherein 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 sends the downlink service message based on the time adjustment information, wherein a third time when the downlink service message sent at the second time arrives at the access network element is within the first scheduling window.

[0023] According to the downlink transmission method provided by the present application, the application network element can adjust the time when the application server sends the downlink service message according to the time adjustment information provided by the session management network element, so that when the downlink service message is sent at the adjusted sending time, the time when the downlink service message arrives at the access network element can be located in the first scheduling window of the access network element, and the downlink service message can be scheduled in the second downlink scheduling window, and the second downlink scheduling window is the next scheduling window adjacent to the first scheduling window. In this way, it is beneficial to reduce the scheduling waiting delay of the access network element to schedule the downlink service, and thus it is beneficial to ensure the end-to-end delay of the downlink service message. Furthermore, under normal circumstances, the application server will receive messages of multiple downlink services for multiple access network elements. This method enables the application server to cache the messages of the downlink service while giving priority to other downlink service messages, reasonably using resources, alleviating and avoiding the processing conflict problem between downlink service messages sent to different access network element nodes, and improving the processing efficiency of downlink service messages in the application server, which is beneficial to ensure the end-to-end delay requirements of the downlink service message and other downlink service messages.

[0024] In combination with the third aspect, in certain implementations of the third aspect, the time adjustment information includes one or more of the following: the first delay, the time when the expected downlink service message arrives at the user-plane network element determined based on the first delay, and the time when the expected downlink service message arrives at the terminal device determined based on the first delay.

[0025] In a fourth aspect, a method for downlink transmission is provided, including: an access network network element receives a time when a downlink service message is expected to arrive at the access network network element from a session management network element; the access network network element determines a first delay based on the time when the downlink service message is expected to arrive at the access network network element, the first delay being the length of time between the time when the access network network element expects the downlink service message to arrive at the access network network element and the time when the downlink service message is expected to arrive at the access network network element, wherein the time when the access network network element expects the downlink service message to arrive at the access network network element is within a first scheduling window, wherein the next scheduling window adjacent to the first scheduling window is a downlink scheduling window; the access network network element sends the first delay to the session management network element, and the first delay is used by the session management network element to adjust the time when the user plane network element and / or application server sends the downlink service message.

[0026] According to the method for downlink transmission provided by the present application, the access network element can provide the determined first delay to the session management element, and the session management element adjusts the time when the user plane element and / or the application server sends the downlink service message according to the first delay, and then the user plane element and / or the application server can send the downlink service message at the adjusted time, so that the time when the downlink service message arrives at the access network element can be within the first scheduling window of the access network element, and the downlink service message can be scheduled in the second downlink scheduling window, and the second downlink scheduling window is the next scheduling window adjacent to the first scheduling window. Thereby, it is beneficial to reduce the scheduling waiting delay of the access network element to schedule the downlink service, and further beneficial to ensure the end-to-end delay requirement of the downlink service message.

[0027] In combination with the fourth aspect, in certain implementations of the fourth aspect, the access network element determines the first delay based on the time when the downlink service message is expected to arrive at the access network element, including: the access network element determines the first delay based on the time when the downlink service message is expected to arrive at the access network element and the configuration information of the wireless resources of the access network element.

[0028] In combination with the fourth aspect, in certain implementations of the fourth aspect, the configuration information of the wireless resources includes a time slot start time, a time slot duration, an uplink and downlink time slot ratio, and a scheduling processing delay of the access network element.

[0029] In combination with the fourth aspect, in certain implementations of the fourth aspect, the access network network element determines the first delay based on the time when the downlink service message is expected to arrive at the access network network element and the configuration information of the wireless resources of the access network element, including: the access network network element determines the second downlink scheduling window in which the access network element is expected to schedule the downlink service based on the configuration information of the wireless resources and the time when the downlink service message is expected to arrive at the access network element; the access network network element determines the boundary of a third scheduling window based on the configuration information of the wireless resources and the second downlink scheduling window, the third scheduling window being the previous scheduling window of the second downlink scheduling window; the access network network element determines the first delay based on the boundary of the third scheduling window.

[0030] In a fifth aspect, a method for downlink transmission is provided, including: an access network network element receives a time when a downlink service message is expected to arrive at the access network element from a session management network element; the access network network element determines time adjustment information based on the time when the downlink service message is expected to arrive at the access network element and the configuration information of wireless resources; the access network 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 the time when the user plane network element and / or the application server sends the downlink service message.

[0031] According to the downlink transmission method provided in the present application, the access network element can determine the time adjustment information according to the time when the downlink service message is expected to arrive at the access network element and the configuration information of the wireless resources, and can provide the time adjustment information to the session management element. The session management element can adjust the time when the user plane network element and / or the application server sends the downlink service message according to the time adjustment information, and then the user plane network element and / or the application server can send the downlink service message at the adjusted time, so that the time when the downlink service message arrives at the access network element can be within the first scheduling window of the access network element, and the downlink service message can be scheduled in the second downlink scheduling window, and the second downlink scheduling window is the next scheduling window adjacent to the first scheduling window. Thereby, it is conducive to reducing the scheduling waiting delay of the access network element to schedule the downlink service, and thus it is conducive to ensuring the end-to-end delay requirement of the downlink service message.

[0032] In combination with the fifth aspect, in certain implementation methods of the fifth aspect, the access network network element determines the time adjustment information based on the time when the downlink service message is expected to arrive at the access network network element and the configuration information of the wireless resources, including: the access network network element determines a first delay based on the time when the downlink service is expected to arrive at the access network network element and the configuration information of the wireless resources, the first delay being the time length between the time when the access network network element expects the downlink service message to arrive at the access network network element and the time when the downlink service message is expected to arrive at the access network network element, wherein the time when the access network network element expects the downlink service message to arrive at the access network network element is within a first scheduling window, wherein the next scheduling window adjacent to the first scheduling window is a downlink scheduling window; the access network network element determines the time adjustment information based on the first delay.

[0033] In combination with the fifth aspect, in certain implementations of the fifth aspect, the access network network element determines the time adjustment information based on the time when the downlink service message is expected to arrive at the access network network element and the configuration information of the wireless resources, including: the access network network element determines the second downlink scheduling window in which the access network element is expected to schedule the downlink service message based on the time when the downlink service message is expected to arrive at the access network network element and the configuration information of the wireless resources; the access network network element determines the boundary of a third scheduling window based on the second downlink scheduling window, the third scheduling window being the previous scheduling window of the second downlink scheduling window; the access network network element determines the time adjustment information based on the boundary of the third scheduling window.

[0034] In combination with the fifth aspect, in certain implementations of the fifth aspect, the configuration information of the wireless resources includes the time slot start time, the time slot duration, the uplink and downlink time slot ratio, and the scheduling processing delay of the access network element.

[0035] In a sixth aspect, a method for downlink transmission is provided, comprising: a session management network element obtains first information, the first information including configuration information of wireless resources and a time when a downlink service message is expected to arrive at an access network element; the session management network element sends the first information to a user plane network element, the first information being used to determine a first time when the user plane network element sends the downlink service message, wherein a third time when the downlink service message sent at the first time arrives at the access network element is within a first scheduling window of the access network element, wherein a next scheduling window adjacent to the first scheduling window is a downlink scheduling window.

[0036] According to the downlink transmission method provided by the present application, the user plane network element can determine the sending time of the downlink service message according to the first information provided by the session management network element, so that the time when the downlink service message arrives at the access network element can be located within the first scheduling window of the access network element, and the downlink service message can be scheduled in the second downlink scheduling window, and the second downlink scheduling window is the next scheduling window adjacent to the first scheduling window. Therefore, it is beneficial to reduce the scheduling waiting delay of the access network element scheduling the downlink service, and further to ensure the end-to-end delay of the downlink service message.

[0037] In combination with the sixth aspect, in certain implementations of the sixth aspect, the configuration information of the wireless resources includes the time slot start time, the time slot duration, the uplink and downlink time slot ratio, and the scheduling processing delay of the access network element.

[0038] In combination with the sixth aspect, in certain implementations of the sixth aspect, the method further includes: the session management network element receives second information from the user plane network element, the second information being the first moment or the waiting delay of the downlink service message in the user plane network element; the session management network element determines the third moment based on the second information; and the session management network element sends the third moment to the access network element.

[0039] In the seventh aspect, a method for downlink transmission is provided, characterized in that it includes: a user-plane network element receives first information from a session management network element, the first information including configuration information of wireless resources and a time when a downlink service message is expected to arrive at an access network element; the user-plane network element determines a first time for sending the downlink service message based on the first information, wherein a third time when the downlink service message sent at the first time arrives at the access network element is within a first scheduling window of the access network element, wherein a next scheduling window adjacent to the first scheduling window is a downlink scheduling window.

[0040] According to the downlink transmission method provided by the present application, the user plane network element can determine the sending time of the downlink service message according to the first information provided by the session management network element, so that the time when the downlink service message arrives at the access network element can be located within the first scheduling window of the access network element, and the downlink service message can be scheduled in the second downlink scheduling window, and the second downlink scheduling window is the next scheduling window adjacent to the first scheduling window. Therefore, it is beneficial to reduce the scheduling waiting delay of the access network element scheduling the downlink service, and further to ensure the end-to-end delay of the downlink service message.

[0041] In combination with the seventh aspect, in certain implementations of the seventh aspect, the configuration information of the wireless resources includes the time slot start time, the time slot duration, the uplink and downlink time slot ratio, and the scheduling processing delay of the access network element.

[0042] In combination with the seventh aspect, in certain implementation methods of the seventh aspect, the user plane network element determines the first time to send the downlink service message based on the first information, including: the user plane network element determines a first delay based on the first information, the first delay being the time length between the time when the downlink service message is expected to arrive at the access network element and the time when the downlink service message is expected to arrive at the access network element; the user plane network element determines the first time based on the first delay.

[0043] In combination with the seventh aspect, in certain implementations of the seventh aspect, the method further includes: the user plane network element sends second information to the session management network element, the second information being the first moment or the waiting delay of the downlink service in the user plane network element, and the second information being used to determine the third moment.

[0044] In an eighth aspect, a communication device is provided, comprising modules or units for executing the method in any possible implementation of the first to seventh aspects or the first to seventh aspects.

[0045] In a ninth aspect, a device is provided, comprising a processor. The processor is coupled to a memory and can be used to execute instructions in the memory so that the device performs the method in any possible implementation of the first to seventh aspects or the first to seventh aspects. Optionally, the device also includes a memory. Optionally, the device also includes an interface circuit, and the processor is coupled to the interface circuit.

[0046] In a tenth aspect, a processor is provided, comprising: an input circuit, an output circuit, and a processing circuit. The processing circuit is used to receive a signal through the input circuit and transmit a signal through the output circuit, so that the processor executes the method in any possible implementation of the first to seventh aspects or the first to seventh aspects.

[0047] In the specific implementation process, the processor can be a chip, the input circuit can be an input pin, the output circuit can be an output pin, and the processing circuit can be a transistor, a gate circuit, a trigger, and various logic circuits. The input signal received by the input circuit can be, for example, but not limited to, received and input by a receiver, and the signal output by the output circuit can be, for example, but not limited to, output to a transmitter and transmitted by the transmitter, and the input circuit and the output circuit can be the same circuit, which is used as an input circuit and an output circuit at different times. The embodiments of the present application do not limit the specific implementation methods of the processor and various circuits.

[0048] In an eleventh aspect, a processing device is provided, comprising a processor and a memory. The processor is used to read instructions stored in the memory, and can receive signals through a receiver and transmit signals through a transmitter to execute the method in any possible implementation of the first to seventh aspects or the first to seventh aspects.

[0049] Optionally, the processor is one or more and the memory is one or more.

[0050] Optionally, the memory may be integrated with the processor, or the memory may be provided separately from the processor.

[0051] In the specific implementation process, the memory can be a non-transitory memory, such as a read-only memory (ROM), which can be integrated with the processor on the same chip or can be set on different chips respectively. The embodiments of the present application do not limit the type of memory and the setting method of the memory and the processor.

[0052] The processing device in the above-mentioned eleventh aspect can be a chip. The processor can be implemented by hardware or by software. When implemented by hardware, the processor can be a logic circuit, an integrated circuit, etc.; when implemented by software, the processor can be a general-purpose processor, which is implemented by reading the software code stored in the memory. The memory can be integrated in the processor or can be located outside the processor and exist independently.

[0053] In the twelfth aspect, a computer program product is provided, which includes: a computer program (also referred to as code, or instruction), which, when executed, enables a computer to execute a method in any possible implementation of the above-mentioned first to seventh aspects or the first to seventh aspects.

[0054] In the thirteenth aspect, a computer-readable medium is provided, which stores a computer program (also referred to as code, or instructions) which, when executed on a computer, enables the computer to execute the method in any possible implementation of the above-mentioned first to seventh aspects or the first to seventh aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is an architectural diagram of a system that can be applied to the present application.

[0056] Figure 2 It is a 5G system architecture diagram.

[0057] Figure 3 This is a schematic diagram of a TSN network centralized management architecture.

[0058] Figure 4 It is an architectural diagram for achieving end-to-end deterministic transmission for users.

[0059] Figure 5 The present invention is a schematic diagram of the prior art of scheduling downlink service messages by access network elements.

[0060] Figure 6 It is a schematic flowchart of a downlink transmission method provided by the present application.

[0061] Figure 7 This is a schematic diagram of an access network element scheduling downlink service messages provided by the present application.

[0062] Figure 8 It is a schematic flowchart of a downlink transmission method provided by the present application.

[0063] Fig. 9 This is a schematic diagram of an application server and an access network element scheduling downlink service messages provided by the present application.

[0064] Fig.10 It is a schematic flowchart of a downlink transmission method provided by the present application.

[0065] Fig.11 It is a schematic flowchart of a downlink transmission method provided by the present application.

[0066] Fig.12 It is a schematic flowchart of a downlink transmission method provided by the present application.

[0067] Fig.13 It is a schematic block diagram of a communication device provided by the present application.

[0068] Fig.14 It is a schematic block diagram of another communication device provided in the present application.

[0069] Fig.15 It is a structural diagram of a network device provided by this application. DETAILED DESCRIPTION

[0070] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0071] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as long term evolution (LTE) system, fifth generation (5G) system, new radio (NR) system or other communication systems that may appear in the future.

[0072] Figure 11 shows an architecture diagram of a system 100 that can be applied to the present application. Figure 1 As shown, the system 100 may include one or more of the following devices: terminal device 101, access network element 102, user plane network element 103, data network 104, access and mobility management network element 105, session management network element 106, policy control network element 107, application network element 108, unified data management network element 109 and network open network element 110.

[0073] Terminal device 101: can be user equipment (UE), user, access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device. For example, it can be a mobile phone, a tablet computer, a computer with 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 smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc. Terminal device 110 can also be a device or circuit structure set in the above-mentioned various devices, such as a chip or a chip system.

[0074] Access network element 102: capable of managing wireless resources, providing access services for terminal devices, and completing the forwarding of control signals and user data between the terminal devices and the core network.

[0075] The access network element 102 may be a transmission reception point (TRP), an evolved NodeB (eNB or eNodeB) in an LTE system, a home base station (for example, home evolved NodeB, or home Node B, HNB), a base band unit (BBU), or a wireless controller in a cloud radio access network (CRAN) scenario, or the access network device may be a relay station, an access point, a vehicle-mounted 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) network, etc., may be an access point (AP) in a WLAN, or may be a gNB in ​​a new radio (NR) system, and the embodiments of the present application are not limited thereto. In a network structure, the access network device may include a centralized unit (CU) node, or a distributed unit (DU) node, or an access network device including a CU node and a DU node, or an access network device including a control plane CU node (CU-CP node) and a user plane CU node (CU-UP node) and a DU node.

[0076] User plane network element 103: mainly responsible for processing user messages, such as forwarding and billing.

[0077] Data network 104: An operator network that provides data transmission services to users, such as IP Multimedia Service (IMS), the Internet, etc. DN may include an application server (AS), which is a software framework that provides an environment for application programs to run, and is used to provide security, data, transaction support, load balancing, large-scale distributed system management, and other services for applications. The terminal device obtains application messages by communicating with the AS. It should be noted that the above-mentioned AF is the control plane of the AS.

[0078] Access and mobility management network element 105: mainly responsible for mobility management in the mobile network, such as user location update, user registration network, user switching, etc.

[0079] Session management network element 106: mainly responsible for session management in the mobile network, such as session establishment, modification, and release. Specific functions include allocating IP addresses to users and selecting user plane network elements that provide message forwarding functions.

[0080] Policy control network element 107: responsible for providing policies such as quality of service (QoS) policy and slice selection policy to access and mobility management network elements and session management network elements.

[0081] Application network element 108: responsible for providing services to the 3GPP network, interacting with the policy control network element to perform policy control, etc.

[0082] Unified data management network element 109: used to store user data, such as contract information, authentication / authorization information.

[0083] Network open network element 110: provides the framework, authentication and interface related to network capability opening, and transmits information between 5G system network functions and other network functions.

[0084] It should be understood that the above-mentioned devices or network elements may be devices with corresponding functions, or may be software / hardware modules (such as chips) inside the device, etc. It should also be understood that any device or network element involved in the present application may be implemented in the form of software or a combination of software and hardware.

[0085] In one example, Figure 1 The system 100 shown may be Figure 2 It should be understood that the system 100 may also be a 4G system or other systems, which is not limited in this application.

[0086] Figure 2 This is a schematic diagram of the 5G system architecture. Figure 1 The network elements with the same reference numerals are Figure 1 The naming of the corresponding network elements in the current 5G system. Figure 2The 5G system architecture may include 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.

[0087] It should be understood that Figure 2 The naming of each network element shown is just a name, and the name does not limit the function of the network element itself. In different networks, the above network elements may also have other names, and the embodiments of the present application do not specifically limit this. For example, in a 6G network, some or all of the above network elements may use the terminology used in 5G, or may have other names, etc., which are uniformly explained here and will not be repeated below. Similarly, Figure 2 The interface between the network elements shown is only an example. In 5G networks and other future networks, the interface between network elements may not be the interface shown in the figure, and this application does not limit this.

[0088] It should also be understood that the embodiments of the present application are not limited to Figure 2 For example, the communication system to which the present application can be applied may include more or fewer network elements or devices. Figure 2 The equipment or network element in the network can be hardware, functionally divided software, or a combination of the two. Figure 2 Devices or network elements in a network can communicate through other devices or network elements.

[0089] In the forwarding implementation of traditional Ethernet networks, when a large number of data packets arrive at the forwarding port in an instant, it will cause large forwarding delays or packet loss. Therefore, traditional Ethernet cannot provide high reliability and guaranteed transmission delay services, and cannot meet the needs of automotive control, industrial Internet and other fields. In response to the demand for reliable delay transmission, the Institute of Electrical and Electronics Engineers (IEEE) defined the time sensitive network (TSN) standard, which provides reliable delay transmission services based on Layer 2 switching, ensuring the reliability of delay-sensitive service data transmission and predictable end-to-end transmission delay.

[0090] The TSN network is based on Layer 2 transmission and includes TSN switching nodes (also known as: TSN Bridge) and TSN endpoints (end station or endpoint). Different from Layer 2 forwarding, TSN switching nodes do not forward messages based on media access control address (MAC) learning, but forward messages based on forwarding rules configured or created on the TSN switching nodes. TSN flows are unidirectional flows. For a TSN flow, TSN endpoints are divided into senders (Talkers) and receivers (Listeners). The TSN standard defines the behavior of TSN switching nodes and TSN endpoints and the scheduling method for TSN switching nodes to forward data flows, thereby achieving reliable latency transmission. The TSN switching node uses the destination MAC address of the message as the identifier of the data flow, reserves resources and performs scheduling planning based on the latency requirements of the service flow, thereby ensuring reliability and transmission latency based on the generated scheduling strategy.

[0091] The TSN standard defines the centralized management architecture of the TSN network. Figure 3 The following figure shows a schematic diagram of the TSN network centralized management architecture. Figure 3 The architecture includes TSN endpoints (Talker / Listener), TSN switching nodes, and control plane network elements. The control plane network elements include centralized user configuration (CUC) and centralized network configuration (CNC). Among them:

[0092] A TSN endpoint is the sender or receiver of a data stream;

[0093] TSN switching nodes reserve resources for data flows according to the definition of the TSN network, and schedule and forward data packets;

[0094] CNC manages the topology of the user plane of the TSN network and the capability information of the TSN switching nodes (such as the sending delay of the TSN switching nodes and the internal processing delay between the ports of the TSN switching nodes), and generates the forwarding path of the data flow and the processing strategies on the TSN endpoints and each TSN switching node (such as the ports for sending and receiving messages, time gating parameters) according to the flow creation request provided by CUC, and then sends the processing strategies on the TSN switching nodes to the corresponding TSN switching nodes;

[0095] CUC is used to collect stream creation requests from TSN endpoints. After matching the requests from Talker and Listener, it requests CNC to create data streams and confirms the processing strategy generated by CNC.

[0096] In order to achieve end-to-end deterministic transmission for users, the 5G system (5G System, 5GS) defines the following Figure 4 The architecture shown. Figure 4 , 5GS is simulated as a switching node in the TSN network (hereinafter referred to as the 5GS switching node), realizing the node function of TSN switching, thereby realizing end-to-end deterministic transmission in the TSN network containing 5GS. Among them, AF adapts the information of 5GS to the information of the TSN switching node, interacts with CNC, and sends the information issued by CNC to 5GS through 5GS. The user plane TSN Translator (Device) (hereinafter referred to as the device side TSN converter, (Device Side–TSN Translator, DS-TT)) and TSN Translator (UP) (hereinafter referred to as the network side TSN converter, (Network Side–TSN Translator, NW-TT)) are logical functions of the 5GS user plane, which are used to realize the external characteristics of the TSN switching node, such as topology discovery, implementation of CNC scheduling rules, etc. DS-TT can be deployed in conjunction with UE or independently. Similarly, NW-TT can be deployed in conjunction with UPF or independently.

[0097] It should be noted that in this application, UPF can be replaced by NW-TT and UE can be replaced by DS-TT.

[0098] exist Figures 1 to 4 In any of the systems shown, taking into account the particularities of access network element scheduling, such as uplink and downlink ratios, TTI scheduling protection, etc., downlink services may introduce scheduling delays on the access network element side.

[0099] For example, see Figure 5 , Figure 5A schematic diagram of the prior art of scheduling downlink service messages by access network elements is shown. Figure 5 Four time slots are shown in FIG. 1 , each of which includes a scheduling window and a processing window. Each scheduling window can be used for uplink or downlink. The processing window is used for the access network element to process downlink service messages. Only if the downlink service message arrives before the start of the processing window can the downlink service message be scheduled in the nearest downlink scheduling window. However, the downlink service message may arrive at the access network element at any time. For example, Figure 5 As shown, if the time t1 when a downlink service message arrives at the access network element is within the downlink scheduling window 1 of the access network element, the access network element can schedule the downlink service message in the next nearest downlink scheduling window (i.e., downlink scheduling window 2) at the earliest. However, if the time t2 when a downlink service message arrives at the access network element is within the processing window of the access network element, the downlink service message can be scheduled in the next nearest downlink scheduling window (i.e., downlink scheduling window 3) at the earliest. If the time t3 when a downlink service message arrives at the access network element is within the downlink scheduling window 2 of the access network element, and the next adjacent scheduling window of the downlink scheduling window 2 is the uplink scheduling window 1, the downlink service message can be scheduled at least until the arrival of the next nearest downlink scheduling window (i.e., downlink scheduling window 3). If the time t4 when a downlink service message arrives at the access network element is within the uplink scheduling window 1 of the access network element, the access network element can schedule the downlink service message in the next nearest downlink scheduling window (i.e., downlink scheduling window 3) at the earliest. Among them, Figure 5 The downlink service message received at time t2 needs a delay of at least two time slots to be scheduled. Figure 5 The downlink service message received at time t3 requires a delay of at least one time slot to be scheduled. Therefore, the scheduling delay introduced by the access network element side may cause the end-to-end delay of the service to be unable to be guaranteed.

[0100] In view of this, the present application provides a method for downlink transmission, which can reduce the scheduling delay on the access network element side. The method provided by the present application is described below by taking the naming of the corresponding network element in the 5G network as an example.

[0101] It should be noted that the duration of the processing window is equal to the scheduling processing delay of the RAN mentioned below. The processing window is used for the access network element to process the downlink service message. Only when the downlink service message arrives before the start of the processing window can the downlink service message be scheduled in the nearest downlink scheduling window. The downlink service message arriving in the processing window must be scheduled in the nearest next downlink scheduling window, that is, it needs to wait for at least one more time slot.

[0102] It should be noted that the downlink service described in this application can be a periodic service, that is, the message can send a service message at a fixed interval, and the fixed interval is the sending period of the downlink service message. Generally, the size of the message sent in the next cycle in an industrial scenario can also be fixed.

[0103] In this application, the communication between SMF and AF may not be direct communication, but may be carried out through network elements such as PCF or NEF, which is not limited in this application. The communication between SMF and RAN may not be direct communication, but may be carried out through AMF.

[0104] In this application, unless otherwise specified, the same term in different embodiments has the same meaning. For example, the first time adjustment information is only described in method 600, and the meaning of the first time adjustment information below can refer to the description in method 600.

[0105] Figure 6 This is a schematic flow chart of a downlink transmission method provided by the present application. Figure 6 Method 600 is shown for illustration.

[0106] S601, SMF obtains a first delay.

[0107] The first delay is the time length between the time when the downlink service packet is expected to arrive at the RAN and the time when the downlink service packet is expected to arrive at the RAN. The time when the downlink service packet is expected to arrive at the RAN is within the first scheduling window, and the next scheduling window adjacent to the first scheduling window is the downlink scheduling window; wherein, the "expected" can be understood as the "original plan" rather than the actual occurrence.

[0108] In this paper, the time when RAN expects the downlink service message to arrive at RAN is recorded as: RANyt The time when the downlink service message is expected to arrive at the RAN is recorded as: t RANya .

[0109] Then, the first delay = t RANyt -t RANya .

[0110] For example, suppose t RANyt 10:30, t RANya is 10:29, so the first delay is 1 minute.

[0111] Two methods of obtaining the first delay by SMF are described below.

[0112] Method 1:

[0113] The first delay obtained by the SMF is determined by itself.

[0114] Optionally, the SMF may obtain the configuration information of the radio resources of the RAN and the time t at which the downlink service message is expected to arrive at the RAN. RANya , and according to the configuration information of the wireless resource and the estimated arrival time t of the downlink service message at the RAN RANya , determine the first delay.

[0115] Exemplarily, the configuration information of the wireless resource may include at least one of the time slot start time, the time slot duration or the number of symbols in the time slot, the uplink and downlink time slot ratio, and the scheduling processing delay of the RAN. The SMF may determine the time slot according to the configuration information of the wireless resource. Figure 5 The boundary of the scheduling window, the boundary of the processing window, and whether a scheduling window is an uplink scheduling window or a downlink scheduling window.

[0116] For example, RAN can report the configuration information of wireless resources and the corresponding cell ID to AMF during the NG Setup process, and SMF can obtain the configuration information of wireless resources and the cell ID from AMF. The NG Setup process can be called the N2 Setup process, and the interface between RAN and AMF is called the NG interface.

[0117] Alternatively, during the UE registration process, when the RAN forwards the registration request to the AMF, it may carry the cell ID and the configuration information of the radio resources, or carry the cell ID, UE ID and the configuration information of the radio resources. Then, the SMF may obtain the configuration information of the radio resources from the AMF.

[0118] Alternatively, when the session is established, the RAN may send the cell ID and the configuration information of the corresponding wireless resources to the SMF through an N2 message, or send the cell ID, UE ID and the configuration information of the corresponding wireless resources.

[0119] Alternatively, the RAN may provide the configuration information of the wireless resources corresponding to the cell to the Network Data Analytics Function (NWDAF), and the SMF may obtain the configuration information of the wireless resources and the corresponding cell ID from the NWDAF.

[0120] In one example, the SMF may determine the time t at which the downlink service message is expected to arrive at the RAN based on the transmission delay from the UPF to the RAN and the time at which the downlink service message is expected to arrive at the UPF. RANya .

[0121] In this paper, the transmission delay from UPF to RAN is recorded as: T UPF-RAN ; The time when the downlink service message is expected to arrive at UPF is recorded as: t UPFya .

[0122] For example, RANya =T UPF-RAN +t UPFya Or, t RANya =T UPF-RAN +t UPFya +T UPF , where T UPF T is the buffering (or queuing) time of the downlink service message in the UPF. UPF It can be determined by SMF or UPF based on the delay requirement or service priority in the QoS information, but this application is not limited to this.

[0123] In another example, the SMF may obtain QoS information of the downlink service message (or downlink service) from the PCF, and determine the time when the downlink service message is expected to arrive at the RAN based on the QoS information.

[0124] Specifically, the QoS information or PCC rule (Policy of Charging and Control rule) provided by the PCF includes the time when the downlink service message is expected to arrive at the UPF. The SMF receives the QoS information or PCC rule from the PCF, obtains the time when the downlink service message is expected to arrive at the UPF, and then determines the time when the downlink service message is expected to arrive at the RAN based on the time when the downlink service message is expected to arrive at the UPF. The QoS information or PCC rule may also include the period of the downlink service message and the total amount of service messages within the period.

[0125] Further, the SMF determines the first delay based on the configuration information of the wireless resources and the time when the downlink service message is expected to arrive at the RAN, which may include: the SMF determines a second downlink scheduling window in which the RAN plans to schedule the downlink service message based on the configuration information of the wireless resources and the time when the downlink service message is expected to arrive at the RAN; the SMF determines a boundary of a third scheduling window based on the second downlink scheduling window, and the third scheduling window is a previous scheduling window of the second downlink scheduling window; the SMF determines the first delay based on the boundary of the third scheduling window.

[0126] Combine the following Figure 5 Give an example.

[0127] Example 1: Assume that the downlink service message is expected to arrive at the RAN at time t RANya=t1, then the SMF can determine that the second downlink scheduling window in which the RAN is expected to schedule the downlink service message is the downlink scheduling window 2 according to the configuration information of the wireless resources and t1. Then, the time when the downlink service message is expected to arrive at the RAN is in the third scheduling window, and the third scheduling window is the previous scheduling window of the second downlink scheduling window, that is, the downlink scheduling window 1. The first delay can be the time length T2 between the upper boundary of the downlink scheduling window 1 (that is, the one 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 time when the downlink service message is expected to arrive at the RAN can be understood as the upper boundary of the downlink scheduling window 1, or any time between t1 and the upper boundary of the downlink scheduling window 1 (including t1).

[0128] Example 2: Assume that the downlink service message is expected to arrive at the RAN at time t RANya =t2, then the SMF can determine that the second downlink scheduling window in which the RAN is expected to schedule the downlink service message is the downlink scheduling window 3 according to the configuration information of the wireless resources and t2. Then, the time when the downlink service message is expected to arrive at the RAN is in the third scheduling window, and the third scheduling window is the previous scheduling window of the second downlink scheduling window, that is, the uplink scheduling window 1. The first delay can be the time length T3 between the lower boundary of the uplink scheduling window 1 (that is, 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 can be the time length T4 between the upper boundary of the uplink scheduling window 2 (that is, 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 can be any value greater than T3 and less than T4. In Example 2, the time when the downlink service message is expected to arrive at the RAN can be understood as the upper boundary of the uplink scheduling window 1, or any time between the lower boundary of the uplink scheduling window 1 and the upper boundary of the uplink scheduling window 1 (including the lower boundary of the uplink scheduling window 1).

[0129] Example 3: Assume that the downlink service message is expected to arrive at the RAN at time t RANya=t3, then the SMF can determine that the second downlink scheduling window in which the RAN is expected to schedule the downlink service message is the downlink scheduling window 3 according to the configuration information of the wireless resources and t3. Then, the time when the downlink service message is expected to arrive at the RAN is in the third scheduling window, and the third scheduling window is the previous scheduling window of the second downlink scheduling window, that is, the uplink scheduling window 1. The first delay can be the time length T5 between the lower boundary of the uplink scheduling window 1 and t3. Alternatively, the first delay can be the time length T6 between the upper boundary of the uplink scheduling window 1 and t3. Alternatively, the first delay can be any value greater than T5 and less than T6. In Example 3, the time when the downlink service message is expected to arrive at the RAN can be understood as the upper boundary of the uplink scheduling window 1, or any time between the lower boundary of the uplink scheduling window 1 and the upper boundary of the uplink scheduling window 1 (including the lower boundary of the uplink scheduling window 1).

[0130] Example 4: Assume that the downlink service message is expected to arrive at the RAN at time t RANya =t4, then the SMF can determine that the second downlink scheduling window in which the RAN is expected to schedule the downlink service message is the downlink scheduling window 3 according to the configuration information of the wireless resources and t4. Then, the time when the downlink service message is expected to arrive at the RAN is in the third scheduling window, and the third scheduling window is the previous scheduling window of the second downlink scheduling window, that is, the uplink scheduling window 1. The first delay can be the time length T7 between the upper boundary of the uplink scheduling window 1 and t4. Or, the first delay can be any value less than T7. In Example 4, the time when the downlink service message is expected to arrive at the RAN can be understood as the upper boundary of the uplink scheduling window 1, or any time between t4 and the upper boundary of the uplink scheduling window 1 (including t4). In the above examples, the first delay can also be a time range, such as the first delay in Example 1 can be [0, T2], the first delay in Example 2 can be [T3, T4], the first delay in Example 3 can be [T5, T6], and the first delay in Example 4 can be [0, T7].

[0131] Method 2:

[0132] The SMF may obtain the first delay from the RAN. That is, the RAN may determine the first delay and send the first delay to the SMF.

[0133] For example, the SMF may obtain the estimated time t at which the downlink service message arrives at the RAN. RANya , and then sends the estimated arrival time t of the downlink service message to RAN RANya The estimated time t at which the downlink service message is received by RAN RANya After that, the time t at which the downlink service message arrives at the RAN can be estimated based on the downlink service message. RANya, determine the first delay, and then send it to SMF.

[0134] For example, the RAN may estimate the time t at which the downlink service message arrives at the RAN. RANya How to determine the first delay according to the estimated arrival time t of the downlink service message at the RAN RANya and the configuration information of the wireless resource, determine the first delay, which can refer to the above description of the time t at which the SMF is expected to arrive at the RAN according to the downlink service message RANya The description of determining the first delay based on the configuration information of the wireless resources will not be repeated here.

[0135] In addition, how does SMF obtain the estimated time t when the downlink service message arrives at RAN? RANya You can also refer to the above to obtain the estimated time t of the downlink service message arriving at the RAN by SMF RANya The description of the method will not be repeated here.

[0136] Optionally, S601 may only be performed at the time t when the downlink service message is expected to arrive at the RAN. RANya The processing window of the RAN, or only at t RANya For example, if the downlink service message is expected to arrive at the RAN at time t RANya = t1 or t4, then step S601 may not be executed, or method 600 may not be executed.

[0137] S602, SMF sends time adjustment information related to the first delay to UPF (ie, an example of the first network element). Correspondingly, UPF receives the time adjustment information from SMF.

[0138] Hereinafter, the time adjustment information is recorded as: first time adjustment information. It should be understood that, since the first time delay can be a moment or a time range, the first time adjustment information can be a moment or a time range.

[0139] The first time adjustment information may be the first time delay. Alternatively, the first time adjustment information may be based on the first time delay and the time t at which the downlink service message is expected to arrive at the UPF. UPFya The fourth moment of certainty.

[0140] The fourth moment is the moment when the expected UPF sends the downlink service message. For example, the fourth moment = t UPFya + first delay. Or, fourth moment = t UPFya +First delay+T UPF , T UPFThe meaning of is as above. If the first delay is a time range, SMF can compare a specific value within the time range with t UPFya Add, or with t UPFya and T UPF Add together to get the fourth moment. SMF can also compare this time range with t UPFya Add, then and t UPFya and T UPF Adding together, a new time range is obtained, and the new time range can be used as the fourth moment, or any moment in the new time range can be used as the fourth moment.

[0141] S603, UPF determines the time (referred to as: first time) for sending the downlink service message according to the first time adjustment information.

[0142] The time (referred to as the third time) when the downlink service message sent by the UPF at the first time arrives at the RAN is within the first scheduling window of the RAN, wherein the next scheduling window adjacent to the first scheduling window is the downlink scheduling window. That is, the UPF will send the downlink service message at the first time, so that the downlink service message 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.

[0143] For example, if the first time adjustment information is the first delay, the UPF can determine that the first moment is the moment when the UPF is expected to send the downlink service message. UPFya and the sum of the first delay.

[0144] For example, if the first time adjustment information is the fourth time, the UPF may determine that the first time is the fourth time, or the first time is the fourth time minus T UPF Get the moment.

[0145] It should be understood that when the first time adjustment information is a specific moment, the fourth moment is a specific moment. When the first time adjustment information is a time range, the fourth moment can be any value within a new time range obtained according to the above calculation method.

[0146] S604, when UPF receives the downlink service message, it sends the downlink service message at the first moment.

[0147] Combination Figure 7 See also Figure 7, if the UPF sends the downlink service message at time t5 as originally planned, the time when the downlink service message arrives at the RAN is t2, and the downlink service message needs to be cached for at least two time slots on the RAN side before it can be scheduled, that is, the downlink service message can be scheduled at the earliest in the downlink scheduling window 3. If the sending time of the downlink service message is adjusted to the first time, the time when the downlink service message arrives at the RAN will be within the first scheduling window of the RAN, which will reduce the time for the RAN to cache the downlink service message. For example, if the first time is t7, the time t4 when the downlink service message 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 downlink service message is cached at the RAN can be reduced by the duration of t7-t5. For another example, if the UPF sends the downlink service message at time t6 as originally planned, the time when the downlink service message arrives at the RAN is t3, and the downlink service message needs to be cached for at least one time slot on the RAN side before it can be scheduled, that is, the downlink service message can be scheduled at the earliest in the downlink scheduling window 3. If the sending time of the downlink service message is adjusted to the first time, the time when the downlink service message arrives at the RAN will be within the first scheduling window of the RAN, which will reduce the time for the RAN to cache the downlink service message. For example, if the first time is t7, the time t4 when the downlink service message 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. The time that the downlink service message is cached at the RAN can be reduced by t7-t6.

[0148] Therefore, according to the downlink transmission method provided by the present application, the UPF can adjust the sending time of the downlink service message according to the time adjustment information provided by the SMF, so that when the UPF sends the downlink service message at the adjusted sending time, the time when the downlink service message arrives at the RAN can be located within the first scheduling window of the RAN, and the downlink service message can be scheduled in the second downlink scheduling window, and the second downlink scheduling window is the next scheduling window adjacent to the first scheduling window. In this way, it is beneficial to reduce the scheduling waiting delay of the access network element scheduling the downlink service message. Furthermore, under normal circumstances, the UPF will be connected to multiple RANs and will receive multiple downlink service messages. This method enables the UPF to cache the downlink service message while giving priority to other downlink service messages, reasonably utilizing resources, alleviating and avoiding the processing conflict problem between downlink service messages sent to different RANs, and improving the processing efficiency of downlink service messages in the UPF, which is beneficial to ensuring the end-to-end delay requirements of the downlink service message and other downlink service messages.

[0149] Optionally, the method may further include:

[0150] S605, SMF determines the third time according to the first time adjustment information.

[0151] Specifically, the third time is the time when the downlink service message arrives at the RAN. For example, the third time = t RANya + first time adjustment information, or third time = fourth time + T UPF-RAN Or, the third time and the time t when the downlink service message is expected to arrive at the RAN RANyt The same. Among them, t RANya and T UPF-RAN The meaning of can be found in the previous description.

[0152] Since the first time adjustment information can be a moment or a time range, the third moment can be a moment or a time range.

[0153] S606, SMF sends a third time to RAN, where the third time is used by RAN to schedule the downlink service message.

[0154] Specifically, after RAN receives the third moment when SMF sends the downlink service message, it can determine the moment when the downlink service message arrives at RAN according to the third moment. After determining the moment when the downlink service message arrives at RAN, RAN can schedule the downlink service message according to the moment. For example, RAN can perform semi-static scheduling on the downlink service message according to the cycle of the downlink service message and the moment when the downlink service message arrives at RAN, that is, it can allocate the same time-frequency resources that can be periodically reused to the downlink service message at one time, which can reduce the end-to-end transmission delay of the downlink service message and save control plane resources.

[0155] Figure 8 is an exemplary flow chart of another downlink transmission method provided by the present application. Figure 8 Method 800 is shown for illustration.

[0156] S801, SMF obtains a first delay.

[0157] The first delay is the time length between the time when the downlink service packet is expected to arrive at the RAN and the time when the downlink service packet is expected to arrive at the RAN, wherein the time when the downlink service packet is expected to arrive at the RAN is within the first scheduling window, wherein the next scheduling window adjacent to the first scheduling window is the downlink scheduling window. The "expected" can be understood as "original plan" rather than actual occurrence.

[0158] In this paper, the time when the downlink service message is expected to arrive at the RAN is recorded as: t RANyt The time when the downlink service message is expected to arrive at the RAN is recorded as: tRANya .

[0159] Then, the first delay = t RANyt -t RANya .

[0160] For example, suppose t RANyt 10:30, t RANya is 10:29, so the first delay is 1 minute.

[0161] Two methods of obtaining the first delay by SMF are described below.

[0162] Method 1:

[0163] The first delay obtained by the SMF is determined by itself.

[0164] Optionally, the SMF may obtain the configuration information of the radio resources of the RAN and the time t at which the downlink service message is expected to arrive at the RAN. RANya , and according to the configuration information of the wireless resource and the estimated arrival time t of the downlink service message at the RAN RANya , determine the first delay.

[0165] Exemplarily, the configuration information of the wireless resources may include the time slot start time, the time slot duration or the number of symbols in the time slot, etc., which can be used to calculate the time slot duration, the uplink and downlink time slot ratio, and the scheduling processing delay of the RAN.

[0166] For example, RAN can report the configuration information of wireless resources and the corresponding cell ID to AMF during the NG Setup process, and SMF can obtain the configuration information of wireless resources and the cell ID from AMF. The NG Setup process can be called the N2 Setup process, and the interface between RAN and AMF is called the NG interface.

[0167] Alternatively, during the UE registration process, when the RAN forwards the registration request to the AMF, it may carry the cell ID and the configuration information of the radio resources, or carry the cell ID, UE ID and the configuration information of the radio resources. Then, the SMF may obtain the configuration information of the radio resources from the AMF.

[0168] Alternatively, when the session is established, the RAN may send the cell ID and the configuration information of the corresponding wireless resources to the SMF through an N2 message, or send the cell ID, UE ID and the configuration information of the corresponding wireless resources.

[0169] Alternatively, the RAN may provide the configuration information of the wireless resources corresponding to the cell to the Network Data Analytics Function (NWDAF), and the SMF may obtain the configuration information of the wireless resources and the corresponding cell ID from the NWDAF.

[0170] In one example, the SMF may determine the time t at which the downlink service message is expected to arrive at the RAN based on the transmission delay from the UPF to the RAN and the time at which the downlink service message is expected to arrive at the UPF. RANya .

[0171] In this paper, the transmission delay from UPF to RAN is recorded as: T UPF-RAN ; The time when the downlink service message is expected to arrive at UPF is recorded as: t UPFya .

[0172] For example, RANya =T UPF-RAN +t UPFya Or, t RANya =T UPF-RAN +t UPFya +T UPF , where T UPF T is the buffering (or queuing) time of the downlink service message in the UPF. UPF It can be determined by SMF or UPF based on the delay requirement or service priority in the QoS information, but this application is not limited to this.

[0173] In another example, the SMF may obtain QoS information of the downlink service message (or downlink service) from the PCF, and determine the time when the downlink service message is expected to arrive at the RAN based on the QoS information.

[0174] Specifically, the QoS information or PCC rules (Policy of Charging and Control rules) provided by the PCF include the time when the downlink service message is expected to arrive at the UPF. The SMF receives the QoS information or PCC rules from the PCF, obtains the time when the downlink service message is expected to arrive at the UPF, and then determines the time when the downlink service message is expected to arrive at the RAN based on the time when the downlink service message is expected to arrive at the UPF. The QoS information or PCC rules may also include the period of the downlink service message and the size of the burst within the period.

[0175] Further, the SMF determines the first delay based on the configuration information of the wireless resources and the time when the downlink service message is expected to arrive at the RAN, which may include: the SMF determines a second downlink scheduling window in which the RAN plans to schedule the downlink service message based on the configuration information of the wireless resources and the time when the downlink service message is expected to arrive at the RAN; the SMF determines a boundary of a third scheduling window based on the second downlink scheduling window, and the third scheduling window is a previous scheduling window of the second downlink scheduling window; the SMF determines the first delay based on the boundary of the third scheduling window.

[0176] For specific examples, please refer to Example 1 to Example 4 in step S601.

[0177] In addition, the SMF determines the first delay based on the configuration information of the wireless resource and the time when the downlink service message is expected to arrive at the RAN, which may include: the SMF determines the second downlink scheduling window in which the RAN is expected to schedule the downlink service message based on the configuration information of the wireless resource and the time when the downlink service message is expected to arrive at the RAN; the SMF determines the boundary of the fifth scheduling window based on the second downlink scheduling window, the fifth scheduling window is the window in which the RAN is expected to schedule the downlink service message, and the fifth scheduling window is the previous downlink scheduling window of the second downlink scheduling window; the SMF determines the sixth scheduling window based on the boundary of the fifth scheduling window, the sixth scheduling window is the scheduling window at which the downlink service message is expected to arrive at the RAN; the AMF determines the first delay based on the boundary of the sixth scheduling window.

[0178] It should be understood that the time when the downlink service packet is expected to arrive at the RAN determined according to the method is earlier than or equal to the time when the downlink service packet is expected to arrive at the RAN.

[0179] Combine the following Figure 5 Give an example.

[0180] Example 5: Assume that the packet of the downlink service is expected to arrive at the RAN at time t RANya=t2, then the SMF can determine that the second downlink scheduling window in which the RAN is expected to schedule the message of the downlink service is the downlink scheduling window 3 according to the configuration information of the radio resources and t2. Then, the window in which the RAN is expected to schedule the message of the downlink service is the fifth scheduling window, and the fifth scheduling window is the previous downlink scheduling window of the second downlink scheduling window, that is, the downlink scheduling window 2, and the sixth scheduling window is the downlink scheduling window 1. Therefore, the first delay can be the time length T3' between the lower boundary of the downlink scheduling window 1 (that is, the boundary of the two boundaries of the downlink scheduling window 1, which is farther from the downlink scheduling window 2) and t2. Alternatively, the first delay can be the time length T4' between the upper boundary of the downlink scheduling window 1 (that is, the boundary of the two boundaries of the downlink scheduling window 1, which is closer to the downlink scheduling window 2) and t2. Alternatively, the first delay can be any value greater than T4' and less than T3'. In Example 5, the time when the expected downlink service message arrives at the RAN can be understood as the upper boundary of the downlink scheduling window 1, or any time between the lower boundary of the uplink scheduling window 1 and the upper boundary of the uplink scheduling window 1 (including the lower boundary of the uplink scheduling window 1).

[0181] Example 6: Assume that the packet of the downlink service is expected to arrive at the RAN at time t RANya =t3, then the SMF can determine that the second downlink scheduling window in which the RAN is expected to schedule the message of the downlink service is the downlink scheduling window 3 according to the configuration information of the wireless resources and t3. Then, the window in which the RAN is expected to schedule the downlink service message is the fifth scheduling window, and the fifth scheduling window is the previous downlink scheduling window of the second downlink scheduling window, that is, the downlink scheduling window 2, and the sixth scheduling window is the downlink scheduling window 1. Therefore, the first delay can be the time length T5' between the lower boundary of the downlink scheduling window 1 and t3. Alternatively, the first delay can be the time length T6' between the upper boundary of the downlink scheduling window 1 and t3. Alternatively, the first delay can be any value greater than T6' and less than T5'. In Example 6, the time when the downlink service message is expected to arrive at the RAN can be understood as the upper boundary of the uplink scheduling window 1, or any time between the lower boundary of the uplink scheduling window 1 and the upper boundary of the uplink scheduling window 1 (including the lower boundary of the uplink scheduling window 1).

[0182] In each of the above examples, the first time delay may be a time range, such as [T4', T3'] in Example 5 and [T6', T5'] in Example 6.

[0183] Method 2:

[0184] The SMF may obtain the first delay from the RAN. That is, the RAN may determine the first delay and send the first delay to the SMF.

[0185] For example, the SMF may obtain the estimated time t at which the downlink service message arrives at the RAN. RANya , and then sends the estimated arrival time t of the downlink service message to RAN RANya The estimated time t at which the downlink service message is received by RAN RANya After that, the time t at which the downlink service message arrives at the RAN can be estimated based on the downlink service message. RANya , determine the first delay, and then send it to SMF.

[0186] For example, the RAN may estimate the time t at which the downlink service message arrives at the RAN. RANya How to determine the first delay according to the estimated arrival time t of the downlink service message at the RAN RANya and the configuration information of the wireless resource, determine the first delay, which can refer to the above description of the time t at which the SMF is expected to arrive at the RAN according to the downlink service message RANya The description of determining the first delay based on the configuration information of the wireless resources will not be repeated here.

[0187] In addition, how does SMF obtain the estimated time t when the downlink service message arrives at RAN? RANya You can also refer to the above to obtain the estimated time t of the downlink service message arriving at the RAN by SMF RANya The description of the method will not be repeated here.

[0188] Optionally, S801 may only be performed at the time t when the downlink service message is expected to arrive at the RAN. RANya The processing window of the RAN, or only at t RANya For example, if the downlink service message is expected to arrive at the RAN at time t RANya = t1 or t4, then step S801 may not be executed, or method 800 may not be executed.

[0189] S802, SMF sends time adjustment information related to the first delay to AF (ie, another example of the first network element). Correspondingly, AF receives the time adjustment information from SMF.

[0190] Hereinafter, the time adjustment information is referred to as the second time adjustment information.

[0191] Optionally, the second time adjustment information may include one or more of the following: the first delay, the expected time when the downlink service message arrives at the UPF based on the first delay, and the expected time when the downlink service message arrives at the UE based on the first delay.

[0192] Exemplarily, if the second time adjustment information is the first delay, the SMF can indicate to the AF whether the first delay is an advance amount or a lag amount. For example, if the first delay is determined according to the boundary of the third scheduling window, the first delay is a lag amount; if the first delay is determined according to the boundary of the sixth scheduling window, the first delay is an advance amount. If the first delay is an advance amount, the length of time that the sending time of the downlink service message determined by the AF is ahead of the expected sending time is the first delay; if the first delay is a lag amount, the length of time that the sending time of the downlink service message determined by the AF is delayed from the expected sending time is the first delay.

[0193] Optionally, the SMF may provide additional instructions to the AF only when the first time delay is a lag amount; when there is no additional indication, the first time delay is an advance amount.

[0194] Optionally, the SMF may also provide the AF with both an advanced first delay and a delayed first delay for the AF to select.

[0195] It should be understood that if the second time adjustment information is not the first delay, or includes other items among the above items except the first delay, the SMF first determines the second time adjustment information or other items among the above items except the first delay based on the first delay, and then sends the determined information to the AF.

[0196] For example, the expected time when the downlink service message arrives at the UPF may be the sum or difference between the time when the downlink service message is expected to arrive at the UPF and the first delay. For example, if the first delay is determined according to the boundary of the third scheduling window, the expected time when the downlink service message arrives at the UPF may be the sum of the time when the downlink service message is expected to arrive at the UPF and the first delay; if the first delay is determined according to the boundary of the sixth scheduling window, the expected time when the downlink service message arrives at the UPF may be the difference between the time when the downlink service message is expected to arrive at the UPF and the first delay.

[0197] The expected time when the downlink service message arrives at the UE may be the sum or difference between the time when the downlink service message is expected to arrive at the UE and the first delay. For example, if the first delay is determined according to the boundary of the third scheduling window, the expected time when the downlink service message arrives at the UE may be the sum of the time when the downlink service message is expected to arrive at the UE and the first delay; if the first delay is determined according to the boundary of the sixth scheduling window, the expected time when the downlink service message arrives at the UPF may be the difference between the time when the downlink service message is expected to arrive at the UE and the first delay.

[0198] Since the first time delay can be a time range, and the second time adjustment information is determined based on the first time delay, the second time adjustment information can be a moment or a time range. When the first time delay is a time range, the second time adjustment information can be a time range determined by the SMF based on the first time delay, or the SMF can determine a time range based on the first time delay, and then determine a moment within the time range as the second time adjustment information based on the time range.

[0199] S803: The AF determines a second time at which the AS sends the downlink service message according to the second time adjustment information.

[0200] The third time when the downlink service message sent at the second time arrives at the RAN is within the first scheduling window of the RAN, wherein the next scheduling window adjacent to the first scheduling window is the downlink scheduling window. That is, the AS will send the downlink service message at the second time, so that the downlink service message 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.

[0201] For example, if the second time adjustment information is the first delay, the AF can determine that the second time is the time t when the AS is expected to send the downlink service message. ASya Specifically, if the first delay is an advance amount, the second time is the time t when the AS expects to send the downlink service message. ASya The difference between the first delay and the first delay; if the first delay is a lag, the second time is the time t when the AS is expected to send the downlink service message ASya and the sum of the first delay.

[0202] For example, if the second time adjustment information is the expected time when the downlink service message arrives at the UPF, the AF can adjust the time according to the expected time when the downlink service message arrives at the UPF. UPFya The expected time t at which the downlink service message arrives at the UPF UPFqa The second moment is determined by the difference between ASys +t UPFqa -t UPFya , where t ASys The time when the AS expects to send the downlink service message.

[0203] For example, if the second time adjustment information is the expected time when the downlink service message arrives at the UE, the AF can adjust the time when the downlink service message arrives at the UE according to the expected time t UEya The expected time t at which the downlink service message arrives at the UPF UEqa The second moment is determined by the difference betweenASys +t UEqa -t UEya , where t ASys The time when the AS expects to send the downlink service message.

[0204] If the second time adjustment information is a time range, the AF may first determine a specific moment within the time range according to the time range, and then determine the second moment according to the specific moment. Alternatively, the AF may directly determine a time range according to the second time adjustment information, and then determine a second moment within the time range according to the time range.

[0205] S804, AF sends the second time to AS.

[0206] S805, the AS sends the message of the downlink service at the second moment.

[0207] Combination Fig. 9 See also Fig. 9 , if the AS sends the message of the downlink service at time t9, the time when the message of the downlink service arrives at the RAN is t2. The message of the downlink service needs to be cached on the RAN side for at least two time slots before it can be scheduled, that is, the message of the downlink service can be scheduled in the downlink scheduling window 3 at the earliest. If the sending time of the message of the downlink service is adjusted to the second time, the time when the message of the downlink service arrives at the RAN will be within the first scheduling window of the RAN, which will reduce the time for the RAN to cache the message of the downlink service. For example, if the second time is t11, the time when the message of the downlink service 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. The time when the message of the downlink service is cached can be reduced by the duration of t11-t9. For another example, if the second time is t8, the time when the message of the downlink service arrives at the RAN is within the downlink scheduling window 1 of the RAN. The message of the downlink service can be scheduled in the downlink scheduling window 2 by caching one time slot, and the time when the message of the downlink service is cached can be reduced by one time slot.

[0208] For another example, if the AS sends the message of the downlink service at time t10, the time when the message of the downlink service arrives at the RAN is t3. The message of the downlink service needs to be cached on the RAN side for at least one time slot before it can be scheduled, that is, the message of the downlink service can be scheduled in the downlink scheduling window 3 at the earliest. If the sending time of the message of the downlink service is adjusted to the second time, the time when the message of the downlink service arrives at the RAN will be within the first scheduling window of the RAN, which will reduce the time for the RAN to cache the message of the downlink service. For example, if the second time is t11, the time when the message of the downlink service 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. The time when the message of the downlink service is cached can be reduced by the duration of t11-t10. For another example, if the second time is t8, the time when the message of the downlink service arrives at the RAN is within the downlink scheduling window 1 of the RAN. The message of the downlink service can be scheduled in the downlink scheduling window 2 by caching one time slot, and the cache time of the message of the downlink service can be reduced by one time slot.

[0209] Therefore, according to the downlink transmission method provided by the present application, the AF can adjust the time when the AS sends the downlink service message according to the time adjustment information provided by the SMF, so that when the AS sends the downlink service message at the adjusted sending time, the time when the downlink service message arrives at the RAN can be located within the first scheduling window of the RAN, and the downlink service message can be scheduled in the second downlink scheduling window, and the second downlink scheduling window is the next scheduling window adjacent to the first scheduling window. In this way, it is beneficial to reduce the scheduling waiting delay of the access network element scheduling the downlink service, and thus it is beneficial to ensure the end-to-end delay of the downlink service message. Furthermore, under normal circumstances, the AS will receive multiple downlink service messages for multiple RANs. This method enables the AS to cache the downlink service message while giving priority to other downlink service messages, reasonably using resources, alleviating and avoiding the processing conflict problem between downlink service messages sent to different RAN nodes, and improving the processing efficiency of the downlink service message in the AS, which is beneficial to ensure the end-to-end delay requirements of the downlink service message and other downlink service messages.

[0210] Optionally, the method 800 may further include:

[0211] S806: SMF determines the third time according to the second time adjustment information.

[0212] The third moment is the moment when the message of the downlink service arrives at the RAN.

[0213] Exemplarily, if the second time adjustment information is the first time delay, and the first time delay is the advance amount, then the third time is =t RANya- Adjust information in the second time.

[0214] If the second time adjustment information is the first time delay, and the first time delay is the hysteresis, then the third time is =t RANya + Second time adjustment information.

[0215] If the second time adjustment information is the expected time t of the downlink service message arriving at the UPF UPFya , then the third moment is =t UPFya +T UPF-RAN Adjust information in the second time.

[0216] If the second time adjustment information is the expected time t at which the downlink service message arrives at the UE UPFya , then the third moment is =t UEya +T UE-RAN Adjust information in the second time.

[0217] t RANya and T UPF-RAN The meaning of can be found in the previous description. UE-RAN is the transmission delay between the UE and the RAN. Since the second time adjustment information can be a moment or a time range, the third moment can also be a time range.

[0218] S807, SMF sends the third time to RAN, where the third time is used by RAN to schedule a message for the downlink service.

[0219] Step S807 is the same as S606. For details, please refer to the above description of S606, which will not be repeated here.

[0220] It should be noted that method 600 and method 800 can be used separately or in combination.

[0221] Fig.10 This is another downlink transmission method provided by the present application. The method 1000 is described below.

[0222] S1001, SMF sends the estimated time when the downlink service message arrives at RAN to RAN. Correspondingly, RAN receives the estimated time when the downlink service message arrives at RAN from SMF.

[0223] Before the SMF sends the time when the downlink service message is expected to arrive at the RAN, the SMF first needs to determine the time when the downlink service message is expected to arrive at the RAN. The way in which the SMF determines the time when the downlink service message is expected to arrive at the RAN can refer to the description in step S601 in method 600 above, and will not be repeated here.

[0224] S1002: The RAN determines first-time adjustment information according to the time at which the downlink service message is expected to arrive at the RAN and the configuration information of the radio resources.

[0225] Optionally, in one method, the RAN may determine a first delay based on a time when the downlink service is expected to arrive at the RAN and configuration information of wireless resources, wherein the first delay is the length of time between a time when the RAN expects the downlink service message to arrive at the RAN and a time when the downlink service message is expected to arrive at the RAN, wherein the time when the RAN expects the downlink service message to arrive at the RAN is within a first scheduling window, wherein a next scheduling window adjacent to the first scheduling window is a downlink scheduling window; then, the RAN determines the first time adjustment information based on the first delay.

[0226] 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 and will not be repeated here.

[0227] The RAN determines the first time adjustment information according to the first delay, and the first time adjustment information may be the first delay. Alternatively, the first time adjustment information may be based on the first delay and the time t at which the downlink service message is expected to arrive at the RAN. RANya The fifth time is determined, where the fifth time is the time when the expected UPF sends the downlink service message. For example, the fifth time = t RANya +First delay+T UPF-RAN Alternatively, the first time adjustment information may be based on the first delay and the time t at which the downlink service message is expected to arrive at the UPF. UPFya The fifth time is determined, where the fifth time is the time when the expected UPF sends the downlink service message. For example, the fifth time = t UPFya +First delay, at this time RAN needs to obtain t from SMF UPFya Specifically, in step S1001, SMF sends t UPFya .

[0228] In another manner, the RAN may determine a second downlink scheduling window in which the RAN plans to schedule the downlink service message based on the time when the downlink service message is expected to arrive at the RAN and the configuration information of the wireless resources; then, the RAN determines a boundary of a third scheduling window based on the second downlink scheduling window, and the third scheduling window is a scheduling window previous to the second downlink scheduling window; finally, the RAN determines the first time adjustment information based on the boundary of the third scheduling window.

[0229] Regarding how the RAN determines the second downlink scheduling window in which the RAN plans to schedule the downlink service message according to the time when the downlink service message is expected to arrive at the RAN and the configuration information of the wireless resources, and determines the boundary of the third scheduling window according to the second downlink scheduling window, reference can be made to the description of how the SMF determines the second downlink scheduling window in which the RAN plans to schedule the downlink service message according to the time when the downlink service message is expected to arrive at the RAN and the configuration information of the wireless resources, and determines the boundary of the third scheduling window according to the second downlink scheduling window in step S601, which will not be repeated here.

[0230] After determining the boundary of the third scheduling window, the RAN may determine the first time adjustment information. For example, the RAN may first determine the first delay according to the boundary of the third scheduling window, and then determine the first time adjustment information according to the first delay. This can refer to the description of the SMF determining the first delay according to the boundary of the third scheduling window in step S601. For another example, the RAN may directly determine the first time adjustment information according to the boundary of the third scheduling window. For example, see Figure 5 , assuming that the downlink service message is expected to arrive at the RAN at time t RANya =t1, then the RAN can determine, based on the configuration information of the wireless resources and t1, that the second downlink scheduling window in which the RAN is expected to schedule the downlink service message is downlink scheduling window 2. Then, the time at which the downlink service message is expected to arrive at the RAN is in the third scheduling window, and the third scheduling window is the previous scheduling window of the second downlink scheduling window, that is, downlink scheduling window 1. The first time adjustment information can be the first delay, or the first time adjustment information can be the time length T2 (that is, the first delay) between the upper boundary of the downlink scheduling window 1 and t1 and t UPFya Or, the first time adjustment information can be t RANya , the first delay and T UPF-RAN The sum of the three, t UPFya and T UPF The meaning of can be found in the above description. Assume that the time t at which the downlink service message is expected to arrive at the RAN RANya = t2, then the SMF can determine that the second downlink scheduling window in which the RAN is expected to schedule the downlink service message is downlink scheduling window 3 according to the configuration information of the wireless resources and t2. Then, the time when the downlink service message is expected to arrive at the RAN is in the third scheduling window, and the third scheduling window is the previous scheduling window of the second downlink scheduling window, that is, the uplink scheduling window 1. The first time adjustment information can be the first delay, or the first time adjustment information can be [T3, T4] and t UPFya Or, the first time adjustment information may be [T3, T4], t RANya and T UPF-RANThe sum of the three, T3 is the time length between the lower boundary of the uplink scheduling window 1 and t2, and T4 is the time length between the upper boundary of the uplink scheduling window 2 and t2.

[0231] Since the first delay may be a time range and the first time adjustment information is determined according to the first delay, the first time adjustment information may be a moment or a time range. When the first delay is a time range, the first time adjustment information may be a time range determined by the RAN according to the first delay, or the RAN may determine a time range according to the first delay and then determine a moment within the time range as the first time adjustment information.

[0232] S1003, RAN sends the first time adjustment information to SMF.

[0233] S1004 to S1006, SMF sends the first time adjustment information to UPF, UPF determines the first time to send the downlink service message according to the first time adjustment information, and sends the downlink service message at the first time.

[0234] Steps S1004 to S1006 are the same as steps S602 to S604. For details, please refer to the description of S602 to S604, which will not be repeated here.

[0235] Optionally, the method may further include S1007 to S1008, which are the same as S605 to S606. For details, please refer to the description of S605 to S606, which will not be repeated here.

[0236] According to the downlink transmission method provided by the present application, the RAN can determine the time adjustment information according to the time when the downlink service message is expected to arrive at the RAN and the configuration information of the wireless resources, and can provide the time adjustment information to the SMF. The SMF can adjust the time when the UPF sends the downlink service message according to the time adjustment information, and then the UPF can send the downlink service message at the adjusted time, so that the time when the downlink service message arrives at the RAN can be within the first scheduling window of the RAN, and the downlink service message can be scheduled in the second downlink scheduling window, and the second downlink scheduling window is the next scheduling window adjacent to the first scheduling window. Therefore, it is beneficial to reduce the scheduling waiting delay of the access network element scheduling the downlink service, and then it is beneficial to ensure the end-to-end delay requirement of the downlink service message.

[0237] Fig.11 This is another downlink transmission method provided by the present application. The method 1100 is described below.

[0238] S1101, SMF sends the estimated time when the downlink service message arrives at RAN to RAN. Correspondingly, RAN receives the estimated time when the downlink service message arrives at RAN from SMF.

[0239] This step is the same as S1001. Please refer to the above description of S1001 and will not be repeated here.

[0240] S1102: The RAN determines second time adjustment information according to the time at which the downlink service message is expected to arrive at the RAN and the configuration information of the radio resources.

[0241] Exemplarily, the RAN may determine the first delay according to the time when the downlink service message is expected to arrive at the RAN and the configuration information of the radio resources, and then determine the second time adjustment information according to the first delay. For how to determine the first delay, please refer to the description in step S801 above, which will not be repeated here.

[0242] The RAN determines second time adjustment information according to the first time delay, and the second time adjustment information may be the first time delay.

[0243] Exemplarily, if the second time adjustment information is the first delay, the RAN may indicate to the SMF whether the first delay is an advance amount or a lag amount. For example, if the first delay is determined according to the boundary of the third scheduling window, the first delay is a lag amount; if the first delay is determined according to the boundary of the sixth scheduling window, the first delay is an advance amount.

[0244] Optionally, the RAN may provide additional indications to the SMF only when the first delay is a lag amount; when there is no additional indication, the first delay is an advance amount.

[0245] Optionally, the RAN may also provide the SMF with both an advanced first delay and a delayed first delay for the SMF to select.

[0246] Since the first delay can be a time range, and the second time adjustment information is determined based on the first delay, the second time adjustment information can be a moment or a time range. When the first delay is a time range, the second time adjustment information can be a time range determined by the RAN based on the first delay, or the RAN can determine a time range based on the first delay and then determine a moment within the time range as the second time adjustment information based on the time range. S1103, the RAN sends the second time adjustment information to the SMF.

[0247] Exemplarily, if the second time adjustment information is the first delay, the RAN may indicate to the SMF whether the second time adjustment information is an advance amount or a lag amount. For example, if the second time adjustment information is determined according to the boundary of the third scheduling window, the second time adjustment information is a lag amount; if the second time adjustment information is determined according to the boundary of the sixth scheduling window, the second time adjustment information is an advance amount.

[0248] Optionally, the RAN may provide an additional indication to the SMF only when the second time adjustment information is a lag amount; when there is no additional indication, the second time adjustment information is an advance amount.

[0249] Optionally, the RAN may also provide the SMF with both the advanced second time adjustment information and the delayed second time adjustment information for the SMF to select.

[0250] S1104 to S1107, SMF sends the second time adjustment information to AF, and AF determines the second time when AS sends the downlink service message according to the second time adjustment information. Then, AF sends the second time to AS, and AS can send the downlink service message at the second time.

[0251] 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, which will not be repeated here.

[0252] Optionally, the method may further include S1108 to S1109, which are the same as S806 to S807. For details, please refer to the above description of S806 to S807, which will not be repeated here.

[0253] According to the downlink transmission method provided by the present application, the RAN can determine the time adjustment information according to the time when the downlink service message is expected to arrive at the RAN and the configuration information of the wireless resources, and can provide the time adjustment information to the AF through the SMF. The AF can adjust the time when the AS sends the downlink service message according to the time adjustment information, and then the AS can send the downlink service message at the adjusted time, so that the time when the downlink service message arrives at the RAN can be within the first scheduling window of the RAN, and the downlink service message can be scheduled in the second downlink scheduling window, and the second downlink scheduling window is the next scheduling window adjacent to the first scheduling window. Thereby, it is beneficial to reduce the scheduling waiting delay of the access network element to schedule the downlink service, and further beneficial to ensure the end-to-end delay requirement of the message of the downlink service.

[0254] Fig.12 This is another downlink transmission method provided by the present application. The method 1200 is described below.

[0255] S1201, SMF obtains first information, where the first information includes configuration information of wireless resources and a time when a downlink service is expected to arrive at the RAN.

[0256] For the specific content of the configuration information of the wireless resource and how the SMF obtains the configuration information of the wireless resource, please refer to the description in step S601 above, which will not be repeated here.

[0257] S1202, SMF sends the first information to UPF.

[0258] S1203, UPF determines a first moment according to the first information.

[0259] The time (referred to as the third time) when the downlink service message sent by the UPF at the first time arrives at the RAN is within the first scheduling window of the RAN, wherein the next scheduling window adjacent to the first scheduling window is the downlink scheduling window. That is, the UPF will send the downlink service message at the first time, so that the downlink service message 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.

[0260] For example, the UPF may determine first time adjustment information based on the first information, and then determine the first moment based on the first time adjustment information.

[0261] The method by which UPF determines the first time adjustment information based on the first information is the same as the method by which SMF in S601 determines the first delay based on the configuration information of the wireless resource and the time when the downlink service is expected to arrive at the RAN. Please refer to the description of S601 and will not be repeated here.

[0262] In addition, how the UPF specifically determines the first moment according to the first time adjustment information can be referred to the description in S603, which will not be repeated here.

[0263] Optionally, the UPF may cache the downlink message of the first service according to the first time adjustment information, and the cache duration is the time length indicated by the first time adjustment information.

[0264] S1204, UPF sends the downlink service at the first moment.

[0265] According to the downlink transmission method provided by the present application, the UPF can determine the sending time of the downlink service message according to the first information provided by the SMF, so that the time when the downlink service message arrives at the RAN can be within the first scheduling window of the RAN, and the downlink service message can be scheduled in the second downlink scheduling window, and the second downlink scheduling window is the next scheduling window adjacent to the first scheduling window. Therefore, it is beneficial to reduce the scheduling waiting delay of the access network element scheduling the downlink service, and further to ensure the end-to-end delay of the downlink service message.

[0266] Optionally, the method may further include:

[0267] S1205, UPF sends the second information to SMF. Correspondingly, SMF receives the second information from UPF.

[0268] The second information is the first moment or the waiting or caching delay of the downlink service in the UPF.

[0269] S1206, SMF determines the third time according to the second information.

[0270] S1207, SMF sends the third time to RAN. The third time is used by RAN to schedule downlink services.

[0271] In S1206, for example, if the second information is the waiting or buffering delay of the downlink service in the UPF, the third moment may be the sum of the moment when the downlink service reaches the UPF, the second information, and the transmission delay from the UPF to the RAN. For example, if the second information is the first moment, the third moment may be the sum of the first moment and the transmission delay from the UPF to the RAN.

[0272] Step S1207 is the same as step S606, and the description of step S606 may be referred to, which will not be repeated here.

[0273] It should be noted that if the SMF obtains the second information by other means, steps S1206 to S1207 are also applicable and will not be described further in this application.

[0274] It should be noted that in this application, since the downlink service can be a periodic service, the time for sending or scheduling the downlink service message can refer to the starting time of sending the downlink service message, and each subsequent network element periodically sends or schedules the downlink service message according to this time.

[0275] It should be understood that the various schemes of the embodiments of the present application can be used in reasonable combination, and the explanations or descriptions of the various terms appearing in the embodiments can be mutually referenced or explained in the various embodiments, without limitation.

[0276] It should also be understood that in various embodiments of the present application, the size of the sequence number of each process does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic. The various digital numbers or sequence numbers involved in the above-mentioned processes are only for the convenience of description and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0277] Above, combined Figures 5 to 12 The method provided by the embodiment of the present application is described in detail. Figures 13 to 15 The device provided in the embodiments of the present application is described in detail.

[0278] Fig.13 is a schematic block diagram of a communication device provided in an embodiment of the present application. Fig.13 As shown, the communication device 2000 may include a transceiver unit 2010 and a processing unit 2020 .

[0279] The transceiver unit 2010 may be used to send information to other devices or receive information from other devices, for example, to send or receive time adjustment information (eg, first time adjustment information). The processing unit 1200 may be used to perform internal processing of the device, for example, to obtain a first delay.

[0280] In one implementation, the communication device 2000 corresponds to the session management network element (eg, SMF) in the above method. The communication device 2000 may be a session management network element or a chip configured in the session management network element, which may include a unit for executing the operations performed by the session management network element.

[0281] In one example, the communication device 2000 corresponds to the session management network element in the above-mentioned method 600 or 800.

[0282] The processing unit 2020 is used to obtain a first delay, where the first delay is the time length between the moment when the expected downlink service message arrives at the access network element and the moment when the downlink service message is expected to arrive at the access network element, wherein the moment when the expected downlink service message arrives at the access network element is within a first scheduling window, wherein the next scheduling window adjacent to the first scheduling window is a downlink scheduling window; the transceiver unit 2010 is used to send time adjustment information related to the first delay to the first network element, the first network element is a user plane network element or an application network element, and the time adjustment information is used to determine the first moment when the user plane network element sends the downlink service message, or is used by the application server to determine the second moment when the downlink service message is sent, wherein the third moment when the downlink service message sent by the user plane network element at the first moment or the application server at the second moment arrives at the access network element is within the first scheduling window.

[0283] Optionally, the processing unit 2020 is specifically used to: obtain the configuration information of the wireless resources of the access network element and the time when the downlink service message is expected to arrive at the access network element; determine the first delay based on the configuration information of the wireless resources and the time when the downlink service message is expected to arrive at the access network element.

[0284] Optionally, the processing unit 2020 is specifically used to: determine a second downlink scheduling window in which the access network element is expected to schedule the downlink service message based on the configuration information of the wireless resources and the time when the downlink service message is expected to arrive at the access network element; determine a boundary of a third scheduling window based on the configuration information of the wireless resources and the second downlink scheduling window, the third scheduling window being the previous scheduling window of the second downlink scheduling window; and determine the first delay based on the boundary of the third scheduling window.

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

[0286] Optionally, the processing unit 2020 is specifically used to: obtain the time when the downlink service message is expected to arrive at the access network network element; the transceiver unit 2010 is also used to: send the time when the downlink service message is expected to arrive at the access network network element to the access network network element, and receive the first delay from the access network network element.

[0287] Optionally, the processing unit 2020 is specifically used to: determine the time when the downlink service message is expected to arrive at the access network element based on the transmission delay from the user plane network element to the access network element and the time when the downlink service message is expected to arrive at the user plane network element; or, obtain the quality of service QoS information of the downlink service from the policy control network element, and determine the time when the downlink service message is expected to arrive at the access network element based on the QoS information.

[0288] Optionally, when the first network element is the user plane network element, the time adjustment information is the first delay or a fourth time determined based on the first delay and the time when the downlink service message is expected to arrive at the user plane network element.

[0289] Optionally, in the case where the first network element is the application network element, the time adjustment information includes one or more of the following: the first delay, the time when the expected downlink service message arrives at the user plane network element determined based on the first delay, and the time when the expected downlink service message arrives at the terminal device determined based on the first delay.

[0290] Optionally, the processing unit 2020 is further used to determine the third moment according to the time adjustment information; the transceiver unit 2010 is further used to send the third moment to the access network element, and the third moment is used by the access network element to schedule the downlink service message.

[0291] In another example, the communication device 2000 corresponds to the session management network element in the above method 1200.

[0292] Specifically, the processing unit 2020 is used to obtain first information, wherein the first information includes configuration information of wireless resources and a time when a downlink service message is expected to arrive at an access network element; the transceiver unit 2010 is used to send the first information to a user plane network element, wherein the first information is used to determine a first time when the user plane network element sends the downlink service message, wherein a third time when the downlink service message sent at the first time arrives at the access network element is within a first scheduling window of the access network element, wherein a next scheduling window adjacent to the first scheduling window is a downlink scheduling window.

[0293] Optionally, the configuration information of the wireless resources includes a time slot start time, a time slot duration, an uplink and downlink time slot ratio, and a scheduling processing delay of the access network element.

[0294] Optionally, the transceiver unit 2010 is further configured to receive second information from the user plane network element, where the second information is the first moment or the waiting delay of the downlink service message in the user plane network element; the processing unit 2020 is further configured to determine the third moment according to the second information. The transceiver unit 2010 is further configured to send the third moment to the access network element.

[0295] It should be understood that the communication device 2000 can also correspond to the session management network element in the above methods 1000 and 1100. The specific operations performed by the communication device 2000 can refer to the description of the session management network element in the above methods 1000 and 1100, which will not be repeated here.

[0296] In one implementation, the communication device 2000 corresponds to the user plane network element (eg, UPF) in the above method. The communication device 2000 may be a user plane network element or a chip configured in the user plane network element, which may include a unit for executing operations performed by the user plane network element.

[0297] In one example, the communication device 2000 corresponds to the user plane network element in the above-mentioned method 600 or 800.

[0298] Specifically, the transceiver unit 2010 is used to receive time adjustment information related to a first delay from a session management network element, wherein the first delay is the time length between the moment when the expected downlink service message arrives at the access network element and the moment when the downlink service message is expected to arrive at the access network element, wherein the moment when the expected downlink service message arrives at the access network element is within a first scheduling window, wherein the next scheduling window adjacent to the first scheduling window is a downlink scheduling window; the processing unit 2020 is used to determine, based on the time adjustment information, a first moment when the communication device 2000 sends the downlink service message, wherein a third moment when the downlink service message sent at the first moment arrives at the access network element is within the first scheduling window.

[0299] Optionally, the time adjustment information is the first time delay or a fourth time determined based on the first time delay and the time when the downlink service message is expected to arrive at the communication device 2000.

[0300] In one example, the communication device 2000 corresponds to the user plane network element in the above method 1200.

[0301] Specifically, the transceiver unit 2010 is used to receive first information from a session management network element, wherein the first information includes configuration information of wireless resources and a time when a downlink service message is expected to arrive at an access network element; the processing unit 2020 is used to determine a first time for sending the downlink service message based on the first information, wherein a third time when the downlink service message sent at the first time arrives at the access network element is within a first scheduling window of the access network element, wherein a next scheduling window adjacent to the first scheduling window is a downlink scheduling window.

[0302] Optionally, the configuration information of the wireless resources includes a time slot start time, a time slot duration, an uplink and downlink time slot ratio, and a scheduling processing delay of the access network element;

[0303] Optionally, the processing unit 2020 is specifically used to: determine a first delay based on the first information, the first delay being the length of time between the moment when the downlink service message is expected to arrive at the access network element and the moment when the downlink service message is expected to arrive at the access network element; determine the first moment based on the first delay.

[0304] Optionally, the transceiver unit 2010 is further used to: send second information to the session management network element, where the second information is the first moment or the waiting delay of the downlink service in the communication device 2000. The second information is used to determine the third moment.

[0305] It should be understood that the communication device 2000 can also correspond to the user plane network element in the above methods 1000 and 1100. The specific operations performed by the communication device 2000 can refer to the description of the user plane network element in the above methods 1000 and 1100, which will not be repeated here.

[0306] In one implementation, the communication device 2000 corresponds to the application network element (eg, AF) in the above method. The communication device 2000 may be an application network element or a chip configured in an application network element, which may include a unit for executing operations executed by the application network element.

[0307] In one example, the communication device 2000 corresponds to the application network element in the above-mentioned method 800.

[0308] Specifically, the transceiver unit 2010 is used to receive time adjustment information related to a first delay from a session management network element, wherein the first delay is the time length between the moment when the expected downlink service message arrives at the access network element and the moment when the downlink service message is expected to arrive at the access network element, wherein the moment when the expected downlink service message arrives at the access network element is within a first scheduling window, wherein the next scheduling window adjacent to the first scheduling window is a downlink scheduling window; the processing unit 2020 is used to determine a second moment when the application server sends the downlink service message according to the time adjustment information, wherein a third moment when the downlink service message sent at the second moment arrives at the access network element is within the first scheduling window.

[0309] Optionally, the time adjustment information includes one or more of the following: the first delay, the time when the expected downlink service message arrives at the user plane network element based on the first delay, and the time when the expected downlink service message arrives at the terminal device based on the first delay.

[0310] It should be understood that the communication device 2000 can also correspond to the application network element in the above method 1100. The specific operations performed by the communication device 2000 can refer to the description of the application network element in the above method 1100, which will not be repeated here.

[0311] In one implementation, the communication device 2000 corresponds to the access network element (e.g., RAN) in the above method. The communication device 2000 may be an access network element or a chip configured in an access network element, which may include a unit for executing operations performed by the access network element.

[0312] In one example, the communication device 2000 corresponds to the access network element in the above-mentioned method 600 or 800.

[0313] Specifically, the transceiver unit 2010 is used to determine the time when the downlink service message received from the session management network element is expected to arrive at the communication device 2000; the processing unit 2020 is used to determine a first delay according to the time when the downlink service message is expected to arrive at the communication device 2000, the first delay being the time length between the time when the communication device 2000 expects the downlink service message to arrive at the communication device 2000 and the time when the downlink service message is expected to arrive at the communication device 2000, wherein the time when the communication device 2000 expects the downlink service message to arrive at the communication device 2000 is within a first scheduling window, wherein the next scheduling window adjacent to the first scheduling window is a downlink scheduling window; the transceiver unit 2010 is also used to send the first delay to the session management network element, the first delay being used by the session management network element to adjust the time when the user plane network element and / or the application server sends the downlink service message.

[0314] Optionally, the processing unit 2020 is specifically used to determine the first delay according to the time when the downlink service message is expected to arrive at the communication device 2000 and the configuration information of the wireless resources of the communication device 2000.

[0315] Optionally, the configuration information of the wireless resources includes a time slot start time, a time slot duration, an uplink and downlink time slot ratio, and a scheduling processing delay of the communication device 2000 .

[0316] Optionally, the processing unit 2020 is specifically used to: determine a second downlink scheduling window in which the communication device 2000 is expected to schedule the downlink service based on the configuration information of the wireless resources and the time when the downlink service message is expected to arrive at the communication device 2000; determine a boundary of a third scheduling window based on the configuration information of the wireless resources and the second downlink scheduling window, the third scheduling window being the previous scheduling window of the second downlink scheduling window; and determine the first delay based on the boundary of the third scheduling window.

[0317] In one example, the communication device 2000 corresponds to the access network element in the above-mentioned method 1000 or 1100.

[0318] Specifically, the transceiver unit 2010 is used to receive the time when the downlink service message is expected to arrive at the communication device 2000 from the session management network element; the processing unit 2020 is used to determine the time adjustment information according to the time when the downlink service message is expected to arrive at the communication device 2000 and the configuration information of the wireless resources; the transceiver unit 2010 is also used to send 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 the time when the user plane network element and / or the application server sends the downlink service message.

[0319] Optionally, the processing unit 2020 is specifically used to: determine a first delay based on the moment when the downlink service is expected to arrive at the communication device 2000 and the configuration information of the wireless resources, the first delay being the length of time between the moment when the communication device 2000 expects the downlink service message to arrive at the communication device 2000 and the moment when the downlink service message is expected to arrive at the communication device 2000, wherein the moment when the communication device 2000 expects the downlink service message to arrive at the communication device 2000 is within a first scheduling window, wherein the next scheduling window adjacent to the first scheduling window is a downlink scheduling window; determine the time adjustment information based on the first delay.

[0320] Optionally, the processing unit 2020 is specifically used to: determine a second downlink scheduling window in which the communication device 2000 is expected to schedule the downlink service message according to the time when the downlink service message is expected to arrive at the communication device 2000 and the configuration information of the wireless resources; determine a boundary of a third scheduling window according to the second downlink scheduling window, the third scheduling window being the previous scheduling window of the second downlink scheduling window; and determine the time adjustment information according to the boundary of the third scheduling window.

[0321] Optionally, the configuration information of the wireless resources includes a time slot start time, a time slot duration, an uplink and downlink time slot ratio, and a scheduling processing delay of the communication device 2000 .

[0322] It should be understood that the communication device 2000 can also correspond to the access network element in the above method 1200. The specific operations performed by the communication device 2000 can refer to the description of the access network element in the above method 1200, which will not be repeated here.

[0323] It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0324] It should also be 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 in the communication device 2000 may correspond to Fig.14 The communication interface 3200 in the communication device 3000 shown in FIG. 2000 may correspond to the processing unit 2020 in the communication device 2000. Fig.14 When the communication device 2000 corresponds to an access network element, the transceiver unit 2010 in the communication device 2000 may also correspond to Fig.15 The transceiver 4200 in the network device 4000 shown in FIG. 4 may also correspond to the processing unit 2020 in the communication device 2000 Fig.15 Processor 4100 in network device 4000 shown in FIG.

[0325] Fig.14 2 shows a schematic block diagram of another communication device 3000 provided by the present application. Any network element involved in the above method embodiment, such as a session management network element, an application network element, a user plane network element, an access network element, etc., can be implemented by Fig.14 The communication device shown is implemented.

[0326] It should be understood that the communication device 3000 may be a physical device, a component of a physical device (eg, an integrated circuit, a chip, etc.), or a functional module in a physical device.

[0327] like Fig.14 As shown, the communication device 3000 includes: one or more processors 3100. The processor 3100 can store execution instructions for executing the method of the embodiment of the present application. Optionally, the communication interface 3200 can be called in the processor 3100 to implement the receiving and sending functions. The communication interface 3200 can be a logical interface or a physical interface, which is not limited. For example, the communication interface 3200 can be a transceiver circuit, an interface circuit, a transceiver, or a transceiver circuit for implementing the receiving and sending functions. The sending function and the receiving function of the communication interface 3200 can be separate or integrated. The above-mentioned transceiver circuit or interface circuit can be used for reading and writing code / data, or the above-mentioned transceiver circuit or interface circuit can be used for transmission or transfer of signals.

[0328] Optionally, the communication device 3000 may further include a memory 3300. The embodiment of the present application does not specifically limit the specific deployment location of the memory 3300, and the memory 3300 may be integrated into the processor 3100 or may be independent of the processor 3100. In the case where 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 deployed in other locations (e.g., a cloud system).

[0329] The processor 3100 , the memory 3300 and the communication interface 3200 communicate with each other through internal connection paths to transfer control and / or data signals.

[0330] It is understandable that, although not shown, the communication device 3000 may also include other devices, such as an input device, an output device, a battery, etc.

[0331] Optionally, in some embodiments, the memory 3300 may store execution instructions for executing the method of the embodiment of the present application. The processor 3100 may execute the instructions stored in the memory 3300 in combination with other hardware (e.g., the communication interface 3200) to complete the steps of the method execution shown below. The specific working process and beneficial effects can be found in the description of the method embodiment above.

[0332] The method disclosed in the embodiment of the present application can be applied to the memory 3300, or implemented by the memory 3300. The memory 3300 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the method can be completed by an integrated logic circuit of hardware in the processor or an instruction in the form of software. The above-mentioned processor can be a general-purpose processor, a digital signal processor (digital signal processor, DSP), an application specific integrated circuit (application specific integrated circuit, ASIC), a field programmable gate array (field programmable gate array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in conjunction with the embodiment of the present application can be directly embodied as a hardware decoding processor for execution, or a combination of hardware and software modules in the decoding processor for execution. The software module can be located in a mature storage medium in the field such as random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory or electrically erasable programmable memory, register, etc. The storage medium is located in the memory, and the processor reads the instructions in the memory and completes the steps of the above method in combination with its hardware.

[0333] It is understood that the memory 3300 can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory ROM, a programmable read-only memory (programmable ROM, PROM), an erasable programmable read-only memory (erasable PROM, EPROM), an electrically erasable programmable read-only memory (electrically EPROM, EEPROM) or a flash memory. The volatile memory can be a random access memory RAM, which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (static RAM, SRAM), dynamic random access memory (dynamic RAM, DRAM), synchronous dynamic random access memory (synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhancedSDRAM, ESDRAM), synchronous connection dynamic random access memory (synchlink DRAM, SLDRAM) and direct memory bus random access memory (direct rambus RAM, DR RAM). It should be noted that memory of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

[0334] Fig.15 4000 is a schematic diagram of the structure of a network device provided in an embodiment of the present application, for example, a schematic diagram of the structure of a base station. The network device 4000 can be applied to Figure 1 or Figure 2 In the system shown, the functions of the access network element in the above method embodiment are performed. Fig.15 As shown, 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 (BBU) (also referred to as distributed units (DU)) 4200. The RRU 4100 may be referred to as a transceiver unit or a communication unit. Fig.134100 corresponds to the transceiver unit 2010 in . Optionally, the transceiver unit 4100 can also be called a transceiver, a transceiver circuit, or a transceiver, etc., which 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 sending unit, the receiving unit may correspond to a receiver (or a receiver, a receiving circuit), and the sending unit may correspond to a transmitter (or a transmitter, a transmitting circuit). The RRU4100 part is mainly used for the reception and transmission of radio frequency signals and the conversion of radio frequency signals and baseband signals. The BBU 4200 part is mainly used for baseband processing, controlling network equipment, etc. The RRU 4100 and BBU4200 may be physically arranged together or physically separated, that is, a distributed base station.

[0335] The BBU 4200 is the control center of the network device, which can also be called a processing unit. Fig.13 The processing unit 2020 in the embodiment corresponds to the baseband processing unit 2020, which is mainly used to complete baseband processing functions, such as channel coding, multiplexing, modulation, spread spectrum, etc. For example, the BBU (processing unit) can be used to control the network device to execute the operation flow of the access network device in the above method embodiment.

[0336] In one example, the BBU 4200 may be composed of one or more single boards, and the multiple single boards may jointly support a wireless access network of a single access standard (such as an LTE network), or may respectively support wireless access networks of different access standards (such as an LTE network, a 5G network, or other networks). The BBU 4200 also includes a memory 4201 and a processor 4202. The memory 4201 is used to store necessary instructions and data. The processor 4202 is used to control the network device to perform necessary actions, for example, to control the network device to execute the operation process of the access network device in the above method embodiment. The memory 4201 and the processor 4202 can serve one or more single boards. In other words, a memory and a processor may be separately set on each single board. It is also possible that multiple single boards share the same memory and processor. In addition, necessary circuits may be set on each single board.

[0337] It should be understood that Fig.15 The network device 4000 shown can implement various processes involving access network devices in the aforementioned method embodiments. The operations or functions of each module in the network device 4000 are respectively to implement the corresponding processes in the aforementioned method embodiments. For details, please refer to the description in the aforementioned method embodiments. To avoid repetition, detailed description is appropriately omitted here.

[0338] The BBU 4200 can be used to perform the actions implemented by the access network device in the previous method embodiment, and the RRU 4100 can be used to perform the actions of the access network device sending to or receiving from the terminal device in the previous method embodiment. Please refer to the description in the previous method embodiment for details, which will not be repeated here.

[0339] The present application also provides a computer program product, which includes: computer program code, when the computer program code is run on a computer, enables the computer to execute the method of the session management network element, application network element, user plane network element or access network element side in any of the aforementioned method embodiments.

[0340] The present application also provides a computer-readable medium storing a program code. When the program code runs on a computer, the computer executes the method on the session management network element, application network element, user plane network element or access network element side in the aforementioned method embodiment.

[0341] The present application also provides a system, which includes one or more of the aforementioned session management network element, application network element, user plane network element, and access network element. Optionally, the system may also include the aforementioned terminal device.

[0342] An embodiment of the present application also provides a processing device, including a processor and an interface; the processor is used to execute the communication method in any of the above method embodiments.

[0343] It should be understood that the above-mentioned processing device can be a chip. For example, the processing device can 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) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processing circuit (DSP), a microcontroller unit (MCU), a programmable logic device (PLD) or other integrated chips. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiments of the present application can be directly embodied as a hardware decoding processor to be executed, or the hardware and software modules in the decoding processor are combined to be executed. The software module can be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0344] It can be understood that the memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can 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 can be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0345] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is 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 computer-readable storage medium, for example, the computer instructions may be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a high-density digital video disc (DVD)), or a semiconductor medium (eg, a solid state disc (SSD)).

[0346] The network devices in the above-mentioned various device embodiments completely correspond to the network devices or terminal devices in the terminal devices and method embodiments, and the corresponding modules or units perform the corresponding steps. For example, the communication unit (transceiver) performs the steps of receiving or sending in the method embodiment, and other steps except sending and receiving can be performed by the processing unit (processor). The functions of the specific units can refer to the corresponding method embodiments. Among them, the processor can be one or more.

[0347] The terms "component", "module", "system", etc. used in this specification are used to represent computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, or a computer. By way of illustration, both applications running on a computing device and a computing device can be components. One or more components may reside in a process or an execution thread, and a component may be located on a computer or distributed between two or more computers. In addition, these components may be executed from various computer-readable media having various data structures stored thereon. Components may communicate, for example, through local or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system, or a network, such as the Internet interacting with other systems through signals).

[0348] It should be understood that the "embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, the various embodiments in the entire specification do not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner.

[0349] It should be understood that in the embodiments of the present application, the numbers "first", "second"... are only for distinguishing different objects, such as distinguishing different network devices, and do not constitute a limitation on the scope of the embodiments of the present application. The embodiments of the present application are not limited to this.

[0350] It should also be understood that in the present application, "when", "if" and "if" all mean that the network element will take corresponding actions under certain objective circumstances, and do not limit the time, nor do they require the network element to have a judgment action when implementing it, nor do they mean that there are other limitations.

[0351] It should also be understood that, in the present application, “at least one” means one or more, and “more than one” means two or more.

[0352] It should also be understood that in each embodiment of the present application, "A corresponds to B" means that B is associated with A, and B can be determined according to A. However, it should also be understood that determining B according to A does not mean determining B only according to A, and B can also be determined according to A and / or other information.

[0353] It should also be understood that the term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0354] The meaning of expressions similar to "the project includes one or more of the following: A, B, and C" in this application, unless otherwise specified, generally means that the project can be any 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. The above is an example of three elements, A, B and C, to illustrate the optional items of the project. When it is expressed as "the project includes at least one of the following: A, B, ..., and X", that is, when there are more elements in the expression, the items that can be applied to the project can also be obtained according to the above rules.

[0355] It is understandable that in the embodiment of the present application, the terminal device and / or the network device can perform some or all of the steps in the embodiment of the present application, and these steps or operations are only examples. The embodiment of the present application can also perform other operations or variations of various operations. In addition, each step can be performed in a different order presented in the embodiment of the present application, and it is possible not to perform all the operations in the embodiment of the present application.

[0356] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0357] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0358] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0359] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0360] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0361] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage media include: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories ROM, random access memories RAM, magnetic disks or optical disks.

[0362] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A downlink transmission method, characterized in that: include: The session management network element acquires a first delay, where the first delay is a time length between a time when a downlink service message is expected to arrive at an access network element and a time when the downlink service message is expected to arrive at the access network element, wherein the time when the expected downlink service message arrives at the access network element is within a first scheduling window, wherein a next scheduling window adjacent to the first scheduling window is a downlink scheduling window; The session management network element sends the first delay to the application network element, and the first delay is used by the application network element to determine a second time to send the downlink service message, wherein a third time when the downlink service message sent at the second time arrives at the access network element is within the first scheduling window.

2. The method according to claim 1, characterized in that The session management network element obtains a first delay, including: The session management network element obtains the configuration information of the radio resources of the access network element and the time when the downlink service message is expected to arrive at the access network element; The session management network element determines the first delay according to the configuration information of the wireless resources and the time when the downlink service message is expected to arrive at the access network element.

3. The method according to claim 2, characterized in that The session management network element determines the first delay according to the configuration information of the radio resource and the time when the downlink service is expected to arrive at the access network element, including: The session management network element determines, according to the configuration information of the radio resources and the time when the downlink service message is expected to arrive at the access network element, a second downlink scheduling window in which the access network element is expected to schedule the downlink service message; The session management network element determines, according to the configuration information of the radio resources and the second downlink scheduling window, a boundary of a third scheduling window, where the third scheduling window is a previous scheduling window of the second downlink scheduling window; The session management network element determines the first delay according to a boundary of the third scheduling window.

4. The method according to claim 2 or 3, characterized in that The configuration information of the wireless resources includes the time slot start time, the time slot duration, the uplink and downlink time slot ratio and the scheduling processing delay of the access network element.

5. The method according to claim 1, characterized in that The session management network element obtains a first delay, including: The session management network element obtains the time when the downlink service message is expected to arrive at the access network element; The session management network element sends the time at which the downlink service message is expected to arrive at the access network element to the access network element; The session management network element receives the first delay from the access network element.

6. The method according to claim 5, characterized in that The session management network element obtains the time when the downlink service message is expected to arrive at the access network element, including: The session management network element determines the time when the downlink service message is expected to arrive at the access network element according to the transmission delay from the user plane network element to the access network element and the time when the downlink service message is expected to arrive at the user plane network element.

7. The method according to claim 6, characterized in that The method further comprises: The session management network element receives the policy and charging control rules from the policy control network element, where the policy and charging control rules include the time when the downlink service message is expected to arrive at the user plane network element.

8. The method according to any one of claims 1 to 3 or any one of claims 5 to 7, characterized in that The method further comprises: The session management network element determines the third time according to the first time delay; The session management network element sends the third time to the access network element, and the third time is used by the access network element to schedule the downlink service message.

9. A method for downlink transmission, characterized in that: include: The application network element receives a first delay from the session management network element, where the first delay is the length of time between a time when the expected downlink service packet arrives at the access network element and a time when the downlink service packet is expected to arrive at the access network element, wherein the time when the expected downlink service packet arrives at the access network element is within a first scheduling window, wherein a next scheduling window adjacent to the first scheduling window is a downlink scheduling window; The application network element determines a second time instant for sending the downlink service message according to the first time delay, wherein a third time instant when the downlink service message sent at the second time instant arrives at the access network element is within the first scheduling window.

10. A method for downlink transmission, characterized in that: include: The time at which the access network element receives the estimated arrival time of the downlink service message from the session management network element; The access network element determines a first delay according to a time when the downlink service message is expected to arrive at the access network element, wherein the first delay is a time length between a time when the access network element expects the downlink service message to arrive at the access network element and a time when the downlink service message is expected to arrive at the access network element, wherein the time when the access network element expects the downlink service message to arrive at the access network element is within a first scheduling window, wherein a next scheduling window adjacent to the first scheduling window is a downlink scheduling window; The access network element sends the first delay to the session management network element, where the first delay is used to determine a second time instant for sending the downlink service message, and a third time instant when the downlink service message sent at the second time instant arrives at the access network element is within the first scheduling window.

11. The method according to claim 10, characterized in that The access network element determines a first delay according to a time when the downlink service message is expected to arrive at the access network element, including: The access network element determines the first delay according to the time when the downlink service message is expected to arrive at the access network element and the configuration information of the wireless resources of the access network element.

12. The method according to claim 11, characterized in that The configuration information of the wireless resources includes the time slot start time, the time slot duration, the uplink and downlink time slot ratio and the scheduling processing delay of the access network element.

13. The method according to claim 11 or 12, characterized in that: The access network element determines the first delay according to the time when the downlink service message is expected to arrive at the access network element and the configuration information of the radio resources of the access network element, including: The access network element determines, according to the configuration information of the radio resources and the time when the downlink service message is expected to arrive at the access network element, a second downlink scheduling window in which the access network element is expected to schedule the downlink service; The access network element determines, according to the configuration information of the radio resources and the second downlink scheduling window, a boundary of a third scheduling window, where the third scheduling window is a previous scheduling window of the second downlink scheduling window; The access network element determines the first delay according to a boundary of the third scheduling window.

14. A communication device, characterized in that: The apparatus comprises a module or unit for performing the method of any one of claims 1 to 8, claim 9, or any one of claims 10 to 13.

15. A communication device, characterized in that: include: A processor, the processor is coupled to a memory, the memory is used to store programs or instructions, when the program or instructions are executed by the processor, the device performs the method according to any one of claims 1 to 8, claim 9, or any one of claims 10 to 13.

16. A readable storage medium having a computer program or instruction stored thereon, characterized in that: When the computer program or instructions are executed, the computer performs the method according to any one of claims 1 to 8, claim 9, or any one of claims 10 to 13.

17. A computer program product, characterized in that The method comprises computer program instructions which cause a computer to execute the method according to any one of claims 1 to 8, claim 9, or any one of claims 10 to 13.

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