WO2020103540A1 - 同步的方法和装置 - Google Patents

同步的方法和装置

Info

Publication number
WO2020103540A1
WO2020103540A1 PCT/CN2019/105142 CN2019105142W WO2020103540A1 WO 2020103540 A1 WO2020103540 A1 WO 2020103540A1 CN 2019105142 W CN2019105142 W CN 2019105142W WO 2020103540 A1 WO2020103540 A1 WO 2020103540A1
Authority
WO
WIPO (PCT)
Prior art keywords
message
ran
time
terminal device
network
Prior art date
Application number
PCT/CN2019/105142
Other languages
English (en)
French (fr)
Inventor
李永翠
李岩
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from CN201910032550.4A external-priority patent/CN111211852B/zh
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to EP19886237.7A priority Critical patent/EP3869858B1/en
Publication of WO2020103540A1 publication Critical patent/WO2020103540A1/zh
Priority to US17/326,033 priority patent/US11838106B2/en

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W28/00—Network traffic management; Network resource management
    • H04W28/16—Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
    • H04W28/24—Negotiating SLA [Service Level Agreement]; Negotiating QoS [Quality of Service]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements

Definitions

  • the present application relates to the field of communication, and more specifically, to a method and apparatus for synchronization in the field of communication.
  • TSN time sensitive network
  • 802.1AS protocol is used to achieve high precision time synchronization requirements.
  • the mobile network can also be applied to industrial scenarios, that is, the mobile network terminal needs to be synchronized with the TSN clock.
  • the present application provides a method and device for synchronization, which can achieve clock synchronization with TSN in a mobile network.
  • a method of synchronization is provided.
  • the method is performed by a first network element in a relay network.
  • the relay network includes a radio access network RAN device and a terminal device.
  • the method includes:
  • the first network element receives a clock synchronization message
  • the first network element determines a first time of the relay network, and the first time of the relay network includes a first downlink for transmitting the clock synchronization message between the RAN device and the terminal device Transmission delay;
  • the first network element determines a time correction field of the relay network, and the time correction field includes the first downlink transmission delay.
  • the first network element may determine the time correction domain of the relay network according to the clock synchronization message, where the time correction domain includes the first downlink corresponding to the transmission of the clock synchronization message between the RAN device and the terminal.
  • the transmission delay helps to realize the clock synchronization of the terminal device or the endpoint device with the external clock by using the TSN clock synchronization mechanism in the mobile network.
  • the clock synchronization message is used to trigger the first network element to determine the first time of the relay network.
  • the first network element recognizes that the received message is a SYNC message, it may trigger the determination of the residence time of the relay network.
  • the time correction field further includes a second downlink transmission delay between the node device that sends the clock synchronization message and the relay network.
  • the TSN clock synchronization mechanism can be used in the mobile network to synchronize the clock of the terminal device or the endpoint device with the external clock.
  • the relay network further includes a UPF, where the first time further includes a third downlink transmission between the UPF and the RAN device Delay.
  • the first network element when the relay network includes UPF, RAN, and terminal equipment, the first network element may be UPF, RAN, or terminal equipment.
  • the relay network when the relay network includes RAN and terminal equipment, the first network element may be RAN or terminal equipment.
  • the first time is the sum of the first downlink transmission delay and the third downlink transmission delay.
  • the first network element is the UPF
  • the first network element determines the first time of the relay network includes:
  • the UPF obtains the third downlink transmission delay
  • the UPF sends the clock synchronization message and first indication information to the RAN device, where the first indication information is used to instruct the RAN device to obtain the first downlink transmission delay;
  • the UPF receives the first downlink transmission delay from the RAN device
  • the UPF determines the first time according to the first downlink transmission delay and the third downlink transmission delay.
  • the RAN device receives the clock synchronization message and the first indication information sent by the UPF device, and determines the first downlink transmission delay according to the clock synchronization message and the first indication information, Then the RAN device sends the first downlink transmission delay to the UPF device.
  • the terminal device, RAN, and UPF are used as a relay network, and the UPF in the relay network determines the "internal delay" of the relay network transmitting the SYNC message, that is, it is received from the UPF.
  • the SYNC message when the terminal device receives the SYNC message, realizes the time synchronization between the terminal device (or the TSN endpoint device connected to the terminal device) and the TSN clock source.
  • the first indication information includes a first QFI
  • the first indication information is used to indicate that the RAN device receives a report corresponding to the first QFI At the time of writing, the first downlink transmission delay is obtained.
  • the first QFI is a special QFI, that is, the QoS flow message corresponding to the first QFI is a clock synchronization message, such as a SYNC message. That is, when the message received by the RAN includes the first QFI, the RAN can recognize the message as a SYNC message, and then can trigger the measurement of the first downlink transmission delay.
  • the first network element determining the first time of the relay network includes:
  • the first network element determines the first time of the relay network according to policy information, wherein the policy information is information configured on the first network element, or the second policy information is slave SMF The information received.
  • the first network element when the relay network includes a RAN device and a terminal device, the first network element may be a RAN at this time; and when the relay network includes a UPF device, a RAN device, and a terminal device, the first network element The network element may be a UPF device or a RAN device.
  • the first network element is the RAN device, and the first network element determines the first time of the relay network includes:
  • the RAN device receives second indication information, and the second indication information is used to instruct the RAN device to acquire the first time;
  • the RAN obtains the first downlink transmission delay and the third downlink transmission delay according to the second indication information
  • the RAN determines the first time according to the first downlink transmission delay and the third downlink transmission delay.
  • the terminal device, RAN, and UPF are used as a relay network, and the RAN in the relay network determines the "internal delay" of the relay network transmitting the SYNC message, that is, it is received from the UPF.
  • the SYNC message when the terminal device receives the SYNC message, realizes the time synchronization between the terminal device (or the TSN endpoint device connected to the terminal device) and the TSN clock source.
  • the second indication information includes a second QFI
  • the second indication information is used to indicate that the RAN device receives a report corresponding to the second QFI At the time of writing, the first time is obtained.
  • the QoS flow message corresponding to the second QFI is a clock synchronization message, that is, a SYNC message. That is to say, when the message received by the RAN includes the second QFI, the RAN can recognize the message as a SYNC message, and then can trigger the acquisition of the residence time of the relay network.
  • the first network element determining the first time includes:
  • the first network element determines the first time according to a frequency ratio between the first network element and the node device that sends the clock synchronization message.
  • the method further includes: the first network element sends a message to the terminal device, where the message carries the time correction field.
  • a method for synchronization is performed by a RAN device in a relay network, where the relay network includes a UPF device, the RAN device, and a terminal device.
  • the method includes:
  • the RAN device receives a clock synchronization message and first indication information sent by the UPF device, where the first indication information is used to instruct the RAN device to obtain a first downlink transmission delay, and the first downlink transmission
  • the time delay is the time delay for transmitting the clock synchronization message between the RAN device and the terminal device;
  • the RAN device determines the first downlink transmission delay according to the clock synchronization message and the first indication information
  • the RAN device sends the first downlink transmission delay to the UPF device.
  • the terminal device, RAN, and UPF are used as a relay network.
  • the UPF in the relay network determines the "internal delay" of the relay network transmitting the SYNC message, that is, it is received from the UPF SYNC message
  • the terminal device receives the SYNC message
  • it can trigger the RAN device to determine the first downlink transmission delay, thereby helping to realize the terminal device (or TSN endpoint device connected to the terminal device) and the TSN clock Source time synchronization.
  • the first indication information includes a first QFI
  • the first indication information is specifically used to indicate that the RAN device receives the corresponding In the message, the first downlink transmission delay is obtained.
  • a device for synchronization includes a module or unit for performing the method of synchronization in the first aspect or any possible implementation manner of the first aspect.
  • an apparatus for synchronization includes a module or unit for performing the method for synchronization in the second aspect or any possible implementation manner of the second aspect.
  • a device for synchronization includes a processor and a transceiver.
  • the processor is used to execute a program.
  • the processor and the transceiver implement the first aspect or any one of the first aspect. In a possible implementation manner.
  • the synchronized device may further include a memory, where the memory is used to store a program executed by the processor.
  • An example of the synchronized device is a RAN device, a UPF device, or a terminal device.
  • a device for synchronization includes a processor and a transceiver.
  • the processor is used to execute a program.
  • the processor and the transceiver implement the second aspect or any one of the second aspect. In a possible implementation manner.
  • the synchronized device may further include a memory, where the memory is used to store a program executed by the processor.
  • An example of this synchronized device is a RAN device.
  • a computer-readable storage medium stores a program code executed by a device for synchronization, and the program code includes any one of the possible aspects for implementing the first aspect or the first aspect. Instructions to implement the synchronized method in the mode.
  • a computer-readable storage medium stores a program code for execution by a device for synchronization, and the program code includes any one of the possible aspects for implementing the second aspect or the second aspect. Instructions to implement the synchronized method in the mode.
  • a chip includes a processor and a communication interface.
  • the communication interface is used for traveling with an external device.
  • the processor is used to implement the first aspect or any possible implementation manner of the first aspect. Method of synchronization.
  • the chip may further include a memory, the memory stores instructions, and the processor is used to execute the instructions stored in the memory, and when the instruction is executed, the processor is used to implement the first aspect or any one of the first aspect The method of synchronization in possible implementations.
  • the chip may be integrated on the RAN device, UPF device or terminal device.
  • a chip is provided.
  • the chip includes a processor and a communication interface.
  • the communication interface is used to communicate with an external device.
  • the processor is used to implement the second aspect or any possible implementation manner of the second aspect. Method of synchronization.
  • the chip may further include a memory, the memory stores instructions, and the processor is used to execute the instructions stored in the memory, and when the instruction is executed, the processor is used to implement the second aspect or any one of the second aspect The method of synchronization in possible implementations.
  • the chip may be integrated on the RAN device.
  • a method for sending a message including:
  • the communication network element receives a first packet, where the first packet includes a domain identifier, and the domain identifier is used to identify a clock domain to which the node device that sends the first packet belongs;
  • the communication network element determines the user plane connection corresponding to the first packet according to the correspondence between the domain identifier and the user plane connection identifier, and the domain identifier in the first packet;
  • the communication network element sends the first message to a terminal device through a user plane connection corresponding to the first message.
  • the method further includes:
  • the communication network element receives the correspondence between the domain identifier from the SMF and the user plane connection identifier.
  • the communication network element is UPF or RAN.
  • the first message is a clock synchronization message.
  • the user plane connection identifier includes at least one of the following: a session identifier and user plane tunnel information.
  • a method for sending a message including:
  • SMF determines the correspondence between the domain identifier and the user plane connection identifier, where the domain identifier is used to identify the clock domain to which the node device that sends the first message belongs;
  • the SMF sends the correspondence to the communication network element, where the correspondence is used by the communication network element to determine the user plane connection to send the first message to the terminal device.
  • the SMF determining the correspondence between the domain identifier and the user plane connection identifier includes:
  • the SMF obtains the correspondence between the terminal device identifier and the user plane connection identifier
  • the SMF obtains the correspondence between the terminal device ID and the domain ID, where the domain ID is used to identify the clock domain corresponding to the terminal device;
  • the SMF determines the correspondence between the domain ID and the user plane connection identifier according to the correspondence between the terminal device ID and the user plane connection ID, and the correspondence between the terminal device ID and the domain ID.
  • the SMF determining the correspondence between the domain identifier and the user plane connection identifier includes:
  • the SMF obtains the correspondence between the user plane connection identifier of the terminal device and the network identifier, where the network identifier is used to identify the network that the terminal device accesses;
  • the SMF obtains the correspondence between the network identifier and the domain identifier, and the domain identifier is used to identify the clock domain corresponding to the terminal device;
  • the SMF determines the correspondence between the domain identifier and the user plane connection identifier according to the correspondence between the user plane connection identifier and the network identifier, and the correspondence between the network identifier and the domain identifier.
  • the network identification includes at least one of the following: a data network name DNN, single network slice selection auxiliary information S-NSSAI.
  • the communication network element is UPF or RAN.
  • the first message is a clock synchronization message.
  • the user plane connection identifier includes at least one of the following: a session identifier and user plane tunnel information.
  • an apparatus for sending a message including a module or unit for performing the method for sending a message in the eleventh aspect or any one of the possible implementation manners of the eleventh aspect.
  • a device for sending a message including a module or a unit for performing the method for sending a message in the twelfth aspect or any possible implementation manner of the twelfth aspect.
  • an apparatus for sending a message includes a processor and a transceiver.
  • the processor is used to execute a program.
  • the processor and the transceiver implement the first aspect or the first aspect In any one of the possible implementations.
  • the synchronized device may further include a memory, where the memory is used to store a program executed by the processor.
  • An example of the device for sending a message is a RAN device or a UPF device.
  • an apparatus for sending a message includes a processor and a transceiver.
  • the processor is used to execute a program.
  • the processor and the transceiver implement the twelfth aspect or the tenth.
  • a method for sending a message in any possible implementation manner of the two aspects.
  • the device for sending a message may further include a memory, where the memory is used to store a program executed by the processor.
  • An example of the device for sending a message is an SMF device.
  • a computer-readable storage medium stores a program code executed by an apparatus for sending a message, the program code including the one for implementing the eleventh aspect or the eleventh aspect The instructions of the synchronization method in any possible implementation manner.
  • a computer-readable storage medium stores a program code executed by a device for sending a message, and the program code includes a program for implementing the twelfth aspect or the twelfth aspect.
  • the instructions of the synchronization method in any possible implementation manner.
  • a chip includes a processor and a communication interface.
  • the communication interface is used for peering with an external device.
  • the processor is used to implement the eleventh aspect or any one of the possible aspects of the eleventh aspect. The method of sending messages in the implementation.
  • the chip may further include a memory, the memory stores instructions, and the processor is used to execute the instructions stored in the memory.
  • the processor is used to implement the eleventh aspect or any of the eleventh aspect A method for sending a message in a possible implementation manner.
  • the chip may be integrated on the RAN device or UPF device.
  • a chip includes a processor and a communication interface, the communication interface is used to communicate with an external device, and the processor is used to implement the twelfth aspect or any one of the possible aspects of the twelfth aspect The method of sending messages in the implementation.
  • the chip may further include a memory, the memory stores instructions, and the processor is used to execute the instructions stored in the memory.
  • the processor is used to implement the twelfth aspect or any of the twelfth aspects A method for sending a message in a possible implementation manner.
  • the chip may be integrated on the SMF device.
  • FIG. 1 shows a schematic diagram of a network architecture applying the method of the embodiment of the present application.
  • FIG. 2 shows a principle diagram of a time synchronization method in 802.1AS.
  • FIG. 3 shows a schematic diagram of a scenario to which an embodiment of the present application is applied.
  • FIG. 4 shows a schematic diagram of another scenario to which the embodiment of the present application is applied.
  • FIG. 5 shows a schematic flowchart of a synchronization method provided by an embodiment of the present application.
  • FIG. 6 shows an example of a specific synchronization method provided by an embodiment of the present application.
  • FIG. 7 shows an example of a specific synchronization method provided by an embodiment of the present application.
  • FIG. 8 shows an example of a specific synchronization method provided by an embodiment of the present application.
  • FIG. 9 shows an example of a specific synchronization method provided by an embodiment of the present application.
  • FIG. 10 shows an example of a specific synchronization method provided by an embodiment of the present application.
  • FIG. 11 shows a schematic diagram of another time synchronization method.
  • FIG. 12 shows a schematic diagram of a method of frequency synchronization.
  • FIG. 13 shows a schematic diagram of a scenario to which an embodiment of the present application is applied.
  • FIG. 14 shows an example of a specific synchronization method provided by an embodiment of the present application.
  • FIG. 15 shows an example of a specific synchronization method provided by an embodiment of the present application.
  • FIG. 16 shows an example of identifying a clock synchronization message provided by an embodiment of the present application.
  • FIG. 17 shows a schematic block diagram of a communication device provided by an embodiment of the present application.
  • FIG. 18 shows a schematic block diagram of another communication device provided by an embodiment of the present application.
  • FIG. 19 shows a schematic flowchart of a packet sending method provided by an embodiment of the present application.
  • FIG. 20 shows a schematic flowchart of a method for sending a message provided by an embodiment of the present application.
  • FIG. 21 shows an example of sending a message provided by an embodiment of the present application.
  • FIG. 22 shows an example of sending a message provided by an embodiment of the present application.
  • FIG. 23 shows a schematic block diagram of a communication device provided by an embodiment of the present application.
  • FIG. 24 shows a schematic block diagram of another communication device provided by an embodiment of the present application.
  • FIG. 1 is a schematic diagram of a network architecture 100 applying the method of the embodiment of the present application. Each part involved in the network architecture 100 will be described below.
  • Terminal device 110 may include various handheld devices with wireless communication functions, vehicle-mounted devices, wearable devices, computing devices, Internet of Things terminal devices or other processing devices connected to a wireless modem, as well as various forms of terminals, mobile Mobile station (MS), terminal, user equipment (UE), soft terminal, etc. For example, water meters, electricity meters, sensors, etc.
  • MS mobile Mobile station
  • UE user equipment
  • (Wireless) access network radio access network, (R) AN) network element 120: used to provide network access for authorized terminal equipment in a specific area, and can use different qualities according to the level of terminal equipment and business needs Transmission tunnel.
  • (R) AN network element can manage wireless resources, provide access services for terminal equipment, and then complete the transfer of control signals and terminal equipment data between terminal equipment and core network
  • (R) AN network element can also be understood as a traditional network
  • User plane network element 130 used for packet routing and forwarding and quality of service (QoS) processing of user plane data, etc. It is mainly responsible for processing user packets, such as forwarding and billing.
  • QoS quality of service
  • the user plane network element may be a user plane function (UPF) network element.
  • the user plane network element may still be a UPF network element, or may have another name, which is not limited in this application.
  • Data network 140 An operator network used to provide users with data transmission services, such as IP multimedia services (IP multi-media service (IMS), Internet (Internet), etc.
  • IP multimedia services IP multi-media service (IMS), Internet (Internet), etc.
  • IMS IP multi-media service
  • Internet Internet
  • the data network may be a data network (DN).
  • DN data network
  • the data network may still be DN, or may have other names, which is not limited in this application.
  • Access management network element 150 mainly used for mobility management and access management, etc., and can be used to implement other functions of the mobility management entity (mobility management entity, MME) besides session management, for example, legal Monitoring and access authorization / authentication, user location update, user registration network, user switching and other functions.
  • mobility management entity mobility management entity, MME
  • session management for example, legal Monitoring and access authorization / authentication, user location update, user registration network, user switching and other functions.
  • the access management network element may be an access and mobility management function (access and mobility management function, AMF) network element.
  • AMF access and mobility management function
  • the access management network element may still be an AMF network element, or may have another name, which is not limited in this application.
  • Session management network element 160 mainly used for session management, such as session establishment, modification, and release. Specific functions include terminal equipment network protocol (IP) address allocation and management, selection of endpoints that can manage user plane functions, policy control and charging function interfaces, and downstream data notification.
  • IP terminal equipment network protocol
  • the session management network element may be a session management function (session management function, SMF) network element.
  • SMF session management function
  • the session management network element may still be an SMF network element, or it may have another name, which is not limited in this application.
  • Master clock device 170 provides a synchronized master clock signal, so that the terminal device in the mobile communication system synchronizes with the master clock signal.
  • the master clock device 170 may be a TSN master clock device, and may specifically be a programmable logic controller (programmable logic controller, PLC), which is not limited in the embodiment of the present application.
  • PLC programmable logic controller
  • system architecture 100 shown in FIG. 1 may further include the following network elements:
  • Policy control network elements a unified policy framework for guiding network behavior, providing policy rule information for control plane functional network elements (such as AMF, SMF network elements, etc.).
  • the policy control network element may be a policy and charging rule function (PCRF) network element.
  • the policy control network element may be a policy control function (PCF) network element.
  • PCF policy control function
  • the policy control network element may still be a PCF network element, or may have another name, which is not limited in this application.
  • Data management network element used to handle terminal equipment identification, access authentication, registration, etc.
  • the data management network element may be a unified data management (unified data management, UDM) network element.
  • UDM unified data management
  • the unified data management may still be a UDM network element, or it may have another name, which is not limited in this application.
  • the foregoing network element or function may be a network element in a hardware device, or a software function running on dedicated hardware, or a virtualized function instantiated on a platform (for example, a cloud platform).
  • the RAN network element is referred to as RAN
  • the UPF network element is referred to as UPF
  • the AMF network element is referred to as AMF
  • the SMF network element is referred to as SMF.
  • RAN described later in this application can be replaced by (R) AN) network elements
  • UPF can be replaced by user plane network elements
  • AMF can be replaced by access management network elements
  • SMF can be replaced by session management networks. yuan.
  • this application takes the device as the terminal device, RAN, UPF, AMF, SMF, TSN master clock device as an example to describe the synchronization method.
  • the device is a chip in the terminal device, a chip in the RAN, UPF
  • the implementation method of the chip in the chip, the chip in the AMF, the chip in the SMF, and the chip in the TSN master clock device can refer to the specific descriptions of the terminal device, RAN, UPF, AMF, SMF, and TSN, and will not be repeated .
  • the TSN clock synchronization mechanism may be used to synchronize the terminal devices.
  • FIG. 2 shows a principle diagram of a time synchronization method in 802.1AS.
  • Figure 2 contains four time-aware systems (time-aware) systems, which are the master clock (GrandMaster, GM), (i-1), i, (i + 1). Among them, each time-aware system contains a master port (master port) and a slave port (slave port).
  • each intermediate time-aware system needs to correct the correction field (correction filed, CF), where CF is the time deviation between the current node and the main clock, and intermediate time-aware system is The node between the GM and the time-aware system to be synchronized.
  • CF correction field
  • Time-aware systems can use two-step (two-step) mechanism to transmit 802.1AS messages, or one-step (one-step) mechanism to transmit 802.1AS messages.
  • two-step mechanism parameters are transferred using synchronization (SYNC, Synchronization) messages and follow-up messages.
  • SYNC Synchronization
  • the SYNC message is used for parameter transmission.
  • the following will describe how the intermediate node corrects the CF.
  • the time synchronization between the time-aware system (i + 1) and the GM will be described.
  • GM sends SYNC message # 1 at time T0.
  • the SYNC message # 1 carries T0, CF1, and frequency ratio ratio_GM.
  • the value of ratio_GM is 1, which can be understood as the frequency ratio of GM to GM.
  • the incoming port of (i-1), that is, the slave port receives SYNC message # 1.
  • the out port of (i-1), that is, the master port sends a SYNC message # 2.
  • the SYNC message # 2 carries T0, CF2, and the frequency ratio ratio_ (i-1) of GM and (i-1).
  • CF2 represents the time deviation between (i-1) and GM, as follows:
  • CF2 CF1 + transmission time # 1 + dwell time # 1 ⁇ ratio_ (i-1), the time unit is the time unit of GM.
  • the transmission time # 1 represents the transmission delay from the GM output port sending SYNC message # 1 to the (i-1) input port receiving the SYNC message # 1
  • the time unit of the transmission time # 1 is the time unit of GM.
  • the dwell time # 1 represents the processing delay from receiving the SYNC message # 1 at the ingress port (i-1) to sending the SYNC message # 2 at the egress port.
  • the time unit is the time unit of (i-1).
  • the dwell time # 1 ⁇ ratio_ (i-1) indicates that the time unit of the dwell time # 1 is converted into the time unit of GM.
  • the incoming port of (i), that is, the slave port receives SYNC message # 2.
  • the output port of (i), that is, the master port sends a SYNC message # 3.
  • the SYNC # 3 message carries T0, CF3, and the frequency ratio ratio_ (i) of GM and (i).
  • CF3 represents (i) the time deviation from GM, as follows:
  • CF3 (transmission time # 2 + residence time # 2 ⁇ ratio_NR) ⁇ ratio_ (i-1) + CF2, the time unit is the time unit of GM.
  • ratio_ (i) ratio_ (i-1) * ratio_NR
  • ratio_NR refers to the frequency ratio of (i-1) and (i)
  • ratio_ (i) means the frequency ratio of GM and (i).
  • the transmission time # 2 represents the transmission delay from the (i-1) outgoing port to send the SYNC message # 2 to (i) the incoming port to receive the SYNC message # 2
  • the time unit of the transmission time # 2 is (i-1 ) Time unit.
  • the dwell time # 2 represents the processing delay from receiving the SYNC message # 2 at the incoming port of (i) to sending the SYNC message # 3 at the outgoing port.
  • the time unit is the time unit of (i).
  • the dwell time # 2 ⁇ ratio_NR means that the time unit of the dwell time # 2 is converted into a time unit of (i-1).
  • (Transmission time # 2 + residence time # 2 ⁇ ratio_NR) ⁇ ratio_ (i-1) means that the time unit of (transmission time # 2 + residence time # 2 ⁇ ratio_NR) is converted to the time unit of GM.
  • the input port of (i + 1) that is, the slave port, receives SYNC message # 3 and synchronizes according to SYNC message # 3.
  • (i + 1) is the node to be synchronized.
  • the ingress of (i + 1) calculates the time deviation between it and GM and records it as CF4, as follows:
  • CF4 Transmission time # 3 ⁇ ratio_ (i) + CF3, the time unit is the time unit of GM.
  • the transmission time # 3 identifies the transmission delay from the (i) egress port to the (i + 1) in port, and the unit is the time unit of (i).
  • the time after the input port of (i + 1) is synchronized with GM is T0 + CF4.
  • the network element (or the network element and the network element in the mobile network) in the mobile network can be The links between the elements are regarded as a whole, which can be called a relay network.
  • the relay network can receive a clock synchronization message (such as a SYNC message) from the TSN master clock device, and send the clock synchronization message to the endpoint device.
  • the clock synchronization message sent by the relay network to the endpoint device includes the correction field CF, so that the endpoint device can synchronize with the TSN master clock device according to the correction field CF.
  • endpoint devices are devices that need to be synchronized, such as factory devices (such as sensors).
  • FIG. 3 shows a schematic diagram of a scenario to which an embodiment of the present application is applied.
  • the relay network 31 may include a terminal device 302, a RAN 303, and a UPF 304.
  • the terminal equipment 302, RAN 303, and UPF 304 in the mobile network can be taken as a whole, that is, the relay network 31, which can also be referred to as "time-aware relay (time-aware relay 31)," That is, the terminal device 302, the RAN 303, and the UPF 304 as a bridge or router.
  • time-aware relay time-aware relay 31
  • the terminal device 302 can be synchronized with the master clock device 305, or the endpoint device 301 connected with the terminal device 302 can be synchronized with the TSN master clock device 305.
  • FIG. 4 shows a schematic diagram of another scenario to which the embodiment of the present application is applied.
  • the relay network 41 includes terminal equipment 402 and RAN 403.
  • the terminal device 402 and the RAN 403 in the mobile network can be taken as a whole, that is, the relay network 41, which can also be called “time-aware relay (time-aware relay 41)", that is, the terminal device 402 Integrate with RAN403 as a bridge or router.
  • the relay network 41 which can also be called “time-aware relay (time-aware relay 41)"
  • the terminal device 402 Integrate with RAN403 as a bridge or router the terminal device 402 Integrate with RAN403 as a bridge or router.
  • the synchronization of the terminal device 402 and the master clock device 405, or the synchronization of the endpoint device 401 connected to the terminal device 402 and the TSN master clock device 405 can be achieved.
  • the master clock device 305 shown in FIG. 3 and the master clock device 405 shown in FIG. 4 may also be device nodes that are clock synchronized with the master clock device.
  • the present invention is described by taking the master clock device as an example, but this is not limited.
  • the endpoint device may be co-located with the terminal device in the relay network, which is not limited in this embodiment of the present application.
  • FIG. 5 shows a schematic flowchart of a synchronization method provided by an embodiment of the present application. This method is performed by the first network element in the relay network.
  • the first network element may be UPF, RAN, or terminal equipment.
  • the relay network includes RAN and terminal equipment, the first network element may be RAN or terminal equipment.
  • the method of synchronization shown in FIG. 5 includes steps 510 to 530.
  • the first network element receives a clock synchronization message.
  • the first network element determines a first time of the relay network.
  • the first time of the relay network includes the first time corresponding to the transmission of the clock synchronization message between the RAN and the terminal device. Downlink transmission delay.
  • the first network element determines a time correction field of the relay network, where the time correction field includes the first downlink transmission delay.
  • the first network element may determine the time correction field of the relay network according to the clock synchronization message, where the time correction field includes the first corresponding to the transmission of the clock synchronization message between the RAN device and the terminal device.
  • the downlink transmission delay helps to realize the clock synchronization of the terminal device or the endpoint device with the external clock by using the TSN clock synchronization mechanism in the mobile network.
  • the first time may also be referred to as the dwell time, which represents the processing delay from receiving the SYNC message at the ingress port of the relay network to sending the SYNC message at the egress port.
  • the first time since the relay network includes at least the RAN and the terminal device, the first time at least includes the first downlink transmission delay for transmitting the clock synchronization message between the RAN device and the terminal device.
  • the link between the terminal device 302 and the endpoint device 301, and the link between the UPF 304 and the TSN master clock device 305 are TSN links.
  • the 802.1AS time synchronization principle can be used for parameter transmission. This embodiment of the present application does not describe this part of the link in detail.
  • the input port of time-aware relay 31 is the input port of UPF 304; the output port of time-aware relay 31 is the output port of terminal device 302.
  • the correction field CF includes the residence time corresponding to the time-aware relay 31 processing the SYNC message, and the transmission delay between the time-aware relay 31 and the node sending the SYNC message.
  • CF dwell time + N6 delay (delay_N6_link).
  • the N6 delay is the downlink transmission delay between the node device that sends the clock synchronization message (that is, the TSN master clock device 305) and the relay network 31 (that is, the input port of the UPF 304). This embodiment of the present application can be called This is the second downlink transmission delay.
  • the residence time includes the air interface delay (delay_Uu_DL) and N3 delay (delay_N3_link) between the RAN and the terminal device.
  • delay_Uu_DL may specifically be the first downlink transmission delay corresponding to the transmission of the SYNC message between the RAN and the terminal device
  • delay_N3_link may specifically be the downlink transmission delay between the UPF and the RAN, which may be referred to in the embodiments of this application It is the third downlink transmission delay.
  • the UPF 304, the RAN 303, or the terminal device 302 in the relay network 31 may perform time domain correction, that is, determine the correction domain CF.
  • the outgoing port of the relay network 31, that is, the outgoing port of the terminal device 302, the link Link to be corrected is as follows:
  • relay_link represents the link corresponding to the relay network 31, which includes the Uu link (Uu_link) between the outgoing port of the terminal device 302 and the incoming port of the RAN 303, and the incoming port of the UPF 304 and the incoming port of the RAN N3_link
  • N6_link represents the link between the outgoing port of the TSN master clock device 305 and the incoming port of the UPF 304.
  • the frequency ratio of UPF304 local time to RAN303 local time is ratio1
  • the frequency ratio of TSN master clock to UPF304 local time is ratio2.
  • FIG. 6 shows an example of a specific synchronization method provided by an embodiment of the present application. It should be understood that FIG. 6 shows steps or operations of the synchronization method, but these steps or operations are merely examples, and other operations or variations of the operations in FIG. 6 may be performed in the embodiments of the present application. In addition, each step in FIG. 6 may be performed in a different order than that presented in FIG. 6, and it is possible that not all operations in FIG. 6 are to be performed.
  • the same reference numerals in FIG. 6 as in FIG. 3 denote the same or similar meanings, and for the sake of brevity, they will not be repeated here.
  • the TSN clock sends a SYNC message to the ingress port of the relay network 31, that is, the ingress port of the UPF.
  • the TSN clock transmission time is t1.
  • the TSN clock may determine the N6 delay (delay_N6_link), and send the delay_N6_link to the relay network 31.
  • the SYNC message carries t1, ratio2, and delay_N6_link.
  • t1, ratio2, and delay_N6_link are carried in a follow_up message immediately following the SYNC message.
  • the relay network 31 may measure delay_N6_link.
  • the UPF measurement delay_N6_link may refer to the description in the prior art, and will not be described in detail here.
  • the TSN clock may be replaced with other clock devices, such as GrandMaster, which is not specifically limited in the embodiment of the present application.
  • the ingress port of the relay network 31 that is, the ingress port of the UPF receives the SYNC message sent by the TSN clock, and triggers the UPF to determine the residence time of the relay network.
  • the SYNC message may be used to trigger the UPF to determine the residence time of the relay network. Specifically, after the UPF recognizes that the received message is a SYNC message, it may trigger the UPF to determine the residence time of the relay network. Specifically, the UPF may identify whether the received message is a SYNC message according to the policy information configured on the UPF, or according to the policy information received from the SMF.
  • the strategy information refers to strategies for identifying SYNC messages, such as source address and destination address.
  • the UPF determines that the source or destination address of the received message is consistent with the policy information, it can determine that the message is a SYNC message.
  • the policy information may also be referred to as other names, such as forwarding rules, or session management information, etc., which are not limited in the embodiments of the present application.
  • the policy information may be the destination MAC address 01-80-C2-00-00-0E.
  • the UPF determines that the MAC address of the received message is 01-80-C2-00-00-0E
  • the RAN judges the message The text is a SYNC message.
  • the UPF may trigger downlink QoS monitoring between the UPF and the UE to determine the residence time of the relay network.
  • QoS monitoring may specifically include steps 603 to 609.
  • the UPF sends N3 DL to the RAN.
  • the UPF sends a SYNC message to the RAN through the N3 user plane path.
  • the SYNC message is the SYNC message received from the TSN clock in 602.
  • the UPF needs to encapsulate the GTP-U header (header) for the SYNC message, and the message after encapsulating the GTP-U header is the N3 DL PDU.
  • the UPF may also send first indication information to the RAN, where the first indication information is used to instruct the RAN device to acquire the downlink air interface delay, that is, the first downlink transmission delay.
  • the first indication information is used to instruct the RAN to trigger downlink air interface delay measurement.
  • the first indication information may be sent to the RAN together with the SYNC message, for example, the first indication information is carried in the GTP-U header, which is not limited in this embodiment of the present application.
  • the first indication information includes a first quality of service (QoS) flow identifier (QoS flow ID, QFI).
  • QoS flow ID QoS flow ID
  • the first indication information is used to instruct the RAN device to acquire the first downlink transmission delay when receiving the message corresponding to the first QFI.
  • the first QFI is a special QFI, that is, the QoS flow message corresponding to the first QFI is a clock synchronization message, such as a SYNC message. That is, when the message received by the RAN includes the first QFI, the RAN can recognize the message as a SYNC message, and then can trigger the measurement of the first downlink transmission delay.
  • the RAN receives N3 DL from the UPF PDU. After receiving the N3 DL sent by the UPF, the RAN triggers the downlink air interface delay measurement according to the first indication information. At this time, the RAN records the air interface time air_t1 corresponding to receiving the SYNC message.
  • the RAN sends a DL PDU to the terminal device through the air interface, and the DL PDU includes a SYNC message.
  • the terminal After receiving the SYNC message, the terminal returns an acknowledgement (acknowledge, ACK) to the RAN.
  • acknowledgement acknowledgement
  • the ACK carries the air interface time air_t2 corresponding to the terminal device receiving the SYNC message.
  • the network element receiving the SYNC message includes the network element processing the SYNC message, for example, processing the SYNC message through each protocol layer on the network element.
  • the air interface time corresponding to the SYNC message received by the network element is the time after the network element processes the SYNC message.
  • the network element is, for example, terminal equipment, RAN, UPF, or the like. Therefore, the outgoing port of the terminal device 302 described in this application can also be understood as the incoming port of the terminal device 302; the incoming port of the terminal device 302 receives the air interface time corresponding to the SYNC message, which can be understood as the The time after processing.
  • the RAN When the RAN receives the ACK returned by the terminal device, it determines that the downlink transmission is successful. At this time, the RAN determines the downlink air interface delay delay_Uu_DL, where,
  • delay_Uu_DL air_t2-air_t1
  • the time unit is the air interface time unit.
  • the RAN sends an N3 message to the UPF.
  • the N3 packet includes the downlink air interface delay delay_Uu_DL.
  • the UPF receives the N3 message and obtains the delay_Uu_DL of the downlink air interface.
  • UPF obtains the N3 delay.
  • the UPF can measure the N3 delay (delay_N3_link) through the GTP-U echo request (echo request) and the GTP-U echo response (echo Response).
  • the UPF sends a GTP-U echo request to the RAN at time Ta; the RAN receives the GTP-U echo request at time Tb.
  • the RAN sends a GTP-U echo response to the UPF at time Tc; the UPF receives the GTP-U echo response at time Td.
  • delay_N3_link [(Td-Ta)-(Tc-Tb)] / 2.
  • delay_N3_link [(Td-Ta)-(Tc-Tb) * ratio1] / 2.
  • the time unit of delay_N3_link is the UPF local time unit.
  • the UPF determines the residence time (delay_relay) of the relay network, which may also be called the downlink transmission delay of the relay network.
  • delay_relay is as follows:
  • delay_relay delay_Uu_DL + delay_N3_link;
  • delay_relay delay_Uu_DL ⁇ ratio1 + delay_N3_link.
  • the delay_relay is converted to the TSN time unit as:
  • delay_relay (delay_Uu_DL ⁇ ratio1 + delay_N3_link) ⁇ ratio2.
  • the UPF determines the time correction field CF.
  • the UPF determines the time correction field CF according to the residence time of the relay network (delay_relay) and the transmission delay between the UPF and the TSN clock, that is, N6 delay (delay_N6_link), and the time unit TSN time unit.
  • CF is as follows:
  • the UPF sends the time correction field CF to the RAN.
  • the RAN sends the time correction field CF to the terminal device.
  • the UPF may carry the time correction field in the follow_up message and send it to the RAN. It can be understood that the follow_up message is the follow_up message immediately following the SYNC message in 603. Then in step 612, the RAN forwards the follow_up message to the terminal device through the air interface.
  • the UPF may also send the CF to the RAN through other messages, which is not limited in this embodiment of the present application.
  • the terminal device can perform clock synchronization according to the received CF and TSN clocks. Further, the terminal device can perform clock synchronization with the endpoint device. Specifically, the synchronization process between the terminal device and the endpoint device can refer to the 802.1AS mechanism, which is not described in detail here.
  • the terminal device, RAN, and UPF are used as a relay network, and the UPF in the relay network determines the "internal delay" of the relay network transmitting the SYNC message, that is, it is received from the UPF.
  • the SYNC message when the terminal device receives the SYNC message, realizes the time synchronization between the terminal device (or the TSN endpoint device connected to the terminal device) and the TSN clock source.
  • FIG. 7 shows an example of a specific synchronization method provided by an embodiment of the present application. It should be understood that FIG. 7 shows steps or operations of the synchronization method, but these steps or operations are only examples, and other operations or variations of the operations in FIG. 7 may be performed in the embodiments of the present application. In addition, each step in FIG. 7 may be performed in a different order from that presented in FIG. 7, and it may not be necessary to perform all operations in FIG. 7.
  • the same reference numerals in FIG. 7 as in FIG. 3 denote the same or similar meanings, and for the sake of brevity, they will not be repeated here.
  • the TSN clock sends a SYNC message to the incoming port of the relay network 31, that is, the incoming port of the UPF.
  • 701 can refer to the description in 601. To avoid repetition, no further description is provided here.
  • the UPF ingress port receives the SYNC message sent by the TSN clock, and the UPF egress port sends the SYNC message to the RAN ingress port.
  • the delay_N6_link is sent to the RAN.
  • the RAN incoming port receives the SYNC message, triggering the RAN to determine the residence time of the relay network.
  • the SYNC message may be used to trigger the RAN to determine the residence time of the relay network. Specifically, after the RAN recognizes that the received message is a SYNC message, it may trigger the RAN to determine the residence time of the relay network.
  • the RAN may identify whether the received message is a SYNC message according to the policy information configured on the RAN, or according to the policy information received from the SMF. After identifying that the message is a SYNC message, the first downlink transmission delay and the third downlink transmission delay can be obtained.
  • the policy information please refer to the description above, and for the sake of brevity, it will not be repeated here.
  • the policy information may be the destination MAC address 01-80-C2-00-00-0E.
  • the RAN determines that the MAC address of the received message is 01-80-C2-00-00-0E, the RAN determines the The text is a SYNC message.
  • the RAN may receive second indication information, and the second indication information is used to instruct the RAN to acquire the residence time of the relay network, and then the RAN acquires the first downlink transmission delay and The third downlink transmission delay.
  • the second indication information may be sent to the RAN together with the SYNC message, for example, the second indication information is carried in the GTP-U header, which is not limited in this embodiment of the present application.
  • the second indication information includes a second quality of service (QoS) flow identifier (QoS flow ID, QFI).
  • QoS flow ID QoS flow ID
  • the second indication information is used to instruct the RAN device to acquire the residence time of the relay network when receiving the message corresponding to the second QFI.
  • the QoS flow message corresponding to the second QFI is a clock synchronization message, that is, a SYNC message. That is to say, when the message received by the RAN includes the second QFI, the RAN can recognize the message as a SYNC message, and then can trigger the acquisition of the residence time of the relay network.
  • the RAN may trigger the determination of the downlink transmission delay between the UPF and the terminal device. Specifically, steps 704 to 708 may be included.
  • the RAN records the air interface time air_t1 corresponding to receiving the SYNC message.
  • the RAN sends the DL PDU to the terminal device.
  • the RAN sends a DL PDU to the terminal device through the air interface, and the DL PDU includes a SYNC message.
  • the terminal After receiving the SYNC message, the terminal returns an acknowledgement (acknowledge, ACK) to the RAN.
  • acknowledgement acknowledgement
  • the ACK carries the air interface time air_t2 corresponding to the terminal device receiving the SYNC message.
  • the RAN When the RAN receives the ACK returned by the terminal device, it determines that the downlink transmission is successful. At this time, the RAN determines the downlink air interface delay delay_Uu_DL, where,
  • delay_Uu_DL air_t2-air_t1
  • the time unit of delay_Uu_DL is the air interface time unit.
  • the RAN obtains the N3 delay.
  • the RAN may measure the N3 delay (delay_N3_link) through the GTP-U echo request (echo request) and the GTP-U echo response (echo Response).
  • the RAN sends a GTP-U echo request to the RAN at time Ta; the UPF receives the GTP-U echo request at time Tb. UPF sends a GTP-U echo response to UPF at time Tc; RAN receives the GTP-U echo response at time Td. Then, there are:
  • delay_N3_link [(Td-Ta)-(Tc-Tb)] / 2.
  • delay_N3_link [(Td-Ta)-(Tc-Tb) * ratio1] / 2.
  • the time unit of delay_N3_link is the UPF local time unit.
  • the RAN determines the residence time of the relay network (delay_relay). Specifically, delay_relay is as follows:
  • delay_relay delay_Uu_DL ⁇ ratio1 + delay_N3_link, corresponding to the UPF local time unit.
  • the RAN determines the time correction field CF.
  • CF is as follows:
  • CF delay_relay * ratio2 + delay_N6_link.
  • the frequency ratio of the TSN clock and the UPF local clock is ratio2.
  • the time unit of CF is TSN time unit.
  • the way in which the RAN determines the time correction field is similar to the way in which the UPF determines the time correction field, and reference may be made to the description in 610, which will not be repeated here.
  • the RAN sends the time correction field CF to the terminal device.
  • the RAN may carry the time correction field in the follow_up message and send it to the UE through the air interface.
  • the follow_up message is the follow_up message immediately following the SYNC message in 704.
  • the RAN may also send the CF to the UE through other messages, which is not limited in this embodiment of the present application.
  • the terminal device can perform clock synchronization according to the received CF and TSN clocks. Further, the terminal device can perform clock synchronization with the endpoint device. Specifically, the synchronization process between the terminal device and the endpoint device can refer to the 802.1AS mechanism, which is not described in detail here.
  • the terminal device, RAN, and UPF are used as a relay network, and the RAN in the relay network determines the "internal delay" of the relay network transmitting the SYNC message, that is, it is received from the UPF.
  • the SYNC message when the terminal device receives the SYNC message, realizes the time synchronization between the terminal device (or the TSN endpoint device connected to the terminal device) and the TSN clock source.
  • FIG. 8 shows an example of a specific synchronization method provided by an embodiment of the present application. It should be understood that FIG. 8 shows steps or operations of the synchronization method, but these steps or operations are merely examples, and other operations or variations of the operations in FIG. 8 may be performed in the embodiments of the present application. In addition, each step in FIG. 8 may be performed in a different order from that presented in FIG. 8, and it may not be necessary to perform all operations in FIG. 8.
  • the same reference numerals in FIG. 8 as in FIG. 3 denote the same or similar meanings, and for the sake of brevity, they will not be repeated here.
  • the TSN clock sends a SYNC message to the incoming port of the relay network 31, that is, the incoming port of the UPF.
  • 801 can refer to the description in 601. To avoid repetition, details are not described here.
  • the input port of the UPF receives the SYNC message sent by the TSN clock, and the output port of the UPF sends the SYNC message to the RAN input port.
  • the delay_N6_link is sent to the RAN.
  • the RAN ingress port receives the SYNC message sent by the TSN clock, and the RAN egress port sends the SYNC message to the terminal device ingress port.
  • the RAN records the air interface time air_t1 corresponding to receiving the SYNC message, and sends the air interface time air_t1 to the terminal device.
  • the RAN can also send ratio1 to the terminal device.
  • the terminal device receives the SYNC message, and triggers the terminal device to determine the residence time of the relay network. At this time, the terminal device records the air interface time air_t2 corresponding to receiving the SYNC message.
  • the SYNC message may be used to trigger the terminal device to determine the residence time of the relay network. Specifically, after the terminal device recognizes that the received message is a SYNC message, the terminal device may be triggered to determine the residence time of the relay network. Specifically, the terminal device may identify whether the received message is a SYNC message according to the policy information configured on the terminal device or according to the policy information received from the SMF. Specifically, for the policy information, please refer to the description above, and for the sake of brevity, it will not be repeated here.
  • the policy information may be the destination MAC address 01-80-C2-00-00-0E.
  • the terminal device determines that the destination MAC address of the received message is 01-80-C2-00-00-0E, the RAN judges This message is a SYNC message.
  • the terminal device may receive third indication information, and the third indication information is used to instruct the terminal device to acquire the residence time of the relay network.
  • the third indication information includes a third quality of service (QoS) flow identifier (QoS flow ID, QFI).
  • QoS quality of service
  • the third indication information is used to instruct the terminal device to obtain the residence time of the relay network when receiving the message corresponding to the third QFI.
  • the terminal device stores the correspondence between the wireless bearer and QFI.
  • the terminal device determines that the received message corresponds to the third QFI according to the correspondence between the wireless bearer and the QFI, it can recognize that the message is a SYNC message, and then trigger the acquisition of the residence time of the relay network.
  • the QFI corresponding to the message can be determined according to the correspondence between the wireless bearer and the QFI.
  • the terminal device can recognize the message as a SYNC message.
  • the terminal device determines the air interface delay delay_Uu_DL as follows:
  • the air delay unit delay_Uu_DL is the air interface time unit.
  • the terminal device converts delay_Uu_DL to UPF local time as:
  • delay_Uu_DL (air_t2-air_t1) ⁇ ratio1.
  • the UPF or RAN determines the N3 link delay (delay_N3_link) through the GTP-U echo request and GTP-U echo response mechanisms. It should be noted that the embodiment of the present application does not limit the measurement timing for determining the N3 link delay, that is, 806 may occur before 805, or after 805, or occur simultaneously with 805, which are all implemented in this application. Cases within the scope of protection.
  • the RAN receives the GTP-U echo request at time N3_t2, and sends the GTP-U echo response at time N3_t3.
  • the GTP-U echo response carries N3_t2, N3_t3, or (N3_t3-N3_t2), that is, the difference between N3_t3 and N3_t2.
  • UPF receives the GTP-U echo response at N3_t4.
  • UPF calculates delay_N3_link.
  • N3_t1, N3_t4 correspond to UPF local time
  • N3_t2 correspond to RAN local time.
  • Delay_N3_Link [(N3_t4-N3_t1)-(N3_t3-N3_t2) ⁇ ratio1] / 2
  • the RAN sends the N3 delay to the terminal device.
  • the RAN determines the N3 time delay
  • the RAN sends the N3 time delay to the terminal device.
  • the RAN can send the N3 time delay to the terminal device through the follow_up message or the above-mentioned SYNC message.
  • step 807 may be combined with step 803.
  • the UPF sends the N3 delay to the terminal equipment via the RAN.
  • the N3 time delay is sent by the UPF to the terminal device.
  • the UPF can send the N3 time delay to the terminal device through the follow_up message or the above-mentioned SYNC message.
  • step 807 ' may be combined with step 802.
  • the terminal device determines the residence time of the relay network (delay_relay). Specifically, delay_relay is as follows:
  • delay_relay delay_Uu_DL ⁇ ratio1 + delay_N3_link, the unit of time is UPF local time.
  • the terminal device determines the correction field CF.
  • CF is as follows:
  • CF delay_relay * ratio2 + delay_N6_link.
  • the time unit of CF is TSN time unit.
  • the terminal device can perform clock synchronization according to the CF and TSN clocks. Further, the terminal device can perform clock synchronization with the endpoint device. Specifically, the synchronization process between the terminal device and the endpoint device can refer to the 802.1AS mechanism, which is not described in detail here.
  • the terminal device, RAN, and UPF are used as a relay network, and the terminal device in the relay network determines the "internal delay" of the relay network transmitting the SYNC message, that is, from the UPF Receive the SYNC message and the time when the terminal device receives the SYNC message to realize the time synchronization between the terminal device (or the TSN endpoint device connected to the terminal device) and the TSN clock source.
  • the embodiments involved in this application involve the determination of the segment delay and the conversion of time units.
  • the determination of the segment delay and the conversion to the time unit are all performed at the same execution point.
  • the UPF acquires the segment delay and performs unit conversion;
  • the RAN acquires each segment delay and performs unit conversion;
  • the UE acquires each segment delay and performs unit conversion.
  • segment delay and time unit conversion are performed by different execution points.
  • the RAN converts the air interface time to the UPF local time and sends it to the UPF and UPF to obtain the converted air interface delay.
  • the link between the terminal device 402 and the endpoint device 401 and the link between the RAN 403 and the TSN master clock device 405 are TSN links.
  • the 802.1AS time synchronization principle can be used for parameter transmission. This embodiment of the present application does not describe this part of the link in detail.
  • the in-port of time-aware relay 41 is the in-port of RAN 403; the out-port of time-aware relay 41 is the out-port of terminal device 402.
  • the time correction field CF needs to be adjusted.
  • CF residence time + N6 * delay (delay_N6 * _link).
  • the N6 * delay is the downlink transmission delay between the node device that sends the clock synchronization message (that is, the TSN master clock device 305) and the relay network (that is, the ingress port of the RAN 403).
  • This embodiment of the present application can be called This is the second downlink transmission delay.
  • the dwell time is the air interface delay (delay_Uu_DL) between the RAN device and the terminal device.
  • delay_Uu_DL may specifically be the first downlink transmission delay for transmitting the SYNC message between the RAN device and the terminal device.
  • the RAN 403 or the terminal device 402 in the relay network 41 may perform time domain correction.
  • the outgoing port of the relay network 41 that is, the outgoing port of the terminal device 402
  • the link Link to be corrected is as follows:
  • relay_link represents the link in the relay network 41, that is, includes the Uu link (Uu_link) between the egress port of the terminal device 402 and the ingress port of the RAN 403, and N6 * _link represents the egress port of the TSN master clock device 405 and The link between the incoming ports of RAN403.
  • the frequency ratio of the TSN master clock to the RAN 403 local time is ratio.
  • FIG. 9 shows an example of a specific synchronization method provided by an embodiment of the present application. It should be understood that FIG. 9 shows steps or operations of the synchronization method, but these steps or operations are only examples, and other operations or variations of the operations in FIG. 9 may be performed in the embodiments of the present application. In addition, each step in FIG. 9 may be performed in a different order from that presented in FIG. 9, and it may not be necessary to perform all operations in FIG. 9.
  • the same reference numerals in FIG. 9 as in FIG. 4 denote the same or similar meanings, and for the sake of brevity, they will not be repeated here.
  • the TSN clock sends a SYNC message to the ingress port of the relay network 41, that is, the RAN ingress port.
  • the TSN clock transmission time is t1.
  • the TSN clock may determine the N6 delay (delay_N6 * _link), and send the delay_N6 * _link to the relay network 41.
  • the SYNC message carries t1, ratio, and delay_N6 * _link.
  • t1, ratio, and delay_N6 * _link are carried in the follow_up message immediately following the SYNC message.
  • the delay_N6 * _link may be measured by the relay network 41 (such as the RAN in the relay network 41).
  • the RAN measurement delay_N6 * _link can refer to the description in the prior art, and will not be described in detail here.
  • the RAN incoming port receives the SYNC message sent by the TSN clock, triggering the RAN to determine the residence time of the relay network. At this time, the RAN records the air interface time air_t1 corresponding to receiving the SYNC message.
  • the SYNC message may be used to trigger the RAN to determine the residence time of the relay network. Specifically, after the RAN recognizes that the received message is a SYNC message, it may trigger the RAN to determine the residence time of the relay network.
  • the RAN may identify whether the received message is a SYNC message according to the policy information configured on the RAN, or according to the policy information received from the SMF. After identifying that the message is a SYNC message, the first downlink transmission delay and the third downlink transmission delay can be obtained.
  • the policy information please refer to the description above, and for the sake of brevity, it will not be repeated here.
  • the policy information may be the destination MAC address 01-80-C2-00-00-0E.
  • the RAN determines that the destination MAC address of the received message is 01-80-C2-00-00-0E, the RAN determines the The message is a SYNC message.
  • the RAN can also measure delay_N6 * _link.
  • the RAN sends a SYNC message to the terminal device.
  • the RAN sends a SYNC message to the terminal device through the air interface, and the outer layer of the SYNC message encapsulates the SDAP header and PDCP header.
  • the terminal After receiving the SYNC message, the terminal returns an acknowledgement (acknowledge, ACK) to the RAN. Among them, the ACK carries the air interface time air_t2 corresponding to the terminal device receiving the SYNC message.
  • the RAN receives the ACK returned by the terminal device, it determines that the downlink transmission is successful. At this time, the RAN determines the downlink air interface delay delay_Uu_DL, where,
  • delay_Uu_DL air_t2-air_t1
  • delay_Uu_DL time unit is air interface time unit.
  • RAN converts delay_Uu_DL to TSN time unit, then:
  • delay_Uu_DL (air_t2-air_t1) ⁇ ratio.
  • delay_relay the residence time of the relay network
  • delay_relay delay_Uu_DL, that is, the residence time of the relay network delay_relay is equal to the delay of the downlink air interface delay_Uu_DL.
  • the RAN determines the time correction field CF.
  • CF is as follows:
  • the RAN sends the time correction field CF to the terminal device.
  • the RAN may carry the time correction field in the follow_up message and send it to the terminal device through the air interface. It can be understood that the follow_up message is the follow_up message immediately following the SYNC message in 903.
  • the terminal device can perform clock synchronization according to the received CF and TSN clocks. Further, the terminal device can perform clock synchronization with the endpoint device. Specifically, the synchronization process between the terminal device and the endpoint device can refer to the 802.1AS mechanism, which is not described in detail here. It should be noted that in step 908, the RAN may also send the CF to the terminal device through other messages, which is not limited in the present invention.
  • the terminal device and the RAN are used as a relay network, and the RAN in the relay network determines the "internal delay" of the relay network transmitting the SYNC message, that is, receiving the SYNC message from the RAN Time to the time when the terminal device receives the SYNC message to achieve time synchronization between the terminal device (or the TSN endpoint device connected to the terminal device) and the TSN clock source.
  • the terminal equipment performs time domain correction
  • FIG. 10 shows an example of a specific synchronization method provided by an embodiment of the present application. It should be understood that FIG. 10 shows steps or operations of the synchronization method, but these steps or operations are only examples, and other operations or variations of the operations in FIG. 10 may be performed in the embodiments of the present application. In addition, each step in FIG. 10 may be performed in a different order from that presented in FIG. 10, and it is possible that not all operations in FIG. 10 are to be performed.
  • the same reference numerals in FIG. 10 as in FIG. 4 denote the same or similar meanings, and for the sake of brevity, they will not be repeated here.
  • the TSN clock sends a SYNC message to the ingress port of the relay network 41, that is, the RAN ingress port.
  • the RAN incoming port receives the SYNC message sent by the TSN clock, and the RAN outgoing port sends the SYNC message to the ingress port of the terminal device.
  • the RAN sends a SYNC message to the terminal device through the air interface, and the outer layer of the SYNC message encapsulates the SDAP header and PDCP header.
  • the RAN when the RAN measures delay_N6 * _link, it sends delay_N6 * _link to the terminal device.
  • the RAN records the air interface time air_t1 corresponding to receiving the SYNC message, and sends the air interface time air_t1 to the terminal device.
  • the RAN can also send a ratio to the terminal device.
  • the terminal device receives the SYNC message, triggering the terminal device to determine the residence time of the relay network. At this time, the terminal device records the air interface time air_t2 corresponding to receiving the SYNC message.
  • the SYNC message may be used to trigger the terminal device to determine the residence time of the relay network.
  • the terminal device recognizes the SYNC message.
  • the terminal device determines the air interface delay delay_Uu_DL, as follows:
  • the air delay unit delay_Uu_DL is the air interface time unit.
  • delay_Uu_DL (air_t2-air_t1) ⁇ ratio.
  • the terminal device determines the residence time of the relay network (delay_relay). Specifically, delay_relay is as follows:
  • delay_relay delay_Uu_DL, that is, the residence time of the relay network delay_relay is equal to the delay of the downlink air interface delay_Uu_DL.
  • the terminal device determines the correction field CF.
  • CF is as follows:
  • the terminal device can perform clock synchronization according to the CF and TSN clocks. Further, the terminal device can perform clock synchronization with the endpoint device. Specifically, the synchronization process between the terminal device and the endpoint device can refer to the 802.1AS mechanism, which is not described in detail here.
  • the terminal device and the RAN are used as a relay network, and the terminal device in the relay network determines the "internal delay" of the relay network transmitting the SYNC message, that is, receiving the SYNC from the RAN.
  • the message when the terminal device receives the SYNC message, realizes the time synchronization between the terminal device (or the TSN endpoint device connected to the terminal device) and the TSN clock source.
  • an end-to-end (E2E) clock synchronization mechanism may be used to achieve network-wide synchronization.
  • E2E clock synchronization includes time synchronization and frequency synchronization.
  • Time synchronization refers to regulating the internal time of the device according to the received time;
  • frequency synchronization refers to maintaining a certain strict specific relationship between the frequencies or phases of the signals, and the corresponding effective instants are at the same average rate It appears to maintain that all devices in the communication network operate at the same rate, that is, to maintain a constant phase difference between the signals.
  • the time of receiving and sending the message can be marked by time stamping the message, and the path delay measurement between the master and slave devices can be implemented through a delay measurement mechanism.
  • the slave clock (slave) uses the acquired timestamp and path delay parameters to calculate the master-slave time offset (offset), thereby controlling the slave clock synchronization to the master clock (master).
  • the messages involved may include SYNC messages, delay request (delay_req), and delay response (delay_resp).
  • the master clock selection and negotiation algorithm obtains the tree topology and grandmaster clock of the whole network clock synchronization, and then starts from the grandmaster clock and sends a 1588 synchronization message to the neighboring node (slave).
  • Each slave refers to the master for clocking
  • it will exchange 1588 protocol packets with neighbors, calculate the offset and frequency deviation between the master and slave clocks, complete the local clock synchronization, and so on.
  • FIG. 11 shows a schematic diagram of another time synchronization method in 802.1AS. Specifically, the interaction process between master and slave is as follows:
  • the master sends a SYNC message at time t1, and carries the t1 timestamp in the SYNC message.
  • the slave receives the SYNC message at time t2 and generates a t2 timestamp locally. And, the slave obtains the t1 timestamp from the received SYNC message.
  • the slave sends a delay request (delay_req) message at time t3, and generates a t3 timestamp locally.
  • Maser receives the delay_req message at time t4, and generates the t4 timestamp locally, and then carries the t4 timestamp in the delay_resp message and sends it back to the slave.
  • the slave receives the delay_resp message and extracts the t4 timestamp from the message.
  • the delay of the transmission path from the master to the slave may be expressed as delayms
  • the delay of the transmission path of the slave to the master may be expressed as delaysm
  • the time deviation between the slave and the master may be expressed as an offset.
  • t4-t3 delayms-offset, (2), delayms-offset, (2);
  • delaysm delayms, that is, the transmission and reception link delay between master and slave is symmetric
  • the slave can calculate the time offset offset between itself and the master according to the four time stamps t1, t2, t3, and t4, and adjust its own time to achieve synchronization with the master.
  • delaysm delayms.
  • two adjacent nodes are directly connected by wire, and the path delay differs by no more than subtle ( ⁇ s), so the accuracy of the 1588v2 protocol can reach the ⁇ s level at this time.
  • FIG. 12 shows a principle diagram of a frequency synchronization method in 802.1AS. Specifically, the master periodically sends SYNC messages to the slave. Specifically, the interaction process between master and slave is as follows:
  • the master sends a SYNC message at time t5.
  • the t5 time stamp may be carried in the follow_up message corresponding to the SYNC message. In another implementation manner, the t5 time stamp may be carried in the SYNC message.
  • the slave receives the SYNC message at time t6 and generates the t6 timestamp locally. And, the slave obtains the t5 timestamp from the received follow_up message or SYNC message.
  • the master sends a SYNC message at time t7.
  • the t7 timestamp may be carried in the follow_up message corresponding to the SYNC message. In another implementation, the t7 time stamp can be carried in the SYNC message.
  • the slave receives the SYNC message at time t8 and generates a t8 timestamp locally. And, the slave obtains the t7 timestamp from the received follow_up message or SYNC message.
  • the slave frequency is faster than the master frequency, and the slave frequency needs to be adjusted down;
  • the slave frequency is slower than the master frequency, and the slave frequency needs to be adjusted faster.
  • the frequency ratio neighborRateRatio of the master device and the slave device can be expressed as the following formula:
  • the clock synchronization schemes shown in FIGS. 11 and 12 depend on the symmetry of the receiving and transmitting links.
  • the uplink and downlink are not symmetrical. Therefore, if the TSN clock synchronization mechanism is to be adopted in the mobile network, multiple uplink and downlink transmission delays need to be compensated.
  • the link delay in the mobile network includes the air interface delay, and the delay of the transceiver link (that is, the uplink and downlink) on the air interface delay is asymmetric, which does not meet the requirements of the E2E time synchronization mechanism.
  • the embodiments of the present application provide a method for clock synchronization.
  • the symmetric air interface delay in the uplink and downlink is simulated, and then based on FIG. 11 and FIG.
  • the clock synchronization principle in 12 performs clock synchronization.
  • a technical solution of how to perform uplink and downlink delay compensation will be described in detail.
  • FIG. 13 shows a schematic diagram of a scenario to which an embodiment of the present application is applied.
  • the terminal device can use the E2E mechanism to synchronize the clock with the TSN clock source, and then the terminal device uses 802.1AS to synchronize the clock with the endpoint device.
  • the link delay between the UPF and the terminal device includes two segments, namely the air interface delay and the N3 delay.
  • the transceiver link in the air interface delay is asymmetric, so in this embodiment of the present application, the transceiver link needs to be compensated.
  • the difference between the downlink transmission delay and the uplink transmission delay of the mobile network can be recorded as D, as shown below:
  • the uplink and downlink transmission delay difference may be compensated into the time stamp t3, that is, the time information of the delay_resp sent by the master.
  • delaysm and delayms are as follows:
  • delaysm delay (UPF to RAN) + delay (RAN to UE)
  • delayms delay (UE to RAN) + delay (RAN to UPF)
  • the downlink and uplink delay difference D of the air interface can be expressed as:
  • D can be expressed as:
  • X delaysm_1-delaysm_2 can be written, and then according to the above two formulas (10) and (11), the following can be obtained:
  • the link dynamic delay difference may be compensated into the time stamp t7, that is, the time information of the SYNC message sent by the master.
  • delaysm_1 and delaysm_2 are as follows:
  • delaysm_1 delay (UPF to RAN) _1 + delay (RAN to UE) _1
  • delaysm_2 delay (UPF to RAN) _2 + delay (RAN to UE) _2
  • delaysm_1-delaysm_2 delay (RAN to UE) _1-delay (RAN to UE) _2.
  • the uplink and downlink delays on the air interface delay are compensated, so that the uplink and downlink delays after compensation are symmetrical, and the terminal device can synchronize with the TSN clock through the E2E mechanism.
  • the device then uses 802.1AS to synchronize with the endpoint device to synchronize the terminal device (or the TSN endpoint device connected to the terminal device) with the TSN clock source.
  • the link between the RAN and the UPF is symmetrical in uplink and downlink, and / or the link is a fixed link.
  • FIG. 14 shows an example of a specific synchronization method provided by an embodiment of the present application. It should be understood that FIG. 14 shows steps or operations of the synchronization method, but these steps or operations are only examples, and other operations or variations of the operations in FIG. 14 may be performed in the embodiments of the present application. In addition, each step in FIG. 14 may be performed in a different order from that presented in FIG. 14, and it may not be necessary to perform all operations in FIG. 14.
  • the same reference numerals in FIG. 14 as in FIG. 13 denote the same or similar meanings, and for the sake of brevity, they will not be repeated here.
  • the UPF sends a SYNC message to the RAN.
  • the UPF sends the SYNC message to the RAN at time t1, where t1 is TSN time.
  • the SYNC message may carry t1, N6 delay (delay_N6_link), and frequency ratio ratio1 of TSN clock to UPF local clock.
  • delay_N6_link N6 delay
  • frequency ratio ratio1 of TSN clock to UPF local clock t1, N6 delay (delay_N6_link), and frequency ratio ratio1 of TSN clock to UPF local clock.
  • the manner in which the UPF sends the SYNC message to the RAN can refer to the description in 601, and for the sake of brevity, it will not be repeated here.
  • the RAN receives the SYNC message, and triggers to determine the uplink and downlink delay compensation D of the air interface.
  • the uplink and downlink delay compensation D of the air interface is the difference between the air interface downlink delay (delay (RAN) to UE) and the air interface uplink delay (delay (UE to RAN)).
  • the SYNC message may be used to trigger the determination of uplink and downlink delay compensation of the air interface. Specifically, after the RAN recognizes that the received message is a SYNC message, it may trigger the determination of uplink and downlink delay compensation of the air interface, which may specifically include steps 1403 to 1411.
  • the RAN records the air interface time air_t1 corresponding to receiving the SYNC message.
  • the RAN sends a SYNC message to the terminal device through the air interface.
  • the terminal device returns the air interface time air_t2 for receiving the SYNC message to the RAN through the air interface.
  • the RAN determines the downlink air interface delay delay (RAN to UE).
  • the terminal device After receiving the SYNC message, the terminal device sends a delay_req message to the RAN, and the corresponding sending time is air_t3.
  • the outer layer of the delay_req message may encapsulate SDAP header and PDCP header.
  • air_t3 and air_t2 may be carried in the message sent to the RAN in step 1406. Specifically, air_t3 and air_t2 may be carried in the delay_Req message or in the outer encapsulation header of the delay_Req message, which is not limited in this embodiment of the present application.
  • the RAN receives the delay_req message. Specifically, the time when the RAN receives the delay_req message is air_t4.
  • the RAN after receiving the delay_req message sent by the terminal device, the RAN sends a delay_req message to the UPF through the N3 user plane connection.
  • the UPF receives the delay_req message, and the corresponding receiving time is t4.
  • the RAN determines the delay (UE to RAN).
  • the UPF sends a delay_resp message to the RAN through the N3 user plane connection, and the delay_resp message carries the time t4.
  • the RAN determines tx according to t4 in the delay_resp message, and the previously determined downlink air interface delay delay (RAN to UE) and uplink air interface delay delay (UE to RAN).
  • delay (RAN to UE) can be represented as delay_Uu_DL
  • uplink air interface delay delay (UE to RAN) can be represented as delay_Uu_UL.
  • tx is as follows:
  • tx t4 + (delay_Uu_DL-delay_Uu_UL).
  • the RAN sends a delay_resp message to the terminal device, carrying tx.
  • tx t4 + (delay_Uu_DL-delay_Uu_UL) ⁇ ratio.
  • the delay_req message and the delay_resp message are precision time protocol (PTP) messages.
  • PTP precision time protocol
  • the RAN can identify whether the received message is a PTP message. After that, the RAN can perform corresponding operations according to the type of the identified message.
  • the terminal device determines the offset according to tx. Specifically, the offset is as follows:
  • tx may be modified by UPF.
  • the RAN may send delay (RAN to UE) and delay (UE to RAN) to the UPF.
  • the RAN sends the difference between delay (RAN to UE) and delay (UE to RAN) (ie, delay_Uu_DL-delay_Uu_UL) to the UPF.
  • the above parameters are sent to the UPF through step 1407.
  • the UPF can derive tx according to t4, and the downlink air interface delay delay (RAN to UE) and uplink air interface delay delay (UE to RAN), or t4 according to t4 and delay_Uu_DL-delay_Uu_UL.
  • the UPF sends delay_resp to the terminal equipment through the RAN, carrying tx.
  • the uplink and downlink delays of the air interface link are compensated by RAN or UPF, so that the terminal device can achieve time synchronization with the TSN clock through the E2E mechanism, and then the terminal device uses 802.1AS to perform with the endpoint device Time synchronization to achieve time synchronization between the terminal device (or TSN endpoint device connected to the terminal device) and the TSN clock source.
  • FIG. 15 shows an example of a specific synchronization method provided by an embodiment of the present application. It should be understood that FIG. 15 shows steps or operations of the synchronization method, but these steps or operations are only examples, and other operations or variations of the operations in FIG. 15 may be performed in the embodiments of the present application. In addition, each step in FIG. 15 may be performed in a different order from that presented in FIG. 15, and it is possible that not all operations in FIG. 15 are to be performed.
  • the same reference numerals in FIG. 15 as in FIG. 13 indicate the same or similar meanings, and for the sake of brevity, they are not described here again.
  • the UPF sends a SYNC message to the RAN.
  • the UPF sends the SYNC message to the RAN at time t5, where t5 is TSN time.
  • the SYNC message may carry t5.
  • the UPF sends a follow_up message to the RAN immediately after the SYNC message.
  • the RAN receives the SYNC message, triggering the downlink air interface delay measurement.
  • the SYNC message may be used to trigger the determination of the downlink air interface delay measurement. Specifically, after the RAN recognizes that the received message is a SYNC message, it may trigger the determination of the downlink air interface delay measurement, which may specifically include steps 1503 to 1505.
  • step 703 for the manner in which the RAN recognizes the SYNC message, reference may be made to the description of step 703 in the foregoing, and for the sake of brevity, no further description is provided here.
  • the RAN records the air interface time air_t1 corresponding to receiving the SYNC message.
  • the RAN sends a SYNC message to the terminal device through the air interface.
  • the terminal device receives the SYNC message, and the reception time is t6, which is the local time of the terminal device.
  • the terminal device returns the air interface time air_t2 for receiving the SYNC message to the RAN through the air interface.
  • RAN determines delay (RAN to UE) _1, and delay (RAN to UE) _1 is as follows:
  • 1503 to 1505 can refer to the descriptions in 704 to 706, and for the sake of brevity, they are not repeated here.
  • the UPF executes 1506, that is, sends a follow_up message corresponding to the SYNC message in 1501 to the RAN, which may include time information t5.
  • the RAN After receiving the follow_up message, the RAN sends the follow_up message to the terminal device.
  • the UPF sends a SYNC message to the RAN.
  • the UPF sends the SYNC message to the RAN at time t7, where t7 is TSN time.
  • the SYNC message may carry t7.
  • the UPF sends a follow_up message to the RAN immediately after the SYNC message.
  • the RAN receives the SYNC message, triggering the downlink air interface delay measurement.
  • the RAN records the air interface time air_t3 corresponding to the reception of the SYNC message.
  • the RAN sends a SYNC message to the terminal device through the air interface.
  • the terminal device receives the SYNC message, and the reception time is t8, which is the local time of the terminal device.
  • the terminal device returns the air interface time air_t4 for receiving the SYNC message to the RAN through the air interface.
  • RAN determines delay (RAN to UE) _2, and delay (RAN to UE) _2 is as follows:
  • the UPF executes 1512, that is, sends a follow_up message corresponding to the SYNC message in 1507 to the RAN, which may include time information t7.
  • 1507 to 1512 can refer to the description in 1501 to 1506, and for the sake of brevity, they will not be repeated here.
  • the RAN derives tx according to the obtained t7 and the recorded delay (RAN to UE) _1 and delay (RAN to UE) _2, and tx is as follows:
  • tx t7- [delay (RAN to UE) _1-delay (RAN to UE) _2].
  • the RAN sends a follow_up message to the terminal device, which carries tx.
  • the terminal device determines the frequency ratio neighborRateRatio according to tx. Specifically, the neighborRateRatio is as follows:
  • the uplink and downlink delays of the air interface link are compensated by RAN or UPF, so that the terminal device can achieve frequency synchronization with the TSN clock through the E2E mechanism, and then the terminal device uses 802.1AS to perform with the endpoint device Frequency synchronization realizes the synchronization of the terminal device (or the TSN endpoint device connected to the terminal device) and the TSN clock source.
  • FIG. 16 shows an example of identifying a clock synchronization message provided by an embodiment of the present application. It should be understood that FIG. 16 shows steps or operations of the method for identifying a message, but these steps or operations are only examples, and other operations or variations of the operations in FIG. 16 may be performed in the embodiments of the present application. In addition, the various steps in FIG. 16 may be performed in a different order than that presented in FIG. 16, and it is possible that not all operations in FIG. 16 are to be performed.
  • the terminal device sends a session establishment request to SMF through RAN and AMF.
  • the session establishment request may include data network name (data, network name, DNN), single network slice selection auxiliary information (single network slice selection assistance, S-NSSAI) and other information.
  • the terminal device may send fourth indication information to the SMF, and the fourth indication information is used to indicate that the terminal device needs to synchronize with the TSN clock.
  • the SMF determines that the terminal device needs to be synchronized with the TSN clock, and allocates a special QFI for the clock synchronization message, that is, the QoS flow message corresponding to the special QFI is a clock synchronization message.
  • the special QFI may be, for example, the first QFI described above
  • the clock synchronization message may be, for example, a PTP message or an 802.1AS message.
  • SMF can determine whether the terminal device needs to synchronize with the TSN clock according to at least one of the following:
  • the SMF allocates a special QFI for the clock synchronization message.
  • the SMF determines that the DNN accessed by the terminal device needs to be clock synchronized with the TSN clock source
  • the SMF allocates a special QFI for the clock synchronization message.
  • SMF determines that the slice accessed by the terminal device (that is, S-NSSAI) needs to be clock synchronized with the TSN clock source
  • SMF allocates a special QFI for clock synchronization messages.
  • SMF sends an N4 session establishment request to UPF.
  • the N4 session establishment request carries a forwarding rule, and the forwarding rule is used to instruct the UPF to add the special QFI to the clock synchronization message (such as a PTP message or an 802.1AS message).
  • the forwarding rule may be, for example, the above policy information, such as source address and destination address.
  • UPF determines that the source or destination address of the received packet is consistent with the address information in the forwarding rule, it can determine that the packet is a clock synchronization packet, and then UPF can be included in the packet header of the packet.
  • the special QFI is added, and the special QFI can be further used to indicate to the RAN that the message is a clock synchronization message.
  • the UPF returns an N4 session establishment response.
  • the N4 session establishment response carries UPF tunnel information (tunnel info).
  • N2 session request carries N2 session management information (N2 SM info) and N1 session management information (N1 SM info).
  • N2SMinfo includes special QFI and UPF tunnel information.
  • the N1 SM info includes special QFI and packet filter.
  • the RAN triggers a radio resource control (RRC) connection establishment process with the terminal device.
  • RRC radio resource control
  • the RAN sends the N1 SM information obtained in 1102 to the terminal device.
  • the RAN and the terminal equipment store the correspondence between QFI and radio bearer.
  • RAN returns an N4 session response to SMF through AMF, which carries AN tunnel information.
  • AMF carries AN tunnel information.
  • Another example is the step of SMF triggering N4 session modification with UPF.
  • the RAN judges whether the received message is a clock synchronization message.
  • the clock synchronization message includes a downlink clock synchronization message, such as a SYNC message.
  • UPF When UPF sends a clock synchronization message, UPF judges that the message is a clock synchronization message according to the forwarding rules, then encapsulates the special QFI for the outer layer of the message and sends it to RAN;
  • the -RAN receives the DL message, judges that the DL message is a clock synchronization message according to the special QFI in the DL message header, and then triggers the corresponding operations, such as air interface delay measurement, N3 transmission delay measurement, and air interface uplink and downlink delay compensation Wait.
  • the RAN sends DL messages to the terminal equipment.
  • the terminal device receives the DL message, and recognizes that the received message corresponds to a special QFI according to the received wireless bearer, the stored wireless bearer and the QFI correspondence, thereby further determining that the received message is a clock synchronization message Accordingly, corresponding processing is performed, such as recording the air interface time corresponding to the received clock synchronization message.
  • the clock synchronization message includes an upstream clock synchronization message, such as delay_req.
  • the terminal device When the terminal device sends a clock synchronization message, it encapsulates the special QFI for the message and sends it to the RAN; or, the terminal device sends the message to the RAN through the radio bearer corresponding to the special QFI.
  • the -RAN determines the UL message as a clock synchronization message according to the QFI in the UL message header, or according to the correspondence between the radio bearer and QFI, and then triggers the corresponding operations, such as determining the downlink air interface delay and uplink air interface delay Wait.
  • the RAN sends the processed UL message to the UPF.
  • the UPF receives the UL message and performs corresponding processing, such as recording the time corresponding to receiving the UL message.
  • the SMF may also allocate special QFI to the clock synchronization message in other ways, which is not limited in the embodiment of the present application.
  • QFI may also be other parameters, such as a newly defined cell indicator, which indicates that the message is a clock synchronization message, which is not limited in the embodiment of the present application.
  • the SMF may allocate special QFIs to the clock synchronization message according to the instruction information of the terminal device, or contract information, or DNN / S-NSSAI, and the SMF may send this to the UPF, RAN, and terminal device.
  • QFI which forwards forwarding rules to UPF and terminal equipment, so that UPF can encapsulate the special QFI for clock synchronization messages, or terminal equipment can transmit clock synchronization messages on the radio channel corresponding to the special QFI, and then realize that RAN can Special QFI, or identify the clock synchronization message according to the wireless channel that transmits the message.
  • the 802.1AS protocol supports the transmission of clock synchronization messages in multicast mode.
  • the 802.1AS message contains domain information (domain), which indicates that the terminal device (or TSN end) station is time synchronized with the clock domain indicated by domain.
  • domain domain
  • the UPF when the UPF receives a multicast message (such as a SYNC message), it can determine the terminal device (or TSN end station) that needs to be synchronized according to the clock domain corresponding to the terminal device (or TSN end station), that is, the UPF is based on The clock domain corresponding to the terminal equipment (or TSN end) determines which terminal equipment to send 802.1AS messages to.
  • the UPF may obtain the clock domain corresponding to the terminal device (or TSN end) through the following steps 1 to 3:
  • Step 1 The SMF obtains the clock domain corresponding to the terminal device (or TSN end). Specifically, SMF can obtain the clock domain corresponding to the terminal device (or TSN end) in the following ways:
  • the terminal device sends the terminal device identification (UE ID) and domain ID to the SMF. or,
  • SMF obtains the correspondence between UE ID and domain ID from UDM. or,
  • SMF obtains the correspondence between UE ID and domain ID. or,
  • SMF obtains the correspondence between UE ID and domain ID from DN-AAA.
  • SMF receives the correspondence between UE ID and domain ID from AMF.
  • AMF can obtain the correspondence between UE ID and domain ID in the following ways:
  • the terminal device sends the terminal device identification (UE ID) and domain ID to the AMF.
  • UE ID terminal device identification
  • domain ID domain ID
  • AMF obtains the correspondence between UE ID and domain ID from UDM. or,
  • AMF obtains the correspondence between UE ID and domain ID from PCF. or,
  • Step 2 SMF sends the clock domain corresponding to the terminal device to the UPF, that is, SMF sends the correspondence between the terminal device and the clock domain to the UPF.
  • the terminal equipment can be identified by UE ID, such as SUPI, UE IP, UE MAC; clock domain, identified by domain ID.
  • the above-mentioned UE ID may also be a TSN end station ID, such as an APP ID, which is not limited in this embodiment of the present application.
  • Step 3 The UPF obtains the correspondence between the UE ID and the domain ID.
  • the UPF when the UPF receives the 802.1AS message, it can determine the UE ID to be synchronized according to the domain ID in the 802.1AS header and the correspondence between the UE ID and the domain ID. Then, the UPF realizes time synchronization between the terminal device and the clock domain through the synchronization method described in the embodiment of the present application.
  • the UPF, RAN, or terminal device includes a hardware structure and / or a software module corresponding to each function.
  • the embodiments of the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed by hardware or computer software driven hardware depends on the specific application and design constraints of the technical solution. A person skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the technical solutions of the embodiments of the present application.
  • the embodiments of the present application may divide the functional units of UPF, RAN, terminal equipment, etc. according to the above method examples, for example, each functional unit may be divided corresponding to each function, or two or more functions may be integrated into one processing unit in.
  • the above integrated unit may be implemented in the form of hardware or software functional unit. It should be noted that the division of the units in the embodiments of the present application is schematic, and is only a division of logical functions. In actual implementation, there may be another division manner.
  • FIG. 17 shows a possible exemplary block diagram of a communication device involved in an embodiment of the present application.
  • the device 1700 may exist in the form of software, hardware, or a combination of software and hardware. .
  • FIG. 17 shows a possible schematic block diagram of the device involved in the embodiment of the present application.
  • the device 1700 includes a processing unit 1702 and a communication unit 1703.
  • the processing unit 1702 is used to control and manage the operation of the device.
  • the communication unit 1703 is used to support communication between the device and other devices.
  • the device may further include a storage unit 1701 for storing program codes and data of the device.
  • the apparatus 1700 shown in FIG. 17 may be a UPF, RAN, or terminal device involved in an embodiment of this application.
  • the processing unit 1702 can support the device 1700 to perform the actions performed by the UPF in the above method examples.
  • the processing unit 1702 supports the device 1700 to perform 609 in FIG. 6, and / or use Other processes of the technology described herein.
  • the communication unit 1703 can support communication between the device 1700 and the RAN, etc.
  • the communication unit 1703 supports the device 1700 to perform steps 601, 603, 607, 608, and 611 in FIG. 6, and steps 701, 702, and 707 in FIG. 7, 801, 802, and 806 in FIG. 8, 1401, 1407, and 1409 in FIG. 14, 1501 and 1507 in FIG. 15, and / or other related communication processes.
  • the processing unit 1702 can support the device 1700 to perform the actions performed by the RAN in the above method examples.
  • the processing unit 1702 supports the device 1700 to perform 606 in FIG. 6 and FIG. 7 in FIG. 706,708,709, 906,907 in FIG. 9, 1405,1408,1410 in FIG. 14, 1505,1511,1510 in FIG. 15, and / or other processes for the techniques described herein.
  • the communication unit 1703 can support communication between the device 1700 and the UPF and the terminal device, etc.
  • the communication unit 1703 supports the device 1700 to perform steps 603 to 605, 611, 612 in FIG. 6 and steps 702, 704, 705 in FIG.
  • the processing unit 1702 can support the device 1700 to perform the actions performed by the terminal device in the above method examples.
  • the processing unit 1702 supports the device 1700 to execute 804, 805, 808 in FIG. 8, and FIG. 10 1004 to 1006 in FIG. 14, 1412 in FIG. 14, 1515 in FIG. 15, and / or other processes used in the techniques described herein.
  • the communication unit 1703 can support communication between the apparatus 1700 and the RAN or the endpoint device, etc.
  • the communication unit 1703 supports the apparatus 1700 to perform steps 604 to 605 and 612 in FIG. 6 and steps 704, 705 and 710 in FIG. 7. 803, 807 in 8, 903, 905, 908 in FIG. 9, 1002 in FIG. 10, 1403, 1404, 1406, 1411 in FIG. 14, 1503, 1509, 1514 in FIG. 15, and / or other related Communication process.
  • the processing unit 1702 may be a processor or a controller, for example, may be a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (Application -Specific Integrated Circuit (ASIC), Field Programmable Gate Array (FPGA) or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute various exemplary logical blocks, units, and circuits described in conjunction with the disclosure of the present application.
  • the processor may also be a combination of computing functions, for example, including one or more microprocessor combinations, a combination of DSP and microprocessor, and so on.
  • the communication unit 1703 may be a communication interface, which is a general term. In a specific implementation, the communication interface may include one or more interfaces.
  • the storage unit 1701 may be a memory.
  • the processing unit 1702 is a processor
  • the communication unit 1703 is a communication interface
  • the storage unit 1701 is a memory
  • the device 1700 involved in the embodiment of the present application may be the communication device 1800 shown in FIG. 18.
  • the device 1800 includes a processor 1802 and a communication interface 1803. Further, the device 1800 may further include a memory 1801. Optionally, the device 1800 may further include a bus 1804. Among them, the communication interface 1803, the processor 1802, and the memory 1801 can be connected to each other through a bus 1804; the bus 1804 can be a Peripheral Component Interconnect (PCI) bus or an extended industry standard structure (Extended Industry Standard Architecture, EISA) Bus etc.
  • PCI Peripheral Component Interconnect
  • EISA Extended Industry Standard Architecture
  • the bus 1804 can be divided into an address bus, a data bus, and a control bus. For ease of representation, only a thick line is used in FIG. 18, but it does not mean that there is only one bus or one type of bus.
  • the processor 1802 may execute various functions of the device 1800 by running or executing a program stored in the memory 1801.
  • the communication apparatus 1800 shown in FIG. 18 may be a UPF, RAN, or terminal device involved in the embodiments of the present application.
  • the processor 1802 may execute the actions completed by the UPF in the above method examples by running or executing a program stored in the memory 1801.
  • the processor 1802 may perform the actions performed by the RAN in the above method examples by running or executing a program stored in the memory 1801.
  • the processor 1802 may execute the actions completed by the terminal device in the foregoing method examples by running or executing a program stored in the memory 1801.
  • Time-aware systems can be divided into two categories: time-aware endpoint devices (time-aware end) and time-aware relays (time-aware relay).
  • the time-aware end station is, for example, the endpoint device 301 in FIG. 3, the endpoint device 401 in FIG. 4, or the endpoint device 1301 in FIG.
  • the time-aware relay is, for example, the relay network 31 in FIG. 3 (that is, time-aware relay 31), and the relay network 41 in FIG. 4 (that is, time-aware relay 41).
  • a time-aware system can support multiple clock domains.
  • a TSN network can have multiple clock domains, such as domain 0 and domain 1, where different clock domains are connected to different clock sources. Different clock sources have different time starting points or different time intervals.
  • a TSN bridge such as time-aware relay
  • a TSN station such as time-aware end
  • TSN network can belong to different clock domains at the same time.
  • the time-aware endpoint device is the start or end of time synchronization in the TSN network.
  • a time-aware endpoint device is not the main clock (that is, the clock source), it is the end of time synchronization and is used to receive time information.
  • a time-aware endpoint device is the main clock, it is the starting point for time synchronization and is used to send time information.
  • the master clock sends a clock synchronization message to all directly connected time-aware systems.
  • the clock synchronization message contains the current time.
  • Each time-aware system that receives the clock synchronization message corrects the time to compensate for transmission delay and processing delay.
  • the time-aware relay sends the corrected delay to all other directly connected time-aware systems. Specifically, for the correction of time, please refer to the description above.
  • the 802.1AS protocol supports the transmission of clock synchronization messages in a multicast manner.
  • the clock synchronization message may be a SYNC message, a delay_req message, a pdelay_req message, a pdelay_resp message, or a follow_up message, which is not limited in the embodiments of the present application.
  • the header of the clock synchronization message includes a domain number field, which is used to indicate the clock domain to which the clock that sends the time information belongs. In the embodiment of the present application, the domain number field in the message may also be referred to as a domain ID (domain ID) field.
  • FIG. 19 shows that an embodiment of the present application provides a method for sending a message, which can enable a mobile network to support the delivery of a multicast message.
  • the method shown in FIG. 19 includes 1910 to 1930.
  • the communication network element is a network element in a mobile network, such as UPF or RAN.
  • the communication network element receives the first message.
  • the first packet includes a domain identifier, and the domain identifier is used to identify a clock domain to which the node device that sends the first packet belongs.
  • the communication network element determines the user plane connection corresponding to the first packet according to the correspondence between the domain identifier and the user plane connection identifier, and the domain identifier in the first packet.
  • the communication network element sends the first message to the terminal device through the user plane connection corresponding to the first message.
  • the communication network element in the mobile network may determine the user corresponding to the first packet according to the correspondence between the domain ID (domain ID) and the user plane connection ID, and the domain ID in the first packet Plane connection, and then send the first message to the terminal device through the user plane connection, where the first message is a multicast message. Therefore, the embodiments of the present application can enable the communication network element in the mobile network to send the multicast message.
  • the communication network element receives the correspondence between the domain identifier from the SMF and the user plane connection identifier.
  • FIG. 20 shows that an embodiment of the present application provides a method for sending a message, which can enable a mobile network to support the delivery of a multicast message.
  • the methods shown in Figure 20 include 2010 and 2020.
  • the communication network element is a network element in a mobile network, such as UPF or RAN.
  • SMF determines the correspondence between the domain identifier and the user plane connection identifier, where the domain identifier is used to identify the clock domain to which the node device that sends the first message belongs.
  • SMF sends the correspondence between the domain identifier and the user plane connection identifier to the communication network element, where the correspondence is used by the communication network element to determine the user plane connection to send the first message to the terminal device .
  • the SMF sends the correspondence between the domain identifier and the user plane connection to the communication network element, so that the communication network element can determine the user plane connection for sending the first message according to the correspondence, and then pass The user plane connection sends the first message to the terminal device, where the first message is a multicast message. Therefore, the embodiments of the present application can enable the communication network element in the mobile network to send the multicast message.
  • the SMF determining the correspondence between the domain ID and the user plane connection ID includes:
  • the SMF obtains the correspondence between the terminal device identifier and the user plane connection identifier
  • the SMF obtains the correspondence between the terminal device ID and the domain ID, where the domain ID is used to identify the clock domain corresponding to the terminal device;
  • the SMF determines the correspondence between the domain ID and the user plane connection identifier according to the correspondence between the terminal device ID and the user plane connection ID, and the correspondence between the terminal device ID and the domain ID.
  • the SMF determining the correspondence between the domain ID and the user plane connection ID includes:
  • the SMF obtains the correspondence between the user plane connection identifier of the terminal device and the network identifier, where the network identifier is used to identify the network that the terminal device accesses;
  • the SMF obtains the correspondence between the network identifier and the domain identifier, and the domain identifier is used to identify the clock domain corresponding to the terminal device;
  • the SMF determines the correspondence between the domain identifier and the user plane connection identifier according to the correspondence between the user plane connection identifier and the network identifier, and the correspondence between the network identifier and the domain identifier.
  • the network identifier includes at least one of the following: a data network name DNN, single network slice selection auxiliary information S-NSSAI.
  • the first message is a clock synchronization message.
  • the user plane connection identifier includes at least one of the following: a session identifier and user plane tunnel information.
  • FIG. 21 shows an example of sending a message provided by an embodiment of the present application.
  • the UPF is based on the correspondence between the domain ID (domain ID) and the user plane connection ID, and the domain in the first packet. Identifier to determine the user plane connection corresponding to the first message, and then send the first message to the terminal device through the user plane connection.
  • the embodiments of the present application may be used in the scenario in FIG. 3 above.
  • FIG. 21 shows steps or operations of the method for sending a message, but these steps or operations are merely examples, and other operations or variations of the operations in FIG. 21 may be performed in the embodiments of the present application. In addition, each step in FIG. 21 may be performed in a different order from that presented in FIG. 21, and it is possible that not all operations in FIG. 21 are to be performed.
  • the terminal device sends a NAS message to the AMF through the RAN.
  • the NAS message carries a session ID (session ID), DNN, S-NSSAI, and session establishment request.
  • the correspondence between the terminal device ID and the domain ID can also be carried in the NAS message.
  • the terminal device identifier may be a media access control (media access control (MAC) address, terminal user permanent identifier (SUPI), general public user identifier (GPSI) or Internet protocol (Internet Protocol Internet protocol (IP) address, etc., this embodiment of the present application does not limit this.
  • the AMF sends a request message for creating a session management context to the SMF.
  • the creation session management context request message carries the SUPI of the terminal device and the parameters in step 2101.
  • the corresponding relationship between the terminal device ID and the domain ID is also carried in the create session management context request message.
  • the SMF obtains the correspondence between the terminal device ID and the session ID according to the create session management context request message.
  • the SMF may also obtain the correspondence between the session ID of the terminal device and the network ID according to the request for creating a session management context.
  • the network identifier is, for example, at least one of the following: the data network name DNN, the single network slice selection auxiliary information S-NSSAI, etc., or other identifiers used to identify the network that the terminal device accesses. The embodiment does not limit this.
  • the SMF may also save the obtained corresponding relationship.
  • a special QFI may be allocated for the clock synchronization message, that is, the QoS flow message corresponding to the special QFI is a clock synchronization message.
  • SMF can save the correspondence between session ID and special QFI.
  • SMF determines the correspondence between domain ID and session ID.
  • the SMF may determine the correspondence between the domain ID and the session ID according to the correspondence between the terminal device ID and the session ID, and between the terminal device ID and the domain ID.
  • the SMF can obtain the correspondence between the terminal device ID and the domain ID carried in the request message for creating a session management context.
  • SMF can also obtain the correspondence between the terminal device ID and domain ID from UDM, or SMF can obtain the correspondence between the terminal device ID and domain ID from DN-AAA.
  • the terminal device accesses the network through session1, and SMF stores the correspondence between the terminal device MAC and session1.
  • SMF can obtain the correspondence between the terminal device MAC and domain1 from UDM. Therefore, SMF can determine the correspondence between session1 and domain1.
  • the terminal device may meet the following limiting conditions: one terminal device MAC can only access one domain, and one terminal device can only establish one session.
  • the SMF may determine the corresponding relationship between the domain ID and the session ID according to the corresponding relationship between the session ID and the network ID, and the corresponding relationship between the network ID and the domain ID.
  • the SMF can obtain the correspondence between the network ID and the domain ID in the following ways: (1) configure the correspondence between the network ID and the domain ID on the SMF, or (2) obtain the correspondence between the network ID and the domain ID from the UDM. Further, the SMF obtains the correspondence between the terminal device ID, the network ID, and the domain ID. Then, the SMF determines the correspondence between the domain ID and the session ID according to the correspondence between the session ID and the network ID saved in step 2103.
  • the terminal device has established three sessions, namely session1, session2, and session3, and accesses DNN1, DNN2, and DNN3 through these three sessions, respectively.
  • DNN1 corresponds to domain1
  • DNN2 corresponds to domain2
  • DNN3 corresponds to domain3.
  • SMF saves the correspondence between DNN and session ID, as shown in Table 3.
  • SMF is configured with the correspondence between terminal devices MAC, DNN and domain ID, as shown in Table 4. Therefore, SMF can determine the correspondence between session ID (session ID) and domain ID (domain ID) according to Table 3 and Table 4, As shown in Table 5.
  • the terminal device may satisfy the following limiting conditions: one terminal device MAC can access at least one domain, and one terminal device MAC can establish at least one session, but one DNN can only correspond to one domain.
  • the SMF when the SMF is assigned a special QFI, the SMF may determine the correspondence between the session ID, QFI, and domain ID.
  • SMF sends an N4 session establishment request to UPF.
  • the N4 session establishment request carries the correspondence between domain ID and user plane connection identifier.
  • the user plane connection identifier refers to the N4 session identifier (N4 session ID).
  • N4 session ID corresponds to session ID.
  • the N4 session establishment request may carry the correspondence between domain ID, special QFI and user plane connection identifier.
  • the N4 session establishment request also carries packet detection rules, usage reporting rules, and so on.
  • the special QFI may be included in the packet detection rule.
  • the above N4 session establishment request also carries core network tunnel information (CN tunnel info).
  • the user plane connection identifier may be any one or more of the following: N4 session identifier, core network tunnel information.
  • UPF returns an N4 session establishment response to SMF.
  • the N4 session establishment response carries the core network tunnel information.
  • SMF sends an N1N2 messaging message to AMF, which carries session ID, N2 SM info, N1 SM info, etc.
  • N2 SM contains info session ID, CN tunnel info, S-NSSAI, etc .
  • N1 SM info contains session establishment acceptance, S-NSSAI, DNN, etc.
  • the AMF sends an N2 session request to the RAN, which carries the parameters in step 2107.
  • the RAN initiates an air interface establishment process between it and the terminal device.
  • the RAN returns an N2 session response, carrying the session ID, access network tunnel information (RAN tunnel info), etc.
  • the AMF sends an update session management context request to the SMF, carrying the parameters in 1.
  • SMF sends an N4 session modification request to UPF, carrying access network tunnel information.
  • the N4 session modification request also carries domainID.
  • the domain ID and the access network tunnel information are corresponding.
  • the N4 session modification request also carries the correspondence between domain ID and user plane connection identifier.
  • the user plane connection identifier may be any one or more of the following: access network tunnel information, N4 session identifier, and core network tunnel information.
  • the correspondence between the domain ID and the user plane connection can be delivered in step 2104, or it can be delivered in this step. Specifically, it is delivered in different steps, and the specific value of the user plane connection is different.
  • the user plane connection identifier may be at least one slap in the N4 session ID, and CN tunnel information. Delivered in step 3, the user plane connection identifier may be at least one of N4 session ID, CN tunnel info, and AN tunnel info.
  • the UPF receives the first message.
  • the first message is a multicast message. Specifically, the first message is a clock synchronization message.
  • the UPF determines the user plane connection corresponding to the first packet according to the domain ID field in the first packet, and the correspondence between the domain ID and the user plane connection identifier, so that the first packet is sent to the terminal device through the user plane connection Text.
  • the UPF may encapsulate a special QFI corresponding to the user plane connection identifier on the outer layer of the clock synchronization message to indicate that the message is a clock synchronization message.
  • the UPF after receiving the multicast message, the UPF can determine the user plane connection corresponding to the message according to the domain ID in the multicast message, so that the user plane connection is sent to the terminal device through the user plane connection. Broadcast message.
  • the UPF does not need to determine the terminal device to be synchronized first, and the processing logic is relatively simple.
  • FIG. 22 shows an example of sending a packet provided by an embodiment of the present application.
  • the RAN according to the correspondence between the domain ID (domain ID) and the user plane connection ID, and the domain in the first packet Identifier to determine the user plane connection corresponding to the first message, and then send the first message to the terminal device through the user plane connection.
  • domain ID domain ID
  • the embodiments of the present application may be used in the scenario in FIG. 4 above.
  • FIG. 22 shows steps or operations of the method for sending a message, but these steps or operations are only examples, and other operations or variations of the operations in FIG. 22 may be performed in the embodiments of the present application. In addition, each step in FIG. 22 may be performed in a different order than that presented in FIG. 22, and it is possible that not all operations in FIG. 22 are to be performed.
  • the terminal device sends a NAS message to the AMF through the RAN.
  • the NAS message carries a session ID (session ID), DNN, S-NSSAI, and session establishment request.
  • the AMF sends a request message for creating a session management context to the SMF.
  • the creating session management context request message carries the SUPI of the terminal device and the parameters in step 2201.
  • the SMF obtains the correspondence between the terminal device ID and the session ID according to the create session management context request message.
  • SMF determines the correspondence between domain ID and session ID.
  • 2201-2204 may refer to the description in 2101-2104 in FIG. 21, and for the sake of brevity, no further description is provided here.
  • SMF sends an N4 session establishment request to UPF.
  • the N4 session establishment request carries message detection rules, reporting rules, etc.
  • the message detection rules may include the special QFI.
  • the N4 session establishment request When the tunnel information is distributed by SMF, the N4 session establishment request also carries the core network tunnel information (CN tunnel info).
  • the UPF returns an N4 session establishment response to the SMF.
  • the N4 session establishment response carries the core network tunnel information.
  • SMF sends an N1N2 messaging message to AMF, which carries session ID, N2 SM info, N1 SM info, etc.
  • N2SMinfo contains at least one of QFI, 5G service quality identifier (5G QoS Identifier, 5QI), S-NSSAI, session identifier and core network tunnel information.
  • N1 SM info can include session establishment acceptance, S-NSSAI, DNN, etc.
  • N2SMinfo also carries a domain ID. Further, N2 SM carries the correspondence between domain ID and user plane connection identifier.
  • the user plane connection identifier may be one or more of the following: session identifier, core network tunnel information, QFI, 5QI.
  • the AMF sends an N2 session request to the RAN, which carries the parameters in step 2207.
  • the RAN initiates an air interface establishment process between it and the terminal device.
  • the RAN assigns an air interface user plane connection identifier.
  • the air interface user plane connection identifier may be a data radio bearer (Data Radio Bearer, DRB) ID.
  • DRB Data Radio Bearer
  • the RAN obtains the correspondence between the domain ID and the DRB ID.
  • the RAN obtains the correspondence between the domain ID and the user plane connection identifier, and the user plane connection identifier may be DRB ID.
  • the RAN receives the first message.
  • the first message is a multicast message, for example, a clock synchronization message.
  • the RAN determines the user plane connection corresponding to the first packet according to the domain ID field in the first packet, and the correspondence between the domain ID and the user plane connection identifier, so as to send the first report to the terminal device through the user plane connection Text.
  • the RAN after receiving the multicast message, the RAN can determine the user plane connection corresponding to the message according to the domain ID in the multicast message, so that the user plane connection is sent to the terminal device through the user plane connection. Broadcast message.
  • the RAN does not need to determine the terminal device to be synchronized first, and the processing logic is relatively simple.
  • the UPF, RAN, or SMF includes hardware structures and / or software modules corresponding to performing each function.
  • the embodiments of the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed by hardware or computer software driven hardware depends on the specific application and design constraints of the technical solution. A person skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the technical solutions of the embodiments of the present application.
  • the embodiments of the present application may divide the functional units of UPF, RAN, or SMF according to the above method examples, for example, each functional unit may be divided corresponding to each function, or two or more functions may be integrated into one processing unit .
  • the above integrated unit may be implemented in the form of hardware or software functional unit. It should be noted that the division of the units in the embodiments of the present application is schematic, and is only a division of logical functions. In actual implementation, there may be another division manner.
  • FIG. 23 shows a possible exemplary block diagram of a communication device involved in an embodiment of the present application.
  • the device 2300 may exist in the form of software, hardware, or a combination of software and hardware. .
  • FIG. 23 shows a possible schematic block diagram of the device involved in the embodiment of the present application.
  • the device 2300 includes a processing unit 2302 and a communication unit 2303.
  • the processing unit 2302 is used to control and manage the operation of the device.
  • the communication unit 2303 is used to support communication between the device and other devices.
  • the device may further include a storage unit 2301 for storing program codes and data of the device.
  • the device 2300 shown in FIG. 23 may be the UPF, RAN, or SMF involved in the embodiment of the present application.
  • the processing unit 2302 can support the device 2300 to perform the actions performed by the UPF in the above method examples.
  • the processing unit 2302 supports the device 2300 to perform 2112 in FIG. 21, and / or use Other processes of the technology described herein.
  • the communication unit 2303 can support communication between the device 2300 and SMF, etc.
  • the communication unit 2303 supports the device 2300 to perform steps 2105, 2106, 2111 in FIG. 21, and / or other related communication processes.
  • the processing unit 2302 can support the device 2300 to perform the actions performed by the RAN in the above method examples.
  • the processing unit 2302 supports the device 2300 to perform 2212 in FIG. 22, and / or use Other processes of the technology described herein.
  • the communication unit 2303 can support communication between the device 2300 and the UPF and the terminal device.
  • the communication unit 2303 supports the device 2300 to perform steps 2208, 2211 in FIG. 22, and / or other related communication processes.
  • the processing unit 2302 can support the device 2300 to perform the actions performed by the SMF in the above method examples. 2203, 2204, and / or other processes for the techniques described herein.
  • the communication unit 2303 can support communication between the device 2300 and the RAN or the endpoint device, etc.
  • the communication unit 2303 supports the device 2300 to perform steps 2102, 2105, 2106, and 2107 in FIG. , 2207, and / or other related communication processes.
  • the processing unit 2302 may be a processor or a controller, for example, may be a central processing unit (Central Processing Unit, CPU), a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (Application -Specific Integrated Circuit (ASIC), Field Programmable Gate Array (FPGA) or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute various exemplary logical blocks, units, and circuits described in conjunction with the disclosure of the present application.
  • the processor may also be a combination of computing functions, for example, a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and so on.
  • the communication unit 2303 may be a communication interface.
  • the communication interface is a general term. In a specific implementation, the communication interface may include one or more interfaces.
  • the storage unit 2301 may be a memory.
  • the processing unit 2302 is a processor
  • the communication unit 2303 is a communication interface
  • the storage unit 2301 is a memory
  • the device 2300 involved in the embodiment of the present application may be the communication device 2400 shown in FIG. 24.
  • the device 2400 includes a processor 2402 and a communication interface 2403. Further, the device 2400 may also include a memory 2401. Optionally, the device 2400 may further include a bus 2404. Among them, the communication interface 2403, the processor 2402, and the memory 2401 can be connected to each other through a bus 2404; the bus 2404 can be a peripheral component interconnection standard (Peripheral Component Interconnect, PCI) bus or an extended industry standard structure (Extended Industry Standard Architecture, EISA) Bus etc.
  • PCI peripheral component interconnection standard
  • EISA Extended Industry Standard Architecture
  • the bus 2404 can be divided into an address bus, a data bus, and a control bus. For ease of representation, only a thick line is used in FIG. 24, but it does not mean that there is only one bus or one type of bus.
  • the processor 2402 may execute various functions of the device 2400 by running or executing a program stored in the memory 2401.
  • the communication device 2400 shown in FIG. 24 may be a UPF, RAN, or terminal device involved in an embodiment of the present application.
  • the processor 2402 may execute the actions performed by the UPF in the above method examples by running or executing a program stored in the memory 2401.
  • the processor 2402 may execute the actions performed by the RAN in the above method examples by running or executing a program stored in the memory 2401.
  • the processor 2402 may execute the actions completed by the SMF in the above method examples by running or executing a program stored in the memory 2401.
  • the embodiments of the application also provide a computer-readable storage medium, including a computer program, which, when the computer program runs on a computer, causes the computer to execute the method provided by the foregoing method embodiments.
  • Embodiments of the present application also provide a computer program product containing instructions, which, when the computer program product runs on a computer, causes the computer to execute the method provided by the foregoing method embodiment.
  • An embodiment of the present application further provides a chip, which can be applied to a communication device.
  • the chip includes at least one processor. When the at least one processor executes an instruction, the chip or the communication device executes the above method. Methods.
  • the chip may also include a memory, which may be used to store the instructions involved.
  • the processor mentioned in the embodiment of the present invention may be a central processing unit (Central Processing Unit, CPU), and may also be other general-purpose processors, digital signal processors (Digital Signal Processor, DSP), and special integrated circuits ( Application Specific (Integrated Circuit, ASIC), ready-made programmable gate array (Field Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc.
  • the general-purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
  • the disclosed system, device, and method may be implemented in other ways.
  • the device embodiments described above are only schematic.
  • the division of the units is only a division of logical functions.
  • there may be other divisions for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented.
  • the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.
  • the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or may be 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.
  • each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit.
  • 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.
  • the technical solution of the present application essentially or part of the contribution to the existing technology or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including Several instructions are used to enable a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in the embodiments of the present application.
  • the aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM), random access memory (random access memory, RAM), magnetic disk or optical disk and other media that can store program codes .

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Abstract

本申请提供一种同步的方法和装置，能够在移动网络中实现与TSN时钟同步。该同步的方法由中继网络中的第一网元执行，所述中继网络包括无线接入网RAN设备和终端设备，该方法包括：所述第一网元接收时钟同步报文；所述第一网元确定所述中继网络的第一时间，所述中继网络的第一时间包括所述RAN设备与所述终端设备之间传输所述时钟同步报文的第一下行传输时延；所述第一网元确定所述中继网络的时间修正域，所述时间修正域包括所述第一下行传输时延。

Description

同步的方法和装置
本申请要求于2019年1月14日提交中国专利局、申请号为201910032550.4、申请名称为“同步的方法和装置”的中国专利申请，以及，于2018年11月21日提交中国专利局、申请号为201811393993.8、申请名称为“同步的方法和装置”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及通信领域，并且更具体的，涉及通信领域中的同步的方法和装置。
背景技术
大部分工业场景，如工厂自动化(factory automation)，对时延、抖动、错误率等有严格要求。为满足工业场景要求，IEEE研究了一种可以用用在工业工厂中的以太网络--时间敏感网络(time sensitive networking，TSN)。TSN网络中，采用802.1AS协议实现高精度时间同步要求。移动网络也可以应用到工业场景，即移动网络终端需要与TSN时钟进行同步。
因此，如何在移动网络中实现与TSN时钟进行同步是亟需解决的问题。
发明内容
本申请提供一种同步的方法和装置，能够在移动网络中实现与TSN时钟同步。
第一方面，提供了一种同步的方法，该方法由中继网络中的第一网元执行，所述中继网络包括无线接入网RAN设备和终端设备，该方法包括：
所述第一网元接收时钟同步报文；
所述第一网元确定所述中继网络的第一时间，所述中继网络的第一时间包括所述RAN设备与所述终端设备之间传输所述时钟同步报文的第一下行传输时延；
所述第一网元确定所述中继网络的时间修正域，所述时间修正域包括所述第一下行传输时延。
本申请实施例中，第一网元可以根据时钟同步报文，确定中继网络的时间修正域，该时间修正域包括RAN设备与终端设备之间传输该时钟同步报文对应的第一下行传输时延，从而有助于实现在移动网络中采用TSN时钟同步机制对终端设备或端点设备进行其与外部时钟的时钟同步。
结合第一方面，在第一方面的某些实现方式中，所述时钟同步报文用于触发所述第一网元确定所述中继网络的第一时间。这样，当第一网元识别接收到的报文为SYNC报文之后，可以触发确定中继网络的驻留时间。
结合第一方面，在第一方面的某些实现方式中，所述时间修正域还包括发送所述时钟同步报文的节点设备与所述中继网络之间的第二下行传输时延。这样，在移动网络中可以 采用TSN时钟同步机制对终端设备或端点设备进行其与外部时钟的时钟同步。
结合第一方面，在第一方面的某些实现方式中，所述中继网络中还包括UPF，其中，所述第一时间还包括所述UPF与所述RAN设备之间的第三下行传输时延。
本申请实施例中，当中继网络包括UPF、RAN和终端设备时，第一网元可以为UPF、RAN或终端设备。当中继网络包括RAN和终端设备时，第一网元可以为RAN或终端设备。
结合第一方面，在第一方面的某些实现方式中，所述第一时间为所述第一下行传输时延与所述第三下行传输时延之和。
结合第一方面，在第一方面的某些实现方式中，所述第一网元为所述UPF，所述第一网元确定所述中继网络的第一时间，包括：
所述UPF获取所述第三下行传输时延；
所述UPF向所述RAN设备发送所述时钟同步报文和第一指示信息，所述第一指示信息用于指示所述RAN设备获取所述第一下行传输时延；
所述UPF从所述RAN设备接收所述第一下行传输时延；
所述UPF根据所述第一下行传输时延和所述第三下行传输时延，确定所述第一时间。
对应的，所述RAN设备接收所述UPF设备发送的时钟同步报文和第一指示信息，根据所述时钟同步报文和所述第一指示信息，确定所述第一下行传输时延，然后所述RAN设备向所述UPF设备发送所述第一下行传输时延。
因此，本申请实施例中，将终端设备、RAN和UPF作为一个中继网络，并由该中继网络中的UPF确定该中继网络传输SYNC报文的“内部时延”，即从UPF接收SYNC报文，到终端设备接收SYNC报文的时间，实现终端设备(或者与该终端设备连接的TSN端点设备)与TSN时钟源的时间同步。
结合第一方面，在第一方面的某些实现方式中，所述第一指示信息包括第一QFI，所述第一指示信息用于指示所述RAN设备接收到所述第一QFI对应的报文时，获取所述第一下行传输时延。
这里，第一QFI即特殊QFI，即，第一QFI对应的QoS流报文为时钟同步报文，例如SYNC报文。也就是说，当RAN接收到的报文中包括第一QFI时，RAN可以识别出该报文为SYNC报文，然后可以触发第一下行传输时延的测量。
结合第一方面，在第一方面的某些实现方式中，所述第一网元确定所述中继网络的第一时间，包括：
所述第一网元根据策略信息，确定所述中继网络的第一时间，其中，所述策略信息为配置在所述第一网元上的信息，或者所述第二策略信息为从SMF接收的信息。
具体的，在中继网络包括RAN设备和终端设备的情况下，此时该第一网元可以为RAN；在中继网络包括UPF设备、RAN设备和终端设备的情况下，此时该第一网元可以为UPF设备或RAN设备。
结合第一方面，在第一方面的某些实现方式中，所述第一网元为所述RAN设备，所述第一网元确定所述中继网络的第一时间，包括：
所述RAN设备接收第二指示信息，所述第二指示信息用于指示所述RAN设备获取所述第一时间；
所述RAN根据所述第二指示信息，获取所述第一下行传输时延和所述第三下行传输时延；
所述RAN根据所述第一下行传输时延和所述第三下行传输时延，确定所述第一时间。
因此，本申请实施例中，将终端设备、RAN和UPF作为一个中继网络，并由该中继网络中的RAN确定该中继网络传输SYNC报文的“内部时延”，即从UPF接收SYNC报文，到终端设备接收SYNC报文的时间，实现终端设备(或者与该终端设备连接的TSN端点设备)与TSN时钟源的时间同步。
结合第一方面，在第一方面的某些实现方式中，所述第二指示信息包括第二QFI，所述第二指示信息用于指示所述RAN设备接收到所述第二QFI对应的报文时，获取所述第一时间。
其中，第二QFI对应的QoS流报文为时钟同步报文，即SYNC报文。也就是说，当RAN接收到的报文中包括第二QFI时，RAN可以识别出该报文为SYNC报文，然后可以触发获取中继网络的驻留时间。
结合第一方面，在第一方面的某些实现方式中，所述第一网元确定所述第一时间包括：
所述第一网元根据所述第一网元与发送所述时钟同步报文的节点设备之间的频率比率，确定所述第一时间。
结合第一方面，在第一方面的某些实现方式中，还包括：所述第一网元向所述终端设备发送消息，所述消息携带所述时间修正域。
第二方面，提供了一种同步的方法，该方法由中继网络中的RAN设备执行，所述中继网络包括UPF设备、所述RAN设备和终端设备，该方法包括：
所述RAN设备接收所述UPF设备发送的时钟同步报文和第一指示信息，所述第一指示信息用于指示所述RAN设备获取第一下行传输时延，所述第一下行传输时延为所述RAN设备与所述终端设备之间传输所述时钟同步报文的时延；
所述RAN设备根据所述时钟同步报文和所述第一指示信息，确定所述第一下行传输时延；
所述RAN设备向所述UPF设备发送所述第一下行传输时延。
因此，本申请实施例中，将终端设备、RAN和UPF作为一个中继网络，当由该中继网络中的UPF确定该中继网络传输SYNC报文的“内部时延”，即从UPF接收SYNC报文，到终端设备接收SYNC报文的时间时，可以触发RAN设备确定第一下行传输时延，从而有助于实现终端设备(或者与该终端设备连接的TSN端点设备)与TSN时钟源的时间同步。
结合第二方面，在第二方面的某些实现方式中，所述第一指示信息包括第一QFI，所述第一指示信息具体用于指示所述RAN设备接收到所述第一QFI对应的报文时，获取所述第一下行传输时延。
第三方面，提供了一种同步的装置，该装置包括用于执行第一方面或第一方面的任意一种可能的实现方式中的同步的方法的模块或单元。
第四方面，提供了一种同步的装置，该装置包括用于执行第二方面或第二方面的任意一种可能的实现方式中的同步的方法的模块或单元。
第五方面，提供了一种同步的装置，该装置包括处理器和收发器，处理器用于执行程 序，当处理器执行程序是，处理器和收发器实现第一方面或第一方面的任意一种可能的实现方式中的同步的方法。
可选的，该同步的装置还可以包括存储器，存储器用于存储处理器执行的程序。
该同步的装置的一种示例为RAN设备、UPF设备或终端设备。
第六方面，提供了一种同步的装置，该装置包括处理器和收发器，处理器用于执行程序，当处理器执行程序是，处理器和收发器实现第二方面或第二方面的任意一种可能的实现方式中的同步的方法。
可选的，该同步的装置还可以包括存储器，存储器用于存储处理器执行的程序。
该同步的装置的一种示例为RAN设备。
第七方面，提供一种计算机可读存储介质，该计算机可读存储介质存储用于同步的装置执行的程序代码，该程序代码包括用于实现第一方面或第一方面的任意一种可能的实现方式中的同步的方法的指令。
第八方面，提供一种计算机可读存储介质，该计算机可读存储介质存储用于同步的装置执行的程序代码，该程序代码包括用于实现第二方面或第二方面的任意一种可能的实现方式中的同步的方法的指令。
第九方面，提供一种芯片，该芯片包括处理器和通信接口，该通信接口用于与外部器件进行同行，该处理器用于实现第一方面或第一方面的任意一种可能的实现方式中的同步的方法。
可选地，该芯片还可以包括存储器，该存储器中存储有指令，处理器用于执行存储器中存储的指令，当该指令被执行时，处理器用于实现第一方面或第一方面的任意一种可能的实现方式中的同步的方法。
可选地，该芯片可以集成在RAN设备、UPF设备或终端设备上。
第十方面，提供一种芯片，该芯片包括处理器和通信接口，该通信接口用于与外部器件进行通信，该处理器用于实现第二方面或第二方面的任意一种可能的实现方式中的同步的方法。
可选地，该芯片还可以包括存储器，该存储器中存储有指令，处理器用于执行存储器中存储的指令，当该指令被执行时，处理器用于实现第二方面或第二方面的任意一种可能的实现方式中的同步的方法。
可选地，该芯片可以集成在RAN设备上。
第十一方面，提供了一种发送报文的方法，包括：
通信网元接收第一报文，其中，所述第一报文包括域标识，所述域标识用于标识发送所述第一报文的节点设备所属的时钟域；
所述通信网元根据域标识与用户面连接标识的对应关系，以及所述第一报文中的域标识，确定所述第一报文对应的用户面连接；
所述通信网元通过所述第一报文对应的用户面连接向终端设备发送所述第一报文。
结合第十一方面，在第十一方面的某些实现方式中，还包括：
所述通信网元接收来自SMF的所述域标识与用户面连接标识的对应关系。
结合第十一方面，在第十一方面的某些实现方式中，所述通信网元为UPF或RAN。
结合第十一方面，在第十一方面的某些实现方式中，所述第一报文为时钟同步报文。
结合第十一方面，在第十一方面的某些实现方式中，所述用户面连接标识包括以下至少一种：会话标识、用户面隧道信息。
第十二方面，提供了一种发送报文的方法，包括：
SMF确定域标识和用户面连接标识的对应关系，所述域标识用于标识发送第一报文的节点设备所属的时钟域；
所述SMF将所述对应关系发送至通信网元，其中，所述对应关系用于所述通信网元确定向终端设备发送所述第一报文的用户面连接。
结合第十二方面，在第十二方面的某些实现方式中，所述SMF确定域标识和用户面连接标识的对应关系，包括：
所述SMF获取终端设备标识和用户面连接标识的对应关系；
所述SMF获取终端设备标识和域标识的对应关系，其中，所述域标识用于标识所述终端设备对应的时钟域；
所述SMF根据终端设备标识和用户面连接标识的对应关系，以及，终端设备标识和域标识的对应关系，确定域标识和用户面连接标识的对应关系。
结合第十二方面，在第十二方面的某些实现方式中，所述SMF确定域标识和用户面连接标识的对应关系，包括：
所述SMF获取所述终端设备的用户面连接标识以及网络标识的对应关系，其中，所述网络标识用于标识所述终端设备接入的网络；
所述SMF获取网络标识和域标识的对应关系，所述域标识用于标识所述终端设备对应的时钟域；
所述SMF根据所述用户面连接标识以及网络标识的对应关系，以及，网络标识和域标识的对应关系，确定域标识和用户面连接标识的对应关系。
结合第十二方面，在第十二方面的某些实现方式中，所述网络标识包括以下至少一种：数据网络名称DNN、单网络切片选择辅助信息S-NSSAI。
结合第十二方面，在第十二方面的某些实现方式中，所述通信网元为UPF或RAN。
结合第十二方面，在第十二方面的某些实现方式中，所述第一报文为时钟同步报文。
结合第十二方面，在第十二方面的某些实现方式中，所述用户面连接标识包括以下至少一种：会话标识、用户面隧道信息。
第十三方面，提供了一种发送报文的装置，该装置包括用于执行第十一方面或第十一方面的任意一种可能的实现方式中的发送报文的方法的模块或单元。
第十四方面，提供了一种发送报文的装置，该装置包括用于执行第十二方面或第十二方面的任意一种可能的实现方式中的发送报文的方法的模块或单元。
第十五方面，提供了一种发送报文的装置，该装置包括处理器和收发器，处理器用于执行程序，当处理器执行程序是，处理器和收发器实现第一方面或第一方面的任意一种可能的实现方式中的同步的方法。
可选的，该同步的装置还可以包括存储器，存储器用于存储处理器执行的程序。
该发送报文的装置的一种示例为RAN设备或UPF设备。
第十六方面，提供了一种发送报文的装置，该装置包括处理器和收发器，处理器用于执行程序，当处理器执行程序是，处理器和收发器实现第十二方面或第十二方面的任意一 种可能的实现方式中的发送报文的方法。
可选的，该发送报文的装置还可以包括存储器，存储器用于存储处理器执行的程序。
该发送报文的装置的一种示例为SMF设备。
第十七方面，提供一种计算机可读存储介质，该计算机可读存储介质存储用于发送报文的装置执行的程序代码，该程序代码包括用于实现第十一方面或第十一方面的任意一种可能的实现方式中的同步的方法的指令。
第十八方面，提供一种计算机可读存储介质，该计算机可读存储介质存储用于发送报文的装置执行的程序代码，该程序代码包括用于实现第十二方面或第十二方面的任意一种可能的实现方式中的同步的方法的指令。
第十九方面，提供一种芯片，该芯片包括处理器和通信接口，该通信接口用于与外部器件进行同行，该处理器用于实现第十一方面或第十一方面的任意一种可能的实现方式中的发送报文的方法。
可选地，该芯片还可以包括存储器，该存储器中存储有指令，处理器用于执行存储器中存储的指令，当该指令被执行时，处理器用于实现第十一方面或第十一方面的任意一种可能的实现方式中的发送报文的方法。
可选地，该芯片可以集成在RAN设备或UPF设备上。
第二十方面，提供一种芯片，该芯片包括处理器和通信接口，该通信接口用于与外部器件进行通信，该处理器用于实现第十二方面或第十二方面的任意一种可能的实现方式中的发送报文的方法。
可选地，该芯片还可以包括存储器，该存储器中存储有指令，处理器用于执行存储器中存储的指令，当该指令被执行时，处理器用于实现第十二方面或第十二方面的任意一种可能的实现方式中的发送报文的方法。
可选地，该芯片可以集成在SMF设备上。
附图说明
图1示出了应用本申请实施例的方法的网络架构的示意图。
图2示出了802.1AS中的一种时间同步的方法的原理图。
图3示出了应用本申请实施例的一种场景的示意图。
图4示出了应用本申请实施例的另一种场景的示意图。
图5示出了本申请实施例提供的一种同步的方法的示意性流程图。
图6示出了本申请实施例提供的一个具体的同步的方法的例子。
图7示出了本申请实施例提供的一个具体的同步的方法的例子。
图8示出了本申请实施例提供的一个具体的同步的方法的例子。
图9示出了本申请实施例提供的一个具体的同步的方法的例子。
图10示出了本申请实施例提供的一个具体的同步的方法的例子。
图11示出了另一种时间同步的方法的原理图。
图12示出了一种频率同步的方法的原理图。
图13示出了应用本申请实施例的一种场景的示意图。
图14示出了本申请实施例提供的一个具体的同步的方法的例子。
图15示出了本申请实施例提供的一个具体的同步的方法的例子。
图16示出了本申请实施例提供的一种识别时钟同步报文的例子。
图17示出了本申请实施例提供的一种通信装置的示意性框图。
图18示出了本申请实施例提供的另一种通信装置的示意性框图。
图19示出了本申请实施例提供的一种发送报文的方法的示意性流程图。
图20示出了本申请实施例提供的一种发送报文的方法的示意性流程图。
图21示出了本申请实施例提供的一种发送报文的例子。
图22示出了本申请实施例提供的一种发送报文的例子。
图23示出了本申请实施例提供的一种通信装置的示意性框图。
图24示出了本申请实施例提供的另一种通信装置的示意性框图。
具体实施方式
下面将结合附图，对本申请中的技术方案进行描述。
图1是应用本申请实施例的方法的网络架构100的示意图。下面对该网络架构100中涉及的各个部分分别进行说明。
1、终端设备110：可以包括各种具有无线通信功能的手持设备、车载设备、可穿戴设备、计算设备、物联网终端设备或连接到无线调制解调器的其它处理设备，以及各种形式的终端，移动台(mobile station，MS)，终端(terminal)，用户设备(user equipment，UE)，软终端等等。例如，水表、电表、传感器等。
2、(无线)接入网络(radio access network，(R)AN)网元120：用于为特定区域的授权终端设备提供入网功能，并能够根据终端设备的级别，业务的需求等使用不同质量的传输隧道。
(R)AN网元能够管理无线资源，为终端设备提供接入服务，进而完成控制信号和终端设备数据在终端设备和核心网之间的转发，(R)AN网元也可以理解为传统网络中的基站，包括但不限于eNodeB、WiFi AP、WiMAX BS等。
3、用户面网元130：用于分组路由和转发以及用户面数据的服务质量(quality of service，QoS)处理等，主要负责对用户报文进行处理，例如转发、计费等。
在5G通信***中，该用户面网元可以是用户面功能(user plane function，UPF)网元。在未来通信***中，用户面网元仍可以是UPF网元，或者，还可以有其它的名称，本申请不做限定。
4、数据网络140：用于为用户提供传输数据服务的运营商网络，如IP多媒体业务(IP multi-media service，IMS)，互联网(Internet)等。
在5G通信***中，该数据网络可以是数据网络(data network，DN)。在未来通信***中，数据网络仍可以是DN，或者，还可以有其它的名称，本申请不做限定。
5、接入管理网元150：主要用于移动性管理和接入管理等，可以用于实现移动性管理实体(mobility management entity，MME)功能中除会话管理之外的其它功能，例如，合法监听以及接入授权/鉴权、用户位置更新、用户注册网络、用户切换等功能。
在5G通信***中，该接入管理网元可以是接入和移动性管理功能(access and mobility management function，AMF)网元。在未来通信***中，接入管理网元仍可以是AMF网元， 或者，还可以有其它的名称，本申请不做限定。
6、会话管理网元160：主要用于会话管理，如会话建立、修改、释放等。具体功能如终端设备的网络互连协议(internet protocol，IP)地址分配和管理、选择可管理用户平面功能、策略控制和收费功能接口的终结点以及下行数据通知等。
在5G通信***中，该会话管理网元可以是会话管理功能(session management function，SMF)网元。在未来通信***中，会话管理网元仍可以是SMF网元，或者，还可以有其它的名称，本申请不做限定。
7、主时钟设备170：提供同步主时钟信号，使得移动通信***中的终端设备与该主时钟信号同步。
该主时钟设备170可以为TSN主时钟设备，具体的可以为可编程逻辑控制器(programmable logic controller，PLC)，本申请实施例对此不作限定。
可选的，图1所示的***架构100中还可以包括以下网元：
8、策略控制网元：用于指导网络行为的统一策略框架，为控制面功能网元(例如AMF，SMF网元等)提供策略规则信息等。
在4G通信***中，该策略控制网元可以是策略和计费规则功能(policy and charging rules function，PCRF)网元。在5G通信***中，该策略控制网元可以是策略控制功能(policy control function，PCF)网元。在未来通信***中，策略控制网元仍可以是PCF网元，或者，还可以有其它的名称，本申请不做限定。
9、数据管理网元：用于处理终端设备标识，接入鉴权，注册等。
在5G通信***中，该数据管理网元可以是统一数据管理(unified data management，UDM)网元。在未来通信***中，统一数据管理仍可以是UDM网元，或者，还可以有其它的名称，本申请不做限定。
可以理解的是，上述网元或者功能既可以是硬件设备中的网络元件，也可以是在专用硬件上运行软件功能，或者是平台(例如，云平台)上实例化的虚拟化功能。
进一步地，以将RAN网元简称为RAN，UPF网元简称为UPF，AMF网元简称为AMF，SMF网元简称为SMF。并且，本申请后续所描述的RAN均可替换为(R)AN)网元，UPF均可替换为用户面网元，AMF均可替换为接入管理网元，SMF均可替换为会话管理网元。
为方便说明，本申请，以装置为终端设备、RAN、UPF、AMF、SMF、TSN主时钟设备为例，对同步的方法进行说明，对于装置为终端设备内的芯片、RAN内的芯片、UPF内的芯片、AMF内的芯片、SMF内的芯片、TSN主时钟设备内的芯片的实现方法，可参考装置分别为终端设备、RAN、UPF、AMF、SMF、TSN的具体说明，不再重复介绍。
一种可能的实施例，在图1所示的移动网络中，可以采用TSN时钟同步机制对终端设备进行同步。
图2示出了802.1AS中的一种时间同步的方法的原理图。图2中包含4个时间感知***(time-aware system)，分别为主时钟(GrandMaster，GM)，(i-1)，i，(i+1)。其中，每个time-aware system分别包含主端口(master port)和从端口(slave port)。在802.1AS时间同步的原理中，每个中间time-aware system需要对修正域(correction filed，CF)进行修正，其中，CF即当前节点与主时钟之间的时间偏差，中间time-aware system即GM与待同步的time-aware system之间的节点。
Time-aware system之间可以采用两步(two-step)机制传输802.1AS报文，也可以采用一步(one-step)机制传输802.1AS报文。在two-step机制下，利用同步(SYNC，Synchronization)报文和跟随(follow-up)报文进行参数传递。在one-step机制下，利用SYNC报文进行参数传递。
下文将描述中间节点如何对CF进行修正，作为举例，以time-aware system(i+1)如何与GM之间进行时间同步进行描述。
201，GM在T0时刻发送SYNC报文#1。可选的，该SYNC报文#1携带T0，CF1，和频率比率ratio_GM。其中，CF1表示GM与上一跳节点的时间偏差，由于SYNC报文#1为GM发送的，没有上一跳节点，因此CF1＝0。其中，ratio_GM的值为1，可以理解为GM与GM的频率比率。
对应的，(i-1)的入端口，即slave端口接收SYNC报文#1。
202，(i-1)的出端口，即master端口发送SYNC报文#2。可选的，该SYNC报文#2携带T0，CF2，和GM与(i-1)的频率比率ratio_(i-1)。其中，CF2表示(i-1)与GM的时间偏差，具体如下：
CF2＝CF1+传输时间#1+驻留时间#1×ratio_(i-1)，时间单位为GM的时间单位。
其中，传输时间#1表示从GM出端口发出SYNC报文#1到(i-1)入端口接收SYNC报文#1的传输时延，传输时间#1的时间单位为GM的时间单位。驻留时间#1表示从(i-1)的入端口收到SYNC报文#1到出端口发送SYNC报文#2的处理时延，时间单位为(i-1)的时间单位。驻留时间#1×ratio_(i-1)则表示将驻留时间#1的时间单位换算为GM的时间单位。
对应的，(i)的入端口，即slave端口接收SYNC报文#2。
203，(i)的出端口，即master端口发送SYNC报文#3。可选的，该SYNC#3报文携带T0，CF3，和GM与(i)的频率比率ratio_(i)。其中，CF3表示(i)与GM的时间偏差，具体如下：
CF3＝(传输时间#2+驻留时间#2×ratio_NR)×ratio_(i-1)+CF2，时间单位为GM的时间单位。
其中，ratio_(i)＝ratio_(i-1)*ratio_NR，ratio_NR指的是(i-1)与(i)的频率比率，ratio_(i)的含义为GM与(i)的频率比率。
其中，传输时间#2表示从(i-1)出端口发出SYNC报文#2到(i)入端口接收SYNC报文#2的传输时延，传输时间#2的时间单位为(i-1)的时间单位。驻留时间#2表示从(i)的入端口收到SYNC报文#2到出端口发送SYNC报文#3的处理时延，时间单位为(i)的时间单位。驻留时间#2×ratio_NR则表示将驻留时间#2的时间单位换算为(i-1)的时间单位。(传输时间#2+驻留时间#2×ratio_NR)×ratio_(i-1)则表示将(传输时间#2+驻留时间#2×ratio_NR)的时间单位换算为GM的时间单位。
对应的，(i+1)的入端口，即slave端口接收SYNC报文#3，并根据SYNC报文#3进行同步。
(i+1)为待同步节点，(i+1)的入端口计算其与GM之间的时间偏差，记作CF4，具体如下：
CF4＝传输时间#3×ratio_(i)+CF3，时间单位为GM的时间单位。
其中，传输时间#3标识从(i)出端口到(i+1)入端口的传输时延，单位为(i)的时间单位。
(i+1)的入端口与GM同步后的时间为T0+CF4。
本申请实施例中，当在移动网络中采用TSN时钟同步机制对时间感知端点设备(time-aware end station)进行同步时，可以将移动网络中的网元(或者移动网络中的网元以及网元之间的链路)视为一个整体，可以称之为中继网络。此时中继网络可以从TSN主时钟设备接收时钟同步报文(比如SYNC报文)，并向端点设备发送时钟同步报文。这里，中继网络向端点设备发送的时钟同步报文包括修正域CF，使得端点设备可以根据该修正域CF与TSN主时钟设备进行同步。这里，端点设备即需要被同步的设备，例如工厂设备(比如传感器)。
图3示出了应用本申请实施例的一种场景的示意图。如图3所示，中继网络31中可以包括终端设备302、RAN 303和UPF 304。具体的，此时可以将移动网络中的终端设备302、RAN 303和UPF 304作为一个整体，即中继网络31，也可以称之为“时间感知中继(time-aware relay)31”，也就是说，将终端设备302、RAN 303和UPF 304整体作为一个桥(bridge)或者路由器(router)。此时，通过终端设备302、RAN 303和UPF 304，可以实现终端设备302与主时钟设备305的同步，或者实现与终端设备302连接的端点设备301与TSN主时钟设备305的同步。
图4示出了应用本申请实施例的另一种场景的示意图。如图4所示，中继网络41包括终端设备402和RAN 403。具体的，此时可以将移动网络中的终端设备402和RAN 403作为一个整体，即中继网络41，也可以称之为“时间感知中继(time-aware relay)41”，即将终端设备402和RAN 403整体作为一个桥(bridge)或者路由器(router)。此时，通过终端设备402和RAN 403，可以实现终端设备402与主时钟设备405的同步，或者实现与终端设备402连接的端点设备401与TSN主时钟设备405的同步。
需要说明的是，图3中所示的主时钟设备305、图4中所示的主时钟设备405，还可以是与主时钟设备进行了时钟同步的设备节点。本发明以主时钟设备为例进行说明，但对此并不做限定。
可选的，端点设备可以与中继网络中的终端设备合设，本申请实施例对此不作限定。
图5示出了本申请实施例提供的一种同步的方法的示意性流程图。该方法由中继网络中的第一网元执行。具体而言，当中继网络包括UPF、RAN和终端设备时，第一网元可以为UPF、RAN或终端设备。当中继网络包括RAN和终端设备时，第一网元可以为RAN或终端设备。
图5中所示的同步的方法包括步骤510至530。
510，所述第一网元接收时钟同步报文。
520，所述第一网元确定所述中继网络的第一时间，所述中继网络的第一时间包括所述RAN与所述终端设备之间传输所述时钟同步报文对应的第一下行传输时延。
530，所述第一网元确定所述中继网络的时间修正域，所述时间修正域包括所述第一下行传输时延。
因此，本申请实施例中，第一网元可以根据时钟同步报文，确定中继网络的时间修正域，该时间修正域包括RAN设备与终端设备之间传输该时钟同步报文对应的第一下行传 输时延，从而有助于实现在移动网络中采用TSN时钟同步机制对终端设备或端点设备进行其与外部时钟的时钟同步。
本申请实施例中，以时钟同步报文为SYNC报文为例进行描述。第一时间也可以称为驻留时间，表示从中继网络的入端口收到SYNC报文到出端口发送SYNC报文的处理时延。本申请实施例中，由于中继网络中至少包括RAN和终端设备，因此该第一时间至少包括RAN设备与终端设备之间传输该时钟同步报文的第一下行传输时延。
下面结合图3所示的场景，详细描述本申请实施例的同步的方法。
具体的，图3中，终端设备302与端点设备301之间的链路，以及UPF 304与TSN主时钟设备305之间的链路，为TSN链路。在TSN链路上，可以采用802.1AS时间同步原理进行参数传递，本申请实施例不对这部分链路做详细描述。
在图3所示的场景中，time-aware relay 31的入端口，即UPF 304的入端口；time-aware relay 31的出端口，即终端设备302的出端口。当time-aware relay 31的出端口向端点设备301发送SYNC报文时，需要携带修正域CF。其中，修正域CF包括time-aware relay 31处理SYNC报文对应的驻留时间，以及time-aware relay 31与发送SYNC报文的节点之间的传输时延。
如图3所示，CF＝驻留时间+N6时延(delay_N6_link)。其中，N6时延即为发送时钟同步报文的节点设备(即TSN主时钟设备305)与中继网络31(即UPF 304的入端口)之间的下行传输时延，本申请实施例可以称之为第二下行传输时延。
本申请实施例中，假设time-aware relay 31中的终端设备与UPF之间没有进行时间同步。其中，驻留时间包括RAN与终端设备之间的空口时延(delay_Uu_DL)和N3时延(delay_N3_link)。具体而言，delay_Uu_DL具体可以为RAN与终端设备之间传输SYNC报文对应的第一下行传输时延，delay_N3_link具体可以为UPF与RAN之间的下行传输时延，本申请实施例可以称之为第三下行传输时延。
本申请实施例中，中继网络31中的UPF 304、RAN 303或终端设备302分别可以进行时间域修正，即确定修正域CF。其中，中继网络31的出端口，即终端设备302的出端口，需要修正的链路Link如下：
Link＝relay_link+N6_link＝Uu_link+N3_link+N6_link，
其中，relay_link表示中继网络31对应的链路，即包括终端设备302的出端口与RAN 303的入端口之间的Uu链路(Uu_link)，和UPF 304的入端口与RAN 302的入端口之间的N3链路(N3_link)，N6_link表示TSN主时钟设备305的出端口与UPF 304的入端口之间的链路。
这里，可以假设UPF 304本地时间与RAN 303本地时间(即空口时间)的频率比率为ratio1，TSN主时钟与UPF 304本地时间的频率比率为ratio2。
下面分别描述UPF 304、RAN 303或终端设备302进行时间域修正的具体方案。
一、UPF进行时间域修正
图6示出了本申请实施例提供的一个具体的同步的方法的例子。应理解，图6示出了同步的方法的步骤或操作，但这些步骤或操作仅是示例，本申请实施例还可以执行其他操作或者图6中的各个操作的变形。此外，图6中的各个步骤可以按照与图6呈现的不同的顺序来执行，并且有可能并非要执行图6中的全部操作。图6中与图3中相同的附图标记 表示相同或相似的含义，为了简洁，此处不再赘述。
601，TSN时钟向中继网络31的入端口，即UPF入端口发送SYNC报文。作为举例，TSN时钟发送时间为t1。
一个可选的实施例，TSN时钟可以确定N6时延(delay_N6_link)，并向中继网络31发送该delay_N6_link。一种可能的实现方式，当采用one-step机制时，该SYNC报文中携带t1，ratio2，以及delay_N6_link。或者，另一种可能的实现方式，当采用two-step机制时，t1，ratio2，以及delay_N6_link携带在紧随SYNC报文之后的跟随(follow_up)报文中。
一个可选的实施例，可以由中继网络31(比如中继网络31中的中的网元UPF)测量delay_N6_link。具体的，UPF测量delay_N6_link可以参见现有技术的描述，这里不再详细描述。
本申请实施例中，TSN时钟可以被替换为其他时钟设备，例如GrandMaster，本申请实施例对此不作具体限定。
602，中继网络31的入端口，即UPF入端口接收TSN时钟发送的SYNC报文，触发UPF确定中继网络的驻留时间。
本申请实施例中，SYNC报文可以用于触发UPF确定中继网络的驻留时间。具体的，当UPF识别接收到的报文为SYNC报文之后，可以触发UPF确定中继网络的驻留时间。具体的，UPF可以根据配置在UPF上的策略信息，或者根据从SMF接收到的策略信息，识别接收到的报文是否为SYNC报文。
需要说明的是，策略信息指的是识别SYNC报文的策略，比如源地址、目的地址等信息。例如，当UPF确定接收到的报文的源地址或目的地址与策略信息一致时，可以确定该报文为SYNC报文。应注意，本申请实施例中，还可以称策略信息为其他名称，比如转发规则，或会话管理信息等，本申请实施例对此不作限定。
例如，策略信息可以为目的MAC地址01-80-C2-00-00-0E，当UPF确定接收到的报文的MAC地址为01-80-C2-00-00-0E时，RAN判断该报文为SYNC报文。
本申请实施例中，当UPF识别SYNC报文之后，可以触发UPF与UE之间的下行(downlink)QoS监测(monitoring)，以确定中继网络的驻留时间。
QoS监测(monitoring)具体可以包括步骤603至609。
603，UPF向RAN发送N3 DL PDU。
具体的，UPF通过N3用户面路径向RAN发送SYNC报文，该SYNC报文即为602中从TSN时钟接收到的SYNC报文。这里，UPF需要对该SYNC报文封装GTP-U头(header)，封装GTP-U头后的报文即为N3 DL PDU。
本申请实施例中，UPF还可以向RAN发送第一指示信息，该第一指示信息用于指示RAN设备获取下行空口时延，即第一下行传输时延。换言之，该第一指示信息用于指示RAN触发下行空口时延的测量。一种可能的实现方式中，该第一指示信息可以与SYNC报文一起发送给RAN，比如将第一指示信息携带在GTP-U header中，本申请实施例对此不作限定。
可选的，本申请实施例中，第一指示信息包括第一服务质量(quality of service，QoS)流标识(QoS flow ID，QFI)。此时，所述第一指示信息用于指示所述RAN设备接收到 所述第一QFI对应的报文时，获取所述第一下行传输时延。
这里，第一QFI即特殊QFI，即，第一QFI对应的QoS流报文为时钟同步报文，例如SYNC报文。也就是说，当RAN接收到的报文中包括第一QFI时，RAN可以识别出该报文为SYNC报文，然后可以触发第一下行传输时延的测量。
对应的，RAN从UPF接收N3 DL PDU。RAN收到UPF发送的N3 DL PDU之后，根据第一指示信息触发下行空口时延测量。此时，RAN记录接收SYNC报文对应的空口时间air_t1。
604，RAN通过空口向终端设备发送DL PDU，该DL PDU中包括SYNC报文。
605，终端接收到SYNC报文之后，向RAN返回确认(acknowledge，ACK)。其中，ACK中携带终端设备接收SYNC报文对应的空口时间air_t2。
需要说明的是，本申请实施例中，网元接收SYNC报文，包括该网元对SYNC报文进行处理，如经过该网元上的各个协议层对SYNC报文进行处理。相应的，网元接收SYNC报文对应的空口时间即为该网元对该SYNC报文处理之后的时间。这里，网元例如为终端设备、RAN、UPF等。因此，本申请描述的终端设备302的出端口，也可以理解为是终端设备302的入端口；终端设备302的入端口接收SYNC报文对应的空口时间，可以理解为终端设备302对SYNC报文进行处理之后的时间。
606，当RAN接收到终端设备返回的ACK时，确定下行传输成功。此时，RAN确定下行空口时延delay_Uu_DL，其中，
delay_Uu_DL＝air_t2-air_t1，时间单位为空口时间单位。
607，RAN向UPF发送N3报文。其中，N3报文包括下行空口时延delay_Uu_DL。
对应的，UPF接收该N3报文，并获取下行空口时延delay_Uu_DL。
608，UPF获取N3时延。
一种可能的实现方式中，UPF可以通过GTP-U回应请求(echo request)、GTP-U回应响应(echo Response)测量N3时延(delay_N3_link)。
具体的，UPF在时间Ta向RAN发送GTP-U echo request；RAN在时间Tb接收该GTP-U echo request。RAN在时间Tc向UPF发送GTP-U echo response；UPF在时间Td接收该GTP-U echo response。那么，则有：
delay_N3_link＝[(Td-Ta)-(Tc-Tb)]/2。
当RAN与UPF之间存在频率偏差时，假设UPF本地时钟与RAN本地时钟的频率比率为ratio1，则delay_N3_link＝[(Td-Ta)-(Tc-Tb)*ratio1]/2。此时，delay_N3_link的时间单位为UPF本地时间单位。
609，UPF确定中继网络的驻留时间(delay_relay)，也可以称为中继网络的下行传输时延。其中，delay_relay如下：
delay_relay＝delay_Uu_DL+delay_N3_link；
当RAN与UPF之间存在频率偏差时，假设UPF本地时钟与RAN本地时钟的频率比率为ratio1，则将delay_relay换算为UPF本地时间单位，则有：
delay_relay＝delay_Uu_DL×ratio1+delay_N3_link。
进一步地，假设TSN时钟与UPF本地时钟的频率比率为ratio2，则将delay_relay换算成TSN时间单位为：
delay_relay＝(delay_Uu_DL×ratio1+delay_N3_link)×ratio2。
610，UPF确定时间修正域CF。
具体的，UPF根据中继网络的驻留时间(delay_relay)，以及UPF与TSN时钟之间的传输时延，即N6时延(delay_N6_link)，确定时间修正域CF，时间单位TSN时间单位。其中，CF如下：
CF＝delay_relay+delay_N6_link。
611，UPF将时间修正域CF发送给RAN。
612，RAN将时间修正域CF发送给终端设备。
具体的，步骤611中UPF可以将时间修正域携带在follow_up报文中发送给RAN。可以理解，该follow_up报文即为紧随603中的SYNC报文的follow_up报文。然后在步骤612中RAN通过空口将该follow_up报文转发给终端设备。
需要说明的是，步骤611中UPF还可以通过其它报文将CF发送给RAN，本申请实施例不做限定。
之后，终端设备可以根据接收到的CF与TSN时钟进行时钟同步。进一步的，终端设备可以与端点设备进行时钟同步。具体的，终端设备与端点设备之间的同步过程可以参考802.1AS机制，这里不再详细说明。
因此，本申请实施例中，将终端设备、RAN和UPF作为一个中继网络，并由该中继网络中的UPF确定该中继网络传输SYNC报文的“内部时延”，即从UPF接收SYNC报文，到终端设备接收SYNC报文的时间，实现终端设备(或者与该终端设备连接的TSN端点设备)与TSN时钟源的时间同步。
二、RAN进行时间域修正
图7示出了本申请实施例提供的一个具体的同步的方法的例子。应理解，图7示出了同步的方法的步骤或操作，但这些步骤或操作仅是示例，本申请实施例还可以执行其他操作或者图7中的各个操作的变形。此外，图7中的各个步骤可以按照与图7呈现的不同的顺序来执行，并且有可能并非要执行图7中的全部操作。图7中与图3中相同的附图标记表示相同或相似的含义，为了简洁，此处不再赘述。
701，TSN时钟向中继网络31的入端口，即UPF入端口发送SYNC报文。
具体的，701可以参见601中的描述，为避免重复，这里不再赘述。
702，UPF入端口接收TSN时钟发送的SYNC报文，UPF出端口向RAN入端口发送SYNC报文。
作为一个可选的实施例，当UPF测量delay_N6_link时，向RAN发送该delay_N6_link。
703，RAN的入端口接收到SYNC报文，触发RAN确定中继网络的驻留时间。
本申请实施例中，SYNC报文可以用于触发RAN确定中继网络的驻留时间。具体的，当RAN识别接收到的报文为SYNC报文之后，可以触发RAN确定中继网络的驻留时间。
一个可选的实施例，RAN可以根据配置在RAN上的策略信息，或者根据从SMF接收到的策略信息，识别接收到的报文是否为SYNC报文。当识别到报文为SYNC报文之后，可以获取第一下行传输时延和第三下行传输时延。具体的，策略信息可以参见上文中的描述，为了简洁，这里不再赘述。
例如，策略信息可以为目的MAC地址01-80-C2-00-00-0E，当RAN确定接收到的报 文的MAC地址为01-80-C2-00-00-0E时，RAN判断该报文为SYNC报文。
一个可选的的实施例，RAN可以接收第二指示信息，第二指示信息用于指示RAN获取中继网络的驻留时间，然后RAN根据第二指示信息，获取第一下行传输时延和第三下行传输时延。
一种可能的实现方式中，第二指示信息可以与SYNC报文一起发送给RAN，比如将第二指示信息携带在GTP-U header中，本申请实施例对此不作限定。
可选的，本申请实施例中，第二指示信息包括第二服务质量(quality of service，QoS)流标识(QoS flow ID，QFI)。此时，所述第二指示信息用于指示所述RAN设备接收到所述第二QFI对应的报文时，获取所述中继网络的驻留时间。
一种具体的实现方式中，第二QFI对应的QoS流报文为时钟同步报文，即SYNC报文。也就是说，当RAN接收到的报文中包括第二QFI时，RAN可以识别出该报文为SYNC报文，然后可以触发获取中继网络的驻留时间。
本申请实施例中，当RAN识别SYNC报文之后，可以触发确定UPF与终端设备之间的下行传输时延。具体可以包括步骤704至708。
此时，RAN记录接收SYNC报文对应的空口时间air_t1。
704，RAN向终端设备发送DL PDU。
具体的，RAN通过空口向终端设备发送DL PDU，该DL PDU中包括SYNC报文。
705，终端接收到SYNC报文之后，向RAN返回确认(acknowledge，ACK)。其中，ACK中携带终端设备接收SYNC报文对应的空口时间air_t2。
706，当RAN接收到终端设备返回的ACK时，确定下行传输成功。此时，RAN确定下行空口时延delay_Uu_DL，其中，
delay_Uu_DL＝air_t2-air_t1，delay_Uu_DL的时间单位为空口时间单位。
707，RAN获取N3时延。
一种可能的实现方式中，RAN可以通过GTP-U回应请求(echo request)、GTP-U回应响应(echo Response)测量N3时延(delay_N3_link)。
具体的，RAN在时间Ta向RAN发送GTP-U echo request；UPF在时间Tb接收该GTP-U echo request。UPF在时间Tc向UPF发送GTP-U echo response；RAN在时间Td接收该GTP-U echo response。那么，则有：
delay_N3_link＝[(Td-Ta)-(Tc-Tb)]/2。
当RAN与UPF之间存在频率偏差时，假设UPF本地时钟与RAN本地时钟的频率比率为ratio1，则delay_N3_link＝[(Td-Ta)-(Tc-Tb)*ratio1]/2。此时，delay_N3_link的时间单位为UPF本地时间单位。
708，RAN确定中继网络的驻留时间(delay_relay)。具体的，delay_relay如下：
delay_relay＝delay_Uu_DL×ratio1+delay_N3_link，对应UPF本地时间单位。
709，RAN确定时间修正域CF。CF如下：
CF＝delay_relay*ratio2+delay_N6_link。
其中，假设TSN时钟与UPF本地时钟的频率比率为ratio2。CF的时间单位为TSN时间单位。
具体的，RAN确定时间修正域的方式与UPF确定时间修正域的方式相类似，可以参 见610中的描述，这里不再赘述。
710，RAN将时间修正域CF发送给终端设备。
具体的，步骤710中RAN可以将时间修正域携带在follow_up报文中，并通过空口发送给UE。可以理解，该follow_up报文即为紧随704中的SYNC报文的follow_up报文。需要说明的是，步骤710中RAN还可以通过其它报文将CF发送给UE，本申请实施例对此不做限定。
之后，终端设备可以根据接收到的CF与TSN时钟进行时钟同步。进一步的，终端设备可以与端点设备进行时钟同步。具体的，终端设备与端点设备之间的同步过程可以参考802.1AS机制，这里不再详细说明。
因此，本申请实施例中，将终端设备、RAN和UPF作为一个中继网络，并由该中继网络中的RAN确定该中继网络传输SYNC报文的“内部时延”，即从UPF接收SYNC报文，到终端设备接收SYNC报文的时间，实现终端设备(或者与该终端设备连接的TSN端点设备)与TSN时钟源的时间同步。
三、终端设备进行时间域修正
图8示出了本申请实施例提供的一个具体的同步的方法的例子。应理解，图8示出了同步的方法的步骤或操作，但这些步骤或操作仅是示例，本申请实施例还可以执行其他操作或者图8中的各个操作的变形。此外，图8中的各个步骤可以按照与图8呈现的不同的顺序来执行，并且有可能并非要执行图8中的全部操作。图8中与图3中相同的附图标记表示相同或相似的含义，为了简洁，此处不再赘述。
801，TSN时钟向中继网络31的入端口，即UPF入端口发送SYNC报文。
具体的，801可以参见601中的描述，为避免重复，这里不再赘述。
802，UPF的入端口接收TSN时钟发送的SYNC报文，UPF出端口向RAN入端口发送SYNC报文。
作为一个可选的实施例，当UPF测量delay_N6_link时，向RAN发送该delay_N6_link。
803，RAN的入端口接收到TSN时钟发送的SYNC报文，RAN出端口向终端设备入端口发送SYNC报文。此时，RAN记录接收SYNC报文对应的空口时间air_t1，并将该空口时间air_t1发送给终端设备。
这里，RAN还可以向终端设备发送ratio1。
804，终端设备接收SYNC报文，触发终端设备确定中继网络的驻留时间。此时，终端设备记录接收该SYNC报文对应的空口时间air_t2。
本申请实施例中，SYNC报文可以用于触发终端设备确定中继网络的驻留时间。具体的，当终端设备识别接收到的报文为SYNC报文之后，可以触发终端设备确定中继网络的驻留时间。具体的，终端设备可以根据配置在该终端设备上的策略信息，或者根据从SMF接收到的策略信息，识别接收到的报文是否为SYNC报文。具体的，策略信息可以参见上文中的描述，为了简洁，这里不再赘述。
例如，策略信息可以为目的MAC地址01-80-C2-00-00-0E，当终端设备确定接收到的报文的目的MAC地址为01-80-C2-00-00-0E时，RAN判断该报文为SYNC报文。
一个可选的的实施例，终端设备可以接收第三指示信息，第三指示信息用于指示终端设备获取中继网络的驻留时间。
可选的，本申请实施例中，第三指示信息包括第三服务质量(quality of service，QoS)流标识(QoS flow ID，QFI)。此时，所述第三指示信息用于指示所述终端设备设备接收到所述第三QFI对应的报文时，获取所述中继网络的驻留时间。
一种具体的实现方式中，在会话建立过程中，终端设备保存无线承载与QFI的对应关系。终端设备根据无线承载与QFI的对应关系，确定接收的报文对应第三QFI时，可以识别出该报文为SYNC报文，然后触发获取中继网络的驻留时间。
一个可选的实施例，终端设备通过无线承载(即空口连接)接收报文，则可以根据无线承载于QFI的对应关系，确定报文对应的QFI。当该QFI为第三QFI时，终端设备可以识别该报文为SYNC报文。
805，终端设备确定空口时延delay_Uu_DL，如下：
delay_Uu_DL＝air_t2-air_t1，
空口时延delay_Uu_DL的时间单位为空口时间单位。
可选的，终端设备将delay_Uu_DL转换为UPF本地时间为：
delay_Uu_DL＝(air_t2-air_t1)×ratio1。
806，UPF或RAN通过GTP-U echo request、GTP-U echo response机制确定N3链路时延(delay_N3_link)。需要说明的是，本申请实施例对于确定N3链路时延的测量时机不作限定，也就是说，806可以发生在805之前，或者发生在805之后，或者与805同时发生，都在本申请实施例的保护范围之内。
下面以UPF确定delay_N3_link为例进行说明。
1)、UPF在N3_t1时刻发送GTP-U echo request；
2)、RAN在N3_t2时刻接收GTP-U echo request，并在N3_t3时刻发送GTP-U echo response。这里，GTP-U echo response携带N3_t2、N3_t3，或者携带(N3_t3-N3_t2)，即N3_t3与N3_t2的差值。
3)、UPF在N3_t4时刻接收GTP-U echo response。
4)、UPF计算delay_N3_link。
其中，N3_t1、N3_t4对应的是UPF本地时间，N3_t2、N3_t3对应的是RAN本地时间。
将Delay_N3_Link换算到UPF本地时间为：
Delay_N3_Link＝[(N3_t4-N3_t1)-(N3_t3-N3_t2)×ratio1]/2
807，RAN将N3时延发送给终端设备。
当由RAN确定N3时延时，由RAN将N3时延发送给终端设备，具体的，RAN可以通过follow_up消息，或者上述SYNC消息将N3时延发送给终端设备。当由上述SYNC消息将N3时延发送给终端设备，步骤807可以与步骤803合并。
807’，UPF经由RAN将N3时延发送给终端设备。
当由UPF确定N3时延时，由UPF将N3时延发送给终端设备，具体的，UPF可以通过follow_up消息，或者上述SYNC消息将N3时延发送给终端设备。当由上述SYNC消息将N3时延发送给终端设备，步骤807’可以与步骤802合并。
808，终端设备确定中继网络的驻留时间(delay_relay)。具体的，delay_relay如下：
delay_relay＝delay_Uu_DL×ratio1+delay_N3_link，时间单位为UPF本地时间。
809，终端设备确定修正域CF。CF如下：
CF＝delay_relay*ratio2+delay_N6_link。
其中，CF的时间单位为TSN时间单位。
之后，终端设备可以根据CF与TSN时钟进行时钟同步。进一步的，终端设备可以与端点设备进行时钟同步。具体的，终端设备与端点设备之间的同步过程可以参考802.1AS机制，这里不再详细说明。
因此，本申请实施例中，将终端设备、RAN和UPF作为一个中继网络，并由该中继网络中的终端设备确定该中继网络传输SYNC报文的“内部时延”，即从UPF接收SYNC报文，到终端设备接收SYNC报文的时间，实现终端设备(或者与该终端设备连接的TSN端点设备)与TSN时钟源的时间同步。
需要说明的是，本申请中涉及到的实施例，在确定修正域时，涉及到分段时延确定、以及时间单位换算。其中，分段时延确定、与时间单位换算均以相同执行点执行的。例如，UPF获取到分段时延、并进行单位换算；RAN获取到各个分段时延、并进行单位换算；UE获取到各个分段时延、并进行单位换算。但是，还有其它实现方式，即分段时延、时间单位换算由不同的执行点执行。例如，RAN将空口时间换算为UPF本地时间并发送至UPF、UPF获取已换算好的空口时延。这些具体实现方式与本申请实施例的发明思路一致，不再一一赘述。
下面结合图4所示的场景，详细描述本申请实施例的同步的方法。
具体的，图4中，终端设备402与端点设备401之间的链路，以及RAN403与TSN主时钟设备405之间的链路，为TSN链路。在TSN链路上，可以采用802.1AS时间同步原理进行参数传递，本申请实施例不对这部分链路做详细描述。
在图4所示的场景中，time-aware relay 41的入端口，即RAN 403的入端口；time-aware relay 41的出端口，即终端设备402的出端口。当time-aware relay 41的出端口向端点设备401发送SYNC报文时，需要调整时间修正域CF。
如图4所示，CF＝驻留时间+N6*时延(delay_N6*_link)。其中，N6*时延即为发送时钟同步报文的节点设备(即TSN主时钟设备305)与中继网络(即RAN 403的入端口)之间的下行传输时延，本申请实施例可以称之为第二下行传输时延。
本申请实施例中，驻留时间即为RAN设备与终端设备之间的空口时延(delay_Uu_DL)。具体而言，delay_Uu_DL具体可以为RAN设备与终端设备之间传输SYNC报文的第一下行传输时延。
本申请实施例中，中继网络41中的RAN 403或终端设备402可以进行时间域修正。此时，中继网络41的出端口，即终端设备402的出端口，需要修正的链路Link如下：
Link＝relay_link+N6*_link＝Uu_link+N6*_link，
其中，relay_link表示中继网络41中的链路，即包括终端设备402的出端口与RAN 403的入端口之间的Uu链路(Uu_link)，N6*_link表示TSN主时钟设备405的出端口与RAN 403的入端口之间的链路。
这里，可以假设TSN主时钟与RAN 403本地时间的频率比率为ratio。
下面分别描述RAN 403或终端设备402进行时间域修正的具体方案。
一、RAN进行时间域修正
图9示出了本申请实施例提供的一个具体的同步的方法的例子。应理解，图9示出了同步的方法的步骤或操作，但这些步骤或操作仅是示例，本申请实施例还可以执行其他操作或者图9中的各个操作的变形。此外，图9中的各个步骤可以按照与图9呈现的不同的顺序来执行，并且有可能并非要执行图9中的全部操作。图9中与图4中相同的附图标记表示相同或相似的含义，为了简洁，此处不再赘述。
901，TSN时钟向中继网络41的入端口，即RAN入端口发送SYNC报文。作为举例，TSN时钟发送时间为t1。
一个可选的实施例，TSN时钟可以确定N6时延(delay_N6*_link)，并向中继网络41发送该delay_N6*_link。一种可能的实现方式，当采用one-step机制时，该SYNC报文中携带t1，ratio，以及delay_N6*_link。或者，另一种可能的实现方式，当采用two-step机制时，t1，ratio，以及delay_N6*_link携带在紧随SYNC报文之后的跟随(follow_up)报文中。
一个可选的实施例，可以由中继网络41(比如中继网络41中的RAN)测量delay_N6*_link。具体的，RAN测量delay_N6*_link可以参见现有技术的描述，这里不再详细描述。
902，RAN入端口接收TSN时钟发送的SYNC报文，触发RAN确定中继网络的驻留时间。此时，RAN记录接收SYNC报文对应的空口时间air_t1。
本申请实施例中，SYNC报文可以用于触发RAN确定中继网络的驻留时间。具体的，当RAN识别接收到的报文为SYNC报文之后，可以触发RAN确定中继网络的驻留时间。
一个可选的实施例，RAN可以根据配置在RAN上的策略信息，或者根据从SMF接收到的策略信息，识别接收到的报文是否为SYNC报文。当识别到报文为SYNC报文之后，可以获取第一下行传输时延和第三下行传输时延。具体的，策略信息可以参见上文中的描述，为了简洁，这里不再赘述。
例如，策略信息可以为目的MAC地址01-80-C2-00-00-0E，当RAN确定接收到的报文的目的MAC地址为01-80-C2-00-00-0E时，RAN判断该报文为SYNC报文。
作为一个可选的实施例，RAN还可以测量delay_N6*_link。
903，RAN向终端设备发送SYNC报文。
具体的，RAN通过空口向终端设备发送SYNC报文，该SYNC报文外层封装SDAP header、PDCP header。
904，终端接收到SYNC报文之后，向RAN返回确认(acknowledge，ACK)。其中，ACK中携带终端设备接收SYNC报文对应的空口时间air_t2。
905，当RAN接收到终端设备返回的ACK时，确定下行传输成功。此时，RAN确定下行空口时延delay_Uu_DL，其中，
delay_Uu_DL＝air_t2-air_t1，delay_Uu_DL时间单位为空口时间单位。
RAN将delay_Uu_DL换算为TSN时间单位，则有：
delay_Uu_DL＝(air_t2-air_t1)×ratio。
906，RAN确定中继网络的驻留时间(delay_relay)。具体的，delay_relay如下：
delay_relay＝delay_Uu_DL，即中继网络的驻留时间delay_relay等于下行空口时延delay_Uu_DL。
907，RAN确定时间修正域CF。CF如下：
CF＝delay_relay+delay_N6*_link＝(air_t2-air_t1)×ratio+delay_N6*_link，其中，CF的时间单位为TSN时间单位。
908，RAN将时间修正域CF发送给终端设备。
具体的，步骤908中RAN可以将时间修正域携带在follow_up报文中，并通过空口发送给终端设备。可以理解，该follow_up报文即为紧随903中的SYNC报文的follow_up报文。
之后，终端设备可以根据接收到的CF与TSN时钟进行时钟同步。进一步的，终端设备可以与端点设备进行时钟同步。具体的，终端设备与端点设备之间的同步过程可以参考802.1AS机制，这里不再详细说明。需要说明的是，步骤908中RAN还可以通过其它报文将CF发送给终端设备，本发明不做限定。
因此，本申请实施例中，将终端设备和RAN作为一个中继网络，并由该中继网络中的RAN确定该中继网络传输SYNC报文的“内部时延”，即从RAN接收SYNC报文，到终端设备接收SYNC报文的时间，实现终端设备(或者与该终端设备连接的TSN端点设备)与TSN时钟源的时间同步。
二、终端设备进行时间域修正
图10示出了本申请实施例提供的一个具体的同步的方法的例子。应理解，图10示出了同步的方法的步骤或操作，但这些步骤或操作仅是示例，本申请实施例还可以执行其他操作或者图10中的各个操作的变形。此外，图10中的各个步骤可以按照与图10呈现的不同的顺序来执行，并且有可能并非要执行图10中的全部操作。图10中与图4中相同的附图标记表示相同或相似的含义，为了简洁，此处不再赘述。
1001，TSN时钟向中继网络41的入端口，即RAN入端口发送SYNC报文。
具体的，1001可以参见901中的描述，为避免重复，这里不再赘述。
1002，RAN的入端口接收TSN时钟发送的SYNC报文，RAN出端口向终端设备的入端口发送SYNC报文。具体的，RAN通过空口向终端设备发送SYNC报文，该SYNC报文外层封装SDAP header、PDCP header。
作为一个可选的实施例，当RAN测量delay_N6*_link时，向终端设备发送delay_N6*_link。
此时，RAN记录接收SYNC报文对应的空口时间air_t1，并将该空口时间air_t1发送给终端设备。
可选的，RAN还可以向终端设备发送ratio。
1003，终端设备接收SYNC报文，触发终端设备确定中继网络的驻留时间。此时，终端设备记录接收该SYNC报文对应的空口时间air_t2。
本申请实施例中，SYNC报文可以用于触发终端设备确定中继网络的驻留时间。具体的，终端设备识别SYNC报文的方式可以参见图8中804的描述，为了简洁，这里不再赘述。
1004，终端设备确定空口时延delay_Uu_DL，如下：
delay_Uu_DL＝air_t2-air_t1，
空口时延delay_Uu_DL的时间单位为空口时间单位。
终端设备将delay_Uu_DL转换为TSN时间，则有：
delay_Uu_DL＝(air_t2-air_t1)×ratio。
1005，终端设备确定中继网络的驻留时间(delay_relay)。具体的，delay_relay如下：
delay_relay＝delay_Uu_DL，即中继网络的驻留时间delay_relay等于下行空口时延delay_Uu_DL。
1006，终端设备确定修正域CF。CF如下：
CF＝delay_relay+delay_N6*_link＝(air_t2-air_t1)×ratio+delay_N6*_link，其中，CF的时间单位为TSN时间单位。
之后，终端设备可以根据CF与TSN时钟进行时钟同步。进一步的，终端设备可以与端点设备进行时钟同步。具体的，终端设备与端点设备之间的同步过程可以参考802.1AS机制，这里不再详细说明。
因此，本申请实施例中，将终端设备和RAN作为一个中继网络，并由该中继网络中的终端设备确定该中继网络传输SYNC报文的“内部时延”，即从RAN接收SYNC报文，到终端设备接收SYNC报文的时间，实现终端设备(或者与该终端设备连接的TSN端点设备)与TSN时钟源的时间同步。
一种可能的实施例，在图1所示的移动网络中，可以采用端到端(end to end,E2E)时钟同步机制实现全网同步。
具体而言，E2E时钟同步包括时间同步和频率同步。时间同步，指的是按照接收到的时间来调控设备内部的时间；频率同步，指的是信号之间的频率或相位上保持某种严格的特定关系，其相对应的有效瞬间以同一平均速率出现，以维持通信网络中所有的设备以相同的速率运行，即信号之间保持恒定的相位差。
在一种具体的实现方式中，可以通过在消息中打上时间戳来标记消息的收、发时刻，并通过时延测量机制来实现主从设备之间的路径时延测量。从时钟(slave)利用获取到的时间戳和路径时延参数，计算主从时间的偏移(offset)，从而控制从时钟同步到主时钟(master)。
根据1588时钟同步报文协议可知，当通过E2E时钟同步机制实现全网同步时，涉及到的消息可以包括SYNC报文、延迟请求(delay_req)、延迟响应(delay_resp)。具体的，首先主时钟选择与协商算法得出全网时钟同步的树形拓扑以及grandmaster时钟，然后从grandmaster时钟开始，向相邻节点(slave)发送1588同步报文，每个slave参照master进行时钟同步后，自己会以master的身份向邻居交互1588协议报文，计算出主从时钟间的offset及频率偏差，完成本地时钟的对时，以此类推全网进行时钟同步。
图11示出了802.1AS中的另一种时间同步的方法的原理图。具体的，master与slave之间的交互过程如下：
1，master在t1时刻发送SYNC报文，并将t1时间戳携带在该SYNC报文中。
2，slave在t2时刻接收到SYNC报文，在本地产生t2时间戳。并且，slave从接收到的SYNC报文中获取t1时间戳。
3，slave在t3时刻发送延时请求(delay_req)报文，并在本地产生t3时间戳。
4，maser在t4时刻接收到delay_req报文，并在本地产生t4时间戳，然后将t4时间戳携带在延时响应(delay_resp)报文中，回传给slave。
5，slave接收到delay_resp报文，从报文中提取t4时间戳。
本申请实施例中，可以将master到slave的发送路径时延表示为delayms，将slave到master的发送路径时延表示为delaysm，将slave和master之间的时间偏差表示为offset。显然，delayms、delaysm以及offset均为未知，且满足以下等式：
t2-t1＝delaysm+offset                        (1)；
t4-t3＝delayms-offset                         (2)；
(t2-t1)–(t4-t3)＝(delaysm+offset)–(delayms-offset)        (3)；
offset＝[(t2-t1)-(t4-t3)-(delaysm-delayms)]/2           (4)；
显然，如果delaysm＝delayms，即master和slave之间的收发链路延时对称，那么：
offset＝[(t2-t1)-(t4-t3)]/2                    (5)；
这样slave就可以根据t1，t2，t3，t4四个时间戳计算出自己和master之间的时间偏差offset，调整自身的时间以达到和master同步。
从图11中可以看出，该时钟同步的方法是建立在master和slave之间的收发链路时延对称的基础上，即802.1AS协议在计算路径偏差offset时，假设delaysm＝delayms。而在固网中，相邻两个节点间有线直连，路径时延相差不超过微妙(μs)，因此此时1588v2协议的精度能够达到μs级。
图12示出了802.1AS中的一种频率同步的方法的原理图。具体而言，master周期性地给slave发送SYNC报文。具体的，master与slave之间的交互过程如下：
1，master在t5时刻发送SYNC报文。
一种实现方式中，可以将t5时间戳携带在该SYNC报文对应的follow_up报文中。另一种实现方式中，可以将t5时间戳携带在该SYNC报文中。
2，slave在t6时刻接收到SYNC报文，在本地产生t6时间戳。并且，slave从接收到的follow_up报文或SYNC报文中获取t5时间戳。
3，master在t7时刻发送SYNC报文。
一种实现方式中，可以将t7时间戳携带在该SYNC报文对应的follow_up报文中。另一种实现方式中，可以将t7时间戳携带在该SYNC报文中。
4，slave在t8时刻接收到SYNC报文，在本地产生t8时间戳。并且，slave从接收到的follow_up报文或SYNC报文中获取t7时间戳。
假设链路时延不变，则：
如果t8-t6＝t7-t5，则slave的频率和master的频率是同步的；
如果t8-t6>t7-t5，则slave的频率比master的频率快，需要调慢slave的频率；
如果t8-t6<t7-t5，则slave的频率比master的频率慢，需要调快slave的频率。
具体的，主设备和从设备的频率比率neighborRateRatio可以表示为以下公式：
Figure PCTCN2019105142-appb-000001
图11以及图12所示的时钟同步方案依赖于收、发链路对称。而在移动网络中，上行链路、下行链路并不对称。因此，如果要在移动网络中采用TSN时钟同步机制，则需要多上下行链路传输时延进行补偿。具体而言，移动网络中的链路时延包括空口时延，而在空口时延上收发链路(即上下行链路)时延不对称，这不符合E2E时间同步机制的要求。
有鉴于此，本申请实施例提供了一种时钟同步的方法，通过对空口链路上的不对称的时延进行补偿，模拟出上下行链路对称的空口时延，进而基于图11和图12中的时钟同步原理进行时钟同步。下面，将具体描述如何进行上下行链路时延补偿的技术方案。
图13示出了应用本申请实施例的一种场景的示意图。如图13所示，终端设备可以采用E2E机制与TSN时钟源进行时钟同步，然后终端设备利用802.1AS与端点设备进行时钟同步。具体的，UPF与终端设备之间的链路时延包括两段，分别为空口时延和N3时延。其中，空口时延中收发链路不对称，因此本申请实施例中需要对该收发链路进行补偿。
对于时间同步的实施例而言，可以将移动网络的下行传输时延与上行传输时延的差值记为D，如下所示：
D＝delaysm-delayms                        (7)
结合上文中的等式(4)，可以得到：
2*delaysm+D＝(t2-pt1)+(t4-t3)
2*delaysm＝(t2-t1)+(t4-t3)–D
＝(t2-t1)+t4-(t3+D)，
记作tx＝(t3+D)，则
2*delaysm＝(t2-t1)+t4-tx                      (8)
因此，本申请实施例中，可以将上下行传输时延差值补偿到时间戳t3中，即master发送delay_resp的时间信息中。
此时，slave计算时间偏差offset的公式变为：
Offset＝t2-t1–delaysm                      (9)
具体而言，在图13所示的场景中，delaysm、delayms如下：
delaysm＝delay(UPF to RAN)+delay(RAN to UE)
delayms＝delay(UE to RAN)+delay(RAN to UPF)
当RAN与UPF之间的上行链路和下行链路为对称链路时，即：
delay(UPF to RAN)＝delay(RAN to UPF)。
那么，空口的下行、上行时延差D可以表示为：
D＝delaysm-delayms＝delay(RAN to UE)-delay(UE to RAN)。
当RAN与UPF之间的上行链路和下行链路为不对称链路时，假设delay(UPF to RAN)与delay(RAN to UPF)的差值为经验值delay_N3，那么D可以表示为：
D＝delaysm-delayms＝delay(RAN to UE)-delay(UE to RAN)+delay_N3。
对于频率同步的实施例而言，在移动网络中的链路时延为动态变化的情况下，有：
t6-t5＝delaysm_1                        (10)
t8-t7＝delaysm_2                        (11)
本申请实施例中，可以记X＝delaysm_1-delaysm_2，再根据上面两个公式(10)和(11)，可以得到：
t8-t7＝delaysm_1-X，
即t8-(t7-X)＝delaysm_1，即tx＝t7-X。
是将链路动态时延差值补偿到时间戳中(即t7，master发送SYNC的时刻)。
此时，slave计算频率同步的公式变为：
Figure PCTCN2019105142-appb-000002
因此，本申请实施例中，可以将链路动态时延差值补偿到时间戳t7中，即master发送SYNC报文的时间信息中。
具体而言，在图13所示的场景中，delaysm_1、delaysm_2如下：
delaysm_1＝delay(UPF to RAN)_1+delay(RAN to UE)_1
delaysm_2＝delay(UPF to RAN)_2+delay(RAN to UE)_2
当RAN与UPF之间的链路为固定链路时，即链路时延固定。即：
delay(UPF to RAN)_1＝delay(UPF to RAN)_2。
那么，X＝delaysm_1-delaysm_2＝delay(RAN to UE)_1-delay(RAN to UE)_2。
当RAN与UPF之间的链路为非固定链路时，假设其UPF与RAN之间的相邻两次时延偏差为经验值delay_N3’。那么，
X＝delaysm_1-delaysm_2＝delay(RAN to UE)_1-delay(RAN to UE)_2+delay_N3’。
因此，本申请实施例通过对空口时延上的上下行链路时延进行补偿，使得补偿之后的上下行链路时延对称，进而终端设备能够通过E2E机制实现与TSN时钟的同步，然后终端设备再利用802.1AS与端点设备进行同步，实现终端设备(或者与该终端设备连接的TSN端点设备)与TSN时钟源的同步。
需要说明的是，本申请实施例均以RAN与UPF之间的链路上下行对称，和/或链路为固定链路为例进行说明的。
图14示出了本申请实施例提供的一个具体的同步的方法的例子。应理解，图14示出了同步的方法的步骤或操作，但这些步骤或操作仅是示例，本申请实施例还可以执行其他操作或者图14中的各个操作的变形。此外，图14中的各个步骤可以按照与图14呈现的不同的顺序来执行，并且有可能并非要执行图14中的全部操作。图14中与图13中相同的附图标记表示相同或相似的含义，为了简洁，此处不再赘述。
1401，UPF向RAN发送SYNC报文。作为举例，UPF在t1时刻向RAN发送该SYNC报文，其中，t1为TSN时间。
可选的，该SYNC报文中可以携带t1，N6时延(delay_N6_link)，以及TSN时钟与UPF本地时钟的频率比率ratio1。具体的，UPF向RAN发送SYNC报文的方式可以参考601中的描述，为了简洁，这里不再赘述。
1402，RAN接收SYNC报文，触发确定空口的上下行时延补偿D。
这里，空口的上下行时延补偿D为空口下行时延(delay(RAN to UE))与空口上行时延(delay(UE to RAN))之差。
本申请实施例中，SYNC报文可以用于触发确定空口的上下行时延补偿。具体的，当RAN识别到接收的报文为SYNC报文之后，可以触发确定空口的上下行时延补偿，具体的可以包括步骤1403至1411。
具体的，RAN识别SYNC报文的方式可以参考上文步骤703中的描述，为了简洁，这里不再赘述。
此时，RAN记录接收SYNC报文对应的空口时间air_t1。
1403，RAN通过空口向终端设备发送SYNC报文。
1404，终端设备通过空口向RAN返回接收该SYNC报文的空口时间air_t2。
1405，RAN确定下行空口时延delay(RAN to UE)。
具体的，1403至1405可以参见704至706中的描述，为了简洁，这里不再赘述。
1406，终端设备接收到SYNC报文后，向RAN发送delay_req报文，对应的发送时间为air_t3。
具体的，该delay_req报文外层可以封装SDAP header，PDCP header。
一种实现方式中，air_t3、air_t2可以携带在该步骤1406中发送至RAN的报文中。具体的，air_t3、air_t2可以携带在该delay_Req报文中，或者携带在该delay_Req报文的外层封装头中，本申请实施例对此不作限定。
对应的，RAN接收该delay_req报文。具体的，RAN接收该delay_req报文的时间为air_t4。
1407，RAN接收终端设备发的delay_req报文之后，通过N3用户面连接向UPF发送delay_req报文。
对应的，UPF接收该delay_req报文，对应的接收时间为t4。
1408，RAN确定delay(UE to RAN)。
具体的，RAN根据air_t3,air_t4，确定上行空口时延delay(UE to RAN)＝air_t4-air_t3。
1409，UPF通过N3用户面连接向RAN发送delay_resp报文，该delay_resp报文携带时间t4。
1410，RAN接收delay_Resp报文，并确定tx，其中tx＝t4+D。
具体的，RAN根据delay_resp报文中的t4，以及之前确定的下行空口时延delay(RAN to UE)和上行空口时延delay(UE to RAN)，确定tx。这里可以将delay(RAN to UE)表示为delay_Uu_DL，将上行空口时延delay(UE to RAN)表示为delay_Uu_UL。此时tx如下：
tx＝t4+(delay_Uu_DL-delay_Uu_UL)。
1411，RAN向终端设备发送delay_resp报文，携带tx。
应注意，当TSN时间与RAN时间之间的频率比率为ratio时，要先将(delay_Uu_DL-delay_Uu_UL)换算成TSN时间单位，此时tx如下：
tx＝t4+(delay_Uu_DL-delay_Uu_UL)×ratio。
本申请实施例中，delay_req报文、delay_resp报文均为为精密时钟协议(precision time protocol，PTP)报文。一种可能的实现方式中，当RAN收到上行报文或下行报文时，RAN可以识别接收到的报文是否为PTP报文。之后，RAN可以根据识别到的报文的类型，进行相应的操作。
1412，终端设备根据tx，确定offset。具体的，offset如下：
2*offset＝(t2-t1)-(tx-t3)
本申请另外一种可选的实施例中，可以由UPF对tx进行修改。具体的，此时RAN可以将delay(RAN to UE)、delay(UE to RAN)发送至UPF。或者，RAN将delay(RAN to UE)与delay(UE to RAN)之差(即delay_Uu_DL-delay_Uu_UL)发送给UPF。例如通过步骤1407将上述参数发送至UPF。然后，UPF可以根据t4，以及下行空口时延delay(RAN to UE)和上行空口时延delay(UE to RAN)推导tx，或者根据t4以及 delay_Uu_DL-delay_Uu_UL推导tx。最后，UPF通过RAN向终端设备发送delay_resp，携带tx。
因此，本申请实施例中，通过RAN或UPF对空口链路的上下行时延进行补偿，使得终端设备能够通过E2E机制实现与TSN时钟的时间同步，然后终端设备再利用802.1AS与端点设备进行时间同步，实现终端设备(或者与该终端设备连接的TSN端点设备)与TSN时钟源的时间同步。
图15示出了本申请实施例提供的一个具体的同步的方法的例子。应理解，图15示出了同步的方法的步骤或操作，但这些步骤或操作仅是示例，本申请实施例还可以执行其他操作或者图15中的各个操作的变形。此外，图15中的各个步骤可以按照与图15呈现的不同的顺序来执行，并且有可能并非要执行图15中的全部操作。图15中与图13中相同的附图标记表示相同或相似的含义，为了简洁，此处不再赘述。
1501，UPF向RAN发送SYNC报文。作为举例，UPF在t5时刻向RAN发送该SYNC报文，其中，t5为TSN时间。
可选的，该SYNC报文中可以携带t5。当SYNC报文不携带t5时，UPF紧随该SYNC报文之后向RAN发送follow_up报文。
1502，RAN接收SYNC报文，触发下行空口时延测量。
本申请实施例中，SYNC报文可以用于触发确定下行空口时延测量。具体的，当RAN识别到接收的报文为SYNC报文之后，可以触发确定下行空口时延测量，具体的可以包括步骤1503至1505。
具体的，RAN识别SYNC报文的方式可以参考上文中步骤703的描述，为了简洁，这里不再赘述。
此时，RAN记录接收SYNC报文对应的空口时间air_t1。
1503，RAN通过空口向终端设备发送SYNC报文。
对应的，终端设备接收该SYNC报文，接收时刻为t6，为终端设备本地时间。
1504，终端设备通过空口向RAN返回接收该SYNC报文的空口时间air_t2。
1505，RAN确定delay(RAN to UE)_1，delay(RAN to UE)_1如下：
delay(RAN to UE)_1＝air_t2-air_t1。
具体的，1503至1505可以参见704至706中的描述，为了简洁，这里不再赘述。
可选的，UPF在执行1501之后，执行1506，即向RAN发送对应于1501中的SYNC报文的follow_up报文，其中可以包括时间信息t5。RAN接收到该follow_up报文之后，将该follow_up报文发送给终端设备。
1507，UPF向RAN发送SYNC报文。作为举例，UPF在t7时刻向RAN发送该SYNC报文，其中，t7为TSN时间。
可选的，该SYNC报文中可以携带t7。当SYNC报文不携带t7时，UPF紧随该SYNC报文之后向RAN发送follow_up报文。
1508，RAN接收SYNC报文，触发下行空口时延测量。
此时，RAN记录接收SYNC报文对应的空口时间air_t3。
1509，RAN通过空口向终端设备发送SYNC报文。
对应的，终端设备接收该SYNC报文，接收时刻为t8，为终端设备本地时间。
1510，终端设备通过空口向RAN返回接收该SYNC报文的空口时间air_t4。
1511，RAN确定delay(RAN to UE)_2，delay(RAN to UE)_2如下：
delay(RAN to UE)_2＝air_t4-air_t3。
可选的，UPF在执行1507之后，执行1512，即向RAN发送对应于1507中的SYNC报文的follow_up报文，其中可以包括时间信息t7。
具体的，1507至1512可以参见1501至1506中的描述，为了简洁，这里不再赘述。
1513，RAN确定tx，其中，tx＝t7-X。其中，X＝delay(RAN to UE)_1-delay(RAN to UE)_2。
具体的，RAN根据获取到的t7，以及记录的delay(RAN to UE)_1、delay(RAN to UE)_2，推导tx，tx如下：
tx＝t7-[delay(RAN to UE)_1-delay(RAN to UE)_2]。
1514，RAN向终端设备发送follow_up报文，其中携带tx。
1515，终端设备根据tx，确定频率比率neighborRateRatio。具体的，neighborRateRatio如下：
Figure PCTCN2019105142-appb-000003
因此，本申请实施例中，通过RAN或UPF对空口链路的上下行时延进行补偿，使得终端设备能够通过E2E机制实现与TSN时钟的频率同步，然后终端设备再利用802.1AS与端点设备进行频率同步，实现终端设备(或者与该终端设备连接的TSN端点设备)与TSN时钟源的同步。
图16示出了本申请实施例提供的一种识别时钟同步报文的例子。应理解，图16示出了识别报文的方法的步骤或操作，但这些步骤或操作仅是示例，本申请实施例还可以执行其他操作或者图16中的各个操作的变形。此外，图16中的各个步骤可以按照与图16呈现的不同的顺序来执行，并且有可能并非要执行图16中的全部操作。
1601，终端设备通过RAN、AMF向SMF发送会话建立请求。其中，该会话建立请求中可以包括数据网络名称(data network name,DNN)，单网络切片选择辅助信息(single network slice selection assistance information，S-NSSAI)等信息。
可选的，终端设备可以向SMF发送第四指示信息，第四指示信息用于指示终端设备需要与TSN时钟同步。
1602，SMF确定终端设备需要与TSN时钟同步，则分配特殊QFI供时钟同步报文使用，即该特殊QFI对应的QoS流报文为时钟同步报文。这里，特殊QFI例如可以为前文中所述的第一QFI，时钟同步报文例如为PTP报文，或者802.1AS报文。
具体的，SMF可以根据以下至少一项判断终端设备是否需要与TSN时钟同步：
-1601中的第四指示信息，或
-签约信息，或
-DNN/S-NSSAI。
例如，当步骤1601中携带了第四指示信息且签约允许时，SMF分配特殊QFI供时钟同步报文使用。又例如，当SMF确定终端设备访问的DNN需要与TSN时钟源进行时钟同步时，SMF分配特殊QFI供时钟同步报文使用。又例如，当SMF确定终端设备访问的 切片(即S-NSSAI)需要与TSN时钟源进行时钟同步时，SMF分配特殊QFI供时钟同步报文使用。
1603，SMF向UPF发送N4会话建立请求。其中，该N4会话建立请求中携带转发规则，该转发规则用于指示UPF对时钟同步报文(比如PTP报文，或802.1AS报文)添加该特殊QFI。
这里，该转发规则例如可以为上文中的策略信息，比如源地址、目的地址等信息。例如，当UPF确定收到的报文的源地址或目的地址与转发规则中的地址信息一致时，可以确定该报文为时钟同步报文，然后UPF可以在该报文中的报文头中添加该特殊的QFI，该特殊的QFI进一步可以用于向RAN指示该报文为时钟同步报文。
1604，UPF返回N4会话建立响应。其中，该N4会话建立响应携带UPF隧道信息(tunnel info)。
1605，SMF通过AMF向RAN发送N2会话请求。其中，N2会话请求中携带N2会话管理信息(N2 SM info)和N1会话管理信息(N1 SM info)。其中，N2 SM info中包括特殊QFI和UPF隧道信息。N1 SM info中包括特殊QFI、报文过滤器(packet filter)。
1606，RAN触发与终端设备之间的无线资源控制(radio resource control，RRC)连接建立过程。在该过程中，RAN将1102中获取的N1 SM info发送至终端设备。
其中，RAN和终端设备保存QFI与无线承载之间的对应关系。
1607，会话建立的其他过程。例如RAN通过AMF向SMF返回N4会话响应，其中携带AN tunnel info。又例如SMF触发与UPF之间的N4会话修改等步骤。
1608，RAN判断接收到的报文是否为时钟同步报文。本申请实施例中，时钟同步报文包括下行时钟同步报文，比如SYNC报文。
对于DL传输而言
-UPF发送时钟同步报文时，UPF根据转发规则，判断该报文为时钟同步报文，则为该报文外层封装特殊QFI，然后发送至RAN；
-RAN接收DL报文，根据DL报文头中的特殊QFI判断DL报文为时钟同步报文，然后触发相应操作，如下行空口时延测量、N3传输时延测量、空口上下行时延补偿等。RAN向终端设备发送DL报文。
-终端设备接收DL报文，根据接收的无线承载、保存的无线承载与QFI的对应关系，识别接收到的报文对应的为特殊QFI，从而进一步判断接收到的报文为时钟同步报文，从而进行相应处理，如记录接收时钟同步报文对应的空口时间。
可选的，时钟同步报文包括上行时钟同步报文，比如delay_req等。
对于UL传输而言
-终端设备发送时钟同步报文时，为该报文封装特殊QFI并发送至RAN；或，终端设备通过特殊QFI对应的无线承载将该报文发送至RAN。
-RAN根据UL报文头中的QFI，或者，RAN根据无线承载与QFI的对应关系，确定UL报文是时钟同步报文，然后触发相应的操作，如确定下行空口时延、上行空口时延等。RAN将处理后的UL报文发送至UPF。
-UPF接收UL报文，进行相应处理，如记录接收UL报文对应的时刻。
需要说明的是，本申请中描述的是网元如何识别时钟同步报文。但需要知道的是，识 别接收到的报文为时钟同步报文不是最终目的，最终目的是触发相应操作，如N3传输时延确定、空口传输时延确定、空口上下行时延补偿等。因此，上述描述也可以描述为如何触发网元执行相应操作，如确定N3传输时延、空口传输时延等。
本申请实施例中，SMF还可以通过其他方式为时钟同步报文分配特殊QFI，本申请实施例对此不作限定。另外，QFI还可以是其它参数，如新定义的信元indicator，该指示表明报文为时钟同步报文，本申请实施例对此不作限定。
因此，本申请实施例中，SMF可以根据终端设备的指示信息，或签约信息，或DNN/S-NSSAI等，为时钟同步报文分配特殊QFI，并且SMF可以向UPF、RAN以及终端设备发送该QFI，向UPF和终端设备下发转发规则，使得UPF可以对时钟同步报文封装该特殊的QFI，或者终端设备在该特殊QFI对应的无线信道上传输时钟同步报文，进而实现RAN可以根据该特殊的QFI，或者根据传输报文的无线信道来识别时钟同步报文。
802.1AS协议中，支持以多播方式传输时钟同步报文。802.1AS报文中包含域信息(domain)，表明终端设备(或TSN end station)与domain所表示的时钟域进行时间同步。本申请实施例中，UPF收到多播报文(如SYNC报文)，可以根据终端设备(或TSN end station)对应的时钟域，确定需要同步的终端设备(或TSN end station)，即UPF根据终端设备(或TSN end station)对应的时钟域，确定将802.1AS报文发往哪些终端设备。
本申请实施例中，UPF可以通过以下步骤1至3获取终端设备(或TSN end station)对应的时钟域：
步骤1、SMF获取终端设备(或TSN end station)对应的时钟域。具体的，SMF可以通用以下方式获取终端设备(或TSN end station)对应的时钟域：
在会话建立过程中，终端设备将终端设备标识(UE ID)和domain ID发送至SMF。或，
在会话建立过程中，SMF从UDM获取UE ID与domain ID的对应关系。或，
在会话建立过程中，SMF从获取UE ID与domain ID的对应关系。或，
在会话建立过程中，SMF从DN-AAA获取UE ID与domain ID的对应关系。或
在会话建立过程中，SMF从AMF接收UE ID与domain ID的对应关系。
其中，AMF可以通过如下方式获取到UE ID与domain ID的对应关系：
在注册流程中，终端设备将终端设备标识(UE ID)和domain ID发送至AMF。或
在注册流程中，AMF从UDM获取UE ID与domain ID的对应关系。或，
在注册流程中，AMF从PCF获取UE ID与domain ID的对应关系。或，
步骤2，SMF将该终端设备对应的时钟域发送至UPF，即SMF将终端设备与时钟域的对应关系发送至UPF。其中，终端设备可以用UE ID标识，如SUPI，UE IP，UE MAC；时钟域，用domain ID标识。
需要说明的是，上面所述的UE ID还可以是TSN end station ID，如APP ID，本申请实施例对此不作限定。
步骤3，UPF获取到UE ID与domain ID的对应关系。
具体的，当UPF接收到802.1AS报文时，可以根据802.1AS报文头中的domain ID、以及UE ID与domain ID的对应关系，确定待同步的UE ID。然后，UPF通过本申请实施例的所述同步方法，实现终端设备与时钟域的时间同步。
上述主要从不同设备之间交互的角度对本申请实施例提供的同步的方法的方案进行了介绍。可以理解的是，UPF、RAN或终端设备为了实现上述功能，其包含了执行各个功能相应的硬件结构和/或软件模块。结合本申请中所公开的实施例描述的各示例的单元及算法步骤，本申请实施例能够以硬件或硬件和计算机软件的结合形式来实现。某个功能究竟以硬件还是计算机软件驱动硬件的方式来执行，取决于技术方案的特定应用和设计约束条件。本领域技术人员可以对每个特定的应用来使用不同的方法来实现所描述的功能，但是这种实现不应认为超出本申请实施例的技术方案的范围。
本申请实施例可以根据上述方法示例对UPF、RAN和终端设备等进行功能单元的划分，例如，可以对应各个功能划分各个功能单元，也可以将两个或两个以上的功能集成在一个处理单元中。上述集成的单元既可以采用硬件的形式实现，也可以采用软件功能单元的形式实现。需要说明的是，本申请实施例中对单元的划分是示意性的，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式。
在采用集成的单元的情况下，图17示出了本申请实施例中所涉及的一种通信装置的一种可能的示例性框图，该装置1700可以以软件、硬件或软硬结合的形式存在。图17示出了本申请实施例中所涉及的装置的一种可能的示意性框图。装置1700包括：处理单元1702和通信单元1703。处理单元1702用于对装置的动作进行控制管理。通信单元1703用于支持装置与其他设备的通信。装置还可以包括存储单元1701，用于存储装置的程序代码和数据。
图17所示的装置1700可以是本申请实施例所涉及的UPF、RAN或终端设备。
当图17所示的装置1700为UPF时，处理单元1702能够支持装置1700执行上述各方法示例中由UPF完成的动作，例如，处理单元1702支持装置1700执行图6中的609，和/或用于本文所描述的技术的其它过程。通信单元1703能够支持装置1700与RAN等之间的通信，例如，通信单元1703支持装置1700执行图6中的步骤601、603、607、608、611，图7中的步骤701、702、707，图8中的801、802、806，图14中的1401、1407、1409，图15中的1501、1507，和/或其他相关的通信过程。
当图17所示的装置1700为RAN时，处理单元1702能够支持装置1700执行上述各方法示例中由RAN完成的动作，例如，处理单元1702支持装置1700执行图6中的606，图7中的706,708,709，图9中的906,907，图14中的1405,1408,1410，图15中的1505,1511,1510，和/或用于本文所描述的技术的其它过程。通信单元1703能够支持装置1700与UPF和终端设备等之间的通信，例如，通信单元1703支持装置1700执行图6中的步骤603至605、611、612，图7中的步骤702、704、705、707、710，图8中的802、803、806至807，图9中的901、903、905、908，图10中的1001、1002，图14中的1401、1403、1404、1406、1407、1409、1411，图15中的1501、1503、1509、1512，和/或其他相关的通信过程。
当图17所示的装置1700为终端设备时，处理单元1702能够支持装置1700执行上述各方法示例中由终端设备完成的动作，例如，处理单元1702支持装置1700执行图8中的804,805,808，图10中的1004至1006，图14中的1412，图15中的1515，和/或用于本文所描述的技术的其它过程。通信单元1703能够支持装置1700与RAN或端点设备等之间的通信，例如，通信单元1703支持装置1700执行图6中的步骤604至605、612，图7 中的步骤704、705、710，图8中的803、807，图9中的903、905、908，图10中的1002，图14中的1403、1404、1406、1411，图15中的1503、1509、1514，和/或其他相关的通信过程。
示例性地，处理单元1702可以是处理器或控制器，例如可以是中央处理器(Central Processing Unit，CPU)，通用处理器，数字信号处理器(Digital Signal Processor，DSP)，专用集成电路(Application-Specific Integrated Circuit，ASIC)，现场可编程门阵列(Field Programmable Gate Array，FPGA)或者其他可编程逻辑器件、晶体管逻辑器件、硬件部件或者其任意组合。其可以实现或执行结合本申请公开内容所描述的各种示例性的逻辑方框，单元和电路。所述处理器也可以是实现计算功能的组合，例如包含一个或多个微处理器组合，DSP和微处理器的组合等等。通信单元1703可以是通信接口，该通信接口是统称，在具体实现中，该通信接口可以包括一个或多个接口。存储单元1701可以是存储器。
当处理单元1702为处理器，通信单元1703为通信接口，存储单元1701为存储器时，本申请实施例所涉及的装置1700可以为图18所示的通信装置1800。
参阅图18所示，该装置1800包括：处理器1802和通信接口1803。进一步地，该装置1800还可以包括存储器1801。可选的，装置1800还可以包括总线1804。其中，通信接口1803、处理器1802以及存储器1801可以通过总线1804相互连接；总线1804可以是外设部件互连标准(Peripheral Component Interconnect，PCI)总线或扩展工业标准结构(Extended Industry Standard Architecture，EISA)总线等。所述总线1804可以分为地址总线、数据总线、控制总线等。为便于表示，图18中仅用一条粗线表示，但并不表示仅有一根总线或一种类型的总线。
其中，处理器1802可以通过运行或执行存储在存储器1801内的程序，执行所述装置1800的各种功能。
示例性地，图18所示的通信装置1800可以是本申请实施例所涉及的UPF、RAN或终端设备。
当装置1800为UPF时，处理器1802可以通过运行或执行存储在存储器1801内的程序，执行上述各方法示例中由UPF完成的动作。当装置1800为RAN时，处理器1802可以通过运行或执行存储在存储器1801内的程序，执行上述各方法示例中由RAN完成的动作。当装置1800为终端设备时，处理器1802可以通过运行或执行存储在存储器1801内的程序，执行上述各方法示例中由终端设备完成的动作。
时间感知***可以划分为两类：时间感知端点设备(time-aware end station)和时间感知中继(time-aware relay)。time-aware end station例如为图3中的端点设备301，图4中的端点设备401，或者图13中的端点设备1301。time-aware relay例如为图3中的中继网络31(即time-aware relay 31)、图4中的中继网络41(即time-aware relay 41)等，本申请实施例对此不作限定。
一个时间感知***可以支持多个时钟域。具体而言，一个TSN网络可以有多个时钟域，例如domain 0和domain 1，其中，不同的时钟域连接不同的时钟源。不同时钟源的时间起点不一样，或者时间间隔不一样。另外，一个TSN网络中的TSN bridge(比如time-aware relay)和TSN end station(比如time-aware end station)可以同时属于不同的时钟域。
其中，时间感知端点设备即TSN网络中时间同步的起点或终点。当一个时间感知端点设备不是主时钟(即时钟源)时，其为时间同步的终点，用于接收时间信息。当一个时间感知端点设备为主时钟时，其为时间同步的起点，用于发送时间信息。
在进行时间同步时，主时钟向所有直连的时间感知***发送时钟同步消息，该时钟同步消息中包含当前时间。每一个接收到该时钟同步消息的时间感知***对时间进行修正，补偿传输时延、处理时延。当该时间感知***是时间感知中继时，时间感知中继将修正的时延发送至所有直连的其它时间感知***。具体的，对时间进行修正可以参见上文中的描述。
由此可知，802.1AS协议中支持以多播方式传输时钟同步报文。时钟同步消息可以为SYNC消息、delay_req消息、pdelay_req消息、pdelay_resp消息、或follow_up消息等，本申请实施例对此不作限定。时钟同步消息的报文头中包括domain number字段，该字段用于指示发送时间信息的时钟所属的时钟域。本申请实施例中，还可以将报文中的domain number字段称为域标识(domain ID)字段。
图19示出了本申请实施例提供一种发送报文的方法，能够使得移动网络支持多播报文的传递。图19所示的方法包括1910至1930。其中，通信网元为移动网络中的网元，例如UPF或RAN。
1910，通信网元接收第一报文。其中，该第一报文包括域标识，域标识用于标识发送所述第一报文的节点设备所属的时钟域。
1920，所述通信网元根据域标识与用户面连接标识的对应关系，以及所述第一报文中的域标识，确定所述第一报文对应的用户面连接。
1930，所述通信网元通过所述第一报文对应的用户面连接向终端设备发送所述第一报文。
因此，本申请实施例中，移动网络中的通信网元可以根据域标识(domain ID)和用户面连接标识的对应关系，以及第一报文中的域标识，确定第一报文对应的用户面连接，然后通过该用户面连接向终端设备发送该第一报文，其中第一报文为多播报文。因此，本申请实施例能够实现移动网络中的通信网元对多播报文的发送。
可选的，所述通信网元接收来自SMF的所述域标识与用户面连接标识的对应关系。
图20示出了本申请实施例提供一种发送报文的方法，能够使得移动网络支持多播报文的传递。图20所示的方法包括2010和2020。其中，通信网元为移动网络中的网元，例如UPF或RAN。
2010，SMF确定域标识和用户面连接标识的对应关系，所述域标识用于标识发送第一报文的节点设备所属的时钟域。
2020，SMF将所述域标识和用户面连接标识的对应关系发送至通信网元，其中，所述对应关系用于所述通信网元确定向终端设备发送所述第一报文的用户面连接。
因此，本申请实施例中，SMF将域标识和用户面连接的对应关系发送给通信网元，使得通信网元能够根据该对应关系，确定用于发送第一报文的用户面连接，然后通过该用户面连接向终端设备发送该第一报文，其中第一报文为多播报文。因此，本申请实施例能够实现移动网络中的通信网元对多播报文的发送。
可选的，所述SMF确定域标识和用户面连接标识的对应关系，包括：
所述SMF获取终端设备标识和用户面连接标识的对应关系；
所述SMF获取终端设备标识和域标识的对应关系，其中，所述域标识用于标识所述终端设备对应的时钟域；
所述SMF根据终端设备标识和用户面连接标识的对应关系，以及，终端设备标识和域标识的对应关系，确定域标识和用户面连接标识的对应关系。
可选的，所述SMF确定域标识和用户面连接标识的对应关系，包括：
所述SMF获取所述终端设备的用户面连接标识以及网络标识的对应关系，其中，所述网络标识用于标识所述终端设备接入的网络；
所述SMF获取网络标识和域标识的对应关系，所述域标识用于标识所述终端设备对应的时钟域；
所述SMF根据所述用户面连接标识以及网络标识的对应关系，以及，网络标识和域标识的对应关系，确定域标识和用户面连接标识的对应关系。
可选的，所述网络标识包括以下至少一种：数据网络名称DNN、单网络切片选择辅助信息S-NSSAI。
可选的，本申请实施例中，所述第一报文为时钟同步报文。
可选的，本申请实施例中，所述用户面连接标识包括以下至少一种：会话标识、用户面隧道信息。
图21示出了本申请实施例提供的一种发送报文的例子，本申请实施例中，UPF根据域标识(domain ID)和用户面连接标识的对应关系，以及第一报文中的域标识，确定第一报文对应的用户面连接，然后通过该用户面连接向终端设备发送该第一报文。作为举例，本申请实施例可以用于上文图3中的场景。
应理解，图21示出了发送报文的方法的步骤或操作，但这些步骤或操作仅是示例，本申请实施例还可以执行其他操作或者图21中的各个操作的变形。此外，图21中的各个步骤可以按照与图21呈现的不同的顺序来执行，并且有可能并非要执行图21中的全部操作。
2101，终端设备通过RAN向AMF发送NAS消息，该NAS消息中携带会话标识(session ID)、DNN、S-NSSAI、会话建立请求等。
可选的，NAS消息中还可以携带终端设备标识和domain ID的对应关系。这里，终端设备标识可以为终端设备的媒体访问控制(media access control address,MAC)地址、用户永久标识(subscription permanent identifier，SUPI)、通用公共用户标识(generic public subscription identifier，GPSI)或互联网协议(internet protocol，IP)地址等，本申请实施例对此不作限定。
2102，AMF向SMF发送创建会话管理上下文请求消息。其中，创建会话管理上下文请求消息中携带终端设备的SUPI和步骤2101中的参数。
可选的，当NAS消息中携带终端设备标识和domain ID的对应关系时，创建会话管理上下文请求消息中还携带终端设备标识和domain ID的对应关系。
2103，SMF根据创建会话管理上下文请求消息，获取终端设备标识和会话标识的对应关系。
可选的，这里SMF还可以根据创建会话管理上下文请求，获取所述终端设备的会话 标识以及网络标识的对应关系。本申请实施例中，网络标识例如为以下中的至少一种：数据网络名称DNN、单网络切片选择辅助信息S-NSSAI等，或者其他的用于标识终端设备接入的网络的标识，本申请实施例对此不作限定。
可选的，SMF还可以将获取的上述对应关系进行保存。
可选的，本申请实施例中，当SMF确定该终端设备需要做时钟同步时，可以分配特殊QFI供时钟同步报文使用，即该特殊QFI对应的QoS流报文为时钟同步报文。此时，SMF可以保存session ID、特殊QFI的对应关系。
2104，SMF确定domain ID和会话标识的对应关系。
具体的，一种实现方式，SMF可以根据终端设备标识和会话标识的对应关系，以及终端设备标识和域标识的对应关系，确定域标识和会话标识的对应关系。
可选的，SMF可以获取创建会话管理上下文请求消息中携带的终端设备标识和domain ID的对应关系。
可选的，SMF还可以从UDM中获取终端设备标识和domain ID的对应关系，或者SMF可以从DN-AAA中获取终端设备标识和domain ID的对应关系。
例如，终端设备通过session1访问网络，SMF保存了终端设备MAC和session1的对应关系。SMF可以从UDM获取到终端设备MAC和domain1的对应关系，因此，SMF可以确定session1和domain1的对应关系。如下表1和表2所示：
表1
Figure PCTCN2019105142-appb-000004
表2
Figure PCTCN2019105142-appb-000005
可选的，上述举例中终端设备可以满足以下限定条件：一个终端设备MAC只能访问一个domain，且一个终端设备只能建立一个session。
另一种实现方式，SMF可以根据用会话标识以及网络标识的对应关系，以及，网络标识和域标识的对应关系，确定域标识和会话标识的对应关系。
具体的，SMF可以通过如下方式获取网络标识和域标识的对应关系：(1)SMF上配置网络标识与domain ID的对应关系，或者(2)SMF从UDM获取网络标识和domain ID的对应关系。进一步的，SMF获取到终端设备标识、网络标识和domain ID三者之间的对应关系。然后，SMF根据步骤2103中保存的会话标识以及网络标识的对应关系，确定域标识和会话标识的对应关系。
例如，终端设备建立了3个会话，分别为session1、session2和session3，分别通过这三个会话访问DNN1、DNN2和DNN3。另外，DNN1对应domain1，DNN2对应domain2，DNN3对应domain3。会话建立过程中，SMF保存了DNN和会话标识的对应关系，如表3所示。SMF上配置了终端设备MAC、DNN和域标识的对应关系，如表4所示，因此，SMF可以根据表3和表4确定会话标识(session ID)和域标识(domain ID)的对应关系，如表5所示。
表3
Figure PCTCN2019105142-appb-000006
表4
Figure PCTCN2019105142-appb-000007
表5
Figure PCTCN2019105142-appb-000008
可选的，上述举例中终端设备可以满足以下限定条件：一个终端设备MAC可以访问至少一个domain，一个终端设备MAC可以建立至少一个会话，但是一个DNN只能对应一个domain。
可选的，本申请实施例中，当SMF分配了特殊QFI时，SMF可以确定会话标识、QFI和domain ID三者之间的对应关系。
2105，SMF向UPF发送N4会话建立请求。
可选的，N4会话建立请求中携带domain ID和用户面连接标识的对应关系。这里，用户面连接标识指的是N4会话标识(N4 session ID)。N4 session ID与session ID一一对应。
可选的，N4会话建立请求中可以携带domain ID、特殊QFI和用户面连接标识的对应关系。
进一步的，N4会话建立请求中还携带报文检测规则、使用量上报规则等。报文检测规则中可以包含所述特殊QFI。
再进一步的，当由SMF分配隧道信息时，上述N4会话建立请求还携带核心网隧道信息(CN tunnel info)。此时，用户面连接标识可以是以下任一项或多项：N4会话标识、核心网隧道信息。
2106，UPF向SMF返回N4会话建立响应。
当由UPF分配隧道信息时，N4会话建立响应携带核心网隧道信息。
2107，SMF向AMF发送N1N2消息传递消息，其中携带session ID，N2 SM info， N1 SM info等。
其中，N2 SM info包含session ID，CN tunnel info，S-NSSAI等；N1 SM info包含会话建立接受、S-NSSAI、DNN等。
2108，AMF向RAN发送N2会话请求，其中携带步骤2107中的参数。
2109，RAN发起其与终端设备之间的空口建立过程。
2110，会话建立流程的其他过程，如RAN返回N2会话响应、SMF发起与UPF之间的N4会话修改等。
具体的过程描述如下：
1，RAN返回N2会话响应，携带session ID，接入网隧道信息(RAN tunnel info)等。
2，AMF向SMF发送更新会话管理上下文请求，携带1中的参数。
3，SMF向UPF发送N4会话修改请求，携带接入网隧道信息。
可选的，N4会话修改请求还携带domainID。其中，该domain ID和接入网隧道信息是对应的。
可选的，N4会话修改请求还携带domain ID和用户面连接标识的对应关系。这里，用户面连接标识可以为以下任一项或多项：接入网隧道信息、N4会话标识、核心网隧道信息。
也就是说，domain ID和用户面连接的对应关系，可以在步骤2104中下发，也可以在本步骤中下发。具体而言，在不同的步骤中下发，用户面连接的具体值不一样。例如，在步骤2104中下发，那么用户面连接标识可以为N4 session ID,和CN tunnel info中的至少一耳光。在本步骤3中下发，用户面连接标识可以为N4 session ID,CN tunnel info,和AN tunnel info中的至少一个。
4，UPF返回N4会话修改响应。
2111，UPF接收第一报文。其中，第一报文为多播报文，具体的例如第一报文为时钟同步报文。
2112，UPF根据第一报文中的domain ID字段，以及domain ID与用户面连接标识的对应关系，确定第一报文对应的用户面连接，从而通过该用户面连接向终端设备发送第一报文。
可选的，UPF可以在该时钟同步报文外层封装与该用户面连接标识对应的特殊QFI，以表明该报文为时钟同步报文。
因此，本申请实施例中，UPF在接收到多播报文之后，可以根据该多播报文中的domain ID，确定出该报文对应的用户面连接，从而通过该用户面连接向终端设备发送该多播报文。本申请实施例中，UPF无需先确定待同步的终端设备，处理逻辑相对简单。
图22示出了本申请实施例提供的一种发送报文的例子，本申请实施例中，RAN根据域标识(domain ID)和用户面连接标识的对应关系，以及第一报文中的域标识，确定第一报文对应的用户面连接，然后通过该用户面连接向终端设备发送该第一报文。作为举例，本申请实施例可以用于上文图4中的场景。
应理解，图22示出了发送报文的方法的步骤或操作，但这些步骤或操作仅是示例，本申请实施例还可以执行其他操作或者图22中的各个操作的变形。此外，图22中的各个步骤可以按照与图22呈现的不同的顺序来执行，并且有可能并非要执行图22中的全部操 作。
2201，终端设备通过RAN向AMF发送NAS消息，该NAS消息中携带会话标识(session ID)、DNN、S-NSSAI、会话建立请求等。
2202，AMF向SMF发送创建会话管理上下文请求消息。其中，创建会话管理上下文请求消息中携带终端设备的SUPI和步骤2201中的参数。
2203，SMF根据创建会话管理上下文请求消息，获取终端设备标识和会话标识的对应关系。
2204，SMF确定domain ID和会话标识的对应关系。
具体的，2201-2204可参见图21中2101-2104中的描述，为了简洁，这里不再赘述。
2205，SMF向UPF发送N4会话建立请求。其中，该N4会话建立请求中携带报文检测规则、上报规则等，其中，报文检测规则中可以包含所述特殊QFI。
当由SMF分配隧道信息时，N4会话建立请求还携带核心网隧道信息(CN tunnel info)。
2206，UPF向SMF返回N4会话建立响应。
当由UPF分配隧道信息时，N4会话建立响应携带核心网隧道信息。
2207，SMF向AMF发送N1N2消息传递消息，其中携带session ID，N2 SM info，N1 SM info等。
其中，N2 SM info包含QFI、5G服务质量标识(5G QoS Identifier，5QI)、S-NSSAI、会话标识和核心网隧道信息中的至少一种。
N1 SM info可以包含会话建立接受、S-NSSAI、DNN等。
本申请实施例中，N2 SM info还携带domain ID。进一步地，N2 SM info携带domain ID和用户面连接标识的对应关系。这里，用户面连接标识可以是以下一项或多项：会话标识、核心网隧道信息、QFI、5QI。
2208，AMF向RAN发送N2会话请求，其中携带步骤2207中的参数。
2209，RAN发起其与终端设备之间的空口建立过程。
在该过程中，RAN分配空口用户面连接标识。具体的，该空口用户面连接标识可以为数据无线承载(Data Radio Bearer，DRB)ID。此时，RAN获取了domain ID和DRB ID之间的对应关系。也就是说，RAN获取了domain ID和用户面连接标识的对应关系，用户面连接标识可以为DRB ID。
2210，会话建立流程的其他过程，如RAN返回N2会话响应、SMF发起与UPF之间的N4会话修改等。
2211，RAN接收第一报文。其中，第一报文为多播报文，例如为时钟同步报文。
2212，RAN根据第一报文中的domain ID字段，以及domain ID与用户面连接标识的对应关系，确定第一报文对应的用户面连接，从而通过该用户面连接向终端设备发送第一报文。
因此，本申请实施例中，RAN在接收到多播报文之后，可以根据该多播报文中的domain ID，确定出该报文对应的用户面连接，从而通过该用户面连接向终端设备发送该多播报文。本申请实施例中，RAN无需先确定待同步的终端设备，处理逻辑相对简单。
上述主要从不同设备之间交互的角度对本申请实施例提供的发送报文的方法的方案进行了介绍。可以理解的是，UPF、RAN或SMF为了实现上述功能，其包含了执行各个 功能相应的硬件结构和/或软件模块。结合本申请中所公开的实施例描述的各示例的单元及算法步骤，本申请实施例能够以硬件或硬件和计算机软件的结合形式来实现。某个功能究竟以硬件还是计算机软件驱动硬件的方式来执行，取决于技术方案的特定应用和设计约束条件。本领域技术人员可以对每个特定的应用来使用不同的方法来实现所描述的功能，但是这种实现不应认为超出本申请实施例的技术方案的范围。
本申请实施例可以根据上述方法示例对UPF、RAN或SMF等进行功能单元的划分，例如，可以对应各个功能划分各个功能单元，也可以将两个或两个以上的功能集成在一个处理单元中。上述集成的单元既可以采用硬件的形式实现，也可以采用软件功能单元的形式实现。需要说明的是，本申请实施例中对单元的划分是示意性的，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式。
在采用集成的单元的情况下，图23示出了本申请实施例中所涉及的一种通信装置的一种可能的示例性框图，该装置2300可以以软件、硬件或软硬结合的形式存在。图23示出了本申请实施例中所涉及的装置的一种可能的示意性框图。装置2300包括：处理单元2302和通信单元2303。处理单元2302用于对装置的动作进行控制管理。通信单元2303用于支持装置与其他设备的通信。装置还可以包括存储单元2301，用于存储装置的程序代码和数据。
图23所示的装置2300可以是本申请实施例所涉及的UPF、RAN或SMF。
当图23所示的装置2300为UPF时，处理单元2302能够支持装置2300执行上述各方法示例中由UPF完成的动作，例如，处理单元2302支持装置2300执行图21中的2112，和/或用于本文所描述的技术的其它过程。通信单元2303能够支持装置2300与SMF等之间的通信，例如，通信单元2303支持装置2300执行图21中的步骤2105、2106、2111，和/或其他相关的通信过程。
当图23所示的装置2300为RAN时，处理单元2302能够支持装置2300执行上述各方法示例中由RAN完成的动作，例如，处理单元2302支持装置2300执行图22中的2212，和/或用于本文所描述的技术的其它过程。通信单元2303能够支持装置2300与UPF和终端设备等之间的通信，例如，通信单元2303支持装置2300执行图22中的步骤2208,2211，和/或其他相关的通信过程。
当图23所示的装置2300为SMF时，处理单元2302能够支持装置2300执行上述各方法示例中由SMF完成的动作，例如，处理单元2302支持装置2300执行图21中的2103,2104，图22中的2203,2204，和/或用于本文所描述的技术的其它过程。通信单元2303能够支持装置2300与RAN或端点设备等之间的通信，例如，通信单元2303支持装置2300执行图21中的步骤2102,2105,2106,2107，图22中的步骤2202,2205,2206,2207，和/或其他相关的通信过程。
示例性地，处理单元2302可以是处理器或控制器，例如可以是中央处理器(Central Processing Unit，CPU)，通用处理器，数字信号处理器(Digital Signal Processor，DSP)，专用集成电路(Application-Specific Integrated Circuit，ASIC)，现场可编程门阵列(Field Programmable Gate Array，FPGA)或者其他可编程逻辑器件、晶体管逻辑器件、硬件部件或者其任意组合。其可以实现或执行结合本申请公开内容所描述的各种示例性的逻辑方框，单元和电路。所述处理器也可以是实现计算功能的组合，例如包含一个或多个微处理 器组合，DSP和微处理器的组合等等。通信单元2303可以是通信接口，该通信接口是统称，在具体实现中，该通信接口可以包括一个或多个接口。存储单元2301可以是存储器。
当处理单元2302为处理器，通信单元2303为通信接口，存储单元2301为存储器时，本申请实施例所涉及的装置2300可以为图24所示的通信装置2400。
参阅图24所示，该装置2400包括：处理器2402和通信接口2403。进一步地，该装置2400还可以包括存储器2401。可选的，装置2400还可以包括总线2404。其中，通信接口2403、处理器2402以及存储器2401可以通过总线2404相互连接；总线2404可以是外设部件互连标准(Peripheral Component Interconnect，PCI)总线或扩展工业标准结构(Extended Industry Standard Architecture，EISA)总线等。所述总线2404可以分为地址总线、数据总线、控制总线等。为便于表示，图24中仅用一条粗线表示，但并不表示仅有一根总线或一种类型的总线。
其中，处理器2402可以通过运行或执行存储在存储器2401内的程序，执行所述装置2400的各种功能。
示例性地，图24所示的通信装置2400可以是本申请实施例所涉及的UPF、RAN或终端设备。
当装置2400为UPF时，处理器2402可以通过运行或执行存储在存储器2401内的程序，执行上述各方法示例中由UPF完成的动作。当装置2400为RAN时，处理器2402可以通过运行或执行存储在存储器2401内的程序，执行上述各方法示例中由RAN完成的动作。当装置2400为SMF时，处理器2402可以通过运行或执行存储在存储器2401内的程序，执行上述各方法示例中由SMF完成的动作。
申请实施例还提供了一种计算机可读存储介质，包括计算机程序，当所述计算机程序在计算机上运行时，使得所述计算机执行上述方法实施例提供的方法。
本申请实施例还提供了一种包含指令的计算机程序产品，当所述计算机程序产品在计算机上运行时，使得所述计算机执行上述方法实施例提供的方法。
本申请实施例还提供了一种芯片，该芯片可应用于通信装置，该芯片包括至少一个处理器，当该至少一个处理器执行指令时，使得该芯片或该通信装置执行上述方法实施例提供的方法。可选的，该芯片还可以包括存储器，该存储器可用于存储涉及的指令。
应理解，本发明实施例中提及的处理器可以是中央处理单元(Central Processing Unit，CPU)，还可以是其他通用处理器、数字信号处理器(Digital Signal Processor，DSP)、专用集成电路(Application Specific Integrated Circuit，ASIC)、现成可编程门阵列(Field Programmable Gate Array，FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件等。通用处理器可以是微处理器或者该处理器也可以是任何常规的处理器等。
还应理解，在本申请的各种实施例中，上述各过程的序号的大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本申请实施例的实施过程构成任何限定。
还应理解，本文中涉及的第一、第二以及各种数字编号仅为描述方便进行的区分，并不用来限制本申请的范围。
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各示例的单元及 算法步骤，能够以电子硬件、或者计算机软件和电子硬件的结合来实现。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。
所属领域的技术人员可以清楚地了解到，为描述的方便和简洁，上述描述的***、装置和单元的具体工作过程，可以参考前述方法实施例中的对应过程，在此不再赘述。
在本申请所提供的几个实施例中，应该理解到，所揭露的***、装置和方法，可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个***，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性，机械或其它的形式。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，在本申请各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。
所述功能如果以软件功能单元的形式实现并作为独立的产品销售或使用时，可以存储在一个计算机可读取存储介质中。基于这样的理解，本申请的技术方案本质上或者说对现有技术做出贡献的部分或者该技术方案的部分可以以软件产品的形式体现出来，该计算机软件产品存储在一个存储介质中，包括若干指令用以使得一台计算机设备(可以是个人计算机，服务器，或者网络设备等)执行本申请各个实施例所述方法的全部或部分步骤。而前述的存储介质包括：U盘、移动硬盘、只读存储器(read-only memory，ROM)、随机存取存储器(random access memory，RAM)、磁碟或者光盘等各种可以存储程序代码的介质。
以上所述，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以所述权利要求的保护范围为准。

Claims (48)

  1. 一种同步的方法，其特征在于，所述方法由中继网络中的第一网元执行，所述中继网络包括无线接入网RAN设备和终端设备，所述方法包括：
    所述第一网元接收时钟同步报文；
    所述第一网元确定所述中继网络的第一时间，所述中继网络的第一时间包括所述RAN设备与所述终端设备之间传输所述时钟同步报文的第一下行传输时延；
    所述第一网元确定所述中继网络的时间修正域，所述时间修正域包括所述第一下行传输时延。
  2. 根据权利要求1所述的方法，其特征在于，所述时钟同步报文用于触发所述第一网元确定所述中继网络的第一时间。
  3. 根据权利要求1或2所述的方法，其特征在于，
    所述时间修正域还包括发送所述时钟同步报文的节点设备与所述中继网络之间的第二下行传输时延。
  4. 根据权利要求1-3任一项所述的方法，其特征在于，所述中继网络中还包括UPF，其中，所述第一时间还包括所述UPF与所述RAN设备之间的第三下行传输时延。
  5. 根据权利要求4所述的方法，其特征在于，所述第一时间为所述第一下行传输时延与所述第三下行传输时延之和。
  6. 根据权利要求4或5所述的方法，其特征在于，所述第一网元为所述UPF，所述第一网元确定所述中继网络的第一时间，包括：
    所述UPF获取所述第三下行传输时延；
    所述UPF向所述RAN设备发送所述时钟同步报文和第一指示信息，所述第一指示信息用于指示所述RAN设备获取所述第一下行传输时延；
    所述UPF从所述RAN设备接收所述第一下行传输时延；
    所述UPF根据所述第一下行传输时延和所述第三下行传输时延，确定所述第一时间。
  7. 根据权利要求6所述的方法，其特征在于，所述第一指示信息包括第一QFI，所述第一指示信息用于指示所述RAN设备接收到所述第一QFI对应的报文时，获取所述第一下行传输时延。
  8. 根据权利要求1-7任一项所述的方法，其特征在于，所述第一网元确定所述中继网络的第一时间，包括：
    所述第一网元根据策略信息，确定所述中继网络的第一时间，其中，所述策略信息为配置在所述第一网元上的信息，或者所述第二策略信息为从SMF接收的信息。
  9. 根据权利要求4或5所述的方法，其特征在于，所述第一网元为所述RAN设备，所述第一网元确定所述中继网络的第一时间，包括：
    所述RAN设备接收第二指示信息，所述第二指示信息用于指示所述RAN设备获取所述第一时间；
    所述RAN根据所述第二指示信息，获取所述第一下行传输时延和所述第三下行传输时延；
    所述RAN根据所述第一下行传输时延和所述第三下行传输时延，确定所述第一时间。
  10. 根据权利要求9所述的方法，其特征在于，所述第二指示信息包括第二QFI，所述第二指示信息用于指示所述RAN设备接收到所述第二QFI对应的报文时，获取所述第一时间。
  11. 根据权利要求1-10任一项所述的方法，其特征在于，所述第一网元确定所述第一时间包括：
    所述第一网元根据所述第一网元与发送所述时钟同步报文的节点设备之间的频率比率，确定所述第一时间。
  12. 根据权利要求1-11任一项所述的方法，其特征在于，还包括：
    所述第一网元向所述终端设备发送消息，所述消息携带所述时间修正域。
  13. 一种同步的装置，其特征在于，包括：
    接收单元，用于接收时钟同步报文；
    确定单元，用于确定中继网络的第一时间，所述中继网络的第一时间包括所述RAN设备与所述终端设备之间传输所述时钟同步报文的第一下行传输时延，其中，所述中继网络包括无线接入网RAN设备和终端设备，所述同步的装置为所述中继网络中的网元；
    所述确定单元还用于确定所述中继网络的时间修正域，所述时间修正域包括所述第一下行传输时延。
  14. 根据权利要求13所述的装置，其特征在于，所述时钟同步报文用于触发所述装置确定所述中继网络的第一时间。
  15. 根据权利要求13或14所述的装置，其特征在于，
    所述时间修正域还包括发送所述时钟同步报文的节点设备与所述中继网络之间的第二下行传输时延。
  16. 根据权利要求13-15任一项所述的装置，其特征在于，所述中继网络中还包括UPF，其中，所述第一时间还包括所述UPF与所述RAN设备之间的第三下行传输时延。
  17. 根据权利要求16所述的装置，其特征在于，所述第一时间为所述第一下行传输时延与所述第三下行传输时延之和。
  18. 根据权利要求16或17所述的装置，其特征在于，所述装置为所述UPF，所述确定单元具体用于：
    获取所述第三下行传输时延；
    向所述RAN设备发送所述时钟同步报文和第一指示信息，所述第一指示信息用于指示所述RAN设备获取所述第一下行传输时延；
    从所述RAN设备接收所述第一下行传输时延；
    根据所述第一下行传输时延和所述第三下行传输时延，确定所述第一时间。
  19. 根据权利要求18所述的装置，其特征在于，所述第一指示信息包括第一QFI，所述第一指示信息用于指示所述RAN设备接收到所述第一QFI对应的报文时，获取所述第一下行传输时延。
  20. 根据权利要求13-18任一项所述的装置，其特征在于，所述确定单元具体用于：
    根据策略信息，确定所述中继网络的第一时间，其中，所述策略信息为配置在所述装置上的信息，或者所述第二策略信息为从SMF接收的信息。
  21. 根据权利要求16或17所述的装置，其特征在于，所述装置为所述RAN设备，所述确定单元具体用于：
    接收第二指示信息，所述第二指示信息用于指示所述RAN设备获取所述第一时间；
    根据所述第二指示信息，获取所述第一下行传输时延和所述第三下行传输时延；
    所述第一下行传输时延和所述第三下行传输时延，确定所述第一时间。
  22. 根据权利要求21所述的装置，其特征在于，所述第二指示信息包括第二QFI，所述第二指示信息用于指示所述RAN设备接收到所述第二QFI对应的报文时，获取所述第一时间。
  23. 根据权利要求13-22任一项所述的装置，其特征在于，所述确定单元具体用于：
    根据所述装置与发送所述时钟同步报文的节点设备之间的频率比率，确定所述第一时间。
  24. 根据权利要求13-23任一项所述的装置，其特征在于，还包括：
    发送单元，用于向所述终端设备发送消息，所述消息携带所述时间修正域。
  25. 一种发送报文的方法，其特征在于，包括：
    通信网元接收第一报文，其中，所述第一报文包括域标识，所述域标识用于标识发送所述第一报文的节点设备所属的时钟域；
    所述通信网元根据域标识与用户面连接标识的对应关系，以及所述第一报文中的域标识，确定所述第一报文对应的用户面连接；
    所述通信网元通过所述第一报文对应的用户面连接向终端设备发送所述第一报文。
  26. 根据权利要求25所述的方法，其特征在于，还包括：
    所述通信网元接收来自SMF的所述域标识与用户面连接标识的对应关系。
  27. 根据权利要求25或26所述的方法，其特征在于，所述通信网元为UPF或RAN。
  28. 根据权利要求25-27任一项所述的方法，其特征在于，所述第一报文为时钟同步报文。
  29. 根据权利要求25-28任一项所述的方法，其特征在于，所述用户面连接标识包括以下至少一种：会话标识、用户面隧道信息。
  30. 一种发送报文的方法，其特征在于，包括：
    SMF确定域标识和用户面连接标识的对应关系，所述域标识用于标识发送第一报文的节点设备所属的时钟域；
    所述SMF将所述对应关系发送至通信网元，其中，所述对应关系用于所述通信网元确定向终端设备发送所述第一报文的用户面连接。
  31. 根据权利要求30所述的方法，其特征在于，所述SMF确定域标识和用户面连接标识的对应关系，包括：
    所述SMF获取终端设备标识和用户面连接标识的对应关系；
    所述SMF获取终端设备标识和域标识的对应关系，其中，所述域标识用于标识所述终端设备对应的时钟域；
    所述SMF根据终端设备标识和用户面连接标识的对应关系，以及，终端设备标识和域标识的对应关系，确定域标识和用户面连接标识的对应关系。
  32. 根据权利要求30所述的方法，其特征在于，所述SMF确定域标识和用户面连接 标识的对应关系，包括：
    所述SMF获取所述终端设备的用户面连接标识以及网络标识的对应关系，其中，所述网络标识用于标识所述终端设备接入的网络；
    所述SMF获取网络标识和域标识的对应关系，所述域标识用于标识所述终端设备对应的时钟域；
    所述SMF根据所述用户面连接标识以及网络标识的对应关系，以及，网络标识和域标识的对应关系，确定域标识和用户面连接标识的对应关系。
  33. 根据权利要求32所述的方法，其特征在于，所述网络标识包括以下至少一种：数据网络名称DNN、单网络切片选择辅助信息S-NSSAI。
  34. 根据权利要求30-33任一项所述的方法，其特征在于，所述通信网元为UPF或RAN。
  35. 根据权利要求30-34任一项所述的方法，其特征在于，所述第一报文为时钟同步报文。
  36. 根据权利要求30-35任一项所述的方法，其特征在于，所述用户面连接标识包括以下至少一种：会话标识、用户面隧道信息。
  37. 一种通信装置，其特征在于，包括：
    接收单元，用于接收第一报文，其中，所述第一报文包括域标识，所述域标识用于标识发送所述第一报文的节点设备所属的时钟域；
    确定单元，用于根据域标识与用户面连接标识的对应关系，以及所述第一报文中的域标识，确定所述第一报文对应的用户面连接；
    发送单元，用于通过所述第一报文对应的用户面连接向终端设备发送所述第一报文。
  38. 根据权利要求37所述的装置，其特征在于，所述接收单元还用于：
    接收来自SMF的所述域标识与用户面连接标识的对应关系。
  39. 根据权利要求37或38所述的装置，其特征在于，所述装置为UPF或RAN。
  40. 根据权利要求37-39任一项所述的装置，其特征在于，所述第一报文为时钟同步报文。
  41. 根据权利要求37-40任一项所述的装置，其特征在于，所述用户面连接标识包括以下至少一种：会话标识、用户面隧道信息。
  42. 一种通信装置，其特征在于，所述通信装置为SMF，包括：
    确定单元，用于确定域标识和用户面连接标识的对应关系，所述域标识用于标识发送第一报文的节点设备所属的时钟域；
    发送单元，用于将所述对应关系发送至通信网元，其中，所述对应关系用于所述通信网元确定向终端设备发送所述第一报文的用户面连接。
  43. 根据权利要求42所述的装置，其特征在于，所述确定单元具体用于：
    获取终端设备标识和用户面连接标识的对应关系；
    获取终端设备标识和域标识的对应关系，其中，所述域标识用于标识所述终端设备对应的时钟域；
    根据终端设备标识和用户面连接标识的对应关系，以及，终端设备标识和域标识的对应关系，确定域标识和用户面连接标识的对应关系。
  44. 根据权利要求42所述的装置，其特征在于，所述确定单元具体用于：
    获取所述终端设备的用户面连接标识以及网络标识的对应关系，其中，所述网络标识用于标识所述终端设备接入的网络；
    获取网络标识和域标识的对应关系，所述域标识用于标识所述终端设备对应的时钟域；
    根据所述用户面连接标识以及网络标识的对应关系，以及，网络标识和域标识的对应关系，确定域标识和用户面连接标识的对应关系。
  45. 根据权利要求44所述的装置，其特征在于，所述网络标识包括以下至少一种：数据网络名称DNN、单网络切片选择辅助信息S-NSSAI。
  46. 根据权利要求42-45任一项所述的装置，其特征在于，所述通信网元为UPF或RAN。
  47. 根据权利要求42-46任一项所述的装置，其特征在于，所述第一报文为时钟同步报文。
  48. 根据权利要求42-46任一项所述的装置，其特征在于，所述用户面连接标识包括以下至少一种：会话标识、用户面隧道信息。
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