CN113630816A

CN113630816A - Data transmission method and device

Info

Publication number: CN113630816A
Application number: CN202010374725.2A
Authority: CN
Inventors: 王亚鑫; 余芳; 孙海洋; 李岩
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-05-06
Filing date: 2020-05-06
Publication date: 2021-11-09
Also published as: WO2021223673A1

Abstract

The embodiment of the application provides a data transmission method and device, which are used for solving the problem of high packet loss rate in the base station switching process in the prior art. The method comprises the following steps: the source access network equipment determines a forwarding time delay, wherein the forwarding time delay is the time length for the source access network equipment to forward a data packet to the target access network equipment; and the source access network equipment sends the first information of the forwarding delay. In the embodiment of the application, the source access network device sends the forwarding delay information in the base station switching process, so that the target access network device can acquire the forwarding delay information, and therefore the forwarding delay of a forwarding path can be considered in air interface scheduling, and the stability and reliability of the delay sensitive service in the base station switching process can be improved.

Description

Data transmission method and device

Technical Field

The present application relates to the field of communications technologies, and in particular, to a data transmission method and apparatus.

Background

A Packet Delay Budget (PDB) is one of quality of service (QoS) parameters, and is an upper delay limit for a packet to be transmitted between a User Equipment (UE) and a User Plane Function (UPF), where the UPF refers to a UPF on a terminating N6 interface.

For ultra-reliable and low-delay communication (URLLC) services with strict delay requirements, such as remote driving communication services, the end-to-end delay is required to be less than 5ms, and the reliability reaches 99.999%. In this scenario, if the base station can obtain AN access network packet delay budget (AN PDB), that is, a PDB between the UE and the base station, the base station can reserve air interface resources in advance and optimize scheduling of the air interface resources, so as to meet a delay requirement of the URLLC service. For example, for a certain type of URLLC flow (URLLC flow), the PDB parameter value between the UE and the UPF is 5ms, the PDB between the base station and the UPF is 4ms, and the PDB between the UE and the base station is 1ms, the base station may schedule air interface resources according to the PDB requirement of 1ms, and may optimize the utilization of the air interface resources while ensuring the delay requirement of the URLLC service.

Currently, a base station acquires AN PDB through a session establishment procedure, and thus, air interface resources are scheduled according to the AN PDB in subsequent data transmission. However, in the process of switching the base station, the UE switches the RRC connection from the source base station to the target base station, and the anchor point of the core network is still at the source base station, and the target base station performs data transmission according to the AN PDB acquired by the source base station, which may cause data packet loss.

Disclosure of Invention

The embodiment of the application provides a data transmission method and device, which are used for solving the problem of high packet loss rate in the base station switching process in the prior art.

In a first aspect, an embodiment of the present application provides a data transmission method, where the method includes: the source access network equipment determines a forwarding time delay, wherein the forwarding time delay is the time length for the source access network equipment to forward a data packet to the target access network equipment; and the source access network equipment sends the first information of the forwarding delay. In the embodiment of the application, the source access network device sends the forwarding delay information in the base station switching process, so that the target access network device can acquire the forwarding delay information, and therefore the forwarding delay of a forwarding path can be considered in air interface scheduling, and the stability and reliability of the delay sensitive service in the base station switching process can be improved.

In one possible design, the source access network device may send first information of the forwarding delay to the source access and mobility management function.

In one possible design, the source access network device may send the first information of the forwarding delay to the target access network device.

In one possible design, before the source access network device sends the first information of the forwarding delay, the method further includes: the source access network equipment updates a transmission network packet delay budget (TN PDB) obtained by the source access network equipment based on the forwarding delay, and the first information is the updated TN PDB. Through the design, the updated TN PDB can reflect the forwarding delay, so that the target access network equipment can consider the forwarding delay when determining the access network packet delay budget (AN PDB) based on the updated TN PDB, and further the stability and reliability of the delay sensitive service in the base station switching process can be improved.

In one possible design, the forwarding delay includes a path forwarding delay of a data transmission path between the source access network device and the target access network device.

In one possible design, the forwarding delay includes a path forwarding delay of a data transmission path between the source access network device and the target access network device, and a processing duration when the source access network device forwards the data packet.

In a possible design, the source access network device determines the forwarding delay, and may obtain the path forwarding delay according to the configuration information stored locally. Through the design, if the source access network device locally stores the path forwarding delay, the source access network device can directly acquire the path forwarding delay.

In a possible design, the source access network device determines the forwarding time delay, may send a first data packet to the target access network device, and records the sending time of the first data packet; the source access network equipment receives a second data packet sent by the target access network equipment and records the receiving time of the second data packet; the source access network device determines a path forwarding delay based on the transmission time and the reception time. In the above design, the path forwarding delay can be obtained by measuring the round trip time of the test data packet.

In one possible design, the forwarding delay includes a forwarding delay corresponding to at least one quality of service (QoS flow).

In a second aspect, an embodiment of the present application provides a data transmission method, where the method includes: the session management function receives first information of a first forwarding delay from the target access and mobility management function, wherein the first forwarding delay comprises forwarding delays corresponding to N QoS (quality of service) flows, and N is an integer greater than 0; the session management function receives a QoS flow list from the target access and mobility management function, wherein the QoS flow list comprises at least one QoS flow which is switched by the target access network equipment in the N QoS flows; and the session management function sends second information of second forwarding delay to the target access and mobility management function, wherein the second forwarding delay comprises the forwarding delay corresponding to the QoS flow included in the QoS flow list.

In the embodiment of the application, the session management function may receive the forwarding delay transmitted by the source access network device through the target access and mobility management functions, and after the target access network device successfully switches the QoS stream, transmit the forwarding delay corresponding to the successfully switched QoS stream to the target access network device through the target access and mobility management functions, so that the target access network device may obtain the forwarding delay information of each successfully switched QoS stream, and thus, the forwarding delay of the forwarding path may be considered when performing air interface scheduling, and thus, the stability and reliability of the delay sensitive service in the base station switching process may be improved.

In one possible design, the first information includes updated TN PDBs of the N QoS flows, and the updated TN PDBs of the QoS flows are obtained by updating the TN PDBs of the QoS flows based on the forwarding delay of the QoS flows; the second information includes the updated TN PDB corresponding to the QoS flow included in the QoS flow list. Through the design, the updated TN PDB can reflect the forwarding delay, so that the target access network equipment can consider the forwarding delay when determining the AN PDB based on the updated TN PDB, and further the stability and the reliability of the delay sensitive service in the base station switching process can be improved.

In one possible design, the first information is a first forwarding delay, and the second information is a second forwarding delay; the session management function may also send a TN PDB to the target access and mobility management function, the TN PDB including TN PDBs for QoS flows included in the QoS flow list. In the design, the target access network equipment can accurately calculate the AN PDB according to the TN PDB, the forwarding delay and the PDB by sending the TN PDB and the forwarding delay.

In a third aspect, an embodiment of the present application provides a data transmission method, where the method includes: the session management function determines a forwarding time delay, wherein the forwarding time delay is the time length for forwarding a data packet to the target access network equipment by the source access network equipment; and the session management function sends the first information of the forwarding delay to the target access and mobility management function. In the embodiment of the application, the session management function may sense the forwarding delay, and send the forwarding delay information to the target access network device through the target access network device, so that the target access network device may obtain the forwarding delay information, and thus the forwarding delay of the forwarding path may be considered when performing air interface scheduling, and thus the stability and reliability of the delay sensitive service in the base station switching process may be improved.

In one possible design, before the session management function sends the first information of the forwarding delay to the target access and mobility management function, the session management function may update the packet delay budget TN PDB of the transmission network based on the forwarding delay, where the first information is the updated TN PDB. Through the design, the updated TN PDB can reflect the forwarding delay, so that the target access network equipment can consider the forwarding delay when determining the access network packet delay budget (AN PDB) based on the updated TN PDB, and further the stability and reliability of the delay sensitive service in the base station switching process can be improved.

In one possible design, the first information is a forwarding delay; the method further comprises the following steps: the session management function sends the TN PDB to the target access and mobility management function. In the design, the target access network equipment can accurately calculate the AN PDB according to the TN PDB, the forwarding delay and the PDB by sending the TN PDB and the forwarding delay.

In one possible design, before the session management function determines the forwarding delay, the method further includes: the session management function receives the processing duration from the target access and mobility management functions.

In one possible design, the session management function determines a forwarding delay, the session management function determines a first time length for the source access network device to send a data packet to the source user plane function, a second time length for the source user plane function to send a data packet to the target user plane function, and a third time length for the target user plane function to send a data packet to the target access network device; the session management function determines a path forwarding delay based on the first duration, the second duration, and the third duration. Through the design, the session management function can accurately acquire the forwarding delay.

In one possible design, the forwarding delay includes a forwarding delay corresponding to at least one quality of service QoS flow.

In a fourth aspect, an embodiment of the present application provides a data transmission method, where the method includes: the target access network equipment receives the first information of the forwarding time delay, wherein the forwarding time delay is the time length for the source access network equipment to forward the data packet to the target access network equipment; and the target access network equipment determines the delay budget of the access network packet based on the first information. In the embodiment of the application, the target access network device may obtain the forwarding delay information, so that the forwarding delay of the forwarding path may be considered when performing air interface scheduling, and thus, the stability and reliability of the delay sensitive service in the base station switching process may be improved.

In one possible design, the first information is obtained by updating the TN PDB based on the forwarding time delay; or, the first information is forwarding delay. Through the design, the updated TN PDB can reflect the forwarding delay, so that the target access network equipment can consider the forwarding delay when determining the access network packet delay budget (AN PDB) based on the updated TN PDB, and further the stability and reliability of the delay sensitive service in the base station switching process can be improved.

In one possible design, if the first information is a forwarding delay, the method further includes: the target access network device receives the TN PDB. In the design, the target access network equipment can accurately calculate the AN PDB according to the TN PDB, the forwarding delay and the PDB by sending the TN PDB and the forwarding delay.

In a fifth aspect, an embodiment of the present application provides a data transmission method, where the method includes: the first communication equipment receives first information of forwarding delay from the second communication equipment, wherein the forwarding delay is the time length for forwarding a data packet to target access network equipment by source access network equipment; the first communication device sends the first information to the third communication device. In this embodiment of the application, the source access network device may transparently transmit the forwarding delay information through the first communication device, so that the target access network device may obtain the forwarding delay information, and thus, the forwarding delay of the forwarding path may be considered when performing air interface scheduling, and thus, the stability and reliability of the delay sensitive service in the base station handover process may be improved.

In one possible design, the first information is obtained by updating the transmission network packet delay budget TN PDB based on the forwarding delay; or, the first information is forwarding delay. Through the design, the updated TN PDB can reflect the forwarding delay, so that the target access network equipment can consider the forwarding delay when determining the access network packet delay budget (AN PDB) based on the updated TN PDB, and further the stability and reliability of the delay sensitive service in the base station switching process can be improved.

In one possible design, the first communication device is a source access and mobility management function, the second communication device is a source access network device, and the third communication device is a target access and mobility management function.

In one possible design, the first communication device is a target access and mobility management function, the second communication device is a source access and mobility management function, and the third communication device is a session management function.

In one possible design, the first communication device is a target access and mobility management function, the second communication device is a session management function, and the third communication device is a target access network device.

In a sixth aspect, the present application provides a data transmission apparatus, which may be a communication device, or a chip set in the communication device, where the communication device may be an access network device or a session management function. The apparatus may comprise a processing unit and a communication unit. When the apparatus is a communication device, the processing unit may be a processor and the communication unit may be a transceiver; the apparatus may further include a storage module, which may be a memory; the storage module is configured to store an instruction, and the processing unit executes the instruction stored by the storage module to enable the access network device to perform a corresponding function in the first aspect or the fourth aspect, or the processing unit executes the instruction stored by the storage module to enable the session management function to perform a corresponding function in the second aspect or the third aspect. When the apparatus is a chip or chipset within a communication device, the processing unit may be a processor, the communication unit may be an input/output interface, a pin or a circuit, etc.; the processing unit executes the instructions stored in the storage module to make the access network device execute the corresponding functions in the first aspect or the fourth aspect, or the processing unit executes the instructions stored in the storage module to make the session management function execute the corresponding functions in the second aspect or the third aspect. The memory module may be a memory module (e.g., register, cache, etc.) within the chip or chipset, or may be a memory module (e.g., read-only memory, random access memory, etc.) external to the chip or chipset within the network device.

A seventh aspect provides a data transmission apparatus, including: a processor, a communication interface, and a memory. The communication interface is used for transmitting information, and/or messages, and/or data between the device and other devices. The memory is configured to store computer executable instructions which, when run by the apparatus, are executed by the processor to cause the apparatus to perform a method as set forth in any of the designs of the first to fifth aspects.

In an eighth aspect, the present application further provides a computer-readable storage medium having stored therein instructions, which, when run on a computer, cause the computer to perform the method as set forth in any of the first to fifth aspects above.

In a ninth aspect, the present application further provides a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method as set forth in any of the first to fifth aspects above.

In a tenth aspect, the present application further provides a wireless communication system, where the wireless communication system includes a source access network device, a session management function, and a target access network device, where the source access network device may perform the corresponding functions in the first aspect, the session management function may perform the corresponding functions in the second aspect, and the target access network device may perform the corresponding functions in the fourth aspect.

In an eleventh aspect, the present application further provides a wireless communication system, which includes a session management function and a target access network device, wherein the session management function may perform the corresponding functions in the third aspect, and the target access network device may perform the corresponding functions in the fourth aspect.

In one possible design, the wireless communication system may also include a source access network device.

In a twelfth aspect, the present application further provides a wireless communication system, where the wireless communication system includes a source access network device and a target access network device, where the source access network device may perform the corresponding functions in the first aspect, and the target access network device may perform the corresponding functions in the fourth aspect.

In a thirteenth aspect, a chip provided in this application includes a memory, at least one processor, and a communication interface, where the processor is coupled with the memory, and is configured to read a computer program stored in the memory to perform the method according to the first aspect of this application or any design of the first aspect.

In a fourteenth aspect, an embodiment of the present application provides a chip, where the chip includes a memory, at least one processor, and a communication interface, and the processor is coupled to the memory and configured to read a computer program stored in the memory to perform the method as set forth in any of the second aspect or the second aspect of the embodiment of the present application.

In a fifteenth aspect, a chip provided in this application includes a memory, at least one processor, and a communication interface, where the processor is coupled to the memory and configured to read a computer program stored in the memory to perform the method as designed in any one of the third aspect or the fourth aspect of this application.

In a sixteenth aspect, an embodiment of the present application provides a chip, where the chip includes a memory, at least one processor, and a communication interface, and the processor is coupled to the memory and configured to read a computer program stored in the memory to perform the method as set forth in any of the fourth aspect or the fourth aspect of the embodiment of the present application.

In a seventeenth aspect, an embodiment of the present application provides a chip, including a communication interface and at least one processor, where the processor is operative to perform the method according to the first aspect of the embodiment of the present application or any design of the first aspect.

In an eighteenth aspect, an embodiment of the present application provides a chip, including a communication interface and at least one processor, where the processor is operative to perform the method as set forth in any of the second aspect or the second aspect of the embodiments of the present application.

In a nineteenth aspect, an embodiment of the present application provides a chip, including a communication interface and at least one processor, where the processor is operative to perform the method as designed in any one of the third or fourth aspects of the embodiments of the present application.

In a twentieth aspect, an embodiment of the present application provides a chip, including a communication interface and at least one processor, the processor being operative to perform the method as set forth in any of the fourth or the fourth aspects of the embodiments of the present application.

It should be noted that "coupled" in the embodiments of the present application means that two components are directly or indirectly combined with each other.

Drawings

Fig. 1 is a schematic architecture diagram of a communication system according to an embodiment of the present application;

fig. 2 is a schematic flowchart of a base station acquiring AN PDB according to AN embodiment of the present disclosure;

fig. 3 is a schematic diagram of a PDB provided in an embodiment of the present application;

fig. 4 is a schematic view of another PDB provided by an embodiment of the present application;

fig. 5 is a schematic flowchart of a data transmission method according to an embodiment of the present application;

fig. 6 is a schematic diagram of a base station handover procedure according to an embodiment of the present application;

fig. 7 is a schematic diagram of transmission and forwarding delay information according to an embodiment of the present application;

fig. 8 is a schematic diagram of a base station handover procedure according to an embodiment of the present application;

fig. 9 is a schematic diagram of transmission and forwarding delay information according to an embodiment of the present application;

fig. 10 is a schematic flowchart of a data transmission method according to an embodiment of the present application;

fig. 11 is a schematic diagram of a base station handover procedure according to an embodiment of the present application;

fig. 12 is a schematic diagram of transmission and forwarding delay information according to an embodiment of the present application;

fig. 13 is a schematic diagram of a base station handover procedure according to an embodiment of the present application;

fig. 14 is a schematic diagram of transmission and forwarding delay information according to an embodiment of the present application;

fig. 15 is a schematic flowchart of a data transmission method according to an embodiment of the present application;

fig. 16 is a schematic diagram of a base station handover procedure according to an embodiment of the present application;

fig. 17 is a schematic diagram of transmission and forwarding delay information according to an embodiment of the present application;

fig. 18 is a schematic diagram of a base station handover procedure according to an embodiment of the present application;

fig. 19 is a schematic diagram of transmission and forwarding delay information according to an embodiment of the present application;

fig. 20 is a schematic structural diagram of a data transmission device according to an embodiment of the present application;

fig. 21 is a schematic structural diagram of a data transmission device according to an embodiment of the present application.

Detailed Description

To facilitate understanding of embodiments of the present application, terms related to embodiments of the present application are described below:

PDB: the upper delay bound for the transmission of a packet between the UE and the UPF over the terminating N6 interface, PDB is one of the QoS parameters. The PDB includes a transport network packet delay budget (TN PDB) and AN (AN) PDB, where TN PDB refers to AN upper delay limit for transmission between the base station and the UPF terminating the N6 interface, and AN PDB refers to AN upper delay limit for transmission between the UE and the base station.

In order to more clearly describe the technical solution of the embodiment of the present application, the following describes in detail a data transmission method and apparatus provided by the embodiment of the present application with reference to the accompanying drawings.

The architecture of the communication system may include a network open function network element, a policy control function network element, a data management network element, an application function network element, a core network access and mobility management function network element, a session management function network element, a terminal device, an access network device, a user plane function network element, and a data network. Fig. 1 shows a possible example of the architecture of the communication system, which specifically includes: a network open function (NEF) network element, a Policy Control Function (PCF), a data management (UDM) network element, AN Application Function (AF) network element, AN access and mobility management function (AMF), a Session Management Function (SMF) network element, a User Equipment (UE), AN Access Network (AN) device, a User Plane Function (UPF) and a data network (data network, DN). The AMF network element and the terminal equipment can be connected through AN N1 interface, the AMF and the AN equipment can be connected through AN N2 interface, the AN equipment and the UPF can be connected through AN N3 interface, the SMF and the UPF can be connected through AN N4 interface, and the UPF and the DN can be connected through AN N6 interface. The interface name is only an example, and the embodiment of the present application is not particularly limited thereto. It should be understood that the embodiments of the present application are not limited to the communication system shown in fig. 1, and the names of the network elements shown in fig. 1 are only illustrated as an example herein, and are not intended to limit the network elements included in the communication system architecture to which the method of the present application is applicable. The functions of the various network elements or devices in the communication system are described in detail below:

the terminal device, which may also be referred to as a User Equipment (UE), a Mobile Station (MS), a Mobile Terminal (MT), etc., is a device that provides voice and/or data connectivity to a user. For example, the terminal device may include a handheld device, a vehicle-mounted device, and the like having a wireless connection function. Currently, the terminal device may be: a mobile phone (mobile phone), a tablet computer, a notebook computer, a palm top computer, a Mobile Internet Device (MID), a wearable device, a Virtual Reality (VR) device, an Augmented Reality (AR) device, a wireless terminal in industrial control (industrial control), a wireless terminal in self-driving (self-driving), a wireless terminal in remote surgery (remote medical supply), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation safety (transportation safety), a wireless terminal in city (smart city), a wireless terminal in smart home (smart home), and the like. The terminal device in fig. 1 is shown as a UE, which is only an example and is not limited to the terminal device.

The radio access network may be AN shown in fig. 1, and provides radio access services to the terminal device. The access network device is a device for accessing the terminal device to a wireless network in the communication system. The access network device is a node in a radio access network, which may also be referred to as a base station, and may also be referred to as a Radio Access Network (RAN) node (or device). Currently, some examples of access network devices are: a new generation Node B (gbb), a Transmission Reception Point (TRP), an evolved Node B (eNB), a Radio Network Controller (RNC), a Node B (NB), a Base Station Controller (BSC), a Base Transceiver Station (BTS), a home base station (e.g., a home evolved Node B or a home Node B, HNB), a Base Band Unit (BBU), or a wireless fidelity (Wifi) Access Point (AP), etc.

The data network, such as the DN shown in fig. 1, may be the Internet (Internet), an IP Multimedia Service (IMS) network, a local network (i.e., a local network such as a Mobile Edge Computing (MEC) network), and so on. The data network comprises an application server, and the application server provides service for the terminal equipment by carrying out data transmission with the terminal equipment.

The core network is used for accessing the terminal equipment to DN which can realize the service of the terminal equipment. The following describes the functions of each network element in the core network:

the access and mobility management function network element may be configured to manage access control and mobility of the terminal device, and in practical application, the access and mobility management function network element includes a mobility management function in a Mobility Management Entity (MME) in a network frame in Long Term Evolution (LTE), and is added with an access management function, and may be specifically responsible for registration, mobility management, tracking area update procedure, reachability detection, selection of a session management function network element, mobility state transition management, and the like of the terminal device. For example, in 5G, the access and mobility management function network element may be referred to as an AMF network element, for example, as shown in fig. 1, and in future communication, for example, in 6G, the access and mobility management function network element may still be referred to as an AMF network element, or by other names, which is not limited in this application.

The session management functional network element may be configured to be responsible for session management (including establishment, modification, and release of a session) of the terminal device, selection and reselection of a user plane functional network element, Internet Protocol (IP) address allocation, quality of service (QoS) control, and the like of the terminal device. For example, in 5G, the session management function network element may be referred to as an SMF network element, for example, as shown in fig. 1, and in future communication, as in 6G, the session management function network element may still be referred to as an SMF network element, or by other names, which is not limited in this application.

The policy control function network element can be used for taking charge of policy control decision, providing functions of service data flow and application detection, gating, QoS (quality of service) and flow-based charging control and the like. For example, in 5G, the policy control function network element may be referred to as a PCF network element, for example, as shown in fig. 1, and in future communication, for example, in 6G, the policy control function network element may still be a PCF network element, or have another name, which is not limited in this application.

The application function network element mainly functions to interact with a 3rd generation partnership project (3 GPP) core network to provide services, so as to affect service flow routing, access network capability opening, policy control and the like. For example, in 5G, the application function network element may be referred to as an AF network element, for example, as shown in fig. 1, and in future communications, for example, in 6G, the application function network element may still be an AF network element, or have another name.

The data management network element may be configured to manage subscription data of the terminal device, registration information related to the terminal device, and the like. For example, in 5G, the data management network element may be referred to as a unified data management network element (UDM), for example, as shown in fig. 1, and in future communications, for example, as in 6G, the data management network element may still be referred to as a UDM network element or by other names, which is not limited in this application.

The network open function network element may be configured to enable the 3GPP to securely provide network service capabilities to AFs (e.g., Service Capability Servers (SCS), Application Servers (AS), etc.) of third parties. For example, in 5G, the network open function network element may be referred to as NEF, for example, as shown in fig. 1, and in future communication, for example, in 6G, the network open function network element may still be referred to as NEF network element, or have another name, which is not limited in this application.

The above network elements in the core network may also be referred to as functional entities, and may be network elements implemented on dedicated hardware, or may be software instances running on dedicated hardware, or may be instances of virtualized functions on a suitable platform, for example, the above virtualized platform may be a cloud platform.

It should be noted that the architecture of the communication system shown in fig. 1 is not limited to include only the network elements shown in the figure, and may also include other devices not shown in the figure, which are not specifically listed here.

It should be noted that the embodiment of the present application does not limit the distribution form of each network element in the core network, and the distribution form shown in fig. 1 is only an example, and the present application is not limited.

For convenience of description, in the following description, the network element shown in fig. 1 is taken as an example, and the XX network element is directly abbreviated as XX, for example, an SMF network element is referred to as SMF. It should be understood that the names of all network elements in the present application are only used as examples, and may also be referred to as other names in future communications, or network elements referred to in the present application may also be replaced by other entities or devices with the same function in future communications, and the present application does not limit the present application. The unified description is made here, and the description is not repeated.

The communication system shown in fig. 1 is not intended to limit the communication system to which the embodiments of the present application can be applied. The communication system architecture shown in fig. 1 is a 5G system architecture, and optionally, the method of the embodiment of the present application is also applicable to various future communication systems, such as a 6G or other communication networks.

For URLLC service with strict delay requirement, such as remote driving communication service, the end-to-end delay is required to be less than 5ms, and the reliability reaches 99.999%. In this scenario, if the base station can acquire the AN PDB, the air interface resource can be reserved in advance and scheduling of the air interface resource can be optimized to meet the delay requirement of the URLLC service. For example, for a certain type of URLLC flow, the PDB parameter value between the UE and the UPF is 5ms, and the TN PDB between the base station and the UPF is 4ms, so that the AN PDB between the UE and the base station is 1ms, and thus the base station can schedule air interface resources according to the AN PDB requirement of 1ms, and can optimize the utilization of the air interface resources while ensuring the delay requirement of the URLLC service.

Currently, a base station acquires AN PDB through a session establishment procedure, and thus, air interface resources are scheduled according to the AN PDB in subsequent data transmission. For example, as shown in fig. 2, the process of acquiring AN PDB by the base station may include:

s201, the UE sends a PDU session establishment request to the AMF.

S202, AMF selects SMF, SMF selects PCF and UPF.

S203, the PCF sends Policy and Charging Control (PCC) policy to the SMF, wherein the PCC policy includes 5G QoS identifier (5G QoS identifier, 5 QI).

The SMF may determine the PDB between the UE and the UPF according to the 5G QoS corresponding to the 5 QI.

S204, the SMF sends a session establishment request to the UPF.

If the SMF does not store the TN PDB between the base station and the UPF, the session establishment/modification request may carry indication information, where the indication information is used to request the UPF to feed back the TN PDB.

S205, the UPF sends a session establishment response to the SMF.

If the session establishment/modification request carries the indication information requesting the UPF to feed back the TN PDB, the session establishment/modification response may carry the TN PDB or TN path information.

It will be appreciated that TN PDB information between and among the various base stations is pre-configured on the UPF.

S206, the SMF sends the PDB related information to the AMF.

For example, the PDB related information is AN PDB calculated by the SMF according to the TN PDB and the 5QI, and the PDB related information is TN PDB and 5QI determined by the SMF according to the TN path information.

S207, the AMF sends the PDB related information to the base station.

And S208, the base station determines the AN PDB according to the PDB related information and performs scheduling control according to the QoS flow corresponding to the AN PDB.

S209, the base station and the UE interactively complete air interface configuration, and the RAN, the AMF and the SMF interactively complete updating of PDU session management context, and complete a session establishment process.

It can be seen from the above that, the base station schedules air interface resources according to the AN PDB in the subsequent data transmission by acquiring the AN PDB in the PDU session establishment process. However, in the process of switching the base station, since the UE switches the RRC connection from the source base station to the target base station and the anchor point of the core network is still at the source base station, in the process of switching the base station, the downlink data transmission process is as follows: the core network equipment sends data to the source base station, and then the source base station forwards the data to the target base station, and then the target base station sends the data to the UE. Similarly, the uplink data transmission process is as follows: the UE sends data to the target base station, the target base station forwards the data to the source base station, and the source base station sends the data to the core network equipment. Due to the existence of the transmission process between the source base station and the target base station in the base station switching process, the PDB between the target base station and the UE is lower than the AN PDB acquired by the source base station, and the target base station schedules air interface resources according to the AN PDB acquired by the source base station to perform data transmission, which may cause data packet loss.

For example, the PDB between the UE and the UPF is 10ms, the TN PDB between the UPF and the source base station is 5ms, and thus the AN PDB acquired by the source base station is 5ms, but in the base station handover process, assuming that the transmission process between the source base station and the target base station takes 2ms, the PDB between the target base station and the UE is 3 ms. However, according to the current data transmission method, the target base station schedules air interface resources according to the 5ms AN PDB for data transmission, which may cause data packet loss.

Based on this, the present application provides a data transmission method and apparatus, so as to solve the problem in the prior art that the packet loss rate is high in the base station handover process. The method and the device are based on the same inventive concept, and because the principles of solving the problems of the method and the device are similar, the implementation of the device and the method can be mutually referred, and repeated parts are not repeated.

It should be understood that "at least one" in the embodiments of the present application means one or more, "a plurality" means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a alone, both A and B, and B alone, where A, B may be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, a and b, a and c, b and c, or a, b and c, wherein a, b and c can be single or multiple.

In the description of the present application, it is to be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance, nor as indicating or implying order or even representing numbers.

The data transmission method provided by the embodiment of the application can be applied to a base station switching scene, wherein when the UE moves from one base station to another base station, the base station switching is required.

In one implementation scenario, an Xn user plane forwarding tunnel may exist between a source access network device (source RAN, S-RAN) and a target access network device (target RAN, T-RAN), that is, an Xn-U interface exists between the S-RAN and the T-RAN, so that the S-RAN and the T-RAN may transmit data through the user plane forwarding tunnel. For example, in the downlink transmission process, the transmission delay between the S-RAN and the T-RAN is the delay generated by the process of forwarding the data packet from the S-RAN to the T-RAN, as shown in fig. 3. It is understood that the Xn user plane forwarding tunnel may be established between the S-RAN and the T-RAN, or the Xn user plane forwarding tunnel may be a tunnel that is forwarded through other base stations. For example, an Xn user plane tunnel is established between the S-RAN and the base station 1, and an Xn user plane tunnel is established between the base station 1 and the T-RAN, so that data can be transmitted between the S-RAN and the T-RAN through the base station 1.

In another implementation scenario, there may also be no Xn user plane forwarding tunnel between the S-RAN and the T-RAN, that is, the S-RAN and the T-RAN may transmit data through the SMF configured source UPF (source UPF, S-UPF) and target UPF (target UPF, T-UPF), that is, the S-UPF and the T-UPF serve as forwarding network elements, for example, in downlink transmission, the S-RAN forwards a data packet to the T-RAN in a process that the S-RAN forwards a data packet to the S-UPF, the S-UPF forwards the data packet to the T-UPF, the T-UPF forwards the data packet to the T-RAN, and the transmission delay between the S-RAN and the T-RAN is the delay generated by the S-RAN- > S-UPF- > T-RAN, as shown in fig. 4. In uplink transmission, the process of forwarding a data packet to an S-RAN by a T-RAN is that the T-RAN forwards the data packet to a T-UPF, the T-UPF forwards the data packet to the S-UPF, and the S-UPF forwards the data packet to the S-RAN, and the transmission delay between the T-RAN and the S-RAN is the delay generated when the T-RAN- > T-UPF- > S-RAN transmits the data packet. The S-UPF and the T-UPF may be the same network element or different network elements. If the S-UPF and the T-UPF are the same network element, the data forwarding process of the S-UPF and the T-UPF can not be executed.

The data transmission method provided by the present application is specifically described below with reference to the accompanying drawings.

The first embodiment is as follows: the method may be applied in the scenario shown in fig. 3. In the first embodiment, an Xn user plane forwarding tunnel is established between the S-RAN and the T-RAN, but no Xn control plane forwarding tunnel is established, i.e. there is an Xn-U interface between the S-RAN and the T-RAN, but no Xn-C interface. As shown in fig. 5, the method may include:

s501, the S-RAN determines a first forwarding time delay, wherein the first forwarding time delay is the time length for the S-RAN to forward a data packet to the T-RAN.

Illustratively, the first forwarding delay may comprise a path forwarding delay of a data transmission path between the S-RAN and the T-RAN. The data transmission path between the S-RAN and the T-RAN may be an Xn user plane forwarding tunnel established between the S-RAN and the T-RAN, or a data transmission path forwarded through another base station.

Alternatively, the first forwarding delay may also include a path forwarding delay of a data transmission path between the S-RAN and the T-RAN, and a processing duration when the S-RAN forwards the data packet. The processing time length when the S-RAN forwards the data packet may be a Packet Data Convergence Protocol (PDCP) layer processing delay.

In one implementation, the path forwarding delay may be determined as follows: the S-RAN may obtain the path forwarding delay according to locally stored configuration information.

In another implementation, the path forwarding delay may also be determined as follows: the S-RAN sends a first data packet to the T-RAN and records the sending time of the first data packet; the S-RAN receives a second data packet sent by the T-RAN and records the receiving time of the second data packet; the S-RAN determines a path forwarding delay based on the transmission time and the reception time, e.g., the path forwarding delay may be equal to 0.5 × (reception time-transmission time).

In an exemplary illustration, the forwarding delay may be QoS Flow granularity, for example, in step S501, the S-RAN may determine forwarding delays corresponding to N QoS flows, and the first forwarding delay may include forwarding delays corresponding to N QoS flows, where N is an integer greater than 0.

S502, the S-RAN sends the first information of the first forwarding delay to the S-AMF. Accordingly, the S-AMF receives first information of a first forwarding delay from the S-RAN.

In an implementation manner, the first information may be obtained by updating the TN PDB based on the first forwarding delay. In an implementation manner, before the S-RAN sends the first information of the first forwarding delay, the TN PDB acquired by the S-RAN may be updated based on the first forwarding delay to obtain an updated TN PDB, where the updated TN PDB is the first information. For example, assuming that the first forwarding delay is 2ms and the TN PDB is 5ms, the updated TN PDB may be equal to the sum of the first forwarding delay and the TN PDB, i.e., 7 ms.

Further, if the forwarding delay is QoS Flow granularity, the S-RAN may update the TN PDB of the QoS Flow according to the forwarding delay corresponding to the QoS Flow, so as to obtain the updated TN PDB of the QoS Flow. Therefore, the first information may include updated TN PDBs of N QoS flows, and the updated TN PDBs of the QoS flows are obtained by updating the TN PDBs of the QoS flows based on the forwarding delay of the QoS flows.

In another implementation, the first information may be the first forwarding delay.

S503, the S-AMF sends the first information of the first forwarding delay to the T-AMF. Accordingly, the T-AMF receives the first information of the first forwarding delay from the S-AMF.

S504, the T-AMF sends the first information of the first forwarding delay to the SMF. Accordingly, the SMF receives the first information of the first forwarding delay from the T-AMF.

S505, the T-AMF sends a QoS Flow list to the SMF, wherein the QoS Flow list comprises configuration information of at least one QoS Flow for which the T-RAN accepts switching. Accordingly, the SMF receives the QoS Flow list from the T-AMF.

In one implementation, the SMF may trigger the T-RAN to authenticate the session before step S505. For example, the SMF may instruct the T-RAN to verify at least one session through the T-AMF, determine to receive the session for handover after the T-RAN verifies the at least one session, and feed back configuration (Profile) information of QoS Flow corresponding to the session for handover to the T-AMF.

S506, the SMF sends second information of second forwarding delay to the T-AMF, wherein the second forwarding delay comprises forwarding delay corresponding to QoS Flow included in the QoS Flow list.

In an implementation manner, if the first information includes updated TN PDBs of N QoS flows, the second information may include updated TN PDBs corresponding to the QoS flows included in the QoS Flow list.

In another implementation, if the first information is the first forwarding delay, the second information may be the second forwarding delay. In an exemplary illustration, the first forwarding delay may include forwarding delays corresponding to N QoS flows, respectively, and the second information may include forwarding delays corresponding to QoS flows included in the QoS Flow list, respectively. The second forwarding delay may be a subset of the first forwarding delay. In another exemplary illustration, the forwarding delays of the N QoS flows may be the same, so the first forwarding delay may be one forwarding delay value, and the second forwarding delay and the first forwarding delay may be the same.

In this implementation, the SMF may also send a TN PDB to the T-AMF, the TN PDB including a TN PDB of the QoS Flow included in the QoS Flow list.

S507, the T-AMF sends second information to the T-RAN.

The T-RAN determines AN AN PDB based on the second information S508.

In AN exemplary illustration, taking QoS Flow 1 as AN example, if the second information includes TN PDB updated by QoS Flow 1, the AN PDB of QoS Flow 1 may be equal to the difference between the PDB of QoS Flow 1 and the TN PDB updated by QoS Flow 1.

In another exemplary illustration, taking QoS Flow 1 as AN example, if the second information includes forwarding delay corresponding to QoS Flow 1, the AN PDB of QoS Flow 1 may be equal to the difference between the PDB of QoS Flow 1 minus the TN PDB of QoS Flow 1, and minus the forwarding delay corresponding to QoS Flow 1.

It should be noted that the T-AMF and the S-AMF may be the same network element or different network elements. If the T-AMF and the S-AMF are the same network element, the actions of the S-AMF and the T-AMF may be performed by the same network element, and the interaction process between the S-AMF and the T-AMF may not be performed in the processes of S501 to S507.

In the embodiment of the application, the S-RAN sends the forwarding delay information to the T-RAN in the switching process of the base station, so that the T-RAN can consider the forwarding delay of a forwarding path when carrying out air interface scheduling, and the stability and the reliability of the delay sensitive service in the switching process of the base station can be improved.

In order to better understand the scheme provided by the embodiment of the present application, taking T-AMF and S-AMF as examples, which are different network elements, a base station handover procedure is described below with reference to specific examples.

Example one:

as shown in fig. 6, the base station handover procedure may include:

s601, the S-RAN determines the forwarding time delay.

For example, the S-RAN may determine that there is an Xn user plane transmission path with the T-RAN by querying local information, i.e., there is a Xn-U connection. The S-RAN may obtain the path forwarding delay of the data transmission path between the S-RAN and the T-RAN according to the preconfigured information, or obtain the path forwarding delay of the data transmission path between the S-RAN and the T-RAN by sending a measurement data packet. The specific process may refer to the related description of S501, and is not described here again.

And S602, the S-RAN updates the value of the TN-PDB according to the forwarding delay.

For example, if the forwarding delay is 6ms and the TN-PDB is 4ms, the S-RAN may associate the forwarding delay with the TN-PDB and the updated TN-PDB, i.e., the updated TN-PDB is 10 ms.

S603, the S-RAN sends a switching request message to the S-AMF, and the switching request message can carry the updated TN PDB.

For example, the Handover request message may be a Handover Required message, and it should be understood that this is merely an example, and in other access systems or in future communication development, the updated TN PDB may also be carried by other messages, which is not limited herein.

S604, if the T-RAN is not in the service range of the S-AMF, the S-AMF selects the T-AMF serving the T-RAN according to the identification information of the T-RAN.

S605, the S-AMF sends a request message for creating UE context to the T-AMF, and the request message for creating UE context can carry the updated TN PDB.

For example, the UE context creation Request message may be a naf _ Communication _ createcontext Request message, and it should be understood that this is only an example, and in other access systems or in future Communication developments, the updated TN PDB may also be carried by other messages, which is not limited herein.

S606, the T-AMF sends a Session Management (SM) context request message to the SMF, and the SM context request message can carry the updated TN PDB.

For example, the update SM context Request message may be a Namf _ pdusesion _ update smcontext Request message, and it should be understood that this is only an example, and in other access systems or in future communication development, the updated TN PDB may also be carried by other messages, which is not limited herein.

S607, the SMF controls to establish an uplink tunnel between a PDU Session Anchor (PSA) and the T-UPF.

S608, the SMF feeds back the path establishment situation to the T-AMF, wherein the path establishment situation can comprise session and QoS Flow information which are allowed to be switched by the T-UPF.

S609, the T-AMF sends a switching request to the T-RAN, wherein the switching request comprises a session and a QoS Flow list which are allowed to be switched by the T-UPF.

Step S610 may be executed when the T-AMF receives the Response messages of all PDU sessions, or when the maximum waiting time is reached, or step S610 may be executed after the T-AMF receives the Response messages of all PDU sessions, or after the maximum waiting time is reached.

S610, the T-RAN sends a switching request confirmation message to the T-AMF, and the switching request confirmation message can carry session and QoS Flow information of the T-RAN for receiving switching.

For example, the Handover Request Acknowledge message may be a Handover Request Acknowledge message, and it should be understood that this is merely an example, and in other access systems or in future communication development, session and QoS Flow information for accepting Handover may also be carried by other messages through the T-RAN, and this is not limited herein.

S611, the T-AMF sends an SM context updating response message to the SMF, wherein the SM context updating response message can carry session and QoS Flow information of the T-RAN for receiving the switching.

For example, the SM context update Response message may be an Nsmf _ pdusesion _ update smcontext Response message, and it should be understood that this is only an example, and in other access systems or in future communication development, session and QoS Flow information for accepting handover may also be carried in other messages, which is not specifically limited herein.

S612, the SMF sends the updated TN PDB corresponding to the QoS Flow which the T-RAN accepts the switching to the T-AMF.

Illustratively, the SMF may also send a 5QI corresponding to the QoS Flow that the T-RAN accepts handover to the T-AMF.

S613, the T-AMF sends a switching command to the T-RAN, and the switching command carries the updated TN PDB corresponding to the QoS Flow which the T-RAN receives the switching. The handover command may also carry a 5QI corresponding to the QoS Flow for which the T-RAN accepts handover.

For example, the Handover Command may be a Handover Command message, and it should be understood that this is merely an example, and in other access systems or in future communication development, the updated TN PDB corresponding to the QoS Flow for which the T-RAN receives a Handover may also be carried by other messages, which is not limited herein.

And S614, the T-RAN calculates and updates the AN PDB according to the updated TN PDB corresponding to the QoS Flow and the PDB information in the 5QI of each QoS Flow.

For example, if the updated TN PDB for the QoS Flow is 12ms, the PDB in the 5QI of the QoS Flow is 20ms, and the AN PDB of the QoS Flow is 8 ms.

S615, the T-RAN sends a switching command to the UE, and the switching command is used for indicating the UE to be switched to the T-RAN.

S616, the UE performs a base station handover procedure.

In AN example, for a scenario in which AN Xn user plane transmission tunnel exists between RANs, AN S-RAN may obtain a forwarding delay with a T-RAN, update a TN-PDB, and forward the forwarding delay to the T-RAN through a path of the S-RAN- > S-AMF- > T-AMF- > SMF- > T-AMF- > T-RAN, as shown in fig. 7, so that the T-RAN may consider a factor of the forwarding delay when determining the AN PDB, and thus may improve stability and reliability of a delay-sensitive service in a base station handover procedure.

Example two:

as shown in fig. 8, the base station handover procedure may include:

s801 may refer to S601 specifically, and is not described herein again.

S802 to S805 are similar to S603 to S606 described above, except that S603 to S606 carry the updated TN PDB and S802 to S805 carry the forwarding delay.

S806 to S810, which may specifically refer to S607 to S611 described above, are not described herein again.

S811 to S812 are similar to S612 to S613, except that S612 to S613 carry updated TN PDB corresponding to the QoS Flow for which the T-RAN accepts handover, and S811 to S812 carry forwarding delay corresponding to the QoS Flow for which the T-RAN accepts handover.

S813 to S815, refer to S614 to S616 specifically, and are not described herein again.

Example two, for a scenario in which AN Xn user plane transmission tunnel exists between RANs, AN S-RAN may obtain a forwarding delay between the S-RAN and a T-RAN, and forward the forwarding delay to the T-RAN through a path of S-RAN- > S-AMF- > T-AMF- > SMF- > T-AMF- > T-RAN, as shown in fig. 9, so that the T-RAN may consider a factor of the forwarding delay when determining AN PDB, thereby improving stability and reliability of a delay-sensitive service in a base station handover procedure.

Example two: the method may be applied to the scenario shown in fig. 4, in which an Xn user plane forwarding tunnel and an Xn control plane forwarding tunnel are not established between the S-RAN and the T-RAN in the scenario shown in fig. 4, that is, Xn-U and Xn-C interfaces are not established between the S-RAN and the T-RAN. As shown in fig. 10, the method may include:

s1001, SMF determines a first forwarding delay, wherein the first forwarding delay is the time length for the S-RAN to forward the data packet to the T-RAN.

Illustratively, the first forwarding delay may comprise a path forwarding delay of a data transmission path between the S-RAN and the T-RAN. The data transmission path between the S-RAN and the T-RAN may be a path forwarded through a core network device, for example, the data transmission path between the S-RAN and the T-RAN may be S-RAN- > S-UPF- > T-RAN.

In one implementation, the processing duration may be received from a T-AMF. For example, the S-RAN may determine a processing duration and send to the SMF via the T-AMF.

Illustratively, the path forwarding delay may be determined as follows: the SMF determines a first time length for sending a data packet to the S-UPF by the S-RAN, a second time length for sending the data packet to the T-UPF by the S-UPF, and a third time length for sending the data packet to the T-RAN by the T-UPF; the SMF determines a path forwarding delay based on the first time length, the second time length and the third time length. For example, the path forwarding delay may be equal to the sum of the first duration, the second duration, and the third duration.

In an exemplary illustration, the forwarding delay may be QoS Flow granularity, for example, in step S1001, the SMF may determine forwarding delays corresponding to N QoS flows, where N is an integer greater than 0.

S1002, the SMF sends first information of the first forwarding delay to the T-AMF. Accordingly, the T-AMF may receive the first information from the SMF.

In an implementation manner, the first information may be obtained by updating the TN PDB based on the first forwarding delay. In this implementation, before the SMF sends the first information, the TN PDB may be updated based on the first forwarding delay to obtain an updated TN PDB, where the updated TN PDB is the first information. For example, assuming that the first forwarding delay is 2ms and the TN PDB is 5ms, the updated TN PDB may be equal to the sum of the first forwarding delay and the TN PDB, i.e., 7 ms.

Further, if the forwarding delay is of the QoS Flow granularity, the SMF may update the TN PDB of the QoS Flow with respect to the forwarding delay corresponding to the QoS Flow, so as to obtain the updated TN PDB of the QoS Flow. Therefore, the first information may include updated TN PDBs of N QoS flows, and the updated TN PDBs of the QoS flows are obtained by updating the TN PDBs of the QoS flows based on the forwarding delay of the QoS flows.

In another implementation, the first information may be a first forwarding delay.

In an implementation, the SMF may also send a TN PDB to the T-AMF.

S1003, the T-AMF sends the first information to the T-RAN. Accordingly, the T-RAN receives the first information from the T-AMF.

In one implementation, the T-AMF may further send a TN PDB to the T-RAN if the first information is the first forwarding delay.

The T-RAN determines AN AN PDB based on the first information S1004.

S1004 may specifically refer to the description related to S508, which is not described herein again.

Example three:

as shown in fig. 11, the base station handover procedure may include:

S1101-S1104 are similar to S603-S606, except that S603-S606 carry updated TN PDB, and S1101-S1109 do not carry updated TN PDB. Optionally, the processing duration may be carried in steps S1101 to S1104.

Optionally, before step S1101, the S-RAN may find that there is no Xn connection with the T-RAN by querying local information, and the handover control plane message needs to be forwarded through the N2 interface. And the forwarding of the user plane data also needs to be configured through the N2 interface. The S-RAN decides to trigger the N2 handover.

S1105 to S1109, which may specifically refer to S607 to S611, and are not described herein again.

S1110, the SMF establishes a forwarding tunnel between the S-UPF and the T-UPF.

S1111, the SMF determines the updated TN PDB corresponding to the QoS Flow switched by the T-RAN according to the QoS Flow information switched by the T-RAN, the path forwarding delay and the TN PDB of each QoS Flow, optionally according to the processing time length.

S1112 to S1116, refer to the above S612 to S616 specifically, and are not described herein again.

In the third example, the S-RAN sends the processing time to the SMF through the S-AMF and the T-AMF, and after the SMF configures the forwarding tunnels of the S-UPF and the T-UPF, the SMF calculates and updates the TN PDB according to the path forwarding time delay and the processing time as well as the TN PDB and sends the updated TN PDB to the T-RAN through the T-AMF, as shown in fig. 12, so that the T-RAN can consider the factor of the forwarding time delay when determining the AN PDB, and thus the stability and reliability of the delay sensitive service in the base station switching process can be improved.

Example four:

as shown in fig. 13, the base station handover procedure may include:

s1301 to S1310, refer to S1101 to S1110 specifically, and are not described herein again.

S1311, the SMF determines, according to the QoS Flow information and the path forwarding delay for the T-RAN to accept the handover, optionally, according to the processing duration, the forwarding delay corresponding to the QoS Flow for the T-RAN to accept the handover.

S1312 to S1316 are similar to S1113 to S1116, and are different in that S1113 to S1116 carry updated TN PDB corresponding to the QoS Flow for which the T-RAN accepts handover, and S1312 to S1316 carry forwarding delay corresponding to the QoS Flow for which the T-RAN accepts handover.

In the fourth example, the S-RAN sends the processing time to the SMF through the S-AMF and the T-AMF, and after the SMF configures the forwarding tunnels of the S-UPF and the T-UPF, the SMF calculates the forwarding time according to the path forwarding time delay and the processing time and sends the forwarding time to the T-RAN through the T-AMF, as shown in fig. 14, so that the T-RAN can consider the factor of the forwarding time delay when determining the AN PDB, thereby improving the stability and reliability of the delay sensitive service in the base station handover process.

Example three: the method may be applied to the scenario shown in fig. 3, where an Xn control plane forwarding tunnel is established between the S-RAN and the T-RAN in the scenario shown in fig. 3, that is, an Xn-C interface exists between the S-RAN and the T-RAN. As shown in fig. 15, the method may include:

s1501, the S-RAN determines a first forwarding time delay, wherein the first forwarding time delay is the time length for the S-RAN to forward the data packet to the T-RAN.

S1501 may specifically refer to the description related to S501, and is not repeated herein.

S1502, the S-RAN sends the first information of the first forwarding delay to the T-RAN. Accordingly, the T-RAN receives first information of a first forwarding delay from the S-RAN.

A manner of sending the first information to the T-RAN by the S-RAN in S1502 is the same as that of sending the first information to the S-AMF by the S-RAN in S502, which may specifically refer to the related description of S502, and is not repeated here.

In one implementation, if the first information is the first forwarding delay, the S-RAN may further send a TN PDB to the T-RAN.

S1503, the T-RAN determines AN PDB based on the first information.

The method for determining the AN PDB by the T-RAN according to the first information in S1503 is the same as the method for determining the AN PDB by the T-RAN according to the second information in S508, and reference may be specifically made to the related description of S508, and details are not repeated here.

In order to better understand the scheme provided in the embodiment of the present application, a base station handover procedure is described below with reference to a specific example.

Example five:

as shown in fig. 16, the base station handover procedure may include:

s1601, the AMF sends mobility control information to the S-RAN. The mobility control information is used to indicate information such as roaming information and access restriction of the UE.

S1602, the UE reports measurement information to the S-RAN, for example, the measurement information may include Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), and the like.

S1603, the S-RAN determines to switch the UE to the T-RAN in an Xn switching mode according to the measurement information reported by the UE and a local strategy.

S1604 to S1605, refer to S601 and S602 specifically, and are not described herein again.

S1606, the S-RAN sends a handover request message to the T-RAN, where the handover request message may carry the updated TN PDB. In addition, the handover request message may also carry 5 QI.

And S1607, the T-RAN calculates the AN PDB in the switching process according to the updated TN PDB and the PDB corresponding to the 5 QI.

S1608, the T-RAN determines and controls whether or not to allow handover.

S1609, the T-RAN sends a handover request confirm message to the S-RAN, the handover request confirm message is used to indicate to accept the handover of the UE. The Handover request acknowledgement message may include a Handover Command (Handover Command) for instructing the UE to access the T-RAN through a random access procedure.

For example, the Handover Request Acknowledge message may be a Handover Request Acknowledge message, and it should be understood that this is merely an example, and in other access schemes or in future communication developments, the Handover of the UE may also be indicated by other messages, which is not specifically limited herein.

S1610, the base station switching process.

For a scenario in which AN Xn user plane transmission tunnel exists between RANs, AN S-RAN may obtain a forwarding delay with a T-RAN, update a TN-PDB, and forward the forwarding delay to the T-RAN through the Xn control plane transmission tunnel between the S-RAN and the T-RAN, as shown in fig. 17, so that the T-RAN may consider a factor of the forwarding delay when determining AN PDB, thereby improving stability and reliability of a delay sensitive service in a base station handover procedure.

Example six:

as shown in fig. 18, the base station handover procedure may include:

s1801 to S1804 may specifically refer to S1601 to S1604, which are not described herein.

S1805, the S-RAN sends a handover request message to the T-RAN, where the handover request message may carry a forwarding delay and a TN PDB. In addition, the handover request message may also carry 5 QI.

And S1806, the T-RAN calculates AN AN PDB in the switching process according to the forwarding delay, the TN PDB and the PDB corresponding to the 5 QI.

S1807 to S1809, refer to S1608 to S1610 specifically, which are not described herein again.

For a scenario in which AN Xn user plane transmission tunnel exists between RANs, AN S-RAN may obtain a forwarding delay between the S-RAN and a T-RAN, and forward the forwarding delay to the T-RAN through the Xn user plane transmission tunnel between the S-RAN and the T-RAN, as shown in fig. 19, so that the T-RAN may consider a factor of the forwarding delay when determining AN PDB, thereby improving stability and reliability of a delay sensitive service in a base station handover procedure.

Based on the same technical concept as the method embodiment, the embodiment of the application provides a data transmission device. The apparatus may be configured as shown in fig. 20, and includes a processing unit 2001 and a communication unit 2002.

In an implementation manner, the data transmission apparatus may specifically be used to implement the method performed by the source access network device (S-RAN) in the embodiments of fig. 5 to 9 and 15 to 19, where the apparatus may be the source access network device, or may be a chip or a chip set in the source access network device or a part of the chip for performing the function of the related method. The processing unit 2001 is configured to determine a forwarding delay, where the forwarding delay is a duration for forwarding a data packet from a source access network device to a target access network device. A communication unit 2002 for transmitting the first information of the forwarding delay.

Optionally, the processing unit 2001 may be further configured to: before the communication unit 2002 sends the first information of the forwarding delay, the TN PDB of the transport network packet delay budget acquired by the source access network device is updated based on the forwarding delay, and the first information is the updated TN PDB.

Illustratively, the forwarding delay may include a path forwarding delay of a data transmission path between the source access network device and the target access network device.

Alternatively, the forwarding delay may include a path forwarding delay of a data transmission path between the source access network device and the target access network device, and a processing time length when the source access network device forwards the data packet.

In some embodiments, the processing unit 2001, when determining the forwarding time delay, may specifically be configured to: and acquiring the path forwarding time delay according to the locally stored configuration information.

In other embodiments, the processing unit 2001, when determining the forwarding time delay, may specifically be configured to: sending a first data packet to the target access network device through the communication unit 2002, and recording the sending time of the first data packet; receiving a second data packet sent by the target access network device through the communication unit 2002, and recording the receiving time of the second data packet; a path forwarding delay is determined based on the transmit time and the receive time.

Illustratively, the forwarding delay includes a forwarding delay corresponding to at least one quality of service QoS flow.

In one implementation, the data transmission apparatus may specifically be used to implement a method executed by a session management function (AMF) in the embodiments of fig. 5 to fig. 9, and the apparatus may be the AMF, or may also be a chip in the AMF or a chip set or a part of a chip for executing a function of a related method. Therein, the communication unit 2002 is configured to communicate with the target access and mobility management function. A processing unit 2001 for executing, by the communication unit 2002: receiving first information of a first forwarding delay from a target access and mobility management function, wherein the first forwarding delay comprises forwarding delays corresponding to N QoS (quality of service) flows, and N is an integer greater than 0; receiving a QoS flow list from a target access and mobility management function, wherein the QoS flow list comprises at least one QoS flow which is switched by a target access network device in the N QoS flows; and sending second information of a second forwarding delay to the target access and mobility management function, wherein the second forwarding delay comprises the forwarding delay corresponding to the QoS flow included in the QoS flow list.

For example, the first information may include updated TN PDBs of the N QoS flows, and the updated TN PDBs of the QoS flows are obtained by updating the TN PDBs of the QoS flows based on the forwarding delay of the QoS flows. The second information may include an updated TN PDB corresponding to the QoS flow included in the QoS flow list.

Or, the first information may be a first forwarding delay, and the second information may be a second forwarding delay;

optionally, the processing unit 2001 may be further configured to: the TN PDB, which includes the TN PDB of the QoS flows included in the QoS flow list, is sent to the target access and mobility management function through the communication unit 2002.

Illustratively, the forwarding delay may comprise a path forwarding delay of a data transmission path between the source access network device and the target access network device.

Alternatively, the forwarding delay may also include a path forwarding delay of a data transmission path between the source access network device and the target access network device, and a processing duration when the source access network device forwards the data packet.

In one implementation, the data transmission apparatus may specifically be used to implement the method performed by the session management function (AMF) in the embodiments shown in fig. 10 to fig. 14, and the apparatus may be the AMF, or may also be a chip in the AMF or a chip set or a part of a chip for performing a function of a related method. The processing unit 2001 is configured to determine a forwarding delay, where the forwarding delay is a duration for forwarding a data packet from a source access network device to a target access network device. A communication unit 2002, configured to send the first information of the forwarding delay to the target access and mobility management function.

Optionally, the processing unit 2001 may be further configured to: before the communication unit 2002 sends the first information of the forwarding delay to the target access and mobility management function, the packet delay budget TN PDB of the transmission network is updated based on the forwarding delay, and the first information is the updated TN PDB.

Illustratively, the first information may be a forwarding delay. The communication unit 2002 may also be configured to: and sending the TN PDB to a target access and mobility management function.

Optionally, the communication unit 2002 may be further configured to: the processing duration is received from the target access and mobility management functions before the processing unit 2001 determines the forwarding delay.

In some embodiments, the processing unit 2001, when determining the forwarding time delay, may specifically be configured to: determining a first time length for transmitting a data packet to a source user plane function by a source access network device, a second time length for transmitting the data packet to a target user plane function by the source user plane function, and a third time length for transmitting the data packet to the target access network device by the target user plane function; and determining the path forwarding time delay based on the first time length, the second time length and the third time length.

In one implementation, the data transmission apparatus may specifically be used to implement the method performed by the source access network device (S-RAN) in the embodiments shown in fig. 5 to fig. 19, and the apparatus may be the source access network device, or may be a chip or a chip set in the source access network device, or a part of a chip in the chip for performing the function of the related method. The communication unit 2002 is configured to receive first information of a forwarding delay, where the forwarding delay is a duration for a source access network device to forward a data packet to a target access network device; a processing unit 2001, configured to determine an access network packet delay budget based on the first information.

Exemplarily, the first information may be obtained by updating the TN PDB based on the forwarding delay; alternatively, the first information may be a forwarding delay.

Optionally, if the first information is forwarding delay, the communication unit 2002 may further be configured to: a TN PDB is received.

The division of the modules in the embodiments of the present application is schematic, and only one logical function division is provided, and in actual implementation, there may be another division manner, and in addition, each functional module in each embodiment of the present application may be integrated in one processor, may also exist alone physically, or may also be integrated in one module by two or more modules. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. It is understood that the functions or implementations of the respective modules in the embodiments of the present application may further refer to the related description of the method embodiments.

In a possible manner, the data transmission apparatus may be as shown in fig. 21, and the apparatus may be a communication device or a chip in the communication device, where the communication device may be an access network device and may also be a session management function. The apparatus may include a processor 2101, a communication interface 2102, a memory 2103. The processing unit 2001 may be the processor 2101, among others. The communication unit 2002 may be a communication interface 2102.

The processor 2101 may be a Central Processing Unit (CPU), a digital processing unit, or the like. The communication interface 2102 may be a transceiver, an interface circuit such as a transceiver circuit, or the like, a transceiver chip, or the like. The device also includes: the memory 2103 is used for storing programs executed by the processor 2101. The memory 2103 may be a non-volatile memory, such as a Hard Disk Drive (HDD) or a solid-state drive (SSD), and may also be a volatile memory, such as a random-access memory (RAM). The memory 2103 is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to such.

The processor 2101 is configured to execute the program codes stored in the memory 2103, and in particular, to execute the actions of the processing unit 2001, which are not described herein again. The communication interface 2102 is specifically configured to perform the operations of the communication unit 2002, which is not described herein again.

The specific connection medium among the communication interface 2102, the processor 2101, and the memory 2103 is not limited in the embodiments of the present application. In the embodiment of the present application, the memory 2103, the processor 2101, and the communication interface 2102 are connected by the bus 2104 in fig. 21, the bus is indicated by a thick line in fig. 21, and the connection manner between the other components is only schematically illustrated and is not limited. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown in FIG. 21, but this does not mean only one bus or one type of bus.

The embodiment of the present invention further provides a computer-readable storage medium, which is used for storing computer software instructions required to be executed for executing the processor, and which contains a program required to be executed for executing the processor.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. A method of data transmission, the method comprising:

determining a forwarding time delay by source access network equipment, wherein the forwarding time delay is the time length for the source access network equipment to forward a data packet to target access network equipment;

and the source access network equipment sends the first information of the forwarding delay.

2. The method of claim 1, wherein prior to the source access network device transmitting the first information of the forwarding delay, the method further comprises:

and the source access network equipment updates the TN PDB acquired by the source access network equipment based on the forwarding delay, and the first information is the updated TN PDB.

3. The method of claim 1 or 2, wherein the forwarding delay comprises a path forwarding delay of a data transmission path between the source access network device and the target access network device;

or, the forwarding delay includes a path forwarding delay of a data transmission path between the source access network device and the target access network device, and a processing duration when the source access network device forwards a data packet.

4. The method of claim 3, wherein the determining, by the source access network device, a forwarding delay comprises:

and the source access network equipment acquires the path forwarding delay according to locally stored configuration information.

5. The method of claim 3, wherein the determining, by the source access network device, a forwarding delay comprises:

the source access network equipment sends a first data packet to the target access network equipment and records the sending time of the first data packet;

the source access network equipment receives a second data packet sent by the target access network equipment and records the receiving time of the second data packet;

the source access network device determines the path forwarding delay based on the sending time and the receiving time.

6. The method of any of claims 1-5, wherein the forwarding delay comprises a forwarding delay for at least one quality of service (QoS) flow.

7. A method of data transmission, the method comprising:

a session management function receives first information of a first forwarding delay from a target access and mobility management function, wherein the first forwarding delay comprises forwarding delays corresponding to N QoS (quality of service) flows, and N is an integer greater than 0;

the session management function receiving a QoS flow list from the target access and mobility management function, the QoS flow list comprising at least one QoS flow of the N QoS flows for which a target access network device accepts handover;

and the session management function sends second information of second forwarding delay to the target access and mobility management function, wherein the second forwarding delay comprises the forwarding delay corresponding to the QoS flow included in the QoS flow list.

8. The method of claim 7, wherein the first information comprises an updated TN PDB of the N QoS flows, and the updated TN PDB of the QoS flows is obtained by updating the TN PDB of the QoS flows based on forwarding delays of the QoS flows;

the second information includes the updated TN PDB corresponding to the QoS flow included in the QoS flow list.

9. The method of claim 7, wherein the first information is the first forwarding delay and the second information is the second forwarding delay;

the method further comprises the following steps:

and the session management function sends TN PDB to the target access and mobility management function, wherein the TN PDB comprises TN PDBs of the QoS flows included in the QoS flow list.

10. The method of any of claims 7 to 9, wherein the forwarding delay comprises a path forwarding delay of a data transmission path between a source access network device and a target access network device;

or, the forwarding delay includes a path forwarding delay of a data transmission path between the source access network device and the target access network device, and a processing duration when the source access network device forwards the data packet.

11. A method of data transmission, the method comprising:

the session management function determines a forwarding delay, wherein the forwarding delay is the time length for forwarding a data packet to the target access network equipment by the source access network equipment;

and the session management function sends the first information of the forwarding delay to a target access and mobility management function.

12. The method of claim 11, wherein prior to the session management function sending the first information of the forwarding delay to a target access and mobility management function, the method further comprises:

and the session management function updates a transmission network packet delay budget TN PDB based on the forwarding delay, and the first information is the updated TN PDB.

13. The method of claim 11, wherein the first information is the forwarding delay;

the method further comprises the following steps:

and the session management function sends TN PDB to the target access and mobility management function.

14. The method of any of claims 11-13, wherein the forwarding delay comprises a path forwarding delay for a data transmission path between the source access network device and the target access network device.

15. The method of any of claims 11-13, wherein the forwarding delay comprises a path forwarding delay of a data transmission path between the source access network device and the target access network device, and a processing duration when the source access network device forwards a data packet.

16. The method of claim 15, wherein prior to the session management function determining the forwarding delay, the method further comprises:

the session management function receives the processing duration from the target access and mobility management function.

17. The method of any of claims 14-16, wherein the session management function determining a forwarding delay comprises:

the session management function determines a first time length for the source access network equipment to send a data packet to a source user plane function, a second time length for the source user plane function to send a data packet to a target user plane function, and a third time length for the target user plane function to send a data packet to the target access network equipment;

the session management function determines the path forwarding delay based on the first duration, the second duration, and the third duration.

18. The method of any of claims 11-17, wherein the forwarding delay comprises a forwarding delay for at least one quality of service (QoS) flow.

19. A method of data transmission, the method comprising:

the target access network equipment receives first information of forwarding delay, wherein the forwarding delay is the time length for forwarding a data packet to the target access network equipment by source access network equipment;

and the target access network equipment determines the delay budget of the access network packet based on the first information.

20. The method of claim 19, wherein the first information is obtained by updating a TN PDB based on the forwarding delay;

or, the first information is the forwarding delay.

21. The method of claim 20, wherein if the first information is the forwarding delay, the method further comprises:

the target access network equipment receives the TN PDB.

22. The method according to any of claims 19-21, wherein the forwarding delay comprises a forwarding delay for at least one quality of service, QoS, flow.

23. A data transmission apparatus, comprising:

a communication interface for communicating with other devices;

a memory for storing computer programs and data;

a processor for running the computer program in the memory, reading the computer program in the memory, and executing the method according to any one of claims 1-6 through the communication interface.

24. A data transmission apparatus, comprising:

a communication interface for communicating with other devices;

a memory for storing computer programs and data;

a processor for executing the computer program in the memory, reading the computer program in the memory, and executing the method according to any one of claims 7-10 via the communication interface.

25. A data transmission apparatus, comprising:

a communication interface for communicating with other devices;

a memory for storing computer programs and data;

a processor for executing the computer program in the memory, reading the computer program in the memory, and executing the method according to any one of claims 11-18 through the communication interface.

26. A data transmission apparatus, comprising:

a communication interface for communicating with other devices;

a memory for storing computer programs and data;

a processor for executing the computer program in the memory, reading the computer program in the memory, and executing the method according to any one of claims 19-22 through the communication interface.

27. A computer storage medium, in which a computer program is stored which, when executed by a computer, causes the computer to perform the method of any one of claims 1-22.