WO2022083627A1

WO2022083627A1 - Transmission method and device

Info

Publication number: WO2022083627A1
Application number: PCT/CN2021/124929
Authority: WO
Inventors: 周叶; 周锐
Original assignee: 大唐移动通信设备有限公司
Priority date: 2020-10-21
Filing date: 2021-10-20
Publication date: 2022-04-28
Also published as: CN114390619A; CN114390619B

Abstract

Provided by the present application are a transmission method and device, a method applied to a first radio access network element comprising: the first radio access network element sends first information to a terminal, the first information being used to indicate a correspondence between a PDCP count value of a first bearer and a PDCP count value of a second bearer of the terminal, or being used to indicate a correspondence between a PDCP serial number of the first bearer and a PDCP serial number of the second bearer of the terminal.

Description

Transmission method and device

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application No. 202011133038.8 filed in China on October 21, 2020, the entire contents of which are incorporated herein by reference.

technical field

The present disclosure relates to the field of wireless communication technologies, and in particular, to a transmission method and device.

Background technique

In a wireless communication system, there are scenarios in which multiple user terminals (User Equipment, UE) request the same downlink service data. For this scenario, in order to minimize the consumption of wireless resources, a multicast mechanism is proposed in the related art, which allows the network to send a single piece of downlink data by using a specific wireless resource, and multiple user terminals simultaneously receive this piece of downlink data. In contrast, traditional downlink data that can only be received by one user terminal is called a unicast mechanism.

In order to cope with the complex air interface environment and diversified service transmission quality of service (Quality of Service, QoS) requirements, the related technology puts forward the following requirements: for each point to multipoint (Point to Multipoint, PTM) mechanism to send For downstream data flow, the network side can still send it to a specific user terminal in a point-to-point (Point to Point, PTP) mode as appropriate. That is, the network should be able to dynamically adjust the downlink transmission mode between the PTM and PTP modes for a certain user terminal.

In addition, during the handover process for a certain user terminal, for the downlink data that the user terminal fails to receive through the handover source cell, the handover source node can forward it to the target cell for transmission, that is, "data forwarding"; If the downlink data is multicast data, even if it is sent by PTM in the source cell, since only the user terminal being handed over needs to receive the data, the data should still be sent by PTP. After receiving, send new data through PTM.

SUMMARY OF THE INVENTION

The present disclosure provides a transmission method and device for solving the problem of discontinuous data transmission if there is a downlink transmission mode switch and/or a switch involving changing the network element where the PDCP is located during downlink data transmission.

In order to solve the above technical problems, the present disclosure provides a transmission method, which is applied to a first radio access network element, including:

The first radio access network element sends first information to the terminal, where the first information is used to indicate the correspondence between the PDCP count value of the first bearer of the terminal and the PDCP count value of the second bearer, Or used to indicate the correspondence between the PDCP sequence number of the first bearer of the terminal and the PDCP sequence number of the second bearer.

Optionally, the first bearer is a source radio bearer or a temporary radio bearer, and the second bearer is a target radio bearer.

Optionally, the first information includes the offset between the PDCP count values of the first bearer and the second bearer or includes the difference between the PDCP sequence numbers of the first bearer and the second bearer. offset.

Optionally, the first information includes second information and third information, the second information is the count value or sequence number of the first PDCP data packet in the first bearer, and the third information is the The count value or sequence number of the second PDCP data packet in the second bearer; the first PDCP data packet is the data packet that has been terminated for reception in the first bearer, and the second PDCP data packet is the second PDCP data packet. The packet started to be received in the bearer;

The service data included in the first PDCP data packet and the second PDCP data packet are both first service data.

Optionally, after the first radio access network element sends the first information to the terminal, the method further includes:

The first radio access network element releases the first bearer.

Optionally, before the first radio access network element sends the first information to the terminal, the method further includes:

receiving, by the first radio access network element, fourth information sent by a user plane function module in the core network, where the fourth information includes a first flag for the first service data;

receiving, by the first radio access network element, fifth information sent by a second radio access network element, where the fifth information includes a second flag for the first service data;

One of the first marker and the second marker is a start marker, and the other is an end marker.

Optionally, the fifth information further includes a count value or a sequence number of a first PDCP data packet in the first bearer, where the first PDCP data packet is a data packet in the first bearer that is terminated for reception.

Optionally, the method further includes:

The first radio access network element determines the first information according to the fourth information and the fifth information.

Optionally, before the step of sending the first information to the terminal by the first radio access network element, the method further includes:

The first radio access network element receives sixth information sent by the second radio access network element, where the sixth information is used to indicate the corresponding relationship.

The present disclosure also provides a transmission method, applied to a terminal, including:

The terminal receives the first information sent by the first radio access network element, where the first information is used to indicate the correspondence between the PDCP count value of the first bearer of the terminal and the PDCP count value of the second bearer , or used to indicate the correspondence between the PDCP sequence number of the first bearer of the terminal and the PDCP sequence number of the second bearer.

Optionally, the method further includes:

If the terminal has successfully received the third PDCP data packet through the first bearer, and successfully received the fourth PDCP data packet through the second bearer, and the count value or sequence number of the fourth PDCP data packet is the same as the If the count value or sequence number of the third PDCP data packet is corresponding, then discard the fourth PDCP data packet;

or,

If the terminal has successfully received the fourth PDCP data packet through the second bearer, and successfully received the third PDCP data packet through the first bearer, and the count value or sequence number of the third PDCP data packet is the same as that of the third PDCP data packet. If the count value or sequence number of the fourth PDCP data packet is corresponding, the third PDCP data packet is discarded.

Optionally, after receiving the first information sent by the first radio access network element, the terminal further includes:

If the terminal successfully receives the fifth PDCP data packet through the first bearer, and its count value or sequence number is greater than or equal to the count value or sequence number in the first PDCP data packet, discard the fifth PDCP data packet. PDCP packets.

If the terminal successfully receives the sixth PDCP data packet through the second bearer, and its count value or sequence number is less than or equal to the count value or sequence number in the second PDCP data packet, discard the sixth PDCP data packet. PDCP packets.

The terminal releases the first bearer.

The present disclosure also provides a transmission method, which is applied to a user plane functional module in a core network, including:

The user plane function module receives seventh information sent by the session management function module in the core network; wherein the seventh information is used to indicate that the downlink transmission address for the terminal is changed from the first address to the second address;

The user plane function module sends an end marker for the terminal and for the first service data to the access network element corresponding to the first address, and sends an end marker for the access network element corresponding to the second address. The terminal and for the start marker of the first service data.

The present disclosure also provides a wireless access network element, including a memory, a transceiver, and a processor:

a memory for storing a computer program; a transceiver for sending and receiving data under the control of the processor; a processor for reading the computer program in the memory and performing the following operations:

Send first information to the terminal, where the first information is used to indicate the correspondence between the PDCP count value of the first bearer of the terminal and the PDCP count value of the second bearer, or the first information of the terminal. Correspondence between the PDCP sequence number of the bearer and the PDCP sequence number of the second bearer.

Optionally, after the sending the first information to the terminal, the method further includes:

The first bearer is released.

Optionally, before the sending the first information to the terminal, the method further includes:

receiving fourth information sent by a user plane function module in the core network, where the fourth information includes a first flag for the first service data;

receiving fifth information sent by a second radio access network element, where the fifth information includes a second flag for the first service data;

Optionally, the processor is further configured to perform the following operations:

The first information is determined according to the fourth information and the fifth information.

Optionally, before the step of sending the first information to the terminal, the method further includes:

Receive sixth information sent by the network element of the second radio access network, where the sixth information is used to indicate the corresponding relationship.

The present disclosure also provides a terminal, including a memory, a transceiver, and a processor:

Receive the first information sent by the network element of the first radio access network, where the first information is used to indicate the correspondence between the PDCP count value of the first bearer of the terminal and the PDCP count value of the second bearer, or use Indicates the correspondence between the PDCP sequence number of the first bearer of the terminal and the PDCP sequence number of the second bearer.

If the third PDCP data packet has been successfully received through the first bearer, and the fourth PDCP data packet has been successfully received through the second bearer, and the count value or sequence number of the fourth PDCP data packet is the same as that of the third PDCP data packet If the count value or sequence number of the PDCP data packet is corresponding, then discard the fourth PDCP data packet;

or,

If the fourth PDCP data packet has been successfully received through the second bearer, and the third PDCP data packet has been successfully received through the first bearer, and the count value or sequence number of the third PDCP data packet is the same as the fourth PDCP data packet If the count value or sequence number of the PDCP data packet is corresponding, the third PDCP data packet is discarded.

Optionally, after receiving the first information sent by the first radio access network element, the method further includes:

If the fifth PDCP data packet is successfully received through the first bearer, and its count value or sequence number is greater than or equal to the count value or sequence number in the first PDCP data packet, discard the fifth PDCP data packet .

If the sixth PDCP data packet is successfully received through the second bearer, and its count value or sequence number is less than or equal to the count value or sequence number in the second PDCP data packet, discard the sixth PDCP data packet .

The first bearer is released.

The present disclosure also provides a user plane function module, the user plane function module is located in the core network, and includes a memory, a transceiver, and a processor:

receiving seventh information sent by the session management function module in the core network; wherein the seventh information is used to indicate that the downlink transmission address for the terminal is changed from the first address to the second address;

Send an end marker for the terminal and for the first service data to the access network element corresponding to the first address, and send an end marker for the terminal and for the first service data to the access network element corresponding to the second address. The start tag of the first service data is described.

The present disclosure also provides a wireless access network element, including:

The first information sending unit is configured to send first information to the terminal, where the first information is used to indicate the correspondence between the PDCP count value of the first bearer of the terminal and the PDCP count value of the second bearer, or use Indicates the correspondence between the PDCP sequence number of the first bearer of the terminal and the PDCP sequence number of the second bearer.

The present disclosure also provides a terminal, including:

a first information receiving unit, configured to receive first information sent by a first radio access network element, where the first information is used to indicate the PDCP count value of the first bearer of the terminal and the PDCP count value of the second bearer The corresponding relationship between, or used to indicate the corresponding relationship between the PDCP sequence number of the first bearer of the terminal and the PDCP sequence number of the second bearer.

The present disclosure also provides a user plane function module, the user plane function module is located in the core network, including:

The change instruction unit is used to receive the seventh information sent by the session management function module in the core network; wherein, the seventh information is used to indicate that the downlink transmission address for the terminal is changed from the first address to the second address;

a data transmission instructing unit, configured to send an end marker for the terminal and for the first service data to the access network element corresponding to the first address, and send the end marker to the access network element corresponding to the second address A start marker for the terminal and for the first service data.

The present disclosure also provides a processor-readable storage medium, where a computer program is stored in the processor-readable storage medium, and the computer program is used to cause the processor to execute any one of the above methods.

The beneficial effects of the above-mentioned technical solutions of the present disclosure are as follows:

In the embodiment of the present disclosure, the radio access network informs the user terminal of the correspondence between the PDCP count values or sequence numbers of the two radio bearers before and after the handover, thereby ensuring service continuity.

Description of drawings

Figure 1 is a schematic diagram of the 5G NR network architecture;

2 is a schematic flowchart of a transmission method in Embodiment 1 of the present disclosure;

3 is a schematic flowchart of a transmission method in Embodiment 2 of the present disclosure;

4 is a schematic flowchart of a transmission method in Embodiment 3 of the present disclosure;

5 is a schematic flowchart of handover between different gNB-CU-UPs within a gNB in an embodiment of the present disclosure;

FIG. 6 is a schematic flowchart of another handover between different gNB-CU-UPs within a gNB according to an embodiment of the present disclosure;

FIG. 7 is a schematic flowchart of handover between different gNBs in an embodiment of the present disclosure;

8 is a schematic flowchart of another handover between different gNBs in an embodiment of the present disclosure;

FIG. 9 is a schematic structural diagram of a network element of a wireless access network according to Embodiment 4 of the present disclosure;

FIG. 10 is a schematic structural diagram of a terminal in Embodiment 5 of the present disclosure;

11 is a schematic structural diagram of a user plane functional module in Embodiment 6 of the present disclosure;

12 is a schematic structural diagram of a network element of a wireless access network according to Embodiment 7 of the present disclosure;

13 is a schematic structural diagram of a terminal in Embodiment 8 of the present disclosure;

FIG. 14 is a schematic structural diagram of a user plane function module in Embodiment 9 of the present disclosure.

Detailed ways

In the embodiments of the present disclosure, the term "and/or" describes the association relationship of associated objects, and indicates that there can be three kinds of relationships. For example, A and/or B can indicate that A exists alone, A and B exist at the same time, and B exists alone these three situations. The character "/" generally indicates that the associated objects are an "or" relationship.

In the embodiments of the present application, the term "plurality" refers to two or more than two, and other quantifiers are similar.

The following first introduces the related technologies involved in the embodiments of the present application, and briefly introduces some technical problems discovered by the inventor when analyzing and researching the related technologies.

1. About air interface PTM transmission:

In a wireless communication system, there are scenarios in which multiple user terminals request the same downlink service data. In order to reduce operating costs, the related art proposes the function of "air interface PTM transmission", which allows the network side of a wireless cell to send a single copy of downlink data using specific radio resources, and multiple user terminals simultaneously receive and decode the downlink data. , so as to achieve the purpose of sending downlink data to multiple user terminals by the network using one wireless communication resource. This mode is called PTM. In contrast, the network sends a single piece of downlink data through a specific radio resource, and only one user terminal receives and decodes the transmission mode is called PTP.

For the traditional PTP mode, a cell can dynamically adjust the air interface transmission parameters according to the channel quality between the base station and the unicast receiving terminal, such as adjusting the modulation and coding scheme (MCS) and beam direction to maximize the frequency spectrum usage efficiency. However, for the PTM mode, the signal transmission of the base station needs to take care of all user terminals within the cell range as much as possible, which may even include not in the radio resource control (Radio Resource Control, RRC) connection state, so the network does not know its location and channel. quality user terminal. In view of this, the network side often has to adopt relatively conservative air interface transmission parameters, such as MCS with lower code rate and omnidirectional transmission, that is, using more air interface resources to transmit less information.

Multicast is applicable to various scenarios, including services such as live broadcast of civilian video platforms, which have stricter latency requirements and looser reliability requirements, and others, such as police information distribution, which have looser latency requirements and stricter reliability requirements. Business. For the latter, generally, every terminal that receives the service can receive all the data in the service as much as possible.

2. 5G New Radio (NR) network architecture and handover process:

Please refer to Figure 1. The 5G NR network architecture is divided into two parts: the core network and the access network. In the 5G core network, network elements closely related to handover include AMF, SMF and UPF.

AMF refers to the Access and Mobility Management Function (Access and Mobility Management Function), which is the core module in the network. Each user terminal is connected to only one AMF at the same time.

SMF refers to a session management function module (Session Management Function). The AMF manages the SMF through the N _smf interface, such as requesting the SMF to establish, modify, and release the service context. The business data in 5G is managed in the form of sessions according to business attributes, IP routing of the backbone network, etc. Each session is managed by only one SMF. In each session, according to the QoS requirements of different service data, it can be subdivided into one or more service flows.

UPF refers to User Plane Function. The SMF manages the UPF through the N4 interface, such as requesting the UPF to establish, modify, and release a transmission channel for service data. In principle, the northbound UPF exchanges service data with the external data network (eg, backbone network) through the N6 interface, and the southbound exchanges service data with the access network through the N3 interface. If the access network is a 5G wireless access network, the N3 interface is also called the NG-U interface, that is, the user plane part of the NG interface. Sometimes a data link is also sent through two UPFs successively, and the interface between the two UPFs is called an N9 interface.

The 5G access network, also known as NG-RAN, consists of NG-RAN nodes. The node NG-RAN node using New Radio (NR) technology is also called gNB. Each gNB can be subdivided into one gNB-CU and one or more gNB-DUs, and each gNB-CU can be further subdivided into one gNB-CU-CP and one or more gNB-CU-UPs.

gNB-CU-CP refers to the control plane (Control Plane) part of the central unit (Central Unit) in the gNB, and is the core module in the gNB. , that is, the control plane part in the NG interface) is connected to the AMF. Each user terminal can be connected to multiple gNB-CU-CPs at the same time, but only one of them is the primary gNB-CU-CP, and there is an N2 context related to the user terminal between it and the AMF. Different gNB-CU-CPs are connected through the Xn-C interface. According to its own policy, the gNB-CU-CP maps one or more QoS flows in each session to a radio bearer for air interface transmission. The gNB-CU-CP is also responsible for sending a radio resource control (Radio Resource Control, RRC) message to the user terminal to instruct it how to configure the air interface link. These messages RRC messages are sent and received through the Packet Data Convergence Protocol (Protocol Data Unit, PDCP) layer.

gNB-CU-UP refers to the user plane (User Plane) part of the central unit (Central Unit) in the gNB. The gNB-CU-CP manages the gNB-CU-UP through the E1 interface, such as requesting the gNB-CU-UP to establish, modify, and release the transmission channel of service data. In principle, the northbound gNB-CU-UP exchanges service data with the UPF through the N3 interface, and the southbound exchanges service data with the gNB-DU through the F1-U interface. The gNB-CU-UP mainly includes the Service Data Adaptation Protocol (SDAP) and the PDCP layer. The main function of the SDAP layer is to map the service flow to a radio bearer according to the instructions of the gNB-CU-CP. Each radio bearer is handled using one PDCP instance. For downlink data, the PDCP instance numbers each data packet in chronological order, and the numbered value is called the PDCP count value (PDCP COUNT). The lowest bits of the PDCP count value are truncated as the Serial Number.

gNB-DU refers to a distributed unit (Distributed Unit) in a gNB. The gNB-CU-CP manages the gNB-DU through the F1-C interface, such as requesting the gNB-DU to establish, modify, and release air interface resources. The gNB-DU mainly includes radio link control (Radio Link Control, RLC), media access control (Media Access Control, MAC), physical (PHY) and radio frequency (RF) layers.

Each network layer in the gNB has a corresponding network layer in the user terminal.

The PDCP layer of the receiver has functions such as reordering and de-redundancy, that is, it can ensure that the data submitted to the SDAP layer are delivered in order and without redundancy. The fact that data is not missing is often guaranteed by the RLC layer, but in some special scenarios, it is also guaranteed by the PDCP layer.

Broadly speaking, handover refers to the operation of changing the transmission path within the 5G network for a service. During the handover process that involves changing the network element where the PDCP is located (that is, originally transmitted through one PDCP, but changed to another PDCP at a certain time, such as the handover process between different gNB-CU-UPs within one gNB, and different handover process between gNBs), in order to improve the continuity of downlink services sent in the form of PTP, and even meet the requirements of lossless and on-demand delivery, the source PDCP of the handover will provide the target PDCP of the handover with the information received from the core network but not yet available. Data delivered to the user terminal, this mechanism is called "data forwarding".

In the 5G network, the radio access network nodes can independently decide which service flows are mapped to which radio bearers (RBs). , its PDCP serial number may also be different.

If the mapping of service flows on the source side and the target side to the radio bearer is the same (which is the usual case), data forwarding can be performed according to the granularity of the radio bearer, and each data packet contains a sequence number. At the same time, the source also provides the target with a PDCP transmission status summary on the source side, which indicates which PDCP data packets the UE has successfully received over the air interface in the form of a PDCP count value. During the switching process, UPF will send an end marker to each session on the old path, and all subsequent data will be sent through the new path. When the source PDCP receives the end identifier sent by the UPF, it will know that the session is no longer transmitted through the N3 channel on the source side, and the previously received data packet is the last data packet transmitted through the channel. Thereafter, for each radio bearer, when all the data that needs to be forwarded on the radio bearer have been sent to the target PDCP, the source PDCP will send an end identifier. When the target PDCP receives the end identifier for the radio bearer, it will know that the data forwarding for the radio bearer has ended. Thereafter, for new packets it receives from the UPF via the SDAP layer, the numbering will continue above the count value of the last packet forwarded by the data. This mechanism ensures that when the user terminal receives data, the count value of the PDCP is continuous, and the content of the data packet is also continuous.

However, if the data target PDCP of the service is being sent in PTM mode during the handover process, in order not to interfere with the service continuity of other user terminals receiving the service, the PDCP count value cannot be adjusted for the user terminal being switched. Therefore, the result of "continuous numbering above the count value of the last data packet forwarded by the data" cannot be achieved, and thus the service continuity of the switched user terminal cannot be guaranteed.

That is to say, during the handover involving PDCP change and the conversion from PTP to PTM, for the same data, the count value of the source PDCP may be inconsistent with the count value of the target PDCP due to various reasons, resulting in unguaranteed service continuity.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

Embodiments of the present application provide a transmission method and device to ensure service continuity.

The method and the device are conceived based on the same application. Since the principles of the method and the device for solving problems are similar, the implementation of the device and the method can be referred to each other, and repeated descriptions will not be repeated here.

Please refer to FIG. 2. FIG. 2 is a schematic flowchart of a transmission method according to Embodiment 1 of the present disclosure. The method is applied to a first radio access network element and includes the following steps:

Step 201: The first radio access network element sends first information to the terminal, where the first information is used to indicate the difference between the PDCP count value of the first bearer of the terminal and the PDCP count value of the second bearer. The corresponding relationship, or the corresponding relationship between the PDCP sequence number of the first bearer and the PDCP sequence number of the second bearer of the terminal.

Specifically, the first information may be used to indicate the correspondence between the PDCP count value of the first bearer of the terminal and the PDCP count value of the second bearer, and may also be used to indicate the first bearer of the terminal. The corresponding relationship between the PDCP sequence number of the second bearer and the PDCP sequence number of the second bearer.

The embodiments of the present disclosure may be applied to downlink data transmission, for example, a switching process in which a downlink data transmission mode is converted from a point-to-point (Point to Point, PTP) mode to a point-to-multipoint (Point to Multipoint, PTM) mode, and/or, downlink data The transmission involves changing the handover process of the network element where the PDCP is located, so as to realize the continuity of downlink data transmission.

Downlink data transmission involves changing the scene of the network element where the PDCP is located, such as the scene of handover between different gNB-CU-UPs within the gNB, and the handover between different gNBs.

The first radio access network element may be a PDCP instance, a gNB-CU-UP, or a base station, which may be specifically determined according to an actual application scenario. The first radio access network element may be the PDCP instance before the handover, the gNB-CU-UP before the handover, the base station before the handover, the gNB-CU-UP after the handover, or the gNB-CU-UP after the handover. The latter base station can be specifically determined according to the actual application scenario. The radio access network element before the handover can be called the old radio access network element or the source radio access network element, and the radio access network element after the handover can be called the new radio access network element or the source radio access network element. The target radio access network element.

The first information may be carried by an RRC reconfiguration message, or may be carried by a PDCP control protocol data unit (Protocol Data Unit, PDU), or the like.

An embodiment of the present disclosure provides a solution for realizing continuous transmission of downlink data. In the process of changing service data from being sent via an old radio bearer to being sent via a new radio bearer, the network side informs the user terminal of the PDCP count of the old and new bearers. The correspondence between values (or serial numbers), so that business continuity can be guaranteed.

Specifically, in the process of switching involving PDCP change and converting the downlink data transmission mode from PTP mode to PTM mode, even if the count value of the source PDCP is inconsistent with the count value of the target PDCP, the continuous transmission of service data can be guaranteed. , and then solve the problem that the continuity of multicast services cannot be guaranteed in the scenario where each gNB can independently determine the mapping relationship between multicast data streams and radio bearers according to the principles of 5G networks.

The above-mentioned transmission method is exemplified below.

The source radio bearer is the radio bearer before the handover, or the old radio bearer, the target radio bearer is the radio bearer after the handover or the new radio bearer, and the temporary radio bearer is the target radio access network network of the handover. The radio bearer established by the element for receiving the data forwarded by the source radio access network element.

In an optional specific implementation manner, the first information includes an offset between the PDCP count values of the first bearer and the second bearer or includes the first bearer and the second bearer Offset between PDCP sequence numbers of bearers.

In another optional specific implementation manner, the first information includes second information and third information, and the second information is a count value or a sequence number of the first PDCP data packet in the first bearer, The third information is the count value or sequence number of the second PDCP data packet in the second bearer; the first PDCP data packet is the data packet in the first bearer that is terminated for reception, and the second PDCP data packet The data packet is the data packet that starts to be received in the second bearer;

The first radio access network element releases the first bearer.

Wherein, the first bearer may be a temporary bearer.

In an optional specific implementation manner, before the first radio access network element sends the first information to the terminal, the method further includes:

In other optional specific implementation manners, the fifth information may not include the count value or sequence number of the first PDCP data packet in the first bearer, and may indicate implicitly, for example, the first radio access network When the network element receives the second flag sent by the second radio access network network element, it may be implicitly the count value or sequence number of the last pre-transmitted PDCP data packet on the first bearer.

Optionally, the method further includes:

In another optional specific implementation manner, before the step of sending the first information to the terminal by the first radio access network element, the method further includes:

Wherein, the network element of the second radio access network may acquire the corresponding relationship through prior information. For example, a certain PDCP data PDU sent by the radio bearer corresponding to the first radio access network element previously obtained by the second radio access network element is equivalent to that of the radio bearer corresponding to the second radio access network element. Which PDCP data PDU was sent.

Please refer to FIG. 3. FIG. 3 is a schematic flowchart of a transmission method according to Embodiment 2 of the present disclosure. The method is applied to a terminal and includes the following steps:

Step 301: The terminal receives the first information sent by the first radio access network element, where the first information is used to indicate the difference between the PDCP count value of the first bearer of the terminal and the PDCP count value of the second bearer or is used to indicate the correspondence between the PDCP sequence number of the first bearer of the terminal and the PDCP sequence number of the second bearer.

Optionally, the method further includes:

or,

The terminal releases the first bearer.

The embodiments of the present disclosure provide technical solutions corresponding to the first embodiment, having the same inventive concept, and achieving the same technical effects. For details, please refer to the first embodiment, which will not be repeated here.

Please refer to FIG. 4. FIG. 4 is a schematic flowchart of a transmission method provided in Embodiment 3 of the present disclosure. The method is applied to a user plane function module in a core network, and includes the following steps:

Step 401: the user plane function module receives seventh information sent by the session management function module in the core network; wherein the seventh information is used to indicate that the downlink transmission address for the terminal is changed from the first address to the second address ;

Step 402: Send an end marker for the terminal and for the first service data to the access network element corresponding to the first address, and send an end marker for the terminal to the access network element corresponding to the second address And for the start tag of the first service data.

In the embodiment of the present disclosure, an end marker for the terminal and for the first service data is sent to the access network element corresponding to the address before the handover, and an end marker for the first service data is sent to the access network element corresponding to the address after the handover. The terminal also marks the start of the same service data, so that the network side can obtain the correspondence between PDCP count values or sequence numbers before and after handover, and notify the terminal, thereby ensuring service continuity.

The following examples illustrate the technical solutions provided by the present application.

Example 1. In the scenario where the downlink data transmission mode is converted from PTP mode to PTM mode, the user plane approach is as follows:

Step 1: The user terminal is connected to the 5G network through a gNB, and receives service data in the form of PTP through the gNB.

Step 2: At a certain moment, the gNB decides to send the service to the user terminal by means of PTM. The gNB sends an RRC reconfiguration message to the user terminal, which includes SDAP and PDCP configuration information, including instructions to instruct the user terminal to release the old radio bearers that receive some service flows in the PTP manner, and establish new, The indication of the radio bearer of the same traffic flow is received in the manner of PTM.

Step 3: After receiving the RRC reconfiguration message, the user terminal learns through the SDAP and PDCP configuration information that this RRC reconfiguration message involves changing some service flows from receiving via the old PTP radio bearer to via the new one. PTM radio bearer reception. The user terminal establishes a new PTM radio bearer immediately, but does not immediately release the old PTP radio bearer for the sake of service continuity.

Step 4: After completing the establishment of the new PTM radio bearer, the user terminal feeds back an RRC reconfiguration complete message to the gNB.

Step 5: After the gNB receives the RRC reconfiguration complete message sent by the user terminal, the PDCP instance corresponding to its old PTP radio bearer (that is, the first radio access network element) sends a PDCP to the user terminal. Control Protocol Data Unit (PDU), which contains:

An offset value (that is, the offset between the PDCP count value (or sequence number) of the first bearer and the second bearer) to inform the user terminal of the data sent by the old PTP radio bearer. The PDCP data PDU corresponds to which PDCP data PDU is sent through the new PTM radio bearer. or

Two thresholds Xa (that is, the count value or sequence number of the first PDCP data packet in the first bearer) and Xb (the count value or sequence number of the second PDCP data packet in the second bearer), using To inform the user terminal which PDCP data PDU up to which PDCP count value it should receive through the old PTP radio bearer, and to inform the user terminal which PDCP data PDU starting from which PDCP count value it should receive through the new PTM radio bearer .

Step 6: After receiving the PDCP control PDU, the user terminal performs subsequent processing according to the content in the PDCP control PDU to ensure service continuity.

Specifically, if the above-mentioned PDCP control PDU contains the offset value, the user terminal can perform subsequent processing in the following manner:

For all PDCP data packets received through the old radio bearer or through the temporary radio bearer, including buffered and subsequently received, as long as they have not been submitted to the SDAP layer or higher layers, operations such as decryption and integrity protection verification are completed. After that, perform a bias operation on its count value as follows:

It is assumed that the count value of the PDCP data packet that needs to perform the bias operation is Y before the operation. If the offset value is sent in the format of Xa-Xb, modify the count value of the data packet to Y-(Xa-Xb) (modulo operation may be required, and the same will not be repeated in the following text); If the offset value is sent in the format of Xb-Xa, then modify the count value of the data packet to Y+(Xb-Xa).

Then, the data received through the two radio bearers are combined together and sorted according to the order of increasing count values. In the event of a duplicate, data received later in time is discarded. This also means that if the user terminal has successfully received a PDCP data packet through the old radio bearer or through the temporary radio bearer, it successfully receives it through the new radio bearer (transmitted in the way of PTM). If the user terminal has successfully received a PDCP data packet through the new radio bearer (transmitted in the way of PTM), the user terminal will pass the old radio bearer again. , or the PDCP packet with the same content is successfully received through the temporary radio bearer, and the latter is discarded.

Finally, the sorted data are submitted to the SDAP layer or higher layers in turn.

Optionally, the user terminal may also request network retransmission according to the sorted data. That is, if the user terminal finds that the counted values are discontinuous in the sorted data, it can notify the network through PDCP status report, etc., to request retransmission of these data packets.

If the above-mentioned PDCP control PDU contains the thresholds Xa and Xb, then the user terminal can perform subsequent processing in the following manner:

For all PDCP data packets received through the old radio bearer or through the temporary radio bearer, including buffered and subsequently received, if the count value is not lower than Xa, discard them; If the count value of all PDCP data packets received by the radio bearer is lower than Xb, it will be discarded. or,

For all PDCP data packets received through the old radio bearer or through the temporary radio bearer, including buffered and subsequently received, if the count value is higher than Xa, discard them; If the count value of all PDCP data packets received by the radio bearer is not higher than Xb, it will be discarded.

Then, when the user terminal submits data to the SDAP layer or higher layers, it first submits the data received through the old radio bearer or through the temporary radio bearer; after it is determined that the transmission is completed, it submits the data through the new (with PTM) data received by the radio bearer.

Example 2. In the scenario where the downlink data transmission mode is converted from PTP mode to PTM mode, the control plane approach:

Step 2: At a certain moment, the gNB decides to send the service to the user terminal by means of PTM. The gNB (that is, the first radio access network element) sends an RRC reconfiguration message to the user terminal, which includes SDAP and PDCP configuration information, including instructing the user terminal to release the old ones and receive some services in the way of PTP. The indication of the radio bearer of the flow, and the indication of the establishment of a new radio bearer that receives the same service flow in the PTM manner.

This RRC reconfiguration message also includes:

Two thresholds Xa (the count value or sequence number of the first PDCP data packet in the first bearer) and Xb (the count value or sequence number of the second PDCP data packet in the second bearer) to inform The user terminal should receive the PDCP data PDU up to which PDCP count value through the old PTP radio bearer, and inform the user terminal from which PDCP count value it should receive the PDCP data PDU through the new PTM radio bearer.

That is, the first information used to indicate the correspondence between the PDCP count values (or sequence numbers) of the first bearer of the terminal and the second bearer may be carried by the RRC reconfiguration message.

Step 3: After the user terminal receives this RRC reconfiguration message, it first establishes a new PTM radio bearer, and then performs subsequent processing according to the content carried in the RRC reconfiguration message to ensure service continuity. For details, please refer to the above example 1, It will not be repeated here.

Example 3, please refer to Figure 5, the scenario of handover between different gNB-CU-UPs within the gNB, the user plane approach:

Step 1: The user terminal 1 is connected to the 5G network through a gNB, and receives service data belonging to a certain session through the gNB. In the 5G core network, this session service is distributed by a UPF. The gNB contains one gNB-CU-CP and multiple gNB-CU-UPs, and the user terminal 1 receives the service data belonging to the session sent by the UPF through the gNB-CU-UP1. At the same time, some other user terminals are receiving the service data belonging to the session sent by the UPF through the gNB-CU-UP2. Due to the large number of the latter, in order to save air interface resources, gNB-CU-UP2 establishes a shared bearer for those user terminals, and transmits the above service data over the air interface in a PTM manner. The mapping relationship between the service flow and the radio bearer executed by the two gNB-CU-UPs is the same except for the radio bearer identification. For example, gNB-CU-UP1 maps service flow 1 in the session to radio bearer 1, and maps service flows 2 and 3 to radio bearer 2; gNB-CU-UP2 maps service flow 1 in this session to radio bearer 2 Bearer 5, and the service flows 2 and 3 are mapped to the radio bearer 6, this situation belongs to "the mapping relationship between the service flows executed by the two gNB-CU-UPs to the radio bearers is the same except for the radio bearer identification. the" situation.

Step 2: Due to reasons such as the movement of the user terminal 1, the gNB-CU-CP decides to change the service data transmission path for the user terminal 1 from gNB-CU-UP1 to gNB-CU-UP2. Therefore, gNB-CU-CP performs a series of control plane signaling interactions with user terminal 1, gNB-CU-UP1, gNB-CU-UP2, one or more gNB-DUs, AMF and SMF to complete the above path change .

Step 3: The SMF sends a signaling to the UPF to inform it that the downlink address for the session and for the user terminal 1 has changed, generally speaking, from gNB-CU-UP1 to gNB-CU-UP2. However, there are also other UPFs between the UPF and the gNB-CU-UP1 or gNB-CU-UP2. In this case, the downlink transmission address of the N9 transmission channel is changed.

Steps 4a and 4b: UPF sends an end marker for user terminal 1 to gNB-CU-UP1, which is attached to a certain data packet; UPF sends gNB-CU-UP2 (ie, the first radio access network element) to A start marker (ie, the first marker) for the user terminal 1 is attached to a certain data packet. The contents of the two packets are the same. Since packets on the N3 transmission channel are almost always transmitted in sequence, this means that for any packet sent to gNB-CU-UP1 earlier than the above end marker, its content must not be included in any later In the data packet sent to gNB-CU-UP2 in the above start marker.

Steps 5a and 5b: gNB-CU-UP1 and gNB-CU-UP2 respectively assign PDCP count values to each downlink data packet according to the mapping relationship between service flow and radio bearer, and generate corresponding PDCP data packets. . After receiving the end marker and start marker described in steps 4a and 4b, they calculate the count value for each service bearer by themselves. The count value of the bearer is denoted as Xa (that is, the count value or sequence number of the first PDCP data packet in the first bearer), and the calculated value of the gNB-CU-UP2 is calculated for the corresponding (that is, contains the same service flow) The count value of the radio bearer is Xb (the count value or sequence number of the second PDCP data packet in the second bearer), and the two satisfy any one of the following two relationships:

1) For the PDCP data packet generated by gNB-CU-UP1 (that is, the first radio access network element), if and only if its count value is lower than Xa, the service data contained in it is the one before the end marker. Received, and for the PDCP data packet generated by the gNB-CU-UP2, if and only if its count value is lower than Xb, the service data contained in it is received before the start marker;

2) For the PDCP data packet generated by gNB-CU-UP1, if and only if its count value is not higher than Xa, the service data contained in it is received before the end marker, and for gNB-CU-UP2 The generated PDCP data packet, if and only if its count value is not higher than Xb, contains service data that is received before the start marker.

Steps 6a, 6b: Both gNB-CU-UP1 and gNB-CU-UP2 send service data through the air interface. Since the terminal 1 has established a connection with the gNB-CU-UP2 in the second step, it can already receive the service data belonging to the above-mentioned session sent by the gNB-CU-UP2 in the form of multicast.

Step 7: For each radio bearer, gNB-CU-UP1 (that is, the second radio access network element) sends an end marker to gNB-CU-UP2 (that is, the first radio access network element) (that is, the second mark), which contains the Xa of the radio bearer (that is, the count value or sequence number of the first PDCP data packet in the first bearer).

Step 8: gNB-CU-UP2 (ie, the first radio access network element) calculates the correspondence between the PDCP data packets of the bearer before the path change and the bearer after the path change by comparing Xa and Xb. That is, gNB-CU-UP2 can know that the content contained in the PDCP data packet with the count value Xa before the path change is equivalent to the content contained in the PDCP data packet with the count value Xb after the path change, and the gNB-CU-UP2 can It is known that the content of the PDCP data packet whose count value is Xa-1 before the path change (the modulo operation may be required, and the same will not be repeated in the following text) is equivalent to the content of the PDCP data packet whose count value is Xb-1 after the path change. included, etc.

Step 9: gNB-CU-UP2 (ie the first radio access network element) sends a PDCP control PDU to user terminal 1, which includes:

An offset value (that is, the offset between the PDCP count value (or sequence number) of the first bearer and the second bearer), such as Xa-Xb, or equivalently, Xb-Xa, with In order to inform the user terminal 1 which PDCP data PDU sent through the old PTP radio bearer corresponds to which PDCP data PDU sent through the new PTM radio bearer. or

Xa and Xb are used to inform the user terminal 1 which PDCP data PDU up to which PDCP count value it should receive through the old PTP radio bearer, and to inform the user terminal from which PDCP count value it should receive through the new PTM radio bearer Beginning of the PDCP data PDU.

Step 10: After receiving the PDCP control PDU, the user terminal performs subsequent processing according to the content in the PDCP control PDU to ensure service continuity. Please refer to the above example 1 for the specific processing process, which will not be repeated here.

Example 4, please refer to Figure 6, the scenario of handover between different gNB-CU-UP within gNB, user plane approach, with temporary bearer:

Step 1: The user terminal 1 is connected to the 5G network through a gNB, and receives service data belonging to a certain session through the gNB. In the 5G core network, this session service is distributed by a UPF. The gNB contains one gNB-CU-CP and multiple gNB-CU-UPs, and the user terminal 1 receives the service data belonging to the session sent by the UPF through the gNB-CU-UP1. At the same time, some other user terminals are receiving service data belonging to the session sent by the UPF through the gNB-CU-UP2. Due to the large number of the latter, in order to save air interface resources, gNB-CU-UP2 establishes a shared bearer for those user terminals, and transmits the above service data over the air interface in a PTM manner. The mapping relationship between the service flow and the radio bearer executed by the two gNB-CU-UPs is the same except for the radio bearer identifier. For example, gNB-CU-UP1 maps service flow 1 in the session to radio bearer 1, and maps service flows 2 and 3 to radio bearer 2; gNB-CU-UP2 maps service flow 1 in this session to radio bearer 2 Bearer 5, and the service flows 2 and 3 are mapped to the radio bearer 6, this situation belongs to "the mapping relationship between the service flows executed by the two gNB-CU-UPs to the radio bearers is the same except for the radio bearer identification. ' situation.

Step 2: Due to reasons such as the movement of the user terminal 1, the gNB-CU-CP decides to change the service data transmission path for the user terminal 1 from gNB-CU-UP1 to gNB-CU-UP2. Therefore, gNB-CU-CP performs a series of control plane signaling interactions with user terminal 1, gNB-CU-UP1, gNB-CU-UP2, one or more gNB-DUs, AMF and SMF to complete the above path change . Due to hardware limitations, the user terminal 1 can only be connected to one of the gNB-CU-UP1 and the gNB-CU-UP2 at the same time. In order to ensure business continuity, gNB-CU-CP decides to enable the data forwarding mechanism. Specifically, it sends an interface message to gNB-CU-UP2, requesting it to establish a corresponding temporary radio bearer for user terminal 1 and for each radio bearer that user terminal 1 is receiving before the path change in the session, It is used to send the service data forwarded from the gNB-CU-UP1 to the user terminal 1 in a PTP manner. gNB-CU-UP2 accepts the above request and assigns a transport layer address to each of the above radio bearers.

Step 3: For each of the above-mentioned radio bearers, gNB-CU-UP1 starts to forward the above-mentioned service data to gNB-CU-UP2 through the above-mentioned transport layer address.

Step 4: The SMF sends a signaling to the UPF to inform it that the downlink address for the session and for the user terminal 1 has changed, generally speaking, from gNB-CU-UP1 to gNB-CU-UP2. However, there are also other UPFs between the UPF and the gNB-CU-UP1 or gNB-CU-UP2. In this case, the downlink transmission address of the N9 transmission channel is changed.

Steps 5a, 5b: UPF sends an end marker for user terminal 1 to gNB-CU-UP1, which is attached to a certain data packet; UPF sends gNB-CU-UP2 (ie, the first radio access network element) to A start marker (ie, the first marker) for the user terminal 1 is attached to a certain data packet. The contents of these two packets are the same. Since packets on the N3 transmission channel are almost always transmitted in sequence, this means that for any packet sent to gNB-CU-UP1 earlier than the above end marker, its content must not be included in any later In the data packet sent to gNB-CU-UP2 in the above start marker.

Steps 6a and 6b: gNB-CU-UP1 and gNB-CU-UP2 respectively assign PDCP count values to each downlink data packet according to the mapping relationship between service flow and radio bearer, and generate corresponding PDCP data packets. . gNB-CU-UP1 forwards to gNB-CU-UP2 (that is, the first radio access network element) according to the description in step 3, forwards each downlink data packet that the user terminal 1 needs to receive, which contains a PDCP count value that reflects Information.

Step 7: For each of the above-mentioned radio bearers, after gNB-CU-UP1 has sent to gNB-CU-UP2 all packets mapped to the radio bearer received earlier than step 5a, gNB-CU-UP1 ( That is, the second radio access network element) sends an end marker (that is, the second marker) to the gNB-CU-UP2 (that is, the first radio access network element) to indicate that the user terminal 1 and the radio bearer Data forwarding has been completed. This end marker implicitly refers to the count value of the last forwarded PDCP data packet on the radio bearer, or equivalently, the count value +1.

Steps 8a and 8b: gNB-CU-UP2 sends the above service data through the air interface. Among them, the data forwarded from gNB-CU-UP1 is sent in the way of PTP through the corresponding temporary radio bearer, and the data directly received from the UPF is sent in the way of PTM through the shared bearer described in step 1. . Optionally, after the data forwarded from gNB-CU-UP1 has been successfully received by user terminal 1, gNB-CU-UP2 releases the temporary radio bearer.

Step 9: After receiving the end marker and start marker described in steps 7 and 5b, gNB-CU-UP2 calculates the count value for each service bearer by itself. The count value of the radio bearer that the terminal 1 sends data in the form of PTP is denoted as Xa, and the count value of the radio bearer that sends data in the form of PTM for the corresponding (that is, containing the same service flow) is Xb, both of which satisfy the following two: any of the relationships:

1) For the PDCP data packet forwarded from gNB-CU-UP1, if and only if its count value is lower than Xa, the service data it contains is received prior to the end marker for the bearer, and For the PDCP data packet self-generated by gNB-CU-UP2 according to the description of step 6b, if and only if its count value is lower than Xb, the service data contained in it is received before the start marker;

2) For the PDCP data packet forwarded from gNB-CU-UP1, if and only if its count value is not higher than Xa, the service data contained in it is received prior to the end marker for the bearer, And for the PDCP data packet generated by gNB-CU-UP2 according to the description of step 6b, if and only if its count value is not higher than Xb, the service data contained in it is received before the start marker.

The gNB-CU-UP2 (ie, the first radio access network element) calculates the correspondence between the PDCP data packets of the bearer before the path change and the bearer after the path change by comparing Xa and Xb. That is, gNB-CU-UP2 can know that the content contained in the PDCP data packet with the count value Xa before the path change is equivalent to the content contained in the PDCP data packet with the count value Xb after the path change, and the gNB-CU-UP2 can It is known that the content of the PDCP data packet whose count value is Xa-1 before the path change (the modulo operation may be required, and the same will not be repeated in the following text) is equivalent to the content of the PDCP data packet whose count value is Xb-1 after the path change. included, etc.

Step 10: gNB-CU-UP2 (ie, the first radio access network element) sends a PDCP control PDU to user terminal 1, which includes:

An offset value (that is, the offset between the PDCP count value (or sequence number) of the first bearer and the second bearer), such as Xa-Xb, or equivalently, Xb-Xa, with In order to inform the user terminal 1 which PDCP data PDU sent through the temporary PTP radio bearer corresponds to which PDCP data PDU sent through the shared PTM radio bearer. or

Xa and Xb are used to inform the user terminal 1 which PDCP data PDU up to which PDCP count value it should receive through the temporary PTP radio bearer, and to inform the user terminal from which PDCP count value it should receive through the shared PTM radio bearer Beginning of the PDCP data PDU.

Step 11: After receiving the PDCP control PDU, the user terminal performs subsequent processing according to the content in the PDCP control PDU to ensure service continuity. For the specific processing process, please refer to the above Example 1, which will not be repeated here. Optionally, after the processing is completed, the user terminal 1 releases the temporary radio bearer mentioned above.

Example 5, handover between different gNBs, control plane approach:

Step 1: Both gNB1 and gNB2 are transmitting service data in the manner of PTM, and the mapping relationship between the service flow of the two and the radio bearer is the same except for the radio bearer identifier. For example, gNB1 maps service flow 1 in the session to radio bearer 1, and maps service flows 2 and 3 to radio bearer 2; gNB2 maps service flow 1 in the session to radio bearer 5, and maps service flow 2 to radio bearer 2 , 3 are mapped to the radio bearer 6, and this situation belongs to the situation of "the mapping relationship between the service flows performed by the two gNBs to the radio bearer is the same except for the radio bearer identifier".

Step 2: gNB1 (that is, the first radio access network element) sends an interface message to gNB2, which includes an indication (that is, sixth information) for each of the above-mentioned radio bearers, the content of which is the content of the PDCP data packet. That is, the content in which PDCP data packet transmitted by gNB1 corresponds to the content in which PDCP data packet transmitted by gNB2.

Step 3: The user terminal is connected to the 5G network through a gNB1, and receives the above service data through the gNB1.

Step 4: Due to reasons such as the movement of the user terminal 1, gNB1 decides to switch the user terminal to gNB2.

Step 5: gNB2 sends an RRC reconfiguration message to the user terminal, which includes the configuration information after handover. This RRC reconfiguration message is forwarded to the user terminal via gNB1.

This RRC reconfiguration message also includes an indication (ie, the first information) generated according to the correspondence between the PDCP data packets received in step 2, and its specific content is:

An offset value (that is, the offset between the PDCP count value (or sequence number) of the first bearer and the second bearer) to inform the user terminal of the PDCP sent by the radio bearer before handover The data PDU corresponds to which PDCP data PDU sent by the radio bearer before handover. or

Two thresholds Xa (that is, the count value or sequence number of the first PDCP data packet in the first bearer) and Xb (the count value or sequence number of the second PDCP data packet in the second bearer), using To inform the user terminal which PDCP data PDU up to which PDCP count value it should receive through the pre-handover radio bearer, and to inform the user terminal which PDCP data PDU it should receive through the pre-handover radio bearer starting from which PDCP count value .

Step 6: The user terminal performs handover after receiving the RRC reconfiguration message, and then performs subsequent processing according to the content carried in the RRC reconfiguration message to ensure service continuity. For details, refer to the above example 1, which will not be repeated here.

Example 6, see Figure 7, Handover between different gNBs, user plane approach.

Step 1: User terminal 1 is connected to the 5G network through a gNB1, and receives service data belonging to a certain session. In the 5G core network, the service is distributed by a UPF. At the same time, some other user terminals are receiving service data belonging to the session sent by the UPF through gNB2. Due to the large number of the latter, in order to save air interface resources, gNB2 establishes a shared bearer for those user terminals, and sends the above-mentioned service data over the air interface in a PTM manner. The mapping relationship between the service flow and the radio bearer executed by the two gNBs is the same except for the radio bearer identifier. For example, gNB1 maps service flow 1 in the session to radio bearer 1, and maps service flows 2 and 3 to radio bearer 2; gNB2 maps service flow 1 in the session to radio bearer 5, and maps service flow 2 to radio bearer 2 , 3 are mapped to the radio bearer 6, and this situation belongs to the situation of "the mapping relationship between the service flows performed by the two gNBs to the radio bearer is the same except for the radio bearer identifier".

Step 2: Due to reasons such as the movement of the user terminal 1, the gNB1 decides to switch the user terminal 1 to the gNB2. Therefore, gNB1 performs a series of control plane signaling interactions with user terminal 1, gNB2, AMF and SMF to complete the above handover process.

Step 3: The SMF sends a signaling to the UPF to inform it that the downlink address for the session and for the user terminal 1 has changed, generally speaking, from gNB1 to gNB2. However, there are also other UPFs that exist between the UPF and gNB1 or gNB2. In this case, the downlink transmission address of the N9 transmission channel is changed.

Steps 4a and 4b: UPF sends an end marker for user terminal 1 to gNB1, which is attached to a data packet; UPF sends a start marker for user terminal 1 to gNB2 (ie, the first radio access network element). A marker (ie, the first marker), attached to a data packet. The contents of the two packets are the same. Since packets on the N3 transmission channel are almost always transmitted in sequence, this means that for any packet sent to gNB1 earlier than the above end marker, its content must not be included in any packet after the above start marker. In the data packet sent to gNB2.

Steps 5a and 5b: gNB1 and gNB2 respectively assign PDCP count values to each downlink data packet according to the mapping relationship between the service flow and the radio bearer, and generate corresponding PDCP data packets. After receiving the end marker and start marker described in steps 4a and 4b, they calculate the count value for each service bearer by themselves. Here, the count value for a certain radio bearer calculated by gNB1 may be used. Denoted as Xa, the count value of the corresponding radio bearer (that is, containing the same service flow) calculated by gNB2 is Xb, and the two satisfy any one of the following two relations:

1) For the PDCP data packet generated by gNB1, if and only if its count value is lower than Xa, the service data contained in it is received before the end marker, and for the PDCP data packet generated by gNB2, if and Only when its count value is lower than Xb, the service data contained in it is received before the start marker;

2) For the PDCP data packet generated by gNB1, if and only if its count value is not higher than Xa, the service data contained in it is received before the end marker, and for the PDCP data packet generated by gNB2, when And only when its count value is not higher than Xb, the service data contained in it is received before the start tag.

Steps 6a, 6b: Both gNB1 and gNB2 send service data through the air interface. Since the terminal 1 has established a connection with the gNB2 in the second step, it can already receive the service data belonging to the above-mentioned session sent by the gNB2 in the form of multicast.

Step 7: For each radio bearer, gNB1 (ie, the second radio access network element) sends an end marker to gNB2 (ie, the first radio access network element), which includes Xa of the radio bearer.

Step 8: The gNB2 calculates the correspondence between the bearer before the path change and the PDCP data packet of the bearer after the path change by comparing Xa and Xb. That is, gNB2 can know that the content contained in the PDCP data packet with the count value Xa before the path change is equivalent to the content contained in the PDCP data packet with the count value Xb after the path change, and gNB2 can know that the count value before the path change is The content contained in the PDCP data packet of Xa-1 (the modulo operation may be required, and the same will not be repeated hereinafter) is equivalent to the content contained in the PDCP data packet whose count value is Xb-1 after the path is changed, and so on.

Step 9: gNB2 sends a PDCP control PDU (Protocol Data Unit) to user terminal 1, which contains:

An offset value (ie, the offset between the PDCP count value (or sequence number) of the first bearer and the second bearer), such as Xa-Xb, or equivalently, Xb-Xa, to Inform the user terminal 1 which PDCP data PDU sent through the new PTM radio bearer corresponds to the PDCP data PDU sent through the old PTP radio bearer. or

Xa (that is, the count value or sequence number of the first PDCP data packet in the first bearer) and Xb (that is, the count value or sequence number of the second PDCP data packet in the second bearer) are used to inform the user Terminal 1 should receive the PDCP data PDU up to which PDCP count value through the old PTP radio bearer, and inform the user terminal from which PDCP count value it should receive through the new PTM radio bearer.

Step 10: After receiving the PDCP control PDU, the user terminal 1 performs subsequent processing according to the content in the PDCP control PDU to ensure service continuity. For the specific processing process, please refer to the above Example 1, which will not be repeated here.

Example 7, please refer to Figure 8, handover between different gNBs, user plane approach, with temporary bearer.

Step 1: The user terminal 1 is connected to the 5G network through a gNB1, and receives service data belonging to a certain session. In the 5G core network, the service is distributed by a UPF. At the same time, some other user terminals are receiving service data belonging to the session sent by the UPF through gNB2. Due to the large number of the latter, in order to save air interface resources, gNB2 establishes a shared bearer for those user terminals, and sends the above-mentioned service data over the air interface in a PTM manner. The mapping relationship between the service flow and the radio bearer executed by the two gNBs is the same except for the radio bearer identifier. For example, gNB1 maps service flow 1 in the session to radio bearer 1, and maps service flows 2 and 3 to radio bearer 2; gNB2 maps service flow 1 in the session to radio bearer 5, and maps service flow 2 to radio bearer 2 , 3 are mapped to the radio bearer 6, and this situation belongs to the situation of "the mapping relationship between the service flows performed by the two gNBs to the radio bearer is the same except for the radio bearer identifier".

Step 2: Due to reasons such as the movement of the user terminal 1, the gNB1 decides to switch the user terminal 1 to the gNB2. Therefore, gNB1 performs a series of control plane signaling interactions with user terminal 1, gNB2, AMF and SMF to complete the above handover process. Due to hardware limitations, user terminal 1 can only be connected to one of gNB1 and gNB2 at the same time. In order to ensure business continuity, gNB1 and gNB2 unanimously decided to enable the data forwarding mechanism. Specifically, for the user terminal 1, gNB2 allocates a transport layer address for each radio bearer that the user terminal 1 is receiving before handover in the session to receive the service data forwarded by gNB1; For each of the above radio bearers, a corresponding temporary radio bearer is established for sending the service data forwarded by the gNB1 to the user terminal 1 in a PTP manner.

Step 3: For each of the above-mentioned radio bearers, gNB1 starts to forward the above-mentioned service data to gNB2 through the above-mentioned transport layer address.

Step 4: The SMF sends a signaling to the UPF to inform it that the downlink address for the session and for the user terminal 1 has changed, generally speaking, from gNB1 to gNB2. However, there is also a situation in which other UPFs exist between the UPF and gNB1 or gNB2, and what is changed at this time is the downlink transmission address of the N9 transmission channel.

Steps 5a and 5b: UPF sends an end marker for user terminal 1 to gNB1, which is attached to a certain data packet; UPF sends a start marker for user terminal 1 to gNB2 (ie, the first radio access network element). A marker (ie, the first marker), attached to a data packet. The contents of the two packets are the same. Since packets on the N3 transmission channel are almost always transmitted in sequence, this means that for any packet sent to gNB1 earlier than the above end marker, its content must not be included in any packet after the above start marker. In the data packet sent to gNB2.

Steps 6a, 6b: gNB1 and gNB2 assign PDCP count values to each downlink data packet in turn according to the mapping relationship between service flow and radio bearer, and generate corresponding PDCP data packets. According to the description of step 3, gNB1 forwards each downlink data packet that needs to be received by user terminal 1 to gNB2, which contains information reflecting the PDCP count value.

Step 7: For each of the above radio bearers, after gNB1 has sent to gNB2 all the data packets mapped to the radio bearer received earlier than step 5a, gNB1 (ie, the second radio access network element) sends gNB2 (ie, the first radio access network element) sends an end marker (ie, a second marker) to indicate that the data forwarding for the user terminal 1 and for the radio bearer has been completed. This end marker implicitly refers to the count value of the last forwarded PDCP data packet on the radio bearer, or equivalently, the count value +1.

Steps 8a and 8b: gNB2 sends the above service data through the air interface. Wherein, the data forwarded from gNB1 is sent in the way of PTP through the corresponding temporary radio bearer, and the data directly received from the UPF is sent in the way of PTM through the shared bearer described in step 1. Optionally, after the data forwarded from gNB1 has been successfully received by user terminal 1, gNB2 releases the temporary radio bearer.

Step 9: After receiving the end marker and start marker described in steps 7 and 5b, gNB2 calculates the count value for each service bearer by itself. The count value of the radio bearer that sends data in the form of Xa is denoted as Xa, and the count value of the radio bearer that sends data in the form of PTM for the corresponding (that is, containing the same service flow) is Xb, and the two satisfy the following two relations. any of:

1) For the PDCP data packet forwarded from gNB1, if and only if its count value is lower than Xa, the service data contained in it is received prior to the end marker for the bearer, and for gNB2 according to the steps The PDCP data packet generated by the description of 6b, if and only if its count value is lower than Xb, the service data contained in it is received before the start mark;

2) For the PDCP data packet forwarded from gNB1, if and only if its count value is not higher than Xa, the service data contained in it is received prior to the end marker for the bearer, and for gNB2 according to The self-generated PDCP data packet described in step 6b, if and only if its count value is not higher than Xb, contains service data that is received prior to the start tag.

The gNB2 calculates the correspondence between the PDCP data packets of the bearer before the path change and the bearer after the path change by comparing Xa and Xb. That is, gNB2 can know that the content contained in the PDCP data packet with the count value Xa before the path change is equivalent to the content contained in the PDCP data packet with the count value Xb after the path change, and gNB2 can know that the count value before the path change is The content contained in the PDCP data packet of Xa-1 (the modulo operation may be required, and the same will not be repeated hereinafter) is equivalent to the content contained in the PDCP data packet whose count value is Xb-1 after the path is changed, and so on.

Step 10: gNB-CU-UP2 sends a PDCP control PDU to user terminal 1, which includes:

An offset value (ie, the offset between the PDCP count value (or sequence number) of the first bearer and the second bearer), such as Xa-Xb, or equivalently, Xb-Xa, to The user terminal 1 is informed which PDCP data PDU sent through the shared PTM radio bearer corresponds to the PDCP data PDU sent through the temporary PTP radio bearer. or

Xa (that is, the count value or sequence number of the first PDCP data packet in the first bearer) and Xb (that is, the count value or sequence number of the second PDCP data packet in the second bearer) are used to inform the user The terminal 1 should receive the PDCP data PDU up to which PDCP count value through the temporary PTP radio bearer, and inform the user terminal from which PDCP count value it should receive the PDCP data PDU through the shared PTM radio bearer.

Please refer to FIG. 9. FIG. 9 is a schematic structural diagram of a wireless access network element according to Embodiment 4 of the present disclosure. The wireless access network element includes a memory 910, a transceiver 920, and a processor 930:

The memory 910 is used to store computer programs; the transceiver 920 is used to send and receive data under the control of the processor; the processor 930 is used to read the computer programs in the memory and perform the following operations:

The transceiver 920 is used for receiving and transmitting data under the control of the processor 930 .

9, the bus architecture may include any number of interconnected buses and bridges, specifically one or more processors represented by processor 930 and various circuits of memory represented by memory 910 are linked together. The bus architecture may also link together various other circuits, such as peripherals, voltage regulators, and power management circuits, which are well known in the art and, therefore, will not be described further herein. The bus interface provides the interface. Transceiver 920 may be multiple elements, ie, including a transmitter and a receiver, providing means for communicating with various other devices over transmission media including wireless channels, wired channels, fiber optic cables, and the like. The processor 930 is responsible for managing the bus architecture and general processing, and the memory 910 may store data used by the processor 930 in performing operations.

The processor 930 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (Field-Programmable Gate Array, FPGA) or a complex programmable logic device (Complex Programmable Logic Device, CPLD), the processor can also use a multi-core architecture.

The service data contained in the first PDCP data packet and the second PDCP data packet are both first service data.

The first bearer is released.

It should be noted here that the above-mentioned wireless access network element provided by the embodiment of the present disclosure can implement all the method steps implemented by the above-mentioned method embodiment applied to the first wireless access network element, and can achieve the same Technical effects, the same parts and beneficial effects in this embodiment as those in the method embodiment will not be described in detail here.

Please refer to FIG. 10. FIG. 10 is a schematic structural diagram of a terminal according to Embodiment 5 of the present disclosure. The terminal includes a memory 1010, a transceiver 1020, and a processor 1030:

The memory 1010 is used to store computer programs; the transceiver 1020 is used to send and receive data under the control of the processor; the processor 1030 is used to read the computer programs in the memory 1010 and perform the following operations:

The transceiver 1020 is used for receiving and transmitting data under the control of the processor 1030 .

10 , the bus architecture may include any number of interconnected buses and bridges, specifically one or more processors represented by the processor 1030 and various circuits of the memory represented by the memory 1010 are linked together. The bus architecture may also link together various other circuits, such as peripherals, voltage regulators, and power management circuits, which are well known in the art and, therefore, will not be described further herein. The bus interface provides the interface. Transceiver 1020 may be a number of elements, including a transmitter and a receiver, providing means for communicating with various other devices over transmission media including wireless channels, wired channels, fiber optic cables, and the like Transmission medium. For different user equipments, the user interface 1040 may also be an interface capable of externally connecting the required equipment, and the connected equipment includes but is not limited to a keypad, a display, a speaker, a microphone, a joystick, and the like.

The processor 1030 is responsible for managing the bus architecture and general processing, and the memory 1010 may store data used by the processor 1030 in performing operations.

Optionally, the processor 1030 may be a CPU (Central Processing Unit), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA) or a Complex Programmable Logic Device (Complex). Programmable Logic Device, CPLD), the processor can also adopt a multi-core architecture.

The processor is configured to execute any one of the methods provided in the embodiments of the present application according to the obtained executable instructions by invoking the computer program stored in the memory. The processor and memory may also be physically separated.

Optionally, the processor 1030 is further configured to perform the following operations:

or,

The first bearer is released.

It should be noted here that the above-mentioned terminal provided by the embodiments of the present disclosure can implement all the method steps implemented by the above-mentioned method embodiments applied to the terminal, and can achieve the same technical effect, and the same technical effect will not be discussed here. The same parts and beneficial effects of the method embodiments will be described in detail.

Please refer to FIG. 11. FIG. 11 is a schematic structural diagram of a user plane function module provided in Embodiment 6 of the present disclosure. The user plane function module is located in the core network. The user plane function module includes a memory 1110, a transceiver 1120, a processing Device 1130:

The memory 1110 is used to store computer programs; the transceiver 1120 is used to send and receive data under the control of the processor; the processor 1130 is used to read the computer programs in the memory and perform the following operations:

The transceiver 1120 is used for receiving and transmitting data under the control of the processor 1130 .

11, the bus architecture may include any number of interconnected buses and bridges, specifically one or more processors represented by processor 1130 and various circuits of memory represented by memory 1110 are linked together. The bus architecture may also link together various other circuits, such as peripherals, voltage regulators, and power management circuits, which are well known in the art and, therefore, will not be described further herein. The bus interface provides the interface. Transceiver 1120 may be a number of elements, including a transmitter and a receiver, that provide means for communicating with various other devices over transmission media including wireless channels, wired channels, fiber optic cables, and the like. The processor 1130 is responsible for managing the bus architecture and general processing, and the memory 1110 may store data used by the processor 1130 in performing operations.

The processor 1130 can be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (Field-Programmable Gate Array, FPGA) or a complex programmable logic device (Complex Programmable Logic Device, CPLD), the processor can also use a multi-core architecture.

It should be noted here that the above-mentioned user plane functional modules provided by the embodiments of the present disclosure can implement all the method steps implemented by the above method embodiments applied to the user plane functional modules in the core network, and can achieve the same technology Therefore, the same parts and beneficial effects in this embodiment as those in the method embodiment will not be described in detail here.

Please refer to FIG. 12. FIG. 12 is a schematic structural diagram of a wireless access network element according to Embodiment 7 of the present disclosure. The wireless access network element 1200 includes:

A first information sending unit 1201, configured to send first information to a terminal, where the first information is used to indicate the correspondence between the PDCP count value of the first bearer of the terminal and the PDCP count value of the second bearer, or It is used to indicate the correspondence between the PDCP sequence number of the first bearer of the terminal and the PDCP sequence number of the second bearer.

Optionally, the radio access network element 1200 further includes:

a releasing unit for releasing the first bearing.

Optionally, the radio access network element 1200 further includes:

a fourth information receiving unit, configured to receive fourth information sent by a user plane function module in the core network, where the fourth information includes a first flag for the first service data;

a fifth information receiving unit, configured to receive fifth information sent by a second radio access network element, where the fifth information includes a second flag for the first service data;

Optionally, the radio access network element 1200 further includes:

A first information determining unit, configured to determine the first information according to the fourth information and the fifth information.

Optionally, the radio access network element 1200 further includes:

The sixth information receiving module is configured to receive sixth information sent by the network element of the second wireless access network, where the sixth information is used to indicate the corresponding relationship.

Please refer to FIG. 13. FIG. 13 is a schematic structural diagram of a terminal according to Embodiment 8 of the present disclosure. The terminal 1300 includes:

The first information receiving unit 1301 is configured to receive the first information sent by the first radio access network element, where the first information is used to indicate the PDCP count value of the first bearer of the terminal and the PDCP count of the second bearer The corresponding relationship between the values, or used to indicate the corresponding relationship between the PDCP sequence number of the first bearer of the terminal and the PDCP sequence number of the second bearer.

Optionally, the terminal 1300 further includes:

A first discarding unit, configured to successfully receive a third PDCP data packet through the first bearer, and successfully receive a fourth PDCP data packet through the second bearer, and the count value of the fourth PDCP data packet or If the sequence number corresponds to the count value or sequence number of the third PDCP data packet, discard the fourth PDCP data packet;

or,

The second discarding unit is configured to successfully receive the fourth PDCP data packet through the second bearer, and successfully receive the third PDCP data packet through the first bearer, and the count value of the third PDCP data packet or If the sequence number corresponds to the count value or sequence number of the fourth PDCP data packet, the third PDCP data packet is discarded.

Optionally, the terminal 1300 further includes:

a third discarding unit, configured to discard the fifth PDCP data packet if its count value or sequence number is greater than or equal to the count value or sequence number in the first PDCP data packet if the fifth PDCP data packet is successfully received through the first bearer the fifth PDCP data packet.

Optionally, the terminal 1300 further includes:

a fourth discarding unit, configured to discard the sixth PDCP data packet if the sixth PDCP data packet is successfully received through the second bearer and its count value or sequence number is less than or equal to the count value or sequence number in the second PDCP data packet the sixth PDCP data packet.

Optionally, the terminal 1300 further includes:

A bearing releasing unit is used for releasing the first bearing.

Please refer to FIG. 14. FIG. 14 is a schematic structural diagram of a user plane function module provided in Embodiment 9 of the present disclosure. The user plane function module is located in the core network. The user plane function module 1400 includes:

The change instructing unit 1401 is configured to receive the seventh information sent by the session management function module in the core network; wherein, the seventh information is used to indicate that the downlink transmission address for the terminal is changed from the first address to the second address;

A data transmission instructing unit 1402, configured to send an end marker for the terminal and for the first service data to the access network element corresponding to the first address, and send an end marker to the access network element corresponding to the second address A start marker is sent for the terminal and for the first service data.

It should be noted here that the above-mentioned user plane functional modules provided by the embodiments of the present disclosure can implement all the method steps implemented by the above-mentioned method embodiments applied to the user plane functional modules in the core network, and can achieve the same technology Therefore, the same parts and beneficial effects in this embodiment as those in the method embodiment will not be described in detail here.

It should be noted that the division of units in the embodiments of the present application is illustrative, and is only a logical function division, and other division methods may be used in actual implementation. In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware, or may be implemented in the form of software functional units.

If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it may be stored in a processor-readable storage medium. Based on this understanding, the technical solutions of the present application can be embodied in the form of software products in essence, or the parts that contribute to the prior art, or all or part of the technical solutions, and the computer software products are stored in a storage medium , including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor (processor) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), magnetic disk or optical disk and other media that can store program codes .

It should be noted here that the above-mentioned devices provided in the embodiments of the present disclosure can implement all the method steps implemented by the corresponding method embodiments, and can achieve the same technical effects, and the same technical effects as the method embodiments in this embodiment are not repeated here. The parts and beneficial effects will be described in detail.

A tenth embodiment of the present disclosure provides a processor-readable storage medium, where the processor-readable storage medium stores a computer program, and the computer program is used to cause the processor to execute any one of the foregoing methods. For details, please refer to the description of the method steps in the above corresponding embodiments.

The processor-readable storage medium can be any available medium or data storage device that can be accessed by a processor, including, but not limited to, magnetic storage (eg, floppy disk, hard disk, magnetic tape, magneto-optical disk (MO), etc.), optical storage (eg, CD, DVD, BD, HVD, etc.), and semiconductor memory (eg, ROM, EPROM, EEPROM, non-volatile memory (NAND FLASH), solid-state disk (SSD)), etc.

The technical solutions provided in the embodiments of the present application can be applied to various systems, especially 5G systems. For example, the applicable system may be a global system of mobile communication (GSM) system, a code division multiple access (CDMA) system, a wideband code division multiple access (Wideband Code Division Multiple Access, WCDMA) general packet Wireless service (general packet radio service, GPRS) system, long term evolution (long term evolution, LTE) system, LTE frequency division duplex (frequency division duplex, FDD) system, LTE time division duplex (time division duplex, TDD) system, Long term evolution advanced (LTE-A) system, universal mobile telecommunication system (UMTS), worldwide interoperability for microwave access (WiMAX) system, 5G New Radio (New Radio, NR) system, etc. These various systems include terminal equipment and network equipment. The system may also include a core network part, such as an evolved packet system (Evloved Packet System, EPS), a 5G system (5GS), and the like.

The terminal device involved in the embodiments of the present application may be a device that provides voice and/or data connectivity to a user, a handheld device with a wireless connection function, or other processing device connected to a wireless modem. In different systems, the name of the terminal device may be different. For example, in the 5G system, the terminal device may be called user equipment (User Equipment, UE). Wireless terminal equipment can communicate with one or more core networks (Core Network, CN) via a radio access network (Radio Access Network, RAN). "telephone) and computers with mobile terminal equipment, eg portable, pocket-sized, hand-held, computer-built or vehicle-mounted mobile devices, which exchange language and/or data with the radio access network. For example, Personal Communication Service (PCS) phones, cordless phones, Session Initiated Protocol (SIP) phones, Wireless Local Loop (WLL) stations, Personal Digital Assistants (Personal Digital Assistants), PDA) and other devices. Wireless terminal equipment may also be referred to as system, subscriber unit, subscriber station, mobile station, mobile station, remote station, access point , a remote terminal device (remote terminal), an access terminal device (access terminal), a user terminal device (user terminal), a user agent (user agent), and a user device (user device), which are not limited in the embodiments of the present application.

The base station involved in the embodiments of the present application may include multiple cells that provide services for the terminal. Depending on the specific application, the base station may also be called an access point, or may be a device in the access network that communicates with wireless terminal equipment through one or more sectors on the air interface, or other names. The network device can be used to exchange received air frames with Internet Protocol (IP) packets, and act as a router between the wireless terminal device and the rest of the access network, which can include the Internet. Protocol (IP) communication network. The network devices may also coordinate attribute management for the air interface. For example, the network device involved in the embodiments of the present application may be a network device (Base Transceiver Station, BTS) in the Global System for Mobile Communications (GSM) or Code Division Multiple Access (Code Division Multiple Access, CDMA). ), it can also be a network device (NodeB) in Wide-band Code Division Multiple Access (WCDMA), or it can be an evolved network device in a long term evolution (LTE) system (evolutional Node B, eNB or e-NodeB), 5G base station (gNB) in 5G network architecture (next generation system), or Home evolved Node B (HeNB), relay node (relay node) , a home base station (femto), a pico base station (pico), etc., which are not limited in the embodiments of the present application. In some network structures, a network device may include a centralized unit (CU) node and a distributed unit (DU) node, and the centralized unit and the distributed unit may also be geographically separated.

One or more antennas can be used between the base station and the terminal device for multiple input multiple output (Multi Input Multi Output, MIMO) transmission, and the MIMO transmission can be single user MIMO (Single User MIMO, SU-MIMO) or multi-user MIMO ( Multiple User MIMO, MU-MIMO). According to the form and number of root antenna combinations, MIMO transmission can be 2D-MIMO, 3D-MIMO, FD-MIMO, or massive-MIMO, or diversity transmission, precoding transmission, or beamforming transmission.

As will be appreciated by those skilled in the art, the embodiments of the present application may be provided as a method, a system, or a 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 having computer-usable program code embodied therein, including but not limited to disk storage, optical storage, and the like.

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

These processor-executable instructions may also be stored in a processor-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the processor-readable memory result in the manufacture of means including the instructions product, the instruction means implements the functions specified in the flow or flow of the flowchart and/or the block or blocks of the block diagram.

These processor-executable instructions can also be loaded onto a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process that Execution of the instructions provides steps for implementing the functions specified in the flowchart or blocks and/or the block or blocks of the block diagrams.

It will be appreciated that the embodiments described in this disclosure may be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, modules, units, sub-modules, sub-units, etc. can be implemented in one or more Application Specific Integrated Circuits (ASIC), Digital Signal Processing (DSP), digital signal processing equipment ( DSP Device, DSPD), Programmable Logic Device (Programmable Logic Device, PLD), Field-Programmable Gate Array (Field-Programmable Gate Array, FPGA), general-purpose processor, controller, microcontroller, microprocessor, for in other electronic units or combinations thereof that perform the functions described herein.

Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

A transmission method, applied to a first radio access network element, includes:

The first radio access network element sends first information to the terminal, where the first information is used to indicate the correspondence between the PDCP count value of the first bearer of the terminal and the PDCP count value of the second bearer, Or used to indicate the correspondence between the PDCP sequence number of the first bearer of the terminal and the PDCP sequence number of the second bearer.
The method of claim 1, wherein the first bearer is a source radio bearer or a temporary radio bearer, and the second bearer is a target radio bearer.
The method of claim 1, wherein the first information includes an offset between PDCP count values of the first bearer and the second bearer or includes the first bearer and the second bearer Offset between PDCP sequence numbers of bearers.
The method according to claim 1, wherein the first information includes second information and third information, and the second information is a count value or a sequence number of a first PDCP data packet in the first bearer, The third information is the count value or sequence number of the second PDCP data packet in the second bearer; the first PDCP data packet is the data packet in the first bearer that is terminated for reception, and the second PDCP data packet The data packet is the data packet that starts to be received in the second bearer;

The service data included in the first PDCP data packet and the second PDCP data packet are both first service data.
The method according to claim 1, wherein after the first radio access network element sends the first information to the terminal, the method further comprises:

The first radio access network element releases the first bearer.
The method according to claim 1, wherein before the first radio access network element sends the first information to the terminal, the method further comprises:

receiving, by the first radio access network element, fourth information sent by a user plane function module in the core network, where the fourth information includes a first flag for the first service data;

receiving, by the first radio access network element, fifth information sent by a second radio access network element, where the fifth information includes a second flag for the first service data;

One of the first marker and the second marker is a start marker, and the other is an end marker.
The method according to claim 6, wherein the fifth information further comprises a count value or a sequence number of a first PDCP data packet in the first bearer, and the first PDCP data packet is the first bearer Received packets at the end of the period.
The method according to claim 6 or 7, further comprising:

The first radio access network element determines the first information according to the fourth information and the fifth information.
The method according to claim 1, wherein before the step of the first radio access network element sending the first information to the terminal, the method further comprises:

The first radio access network element receives sixth information sent by the second radio access network element, where the sixth information is used to indicate the corresponding relationship.
A transmission method, applied to a terminal, includes:

The terminal receives the first information sent by the first radio access network element, where the first information is used to indicate the correspondence between the PDCP count value of the first bearer of the terminal and the PDCP count value of the second bearer , or used to indicate the correspondence between the PDCP sequence number of the first bearer of the terminal and the PDCP sequence number of the second bearer.
The method of claim 10, further comprising:

If the terminal has successfully received the third PDCP data packet through the first bearer, and successfully received the fourth PDCP data packet through the second bearer, and the count value or sequence number of the fourth PDCP data packet is the same as the If the count value or sequence number of the third PDCP data packet is corresponding, then discard the fourth PDCP data packet;

or,

If the terminal has successfully received the fourth PDCP data packet through the second bearer, and successfully received the third PDCP data packet through the first bearer, and the count value or sequence number of the third PDCP data packet is the same as that of the third PDCP data packet. If the count value or sequence number of the fourth PDCP data packet is corresponding, the third PDCP data packet is discarded.
The method of claim 10, wherein the first information includes an offset between PDCP count values of the first bearer and the second bearer or includes the first bearer and the second bearer Offset between PDCP sequence numbers of bearers.
The method according to claim 10, wherein the first information includes second information and third information, and the second information is a count value or a sequence number of a first PDCP data packet in the first bearer, The third information is the count value or sequence number of the second PDCP data packet in the second bearer; the first PDCP data packet is the data packet in the first bearer that is terminated for reception, and the second PDCP data packet The data packet is the data packet that starts to be received in the second bearer;

The service data included in the first PDCP data packet and the second PDCP data packet are both first service data.
The method according to claim 13, wherein after the terminal receives the first information sent by the first radio access network element, the method further comprises:

If the terminal successfully receives the fifth PDCP data packet through the first bearer, and its count value or sequence number is greater than or equal to the count value or sequence number in the first PDCP data packet, discard the fifth PDCP data packet. PDCP packets.
The method according to claim 13, wherein after the terminal receives the first information sent by the first radio access network element, the method further comprises:

If the terminal successfully receives the sixth PDCP data packet through the second bearer, and its count value or sequence number is less than or equal to the count value or sequence number in the second PDCP data packet, discard the sixth PDCP data packet. PDCP packets.
The method according to claim 10, wherein after the terminal receives the first information sent by the first radio access network element, the method further comprises:

The terminal releases the first bearer.
A transmission method, applied to a user plane functional module in a core network, includes:

The user plane function module receives seventh information sent by the session management function module in the core network; wherein the seventh information is used to indicate that the downlink transmission address for the terminal is changed from the first address to the second address;

The user plane function module sends an end marker for the terminal and for the first service data to the access network element corresponding to the first address, and sends an end marker for the access network element corresponding to the second address. The terminal and for the start marker of the first service data.
A network element of a wireless access network, comprising a memory, a transceiver, and a processor:

a memory for storing a computer program; a transceiver for sending and receiving data under the control of the processor; a processor for reading the computer program in the memory and performing the following operations:

Send first information to the terminal, where the first information is used to indicate the correspondence between the PDCP count value of the first bearer of the terminal and the PDCP count value of the second bearer, or the first information of the terminal. Correspondence between the PDCP sequence number of the bearer and the PDCP sequence number of the second bearer.
The radio access network element of claim 18, wherein the first information includes an offset between PDCP count values of the first bearer and the second bearer or includes the first bearer The offset from the PDCP sequence number of the second bearer.
The network element of the radio access network according to claim 18, wherein the first information includes second information and third information, and the second information is the count of the first PDCP data packets in the first bearer value or sequence number, the third information is the count value or sequence number of the second PDCP data packet in the second bearer; the first PDCP data packet is the data packet in the first bearer that is terminated for reception, The second PDCP data packet is a data packet that starts to be received in the second bearer;

The service data included in the first PDCP data packet and the second PDCP data packet are both first service data.
The network element of the wireless access network according to claim 18, wherein after the sending the first information to the terminal, the processor is further configured to perform the following operations:

The first bearer is released.
The network element of the wireless access network according to claim 18, wherein before the sending the first information to the terminal, the transceiver is further configured to:

receiving fourth information sent by a user plane function module in the core network, where the fourth information includes a first flag for the first service data;

receiving fifth information sent by a second radio access network element, where the fifth information includes a second flag for the first service data;

One of the first marker and the second marker is a start marker, and the other is an end marker.
The network element of the wireless access network according to claim 22, wherein the fifth information further includes a count value or a sequence number of a first PDCP data packet in the first bearer, and the first PDCP data packet is Data packets for which reception is terminated in the first bearer.
The radio access network element according to claim 22 or 23, wherein the processor is further configured to perform the following operations:

The first information is determined according to the fourth information and the fifth information.
The wireless access network element according to claim 18, wherein before the step of sending the first information to the terminal, the transceiver is further configured to:

Receive sixth information sent by the network element of the second radio access network, where the sixth information is used to indicate the corresponding relationship.
A terminal, comprising a memory, a transceiver, and a processor:

a memory for storing a computer program; a transceiver for sending and receiving data under the control of the processor; a processor for reading the computer program in the memory and performing the following operations:

Receive the first information sent by the network element of the first radio access network, where the first information is used to indicate the correspondence between the PDCP count value of the first bearer of the terminal and the PDCP count value of the second bearer, or use Indicates the correspondence between the PDCP sequence number of the first bearer of the terminal and the PDCP sequence number of the second bearer.
The terminal according to claim 26, wherein the processor is further configured to perform the following operations:

If the third PDCP data packet has been successfully received through the first bearer, and the fourth PDCP data packet has been successfully received through the second bearer, and the count value or sequence number of the fourth PDCP data packet is the same as that of the third PDCP data packet If the count value or sequence number of the PDCP data packet is corresponding, then discard the fourth PDCP data packet;

or,

If the fourth PDCP data packet has been successfully received through the second bearer, and the third PDCP data packet has been successfully received through the first bearer, and the count value or sequence number of the third PDCP data packet is the same as the fourth PDCP data packet If the count value or sequence number of the PDCP data packet is corresponding, the third PDCP data packet is discarded.
The terminal of claim 26, wherein the first information includes an offset between PDCP count values of the first bearer and the second bearer or includes the first bearer and the second bearer Offset between PDCP sequence numbers of bearers.
The terminal according to claim 26, wherein the first information includes second information and third information, and the second information is a count value or a sequence number of a first PDCP data packet in the first bearer, The third information is the count value or sequence number of the second PDCP data packet in the second bearer; the first PDCP data packet is the data packet in the first bearer that is terminated for reception, and the second PDCP data packet The data packet is the data packet that starts to be received in the second bearer;

The service data included in the first PDCP data packet and the second PDCP data packet are both first service data.
The terminal according to claim 29, wherein after receiving the first information sent by the first radio access network element, the processor is further configured to perform the following operations:

If the fifth PDCP data packet is successfully received through the first bearer, and its count value or sequence number is greater than or equal to the count value or sequence number in the first PDCP data packet, discard the fifth PDCP data packet .
The terminal according to claim 29, wherein after receiving the first information sent by the first radio access network element, the processor is further configured to perform the following operations:

If the sixth PDCP data packet is successfully received through the second bearer, and its count value or sequence number is less than or equal to the count value or sequence number in the second PDCP data packet, discard the sixth PDCP data packet .
The terminal according to claim 26, wherein after receiving the first information sent by the first radio access network element, the processor is further configured to perform the following operations:

The first bearer is released.
A user plane function module, the user plane function module is located in a core network, and includes a memory, a transceiver, and a processor:

a memory for storing a computer program; a transceiver for sending and receiving data under the control of the processor; a processor for reading the computer program in the memory and performing the following operations:

receiving seventh information sent by the session management function module in the core network; wherein the seventh information is used to indicate that the downlink transmission address for the terminal is changed from the first address to the second address;

Send an end marker for the terminal and for the first service data to the access network element corresponding to the first address, and send an end marker for the terminal and for the first service data to the access network element corresponding to the second address. The start tag of the first service data is described.
A wireless access network network element, comprising:

The first information sending unit is configured to send first information to the terminal, where the first information is used to indicate the correspondence between the PDCP count value of the first bearer of the terminal and the PDCP count value of the second bearer, or use Indicates the correspondence between the PDCP sequence number of the first bearer of the terminal and the PDCP sequence number of the second bearer.
A terminal that includes:

a first information receiving unit, configured to receive first information sent by a first radio access network element, where the first information is used to indicate the PDCP count value of the first bearer of the terminal and the PDCP count value of the second bearer The corresponding relationship between, or used to indicate the corresponding relationship between the PDCP sequence number of the first bearer of the terminal and the PDCP sequence number of the second bearer.
A user plane function module, the user plane function module is located in a core network, including:

a change instruction unit, configured to receive seventh information sent by the session management function module in the core network; wherein the seventh information is used to indicate that the downlink transmission address for the terminal is changed from the first address to the second address;

a data transmission instructing unit, configured to send an end marker for the terminal and for the first service data to the access network element corresponding to the first address, and send the end marker to the access network element corresponding to the second address A start marker for the terminal and for the first service data.
A processor-readable storage medium, wherein the processor-readable storage medium stores a computer program for causing the processor to perform the method of any one of claims 1 to 17.