CN116192329A

CN116192329A - Method and communication device for transmitting data packet in PDU (protocol data unit) session

Info

Publication number: CN116192329A
Application number: CN202111437794.4A
Authority: CN
Inventors: 李永翠; 倪慧
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-11-29
Filing date: 2021-11-29
Publication date: 2023-05-30
Also published as: WO2023093493A1

Abstract

In the scenario of I-SMF update (change/insert/remove) or I-UPF update (change/insert/remove) in a PDU session, a PSA receives an uplink packet of the same PDU session from different paths to cause a problem of uplink packet disorder, or an access network device receives a downlink packet of the same PDU session from different paths to cause a problem of downlink packet disorder, and by using a gateway (e.g., PSA, access network device or I-UPF) to sequence data packets of the same PDU session from different paths, the uplink data packets or the downlink data packets are transmitted according to a normal sequence, so that a process of sequencing the data packets by a terminal device or a server is avoided, and communication delay is reduced, thereby ensuring communication efficiency.

Description

Method and communication device for transmitting data packet in PDU (protocol data unit) session

Technical Field

The present invention relates to the field of communications, and more particularly, to a method and a communications device for transmitting data packets in a PDU session.

Background

In 3GPP, the edge computing platform locations supported by session management function (session management function, SMF) network elements may be limited. When the position of the edge computing platform which is expected to be accessed by the terminal equipment at the network side is not in the supporting range of the SMF, an intermediate SMF (I-SMF) is inserted; when the position of the edge computing platform which is expected to be accessed by the terminal equipment at the network side is not in the supporting range of the I-SMF, I-SMF change (change) occurs; when the edge computing platform position which the network side expects the terminal equipment to access is in the SMF supporting range, removing the I-SMF; the updating of I-SMF occurs in both of these scenarios. The intermediate user plane function elements ((intermediate user plane funtion UPF, I-UPF)) controlled or managed by the I-SMF will also update (change/insert/remove) due to the update of the I-SMF such that for the same protocol data unit (protocol data unit, PDU) session with the terminal device, packets in the same PDU session will appear both from the pre-I-UPF path and from the post-I-UPF path.

For example, for upstream packets, the PDU session anchor (PDU session anchor, PSA) receives packets from both paths and sends the packets on both paths to the server separately. For the server, the packets received on the path before the I-UPF update are needed to be received earlier in time sequence than the packets received on the path after the I-UPF update. Because the time when the data packets on the two paths reach the PSA is different, when the data packets on the path before the I-UPF update reach the PSA later than the data packets on the path after the I-UPF update, the PSA directly sends the data packets on the two paths to the server, so that the data packets received by the server from the path before the I-UPF update are received later than the data packets received on the path after the I-UPF update in time sequence, thereby causing the disorder of the data packets received by the server, increasing the ordering time of the data packets by the server, reducing the communication efficiency and reducing the user experience.

For downlink data packets, the access network device receives data packets from two paths and sends the data packets on the two paths to the terminal device. For the terminal device, the packets received on the path before the I-UPF update are needed earlier in time sequence than the packets received on the path after the I-UPF update. Because the time that the data packets on the two paths reach the access network equipment is different, when the data packets on the path before the I-UPF update reach the access network equipment later than the data packets on the path after the I-UPF update, the access network equipment directly sends the data packets on the two paths to the terminal equipment, so that the data packets received by the terminal equipment from the path before the I-UPF update are caused to be later than the data packets received on the path after the I-UPF update in time sequence, thereby causing the disorder of the data packets received by the terminal equipment, increasing the ordering time of the data packets by the terminal equipment, reducing the communication efficiency and causing the user experience to be reduced.

Disclosure of Invention

In the scene of I-SMF update (change/insert/remove) or I-UPF update (change/insert/remove) in PDU session, the data packets of one PDU session from different paths are ordered by using one gateway (PSA, access network device or I-UPF), so that uplink data packets or downlink data packets are transmitted according to the normal order, the ordering process of the data packets by a terminal device or a server is avoided, the communication delay is reduced, and the communication efficiency is ensured.

In a first aspect, a method for transmitting data packets in a PDU session is provided, the method comprising: the PSA receives first indication information sent by the SMF, wherein the first indication information is used for indicating: the PSA caches the uplink data packet received on the first path, and when receiving the end mark from the second path, sends a message to the SMF, where the message is used to indicate that the PSA receives the end mark, and the end mark is used to indicate that the transmission of the uplink data packet on the second path is ended, and the uplink data packet on the first path and the uplink data packet on the second path are uplink data packets of the same PDU session; after receiving the end mark, the PSA sends the message to the SMF; the PSA receives second indication information from the SMF, wherein the second indication information is used for indicating the PSA to send the cached uplink data packet; the PSA sends an uplink data packet cached on the first path according to the second indication information; the transmission sequence of the uplink data packet on the first path is as follows: terminal equipment, access network equipment, new I-UPF, the PSA, or terminal equipment, access network equipment, the PSA; the transmission sequence of the uplink data packets on the second path is as follows: terminal equipment, access network equipment, source I-UPF, the PSA, or terminal equipment, access network equipment, the PSA.

According to the method for transmitting the data packets in the PDU session, the PSA is used for ordering the received uplink data packets from the same PDU session on the new path (the first path) and the old path (the second path), before the PSA receives the indication information which indicates that the uplink data packets sent on the old path are sent completely, the PSA is used for caching the uplink data packets received on the new path, after the PSA receives the indication information which indicates that the uplink data packets sent on the old path are sent completely, the PSA is used for sending the uplink data packets which are received on the new path, so that the uplink data packets in one PDU session can be sent according to the normal sequence, the ordering time of the server on the uplink data packets is saved, and the communication efficiency is guaranteed.

In a possible implementation manner of the first aspect, the method further includes: the PSA transmits the upstream data packet from the second path upon receiving the upstream data packet from the second path.

In one possible implementation manner of the first aspect, the PSA receives the end flag, including: the PSA receives the end flag from the access network device.

In a second aspect, there is provided a method for transmitting data packets in a PDU session, the method comprising: the SMF sends first indication information to the PSA, wherein the first indication information is used for indicating: the PSA buffers the uplink data packet received on the first path, and when receiving the end mark from the second path, sends a message to the SMF, the message is used for indicating that the PSA receives the end mark, the end mark is used for indicating that the transmission of the uplink data packet on the second path is ended, and the uplink data packet on the first path and the uplink data packet on the second path are uplink data packets of the same PDU session; the SMF receives the message sent by the PSA; the SMF sends second indication information to the PSA, wherein the second indication information is used for indicating the PSA to send the cached uplink data packet; the transmission sequence of the uplink data packet on the first path is as follows: terminal equipment, access network equipment, new intermediate user plane function network element I-UPF, the PSA, or terminal equipment, access network equipment, the PSA; the transmission sequence of the uplink data packets on the second path is as follows: terminal equipment, access network equipment, source I-UPF, the PSA, or terminal equipment, access network equipment, the PSA.

According to the method for transmitting the data packet in the PDU session provided in the second aspect, before the PSA is instructed to receive the instruction information indicating that the uplink data packet is sent on the old path (the second path), the PSA buffers the uplink data packet received on the new path (the first path), after the PSA receives the instruction information indicating that the uplink data packet sent on the old path is sent, the PSA buffers the uplink data packet received on the new path before sending, so that the uplink data packet in one PDU session can be ensured to be sent in a normal sequence, and the ordering time of the server on the uplink data packet is saved, and the communication efficiency is ensured.

In a possible implementation manner of the second aspect, before the SMF sends the first indication information to the PSA, the method further includes: the SMF receives first information from the AMF or the new I-SMF; the SMF determines to send first indication information to the PSA according to the first information; wherein the first information includes: the access network equipment is unchanged in indication information or third indication information, wherein the third indication information is used for indicating the sorting of the uplink data packets. In this implementation, before determining, according to the information sent by the AMF or the new I-SMF, that the indication PSA receives the indication information sent on the old path and indicating that the uplink data packet has been sent, the SMF buffers the uplink data packet received on the new path, so that it can be ensured that the uplink data packet in one PDU session is sent in a normal order, thereby saving the ordering time of the server for the uplink data packet and ensuring the communication efficiency.

In a possible implementation manner of the second aspect, the method further includes: the SMF sends fourth indication information to the AMF or the access network device, where the fourth indication information is used to instruct the access network device to send the end flag on the second path. In this implementation, the SMF may instruct the access network device to send an end flag on the second path, thereby ensuring that the PSA receives the end flag on the old path, ensuring that the PSA may smoothly send the buffered data packet, and ensuring the efficiency of data packet transmission.

In a third aspect, a method for transmitting data packets in a PDU session is provided, the method comprising: the access network equipment receives second information sent by the AMF network element; the access network equipment sends an end mark on a second path according to the second information, wherein the end mark is used for indicating the end of the transmission of the uplink data packet on the second path; the access network equipment sends an uplink data packet on a first path; the transmission sequence of the uplink data packet on the first path is as follows: terminal equipment, access network equipment, new I-UPF, the PSA, or terminal equipment, access network equipment, the PSA; the transmission sequence of the uplink data packets on the second path is as follows: terminal equipment, access network equipment, source I-UPF, the PSA, or terminal equipment, access network equipment, the PSA.

According to the method for transmitting the data packet in the PDU session, the access network device can send the end mark on the second path (the old path), so that the PSA is guaranteed to receive the end mark on the old path, the PSA can smoothly send the cached data packet, and the efficiency of data packet transmission is guaranteed.

In a possible implementation manner of the third aspect, the second information includes: at least one of the tunnel information of the new I-UPF, the tunnel information of the PSA, the fourth indication information, or the indication information of the access network device unchanged; the fourth indication information is used for indicating the access network device to send the end mark on the second path.

In a fourth aspect, a method for transmitting data packets in a PDU session is provided, the method comprising: the access network device receives fifth indication information from the AMF, where the fifth indication information is used to indicate: before receiving the end mark on the second path, the access network device caches the downlink data packet from the first path; the access network equipment caches the downlink data packet from the first path before receiving the end mark on the second path according to the fifth indication information, wherein the downlink data packet on the first path and the downlink data packet on the second path are downlink data packets of the same PDU session, and the end mark is used for indicating the end of the transmission of the downlink data packet on the second path; the access network equipment sends the downlink data packet received on the second path to the terminal equipment; when the access network device receives the end mark on the second path, the access network device sends the cached downlink data packets to the terminal device, wherein the transmission sequence of the downlink data packets on the first path is as follows in sequence: the transmission sequence of the downlink data packet on the second path of the PSA, the new I-UPF, the access network equipment and the terminal equipment is as follows: PSA, source I-UPF, access network device, terminal device, or PSA, access network device, terminal device.

According to the method for transmitting the data packets in the PDU session provided in the fourth aspect, the access network device sorts the downlink data packets received from the same PDU session on the new path (the first path) and the old path (the second path), before the access network device receives the indication information that the data packets sent on the old path have been sent, the access network device buffers the downlink data packets received on the new path, after the access network device receives the indication information that the downlink data packets sent on the old path have been sent, the access network device sends the downlink data packets received on the new path buffered before, and for the downlink data packets on the old path, the access network device sends the downlink data packets according to the normal flow. Therefore, the downlink data packet in one PDU session can be ensured to be sent according to the normal sequence, thereby ensuring the message sequence of the PDU session and ensuring the communication efficiency.

In a possible implementation manner of the fourth aspect, the fifth indication information includes: indicating information that the access network equipment is unchanged.

In a possible implementation manner of the fourth aspect, the receiving, by the access network device, the end flag on the second path includes: the access network device receives the end tag from the PSA on a second path.

In a fifth aspect, a method for transmitting data packets in a PDU session is provided, the method comprising: the PSA receiving third information from the SMF; the PSA sends an end mark on the second path according to the third information, wherein the end mark is used for indicating the end of the transmission of the downlink data packet on the second path; the transmission sequence of the downlink data packet on the first path is as follows: the transmission sequence of the downlink data packet on the second path of the PSA, the new I-UPF, the access network equipment and the terminal equipment is as follows: the method comprises the steps of PSA, source I-UPF, access network equipment and terminal equipment, or the PSA, the access network equipment and the terminal equipment, wherein the downlink data packet on a first path and the downlink data packet on a second path are downlink data packets of the same PDU session.

In the method provided in the fifth aspect, the PSA may send an end flag on the second path (old path), so as to ensure that the access network device receives the end flag on the old path, ensure that the access network device can smoothly send the buffered downlink data packet, and ensure the efficiency of downlink data packet transmission.

In a possible implementation manner of the fifth aspect, the third information includes: downstream tunnel information or indication information for updating PSA, the indication information being used to indicate: the PSA sends the end flag on a second path.

In a sixth aspect, a method for transmitting data packets in a PDU session is provided, where the method includes:

the SMF receives fourth information from the AMF or the new I-SMF; the SMF sends third information to the PSA according to the fourth information, the third information being used to indicate: the PSA sends an end mark on the second path, wherein the end mark is used for indicating the end of the transmission of the downlink data packet on the second path; the transmission sequence of the downlink data packet on the first path is as follows: the transmission sequence of the downlink data packet on the second path of the PSA, the new I-UPF, the access network equipment and the terminal equipment is as follows: the method comprises the steps of PSA, source I-UPF, access network equipment and terminal equipment, or the PSA, the access network equipment and the terminal equipment, wherein the downlink data packet on a first path and the downlink data packet on a second path are downlink data packets of the same PDU session.

According to the method provided by the sixth aspect, the SMF can determine, according to information from the AMF or the new I-SMF, an end flag indicating that the PSA sends on the second path (old path), so as to ensure that the access network device receives the end flag on the old path, ensure that the access network device can smoothly send the buffered downlink data packet, and ensure the efficiency of downlink data packet transmission.

In a possible implementation manner of the sixth aspect, the fourth information includes: the indication information that the access network device is unchanged or the indication information for indicating the ordering of the downlink data packets.

In a seventh aspect, a method for transmitting data packets in a PDU session is provided, the method comprising: the new I-UPF receives a sixth indication information from the first network element, where the sixth indication information is used to indicate: the new I-UPF caches the uplink data packet received on the first path, and when receiving the end mark from the second path, sends a message to the first network element, wherein the message is used for indicating that the new I-UPF receives the end mark, the end mark is used for indicating that the transmission of the uplink data packet on the second path is ended, and the uplink data packet on the first path and the uplink data packet on the second path are uplink data packets of the same PDU session; after the new I-UPF receives the end mark, the new I-UPF sends the message to a first network element; the new I-UPF receives seventh indication information from the first network element, wherein the seventh indication information is used for indicating the new I-UPF to send the cached uplink data packet; the new I-UPF sends the uplink data packet cached on the first path according to the seventh indication information; the transmission sequence of the uplink data packet on the first path is as follows: the transmission sequence of the uplink data packet on the second path is sequentially as follows: terminal equipment, access network equipment, source I-UPF, the new I-UPF, PSA, or terminal equipment, access network equipment, PSA, the new I-UPF, the PSA.

According to the method for transmitting the data packets in the PDU session, the I-UPF is used for sequencing the received uplink data packets from the same PDU session on the new path (the first path) and the old path (the second path), before the I-UPF receives the indication information which indicates that the uplink data packets are sent on the old path and is sent completely, the I-UPF buffers the received uplink data packets on the new path, after the I-UPF receives the indication information which indicates that the uplink data packets are sent completely and is sent completely, the I-UPF buffers the received uplink data packets on the new path, so that the uplink data packets in one PDU session can be sent according to the normal sequence, and the sequencing time of the uplink data packets by a server is saved, and the communication efficiency is guaranteed.

In a possible implementation manner of the seventh aspect, the method further includes: the new I-UPF, upon receiving an upstream packet from the second path, transmits the upstream packet from the second path. In this implementation, sequential transmission of upstream packets on the old path may be guaranteed.

In a possible implementation manner of the seventh aspect, the receiving, by the new I-UPF, the end flag includes: the new I-UPF receives the end flag from the access network device.

In an eighth aspect, a method for transmitting data packets in a PDU session is provided, the method comprising: the first network element sends sixth indication information to the new I-UPF, where the sixth indication information is used to indicate: the new I-UPF caches the uplink data packet received on the first path, and when receiving the end mark from the second path, sends a message to the first network element, wherein the message is used for indicating that the new I-UPF receives the end mark, and the end mark is used for indicating that the transmission of the uplink data packet on the second path is ended; the first network element receives the message sent by the new I-UPF; the first network element sends sixth indication information to the new I-UPF, wherein the sixth indication information is used for indicating the new I-UPF to send the cached uplink data packet; the uplink data packet on the first path and the uplink data packet on the second path are uplink data packets of the same PDU session, and the transmission sequence of the uplink data packets on the first path is as follows: the transmission sequence of the uplink data packet on the second path is sequentially as follows: terminal equipment, access network equipment, source I-UPF, the new I-UPF, PSA, or terminal equipment, access network equipment, PSA, the new I-UPF, the PSA.

According to the method for transmitting the data packet in the PDU session provided in the eighth aspect, before the first network element can instruct the new I-UPF to receive the end mark of the uplink data packet sent on the old path (the second path), the new I-UPF buffers the uplink data packet received on the new path (the first path), after the new I-UPF receives the end mark of the uplink data packet sent on the old path, the new I-UPF buffers the uplink data packet received on the new path before sending, so that the uplink data packet in one PDU session can be ensured to be sent according to the normal sequence, the ordering time of the server on the uplink data packet is saved, and the communication efficiency is ensured.

In a possible implementation manner of the eighth aspect, before the first network element sends the fifth indication information to the new I-UPF, the method further includes: the first network element receives fifth information from the AMF; the first network element determines to send sixth indication information to the new I-UPF according to the fifth information; wherein the fifth information includes: the access network device is unchanged in indication information or eighth indication information, where the eighth indication information is used to indicate to sort the uplink data packets. In this implementation, the first network element may determine, according to the information from the AMF, to instruct the new I-UPF to buffer the uplink data packets received on the first path, and when receiving the end flag from the second path, send a message to the first network element, so as to ensure that the I-UPF sorts the received uplink data packets from the same PDU session on the new path and the old path. Therefore, the uplink data packets in one PDU session are ensured to be sent according to the normal sequence, so that the ordering time of the server to the uplink data packets is saved, and the communication efficiency is ensured.

In a possible implementation manner of the eighth aspect, before the first network element sends the fifth indication information to the new I-UPF, the method further includes: the first network element sends sixth information to the source I-SMF or SMF, the sixth information including: the access network equipment is unchanged in indication information or ninth indication information, wherein the ninth indication information is used for indicating a source I-SMF or determining to establish a forwarding tunnel by the SMF, and the forwarding tunnel is used for forwarding an uplink data packet; the first network element receives response information from the source I-SMF or SMF in response to the sixth information, where the response information includes a forwarding indication, where the forwarding indication is used to establish a forwarding tunnel between the new I-UPF and the source I-UPF, or between the new I-UPF and the PSA, or between the source I-UPF and the PSA.

In a possible implementation manner of the eighth aspect, the method further includes: the first network element sends tenth indication information to the AMF or the access network device, wherein the tenth indication information is used for indicating: the access network device sends the end flag on the second path.

In a possible implementation manner of the eighth aspect, the tenth indication information includes: tunnel information for the new I-UPF.

In a possible implementation manner of the eighth aspect, the first network element is an SMF or a new I-SMF.

In a ninth aspect, there is provided a method for transmitting data packets in a PDU session, the method comprising: the access network equipment receives seventh information sent by the AMF network element; the access network equipment sends an end mark on the second path according to the seventh information, wherein the end mark is used for indicating the end of the transmission of the uplink data packet on the second path; the access network equipment sends an uplink data packet on a first path; the uplink data packet on the first path and the uplink data packet on the second path are uplink data packets of the same PDU session, and the transmission sequence of the uplink data packets on the first path is as follows: the transmission sequence of the uplink data packet on the second path is sequentially as follows: terminal equipment, access network equipment, source I-UPF, the new I-UPF, PSA, or terminal equipment, access network equipment, PSA, the new I-UPF, the PSA.

According to the method for transmitting the data packet in the PDU session, the access network device can send the end mark on the second path (the old path), so that the new I-UPF is guaranteed to receive the end mark on the old path, the new I-UPF can smoothly send the cached data packet, and the efficiency of data packet transmission is guaranteed.

In a possible implementation manner of the ninth aspect, the seventh information includes: tunnel information of the new I-UPF or tenth indication information for indicating: the access network device sends the end flag on the second path.

In a tenth aspect, there is provided a method for transmitting data packets in a PDU session, the method comprising: the new I-UPF receives eleventh indication information from the second network element, where the eleventh indication information is used to indicate: the new I-UPF caches the downlink data packet received on the first path, and when receiving an end mark from the second path, sends a message to the second network element, wherein the message is used for indicating that the new I-UPF receives the end mark, the end mark is used for indicating that the transmission of the downlink data packet on the second path is ended, and the uplink data packet on the first path and the downlink data packet on the second path are uplink data packets of the same PDU session; after the new I-UPF receives the end mark, the new I-UPF sends the message to a second network element; the new I-UPF receives twelfth indication information from the SMF, wherein the twelfth indication information is used for indicating the new I-UPF to send the cached downlink data packet; the new I-UPF sends the downlink data packet cached on the first path according to the twelfth indication information; the transmission sequence of the downlink data packet on the first path is as follows: the transmission sequence of the downlink data packet on the second path is as follows: PSA, source I-UPF, new I-UPF, access network device, terminal device, or PSA, access network device, new I-UPF, access network device, terminal device.

According to the method for transmitting the data packets in the PDU conversation provided in the tenth aspect, the downlink data packets of the PDU conversation received from the new path (the first path) and the old path (the second path) are ordered through the I-UPF, before the I-UPF receives the indication information that the downlink data packets sent on the old path are sent completely, the I-UPF buffers the downlink data packets received on the new path, after the I-UPF receives the indication information that the downlink data packets sent on the old path are sent completely, the I-UPF buffers the downlink data packets received on the new path before the I-UPF sends, so that the uplink data packets in one PDU conversation can be guaranteed to be sent according to the normal sequence, and the communication efficiency is guaranteed.

In a possible implementation manner of the tenth aspect, the receiving, by the new I-UPF, the end flag includes: the new I-UPF receives the end-tag from the PSA.

In a possible implementation manner of the tenth aspect, the second network element is a new I-SMF or SMF.

In an eleventh aspect, there is provided a method for transmitting data packets in a PDU session, the method comprising: the second network element receives eighth information from the AMF, the eighth information comprising: the indication information which is unchanged by the access network equipment or thirteenth indication information is used for indicating the downlink data packet to be ordered; the second network element sends eleventh indication information to the new I-UPF according to eighth information, wherein the eleventh indication information is used for indicating: the new I-UPF caches the downlink data packet received on the first path, and when receiving an end mark from the second path, sends a message to the second network element, wherein the message is used for indicating that the new I-UPF receives the end mark, and the end mark is used for indicating that the transmission of the downlink data packet on the second path is ended; the uplink data packet on the first path and the downlink data packet on the second path are uplink data packets of the same PDU session, and the transmission sequence of the downlink data packets on the first path is as follows: the transmission sequence of the downlink data packet on the second path is as follows: PSA, source I-UPF, new I-UPF, access network device, terminal device, or PSA, access network device, new I-UPF, access network device, terminal device.

According to the method for transmitting the data packets in the PDU session, the second network element can instruct the I-UPF to sort the downlink data packets according to the information from the AMF, so that the I-UPF can sort the received downlink data packets from the same PDU session on the new path (the first path) and the old path (the second path), and therefore the uplink data packets in one PDU session can be guaranteed to be transmitted according to the normal sequence, the sorting time of the server on the uplink data packets is saved, and the communication efficiency is guaranteed.

In a possible implementation manner of the eleventh aspect, before the second network element sends the tenth indication information to the new I-UPF, the method further includes: the second network element sends ninth information to the source I-SMF or SMF, the ninth information including: the method comprises the steps that indication information which is unchanged or fourteenth indication information of access network equipment is used for indicating a source I-SMF or determining to establish a forwarding tunnel by the SMF, and the forwarding tunnel is used for forwarding downlink data packets; the second network element receives response information from the source I-SMF or SMF in response to the ninth information, where the response information includes a forwarding indication, where the forwarding indication is used to establish a forwarding tunnel between the new I-UPF and the source I-UPF, or establish a forwarding tunnel between the source I-UPF and the PSA, or establish a forwarding tunnel between the access network device and the PSA.

In a possible implementation manner of the eleventh aspect, the method further includes: the second network element sends tenth information to the PSA, the tenth information being used to indicate: the PSA sends the end flag on a second path.

In a possible implementation manner of the eleventh aspect, the tenth information includes: downstream tunnel information or indication information for updating PSA, the indication information being used to indicate: the PSA sends the end flag on a second path.

In a possible implementation manner of the eleventh aspect, the second network element is a new I-SMF or SMF.

A twelfth aspect provides a communication device comprising means for performing any of the above first to eleventh aspects or any of the possible implementations of the first to eleventh aspects for performing the steps.

In a thirteenth aspect, there is provided a communication device comprising at least one processor and a memory coupled with the processor and the memory storing program instructions which, when executed by the processor, perform the steps of any of the above first to eleventh aspects, or of any of the possible implementations of the first to eleventh aspects.

In a fourteenth aspect, a communications apparatus is provided that includes at least one processor and interface circuitry, the at least one processor configured to perform: various steps in any of the above first to eleventh aspects, or in any possible implementation of the first to eleventh aspects.

A fifteenth aspect provides a computer program product comprising a computer program which, when executed by a processor, performs the steps of any of the above first to eleventh aspects, or possible implementations of any of the first to eleventh aspects.

In a sixteenth aspect, there is provided a computer readable storage medium having stored therein a computer program for performing the steps of any of the above first to eleventh aspects, or possible implementations of any of the first to eleventh aspects, when the computer program is executed.

In a seventeenth aspect, there is provided a chip comprising: a processor for calling and running a computer program from a memory, so that a communication device on which the chip is mounted performs the steps of any of the above first to eleventh aspects, or possible implementations of any of the first to eleventh aspects.

Drawings

Fig. 1 is a schematic diagram of an exemplary communication system architecture provided in the present application.

Fig. 2 is a schematic diagram of an example MEC architecture provided in the present application.

Fig. 3 is a schematic diagram of a 5G system architecture in an ETSUN scenario provided in the present application.

Fig. 4 is a schematic flowchart of an example of the insertion of I-SMF according to the target DNAI correspondence provided in the present application.

Fig. 5 is a schematic diagram of packet transmission paths before and after switching the packet transmission path of an example PDU session provided in the present application.

Fig. 6 is a schematic diagram of an example of a communication system architecture suitable for use in the present application.

Fig. 7 is a schematic flow chart of a method for transmitting data packets in a PDU session according to an example of the present application.

Fig. 8 is a schematic flow chart of some steps in a method for transmitting data packets in a PDU session according to an example of the present application.

Fig. 9 is a schematic diagram of another example communication system architecture suitable for use in the present application.

Fig. 10 is a schematic flow chart of another example of a method for transmitting data packets in a PDU session provided herein.

Fig. 11 is a schematic flow chart of some steps in a method for transmitting data packets in a PDU session according to another example provided herein.

Fig. 12 is a schematic diagram of another example communication system architecture suitable for use in the present application.

Fig. 13 is a schematic flow chart of another example of a method for transmitting data packets in a PDU session provided herein.

Fig. 14 is a schematic flow chart of some steps in a method for transmitting data packets in a PDU session according to another example provided herein.

Fig. 15 is a schematic diagram of another example communication system architecture suitable for use in the present application.

Fig. 16 is a schematic flow chart diagram of another example of a method for transmitting data packets in a PDU session provided herein.

Fig. 17 is a schematic flow chart of some steps in a method for transmitting data packets in a PDU session according to another example provided herein.

Fig. 18 is a schematic flow chart of some steps in a method for packet transmission in another PDU session provided herein.

Fig. 19 is a schematic block diagram of a communication device of an embodiment of the present application.

Fig. 20 is a schematic block diagram of a communication device according to another embodiment of the present application.

Fig. 21 is a schematic block diagram of a communication device of an embodiment of the present application.

Detailed Description

The technical solutions in the present application will be described below with reference to the accompanying drawings.

In the description of the embodiments of the present application, unless otherwise indicated, "/" means or, for example, a/B may represent a or B; "and/or" herein is merely an association relationship describing an association object, and means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist together, and B exists alone. In addition, in the description of the embodiments of the present application, "plurality" means two or more than two.

The terms "first" and "second" are used below for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present embodiment, unless otherwise specified, the meaning of "plurality" is two or more.

Furthermore, various aspects or features of the present application may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term "article of manufacture" as used herein encompasses a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media can include, but are not limited to, magnetic storage devices (e.g., hard disk, floppy disk, or magnetic strips, etc.), optical disks (e.g., compact disk, CD, digital versatile disk, digital versatile disc, DVD, etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memory, EPROM), cards, sticks, or key drives, etc. Additionally, various storage media described herein can represent one or more devices and/or other machine-readable media for storing information. The term "machine-readable medium" can include, without being limited to, wireless channels and various other media capable of storing, containing, and/or carrying instruction(s) and/or data.

Various aspects or features of the present application can be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term "article of manufacture" as used herein encompasses a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media can include, but are not limited to, magnetic storage devices (e.g., hard disk, floppy disk, or magnetic strips, etc.), optical disks (e.g., compact disk, CD, digital versatile disk, digital versatile disc, DVD, etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memory, EPROM), cards, sticks, or key drives, etc. Additionally, various storage media described herein can represent one or more devices and/or other machine-readable media for storing information. The term "machine-readable medium" can include, without being limited to, wireless channels and various other media capable of storing, containing, and/or carrying instruction(s) and/or data.

The 5G network architecture of the evolved packet system (evolved packet system, EPS) defined by the third generation partnership project (3rd Generation Partnership Project,3GPP) is shown in fig. 1 and mainly comprises: terminal device, radio access network device, management device, gateway device and Data Network (DN). Wherein the terminal device in fig. 1 may be used to connect to an access network device deployed by an operator through a wireless air interface, and then to connect to a data network through a gateway device; the access network equipment is mainly used for realizing the functions of wireless physical layer function, resource scheduling, wireless resource management, wireless access control, mobility management and the like; the management equipment is mainly used for equipment registration, security authentication, mobility management, position management and the like of the terminal equipment; the gateway equipment is mainly used for establishing a channel with the terminal equipment, and forwarding data packets between the terminal equipment and an external data network on the channel; the data network may correspond to a plurality of different service domains, such as an IP multimedia subsystem (IP multimedia subsystem, IMS), the Internet (Internet), an Internet protocol television (Internet protocol television, IPTV), other operator service domains, etc., and is mainly used to provide a plurality of data service for terminal devices, where network devices such as servers (including servers providing multicast services), routers, gateways, etc. may be included. It should be noted that fig. 1 is only an exemplary architecture, and the network architecture may include other functional units or functional network elements besides the functional units shown in fig. 1, which is not limited in this embodiment of the present application.

In the architecture shown in fig. 1, the terminal device may be a User Equipment (UE), such as: a cell phone, a computer, a cellular phone, a cordless phone, a session initiation protocol (session initiation protocol, SIP) phone, a smart phone, a wireless local loop (wireless local loop, WLL) station, a personal digital assistant (personal digital assistant, PDA), a computer, a laptop, a handheld communication device, a handheld computing device, a satellite radio, a wireless modem card, a television Set Top Box (STB), a customer premise equipment (customer premise equipment, CPE), and/or other devices for communicating over a wireless system.

The access network device may be AN Access Network (AN)/radio access network (radio access network, RAN) device, and the network is a network comprising a plurality of 5G-AN/5G-RAN nodes. For example, the 5G-AN/5G-RAN node may be: an Access Point (AP), a Base Station (BS), a next generation Base station (nb), a Central Unit (CU), and a Distributed Unit (DU) separate the gNB, the transceiving point (transmission receive point, TRP), the transmission point (transmission point, TP), or some other access node. The embodiments of the present application are not limited, but may also be a base station (NodeB, NB) in a wideband code division multiple access (Wideband Code Division Multiple Access, WCDMA) system, an evolved NodeB (eNB or eNodeB) in an LTE system, a wireless controller in a cloud wireless access network (Cloud Radio Access Network, CRAN) scenario, or an access network device may be a relay station, an access point in a wireless fidelity technology (wireless fidelity access point, wiFi AP), a worldwide interoperability for microwave access point (worldwide interoperability for microwave access, wiMAX), a network device in a 5G network, or an access network device in a future evolved public land mobile network (public land mobile network, PLMN), etc.

The management device may include: unified data management network elements (unified data management, UDM), access and mobility management functions (access and mobility function, AMF), session management functions (session management function, SMF), policy control functions (policy control function, PCF), application functions (application function, AF), etc.

The gateway device may include a user plane function (user plane funtion, UPF). In some embodiments, the gateway device may further include: and a Branch Point (BP), an uplink classifier (Uplink Classifier, UL CL) and other functional units. These functional units may operate independently or may be combined together to implement certain control functions. For example: the AMF is mainly responsible for mobility management in mobile networks, such as user location update, user registration network, user handover, etc. The SMF is mainly responsible for session management in the mobile network, such as session establishment, modification, release, specific functions such as assigning IP addresses to users, selecting a UPF providing a message forwarding function, etc. The PCF is responsible for providing policies to the AMF, SMF, such as quality of service (quality of service, qoS) policies, slice selection policies, etc. The UDM is used to store user data such as subscription information, authentication/authorization information. The AF is responsible for providing services to the 3GPP network, such as affecting traffic routing, interacting with the PCF for policy control, etc. UPF is mainly responsible for handling user messages, such as forwarding, charging, etc.

Also for example: the AMF, SMF and PCF may be combined together as a management device for performing access control and mobility management functions such as access authentication, security encryption, location registration, etc. of the terminal device, session management functions such as establishment, release, and modification of a user plane transmission path, and functions for analyzing some slice-related data (e.g. congestion) and terminal device-related data. The UPF is used as gateway equipment to mainly complete functions of routing forwarding and the like of user plane data, such as: is responsible for filtering data messages of terminal equipment, transmitting/forwarding data, controlling rate, generating charging information and the like.

In some embodiments, in order to support selective routing of traffic to a data network in a 5G system, a session management network element may control the data path of a protocol data unit (protocol data unit, PDU) session, so that multiple interfaces may be simultaneously associated between the PDU session and the data network, i.e., multiple session anchors may exist for the same PDU session. The user plane functions (user plane funtion, UPF) that terminate these interfaces are referred to as PDU session anchor (PDU session anchor, PSA) or anchor UPF. Each anchor point of a PDU session may also provide a different entry to the same DN. Meanwhile, data splitting of uplink data to different PSAs is achieved between the access network device and the different PSAs by inserting one or more UPF network elements, which may be a Branching Point (BP) or an uplink classifier (uplink classifier, UL CL). Throughout this document, BP or UL CL may also be referred to as split point UPF network elements.

In the 5G network shown in fig. 1, the functional units may establish a connection through a next generation Network (NG) interface to implement communications, such as: the terminal equipment establishes air interface connection with the RAN equipment through a New Radio (NR) interface and is used for transmitting user plane data and control plane signaling; the terminal equipment can establish control plane signaling connection with AMF through NG interface 1 (N1 for short); AN access network device (for example, AN/RAN device) may establish a user plane data connection with the UPF through AN NG interface 3 (abbreviated as N3); the access network equipment can establish control plane signaling connection with AMF through NG interface 2 (N2 for short); the UPF can establish control plane signaling connection with the SMF through an NG interface 4 (N4 for short); the UPF can interact user plane data with the data network through an NG interface 6 (N6 for short); the AMF may establish a control plane signaling connection with the SMF through NG interface 11 (N11 for short); the SMF can establish control plane signaling connection with PCF through NG interface 7 (N7 for short); the UDM may establish a control plane signaling connection with the PCF through NG interface 25 (N25 for short);

it should be understood that the names of interfaces between network elements in the embodiments of the present application are merely exemplary, and interfaces between network elements may also be other names, which are not limited in the present application.

In order to effectively meet the requirements of high bandwidth and low latency required by the high-speed development of the mobile internet and the internet of things and reduce network load, the european telecommunication standardization institute (european telecommunication standard institute, ETSI) proposed a mobile edge computing (mobile edge computing, MEC) technology in 2014. MEC is an evolution architecture based on 5G network, and is a technology for deeply fusing access network and Internet services. The method deploys the functions of service processing and resource scheduling of an application server (application server, AS) and a mobile broadband (MBB) core network part to the network edge close to an access network together, and provides reliable and ultra-low-delay extreme service experience through service close to user processing.

Fig. 2 is a schematic diagram of an example MEC architecture provided in the present application, where the MEC is deployed at a submerged UPF (i.e., a local UPF) as compared to a DN network, as shown in fig. 2; the DN network is deployed at the remote UPF. The path (shown as solid line) for the UE to access the MEC platform is greatly shortened compared to the path (shown as dashed line) for the UE to access the DN. Thus, MEC technology can provide low latency, high bandwidth services to users.

The identification of the MEC platform is used to uniquely identify one MEC platform. In some embodiments, the identity of the MEC platform may be a data network access identity (data network access identity, DNAI) supported by a UPF network element deployed on the MEC platform or a DNAI supported by a UPF network element connected to the MEC platform, and thus, different DNAIs may represent different MEC platforms. In other words, DNAI may be used to represent the identity of the user plane path of the terminal device to access the data network. For example, the path to access MEC1 may be represented by DNAI-1, the path to access EMC2 may be represented by DNAI-2, and DNAI may be understood as the location of the MEC platform.

In the 3gpp r16 stage, a topology enhancement (enhancing topology of SMF and UPF in 5G networks,ETSUN) scenario of SMF and UPF in 5G networks is proposed. In this scenario, the SMF cannot serve the entire PLMN, and the service area (SMF SA) of the SMF refers to the sum of the service areas of all UPFs controlled by the SMF.

In the ETSUN scenario, when the UE moves out of the SMF SA, an Intermediate SMF (I-SMF) is inserted; I-SMF changes may occur when the UE moves out of the I-SMF SA and is not in the SMF SA; when the UE moves into the SMF SA, the I-SMF is removed, i.e., an update of the I-SMF occurs.

Illustratively, in 5G, the same PDU session may correspond to two SMF network elements due to different SMF managed service areas. For example: when the terminal device establishes a PDU session at location-1, the PDU session has a corresponding anchor user plane function network element (e.g., UPF 1) that is managed by the anchor SMF. When the terminal moves from the position-1 to the position-2, the user plane function network element connected with the access network equipment corresponding to the switched terminal exceeds the service area of the original anchor point SMF, and is managed by the new anchor point intermediate SMF (I-SMF). At this time, a scene in which the session corresponds to two SMFs may occur.

Fig. 3 is a schematic diagram illustrating an example of a 5G system architecture in an ETSUN scenario. In the architecture shown in FIG. 3, there are I-SMF and SMF, where the I-SMF controlled UPF is UPF1 and the SMF controlled UPF is UPF2.

When there is a demand on the network side, for example, the AF provides the PCF with the DNAI corresponding to the service, thereby triggering the SMF to establish the user plane path corresponding to the DNAI. When the MEC platform corresponding to the DNAI is not in the service range of the SMF, it is known by combining the MEC technology and ETSUN described above, in this case, the AMF inserts the I-SMF in the control plane according to the DNAI, and then inserts the I-UPF in the user plane according to the I-SMF, so as to implement setting up the user plane path corresponding to the DNAI to access the corresponding MEC platform, where the I-UPF is controlled by the I-SMF.

For the update of I-SMF, three different scenarios are mainly divided:

first: I-SMF insertion (insertion), i.e. there is a source SMF originally, and as the terminal device moves, when the terminal device is not in the service range of the source SMF, a new I-SMF (new I-SMF) is inserted, and after new I-SMF insertion, new I-SMF and SMF exist in the network architecture.

Second kind: the change or transformation of I-SMF, i.e., the original presence of a source I-SMF, may also be referred to as old or old I-SMF (old I-SMF). With the movement of the terminal device, when the terminal device is not in the service range of the source I-SMF, the I-SMF serving the terminal device is changed into a new I-SMF (new I-SMF), and new I-SMF and SMF exist in the network architecture.

Third kind: the removal (remove) of the I-SMF, that is, the original existence of the source I-SMF and the source I-SMF may also be called old or old I-SMF (old I-SMF), and as the terminal device moves, the terminal device is not in the service range of the old I-SMF, the I-SMF serving the terminal device is changed from the old I-SMF to the SMF, the source I-SMF is deleted, and the SMF exists in the network architecture.

Fig. 4 is a schematic flowchart of an example of inserting an I-SMF according to a target DNAI, and as shown in fig. 4, the flowchart includes:

s401, the PCF sends policy charging control (policy and charging control, PCC) rules to the SMF.

Optionally, the PCC rule carries (or contains) DNAI.

For example, in some embodiments, the PCF may send a policy control update notification (npcf_sm policy control_updatenotify) to the SMF over the Npcf interface, the notification carrying PCC rules therein.

S402: the SMF sends target DNAI info to the AMF. Wherein the Target DNAI info contains a Target DNAI (Target DNAI), which is used to indicate the AMF insert I-SMF.

In some embodiments, the SMF will first determine the target DNAI (target DNAI), and after determining the target DNAI, the SMF sends the target DNAI to the AMF when the SMF determines that the target DNAI cannot be served.

In some embodiments, the SMF may determine the target DNAI from the location of the terminal device, DNAI in step S401, etc.

Alternatively, when the PCC rule does not include DNAI in step S401, in S402, the target DNAI information sent by the SMF to the AMF does not include target DNAI.

For example, in some embodiments, the SMF may send a PDU Session context state notification (nsmf_pdu session_smcontextstatus notify) to the AMF, carrying the target DNAI info therein.

S403: AMF selects and inserts I-SMF (i.e., new I-SMF) according to target DNAI.

In some embodiments, S403 may also be replaced with: when the AMF determines from the target DNAI that the SMF can service the target DNAI, or when the AMF does not receive the target DNAI, the AMF deletes the I-SMF.

S404: the AMF sends a create context request to an I-SMF (new I-SMF), which carries: session identification, session management (Session management, SM) context identification (SM context ID), terminal device location information (UE location info), target DNAI, NG-RAN-unchanged indication information (indication of no NG-RAN change), etc. Where NG-RAN represents a Next Generation (NG) radio access network device.

In some embodiments, when the AMF determines to delete the I-SMF, S404 may also be replaced with: the AMF sends a create or update context request to the SMF.

For example, in some embodiments, the AMF may send a create PDU Session context request (nsmf_pdu session_createsmcontext) to the I-SMF or SMF, which carries the information in S404.

Wherein the session identifier is used to indicate the current PDU session.

The SM context ID is used to indicate the identity of the source I-SMF. Under the I-SMF insertion scene (namely, the control surface corresponding to the session is AMF and SMF, which are changed into AMF, new I-SMF and SMF after I-SMF is inserted), the SM context ID is used for pointing to the SMF; in the case of I-SMF change (change) scenario (i.e. the control plane corresponding to the session is AMF, old I-SMF, SMF; become AMF, new I-SMF, SMF after I-SMF is inserted), SM context ID is used to point to old I-SMF.

The Target DNAI is used to represent the MEC platform location, or in other words, the identity of the user plane connection to which the MEC platform corresponds is accessed.

NG-RAN unchanged indication information (indication of no NG-RAN change) for indicating that NG-RAN tunnel information (NG-RAN tunnel info) is unchanged. When the terminal equipment is in a connected state, the AMF sends the parameter to the new I-SMF.

S405, new I-SMF obtains SM context from old I-SMF (corresponding to I-SMF change scene) or SMF (corresponding to I-SMF insertion scene).

For example, in some embodiments, the new I-SMF may send a context request to old I-SMF (corresponding to the scene of I-SMF change or removal) or SMF, carrying NG-RAN-unchanged indication information (indication of no NG-RAN change), etc. Thereafter, old I-SMF or SMF returns a following response to new I-SMF, carrying NG-RAN tunnel information (NG-RAN tunnel info).

S406, new I-SMF selects new I-UPF according to target DNAI.

S407 the new I-SMF sends NG-RAN tunnel information (NG-RAN tunnel info) to the new I-UPF. Thus, a downlink path between new I-UPF and NG-RAN is established.

S408, the new I-SMF establishes a user plane path between the new I-UPF and the PSA.

And S409, the new I-SMF inserts a diversion point according to the target DNAI, for example, inserts UL CL or BP, so as to divert the service flow to the MEC platform corresponding to the target DNAI.

Fig. 5 is a schematic diagram of a packet transmission path before and after switching corresponding to the flow shown in fig. 4. The flow shown in fig. 4 may be summarized into 4 steps, i.e., the following steps 1 to 4:

in step 1, the SMF sends a new request DNAI (new requested DNAI) to the AMF, which selects new I-SMF according to DNAI.

In step 2, the AMF sends SM context ID, NG-RAN unchanged indication information (indication of no NG-RAN change), etc. to the new I-SMF. In the I-SMF change or I-SMF remove scene, the SM context ID points to a source I-SMF (SM context ID points to source I-SMF); in the I-SMF insert scenario, the SM context ID points to SMF (SM context ID points to SMF).

In step 3, new I-SMF knows NG-RAN downlink tunnel information (SM context includes additional Downlink Tunnel Info of NG-RAN).

In step 4, the new I-SMF selects a new I-UPF, and the new I-UPF sends the tunnel information of the new I-UPF to the NG-RAN, so as to establish a transmission path between the new I-UPF and the NG-RAN.

In FIG. 5, the target I-SMF represents the new I-SMF, and the target I-UPF represents the new I-UPF. Source I-SMF represents: old I-SMF (corresponding I-SMF change or remove field scene) or SMF (corresponding I-SMF insert scene). The source I-UPF represents the source I-SMF inserted (or controlled) I-UPF.

In the scenario shown in fig. 5, before step 4, the context information (UE context in NG-RAN) of the terminal device on the NG-RAN side includes Tunnel information (Tunnel Info) of source I-UPF. After step 4, the context information of the terminal device on the NG-RAN side includes Tunnel information (Tunnel Info) of the target (target) I-UPF.

As can be seen from fig. 5, for the same PDU session, the PSA can receive upstream messages from two different paths. In fig. 5, the old path is indicated by a broken line, and the new path is indicated by a solid line.

For an uplink packet (may also be referred to as an uplink packet), the user plane paths before and after the I-UPF change are respectively:

The pre-change path (called old path)) is UE→NG-RAN→old I-UPF→PSA.

The changed path (called new path)) is UE→NG-RAN→new I-UPF→PSA.

For the uplink message, the user plane paths before and after the I-UPF insertion (insertion) are respectively:

the pre-insertion path (called old path)) ue→ng-ran→psa.

The inserted path (called new path)) is UE→NG-RAN→new I-UPF→PSA.

For the uplink message, the user plane paths before and after the I-UPF removal (remove) are respectively:

the pre-removal path (called old path)) is UE→NG-RAN→old I-UPF→PSA.

The removed path (called new path)) is ue→ng-ran→psa.

It can be seen that for the uplink message of the same PDU session, in the above three cases, the PSA receives messages from two paths (the old path and the new path). When a message on a new path arrives at the PAS earlier than an old path, disorder occurs, and communication becomes problematic. For example: assuming that a PDU session includes 10 messages, the first through sixth messages are transmitted on the old path and the seventh through tenth messages are transmitted on the new path, if the PSA receives the seventh through tenth messages first, the PSA will continue to send the seventh through tenth messages to the server (e.g., the application server in the DN), and then resend the first through sixth messages received later to the server. Under normal conditions, the order of arrival of the messages at the server should be: first to tenth messages. However, in the above scenario, the order of the messages reaching the server may be: the seventh to tenth messages and the first to sixth messages, namely the messages received by the server are disordered, so that the time consumption of ordering the messages by the server is increased, the communication time delay is increased, and the communication efficiency cannot be ensured.

For a downlink packet (also referred to as a downlink packet), the user plane paths before and after the I-UPF change are respectively:

the pre-change path (called old path)) is PSA→old I-UPF→NG-RAN→UE.

The changed path (called new path)) is PSA→new I-UPF→NG-RAN→UE.

For the downlink message, the user plane paths before and after the I-UPF insertion (insertion) are respectively:

the pre-insertion path (called old path)) psa→ng-ran→ue.

The inserted path (called new path)) is PSA→new I-UPF→NG-RAN→UE.

For the downlink message, the user plane paths before and after the I-UPF removal (remove) are respectively:

the pre-removal path (called old path)) is psa→old I-upf→ng-ran→ue.

The removed path (called new path)) psa→ng-ran→ue.

It can be seen that for the downlink message of the same PDU session, in the above three cases, the NG-RAN will receive messages from both paths (old path and new path). For example: assuming that a PDU session includes 8 messages, the first to fourth messages are transmitted on the old path, the fifth to eighth messages are transmitted on the new path, if the NG-RAN receives the fifth to eighth messages first, the NG-RAN will continue to send the fifth to eighth messages to the terminal device, and then send the first to fourth messages received later to the terminal device. Under normal conditions, the messages sent to the terminal equipment by the NG-RAN are sequenced in the sequence of the front and the back: the first to eighth messages, however, in the above scenario, the order of the messages sent by the NG-RAN to the terminal device is: the fifth to eighth messages and the first to fourth messages cause disorder of the messages received by the terminal equipment, so that the time consumption of ordering the messages by the terminal equipment is increased, the communication time delay is increased, and the communication efficiency cannot be ensured.

In view of this, the present application provides a method and a communication device for packet transmission in a PDU session, where in a scenario of I-SMF update (change/insert/remove) or I-UPF update (change/insert/remove) in the PDU session, a PSA receives uplink data (or may also be referred to as an uplink packet) packets of the same PDU session from different paths, which results in a problem of packet disorder, or an access network device receives downlink data (or may also be referred to as a downlink packet) of the same PDU session from different paths, which results in a problem of packet disorder, and by using a gateway (PSA, access network device or I-UPF) to order the data packets of one PDU session from different paths, so that the uplink data packets or the downlink data packets are transmitted in a normal order, which avoids a procedure of ordering the data packets by a terminal device or a server, and thus reduces communication latency, and ensures communication efficiency.

The methods provided herein are described below in connection with specific examples.

In the following embodiments, the access network device will be described by taking NG-RAN as an example, but this should not impose any limitation on the access network device in the embodiments of the present application.

It should also be appreciated that the method provided by the embodiments of the present application may be applied in a scenario where an I-SMF update (change/insert/remove) is present, and may also be applied in a scenario where only an I-UPF update (change/insert/remove) is present. The present application is not limited herein, and will be described below taking the scenario of I-SMF update (change/insert/remove) as an example.

In various embodiments below, the old path may also be referred to as the second path and the new path may also be referred to as the first path.

Fig. 6 is a schematic diagram illustrating an exemplary scenario of a communication system provided by the present application, and fig. 7 is a schematic flowchart illustrating an exemplary method for transmitting data packets in a PDU session that may be applied to the scenario illustrated in fig. 6. In some embodiments. In the method shown in fig. 7, the same PDU session upstream packets from different paths are ordered by the PSA.

In the scenario shown in fig. 6, the solid line indicates transmission of an uplink packet on the new path, and the dotted line indicates transmission of an uplink packet on the old path, where the uplink packet on the new path and the uplink packet on the old path are uplink packets included in the same PDU session.

The transmission path of the uplink data packet on the old path is as follows: terminal equipment-NG-RAN-Source I-UPF-PSA, and the transmission path of the uplink data packet on the new path is as follows: terminal equipment→ng-ran→target I-upf→psa.

In the scenario shown in fig. 6, when no change occurs in NG-RAN:

for the I-SMF or I-UPF change (change) before the source I-UPF is old I-UPF, after the I-SMF or I-UPF change (change) the target I-UPF is new I-UPF.

For I-SMF or I-UPF insertion, the source I-UPF is the PSA, i.e., the old path becomes: terminal equipment→ng-ran→psa. After I-SMF or I-UPF insertion, the target I-UPF is new I-UPF.

For I-SMF or I-UPF removal, the source I-UPF is old I-UPF, and after I-SMF or I-UPF removal, the target I-UPF is PSA, i.e. the new path becomes: terminal equipment→ng-ran→psa.

It will be appreciated that when an NG-RAN changes, for example, from an old NG-RAN (or also referred to as a source NG-RAN) to a new NG-RAN, in the scenario shown in fig. 6, the old path is the path before the NG-RAN changes, i.e., the old path is: terminal equipment → old NG-RAN → new NG-RAN → PSA. The path after NG-RAN change, i.e. the new path is: terminal equipment→new NG-ran→psa. In the NG-RAN change process, i.e. in the NG-RAN handover process, when the new NG-RAN receives new uplink tunnel information, the new NG-RAN sends an end flag on the old path, for example, the uplink tunnel information is "PSA tunnel info". It will be appreciated that examples not related to I-UPF are illustrated herein. When referring to I-UPF, the new upstream tunnel information is referred to as I-UPF tunnel info. Wherein an Xn tunnel between the new NG-RAN and the old NG-RAN is triggered to be established by the old NG-RAN. For example, the handover request sent by the old NG-RAN to the new NG-RAN includes the old NG-RAN tunnel information, and the new NG-RAN receives the old NG-RAN tunnel information, so that an uplink tunnel (Xn tunnel) between the new NG-RAN and the old NG-RAN is established.

As shown in fig. 7, the method includes:

s701, the PCF sends PCC rules to the SMF.

Optionally, the PCC rule carries (or contains) DNAI.

S702: the SMF sends target DNAI info to the AMF. Wherein the Target DNAI info contains Target DNAI for indicating AMF insertion I-SMF.

In some embodiments, the SMF will first determine the target DNAI (target DNAI), and after determining the target DNAI, the SMF sends the target DNAI to the AMF when the SMF determines that the target DNAI cannot be served. For example, the SMF may determine the target DNAI according to the location of the terminal device, DNAI in step S701, and the like.

In some embodiments, if the PCC rule in S701 does not contain DNAI, then in S702, the target DNAI info sent by the SMF to the AMF does not contain target DNAI.

S703: AMF selects and inserts a new I-SMF (new I-SMF) according to target DNAI.

In some embodiments, S703 may also be replaced with: when the AMF determines from the target DNAI that the SMF can service the target DNAI, or when the AMF does not receive the target DNAI and does not require the I-SMF, the AMF deletes the I-SMF.

For the scene of I-SMF/I-UPF insertion (insertion) and I-SMF/I-UPF change (change), after S703, S704a to S710a are performed: as shown in fig. 8.

S704a: the AMF sends a create context request to the new I-SMF, the request carrying: session identification, session management context identification (SM context ID), terminal device location information (UE location info), target DNAI, NG-RAN (next generation RAN) unchanged indication information (indication of no NG-RAN change), etc.

Wherein the session identifier is used to indicate the current PDU session.

Target DNAI is used to represent MEC platform position.

indication of no NG-RAN change to indicate that NG-RAN tunnel information (NG-RAN tunnel info) is unchanged.

S705a: new I-SMF obtains session management context (SM context) from old I-SMF or SMF.

In some embodiments, for an I-SMF change scene: the new I-SMF may send a context request to the old I-SMF (or may be referred to as source I-SMF), carrying indication of no NG-RAN change. After receiving the context request, the old I-SMF returns a context response to the new I-SMF, wherein the response carries NG-RAN tunnel information (NG-RAN tunnel info).

In some embodiments, for I-SMF insert scenarios: the new I-SMF may send a context request to the SMF, carrying indication of no NG-RAN change in the request. After the SMF receives the request, it returns a context response to the new I-SMF, and the response carries NG-RAN tunnel info.

S706a: new I-SMF selects new I-UPF (new I-UPF) to obtain tunnel information (new I-UPF tunnel info) of new I-UPF.

S707a: the new I-SMF sends a PDU session update request or a PDU session creation request to the SMF, carrying first indication information.

In some embodiments, for an I-SMF change scenario, the new I-SMF may send a PDU Session Update Request (Nsmf_PDU session_update Request) to the SMF.

In some embodiments, for an I-SMF insert scenario, the new I-SMF may send a PDU Session creation Request (Nsmf_PDU session_CreateRequest) to the SMF.

The PDU session update request or PDU session creation request carries: the first indication information, optionally, may further carry: one or more of SM context ID, new I-UPF tunnel info, new I-SMF supported DNAI list (DNAI list supported by new I-SMF).

Optionally, as a possible implementation manner, the first indication information is used to indicate: the SMF instructs the PSA to buffer upstream packets from new I-UPF (new path) and, when the PSA receives an end marker (end marker) of an upstream packet from old I-UPF (old path), the PSA reports a message to the SMF indicating that the PSA received the end marker of the old path. The end marker is used for indicating that the uplink data packet sent on the old path is sent completely.

Alternatively, as another possible implementation manner, the first indication information may be used to indicate that the upstream data packets need to be ordered.

Alternatively, as another possible implementation manner, the first indication information may be used to indicate that the access network device is unchanged.

In some embodiments, the first indication information may be indication of no NG-RAN change, which is used to indicate that the access network device is unchanged.

In some embodiments, the first indication information may be indication of no NG-RAN change, that is, indication of no NG-RAN change may be used to indicate that the access network device is unchanged, or may be used to indicate that the uplink data packets need to be ordered.

In other embodiments, the first indication information and the indication of no NG-RAN change may be different information, respectively.

In some embodiments, when the first indication information is used to indicate that the access network device is unchanged. For example, when the first indication is indication of no NG-RAN change, the SMF may determine that the upstream packets need to be ordered according to indication of no NG-RAN change.

In some embodiments, the information that the uplink packet on the old path has been sent may be: an end marker (end marker) of an uplink packet transmitted by an old path.

S708a: the SMF sends second indication information to the PSA, the second indication information being generated based on the first indication information.

In some embodiments, the SMF may determine to transmit the second indication information to the PSA according to the first indication information in S707 a.

In some embodiments, the second indication information is used to indicate: the PSA buffers the upstream message from the new I-UPF (new path) and indicates that when the PSA receives an end marker (end marker) of an upstream packet from the old I-UPF or NG-RAN (old path), the PSA sends a report message to the SMF, which indicates that the PSA has received the end marker of the old path.

For example, the SMF may generate second indication information according to the first indication information, the second indication information indicating: the PSA buffers the upstream packet from the new path and, when the PSA receives an end marker (end marker) of the upstream packet from the old path, the PSA reports a message to the SMF indicating that the PSA has received the end marker of the upstream packet on the old path.

For the I-SMF insert scenario, the second indication information indicates: the PSA buffers upstream packets from new I-UPF (new path) and, when the PSA receives an end marker (end marker) of an upstream packet from NG-RAN (old path), the PSA sends a report message to the SMF indicating that the PSA received the end marker of the upstream packet on the old path.

For an I-SMF change scene, the second indication information indicates: the PSA buffers upstream packets from new I-UPF (new path) and, when the PSA receives an end marker (end marker) of an upstream packet from old I-UPF (old path), the PSA reports a message to the SMF indicating that the PSA received the end marker of the upstream packet on the old path.

In some embodiments, the second information indication may be an N4 rule (N4 rule).

S709a: the SMF returns a PDU session update response or a PDU session creation response to the new I-SMF.

In some embodiments, the PDU session update response or PDU session creation response comprises: tunnel information for new I-UPF (new I-UPF tunnel info), etc.

S710a: new I-SMF sends a create context response message to AMF, the response message carrying: PSA tunnel info (PSA tunnel info).

Optionally, the response information further includes third indication information. The third indication information is used for indicating an end marker (end marker) of the uplink data packet sent by the NG-RAN on the old path.

In some embodiments, the third indication information may be indication of no NG-RAN change, and in other embodiments, the third indication information and indication of no NG-RAN change may be different information, respectively.

In some embodiments, the response (information) includes N2 SM info, and the N2 SM info includes the new I-UPF tunnel info and the third indication information described above.

After step S710a, S711 to S715 are performed as shown in fig. 7.

For the scenario of I-SMF/I-UPF removal (removal), after S703, S704b through S708b are performed, as shown in FIG. 8.

S704b, the AMF sends an update context request to the SMF. The request carries: session identification, session management context identification (SM context ID), terminal device location information (UE location info), target DNAI, NG-RAN (next generation RAN) unchanged indication information (indication of no NG-RAN change), etc.

Optionally, the update context request may further include indication information, where the indication information is used to indicate that the uplink data packets need to be ordered.

In some embodiments, the indication information may be indication of no NG-RAN change, that is, indication of no NG-RAN change may be used to indicate that the access network device is unchanged, or may be used to indicate that the uplink data packets need to be ordered.

In other embodiments, the indication information and indication of no NG-RAN change may be different information, respectively.

In some embodiments, when the indication information is not carried in the request, and the indication of no NG-RAN change is not used to indicate that the uplink data packet needs to be ordered, the SMF may determine that the uplink data packet needs to be ordered according to ndication of no NG-RAN change.

S705b, the SMF obtains SM context from old I-SMF.

S706b, SMF selects new I-UPF to obtain I-UPF tunnel info.

It should be understood that S706b is an optional step, and when the flow does not include S706b, the new path becomes: terminal equipment NG-RAN PSA, and in this embodiment, the case where the SMF is not inserted into the I-UPF will be described.

S707b, the SMF sends a message to the PSA. The message carries fourth indication information, and the fourth indication information is used for indicating: the PSA buffers the upstream packet from the NG-RAN (new path) and indicates that the PSA has received an end marker (end marker) from the old I-UPF (old path), and the PSA reports a message to the SMF indicating that the PSA has received the end marker of the upstream packet on the old path. In some embodiments, the message may be an end of upstream packet flag on the old path. Wherein, the end mark (end marker) of the uplink data packet on the old path indicates that the uplink data packet on the old path has been sent.

In some embodiments, the SMF may determine to send fourth indication information to the PSA according to the indication information from the AMF in S704 b.

In some embodiments, the SMF may send an N4 rule (N4 rule) to the PSA, the N4 rule containing the fourth indication information.

S708b, the SMF sends update context response information to the AMF, the response information carrying: new I-UPF tunnel info.

Optionally, the response information further includes fifth indication information. Wherein, the fifth indication information is used for indicating the NG-RAN to send an end mark (end marker) on the old path.

In some embodiments, the fifth indication information may be indication of no NG-RAN change, and in other embodiments, the fifth indication information and indication of no NG-RAN change may be different information, respectively.

In some embodiments, the response (information) includes N2 SM info, and the N2 SM info includes PSA tunnel info and fifth indication information described above.

After S708b, S711 to S715 are performed as shown in fig. 7.

S711, the AMF sends a message (for example, an N2 message) to the NG-RAN, where the message carries: the fifth indication information in S708b and at least one of new I-UPF tunnel info, or the third indication information in S710a and at least one of PSA tunnel info.

S712: the NG-RAN sends an end marker on the old path.

It may be appreciated that when step S711 does not include the fifth indication information or the third indication information, the NG-RAN may update the uplink path information according to the received new I-UPF tunnel info or PSA tunnel info. For example, the NG-RAN updates the upstream path from old I-UPF to new I-UPF or PSA based on receipt of new I-UPF tunnel info or PSA tunnel info, and sends an end flag on the old path.

When step S711 contains the fifth instruction information or the third instruction information, the NG-RAN transmits an end flag on the old path according to the fifth instruction information or the third instruction information.

S713: when the PSA receives an end marker on the old path, the PSA reports a message to the SMF according to the second indication information in step S708a or the fourth indication information in step S707b, where the message is used to indicate that the PSA has received the end marker of the upstream packet on the old path.

In some embodiments, the message reported by the PSA to the SMF is: an end marker (end marker) of an upstream packet transmitted on an old path.

S714: the SMF sends an updated message (e.g., N4 rule) to the PSA indicating: the PSA sends out buffered upstream packets from the new path (new path), i.e. onto the N6 interface.

S715: the PSA sends the buffered upstream packets from the new path (new path) based on the message.

It will be appreciated that for upstream packets on the old path, the PSA sends the packet to the server in the normal flow, i.e. after receiving the upstream packet from the old path.

According to the method for transmitting the data packets in the PDU session, the PSA is used for ordering the received uplink data packets from the same PDU session on the new path and the old path, before the PSA receives the indication information which indicates that the uplink data packets are sent on the old path, the PSA caches the uplink data packets received on the new path, after the PSA receives the indication information which indicates that the uplink data packets are sent on the old path, the PSA caches the uplink data packets received on the new path before sending, so that the uplink data packets in one PDU session can be sent according to the normal sequence, the ordering time of the server on the uplink data packets is saved, and the communication efficiency is guaranteed.

Fig. 9 is a schematic diagram illustrating a scenario of a communication system provided in the present application, and fig. 10 is a schematic flowchart illustrating a method for transmitting data packets in a PDU session in the scenario illustrated in fig. 9. In some embodiments. In the method shown in fig. 10, the same PDU session upstream packets from different paths are ordered by new I-UPF or PSA.

In the scenario shown in fig. 9, as in the diagram a in fig. 9, the solid line indicates the transmission path of the upstream packet on the new path, the broken line indicates the transmission path of the upstream packet on the old path, and the diagram a in fig. 9 indicates the scenario in which the I-UPF exists on the old path. In fig. 9 b, the solid line indicates the transmission path of the uplink packet on the new path, the broken line indicates the transmission path of the uplink packet on the old path, and fig. 9 b shows a scenario in which the I-UPF is not present on the old path.

For the scenario shown in a diagram in fig. 9, the transmission path of the uplink packet on the old path is: terminal equipment→ng-ran→source I-upf→target I-upf→psa. The transmission path of the uplink data packet on the new path is: terminal equipment→ng-ran→target I-upf→psa. The same PDU session upstream packets from both the new path and the old path are ordered by the target I-UPF.

For the scenario shown in b-chart in fig. 9, the transmission path of the upstream packet on the old path is: terminal equipment→ng-ran→psa→target I-upf→psa. The transmission path of the uplink data packet on the new path is: terminal equipment→ng-ran→target I-upf→psa. The same PDU session upstream packets from both the new path and the old path are ordered by the target I-UPF.

The target I-UPF is new I-UPF. The source I-UPF is old I-UPF.

As shown in fig. 10, the method includes:

s1001, the PCF sends PCC rules to the SMF.

Optionally, the PCC rule comprises DNAI.

S1002: the SMF sends target DNAI info to the AMF. Wherein the Target DNAI info contains a Target DNAI (Target DNAI), which is used to indicate the AMF insert I-SMF.

In some embodiments, the SMF may determine the target DNAI from the location of the terminal device, DNAI in step S1001, and the like.

Alternatively, when the PCC rule in step S1001 does not include DNAI, in S1002, the target DNAI information sent by the SMF to the AMF does not include target DNAI.

S1003: AMF selects and inserts a new I-SMF (new I-SMF) according to target DNAI.

In some embodiments, S1003 may also be replaced with: when the AMF determines from the target DNAI that the SMF can service the target DNAI, or when the AMF does not receive the target DNAI and does not require the I-SMF, the AMF deletes the I-SMF.

For the scene of I-SMF/I-UPF insertion (insertion) and I-SMF/I-UPF change (change), after S1003, S1004a to S1008a are performed as shown in FIG. 11.

S1004a: the AMF sends a create context request to the new I-SMF, the request carrying: session identification, session management context identification (SM context ID), terminal device location information (UE location info), target DNAI, NG-RAN (next generation RAN) unchanged indication information (indication of no NG-RAN change), etc.

Optionally, the create context request may further include indication information, where the indication information is used to indicate that the upstream data packets need to be ordered.

In some embodiments, the indication information may be indication of no NG-RAN change, that is, indication of no NG-RAN change may be used to indicate that the access network device is unchanged, or may be used to indicate that the uplink data packets need to be ordered. In this application, the "ordering the upstream data packets" may also be described as "ordering the upstream data packets".

In some embodiments, when the creation context request does not carry the indication information, and indication of no NG-RAN change is not used to indicate that the uplink data packet needs to be ordered, the new I-SMF may determine that the uplink data packet needs to be ordered according to indication of no NG-RAN change.

Wherein the session identifier is used to indicate the current PDU session.

Target DNAI is used to represent MEC platform position.

S1005a: new I-SMF obtains session management context (SM context) from old I-SMF or SMF.

In some embodiments, for an I-SMF change scene: the new I-SMF may send a context request to the old I-SMF, carrying indication of no NG-RAN change.

Alternatively, as one possible implementation: the context request may further include indication information, where the indication information is used to instruct the old I-SMF to determine to establish a forwarding tunnel, where the forwarding tunnel is used to forward the uplink data packet, and two possible implementations exist as follows:

mode one: the indication information may be indication of no NG-RAN change, that is, indication of no NG-RAN change may be used to indicate old I-SMF to determine to establish a forwarding tunnel.

Mode two: the indication information and indication of no NG-RAN change may be different information, respectively.

Alternatively, as another possible implementation: the context request may include indication information indicating that the upstream data packets need to be ordered. There are three possible ways:

Mode one: the indication information may be indication of no NG-RAN change, that is, indication of no NG-RAN change may be used to indicate that the access network device is unchanged, or may be used to indicate that the uplink data packets need to be ordered.

Mode three: when the context request does not carry the indication information and indication of no NG-RAN change is not used to indicate that the uplink data packets need to be ordered, old I-SMF may determine that the uplink data packets need to be ordered according to ndication of no NG-RAN change.

After receiving the context request, the old I-SMF returns a context response to the new I-SMF, where the context response carries NG-RAN tunnel information (NG-RAN tunnel info) and a forwarding indication (forwarding indication). Wherein the forwarding indication is used for indicating to establish a forwarding tunnel between new I-UPF and old I-UPF. Optionally, the context response may further carry sixth indication information, where the sixth indication information is used to indicate that the forwarding tunnel is used to forward the uplink data packet.

In some embodiments, when the received context request by the old I-SMF includes indication of no NG-RAN change, the forwarding indication is included in the context response returned by the old I-SMF (forwarding indication).

In some embodiments, for the I-SMF insertion scenario: the new I-SMF may send a context request to the SMF, carrying indication of no NG-RAN change in the request.

Alternatively, as one possible implementation: the context request may further include indication information, where the indication information is used to instruct the SMF to determine to establish a forwarding tunnel, where the forwarding tunnel is used to forward the uplink data packet, and two possible implementations exist as follows:

mode one: the indication information may be indication of no NG-RAN change, that is, indication of no NG-RAN change may be used to instruct the SMF to determine to establish a forwarding tunnel.

Mode three: when the creation context request does not carry the indication information, and the indication of no NG-RAN change is not used to indicate that the uplink data packets need to be ordered, the SMF may determine that the uplink data packets need to be ordered according to ndication of no NG-RAN change.

After the SMF receives the request, it returns a context response to the new I-SMF, and the context response carries NG-RAN tunnel info and forwarding indication (forwarding indication). Wherein the forwarding indication is used for indicating that a forwarding tunnel between new I-UPF and PAS is established. Optionally, the context response may further carry seventh indication information, where the seventh indication information is used to indicate that the forwarding tunnel is used to forward the uplink data packet.

In some embodiments, when the context request received by the SMF includes indication of no NG-RAN change, the SMF returns a context response that includes a forwarding indication (forwarding indication).

S1006a: the new I-SMF selects new I-UPF to obtain tunnel information (new I-UPF tunnel info) of the new I-UPF.

S1007a: the new I-SMF sends an N4 session establishment request to the new I-UPF, wherein the request is carried: NG-RAN tunnel info and indication information, the indication information being used for indicating: the new I-UPF buffers the upstream packet (or may also be referred to as upstream message) from the NG-RAN (new path) and upon receiving an end marker (end marker) of the upstream packet from the PSA or old I-UPF (old path), the new I-UPF reports a message to the SMF indicating that the new I-UPF received the end marker of the old path. The end marker is used for indicating that the uplink data packet sent on the old path is sent completely.

In some embodiments, the new I-SMF may determine to send the indication information in S1007a to the new I-UPF according to the indication information in S1004 a.

In some embodiments, the message reported by the new I-UPF to the SMF may be an end marker (end marker) of the upstream packet of the old path.

For the I-SMF change scenario, the upstream packet received by the new I-UPF on the old path is the upstream packet received from the old I-UPF. In the I-SMF insertion scenario, the upstream packet received by new I-UPF on the old path is the upstream packet received from PSA.

In some embodiments, the N4 session establishment request may include N4 rule, where N4 rule carries NG-RAN tunnel info and the indication information in S1007 a.

S1008a: new I-SMF sends a create context response (nsmf_pdu session_ CreateSM Response) to AMF, carrying N2 SM info. The N2 SM info contains new I-UPF tunnel info.

Optionally, the N2 SM info further includes eighth indication information. The eighth indication information is used for indicating that the NG-RAN sends an end mark (end marker) on the old path, and the end mark is used for indicating that the uplink data packet on the old path is sent completely.

In some embodiments, the eighth indication information may be indication of no NG-RAN change, that is, indication of no NG-RAN change may be used to indicate the content indicated by the eighth indication information.

In other embodiments, the eighth indication information and the indication of no NG-RAN change may be different information, respectively.

After S1008a, S1009 to S1013 are performed as shown in fig. 10.

For the scene of I-SMF/I-UPF removal (removal), after S1003, S1004b to S1008b are performed.

S1004b, the AMF sends an update context request to the SMF. The request carries: session identification, session management context identification (SM context ID), terminal device location information (UE location info), target DNAI, NG-RAN (next generation RAN) unchanged indication information (indication of no NG-RAN change), etc.

In some embodiments, when the indication information is not carried in the create context request and indication of no NG-RAN change is not used to indicate that the upstream data packets need to be ordered, the SMF may determine that the upstream data packets need to be ordered according to indication of no NG-RAN change.

S1005b, the SMF acquires SM context from old I-SMF.

In some embodiments, the SMF may send a context request to the old I-SMF, carrying indication of no NG-RAN change in the request. Upon receipt of the request, the old I-SMF sends a context response (information) to the SMF, the response (information) including: NG-RAN tunnel info, forwarding indication (forwarding indication).

Mode three: when the creation context request does not carry the indication information, and indication of no NG-RAN change is not used to indicate that the uplink data packets need to be ordered, old I-SMF may determine that the uplink data packets need to be ordered according to ndication of no NG-RAN change.

In some embodiments, when the context request received by the old I-SMF includes indication of no NG-RAN change, the forward indication is included in the context response returned by the old I-SMF (forwarding indication). Wherein the forwarding indication is used for indicating that a forwarding tunnel between the old I-UPF and the PAS is established. Optionally, the context response may further carry ninth indication information, where the ninth indication information is used to indicate that the forwarding tunnel is used to forward the uplink data packet.

S1006b: SMF selects and inserts new I-UPF.

It should be understood that S1006b is an optional step. The flow shown in fig. 10 and 11 is a case including S1006 b. When the SMF is not inserted into the new I-UPF, the new I-UPF is replaced by the PSA.

In the case where the above step includes S1006 b: s1007b is: the SMF sends an N4 session establishment request to the new I-UPF, where the session request carries indication information, where the indication information is used to instruct the new I-UPF to buffer an uplink packet from a new path (from NG-RAN), and when receiving an end flag (end marker) from the old I-UPF, the new I-UPF sends a report message to the SMF, where the report message is used to indicate that the new I-UPF has received an end flag of an uplink packet on an old path. The end marker is used for indicating that the uplink data packet sent on the old path is sent completely. In some embodiments, the SMF may determine to send the indication information in S1007b to the new I-UPF according to the indication information in S1004 b.

In the case where the above step includes S1006b, the old path is: terminal equipment-NG-RAN-old I-UPF-new I-UPF-PSA; the new path is: terminal equipment→ng-ran→new I-upf→psa.

If the above-described flow does not include S1006b, S1007b is replaced with: the SMF sends an N4 session modification request to the PSA, and carries indication information, wherein the indication information is used for indicating: the PSA is instructed to buffer upstream packets from the new path and send a report message to the SMF when an end marker (end marker) from the old path is received, the message being used to instruct the PSA to receive the end marker of the upstream packets on the old path. In some embodiments, the SMF may determine to transmit the indication information in S1007b to the PSA according to the indication information in S1004 b.

In the case where the above flow does not include S1006b, the old path is: terminal equipment- & gtNG-RAN- & gtold I-UPF- & gtPSA; the new path is: terminal equipment→ng-ran→psa.

In some embodiments, the information that the uplink packet on the old path has been sent may be an end marker.

S1008b: the SMF sends an update context response to the AMF, carrying the N2 SM info. The N2 SM Info contains new I-UPF tunnel Info.

Optionally, the update context response further includes tenth indication information. The tenth indication information is used to indicate that the NG-RAN transmits an end marker (end marker) on the old path. The end mark is used for indicating that the uplink data packet on the old path is sent completely.

In some embodiments, the tenth indication information may be indication of no NG-RAN change, that is, indication of no NG-RAN change may be used to indicate the content indicated by the tenth indication information.

In other embodiments, the tenth indication information and the indication of no NG-RAN change may be different information, respectively.

After S1008b, S1009 to S1013 are performed as shown in fig. 11.

S1009, the AMF sends an N2 message to the NG-RAN, carrying: at least one of the tenth indication information and new I-UPF tunnel info in the above step S1008b, or at least one of the eighth indication information and new I-UPF tunnel info in the step S1008 a.

S1010, the NG-RAN sends an end marker (end marker) on the old path.

The new I-UPF or PSA receives an end marker (end marker) of the upstream packet on the old path.

It should be understood that when the NG-RAN receives the tenth indication information or the eighth indication information, the NG-RAN transmits the end flag on the old path according to the tenth indication information or the eighth indication information. When the NG-RAN receives only the new I-UPF tunnel info, i.e. does not receive the tenth or eighth indication information, the NG-RAN switches the uplink path according to the new I-UPF tunnel info, the uplink path of the NG-RAN is switched from the old path to the new I-UPF, and the NG-RAN sends an end mark on the old path. Where the old path refers to the path between the NG-RAN and the old I-UPF or PSA.

For the scenario of I-SMF insertion (i.e., I-UPF insertion): the NG-RAN sends an end marker to the PSA, and the PSA sends the end marker to the new I-UPF through a forwarding tunnel of the PSA and the new I-UPF.

For the I-SMF change scenario: the NG-RAN sends an end marker to the old I-UPF, and the old I-UPF sends the end marker to the new I-UPF through a forwarding tunnel of the old I-UPF and the new I-UPF.

For the I-SMF remove scene, two cases of inserting new I-UPF and not inserting new I-UPF are included:

In the case of SMF insert new I-UPF: the NG-RAN sends an end marker to the old I-UPF, and the old I-UPF sends the end marker to the new I-UPF through a forwarding tunnel of the old I-UPF and the new I-UPF.

Without the need to insert new I-UPF: the NG-RAN sends the end marker to the old I-UPF, and the old I-UPF sends the end marker to the PSA through a forwarding tunnel of the old I-UPF and the PSA.

S1011, the New I-UPF receives the indication information (for example, end marker) indicating that the uplink data packet has been sent on the old path according to the N4 session establishment request in S1107a or 1007b, and then sends a report message to the SMF, where the report message is used to indicate that the New I-UPF has received the end mark of the old path.

In the case where the above flow does not include S1006b, S1011 is replaced with: the PSA receives the indication information (for example, end marker) indicating that the uplink packet has been sent on the old path according to the N4 session establishment request in S1107b, and then sends a report message to the SMF, where the report message is used to indicate that the PSA has received the end flag of the old path.

S1012, the SMF sends updated N4 rule to the New I-UPF to instruct the New I-UPF to send out the cached uplink message from the New path (New path), namely to the PSA.

In the case where the above flow does not include S1006b, S1012 is replaced with: the SMF sends an updated N4rule to the PSA to instruct the PSA to send out the buffered uplink message from the new path (new path), i.e. to the N6 interface.

S1013, the New I-UPF sends the cached uplink data packet from the New path according to the updated N4 rule. It will be appreciated that for upstream packets on the old path, the New I-UPF is sent in the normal flow, i.e., after receiving the upstream packet from the old path, the packet is sent to the PSA. Finally, the PSA orders the packets on the new path and the old path and then sends the packets to the server.

In the case where the above flow does not include S1006b, S1013 is replaced with: the PSA sends buffered upstream packets from the new path (new path) according to the updated N4 rule. It will be appreciated that for upstream packets on the old path, the PSA sends the packet according to the normal flow, i.e. after receiving the upstream packet from the old path.

According to the method for transmitting the data packets in the PDU session, the I-UPF or the PSA is used for sorting the received uplink data packets from the same PDU session on the new path and the old path, before the I-UPF or the PSA receives the indication information which indicates that the uplink data packets are sent on the old path and is sent completely, the I-UPF or the PSA buffers the uplink data packets received on the new path, after the I-UPF or the PSA receives the indication information which indicates that the uplink data packets are sent completely and is sent completely, the I-UPF or the PSA buffers the uplink data packets received on the new path before sending, so that the uplink data packets in one PDU session can be sent according to the normal sequence, and the sorting time of the uplink data packets by a server is saved, and the communication efficiency is guaranteed.

Fig. 12 is a schematic diagram illustrating an exemplary scenario of a communication system provided in the present application, and fig. 13 is a schematic flowchart illustrating an exemplary method for transmitting data packets in a PDU session in the scenario illustrated in fig. 12. In some embodiments. In the method shown in fig. 13, the same PDU session downstream packets from different paths are ordered by the NG-RAN.

In the scenario shown in fig. 12, the solid line indicates transmission of a downlink packet on the new path, and the dotted line indicates transmission of a downlink packet on the old path, where the downlink packet on the new path and the downlink packet on the old path are downlink packets included in the same PDU session.

The transmission path of the downlink data packet on the old path is as follows: psa→source I-upf→ng-ran→terminal device, and the transmission path of the downlink packet on the new path is: psa→target I-upf→ng-ran→terminal equipment.

For either I-SMF or I-UPF before change, the source I-UPF is old I-UPF and after I-SMF change, the target I-UPF is new I-UPF.

Before I-SMF or I-UPF insertion (insertion), the source I-UPF is the PSA, i.e. the old path becomes: psa→ng-ran→terminal equipment. After I-SMF or I-UPF insertion, the target I-UPF is new I-UPF.

For I-SMF or I-UPF removal (remove), the source I-UPF is old I-UPF, after I-SMF removal, the target I-UPF is PSA, i.e. the new path becomes: psa→ng-ran→terminal equipment.

As shown in fig. 13, the method includes:

s1301, the PCF sends PCC rules to the SMF.

Optionally, the PCC rule carries (or comprises) a DNAI.

S1302: the SMF sends target DNAI info to the AMF. Wherein the Target DNAI info contains Target DNAI for indicating AMF insertion I-SMF.

In some embodiments, the SMF will first determine the target DNAI (target DNAI), and after determining the target DNAI, the SMF sends the target DNAI to the AMF when the SMF determines that the target DNAI cannot be served. For example, the SMF may determine the target DNAI according to the location of the terminal device, DNAI in step S1301, and the like.

In some embodiments, if the PCC rule in S1301 does not contain DNAI, then in S1302, the target DNAI info sent by the SMF to the AMF does not contain target DNAI.

S1303: AMF selects and inserts a new I-SMF (new I-SMF) according to target DNAI.

In some embodiments, S1303 may also be replaced with: the AMF deletes old I-SMF when it determines from the target DNAI that the SMF can service the target DNAI, or when the AMF does not receive the target DNAI and does not need old I-SMF.

S1304: the AMF sends an N2 message to the NG-RAN, wherein the message carries eleventh indication information. The eleventh indication information is used to indicate that the NG-RAN buffers a downlink data packet (downlink message) from a non-old path (i.e., a new path) before the NG-RAN receives an end flag (end marker) on an old path. Wherein, the end mark (end marker) is used for indicating: the downstream data packet received on the old path has been received (or the downstream data packet on the old path has been sent).

When the NG-RAN receives an end marker (end marker) on the old path, the NG-RAN sends the buffered downlink data packet from the non-old path (i.e. on the new path) to the terminal device.

In some embodiments, the eleventh indication information may be indication of no NG-RAN change, that is, indication of no NG-RAN change may be used to indicate the content indicated by the eleventh indication information.

In other embodiments, the eleventh indication information and the indication of no NG-RAN change may be different information, respectively.

In some embodiments, in S1302, the information sent by the SMF to the AMF may also include the eleventh instruction information described above, in which case S1302 may be replaced by: the SMF sends a context state notification to the AMF, the notification carrying: the target DNAI info and the eleventh indication information may optionally further carry a skip indicator (skip indicator). Wherein, skip indicator is used for the instruction: when the terminal equipment is in an idle state, the AMF does not send eleventh indication information to the NG-RAN. If the context state notification sent by the SMF to the AMF includes a skip indicator, the N2 information sent by the AMF to the NG-RAN does not include the above eleventh indication information. In other words, S1304 is an optional step.

For the scenarios of I-SMF/I-UPF insertion (insertion) and I-SM/I-UPF change (change), after S1304, S1305a through S1311a are performed, as shown in FIG. 14.

S1305a: the AMF sends a create context request to the new I-SMF, the request carrying: session identification, session management context identification (SM context ID), terminal device location information (UE location info), target DNAI, NG-RAN (next generation RAN) unchanged indication information (indication of no NG-RAN change), etc.

Wherein the session identifier is used to indicate the current PDU session.

Target DNAI is used to represent MEC platform position.

indication of no NG-RAN change, which is used to indicate that NG-RAN tunnel information is unchanged. When the terminal equipment is in a connected state, the AMF sends the parameter to the new I-SMF.

S1306a, new I-SMF obtains SM context from old I-SMF (corresponding to I-SMF change scene) or SMF (corresponding to I-SMF insertion scene).

In some embodiments, for an I-SMF change scene: the new I-SMF may send a context request to the old I-SMF, carrying indication of no NG-RAN change. After the old I-SMF receives the context request, a context response is returned to the new I-SMF, wherein the response carries: NG-RAN tunnel information (NG-RAN tunnel info). The SM context comprises NG-RAN tunnel info.

In some embodiments, for the I-SMF insertion scenario: the new I-SMF may send a context request to the SMF, carrying indication of no NG-RAN change in the request. After the SMF receives the request, a context response is returned to the new I-SMF, and the context response is carried in: NG-RAN tunnel information (NG-RAN tunnel info). The SM context comprises NG-RAN tunnel info.

S1307a: the new I-SMF selects a new I-UPF (new I-UPF) and acquires tunnel information (new I-UPF tunnel info) of the new I-UPF.

S1308a: the new I-SMF sends a PDU session update request or PDU session creation request to the SMF, carrying downstream tunnel information (new I-UPF tunnel info for PSA) to update the PSA.

Alternatively, as one possible implementation: the PDU session update request or PDU session creation request may further include indication information for indicating that the downstream data packets need to be ordered. There are three possible ways:

mode one: the indication information may be new I-UPF tunnel info for PSA, that is, new I-UPF tunnel info for PSA may be used to update the downstream tunnel information of the PSA, or may be used to indicate that the downstream packets need to be ordered.

Mode two: the indication information and the downstream tunnel information for updating the PSA may be different information, respectively.

Mode three: when the PDU session update request or the PDU session creation request does not carry the indication information, and new I-UPF tunnel info for PSA is not used to indicate that the downlink data packets need to be ordered, the SMF may determine that the downlink data packets need to be ordered according to new I-UPF tunnel info for PSA.

In some embodiments, the completion of the sending of the downlink data packet on the old path may be further described as: the PSA is updated from the old path to the new path. For example, when the PSA receives new I-UPF tunnel info for PSA, the PSA's path to the old I-UPF is replaced with the PSA's path to the new I-UPF.

The SMF determines an end of transmission flag (end marker) indicating that the PSA is in the old path based on the indication information in S1308 a.

S1309a: SMF sends new I-UPF tunnel info for PSA to PSA.

The PSA determines an end-of-transmission marker (end marker) on the old path based on the new I-UPF tunnel info for PSA.

Optionally, the SMF may further send indication information to the PSA, where the indication information is used to indicate: the PSA sends an end marker (end marker) on the old path.

In some embodiments, the indication information may be new I-UPF tunnel info for PSA, that is, new I-UPF tunnel info for PSA may be used to update the downstream tunnel information of the PSA, or may be used to indicate that the PSA is sending an end marker (end marker) on the old path. Alternatively, the PSA determines the end of transmission flag on the old path based on new I-UPF tunnel info for PSA.

In other embodiments, the indication information and new I-UPF tunnel info for PSA may be different information, respectively.

After receiving new I-UPF tunnel info for PSA, the PSA sends an end flag (end marker) of the downlink data packet on the old path (i.e. to the NG-RAN or old I-UPF) when the downlink data packet on the old path is sent, and after receiving the end flag (end marker), the old I-UPF forwards the end flag (end marker) to the NG-RAN.

S1310a: the SMF sends a PDU session update response or a PDU session creation response to the new I-SMF.

S1311a: new I-SMF sends a create context response message to AMF, the response message carrying: update uplink tunnel information of NG-RAN (new I-UPF tunnel info for NG-RAN).

Wherein, new I-UPF tunnel info for NG-RAN is used for updating the uplink tunnel information of NG-RAN.

In some embodiments, the create context response (information) carries N2 SM info, which includes the information described above.

After S1311a, S1312 is performed as shown in fig. 13.

For the scenario of I-SMF/I-UPF removal (remove), after S1304, S1305b through S1309b are performed, as shown in FIG. 14.

S1305b: the AMF sends an update context request to the SMF, the request carrying: session identification, SM context ID, UE location info, target DNAI, indication of no NG-RAN change, etc.

S1306b: the SMF obtains SM context from Old I-SMF.

In some embodiments, the SMF may send a context request to the old I-SMF, carrying indication of no NG-RAN change. After receiving the context request, the Old I-SMF may return a session management context (SM context) to the SMF, where the SM context includes NG-RAN tunnel info.

S1307b: SMF selects new I-UPF to obtain new I-UPF tunnel info for PSA and new I-UPF tunnel info for NG-RAN.

The new I-UPF tunnel info for PSA is used for updating the downlink tunnel information of the PSA; the new I-UPF tunnel info for NG-RAN is used to update the uplink tunnel information of the NG-RAN.

Alternatively, as one possible implementation: the update context request sent by the AMF to the SMF may further include indication information, where the indication information is used to indicate that the downlink data packets need to be ordered. There are three possible ways:

mode one: the indication information may be indication of no NG-RAN change, that is, indication of no NG-RAN change may be used to indicate that the access network device is unchanged, or may be used to indicate that the downstream packets need to be ordered. The downlink data packets need to be ordered, which can also be described as the downlink data packets need to be ordered.

Mode three: when the AMF sends the update context request to the SMF without carrying the indication information and carrying indication of no NG-RAN change, and indication of no NG-RAN change is not used to indicate that the downlink data packets need to be ordered, the SMF may determine that the downlink data packets need to be ordered according to indication of no NG-RAN change.

It should be understood that S1307b is an optional step.

The SMF determines an end marker (end marker) indicating that the PSA is transmitting on the old path according to the indication information from the AMF.

S1308b: SMF sends to PSA: new I-UPF tunnel info for PSA.

In some embodiments, the indication information may be new I-UPF tunnel info for PSA, that is, new I-UPF tunnel info for PSA may be used to update the downstream tunnel information of the PSA, or may be used to indicate that the PSA is sending an end marker (end marker) on the old path.

After receiving new I-UPF tunnel info for PSA, the PSA sends an end flag (end marker) on the old path (i.e. to the old I-UPF) when the downlink packet on the old path is sent.

After the old I-UPF receives the end marker, the end marker is forwarded to the NG-RAN.

S1309b: the SMF sends update context response information to the AMF, the response information carrying: update uplink tunnel information of NG-RAN (new I-UPF tunnel info for NG-RAN).

After S1309b, S1312 is performed as shown in fig. 13.

S1312, when the NG-RAN receives the downlink packet of the new path before receiving the end flag (end marker) of the downlink packet (from old I-UPF or PSA) sent on the old path, the NG-RAN buffers the downlink packet (downlink packet from new I-UPF or PSA) received on the new path according to the eleventh instruction information in step S1304. Upon receiving an end marker (end marker) of a downlink packet sent on an old path, the NG-RAN sends a buffered downlink packet from a new path to the terminal device.

It can be understood that, for the downlink data packet on the old path, the NG-RAN sends the data packet to the terminal device according to the normal flow, that is, after receiving the uplink data packet from the old path.

According to the method for transmitting the data packets in the PDU session, the NG-RAN sequences the received downlink data packets from the same PDU session on the new path and the old path, before the NG-RAN receives the indication information (for example, the end marker) that the data packets sent on the old path are sent, the NG-RAN buffers the received downlink data packets on the new path, after the NG-RAN receives the indication information that the downlink data packets sent on the old path are sent, the NG-RAN buffers the received downlink data packets on the new path, and for the downlink data packets on the old path, the NG-RAN sends the downlink data packets according to the normal procedure, so that the message sequence of the PDU session is guaranteed, and the communication efficiency is guaranteed.

Fig. 15 is a schematic diagram illustrating an exemplary scenario of a communication system provided in the present application, and fig. 16 is a schematic flowchart illustrating an exemplary method for transmitting data packets in a PDU session in the scenario illustrated in fig. 15. In some embodiments. In the method shown in fig. 16, downstream packets from the same PDU session on different paths are ordered by the target I-UPF or PSA.

In the scenario shown in fig. 15, in the diagram a in fig. 15, the solid line indicates the transmission path of the downstream packet on the new path, the broken line indicates the transmission path of the downstream packet on the old path, and the diagram a in fig. 15 indicates the scenario in which the I-UPF exists on the old path. In b in fig. 15, the solid line indicates the transmission path of the downstream packet on the new path, the dotted line indicates the transmission path of the downstream packet on the old path, and the b in fig. 15 indicates a scenario in which no I-UPF exists on the old path.

For the scenario shown in a diagram in fig. 15, the transmission path of the downlink packet on the old path is: psa→source I-upf→target I-upf→ng-ran→terminal equipment. The transmission path of the downlink data packet on the new path is as follows: psa→target I-upf→ng-ran→terminal equipment. The downstream packets from the same PDU session on the new path and the old path are ordered by the target I-UPF.

For the scenario shown in b diagram in fig. 15, the transmission path of the downlink packet on the old path is: psa→ng-ran→target I-upf→ng-ran→psa→terminal equipment. The transmission path of the downlink data packet on the new path is as follows: psa→target I-upf→ng-ran→terminal equipment. The downstream packets from the same PDU session on the new path and the old path are ordered by the target I-UPF.

Wherein the target I-UPF is new I-UPF and the source I-UPF is old I-UPF.

As shown in fig. 16, the method includes:

s1601 the PCF sends a PCC rule to the SMF.

Optionally, the PCC rule carries (or comprises) a DNAI.

S1602: the SMF sends target DNAI info to the AMF. Wherein the Target DNAI info contains Target DNAI for indicating AMF insertion I-SMF.

In some embodiments, the SMF will first determine the target DNAI (target DNAI), and after determining the target DNAI, the SMF sends the target DNAI to the AMF when the SMF determines that the target DNAI cannot be served. For example, the SMF may determine the target DNAI according to the location of the terminal device, DNAI in step S1601, and the like.

In some embodiments, if the PCC rule in S1601 does not contain DNAI, then in S1602, the target DNAI info sent by the SMF to the AMF does not contain target DNAI.

S1603: AMF selects and inserts a new I-SMF (new I-SMF) according to target DNAI.

In some embodiments, S1603 may also be replaced with: the AMF deletes old I-SMF when it determines from the target DNAI that the SMF can service the target DNAI, or when the AMF does not receive the target DNAI and does not need old I-SMF.

For the scenes of I-SMF/I-UPF insertion (insertion) and I-SMF/I-UPF change (change), S1604a to S1611a are performed as shown in FIG. 17.

S1604a: the AMF sends a create context request to the new I-SMF, the request carrying: session identification, session management context identification (SM context ID), terminal device location information (UE location info), target DNAI, NG-RAN (next generation RAN) unchanged indication information (indication of no NG-RAN change), etc.

Optionally, the create context request may further include indication information, where the indication information is used to indicate that the downstream data packets need to be ordered.

In some embodiments, the indication information may be indication of no NG-RAN change, that is, indication of no NG-RAN change may be used to indicate that the access network device is unchanged, or may be used to indicate that the downstream data packets need to be ordered.

In some embodiments, when the indication information is not carried in the create context request and indication of no NG-RAN change is not used to indicate that the downstream data packets need to be ordered, the SMF may determine that the downstream data packets need to be ordered according to indication of no NG-RAN change.

S1605a: new I-SMF obtains session management context (SM context) from old I-SMF or SMF.

Alternatively, as one possible implementation: the context request may further include indication information, where the indication information is used to instruct the old I-SMF to determine to establish a forwarding tunnel, where the forwarding tunnel is used to forward the downlink data packet, and two possible implementations exist as follows:

Alternatively, as another possible implementation: the context request may include indication information for indicating that the downstream data packets need to be ordered. There are three possible ways:

mode one: the indication information may be indication of no NG-RAN change, that is, indication of no NG-RAN change may be used to indicate that the access network device is unchanged, or may be used to indicate that the downstream data packets need to be ordered.

Mode three: when the context request does not carry the indication information and indication of no NG-RAN change is not used to indicate that the downlink data packets need to be ordered, old I-SMF may determine that the downlink data packets need to be ordered according to ndication of no NG-RAN change.

After receiving the context request, the old I-SMF returns a context response to the new I-SMF, where the response carries NG-RAN tunnel information (NG-RAN tunnel info) and a forwarding indication (forwarding indication). Wherein the forwarding indication is used for indicating to establish a forwarding tunnel between new I-UPF and old I-UPF. Optionally, the context response may further carry twelfth indication information, where the twelfth indication information is used to indicate that the forwarding tunnel is used to forward the downlink data packet.

Alternatively, as one possible implementation: the context request may further include indication information, where the indication information is used to instruct the SMF to determine to establish a forwarding tunnel, where the forwarding tunnel is used to forward the downlink data packet, and two possible implementations exist as follows:

Mode three: when the context request does not carry the indication information and indication of no NG-RAN change is not used to indicate that the downlink data packets need to be ordered, the SMF may determine that the downlink data packets need to be ordered according to ndication of no NG-RAN change.

After the SMF receives the request, it returns a context response to the new I-SMF, and the response carries NG-RAN tunnel info and forwarding instruction (forwarding indication). Wherein the forwarding indication is used to indicate that a forwarding tunnel between the NG-RAN and the PSA is established. Optionally, the context response may further carry thirteenth indication information, where the thirteenth indication information is used to indicate that the forwarding tunnel is used to forward the downlink data packet.

The new I-SMF determines an indication new I-UPF according to the indication information in the S1604 a: the downstream packets from the new path (i.e., from the PSA) are buffered and when an end marker (end marker) from the old path is received, a message is reported to the SMF.

S1606a: the new I-SMF selects a new I-UPF (new I-UPF), and sends indication information to the new I-UPF, wherein the indication information is used for indicating: the new I-UPF buffers the downstream packet from the new path (i.e., from the PSA), and when receiving an end marker (end marker) from the old path, reports a message to the SMF, where the message is used to indicate that the new I-UPF has received the end marker of the downstream packet on the old path. And reporting the information that the downlink data packet on the old path is sent to the SMF by the new I-UPF. That is, when the new I-UPF receives an end flag (end marker) of a downstream packet from the PSA (for the I-SMF insertion scenario) or the old I-UPF (for the I-SMF change scenario), the new I-UPF reports to the SMF that the downstream packet on the old path has been sent.

S1607a: the new I-UPF sends response information to the new I-SMF, and the response information carries: new I-UPF tunnel info for NG-RAN, new I-UPF tunnel info for PSA, new I-UPF tunnel info for forwarding.

The new I-UPF tunnel info for PSA is used for updating the downlink tunnel information of the PSA; the new I-UPF tunnel info for NG-RAN is used for updating the uplink tunnel information of the NG-RAN; new I-UPF tunnel info for forwarding is used to establish a forwarding tunnel between new I-UPF and old I-UPF.

S1608a: the new I-SMF sends an update context request to the old I-SMF, carrying new I-UPF tunnel info for forwarding.

S1609a: the old I-SMF sends new I-UPF tunnel info for forwarding to the old I-UPF.

S1610a: the old I-UPF and the new I-UPF establish a forwarding tunnel between the new I-UPF and the old I-UPF according to the new I-UPF tunnel info for forwarding.

S1611a: new I-SMF sends a create request (I-SMF insertion scenario) or an update request (I-SMF change scenario) to SMF, where the create request or the update request carries: new I-UPF tunnel info for PSA.

Alternatively, as one possible implementation: the session update request or session creation request may further include indication information, where the indication information is used to indicate that the downstream data packets need to be ordered. There are three possible ways:

The SMF determines an end of transmission flag (end marker) indicating that the PSA is in the old path based on the indication information in S1611 a.

S1612a: SMF sends new I-UPF tunnel info for PSA to PSA.

S1613a: the SMF returns a create/update response to the new I-SMF.

S1614a: new I-SMF returns a create context response to AMF, carrying N2 SM info. The N2 SM info includes: new I-UPF tunnel info for NG-RAN.

After S1614a, S1615 to S1617 are performed as shown in fig. 16.

For the scenario of I-SMF/I-UPF removal (removal), S1604b through S1612b are performed after S1603, as shown in FIG. 18.

S1604b, the AMF sends an update context request to the SMF. The request carries: session identification, session management context identification (SM context ID), terminal device location information (UE location info), target DNAI, NG-RAN (next generation RAN) unchanged indication information (indication of no NG-RAN change), etc.

Optionally, the update context request may further include indication information, where the indication information is used to indicate that the downlink data packets need to be ordered.

S1605b, the SMF obtains SM context from old I-SMF.

In some embodiments, the SMF may send a context request to the old I-SMF, carrying indication of no NG-RAN change in the request.

Upon receipt of the request, the old I-SMF sends a context response (information) to the SMF, the response (information) including: NG-RAN tunnel info, forwarding indication (forwarding indication). Wherein the forwarding indication is used for indicating that a forwarding tunnel between PAS and old I-UPF is established.

In some embodiments, when the context request received by the old I-SMF includes indication of no NG-RAN change, the forward indication is included in the context response returned by the old I-SMF (forwarding indication).

Optionally, the context response may further carry fourteenth indication information, where the fourteenth indication information is used to indicate that the forwarding tunnel is used to forward the downlink data packet.

S1606b: SMF selects and inserts new I-UPF to obtain new I-UPF tunnel info.

Wherein S1606b is an optional step.

S1607b: the SMF sends the tunnel information (PSA tunnel info) of the PSA to the new I-UPF;

s1608b: new I-UPF returns to SMF: new I-UPF tunnel info for PSA, new I-UPF tunnel info for forwarding, new I-UPF tunnel info for NG-RAN.

The new I-UPF tunne info for PSA is used for updating the downlink tunnel information of the PSA; the new I-UPF tunne info for NG-RAN is used for updating the uplink tunnel information of the NG-RAN; new I-UPF tunne info for forwarding is used to establish a forwarding tunnel between the NG-RANF and new I-UPF.

It will be appreciated that when the SMF is not inserted into the new I-UPF, the forwarding tunnel is located between the old I-UPF and the PSA.

The SMF may determine an indication new I-UPF according to the indication information in S1604 b: the downstream packets from the new path (i.e., from the PSA) are buffered and when an end marker (end marker) from the old path is received, a message is reported to the SMF.

S1609b: the SMF sends indication information to the new I-UPF, wherein the indication information is used for indicating: the new I-UPF caches the downlink data packet from the PSA, and when the new I-UPF receives the end marker, reports a message to the SMF, wherein the message is used for indicating that the new I-UPF receives an end mark of the downlink data packet on the old path. That is, when the new I-UPF receives the end flag (end marker) of the downlink packet from the old I-UPF, the new I-UPF reports the information that the downlink packet on the old path has been sent to the SMF.

S1610b: the SMF sends new I-UPF tunnel info for forwarding to the new I-UPF to establish a forwarding tunnel between the new I-UPF and the NG-RAN.

S1611b: SMF sends new I-UPF tunnel info for PSA to PSA.

The PSA determines an end of transmission marker (end marker) on the old path according to new I-UPF tunnel info for PSA.

In some embodiments, the PSA will make downstream path updates as it receives new I-UPF tunnel info for PSA, and the old path between the PSA and old I-UPF is updated to the new path between the PSA and new I-UPF. The PSA sends an end mark (end mark) of the downlink data packet on the old path, namely, the PSA sends the end mark (end mark) of the downlink data packet to the old I-UPF, and after the old I-UPF receives the end mark (end mark), the end mark (end mark) is forwarded to the new I-UPF through a forwarding tunnel between the old I-UPF and the new I-UPF.

S1612b: the SMF returns an update context response to the AMF, carrying the N2 SM info. The N2 SM info includes: new I-UPF tunnel info for NG-RAN.

After S1612b, S1615 to S1617 are performed as shown in fig. 16.

And S1615, when the new I-UPF receives the downlink data packet from the old I-UPF or the NG-RAN, caching the downlink data packet according to the indication information in the step S1606a or the step S1609 b.

And S1616, when the new I-UPF receives an end mark (end mark) of the downlink data transmission on the old path, according to the indication information in the step S1606a or S1609b, reporting information is sent to the SMF, wherein the information is used for indicating that the new I-UPF receives the end mark of the downlink data packet on the old path.

In some embodiments, when the new I-UPF receives an end flag (end marker) of downlink data transmission from the old I-UPF (I-SMF change/remove scene) or the NG-RAN (I-SMF insert scene), the end flag (end marker) may be reported to the new I-SMF (I-SMF change/insert scene) or the SMF (I-SMF remove scene).

S1617, SMF sends updated N4 rule to new I-UPF to instruct new I-UPF to send buffered downlink data packet.

It can be understood that, for the downlink data packet on the old path, the new I-UPF is sent according to the normal flow, that is, after receiving the uplink data packet from the old path, the data packet is sent to the terminal device.

In some embodiments, when the New I-SMF receives an end marker (end marker) sent by the New I-UPF, the New I-SMF sends an updated N4 rule to the New I-UPF to instruct the New I-UPF to send the buffered downlink data packet, and sends the buffered downlink data packet to the NG-RAN, where the NG-RAN is sending the data packet to the terminal device. For the downlink data packet on the old path, the new I-UPF sends the data packet to the NG-RAN after receiving the uplink data packet from the old path, and the NG-RAN sends the data packet to the terminal device.

In the I-SMF remove scene, and when SMF is not inserted into new I-UPF, the PSA sequences the downlink data packet as follows:

when the PSA receives a downstream packet from the new path (from the N6 interface), the downstream packet is buffered.

When the PSA receives an end flag (end marker) of downlink data transmission on the old path, that is, when the PSA receives the end flag (end marker) of downlink data transmission from old I-UPF transmission, the end flag (end marker) is reported to the SMF.

The SMF sends the updated N4 rule to the PSA to instruct the PSA to send the buffered downstream packets. For the downlink data packet on the old path, the PSA sends the data packet to the terminal device according to the normal flow, i.e. after receiving the uplink data packet from the old path.

According to the method for transmitting the data packets in the PDU session, the received downlink data packets from the same PDU session on the new path and the old path are ordered through the I-UPF or the PSA, before the I-UPF or the PSA receives the indication information that the downlink data packets sent on the old path are sent, the I-UPF or the PSA buffers the downlink data packets received on the new path, after the I-UPF or the PSA receives the indication information that the downlink data packets sent on the old path are sent, the I-UPF or the PSA buffers the downlink data packets received on the new path, so that the uplink data packets in one PDU session can be guaranteed to be sent according to the normal sequence, and the communication efficiency is guaranteed.

It should be understood that the foregoing is only intended to assist those skilled in the art in better understanding the embodiments of the present application and is not intended to limit the scope of the embodiments of the present application. It will be apparent to those skilled in the art from the foregoing examples that various equivalent modifications or variations can be made, for example, in which some steps of the methods described above are not required, or in which some steps are newly added, etc. Or a combination of any two or more of the above. Such modifications, variations, or combinations are also within the scope of embodiments of the present application.

It should also be understood that the manner, condition, class and division of the embodiments in the embodiments of the present application are for convenience of description only and should not be construed as being particularly limited, and the various manners, classes, conditions and features of the embodiments may be combined without contradiction.

It should also be understood that the various numbers referred to in the embodiments of the present application are merely descriptive convenience and are not intended to limit the scope of the embodiments of the present application. The sequence numbers of the above-mentioned processes do not mean the sequence of execution sequence, and the execution sequence of each process should be determined by its functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

It should also be understood that the foregoing description of embodiments of the present application focuses on highlighting differences between the various embodiments and that the same or similar elements not mentioned may be referred to each other and are not described in detail herein for brevity.

The functional modules of each network element (including PSA, I-UPF (e.g. new I-UPF), access network device, new I-SMF, etc.) may be divided according to the method described above. For example, each function may be divided into each functional module, or two or more functions may be integrated into one processing module. The integrated modules described above may be implemented in hardware. It should be noted that, in this embodiment, the division of the modules is schematic, only one logic function is divided, and another division manner may be implemented in actual implementation.

It should be noted that, the relevant content of each step related to the above method embodiment may be cited to the functional description of the corresponding functional module, which is not described herein.

The PSA, the I-UPF, the access network device, the new I-SMF, the SMF, and the like provided in the embodiments of the present application are configured to execute the method for transmitting a data packet in any PDU session provided in the foregoing method embodiment, so that the same effect as the foregoing implementation method may be achieved. Where integrated units are employed, the PSA, I-UPF, access network device, new I-SMF, or SMF may include a processing module, a storage module, and a communication module. The processing module may be configured to control and manage actions of the network element. For example, may be used to support the network element to perform the steps performed by the processing unit. Memory modules may be used to support storage of program code, data, and the like. And the communication module can be used for supporting the communication between the network element and other devices.

Wherein the processing module may be a processor or a controller. Which may implement or perform the various exemplary logic blocks, modules, and circuits described in connection with this disclosure. A processor may also be a combination that performs computing functions, e.g., including one or more microprocessors, digital signal processing (digital signal processing, DSP) and microprocessor combinations, and the like. The memory module may be a memory. The communication module can be a radio frequency circuit, a Bluetooth chip, a Wi-Fi chip and other equipment which interact with other terminal equipment.

Fig. 19 shows a schematic block diagram of an example of a communication apparatus provided in an embodiment of the present application, where the communication apparatus 1900 may correspond to a PSA, an I-UPF, an access network device, a new I-SMF, or an SMF described in the above method embodiments. Or may be a chip or component applied to a PSA, an I-UPF, an access network device, a new I-SMF, or an SMF, and each module or unit in the communications apparatus 1900 is configured to perform each action or process performed by the PSA, the I-UPF, the access network device, the new I-SMF, or the SMF, respectively, described in the above method embodiment, as shown in fig. 19, the communications apparatus 1900 may include: a processing unit 1910 and a communication unit 1920. Optionally, the communications device 1900 may also include a storage unit 1930.

It should be understood that, for the specific process of each unit in the communications apparatus 1900 to execute the corresponding steps described above, reference is made to the descriptions of PSA, I-UPF, access network device, new I-SMF, or SMF execution steps in the foregoing embodiments in conjunction with the respective embodiments shown in fig. 6 to 18, which are not repeated herein for brevity.

Optionally, the communication unit 1920 may include a receiving unit (module) and a sending unit (module) configured to perform the steps of PSA, I-UPF, access network device, new I-SMF, or SMF receiving and sending information in the foregoing method embodiments. The storage unit 1930 is used to store instructions executed by the processing unit 1910 and the communication unit 1920. The processing unit 1910, the communication unit 1920 and the storage unit 1930 are in communication connection, the storage unit 1930 stores instructions, the processing unit 1910 is used for executing the instructions stored by the storage unit, and the communication unit 1920 is used for executing specific signal transceiving under the driving of the processing unit 1910.

It is to be appreciated that the communication unit 1920 may be a transceiver, an input/output interface, or interface circuitry, etc., the storage unit may be a memory, and the processing unit 1910 may be implemented by a processor. Fig. 20 is a schematic block diagram of another example communication apparatus provided herein, and as shown in fig. 20, the communication apparatus 2000 may include a processor 2010, a memory 2020, a transceiver 2030 and a bus system 2040. The various components of the communications device 2000 are coupled together by a bus system 2040, where the bus system 2040 may include a power bus, control bus, status signal bus, and the like, in addition to a data bus. But for clarity of illustration, the various buses are labeled as bus system 2040 in fig. 20. For ease of illustration, fig. 20 is only schematically drawn.

It should also be appreciated that the communications apparatus 2000 of fig. 20 can be a PSA, an I-UPF, an access network device, a new I-SMF, or an SMF, or the PSA, I-UPF, access network device, new I-SMF, or SMF can comprise the communications apparatus 2000 of fig. 20.

The communications apparatus 1900 of fig. 19 or the communications apparatus 2000 of fig. 20 can implement the steps performed by the PSA, I-UPF, access network device, new I-SMF, or SMF in the embodiments illustrated in fig. 6-18 described above. Similar descriptions can be made with reference to the descriptions in the corresponding methods previously described. In order to avoid repetition, a description thereof is omitted.

Embodiments of the present application also provide a chip system, as shown in fig. 21, that includes at least one processor 2110 and at least one interface circuit 2120. The processor 2110 and the interface circuit 2120 may be interconnected by wires. For example, interface circuit 2120 may be used to receive signals from other devices. For another example, interface circuit 2120 may be used to send signals to other devices. The interface circuit 2120 may, for example, read instructions stored in a memory and send the instructions to the processor 2110. The instructions, when executed by the processor 2110, may cause the chip system to perform the various steps performed by the PSA, I-UPF, access network device, new I-SMF, or SMF in the embodiments described above. Of course, the chip system may also include other discrete devices, which are not specifically limited in this embodiment of the present application.

It should also be understood that the division of the units in the above apparatus is merely a division of a logic function, and may be fully or partially integrated into a physical entity or may be physically separated. And the units in the device can be all realized in the form of software calls through the processing element; or can be realized in hardware; it is also possible that part of the units are implemented in the form of software, which is called by the processing element, and part of the units are implemented in the form of hardware. For example, each unit may be a processing element that is set up separately, may be implemented as integrated in a certain chip of the apparatus, or may be stored in a memory in the form of a program, and the functions of the unit may be called and executed by a certain processing element of the apparatus. The processing element, which may also be referred to herein as a processor, may be an integrated circuit with signal processing capabilities. In implementation, each step of the above method or each unit above may be implemented by an integrated logic circuit of hardware in a processor element or in the form of software called by a processing element. In one example, the unit in any of the above apparatuses may be one or more integrated circuits configured to implement the above methods, for example: one or more application specific integrated circuits (application specific integrated circuit, ASIC), or one or more digital signal processors (digital signal processor, DSP), or one or more field programmable gate arrays (field programmable gate array, FPGA), or a combination of at least two of these integrated circuit forms. For another example, when the units in the apparatus may be implemented in the form of a scheduler of processing elements, the processing elements may be general-purpose processors, such as a central processing unit (central processing unit, CPU) or other processor that may invoke the program. For another example, the units may be integrated together and implemented in the form of a system-on-a-chip (SOC).

The embodiment of the application also provides a device which is contained in the PSA, the I-UPF, the access network equipment, the new I-SMF or the SMF, and has the function of realizing the PSA, the I-UPF, the access network equipment, the new I-SMF or the SMF in any one of the methods. The functions can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes at least one module or unit corresponding to the functions described above. For example, a detection module or unit, a display module or unit, a determination module or unit, a calculation module or unit, and the like.

The embodiment of the application also provides a system for transmitting the data packets in the PDU session, which comprises: PSA, I-UPF, access network device, new I-SMF, terminal device, server, etc. provided in the above method embodiments.

The embodiments of the present application also provide a computer readable storage medium for storing a computer program code, where the computer program includes instructions for executing the method for transmitting data packets in any one of the PDU sessions provided in the embodiments of the present application. The readable medium may be read-only memory (ROM) or random access memory (random access memory, RAM), which the embodiments of the present application do not limit.

The present application also provides a computer program product comprising instructions that, when executed, cause a PSA, I-UPF, access network device, new I-SMF, or SMF to perform corresponding operations corresponding to the above methods.

The embodiment of the application also provides a chip in the communication device, which comprises: a processing unit, which may be, for example, a processor, and a communication unit, which may be, for example, an input/output interface, pins or circuitry, etc. The processing unit may execute computer instructions to cause the communication device to perform any of the methods for transmitting data packets in a PDU session provided in the embodiments of the present application.

Optionally, the computer instructions are stored in a storage unit.

Alternatively, the storage unit is a storage unit in the chip, such as a register, a cache, etc., and the storage unit may also be a storage unit in the terminal located outside the chip, such as a ROM or other type of static storage device that can store static information and instructions, a random RAM, etc. The processor mentioned in any of the above may be a CPU, microprocessor, ASIC, or one or more integrated circuits for controlling the program execution of the method of packet transmission in the PDU session described above. The processing unit and the storage unit may be decoupled and respectively disposed on different physical devices, and the respective functions of the processing unit and the storage unit are implemented by wired or wireless connection, so as to support the system chip to implement the various functions in the foregoing embodiments. Alternatively, the processing unit and the memory may be coupled to the same device.

The method for transmitting data packets in a PDU session, PSA, I-UPF, access network device, new I-SMF, computer-readable storage medium, computer program product, or chip provided in this embodiment are all used to execute the corresponding method provided above, so the benefits achieved by the method may refer to the benefits in the corresponding method provided above, and are not repeated herein.

It will be appreciated that the memory in embodiments of the present application may be either volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. The nonvolatile memory may be a ROM, a Programmable ROM (PROM), an erasable programmable EPROM (EPROM), an electrically erasable programmable EPROM (EEPROM), or a flash memory, among others. The volatile memory may be RAM, which acts as external cache. There are many different types of RAM, such as Static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous Link DRAM (SLDRAM), and direct memory bus RAM (DR RAM).

Various objects such as various messages/information/devices/network elements/systems/devices/actions/operations/processes/concepts may be named in the present application, and it should be understood that these specific names do not constitute limitations on related objects, and that the named names may be changed according to the scenario, context, or usage habit, etc., and understanding of technical meaning of technical terms in the present application should be mainly determined from functions and technical effects that are embodied/performed in the technical solution.

In the various embodiments of the application, if there is no specific description or logical conflict, terms and/or descriptions between the various embodiments are consistent and may reference each other, and features of the various embodiments may be combined to form new embodiments according to their inherent logical relationships.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

The methods in the embodiments of the present application may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are performed in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer program or instructions may be stored in or transmitted across a computer-readable storage medium. The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server that integrates one or more available media.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

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

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a readable storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned readable storage medium includes: a usb disk, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk, etc.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method for transmitting data packets in a PDU session, the method comprising:

the PDU session anchor PSA receives first indication information sent by a session management function network element SMF, wherein the first indication information is used for indicating: the PSA caches the uplink data packet received on the first path, and when receiving an end mark from the second path, sends a message to the SMF, wherein the message is used for indicating that the PSA receives the end mark, the end mark is used for indicating that the transmission of the uplink data packet on the second path is ended, and the uplink data packet on the first path and the uplink data packet on the second path are uplink data packets of the same PDU session;

after the PSA receives the end mark, the PSA sends the message to the SMF;

the PSA receives second indication information from the SMF, wherein the second indication information is used for indicating the PSA to send the cached uplink data packet;

the PSA sends an uplink data packet cached on the first path according to the second indication information;

the transmission sequence of the uplink data packet on the first path is as follows: terminal equipment, access network equipment, new intermediate user plane function network element I-UPF, the PSA, or terminal equipment, access network equipment, the PSA;

The transmission sequence of the uplink data packet on the second path is as follows: terminal equipment, access network equipment, source I-UPF, the PSA, or terminal equipment, access network equipment, the PSA.

2. The method according to claim 1, wherein the method further comprises:

and when the PSA receives the uplink data packet from the second path, the PSA sends the uplink data packet from the second path.

3. The method of claim 1 or 2, wherein the PSA receiving the end-of-range indicator comprises:

the PSA receives the end flag from the access network device.

4. A method for transmitting data packets in a PDU session, the method comprising:

the SMF sends first indication information to the PSA, wherein the first indication information is used for indicating: the PSA caches the uplink data packet received on the first path, and when receiving an end mark from the second path, sends a message to the SMF, where the message is used to indicate that the PSA receives the end mark, and the end mark is used to indicate that the transmission of the uplink data packet on the second path is ended, and the uplink data packet on the first path and the uplink data packet on the second path are uplink data packets of the same PDU session;

The SMF receives the message sent by the PSA;

the SMF sends second indication information to the PSA, wherein the second indication information is used for indicating the PSA to send the cached uplink data packet;

5. The method of claim 4, wherein before the SMF sends the first indication information to the PSA, the method further comprises:

the SMF receives first information from an access and mobility management function (AMF) or a new intermediate session management function (network element I-SMF);

the SMF determines to send the first indication information to the PSA according to the first information;

wherein the first information includes: the access network equipment is unchanged in indication information or third indication information, wherein the third indication information is used for indicating the sorting of the uplink data packets.

6. The method according to claim 4 or 5, characterized in that the method further comprises:

and the SMF sends fourth indication information to AMF or access network equipment, wherein the fourth indication information is used for indicating the access network equipment to send the ending mark on the second path.

7. A method for transmitting data packets in a PDU session, the method comprising:

the access network equipment receives second information sent by an AMF network element;

the access network equipment sends an end mark on a second path according to the second information, wherein the end mark is used for indicating the end of the transmission of the uplink data packet on the second path;

the access network equipment sends an uplink data packet on a first path;

the transmission sequence of the uplink data packet on the first path is as follows: terminal equipment, access network equipment, new intermediate user plane function network element I-UPF, PSA, or terminal equipment, access network equipment, PSA;

8. The method of claim 7, wherein the second information comprises:

at least one of the tunnel information of the new I-UPF, the tunnel information of the PSA, the fourth indication information, or the indication information of unchanged access network equipment;

the fourth indication information is used for indicating the access network device to send the end mark on the second path.

9. A method for transmitting data packets in a PDU session, the method comprising:

the access network device receives fifth indication information from the AMF, where the fifth indication information is used to indicate: before the access network equipment receives the end mark on the second path, the access network equipment caches the downlink data packet from the first path;

the access network device caches the downlink data packet from the first path before receiving the end mark on the second path according to the fifth indication information, wherein the downlink data packet on the first path and the downlink data packet on the second path are downlink data packets of the same PDU session, and the end mark is used for indicating that the transmission of the downlink data packet on the second path is ended;

the access network equipment sends the downlink data packet received on the second path to the terminal equipment;

The access network equipment sends the cached downlink data packet to the terminal equipment when the ending mark is received on the second path;

the transmission sequence of the downlink data packet on the first path is as follows: PSA, new I-UPF, the access network device, and the terminal device, or PSA, the access network device, and the terminal device, where a transmission sequence of the downlink data packet on the second path is sequentially: PSA, source I-UPF, the access network device, terminal device, or PSA, the access network device, terminal device.

10. The method of claim 9, wherein the fifth indication information comprises:

indicating information that the access network equipment is unchanged.

11. The method according to claim 9 or 10, wherein the access network device receiving the end flag on the second path comprises:

the access network device receives the end tag from the PSA on the second path.

12. A method for transmitting data packets in a PDU session, the method comprising:

the PSA receiving third information from the SMF;

the PSA sends an end mark on a second path according to the third information, wherein the end mark is used for indicating the end of the transmission of the downlink data packet on the second path;

The transmission sequence of the downlink data packet on the first path is as follows: PSA, new I-UPF, access network device, terminal device, or PSA, access network device, terminal device, where the transmission sequence of the downlink data packet on the second path is sequentially: PSA, source I-UPF, access network device, terminal device, or PSA, access network device, terminal device, where the downstream data packet on the first path and the downstream data packet on the second path are downstream data packets of the same PDU session.

13. The method of claim 12, wherein the third information comprises:

downlink tunnel information or indication information for updating PSA, where the indication information is used to indicate: the PSA sends the end flag on a second path.

14. A method for transmitting data packets in a PDU session, the method comprising:

the SMF receives fourth information from the AMF or the new I-SMF;

the SMF sends third information to the PSA according to the fourth information, wherein the third information is used for indicating: the PSA sends an end mark on a second path, wherein the end mark is used for indicating the end of the transmission of the downlink data packet on the second path;

15. The method of claim 14, wherein the fourth information comprises: the indication information that the access network device is unchanged or the indication information for indicating the ordering of the downlink data packets.

16. A communication device comprising a processor and a memory for storing instructions, the processor for reading the instructions to perform the method of any one of claims 1 to 8 or the method of any one of claims 9 to 15.

17. A computer readable storage medium, characterized in that the computer readable storage medium has stored therein a computer program comprising program instructions which, when executed by a processor, cause the processor to perform the method of any of claims 1 to 8 or the method of any of claims 9 to 15.

18. A chip, comprising: a processor for calling and running a computer program from a memory, causing a communication device on which the chip is mounted to perform the method of any one of claims 1 to 8 or the method of any one of claims 9 to 15.