Method and communication apparatus for packet transmission in pdu session

Abstract

The application provides a method and a communication device for data packet transmission in a PDU session. In a scenario of I-SMF update (change / insertion / removal) or I-UPF update (change / insertion / removal) in the PDU session, the PSA receives uplink messages of the same PDU session from different paths, which causes the problem of uplink message disorder, or the access network device receives downlink messages of one PDU session from different paths, which causes the problem of downlink message disorder. By using a gateway (for example, PSA, access network device or I-UPF) to sort data packets of the same PDU session from different paths, the uplink data packets or the downlink data packets are transmitted in the normal order, the process of sorting data packets by a terminal device or a server is avoided, the communication delay is reduced, and the communication efficiency is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of communication, and more particularly, to a method for transmitting data packets in a PDU session and a communication device. BACKGROUND

[0002] In 3GPP, the location of the edge computing platform supported by the session management function (SMF) network element may be limited. When the location of the edge computing platform accessed by the terminal device is not within the support range of the SMF, an intermediate SMF (I-SMF) is inserted; when the location of the edge computing platform accessed by the terminal device is not within the support range of the I-SMF, I-SMF change occurs; when the location of the edge computing platform accessed by the terminal device is within the support range of the SMF, the I-SMF is removed; in these scenarios, the I-SMF is updated. Due to the update of the I-SMF, the intermediate user plane function (UPF) (I-UPF) controlled or managed by the I-SMF is also updated (changed / inserted / removed). Thus, for the same protocol data unit (PDU) session of the terminal device, the data packets in the same PDU session come from both the path before the I-UPF update and the path after the I-UPF update.

[0003] For example, for uplink data packets, the PDU session anchor (PSA) receives data packets from two paths and sends the data packets from the two paths to the server respectively. For the server, the data packets received from the path before the I-UPF update need to be received earlier in time sequence than the data packets received from the path after the I-UPF update. Since the data packets from the two paths arrive at the PSA at different times, when the data packets from the path before the I-UPF update arrive at the PSA later than the data packets from the path after the I-UPF update, the PSA directly sends the data packets from the two paths to the server, causing the data packets received from the path before the I-UPF update to be received later in time sequence than the data packets received from the path after the I-UPF update, thereby causing the data packets received by the server to be out of order, increasing the time for the server to sort the data packets, reducing communication efficiency, and leading to a decrease in user experience.

[0004] For downlink data packets, the access network device receives data packets from two paths and sends the data packets from the two paths to the terminal device. For the terminal device, the data packets received from the path before the I-UPF update are earlier in time than the data packets received from the path after the I-UPF update. Because the data packets from the two paths arrive at the access network device at different times, when the data packets from the path before the I-UPF update arrive at the access network device later than the data packets from the path after the I-UPF update, the access network device directly sends the data packets from the two paths to the terminal device, causing the data packets received by the terminal device from the path before the I-UPF update to be later in time than the data packets received from the path after the I-UPF update, thereby causing the data packets received by the terminal device to be out of order, increasing the time for the terminal device to sort the data packets, reducing communication efficiency, and leading to a decrease in user experience. SUMMARY

[0005] The present application provides a method and a communication device for data packet transmission in a PDU session. In the scenario of I-SMF update (change / insertion / removal) or I-UPF update (change / insertion / removal) in a PDU session, the data packets from a PDU session in different paths are sorted by using a gateway (PSA, access network device, or I-UPF), so that the uplink data packets or downlink data packets are transmitted in the normal order. The process of sorting the data packets by the terminal device or server is avoided, the communication delay is reduced, and the communication efficiency is ensured.

[0006] In a first aspect, a method for data packet transmission in a PDU session is provided. The method includes: receiving, by a PSA, first indication information sent by an SMF, the first indication information being used to indicate that the PSA buffers uplink data packets received on a first path, and, upon receiving an end marker from a second path, sending a message to the SMF, the message being used to indicate that the PSA has received the end marker, the end marker being used to indicate that the transmission of uplink data packets on the second path is complete, the uplink data packets on the first path and the uplink data packets on the second path being uplink data packets of the same PDU session; sending, by the PSA, the message to the SMF upon receiving the end marker; receiving, by the PSA, second indication information from the SMF, the second indication information being used to indicate that the PSA sends the buffered uplink data packets; and sending, by the PSA, the uplink data packets buffered on the first path according to the second indication information, wherein the transmission order of the uplink data packets on the first path is in turn: a terminal device, an access network device, a new I-UPF, and the PSA, or a terminal device, an access network device, and the PSA, and wherein the transmission order of the uplink data packets on the second path is in turn: a terminal device, an access network device, a source I-UPF, and the PSA, or a terminal device, an access network device, and the PSA.

[0007] The method for transmitting data packets in a PDU session provided in the first aspect comprises the following steps: a PSA sorts uplink data packets received from a new path (a first path) and an old path (a second path) of a same PDU session; before the PSA receives indication information sent by the old path and indicating that the uplink data packets have been sent, the PSA buffers the uplink data packets received from the new path; after the PSA receives the indication information sent by the old path and indicating that the uplink data packets have been sent, the PSA sends the buffered uplink data packets received from the new path, so that the uplink data packets in a PDU session can be sent in a normal order, thereby saving the sorting time of the server for the uplink data packets and ensuring the communication efficiency.

[0008] In a possible implementation manner of the first aspect, the method further comprises: when the PSA receives the uplink data packets from the second path, the PSA sends the uplink data packets from the second path.

[0009] In a possible implementation manner of the first aspect, the PSA receiving the end flag comprises: the PSA receives the end flag sent by an access network device.

[0010] The second aspect provides a method for transmitting data packets in a PDU session, which comprises the following steps: a SMF sends first indication information to a PSA, the first indication information being used to instruct the PSA to buffer uplink data packets received from a first path, and when an end flag from a second path is received, sending a message to the SMF, the message being used to indicate that the PSA has received the end flag, the end flag being used to indicate that the transmission of the uplink data packets on the second path is ended, the uplink data packets on the first path and the uplink data packets on the second path being uplink data packets of a same PDU session; the SMF receives the message sent by the PSA; the SMF sends second indication information to the PSA, the second indication information being used to instruct the PSA to send the buffered uplink data packets; wherein the transmission order of the uplink data packets on the first path is in sequence: a terminal device, an access network device, a new intermediate user plane function network element (I-UPF) and the PSA, or the terminal device, the access network device and the PSA; and the transmission order of the uplink data packets on the second path is in sequence: the terminal device, the access network device, a source I-UPF and the PSA, or the terminal device, the access network device and the PSA.

[0011] The second aspect provides a method for data packet transmission in a PDU session. The SMF can instruct the PSA to buffer the uplink data packets received on the new path before the PSA receives the indication information sent on the old path indicating that the uplink data packets have been sent. After the PSA receives the indication information sent on the old path indicating that the uplink data packets have been sent, the PSA sends the buffered uplink data packets received on the new path. In this way, the uplink data packets in a PDU session can be sent in a normal order, the server can save the time for sorting the uplink data packets, and the communication efficiency is ensured.

[0012] In a possible implementation of the second aspect, before the SMF sends the first indication information to the PSA, the method further includes: the SMF receiving first information from the AMF or the new I-SMF; and the SMF determining to send the first indication information to the PSA according to the first information, wherein the first information includes indication information indicating that the access network device does not change or third indication information indicating that the uplink data packets are sorted. In this implementation, the SMF can determine to instruct the PSA to buffer the uplink data packets received on the new path before the PSA receives the indication information sent on the old path indicating that the uplink data packets have been sent, so that the uplink data packets in a PDU session can be sent in a normal order, the server can save the time for sorting the uplink data packets, and the communication efficiency is ensured.

[0013] In a possible implementation of the second aspect, the method further includes: the SMF sending fourth indication information to the AMF or the access network device, the fourth indication information indicating that the access network device sends the end flag on the second path. In this implementation, the SMF can instruct the access network device to send the end flag on the second path, so that the PSA receives the end flag on the old path, the PSA can successfully send the buffered data packets, and the data packet transmission efficiency is ensured.

[0014] In a third aspect, a method for data packet transmission in a PDU session is provided. The method includes: an access network device receiving second information sent by an AMF network element; the access network device sending an end flag on a second path according to the second information, the end flag indicating that the transmission of the uplink data packets on the second path ends; and the access network device sending the uplink data packets on a first path. The transmission order of the uplink data packets on the first path is in sequence: a terminal device, the access network device, a new I-UPF, and the PSA, or a terminal device, the access network device, and the PSA. The transmission order of the uplink data packets on the second path is in sequence: a terminal device, the access network device, a source I-UPF, and the PSA, or a terminal device, the access network device, and the PSA.

[0015] The third aspect provides a method for data packet transmission in a PDU session. An access network device can send an end marker on a second path (old path), so that a PSA receives the end marker on the old path, and the PSA can successfully send the buffered data packets, and the efficiency of data packet transmission is ensured.

[0016] In a possible implementation manner of the third aspect, the second information includes at least one of tunnel information of the new I-UPF, tunnel information of the PSA, fourth indication information, or indication information that the access network device does not change.

[0017] In the fourth aspect, a method for data packet transmission in a PDU session is provided. The method includes: an access network device receiving fifth indication information from an AMF, the fifth indication information being used to indicate that the access network device buffers downlink data packets from a first path before receiving an end marker on a second path; the access network device buffering the downlink data packets from the first path before receiving the end marker on the second path according to the fifth indication information, the downlink data packets on the first path and the downlink data packets on the second path being downlink data packets of a same PDU session, the end marker being used to indicate that the transmission of the downlink data packets on the second path ends; the access network device sending the downlink data packets received on the second path to a terminal device; and the access network device sending the buffered downlink data packets to the terminal device when the end marker is received on the second path, wherein the transmission sequence of the downlink data packets on the first path is PSA, new I-UPF, the access network device, and the terminal device in sequence, or PSA, the access network device, and the terminal device in sequence, and the transmission sequence of the downlink data packets on the second path is PSA, source I-UPF, the access network device, and the terminal device in sequence, or PSA, the access network device, and the terminal device in sequence.

[0018] The fourth aspect provides a method for data packet transmission in a PDU session. The access network device sorts the received downlink data packets of a same PDU session on a new path (first path) and an old path (second path), buffers the received downlink data packets on the new path before the access network device receives indication information that the data packets sent on the old path have been sent, and sends the buffered downlink data packets 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, and the access network device sends the downlink data packets on the old path according to a normal process. Therefore, the downlink data packets in a PDU session can be sent in a normal sequence, the packet order of the PDU session is ensured, and the communication efficiency is ensured.

[0019] In a possible implementation of the fourth aspect, the fifth indication information comprises indication information that the access network device does not change.

[0020] In a possible implementation of the fourth aspect, the access network device receives the end marker on the second path comprises that the access network device receives the end marker from the PSA on the second path.

[0021] In a possible implementation of the fifth aspect, the PSA receives third information from the SMF, and sends an end marker on a second path according to the third information, the end marker being used to indicate that downlink packet transmission on the second path ends, wherein a transmission sequence of downlink packets on a first path is PSA, a new I-UPF, an access network device, and a terminal device in sequence, or PSA, the access network device, and the terminal device in sequence, a transmission sequence of downlink packets on the second path is PSA, a source I-UPF, the access network device, and the terminal device in sequence, or PSA, the access network device, and the terminal device in sequence, and the downlink packets on the first path and the downlink packets on the second path are downlink packets of a same PDU session.

[0022] In the method provided in the fifth aspect, the PSA can send the end marker on the second path (the old path), so that the access network device receives the end marker on the old path, and the access network device can successfully send the buffered downlink packets, and the efficiency of downlink packet transmission is ensured.

[0023] In a possible implementation of the fifth aspect, the third information comprises downlink tunnel information used to update the PSA or indication information used to indicate that the PSA sends the end marker on the second path.

[0024] In a sixth aspect, a method for packet transmission in a PDU session is provided, and the method comprises the following steps.

[0025] The SMF receives fourth information from the AMF or the new I-SMF, and sends third information to the PSA according to the fourth information, the third information being used to indicate that the PSA sends an end marker on a second path, the end marker being used to indicate that downlink packet transmission on the second path ends, wherein a transmission sequence of downlink packets on a first path is PSA, a new I-UPF, an access network device, and a terminal device in sequence, or PSA, the access network device, and the terminal device in sequence, a transmission sequence of downlink packets on the second path is PSA, a source I-UPF, the access network device, and the terminal device in sequence, or PSA, the access network device, and the terminal device in sequence, and the downlink packets on the first path and the downlink packets on the second path are downlink packets of a same PDU session.

[0026] In the sixth aspect, the SMF can determine, according to the information from the AMF or the new I-SMF, that the PSA sends the end marker on the second path (the old path), so as to ensure that the access network device receives the end marker on the old path, and ensure that the access network device can successfully send the buffered downlink data packet, and ensure the efficiency of downlink data packet transmission.

[0027] In a possible implementation manner of the sixth aspect, the fourth information includes indication information indicating that the access network device does not change, or indication information indicating that the downlink data packet is sorted.

[0028] In the seventh aspect, a method for data packet transmission in a PDU session is provided, which includes: a new I-UPF receiving sixth indication information from a first network element, the sixth indication information being used to indicate that the new I-UPF buffers uplink data packets received on a first path, and sends a message to the first network element when receiving an end marker from a second path, the message being used to indicate that the new I-UPF receives the end marker, the end marker being used to indicate that uplink data packet transmission on the second path ends, the uplink data packets on the first path and the uplink data packets on the second path being uplink data packets of the same PDU session; the new I-UPF sends the message to the first network element after receiving the end marker; the new I-UPF receives seventh indication information from the first network element, the seventh indication information being used to indicate that the new I-UPF sends the buffered uplink data packet; the new I-UPF sends the buffered uplink data packet on the first path according to the seventh indication information; wherein the transmission order of the uplink data packets on the first path is in turn: a terminal device, an access network device, the new I-UPF, and a PSA, and the transmission order of the uplink data packets on the second path is in turn: the terminal device, the access network device, a source I-UPF, the new I-UPF, and the PSA, or the terminal device, the access network device, the PSA, the new I-UPF, and the PSA.

[0029] In the seventh aspect, the method for data packet transmission in a PDU session can sort the received uplink data packets of the same PDU session on a new path (a first path) and an old path (a second path) by the I-UPF, the I-UPF buffers the received uplink data packets on the new path before receiving indication information indicating that the uplink data packets have been sent on the old path, and the I-UPF sends the buffered uplink data packets on the new path after receiving the indication information indicating that the uplink data packets have been sent on the old path, so as to ensure that the uplink data packets in a PDU session are sent in a normal order, thereby saving the sorting time of the server for the uplink data packets and ensuring the communication efficiency.

[0030] In a possible implementation of the seventh aspect, the method further includes: the new I-UPF sending the uplink data packet from the second path upon receiving the uplink data packet from the second path. In this implementation, the uplink data packet on the old path can be guaranteed to be sequentially transmitted.

[0031] In a possible implementation of the seventh aspect, the new I-UPF receiving the end marker includes: the new I-UPF receiving the end marker sent by the access network device.

[0032] In an eighth aspect, a method for transmitting data packets in a PDU session is provided. The method includes: a first network element sending sixth indication information to a new I-UPF, the sixth indication information being used to indicate that the new I-UPF buffers uplink data packets received on a first path, and sending a message to the first network element upon receiving an end marker from a second path, the message being used to indicate that the new I-UPF receives the end marker, the end marker being used to indicate that transmission of uplink data packets on the second path ends; the first network element receiving the message sent by the new I-UPF; and the first network element sending sixth indication information to the new I-UPF, the sixth indication information being used to indicate that the new I-UPF sends the buffered uplink data packets. The uplink data packets on the first path and the uplink data packets on the second path are uplink data packets of a same PDU session. The transmission order of the uplink data packets on the first path is in turn: a terminal device, an access network device, the new I-UPF, and a PSA. The transmission order of the uplink data packets on the second path is in turn: the terminal device, the access network device, a source I-UPF, the new I-UPF, and the PSA, or the terminal device, the access network device, the PSA, the new I-UPF, and the PSA.

[0033] The method for transmitting data packets in a PDU session provided in the eighth aspect can indicate the new I-UPF to buffer uplink data packets received on a new path (the first path) before the new I-UPF receives an end marker of the uplink data packets sent on an old path (the second path), and to send the buffered uplink data packets received on the new path after the new I-UPF receives the end marker of the uplink data packets sent on the old path. Thus, the uplink data packets in a PDU session can be transmitted in a normal order, the server can save time for sorting the uplink data packets, and communication efficiency can be guaranteed.

[0034] In a possible implementation 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 receiving fifth information from the AMF; and the first network element determining to send sixth indication information to the new I-UPF according to the fifth information, wherein the fifth information includes indication information that the access network device does not change or eighth indication information used to indicate that the uplink data packets are sorted. In this implementation, the first network element can determine, according to the information from the AMF, that the new I-UPF buffers the uplink data packets received on the first path, and sends a message to the first network element when the end marker from the second path is received, so as to ensure that the I-UPF sorts the uplink data packets received from the new path and the old path for the same PDU session. This ensures that the uplink data packets in a PDU session are sent in the normal order, thereby saving the sorting time of the server for the uplink data packets and ensuring the communication efficiency.

[0035] In a possible implementation 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 sending sixth information to the source I-SMF or the SMF, the sixth information including indication information that the access network device does not change or ninth indication information used to indicate that the source I-SMF or the SMF determines to establish a forwarding tunnel used to forward the uplink data packets; and the first network element receiving response information from the source I-SMF or the SMF in response to the sixth information, the response information including a forwarding indication used to establish a forwarding tunnel between the new I-UPF and the source I-UPF, or establish a forwarding tunnel between the new I-UPF and the PSA, or establish a forwarding tunnel between the source I-UPF and the PSA.

[0036] In a possible implementation of the eighth aspect, the method further includes: the first network element sending tenth indication information to the AMF or the access network device, the tenth indication information being used to indicate that the access network device sends the end marker on the second path.

[0037] In a possible implementation of the eighth aspect, the tenth indication information includes tunnel information of the new I-UPF.

[0038] In a possible implementation of the eighth aspect, the first network element is the SMF or the new I-SMF.

[0039] In a ninth aspect, a method for data packet transmission in a PDU session is provided. The method includes: receiving, by an access network device, seventh information sent by an AMF network element; sending, by the access network device, an end marker on a second path according to the seventh information, the end marker being used to indicate that uplink data packet transmission on the second path ends; and sending, by the access network device, uplink data packets on a first path, wherein the uplink data packets on the first path and the uplink data packets on the second path are uplink data packets of a same PDU session, and a transmission sequence of the uplink data packets on the first path is in an order of: a terminal device, the access network device, the new I-UPF, and a PSA, and a transmission sequence of the uplink data packets on the second path is in an order of: the terminal device, the access network device, a source I-UPF, the new I-UPF, and the PSA, or an order of: the terminal device, the access network device, the PSA, the new I-UPF, and the PSA.

[0040] In the method for data packet transmission in the PDU session provided in the ninth aspect, the access network device can send the end marker on the second path (old path), so that the new I-UPF receives the end marker on the old path, and the new I-UPF can successfully send the buffered data packets, and the efficiency of data packet transmission is ensured.

[0041] In a possible implementation manner of the ninth aspect, the seventh information includes: tunnel information of the new I-UPF or tenth indication information, the tenth indication information being used to indicate that the access network device sends the end marker on the second path.

[0042] In a tenth aspect, a method for data packet transmission in a PDU session is provided. The method includes: receiving, by a new I-UPF, eleventh indication information from a second network element, the eleventh indication information being used to indicate that the new I-UPF buffers downlink data packets received on a first path, and sends a message to the second network element when an end marker received from a second path is received, the message being used to indicate that the new I-UPF receives the end marker, the end marker being used to indicate that downlink data packet transmission on the second path ends, and the uplink data packets on the first path and the downlink data packets on the second path being uplink data packets of a same PDU session; sending, by the new I-UPF, the message to the second network element after the end marker is received; receiving, by the new I-UPF, twelfth indication information from the SMF, the twelfth indication information being used to indicate that the new I-UPF sends buffered downlink data packets; and sending, by the new I-UPF, the downlink data packets buffered on the first path according to the twelfth indication information, wherein a transmission sequence of the downlink data packets on the first path is in an order of: a PSA, the new I-UPF, an access network device, and a terminal device, and a transmission sequence of the downlink data packets on the second path is in an order of: the PSA, a source I-UPF, the new I-UPF, the access network device, and the terminal device, or an order of: the PSA, the access network device, the new I-UPF, the access network device, and the terminal device.

[0043] The tenth aspect provides a method for transmitting data packets in a PDU session. The method includes: sorting, by an I-UPF, received downlink data packets from a new path (a first path) and an old path (a second path) of a same PDU session; buffering, by the I-UPF, the received downlink data packets on the new path before the I-UPF receives indication information that the downlink data packets sent on the old path have been completely sent; and sending, by the I-UPF, the buffered downlink data packets on the new path after the I-UPF receives the indication information that the downlink data packets sent on the old path have been completely sent. Thus, the uplink data packets in the PDU session can be sent in a normal order, and communication efficiency is ensured.

[0044] In a possible implementation of the tenth aspect, the new I-UPF receives the end flag from the PSA.

[0045] In a possible implementation of the tenth aspect, the second network element is a new I-SMF or an SMF.

[0046] The eleventh aspect provides a method for transmitting data packets in a PDU session. The method includes: receiving, by a second network element, eighth information from an AMF, the eighth information including indication information that an access network device does not change or thirteenth indication information, the thirteenth indication information being used to indicate sorting of downlink data packets; and sending, by the second network element, eleventh indication information to a new I-UPF according to the eighth information, the eleventh indication information being used to instruct the new I-UPF to buffer received downlink data packets on a first path, and send a message to the second network element when an end flag from a second path is received, the message being used to indicate that the new I-UPF receives the end flag, the end flag being used to indicate that transmission of the downlink data packets on the second path ends. The uplink data packets on the first path and the downlink data packets on the second path are uplink data packets of a same PDU session, a transmission order of the downlink data packets on the first path is PSA, the new I-UPF, an access network device, and a terminal device in sequence, and a transmission order of the downlink data packets on the second path is PSA, a source I-UPF, the new I-UPF, the access network device, and the terminal device in sequence, or PSA, the access network device, the new I-UPF, the access network device, and the terminal device in sequence.

[0047] The method for transmitting data packets in a PDU session provided in the eleventh aspect can be used to instruct the I-UPF to sort the downlink data packets according to information from the AMF, so that the I-UPF can sort the downlink data packets from the new path (the first path) and the old path (the second path) of the same PDU session, and the uplink data packets in the PDU session can be transmitted in the normal order, thereby saving the sorting time of the server for the uplink data packets and ensuring the communication efficiency.

[0048] 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 sending ninth information to the source I-SMF or the SMF, the ninth information including indication information that the access network device does not change or fourteenth indication information, the fourteenth indication information being used to instruct the source I-SMF or the SMF to determine to establish a forwarding tunnel, the forwarding tunnel being used to forward the downlink data packets; and the second network element receiving response information from the source I-SMF or the SMF in response to the ninth information, the response information including a forwarding instruction, the forwarding instruction being 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.

[0049] In a possible implementation manner of the eleventh aspect, the method further includes: the second network element sending tenth information to the PSA, the tenth information being used to instruct the PSA to send the end marker on the second path.

[0050] In a possible implementation manner of the eleventh aspect, the tenth information includes downlink tunnel information or indication information used to update the PSA, the indication information being used to instruct the PSA to send the end marker on the second path.

[0051] In a possible implementation manner of the eleventh aspect, the second network element is a new I-SMF or an SMF.

[0052] In a twelfth aspect, a communication apparatus is provided, which includes units for performing each step in any one of the first aspect to the eleventh aspect, or any one of the possible implementation manners of the first aspect to the eleventh aspect.

[0053] In a thirteenth aspect, a communication apparatus is provided, which includes at least one processor and a memory, the processor and the memory being coupled, and the memory storing program instructions, when the program instructions stored in the memory are executed by the processor, performing each step in any one of the first aspect to the eleventh aspect, or any one of the possible implementation manners of the first aspect to the eleventh aspect.

[0054] In a fourteenth aspect, a communication apparatus is provided, which comprises at least one processor and interface circuitry, the at least one processor configured to perform the steps of any one of the first to eleventh aspects, or any possible implementation of the first to eleventh aspects.

[0055] In a fifteenth aspect, a computer program product is provided, which comprises a computer program configured to perform the steps of any one of the first to eleventh aspects, or any possible implementation of the first to eleventh aspects, when the computer program is executed by a processor.

[0056] In a sixteenth aspect, a computer-readable storage medium is provided, which stores a computer program configured to perform the steps of any one of the first to eleventh aspects, or any possible implementation of the first to eleventh aspects, when the computer program is executed by a processor.

[0057] In a seventeenth aspect, a chip is provided, which comprises a processor configured to invoke and run a computer program from a memory, so that a communication device installed with the chip performs the steps of any one of the first to eleventh aspects, or any possible implementation of the first to eleventh aspects. BRIEF DESCRIPTION OF DRAWINGS

[0058] Figure 1 is a schematic diagram of a communication system architecture provided by the present application.

[0059] Figure 2 is a schematic diagram of a MEC architecture provided by the present application.

[0060] Figure 3 is a schematic diagram of a 5G system architecture in an ETSUN scenario provided by the present application.

[0061] Figure 4 is a schematic flow chart of inserting an I-SMF according to a target DNAI provided by the present application.

[0062] Figure 5 is a schematic diagram of a data packet transmission path before and after time packet transmission route switching of a PDU session provided by the present application.

[0063] Figure 6 is a schematic diagram of a communication system architecture suitable for the present application.

[0064] Figure 7 is a schematic flow chart of a data packet transmission method in a PDU session provided by the present application.

[0065] Figure 8 is a schematic flow chart of part of the steps in a method of packet transmission in a PDU session provided by the present application.

[0066] Figure 9 is a schematic diagram of another example of a communication system architecture applicable to the present application.

[0067] Figure 10 is a schematic flow chart of a method of packet transmission in a PDU session provided by the present application.

[0068] Figure 11 is a schematic flow chart of part of the steps in a method of packet transmission in a PDU session provided by the present application.

[0069] Figure 12 is a schematic diagram of another example of a communication system architecture applicable to the present application.

[0070] Figure 13 is a schematic flow chart of a method of packet transmission in a PDU session provided by the present application.

[0071] Figure 14 is a schematic flow chart of part of the steps in a method of packet transmission in a PDU session provided by the present application.

[0072] Figure 15 is a schematic diagram of another example of a communication system architecture applicable to the present application.

[0073] Figure 16 is a schematic flow chart of a method of packet transmission in a PDU session provided by the present application.

[0074] Figure 17 is a schematic flow chart of part of the steps in a method of packet transmission in a PDU session provided by the present application.

[0075] Figure 18 is a schematic flow chart of part of the steps in a method of packet transmission in a PDU session provided by the present application.

[0076] Figure 19 is a schematic block diagram of a communication device according to an embodiment of the present application.

[0077] Figure 20 is a schematic block diagram of a communication device according to another embodiment of the present application.

[0078] Figure 21 is a schematic block diagram of a communication device according to an embodiment of the present application. DETAILED DESCRIPTION

[0079] The technical solutions in the present application will be described below with reference to the drawings.

[0080] In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" herein only describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0081] Hereinafter, the terms "first" and "second" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first" and "second" can explicitly or implicitly include one or more features. In the description of the embodiments, unless otherwise specified, the meaning of "multiple" is two or more than two.

[0082] In addition, various aspects or features of the present application can be implemented as a method, apparatus or product using standard programming and / or engineering techniques. The term "product" used in the present application covers computer programs that can be accessed from any computer readable device, carrier or medium. For example, the computer readable medium can include, but is not limited to: magnetic storage devices (such as hard disks, floppy disks or magnetic tapes, etc.), optical discs (such as compact discs (CD), digital versatile discs (DVD), etc.), smart cards and flash memory devices (such as erasable programmable read-only memory (EPROM), cards, sticks or key drive, etc.). In addition, the 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, but is not limited to, wireless channels and various other media capable of storing, containing and / or carrying instructions and / or data.

[0083] Various aspects or features of this application can be implemented as methods, apparatus, or articles of manufacture using standard programming and / or engineering techniques. As used herein, the term "article of manufacture" encompasses a computer program accessible from any computer-readable device, carrier, or medium. For example, computer-readable media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks, or magnetic tapes), optical discs (e.g., compact discs (CDs), digital versatile discs (DVDs), etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memory (EPROMs), cards, sticks, or key drives, etc.). Additionally, the various storage media described herein may represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing, and / or carrying instructions and / or data.

[0084] The 5G network architecture defined by the 3rd Generation Partnership Project (3GPP) is as follows: (The text abruptly ends here, likely due to an incomplete translation or source material.) Figure 1 The main components shown include: terminal equipment, wireless access network equipment, management equipment, gateway equipment, and data network (DN). Among them, Figure 1 The terminal devices in this system can be used to connect to the access network equipment deployed by the operator via a wireless air interface, and then connect to the data network through a gateway device. The access network equipment is mainly used to implement wireless physical layer functions, resource scheduling and wireless resource management, wireless access control, and mobility management. The management equipment is mainly used for terminal device registration, security authentication, mobility management, and location management. The gateway device is mainly used to establish a channel with the terminal device, forwarding data packets between the terminal device and the external data network on this channel. The data network can correspond to various different service domains, such as IP multimedia subsystem (IMS), the Internet, Internet protocol television (IPTV), and other operator service domains. It is mainly used to provide various data service providers for the terminal devices, and may include network devices such as servers (including servers providing multicast services), routers, and gateways. It should be noted that... Figure 1 This is merely an illustrative architecture diagram, except... Figure 1In addition to the functional units shown in the network architecture, the network architecture can also include other functional units or functional network elements, which are not limited by embodiments of the present application.

[0085] In Figure 1 In the architecture shown, the terminal device can be a user equipment (UE), such as a mobile phone, computer, and can also be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a smart phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a computer, a laptop, a handheld communication device, a handheld computing device, a satellite radio telephone, a wireless modem card, a television set top box (STB), a customer premise equipment (CPE), and / or other devices that communicate over a wireless system.

[0086] The access network device can be an access network (AN) / radio access network (RAN) device, a network composed of multiple 5G-AN / 5G-RAN nodes. For example, the 5G-AN / 5G-RAN node can be an access point (AP), a base station (BS), a next generation base station (NR nodeB, gNB), a gNB in a central unit (CU) and distributed unit (DU) separation form, a transmission receive point (TRP), a transmission point (TP), or some other access node. It can also be a base station (NodeB, NB) in a wideband code division multiple access (WCDMA) system, an evolved base station (eNB or eNodeB) in an LTE system, a wireless controller in a cloud radio access network (CRAN) scenario, or the access network device can be a relay station, a wireless fidelity access point (WiFi AP) in wireless fidelity technology, a worldwide interoperability for microwave access (WiMAX), and a network device in a 5G network or an access network device in a future evolved public land mobile network (PLMN), and the like. The embodiments of the present application are not limited.

[0087] The management device can include a unified data management network element (UDM), an access and mobility management function (AMF), a session management function (SMF), a policy control function (PCF), an application function (AF), and the like.

[0088] The gateway device described above can include a user plane function (UPF). In some embodiments, the gateway device can also include a Branching Point (BP), an Uplink Classifier (UL CL), and the like functional units. These functional units can work independently or be combined to implement certain control functions. For example, the AMF is mainly responsible for mobility management in the mobile network, such as user location update, user registration network, user handover, and the like. The SMF is mainly responsible for session management in the mobile network, such as session establishment, modification, and release, and specific functions such as allocating IP addresses for users, selecting UPFs that provide message forwarding functions, and the like. The PCF is responsible for providing policies to the AMF and the SMF, such as quality of service (QoS) policies, slice selection policies, and the like. 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 service routing, interacting with the PCF for policy control, and the like. The UPF is mainly responsible for processing user messages, such as forwarding, charging, and the like.

[0089] For another example, the AMF, the SMF, and the PCF can be combined together as a management device, which is used to complete access authentication, security encryption, location registration, and the like access control and mobility management functions of the terminal device, as well as session management functions such as establishment, release, and change of user plane transmission paths, and functions of analyzing some slice-related data (such as congestion) and terminal device-related data. The UPF as a gateway device mainly completes the functions of routing and forwarding of user plane data, such as being responsible for filtering data messages of the terminal device, data transmission / forwarding, rate control, generating charging information, and the like.

[0090] In some embodiments, in order to support the selective routing of traffic to a data network in a 5G system, a session management network element can control the data path of a protocol data unit (PDU) session, so that multiple interfaces can correspond to a PDU session and a data network at the same time, i.e., multiple session anchors can exist for the same PDU session. The user plane function (UPF) that terminates these interfaces is referred to as a PDU session anchor (PSA) or anchor UPF. Each anchor of a PDU session can also provide a different entry to the same DN. At the same time, data splitting to different PSAs is achieved by inserting one or more UPF network elements between the access network device and the different PSAs, which can be branching points (BPs) or uplink classifiers (UL CLs). Hereinafter, it is uniformly stated that the BP or UL CL can also be referred to as a splitting point UPF network element.

[0091] In Figure 1 In the illustrated 5G network, the functional units can communicate with each other through next generation (NG) interfaces, such as: a terminal device establishes an air interface connection with a RAN device through a new radio (NR) interface, which is used to transmit user plane data and control plane signaling; the terminal device can establish a control plane signaling connection with an AMF through an NG interface 1 (N1 for short); an access network device (for example, an AN / RAN device) can establish a user plane data connection with a UPF through an NG interface 3 (N3 for short); the access network device can establish a control plane signaling connection with the AMF through an NG interface 2 (N2 for short); the UPF can establish a control plane signaling connection with an SMF through an NG interface 4 (N4 for short); the UPF can interact with a data network through an NG interface 6 (N6 for short) to transmit user plane data; the AMF can establish a control plane signaling connection with the SMF through an NG interface 11 (N11 for short); the SMF can establish a control plane signaling connection with a PCF through an NG interface 7 (N7 for short); a UDM can establish a control plane signaling connection with the PCF through an NG interface 25 (N25 for short);

[0092] It should be understood that the interface names between the network elements in the embodiments of the present application are only exemplary, and the interfaces between the network elements can also be other names, and the present application does not limit the name of the interface.

[0093] In order to effectively meet the requirements of high bandwidth and low latency required by the rapid development of mobile Internet and Internet of Things, and reduce network load, the European Telecommunication Standard Institute (ETSI) proposed a mobile edge computing (MEC) technology in 2014. MEC is an evolved architecture based on 5G networks, which is a technology that deeply integrates access networks and Internet services. It deploys application servers (AS) and mobile broadband (MBB) core network service processing and resource scheduling functions to the network edge close to the access network, and provides reliable and ultra-low latency extreme service experience through service close to user processing.

[0094] Figure 2 As shown in the schematic diagram of the MEC architecture provided in the present application, as shown in the schematic diagram of the MEC architecture provided in the present application, Figure 2 As shown, compared with the DN network, the MEC is deployed at the sunken UPF (i.e. local UPF); the DN network is deployed at the remote UPF. Compared with the path of the UE accessing the DN (as shown by the dashed line), the path of the UE accessing the MEC platform (as shown by the solid line) is greatly shortened. Therefore, the MEC technology can provide low latency and high bandwidth services for users.

[0095] The identity of the MEC platform is used to uniquely identify an MEC platform. In some embodiments, the identity of the MEC platform can be a data network access identity (DNAI) supported by the UPF network element deployed on the MEC platform or a DNAI supported by the UPF network element connected to the MEC platform, so that different DNAIs can represent different MEC platforms. In other words, the DNAI can be used to represent the identity of the user plane path of the terminal device accessing the data network. For example, the path of accessing MEC1 can be represented by DNAI-1, and the path of accessing EMC2 can be represented by DNAI-2. The DNAI can be understood as the location of the MEC platform.

[0096] In the 3GPP R16 stage, the scenario of enhancing topology of SMF and UPF in 5G networks (ETSUN) is proposed. In this scenario, the SMF cannot serve the entire PLMN, and the service area of the SMF (SMF service area, SMF SA) refers to the sum of the service areas of all UPFs controlled by the SMF.

[0097] In the ETSUN scenario, when the UE moves out of the SMF SA, an intermediate SMF (I-SMF) is inserted; when the UE moves out of the I-SMF SA and is not in the SMF SA, I-SMF change occurs; when the UE moves into the SMF SA, the I-SMF is removed, that is, I-SMF update occurs.

[0098] For example, in 5G, due to different service areas managed by different SMFs, the same PDU session can correspond to two SMF network elements. For example, when a terminal device establishes a PDU session at location-1, the PDU session has a corresponding anchor user plane function network element (for example, UPF1), which is managed by an anchor SMF. When the terminal moves from location-1 to location-2 and switching occurs, the user plane function network element corresponding to the access network device after switching is outside the service area of the original anchor SMF, and is managed by a new anchor intermediate SMF (I-SMF). At this time, a scenario in which a session corresponds to two SMFs occurs.

[0099] Figure 3 The figure shows a schematic diagram of a 5G system architecture in an ETSUN scenario. Figure 3 In the architecture shown, there are I-SMF and SMF, wherein the UPF controlled by the I-SMF is UPF1, and the UPF controlled by the SMF is UPF2.

[0100] When the network side has a demand, for example, the AF provides the service corresponding DNAI to the PCF, thereby triggering the SMF to establish the user plane path corresponding to the DNAI. When the MEC platform corresponding to the DNAI is not within the service range of the SMF, in combination with the above-mentioned MEC technology and ETSUN, it can be known that, in this case, the I-SMF is inserted in the control plane by the AMF according to the DNAI, and the I-UPF is inserted in the user plane by the I-SMF, thereby realizing the establishment of the user plane path corresponding to the DNAI to access the corresponding MEC platform, wherein the I-UPF is controlled by the I-SMF.

[0101] For I-SMF update, there are mainly three different scenarios:

[0102] First, I-SMF insertion, that is, there is an original source SMF, and when the terminal device moves out of the service range of the source SMF, a new I-SMF is inserted, and after the insertion of the new I-SMF, the network architecture has the new I-SMF and the SMF.

[0103] The second type is change of the I-SMF, that is, there is a source I-SMF, which can also be referred to as an old I-SMF. When the terminal device moves out of the service range of the old I-SMF, the I-SMF serving the terminal device changes to a new I-SMF, and the network architecture includes the new I-SMF and the SMF.

[0104] The third type is removal of the I-SMF, that is, there is a source I-SMF and an SMF, which can also be referred to as an old I-SMF. When the terminal device moves out of the service range of the old I-SMF, the I-SMF serving the terminal device changes to the SMF, and the source I-SMF is removed, and the network architecture includes only the SMF.

[0105] Figure 4 An example of a schematic flowchart of inserting an I-SMF according to a target DNAI is shown in FIG. 4. Figure 4 The flowchart includes the following steps.

[0106] S401. The PCF sends a policy and charging control (PCC) rule to the SMF.

[0107] Optionally, the PCC rule carries (or includes) the DNAI.

[0108] For example, in some embodiments, the PCF can send a policy control update notification (Npcf_SM PolicyControl_UpdateNotify) to the SMF through an Npcf interface, and the notification carries the PCC rule.

[0109] S402. The SMF sends target DNAI information (target DNAI info) to the AMF. The target DNAI info includes a target DNAI (target DNAI), and the target DNAI info is used to instruct the AMF to insert an I-SMF.

[0110] In some embodiments, the SMF first determines the target DNAI (target DNAI), and after determining the target DNAI, the SMF judges that it cannot serve the target DNAI, and then sends the target DNAI to the AMF.

[0111] In some embodiments, the SMF can determine the target DNAI according to the location of the terminal device, the DNAI in step S401, and the like.

[0112] Optionally, when the PCC rule in step S401 does not contain the DNAI, the target DNAI information sent by the SMF to the AMF in S402 does not contain the target DNAI.

[0113] For example, in some embodiments, the SMF can send a PDU session context status notification (Nsmf_PDUSession_SMContextStatusNotify) to the AMF, and the notification carries the target DNAI info.

[0114] S403: The AMF selects and inserts an I-SMF (i.e., a new I-SMF) according to the target DNAI.

[0115] In some embodiments, S403 can also be replaced by: when the AMF determines that the SMF can serve the target DNAI according to the target DNAI, or when the AMF does not receive the target DNAI, the AMF deletes the I-SMF.

[0116] S404: The AMF sends a create context request to the I-SMF (new I-SMF), and the request carries: a session identifier, a session management (SM) context identifier (SM context ID), terminal device location information (UE location info), a target DNAI, and indication information of no NG-RAN change, and the like. Wherein, NG-RAN represents a next generation (NG) wireless access network device.

[0117] In some embodiments, when the AMF determines to delete the I-SMF, S404 can also be replaced by: the AMF sends a create or update context request to the SMF.

[0118] For example, in some embodiments, the AMF can send a create PDU session context request (Nsmf_PDU Session_CreateSMContext) to the I-SMF or the SMF, and the request carries the information in S404.

[0119] Wherein, the session identifier is used to indicate the current PDU session.

[0120] The SM context ID is used to indicate the identity of the source I-SMF. In the I-SMF insertion scenario (i.e., the control plane corresponding to this session is originally: AMF, SMF; after the I-SMF is inserted, it becomes: AMF, new I-SMF, SMF), the SM context ID is used to point to the SMF; in the I-SMF change scenario (i.e., the control plane corresponding to this session is originally: AMF, old I-SMF, SMF; after the I-SMF is inserted, it becomes: AMF, new I-SMF, SMF), the SM context ID is used to point to the old I-SMF.

[0121] The Target DNAI is used to represent the MEC platform location, or in other words, the Target DNAI is used to represent the identity of the user plane connection corresponding to the access MEC platform.

[0122] The indication of no NG-RAN change is used to indicate that the NG-RAN tunnel information (NG-RAN tunnel info) does not change. When the terminal device is in the connected state, the AMF sends this parameter to the new I-SMF.

[0123] S405: The new I-SMF obtains the SM context from the old I-SMF (corresponding to the I-SMF change scenario) or the SMF (corresponding to the I-SMF insertion scenario).

[0124] For example, in some embodiments, the new I-SMF can send a context request to the old I-SMF (corresponding to the I-SMF change or removal scenario) or the SMF, carrying the indication of no NG-RAN change, etc. Then, the old I-SMF or the SMF returns a context response to the new I-SMF, carrying the NG-RAN tunnel information (NG-RAN tunnel info).

[0125] S406: The new I-SMF selects a new I-UPF according to the target DNAI.

[0126] S407: The new I-SMF sends the NG-RAN tunnel information (NG-RAN tunnel info) to the new I-UPF. In this way, the downlink path between the new I-UPF and the NG-RAN is established.

[0127] S408:new I-SMF establishes a user plane path between new I-UPF and PSA.

[0128] S409:new I-SMF inserts a routing point based on the target DNAI, such as inserting a UL CL or BP, to route the service flow to the MEC platform corresponding to the target DNAI.

[0129] Figure 5 The following is shown Figure 4 The diagram illustrates the data packet transmission paths before and after the switch, corresponding to the process shown. Among them, Figure 4 The process shown can be summarized into four steps, namely steps 1 to 4 below:

[0130] In step 1, the SMF sends a new requested DNAI to the AMF, and the AMF selects a new I-SMF based on the DNAI.

[0131] In step 2, the AMF sends the SM context ID and an indication of no NG-RAN change to the new I-SMF. Specifically, in I-SMF change or I-SMF remove scenarios, the SM context ID points to the source I-SMF; in I-SMF insert scenarios, the SM context ID points to the SMF.

[0132] In step 3, the new I-SMF obtains the NG-RAN downlink tunnel information (SM context includes additional Downlink Tunnel Info of NG-RAN).

[0133] In step 4, the new I-SMF selects the new I-UPF, and the new I-UPF sends its tunnel information to the NG-RAN to establish a transmission path between the new I-UPF and the NG-RAN.

[0134] Among them, Figure 5In the scenario shown, before step 4, the context information of the terminal device at the NG-RAN side (UE context in NG-RAN) includes the tunnel information (Tunnel Info) of the source I-UPF. After step 4, the context information of the terminal device at the NG-RAN side includes the tunnel information (Tunnel Info) of the target I-UPF.

[0135] In Figure 5 In the scenario shown, before step 4, the context information of the terminal device at the NG-RAN side (UE context in NG-RAN) includes the tunnel information (Tunnel Info) of the source I-UPF. After step 4, the context information of the terminal device at the NG-RAN side includes the tunnel information (Tunnel Info) of the target I-UPF.

[0136] As can be seen from Figure 5 In the scenario shown, before step 4, the context information of the terminal device at the NG-RAN side (UE context in NG-RAN) includes the tunnel information (Tunnel Info) of the source I-UPF. After step 4, the context information of the terminal device at the NG-RAN side includes the tunnel information (Tunnel Info) of the target I-UPF. Figure 5 In the scenario shown, the dashed line represents the old path, and the solid line represents the new path.

[0137] For uplink packets (also referred to as uplink data packets), the user plane paths before and after the I-UPF change are respectively:

[0138] The path before the change (referred to as the old path): UE→NG-RAN→old I-UPF→PSA.

[0139] The path after the change (referred to as the new path): UE→NG-RAN→new I-UPF→PSA.

[0140] For uplink packets, the user plane paths before and after the I-UPF insertion are respectively:

[0141] The path before the insertion (referred to as the old path): UE→NG-RAN→PSA.

[0142] The path after the insertion (referred to as the new path): UE→NG-RAN→new I-UPF→PSA.

[0143] For uplink packets, the user plane paths before and after the I-UPF removal are respectively:

[0144] Path before removal (referred to as old path): UE→NG-RAN→old I-UPF→PSA.

[0145] Path after removal (referred to as new path): UE→NG-RAN→PSA.

[0146] It can be seen that for uplink packets of the same PDU session, the PSA receives packets from two paths (old path and new path) in the above three cases. When the packets on the new path arrive at the PAS earlier than the old path, out-of-order occurs, causing communication problems. For example: assuming that a PDU session includes 10 packets, the first to sixth packets are transmitted on the old path, and the seventh to tenth packets are transmitted on the new path, if the PSA receives the seventh to tenth packets first, the PSA will continue to send the seventh to tenth packets to the server (for example, an application server located in a DN), and then send the first to sixth packets received later to the server. In normal cases, the order of the packets arriving at the server should be: the first to tenth packets. However, in the above scenario, the order of the packets arriving at the server may be: the seventh to tenth packets, the first to sixth packets, that is, the packets received by the server will be out of order, increasing the time consumption of the server for sorting the packets, increasing the communication delay, and unable to guarantee the communication efficiency.

[0147] For downlink packets (also referred to as downlink data packets), the user plane paths before and after the I-UPF change are respectively:

[0148] Path before change (referred to as old path): PSA→old I-UPF→NG-RAN→UE.

[0149] Path after change (referred to as new path): PSA→new I-UPF→NG-RAN→UE.

[0150] For downlink packets, the user plane paths before and after the I-UPF insertion are respectively:

[0151] Path before insertion (referred to as old path): PSA→NG-RAN→UE.

[0152] Path after insertion (referred to as new path): PSA→new I-UPF→NG-RAN→UE.

[0153] For downlink packets, the user plane paths before and after the I-UPF removal are respectively:

[0154] Path before removal (referred to as old path): PSA→old I-UPF→NG-RAN→UE.

[0155] Path after removal (referred to as new path): PSA→NG-RAN→UE.

[0156] It can be seen that, for downlink packets of the same PDU session, the NG-RAN receives packets from two paths (old path and new path) in the above three cases. For example, assuming that a PDU session includes 8 packets, the first to fourth packets are transmitted on the old path, and the fifth to eighth packets are transmitted on the new path, if the NG-RAN receives the fifth to eighth packets first, the NG-RAN continues to send the fifth to eighth packets to the terminal device, and then sends the first to fourth packets received later to the terminal device. In a normal case, the order of the packets sent by the NG-RAN to the terminal device is: the first to eighth packets, but in the above scenario, the order of the packets sent by the NG-RAN to the terminal device is: the fifth to eighth packets, the first to fourth packets, which causes the packets received by the terminal device to be out of order, thereby increasing the time consumption of the terminal device for sorting the packets, increasing the communication delay, and failing to guarantee the communication efficiency.

[0157] In view of this, the present application provides a method and a communication device for PDU session data packet transmission. In the scenario of I-SMF update (change / insertion / removal) or I-UPF update (change / insertion / removal) in a PDU session, the PSA receives uplink data (or also referred to as uplink packets) of the same PDU session from different paths, which causes the problem of packet disorder, or the access network device receives downlink data (or also referred to as downlink packets) of the same PDU session from different paths, which causes the problem of packet disorder. By using a gateway (PSA, access network device, or I-UPF) to sort the data packets of a PDU session from different paths, the uplink data packets or the downlink data packets are transmitted in the normal order, avoiding the process of sorting the data packets by the terminal device or the server, reducing the communication delay, and thereby guaranteeing the communication efficiency.

[0158] The method provided by the present application will be described below in conjunction with specific examples.

[0159] In the following embodiments, the access network device will be described by taking the NG-RAN as an example, but this should not limit the access network device in the embodiments of the present application in any way.

[0160] It should also be understood that the method provided by the embodiments of the present application can be applied to the scenario of I-SMF update (change / insertion / removal), and can also be applied to the scenario of only I-UPF update (change / insertion / removal). The present application does not make any limitation here, and the following will be described by taking the scenario of I-SMF update (change / insertion / removal) as an example.

[0161] In each of the following embodiments, the old path can also be referred to as a second path, and the new path can also be referred to as a first path.

[0162] Figure 6 The communication system scenario provided by the embodiments of the present application is shown schematically, Figure 7 The communication system scenario provided by the embodiments of the present application is shown schematically, Figure 6 The method for packet transmission in the PDU session in the scenario shown is shown schematically in a flowchart. In some embodiments, in the Figure 7 In the method shown, the PSA sorts the uplink packets from the same PDU session on different paths.

[0163] In the scenario shown, Figure 6 In the scenario shown, the solid line represents the transmission of uplink packets on the new path, and the dashed line represents the transmission of uplink packets on the old path. The uplink packets on the new path and the uplink packets on the old path are uplink packets included in the same PDU session.

[0164] The transmission path of the uplink packets on the old path is: terminal device→NG-RAN→source I-UPF→PSA, and the transmission path of the uplink packets on the new path is: terminal device→NG-RAN→target I-UPF→PSA.

[0165] In the scenario shown, Figure 6 In the scenario shown, when the NG-RAN does not change:

[0166] Before the I-SMF or I-UPF change, the source I-UPF is the old I-UPF, and after the I-SMF or I-UPF change, the target I-UPF is the new I-UPF.

[0167] Before the I-SMF or I-UPF insertion, the source I-UPF is the PSA, i.e., the old path becomes: terminal device→NG-RAN→PSA. After the I-SMF or I-UPF insertion, the target I-UPF is the new I-UPF.

[0168] Before the removal of I-SMF or I-UPF, the source I-UPF is the old I-UPF. After the removal of I-SMF or I-UPF, the target I-UPF becomes PSA. That is, the new path becomes: terminal device → NG-RAN → PSA.

[0169] It is understandable that when NG-RAN changes, for example, when NG-RAN changes from the old NG-RAN (or what could be called the source NG-RAN) to the new NG-RAN, in Figure 6 In the scenario shown, the old path is the path before the NG-RAN change, i.e., the old path is: Terminal Device → Old NG-RAN → New NG-RAN → PSA. The path after the NG-RAN change, i.e., the new path, is: Terminal Device → New NG-RAN → PSA. During the NG-RAN change process, i.e., during the NG-RAN handover, when the new NG-RAN receives new uplink tunnel information, it sends an end marker on the old path, for example, the uplink tunnel information is "PSA tunnel info". It is understood that this example does not involve I-UPF. When I-UPF is involved, the new uplink tunnel information refers to I-UPF tunnel info. Specifically, the Xn tunnel between the new NG-RAN and the old NG-RAN is established by the old NG-RAN. For example, if 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, then the uplink tunnel (Xn tunnel) between the new NG-RAN and the old NG-RAN is established.

[0170] like Figure 7 As shown, the method includes:

[0171] S701: PCF sends PCC rules to SMF.

[0172] Optionally, the PCC rule carries (or contains) DNAI.

[0173] For example, in some embodiments, the PCF can send a policy control update notification (Npcf_SM PolicyControl_UpdateNotify) to the SMF through the Npcf interface, which carries the PCC rules.

[0174] S702: The SMF sends target DNAI information (target DNAI info) to the AMF. The target DNAI info contains the target DNAI and is used to instruct the AMF to insert the I-SMF.

[0175] In some embodiments, the SMF first determines a target DNAI, and after determining the target DNAI, the SMF judges that the target DNAI cannot be served, and the SMF sends the target DNAI to the AMF. For example, the SMF can determine the target DNAI according to the location of the terminal device, the DNAI in step S701, and the like.

[0176] In some embodiments, if the PCC rule in S701 does not contain the DNAI, then in S702, the target DNAI info sent by the SMF to the AMF does not contain the target DNAI.

[0177] For example, in some embodiments, the SMF can send a PDU session context status notification (Nsmf_PDUSession_SMContextStatusNotify) to the AMF, and the notification carries the target DNAI info.

[0178] S703: The AMF selects and inserts a new I-SMF (new I-SMF) according to the target DNAI.

[0179] In some embodiments, S703 can also be replaced by: when the AMF judges that the SMF can serve the target DNAI according to the target DNAI, or when the AMF does not receive the target DNAI and does not need the I-SMF, the AMF deletes the I-SMF.

[0180] For the scenario of I-SMF / I-UPF insertion and I-SMF / I-UPF change, after S703, S704a to S710a are performed: as shown in Figure 8 .

[0181] S704a: The AMF sends a create context request to the new I-SMF, and the request carries: a session identifier, a session management context identifier (SM context ID), terminal device location information (UE location info), a target DNAI, an indication of no NG-RAN change, and the like.

[0182] Among them, the session identifier is used to indicate the current PDU session.

[0183] The SM context ID is used to indicate the identity of the source I-SMF. Among them, in the I-SMF insertion scenario (i.e., the control plane corresponding to this session is originally: AMF, SMF; after the insertion of the I-SMF, it becomes: AMF, new I-SMF, SMF), the SM context ID is used to point to the SMF; in the I-SMF change scenario (i.e., the control plane corresponding to this session is originally: AMF, old I-SMF, SMF; after the insertion of the I-SMF, it becomes: AMF, new I-SMF, SMF), the SM context ID is used to point to the old I-SMF.

[0184] Target DNAI is used to represent the MEC platform location.

[0185] The indication of no NG-RAN change is used to indicate that the NG-RAN tunnel information (NG-RAN tunnel info) does not change.

[0186] S705a: The new I-SMF obtains the session management context (SM context) from the old I-SMF or the SMF.

[0187] In some embodiments, for the I-SMF change scenario: the new I-SMF can send a context request to the old I-SMF (or can be referred to as the source I-SMF), carrying the indication of no NG-RAN change. After the old I-SMF receives the context request, it returns a context response to the new I-SMF, which carries the NG-RAN tunnel information (NG-RAN tunnel info) in the response.

[0188] In some embodiments, for the I-SMF insert scenario: the new I-SMF can send a context request to the SMF, which carries the indication of no NG-RAN change. After the SMF receives the request, it returns a context response to the new I-SMF, which carries the NG-RAN tunnel info in the response.

[0189] S706a: The new I-SMF selects a new I-UPF (new I-UPF), and obtains the tunnel information of the new I-UPF (new I-UPF tunnel info).

[0190] S707a: The new I-SMF sends a PDU session update request or a PDU session creation request to the SMF, carrying the first indication information.

[0191] In some embodiments, for the I-SMF change scenario, the new I-SMF can send a PDU session update request (Nsmf_PDU Session_Update Request) to the SMF.

[0192] In some embodiments, for the I-SMF insert scenario, the new I-SMF can send a PDU session creation request (Nsmf_PDU Session_Create Request) to the SMF.

[0193] The PDU session update request or the PDU session creation request carries the first indication information, and optionally, one or more of the following: the SM context ID, the new I-UPF tunnel info, and the DNAI list supported by the new I-SMF.

[0194] Optionally, as one possible implementation, the first indication information is used to indicate that the SMF instructs the PSA to buffer the uplink data packets from the new I-UPF (new path), and when the PSA receives an end marker of the uplink data packets from the old I-UPF (old path), the PSA reports a message to the SMF, which is used to indicate that the PSA has received the end marker of the old path. The end marker is used to indicate that the uplink data packets sent in the old path have been sent completely.

[0195] Alternatively, as another possible implementation, the first indication information can be used to indicate that the uplink data packets need to be sorted.

[0196] Alternatively, as another possible implementation, the first indication information can be used to indicate that the access network device is unchanged.

[0197] In some embodiments, the first indication information can be indication of no NG-RAN change, which is used to indicate that the access network device is unchanged.

[0198] In some embodiments, the first indication information can be indication of no NG-RAN change, that is, the indication of no NG-RAN change can be used to indicate that the access network device is unchanged, or can be used to indicate that the uplink data packets need to be sorted.

[0199] In some embodiments, the first indication information and the indication of no NG-RAN change can be different information respectively.

[0200] In some embodiments, when the first indication information is used to indicate that the access network device is unchanged, the SMF can determine that the uplink data packets need to be sorted according to the indication of no NG-RAN change.

[0201] In some embodiments, the information that the uplink data packets on the old path have been sent can be an end marker of the uplink data packets sent by the old path.

[0202] S708a: The SMF sends second indication information to the PSA, and the second indication information is generated according to the first indication information.

[0203] In some embodiments, the SMF can determine to send the second indication information to the PSA according to the first indication information in S707a.

[0204] In some embodiments, the second indication information is used to indicate that the PSA caches the uplink packets from the new I-UPF (new path), and when the PSA receives an end marker of the uplink data packets from the old I-UPF or the NG-RAN (old path), the PSA sends a report message to the SMF, and the report message is used to indicate that the PSA receives the end marker of the uplink data packets on the old path.

[0205] For example, the SMF can generate the second indication information according to the first indication information, and the second indication information indicates that the PSA caches the uplink data packets from the new path, and when the PSA receives an end marker of the uplink data packets from the old path, the PSA reports a message to the SMF, and the message is used to indicate that the PSA receives the end marker of the uplink data packets on the old path.

[0206] For the I-SMF insert scenario, the second indication information indicates that the PSA caches the uplink data packets from the new I-UPF (new path), and when the PSA receives an end marker of the uplink data packets from the NG-RAN (old path), the PSA sends a report message to the SMF, and the report message is used to indicate that the PSA receives the end marker of the uplink data packets on the old path.

[0207] For the I-SMF change scenario, the second indication information indicates that the PSA caches the uplink data packets from the new I-UPF (new path), and when the PSA receives an end marker of the uplink data packets from the old I-UPF (old path), the PSA reports a message to the SMF, which indicates that the PSA has received the end marker of the uplink data packets on the old path.

[0208] In some embodiments, the second information indication can be an N4 rule.

[0209] S709a: The SMF returns a PDU session update response or a PDU session creation response to the new I-SMF.

[0210] In some embodiments, the PDU session update response or the PDU session creation response includes new I-UPF tunnel information, etc.

[0211] S710a: The new I-SMF sends a create context response information to the AMF, which carries PSA tunnel information.

[0212] Optionally, the response information further includes third indication information. The third indication information is used to indicate that the NG-RAN sends an end marker on the old path.

[0213] In some embodiments, the third indication information can be an indication of no NG-RAN change, and in other embodiments, the third indication information and the indication of no NG-RAN change can be different information.

[0214] In some embodiments, the response (information) includes N2 SM info, and the N2 SM info includes the new I-UPF tunnel information and the third indication information described above.

[0215] After step S710a, steps S711 to S715 are performed, as shown in Figure 7 .

[0216] For the I-SMF / I-UPF removal scenario, after S703, steps S704b to S708b are performed, as shown in Figure 8 .

[0217] S704b: The AMF sends an Update Context Request to the SMF. This request carries: session identifier, session management context identifier (SM context ID), UE location info, target DNAI, and indication of no NG-RAN change.

[0218] Optionally, the update context request may also include indication information that indicates that uplink packets need to be sorted.

[0219] In some embodiments, the indication information can be an indication of no NG-RAN change. That is, an indication of no NG-RAN change can be used to indicate that the access network device has not changed, or it can be used to indicate that uplink data packets need to be sorted.

[0220] In other embodiments, the indication and the indication of no NG-RAN change may be different messages.

[0221] In some embodiments, when the request does not carry the indication information and the indication of no NG-RAN change is not used to indicate that uplink packets need to be sorted, the SMF can determine that uplink packets need to be sorted based on the indication of no NG-RAN change.

[0222] S705b:SMF obtains the SM context from the old I-SMF.

[0223] S706b: Select new I-UPF for SMF and obtain I-UPF tunnel info.

[0224] It should be understood that S706b is an optional step. When the process does not include S706b, the new path becomes: terminal device → NG-RAN → PSA. In this embodiment, the example is that the SMF does not have an I-UPF inserted.

[0225] S707b: The SMF sends a message to the PSA. The message carries fourth indication information, which indicates that the PSA buffers uplink data packets from the NG-RAN (new path), and indicates that when the PSA receives an end marker sent from the old I-UPF (old path), the PSA reports a message to the SMF, which indicates that the PSA has received the end marker of the uplink data packets on the old path. In some embodiments, the message can be the end marker of the uplink data packets on the old path. Wherein, the end marker of the uplink data packets on the old path indicates that the uplink data packets on the old path have been sent completely.

[0226] In some embodiments, the SMF can determine to send the fourth indication information to the PSA according to the indication information from the AMF in S704b.

[0227] In some embodiments, the SMF can send an N4 rule to the PSA, and the N4 rule contains the fourth indication information.

[0228] S708b: The SMF sends an update context response information to the AMF, and the response information carries: new I-UPF tunnel info.

[0229] Optionally, the response information further includes fifth indication information. Wherein, the fifth indication information indicates that the NG-RAN sends an end marker on the old path.

[0230] In some embodiments, the fifth indication information can be indication of no NG-RAN change, and in other embodiments, the fifth indication information and indication of no NG-RAN change can be different information.

[0231] In some embodiments, the response (information) includes N2 SM info, and the N2 SM info includes the above-mentioned PSA tunnel info and the fifth indication information.

[0232] After S708b, S711 to S715 are performed, as shown in Figure 7

[0233] S711: The AMF sends a message (for example, an N2 message) to the NG-RAN, and the message carries at least one of the fifth indication information in S708b and the new I-UPF tunnel info, or at least one of the third indication information in S710a and the PSA tunnel info. ​

[0234] S712: The NG-RAN sends an end marker on the old path.

[0235] It can be understood that when the step S711 does not contain the fifth indication information or the third indication information, the NG-RAN can update the uplink path information according to the reception of the new I-UPF tunnel info or the PSA tunnel info. For example, the NG-RAN updates the uplink path from the old I-UPF to the new I-UPF or the PSA according to the reception of the new I-UPF tunnel info or the PSA tunnel info, and sends an end marker on the old path.

[0236] When the step S711 contains the fifth indication information or the third indication information, the NG-RAN sends an end marker on the old path according to the fifth indication information or the third indication information.

[0237] S713: When the PSA receives the end marker on the old path, the PSA reports a message to the SMF according to the second indication information in the step S708a or the fourth indication information in the step S707b, and the message is used to indicate that the PSA receives the end marker of the uplink data packet on the old path.

[0238] In some embodiments, the message reported by the PSA to the SMF is an end marker (end marker) of the uplink data packet sent on the old path.

[0239] S714: The SMF sends an updated message (for example, N4 rule) to the PSA, and the message is used to indicate that the PSA sends the buffered uplink data packet from the new path (new path) to the N6 interface.

[0240] S715: The PSA sends the buffered uplink data packet from the new path (new path) according to the message.

[0241] It can be understood that for the uplink data packet on the old path, the PSA sends it according to the normal process, that is, after receiving the uplink data packet from the old path, the PSA sends the data packet to the server.

[0242] The method for data packet transmission in a PDU session provided in this application embodiment sorts the uplink data packets received from the same PDU session on both the new and old paths using a PSA. Before the PSA receives an indication that the uplink data packets sent on the old path have been sent, the PSA buffers the uplink data packets received on the new path. After the PSA receives the indication that the uplink data packets sent on the old path have been sent, the PSA sends the previously buffered uplink data packets received on the new path. This ensures that the uplink data packets in a PDU session are sent in the normal order, thereby saving the server's sorting time for uplink data packets and ensuring communication efficiency.

[0243] Figure 9 The illustration shown is a schematic representation of a communication system scenario provided in this application. Figure 10 The example shown is one that can be applied to this application. Figure 9 A schematic flowchart illustrating the method of data packet transmission in a PDU session in the illustrated scenario. In some embodiments. Figure 10 In the method shown, uplink packets from the same PDU session originating from different paths are sorted by new I-UPF or PSA.

[0244] exist Figure 9 In the scenario shown, such as Figure 9 In Figure a, the solid line represents the uplink data packet transmission path on the new path, and the dashed line represents the uplink data packet transmission path on the old path. Figure 9 Figure a shows a scenario where I-UPF exists on the old path. Figure 9 In diagram b, the solid line represents the uplink data packet transmission path on the new path, and the dashed line represents the uplink data packet transmission path on the old path. Figure 9 Figure b shows a scenario where I-UPF does not exist on the old path.

[0245] for Figure 9 In the scenario shown in Figure a, the transmission path of uplink data packets on the old path is: Terminal Device → NG-RAN → Source I-UPF → Target I-UPF → PSA. The transmission path of uplink data packets on the new path is: Terminal Device → NG-RAN → Target I-UPF → PSA. The Target I-UPF sorts the uplink data packets for the same PDU session from both the new and old paths.

[0246] for Figure 9In the scenario shown in FIG. b, the transmission path of the uplink data packet on the old path is: terminal device -> NG-RAN -> PSA -> target I-UPF -> PSA. The transmission path of the uplink data packet on the new path is: terminal device -> NG-RAN -> target I-UPF -> PSA. The target I-UPF sorts the uplink data packets from the same PDU session on the new path and the old path.

[0247] The target I-UPF is a new I-UPF. The source I-UPF is an old I-UPF.

[0248] As shown in FIG. 1, the method comprises the following steps. Figure 10

[0249] S1001: The PCF sends a PCC rule to the SMF.

[0250] Optionally, the PCC rule contains a DNAI.

[0251] For example, in some embodiments, the PCF can send a policy control update notification (Npcf_SM PolicyControl_UpdateNotify) to the SMF through the Npcf interface, and the notification carries the PCC rule.

[0252] S1002: The SMF sends target DNAI information (target DNAI info) to the AMF. The target DNAI info contains a target DNAI (target DNAI), and the target DNAI info is used to instruct the AMF to insert an I-SMF.

[0253] In some embodiments, the SMF first determines the target DNAI, and after determining the target DNAI, the SMF judges that it cannot serve the target DNAI, and then sends the target DNAI to the AMF.

[0254] In some embodiments, the SMF can determine the target DNAI according to the location of the terminal device, the DNAI in step S1001, etc.

[0255] Optionally, when the PCC rule in step S1001 does not contain a DNAI, the target DNAI information sent by the SMF to the AMF in S1002 does not contain the target DNAI.

[0256] ​For example, in some embodiments, the SMF can send a PDU session context status notification (Nsmf_PDUSession_SMContextStatusNotify) to the AMF, which carries the target DNAI info.

[0257] S1003: The AMF selects and inserts a new I-SMF (new I-SMF) according to the target DNAI.

[0258] In some embodiments, S1003 can also be replaced by: when the AMF determines that the SMF can serve the target DNAI according to the target DNAI, or when the AMF does not receive the target DNAI and does not need the I-SMF, the AMF deletes the I-SMF.

[0259] For the scenario of I-SMF / I-UPF insertion and I-SMF / I-UPF change, after S1003, S1004a to S1008a are performed, as shown in Figure 11

[0260] S1004a: The AMF sends a create context request to the new I-SMF, which carries: session identity, session management context identity (SM context ID), terminal device location information (UE location info), target DNAI, indication of no NG-RAN change, etc.

[0261] Optionally, the create context request can also include indication information, which is used to indicate that the uplink data packets need to be sorted.

[0262] In some embodiments, the indication information can be indication of no NG-RAN change, that is, indication of no NG-RAN change can be used to indicate that the access network device has not changed, and can also be used to indicate that the uplink data packets need to be sorted. In the examples of the present application, “the uplink data packets need to be sorted” can also be described as “the uplink data packets need sorting”.

[0263] In other embodiments, the indication information and indication of no NG-RAN change can be different information respectively.

[0264] ​In some embodiments, when the indication information is not carried in the create context request, and the indication of no NG-RAN change is not used to indicate that the uplink data packet needs to be sorted, the new I-SMF can determine that the uplink data packet needs to be sorted according to the indication of no NG-RAN change.

[0265] The session identifier is used to indicate the current PDU session.

[0266] The SM context ID is used to indicate the identity of the source I-SMF. In the I-SMF insertion scenario (i.e., the control plane corresponding to the session is originally: AMF, SMF; after the I-SMF is inserted, it becomes: AMF, new I-SMF, SMF), the SM context ID is used to point to the SMF; in the I-SMF change scenario (i.e., the control plane corresponding to the session is originally: AMF, old I-SMF, SMF; after the I-SMF is inserted, it becomes: AMF, new I-SMF, SMF), the SM context ID is used to point to the old I-SMF.

[0267] The target DNAI is used to represent the MEC platform location.

[0268] The indication of no NG-RAN change is used to represent that the NG-RAN tunnel information (NG-RAN tunnel info) does not change.

[0269] S1005a: The new I-SMF obtains the session management context (SM context) from the old I-SMF or the SMF.

[0270] In some embodiments, for the I-SMF change scenario: the new I-SMF can send a context request to the old I-SMF, carrying the indication of no NG-RAN change.

[0271] Optionally, as one possible implementation, the context request can also include indication information, which is used to instruct the old I-SMF to determine to establish a forwarding tunnel for forwarding the uplink data packet. There are two possible implementation ways as follows:

[0272] Manner one: the indication information can be indication of no NG-RAN change, that is, indication of no NG-RAN change can be used to indicate that the old I-SMF determines to establish the forwarding tunnel.

[0273] Manner two: the indication information and indication of no NG-RAN change can be different information respectively.

[0274] Optionally, as another possible implementation manner: the context request can include indication information, the indication information being used to indicate that the uplink data packet needs to be sorted. There are three possible manners as follows:

[0275] Manner one: the indication information can be indication of no NG-RAN change, that is, indication of no NG-RAN change can be used to indicate that the access network device is unchanged, and can also be used to indicate that the uplink data packet needs to be sorted.

[0276] Manner two: the indication information and indication of no NG-RAN change can be different information respectively.

[0277] Manner 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 packet needs to be sorted, the old I-SMF can determine that the uplink data packet needs to be sorted according to indication of no NG-RAN change.

[0278] After the old I-SMF receives the context request, the context response is returned to the new I-SMF, and the context response carries NG-RAN tunnel information and forwarding indication. The forwarding indication is used to indicate that the forwarding tunnel between the new I-UPF and the old I-UPF is established. Optionally, the context response can also carry the sixth indication information, and the sixth indication information is used to indicate that the forwarding tunnel is used to forward the uplink data packet.

[0279] In some embodiments, when the context request received by the old I-SMF includes the indication of no NG-RAN change, the forwarding indication is included in the context response returned by the old I-SMF.

[0280] In some embodiments, for the I-SMF insertion scenario: the new I-SMF can send a context request to the SMF, which carries the indication of no NG-RAN change.

[0281] Optionally, as a possible implementation manner: the indication information in the context request can also be included, which is used to instruct the SMF to determine to establish a forwarding tunnel for forwarding the uplink data packet, and there are two possible implementation manners as follows:

[0282] Manner one: the indication information can be the indication of no NG-RAN change, that is, the indication of no NG-RAN change can be used to instruct the SMF to determine to establish a forwarding tunnel.

[0283] Manner two: the indication information and the indication of no NG-RAN change can be different information respectively.

[0284] Optionally, as another possible implementation manner: the indication information can be included in the context request, which is used to instruct that the uplink data packet needs to be sorted. There are three possible manners as follows:

[0285] Manner one: the indication information can be the indication of no NG-RAN change, that is, the indication of no NG-RAN change can be used to instruct that the access network device is unchanged, and can also be used to instruct that the uplink data packet needs to be sorted.

[0286] Manner two: the indication information and the indication of no NG-RAN change can be different information respectively.

[0287] Manner three: when the indication information is not carried in the context request, and the indication of no NG-RAN change is not used to instruct that the uplink data packet needs to be sorted, the SMF can determine that the uplink data packet needs to be sorted according to the indication of no NG-RAN change.

[0288] After the SMF receives the request, the SMF returns a context response to the new I-SMF, where the context response carries NG-RAN tunnel info and a forwarding indication. The forwarding indication is used to indicate that a forwarding tunnel between the new I-UPF and the PAS is established. Optionally, the context response can also carry seventh indication information, which is used to indicate that the forwarding tunnel is used to forward uplink data packets.

[0289] In some embodiments, when the context request received by the SMF includes the indication of no NG-RAN change, the context response returned by the SMF includes the forwarding indication.

[0290] S1006a: The new I-SMF selects a new I-UPF and obtains tunnel information of the new I-UPF (new I-UPF tunnel info).

[0291] S1007a: The new I-SMF sends an N4 session establishment request to the new I-UPF, where the request carries NG-RAN tunnel info and indication information, which is used to indicate that the new I-UPF buffers uplink data packets (or also referred to as uplink messages) from the NG-RAN (new path) and reports a message to the SMF when an end marker of the uplink data packets from the PSA or the old I-UPF (old path) is received, where the message is used to indicate that the end marker of the old path is received by the new I-UPF. The end marker is used to indicate that the uplink data packets sent on the old path have been sent.

[0292] In some embodiments, the new I-SMF can determine to send the indication information in S1007a to the new I-UPF according to the indication information in S1004a.

[0293] In some embodiments, the message reported by the new I-UPF to the SMF can be the end marker of the uplink data packets of the old path.

[0294] For the I-SMF change scenario, the uplink data packets received by the new I-UPF on the old path are the uplink data packets received from the old I-UPF. For the I-SMF insertion scenario, the uplink data packets received by the new I-UPF on the old path are the uplink data packets received from the PSA.

[0295] In some embodiments, the N4 session establishment request can comprise an N4 rule, the N4 rule carrying the NG-RAN tunnel info and the indication information in S1007a.

[0296] S1008a: The new I-SMF sends a create context response (Nsmf_PDU Session_CreateSMResponse) to the AMF, carrying the N2 SM info. The N2 SM info contains the new I-UPF tunnel info.

[0297] Optionally, the N2 SM info further comprises eighth indication information. The eighth indication information is used to indicate that the NG-RAN sends an end marker on the old path, and the end marker is used to indicate that the uplink data packets on the old path have been sent.

[0298] In some embodiments, the eighth indication information can be an indication of no NG-RAN change, that is, the indication of no NG-RAN change can be used to indicate the content indicated by the eighth indication information.

[0299] In other embodiments, the eighth indication information and the indication of no NG-RAN change can be different information respectively.

[0300] After S1008a, S1009 to S1013 are performed, as shown in Figure 10 .

[0301] For the I-SMF / I-UPF removal scenario, after S1003, S1004b to S1008b are performed.

[0302] S1004b: The AMF sends an update context request to the SMF. The request carries: a session identity, a session management context identity (SM context ID), terminal device location information (UE location info), a target DNAI, an indication of no NG-RAN change, and the like.

[0303] Optionally, the update context request can further include indication information, which is used to indicate that the uplink data packets need to be sorted.

[0304] In some embodiments, the indication information can be indication of no NG-RAN change, that is, indication of no NG-RAN change can be used to indicate that the access network device has not changed, and can also be used to indicate that the uplink data packets need to be sorted.

[0305] In other embodiments, the indication information and indication of no NG-RAN change can be different information respectively.

[0306] 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 uplink data packets need to be sorted, the SMF can determine that the uplink data packets need to be sorted according to indication of no NG-RAN change.

[0307] S1005b: The SMF obtains the SM context from the old I-SMF.

[0308] In some embodiments, the SMF can send a context request to the old I-SMF, which carries indication of no NG-RAN change. After receiving the request, the old I-SMF sends a context response (information) to the SMF, which includes: NG-RAN tunnel info, forwarding indication.

[0309] Optionally, as a possible implementation manner: the context request can further include indication information, which is used to indicate that the old I-SMF determines to establish a forwarding tunnel for forwarding the uplink data packets, and there are two possible implementation manners as follows:

[0310] Method 1: The indication information can be "indication of no NG-RAN change", that is, "indication of no NG-RAN change" can be used to instruct the old I-SMF to determine to establish a forwarding tunnel.

[0311] Method 2: This instruction and the indication of no NG-RAN change can be different messages.

[0312] Optionally, as another possible implementation, the context request can include indication information indicating that uplink packets need to be sorted. There are three possible approaches:

[0313] Method 1: The indication information can be "indication of no NG-RAN change". That is to say, "indication of no NG-RAN change" can be used to indicate that the access network equipment has not changed, or it can be used to indicate that uplink data packets need to be sorted.

[0314] Method 2: This instruction and the indication of no NG-RAN change can be different messages.

[0315] Method 3: When the context creation request does not carry this indication information, and the indication of no NG-RAN change is not used to indicate that uplink packets need to be sorted, the old I-SMF can determine that uplink packets need to be sorted based on the indication of no NG-RAN change.

[0316] In some embodiments, when the context request received by the old I-SMF includes an indication of no NG-RAN change, the context response returned by the old I-SMF includes a forwarding indication. This forwarding indication is used to indicate the establishment of a forwarding tunnel between the old I-UPF and the PAS. Optionally, the context response may also carry a ninth indication, which indicates that the forwarding tunnel is used for forwarding uplink data packets.

[0317] S1006b: SMF selects and inserts new I-UPF.

[0318] It should be understood that S1006b is an optional step. Figure 10 and Figure 11The flowchart shown is the case including S1006b. When the SMF does not insert the new I-UPF, the new I-UPF is replaced by the PSA.

[0319] In the case where the above steps include S1006b: S1007b is that the SMF sends an N4 session establishment request to the new I-UPF, and the session request carries indication information indicating that the new I-UPF caches uplink data packets from the new path (from the NG-RAN), and when receiving an end marker from the old I-UPF, the new I-UPF sends a reporting message to the SMF, which indicates that the new I-UPF has received the end marker of the uplink data packets on the old path. The end marker is used to indicate that the uplink data packets sent on the old path have been sent. In some embodiments, the SMF can determine to send the indication information in S1007b to the new I-UPF according to the indication information in S1004b.

[0320] In the case where the above steps include S1006b, the old path is: terminal device→NG-RAN→old I-UPF→new I-UPF→PSA; and the new path is: terminal device→NG-RAN→new I-UPF→PSA.

[0321] If the above flowchart does not include S1006b, S1007b is replaced by: the SMF sends an N4 session modification request to the PSA, carrying indication information indicating that the PSA caches uplink data packets from the new path, and when receiving an end marker from the old path, sends a reporting message to the SMF, which indicates that the PSA has received the end marker of the uplink data packets on the old path. In some embodiments, the SMF can determine to send the indication information in S1007b to the PSA according to the indication information in S1004b.

[0322] In the case where the above flowchart does not include S1006b, the old path is: terminal device→NG-RAN→old I-UPF→PSA; and the new path is: terminal device→NG-RAN→PSA.

[0323] In some embodiments, the information that the uplink data packets on the old path have been sent can be an endmarker.

[0324] S1008b: The SMF sends an update context response to the AMF, carrying N2 SM info. The N2 SM info includes new I-UPF tunnel info.

[0325] Optionally, the update context response further comprises tenth indication information. The tenth indication information is used to indicate that the NG-RAN sends an end marker on the old path. The end marker is used to indicate that the uplink data packets on the old path have been sent completely.

[0326] In some embodiments, the tenth indication information can be indication of no NG-RAN change, that is, the indication of no NG-RAN change can be used to indicate the content indicated by the tenth indication information.

[0327] In other embodiments, the tenth indication information and the indication of no NG-RAN change can be different information respectively.

[0328] After S1008b, S1009 to S1013 are executed, as shown in Figure 11

[0329] S1009, the AMF sends an N2 message to the NG-RAN, carrying at least one of the tenth indication information in the above step S1008b and the new I-UPF tunnel info, or at least one of the eighth indication information in the step S1008a and the new I-UPF tunnel info.

[0330] S1010, the NG-RAN sends an end marker on the old path.

[0331] The new I-UPF or the PSA receives the end marker of the uplink data packets on the old path.

[0332] It should be understood that when the NG-RAN receives the tenth indication information or the eighth indication information, the NG-RAN sends an end marker on the old path according to the tenth indication information or the eighth indication information. When the NG-RAN only receives the new I-UPF tunnel info, that is, does not receive the tenth or eighth indication information, the NG-RAN performs uplink path switching 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 marker on the old path. The old path refers to the path between the NG-RAN and the old I-UPF or the PSA.

[0333] ​For I-SMF insertion (i.e. I-UPF insertion) scenario: NG-RAN sends end marker to PSA, PSA sends end marker to new I-UPF via PSA-to-new I-UPF forwarding tunnel.

[0334] For I-SMF change scenario: NG-RAN sends end marker to old I-UPF, old I-UPF sends end marker to new I-UPF via old I-UPF-to-new I-UPF forwarding tunnel.

[0335] For I-SMF remove scenario, including the case of inserting new I-UPF and the case of not inserting new I-UPF:

[0336] In the case of SMF inserting new I-UPF: NG-RAN sends end marker to old I-UPF, old I-UPF sends end marker to new I-UPF via old I-UPF-to-new I-UPF forwarding tunnel.

[0337] In the case of not inserting new I-UPF: NG-RAN sends end marker to old I-UPF, old I-UPF sends end marker to PSA via old I-UPF-to-PSA forwarding tunnel.

[0338] S1011, New I-UPF sends a report message to SMF after receiving the indication information (e.g. end marker) on the old path indicating that the uplink data packet has been sent, according to the N4 session establishment request in S1107a or 1007b. The message is used to indicate that the New I-UPF has received the end marker of the old path.

[0339] In the case where the above process does not include S1006b, S1011 is replaced by: PSA sends a report message to SMF after receiving the indication information (e.g. end marker) on the old path indicating that the uplink data packet has been sent, according to the N4 session establishment request in S1107b. The message is used to indicate that the PSA has received the end marker of the old path.

[0340] S1012, SMF sends an updated N4 rule to New I-UPF, indicating that New I-UPF sends the buffered uplink packets from the new path (new path) to PSA.

[0341] In the case that the above procedure does not include S1006b, S1012 is replaced by: the SMF sends an updated N4 rule to the PSA, to instruct the PSA to send the buffered uplink packets from the new path (new path) out, i.e. to the N6 interface.

[0342] S1013, the New I-UPF sends the buffered uplink packets from the new path (new path) according to the updated N4 rule. It can be understood that for the uplink packets on the old path, the New I-UPF sends them according to the normal procedure, i.e. sends the uplink packets from the old path to the PSA as soon as they are received. Finally, the PSA sends the packets from the new path and the old path to the server after sorting them.

[0343] In the case that the above procedure does not include S1006b, S1013 is replaced by: the PSA sends the buffered uplink packets from the new path (new path) according to the updated N4 rule. It can be understood that for the uplink packets on the old path, the PSA sends them according to the normal procedure, i.e. sends the uplink packets from the old path out as soon as they are received.

[0344] The method for transmitting packets in a PDU session provided by the embodiments of the present application sorts the uplink packets from the new path and the old path of the same PDU session received by the I-UPF or the PSA, buffers the uplink packets received on the new path before the I-UPF or the PSA receives the indication information indicating that the uplink packets sent on the old path have been sent, and sends the buffered uplink packets received on the new path after the I-UPF or the PSA receives the indication information indicating that the uplink packets sent on the old path have been sent, so as to ensure that the uplink packets in a PDU session are sent in the normal order, thereby saving the sorting time of the uplink packets by the server and ensuring the communication efficiency.

[0345] Figure 12 The communication system scenario provided by the embodiments of the present application is shown in the schematic diagram, Figure 13 The communication system provided by the embodiments of the present application can be applied to Figure 12 The method for transmitting packets in a PDU session in the scenario is shown in the schematic flowchart. In some embodiments, in the Figure 13 In the method, the NG-RAN sorts the downlink packets from the same PDU session on different paths.

[0346] In the case that the above procedure does not include S1006b, S1012 is replaced by: the SMF sends an updated N4 rule to the PSA, to instruct the PSA to send the buffered uplink packets from the new path (new path) out, i.e. to the N6 interface. Figure 12In the illustrated scenario, the solid line represents the transmission of downlink packets on the new path, and the dashed line represents the transmission of downlink packets on the old path. The downlink packets on the new path and the downlink packets on the old path are downlink packets included in the same PDU session.

[0347] The transmission path of the downlink packets on the old path is PSA→source I-UPF→NG-RAN→terminal device, and the transmission path of the downlink packets on the new path is PSA→target I-UPF→NG-RAN→terminal device.

[0348] Before the I-SMF or I-UPF change, the source I-UPF is the old I-UPF, and after the I-SMF change, the target I-UPF is the new I-UPF.

[0349] Before the I-SMF or I-UPF insertion, the source I-UPF is the PSA, i.e., the old path becomes PSA→NG-RAN→terminal device. After the I-SMF or I-UPF insertion, the target I-UPF is the new I-UPF.

[0350] Before the I-SMF or I-UPF removal, the source I-UPF is the old I-UPF, and after the I-SMF removal, the target I-UPF is the PSA, i.e., the new path becomes PSA→NG-RAN→terminal device.

[0351] As shown in the figure, the method includes: Figure 13

[0352] S1301: The PCF sends a PCC rule to the SMF.

[0353] Optionally, the PCC rule carries (or contains) the DNAI.

[0354] For example, in some embodiments, the PCF can send a policy control update notification (Npcf_SM PolicyControl_UpdateNotify) to the SMF through the Npcf interface, and the notification carries the PCC rule.

[0355] S1302: The SMF sends target DNAI information (target DNAI info) to the AMF. The target DNAI info contains the target DNAI, and the target DNAI info is used to instruct the AMF to insert the I-SMF. ​

[0356] In some embodiments, the SMF first determines a target DNAI, and after determining the target DNAI, the SMF judges that the target DNAI cannot be served, and the SMF sends the target DNAI to the AMF. For example, the SMF can determine the target DNAI according to the location of the terminal device, the DNAI in step S1301, etc.

[0357] In some embodiments, if the PCC rule in S1301 does not contain the DNAI, then in S1302, the target DNAI info sent by the SMF to the AMF does not contain the target DNAI.

[0358] For example, in some embodiments, the SMF can send a PDU session context status notification (Nsmf_PDUSession_SMContextStatusNotify) to the AMF, and the notification carries the target DNAI info.

[0359] S1303: The AMF selects and inserts a new I-SMF (new I-SMF) according to the target DNAI.

[0360] In some embodiments, S1303 can also be replaced by: when the AMF judges that the SMF can serve the target DNAI according to the target DNAI, or when the AMF does not receive the target DNAI and does not need the old I-SMF, the AMF deletes the old I-SMF.

[0361] S1304: The AMF sends an N2 message to the NG-RAN, and the message carries eleventh indication information. The eleventh indication information is used to instruct the NG-RAN to cache downlink data packets (downlink messages) from non-old paths (i.e. new paths) before the NG-RAN receives an end marker on the old path. The end marker is used to indicate that the downlink data packets received on the old path have been received (or the downlink data packets on the old path have been sent).

[0362] When the NG-RAN receives the end marker on the old path, the NG-RAN sends the cached downlink data packets from non-old paths (i.e. new paths) to the terminal device.

[0363] In some embodiments, the eleventh indication information can be indication of no NG-RAN change, that is, the indication of no NG-RAN change can be used to indicate the content indicated by the eleventh indication information.

[0364] In other embodiments, the eleventh indication information and the indication of no NG-RAN change can be different information respectively.

[0365] In some embodiments, in S1302, the information sent by the SMF to the AMF can also include the eleventh indication information described above, in which case S1302 can be replaced by: the SMF sends a context status notification to the AMF, and the notification carries: target DNAI info, the eleventh indication information, and optionally, the notification can also carry a skip indicator. The skip indicator is used to indicate that the AMF does not send the eleventh indication information to the NG-RAN when the terminal device is in the idle state. If the SMF sends the context status notification to the AMF including the skip indicator, the eleventh indication information described above is not included in the N2 information sent by the AMF to the NG-RAN. In other words, S1304 is an optional step.

[0366] For the scenario of I-SMF / I-UPF insertion and I-SMF / I-UPF change, after S1304, S1305a to S1311a are performed as shown in Figure 14 .

[0367] S1305a: The AMF sends a create context request to the new I-SMF, and the request carries: a session identifier, a session management context identifier (SM context ID), terminal device location information (UE location info), target DNAI, indication of no NG-RAN change, and the like.

[0368] Among them, the session identifier is used to indicate the current PDU session.

[0369] The SM context ID is used to indicate the identity of the source I-SMF. Among them, in the I-SMF insertion scenario (i.e., the control plane corresponding to this session is originally: AMF, SMF; after the insertion of the I-SMF, it becomes: AMF, new I-SMF, SMF), the SM context ID is used to point to the SMF; in the I-SMF change scenario (i.e., the control plane corresponding to this session is originally: AMF, old I-SMF, SMF; after the insertion of the I-SMF, it becomes: AMF, new I-SMF, SMF), the SM context ID is used to point to the old I-SMF.

[0370] Target DNAI is used to represent the MEC platform location.

[0371] indication of no NG-RAN change, which is used to indicate that the NG-RAN tunnel information does not change. When the terminal device is in the connected state, the AMF sends this parameter to the new I-SMF.

[0372] S1306a: The new I-SMF obtains the SM context from the old I-SMF (corresponding to the I-SMF change scenario) or the SMF (corresponding to the I-SMF insertion scenario).

[0373] In some embodiments, for the I-SMF change scenario: the new I-SMF can send a context request to the old I-SMF, carrying the indication of no NG-RAN change. After the old I-SMF receives the context request, it returns a context response to the new I-SMF, which carries: NG-RAN tunnel information (NG-RAN tunnel info). Among them, the NG-RAN tunnel info is included in the SM context.

[0374] In some embodiments, for the I-SMF insertion scenario: the new I-SMF can send a context request to the SMF, which carries the indication of no NG-RAN change. After the SMF receives the request, it returns a context response to the new I-SMF, which carries: NG-RAN tunnel information (NG-RAN tunnel info). Among them, the NG-RAN tunnel info is included in the SM context.

[0375] S1307a: The new I-SMF selects a new I-UPF (new I-UPF), and obtains tunnel information of the new I-UPF (new I-UPF tunnel info).

[0376] S1308a: The new I-SMF sends a PDU session update request or a PDU session creation request to the SMF, carrying: downlink tunnel information of the PSA (new I-UPF tunnel info for PSA).

[0377] Optionally, as a possible implementation manner, the PDU session update request or the PDU session creation request can further include indication information, the indication information being used to indicate that the downlink data packets need to be sorted. There are three possible manners as follows:

[0378] Manner one: the indication information can be the new I-UPF tunnel info for PSA, that is, the new I-UPF tunnel info for PSA can be used for both the downlink tunnel information of the PSA and the indication that the downlink data packets need to be sorted.

[0379] Manner two: the indication information and the downlink tunnel information of the PSA can be different information respectively.

[0380] Manner three: when the PDU session update request or the PDU session creation request does not carry the indication information, and the new I-UPF tunnel info for PSA is not used to indicate that the downlink data packets need to be sorted, the SMF can determine that the downlink data packets need to be sorted according to the new I-UPF tunnel info for PSA.

[0381] In some embodiments, the sending of the downlink data packets on the old path can also be described as: the PSA is updated from the old path to the new path. For example, when the PSA receives the new I-UPF tunnel info for PSA, the path of the PSA and the old I-UPF is replaced by the path of the PSA and the new I-UPF.

[0382] The SMF determines, according to the indication information in S1308a, that the PSA sends an end marker on the old path.

[0383] S1309a: The SMF sends the new I-UPF tunnel info for PSA to the PSA.

[0384] The PSA determines to send an end marker on the old path according to the new I-UPF tunnel info for PSA.

[0385] Optionally, the SMF can further send indication information to the PSA, where the indication information is used to instruct the PSA to send an end marker on the old path.

[0386] In some embodiments, the indication information can be the new I-UPF tunnel info for PSA, that is, the new I-UPF tunnel info for PSA can be used to update the downlink tunnel information of the PSA, and can also be used to instruct the PSA to send an end marker on the old path. In other words, the PSA determines to send an end marker on the old path according to the new I-UPF tunnel info for PSA.

[0387] In other embodiments, the indication information and the new I-UPF tunnel info for PSA can be different information respectively.

[0388] After the PSA receives the new I-UPF tunnel info for PSA, when the downlink data packets on the old path are sent, the PSA sends an end marker on the old path (i.e., to the NG-RAN or the old I-UPF), and the old I-UPF forwards the end marker to the NG-RAN after receiving the end marker.

[0389] S1310a: The SMF sends a PDU session update response or a PDU session creation response to the new I-SMF.

[0390] S1311a: The new I-SMF sends a create context response to the AMF, where the response carries updated uplink tunnel information (new I-UPF tunnel info for NG-RAN) of the NG-RAN.

[0391] The new I-UPF tunnel info for NG-RAN is used to update the uplink tunnel information of the NG-RAN.

[0392] In some embodiments, the create context response (information) carries N2 SM info, and the N2 SM info includes the information described above.

[0393] After S1311a, S1312 is performed, as shown in Figure 13

[0394] For the scenario of I-SMF / I-UPF remove, after S1304, S1305b-S1309b are performed, as shown in Figure 14

[0395] S1305b: The AMF sends an update context request to the SMF, which carries: session identity, SM context ID, UE location information, target DNAI, indication of no NG-RAN change, etc.

[0396] S1306b: The SMF obtains the SM context from the old I-SMF.

[0397] In some embodiments, the SMF can send a context request to the old I-SMF, carrying the indication of no NG-RAN change. After receiving the context request, the old I-SMF can return the session management context (SM context) to the SMF, which includes the NG-RAN tunnel information.

[0398] S1307b: The SMF selects a new I-UPF, and obtains the new I-UPF tunnel information for PSA and the new I-UPF tunnel information for NG-RAN.

[0399] Among them, the new I-UPF tunnel information for PSA is used to update the downlink tunnel information of the PSA; the new I-UPF tunnel information for NG-RAN is used to update the uplink tunnel information of the NG-RAN.

[0400] Optionally, as a possible implementation manner, the update context request sent by the AMF to the SMF can further include indication information, which is used to indicate that the downlink data packets need to be sorted. There are three possible ways as follows:

[0401] ​​Method 1: This indication information can be "indication of no NG-RAN change." That is, "indication of no NG-RAN change" can indicate either that the access network equipment remains unchanged, or that downlink data packets need to be sorted. "Downlink data packets need to be sorted" can also be described as "downlink data packets need to be sorted."

[0402] Method 2: This instruction and the indication of no NG-RAN change can be different messages.

[0403] Method 3: When the AMF sends an update context request to the SMF without carrying this indication information but carries an indication of no NG-RAN change, and the indication of no NG-RAN change is not used to indicate that downlink data packets need to be sorted, the SMF can determine that downlink data packets need to be sorted based on the indication of no NG-RAN change.

[0404] It should be understood that S1307b is an optional step.

[0405] Based on the instructions from the AMF, the SMF determines to instruct the PSA to send an endmarker on the old path.

[0406] S1308b: SMF sends to PSA: new I-UPF tunnel info for PSA.

[0407] Based on the new I-UPF tunnel info for PSA, PSA determines to send an endmarker on the old path.

[0408] Optionally, the SMF can also send an indication message to the PSA, which indicates that the PSA should send an end marker on the old path.

[0409] In some embodiments, the indication information can be new I-UPF tunnel info for PSA. That is, new I-UPF tunnel info for PSA can be used to update the downlink tunnel information of PSA, or it can be used to instruct PSA to send an end marker on the old path.

[0410] In some embodiments, the indication information and the new I-UPF tunnel info for PSA can be different information.

[0411] After the PSA receives the new I-UPF tunnel info for PSA, when the downlink data packets on the old path are sent, the PSA sends an end marker on the old path (i.e., to the old I-UPF).

[0412] After the old I-UPF receives the end marker, the old I-UPF forwards the end marker to the NG-RAN.

[0413] S1309b: The SMF sends an update context response information to the AMF, and the response information carries: the updated uplink tunnel information of the NG-RAN (new I-UPF tunnel info for NG-RAN).

[0414] After S1309b, S1312 is performed, as shown in Figure 13 .

[0415] S1312: Before the NG-RAN receives the end marker (of the downlink data packets sent on the old path, from the old I-UPF or the PSA), when the NG-RAN receives the downlink data packets on the new path, the NG-RAN buffers the downlink data packets (from the new I-UPF or the PSA) received on the new path according to the eleventh indication information in step S1304. When the end marker (of the downlink data packets sent on the old path) is received, the NG-RAN sends the buffered downlink data packets from the new path to the terminal device.

[0416] It can be understood that for the downlink data packets on the old path, the NG-RAN sends them according to the normal process, i.e., after receiving the uplink data packets from the old path, the NG-RAN sends the data packets to the terminal device.

[0417] The method for data packet transmission in a PDU session provided in this application embodiment sorts the downlink data packets received from the same PDU session on both the new and old paths using NG-RAN. Before NG-RAN receives an indication (e.g., an end marker) that the data packets sent on the old path have been completed, NG-RAN buffers the downlink data packets received on the new path. After NG-RAN receives the indication that the downlink data packets sent on the old path have been completed, NG-RAN sends the previously buffered downlink data packets received on the new path. For downlink data packets on the old path, NG-RAN sends them according to the normal procedure. This ensures that downlink data packets in a PDU session are sent in the correct order, thereby guaranteeing the message order of the PDU session and ensuring communication efficiency.

[0418] Figure 15 The illustration shown is a schematic representation of a communication system scenario provided in this application. Figure 16 The example shown is one that can be applied to this application. Figure 15 A schematic flowchart illustrating the method of data packet transmission in a PDU session in the illustrated scenario. In some embodiments. Figure 16 In the method shown, the target I-UPF or PSA sorts downlink packets of the same PDU session from different paths.

[0419] exist Figure 15 In the scene shown, Figure 15 In Figure a, the solid line represents the downlink data packet transmission path on the new path, and the dashed line represents the downlink data packet transmission path on the old path. Figure 15 Figure a shows a scenario where I-UPF exists on the old path. Figure 15 In diagram b, the solid line represents the downlink data packet transmission path on the new path, and the dashed line represents the downlink data packet transmission path on the old path. Figure 15 Figure b shows a scenario where I-UPF does not exist on the old path.

[0420] for Figure 15 In the scenario shown in Figure a, the transmission path of downlink data packets on the old path is: PSA → Source I-UPF → Target I-UPF → NG-RAN → Terminal Equipment. The transmission path of downlink data packets on the new path is: PSA → Target I-UPF → NG-RAN → Terminal Equipment. The Target I-UPF sorts downlink data packets from the same PDU session originating from both the old and new paths.

[0421] for Figure 15In the scenario shown in FIG. b, the transmission path of the downlink data packet on the old path is: PSA→NG-RAN→target I-UPF→NG-RAN→PSA→terminal device. The transmission path of the downlink data packet on the new path is: PSA→target I-UPF→NG-RAN→terminal device. The target I-UPF sorts the downlink data packets from the same PDU session on the new path and the old path.

[0422] In the scenario shown in FIG. b, the transmission path of the downlink data packet on the old path is: PSA→NG-RAN→target I-UPF→NG-RAN→PSA→terminal device. The transmission path of the downlink data packet on the new path is: PSA→target I-UPF→NG-RAN→terminal device. The target I-UPF sorts the downlink data packets from the same PDU session on the new path and the old path.

[0423] As shown in FIG. b, the method comprises the following steps. Figure 16

[0424] S1601: The PCF sends a PCC rule to the SMF.

[0425] Optionally, the PCC rule carries (or contains) the DNAI.

[0426] For example, in some embodiments, the PCF can send a policy control update notification (Npcf_SM PolicyControl_UpdateNotify) to the SMF through the Npcf interface, and the notification carries the PCC rule.

[0427] S1602: The SMF sends target DNAI information (target DNAI info) to the AMF. The target DNAI info contains the target DNAI, and the target DNAI info is used to instruct the AMF to insert the I-SMF.

[0428] In some embodiments, the SMF first determines the target DNAI, and after determining the target DNAI, the SMF judges that it cannot serve the target DNAI, and then sends the target DNAI to the AMF. For example, the SMF can determine the target DNAI according to the location of the terminal device, the DNAI in step S1601, etc.

[0429] In some embodiments, if the PCC rule in S1601 does not contain the DNAI, then in S1602, the target DNAI info sent by the SMF to the AMF does not contain the target DNAI.

[0430] ​For example, in some embodiments, the SMF can send a PDU session context status notification (Nsmf_PDUSession_SMContextStatusNotify) to the AMF, which carries the target DNAI info.

[0431] S1603: The AMF selects and inserts a new I-SMF (new I-SMF) according to the target DNAI.

[0432] In some embodiments, S1603 can also be replaced by: when the AMF determines that the SMF can serve the target DNAI according to the target DNAI, or when the AMF does not receive the target DNAI and does not need the old I-SMF, the AMF deletes the old I-SMF.

[0433] For the scenarios of I-SMF / I-UPF insertion and I-SMF / I-UPF change, S1604a to S1611a are performed, as shown in Figure 17

[0434] S1604a: The AMF sends a create context request to the new I-SMF, which carries: session identity, session management context identity (SM context ID), terminal device location information (UE location info), target DNAI, indication of no NG-RAN change, etc.

[0435] Optionally, the create context request can also include indication information, which is used to indicate that the downlink data packets need to be sorted.

[0436] In some embodiments, the indication information can be indication of no NG-RAN change, that is, indication of no NG-RAN change can be used to indicate that the access network device has not changed, and can also be used to indicate that the downlink data packets need to be sorted.

[0437] In other embodiments, the indication information and indication of no NG-RAN change can be different information respectively.

[0438] ​In some embodiments, when the indication information is not carried in the context request, and the indication of no NG-RAN change is not used to indicate that the downlink data packets need to be sorted, the SMF can determine that the downlink data packets need to be sorted according to the indication of no NG-RAN change.

[0439] S1605a: The new I-SMF obtains a session management context (SM context) from the old I-SMF or the SMF.

[0440] In some embodiments, for the I-SMF change scenario: the new I-SMF can send a context request to the old I-SMF, carrying the indication of no NG-RAN change.

[0441] Optionally, as a possible implementation manner: the context request can further include indication information, which is used to instruct the old I-SMF to determine to establish a forwarding tunnel for forwarding the downlink data packets. There are two possible implementation manners as follows:

[0442] Manner one: the indication information can be the indication of no NG-RAN change, that is, the indication of no NG-RAN change can be used to instruct the old I-SMF to determine to establish the forwarding tunnel.

[0443] Manner two: the indication information and the indication of no NG-RAN change can be different information respectively.

[0444] Optionally, as another possible implementation manner: the context request can include indication information, which is used to indicate that the downlink data packets need to be sorted. There are three possible manners as follows:

[0445] Manner one: the indication information can be the indication of no NG-RAN change, that is, the indication of no NG-RAN change can be used to instruct the access network device to be unchanged, and can also be used to instruct that the downlink data packets need to be sorted.

[0446] Manner two: the indication information and the indication of no NG-RAN change can be different information respectively.

[0447] Option 3: When the indication information is not carried in the context request, and indication of no NG-RAN change is not used to indicate that the downlink data packet needs to be sorted, the old I-SMF can determine that the downlink data packet needs to be sorted according to indication of no NG-RAN change.

[0448] After the old I-SMF receives the context request, the old I-SMF returns a context response to the new I-SMF, and the context response carries NG-RAN tunnel information (NG-RAN tunnel info) and forwarding indication. The forwarding indication is used to indicate that a forwarding tunnel between the new I-UPF and the old I-UPF is established. Optionally, the context response can also carry twelfth indication information, and the twelfth indication information is used to indicate that the forwarding tunnel is used to forward the downlink data packet.

[0449] In some embodiments, when the context request received by the old I-SMF includes indication of no NG-RAN change, the context response returned by the old I-SMF includes the forwarding indication.

[0450] In some embodiments, for the I-SMF insertion scenario: the new I-SMF can send a context request to the SMF, and the request carries indication of no NG-RAN change.

[0451] Optionally, as a possible implementation manner: the context request can also include indication information, and the indication information is used to indicate that the SMF determines to establish a forwarding tunnel, and the forwarding tunnel is used to forward the downlink data packet. There are two possible implementation manners as follows:

[0452] Option 1: The indication information can be indication of no NG-RAN change, that is, indication of no NG-RAN change can be used to indicate that the SMF determines to establish the forwarding tunnel.

[0453] Option 2: The indication information and indication of no NG-RAN change can be different information respectively.

[0454] Optionally, as another possible implementation manner, the indication information indicating that the downlink data packets need to be sorted can be included in the context request. There are three possible manners as follows.

[0455] Manner one: the indication information can be indication of no NG-RAN change, that is, the indication of no NG-RAN change can be used to indicate that the access network device is unchanged, and can also be used to indicate that the downlink data packets need to be sorted.

[0456] Manner two: the indication information and the indication of no NG-RAN change can be different information respectively.

[0457] Manner three: when the indication information is not carried in the context request, and the indication of no NG-RAN change is not used to indicate that the downlink data packets need to be sorted, the SMF can determine that the downlink data packets need to be sorted according to the indication of no NG-RAN change.

[0458] After the SMF receives the request, the SMF returns a context response to the new I-SMF, and the NG-RAN tunnel information and the forwarding indication are carried in the response. The forwarding indication is used to indicate that the forwarding tunnel between the NG-RAN and the PSA is established. Optionally, the thirteenth indication information can also be carried in the context response, and the thirteenth indication information is used to indicate that the forwarding tunnel is used to forward the downlink data packets.

[0459] In some embodiments, when the context request received by the SMF includes the indication of no NG-RAN change, the forwarding indication is included in the context response returned by the SMF.

[0460] The new I-SMF determines, according to the indication information in S1604a, that the new I-UPF buffers the downlink data packets from the new path (i.e., from the PSA), and reports a message to the SMF when an end marker from the old path is received.

[0461] S1606a: The new I-SMF selects a new I-UPF (new I-UPF), and sends indication information to the new I-UPF, where the indication information is used to instruct the new I-UPF to cache downlink data packets from a new path (i.e., from the PSA), and when an end marker from an old path is received, report a message to the SMF, where the message is used to indicate that the new I-UPF has received the end marker of the downlink data packets on the old path. The new I-UPF reports to the SMF that the downlink data packets on the old path have been sent. That is, when the new I-UPF receives the end marker of the downlink data packets 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 downlink data packets on the old path have been sent.

[0462] S1607a: The new I-UPF sends response information to the new I-SMF, where the response information carries: new I-UPF tunnel info for NG-RAN, new I-UPF tunnel info for PSA, and new I-UPF tunnel info for forwarding.

[0463] Among them, the new I-UPF tunnel info for PSA is used to update 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; and the new I-UPF tunnel info for forwarding is used to establish a forwarding tunnel between the new I-UPF and the old I-UPF.

[0464] S1608a: The new I-SMF sends an update context request to the old I-SMF, carrying the new I-UPF tunnel info for forwarding.

[0465] S1609a: The old I-SMF sends the new I-UPF tunnel info for forwarding to the old I-UPF.

[0466] 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.

[0467] S1611a: The new I-SMF sends a create request (I-SMF insertion scenario) or an update request (I-SMF change scenario) to the SMF, the create request or the update request carrying: new I-UPF tunnel info for PSA.

[0468] Optionally, as a possible implementation manner, the session update request or the session create request can further include indication information, the indication information being used to indicate that the downlink data packets need to be sorted. There are three possible manners as follows.

[0469] Manner one: the indication information can be the new I-UPF tunnel info for PSA, that is, the new I-UPF tunnel info for PSA can be used to update the downlink tunnel information of the PSA, and can also be used to indicate that the downlink data packets need to be sorted.

[0470] Manner two: the indication information and the downlink tunnel information used to update the PSA can be different information respectively.

[0471] Manner three: when the indication information is not carried in the PDU session update request or the PDU session create request, and the new I-UPF tunnel info for PSA is not used to indicate that the downlink data packets need to be sorted, the SMF can determine that the downlink data packets need to be sorted according to the new I-UPF tunnel info for PSA.

[0472] The SMF determines, according to the indication information in S1611a, that the PSA sends an end marker on the old path.

[0473] S1612a: The SMF sends the new I-UPF tunnel info for PSA to the PSA.

[0474] The PSA determines, according to the new I-UPF tunnel info for PSA, that an end marker is sent on the old path.

[0475] Optionally, the SMF can further send indication information to the PSA, the indication information being used to indicate that the PSA sends an end marker on the old path.

[0476] In some embodiments, the indication information can be new I-UPF tunnel info for PSA, that is, the new I-UPF tunnel info for PSA can be used to update the downlink tunnel information of the PSA, or can be used to indicate that the PSA sends an end marker on the old path.

[0477] In other embodiments, the indication information and the new I-UPF tunnel info for PSA can be different information respectively.

[0478] S1613a: The SMF returns a creation / update response to the new I-SMF.

[0479] S1614a: The new I-SMF returns a creation context response to the AMF, carrying N2 SM info. The N2 SM info includes: new I-UPF tunnel info for NG-RAN.

[0480] After S1614a, S1615 to S1617 are performed, as shown in Figure 16 .

[0481] For the scenario of I-SMF / I-UPF removal, S1604b to S1612b are performed after S1603, as shown in Figure 18 .

[0482] S1604b: The AMF sends an update context request to the SMF. The request carries: session identifier, session management context identifier (SM context ID), terminal device location information (UE location info), target DNAI, indication of no NG-RAN change, etc.

[0483] Optionally, the update context request can also include indication information, which is used to indicate that the downlink data packets need to be sorted.

[0484] In some embodiments, the indication information can be indication of no NG-RAN change, that is, the indication of no NG-RAN change can be used to indicate that the access network device is unchanged, or can be used to indicate that the downlink data packets need to be sorted.

[0485] In some embodiments, the indication information and the indication of no NG-RAN change can be different information respectively.

[0486] In some embodiments, when the indication information is not carried in the create context request, and the indication of no NG-RAN change is not used to indicate that the downlink data packets need to be sorted, the SMF can determine, according to the indication of no NG-RAN change, that the downlink data packets need to be sorted.

[0487] S1605b: The SMF obtains the SM context from the old I-SMF.

[0488] In some embodiments, the SMF can send a context request to the old I-SMF, and the request carries the indication of no NG-RAN change.

[0489] Optionally, as a possible implementation manner, the context request can further include indication information, and the indication information is used to instruct the old I-SMF to determine to establish a forwarding tunnel for forwarding the downlink data packets. There are two possible implementation manners as follows:

[0490] Manner one: the indication information can be the indication of no NG-RAN change, that is, the indication of no NG-RAN change can be used to instruct the old I-SMF to determine to establish the forwarding tunnel.

[0491] Manner two: the indication information and the indication of no NG-RAN change can be different information respectively.

[0492] Optionally, as another possible implementation manner, the context request can include indication information, and the indication information is used to instruct that the downlink data packets need to be sorted. There are three possible manners as follows:

[0493] Manner one: the indication information can be the indication of no NG-RAN change, that is, the indication of no NG-RAN change can be used to instruct that the access network device is unchanged, or can be used to instruct that the downlink data packets need to be sorted.

[0494] Manner two: the indication information and the indication of no NG-RAN change can be different information respectively.

[0495] In a third way, when the indication information is not carried in the context request, and the indication of no NG-RAN change is not used to indicate that the downlink data packets need to be sorted, the old I-SMF can determine that the downlink data packets need to be sorted according to the indication of no NG-RAN change.

[0496] After the old I-SMF receives the request, the old I-SMF sends a context response (information) to the SMF, and the response (information) includes: NG-RAN tunnel info, and forwarding indication. The forwarding indication is used to indicate that a forwarding tunnel between the PSA and the old I-UPF is established.

[0497] In some embodiments, when the context request received by the old I-SMF includes the indication of no NG-RAN change, the forwarding indication is included in the context response returned by the old I-SMF.

[0498] Optionally, the context response can also carry fourteenth indication information, and the fourteenth indication information is used to indicate that the forwarding tunnel is used to forward the downlink data packets.

[0499] S1606b: The SMF selects and inserts the new I-UPF, and obtains new I-UPF tunnel info.

[0500] Optionally, S1606b is an optional step.

[0501] S1607b: The SMF sends PSA tunnel info of the PSA to the new I-UPF.

[0502] S1608b: The new I-UPF returns new I-UPF tunnel info for PSA, new I-UPF tunnel info for forwarding, and new I-UPF tunnel info for NG-RAN to the SMF.

[0503] The new I-UPF tunnel info for PSA is used to update 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; and the new I-UPF tunnel info for forwarding is used to establish a forwarding tunnel between the NG-RAN F and the new I-UPF.

[0504] It can be understood that when the SMF does not insert the new I-UPF, the forwarding tunnel is located between the old I-UPF and the PSA.

[0505] The SMF can determine, according to the indication information in S1604b, that the new I-UPF buffers downlink data packets from a new path (i.e., from the PSA) and reports a message to the SMF when an end marker from the old path is received.

[0506] S1609b: The SMF sends indication information to the new I-UPF, which is used to instruct the new I-UPF to buffer downlink data packets from the PSA and instruct the new I-UPF to report a message to the SMF when the end marker is received, the message being used to indicate that the new I-UPF has received an end marker of a downlink data packet on the old path. That is, when the new I-UPF receives an end marker of a downlink data packet from the old I-UPF, the new I-UPF reports to the SMF that the downlink data packet on the old path has been sent completely.

[0507] S1610b: The SMF sends the 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.

[0508] S1611b: The SMF sends the new I-UPF tunnel info for PSA to the PSA.

[0509] The PSA determines, according to the new I-UPF tunnel info for PSA, to send an end marker on the old path.

[0510] Optionally, the SMF can also send indication information to the PSA, which is used to instruct the PSA to send an end marker on the old path.

[0511] In some embodiments, the indication information can be new I-UPF tunnel info for PSA, that is, the new I-UPF tunnel info for PSA can be used to update the downlink tunnel information of PSA, or can be used to indicate that PSA sends an end marker on the old path.

[0512] In other embodiments, the indication information and the new I-UPF tunnel info for PSA can be different information respectively.

[0513] In some embodiments, when the PSA receives the new I-UPF tunnel info for PSA, the PSA will update the downlink path, and the old path between the PSA and the old I-UPF is updated to a new path between the PSA and the new I-UPF. The PSA sends an end marker of the downlink data packet on the old path, that is, the PSA sends the end marker of the downlink data packet to the old I-UPF, and after the old I-UPF receives the end marker, the old I-UPF forwards the end marker to the new I-UPF through a forwarding tunnel between the old I-UPF and the new I-UPF.

[0514] S1612b: The SMF returns an update context response to the AMF, carrying N2 SM info. The N2 SM info includes: new I-UPF tunnel info for NG-RAN.

[0515] After S1612b, S1615 to S1617 are performed, as shown in Figure 16 .

[0516] S1615: When the new I-UPF receives a downlink data packet from the old I-UPF or the NG-RAN, according to the indication information in steps S1606a or S1609b, the downlink data packet is buffered.

[0517] S1616: When the new I-UPF receives an end marker of downlink data transmission on the old path, according to the indication information in steps S1606a or S1609b, a report message is sent to the SMF, which is used to indicate that the new I-UPF has received the end marker of the downlink data packet on the old path.

[0518] In some embodiments, when the new I-UPF receives an end marker of downlink data transmission from the old I-UPF (I-SMF change / remove scenario) or NG-RAN (I-SMF insert scenario), the new I-UPF can report the end marker to the new I-SMF (I-SMF change / insertion scenario) or SMF (I-SMF remove scenario).

[0519] S1617: The SMF sends an updated N4 rule to the new I-UPF to instruct the new I-UPF to send the buffered downlink data packets.

[0520] It can be understood that, for the downlink data packets on the old path, the new I-UPF sends them according to the normal process, i.e., after receiving the uplink data packets from the old path, the new I-UPF sends the data packets to the terminal device.

[0521] In some embodiments, when the New I-SMF receives the 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 packets to the NG-RAN, and the NG-RAN sends the data packets to the terminal device. For the downlink data packets on the old path, the new I-UPF sends them according to the normal process, i.e., after receiving the uplink data packets from the old path, the new I-UPF sends the data packets to the NG-RAN, and the NG-RAN sends the data packets to the terminal device.

[0522] In the I-SMF remove scenario, and when the SMF does not insert the new I-UPF, the PSA performs the following process for the sorting of downlink data packets:

[0523] When the PSA receives a downlink data packet from the new path (from the N6 interface), the PSA buffers the downlink data packet.

[0524] When the PSA receives an end marker of downlink data transmission from the old path, i.e., the PSA receives an end marker of downlink data transmission sent by the old I-UPF, the PSA reports the end marker to the SMF.

[0525] The SMF sends an updated N4 rule to the PSA to instruct the PSA to send the buffered downlink data packets. For downlink data packets on the old path, the PSA sends the data packets according to the normal process, that is, the PSA sends the uplink data packets from the old path to the terminal device.

[0526] The method for transmitting data packets in a PDU session provided by the embodiments of the present application sorts the received downlink data packets from the same PDU session on the new path and the old path 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 have been sent, the I-UPF or the PSA buffers the received downlink data packets 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 have been sent, the I-UPF or the PSA sends the buffered downlink data packets received on the new path, so that the uplink data packets in a PDU session can be sent in the normal order, thereby ensuring the communication efficiency.

[0527] It should be understood that the above is only to help those skilled in the art better understand the embodiments of the present application, and is not intended to limit the scope of the embodiments of the present application. Those skilled in the art can obviously make various equivalent modifications or changes according to the above examples given, for example, some steps in each of the above methods can be unnecessary, or some steps can be newly added, etc. Or a combination of any two or more embodiments. Such modifications, changes or combinations also fall within the scope of the embodiments of the present application.

[0528] It should also be understood that the ways, cases, categories and divisions of embodiments in the embodiments of the present application are only for the convenience of description and should not be considered as special limitations. The features in various ways, categories, cases and embodiments can be combined without contradiction.

[0529] It should also be understood that the various numerical designations involved in the embodiments of the present application are only for the convenience of description and do not limit the scope of the embodiments of the present application. The size of the serial number of each process does not mean the order of execution, and the execution order of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0530] It should also be understood that the above description of the embodiments of the present application focuses on the differences between the various embodiments, and the same or similar parts not mentioned can be referred to each other. For the sake of brevity, they will not be repeated here.

[0531] The embodiments can divide the functional modules of each network element (including the PSA, the I-UPF (for example, a new I-UPF), the access network device, the new I-SMF, the SMF, and the like) according to the method described above. For example, each functional module can be divided according to each function, or two or more functions can be integrated in one processing module. The integrated module can be implemented in the form of hardware. It should be noted that the division of the modules in the embodiments is illustrative, and is only a logical function division. In actual implementation, another division manner can be used.

[0532] It should be noted that the related content of each step involved in the method embodiments described above can be cited in the function description of the corresponding functional module, and will not be described here.

[0533] The PSA, the I-UPF, the access network device, the new I-SMF, the SMF, and the like provided by the embodiments of the present application are used to execute the method for transmitting a data packet in any one of the PDU sessions provided by the method embodiments described above, and thus the same effect as the implementation method described above can be achieved. In the case of using an integrated unit, the PSA, the I-UPF, the access network device, the new I-SMF, or the SMF can include a processing module, a storage module, and a communication module. The processing module can be used to control and manage the actions of the network element. For example, it can be used to support the network element to execute the steps executed by the processing unit. The storage module can be used to support the storage of program codes and data, and the like. The communication module can be used to support the communication between the network element and other devices.

[0534] The processing module can be a processor or a controller. It can implement or execute various exemplary logical blocks, modules, and circuits described in combination with the disclosure of the present application. The processor can also be a combination of computing functions, such as a combination of one or more microprocessors, a combination of a digital signal processing (DSP) and a microprocessor, and the like. The storage module can be a memory. The communication module can be a device for interacting with other terminal devices, such as a radio frequency circuit, a Bluetooth chip, a Wi-Fi chip, and the like.

[0535] Figure 19 A schematic block diagram of an example communication apparatus provided by the embodiments of the present application is shown. The communication apparatus 1900 can correspond to the PSA, the I-UPF, the access network device, the new I-SMF, or the SMF described in the method embodiments described above. It can also be a chip or component applied to the PSA, the I-UPF, the access network device, the new I-SMF, or the SMF, and each module or unit in the communication apparatus 1900 is respectively used to execute each action or processing process performed by the PSA, the I-UPF, the access network device, the new I-SMF, or the SMF described in the method embodiments described above, such as Figure 19As shown, the communication apparatus 1900 can include a processing unit 1910 and a communication unit 1920. Optionally, the communication apparatus 1900 can further include a storage unit 1930.

[0536] It should be understood that the specific processes by which the units in the communication apparatus 1900 perform the corresponding steps described above can refer to the related descriptions of the steps performed by the PSA, the I-UPF, the access network device, the new I-SMF, or the SMF in various embodiments described in the foregoing Figure 6 and Figure 18 For brevity, the related descriptions of the steps performed by the PSA, the I-UPF, the access network device, the new I-SMF, or the SMF in various embodiments described in the foregoing

[0537] Optionally, the communication unit 1920 can include a receiving unit (module) and a sending unit (module) for performing the steps of receiving information and sending information by the PSA, the I-UPF, the access network device, the new I-SMF, or the SMF in various method embodiments described above. The storage unit 1930 is configured to store instructions for execution by the processing unit 1910 and the communication unit 1920. The processing unit 1910, the communication unit 1920, and the storage unit 1930 are communicatively connected, the storage unit 1930 stores instructions, the processing unit 1910 is configured to execute the instructions stored in the storage unit, and the communication unit 1920 is configured to perform specific signal transceiving under the driving of the processing unit 1910.

[0538] It should be understood that the communication unit 1920 can be a transceiver, an input / output interface, or an interface circuit, and the storage unit can be a memory, and the processing unit 1910 can be implemented by a processor. Figure 20 Another example of a schematic structural block diagram of a communication apparatus provided in the present application is shown in Figure 20 As shown, the communication apparatus 2000 can include a processor 2010, a memory 2020, a transceiver 2030, and a bus system 2040. The various components of the communication apparatus 2000 are coupled together by the bus system 2040, which can include, in addition to a data bus, a power bus, a control bus, and a state signal bus. However, for the sake of clarity, all of the buses are depicted as the bus system 2040 in Figure 20 For the sake of clarity, only the bus system 2040 is schematically shown in Figure 20

[0539] It should also be understood that the communication apparatus 2000 described above Figure 20 may be the PSA, the I-UPF, the access network device, the new I-SMF, or the SMF, or alternatively, the PSA, the I-UPF, the access network device, the new I-SMF, or the SMF can include the communication apparatus 2000. Figure 20

[0540] Figure 19 the communication apparatus 1900 or Figure 20 ​​The communication device 2000 is capable of achieving the aforementioned Figure 6 to Figure 18 The steps performed by the PSA, I-UPF, access network device, new I-SMF, or SMF in the illustrated embodiments are described below. Similar descriptions can be found in the corresponding methods described above. To avoid repetition, they will not be repeated here.

[0541] This application also provides a chip system, such as... Figure 21 As shown, the chip system includes at least one processor 2110 and at least one interface circuit 2120. The processor 2110 and the interface circuit 2120 are interconnected via lines. For example, the interface circuit 2120 can be used to receive signals from other devices. Or, for example, the interface circuit 2120 can be used to send signals to other devices. Exemplarily, the interface circuit 2120 can read instructions stored in memory and send those instructions to the processor 2110. When the instructions are executed by the processor 2110, the chip system can perform the steps of the PSA, I-UPF, access network device, new I-SMF, or SMF execution described in the above embodiments. Of course, the chip system may also include other discrete devices, which are not specifically limited in this application embodiment.

[0542] It should also be understood that the division of the units in the above apparatus is only a logical functional division, and all or part of them can be integrated into a physical entity or physically separated when actually implemented. The units in the apparatus can all be implemented in the form of software invoked by a processing element; or all be implemented in the form of hardware; or some units are implemented in the form of software invoked by a processing element and some units are implemented in the form of hardware. For example, each unit can be a separately established processing element, or can be integrated into a chip of the apparatus, and in addition, can be stored in the form of a program in a memory, and the function of the unit is invoked and executed by a processing element of the apparatus. Here, the processing element can also be referred to as a processor, which can be an integrated circuit with signal processing capability. In the implementation process, each step of the above method or each unit above can be implemented by integrated logic circuits of hardware in the processing element or in the form of software invoked by the processing element. In one example, the units in any of the above apparatuses can be one or more integrated circuits configured to implement the above methods, such as one or more application specific integrated circuits (ASICs), or one or more digital signal processors (DSPs), or one or more field programmable gate arrays (FPGAs), or a combination of at least two of these integrated circuit forms. For another example, when the units in the apparatus can be implemented in the form of a program invoked by a processing element, the processing element can be a general-purpose processor, such as a central processing unit (CPU) or other processor that can invoke a program. For another example, these units can be integrated together to implement in the form of a system on a chip (SOC).

[0543] Embodiments of the present application also provide a device, which is included in a PSA, an I-UPF, an access network device, a new I-SMF, or an SMF, and has the function of the PSA, the I-UPF, the access network device, the new I-SMF, or the SMF in any of the above methods. The function can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes at least one module or unit corresponding to the above functions. For example, a detection module or unit, a display module or unit, a determination module or unit, and a calculation module or unit, etc.

[0544] The embodiment of the present application further provides a system for data packet transmission in a PDU session, which comprises the PSA, the I-UPF, the access network device, the new I-SMF, the SMF, the terminal device and the server provided in the method embodiment.

[0545] The embodiment of the present application further provides a computer readable storage medium for storing computer program codes, the computer program codes comprising instructions for executing any of the methods for data packet transmission in a PDU session provided in the embodiments of the present application. The readable medium can be a read-only memory (ROM) or a random access memory (RAM), and the embodiments of the present application do not make any limitation in this aspect.

[0546] The present application further provides a computer program product comprising instructions which, when executed by a PSA, an I-UPF, an access network device, a new I-SMF, or an SMF, cause the PSA, the I-UPF, the access network device, the new I-SMF, or the SMF to perform corresponding operations in the above-described methods.

[0547] The embodiment of the present application further provides a chip located in a communication device, which comprises a processing unit and a communication unit. The processing unit can be a processor, and the communication unit can be an input / output interface, a pin or a circuit, etc. The processing unit can execute computer instructions to cause the communication device to perform any of the methods for data packet transmission in a PDU session provided in the embodiments of the present application.

[0548] Optionally, the computer instructions are stored in a storage unit.

[0549] Optionally, the storage unit is a storage unit in the chip, such as a register, a cache, etc. The storage unit can also be a storage unit outside the chip in the terminal, such as a ROM or other types of static storage devices that can store static information and instructions, a random RAM, etc. The processor mentioned in any of the above can be a CPU, a microprocessor, an ASIC, or one or more integrated circuits for controlling the program execution of the above-mentioned method for data packet transmission in a PDU session. The processing unit and the storage unit can be decoupled and arranged on different physical devices, and connected through wired or wireless means to realize the respective functions of the processing unit and the storage unit to support the system chip to realize various functions in the above embodiments. Alternatively, the processing unit and the storage unit can be coupled on the same device.

[0550] Among them, the PDU session data packet transmission method, PSA, I-UPF, access network device, new I-SMF, SMF, computer readable storage medium, computer program product or chip provided by the embodiment of the application are used to execute the corresponding method provided above, so the beneficial effects achieved by them can refer to the beneficial effects of the corresponding method provided above, which will not be repeated here.

[0551] It can be understood that the memory in the embodiments of the application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be ROM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically EPROM (EEPROM) or flash memory. The volatile memory can be RAM, which is used as an 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), synch link DRAM (SLDRAM) and direct rambus RAM (DRRAM).

[0552] In the present application, various messages / information / equipment / network elements / systems / devices / actions / operations / processes / concepts and other types of objects may be named. It can be understood that these specific names do not constitute a limitation on the related objects, and the assigned names can be changed according to the scene, context or usage habits, etc. The technical meaning of the technical terms in the present application should be mainly determined from the function and technical effect embodied / executed in the technical scheme.

[0553] In various embodiments of the present application, the terms and / or descriptions of different embodiments are consistent and can be mutually referred to if there is no special description and logical conflict. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0554] Those skilled in the art can clearly understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0555] The method in the embodiments of the present application can be realized by software, hardware, firmware or any combination thereof, in whole or in part. When realized by software, it can be realized 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 programs or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are executed in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable devices. The computer programs or instructions can be stored in a computer-readable storage medium or transmitted by the computer-readable storage medium. The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server integrated with one or more available media.

[0556] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be described here.

[0557] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be realized by other ways. For example, the device embodiments described above are only schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0558] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, i.e. they can be located in one place or distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiments.

[0559] In addition, each function unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit.

[0560] The functions, if implemented in the form of software functional units and sold or used as independent products, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application, essentially or in part, or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, ROM, RAM, magnetic disk, or optical disk, and various other storage media that can store program codes.

[0561] The above is merely specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which shall be covered within the protection 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 data packet transmission in a PDU session, characterized in that, The method includes: The PDU session anchor point (PSA) receives a first indication message sent by the session management function (SMF). The first indication message indicates that the PSA buffers uplink data packets received on the first path, and upon receiving an end flag from the second path, sends a message to the SMF. The message indicates that the PSA has received the end flag, and the end flag indicates that the transmission of uplink data packets on the second path has ended. The uplink data packets on the first path and the uplink data packets on the second path are uplink data packets of the same PDU session. After receiving the end flag, the PSA sends the message to the SMF; The PSA receives second indication information from the SMF, the second indication information being used to instruct the PSA to send buffered uplink data packets; The PSA sends uplink data packets cached on the first path according to the second instruction information; The transmission order of uplink data packets on the first path is as follows: terminal device, access network device, new intermediate user plane function element (I-UPF), and PSA; or, terminal device, access network device, and PSA. The transmission order of uplink data packets on the second path is as follows: terminal device, access network device, source I-UPF, PSA, or terminal device, access network device, PSA.

2. The method according to claim 1, characterized in that, The method further includes: When the PSA receives an uplink data packet from the second path, it sends the uplink data packet from the second path.

3. The method according to claim 1 or 2, characterized in that, The PSA receives the end marker, including: The PSA receives the end flag sent by the access network device.

4. A method for data packet transmission in a PDU session, characterized in that, The method includes: The SMF sends a first indication message to the PSA, which indicates that the PSA buffers the uplink data packets received on the first path, and when it receives an end flag from the second path, it sends a message to the SMF, which indicates that the PSA has received the end flag. The end flag indicates that the transmission of the uplink data packets on the second path has ended, and the uplink data packets on the first path and the uplink data packets 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 a second indication message to the PSA, the second indication message being used to instruct the PSA to send buffered uplink data packets; The transmission order of uplink data packets on the first path is as follows: terminal device, access network device, new intermediate user plane function element (I-UPF), and PSA; or, terminal device, access network device, and PSA. The transmission order of uplink data packets on the second path is as follows: terminal device, access network device, source I-UPF, PSA, or terminal device, access network device, PSA.

5. The method according to claim 4, characterized in that, Before the SMF sends the first indication information to the PSA, the method further includes: The SMF receives first information from the Access and Mobility Management Function (AMF) or the New Intermediate Session Management Function (I-SMF) network element; Based on the first information, the SMF determines to send the first indication information to the PSA; The first information includes: an indication that the access network device has not changed or a third indication, wherein the third indication is used to indicate the sorting of uplink data packets.

6. The method according to claim 4 or 5, characterized in that, The method further includes: The SMF sends a fourth indication message to the AMF or the access network device, the fourth indication message being used to instruct the access network device to send the end flag on the second path.

7. A method for data packet transmission in a PDU session, characterized in that, The method includes: The access network equipment receives the second information sent by the Access and Mobility Management Function (AMF) network element; The access network device sends an end flag on the second path according to the second information. The end flag is used to indicate the end of uplink data packet transmission on the second path. The access network device sends uplink data packets on the first path; The transmission order of uplink data packets on the first path is as follows: terminal device, access network device, new intermediate user plane function element (I-UPF), PSA, or terminal device, access network device, PSA; The transmission order of uplink data packets on the second path is as follows: terminal device, access network device, source I-UPF, PSA, or terminal device, access network device, PSA.

8. The method according to claim 7, characterized in that, The second information includes: The tunnel information of the new I-UPF, the tunnel information of the PSA, the fourth indication information, or the indication information that the access network equipment has not changed; The fourth indication information is used to instruct the access network device to send the end flag on the second path.

9. A method for data packet transmission in a PDU session, characterized in that, The method includes: The access network device receives a fifth indication message from the AMF, which indicates that the access network device should buffer downlink data packets from the first path before receiving an end flag on the second path. According to the fifth indication information, before receiving the end flag on the second path, the access network device buffers downlink data packets from the first path. The downlink data packets on the first path and the downlink data packets on the second path are downlink data packets of the same PDU session. The end flag is used to indicate the end of the transmission of the downlink data packets on the second path. The access network device sends the downlink data packets received on the second path to the terminal device; When the access network device receives the end flag on the second path, it sends the cached downlink data packet to the terminal device. The transmission order of downlink data packets on the first path is as follows: PSA, new I-UPF, access network device, terminal device; and the transmission order of downlink data packets on the second path is as follows: PSA, source I-UPF, access network device, terminal device; or, the transmission order of downlink data packets on the first path is as follows: PSA, new I-UPF, access network device, terminal device; and the transmission order of downlink data packets on the second path is as follows: PSA, access network device, terminal device; or, the transmission order of downlink data packets on the first path is as follows: PSA, access network device, terminal device; and the transmission order of downlink data packets on the second path is as follows: PSA, source I-UPF, access network device, terminal device.

10. The method according to claim 9, characterized in that, The fifth instruction information includes: The access network equipment has not changed.

11. The method according to claim 9 or 10, characterized in that, The access network device receives the end marker on the second path, including: The access network device receives the end flag from the PSA on the second path.

12. A method for data packet transmission in a PDU session, characterized in that, The method includes: The PSA receives a third message from the SMF, which indicates that the PSA sends an end flag on the second path. The PSA sends an end flag on the second path according to the third information. The end flag is used to indicate the end of downlink data packet transmission on the second path. The end flag is used by the access network device to sort the downlink data packets received on the first path and the second path. The transmission order of downlink data packets on the first path is as follows: PSA, new I-UPF, access network device, terminal device; and the transmission order of downlink data packets on the second path is as follows: PSA, source I-UPF, access network device, terminal device; or, the transmission order of downlink data packets on the first path is as follows: PSA, new I-UPF, access network device, terminal device; and the transmission order of downlink data packets on the second path is as follows: PSA, access network device, terminal device; or, the transmission order of downlink data packets on the first path is as follows: PSA, access network device, terminal device; and the transmission order of downlink data packets on the second path is as follows: PSA, source I-UPF, access network device, terminal device. The downlink data packets on the first path and the downlink data packets on the second path belong to the same PDU session.

13. The method according to claim 12, characterized in that, The third information includes: Used to update downlink tunnel information or indication information of the PSA, the indication information indicating that the PSA sends the end flag on the second path.

14. A method for data packet transmission in a PDU session, characterized in that, The method includes: The SMF receives a fourth message from the AMF or the new I-SMF, which indicates that downlink data packets need to be sorted. The SMF sends third information to the PSA based on the fourth information. The third information is used to indicate that the PSA sends an end flag on the second path. The end flag is used to indicate that the downlink data packet transmission on the second path has ended. The end flag is used by the access network device to sort the downlink data packets received on the first path and the second path. The transmission order of downlink data packets on the first path is as follows: PSA, new I-UPF, access network device, terminal device; and the transmission order of downlink data packets on the second path is as follows: PSA, source I-UPF, access network device, terminal device; or, the transmission order of downlink data packets on the first path is as follows: PSA, new I-UPF, access network device, terminal device; and the transmission order of downlink data packets on the second path is as follows: PSA, access network device, terminal device; or, the transmission order of downlink data packets on the first path is as follows: PSA, access network device, terminal device; and the transmission order of downlink data packets on the second path is as follows: PSA, source I-UPF, access network device, terminal device. The downlink data packets on the first path and the downlink data packets on the second path belong to the same PDU session.

15. The method according to claim 14, characterized in that, The fourth information includes: indication information indicating that the access network device has not changed, or indication information used to indicate the sorting of downlink data packets.

16. A communication device, characterized in that, The communication device includes a processor and a memory, the memory being used to store instructions, and the processor being used to read the instructions to execute the method as described in any one of claims 1 to 8 or the method as described in any one of claims 9 to 15.

17. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, the computer program including program instructions that, when executed by a processor, cause the processor to perform the method as described in any one of claims 1 to 8 or the method as described in any one of claims 9 to 15.

18. A chip, characterized in that, include: A processor for retrieving and running a computer program from memory, causing a communication device on which the chip is mounted to perform the method as described in any one of claims 1 to 8 or the method as described in any one of claims 9 to 15.

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