CN111757553B

CN111757553B - Method and equipment for improving redundant packet data session performance

Info

Publication number: CN111757553B
Application number: CN201910261640.0A
Authority: CN
Inventors: 麻晓宁; 汪巍崴; 王弘; 许丽香
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2019-03-28
Filing date: 2019-04-02
Publication date: 2023-12-15
Anticipated expiration: 2039-04-02
Also published as: CN111757553A

Abstract

The application provides an information transmission method, node equipment and a storage medium in a communication system. In the communication system, a first packet data session exists between a user equipment UE and a first node, and a second packet data session exists between the UE and a second node, the method comprising: the first node receives or transmits indication information from or to the second node, the indication information being used for informing whether the packet data session of the other party continues to transmit the redundant data packet; and the first node transmits or receives response information to the indication information to or from the second node, the response information being used for notifying the other party that the indication information transmitted by the other party has been accepted or rejected.

Description

Method and equipment for improving redundant packet data session performance

Technical Field

The present application relates to mobile communication technology, and more particularly, to a method for supporting the establishment of redundant packet data sessions in a 5G communication network, thereby ensuring reliability of important service data transmission.

Background

Fig. 1 is a schematic diagram of a system architecture in a 5G communication system.

Different network elements in the 5G communication system can be classified into different types such as User Equipment (UE), an access node (gNB) for providing a radio connection service to the UE and connecting to a core network, a mobility management function (AMF), a Session Management Function (SMF), and a user plane data forwarding function (UPF) according to the task to be assumed. Which in turn may consist of a central unit (gNB-CU) and distributed units (gNB-DU). One gNB-CU may be connected to multiple gNB-DUs. Wherein the gNB-CU may in turn be composed of a gNB-CU control plane entity node (gNB-CU-CP) and a gNB-CU user plane entity node (gNB-CU-UP). E1 interface is between gNB-CU-CP and gNB-CU-UP, F1-C interface is between gNB-CU-CP and gNB-DU, F1-U interface is between gNB-CU-UP and gNB-DU.

In a specific deployment, the UE may establish a wireless connection with one gNB while establishing a wireless connection with another gNB. The first gNB is called a Master Node (hereinafter MN) and the second gNB is called a Secondary Node (hereinafter SN).

Fig. 2 is a schematic diagram of a UE simultaneously establishing a radio connection with a MN and a SN in a 5G communication system.

In the existing mechanism, packet data loss often occurs in data transmission in a wireless network, so that the packet data loss is unacceptable for services with higher data reliability requirements. A method is therefore proposed for establishing a redundant packet data session in a 5G communication network using a UE simultaneously connected to a MN and a SN. By this method, in addition to the normally established packet data Session (hereinafter referred to as Session 1), a redundant packet data Session (hereinafter referred to as Session 2) is established. Two packet data sessions transmit the same data stream, thus reducing the likelihood of packet data loss.

Disclosure of Invention

Technical problem

When the same packet data is transmitted simultaneously in two sessions, great resource waste is caused, and the performance of the redundant packet data session is obviously reduced. The present invention is directed to improving redundant packet data session performance.

Solution scheme

The application provides a method for transmitting information in a communication system, in which a first packet data session exists between a User Equipment (UE) and a first node, and a second packet data session exists between the UE and a second node, the method comprising: the first node receives or transmits indication information from or to the second node, the indication information being used for informing whether the packet data session of the other party continues to transmit the redundant data packet; and the first node transmits or receives response information to the indication information to or from the second node, the response information being used for notifying the other party that the indication information transmitted by the other party has been accepted or rejected.

The application provides an information interaction method, which comprises at least one of the following steps: the user equipment UE sends a registration request Registration request message to the core network, including information indicating whether the UE supports a redundant packet data session; the UE sends a protocol data unit PDU session establishment request PDU session establishment request message to a mobile management function entity AMF, wherein the message comprises information indicating an associated session; AMF sends signaling NSmf_PDUSation_CreateSMContext_Request of SMF interface to session management function entity SMF, wherein the signaling NSmf_PDUSation_CreateSMContext_Request comprises redundant packet data session notification RSN information and information indicating UPF list selected by associated session; AMF sends signaling Nsmf_PDUSion_UpdateSMContext_Request of SMF interface to SMF, wherein the signaling Nsmf_PDUSion_UpdateSMContext_Request comprises RSN information and information indicating UPF list selected by association session; the SMF sends signaling Namf_communication_N1N2MessageTransferof the AMF interface to the AMF, wherein the signaling Namf_communication_N1N2MessageTransfercomprises information indicating a UPF list selected for the current session; the SMF sends a packet forwarding control protocol PFCP session establishment request PFCP Session Establishment Request signaling of the N4 interface to a user plane data forwarding function entity UPF, including information indicating that the current session is a redundant packet data session; the AMF sends PDU session resource setting request PDU SESSION RESOURCE SETUP REQUEST signaling of next generation application protocol NGAP to the access node, wherein the signaling comprises information indicating associated session information; and the access node sends an auxiliary node adding request S-NODE ADDITION REQUEST of Xn application protocol XnAP to another access node, wherein the auxiliary node adding request S-NODE ADDITION REQUEST comprises RSN information of the second session and information indicating a first session associated with the second session; the central unit control plane entity of the access node sends a bearer context establishment request BEARER CONTEXT SETUP REQUEST of the E1 application protocol E1AP to the central unit user plane entity, including RSN information of the current session; if an association session exists, also including information indicating the association session; if the access node cannot support the establishment of the redundant packet data session, adding a Cause in a Cause (Cause) field in the NG application protocol NGAP to indicate that the access node does not support the function of the redundant packet data session; if the access node cannot support the establishment of the redundant packet data session, adding a Cause to a Cause (Cause) field of the XnAP in the Xn application protocol to indicate that the access node does not support the function of the redundant packet data session; if the user plane entity of the centralized unit of the access node cannot support the establishment of the redundant packet data session, adding a Cause to the Cause (Cause) field in the E1 application protocol E1AP to indicate that the user plane entity of the centralized unit does not support the function of the redundant packet data session; wherein the association session is a session associated with the current session to form a redundant packet data session.

The application provides an information interaction method, which comprises the following steps: the access node sends information indicating whether a redundant packet data session is supported or not, in order to determine whether to establish a redundant packet data session on said access node based on said information.

The application provides an information acquisition method, which comprises the following steps of: for a downlink data packet, the length of a packet data convergence protocol PDCP sequence number SN is 12 bits, and the lower 12 bits of a general packet radio service channel protocol GTP SN of the downlink data packet are taken as PDCP SN to be generated; for the uplink data packet, the length of the PDCP SN is 18 bits, and the lower 16 bits of the PDCP SN of the uplink data packet is used as the GTP SN to be generated.

The present application provides a first node device for performing an information transmission method in a communication system in which a first packet data session exists between a user equipment UE and a first node, and a second packet data session exists between the UE and a second node, the first node device comprising: an indication information module for receiving or transmitting indication information from or to the second node, the indication information being used for informing whether the packet data session of the other party continues to transmit the redundant data packet; and a response information module for transmitting or receiving response information to the indication information to or from the second node, the response information being for notifying the other party that the indication information transmitted has been accepted or rejected.

The application provides an information interaction system, which comprises at least one of the following devices: a user equipment UE, configured to send a registration request Registration request message to a core network, where the registration request Registration request message includes information indicating whether the UE supports a redundant packet data session, and send a protocol data unit PDU session establishment request PDU session establishment request message to a mobility management function entity AMF, where the message includes information indicating an associated session; AMF, which is used to send signaling Nsmf_PDUSion_CreateSMContext_Request of SMF interface to session management function entity SMF, wherein it includes redundant packet data session notification RSN information and information indicating UPF list used by association session, send signaling Nsmf_PDUSion_updateSMContext_Request of SMF interface to SMF, which includes RSN information and information indicating UPF list used by association session, send PDU session resource setting Request PDU SESSION RESOURCE SETUP REQUEST signaling of next generation application protocol NGAP to access node, which includes information indicating association session information; the SMF is used for sending signaling Namf_communication_N1N2MessageTransferof an AMF interface to the AMF, wherein the signaling Namf_communication_N1N2MessageTransfercomprises information indicating a UPF list selected by a current session, and sending a Packet Forwarding Control Protocol (PFCP) session establishment request (PFCP Session Establishment Request) signaling of an N4 interface to a user plane data forwarding function entity (UPF), wherein the signaling includes information indicating that the current session is a redundant packet data session; an access node for sending an auxiliary node addition request S-NODE ADDITION REQUEST of Xn application protocol XnAP to another access node, comprising RSN information of a second session and information indicating a first session associated with the second session, wherein the associated session is a session associated with a current session to form a redundant packet data session; the gNB-CU-CP is configured to send a bearer context establishment request BEARER CONTEXT SETUP REQUEST of the E1 application protocol E1AP to the gNB-CU-UP, where the bearer context establishment request includes RSN information of the current session, and if an associated session exists, information indicating the associated session; adding a Cause in a Cause (Cause) field in NG application protocol NGAP to indicate that the access node does not support the functionality of the redundant packet data session; adding a Cause in a Cause (Cause) field of XnAP in Xn application protocol to indicate that the access node does not support the functionality of redundant packet data session; adding a Cause in a Cause (Cause) field in the E1 application protocol E1AP to indicate that the user plane entity of the centralized unit does not support the functionality of the redundant packet data session; wherein the association session is a session associated with the current session to form a redundant packet data session.

The present application provides an access node device comprising: a transmitting module for transmitting information indicating whether a redundant packet data session is supported or not, so as to determine whether to establish the redundant packet data session on the access node according to the information.

The application provides an access node device, which comprises: a first module, configured to, for a downlink data packet, use a length of a PDCP sequence number SN of a packet data convergence protocol as 12 bits, and use a low 12 bits of a GTP SN of a general packet radio service channel protocol of the downlink data packet as a PDCP SN to be generated; and a second module, configured to, for an uplink data packet, use a length of PDCP SN of 18 bits, and use a lower 16 bits of PDCP SN of the uplink data packet as a GTP SN to be generated.

The application provides a node device, comprising: a memory for storing a computer program; and a processor for executing the computer program to implement the method as described above.

The present application provides a storage medium storing program code executable by a processor to perform a method as described above.

Advantageous effects

The application provides a method and a device for improving the performance of a redundant packet data session in a 5G communication network, by which when one session transmits packet data in two packet data sessions, the other session can not transmit the same packet data any more, thereby greatly improving the resource utilization rate of the redundant packet data session and improving the performance of the redundant packet data session.

More specifically, a method performed by a first node in a communication system in which a first packet data session exists between a user equipment, UE, and the first node and a second packet data session exists between the UE and a second node, the method comprising: the first node sends indication information to the second node, wherein the indication information is used for informing whether the packet data session of the second node continues to send redundant data packets or not; the first node receives response information to the indication information from the second node, wherein the response information is used for notifying the first node that the indication information is accepted or rejected; and the first node sending or receiving auxiliary information to or from the second node; wherein the auxiliary information includes at least one of: session identifier ID, radio access bearer DRB ID, redundant session sequence number RSN, number of uplink and downlink HARQ failures, number of uplink and downlink HARQ retransmissions, uplink and downlink channel quality index, downlink radio signal quality index, uplink radio signal quality index, UE power headroom report, identity of last packet data successfully transmitted in the session, identity of first packet data and identity of last packet data in a group of consecutive packet data successfully transmitted, identity of single packet data successfully transmitted, identity of first packet data next to be continuously transmitted, identity of first packet data and identity of last packet data in a group of consecutive packet data to be continuously transmitted, and identity of single packet data to be transmitted. The transmission of the indication information and the auxiliary information can help to determine the transmission of the data of the node, and the efficiency is improved.

Other aspects, advantages and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

Drawings

Fig. 3 is a flow chart of an embodiment in which the assistance information for downlink data is transmitted by NR user plane protocol information frames in scenario 1.

Fig. 4 is a flow chart of an embodiment in which the side information for downstream data is signaled by an Xn interface in scenario 1.

Fig. 5 is a flow chart of an embodiment in which the assistance information for uplink data is transmitted by an NR user plane protocol information frame in scenario 1.

Fig. 6 is a flow chart of one embodiment of signaling said assistance information for upstream data by an Xn interface in scenario 1.

Fig. 7 is a flow chart of another embodiment of signaling said assistance information for upstream data by an Xn interface in scenario 1.

Fig. 8 is a flow chart of an embodiment in which the indication information and the response information for downlink data are transmitted by an NR user plane protocol information frame in scenario 1.

Fig. 9 is a flow chart of an embodiment in which the indication information and the response information for downlink data are signaled by an Xn interface in scenario 1.

Fig. 10 is a flowchart of an embodiment in which the indication information and the response information for uplink data are transmitted by an NR user plane protocol in scenario 1.

Fig. 11 is a flow chart of one embodiment of signaling by an Xn interface of the indication information and the response information for uplink data in scenario 1.

Fig. 12 is a flow chart of another embodiment of signaling the indication information and the response information for upstream data by an Xn interface in scenario 1.

Fig. 13 is a flow chart of an embodiment in which the assistance information for downlink data is transmitted by NR user plane protocol information frames in scenario 2.

Fig. 14 is a flow chart of an embodiment in which the side information for downstream data is signaled by the E1 interface in scenario 2.

Fig. 15 is a flow chart of an embodiment in which the assistance information for uplink data is transmitted by NR user plane protocol information frames in scenario 2.

Fig. 16 is a flow chart of an embodiment in which the side information for uplink data is forwarded by the gNB-CU-CP and the gNB-CU-UP in scenario 2.

Fig. 17 is a flow chart of an embodiment in which the side information for uplink data is forwarded by the gNB-CU-CP in scenario 2.

Fig. 18 is a flowchart of an embodiment in which the indication information and the response information for downlink data are transmitted by an NR user plane protocol information frame in scenario 2.

Fig. 19 is a flowchart of an embodiment in which the indication information and the response information for downlink data are signaled by the E1 interface in scenario 2.

Fig. 20 is a flowchart of an embodiment in which the indication information and the response information for uplink data are transmitted by an NR user plane protocol information frame in scenario 2.

Fig. 21 is a flow chart of one embodiment in which the indication information and the response information for uplink data are forwarded by the gNB-CU-CP and the gNB-CU-UP in scenario 2.

Fig. 22 is a flow chart of one embodiment of forwarding the indication information and the response information for uplink data by the gNB-CU-CP in scenario 2.

FIG. 23 is a flow chart of an embodiment of setting user plane channels between gNB-CU-UP1 and gNB-CU-UP2 in scenario 1.

Fig. 24 is a flow chart of an embodiment of setting UP user plane channels between gNB-CU-UP3 and gNB-CU-UP4 in scenario 2.

Fig. 25 is a flow chart of an embodiment of setting Session1 and Session2 in scenario 1, where two different SMFs and different UPFs are included.

Fig. 26 is a flow chart of an embodiment in which the side information or the indication information or the response information for the downlink data in scenario 1 is transmitted by the Xn interface signaling and the E1 interface signaling.

Fig. 27 is a flowchart of an embodiment in which auxiliary information or indication information or response information for uplink data is transmitted by Xn interface signaling and F1 interface signaling in scenario 1.

Fig. 28 is a flow chart of an embodiment in which response information indicating that information is rejected for downlink data in scenario 1 is transmitted by Xn interface signaling and E1 interface signaling.

Fig. 29 is a flowchart of an embodiment in which response information indicating that information is rejected for uplink data in scenario 1 is transmitted by Xn interface signaling and F1 interface signaling.

Fig. 30 is a flowchart of an embodiment in which the session entity 1 receives the indication information from the session entity 2 before receiving the corresponding response information after sending the indication information to the session entity 2.

Fig. 31 is a flow chart of an embodiment of a failure to set up a redundant packet data Session 1.

Fig. 32 is a flow chart of an embodiment of setting a PDCP SN for downstream data and a GTP SN for upstream data in a redundant packet data session.

Fig. 33 is a block diagram of a node apparatus that performs the information transmission method of the present application.

Fig. 34 is a flow chart of an embodiment of setting up a redundant packet data session at an access node.

Detailed Description

The present application provides a method for improving the performance of redundant packet data sessions in a 5G communication network. In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail below by referring to the accompanying drawings and examples.

The application provides an information transmission method in a communication system, in which a first packet data session exists between a UE and a first node, and a second packet data session exists between the UE and a second node, the method comprising: the first node receives or transmits indication information from or to the second node, the indication information being used for informing whether the packet data session of the other party continues to transmit the redundant data packet; and the first node transmits or receives response information to the indication information to or from the second node, the response information being used for notifying the other party that the transmitted indication information has been accepted or rejected.

The node may be, for example, a gNB, which is described below as an example of a node. Those skilled in the art will appreciate that the nodes also include other nodes such as gNB-CU-CP, gNB-CU-UP, gNB-DU, and the like, and are not limited in this regard.

According to one embodiment, the method may further comprise: the first gNB transmits or receives the assistance information to or from the second gNB.

Session2 is built on a different gNB than Session1 (hereinafter referred to as scenario 1, referred to as gNB1 for transmitting Session1, referred to as gNB2 for transmitting Session2, referred to as gNB-CU-UP for gNB1, referred to as gNB-CU-UP for gNB2, referred to as gNB-CU-UP2, referred to as gNB-DU for gNB1 as gNB-DU1, referred to as gNB-DU for gNB2 as gNB-DU 2)

1.1 side information. The auxiliary information includes at least one of: session Identifier (ID) (hereinafter referred to as Session ID), radio access bearer (DRB) ID, redundant Session number (Redundant Sequence Number, hereinafter referred to as RSN), number of uplink and downlink HARQ failures, number of uplink and downlink HARQ retransmissions, uplink and downlink channel quality index, downlink radio signal quality index, uplink radio signal quality index, UE power headroom report, identity of last packet data successfully transmitted by the Session, identity of first packet data and last packet data in a group of consecutive packet data successfully transmitted, identity of single packet data successfully transmitted, identity of first packet data and last packet data in a group of consecutive packet data to be consecutively transmitted next, and identity of single packet data to be transmitted. The identity is a Packet Data Convergence Protocol (PDCP) sequence number (PDCP SN), and/or a general packet radio service channel protocol (GTP) sequence number (GTP SN).

The assistance information may be transmitted by an information frame of a new wireless (NR) user plane protocol. The assistance information in the existing mechanism may be transmitted by ASSISTANCE INFORMATION DATA information frames (hereafter AID) or DL DATA DELIVERY STATUS information frames (hereafter DDDS) or DL USER DATA (hereafter DUD) in the NR USER plane protocol. However, existing mechanisms provide that AID or DDDS can only be issued from SN to MN, and DUD can only be issued from MN to SN. According to the application, when the assistance information is transmitted by the NR user plane protocol information frame and used for a redundant packet data session, it may be: when sent from the MN to the SN, the DUD transmission is used, and when sent from the SN to the MN, the DDDS or AID transmission is used; it may also be: the NR user plane protocol information frames are bi-directional, i.e. can be sent from the MN to the SN or vice versa. In addition, the AID may add fields to transmit Session ID, DRB ID, number of uplink HARQ failures, number of uplink HARQ retransmissions, and uplink channel quality index. The DDDS may add fields to convey the identity of the first packet and the last packet in a set of consecutive packet data that the session was successful in transmitting, as well as the identity of the single packet that was successful in transmitting; and/or, the identification of the next first packet data to be continuously transmitted, the identification of the first packet data and the identification of the last packet data in a group of continuous packet data to be continuously transmitted, and the identification of the single packet data to be transmitted. The DUD may add a field to convey the entire content of the auxiliary information. The auxiliary information may also be transmitted by an additional NR user plane protocol information frame REDUNDANT TRANSMISSION INFORMATION NOTIFICATION (RTIN) that includes the entire content of the auxiliary information.

The side information may also be signaled by the Xn interface, for example by adding a field Redundant transmission assisted information to the existing Xn interface signaling, where Redundant transmission assisted information includes the side information. The Xn interface signaling may be S-NODE MODIFICATION REQUEST, S-NODE MODIFICATION REQUEST ACKNOWLEDGE, S-NODE MODIFICATION REQUIRED, S-NODE MODIFICATION CONFIRM. The side information may also be conveyed by an additional Xn interface signaling REDUNDANT TRANSMISSION INFORMATION NOTIFICATION (which may include field Redundant transmission assisted information).

When the auxiliary information is transmitted by Xn interface signaling, the auxiliary information can be forwarded by E1 interface signaling or F1 interface signaling.

When the auxiliary information is transmitted using E1 interface signaling, a field Redundant transmission assisted information may be added to the existing E1 interface signaling to transmit, where Redundant transmission assisted information includes the auxiliary information. The E1 interface signaling may be BEARER CONTEXT MODIFICATION REQUEST, BEARER CONTEXT MODIFICATION RESPONSE, BEARER CONTEXT MODIFICATION REQUIRED, BEARER CONTEXT MODIFICATION CONFIRM. The side information may also be conveyed by an additional E1 interface signaling REDUNDANT TRANSMISSION INFORMATION NOTIFICATION (which may include field Redundant transmission assisted information).

When the auxiliary information is transmitted using F1 interface signaling, a field Redundant transmission assisted information may be added to the existing F1 interface signaling to transmit, where Redundant transmission assisted information includes the auxiliary information. The F1 interface signaling may be UE CONTEXT MODIFICATION REQUEST, UE CONTEXT MODIFICATION RESPONSE, UE CONTEXT MODIFICATION REQUIRED, UE CONTEXT MODIFICATION CONFIRM. The side information may also be conveyed by an additional F1 interface signaling REDUNDANT TRANSMISSION INFORMATION NOTIFICATION (which may include field Redundant transmission assisted information).

1.2 indicates information. The indication information may include, but is not limited to, a notification information for notifying whether another session continues to transmit redundant packet data. The notification information may be a notification to the other session to transmit the redundant packet data, or may be a notification to the other session to stop transmitting the redundant packet data. The indication information includes at least one of: the identification of the last packet data successful in continuous transmission of the session; the identification of the first packet data and the identification of the last packet data in a group of continuous packet data which is successfully transmitted; identification of the single packet data that was successfully sent; the identification of the next first packet data to be continuously transmitted, the identification of the first packet data and the identification of the last packet data in a group of continuous packet data to be continuously transmitted, and the identification of single packet data to be transmitted; the redundant packet data transmission state of the session, wherein the transmission state refers to transmission or non-transmission; a Session ID; DRB ID; RSN. The identity is a PDCP SN and/or a GTP SN.

The indication information may be transmitted by an information frame of the NR user plane protocol. The indication message may be transmitted by adding a field Redundant transmission Indication to the existing NR user plane protocol information frame, where Redundant transmission Indication includes the indication message. The NR user plane protocol information frame may be DDDS, DUD, AID. However, existing mechanisms provide that the NR user plane protocol information frames can only be unidirectional, i.e. can only be sent from MN to SN, or can only be sent from SN to MN, and the DUD can only be sent from MN to SN. According to the application, when the assistance information is transmitted by the NR user plane protocol information frame and used for a redundant packet data session, it may be: when sent from the MN to the SN, the DUD transmission is used, and when sent from the SN to the MN, the DDDS or AID transmission is used; it may also be: the NR user plane protocol information frames are bi-directional, i.e. can be sent from the MN to the SN or vice versa. In addition, the AID, DDDS, and DUD may add fields to convey the entire contents of the indication information. The indication information may also be transmitted by adding an NR user plane protocol information frame REDUNDANT TRANSMISSION INFORMATION NOTIFICATION (which may include field Redundant transmission Indication).

The indication information may also be signaled by the Xn interface, for example by adding a field Redundant transmission Indication to the existing Xn interface signaling, where Redundant transmission Indication includes the indication information. The Xn interface signaling may be S-NODE MODIFICATION REQUEST, S-NODE MODIFICATION REQUIRED. The indication information may also be transmitted by an additional Xn interface signaling REDUNDANT TRANSMISSION INFORMATION NOTIFICATION (which may include field Redundant transmission Indication).

When the indication information is transmitted by Xn interface signaling, the indication information can be forwarded by E1 interface signaling or F1 interface signaling.

When the indication information is transmitted using E1 interface signaling, a field Redundant transmission Indication may be added to the existing E1 interface signaling to transmit, where Redundant transmission Indication includes the indication information. The E1 interface signaling may be BEARER CONTEXT SETUP REQUEST, BEARER CONTEXT MODIFICATION REQUEST, BEARER CONTEXT MODIFICATION REQUIRED. The indication information may also be transmitted by an E1 interface signaling REDUNDANT TRANSMISSION INFORMATION NOTIFICATION (which may include a field Redundant transmission Indication).

When the indication information is transmitted using the F1 interface signaling, a field Redundant transmission Indication may be added to the existing F1 interface signaling to transmit, where Redundant transmission Indication includes the indication information. The F1 interface signaling may be UE CONTEXT SETUP REQUEST, UE CONTEXT MODIFICATION REQUEST, UE CONTEXT MODIFICATION REQUIRED. The indication information may also be transmitted by an additional F1 interface signaling REDUNDANT TRANSMISSION INFORMATION NOTIFICATION (which may include field Redundant transmission Indication).

1.3 response information to the indication information. The response information may be an initiator notifying the indication information that the receiver has accepted or rejected. The response information may further include at least one of: session ID, DRB ID, RSN.

The response information may be transmitted by an NR user plane protocol information frame. The response message may be transmitted with a field Redundant transmission Indication result added to the existing NR user plane protocol information frame, where Redundant transmission Indication result includes the response information. The NR user plane protocol information frame may be DDDS, DUD, AID. Existing mechanisms provide that the NR user plane protocol information frames can only be unidirectional, i.e. can only be sent from the MN to the SN, or can only be sent from the SN to the MN. According to the application, when the response information is transmitted by the NR user plane protocol information frame and used for a redundant packet data session, it may be: when sent from the MN to the SN, the DUD transmission is used, and when sent from the SN to the MN, the DDDS or AID transmission is used; it may also be: the NR user plane protocol information frames are bi-directional, i.e. can be sent from the MN to the SN or vice versa. In addition, AID, DDDS, and DUD may add fields to convey the entire contents of the response information. The response message may also be transmitted by adding an NR user plane protocol information frame REDUNDANT TRANSMISSION INFORMATION NOTIFICATION (which may include field Redundant transmission Indication result).

The response information may also be signaled by the Xn interface, for example by adding a field Redundant transmission Indication result to the existing Xn interface signaling, where Redundant transmission Indication result includes the response information. The Xn interface signaling may be S-NODE MODIFICATION REQUEST ACKNOWLEDGE, S-NODE MODIFICATION REQUEST REJECT, S-NODE MODIFICATION CONFIRM, S-NODE MODIFICATION REFUSE. The response information may also be conveyed by an additional Xn interface signaling REDUNDANT TRANSMISSION INFORMATION NOTIFICATION (which may include field Redundant transmission Indication result).

When the response information is transmitted by the Xn interface signaling, the response information can be forwarded by the E1 interface signaling or the F1 interface signaling.

When the response information is transmitted using E1 interface signaling, a field Redundant transmission Indication result may be added to the existing E1 interface signaling to transmit, where Redundant transmission Indication result includes the response information. The E1 interface signaling may be BEARER CONTEXT SETUP RESPONSE, BEARER CONTEXT SETUP FAILURE, BEARER CONTEXT MODIFICATION RESPONSE, BEARER CONTEXT MODIFICATION FAILURE, BEARER CONTEXT MODIFICATION CONFIRM. The response information may also be conveyed by an additional E1 interface signaling REDUNDANT TRANSMISSION INFORMATION NOTIFICATION (which may include field Redundant transmission Indication result).

When the response information is transmitted using F1 interface signaling, a field Redundant transmission Indication result may be added to the existing F1 interface signaling to transmit, where Redundant transmission Indicationresult includes the response information. The F1 interface signaling may be UE CONTEXT SETUP RESPONSE, UE CONTEXT SETUP FAILURE, UE CONTEXT MODIFICATION RESPONSE, UE CONTEXT MODIFICATION FAILURE, UE CONTEXT MODIFICATION CONFIRM. The response information may also be conveyed by an additional F1 interface signaling REDUNDANT TRANSMISSION INFORMATION NOTIFICATION (which may include field Redundant transmission Indication result).

In summary, at least one of the auxiliary information, the indication information and the response information is signaled by at least one of: xn interface signaling, E1 interface signaling, F1 interface signaling.

According to an embodiment, wherein the Xn interface signaling is new Xn interface signaling and/or the E1 interface signaling is new E1 interface signaling and/or the F1 interface signaling is new F1 interface signaling.

After the gNB1 or gNB2 sends the indication information to the opposite side, if the indication information of the opposite side is received before the response message of the opposite side is received, the gNB1 or gNB2 can reject the indication information, wait for a period of time and initiate the indication information to the opposite side again.

An NR user plane channel may be established between gNB1 and gNB2 using Xn interface signaling when the assistance information, and/or the indication information, and/or the response information is transmitted using NR user plane protocol information frames. According to an embodiment, the information representing the NR user plane channel address of the primary node and/or the information representing the NR user plane channel address of the secondary node may be carried in Xn interface signaling. For example, field MN Redundant transmission control TNL Information may be added in Xn interface signaling, field SN Redundant transmission control TNL Information may be added in S-NODE ADDITION REQUEST, field MN Redundant transmission control TNL Information may be added in S-NODE MODIFICATION REQUEST and S-NODE MODIFICATION CONFIRM, and field SN Redundant transmission control TNL Information may be added in S-NODE MODIFICATION REQUEST ACKNOWLEDGE and S-NODE MODIFICATION REQUIRED for modifying the NR user plane path.

When using E1 interface signaling to configure Session1 or Session2, a redundant packet data Session notification (RSN) field, and a newly added field Redundant transmission control TNL Information, may be added in existing E1 interface signaling, where RSN indicates that the packet data Session to be configured is a redundant packet data Session and Redundant transmission control TNL Information indicates the NR user plane channel address on the current gNB-CU-UP. The E1 interface signaling may be BEARER CONTEXT SETUP REQUEST, BEARER CONTEXT SETUP RESPONSE, BEARER CONTEXT MODIFICATION REQUEST, BEARER CONTEXT MODIFICATION RESPONSE.

When using F1 interface signaling to configure a DRB mapped by Session1 or Session2, a field RSN may be newly added to the existing F1 interface signaling, where RSN indicates that the packet data Session to be configured is a redundant packet data Session. The F1 interface signaling may be UE CONTEXT SETUP REQUEST, UE CONTEXT SETUP RESPONSE, UE CONTEXT MODIFICATION REQUEST, UE CONTEXT MODIFICATION RESPONSE.

Session2 is built on the same gNB as Session1, but uses different gNB-DUs and different gNB-CU-UP (hereinafter referred to as scenario 2) (different gNB-CU-UP of the gNB are referred to as gNB-CU-UP3 and gNB-CU-UP4, different gNB-DUs of the gNB are referred to as gNB-DU3 and gNB-DU 4)

2.1 side information: the content of the auxiliary information is referred to 1.1.

The side information may be transmitted by NR user plane protocol information frames as described in 1.1.

The side information may also be signaled by the E1 interface as described in 1.1.

The side information may also be signaled by the F1 interface as described in 1.1.

2.2 indication information: the content of the indication information is referred to 1.2.

The indication information may be transmitted by an NR user plane protocol information frame as described in 1.2.

The indication information may also be signaled by the E1 interface as described in 1.2.

The indication information may also be signaled by the F1 interface as described in 1.2.

2.3 response message to the indication information: the content of the response information is referred to as 1.3.

The response information may be transmitted by NR user plane protocol information frames as described in 1.3.

The response information may also be signaled by the E1 interface as described in 1.3.

The response information may also be signaled by the F1 interface as described in 1.3.

After the gNB-CU-UP3 or the gNB-CU-UP4 sends the indication information to the opposite side, before receiving the response information of the opposite side, if the indication information of the opposite side is received, the gNB-CU-UP3 or the gNB-CU-UP4 can reject the indication information, wait for a period of time and send the indication information to the opposite side again.

When the auxiliary information, and/or the indication information, and/or the response information are transmitted using NR user plane protocol information frames, an NR user plane channel may be established between the gNB-CU-UP3 and the gNB-CU-UP4 using E1 interface signaling. Specifically, a field Redundant transmission control TNL Information and a field RSN may be added to the E1 interface signaling. Redundant transmission control TNL Information denotes the NR user plane channel address on the current gNB-CU-UP. The RSN indicates that the packet data session to be configured is a redundant packet data session. See scenario 1.

When using F1 interface signaling to configure a DRB mapped by Session1 or Session2, a field RSN may be newly added to the existing F1 interface signaling to indicate that the packet data Session to be configured is a redundant packet data Session. See scenario 1.

3. The application provides an improvement of signaling which needs interaction when setting up Session1 and Session 2.

The successful establishment process comprises the following steps: an information interaction method, comprising at least one of the following steps:

the UE sends a registration request (Registration request) message to the core network, wherein a field redundancy capability (redundant capability) may be added to indicate whether the UE supports a redundant packet data session;

the UE sends a Protocol Data Unit (PDU) session establishment request (PDU session establishment request) message to the AMF, wherein a field redundant session information (redundant session information) may be added to indicate session (hereinafter associated session) information associated with the current session to form a redundant packet data session (which may include, but is not limited to, an ID of the associated session);

AMF sends SMF interface signaling Nsmf_PDUSion_CreateSMContext_Request to SMF, wherein, field RSN can be added, and field redundant session UPF list indicates UPF list used by association session;

AMF sends SMF interface signaling Nsmmf_PDUSion_UpdateSMContext_Request to SMF, wherein field redundant session UPF list can be added to indicate UPF list selected by association session;

the SMF sends signaling Namf_communication_N1N2MessageTransferof the AMF interface to the AMF, wherein a field redundant session UPF list can be added to indicate a UPF list selected by the association session;

the SMF sends a Packet Forwarding Control Protocol (PFCP) session setup request (PFCP Session Establishment Request) signaling over the N4 interface to the UPF, wherein the optional field redundant session information indicates that the current session is a redundant packet data session;

the AMF sends PDU session resource setup request (PDU SESSION RESOURCE SETUP REQUEST) signaling of Next Generation Application Protocol (NGAP) to the access node, wherein the optional field redundant session information indicates association session information (which may include, but is not limited to, an ID of the association session);

the access node sends a secondary node addition request (S-NODE ADDITION REQUEST) for an Xn application protocol (XnAP) to another access node, where fields RSN may be added and redundant session information indicate associated session information (which may include, but is not limited to, an ID of the associated session, DRB ID, and Cell ID).

Unsuccessful establishment procedure:

in the existing mechanism, session1 and Session2 are established successively. If Session2 cannot be successfully established, the resources consumed in establishing Session1 may be wasted. The present application provides the following means to solve this problem.

An information interaction method, comprising: the gNB transmits information indicating whether a redundant packet data session is supported or not, so as to determine whether to establish the redundant packet data session on the gNB according to the information.

According to one embodiment, the gNB transmitting information indicating whether a redundant packet data session is supported includes at least one of:

the first gNB sends an XN interface SETUP REQUEST (XN SETUP REQUEST) to the second gNB, where an add field redundant capability may be added to the XN SETUP REQUEST to indicate whether the gNB supports a redundant packet data session. The field Cause in the NGAP protocol may be incremented by a value that does not support redundant sessions (No support for redundant Session);

the second gNB sends an XN interface setup response (XN SETUP RESPONSE) to the first gNB, which XN SETUP RESPONSE can be augmented with a field redundant capability indicating whether the gNB supports redundant packet data sessions. The value No support for redundant Session can be added to the field Cause in the NGAP protocol;

The gNB sends a NG interface SETUP REQUEST (NG SETUP REQUEST) to the core network, where field redundant capability may be added to indicate whether the gNB supports a redundant packet data session. The field 5GMM cause in the NAS protocol may be incremented by a value No support for redundant Session. A field 5GSM cause in the NAS protocol may be added with a value No support for redundant Session;

the gNB sends a broadcast message with one added field redundant capability indicating whether the gNB supports a redundant packet data session;

the method comprises the steps that a second gNB receives a request message which is sent by a first gNB and is used for requesting whether the second gNB supports the information of the redundant packet data session or not, and a response message for the request message is sent to the first gNB, wherein the response message comprises the information of whether the second gNB supports the redundant packet data session or not; and

adding new messages in the XnAP protocol: redundant resource reservation (REDUNDANT RESOURCE RESERVATION) and redundant resource reservation acknowledgement (REDUNDANT RESOURCE RESERVATION ACKNOWLEDGE), redundant resource reservation rejection (REDUNDANT RESOURCE RESERVATION REJECT). REDUNDANT RESOURCE RESERVATION may include resources that gNB1 requires gNB2 to reserve including, but not limited to, PDU session aggregation maximum bit rate (PDU Session Aggregate Maximum Bit Rate), 5QI, allocation and retention priority (Allocation and Retention Priority), downlink maximum stream bit rate (Maximum Flow Bit Rate Downlink), uplink maximum stream bit rate (Maximum Flow Bit Rate Uplink), downlink guaranteed stream bit rate (Guaranteed Flow Bit Rate Downlink), uplink guaranteed stream bit rate (Guaranteed Flow Bit Rate Uplink).

4. The length of the PDCP SN in the existing scheme may be configured to be 12 bits or 18 bits, and the length of the gtp SN is 16 bits. The downlink data packet needs to generate PDCP SN at the gNB, and the uplink data packet needs to generate GTP SN at the gNB. An information acquisition method, at gNB:

for downstream data packets: the length of PDCP SN uses 12 bits, the lower 12 bits of GTP SN of this downstream data packet is taken as the PDCP SN to be generated.

For upstream data packets: the length of PDCP SN uses 18 bits, the lower 16 bits of PDCP SN for this upstream data packet being the GTP SN to be generated.

Fig. 3 is a flow chart of an embodiment in which the assistance information for downlink data is transmitted by NR user plane protocol information frames in scenario 1, comprising the steps of:

step 301: gNB1 as MN and gNB2 as SN. gNB1 decides to set Session2 on gNB 2.

Step 302: gNB1 and gNB2 set UP user plane channels between gNB-CU-UP1 and gNB-CU-UP 2.

See fig. 23 for a specific procedure of steps 301 and 302.

Step 303: the gNB-CU-UP2 can send side information to the gNB-CU-UP1 using NR user plane protocol information frames, if needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The auxiliary information is referred to in the relevant part of the summary.

If there is no master-slave relationship between Session1 and Session2, gNB1 may send the assistance information to gNB2 using NR user plane protocol information frames.

Step 304: the gNB-CU-UP1 sends side information to the gNB-CU-UP2 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The auxiliary information is referred to in the relevant part of the preamble 1.1.

Independent independence between step 303 and step 304.

If a master-slave relationship exists between Session1 and Session2 and Session1 is the master, the auxiliary information can only be sent to gNB1 by gNB2. If there is a master-slave relationship between Session1 and Session2 is the master, the auxiliary information can only be sent to gNB2 by gNB1.

Fig. 4 is a flow chart of an embodiment in scenario 1 in which the assistance information for downstream data is signaled by an Xn interface, comprising the steps of:

steps 401 and 402: gNB1 as MN and gNB2 as SN. gNB-CU-CP1 initiates XnAP to gNB-CU-CP 2: the S node adds request (S-NODE ADDITION REQUEST) signaling. gNB-CU-CP2 returns XnAP to gNB-CU-CP 1: the S node adds request reply (S-NODE ADDITION REQUEST ACKNOWLEDGE) signaling. Wherein the S node is a secondary node.

Step 403: when needed, gNB-CU-UP2 uses E1AP: the bearer context modification requires (BEARER CONTEXT MODIFICATION REQUIRED) to send assistance information to the gNB-CU-CP 2. For said auxiliary information see section 1.1 above.

Step 404: the gNB-CU-CP2 used XnAP: the S node modification requires (S-NODE MODIFICATION REQUIRED) to send side information to gNB-CU-CP 1.

Step 405: gNB-CU-CP1 uses E1AP: the bearer context modification request (BEARER CONTEXT MODIFICATION REQUEST) sends assistance information to the gNB-CU-UP 1.

Step 406: gNB-CU-UP1 sends E1AP to gNB-CU-CP 1: a context modification response is carried (BEARER CONTEXT MODIFICATION RESPONSE). Auxiliary information may be included.

Step 407: gNB-CU-CP1 sends XnAP to gNB-CU-CP 2: the S node modifies the acknowledgement (S-NODE MODIFICATION CONFIRM). Auxiliary information may be included.

Step 408: gNB-CU-CP2 sends E1AP to gNB-CU-UP 2: a context modification acknowledgement is carried (BEARER CONTEXT MODIFICATION CONFIRM). Auxiliary information may be included.

If there is no master-slave relationship between Session1 and Session2, gNB1 may send the assistance information to gNB2 using Xn interface signaling.

Step 409: when needed, gNB-CU-UP1 uses E1AP: BEARER CONTEXT MODIFICATION REQUIRED sends side information to gNB-CU-CP 1. For said auxiliary information see section 1.1 above.

Step 410: the gNB-CU-CP1 used XnAP: the S node modification request (S-NODE MODIFICATION REQUEST) sends assistance information to the gNB-CU-CP 2.

Step 411: gNB-CU-CP2 uses E1AP: BEARER CONTEXT MODIFICATION REQUEST sends side information to gNB-CU-UP 2.

Step 412: gNB-CU-UP2 sends E1AP to gNB-CU-CP 2: BEARER CONTEXT MODIFICATION RESPONSE. Auxiliary information may be included.

Step 413: gNB-CU-CP2 sends XnAP to gNB-CU-CP 1: the S node modifies the request reply (S-NODE MODIFICATION REQUEST ACKNOWLEDGE). Auxiliary information may be included.

Step 414: gNB-CU-CP1 sends E1AP to gNB-CU-UP 1: BEARER CONTEXT MODIFICATION CONFIRM. Auxiliary information may be included.

Independent independence between steps 403-408 and steps 409-414.

Fig. 5 is a flow chart of an embodiment in which the assistance information for uplink data is transmitted by an NR user plane protocol information frame in scenario 1, comprising the steps of:

Step 501: gNB1 as MN and gNB2 as SN. gNB1 decides to set Session2 on gNB 2.

Step 502: gNB1 and gNB2 set UP user plane channels between gNB-CU-UP1 and gNB-CU-UP 2.

The specific procedure of step 501 and step 502 is shown in fig. 23.

Step 503: the gNB-DU2 transmits the assistance information to the gNB-CU-UP2 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. For said auxiliary information see section 1.1 above.

Step 504: the gNB-CU-UP2 sends the assistance information to the gNB-CU-UP1 using NR user plane protocol information frames.

Step 505: the gNB-CU-UP1 transmits the auxiliary information to the gNB-DU1 using the NR user plane protocol information frame.

Step 506: the gNB-DU1 transmits the auxiliary information to the gNB-CU-UP1 using the NR user plane protocol information frame when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. For said auxiliary information see section 1.1 above.

Step 507: the gNB-CU-UP1 sends the assistance information to the gNB-CU-UP2 using NR user plane protocol information frames.

Step 508: the gNB-CU-UP2 sends the assistance information to the gNB-DU2 using NR user plane protocol information frames.

Independent independence between steps 503-505 and steps 506-508.

Fig. 6 is a flow chart of one embodiment of signaling by an Xn interface of the auxiliary information for uplink data in scenario 1, wherein the auxiliary information is forwarded by the gNB-CU-UP between the gNB-CU-CP and the gNB-DU, fig. 6 comprising the steps of:

steps 601 and 602: gNB1 as MN and gNB2 as SN. gNB-CU-CP1 initiates XnAP to gNB-CU-CP 2: S-NODE ADDITION REQUEST signaling. gNB-CU-CP2 returns XnAP to gNB-CU-CP 1: S-NODE ADDITION REQUEST ACKNOWLEDGE signaling.

gNB-CU-CP1 sets UP the user plane path between gNB-CU-UP1 and gNB-DU 1. gNB-CU-CP2 sets UP the user plane path between gNB-CU-UP2 and gNB-DU 2.

Step 603: the gNB-DU2 transmits the assistance information to the gNB-CU-UP2 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. For said auxiliary information see section 1.1 above.

Step 604: gNB-CU-UP2 uses E1AP: BEARER CONTEXT MODIFICATION REQUIRED sends side information to gNB-CU-CP 2.

Step 605: the gNB-CU-CP2 used XnAP: S-NODE MODIFICATION REQUIRED sends side information to gNB-CU-CP 1.

Step 606: gNB-CU-CP1 uses E1AP: BEARER CONTEXT MODIFICATION REQUEST sends side information to gNB-CU-UP 1.

Step 607: the gNB-CU-UP1 transmits the auxiliary information to the gNB-DU1 using the NR user plane protocol information frame. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN.

Step 608: the gNB-DU1 sends NR user plane protocol information frames to the gNB-CU-UP 1. Auxiliary information may be included. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. For said auxiliary information see section 1.1 above.

Step 609: gNB-CU-UP1 sends E1AP to gNB-CU-CP 1: BEARER CONTEXT MODIFICATION RESPONSE. Auxiliary information may be included.

Step 610: gNB-CU-CP1 sends XnAP to gNB-CU-CP 2: S-NODE MODIFICATION CONFIRM. Auxiliary information may be included.

Step 611: gNB-CU-CP2 sends E1AP to gNB-CU-UP 2: BEARER CONTEXT MODIFICATION CONFIRM. Auxiliary information may be included.

Step 612: gNB-CU-UP2 sends NR user plane protocol information frames to gNB-DU 2. Auxiliary information may be included. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN.

Step 613: the gNB-DU1 transmits the auxiliary information to the gNB-CU-UP1 using the NR user plane protocol information frame when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. For said auxiliary information see section 1.1 above.

Step 614: gNB-CU-UP1 uses E1AP: BEARER CONTEXT MODIFICATION REQUIRED sends side information to gNB-CU-CP 1.

Step 615: the gNB-CU-CP1 used XnAP: S-NODE MODIFICATION REQUEST sends side information to the gNB-CU-CP 2.

Step 616: gNB-CU-CP2 uses E1AP: BEARER CONTEXT MODIFICATION REQUEST sends side information to gNB-CU-UP 2.

Step 617: the gNB-CU-UP2 sends the assistance information to the gNB-DU2 using NR user plane protocol information frames. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN.

Step 618: the gNB-DU2 sends NR user plane protocol information frames to the gNB-CU-UP 2. Auxiliary information may be included. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. For said auxiliary information see section 1.1 above.

Step 619: gNB-CU-UP2 sends E1AP to gNB-CU-CP 2: BEARER CONTEXT MODIFICATION RESPONSE. Auxiliary information may be included.

Step 620: gNB-CU-CP2 sends XnAP to gNB-CU-CP 1: S-NODE MODIFICATION REQUEST ACKNOWLEDGE. Auxiliary information may be included.

Step 621: gNB-CU-CP1 sends E1AP to gNB-CU-UP 1: BEARER CONTEXT MODIFICATION CONFIRM. Auxiliary information may be included.

Step 622: gNB-CU-UP1 sends NR user plane protocol information frames to gNB-DU 1. Auxiliary information may be included. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN.

Independent independence between steps 603-612 and steps 613-622.

Fig. 7 is a flowchart of another embodiment of the transmission of the side information for uplink data by Xn interface signaling in scenario 1, wherein the side information is sent and received between the gNB-CU-CP and the gNB-DU using F1 interface signaling, fig. 7 comprising the steps of:

Steps 701 and 702: gNB1 as MN and gNB2 as SN. gNB-CU-CP1 initiates XnAP to gNB-CU-CP 2: S-NODE ADDITION REQUEST signaling. gNB-CU-CP2 returns XnAP to gNB-CU-CP 1: S-NODE ADDITION REQUEST ACKNOWLEDGE signaling.

Step 703: when needed, gNB-DU2 uses F1AP to UE context modification requirements (UE CONTEXT MODIFICATION REQUIRED) to send assistance information to gNB-CU-CP 2. For said auxiliary information see section 1.1 above.

Step 704: the gNB-CU-CP2 used XnAP: S-NODE MODIFICATION REQUIRED sends side information to gNB-CU-CP 1.

Step 705: gNB-CU-CP1 sends side information to gNB-DU1 using F1AP: UE context modification request (UE CONTEXT MODIFICATION REQUEST).

Step 706: gNB-DU1 sends the F1AP: UE context modification response to gNB-CU-CP1 (UE CONTEXT MODIFICATION RESPONSE). Auxiliary information may be included.

Step 707: gNB-CU-CP1 sends XnAP to gNB-CU-CP 2: S-NODE MODIFICATION CONFIRM. Auxiliary information may be included.

Step 708: gNB-CU-CP2 sends F1AP: UE context modification confirmation to gNB-DU2 (UE CONTEXT MODIFICATION CONFIRM). Auxiliary information may be included.

Step 709: when necessary, gNB-DU1 transmits side information to gNB-CU-CP1 using F1AP UE CONTEXT MODIFICATION REQUIRED. For said auxiliary information see section 1.1 above.

Step 710: the gNB-CU-CP1 used XnAP: S-NODE MODIFICATION REQUEST sends side information to the gNB-CU-CP 2.

Step 711: gNB-CU-CP2 sends side information to gNB-DU2 using F1AP UE CONTEXT MODIFICATION REQUEST.

Step 712: gNB-DU2 sends F1AP: UE CONTEXT MODIFICATION RESPONSE to gNB-CU-CP 2. Auxiliary information may be included.

Step 713: gNB-CU-CP2 sends XnAP to gNB-CU-CP 1: S-NODE MODIFICATION REQUEST ACKNOWLEDGE. Auxiliary information may be included.

Step 714: gNB-CU-CP1 sends F1AP to gNB-DU 1: UE CONTEXT MODIFICATION CONFIRM. Auxiliary information may be included.

Independent independence between steps 703-708 and steps 709-714.

Fig. 8 is a flowchart of an embodiment in which the indication information and the response information for downlink data in scenario 1 are transmitted by an NR user plane protocol information frame, comprising the steps of:

Step 801: gNB1 as MN and gNB2 as SN. gNB1 decides to set Session2 on gNB 2.

Step 802: gNB1 and gNB2 set UP user plane channels between gNB-CU-UP1 and gNB-CU-UP 2.

See fig. 23 for a specific process of step 801 and step 802.

Step 803: the gNB-CU-UP1 sends indication information to the gNB-CU-UP2 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The indication information is described in the relevant section 1.2 above.

Step 804: the gNB-CU-UP2 sends response information to the gNB-CU-UP2 using NR user plane protocol information frames. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The response information is described in the relevant section 1.3 above.

If there is no master-slave relationship between Session1 and Session2, gNB2 may send indication information to gNB1 using NR user plane protocol information frames.

Step 805: the gNB-CU-UP2 can send indication information to the gNB-CU-UP2 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The indication information is described in the relevant section 1.2 above.

Step 806: the gNB-CU-UP1 sends response information to the gNB-CU-UP2 using NR user plane protocol information frames. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The response information is described in the relevant section 1.3 above.

Independent independence between steps 803-804 and steps 805-806.

If a master-slave relationship exists between Session1 and Session2 and Session1 is the master, the indication information can only be sent to gNB2 by gNB1. If a master-slave relationship exists between Session1 and Session2 is the master, the indication information can only be sent to gNB1 by gNB2.

Fig. 9 is a flowchart of an embodiment in which the indication information and the response information for downlink data are signaled by an Xn interface in scenario 1, comprising the steps of:

steps 901 and 902: gNB1 as MN and gNB2 as SN. gNB-CU-CP1 initiates XnAP to gNB-CU-CP 2: S-NODE ADDITION REQUEST signaling. gNB-CU-CP2 returns XnAP to gNB-CU-CP 1: S-NODE ADDITION REQUEST ACKNOWLEDGE signaling.

Step 903: when needed, gNB-CU-UP1 uses E1AP: BEARER CONTEXT MODIFICATION REQUIRED sends indication information to gNB-CU-CP 1. The indication information is described in the relevant section 1.2 above.

Step 904: the gNB-CU-CP1 used XnAP: S-NODE MODIFICATION REQUEST sends indication information to gNB-CU-CP 2.

Step 905: gNB-CU-CP2 uses E1AP: BEARER CONTEXT MODIFICATION REQUEST sends an indication to gNB-CU-UP 2.

Step 906: gNB-CU-UP2 sends E1AP to gNB-CU-CP 2: BEARER CONTEXT MODIFICATION RESPONSE. Response information is included. The response information is described in the relevant section 1.3 above.

Step 907: gNB-CU-CP2 sends XnAP to gNB-CU-CP 1: S-NODE MODIFICATION REQUEST ACKNOWLEDGE. Response information is included.

Step 908: gNB-CU-CP1 sends E1AP to gNB-CU-UP 1: BEARER CONTEXT MODIFICATION CONFIRM. Response information is included.

If there is no master-slave relationship between Session1 and Session2, gNB2 may send indication information to gNB1 using Xn interface signaling.

Step 909: when needed, gNB-CU-UP2 uses E1AP: BEARER CONTEXT MODIFICATION REQUIRED sends indication information to the gNB-CU-CP 2. The indication information is described in the relevant section 1.2 above.

Step 910: the gNB-CU-CP2 used XnAP: S-NODE MODIFICATION REQUIRED sends indication information to gNB-CU-CP 1.

Step 911: gNB-CU-CP1 uses E1AP: BEARER CONTEXT MODIFICATION REQUEST sends an indication to gNB-CU-UP 1.

Step 912: gNB-CU-UP1 sends E1AP to gNB-CU-CP 1: BEARER CONTEXT MODIFICATION RESPONSE. Response information is included. The response information is described in the relevant section 1.3 above.

Step 913: gNB-CU-CP1 sends XnAP to gNB-CU-CP 2: S-NODE MODIFICATION CONFIRM. Response information is included.

Step 914: gNB-CU-CP2 sends E1AP to gNB-CU-UP 2: BEARER CONTEXT MODIFICATION CONFIRM. Response information is included.

Independent independence between steps 903-908 and steps 909-914.

Fig. 10 is a flowchart of an embodiment in which the indication information and the response information for uplink data are transmitted by NR user plane protocol in scenario 1, comprising the steps of:

step 1001: gNB1 as MN and gNB2 as SN. gNB1 decides to set Session2 on gNB2.

Step 1002: gNB1 and gNB2 set UP user plane channels between gNB-CU-UP1 and gNB-CU-UP 2.

See fig. 23 for a specific process of step 1001 and step 1002.

Step 1003: the gNB-DU1 transmits indication information to the gNB-CU-UP1 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The indication information is described in the relevant section 1.2 above.

Step 1004: the gNB-CU-UP1 sends indication information to the gNB-CU-UP2 using NR user plane protocol information frames.

Step 1005: the gNB-CU-UP2 sends indication information to the gNB-DU2 using NR user plane protocol information frames.

Step 1006: the gNB-DU2 transmits response information to the gNB-CU-UP2 using the NR user plane protocol information frame. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The response information is described in the relevant section 1.3 above.

Step 1007: the gNB-CU-UP2 sends response information to the gNB-CU-UP1 using NR user plane protocol information frames.

Step 1008: gNB-CU-UP1 sends response information to gNB-DU1 using NR user plane protocol information frames.

Step 1009: the gNB-DU2 sends indication information to the gNB-CU-UP2 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The indication information is described in the relevant section 1.2 above.

Step 1010: the gNB-CU-UP2 sends indication information to the gNB-CU-UP1 using NR user plane protocol information frames.

Step 1011: the gNB-CU-UP1 sends indication information to the gNB-DU1 using NR user plane protocol information frames.

Step 1012: the gNB-DU1 transmits response information to the gNB-CU-UP1 using the NR user plane protocol information frame. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The response information is described in the relevant section 1.3 above.

Step 1013: the gNB-CU-UP1 sends response information to the gNB-CU-UP2 using NR user plane protocol information frames.

Step 1014: the gNB-CU-UP2 sends response information to the gNB-DU2 using NR user plane protocol information frames.

Independent independence between steps 1003-1008 and steps 1009-1014.

If a master-slave relationship exists between Session1 and Session2 and Session1 is the master, the indication information can only be sent to gNB2 by gNB1. If there is a master-slave relationship between Session1 and Session2 is the master, the auxiliary information can only be sent to gNB1 by gNB2.

Fig. 11 is a flow chart of one embodiment of signaling by an Xn interface of the indication information and the response information for uplink data in scenario 1, where the indication information and the response information are forwarded by the gNB-CU-UP between the gNB-CU-CP and the gNB-DU. Fig. 11 includes the steps of:

Steps 1101 and 1102: gNB1 as MN and gNB2 as SN. gNB-CU-CP1 initiates XnAP to gNB-CU-CP 2: S-NODE ADDITION REQUEST signaling. gNB-CU-CP2 returns XnAP to gNB-CU-CP 1: S-NODE ADDITION REQUEST ACKNOWLEDGE signaling.

Step 1103: the gNB-DU1 transmits indication information to the gNB-CU-UP1 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The indication information is described in the relevant section 1.2 above.

Step 1104: gNB-CU-UP1 uses E1AP: BEARER CONTEXT MODIFICATION REQUIRED sends indication information to gNB-CU-CP 1.

Step 1105: the gNB-CU-CP1 used XnAP: S-NODE MODIFICATION REQUEST sends indication information to gNB-CU-CP 2.

Step 1106: gNB-CU-CP2 uses E1AP: BEARER CONTEXT MODIFICATION REQUEST sends an indication to gNB-CU-UP 2.

Step 1107: the gNB-CU-UP2 sends indication information to the gNB-DU2 using NR user plane protocol information frames. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN.

Step 1108: the gNB-DU2 sends NR user plane protocol information frames to the gNB-CU-UP 2. Response information is included. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The response information is described in the relevant section 1.3 above.

Step 1109: gNB-CU-UP2 sends E1AP to gNB-CU-CP 2: BEARER CONTEXT MODIFICATION RESPONSE. Response information is included.

Step 1110: gNB-CU-CP2 sends XnAP to gNB-CU-CP 1: S-NODE MODIFICATION REQUEST ACKNOWLEDGE. Response information is included.

Step 1111: gNB-CU-CP1 sends E1AP to gNB-CU-UP 1: BEARER CONTEXT MODIFICATION CONFIRM. Response information is included.

Step 1112: gNB-CU-UP1 sends NR user plane protocol information frames to gNB-DU 1. Response information is included. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN.

If there is no master-slave relationship between Session1 and Session2, gNB2 may send the indication information to gNB1 using Xn interface signaling.

Step 1113: the gNB-DU2 sends indication information to the gNB-CU-UP2 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The indication information is described in the relevant section 1.2 above.

Step 1114: gNB-CU-UP2 uses E1AP: BEARER CONTEXT MODIFICATION REQUIRED sends indication information to the gNB-CU-CP 2.

Step 1115: the gNB-CU-CP2 used XnAP: S-NODE MODIFICATION REQUIRED sends indication information to gNB-CU-CP 1.

Step 1116: gNB-CU-CP1 uses E1AP: BEARER CONTEXT MODIFICATION REQUEST sends an indication to gNB-CU-UP 1.

Step 1117: the gNB-CU-UP1 sends indication information to the gNB-DU1 using NR user plane protocol information frames. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN.

Step 1118: the gNB-DU1 sends NR user plane protocol information frames to the gNB-CU-UP 1. Response information is included. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The response information is described in the relevant section 1.3 above.

Step 1119: gNB-CU-UP1 sends E1AP to gNB-CU-CP 1: BEARER CONTEXT MODIFICATION RESPONSE. Response information is included.

Step 1120: gNB-CU-CP1 sends XnAP to gNB-CU-CP 2: S-NODE MODIFICATION CONFIRM. Response information is included.

Step 1121: gNB-CU-CP2 sends E1AP to gNB-CU-UP 2: BEARER CONTEXT MODIFICATION CONFIRM. Response information is included.

Step 1122: gNB-CU-UP2 sends NR user plane protocol information frames to gNB-DU 2. Response information is included. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN.

Independent independence between steps 1103-1112 and steps 1113-1122.

Fig. 12 is a flow chart of another embodiment of signaling by an Xn interface of the indication information and the response information for uplink data in scenario 1, where the indication information and the response information are sent and received between the gNB-CU-CP and the gNB-DU using F1 interface signaling. Fig. 12 includes the following steps:

steps 1201 and 1202: gNB1 as MN and gNB2 as SN. gNB-CU-CP1 initiates XnAP to gNB-CU-CP 2: S-NODE ADDITION REQUEST signaling. gNB-CU-CP2 returns XnAP to gNB-CU-CP 1: S-NODE ADDITION REQUEST ACKNOWLEDGE signaling.

Step 1203: when necessary, gNB-DU1 transmits indication information to gNB-CU-CP1 using F1AP UE CONTEXT MODIFICATION REQUIRED. The indication information is described in the relevant section 1.2 above.

Step 1204: the gNB-CU-CP1 used XnAP: S-NODE MODIFICATION REQUEST sends indication information to gNB-CU-CP 2.

Step 1205: gNB-CU-CP2 sends indication information to gNB-DU2 using F1AP UE CONTEXT MODIFICATION REQUEST.

Step 1206: gNB-DU2 sends F1AP: UE CONTEXT MODIFICATION RESPONSE to gNB-CU-CP 2. Response information is included. The response information is described in the relevant section 1.3 above.

Step 1207: gNB-CU-CP2 sends XnAP to gNB-CU-CP 1: S-NODE MODIFICATION REQUEST ACKNOWLEDGE. Response information is included.

Step 1208: gNB-CU-CP1 sends F1AP to gNB-DU 1: UE CONTEXT MODIFICATION CONFIRM. Response information is included.

Step 1209: when needed, gNB-DU2 sends indication information to gNB-CU-CP2 using F1AP UE CONTEXT MODIFICATION REQUIRED. The indication information is described in the relevant section 1.2 above.

Step 1210: the gNB-CU-CP2 used XnAP: S-NODE MODIFICATION REQUIRED sends indication information to gNB-CU-CP 1.

Step 1211: gNB-CU-CP1 sends indication information to gNB-DU1 using F1AP UE CONTEXT MODIFICATION REQUEST.

Step 1212: gNB-DU1 sends F1AP: UE CONTEXT MODIFICATION RESPONSE to gNB-CU-CP 1. Response information is included. The response information is described in the relevant section 1.3 above.

Step 1213: gNB-CU-CP1 sends XnAP to gNB-CU-CP 2: S-NODE MODIFICATION CONFIRM. Response information is included.

Step 1214: gNB-CU-CP2 sends F1AP to gNB-DU 2: UE CONTEXT MODIFICATION CONFIRM. Response information is included.

Independent independence between steps 1203-1208 and steps 1209-1214.

Fig. 13 is a flowchart of an embodiment in which the assistance information for downlink data is transmitted by an NR user plane protocol information frame in scenario 2, comprising the steps of:

the gNB-CU-CP sets UP the user plane path between gNB-CU-UP3 and gNB-CU-UP 4. See fig. 24 for a specific process.

Step 1301: the gNB-CU-UP4 can send side information to the gNB-CU-UP3 using NR user plane protocol information frames, if needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. For said auxiliary information see section 2.1 above.

If there is no master-slave relationship between Session1 and Session2, gNB-CU-UP3 can send the assistance information to gNB-CU-UP4 using NR user plane protocol information frames.

Step 1302: the gNB-CU-UP3 sends side information to the gNB-CU-UP4 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. For said auxiliary information see section 2.1 above.

Independent independence between steps 1301 and 1302.

If there is a master-slave relationship between Session1 and Session2 and Session1 is the master, the auxiliary information can only be sent to gNB-CU-UP3 by gNB-CU-UP4. If there is a master-slave relationship between Session1 and Session2 is the master, the auxiliary information can only be sent by gNB-CU-UP3 to gNB-CU-UP4.

Fig. 14 is a flowchart of an embodiment in which the auxiliary information for downlink data is signaled by the E1 interface in scenario 2, comprising the steps of:

the gNB-CU-CP sets gNB-CU-UP3 and gNB-CU-UP4, respectively, using the Bearer Context Setup procedure of the E1 interface. Wherein E1AP: the bearer context setting requests (BEARER CONTEXT SETUP REQUEST) each include a field RSN.

Step 1401: when needed, gNB-CU-UP4 uses E1AP: BEARER CONTEXT MODIFICATION REQUIRED the side information is sent to the gNB-CU-CP. For said auxiliary information see section 2.1 above.

Step 1402: gNB-CU-CP uses E1AP: BEARER CONTEXT MODIFICATION REQUEST sends side information to gNB-CU-UP3.

Step 1403: gNB-CU-UP3 sends E1AP to gNB-CU-CP: BEARER CONTEXT MODIFICATION RESPONSE. Auxiliary information may be included.

Step 1404: gNB-CU-CP sends E1AP to gNB-CU-UP 4: BEARER CONTEXT MODIFICATION CONFIRM. Auxiliary information may be included.

If there is no master-slave relationship between Session1 and Session2, gNB-CU-UP3 may send side information to gNB-CU-UP4.

Step 1405: when needed, gNB-CU-UP3 uses E1AP: BEARER CONTEXT MODIFICATION REQUIRED the side information is sent to the gNB-CU-CP. For said auxiliary information see section 2.1 above.

Step 1406: gNB-CU-CP uses E1AP: BEARER CONTEXT MODIFICATION REQUEST sends side information to gNB-CU-UP4.

Step 1407: gNB-CU-UP4 sends E1AP to gNB-CU-CP: BEARER CONTEXT MODIFICATION RESPONSE. Auxiliary information may be included.

Step 1408: gNB-CU-CP sends E1AP to gNB-CU-UP 3: BEARER CONTEXT MODIFICATION CONFIRM. Auxiliary information may be included.

Independent independence between steps 1401-1404 and steps 1405-1408.

Fig. 15 is a flowchart of an embodiment in which the auxiliary information for uplink data is transmitted by an NR user plane protocol information frame in scenario 2, comprising the steps of:

Step 1501: the gNB-DU4 sends the assistance information to the gNB-CU-UP4 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. For said auxiliary information see section 2.1 above.

Step 1502: the gNB-CU-UP4 sends the assistance information to the gNB-CU-UP3 using NR user plane protocol information frames.

Step 1503: the gNB-CU-UP3 transmits the auxiliary information to the gNB-DU3 using the NR user plane protocol information frame.

If there is no master-slave relationship between Session1 and Session2, gNB-DU3 may send assistance information to gNB-DU 4.

Step 1504: the gNB-DU3 transmits the auxiliary information to the gNB-CU-UP3 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. For said auxiliary information see section 2.1 above.

Step 1505: the gNB-CU-UP3 sends the assistance information to the gNB-CU-UP4 using NR user plane protocol information frames.

Step 1506: the gNB-CU-UP4 sends the assistance information to the gNB-DU4 using NR user plane protocol information frames.

Independent uncorrelation between steps 1501-1503 and steps 1504-1506.

If a master-slave relationship exists between the Session1 and the Session2 and the Session1 is the main, the auxiliary information can only be sent to the gNB-DU3 by the gNB-DU4. If a master-slave relationship exists between the Session1 and the Session2 is the main, the auxiliary information can only be sent to the gNB-DU4 by the gNB-DU3.

Fig. 16 is a flowchart of one embodiment in which the side information for uplink data is forwarded by the gNB-CU-CP and the gNB-CU-UP in scenario 2, comprising the steps of:

gNB-CU-CP sets gNB-CU-UP3 and gNB-DU3, and gNB-CU-UP4 and gNB-DU4, respectively, using Bearer Context Setup procedure of E1 interface and UE Context Setup procedure of F1 interface. Wherein E1AP: BEARER CONTEXT SETUP REQUEST and F1AP: the UE context setup request (UE CONTEXT SETUP REQUEST) includes fields RSN.

Step 1601: the gNB-DU4 sends the assistance information to the gNB-CU-UP4 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. For said auxiliary information see section 2.1 above.

Step 1602: gNB-CU-UP4 uses E1AP: BEARER CONTEXT MODIFICATION REQUIRED the side information is sent to the gNB-CU-CP.

Step 1603: gNB-CU-CP uses E1AP: BEARER CONTEXT MODIFICATION REQUEST sends side information to gNB-CU-UP 3.

Step 1604: the gNB-CU-UP3 transmits the auxiliary information to the gNB-DU3 using the NR user plane protocol information frame. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN.

Step 1605: the gNB-DU3 sends NR user plane protocol information frames to the gNB-CU-UP 3. Auxiliary information may be included. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. For said auxiliary information see section 2.1 above.

Step 1606: gNB-CU-UP3 sends E1AP to gNB-CU-CP: BEARER CONTEXT MODIFICATION RESPONSE. Auxiliary information may be included.

Step 1607: gNB-CU-CP sends E1AP to gNB-CU-UP 4: BEARER CONTEXT MODIFICATION CONFIRM. Auxiliary information may be included.

Step 1608: the gNB-CU-UP4 sends NR user plane protocol information frames to the gNB-DU 4. Auxiliary information may be included. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN.

Step 1609: the gNB-DU3 transmits the auxiliary information to the gNB-CU-UP3 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. For said auxiliary information see section 2.1 above.

Step 1610: gNB-CU-UP3 uses E1AP: BEARER CONTEXT MODIFICATION REQUIRED the side information is sent to the gNB-CU-CP.

Step 1611: gNB-CU-CP uses E1AP: BEARER CONTEXT MODIFICATION REQUEST sends side information to gNB-CU-UP 4.

Step 1612: the gNB-CU-UP4 sends the assistance information to the gNB-DU4 using NR user plane protocol information frames. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN.

Step 1613: the gNB-DU4 sends NR user plane protocol information frames to the gNB-CU-UP 4. Auxiliary information may be included. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. For said auxiliary information see section 2.1 above.

Step 1614: gNB-CU-UP4 sends E1AP to gNB-CU-CP: BEARER CONTEXT MODIFICATION RESPONSE. Auxiliary information may be included.

Step 1615: gNB-CU-CP sends E1AP to gNB-CU-UP 3: BEARER CONTEXT MODIFICATION CONFIRM. Auxiliary information may be included.

Step 1616: gNB-CU-UP3 sends NR user plane protocol information frames to gNB-DU3. Auxiliary information may be included. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN.

Independent independence between steps 1601-1608 and steps 1609-1616.

Fig. 17 is a flowchart of one embodiment in which the auxiliary information for uplink data is forwarded by the gNB-CU-CP in scenario 2, comprising the steps of:

gNB-CU-CP sets gNB-DU3 and gNB-DU4, respectively, using the UE Context Setup procedure of the F1 interface. Wherein F1AP: UE CONTEXT SETUP REQUEST each include a field RSN.

Step 1701: the gNB-DU4 transmits side information to the gNB-CU-CP using F1AP: UE CONTEXT MODIFICATION REQUIRED when needed. For said auxiliary information see section 2.1 above.

Step 1702: the gNB-CU-CP transmits the assistance information to gNB-DU3 using F1AP UE CONTEXT MODIFICATION REQUEST.

Step 1703: gNB-DU3 sends F1AP: UE CONTEXT MODIFICATION RESPONSE to gNB-CU-CP. Auxiliary information may be included.

Step 1704: gNB-CU-CP sends F1AP to gNB-DU 4: UE CONTEXT MODIFICATION CONFIRM. Auxiliary information may be included.

If there is no master-slave relationship between Session1 and Session2, gNB-DU3 may send assistance information to gNB-DU4.

Step 1705: the gNB-DU3 transmits the auxiliary information to the gNB-CU-CP using the F1AP: UE CONTEXT MODIFICATION REQUIRED, when necessary. For said auxiliary information see section 2.1 above.

Step 1706: the gNB-CU-CP sends the assistance information to gNB-DU4 using F1AP UE CONTEXT MODIFICATION REQUEST.

Step 1707: gNB-DU4 sends F1AP: UE CONTEXT MODIFICATION RESPONSE to gNB-CU-CP. Auxiliary information may be included.

Step 1708: gNB-CU-CP sends F1AP to gNB-DU 3: UE CONTEXT MODIFICATION CONFIRM. Auxiliary information may be included.

Independent independence between steps 1701-1704 and steps 1705-1708.

Fig. 18 is a flowchart of an embodiment in which the indication information and the response information for downlink data are transmitted by an NR user plane protocol information frame in scenario 2, comprising the steps of:

Step 1801: the gNB-CU-UP3 sends indication information to the gNB-CU-UP4 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The indication information is described in the relevant section 2.2 above.

Step 1802: the gNB-CU-UP4 sends response information to the gNB-CU-UP3 using NR user plane protocol information frames. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The response information is described in the relevant section 2.3 above.

If there is no master-slave relationship between Session1 and Session2, gNB-CU-UP4 may send indication information to gNB-CU-UP 3.

Step 1803: the gNB-CU-UP4 can send indication information to the gNB-CU-UP3 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The indication information is described in the relevant section 2.2 above.

Step 1804: the gNB-CU-UP3 sends response information to the gNB-CU-UP4 using NR user plane protocol information frames. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The response information is described in the relevant section 2.3 above.

Independent independence between steps 1801-1802 and steps 1803-1804.

If the Session1 and the Session2 have a master-slave relationship and the Session1 is dominant, the indication information can only be sent to the gNB-CU-UP4 by the gNB-CU-UP3. If the Session1 and the Session2 have a master-slave relationship and the Session2 is the master, the indication information can only be sent to the gNB-CU-UP3 by the gNB-CU-UP4.

Fig. 19 is a flowchart of an embodiment in which the indication information and the response information for downlink data are signaled by the E1 interface in scenario 2, comprising the steps of:

the gNB-CU-CP sets gNB-CU-UP3 and gNB-CU-UP4, respectively, using the Bearer Context Setup procedure of the E1 interface. Wherein E1AP: BEARER CONTEXT SETUP REQUEST each include a field RSN.

Step 1901: when needed, gNB-CU-UP3 uses E1AP: BEARER CONTEXT MODIFICATION REQUIRED sends indication information to the gNB-CU-CP. The indication information is described in the relevant section 2.2 above.

Step 1902: gNB-CU-CP uses E1AP: BEARER CONTEXT MODIFICATION REQUEST sends an indication to gNB-CU-UP4.

Step 1903: gNB-CU-UP4 sends E1AP to gNB-CU-CP: BEARER CONTEXT MODIFICATION RESPONSE. Response information is included.

Step 1904: gNB-CU-CP sends E1AP to gNB-CU-UP 3: BEARER CONTEXT MODIFICATION CONFIRM. Response information is included.

If there is no master-slave relationship between Session1 and Session2, gNB-CU-UP4 may send indication information to gNB-CU-UP3.

Step 1905: when needed, gNB-CU-UP4 uses E1AP: BEARER CONTEXT MODIFICATION REQUIRED sends indication information to the gNB-CU-CP. The indication information is described in the relevant section 2.2 above.

Step 1906: gNB-CU-CP uses E1AP: BEARER CONTEXT MODIFICATION REQUEST sends an indication to gNB-CU-UP3.

Step 1907: gNB-CU-UP3 sends E1AP to gNB-CU-CP: BEARER CONTEXT MODIFICATION RESPONSE. Response information is included.

Step 1908: gNB-CU-CP sends E1AP to gNB-CU-UP 4: BEARER CONTEXT MODIFICATION CONFIRM. Response information is included.

Independent independence between steps 1901-1904 and steps 1905-1908.

Fig. 20 is a flowchart of an embodiment in which the indication information and the response information for uplink data are transmitted by an NR user plane protocol information frame in scenario 2, comprising the steps of:

Step 2001: the gNB-DU3 transmits indication information to the gNB-CU-UP3 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The indication information is described in 2.2 above.

Step 2002: the gNB-CU-UP3 sends indication information to the gNB-CU-UP4 using NR user plane protocol information frames.

Step 2003: the gNB-CU-UP4 sends indication information to the gNB-DU4 using NR user plane protocol information frames.

Step 2004: the gNB-DU4 sends response information to the gNB-CU-UP4 using NR user plane protocol information frames. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The response information is described in the relevant section 2.3 above.

Step 2005: the gNB-CU-UP4 sends response information to the gNB-CU-UP3 using NR user plane protocol information frames.

Step 2006: the gNB-CU-UP3 transmits response information to the gNB-DU3 using the NR user plane protocol information frame.

If there is no master-slave relationship between Session1 and Session2, gNB-DU4 may send indication information to gNB-DU3.

Step 2007: the gNB-DU4 sends indication information to the gNB-CU-UP4 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The indication information is described in the relevant section 2.2 above.

Step 2008: the gNB-CU-UP4 sends indication information to the gNB-CU-UP3 using NR user plane protocol information frames.

Step 2009: the gNB-CU-UP3 sends indication information to the gNB-DU3 using NR user plane protocol information frames.

Step 2010: the gNB-DU3 transmits response information to the gNB-CU-UP3 using the NR user plane protocol information frame. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The response information is described in the relevant section 2.3 above.

Step 2011: the gNB-CU-UP3 sends response information to the gNB-CU-UP4 using NR user plane protocol information frames.

Step 2012: the gNB-CU-UP4 sends response information to the gNB-DU4 using NR user plane protocol information frames.

Independent independence between steps 2001-2006 and steps 2007-2012.

If a master-slave relationship exists between the Session1 and the Session2 and the Session1 is the main, the indication information can only be sent to the gNB-DU4 by the gNB-DU3. If a master-slave relationship exists between the Session1 and the Session2 is the main, the indication information can only be sent to the gNB-DU3 by the gNB-DU4.

Fig. 21 is a flowchart of one embodiment in which the indication information and the response information for uplink data in scenario 2 are forwarded by the gNB-CU-CP and the gNB-CU-UP, comprising the steps of:

gNB-CU-CP sets gNB-CU-UP3 and gNB-DU3, and gNB-CU-UP4 and gNB-DU4, respectively, using Bearer Context Setup procedure of E1 interface and UE Context Setup procedure of F1 interface. Wherein E1AP: BEARER CONTEXT SETUP REQUEST and F1AP: UE CONTEXT SETUP REQUEST each include a field RSN.

Step 2101: the gNB-DU3 transmits indication information to the gNB-CU-UP3 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The indication information is described in the relevant section 2.2 above.

Step 2102: gNB-CU-UP3 uses E1AP: BEARER CONTEXT MODIFICATION REQUIRED sends indication information to the gNB-CU-CP.

Step 2103: gNB-CU-CP uses E1AP: BEARER CONTEXT MODIFICATION REQUEST sends an indication to gNB-CU-UP 4.

Step 2104: the gNB-CU-UP4 sends indication information to the gNB-DU4 using NR user plane protocol information frames. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN.

Step 2105: the gNB-DU4 sends NR user plane protocol information frames to the gNB-CU-UP 4. Response information is included. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The response information is described in the relevant section 2.3 above.

Step 2106: gNB-CU-UP4 sends E1AP to gNB-CU-CP: BEARER CONTEXT MODIFICATION RESPONSE. Response information is included.

Step 2107: gNB-CU-CP sends E1AP to gNB-CU-UP 3: BEARER CONTEXT MODIFICATION CONFIRM. Response information is included.

Step 2108: gNB-CU-UP3 sends NR user plane protocol information frames to gNB-DU 3. Response information is included. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN.

If there is no master-slave relationship between Session1 and Session2, gNB-DU4 may send indication information to gNB-DU 3.

Step 2109: the gNB-DU4 sends indication information to the gNB-CU-UP4 using NR user plane protocol information frames when needed. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The indication information is described in the relevant section 2.2 above.

Step 2110: gNB-CU-UP4 uses E1AP: BEARER CONTEXT MODIFICATION REQUIRED sends indication information to the gNB-CU-CP.

Step 2111: gNB-CU-CP uses E1AP: BEARER CONTEXT MODIFICATION REQUEST sends an indication to gNB-CU-UP 3.

Step 2112: the gNB-CU-UP3 sends indication information to the gNB-DU3 using NR user plane protocol information frames. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN.

Step 2113: the gNB-DU3 sends NR user plane protocol information frames to the gNB-CU-UP 3. Response information is included. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN. The response information is described in the relevant section 2.3 above.

Step 2114: gNB-CU-UP3 sends E1AP to gNB-CU-CP: BEARER CONTEXT MODIFICATION RESPONSE. Response information is included.

Step 2115: gNB-CU-CP sends E1AP to gNB-CU-UP 4: BEARER CONTEXT MODIFICATION CONFIRM. Response information is included.

Step 2116: the gNB-CU-UP4 sends NR user plane protocol information frames to the gNB-DU4. Response information is included. The NR user plane protocol information frame may be AID, or DDDS, DUD, or RTIN.

Independent independence between steps 2101-2108 and steps 2109-2116.

Fig. 22 is a flowchart of one embodiment in which the indication information and the response information for uplink data in scenario 2 are forwarded by the gNB-CU-CP, comprising the steps of:

Step 2201: when necessary, gNB-DU3 transmits indication information to gNB-CU-CP using F1AP UE CONTEXT MODIFICATION REQUIRED. The indication information is described in the relevant section 2.2 above.

Step 2202: the gNB-CU-CP sends indication information to the gNB-DU4 using F1AP UE CONTEXT MODIFICATION REQUEST.

Step 2203: gNB-DU4 sends F1AP: UE CONTEXT MODIFICATION RESPONSE to gNB-CU-CP. Response information is included. The response information is referred to in the relevant part of the summary.

Step 2204: gNB-CU-CP sends F1AP to gNB-DU 3: UE CONTEXT MODIFICATION CONFIRM. Response information is included.

Step 2205: when needed, gNB-DU4 sends indication information to gNB-CU-CP using F1AP UE CONTEXT MODIFICATION REQUIRED. The indication information is described in the relevant section 2.2 above.

Step 2206: the gNB-CU-CP transmits the indication information to the gNB-DU3 using F1AP UE CONTEXT MODIFICATION REQUEST.

Step 2207: gNB-DU3 sends F1AP: UE CONTEXT MODIFICATION RESPONSE to gNB-CU-CP. Response information is included. The response information is described in the relevant section 2.3 above.

Step 2208: gNB-CU-CP sends F1AP to gNB-DU 4: UE CONTEXT MODIFICATION CONFIRM. Response information is included.

Independent independence between steps 2201-2204 and steps 2205-2208.

Fig. 23 is a flow chart of an embodiment of setting a user plane path between gNB-CU-UP1 and gNB-CU-UP2 in scenario 1, comprising the steps of:

step 2301: gNB1 as MN and gNB2 as SN. gNB1 decides to set Session2 on gNB 2.gNB-CU-CP1 initiates E1AP: BEARER CONTEXT SETUP REQUEST to gNB-CU-UP1, including the field RSN.

Step 2302: the gNB-CU-UP1 returns E1AP BEARER CONTEXT SETUP RESPONSE to the gNB-CU-CP1 including field redundancy transmission control TNL information (Redundant transmission control TNL Information) indicating the user plane channel address of the user plane channel between gNB-CU-UP1 and gNB-CU-UP2 to be created at gNB-CU-UP 1.

Step 2303: gNB-CU-CP1 initiates F1AP to gNB-DU 1: UE CONTEXT SETUP REQUEST, including field RSN.

Step 2304: gNB-DU1 returns to gNB-CU-CP1 to F1AP: UE CONTEXT SETUP RESPONSE.

Step 2305: gNB-CU-CP1 initiates E1AP to gNB-CU-UP 1: BEARER CONTEXT MODIFICATION REQUEST.

Step 2306: gNB-CU-UP1 returns E1AP to gNB-CU-CP 1: BEARER CONTEXT MODIFICATION RESPONSE.

Step 2307: gNB-CU-CP1 initiates XnAP to gNB-CU-CP 2: S-NODE ADDITION REQUEST signaling. The signaling includes a field MN Redundant transmission control TNL Information, and the value of the signaling is the same as the value of a field Redundant transmission control TNL Information of E1AP: BEARER CONTEXT SETUP RESPONSE in step 2302.

Step 2308: gNB-CU-CP2 initiates E1AP BEARER CONTEXT SETUP REQUEST to gNB-CU-UP2, including fields RSN, redundant transmission control TNL Information. Wherein Redundant transmission control TNL Information is taken from the value of XnAP in step 2307: the field MN Redundant transmission control TNL Information of S-NODE ADDITION REQUEST has the same value.

Step 2309: the gNB-CU-UP2 returns E1AP to gNB-CU-CP2, BEARER CONTEXT SETUP RESPONSE, including field Redundant transmission control TNL Information, indicating the user plane channel address of the user plane channel between gNB-CU-UP1 and gNB-CU-UP2 to be created at gNB-CU-UP 2.

Step 2310: gNB-CU-CP2 initiates F1AP to UE CONTEXT SETUP REQUEST to gNB-DU2, including the field RSN.

Step 2311: gNB-DU2 returns to gNB-CU-CP2 to F1AP: UE CONTEXT SETUP RESPONSE.

Step 2312: gNB-CU-CP2 initiates E1AP to gNB-CU-UP 2: BEARER CONTEXT MODIFICATION REQUEST.

Step 2313: gNB-CU-UP2 returns E1AP to gNB-CU-CP 2: BEARER CONTEXT MODIFICATION RESPONSE.

Step 2314: gNB-CU-CP2 returns XnAP to gNB-CU-CP 1: S-NODE ADDITION REQUEST ACKNOWLEDGE signaling. The signaling includes a field SN Redundant transmission control TNL Information, and the value of the signaling is the same as the value of a field Redundant transmission control TNL Information of E1AP: BEARER CONTEXT SETUP RESPONSE in step 2309.

Step 2315: gNB-CU-CP1 initiates E1AP to gNB-CU-UP1 in BEARER CONTEXT MODIFICATION REQUEST, including field Redundant transmission control TNL Information. Wherein Redundant transmission control TNL Information is taken from the list of XnAP in step 2314: the field SN Redundant transmission control TNL Information of S-NODE ADDITION ACKNOWLEDGE has the same value.

Step 2316: gNB-CU-UP1 returns E1AP to gNB-CU-CP 1: BEARER CONTEXT MODIFICATION RESPONSE.

Fig. 24 is a flow chart of an embodiment of setting a user plane path between gNB-CU-UP3 and gNB-CU-UP4 in scenario 2, comprising the steps of:

step 2401: gNB-CU-CP initiates E1AP to gNB-CU-UP3, BEARER CONTEXT SETUP REQUEST, including field RSN.

Step 2402: the gNB-CU-UP3 returns E1AP to the gNB-CU-CP BEARER CONTEXT SETUP RESPONSE, including a field Redundant transmission control TNL Information indicating the user plane channel address of the user plane channel between gNB-CU-UP3 and gNB-CU-UP4 to be created at gNB-CU-UP 3.

Step 2403: gNB-CU-CP initiates F1AP to gNB-DU 3: UE CONTEXT SETUP REQUEST, including field RSN.

Step 2404: gNB-DU3 returns F1AP to gNB-CU-CP: UE CONTEXT SETUP RESPONSE.

Step 2405: gNB-CU-CP initiates E1AP to gNB-CU-UP 3: BEARER CONTEXT MODIFICATION REQUEST.

Step 2406: gNB-CU-UP3 returns E1AP to gNB-CU-CP: BEARER CONTEXT MODIFICATION RESPONSE.

Step 2407: gNB-CU-CP initiates E1AP BEARER CONTEXT SETUP REQUEST to gNB-CU-UP4, including fields RSN, redundant transmission control TNL Information. The Redundant transmission control TNL Information value is the same as the E1AP: BEARER CONTEXT SETUP RESPONSE field Redundant transmission control TNL Information value in step 2402.

Step 2408: the gNB-CU-UP4 returns E1AP to the gNB-CU-CP BEARER CONTEXT SETUP RESPONSE, including a field Redundant transmission control TNL Information indicating the user plane channel address of the user plane channel between gNB-CU-UP3 and gNB-CU-UP4 to be created at gNB-CU-UP 4.

Step 2409: gNB-CU-CP initiates F1AP to gNB-DU 4: UE CONTEXT SETUP REQUEST, including field RSN.

Step 2410: gNB-DU4 returns F1AP to gNB-CU-CP: UE CONTEXT SETUP RESPONSE.

Step 2411: gNB-CU-CP initiates E1AP to gNB-CU-UP 4: BEARER CONTEXT MODIFICATION REQUEST.

Step 2412: gNB-CU-UP4 returns E1AP to gNB-CU-CP: BEARER CONTEXT MODIFICATION RESPONSE.

Step 2413: gNB-CU-CP initiates E1AP to gNB-CU-UP3 in BEARER CONTEXT MODIFICATION REQUEST, including field Redundant transmission control TNL Information. The Redundant transmission control TNL Information value is the same as the E1AP: BEARER CONTEXT SETUP RESPONSE field Redundant transmission control TNL Information value in step 2408.

Step 2414: gNB-CU-UP3 returns E1AP to gNB-CU-CP: BEARER CONTEXT MODIFICATION RESPONSE.

Fig. 25 is a flow chart of an embodiment of setting Session1 and Session2 in scenario 1, where two different SMFs and different UPFs are included. Fig. 25 includes the steps of:

Step 2501: the UE initiates a NAS to AMF PDU Session establishment request (PDU Session establishment request) to request to set Session1, including a field RSN, which may be a value of 1, indicating that this is a redundant packet data Session.

Step 2502: the AMF initiates an NSMF PDU session context creation request (nsmf_pduse_ CreateSMContext Request) to SMF1, including a field RSN.

Step 2503: SMF1 returns an nsmf_pdu session_context creation response (nsmf_pduse_ CreateSMContext Response) to the AMF.

Step 2504: SMF1 initiates a PFCP session setup request (PFCP Session Establishment Request) to UPF1, including a field RSN.

Step 2505: UPF1 returns a PFCP session setup response to SMF1 (PFCP Session Establishment RESPONSE).

Step 2506: SMF1 initiates a NAMF Communication N1N2 messaging (NAMF Communication N1N2message transfer) to the AMF, including a field RSN, and a field redundancy Session UPF list (redundant Session UPF list), representing a list of UPFs selected by Session 1.

Step 2507: the AMF returns a NAMF Communication N1N2 messaging response (NAMF Communication N1N2MessageTransfer Response) to the SMF 1.

Step 2508: the AMF initiates an NGAP to gNB1, a PDU session resource setup request (PDU SESSION RESOURCE SETUP REQUEST) including a field RSN.

Step 2509: the UE is configured.

Step 2510: the gNB1 returns an NGAP: PDU session resource setting response to the AMF (PDU SESSION RESOURCE SETUP Response).

At steps 2511-2514, the AMF informs SMF1 to update the UE context. SMF1 informs UPF1 to update configuration information. Session1 setup is complete.

Step 2515: the UE initiates a NAS to AMF PDU Session establishment request to request a set Session2, including a field RSN, which may be a value of 2, indicating that this is another redundant packet data Session associated with the first redundant packet data Session. Also included is a field redundant Session information indicating Session1 Session information. The session information is referred to in the summary.

Step 2516: the AMF initiates an NSMF PDU Session context creation request (nsmf_pduse_ CreateSMContext Request) to SMF2, including field RSN, and field redundant Session UPF list, representing a list of UPFs selected by Session 1.

Step 2517: SMF2 returns an NSMF PDU session context creation response (nsmf_pduse_ CreateSMContext Response) to the AMF.

Step 2518: SMF2 initiates PFCP Session Establishment Request to UPF2, including field RSN.

Step 2519: UPF2 returns PFCP Session Establishment RESPONSE to SMF 2.

Step 2520: SMF2 initiates Namf_communication_N1N2MessageTransferto AMF, including field RSN, and field redundant Session UPF list, representing a list of UPFs selected by Session 2.

Step 2521: AMF returns Namf_communication_N1N MessageTransfer Response to SMF 2.

Step 2522: AMF initiates Nsmf_PDUSion_ UpdateSMContext Request to SMF1, including a field RSN, which may be 2 in value, and a field redundant Session UPF list, indicating a list of UPFs selected by Session 2.

Step 2523: SMF1 returns nsmf_pduse_ UpdateSMContext Response to AMF.

Step 2524: AMF initiates NGAP to gNB1 in PDU SESSION RESOURCE SETUP REQUEST, including field RSN. Also included is a field redundant Session information indicating Session1 Session information. The session information is described in the relevant section 3 above.

Step 2525: the UE is configured.

Step 2526: gNB1 returns NGAP to AMF PDU SESSION RESOURCE SETUP Response.

Step 2527-2530, the amf informs SMF2 to update UE context. The SMF2 informs the UPF2 of the update configuration information.

Step 2531: gNB1 initiates XnAP: S-NODE ADDITION REQUEST to gNB2, including a field RSN, which may be a value of 2. Also included is a field redundant Session information indicating Session1 Session information. The session information is described in the relevant section 3 above.

Step 2532: gNB2 initiates XnAP:S-NODE ADDITION REQUEST ACKNOWLEDGE to gNB 1.

Fig. 26 is a flowchart of an embodiment in which auxiliary information or indication information or response information for downlink data is transmitted by Xn interface signaling and E1 interface signaling in scenario 1, where the Xn interface signaling and E1 interface signaling used are newly added signaling. Fig. 26 includes the steps of:

step 2601: when needed, gNB-CU-UP2 uses E1AP: the redundant transmission information notification (REDUNDANT TRANSMISSION INFORMATION NOTIFICATION) sends information to the gNB-CU-CP 2. The information may be auxiliary information. When the gNB-CU-UP2 sends indication information to the gNB-CU-UP1, the information can also be the indication information and/or auxiliary information. When the gNB-CU-UP2 sends response information to the gNB-CU-UP1, the information can also be response information and/or auxiliary information. The auxiliary information and the indication information and the response information are described in the relevant section 1 above.

Step 2602: the gNB-CU-CP2 used XnAP: REDUNDANT TRANSMISSION INFORMATION NOTIFICATION forwards the information to the gNB-CU-CP 1.

Step 2603: gNB-CU-CP1 uses E1AP: REDUNDANT TRANSMISSION INFORMATION NOTIFICATION forwards the information to gNB-CU-UP 1.

Step 2604: when needed, gNB-CU-UP1 uses E1AP: REDUNDANT TRANSMISSION INFORMATION NOTIFICATION information is sent to gNB-CU-CP 1. The information may be auxiliary information. When the gNB-CU-UP1 sends indication information to the gNB-CU-UP2, the information can also be the indication information and/or auxiliary information. When the gNB-CU-UP1 sends response information to the gNB-CU-UP2, the information can also be response information and/or auxiliary information. The auxiliary information and the indication information and the response information are described in the relevant section 1 above.

Step 2605: the gNB-CU-CP1 used XnAP: REDUNDANT TRANSMISSION INFORMATION NOTIFICATION forwards the information to the gNB-CU-CP 2.

Step 2606: gNB-CU-CP2 uses E1AP: REDUNDANT TRANSMISSION INFORMATION NOTIFICATION forwards the information to gNB-CU-UP 2.

If a master-slave relationship exists between the Session1 and the Session2 and the Session1 is dominant, the indication information can only be sent to the gNB2 by the gNB1, and the auxiliary information and/or the response information can only be sent to the gNB1 from the gNB2. If a master-slave relationship exists between the Session1 and the Session2 is the master, the indication information can only be sent to the gNB1 by the gNB2, and the auxiliary information and/or the response information can only be sent to the gNB2 from the gNB1.

Fig. 27 is a flowchart of an embodiment in which auxiliary information or indication information or response information for uplink data is transmitted by Xn interface signaling and F1 interface signaling in scenario 1, where the Xn interface signaling and F1 interface signaling used are newly added signaling. Fig. 27 includes the steps of:

step 2701: when needed, gNB-DU2 uses F1AP: REDUNDANT TRANSMISSION INFORMATION NOTIFICATION information is sent to gNB-CU-CP 2. The information may be auxiliary information. When the gNB-DU2 transmits the indication information to the gNB-DU1, the information may also be the indication information and/or the auxiliary information. When the gNB-DU2 transmits response information to the gNB-DU1, the information may also be response information and/or auxiliary information. The auxiliary information and the indication information and the response information are described in the relevant section 1.1-1.3 above.

Step 2702: the gNB-CU-CP2 used XnAP: REDUNDANT TRANSMISSION INFORMATION NOTIFICATION forwards the information to the gNB-CU-CP 1.

Step 2703: gNB-CU-CP1 uses F1AP: REDUNDANT TRANSMISSION INFORMATION NOTIFICATION forwards the information to the gNB-DU 1.

Step 2704: when needed, gNB-DU1 uses F1AP: REDUNDANT TRANSMISSION INFORMATION NOTIFICATION information is sent to gNB-CU-CP 1. The information may be auxiliary information. When the gNB-DU1 transmits the indication information to the gNB-DU2, the information may also be the indication information and/or the auxiliary information. When the gNB-DU1 transmits response information to the gNB-DU2, the information may also be response information and/or auxiliary information. The auxiliary information and the indication information and the response information are described in the relevant section 1.1-1.3 above.

Step 2705: the gNB-CU-CP1 used XnAP: REDUNDANT TRANSMISSION INFORMATION NOTIFICATION forwards the information to the gNB-CU-CP 2.

Step 2706: gNB-CU-CP2 uses F1AP: REDUNDANT TRANSMISSION INFORMATION NOTIFICATION forwards the information to the gNB-DU 2.

Fig. 28 is a flowchart of an embodiment in which response information indicating that information is rejected for downlink data in scenario 1 is transmitted by Xn interface signaling and E1 interface signaling, comprising the steps of:

step 2801: when needed, gNB-CU-UP2 uses E1AP: BEARER CONTEXT MODIFICATION REQUIRED sends indication information to the gNB-CU-CP 2. The indication information is described in the relevant section 1.2 above.

Step 2802: the gNB-CU-CP2 used XnAP: S-NODE MODIFICATION REQUIRED sends indication information to gNB-CU-CP 1.

Step 2803: gNB-CU-CP1 uses E1AP: BEARER CONTEXT MODIFICATION REQUEST sends an indication to gNB-CU-UP 1.

Step 2804: gNB-CU-UP1 sends E1AP to gNB-CU-CP 1: bearer context modification fails (BEARER CONTEXT MODIFICATION FAILURE). Response information is included indicating that the indication information is rejected.

Step 2805: gNB-CU-CP1 sends XnAP to gNB-CU-CP 2: S-NODE MODIFICATION REFUSE. Response information is included.

Step 2806: gNB-CU-CP2 sends E1AP to gNB-CU-UP 2: BEARER CONTEXT MODIFICATION CONFIRM. Response information is included.

Step 2807: when needed, gNB-CU-UP1 uses E1AP: BEARER CONTEXT MODIFICATION REQUIRED sends indication information to gNB-CU-CP 1. The indication information is described in the relevant section 1.2 above.

If there is no master-slave relationship between Session1 and Session2, gNB1 may send indication information to gNB2 using Xn interface signaling.

Step 2808: the gNB-CU-CP1 used XnAP: S-NODE MODIFICATION REQUEST sends indication information to gNB-CU-CP 2.

Step 2809: gNB-CU-CP2 uses E1AP: BEARER CONTEXT MODIFICATION REQUEST sends an indication to gNB-CU-UP 2.

Step 2810: gNB-CU-UP2 sends E1AP to gNB-CU-CP 2: BEARER CONTEXT MODIFICATION FAILURE. Response information is included indicating that the indication information is rejected.

Step 2811: gNB-CU-CP2 sends XnAP to gNB-CU-CP 1: the S node modifies the request rejections (S-NODE MODIFICATION REQUEST REJECT). Response information is included.

Step 2812: gNB-CU-CP1 sends E1AP to gNB-CU-UP 1: BEARER CONTEXT MODIFICATION CONFIRM. Response information is included.

Independent independence between steps 2801-2806 and steps 2807-2812.

Fig. 29 is a flowchart of an embodiment in which response information indicating that information is rejected for uplink data in scenario 1 is transmitted by Xn interface signaling and F1 interface signaling, comprising the steps of:

step 2901: when necessary, gNB-DU1 transmits indication information to gNB-CU-CP1 using F1AP UE CONTEXT MODIFICATION REQUIRED. The indication information is described in the relevant section 1.2 above.

Step 2902: the gNB-CU-CP1 used XnAP: S-NODE MODIFICATION REQUEST sends indication information to gNB-CU-CP 2.

Step 2903: gNB-CU-CP2 sends indication information to gNB-DU2 using F1AP UE CONTEXT MODIFICATION REQUEST.

Step 2904: gNB-DU2 sends F1AP: UE context modification failure to gNB-CU-CP2 (UE CONTEXT MODIFICATION FAILURE). Response information is included indicating that the indication information is rejected.

Step 2905: gNB-CU-CP2 sends XnAP to gNB-CU-CP 1: S-NODE MODIFICATION REQUEST REJECT. Response information is included.

Step 2906: gNB-CU-CP1 sends F1AP to gNB-DU 1: UE CONTEXT MODIFICATION CONFIRM. Response information is included.

Step 2907: when needed, gNB-DU2 sends indication information to gNB-CU-CP2 using F1AP UE CONTEXT MODIFICATION REQUIRED. The indication information is described in the relevant section 1.2 above.

Step 2908: the gNB-CU-CP2 used XnAP: S-NODE MODIFICATION REQUIRED sends indication information to gNB-CU-CP 1.

Step 2909: gNB-CU-CP1 sends indication information to gNB-DU1 using F1AP UE CONTEXT MODIFICATION REQUEST.

Step 2910: gNB-DU1 sends F1AP: UE CONTEXT MODIFICATION FAILURE to gNB-CU-CP 1. Response information is included indicating that the indication information is rejected.

Step 2911: gNB-CU-CP1 sends XnAP to gNB-CU-CP 2: S-NODE MODIFICATION REFUSE. Response information is included.

Step 2912: gNB-CU-CP2 sends F1AP to gNB-DU 2: UE CONTEXT MODIFICATION CONFIRM. Response information is included.

Independent independence between steps 2901-2906 and steps 2907-2912.

Fig. 30 is a flowchart of an embodiment in which session entity 1 sends indication information to session entity 2 and receives the indication information from session entity 2 before receiving corresponding response information, where session entity 1 and session entity 2 may be a gNB-CU-UP or a gNB-DU. Fig. 30 includes the steps of:

step 3001: the session entity 1 sends indication information to the session entity 2.

Step 3002: the session entity 2 sends indication information to the session entity 1.

So that the session entity 1 receives the indication information from the session entity 2 before receiving the response information. The session entity 2 receives the indication information from the session entity 1 before receiving the response information.

Steps 3003 and 3004: the session entity 1 and the session entity 2 reject the received indication information using the response information, respectively.

Session entity 1 and session entity 2 wait for a period of time, respectively, for example: random time.

Step 3005: after the random time of the session entity 1 expires, if no indication information is received from the session entity 2, the session entity 1 sends the indication information to the session entity 2.

Step 3006: after the random time of the session entity 2 expires, if no indication information is received from the session entity 1, the session entity 2 sends the indication information to the session entity 1.

Fig. 31 is a flow chart of an embodiment of a failure to set up a redundant packet data Session1, comprising the steps of:

steps 3101 and 3102: gNB1 initiates the NG Setup procedure to the AMF. Wherein NGAP: included in the NG SETUP REQUEST field redundant capability indicates whether the gNB1 supports a redundant packet data session.

Steps 3103 and 3104: the gNB2 initiates the NG Setup procedure to the AMF. Wherein NGAP: included in the NG interface SETUP REQUEST (NG SETUP REQUEST) is a field redundant capability indicating whether the gNB2 supports redundant packet data sessions.

Steps 3105 and 3106: gNB1 initiates an Xn Setup procedure to gNB 2. Wherein XnAP: included in the XN interface SETUP REQUEST (XN SETUP REQUEST) is a field redundant capability indicating whether the gNB1 supports a redundant packet data session. XnAP: included in the XN interface setup response (XN SETUP RESPONSE) is a field redundant capability indicating whether the gNB2 supports redundant packet data sessions. The process may also be initiated by gNB2 towards gNB 1.

Step 3107: gNB1 and gNB2 add field redundant capability in the broadcast message to indicate whether the current gNB supports redundant packet data sessions

Steps 3101 and 3102, and steps 3105 and 3106, and step 3107 are independent of each other.

Steps 3108 and 3109: the UE initiates a Registration procedure to the AMF using the NAS message. Wherein NAS: included in the registration request (Registration request) is a field redundant capability indicating whether the UE supports a redundant packet data session.

Step 3110: the UE initiates NAS to AMF PDU Session establishment request to request to set Session1, including field RSN, which may be a value of 1, indicating that this is a redundant packet data Session.

Step 3111a: the AMF returns NAS to the UE: PDU session establishment refute (PDU session establishment reject) includes fields RSN, and Cause. Wherein Cause is set to a new value No support for redundant Session. The Session1 establishment fails. Subsequent steps are not performed.

Step 3111b: AMF initiates NGAP to gNB1 in PDU SESSION RESOURCE SETUP REQUEST, including field RSN.

Step 3112: gNB1 initiates newly added XnAP signaling XnAP: REDUNDANT RESOURCE RESERVATION to gNB 2. Including the resources that gNB1 requires gNB2 to reserve. The resources are described in relation to 3.3 above.

Step 3113a: gNB2 returns a newly added XnAP signaling XnAP: REDUNDANT RESOURCE RESERVATION ACKNOWLEDGE to gNB1 indicating that gNB2 has sufficient resources. The subsequent steps are seen in fig. 25.

Step 3113b: gNB2 returns a newly added XnAP signaling XnAP: REDUNDANT RESOURCE RESERVATION REJECT to gNB1 indicating that gNB2 does not have sufficient resources. If gNB2 does not support a redundant packet data session, the signaling includes a field Cause. The field Cause is set to a new value No support for redundant Session.

Step 3114: gNB1 returns NGAP to AMF PDU SESSION RESOURCE SETUP Response. The method comprises the following fields: the PDU session resource is set to a failure list (PDU Session Resource Failed to Setup List). Including field Cause. The field Cause is set to a new value No support for redundant Session.

Fig. 32 is a flow chart of an embodiment of setting PDCP SNs for downlink data and GTP SNs for uplink data in a redundant packet data session, comprising the steps of:

step 3201: the RRC message is used to configure the length of the uplink PDCP SN to be 18 bits, and the length of the downlink PDCP SN to be 12 bits.

Step 3202: the gNB receives the downlink GTP data packet.

Step 3203: the gNB takes the lower 12 bits of the GTP SN of this downlink GTP data packet as the PDCP SN of the downlink PDCP data packet that needs to be generated.

Step 3204: the gNB forwards the generated downlink PDCP data packet to the UE.

Step 3205: the gNB receives the uplink PDCP data packet.

Step 3206: the gNB takes the lower 16 bits of the PDCP SN of this upstream PDCP data packet as the GTP SN of the upstream GTP data packet that needs to be generated.

Step 3207: the gNB forwards the generated uplink GTP data packet to the UPF.

Steps 3202-3204 and steps 3205-3207 are independently uncorrelated.

Fig. 33 is a block diagram of a node apparatus that performs the information transmission method of the present invention.

The node device 3301 comprises a processor 3302 and a memory 3303, the memory 3303 being for storing a computer program, the processor 3302 being for executing the computer program for implementing the method as described above.

Fig. 34 is a flow chart of an embodiment of setting UP a redundant packet data session at an access node, wherein the access node is comprised of a control plane entity of a centralized unit, a user plane entity of the centralized unit, in this embodiment taking a gNB-CU-CP as an example, and a distributed unit, the user plane entity of the centralized unit taking a gNB-CU-UP as an example, comprising the steps of:

step 3401: the AMF initiates an NGAP to gNB-CU-CP PDU SESSION RESOURCE SETUP REQUEST including RSN information and, if an associated session exists, information indicating the associated session.

Step 3402: gNB-CU-CP initiates E1AP signaling E1AP to gNB-CU-UP BEARER CONTEXT SETUP REQUEST. Including RSN information, and if an association session exists, information indicating the association session.

Step 3403: if the bearer context establishment is successful, the gNB-CU-UP returns E1AP signaling E1AP to the gNB-CU-CP BEARER CONTEXT SETUP RESPONSE.

Step 3404: gNB1 returns NGAP to AMF PDU SESSION RESOURCE SETUP Response.

Step 3405: if the bearer context establishment fails, the gNB-CU-UP returns E1AP signaling E1AP to the gNB-CU-CP, BEARER CONTEXT SETUP FAILURE, including the field Cause. The field Cause is set to a new value No support for redundant Session.

Step 3406: gNB1 returns NGAP to AMF PDU SESSION RESOURCE SETUP Response. The method comprises the following fields: the PDU session resource is set to a failure list (PDU Session Resource Failed to Setup List). Including field Cause. The field Cause is set to a new value No support for redundant Session.

The present application provides a first node device for performing an information transmission method in a communication system in which a first packet data session exists between a user equipment UE and a first node, and a second packet data session exists between the UE and a second node, the first node device comprising: an indication information module for receiving or transmitting indication information from or to the second node, the indication information being used for informing whether the packet data session of the other party continues to transmit the redundant data packet; and a response information module for transmitting or receiving response information to the indication information to or from the second node, the response information being for notifying the other party that the indication information transmitted has been accepted or rejected. According to one embodiment, the first node device further comprises: and the auxiliary information module is used for sending or receiving auxiliary information to or from the second node.

According to one embodiment, the auxiliary information comprises at least one of: session identifier ID, radio access bearer DRB ID, redundant session sequence number RSN, number of uplink and downlink HARQ failures, number of uplink and downlink HARQ retransmissions, uplink and downlink channel quality index, downlink radio signal quality index, uplink radio signal quality index, UE power headroom report, identity of last packet data successfully transmitted in the session, identity of first packet data and identity of last packet data in a group of consecutive packet data successfully transmitted, identity of single packet data successfully transmitted, identity of first packet data next to be continuously transmitted, identity of first packet data and identity of last packet data in a group of consecutive packet data to be continuously transmitted, and identity of single packet data to be transmitted.

According to one embodiment, the indication information comprises at least one of: the identification of the last packet data successful in continuous transmission of the session; the identification of the first packet data and the identification of the last packet data in a successful group of continuous packet data; identification of the single packet data that was successfully sent; the identity of the next first packet data to be transmitted in succession; the identification of the first packet data and the identification of the last packet data in a group of continuous packet data which needs to be continuously transmitted; identification of individual packet data to be transmitted; the redundant packet data transmission state of the session, wherein the transmission state refers to transmission or non-transmission; a session identifier ID; a radio access bearer, DRB, ID; redundant session sequence number RSN.

According to an embodiment, the identification is a packet data convergence protocol PDCP sequence number SN and/or a general packet radio service channel protocol GTP SN.

According to one embodiment, the response information further comprises at least one of: session identifier ID, radio access bearer DRB ID, redundant session sequence number RSN.

According to one embodiment, at least one of the assistance information, the indication information and the response information is transmitted by an information frame of a new wireless NR user plane protocol.

According to one embodiment, the information frame is transmitted from the first node to the second node and/or from the second node to the first node.

According to one embodiment, the information frame is a new information frame.

According to one embodiment, at least one of the assistance information, the indication information and the response information is signaled by at least one of: xn interface signaling, E1 interface signaling, F1 interface signaling.

According to an embodiment, the Xn interface signaling is new Xn interface signaling and/or the E1 interface signaling is new E1 interface signaling and/or the F1 interface signaling is new F1 interface signaling.

According to one embodiment, after the first node or the second node sends the indication information to the opposite side, before receiving the response information of the opposite side, if the indication information of the opposite side is received, the first node or the second node refuses the indication information, waits for a period of time, and sends the indication information to the opposite side again.

According to one embodiment, an NR user plane channel is established between the first node and the second node using Xn interface signaling or E1 interface signaling.

According to one embodiment, establishing an NR user plane path between the first node and the second node using Xn interface signaling or E1 interface signaling comprises at least one of: carrying information representing an NR user plane channel address of a main node in Xn interface signaling; carrying information representing an NR user plane channel address of the auxiliary node in Xn interface signaling; carrying a redundant packet data session notification (RSN) in E1 interface signaling for indicating that the packet data session to be configured is a redundant packet data session; and carrying information representing an NR user plane channel address of the first node or the second node in E1 interface signaling.

According to one embodiment, when configuring the DRB mapped by the first packet data session or the second packet data session using F1 interface signaling, the F1 interface signaling includes redundant packet data session notification RSN information.

The application provides an information interaction system, which comprises at least one of the following devices:

a user equipment UE, configured to send a registration request Registration request message to a core network, where the registration request Registration request message includes information indicating whether the UE supports a redundant packet data session, and send a protocol data unit PDU session establishment request PDU session establishment request message to a mobility management function entity AMF, where the message includes information indicating an associated session;

AMF, which is used to send signaling Nsmf_PDUSion_CreateSMContext_Request of SMF interface to session management function entity SMF, wherein it includes redundant packet data session notification RSN information and information indicating UPF list used by association session, send signaling Nsmf_PDUSion_updateSMContext_Request of SMF interface to SMF, which includes RSN information and information indicating UPF list used by association session, send PDU session resource setting Request PDU SESSION RESOURCE SETUP REQUEST signaling of next generation application protocol NGAP to access node, which includes information indicating association session information;

the SMF is used for sending signaling Namf_communication_N1N2MessageTransferof an AMF interface to the AMF, wherein the signaling Namf_communication_N1N2MessageTransfercomprises information indicating a UPF list selected by a current session, and sending a Packet Forwarding Control Protocol (PFCP) session establishment request (PFCP Session Establishment Request) signaling of an N4 interface to a user plane data forwarding function entity (UPF), wherein the signaling includes information indicating that the current session is a redundant packet data session; and

an access node for sending a secondary node addition request S-NODE ADDITION REQUEST of an Xn application protocol XnAP to another access node, comprising RSN information of the second session and information indicating the first session associated with the second session,

Wherein the association session is a session associated with the current session to form a redundant packet data session.

The application provides an access node arrangement comprising a transmitting module for transmitting information indicating whether a redundant packet data session is supported or not, in order to determine whether to establish a redundant packet data session on the access node based on the information.

According to one embodiment, the access node device transmitting information indicating whether a redundant packet data session is supported comprises at least one of: the first access node sending an XN interface establishment REQUEST XN SETUP REQUEST to the second access node, the XN SETUP REQUEST comprising information indicating whether the access node supports a redundant packet data session; the second access node sends an XN interface setup response XN SETUP RESPONSE to the first access node; the XN SETUP RESPONSE includes information indicating whether the access node supports a redundant packet data session; the access node sending an NG interface SETUP REQUEST, NG SETUP REQUEST, to the core network, comprising information indicating whether the access node supports a redundant packet data session; the access node sending a broadcast message comprising information indicating whether the access node supports a redundant packet data session; and the second access node receives a request message sent by the first access node and used for requesting whether the second access node supports the information of the redundant packet data session or not, and sends a response message aiming at the request message to the first access node, wherein the response message comprises the information of whether the second access node supports the redundant packet data session or not.

The application provides an access node, the access node equipment includes: a first module, configured to, for a downlink data packet, use a length of a PDCP sequence number SN of a packet data convergence protocol as 12 bits, and use a low 12 bits of a GTP SN of a general packet radio service channel protocol of the downlink data packet as a PDCP SN to be generated; and a second module, configured to, for an uplink data packet, use a length of PDCP SN of 18 bits, and use a lower 16 bits of PDCP SN of the uplink data packet as a GTP SN to be generated.

The foregoing embodiments of the present application can be implemented as a program executable by a processor and can be implemented on a general-purpose digital computer, which operates the program by using a computer-readable recording medium. Examples of the computer readable recording medium include magnetic storage media (e.g., read Only Memory (ROM), floppy disks, hard disks, etc.), and optical read-out media (e.g., CD-ROMs, digital Versatile Disks (DVDs), etc.).

The foregoing description of the preferred embodiments of the application is not intended to be limiting, but rather to enable any modification, equivalent replacement, improvement or the like to be made within the spirit and principles of the application.

Claims

1. A method performed by a first node in a communication system in which a first packet data session exists between a user equipment, UE, and the first node, and a second packet data session exists between the UE and a second node, the method comprising:

the first node receives indication information from the second node, wherein the indication information is used for informing whether the packet data session of the first node continues to send redundant data packets or not;

the first node sends response information to the indication information to the second node, wherein the response information is used for informing the second node that the indication information sent by the second node is accepted or rejected; and

the first node sends or receives auxiliary information to or from the second node;

wherein the auxiliary information includes at least one of: session identifier ID, radio access bearer DRB ID, redundant session sequence number RSN, number of uplink and downlink HARQ failures, number of uplink and downlink HARQ retransmissions, uplink and downlink channel quality index, downlink radio signal quality index, uplink radio signal quality index, UE power headroom report, identity of last packet data successfully transmitted in the session, identity of first packet data and identity of last packet data in a group of consecutive packet data successfully transmitted, identity of single packet data successfully transmitted, identity of first packet data next to be continuously transmitted, identity of first packet data and identity of last packet data in a group of consecutive packet data to be continuously transmitted, and identity of single packet data to be transmitted.

2. The method of claim 1, wherein the indication information comprises at least one of: the identification of the last packet data successful in continuous transmission of the session; the identification of the first packet data and the identification of the last packet data in a successful group of continuous packet data; identification of the single packet data that was successfully sent; the identity of the next first packet data to be transmitted in succession; the identification of the first packet data and the identification of the last packet data in a group of continuous packet data which needs to be continuously transmitted; identification of individual packet data to be transmitted; the redundant packet data transmission state of the session, wherein the transmission state refers to transmission or non-transmission; a session identifier ID; a radio access bearer, DRB, ID; redundant session sequence number RSN.

3. The method of any of claims 1 and 2, wherein the identification of the packet data comprises: a packet data convergence protocol PDCP sequence number SN, and/or a general packet radio service channel protocol GTP sequence number SN.

4. The method of claim 1, wherein the response information further comprises at least one of: session identifier ID, radio access bearer DRB ID, redundant session sequence number RSN.

5. The method of claim 1, wherein at least one of the assistance information, the indication information, and the response information is transmitted by an information frame of a new wireless NR user plane protocol.

6. The method of claim 5, wherein the information frame is sent from a first node to a second node and/or from the second node to the first node.

7. The method of claim 1, wherein at least one of the assistance information, the indication information, and the response information is signaled by at least one of: xn interface signaling, E1 interface signaling, F1 interface signaling.

8. The method of claim 1, wherein after the first node or the second node transmits the indication information to the counterpart, if the indication information of the counterpart is received before receiving the response information of the counterpart, the first node or the second node transmits the indication information to the counterpart again after a period of time.

9. The method of claim 5, further comprising:

and establishing an NR user plane channel between the first node and the second node by using Xn interface signaling or E1 interface signaling.

10. The method of claim 9, the establishing an NR user plane path between the first node and the second node using Xn interface signaling or E1 interface signaling comprising at least one of:

Carrying information representing an NR user plane channel address of a main node in Xn interface signaling;

carrying information representing an NR user plane channel address of the auxiliary node in Xn interface signaling;

carrying a redundant packet data session notification (RSN) in E1 interface signaling for indicating that the packet data session to be configured is a redundant packet data session; and

information representing the NR user plane channel address of the first node or the second node is carried in E1 interface signaling.

11. The method of claim 1, wherein,

when the DRB mapped by the first packet data session or the second packet data session is configured using F1 interface signaling, the F1 interface signaling includes redundant session sequence number RSN information.

12. A method performed by a first node in a communication system in which a first packet data session exists between a user equipment, UE, and the first node, and a second packet data session exists between the UE and a second node, the method comprising:

the first node sends indication information to the second node, wherein the indication information is used for informing whether the packet data session of the second node continues to send redundant data packets or not;

the first node receives response information to the indication information from the second node, wherein the response information is used for notifying the first node that the indication information sent by the first node is accepted or rejected; and

13. The method of claim 12, wherein the indication information includes at least one of: the identification of the last packet data successful in continuous transmission of the session; the identification of the first packet data and the identification of the last packet data in a successful group of continuous packet data; identification of the single packet data that was successfully sent; the identity of the next first packet data to be transmitted in succession; the identification of the first packet data and the identification of the last packet data in a group of continuous packet data which needs to be continuously transmitted; identification of individual packet data to be transmitted; the redundant packet data transmission state of the session, wherein the transmission state refers to transmission or non-transmission; a session identifier ID; a radio access bearer, DRB, ID; redundant session sequence number RSN.

14. The method of any of claims 12 and 13, wherein the identification of the packet data comprises: a packet data convergence protocol PDCP sequence number SN, and/or a general packet radio service channel protocol GTP sequence number SN.

15. The method of claim 12, wherein the response information further comprises at least one of: session identifier ID, radio access bearer DRB ID, redundant session sequence number RSN.

16. The method of claim 12, wherein at least one of the assistance information, the indication information, and the response information is transmitted by an information frame of a new wireless NR user plane protocol.

17. The method according to claim 16, wherein the information frame is sent from a first node to a second node and/or from the second node to the first node.

18. The method of claim 12, wherein at least one of the assistance information, the indication information, and the response information is signaled by at least one of: xn interface signaling, E1 interface signaling, F1 interface signaling.

19. The method of claim 12, wherein after the first node or the second node transmits the indication information to the counterpart, if the indication information of the counterpart is received before receiving the response information of the counterpart, the first node or the second node transmits the indication information to the counterpart again after a period of time.

20. The method of claim 16, further comprising:

21. The method of claim 20, establishing an NR user plane path between the first node and the second node using Xn interface signaling or E1 interface signaling comprising at least one of:

22. The method of claim 12, wherein,

23. A method performed by an access node in a communication system, comprising:

an access node transmitting information indicating whether a redundant packet data session is supported, the information being used to determine whether to establish a redundant packet data session on the access node; and

The access node receives the auxiliary information;

24. A method performed by an access node in a communication system, comprising:

for downlink data packets, the length of a packet data convergence protocol PDCP sequence number SN is 12 bits, and the low 12 bits of a general packet radio service channel protocol GTP SN of the downlink data packets are used as PDCP SN to be generated;

For the uplink data packet, the length of the PDCP SN is 18 bits, and the lower 16 bits of the PDCP SN of the uplink data packet are used as GTP SNs to be generated; and

the access node receives the auxiliary information;

25. A node device, comprising:

a memory for storing a computer program; and

a processor for executing the computer program for implementing the method according to any of claims 1-22.

26. An access node apparatus, comprising:

a memory for storing a computer program; and

processor for executing said computer program for implementing the method according to claim 23 or 24.

27. A storage medium storing program code executable by a processor to perform the method of any one of claims 1-24.