WO2020164441A1 - 无线通信系统中的切换方法、装置及系统 - Google Patents

无线通信系统中的切换方法、装置及系统 Download PDF

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Publication number
WO2020164441A1
WO2020164441A1 PCT/CN2020/074511 CN2020074511W WO2020164441A1 WO 2020164441 A1 WO2020164441 A1 WO 2020164441A1 CN 2020074511 W CN2020074511 W CN 2020074511W WO 2020164441 A1 WO2020164441 A1 WO 2020164441A1
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WIPO (PCT)
Prior art keywords
base station
data packet
index
source base
target base
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PCT/CN2020/074511
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English (en)
French (fr)
Inventor
严乐
张宏平
曾清海
耿婷婷
胡星星
Original Assignee
华为技术有限公司
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Publication date
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to KR1020217028803A priority Critical patent/KR102598655B1/ko
Priority to EP20755077.3A priority patent/EP3920592B1/en
Publication of WO2020164441A1 publication Critical patent/WO2020164441A1/zh
Priority to US17/401,913 priority patent/US20210377816A1/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/02—Buffering or recovering information during reselection ; Modification of the traffic flow during hand-off
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0055—Transmission or use of information for re-establishing the radio link
    • H04W36/0064—Transmission or use of information for re-establishing the radio link of control information between different access points
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0011—Control or signalling for completing the hand-off for data sessions of end-to-end connection
    • H04W36/0016—Hand-off preparation specially adapted for end-to-end data sessions
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/02—Buffering or recovering information during reselection ; Modification of the traffic flow during hand-off
    • H04W36/026—Multicasting of data during hand-off
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0011—Control or signalling for completing the hand-off for data sessions of end-to-end connection
    • H04W36/0022—Control or signalling for completing the hand-off for data sessions of end-to-end connection for transferring data sessions between adjacent core network technologies
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0055—Transmission or use of information for re-establishing the radio link
    • H04W36/0061—Transmission or use of information for re-establishing the radio link of neighbour cell information
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/06—Reselecting a communication resource in the serving access point
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/10—Connection setup
    • H04W76/12—Setup of transport tunnels
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/08—Reselecting an access point
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/20—Manipulation of established connections
    • H04W76/22—Manipulation of transport tunnels

Definitions

  • This application relates to the field of communication technology, and in particular to a handover method, device and system in a wireless communication system.
  • the network switches the user equipment from the source cell to the target cell for data transmission through the handover process, and the source base station sends the handover command to the user equipment over the air interface After that, it stops transmitting uplink and downlink data to the user equipment. Then, the source base station sends a sequence number status transfer message to the target base station and forwards the data packet to the target base station. For example, for uplink, the source base station sends a sequence number status transfer message to the target base station.
  • the base station forwards the received out-of-order uplink data packets (starting from the first out-of-order UL data packet, and all other data packets after the first out-of-order packet (if any)) to the target base station; for downlink ,
  • the source base station forwards the downlink data packets that have been sent to the user equipment but have not been successfully received by the user equipment, and the new data packets from the core network to the target base station.
  • data transmission that the user equipment cannot complete at the source base station will continue to be completed at the target base station after the user equipment has successfully switched to the target base station.
  • the data packet forwarding between the source base station and the target base station will cause delay, especially when the backhaul between the base stations is not ideal, the delay is relatively large, which reduces the user experience of delay-sensitive services. Therefore, how to reduce the time delay caused by data forwarding is a problem that needs to be solved.
  • This application provides an information transmission method, device and system, which can reduce the time delay of data transmission.
  • the source base station of the user equipment UE receives the first data packet from the core network device; the target base station of the UE receives the second data packet from the core network device, and the second data packet is of the first data packet A copy, the first data packet and the second data packet each include a first index; the source base station sends first indication information to the target base station, and the first indication information indicates the first index and the first index
  • the mapping relationship used by the source base station and the target base station is the same, so that the UE can correctly receive the data packets from the source base station and the target base station, so that the UE can correctly perform repeated packet detection or data packet reordering or ordering. submit.
  • the second data packet and the first data packet include at least the same payload (payload).
  • the method further includes: the core network device sending second indication information to the source base station.
  • the source base station receives the second indication information and determines the mapping relationship between the first index and the second index.
  • the second indication information may be included in the first data packet, or the second indication information may be carried by the core network device in a separate message to notify the source base station.
  • the method further includes: the source base station receives a fifth data packet from the UE, and in response to the fifth data packet, sends a seventh data packet to the core network device. data pack.
  • the target base station receives the sixth data packet from the UE, and in response to the sixth data packet, sends an eighth data packet to the core network device.
  • the sixth data is a copy of the fifth data packet.
  • the fifth data packet and the sixth data packet respectively include a third index.
  • the seventh data packet and the eighth data packet respectively include a fourth index.
  • the fifth data packet and the sixth data packet include at least the same valid payload and use the same index, so that the data packet from the UE is correctly received by the network side to ensure the UE handover process Normal communication in.
  • the source base station sends third indication information to the target base station, where the third indication information indicates a mapping relationship between the third index and the fourth index. Therefore, the target base station and the target base station can use the same index to send data packets for the UE to the core network device, thereby ensuring that the data from the UE is correctly received during the UE handover process.
  • the core network equipment can correctly receive the data from the UE from the source base station and the target base station respectively, thereby facilitating repeated packet detection and data packet repetition by the UE. Sort or submit in order.
  • the UE sends fourth indication information to the source base station.
  • the source base station determines the mapping relationship between the third index and the fourth index according to the indication information.
  • the fourth indication information is included in the fifth data packet, or the UE is carried by other messages.
  • the first indication information includes the value of the first index and the value of the second index corresponding to the first index. In another possible implementation manner, the first indication information includes a mapping formula of the first index and the second index corresponding to the first index. In another possible implementation manner, the first indication information includes a difference between a value of the first index and a value of the second index corresponding to the first index.
  • the target base station of the user equipment UE receives the handover request message from the source base station of the UE.
  • the target base station sends a request message to the first core network device in response to the handover request message to request a copy of the first data packet.
  • the first data packet is a data packet for user equipment UE sent by the second core network device to the source base station.
  • the first core network device and the second core network device are the same core network device or different core network devices.
  • the target base station receives a confirmation message for the request message from the first core network device.
  • the target base station also sends a handover request confirmation message to the source base station.
  • a transmission channel is established between the target base station and the core network equipment, and the duplication process is activated as soon as possible, and then the UE and the source base station Before the quality of the link between them deteriorates, the channel for transmitting the backup data packet between the target base station and the core network device is successfully established, which ensures the reliability of data transmission.
  • the target base station receives a copy of the first data packet from the second core network device.
  • the copy of the first data packet may be sent by the second core network device to the target base station, or forwarded by the first core network device to the target base station.
  • the source base station sends a third data packet to the UE in response to the first data packet. And the copy of the first data packet respectively include a first index.
  • the target base station sends a fourth data packet to the UE in response to the copy of the first data packet.
  • the third data packet and the fourth data packet respectively include a second index.
  • the communication device may be a base station, which serves as a target base station for the UE.
  • the communication device may also be a device in a target base station serving as a UE, such as a communication chip.
  • the communication device includes a sending unit and a receiving unit.
  • the sending unit and the receiving unit respectively implement the sending function and the realization function in the above method.
  • the sending unit may be a transmitter, a transmitter, a sending circuit, an output circuit, an interface of a communication chip, or other means that recognize that the sending function can be realized.
  • the receiving unit may be a receiver of a base station, a receiver, a receiving circuit, an input circuit, an interface of a communication chip, or any other means that can realize a receiving function.
  • the receiving unit is configured to receive a handover request message from the source base station.
  • the sending unit is configured to send a request message to the first core network device in response to the handover request message to request a copy of the first data packet, where the first data packet is the second core network device sending a request to the source base station.
  • the sent data packet for the user equipment UE wherein the first core network device and the second core network device are the same core network device, or are different core network devices.
  • the user equipment UE sends data packets P 1 , P 2 ... P N to the source base station.
  • the UE sends data packets P i to P N to the target base station, where the data packet P i is the first data packet among the data packets P 1 to P N that has not been correctly received by the source base station, and N is an integer greater than or equal to 1, i is an integer greater than or equal to 1 and less than or equal to N.
  • the target base station receives the data packet from the user equipment to the P i that P N, and the core network device to send a packet P i P N.
  • the source base station to the core network apparatus transmits the data packet before the data packet P 1 to P N in the packet P i.
  • the UE can reduce the possibility of packet loss and improve the reliability of data transmission by sending the first incorrectly received data packet and subsequent data packets to the target base station.
  • the indexes of the data packets P 1 to P N are continuous and increasing, or continuously decreasing, or arranged according to a predetermined rule
  • the UE before sending P i to P N to the target base station, the UE receives indication information from the source base station, and the indication information instructs the UE to send a data packet P i to the target base station.
  • the indication information is included in a radio resource control RRC reconfiguration message or other messages.
  • the UE determines the data packet that has not been correctly received by the source base station or the first data packet that has not been correctly received by the source base station .
  • Negative for the data packet P i response for the data packet P i if the UE is not received from the source base station or received from the source base station acknowledgment NACK, and to receive the said data packet acknowledgment ACK 1 to P P before the packet P i N, then the UE determines that the data packet P I is in the data packet. 1 to P N P is not correctly received by the source base station The first packet.
  • the communication device may be user equipment UE, or a communication chip for user equipment.
  • the communication device includes a sending unit to implement the sending function in the above method.
  • the sending unit is used to send data packets P 1 , P 2 ... P N to the source base station, and send data packets P i to P N to the target base station, where the data packet P i is the data packets P 1 to P N
  • N is an integer greater than or equal to 1
  • i is an integer greater than or equal to 1 and less than or equal to N.
  • the sending unit may be a transmitter, a transmitter, a sending circuit, an output circuit, an interface of a communication chip, or other means that recognize that the sending function can be realized.
  • the processing device also includes a processing unit for determining whether the transmitted data packet is received correctly. For example, the processing unit determines the data packet that was not correctly received by the source base station, or the first data packet that was not correctly received by the source base station. If the communication device does not receive the response packet from the source for P i of the base station, or receives a negative for the data packets from the source base station to a P i that acknowledgment NACK, is received and the packet data P to P acknowledgment ACK 1 before the packet P i N, then determining that the data packet for the data packet P I P P N. 1 to the source base station that are not correctly received the first Packets.
  • the communication device is a base station, which can serve as the source base station and/or the target base station of the UE. Or the communication device is a device in the source base station and/or target base station serving as the UE, such as a communication chip.
  • the communication device includes a sending unit and a receiving unit.
  • the sending unit and the receiving unit respectively implement the sending function and the realization function in the above method.
  • the sending unit may be a transmitter, a transmitter, a sending circuit, an output circuit, an interface of a communication chip, or other means that recognize that the sending function can be realized.
  • the receiving unit may be a receiver of a base station, a receiver, a receiving circuit, an input circuit, an interface of a communication chip, or any other means that can realize a receiving function.
  • a communication system including a source base station and a target base station:
  • the target base station for receiving the data packet from the user equipment to the P i that P N, the data packet P I P packet is transmitted from the user equipment to the source base station 1 to P N in the not For the first data packet correctly received by the source base station, N is an integer greater than or equal to 1, and i is an integer greater than or equal to 1 and less than or equal to N;
  • the target base station is also used to send data packets P i to P N to core network equipment;
  • the source base station for transmitting data packets before the data packets to the core network device P 1 to P N P I in the data packet to.
  • the above-mentioned uplink transmission scheme reduces the possibility of packet loss and improves the reliability of data transmission.
  • the target base station before the target base station receives the data packets P i to P N , the target base station is further configured to send indication information to the source base station, where the indication information instructs the user equipment to send The target base station sends the data packets P i to P N.
  • a communication method, communication device and communication system receives the first group of data packets from the user equipment, and sends the first group of data packets to the core network device.
  • the target base station receives the second group of data packets from the user equipment, and sends the second group of data packets to the core network device.
  • the first group of data packets are data packets that are correctly received by the source base station among data packets sent by the user equipment to the source base station
  • the second group of data packets are data packets that the user equipment sends to the source base station. Retransmission data packets of data packets that have not been correctly received by the source base station among the sent data packets;
  • This communication method can reduce the possibility of packet loss and improve the reliability of data transmission.
  • the first group of data packets are data packets with discontinuous indexes.
  • the units in the communication device described in the foregoing aspects may be implemented by software, or hardware, or a combination of software and hardware.
  • the communication device described in each of the foregoing aspects includes one or more processors, and one or more memories, and the memory stores that can be executed by the one or more processors.
  • the communication device executes the methods described in the above aspects.
  • Another aspect of the present application provides a computer-readable storage medium having instructions stored in the computer-readable storage medium, which when run on a computer, cause the computer to execute the methods described in the above aspects.
  • Another aspect of the present application provides a computer program product containing instructions, which when run on a computer, causes the computer to execute the methods described in the above aspects.
  • FIG. 1 is a schematic diagram of a possible system structure for implementing an embodiment of the present invention
  • FIG. 2 is a flowchart of a communication method provided by an embodiment of the present invention.
  • Figure 2a is a flowchart of a communication method provided by an embodiment of the present invention.
  • FIG. 3 is a flowchart of another communication method provided by an embodiment of the present invention.
  • FIG. 5 is a flowchart of another uplink data transmission method according to an embodiment of the present invention.
  • Figure 6 is a schematic diagram of a protocol stack provided by an embodiment of the present invention.
  • FIG. 7 is a schematic diagram of another protocol stack provided by an embodiment of the present invention.
  • FIG. 8 is a schematic diagram of another protocol stack provided by an embodiment of the present invention.
  • FIG. 9 is a schematic diagram of another protocol stack provided by an embodiment of the present invention.
  • FIG. 10 is a schematic structural diagram of a base station provided by an embodiment of the present invention.
  • FIG. 11 is a schematic structural diagram of another base station provided by an embodiment of the present invention.
  • FIG. 12 is a schematic structural diagram of a user equipment according to an embodiment of the present invention.
  • FIG. 13 is a schematic structural diagram of another user equipment provided by an embodiment of the present invention.
  • FIG. 1 shows a schematic diagram of a possible system network of the present application.
  • the RAN includes at least two base stations: base station 20 and base station 30. Only two base stations and one user equipment UE are shown in the figure.
  • the RAN is connected to a core network (core network, CN).
  • the core network includes one or more core network devices.
  • the CN may be coupled to one or more external networks (External Network), such as the Internet, a public switched telephone network (PSTN), and so on.
  • PSTN public switched telephone network
  • the base station 20 may be referred to as the source base station
  • the base station 30 may be referred to as the target base station.
  • the communication device described in this application refers to a network element in a communication system, such as a terminal, a base station (a source base station or a target base station), and core network equipment.
  • the terminal is sometimes also called User Equipment (UE).
  • UE User Equipment
  • a UE is a terminal device with a communication function, which may also be called a terminal, and may include a handheld device with a wireless communication function, a vehicle-mounted device, a wearable device, a computing device, or other processing devices connected to a wireless modem.
  • user equipment can be called different names, such as: terminal, mobile station, subscriber unit, station, cellular phone, personal digital assistant, wireless modem, wireless communication equipment, handheld device, laptop computer, cordless phone, Wireless local loop station, etc.
  • this application is referred to as user equipment UE or terminal for short.
  • the base station may be a wireless access device or a relay station in a cloud network and other devices with wireless transceiver functions.
  • a base station can also be called a base station device, which is a network device deployed on a wireless access network to provide wireless communication functions.
  • the name of the base station may be different in different wireless access systems.
  • the base station is called NodeB
  • the base station in the LTE network is called NodeB.
  • It is an evolved NodeB (evolved NodeB, eNB or eNodeB), which may be called a Transmission Reception Point (TRP) or gNodeB (gNodeB, gNB) in a 5G system.
  • TRP Transmission Reception Point
  • gNodeB gNodeB
  • the base station can contain one or more co-site or non-co-site TRPs.
  • the base station may also be a wireless controller, a centralized unit (CU), and/or a distributed unit (DU) in a cloud radio access network (cloud radio access network, CRAN) scenario.
  • the base station can also be a server, a wearable device, or a vehicle-mounted device.
  • the base station is used for description below.
  • the base station in the present invention may also be a user equipment in Device to Device (D2D).
  • the base station and user equipment in the present invention may also be relay equipment, or network equipment or user equipment that implements a relay function.
  • the following uses a 5G network as an example to describe the solutions provided by the embodiments of the present invention, but the solutions of the present invention are not limited to 5G networks.
  • the solutions of the present invention can also be applied to LTE, or subsequent evolution networks, or multiple converged networks, etc. This embodiment of the present invention does not limit this.
  • This embodiment provides a communication method, device and system. This solution can be applied to the system shown in Figure 1. as shown in picture 2:
  • Step 201 The source base station sends a handover request message to the target base station.
  • the source base station when the source base station determines that the UE needs to be handed over from the source base station to the target base station, it sends a handover request message to the target base station to request the UE to be handed over to the target base station.
  • Step 202 In response to the handover request message, the target base station sends a request message to the first core network device to request a copy of the first data packet, where the first data packet is the second core network device's request to the source base station.
  • the first core network device may be an Access and Mobility Management Function (AMF) device
  • the second core network device may be a User Plane Function (UPF) device.
  • AMF Access and Mobility Management Function
  • UPF User Plane Function
  • the first core network device and the second core network device may be the same core network device or different core network devices.
  • the first core network device or the second core network device may include the function of the core network device unless otherwise specified.
  • the foregoing request message may be, for example, a duplication request (duplication request) message, or the request message has other expressions and naming methods, which are not limited.
  • the target base station sending a request message may also be understood as requesting the core network device to send the first data packet to the source base station, and requesting the core network device to send the target The base station sends a copy of the first data packet.
  • the copy of the first data packet may be referred to as the second data packet.
  • At least the payload (payload) of the first data packet and the second data packet is the same.
  • the content of the first data packet and the second data packet may be completely the same or not completely the same (for example, the payload is the same, and other information is different).
  • the core network device may include one or more of the following functional entities: Access and Mobility Management Function (AMF), Session Management Function (SMF), or User Plane Function (User Plane Function, UPF).
  • AMF Access and Mobility Management Function
  • SMF Session Management Function
  • UPF User Plane Function
  • the AMF is sometimes also called AMF device, AMF entity or other names
  • SMF is sometimes called SMF device, SMF entity or other names
  • UPF is sometimes called UPF device, UPF entity or other names.
  • the core network equipment may also include other functional entities. These functional entities may be separate physical entities, or may be physically integrated together, which is not limited in the embodiment of the present invention.
  • the target base station requests the second core network device to send a copy of the first data packet to the target base station, which may specifically be:
  • the target base station sends the above request message to the Access and Mobility Management Function (AMF) device, and the request message may include a protocol data unit (Protocol Data Unit, PDU) session identifier (such as PDU session ID), The QoS Flow identifier accepted/allowed by the source base station (such as the list of accepted QoS Flow ID(s)).
  • the request message may also include the address information of the target base station and UE identification information;
  • the AMF device receives the above request message After that, it performs a session update (session update) process with a Session Management Function (SMF) device; the SMF device performs a session modification (session modification) process with a User Plane Function (UPF) device.
  • PDU Protocol Data Unit
  • UPF User Plane Function
  • the address information of the target base station may be at least one of the following: an IP address, or a GPRS tunneling protocol tunnel endpoint identifier (GTP Tunnel Endpoint Identifier, GTP TEID).
  • the address information of the target base station can be used by the core network device to determine the address of the target base station, so that the core network device can establish a data transmission channel with the target base station;
  • the UE identification information can include at least one of the following: RAN UE NGAP ID , Source NG-RAN node UE XnAP ID reference, Source AMF UE NGAP ID, where RAN UE NGAP ID (the new generation application protocol identifier of wireless access network user equipment) is the identifier assigned by the source base station, and the NG interface (ie NG-RAN
  • the interface between the node and the core network equipment, such as AMF equipment, can identify the UE according to the identifier;
  • Source AMF UE NGAP ID Source Access and Mobility Management Function User Equipment New Generation Application
  • the NG interface (ie the interface between the NG-RAN node and the core network equipment, such as AMF equipment) can identify the UE based on the identifier , And the identifier can be used to index the UE context information at the source AMF device (or serving AMF device, that is, the AMF device connected to the source base station);
  • Source NG-RAN node UE XnAP ID reference source new generation radio access network node user
  • the device Xn application protocol identification reference is an identification assigned by the source base station, and the UE can be identified on the Xn interface (that is, the interface between two base stations) based on the identification.
  • the UE identification information can be used to uniquely identify the user equipment in the access network RAN (e.g., base station) or core network CN (e.g., core network equipment), so that the core network equipment can establish a channel for data transmission between the core network equipment and the target base station.
  • the access network RAN e.g., base station
  • core network CN e.g., core network equipment
  • the session update request message (such as session update request message) may include the PDU session ID, the QoS Flow identifier accepted/allowed by the source base station, and the address information of the target base station And at least one of the UE identification information, which is not limited in this embodiment of the present invention;
  • the session modification request message (such as the session modification request message) may include At least one of the PDU session ID, the QoS Flow identifier accepted/allowed by the source base station, the address information of the target base station, and the UE identification information, which is not limited in this embodiment of the present invention.
  • the AMF device and the SMF device perform a session update (session update) process
  • the SMF device and the UPF device perform a session modification (session modification) process.
  • the AMF device sends a session update request message to the SMF device.
  • the SMF device After receiving the request message, the SMF device sends a session modification request to the UPF device.
  • the UPF device modifies the session according to the request of the SMF device.
  • the SMF device replies with a session modification request ACK message.
  • the SMF device After receiving the ACK message, the SMF device sends a session update request ACK message to the AMF device.
  • the AMF device After the AMF device receives the ACK message, the AMF device sends the target base station to the target base station corresponding to the AMF device.
  • a sent request message such as a backup request message
  • a backup request confirmation message duplication request ACK such as a backup request confirmation message duplication request ACK
  • the UPF device device performs data packet duplication, the UPF device sends the first data packet to the source base station, and the UPF device sends a copy of the first data packet to the target base station, which can be called
  • the first data packet and the copy of the first data packet may be collectively referred to as a duplication data packet.
  • the user equipment performs data packet duplication, that is, the process in which the user equipment sends a fifth data packet to the source base station, and the user equipment sends a copy of the fifth data packet to the target base station, which may also be called duplication.
  • the fifth data packet and the copy of the fifth data packet can be collectively referred to as a duplication data packet.
  • the data carried in the data packet and the corresponding copy of the data packet may or may not be exactly the same.
  • the data packet and the corresponding copy of the data packet at least the payload (such as payload) is the same, but the other information carried in the two data packets can be the same or different.
  • the two data The address information carried in the packets are different.
  • one of the data packets carries the address information of the source base station
  • the corresponding copy of the data packet carries the address information of the target base station. Other differences are here. Do not repeat it.
  • the target base station after the target base station receives the handover request message, it starts the tunnel establishment process between the target base station and the core network equipment (for example, AMF equipment, SMF equipment, UPF equipment), that is, establishes Start the transmission channel between the target base station, AMF equipment, SMF equipment, and UPF equipment.
  • the UPF device can send backup data packets to the source base station and the target base station respectively, and then the source base station and the target base station can respectively send the backup data packets received from the UPF device to the user equipment, and the source base station does not need to forward to the target base station Data, reducing the transmission delay caused by the data forwarding process.
  • the above method further includes:
  • Step 203 The source base station receives the first data packet from the second core network device.
  • Step 204 The target base station receives a second data packet from the second core network device.
  • the above method further includes:
  • Step 205 In response to the first data packet, the source base station sends a third data packet to the user equipment.
  • Step 206 In response to the second data packet, the target base station sends a fourth data packet to the user equipment.
  • the process in which the source base station sends the third data packet to the UE and the target base station sends the fourth data packet to the UE may also be referred to as a duplication process.
  • the third data packet and the copy of the third data packet (that is, the fourth data packet) may also be collectively referred to as a duplication data packet.
  • the first data packet and the copy of the first data packet carry the same data for the UE (for example, the same payload), but the headers can be different (for example, address information). different).
  • the source base station after the source base station receives the first data packet, it can perform corresponding processing on the first data packet, such as data analysis, header processing, etc., and then send the data packet to the UE, but the payload of the UE data packet is not Changes.
  • the target base station processes the copy of the first data packet similarly.
  • the UPF device needs to send When the first data packet is backed up, an indication information can be sent to the source base station.
  • the indication information is an end marker.
  • the indication information is used to notify the source base station that the UPF device starts the duplication function, that is, the UPF device is about to start sending the source
  • the base station sends the data packet and sends a copy of the corresponding data packet to the target base station.
  • the indication information may also be carried in the header of the first backup data packet sent by the UPF device to the source base station after the UPF device starts the duplication process.
  • the indication information may be included in the GTP-U header, which is not included in the present invention. Make a limit.
  • the source base station receives the indication information, there are still unsent data packets for the UE in the data buffer area of the source base station, that is, there are data packets buffered in the data buffer area of the source base station before the duplication process starts.
  • the source base station sends the above unsent data packets for the UE to the user equipment first by default, and the source base station Send the unsent data packets for the UE to the user equipment and then send the backup data packets received from the UPF device to the user equipment; or, in another implementation manner, the above instructions sent by the UPF device to the source base station Information can also be understood as that the indication information is used to instruct the source base station to preferentially send unsent data packets for the UE to the user equipment, that is, after the source base station receives the indication information, the indication information may be an end marker or included in The indication information in the header of the first backup data packet sent by the UPF device to the source base station.
  • the source base station preferentially sends the unsent data packets for the UE to the user equipment, and the source base station sends the unsent data packets for the UE. After being sent to the user equipment, the backup data packet received from the UPF device is sent to the user equipment. This embodiment does not limit this.
  • the UPF device starts the duplication process (for example, after the channel for transmitting backup data packets between the target base station, AMF device, SMF device, and UPF device is successfully established)
  • the UE can also send data packets to the source base station and send corresponding data to the target base station A copy of the package.
  • the source base station and the target base station may respectively send the foregoing data packet and a corresponding copy of the foregoing data packet to the UPF device.
  • the process in which the source base station sends the foregoing data packet to the UPF device and the target base station sends a copy of the foregoing data packet to the UPF device may also be referred to as a duplication process.
  • the foregoing data packet and the copy of the foregoing data packet may also be collectively referred to as a duplication data packet.
  • a transmission channel is established between the target base station and the core network device, and duplication operation is enabled. Furthermore, before the link quality between the UE and the source base station deteriorates, That is, the channel between the target base station and the core network equipment for transmitting the backup data packet is successfully established. Therefore, the data that the source base station cannot successfully transmit can be transmitted through the target base station, which reduces the data transmission delay during the handover and guarantees Improve the reliability of data transmission.
  • the UPF device can send a data packet to the source base station and send a copy of the data packet to the target base station.
  • the source base station sends the data packets received from the UPF device to the user equipment
  • the target base station sends the data packets received from the UPF device to the user equipment.
  • the UE receives the data packets from the source base station and the target base station respectively, it needs to check the slave
  • the data packets received at the source base station and the target base station are subjected to operations such as duplicate packet detection, data packet reordering, and/or order delivery, so that the UE can correctly perform duplicate packet detection or data packet reordering or order delivery.
  • the source base station or the target base station serves as the access network device, and when performing uplink or downlink transmission, the received data packet from the core network device is sent to the UE or During the process of sending the received data packet from the UE to the core network device, necessary processing may be performed on the data packet, such as packet header processing, rearrangement and other operations, or transparent transmission.
  • this application does not limit this when it relates to related technologies, unless explicitly stated.
  • the solution provided by this embodiment includes:
  • Step 301 The source base station receives the first data packet from the core network device.
  • the core network device may be a UPF device.
  • Step 302 The target base station receives a second data packet from the core network device, the second data packet is a copy of the first data packet, and the first data packet and the second data packet respectively include The first index.
  • the value of the first index respectively included in the first data packet and the second data packet are the same. At least the payload (payload) of the first data packet and the second data packet is the same.
  • the data packet and the copy of the data packet may be completely the same, or the effective payload carried by the two may be the same, but other information, such as the header and other information, are different.
  • the first index is a high-level sequence number
  • the first index may be a GPRS tunnel protocol-user plane (GPRS tunnel protocol-user plane, GTP-U) sequence number (SN); or,
  • the first index may be the sequence number of the upper layer protocol stack of the GTP-U protocol layer, for example, the first index may be the transmission control protocol (Transmission Control Protocol, TCP) sequence number or other upper layer protocols of the GTP-U protocol layer
  • TCP Transmission Control Protocol
  • the layer sequence number is not limited to this embodiment of the present invention; alternatively, a new protocol layer can be introduced into the existing protocol stack, and the first index can be the protocol layer sequence number corresponding to the newly introduced protocol layer, In an example, a new protocol layer is introduced at the upper layer of the GTP-U protocol layer.
  • the newly introduced protocol layer is the High Reliability Protocol (HRP), and the first index may be the HRP sequence number.
  • HRP High Reliability Protocol
  • the embodiment of the present invention sets no limitation. It should be noted that the newly introduced protocol layer may have other naming or representation forms, which are not limited in the embodiment of the present invention.
  • the value of the first index is at a flow granularity (Quality of Service, QoS). That is, the first indexes included in the data packets respectively corresponding to different QoS flows are individually numbered.
  • the values of the first index included in the data packets respectively corresponding to different QoS flows may be the same or different, which is not limited in this embodiment of the present invention. Since the QoS flow can be at the granularity of the Data Radio Bearer (DRB), that is, only one QoS flow can be mapped to the same DRB, and different QoS flows are mapped to different DRBs. Therefore, the value of the first index It can also be DRB granular.
  • DRB Data Radio Bearer
  • Step 303 The source base station, in response to the first data packet, sends a third data packet to the user equipment, where the third data packet includes a second index.
  • the second index may be a packet data convergence protocol (Packet Data Convergence Protocol, PDCP) sequence number.
  • PDCP Packet Data Convergence Protocol
  • the header information may be the same or different.
  • the first data packet and the third data packet have at least the same payload (such as payload), but the header information included in the first data packet is the same or different from the header information included in the third data packet.
  • the third data The packet includes PDCP SN, but the first data packet does not include PDCP SN.
  • there may be other differences in the header information which will not be repeated here.
  • Step 304 The source base station sends first indication information to the target base station, where the first indication information indicates a mapping relationship between the first index and the second index corresponding to the first index.
  • step 303 and step 304 are not strictly sequential. For example, step 303 may be performed first, and then step 304 may be performed, or step 304 may be performed first, and then step 303 may be performed, or steps 303 and 304 may be performed simultaneously.
  • the header of the data packet sent by the UPF device to the source base station carries the first index, for example, the GTP-U header carries GTP-U SN .
  • the mapping between the first index and the second index corresponding to the first index has been determined, for example, the mapping relationship between PDCP SN and GTP-U SN is determined.
  • the source base station may determine the mapping relationship between the first index of the DL and the second index corresponding to the first index, that is, the first indication information , Included in the handover request message sent to the target base station.
  • the first indication information may also be included in other messages and sent to the target base station, which is not limited.
  • the header of the data packet sent by the UPF device to the source base station does not carry the first index, for example, the GTP-U header does not carry GTP- U SN.
  • the header of the data packet sent by the UPF device to the source base station carries the first index. For example, the UPF device starts from the first backup packet and carries GTP-U SN in the GTP-U header of the backup packet. .
  • the GTP-U SN is not included in the data packet, that is, the source base station cannot determine the mapping relationship between the first index and the second index corresponding to the first index.
  • the GTP-U header carries the GTP-U SN.
  • the UPF device wants to send the first duplication packet to the source base station, the UPF device can first send an indication message to the source base station. For example, end marker, or the header of the first duplication data packet sent by the UPF device to the source base station carries an indication information.
  • the above indication information is used to notify the source base station that the UPF device starts sending the duplication data packet and the source base station receives the UPF.
  • the source base station can determine the mapping relationship between GTP-U SN and PDCP SN of the DL, and send the mapping relationship to the target base station. Specifically, the newly defined Xn message ( Messages transmitted between two base stations), or reuse the existing Xn message to send the mapping relationship, such as the existing SN status transfer message, which is not limited in the embodiment of the present invention.
  • the target base station After receiving the mapping relationship, the target base station starts to send the DL duplication data packet received from the UPF device to the UE. If the target base station receives the data packet sent by the UPF device before learning the mapping relationship, the target base station buffers the data packet.
  • Step 305 The target base station sends a fourth data packet to the user equipment in response to the second data packet, where the third data packet and the fourth data packet each include a second index.
  • the contents of the data carried in the second data packet and the fourth data packet are at least the same, but the header information may be the same or different.
  • the second data packet and the fourth data packet have at least the same payload (such as payload), but the header information included in the second data packet and the header information included in the fourth data packet may be the same or different.
  • the fourth data packet includes PDCP SN, but the second data packet does not include PDCP SN. Other differences are not described here.
  • mapping relationship between the above-mentioned first index and the second index corresponding to the above-mentioned first index can be indicated in various ways. Several possible implementation manners are given below:
  • the first indication information includes the value of the first index and the value of the second index corresponding to the first index.
  • the GTP-U SN carried in the data packet received by the source base station from the UPF device is 1, and the source base station determines that the PDCP SN corresponding to the data packet is 2, according to the current data transmission situation, and the first indication information indicates
  • the mapping relationship can be shown in Table 1 below.
  • the first indication information includes ⁇ GTP-U SN, PDCP SN ⁇ of DL.
  • the sequence of GTP-U SN and PDCP SN can be interchanged. For example, as shown in Table 2, this embodiment of the present invention does not limit it.
  • the specific values of GTP-U SN and PDCP SN can be specifically determined by the source base station according to the received data packet. Another possibility is that in addition to the source base station receiving a data packet carrying GTP-U SN of 1, from the UPF device, the source base station also receives a data packet carrying GTP-U SN of 2, 3, etc. from the UPF device. The source base station is based on the current According to the data transmission situation, it is determined that the PDCP SN corresponding to the data packet carrying GTP-U SN of 2 is 3, and the PDCP SN corresponding to the data packet carrying GTP-U SN of 3 is 4, and so on, so I will not repeat it. .
  • the mapping relationship indicated by the first indication information may also be as shown in Table 3 below.
  • the value of the specific serial number carried in the first indication information is not specifically limited, as long as the mapping relationship between the first index and the second index corresponding to the first index can be indicated. .
  • the first indication information includes a mapping formula between the first index and the second index corresponding to the first index.
  • the specific value of delta can be flexibly determined by the source base station according to specific data transmission conditions.
  • delta can be any natural number.
  • PDCP SN GTP-U SN-delta.
  • the specific expression method used can be flexibly determined by the source base station.
  • the first indication information includes a difference between the first index and the value corresponding to the second index corresponding to the first index.
  • the first indication information carries the difference between the two indexes, such as delta1.
  • the specific value of delta1 can be flexibly determined by the source base station according to the specific data transmission situation.
  • delta1 can be any natural number.
  • the specific expression method used can be flexibly determined by the source base station.
  • the user equipment after receiving the third data packet from the source base station and the fourth data packet from the target base station, the user equipment performs repeated packet detection, data packet reordering, and data packet reordering on the third data packet and the fourth data packet. And/or order delivery and other operations, because the source base station and the target base station use the same mapping relationship, it ensures that the user equipment can correctly perform duplicate packet detection or data on the backup data packets received from the source base station and the target base station. Packages are reordered or delivered in order.
  • the above-mentioned embodiments are for downlink data transmission, and another scheme for uplink data transmission is given below.
  • the uplink transmission scheme and the downlink transmission scheme can be implemented separately or can be combined and applied to the same system.
  • the method provided in this embodiment includes:
  • Step 306 The source base station receives the fifth data packet from the UE.
  • Step 307 The target base station receives a sixth data packet from the UE, the sixth data packet is a copy of the fifth data packet, and the fifth data packet and the sixth data packet are both separately Including the third index.
  • the value of the third index included in the fifth data packet and the sixth data packet are the same.
  • At least the payload (such as payload) of the fifth data packet and the sixth data packet is the same.
  • the third index may be PDCP SN.
  • the payload (such as the payload) of the fifth data packet and the sixth data packet is the same, but other information carried by the two data packets may be the same or different.
  • the address information carried in the two data packets are different.
  • the fifth data packet carries the address information of the source base station
  • the sixth data packet carries the address information of the target base station.
  • I won’t repeat it here.
  • Step 308 The source base station sends a seventh data packet to the core network device in response to the fifth data packet.
  • the core network device may be a UPF device, and the seventh data packet includes a fourth index.
  • the contents of the data carried in the fifth data packet and the seventh data packet are the same, but the header information may be the same or different.
  • the fifth data packet and the seventh data packet have at least the same payload (such as payload), but the header information included in the fifth data packet and the header information included in the seventh data packet may be the same or different.
  • the seventh data packet includes a high-level sequence number (that is, a fourth index), for example, the high-level sequence number may be GTP-USN; or, the high-level sequence number may be the sequence of the upper layer protocol stack of the GTP-U protocol layer
  • the high-level sequence number may be TCP SN or other upper-layer protocol layer sequence numbers of the GTP-U protocol layer, which is not limited in this embodiment of the present invention; or, a new one may be introduced into the existing protocol stack Protocol layer, the upper layer sequence number may be the protocol layer sequence number of the newly introduced protocol layer.
  • a new protocol layer is newly introduced in the upper layer of the GTP-U protocol layer.
  • the newly introduced protocol layer is the High Reliability Protocol (HRP), and the high-level sequence number can be HRP SN, this embodiment of the present invention does not limit this. It should be noted that the newly introduced protocol layer may have other naming or representation forms, which are not limited in the embodiment of the present invention.
  • HRP High Reliability Protocol
  • HRP SN High-level sequence number
  • the fifth data packet and the seventh data packet have at least the same payload, but the fifth data packet does not include the above-mentioned high-level sequence number, and other differences are not described here.
  • Step 309 The source base station sends third indication information to the target base station, where the third indication information indicates a mapping relationship between the third index and the fourth index corresponding to the third index.
  • step 309 may be performed before step 308, or after step 308, or simultaneously with step 308, which is not limited in this embodiment of the present invention.
  • the third indication information in a possible implementation manner, for uplink data, when the UE does not start the duplication operation, after the source base station receives the data packet sent by the UE, it performs necessary processing on the header of the data packet.
  • the fourth index is carried in the header of the data packet, for example, the source base station carries GTP-U SN in the GTP-U header of the data packet. Then, before the handover process occurs, for example, before the source base station and the UPF device perform UL backup data packet transmission, or during UL backup data packet transmission, or after UL backup data packet transmission, the third index and the third index can be determined.
  • the mapping relationship between the fourth indexes corresponding to the indexes such as determining the mapping relationship between PDCP SN and GTP-U SN.
  • the source base station may determine the mapping relationship between the third index of the UL and the fourth index corresponding to the third index, that is, the third indication information, It is included in the handover request message and sent to the target base station.
  • the third indication information may also be included in other messages and sent to the target base station, which is not limited in the embodiment of the present invention.
  • the source base station when the UE does not start the duplication operation, after the source base station receives the data packet sent by the UE, the source base station does not carry the fourth in the header of the data packet.
  • Index for example, GTP-U SN is not carried in the GTP-U header.
  • the source base station After the UE starts the duplication operation, after the source base station receives the first backup data packet that the UE starts to send, the source base station carries the fourth index in the header of the data packet, such as the GTP-U SN in the GTP-U header.
  • the data packet sent by the source base station to the UPF device does not include GTP-U SN, that is, the source base station cannot determine the third index and the corresponding third index.
  • the mapping relationship between the fourth index For uplink, after the source base station receives the first duplication data packet sent by the UE, the source base station carries the GTP-U SN in the GTP-U header of the received backup data packet.
  • the UE When the UE wants to send the first duplication packet to the source base station, the UE first sends an indication information to the source base station, for example, an end marker, or the header of the first duplication data packet sent by the UE to the source base station carries one Indication information, the above indication information is used to notify the source base station UE to start sending duplication data packets.
  • the source base station After the source base station receives the first duplication data packet sent by the UE, the source base station can determine the mapping between UL GTP-U SN and PDCP SN The mapping relationship is sent to the target base station. Specifically, the mapping relationship can be sent through a newly defined Xn message or reuse an existing Xn message, such as an SN status transfer message, which is not limited in the embodiment of the present invention.
  • the target base station After receiving the mapping relationship, the target base station sends the UL duplication data packet received from the UE to the UPF device.
  • mapping relationship between the foregoing third index and the fourth index corresponding to the third index may have multiple indication methods, and several optional methods are given below:
  • the third indication information includes the value of the third index and the value of the fourth index corresponding to the third index.
  • the PDCP SN carried in the data packet received by the source base station from the UE is 5.
  • the source base station determines that the GTP-U SN corresponding to the data packet is 3 according to the current data transmission situation, and the third indication information indicates The mapping relationship can be shown in Table 4 below.
  • the third indication information includes UL's ⁇ GTP-U SN, PDCP SN ⁇ .
  • the sequence of GTP-U SN and PDCP SN can be interchanged, for example, as shown in Table 5, the embodiment of the present invention does not limit it.
  • the specific values of GTP-U SN and PDCP SN can be specifically determined by the source base station according to the received data packet. For example, another possibility is that the source base station receives a data packet carrying a PDCP SN of 5 from the UE. The UE receives data packets carrying PDCP SN 2, 3, 6, etc., and the source base station determines that the GTP-U SN corresponding to the data packet carrying PDCP SN 2 is 0 according to the current data transmission situation, and the PDCP SN carrying PDCP is The GTP-U SN corresponding to the data packet of 3 is 1, and the GTP-U SN of the data packet carrying the PDCP SN of 6 is 4, and so on, and will not be repeated. Then the mapping relationship indicated by the third indication information may also be shown in Table 6 below.
  • the value of the specific serial number carried by the third indication information is not specifically limited, as long as the mapping relationship between the third index and the fourth index corresponding to the third index can be indicated. .
  • the third indication information includes a mapping formula between the third index and the fourth index corresponding to the third index.
  • the specific value of delta' can be flexibly determined by the source base station according to the specific data transmission situation.
  • delta' can be any natural number.
  • PDCP SN GTP-U SN-delta’.
  • the specific expression method used can be flexibly determined by the source base station.
  • the delta included in the first indication information and the delta' included in the third indication information may be the same or different, which is not limited in the embodiment of the present invention.
  • the third indication information includes the difference between the third index and the numerical value corresponding to the fourth index corresponding to the third index.
  • the third indication information carries the difference between the two indexes, such as delta2.
  • the specific value of delta2 can be flexibly determined by the source base station according to specific data transmission conditions.
  • delta2 can be any natural number.
  • the specific expression method used can be flexibly determined by the source base station.
  • the delta1 included in the first indication information may be the same or different from the delta2 included in the third indication information, which is not limited in the embodiment of the present invention.
  • mapping relationship between the GTP-U SN of UL and the PDCP SN corresponding to the GTP-U SN, and the relationship between the GTP-U SN of DL and the PDCP SN corresponding to the GTP-U SN may be included in the same indication information or different indication information, which is not limited in the embodiment of the present invention.
  • the foregoing mapping relationship between the first index and the second index and the mapping relationship between the third index and the fourth index that is, the mapping relationship between UL and DL, may be carried by the same Xn message or different Xn messages.
  • the Xn message may be a handover request message or an SN status transfer message, which is not limited in the embodiment of the present invention.
  • the specific mapping relationship of UL and the specific mapping relationship of DL may be the same or different, which is not limited in the embodiment of the present invention.
  • Step 310 The target base station sends an eighth data packet to the core network device in response to the sixth data packet, where the seventh data packet and the eighth data packet each include a fourth index.
  • the core network device may be a UPF device.
  • the fourth index is the high-level sequence number, for example, the fourth index may be GTP-USN; or, the fourth index may be the sequence number of the upper layer protocol stack of the GTP-U protocol layer, for example, the fourth index may be The protocol layer sequence numbers of other upper layers of the TCP SN or GTP-U protocol layer are not limited in this embodiment of the present invention; or, a new protocol layer can be introduced into the existing protocol stack, and the fourth index can be the The protocol layer sequence number corresponding to the newly introduced protocol layer is an example.
  • a new protocol layer is introduced in the upper layer of the GTP-U protocol layer.
  • the newly introduced protocol layer is the High Reliability Protocol (HRP).
  • HRP High Reliability Protocol
  • the fourth index may be HRP SN, which is not limited in this embodiment of the present invention. It should be noted that the newly introduced protocol layer may have other naming or representation forms, which are not limited in the embodiment of the present invention.
  • the value of the fourth index is based on a flow granularity (Quality of Service, QoS). That is, the fourth indexes included in the data packets corresponding to different QoS flows are independently numbered.
  • the value of the fourth index included in the data packets corresponding to different QoS flows may be the same or different, which is not limited in this embodiment of the present invention.
  • the QoS flow can be at the granularity of the Data Radio Bearer (DRB), that is, only one QoS flow can be mapped to the same DRB, and different QoS flows are mapped to different DRBs. Therefore, the value of the fourth index It can also be DRB granular.
  • DRB Data Radio Bearer
  • the data carried in the sixth data packet and the eighth data packet are at least the same in content, but the header information may be the same or different.
  • the sixth data packet and the eighth data packet have at least the same payload (such as payload), but the header information included in the sixth data packet is the same or different from the header information included in the eighth data packet.
  • the eighth data packet includes the fourth index, but the sixth data packet does not include the fourth index. Other differences are not described here.
  • the UPF device after receiving the seventh data packet from the source base station and the eighth data packet from the target base station, the UPF device performs repeated packet detection, data packet reordering, and data packet reordering on the seventh data packet and the eighth data packet. And/or order delivery and other operations, because the source base station and the target base station use the same mapping relationship, it ensures that the UPF device can correctly perform duplicate packet detection or data on the backup data packets received from the source base station and the target base station. Packages are reordered or delivered in order.
  • the source base station can send the SN Status Transfer message to the target base station.
  • the SN status transfer message indicates the SN of the first lost uplink data packet and the UE needs to be re-transmitted at the target base station.
  • the reception status of the transmitted uplink data packet; for the downlink, the SN status transfer message indicates that when the target base station needs to perform PDCP SN allocation for the downlink data packet newly received from the UPF device without a PDCP sequence number, the target base station is allocated The value of the initial PDCP SN (that is, the value of the PDCP SN from which the target base station assigns a sequence number).
  • the source base station does not need to send an SN status transfer message to the target base station by default.
  • the target base station is based on the PDCP SN and the UL GTP-U SN notified by the source base station.
  • the mapping relationship between PDCP and SN corresponding to the GTP-U SN determines the value of GTP-U SN.
  • the source base station may not perform the SN status transfer process; for DL data transmission, the target base station is based on the GTP-U header of the data packet
  • the core network device can notify the source base station whether it needs to perform the SN status transfer message transmission during the handover process, for example, when the UPF device starts the backup packet transmission (for example, after the channel for transmitting backup data packets between the target base station, AMF device, SMF device, and UPF device is successfully established), the UPF device can send an indication message to the source base station.
  • the indication information can be end marker or The indication information is the indication information included in the header of the first duplication data packet sent by the UPF device to the source base station.
  • the indication information included in the header of the first duplication data packet sent by the source base station is a binary value "0" or "1"
  • "1” indicates that the source base station needs to send an SN status transfer message to the target base station
  • "0" indicates the source
  • the base station does not need to send the SN status transfer message to the target base station
  • the specific form of the indication information is not limited in the embodiment of the present invention.
  • the first duplication data packet may be one or more data packets.
  • the first duplication data packet is the first data packet sent by the UE to the source base station or the target base station after the UE starts the duplication process, or the first group of data packets, or the first data packet in the first group of data packets;
  • the first duplication data packet is the first data packet sent by the core network device to the source base station or the target base station after the core network device starts the duplication process, or the first group of data packets, or the first group of data packets. Packets. The embodiment of the present invention does not limit this.
  • the first and second embodiments provide solutions for user equipment and/or core network equipment to start duplication, so that the source base station may not forward data with the target base station, for example, For uplink transmission, the source base station will not forward the out-of-sequence uplink data packets received from the user equipment to the target base station.
  • the out-of-order uplink data packets may include, starting from the first out-of-sequence UL data packet, and All other data packets (if any) after an out-of-sequence packet; for downlink, the source base station will not send the downlink data packets that have been sent to the user equipment but have not been successfully received by the user equipment and the core network equipment will newly send to the source base station The data packet is forwarded to the target base station, thereby reducing the data transmission delay during the handover process.
  • UPF is for downlink data packets that the source base station cannot forward to the target base station.
  • the device can backup/copy these data packets that cannot be forwarded and send them to the target base station, reducing the packet loss rate during the downlink data transmission process.
  • this embodiment provides a solution to the problem of uplink data transmission caused by no data forwarding process between the source base station and the target base station.
  • Step 401 The user equipment sends data packets P 1 , P 2 ... P N to the source base station.
  • packets P 1, P 2 ?? P N includes a third index, e.g. PDCP SN.
  • Step 402 the user equipment transmits data packets to the target base station to P i P N, where P i is the packet data packets P1 to PN in the source base station is not the first packet correctly received, N being greater than or equal to 1
  • P i is the packet data packets P1 to PN in the source base station is not the first packet correctly received, N being greater than or equal to 1
  • An integer of, i is an integer greater than or equal to 1 and less than or equal to N.
  • the data packets P i to P N include a third index, such as PDCP SN.
  • the UE determines that the data packet P i for the data packet P 1 to P N in the source base station is not the first packet correctly received.
  • Step 403 The target base station receives the data packets P i to P N.
  • the third indexes respectively included in the data packets P1 to PN are continuous and increasing.
  • Step 404 The target base station sends data packets P i to P N to the core network device.
  • the target base station determines the data packet P according to the mapping relationship between the third index and the fourth index corresponding to the third index, for example, the mapping relationship between PDCP SN and GTP-U SN i to fourth indexes included in the P N headers, respectively.
  • the fourth index is the high-level sequence number, for example, the fourth index may be GTP-USN; or, the fourth index may be the sequence number of the upper layer protocol stack of the GTP-U protocol layer, for example, the fourth index may be The protocol layer sequence numbers of other upper layers of the TCP SN or GTP-U protocol layer are not limited in this embodiment of the present invention; or, a new protocol layer can be introduced into the existing protocol stack, and the fourth index can be the The protocol layer sequence number corresponding to the newly introduced protocol layer is an example.
  • a new protocol layer is introduced in the upper layer of the GTP-U protocol layer.
  • the newly introduced protocol layer is the High Reliability Protocol (HRP).
  • HRP High Reliability Protocol
  • the fourth index may be HRP SN, which is not limited in this embodiment of the present invention. It should be noted that the newly introduced protocol layer may have other naming or representation forms, which are not limited in the embodiment of the present invention.
  • the value of the fourth index is based on a flow granularity (Quality of Service, QoS). That is, the fourth indexes included in the data packets respectively corresponding to different QoS flows are individually numbered.
  • QoS Quality of Service
  • the QoS flow can be at the granularity of the Data Radio Bearer (DRB), that is, only one QoS flow can be mapped to the same DRB, and different QoS flows are mapped to different DRBs. Therefore, the value of the fourth index It can also be DRB granular.
  • DRB Data Radio Bearer
  • the target base station in step 404 may obtain the mapping relationship between the third index and the fourth index corresponding to the third index from the source base station.
  • Step 405 the source base station to the core network apparatus transmits the data packet before the data packet P 1 to P N in P i.
  • the source base station determines the data packet P according to the mapping relationship between the third index and the fourth index corresponding to the third index, for example, the mapping relationship between PDCP SN and GTP-U SN P 1 through PN in the header of all packets prior to i respectively comprising a fourth index.
  • steps 404 and 405 are not limited. For example, step 404 may be executed first and then 405 may be executed, 405 may be executed first then 404 may be executed, or 404 and 405 may be executed simultaneously.
  • the above method further includes:
  • Step 406 the core network device receives the data packets P 1 to P N packets before all P i of the source base station.
  • Step 407 The core network device receives the data packets P i to P N from the target base station.
  • Step 408 the core network device according to a fourth index data packets P 1 to P N included in the repeated detection packet reordering, and / or sequentially submit operation.
  • the UE Before the UE successfully switches to the target base station (the connection between the UE and the target base station has not been successfully established), the UE sends data packets P1, P2, P3, P4, P5, P6, P7, and data packets P1 to P7 to the source base station.
  • PDCP SN is continuous and increasing.
  • the data packets P1, P2, P3, P6, and P7 are correctly received by the source base station (the UE receives the source base station's feedback for the data packets P1, P2, P3, P6, and P7, respectively, as acknowledgement, ACK), and the data packet P4 , P5 is not correctly received by the source base station (the UE does not receive the source base station's feedback for the data packets P4 and P5, or the UE receives the source base station's feedback for the data packets P4 and P5, Negative Acknowledgment, NACK).
  • the source base station Since the source base station did not correctly receive the data packets P4 and P5, although the data packets P6 and P7 were correctly received, the source base station can determine that the data packets P6 and P7 are out of order.
  • the UE After establishing a radio resource control (RRC) connection with the target base station, the UE can send data packets P4, P5, P6, and P7 to the target base station.
  • RRC radio resource control
  • the target base station sends data packets P4, P5, P6, P7 to the core network device.
  • the data packets P4, P5, P6, and P7 sent by the target base station to the core network device respectively include respective corresponding fourth indexes, such as GTP-U SN.
  • the source base station sends data packets P1, P2, P3 to the core network device.
  • the data packets P1, P2, and P3 sent by the source base station to the core network device respectively include respective corresponding fourth indexes, such as GTP-U SN.
  • the UPF device performs operations such as repeated packet detection, reordering, and/or order delivery for all data packets P1 to P7 received from the source base station and the target base station according to the fourth index carried in the data packets P1 to P7.
  • the UE Before the UE successfully switches to the target base station (the connection between the UE and the target base station has not been successfully established), the UE sends data packets P1, P2, P3, P4, P5, P6, P7, and data packets P1 to P7 to the source base station.
  • PDCP SN is continuous and increasing.
  • the data packets P1, P2, P3 are correctly received by the source base station (the UE receives ACKs for the data packets P1, P2, P3 respectively), and the data packets P4, P5, P6, and P7 are not correctly received by the source base station (the UE does not receive
  • the feedback to the source base station for the data packets P4, P5, P6, P7, or the feedback received by the UE for the data packets P4, P5, P6, P7 is NACK).
  • the UE After establishing an RRC connection with the target base station, the UE sends data packets P4, P5, P6, P7 to the target base station.
  • the target base station sends data packets P4, P5, P6, P7 to the core network device.
  • the data packets P4, P5, P6, and P7 sent by the target base station to the core network device respectively include respective corresponding fourth indexes, such as GTP-U SN.
  • the source base station sends data packets P1, P2, P3 to the core network device.
  • the data packets P1, P2, and P3 sent by the source base station to the core network device respectively include respective corresponding fourth indexes, such as GTP-U SN.
  • the UPF device performs operations such as repeated packet detection, reordering, and/or order delivery for all data packets P1 to P7 received from the source base station and the target base station according to the fourth index carried in the data packets P1 to P7.
  • the above method further includes:
  • Step 409 The user equipment receives instruction information from the source base station, where the instruction information instructs the user equipment to send data packets P i to P N to the target base station.
  • the indication information is included in the RRC reconfiguration message.
  • the RRC message may be an RRC reconfiguration message carrying a synchronization reconfiguration information element (reconfiguration with sync) or may be an RRC connection reconfiguration message carrying a mobility control information information element (mobility control info).
  • the above-mentioned indication information may be generated by the source base station and sent to the UE; the above-mentioned indication information may also be generated by the target base station and sent to the source base station, which is transparently transmitted to the UE by the source base station.
  • the base station sends a handover request confirmation message to the source base station, the message includes the indication information.
  • the indication information is transparently transmitted to the UE through the above RRC reconfiguration message.
  • the UE when the UE determines that the data packet Pi is the first data packet among the data packets P1 to PN that has not been correctly received by the source base station, it sends the data packet Pi to the target base station by default. PN.
  • the uplink transmission scheme in this embodiment reduces the possibility of packet loss and improves the reliability of data transmission.
  • This embodiment also provides another uplink data transmission scheme, as shown in Fig. 5, including:
  • Step 501 The user equipment sends data packets P 1 , P 2 ... P N to the source base station, where N is an integer greater than or equal to 1.
  • packets P 1, P 2 ?? P N includes a third index, e.g. PDCP SN.
  • Step 502 The source base station receives the first group of data packets from the user equipment.
  • a first group of data packets may include data packets P 1, P 2 ?? P N in at least one data packet.
  • Step 502 is an optional step.
  • the data packets in the first group of data packets respectively include a third index, such as PDCP SN.
  • Step 503 The user equipment sends a second group of data packets to the target base station.
  • the second group of data packets is a packet of the packet data P of the user equipment to the source base station 1, P 2 ?? P N in the source base station is not correctly received retransmitted data packet.
  • the second group of data packets includes at least one data packet.
  • the data packets in the second group of data packets respectively include the third index.
  • the retransmission of the data packet may refer to the above-mentioned data packet that the UE sends to the source base station and is not correctly received by the source base station, and then the UE sends the data packet again to the target base station.
  • the user equipment before sending the second group of data packets to the target base station, the user equipment receives instruction information from the source base station, where the instruction information instructs the user equipment to send the second group of data packets to the target base station.
  • the indication information may be included in the RRC reconfiguration message.
  • the RRC message may be an RRC reconfiguration message carrying a synchronization reconfiguration information element (reconfiguration with sync) or may be an RRC connection reconfiguration message carrying a mobility control information element (mobility control info).
  • the above-mentioned indication information may be generated by the source base station and sent to the UE; the above-mentioned indication information may also be generated by the target base station and sent to the source base station, which is transparently transmitted to the UE by the source base station.
  • the target base station generates the above indication information, and the target base station When the base station sends the handover request confirmation message to the source base station, the message includes the indication information.
  • the indication information is transparently transmitted to the UE through the above RRC reconfiguration message.
  • Step 504 The target base station receives the second group of data packets from the user equipment.
  • Step 505 The source base station sends the first group of data packets to the core network device.
  • the third indexes respectively included in the data packets in the first group of data packets received by the source base station may be continuous or discontinuous.
  • the source base station can send all correctly received data packets to the core network device.
  • the source base station determines the first group according to the mapping relationship between the third index and the fourth index corresponding to the third index, for example, the mapping relationship between PDCP SN and GTP-U SN The fourth index respectively included in the header of the data packet in the data packet.
  • the source base station receives indication information from the UE, where the indication information instructs the source base station to send the first group of data packets to the UPF.
  • the indication information may be included in an RRC message, or a layer 1 message, or a layer 2 message, which is not limited in this embodiment.
  • the RRC message may be an RRC reconfiguration complete message, or may be another message, which is not limited in this embodiment.
  • the indication information may be included in downlink control information (DCI).
  • the indication information may be included in a media access control (MAC) control element (CE) message, which is not limited in this embodiment.
  • DCI downlink control information
  • CE media access control element
  • the indication information may be included in a header of the first backup data packet sent by the UE to the source base station, for example, the PDCP header includes the indication information.
  • Step 506 The target base station sends the second group of data packets to the core network device.
  • the target base station determines the second group according to the mapping relationship between the third index and the fourth index corresponding to the third index, for example, the mapping relationship between PDCP SN and GTP-U SN The fourth index respectively included in the header of the data packet in the data packet.
  • mapping relationship between the third index and the fourth index corresponding to the third index in step 506 is received from the source base station.
  • step 505 there is no strict time relationship between step 505 and step 506.
  • the above method further includes:
  • Step 507 The core network device receives the first group of data packets from the source base station.
  • Step 508 The core network device receives the second group of data packets from the target base station.
  • Step 509 The core network device performs operations such as repeated packet detection, reordering, and/or sequential delivery according to the fourth index included in all the data packets in the first group of data packets and the second group of data packets.
  • the UE Before the UE successfully switches to the target base station (the RRC connection between the UE and the target base station has not been successfully established), the UE sends data packets P1, P2, P3, P4, P5, P6, P7, and data packets P1 to P7 to the source base station
  • the PDCP SN is continuous and increasing.
  • the data packets P1, P2, P3, P6, P7 are correctly received by the source base station (the UE receives ACKs for the data packets P1, P2, P3, P6, P7 respectively), and the data packets P4, P5 are not correctly received by the source base station (For example, the UE does not receive the feedback of the source base station for the data packets P4 and P5, or the UE receives the feedback for the data packets P4 and P5 is NACK).
  • the UE After establishing an RRC connection with the target base station, the UE sends data packets P4 and P5 to the target base station.
  • the data packets P4 and P5 sent by the UE to the target base station respectively include respective corresponding third indexes, such as PDCP SN.
  • the target base station sends data packets P4, P5 to the core network device.
  • the data packets P4 and P5 sent by the target base station to the UPF respectively include respective corresponding fourth indexes, such as GTP-U SN.
  • the source base station sends data packets P1, P2, P3, P6, P7 to the core network device.
  • the data packets P1, P2, P3, P6, and P7 sent by the source base station to the core network device respectively include respective corresponding fourth indexes, such as GTP-U SN.
  • the UPF device performs operations such as repeated packet detection, reordering, and/or order delivery for all data packets P1 to P7 received from the source base station and the target base station according to the fourth index carried in the data packets P1 to P7.
  • the UE Before the UE successfully switches to the target base station (the RRC connection between the UE and the target base station has not been successfully established), the UE sends data packets P1, P2, P3, P4, P5, P6, P7, and data packets P1 to P7 to the source base station
  • the PDCP SN is continuous and increasing.
  • the data packets P1, P2, and P3 are correctly received by the source base station (for example, the UE receives ACKs for the data packets P1, P2, and P3 respectively), and the data packets P4, P5, P6, and P7 are not correctly received by the source base station (for example, , The UE does not receive the feedback for the data packets P4, P5, P6, and P7, or the UE receives the feedback for the data packets P4, P5, P6, and P7 respectively is NACK).
  • the UE After establishing an RRC connection with the target base station, the UE sends data packets P4, P5, P6, P7 to the target base station.
  • the data packets P4, P5, P6, and P7 sent by the UE to the target base station respectively include respective corresponding third indexes, such as PDCP SN.
  • the target base station sends data packets P4, P5, P6, P7 to the core network device.
  • the data packets P4, P5, P6, and P7 sent by the target base station to the core network device respectively include respective corresponding fourth indexes, such as GTP-U SN.
  • the source base station sends data packets P1, P2, P3 to the core network device.
  • the data packets P1, P2, and P3 sent by the source base station to the core network device respectively include respective corresponding fourth indexes, such as GTP-U SN.
  • the UPF device performs operations such as repeated packet detection, reordering, and/or order delivery for all data packets P1 to P7 received from the source base station and the target base station according to the fourth index carried in the data packets P1 to P7.
  • the UE Before the UE successfully switches to the target base station (the RRC connection between the UE and the target base station has not been successfully established), the UE sends data packets P1, P2, P3, P4, P5, P6, P7, and data packets P1 to P7 to the source base station
  • the PDCP SN is continuous and increasing.
  • the UE does not receive the ACKs for the data packets P1 to P7, or the UE receives the NACKs for the data packets P1 to P7).
  • the UE After establishing an RRC connection with the target base station, the UE sends data packets P1 to P7 to the target base station.
  • the data packets P1 to P7 sent by the UE to the target base station respectively include respective corresponding third indexes, such as PDCP SN.
  • the target base station sends data packets P1 to P7 to the core network device.
  • the data packets P1 to P7 sent by the target base station to the core network device respectively include respective corresponding fourth indexes, such as GTP-U SN.
  • the UPF device performs operations such as repeated packet detection, reordering, and/or sequential delivery of all data packets P1 to P7 received from the target base station according to the fourth index carried in the data packets P1 to P7.
  • the source base station when the source base station does not need to forward the UE's data packet to the target base station, the possibility of packet loss is reduced and the reliability of data transmission is improved.
  • the corresponding user plane protocol stack architecture may be as shown in FIG. 6.
  • the core network device such as a UPF device
  • the corresponding protocol stack includes physical (PHY) Layer (also called layer 1, L1)
  • layer 2 for example, layer 2 includes media access control (MAC) layer, radio link control (RLC) layer, and packet data aggregation layer Protocol (packet data convergence protocol, PDCP) layer, service data adaptation protocol (Service Data Adaptation Protocol, SDAP) layer, User Datagram Protocol/Internet (User Datagram Protocol/Internet Protocol, UDP/IP) layer, GTP-U layer ,
  • access network equipment such as the source base station or target base station
  • the corresponding protocol stack includes the physical layer (physical, PHY), layer 2 (for example, layer 2 includes media access Control (media access control, MAC) layer, radio link control (RLC) layer, packet data convergence protocol (PDCP) layer, service data adaptation protocol (Service Data ).
  • PHY Physical Layer
  • the UPF device needs to generate sequence numbers with QoS flow granularity for the backup data packets sent to the source base station and target base station.
  • QoS flow can be a data radio bearer (DRB) granularity Yes, that is, only one QoS flow can be mapped to the same DRB, and different QoS flows are mapped to different DRBs. Therefore, it can also be understood that for downlink transmission, the UPF device needs to target the backup data packets sent to the source base station and the target base station.
  • DRB data radio bearer
  • this function is realized by the GTP-U layer, for example, the GTP-U layer generates GTP-U SN; for uplink transmission, the UPF device processes the backup data packets received from the source base station and the target base station.
  • the sequence number of QoS flow granularity (or DRB granularity), for example, the GTP-U layer of the UPF device processes the GTP-U SN, and the GTP-U layer can perform operations such as repeated packet detection, reordering, and order delivery.
  • the source base station or the target base station for downlink transmission, it is necessary to process the sequence number of the QoS flow granularity (or DRB granularity) for the backup data packet received from the core network device; for the uplink transmission, the source base station or the target base station The base station generates a sequence number of QoS flow granularity (or DRB granularity) for the backup data packet received from the UE.
  • the source base station or the target base station receives the backup data packet sent by the UPF device, and the PDCP layer of the source base station determines the corresponding to the received backup data packet according to the GTP-U SN contained in the header of the backup data packet PDCP SN, and the source base station can determine the mapping relationship between GTP-U SN and PDCP SN, and the PDCP layer of the target base station can be based on the GTP-U SN contained in the header of the backup data packet, and the GTP-U SN and PDCP
  • the mapping relationship of SN (for example, the mapping relationship between GTP-U SN and PDCP SN sent by the target base station) determines the PDCP SN corresponding to the received backup data packet; for uplink transmission, the source base station or the target base station receives For the backup data packet sent by the UE, the source base station determines the GTP-U SN corresponding to the received backup data packet according to the PDCP SN contained in the header
  • the GTP-U SN can be determined by the protocol shown in Figure 6 Layer, that is, the GTP-U layer is generated, and the source base station can determine the mapping relationship between GTP-U SN and PDCP SN, and the target base station can be based on the PDCP SN contained in the header of the backup data packet, and the GTP-U SN and PDCP
  • the mapping relationship of SN (for example, the mapping relationship between GTP-U SN and PDCP SN sent by the target base station) determines the GTP-U SN corresponding to the received backup data packet.
  • GTP-U SN can be determined by GTP-U SN.
  • U layer is generated.
  • the UE needs to perform duplicate packet detection, reordering, and order delivery for the backup data packets received from the source base station and the target base station, for example, the PDCP layer of the UE performs duplicate packet detection , Reordering, and order delivery; for uplink transmission, the UE generates backup data packets and sends them to the source base station and the target base station respectively.
  • the PDCP layer of the UE can generate backup data packets.
  • the core network equipment such as UPF equipment
  • the corresponding protocol stack includes the PHY layer, layer 2 (for example, layer 2 includes the MAC layer, RLC layer, PDCP layer, SDAP layer), UDP/IP layer, and GTP-U layer , HRP layer, PDU layer
  • access network equipment such as source base station or target base station
  • the corresponding protocol stack includes PHY layer, layer 2 (for example, layer 2 includes MAC layer, RLC layer, PDCP layer, SDAP layer), UDP /IP layer, GTP-U layer, HRP layer
  • user equipment such as UE
  • the corresponding protocol stack includes PHY layer, layer 2 (for example, layer 2 includes MAC layer, RLC layer, PDCP layer, SDAP layer), PDU layer , Application layer.
  • a new layer (such as the HRP layer) is introduced above the GTP-U layer of the base station, which can generate/process QoS The sequence number of flow granularity (or DRB granularity).
  • the HRP layer of the base station can generate/process HRP SN; and, under the protocol stack architecture shown in Figure 7, a new GTP-U layer is introduced on top of the UPF device Layer (for example, HRP layer).
  • the HRP layer can generate/process sequence numbers of QoS flow granularity (or DRB granularity).
  • the HRP layer of the UPF device can generate/process HRP SN.
  • the UPF device needs to generate sequence numbers with QoS flow granularity (or DRB granularity) for the backup data packets sent to the source base station and the target base station.
  • This function is implemented by the HRP layer, such as the UPF device.
  • the HRP layer generates the HRP SN; for uplink transmission, the UPF device processes the sequence numbers of the QoS flow granularity (or DRB granularity) for the backup data packets received from the source base station and the target base station respectively.
  • the HRP layer of the UPF device processes the HRP SN
  • the HRP layer of the UPF device performs operations such as repeated packet detection, reordering, and order delivery according to the HRP SN contained in the packet header.
  • the source base station or the target base station needs to process the sequence number of the QoS flow granularity (or DRB granularity) for the backup data packet received from the core network device for the downlink transmission; for the uplink transmission, the source base station or the target base station The base station generates a sequence number of QoS flow granularity (or DRB granularity) for the backup data packet received from the UE.
  • the source base station or the target base station receives the backup data packet sent by the UPF device, and the PDCP layer of the source base station determines the PDCP SN corresponding to the received backup data packet according to the HRPSN contained in the header of the backup data packet , And the source base station can determine the mapping relationship between HRP SN and PDCP SN; the PDCP layer of the target base station can be based on the HRP SN contained in the header of the backup data packet, and the mapping relationship between HRP SN and PDCP SN (the target base station can learn from the source base station Receive the mapping relationship between HRP SN and PDCP SN) determine the PDCP SN corresponding to the received backup data packet; for uplink transmission, the source base station or the target base station receives the backup data packet sent by the UE, and the source base station uses the backup data packet header The included PDCP SN determines the HRP SN corresponding to the received backup data packet.
  • the sequence number can be generated by the HRP layer
  • the source base station can determine the mapping relationship between HRP SN and PDCP SN
  • the target base station can be based on the backup data
  • the PDCP SN contained in the packet header, and the mapping relationship between HRP SN and PDCP SN (the target base station can receive the mapping relationship between HRP SN and PDCP SN from the source base station) determine the HRP SN corresponding to the received backup data packet, such as this
  • the sequence number can be generated by the HRP layer.
  • the UE needs to perform repeated packet detection, reordering, and sequential delivery for the backup data packets received from the source base station and the target base station.
  • the PDCP layer of the UE can perform repeated packets Operations such as detection, reordering, and order delivery; for uplink transmission, the UE generates a backup data packet and sends it to the source base station and the target base station respectively.
  • the PDCP layer of the UE can generate the backup data packet.
  • the corresponding user plane protocol stack architecture can also be as shown in Figure 8.
  • the core network device such as the UPF device
  • the corresponding protocol stack includes the physical ( physical, PHY) layer
  • layer 2 includes media access control (MAC) layer, radio link control (RLC) layer, packet data convergence layer protocol (packet data convergence protocol) , PDCP) layer, Service Data Adaptation Protocol (SDAP) layer, User Datagram Protocol/Internet (User Datagram Protocol/Internet Protocol, UDP/IP) layer, GTP-U layer, HRP layer, protocol data Unit (Protocol Data Unit, PDU) layer
  • access network equipment such as source base station or target base station
  • the corresponding protocol stack includes the physical layer (physical, PHY), layer 2 (for example, layer 2 includes media access control (media access control (MAC) layer, radio link control (RLC) layer, packet data convergence protocol (PDCP) layer, service data adaptation protocol (Service Data Adaptation Protocol, SDAP) layer), User
  • MAC media access control
  • RLC radio link control
  • the UPF device needs to generate sequence numbers with QoS flow granularity for the backup packets sent to the source base station and target base station. Since QoS flow is DRB granular, only one QoS flow can be mapped to For the same DRB, different QoS flows are mapped to different DRBs. Therefore, it can also be understood that for downlink transmission, the UPF device needs to generate a sequence number with DRB granularity for the backup data packets sent to the source base station and the target base station.
  • the HRP layer For example, the HRP layer generates HRP SN; for uplink transmission, the UPF device processes the sequence number of the QoS flow granularity (or DRB granularity) for the backup data packets received from the source base station and the target base station respectively, for example, HRP
  • the layer processes HRP SN, and the HRP layer can perform operations such as duplicate packet detection, reordering, and order delivery.
  • the source base station sends the backup data packet received from the core network device to the user equipment.
  • the target base station may also receive the backup data from the core network device. The packet is sent to the user device.
  • the source base station sends the backup data packet received from the user equipment to the UPF device, and the target base station also sends the backup data packet received from the user equipment to the UPF device.
  • the HRP layer is transparent to the source base station (or target base station), that is, the base station does not need to process the sequence number of the QoS flow granularity (or DRB granularity), that is, for DL,
  • the base station does not need to process the HRP SN contained in the data packet received from the UPF device; corresponding to UL, the base station does not need to process the HRP SN contained in the data packet received from the UE.
  • the UE for user equipment, for downlink transmission, it is necessary for the UE to perform repeated packet detection, reordering, and sequential delivery for the backup data packets received from the source base station and the target base station, such as the UE’s
  • the HRP layer performs operations such as repeated packet detection, reordering, and order delivery; for uplink transmission, the UE generates backup data packets and sends them to the source base station and the target base station respectively.
  • the HRP layer of the UE performs data packet backup and the UE will backup the data packets
  • the headers of the backup data packets respectively sent to the source base station and the target base station, and the UE respectively send to the source base station and the target base station contain HRPSN.
  • the core network equipment such as UPF equipment
  • the corresponding protocol stack includes the PHY layer, layer 2 (for example, layer 2 includes the MAC layer, RLC layer, PDCP layer, SDAP layer), UDP/IP layer, and GTP-U layer , HRP layer, PDU layer
  • access network equipment such as source base station or target base station
  • the corresponding protocol stack includes PHY layer, layer 2 (for example, layer 2 includes MAC layer, RLC layer, PDCP layer, SDAP layer), UDP /IP layer, GTP-U layer, HRP layer
  • user equipment such as UE
  • the corresponding protocol stack includes PHY layer, layer 2 (for example, layer 2 includes MAC layer, RLC layer, PDCP layer, SDAP layer), HRP layer , PDU layer, application layer.
  • a new layer (such as the HRP layer) is introduced above the GTP-U layer of the base station, which can generate/process QoS Number of flow granularity (or DRB granularity), for example, the HRP layer of the base station can generate/process HRP SN.
  • the UPF device needs to generate sequence numbers with QoS flow granularity (or DRB granularity) for the backup data packets sent to the source base station and target base station.
  • This function can be implemented by the HRP layer and/or GTP- U-layer implementation, for example, the GTP-U SN in the GTP-U header of the backup data packet sent by the UPF device to the source base station and the target base station respectively, and/or the backup data packet sent by the UPF device to the source base station and the target base station respectively
  • the HRP header contains the HRP SN; for uplink transmission, the UPF device processes the sequence number of the QoS flow granularity (or DRB granularity) for the backup data packets received from the source base station and the target base station, for example, the HRP layer processing of the UPF device HRP SN, and the HRP layer can perform operations such as repeated packet detection, reordering, and order delivery according to HRP SN; or, for uplink transmission, the
  • the source base station or the target base station for downlink transmission, it is necessary to process the sequence number of the QoS flow granularity (or DRB granularity) for the backup data packet received from the core network device; for the uplink transmission, the source base station or the target base station The base station generates a sequence number of QoS flow granularity (or DRB granularity) for the backup data packet received from the UE. Specifically, for downlink transmission, the source base station or the target base station receives the backup data packet sent by the UPF device.
  • the PDCP layer of the source base station determines the received backup according to the HRP SN contained in the header of the backup data packet
  • the PDCP SN corresponding to the data packet, and the source base station can determine the mapping relationship between HRP SN and PDCP SN, or, in another implementation, the PDCP layer of the source base station is based on the GTP-U SN contained in the header of the backup data packet.
  • the source base station can determine the mapping relationship between GTP-U SN and PDCP SN; in one implementation, the PDCP layer of the target base station can be based on the backup data packet The HRP SN contained in the header, and the mapping relationship between HRP SN and PDCP SN (the target base station can receive the mapping relationship between HRP SN and PDCP SN from the source base station) to determine the PDCP SN corresponding to the received backup packet, or another In this implementation, the PDCP layer of the target base station is based on the GTP-U SN contained in the header of the backup data packet, and the mapping relationship between GTP-U SN and PDCP SN (the target base station can receive GTP-U SN and PDCP SN from the source base station Mapping relationship) to determine the PDCP SN corresponding to the received backup data packet; for uplink transmission, the source base station or the target base station receives the backup data packet sent by the
  • the source base station is based on the backup data packet header
  • the included PDCP SN determines the HRP SN corresponding to the received backup data packet, and the source base station can determine the mapping relationship between HRP SN and PDCP SN, or, in another implementation manner, the source base station determines the HRP SN corresponding to the backup packet header
  • the PDCP SN contained in it determines the GTP-U SN corresponding to the received backup data packet, and the source base station can determine the mapping relationship between GTP-U SN and PDCP SN; in one implementation, the target base station can be based on the backup data
  • the PDCP SN contained in the packet header and the mapping relationship between HRP SN and PDCP SN (the target base station can receive the mapping relationship between HRP SN and PDCP SN from the source base station) to determine the HRP SN corresponding to the received backup data packet, or, In another implementation manner, the target base station can be based on the PDCP SN contained in the header of the backup
  • the UE needs to perform repeated packet detection, reordering, and sequential delivery for the backup data packets received from the source base station and the target base station.
  • the UE's HRP The layer performs operations such as repeated packet detection, reordering, and order delivery, or, in another implementation, the PDCP layer of the UE performs operations such as duplicate packet detection, reordering, and order delivery; for uplink transmission, the UE generates backup data Packets are sent to the source base station and the target base station respectively.
  • the HRP layer of the UE performs data packet backup and the UE sends the backup data packets to the source base station and the target base station.
  • the UE sends the headers of the backup data packets to the source base station and the target base station. Both include HRP SN.
  • solutions of the foregoing embodiments can be applied to a communication system alone, or two solutions or a combination of multiple solutions can be applied to a communication system.
  • the embodiment of the present application also provides a corresponding communication device (sometimes referred to as a communication device), and the communication device includes a module for executing each part of the foregoing embodiment. Or unit.
  • the module or unit may be software or hardware, or a combination of software and hardware.
  • FIG. 10 shows a schematic structural diagram of a base station, which can be applied to the system shown in FIG. 1.
  • the base station can be the source base station of the UE and/or the target base station of the UE.
  • the base station includes one or more remote radio units (RRU) 701 and one or more baseband units (BBU) 702.
  • the RRU 701 may be called a transceiver unit, a transceiver, a transceiver circuit or a transceiver, etc., and it may include at least one antenna 7011 and a radio frequency unit 7012.
  • the RRU701 sub is mainly used for receiving and sending of radio frequency signals and conversion of radio frequency signals and baseband signals, for example, for sending the signaling instructions or reference signals in the foregoing embodiments to the terminal.
  • the BBU702 part is mainly used for baseband processing and control of the base station.
  • the RRU701 and the BBU702 may be physically set up together or physically separated, that is, a distributed base station
  • the BBU702 is the control center of the base station, which can also be called a processing unit, and is mainly used to complete baseband processing functions, such as channel coding, multiplexing, modulation, and spreading.
  • the BBU702 can be composed of one or more single boards, and multiple single boards can jointly support a single access standard radio access network (such as a 5G network), or can separately support wireless access of different access standards network.
  • the BBU702 also includes a memory 7021 and a processor 7022.
  • the memory 7021 is used to store necessary instructions and data.
  • the processor 7022 is used to control the base station to perform necessary actions.
  • the memory 7021 and the processor 7022 may serve one or more single boards. In other words, the memory and the processor can be set separately on each board. It can also be that multiple boards share the same memory and processor. In addition, there are necessary circuits on each board.
  • the foregoing base station may be used to implement the method of the foregoing method embodiment, for example, may implement the function of the source base station or the target base station in the foregoing method embodiment.
  • the base station may include one or more processors, and the processors may also be referred to as processing units, which may implement certain control functions.
  • the processor may be a general-purpose processor or a special-purpose processor. For example, it can be a baseband processor or a central processing unit.
  • the baseband processor can be used to process communication protocols and communication data
  • the central processor can be used to process communication devices (such as base stations, baseband chips, distributed units (DU) or centralized units (CU)), etc. ) Control, execute the software program, and process the data of the software program.
  • the processor stores instructions, and the instructions can be executed by the processor to enable the base station to execute the method described in the foregoing method embodiment.
  • the base station includes one or more memories, on which instructions or codes are stored, and the instructions or codes can be executed on the processor, so that the base station executes the foregoing method embodiments Method described in.
  • data may also be stored in the memory.
  • instructions and/or data may also be stored in the processor.
  • the processor and memory can be provided separately or integrated together.
  • the base station includes a circuit, and the circuit can implement the sending or receiving or communication function in the foregoing method embodiment.
  • an embodiment of the present invention provides a target base station, as shown in FIG. 11, including:
  • the receiving unit 1101 is configured to receive a handover request message from the source base station;
  • the sending unit 1102 is configured to send a request message to the first core network device in response to the handover request message to request a copy of the first data packet, where the first data packet is sent by the second core network device to the source base station.
  • the data packet for the user equipment UE wherein the first core network device and the second core network device are the same core network device or different core network devices.
  • the receiving unit is further configured to receive a confirmation message of the request message; the sending unit is further configured to send a handover request confirmation message to the source base station.
  • the receiving unit is configured to receive a copy of the first data packet from the second core network device.
  • the sending unit is further configured to send a third data packet to the UE in response to the first data packet.
  • the sending unit is further configured to send a fourth data packet to the UE in response to a copy of the first data packet.
  • the first data packet and the copy of the first data packet respectively include a first index.
  • the third data packet and the fourth data packet respectively include a second index.
  • the receiving unit or the sending unit in this embodiment may be composed of multiple sub-units, which are respectively used to receive or send different data or signaling.
  • Figure 12 provides a schematic structural diagram of a terminal.
  • the terminal can be applied to the system shown in Figure 1.
  • FIG. 12 only shows the main components of the terminal.
  • the terminal 10 includes a processor, a memory, a control circuit or antenna, and an input and output device.
  • the processor is mainly used to process the communication protocol and communication data, and to control the entire terminal, execute the software program, and process the data of the software program.
  • the memory is mainly used to store software programs and data, for example, to store the codebook described in the above embodiments.
  • the control circuit is mainly used for the conversion of baseband signals and radio frequency signals and the processing of radio frequency signals.
  • the control circuit and the antenna together can also be called a transceiver, which is mainly used to send and receive radio frequency signals in the form of electromagnetic waves.
  • Input and output devices such as touch screens, display screens, or keyboards, are mainly used to receive data input by users and output data to users.
  • the processor can read the software program in the storage unit, interpret and execute the instructions of the software program, and process the data of the software program.
  • the processor performs baseband processing on the data to be sent and outputs the baseband signal to the radio frequency circuit.
  • the radio frequency circuit performs radio frequency processing on the baseband signal and then sends the radio frequency signal to the outside in the form of electromagnetic waves through the antenna.
  • the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor, and the processor converts the baseband signal into data and processes the data.
  • FIG. 12 only shows a memory and a processor. In an actual terminal, there may be multiple processors and memories.
  • the memory may also be referred to as a storage medium or a storage device, which is not limited in the embodiment of the present invention.
  • the processor may include a baseband processor and a central processing unit.
  • the baseband processor is mainly used to process communication protocols and communication data.
  • the central processing unit is mainly used to control the entire terminal and execute software. Programs, which process the data of software programs.
  • the processor in FIG. 12 integrates the functions of the baseband processor and the central processing unit.
  • the baseband processor and the central processing unit may also be independent processors and are interconnected by technologies such as buses.
  • the terminal may include multiple baseband processors to adapt to different network standards, the terminal may include multiple central processors to enhance its processing capabilities, and various components of the terminal may be connected through various buses.
  • the baseband processor can also be expressed as a baseband processing circuit or a baseband processing chip.
  • the central processing unit can also be expressed as a central processing circuit or a central processing chip.
  • the function of processing the communication protocol and communication data can be built in the processor, or can be stored in the storage unit in the form of a software program, and the processor executes the software program to realize the baseband processing function.
  • an antenna and a control circuit with a transceiving function can be regarded as the transceiving unit 801 of the terminal 10, and a processor with a processing function can be regarded as the processing unit 802 of the terminal 10.
  • the terminal 10 includes a transceiver unit 801 and a processing unit 802.
  • the transceiving unit may also be referred to as a transceiver, transceiver, or transceiving device.
  • the device for implementing the receiving function in the transceiver unit 801 can be regarded as the receiving unit, and the device for implementing the sending function in the transceiver unit 801 can be regarded as the sending unit, that is, the transceiver unit 801 includes a receiving unit and a sending unit.
  • the receiving unit may also be called a receiver, a receiver, or a receiving circuit
  • the sending unit may be called a transmitter, a transmitter, or a transmitting circuit, etc.
  • the foregoing user equipment may be used to implement the method in the foregoing embodiment.
  • the communication device is described by taking a base station or a terminal device as an example, the scope of the communication device described in this application is not limited to this, and the structure of the communication device may not be limited.
  • the communication device may be a stand-alone device or may be part of a larger device.
  • the device can be: an independent integrated circuit IC, or chip, or, a chip system or subsystem; a collection of one or more ICs; an application specific integrated circuit ASIC, such as a modem; it can be embedded in other devices Modules, etc.
  • an embodiment of the present invention provides a user equipment UE, as shown in FIG. 13, including:
  • the sending unit 1301 is used to send data packets P1, P2...PN to the source base station;
  • the sending unit is further configured to send data packets Pi to PN to the target base station, where the data packet Pi is the first data packet in the data packets P1 to PN that has not been correctly received by the source base station, and N is greater than or equal to 1.
  • An integer, i is an integer greater than or equal to 1 and less than or equal to N.
  • the indexes of the data packets P1 to PN are continuous and increasing.
  • the UE further includes a receiving unit 1302, configured to receive indication information from the source base station before the sending unit sends Pi to PN to the target base station, where the indication information indicates the UE Send data packets Pi to PN to the target base station.
  • a receiving unit 1302 configured to receive indication information from the source base station before the sending unit sends Pi to PN to the target base station, where the indication information indicates the UE Send data packets Pi to PN to the target base station.
  • the indication information is included in a radio resource control RRC reconfiguration message.
  • the UE further includes a processing unit 1303, configured to, before the sending unit sends the data packets Pi to PN to the target base station, if the UE does not receive the target from the source base station The response of the data packet Pi, or a negative acknowledgement NACK for the data packet Pi from the source base station is received, and the acknowledgement ACK of the data packet before Pi in the data packets P1 to PN is received, then It is determined that the data packet Pi is the first data packet among the data packets P1 to PN that has not been correctly received by the source base station.
  • the receiving unit or the sending unit in this embodiment may be composed of multiple sub-units, which are respectively used to receive or send different data or signaling.
  • an embodiment of the present invention also provides a communication system, including a source base station and a target base station:
  • the source base station is configured to receive a first data packet from a core network device
  • the target base station is configured to receive a second data packet from the core network device, the second data packet is a copy of the first data packet, and the first data packet and the second data packet respectively include First index
  • the source base station is further configured to send first indication information to the target base station, where the first indication information indicates the mapping relationship between the first index and the second index;
  • the source base station is further configured to send a third data packet to user equipment UE in response to the first data packet;
  • the target base station is further configured to send a fourth data packet to the UE in response to the second data packet, where the third data packet and the fourth data packet respectively include the second index.
  • the source base station is further configured to receive second indication information from the core network device;
  • the source base station is further configured to determine the mapping relationship between the first index and the second index according to the first index in response to the second indication information.
  • the second indication information is included in the first data packet.
  • the source base station is further configured to receive a fifth data packet from the UE;
  • the target base station is further configured to receive a sixth data packet from the UE, where the sixth data is a copy of the fifth data packet, and the fifth data packet and the sixth data packet respectively include Third index
  • the source base station is further configured to send a seventh data packet to the core network device in response to the fifth data packet;
  • the target base station is further configured to send an eighth data packet to the core network device corresponding to the sixth data packet, where the seventh data packet and the eighth data packet respectively include a fourth index.
  • the source base station is further configured to send third indication information to the target base station, where the third indication information indicates the mapping relationship between the third index and the fourth index.
  • the source base station is further configured to receive fourth indication information from the UE;
  • the source base station is further configured to determine the mapping relationship between the third index and the fourth index according to the third index in response to the fourth indication information.
  • the fourth indication information is included in the fifth data packet.
  • the embodiment of the present invention also provides a communication system, including a source base station and a target base station:
  • the target base station is configured to receive data packets Pi to PN from the user equipment, and the data packet Pi is the data packets P1 to PN sent by the user equipment to the source base station that have not been correctly received by the source base station
  • N is an integer greater than or equal to 1
  • i is an integer greater than or equal to 1 and less than or equal to N;
  • the target base station is also used to send data packets Pi to PN to the core network device;
  • the source base station is configured to send data packets before the data packet Pi in the data packets P1 to PN to the core network device.
  • the indexes of the data packets P1 to PN are continuous and increasing.
  • the target base station before the target base station receives the data packets Pi to PN, the target base station is further configured to send instruction information to the source base station, and the instruction information instructs the user equipment to send the user equipment to the target base station. Send the data packet Pi to PN.
  • the embodiment of the present invention also provides another communication system, including a source base station and a target base station:
  • the source base station is configured to receive a first group of data packets from user equipment
  • the target base station is configured to receive a second group of data packets from the user equipment, where the first group of data packets is correctly received by the source base station among data packets sent by the user equipment to the source base station
  • the second group of data packets is a retransmission data packet of a data packet that has not been correctly received by the source base station among the data packets sent by the user equipment to the source base station;
  • the source base station is further configured to send the first group of data packets to a core network device
  • the target base station is further configured to send the second group of data packets to the core network device.
  • the first group of data packets are data packets with discontinuous indexes.
  • the embodiment of the present invention also provides a core network device for realizing the function of the core network device in the foregoing method embodiment.
  • the core network device provided by the embodiment of the present invention may be composed of multiple devices.
  • the core network equipment may include a memory, a processor, a transceiver circuit, and so on.
  • the computer program product includes one or more computer instructions.
  • the computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.
  • the computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, computer, server, or data center.
  • the computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or a data center integrated with one or more available media.
  • the usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid state disk (SSD)).

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Abstract

本申请提供了一种无线通信系统中的切换方法、装置及系统。源基站接收来自于核心网设备的第一数据包；目标基站接收来自于所述核心网设备的第二数据包，所述第二数据包是所述第一数据包的副本，所述第一数据包与所述第二数据包分别包括第一索引；所述源基站向所述目标基站发送第一指示信息，所述第一指示信息指示所述第一索引与第二索引的映射关系；所述源基站，响应于所述第一数据包，向用户设备UE发送第三数据包；所述目标基站，响应于所述第二数据包，向所述UE发送第四数据包，所述第三数据包和所述第四数据包分别包括所述第二索引。

Description

无线通信系统中的切换方法、装置及系统
本申请要求于2019年02月15日提交中国专利局、申请号为201910118135.0、申请名称为“无线通信系统中的切换方法、装置及系统”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及通信技术领域，尤其涉及无线通信系统中的切换方法、装置及系统。
背景技术
在移动通信系统中，随着用户设备(User Equipment，UE)的移动，网络通过切换过程将用户设备从源小区切换到目标小区进行数据传输，源基站在空口向用户设备发送用于切换的命令后，停止对用户设备进行上下行数据传输，然后，源基站给目标基站发送序列号状态转移(sequence number status transfer)消息并将数据包转发(data forwarding)到目标基站，例如，对于上行，源基站将接收到的乱序的上行数据包(从第一个乱序的UL数据包开始，以及第一个乱序包之后的其他所有数据包(若存在的话))转发给目标基站；对于下行，源基站将已经发送给用户设备但是没有被用户设备确认成功接收的下行数据包，以及核心网新来的数据包转发给目标基站。切换前后，对于同一份承载/业务，用户设备在源基站无法完成的数据传输，在用户设备成功切到目标基站后，继续在目标基站完成。
在上述的切换过程中，源基站与目标基站的数据包转发会引起时延，尤其当基站间的回传不理想时，时延较大，降低了用户对时延敏感业务的体验。因此，如何减少数据转发造成的时延是需要解决的问题。
发明内容
本申请提供了一种信息传输方法、装置及系统，可以降低数据传输的时延。
一方面，提供了一种通信方法，相应的通信装置，以及通信系统。
用户设备UE的源基站接收来自于核心网设备的第一数据包；UE的目标基站接收来自于所述核心网设备的第二数据包，所述第二数据包是所述第一数据包的副本，所述第一数据包与所述第二数据包分别包括第一索引；所述源基站向所述目标基站发送第一指示信息，所述第一指示信息指示所述第一索引与第二索引的映射关系；所述源基站，响应于所述第一数据包，向用户设备UE发送第三数据包；所述目标基站，响应于所述第二数据包，向所述UE发送第四数据包，所述第三数据包和所述第四数据包分别包括所述第二索引。
上述方案中，源基站与目标基站使用的映射关系是相同的，使得UE能够正确的 接收来自源基站以及目标基站的数据包，从而利于UE正确地进行重复包检测或数据包重排序或按序递交。
所述第二数据包与所述第一数据包至少包括相同的有效负荷(payload)。
可选的，所述方法还包括：所述核心网设备向所述源基站发送第二指示信息。源基站接收到所述第二指示信息，确定所述第一索引与所述第二索引的映射关系。所述第二指示信息可以包括在所述第一数据包内，或者该第二指示信息由所述核心网设备携带在单独的消息中通知所述源基站。
在一种可能的实现方式中，所述方法还包括：所述源基站接收来自于所述UE的第五数据包，并响应于所述第五数据包，向所述核心网设备发送第七数据包。所述目标基站接收来自于所述UE的第六数据包，并响应于所述第六数据包，向所述核心网设备发送第八数据包。所述第六数据是所述第五数据包的副本。所述第五数据包与所述第六数据包分别包括第三索引。所述第七数据包与所述第八数据包分别包括第四索引。
一种可能的实现方式中，所述第五数据包和第六数据包至少包括相同的有效payload，且使用相同的索引，从而使得来自UE的数据包被网络侧正确接收，以保障UE切换过程中的正常通信。
可选的，所述源基站向所述目标基站发送第三指示信息，所述第三指示信息指示所述第三索引与所述第四索引的映射关系。因此，目标基站和目标基站，可以使用相同的索引向核心网设备发送用于所述UE的数据包，从而保障了在UE切换过程中，来自UE的数据被正确接收。
上述方案中，由于源基站与目标基站使用的映射关系是相同的，保证了核心网设备能够对分别从源基站以及目标基站正确接收来自UE的数据，从而利于UE进行重复包检测、数据包重排序、或按序递交等操作。
可选的，UE向所述源基站发送第四指示信息。所述源基站根据所述指示信息确定所述第三索引与所述第四索引的映射关系。所述第四指示信息包括在所述第五数据包内，或者UE通过其他的消息携带。
在一种实现方式中，所述第一指示信息包括所述第一索引的值以及与所述第一索引对应的所述第二索引的值。在另一种可能的实现方式中，所述第一指示信息包括所述第一索引和与所述第一索引对应的所述第二索引的映射公式。在又一种可能的实现方式中，所述第一指示信息包括所述第一索引的值和与所述第一索引对应的所述第二索引的值的差值。
另一方面，提供了一种通信方法，相应的通信装置，以及通信系统。
用户设备UE的目标基站接收来自于UE的源基站的切换请求消息，所述目标基站，响应于所述切换请求消息向第一核心网设备发送请求消息，以请求第一数据包的副本，所述第一数据包为第二核心网设备向所述源基站发送的用于用户设备UE的数据包。其中所述第一核心网设备与所述第二核心网设备是相同的核心网设备，或者是不同的核心网设备。
可选的，所述目标基站从所述第一核心网设备接收针对所述请求消息的确认消息。
可选的，所述目标基站还向所述源基站发送切换请求确认消息。
上述方案中，源基站与目标基站之间进行切换过程中，例如，在切换准备的同时，目标基站与核心网设备之间进行传输通道的建立，尽快启用duplication流程，进而，在UE与源基站之间的链路质量恶化前，即将目标基站与核心网设备之间的用于传输备份数据包的通道建立成功，保证了数据传输的可靠性。
所述目标基站接收来自于所述第二核心网设备的所述第一数据包的副本。例如，所述第一数据包的副本可以由第二核心网设备发送给所述目标基站，或者由所述第一核心网设备转发给所述目标基站。
一种可能的实现方式中，所述源基站，响应于所述第一数据包向所述UE发送第三数据包。和所述第一数据包的副本分别包括第一索引。所述目标基站，响应于所述第一数据包的副本向所述UE发送第四数据包。所述第三数据包和所述第四数据包分别包括第二索引。
相应的，还提供了一种通信装置，该通信装置可以是基站，其作为UE的目标基站。该通信装置也可以是作为UE的目标基站中的设备，例如通信芯片等。所述通信装置包括发送单元和接收单元。所述发送单元和接收单元分别实现上述方法中的发送功能及实现功能。所述发送单元可以是发射器、发射机，发送电路、输出电路、通信芯片的接口或者其他认可可实现发送功能的手段(means)。所述接收单元可以是基站的接收器、接收机、接收电路、输入电路、通信芯片的接口、或者是其他任何可实现接收功能的手段(means)。，在一种可能的实现方式中，所述接收单元，用于接收来自于源基站的切换请求消息。所述发送单元，用于响应于所述切换请求消息向第一核心网设备发送请求消息，以请求第一数据包的副本，所述第一数据包为第二核心网设备向所述源基站发送的用于用户设备UE的数据包，其中所述第一核心网设备与所述第二核心网设备是相同的核心网设备，或者是不同的核心网设备。
又一方面，提供了一种通信方法、相应的通信装置及系统。
用户设备UE向源基站发送数据包P 1，P 2……P N。UE向目标基站发送数据包P i至P N，其中数据包P i为数据包P 1至P N中未被所述源基站正确接收的第一个数据包，N为大于等于1的整数，i为大于等于1且小于等于N的整数。所述目标基站接收来自于所述用户设备的数据包P i至P N，并向核心网设备发送数据包P i至P N。所述源基站向所述核心网设备发送所述数据包P 1至P N中所述数据包P i之前的数据包。
UE通过向目标基站发送第一个未被正确接收的数据包及之后的数据包，可以降低丢包可能性，提高数据传输可靠性。
所述数据包P 1至P N的索引是连续且递增的、或者连续递减的、或者是按照预定的规则排列的
可选的，所述UE在向所述目标基站发送P i至P N之前，接收来自于所述源基站的指示信息，所述指示信息指示所述UE向所述目标基站发送数据包P i至P N。例如，该指示信息包括在无线资源控制RRC重配置消息中、或者其他的消息中。
可选的，在所述UE向所述目标基站发送所述数据包P i至P N之前，UE确定未被源基站正确接收的数据包、或者未被源基站正确接收的第一个数据包。如果所述UE未收到来自于所述源基站的针对所述数据包P i的响应，或者接收到来自于所述源基站的针对所述数据包P i的否定确认NACK，且接收到所述数据包P 1至P N中P i之前的数 据包的确认ACK，则所述UE确定所述数据包P i为所述数据包P 1至P N中未被所述源基站正确接收的第一个数据包。
相应的，还提供了一种通信装置及通信系统。所述通信装置可以是用户设备UE，或用于用户设备的通信芯片。该通信装置包括发送单元用以实现上述方法中的发送功能。例如所述发送单元用于分别向源基站发送数据包P 1，P 2……P N，向目标基站发送数据包P i至P N，其中数据包P i为数据包P 1至P N中未被所述源基站正确接收的第一个数据包，N为大于等于1的整数，i为大于等于1且小于等于N的整数。所述发送单元可以是发射器、发射机，发送电路、输出电路、通信芯片的接口或者其他认可可实现发送功能的手段(means)。
所述处理装置还包括处理单元，用于确定所发送的数据包是否被正确接收。例如所述处理单元确定未被源基站正确接收的数据包、或者未被源基站正确接收的第一个数据包。如果所述通信装置未收到来自于所述源基站的针对所述数据包P i的响应，或者接收到来自于所述源基站的针对所述数据包P i的否定确认NACK，且接收到所述数据包P 1至P N中P i之前的数据包的确认ACK，则确定所述数据包P i为所述数据包P 1至P N中未被所述源基站正确接收的第一个数据包。
相应的，还提供了一种通信装置，该通信装置为基站，其可以作为UE的源基站，和/或目标基站。或者该通信装置是作为UE的源基站和/或目标基站中的设备，例如通信芯片等。所述通信装置包括发送单元和接收单元。所述发送单元和接收单元分别实现上述方法中的发送功能及实现功能。所述发送单元可以是发射器、发射机，发送电路、输出电路、通信芯片的接口或者其他认可可实现发送功能的手段(means)。所述接收单元可以是基站的接收器、接收机、接收电路、输入电路、通信芯片的接口、或者是其他任何可实现接收功能的手段(means)。
相应的，还提供了一种通信系统，包括源基站和目标基站：
所述目标基站，用于接收来自于所述用户设备的数据包P i至P N，所述数据包P i为用户设备向源基站发送的数据包P 1至P N中，未被所述源基站正确接收的第一个数据包，N为大于等于1的整数，i为大于等于1且小于等于N的整数；
所述目标基站，还用于向核心网设备发送数据包P i至P N；
所述源基站，用于向所述核心网设备发送所述数据包P 1至P N中所述数据包P i之前的数据包。
上述上行传输方案，降低了丢包可能性，提高了数据传输可靠性。
可选的，在所述目标基站接收所述数据包P i至P N之前，所述目标基站，还用于向所述源基站发送指示信息，所述指示信息指示所述用户设备向所述目标基站发送所述数据包P i至P N。
再一方面，提供了一种通信方法、通信装置及通信系统。源基站接收来自于用户设备的第一组数据包，以及向核心网设备发送所述第一组数据包。目标基站接收来自于所述用户设备的第二组数据包，以及向所述核心网设备发送所述第二组数据包。其中，所述第一组数据包为所述用户设备向所述源基站发送的数据包中被所述源基站正确接收的数据包，第二组数据包是所述用户设备向所述源基站发送的所述数据包中未被所述源基站正确接收的数据包的重传数据包；
该通信方法可以降低丢包可能性，提高数据传输可靠性。
一种可能的实现方式中，所述第一组数据包为索引不连续的数据包。
上述各方面所述的通信装置中的单元可以通过软件、或者硬件、或者软硬结合来实现。
在一种可能的实现方式中，上述各方面所述的通信装置，包括一个或多个处理器，以及一个或多个存储器，所述存储器上存储有可被所述一个或多个处理器执行的指令或代理，当所述指令或代码被运行使得所述通信装置执行上述各方面所述的方法。
本申请的又一方面提供了一种计算机可读存储介质，所述计算机可读存储介质中存储有指令，当其在计算机上运行时，使得计算机执行上述各方面所述的方法。
本申请的又一方面提供了一种包含指令的计算机程序产品，当其在计算机上运行时，使得计算机执行上述各方面所述的方法。
附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍。
图1为实现本发明实施例的一种可能的系统结构示意图；
图2为本发明实施例提供的一种通信方法流程图；
图2a为本发明实施例提供的一种通信方法流程图；
图3为本发明实施例提供的另一种通信方法流程图；
图4为本发明实施例提供的一种上行数据传输方法流程图；
图5为本发明实施例提供的另一种上行数据传输方法流程图；
图6为本发明实施例提供的一种协议栈示意图；
图7为本发明实施例提供的另一种协议栈示意图；
图8为本发明实施例提供的另一种协议栈示意图；
图9为本发明实施例提供的另一种协议栈示意图；
图10为本发明实施例提供的一种基站的结构示意图；
图11为本发明实施例提供的另一种基站的结构示意图；
图12为本发明实施例提供的一种用户设备的结构示意图；
图13为本发明实施例提供的另一种用户设备的结构示意图；
具体实施方式
下面结合附图，对本发明提供的实施例做详细说明。本发明实施例描述的网络架构以及业务场景是为了更加清楚的说明本发明实施例的技术方案，并不构成对于本发明实施例提供的技术方案的限定，本领域普通技术人员可知，随着网络架构的演变和新业务场景的出现，本发明实施例提供的技术方案对于类似的技术问题，同样适用。
图1示出了本申请的一种可能的系统网络示意图。如图1所示，至少一个终端10与无线接入网(Radio access network,RAN)进行通信。所述RAN至少包括两个基站：基站20和基站30，图中只示出两个基站和一个用户设备UE。所述RAN与核心网络 (core network,CN)相连。所述核心网络包括一个或多个核心网设备。可选的，所述CN可以耦合到一个或者更多的外部网络(External Network)，例如英特网Internet，公共交换电话网(public switched telephone network，PSTN)等。其中，UE在移动过程中，与无线接入网的连接可以由基站20切换至基站30，此时，基站20可以称为源基站，基站30可以称为目标基站。
为便于理解下面对本申请中涉及到的一些名词做些说明。
本申请中，名词“网络”和“系统”经常交替使用。但本领域的技术人员可以理解其含义。本申请中所描述的通信装置是指的通信系统中的网元，例如终端、基站(源基站、或目标基站)、核心网设备。
所述终端，有时也叫用户设备(User Equipment，UE)。UE是一种具有通信功能的终端设备，也可以称为终端，可以包括具有无线通信功能的手持设备、车载设备、可穿戴设备、计算设备或连接到无线调制解调器的其它处理设备等。在不同的网络中用户设备可以叫做不同的名称，例如：终端，移动台，用户单元，站台，蜂窝电话，个人数字助理，无线调制解调器，无线通信设备，手持设备，膝上型电脑，无绳电话，无线本地环路台等。为描述方便，本申请中简称为用户设备UE或终端。
所述基站(base station,BS)可以是云网络中的无线接入设备或中继站等具有无线收发功能的设备。基站也可称为基站设备，是一种部署在无线接入网用以提供无线通信功能的网络设备。在不同的无线接入系统中基站的名称可能有所不同，例如在而在通用移动通讯系统(Universal Mobile Telecommunications System，UMTS)网络中基站称为节点B(NodeB),在LTE网络中的基站称为演进的节点B(evolved NodeB，eNB或者eNodeB)，在5G系统中可以称为收发节点(Transmission Reception Point，TRP)、g节点B(gNodeB，gNB)。基站可以包含一个或多个共站或非共站的TRP。基站还可以是云无线接入网络(cloud radio access network，CRAN)场景下的无线控制器、集中单元(centralized unit，CU)，和/或分布单元(distributed unit,DU)。基站还可以是是服务器，可穿戴设备，或车载设备等。为描述方便，下文使用基站进行描述。可选的，本发明中的基站还可以是设备到设备D2D(Device to Device)中的用户设备。可选的，本发明中的基站和用户设备还可以是中继设备，或实现中继功能的网络设备或用户设备。
下文以5G网络为例，对本发明实施例提供的方案进行描述，但本发明的方案并不限于5G网络，例如本发明的方案还可以适用于LTE，或者后续演进网络，或者多种融合网络等，本发明实施例对此不作限定。
实施例一
本实施例提供了一种通信方法，装置及系统。该方案可以应用于图1所示的系统。如图2所示：
步骤201、源基站向目标基站发送切换请求消息。
本实施例中，源基站确定需要将UE由源基站切换至目标基站时，向目标基站发送切换请求消息，请求将UE切换至目标基站。
步骤202、目标基站，响应于所述切换请求消息，向第一核心网设备发送请求消 息，以请求第一数据包的副本，所述第一数据包为第二核心网设备向所述源基站发送的用于用户设备UE的数据包。
可选的，第一核心网设备可以是接入和移动管理功能(Access and Mobility Management Function，AMF)设备，第二核心网设备可以是用户面功能(User Plane Function，UPF)设备。
本发明实施例中可选的，所述第一核心网设备与所述第二核心网设备可以是相同的核心网设备，或者是不同的核心网设备。
为描述方便，本申请中对“核心网设备”功能进行描述，所述第一核心网设备或第二核心网设备可以包括核心网设备的功能，除非有特别说明。
上述请求消息例如可以是备份请求(duplication request)消息，或者该请求消息有其他表示、命名方式，对此不作限定。
在一些场景下，所述目标基站发送请求消息，例如duplication request，也可以理解为，请求核心网设备向所述源基站发送所述第一数据包，且请求所述核心网设备向所述目标基站发送所述第一数据包的副本。
所述第一数据包的副本可以称为第二数据包。所述第一数据包和所述第二数据包，至少有效负载(payload)是相同的。所述第一数据包和所述第二数据包的内容可以完全相同，或者不完全相同(例如有效负载相同，其他信息不同)。
可选的，核心网设备可以包括以下一个或多个功能实体：接入和移动管理功能(Access and Mobility Management Function，AMF)，会话管理功能(Session Management Function，SMF)，或用户面功能(User Plane Function，UPF)。所述AMF有时也称为AMF设备、AMF实体或其他名称，SMF有时也称为SMF设备、SMF实体或其他名称，UPF有时也称为UPF设备、UPF实体或其他名称。此外，所述核心网设备还可以包括其他的功能实体。这些功能实体可以是分别独立的物理实体，也可以是物理上合设在一起，对此本发明实施例不做限定。
在一种实现方式中，所述目标基站请求第二核心网设备向所述目标基站发送第一数据包的副本，具体可以是：
目标基站向接入和移动管理功能(Access and Mobility Management Function，AMF)设备，发送上述请求消息，该请求消息中可以包括协议数据单元(Protocol Data Unit，PDU)会话标识(如PDU session ID)、被源基站接受/允许的QoS Flow标识(如the list of accepted QoS Flow ID(s))，此外，该请求消息中还可以包括目标基站的地址信息和UE标识信息；AMF设备接收到上述请求消息后，与会话管理功能(Session Management Function，SMF)设备进行会话更新(session update)流程；SMF设备与用户面功能(User Plane Function，UPF)设备进行会话修改(session modification)流程。可选的，目标基站的地址信息可以是以下至少一个：IP地址，或GPRS隧道协议隧道端点标识(GTP Tunnel Endpoint Identifier，GTP TEID)。该目标基站的地址信息可以用于核心网设备确定目标基站的地址，进而核心网设备能与目标基站之间建立起用于传输数据的通道；UE标识信息可以包括以下至少之一：RAN UE NGAP ID、Source NG-RAN node UE XnAP ID reference、Source AMF UE NGAP ID，其中RAN UE NGAP ID(无线接入网络用户设备新一代应用协议标识)，是源基站分配的标识，NG接口(即 NG-RAN节点与核心网设备，如AMF设备，间的接口)上可以根据该标识来识别UE；Source AMF UE NGAP ID(源接入和移动管理功能用户设备新一代应用协议标识)，是源AMF设备分配的标识，该标识对应于源新一代控制面的连接(source NG-C connection)，NG接口(即NG-RAN节点与核心网设备，如AMF设备间的接口)上可以根据该标识来识别UE，且该标识可以用于索引源AMF设备(或服务AMF设备，即源基站连接的AMF设备)处的UE上下文信息；Source NG-RAN node UE XnAP ID reference(源新一代无线接入网络节点用户设备Xn应用协议标识参考)是源基站分配的标识，Xn接口(即两个基站间的接口)上可以根据该标识来识别UE。该UE标识信息可以用于在接入网RAN(例如基站)或核心网CN(例如，核心网设备)唯一识别用户设备，进而核心网设备能与目标基站之间建立起用于传输数据的通道。可选的，AMF设备与SMF设备进行会话更新流程时，在会话更新请求消息(如session update request消息)中可以包括PDU session ID、被源基站接受/允许的QoS Flow标识、目标基站的地址信息以及UE标识信息中的至少一种，对此本发明实施例不做限定；可选的，SMF设备与UPF设备进行会话修改流程时，在会话修改请求消息(如session modification request消息)中可以包括PDU session ID、被源基站接受/允许的QoS Flow标识、目标基站的地址信息以及UE标识信息中的至少一种，对此本发明实施例不做限定。
本实施例中可选的，AMF设备与SMF设备间进行会话更新(session update)流程，SMF设备与UPF设备进行会话修改(session modification)流程。
例如，如图2a所示，AMF设备向SMF设备发送session update request消息，SMF设备收到该请求消息后向UPF设备发送session modification request，UPF设备根据SMF设备的请求进行会话修改，然后UPF设备给SMF设备回复session modification request ACK消息，SMF设备收到该ACK消息后，向AMF设备发送session update request ACK消息，AMF设备收到该ACK消息后，AMF设备给目标基站发送对应于目标基站向AMF设备发送的请求消息(如备份请求消息)的回复消息(如备份请求确认消息duplication request ACK)，目标基站收到备份请求确认消息后，给源基站发送切换请求确认消息。
本实施例中，对于下行数据传输，UPF设备设备进行数据包备份(duplication)，UPF设备向源基站发送第一数据包，且UPF设备向目标基站发送第一数据包的副本的过程，可以称为备份(duplication)过程或duplication操作，第一数据包和第一数据包的副本可以统称为备份(duplication)数据包。对于上行数据传输，用户设备进行数据包备份(duplication)，即用户设备向源基站发送第五数据包，并且用户设备向目标基站发送第五数据包的副本的过程，也可以称为备份(duplication)过程或duplication操作，第五数据包和第五数据包的副本可以统称为备份(duplication)数据包。需要说明的是，数据包和该数据包所对应的副本所携带的数据可以完全相同，也可以不完全相同。例如数据包和该数据包所对应的副本，至少有效负载(如payload)是相同的，但这两份数据包所分别携带的其他信息可以相同，也可以不同，一种示例，这两份数据包所分别携带的地址信息不同，例如，其中一份数据包携带的是源基站的地址信息，该份数据包所对应的副本携带的是目标基站的地址信息，其他的不同之处，在此不做 赘述。
本实施例中，在切换过程中，目标基站接收到切换请求消息后，即启动目标基站和核心网设备(例如AMF设备、SMF设备、UPF设备)之间的通道(tunnel)建立流程，即建立起目标基站、AMF设备、SMF设备、UPF设备之间的传输通道。切换过程中，UPF设备可以分别向源基站和目标基站发送备份数据包，进而，源基站、目标基站可以分别将从UPF设备接收到的备份数据包发送给用户设备，源基站无需向目标基站转发数据，降低了数据转发过程造成的传输时延。
可选的，上述方法还包括：
步骤203、源基站接收来自于所述第二核心网设备的第一数据包。
步骤204、目标基站接收来自于所述第二核心网设备的第二数据包。
可选的，上述方法还包括：
步骤205、响应于所述第一数据包，源基站向用户设备发送第三数据包。
步骤206、响应于所述第二数据包，目标基站向用户设备发送第四数据包。
本发明实施例中，源基站向UE发送第三数据包，以及目标基站向UE发送第四数据包的过程也可以称为duplication过程。第三数据包和第三数据包的副本(即第四数据包)也可以统称为备份(duplication)数据包。
本发明实施例中，可选的，第一数据包和第一数据包的副本(即第二数据包)携带的用于UE的数据相同(例如payload相同)，但报头可以不同(例如地址信息不同)。
本实施例中，源基站接收第一数据包后，可以对第一数据包进行相应处理，例如数据的解析，报头的处理等，再将数据包发送给UE，但UE的数据包的payload没有发生变化。目标基站针对第一数据包的副本的处理过程类似。
本实施例中，可选的，UPF设备启动duplication过程后，(例如，目标基站、AMF设备、SMF设备、UPF设备之间的用于传输备份数据包的通道建立成功后)，UPF设备要发送第一个备份数据包时，可以向源基站发送一个指示信息，例如该指示信息为结束标记(end marker)，该指示信息用于通知源基站UPF设备启动duplication功能，即UPF设备即将开始向源基站发送数据包以及向目标基站发送对应该数据包的副本。该指示信息也可以携带在UPF设备启动duplication过程后，UPF设备向源基站发送的第一个备份数据包的报头里，例如，该指示信息可以包括在GTP-U报头中，本发明对此不做限定。可选的，若源基站接收到该指示信息时，源基站的数据缓存区中还有未发送的用于UE的数据包，即源基站的数据缓存区中缓存有在duplication过程启动前，源基站从UPF设备处接收到的但未发送给用户设备的非备份数据包，则：一种实现方式中，源基站默认优先将上述未发送的用于UE的数据包发送给用户设备，源基站将上述未发送的用于UE的数据包发送给用户设备后再将从UPF设备接收到的备份数据包发送给用户设备；或者，另一种实现方式中，UPF设备向源基站发送的上述指示信息也可以理解为，该指示信息用于指示源基站优先将未发送的用于UE的数据包发送给用户设备，即源基站接收到指示信息后，如该指示信息可以是end marker或者包括在UPF设备向源基站发送的第一个备份数据包的报头里的指示信息，源基站优先将未发送的用于UE的数据包发送给用户设备，源基站将未发送的用于UE的数据包发送给用户设备后再将从UPF设备接收到的备份数据包发送给用户设备。本实施例对此不 做限定。
本实施例中，可选的，针对上行链路，在UPF设备启动duplication过程后(例如，目标基站、AMF设备、SMF设备、UPF设备之间的用于传输备份数据包的通道建立成功后)，UE与目标基站的连接建立后(例如，UE与目标基站的随机接入过程成功，UE成功切换至目标基站后)，UE也可以向源基站发送数据包，且向目标基站发送对应该数据包的副本。源基站和目标基站可以分别将上述数据包和对应上述数据包的副本发送给UPF设备。本发明实施例中可选的，源基站将上述数据包发送给UPF设备，以及目标基站将上述数据包的副本发送给UPF设备的过程，也可以称为duplication过程。上述数据包和上述数据包的副本也可以统称为备份(duplication)数据包。
本实施例中，源基站与目标基站之间进行切换准备过程中，目标基站与核心网设备之间建立传输通道，启用duplication操作，进而，在UE与源基站之间的链路质量恶化前，即将目标基站与核心网设备之间的用于传输备份数据包的通道建立成功，因此，源基站不能成功传输的数据，可以通过目标基站进行传输，减少了切换过程中的数据传输时延且保证了数据传输的可靠性。
实施例二
在切换过程中，对于下行数据传输，核心网设备启动duplication过程后，UPF设备可以向源基站发送数据包，并且向目标基站发送该数据包的副本。源基站将从UPF设备接收到的数据包发送给用户设备，且目标基站将从UPF设备接收到的数据包发送给用户设备，UE分别从源基站、目标基站接收到数据包之后，需要对从源基站以及目标基站处接收到的数据包进行重复包检测、数据包重排序、和/或按序递交等操作，从而使得UE能够正确进行重复包检测或数据包重排序或按序递交。
本领域的技术人员可以理解，本申请中，源基站或目标基站作为接入网设备，在进行上行链路或下行链路传输时，对于接收到的来自核心网设备的数据包发送给UE或者对于接收到的来自UE的数据包发送给核心网设备的过程中，可以对数据包进行必要的处理，例如对包头处理，重排等操作，或者可以是透传。为描述方便，本申请在涉及相关技术时，并不对此进行限定，除非有明确说明。
如图3所示，本实施例提供的方案包括：
步骤301、源基站接收来自于核心网设备的第一数据包。
可选的，核心网设备可以是UPF设备。
步骤302、目标基站接收来自于所述核心网设备的第二数据包，所述第二数据包是所述第一数据包的副本，所述第一数据包与所述第二数据包分别包括第一索引。
其中，所述第一数据包与所述第二数据包分别包括的第一索引的值是相同的。所述第一数据包和所述第二数据包，至少有效负载(payload)是相同的。本申请中，数据包和数据包的副本可以是完全相同的，也可以二者携带的有效payload相同，而其他信息，如包头等信息不同。在一些实现方式中，第一索引是高层序列号，例如该第一索引可以是GPRS隧道协议-用户面(GPRS tunnel protocol–user plane，GTP-U)序列号(sequence number，SN)；或者，该第一索引可以是GTP-U协议层的上层协议栈的序列号，例如，该第一索引可以是传输控制协议(Transmission Control Protocol， TCP)序列号或GTP-U协议层的其他上层的协议层序列号，对此本发明实施例不做限定；或者，可以在现有协议栈中引入一个新的协议层，该第一索引可以是该新引入的协议层所对应的协议层序列号，一种示例，在GTP-U协议层的上层新引入一个协议层，例如，新引入的协议层为高可靠协议层(High Reliability Protocol，HRP)，该第一索引可以是HRP序列号，对此本发明实施例不做限定。需要说明的是，新引入的协议层可以有其他命名或表示形式，本发明实施例不做限定。
可选的，所述第一索引的取值是服务质量(Quality of Service，QoS)流(flow)粒度的。即，分别对应于不同的QoS flow的数据包中包括的第一索引是分别独立编号的。可选的，分别对应于不同的QoS flow的数据包中包括的第一索引的取值可以相同或者不同，对此本发明实施例不做限定。由于QoS flow可以是数据无线承载(Data Radio Bearer，DRB)粒度的，即只有一个QoS flow可以映射到同一个DRB，不同的QoS flow映射到不同的DRB，因此，所述第一索引的取值也可以是DRB粒度的。
步骤303、所述源基站，响应于所述第一数据包，向用户设备发送第三数据包，所述第三数据包包括第二索引。
可选的，第二索引可以是包数据汇聚协议(Packet Data Convergence Protocol，PDCP)序列号。本实施例中，第一数据包和第三数据包分别携带的数据中，至少内容相同，但报头信息可以相同或不同。例如，第一数据包和第三数据包，至少有效负载(如payload)相同，但第一数据包包括的报头信息与第三数据包包括的报头信息相同或者不同，一种示例，第三数据包中包括PDCP SN，但第一数据包中不包括PDCP SN，另外，报头信息还可以有其他的不同之处，在此不做赘述。
步骤304、所述源基站向所述目标基站发送第一指示信息，所述第一指示信息指示所述第一索引和与所述第一索引对应的所述第二索引之间的映射关系。
本实施例中，步骤303和步骤304没有严格的先后关系，例如，可以先执行步骤303，再执行步骤304，也可以先执行步骤304，再执行步骤303，或者同时执行步骤303,304。
在一种可能的实现方式中，对于下行数据，UPF设备未启动duplication操作时，UPF设备发送给源基站的数据包的报头中携带了第一索引，如GTP-U报头中携带GTP-U SN。在切换过程发生前，源基站与UE进行下行链路(downlink,DL)数据传输(有时也称为DL数传)时，第一索引和与该第一索引对应的第二索引之间的映射关系已被确定，例如PDCP SN与GTP-U SN的映射关系是确定的。为了保证源基站与目标基站分别使用的映射关系保持一致，则源基站可以将确定出的DL的第一索引和与该第一索引对应的第二索引之间的映射关系，即第一指示信息，包括在切换请求消息中发送给目标基站。可选的，该第一指示信息也可以包括在其他消息中发送给目标基站，不做限定。
在另一种可能的实现方式中，对于下行数据，UPF设备未启动duplication操作时，UPF设备发送给源基站的数据包的报头中没有携带第一索引，如GTP-U报头中没有携带GTP-U SN。当UPF设备启动duplication操作时，UPF设备发送给源基站的数据包的报头中携带第一索引，如UPF设备从第一个备份包开始，在备份包的GTP-U报头中携带GTP-U SN。即在切换过程发生前，源基站与UE进行DL数据传输时，数据包 中不包括GTP-U SN，即源基站无法确定第一索引和与该第一索引对应的第二索引的映射关系。对于下行，UPF设备发送第一duplication数据包时，GTP-U报头才携带GTP-U SN，当UPF设备要给源基站发第一duplication包时，UPF设备可以先给源基站发送一个指示信息，例如，end marker，或者，UPF设备给源基站发送的第一duplication数据包的包头中携带一个指示信息，上述指示信息用于通知源基站UPF设备开始进行duplication数据包的发送，源基站收到UPF设备发来的第一duplication数据包后，源基站才能确定出DL的GTP-U SN与PDCP SN的映射关系，并将该映射关系发送给目标基站，具体的，可以通过新定义的Xn消息(两个基站间传输的消息)，或重用现有的Xn消息发送该映射关系，如现有的SN status transfer消息，本发明实施例不做限定。目标基站收到该映射关系后，开始将从UPF设备收到的DL duplication数据包发送给UE。目标基站若在得知该映射关系前，收到UPF设备发送的数据包，则目标基站缓存该数据包。
步骤305、所述目标基站，响应于所述第二数据包，向所述用户设备发送第四数据包，所述第三数据包和所述第四数据包均分别包括第二索引。
本实施例中，第二数据包和第四数据包分别携带的数据中至少内容相同，但报头信息可以相同或不同。例如，第二数据包和第四数据包，至少有效负载(如payload)相同，但第二数据包包括的报头信息与第四数据包包括的报头信息可以相同，也可以不同。一种示例，第四数据包中包括PDCP SN，但第二数据包中不包括PDCP SN，其他的不同之处，在此不做赘述。
上述第一索引和与上述第一索引对应的第二索引之间的映射关系可以通过多种方式来指示，下面给出几种可能的实施方式：
方式一：
所述第一指示信息包括所述第一索引的值以及与所述第一索引对应的所述第二索引的值。
例如，源基站从UPF设备接收到的数据包中携带的GTP-U SN为1，源基站根据当前的数据传输情况，确定出该数据包所对应的PDCP SN为2，则第一指示信息指示的映射关系可以如下表1所示。
表1
DL GTP-U SN DL PDCP SN
1 2
第一指示信息包括DL的{GTP-U SN，PDCP SN}。GTP-U SN与PDCP SN的先后顺序可以互换，例如如表2所示，本发明实施例不做限定。
表2
DL PDCP SN DL GTP-U SN
2 1
GTP-U SN和PDCP SN的具体数值可以由源基站根据接收到的数据包具体确定。另一种可能，源基站从UPF设备除了接收到携带GTP-U SN为1的数据包，源基站还从UPF设备接收到携带GTP-U SN为2、3等的数据包，源基站根据当前的数据传输情况，确定出携带GTP-U SN为2的数据包所对应的PDCP SN为3，携带GTP-U SN为3的数据包所对应的PDCP SN为4，以此类推，不做赘述。则第一指示信息指示的映射关系也可以如下表3所示。
表3
DL GTP-U SN DL PDCP SN
2 3
本实施例中可选的，第一指示信息携带的具体序列号的取值不做具体限定，只要能指示出第一索引和与该第一索引对应的第二索引之间的映射关系即可。
方式二：
所述第一指示信息包括所述第一索引和与所述第一索引对应的所述第二索引之间的映射公式。
例如，第一指示信息携带公式PDCPSN＝GTP-USN+delta。delta的具体取值可以由源基站根据具体的数据传输情况灵活确定，可选的，delta可以为任意自然数。或者PDCP SN＝GTP-U SN-delta。具体使用哪种表达方式，可以由源基站灵活决定。
方式三：
所述第一指示信息包括所述第一索引和与所述第一索引对应的所述第二索引所分别对应的数值之间的差值。
例如，第一指示信息携带两个索引的差值，如delta1。delta1的具体取值可以由源基站根据具体的数据传输情况灵活确定，可选的，delta1可以为任意自然数。
该方式中，目标基站接收到该第一指示信息后，基于delta1，可以得到PDCP SN＝GTP-U SN+delta1或者PDCP SN＝GTP-U SN-delta1。具体使用哪种表达方式，可以由源基站灵活决定。
本实施例中，用户设备接收到来自源基站的第三数据包以及接收到来自目标基站的第四数据包之后，对第三数据包以及第四数据包进行重复包检测、数据包重排序、和/或按序递交等操作，由于源基站与目标基站使用的映射关系是相同的，保证了用户设备能够对分别从源基站以及目标基站接收到的备份数据包正确地进行重复包检测或数据包重排序或按序递交。
上述实施例是针对下行数据传输，下文针对上行数据传输给出另一种方案，上行传输方案和下行传输方案可以单独实施，也可以组合应用到同一套系统中。
针对上行链路，本实施例提供的方法包括：
步骤306、所述源基站接收来自于所述UE的第五数据包。
步骤307、所述目标基站接收来自于所述UE的第六数据包，所述第六数据包是所述第五数据包的副本，所述第五数据包与所述第六数据包均分别包括第三索引。其中，所述第五数据包与所述第六数据包分别包括的第三索引的取值是相同的。所述第五数据包和所述第六数据包，至少有效负载(如payload)是相同的。该第三索引可以是PDCP SN。
需要说明的是，该第五数据包和该第六数据包，至少有效负载(如payload)是相同的，但这两份数据包所分别携带的其他信息可以相同或不同。一种示例，这两份数据包所分别携带的地址信息不同，例如，第五数据包携带的是源基站的地址信息，第六数据包携带的是目标基站的地址信息，其他的不同之处，在此不做赘述。
步骤308、所述源基站，响应于所述第五数据包，向所述核心网设备发送第七数据包。其中，所述核心网设备可以是UPF设备，所述第七数据包包括第四索引。
本实施例中，第五数据包和第七数据包分别携带的数据中内容相同，但报头信息可以相同或不同。
例如，第五数据包和第七数据包，至少有效负载(如payload)相同，但第五数据包包括的报头信息与第七数据包包括的报头信息可以相同也可以不同。
一种示例，第七数据包中包括高层序列号(即第四索引)，例如该高层序列号可以是GTP-USN；或者，该高层序列号可以是GTP-U协议层的上层协议栈的序列号，例如，该高层序列号可以是TCP SN或GTP-U协议层的其他上层的协议层序列号，对此本发明实施例不做限定；或者，可以在现有协议栈中引入一个新的协议层，该高层序列号可以是该新引入的协议层的协议层序列号。一种可能的实现方式中，在GTP-U协议层的上层新引入一个新的协议层，例如，新引入的协议层为高可靠协议层(High Reliability Protocol，HRP)，该高层序列号可以是HRP SN，对此本发明实施例不做限定。需要说明的是，新引入的协议层可以有其他命名或表示形式，本发明实施例不做限定。
可选的，第五数据包和第七数据包至少payload相同，但第五数据包中不包括上述高层序列号，其他的不同之处，在此不做赘述。
步骤309、所述源基站向所述目标基站发送第三指示信息，所述第三指示信息指示所述第三索引和与所述第三索引对应的所述第四索引之间的映射关系。
可选的，步骤309可以在步骤308之前、或在步骤308之后、或者与步骤308同时执行，对此本发明实施例不做限定。
具体的，对于第三指示信息，一种可能的实现方式中，对于上行数据，UE未启动duplication操作时，源基站接收到UE发送的数据包之后，对该数据包的报头进行必要处理。例如，在该数据包的报头中携带第四索引，如源基站在数据包的GTP-U报头中携带GTP-U SN。则，在切换过程发生前，例如，源基站与UPF设备进行UL备份数据包传输之前，或者UL备份数据包传输过程中，或者UL备份数据包传输之后，可以确定第三索引和与该第三索引对应的第四索引之间的映射关系，如确定PDCP SN与GTP-U SN的映射关系。为了保证源基站与目标基站分别使用的映射关系保持一致，源基站可以将确定出的UL的第三索引和与该第三索引对应的第四索引之间的映射关系，即第三指示信息，包括在切换请求消息中发送给目标基站。可选的，该第三指示信息也可以包括在其他消息中发送给目标基站，本发明实施例不做限定。
对于第三指示信息，另一种可能的实现方式中，对于上行数据，UE未启动duplication操作时，源基站接收到UE发送的数据包之后，源基站在该数据包的报头中不携带第四索引，如GTP-U报头中没有携带GTP-U SN。当UE启动duplication操作后，源基站接收到UE开始发送的第一备份数据包之后，源基站在数据包的报头中携 带第四索引，如GTP-U报头中携带GTP-U SN。即在切换过程发生前，源基站与UE进行UL数据传输时，源基站发送给UPF设备的数据包中不包括GTP-U SN，即源基站无法确定第三索引和与该第三索引对应的第四索引之间的映射关系。对于上行，源基站接收到UE发送的第一duplication数据包后，源基站在接收到的备份数据包的GTP-U报头中携带GTP-U SN。当UE要给源基站发第一duplication包时，UE先给源基站发送一个指示信息，例如，结束标识(end marker)，或者，UE给源基站发送的第一duplication数据包的包头中携带一个指示信息，上述指示信息用于通知源基站UE开始进行duplication数据包的发送，源基站收到UE发来的第一duplication数据包后，源基站可以确定出UL GTP-U SN与PDCP SN的映射关系，并将该映射关系发送给目标基站，具体的，可以通过新定义的Xn消息，或重用现有的Xn消息发送该映射关系，如SN status transfer消息，本发明实施例不做限定。目标基站收到该映射关系后，将从UE收到的UL duplication数据包发送给UPF设备。
上述第三索引和与该第三索引对应的第四索引之间的映射关系可以有多种指示方式，下面给出几种可选的方式：
方式一：
所述第三指示信息包括所述第三索引的值以及与所述第三索引对应的所述第四索引的值。
例如，源基站从UE接收到的数据包中携带的PDCP SN为5，源基站根据当前的数据传输情况，确定出该数据包所对应的GTP-U SN为3，则第三指示信息指示的映射关系可以如下表4所示。
表4
UL GTP-U SN UL PDCP SN
3 5
第三指示信息包括UL的{GTP-U SN，PDCP SN}。GTP-U SN与PDCP SN的先后顺序可以互换，例如如表5所示，本发明实施例不做限定。
表5
UL PDCP SN UL GTP-U SN
5 3
GTP-U SN和PDCP SN的具体数值可以由源基站根据接收到的数据包具体确定，例如，另一种可能，源基站从UE除了接收到携带PDCP SN为5的数据包，源基站还从UE接收到携带PDCP SN为2、3、6等的数据包，源基站根据当前的数据传输情况，确定出携带PDCP SN为2的数据包所对应的GTP-U SN为0，携带PDCP SN为3的数据包所对应的GTP-U SN为1，携带PDCP SN为6的数据包所对应的GTP-U SN为4，以此类推，不做赘述。则第三指示信息指示的映射关系也可以如下表6所示。
表6
UL GTP-U SN UL PDCP SN
1 3
本实施例中可选的，第三指示信息携带的具体序列号的取值不做具体限定，只要能指示出第三索引和与该第三索引对应的第四索引之间的映射关系即可。
方式二：
所述第三指示信息包括所述第三索引和与所述第三索引对应的所述第四索引之间的映射公式。
例如，第三指示信息携带公式PDCPSN＝GTP-USN+delta’。delta’的具体取值可以由源基站根据具体的数据传输情况灵活确定，可选的，delta’可以为任意自然数。或者PDCP SN＝GTP-U SN-delta’。具体使用哪种表达方式，可以由源基站灵活决定。可选的，上述第一指示信息中包括的delta与上述第三指示信息中包括的delta’可以相同或不同，本发明实施例不做限定。
方式三：
所述第三指示信息包括所述第三索引和与所述第三索引对应的所述第四索引所分别对应的数值之间的差值。
例如，第三指示信息携带两个索引的差值，如delta2。delta2的具体取值可以由源基站根据具体的数据传输情况灵活确定，可选的，delta2可以为任意自然数。
该方式中，目标基站接收到该第三指示信息后，基于delta2，可以得到PDCP SN＝GTP-U SN+delta2。或者PDCP SN＝GTP-U SN-delta2。具体使用哪种表达方式，可以由源基站灵活决定。
可选的，上述第一指示信息中包括的delta1与上述第三指示信息中包括的delta2可以相同或不同，本发明实施例不做限定。
上述实施例中，UL的GTP-U SN与该GTP-U SN所对应的PDCP SN之间的映射关系，和，DL的GTP-U SN与该GTP-U SN所对应的PDCP SN之间的映射关系，可以包括在同一个指示信息或不同的指示信息中，本发明实施例不做限定。可选的，上述第一索引和第二索引的映射关系以及第三索引和第四索引的映射关系，即UL的映射关系和DL的映射关系可以通过同一条Xn消息或不同的Xn消息携带，如该Xn消息可以为切换请求消息或SN status transfer消息，本发明实施例不做限定。可选的，UL的具体映射关系跟DL的具体映射关系可以一样或不一样，本发明实施例不做限定。
步骤310、所述目标基站，响应于所述第六数据包，向所述核心网设备发送第八数据包，所述第七数据包与所述第八数据包均分别包括第四索引。
其中，所述核心网设备可以是UPF设备。
其中，第四索引是高层序列号，例如该第四索引可以是GTP-USN；或者，该第四索引可以是GTP-U协议层的上层协议栈的序列号，例如，该第四索引可以是TCP SN或GTP-U协议层的其他上层的协议层序列号，对此本发明实施例不做限定；或者，可以在现有协议栈中引入一个新的协议层，该第四索引可以是该新引入的协议层对应的协议层序列号，一种示例，在GTP-U协议层的上层新引入一个协议层，例如，新引入的协议层为高可靠协议层(High Reliability Protocol，HRP)，该第四索引可以是HRP SN，对此本发明实施例不做限定。需要说明的是，新引入的协议层可以有其他命名或表示形式，本发明实施例不做限定。可选的，所述第四索引的取值是服务质量(Quality of Service，QoS)流(flow)粒度的。即，分别对应于不同的QoS flow的数据包中包 括的第四索引是分别独立编号的。可选的，分别对应于不同的QoS flow的数据包中包括的第四索引的取值可以相同或者不同，对此本发明实施例不做限定。由于QoS flow可以是数据无线承载(Data Radio Bearer，DRB)粒度的，即只有一个QoS flow可以映射到同一个DRB，不同的QoS flow映射到不同的DRB，因此，所述第四索引的取值也可以是DRB粒度的。
本实施例中，第六数据包和第八数据包分别携带的数据中至少内容相同，但报头信息可以相同或不同。例如，第六数据包和第八数据包，至少有效负载(如payload)相同，但第六数据包包括的报头信息与第八数据包包括的报头信息相同或不同。一种示例，第八数据包中包括第四索引，但第六数据包中不包括第四索引，其他的不同之处，在此不做赘述。
本实施例中，UPF设备接收到来自源基站的第七数据包以及接收到来自目标基站的第八数据包之后，对第七数据包以及第八数据包进行重复包检测、数据包重排序、和/或按序递交等操作，由于源基站与目标基站使用的映射关系是相同的，保证了UPF设备能够对分别从源基站以及目标基站接收到的备份数据包正确地进行重复包检测或数据包重排序或按序递交。
现有切换流程中，源基站可以向目标基站发送SN Status Transfer消息，具体的，对于上行数据传输，SN status transfer消息中指示第一个丢失的上行数据包的SN以及UE需要在目标基站进行重传的上行数据包的接收状态；对于下行，SN status transfer消息中指示，当目标基站需要给从UPF设备新接收到的未分配PDCP序号的下行数据包进行PDCP SN分配时，目标基站分配的起始PDCP SN的值(即目标基站从哪个PDCP SN的值开始分配序号)。
针对上文中的任一实施例，可选的，源基站默认不需要给目标基站发送SN status transfer消息，对于UL数据传输，由于目标基站根据PDCP SN以及源基站通知的UL的GTP-U SN与该GTP-U SN所对应的PDCP SN之间的映射关系，确定GTP-U SN的取值，源基站可以不执行SN status transfer流程；对于DL数据传输，目标基站根据数据包的GTP-U报头中的GTP-U SN以及源基站通知的DL的GTP-U SN与该GTP-U SN所对应的PDCP SN之间的映射关系，确定PDCP SN的取值，所以，源基站可以不向目标基站发送SN status transfer消息。或者，可选的，核心网设备启动duplication过程后，核心网设备，例如UPF设备，可以通知源基站在切换过程中是否需要执行SN status transfer消息的发送，例如，UPF设备启动备份包发送时(例如，目标基站、AMF设备、SMF设备、UPF设备之间的用于传输备份数据包的通道建立成功后)，UPF设备可以给源基站发送一个指示消息，如，该指示信息可以是end marker或该指示信息是UPF设备在给源基站发送的第一duplication数据包的包头里所包括的指示信息。例如，源基站发送的第一duplication数据包的包头里包括的指示信息为二进制数值“0”或“1”，“1”指示源基站需要向目标基站发送SN status transfer消息，“0”指示源基站不需要向目标基站发送SN status transfer消息，对指示信息的具体形式本发明实施例不做限定。
本实施例中，第一duplication数据包，可以是一个或多个数据包。例如：第一 duplication数据包是UE启动duplication过程后，UE向源基站或目标基站发送的第一个数据包，或者第一组数据包，或者第一组数据包中的第一个数据包；或者，第一duplication数据包是核心网设备启动duplication过程后，核心网设备向源基站或目标基站发送的第一个数据包，或者第一组数据包，或者第一组数据包中的第一个数据包。本发明实施例对此并不限定。
实施例三
为了减少切换过程中的数据转发时延，实施例一、二给出了用户设备和/或核心网设备启动duplication的方案，从而，源基站可以不与目标基站之间进行数据的转发，例如，对于上行传输，源基站不会将从用户设备接收到的乱序的上行数据包转发给目标基站，乱序的上行数据包可以包括，从第一个乱序的UL数据包开始，以及第一个乱序包之后的其他所有数据包(若存在的话)；对于下行，源基站不会将已经发送给用户设备但是没有被用户设备确认成功接收的下行数据包以及核心网设备新发送给源基站的数据包转发给目标基站，从而减少切换过程中的数据传输时延。对于下行数据传输，由于在源链路恶化前，核心网与目标基站的通道已经建立，即使源基站与目标基站之间不进行数据转发，对于源基站无法转发给目标基站的下行数据包，UPF设备可以将这些无法转发的数据包进行备份/复制，并发送给目标基站，降低了下行数据传输过程中的丢包率。但对于上行数据传输，本实施例针对源基站与目标基站之间不进行数据转发(data forwarding)流程所导致的上行数据传输问题，给出一种解决方案。
如图4所示，包括：
步骤401、用户设备向源基站发送数据包P 1，P 2……P N。
可选的，结合前文中的实施例二，数据包P 1，P 2……P N中包括第三索引，例如PDCP SN。
步骤402、用户设备向目标基站发送数据包P i至P N，其中数据包P i为数据包P1至PN中未被所述源基站正确接收到的第一个数据包，N为大于等于1的整数，i为大于等于1且小于等于N的整数。
可选的，结合前文中的实施例二，数据包P i至P N中包括第三索引，例如PDCP SN。
如果所述UE未收到来自于所述源基站的针对所述数据包P i的确认ACK(例如，超过预设时间未收到针对所述数据包P i的ACK)或者接收到来自于所述源基站的针对所述数据包P i的否定确认NACK，且UE接收到所述数据包P 1至P N中P i之前的所有数据包的确认ACK，则所述UE确定所述数据包P i为所述数据包P 1至P N中未被所述源基站正确接收的第一个数据包。
步骤403、目标基站接收数据包P i至P N。
本实施例中可选的，所述数据包P1至PN分别包括的第三索引是连续且递增的。
步骤404、所述目标基站向核心网设备发送数据包P i至P N。
可选的，结合前文中的实施例二，目标基站根据第三索引和与第三索引对应的第四索引之间的映射关系，例如PDCP SN与GTP-U SN的映射关系，确定数据包P i至P N报头中分别包括的第四索引。
其中，第四索引是高层序列号，例如该第四索引可以是GTP-USN；或者，该第四 索引可以是GTP-U协议层的上层协议栈的序列号，例如，该第四索引可以是TCP SN或GTP-U协议层的其他上层的协议层序列号，对此本发明实施例不做限定；或者，可以在现有协议栈中引入一个新的协议层，该第四索引可以是该新引入的协议层对应的协议层序列号，一种示例，在GTP-U协议层的上层新引入一个协议层，例如，新引入的协议层为高可靠协议层(High Reliability Protocol，HRP)，该第四索引可以是HRP SN，对此本发明实施例不做限定。需要说明的是，新引入的协议层可以有其他命名或表示形式，本发明实施例不做限定。可选的，所述第四索引的取值是服务质量(Quality of Service，QoS)流(flow)粒度的。即，分别对应于不同的QoS flow的数据包中包括的第四索引是分别独立编号的。可选的，分别对应于不同的QoS flow的数据包中包括的第四索引的取值可以相同或者不同，对此本发明实施例不做限定。由于QoS flow可以是数据无线承载(Data Radio Bearer，DRB)粒度的，即只有一个QoS flow可以映射到同一个DRB，不同的QoS flow映射到不同的DRB，因此，所述第四索引的取值也可以是DRB粒度的。
可选的，步骤404中的目标基站可以从源基站获得第三索引和与第三索引对应的第四索引之间的映射关系。
步骤405、所述源基站向所述核心网设备发送所述数据包P 1至P N中P i之前的数据包。
可选的，结合前文中的实施例二，源基站根据第三索引和与第三索引对应的第四索引之间的映射关系，例如PDCP SN与GTP-U SN的映射关系，确定数据包P 1至PN中P i之前的所有数据包的报头中分别包括的第四索引。
步骤404和405先后顺序并不限定。例如可以先执行步骤404再执行405，也可以先执行405再执行404，或者404与405同时执行。
可选的，上述方法还包括：
步骤406，核心网设备从源基站接收数据包P 1至P N中P i之前的所有数据包。
步骤407，核心网设备从目标基站接收数据包P i至P N。
步骤408、核心网设备根据数据包P 1至P N中包括的第四索引，进行重复包检测，重排序，和/或按序递交等操作。
下面通过几个例子，对上述方案进一步说明：
例1：
在UE成功切换至目标基站前(UE与目标基站之间的连接还未建立成功)，UE向源基站发送数据包P1，P2，P3，P4，P5，P6，P7，数据包P1至P7的PDCP SN是连续且递增的。
其中，数据包P1，P2，P3，P6，P7被源基站正确接收(UE接收到源基站分别针对数据包P1，P2，P3，P6，P7的反馈是确认(acknowledgement,ACK)，数据包P4，P5未被源基站正确接收(UE未接收到源基站针对数据包P4，P5的反馈，或者UE接收到源基站针对数据包P4，P5的反馈是否定确认(Negative Acknowledgment，NACK)。
由于源基站没有正确接收数据包P4，P5，尽管正确接收到数据包P6，P7，但源基站可以判定数据包P6，P7为乱序的数据包。
则UE跟目标基站建立无线资源控制(radio resource control，RRC)连接后，可 以向目标基站发送数据包P4，P5，P6，P7。
目标基站向核心网设备发送数据包P4，P5，P6，P7。
可选的，目标基站向核心网设备发送的数据包P4，P5，P6，P7中分别包括各自对应的第四索引，如GTP-U SN。
源基站向核心网设备发送数据包P1，P2，P3。
可选的，源基站向核心网设备发送的数据包P1，P2，P3中分别包括各自对应的第四索引，如GTP-U SN。
UPF设备对从源基站和目标基站接收到的所有数据包P1至P7，根据数据包P1至P7分别携带的第四索引，进行重复包检测，重排序，和/或按序递交等操作。
例2：
在UE成功切换至目标基站前(UE与目标基站之间的连接还未建立成功)，UE向源基站发送数据包P1，P2，P3，P4，P5，P6，P7，数据包P1至P7的PDCP SN是连续且递增的。
其中，数据包P1，P2，P3被源基站正确接收(UE接收到分别针对数据包P1，P2，P3的ACK)，数据包P4，P5，P6，P7未被源基站正确接收(UE未接收到源基站针对数据包P4，P5，P6，P7的反馈，或者UE接收到针对数据包P4，P5，P6，P7的反馈为NACK)。
则UE跟目标基站建立RRC连接后，向目标基站发送数据包P4，P5，P6，P7。
目标基站向核心网设备发送数据包P4，P5，P6，P7。
可选的，目标基站向核心网设备发送的数据包P4，P5，P6，P7中分别包括各自对应的第四索引，如GTP-U SN。
源基站向核心网设备发送数据包P1，P2，P3。
可选的，源基站向核心网设备发送的数据包P1，P2，P3中分别包括各自对应的第四索引，如GTP-U SN。
UPF设备对从源基站和目标基站接收到的所有数据包P1至P7，根据数据包P1至P7分别携带的第四索引，进行重复包检测，重排序，和/或按序递交等操作。
本实施例可选的，步骤402之前，上述方法还包括：
步骤409、用户设备接收来自于所述源基站的指示信息，所述指示信息指示所述用户设备向所述目标基站发送数据包P i至P N。
可选的，所述指示信息包括在RRC重配置消息中。
可选的，该RRC消息可以是携带同步重配置信元(reconfiguration with sync)的RRC重配置消息或者可以是携带移动性控制信息信元(mobility control info)的RRC连接重配置消息。
可选的，上述指示信息可以是源基站生成后发送给UE；上述指示信息也可以是目标基站生成后发送给源基站，由源基站透传给UE，例如，目标基站生成上述指示信息，目标基站向源基站发送切换请求确认消息时，在该消息中包含该指示信息，源基站接收到切换请求确认消息后，将该指示信息通过上述RRC重配置消息透传给UE。
本实施例中可选的，当UE确定所述数据包Pi为所述数据包P1至PN中未被所述源基站正确接收的第一个数据包时，默认向目标基站发送数据包Pi至PN。
本实施例中的上行传输方案，降低了丢包可能性，提高了数据传输可靠性。
本实施例还给出了另一种上行数据传输方案，如图5所示，包括：
步骤501、用户设备向源基站发送数据包P 1，P 2……P N，N为大于等于1的整数。
可选的，结合前文中的实施例二，数据包P 1，P 2……P N中包括第三索引，例如PDCP SN。
步骤502、源基站接收来自于用户设备的第一组数据包。
可选的，第一组数据包可以包括数据包P 1，P 2……P N中的至少一个数据包。
可选的，源基站也可能未从UE正确接收到数据包。步骤502是可选步骤。
可选的，结合前文中的实施例二，第一组数据包中的数据包分别包括第三索引，例如PDCP SN。
步骤503、用户设备向目标基站发送第二组数据包。
第二组数据包是所述用户设备向所述源基站发送的所述数据包P 1，P 2……P N中未被所述源基站正确接收的数据包的重传数据包。第二组数据包包括至少一个数据包。
可选的，结合前文中的实施例二，第二组数据包中的数据包分别包括第三索引。
本实施例中，重传数据包，可以指UE向源基站发送后未被源基站正确接收，然后UE向目标基站再次发送的上述数据包。
可选的，用户设备向目标基站发送第二组数据包之前，接收来自于所述源基站的指示信息，所述指示信息指示所述用户设备向所述目标基站发送第二组数据包。
可选的，所述指示信息可以包括在RRC重配置消息中。
可选的，该RRC消息可以是携带同步重配置信元(reconfiguration with sync)的RRC重配置消息或者可以是携带移动性控制信息信元(mobility control info)的RRC连接重配置消息。
可选的，上述指示信息可以是源基站生成后发送给UE；上述指示信息也可以是目标基站生成后发送给源基站，由源基站透传给UE，例如，目标基站生成上述指示信息，目标基站向源基站发送切换请求确认消息时，在该消息中包含该指示信息，源基站接收到切换请求确认消息后，将该指示信息通过上述RRC重配置消息透传给UE。
步骤504、目标基站接收来自于所述用户设备的第二组数据包。
步骤505、所述源基站向核心网设备发送所述第一组数据包。
可选的，源基站接收到的第一组数据包中的数据包分别包括的第三索引可以是连续或者不连续的。在第三索引不连续的情况下，源基站可以将所有正确接收的数据包发送给核心网设备。
可选的，结合前文中的实施例二，源基站根据第三索引和与第三索引对应的第四索引之间的映射关系，例如PDCP SN与GTP-U SN的映射关系，确定第一组数据包中的数据包的报头中分别包括的第四索引。
可选的，在步骤505之前，所述源基站接收来自于所述UE的指示信息，所述指示信息指示所述源基站向UPF发送所述第一组数据包。
可选的，所述指示信息可以包括在RRC消息中，或层1消息中，或层2消息中，本实施例不做限定。
可选的，该RRC消息可以是RRC重配置完成消息，或者可以是其他消息，本实施例不做限定。可选的，所述指示信息可以包括在下行控制信息(downlink control information,DCI)中。可选的，所述指示信息可以包括在媒体接入控制(media access control,MAC)控制元素(control element,CE)消息中，本实施例不做限定。
可选的，所述指示信息可以包括在UE发送给源基站的第一备份数据包的报头中，例如PDCP报头中包含该指示信息。
步骤506、所述目标基站向所述核心网设备发送所述第二组数据包。
可选的，结合前文中的实施例二，目标基站根据第三索引和与第三索引对应的第四索引之间的映射关系，例如PDCP SN与GTP-U SN的映射关系，确定第二组数据包中的数据包的报头中分别包括的第四索引。
可选的，步骤506中的第三索引和与第三索引对应的第四索引之间的映射关系是从源基站接收到的。
本发明实施例中可选的，步骤505和步骤506没有严格的时间关系。
可选的，上述方法还包括：
步骤507，核心网设备从源基站接收第一组数据包。
步骤508，核心网设备从目标基站接收第二组数据包。
步骤509、核心网设备根据第一组数据包和第二组数据包中的所有数据包分别包括的第四索引，进行重复包检测，重排序，和/或按序递交等操作。
下面通过几个例子，对上述方案进一步说明：
例1：
在UE成功切换至目标基站前(UE与目标基站之间的RRC连接还未建立成功)，UE向源基站发送数据包P1，P2，P3，P4，P5，P6，P7，数据包P1至P7的PDCP SN是连续且递增的。
其中，数据包P1，P2，P3，P6，P7被源基站正确接收(UE接收到分别针对数据包P1，P2，P3，P6，P7的ACK)，数据包P4，P5未被源基站正确接收(例如，UE未接收到源基站针对数据包P4，P5的反馈，或者UE接收到针对数据包P4，P5的反馈是NACK)。
则UE跟目标基站建立RRC连接后，向目标基站发送数据包P4，P5。
可选的，UE向目标基站发送的数据包P4，P5中分别包括各自对应的第三索引，如PDCP SN。
目标基站向核心网设备发送数据包P4，P5。
可选的，目标基站向UPF发送的数据包P4，P5中分别包括各自对应的第四索引，如GTP-U SN。
源基站向核心网设备发送数据包P1，P2，P3，P6，P7。
可选的，源基站向核心网设备发送的数据包P1，P2，P3，P6，P7中分别包括各自对应的第四索引，如GTP-U SN。
UPF设备对从源基站和目标基站接收到的所有数据包P1至P7，根据数据包P1至P7分别携带的第四索引，进行重复包检测，重排序，和/或按序递交等操作。
例2：
在UE成功切换至目标基站前(UE与目标基站之间的RRC连接还未建立成功)，UE向源基站发送数据包P1，P2，P3，P4，P5，P6，P7，数据包P1至P7的PDCP SN是连续且递增的。
其中，数据包P1，P2，P3被源基站正确接收(例如，UE接收到分别针对数据包P1，P2，P3的ACK)，数据包P4，P5，P6，P7未被源基站正确接收(例如，UE未接收到针对数据包P4，P5，P6，P7的反馈，或者UE接收到分别针对数据包P4，P5，P6，P7的反馈是NACK)。
则UE在跟目标基站建立RRC连接后，向目标基站发送数据包P4，P5，P6，P7。
可选的，UE向目标基站发送的数据包P4，P5，P6，P7中分别包括各自对应的第三索引，如PDCP SN。
目标基站向核心网设备发送数据包P4，P5，P6，P7。
可选的，目标基站向核心网设备发送的数据包P4，P5，P6，P7中分别包括各自对应的第四索引，如GTP-U SN。
源基站向核心网设备发送数据包P1，P2，P3。
可选的，源基站向核心网设备发送的数据包P1，P2，P3中分别包括各自对应的第四索引，如GTP-U SN。
UPF设备对从源基站和目标基站接收到的所有数据包P1至P7，根据数据包P1至P7分别携带的第四索引，进行重复包检测，重排序，和/或按序递交等操作。
例3：
在UE成功切换至目标基站前(UE与目标基站之间的RRC连接还未建立成功)，UE向源基站发送数据包P1，P2，P3，P4，P5，P6，P7，数据包P1至P7的PDCP SN是连续且递增的。
其中，数据包P1至P7均未被源基站正确接收(UE未接收到分别针对数据包P1至P7的ACK，或者UE接收到分别针对数据包P1至P7的NACK)。
则UE在跟目标基站建立RRC连接后，向目标基站发送数据包P1至P7。
可选的，UE向目标基站发送的数据包P1至P7中分别包括各自对应的第三索引，如PDCP SN。
目标基站向核心网设备发送数据包P1至P7。
可选的，目标基站向核心网设备发送的数据包P1至P7中分别包括各自对应的第四索引，如GTP-U SN。
UPF设备对从目标基站接收到的所有数据包P1至P7，根据数据包P1至P7分别携带的第四索引，进行重复包检测，重排序，和/或按序递交等操作。
本实施例中的上行传输方案，源基站无需向目标基站转发UE的数据包时，降低了丢包可能性，提高了数据传输可靠性。
对于上文中的任一实施例，可选的，对应的用户面协议栈架构可以如图6所示，具体的，核心网设备，例如UPF设备，所对应的协议栈包括物理(physical,PHY)层(也可以称为层1，L1)，层2(如，层2包括媒体接入控制(media access control，MAC)层、无线链路控制(radio link control，RLC)层、分组数据汇聚层协议(packet data  convergence protocol，PDCP)层、业务数据适应协议(Service Data Adaptation Protocol,SDAP)层)，用户数据报协议/互联网(User Datagram Protocol/Internet Protocol，UDP/IP)层，GTP-U层，协议数据单元(Protocol Data Unit,PDU)层；接入网设备，例如源基站或者目标基站，所对应的协议栈包括物理层(physical,PHY)，层2(如，层2包括媒体接入控制(media access control，MAC)层、无线链路控制(radio link control，RLC)层、分组数据汇聚层协议(packet data convergence protocol，PDCP)层、业务数据适应协议(Service Data Adaptation Protocol,SDAP)层)，用户数据报协议/互联网(User Datagram Protocol/Internet Protocol，UDP/IP)层，GTP-U层；用户设备，例如UE，所对应的协议栈包括物理层(physical,PHY)，层2(如，层2包括媒体接入控制(media access control，MAC)层、无线链路控制(radio link control，RLC)层、分组数据汇聚层协议(packet data convergence protocol，PDCP)层、业务数据适应协议(Service Data Adaptation Protocol,SDAP)层)，协议数据单元(Protocol Data Unit,PDU)层，应用层。
如图6所示，对于下行传输，UPF设备需要针对发送给源基站和目标基站的备份数据包，生成QoS flow粒度的序列号，由于QoS flow可以是数据无线承载(Data Radio Bearer，DRB)粒度的，即只有一个QoS flow可以映射到同一个DRB，不同的QoS flow映射到不同的DRB，因此，也可以理解为，对于下行传输，UPF设备需要针对发送给源基站和目标基站的备份数据包，生成DRB粒度的序列号，该功能由GTP-U层实现，例如GTP-U层生成GTP-U SN；对于上行传输，UPF设备针对从源基站和目标基站分别接收到的备份数据包，处理QoS flow粒度(或DRB粒度)的序列号，例如，UPF设备的GTP-U层处理GTP-U SN，且GTP-U层可以进行重复包检测、重排序、按序递交等操作。
如图6所示，源基站或目标基站，对于下行传输，需要针对从核心网设备接收到的备份数据包，处理QoS flow粒度(或DRB粒度)的序列号；对于上行传输，源基站或目标基站，针对从UE接收到的备份数据包，生成QoS flow粒度(或DRB粒度)的序列号。具体的，对于下行传输，源基站或者目标基站接收到UPF设备发送的备份数据包，源基站的PDCP层根据备份数据包的报头中包含的GTP-U SN，确定接收到的备份数据包所对应的PDCP SN，且源基站可以确定出GTP-U SN与PDCP SN的映射关系，而且，目标基站的PDCP层可以根据备份数据包的报头中包含的GTP-U SN，以及GTP-U SN与PDCP SN的映射关系(如，目标基站接收到源基站发送的GTP-U SN与PDCP SN的映射关系)确定接收到的备份数据包所对应的PDCP SN；对于上行传输，源基站或者目标基站接收到UE发送的备份数据包，源基站根据备份数据包的报头中包含的PDCP SN，确定接收到的备份数据包所对应的GTP-U SN，例如该GTP-U SN可以由图6所示的协议层，即GTP-U层生成，且源基站可以确定出GTP-U SN与PDCP SN的映射关系，而且，目标基站可以根据备份数据包的报头中包含的PDCP SN，以及GTP-U SN与PDCP SN的映射关系(如，目标基站接收到源基站发送的GTP-U SN与PDCP SN的映射关系)确定接收到的备份数据包所对应的GTP-U SN，如GTP-U SN可以由GTP-U层生成。
如图6所示，对于下行传输，UE需要针对从源基站以及目标基站分别接收到的备份数据包，进行重复包检测、重排序、按序递交等操作，例如UE的PDCP层进行重 复包检测、重排序、按序递交等操作；对于上行传输，UE生成备份数据包分别发送给源基站以及目标基站，例如UE的PDCP层可以生成备份数据包。
针对图6的一种变形的协议栈，如图7所示。具体的，核心网设备，例如UPF设备，所对应的协议栈包括PHY层，层2(如，层2包括MAC层、RLC层、PDCP层、SDAP层)，UDP/IP层，GTP-U层，HRP层，PDU层；接入网设备，例如源基站或者目标基站，所对应的协议栈包括PHY层，层2(如，层2包括MAC层、RLC层、PDCP层、SDAP层)，UDP/IP层，GTP-U层，HRP层；用户设备，例如UE，所对应的协议栈包括PHY层，层2(如，层2包括MAC层、RLC层、PDCP层、SDAP层)，PDU层，应用层。即，区别于图6所示的协议栈结构，图7所示的协议栈架构下，基站的GTP-U层之上引入一个新层(如，HRP层)，该HRP层可以生成/处理QoS flow粒度(或者说是DRB粒度)的序列号，例如，基站的HRP层可以生成/处理HRP SN；并且，图7所示的协议栈架构下，UPF设备的GTP-U层之上引入一个新层(如，HRP层)，该HRP层可以生成/处理QoS flow粒度(或者说是DRB粒度)的序列号，例如，UPF设备的HRP层可以生成/处理HRP SN。
如图7所示，对于下行传输，UPF设备需要针对发送给源基站和目标基站的备份数据包，生成QoS flow粒度(或DRB粒度)的序列号，该功能由HRP层实现，例如UPF设备的HRP层生成HRP SN；对于上行传输，UPF设备针对从源基站和目标基站分别接收到的备份数据包，处理QoS flow粒度(或DRB粒度)的序列号，例如，UPF设备的HRP层处理HRP SN，且UPF设备的HRP层根据数据包报头中包含的HRP SN进行重复包检测、重排序、按序递交等操作。
如图7所示，源基站或目标基站，对于下行传输，需要针对从核心网设备接收到的备份数据包，处理QoS flow粒度(或DRB粒度)的序列号；对于上行传输，源基站或目标基站，针对从UE接收到的备份数据包，生成QoS flow粒度(或DRB粒度)的序列号。具体的，对于下行传输，源基站或者目标基站接收到UPF设备发送的备份数据包，源基站的PDCP层根据备份数据包的报头中包含的HRPSN，确定接收到的备份数据包所对应的PDCP SN，且源基站可以确定出HRP SN与PDCP SN的映射关系；目标基站的PDCP层可以根据备份数据包的报头中包含的HRP SN，以及HRP SN与PDCP SN的映射关系(目标基站可以从源基站接收HRP SN与PDCP SN的映射关系)确定接收到的备份数据包所对应的PDCP SN；对于上行传输，源基站或者目标基站接收到UE发送的备份数据包，源基站根据备份数据包的报头中包含的PDCP SN，确定接收到的备份数据包所对应的HRP SN，例如该序列号可以由HRP层生成，源基站可以确定出HRP SN与PDCP SN的映射关系，而且，目标基站可以根据备份数据包的报头中包含的PDCP SN，以及HRP SN与PDCP SN的映射关系(目标基站可以从源基站接收HRP SN与PDCP SN的映射关系)确定接收到的备份数据包所对应的HRP SN，如该序列号可以由HRP层生成。
如图7所示，对于下行传输，UE需要针对从源基站以及目标基站分别接收到的备份数据包，进行重复包检测、重排序、按序递交等操作，例如UE的PDCP层可以进行重复包检测、重排序、按序递交等操作；对于上行传输，UE生成备份数据包分别发送给源基站以及目标基站，例如UE的PDCP层可以生成备份数据包。
对于上文中的任一实施例，另一种实现方式中，对应的用户面协议栈架构也可以如图8所示，具体的，核心网设备，例如UPF设备，所对应的协议栈包括物理(physical,PHY)层，层2(如，层2包括媒体接入控制(media access control，MAC)层、无线链路控制(radio link control，RLC)层、分组数据汇聚层协议(packet data convergence protocol，PDCP)层、业务数据适应协议(Service Data Adaptation Protocol,SDAP)层)，用户数据报协议/互联网(User Datagram Protocol/Internet Protocol，UDP/IP)层，GTP-U层，HRP层，协议数据单元(Protocol Data Unit,PDU)层；接入网设备，例如源基站或者目标基站，所对应的协议栈包括物理层(physical,PHY)，层2(如，层2包括媒体接入控制(media access control，MAC)层、无线链路控制(radio link control，RLC)层、分组数据汇聚层协议(packet data convergence protocol，PDCP)层、业务数据适应协议(Service Data Adaptation Protocol,SDAP)层)，用户数据报协议/互联网(User Datagram Protocol/Internet Protocol，UDP/IP)层，GTP-U层；用户设备，例如UE，所对应的协议栈包括物理层(physical,PHY)，层2(如，层2包括媒体接入控制(media access control，MAC)层、无线链路控制(radio link control，RLC)层、分组数据汇聚层协议(packet data convergence protocol，PDCP)层、业务数据适应协议(Service Data Adaptation Protocol,SDAP)层)，HRP层，协议数据单元(Protocol Data Unit,PDU)层，应用层。
如图8所示，对于下行传输，UPF设备需要针对发送给源基站和目标基站的备份数据包，生成QoS flow粒度的序列号，由于QoS flow是DRB粒度的，即只有一个QoS flow可以映射到同一个DRB，不同的QoS flow映射到不同的DRB，因此，也可以理解为，对于下行传输，UPF设备需要针对发送给源基站和目标基站的备份数据包，生成DRB粒度的序列号，该功能由HRP层实现，例如，HRP层生成HRP SN；对于上行传输，UPF设备针对从源基站和目标基站分别接收到的备份数据包，处理QoS flow粒度(或DRB粒度)的序列号，例如，HRP层处理HRP SN，且HRP层可以进行重复包检测、重排序、按序递交等操作。
如图8所示，源基站或目标基站，对于下行传输，源基站将从核心网设备接收到的备份数据包发送给用户设备，另外，目标基站也可以将从核心网设备接收到的备份数据包发送给用户设备。对于上行，源基站将从用户设备接收到的备份数据包发送给UPF设备，且目标基站也将从用户设备接收到的备份数据包发送给UPF设备。需要说明的是，图8所示的协议栈架构中，HRP层对源基站(或目标基站)是透明的，即基站不需要处理QoS flow粒度(或DRB粒度)的序列号，即对于DL，基站不需要处理从UPF设备接收到的数据包中包含的HRP SN；对应UL，基站不需要处理从UE接收到的数据包中包含的HRP SN。
如图8所示，对于用户设备而言，对于下行传输，需要针对从源基站以及目标基站分别接收到的备份数据包，UE进行重复包检测、重排序、按序递交等操作，如UE的HRP层进行重复包检测、重排序、按序递交等操作；对于上行传输，UE生成备份数据包分别发送给源基站以及目标基站，例如，UE的HRP层进行数据包备份且UE将备份数据包分别发送给源基站和目标基站，UE分别发送给源基站以及目标基站的备份数据包的报头中均包含HRP SN。
针对图8的一种变形的协议栈，如图9所示。具体的，核心网设备，例如UPF设备，所对应的协议栈包括PHY层，层2(如，层2包括MAC层、RLC层、PDCP层、SDAP层)，UDP/IP层，GTP-U层，HRP层，PDU层；接入网设备，例如源基站或者目标基站，所对应的协议栈包括PHY层，层2(如，层2包括MAC层、RLC层、PDCP层、SDAP层)，UDP/IP层，GTP-U层，HRP层；用户设备，例如UE，所对应的协议栈包括PHY层，层2(如，层2包括MAC层、RLC层、PDCP层、SDAP层)，HRP层，PDU层，应用层。即，区别于图8所示的协议栈结构，图9所示的协议栈架构下，基站的GTP-U层之上引入一个新层(如，HRP层)，该HRP层可以生成/处理QoS flow粒度(或者是DRB粒度)的编号，例如，基站的HRP层可以生成/处理HRP SN。
如图9所示，对于下行传输，UPF设备需要针对发送给源基站和目标基站的备份数据包，生成QoS flow粒度(或DRB粒度)的序列号，该功能可以由HRP层和/或GTP-U层实现，例如，UPF设备给源基站以及目标基站分别发送的备份数据包的GTP-U报头中包含GTP-U SN，和/或，UPF设备给源基站以及目标基站分别发送的备份数据包的HRP报头中包含HRP SN；对于上行传输，UPF设备针对从源基站和目标基站分别接收到的备份数据包，处理QoS flow粒度(或DRB粒度)的序列号，例如，UPF设备的HRP层处理HRP SN，且HRP层可以根据HRP SN进行重复包检测、重排序、按序递交等操作；或者，对于上行传输，UPF设备的GTP-U层处理GTP-U SN，且UPF设备的GTP-U层可以根据GTP-U SN进行重复包检测、重排序、按序递交等操作。
如图9所示，源基站或目标基站，对于下行传输，需要针对从核心网设备接收到的备份数据包，处理QoS flow粒度(或DRB粒度)的序列号；对于上行传输，源基站或目标基站，针对从UE接收到的备份数据包，生成QoS flow粒度(或DRB粒度)的序列号。具体的，对于下行传输，源基站或者目标基站接收到UPF设备发送的备份数据包，一种实现方式中，源基站的PDCP层根据备份数据包的报头中包含的HRP SN，确定接收到的备份数据包所对应的PDCP SN，且源基站可以确定出HRP SN与PDCP SN的映射关系，或者，另一种实现方式中，源基站的PDCP层根据备份数据包的报头中包含的GTP-U SN，确定接收到的备份数据包所对应的PDCP SN，且源基站可以确定出GTP-U SN与PDCP SN的映射关系；而且，一种实现方式中，目标基站的PDCP层可以根据备份数据包的报头中包含的HRP SN，以及HRP SN与PDCP SN的映射关系(目标基站可以从源基站接收HRP SN与PDCP SN的映射关系)确定接收到的备份数据包所对应的PDCP SN，或者，另一种实现方式中，目标基站的PDCP层根据备份数据包的报头中包含的GTP-U SN，以及GTP-U SN与PDCP SN的映射关系(目标基站可以从源基站接收GTP-U SN与PDCP SN的映射关系)确定接收到的备份数据包所对应的PDCP SN；对于上行传输，源基站或者目标基站接收到UE发送的备份数据包，一种实现方式中，源基站根据备份数据包的报头中包含的PDCP SN，确定接收到的备份数据包所对应的HRP SN，且源基站可以确定出HRP SN与PDCP SN的映射关系，或者，另一种实现方式中，源基站根据备份数据包的报头中包含的PDCP SN，确定接收到的备份数据包所对应的GTP-U SN，且源基站可以确定出GTP-U SN与PDCP SN的映射关系；一种实现方式中，目标基站可以根据备份数据包的报头中包含的PDCP SN，以及HRP SN与PDCP SN的映射关系(目标基站可以从源基站接收HRP SN与PDCP  SN的映射关系)确定接收到的备份数据包所对应的HRP SN，或者，另一种实现方式中，目标基站可以根据备份数据包的报头中包含的PDCP SN，以及GTP-U SN与PDCP SN的映射关系(目标基站可以从源基站接收GTP-U SN与PDCP SN的映射关系)确定接收到的备份数据包所对应的GTP-U SN。
如图9所示，对于下行传输，UE需要针对从源基站以及目标基站分别接收到的备份数据包，进行重复包检测、重排序、按序递交等操作，一种实现方式中，UE的HRP层进行重复包检测、重排序、按序递交等操作，或者，另一种实现方式中，UE的PDCP层进行重复包检测、重排序、按序递交等操作；对于上行传输，UE生成备份数据包分别发送给源基站以及目标基站，例如，UE的HRP层进行数据包备份且UE将备份数据包分别发送给源基站和目标基站，UE分别发送给源基站以及目标基站的备份数据包的报头中均包含HRP SN。
前文实施例的方案，可以单独应用到一个通信系统中，也可以两个方案或多个方案组合应用到一个通信系统中。
相应于上述方法实施例给出的通信方法，本申请实施例还提供了相应的通信装置(有时也称为通信设备)，所述通信装置包括用于执行上述实施例中每个部分相应的模块或单元。所述模块或单元可以是软件，也可以是硬件，或者是软件和硬件结合。
图10示出一种基站的结构示意图，该基站可应用于如图1所示的系统。该基站可以作为UE的源基站，和/或作为UE的目标基站。所述基站包括一个或多个远端射频单元(remote radio unit,RRU)701和一个或多个基带单元(baseband unit，BBU)702。RRU701可以称为收发单元、收发机、收发电路或者收发器等等，其可以包括至少一个天线7011和射频单元7012。RRU701分主要用于射频信号的收发以及射频信号与基带信号的转换，例如用于向终端发送上述实施例中的信令指示或参考信号。BBU702部分主要用于进行基带处理，对基站进行控制等。RRU701与BBU702可以是可以是物理上设置在一起，也可以物理上分离设置的，即分布式基站。
BBU702为基站的控制中心，也可以称为处理单元，主要用于完成基带处理功能，如信道编码，复用，调制，扩频等等。在一个示例中，BBU702可以由一个或多个单板构成，多个单板可以共同支持单一接入制式的无线接入网(如5G网络)，也可以分别支持不同接入制式的无线接入网。BBU702还包括存储器7021和处理器7022。存储器7021用以存储必要的指令和数据。处理器7022用于控制基站进行必要的动作。存储器7021和处理器7022可以服务于一个或多个单板。也就是说，可以每个单板上单独设置存储器和处理器。也可以是多个单板公用相同的存储器和处理器。此外每个单板上还设置有必要的电路。
上述基站可以用于实现前述方法实施例的方法，例如可以实现前文方法实施例中源基站或目标基站的功能。
在一种可能的设计方案中，所述基站可以包括一个或多个处理器，所述处理器也可以称为处理单元，可以实现一定的控制功能。所述处理器可以是通用处理器或者专用处理器等。例如可以是基带处理器或中央处理器。基带处理器可以用于对通信协议以及通信数据进行处理，中央处理器可以用于对通信装置(如，基站、基带芯片，分 布单元(distributed unit,DU)或集中单元(centralized unit，CU)等)进行控制，执行软件程序，处理软件程序的数据。在一种实现方式中，所述处理器存有指令，所述指令可以被所述处理器运行，使得所述基站执行上述方法实施例中描述的方法。在另一中实现方式中，所述基站包括一个或多个存储器，其上存有指令或代码，所述指令或代码可在所述处理器上被运行，使得所述基站执行上述方法实施例中描述的方法。可选的，所述存储器中还可以存储有数据。可选的，处理器中也可以存储指令和/或数据。所述处理器和存储器可以单独设置，也可以集成在一起。
在另一种实可能的设计方案中，所述基站包括电路，所述电路可以实现前述方法实施例中发送或接收或者通信的功能。
例如，对应实施例一，本发明实施例提供了一种目标基站，如图11所示，包括：
接收单元1101，用于接收来自于源基站的切换请求消息；
发送单元1102，用于响应于所述切换请求消息向第一核心网设备发送请求消息，以请求第一数据包的副本，所述第一数据包为第二核心网设备向所述源基站发送的用于用户设备UE的数据包，其中所述第一核心网设备与所述第二核心网设备是相同的核心网设备，或者是不同的核心网设备。
可选的，所述接收单元，还用于接收所述请求消息的确认消息；所述发送单元，还用于向所述源基站发送切换请求确认消息。
可选的，所述接收单元，用于接收来自于所述第二核心网设备的所述第一数据包的副本。
可选的，所述发送单元，还用于响应于所述第一数据包向所述UE发送第三数据包。
可选的，所述发送单元，还用于响应于所述第一数据包的副本向所述UE发送第四数据包。
可选的，所述第一数据包和所述第一数据包的副本分别包括第一索引。
可选的，所述第三数据包和所述第四数据包分别包括第二索引。
本实施例中的接收单元或发送单元，可以由多个子单元构成，分别用于接收或发送不同的数据或信令。
图12提供了一种终端的结构示意图。该终端可适用于图1所示出的系统中。为了便于说明，图12仅示出了终端的主要部件。如图12所示，终端10包括处理器、存储器、控制电路或天线以及输入输出装置。处理器主要用于对通信协议以及通信数据进行处理，以及对整个终端进行控制，执行软件程序，处理软件程序的数据。存储器主要用于存储软件程序和数据，例如存储上述实施例中所描述的码本。控制电路主要用于基带信号与射频信号的转换以及对射频信号的处理。控制电路和天线一起也可以叫做收发器，主要用于收发电磁波形式的射频信号。具输入输出装置，例如触摸屏、显示屏或键盘等主要用于接收用户输入的数据以及对用户输出数据。
当终端开机后，处理器可以读取存储单元中的软件程序，解释并执行软件程序的指令，处理软件程序的数据。当需要通过无线发送数据时，处理器对待发送的数据进行基带处理后，输出基带信号至射频电路，射频电路将基带信号进行射频处理后将射频信号通过天线以电磁波的形式向外发送。当有数据发送到终端时，射频电路通过天 线接收到射频信号，将射频信号转换为基带信号，并将基带信号输出至处理器，处理器将基带信号转换为数据并对该数据进行处理。
本领域技术人员可以理解，为了便于说明，图12仅示出了一个存储器和处理器。在实际的终端中，可以存在多个处理器和存储器。存储器也可以称为存储介质或者存储设备等，本发明实施例对此不做限制。
作为一种可选的实现方式，处理器可以包括基带处理器和中央处理器，基带处理器主要用于对通信协议以及通信数据进行处理，中央处理器主要用于对整个终端进行控制，执行软件程序，处理软件程序的数据。图12中的处理器集成了基带处理器和中央处理器的功能，本领域技术人员可以理解，基带处理器和中央处理器也可以是各自独立的处理器，通过总线等技术互联。本领域技术人员可以理解，终端可以包括多个基带处理器以适应不同的网络制式，终端可以包括多个中央处理器以增强其处理能力，终端的各个部件可以通过各种总线连接。基带处理器也可以表述为基带处理电路或者基带处理芯片。中央处理器也可以表述为中央处理电路或者中央处理芯片。对通信协议以及通信数据进行处理的功能可以内置在处理器中，也可以以软件程序的形式存储在存储单元中，由处理器执行软件程序以实现基带处理功能。
例如，在发明实施例中，可以将具有收发功能的天线和控制电路视为终端10的收发单元801，将具有处理功能的处理器视为终端10的处理单元802。如图12所示，终端10包括收发单元801和处理单元802。收发单元也可以称为收发器、收发机或收发装置等。可选的，可以将收发单元801中用于实现接收功能的器件视为接收单元，将收发单元801中用于实现发送功能的器件视为发送单元，即收发单元801包括接收单元和发送单元示例性的，接收单元也可以称为接收机、接收器或接收电路等，发送单元可以称为发射机、发射器或者发射电路等。
上述用户设备可以用于实现前述实施例中的方法。
虽然在以上的实施例描述中,通信装置以基站或者终端设备为例来描述,但本申请中描述的通信装置的范围并不限于此,而且通信装置的结构可以不受限制。通信装置可以是独立的设备或者可以是较大设备的一部分。例如所述设备可以是：独立的集成电路IC，或芯片，或，芯片系统或子系统；具有一个或多个IC的集合；专用集成电路ASIC，例如调制解调器(modem)；可嵌入在其他设备内的模块等。
对应前文中的实施例三，本发明实施例提供了一种用户设备UE，如图13所示，包括：
发送单元1301，用于向源基站发送数据包P1，P2……PN；
所述发送单元，还用于向目标基站发送数据包Pi至PN，其中数据包Pi为数据包P1至PN中未被所述源基站正确接收的第一个数据包，N为大于等于1的整数，i为大于等于1且小于等于N的整数。
可选的，所述数据包P1至PN的索引是连续且递增的。
可选的，所述UE还包括接收单元1302，用于在所述发送单元向所述目标基站发送Pi至PN之前，接收来自于所述源基站的指示信息，所述指示信息指示所述UE向所述目标基站发送数据包Pi至PN。
可选的，所述指示信息包括在无线资源控制RRC重配置消息中。
可选的，所述UE还包括处理单元1303，用于在所述发送单元向所述目标基站发送所述数据包Pi至PN之前，如果所述UE未收到来自于所述源基站的针对所述数据包Pi的响应，或者接收到来自于所述源基站的针对所述数据包Pi的否定确认NACK，且接收到所述数据包P1至PN中Pi之前的数据包的确认ACK，则确定所述数据包Pi为所述数据包P1至PN中未被所述源基站正确接收的第一个数据包。
本实施例中的接收单元或发送单元，可以由多个子单元构成，分别用于接收或发送不同的数据或信令。
对应实施例一，本发明实施例还提供了一种通信系统，包括源基站和目标基站：
所述源基站，用于接收来自于核心网设备的第一数据包；
目标基站，用于接收来自于所述核心网设备的第二数据包，所述第二数据包是所述第一数据包的副本，所述第一数据包与所述第二数据包分别包括第一索引；
所述源基站，还用于向所述目标基站发送第一指示信息，所述第一指示信息指示所述第一索引与第二索引的映射关系；
所述源基站，还用于响应于所述第一数据包，向用户设备UE发送第三数据包；
所述目标基站，还用于响应于所述第二数据包，向所述UE发送第四数据包，所述第三数据包和所述第四数据包分别包括所述第二索引。
可选的，所述源基站，还用于接收来自于所述核心网设备的第二指示信息；
所述源基站，还用于响应于所述第二指示信息，根据所述第一索引，确定出所述第一索引与所述第二索引的映射关系。
可选的，所述第二指示信息包括在所述第一数据包内。
可选的，所述源基站，还用于接收来自于所述UE的第五数据包；
所述目标基站，还用于接收来自于所述UE的第六数据包，所述第六数据是所述第五数据包的副本，所述第五数据包与所述第六数据包分别包括第三索引；
所述源基站，还用于响应于所述第五数据包，向所述核心网设备发送第七数据包；
所述目标基站，还用于相应于所述第六数据包，向所述核心网设备发送第八数据包，所述第七数据包与所述第八数据包分别包括第四索引。
可选的，所述源基站，还用于向所述目标基站发送第三指示信息，所述第三指示信息指示所述第三索引与所述第四索引的映射关系。
可选的，所述源基站，还用于接收来自于所述UE的第四指示信息；
所述源基站，还用于响应于第四指示信息，根据所述第三索引，确定出所述第三索引与所述第四索引的映射关系。
可选的，所述第四指示信息包括在所述第五数据包内。
对应前文实施例三，本发明实施例还提供了一种通信系统，包括源基站和目标基站：
所述目标基站，用于接收来自于所述用户设备的数据包Pi至PN，所述数据包Pi为用户设备向源基站发送的数据包P1至PN中，未被所述源基站正确接收的第一个数 据包，N为大于等于1的整数，i为大于等于1且小于等于N的整数；
所述目标基站，还用于向核心网设备发送数据包Pi至PN；
所述源基站，用于向所述核心网设备发送所述数据包P1至PN中所述数据包Pi之前的数据包。
可选的，所述数据包P1至PN的索引是连续且递增的。
可选的，在所述目标基站接收所述数据包Pi至PN之前，所述目标基站，还用于向所述源基站发送指示信息，所述指示信息指示所述用户设备向所述目标基站发送所述数据包Pi至PN。
对应前文实施例三，本发明实施例还提供了另外一种通信系统，包括源基站和目标基站：
所述源基站，用于接收来自于用户设备的第一组数据包；
所述目标基站，用于接收来自于所述用户设备的第二组数据包，所述第一组数据包为所述用户设备向所述源基站发送的数据包中被所述源基站正确接收的数据包，第二组数据包是所述用户设备向所述源基站发送的所述数据包中未被所述源基站正确接收的数据包的重传数据包；
所述源基站，还用于向核心网设备发送所述第一组数据包；
所述目标基站，还用于向所述核心网设备发送所述第二组数据包。
可选的，所述第一组数据包为索引不连续的数据包。
本发明实施例还提供一种核心网设备，用于实现前文方法实施例中核心网设备的功能。本发明实施例提供的核心网设备可以由多个设备组成。该核心网设备可以包括存储器、处理器、收发电路等。
需要说明的是，本发明实施例中的“第一”、“第二”、“第三”等编号，仅仅是为了在一个实施例中区分具有相同名称的多个名词，并不表示次序或设备处理的顺序。不同实施例中具有不同编号的名词，可能具有相同的含义；不同实施例中具有相同编号的名词，也可能具有不同的含义。具体含义要根据具体方案确定。
本申请中对于使用单数表示的元素旨在用于表示“一个或多个”，而并非表示“一个且仅一个”，除非有特别说明。“一些”是指一个或多个。“至少一个”是指一个或者多个，“多个”是指两个或两个以上。“和/或”，描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B的情况，其中A,B可以是单数或者复数。字符“/”一般表示前后关联对象是一种“或”的关系。“以下至少一项(个)”或其类似表达，是指的这些项中的任意组合，包括单项(个)或复数项(个)的任意组合。例如，a,b,或c中的至少一项(个)，可以表示：a,b,c,a-b,a-c,b-c,或a-b-c，其中a,b,c可以是单个，也可以是多个。
在上述实施例中，可以全部或部分地通过软件、硬件、固件或者其任意组合来实现。当使用软件实现时，可以全部或部分地以计算机程序产品的形式实现。所述计算机程序产品包括一个或多个计算机指令。在计算机上加载和执行所述计算机程序指令时，全部或部分地产生按照本发明实施例所述的流程或功能。所述计算机可以是通用 计算机、专用计算机、计算机网络、或者其他可编程装置。所述计算机指令可以存储在计算机可读存储介质中，或者从一个计算机可读存储介质向另一个计算机可读存储介质传输，例如，所述计算机指令可以从一个网站站点、计算机、服务器或数据中心通过有线(例如同轴电缆、光纤、数字用户线(DSL))或无线(例如红外、无线、微波等)方式向另一个网站站点、计算机、服务器或数据中心进行传输。所述计算机可读存储介质可以是计算机能够存取的任何可用介质或者是包含一个或多个可用介质集成的服务器、数据中心等数据存储设备。所述可用介质可以是磁性介质，(例如，软盘、硬盘、磁带)、光介质(例如，DVD)、或者半导体介质(例如固态硬盘Solid State Disk(SSD))等。

Claims (32)

  1. 一种通信方法，其特征在于，包括：
    源基站接收来自于核心网设备的第一数据包；
    目标基站接收来自于所述核心网设备的第二数据包，所述第二数据包是所述第一数据包的副本，所述第一数据包与所述第二数据包分别包括第一索引；
    所述源基站向所述目标基站发送第一指示信息，所述第一指示信息指示所述第一索引与第二索引的映射关系；
    所述源基站，响应于所述第一数据包，向用户设备UE发送第三数据包；
    所述目标基站，响应于所述第二数据包，向所述UE发送第四数据包，所述第三数据包和所述第四数据包分别包括所述第二索引。
  2. 根据权利要求1所述的方法，其特征在于，所述方法还包括：
    所述源基站接收来自于所述核心网设备的第二指示信息；
    响应于所述第二指示信息，所述源基站根据所述第一索引，确定所述第一索引与所述第二索引的映射关系。
  3. 根据权利要求2所述的方法，其特征在于，所述第二指示信息包括在所述第一数据包内。
  4. 根据权利要求1-3任一项所述的方法，所述方法还包括：
    所述源基站接收来自于所述UE的第五数据包；
    所述目标基站接收来自于所述UE的第六数据包，所述第六数据是所述第五数据包的副本，所述第五数据包与所述第六数据包分别包括第三索引；
    所述源基站，响应于所述第五数据包，向所述核心网设备发送第七数据包；
    所述目标基站，相应于所述第六数据包，向所述核心网设备发送第八数据包，所述第七数据包与所述第八数据包分别包括第四索引。
  5. 根据权利要求4所述的方法，其特征在于，所述方法还包括：
    所述源基站向所述目标基站发送第三指示信息，所述第三指示信息指示所述第三索引与所述第四索引的映射关系。
  6. 根据权利要求5所述的方法，其特征在于，所述方法还包括：
    所述源基站接收来自于所述UE的第四指示信息；
    响应于第四指示信息，所述源基站根据所述第三索引，确定所述第三索引与所述第四索引的映射关系。
  7. 根据权利要求6所述的方法，其特征在于，所述第四指示信息包括在所述第五数据包内。
  8. 根据权利要求1所述的方法，其特征在于：
    所述第一指示信息包括所述第一索引的值以及与所述第一索引对应的所述第二索引的值。
  9. 根据权利要求1所述的所述的方法，其特征在于：
    所述第一指示信息包括所述第一索引和与所述第一索引对应的所述第二索引的映射公式。
  10. 根据权利要求1所述的方法，其特征在于：
    所述第一指示信息包括所述第一索引的值和与所述第一索引对应的所述第二索引的值的差值。
  11. 一种通信系统，包括源基站和目标基站，其特征在于：
    所述源基站，用于接收来自于核心网设备的第一数据包；
    所述目标基站，用于接收来自于所述核心网设备的第二数据包，所述第二数据包是所述第一数据包的副本，所述第一数据包与所述第二数据包分别包括第一索引；
    所述源基站，还用于向所述目标基站发送第一指示信息，所述第一指示信息指示所述第一索引与第二索引的映射关系；
    所述源基站，还用于响应于所述第一数据包，向用户设备UE发送第三数据包；
    所述目标基站，还用于响应于所述第二数据包，向所述UE发送第四数据包，所述第三数据包和所述第四数据包分别包括所述第二索引。
  12. 根据权利要求11所述的通信系统，其特征在于：
    所述源基站，还用于接收来自于所述核心网设备的第二指示信息；
    所述源基站，还用于响应于所述第二指示信息，根据所述第一索引，确定所述第一索引与所述第二索引的映射关系。
  13. 根据权利要求12所述的通信系统，其特征在于，所述第二指示信息包括在所述第一数据包内。
  14. 根据权利要求11-13任一项所述的通信系统，其特征在于：
    所述源基站，还用于接收来自于所述UE的第五数据包；
    所述目标基站，还用于接收来自于所述UE的第六数据包，所述第六数据是所述第五数据包的副本，所述第五数据包与所述第六数据包分别包括第三索引；
    所述源基站，还用于响应于所述第五数据包，向所述核心网设备发送第七数据包；
    所述目标基站，还用于相应于所述第六数据包，向所述核心网设备发送第八数据包，所述第七数据包与所述第八数据包分别包括第四索引。
  15. 根据权利要求14所述的通信系统，其特征在于：
    所述源基站，还用于向所述目标基站发送第三指示信息，所述第三指示信息指示所述第三索引与所述第四索引的映射关系。
  16. 根据权利要求15所述的通信系统，其特征在于：
    所述源基站，还用于接收来自于所述UE的第四指示信息；
    所述源基站，还用于响应于第四指示信息，根据所述第三索引，确定所述第三索引与所述第四索引的映射关系。
  17. 根据权利要求16所述的通信系统，其特征在于，所述第四指示信息包括在所述第五数据包内。
  18. 根据权利要求11所述的通信系统，其特征在于：
    所述第一指示信息包括所述第一索引的值以及与所述第一索引对应的所述第二索引的值。
  19. 根据权利要求11所述的所述的通信系统，其特征在于：
    所述第一指示信息包括所述第一索引和与所述第一索引对应的所述第二索引的映射公式。
  20. 根据权利要求11所述的通信系统，其特征在于：
    所述第一指示信息包括所述第一索引的值和与所述第一索引对应的所述第二索引的值的差值。
  21. 一种用于用户设备UE的目标基站中的通信装置，其特征在于，包括：
    接收单元，用于接收来自于源基站的切换请求消息；
    发送单元，用于响应于所述切换请求消息向第一核心网设备发送请求消息，以请求第一数据包的副本，所述第一数据包为第二核心网设备向所述源基站发送的用于用户设备UE的数据包，其中所述第一核心网设备与所述第二核心网设备是相同的核心网设备，或者是不同的核心网设备。
  22. 根据权利要求21所述的通信装置，其特征在于：
    所述接收单元，还用于接收所述请求消息的确认消息；
    所述发送单元，还用于向所述源基站发送切换请求确认消息。
  23. 根据权利要求21或22所述的通信装置，其特征在于：
    所述接收单元，用于接收来自于所述第二核心网设备的所述第一数据包的副本。
  24. 根据权利要求21至23任一项所述的目标基站，其特征在于：
    所述发送单元，还用于响应于所述第一数据包向所述UE发送第三数据包。
  25. 根据权利要求21至24任一项所述的通信装置，其特征在于：
    所述发送单元，还用于响应于所述第一数据包的副本向所述UE发送第四数据包。
  26. 根据权利要求21至25任一项所述的通信装置，其特征在于，所述第一数据包和所述第一数据包的副本分别包括第一索引。
  27. 根据权利要求21至26任一项所述的通信装置，其特征在于，所述第三数据包和所述第四数据包分别包括第二索引。
  28. 一种通信装置，其特征在于，包括：
    发送单元，用于向源基站发送数据包P 1，P 2……P N；
    所述发送单元，还用于向目标基站发送数据包P i至P N，其中数据包P i为数据包P 1至P N中未被所述源基站正确接收的第一个数据包，N为大于等于1的整数，i为大于等于1且小于等于N的整数。
  29. 根据权利要求28所述的通信装置，其特征在于，所述数据包P 1至P N的索引是连续且递增的。
  30. 根据权利要求29所述的通信装置，其特征在于，还包括接收单元，用于在所述发送单元向所述目标基站发送P i至P N之前，接收来自于所述源基站的指示信息，所述指示信息指示所述UE向所述目标基站发送数据包P i至P N。
  31. 根据权利要求30所述的通信装置，所述指示信息包括在无线资源控制RRC重配置消息中。
  32. 根据权利要求28-31任一项所述的通信装置，其特征在于，还包括处理单元，用于在所述发送单元向所述目标基站发送所述数据包P i至P N之前，如果所述UE未收到来自于所述源基站的针对所述数据包P i的响应，或者接收到来自于所述源基站的针对所述数据包P i的否定确认NACK，且接收到所述数据包P 1至P N中P i之前的数据包的确认ACK，则确定所述数据包P i为所述数据包P 1至P N中未被所述源基站正确接收的第一个数据包。
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Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102510823B1 (ko) * 2018-08-13 2023-03-16 삼성전자주식회사 이동통신 시스템에서 핸드오버 방법 및 장치
WO2022052104A1 (en) * 2020-09-14 2022-03-17 Lenovo (Beijing) Limited Methods and apparatuses for optimizing an uplink ho interruption

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101888675A (zh) * 2009-05-14 2010-11-17 中兴通讯股份有限公司 一种长期演进系统中跨基站切换方法及系统
CN102065501A (zh) * 2011-01-17 2011-05-18 大唐移动通信设备有限公司 一种小区切换方法和设备
CN103026753A (zh) * 2010-05-28 2013-04-03 三星电子株式会社 在异构无线通信系统中支持移动性的装置和方法
CN103944943A (zh) * 2013-01-22 2014-07-23 中国移动通信集团公司 一种数据传输方法和设备

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8830950B2 (en) * 2007-06-18 2014-09-09 Qualcomm Incorporated Method and apparatus for PDCP reordering at handoff
CN102651892B (zh) * 2007-09-29 2016-03-30 华为技术有限公司 基于s1切换的下行及上行数据包转发方法
CN101784033B (zh) * 2009-01-15 2014-07-09 华为技术有限公司 切换数据转发处理方法、装置和系统
US20100260126A1 (en) * 2009-04-13 2010-10-14 Qualcomm Incorporated Split-cell relay packet routing
CN103796258B (zh) * 2012-10-29 2017-05-10 中兴通讯股份有限公司 通信系统的基站切换方法及系统
CN104301955A (zh) * 2014-09-02 2015-01-21 中兴通讯股份有限公司 一种用户设备切换基站的方法及基站、用户设备
US10244444B2 (en) * 2015-03-04 2019-03-26 Qualcomm Incorporated Dual link handover
CN108616945B (zh) * 2017-02-10 2021-05-11 华为技术有限公司 一种通信链路切换的方法及相关设备
CN108924876B (zh) * 2017-03-24 2024-05-10 华为技术有限公司 数据传输方法、接入网设备、终端及通信系统
US20180367288A1 (en) * 2017-06-16 2018-12-20 Huawei Technologies Co., Ltd. Dynamic activation and deactivation of packet duplication
US11122477B2 (en) * 2018-02-26 2021-09-14 Qualcomm Incorporated User plane function (UPF) duplication based make before break handover
US10834661B2 (en) * 2018-04-27 2020-11-10 Qualcomm Incorporated Multiple connectivity for high reliability
EP3761703B1 (en) * 2018-05-21 2023-06-28 Guangdong Oppo Mobile Telecommunications Corp., Ltd. Session processing method and device, computer storage medium
KR102510823B1 (ko) * 2018-08-13 2023-03-16 삼성전자주식회사 이동통신 시스템에서 핸드오버 방법 및 장치

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101888675A (zh) * 2009-05-14 2010-11-17 中兴通讯股份有限公司 一种长期演进系统中跨基站切换方法及系统
CN103026753A (zh) * 2010-05-28 2013-04-03 三星电子株式会社 在异构无线通信系统中支持移动性的装置和方法
CN102065501A (zh) * 2011-01-17 2011-05-18 大唐移动通信设备有限公司 一种小区切换方法和设备
CN103944943A (zh) * 2013-01-22 2014-07-23 中国移动通信集团公司 一种数据传输方法和设备

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
ANONYMOUS: "3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Study on enhancement of Ultra-Reliable Low-Latency Communication (URLLC) support in the 5G Core network (5GC) (Release 16)", 3GPP STANDARD; TECHNICAL REPORT; 3GPP TR 23.725, 31 December 2018 (2018-12-31), pages 1 - 75, XP051591081 *
See also references of EP3920592A4 *

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