WO2020063867A1 - 一种切换方法及基站 - Google Patents

一种切换方法及基站 Download PDF

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Publication number
WO2020063867A1
WO2020063867A1 PCT/CN2019/108545 CN2019108545W WO2020063867A1 WO 2020063867 A1 WO2020063867 A1 WO 2020063867A1 CN 2019108545 W CN2019108545 W CN 2019108545W WO 2020063867 A1 WO2020063867 A1 WO 2020063867A1
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WO
WIPO (PCT)
Prior art keywords
base station
drb
source base
data unit
qos flow
Prior art date
Application number
PCT/CN2019/108545
Other languages
English (en)
French (fr)
Inventor
胡星星
张宏平
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
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 EP19864117.7A priority Critical patent/EP3836626B1/en
Publication of WO2020063867A1 publication Critical patent/WO2020063867A1/zh
Priority to US17/215,937 priority patent/US11683730B2/en

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    • 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
    • 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
    • H04W36/0033—Control or signalling for completing the hand-off for data sessions of end-to-end connection with transfer of context information
    • 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
    • H04W36/0033—Control or signalling for completing the hand-off for data sessions of end-to-end connection with transfer of context information
    • H04W36/0044—Control or signalling for completing the hand-off for data sessions of end-to-end connection with transfer of context information of quality context information
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W28/00—Network traffic management; Network resource management
    • H04W28/02—Traffic management, e.g. flow control or congestion control
    • 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
    • H04W28/00—Network traffic management; Network resource management
    • H04W28/02—Traffic management, e.g. flow control or congestion control
    • H04W28/0252—Traffic management, e.g. flow control or congestion control per individual bearer or channel
    • H04W28/0263—Traffic management, e.g. flow control or congestion control per individual bearer or channel involving mapping traffic to individual bearers or channels, e.g. traffic flow template [TFT]
    • 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
    • H04W36/023—Buffering or recovering information during reselection
    • H04W36/0235—Buffering or recovering information during reselection by transmitting sequence numbers, e.g. SN status transfer
    • 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
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W92/00—Interfaces specially adapted for wireless communication networks
    • H04W92/16—Interfaces between hierarchically similar devices
    • H04W92/20—Interfaces between hierarchically similar devices between access points

Definitions

  • the present application relates to the field of communications, and in particular, to a handover method and a base station.
  • a fifth generation core network device (5 generation core (5GC)) establishes one or more protocol data unit sessions (PDU sessions) for the UE.
  • the 5G radio access network (NG-RAN) establishes one or more data radio bearers (DRB) for each PDU session.
  • the data bearer (DRB) is the data bearer between the base station and the terminal.
  • QOS Quality of Service
  • the user network function (UPF) of the core network device generates downlink qos flow, and the terminal generates uplink qos flow.
  • the service data adaptation protocol layer (service data adaptation protocol, SDAP) is responsible for mapping the qos flow from the non-access layer to the DRB of the access layer.
  • SDAP service data adaptation protocol
  • This application discloses a switching method to ensure the normal progress of communication.
  • a first aspect of the present application provides a handover method, including:
  • the target base station receives a base station handover request sent by the source base station, where the handover request carries first indication information, and the first indication information may indicate that a radio data bearer DRB corresponding to the quality of service flow qos of the source base station changes from the first DRB to the second
  • the change of the DRB corresponding to the DRB and qos flow from the first DRB to the second DRB indicates that the qos flow changes from being mapped to the first DRB for transmission to be mapped to the second DRB for transmission.
  • the target base station After receiving the handover request, the target base station can know that there is a qos flow on the source base station that needs to be transferred to the target base station, and the DRB corresponding to the qos flow has changed.
  • the target base station sends the tunnel information to the source base station, so that the source base station uses the tunnel to send the corresponding DRB in the qos flow to the second DRB data unit, which is buffered in the SDAP layer of the source base station due to the mapping relationship transition. in.
  • the data unit after the corresponding DRB change in qos flow is the second DRB is the data unit transmitted in the qos flow through the second DRB.
  • the target base station receives a handover request sent by the source base station, and the handover request includes first indication information, which can instruct the DRB corresponding to the qos flow received by the source base station to change from the first DRB to the second DRB,
  • the target base station then sends the tunnel information to the source base station, so that the source base station sends the corresponding DRB change to the data unit after the second DRB through the tunnel.
  • the source base station carries the first indication information in the handover request
  • the target base station can determine, according to the first indication information, that the DRB corresponding to the qos flow that the data unit belongs to changes from the first DRB to the second DRB, so that the target base station
  • the information of the tunnel is sent to the source base station, so that the source base station transfers data units through the tunnel to ensure that the data units in the qos flow are reported in order, thereby ensuring the normal communication of the communication system.
  • the first indication information is used to instruct the wireless data bearer DRB corresponding to the qos flow received by the source base station to change from the first DRB to the second DRB includes:
  • the qos flow sent by the UE to the source base station by mapping to the first DRB is changed to be sent to the source base station by mapping to DRB2.
  • the SDAP layer of the source base station receives the qos in the second DRB After the data units of the flow, these data units are buffered in the SDAP layer of the source base station.
  • the source base station sends the qos flow sent to the UE by mapping to DRB1, and changes to the qos flow sent to the source base station by mapping to DRB2.
  • the source base station buffers the data unit of the qos flow that needs to be sent through DRB2.
  • the SDAP layer of the source base station In the SDAP layer of the source base station.
  • the method further includes:
  • the target base station acquires an end instruction, which is used to instruct the SDAP entity of the UE to stop mapping qos flow to the first DRB.
  • the method for the target base station to obtain the end indication is as follows:
  • One situation is that some data packets in the first data unit sent by the UE to the source base station are not correctly received by the source base station due to changes in the wireless communication channel.
  • the received data packets and the end instruction are transferred to the target base station, and at the same time, the UE will continue to resend these data packets that have not been correctly received by the source base station through the first DRB.
  • the UE will also resend the target base station through the first DRB.
  • the end instruction In another case, the source base station has completely received the first data unit, and the source base station sends the first data unit and the end indication to the target base station.
  • the target base station learns that all data units transmitted through the first DRB have been received according to the instruction information. It can also be learned that the first data unit has been submitted The core network device is given, and then the target base station sends the second data unit to the core network device.
  • the target base station sends the data unit to the core network device after receiving the end instruction, which ensures the sequential submission of the data units in the qos flow.
  • the method further includes:
  • the target base station For downlink data, after the target base station determines that the qos flow mapped to the first DRB is received by the UE, the target base station maps the data unit to the second DRB, thereby sending the data unit to the UE.
  • the determination method may be that when the target base station determines that no qos flow exists on the first DRB, it can be determined that the qos flow mapped to the first DRB is received by the UE.
  • the target base station sends a data unit to the UE again, which ensures that the data units in the qos flow are submitted in order.
  • the tunnel information when the tunnel is a PDU session tunnel, includes qos flow The identifier of the corresponding PDU session of the protocol data unit, so that the source base station determines which PDU session's tunnel information is based on the tunnel information.
  • the source base station by including the PDU session identifier in the tunnel information, it is beneficial for the source base station to determine which PDU session tunnel information is based on the tunnel information.
  • the method further includes:
  • the tunnel is a PDU session tunnel
  • the target base station while the target base station receives the data unit transferred by the source base station, it also needs to receive the second instruction information sent by the source base station, so that the target base station learns that the transferred data unit is buffered in the SDAP layer according to the second instruction information Data units in the SDAP to distinguish them from other data units that are not cached in the SDAP layer.
  • the source base station may also send second instruction information to indicate that the data unit is a data unit buffered in the SDAP layer, which is beneficial to the implementation of the solution.
  • the target base station sends tunnel information to the source base station
  • the method further includes: the target base station assigning an address to the tunnel.
  • the target base station allocates an address for the tunnel, which increases the integrity of the solution.
  • a seventh implementable manner of the first aspect after the target base station receives the handover request sent by the source base station, the method also includes:
  • the target base station when the target base station receives the data unit transferred by the source base station, it also needs to receive the serial number status transfer information sent by the source base station, and the serial number status transfer information includes the PDCP and SN number of the data unit.
  • the source base station will also send the sequence number state transition information of the data unit to the target base station, which increases the implementation of the solution.
  • the SN of the data unit is used by the target base station to determine that the data unit is a data unit buffered in the SDAP layer of the source base station
  • the determined method is that the target base station indicates whether the data unit before the PDCP SN corresponding to the first lost uplink PDCP in the DRB corresponding to the DRB tunnel through the bit string of the PDCP SN number is a data unit buffered in the SDAP layer.
  • the sequence number state transition information includes a PDCP number and a SN number, which may indicate that the data unit is a data unit buffered in the SDAP layer, which is beneficial to the implementation of the solution.
  • a second aspect of the present application provides a handover method, including:
  • the source base station sends a base station handover request to the target base station.
  • the handover request carries first indication information, and the first indication information may indicate that the wireless data bearer DRB corresponding to the quality of service flow qos of the source base station changes from the first DRB to the second DRB.
  • the target base station can know that the mapping relationship between qos flow and DRB has changed according to the first instruction information, it can be known that the buffered qos flow in the SDAP layer of the source base station needs to be transferred to the target base station.
  • the change of the DRB corresponding to qos flow from the first DRB to the second DRB means that qos flow changes from being mapped to the first DRB for transmission to be mapped to the second DRB for transmission.
  • the source base station receives the tunnel information sent by the target base station.
  • the source base station uses the tunnel to send the corresponding DRB in the qos flow to the target base station after the data unit changed to the second DRB.
  • This data unit is buffered in the SDAP layer of the source base station due to the mapping relationship transition.
  • the data unit after the corresponding DRB change in qos flow is the second DRB is the data unit transmitted in the qos flow through the second DRB.
  • the source base station carries the first indication information in the handover request
  • the target base station can determine, according to the first indication information, that the DRB corresponding to the qos flow that the data unit belongs to changes from the first DRB to the second DRB, so that the target base station
  • the information of the tunnel is sent to the source base station, so that the source base station transfers data units through the tunnel to ensure that the data units in the qos flow are reported in order, thereby ensuring the normal communication of the communication system.
  • the first indication information is used to instruct the wireless data bearer DRB corresponding to the qos flow received by the source base station to change from the first DRB to the second DRB includes:
  • the qos flow sent by the UE to the source base station by mapping to the first DRB is changed to be sent to the source base station by mapping to DRB2.
  • the SDAP layer of the source base station receives the qos in the second DRB After the data units of the flow, these data units are buffered in the SDAP layer of the source base station.
  • the source base station sends the qos flow sent to the UE by mapping to DRB1, and changes to the qos flow sent to the source base station by mapping to DRB2.
  • the source base station buffers the data unit of the qos flow that needs to be sent through DRB2.
  • the SDAP layer of the source base station In the SDAP layer of the source base station.
  • the tunnel information when the tunnel is a PDU session tunnel, includes the qos flow The identifier of the corresponding PDU session of the protocol data unit, so that the source base station determines which PDU session's tunnel information is based on the tunnel information.
  • the source base station by including the PDU session identifier in the tunnel information, it is beneficial for the source base station to determine which PDU session tunnel information is based on the tunnel information.
  • the method further includes:
  • the source base station also needs to send the second instruction information to the target base station, so that the target base station learns that the transferred data unit is a data unit buffered in the SDAP layer according to the second instruction information, so as to communicate with other non-cached Data units in the SDAP layer are distinguished.
  • the source base station may also send second instruction information to indicate that the data unit is a data unit buffered in the SDAP layer, which is beneficial to the implementation of the solution.
  • a fourth implementable manner of the second aspect after the source base station receives the tunnel information sent by the target base station, all The method also includes:
  • the source base station while the source base station transfers the data unit, the source base station also needs to send sequence number status transfer information to the target base station, where the sequence number status transfer information includes the PDCP and SN number of the data unit.
  • the source base station will also send the sequence number state transition information of the data unit to the target base station, which increases the implementation of the solution.
  • the SN number of the data unit is used by the target base station to determine that the data unit is a data unit buffered in the SDAP layer of the source base station
  • the determined method is that the target base station indicates whether the data unit before the PDCP SN corresponding to the first lost uplink PDCP in the DRB corresponding to the DRB tunnel through the bit string of the PDCP SN number is a data unit buffered in the SDAP layer.
  • the sequence number state transition information includes a PDCP number and a SN number, which may indicate that the data unit is a data unit buffered in the SDAP layer, which is beneficial to the implementation of the solution.
  • a third aspect of the present application provides an encryption method, including:
  • the core network device sends a selection instruction to the source base station.
  • the selection instruction is specifically an inclination indication.
  • the inclination indication indicates that the base station determines whether to perform encryption.
  • the source base station encrypts or does not encrypt qos flow according to the selection instruction.
  • the source base station sends a handover request message to the target base station.
  • the handover request message is a request to switch some qos in the pdu session to the target base station.
  • the handover request message also carries the source base station operation instruction.
  • the source base station operation instruction is used to instruct the source base station to perform Encryption operation or no encryption operation performed.
  • the target base station encrypts or does not encrypt some qos flows received according to the operation instruction of the source base station.
  • the source base station operation instruction may include a selection instruction and a cell, where the cell is used to indicate that the source base station has encrypted or not encrypted the qos flow; or the source base station operation instruction may also be: the source base station performs a core network operation based on its own operation The encryption instruction sent by the device is modified to require an encryption instruction or an encryption instruction is not required.
  • the source base station if it encrypts the qos flow, it will send an operation instruction of the source base station to the target base station, so that the target base station can perform the corresponding encryption operation according to the operation instruction, ensuring that the encryption operation is performed at the source base station and the target. Base station consistency.
  • a fourth aspect of the present application provides an integrity protection method, including:
  • the core network device sends a selection indication to the source base station.
  • the selection indication is specifically that the selection indication is a tendency towards integrity protection indication.
  • the tendency towards integrity protection indication means that the base station decides whether to perform integrity protection.
  • the source base station performs integrity protection or does not perform integrity protection on qos flow according to the selection instruction.
  • the source base station sends a handover request message to the target base station.
  • the handover request message is a request to switch some qos in the pdu session to the target base station.
  • the handover request message also carries the source base station operation instruction.
  • the source base station operation instruction is used to instruct the source base station to perform Integrity protection operation or no integrity protection operation was performed.
  • the target base station performs integrity protection or does not perform integrity protection on the received QoS according to the operation instruction of the source base station.
  • the operation instruction of the source base station may include a selection instruction and a cell, and the cell is used to indicate that the source base station has performed integrity protection or no integrity protection on the qos flow; or the source base station operation instruction may also be: the source base station The integrity protection indication or the integrity protection indication that is obtained by modifying the integrity protection indication sent by the core network device according to its own operation is required.
  • the source base station if it performs integrity protection on qos flow, it will send an operation instruction of the source base station to the target base station so that the target base station can perform a corresponding integrity protection operation according to the operation instruction, thereby ensuring integrity protection.
  • the operation is consistent at the source base station and the target base station.
  • a fifth aspect of the present application provides a key processing method, including:
  • the user equipment UE receives a first count value sent by the main base station MN, the first count value is a count value of a secondary base station counter SN counter in a first dual-link DC mode, and the first count value is greater than or equal to zero A positive integer, the first DC mode is a DC mode configured by the MN for the UE;
  • the UE When the UE releases the first DC mode, the UE retains the first count value
  • the second count value is a count value of an SN counter in a second DC mode, and the second count value is a positive integer greater than or equal to zero, the The second DC mode is a DC mode configured by the MN for the UE;
  • the UE When the second count value is abnormal, the UE sends configuration failure identification information to the MN.
  • the UE determines whether the second count value is abnormal by using the first count value. If the same count value is configured in the MN, the UE sends configuration failure identification information to the MN to avoid MN derivative in different DC modes. The same S-key is obtained, which ensures the communication security of the air interface.
  • a sixth aspect of the present application provides a key processing method, including:
  • a first count value sent by the primary base station MN to the user equipment UE is a count value of a secondary base station counter SN counter in a first dual-link DC mode, and the first count value is greater than or A positive integer equal to zero, the first DC mode is a DC mode configured by the MN for the UE;
  • a second count value sent by the MN to the UE where the second count value is used by the UE to determine the first count value based on the first count value retained when the UE releases the first DC mode Whether the second count value is abnormal, the second count value is the count value of the SN counter in the second DC mode, and the second count value is a positive integer greater than or equal to zero, and the second DC mode is the MN is a DC mode configured by the UE;
  • the MN receives the configuration failure identification information sent by the MN.
  • the MN sends the first count value to the UE. After the MN sends the second count value to the UE, the UE can determine whether the second count value is abnormal according to the first count value, so the UE sends a configuration failure indicator. Information is sent to the MN to avoid that in different DC modes, the MN derives the same S-key and ensures the communication security of the air interface.
  • a seventh aspect of the present application provides a base station, including:
  • a receiving unit configured to receive a handover request sent by a source base station, where the handover request includes first indication information, where the first indication information is used to instruct a radio data bearer DRB corresponding to a quality of service flow qos flow of the source base station from One DRB changes to a second DRB;
  • a sending unit configured to send information about a tunnel to the source base station, where the tunnel is used by a target base station to receive a data unit sent by the source base station, where the data unit is the DRB change corresponding to the qos flow Is the data unit after the second DRB.
  • the first indication information is used to instruct the wireless data bearer DRB corresponding to the qos flow received by the source base station to change from the first DRB to the second DRB includes:
  • the first indication information is used to indicate that the qos flow received from the user equipment UE received by the source base station changes from mapping to the first DRB to mapping to the second DRB, and the qos flow is Qos flow buffered in the service data adaptation protocol SDAP layer of the source base station due to the corresponding DRB change;
  • the first indication information is used to instruct the qos flow sent by the source base station to the UE to change from mapping to the first DRB to mapping to the second DRB, and the qos flow is due to The qos flow corresponding to the DRB change is buffered in the SDAP layer of the source base station.
  • the receiving unit is further configured to obtain an end instruction, and the end instruction is used for Instructing the SDAP entity of the UE to stop mapping the qos flow to the first DRB;
  • the sending unit is further configured to: After the qos flow is received by the UE, the data unit is sent to the UE through the second DRB.
  • the tunnel information includes a protocol corresponding to the qos flow ID of the data unit PDU session.
  • the receiving unit is further configured to receive second instruction information from the source base station, and the second instruction The information is used by the target base station to determine that the data unit is a data unit buffered in the SDAP layer of the source base station due to a corresponding change in the DRB.
  • the base station further includes:
  • An address allocation unit is configured to allocate an address for the tunnel.
  • the receiving unit is further configured to receive a signal from the source.
  • the serial number status transition information of the base station where the serial number status transition information includes an SN number of the data unit.
  • the SN number of the data unit is used by the target base station to determine that the data unit is due to the corresponding DRB A data unit that is changed and buffered in the SDAP layer of the source base station.
  • An eighth aspect of the present application provides a base station, including:
  • a sending unit configured to send a handover request to a target base station, where the handover request includes first indication information, and the first indication information is used to instruct a radio data bearer DRB corresponding to the quality of service flow qos flow of the source base station from the first DRB changes to the second DRB;
  • a receiving unit configured to receive tunnel information sent by the target base station
  • the sending unit is further configured to send the data unit to the target base station through the tunnel, where the data unit is a data unit after the corresponding DRB in the qos flow is changed to the second DRB.
  • the first indication information is used to instruct the wireless data bearer DRB corresponding to the qos flow received by the source base station to change from the first DRB to the second DRB includes:
  • the first indication information is used to indicate that the qos flow received from the user equipment UE received by the source base station changes from mapping to the first DRB to mapping to the second DRB, and the qos flow is Qos flow buffered in the service data adaptation protocol SDAP layer of the source base station due to the corresponding DRB change;
  • the first indication information is used to instruct the qos flow sent by the source base station to the UE to change from mapping to the first DRB to mapping to the second DRB, and the qos flow is due to The qos flow corresponding to the DRB change is buffered in the SDAP layer of the source base station.
  • the tunnel information includes a protocol data unit PDU session corresponding to the qos flow The ID of the session.
  • the sending unit is further configured to send second instruction information to the target base station, and the second instruction information It is used to indicate that the data unit is a data unit buffered in the SDAP layer of the source base station due to a corresponding change in the DRB.
  • the sending unit is further configured to send serial number state transition information to the eighth aspect.
  • the target base station wherein the sequence number transfer information includes an SN number of the data unit.
  • the SN number of the data unit is used by the target base station to determine that the data unit is due to the corresponding DRB A data unit that is changed and buffered in the SDAP layer of the source base station.
  • a ninth aspect of the present application provides a base station, which includes: a memory, a transceiver, and a processor;
  • the memory is used to store programs and instructions
  • the transceiver is configured to receive or send information under the control of the processor
  • the processor is configured to execute a program in the memory
  • the bus system is configured to connect the memory, the transceiver, and the processor to enable the memory, the transceiver, and the processor to communicate;
  • the processor is configured to call a program instruction in the memory to execute the first aspect, the first aspect to the eighth implementation manner of the first aspect, the second aspect, and the first aspect of the second aspect. And the method described in any one of the fifth implementable manners.
  • the base station further includes a bus system
  • the bus system is configured to connect the memory, the transceiver, and the processor to enable the memory, the transceiver, and the processor to communicate.
  • a tenth aspect of the present application provides a computer-readable storage medium including instructions.
  • the computer When the instructions are run on a computer, the computer is enabled to execute the first aspect, the first aspect, and the eighth aspect of the first aspect.
  • the eleventh aspect of the present application provides a computer program product containing instructions, which, when run on a computer, causes the computer to execute the first aspect, the first aspect to the eighth implementation manner of the first aspect, The method according to the second aspect and any one of the first and fifth implementable aspects of the second aspect.
  • a twelfth aspect of the present application provides a communication chip.
  • the communication chip stores instructions.
  • the communication chip runs on a communication device, the communication chip is configured to execute the communication chip according to the first aspect and the first aspect of the claim.
  • a thirteenth aspect of the present application provides a communication system, including the seventh aspect, the first to eighth implementable manners of the seventh aspect, the eighth aspect, and the first and fifth implementable aspects of the eighth aspect. Any of the modes may implement the device described in the modes.
  • FIG. 1 (a) is a structural diagram of a 5G communication system of the present application
  • FIG. 1 (b) is a schematic diagram of an SDAP entity receiving an uplink data unit when the mapping relationship is changed;
  • FIG. 1 (c) is a schematic diagram of an SDAP entity receiving a downlink data unit when the mapping relationship of this application is changed;
  • FIG. 2 is a schematic diagram of an embodiment of a switching method according to this application.
  • FIG. 3 is a schematic diagram of another embodiment of a switching method according to the present application.
  • FIG. 4 is a schematic diagram of another embodiment of a handover method according to the present application.
  • FIG. 5 is a schematic diagram of another embodiment of a switching method according to the present application.
  • FIG. 6 is a schematic diagram of another embodiment of a switching method according to the present application.
  • FIG. 7 is a schematic diagram of another embodiment of a switching method according to the present application.
  • FIG. 8 (a) is a schematic diagram of another embodiment of a handover method according to the present application.
  • FIG. 8 (b) is a schematic diagram of another embodiment of a handover method according to the present application.
  • FIG. 9 is a schematic diagram of an embodiment of encrypting qos flow in this application.
  • FIG. 10 is a schematic diagram of an embodiment for performing integrity protection on qos flow
  • FIG. 11 is a schematic diagram of an embodiment of a key generation method in a DC scenario of this application.
  • FIG. 14 is another possible structure of a base station of the present application.
  • the structure of the 5G communication system is shown in FIG. 1 (a).
  • the communication system may include a core network (5GC) and an access network (NG-RAN).
  • the core network provides the functions of the 5G core network for the UE.
  • the core network includes a control network element (AMF) function of the core network and a user plane function (UPF) function of the core network.
  • AMF is mainly responsible for terminal access and mobility management.
  • the UPF is mainly responsible for functions such as data packet routing and forwarding, and quality of service (Qos) management.
  • the access network may include a base station to provide wireless access services for the UE.
  • the base station may be a 5G new radio (NR) base station (gNB) connected to NGC.
  • NR 5G new radio
  • This application can be applied to the communication system shown in FIG. 1 (a), and can also be applied to other communication systems. This application does not limit this.
  • the PDU session tunnel indicates a tunnel established for the PDU session
  • the DRB tunnel indicates a tunnel established for each DRB.
  • the qos flow of the source base station is the data stream received from the UE by the source base station, and the uplink qos flow is mapped by the SDAP entity of the UE to the DRB, and then sent to the source base station.
  • the SDAP entity of the UE is mapped by the SDAP entity of the UE to the DRB, and then sent to the source base station.
  • mapping relationship changes during the process of qos flow mapping to DRB, for example, qos flow changes from mapping to DRB1 to mapping to DRB2, the second data unit corresponding to DRB2 in qos flow may reach the source base station first, and qos flow The first data unit corresponding to DRB1 then arrives at the source base station, and the SDAP layer of the source base station buffers the second data unit of qos flow received from DRB2.
  • the SDAP layer on the terminal side plans to map qos flow data units packet_1 / 2/3 and packet_4 / 5/6 to DRB1, and in the SDAP layer, packet_1 / 2/3 After mapping to DRB1, if the mapping relationship between qos flow and DRB is changed at this time, the data unit of qos flow is mapped to DRB2, that is, the SDAP layer changes the data unit packet_4 / 5/6 after qos flow to DRB1. In order to map to DRB2, when the mapping relationship is changed, the data may be out of order.
  • the SDAP layer of the base station may first receive the packet_4 / 5/6 of the qos flow on DRB2, but it has not received packet_1 on DRB1. / 2/3. In this case, the base station will first submit the data unit received first, which will cause the data unit to be delivered out of order. In order to avoid disorder of data units when a base station handover occurs, the present application may report the second data unit packet_4 / 5/6 to the core network device after determining that the first data unit such as packet_1 / 2/3 has been reported to the core network device.
  • the manner in which the SDAP entity of the UE determines that the uplink qos flow changes from DRB1 to DRB2 includes: the UE receives an RRC message from the source base station, which notifies the UE that the mapping relationship between the uplink qos flow and DRB has changed. Or the UE receives a data packet from the base station, and the data packet carries indication information indicating that the mapping relationship between the uplink qos flow and the DRB of the UE has changed.
  • the qos flow of the source base station is the data flow sent by the source base station to the UE, and the qos flow is mapped to the DRB by the SDAP entity of the source base station, and then sent to the UE.
  • the first data unit is a data unit before the second data unit in the qos flow
  • the second data unit is first buffered in the SDAP layer of the source base station.
  • the switching method may include the following steps:
  • the target base station receives a handover request sent by a source base station.
  • the target base station When a base station handover occurs, the target base station first receives a handover request from the source base station.
  • the handover request carries first indication information, and the first indication information is used to indicate that the radio data bearer DRB corresponding to the quality of service flow of the source base station is from the first DRB.
  • the DRB changes to a second DRB.
  • the source base station needs to notify the target base station of the mapping relationship between qos flow and DRB. It can be the mapping relationship after the mapping relationship is changed, or it can be the mapping relationship before the change, or it can simultaneously notify the mapping relationship before and after the change. .
  • the mapping relationship can distinguish between uplink and downlink.
  • the specific form of the first indication information may be a request to establish a PDU session tunnel or a DRB tunnel.
  • the first indication information may also distinguish between uplink and downlink. For example, it may be a request to establish an uplink PDU session tunnel or an uplink DRB tunnel, or a request to establish a downlink PDU session tunnel or a downlink DRB tunnel.
  • the first indication information may indicate that the upstream or downstream data of the QoS flow that is buffered in the SDAP layer of the source base station needs to be processed, for example, it indicates that the SDAP layer has uplink data that requires special processing or downlink data that requires special processing, or both uplink and downlink have data needs Special treatment. Or the first indication information may also indicate that the source base station has not completed the remapping of the QoS flow before the base station is handed over. Alternatively, the first indication information may also indicate that uplink or downlink data is buffered in the SDAP layer of the source base station.
  • the first indication information may further distinguish between uplink and downlink indication information, that is, indicating that the quality of service flow of the source base station qos flow uplink wireless data bearer DRB changes from the first DRB to the second DRB, and / or the source base station The wireless data bearer DRB corresponding to the downlink of the quality of service flow qos flow is changed from the first DRB to the second DRB.
  • the change of the DRB corresponding to qos flow from the first DRB to the second DRB specifically means:
  • the UE sends the qos flow to the first DRB and sends it to the source base station, and changes to the qos flow to the DRB2 and sends it to the source base station. Due to the change in the mapping relationship, after the SDAP layer of the source base station receives the data units of qos flow in the second DRB, these data units are buffered in the SDAP layer of the source base station.
  • the source base station sends the qos flow to the UE through mapping to DRB1, and changes it to send to the UE through mapping to DRB2. As the mapping relationship changes, the source base station buffers the data unit sent through the second DRB in the SDAP layer of the source base station.
  • the target base station sends tunnel information to the source base station.
  • the target base station confirms that the mapping relationship between qos flow and DRB has changed, it will establish a tunnel and assign an address to the tunnel.
  • the tunnel information is then sent to the source base station.
  • the tunnel information includes the transport layer address of the tunnel and the tunnel endpoint identifier (GPRS tunneling endpoint ID, GTP-TEID) of the GPRS tunneling protocol.
  • the tunnel information sent by the target base station may distinguish between uplink and downlink, that is, uplink tunnel information and / or downlink tunnel information.
  • the tunnel is established for transferring SDAP layer buffer data.
  • the target base station sends the tunnel information to the source base station, which is used by the source base station to transfer the data unit after the corresponding DRB in the qos flow is changed to the second DRB.
  • This data unit belongs to qos flow and is also buffered in the SDAP layer of the source base station.
  • the tunnel may be a PDU session tunnel or a DRB tunnel. If the tunnel is a PDU session tunnel, the tunnel information includes the identifier of the PDU session of the protocol data unit corresponding to qos flow.
  • the source base station can determine which PDU session's tunnel information is based on the tunnel information. If the tunnel is a DRB tunnel, the tunnel information includes the DRB identifier corresponding to qos flow.
  • the source base station can determine which DRB's tunnel information is based on the tunnel information. If the tunnel is a DRB tunnel, the source base station may also send sequence number status transfer information to the target base station.
  • the tunnel may also be other types of tunnels, which are not limited here.
  • For uplink data there is no PDU session tunnel itself. By establishing a PDU session tunnel, the base station can be switched synchronously when the mapping relationship changes. The problem of out-of-order data units can occur.
  • For downlink data there is a PDU session tunnel itself. In this application, the target base station can re-establish a PDU session tunnel and transfer qos flow.
  • For uplink and downlink data there is a DRB tunnel itself, and the target base station in this application can use the original DRB tunnel to transfer qos flow.
  • the source base station carries the first indication information in the handover request, and the target base station can determine, according to the first indication information, that the DRB corresponding to the qos flow that the data unit belongs to changes from the first DRB to the second DRB.
  • the target base station sends the tunnel information to the source base station, and the source base station transfers the data units through the tunnel to ensure that the data units in the qos flow are reported in order, thereby ensuring normal communication.
  • the tunnel in this embodiment may be a PDU session tunnel or a DRB tunnel, which are respectively described below.
  • the first data unit described below in FIG. 3 to FIG. 6 is the corresponding radio data bearer when the DRB is the first DRB, and the second data unit is the corresponding DRB in the qos flow.
  • the data unit after the change to the second DRB, the first data unit and the second data unit belong to the same qos flow, and because the mapping relationship is changed, the second data unit is buffered in the SDAP layer of the source base station.
  • the first data unit is The data unit before the second data unit.
  • the tunnel is a PDU session tunnel.
  • the source base station For uplink data, the source base station carries the first indication information in the handover request, so that the target base station establishes a PDU session for transferring the qos flow buffered in the SDAP layer of the source base station due to the mapping relationship change A tunnel, so that a base station handover can also occur when the mapping relationship changes, and the data units are reported in order.
  • the UE sends a qos flow to the source base station.
  • the UE maps the qos flow to the first DRB, so that the first data unit is sent to the source base station through the first DRB. If the source base station notifies the UE to change the uplink mapping relationship of qos flow, that is, the mapping relationship between qos flow and DRB has changed, the UE generates an end indication, and the UE sends the end indication in the first DRB.
  • the end indication may be an end of the protocol data unit (PDU), which is used to indicate that the SDAP entity of the UE has stopped mapping qos flow to the first DRB, or indicates that the qos flow of the UE has been sent in the first DRB.
  • PDU protocol data unit
  • the source base station knows that the data of the qos flow has been transmitted in the first DRB.
  • the UE maps the qos flow to the second DRB, thereby sending the second data unit to the source base station through the second DRB, and the source base station buffers the second data unit in the SDAP layer.
  • the source base station may receive the second data unit before receiving the first data unit.
  • the source base station sends a handover request to the target base station.
  • the target base station sends the PDU session tunnel information to the source base station.
  • the target base station knows that the mapping relationship between qos flow and DRB has changed.
  • the target base station establishes a PDU session tunnel and assigns an address to the tunnel, and then sends the PDU session tunnel information to the source base station for the source base station to transfer the second data unit.
  • the information of the PDU session tunnel includes the transport layer address of the PDU session tunnel and the GTP-TEID.
  • the tunnel information also includes the identifier of the protocol data unit PDU session session corresponding to the QoS flow, so that the source base station determines the tunnel information of which PDU session is based on the tunnel information.
  • the PDU session tunnel is a tunnel for transmitting uplink data.
  • the target base station After the target base station passes the new PDU session tunnel, it sends the PDU session tunnel information to the source base station.
  • the source base station sends the second data unit to the target base station through a PDU session tunnel.
  • the source base station sends the second data unit to the target base station through the PDU session tunnel.
  • the second data unit is a data unit of uplink data.
  • the source base station carries an indication in a GPRS user plane tunneling protocol (GPRS, user plane, GTP-U) header or an extended header of the second data unit, indicating that the second data unit is a data unit buffered by the SDAP layer.
  • GPRS GPRS user plane tunneling protocol
  • GTP-U GPRS user plane tunneling protocol
  • the source base station may further carry a qos flow label in the GTP-U header or the extended header of the second data unit to indicate which data unit is the qos flow data unit in the PDU session tunnel.
  • the source base station does not receive all the data packets of the first data unit, some data packets in the first data unit sent by the UE to the source base station are not correctly received by the source base station due to changes in the wireless communication channel. However, the data packets following these data packets in the first data unit are correctly received by the source base station, and the source base station cannot submit these correctly received data packets to the core network device. For example, packet_1 is not received correctly, while packet_2 / 3 is received correctly by the base station, and packet_2 / 3 cannot be submitted to the core network device by the source base station.
  • the source base station needs to transfer packet_2 / 3 to the target base station through the tunnel corresponding to the DRB where these data packets are located, and the UE will resend packet_1 to the target base station in DRB1.
  • the target base station will only submit packet_1 / 2/3 to the core network device after receiving packet_1.
  • the data packet received by the source base station (such as packet_2 / 3) is transferred to the target base station, because the UE sends an end indication to the source base station through DRB1.
  • the base station receives the end instruction correctly.
  • the source base station will also forward the end instruction to the target base station through the DRB tunnel corresponding to DRB1.
  • the data packet and end instruction form that the source base station forwards to the target base station is PDCP SDU.
  • the target base station receives these After PDCP and SDU (usually buffered at the PDCP layer), it is necessary to wait for the data packets before the data packets (such as packet_1 above) to be correctly received before submitting them to the SDAP layer of the target base station.
  • the source base station receives all the data packets of the first data unit, the source base station submits the first data unit to the core network device, and at the same time, the source base station instructs the target base station to complete the transfer.
  • the source base station sends a handover command to the UE to notify the UE to perform an inter-base station handover.
  • the UE After receiving the corresponding handover command, the UE performs access in the cell of the target base station.
  • the target base station obtains an end instruction.
  • the target base station obtains the end indication means that the SDAP layer of the target base station receives the end indication.
  • the source base station After the source base station correctly receives the end instruction sent by the UE, the source base station will transfer the end instruction to the target base station. It should be noted that the source base station transfers the end instruction to the target base station in the form of PDCP SDU.
  • the UE Due to the influence of the change of the wireless communication channel, if the source base station does not correctly receive the end indication sent by the UE, the UE will again send the end indication to the target base station through DRB1. It should be noted that what the UE retransmits is the PDCP SDU corresponding to the end indication;
  • the target base station sends the second data unit to the core network device according to the end instruction.
  • the target base station learns that all the data units transmitted through the first DRB have been received according to the instruction. It can further be learned that the source base station or the target base station has submitted the first data unit to the core network device. Subsequently, the target base station sends the second data unit to the core network device, so as to ensure that the second data unit is sent to the core network device after the first data unit, thereby ensuring sequential reporting between the data units.
  • the source base station carries the first indication information in the handover request, and the target base station can determine the DRB corresponding to qos flow from the first DRB to the second DRB according to the first indication information, so that the target base station sends a PDU session.
  • the information of the tunnel is transmitted to the source base station, and the second data unit is transferred through the tunnel.
  • the target base station submits the second data unit to the core network device, thereby ensuring that the data units in the qos flow are submitted in order. This ensures the normal communication of the communication system.
  • the source base station carries the first indication information in the handover request, so that the target base station establishes a PDU session for transferring the qos flow buffered in the SDAP layer of the source base station due to the mapping relationship transition.
  • a tunnel so that a base station handover can also occur when the mapping relationship changes, and the data units are reported in order.
  • the source base station sends a first data unit to the UE.
  • the source base station maps the qos flow to the first DRB, so as to send the first data unit to the UE.
  • the source base station changes the downlink mapping relationship of qos flow, that is, the mapping relationship between qos flow and DRB changes, and the DRB mapped by qos flow changes from the first DRB to the second DRB.
  • the source base station buffers the second data unit of the qos and flow that needs to be sent through the second DRB in the SDAP layer of the source base station.
  • the source base station sends a handover request to the target base station.
  • the target base station sends the PDU session tunnel information to the source base station.
  • the target base station knows that the mapping relationship between qos, flow, and DRB has changed.
  • the target base station establishes a PDU session tunnel, assigns an address to the tunnel, and then sends the PDU session tunnel information to the source base station for the source base station to transfer the second data. unit.
  • the information of the PDU session tunnel includes the transport layer address of the PDU session tunnel and the GTP-TEID.
  • the tunnel information also includes the identifier of the protocol data unit PDU session session corresponding to the QoS flow, so that the source base station determines the tunnel information of which PDU session is based on the tunnel information.
  • the PDU session tunnel is a tunnel for transmitting downlink data.
  • the target base station can send the information of the PDU session tunnel to the source base station by creating a new PDU session tunnel.
  • the existing PDU session tunnel can also be used to send the information of the PDU session tunnel to the source base station.
  • the source base station transfers the second data unit through the existing PDU session tunnel, it needs to add instruction information for indicating the second data unit.
  • the source base station sends the second data unit to the target base station through the PDU session tunnel.
  • the source base station sends the second data unit to the target base station through the PDU session tunnel.
  • the second data unit is a data unit of downlink data.
  • the source base station carries an instruction in the GPRS user plane tunneling protocol header or extended header of the second data unit, indicating that the second data unit is a data unit buffered by the SDAP layer.
  • the source base station may further carry a qos flow label in the GTP-U header or the extended header of the second data unit to indicate which data unit is the qos flow data unit in the PDU session tunnel.
  • some data packets in the first data unit sent by the source base station to the UE are not correctly received by the UE, and the source base station needs to transfer these data packets to the target base station through the DRB tunnel.
  • packet_2 / 3 is not correctly received by the UE, and the source base station needs to transfer packet_2 / 3 to the target base station through the DRB tunnel.
  • the target base station will resend packet_2 / 3 to the UE in DRB1.
  • the target base station After the target base station determines that the qos flow mapped to the first DRB is received by the UE, the target base station sends the second data unit to the UE.
  • the target base station determines, according to the first instruction information, that the DRB corresponding to the qos flow before the mapping relationship changes is the first DRB, and determines whether the qos flow (that is, the first data unit) mapped to the first DRB is received by the UE.
  • the judgment method may be: The target base station determines whether qos flow exists on the first DRB. If it does not exist, it proves that the first data unit has been received by the UE, or the target base station sets a timer. After the timer expires, the first data unit is considered to have been received by the UE.
  • the target base station may determine whether the qos flow mapped to the first DRB is received by the UE in other manners, which is not limited herein.
  • the target base station maps the qos flow to the second DRB to send the second data unit to the UE, thereby ensuring that the second data unit is sent after the first data unit. To the UE, sequential reporting between data units is guaranteed.
  • the source base station carries the first indication information in the handover request, and the target base station can determine, according to the first indication information, that the DRB corresponding to the qos flow that the data unit belongs to changes from the first DRB to the second DRB.
  • the target base station sends the PDU session tunnel information to the source base station, and the source base station and the target base station use the PDU session tunnel to transfer the second data unit, so that after the target base station determines the mapping relationship between qos flow and the first DRB, the first A data unit has been reported to the UE, and the target base station sends a second data unit to the UE to ensure that the data units in the qos flow are reported in order, thereby ensuring normal communication of the communication system.
  • the tunnel is a DRB tunnel.
  • the source base station For uplink data, the source base station carries the first indication information in the handover request, so that the target base station establishes a DRB tunnel for transferring the qos flow buffered in the SDAP layer of the source base station due to the mapping relationship transition. And sends the information of the DRB tunnel to the source base station, and then the source base station sends the sequence number state transition information to the target base station through the control plane, and sends the second data unit to the target base station through the DRB tunnel.
  • the target base station can know which data packets are the data packets of the second data unit according to the sequence number state transfer information or the source base station transfers the indication information carried by the second data unit, so that the base station handover can also occur when the mapping relationship changes, and the data is guaranteed
  • the units are reported in order.
  • the UE sends a qos flow to the source base station.
  • the source base station sends a handover request to the target base station.
  • Steps 501 to 502 in this embodiment are similar to steps 301 to 302 in the foregoing embodiment, and details are not described herein again.
  • the target base station sends the DRB tunnel information to the source base station.
  • the target base station knows that the mapping relationship between qos flow and DRB has changed.
  • the target base station establishes a DRB tunnel and assigns an address to the tunnel.
  • the DRB tunnel can be the original DRB tunnel, and then sends the DRB tunnel information to the source.
  • the DRB tunnel information includes the transport layer address of the DRB tunnel and the GTP-TEID.
  • the tunnel information includes a DRB identifier corresponding to qos flow, so that the source base station determines which DRB tunnel information is based on the tunnel information.
  • the DRB tunnel is a DRB tunnel for transmitting uplink data.
  • the source base station After the source base station obtains the address information of the DRB tunnel, it sends the second data unit buffered in the SDAP layer of the source base station to the target base station in the form of a packet data convergence protocol service data unit (PDCP, SDU).
  • PDCP packet data convergence protocol service data unit
  • SDU packet data convergence protocol service data unit
  • the data of the source base station is transferred to the target base station through the DRB tunnel, which can ensure the lossless handover of the transferred data.
  • the source base station sends the serial number status transition information of the second data unit to the target base station at the same time.
  • the serial number status transition information is specifically packet data convergence protocol serial number (PDCP serial number) information, and the target base station According to the sequence number state transition information, it can be known which data packets transmitted in the tunnel are data packets belonging to the second data unit.
  • the source base station may restore the second data unit buffered in the SDAP of the source base station to the PDCP SDU, and at the same time restore the PDCP SN number of the second data unit at the PDCP layer.
  • the source base station and the target base station have a DRB tunnel corresponding to the first DRB and a DRB tunnel corresponding to the second DRB.
  • the DRB tunnel in this application may be the same tunnel as the DRB tunnel corresponding to the second DRB.
  • the present application also uses the sequence number state transition information of the second data unit to indicate that the second data unit sent by the source base station to the target base station is a data unit buffered in the SDAP layer of the source base station, for example, the DRB is indicated by a bit string of the PDCP SN number.
  • the data unit before the SN corresponding to the first lost uplink PDCP and SDU in the DRB corresponding to the tunnel is a buffered SDAP layer data unit.
  • the PDCP corresponding to the first lost data unit has an SN number of X, and a bit string is used.
  • the source base station sends a handover command to the UE to notify the UE to perform inter-base station handover.
  • the UE After receiving the corresponding handover command, the UE performs access in the cell of the target base station.
  • the source base station may carry some indication information when transferring the second data unit through the DRB tunnel, indicating that the data unit is the second data unit buffered in the SDAP layer, so as to communicate with other sources transferred between the source base station and the target base station. Classes of data units are distinguished from data units that are not cached in the SDAP layer.
  • the source base station carries sequence number status indication information in a GTP-U header or an extended header of the second data unit.
  • the source base station may also carry a qos flow label in the GTP-U header or the extended header of the second data unit to indicate which qos flow data unit in the PDU session tunnel the packet is.
  • the target base station determines that the second data unit is a data unit buffered in an SDAP layer of the source base station.
  • the target base station may confirm that the second data unit is a data unit buffered in the SDAP layer of the source base station according to the serial number state transition information of the second data unit.
  • the target base station may also confirm that the second data unit is a data unit buffered in the SDAP layer of the source base station according to the indication information carried in the DRB tunnel transfer data.
  • the target base station obtains end indication information.
  • the source base station does not receive all the data packets of the first data unit and the source base station receives all the data packets of the first data unit, the possibility that the first data unit submits the core network equipment and the possibility that the target base station obtains the end instruction
  • the situation is similar to the corresponding description in step 304 of the foregoing embodiment, and details are not described herein again.
  • Step 506 in this embodiment is similar to step 305 in the foregoing embodiment, and details are not described herein again.
  • the target base station sends the second data unit to the core network device according to the end instruction.
  • Step 507 in this embodiment is similar to step 306 in the foregoing embodiment, and details are not described herein again.
  • the source base station sends the second data unit to the target base station through the DRB tunnel, and at the same time sends the serial number status indication information of the second data unit to the target base station or carries the indication information when sending the second data unit, so that
  • the target base station determines that the second data unit is a data unit buffered in the SDAP layer due to a change in the mapping relationship according to the instruction information, so that after receiving the end instruction sent by the UE, the second data unit can be changed to the second data unit even if the first data unit is not received.
  • the data unit is reported to the core network equipment to ensure that the first data unit and the second data unit are reported in order.
  • the source base station carries the first indication information in the handover request, so that the target base station establishes a DRB tunnel for transferring the qos flow buffered in the SDAP layer of the source base station due to the mapping relationship transition. And send the DRB tunnel information to the source base station, and then the source base station sends the sequence number status transfer information to the target base station through the control plane, and sends the second data unit to the target base station through the DRB tunnel, and the target base station transfers the information or source according to the sequence number status.
  • the base station transfers the indication information carried by the second data unit to the second data unit separately to the UE, so that when the mapping relationship changes, a base station handover can also occur, and the data units are reported in order.
  • the source base station sends a first data unit to the UE.
  • the source base station sends a handover request to the target base station.
  • Steps 601 to 602 in this embodiment are similar to steps 401 to 402 in the foregoing embodiment, and details are not described herein again.
  • the target base station sends the DRB tunnel information to the source base station.
  • step 503 the DRB tunnel is a DRB tunnel for transmitting downlink data, and details are not described herein again.
  • the source base station sends the second data unit to the target base station through the DRB tunnel.
  • step 504 the second data unit is a data unit for downlink data, and details are not described herein again.
  • the data of the source base station is transferred to the target base station through the DRB tunnel, which can ensure the lossless handover of the transferred data.
  • the target base station determines that the second data unit is a data unit buffered in an SDAP layer of the source base station.
  • the target base station After the target base station determines that the qos flow mapped to the first DRB is received by the UE, the target base station sends the second data unit to the UE.
  • Step 606 in this embodiment is similar to step 405 in the foregoing embodiment, and details are not described herein again.
  • the source base station sends the second data unit to the target base station through the DRB tunnel, and at the same time sends the serial number status indication information of the second data unit to the target base station or carries the indication information when sending the second data unit, so that
  • the target base station determines that the second data unit is a data unit buffered in the SDAP layer due to a change in the mapping relationship according to the sequence number status indication information, so that after receiving the end instruction sent by the UE, even if the first data unit is not received,
  • the second data unit UE ensures that the first data unit and the second data unit are reported in sequence.
  • the source base station sends a handover request to the target base station.
  • the handover request includes first indication information, and the first indication information is used to indicate that a wireless data bearer DRB corresponding to the quality of service flow qos of the source base station is changed from the first DRB to the second DRB.
  • the specific form of the first indication information and the change of the DRB corresponding to the QoS flow from the first DRB to the second DRB are similar to those in step 201 of the foregoing embodiment, and details are not described herein again.
  • the source base station receives tunnel information sent by the target base station.
  • the target base station after the target base station establishes a tunnel, it allocates an address for the tunnel and sends information about the tunnel to the target base station.
  • the tunnel information includes the transport layer address and the tunnel endpoint identifier GTP-TEID of the GPRS tunnel protocol.
  • the tunnel information sent by the target base station may distinguish between uplink and downlink, that is, information about the uplink tunnel and / or information about the downlink tunnel.
  • the tunnel can be a PDU session tunnel or a DRB tunnel. If the tunnel is a PDU session tunnel, the tunnel information includes the identifier of the protocol data unit PDU session session corresponding to qos flow, so that the source base station can determine which PDU session Tunnel information. If the tunnel is a DRB tunnel, the tunnel information includes the DRB identifier corresponding to qos flow, so that the source base station can determine which DRB tunnel information is based on the tunnel information. If the tunnel is a DRB tunnel, if the tunnel is a DRB tunnel The source base station also needs to receive serial number status transition information from the target base station. The serial number status transition information includes the PDCP SN number of the data unit, and the role of the PDCP SN number is similar to the above embodiment, and details are not described herein again.
  • the source base station sends a data unit to the target base station through a tunnel.
  • the data unit is the data unit after the change of the DRB corresponding to the qos flow to the second DRB, and the data unit before the change of the DRB corresponding to the qos flow also exists in the qos flow.
  • the source base station sends the data unit to the target base station through the tunnel, so that for the uplink data, after receiving the end instruction sent by the UE, the target base station can determine that the mapping relationship between qos and flow and the first DRB has ended, so the target base station sends the data unit to Core network equipment to ensure the orderly reporting of data units in qos flow.
  • the target base station judges whether the mapping relationship between qos flow and the first DRB is ended. If so, the target base station sends data units to the UE to ensure that the data units in qos flow are reported in order.
  • the source base station sends a handover request carrying the first indication information to the target base station so that the target base station feedbacks information about the tunnel.
  • the tunnel is used by the source base station to transfer the wireless data bearer DRB corresponding to the qos flow from the first DRB. It is the data unit after the second DRB, thereby ensuring the sequential reporting of data units in qos flow.
  • the present application further provides a handover method, in which a source base station changes a corresponding DRB in qos flow to a second data unit after reporting the second DRB to a core network device, and the target base station responds to the The DRB that is the first DRB of the first DRB is reported to the core network device, and the core network device sorts the first data unit and the second data unit.
  • the source base station sends a handover request to the target base station.
  • the source base station sends a handover request to the target base station, requesting a handover.
  • the target base station sends tunnel information to the source base station.
  • the target base station establishes a tunnel after receiving the handover request, and then sends the tunnel information to the source base station.
  • the tunnel can be a DRB tunnel or a PDU session tunnel, which is not limited here.
  • the source base station sends the second data unit and out-of-order indication information to the core network device.
  • the source base station Since the mapping relationship between the upstream qos flow and the DRB received by the source base station changes from the first DRB to the second DRB, the source base station first receives the change in the corresponding DRB in the qos flow to the second DRB. Two data units, and then the source base station receives the first DRB sent by the UE through the first DRB before the corresponding DRB mapping relationship in the qos flow changes, and the first data unit and the second data unit belong to the same qos flow, and the qos flow Because the mapping relationship transition is buffered in the SDAP layer of the source base station, the first data unit is the data unit before the second data unit in timing.
  • the source base station When a base station handover occurs, the source base station sends a second data unit and out-of-order indication information to the core network device.
  • the out-of-order indication information is used to indicate that the second data unit reported by the source base station is a data unit sent in an abnormal order. Before the data unit, there are data units that have not been reported.
  • the out-of-order indication information may be carried in the GTP-U header or the extension header of the second data unit.
  • the source base station sends the first data unit to the target base station through a tunnel.
  • the target base station obtains a first end instruction.
  • the UE maps the qos flow to the first DRB, thereby sending the first data unit to the source base station through the first DRB. Subsequently, the source base station notifies the UE to change the uplink mapping relationship of the qos flow, that is, the mapping relationship between the qos flow and the DRB has changed. After receiving the notification that the mapping relationship is changed, the UE generates a first end indication, and the UE sends the first end indication in the first DRB.
  • the source base station will transfer the first end instruction to the target base station. It should be noted that the source base station transfers the first end instruction to the target base station in the form of PDCP SDU.
  • the UE Due to the influence of the change of the wireless communication channel, if the source base station does not correctly receive the first end indication sent by the UE, the UE will again send the first end indication to the target base station through the first DRB. It should be noted that what the UE retransmits is the PDCP SDU corresponding to the first end instruction.
  • the target base station sends the first data unit and the second end indication to the core network device.
  • the target base station When the SDAP layer of the target base station receives data corresponding to the first data unit, the target base station sends the data to the core network.
  • the SDAP layer of the target base station receives the first end instruction sent by the UE, it can know that the mapping relationship between qos flow and the first DRB has ended according to the first end instruction, and the target base station sends a second end instruction to the core network. According to the second end instruction, the network device knows that all the data units before the mapping relationship change in qos flow have been received by the core network device.
  • the core network device sorts the first data unit and the second data unit according to the out-of-order instruction information and the second end instruction.
  • the core network device determines that the data unit before the second data unit has been received according to the second end instruction, and determines that the first data unit is the data unit before the second data unit according to the out-of-order instruction information, so that the first data unit and the The second data unit is sorted to ensure the sequence between the first data unit and the second data unit, thereby ensuring normal communication of the communication system.
  • the handover method is similar to the method described in FIG. 8 (a) above.
  • the target base station cannot receive the first end instruction sent by the UE, but the target base station Determine for yourself whether the qos flow mapped to the first DRB is the first data unit received by the UE.
  • the judgment method may be: the target base station determines whether the qos flow exists on the first DRB. If it does not exist, it proves that the first data unit has been Received by the UE, or the target base station sets a timer. After the timer expires, the first data unit is considered to have been received by the UE.
  • the target base station determines whether the qos flow mapped to the first DRB is received by the UE. There are other ways. There are no restrictions. At the same time, the first data unit and the second data unit are reported to the UE instead of the core network device.
  • FIG. 2 to FIG. 8 (b) above are also applicable to the scenario of indirect interaction through the core network during the handover process.
  • the message interaction with the target base station first passes through the core network equipment, and then to the opposite end.
  • the source base station may transfer a part of the qos flow to the target base station for transmission.
  • the base station sends an encryption indication (security indication) to the core network device.
  • the encryption indication is one of a preferred indication, a required indication, and a not required indication.
  • the base station determines to perform a corresponding operation on the qos flow of the PDU session according to the encryption instruction.
  • the base station may also send integrity protection indication (integrity protection indication) to the core network device.
  • the integrity protection indication is one of a preferred integrity protection indication (preferred) indication, a required integrity protection indication (required) indication, and a not required integrity protection indication (not needed) indication.
  • the base station determines to perform a corresponding operation on the qos flow of the PDU session according to the integrity protection instruction.
  • the tendency indication represents that the base station decides whether to perform encryption or integrity protection. It needs to instruct the delegate base station to perform encryption or integrity protection. It does not need to instruct the delegate base station not to perform encryption or integrity protection.
  • the core network device sends a selection instruction to the source base station.
  • the core network device sends a selection indication to the source base station, where the selection indication is the above-mentioned tendency to encryption indication.
  • the source base station encrypts or does not encrypt qos flow according to the selection instruction.
  • the source base station chooses to encrypt or not to encrypt the PDU session according to the selection instruction.
  • the source base station sends a handover request message to the target base station.
  • the handover request message requests to switch some QoS in the pdu session to the target base station, and the request message also carries the operation instruction of the source base station.
  • the source base station when the source base station switches to the target base station, the source base station will transfer some qos flows in the PDU session to the target base station, and at the same time, send the operation instructions of the source base station to the target base station, so that the target base station can Indicates whether the source base station has performed encryption.
  • the source base station operation instruction may include a selection instruction and a cell.
  • the source base station operation instruction may also be: the source base station modifies the encryption instruction sent by the core network device according to its own operation, and the required encryption instruction or no encryption instruction is obtained, for example, the encryption instruction given to the source base station by the source base station is based on whether the source base station is currently The pdu session is encrypted and replaced with a required instruction or a required instruction.
  • the target base station encrypts or does not encrypt the received QoS flow according to the operation instruction of the source base station.
  • the way the target base station encrypts or does not encrypt some received QoS flows according to the operation instructions of the source base station is as follows:
  • the source base station forwards the selection instruction sent by the core network device to the source base station, and carries a cell, which is used to indicate that the source base station has encrypted or not encrypted the qos flow, so that the target base station also Some qos flow received are encrypted; another way is: the source base station changes the selection instruction to an encryption instruction or no encryption instruction, and if the source base station encrypts the qos flow, it sends an encryption instruction to the target base station, so that the target base station Some received qos flows are also encrypted. If the source base station does not encrypt the qos flows, an unencrypted indication is sent to the target base station, so the target base station does not encrypt some qos flows received.
  • the source base station if it encrypts the qos flow, it will send an operation instruction of the source base station to the target base station, so that the target base station can perform the corresponding encryption operation according to the operation instruction, ensuring that the encryption operation is performed at the source base station and the target. Base station consistency.
  • FIG. 10 Please refer to FIG. 10.
  • the situation of integrity protection is similar to that of encryption.
  • an operation instruction of the source base station is sent to the target base station so that the target base station can perform a corresponding integrity protection operation according to the operation instruction. The details are not repeated here.
  • the base station can serve the UE in a dual link (DC) manner.
  • DC the UE communicates with two base stations at the same time, where the two base stations are called a master base station (master node, MN) and a secondary base station (secondary node, SN), respectively.
  • MN master node
  • SN secondary node
  • the MN will configure at least two DC methods for the UE.
  • both the MN and SN are connected to the 5G core network 5GC or in a subsequently evolved mobile network
  • DC methods E.g:
  • LTE DC and E-UTRA NR DC are two DC modes in the scenario of 4G core network EPC:
  • LTE DC the DC mode at this time is called LTE DC
  • MN is an LTE base station eNB and SN is an NR base station gNB.
  • the DC mode is called E-UTRA, NR, DC, and EN-DC for short.
  • NG EN-DC, NE-DC, and NR-NR DC are three DC modes in the scenario where both MN and SN are connected to 5G core network 5GC:
  • MN is the base station ng-eNB of LTE
  • SN is the NR base station gNB
  • the DC mode at this time is called NGEN-DC
  • MN is the NR base station gNB and SN is the LTE base station ng-eNB.
  • the DC mode at this time is called NE-DC;
  • MN and SN are both NR base stations gNB, and the DC mode at this time is called NR-NR DC.
  • the key used by the UE and the MN for communication is different from the key used by the UE and the SN for communication.
  • the key used for communication between the UE and the MN is referred to as a master key (M-key)
  • the key used for the communication between the UE and the SN is referred to as a secondary key (S-key).
  • M-key master key
  • S-key secondary key
  • the security parameter is the count value of the SN counter. .
  • the specific name of the SN counter may be different.
  • the cells of the SN counter in the protocol may be different, but the functions implemented are the same.
  • the MN may configure two or more DC methods for the UE in succession.
  • the SN counter of each DC method is maintained and configured separately.
  • each SN counter may be incremented from 0 or 1 one by one, this results in that in different DC modes, there may be UEs using the same SN counter value, so in the case of the same M-key, this is the case.
  • the UE derives the same S-key, and then different SNs use the same S-key to communicate with the UE, which affects the communication security of the air interface.
  • This application also provides a communication method, so as to ensure communication security.
  • the method may include the following two ways.
  • Method 1 In different DC modes, the M-key of the UE is fixed. When different DCs are configured for the UE in the MN, different SN counter values are configured for the UE to derive different S-keys.
  • Method 2 Under different DC methods, the MN staggers the configurable value range of the SN counter, thereby ensuring that different DC methods use different count values of the SN counter.
  • the following method may be used:
  • the UE receives the first count value sent by the main base station MN, and the first count value is the count value of the SN counter when the MN configures the first DC mode for the UE.
  • the MN configures the first DC mode for the UE
  • the first count value of the SN counter is sent to the UE, and the first count value is an integer greater than or equal to zero.
  • the first DC method is any one of long-term evolution (LTE) DC, E-UTRA, NR, DC, NG, EN-DC, NE-DC, and NR-NR. Be limited.
  • LTE long-term evolution
  • the UE When the UE releases the first DC mode, the UE retains the first count value.
  • the UE releasing the first DC mode indicates the configuration of the UE releasing the secondary base station in the first DC mode. This may be actively released by the UE itself, or the MN may instruct the UE to release the first DC mode configuration.
  • the configuration of the secondary base station includes a first count value, but the UE does not delete the first count value corresponding to the stored first DC mode when the UE releases the first DC mode.
  • the UE receives a second count value sent by the main base station MN, and the second count value is a count value of the SN counter when the MN configures the second DC mode for the UE.
  • the second count value of the SN counter is sent to the UE, and the second count value is an integer greater than or equal to zero.
  • the second DC method is a DC method different from the first DC method, and the second DC method is one of LTEDC, E-UTRA, NRDC, NGEN-DC, NE-DC, and NR-NRDC. Either way is not specifically limited.
  • the UE determines whether the second count value is abnormal according to the first count value.
  • the UE may determine, according to the first count value, whether the second count value is abnormal.
  • the two practicable methods include:
  • the UE determines whether any count value in the count value set before the second count value is received is the same as the second count value, where the first count value belongs to the count value set. In this case, the UE needs to store the counter value of each SN counter configured by the MN.
  • the first count value is the latest count value set by the MN in the set of count values immediately before the second count value, since the count value of the SN counter is incremented one by one, the count values previously configured by the MN are less than Or equal to the first count value, only the second count value is greater than the first count value at this time, it can be determined that the second count value has not been used by the MN, the second count value is normal, and if the second count value is less than the first count value , The second count value is abnormal.
  • the UE only needs to store the latest SN counter value configured by the MN.
  • the MN first configures LTE DC for the UE, and instructs the SN counter count value to be x1, and the UE derives the first S-key for communication with the first SN based on the M-key and the count value x1. Subsequently, the UE released the LTE DC method, and at the same time, the UE deleted the configuration of the LTE DC. The configuration of the LTE DC included a count value x1, but the UE did not delete the count value x1. Subsequently, the MN configures the EN-DC for the UE, and instructs the SN counter to be a value x2, and the UE determines whether x2 is abnormal according to x1.
  • the UE sends configuration failure identification information to the MN.
  • the configuration failure identification information can be sent in the following two ways:
  • the UE triggers a re-establishment procedure to establish a connection with the MN.
  • the UE reports the configuration failure identification information to the MN.
  • the reason for the configuration failure may be the SN counter configuration failure or the DC configuration failure. Therefore, the configuration failure identification information may indicate that the configuration has failed. It can also indicate the specific reason for the configuration failure.
  • the MN determines the specific reason for the failure according to the configuration failure identification information, and reconfigures the counter value of the SN counter for the UE.
  • the UE considers that an SCG configuration failure has occurred and sends a failure report to the MN.
  • the failure report carries configuration failure identification information.
  • the reason for the configuration failure can be SN counter configuration failure or DC configuration failure. Therefore, the configuration failure identification information indicates the configuration failure and also the specific reason for the configuration failure.
  • the failure report does not include a measurement result
  • the measurement result is a signal quality measurement result of at least one of the serving cell and the neighbor cell of the UE.
  • the subsequent MN After the subsequent MN receives the failure report, it identifies the configuration failure identification information in the failure report, determines the specific cause of the failure based on the configuration failure identification information, and reconfigures the counter value of the SN counter for the UE.
  • the MN may also send the reconfigured SN counter value to the SN. Further optionally, the configuration failure identification information is sent to the SN.
  • the UE determines whether the second count value is abnormal by using the first count value. If the same count value is configured in the MN, the UE sends configuration failure identification information to the MN to avoid MN derivative in different DC modes. The same S-key is obtained, which ensures the communication security of the air interface.
  • the MN allocates different SN counter value value space for different DC modes through a configuration protocol, and each count value value space does not overlap with each other.
  • the MN defines the starting point of the count value space of multiple SN counters through the configuration protocol.
  • the MN configures a certain DC mode for the UE, it identifies whether the UE has previously configured other DC modes, and if so, configures the values in a staggered manner, such as selecting a new starting point for the value space.
  • two or more of the three methods A, B, and C may be used in combination.
  • FIG. 12 Please refer to FIG. 12 to describe a possible structure of the base station of the present application.
  • a base station 120 includes:
  • a receiving unit 1201 is configured to receive a handover request sent by a source base station, where the handover request includes first indication information, where the first indication information is used to indicate a radio data bearer DRB corresponding to a quality of service flow qos flow of the source base station.
  • the first DRB changes to the second DRB;
  • a sending unit 1202 is configured to send information about a tunnel to the source base station, where the tunnel is used by a target base station to receive a data unit sent by the source base station, where the data unit is the DRB corresponding to the qos flow Change to the data unit after the second DRB.
  • the first indication information is used to instruct the radio data bearer DRB corresponding to the QoS flow received by the source base station to change from the first DRB to the second DRB, including:
  • the first indication information is used to indicate that the qos flow received from the user equipment UE received by the source base station changes from mapping to the first DRB to mapping to the second DRB, and the qos flow is Qos flow buffered in the service data adaptation protocol SDAP layer of the source base station due to the corresponding DRB change;
  • the first indication information is used to instruct the qos flow sent by the source base station to the UE to change from mapping to the first DRB to mapping to the second DRB, and the qos flow is due to The qos flow corresponding to the DRB change is buffered in the SDAP layer of the source base station.
  • the receiving unit 1201 is further configured to obtain an end instruction, where the end instruction is used to instruct an SDAP entity of the UE to stop mapping the qos flow to the first DRB;
  • the sending unit 1202 is further configured to send the data unit to the UE through the second DRB after the qos flow mapped to the first DRB is received by the UE.
  • the tunnel information includes an identifier of a protocol data unit PDU session session corresponding to the qos flow.
  • the receiving unit 1201 is further configured to receive second indication information from the source base station, where the second indication information is used by the target base station to determine that the data unit is due to a corresponding change in the DRB And a data unit buffered in the SDAP layer of the source base station.
  • the base station further includes:
  • the address allocation unit 1203 is configured to allocate an address for the tunnel.
  • the receiving unit 1201 is further configured to receive serial number status transition information from the source base station, where the serial number status transition information includes an SN number of the data unit.
  • the SN number of the data unit is used by the target base station to determine that the data unit is a data unit buffered in the SDAP layer of the source base station due to a corresponding change in the DRB.
  • FIG. 13 Please refer to FIG. 13 to describe another possible structure of the base station of the present application.
  • a base station 130 includes:
  • a sending unit 1301 is configured to send a handover request to a target base station, where the handover request includes first indication information, where the first indication information is used to instruct a radio data bearer DRB corresponding to a quality of service flow qos flow of the source base station from the first One DRB changes to a second DRB;
  • the sending unit 1301 is further configured to send the data unit to the target base station through the tunnel, where the data unit is a data unit after the DRB corresponding to the qos flow is changed to the second DRB .
  • the base station 1400 includes:
  • the receiver 1401, the transmitter 1402, the processor 1403, and the memory 1404 (wherein the number of processors 1403 in the base station 1400 may be one or more, and one processor is taken as an example in FIG. 14).
  • the receiver 1401, the transmitter 1402, the processor 1403, and the memory 1404 may be connected through a bus or other manners. In FIG. 14, a connection through a bus is taken as an example.
  • the memory 1404 may include a read-only memory and a random access memory, and provide instructions and data to the processor 1403. A part of the memory 1404 may further include a non-volatile random access memory (full English name: non-volatile random access memory, English abbreviation: NVRAM).
  • the memory 1404 stores an operating system and an operation instruction, an executable module or a data structure, or a subset thereof, or an extended set thereof.
  • the operation instruction may include various operation instructions for implementing various operations.
  • the operating system may include various system programs for implementing various basic services and processing hardware-based tasks.
  • the processor 1403 controls the operation of the network device.
  • the processor 1403 may also be referred to as a central processing unit (full English name: central processing unit, English abbreviation: CPU).
  • CPU central processing unit
  • the various components of the network equipment are coupled together by a bus system.
  • the bus system may include a power bus, a control bus, and a status signal bus in addition to the data bus.
  • various buses are called bus systems in the figure.
  • the method disclosed in the foregoing embodiment of the present application may be applied to the processor 1403, or implemented by the processor 1403.
  • the processor 1403 may be an integrated circuit chip and has a signal processing capability.
  • each step of the above method may be completed by an integrated logic circuit of hardware in the processor 1403 or an instruction in the form of software.
  • the above processor 1403 may be a general-purpose processor, a digital signal processor (full name in English: digital processing, English abbreviation: DSP), an application specific integrated circuit (full name in English: application specific integrated circuit, English abbreviation: ASIC), field programmable Gate array (full name in English: field-programmable gate array, English abbreviation: FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.
  • DSP digital signal processor
  • ASIC application specific integrated circuit
  • FPGA field programmable Gate array
  • a general-purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
  • the steps of the method disclosed in combination with the embodiments of the present application may be directly implemented by a hardware decoding processor, or may be performed by using a combination of hardware and software modules in the decoding processor.
  • the software module may be located in a mature storage medium such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, and the like.
  • the storage medium is located in the memory 1404, and the processor 1403 reads the information in the memory 1404 and completes the steps of the foregoing method in combination with its hardware.
  • the receiver 1401 may be used to receive inputted digital or character information, and generate signal inputs related to network device related settings and function control.
  • the transmitter 1402 may include display devices such as a display screen, and the transmitter 1402 may be used to output numbers through an external interface. Or character information.
  • the processor 1403 is configured to execute the foregoing method.
  • the device embodiments described above are only schematic, and the modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be A physical unit can be located in one place or distributed across multiple network units. Some or all of the modules may be selected according to actual needs to achieve the objective of the solution of this embodiment.
  • the connection relationship between the modules indicates that there is a communication connection between them, which can be specifically implemented as one or more communication buses or signal lines.
  • the technical solution of this application that is essentially or contributes to the existing technology can be embodied in the form of a software product, which is stored in a readable storage medium, such as a computer's floppy disk , U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or CD-ROM, etc., including several instructions to make a computer device (can be A personal computer, a server, or a network device, etc.) execute the methods described in the embodiments of the present application.
  • a computer device can be A personal computer, a server, or a network device, etc.
  • 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 from a website site, computer, server, or data center Transmission by wire (for example, coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (for example, infrared, wireless, microwave, etc.) to another website site, computer, server, or data center.
  • wire for example, coaxial cable, optical fiber, digital subscriber line (DSL)
  • wireless for example, infrared, wireless, microwave, etc.
  • the computer-readable storage medium may be any available medium that can be stored by a computer or a data storage device such as a server, a data center, and the like that includes one or more available medium integration.
  • the available 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 (Solid State Disk (SSD)), and the like.

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Abstract

一种切换方法，用于源基站与目标基站通过隧道传输由于qos flow中对应的DRB变化为第二DRB后的数据单元。本申请实施例方法包括：目标基站接收源基站发送的切换请求，所述切换请求包括第一指示信息，所述第一指示信息用于指示所述源基站的服务质量流qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB；所述目标基站向所述源基站发送隧道的信息，所述隧道用于供所述目标基站接收所述源基站发送的数据单元，所述数据单元为所述qos flow中对应的所述DRB变化为所述第二DRB后的数据单元。

Description

一种切换方法及基站
本申请要求于2018年9月28日提交中国专利局、申请号为201811142682.4、发明名称为“一种切换方法及基站”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
本申请涉及通信领域，尤其涉及一种切换方法及基站。
背景技术
在5G场景下，对于每个UE而言，第五代核心网设备(5 generation core，5GC)为其建立一个或多个协议数据单元会话(protocol data unit session，PDU session)。同时，5G无线接入网(NG-RAN)为每个PDU session建立一个或多个数据无线承载(data radio bearer，DRB)为是基站和终端之间的数据承载，该数据承载中的数据具备相同的转发处理。服务质量流(quality of Service flow，qos flow)在PDU session内，具备相同服务质量(quality of Service，qos)需求。由核心网设备用户面功能(user plane function，UPF)产生下行的qos flow，终端产生上行的qos flow，qos flow与DRB之间具有映射关系，可以由基站来配置，同一PDU session内的多个qos flow可以映射到同一DRB中，得到相同的转发处理，但是不同PDU session的qos flow不能映射到同一DRB中。
服务数据适配协议层(service data adaptation protocol，SDAP)负责将来自非接入层的qos flow映射到接入层的DRB上。对于上行数据，基站会将qos flow中先收到的数据单元优先提交给核心网设备，对于下行数据，基站会将qos flow中先收到的数据单元优先提交给UE，在这种通信架构下，如何保障切换时的正常通信是一个值得考虑的问题。
发明内容
本申请公开了一种切换方法，保障通信的正常进行。
本申请的第一方面提供了一种切换方法，包括：
目标基站接收源基站发送的基站切换请求，该切换请求中携带有第一指示信息，第一指示信息可以指示源基站的服务质量流qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB，qos flow对应的DRB从第一DRB变化为第二DRB表示qos flow从映射到第一DRB上传输变化为了映射到第二DRB上传输。
目标基站接收该切换请求后可以知道源基站上有qos flow需要转移到目标基站，且qos flow对应的DRB发生了变化。
目标基站向源基站发送隧道的信息，以便源基站利用该隧道向目标基站发送qos flow中对应的DRB变化为第二DRB后的数据单元，该数据单元由于映射关系转变缓存在源基站的SDAP层中。
在本实施例中，qos flow中对应的DRB变化为第二DRB后的数据单元即为qos flow中通过第二DRB传输的数据单元。
本申请实施例具有以下优点：目标基站接收源基站发送的切换请求，该切换请求中包括第一指示信息，可以指示源基站所接收到qos flow对应的DRB由第一DRB变化为第二DRB，随后目标基站向源基站发送隧道的信息，以便源基站通过该隧道发送对应的DRB变化为所述第二DRB后的数据单元。在本实施例中，源基站通过在切换请求中携带第一指示信息，目标基站可以根据该第一指示信息确定数据单元所属qos flow对应的DRB由第一DRB变为了第二DRB，从而目标基站发送隧道的信息至源基站，以便源基站通过该隧道来转移数据单元，以保证qos flow中数据单元的按序上报，从而保证通信系统正常通信。
基于第一方面，在第一方面的第一种可实现方式中，所述第一指示信息用于指示所述源基站所接收的qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB包括：
对于上行数据：UE通过映射至第一DRB发送到源基站的qos flow，变化为通过映射至DRB2发送到源基站，同时，由于映射关系转变，源基站的SDAP层接收第二DRB中的该qos flow的数据单元后，将这些数据单元缓存在源基站的SDAP层中。
对于下行数据：源基站通过映射至DRB1发送到UE的qos flow，变化为通过映射至DRB2发送到源基站，同时，由于映射关系转变，源基站会将需要通过DRB2发送的qos flow的数据单元缓存在源基站的SDAP层中。
基于第一方面及其第一方面的第一种可实现方式中任一，在第一方面的第二种可实现方式中，所述方法还包括：
目标基站获取结束指示，该结束指示用于指示UE的SDAP实体停止映射qos flow至所述第一DRB。
目标基站获取结束指示的方式为：一种情况为：由于无线通信信道的变化影响，UE给源基站发送的第一数据单元中的一些数据包没有被源基站正确接收，源基站只能将收到的数据包和结束指示转移给目标基站，同时UE会通过第一DRB继续重新发送这些没有被源基站正确接收的数据包，发送这些数据包时UE还会通过第一DRB重新给目标基站发送该结束指示。另一种情况为：源基站完全接收到了第一数据单元，源基站将第一数据单元和结束指示发送给目标基站。
对于上行数据，当目标基站的SDAP层收到结束指示时，目标基站根据该指示信息得知通过第一DRB传输的数据单元已全部接收完成，进一步也可以得知，已经将第一数据单元提交给了核心网设备，随后，目标基站再将第二数据单元发送至核心网设备。
在本实施例中，对于上行数据，目标基站接收到结束指示后再发送数据单元给核心网设备，保证了qos flow中数据单元的按序提交。
基于第一方面及其第一方面的第一种可实现方式中任一，在第一方面的第三种可实现方式中，所述方法还包括：
对于下行数据，目标基站在确定映射到第一DRB的qos flow被UE接收后，目标基站将所述数据单元映射至第二DRB上，从而将该数据单元发送至UE。
其中，确定的方式可以是目标基站确定第一DRB上不存在qos flow时，即可确定映射到第一DRB的qos flow被UE接收了。
在本实施例中，对于下行数据，映射到第一DRB的qosflow被所述UE接收后，目标基站再发送数据单元给UE，保证了qos flow中数据单元的按序提交。
基于第一方面以及第一方面的第一种至第三种可实现方式中任一，在第一方面的第四种可实现方式中，当隧道为PDU session隧道时，隧道的信息包括qos flow对应的协议数据单元PDU会话session的标识，以便源基站根据隧道的信息确定是哪一个PDU会话的隧道的信息。
在本实施例中，通过在隧道的信息中包含PDU session的标识，有利于源基站根据隧道的信息确定是哪一个PDU会话的隧道的信息。
基于第一方面的第四种可实现方式，在第一方面的第五种可实现方式中，所述方法还包括：
若隧道为PDU session隧道，目标基站接收源基站转移的数据单元的同时，还需要接收源基站发送的第二指示信息，以便目标基站根据第二指示信息得知转移的数据单元为缓存在SDAP层中的数据单元，从而与其他非缓存在SDAP层中的数据单元进行区分。
在本实施例中，当隧道为PDU session隧道，源基站还可以发送第二指示信息以指示数据单元为缓存在SDAP层的数据单元，有利于方案实施。
基于第一方面以及第一方面的第一种至第四种可实现方式中任一，在第一方面的第六种可实现方式中，所述目标基站向所述源基站发送隧道的信息之前，所述方法还包括：所述目标基站为隧道分配地址。
在本实施例中，目标基站会为隧道分配地址，增加了方案的完整性。
基于第一方面以及第一方面的第一种至第三种可实现方式中任一，在第一方面的第七种可实现方式中，所述目标基站接收源基站发送的切换请求之后，所述方法还包括：
若隧道为DRB隧道，目标基站接收源基站转移的数据单元的同时，还需要接收源基站发送的序列号状态转移信息，该序列号状态转移信息包括所述数据单元的PDCP SN号。
在本实施例中，对于DRB隧道，源基站还会发送数据单元的序列号状态转移信息给目标基站，增加了方案的可实施性。
基于第一方面的第七种可实现方式，在第一方面的第八种可实现方式中，数据单元的SN号用于目标基站确定该数据单元为缓存在源基站的SDAP层中的数据单元，确定的方式为目标基站通过PDCP SN号的比特串指示该DRB隧道对应的DRB中第一个丢失的上行PDCP SDU对应的PDCP SN号之前的数据单元是否为缓存在SDAP层的数据单元。
在本实施例中，序列号状态转移信息中包括PDCP SN号，可以指示数据单元为缓存在SDAP层的数据单元，有利于方案实施。
本申请的第二方面提供了一种切换方法，包括：
源基站发送基站切换请求给目标基站，该切换请求中携带有第一指示信息，第一指示信息可以指示源基站的服务质量流qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB，以便目标基站根据第一指示信息可知qos flow与DRB的映射关系变化了，从而可以得知源基站的SDAP层中存在缓存的qos flow需要转移到目标基站。
qos flow对应的DRB从第一DRB变化为第二DRB表示qos flow从映射到第一DRB上传输变化为了映射到第二DRB上传输。
源基站接收目标基站发送的隧道的信息。
源基站利用该隧道向目标基站发送qos flow中对应的DRB变化为第二DRB后的数据 单元，该数据单元由于映射关系转变缓存在源基站的SDAP层中。在本实施例中，qos flow中对应的DRB变化为第二DRB后的数据单元即为qos flow中通过第二DRB传输的数据单元。
在本实施例中，源基站通过在切换请求中携带第一指示信息，目标基站可以根据该第一指示信息确定数据单元所属qos flow对应的DRB由第一DRB变为了第二DRB，从而目标基站发送隧道的信息至源基站，以便源基站通过该隧道来转移数据单元，以保证qos flow中数据单元的按序上报，从而保证了通信系统正常通信。
基于第二方面，在第二方面的第一种可实现方式中，所述第一指示信息用于指示所述源基站所接收的qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB包括：
对于上行数据：UE通过映射至第一DRB发送到源基站的qos flow，变化为通过映射至DRB2发送到源基站，同时，由于映射关系转变，源基站的SDAP层接收第二DRB中的该qos flow的数据单元后，将这些数据单元缓存在源基站的SDAP层中。
对于下行数据：源基站通过映射至DRB1发送到UE的qos flow，变化为通过映射至DRB2发送到源基站，同时，由于映射关系转变，源基站会将需要通过DRB2发送的qos flow的数据单元缓存在源基站的SDAP层中。
在本实施例中，分别对上行数据和下行数据中qos flow对应的DRB从第一DRB变化为第二DRB的含义进行了说明，有利于方案实施。
基于第二方面及其第二方面的第一种可实现方式中任一，在第二方面的第二种可实现方式中，隧道为PDU session隧道时，所述隧道的信息包括所述qos flow对应的协议数据单元PDU会话session的标识，以便源基站根据隧道的信息确定是哪一个PDU会话的隧道的信息。
在本实施例中，通过在隧道的信息中包含PDU session的标识，有利于源基站根据隧道的信息确定是哪一个PDU会话的隧道的信息。
基于第二方面的第二种可实现方式，在第二方面的第三种可实现方式中，所述源基站接收所述目标基站发送的隧道的信息之后，所述方法还包括：
若隧道为PDU session隧道，源基站还需要发送第二指示信息至目标基站，以便目标基站根据第二指示信息得知转移的数据单元为缓存在SDAP层中的数据单元，从而与其他非缓存在SDAP层中的数据单元进行区分。
在本实施例中，当隧道为PDU session隧道，源基站还可以发送第二指示信息以指示数据单元为缓存在SDAP层的数据单元，有利于方案实施。
基于第二方面及其第二方面的第一种可实现方式中任一，在第二方面的第四种可实现方式中，所述源基站接收所述目标基站发送的隧道的信息之后，所述方法还包括：
若隧道为DRB隧道，源基站转移数据单元的同时，源基站还需要发送序列号状态转移信息至所述目标基站，该序列号状态转移信息包括所述数据单元的PDCP SN号。
在本实施例中，对于DRB隧道，源基站还会发送数据单元的序列号状态转移信息给目标基站，增加了方案的可实施性。
基于第二方面的第四种可实现方式，在第二方面的第五种可实现方式中，数据单元的SN号用于目标基站确定该数据单元为缓存在源基站的SDAP层中的数据单元，确定的方式 为目标基站通过PDCP SN号的比特串指示该DRB隧道对应的DRB中第一个丢失的上行PDCP SDU对应的PDCP SN号之前的数据单元是否为缓存在SDAP层的数据单元。
在本实施例中，序列号状态转移信息中包括PDCP SN号，可以指示数据单元为缓存在SDAP层的数据单元，有利于方案实施。
本申请的第三方面提供了一种加密方法，包括：
核心网设备发送选择指示至源基站，选择指示具体为倾向加密指示，倾向加密指示代表由基站来决定是否进行加密。
源基站根据选择指示对qos flow进行加密或不进行加密。
源基站发送切换请求消息给目标基站，该切换请求消息为请求切换pdu session中的一些qos flow到目标基站，切换请求消息中还携带源基站操作指示，源基站操作指示用于指示源基站执行了加密操作或没有执行加密操作。
目标基站根据源基站的操作指示对收到的一些qos flow进行加密或不进行加密。
可选的，源基站操作指示可以包括选择指示和信元，信元用于表示源基站对qos flow进行了加密或没有进行加密；或源基站操作指示也可以为：源基站根据自身操作将核心网设备发送的加密指示进行修改得到的需要加密指示或不需要加密指示。
在本实施例中，若源基站对qos flow进行了加密，会发送源基站的操作指示至目标基站，以便目标基站能根据该操作指示执行相应的加密操作，保证了加密操作在源基站和目标基站的一致性。
本申请的第四方面提供了一种完整性保护方法，包括：
核心网设备发送选择指示至源基站，选择指示具体为该选择指示为倾向完整性保护指示，倾向完整性保护指示代表由基站来决定是否进行完整性保护。
源基站根据选择指示对qos flow进行完整性保护或不进行完整性保护。
源基站发送切换请求消息给目标基站，该切换请求消息为请求切换pdu session中的一些qos flow到目标基站，切换请求消息中还携带源基站操作指示，源基站操作指示用于指示源基站执行了完整性保护操作或没有执行完整性保护操作。
目标基站根据源基站的操作指示对收到的qos flow进行完整性保护或不进行完整性保护。
在本实施例中，源基站操作指示可以包括选择指示和信元，信元用于表示源基站对qos flow进行了完整性保护或没有进行完整性保护；或源基站操作指示也可以为：源基站根据自身操作将核心网设备发送的完整性保护指示进行修改得到的需要完整性保护指示或不需要完整性保护指示。
在本实施例中，若源基站对qos flow进行了完整性保护，会发送源基站的操作指示至目标基站，以便目标基站能根据该操作指示执行相应的完整性保护操作，保证了完整性保护操作在源基站和目标基站的一致性。
本申请第五方面提供了一种密钥处理方法，包括：
用户设备UE接收主基站MN发送的第一计数值，所述第一计数值为第一双链接DC方式下的辅基站计数器SN counter的计数值，且所述第一计数值为大于或等于零的正整数，所述第一DC方式为所述MN为所述UE所配置的DC方式；
当所述UE释放所述第一DC方式时，所述UE保留所述第一计数值；
所述UE接收所述MN发送的第二计数值，所述第二计数值为第二DC方式下的SN counter的计数值，且所述第二计数值为大于或等于零的正整数，所述第二DC方式为所述MN为所述UE所配置的DC方式；
所述UE根据所述第一计数值判断所述第二计数值是否异常；
当所述第二计数值异常时，所述UE发送配置失败标识信息至所述MN。
在本实施例中，UE通过第一计数值判断第二计数值是否异常，若MN配置了相同的计数值，则UE会发送配置失败标识信息至MN，以避免在不同DC方式下，MN衍生得到了相同的S-key，保证了空口的通信安全。
本申请第六方面提供了一种密钥处理方法，包括：
所述主基站MN向用户设备UE发送的第一计数值，所述第一计数值为第一双链接DC方式下的辅基站计数器SN counter的计数值，且所述第一计数值为大于或等于零的正整数，所述第一DC方式为所述MN为所述UE所配置的DC方式；
所述MN向所述UE发送的第二计数值，所述第二计数值用于，所述UE根据所述UE释放所述第一DC方式时所保留的所述第一计数值判断所述第二计数值是否异常，所述第二计数值为第二DC方式下的SN counter的计数值，且所述第二计数值为大于或等于零的正整数，所述第二DC方式为所述MN为所述UE所配置的DC方式；
当所述第二计数值异常时，所述MN接收所述MN发送的配置失败标识信息。
在本实施例中，MN通过向UE发送的第一计数值，在MN发送第二计数值给UE后，UE可以根据第一计数值判断第二计数值是否异常，从而UE会发送配置失败标识信息至MN，以避免在不同DC方式下，MN衍生得到了相同的S-key，保证了空口的通信安全。
本申请第七方面提供了一种基站，包括：
接收单元，用于接收源基站发送的切换请求，所述切换请求包括第一指示信息，所述第一指示信息用于指示所述源基站的服务质量流qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB；
发送单元，用于与向所述源基站发送隧道的信息，所述隧道用于供目标基站接收所述源基站发送的数据单元，所述数据单元为所述qos flow中对应的所述DRB变化为所述第二DRB后的数据单元。
基于第七方面，在第七方面的第一种可实现方式中，所述第一指示信息用于指示所述源基站所接收的qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB包括：
所述第一指示信息用于指示所述源基站所接收的来自于用户设备UE的所述qos flow，从映射至所述第一DRB变化为映射至所述第二DRB，所述qos flow为由于对应的所述DRB变化而缓存在所述源基站的服务数据适配协议SDAP层中的qos flow；
或，所述第一指示信息用于指示所述源基站向所述UE发送的所述qos flow，从映射至所述第一DRB变化为映射至所述第二DRB，所述qos flow为由于对应的所述DRB变化而缓存在所述源基站的SDAP层中的qos flow。
基于第七方面及其第七方面的第一种可实现方式中任一，在第七方面的第二种可实现方式中，所述接收单元，还用于获取结束指示，所述结束指示用于指示所述UE的SDAP 实体停止映射所述qos flow至所述第一DRB；
向所述核心网设备发送所述数据单元。
基于第七方面及其第七方面的第一种可实现方式中任一，在第七方面的第三种可实现方式中，所述发送单元，还用于在映射到所述第一DRB的所述qos flow被所述UE接收后，通过所述第二DRB向所述UE发送所述数据单元。
基于第七方面及其第七方面的第一种至第三种可实现方式中任一，在第七方面的第四种可实现方式中，所述隧道的信息包括所述qos flow对应的协议数据单元PDU会话session的标识。
基于第七方面的第四种可实现方式，在第七方面的第五种可实现方式中，所述接收单元，还用于接收来自所述源基站的第二指示信息，所述第二指示信息用于所述目标基站确定所述数据单元为由于对应的所述DRB变化而缓存在所述源基站的所述SDAP层中的数据单元。
基于第七方面及其第七方面的第一种至第四种可实现方式中任一，在第七方面的第六种可实现方式中，所述基站还包括：
地址分配单元，用于为所述隧道分配地址。
基于第七方面及其第七方面的第一种至第三种可实现方式中任一，在第七方面的第七种可实现方式中，所述接收单元，还用于接收来自所述源基站的序列号状态转移信息，所述序列号状态转移信息包括所述数据单元的SN号。
基于第七方面的第七种可实现方式，在第七方面的第八种可实现方式中，所述数据单元的SN号用于所述目标基站确定所述数据单元为由于对应的所述DRB变化而缓存在所述源基站的所述SDAP层中的数据单元。
本申请第八方面提供了一种基站，包括：
发送单元，用于发送切换请求至目标基站，所述切换请求包括第一指示信息，所述第一指示信息用于指示所述源基站的服务质量流qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB；
接收单元，用于接收所述目标基站发送的隧道的信息；
所述发送单元，还用于通过所述隧道发送所述数据单元至所述目标基站，所述数据单元为所述qos flow中对应的所述DRB变化为所述第二DRB后的数据单元。
基于第八方面，在第八方面的第一种可实现方式中，所述第一指示信息用于指示所述源基站所接收的qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB包括：
所述第一指示信息用于指示所述源基站所接收的来自于用户设备UE的所述qos flow，从映射至所述第一DRB变化为映射至所述第二DRB，所述qos flow为由于对应的所述DRB变化而缓存在所述源基站的服务数据适配协议SDAP层中的qos flow；
或，所述第一指示信息用于指示所述源基站向所述UE发送的所述qos flow，从映射至所述第一DRB变化为映射至所述第二DRB，所述qos flow为由于对应的所述DRB变化而缓存在所述源基站的SDAP层中的qos flow。
基于第八方面及其第八方面的第一种可实现方式中任一，在第八方面的第二种可实现方式中，所述隧道的信息包括所述qos flow对应的协议数据单元PDU会话session的标识。
基于第八方面的第二种可实现方式，在第八方面的第三种可实现方式中，所述发送单元，还用于发送第二指示信息至所述目标基站，所述第二指示信息用于指示所述数据单元为由于对应的所述DRB变化而缓存在所述源基站的所述SDAP层中的数据单元。
基于第八方面及其第八方面的第一种可实现方式中任一，在第八方面的第四种可实现方式中，所述发送单元，还用于发送序列号状态转移信息至所述目标基站，所述序列号转移信息包括所述数据单元的SN号。
基于第八方面的第四种可实现方式，在第八方面的第五种可实现方式中，所述数据单元的SN号用于所述目标基站确定所述数据单元为由于对应的所述DRB变化而缓存在所述源基站的所述SDAP层中的数据单元。
本申请第九方面提供了一种基站，其特征在于，包括：存储器、收发器以及处理器；
其中，所述存储器用于存储程序和指令；
所述收发器用于在所述处理器的控制下接收或发送信息；
所述处理器用于执行所述存储器中的程序；
所述总线系统用于连接所述存储器、所述收发器以及所述处理器，以使所述存储器、所述收发器以及所述处理器进行通信；
其中，所述处理器用于调用所述存储器中的程序指令，执行如权利要求第一方面、第一方面的第一种至第八种可实现方式、第二方面以及第二方面的第一种以及第五种可实现方式中任一种可实现方式所述的方法。
基于第九方面，在第九方面的第一种可实现方式中，所述基站还包括总线系统；
所述总线系统用于连接所述存储器、所述收发器以及所述处理器，以使所述存储器、所述收发器以及所述处理器进行通信。
本申请第十方面提供了一种计算机可读存储介质，包括指令，当所述指令在计算机上运行时，使得计算机执行如权利要求第一方面、第一方面的第一种至第八种可实现方式、第二方面以及第二方面的第一种以及第五种可实现方式中任一种可实现方式所述的方法。
本申请第十一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，使得计算机执行如权利要求第一方面、第一方面的第一种至第八种可实现方式、第二方面以及第二方面的第一种以及第五种可实现方式中任一种可实现方式所述的方法。
本申请第十二方面提供了一种通信芯片，所述通信芯片存储有指令，当所述通信芯片在通信装置上运行时，使得所述通信芯片执行如权利要求第一方面、第一方面的第一种至第八种可实现方式、第二方面以及第二方面的第一种以及第五种可实现方式中任一种可实现方式所述的方法。
本申请第十三方面提供了一种通信系统，包括第七方面、第七方面的第一种至第八种可实现方式、第八方面以及第八方面的第一种以及第五种可实现方式中任一种可实现方式所述的装置。
附图说明
图1(a)为本申请5G通信系统的架构图；
图1(b)为本申请映射关系改变时SDAP实体接收上行数据单元的示意图；
图1(c)为本申请映射关系改变时SDAP实体接收下行数据单元的示意图；
图2为本申请切换方法的一个实施例示意图；
图3为本申请切换方法的另一个实施例示意图；
图4为本申请切换方法的另一个实施例示意图；
图5为本申请切换方法的另一个实施例示意图；
图6为本申请切换方法的另一个实施例示意图；
图7为本申请切换方法的另一个实施例示意图；
图8(a)为本申请切换方法的另一个实施例示意图；
图8(b)为本申请切换方法的另一个实施例示意图；
图9为本申请对qos flow进行加密的一个实施例示意图；
图10为本申请对qos flow进行完整性保护的一个实施例示意图；
图11为本申请DC场景下密钥生成方法的一个实施例示意图；
图12为本申请基站的一种可能的结构；
图13为本申请基站的另一种可能的结构；
图14为本申请基站的另一种可能的结构。
具体实施方式
5G通信系统的结构如图1(a)所示，通信系统可以包括核心网(5GC)和接入网(NG-RAN)。核心网为UE提供5G核心网的功能。核心网包括核心网控制面网元(access and mobility management function，AMF)功能和核心网用户面网元(user plane function，UPF)功能。AMF主要负责终端的接入和移动性管理。UPF主要负责数据包的路由转发、服务质量(quality of service，Qos)管理等功能。
接入网可以包括基站，为UE提供无线接入服务。基站可以是连接到NGC的5G新无线电技术(new radio，NR)基站(gNB)。
本申请可以应用在图1(a)所示的通信系统中，也可以应用在其他通信系统中。本申请对此不做限定。
本申请的说明书和权利要求书及上述附图中的术语“第一”、“第二”、“第三”、“第四”等(如果存在)是用于区别类似的对象，而不必用于描述特定的顺序或先后次序。应该理解这样使用的数据在适当情况下可以互换，以便这里描述的本申请的实施例如能够以除了在这里图示或描述的那些以外的顺序实施。此外，术语“包括”和“具有”以及他们的任何变形，意图在于覆盖不排他的包含，例如，包含了一系列步骤或单元的过程、方法、系统、产品或设备不必限于清楚地列出的那些步骤或单元，而是可包括没有清楚地列出的或对于这些过程、方法、产品或设备固有的其它步骤或单元。
在本实施例中，PDU session隧道表示：为PDU session建立的隧道，DRB隧道表示：为每个DRB建立的隧道。
在本实施例中，对于上行数据而言，源基站的qos flow为源基站所接收的来自于UE的数据流，该上行的qos flow由UE的SDAP实体映射至DRB，从而发送至源基站，qos flow与DRB之间具有映射关系。在qos flow映射至DRB的过程中若发生映射关系转变，例如 qos flow从映射至DRB1变化为映射至DRB2，则qos flow中对应为DRB2的第二数据单元可能会先到达源基站，而qos flow中对应为DRB1的第一数据单元随后到达源基站，源基站的SDAP层会缓存从DRB2上收到的qos flow的第二数据单元。如图1(b)所示，在上行方向，终端侧的SDAP层计划将qos flow的数据单元packet_1/2/3和packet_4/5/6均映射到DRB1，在SDAP层把packet_1/2/3映射到DRB1之后，此时若改变qos flow与DRB的映射关系，变为将qos flow的数据单元映射到DRB2上，即SDAP层把qos flow之后的数据单元packet_4/5/6从映射到DRB1改变为映射到DRB2，映射关系改变时，很可能会发生数据乱序的现象，例如基站的SDAP层可能在DRB2上先收到该qos flow的packet_4/5/6，但还没收到DRB1上的packet_1/2/3，这种情况下基站会先递交优先收到的数据单元，从而导致数据单元递交乱序。本申请在发生基站切换时为避免数据单元的乱序，可以在确定第一数据单元例如packet_1/2/3已上报核心网设备后再将第二数据单元packet_4/5/6上报核心网设备。可选的，UE的SDAP实体确定上行的qos flow由DRB1变化为DRB2的方式包括：UE收到源基站的RRC消息，该消息通知UE上行qos flow与DRB之间的映射关系改变了。或者UE收到基站的数据包，该数据包中携带了指示信息，指示UE该上行qos flow与DRB之间的映射关系改变了。
对于下行而言，源基站的qos flow为源基站发送给UE的数据流，该qos flow由源基站的SDAP实体映射至DRB，从而发送给UE。qos flow与DRB之间具有映射关系。如图1(c)所示，在qos flow映射至DRB的过程中若发生映射关系转变，例如qos flow从映射至DRB1变为映射至DRB2，qos flow中映射到DRB2上的packet_4/5/6比映射到DRB1的packet_1/2/3先到达UE。为保证该qos flow的数据单元在UE侧按序提交，第一数据单元为qos flow中第二数据单元之前的数据单元，第二数据单元会先缓存在源基站的SDAP层。
请参照图2，对本申请的切换方法进行说明。切换方法可以包括如下步骤：
201、目标基站接收源基站发送的切换请求。
当发生基站切换，目标基站首先接收源基站的切换请求，该切换请求中携带有第一指示信息，第一指示信息用于指示源基站的服务质量流qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB。
源基站需要通知目标基站对应的qos flow与DRB之间的映射关系，可以是映射关系改变之后的映射关系，也可能是改变之前的映射关系，也可能是同时通知改变之前和改变之后的映射关系。映射关系可以区分上下行。
在本实施例中，该第一指示信息具体的形式可能是请求建立PDU session隧道或DRB隧道。第一指示信息也可以区分上、下行。例如可能是请求建立上行PDU session隧道或上行DRB隧道，或者请求建立下行PDU session隧道或下行DRB隧道。
该第一指示信息可以指示源基站的SDAP层中缓存有qos flow的上行或下行数据需要处理，例如指示SDAP层有上行数据需要特殊处理或者下行数据需要特殊处理，或者上、下行都有数据需要特殊处理。或者第一指示信息还可以指示源基站在基站切换前，还没有完成qos flow的重新映射。或者第一指示信息还可以指示源基站的SDAP层中缓存有上行或下行数据。
可选的，第一指示信息还可以区分上下行指示信息，即指示源基站的服务质量流qos  flow上行对应的无线数据承载DRB从第一DRB变化为第二DRB，和/或指示源基站的服务质量流qos flow下行对应的无线数据承载DRB从第一DRB变化为第二DRB。
在本实施例中，qos flow对应的DRB从第一DRB变化为第二DRB具体表示：
对于上行数据：UE通过将qos flow映射至第一DRB发送给源基站，变化为通过将qos flow映射至DRB2发送给源基站。由于映射关系转变，源基站的SDAP层接收第二DRB中的qos flow的数据单元后，将这些数据单元缓存在源基站的SDAP层中。对于下行数据：源基站通过映射至DRB1发送给UE的qos flow，变化为通过映射至DRB2发送给UE。由于映射关系转变，源基站会将通过第二DRB发送的数据单元缓存在源基站的SDAP层中。
202、目标基站向源基站发送隧道的信息。
目标基站确认qos flow与DRB映射关系发生了转变，会建立隧道，并为该隧道分配地址。随后将隧道的信息发送给源基站。该隧道的信息中包括隧道的传输层地址以及GPRS隧道协议的隧道端点标识符(GPRS tunnelling protocol tunnel endpoint ID，GTP-TEID)。可选的，目标基站发送的隧道的信息可以区分上、下行，即上行的隧道的信息，和/或下行的隧道的信息，该隧道是用于转移SDAP层缓存数据而建立的。
目标基站发送隧道的信息给源基站，用于源基站转移qos flow中对应的DRB变化为第二DRB后的数据单元。该数据单元属于qos flow，也缓存在源基站的SDAP层。在本实施例中，该隧道可以为PDU session隧道，也可以为DRB隧道。若该隧道为PDU session隧道，隧道的信息中包括qos flow对应的协议数据单元PDU会话session的标识。源基站可以根据隧道的信息确定是哪一个PDU会话的隧道的信息。若该隧道DRB隧道，隧道的信息中包括qos flow对应的DRB标识。源基站可以根据隧道的信息确定是哪一个DRB的隧道的信息。若该隧道是DRB隧道，源基站还可以发送序列号状态转移信息给目标基站。该隧道还可能为其他类型的隧道，具体此处不做限定，且对于上行数据而言，本身不存在PDU session隧道，通过建立PDU session隧道，在映射关系转变时可以同步实现基站切换，并且不会发生数据单元的乱序的问题。对于下行数据而言，本身存在PDU session隧道，本申请中目标基站可以重新建立PDU session隧道转移qos flow。对于上行和下行数据而言，本身都存在DRB隧道，本申请中目标基站可以利用原有的DRB隧道转移qos flow。
在本实施例中，源基站通过在切换请求中携带第一指示信息，目标基站可以根据该第一指示信息确定数据单元所属qos flow对应的DRB由第一DRB变为第二DRB。目标基站发送隧道的信息给源基站，源基站通过该隧道来转移数据单元，以保证qos flow中数据单元的按序上报，从而保证正常通信。
基于上述图2的切换方法，本实施例中的隧道可以为PDU session隧道，也可以为DRB隧道，下面分别进行说明。
首先需要说明的是，下面图3至图6中所述的第一数据单元为qos flow中对应的无线数据承载DRB为第一DRB时的数据单元，第二数据单元为qos flow中对应的DRB变化为第二DRB后的数据单元，第一数据单元和第二数据单元属于同一个qos flow且，由于映射关系转变第二数据单元缓存在源基站的SDAP层，在时序上第一数据单元为第二数据单元之前的数据单元。
一、隧道为PDU session隧道。
A：请参照图3，对于上行数据而言，源基站通过在切换请求中携带第一指示信息，以便目标基站为转移由于映射关系转变而缓存在源基站的SDAP层中的qos flow建立PDU session隧道，从而在映射关系转变时也可以发生基站切换，且保证数据单元的按序上报。
301、UE向源基站发送qos flow。
UE将qos flow映射至第一DRB，从而通过第一DRB发送第一数据单元至源基站。如果源基站通知UE改变qos flow的上行的映射关系，即qos flow与DRB映射关系发生了转变，UE生成结束指示，UE在第一DRB中发送该结束指示。该结束指示可以为协议数据单元结束指示(end marker PDU)，用于指示UE的SDAP实体已经停止映射qos flow至第一DRB，或者指示UE的qos flow在第一DRB中已发送结束。可选的，当源基站收到该结束指示时，源基站就知道该qos flow的数据在第一DRB中已发送结束。
随后，UE将qos flow映射至第二DRB，从而通过第二DRB发送第二数据单元至源基站，源基站将第二数据单元缓存在SDAP层中。UE通过DRB向源基站发送qos flow的过程中，由于qos flow与DRB映射关系转变，源基站可能先收到第二数据单元再收到第一数据单元。
302、源基站发送切换请求至目标基站。
本实施例步骤与上述实施例步骤201类似，具体此处不再赘述。
303、目标基站发送PDU session隧道的信息至源基站。
目标基站根据切换请求可知qos flow与DRB映射关系发生了转变，目标基站建立PDU session隧道，并为该隧道分配地址，随后将PDU session隧道的信息发送给源基站，用于源基站转移第二数据单元。该PDU session隧道的信息中包括PDU session隧道的传输层地址以及GTP-TEID。可选的，隧道的信息中还包括qos flow对应的协议数据单元PDU会话session的标识，以便源基站根据隧道的信息确定是哪一个PDU会话的隧道的信息。该PDU session隧道为传输上行数据的隧道。
需要说明的是，对于上行数据，本身不存在PDU session隧道，目标基站通过新建PDU session隧道后，将PDU session隧道的信息发送给源基站。
304、源基站通过PDU session隧道发送第二数据单元至目标基站。
源基站通过PDU session隧道将第二数据单元发送至目标基站。第二数据单元为上行数据的数据单元。
可选的，源基站在第二数据单元的GPRS用户面隧道协议(GPRS tunnelling protocol user plane，GTP-U)报头或者扩展报头中携带指示，指示第二数据单元为SDAP层缓存的数据单元。
可选的，源基站还可以在第二数据单元的GTP-U报头或者扩展报头中携带qos flow标号，以表示该数据单元为PDU session隧道中哪个qos flow的数据单元。
可选的，对于源基站没有全部接收到第一数据单元的数据包的情形，由于无线通信信道的变化影响，UE给源基站发送的第一数据单元中的一些数据包没有被源基站正确接收，而第一数据单元中的这些数据包之后的数据包被源基站正确接收，源基站并不能把这些正确接收的数据包提交给核心网设备。比如packet_1没有被正确接收，而packet_2/3被基站 正确接收，packet_2/3不能被源基站提交核心网设备。源基站需要通过这些数据包所在的DRB对应的隧道把packet_2/3也转移到目标基站，UE会在DRB1中重新给目标基站发送packet_1。目标基站在收到packet_1之后，才会把packet_1/2/3提交给核心网设备。需要说明的是，上述无线信道变化的情况下，将源基站所接收到的数据包(例如上述packet_2/3)转给目标基站的同时，由于UE是通过DRB1发送结束指示给源基站，如果源基站正确接收到该结束指示，源基站会通过DRB1对应的DRB隧道把该结束指示也转给目标基站，源基站转给目标基站的数据包及结束指示的形式是PDCP SDU，目标基站收到这些PDCP SDU之后(一般缓存在PDCP层)，需要等这些数据包之前的数据包(例如上述packet_1)被也被正确接收之后，再提交给目标基站的SDAP层。
可选的，对于源基站接收到第一数据单元的全部数据包的情形，由源基站将第一数据单元提交核心网设备，同时源基站转移结束指示给目标基站。
可选的，在步骤304之前或者之后，源基站发送切换命令给UE，通知UE进行基站间切换。UE收到对应的切换命令之后，会在目标基站的小区中进行接入。
305、目标基站获取结束指示。
目标基站获取结束指示是指目标基站的SDAP层接收到结束指示。
无论是否受到无线通信信道变化的影响，源基站正确接收UE发送的结束指示后，源基站会把该结束指示转移给目标基站。需要说明的是，源基站是以PDCP SDU形式把该结束指示转移给目标基站。
由于无线通信信道的变化影响，如果源基站没有正确接收UE发送的结束指示，此时UE还会通过DRB1重新给目标基站发送该结束指示。需要说明的是UE重传的是该结束指示对应的PDCP SDU；
306、目标基站根据结束指示发送第二数据单元至核心网设备。
当目标基站的SDAP层收到结束指示时，目标基站根据该指示得知通过第一DRB传输的数据单元已全部接收完成。进一步也可以得知，源基站或目标基站已经将第一数据单元提交给了核心网设备。随后，目标基站再将第二数据单元发送至核心网设备，以此保证第二数据单元在第一数据单元之后再发送给核心网设备，保证了数据单元之间的按序上报。
在本实施例中，源基站通过在切换请求中携带第一指示信息，目标基站可以根据该第一指示信息确定qos flow对应的DRB由第一DRB变为了第二DRB，从而目标基站发送PDU session隧道的信息至源基站，并通过该隧道来转移第二数据单元，目标基站在收到结束指示后，再提交第二数据单元至核心网设备，从而保证了qos flow中数据单元按序提交，进而保证了通信系统正常通信。
B：请参照图4，对于下行数据而言，源基站通过在切换请求中携带第一指示信息，以便目标基站为转移由于映射关系转变而缓存在源基站的SDAP层中的qos flow建立PDU session隧道，从而在映射关系转变时也可以发生基站切换，且保证数据单元的按序上报。
401、源基站向UE发送第一数据单元。
源基站将qos flow映射至第一DRB上，从而将第一数据单元发送给UE。
随后，源基站改变qos flow的下行的映射关系，即qos flow与DRB映射关系发生了转 变，qos flow映射的DRB从第一DRB变为第二DRB。源基站会将需要通过第二DRB发送的qos flow的第二数据单元缓存在源基站的SDAP层中。
402、源基站发送切换请求给目标基站。
本实施例步骤与上述实施例步骤201类似，具体此处不再赘述。
403、目标基站发送PDU session隧道的信息给源基站。
目标基站根据切换请求可知qos flow与DRB映射关系发生了转变，目标基站建立PDU session隧道，并为该隧道分配地址，随后将PDU session隧道的信息发送给源基站，用于源基站转移第二数据单元。该PDU session隧道的信息中包括PDU session隧道的传输层地址以及GTP-TEID。可选的，隧道的信息中还包括qos flow对应的协议数据单元PDU会话session的标识，以便源基站根据隧道的信息确定是哪一个PDU会话的隧道的信息。该PDU session隧道为传输下行数据的隧道。
需要说明的是，对于下行数据，基站之间本身也存在PDU session隧道，目标基站可以通过新建PDU session隧道后，将PDU session隧道的信息发送给源基站。也可以使用现有的PDU session隧道，将PDU session隧道的信息发送给源基站，源基站在通过现有的PDU session隧道转移第二数据单元时，需要增加指示信息，用于指示第二数据单元为SDAP层缓存的数据单元。
404、源基站通过PDU session隧道发送第二数据单元至目标基站；
源基站通过PDU session隧道将第二数据单元发送至目标基站。第二数据单元为下行数据的数据单元。
可选的，源基站在第二数据单元的GPRS用户面隧道协议报头或者扩展报头中携带指示，指示第二数据单元为SDAP层缓存的数据单元。
可选的，源基站还可以在第二数据单元的GTP-U报头或者扩展报头中携带qos flow标号，以表示该数据单元为PDU session隧道中哪个qos flow的数据单元。
可选的，由于无线通信信道的变化影响，源基站给UE发送的第一数据单元中的一些数据包没有被UE正确接收，源基站需要把这些数据包通过DRB隧道转移给目标基站。比如packet_2/3没有被UE正确接收，源基站需要通过DRB隧道把packet_2/3也转移到目标基站。目标基站会在DRB1中重新给UE发送packet_2/3。
405、在目标基站确定映射至第一DRB的qos flow被UE接收后，目标基站发送第二数据单元至UE。
目标基站根据第一指示信息确定映射关系改变前与qos flow对应的DRB为第一DRB，判断映射到第一DRB的qos flow(即第一数据单元)是否被UE接收，判断的方式可以是：目标基站判断第一DRB上是否还存在qos flow，若不存在，则证明第一数据单元已经被UE接收，或目标基站设置定时器，定时器超时之后，就认为第一数据单元已经被UE接收，目标基站判断映射到第一DRB的qos flow是否UE接收还可以为其他的方式，具体此处不作限定。
若映射到第一DRB的qos flow已经UE接收了，目标基站将qos flow映射第二DRB上，从而将第二数据单元发送至UE，以此保证第二数据单元在第一数据单元之后再发送给UE，保证了数据单元之间的按序上报。
在本实施例中，对于下行数据，源基站通过在切换请求中携带第一指示信息，目标基站可以根据该第一指示信息确定数据单元所属qos flow对应的DRB由第一DRB变为了第二DRB，从而目标基站发送PDU session隧道的信息至源基站，源基站与目标基站间通过该PDU session隧道来转移第二数据单元，以便目标基站在确定qos flow与第一DRB的映射关系结束后，第一数据单元已上报给了UE，目标基站再发送第二数据单元给UE，以保证qos flow中数据单元的按序上报，从而保证通信系统正常通信。
二、隧道为DRB隧道。
A：请参照图5，对于上行数据而言，源基站通过在切换请求中携带第一指示信息，以便目标基站为转移由于映射关系转变而缓存在源基站的SDAP层中的qos flow建立DRB隧道，并发送DRB隧道的信息至源基站，随后源基站通过控制面把序列号状态转移信息发给目标基站，通过DRB隧道发送第二数据单元至目标基站。目标基站根据序列号状态转移信息或者源基站转移第二数据单元携带的指示信息，可以知道哪些数据包是第二数据单元的数据包，从而在映射关系转变时也可以发生基站切换，且保证数据单元的按序上报。
501、UE向源基站发送qos flow；
502、源基站发送切换请求至目标基站；
本实施例步骤501至502与上述实施例步骤301至302类似，具体此处不再赘述。
503、目标基站发送DRB隧道的信息至源基站；
目标基站根据切换请求可知qos flow与DRB映射关系发生了转变，目标基站建立DRB隧道，并为该隧道分配地址，该DRB隧道可以为原有的DRB隧道，随后将DRB隧道的信息发送给至源基站，用于源基站转移第二数据单元。该DRB隧道的信息中包括DRB隧道的传输层地址以及GTP-TEID。可选的，隧道的信息中包括qos flow对应的DRB标识，以便源基站根据隧道的信息确定是哪一个DRB的隧道的信息。该DRB隧道为传输上行数据的DRB隧道。
504、通过DRB隧道向目标基站发送第二数据单元；
源基站获取DRB隧道的地址信息后，将缓存在源基站SDAP层的第二数据单元以包数据汇聚协议服务数据单元(packet data convergence protocol service data unit，PDCP SDU)的形式发给目标基站。第二数据单元为上行数据的数据单元。
在本实施例中，通过DRB隧道转移源基站的数据到目标基站，可以保证所转移数据的需无损切换。
可选的，源基站同时给目标基站发送第二数据单元的序列号状态转移信息，序列号状态转移信息具体为包数据汇聚协议序列号(packet data convergence protocol serial number，PDCP SN)信息，目标基站根据序列号状态转移信息可以知道该隧道中传输的哪些数据包是属于第二数据单元的数据包。可选的，源基站可以把在源基站的SDAP缓存的第二数据单元恢复为PDCP SDU，同时恢复该第二数据单元在PDCP层的PDCP SN号。
需要说明的是，在本实施例中，源基站与目标基站之间具有第一DRB对应的DRB隧道和第二DRB对应的DRB隧道。本申请中的DRB隧道可以和第二DRB对应的DRB隧道是同一个隧道。
同时本申请还通过第二数据单元的序列号状态转移信息指示源基站向目标基站发送的第二数据单元为缓存在源基站SDAP层中的数据单元，例如通过PDCP SN号的比特串指示该DRB隧道对应的DRB中第一个丢失的上行PDCP SDU对应的SN号之前的数据单元是否为缓存的SDAP层的数据单元，例如第一个丢失的数据单元对应的PDCP SN号为X，用比特串指示PDCP SN号X之前的属于该DRB中的数据单元是否为源基站SDAP层缓存的数据单元，可以用0表示数据单元为缓存在SDAP层的数据单元，用1表示数据单元不是缓存在SDAP层的数据单元，以便与源基站和目标基站间所转移的其他类别的数据单元即非缓存在SDAP层中的数据单元进行区分。或者反之可以用1表示数据单元为缓存在SDAP层的数据单元，用0表示数据单元不是缓存在SDAP层的数据单元。
可选的，在504之前或者之后，源基站发送切换命令给UE，通知UE进行基站间切换。UE收到对应的切换命令之后，会在目标基站的小区中进行接入。
可选的，源基站可以在通过DRB隧道转移第二数据单元时，携带一些指示信息，指示该数据单元为缓存在SDAP层的第二数据单元，以便与源基站和目标基站间所转移的其他类别的数据单元即非缓存在SDAP层中的数据单元进行区分。可选的，源基站在第二数据单元的GTP-U报头或者扩展报头中携带序列号状态指示信息。
可选的，源基站还可以在第二数据单元的GTP-U报头或者扩报头中携带qos flow标号，以表示该包为PDU session隧道中哪个qos flow的数据单元。
505、目标基站确定第二数据单元为缓存在源基站的SDAP层中的数据单元；
可选的，目标基站可以根据第二数据单元的序列号状态转移信息来确认第二数据单元为缓存在源基站的SDAP层中的数据单元。
可选的，目标基站也可以根据DRB隧道转移数据携带的指示信息来确认第二数据单元为缓存在源基站的SDAP层中的数据单元。
506、目标基站获取结束指示信息。
对于源基站没有全部接收到第一数据单元的数据包以及源基站全部接收到第一数据单元的数据包的情况下，第一数据单元提交核心网设备的可能情况以及目标基站获取结束指示的可能情况与上述实施例步骤304中对应描述类似，具体此处不再赘述。
本实施例步骤506与上述实施例步骤305类似，具体此处不再赘述。
507、目标基站根据结束指示发送第二数据单元至核心网设备。
本实施例步骤507与上述实施例步骤306类似，具体此处不再赘述。
在本实施例中，源基站通过DRB隧道发送第二数据单元至目标基站，同时将第二数据单元的序列号状态指示信息也发送至目标基站或在发送第二数据单元时携带指示信息，以便目标基站根据这些指示信息确定第二数据单元为由于映射关系改变而缓存在SDAP层的数据单元，从而在收到UE发送的结束指示后，即使没有收到第一数据单元，也可以将第二数据单元上报核心网设备，以保证第一数据单元和第二数据单元的按序上报。
B：请参照图6，对于下行数据而言，源基站通过在切换请求中携带第一指示信息，以便目标基站为转移由于映射关系转变而缓存在源基站的SDAP层中的qos flow建立DRB隧道，并发送DRB隧道的信息至源基站，随后源基站通过控制面把序列号状态转移信息发给 目标基站，通过DRB隧道发送第二数据单元至目标基站，目标基站根据序列号状态转移信息或者源基站转移第二数据单元携带的指示信息可以单独提交第二数据单元至UE，从而在映射关系转变时也可以发生基站切换，且保证数据单元的按序上报。
601、源基站向UE发送第一数据单元。
602、源基站发送切换请求至目标基站。
本实施例步骤601至602与上述实施例步骤401至402类似，具体此处不再赘述。
603、目标基站发送DRB隧道的信息至源基站；
本实施例步骤与上述实施例步骤503类似，不同的是，该DRB隧道为传输下行数据的DRB隧道，具体此处不再赘述。
604、源基站通过DRB隧道向目标基站发送第二数据单元。
本实施例步骤与上述实施例步骤504类似，不同的是，第二数据单元为下行数据的数据单元，具体此处不再赘述。
在本实施例中，通过DRB隧道转移源基站的数据到目标基站，可以保证所转移数据的需无损切换。
605、目标基站确定第二数据单元为缓存在源基站的SDAP层中的数据单元。
本实施例步骤与上述实施例步骤505类似，具体此处不再赘述。
606、在目标基站确定映射到第一DRB的qos flow被UE接收后，目标基站发送第二数据单元至UE。
本实施例步骤606与上述实施例步骤405类似，具体此处不再赘述。
在本实施例中，源基站通过DRB隧道发送第二数据单元至目标基站，同时将第二数据单元的序列号状态指示信息也发送至目标基站或在发送第二数据单元时携带指示信息，以便目标基站根据序列号状态指示信息确定第二数据单元为由于映射关系改变而缓存在SDAP层的数据单元，从而在收到UE发送的结束指示后，即使没有收到第一数据单元，也可以将第二数据单元UE，以保证第一数据单元和第二数据单元的按序上报。
上面从目标基站的角度对本申请实施例进行了叙述，请参照图7，下面将从源基站的角度对本申请进行说明。
701、源基站发送切换请求至目标基站。
在本实施例中，切换请求包括第一指示信息，第一指示信息用于指示源基站的服务质量流qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB。
第一指示信息的具体形式以及qos flow对应的DRB从第一DRB变化为了第二DRB所表示的具体含义与上述实施例步骤201类似，具体此处不再赘述。
702、源基站接收目标基站发送的隧道的信息。
在本实施例中，目标基站建立隧道后为该隧道分配地址，并将隧道的信息发送至目标基站，该隧道的信息中包括传输层地址以及GPRS隧道协议的隧道端点标识符GTP-TEID。可选的，目标基站发送的隧道的信息可以区分上下行，即上行的隧道的信息，和/或下行的隧道的信息。
该隧道可以为PDU session隧道，也可以为DRB隧道，若该隧道为PDU session隧道， 隧道的信息中包括qos flow对应的协议数据单元PDU会话session的标识，以便源基站确定是哪一个PDU会话的隧道的信息，若该隧道DRB隧道，隧道的信息中包括qos flow对应的DRB标识，以便源基站根据隧道的信息确定是哪一个DRB的隧道的信息，若该隧道DRB隧道，若该隧道DRB隧道，源基站还需要接收来自目标基站的序列号状态转移信息，序列号状态转移信息包括所述数据单元的PDCP SN号，PDCP SN号的作用与上述实施例类似，具体此处不再赘述。
703、源基站通过隧道发送数据单元至目标基站。
数据单元为qos flow中对应的DRB变化为第二DRB后的数据单元，qos flow中还存在qos flow对应的DRB变化前的数据单元。
源基站通过隧道发送数据单元至目标基站，从而对于上行数据，目标基站在收到UE发送的结束指示后，可以确定qos flow与第一DRB的映射关系结束已经结束，从而目标基站发送数据单元至核心网设备，以保证qos flow中数据单元的按序上报。对于下行数据，目标基站自己判断qos flow与第一DRB的映射关系是否结束，若是，目标基站再发送数据单元至UE，以保证qos flow中数据单元的按序上报。
在本实施例中，源基站通过发送携带第一指示信息的切换请求给目标基站，以便目标基站反馈隧道的信息，该隧道用于源基站转移qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB后的数据单元，从而保证qos flow中数据单元的按序上报。
参照图8(a)，本申请还提供了一种切换方法，由源基站将qos flow中对应的DRB变化为第二DRB后的第二数据单元上报核心网设备，目标基站将qos flow中对应的DRB为第一DRB的第一数据单元上报核心网设备，再由核心网设备对第一数据单元和第二数据单元进行排序。
801、源基站发送切换请求给目标基站。
源基站发送切换请求至目标基站，请求进行切换。
802、目标基站发送隧道的信息至源基站。
目标基站收到切换请求后建立隧道，随后发送隧道的信息至源基站，该隧道可以为DRB隧道，也可以为PDU session隧道，具体此处不作限定。
803、源基站发送第二数据单元和乱序指示信息至核心网设备。
由于源基站所接收的上行的qos flow与DRB的映射关系从第一DRB变化为了第二DRB，源基站首先收到qos flow中对应的DRB变化为第二DRB后UE通过第二DRB发送的第二数据单元，随后源基站再收到qos flow中对应的DRB映射关系变化前UE通过第一DRB发送的第一数据单元，第一数据单元和第二数据单元属于同一个qos flow，且qos flow由于映射关系转变缓存在源基站的SDAP层，在时序上第一数据单元为第二数据单元之前的数据单元。
发生基站切换时，源基站发送第二数据单元和乱序指示信息至核心网设备，该乱序指示信息用于指示源基站所上报的第二数据单元为按照异常顺序发送的数据单元，第二数据单元之前还有数据单元没有上报，乱序指示信息可以携带在第二数据单元的GTP-U的报头或者扩展头中。
804、源基站通过隧道发送第一数据单元至目标基站。
805、目标基站获取第一结束指示。
UE将qos flow映射至第一DRB，从而通过第一DRB发送第一数据单元至源基站，随后，源基站通知UE改变qos flow的上行的映射关系，即qos flow与DRB映射关系发生了转变。UE收到这个映射关系改变的通知之后，UE生成第一结束指示，UE在第一DRB中发送该第一结束指示。
可选的，如果源基站正确接收UE发送的第一结束指示，源基站会把该第一结束指示转移给目标基站。需要说明的是，源基站是以PDCP SDU形式把该第一结束指示转移给目标基站。
由于无线通信信道的变化影响，如果源基站没有正确接收UE发送的第一结束指示，此时UE还会通过第一DRB重新给目标基站发送该第一结束指示。需要说明的是UE重传的是该第一结束指示对应的PDCP SDU。
806、目标基站发送第一数据单元和第二结束指示至核心网设备。
当目标基站的SDAP层收到第一数据单元对应的数据时，目标基站会把这些数据发送给核心网。当目标基站的SDAP层收到UE发送的第一结束指示时，可以根据第一结束指示得知qos flow与第一DRB的映射关系结束了，目标基站会给核心网发送第二结束指示，核心网设备根据第二结束指示可知，qos flow中的映射关系改变前的数据单元已全部被核心网设备接收完毕。
807、核心网设备根据乱序指示信息和第二结束指示对第一数据单元和第二数据单元进行排序。
核心网设备根据第二结束指示确定第二数据单元之前的数据单元已接收完毕，同时根据乱序指示信息确定第一数据单元即为第二数据单元之前的数据单元，从而对第一数据单元和第二数据单元进行排序，以保证第一数据单元和第二数据单元之间的先后顺序，从而保证通信系统的正常通信。
当qos flow为下行数据流时，切换方式与上述图8(a)所述方式类似，参照图8(b)不同的是，目标基站无法收到UE发送的第一结束指示，而是目标基站自己判断映射到第一DRB的qos flow即第一数据单元是否被UE接收，判断的方式可以是：目标基站判断第一DRB上是否还存在qos flow，若不存在，则证明第一数据单元已经被UE接收，或目标基站设置定时器，定时器超时之后，就认为第一数据单元已经被UE接收，目标基站判断映射到第一DRB的qos flow是否UE接收还可以为其他的方式，具体此处不作限定。同时，第一数据单元和第二数据单元分别上报给UE，而不是核心网设备。
需要说明的是，以上图2至图8(b)所述实施例也适用于切换过程中通过核心网间接交互的场景，可以称为基于核心网和基站之间的接口的切换，比如源基站与目标基站之间的消息交互先要经过核心网设备，再到对端。
请参照图9，在双链接(dual connectivity，DC)场景中，源基站可能把一部分qos flow转移到目标基站上传输。当核心网设备请求建立PDU session时，基站向核心网设备发送的 加密指示(security indication)。该加密指示为倾向加密(preferred)指示、需要加密(required)指示以及不需要加密(not needed)指示中的一个。基站根据加密指示确定对PDU session的qos flow执行相应的操作。同样的，基站也可以向核心网设备发送的完整性保护指示(integrity protection indication)。该完整性保护指示为倾向完整性保护指示(preferred)指示、需要完整性保护指示(required)指示以及不需要完整性保护指示(not needed)指示中的一个。基站根据完整性保护指示确定对PDU session的qos flow执行相应的操作。其中，倾向指示代表由基站来决定是否进行加密或完整性保护，需要指示代表基站必须进行加密或完整性保护，不需要指示代表基站不进行加密或完整性保护。当把PDU session的一部分数据流从源基站切换到目标基站时，当核心网设备发送给源基站的指示为倾向完整性保护指示或倾向加密指示时，源基站若将这一指示发送给目标基站，可能会导致源基站进行了加密或完整性保护，但是目标基站并没有进行加密或完整性保护的情况发生。基于此，请参照图9，下面对本申请基站切换过程中qos flow的加密方式进行说明。
901、核心网设备发送选择指示至源基站。
核心网设备发送选择指示给源基站，该选择指示为上述倾向加密指示。
902、源基站根据选择指示对qos flow进行加密或不进行加密。
源基站根据选择指示选择对PDU session进行加密或不进行加密。
903、源基站发送切换请求消息给目标基站。
该切换请求消息请求切换pdu session中的一些qos flow到目标基站，请求消息中还携带源基站的操作指示。在DC场景下，当源基站切换到目标基站时，源基站会将PDU session中的一些qos flow转移到目标基站，同时会将源基站的操作指示发送给目标基站，以便目标基站根据该源基站的操作指示确定源基站是否进行了加密。
在本实施例中，源基站操作指示可以包括选择指示和信元。或源基站操作指示也可以为：源基站根据自身操作将核心网设备发送的加密指示进行修改得到的需要加密指示或不需要加密指示，比如把核心网给源基站的加密指示根据源基站当前是否对该pdu session进行了加密改为需要加密(required)指示或者不需要加密(not needed)指示。
904、目标基站根据源基站的操作指示对收到的qos flow进行加密或不进行加密。
目标基站根据源基站的操作指示对收到的一些qos flow进行加密或不进行加密的方式如下：
一种方式是：源基站会转发核心网设备发送给源基站的选择指示，同时携带信元，该信元用于表示源基站对qos flow进行了加密或没有进行加密，从而目标基站也对的收到的一些qos flow进行加密；另一种方式是：源基站将选择指示修改为加密指示或不加密指示，若源基站对qos flow进行了加密，则发送加密指示至目标基站，从而目标基站也对的收到的一些qos flow进行加密，若源基站没有对qos flow进行加密，则发送不加密指示至目标基站，从而目标基站也不对收到的一些qos flow进行加密。
在本实施例中，若源基站对qos flow进行了加密，会发送源基站的操作指示至目标基站，以便目标基站能根据该操作指示执行相应的加密操作，保证了加密操作在源基站和目标基站的一致性。
在本实施例中，请参照图10，完整性保护的情况与加密情况类似，同样的会发送源基站的操作指示至目标基站，以便目标基站能根据该操作指示执行相应的完整性保护操作，具体此处不再赘述。
基站可以通过双链接(DC)的方式为UE进行服务。在DC中，UE同时与两个基站进行通信，其中这两个基站分别称为主基站(master node，MN)和辅基站(secondary node，SN)。在MN与SN都连接4G核心网EPC的场景中，MN会为UE配置至少两种DC方式，同样的，在MN与SN都连接到5G核心网5GC的场景中或后续演进的移动网络中时，也存在至少两种DC方式。例如：
LTE DC和E-UTRA NR DC为4G核心网EPC的场景中的2种DC方式：
1、MN与SN都为LTE的基站eNB时，此时的DC方式称为LTE DC；
2、MN为LTE基站eNB，SN为NR基站gNB，此时的DC方式称为E-UTRA NR DC，简称为EN-DC。
NG EN-DC、NE-DC以及NR-NR DC为MN与SN都连接5G核心网5GC的场景中的3种DC方式：
1、MN为LTE的基站ng-eNB，SN为NR基站gNB，此时的DC方式称为NG EN-DC；
2、MN为NR基站gNB，SN为LTE基站ng-eNB，此时的DC方式称为NE-DC；
3、MN与SN均为NR基站gNB，此时的DC方式称为NR-NR DC。
为了保证空口的通信安全，一般来说，UE与MN通信使用的秘钥(key)与UE与SN通信使用的秘钥是不同的。为描述方便，将UE与MN通信使用的秘钥称为主秘钥(master key，M-key)，将UE与SN通信使用的秘钥称为辅秘钥(secondary key，S-key)。UE接入MN后，会得到M-key，后续MN会告知UE一个安全参数，用于UE基于该安全参数和M-key衍生得到S-key，该安全参数为SN计数器(counter)的计数值。在不同的DC方式中，该SN counter的具体名称可能不同。同时在不同的DC方式中，该SN counter在协议中的信元可能不同，但是所实现的功能是一致的。
为了保证空口通信安全，对于同一个UE，当从同一个M-key衍生得到S-key时，必须保障每次得到的S-key都是不同的。但是一种可能的情况是，MN可能会先后为UE配置2种或2种以上DC方式，每种DC方式的SN counter是单独维护和配置的，在该UE的M-key未改变的情况，由于每个SN counter可能均是从0或1逐次加1，这样导致在不同的DC方式中，可能存在UE使用相同的SN counter的计数值，那么在M-key也相同的情况下，这样就导致UE衍生得到了相同的S-key，进而不同的SN会使用相同的S-key与UE进行通信，影响了空口的通信安全。
本申请还提供了一种通信方法，以期保障通信安全。该方法可以包括如下二种方式。
方式1、不同DC方式下，UE的M-key是固定不变的，在MN为UE配置不同的DC时，为UE配置不同的SN counter的计数值，从而衍生得到不同的S-key。
方式2：不同DC方式下，MN将可配置的SN counter的取值范围错开，从而保证不同的DC方式使用不同的SN counter的计数值。
对于UE而言，为保证不同DC方式下，不同的SN使用不同的S-key与UE进行通信， 参照图11，可以使用如下方法：
1101、UE接收主基站MN发送的第一计数值，第一计数值为MN为UE配置第一DC方式时SN counter的计数值。
MN为UE配置第一DC方式时，给UE发送SN counter的第一计数值，第一计数值为大于或等于零的整数。
在本实施例中，第一DC方式为长期演进(long term evolution，LTE)DC、E-UTRA NR DC、NG EN-DC、NE-DC以及NR-NR DC中的任意一种方式，具体不做限定。
1102、当UE释放第一DC方式时，UE保留第一计数值。
在本实施例中，UE释放第一DC方式表示UE释放第一DC方式的辅基站的配置。这可以由UE自己主动释放，也可以由MN指示UE释放第一DC方式的配置。
辅基站的配置中包括第一计数值，但是UE释放第一DC方式时不会删除已存储的第一DC方式所对应的第一计数值。
1103、UE接收主基站MN发送的第二计数值，第二计数值为MN为UE配置第二DC方式时SN counter的计数值。
MN为UE配置第二DC方式时，给UE发送SN counter的第二计数值，第二计数值为大于或等于零的整数。
在本实施例中，第二DC方式为与第一DC方式不同的DC方式，第二DC方式为LTE DC、E-UTRA NR DC、NG EN-DC、NE-DC以及NR-NR DC中的任意一种方式，具体不做限定。
1104、UE根据第一计数值判断第二计数值是否异常。
在本实施例中，UE根据第一计数值判断第二计数值是否异常两种可实现的方式，包括：
1、UE判断接收到第二计数值之前时刻的计数值集合中，是否存在任意一个计数值与第二计数值相同，其中，第一计数值属于计数值集合。这种情况下，UE需要存储MN所配置的每一个SN counter的计数值。
若是，则确定第二计数值异常，否则第二计数值正常。
2、若第一计数值为第二计数值之前时刻的计数值集合中，MN所配置的最新的一个计数值，由于SN counter的计数值是逐次加1，MN之前配置过的计数值均小于或等于第一计数值，此时只需要第二计数值大于第一计数值，就可确定第二计数值未被MN使用过，第二计数值正常，若第二计数值小于第一计数值，则第二计数值异常。
这种情况下，UE只需要存储MN所配置的最新的SN counter的计数值。
例如，MN先为UE配置了LTE DC，并指示SN counter计数器的计数值为x1，UE基于M-key和计数值x1衍生得到用于与第一SN通信的第一S-key。随后，UE释放了LTE DC方式，同时UE删除LTE DC的配置，LTE DC的配置中包含计数值x1，但是UE并不会删除计数值x1。随后，MN为UE配置了EN-DC，并指示SN counter为数值x2，UE根据x1判断x2是否异常。
1105、当第二计数值异常时，UE发送配置失败标识信息至MN。
配置失败标识信息有如下两种发送方式：
UE触发重建立流程，与MN建立连接。
可选的，后续重建立成功后，UE将配置失败标识信息上报给MN，配置失败的原因可以为SN counter配置失败，也可能是DC配置失败，因此配置失败标识信息可以指示配置失败了，同时还可以表示配置失败的具体原因。
MN根据配置失败标识信息确定失败的具体原因，并为UE重新配置SN counter的计数值。
2、UE认为发生SCG配置失败(failure)，并向MN发送失败报告。
可选的，失败报告中携带配置失败标识信息，配置失败的原因可以为SN counter配置失败或DC配置失败，因此配置失败标识信息表示配置失败同时还可以表示配置失败的具体原因。
进一步可选的，该失败报告不包含测量结果，测量结果为该UE服务小区和邻居小区中至少一个小区的信号质量测量结果。
后续MN接收失败报告后，识别失败报告中的配置失败标识信息，根据配置失败标识信息确定失败的具体原因，并为UE重新配置SN counter的计数值。
在步骤1105之后，可选的，MN还可以将重新配置的SN counter的计数值发送给SN。进一步可选的，将配置失败标识信息发送给SN。
在本实施例中，UE通过第一计数值判断第二计数值是否异常，若MN配置了相同的计数值，则UE会发送配置失败标识信息至MN，以避免在不同DC方式下，MN衍生得到了相同的S-key，保证了空口的通信安全。
C、对于协议而言，为保证不同DC方式下，不同的SN使用不同的S-key与UE进行通信，有两种可实现方式：
1、MN通过配置协议，为不同DC方式分配不同的SN counter的计数值取值空间，且每个计数值取值空间不相互重叠。
2、MN通过配置协议，定义多个SN counter的计数值取值空间的起点。
MN为UE配置某一种DC方式时，识别该UE之前是否配置过其他DC方式，若是，则采用取值错开的方式进行配置，例如选取一个新的取值空间的起点。
在本实施例中，上述A、B、C三种方式中的两种或两种以上方式可以结合使用。
请参照图12，对本申请基站的一种可能的结构进行说明。
一种基站120，包括：
接收单元1201，用于接收源基站发送的切换请求，所述切换请求包括第一指示信息，所述第一指示信息用于指示所述源基站的服务质量流qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB；
发送单元1202，用于与向所述源基站发送隧道的信息，所述隧道用于供目标基站接收所述源基站发送的数据单元，所述数据单元为所述qos flow中对应的所述DRB变化为所述第二DRB后的数据单元。
可选的，所述第一指示信息用于指示所述源基站所接收的qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB包括：
所述第一指示信息用于指示所述源基站所接收的来自于用户设备UE的所述qos flow， 从映射至所述第一DRB变化为映射至所述第二DRB，所述qos flow为由于对应的所述DRB变化而缓存在所述源基站的服务数据适配协议SDAP层中的qos flow；
或，所述第一指示信息用于指示所述源基站向所述UE发送的所述qos flow，从映射至所述第一DRB变化为映射至所述第二DRB，所述qos flow为由于对应的所述DRB变化而缓存在所述源基站的SDAP层中的qos flow。
可选的，所述接收单元1201，还用于获取结束指示，所述结束指示用于指示所述UE的SDAP实体停止映射所述qos flow至所述第一DRB；
向所述核心网设备发送所述数据单元。
可选的，所述发送单元1202，还用于在映射到所述第一DRB的所述qos flow被所述UE接收后，通过所述第二DRB向所述UE发送所述数据单元。
可选的，所述隧道的信息包括所述qos flow对应的协议数据单元PDU会话session的标识。
可选的，所述接收单元1201，还用于接收来自所述源基站的第二指示信息，所述第二指示信息用于所述目标基站确定所述数据单元为由于对应的所述DRB变化而缓存在所述源基站的所述SDAP层中的数据单元。
可选的，所述基站还包括：
地址分配单元1203，用于为所述隧道分配地址。
可选的，所述接收单元1201，还用于接收来自所述源基站的序列号状态转移信息，所述序列号状态转移信息包括所述数据单元的SN号。
可选的，所述数据单元的SN号用于所述目标基站确定所述数据单元为由于对应的所述DRB变化而缓存在所述源基站的所述SDAP层中的数据单元。
请参照图13，对本申请基站的另一种可能的结构进行说明。
一种基站130，包括：
发送单元1301，用于发送切换请求至目标基站，所述切换请求包括第一指示信息，所述第一指示信息用于指示所述源基站的服务质量流qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB；
接收单元1302，用于接收所述目标基站发送的隧道的信息；
所述发送单元1301，还用于通过所述隧道发送所述数据单元至所述目标基站，所述数据单元为所述qos flow中对应的所述DRB变化为所述第二DRB后的数据单元。
接下来介绍本申请实施例提供的另一种基站，请参阅图14所示，基站1400包括：
接收器1401、发射器1402、处理器1403和存储器1404(其中基站1400中的处理器1403的数量可以一个或多个，图14中以一个处理器为例)。在本申请的一些实施例中，接收器1401、发射器1402、处理器1403和存储器1404可通过总线或其它方式连接，其中，图14中以通过总线连接为例。
存储器1404可以包括只读存储器和随机存取存储器，并向处理器1403提供指令和数据。存储器1404的一部分还可以包括非易失性随机存取存储器(英文全称：non-volatile random access memory，英文缩写：NVRAM)。存储器1404存储有操作系统和操作指令、 可执行模块或者数据结构，或者它们的子集，或者它们的扩展集，其中，操作指令可包括各种操作指令，用于实现各种操作。操作系统可包括各种系统程序，用于实现各种基础业务以及处理基于硬件的任务。
处理器1403控制网络设备的操作，处理器1403还可以称为中央处理单元(英文全称：central processing unit，英文简称：CPU)。具体的应用中，网络设备的各个组件通过总线系统耦合在一起，其中总线系统除包括数据总线之外，还可以包括电源总线、控制总线和状态信号总线等。但是为了清楚说明起见，在图中将各种总线都称为总线系统。
上述本申请实施例揭示的方法可以应用于处理器1403中，或者由处理器1403实现。处理器1403可以是一种集成电路芯片，具有信号的处理能力。在实现过程中，上述方法的各步骤可以通过处理器1403中的硬件的集成逻辑电路或者软件形式的指令完成。上述的处理器1403可以是通用处理器、数字信号处理器(英文全称：digital signal processing，英文缩写：DSP)、专用集成电路(英文全称：application specific integrated circuit，英文缩写：ASIC)、现场可编程门阵列(英文全称：field-programmable gate array，英文缩写：FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件。可以实现或者执行本申请实施例中的公开的各方法、步骤及逻辑框图。通用处理器可以是微处理器或者该处理器也可以是任何常规的处理器等。结合本申请实施例所公开的方法的步骤可以直接体现为硬件译码处理器执行完成，或者用译码处理器中的硬件及软件模块组合执行完成。软件模块可以位于随机存储器，闪存、只读存储器，可编程只读存储器或者电可擦写可编程存储器、寄存器等本领域成熟的存储介质中。该存储介质位于存储器1404，处理器1403读取存储器1404中的信息，结合其硬件完成上述方法的步骤。
接收器1401可用于接收输入的数字或字符信息，以及产生与网络设备的相关设置以及功能控制有关的信号输入，发射器1402可包括显示屏等显示设备，发射器1402可用于通过外接接口输出数字或字符信息。
本申请实施例中，处理器1403，用于执行前述方法。
另外需说明的是，以上所描述的装置实施例仅仅是示意性的，其中所述作为分离部件说明的模块可以是或者也可以不是物理上分开的，作为模块显示的部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部模块来实现本实施例方案的目的。另外，本申请提供的装置实施例附图中，模块之间的连接关系表示它们之间具有通信连接，具体可以实现为一条或多条通信总线或信号线。
通过以上的实施方式的描述，所属领域的技术人员可以清楚地了解到本申请可借助软件加必需的通用硬件的方式来实现，当然也可以通过专用硬件包括专用集成电路、专用CPU、专用存储器、专用元器件等来实现。一般情况下，凡由计算机程序完成的功能都可以很容易地用相应的硬件来实现，而且，用来实现同一功能的具体硬件结构也可以是多种多样的，例如模拟电路、数字电路或专用电路等。基于这样的理解，本申请的技术方案本质上或者说对现有技术做出贡献的部分可以以软件产品的形式体现出来，该计算机软件产品存储在可读取的存储介质中，如计算机的软盘、U盘、移动硬盘、只读存储器(ROM， Read-Only Memory)、随机存取存储器(RAM，Random Access Memory)、磁碟或者光盘等，包括若干指令用以使得一台计算机设备(可以是个人计算机，服务器，或者网络设备等)执行本申请各个实施例所述的方法。
所述计算机程序产品包括一个或多个计算机指令。在计算机或其中的处理器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申请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储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 (36)

  1. 一种切换的方法，其特征在于，包括：
    目标基站接收源基站发送的切换请求，所述切换请求包括第一指示信息，所述第一指示信息用于指示所述源基站的服务质量流qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB；
    所述目标基站向所述源基站发送隧道的信息，所述隧道用于供所述目标基站接收所述源基站发送的数据单元，所述数据单元为所述qos flow中对应的所述DRB变化为所述第二DRB后的数据单元。
  2. 根据权利要求1所述的方法，其特征在于，所述第一指示信息用于指示所述源基站所接收的qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB包括：
    所述第一指示信息用于指示所述源基站所接收的来自于用户设备UE的所述qos flow，从映射至所述第一DRB变化为映射至所述第二DRB，所述qos flow为由于对应的所述DRB变化而缓存在所述源基站的服务数据适配协议SDAP层中的qos flow；
    或，所述第一指示信息用于指示所述源基站向所述UE发送的所述qos flow，从映射至所述第一DRB变化为映射至所述第二DRB，所述qos flow为由于对应的所述DRB变化而缓存在所述源基站的SDAP层中的qos flow。
  3. 根据权利要求1或2所述的方法，其特征在于，所述方法还包括：
    所述目标基站获取结束指示，所述结束指示用于指示所述UE的SDAP实体停止映射所述qos flow至所述第一DRB；
    所述目标基站向所述核心网设备发送所述数据单元。
  4. 根据权利要求1或2所述的方法，其特征在于，所述方法还包括：
    在映射到所述第一DRB的所述qos flow被所述UE接收后，所述目标基站通过所述第二DRB向所述UE发送所述数据单元。
  5. 根据权利要求1至4中任一项所述的方法，其特征在于，所述隧道的信息包括所述qos flow对应的协议数据单元PDU会话session的标识。
  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：
    所述目标基站接收来自所述源基站的第二指示信息，所述第二指示信息用于所述目标基站确定所述数据单元为由于对应的所述DRB变化而缓存在所述源基站的所述SDAP层中的数据单元。
  7. 根据权利要求1至5中任一项所述的方法，其特征在于，所述目标基站向所述源基站发送隧道的信息之前，所述方法还包括：所述目标基站为所述隧道分配地址。
  8. 根据权利要求1至4中任一项所述的方法，其特征在于，所述目标基站接收源基站发送的切换请求之后，所述方法还包括：
    所述目标基站接收来自所述源基站的序列号状态转移信息，所述序列号状态转移信息包括所述数据单元的包数据汇聚协议服务数据单元PDCP SN号。
  9. 根据权利要求权8所述的方法，其特征在于，所述数据单元的PDCP SN号用于所述目标基站确定所述数据单元为由于对应的所述DRB变化而缓存在所述源基站的所述SDAP层中的数据单元。
  10. 根据权利要求1至5中任一项所述的方法，其特征在于，所述方法还包括：
    所述目标基站接收来自所述源基站的第一映射关系，所述第一映射关系包括所述qos flow与所述第一DRB之间的映射关系；或者，
    所述目标基站接收来自所述源基站的第二映射关系，所述第二映射关系包括所述qos flow与所述第二DRB之间的映射关系。
  11. 一种切换方法，其特征在于，包括：
    源基站发送切换请求至目标基站，所述切换请求包括第一指示信息，所述第一指示信息用于指示所述源基站的服务质量流qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB；
    所述源基站接收所述目标基站发送的隧道的信息；
    所述源基站通过所述隧道发送所述数据单元至所述目标基站，所述数据单元为所述qos flow中对应的所述DRB变化为所述第二DRB后的数据单元。
  12. 根据权利要求11所述的方法，其特征在于，所述第一指示信息用于指示所述源基站所接收的qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB包括：
    所述第一指示信息用于指示所述源基站所接收的来自于用户设备UE的所述qos flow，从映射至所述第一DRB变化为映射至所述第二DRB，所述qos flow为由于对应的所述DRB变化而缓存在所述源基站的服务数据适配协议SDAP层中的qos flow；
    或，所述第一指示信息用于指示所述源基站向所述UE发送的所述qos flow，从映射至所述第一DRB变化为映射至所述第二DRB，所述qos flow为由于对应的所述DRB变化而缓存在所述源基站的SDAP层中的qos flow。
  13. 根据权利要求11或12所述的方法，其特征在于，所述隧道的信息包括所述qos flow对应的协议数据单元PDU会话session的标识。
  14. 根据权利要求13所述的方法，其特征在于，所述源基站接收所述目标基站发送的隧道的信息之后，所述方法还包括：
    所述源基站发送第二指示信息至所述目标基站，所述第二指示信息用于指示所述数据单元为由于对应的所述DRB变化而缓存在所述源基站的所述SDAP层中的数据单元。
  15. 根据权利要求11或12所述的方法，其特征在于，所述源基站接收所述目标基站发送的隧道的信息之后，所述方法还包括：
    所述源基站发送序列号状态转移信息至所述目标基站，所述序列号转移信息包括所述数据单元的包数据汇聚协议服务数据单元PDCP SN号。
  16. 根据权利要求15所述的方法，其特征在于，所述数据单元的PDCP SN号用于所述目标基站确定所述数据单元为由于对应的所述DRB变化而缓存在所述源基站的所述SDAP层中的数据单元。
  17. 一种基站，其特征在于，包括：
    接收单元，用于接收源基站发送的切换请求，所述切换请求包括第一指示信息，所述第一指示信息用于指示所述源基站的服务质量流qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB；
    发送单元，用于与向所述源基站发送隧道的信息，所述隧道用于供目标基站接收所述 源基站发送的数据单元，所述数据单元为所述qos flow中对应的所述DRB变化为所述第二DRB后的数据单元。
  18. 根据权利要求17所述的基站，其特征在于，所述第一指示信息用于指示所述源基站所接收的qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB包括：
    所述第一指示信息用于指示所述源基站所接收的来自于用户设备UE的所述qos flow，从映射至所述第一DRB变化为映射至所述第二DRB，所述qos flow为由于对应的所述DRB变化而缓存在所述源基站的服务数据适配协议SDAP层中的qos flow；
    或，所述第一指示信息用于指示所述源基站向所述UE发送的所述qos flow，从映射至所述第一DRB变化为映射至所述第二DRB，所述qos flow为由于对应的所述DRB变化而缓存在所述源基站的SDAP层中的qos flow。
  19. 根据权利要求17或18所述的基站，其特征在于，所述接收单元，还用于获取结束指示，所述结束指示用于指示所述UE的SDAP实体停止映射所述qos flow至所述第一DRB；
    向所述核心网设备发送所述数据单元。
  20. 根据权利要求17或18所述的基站，其特征在于，所述发送单元，还用于在映射到所述第一DRB的所述qos flow被所述UE接收后，通过所述第二DRB向所述UE发送所述数据单元。
  21. 根据权利要求17至20中任一项所述的基站，其特征在于，所述隧道的信息包括所述qos flow对应的协议数据单元PDU会话session的标识。
  22. 根据权利要求21所述的基站，其特征在于，所述接收单元，还用于接收来自所述源基站的第二指示信息，所述第二指示信息用于所述目标基站确定所述数据单元为由于对应的所述DRB变化而缓存在所述源基站的所述SDAP层中的数据单元。
  23. 根据权利要求17至21中任一项所述的基站，其特征在于，所述基站还包括：
    地址分配单元，用于为所述隧道分配地址。
  24. 根据权利要求17至20中任一项所述的基站，其特征在于，所述接收单元，还用于接收来自所述源基站的序列号状态转移信息，所述序列号状态转移信息包括所述数据单元的包数据汇聚协议服务数据单元PDCP SN号。
  25. 根据权利要求权24所述的基站，其特征在于，所述数据单元的PDCP SN号用于所述目标基站确定所述数据单元为由于对应的所述DRB变化而缓存在所述源基站的所述SDAP层中的数据单元。
  26. 根据权利要求17至21中任一项所述的基站，其特征在于，
    所述发送单元，还用于接收来自所述源基站的第一映射关系，所述第一映射关系包括所述qos flow与所述第一DRB之间的映射关系；或者，
    所述发送单元，还用于接收来自所述源基站的第二映射关系，所述第二映射关系包括所述qos flow与所述第二DRB之间的映射关系。
  27. 一种基站，其特征在于，包括：
    发送单元，用于发送切换请求至目标基站，所述切换请求包括第一指示信息，所述第一指示信息用于指示所述源基站的服务质量流qos flow对应的无线数据承载DRB从第一 DRB变化为第二DRB；
    接收单元，用于接收所述目标基站发送的隧道的信息；
    所述发送单元，还用于通过所述隧道发送所述数据单元至所述目标基站，所述数据单元为所述qos flow中对应的所述DRB变化为所述第二DRB后的数据单元。
  28. 根据权利要求27所述的基站，其特征在于，所述第一指示信息用于指示所述源基站所接收的qos flow对应的无线数据承载DRB从第一DRB变化为第二DRB包括：
    所述第一指示信息用于指示所述源基站所接收的来自于用户设备UE的所述qos flow，从映射至所述第一DRB变化为映射至所述第二DRB，所述qos flow为由于对应的所述DRB变化而缓存在所述源基站的服务数据适配协议SDAP层中的qos flow；
    或，所述第一指示信息用于指示所述源基站向所述UE发送的所述qos flow，从映射至所述第一DRB变化为映射至所述第二DRB，所述qos flow为由于对应的所述DRB变化而缓存在所述源基站的SDAP层中的qos flow。
  29. 根据权利要求27或28所述的基站，其特征在于，所述隧道的信息包括所述qos flow对应的协议数据单元PDU会话session的标识。
  30. 根据权利要求29所述的基站，其特征在于，所述发送单元，还用于发送第二指示信息至所述目标基站，所述第二指示信息用于指示所述数据单元为由于对应的所述DRB变化而缓存在所述源基站的所述SDAP层中的数据单元。
  31. 根据权利要求27或28所述的基站，其特征在于，所述发送单元，还用于发送序列号状态转移信息至所述目标基站，所述序列号转移信息包括所述数据单元的包数据汇聚协议服务数据单元PDCP SN号。
  32. 根据权利要求31所述的基站，其特征在于，所述数据单元的PDCP SN号用于所述目标基站确定所述数据单元为由于对应的所述DRB变化而缓存在所述源基站的所述SDAP层中的数据单元。
  33. 一种基站，其特征在于，包括：存储器、收发器以及处理器；
    其中，所述存储器用于存储程序和指令；
    所述收发器用于在所述处理器的控制下接收或发送信息；
    所述处理器用于执行所述存储器中的程序；其中，所述处理器用于调用所述存储器中的程序指令，执行如权利要求1至16中任一项所述的方法。
  34. 根据权利要求33所述的基站，其特征在于，所述基站还包括总线系统；
    所述总线系统用于连接所述存储器、所述收发器以及所述处理器，以使所述存储器、所述收发器以及所述处理器进行通信。
  35. 一种计算机可读存储介质，包括指令，当所述指令在计算机上运行时，使得计算机执行如权利要求1至16中任意一项所述的方法。
  36. 一种包含指令的计算机程序产品，当其在计算机上运行时，使得计算机执行如权利要求1至16中任意一项所述的方法。
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