WO2023109634A1 - Cell handover method and apparatus, storage medium, user equipment, and network equipment - Google Patents

Abstract

A cell handover method and apparatus, a storage medium, user equipment, and network equipment. The cell handover method comprises: in a dual active protocol stack (DAPS) handover process, receiving first high-layer signaling, the first high-layer signaling instructing the release of at least one source serving cell, multiple source serving cells providing service using carrier aggregation or dual connectivity, and the at least one source serving cell being some or all of the multiple source serving cells; releasing a connection with the at least one source serving cell. By means of a technical solution of the present invention, a source cell can be properly released during DAPS handover in a carrier aggregation scenario, so as to reduce the carrier load and save the power overhead.

Description

Cell handover method and device, storage medium, terminal equipment, network equipment

This application claims the priority of the Chinese patent application submitted to the China Patent Office on December 13, 2021, with the application number 202111518522.7, and the title of the invention is "cell handover method and device, storage medium, terminal equipment, network equipment", the entire content of which is passed References are incorporated in this application.

technical field

The present invention relates to the field of communication technology, in particular to a cell switching method and device, storage medium, terminal equipment, and network equipment.

Background technique

In the traditional handover process, there will always be a long user plane interruption time, because once the terminal equipment (User Equipment, UE) receives the handover command, the terminal equipment will interrupt the communication with the source base station, and instead synchronize to the target cell and Execute the random access process. After the random access is successful, the terminal device can continue to perform data transmission with the target base station, and there is a certain interruption time in the middle. In order to achieve a switching delay of 0ms, a dual active protocol stack (Dual Active Protocol Stack, DAPS) switching is introduced in wireless communication. The newly introduced DAPS handover requires that the terminal equipment maintain communication with the source base station and the target base station at the same time during the handover process. During the handover process, the terminal device releases the connection with the source base station after it has started normal communication with the target cell.

In the current system, DAPS handover is only applicable to non-carrier aggregation scenarios, that is, the source cell is a serving cell, also called the source primary cell (PCell). The target cell is also a serving cell (also called the target PCell). At this time, after the terminal device successfully performs random access on the target side, it performs uplink data conversion ( UpLink Data Switch). After a period of time, the target cell instructs the terminal device to release the link on the source side through the radio resource control (Radio Resource Control, RRC) reconfiguration signaling. After receiving the signaling, the terminal device releases the link on the source side. Maintain communication with the target side.

However, in the new protocol version, DAPS handover can be applied to carrier aggregation scenarios. For example, the source side and the target side can be multiple serving cells. How to release the source cell is an urgent problem to be solved.

Contents of the invention

The present invention provides a cell switching method and device, a storage medium, a terminal device, and a network device, capable of reasonably releasing a source cell in DASP switching in a carrier aggregation scenario, so as to reduce carrier load and save power consumption.

In order to solve the above-mentioned technical problems, in the first aspect, an embodiment of the present invention provides a cell handover method, the cell handover method includes: receiving a first high-level signaling during a dual-active stack DAPS handover process, the first high-level signaling indicating Release at least one source serving cell, multiple source serving cells provide services using carrier aggregation or dual connectivity, the at least one source serving cell is part or all of the multiple source serving cells; A connection to a source serving cell.

Optionally, the at least one source serving cell is part of the multiple source serving cells, and the method further includes: receiving a second high-layer signaling, the second high-layer signaling instructing to release the Other source serving cells in the plurality of source serving cells except the at least one source serving cell; release the connection with the other source serving cells.

Optionally, before receiving the first high-level signaling, it includes: performing uplink data conversion on at least one data radio bearer configured as dual-activation stack DAPS switching, and the at least one source serving cell transmits the data in the at least one data radio bearer part or all of .

Optionally, the number of the target serving cell is one, and performing uplink data conversion on at least one data radio bearer configured as dual active stack DAPS handover includes: simultaneously performing the uplink data conversion on the at least one data radio bearer configured as dual active stack DAPS handover The bearer performs upstream data conversion.

Optionally, multiple target serving cells are configured in the handover command, the target serving cells include a target primary cell and a target secondary cell, and before receiving the first high-layer signaling includes: accessing the target primary cell, the target The secondary cell is in an inactive state or a dormant state; performing uplink data conversion on the first data radio bearer transmitted by the target primary cell.

Optionally, before receiving the second high-layer signaling, the method further includes: accessing the target secondary cell; performing uplink data conversion on the second data radio bearer transmitted by the target secondary cell.

Optionally, the cell switching method further includes: sending uplink signaling, where the uplink signaling carries a notification message, and the notification message indicates that the connection with the at least one source serving cell has been released.

In the second aspect, an embodiment of the present invention provides a cell switching method, the cell switching method includes: during the dual-activation stack DAPS switching process, configuring a first high-level signaling, the first high-level signaling indicates the release of at least one source serving cell A plurality of source serving cells provide services by using carrier aggregation or dual connectivity, the at least one source serving cell is part or all of the plurality of source serving cells; sending the first high-level signaling.

Optionally, the configuring the first high-layer signaling includes: configuring the first high-layer signaling at least when all downlink data of the data radio bearers transmitted by the at least one source serving cell are transmitted by the target serving cell.

Optionally, before configuring the first high-level signaling, the method further includes: judging whether the downlink data of the data radio bearer is transmitted by the target serving cell through a PDCP status report.

Optionally, at least when the downlink data of the data radio bearer is transmitted by the target serving cell, configuring the first high-level signaling includes: all the downlink data of the data radio bearer is transmitted by the target serving cell, And when the uplink data of the data radio bearer does not need to be transmitted by the at least one source serving cell, the first high-level signaling is configured.

Optionally, before configuring the first high-layer signaling, it also includes: determining the start sequence number of the data packet received when the uplink number is converted; according to the sequence number of the received uplink data packet and the start sequence number Judging whether the uplink data packets whose sequence numbers are located before the starting sequence number are all received successfully; if the uplink data packets whose sequence numbers are located before the starting sequence number are all successfully received, it is determined that the uplink data of the data radio bearer does not need The at least one source serving cell transmits.

In the third aspect, the embodiment of the present invention is a cell handover device. The cell handover device includes: during the dual-active stack DAPS handover process, a receiving module, configured to receive a first high-level signaling, and the first high-level signaling indicates to release at least One source serving cell, multiple source serving cells provide services using carrier aggregation or dual connectivity, the at least one source serving cell is part or all of the multiple source serving cells; the processing module is used to release and A connection of the at least one source serving cell.

The fourth invention, the embodiment of the present invention provides a cell handover device, the cell handover device includes: a configuration module, configured to configure the first high-level signaling during the dual-active stack DAPS switching process, and the first high-level signaling indicates release At least one source serving cell, multiple source serving cells provide services using carrier aggregation or dual connectivity, the at least one source serving cell is part or all of the multiple source serving cells; a sending module, configured to send The first high-layer signaling.

In a fifth aspect, an embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the cell handover method are executed.

In a sixth aspect, an embodiment of the present invention provides a terminal device, including a memory and a processor, the memory stores a computer program that can run on the processor, and the processor executes the computer program when running the computer program. Steps of the cell handover method described above.

In a seventh aspect, an embodiment of the present invention provides a network device, including a memory and a processor, the memory stores a computer program that can run on the processor, and the processor executes the computer program when running the computer program. Steps of the cell handover method described above.

Compared with the prior art, the technical solutions of the embodiments of the present invention have the following beneficial effects:

In the technical solution of the present invention, the network device can instruct the terminal device to release at least one source serving cell through high-level signaling, and the terminal device can receive and release the connection with the at least one source serving cell according to the first high-level signaling. The technical solution of the present invention can reasonably release part of the source cells, thereby realizing timely release of source serving cells that do not need to be used during DAPS switching, on the one hand, it can reduce carrier load, reduce processing complexity, and save power overhead; on the other hand The processing capability of the terminal device can be released in time, so that the target network device can more flexibly schedule the terminal device.

Further, in the technical solution of the present invention, the network device may instruct the terminal device to release the corresponding source cell when the downlink data carried by the data radio bearer is all transmitted by the target serving cell; or when the downlink data carried by the data radio bearer is all transmitted by the target serving cell, And when the uplink data of the data radio bearer does not need to be transmitted by the at least one source serving cell, instruct the terminal device to release the corresponding source cell, so as to realize the reasonable handling of the release of the source cell.

Description of drawings

FIG. 1 is a flow chart of a cell handover method according to an embodiment of the present invention;

FIG. 2 is a specific flow chart of a cell handover method according to an embodiment of the present invention;

FIG. 3 is a specific flowchart of another cell handover method according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a cell handover device according to an embodiment of the present invention;

Fig. 5 is a schematic structural diagram of another cell switching device according to an embodiment of the present invention.

Detailed ways

The communication systems to which the embodiments of the present application are applicable include, but are not limited to, long term evolution (long term evolution, LTE) systems, fifth generation (5th-generation, 5G) systems, NR systems, and future evolution systems or multiple communication fusion systems. Wherein, the 5G system may be a non-standalone (NSA) 5G system or a standalone (standalone, SA) 5G system. The technical solution of the present application is also applicable to different network architectures, including but not limited to relay network architecture, dual-link architecture, Vehicle-to-Everything (vehicle-to-everything communication) architecture and other architectures.

This application mainly relates to communication between terminal equipment and network equipment. in:

The network device in the embodiment of the present application may also be called an access network device, for example, it may be a base station (base station, BS) (also called a base station device), and the network device is a type of network device deployed on a wireless access network (Radio Access Network, RAN) is a device used to provide wireless communication functions. For example, equipment that provides base station functions in the second-generation (2nd-generation, 2G) network includes base transceiver stations (BTS), and equipment that provides base station functions in the third-generation (3rd-generation, 3G) network includes Node B (NodeB), the equipment that provides base station functions in the fourth-generation (4th-generation, 4G) network includes evolved Node B (evolved NodeB, eNB), in wireless local area networks (wireless local area networks, WLAN), The device that provides base station functions is the access point (access point, AP), the device that provides base station functions in NR, the next generation base station node (next generation node base station, gNB), and the node B (ng-eNB) that continues to evolve, Among them, gNB and terminal devices use NR technology for communication, and ng-eNB and terminal devices use Evolved Universal Terrestrial Radio Access (E-UTRA) technology for communication. Both gNB and ng-eNB Can be connected to 5G core network. The network equipment in this embodiment of the present application also includes equipment that provides base station functions in future new communication systems, and the like.

The terminal equipment (terminal equipment) in the embodiment of the present application may refer to various forms of access terminals, subscriber units, subscriber stations, mobile stations, mobile stations (mobile station, MS), remote stations, remote terminals, mobile equipment, user Terminal, wireless communication device, user agent or user device. The terminal equipment can also be a cellular phone, a cordless phone, a Session Initiation Protocol (Session Initiation Protocol, SIP) phone, a wireless local loop (Wireless Local Loop, WLL) station, a personal digital processing (Personal Digital Assistant, PDA), a wireless communication Functional handheld devices, computing devices or other processing devices connected to wireless modems, vehicle-mounted devices, wearable devices, terminal devices in the future 5G network or future evolution of the public land mobile network (Public Land Mobile Network, PLMN) The terminal device and the like are not limited in this embodiment of the present application. A terminal device may also be called a user equipment (User Equipment, UE), a terminal, and the like.

As mentioned in the background, in the new protocol version, DAPS handover can be applied to the carrier aggregation scenario. For example, the source side and the target side can be multiple serving cells. How to release the source cell is an urgent problem to be solved.

In the technical solution of the present invention, the network device can instruct the terminal device to release at least one source serving cell through high-level signaling, and the terminal device can receive and release the connection with the at least one source serving cell according to the first high-level signaling. The technical solution of the present invention can realize the release of part of the source cells, so as to realize the timely release of the serving cells that do not need to be used during DAPS switching, on the one hand, it can reduce the carrier load, reduce the processing complexity, and save power consumption; on the other hand, it can release in time The processing capability of the terminal device can facilitate the target network device to more flexibly schedule the terminal device.

In order to make the above objects, features and advantages of the present invention more comprehensible, specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

FIG. 1 is a flow chart of a cell handover method according to an embodiment of the present invention;

The cell handover method shown in FIG. 1 can be used in terminal-side equipment; that is, the various steps of the cell handover method can be performed by the terminal equipment, or can be performed by a chip in the terminal equipment.

Specifically, the cell handover method may include the following steps:

Step 101: The terminal device receives a first high-level signaling during the DAPS handover process of dual active stacks, the first high-level signaling indicates the release of at least one source serving cell, and multiple source serving cells provide services using carrier aggregation or dual connectivity;

Step 102: The terminal device releases the connection with at least one source serving cell.

Correspondingly, please also refer to FIG. 2 , before step 101 , the target network device may execute step 201 and step 202 .

In step 201, the target network device configures first high-level signaling.

In step 202, the target network device sends a first layer signaling to the terminal device.

It can be understood that, in a specific implementation, the cell handover method may be implemented in the form of a software program, and the software program runs in a processor integrated in a chip or a chip module. The method may also be implemented by combining software with hardware, which is not limited in this application.

In the embodiment of the present invention, the source network device refers to the network device that provides services for the terminal device before the cell handover, and the target network device refers to the network device that provides services for the terminal device after the cell handover.

In specific implementation, the high-level signaling can be radio resource control (Radio Resource Control, RRC) signaling, or non-access stratum signaling, or media access control (Media Access Control, MAC) control element (Control Element , CE), or any other practicable signaling, which is not limited in this embodiment of the present invention.

In this embodiment, multiple source serving cells of the source network device provide services for the terminal device in a manner of carrier aggregation or dual connectivity. The first high-level signaling may indicate to release a source serving cell. In this case, the terminal device releases the connection with the above-mentioned one source serving cell, and continues to maintain the connection with other source serving cells of the source network device. The first high-layer signaling may also indicate to release all source serving cells. In this case, the terminal device releases connections with all source serving cells, and the terminal device only maintains connection with the target serving cell of the target network device.

It should be noted that when the number of source serving cells is 2, the first high-level signaling may indicate the release of one source serving cell or two source serving cells; when the number of source serving cells is 3, the first high-level signaling may indicate the release of One source serving cell, 2 source serving cells, or 3 source serving cells, the case where the number of source serving cells is other values can be deduced by analogy, and will not be repeated here.

In this embodiment, in the carrier aggregation scenario, such as the carrier aggregation scenario on the source network device side, if different cells undertake different service transmission tasks, when some services have completed uplink data conversion, the source serving cell carrying this service can release , so as to reduce the processing complexity of the terminal device, improve the degree of freedom of scheduling on the target side, and reduce the power consumption of the terminal device.

In a non-limiting embodiment of the present invention, the at least one source serving cell indicated in the first high-level signaling is a part of the source serving cells in the multiple source serving cells of the source network device. In this case, the target network device may instruct step 203 to send the second layer signaling to the terminal device. The second high-level signaling indicates to release other source serving cells in the plurality of source serving cells except the at least one source serving cell. When the number of source serving cells is N, N is a positive integer greater than or equal to 2, and N source serving cells can be respectively released through N signaling at most. For example, if there are more than 2 serving cells on the source side, if there are 3 serving cells, the 3 source serving cells can be released respectively through three release signalings at most.

In step 204, the terminal device releases connections with other source serving cells.

In this embodiment, after step 102 is performed, the terminal device remains connected to other source serving cells. After step 204 is executed, the terminal device disconnects from other source serving cells, and only maintains connection with the target cell of the target network device.

In a non-limiting embodiment of the present invention, before step 101, the terminal device performs uplink data conversion on at least one data radio bearer configured as dual active stack DAPS switching. It can also be said that the terminal device performs uplink data conversion on the data radio bearer transmitted by the at least one source serving cell, and the data radio bearer configuration performs DAPS handover. It should be noted that, in the protocol, handover is sometimes referred to as synchronous reconfiguration, so DAPS handover may also be referred to as DAPS synchronous reconfiguration.

In a specific implementation, after accessing the target serving cell of the target network device, the terminal device determines the data radio bearer that can be transmitted by the target serving cell (it is also the data radio bearer transmitted by at least one source serving cell), and transmits the data wireless bearer The bearer performs upstream data conversion. That is to say, the packet data convergence layer protocol (Packet Data Convergence Protocol, PDCP) entity of the data radio bearer needs to perform one of the following operations: The radio link control (Radio Link Control, RLC) confirms the successful transmission of the PDCP service data unit (Service Data Unit, SDU), which is handed over to the RLC entity of the target network device for transmission or retransmission. For the data radio bearer (UM DRB) in unacknowledged mode, the PDCP SDU that has not been delivered to the underlying layer for transmission is delivered to the RLC entity of the target network device for transmission. The PDCP entity of the terminal device needs to adopt the encryption and integrity protection algorithm of the target network device.

In a non-limiting embodiment of the present invention, when the target network device configures the first high-layer signaling, it has judged that the downlink data of a data radio bearer configured for DAPS handover has been transmitted on the source side, and the data radio bearer The other data packets have been forwarded to the target side, and will be sent to the terminal device by the target side; from the perspective of the terminal device, when the downlink data of a data radio bearer configured for DAPS handover is transmitted by the target serving cell, the network side can configure all The above-mentioned first high-layer signaling is used so that the terminal device can release the source serving cell that can originally transmit the data radio bearer data at the source side.

In this embodiment, after the terminal device completes the uplink data conversion for the data radio bearer, the target network device may configure the first layer signaling to notify the terminal device to release the above source serving cell.

Further, the target network device may judge whether the downlink data of the data radio bearer is transmitted by the target serving cell through the PDCP status report. The PDCP status report is reported by the terminal device to the target network device. The PDCP status report includes the receiving status of the data packet (such as successful or failed reception). The target network device can combine the status of the data packet cached by itself and the received PDCP status report. It is judged whether the downlink data of the data radio bearer has been transmitted on the source side, and all new data packets will be sent to the terminal device by the target side.

Further, the target network device may also configure the first high-level signaling when confirming that the downlink data and uplink data of the data radio bearer no longer need to be transmitted through the source serving cell that transmits the data radio bearer.

In a specific implementation, the target network device can determine that the uplink data no longer needs to be transmitted through the source serving cell that transmits the data radio bearer: determine the starting sequence number of the data packet that starts to be received when the uplink number is converted; The sequence number of the uplink data packet and the start sequence number determine whether the uplink data packets whose sequence numbers are located before the start sequence number are all received successfully; if the uplink data packets whose sequence numbers are located before the start sequence number are all If the reception is successful, it is determined that the uplink data of the data radio bearer does not need to be transmitted by the at least one source serving cell.

For example, for DRB1, when the terminal device performs uplink data conversion, the data packet with sequence number 100 (that is, the starting sequence number) is handed over to the RLC entity associated with the target network device for transmission. The target network device can know the serial numbers of the data packets it receives. If the target network device finds that all data packets with serial numbers before 100 have been successfully received, it means that the terminal device has no data packets that need to be transmitted by the source network device. up. The target network device may instruct the terminal device to release the source serving cell for transmitting DRB1.

It should be noted that the process of configuring the second layer signaling on the target network device is in the same principle as the process of configuring the first layer signaling, and will not be repeated here.

Hereinafter, a specific embodiment is used to illustrate the above-mentioned process of cell handover. In the following embodiments, the source network device is the source base station, and the target network device is the target base station.

The terminal equipment establishes 3 data radio bearers, DRB1, DRB2 and DRB3, among which DRB1 and DRB2 have higher requirements for quality of service parameters and require a shorter data transmission delay, so the serving base station (the source base station before the handover) prepares for DRB1 and DRB2 DRB2 is configured with DAPS switching, while DRB3 is not configured with DAPS switching. At this time, the source base station configures Cell1 (primary cell) and Cell2 (secondary cell) as serving cells of the terminal device for the UE. The source base station learns from the capability parameter of the terminal device that the terminal device supports DAPS switching of carrier aggregation.

After receiving the measurement report sent by the terminal device, the source base station finds that the terminal device is already at the edge of the cell. In order to meet the mobility, the source base station selects the cell under the jurisdiction of the target base station such as Cell3/Cell4 as the terminal according to the measurement report reported by the terminal device. The target cell for device handover.

Referring to FIG. 3, in step 301, the source base station may send a handover request to the target base station. Specifically, when the source base station sends a handover request to the target base station, it indicates in the handover request that DRB1 and DRB2 request configuration as DAPS handover, and the handover request also includes other wireless parameters configured by the source base station for the terminal device. For the target base station, it can decide whether to accept the handover request based on its own load level, and if accepted, configure necessary wireless resources for the terminal equipment.

In step 302, the target base station returns a handover request confirmation to the source base station. Handover request confirmation can be called Handover Request Acknowledge, or Handover Preparation Acknowledge. If the target base station does not accept the handover request, it returns request failure to the source base station.

In the case of accepting the handover request, the target base station can configure wireless resources for DAPS handover, the target base station can configure DRB1 and DRB2 for DAPS handover, and additionally configure DAPS-related parameters for terminal equipment, such as configuring uplink power during DAPS handover The mode of sharing (uplinkPowerSharingDAPS-Mode). The configured wireless parameters are usually placed in a transparent container (Target NG-RAN node To Source NG-RAN node Transparent Container). The source base station does not need to parse the content in this container, and sends it directly to the terminal device.

In a specific embodiment, the target base station decides to configure carrier aggregation for the terminal device based on the coverage of the cell under its jurisdiction and the load level of the cell, and decides to configure Cell3 and Cell4 as serving cells on the target side of the handover of the terminal device (that is, target serving cell), where Cell3 is the target Pcell, and Cell4 is the secondary cell (Secondary cell, SCell). The target base station can also configure DRB1 to be limited to data transmission through PCell, and DRB2 to be limited to data transmission through SCell. The configured serving cell parameters and the mapping relationship between DRB and serving cell are all wireless parameters and are located in the transparent container.

Wherein, the mapping relationship between the data radio bearer and the target serving cell may be directly configured by the target base station. Specifically, the target base station can directly configure DRB1 to only have a mapping relationship with the PCell on the target base station side, that is, DRB1 can only transmit data through PCell; or the target base station can configure data transmission restrictions for DRB2, and then the terminal device The condition determines the mapping relationship between DRB2 and the target serving cell. For example, the target base station configures DRB2 to only transmit through the sub-carrier space (SCS) of 30kHz, and different target serving cells can correspond to different sub-carrier spaces. At this time, the terminal device can judge whether DRB2 can pass Pcell transmission or whether it can be transmitted through SCell, if Pcell adopts 15kHz subcarrier spacing, and SCell adopts 30kHz subcarrier spacing, then the terminal device can only transmit DRB2 through SCell. If the network side has no restrictions on the transmission of the DRB configuration, the DRB can be transmitted through any serving cell.

In this embodiment, the source base station may also configure a transmission mapping relationship for each data radio bearer, that is, DRB1 transmits through the source-side primary cell (that is, Cell1), and DRB2 transmits through the source-side secondary cell (that is, Cell2).

After the source base station receives the handover request confirmation returned by the target base station, in step 303, the source base station sends a handover command to the terminal device. The handover command may be carried by RRC signaling.

In step 304, the terminal device may implement DAPS handover. Specifically, the terminal device adopts DAPS handover for DRB1, and the terminal device reconfigures the PDCP entity of DRB1 as a PDCP entity for DAPS handover. At this time, the PDCP entity can process data from the source base station and the target base station at the same time. The same process is applied to DRB2.

The terminal device initiates random access according to the random access resources of the target serving cell configured in the handover command. When accessing Cell3, continue to maintain the connection with the source serving cell. Specifically, the terminal device can perform random access in the following three ways:

Mode 1, a four-step contention random access process. The terminal device sends a random access preamble to the target PCell (that is, Cell3), then receives a random access response, sends a message 3 (MSG3) according to the uplink transmission resources indicated in the random access response, and then receives a message 4 (MSG4). If the correct MSG4 is received, it is considered that the random access is successful.

Mode 2, a two-step random access process. The terminal device sends the random access preamble and the handover completion signaling on the uplink shared channel to the target PCell (that is, Cell3), and then receives the random access response, and receiving the message B (MSGB) indicates that the conflict resolution also means random access entered successfully.

Mode 3, a non-contention random access process. The terminal device sends the random access preamble specified in the handover command by the target base station, and once the terminal device receives the random access response sent by the base station to schedule itself, it considers the random access to be successful.

The terminal device usually performs a random access, as long as the terminal device receives the correct MSG4, MSGB or receives a random access response in the non-contention random access process, it is considered that the random access is successful.

After the terminal device successfully randomly accesses PCell, because DRB1 can perform data transmission through PCell, the terminal device executes the UL Data Switch of the DRB, that is, if the DRB is AM (acknowledged mode), the first one that has not been confirmed by RLC The successfully transmitted PDCP SDU starts and is handed over to the RLC entity on the (associated) target side for transmission or retransmission. If the DRB is UM (unacknowledged mode), for the PDCP SDUs that have not been delivered to the bottom layer for transmission, they are delivered to the RLC entity on the (associated) target side for transmission.

At this time, for DRB2, because the network configures the DRB2 to transmit only through the SCell (that is, cell4), the UL Data Switch of the terminal device for the DRB depends on whether the SCell is available. Usually, the target base station can configure the activation status of the SCell in the handover command, for example, after the terminal device is configured to access the target cell, the SCell is inactive, active, or in a dormant state (Dormancy). If the target base station is not explicitly indicated, it is inactive by default.

In this embodiment, after the terminal device discovers the access target PCell, the configuration of the SCell is inactive, and the terminal device cannot perform UL Data Switch on DRB2. At this time, the terminal device maintains connection with Cell1 and Cell2 on the source side, and maintains connection with Cell3 on the target side. DRB1 has implemented UL Data Switch, and DRB2 has not yet implemented UL Data Switch.

In step 305, the target base station may notify the terminal device to activate the SCell (ie cell4) at this time. The command to activate the Scell requires a certain processing delay, and if the SCell and PCell belong to different Timing Advance Groups (Timing Advance Group), the target base station needs to trigger the terminal device to perform random access on the Scell, and the terminal device receives the random access response Only after that can the uplink timing advance TA of the SCell be obtained. At this time, the terminal device performs data transmission with Cell1, Cell2, and Cell3 at the same time, and the terminal device has already started to transmit the data of DRB1 on the target side.

When the target base station finds that the uplink and downlink data of DRB1 no longer needs to be transmitted through Cell1, in step 306, the target base station sends RRC signaling to the terminal equipment to instruct to release the Cell1 at the source side. In this way, the terminal device can reduce the load of one carrier, reduce processing complexity, and save power consumption. At the same time, because during the DAPS handover process, the source base station and the target base station will not negotiate the capacity allocation of the terminal device in a very specific way, so the target base station will not use the processing capacity of the terminal device during the DAPS handover process of the terminal device. Once the terminal device Being able to release some cells on the source side, such as Cell1, can release a large part of the processing capability of the terminal equipment, and facilitate the target base station to more flexibly schedule the terminal equipment. After releasing Cell1, the terminal device continues to maintain the connection with Cell2. Specifically, for downlink data, the target base station can determine that all downlink data packets are sent from the local side to the terminal device in combination with the PDCP status report reported by the terminal device, and the downlink data packets originally sent on the source side have successfully arrived at the terminal device, then The target base station may send RRC signaling to indicate to release Cell1. For uplink data, the target base station can determine from the sequence number of the uplink data packet received by the local side that the terminal device has no data packets that need to be transmitted further via the source side, and then the target base station can send RRC signaling to indicate the release of Cell1.

In step 307, the terminal device may notify the source base station that the configuration of Cell1 has been released through uplink signaling.

After the terminal device has processed the activation command of Cell4 (the command has taken effect), or when it needs to obtain the uplink TA of Cell4 through random access, the terminal device executes the UL Data Switch of DRB2, and the terminal device regards the data that DRB2 has not successfully transmitted on the source side Packets are transmitted through Cell4. The terminal device continues to perform uplink and downlink data transmission through Cell2, mainly some unsuccessfully transmitted data of DRB2, that is, the uplink data in the Layer 2 buffer (Layer 2 Buffer) of the terminal device. The terminal device may also try to perform uplink transmission through Cell2.

After a period of time, when the target base station finds that the uplink and downlink data of DRB2 no longer needs to be transmitted through the source-side Cell2, in step 308, the target base station can notify the terminal device to release the source-side Cell2 through RRC signaling.

After receiving the command to release Cell2, the terminal device releases all configurations on the source side, interrupts communication with the source side, and only communicates with the target base station.

In another specific embodiment of the present invention, different from the foregoing embodiments, the source base station may use carrier aggregation or dual connectivity to provide services for terminal devices. For example, the source serving cells are Cell1 and Cell2, while the target base station is in a non-carrier aggregation scenario, for example, the serving cell of the target base station is only Cell3. DRB1 and DRB2 are configured with DAPS switching. On the source base station side, DRB1 can only transmit through Cell1, and DRB2 can only transmit through Cell2.

In this embodiment, the terminal device simultaneously performs uplink data conversion on data radio bearers transmitted by all source serving cells.

When the terminal device performs DAPS handover and successfully performs random access on the target side, the terminal device can simultaneously perform uplink data conversion on multiple DRBs configured with DAPS handover, such as DRB1 and DRB2. Although DRB1 and DRB2 execute UL Data Switch at the same time, the transmission rates of DRB1 and DRB2 may be quite different. For example, for DRB1, there is almost no data to be transmitted on the source side, and DRB2 has more data to be transmitted on the source side. . The target base station judges the uplink and downlink transmission status of different DRBs based on its own transmission status. DRB1 has no uplink and downlink data to be transmitted on the source side, and DRB2 still has some uplink and downlink data to be transmitted on the source side. Therefore, the target base station can In the first time, the terminal device is notified to release the Cell1 on the source side through RRC signaling (that is, the first high-layer signaling). After a period of time, when the target base station judges that DRB2 has no data to transmit on the source side, it notifies the terminal equipment to release Cell2 through RRC signaling (that is, the second high-layer signaling).

It should be noted that, in the embodiment of the present invention, the number of secondary cells for which the source base station uses carrier aggregation is 1, that is, there is only one secondary cell. In an actual application scenario, the number of secondary cells may also be multiple, for example, 2, 3, etc., which is not limited in this embodiment of the present invention.

It can be understood that, the RRC signaling in the foregoing embodiments can also be replaced with other high-level signaling, such as non-access stratum signaling or MAC CE, which is not limited in the embodiment of the present invention.

In a non-limiting embodiment, during the DAPS handover process, for the data radio bearer DRB that applies DAPS handover, when transmitting downlink data, the source base station needs to uniformly allocate PDCP sequence numbers for PDCP data packets, and then transfer some data packets to And the corresponding sequence number is sent to the target base station, and then the target base station sends the downlink data to the terminal device during the handover process, and the downlink data sent by the target base station adopts the security algorithm and header compression algorithm of the target side. The source base station performs source-side header compression and security algorithms on another part of the data packets, and then sends the source base station to the terminal device. The terminal device receives the data packets sent by both sides, performs unified sorting, uses different decompression (Decompression) and decoding (Deciphering) algorithms according to different receiving sources, and then sends them to the upper layer in sequence. For the DRB, a corresponding PDCP entity needs to execute an independent security algorithm and an independent header compression algorithm on both the source base station side and the target base station side. For the terminal device, it is necessary to receive the data packets sent by the source base station and the target base station at the same time. The terminal device applies the corresponding security algorithm according to the different data sources, and executes the corresponding header compression algorithm, and uses the public sorting function to obtain a complete and effective sequenced packets.

For a DRB that applies DAPS switching, when transmitting uplink data during the switching process, the terminal device uniformly assigns PDCP sequence numbers to data packets, some data packets are sent to the source base station through the source link, and some data packets are sent to the target through the new link base station. Depending on the object to be sent, the terminal device uses different security algorithms and header compression algorithms for data packets. For example, for data packets sent through the source link, it needs to be processed according to the security algorithm and header compression algorithm of the source base station side; for The data packets sent through the new link need to be processed according to the security algorithm and header compression algorithm on the target base station side.

For the DRB applying DAPS handover, there is only one PDCP entity in the handover process. During the handover process, the PDCP entity needs to process two sets of security algorithms and two sets of header compression algorithms. Configuring DAPS switching can be applied to scenarios where keys are updated (reconfiguration with sync for DAPS and security key refresh), and can also be applied to scenarios that do not require key updates (reconfiguration with sync for DAPS but without security key refresh). In the key update scenario, for the PDCP entity of the DAPS DRB, it is also necessary to establish encryption and integrity protection functions on the target side.

In another specific embodiment of the present invention, the UE has three serving cells such as Cell1, Cell2, and Cell3 on the source side, and the three DRBs established by the UE are mapped to these three serving cells, such as DRB1 is mapped to Cell1, that is, through Cell1 transmits DRB1; DRB2 is mapped to Cell2, and DRB3 is mapped to Cell3. During the DAPS handover process, DRB1 and DRB2 are configured for DAPS handover, and DRB3 is not configured for DAPS handover. After receiving the handover command, the UE finds that Cell3 on the source side does not serve the DRBs configured for DAPS handover, that is, DRB1 and DRB2. Therefore, the UE After receiving the switching command, Cell3 is automatically released. In this way, the power consumption and processing complexity of the UE can be reduced. For Cell1 and Cell2, the network can follow the above method to release Cell1 and Cell2 in sequence to realize smooth DAPS handover. That is to say, the terminal device releases the first source serving cell in response to receiving the handover command, the first source serving cell is not configured to transmit the first data radio bearer, and the first data radio bearer is configured as data for dual active stack DAPS handover wireless bearer. The above steps are executed before step 101 shown in FIG. 1 .

Please refer to FIG. 4 , the embodiment of the present invention also discloses a cell handover device. The cell switching device 40 may include:

The receiving module 401 is configured to receive the first high-level signaling during the DAPS switching process of the dual active stack, the first high-level signaling indicates the release of at least one source serving cell, and multiple source serving cells provide services using carrier aggregation or dual connectivity ;

The processing module 402 is configured to release the connection with the at least one source serving cell.

Further, the receiving module 401 of the cell handover device 40 may also receive a second high-level signaling, the second high-level signaling instructs to release the sources of the plurality of source serving cells except the at least one source serving cell. Serve the community. The processing module 402 releases the connection with the other source serving cell.

Further, multiple target serving cells provide services by using carrier aggregation or dual connectivity, and the target serving cells include a target primary cell and a target secondary cell. The cell switching device 40 may further include an access module, configured to access the target primary cell, the target secondary cell being in an inactive state or a dormant state; a first data converting module, configured to convert the target primary cell The first data radio bearer performs uplink data conversion.

Further, the cell handover apparatus 40 may further include: a second data conversion module, configured to perform uplink data conversion on the data radio bearer transmitted by the at least one source serving cell, and the data radio bearer is configured to perform DAPS handover.

Wherein, the data conversion module may perform uplink data conversion on the data radio bearer transmitted by the at least one source serving cell at the same time.

In a specific implementation, the above-mentioned cell switching device may correspond to a chip with a cell switching function in the terminal equipment, such as a SOC (System-On-a-Chip, system on a chip), a baseband chip, etc.; A chip module with a switching function; or a chip module corresponding to a chip with a data processing function, or corresponding to a terminal device.

Please refer to FIG. 5 , the embodiment of the present invention also discloses a cell handover device. The cell switching device 50 may include:

The configuration module 501 is configured to configure the first high-level signaling during the DAPS switching process of the dual active stack, the first high-level signaling indicates the release of at least one source serving cell, and multiple source serving cells use carrier aggregation or dual connectivity to provide services ;

A sending module 502, configured to send the first high layer signaling.

In a non-limiting embodiment, the configuration module 501 configures the first high-layer signaling at least when downlink data of the data radio bearer transmitted by the at least one source serving cell is all transmitted by the target serving cell.

Further, the configuration module 501 judges whether the downlink data of the data radio bearer is transmitted by the target serving cell through the PDCP status report.

In another non-limiting embodiment, the configuration module 501 is configured when the downlink data of the data radio bearer is all transmitted by the target serving cell, and the uplink data of the data radio bearer does not need to be transmitted by the at least one source serving cell, Configure the first high-layer signaling.

Further, the configuration module 501 may include: a starting sequence number determining unit, configured to determine the starting sequence number of the data packet received when the uplink number is converted; a judging unit, configured to And the starting sequence number judges whether the uplink data packets whose sequence numbers are before the starting sequence number are all successfully received; the determination unit is used to determine if the uplink data packets whose sequence numbers are before the starting sequence number are all successfully received , it is determined that the uplink data of the data radio bearer does not need to be transmitted by the at least one source serving cell.

In a specific implementation, the above-mentioned cell switching device may correspond to a chip with a cell switching function in the network equipment, such as a SOC (System-On-a-Chip, system on chip), a baseband chip, etc.; A chip module with a switching function; or corresponding to a chip module with a data processing function chip, or corresponding to a network device.

For more details about the working principles and working methods of the cell switching device 40 and the cell switching device 50 , reference may be made to the related descriptions in FIG. 1 to FIG. 3 , which will not be repeated here.

Regarding each device described in the above embodiments, each module/unit contained in the product may be a software module/unit, or a hardware module/unit, or may be partly a software module/unit and partly a hardware module/unit. . For example, for each device or product applied to or integrated in a chip, each module/unit contained therein may be realized by hardware such as a circuit, or at least some modules/units may be realized by a software program, and the software program Running on the integrated processor inside the chip, the remaining (if any) modules/units can be realized by means of hardware such as circuits; They are all realized by means of hardware such as circuits, and different modules/units can be located in the same component (such as chips, circuit modules, etc.) or different components of the chip module, or at least some modules/units can be realized by means of software programs, The software program runs on the processor integrated in the chip module, and the remaining (if any) modules/units can be realized by hardware such as circuits; /Units can be realized by means of hardware such as circuits, and different modules/units can be located in the same component (such as chips, circuit modules, etc.) or different components in the terminal, or at least some modules/units can be implemented in the form of software programs Realization, the software program runs on the processor integrated in the terminal, and the remaining (if any) modules/units can be implemented by means of hardware such as circuits.

The embodiment of the present invention also discloses a storage medium, the storage medium is a computer-readable storage medium, and a computer program is stored thereon, and the steps of the access control method shown in FIG. 3 can be executed when the computer program is running. . The storage medium may include ROM, RAM, magnetic or optical disks, and the like. The storage medium may also include a non-volatile memory (non-volatile) or a non-transitory (non-transitory) memory, and the like.

The embodiment of the present invention also discloses a terminal device. The terminal device may include a memory and a processor, and a computer program that can run on the processor is stored in the memory. When the processor runs the computer program, it can execute the steps of the aforementioned cell handover method. The terminal equipment includes but is not limited to mobile phones, computers, tablet computers and other terminal equipment.

The embodiment of the present invention also discloses a network device. The network device may include a memory and a processor, and a computer program that can run on the processor is stored in the memory. When the processor runs the computer program, it can execute the steps of the aforementioned cell handover method.

The embodiment of this application defines the one-way communication link from the access network to the terminal as the downlink, the data transmitted on the downlink is downlink data, and the transmission direction of the downlink data is called the downlink direction; The one-way communication link is an uplink, the data transmitted on the uplink is uplink data, and the transmission direction of the uplink data is called the uplink direction.

It should be understood that the term "and/or" in this article is only an association relationship describing associated objects, indicating that there may be three relationships, for example, A and/or B may mean: A exists alone, and A and B exist at the same time , there are three cases of B alone. In addition, the character "/" in this article indicates that the associated objects are an "or" relationship.

"Multiple" appearing in the embodiments of the present application means two or more.

The first, second, etc. descriptions that appear in the embodiments of this application are only for illustration and to distinguish the description objects, and there is no order, nor does it represent a special limitation on the number of devices in the embodiments of this application, and cannot constitute a limitation on the number of devices in this application. Any limitations of the examples.

The "connection" in the embodiment of the present application refers to various connection modes such as direct connection or indirect connection to realize communication between devices, which is not limited in the embodiment of the present application.

It should be understood that, in the embodiments of the present application, the processor may be a central processing unit (CPU for short), and the processor may also be other general-purpose processors, digital signal processors (digital signal processor, DSP for short) , application specific integrated circuit (ASIC for short), off-the-shelf programmable gate array (field programmable gate array, FPGA for short) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor, or the processor may be any conventional processor, or the like.

It should also be understood that the memory in the embodiments of the present application may be a volatile memory or a nonvolatile memory, or may include both volatile and nonvolatile memories. Among them, the non-volatile memory can be read-only memory (read-only memory, referred to as ROM), programmable read-only memory (programmable ROM, referred to as PROM), erasable programmable read-only memory (erasable PROM, referred to as EPROM) , Electrically Erasable Programmable Read-Only Memory (electrically EPROM, referred to as EEPROM) or flash memory. The volatile memory can be random access memory (RAM), which acts as an external cache. By way of illustration and not limitation, many forms of random access memory (RAM) are available, such as static random access memory (static RAM (SRAM), dynamic random access memory (DRAM), synchronous Dynamic random access memory (synchronous DRAM, referred to as SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, referred to as DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, referred to as ESDRAM), Synchronously connect dynamic random access memory (synchlink DRAM, referred to as SLDRAM) and direct memory bus random access memory (direct rambus RAM, referred to as DR RAM).

The above-mentioned embodiments may be implemented in whole or in part by software, hardware, firmware or other arbitrary combinations. When implemented using software, the above-described embodiments may be implemented in whole or in part in the form of computer program products. The computer program product comprises one or more computer instructions or computer programs. When the computer instruction or computer program is loaded or executed on the computer, the processes or functions according to the embodiments of the present application will be generated in whole or in part. 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 or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website, computer, server or data center Wired or wireless transmission to another website site, computer, server or data center. The computer-readable storage medium may be any available medium that can be accessed by a computer, or a data storage device such as a server or a data center that includes one or more sets of available media.

It should be understood that, in various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the order of execution, and the execution order of the processes should be determined by their functions and internal logic, and should not be used in the embodiments of the present application. The implementation process constitutes any limitation.

In the several embodiments provided in this application, it should be understood that the disclosed methods, devices and systems can be implemented in other ways. For example, the device embodiments described above are only illustrative; for example, the division of the units is only a logical function division, and there may be other division methods in actual implementation; for example, multiple units or components can be combined or May be integrated into another system, or some features may be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, each unit may be physically included separately, or two or more units may be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware, or in the form of hardware plus software functional units.

The above-mentioned integrated units implemented in the form of software functional units may be stored in a computer-readable storage medium. The above-mentioned software functional units are stored in a storage medium, and include several instructions to enable a computer device (which may be a personal computer, server, or network device, etc.) to execute some steps of the methods described in various embodiments of the present invention.

Although the present invention is disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so the protection scope of the present invention should be based on the scope defined in the claims.

Claims (17)

A cell switching method, characterized in that, comprising: During the dual-active stack DAPS handover process, the first high-level signaling is received, the first high-level signaling indicates the release of at least one source serving cell, and multiple source serving cells use carrier aggregation or dual connectivity to provide services, and the at least one source The serving cell is part or all of the multiple source serving cells; releasing the connection with the at least one source serving cell. The cell handover method according to claim 1, wherein the at least one source serving cell is part of the multiple source serving cells, and the method further comprises: receiving second high-level signaling, where the second high-level signaling indicates to release other source serving cells in the plurality of source serving cells except the at least one source serving cell; Release the connection with the other source serving cell. The cell handover method according to claim 1, wherein, before receiving the first high-level signaling, the method comprises: performing uplink data conversion on at least one data radio bearer configured as dual active stack DAPS handover, and the at least one source serving cell transmits part or all of the at least one data radio bearer. The cell handover method according to claim 3, wherein the number of the target serving cell is one, and performing uplink data conversion on at least one data radio bearer configured as DAPS handover comprises: At the same time, uplink data conversion is performed on the at least one data radio bearer configured as dual active stack DAPS handover. The cell handover method according to claim 1, wherein a plurality of target serving cells are configured in the handover command, the target serving cells include a target primary cell and a target secondary cell, and before receiving the first high-layer signaling includes: Accessing the target primary cell, where the target secondary cell is in an inactive state or a dormant state; performing uplink data conversion on the first data radio bearer transmitted by the target primary cell. The cell handover method according to claim 5, characterized in that before receiving the second high-level signaling, it also includes: accessing the target secondary cell; performing uplink data conversion on the second data radio bearer transmitted by the target secondary cell. The cell switching method according to claim 1, further comprising: Sending uplink signaling, where the uplink signaling carries a notification message, where the notification message indicates that the connection with the at least one source serving cell has been released. A cell switching method, characterized in that, comprising: During the dual-active stack DAPS handover process, the first high-level signaling is configured, the first high-level signaling indicates the release of at least one source serving cell, and multiple source serving cells use carrier aggregation or dual connectivity to provide services, and the at least one source The serving cell is part or all of the multiple source serving cells; Send the first high-layer signaling. The cell handover method according to claim 8, wherein the configuring the first high-level signaling comprises: Configuring the first high-layer signaling at least when the downlink data of the data radio bearer transmitted by the at least one source serving cell is all transmitted by the target serving cell. The cell handover method according to claim 9, characterized in that before configuring the first high-level signaling, it also includes: It is judged whether the downlink data of the data radio bearer is all transmitted by the target serving cell through the PDCP status report. The cell handover method according to claim 9, wherein at least when the downlink data of the data radio bearer is transmitted by the target serving cell, configuring the first high-level signaling includes: When the downlink data of the data radio bearer is all transmitted by the target serving cell, and the uplink data of the data radio bearer does not need to be transmitted by the at least one source serving cell, configuring the first high-layer signaling. The cell handover method according to claim 11, characterized in that before configuring the first high-level signaling, it further comprises: Determine the starting sequence number of the data packet to start receiving when the uplink number is converted; According to the sequence number of the received uplink data packet and the initial sequence number, it is judged whether the uplink data packets whose sequence numbers are located before the initial sequence number are all received successfully; If the uplink data packets whose sequence numbers are before the starting sequence number are all successfully received, it is determined that the uplink data of the data radio bearer does not need to be transmitted by the at least one source serving cell. A cell handover device, characterized in that it comprises: The receiving module is configured to receive first high-level signaling during the DAPS switching process of the dual active stack, the first high-level signaling indicates the release of at least one source serving cell, and multiple source serving cells provide services using carrier aggregation or dual connectivity, The at least one source serving cell is part or all of the multiple source serving cells; A processing module, configured to release the connection with the at least one source serving cell. A cell handover device, characterized in that it comprises: A configuration module, configured to configure first high-level signaling during the DAPS handover process of dual active stacks, the first high-level signaling indicates the release of at least one source serving cell, and multiple source serving cells provide services using carrier aggregation or dual connectivity, The at least one source serving cell is part or all of the multiple source serving cells; A sending module, configured to send the first high-layer signaling. A computer-readable storage medium, on which a computer program is stored, wherein, when the computer program is run by a processor, the steps of the cell handover method according to any one of claims 1 to 12 are executed. A terminal device, comprising a memory and a processor, the memory stores a computer program that can run on the processor, and it is characterized in that, when the processor runs the computer program, it executes claims 1 to 7 Steps in any one of the cell handover methods. A network device, comprising a memory and a processor, the memory stores a computer program that can run on the processor, and it is characterized in that, when the processor runs the computer program, it executes claims 8 to 12. Steps in any one of the cell handover methods.

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