CN115038132A

CN115038132A - DAPS switching method and device of base station

Info

Publication number: CN115038132A
Application number: CN202210973452.2A
Authority: CN
Inventors: 邓勇志; 邵世才; 王贻先
Original assignee: Wuhan Shiju Information Technology Co ltd
Current assignee: Wuhan Shiju Information Technology Co ltd
Priority date: 2022-08-15
Filing date: 2022-08-15
Publication date: 2022-09-09
Anticipated expiration: 2042-08-15
Also published as: CN115038132B

Abstract

The application discloses a DAPS switching method and device of a base station. Aiming at the problem of complex process of configuring channel information, the following technical scheme is provided, wherein a central unit receives switching channel request information containing DAPS bearing information from a source base station; the central unit sends the DAPS bearing information to a distribution unit of the target base station through an F1 interface; and the distribution unit configures the terminal air interface parameters of the channel for the terminal according to the DAPS bearer information so as to reduce the complexity of the channel information configured by the base station. The distribution unit directly obtains the DAPS bearing information of the terminal, so that the subsequent distribution unit can conveniently configure channel information for the terminal to carry out DAPS switching. Compared with the prior art, the technical scheme does not need the central unit to participate in configuring the channel parameters and scheduling resources, so that no additional mechanism is needed to ensure the consistency of configuration between the central unit and the distribution units, and the complexity of DAPS handover is reduced.

Description

DAPS switching method and device of base station

Technical Field

The present application relates to the field of wireless communications technologies, and in particular, to a method and an apparatus for performing a DAPS handover for a base station.

Background

In 4G and 5G networks, when a user equipment is handed over between a source base station and a target base station, the user equipment needs to release the connection with the source base station before establishing the connection with the target base station. That is, the uplink and downlink data transmission of the ue is finished at the source base station, and then the uplink and downlink data transmission with the target base station is started. There is a time interval of several tens of milliseconds between the user equipment being disconnected from the source base station and the user equipment being connected to the target base station. This interval causes a communication interruption to the user equipment. Such communication interruptions are fatal to URLLC traffic and procedures using 5G networks.

The 3GPP proposes a solution to solve the communication interruption: a Dual Active Protocol Stack (DAPS) is used. In the protocol, when the user equipment is handed over between the source base station and the target base station, data transmission is maintained between the user equipment and the source base station until the user equipment can perform data transmission with the target base station. The user equipment using the DAPS handover needs to configure the DAPS bearer so that the user equipment can simultaneously transmit data with the source base station and the target base station.

In the preparation stage of DAPS handover, the handover target base station needs to reserve corresponding air interface resources for the ue and configure a handover command. The handover command contains parameters indicating that the radio bearer is a DAPS bearer.

For DAPS handover of 5G base stations with split architecture, the Central Unit (CU) completes the assembly and encoding of the final handover command, and part of the Cell Group configuration information (Cell Group configuration) in the handover command is typically filled by the Distribution Unit (DU) and then sent to the central Unit. The DAPS information is included in the channel correlation configuration. However, according to the F1AP protocol, the distribution unit cannot receive the DAPS information, and thus cannot configure air interface parameters and schedule resources for the DAPS-switched terminal in a targeted manner.

One prior art technique does not consider the DAPS related information elements when the distribution unit configures the channel related configuration. When the central unit receives the channel correlation configuration configured by the distribution unit, the central unit decodes the channel correlation configuration and complements and perfects the DAPS correlation cells in the channel correlation configuration, and finally DAPS switching is completed.

In another prior art, the central unit pre-fills the channel-related configuration containing the DAPS-related cells, and then sends the channel-related configuration to the distribution unit via the F1 interface, and the distribution unit sends the final channel-related configuration content to the central unit, thereby finally completing the DAPS handover.

In the process of implementing the prior art, the inventor finds that:

both of these two prior arts require additional mechanisms to ensure the consistency of configuration between the central unit and the distribution unit, which complicates the process of configuring the channel-related configuration information for the DAPS-handed over terminal by the base station.

Disclosure of Invention

In view of the defects in the prior art, a first object of the present application is to provide a DAPS handover method for a base station, where a distribution unit obtains DAPS bearer information through an F1 interface, and only the distribution unit needs to configure channel information for a terminal according to the DAPS bearer information, so that the complexity of configuring channel information for the terminal for DAPS handover by the base station is reduced.

In order to achieve the purpose, the application provides the following technical scheme:

a DAPS handover method of a base station includes the following steps:

the central unit receives switching channel request information containing DAPS bearing information from a source base station;

the central unit sends the DAPS bearing information to a distribution unit of the target base station through an F1 interface;

and the distribution unit configures the terminal air interface parameters of the channel for the terminal according to the DAPS bearer information so as to reduce the complexity of the channel information configured by the base station.

Further, the method, when the central unit receives the handover channel request information containing the DAPS bearer information from the source base station, specifically includes the following steps:

when the central unit receives the switching channel request information from the source base station, the central unit judges whether the switching channel request information contains DAPS bearing information;

when the handover channel request information includes the DAPS bearer information, the central unit determines to receive the handover channel request information including the DAPS bearer information from the source base station to prepare the central unit for performing the DAPS handover.

Further, the central unit sends the DAPS bearer information to the distribution unit of the target base station through an F1 interface, which specifically includes the following steps:

the central unit judges whether the terminal meets the access condition or not according to the DAPS bearing information;

when the terminal meets the access condition, the central unit configures DAPS data radio bearer for the terminal according to the DAPS bearer information and generates a data radio bearer configuration condition list;

the central unit sends the DAPS bearer information and the data radio bearer configuration list to the distribution unit via the F1 interface.

Further, the method also comprises the following steps:

and the distribution unit of the target base station starts pre-scheduling for the terminal according to the DAPS bearing information so as to improve the priority of the target base station for scheduling data for the terminal requesting DAPS switching, thereby reducing the time delay of DAPS switching.

Further, the method also comprises the following steps:

after the DAPS handover is completed, the central unit of the target base station sends the terminal context modification request information containing the DAPS bearer release information to the distribution unit of the target base station through an F1 interface;

and the distribution unit of the target base station closes the pre-scheduling opened for the terminal according to the DAPS bearer release information so as to save scheduling resources.

Further, the method also comprises the following steps:

the source base station selects a target base station according to a measurement report reported by the terminal and a local switching strategy;

and the source base station establishes connection with the target base station according to the link interface and sends switching channel request information to the target base station.

Further, the link interface adopts an XN link interface and/or an NG link interface.

In view of the defects in the prior art, a second object of the present application is to provide a DAPS handover apparatus for a base station, which has an advantage of low complexity of a process for configuring channel configuration information for a terminal for DAPS handover by the base station.

In order to achieve the above purpose, the present application provides the following technical solutions:

a DAPS handover apparatus of a base station, comprising:

a switching channel request information obtaining unit, which is arranged in the central unit, is in communication connection with the source base station, and is used for receiving switching channel request information containing DAPS bearing information from the source base station;

a DAPS bearer information receiving unit, disposed in the central unit, and communicatively connected to the handover channel request information obtaining unit, where the DAPS bearer information receiving unit is communicatively connected to an F1 interface, and the F1 interface is communicatively connected to a distribution unit, and is used to send DAPS bearer information to the distribution unit of the target base station through an F1 interface;

and the channel parameter configuration unit is arranged in the distribution unit, is in communication connection with the DAPS bearer information receiving unit, and is used for configuring terminal air interface parameters of a channel for the terminal according to the DAPS bearer information so as to reduce the complexity of channel information configuration of the base station.

Further, the method also comprises the following steps:

and the judging unit is arranged in the central unit, is in communication connection with the switching channel request information acquiring unit, and is used for judging whether the switching channel request information contains DAPS bearing information.

Further, still include:

and the pre-scheduling unit is arranged in the distribution unit, is in communication connection with the terminal, and is used for starting pre-scheduling for the terminal according to the DAPS bearer information so as to improve the priority of the target base station for scheduling data for the terminal, thereby reducing the time delay of DAPS handover.

In summary, the present application has the following beneficial effects:

the central unit sends the DAPS bearer information to the distribution unit through an F1 interface, so that the distribution unit obtains the DAPS bearer information. That is, the distribution unit directly obtains the DAPS bearer information of the terminal, so that the subsequent distribution unit can configure the channel information for the terminal to perform the DAPS handover. Compared with the prior art, the method and the device do not need the central unit to participate in configuring the channel parameters and scheduling resources, so that no additional mechanism is needed to ensure the consistency of configuration between the central unit and the distribution units, and the complexity of DAPS handover is reduced.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

fig. 1 is a schematic diagram illustrating steps of a DAPS handover method of a base station.

Fig. 2 is a schematic diagram illustrating a specific step of the central unit in fig. 1 receiving a handover channel request message containing DAPS bearer information from a source base station.

Fig. 3 is a schematic diagram illustrating a specific step of the central unit in fig. 1 sending the DAPS bearer information to the distribution unit of the target base station through an F1 interface.

Fig. 4 is a schematic diagram of steps further included in the DAPS handover method of the base station.

Fig. 5 is a schematic structural diagram of a DAPS handover apparatus of a base station.

Fig. 6 is a general flowchart of the DAPS handover method of the base station.

100 base station DAPS handover device

11 switching channel request information acquisition unit

12DAPS bearing information receiving unit

13 channel parameter configuration unit

14 judging unit

15 pre-scheduling unit.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be described in detail and completely with reference to the following specific embodiments of the present application and the accompanying drawings. It should be apparent that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The present application provides a DAPS handover method for a base station, referring to fig. 1, including the following steps:

s100: the central unit receives a handover channel request message containing the DAPS bearer information from the source base station.

In this application, the source base station is a base station to which the terminal is currently in data connection. The target base station is the base station to which the terminal is about to prepare a data connection. A Central Unit (CU) is located in a central office in a base station split architecture. A Distributed Unit (DU) is installed in a site room in the base station separation architecture. The distribution unit is used for providing wireless communication service for the service cell according to the data distributed by the central unit. The central unit is used for configuring data to the distribution units. The distribution unit and the central unit are connected by optical fibers. The central unit and the distribution unit are both arranged at the target base station. DAPS is a Dual Active Protocol Stack (DAPS). In the protocol, when the terminal is handed over between the source base station and the target base station, data transmission is maintained between the terminal and the source base station until the terminal can perform data transmission with the target base station. This requires that the terminal simultaneously receive and transmit data between both the source and target base stations during the DAPS handover. The handover channel request information is information transmitted from the source base station to the target base station. The content of the switching channel request information is a terminal request for establishing data connection with a target base station. The DAPS bearer Information (DAPS Request Information) is an Information element carried in the handover channel Request Information. The DAPS Bearer information is used to indicate that a Data Radio Bearer (DRB) of the terminal is a DAPS Bearer. A data radio bearer is a channel used to carry data transmissions. The terminal configured with the DAPS bearer may perform a DAPS handover.

Further, referring to fig. 2, step S100 specifically includes the following steps:

s101: when the central unit receives the switching channel request information from the source base station, the central unit judges whether the switching channel request information contains DAPS bearing information.

In this application, the DAPS bearer information includes information that the data radio bearer of the terminal is a DAPS bearer and information that the service quality of the data radio bearer of the terminal meets the URLLC requirement or the local DAPS configuration policy.

S102: when the handover channel request information includes the DAPS bearer information, the central unit determines to receive the handover channel request information including the DAPS bearer information from the source base station to prepare the central unit for performing the DAPS handover.

In the present application, when the handover channel request message includes the DAPS bearer message, the central unit determines that the DAPS bearer message is received, and prepares for the terminal to perform DAPS handover. When the switching channel request message does not contain the DAPS bearer message, the central unit does not receive the DAPS bearer message, and prepares for normal switching except for the DAPS switching.

Specifically, the control plane of the central unit sends a bearer context setup request message including the successfully admitted DAPS bearer information to the user plane of the central unit. And the user plane of the central unit configures the DAPS bearer for the terminal aiming at the DAPS bearer information. The user of the central unit feeds back a bearer context setup response message containing the DAPS bearer list information whether the configuration was successful or not to the control plane of the central unit.

It can be understood that the central unit of the target base station determines whether the handover channel request information includes DAPS bearer information, thereby obtaining information whether the data radio bearer carried by the terminal is a DAPS bearer or a normal bearer, so as to determine whether the terminal requests a DAPS handover or a normal handover. When it is determined that the data radio bearer of the terminal is a DAPS bearer, the central unit of the target base station prepares to perform a DAPS handover. When it is determined that the data radio bearer of the terminal is an ordinary bearer, the central unit of the target base station prepares to perform an ordinary handover. The step of judging is added, so that the base station system has more selectivity, not only can perform DAPS handover, but also can perform common handover, and the application range is increased.

S200: the central unit sends the DAPS bearer information to the distribution unit of the target base station over the F1 interface.

In this application, the F1 interface is the interface for data connection between the central unit and the distribution unit. Specifically, the DAPS bearer Information is indicated by adding an F1 interface cell DAPS Request Information.

Further, referring to fig. 3, step S200 specifically includes the following steps:

s201: and the central unit judges whether the terminal meets the admission condition or not according to the DAPS bearing information.

In this application, the admission condition is a condition that the target base station grants the terminal access. The specific content of the admission condition is that the load condition of the target base station can accept the access of the terminal carrying the DAPS bearer. When the target base station receives the DAPS terminal access request, the target base station judges whether the load for providing communication service for the terminal provided with the DAPS bearer can be borne or not according to the load condition of the target base station.

S202: when the terminal meets the access condition, the central unit configures the DAPS data radio bearer for the terminal according to the DAPS bearer information and generates a data radio bearer configuration condition list.

In the present application, when the load condition of the target base station can bear the load of providing service for the terminal, the target base station prepares to access the terminal. When the load condition of the target base station can not accept the new access request, the target base station refuses the connection with the terminal so as to ensure the stable work of the target base station and avoid the overload of the target base station.

The data radio bearer configuration case list is a list of which data radio bearers between the target base station and the terminal are successfully connected and which data radio bearers are failed.

Specifically, the control plane of the central unit of the target base station sends a bearer context setup request message to the user plane of the central unit of the target base station. The bearer context setup request message includes the DAPS bearer information that the admission was successful. The user plane of the central unit of the target base station first configures the DAPS data radio bearer for the terminal, and then feeds back a bearer context setup response message including a data radio bearer configuration situation list to the control plane of the central unit of the target base station.

S203: the central unit sends the DAPS bearer information and the data radio bearer configuration list to the distribution unit via the F1 interface.

Specifically, the control plane of the central unit of the target base station sends a terminal context setup request message including the DAPS bearer information and the data radio bearer configuration case list to the distribution unit of the target base station through the F1 interface. The DAPS bearer Information is indicated by adding an F1 interface cell DAPS Request Information. The distribution unit of the target base station stores the DAPS bearing information, configures channel configuration information (Cell Group Config) according to the DAPS bearing information, and then feeds back the channel information to the control plane of the central unit of the target base station through a terminal context establishment response message.

It can be understood that, before receiving the access of the terminal provided with the DAPS bearer, the target base station evaluates whether the target base station can bear the DAPS handover of the terminal according to the current load condition of the target base station. That is, the DAPS handover requires more resources to be occupied than the normal handover, which increases the load of the base station. In order to ensure that the base station is not overloaded, the target base station evaluates the load condition of the target base station and then determines whether to approve the access of the terminal. Likewise, the purpose of the admission decision is to ensure the normal operation of the target base station, so that the target base station system does not crash.

The data radio bearer configuration condition list shows the details of the data radio bearer configuration for the terminal by the central unit, so that the distribution unit of the target base station configures the channel parameters for the terminal in more detail, and the configuration accuracy is improved.

S300: and the distribution unit configures the terminal air interface parameters of the channel for the terminal according to the DAPS bearing information so as to reduce the complexity of the channel information configured by the base station.

In this application, the air interface is an air interface. The terminal air interface is an air path, i.e. an air interface, between the terminal and the distribution unit. The terminal air interface parameter is an interface parameter connected between the terminal and the distribution unit of the target base station. That is, the terminal air interface parameter is a key for connection between the terminal and the distribution unit of the target base station. And according to the air interface parameters, the target base station allows the terminal to establish data connection with the target base station, so that the terminal can be randomly accessed into the target base station.

It is understood that the central unit sends the DAPS bearer information to the distribution unit through the F1 interface, so that the distribution unit obtains the DAPS bearer information. That is, the distribution unit directly obtains the DAPS bearer information of the terminal, so that the subsequent distribution unit can configure the channel information for the terminal to perform the DAPS handover. Compared with the prior art, the method and the device do not need the central unit to participate in configuring the channel parameters and scheduling resources, so that no additional mechanism is needed to ensure the consistency of configuration between the central unit and the distribution units, and the complexity of DAPS switching is reduced.

Further, referring to fig. 1, the method further includes the following steps:

s400: and the distribution unit of the target base station starts pre-scheduling for the terminal according to the DAPS bearing information so as to improve the priority of the target base station for scheduling data for the terminal requesting the DAPS switching, thereby reducing the time delay of the DAPS switching.

It can be understood that the pre-scheduling is that the base station allocates resources to the terminal before the terminal requests the base station to allocate resources to the terminal, so as to reduce the time delay of data transmission between the terminal and the base station. In the prior art, after the base station receives the request information for switching the channel, the base station allocates resources to the terminal. Compared with the prior art, the method and the system have the advantages that resources are scheduled in advance, time delay is reduced, and data connection between the terminal requesting the DAPS handover and the target base station is faster.

In addition, the target base station starts pre-scheduling for the terminal provided with the DAPS bearer, and the target base station is distinguished from the terminal provided with the common bearer to improve the priority of scheduling data for the terminal so as to further reduce the data plane time delay in the DAPS switching process and improve the efficiency of the DAPS switching. The differentiation processing between the DAPS switching and the ordinary switching ensures that the resource scheduling of the base station is more flexible and the advantage of the DAPS switching is highlighted.

Further, referring to fig. 1, the method further includes the following steps:

s500: after the DAPS handover is completed, the central unit of the target base station sends the terminal context modification request information containing the DAPS bearer release information to the distribution unit of the target base station through the F1 interface.

In the present application, the request information for modifying the context of the terminal, which includes the DAPS bearer release information, is information for modifying the data resource configuration corresponding to the DAPS bearer of the terminal into the data resource configuration corresponding to the normal bearer. The F1 interface is a data transfer interface between the connection center unit and the distribution unit. Specifically, the central unit adds a DAPS bearer release information element through an F1 interface, so as to implement that the distribution unit receives the DAPS bearer release information.

S600: and the distribution unit of the target base station closes the pre-scheduling opened for the terminal according to the DAPS bearer release information so as to save scheduling resources.

It can be understood that, the F1 interface implements the transfer of the terminal context modification request information of the DAPS bearer release information, thereby implementing the adjustment of the resources configured by the target base station for the terminal from the resources corresponding to the DAPS bearer to the resources corresponding to the normal bearer. The resource of the terminal is only required to be scheduled by the distribution unit, and the central unit is not required to participate in the resource scheduling. No additional mechanism is needed to ensure the consistency of configuration between the central unit and the distribution unit, and the complexity of the DAPS handover is reduced.

When the terminal has completed the DAPS handover, the terminal can satisfy the data transmission requirement using the normal bearer. The target base station adjusts the priority of the terminal scheduling data to the scheduling data grade configured by the common bearer, thereby reducing the occupation of base station resources, improving the flexibility of the base station system for distributing the data resources and lightening the load of the base station system.

Further, referring to fig. 4, the method further includes the following steps:

s700: and the source base station selects the target base station according to the measurement report reported by the terminal and the local switching strategy.

In the application, the terminal can be a mobile phone, a notebook computer, a tablet computer and a vehicle-mounted computer. The measurement report is the location of the terminal and the moving speed of the terminal before handover. The local switching strategy is a method for configuring a channel for a terminal by a base station according to the service requirement and the transmission channel quality of the terminal. The target base station is a base station that conforms to the measurement report and the local handover policy among a plurality of base stations adjacent to the source base station.

S800: and the source base station establishes connection with the target base station according to the link interface and sends switching channel request information to the target base station.

In this application, a link is a path for establishing a data connection between a source base station and a target base station. The link interface is arranged between the source base station and the target base station. Through the link interface, a data connection is established between the source base station and the target base station. The link interface may be an XN interface.

The handover channel request message is a message that the terminal requests to establish a data connection with the target base station. And establishing a connection path for data transmission between the source base station and the target base station through the XN interface. The source base station sends the switching channel request information of the terminal to the target base station through the link interface so that the target base station prepares for establishing data connection with the terminal.

It can be understood that, the source base station selects a suitable target base station near the source base station according to the location distribution, the moving speed, the moving direction, the service requirement and the transmission channel quality of the terminal, so as to reduce the time delay of the terminal during DAPS handover due to mismatching between the terminal and the target base station, thereby ensuring that the terminal obtains a good communication service. When the link interface of the source base station is matched with the link interface of the target base station, the source base station can establish connection with the target base station, so that the target base station can receive the request information of the switching channel, and the smooth information transmission is ensured.

In this application, both the XN link interface and the NG link interface are data connection ports of the base station. The XN interface is the network interface between base stations. The NG interface is the interface between the radio access network and the core network.

It is understood that the source base station establishes a link according to whether the device is configured with an XN interface or an NG interface. The source base station can also select whether to establish a data connection with the target base station through the XN interface or the NG interface according to the quality of the channel. The technical scheme can be popularized and applied to DAPS switching based on the XN interface and DAPS switching based on the NG interface, the application range is enlarged, and the compatibility is realized.

Referring to fig. 6, the method further comprises the following steps:

and the target base station sends a channel switching command comprising the terminal air interface parameters of the channel to the source base station.

And the source base station sends a channel switching command to the terminal according to the terminal air interface parameter of the channel, continues data connection with the terminal, and simultaneously sends early state transmission information containing the DAPS bearing information to the target base station.

And the target base station starts up uplink and downlink forwarding data caching according to the early state transmission information so as to prepare for establishing data connection with the terminal.

And the terminal establishes data connection with the target base station according to the channel switching command.

Specifically, the control plane of the central unit of the target base station populates the RRC reconfiguration information with channel configuration information. The RRC reconfiguration cell contains a terminal air interface parameter. And the target base station encodes the RRC reconfiguration cell to form a switching channel command message, and sends the switching channel command message to the source base station through the switching channel request message.

And the source base station extracts the terminal air interface parameters of the channel in the RRC reconfiguration cell in the switching channel request. The source base station transmits a channel switching command to the terminal. And the source base station configures a DRB forwarding tunnel according to the data forwarding information carried in the switching channel request message, and then sends the PDCP-SN and HFN of the first downlink data packet forwarded on each DAPS bearer to the target base station through early state transmission information. The source base station starts data forwarding and continues to send data to the terminal for the DAPS bearer.

The early status transmission information is physical layer information for early data transmission. And after receiving the early state transmission information, the target base station starts uplink and downlink forwarding data caching. After the terminal receives the switching channel command sent by the source base station, the terminal configures the DAPS bearer according to the content of the switching channel command message. And simultaneously, the terminal starts to synchronize to the target base station and initiates a random access process. And after the terminal finishes the random access, sending an RRC reconfiguration completion message to the target base station.

When the target base station receives the RRC reconfiguration complete message, the distribution unit of the target base station sends Downlink Data Delivery Status (DDDS) to the user plane of the central unit of the target base station through the F1-U protocol, so as to start the target base station to send Downlink Data to the terminal. And the target base station sends a switching completion message to the source base station to inform the source base station that the terminal has successfully accessed the target cell.

It can be understood that, after receiving the channel switching command of the terminal air interface parameter of the channel, the source base station indicates that the target base station is ready for DAPS switching, and at this time, the source base station sends the channel switching command to the terminal, so that the terminal is ready to establish data connection with the target base station. The source base station continues to be in data connection with the terminal according to the stipulation of the DAPS switching protocol, so that the data service of the terminal is ensured to be uninterrupted all the time in the switching process, and the time delay caused by switching is reduced. The target base station receives the early state transmission information, and indicates that the target base station is ready to establish data connection with the terminal. Data caching is the temporary holding of data for reading and re-reading. The uplink and downlink forwarding data cache comprises an uplink forwarding data cache and a downlink forwarding data cache. The uplink forwarding data buffer is used for temporarily storing data uploading. The downlink forwarding data buffer is used for temporarily storing the data downloading. After the target base station starts up the uplink and downlink forwarding data caching, a 'gear port' of data connection is reserved for the terminal so as to be ready for data uploading or downloading between the terminal and the target base station. And the target base station receives the RRC reconfiguration completion message to indicate that the terminal and the base station complete synchronization and random access.

Referring to fig. 6, the method further comprises the following steps:

and when the source base station obtains the PDCP SN state carried by the DAPS according to the switching success information, forwarding the information to the target base station through the SN state.

When the control plane of the central unit of the target base station receives the SN state forwarding information, the PDCP SN state is transmitted to the user plane of the central unit of the target base station through the bearing context modification request message, and meanwhile, the control plane of the central unit of the target base station sends the terminal context modification request message to the distribution unit of the target base station so as to instruct the distribution unit of the target base station to restore the DAPS bearing to the common bearing to carry out scheduling processing on the terminal.

And the target base station sends an RRC reconfiguration cell to the terminal, wherein the RRC reconfiguration cell comprises a DAPS bearer release cell to indicate the terminal to release the source cell related configuration of the DAPS bearer.

The target base station sends a path switching request message to an Access and Mobility Management Function (AMF) to start downlink data path switching, which is shown in fig. 6 for downlink RRC message transmission. And after completing the path switching, the core network sends a path switching request acknowledge message to the target base station.

And the target base station sends a terminal connection release message to the source base station.

And when the source base station receives the terminal connection release message, the source base station stops providing communication service for the terminal.

In this application, a cell is a basic unit of Asynchronous Transfer Mode (ATM) switching and multiplexing.

Specifically, the control plane of the central unit of the target base station sends a terminal context modification request message to the distribution unit of the target base station to indicate the release of the source cell related configuration carried by the DAPS. The source cell related configuration release of the DAPS bearer is indicated by the new F1 interface information element DAPS bearer release information. And after receiving the DAPS bearer release information, the distribution unit of the target base station restores all DAPS bearers of the terminal to be common bearers for scheduling.

It is to be understood that the terminal does not need to be connected with the source base station when the DAPS handover is completed. That is, the terminal is disconnected from the source base station. The source base station reduces the data scheduling priority of the terminal and then disconnects the connection with the terminal. The connection between the source base station and the terminal is from high data configuration priority to low data priority, and finally, the connection is disconnected, so that the speed of data transmission between the source base station and the terminal is gradually reduced, and the stability of the system is ensured.

The present application further provides a DAPS handover apparatus 100 for a base station, which is adapted to a DAPS handover method for a base station, and with reference to fig. 5, the method includes:

a switching channel request information obtaining unit 11, disposed in the central unit, connected to the source base station in a communication manner, and configured to receive switching channel request information including DAPS bearer information from the source base station;

a DAPS bearer information receiving unit 12, disposed in the central unit, and communicatively connected to the handover channel request information obtaining unit 11, where the DAPS bearer information receiving unit 12 is communicatively connected to an F1 interface, and the F1 interface is communicatively connected to a distribution unit, and is configured to send the DAPS bearer information to the distribution unit of the target base station through an F1 interface;

and a channel parameter configuration unit 13, disposed in the distribution unit, and in communication connection with the DAPS bearer information receiving unit 12, and configured to configure a terminal air interface parameter of a channel for the terminal according to the DAPS bearer information, so as to reduce the complexity of configuring channel information by the base station.

In this application, the source base station is a base station to which the terminal is currently in data connection. The target base station is the base station to which the terminal is about to prepare a data connection. The distribution unit is arranged in a station machine room in the base station separation framework. The distribution unit is used for providing wireless communication service for the service cell according to the data distributed by the central unit. The central unit is arranged in a central machine room in the base station separation framework. The central unit is used for configuring data to the distribution units. The distribution unit and the central unit are connected by optical fibers. The central unit and the distribution unit are both arranged at the target base station. DAPS is a Dual Active Protocol Stack (DAPS). In the protocol, when the terminal is handed over between the source base station and the target base station, data transmission is maintained between the terminal and the source base station until the terminal can perform data transmission with the target base station. This requires that the terminal simultaneously receive and transmit data between both the source and target base stations during the DAPS handover.

Specifically, the switching channel request information acquisition unit 11 is in communication connection with the central unit. The switching channel request information obtaining unit 11 is in communication connection with the source base station. The switching channel request information obtaining unit 11 sends the switching channel request information sent by the source base station to the central unit, so that the central unit is ready to establish data connection with the terminal.

The DAPS bearer information is an information element carried in the handover channel request information. The DAPS Bearer information is used to indicate that a Data Radio Bearer (DRB) of the terminal is a DAPS Bearer. A data radio bearer is a channel used to carry data transmissions. The terminal configured with the DAPS bearer may perform a DAPS handover.

Specifically, the DAPS bearer information receiving unit 12 sends the DAPS bearer information of the central unit to the distribution unit through the F1 interface. The F1 interface is the interface for data connection between the central unit and the distribution units. The DAPS bearer information is indicated by adding an F1 interface cell DAPS bearer information.

The air interface is an air interface. The terminal air interface is an air path, i.e. an air interface, between the terminal and the distribution unit. The terminal air interface parameter is an interface parameter connected between the terminal and the distribution unit of the target base station. That is, the terminal air interface parameter is a key for the connection between the terminal and the distribution unit of the target base station. And allowing the terminal to establish data connection with the target base station according to the air interface parameters. The terminal gets random access to the target base station.

The channel parameter configuration unit 13 of the distribution unit processes the DAPS bearer information to generate a terminal air interface parameter of the channel, where the terminal air interface parameter of the channel is adapted to a terminal equipped with a DAPS bearer, and one-to-one correspondence between the terminal and the distribution unit is realized.

It will be appreciated that the central unit sends the DAPS bearer information to the distribution units via the F1 interface, so that the distribution units obtain the DAPS bearer information. That is, the distribution unit directly obtains the DAPS bearer information of the terminal, so that the subsequent distribution unit can configure the channel information for the terminal to perform the DAPS handover. Compared with the prior art, the device does not need the central unit to participate in configuring the channel parameters and scheduling resources, so that no additional mechanism is needed to ensure the consistency of configuration between the central unit and the distribution units, and the complexity of DAPS switching is reduced.

Further, the method also comprises the following steps: and a determining unit 14, disposed in the central unit, and connected to the handover channel request information obtaining unit 11 in a communication manner, for determining whether the handover channel request information includes DAPS bearer information.

In this application, the DAPS bearer information includes information that the data radio bearer of the terminal is a DAPS bearer. The DAPS bearer information also contains information that the quality of service of the terminal's data radio bearer meets URLLC requirements or local DAPS configuration policy.

When receiving the switching channel request information sent by the switching channel request information obtaining unit 11, the determining unit 14 determines whether the switching channel request information includes DAPS bearer information. When the switching channel request information contains the DAPS bearing information, the central unit is informed to determine that the DAPS bearing information is received, so that the central unit prepares for the terminal to carry out DAPS switching. When the switching channel request information does not contain the DAPS bearing information, the central unit is informed that the DAPS bearing information is not received, so that the central unit can prepare for ordinary switching except the DAPS switching.

It can be understood that the determining unit 14 determines whether the handover channel request information includes DAPS bearer information, and notifies the central unit of the determination result, so that the central unit obtains information of whether the data radio bearer carried by the terminal is a DAPS bearer or a normal bearer to determine whether the terminal requests a DAPS handover or a normal handover. When it is determined that the data radio bearer of the terminal is a DAPS bearer, the central unit of the target base station prepares to perform a DAPS handover. When it is determined that the data radio bearer of the terminal is an ordinary bearer, the central unit of the target base station prepares to perform an ordinary handover. The determining unit 14 makes the base station system more selective, and can perform both DAPS handover and normal handover, thereby increasing the application range of the handover device.

Further, the method also comprises the following steps: and the pre-scheduling unit 15 is arranged in the distribution unit, is in communication connection with the terminal, and is used for starting pre-scheduling for the terminal according to the DAPS bearer information so as to improve the priority of scheduling data by the target base station for the terminal.

It can be understood that the pre-scheduling is that the base station already allocates resources to the terminal before the terminal requests the base station to allocate resources to the terminal, so as to reduce the time delay of data transmission between the terminal and the base station. The pre-scheduling unit 15 starts pre-scheduling for the terminal with the DAPS bearer, separates the terminal with the DAPS bearer from the terminal with the normal bearer, and increases the priority of scheduling data for the terminal with the DAPS bearer, so as to further reduce the data plane delay in the DAPS handover process, thereby increasing the efficiency of the DAPS handover.

That is, when a terminal requesting a general handover needs to transmit data, the terminal needs to request the base station to allocate resources. And after receiving the request information, the base station allocates resources for the terminal. Compared with the scheme, the device enables the data connection between the terminal requesting the DAPS handover and the target base station to be faster, and reduces time delay. The pre-scheduling unit 15 processes differentiation between the DAPS handover and the normal handover, so that the resource scheduling of the base station is more flexible, and the advantage of the DAPS handover is highlighted.

While the preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all alterations and modifications as fall within the scope of the application.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. A DAPS handover method of a base station, comprising the steps of:

and the distribution unit configures the terminal air interface parameters of the channel for the terminal according to the DAPS bearing information so as to reduce the complexity of the channel information configured by the base station.

2. The DAPS handover method of a base station of claim 1, wherein the central unit receives a handover channel request message containing DAPS bearer information from a source base station, and specifically comprises the steps of:

3. The DAPS handover method of a base station according to claim 1, wherein the central unit sends the DAPS bearer information to the distribution unit of the target base station via an F1 interface, comprising the steps of:

4. The DAPS handover method of a base station according to claim 1, further comprising the steps of:

and the distribution unit of the target base station starts pre-scheduling for the terminal according to the DAPS bearing information so as to improve the priority of the target base station for scheduling data for the terminal requesting the DAPS switching, thereby reducing the time delay of the DAPS switching.

5. The DAPS handover method of a base station according to claim 1, further comprising the steps of:

6. The DAPS handover method of a base station according to claim 1, further comprising the steps of:

7. The DAPS handover method of a base station according to claim 6, wherein the link interface is an XN link interface and/or an NG link interface.

8. A DAPS handover apparatus of a base station, comprising:

a DAPS bearer information receiving unit, configured to be disposed in the central unit and communicatively connected to the handover channel request information obtaining unit, where the DAPS bearer information receiving unit is communicatively connected to an F1 interface, and the F1 interface is communicatively connected to the distribution unit, and is configured to send DAPS bearer information to the distribution unit of the target base station through an F1 interface;

9. The DAPS handover apparatus of a base station according to claim 8, further comprising:

and the judging unit is arranged in the central unit, is in communication connection with the switching channel request information acquiring unit and is used for judging whether the switching channel request information contains DAPS bearing information.

10. The DAPS handover apparatus of a base station according to claim 8, further comprising:

and the pre-scheduling unit is arranged in the distribution unit, is in communication connection with the terminal, and is used for starting pre-scheduling for the terminal according to the DAPS bearing information so as to improve the priority of the target base station for scheduling data for the terminal, thereby reducing the time delay of DAPS switching.