CN109587825B

CN109587825B - Method for establishing connection, method for requesting configuration of secondary cell group and corresponding base station

Info

Publication number: CN109587825B
Application number: CN201810029453.5A
Authority: CN
Inventors: 王弘; 许丽香; 柯小婉
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2017-09-28
Filing date: 2018-01-11
Publication date: 2024-03-01
Anticipated expiration: 2038-01-11
Also published as: CN109587825A

Abstract

The invention provides a method for establishing connection and a corresponding main base station and auxiliary base station, wherein the method comprises the following steps: sending an auxiliary base station establishment request message to an auxiliary base station; and receiving an auxiliary base station establishment response message, wherein the auxiliary base station establishment response message comprises mapping information from QoS Flow decided by the auxiliary base station to DRB. A method of requesting SCG configuration and corresponding primary and secondary base stations are also provided, wherein the method comprises: an auxiliary base station modification request message for requesting SCG configuration information is sent, wherein the auxiliary base station modification request message carries indication information for indicating that a main base station needs to obtain the SCG configuration information; and receiving an auxiliary base station modification response message sent by the auxiliary base station, wherein the auxiliary base station modification response message carries the SCG configuration information. A corresponding computer readable medium is also provided.

Description

Method for establishing connection, method for requesting configuration of secondary cell group and corresponding base station

Technical Field

The present invention relates to wireless communication technology, and more particularly, to a method of establishing a connection, a method for requesting Secondary Cell Group (SCG) configuration, a primary base station, a secondary base station, and a computer readable medium.

Background

5G refers to fifth generation mobile communication technology. Unlike the first four generations, 5G is not a single wireless technology, but rather a fusion of existing wireless communication technologies. At present, the peak rate of LTE can reach 100Mbps, and the peak rate of 5G can reach 10Gbps, which is improved by 100 times compared with 4G. The existing 4G network has limited spontaneous processing capability, and cannot support the services of partial high-definition video, high-quality voice, augmented reality, virtual reality and the like. The 5G will introduce more advanced technology, and jointly meet the requirement of mobile service traffic growth through higher frequency spectrum efficiency, more frequency spectrum resources, denser cells and the like, solve the problems faced by the 4G network, and construct a network community with high transmission rate, high capacity, low time delay, high reliability and excellent user experience. As shown in fig. 1, the 5G architecture includes a 5G access network, a 5G core network, and a User Equipment (UE) that communicates with a data network through the access network.

In network evolution, the first phase will continue to use LTE base stations while being able to support 5G terminals and use 5G features. Some 5G base stations may be deployed, which may act as secondary base stations, providing data transmission to the UE together with the LTE base station. There is no signaling connection between the 5G base station and the core network control node (mobility management entity (MME)), and only there is a connection to the user plane with the core network gateway (serving gateway (SGW)). The LTE base station and LTE core network can be reused in this architecture, which is attractive and desirable to operators. Specifically, the LTE base station configures a 5G base station, and adopts a dual connectivity technology defined in the LTE system to transmit technology to the UE. The LTE base station is used as a main base station, and the 5G base station is used as an auxiliary base station.

The dual connection type may have various bearer types, and as shown in fig. 2, the bearer for transmitting data may be divided into a split bearer (split bearer), an auxiliary bearer (secondary cell group (SCG) bearer), and an auxiliary split bearer (SCG split bearer). The splitting of the bearer means that the primary base station receives data from the core network and then splits the data into two paths, one path being sent from the primary base station to the UE and the other path being sent from the secondary base station to the UE. The SCG bearer is where the secondary base station receives data from the core network and then is sent to the UE by the secondary base station. The auxiliary segmentation bearer is that the auxiliary base station receives data from the core network, then segments the data, a part of the data is sent to the UE by the auxiliary base station, a part of the data is sent to the main base station, and the data is sent to the UE by the main base station. The auxiliary split bearer is a newly introduced bearer type, the user plane of which is shown in fig. 3.

In the 5G technology, some technologies different from the 4G technology are adopted, for example, in terms of quality of service (QoS) architecture, the 5G defines a new mode. At the time of protocol data unit Session (PDU Session) establishment, the core network issues default QoS policies or/and authenticated QoS policies to the Radio Access Network (RAN) and UE. The data connection is the transmission path between the UE to the core network. Including the transmission path between the core network and the base station and the radio bearer between the base station and the UE. PDU Session is the connection between the UE and the packet data network, which is used to transfer data units, typically one PDU Session is established for one service. The data unit types include IP data, ethernet data and non-IP data. When establishing PDU Session, the core network sends QoS strategy to RAN through NG interface and QoS strategy to UE through NAS interface. The QoS policy includes information indicating/describing QoS Flow, specific QoS information, such as a data delay target, a data error rate, a priority of data, a guaranteed data rate, a maximum data rate, and other information, such as information of an application layer. The RAN establishes a default Data Radio Bearer (DRB) according to QoS requirements, and can establish other DRBs in addition to the default DRB. In the user plane, the core network composes the data packet into QoS Flow, the QoS indication information is added to the data head of QoS Flow, according to the QoS indication information, the RAN can find out the corresponding specific parameters according to the received QoS strategy, and according to the parameters in the QoS strategy, the data of the user plane is used for corresponding processing to meet the quality requirement. The core network sends the data packet with QoS indication information to the RAN, which maps the QoS Flow to resources and radio bearers of the access network, e.g. the RAN decides that the QoS Flow maps to a certain data bearer DRB or establishes a new data bearer DRB for the QoS Flow. When a new DRB is established, the new DRB is determined by the RAN, and can be established after signaling of a core network is received, or after data of a user of the QoS Flow is received, according to QoS indication information contained in a packet header of the QoS Flow, the QoS indication information is combined with a default QoS policy and/or a pre-authentication QoS policy stored by the RAN, the RAN can learn a specific QoS requirement corresponding to the QoS Flow, and according to the QoS requirement, if the current DRB which is already established is suitable for bearing the data of the QoS requirement, the QoS Flow is transmitted through the DRB. If not, the RAN may decide to set up a new DRB with which to carry the QoS Flow.

In dual connectivity, both the primary and secondary base stations are RAN nodes, and QoS Flow may be split by the primary base station to the secondary base station in a dual connectivity manner, or vice versa. If the main base station and the auxiliary base station are both responsible for mapping QoS Flow to DRB, when the mapping relation determined by the main base station and the auxiliary base station is different, the current double-connection process needs to be modified correspondingly.

Disclosure of Invention

Therefore, the invention proposes a technical scheme how to establish dual connection when the main base station and the auxiliary base station determine that the mapping from QoS Flow to DRB is different. By the technical scheme provided by the invention, the resources of double connections can be correctly configured, the interaction of signaling is reduced, and the sending reliability of user data is improved.

According to a first aspect of the present invention, there is provided a method for connection establishment, comprising:

sending an auxiliary base station establishment request message to an auxiliary base station; and

and receiving an auxiliary base station establishment response message, wherein the auxiliary base station establishment response message comprises mapping information from the QoS Flow to the DRB.

In an exemplary embodiment, the secondary base station setup request message includes one or more of the following information:

the type of dual connectivity bearer;

identification information of QoS Flow;

An identification of a packet data unit Session, PDU, session to which the QoS Flow belongs;

quality requirement parameters corresponding to the QoS Flow;

an uplink data receiving address;

radio resource control, RRC, transparent container. In an exemplary embodiment, the auxiliary base station setup request message further includes: and the downlink data receiving address is distributed by the main base station and used for receiving downlink data from the auxiliary base station.

In an exemplary embodiment, the auxiliary base station setup response message further includes: the DRB receives the address of the downlink data on the Xn interface.

In an exemplary embodiment, the auxiliary base station setup request message further includes: an identification of the DRB corresponding to the QoS Flow that can be established on the secondary base station.

In an exemplary embodiment, the method further comprises:

according to the received auxiliary base station establishment response message, at least one of the following information is sent to the auxiliary base station:

the identification of the DRB determined by the auxiliary base station;

and the main base station distributes tunnel information for the DRB.

In an exemplary embodiment, the information is carried in a secondary base station reconfiguration complete message sent to the secondary base station.

According to a second aspect of the present invention, there is provided a method for connection establishment, comprising:

Receiving an auxiliary base station establishment request message from a main base station; and

and sending an auxiliary base station establishment response message to the main base station, wherein the auxiliary base station establishment response message comprises mapping information from the QoS Flow to the DRB.

the type of dual connectivity bearer;

identification information of QoS Flow;

quality requirement parameters corresponding to the QoS Flow;

an uplink data receiving address;

radio resource control, RRC, transparent container.

In an exemplary embodiment, the auxiliary base station setup request message further includes: and the downlink data receiving address is distributed by the main base station and used for receiving downlink data from the auxiliary base station.

In an exemplary embodiment, the method further comprises: receiving at least one of the following information sent by the main base station according to the auxiliary base station establishment response message:

The identification of the DRB determined by the auxiliary base station;

and the main base station distributes tunnel information for the DRB.

In an exemplary embodiment, the information is carried in an auxiliary base station reconfiguration complete message sent by the primary base station to the auxiliary base station.

According to a third aspect of the present invention, there is provided a method for requesting Secondary Cell Group (SCG) configuration, comprising:

an auxiliary base station modification request message for requesting SCG configuration information is sent to an auxiliary base station, wherein the auxiliary base station modification request message carries indication information and is used for indicating a main base station to obtain the SCG configuration information; and

and receiving an auxiliary base station modification response message sent by the auxiliary base station, wherein the auxiliary base station modification response message carries the SCG configuration information.

According to a fourth aspect of the present invention, there is provided a method for requesting Secondary Cell Group (SCG) configuration, comprising:

receiving an auxiliary base station modification request message for requesting SCG configuration information from a main base station, wherein the auxiliary base station modification request message carries indication information for indicating that the main base station needs to obtain the SCG configuration information; and

and sending an auxiliary base station modification response message to the main base station, wherein the auxiliary base station modification response message carries the SCG configuration information.

In an exemplary embodiment, after receiving the indication information, the auxiliary base station ignores the RRC transparent container carried in the auxiliary base station modification request message.

According to a fifth aspect of the present invention, there is provided a master base station comprising:

a communication interface configured for communication;

a processor; and

a memory storing computer executable instructions that, when executed by a processor, cause the master base station to perform the method previously described as being performed at the master base station.

According to a sixth aspect of the present invention, there is provided an assisting base station comprising:

a communication interface configured for communication;

a processor; and

a memory storing computer executable instructions that, when executed by a processor, cause the secondary base station to perform the aforementioned method performed at the secondary base station.

According to a seventh aspect of the present invention there is provided a computer readable medium having stored thereon instructions which, when executed by a processor, cause the processor to perform the aforementioned method.

Drawings

FIG. 1 schematically illustrates a 5G system architecture;

fig. 2 schematically illustrates a dual connection architecture;

fig. 3 schematically shows a user plane architecture of an SCG split bearer;

Fig. 4 schematically shows a flow chart of a method performed at a primary base station for establishing a dual connection according to an exemplary embodiment of the invention;

fig. 5 schematically shows a flow chart of a method performed at an assisting base station for establishing a dual connection according to an exemplary embodiment of the invention;

fig. 6 schematically shows a signaling flow diagram for establishing a dual connection according to exemplary embodiment 1 of the present invention;

fig. 7 schematically shows a signaling flow diagram for establishing a dual connection according to exemplary embodiment 2 of the present invention;

fig. 8 schematically shows a signaling flow diagram for establishing a dual connection according to exemplary embodiment 3 of the present invention;

fig. 9 schematically shows a flow chart of a method performed at a master base station for requesting an SCG configuration according to an exemplary embodiment of the invention;

fig. 10 schematically shows a flow chart of a method performed at a secondary base station for requesting SCG configuration according to an exemplary embodiment of the invention;

fig. 11 schematically shows a signaling flow diagram for requesting SCG configuration according to an exemplary embodiment of the present invention;

fig. 12 schematically shows a block diagram of a primary base station according to an exemplary embodiment of the present invention; and

Fig. 13 schematically shows a block diagram of a secondary base station according to an exemplary embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is further described in detail below with reference to the accompanying drawings. It should be noted that the following description is illustrative only and is not intended to limit the present disclosure. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one of ordinary skill in the art that: no such specific details need be employed to practice the present disclosure. In other instances, well-known circuits, materials, or methods have not been described in detail in order to avoid obscuring the present disclosure.

Throughout the specification, references to "one embodiment," "an embodiment," "one example," or "an example" mean: a particular feature, structure, or characteristic described in connection with the embodiment or example is included within at least one embodiment of the disclosure. Thus, the appearances of the phrases "in one embodiment," "in an embodiment," "one example," or "an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable combination and/or sub-combination in one or more embodiments or examples. Moreover, those of ordinary skill in the art will appreciate that the drawings are provided herein for illustrative purposes and that the drawings are not necessarily drawn to scale. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

The basic principle of the present invention is that the primary base station decides to establish a dual connection on the secondary base station, and the primary base station informs the secondary base station of the type of dual connection and the QoS Flow identification to be offloaded. For SCG split bearer, optionally, the primary base station may notify the DRB identifier determined by the primary base station (i.e. the DRB identifier corresponding to the QoS Flow to be split on the primary base station) and the primary base station receives tunnel information for the downlink on the Xn interface corresponding to the DRB.

And the auxiliary base station determines the mapping from QoS Flow to DRB, if the mapping determined by the auxiliary base station is the same as the mapping determined by the main base station, the auxiliary base station uses a downlink receiving tunnel on an Xn interface corresponding to the old DRB by adopting the main base station, and sends the split data to the tunnel and then the main base station sends the split data to the UE. If the mapping determined by the secondary base station is different from the mapping determined by the primary base station, the secondary base station informs the primary base station of the new DRB identification. Optionally, the auxiliary base station may instruct downlink receiving tunnel information on the Xn interface corresponding to the new DRB.

And the main base station allocates a corresponding downlink receiving tunnel on the Xn interface for the new DRB according to the identification of the new DRB, and informs the auxiliary base station of the downlink receiving tunnel on the Xn interface.

A method for establishing a dual connection, which may be performed at a master base station, according to an exemplary embodiment of the present disclosure will be described below with reference to fig. 4.

Fig. 4 schematically illustrates a flow diagram of a method 400 for establishing a dual connection that may be performed at a primary base station in accordance with an exemplary embodiment of the present disclosure. As shown in fig. 4, the method 400 may include steps S401 and S402.

In step S401, the primary base station may transmit a secondary base station setup request message to the secondary base station for requesting establishment of the DRB on the secondary base station.

The secondary base station setup request message may include one or more of the following information (e.g., exemplary embodiment 3, which will be described later with reference to fig. 8):

the type of dual connectivity bearer;

identification information of QoS Flow;

an identification of PDU Session to which QoS Flow belongs;

quality requirement parameters corresponding to the QoS Flow;

an uplink data receiving address;

RRC transparent container.

In an exemplary embodiment, the secondary base station setup request message may further include:

a downlink data reception address allocated by the primary base station for receiving downlink data from the secondary base station, an identification of a DRB corresponding to a QoS Flow established on the secondary base station (for example, exemplary embodiment 1 to be described later with reference to fig. 6); or (b)

A downlink data reception address allocated by the primary base station for receiving downlink data from the secondary base station (for example, exemplary embodiment 2 which will be described later with reference to fig. 7).

Identification of Data Radio Bearers (DRBs) that the secondary base station can configure. The identifiers of the DRBs are managed and allocated by the master base station in a unified manner, in the request message for establishing the auxiliary base station, the master base station informs the auxiliary base station of the identifiers of the DRBs currently available, and if the auxiliary base station needs to decide to establish a new DRB, one of the identifiers of the DRBs currently available needs to be selected as the identifier of the new DRB. Or the available ranges of the DRB identities of the auxiliary base station and the main base station are preconfigured, and the main base station or the auxiliary base station can only select the DRB identity for the data radio bearer from the available ranges.

In step S402, the primary base station may receive a secondary base station setup response message from the secondary base station, the secondary base station setup response message including QoS Flow to DRB mapping information.

In example embodiment 2, which will be described later with reference to fig. 7, the assisting base station setup response message may further include: the downlink data receiving address of the DRB on the Xn interface, which is one of the downlink data receiving addresses corresponding to the QoS Flow mapped to the DRB.

In exemplary embodiments 1 and 3, which will be described later with reference to fig. 6 and 8, respectively, the method 400 may further include: the primary base station may send at least one of the following information to the secondary base station according to the received secondary base station setup response message:

the identification of the DRB determined by the auxiliary base station;

and the main base station distributes tunnel information for the DRB.

This information may be carried in separate messages (e.g., signaling 603 and 803 to be described later) to be transmitted to the secondary base station, or in a secondary base station reconfiguration complete message (e.g., signaling 606 and 806 to be described later) to be transmitted to the secondary base station.

Accordingly, a method for establishing dual connectivity, which may be performed at an assisting base station, according to an exemplary embodiment of the present disclosure will be described with reference to fig. 5.

Fig. 5 schematically illustrates a flow diagram of a method 500 for establishing a dual connection that may be performed at a secondary base station in accordance with an exemplary embodiment of the present disclosure. As shown in fig. 5, method 500 may include steps S501 and S502.

In step S501, the secondary base station may receive a secondary base station setup request message from the primary base station for requesting establishment of a DRB on the secondary base station.

the type of dual connectivity bearer;

identification information of QoS Flow;

an identification of PDU Session to which QoS Flow belongs;

quality requirement parameters corresponding to the QoS Flow;

an uplink data receiving address;

RRC transparent container.

an identification of a DRB allocated by the primary base station other than a downlink data reception address for receiving downlink data from the secondary base station and corresponding to a QoS Flow that can be established on the secondary base station (for example, exemplary embodiment 1, which will be described later with reference to fig. 6); or (b)

In step S502, the secondary base station may transmit a secondary base station setup response message to the primary base station, the secondary base station setup response message including QoS Flow to DRB mapping information.

In exemplary embodiments 1 and 3, which will be described later with reference to fig. 6 and 8, respectively, the method 500 may further include: the auxiliary base station can receive at least one of the following information sent by the main base station according to the auxiliary base station establishment response message:

the identification of the DRB determined by the auxiliary base station;

and the main base station distributes tunnel information for the DRB.

This information may be carried in separate messages (e.g., signaling 603 and 803 to be described later) sent by the primary base station to the secondary base station, or in secondary base station reconfiguration complete messages (e.g., signaling 606 and 806 to be described later) sent by the primary base station to the secondary base station.

The signaling flows for establishing dual connections according to exemplary embodiments 1, 2 and 3 of the present invention will be described in detail below with reference to fig. 6, 7 and 8, respectively.

Example embodiment 1 describes that the primary base station notifies the secondary base station of information of QoS flows to be offloaded, DRB identifications (called old DRB identifications) to which these QoS flows are mapped, and downlink receipt reception tunnel information on an Xn interface to which the DRB corresponds. The secondary base station decides a mapping of QoS Flow to DRB and informs the primary base station of a new DRB identity, and if the new DRB identity is different from the old DRB identity, the primary base station allocates a downlink receipt receiving tunnel on the Xn interface for the new DRB identity and sends the tunnel information to the secondary base station. The tunnel information contains an IP address and a tunnel number TEID.

Referring to fig. 6, the signaling flow of exemplary embodiment 1 may include:

signaling 601, the primary base station sends a secondary base station setup request, which message is sent to the secondary base station.

The primary base station/secondary base station may be an LTE base station or a 5G base station gNB. It is assumed that both the primary base station and the secondary base station are connected to the 5G core network. Both the LTE base station and the 5G base station belong to the equipment of the 5G access network.

The primary base station decides to establish some QoS Flow on the secondary base station. These QoS flows may have been previously established on the source secondary base station, or on the primary base station, or on new data bearers configured by the core network. The auxiliary base station establishment request message contains an identifier of the QoS Flow, a transport layer address and a tunnel number TEID of the PDU Session where the QoS Flow is located for receiving uplink data in the core network, and the message also carries the capability information of the UE. The message also carries the connection type determined by the main base station, and the type of the double connection established on the auxiliary base station can divide the bearer, SCG bearer or auxiliary division bearer, and MCG division signaling.

Specifically, the secondary base station setup request message carries one or more of the following information:

■ The type of the dual connection bearer may be set to a split bearer type, an SCG bearer type, or an SCG split bearer type.

■ The QoS Flow identification information may be, for example, an identification of the QoS Flow to be established on the secondary base station. The primary base station indicates which QoS flows may be established on the secondary base station under the bearer type described above. The identifier of the QoS Flow is sent to the main base station by the core network, and the core network sends the quality requirement corresponding to the identifier of the QoS Flow and the identifier of the QoS Flow to the main base station through the initial context establishment process, the initial context modification process, or the data connection process.

■ The identity of the PDU Session (PDU Session ID) to which the QoS Flow belongs.

■ Quality requirement parameters of QoS Flow. The information is the quality requirement corresponding to the QoS Flow, and can comprise standard 5G quality requirement indication 5QI, priority ARP, uplink/downlink maximum rate of GBR service and uplink/downlink guaranteed rate of GBR service. Or contains specific parameters of quality requirements, such as information of resource type, priority level, data delay target, error rate, etc. The identifier of the QoS Flow and the corresponding quality requirement parameter are transmitted from the core network to the primary base station, and the primary base station may directly send the value sent from the core network to the secondary base station, or determine a new value according to the value sent from the core network and send the new value to the secondary base station.

■ Identification of DRBs. The DRB identifier is the identifier of the data radio bearer corresponding to the QoS Flow established on the secondary base station, and the secondary base station can know which QoS flows are mapped to the same DRB on the primary base station through the QoS Flow identifier and the DRB identifier.

■ The uplink data receiving address is an uplink data receiving transport layer address and a tunnel identifier (i.e. GTP TEID) allocated by the main base station if the uplink data receiving address is a split bearer. If the uplink data receiving address is the SCG bearer and the SCG split bearer, the uplink data receiving transmission layer address and the tunnel identifier allocated by the core network.

■ The downlink data receiving address, if it is an SCG split bearer, the message also carries the downlink data receiving transport layer address and the tunnel identifier. The downlink data reception address is an address allocated by the primary base station for receiving downlink data from the secondary base station. The main base station allocates a downlink data receiving address of an Xn interface to each DRB.

■ The RRC transparent container may contain a measurement report of the UE. The identity of the MCG split SRB and/or the configuration information of the corresponding RLC, MAC etc. layers may also be included in the RRC transparent container.

■ Identification of Data Radio Bearers (DRBs) that the secondary base station can configure. The identifiers of the DRBs are managed and allocated by the master base station in a unified manner, in the request message for establishing the auxiliary base station, the master base station informs the auxiliary base station of the identifiers of the DRBs currently available, and if the auxiliary base station needs to decide to establish a new DRB, one of the identifiers of the DRBs currently available needs to be selected as the identifier of the new DRB. Or the available ranges of the DRB identities of the auxiliary base station and the main base station are preconfigured, and the main base station or the auxiliary base station can only select the DRB identity for the data radio bearer from the available ranges. This information may also be contained in the RRC transparent container.

The following table describes what the secondary base station setup request message contains when the setup bearer is an SCG split bearer.

Signaling 602, the secondary base station sends a secondary base station setup response message to the primary base station.

The secondary base station setup response message contains one or more of the following information:

■ And assisting the identification of QoS Flow accepted by the base station. For quality of service QoS flows that the primary base station decides to offload to the secondary base station, the secondary base station may decide to accept certain QoS flows and reject certain QoS flows. In the auxiliary base station establishment response message, the auxiliary base station informs the main base station of which QoS is accepted and which QoS flows are rejected.

■ And the radio bearer DRB identification established by the auxiliary base station. The auxiliary base station establishment response message also needs to carry the DRB identifier corresponding to the QoS Flow. If in the secondary base station setup request message the primary base station decides that the type of dual connection to be set up is SCG split bearer, the primary base station decides which QoS flows need to be offloaded onto the secondary base station and decides the type of bearer to be set up, the secondary base station can decide the mapping of QoS flows to DRBs. If the QoS flows for offloading were previously established on the primary base station, the primary base station receives QoS Flow data from the core network, sends the data to the UE through the DRBs on the primary base station, the primary base station decides the QoS Flow to DRBs mapping, then the primary base station decides to offload these QoS flows to the secondary base station, for SCG split bearers, the secondary base station can decide the QoS Flow to DRBs mapping, the secondary base station receives QoS Flow data from the core network, maps the data to DRBs, and then splits the data into two paths, one path of data is sent to the UE by the secondary base station, the other path is sent to the primary base station by the secondary base station, and the primary base station is sending to the UE. The secondary base station determined mapping may be different from the primary base station determined mapping. On the Xn interface, for SCG split bearer, one path of the SCG split bearer is sent to the UE through the primary base station, so that the primary base station needs to allocate an Xn downlink data receiving tunnel number to the data, the tunnel number is specific to a DRB, the secondary base station needs to notify the primary base station of the mapping from qosf low to DRB determined by itself, and the secondary base station establishes the DRB identifier and the QoS Flow identifier carried in the response message through the secondary base station, so that the secondary base station notifies the primary base station of the mapping relationship.

■ The RRC transparent container may contain configuration information of the secondary base station to the UE. The primary base station forwards the RRC transparent container to the UE in signaling 604.

Signaling 603, the primary base station sends a modification message to the secondary base station.

The modification message contains one or more of the following information:

■ Radio bearer DRB identification. The identity is the DRB identity determined by the secondary base station and is sent to the primary base station in signaling 602.

■ Tunnel information. The main base station distributes tunnel information for the DRB, wherein the tunnel information comprises an IP address and a tunnel number TEID. On the Xn interface, for SCG split bearer, the primary base station needs to assign an Xn downlink data receive tunnel number to the data, which is for a DRB.

Or the two information are carried by the secondary base station reconfiguration complete message through 606 and sent to the secondary base station by the primary base station. Thus, no messages in signaling 603 are required. The advantage of the message defining the signalling 603 is that data can be sent from the secondary base station to the primary base station and thus to the UE as soon as possible.

Signaling 604, the primary base station sends an RRC configuration request message to the UE.

The primary base station does not parse the RRC container sent by the secondary base station and forwards the RRC container to the UE. The primary base station may add its own configuration information for the UE and send it to the UE along with the configuration information for the secondary base station.

Signaling 605, the ue sends an RRC configuration complete message to the master base station.

And after the UE is configured successfully, sending a response message to the main base station. The response message may include both a response to the primary base station configuration information and a response to the secondary base station configuration information. The UE also needs to perform a random access procedure with the new secondary base station and synchronize with the new secondary base station, if necessary. After synchronization, the assisting base station may begin transmitting data to the UE.

Signaling 606, the primary base station sends a secondary base station reconfiguration complete message to the secondary base station.

The main base station informs the auxiliary base station of the successful configuration information of the UE side. Because the UE sends the acknowledgement message to the primary base station, the primary base station needs to forward the acknowledgement message to the secondary base station. If the primary base station cannot resolve the response of the UE to the configuration information of the secondary base station, the primary base station may also forward the response of the UE to the configuration information of the secondary base station to the secondary base station in the form of an RRC container.

If there is no message in signaling 603, the secondary base station reconfiguration complete message may also contain the following information:

Example embodiment 2 describes that the primary base station notifies the information of QoS flows to be offloaded, and the downstream receipt on the Xn interface corresponding to the QoS flows receives tunnel information to the secondary base station. The auxiliary base station decides the mapping from QoS Flow to DRB, and sends the new DRB identification and the downlink receipt receiving tunnel information on Xn interface corresponding to the DRB identification to the main base station. The tunnel information contains an IP address and a tunnel number TEID.

Referring to fig. 7, the signaling flow of exemplary embodiment 2 may include:

signaling 701, the primary base station sends a secondary base station setup request, which message is sent to the secondary base station.

The primary base station decides to establish some QoS Flow at the secondary base station. These QoS flows may have been previously established on the source secondary base station, or on the primary base station, or on new data bearers configured by the core network. The auxiliary base station establishment request message contains an identifier of the QoS Flow, a transport layer address and a tunnel number TEID of the PDU Session where the QoS Flow is located for receiving uplink data in the core network, and the message also carries the capability information of the UE. The message also carries the connection type determined by the main base station, and the type of the double connection established on the auxiliary base station can divide the bearer, SCG bearer or auxiliary division bearer, and MCG division signaling.

■ The QoS Flow identification information may be, for example, an identification of the QoS Flow to be established on the secondary base station. The primary base station indicates which QoS flows are established on the secondary base station under the bearer type described above. The identifier of the QoS Flow is sent to the main base station by the core network, and the core network sends the quality requirement corresponding to the identifier of the QoS Flow and the identifier of the QoS Flow to the main base station through the initial context establishment process, the initial context modification process, or the data connection process.

■ The downlink data receiving address, if it is an SCG split bearer, the message also carries the downlink data receiving transport layer address and the tunnel identifier. The downlink data reception address is an address allocated by the primary base station for receiving downlink data from the secondary base station. The main base station allocates a downlink data receiving address of an Xn interface to each QoS Flow. Or the main base station allocates a plurality of downlink data receiving addresses, the downlink data receiving address list is carried in the message and is sent to the auxiliary base station, if the auxiliary base station decides to use different mapping, a new DRB is established, the auxiliary base station selects one downlink data receiving address from the list as the downlink data receiving address of the Xn interface of the SCG split, and sends the downlink data to the address.

■ Identification of Data Radio Bearers (DRBs) that the secondary base station can configure. The identifiers of the DRBs are managed and allocated by the master base station in a unified manner, in the request message for establishing the auxiliary base station, the master base station informs the auxiliary base station of the identifiers of the DRBs currently available, and if the auxiliary base station needs to decide to establish a new DRB, one of the identifiers of the DRBs currently available needs to be selected as the identifier of the new DRB. This information may also be contained in the RRC transparent container.

Signaling 702, the secondary base station sends a secondary base station setup response message to the primary base station.

■ And assisting the identification of QoS Flow accepted by the base station. For mass Flow QoS flows that the primary base station decides to offload to the secondary base station, the secondary base station may decide to accept certain QoS flows and reject certain QoS flows. In the auxiliary base station establishment response message, the auxiliary base station informs the main base station of which QoS is accepted and which QoS flows are rejected.

■ And the radio bearer DRB identification established by the auxiliary base station. The auxiliary base station establishment response message also needs to carry the DRB identifier corresponding to the QoS Flow. If in the secondary base station setup request message the primary base station decides that the type of dual connection to be set up is SCG split bearer, the primary base station decides which QoS flows need to be offloaded onto the secondary base station and decides the type of bearer to be set up, the secondary base station can decide the mapping of QoS flows to DRBs. If the QoS flows for offloading were previously established on the primary base station, the primary base station receives QoS Flow data from the core network, sends the data to the UE through the DRBs on the primary base station, the primary base station decides the QoS Flow to DRBs mapping, then the primary base station decides to offload these QoS flows to the secondary base station, for SCG split bearers, the secondary base station can decide the QoS Flow to DRBs mapping, the secondary base station receives QoS Flow data from the core network, maps the data to DRBs, and then splits the data into two paths, one path of data is sent to the UE by the secondary base station, the other path is sent to the primary base station by the secondary base station, and the primary base station is sending to the UE. The secondary base station determined mapping may be different from the primary base station determined mapping. On the Xn interface, for SCG split bearer, one path is sent to the UE through the primary base station, so that the primary base station needs to allocate an Xn downlink data receiving tunnel number to the data, where the tunnel number is for a DRB, the secondary base station needs to notify the primary base station of the mapping from the QoS Flow to the DRB determined by itself, and the secondary base station establishes the DRB identifier and the QoS Flow identifier carried in the response message through the secondary base station, so that the secondary base station notifies the primary base station of the mapping relationship.

■ Xn downlink data receive address, multiple QoS flows can be mapped onto one DRB, which is determined by the assisting base station. For each DRB, xn corresponds to a downstream data reception address, which is the address on the primary base station to which the secondary base station sends the data. In the message of step 501, the downlink data receiving address allocated by the primary base station for each of the divided QoS flows is included, the secondary base station determines the mapping from the QoS Flow to the DRB, and selects one of the downlink data receiving addresses corresponding to the QoS Flow as the downlink data receiving address of the DRB on Xn.

■ The RRC transparent container may contain configuration information of the secondary base station to the UE. The master base station forwards the RRC transparent container to the UE in step 404.

Signaling 703, the primary base station sends an RRC configuration request message to the UE.

Signaling 704, the ue sends an RRC configuration complete message to the primary base station.

Signaling 705, the primary base station sends a secondary base station reconfiguration complete message to the secondary base station.

Example embodiment 3 describes that the primary base station notifies the information of QoS flows to be offloaded, the secondary base station decides on the mapping of QoS flows to DRBs, and transmits a new DRB identity and the downlink receipt reception tunnel information on the Xn interface corresponding to the DRB identity to the primary base station. The tunnel information contains an IP address and a tunnel number TEID.

Referring to fig. 8, the signaling flow of exemplary embodiment 3 may include:

signaling 801, the primary base station sends a secondary base station setup request, which message is sent to the secondary base station.

The primary base station decides to establish some QoS Flow at the secondary base station. These QoS flows may have been previously established on the source secondary base station, or on the primary base station, or on new data bearers configured by the core network. The auxiliary base station establishment request message contains an identifier of the QoS Flow, a transport layer address of the PDU Session core network where the QoS Flow is located for receiving uplink data and a tunnel number TEID, and the message also carries the capability information of the UE. The message also carries the connection type determined by the main base station, and the type of the double connection established on the auxiliary base station can divide the bearer, SCG bearer or auxiliary division bearer, and MCG division signaling.

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Signaling 802, the secondary base station sends a secondary base station setup response message to the primary base station.

■ The RRC transparent container may contain configuration information of the secondary base station to the UE. The primary base station forwards the RRC transparent container to the UE in signaling 804.

Signaling 803, the primary base station sends a modification message to the secondary base station.

The modification message contains one or more of the following information:

■ Radio bearer DRB identification. The identity is the DRB identity determined by the secondary base station and is sent to the primary base station in step 402.

Or the two information are carried by the reconfiguration complete message of the auxiliary base station through 806, and sent to the auxiliary base station by the main base station. Thus, no messages in signaling 803 are required. The advantage of the message defining 803 step is that data can be sent from the secondary base station to the primary base station and thus to the UE as soon as possible.

Signaling 804, the primary base station sends an RRC configuration request message to the UE.

Signaling 805, the ue sends an RRC configuration complete message to the primary base station.

Signaling 806, the primary base station sends a secondary base station reconfiguration complete message to the secondary base station.

If there is no message in signaling 803, the secondary base station reconfiguration complete message may also contain the following information:

■ Radio bearer DRB identification. The identity is the DRB identity determined by the secondary base station and is sent to the primary base station in signaling 802.

A method for requesting SCG configuration, which may be performed at a master base station, according to an exemplary embodiment of the present disclosure will be described below with reference to fig. 9.

Fig. 9 schematically illustrates a flow diagram of a method 900 for requesting SCG configuration that may be performed at a master base station according to an exemplary embodiment of the present disclosure. As shown in fig. 9, the method 900 may include steps S901 and S902.

In step S901, the primary base station may send, to the secondary base station, a secondary base station modification request message for requesting SCG configuration information, where the secondary base station modification request message carries indication information, where the indication information is used to indicate that the primary base station needs to obtain the SCG configuration information.

In step S902, the primary base station may receive a secondary base station modification response message sent by the secondary base station, where the secondary base station modification response message carries the SCG configuration information.

A method for requesting SCG configuration, which may be performed at the secondary base station, according to an exemplary embodiment of the present disclosure will be described below with reference to fig. 10.

Fig. 10 schematically illustrates a flow chart of a method 1000 for requesting SCG configuration that may be performed at a secondary base station according to an exemplary embodiment of the present disclosure. As shown in fig. 10, the method 1000 may include steps S1001 and S1002.

In step S1001, the auxiliary base station may receive an auxiliary base station modification request message for requesting SCG configuration information from the primary base station, where the auxiliary base station modification request message carries indication information, and is used to indicate that the primary base station needs to obtain the SCG configuration information; and

in step S1002, the secondary base station may send a secondary base station modification response message to the primary base station, where the secondary base station modification response message carries the SCG configuration information.

After receiving the indication information, the auxiliary base station may ignore the RRC transparent container carried in the auxiliary base station modification request message.

The signaling flow for requesting SCG configuration according to an exemplary embodiment of the present invention will be described in detail below with reference to fig. 11, respectively.

This exemplary embodiment describes a method for a master base station to request SCG configuration. The primary base station decides to switch the secondary base station and switches the UE from the source secondary base station to the destination secondary base station. Before the handover, the primary base station needs to obtain the latest secondary cell group configuration information from the secondary base station. The steps of the message are depicted in fig. 11.

Signaling 1101: the primary base station sends a secondary base station modification request message to the secondary base station.

The message carries an identification XnAP ID on the Xn interface allocated by the master base station for the UE.

The assisting base station assigns an identification XnAP ID on the Xn interface to the UE.

The message carries an RRC transparent container. The transparent container contains configuration information of the MCG and capability configuration information of the UE. Normally, if the RRC transparent container is included, the secondary base station needs to parse the RRC transparent container, and the secondary base station may modify the configuration information of the SCG according to the content included in the RRC transparent container.

The secondary base station modification request message also carries indication information indicating that the primary base station needs to obtain the latest configuration information of the SCG on the secondary base station. If the auxiliary base station modification request message contains an RRC transparent container, the indication information also indicates that the auxiliary base station needs to ignore the RRC transparent container carried in the auxiliary base station modification request message. The indication information may be carried in a message, for example, defining "the SCG configuration information need to be obtained" or "the action indication" which is used to indicate the purpose of the MeNB to initiate the secondary base station modification request message, and in this embodiment, the action indication may be set to obtain the SCG configuration information. Or the specific reason is indicated in the information element "reason" existing in the secondary base station modification request message because the SCG configuration information is to be acquired. The auxiliary base station receives the indication information and needs to send the latest configuration information of the SCG on the auxiliary base station to the main base station, optionally, if the auxiliary base station modification request message contains an RRC transparent container, the auxiliary base station needs to ignore the RRC transparent container contained in the auxiliary base station modification request message.

Signaling 1102: the secondary base station sends a secondary base station modification response message to the primary base station.

If the message in signaling 1101 carries an indication that the primary base station needs to obtain the configuration information of the SCG on the latest secondary base station, the message in signaling 1102 carries an RRC transparent container. In the RRC transparent container is the latest SCG configuration information. The SCG configuration information may be configuration information of a complete SCG for the UE. If the message in the signaling 1101 carries the RRC transparent container and the indication information that the primary base station needs to obtain the configuration information of the SCG on the secondary base station that is up to date, the secondary base station ignores the RRC transparent container that the base station modification request message contains.

Signaling 1103: the primary base station sends a secondary base station establishment request message to the destination secondary base station. The message carries 1102 configuration information of the SCG obtained from the source assisting base station.

Signaling 1104: the destination auxiliary base station sends an auxiliary base station establishment response message to the main base station. The message carries configuration information of the SCG of the target base station to the UE. The configuration information refers to the configuration information of the SCG of the UE by the source base station carried by the message in step 1103, and the destination base station generates the latest SCG configuration information and sends the information to the UE through the master base station.

Signaling 1105: the master base station sends a secondary base station release request to the source secondary base station. The source assisting base station deletes the context of the UE.

Signaling 1106: the primary base station sends a secondary base station reconfiguration complete message to the secondary base station. The secondary base station may begin transmitting data.

The structure of the master base station according to an exemplary embodiment of the present invention will be described below with reference to fig. 12. Fig. 12 schematically shows a block diagram of a master base station performing a method for establishing a dual connection according to an exemplary embodiment of the present invention. The master base station 1200 may be used to perform the method 400 described with reference to fig. 4 or the method 900 described with reference to fig. 9. For simplicity, only the schematic structure of the master base station according to an exemplary embodiment of the present disclosure will be described herein, and details that have been detailed in the method 400 as previously described with reference to fig. 4 or the method 900 as described with reference to fig. 9 will be omitted.

As shown in fig. 12, the master base station 1200 includes a communication interface 1201 for external communication; a processing unit or processor 1202, which processor 1202 may be a single unit or a combination of units for performing the different steps of the method; memory 1203 has stored therein computer executable instructions that, when executed by processor 902, cause master base station 1200 to perform method 400 or method 900.

The instructions, when executed by the processor 1202, cause the master base station 1200 to perform the exemplary embodiment of the method 400, the instructions cause the master base station 1200 to:

sending an auxiliary base station establishment request message to an auxiliary base station, wherein the auxiliary base station establishment request message is used for requesting to establish the DRB on the auxiliary base station; and

and receiving an auxiliary base station establishment response message, wherein the auxiliary base station establishment response message comprises mapping information from QoS Flow to DRB.

In an exemplary embodiment, the secondary base station setup request message may include one or more of the following information (e.g., exemplary embodiment 3 described with reference to fig. 8):

the type of dual connectivity bearer;

identification information of QoS Flow;

an identification of PDU Session to which QoS Flow belongs;

quality requirement parameters corresponding to the QoS Flow;

an uplink data receiving address;

RRC transparent container.

an identification of a DRB corresponding to a QoS Flow that can be established on the secondary base station, which is allocated by the primary base station, in addition to a downlink data reception address for receiving downlink data from the secondary base station, and which is decided by the primary base station (for example, exemplary embodiment 1 described with reference to fig. 6); or (b)

A downlink data reception address allocated by the primary base station for receiving downlink data from the secondary base station (for example, exemplary embodiment 2 described with reference to fig. 7)

As described above, in the exemplary embodiment 2 described with reference to fig. 7, the auxiliary base station setup response message may further include: a downlink data receiving address of DRB on Xn interface, which is one of downlink data receiving addresses corresponding to QoS Flow mapped to said DRB

As previously described, in exemplary embodiments 1 and 3 described with reference to fig. 6 and 8, respectively, the instructions, when executed by the processor 1202, cause the master base station 1200 to perform the following: according to the received auxiliary base station establishment response message, at least one of the following information is sent to the auxiliary base station:

the identification of the DRB determined by the auxiliary base station;

and the main base station distributes tunnel information for the DRB.

This information may be carried in separate messages (e.g., signaling 603 and 803) for transmission to the secondary base station or in secondary base station reconfiguration complete messages (e.g., signaling 606 and 806) for transmission to the secondary base station.

Optionally, the instructions, when executed by the processor 1202, cause the master base station 1200 to perform the exemplary embodiment of the method 900, the instructions cause the master base station 1200 to:

The structure of the secondary base station according to an exemplary embodiment of the present invention will be described below with reference to fig. 13. Fig. 13 schematically shows a block diagram of an assisting base station performing a method for establishing a dual connection according to an exemplary embodiment of the present invention. Secondary base station 1300 may be used to perform method 500 described with reference to fig. 5 or method 1000 described with reference to fig. 10. For simplicity, only the schematic structure of the master base station according to an exemplary embodiment of the present disclosure will be described herein, and details that have been detailed in the method 500 as previously described with reference to fig. 5 or the method 1000 as described with reference to fig. 10 will be omitted.

As shown in fig. 13, the assisting base station 1300 includes a communication interface 1301 for external communication; a processing unit or processor 1302, which processor 1302 may be a single unit or a combination of units for performing the different steps of the method; memory 1303, having stored therein computer executable instructions that, when executed by processor 1302, cause secondary base station 1300 to perform method 500 or method 1000.

The instructions, when executed by the processor 1302, cause the secondary base station 1300 to perform the exemplary embodiment of the method 500, cause the secondary base station 1300 to:

receiving an auxiliary base station establishment request message from the main base station for requesting establishment of the DRB on the auxiliary base station; and

and sending an auxiliary base station establishment response message to the main base station, wherein the auxiliary base station establishment response message comprises mapping information from QoS Flow to DRB.

the type of dual connectivity bearer;

identification information of QoS Flow;

an identification of PDU Session to which QoS Flow belongs;

quality requirement parameters corresponding to the QoS Flow;

an uplink data receiving address;

RRC transparent container.

As described above, in the exemplary embodiment 2 described with reference to fig. 7, the auxiliary base station setup response message may further include: the downlink data receiving address of the DRB on the Xn interface, which is one of the downlink data receiving addresses corresponding to the QoS Flow mapped to the DRB.

As previously described, in exemplary embodiments 1 and 3 described with reference to fig. 6 and 8, respectively, the instructions, when executed by processor 1302, cause assisting base station 1300 to perform the following procedure: receiving from the primary base station at least one of the following information sent to the secondary base station in accordance with the secondary base station setup response message:

the identification of the DRB determined by the auxiliary base station;

and the main base station distributes tunnel information for the DRB.

This information may be carried in separate messages (e.g., signaling 603 and 803) sent by the primary base station to the secondary base station or in secondary base station reconfiguration complete messages (e.g., signaling 606 and 806) sent by the primary base station to the secondary base station.

Optionally, the instructions, when executed by the processor 1302, cause the secondary base station 1300 to perform the exemplary embodiment of the method 1000, the instructions cause the secondary base station 1300 to:

The program running on the apparatus according to the present invention may be a program for causing a computer to realize the functions of the embodiments of the present invention by controlling a Central Processing Unit (CPU). The program or information processed by the program may be temporarily stored in a volatile store such as a random access memory RAM, a Hard Disk Drive (HDD), a nonvolatile store such as a flash memory, or other memory system.

A program for realizing the functions of the embodiments of the present invention may be recorded on a computer-readable recording medium. The corresponding functions can be realized by causing a computer system to read programs recorded on the recording medium and execute the programs. The term "computer system" as used herein may be a computer system embedded in the device and may include an operating system or hardware (e.g., peripheral devices). The "computer-readable recording medium" may be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a recording medium in which a program is stored dynamically at a short time, or any other recording medium readable by a computer.

The various features or functional modules of the apparatus used in the embodiments described above may be implemented or performed by circuitry (e.g., single-chip or multi-chip integrated circuits). Circuits designed to perform the functions described herein may include a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The circuit may be a digital circuit or an analog circuit. Where new integrated circuit technologies are presented as an alternative to existing integrated circuits due to advances in semiconductor technology, one or more embodiments of the present invention may also be implemented using these new integrated circuit technologies.

As above, the embodiments of the present invention have been described in detail with reference to the accompanying drawings. However, the specific structure is not limited to the above-described embodiment, and the present invention also includes any design modification without departing from the gist of the present invention. In addition, various modifications can be made to the present invention within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in the different embodiments are also included in the technical scope of the present invention. Further, the components having the same effects described in the above embodiments may be replaced with each other.

The foregoing description is only of the preferred embodiments of the present application and is presented as a description of the principles of the technology being utilized. It will be appreciated by persons skilled in the art that the scope of the invention referred to in this application is not limited to the specific combinations of features described above, but it is intended to cover other embodiments in which any combination of features described above or equivalents thereof is possible without departing from the spirit of the invention. Such as the above-described features and technical features having similar functions (but not limited to) disclosed in the present application are replaced with each other.

Claims

1. A method performed by a primary base station in a wireless communication system, comprising:

transmitting a first message for requesting the auxiliary base station to allocate resources for a dual connectivity operation to the auxiliary base station, the first message including a quality of service (QoS) Flow Identification (ID) and an available DRB Identification (ID);

after the first message is sent, a second message is received from an auxiliary base station, wherein the second message comprises the QoS Flow ID and a DRB ID corresponding to the QoS Flow ID, and an RRC container comprising configuration information of the auxiliary base station to UE.

2. The method of claim 1, wherein the available DRB IDs indicate a list of DRB IDs that the secondary base station can use.

3. The method of claim 1, wherein the first message further comprises one or more of the following information:

an ID of a QoS Flow associated with the resource;

an ID of a packet data unit Session PDU Session associated with the resource;

and QoS parameters corresponding to the QoS Flow.

4. The method of claim 1, further comprising:

after receiving the second message, sending a third message to the secondary base station, wherein the third message comprises tunnel information corresponding to the DRB ID, and the tunnel information comprises an Internet Protocol (IP) address and a Tunnel Endpoint Identification (TEID).

5. A method performed by an assisting base station in a wireless communication system, comprising:

receiving a first message from a primary base station requesting a secondary base station to allocate resources for a dual connectivity operation, the first message including a quality of service, qoS, flow identification, ID, and an available DRB identification, ID;

after receiving the first message, sending a second message to the primary base station, wherein the second message comprises the QoS Flow ID and a DRB ID corresponding to the QoS Flow ID, and an RRC container comprising configuration information of the auxiliary base station to UE.

6. The method of claim 5 wherein the available DRB IDs indicate a list of DRB IDs that the secondary base station can use.

7. The method of claim 5, wherein the first message further comprises one or more of the following information:

an ID of a QoS Flow associated with the resource;

an ID of a packet data unit Session PDU Session associated with the resource;

and QoS parameters corresponding to the QoS Flow.

8. The method of claim 5, further comprising:

after sending the second message, receiving a third message from the primary base station, the third message comprising tunnel information corresponding to the DRB ID, the tunnel information comprising an internet protocol IP address and a tunnel endpoint identification TEID.

9. A master base station comprising:

a communication interface configured for communication;

a processor; and

a memory storing computer executable instructions that, when executed by a processor, cause the master base station to:

10. The primary base station of claim 9, wherein the available DRB IDs indicate a list of DRB IDs that can be used by the secondary base station.

11. The master base station of claim 9, wherein the first message further comprises one or more of the following information:

an ID of a QoS Flow associated with the resource;

an ID of a packet data unit Session PDU Session associated with the resource;

and QoS parameters corresponding to the QoS Flow.

12. The master base station of claim 9, wherein the instructions, when executed by the processor, further cause the master base station to:

13. An assisting base station comprising:

a communication interface configured for communication;

a processor; and

a memory storing computer executable instructions that, when executed by a processor, cause the secondary base station to:

14. The assisting base station of claim 13, wherein the available DRB IDs indicate a list of DRB IDs that the assisting base station can use.

15. The assisting base station of claim 13, wherein the first message further comprises one or more of the following information:

an ID of a QoS Flow associated with the resource;

an ID of a packet data unit Session PDU Session associated with the resource;

and QoS parameters corresponding to the QoS Flow.

16. The assisting base station of claim 13, wherein the instructions, when executed by a processor, further cause the assisting base station to:

17. A computer readable medium having stored thereon instructions which, when executed by a processor, cause the processor to perform the method of any of claims 1 to 4.

18. A computer readable medium having stored thereon instructions which, when executed by a processor, cause the processor to perform the method of any of claims 5 to 8.