KR101602999B1

KR101602999B1 - Methods for configuring a dual connection in mobile communication networks and apparatuses thereof

Info

Publication number: KR101602999B1
Application number: KR1020130161875A
Authority: KR
Inventors: 홍성표; 최우진
Original assignee: 주식회사 케이티
Priority date: 2013-06-13
Filing date: 2013-12-23
Publication date: 2016-03-11
Also published as: KR20140145524A; WO2015064972A1; KR20140145527A

Abstract

The present invention relates to a process for establishing a dual connection with a plurality of base stations, and more particularly, to a process in which a terminal fails to perform additional radio resource configuration processing for using radio resources provided by different base stations &Lt; / RTI > Specifically, the present invention provides a method of establishing a dual connection with a plurality of base stations, the method comprising the steps of: receiving a first signal including information for further configuring a radio resource from a first base station via a second base station; Attempting a random access with the second base station and an additional radio resource configuration via the second base station based on the first signal and a random access with the second base station or with the additional radio resource configuration via the second base station, And transmitting a second signal including additional radio resource configuration failure indication information to the first base station.

Description

TECHNICAL FIELD The present invention relates to a method for configuring a dual connection in a mobile communication network,

The present invention relates to a process for establishing a dual connection with a plurality of base stations, and more particularly, to a process in which a terminal fails to perform additional radio resource configuration processing for using radio resources provided by different base stations &Lt; / RTI >

As communications systems evolved, consumers, such as businesses and individuals, used a wide variety of wireless terminals.

In a mobile communication system such as LTE (Long Term Evolution) and LTE-Advanced of the current 3GPP series, there is a demand for a high-speed, large-capacity communication system capable of transmitting and receiving various data such as video and wireless data beyond a voice-oriented service.

For such a high-speed, large-capacity communication system, a technique for increasing the capacity of a terminal using a small cell is required. That is, there is a need for a technology capable of processing high-speed and large-capacity data by providing at least two base stations with radio resources to one terminal.

Meanwhile, a procedure for adding a radio resource of another base station and starting communication is required in order for a terminal performing communication through one base station to construct additional radio resources.

In addition, when a problem occurs in a process of adding a radio resource of another base station or starting communication using an added radio resource, a processing method for the same and a specific procedure for quick communication recovery of the terminal are required.

According to the above-described request, an additional radio resource configuration procedure is required for the terminal performing communication with the first base station to further use the radio resources of the second base station.

Further, there is a problem that unnecessary connection release operation occurs even though the terminal can communicate through the first base station in the case of failure in the configuration of the additional radio resource through the second base station or the random access with the second base station.

According to an aspect of the present invention, there is provided a method of establishing a dual connection with a plurality of base stations, the method comprising: receiving a first signal including information for further configuring a radio resource from a first base station through a second base station; Receiving additional radio resource configuration via the second base station based on the first signal and attempting random access with the second base station and random access with the second base station or additional radio resource configuration via the second base station And if so, transmitting a second signal comprising additional radio resource configuration failure indication information to the first base station.

According to another aspect of the present invention, there is provided a method of controlling a dual link configuration of a terminal in a first base station, the method comprising: generating a first signal including information for further configuring a radio resource via a second base station; Layer signaling, and receiving a second signal from the terminal, the second signal including additional radio resource configuration failure indication information.

The present invention also provides a wireless communication system including a receiving unit for receiving a first signal including information for additionally configuring a radio resource from a first base station through a second base station, When the second base station fails to randomly access to the second base station or the additional radio resource configuration through the control unit attempting random access with the second base station, a second signal including additional radio resource configuration failure indication information to the first base station And a transmission unit for transmitting the terminal information.

According to another aspect of the present invention, there is provided a wireless communication system including a controller for generating a first signal including information for additionally configuring a radio resource through a second base station, a transmitter for transmitting the first signal through an upper layer signaling, And a receiver for receiving a second signal including information.

According to the present invention described above, there is an effect of providing a specific procedure for the terminal to perform additional radio resource configuration through the second base station.

In addition, according to the present invention, when the terminal fails to construct an additional radio resource through the second base station, communication can be performed using radio resources through the existing first base station.

Also, even if the additional radio resource configuration through the second base station fails, the unnecessary process of releasing the existing radio resources and attempting a new connection is greatly reduced.

1 is a diagram illustrating an example of a network configuration to which the present invention can be applied.
2 is a diagram showing another example of a network configuration to which the present invention can be applied.
3 is a diagram illustrating another example of a network configuration to which the present invention can be applied.
FIG. 4 is a diagram illustrating exemplary operations of a terminal and a base station that additionally configure a radio resource of a second base station according to an embodiment of the present invention.
5 is a diagram illustrating an example of a bearer-separated additional radio resource configuration for further configuring a radio resource of a second base station according to another embodiment of the present invention.
FIG. 6 is a diagram illustrating an example of a configuration of a bearer non-separated additional radio resource for further configuring a radio resource of a second base station according to another embodiment of the present invention.
FIG. 7 is a diagram illustrating another example of an additional radio resource configuration in which a bearer is not separated, which further configures a radio resource of a second base station according to another embodiment of the present invention.
FIG. 8 is a diagram illustrating exemplary operations of a UE and a base station in the case of an additional radio resource configuration failure according to another embodiment of the present invention.
9 is a diagram illustrating an example of additional radio resource configuration indication information that may be included in a first signal according to another embodiment of the present invention.
10 is a diagram illustrating another example of additional radio resource configuration indication information that may be included in a first signal according to another embodiment of the present invention.
11 is a diagram illustrating another example of additional radio resource configuration indication information that may be included in a first signal according to another embodiment of the present invention.
12 is a diagram illustrating another example of additional radio resource configuration indication information that can be included in the first signal according to another embodiment of the present invention.
13 is a diagram illustrating another example of additional radio resource configuration indication information that may be included in a first signal according to another embodiment of the present invention.
FIG. 14 is a diagram illustrating another example of additional radio resource configuration indication information that may be included in a first signal according to another embodiment of the present invention.
15 is a diagram illustrating an example of additional radio resource configuration failure information according to another embodiment of the present invention.
16 is a flowchart illustrating an operation of a terminal according to another embodiment of the present invention.
FIG. 17 is another flowchart illustrating another embodiment of the operation of a terminal according to another embodiment of the present invention.
18 is a flowchart illustrating an operation of a base station according to another embodiment of the present invention.
19 is another flow chart showing another embodiment of the operation of the base station according to another embodiment of the present invention.
20 is a diagram illustrating a configuration of a terminal according to another embodiment of the present invention.
21 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference numerals whenever possible, even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

The wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data and the like. A wireless communication system includes a user equipment (UE) and a base station (BS, or eNB). The term " user terminal " in this specification is a comprehensive concept of a terminal in a wireless communication, and includes a mobile station (MS), a user terminal (UT) (Subscriber Station), a wireless device, and the like.

A base station or a cell generally refers to a station that communicates with a user terminal and includes a Node-B, an evolved Node-B (eNB), a sector, a Site, a BTS A base transceiver system, an access point, a relay node, a remote radio head (RRH), a radio unit (RU), and a small cell.

That is, in the present specification, a base station or a cell has a comprehensive meaning indicating a part or function covered by BSC (Base Station Controller) in CDMA, Node-B in WCDMA, eNB in LTE or sector (site) And covers various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node, RRH, RU, and small cell communication range.

Since the various cells listed above exist in the base station controlling each cell, the base station can be interpreted into two meanings. i) a device itself providing a megacell, a macrocell, a microcell, a picocell, a femtocell, or a small cell in relation to a wireless region, or ii) the wireless region itself. i indicate to the base station all devices that are controlled by the same entity or that interact to configure the wireless region as a collaboration. An eNB, an RRH, an antenna, an RU, an LPN, a point, a transmission / reception point, a transmission point, a reception point, and the like are exemplary embodiments of a base station according to a configuration method of a radio area. ii) may indicate to the base station the wireless region itself that is to receive or transmit signals from the perspective of the user terminal or from a neighboring base station.

Therefore, a base station is collectively referred to as a megacell, a macrocell, a microcell, a picocell, a femtocell, a small cell, an RRH, an antenna, an RU, a low power node (LPN), a point, an eNB, Quot;

Herein, the user terminal and the base station are used in a broad sense as the two transmitting and receiving subjects used to implement the technical or technical idea described in this specification, and are not limited by a specific term or word. The user terminal and the base station are used in a broad sense as two (uplink or downlink) transmitting and receiving subjects used to implement the technology or technical idea described in the present invention, and are not limited by a specific term or word. Here, an uplink (UL, or uplink) means a method of transmitting / receiving data to / from a base station by a user terminal, and a downlink (DL or downlink) .

There are no restrictions on multiple access schemes applied to wireless communication systems. Various multiple access schemes such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), OFDM-FDMA, Can be used. An embodiment of the present invention can be applied to asynchronous wireless communication that evolves into LTE and LTE-Advanced via GSM, WCDMA, and HSPA, and synchronous wireless communication that evolves into CDMA, CDMA-2000, and UMB. The present invention should not be construed as limited to or limited to a specific wireless communication field and should be construed as including all technical fields to which the idea of the present invention can be applied.

A TDD (Time Division Duplex) scheme in which uplink and downlink transmissions are transmitted using different time periods, or an FDD (Frequency Division Duplex) scheme in which they are transmitted using different frequencies can be used.

In systems such as LTE and LTE-Advanced, the uplink and downlink are configured on the basis of one carrier or carrier pair to form a standard. The uplink and the downlink are divided into a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator CHannel (PCFICH), a Physical Hybrid ARQ Indicator CHannel, a Physical Uplink Control CHannel (PUCCH), an Enhanced Physical Downlink Control Channel (EPDCCH) Transmits control information through the same control channel, and is configured with data channels such as PDSCH (Physical Downlink Shared CHannel) and PUSCH (Physical Uplink Shared CHannel), and transmits data.

On the other hand, control information can also be transmitted using EPDCCH (enhanced PDCCH or extended PDCCH).

In this specification, a cell refers to a component carrier having a coverage of a signal transmitted from a transmission point or a transmission point or a transmission / reception point of a signal transmitted from a transmission / reception point, and the transmission / reception point itself .

The wireless communication system to which the embodiments are applied may be a coordinated multi-point transmission / reception system (CoMP system) or a coordinated multi-point transmission / reception system in which two or more transmission / reception points cooperatively transmit signals. antenna transmission system, or a cooperative multi-cell communication system. A CoMP system may include at least two multipoint transmit and receive points and terminals.

The multi-point transmission / reception point includes a base station or a macro cell (hereinafter referred to as 'eNB'), and at least one mobile station having a high transmission power or a low transmission power in a macro cell area, Lt; / RTI >

Hereinafter, a downlink refers to a communication or communication path from a multipoint transmission / reception point to a terminal, and an uplink refers to a communication or communication path from a terminal to a multiple transmission / reception point. In the downlink, a transmitter may be a part of a multipoint transmission / reception point, and a receiver may be a part of a terminal. In the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted / received through a channel such as PUCCH, PUSCH, PDCCH, EPDCCH, and PDSCH is expressed as 'PUCCH, PUSCH, PDCCH, EPDCCH and PDSCH are transmitted and received'.

In the following description, an indication that a PDCCH is transmitted or received or a signal is transmitted or received via a PDCCH may be used to mean transmitting or receiving an EPDCCH or transmitting or receiving a signal through an EPDCCH.

That is, the physical downlink control channel described below may mean a PDCCH, an EPDCCH, or a PDCCH and an EPDCCH.

Also, for convenience of description, EPDCCH, which is an embodiment of the present invention, may be applied to the portion described with PDCCH, and EPDCCH may be applied to the portion described with EPDCCH according to an embodiment of the present invention.

Meanwhile, the High Layer Signaling described below includes RRC signaling for transmitting RRC information including RRC parameters.

The eNB performs downlink transmission to the UEs. The eNB includes a physical downlink shared channel (PDSCH) as a main physical channel for unicast transmission, downlink control information such as scheduling required for reception of a PDSCH, A physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission in a Physical Uplink Shared Channel (PUSCH). Hereinafter, the transmission / reception of a signal through each channel will be described in a form in which the corresponding channel is transmitted / received.

Small cells using low power nodes are being considered as a means to cope with mobile traffic explosion. A low power node represents a node using lower transmit (Tx) power than a typical macro node.

In the Carrier Aggregation (CA) technology prior to 3GPP Release 11, a small cell can be constructed using a low power RRH (Remote Radio Head) which is a geographically dispersed antenna within macro cell coverage.

However, in order to apply the CA technology described above, the macro cell and the RRH cell are configured to be scheduled under the control of one base station, and an ideal backhaul is required between the macro cell node and the RRH.

An ideal backhaul refers to a backhaul that exhibits very high throughput and very little delay, such as a dedicated point-to-point connection using optical fiber, LOS microwave (Line Of Sight microwave).

In contrast, a backhaul that exhibits relatively low throughput and large delay, such as Digital Subscriber Line (xDSL) and Non-LOS microwave, is called a non-ideal backhaul.

The plurality of serving cells may be merged through the single base station based CA technology described above to provide services to the terminal. That is, a plurality of serving cells may be configured for a terminal in a state of a radio resource control (RRC) connected state, and when an ideal backhaul is established between the macro cell node and the RRH, And RRH cells together constitute serving cells to provide services to the UE.

When a single base station based CA technology is configured, the terminal may have only one RRC connection with the network.

Access Stratum (hereinafter referred to as "NAS") mobility information (for example, TAI: information indicating the number of serving cells) in RRC connection establishment / re-establishment / Tracking Area Identity, and one serving cell provides a security input in RRC connection reset / handover. These cells are called PCell (Primary Cell). PCell can only be changed with the handover procedure. Depending on the capabilities of the terminals, SCells (Secondary Cells) can be configured as serving cells with PCells.

In such a single base station based CA technology, the SCell is only served as an additional radio resource on the physical layer, and PCell can use the Channel Quality Indicator (CQI) and measurement result to detect the radio link problem in SCell . Also, SCell did not have a Radio Link Monitoring (RLM) terminal procedure on SCell because SCell was able to deactivate / remove SCell if there was a wireless link problem.

The multiple carrier attributes of the physical layer in the single base station based CA described above only affected the MAC layer (Medium Access Control). The MAC layer has one independent Hybrid Automatic Retransmission request (HARQ) entity for each serving cell in the uplink and downlink. In addition, each HARQ entity processes a data stream of a component carrier (CC).

The addition and removal of SCells in the single base station based CA described above is performed by an RRC Connection Reconfiguration message. When adding a new SCell, dedicated RRC signaling is used to send all the necessary system information of the SCell. That is, in the connected mode, the terminal need not directly acquire the broadcasted system information.

If the RRC connection reconfiguration message received from the PCell includes a SCell additional modification list (sCellToAddModList), the UE adds or modifies the SCell. That is, SCell corresponding to the cell identifier is added to each SCell index (sCellIndex) included in the SCell additional modification list (sCellToAddModList) which is not part of the current terminal configuration.

And configure the SCell to be deactivated in the lower layer. Modify the SCell configuration for each SCell index (sCellIndex) contained in the SCell additional modification list (sCellToAddModList) which is part of the current terminal configuration.

A deactivated SCell must be activated to utilize the resources of the added / modified SCell as described above. That is, the SCell's carrier can be used through the SCell addition step and the separate activation step.

Therefore, while the UE configures the SCell addition, the SCell addition failure does not occur due to the failure of the SCell radio link. That is, a radio resource configuration for using radio resources provided by at least two different network points in a conventional single base station based CA technology is performed through an RRC message including SCell addition information in the PCell, and a separate activation SCell radio link failure in the SCell radio resource configuration process was not considered because the mobile station uses the radio resources configured through the step.

However, in the Dual Connectivity configuration of the present invention, which will be described in detail below, it is necessary to consider failure of a radio link of a cell to be additionally configured when a UE is further configured with a cell associated with the second base station. The present invention for solving such problems will be described in detail below.

Unlike the single base station based CA technology described above, the dual connection technology requires a radio resource (e.g., a base station and a secondary base station) provided by at least two different network points (e.g., a master base station and a secondary base station) . &Lt; / RTI >

For example, a dual connection is a technique for a terminal to transmit and receive data through cells associated with two different base stations, and to process high-speed large-capacity data of the terminal.

The present invention provides a method and apparatus for handling a radio link failure problem or the like that occurs in a process of adding / modifying a secondary base station radio resource when a terminal forms a dual connection.

Thus, the meaning of each word in the double connection to which the present invention may be applied may be somewhat different from the meaning in CA.

Hereinafter, in this specification, a terminal establishes an RRC connection with a terminal, terminates a base station or an S1-MME that provides a PCell serving as a reference for handover, configures a mobility anchor ) As a master base station or a first base station.

The master base station or the first base station may be a base station that provides macrocells and may be a base station that provides any small cell in the case of a double connection between small cells.

Meanwhile, a secondary base station or a second base station, which is distinguished from the master base station and provides additional radio resources to the terminal in the dual connection configuration, is described as a secondary base station or a second base station.

Each of the first base station (master base station) and the second base station (secondary base station) can provide radio resources to the terminal through at least one cell, and the first base station and the second base station can provide an interface Lt; / RTI >

Hereinafter, to facilitate understanding of the present invention, a cell associated with a first base station may be referred to as a macro cell, and a cell associated with a second base station may be referred to as a small cell. However, in the small cell cluster scenario described below, the cell associated with the first base station may also be described as a small cell.

The macrocell in the present invention may mean at least one or more cells, and may be referred to as collectively referring to all the cells associated with the first base station. Also, a small cell may mean at least one or more cells, and may be referred to as collectively referring to the entire cell associated with the second base station. However, in a specific scenario, such as a small cell cluster as described above, it may be a cell associated with the first base station, in which case the cell of the second base station may be described as another small cell or another small cell.

In addition, the terminal can perform communication through a plurality of cells associated with the first base station and a plurality of cells associated with the second base station, and in this case, among the plurality of cells associated with the first base station, A specific cell may be described as a first base station PCell and a specific cell among a plurality of cells associated with the second base station may be described as a second base station PCell. The second base station PCell is a cell that performs all or a part of the functions of the PCell described above.

In the above-described conventional CA technology, when different base stations are connected to a non-ideal backhaul, it has not been possible to configure the base station to use radio resources provided by different network points. In particular, the existing single base station based CA technology did not need to consider the SCELL radio link failure in SCell configuration process.

Therefore, in the process of constructing the additional radio resource that can be provided by the non-ideal backhaul-connected secondary base station in the dual connection configuration to which the present invention can be applied, it is possible to prevent a failure or an exceptional situation on the secondary base station radio link There was a problem.

In order to solve the above problems, the present invention provides a concrete configuration procedure for using radio resources provided by one or more different base stations connected through a non-ideal backhaul. In particular, when a wireless link failure occurs in the process of configuring additional radio resources that can be provided by a secondary base station to use radio resources provided by one or more different base stations connected through a non-ideal backhaul, And to provide a method and an apparatus capable of performing the above-described operations.

First, each deployment scenario of a non-ideal backhaul connected duplex network configuration to which the present invention can be applied will be described with reference to the drawings.

1 is a diagram illustrating an example of a network configuration to which the present invention can be applied.

1, small cells (e.g., a small cell cluster 101) provided by the macro cells 102 and the second base stations 132, 134, and 136 provided by the first base station 110 And can have the same carrier frequency F1.

The first base station 110 providing the macro cell and the second base station 132, 134, 136 providing each small cell are connected via a non-ideal backhaul. The small cells are built in an overlaid macrocell 102 network. An outdoor small cell environment and a small cell cluster 101 may be considered.

A terminal may be provided with a plurality of serving cells by forming a dual connection with a macro cell and a small cell in the small cell cluster 101. Also, the first base station 110 and the second base stations 132, 134, and 136 may be configured to establish a dual connection to perform communication.

2 is a diagram showing another example of a network configuration to which the present invention can be applied.

Referring to FIG. 2, the macro cell 202 and the small cells 201 may have different carrier frequencies F1 and F2.

The first base station 210 providing the macro cell and the second base station 232, 234, 236 providing each small cell are connected through a non-ideal backhaul. The small cells are built in an overlaid macrocell 202 network. An outdoor small cell environment and a small cell cluster 201 can be considered.

A terminal can receive a plurality of serving cells through a double connection with a macro cell and a small cell within a small cell cluster 201. In this case, the frequency of each serving cell may be different between F1 and F2 as shown in Fig.

3 is a diagram illustrating another example of a network configuration to which the present invention can be applied.

Referring to FIG. 3, a case in which a plurality of small cells form a small cell cluster 301 can be considered. In this case, non-ideal backhaul is connected between the base stations 310, 312, and 314 providing a small cell. An indoor small cell environment and a small cell cluster 301 are considered.

In FIG. 3, any one of the plurality of base stations providing the small cell may be the first base station, and the remaining base stations other than the first base station may be the second base station. The UE may establish a dual connection with the first and second base stations to transmit and receive data through a plurality of serving cells.

In an exemplary embodiment of the present invention, the UE may transmit user plane data through one or more second base stations under the control of the first base station in the scenario of FIG. 1 and FIG.

Alternatively, it may be possible to transmit user plane data via cooperation between the first base station and one or more second base stations.

Alternatively, in the scenario of FIG. 3, the user plane data may be transmitted through cooperation between the first base station and the second base station.

That is, in order to transmit control plane data, the UE establishes one RRC connection with the first base station, configures one or more DRBs (Data Radio Bearers) with the first base station and the second base station can do. To this end, a terminal establishing an RRC connection with a first base station may configure additional radio resources to a second base station connected to the non-ideal backhaul.

As another example of the present invention, in cooperation with a first base station and one or more second base stations under the control of a first base station in the scenario of FIGS. 1 and 2, or in cooperation with a first base station and a second base station It is possible to transmit the user plane data to only the first base station or to transmit the user plane data to only the second base station. That is, for control plane data transmission, the UE establishes one RRC connection with the first base station, and can configure one or more DRBs only through the first base station. And / or configure one or more DRBs only through the second base station.

Hereinafter, a process for the terminal to construct a dual connection by adding an additional radio resource configuration of the second base station will be described with reference to the drawings, for example.

FIG. 4 is a diagram illustrating exemplary operations of a terminal and a base station that additionally configure a radio resource of a second base station according to an embodiment of the present invention.

Referring to FIG. 4, the first base station 402 transmits a message for controlling the measurement of the terminal 401 (S410). The terminal 401 performs measurement based on the measurement control information received from the first base station 402. That is, the terminal 401 measures the channel quality of the cell associated with the second base station, the channel quality of the cell associated with the first base station, and the like based on the measurement control information.

The terminal 401 transmits a measurement report including the measured result information to the first base station 402 (S420). The measurement report may be transmitted at a specific time point or periodically based on the measurement control information.

The first base station 402 receives the measurement report from the terminal 401 and determines whether the terminal 401 is offloaded (S430). For example, information on each channel quality and the like included in the data request and measurement report of the terminal 401 is summed up to determine whether to offload the terminal based on a preset reference.

If the first base station 402 determines to offload some of the data processing of the terminal 401, it transmits an offload request message to the second base station 403 (S440). The second base station 403 can determine the base station 402 based on the measurement report by providing the base station 402 with additional radio resources to perform a part of data processing of the terminal.

The second base station 403 receives the offload request from the first base station 402 and determines whether to approve the request (S450).

If the second base station 403 decides to approve the offload request of the first base station 402, it transmits a response to the offload request to the first base station 402 (S460).

The first base station 402 receives the grant information of the second base station 403 and transmits an upper layer signaling including information for configuring additional radio resources of the second base station to the terminal 401 (S470). The higher layer signaling may be an RRC connection reconfiguration message.

The terminal 401 further configures the radio resources of the second base station based on the higher layer signaling received from the first base station 402, and transmits the higher layer signaling including the second base station addition completion information (S480). The higher layer signaling that the terminal 401 transmits to the first base station 402 may be, for example, an RRC connection reconfiguration complete message.

As described above, the UE can additionally configure the radio resources of the second base station by receiving a message including the additional radio resource configuration information from the first base station. Thus, the terminal can establish a dual connection with the first base station and the second base station.

Hereinafter, each step of the terminal according to the present invention, which has been described with reference to FIG. 4, constituting the dual connection will be described in more detail. A detailed description will be given of a processing method and a method for returning to a previous radio resource configuration when a problem occurs in a radio link or the like in the process of forming a dual connection by the UE and the additional radio resource configuration of the second base station can not be completed .

In describing each step, we will attach a number to help understanding. However, the number of each step may be performed in one step for convenience of explanation, and one step may be performed in two or more steps separately.

1st Example Procedure and method for the terminal to configure additional radio resources.

1) The first base station constitutes a UE measurement procedure.

2) The terminal is triggered to send a measurement report by rule set.

3) The first base station determines offloading of the UE based on measurement report and Radio Resource Management (RRM) information.

For example, the first base station may determine to transmit user plane data via the first base station via the first base station and the second base station, or may determine to transmit user plane data via the first base station via the second base station do. Alternatively, the first base station may determine to transmit the specific DRB (s) through the first base station using the radio resources of the first base station and the second base station, or may determine that the specific DRB (s) And determines to transmit using the radio resource of the base station.

4) The first base station transmits a message (an offload request message) to prepare the additional radio resource configuration to the second base station.

In one example, a message (an offload request message) for preparing an additional radio resource configuration includes information (e.g., an AS-configuration, an E-RAB context) necessary to prepare an additional radio resource configuration at the second base station.

The first base station transmits a message for preparing the above-described additional radio resource configuration, and can cancel the additional radio resource configuration request when a predetermined period elapses.

Specifically, for example, when the first base station sends a message (an offload request message) to prepare the additional radio resource configuration to the second base station, the first base station starts an additional radio resource configuration ready timer. The additional radio resource configuration ready timer indicates a timer for specifying and / or limiting the maximum time to process the message (Offload Request message) procedure for preparing the additional radio resource configuration.

If the first base station does not receive an acknowledgment message (an Offload Request Response (ACK) message) for the message to prepare the additional radio resource configuration before the additional radio resource configuration ready timer has expired, additional radio resources A message for canceling preparation for configuration (an offload cancel message) can be transmitted.

5) Admission control for the offload may be controlled by the second base station. Alternatively, for the E-RAB (s) that has determined offloading based on the E-RAB QoS profile at the first base station, the second base station may not perform the grant decision.

6) The second base station prepares the L1 / L2 additional radio resource configuration. For example, the L1 / L2 entity for the accepted E-RAB (s) or the E-RAB (s) requested to be offloaded is set or prepared.

The second base station sends a message (an Offload Request Response (ACK) message) to the first base station for confirmation of the additional radio resource configuration. The message for confirmation of the additional radio resource configuration is, for example, an offload request response message or an offload request ACK message. The message for confirmation of the additional radio resource configuration may include information necessary for the first base station to generate an RRC message for configuring the additional radio resource of the second base station to transmit to the terminal.

Alternatively, the message for confirming the above-described additional radio resource configuration may be generated and included by the RRC layer of the second base station, for configuring the additional radio resource of the second base station to be transmitted to the terminal by the first base station have. The message for confirmation of the additional radio resource configuration may include a dedicated RACH preamble and other necessary parameters such as SIBs, if necessary.

The second base station may cancel the preparation of additional radio resource configuration after a certain period of time has elapsed after transmitting an acknowledgment message for the additional radio resource configuration request to the first base station.

Specifically, for example, the second base station may send a message for confirmation of the additional radio resource configuration to the first base station, and then start an additional radio resource configuration timer of the second base station.

The additional radio resource configuration timer of the second base station represents a timer for specifying / limiting the maximum time to process additional radio resource configuration procedures in the second base station. The additional radio resource configuration timer of the second base station may be stopped if the additional radio resource configuration of the second base station is successfully completed.

If the second base station does not successfully complete additional radio resources at the second base station before the additional radio resource configuration timer of the second base station expires, the second base station can cancel the ongoing additional radio resource configuration preparation. For this, when the first base station receives a success message (for example, RRC Connection Reconfiguration Complete) for the additional radio resource configuration of the second base station from the terminal, the first base station transmits a success message for the additional radio resource configuration to the second base station send.

If the first base station fails to receive a success message (e.g., RRC Connection Reconfiguration Complete) for the additional radio resource configuration of the second base station from the terminal or fails in a failure message (e.g., an RRC Connection reestablish request or an additional radio resource configuration failure , The first base station transmits a failure message (or cancellation message) for the additional radio resource configuration to the second base station.

Alternatively, the second base station may use the additional radio resource configuration timer of the first base station described below without separately configuring the above-described additional radio resource configuration timer of the second base station. For example, if the first base station does not receive a confirmation message (e.g., RRC Connection Reconfiguration Complete) indicating that the first base station has succeeded in the additional radio resource configuration before the additional radio resource configuration timer of the first base station expires, 2 to cancel the preparation of additional radio resource configuration in progress (offload cancel message) to the base station.

The confirmation message for the additional radio resource configuration request transmitted by the second base station to the first base station may include an RRC message for allowing the UE to configure additional radio resources. In this case, the second base station may generate and include the above-described RRC message by the RRC layer of the second base station.

If the second base station generates and transmits the above-described RRC message by the RRC layer of the second base station, the second base station can generate (additional support) RRC entity for the terminal.

Alternatively, when the second base station generates and transmits the RRC message by the RRC layer of the second base station, the second base station may not generate the RRC entity for the terminal. Alternatively, after generating the RRC entity when generating the RRC message (or additional radio resource configuration information) to configure the additional radio resource of the second base station at the second base station, a success message for the additional radio resource configuration from the first base station If you receive a failure (or cancellation) message for the additional radio resource configuration, you can remove it.

The first base station, which has received the message for confirming the additional radio resource configuration from the second base station, stops the above-described additional radio resource configuration ready timer. And the first base station starts an additional radio resource configuration timer of the first base station.

Alternatively, the additional radio resource configuration timer of the first base station may be started after the first base station transmits an RRC Connection Reconfiguration message to the UE. The additional radio resource configuration timer of the first base station represents a timer that specifies / limits the maximum time to process additional radio resource configuration procedures (e.g., RRC connection reconfiguration) within the first base station.

If the first base station does not successfully complete the additional radio resource configuration procedure before the additional radio resource configuration timer of the first base station has expired, a message for canceling the additional radio resource configuration preparation in progress to the second base station ). &Lt; / RTI > And performs communication with the UE using the radio resource configuration through the first base station.

For example, if the first base station does not receive a success message (e.g., RRC Connection Reconfiguration Complete) for the additional radio resource configuration of the second base station from the terminal, fails to deliver the success message received from the terminal to the second base station It can be determined that the additional radio resource configuration procedure has not been successfully completed.

If the second base station does not accept at least one E-RAB, or if a failure occurs during message processing to prepare an additional radio resource configuration, the second base station sends an additional radio resource configuration ready message (offload failure message) To the first base station. The additional radio resource configuration preparation failure message may include cause information (Cause IE) having an appropriate value.

If the first base station receives a response (an offload request response (ACK) message) for preparing a further radio resource configuration (an offload request message) until the additional radio resource configuration ready timer described above expires, , The first base station may send a message (an offload cancel message) with an appropriate value to the cause information (Cause IE) to cancel the ongoing additional radio resource configuration preparation to the second base station.

If there is no response to the message for preparing the additional radio resource configuration (the offload request message) until the above-described additional radio resource configuration ready timer expires, the first base station transmits a message Load request message) procedure.

As described above, the first base station and / or the second base station can transmit a message to the terminal for additional radio resource configuration, respectively, and can cancel the procedure by operating a related timer.

Hereinafter, an operation of the UE according to a method of configuring a radio bearer in a UE and a Node B in configuring an additional radio resource will be described.

If the UE is configured not to bear bearer for additional radio resource configuration, the first base station may buffer the data packet.

For example, a radio bearer (DRB) configured to use the first base station radio resource or to transmit user data via the first base station may be configured to use the second base station radio resource Or to transmit the user data through the second base station.

In this case, the first base station may buffer the data packet for the next period so that there is no missing data transmitted to the terminal.

For example, after receiving a message for confirmation of the additional radio resource configuration from the second base station or transmitting an RRC connection reconfiguration message to the terminal, the RRC connection reconfiguration It is possible to buffer the data packet until receiving the completion message.

Alternatively, the first base station may transmit data to the mobile station using the first base station radio resource instead of buffering the corresponding data packet during the above period.

Alternatively, the first base station may send a sequence number state trans- fer (SN STATUS TRANSFER) to the second base station to preserve the PDCP state and transmit the uplink PDCP SN receiver state for the corresponding radio bearer (E-RABs) State. And transmit the data of the first base station to the second base station.

Alternatively, if the radio bearer for additional radio resource configuration is configured to be bearer split, the first base station may continue to transmit data using the first base station radio resource.

Specifically, for example, a radio bearer (DRB) configured to transmit user data (using the first base station radio resource) via a first base station is communicated via a first base station and a second base station 2 base station radio resource), it is possible to continue the data transmission through the first base station during the above period.

Alternatively, if the radio bearer for additional radio resource configuration is configured to be separated, the corresponding data packet can be buffered during the above period.

7) The first base station transmits an RRC Connection Reconfiguration message to the UE. For example, the RRC connection reconfiguration message described above may include information for indicating that the message is for the additional radio resource configuration of the second base station.

Information for additional radio resource configuration at the second base station will be described in detail below by way of example.

8) When the UE receives an RRC Connection Reconfiguration message including information for additional radio resource configuration of the second base station, the UE can start a timer for limiting the additional radio resource configuration time of the UE.

The timer for limiting the additional radio resource configuration time of the UE includes a timer included in the information for additional radio resource configuration (for example, distinguished from the T304 timer or the T304 timer) to the second base station included in the RRC connection reconfiguration message Lt; / RTI > Alternatively, the timer value described above may be a preset value configured in the terminal.

The UE can stop the timer for limiting the additional radio resource configuration time of the UE if the additional radio resource configuration is successfully completed before the timer for limiting the additional radio resource configuration time of the UE expires.

Successful completion of the additional radio resource configuration of the UE includes, for example, transmission of an RRC connection reconfiguration completion message, when the MAC successfully aligns uplink synchronization, and at least one of completing the random access process successfully with the second base station is completed Lt; / RTI >

If the timer expires before the additional radio resource configuration is successfully completed, the UE may revert to the radio resource configuration (configuration before receiving the RRC Connection Reconfiguration message) originally used by the first base station. For example, if the radio bearer information configured for the radio resource configuration included in the RRC Connection Reconfiguration message is configured to transmit user data (using the first base station radio resource) through the first base station, (Using the first base station radio resource) via the previous first base station if it comprises radio bearer addition correction information for configuring the base station to transmit user data (using the second base station radio resource) (DRB) configuration can be used to resume data transfer.

Or a radio bearer in which the information for radio resource configuration included in the RRC Connection Reconfiguration message is configured to transmit user data (using the first base station radio resource) through the first base station is referred to as a first base station and a second base station (Using the first base station radio resource and the second base station radio resource) via the first base station (e.g., the first base station radio resource and the second base station radio resource) To resume data transmission using a configured radio bearer (DRB) configuration.

And may store the additional radio resource configuration failure information in a new information element for the VarRLF-Report or the second base station addition radio resource configuration failure report, or send the indication information about the second base station addition radio resource configuration failure to the first base station. The additional radio resource configuration failure information included in the new information element for the above-described VarRLF-Report or the second base station additional radio resource configuration failure report or the indication information for the second base station additional radio resource configuration failure is described in detail below do.

Further, the operation of the additional radio resource configuration failure according to each embodiment of the present invention will be described in more detail with reference to the drawings hereinafter.

5 is a diagram illustrating an example of a bearer-separated additional radio resource configuration for further configuring a radio resource of a second base station according to another embodiment of the present invention.

As described above, in constructing the dual connection unlike the existing CA technology, the terminal can perform the additional radio resource configuration and the second base station access procedure together or sequentially. In particular, the terminal may perform synchronization with the second base station and access the second base station via the RACH if necessary. That is, the terminal may configure additional radio resources through the second base station before performing synchronization with the second base station and accessing the second base station via the RACH. Alternatively, the terminal may establish synchronization with the second base station and configure additional radio resources via the second base station while accessing the second base station via the RACH. Alternatively, the terminal may configure additional radio resources via the second base station after performing synchronization with the second base station and accessing the second base station via the RACH.

For example, referring to FIG. 5, when a radio bearer configured to transmit user data through a first base station is separated and transmitted through a first base station and a second base station, a radio bearer For each DRB identifier (drb-Identity) included in the additional modification information (drb-ToAddMod), if rlc-config is included, the RLC entity or entities are reconstructed according to the received rlc-config.

For example, the rlc-config may include rlc-config of the terminal RLC entity to be peered to the first base station RLC entity, and rlc-config of the terminal RLC entity to be peered to the second base station RLC entity. Specifically, the terminal RLC entity to be peered to the first base station RLC entity is re-established, and the terminal RLC entity to be peered to the second base station is set. The terminal RLC entity that is peered to the received second base station RLC entity, Configure it with -config.

If logicalChannelConfig is included, the logical channel is reconfigured according to the received logicalChannelConfig.

The above-mentioned rlc-config and / or logicalChannelConfig may contain new information for bearer-separated additional radio resource configuration.

FIG. 6 is a diagram illustrating an example of a configuration of a bearer non-separated additional radio resource for further configuring a radio resource of a second base station according to another embodiment of the present invention.

Referring to FIG. 6, a first BS configures a PDCP entity, and an RLC entity and a MAC entity are configured in a second BS.

FIG. 7 is a diagram illustrating another example of an additional radio resource configuration in which a bearer is not separated, which further configures a radio resource of a second base station according to another embodiment of the present invention.

Referring to FIG. 7, each of the first base station and the second base station may configure a PDCP entity, an RLC entity, and a MAC entity.

As can be seen in FIGS. 6 and 7, in this case, each radio bearer can be configured via the first base station or through the second base station without bearer separation that separates the radio bearer through the first and second base stations.

6 and 7, when a radio bearer configured through the first base station is to be transmitted through the second base station without bearer separation, the radio bearer addition correction information drb- If the rlc-config (rlc-config of the terminal RLC entity to be peered to the second base station RLC entity) is included for each DRB identifier (drb-Identity) contained in the RLC entity (ToAddMod) Reconstruct objects or objects.

For example, the terminal RLC entity to be peered to the first base station is reset with the rlc-config of the terminal RLC entity to be peered to the received second base station RLC entity. If the logicalChannelConfig is included, the logical channel is reconfigured according to the received logicalChannelConfig. The logicalChannelConfig described above may contain new information for additional bearer-separated radio configurations.

If the UE configures the additional radio resource through the second base station, the UE can transmit a RRC Connection Reconfiguration Complete message to the first base station. For example, before the UE performs synchronization with the second base station and accesses the second base station via the RACH, it configures additional radio resources through the second base station and transmits an RRC Connection Reconfiguration Complete message To the first base station.

For example, while the UE performs synchronization with the second base station and accesses the second base station via the RACH, the UE configures additional radio resources through the second base station and performs RRC Connection Reconfiguration Complete, Message to the first base station. Specifically, after the UE performs downlink synchronization with the second base station and configures additional radio resources through the second base station, it can transmit an RRC Connection Reconfiguration Complete message to the first base station. Thereafter, the second base station can be accessed via the RACH. Or if the terminal performs downlink synchronization with the second base station and accesses the second base station via the RACH, additional wireless resources through the second base station are configured in the terminal, the terminal can not complete the random access with the second base station May also send an RRC Connection Reconfiguration Complete message to the first base station.

In another example, after the UE performs synchronization with the second base station and accesses the second base station via the RACH, the UE configures additional radio resources through the second base station and performs RRC connection reconfiguration completion ) Message to at least one of the first base station and the second base station.

In another method, the UE adds / modifies wireless resources to / from the UE according to the radio bearer addition correction information (drb-ToAddMod) received through the RRC connection reconfiguration message only when the UE can successfully access the second base station . For example, if the second base station radio resource is already configured before the RRC connection reconfiguration message is received and the terminal can perform communication via the second base station, or the terminal successfully completes the random access process with the second base station (For example, when the terminal attempts to access the second base station using the RACH preamble generated by the second base station and received via the first base station, and receives a random access response (RA response) message from the second base station) To add / modify the radio bearer for configuring the additional radio resource via the second base station to the terminal only when the radio bearer is connected to the second base station.

If the UE successfully accesses the second Node B, the UE can transmit a Connection Reconfiguration Complete message to at least one of the first Node B and the second Node B. A method in which a UE sends an RRC connection reconfiguration completion message to a first base station will be described below by way of example.

Upon receiving the RRC connection reconfiguration completion message, the first base station sends a success message for the additional radio resource configuration to the second base station and starts to send data to the terminal through the second base station.

Hereinafter, the procedure for configuring the additional radio resources by the first and second base stations and the UE according to the present invention has been described in detail with reference to FIG. 4 through FIG.

Hereinafter, a processing method according to the present invention in a case where a problem occurs in the UE performing the additional radio resource configuration to the second base station in the eighth step of the above-described additional radio resource configuration procedure will be described with reference to the drawings.

Second Example : Procedures and methods for handling additional radio resource configuration problems.

In the process of FIG. 4 to FIG. 7, in the process of configuring the additional radio resource unlike the existing CA technology, the UE may have a problem that the additional radio resource configuration can not be completed due to a random access problem with the second base station have.

In this case, the UE can solve the problem by resuming the existing radio resource configuration using the radio resources of the first base station before setting the additional radio resource configuration of the second base station.

Hereinafter, a concrete method and procedure for resuming the existing radio resource configuration when a problem occurs in the configuration of the additional radio resource of the second base station according to another embodiment of the present invention will be described with reference to the drawings.

FIG. 8 is a diagram illustrating exemplary operations of a UE and a base station in the case of an additional radio resource configuration failure according to another embodiment of the present invention.

A method for constructing a dual connection with a plurality of base stations according to another embodiment of the present invention includes receiving a first signal including information for further configuring a radio resource from a first base station through a second base station Further radio resource configuration via the second base station and random access with the second base station based on the first signal and step of attempting random access with the second base station or additional radio resource configuration via the second base station , Transmitting a second signal including additional radio resource configuration failure indication information to the first base station.

Referring to FIG. 8, the first base station 802 transmits a first signal including information for indicating an additional radio resource configuration through the second base station to the terminal 801 (S810).

The first signal may include an RRC connection reconfiguration message as described in FIG. 4, for example, and may include information for indicating an additional radio resource configuration via the second base station and for configuring additional radio resources through the second base station And may include necessary information.

The terminal 801 configures additional radio resources based on the received first signal (S820). For example, a bearer separation or bearer non-separated radio bearer can be configured based on the first signal. Or an existing RLC entity may be set as an RLC entity mapped to the first base station based on the first signal and an RLC entity mapped to the second base station.

The terminal 801 may attempt random access with the second base station 803 before constructing the additional radio resource or configuring the additional radio resource or after configuring the additional radio resource (S830). For the sake of convenience of description, an embodiment in which a random access is attempted after configuring an additional radio resource will be described, but all the cases may be included before or after the configuration of the additional radio resource as described above. That is, the order of steps S820 and S830 may be changed or may be performed in the same step.

If the terminal 801 attempts random access with the second base station 803 after configuring the additional radio resource, the terminal 801 may configure the additional radio resource based on the received first signal (S820) And sending an RRC connection reconfiguration complete message prior to attempting random access (S830). Alternatively, even if the terminal 801 attempts random access with the second base station 803 after configuring the additional radio resource, the terminal 801 may configure the additional radio resource based on the received first signal (S820 (E.g., receiving a random access response message) and attempting random access (S830) to send an RRC connection reconfiguration completion message. When the terminal 801 constructs the additional radio resource based on the first signal, if the additional radio resource configuration fails or a connection to the second base station 803 fails (S840) 1 base station 802 (S850).

Further, in accordance with another embodiment of the present invention, a second base station identification information related to a failure in case of failure of the additional radio resource configuration through the second base station or the random access with the second base station, the cell associated with the second base station Identifying information and frequency information to the radio link failure report or the second base station additional radio resource configuration failure report.

The second signal may include additional radio resource configuration failure indication information of the UE 801 and may be transmitted through higher layer signaling. For example, in an RRC connection reconfiguration complete message, or may be included in an RRC connection reconfiguration message. As another example, a new RRC message (e.g., an RRC connection reconfiguration failure message or an RRC connection reconfiguration recovery request message or an indication of a random access attempt failure due to an additional radio resource configuration indication) that is not an RRC connection reconfiguration complete message or an RRC connection reset message Message). &Lt; / RTI >

If the terminal 801 fails to complete the above-described additional radio resource configuration, the terminal 801 can resume the radio resource configuration with the first base station 802 before the first signal is received (S860). Step S860 may be performed after step S850 of transmitting the second signal, or may be performed before step S850. The radio resource configuration with the first base station before receiving the first signal may comprise a data radio bearer through the first base station before receiving the first signal. In order to allow the terminal 801 to resume the radio resource configuration with the first base station 802 before the first signal is received and to perform communication when the above-described completion of the above-described additional radio resource configuration is unsuccessful, When executing a procedure for configuring additional radio resources of two base stations, it is possible to store the radio resource configuration with the first base station before receiving the temporary first signal.

If the step S860 is performed after step S850, the UE may further include receiving an RRC connection reconfiguration message including a radio resource configuration with the first base station 802 before receiving the first signal.

Alternatively, it may not include the step of receiving an RRC connection reconfiguration message including a radio resource configuration with the first base station 802 before receiving the first signal, even if performed after step S850.

If the terminal 801 further includes a step of sending an RRC connection reconfiguration completion message before the step S830 of attempting random access after the step S820 of configuring the additional radio resource based on the received first signal, If the random access with the second base station 803 fails (S840), the terminal transmits the second signal to the first base station 802 (S850).

The second signal may include additional radio resource configuration failure indication information (or random access failure indication information for additional radio resource configuration) of the UE 801 and may be transmitted through higher layer signaling or MAC signaling. For example, an RRC connection reconfiguration complete message or an RRC connection reconfiguration message.

As another example, a new RRC message (e.g., an RRC connection reconfiguration failure message or an RRC connection reconfiguration recovery request message or an indication of a random access attempt failure due to an additional radio resource configuration indication) that is not an RRC connection reconfiguration complete message or an RRC connection reset message Message). &Lt; / RTI >

As another example, it may be transmitted to the first base station via MAC signaling indicating a random access attempt failure by an additional radio resource configuration for fast recovery.

The terminal 801 can resume the radio resource configuration with the first base station 802 before receiving the first signal and perform the communication (S860). Step S860 may be performed after step S850 of transmitting the second signal, or may be performed before step S850. If the step S860 is performed after the step S850, the terminal 801 stops the data radio bearer configured at the second base station before transmitting the second signal, and stops receiving the first signal after transmitting the second signal And receiving an RRC connection reconfiguration message including a radio resource configuration with the first base station 802 before the RRC connection reconfiguration message. Alternatively, even if it is performed after step S850, the terminal stores the radio resource configuration with the first base station before receiving the temporary first signal while executing the procedure constituting the additional radio resource of the second base station , The UE terminates the data radio bearer configured at the second base station before transmitting the second signal and terminates the data radio bearer with the first base station 802 before receiving the first signal after transmitting the second signal The first base station 802 may receive a second signal including information on an additional radio resource configuration failure from the terminal 801 and transmit the RRC connection reconfiguration message to the UE 801. [ And transmits an additional radio resource configuration cancellation message to the 2 base stations (S870).

The second base station 803 can terminate the additional radio resource configuration procedure for the dual connection configuration with the terminal 801 upon receiving the additional radio resource configuration cancellation message from the first base station 802. [

The operation of the terminal and the base station in the case where the additional radio resource configuration of the second base station according to the present invention can not be completed has been described above.

Hereinafter, detailed embodiments of the first signal and the second signal described in each step will be described with reference to the drawings.

The first base station transmits a signal including information for additional radio resource configuration via the second base station to the terminal. Referring to FIG. 8, the first base station transmits the first signal to the terminal. In addition, a specific example of the first signal is described in detail in FIG. 4 in an RRC connection reconfiguration message as an example.

Also, in another embodiment of the present invention, the first signal may be received via higher layer signaling, and may further include additional radio resource configuration indication information through the second base station. The additional radio resource configuration indication information is information for indicating that the signal is a message for additional radio resource configuration through the second base station.

That is, the first signal or the RRC connection reconfiguration message described in one embodiment may include information for additional radio resource configuration through the second base station and additional radio resource configuration indication information.

The UE can recognize that the message is a signal for further configuring the radio resource of the second base station based on the additional radio resource configuration indication information.

With reference to FIG. 9 to FIG. 14, the detailed radio resource indication information will be described.

The additional radio resource indication information, which is information for indicating that the first signal is a message for additional radio resource configuration to the second base station, may be configured in the following detailed embodiments.

First Detailed Embodiment : A method comprising a field for displaying an additional radio resource configuration in MobilityControlInfo.

9 is a diagram illustrating an example of additional radio resource configuration indication information that may be included in a first signal according to another embodiment of the present invention.

The first signal transmitted by the first base station to the terminal may include additional radio resource configuration indication information indicating that the second base station is a message for additional radio resource configuration.

The first signal may be transmitted via higher layer signaling, for example, an RRC Connection Reconfiguration message.

The first signal may be generated by the first base station, or may be generated by the second base station and communicated through the first base station.

Referring to FIG. 9, the first signal may include a new field in the MobilityControlInfo information element to indicate to the second base station that the message is for additional radio resource configuration.

As shown in FIG. 9, the MobilityControlInfo information element may additionally include a SeNBradioresourceconfig field, and if the value is set to true, it may indicate that the message is for additional radio resource configuration.

That is, the SeNBradioresourceconfig field provides information on whether the first signal received by the terminal (for example, the RRC connection reconfiguration message) is a signal for further configuring the second base station radio resource.

Second Detailed Embodiment : A method for including a field for displaying an additional radio resource configuration in SCellToAddMod.

10 is a diagram illustrating another example of additional radio resource configuration indication information that may be included in a first signal according to another embodiment of the present invention.

Referring to FIG. 10, the first signal may include a new field in the SCell information element to indicate to the second base station that the message is for additional radio resource configuration.

As an example, the SeNBradioresourceconfig field and the ARRCtimer field can be added to the SCellToAddMod-r10 information element to display it.

The SeNBradioresourceconfig field may contain indication information about whether the first signal is a message for additional radio resource configuration in the second base station. For example, it may be information indicating that a cell having a specific cell index (sCellIndex) included in the SCellToAddMod-r12 information element is a cell associated with the second base station.

Alternatively, define a new sCellIndex-12 field that does not include the SeNBradioresourceconfig field and is distinguished from sCellIndex-10 so that a cell with a particular cell index (sCellIndex) included in the SCellToAddMod-r12 information element is a cell associated with the first base station Or a cell associated with the second base station.

The ARRCtimer field includes timer information for additional radio resource configuration of the UE. The ARRCtimer may be initiated when the UE receives a first signal (e.g., an RRC Connection Reconfiguration message) containing information for additional radio resource configuration via the second base station. And may be stopped when the additional radio resource configuration of the terminal is successfully completed.

A concrete example of the successful completion of the additional radio resource configuration of the UE is as follows. In the case where the MAC successfully matches the uplink synchronization, when the random access process is successfully completed and when the RRC Connection Reconfiguration Complete message And the like.

As described above with reference to FIG. 8, if the ARRC timer expires before the UE completes the additional radio resource configuration successfully, the UE can return to the radio resource configuration originally used by the first base station.

Additional radio resource configuration failure information can be stored in the VarRLF-Report. The ARRCtimer may be, for example, a T304 timer or a new timer distinct from the T304 timer. The ARRCtimer for the above-described additional radio resource configuration may not be included in the SCellToAddMod information or may be included in other information elements.

That is, when the UE according to another embodiment of the present invention fails to perform the additional radio resource configuration through the second base station or the random access with the second base station, the UE transmits the second base station identification information related to the failure, Identifying information and frequency information to the radio link failure report or the second base station additional radio resource configuration failure report.

Alternatively, instead of the additional radio resource configuration indication information SeNBradioresourceconfig for indicating the additional radio resource configuration via the second base station, the SCell additional modification information (sCellToAddMod-r12) may include DRB additional modification information (DRB-ToAddMod) And may indicate an additional radio resource configuration via the second base station.

Third Detailed Embodiment : A method for including a new information element for indicating an additional radio resource configuration.

A first signal (e.g., an RRC Connection Reconfiguration message) transmitted from the first base station to the UE includes a new information element different from the existing information element to indicate that the second base station is a message for additional radio resource configuration .

As described above, the information included in the first signal or the first signal may be generated by the first base station, or may be generated by the second base station and transmitted to the terminal through the first base station.

Some embodiments of a new information element different from existing information elements will be described with reference to Figs. 11 to 13. Fig.

11 is a diagram illustrating another example of additional radio resource configuration indication information that may be included in a first signal according to another embodiment of the present invention.

Referring to FIG. 11, the SeNBradioresourceConfig information element may include physical cell identifier information, carrier frequency information, carrier frequency band information, and the like of the target base station (second base station).

Another example of the above-described new information element configuration is shown in Fig.

12 is a diagram illustrating another example of additional radio resource configuration indication information that can be included in the first signal according to another embodiment of the present invention.

Referring to FIG. 12, the SeNBIndex field may include a second base station ID or index information for additional radio resource configuration. Or a SeNBScellIndex field, and the SeNBScellindex field may include cell ID information or cell index information of a cell associated with a second base station for additional radio resource configuration. For example, the SeNBScellIndex information may be information indicating that a cell having a specific second base station cell index (SeNBScellIndex) is a cell associated with the second base station. The second base station cell index (SeNBScellIndex) may be a value distinct from the ScellIndex prior to release-11 to distinguish the cell associated with the first base station. Alternatively, a cell having a specific cell index (sCellIndex) included in the SCellToAddMod-r12 information element may be defined as a new sCellIndex-12 field that does not include the SeNBIndex field or the SeNBScellIndex field but is distinguished from the sCellIndex- Cell or a cell associated with the second base station.

Alternatively, the rach-ConfigDedicated information element may include indication information for additional radio resource configuration.

The ARRCtimer for the above-described additional radio resource configuration may not be included in the SCellToAddMod information or may be included in other information elements.

13 is a diagram illustrating another example of additional radio resource configuration indication information that may be included in a first signal according to another embodiment of the present invention.

Referring to FIG. 13, information for additional radio resource configuration for some cells among a plurality of cells associated with a second base station may be included.

In one example, radio resource configuration information relating to a cell of a second base station to be added including a radioResourceConfigCommonSCell field may be transmitted.

The UE can acquire the system information after receiving the first signal including the new information element described above, performing the random access process to the second base station, and configuring the additional radio resources.

Alternatively, the UE may not acquire the broadcasted system information by receiving the system information (RadioResourceConfigCommonSCell-r10) in the common radio resource configuration (radioResourceConfigCommon) through the RRC message.

Fourth Detailed Embodiment : A method for including a new field for indicating an additional radio resource configuration in a radioResourceConfigDedicated information element.

FIG. 14 is a diagram illustrating another example of additional radio resource configuration indication information that may be included in a first signal according to another embodiment of the present invention.

Referring to FIG. 14, a first signal (e.g., an RRC Connection Reconfiguration message) transmitted from a first base station to a mobile station is transmitted to a second base station in order to indicate that the message is a message for additional radio resource configuration, and a radioResourceConfigDedicated information element May include a new field.

As shown in FIG. 14, if the bearer setup field for additional radio resource configuration is included in the radio bearer addition correction information for radio resource configuration dedicated to radio resource configuration (radio Resource ConfigDedicated), the UE can recognize that the first signal is a message for additional radio resource configuration have.

The SeNBIndex field may include second base station index information or ID information or identifier information or true or false information for additional radio resources of the second base station. That is, when the SeNBIndex field is included, it can indicate that the data radio bearer included in the DRB-ToAddMod is a radio bearer configured through the second base station or using the radio resources of the second base station.

Or an SeNBSCellindex field, and may include index information or ID information or identifier information for a cell to be additionally configured in a plurality of cells associated with the second base station.

Hereinafter, detailed examples of additional radio resource configuration indication information or information for additional radio resource configuration that can be included in the first signal have been exemplarily described with reference to the drawings. Each of the above-described detailed embodiments is illustratively described. In addition, various methods including information for additional radio resource configuration indication and / or information for additional radio resource configuration may be included.

As described with reference to FIGS. 4 and 8, when the UE receives the first signal described above (for example, the RRC connection reconfiguration message), it can start a timer for limiting the additional radio resource configuration time of the UE . The timer for limiting the additional radio resource configuration time may be a timer (T304 timer or ARRC timer) included in the information for additional radio resource configuration in the second base station of the first signal. Alternatively, the timer value may be a preset value configured in the terminal.

When the UE performs additional radio resource configuration based on the received first signal and successfully performs additional radio resource configuration and random access success, the above-mentioned timer is terminated and the UE transmits radio resources of the first base station and the second base station To perform communication.

If the timer expires before the additional radio resource configuration through the second base station is successfully completed, the UE determines that the additional radio resource configuration is unsuccessful and resumes the radio resource configuration before receiving the first signal. Or re-configure / reconfigure the radio resource configuration before receiving the first signal to perform communication using the radio resource of the existing first base station. Thereby, the terminal can reduce unnecessary operations due to the failure of the additional radio resource configuration and can continuously perform communication.

Specifically, for example, when the UE transmits an RRC connection reconfiguration completion message, the MAC entity of the UE successfully synchronizes with the second BS, or the random access process with the second BS completes successfully If the timer has expired before, the terminal may revert to the last radio resource configuration before receiving the first signal including additional radio resource configuration information via the second base station.

For example, if an existing radio bearer configured through the first base station is to be bearer separated or to be transmitted through the second base station without bearer detachment, the terminal proceeds with the configuration based on information for additional radio resource configuration. If the procedure to transmit through the second base station fails, the UE can reconfigure each radio bearer to a radio bearer configuration previously configured through the first base station.

And may store additional radio resource configuration failure information in the new information element for the VarRLF-Report or the second base station addition radio resource configuration failure report. Or a second signal including indication information for a second base station add radio resource configuration failure to the first base station.

An example of the additional radio resource configuration failure information included in the new information element for the above-described VarRLF-Report or the second base station additional radio resource configuration failure report is as follows.

15 is a diagram illustrating an example of additional radio resource configuration failure information according to another embodiment of the present invention.

15, a new information element for a VarRLF-Report or a second base station addition radio resource configuration failure report is transmitted through a field (failedSeNBId or failedSCellId) for identifying a second base station or a second base station which failed to construct an additional radio resource (SCell) information associated with a second base station or a second base station that failed to configure additional radio resources.

A field (failedSeNBId or failedSCellId) for identifying the second base station or the second base station is a cell associated with the secondary cell (SCell) of the second base station or the second base station or the cell Or the global cell identifier of the representative cell of the second base station, and otherwise the physical cell identity and the carrier frequency.

Alternatively, a field (failed second base station Id or failed SCellId) for identifying the SCell of the second base station or the second base station may include a second base station identifier that has failed the additional radio resource configuration or a SCell identifier of the second base station .

The new information element for the VarRLF-Report or the second base station additional radio resource configuration failure report is transmitted by transmitting a first signal (for example, an RRC Connection Reconfiguration message) including the second base station additional radio resource configuration information before configuring the additional radio resource (PreviousPCellId or previousMeNBId) to identify the first base station PCell or the first base station.

The field for identifying the PCELL or the first base station (previousPCellId or previousMeNBId) sets the global cell identifier of the PCELL or the representative cell of the first base station or the first base station cell or the first base station.

Alternatively, the field for identifying the PCell or the first base station (previousPCellId or previousMeNBId) may include a first base station identifier.

A new information element for the VarRLF-Report or the second base station addition radio resource configuration failure report is the elapsed time after receiving the last first signal (for example, the RRC Connection Reconfiguration message) including the additional radio resource configuration information through the timeConnFailure field Can be set.

A new information element for the VarRLF-Report or the second base station addition radio resource configuration failure report may set an additional radio resource configuration failure type or cause value via the connectionFailureType field.

The operation of the terminal and the base station according to each embodiment of the present invention has been described above. Hereinafter, the operation of each of the terminal and the base station according to the present invention will be described with reference to the drawings.

16 is a flowchart illustrating an operation of a terminal according to another embodiment of the present invention.

Referring to FIG. 16, a terminal receives a first signal including information for additional radio resource configuration from a first base station through a second base station (S1610). As described above, the first signal may be transmitted through higher layer signaling, and may further include additional radio resource configuration indication information.

The UE performs a procedure for configuring additional radio resources through the second base station based on the first signal, and attempts random access with the second base station (S1620).

If the timer for limiting the additional radio resource configuration time of the terminal expires before the additional radio resource configuration through the second base station is successfully completed, the terminal indicates to the first base station that the additional radio resource configuration has failed And transmits the second signal including the display information (S1630).

Before the additional radio resource configuration through the second base station is successfully completed, the timer for limiting the additional radio resource configuration time of the above-mentioned terminal expires, and the radio resource configuration report for the VarRLF-Report or the second base station additional radio resource configuration failure report If the new information element is set, the terminal transmits the second signal to the first base station (S1630).

In step S1640, the UE performs the corresponding operation to return to the radio resource configuration with the first base station before receiving the first signal, and resumes the radio resource configuration through the first base station. As described above, the resumption of the radio resource configuration through the first base station means that the bearer configuration for the second base station add-on radio resource configuration is canceled and the radio bearer configuration through the first base station before receiving the first signal .

FIG. 17 is another flowchart illustrating another embodiment of the operation of a terminal according to another embodiment of the present invention.

FIG. 17 is a flowchart illustrating an operation of a terminal including a step of storing failure related information when the terminal described in FIG. 15 fails to construct an additional radio resource through the second base station.

Referring to FIG. 17, the UE receives a first signal including information for additional radio resource configuration from the first base station and / or additional radio resource configuration indication information to the second base station (S1710).

The terminal performs an additional radio resource configuration via the second base station based on the first signal and performs a random access procedure with the second base station. As described above, the additional radio resource configuration and the random access procedure may be performed simultaneously or sequentially.

The UE can start a timer for additional radio resource configuration while performing additional radio resource configuration. If the timer expires before the additional radio resource configuration through the second base station has been successfully completed, the UE sends the failure related information to the VarRLF-Report or the second base station additional radio resource configuration failure report Can be stored in a new information element.

For example, if the UE transmits an additional radio resource configuration completion message (e.g., an RRC Connection Reconfiguration Complete message), the MAC successfully successfully uplinks the second base station, The terminal determines that the additional radio resource configuration has failed.

If the additional radio resource configuration is unsuccessful, the UE adds a new information element for the above-described VarRLF-Report or the second base station addition radio resource configuration failure report to the second signal (for example, the RRC Connection Reconfiguration Complete message) And transmits information indicating that the resource configuration has failed to the first base station (S1740).

That is, before the additional radio resource configuration through the second base station is successfully completed, the terminal expires the timer for limiting the additional radio resource configuration time of the terminal described above, so that the above-described VarRLF-Report or the second base station additional radio resource configuration And may transmit a second signal to the first base station if a new information element for the failure report is set.

The UE reconfigures / resets the radio resource configuration through the first base station before the first signal is received (S1750). That is, if the timer of the terminal expires before the additional radio resource configuration through the second base station is successfully completed, the terminal transmits an indication or failure indication to the second signal that the second base station add radio resource configuration failure information is available The first base station may be allowed to revert to the radio resource configuration previously used by the first base station.

An indication that the second base station add radio resource configuration failure information that may be included in the above-described second signal (e.g., an RRC connection reconfiguration complete message) is available is to use the existing rlf-InfoAvailable field (e.g., ENUMERATED {true}) . Alternatively, the existing rlf-InfoAvailable field may be extended (ENUMERATED {cause1, cause2}). Alternatively, it is possible to define and use a new field in which additional radio resource configuration failure information is available. As an example of a new field where additional radio resource configuration failure information is available, arrcf-InfoAvailable: additional radio resource configuration failure-infoAvailable (true) may be defined.

The second signal according to another embodiment of the present invention may include a radio resource connection reconfiguration failure message or an RRC connection reconfiguration recovery request message different from the radio resource connection reconfiguration complete message and the radio resource connection reset message, The message including the access attempt failure indication may include the additional radio resource configuration failure indication information or the RRC connection reconfiguration recovery request information or the random access attempt failure indication information by the additional radio resource configuration.

Specifically, for example, the UE displays a new information element for the above-described VarRLF-Report or the second base station addition radio resource configuration failure report or an indication that the second base station additional radio resource configuration failure information is available and / The failure indication information for the resource configuration may be transmitted to the first base station through another RRC message other than the RRC connection reconfiguration complete message.

For example, another RRC message may be an RRC Connection Setup Complete message UEInformationResponse or a ULInformationTransfer or an RRC Connection Re-establishment Complete message or a new RRC message.

As described above, the conventional RRC connection reconfiguration procedure considers the reconfiguration failure if the UE fails to comply with some of the configurations included in the RRC connection reconfiguration message received from the base station, and if the security is not activated, the RRC connection reconfiguration procedure (Leaving RRC_CONNECTED). When security is enabled, the RRC Connection re-establish procedure had to be initiated.

However, when the UE is performing normal data communication through the first base station, a connection failure to the second base station (e.g., a problem with the second base station random access or a downlink of the second base station serving cell Or when the second base station additional radio resource configuration failure occurs due to, for example, N310 consecutive out-of-sync indications in the physical layer of the second base station serving cell), the RRC Connection Reconfiguration failures can be inefficient.

That is, even if the UE fails in the configuration of the additional radio resource through the second base station, it can perform normal data communication through the first base station. Therefore, after the UE transitions from the RRC connection state to the RRC idle state, May be an unnecessary operation. In addition, in order to perform the RRC connection reset in response to the failure of the additional radio resource configuration through the second base station, all radio bearers other than SRB0 (Signaling Radio Bearer 0) are stopped, SCell is released, cell selection is resumed, Signaling Radio Bearer 1) and reconfiguring the DRB (Data Radio Bearer) according to the RRC connection reconfiguration procedure can be quite inefficient.

Therefore, the UE according to the present invention may include the failure indication information (or the RRC connection reconfiguration recovery request information (or the random access attempt failure indication information by the additional radio resource configuration) in the second signal, A new failure message may be defined for reporting a failure to the second base station add radio resource configuration.

The second signal according to the present invention may further include a radio resource connection reconfiguration failure message or an RRC connection reconfiguration message different from a radio resource connection reconfiguration complete message or a radio resource connection re- Additional radio resource configuration failure indication information or RRC connection reconfiguration recovery request information or random access attempt failure indication information by the additional radio resource configuration may be included in the message including the recovery request message or the random access attempt failure indication by the additional radio resource configuration .

The second signal according to the present invention may also be provided by MAC signaling indicating an additional radio resource configuration failure (or failure of a random access attempt by an RRC connection reconfiguration recovery request or an additional radio resource configuration) for fast processing.

For example, a new RRC failure message (e.g., a message including a radio resource connection reconfiguration failure message or a RRC connection reconfiguration recovery request message or a random access attempt failure indication by an additional radio resource configuration message) for a second base station additional radio resource configuration ), The UE can maintain the serving cell (s) of the existing first base station.

As another example, the UE can maintain the serving cell (s) of the existing first base station even when the UE performs the RRC connection re-establishment procedure due to the second base station add radio resource configuration failure. And a second base station additional radio resource configuration failure indication may be included in the reestablishment cause information of the RRC Connection re-establish request message.

If the first base station indicates that a new information element or a second base station additional radio resource configuration failure information is available for the above-described VarRLF-Report or the second base station addition radio resource configuration failure report, When receiving the second signal including at least one of the failure indication information, the first base station can release the preparation for the ongoing second base station additional radio resource configuration at the first base station. And the first base station may send a message (an offload cancel message) to cancel the preparation of the additional radio resource configuration in progress to the second base station.

17 and 18, a terminal according to the present invention performs a procedure for configuring an additional radio resource of a second base station, and a terminal operation when an additional radio resource configuration failure occurs is described in each embodiment .

Hereinafter, the operation of the terminal will be described in detail with reference to detailed embodiments when the above-described terminal of the present invention succeeds in configuring the additional radio resource of the second base station.

The terminal may succeed in establishing additional radio resources and random access with the second base station based on the first signal. In this case, the UE may transmit information on the success of the additional radio resource configuration to the first base station or the second base station.

First Detailed Embodiment: A method for transmitting an RRC Connection Reconfiguration Complete message to a first base station.

The UE can transmit an RRC Connection Reconfiguration Complete message to the first base station.

For example, when a Signaling Radio Bearer (SRB) for transmitting an RRC message is configured in a first base station and a second base station through a bearer-separated additional radio resource configuration as shown in FIG. 5, RRC Connection Reconfiguration Complete can be transmitted without distinguishing the uplink transmission channel of the base station.

As another example, if the Signaling Radio Bearer (SRB) for transmitting the RRC message is configured to be transmitted only through the first base station as shown in FIG. 6, the UE transmits RRC Connection Reconfiguration Complete to the first base station uplink transmission channel.

As another example, if the Signaling Radio Bearer (SRB) for transmitting an RRC message is configured to be transmitted only through the first base station as shown in FIG. 7, the UE can transmit an RRC Connection Reconfiguration Complete message to the first base station uplink transport channel with the SRB set .

The first base station receiving the RRC Connection Reconfiguration Complete message can forward it to the second base station. Or the first base station receiving the RRC Connection Reconfiguration Complete message may forward the success message for the additional radio resource configuration to the second base station.

5, when an SRB (Signaling Radio Bearer) is configured in a first base station and a second base station through an additional radio resource configuration separated as shown in FIG. 5, an RRC Connection Reconfiguration Complete message is transmitted through a second base station transmission channel The second base station can confirm the RRC Connection Reconfiguration Complete message to be forwarded to the first base station.

Alternatively, the second base station can confirm the success of the additional radio resource through a random access procedure or the like.

Second Detailed Embodiment: A method of transmitting an RRC Connection Reconfiguration Complete message to a second base station.

The MS may transmit an RRC Connection Reconfiguration Complete message to the second BS.

For example, when an SRB (Signaling Radio Bearer) for transmitting an RRC message is configured in the first and second base stations through an additional radio resource configuration separated from the bearer as shown in FIG. 5, the UE transmits RRC Connection Reconfiguration Complete can be sent.

As another example, even when the Signaling Radio Bearer (SRB) for transmitting the RRC message is configured to be transmitted only through the first base station as shown in FIG. 6, the UE transmits RRC Connection Reconfiguration Complete to the second base station uplink logical channel.

As another example, even when the Signaling Radio Bearer (SRB) for transmitting an RRC message is configured to be transmitted only through the first base station as shown in FIG. 7, the UE can transmit an RRC Connection Reconfiguration Complete message to the second base station uplink transport channel.

The second base station receiving the RRC Connection Reconfiguration Complete message can forward it to the first base station.

Third Detailed Embodiment: A method for transmitting an RRC Connection Reconfiguration Complete message to a first base station and a second base station, respectively.

The MS can transmit an RRC Connection Reconfiguration Complete message to the first BS and the second BS.

To this end, the first signal (for example, the RRC Connection Reconfiguration message) may include information for allowing the UE to transmit an RRC Connection Reconfiguration Complete message to each of the first and second base stations.

Information indicating that the UE transmits an RRC Connection Reconfiguration Complete message to each of the first base station and the second base station in a first signal (e.g., an RRC Connection Reconfiguration message), or information indicating an additional radio resource configuration The UE can transmit RRC Connection Reconfiguration Complete through the first BS uplink transport channel and the second BS uplink transport channel, respectively.

The first base station or the second base station may forward the received RRC Connection Reconfiguration Complete message to the second base station or the first base station.

Hereinafter, the operation of the base station when the additional radio resource configuration according to the present invention fails will be described with reference to the drawings.

18 is a flowchart illustrating an operation of a base station according to another embodiment of the present invention.

The method includes the steps of generating a first signal including information for further configuring a radio resource through a second base station, and transmitting the first signal to an upper layer Signaling, and receiving a second signal including additional radio resource configuration failure indication information from the terminal.

Referring to FIG. 18, a base station (a first base station) according to another embodiment of the present invention generates a first signal including information necessary for a terminal to additionally configure a radio resource of a second base station (S1810). As described above, the first signal is transmitted through upper layer signaling, and may further include additional radio resource configuration indication information through the second base station. Specific detailed embodiments of the additional radio resource configuration indication information are as described in detail with reference to Figs.

The first base station transmits the generated first signal to the terminal through higher layer signaling (S1820).

The terminal performs an additional radio resource configuration through the second base station based on the first signal and performs a random access procedure with the second base station. If the terminal successfully completes the additional radio resource configuration through the second base station and the random access procedure with the second base station, the first base station can receive a message including additional radio resource configuration completion information from the terminal. Various detailed embodiments in which the first base station receives additional radio resource configuration completion information are as described above.

However, if the terminal fails to complete the additional radio resource configuration or fails to complete the random access procedure with the second base station, the first base station may receive the second signal from the terminal (S1830 ).

The second signal includes a radio resource connection reconfiguration failure message (or an RRC connection reconfiguration recovery request message or random access attempt failure indication information by an additional radio resource configuration) distinct from the radio resource connection reconfiguration completion message and the radio resource connection reset message (Or RRC connection reconfiguration recovery request information or random access attempt failure indication information due to the additional radio resource configuration) in addition to the radio resource configuration failure indication information. Alternatively, the second signal may be sent via MAC signaling indicating an additional radio resource configuration failure of the terminal (or random access failure for additional radio resource configuration).

The first base station may resume the radio resource configuration with the terminal before the first signal is transmitted after receiving the second signal (S 1840).

For example, if the first base station transmits a first signal for setting a radio bearer using radio resources of the second base station as shown in FIGS. 5 to 7, if the terminal fails to construct an additional radio resource, It is possible to resume the configuration before the configuration of the radio bearer using resources and perform communication with the UE.

19 is another flow chart showing another embodiment of the operation of the base station according to another embodiment of the present invention.

The base station (first base station) according to another embodiment of the present invention may further include, after receiving the second signal, transmitting a message for canceling the additional radio resource configuration to the second base station.

Referring to FIG. 19, the first base station generates a first signal including additional radio resource configuration information using radio resources of the second base station (S1910).

As described with reference to FIG. 18, the first signal may further include additional radio resource configuration indication information and may be transmitted to the terminal through higher layer signaling (S1920).

If the terminal fails to construct an additional radio resource based on the first signal, the first base station receives the second signal from the terminal (S1930). The second signal may include additional radio resource configuration failure indication information and may be received via higher layer signaling.

Further, the second signal may include a radio resource connection reconfiguration failure message (or an RRC reconfiguration recovery request message or a random access attempt failure indication information by an additional radio resource configuration) different from the radio resource connection reconfiguration completion message and the radio resource connection reset message (E.g., a new message including the new message). That is, the second signal may be a newly defined radio resource connection reconfiguration failure message different from the existing message, or may include the corresponding message. Alternatively, the second signal may be sent via MAC signaling indicating an additional radio resource configuration failure of the terminal (or random access failure for additional radio resource configuration).

After receiving the second signal, the first base station may transmit a message to cancel the additional radio resource configuration to the second base station (S1940). In addition, the radio resource configuration with the terminal before the transmission of the first signal can be resumed and communication can be resumed. The step of step S1940 and the step of resuming the existing radio resource configuration may be performed simultaneously, or one of the steps may be performed in preference to the other step.

The second base station, which has received the message including information for canceling the additional radio resource configuration from the first base station, cancels all procedures for configuring the additional radio resources with the terminal.

As described above, according to the present invention, in the process of configuring additional radio resources that can be provided by a second base station to use radio resources provided by one or more different base stations connected through a non-ideal backhaul, The terminal and the first base station can resume the existing radio resource configuration and continue the communication even if additional radio resource configuration is not successful. Thereby, the terminal has an effect of not performing an unnecessary RRC connection resetting step or releasing the SRB except the SRB0 and releasing the SCELL.

A configuration of a terminal and a base station to which all of the embodiments of the present invention described with reference to Figs. 1 to 19 can be performed will be described with reference to the drawings.

20 is a diagram illustrating a configuration of a terminal according to another embodiment of the present invention.

Referring to FIG. 20, a user terminal 2000 according to another embodiment of the present invention includes a receiving unit 2010, a control unit 2020, and a transmitting unit 2030.

The terminal 2000 configuring a dual connection with a plurality of base stations of the present invention includes a receiving unit 2010 for receiving a first signal including information for additionally configuring radio resources from a first base station through a second base station, 1 signal and a random access with the second base station through the control unit 2020 attempting to construct additional radio resources via the second base station and random access with the second base station, The mobile station 200 may include a transmitter 2030 that transmits a second signal including additional radio resource configuration failure indication information to the first base station.

The control unit 2020 can control to resume the radio resource configuration via the first base station before receiving the first signal when the radio resource configuration through the second base station or the random access with the second base station fails.

Here, the radio resource configuration through the first base station includes a data radio bearer through the first base station before receiving the first signal as described above.

In addition, when the control unit 2020 fails to perform the additional radio resource configuration through the second base station or the random access with the second base station, the control unit 2020 transmits the second base station identification information related to the failure, the cell identification information associated with the second base station, To the radio link failure report or the second base station additional radio resource configuration failure report.

The receiving unit 2010 may receive the first signal through higher layer signaling, and the first signal may further include indication information indicating an additional radio resource configuration through the second base station.

The transmission unit 2030 may transmit the second signal through the upper layer signaling and the second signal may include a radio resource connection reconfiguration failure message distinguished from the radio resource connection reconfiguration completion message or the radio resource connection reconfiguration message or an RRC connection reconfiguration recovery request A message including a random access attempt failure indication by a message or an additional radio resource configuration may include the additional radio resource configuration failure indication information or the random access attempt failure indication information by the RRC connection reconfiguration recovery request or the additional radio resource configuration .

In addition, the receiving unit 2010 receives downlink control information, data, and messages from the base station through the corresponding channel.

In addition, the controller 2020 controls the terminal required to perform the above-described present invention to configure additional radio resources, and when it fails, the overall operation of the terminal due to the resumption of the radio resource configuration with the existing first base station .

The transmitter 2030 further transmits uplink control information, data, and a message to the base station via the corresponding channel.

21 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.

21, a base station 2100 according to another embodiment of the present invention includes a control unit 2110, a transmitting unit 2120, and a receiving unit 2130.

The first base station 2100 for controlling a dual connection configuration of a terminal according to the present invention includes a control unit 2110 for generating a first signal including information for further configuring a radio resource through a second base station, And a receiving unit 2130 for receiving a second signal including additional radio resource configuration failure indication information from the terminal.

After receiving the second signal, the controller 2110 can control to resume the radio resource configuration with the terminal before the transmission of the first signal. The radio resource configuration with the terminal before transmitting the first signal may include a data radio bearer (DRB) through the first base station before transmitting the first signal.

The transmitter 2120 may transmit the first signal through higher layer signaling and the first signal may further include indication information indicating an additional radio resource configuration through the second base station.

In addition, the transmitter 2120 may further transmit a message for canceling the additional radio resource configuration to the second base station after receiving the second signal.

The receiving unit 2130 may receive a second signal including additional radio resource configuration failure information from the UE, and the second signal may include a radio resource connection reconfiguration failure message distinguished from the radio resource connection reconfiguration completion message or the radio resource connection reset message The radio resource configuration failure indication (or RRC connection reconfiguration recovery request or random access attempt failure due to additional radio resource configuration indication) is added to the message (or RRC reconnection recovery request message or random access attempt failure indication message due to the additional radio resource configuration) Information).

In addition, the control unit 2110 controls the overall operation of the base station according to the resumption of the existing radio resource configuration when the control unit 2110 constructs additional radio resources to the terminal necessary to perform the above-described present invention.

The transmitting unit 2120 and the receiving unit 2130 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention to and from the terminal.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims

A method for a terminal to establish a dual connection with a plurality of base stations,
Receiving a first signal comprising information from a first base station to indicate an additional radio resource configuration via a second base station;
Starting a timer included in the first signal;
Attempting random access with the second base station; And
And when the timer expires, sending a second signal including additional radio resource configuration failure indication information to the first base station.

The method according to claim 1,
Wherein the first signal comprises:
Is received via upper layer signaling,
Wherein information for indicating an additional radio resource configuration via the second base station is received via a second base station MobilityControlInfo information element or a secondary cell group MobilityControlInfo information element.

The method according to claim 1,
And stopping the timer if a random access attempt with the second base station is successful.

The method according to claim 1,
When the timer expires,
Further comprising setting the additional radio resource configuration failure indication information in a connection failure type (connectionFailureType) information.

The method according to claim 1,
When the timer expires,
And stopping the data radio bearer configured in the second base station or the secondary cell group.

The method according to claim 1,
Wherein the second signal comprises:
The additional radio resource configuration failure indication information in an RRC message for reporting a second base station additional radio resource configuration failure or a secondary cell group radio link failure.

A method for a first base station to control a dual connection configuration of a terminal,
Receiving a first signal comprising information for indicating an additional radio resource configuration from a second base station via a second base station;
Transmitting the first signal to the terminal through higher layer signaling; And
And receiving a second signal from the terminal, the second signal including additional radio resource configuration failure indication information.

8. The method of claim 7,
The information for indicating the configuration of the additional radio resource through the second base station,
The second base station MobilityControlInfo information element or the secondary cell group MobilityControlInfo information element.

8. The method of claim 7,
Wherein the first signal comprises:
Further comprising a timer for detecting a second base station add radio resource configuration failure or a secondary cell group radio link failure.

8. The method of claim 7,
After receiving the second signal,
Transmitting an RRC connection reconfiguration message to the UE for resuming the radio resource configuration with the UE before transmitting the first signal; And
And resuming the radio resource configuration with the terminal before transmitting the first signal.

8. The method of claim 7,
Wherein the second signal comprises:
The additional radio resource configuration failure indication information in an RRC message for reporting a second base station additional radio resource configuration failure or a secondary cell group radio link failure.

delete

In a terminal constituting a dual connection with a plurality of base stations,
A receiving unit for receiving a first signal including information for indicating an additional radio resource configuration from a first base station through a second base station;
A control unit for starting a timer included in the first signal and attempting random access with the second base station; And
And a transmitter for transmitting a second signal including additional radio resource configuration failure indication information to the first base station when the timer expires.

14. The method of claim 13,
Wherein the first signal comprises:
Is received via upper layer signaling,
Information for indicating an additional radio resource configuration via the second base station,
A terminal received via a second base station MobilityControlInfo information element or a secondary cell group MobilityControlInfo information element.

14. The method of claim 13,
Wherein,
And stops the timer when a random access attempt with the second base station is successful.

14. The method of claim 13,
Wherein,
When the timer expires,
And setting the additional radio resource configuration failure indication information in a connection failure type (connectionFailureType) information.

14. The method of claim 13,
Wherein,
And stops the data radio bearer configured in the second base station or the secondary cell group when the timer expires.

14. The method of claim 13,
Wherein the second signal comprises:
And the additional radio resource configuration failure indication information in an RRC message for reporting a second base station additional radio resource configuration failure or a secondary cell group radio link failure.

A first base station for controlling a dual connection configuration of a terminal,
A receiving unit for receiving a first signal including information for indicating an additional radio resource configuration from a second base station via a second base station; And
And a transmitter for transmitting the first signal to the terminal through higher layer signaling,
Wherein the receiving unit further receives a second signal including additional radio resource configuration failure indication information from the terminal.

20. The method of claim 19,
The information for indicating the configuration of the additional radio resource through the second base station,
The second base station MobilityControlInfo information element or the secondary cell group MobilityControlInfo information element.

20. The method of claim 19,
Wherein the first signal comprises:
Further comprising a timer for detecting a second base station addition radio resource configuration failure or a secondary cell group radio link failure.

20. The method of claim 19,
The transmitter may further comprise:
Further transmitting an RRC connection reconfiguration message to the UE for resuming the radio resource configuration with the UE before the transmission of the first signal,
Further comprising a control unit for resuming a radio resource configuration with the terminal before transmitting the first signal.

20. The method of claim 19,
Wherein the second signal comprises:
And the additional radio resource configuration failure indication information in an RRC message for reporting a second base station additional radio resource configuration failure or a secondary cell group radio link failure.

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