KR20150129286A - Methods for transmitting data and Apparatuses thereof - Google Patents

Abstract

The present invention relates to a data transmission method and apparatus. More particularly, the present invention relates to a data transmission method and apparatus of a terminal in a case where a cell of a secondary base station in which dual connectivity is configured supports on-off state change. In particular, the present invention provides a method for transmitting data in a terminal, comprising the steps of: checking on-off state information of a primary secondary cell of a secondary cell group when uplink data transmission to a secondary cell group is triggered; And transmitting the trigger information based on the state information, wherein the terminal constitutes dual connectivity with two or more base stations, and the primary secondary cell is a cell having a PUCCH transmission function.

Description

[0001] The present invention relates to a method for transmitting data,

The present invention relates to a data transmission method and apparatus. More particularly, the present invention relates to a data transmission method and apparatus of a terminal in a case where a cell of a secondary base station in which dual connectivity is configured supports on-off state change.

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, a high-speed and large-capacity communication system capable of transmitting and receiving various data such as video and wireless data outside a voice- It is required to develop a technique capable of transmitting large-capacity data in accordance with the above-described method. It is possible to efficiently transmit data using a plurality of cells in a method for transmitting a large amount of data.

In such a situation, a technique of expanding a large number of small base stations having a relatively narrow coverage such as a small cell is discussed in order to transmit a large amount of data at a high speed and stably transmit and receive data in an environment in which a plurality of terminals are concentrated in a specific base station In fact. In such an environment where a small base station is deployed, the terminal can improve data processing speed by transmitting and receiving data and signals using a macro base station having a relatively wide coverage with a small base station.

However, since the coverage of the small base station is relatively narrow, it may happen that the terminal does not exist in a small cell at a specific time or at a specific location. Or the small cell may not be used depending on the necessity of data processing of the terminal. Even in such a case, operating the small cell has a problem in that power consumption is wasted throughout the system. Also, in an environment in which a plurality of small cells are deployed, a reference signal or the like increases, which may cause a problem of inter-cell signal interference.

In this context, the present invention proposes a specific procedure for transmitting data according to the state of a corresponding cell when a cell configured with Dual Connectivity is a cell supporting ON / OFF state change.

In addition, the present invention proposes a specific method of processing the trigger according to the cell state of the secondary cell group when the uplink data transmission to the secondary cell group of the terminal is triggered.

In particular, the present invention proposes a method in which a terminal processes trigger information for a secondary cell group through a master cell group when the primary secondary cell of the secondary cell group is in an off state.

According to another aspect of the present invention, there is provided a method for transmitting data in a terminal, the method comprising the steps of: determining whether uplink data transmission of a cell is possible if uplink data transmission to a cell included in a secondary cell group is triggered; And transmitting the trigger information based on whether or not the uplink data transmission of the cell is possible, wherein the terminal provides a method of configuring dual connectivity with two or more base stations.

According to another aspect of the present invention, there is provided a method of receiving data from a base station, the method comprising: configuring dual connectivity to a secondary base station and a terminal; receiving trigger information of uplink data from the terminal to a secondary base station; And transmitting processing information for processing the information.

According to another aspect of the present invention, there is provided a terminal for transmitting data, comprising: a controller for checking whether uplink data can be transmitted to a cell included in a secondary cell group when uplink data transmission is triggered; And a terminal for transmitting the trigger information based on whether or not the terminal is connected to the terminal, wherein the terminal provides a terminal device constituting dual connectivity with two or more base stations.

According to another aspect of the present invention, there is provided a base station for receiving data, the base station including: a control unit configuring dual connectivity to a secondary base station and a terminal; a receiving unit receiving trigger information of uplink data from the terminal to a secondary base station; And a transmitting unit for transmitting processing information for processing the base station.

The present invention has the effect of providing a specific procedure for transmitting data according to the state of a corresponding cell when a cell configured with Dual Connectivity is a cell supporting ON / OFF state change.

Also, the present invention provides a method of processing a trigger according to a cell state of a secondary cell group when uplink data transmission to a secondary cell group of the terminal is triggered, thereby providing an effect of preventing ambiguity of the terminal operation .

In addition, the present invention provides an effect that data transmission of a terminal can be smoothly performed even when a small cell supporting ON / OFF state change is configured with dual connectivity to the terminal.

1 is a view showing a small cell development according to an embodiment.
2 is a diagram showing a small cell deployment scenario.
3 to 6 are diagrams showing detailed scenarios in the small cell deployment.
7 is a diagram illustrating an example of a dual connectivity structure.
8 is a diagram showing another example of the dual connectivity structure.
9 is a diagram for explaining a contention-based random access procedure.
10 is a diagram for explaining a contention-based random access procedure.
11 is a diagram showing an example of a random access preamble.
12 is a diagram showing an example of a random access response.
13 is a diagram for explaining a terminal operation according to an embodiment of the present invention.
14 is a diagram for explaining operations of a terminal according to another embodiment of the present invention.
15 is a diagram for explaining operations of a terminal according to another embodiment of the present invention.
16 is a view for explaining a base station operation according to another embodiment of the present invention.
17 is a diagram illustrating a terminal configuration according to another embodiment of the present invention.
18 is a diagram illustrating a base station configuration 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 symbols as 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 user terminal in this specification is a comprehensive concept of a terminal in wireless communication. It is a comprehensive concept which means a mobile station (MS), a user terminal (UT), an SS (User Equipment) (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) the device itself providing a megacell, macrocell, microcell, picocell, femtocell, small cell in relation to the wireless region, or ii) indicating 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 base station, collectively referred to as a megacell, macrocell, microcell, picocell, femtocell, small cell, RRH, antenna, RU, low power node do.

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 transmission / reception point of a signal transmitted from a transmission / reception point, and a 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.

The present invention relates to the operation of a terminal when the terminal is configured with dual connectivity and the small cell constituting the dual connectivity supports on-off state change operation.

Hereinafter, the macrocell and the small cell in this specification are divided into a relative size of the coverage of the communicable cell, and the macrocell has a wider coverage than the small cell. Further, the macro cell and the small cell can be formed by respective base stations or transmission / reception points. In this specification, a base station providing a macro cell is described as a macro cell base station, a master base station or a MeNB, and a base station providing a small cell is described as a small cell base station, a secondary base station, or a SeNB. It is also assumed that the base station supporting on / off state change in the present specification is a base station providing a small cell, but the present invention is not limited thereto. The base station in this specification means MeNB or SeNB described above, and may mean either MeNB or SeNB, if necessary.

In a 3GPP LTE or LTE-Advanced system, a macro cell formed by a high power base station (eNB), a Coordinated MultiPoint (CoMP) system with a small cell formed by a low power RRH connected to a high- ) Various techniques for applying the technology can be defined. In addition, a heterogeneous network scenario in which a pico cell or a micro cell for supporting a hot spot or a coverage hole is formed by overlapping a macro cell, Various interference control techniques can be proposed. In addition, various communication methods using the small cell are being studied.

Hereinafter, a small cell deployment scenario to which the present invention is applicable will be described.

1 is a view showing a small cell development according to an embodiment.

FIG. 1 shows a configuration in which a small cell and a macro cell coexist. In FIGS. 2 to 3, the presence or absence of macro coverage, whether the small cell is for outdoor use or indoor use, , Whether the development of the small cell is sparse or dense, or whether the same frequency spectrum as the macro is used in terms of spectrum or not.

2 is a diagram showing a small cell deployment scenario. Figure 2 shows a typical representative configuration for the scenario of Figure 3; Fig. 2 shows a small cell deployment scenario and includes scenarios # 1, # 2a, # 2b, and # 3. 200 represents a macro cell, and 210 and 220 represent a small cell. The overlapping macrocells in FIG. 2 may or may not exist. Coordination can be performed between the macro cell 200 and the small cells 210 and 220 and adjustment can also be performed between the small cells 210 and 220. And the overlapping regions of 200, 210, and 220 can be clustered.

3 to 6 are diagrams showing detailed scenarios in the small cell deployment.

Fig. 3 shows scenario # 1 in the small cell expansion. Scenario 1 is a co-channel deployment scenario for small cells and macro cells in the presence of overhead macros and is an outdoor small cell scenario. 3 shows a case where both the macro cell 311 and the small cell are outdoors, and 312 denotes a small cell cluster. Users are distributed both indoors / outdoors.

The solid lines connecting the small cells in the small cell cluster 312 mean a backhaul link within the cluster. The dotted lines connecting the base station of the macro cell and the small cells in the cluster mean a backhaul link between small cells and macro cells.

Fig. 4 shows the small cell deployment scenario # 2a. Scenario 2a is a deployment scenario in which small cells and macros use different frequency spectra in the presence of an overlaid macro, and is an outdoor small cell scenario. Both the macro cell 411 and the small cells are outdoors and 412 indicates a small cell cluster. Users are distributed both indoors / outdoors.

The solid lines connecting the small cells in the small cell cluster 412 mean a backhaul link within the cluster. The dotted lines connecting the base station of the macro cell and the small cells in the cluster mean a backhaul link between small cells and macro cells.

5 shows the small cell deployment scenario # 2b. Scenario 2b is a deployment scenario in which the small cell and the macro use different frequency spectrum in the presence of the overlay macro and is an indoor small cell scenario. The macro cell 511 is outdoors, the small cells are all indoors, and 512 is a small cell cluster. Users are distributed both indoors / outdoors.

The solid lines connecting the small cells in the small cell cluster 512 mean a backhaul link within the cluster. The dotted lines connecting the base station of the macro cell and the small cells in the cluster mean a backhaul link between small cells and macro cells.

6 shows the small cell deployment scenario # 3. Scenario 3 is an indoor small cell scenario with no coverage of macros. 612 indicates a small cell cluster. In addition, the small cells are all indoor and users are dispersed both indoors and outdoors.

The solid lines connecting the small cells in the small cell cluster 612 mean a backhaul link within the cluster. The dotted lines connecting the base station of the macro cell and the small cells in the cluster mean a backhaul link between small cells and macro cells.

The frequencies F1 and F2 used in the various small cell scenarios of FIGS. 1 and 2 to 6 described above may be frequencies that support the same duplex mode, or F1 and F2 may have different duplex modes , For example, F1 may be considered to support FDD mode, F2 may be considered to support TDD mode, or vice versa.

<Small Cell Discovery ( Small cell discovery )>

A downlink synchronization for detecting an arbitrary cell formed by an arbitrary base station / an eNB / RU / RRH in a conventional 3GPP LTE / LTE-Advanced system, and a PSS (Primary Synchronization Signal) / SSS (Secondary Synchronization Signal) and CRS (cell specific reference signal). Accordingly, in a base station / eNB / RU / RRH constituting an arbitrary cell, FDD (Frequency Division Duplex) is performed according to a frame structure type (for example, TDD / FDD) SSS through the downlink subframe # 0 and # 5, and transmits the PSS / SSS through the downlink subframe # 1 and # 6 in case of TDD (Time Division Duplex) And transmits the CRS in the subframe.

However, there is a need for a small cell on / off operation in a small cell deployment scenario, and a discovery procedure related to the small cell on / off operation is required. Therefore, in addition to the PSS / SSS and CRS-based small cell discovery methods, a specific definition of a new small cell discovery procedure based on a new reference signal is required.

For further details regarding the corresponding small cell on / off and small cell discovery, refer to 3GPP TR 36.872 document. In this regard, the DL reference signal and SS (Synchronization Signal) related information defined in the 3GPP LTE / LTE-Advanced system are referred to the 3GPP TS 36.211 document.

Small Cell On / Off (On / Off)

As described above, when a plurality of small cells are overlapped with an arbitrary macro cell coverage, overall system throughput is increased through cell splitting gain. However, There are disadvantages such as an interference problem between a small cell and a macro cell which reduces the effect of the corresponding cell splitting gain, an increase in system power consumption and an increase in maintenance cost due to introduction of a plurality of base stations. In particular, even when there is no UE connected in the small cell coverage, the small cell base station / eNB / RU / RRH continuously transmits downlink signals including the PSS / SSS and the PBCH or CRS Therefore, unnecessary power consumption in the small cell base station / eNB / RU / RRH is caused, and unnecessary interference may occur in data transmission / reception in the adjacent cell.

In order to solve this problem, there is a need for a small cell on / off state changing operation for switching the state of the small cell base station to an off state / state according to the number of terminals connected to the small cell or the presence or absence of the terminal It is being raised. The small cell on / off state change operation can be performed for intercell interference adjustment and avoidance, load balancing, and energy saving in a dense mall cell deployment environment.

For example, when the small cell is turned on, the small cell may transmit signals that the terminal needs to receive data from the cell. For example, a small cell in an ON state can transmit signals transmitted in a normal cell (for example, a cell prior to 3GPP Release-12) in the same manner. That is, the small cell can transmit CSI, SI, and the like.

If the small cell is turned off, the small cell may not transmit signals that the terminal needs to receive data from the cell. For example, the small cell in an off state may not transmit some or all of the signals transmitted in a normal cell (e.g., a cell prior to 3GPP Release-12). However, it is necessary to transmit signals for small cell detection and measurement when the small cell is turned off. Hereinafter, the signal transmitted by the small cell in the off state for the detection or measurement of the small cell is referred to as a discovery reference signal (DRS).

Meanwhile, the on / off state of the small cell can be determined according to the traffic load of the corresponding cell, the arrival / departure of the user, the packet arrival / completion, and the like.

Activation / deactivation of cells

In a single base station based Carrier Aggregation (CA) technology or a dual connectivity based on multiple base stations, a small cell may be composed of an additional serving cell or a secondary cell. When a small cell is composed of an additional serving cell or a secondary cell in the UE, an RRC Connection Reconfiguration procedure can be used. When a small cell is configured as an additional serving cell or a secondary cell by a base station, the UE configures the corresponding additional serving cell or secondary cell to be in a deactivated state in a lower layer (UE configure lower layers to consider the SCELL to be in deactivated state.

Therefore, in order to use the DL Component Carrier and / or the UL Component Carrier of the secondary cell, the additional configured secondary cell must be activated. That is, in order to efficiently manage the battery of the terminal, it is necessary to perform an activation step, which is different from the secondary cell addition or secondary base station addition step, in order for the terminal to further configure the secondary cell.

Activation and deactivation of the secondary cell is performed through a Medium Access Control (MAC) signal. The UE can perform only reference signal received power (RSRP) or reference signal reception quality (RSRQ) measurement without performing CSI (Channel State Information) measurement on the inactivated secondary cell. Through this, it is possible to effectively manage power consumption of the terminal by blocking the execution of CSI measurement which requires a lot of power consumption. Transmission to the uplink element carrier is also disabled for the secondary cell in the inactive state. Since the base station does not schedule the PUSCH for the disabled secondary cell, SRS (Sounding Reference Signal) is not transmitted to the corresponding cell.

When the secondary cell is deactivated, the UE does not transmit the SRS to the secondary cell (not transmit SRS on the SCell) and not to the secondary cell's UL-SCH (not transmit on the UL-SCH on the SCell) A channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and a procedure transaction identifier (PTI) report for a secondary cell are not transmitted on the RACH of the secondary cell (Not report the CQI / PMI / RI / PTI for the SCell), but not the secondary cell (not monitor the PDCCH on the SCell) and not perform the PDCCH monitoring for the secondary cell PDCCH for the SCell).

When the secondary cell is activated, normal secondary cell operation (SRS transmissions on the SCell, CQI / PMI / RI / PTI reporting for the SCell, PDCCH monitoring on the SCell and PDCCH monitoring for the SCell) are performed. For example, when the secondary cell is activated, the terminal transmits SRS to the secondary cell, transmits CQI / PMI / RI / PTI to the secondary cell, monitors the PDCCH to the secondary cell, and performs PDCCH monitoring for the secondary cell can do.

Dual  Connectivity ( Dual Connectivity )

Dual connectivity means an operation in which an RRC CONNECTED terminal uses radio resources provided by at least two different network points (e. G., A Master eNB and a Secondary eNB) connected in a non-ideal back haul. In a dual connectivity, a master eNB refers to a base station that terminates the S1-MME and operates as a mobility anchor toward a core network (CN). The master base station may be referred to as a MeNB or a Macro eNB or a macrocell eNB. In dual connectivity, a secondary eNB represents a base station that provides additional radio resources for a terminal, not a master base station. The secondary eNB may be referred to as an SeNB or a small cell eNB or a Small eNB or an assisting eNB. At this time, a group of serving cells associated with MeNB is referred to as a MCG (Master Cell Group), and a group of serving cells associated with SeNB is referred to as a secondary cell group (SCG).

SeNB has at least one special SCell (hereinafter referred to as Primary Secondary Cell (PSCell)) including a PUCCH transmission / reception function. That is, at least one cell in the SeNB constitutes an uplink, and one cell constituting the uplink is configured with a PUCCH resource (at least one cell in the SeNB has been configured as UL and one of them is configured with PUCCH resources ).

In dual connectivity, the serving cells of an MCG other than a PCell may be enabled / disabled by a MAC Control Element received on the MCG. And the serving cells of the SCG other than the particular SCell may be activated / deactivated by a MAC control element received on the SCG. The special SCell in the SCG is always activated like PCell. (In DC, the serving cells of the MCG other than the PCs can only be activated / deactivated by a MAC Control Element received on the MCG, and the serving cells of the SCG other than the special SCell can only activated / deactivated by a MAC Control Element received on SCG. The SCG is always activated like the PCell.

The UE must perform Radio Link Monitoring (RLM) on a special SCell to detect Layer 1 (L1) out-of-sync. The UE shall report the SCL Radio Link Failure (RLF) triggered by the RLM to the master base station (UE shall report S-RLF to MeNB triggered by RLM). The UE shall suspend the UL transmissions to the SCG for the Secondary Radio Link Failure (S-RLF) (S-RLF).

Dual connectivity supports an SCG bearer that transmits data only through a secondary base station. Therefore, in order to configure the dual connectivity for the small cell that provides the on-off function, the small cell is maintained in the ON state or the small cell in the OFF state is turned on through the dual connectivity configuration procedure (SCG addition / modification) . And, the small cell made up of dual connectivity to the terminal had to remain on until it was released.

7 is a diagram illustrating an example of a dual connectivity structure.

Referring to FIG. 7, an example of a dual connectivity structure using radio resources provided by two base stations (MeNB and SeNB) connected with a non-ideal backhaul can be seen. When the dual connectivity is configured in the UE with the structure shown in FIG. 7, the UE can configure a specific data radio bearer as a bearer dedicated for a specific base station. For example, the UE may configure a specific radio bearer for voice service as a MeNB dedicated data radio bearer and a specific radio bearer for Internet service as a SeNB dedicated data radio bearer.

8 is a diagram showing another example of the dual connectivity structure.

Referring to FIG. 8, another example of a dual connectivity structure using radio resources provided by two base stations (MeNB and SeNB) connected with non-ideal backhaul can be seen. 8, if the UE has dual connectivity, the UE can configure a specific data radio bearer through two base stations (MeNB and SeNB). For a specific data radio bearer, each base station has an independent RLC entity (MeNB is MeNB RLC entity, SeNB is SeNB RLC entity) and MAC entity (MeNB is MeNB MAC entity and SeNB is SeNB MAC entity).

Schedule  request( Scheduling Request , SR)

When the UE generates data to be transmitted in the uplink, the UE requests a radio resource from the BS. In order to request a radio resource, if the radio resource for Scheduling Request (SR) is allocated to the PUCCH, the mobile station transmits the SR to request the base station. If a PUCCH resource for SR is not allocated, the UE performs a random access procedure.

Random Access Procedure ( Random Access Procedure )

A random access procedure refers to a procedure that a UE uses to uplink time synchronization with a BS or to allocate radio resources.

The terminal performs a random access procedure in the following cases.

- In case of initial connection because there is no RRC connection (RRC connection) with the base station

- When attempting to recover from a wireless connection failure or handover failure

- When the terminal first accesses the target cell during the handover process

- When the uplink time synchronization is not appropriate or when a request for a radio resource (UL grant)

- when requested by the base station

Such a random access procedure is divided into a contention based random access procedure and a non-contention based (contention free) random access procedure. The division of the two schemes described above is determined depending on whether the terminal has selected a random access preamble (Random Access Preamble) used in the random access procedure or a base station.

9 is a diagram for explaining a non-contention-based random access procedure.

9, the UE 909 uses a preamble allocated only to itself by the base station 900 in a non-contention based (Contention Free) random access procedure. That is, the BS 900 allocates a preamble to be used for the non-contention-based random access by each MS 909 (S610). The preamble allocated to each terminal 909 can not be used by other terminals, so no collision occurs.

In step S920, the UE 909 transmits a random access preamble to the Node B 900 using the preamble allocated when the random access procedure described above is performed. When receiving the random access preamble, the base station 900 transmits a random access response to the corresponding terminal 909 (S930). Upon receiving the random access response, the UE 909 adjusts the uplink time synchronization using a TAC (Timing Advance Command) included in the random access response and transmits uplink data to the corresponding resource according to the UL grant By doing so, the random access procedure is terminated.

10 is a diagram for explaining a contention-based random access procedure.

Referring to FIG. 10, in the contention-based random access procedure, the UE 1009 selects and transmits an arbitrary preamble among usable preambles (S1010). In this case, since the terminal 1009 arbitrarily selects the random access preamble, there is a possibility that the terminal 1009 is simultaneously selected and used by a plurality of terminals. Therefore, when the base station 1000 receives an arbitrary random access preamble, it can not know from which terminal the corresponding random access preamble is transmitted. Therefore, unlike the non-contention-based random access procedure, an additional process is required to select only one UE. Hereinafter, the contention-based random access procedure will be described in the order of FIG.

One. First, the UE 1009 selects one random access preamble from among the set of random access preambles set through the received system information, selects and transmits a PRACH resource capable of transmitting the selected random access preamble (S1010). The settings for the PRACH resource are provided through the system information. The PRACH resource can be determined at which period in which subframe is allocated through the PRACH Configuration Index of the system information block 2.

2. The base station 1000 transmits a response message to one of the received random access preambles (S1020). The random access response is carried in the random access response window conveyed through the system information. The random access response message may include a random access preamble ID, an UL grant, a Temporary C-RNTI (Temporary C-RNTI), and an uplink time synchronization correction value (Time Alignment Command).

If the terminal 1009 receives a random access response corresponding to the random access preamble transmitted by the terminal 1009, the terminal 1009 sets the contents included in the random access response. For example, the UE 1009 applies the TAC and sets the temporary C-RNTI included in the random access response message to its temporary C-RNTI. And prepares to transmit the message through the received uplink radio resource. At this time, the other terminals that have transmitted the same random access preamble through the same PRACH resource also receive the random access response, apply the above setting, and transmit Msg3 together.

3. The terminal 1009 transmits Msg3 through the received radio resource to the received temporary C-RNTI (S1030). The Msg3 includes information unique to the terminal such as a UE-Identity.

4. The base station 1000 prepares a response message for one Msg3 received from the terminal 1009 and successfully decoded. (Contention Resolution ID = ue-Identity) included in the Msg3, and transmits the Msg4 to the temporary C-RNTI (S1040).

5. Upon receiving the response message Msg4, the terminal 1009 compares the unique identifier included in the Msg4 with its own unique identifier, and if it is the same, the terminal 1009 regards the response message as a response of the Msg3 transmitted by itself and transmits an ACK to the base station 1000 S1050). If the unique identifier included in the received Msg4 is not the same as its own unique identifier, the terminal determines that the random access procedure has failed and starts the random access procedure again from the beginning.

Through the above process, it is possible to avoid collision of a plurality of UEs transmitting the same random access preamble through the same PRACH resource in the contention-based random access procedure.

Random Access Preamble

11 is a diagram showing an example of a random access preamble.

Referring to FIG. 11, a random access preamble used in the random access procedure will be briefly described.

A total of 64 random access preambles can be distinguished. A non-dedicated random access preamble 1100 and a dedicated random access preamble 1110 are distinguished from each other. The non-dedicated random access preamble 1100 is a set of preambles usable in a contention-based random access procedure. Also, the dedicated random access preamble 1110 is a set of preambles used in a non-contention-based random access procedure. The non-dedicated random access preambles 1100 are divided into Group A and Group B. [ Group A and Group B are divided in accordance with the size of the message 3 (Msg3) and the path loss in the random access procedure. The BS allocates the number and types of preambles that can be used by the UE in advance according to the system information block 2 (SIB2).

Random Access Response ( Random Access Response )

12 is a diagram showing an example of a random access response.

Referring to FIG. 12, a random access response used in the above-described random access procedure will be briefly described.

The terminal that transmitted the random access preamble generates the RA-RNTI according to the PRACH resource that transmitted the random access preamble. The UE monitors the reception of the random access response during the random access response window (RAR window) time preset via the SIB2 from three subframes after the subframe in which the random access preamble is transmitted. At this time, the UE monitors the reception of the random access response using the RA-RNTI described above. If the UE receives the random access response message in the response window, it adjusts its uplink time synchronization according to the TAC included in the random access response message, sets the temporary C-RNTI to its own RNTI, -RNTI to prepare to transmit the above-described Msg3 according to the uplink grant.

According to the above description, the terminal can perform the SR transmission or the random access procedure when the uplink data transmission is triggered. However, as described above, there may arise a case where the UE constructs dual connectivity with cells of different base stations or different base stations. In addition, the terminal can configure dual connectivity with a small cell that performs the above-described on-off state change operation.

In such a case, the small cell constituting the dual connectivity of the terminal can be turned off. When the UE generates data to be transmitted to the small cell dedicated radio bearer in the off state, the UE must make a radio resource request to the small cell for data transmission. However, since the small cell is off, the UE can not transmit the radio resource request. Therefore, the terminal can not transmit the corresponding data or there is a problem that an unexpected delay occurs in transmission of the corresponding data.

In order to solve such a problem, when the generation of data to be transmitted to the primary secondary cell is triggered when the primary secondary cell (PSCell) of the SCG is in the off state, the terminal transmits the trigger information to the MeNB, It is possible to prevent a delay of one data from occurring.

Hereinafter, operations of the terminal and the base station of the present invention will be described in detail with reference to the drawings.

13 is a diagram for explaining a terminal operation according to an embodiment of the present invention.

When a scheduling request (SR) or a random access attempt is triggered in the SCell, the UE of the present invention determines whether uplink data transmission of the corresponding SCell is possible. Whether or not uplink data can be transmitted can be determined based on whether a radio resource for performing a corresponding operation is allocated to a cell in which the corresponding scheduling request or random access attempt is triggered. If a radio resource for a scheduling request or a random access attempt is allocated in a corresponding cell, the UE can perform an operation triggered through the corresponding cell. On the other hand, when no radio resource for a scheduling request or a random access attempt is allocated in the corresponding cell, the UE can transmit trigger information through the PSCell of the SCG including the SCell. Alternatively, the terminal may transmit the trigger information through the PCG of the MCG.

As another example, the operation of checking whether or not uplink data can be transmitted may refer to an operation of determining whether the resource is not occupied by SRAM or RACH due to resource use of another RAT in the license-exempt band. That is, if the UE requires a radio resource in order to perform a scheduling request or a random access attempt for uplink data transmission, the UE determines that the UE can not perform the above-described operation when the UE is occupied by another RAT in the unlicensed band.

On the other hand, the UE can determine whether to perform a trigger operation of the corresponding cell by checking on / off state information of the cell for which the uplink data is requested to be triggered. For example, if the corresponding SCell is on and off, and if the SCell is off, the trigger information can be transmitted through the PSCell of the SCG containing the SCell or the PCell of the MCG. Hereinafter, a case where the triggered cell is the PSCell will be described for the sake of clarity. However, even when the triggered cell is SCell as described above, the following explanation operation can be similarly applied.

The UE of the present invention can transmit information informing the uplink data trigger of the SCG to the MeNB when an SR transmission or a random access attempt in the SCG is triggered when the small cell in the off state configured with dual connectivity is PSCell.

Referring to FIG. 13, when the uplink data transmission for a cell included in the secondary cell group is triggered, the UE determines whether uplink data transmission is possible, And transmitting the trigger information based on the trigger information. Here, the terminal can configure dual connectivity with two or more base stations.

For example, when the uplink data transmission to the secondary cell group is triggered, the terminal of the present invention includes checking the on / off state information of the primary secondary cell of the secondary cell group (S1310). As described above, the UE may form a dual connectivity with two or more base stations, and a primary secondary cell (PSCell) having a PUCCH transmission function in the secondary cell group (SCG) may support on-off state change support. In this case, if the uplink data transmission to the secondary cell group is triggered from the upper layer, the terminal must transmit an SR transmission or a random access attempt for uplink data transmission through the primary secondary cell. However, when the primary secondary cell is in an OFF state, an SR transmission or a random access attempt is impossible. Accordingly, when the uplink data transmission to the secondary cell group is triggered, the terminal of the present invention can confirm the on / off state information of the primary secondary cell. For example, when the uplink data transmission is requested, the UE can determine whether the primary secondary cell is on or off. In another example, the MS may determine whether the primary secondary cell is on or off when an SR transmission or a random access attempt is required.

Thereafter, the terminal includes a step of transmitting trigger information based on on / off state information of the cell (S1320). For example, the UE can transmit trigger information to the secondary base station (SeNB) or the master base station (MeNB) according to the on / off state information of the primary secondary cell. Here, SeNB denotes a base station that provides a secondary cell group, and MeNB denotes a base station that provides a master cell group. SeNB and MeNB are base stations that form dual connectivity with the terminal.

For example, when the primary secondary cell is on, the terminal may transmit the SR as trigger information, or may transmit a random access preamble for a random access attempt to the SeNB.

As another example, when the primary secondary cell is in the OFF state, the UE can transmit information related to the SR or random access attempt according to the trigger of the uplink data in the secondary cell group to the MeNB with the trigger information. That is, since the primary secondary cell is in the off state, the SR can not transmit the SR or the random access attempt to the SeNB, so the UE can transmit the trigger information to the MeNB.

As another example, when the primary secondary cell is in an off state, the UE can transmit information indicating the uplink data generation of the SCG to the MeNB as trigger information.

The above trigger information may be the SR of PCell or the random access preamble transmission attempt. Or, if there is an uplink resource, it may be a BSR (Buffer Status Report) of the SCG. Alternatively, it may be newly defined instruction information or message. The newly defined message may include trigger cause information, bearer information, and the like.

Meanwhile, the MeNB receiving the trigger information can change the corresponding radio bearer to MeNB through the RRC Connection Reconfiguration procedure so that the UE can transmit the data to be transmitted to the SeNB to the MeNB. Alternatively, the MeNB receiving the trigger information may transmit a SeNB status change message to the SeNB for changing the SeNB to the ON status so that the terminal can transmit data to the SeNB.

The operation of the terminal of the present invention has been described above. The operation of the terminal when the PSCell of the present invention is in an off state will be described in detail with reference to FIGS. 14 and 15.

14 is a diagram for explaining operations of a terminal according to another embodiment of the present invention.

When the SR transmission or the random access transmission attempt is triggered in the secondary cell group, the MS of the present invention checks the on / off state information of the primary secondary cell and notifies the uplink data trigger of the SCG to the PCell of the MeNB Trigger information is transmitted.

The operation of each step will be described with reference to Fig.

One. The terminal triggers an SR transmission or a random access attempt in the secondary cell group (hereinafter referred to as SCG) (S1400). For example, the UE triggers an SR transmission in the SCG in order to request an uplink grant (UL grant) for uplink data transmission in the SCG. Alternatively, the terminal triggers a random access attempt in the SCG in the following cases.

- If the uplink time synchronization of the SCG is not correct

- In case of requesting uplink grant for uplink transmission in SCG

2. When an SR transmission or a random access attempt is triggered in the SCG, the UE confirms the on / off state of the PSCell (S1410). The PSCell may be configured to be included in the SCG with dual connectivity to the terminal as described above in support of the on-off state change.

3-1. If the PSCell is on, the terminal performs an SR transmission or a random access attempt triggered by the corresponding PSCell cell (S1420). If SR transmission is triggered and a radio resource for SR is not allocated to the PUCCH of the PSCell, the UE can transmit the random access preamble to the PSCell according to the SeNB random access setting received from the MeNB. That is, the UE can transmit an SR or a random access preamble to the SeNB as the trigger information.

3-2. If the PSCell is off, the MS transmits trigger information indicating that an SR transmission or a random access attempt has been triggered in the SCG to the PCell of the MeNB (S1430).

For example, the trigger information transmitted to the MeNB includes at least one of cell identification information, cell index information, secondary cell group identification information, and cause information triggered by uplink data transmission for the cell in which the uplink data transmission is triggered can do. Specifically, the trigger information may include information on whether the triggered transmission is an SR transmission or a random access preamble transmission according to a random access attempt. Or trigger information may include the cell ID or SCell index (SCellIndex) value or SCG ID information on which the transmission was triggered. Or trigger information may include information about the cause (e.g., DL / UL data arrival, time synchronization, etc.) that the transmission was triggered.

The trigger information described above may be transmitted via higher layer signaling (e.g., an RRC message).

As another example, the trigger information transmitted to the MeNB may include indication information indicating that a scheduling request or a random access request has been triggered in the secondary cell group. That is, the trigger information may be included in the PCell as an indication that it has been triggered in the SCG in an SR transmission or a random access transmission.

As another example, the trigger information described above may be transmitted using resources for the corresponding SCG SR by separately setting the SCG SR in the PUCCH in the PCell.

As another example, the trigger information may be transmitted via a dedicated random access preamble indicating the request triggered in the SCG.

As another example, in the random access procedure, the UE may include information such as an indication of a triggered request in the SCG, a triggered cell ID, and the like in Msg3.

On the other hand, the MeNB receiving the trigger information can change the corresponding bearer to the MeNB through the RRC connection reconfiguration procedure so that the UE can transmit the data to be transmitted to the SeNB to the MeNB.

Or the MeNB receiving the trigger information may transmit a SeNB status change message to the SeNB for changing the SeNB to the ON status. The SeNB status change message may include information that an SR transmission or a random access attempt has been triggered in the SCG of a terminal. Upon receiving the SeNB state change message, the SeNB can change its state to ON and inform the UEs of the ON state change. Or the MeNB that transmitted the SeNB status change message may notify the corresponding terminal that the SeNB is changed to the ON status.

15 is a diagram for explaining operations of a terminal according to another embodiment of the present invention.

When the ON / OFF state information of the PSCell described above is in the OFF state, the terminal of the present invention confirms the change of the ON / OFF state information of the cell according to a preset cycle. When the ON / OFF state information of the cell is changed to the ON state, Trigger information can be transmitted to the head secondary cell. In this case, the trigger information may be an SR or a random access preamble. For example, if an SR transmission or a random access attempt is triggered in the SCG, it can be checked whether the PSCell of the SCG is on or off. When the PSCell is in the off state, the UE periodically checks until it is in the on state, and performs the SR transmission or the random access procedure when it is in the on state.

Each step will be described in detail with reference to Fig.

One. If the UE requests an uplink grant for uplink data transmission in the SCG, the UE triggers the SR transmission in the SCG (S1500). Or the UE triggers a random access attempt in the SCG if (S1500).

- If the uplink time synchronization of the SCG is not correct

- When the SCG requests an uplink grant for uplink data transmission

2. When an SR transmission or a random access attempt is triggered in the SCG, the UE confirms the on / off state of the PSCell (S1510). That is, the UE confirms whether the PSCell having the PUCCH transmission function is on in the SCG.

3. If the PSCell is on, the terminal performs an SR transmission or a random access attempt triggered to the cell (S1520). If the SR transmission is triggered and the radio resource for SR is not allocated to the PUCCH of the PSCell, the UE transmits the random access preamble to the PSCell.

4. If pSCell is off, the terminal waits for the triggered request and continues to check if the PSCell is changed to the on state (S1510). If the PSCell changes to the on state, the terminal performs the triggered SR transmission or random access attempt. If the SR transmission is triggered and the radio resource for SR is not allocated to the PUCCH of the PSCell, the UE transmits the random access preamble to the PSCell.

Through the above-described embodiments, ambiguity of the terminal operation can be prevented when the PSCell supporting the on / off state change under the dual connectivity is in the off state.

The present invention described above will be described in terms of a base station. The base station described below is MeNB described above.

16 is a view for explaining a base station operation according to another embodiment of the present invention.

The base station according to another embodiment of the present invention includes a step of configuring dual connectivity to the secondary base station and the terminal, receiving trigger information of uplink data from the terminal to the secondary base station, and processing trigger information with the terminal or the secondary base station And transmitting the processing information for the first time.

Referring to FIG. 16, the base station includes a step of configuring dual connectivity to the secondary base station and the terminal (S1610). For example, the base station can configure dual connectivity to the SeNB and the terminal. In this case, the dual connectivity can be configured with the structure of Fig. 7 or Fig.

The base station may include receiving trigger information of uplink data for the secondary base station from the terminal (S1620). For example, if an SR transmission or a random access attempt is triggered in the SCG of the UE, the UE may transmit the trigger information to the Node B if the PSCell is off. That is, the trigger information can be received when the primary secondary cell of the secondary base station is in the off state.

The trigger information described above may be received via higher layer signaling (e.g., an RRC message).

As another example, the trigger information may include indication information indicating that a scheduling request or a random access request has been triggered in the secondary cell group. That is, the trigger information may be included in the PCell as an indication that it has been triggered in the SCG in an SR transmission or a random access transmission.

As another example, the trigger information may be received using a resource for the corresponding SCG SR by separately setting SCG SR in the PUCCH in the PCell. That is, the trigger information can be received through the PUCCH resource of the PCell allocated to receive the SR of the secondary base station.

As another example, the trigger information may be received via a dedicated random access preamble indicating a request triggered at the SCG. That is, the trigger information may be received through a dedicated random access preamble set for the random access request of the secondary base station.

As another example, in the random access procedure, the base station may receive Msg 3 including information indicating an indication of a triggered request in the SCG, a triggered cell ID, and the like.

Meanwhile, the base station may include a step of transmitting processing information for processing the trigger information to the terminal or the secondary base station (S1630). For example, the base station may transmit upper layer signaling including bearer change information for changing the radio bearer to which the uplink data is transmitted to the base station. The bearer change procedure can be performed through the RRC connection reconfiguration procedure. Or bearer change information may be included in the RRC connection reconfiguration message and transmitted. In another example, the base station may send a state change message to the secondary base station to change the PSCell in the off state to the on state.

As described above, the present invention provides a concrete procedure for transmitting data according to a state of a corresponding cell when a cell configured with Dual Connectivity is a cell supporting ON / OFF state change. Also, the present invention provides a method of processing a trigger according to a cell state of a secondary cell group when uplink data transmission to a secondary cell group of the terminal is triggered, thereby providing an effect of preventing ambiguity of the terminal operation . In addition, the present invention provides an effect that data transmission of a terminal can be smoothly performed even when a small cell supporting ON / OFF state change is configured with dual connectivity to the terminal.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a configuration of a terminal and a base station to which the present invention can be fully performed will be described with reference to the drawings.

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

Referring to FIG. 17, a user terminal 1700 according to another embodiment of the present invention includes a controller (not shown) for confirming uplink transmission of a cell when uplink data transmission to a cell included in a secondary cell group is triggered 1710 for transmitting the trigger information, and a transmitter 1720 for transmitting the trigger information based on the on / off state information of the cell.

If the cell does not receive a scheduling request or a radio resource for a random access attempt, or if the on / off state information of the cell is in an off state, the transmitter 1720 transmits the trigger information to another cell (for example, Primary cell). The trigger information described above may be transmitted via higher layer signaling (e.g., an RRC message). As another example, the trigger information transmitted to the MeNB may include indication information indicating that a scheduling request or a random access request has been triggered in the secondary cell group. That is, the trigger information may be included in the PCell as an indication that it has been triggered in the SCG in an SR transmission or a random access transmission. As another example, the trigger information described above may be transmitted using resources for the corresponding SCG SR by separately setting the SCG SR in the PUCCH in the PCell. As another example, the trigger information may be transmitted via a dedicated random access preamble indicating the request triggered in the SCG. As another example, in the random access procedure, the UE may include information such as an indication of a triggered request in the SCG, a triggered cell ID, and the like in Msg3.

Alternatively, the control unit 1710 can control the configuration of dual connectivity with two or more base stations.

Alternatively, when the ON / OFF state information of the cell is in the OFF state, the controller 1710 can confirm the change of the ON / OFF state information of the cell according to a preset cycle. In this case, the transmitter 1720 can transmit the trigger information to the primary secondary cell when the ON / OFF state information of the cell is changed to the ON state.

The receiver 1730 receives downlink control information, data, and messages from the base station through the corresponding channel.

In addition, when the terminal required to perform the above-described present invention transmits information informing MeNB of the generation of data to be transmitted to the PSCell when the PSCell of the SCG is in the off state, the control unit 1710 suspends the trigger at a predetermined period It is possible to control all operations of the terminal 1700 as a whole.

In addition, the transmitter 1720 transmits uplink control information, data, and a message to the base station through the corresponding channel.

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

18, a base station 1800 according to another embodiment of the present invention includes a control unit 1810 for configuring dual connectivity to a secondary base station and a terminal, and a control unit 1810 for receiving trigger information of uplink data for a secondary base station from the terminal And a transmitter 1820 that transmits processing information for processing the trigger information to the receiver 1830 and the terminal or the secondary base station.

Trigger information received by the base station may be received via higher layer signaling (e.g., an RRC message). As another example, the trigger information may include indication information indicating that a scheduling request or a random access request has been triggered in the secondary cell group. That is, the trigger information may be included in the PCell as an indication that it has been triggered in the SCG in an SR transmission or a random access transmission. As another example, the trigger information may be received using a resource for the corresponding SCG SR by separately setting SCG SR in the PUCCH in the PCell. In other words, the trigger information may be received via a dedicated random access preamble indicating a request triggered in the SCG . That is, the trigger information may be received through a dedicated random access preamble set for the random access request of the secondary base station. As another example, in the random access procedure, the receiver 1830 may receive Msg 3 including information such as an indication of a triggered request in the SCG, a triggered cell ID, and the like.

The transmitter 1820 may transmit bearer change information for changing the radio bearer to which the uplink data is transmitted to the base station. The bearer change information may be transmitted via higher layer signaling. In one example, the bearer change information may be included in the RRC connection reconfiguration message.

Alternatively, the transmitting unit 1820 may transmit state change information for changing the PSCell to the ON state to the secondary base station.

In addition, the control unit 1810 can control operations required for configuring the dual connectivity to the secondary base station and the terminal.

In addition, the controller 1810 controls the overall operation of the base station 1800 according to the notification of the generation of data to be transmitted to the PSCell when the PSCell of the SCG is in the off state, .

The transmission unit 1820 and the reception unit 1830 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention to and from the terminal.

The standard content or standard documents referred to herein constitute a part of this specification, for the sake of brevity. It is therefore to be understood that the scope of the present invention is to be interpreted as adding to the scope of the appended claims or the content of some of the standard content and standard documents herein.

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 (22)

A method for a terminal to transmit data,
Confirming whether or not uplink data transmission of the cell is possible if uplink data transmission for a cell included in the secondary cell group is triggered; And
Transmitting the trigger information to the cell or another cell based on whether or not the cell can transmit uplink data,
Wherein the terminal configures dual connectivity with two or more base stations. The method according to claim 1,
Wherein the step of verifying whether or not uplink data transmission of the cell is possible comprises:
Whether a scheduling request of the cell or a radio resource for a random access channel is allocated,
Wherein the step of transmitting the trigger information comprises:
And if the radio resource is not allocated, transmitting the trigger information to a primary cell of a primary cell or a primary cell of a master cell group of the secondary cell group. The method according to claim 1,
Wherein the step of verifying whether or not uplink data transmission of the cell is possible comprises:
And checking whether the uplink data transmission of the cell is possible by confirming on / off state information of the cell. The method of claim 3,
Wherein the step of transmitting the trigger information comprises:
Wherein when the cell is a primary secondary cell having a PUCCH transmission function and the on-off state information is in an off state, the trigger information is transmitted to a primary cell of the master cell group. 5. The method of claim 4,
The trigger information includes:
The indication indicating that a scheduling request or a random access request has been triggered in the secondary cell group. 5. The method of claim 4,
The trigger information includes:
Wherein the uplink data transmission includes at least one of cell identification information, cell index information, secondary cell group identification information, and cause information of the uplink data transmission triggered for the triggered cell. 5. The method of claim 4,
The trigger information includes:
The primary cell is transmitted through a PUCCH resource allocated for receiving a scheduling request of the secondary cell group in the primary cell,
Wherein the secondary random access preamble is transmitted through a dedicated random access preamble set for a random access request of the secondary cell group. The method of claim 3,
Wherein the step of transmitting the trigger information comprises:
Off state information is in an off state, the change of the on-off state information is confirmed according to a preset cycle,
And transmitting the trigger information to the cell when the on-off state information is changed to the on state. In a method for a base station to receive data,
Configuring dual connectivity to the secondary base station and the terminal;
Receiving trigger information of uplink data for the secondary base station from the terminal; And
And transmitting processing information for processing the trigger information to the terminal or the secondary base station. 10. The method of claim 9,
The trigger information includes:
And when the primary secondary cell of the secondary base station is in the off state. 10. The method of claim 9,
The trigger information includes:
Received via a PUCCH resource allocated to receive a scheduling request of the secondary base station,
Wherein the secondary random access preamble is set for a random access request of the secondary base station. 10. The method of claim 9,
Wherein the transmitting the processing information comprises:
And transmitting uplink signaling including bearer change information for changing a radio bearer to which the uplink data is transmitted to the base station. 10. The method of claim 9,
Wherein the transmitting the processing information comprises:
And transmitting state change information for changing the primary secondary cell to the on state to the secondary base station. In a terminal for transmitting data,
A controller for checking whether uplink data transmission of the cell is possible when uplink data transmission to a cell included in the secondary cell group is triggered; And
And a transmitter for transmitting the trigger information to the cell or another cell based on whether or not the cell can transmit uplink data,
Wherein the terminal comprises dual connectivity with two or more base stations. 15. The method of claim 14,
Wherein,
Whether a scheduling request of the cell or a radio resource for a random access channel is allocated,
The transmitter may further comprise:
And transmits the trigger information to the primary cell of the primary cell or the primary cell of the master cell group when the radio resource is not allocated. 15. The method of claim 14,
Wherein,
And confirms whether or not uplink data transmission of the cell is possible by checking on / off state information of the cell. 17. The method of claim 16,
The transmitter may further comprise:
And transmitting the trigger information to a primary cell of a master cell group when the cell is a primary secondary cell having a PUCCH transmission function and the on-off state information is in an off state. 18. The method of claim 17,
The trigger information includes:
And information indicating that a scheduling request or a random access request has been triggered in the secondary cell group. 18. The method of claim 17,
The trigger information includes:
The primary cell is transmitted through a PUCCH resource allocated for receiving a scheduling request of the secondary cell group in the primary cell,
Wherein the secondary random access preamble is transmitted through a dedicated random access preamble set for the random access request of the secondary cell group. 17. The method of claim 16,
Wherein,
Off state information is in an off state, the change of the on-off state information is confirmed according to a preset cycle,
The transmitter may further comprise:
And transmits the trigger information to the cell when the ON / OFF state information is changed to the ON state. A base station for receiving data,
A controller configured to configure dual connectivity for the secondary base station and the terminal;
A receiving unit for receiving trigger information of uplink data from the terminal to the secondary base station; And
And a transmitting unit for transmitting processing information for processing the trigger information to the terminal or the secondary base station. 22. The method of claim 21,
The trigger information includes:
And the primary secondary cell of the secondary base station is in the off state.

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