WO2015046780A1 - Method for transmitting uplink data and apparatus for same - Google Patents

Abstract

The present invention relates to a method and an apparatus for transmitting uplink data from a terminal to base stations, wherein a terminal establishing dual connectivity with a plurality of base station transreceives, while distinguishing paths, when transreceiving uplink and downlink traffic through a plurality of carriers. More specifically, the present invention provides a method and an apparatus, the method for transmitting uplink data from the terminal comprising the steps of: receiving upper layer signaling which includes information for establishing dual connectivity with a first base station and a second base station; establishing dual connectivity between the first base station and the second base station, based on the upper layer signaling; and submitting a PDCP PDU for each of one or more wireless bearers, from a PDCP object to an RLC entity, which is a peer to the second station, based on the upper layer signaling.

Description

Uplink data transmission method and apparatus therefor

The present invention relates to a method and apparatus for transmitting uplink data to a base station by a terminal, wherein the terminal configuring dual connectivity with a plurality of base stations is connected to the user data traffic of uplink and downlink through a plurality of carriers. The present invention relates to a method and apparatus for transmitting and receiving an uplink path differently from a downlink path.

In addition, the present invention is the amount of data available for transmission from the uplink buffers of the terminal to the base station in the terminal in the small cell environment to transmit the uplink user data by configuring dual connectivity with one or more base stations (dual connectivity) A method and apparatus for transmitting a buffer status report used for providing information regarding data available for transmission.

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

Currently, mobile communication systems such as Long Term Evolution (LTE) and LTE-Advanced of the 3GPP series require high-speed large-capacity communication systems capable of transmitting and receiving various data such as video and wireless data, beyond voice-oriented services.

There is a demand for a technology capable of increasing the capacity of a terminal by using a small cell for such a high-speed large-capacity communication system. That is, a technique for increasing traffic throughput by transmitting and receiving data using a macro cell having a wide coverage and a small cell having a relatively narrow coverage is required.

In addition, when the terminal transmits data to the base station, the speed and power consumption are also important. Therefore, while using a plurality of cells for a high-speed large-capacity communication system, the transmission speed for uplink data transmitted by the terminal while reducing power consumption for uplink data transmission needs to be increased. To this end, a specific procedure related to a method of transmitting and receiving uplink and downlink data in a small cell environment is required.

In particular, when the terminal transmits a large amount of data at high speed using a plurality of base stations, the terminal needs to transmit the correct amount of data to be transmitted on the uplink to the base station. There is also a need for a specific method of transmitting uplink data to be transmitted by a terminal.

In the case where the terminal configures a dual connection using a small cell according to the above-described request, it is necessary to set uplink transmission paths separately from downlinks in order to reduce power consumption for uplink data transmission.

In addition, in a dual connectivity configuration, the terminal transmits uplink data through the macro cell base station and the small cell base station, so that the path loss of the uplink data transmitted to the macro cell base station is relatively increased or transmitted to the small cell base station as the terminal moves. There is a problem in that uplink data is lost.

In addition, the present invention needs to transmit the buffer status information transmitted to the one or more base stations so that the buffer status information transmitted to the one or more base stations does not overlap or be omitted when the terminal configuring the radio bearer with one or more base stations.

In accordance with the present invention, a method for transmitting uplink data in a terminal, the method comprising: receiving higher layer signaling including information for configuring a dual connection with a first base station and a second base station and a higher layer; Establishing a dual connection with the first base station and the second base station based on signaling and a PDCP entity is peered to a first base station or a second base station based on higher layer signaling PDCP PDUs for each of one or more radio bearers; A method is provided that includes submitting to a configured RLC entity.

In addition, the at least one radio bearer provides a method characterized in that the radio bearer is configured to be split (split) to the first base station and the second base station.

In addition, the higher layer signaling, characterized in that it further comprises an index or identification information for identifying an uplink cell or uplink base station for transmitting the uplink data to the first base station or the second base station. To provide.

In addition, the index or classification information for transmitting the uplink data to the first base station or the second base station, a value for configuring to transmit the uplink data through the first base station and uplink data through the second base station It provides a method comprising a value for configuring to transmit.

Further, after the step of submitting to the RLC entity, the method further includes performing a logical channel priority procedure at the MAC entity peered to the first base station or the second base station.

In addition, the logical channel priority procedure provides a method for performing a logical channel priority procedure for the logical channels to carry the uplink data through the first base station or the second base station.

The present invention provides a method for controlling uplink data transmission by a first base station, the method comprising: generating higher layer signaling including information for configuring a dual connection with a terminal and transmitting higher layer signaling to the terminal. And configuring a split radio bearer for the terminal.

In addition, the higher layer signaling, characterized in that it further comprises an index or identification information for identifying an uplink cell or uplink base station for transmitting the uplink data to the first base station or the second base station. to provide.

In addition, the index or classification information for transmitting the uplink data to the second base station, a value for configuring to transmit the uplink data through the first base station and to configure the uplink data through the second base station It provides a method comprising a value for.

The present invention provides a terminal for transmitting uplink data, comprising: a receiver for receiving higher layer signaling including information for configuring a dual connection with a first base station and a second base station, and a first base station and a first base station based on higher layer signaling. A control unit configured to configure dual connectivity with 2 base stations, and control a PDCP entity to submit a PDCP PDU for each of one or more radio bearers to an RLC entity configured to be peered to the first base station or the second base station based on the higher layer signaling It provides a terminal device including a.

In addition, the at least one radio bearer provides a terminal device characterized in that the radio bearer is configured to be split (split) to the first base station and the second base station.

The higher layer signaling further includes an index or identification information for identifying an uplink cell or an uplink base station for transmitting the uplink data to the first base station or the second base station. Provide the device.

In addition, the index or classification information for transmitting the uplink data to the first base station or the second base station, a value for configuring to transmit the uplink data through the first base station and uplink data through the second base station It provides a terminal device comprising a value for configuring to transmit.

In addition, the controller provides a terminal device, characterized in that the control to perform a logical channel priority procedure in the MAC entity peered to the first base station or the second base station.

In addition, the logical channel priority procedure provides a terminal device, characterized in that performing a logical channel priority procedure for the logical channels for transmitting the uplink data through the first base station or the second base station.

The present invention provides a first base station for controlling uplink data transmission of a terminal, comprising: a control unit for generating higher layer signaling including information for configuring a dual connection with the terminal, and a transmitting unit for transmitting higher layer signaling to the terminal. However, the control unit provides a base station apparatus for controlling to configure a split radio bearer for the terminal.

In addition, the higher layer signaling, the base station further comprises an index or identification information for identifying an uplink cell or uplink base station for transmitting the uplink data to the first base station or the second base station. Provide the device.

In addition, the index or classification information for transmitting the uplink data to the first base station or the second base station, a value for configuring to transmit the uplink data through the first base station and uplink data through the second base station It provides a base station apparatus comprising a value for configuring to transmit.

According to the present invention, a method for transmitting buffer status information by a terminal includes: configuring and separating one or more logical channels or logical channel groups mapped to a split bearer according to higher layer signaling so as to be dually connected with a first base station and a second base station; A method comprising transmitting to a first base station or a second base station the amount of data available for transmission in a PDCP layer of at least one logical channel or logical channel group mapped to a bearer.

In addition, the PDCP layer available data amount includes information on the available data amount of PDCP to be transmitted by the terminal uplink, and is distinguished from a buffer status report, at least one of the first base station and the second base station It provides a way to be transmitted.

In addition, the PDCP buffer status information is provided in the MAC control element is transmitted.

Further, the PDCP layer available data amount is distributed and included in each of the buffer status report sent to the first base station and the buffer status report sent to the second base station.

In addition, the PDCP layer available data amount provides a method to be distributed based on configuration information received from the first base station or the second base station. The configuring of the logical channel or the logical channel group mapped to the split bearer according to the higher layer signaling may include configuring a buffer status report (BSR) timer for each base station or cell group. Provide a way to.

In addition, the PDCP layer available data amount is included in only one of the buffer status report transmitted to the first base station or the buffer status report transmitted to the second base station according to the higher layer signaling is transmitted. To provide.

The present invention provides a method for receiving buffer status information by a first base station, comprising: configuring a dual connection between a second base station and a terminal for at least one logical channel or logical channel group mapped to a split bearer through higher layer signaling; It provides a method comprising the step of receiving the PDCP layer available data amount from the terminal.

In addition, the amount of PDCP layer available data is provided separately from the buffer status report.

The PDCP layer available data amount is also included in the MAC control element to provide a method for receiving.

In addition, the PDCP layer available data amount is information distributed by the terminal and provides a method of being included in a buffer status report. In addition, the PDCP layer available data amount is included in only the buffer status report received by the first base station according to the higher layer signaling, or included in only the buffer status report received by the second base station and received by the first base station. It provides a way to be received without being included in the report.

According to the present invention, a terminal for transmitting buffer status information includes a control unit and a split bearer configured to dually connect one or more logical channels or logical channel groups mapped to the split bearer according to higher layer signaling with the first base station and the second base station. Provided is a terminal apparatus including a transmitter for transmitting PDCP layer available data amounts of one or more logical channels or logical channel groups to be mapped to a first base station or a second base station.

In addition, the PDCP layer available data amount includes information on the available data amount of PDCP to be transmitted by the terminal uplink, and is distinguished from a buffer status report, at least one of the first base station and the second base station It provides a terminal device characterized in that the transmission.

In addition, the PDCP layer available data amount provides a terminal device, characterized in that transmitted in the MAC control element.

The PDCP layer available data amount is distributed and included in each of the buffer status report transmitted to the first base station and the buffer status report transmitted to the second base station.

The PDCP layer usable data amount is distributed based on configuration information received from the first base station or the second base station. In addition, the controller provides a terminal device comprising the logical channel or logical channel group including a buffer status report (BSR) timer for each base station or cell group according to higher layer signaling. .

In addition, the PDCP layer available data amount is included in only one of the buffer status report transmitted to the first base station or the buffer status report transmitted to the second base station according to the higher layer signaling is transmitted. A terminal device is provided.

The present invention provides a first base station for receiving buffer status information, comprising: a control unit and a terminal configuring a dual connection between a second base station and a terminal for one or more logical channels or logical channel groups mapped to a split bearer through higher layer signaling; Provided is a base station apparatus including a receiving unit for receiving a PDCP layer available data amount.

In addition, the PDCP layer available data amount provides a base station apparatus, characterized in that received separately from the buffer status report.

In addition, the PDCP layer available data amount is provided in the base station apparatus, characterized in that received in the MAC control element.

The PDCP layer available data amount is information distributed by the terminal and is included in a buffer status report to provide the base station apparatus. In addition, the PDCP layer available data amount is included in the buffer status report received from the terminal to the first base station according to the higher layer signaling, or included in only the buffer status report received to the second base station and received at the first base station. A base station apparatus is provided which is received without being included in a buffer status report.

According to the present invention described above, there is an effect that the terminal can transmit the uplink data traffic through a specific base station with a small path loss with the terminal in an environment in which a dual connection with a plurality of base stations. This reduces the power consumption of the terminal and has the effect of improving the uplink data transmission speed. Alternatively, the terminal may transmit uplink data traffic through a specific base station having large coverage in an environment in which the terminal configures a dual connection with a plurality of base stations. Through this, there is an effect that can reduce the data loss due to the movement of the terminal.

In addition, according to the present invention, an uplink buffer status report and a logical channel priority procedure may be independently performed for a specific cell or a specific base station even under a dual connectivity structure.

In addition, according to the present invention, when the terminal transmits the buffer status information for uplink transmission, there is an effect that the transmitted buffer status information is transmitted so as not to be duplicated or missing to one or more base stations.

In addition, according to the present invention, in transmitting buffer status information of a logical channel or a logical channel group mapped to a split bearer configured as a dual connection, the radio resource by accurately transmitting the available data amount information of the PDCP object buffer to one or more base stations It has the effect of providing efficient use of.

1 illustrates an uplink layer 2 structure in a carrier aggregation configuration.

2 illustrates a downlink layer 2 structure in a carrier aggregation configuration.

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

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

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

6 is a diagram illustrating an example of a layer 2 protocol structure for user plane data transmission.

7 illustrates another example of a layer 2 protocol structure for user plane data transmission.

8 is a diagram illustrating an example of radio resource configuration information according to the present invention.

9 is a diagram showing another example of radio resource configuration information according to the present invention.

10 is a diagram showing another example of radio resource configuration information according to the present invention.

11 is a diagram showing another example of radio resource configuration information according to the present invention.

12 is a diagram showing another example of radio resource configuration information according to the present invention.

13 is a view showing another example of radio resource configuration information according to the present invention.

14 is a diagram illustrating an example of SeNBSCellToAddMod according to the present invention.

15 illustrates a layer 2 structure of a master base station and a secondary base station according to an embodiment of the present invention.

16 is a diagram illustrating a layer 2 structure of a master base station and a secondary base station according to another embodiment of the present invention.

17 is a diagram illustrating a layer 2 structure of a terminal according to another embodiment of the present invention.

18 illustrates an example of RLC-Config for AM RLC according to the present invention.

19 shows another example of RLC-Config for AM RLC according to the present invention.

20 shows another example of RLC-Config for AM RLC according to the present invention.

21 is a signal diagram illustrating operations of a terminal and a base station according to another embodiment of the present invention.

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

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

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

25 is a diagram showing the configuration of a base station according to another embodiment of the present invention.

26 is a diagram illustrating an example of a MAC configuration diagram of a conventional terminal.

FIG. 27 is a diagram illustrating an example of a bearer split user plane structure. FIG.

28 illustrates another example of a bearer split user plane structure.

FIG. 29 is an exemplary diagram of an available data amount of a logical channel mapped to a split bearer in a terminal for explaining the present invention.

30 is a diagram illustrating an example of a configuration of a MAC PDU according to an embodiment of the present invention.

31 is a diagram illustrating an example of an LCID value for UL-SCH according to another embodiment of the present invention.

32 is a diagram illustrating an example of each PDCP BSR MAC control element format.

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

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

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

36 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 through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

The wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data, and the like. The wireless communication system includes a user equipment (UE) and a base station (base station, BS, or eNB). In the present specification, a user terminal is a generic concept meaning a terminal in wireless communication. In addition, user equipment (UE) in WCDMA, LTE, and HSPA, as well as mobile station (MS) in GSM, user terminal (UT), and SS It should be interpreted as a concept that includes a 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, an Sector, a Site, and a BTS. Other terms such as a base transceiver system, an access point, a relay node, a remote radio head (RRH), a radio unit (RU), and a small cell may be called.

In other words, in the present specification, a base station or a cell is a generic meaning indicating some areas or functions covered by a base station controller (BSC) in CDMA, a Node-B in WCDMA, an eNB or a sector (site) in LTE, and the like. It should be interpreted as, and it is meant to cover all the various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node, RRH, RU, small cell communication range.

Since the various cells listed above have a base station for controlling each cell, the base station may be interpreted in two senses. i) A device providing a mega cell, a macro cell, a micro cell, a pico cell, a femto cell, a small cell in relation to a radio area, or ii) may indicate the radio area itself. In i) all devices which provide a given wireless area are controlled by the same entity or interact with each other to cooperatively configure the wireless area to direct the base station. The eNB, RRH, antenna, RU, LPN, point, transmit / receive point, transmit point, receive point, and the like, according to the configuration of the radio region, become an embodiment of the base station. In ii), the base station may indicate the radio area itself to receive or transmit a signal from a viewpoint of a user terminal or a neighboring base station.

Therefore, megacells, macrocells, microcells, picocells, femtocells, small cells, RRHs, antennas, RUs, low power nodes (LPNs), points, eNBs, transmit / receive points, transmit points, and receive points are collectively referred to as base stations. do.

In the present specification, the user terminal and the base station are two transmitting and receiving entities used to implement the technology or technical idea described in this specification in a comprehensive sense and are not limited by the terms or words specifically referred to. The user terminal and the base station are two types of uplink or downlink transmitting / receiving subjects used to implement the technology or the technical idea described in the present invention, and are used in a generic sense and are not limited by the terms or words specifically referred to. Here, the uplink (Uplink, UL, or uplink) refers to a method for transmitting and receiving data to the base station by the user terminal, the downlink (Downlink, DL, or downlink) means to transmit and receive data to the user terminal by the base station It means the way.

There is no limitation on the multiple access scheme applied to the wireless communication system. Various multiple access techniques 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, OFDM-TDMA, OFDM-CDMA Can be used. One embodiment of the present invention can be applied to resource allocation in the fields of asynchronous wireless communication evolving to LTE and LTE-Advanced through GSM, WCDMA, HSPA, and synchronous wireless communication evolving to CDMA, CDMA-2000 and UMB. The present invention should not be construed as being limited or limited to a specific wireless communication field, but should be construed as including all technical fields to which the spirit of the present invention can be applied.

The uplink transmission and the downlink transmission may use a time division duplex (TDD) scheme that is transmitted using different times, or may use a frequency division duplex (FDD) scheme that is transmitted using different frequencies.

In addition, in systems such as LTE and LTE-Advanced, a standard is configured by configuring uplink and downlink based on one carrier or a pair of carriers. The uplink and the downlink include a Physical Downlink Control CHannel (PDCCH), a Physical Control Format Indicator CHannel (PCFICH), a Physical Hybrid ARQ Indicator CHannel (PHICH), a Physical Uplink Control CHannel (PUCCH), an Enhanced Physical Downlink Control CHannel (EPDCCH), and the like. Control information is transmitted through the same control channel, and data is configured by a data channel such as a physical downlink shared channel (PDSCH) and a physical uplink shared channel (PUSCH).

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

In the present specification, a cell means a component carrier having a coverage of a signal transmitted from a transmission / reception point or a signal transmitted from a transmission point or a transmission / reception point, and the transmission / reception point itself. Can be.

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

The multiple transmit / receive point is at least one having a base station or a macro cell (hereinafter referred to as an eNB) and a high transmission power or a low transmission power in a macro cell region, which is wired controlled by an optical cable or an optical fiber to the eNB. May be RRH.

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

Hereinafter, a situation in which a signal is transmitted and received through a channel such as a PUCCH, a PUSCH, a PDCCH, an EPDCCH, and a PDSCH may be expressed in the form of 'sending and receiving a PUCCH, a PUSCH, a PDCCH, an EPDCCH, and a PDSCH.'

In addition, hereinafter, a description of transmitting or receiving a PDCCH or transmitting or receiving a signal through the PDCCH may be used as a meaning including transmitting or receiving an EPDCCH or transmitting or receiving a signal through the EPDCCH.

That is, the physical downlink control channel described below may mean PDCCH or EPDCCH, and may also be used to include both PDCCH and EPDCCH.

In addition, for convenience of description, the EPDCCH, which is an embodiment of the present invention, may be applied to the portion described as the PDCCH, and the EPDCCH may be applied to the portion described as the EPDCCH as an embodiment of the present invention.

Meanwhile, high layer signaling described below includes RRC signaling for transmitting RRC information including an RRC parameter.

The eNB performs downlink transmission to the terminals. The eNB includes downlink control information and an uplink data channel (eg, a physical downlink shared channel (PDSCH), which is a primary physical channel for unicast transmission, and scheduling required to receive the PDSCH. For example, a physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission on a physical uplink shared channel (PUSCH) may be transmitted. Hereinafter, the transmission and reception of signals through each channel will be described in the form of transmission and reception of the corresponding channel.

Small cells using low power nodes are being considered as a means to cope with the explosion of mobile traffic. Low power nodes represent nodes that use lower transmit (Tx) power than typical macro nodes.

In carrier aggregation (CA) technology before 3GPP Release 11, a small cell can be constructed using a low power remote radio head (RRH), which is a geographically dispersed antenna within macro cell coverage.

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

An ideal backhaul means a backhaul that exhibits very high throughput and very low latency, such as optical fiber, dedicated point-to-point connections using LOS microwaves (Line Of Sight microwave).

In contrast, backhaul that exhibits relatively low throughput and large delay, such as digital subscriber line (xDSL) and Non LOS microwaves, is called non-ideal backhaul.

The plurality of serving cells may be merged through a single base station-based carrier aggregation (CA) technology described above to provide a service to a terminal. That is, a plurality of serving cells may be configured for a UE in a radio resource control (hereinafter referred to as 'RRC') CONNECTED state, and when an ideal backhaul is established between the macro cell node and the RRH, the macro cell And the RRH cell may be configured with serving cells to provide a service to the terminal.

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

In an RRC connection establishment / reestablishment / handover, one serving cell is a Non-Access Stratum (hereinafter referred to as 'NAS') mobility information (e.g. TAI: Tracking Area Identity) and one serving cell provides security input in RRC connection reset / handover. Such a cell is called a primary cell (PCell). The PCell can only be changed with the handover procedure. According to terminal capabilities, SCells (Secondary Cells) may be configured as a serving cell together with a PCell.

The configuration of the above-described SCell may vary depending on the traffic amount, so that the SCell may be configured only with a downlink component carrier (CC). The use of uplink resources for each SCell can be configured in addition to the downlink resources. That is, the SCell may not be configured to use only uplink resources. On the other hand, the PCell must always be configured with a downlink CC and an uplink CC.

In addition, one base station that processes PCell and SCells has different carriers (DL / UL PCC: Downlink / Uplink Primary Component Carrier, DL / UL SCC: Downlink / Uplink Secondary Component Carrier) in the physical layer, but MAC (Medium Access) Only control layer can be affected. Further layers (RLC / PDCP) do not affect the RLC / PDCP layer before carrier aggregation is introduced. That is, the CA operation cannot be distinguished in the RLC / PDCP layer.

1 illustrates an uplink layer 2 structure in a carrier aggregation configuration.

2 illustrates a downlink layer 2 structure in a carrier aggregation configuration.

1 and 2, the multi-carrier attributes of the physical layer according to the CA based on the single eNB affect only the MAC layer (Medium Access Control). The MAC layer has one independent Hybrid Automatic Retransmit reQuest (HARQ) entity per serving cell in the uplink and downlink. Each HARQ entity processes a data stream of a component carrier (CC).

That is, as shown in FIGS. 1 and 2, the MAC layer according to the SCell addition and removal in a single base station-based CA forms an independent HARQ entity in each of the serving cells in the uplink and the downlink to form a data stream of the CC. Treated.

As described above, in the conventional mobile communication network, the macro cell and the small cell had to be scheduled under one eNB control in order to use the small cell using a carrier aggregation technology. To this end, there is a problem that requires an ideal backhaul construction between the macro cell node and the small cell node. Therefore, when a macro cell and a small cell are constructed through separate eNBs through non-ideal backhaul, there is a problem in that carrier aggregation technology cannot be used. In addition, due to power imbalance of macro cells with high output power and low output power small cells, uplink / downlink can provide optimal performance in the downlink and uplink. Due to the different cell borders, the performance of uplink / downlink cell borders may be degraded. In addition, the PCell is always configured to handle uplink and downlink traffic, and could not configure a SCell for uplink traffic only. That is, in case of using carrier aggregation technology, even if a small cell having a small path loss with a terminal is configured as an SCell, uplink traffic could be delivered through a macro cell configured as a PCell. Due to such a problem, there is a problem that the terminal consumes more power by using a macrocell with a large path loss for transmitting uplink traffic.

The present invention devised to solve such a problem is that between the macro cell and the small cell or under the control of the macro cell in an environment in which the macro cell and the small cell are established through separate eNBs through a non-ideal backhaul in a mobile communication network. It is an object of the present invention to provide a method of separating and transmitting an uplink traffic path and a downlink traffic path in transmitting user plane data traffic through cooperation. That is, the present invention provides a method of providing different uplink traffic paths and downlink traffic paths of a specific data radio bearer.

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

Referring to FIG. 3, the macro cell 302 and the small cells 301 may have the same carrier frequency F1. The first base station 310 providing the macro cell and the second base station 332, 334, 336 providing each small cell are connected through a non-ideal backhaul. Small cells are built in an overlapped macro cell 302 network. An outdoor small cell environment and a small cell cluster 301 may be considered. The UE may be provided with a plurality of serving cells through a dual connection with the macro cell and the small cell in the small cell cluster 301.

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

Referring to FIG. 4, the macro cell 402 and the small cells 401 may have different carrier frequencies F1 and F2. The first base station 410 providing the macro cell and the second base station 432, 434, 436 providing each small cell are connected via non-ideal backhaul. Small cells are built in an overlapped macro cell 402 network. An outdoor small cell environment and a small cell cluster 401 may be considered. The UE may be provided with a plurality of serving cells through a dual connection with the macro cell and the small cell in the small cell cluster 401. In this case, the frequency of each serving cell may be different from F1 and F2 as shown in FIG. 4.

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

Referring to FIG. 5, a case in which a plurality of small cells forms a small cell cluster 501 may be considered. In this case, the small cell base stations 510, 512, and 514 providing the small cells are connected through non-ideal backhaul. Indoor small cell environment and small cell cluster 501 are considered. In addition, the same carrier frequency may be used between the small cells, or different carrier frequencies may be used. Coverage may overlap between small cells.

In the scenarios of FIGS. 3 and 4, the small cell eNB or the specific small cell eNB in the scenario of FIG. 5 may operate as a stand-alone eNB. That is, the UE may establish one RRC connection with the small cell eNB and control one or more Signaling Radio Bearers (SRBs) for control plane data transmission. For user plane data transmission, the UE may have a small cell eNB and one or more Data Radio Bearers (DRBs).

In the scenarios of FIGS. 3 and 4, the UE may transmit user plane data through one or more small cell eNBs or through cooperation between the macro cell eNB and one or more small cell eNBs under the control of the macro cell eNB. Can be. That is, the UE establishes one RRC connection with the macro cell eNB and sets one or more Signaling Radio Bearers (SRBs) for control plane data transmission. For user plane data transmission, the UE may establish one or more Data Radio Bearers (DRBs) with the macrocell eNB and / or the small cell eNB. Similarly, in the scenario of FIG. 5, the UE may be controlled through one or more other small cell eNBs under the control of one small cell eNB, or through cooperation between one small cell eNB and one or more other small cell eNBs. User plane data can be sent. That is, the UE establishes one RRC connection with one small cell eNB and sets one or more Signaling Radio Bearers (SRBs) for control plane data transmission. The UE may establish one or more Data Radio Bearers (DRBs) with one small cell eNB and / or another small cell eNB for user plane data transmission.

The invention can be performed in all of the scenarios of FIGS. 3-5 described above. However, hereinafter, only the case of FIGS. 3 and 4 will be described as an example for convenience of explanation and understanding, and may be applied to the case of FIG. 5.

On the other hand, in the present specification, when the terminal configures dual connectivity, forms an RRC connection with the terminal, terminates the base station or S1-MME providing a PCell as a reference for handover, and mobility anchor (mobility anchor) to the core network The base station which acts as a master base station or a 1st base station is described. The master base station or the first base station may be a base station providing the above-described macro cell, and may be a base station providing any one small cell in a dual connectivity situation between the small cells. In addition, a base station that is distinguished from a master base station in a dual connectivity environment and provides additional radio resources to a terminal is described as a secondary base station or a second base station. The first base station (master base station) and the second base station (secondary base station) may provide at least one cell to the terminal, respectively, and the first base station and the second base station may be connected through an interface between the first base station and the second base station. have. For better understanding, 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, a cell associated with the first base station may also be described as a small cell.

The macro cell in the present invention may mean each of at least one or more cells, and may be described as a generic term for all cells associated with the first base station. In addition, the small cell may also mean each of at least one or more cells, and may also be described as a generic term for all cells associated with the second base station. However, as described above, in a specific scenario such as a small cell cluster, the cell may be a cell associated with the first base station. In this case, the cell of the second base station may be described as another small cell or another small cell. In addition, the terminal may perform communication through the plurality of cells associated with the first base station and the plurality of cells associated with the second base station, and in this case, the PCell function of the plurality of cells associated with the first base station is performed. The specific cell may be described as the first base station PCell. In addition, a specific cell among a plurality of cells associated with the second base station may be described as the second base station PCell. The second base station PCell refers to a cell that performs all or part of the functions of the aforementioned PCell among the cells associated with the second base station. For example, the second base station PCell may perform a PUCCH transmission / reception function. When the dual connectivity is configured in the terminal, the cell associated with the first base station or the serving cell associated with the first base station is referred to as a master cell group, and the cell associated with the second base station or the serving cell associated with the second base station is referred to as a secondary cell group. can do. The cell group is used as a concept for distinguishing a base station from the terminal point of view.

6 is a diagram illustrating an example of a layer 2 protocol structure for user plane data transmission.

Referring to FIG. 6, user plane data may be transmitted using radio resources provided through a first base station and a second base station for each data radio bearer using the protocol structure as shown in FIG. 6. For example, the PDCP entity of the first base station may submit a PDCP PDU to the first base station RLC entity and the second base station RLC entity. That is, the specific radio bearer may be configured by splitting the first base station and the second base station.

7 illustrates another example of a layer 2 protocol structure for user plane data transmission.

As another example of this, the user plane data may be transmitted only through the first base station or the user plane data only through the second base station for each data radio bearer using the protocol structure as shown in FIG. 7.

In the scenario or protocol structure of FIGS. 3 to 7, the UE of the present invention uploads user plane data through one or more secondary base stations under the control of the master base station, or through cooperation between the master base station and one or more secondary base stations. It is possible to separate link traffic and downlink traffic. That is, an eNB that can provide an optimized transmission rate may be selected in consideration of load, path loss, and coverage for a given uplink and downlink data traffic. For example, the uplink traffic and the downlink traffic are separated and delivered. The uplink traffic for all DRBs is transmitted through the terminal and the secondary base station with low path loss, and the downlink traffic for all DRBs (or RBs) is transferred to the master base station. Can pass through.

As another example, uplink traffic for a particular DRB (s) is passed through the secondary base station, downlink traffic for another particular DRB (s) is passed through the master base station, and another specific DRB (s) For traffic, both uplink downlinks can pass through the master base station and the secondary base station. That is, for a specific data radio bearer transmitting user plane data using radio resources provided through the first base station and the second base station as shown in FIG. 6, uplink traffic is transmitted only through the second base station, and downlink traffic is transmitted. It can be delivered through the first base station and the second base station. Alternatively, for another specific data radio bearer transmitting user plane data using radio resources provided through the first base station and the second base station as shown in FIG. 6, uplink traffic is transmitted through the first base station and the second base station. Downlink traffic may be forwarded only through the first base station. Alternatively, for another specific data radio bearer transmitting user plane data by using radio resources provided through the first base station and the second base station as shown in FIG. 6, both the uplink traffic and the downlink traffic may be the first base station and the second base station. It may be delivered through a base station.

As another example, uplink / downlink user plane data traffic may be transmitted only through a first base station for a specific data radio bearer as shown in FIG. 7. Alternatively, uplink / downlink user plane data traffic may be transmitted only through the second base station for another specific data radio bearer. The method for the UE to separately transmit and receive transmission paths of the uplink traffic and the downlink traffic may be transmitted and received by dividing the paths by various implementation methods as well as the above-described examples.

Hereinafter, a method of separately transmitting and receiving uplink traffic and downlink traffic according to each embodiment of the present invention will be described.

First embodiment: Method for separating up and down traffic transmission path in units of a radio bearer (RB).

When the UE establishes an RRC connection with a first base station providing a cell that operates as a PCell and is in an RRC Connected state, the UE sets a cell associated with a second base station connected through a non-ideal backhaul to a second base station SCell (or serving cell). Can be added as

The second base station to add cells associated with the second base station to the second base station SCell after the first base station providing a cell operating as a PCell detects a new second base station SCell candidate or to modify the configured second base station SCell Upon determining the SCell addition / modification, the first base station providing the cell operating as the PCell adds / modifies the second base station SCell through the RRC Connection Reconfiguration procedure.

If the second base station SCell list (SeNBSCellToAddModList) to be added / modified is included in the RRC Connection Reconfiguration message received by the UE, the UE performs addition or modification of the second base station SCell. The second base station SCell information (SeNBSCellToAddMod) to be added / modified of the second base station SCell list to be added / modified may include the following information.

■ (Second Base Station) SCell Index ((SeNB) SCellIndex): Contains index information used to identify one second base station SCell within second base station SCells configured for the UE.

■ Cell Identification (CellIdentification): Includes Physical Cell ID (PCI) and Absolute Radio Frequency Channel Number (ARFCN) information of the second base station SCell.

■ Radio Resource Configuration Common SCell Information (radioResourceConfigCommonScell): Essential information for UE to operate in SCell, which includes common radio resource configuration information in system information. As an example of the common radio resource configuration information, physical layer parameters, random access parameters, and the like may be included.

■ RadioResourceConfigDedicatedSCell: Contains UE-specific configuration information (e.g. physicalConfigDedicatedSCell, mac-MainConfigSCell) applicable to the SCell.

The cell information (cell addition modification information) to be added so that the terminal can distinguish the second base station SCell from the base station SCell linked to the existing PCell may include the second base station identification information. Alternatively, the second base station SCell index value may be set differently from the SCell index value of the base station linked to the existing PCell to distinguish the cell associated with the second base station. For example, in order to use a value other than the value used as the SCell index of the base station linked to the existing PCell, the SCell index, which can have an integer value from 1 to 7, currently has an integer value from 1 to 14 You can do that. That is, an integer value of 1 to 7 may be used as an index for SCells of a base station linked to a PCell, and an integer value of 8 to 14 may be used as an index for a second base station. As another example, in order to distinguish the SCell index of the base station linked to the PCell and the SCell index of the second base station, the SCell index and the indication information field indicating that the SCell through the second base station may be configured and transmitted together.

If the second base station SCell index included in the above-described second base station SCell information to be added / modified is not a current UE configuration part, the UE is included in the received radio resource configuration common SCell information and the radio resource configuration dedicated SCell information. Accordingly, the second base station SCell corresponding to the cell identifier is added. That is, when the second base station SCell is not configured for the UE, the second base station SCell corresponding to the cell identifier is added according to the received radio resource configuration common SCell information and the radio resource configuration dedicated SCell information.

If the second base station SCell index included in the second base station SCell information to be added / modified is a current UE configuration part, the UE modifies the second base station SCell according to the received radio resource configuration dedicated SCell information. . That is, in the case of the second base station SCell configured for the UE, the second base station SCell is modified according to the received radio resource configuration dedicated SCell information.

The information included in the above-described second base station SCell information to be added / modified is the first base station and the second base station before the first base station providing the cell operating as the PCell adds / modifies the second base station SCell through the RRC Connection Reconfiguration procedure. Interrogation can be made through the X2 interface. As another example, the information included in the second base station SCell information to be added / modified may be preconfigured in the first base station providing a cell operating as a PCell, stored in advance through operations, administration and maintenance (OAM), or previously generated. 2 may be stored and used in a base station SCell addition / modification procedure.

As described above, the UE may distinguish the CC associated with the second base station or the second base station in adding / modifying the second base station. Through this, the UE of the present invention can distinguish a transmission / reception path of downlink data (traffic) and uplink data (traffic). Specifically, a first base station providing a cell operating as a PCell may be configured as follows for a first base station providing a cell operating as a PCell and / or a second base station providing a cell operating as an SCell through an RRC Connection Reconfiguration procedure. The same method can be used to configure radio resources. Hereinafter, a specific embodiment of configuring a radio resource will be described with reference to the drawings.

A method of including cell / base station index / division information for data transmission path establishment in RadioResourceConfigDedicated.

A first base station providing a cell operating as a PCell uses a radio bearer addition modification list (DRB-ToAddModList) or radio bearer release list (DRB-ToReleaseList) information of radio resource configuration information (RadioResourceConfigDedicated). Radio resources may be configured for a second base station providing a cell operating as a serving first base station and / or a second base station SCell (or serving cell). For example, by adding / modifying a specific radio bearer of a first base station providing a cell operating as a PCell to a second base station providing a cell operating as a first base station and / or a second base station SCell (or serving cell). Can be configured.

For example, in the connection structure as shown in FIG. 6, the wireless bearer additional modification information DRB-ToAddMod of the wireless bearer addition modification list drb-ToAddModList is eps-BearerIdentity (EPS bearer identifier), drb-Identity, and PDCP configuration information. (pdcp-Config), one or more of RLC configuration information (rlc-Config), logicalChannelIdentity, and logicalChannelConfig for the RLC entity peered to the first base station RLC entity and the RLC entity peered to the second base station RLC entity. .

As another example, in the connection structure as shown in FIG. 7, the radio bearer modification information DRB-ToAddMod of the radio bearer addition modification list drb-ToAddModList may be eps-BearerIdentity (EPS bearer identifier), drb-Identity, second base station. One or more of PDCP entity configuration information (pdcp-Config) peered to the PDCP entity, RLC entity configuration information (rlc-Config) peered to the second base station RLC entity, logicalChannelIdentity, logicalChannelConfig.

A first base station providing a cell operating as a PCell may separate uplink traffic and downlink traffic for a specific radio bearer and transmit the uplink cell identifier (eg, uplink cell identifier) to the radio bearer modification information (DRB-ToAddMod). , PCI) / downlink cell identifier (e.g. PCI) or uplink SCell index / downlink SCell (or PCell) index or uplink eNB identifier / downlink eNB identifier or UE to uplink / downlink cell / base station The index / division information for distinguishing may be included. Alternatively, the first base station operating as a PCell may separate the uplink traffic and the downlink traffic for a specific radio bearer and deliver the same through the specific cell or the specific second base station SCell or the specific CC or the specific eNB. Uplink Cell Identifier (eg PCI) / Downlink Cell Identifier (eg PCI) or Uplink SCell Index / Downlink SCell (or PCell) Index or Uplink eNB / The downlink eNB identifier or the UE may include index / division information for distinguishing uplink / downlink cell / base station.

The UE may use the uplink cell identifier (eg PCI) / downlink cell identifier (eg PCI) or uplink SCell index / downlink SCell index or uplink eNB identifier / When the downlink eNB identifier or the UE receives the index / division information for distinguishing the uplink / downlink cell / base station, the uplink / downlink traffic of the radio bearer is respectively transmitted to the uplink cell / downlink cell or uplink SCell / A cell group associated with a downlink SCell or an uplink CC / downlink CC or an uplink eNB / downlink eNB or an uplink eNB may be classified and transmitted through a cell group associated with the downlink eNB.

If the UE further modifies the radio bearer, the aforementioned uplink cell identifier (eg PCI) / downlink cell identifier (eg PCI) or uplink SCell index / downlink SCell index or uplink eNB When the identifier / downlink eNB identifier or the UE receives radio resource configuration information that does not include index / division information for distinguishing the uplink / downlink cell / base station, the above-described radio bearer does not distinguish between the uplink and the downlink. It can be delivered without. That is, the radio bearer may be delivered through a macro cell, a primary component carrier (PCC), or a first base station. As another example, the radio bearer may be delivered through the serving cell or the serving cell eNB. For example, it may be delivered through a cell group associated with the first base station and the second base station or the first base station and a cell group associated with the second base station.

If the UE receives radio resource configuration information including only an uplink cell identifier (for example, PCI) or an uplink SCell index or an uplink eNB identifier in further modifying the radio bearer, the UE receives information on the corresponding radio bearer. Uplink traffic may be delivered through the cell or the base station or a cell group associated with the base station. The terminal may transmit downlink traffic for the corresponding radio bearer through a macro cell or a cell associated with the first base station or the first base station. As another example, the terminal may deliver uplink traffic for the radio bearer through the cell, the base station, or a cell group associated with the base station. The terminal may transmit downlink traffic through the serving cell or the serving cell eNB for the corresponding radio bearer. That is, the terminal may transmit downlink traffic for the corresponding radio bearer through the macro cell and the small cell, the first base station and the second base station, or the cell group associated with the first base station and the cell group associated with the second base station.

The information included in the radio bearer addition modification list (drb-ToAddModList) described above as an example is described before the first base station operating as a PCell adds / modifies and / or releases the radio bearer through the RRC Connection Reconfiguration procedure. It may be generated through a procedure through the X2 interface between the second base station.

8 is a diagram illustrating an example of radio resource configuration information according to the present invention.

Referring to FIG. 8, the above-described radio resource configuration information may include uplink cell identifiers (eg, PCI) / downlink cell identifiers (eg, PCI) or uplink SCell index / The downlink SCell index or uplink eNB identifier / downlink eNB identifier or the UE may include index / division information for distinguishing the uplink / downlink cell / base station. That is, the uplink cell identifier (eg PCI) / downlink cell identifier (eg PCI) or uplink SCell index / downlink SCell index or uplink eNB in the radio bearer add modification information (DRB-ToAddMod). Radio resource configuration information including an identifier / downlink eNB identifier or index / division information for identifying a cell / base station to which the UE will transmit uplink traffic and / or a cell / base station to transmit downlink traffic is an example. It can be configured together. Specifically, for example, the ENBIndex may be configured to have an integer value between 1 and 5 as a specific base station index value for transmitting uplink traffic. As another example, the ENBIndex may be configured to have a value of True if configured to transmit uplink traffic only through the second base station, or False otherwise (eg, configured to transmit uplink traffic only through the first base station). As another example, the ENBIndex is a value for distinguishing the configuration of transmitting uplink traffic only through the second base station, a value for distinguishing the configuration of transmitting uplink traffic only through the first base station, the first base station and the second. It may be configured to be able to distinguish a value for distinguishing what is configured to transmit uplink traffic through the base station. As another example, ENBIndex may have SCellIndex / ENBIndex as a value list. That is, ENBIndex may have two index values when downlink traffic is processed through two base stations.

As another example, a first base station operating as a PCell may use an uplink cell identifier (eg, an uplink cell identifier (DRB-ToAddMod)) in order to separate and transmit uplink traffic and downlink traffic for a specific radio bearer. , PCI) or uplink second base station SCell index or uplink eNB identifier or index / division information for identifying the cell / base station to which the UE will carry uplink traffic. Alternatively, the first base station may transmit uplink traffic for a specific radio bearer to the small cell configured with the second base station SCell in the uplink cell identifier (eg, PCI) in the radio bearer additional modification information (DRB-ToAddMod) or The uplink second base station SCell index or uplink eNB identifier or the UE may include index / division information for identifying the cell / base station to which the uplink traffic will be delivered. Alternatively, the first base station may transmit the uplink traffic for a specific radio bearer to the radio bearer additional modification information (DRB-ToAddMod) to deliver uplink traffic through a specific cell or a specific second base station SCell or a specific CC or a specific eNB. For example, PCI) or an uplink second base station SCell index or uplink eNB identifier or an index / division information for identifying a cell / base station to which the UE will carry uplink traffic.

In the UE further modifying the aforementioned radio bearer, an uplink cell identifier (for example, PCI) or an uplink second base station SCell index or an uplink eNB identifier or a cell / base station to which the UE will transmit uplink traffic. Upon receiving the index / division information, the uplink traffic of the radio bearer is transmitted through the cell or the second base station SCell or the secondary component carrier (SCC) or the cell group associated with the base station or the base station based on the radio bearer modification information. I can deliver it. The downlink traffic of the radio bearer may be transmitted through a macro cell, a PCC, or a first base station. Alternatively, downlink traffic of the corresponding radio bearer may be transmitted through a serving cell or a serving cell eNB. For example, the downlink traffic of the radio bearer may be transmitted through a cell group associated with the first base station and the second base station or the first base station and a cell group associated with the second base station.

If the UE further modifies the radio bearer, the aforementioned uplink cell identifier (for example, PCI) or uplink SCell index or uplink eNB identifier or cell / base station for the UE to transmit uplink traffic is used. When receiving radio resource configuration information that does not include index / division information, the radio bearer may be transmitted without distinguishing the uplink and the downlink. That is, the radio bearer may be delivered through a macro cell, a primary component carrier (PCC), or a first base station. Alternatively, the radio bearer may be delivered through a serving cell or a serving cell eNB. For example, it may be delivered through a first base station and a second base station, or a cell group associated with the first base station and a cell group associated with the second base station.

The information included in the above-described radio bearer addition modification list (drb-ToAddModList) may be applied to the first base station and the second base station before the first base station operating as the PCell adds / modifies and / or releases the radio bearer through the RRC Connection Reconfiguration procedure. Can be created through a procedure via an inter X2 interface.

9 is a diagram showing another example of radio resource configuration information according to the present invention.

Referring to FIG. 9, the radio bearer add modification information (DRB-ToAddMod) included in the above-described radio resource configuration information may be an uplink cell identifier (eg, PCI) or an uplink SCell index or an uplink eNB identifier or UE. It may include index / division information for identifying a cell / base station to carry uplink traffic. For example, the ENBIndex may be configured to have an integer value between 1 and 5 as a specific base station index value for transmitting uplink traffic. As another example, the ENBIndex may be configured to have a value of True if configured to transmit uplink traffic only through the second base station, and False otherwise (eg, configured to transmit uplink traffic only through the first base station). As another example, the ENBIndex is a value for distinguishing the configuration of transmitting uplink traffic only through the second base station, a value for distinguishing the configuration of transmitting uplink traffic only through the first base station, the first base station and the second. It may be configured to be able to distinguish a value for distinguishing what is configured to transmit uplink traffic through the base station. As another example, ENBIndex may have a list of indices as a value. For example, ENBIndex may include two index values when processing downlink traffic through two base stations.

How to include uplink / downlink classification information in RadioResourceConfigDedicated.

A first base station operating as a PCell is a first base station providing a cell operating as a PCell by using a radio bearer modification list (DRB-ToAddModList) or a radio bearer release list (DRB-ToReleaseList) of radio resource configuration information (RadioResourceConfigDedicated). And / or configure a radio resource for a second base station providing a cell that operates as a second base station SCell (or serving cell). For example, a specific radio bearer of a first base station providing a cell operating as a PCell may be added / modified to a second base station operating as a first base station and / or a second base station SCell (or serving cell). .

For example, in the connection structure as shown in FIG. 6, the wireless bearer additional modification information DRB-ToAddMod of the wireless bearer addition modification list drb-ToAddModList is eps-BearerIdentity (EPS bearer identifier), drb-Identity, and PDCP configuration information. (pdcp-Config), one or more of RLC configuration information (rlc-Config), logicalChannelIdentity, and logicalChannelConfig for the RLC entity peered to the first base station RLC entity and the RLC entity peered to the second base station RLC entity. .

As another example, in the connection structure as shown in FIG. 7, the radio bearer modification information DRB-ToAddMod of the radio bearer addition modification list drb-ToAddModList may be eps-BearerIdentity (EPS bearer identifier), drb-Identity, second base station. One or more of PDCP entity configuration information (pdcp-Config) peered to the PDCP entity, RLC entity configuration information (rlc-Config) peered to the second base station RLC entity, logicalChannelIdentity, logicalChannelConfig.

The first base station providing a cell operating as a PCell is a cell identifier (eg, PCI) in the radio bearer modification information (DRB-ToAddMod) to separate and transmit uplink traffic and downlink traffic for a specific radio bearer. Alternatively, the second base station SCell index or eNB identifier or UE may include index / division information for identifying a cell / base station. Alternatively, the first base station separates uplink traffic and downlink traffic for a specific radio bearer and delivers it through a specific cell or a specific second base station SCell or a specific CC or a specific eNB, so as to add radio bearer modification information (DRB-ToAddMod). The cell identifier (eg, PCI) or the second base station SCell index or the eNB identifier or the UE may include index / division information for identifying the cell / base station. In addition, the radio bearer additional modification information may further include uplink / downlink discrimination information (eg, UpDownIndicator).

In further modifying the above-described radio bearer, the UE may transmit uplink (or downlink) traffic of the radio bearer through a specific cell or a specific SCell or a specific CC or a specific eNB according to uplink / downlink classification information. For example, if the uplink / downlink discrimination information is set to a downlink value, the downlink traffic of the radio bearer may be transmitted only through the cell / base station included in the radio bearer modification information (DRB-ToAddMod). have. As another example, when the uplink / downlink classification information is set to a bidirectional value, the uplink and downlink traffic of the radio bearer may be transmitted only through the cell / base station included in the radio bearer modification information (DRB-ToAddMod). have.

The information included in the drb-ToAddModList includes X2 between the first base station and the second base station before the first base station operating as a PCell adds / modifies and / or releases the radio bearer through the RRC Connection Reconfiguration procedure. Can be created through a procedure through an interface.

10 is a diagram showing another example of radio resource configuration information according to the present invention.

Referring to FIG. 10, radio resource configuration information may be defined in a cell identifier (for example, PCI) or a second base station SCell index or an eNB identifier or a UE in a radio bearer additional modification information (DRB-ToAddMod). Index / division information and uplink / downlink division information may be included.

For example, uplink / downlink discrimination information (eg, UpDownIndicator) may be divided into uplink, downlink, and / or bidirectional (uplink / downlink) through an integer value of 0 to 3. For example, if the uplink / downlink discrimination is set to an uplink value, uplink traffic of the radio bearer is transmitted only through the cell or the second base station SCell or the cell group associated with the base station or the base station. You can do that. In this case, downlink traffic may be delivered through a first base station or a macrocell. Or in this case, the downlink traffic may be delivered through the serving cell base station or the serving cell. That is, downlink traffic may be delivered through a first base station and a second base station, or through a cell associated with the first base station and a cell associated with the second base station.

If the above-mentioned uplink / downlink classification information is set to a downlink value, the downlink traffic of the radio bearer is transmitted only through the cell or the second base station SCell or the cell group associated with the base station or the base station. can do. In this case, uplink traffic may be delivered through the first base station or the macrocell. Or, in this case, uplink traffic may be delivered through the serving cell base station or the serving cell. That is, uplink traffic may be delivered through a first base station and a second base station, or through a cell associated with the first base station and a cell associated with the second base station.

If the uplink / downlink discrimination information is set to a bidirectional value, the uplink traffic and the downlink traffic of the radio bearer are transmitted only through the cell or the second base station SCell or the cell group associated with the base station or the base station. You can do that.

As another example, uplink / downlink discrimination information (eg, UpDownIndicator) may deliver traffic by classifying uplink and downlink through an integer value of 0 to 1 or a true / false value. For example, if the uplink / downlink discrimination information is set to 0 or True, uplink traffic may be delivered only through the cell or the corresponding second base station SCell or the cell group associated with the corresponding base station or the corresponding base station. In this case, the downlink traffic may be delivered through the first base station or macrocell. Or, in this case, the downlink traffic may be transmitted through the serving cell base station or the serving cell. That is, downlink traffic may be delivered through a first base station and a second base station, or through a cell group associated with the first base station and a cell group associated with the second base station.

If the uplink / downlink classification information is set to 1 or False, the downlink traffic may be transmitted only through the cell or the second base station SCell or the cell group associated with the base station or the base station. In this case, uplink traffic may be delivered through the first base station or macrocell. Or, in this case, uplink traffic may be delivered through the serving cell base station or the serving cell. That is, uplink traffic may be delivered through a first base station and a second base station, or through a cell group associated with the first base station and a cell group associated with the second base station.

A method of including uplink cell index and downlink cell index in the SeNB / SCell radio resource configuration information (RadioResourceConfigDedicatedSeNB / RadioResourceConfigDedicatedSCell).

A first base station providing a cell operating as a PCell operates as a PCell by using a radio bearer addition modification list (DRB -ToAddModList) or a radio bearer release list (DRB -ToReleaseList) of the first base station Radio Resource Configuration Information (RadioResourceConfigDedicated). Radio resources may be configured for a first base station providing a cell. The first base station providing a cell operating as a PCell adds a radio bearer additional modified list (DRB -ToAddModList) to a second base station radio resource configuration information (RadioResourceConfigDedicatedSeNB / RadioResourceConfigDedicatedSCell) or delivers a radio bearer through a second base station SCell. Radio resource may be configured for a second base station providing a cell that operates as a second base station SCell by adding information for indicating the information.

For example, a specific radio bearer of a first base station providing a cell operating as a PCell may be configured in addition to a second base station providing a cell operating as a first base station and / or a second base station SCell (or serving cell). Can be.

For example, radio resources may be configured for the first base station and / or the second base station by adding a radio bearer additional modified list (DRB-ToAddModList) to the second base station radio resource configuration information (RadioResourceConfigDedicatedSeNB / RadioResourceConfigDedicatedSCell). The radio bearer addition modification list DRB-ToAddModList may be configured in the same manner as described above.

A first base station providing a cell operating as a PCell may separate uplink traffic and downlink traffic for a specific radio bearer and transmit the uplink cell identifier (eg, uplink cell identifier) to the radio bearer modification information (DRB-ToAddMod). , PCI) / downlink cell identifier (e.g. PCI) or uplink SCell index / downlink SCell index or uplink eNB identifier / downlink eNB identifier or for the UE to distinguish the uplink / downlink cell / base station. It may include index / division information. Alternatively, the first base station separates the uplink traffic and the downlink traffic for a specific radio bearer and delivers the radio bearer additional modification information (DRB-ToAddMod) for delivery through a specific cell or a specific second base station SCell or a specific CC or a specific eNB. Uplink cell identifier (eg PCI) / downlink cell identifier (eg PCI) or uplink SCell index / downlink SCell index or uplink eNB identifier / downlink eNB identifier or UE uplink / It may also include index / division information for identifying the downlink cell / base station.

Uplink cell identifier (eg PCI) / downlink cell identifier (eg PCI) or uplink SCell index / downlink SCell (or PCell) index or uplink by the UE in further modification of the radio bearer described above. When the link eNB identifier / downlink eNB identifier or the UE receives the index / division information for distinguishing the uplink / downlink cell / base station, the uplink / downlink traffic of the corresponding radio bearer is respectively applied to the corresponding uplink cell / downlink. Cell or uplink SCell / downlink SCell or uplink CC / downlink CC or uplink eNB / downlink eNB can be delivered separately.

If the UE further modifies the radio bearer, an uplink cell identifier (eg PCI) / downlink cell identifier (eg PCI) or an uplink SCell index / downlink SCell index or uplink eNB identifier When the downlink eNB identifier or the UE receives radio resource configuration information that does not include an index / division information for distinguishing an uplink / downlink cell / base station, the corresponding radio bearer forwards without distinguishing the uplink and the downlink. Can be. That is, the radio bearer may be delivered through a macro cell, a primary component carrier (PCC), or a first base station. Alternatively, the radio bearer may be delivered through a serving cell or a serving cell eNB. For example, it may be delivered through a cell group associated with the first base station and the second base station or the first base station and a cell group associated with the second base station.

The information included in the above-described radio bearer addition modification list (drb-ToAddModList) may be used before the first base station providing a cell operating as a PCell before adding / modifying and / or releasing the radio bearer through the RRC Connection Reconfiguration procedure. It may be generated through a procedure through the X2 interface between the second base station.

11 is a diagram showing another example of radio resource configuration information according to the present invention.

Referring to FIG. 11, the above-described radio resource configuration information may be defined in a cell identifier (eg, PCI) or a second base station SCell index or an eNB identifier or a UE in a radio bearer additional modification information (DRB-ToAddMod). It may include an index / classification information for.

For example, the ENBIndex may be configured to have an integer value between 1 and 5 as a specific base station index value to transmit uplink traffic. As another example, the ENBIndex may be configured to have a value of True if configured to transmit uplink traffic only through the second base station, and False otherwise (eg, configured to transmit uplink traffic only through the first base station). As another example, ENBIndex is a value for distinguishing configuration of transmitting uplink traffic only through a second base station, a value for distinguishing configuration of transmitting uplink traffic only through a first base station, a first base station and a second base station. It may be configured to identify a value for distinguishing the configuration to transmit the uplink traffic through.

Alternatively, the first base station providing a cell operating as a PCell may separate the uplink traffic and the downlink traffic for a specific radio bearer and transmit the uplink cell identifier (DRB-ToAddMod) to the uplink cell identifier (DRB-ToAddMod). For example, PCI) or uplink second base station SCell index or uplink eNB identifier or the UE may include the index / classification information for identifying the cell / base station to carry the uplink traffic. Alternatively, the first base station separates uplink traffic for a specific radio bearer and delivers the uplink cell identifier (eg, PCI) to the radio bearer additional modification information (DRB-ToAddMod) to deliver the small cell configured with the second base station SCell. Or uplink second base station SCell index or uplink eNB identifier or index / division information for identifying the cell / base station to which the UE will carry uplink traffic. Alternatively, the first base station separates uplink traffic for a specific radio bearer and delivers the uplink to the radio bearer additional modification information (DRB-ToAddMod) for delivery through a specific cell or a specific second base station SCell or a specific CC or a specific eNB. The cell identifier (eg PCI) or the uplink second base station SCell index or uplink eNB identifier or the UE may include index / division information for identifying the cell / base station to which the uplink traffic will be delivered.

If the UE further modifies the radio bearer, the aforementioned uplink cell identifier (eg, PCI) or uplink second base station SCell index or uplink eNB identifier or cell / base station to which the UE will carry uplink traffic is identified. When receiving the index / division information, the uplink traffic of the corresponding radio bearer may be transmitted through the aforementioned cell or the second base station SCell or SCC or eNB. In addition, downlink traffic of the radio bearer may be transmitted through a macro cell, a PCC, or a first base station. Alternatively, downlink traffic of the corresponding radio bearer may be transmitted through a serving cell or a serving cell eNB. For example, the downlink traffic of the radio bearer may be transmitted through a cell group associated with the first base station and the second base station or the first base station and a cell group associated with the second base station.

If the UE further modifies the radio bearer, an uplink cell identifier (eg, PCI) or an uplink SCell index or an uplink eNB identifier or an index / division for identifying a cell / base station to which the UE will carry uplink traffic. When receiving radio resource configuration information that does not include the information, the radio bearer may be transmitted without distinguishing the uplink and the downlink. That is, the radio bearer may be delivered through a macro cell, a primary component carrier (PCC), or a first base station. Alternatively, the radio bearer may be delivered through a serving cell or a serving cell eNB. For example, it may be delivered through a cell group associated with the first base station and the second base station or the first base station and a cell group associated with the second base station.

The information included in the drb-ToAddModList includes X2 between the first base station and the second base station before the first base station operating as a PCell adds / modifies and / or releases the radio bearer through the RRC Connection Reconfiguration procedure. Can be created through a procedure through an interface.

12 is a diagram showing another example of radio resource configuration information according to the present invention.

Referring to FIG. 12, the above-described second base station radio resource configuration information may be included in a cell identifier (for example, PCI) or a second base station SCell index or eNB identifier or a UE in a radio bearer addition modification information (DRB-ToAddMod). It may include index / division information for identifying the base station. For example, the ENBIndex may be configured to have an integer value between 1 and 5 as a specific base station index value to transmit uplink traffic. As another example, the ENBIndex may be configured to have a value of True if configured to transmit uplink traffic only through the second base station, and False otherwise (eg, configured to transmit uplink traffic only through the first base station). As another example, ENBIndex is a value for distinguishing configuration of transmitting uplink traffic only through a second base station, a value for distinguishing configuration of transmitting uplink traffic only through a first base station, a first base station and a second base station. It may be configured to identify a value for distinguishing the configuration to transmit the uplink traffic through.

A method of including uplink / downlink discrimination information in SeNB / SCell radio resource configuration information (RadioResourceConfigDedicatedSeNB / RadioResourceConfigDedicatedSCell).

A first base station providing a cell operating as a PCell operates as a PCell by using a radio bearer addition modification list (DRB -ToAddModList) or a radio bearer release list (DRB -ToReleaseList) of the first base station Radio Resource Configuration Information (RadioResourceConfigDedicated). Radio resources can be configured for the first base station. The first base station operating as a PCell adds a radio bearer modified list (DRB-ToAddModList) to the second base station radio resource configuration information (RadioResourceConfigDedicatedSeNB / RadioResourceConfigDedicatedSCell) or indicates that a radio bearer is delivered through a second base station SCell. By adding information, a radio resource may be configured for a second base station providing a cell that operates as an SCell.

For example, a specific radio bearer of a first base station providing a cell operating as a PCell may be configured in addition to a second base station providing a cell operating as a first base station and / or a second base station SCell (or serving cell). Can be.

As an example, radio resources may be configured for the first base station and / or the second base station by adding a radio bearer additional modified list (DRB-ToAddModList) to the second base station radio resource configuration information (RadioResourceConfigDedicatedSeNB / RadioResourceConfigDedicatedSCell). The radio bearer addition modification list DRB-ToAddModList may be configured in the same manner as in the above-described method.

The first base station providing a cell operating as a PCell is a cell identifier (eg, PCI) in the radio bearer modification information (DRB-ToAddMod) to separate and transmit uplink traffic and downlink traffic for a specific radio bearer. Alternatively, the second base station SCell index or eNB identifier or UE may include index / division information for identifying a cell / base station. Alternatively, the first base station separates the uplink traffic and the downlink traffic for a specific radio bearer and delivers the same through a specific cell or a specific SCell or a specific CC or a specific eNB, and the cell identifier in the DRB-ToAddMod. (Eg, PCI) or a second base station SCell index or eNB identifier or UE may include index / division information for distinguishing a cell / base station. In addition, the radio bearer additional modification information may further include uplink / downlink discrimination information (eg, UpDownIndicator).

As another example, the radio bearer modification information may be included in a cell identifier (e.g., PCI) or a second base station SCell index or eNB identifier or a UE only when it is included in the information of the radio resource configuration dedicated (RadioResourceConfigDedicatedSeNB / RadioResourceConfigDedicatedSCell). It may also include index / division information for identifying the base station.

In further modifying the above-described radio bearer, the UE transmits uplink (or downlink) traffic of the radio bearer according to uplink / downlink discrimination information to a specific cell or a specific second base station SCell or a specific CC or a specific eNB or a specific eNB. Can be delivered through a group of cells associated with.

For example, if the uplink / downlink segmentation information is set to an uplink value, the uplink traffic for that radio bearer will be delivered only through the cell / base station included in the radio bearer modification information (DRB-ToAddMod). Can be. In this case, downlink traffic for the radio bearer may be delivered through the first base station or the macrocell. Or, in this case, the downlink traffic for the radio bearer may be transmitted through the serving cell base station or the serving cell. That is, downlink traffic for the radio bearer may be delivered through a first base station and a second base station, or a cell group associated with the first base station and a cell group associated with the second base station.

If the uplink / downlink classification information is set to a downlink value, the downlink traffic for the radio bearer may be transmitted only through the cell / base station included in the radio bearer modification information DRB-ToAddMod. In this case, the uplink traffic for the radio bearer may be delivered through the first base station or the macro cell. Or, in this case, the uplink traffic for the radio bearer may be transmitted through the serving cell base station or the serving cell. That is, uplink traffic for the radio bearer may be delivered through a first base station and a second base station, or a cell group associated with the first base station and a cell group associated with the second base station.

If the uplink / downlink classification information is set to a bidirectional value, the uplink traffic and the downlink traffic for the corresponding radio bearer will be transmitted only through the cell / base station included in the radio bearer modification information (DRB-ToAddMod). Can be.

The information included in the drb-ToAddModList includes X2 between the first base station and the second base station before the first base station operating as a PCell adds / modifies and / or releases the radio bearer through the RRC Connection Reconfiguration procedure. Can be created through a procedure through an interface.

13 is a view showing another example of radio resource configuration information according to the present invention.

Referring to FIG. 13, the second base station radio resource configuration information may be included in a cell identifier (for example, PCI) or a second base station SCell index or an eNB identifier or a UE in the radio bearer modification information (DRB-ToAddMod). It may include index / division information and uplink / downlink discrimination information for discriminating.

For example, uplink / downlink discrimination information (eg, UpDownIndicator) may distinguish uplink, downlink, and / or bidirectional (uplink / downlink) through an integer value of 0-3.

If the uplink / downlink classification information is set to an uplink value, the uplink traffic of the radio bearer may be transmitted only through the cell or the second base station SCell or the cell associated with the base station or the base station. In this case, the downlink traffic may be delivered through the first base station or macrocell. Or, in this case, the downlink traffic may be transmitted through the serving cell base station or the serving cell. That is, downlink traffic may be delivered through a first base station and a second base station, or through a cell group associated with the first base station and a cell group associated with the second base station.

If the uplink / downlink classification information is set to a downlink value, downlink traffic of the radio bearer may be transmitted only through the cell or the second base station SCell or the cell group associated with the base station or the base station. . In this case, uplink traffic may be delivered through the first base station or the macrocell. Or, in this case, uplink traffic may be transmitted through the serving cell base station or the serving cell. That is, uplink traffic may be delivered through a first base station and a second base station, or through a cell group associated with the first base station and a cell group associated with the second base station.

If the uplink / downlink discrimination information is set to a bidirectional value, the uplink traffic and the downlink traffic of the radio bearer are transmitted only through the cell or the second base station SCell or the cell group associated with the base station or the base station. Can be.

For another example, the uplink / downlink discrimination information (e.g. UpDownIndicator) may deliver traffic by classifying uplink and downlink through an integer value of 0 to 1 or true / false value.

If the uplink / downlink discrimination information is set to 0 or True, uplink traffic may be delivered through the cell or the second base station SCell or the cell group associated with the base station or the base station. In this case, the downlink traffic may be delivered through the first base station or macrocell. Or, in this case, the downlink traffic may be delivered through the serving cell base station or the serving cell. That is, downlink traffic may be delivered through a first base station and a second base station, or through a cell group associated with the first base station and a cell group associated with the second base station.

If the uplink / downlink classification information is set to 1 or False, the downlink traffic may be transmitted through the cell or the second base station SCell or the cell group associated with the base station or the base station. In this case, uplink traffic may be delivered through the first base station or the macrocell. Or, in this case, uplink traffic may be delivered through the serving cell base station or the serving cell. That is, uplink traffic may be delivered through a first base station and a second base station, or through a cell group associated with the first base station and a cell group associated with the second base station.

Second embodiment: A method of separating uplink traffic transmission path by cell, CC, or eNB.

A method for including SCell uplink / downlink classification information in the second base station SCell information (SeNBSCellToAddMod) to be added / modified.

When the UE establishes an RRC connection with a first base station providing a cell that operates as a PCell and is in an RRC Connected state, the UE sets a cell associated with a second base station connected through a non-ideal backhaul to a second base station SCell (or serving cell). Can be added as

After the first base station providing a cell acting as a PCell detects a new second base station SCell candidate, to add cells associated with the second base station to the second base station SCell, or to modify the configured second base station SCell; Upon determining the base station SCell addition / modification, the first base station operating as the PCell adds / modifies the second base station SCell through the RRC Connection Reconfiguration procedure.

If the UE includes a second base station SCell list (SeNBSCellToAddModList) to be added / modified to the received RRC Connection Reconfiguration message, the UE performs addition or modification of the second base station SCell.

The first base station providing a cell operating as a PCell includes the following information in the SCell information (SeNBSCellToAddMod) to be added / modified in the second base station SCell list to be added / modified in order to separate and transmit uplink traffic and downlink traffic. Can be. Alternatively, the first base station operating as a PCell may add / modify the above-described second base station SCell list to be added / modified to separate the uplink traffic and the downlink traffic and deliver them through a specific cell or a specific SCell or a specific CC or a specific eNB. SCell information (SeNBSCellToAddMod) may include the following information.

Second Base Station SCell Index (SeNBSCellIndex): Contains index information used to identify one second base station SCell within second base station SCells configured for the UE.

■ Cell Identification (CellIdentification): Includes Physical Cell ID (PCI) and Absolute Radio Frequency Channel Number (ARFCN) information of the second base station SCell.

■ Radio Resource Configuration Common SCell Information (radioResourceConfigCommonScell): The essential information for the UE to operate in the SCell is the common radio resource configuration information (eg, physical layer parameters, random access parameters) in the system information (System information). Include.

Radio resource configuration dedicated SCell information (radioResourceConfigDedicatedSCell): Contains UE-specific configuration information applicable to the SCell (for example, physicalConfigDedicatedSCell, mac-MainConfigSCell).

■ Uplink / downlink distinguishing information (eg, UpDownIndicatorSeNB, UpDownIndicatorSCell) of the second base station or the second base station SCell: for the direction (uplink / downlink) of traffic to be transmitted through the second base station or the second base station SCell. Contains identifying information.

The cell information (cell addition modification information) to be added so that the terminal can distinguish the second base station SCell from the base station SCell linked to the existing PCell may include the second base station identification information. Alternatively, the second base station SCell index value may be set differently from the SCell index value of the base station linked to the existing PCell to distinguish the cell associated with the second base station. For example, in order to use a value other than the value used as the SCell index of the base station linked to the existing PCell, the SCell index, which can have an integer value from 1 to 7, currently has an integer value from 1 to 14 You can do that. An integer value of 1 to 7 may be used as an index for SCells of a base station linked to a PCell, and 8 to 14 may be used as an index for a second base station. Alternatively, in order to distinguish between the SCell index of the base station linked to the PCell and the SCell index of the second base station, the SCell index and the indication information field indicating that the SCell through the second base station may be transmitted together.

If the second base station SCell index included in the above-described second base station SCell information to be added / modified is not a current UE configuration part, the UE is included in the received radio resource configuration common SCell information and the radio resource configuration dedicated SCell information. Accordingly, the second base station SCell corresponding to the cell identifier is added. That is, when the second base station SCell index is not the second base station SCell configured for the UE, the second base station SCell corresponding to the cell identifier is added according to the received radio resource configuration common SCell information and radio resource configuration dedicated SCell information.

The UE modifies the second base station SCell according to the received radio resource configuration-specific SCell information when the second base station SCell index included in the second base station SCell information to be added / modified is a current UE configuration part. That is, when the second base station SCell index is the second base station SCell configured for the UE, the second base station SCell is modified according to the received radio resource configuration dedicated SCell information.

The information included in the above-described second base station SCell information to be added / modified is the first base station and the second base station before the first base station providing the cell operating as the PCell adds / modifies the second base station SCell through the RRC Connection Reconfiguration procedure. Interrogation can be made through the X2 interface. Alternatively, the information included in the second base station SCell information to be added / modified is pre-configured in the first base station providing a cell operating as a PCell, stored in advance through operations, administration and maintenance (OAM), or a previous second base station. It may be stored and used in the SCell add / modify procedure.

The second base station SCell information described above may be configured as shown in FIG. 14.

14 is a diagram illustrating an example of SeNBSCellToAddMod according to the present invention.

Referring to FIG. 14, the above-described second base station SCell information (SeNBSCellToAddMod) to be added / modified may be configured to include SCell uplink / downlink classification information.

For example, uplink / downlink discrimination information (eg, UpDownIndicatorSeNB or UpDownIndicatorSCell) of the second base station or the second base station SCell may be uplink, downlink, and / or bidirectional (through an integer value of 0 to 3). Uplink / downlink).

If the uplink / downlink discrimination information of the second base station or the second base station SCell is set to an uplink value, the uplink traffic of all user plane data is associated with the second base station or the second base station SCell or the second base station. It can only be transmitted through cell groups. In this case, downlink traffic may be delivered through a first base station or a macrocell. Or, in this case, the downlink traffic may be transmitted through the serving cell base station or the serving cell. That is, downlink traffic may be delivered through a first base station and a second base station, or through a cell associated with the first base station and a cell associated with the second base station.

If the uplink / downlink discrimination information is set to a downlink value, downlink traffic of all user plane data may be transmitted only through the second base station or the second base station SCell or the cell group associated with the second base station. In this case, uplink traffic may be delivered through the first base station or macrocell. Or, in this case, uplink traffic may be transmitted through the serving cell base station or the serving cell. That is, uplink traffic may be delivered through a first base station and a second base station, or through a cell group associated with the first base station and a cell group associated with the second base station.

If the uplink / downlink discrimination information is set to a bidirectional value, the uplink traffic and the downlink traffic of all user plane data may be transmitted only through the second base station or the second base station SCell or the cell group associated with the second base station. can do.

For another example, the above-described second base station or second base station SCell uplink / downlink discrimination information (eg, UpDownIndicatorSeNB or UpDownIndicatorSCell) may be uplink or downlink through an integer value of 0 to 1 or a True / False value. To separate traffic.

If the second base station or the second base station SCell uplink / downlink discrimination information is set to 0 or True, uplink traffic may be delivered through the cell group associated with the second base station or the second base station SCell or the second base station. Can be. In this case, the downlink traffic may be delivered through the first base station or macrocell. Or, in this case, the downlink traffic may be transmitted through the serving cell base station or the serving cell. That is, downlink traffic may be delivered through a first base station and a second base station, or through a cell group associated with the first base station and a cell group associated with the second base station.

If the second base station or second base station SCell uplink / downlink discrimination information is set to 1 or False, downlink traffic may be delivered through a cell group associated with the second base station or the second base station SCell or the second base station. Can be. In this case, uplink traffic may be delivered through a macrocell base station or a macrocell. Or, in this case, uplink traffic may be transmitted through the serving cell base station or the serving cell. That is, uplink traffic may be delivered through a first base station and a second base station, or through a cell group associated with the first base station and a cell group associated with the second base station.

In the above, radio resource configuration information and a second base station SCell addition / modification procedure for separating and transmitting uplink and downlink traffic transmission / reception paths according to embodiments of the present invention have been described.

Hereinafter, a network structure for separating and forwarding an uplink traffic path and a downlink traffic path in transmitting user plane data traffic of the present invention, setting RLC configuration information through an RRC reconfiguration message, and a logical channel priority procedure Each embodiment will be described with reference to the drawings.

15 is a diagram illustrating a layer 2 structure of a master base station and a secondary base station according to an embodiment of the present invention;

FIG. 15 illustrates a Layer2 protocol structure of a first base station (macrocell eNB) and a second base station (small cell eNB) for separately transmitting an uplink traffic path and a downlink traffic path.

Referring to FIG. 15, downlink traffic is transmitted through a first base station and uplink data traffic is transmitted through a second base station for one data radio bearer (DRB). When processing a plurality of DRBs can be applied similarly to the configuration of FIG.

Specifically, the first base station generates one PDCP entity for one DRB in the PDCP layer. An RLC entity for processing downlink traffic and one RLC entity for processing uplink traffic may be separated from a Radio Link Control (RLC) layer that performs segmentation and ARQ (Automatic Repeat ReQeuest). That is, for the Acknowledgment Mode (AM) RLC processing, the first base station may have an entity (or an entity for AM RLC processing in the first base station) for the Acknowledgment Mode (AM) RLC processing for the downlink data. The second base station may have an entity (or entity for AM RLC processing in the second base station) for AM (Acknowledged Mode) RLC processing on the uplink data.

Entity (or entity for AM RLC processing in the first base station) and the entity for AM (Acknowledged Mode) RLC processing for uplink data described above The entity for AM RLC processing in the second base station may perform an Automatic Repeat ReQeuest (ARQ) operation through a backhaul between the first base station and the second base station. For example, a DL AM RLC entity (or entity for AM RLC processing in a first base station) for downlink traffic may be received via a UL AM RLC entity (or entity for AM RLC processing in a second base station). Retransmission may be performed based on the feedback (eg, RLC status report). That is, the AM RLC entity may send a status report to its peer AM RLC entity to provide positive and / or negative acknowledgments of the RLC PDUs. In other words, an entity for downlink Acknowledgment Mode (AM) RLC processing of the UE (or an entity for in-terminal AM RLC processing peered to an entity for AM RLC processing in the first base station) is received through the first base station. Transmit positive and / or negative acknowledgments of downlink RLC PDUs through the second base station. As shown in FIG. 15, the entity for downlink Acknowledgment Mode (AM) RLC processing of the UE is a DL AM RLC entity (or an AM RLC entity in the first base station) for downlink traffic in the first base station through the second base station. You can send a status report to.

The first base station may have one or more Hybrid automatic repeat request (HARQ) entities to deliver downlink traffic and related control information (eg, L1 control information). The second base station may have one or more Hybrid automatic repeat request (HARQ) entities to deliver uplink traffic and related control information (eg, L1 control information).

16 is a diagram illustrating a layer 2 structure of a master base station and a secondary base station according to another embodiment of the present invention.

16 shows another example of a Layer 2 protocol structure of a first base station (macrocell eNB) and a second base station (small cell eNB) for separately transmitting uplink traffic and downlink traffic according to the present invention.

Referring to FIG. 16, downlink traffic for one data radio bearer (DRB) is delivered through a first base station (macrocell eNB) and a second base station (small cell eNB), and uplink data traffic is transmitted to the second base station. Is passed through. 16 may be similarly applied to processing a plurality of DRBs.

Specifically, the first base station generates one PDCP entity for one DRB in the PDCP layer. In order to process an acknowledgment mode (AM) RLC for one DRB in a radio link control (RLC) layer that performs segmentation and automatic repeat reQeuest (ARQ), the first base station performs an acknowledgment mode (AM) RLC for downlink traffic. It may have an entity for processing (or an entity for AM RLC processing in the first base station). The second base station may have an entity (or entity for AM RLC processing in the second base station) for AM (Acknowledged Mode) RLC processing for uplink traffic and downlink traffic.

The entity for AM RLC processing in the first base station and the entity for AM RLC processing in the second base station are each operated by Automatic Repeat ReQeuest (ARQ) through a cell associated with the first base station and a cell associated with the second base station. Can be performed. For example, an entity for AM RLC processing in a first base station configured in a first base station sends an RLC PDU for downlink user plane data traffic through a macrocell or a group of cells associated with the first base station or PCC or the first base station. Can be. In addition, the entity for AM RLC processing in the first base station configured in the first base station is the feedback of the RLC receiver for downlink traffic received through the macrocell or the first base station or a cell group associated with the PCC or the first base station (one For example, retransmission may be performed based on an RLC status report. The entity for AM RLC processing in the second base station configured in the second base station transmits and receives RLC PDUs for uplink and downlink user plane data traffic through the small cell or the cell associated with the second base station or the SCC or the second base station. . In addition, the entity for AM RLC processing in the second base station is the feedback of the RLC receiver for uplink traffic received through the small cell or the second base station or the cell associated with the SCC or the second base station (eg, RLC status report) Can be sent to the UE. In addition, the entity for AM RLC processing in the second base station is the feedback of the RLC receiver for downlink traffic transmitted through the small cell or the second base station or the cell associated with the SCC or the second base station (eg, RLC status report) Through RLC retransmission can be performed.

The first base station may have one or more Hybrid automatic repeat request (HARQ) entities to deliver downlink traffic and related feedback (and / or control information). The second base station may have one or more Hybrid automatic repeat request (HARQ) entities to convey uplink and downlink traffic and associated feedback (and / or control information).

17 is a diagram illustrating a layer 2 structure of a terminal according to another embodiment of the present invention.

Referring to FIG. 17, the terminal may have a Layer2 protocol structure for separately transmitting uplink traffic and downlink traffic.

Specifically, one PDCP entity is created in the PDCP layer for one data radio bearer (DRB). The terminal is a cell associated with a macrocell or a first base station (macrocell eNB) or a PCC or a first base station for processing an acknowledgment mode (AM) RLC in a Radio Link Control (RLC) layer for one data radio bearer (DRB). Group for uplink and downlink traffic through the small cell or second base station (small cell eNB) or SCC and the entity for the Acknowledgment Mode (AM) RLC processing of downlink traffic through the group (the entity peered to the MeNB AM RLC entity). It may have an entity for an AM (Acknowledged Mode) RLC processing (an entity peered to a SeNB AM RLC entity).

AM RLC entity for processing downlink traffic through a macrocell or a cell associated with a first base station or PCC or a first base station receives a downlink RLC PDU through a macrocell or cell associated with a first base station or PCC or a first base station In addition, a feedback (eg, an RLC status report) of an RLC receiver for downlink traffic through a macro cell or a cell group associated with the first base station or the PCC or the first base station may be transmitted to the first base station. The first base station may perform RLC retransmission based on the feedback of the RLC receiver for downlink traffic.

The AM RLC entity for processing uplink, downlink traffic through a small cell or a cell associated with a second base station or an SCC or a second base station is uplinked through a cell associated with the small cell or the second base station or an SCC or a second base station. The UE may transmit and receive downlink RLC PDUs. The UE may perform RLC retransmission based on feedback of an RLC receiver (eg, an RLC status report) to uplink user plane data traffic transmitted through a small cell or a second base station or a cell group associated with an SCC or a second base station. Can be.

In the MAC layer of the UE, logical channels for carrying uplink traffic through a small cell configured with a second base station SCell or a cell group associated with a second base station or a CC or a second base station of the small cell are transferred to the second base station SCell. It may be mapped to a transport channel (eg, an uplink shared channel, UL-SCH) through a configured small cell or a second base station or a cell group associated with a CC or a second base station of the small cell. The UE may have one or more Hybrid automatic repeat request (HARQ) entities to convey downlink traffic and related feedback (and / or control information). The UE may have one or more Hybrid automatic repeat request (HARQ) entities to convey uplink traffic and related feedback (and / or control information).

In FIG. 16 and FIG. 17, the uplink user plane data is transmitted only through the second base station. However, the transmission of uplink user plane data only through the first base station may be equally applied in the scope of the present invention. have.

As described above, the UE may configure an RLC entity peered with the first base station and the second base station, respectively. In addition, the UE may receive downlink traffic through the RLC entity peered to the RLC entity of the first base station and transmit uplink traffic through the RLC entity peered to the RLC entity of the second base station. . In another example, the UE may receive downlink traffic through an RLC entity peered to the RLC entity of the first base station and an RLC entity peered to the RLC entity of the second base station. However, the uplink traffic can be processed only through the RLC entity configured to be peered to the RLC entity of the second base station.

As described above, an RLC entity and a second base station for processing downlink traffic through a first base station for an acknowledgment mode (AM) RLC processing in a Radio Link Control (RLC) layer for one data radio bearer (DRB) When the RLC entity for processing uplink traffic (or uplink traffic and downlink traffic) is separated through the first base station, the first base station of the present invention divides it into radio bearer modification information (DRB-ToAddMod) of the RRC reconfiguration message. Information (for example, feedback AM-RLC information or uplink downlink division indication information or uplink cell / base station index / division information) may be included.

Hereinafter, each embodiment of the case in which the information for distinguishing this from the radio bearer addition modification information (DRB-ToAddMod) of the higher layer signaling (eg, RRC reconfiguration) message will be described with reference to the drawings.

18 illustrates an example of RLC-Config for AM RLC according to the present invention.

Referring to FIG. 18, the RRC reconfiguration message may include the above-described classification information in the RLC-Config information for the AM RLC included in the radio bearer addition modification information (DRB-ToAddMod).

For example, the aforementioned ul-AM-RLC-SeNB may include configuration information for an RLC entity that processes uplink traffic through a second base station. The dl-AM-RLC-SeNB may include configuration information for an RLC entity that processes downlink traffic through the second base station.

The ul-AM-RLC-MeNB-Feedback may include configuration information for an RLC entity for transmitting RLC feedback on the uplink through a first base station. The dl-AM-RLC-MeNB may include configuration information for an RLC entity that processes downlink traffic through the first base station.

19 shows another example of RLC-Config for AM RLC according to the present invention.

Referring to FIG. 19, the RRC reconfiguration message may include RLC-Config information for AM RLC in radio bearer addition modification information (DRB-ToAddMod).

For example, the above-described up-down-split-indicator information may include information indicating uplink downlink separation, respectively. That is, it indicates that an RLC entity necessary for processing an RLC data or feedback information, which is peered to an RLC entity configured in each base station to an existing RLC entity, must be additionally configured.

20 shows another example of RLC-Config for AM RLC according to the present invention.

Referring to FIG. 20, an RRC reconfiguration message indicates an uplink cell identifier (eg, PCI) or an uplink second base station SCell for configuring a cell / base station to transmit uplink data to radio bearer modification information (DRB-ToAddMod). The index or uplink eNB identifier or the UE may include index / division information or uplink / downlink discrimination information for identifying an uplink cell / base station. When the above-described classification information is included, the RLC-Config information for the AM RLC may allow the UE to additionally configure an RLC entity according to the information before 3GPP Rel-11. For example, for a radio bearer having the same DRB-ID, the first base station radio resource configuration information (or radio bearer information included therein) is included in the first base station radio resource configuration information (or included therein) together with the first base station RLC-Config. Radio bearer information) may include a second base station RLC-Config.

In another example, the uplink cell identifier (eg, PCI) or uplink second base station SCell index or uplink eNB identifier or UE described in the radio bearer modification information (DRB-ToAddMod) of the RRC reconfiguration message may be assigned to an uplink cell / When the index / division information or uplink / downlink identification information for identifying a base station is included, the PDCP entity for the radio bearer may be an uplink cell identifier (eg, PCI) or an uplink second base station SCell index or A base station (e.g., a second base station) or a corresponding base station (e.g., a second base station) configured by an uplink eNB identifier or a UE through an index / division information or uplink / downlink identification for identifying an uplink cell / base station The PDCP PDU can be delivered to the AM RLC entity in the UE peered to the AM RLC entity configured in the cell associated with the C-P. In this manner, the terminal may transmit the uplink traffic for the corresponding radio bearer only through the second base station or a cell associated with the second base station.

In other words, the PDCP entity of the terminal is an AM RLC entity in the terminal peered to the RLC entity of the first base station or the second base station for uplink data transmission using one or more of the above-described index, identifier, and identification information. You can submit only.

That is, the PDCP entity of the terminal may submit the PDU as an AM RLC entity in the terminal peered to the RLC entity of the first base station or as an AM RLC entity in the terminal peered to the RLC entity of the second base station.

Hereinafter, the first base station or the second base station will be described as a specific base station.

The Logical Channel Prioritization (LCP) procedure is used to construct a MAC PDU by determining the amount of data from each logical channel and MAC control element type to be included in the MAC PDU.

As described above, in the MAC layer of the UE, logical channels for transmitting uplink traffic are transmitted through a small cell configured with a second base station SCell or a cell group associated with a second base station or a CC of a small cell or a second base station. It may be mapped to a transport channel (Uplink Shared Channel, UL-SCH) through a small cell configured with a 2 base station SCell or a cell group associated with a CC or a second base station of a second base station or a small cell.

The UE may perform a logical channel prioritization procedure for each cell group associated with the small cell configured with the second base station SCell or the second base station or the small cell CC or the second base station.

For example, the UE of the present invention may be applied to a specific small cell or a second base station or a small cell CC configured as an SCell in the following steps for each small cell or second base station or small cell CC configured as an SCell or for each cell group associated with the second base station. Resources may be allocated to logical channels to which they belong.

Step 1) The UE allocates resources in decreasing priority order to all logical channels of Bj> 0 belonging to a specific small cell or a second base station configured as an SCell or a cell group associated with the small cell CC or the second base station.

Step 2) The UE reduces Bj to the total size of MAC SDUs serviced in the logical channel of step 1.

Step 3) If the UE has any resources remaining, all logical channels belonging to a specific small cell or second base station or small cell CC configured as SCell are strict decreasing priority order until data or uplink grant for the logical channel is exhausted. Serviced.

For the logical channel priority procedure, the UE may consider the priority for each small cell or second base station or small cell CC configured with the SCell.

As described above, the present invention provides a mobile station through a small cell under the control of the macro cell or through cooperation between the macro cell and the small cell in an environment in which the macro cell and the small cell are established through separate eNBs through a non-ideal backhaul in a mobile communication network. Provided is a method for delivering user plane data using radio resources provided by the first base station and the second base station. In particular, the UE according to the present invention has an effect of transmitting uplink data traffic through a small cell consisting of a terminal and a second base station SCell having a low path loss, or a cell group associated with a second base station or a small cell CC or a second base station. have. Accordingly, the uplink buffer status reporting and Logical Channel Prioritization (LCP) procedure may be performed in a small cell configured with a second base station SCell or a second base station or small cell even under a dual connectivity structure through a first base station and a second base station. There is an effect that can be performed only for the cell group associated with the CC or the second base station.

21 is a signal diagram illustrating operations of a terminal and a base station according to another embodiment of the present invention.

An operation of a terminal, a first base station, and a second base station, in which each of the above-described embodiments can be performed, will be described by way of example with reference to FIG. 21.

The terminal 2101 may receive higher layer signaling from the first base station 2102 (S2110). For example, higher layer signaling may be an RRC Reconfiguration message. In addition, higher layer signaling is an index / identifier capable of distinguishing a specific base station (eg, a second base station) or a cell associated with a specific base station or a cell group associated with a specific base station to transmit uplink user plane data according to each of the above-described embodiments. / Delimited information, and the like.

The terminal 2101 may configure dual connectivity with the first base station 2102 and the second base station 2103. For example, as shown in FIGS. 6 and 7, the radio bearer through the first base station and the radio bearer through the second base station may be configured. In addition, it is possible to configure a radio bearer through both the first base station and the second base station. The radio bearer through both the first base station and the second base station may be split to the first base station and the second base station and configured similarly to FIG. 6. That is, one PDCP entity and one or more RLC entities peered to RLC entities of each of the first base station and the second base station may be configured.

In configuring dual connectivity, the terminal 2101 may configure an RLC entity peered to each base station.

The PDCP entity of the terminal 2101 may be configured by using the information included in the above-described higher layer signaling in submitting a PDCP PDU for uplink traffic to the RLC entity. That is, it may be transmitted to the RLC entity peered to the RLC entity of the specific base station (for example, the second base station) by using one or more information of the above-described index, identifier, and discrimination information (S2130).

The transmitted uplink data is transmitted to the second base station 2103 through the MAC layer (S2140).

In each step, the terminal, the first base station, and the second base station may be implemented with various modified steps or information according to the above-described embodiments.

The terminal of the present invention configures a dual connection including a first base station and a second base station and a split radio bearer, and downlink data can be received through the first base station and the second base station. When the terminal transmits uplink data, the terminal may transmit only to a specific base station (for example, the second base station).

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

In a method for transmitting uplink data by a terminal according to another embodiment of the present invention, receiving a higher layer signaling including information for configuring a dual connection with a first base station and a second base station and higher layer signaling Establishing dual connectivity with the first base station and the second base station based on the PDCP entity and peering the PDCP PDUs for each of the one or more radio bearers to a specific base station (e.g., a second base station) based on higher layer signaling And submitting to the configured RLC entity.

Referring to FIG. 22, the terminal may receive higher layer signaling including information for configuring dual connectivity with the first base station and the second base station (S2210). For example, higher layer signaling may include an index or identifying information for identifying an uplink cell or uplink base station for transmitting uplink data to a specific base station (eg, a second base station). That is, it may include one or more pieces of information of the index, the identifier, the identification information of each of the above-described embodiments. In addition, the higher layer signaling may include radio resource configuration information and may be an RRC reconfiguration message.

The terminal may configure a dual connection with the first base station and the second base station based on higher layer signaling (S2220). For example, the terminal may configure one or more RLC entities to form a dual connection with a plurality of base stations connected by non-ideal backhaul, configure a dedicated radio bearer with each base station, and split radio bearers with a plurality of base stations. bearer) may be configured.

Subsequently, the PDCP entity of the UE may further include submitting PDCP PDUs for each of the one or more radio bearers to an RLC entity peered to a specific base station (eg, a second base station) based on higher layer signaling (see FIG. S2230). For example, the one or more radio bearers may be radio bearers configured to be split into a first base station and a second base station. That is, in transmitting uplink user plane data, the PDCP entity of the terminal may submit a PDCP PDU to the RLC entity in the terminal configured by peering the PDCP PDU to the RLC entity of a specific base station (for example, the second base station). . Through this, the terminal may transmit only uplink data to the second base station.

In addition, after the UE submits the PDCP PDU to the RLC entity, the UE may further include performing a logical channel priority procedure in the MAC entity peered to the second base station. The logical channel priority procedure may perform a logical channel priority procedure for logical channels to carry uplink data through the second base station.

In addition, the terminal may perform an operation required to perform the present invention of each embodiment described above.

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

In a method for controlling uplink data transmission of a terminal, a first base station according to another embodiment of the present invention may include generating higher layer signaling and higher layer signaling including information for configuring a dual connection with the terminal. The method may include transmitting to a terminal and configuring a split radio bearer for the terminal.

Referring to FIG. 23, the first base station may generate higher layer signaling including information for configuring dual connectivity with the terminal (S2310). For example, higher layer signaling may further include index or segmentation information for identifying an uplink cell or uplink base station for transmitting uplink data to a particular base station (eg, a second base station). In addition, the higher layer signaling may include one or more pieces of information among the index, the identifier, and the distinguishing information of the above-described embodiments.

The first base station may transmit the generated higher layer signaling to the terminal (S2320). For example, higher layer signaling may include radio resource configuration information and may be transmitted in an RRC reconfiguration message.

The first base station may configure a dual connection with the second base station to the terminal, may configure a split radio bearer (S2330). For example, the first base station may configure a dual connection with the terminal, and may configure a split radio bearer and / or a dedicated radio bearer as shown in FIGS. 6 and 7. The UE configures a dual connection based on the information of the higher layer signaling received from the first base station, and can transmit uplink data for the split bearer only to a specific base station (for example, the second base station).

In addition to this, the base station may perform operations required to carry out the present invention of each of the above-described embodiments.

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

The terminal 2400 according to another embodiment of the present invention may include a receiver 2410 for receiving higher layer signaling including information for configuring a dual connection with the first base station and the second base station and based on the higher layer signaling. Form a dual connection with the first base station and the second base station, and the PDCP entity submits the PDCP PDUs for each of the one or more radio bearers to the configured RLC entity peered to a specific base station (e.g., the second base station) based on higher layer signaling. It may include a control unit 2420 to control to.

Referring to FIG. 24, a user terminal 2400 according to another embodiment includes a receiver 2410, a controller 2420, and a transmitter 2430.

The receiver 2410 may receive higher layer signaling, downlink control information, data, and a message from a base station through a corresponding channel. For example, higher layer signaling may include an index or segment for identifying an uplink cell or uplink base station for transmitting uplink data to a particular base station (eg, a second base station). That is, it may include one or more pieces of information of the index, the identifier, the identification information of each of the above-described embodiments. In addition, the higher layer signaling may include radio resource configuration information and may be an RRC reconfiguration message.

The control unit 2420 may be configured to deliver different uplink traffic paths and downlink traffic paths when a plurality of base stations form a dual connection to a terminal in a mobile communication network required to perform the above-described embodiments of the present invention. Control the overall operation of the terminal according. In addition, the controller 2420 may configure a radio bearer configured to be split into the first base station and the second base station. In addition, the controller 2420 may control the PDCP entity of the terminal to submit a PDCP PDU for each of one or more radio bearers to an RLC entity configured to be peered to a specific base station (eg, a second base station) based on higher layer signaling. have. For example, the one or more radio bearers may be radio bearers that are split and configured at the first base station and the second base station. That is, the controller 2420 may control one PDCP entity to submit the PDCP PDU to the RLC entity in the terminal configured to be peered to the RLC entity of a specific base station (for example, the second base station).

In addition, the controller 2420 may control to perform a logical channel priority procedure in the MAC entity peered to the second base station. For example, the control may be performed to perform a logical channel priority procedure for logical channels to transmit uplink data through the second base station.

The transmitter 2430 transmits uplink control information, data, and messages to the base station through the corresponding channel. In this case, the transmitter 2430 may transmit uplink data for the split bearer only to a specific base station (for example, the second base station).

25 is a diagram showing the configuration of a base station according to another embodiment of the present invention.

The first base station 2500 according to another embodiment of the present invention is a control unit 2510 for generating a higher layer signaling including information for configuring a dual connection to the terminal in controlling uplink data transmission of the terminal and Including a transmitter 2520 for transmitting higher layer signaling to the terminal, the controller 2510 may control to configure a split radio bearer for the terminal.

Referring to FIG. 25, a base station 2500 according to another embodiment includes a controller 2510, a transmitter 2520, and a receiver 2530.

The control unit 2510 is configured to configure the uplink traffic path and the downlink traffic path differently when a plurality of base stations form a dual connection to the terminal in the mobile communication network required to perform the above-described embodiments of the present invention. To control the overall operation of the base station.

In addition, the controller 2510 may generate higher layer signaling including information for configuring a dual connection with the terminal. For example, higher layer signaling may further include index or segmentation information for identifying an uplink cell or uplink base station for transmitting uplink data to a particular base station (eg, a second base station). In addition, the higher layer signaling may include one or more pieces of information among the index, the identifier, and the distinguishing information of the above-described embodiments. In addition, the controller 2510 may configure a split radio bearer in the second base station and the terminal. Alternatively, a dedicated wireless bearer and a split wireless bearer may be configured together.

The transmitter 2520 transmits the generated higher layer signaling to the terminal. For example, higher layer signaling may include radio resource configuration information and may be transmitted in an RRC reconfiguration message. In addition, the transmitter 2520 may transmit downlink data to the terminal.

The receiver 2530 is used to receive a signal, a message, and data necessary for carrying out the above-described present invention with the terminal. However, uplink data of the terminal may be transmitted through a specific base station (for example, the second base station) and transmitted to the first base station. When the specific base station is the first base station, uplink data of the terminal may be transmitted only to the first base station.

According to the present invention described above, there is an effect that the terminal can transmit the uplink data traffic through a specific base station in an environment in which a dual connection with a plurality of base stations. For example, uplink data may be transmitted through the terminal and the second base station with little path loss, thereby reducing power consumption and improving uplink data transmission speed of the terminal. In another example, uplink data may be transmitted through a first base station having a wide coverage, thereby improving mobility performance.

In addition, according to the present invention, an uplink buffer status report and a logical channel priority procedure may be performed only for a specific cell or a specific base station even under a dual connectivity structure.

Method of transmitting buffer status report of UE for uplink transmission

Hereinafter, a case in which the terminal transmits buffer status information for uplink transmission when communicating with a base station. A terminal according to another embodiment of the present invention configures a radio bearer with one or more base stations, and transmits buffer status information for uplink transmission. In addition, the first embodiment and the second embodiment to be described below mean each embodiment of the method for transmitting the buffer status report of the terminal for the uplink transmission of the present invention, the first embodiment of the present invention for the uplink transmission An embodiment different from the first embodiment and the second embodiment is meant.

26 is a diagram illustrating an example of a MAC configuration diagram of a conventional terminal.

Referring to FIG. 26, the MAC layer may perform various functions. For example, the MAC layer may perform mapping between logical channels and transport channels. In addition, the MAC layer may perform a function of multiplexing MAC Service Data Units (SDUs) into transport blocks (TBs) transmitted from one or different logical channels to transport channels of the physical layer. . In addition, the MAC layer may perform a function of de-multiplexing MAC Service Data Units (SDUs) from transport blocks (TBs) transmitted on physical layer transport channels from one or different logical channels. do. In addition, a function such as logical channel prioritization and error correction through a hybrid automatic repeat request (HARQ) may be performed. In addition, the MAC layer provides a data transfer service for logical channels. Each logical channel type may be defined according to what type of information is transmitted. In one MAC layer entity, one radio bearer is mapped to one logical channel. Hereinafter, a merging technique between base stations connected by non-ideal backhaul will be described with reference to the drawings.

27 and 28 are diagrams illustrating respective examples of a bearer split user plane structure.

Referring to FIGS. 27 and 28, even when there are non-ideal backhauls between base stations, radio resources of a plurality of base stations may be merged and used for bearer transmission. For efficient radio resource scheduling in a non-ideal backhaul environment, each base station needs to have an independent scheduler. For example, when using a first base station (macrocell base station or master base station or MeNB) and a second base station (small cell base station or secondary base station or SeNB) for one radio bearer transmission, RLC entity and MAC entity may be configured in each of the first base station and the second base station.

For example, referring to FIG. 27, a first base station has one PDCP entity, an RLC entity, and a MAC entity for a specific radio bearer in a bearer separation structure in which one radio bearer is divided into a second base station. The second base station may have an RLC entity and a MAC entity for the radio bearer. Hereinafter, the radio bearer provided through the RLC entity and the MAC entity to each of the first base station and the second base station as in the right radio bearer of FIG. 27 is referred to as a split radio bearer as shown in FIG. 6.

As another example, referring to FIG. 28, a bearer may have a first base station separated from an RLC entity. Even in this case, the first base station may have one PDCP entity, RLC entity, and MAC entity for a specific radio bearer. The second base station may have one MAC entity separately from the first base station in the bearer configured by bearer separation for the radio bearer. As another example, it may further have an RLC entity.

The buffer status report procedure is a procedure used to provide the serving cell base station with information about the amount of available data for transmission in terminal uplink (UL) buffers. The specific buffer status reporting procedure is described in Section 5.4.4 of 3GPP TS 36.321. The Buffer Status Report (BSR) should be triggered when the following events occur.

Uplink data is available for one logical channel belonging to one logical channel group (LCG) for transmission in a Radio Link Control (RLC) entity or a Packet Data Convergence Protocol (PDCP) entity. Lose. And the data belongs to a logical channel group belonging to any logical channel group and having a higher priority than the priority of the logical channels for the already available data, or among the logical channels belonging to one logical channel group. No data is available for anything. The buffer status report in this case is called "Regular BSR".

A buffer status report is called a "Padding BSR" when an uplink resource is allocated and the number of padding bits is equal to or greater than the size of the buffer status report MAC control element plus its subheader.

The buffer status report when the retransmission buffer status report timer (retxBSR-Timer) expires and the terminal has available data for transmission to any of the logical channels belonging to the logical channel group is also referred to as "Regular BSR".

-The buffer status report when the periodic buffer status report timer (periodicBSR-Timer) expires is called "Periodic BSR".

One MAC Protocol Data Unit (PDU) may include at most one MAC Buffer Status Report Control Element (BSR control element).

The UE should transmit at most one Regular / Periodic BSR within one Transmission Time Interval (TTI). If the UE is requested to transmit a plurality of MAC PDUs in one TTI, the UE may include a padding BSR to any of the MAC PDUs not including the Regular / Periodic BSR.

All BSRs sent in one TTI always indicate the buffer status after all MAC PDUs have been created for this TTI. Each logical channel group should report at most one buffer status value per TTI. This value must be reported in all buffer status reports (BSRs) that report the buffer status for this logical channel group.

The above-described data available for transmission will be described in more detail.

For the purpose of reporting buffer status of the MAC layer, the UE should consider the following as the amount of data available in the RLC layer.

Consider RLC SDUs, or segments, not yet included in the RLC data PDU.

Consider pending RLC data PDUs (RLC AM) for retransmission.

On the other hand, for the purpose of reporting the buffer status of the MAC layer, the UE should consider PDCP control PDUs and the following as the amount of data available in the PDCP layer.

If there is an SDU that has not yet been processed by PDCP for an SDU for which a PDU has not been submitted to a lower layer, the SDU itself is considered. Also, if there is an SDU processed by PDCP for an SDU for which a PDU is not submitted to a lower layer, the PDU is considered.

Except for SDUs that indicate successful delivery by the PDCP Status Report, starting with the first SDU for delivery of those PDUs not identified by the lower layer, and for those PDUs that have been submitted to the lower layer only prior to PDCP reset If there is an SDU for the SDU that has not yet been processed by the PDCP, then consider the SDU itself. Also, if there is an SDU processed by PDCP, consider the PDU.

Among the bearers shown in FIG. 27 or 28, a specific bearer, such as a right bearer (split bearer), terminates the S1-U interface at the first base station for one bearer and uses a bearer split user plane structure. To be processed through the first base station and the second base station. In addition, bearer separated bearers may have schedulers in a plurality of base stations for one bearer transmission.

As described above, the amount of available data provided through the existing buffer state reporting for uplink transmission is calculated by summing the amount of available data of the RLC layer and the PDCP layer.

Therefore, when configured to process through the first base station and the second base station by using a user plane structure of the bearer split (bearer split) in the first base station for one bearer, such as a specific bearer separated bearer in Figure 27 or 28 In case of a buffer status report of a terminal, a problem may occur. For example, the amount of available data of the PDCP layer may be calculated in duplicate when calculating the uplink buffer through the first base station and when calculating the uplink buffer through the second base station. Therefore, when performing uplink scheduling at the first base station or uplink scheduling at the second base station, excessive scheduling may occur compared to the total uplink buffer amount of the terminal. That is, since the information on the amount of available data included in one PDCP entity is included in a plurality of buffer status reports, the information on the amount of actual available data may not be correctly transmitted to the base station.

In summary, even if different base stations are connected by non-ideal backhaul as described above, data may be transmitted by merging radio resources through a plurality of base stations. In addition, separate schedulers are required for individual base stations for one bearer transmission.

In this case, when the first base station and the second base station are configured to be processed using a bearer split user plane structure for a specific bearer, the terminal may calculate an uplink buffer through the first base station. When calculating the uplink buffer through the second base station and when the amount of available data of the PDCP layer may overlap. Therefore, a problem may occur that causes waste of radio resources by inducing scheduling that exceeds the total uplink buffer amount of the terminal.

The present invention devised to solve such a problem is a method that can be accurate buffer status report even when different base stations are configured to transmit data by merging radio resources through a separate scheduler for a specific bearer separated bearer. to provide. For example, it is possible to provide a method for efficiently using radio resources by allowing a terminal to report the amount of available data corresponding to the total amount of uplink buffers for logical channels of a corresponding radio bearer to individual base stations. The purpose.

FIG. 29 is an exemplary diagram of an available data amount of a logical channel mapped to a split bearer in a terminal for explaining the present invention.

As illustrated in FIG. 29, the terminal has an RLC entity (RLC-M) in the terminal peered to the RLC entity of the master base station for the split bearer and an RLC entity (RLC-S) in the terminal peered to the RLC entity of the secondary base station. The terminal also has an in-terminal MAC entity (MAC-M) peered to the MAC entity of the master base station and the in-terminal MAC entity (MAC-S) peered to the MAC entity of the secondary base station.

 Referring to FIG. 29, according to the conventional method of calculating the amount of available data, a logical channel mapped to a MAC layer of a terminal or a MAC entity of a terminal or a MAC entity of a terminal is calculated by summing up the available data amounts of a higher layer, thereby calculating BSR. You can ask too much. For example, the terminal may transmit a buffer status report to each base station. In this case, the MAC entity (MAC-M: MAC-Master) peered to the MAC entity of the master base station is in the buffer status report sent to the first base station to the available data amount 500 of the PDCP entity and the first base station RLC entity The available data amount 200 of the peered RLC entity (RLC-M: RLC-Master) may include 700 available data amount information, which is added up. In the same manner, the MAC entity (MAC-S: MAC-Secondary) peered to the MAC entity of the secondary base station may use the amount of data 500 and RLC (RLC-S :) of the PDCP entity in the buffer status report transmitted to the second base station. The available data amount 100 of the RLC-Secondary layer may include 600 available data amount information, which is added up. Accordingly, there is a problem in that the amount of available data of 500 is excessively transmitted compared to 800 (500 + 200 + 100), which is the total amount of available data included in each layer of the terminal.

In order to solve such a problem, the present invention provides an efficient buffer status report method based on the embodiments described below. In the following description, a logical channel mapped to a split bearer is mainly described as an example for convenience of explanation, and the same method may be applied to a logical channel group as well as a logical channel.

In addition, the PDCP buffer status information means the amount of available data of the PDCP layer.

First embodiment: A method of transmitting PDCP buffer status information of a logical channel mapped to a split bearer separately from a buffer status report.

30 is a diagram illustrating an example of a configuration of a MAC PDU (Protocol Data Unit) according to an embodiment of the present invention.

Referring to FIG. 30, a MAC PDU includes one MAC header, zero or more MAC Service Data Units (SDUs), zero or more MAC control elements, and optionally includes padding. do.

The MAC PDU header consists of one or more MAC PDU subheaders 3001. Each subheader 3001 corresponds to one MAC SDU, one MAC control element or padding (A MAC PDU header consists of one or more MAC PDU subheaders; each subheader corresponds to either a MAC SDU, a MAC control element or padding).

The Logical Channel ID (LCID) field included in the MAC header identifies the logical channel instance of the corresponding MAC SDU or the type of the corresponding MAC control element or padding.

A terminal according to the first embodiment of the present invention may transmit PDCP buffer status information for a logical channel or a logical channel group mapped to a split bearer differently from a buffer status report to a base station.

For example, in the case of a split bearer in which one or more bearers are separated, such as a specific bearer illustrated in FIG. 27 or 28, a PDCP for a logical channel (or a logical channel group including logical channels) mapped to the split bearer The buffer status information including the buffer size information may be separately transmitted to the base station. For example, the PDCP buffer status information may be delivered through a MAC control element. For this purpose, a separate Logical Channel ID (LCID) value may be defined. The separate LCID value may be defined as exemplarily shown in FIG. 31.

31 is a diagram illustrating an example of an LCID value for UL-SCH according to another embodiment of the present invention.

As shown in FIG. 31, the terminal may transmit PDCP buffer status information to the first base station and / or the second base station. Accordingly, the PDCP buffer status information is duplicated and transmitted separately without being included in the buffer status report, thereby delivering information on the exact amount of available data.

For example, the PDCP buffer status information may be included in the MAC control element and transmitted to the first base station and / or the second base station. Specifically, the format of the PDCP buffer status information MAC control elements may be classified into a PDCP Short BSR format, a PDCP Truncated BSR, and a PDCP Long BSR format. That is, the PDCP buffer status report can be transmitted using the BSR format, and can be distinguished from the existing BSR using a specific index.

32 is a diagram illustrating an example of each PDCP BSR MAC control element format.

Referring to FIG. 32, the terminal may transmit PDCP buffer status information to the first base station and / or the second base station. In this case, the terminal may transmit the PDCP buffer status information using the BSR format. In order to distinguish it from the existing BSR, a BSR transmitted including only PDCP buffer status information may be divided into separate indexes as shown in FIG. 31.

More specifically, for example, the PDCP Short BSR / PDCP Truncated BSR format 3200 includes one Logical Channel Group ID (LCG ID) field and one corresponding buffer size field as shown in FIG. 32. The logical channel group ID field is a field for identifying a logical channel group for which buffer status information is to be reported, and may be configured in 2-bit length.

32, the PDCP Long BSR format may include four buffer size fields 3210, 3220, and 3230 corresponding to LCG IDs # 0 to # 3. Although FIG. 32 illustrates that the buffer size is composed of six bits, the PDCP BSR may be designed with a value smaller than six bits by applying a level different from the existing BSR. For example, it may be designed with three bits that can have eight indices, four bits that can have sixteen indices, five bits that can have thirty-two indexes, and the like.

As an example, the buffer size field of FIG. 32 is the total amount of data available in the PDCP layer for a logical channel (or logical channel group containing bearer split logical channels) mapped to split bearers through a first base station and a second base station. It may include information about.

In this case, the base station receiving the PDCP buffer status information may estimate the amount of available data of the PDCP layer that can be processed through each base station. As an example, the base station multiplies each base station by multiplying the distribution ratio from the PDCP layer (or entity) in the terminal to the RLC layer (or entity) peered to the first base station and the RLC layer (or entity) peered to the second base station. It is possible to calculate the amount of available data of the PDCP layer that can be processed through. That is, the total available data amount of the PDCP layer can be distributed according to the distribution ratio to check buffer state information of the PDCP layer to be processed at each base station. Each of the first base station and the second base station has a PDCP buffer state to be processed in each base station described above in an existing buffer status report (short BSR or Truncated BSR or Long BSR) calculated by summing the available data amounts of the RLC layer and the PDCP layer. By subtracting the value of the information, the amount of available data of the RLC layer of each base station can be confirmed. Accordingly, each base station can determine the amount of available data to be transmitted uplink through each base station by adding the available data amount of the RLC layer for each base station and the available data amount of the distributed PDCP layer according to the distribution ratio. Each base station may calculate an actual uplink radio resource (uplink grant) to be scheduled through each base station in the above-described manner and allocate uplink radio resources that should be provided through each base station.

The distribution ratio from the PDCP layer (or entity) in the terminal to the RLC layer (or entity) peered to the first base station and the RLC layer (or entity) peered to the second base station is static between the first base station and the second base station. Can be preset. For example, the first base station may be configured when configuring a dual connection for a split bearer in the terminal through signaling with the second base station. Or, it may be dynamically changed according to radio quality and exchanged periodically or according to a specific event through signaling through an interface between the first base station and the second base station. When the distribution ratio is dynamically calculated, one or more information of a calculation cycle for calculating the distribution ratio, a change cycle for changing the distribution ratio, and a trigger condition for interface signaling may be exchanged together. When the distribution ratio from the PDCP layer (or entity) in the terminal to the RLC layer (or entity) peered to the first base station and the RLC layer (or entity) peered to the second base station is dynamically changed, the first base station or the first 2 The base station may provide this information to the terminal through RRC signaling or MAC signaling.

As another example, the buffer size field of FIG. 32 calculates the total amount of data available in the PDCP layer for the logical channel (or logical channel group including bearer split logical channels) of the split bearer over the first base station and the second base station. It may include ratio information for.

In this case, the base station receiving the PDCP buffer status information determines the total amount of available data of the PDCP layer from the existing BSR (short BSR or Truncated BSR or Long BSR), which is calculated by summing the available data amounts of the RLC layer and the PDCP layer. The total amount of available data of the PDCP layer may be calculated by multiplying the ratio to calculate. Thereafter, the base station subtracts the available data amount of the RCP layer from the existing BSR (short BSR or Truncated BSR or Long BSR) calculated by summing the available data amounts of the RLC layer and the PDCP layer. Able to know. Therefore, by adding the available data amount of the RLC layer and the available data amount of the PDCP layer to be processed through each base station, it is possible to calculate the actual uplink radio resource (uplink grant) to be scheduled through each base station. Each base station that calculates an uplink radio resource may allocate an uplink radio resource to be provided through each base station. The distribution ratio from the PDCP layer (or entity) in the terminal to the RLC layer (or entity) peered to the first base station and the RLC layer (or entity) peered to the second base station is static between the first base station and the second base station. Can be preset. For example, the first base station may be configured when configuring a dual connection for a split bearer in the terminal through signaling with the second base station. Or, it may be dynamically changed according to radio quality and exchanged periodically or according to a specific event through signaling through an interface between the first base station and the second base station. When the distribution ratio is dynamically calculated, one or more information of a calculation cycle for calculating the distribution ratio, a change cycle for changing the distribution ratio, and a trigger condition for interface signaling may be exchanged together. When the distribution ratio from the PDCP layer (or entity) in the terminal to the RLC layer (or entity) peered to the first base station and the RLC layer (or entity) peered to the second base station is dynamically changed, the first base station or the first 2 The base station may provide this information to the terminal through RRC signaling or MAC signaling.

As described above, in the first embodiment, the UE may transmit PDCP buffer status information related to the amount of available data of the PDCP layer separately from the existing BSR.

Second embodiment: A method for a terminal to calculate and transmit available data for each base station according to a distribution ratio.

When one or more bearers, such as the specific bearer illustrated in FIG. 27 or 28, are configured as separate bearers, the amount of data available for the logical channel (or logical channel group) mapped to the aforementioned split bearer is calculated by classifying the base stations. Reporting can be made through existing BSR (short BSR or Truncated BSR or Long BSR) MAC CE.

To this end, the UE uses a bearer split user plane structure in a PDCP layer for a logical channel (or logical channel group) mapped to a split bearer configured to process data through a first base station and a second base station. When calculating the available data amount, the available data amount of the existing PDCP layer can be calculated in consideration of the distribution ratio to individual base stations.

For example, the terminal may use a bearer split user plane structure to map a logical channel (or logic) to a split bearer configured to process data through the first base station and the second base station (or through one or more base stations). Channel state) can calculate the buffer state information (available data amount) of the PDCP layer for each base station (or for each cell group) in proportion to the uplink grant information received in the corresponding TTI for each base station. Alternatively, the terminal may calculate buffer state information (available data amount) of the PDCP layer for each base station (or for each cell group) based on an uplink grant average during a previous or recent TTI multiple period. That is, each base station is multiplied by the ratio of the available data of the PDCP layer for the corresponding logical channel by the ratio of the uplink grant (or the average of the uplink grants during the previous (most recent) TTI multiple times) to the corresponding TTI received for each base station. Buffer status information of the star (or cell group) PDCP layer may be calculated. For example, when the first base station uplink grant is a and the second base station uplink grant is b, the uplink grant ratio a / (a + b) is multiplied by the total amount of available data in the PDCP layer to give the first base station. Buffer status information of the PDCP layer may be calculated. Alternatively, in the above-described method for calculating buffer status information of each base station (or cell group) PDCP layer, the downlink allocation may be used in place of the uplink grant or the uplink grant and the downlink allocation may be added together. have. To this end, each base station (or cell group) PDCP is included in the RRC message in the logical channel configuration information included in the radio resource configuration-only information or the radio resource configuration-only information or the MAC-MainConfig configuration information included in the radio resource configuration-only information. It may include TTI period information for calculating the available data amount of the layer and / or information for indicating the same. Alternatively, the above-described information for calculating the amount of available data of the PDCP layer in the terminal may be preset.

As another example, the terminal may use a bearer split user plane structure to map a logical channel (or logic) to a split bearer configured to process data through the first base station and the second base station (or through one or more base stations). Channel status) can calculate buffer status information (available data amount) for each base station of the PDCP layer in proportion to the uplink grant during periodicBSR-Timer included in the MAC-MainConfig information element for each base station. have. Alternatively, the terminal may calculate buffer state information (available data amount) for each base station (or cell group) of the PDCP layer in proportion to the uplink grant during the retxBSR-Timer included in the MAC-MainConfig information element. Alternatively, the terminal receives new information (eg, a calculation cycle) necessary for calculating a ratio on the RRC message and is proportional to each base station (or cell group) of the PDCP layer in proportion to an uplink grant calculated according to the corresponding information. Buffer status information (available data amount) can be calculated. That is, the available amount of data of the PDCP layer for the corresponding logical channel is multiplied by the uplink grant rate during periodicBSR-Timer or retxBSR-Timer for each base station to enable the use of the PDCP layer for each base station (or cell group). The amount of data can be calculated. Specifically, as an example of the calculation method, when the first base station uplink grant is a and the second base station uplink grant is b for the above-described period, the ratio of a / (a + b) is fully available to the PDCP layer. The amount of available data of the PDCP layer of the first base station may be calculated by multiplying the amount of data. Alternatively, the downlink allocation may be used in place of the above-mentioned uplink grant, or the uplink grant and the downlink allocation may be combined. To this end, each base station (per cell group) PDCP layer is included in the logical channel configuration information included in the radio resource configuration-only information or the radio resource configuration-only information or the MAC-MainConfig configuration information included in the radio resource configuration-only information on the RRC message. May include periodic information for calculating the amount of available data and / or information for indicating the amount of available data. Alternatively, the above-described information for calculating the amount of available data of the PDCP layer in the terminal may be preset.

The above-described MAC-MainConfig information element for each base station may include individual configuration parameters for the MAC entity for each base station or each cell group when dual connectivity is configured for the terminal. For example, the secondary base station MAC-MainConfig (MAC-MainConfigSeNB or MAC-MainConfigSCG) is a buffer state independent of the buffer status report timers (eg periodicBSR-Timer and / or retxBSR-Timer) contained within the master base station MAC-MainConfig. May include report timers.

As another example, the terminal may be configured to process a logical channel (or mapped to a split bearer configured to process data through a first base station and a second base station (or through one or more base stations) using a bearer split user plane structure. Buffer status information of PDCP layer by each base station (or cell group) by equally allocating available data amount of PDCP layer for existing logical channel for each base station (or cell group) (Amount of available data) can be calculated. To this end, each base station (or cell group) PDCP is included in the RRC message in the logical channel configuration information included in the radio resource configuration-only information or the radio resource configuration-only information or the MAC-MainConfig configuration information included in the radio resource configuration-only information. It may also include information for calculating the amount of available data of the layer and / or information for indicating it. Alternatively, the above-described information for calculating the amount of available data of the PDCP layer in the terminal may be preset.

As another example, the terminal may be configured to process a logical channel (or mapped to a split bearer configured to process data through a first base station and a second base station (or through one or more base stations) using a bearer split user plane structure. Calculate PDCP buffer status information (available data amount) for each base station (or cell group) based on a ratio calculated based on radio quality status or RRM measurement information between a terminal and each base station for a logical channel group). can do. That is, the amount of available data of each base station (or cell group) PDCP layer can be calculated by allocating the amount of available data of the PDCP layer for the corresponding logical channel in proportion to or inversely proportional to the radio quality state or RRM measurement information. have. To this end, each base station (or cell group) PDCP is included in the RRC message in the logical channel configuration information included in the radio resource configuration-only information or the radio resource configuration-only information or the MAC-MainConfig configuration information included in the radio resource configuration-only information. It may include one or more of information for calculating the amount of available data of the layer, measurement period, measurement event, information for displaying it. Alternatively, the above-described information may be preset in the terminal.

As another example, the terminal may use a bearer split user plane structure to map a logical channel (or to a split bearer configured to process data through the first base station and the second base station (or through one or more base stations). Logical channel group) may be calculated based on available data amount information of the RLC layer peered to the terminal and each base station. That is, buffer status information of the PDCP layer for each base station is allocated by allocating the available data amount of the PDCP layer for the corresponding logical channel in proportion to or inversely proportional to the available data amount information of the RLC layer peered to each of the first base station and the second base station. (Amount of data available) can also be calculated. To this end, each base station (or cell group) PDCP is included in the RRC message in the logical channel configuration information included in the radio resource configuration-only information or the radio resource configuration-only information or the MAC-MainConfig configuration information included in the radio resource configuration-only information. It may also include information for calculating the amount of available data of the layer and / or information for indicating it. Alternatively, the above-described information for calculating the amount of available data of the PDCP layer in the terminal may be preset.

As another example, the terminal may be configured to process a logical channel (or mapped to a split bearer configured to process data through a first base station and a second base station (or through one or more base stations) using a bearer split user plane structure. PDCP layer for each base station by receiving ratio information for distributing available data amount of PDCP layer or method information for distributing for each base station (or for each cell group) The buffer status information (available data amount) of can be calculated. In more detail, for example, the terminal may receive the aforementioned ratio information or distribution method information through a first base station (master base station) in which an RRC connection is established. Alternatively, the terminal may receive the aforementioned ratio information or distribution method information through a second base station (secondary base station) confirmed by the first base station (master base station) in which the RRC connection is established. Alternatively, the terminal may receive the aforementioned ratio information or distribution method information through the first base station, and the corresponding information may be transmitted by the second base station supporting the first base station through the first base station. To this end, each base station (or cell group) PDCP is included in the RRC message in the logical channel configuration information included in the radio resource configuration-only information or the radio resource configuration-only information or the MAC-MainConfig configuration information included in the radio resource configuration-only information. It may also include ratio information for calculating the amount of available data of the layer and / or information for indicating it. Alternatively, the above-described information for calculating the amount of available data of the PDCP layer in the terminal may be preset. Alternatively, the aforementioned ratio information may be received with a new MAC control element defined. For example, the newly defined MAC control element may be a first base station established through an RRC connection (or a first base station confirmed by a second base station) or a first base station confirmed by a first base station with an RRC connection established. The terminal may be transmitted through a second base station supporting the base station or through a second base station supporting the first base station.

The terminal may transmit / submit data (PDU) from the PDCP layer in the terminal to the RLC entity in the terminal mapped to the RLC entity of each base station based on the ratio information received from the base station.

By the above-described methods, the terminal may calculate PDCP buffer status information for each base station. The terminal may add the calculated PDCP buffer status information for each base station (or cell group) with the available data amount of the RLC layer peered to each base station and transmit a buffer status report to each base station. That is, in the second embodiment, the PDCP buffer status report is included in the existing buffer status report (BSR) and not transmitted separately. However, PDCP buffer status information included in the buffer status report transmitted for each base station is information calculated by dividing each base station by each method described above. The MAC entity for each base station (or for each cell group) in the terminal may transmit a buffer status report to each base station.

Therefore, each base station receives the amount of available data to be processed through each base station through the BSR, which can efficiently allocate uplink radio resources according to the buffer size information of the received BSR, and buffer status information of the PDCP layer. It can solve the problem of duplicate transmission of.

Third embodiment: A method of reporting different data calculation methods available for each base station.

When one or more bearers, such as the specific bearer illustrated in FIG. 27 or 28, are configured as separate bearers, a method of calculating the amount of available data for a logical channel (or logical channel group) mapped to the aforementioned split bearer differs for each base station. It can be reported through the existing BSR (short BSR or Truncated BSR or Long BSR) MAC CE.

For example, the terminal may be configured to include a first logical channel (or logical channel group) mapped to a split bearer configured to process data through a first base station and a second base station by using a bearer split user plane structure. The amount of available data through the base station (or the master cell group or the first base station MAC entity or the first base station MAC entity in the terminal peered to the first base station MAC entity) may use the existing available data amount calculation method. That is, the UE may perform BSR reporting by summing the available data amount of the PDCP layer and the available data amount of the RLC layer for the first base station with the available data amount through the first base station. have. And the terminal is an RLC layer for the second base station in the terminal with the amount of available data through the second base station (or the secondary cell group or the second base station MAC entity or the second base station MAC entity in the terminal peered to the second base station MAC entity). The BSR reporting can be performed using the available data amount of. That is, the buffer status report transmitted to the second base station may not include the buffer status information (available data amount) of the PDCP layer. The UE determines this according to radio conditions (quality) or adds the available data amount of the PDCP layer for the logical channel mapped to the corresponding split bearer through the first base station where the RRC connection is established to the amount of available data through the first base station. Information for display may be received and configured (processed). For this purpose, the RRC message or the MAC CE may be used for the message transmitted from the base station to the terminal. If the terminal is configured to include the amount of available data of the PDCP layer for the split bearer in the amount of available data through the first base station, the terminal includes the PDCP PDU for the split bearer in the terminal peered to the first base station RLC entity. It can only be submitted as an RLC entity. That is, the uplink data for the bearer may be transmitted only through the first base station.

As another example, the second terminal may be configured with respect to a logical channel (or logical channel group) mapped to a split bearer configured to process data through a first base station and a second base station by using a bearer split user plane structure. The amount of available data through the base station (or the secondary cell group or the second base station MAC entity or the second base station MAC entity in the terminal peered to the second base station MAC entity) may use the existing available data amount calculation method. That is, the UE may perform BSR reporting by summing the available data amount of the PDCP layer and the available data amount of the RLC layer for the second base station with the available data amount through the second base station. have. The terminal may perform BSR reporting using the available data amount of the RLC layer for the first base station in the terminal as the amount of available data through the first base station. That is, the buffer status report transmitted to the first base station may not include the buffer status information (available data amount) of the PDCP layer. The UE determines this according to the radio condition (quality) or receives the confirmation by the first base station through which the RRC connection is established (or through the first base station by confirmation of the second base station) or by the first base station through which the RRC connection is established. The amount of available data of the PDCP layer for the corresponding logical channel is added to the amount of available data through the second base station through a second base station supporting one base station or a second base station supporting a first base station through the first base station. Information for display may be received and configured (processed). To this end, the message transmitted from the base station to the terminal may include new information in the RRC message or a new MAC CE may be defined and used. When the terminal is configured to include the amount of available data of the PDCP layer for the split bearer in the amount of available data through the second base station, the terminal includes the PDCP PDU for the split bearer in the terminal peered to the second base station RLC entity. You can only submit as an RLC entity. That is, the uplink data for the bearer may be transmitted only through the second base station.

As another example, the terminal may be configured for a logical channel mapped to a split bearer configured to process data through a first base station and a second base station (or through one or more base stations) using a bearer split user plane structure. A base station to first allocate the available data amount of the PDCP layer may be selected based on radio quality status or RRM measurement information between the terminal and each base station. To this end, the amount of available data of the PDCP layer is first assigned to the RRC message to the logical channel configuration information included in the radio resource configuration-only information, the radio resource configuration-only information, or the MAC-MainConfig configuration information included in the radio resource configuration-only information. It may include one or more pieces of information of the base station information, information for selecting the base station to be assigned first, a measurement period, a measurement event and information for displaying the same. Alternatively, the above-described information may be preset in the terminal.

Thus, each base station receives the amount of available data to be processed through each base station through the BSR, so that each base station can efficiently allocate uplink radio resources according to the requested buffer size. That is, by including the PDCP buffer status information only in the buffer status report transmitted to any one of the base stations, it is possible to solve the problem that the PDCP buffer status information is repeatedly transmitted to the base station.

As described above, according to the present invention, even when different base stations for a specific bearer are configured to transmit data by merging radio resources through separate schedulers, each base station may allocate radio resources only for the amount of available data actually needed. Thus, there is an effect of efficiently allocating radio resources.

Hereinafter, the operation of the terminal and the base station in which all the above-described embodiments can be performed will be described once again with reference to the drawings.

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

In a method for transmitting buffer status information, a terminal according to an embodiment of the present invention is configured to dually connect one or more logical channels or logical channel groups mapped to a split bearer by higher layer signaling with a first base station and a second base station. And configuring the PDCP layer available data amount of one or more logical channels or logical channel groups to the first base station or the second base station.

Referring to FIG. 33, the terminal may configure dual connectivity for at least one logical channel or logical channel group mapped to the split base bearer with the first base station and the second base station according to higher layer signaling (S3310). ). That is, the terminal may configure a bearer with at least one base station as illustrated in FIGS. 27 and 28, and the at least one bearer may be configured separately from the first base station and the second base station.

The UE may transmit the PDCP layer available data amount of the logical channel mapped to the above-described separated bearer or logical channel group including the corresponding logical channel to the first base station or the second base station (S3320).

In transmitting the PDCP layer available data amount, the terminal may include the existing buffer status report in the above-described embodiment and transmit the same. When the transmission is included in the existing buffer status report, the transmission may be included only in the buffer status report transmitted to any one base station as in the third embodiment.

In addition, in configuring a logical channel or a logical channel group in a MAC object, the terminal may include a buffer status report (BSR) timer for each base station or cell group according to higher layer signaling.

For example, the PDCP layer available data amount may be included in only one of the buffer status report transmitted to the first base station or the buffer status report transmitted to the second base station according to higher layer signaling.

As such, the terminal may transmit the PDCP layer available data amount so as not to overlap with the first base station or the second base station, and the first base station and the second base station can efficiently allocate radio resources.

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

In a method for receiving buffer status information, a first base station according to another embodiment of the present invention comprises: configuring a dual connection between a second base station and a terminal for at least one logical channel or logical channel group mapped to a split bearer; Receiving a layer available data amount from the terminal.

Referring to FIG. 34, the first base station may configure dual connectivity with the terminal (S3410). That is, the first base station may configure a dual connection with the terminal along with the second base station for one or more logical channels or logical channel groups mapped to the split bearer. For example, as illustrated in FIGS. 27 and 28, the first base station may separate one or more bearers to configure dual connectivity with the second base station.

The first base station may receive the PDCP layer available data amount from the terminal (S3420). The first base station allocates an uplink radio resource to the terminal based on the received buffer status report. In receiving the PDCP layer available data amount, the first base station may receive the PDB by including it in an existing buffer status report according to the above-described embodiment. When received in the existing buffer status report, it is included in the buffer status report transmitted to the first base station and not included in the buffer status report transmitted to the second base station as in the third embodiment.

For example, the available data amount of PDCP may be included in only the buffer status report received by the first base station according to higher layer signaling. That is, the buffer status report transmitted to the second base station may not include information on the amount of available data of the PDCP layer.

In the above manner, the first base station may calculate a radio resource to be allocated to the terminal based on the existing buffer status report. As a specific calculation method, the method described in each embodiment described above may be used.

The first base station may allocate the calculated radio resource to the terminal and receive an uplink from the terminal.

In the case of the second base station, the same operation as that of the first base station may be performed. However, when the PDCP layer available data amount is included only in the buffer status report transmitted to the first base station, the second base station may receive a buffer status report in which the PDCP layer available data amount is excluded.

A configuration of a terminal and a base station in which each embodiment of the present invention can be performed will be described with reference to the drawings.

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

The terminal for transmitting the buffer status information according to another embodiment of the present invention, the control unit 3520 configured to dually connect one or more logical channels or logical channel groups mapped to the split bearer with the first base station and the second base station and The transmitter 3530 may transmit a PDCP layer available data amount of one or more logical channels or logical channel groups mapped to the split bearer to the first base station or the second base station.

Referring to FIG. 35, a user terminal 3500 according to another embodiment of the present invention includes a receiver 3510, a controller 3520, and a transmitter 3530.

The receiver 3510 receives downlink control information, data, and a message from a base station through a corresponding channel. That is, downlink information such as uplink radio resource allocation information can be received.

The controller 3520 controls the operation of the terminal required to form a dual connection with the first base station and the second base station required to carry out the above-described present invention. In addition, the controller 3520 may control the operation of the terminal according to the distribution or division and transmission of the amount of PDCP layer available data of the logical channel or logical channel group configured by bearer separation according to each embodiment described above.

In addition, the transmitter 3530 transmits uplink control information, data, and a message through a corresponding channel.

In addition, the terminal may perform all operations necessary for performing each of the above-described embodiments.

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

The first base station receiving the buffer status information according to another embodiment of the present invention, the control unit 3610 configures a dual connection between the second base station and the terminal for one or more logical channels or logical channel groups mapped to the split bearer And a receiver 3630 that receives the amount of PDCP layer available data from the terminal.

Referring to FIG. 36, the base station 3600 according to another embodiment of the present invention includes a controller 3610, a transmitter 3620, and a receiver 3630.

The controller 3610 may control an operation of the base station required to configure a dual connection with the terminal together with the second base station. In addition, the controller 3610 may allocate an uplink radio resource based on a buffer status report received from the terminal according to each embodiment.

The transmitter 3620 may transmit downlink control information and a message to the terminal.

The receiver 3630 may receive a PDCP layer available data amount from the terminal. In detail, the receiver 3630 may receive the PDCP layer available data amount in the buffer status report according to the above-described embodiment of the present invention. In addition, the receiver 3630 may receive an uplink signal, a message, or data necessary for carrying out the present invention.

In addition, the base station may perform all the operations necessary for performing each of the above-described embodiments.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application is filed with Korea Patent Application No. 10-2013-0114769 filed on September 26, 2013, and Korea Patent Application No. 10-2013-0144656 filed on November 26, 2013, and March 2014. 119 (a) (35 USC §) of the US Patent Act No. 10-2014-0030422 filed with Korea on 14 and patent application No. 10-2014-0043696 filed with Korea on April 11, 2014 Priority is claimed under 119 (a)), the contents of which are hereby incorporated by reference in their entirety. In addition, if this patent application claims priority for the same reason for countries other than the United States, all its contents are incorporated into this patent application by reference.

Claims (17)

In the method for the terminal to transmit the uplink data, Receiving higher layer signaling including information for establishing a dual connection with the first base station and the second base station; Configuring dual connectivity with the first base station and the second base station based on the higher layer signaling; And And a PDCP entity submitting PDCP PDUs for each of one or more radio bearers to an RLC entity peered to the first base station or the second base station based on the higher layer signaling. The method of claim 1, The one or more radio bearers, And a radio bearer configured to be split into the first base station and the second base station. The method of claim 1, The higher layer signaling, And index or identification information for identifying an uplink cell or uplink base station for transmitting the uplink data to the first base station or the second base station. The method of claim 3, wherein Index or division information for transmitting the uplink data to the first base station or the second base station, And a value for configuring to transmit the uplink data through the first base station and a value for configuring to transmit the uplink data through the second base station. The method of claim 1, After submitting to the RLC entity, And performing a logical channel priority procedure at the MAC entity peered to the first base station or the second base station. In the first base station to control the uplink data transmission of the terminal, Generating higher layer signaling including information for forming a dual connection with the terminal; Transmitting the higher layer signaling to the terminal; And And configuring a split radio bearer for the terminal. The method of claim 6, The higher layer signaling, And index or identification information for identifying an uplink cell or uplink base station for transmitting the uplink data to the first base station or the second base station. The method of claim 7, wherein Index or division information for transmitting the uplink data to the first base station or the second base station, And a value for configuring to transmit the uplink data through the first base station and a value for configuring to transmit the uplink data through the second base station. In the terminal for transmitting uplink data, A receiver configured to receive higher layer signaling including information for configuring a dual connection with the first base station and the second base station; And Configure dual connectivity with the first base station and the second base station based on the higher layer signaling, And a controller for controlling a PDCP entity to submit a PDCP PDU for each of at least one radio bearer to an RLC entity peered to the first base station or the second base station based on the higher layer signaling. In the first base station for controlling the uplink data transmission of the terminal, A controller configured to generate higher layer signaling including information for configuring a dual connection with the terminal; And Includes a transmitter for transmitting the higher layer signaling to the terminal, The control unit is a base station for controlling to configure a split radio bearer (split radio bearer) for the terminal. In the method for the terminal to transmit the buffer status information, Configuring at least one logical channel or logical channel group mapped to the split bearer based on higher layer signaling to be dually connected with the first base station and the second base station; And Transmitting a data available for transmission in a PDCP layer of the at least one logical channel or logical channel group to the first base station or the second base station. The method of claim 11, Configuring a logical channel or logical channel group mapped to a split bearer based on the higher layer signaling, And a buffer status report (BSR) timer for each base station or cell group. The method of claim 11, The PDCP layer available data amount is And a buffer status report of only one of a buffer status report transmitted to the first base station and a buffer status report transmitted to the second base station based on the higher layer signaling. In the first base station to receive the buffer status information, Configuring a dual connection between the second base station and the terminal for at least one logical channel or logical channel group mapped to the split bearer based on higher layer signaling; And Receiving a PDCP layer available data amount from the terminal. The method of claim 14, The PDCP layer available data amount is Included only in the buffer status report received by the first base station or based on the higher layer signaling, or not included in the buffer status report received by the second base station. How to feature. In the terminal for transmitting the buffer status information, A controller configured to dually connect one or more logical channels or logical channel groups mapped to the split bearer based on higher layer signaling with the first base station and the second base station; And And a transmitter for transmitting the PDCP layer available data amount of the at least one logical channel or logical channel group to the first base station or the second base station. A first base station for receiving buffer status information, A control unit for configuring dual connectivity between the second base station and the terminal for at least one logical channel or logical channel group mapped to the split bearer based on higher layer signaling; And Includes a receiver including a receiver for receiving the PDCP layer available data amount from the terminal, The PDCP layer available data amount is included only in the buffer status report received by the first base station or in the buffer status report received by the second base station according to the higher layer signaling. It is not included in the base station.

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