JP2019036874A - base station - Google Patents

Abstract

To realize early transmission of redistributed transmission target data in distributed communication.SOLUTION: A base station according to one embodiment of the present invention includes a wireless communication unit that performs wireless communication with a user device and a storage unit that stores transmission target data to be transmitted to the user device for which dual connectivity has been set, and the wireless communication unit transmits, to the user device, second transmission target data redistributed from another base station with priority over first transmission target data already stored in the storage unit.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a wireless communication system.

  At present, a new wireless communication system called NR (New Radio Access Technology) is being developed as a successor of LTE (Long Term Evolution) system and LTE-Advanced system in 3GPP (Third Generation Partnership Project). .

  In the NR system, similarly to dual connectivity in the LTE system, LTE divides data between a base station (eNB) of the LTE system and a base station (gNB) of the NR system, and transmits and receives data simultaneously by these base stations. The introduction of -NR dual connectivity (LTE-NR DC) or multi-RAT dual connectivity (MR DC) is under consideration. For example, in LTE-NR DC, as shown in FIG. 1, downlink data for a user equipment (UE) is transmitted between an LTE base station (eNB) and an NR base station (gNB) via an X2 interface or an Xn interface. And data are simultaneously transmitted from these base stations to the user equipment.

  In addition, as shown in FIG. 2, dual connectivity between base stations of the NR system is also considered. That is, the downlink data for the user equipment (UE) is distributed to a plurality of base stations (Distributed Unit: DU) via the F1 interface by the base station (Central Unit: CU) of the NR system, and from these base stations to the user equipment Data is transmitted simultaneously.

R3-172456

  After data distribution to multiple base stations in dual connectivity, if the throughput of data transmission from a certain base station is not sufficient, there is a possibility that data to be transmitted will stay in the base station and data reception in the user equipment will be delayed is there. In order to avoid such stagnation of transmission target data, it is considered that the stagnation data is redistributed between base stations.

  An object of the present invention is to realize early transmission of redistributed transmission target data in distributed communication.

  In order to solve the above-described problem, an aspect of the present invention includes a wireless communication unit that performs wireless communication with a user device, and a storage unit that stores transmission target data transmitted to the user device for which dual connectivity is set. The wireless communication unit receives the second transmission target data redistributed from another base station in preference to the first transmission target data already stored in the storage unit. The present invention relates to a base station that transmits to the user apparatus.

  According to the present invention, it is possible to realize early transmission of redistributed transmission target data in distributed communication.

FIG. 1 is a schematic diagram illustrating LTE-NR dual connectivity. FIG. 2 is a schematic diagram showing inter-DU dual connectivity. FIG. 3 is a schematic diagram showing a stay packet redistribution process according to the prior art. FIG. 4 is a schematic diagram illustrating a wireless communication system according to an embodiment of the present invention. FIG. 5 is a block diagram showing a functional configuration of a base station according to an embodiment of the present invention. FIG. 6 is a flowchart showing a redistribution process according to an embodiment of the present invention. FIG. 7 is a block diagram illustrating a hardware configuration of a base station and a user apparatus according to an embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In the following embodiments, distributed communication between base stations such as LTE-NR dual connectivity and DU dual connectivity, ie, a base station that supports dual connectivity is disclosed.

  In conventional dual connectivity, after distributing data to each node, if the throughput of the node is lower than expected due to changes in the wireless environment, an increase in load at the node, an error in distribution, etc. Transmission target packets remain, and the throughput in the application layer of the user apparatus deteriorates. For example, as illustrated in FIG. 3A, in the LTE-NR dual connectivity, when the transmission target packet stays in the gNB, the user apparatus waits for reception of the packet having the sequence number “4” from the gNB. The received packets with sequence numbers “5” and “7” are not sent to the application layer, and data reception in the user apparatus is delayed. In this case, as shown in FIG. 3B, the staying packet can be canceled by redistributing the staying packet in the gNB to the eNB.

  However, according to the prior art, when the stay packet is redistributed from the other node of dual connectivity in this way, as shown in FIG. 3B, the stay packet is added to the end of the queue of the redistribution eNB, This will increase the reordering delay in the user equipment. Such a reordering delay may cause the reordering timer to expire before the stay packet is received, and it may be considered that a packet loss has occurred by an upper layer.

  For this reason, in the Example mentioned later, a base station transmits with priority over the transmission object data which already hold | maintain the transmission object data redistributed in dual connectivity. Thereby, the reordering delay in a user apparatus can be reduced.

  First, a radio communication system according to an embodiment of the present invention will be described with reference to FIG. FIG. 4 is a schematic diagram illustrating a wireless communication system according to an embodiment of the present invention.

  As illustrated in FIG. 4, the user apparatus 200 is connected to and communicates with the base stations 101 and 102 (hereinafter also referred to as the base station 100) of the LTE system and / or the NR system. And support dual connectivity. That is, the user apparatus 200 can simultaneously transmit or receive data divided with the base stations 101 and 102 by simultaneously using a plurality of component carriers provided by the base stations 101 and 102.

  For example, in LTE-NR dual connectivity, downlink data addressed to the user equipment 200 from a core network (not shown) is distributed between the base stations 101 and 102 via the X2 interface or the Xn interface. Each of 102 is transmitted to the user apparatus 200. In the inter-DU dual connectivity, downlink data addressed to the user apparatus 200 from the core network (not shown) is transmitted between the base stations 101 and 102 functioning as DUs via the F1 interface by the base station 100 functioning as CUs. And transmitted from each of the base stations 101 and 102 to the user apparatus 200. However, the embodiment of the present invention is not limited to the LTE-NR dual connectivity and the inter-DU dual connectivity as described above, but dual connectivity by a combination of these, dual connectivity using three or more nodes, 3GPP It can be applied to any appropriate distributed communication and dual connectivity including dual connectivity between a wireless communication system that complies with 3GPP and a wireless communication system that does not comply with 3GPP. For example, as dual connectivity or multi-connectivity using three or more nodes, distributed communication between an LTE base station (eNB) and NR base stations CU and DU may be included. Throughout this specification, the term dual connectivity also covers such distributed communication or multi-connectivity using three or more nodes.

  In the illustrated embodiment, the radio communication system 10 has only two base stations 101 and 102, but in general, a large number of base stations 100 are arranged to cover the service area of the radio communication system 10. The

  Next, a base station according to an embodiment of the present invention will be described with reference to FIG. The base station 100 according to the present embodiment transmits the distributed downlink data to the user equipment 200, and when the downlink data is redistributed, the downlink already holding the redistributed downlink data. Send with priority over data. For example, in LTE-NR dual connectivity, the base station 100 is an eNB or gNB, and in the inter-DU dual connectivity in the NR system, the base station 100 is a DU.

  FIG. 5 is a block diagram showing a functional configuration of a base station according to an embodiment of the present invention. As illustrated in FIG. 5, the base station 100 includes a wireless communication unit 110 and a storage unit 120.

  The wireless communication unit 110 performs wireless communication with the user device 200. Specifically, the radio communication unit 110 transmits various downlink signals such as a downlink control channel and a downlink data channel to the user apparatus 200, and various uplink signals such as an uplink control channel and an uplink data channel. Is received from the user apparatus 200. In addition, when dual connectivity is set for the user apparatus 200, the radio communication unit 110 transmits downlink data distributed in cooperation with other base stations to the user apparatus 200.

  In addition, the wireless communication unit 110 transmits the transmission target data redistributed from another base station to the user apparatus 200 in preference to the transmission target data already stored in the storage unit 120. In the dual connectivity, when a stay packet in a certain base station is redistributed to the base station 100, the wireless communication unit 110 transmits the redistributed packet to the user apparatus 200 quickly. The packet redistributed with priority over the packet already stored in 120 is transmitted to the user apparatus 200. As a result, the user apparatus 200 can receive the packet waiting for reception at an early stage, and can reduce the reordering delay.

  The storage unit 120 stores transmission target data to be transmitted to the user device 200 for which dual connectivity is set. Specifically, the storage unit 120 stores packets redistributed from other base stations together with the packets distributed initially. At this time, the storage unit 120 stores the redistributed packet higher in the queue than the originally distributed packet so that the redistributed packet is transmitted with higher priority than the originally distributed packet. Also good. Specifically, the storage unit 120 may store the redistributed transmission target data by shifting, deleting, or overwriting the transmission target data that has already been stored. In this case, after the redistributed transmission target data is transmitted, the storage unit 120 may re-store the originally distributed transmission target data that has been shifted, deleted, or overwritten.

  In one embodiment, the storage unit 120 may store the redistributed transmission target data in a predetermined storage location. Specifically, the storage unit 120 may store the redistributed transmission target data in a higher storage position in the queue so that the redistributed transmission target data is transmitted early. For example, the predetermined storage position may be the head storage position in the queue, and the wireless communication unit 110 may execute transmission from the transmission target data at the head storage position in the queue to the user apparatus 200. . According to the present embodiment, the redistributed transmission target data can be transmitted to the user apparatus 200 at an early stage, and the reordering delay can be reduced.

  Further, in one embodiment, the storage unit 120 may store the transmission target data redistributed based on the sequence number, and the wireless communication unit 110 transmits the data stored in the storage unit 120 according to the sequence number order. The target data may be transmitted to the user device 200. That is, the storage unit 120 determines the priority order of the redistributed transmission target data based on the sequence number of each transmission target packet, and determines the redistributed packet and the already held packet in ascending order of the sequence number. It may be rearranged in the queue. At this time, the wireless communication unit 110 transmits the packets rearranged in ascending order of the sequence numbers to the user apparatus 200 according to the order of the sequence numbers. For example, in the specific example shown in FIG. 3A, when the packets with the sequence numbers “6” and “8” are redistributed to the base station 100 that already holds the packet with the sequence number “9”, the storage unit 120 Packets may be rearranged in the queue in the ascending order of sequence numbers of distributed packets and already held packets, that is, in the order of sequence numbers “6”, “8”, and “9”. At this time, the wireless communication unit 110 transmits these packets to the user apparatus 200 in ascending order of sequence numbers. According to the present embodiment, it becomes possible to transmit the redistributed transmission target data and the already held transmission target data in the order of the sequence numbers, thereby reducing the reordering delay.

  Next, redistribution processing according to an embodiment of the present invention will be described with reference to FIG. FIG. 6 is a flowchart showing a redistribution process according to an embodiment of the present invention.

  As shown in FIG. 6, the redistribution process is executed by, for example, the base station 100 in which dual connectivity is set. For example, in LTE-NR dual connectivity, the base station 100 is an eNB or gNB, and in the inter-DU dual connectivity in the NR system, the base station 100 is a DU.

  In step S101, the base station 100 determines whether transmission target data has been redistributed. For example, when a predetermined redistribution condition is satisfied, for example, a packet exceeding a threshold amount stays in another base station in dual connectivity, the staying packet may be redistributed to the base station 100. When transmission target data is redistributed from another base station (S101: YES), the process proceeds to step S102.

  In step S102, the base station 100 transmits the redistributed transmission target data to the user apparatus 200 with priority over the transmission target data already held. In one example, the base station 100 may store the redistributed transmission target data in a predetermined storage position such as a higher storage position of the queue, and transmit the redistributed transmission target data to the user apparatus 200 at an early stage. . In another example, the base station 100 reorders the transmission target data redistributed according to the sequence number of the packet and the transmission target data already held in the queue, and transmits the transmission target data to the user apparatus 200 according to the sequence number. May be.

  In addition, the block diagram used for description of the said embodiment has shown the block of the functional unit. These functional blocks (components) are realized by any combination of hardware and / or software. Further, the means for realizing each functional block is not particularly limited. That is, each functional block may be realized by one device physically and / or logically coupled, and two or more devices physically and / or logically separated may be directly and / or indirectly. (For example, wired and / or wireless) and may be realized by these plural devices.

  For example, the user apparatus 200 and the base station 100 in an embodiment of the present invention may function as a computer that performs processing of the wireless communication method of the present invention. FIG. 7 is a block diagram illustrating a hardware configuration of the user apparatus 200 and the base station 100 according to an embodiment of the present invention. The above-described user apparatus 200 and base station 100 may be physically configured as a computer apparatus including a processor 1001, a memory 1002, a storage 1003, a communication apparatus 1004, an input apparatus 1005, an output apparatus 1006, a bus 1007, and the like. .

  In the following description, the term “apparatus” can be read as a circuit, a device, a unit, or the like. The hardware configurations of the user apparatus 200 and the base station 100 may be configured to include one or a plurality of the apparatuses illustrated in the figure, or may be configured not to include some apparatuses.

  Each function in the user apparatus 200 and the base station 100 is obtained by reading predetermined software (program) on hardware such as the processor 1001 and the memory 1002, so that the processor 1001 performs calculation, and communication by the communication apparatus 1004 or memory This is realized by controlling data reading and / or writing in the storage 1003 and the storage 1003.

  For example, the processor 1001 controls the entire computer by operating an operating system. The processor 1001 may be configured by a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic device, a register, and the like. For example, each component described above may be realized by the processor 1001.

  Further, the processor 1001 reads a program (program code), software module, and data from the storage 1003 and / or the communication device 1004 to the memory 1002, and executes various processes according to these. As the program, a program that causes a computer to execute at least a part of the operations described in the above embodiments is used. For example, processing by each component of the user apparatus 200 and the base station 100 may be realized by a control program stored in the memory 1002 and operated by the processor 1001, or may be realized similarly for other functional blocks. . Although the above-described various processes have been described as being executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. Note that the program may be transmitted from a network via a telecommunication line.

  The memory 1002 is a computer-readable recording medium and includes, for example, at least one of ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), and the like. May be. The memory 1002 may be called a register, a cache, a main memory (main storage device), or the like. The memory 1002 can store a program (program code), a software module, and the like that can be executed to implement the wireless communication method according to the embodiment of the present invention.

  The storage 1003 is a computer-readable recording medium, such as an optical disc such as a CD-ROM (Compact Disc ROM), a hard disc drive, a flexible disc, a magneto-optical disc (eg, a compact disc, a digital versatile disc, a Blu-ray). (Registered trademark) disk, smart card, flash memory (for example, card, stick, key drive), floppy (registered trademark) disk, magnetic strip, and the like. The storage 1003 may be referred to as an auxiliary storage device. The storage medium described above may be, for example, a database, server, or other suitable medium including the memory 1002 and / or the storage 1003.

  The communication device 1004 is hardware (transmission / reception device) for performing communication between computers via a wired and / or wireless network, and is also referred to as a network device, a network controller, a network card, a communication module, or the like. For example, each of the above-described components may be realized by the communication device 1004.

  The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, or the like) that accepts an external input. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that performs output to the outside. The input device 1005 and the output device 1006 may have an integrated configuration (for example, a touch panel).

  Each device such as the processor 1001 and the memory 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured with a single bus or may be configured with different buses between apparatuses.

  In addition, the user apparatus 200 and the base station 100 include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), and a field programmable gate array (FPGA). Hardware may be configured, and a part or all of each functional block may be realized by the hardware. For example, the processor 1001 may be implemented by at least one of these hardware.

  The notification of information is not limited to the aspect / embodiment described in the present specification, and may be performed by other methods. For example, information notification includes physical layer signaling (for example, DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (for example, RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling), It may be implemented by broadcast information (MIB (Master Information Block), SIB (System Information Block))), other signals, or a combination thereof. The RRC signaling may be referred to as an RRC message, and may be, for example, an RRC connection setup message, an RRC connection reconfiguration message, or the like.

  Each aspect / example described in this specification includes LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G, 5G, Future Radio Access (FRA), W-CDMA. (Registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, UWB (Ultra-WideBand), The present invention may be applied to a Bluetooth (registered trademark), a system using another appropriate system, and / or a next generation system extended based on the system.

  As long as there is no contradiction, the order of the processing procedures, sequences, flowcharts, and the like of each aspect / example described in this specification may be changed. For example, the methods described herein present the elements of the various steps in an exemplary order and are not limited to the specific order presented.

  The specific operation assumed to be performed by the base station 100 in this specification may be performed by its upper node in some cases. In a network composed of one or more network nodes having a base station, various operations performed for communication with a terminal may be performed by the base station and / or other network nodes other than the base station (e.g., Obviously, this can be done by MME or S-GW, but not limited to these. Although the case where there is one network node other than the base station in the above is illustrated, a combination of a plurality of other network nodes (for example, MME and S-GW) may be used.

  Information or the like can be output from the upper layer (or lower layer) to the lower layer (or upper layer). Input / output may be performed via a plurality of network nodes.

  Input / output information and the like may be stored in a specific location (for example, a memory) or may be managed by a management table. Input / output information and the like can be overwritten, updated, or additionally written. The output information or the like may be deleted. The input information or the like may be transmitted to another device.

  The determination may be performed by a value represented by 1 bit (0 or 1), may be performed by a true / false value (Boolean: true or false), or may be performed by comparing numerical values (for example, a predetermined value) Comparison with the value).

  Each aspect / example demonstrated in this specification may be used independently, may be used in combination, and may be switched and used with execution. In addition, notification of predetermined information (for example, notification of being “X”) is not limited to explicitly performed, but is performed implicitly (for example, notification of the predetermined information is not performed). Also good.

  Although the present invention has been described in detail above, it will be apparent to those skilled in the art that the present invention is not limited to the embodiments described herein. The present invention can be implemented as modified and changed modes without departing from the spirit and scope of the present invention defined by the description of the scope of claims. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present invention.

  Software, whether it is called software, firmware, middleware, microcode, hardware description language, or other names, instructions, instruction sets, codes, code segments, program codes, programs, subprograms, software modules , Applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc. should be interpreted broadly.

  Also, software, instructions, etc. may be transmitted / received via a transmission medium. For example, software may use websites, servers, or other devices using wired technology such as coaxial cable, fiber optic cable, twisted pair and digital subscriber line (DSL) and / or wireless technology such as infrared, wireless and microwave. When transmitted from a remote source, these wired and / or wireless technologies are included within the definition of transmission media.

  Information, signals, etc. described herein may be represented using any of a variety of different technologies. For example, data, commands, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description are voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of these May be represented by a combination of

  Note that the terms described in this specification and / or terms necessary for understanding this specification may be replaced with terms having the same or similar meaning. For example, the channel and / or symbol may be a signal. The signal may be a message. Further, the component carrier (CC) may be called a carrier frequency, a cell, or the like.

  As used herein, the terms “system” and “network” are used interchangeably.

  In addition, information, parameters, and the like described in this specification may be represented by absolute values, may be represented by relative values from a predetermined value, or may be represented by other corresponding information. . For example, the radio resource may be indicated by an index.

  The names used for the parameters described above are not limiting in any way. Further, mathematical formulas and the like that use these parameters may differ from those explicitly disclosed herein. Since various channels (eg, PUCCH, PDCCH, etc.) and information elements (eg, TPC, etc.) can be identified by any suitable name, the various names assigned to these various channels and information elements are However, it is not limited.

  A base station may accommodate one or more (eg, three) cells (also referred to as sectors). When the base station accommodates a plurality of cells, the entire coverage area of the base station can be divided into a plurality of smaller areas, and each smaller area can be divided into a base station subsystem (for example, an indoor small base station RRH: Remote). Communication service can also be provided by Radio Head). The term “cell” or “sector” refers to part or all of the coverage area of a base station and / or base station subsystem that provides communication services in this coverage. Further, the terms “base station”, “eNB”, “cell”, and “sector” may be used interchangeably herein. A base station may also be referred to in terms such as a fixed station, NodeB, eNodeB (eNB), access point, femtocell, small cell, and the like.

  A mobile station is defined by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless It may also be called terminal, remote terminal, handset, user agent, mobile client, client, or some other appropriate terminology.

  As used herein, the terms “determining” and “determining” may encompass a wide variety of actions. “Judgment”, “decision” can be, for example, calculating, computing, processing, deriving, investigating, looking up (eg, table, database or another (Searching in the data structure), and confirming (ascertaining) what has been confirmed may be considered as “determining” or “determining”. In addition, “determination” and “determination” include receiving (for example, receiving information), transmitting (for example, transmitting information), input (input), output (output), and access. (accessing) (e.g., accessing data in a memory) may be considered as "determined" or "determined". In addition, “determination” and “decision” means that “resolving”, “selecting”, “choosing”, “establishing”, and “comparing” are regarded as “determining” and “deciding”. May be included. In other words, “determination” and “determination” may include considering some operation as “determination” and “determination”.

  The terms “connected”, “coupled”, or any variation thereof, means any direct or indirect connection or coupling between two or more elements and It can include the presence of one or more intermediate elements between two “connected” or “coupled” elements. The coupling or connection between the elements may be physical, logical, or a combination thereof. As used herein, the two elements are radio frequency by using one or more wires, cables and / or printed electrical connections, and as some non-limiting and non-inclusive examples By using electromagnetic energy, such as electromagnetic energy having a wavelength in the region, microwave region, and light (both visible and invisible) region, it can be considered to be “connected” or “coupled” to each other.

  The reference signal may be abbreviated as RS (Reference Signal), and may be referred to as a pilot depending on an applied standard.

  As used herein, the phrase “based on” does not mean “based only on,” unless expressly specified otherwise. In other words, the phrase “based on” means both “based only on” and “based at least on.”

  Any reference to elements using the designations "first", "second", etc. as used herein does not generally limit the amount or order of those elements. These designations can be used herein as a convenient way to distinguish between two or more elements. Thus, a reference to the first and second elements does not mean that only two elements can be employed there, or that in some way the first element must precede the second element.

  The “means” in the configuration of each apparatus described above may be replaced with “unit”, “circuit”, “device”, and the like.

  These terms are similar to the term “comprising” as long as “including”, “including”, and variations thereof, are used herein or in the claims. It is intended to be comprehensive. Furthermore, the term “or” as used herein or in the claims is not intended to be an exclusive OR.

  A radio frame may be composed of one or more frames in the time domain. Each frame or frames in the time domain may be referred to as a subframe. A subframe may further be composed of one or more slots in the time domain. A slot may further be composed of one or more symbols (OFDM symbols, SC-FDMA symbols, etc.) in the time domain. Each of the radio frame, subframe, slot, and symbol represents a time unit for transmitting a signal. Radio frames, subframes, slots, and symbols may be called differently corresponding to each. For example, in the LTE system, the base station performs scheduling for allocating radio resources (frequency bandwidth, transmission power, etc. that can be used in each mobile station) to each mobile station. The minimum scheduling time unit may be referred to as TTI (Transmission Time Interval). For example, one subframe may be called a TTI, a plurality of consecutive subframes may be called a TTI, and one slot may be called a TTI. A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or a plurality of continuous subcarriers in the frequency domain. In the time domain of the resource block, one or a plurality of symbols may be included, and one slot, one subframe, or a length of 1 TTI may be included. One TTI and one subframe may each be composed of one or a plurality of resource blocks. The structure of the radio frame described above is merely an example, and the number of subframes included in the radio frame, the number of slots included in the subframe, the number of symbols and resource blocks included in the slots, and the subframes included in the resource block The number of carriers can be variously changed.

  As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the specific embodiment mentioned above, In the range of the summary of this invention described in the claim, various deformation | transformation・ Change is possible.

10 wireless communication system 100, 101, 102 base station 110 wireless communication unit 120 storage unit 200 user apparatus

Claims (6)

A wireless communication unit that performs wireless communication with the user device;
A storage unit for storing transmission target data to be transmitted to the user apparatus for which dual connectivity is set;
A base station having
The radio communication unit is a base station that transmits second transmission target data redistributed from another base station to the user apparatus in preference to the first transmission target data already stored in the storage unit.   The base station according to claim 1, wherein the storage unit stores the redistributed second transmission target data in a predetermined storage location. The predetermined storage position is a head storage position in the queue,
The base station according to claim 2, wherein the wireless communication unit executes transmission from the transmission target data at the head storage position in the queue to the user apparatus.   The base station according to claim 1, wherein the storage unit stores the second transmission target data redistributed based on a sequence number.   The base station according to claim 4, wherein the wireless communication unit transmits the transmission target data stored in the storage unit to the user apparatus in accordance with the order of the sequence numbers.   6. The storage unit according to claim 1, wherein the storage unit stores the redistributed second transmission target data by shifting, deleting, or overwriting the already stored first transmission target data. The base station described in the section.

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