WO2013141294A1 - Communication system, mobile station device, base station device, and communication method - Google Patents

Abstract

This communication system is provided with a macrocell base station device, a compact base station device that sets a region of part of the cell of the macrocell base station device as a cell, and a mobile station device. The mobile station device is provided with: a transmission/reception unit that uses a first frequency band to communicate with the macrocell base station device or the compact base station device; and a communication control unit that uses a second frequency band that is different from the first frequency band to generate request information indicating that communication with the compact base station device or the macrocell base station device with which communication is not being performed by the transmission/reception unit is requested, and transmits the request information to the macrocell base station device or the compact base station device with which communication is being performed by the transmission/reception unit.

Description

COMMUNICATION SYSTEM, MOBILE STATION DEVICE, BASE STATION DEVICE, AND COMMUNICATION METHOD

The present invention relates to a communication system, a mobile station apparatus, a base station apparatus, and a communication method.
This application claims priority based on Japanese Patent Application No. 2012-063884 filed in Japan on March 21, 2012 and Japanese Patent Application No. 2012-063885 filed on March 21, 2012 in Japan And the contents thereof are incorporated herein.

In wireless communication, data is transmitted and received using radio waves between a base station device and a mobile station device. In LTE-A (Long Term Evolution-Advanced), which is one of the wireless communication standards, it is allowed to use various mobile station apparatuses for communication. The types of ranges covered by the base station device include, for example, a macro cell (also called a macro cell) and a micro cell (also called a micro cell, pico cell, femto cell, and H). A macro cell is a cell with a large range in which radio waves reach a mobile station device (for example, a radius of several hundreds to several tens of kilometers). A microcell is a cell that has a smaller range in which radio waves reach a mobile station device (for example, a radius of several meters to several hundred meters).

As a communication system in which macro cells and micro cells are mixed, there is an access method arrangement method described in Patent Document 1, for example. In Patent Literature 1, when an MME (Mobility Management Entity) receives an overload notification message from the eNB (base station apparatus) that instructs an eNB cell to be overloaded, an MNB (Mobility Management Entity) selects an HeNB corresponding to the eNB cell. It is described that an identification is made (a plurality of identified HeNBs may exist), and an instruction is sent to this HeNB to change the HeNB access method from a closed method to a release method or a hybrid method. ing.

JP 2011-4399 A

However, according to the communication system described in Patent Literature 1, when an overload occurs in the eNB, the access methods of all corresponding HeNBs in the coverage of the eNB cell are switched. Since the mobile station apparatus cannot access a specific HeNB, the frequency resource utilization efficiency may be reduced.
Further, according to the communication system described in Patent Document 1, when an overload occurs in a certain base station device, the access methods of all the base station devices that overlap the cell coverage of the base station device are switched. That is, since the mobile station device cannot access another base station device by specifying it, the frequency resource utilization efficiency may be reduced.

The present invention has been made in view of the above points, and provides a communication system, a mobile station apparatus, a base station apparatus, and a communication method that do not reduce the use efficiency of frequency resources.

(1) The present invention has been made to solve the above-described problems, and a first aspect of the present invention is a macro cell base station apparatus, and a partial area of a cell of the macro cell base station apparatus is defined as a cell. A communication system comprising a small base station device and a mobile station device, wherein the mobile station device communicates with the macrocell base station device or the small base station device using a first frequency band; Generating request information indicating requesting communication with a small base station device or a macro cell base station device that is not communicating with the transceiver using a second frequency band different from the first frequency band; A communication control unit comprising: a communication control unit that transmits the request information to the macro cell base station device or the small base station device communicating with the transmission / reception unit.

(2) In the first aspect of the present invention, the mobile station device includes a communication measurement unit that measures a communication amount with the macro cell base station device or the small base station device, and the communication control unit includes the communication control unit, Whether or not to communicate using the second frequency band may be determined based on the communication amount measured by the communication measurement unit.

(3) In the first aspect of the present invention, the communication control unit may search for a small base station apparatus or a macro cell base station apparatus that can communicate using the second frequency band.

(4) In the first aspect of the present invention, the communication control unit transmits, as the request information, location information indicating presence in a cell of the searched small base station device or macro cell base station device. You may do it.

(5) In the first aspect of the present invention, the communication control unit adds the request information to measurement information related to communication with the macro cell base station apparatus or the small base station apparatus, and the macro cell base station apparatus or You may transmit to the said small base station apparatus.

(6) In the first aspect of the present invention, when the communication control unit detects a plurality of communicable small base station devices or macro cell base station devices, the small base station device or macro cell base station having the highest communication quality is detected. A device may be selected.

(7) A second aspect of the present invention is a communication system including a macro cell base station device, a small base station device that uses a partial area of a cell of the macro cell base station device as a cell, and a mobile station device. The macro cell base station apparatus or the small base station apparatus uses a transmission / reception unit that communicates with the mobile station apparatus using a first frequency band, and a second frequency band different from the first frequency band. Request information indicating that communication between the mobile station device and a small base station device or macro cell base station device that is not communicating with the transceiver unit is generated, and the request information is communicated with the transceiver unit A communication control unit that transmits to the mobile station device.

(8) A third aspect of the present invention is a transmission / reception unit that communicates with a macro cell base station apparatus or a small base station apparatus that uses a partial area of a cell of the macro cell base station apparatus as a cell using the first frequency band. And request information representing requesting communication with a small base station apparatus or macrocell base station apparatus that is not communicating with the transceiver using a second frequency band different from the first frequency band. And a communication control unit that transmits the request information to the macro cell base station device or the small base station device communicating with the transmission / reception unit.

(9) According to a fourth aspect of the present invention, there is provided a transmitting / receiving unit that communicates with a mobile station device using a first frequency band, and the transmitting / receiving unit using a second frequency band different from the first frequency band. A request that indicates a request for communication between the mobile station apparatus and the macro cell base station apparatus that is not communicating with the small cell base station apparatus or the macro cell base station apparatus that uses a partial area of the cell of the macro cell base station apparatus as a cell. A communication control unit that generates information and transmits the request information to the mobile station device that is communicating with the transmission / reception unit.

(10) A fifth aspect of the present invention is a communication method in a mobile station device, wherein the mobile station device is a small cell having a macro cell base station device or a partial area of a cell of the macro cell base station device as a cell. A small base station apparatus or a macro cell base that communicates with a base station apparatus using a first frequency band, and the mobile station apparatus does not communicate with a second frequency band different from the first frequency band. A communication method for generating request information indicating requesting communication with a station apparatus, and transmitting the request information to the macro cell base station apparatus or the small base station apparatus with which communication is performed.

(11) A sixth aspect of the present invention is a communication method in a macro cell base station apparatus or a small base station apparatus that uses a partial area of a cell of the macro cell base station apparatus as a cell, the macro cell base station apparatus or The small base station apparatus communicates with a mobile station apparatus using a first frequency band, and the macro cell base station apparatus or the small base station apparatus has a second frequency band different from the first frequency band. And generating request information indicating requesting communication between the mobile station device and a small base station device or macrocell base station device that is not communicating, and sending the request information to the mobile station device that is communicating A communication method for transmission.

According to the embodiment of the present invention, the utilization efficiency of frequency resources does not decrease.

1 is a conceptual diagram illustrating a communication system according to a first embodiment of the present invention. It is a conceptual diagram showing an example of the frequency band used for transmission / reception of the data which concerns on 1st Embodiment. It is a conceptual diagram showing the other example of the frequency band used for transmission / reception of the data which concerns on 1st Embodiment. It is a conceptual diagram showing the other example of the frequency band used for transmission / reception of the data which concerns on 1st Embodiment. It is the schematic showing the structure of the communication system which concerns on 1st Embodiment. It is the schematic showing the structure of UE which concerns on 1st Embodiment. It is the schematic showing the structure of eNB which concerns on 1st Embodiment. It is the schematic showing the structure of HeNB which concerns on 1st Embodiment. It is a sequence diagram showing the communication process which concerns on 1st Embodiment. It is a flowchart showing the HeNB search process which concerns on 1st Embodiment. It is a sequence diagram showing the modification of the communication processing which concerns on 1st Embodiment. It is a sequence diagram showing the other modification of the communication processing which concerns on 1st Embodiment. It is a sequence diagram showing the other modification of the communication processing which concerns on 1st Embodiment. It is the schematic showing the structure of the communication system which concerns on the 2nd Embodiment of this invention. It is the schematic showing the structure of eNB which concerns on 2nd Embodiment. It is a sequence diagram showing the communication processing which concerns on 2nd Embodiment. It is a conceptual diagram showing an example of the frequency band used for transmission / reception of the data which concerns on 3rd Embodiment. It is a conceptual diagram showing another example of the frequency band used for transmission / reception of the data which concerns on 3rd Embodiment. It is a conceptual diagram showing the other example of the frequency band used for transmission / reception of the data which concerns on 3rd Embodiment. It is the schematic showing the structure of the communication system which concerns on 3rd Embodiment. It is the schematic showing the structure of HeNB which concerns on 3rd Embodiment. It is the schematic showing the structure of eNB which concerns on 3rd Embodiment. It is a sequence diagram showing the communication processing which concerns on 3rd Embodiment. It is a flowchart showing the eNB search process which concerns on 3rd Embodiment. It is a sequence diagram showing the modification of the communication processing which concerns on 3rd Embodiment. It is a sequence diagram showing the other modification of the communication processing which concerns on 3rd Embodiment. It is a sequence diagram showing the other modification of the communication processing which concerns on 3rd Embodiment. It is the schematic showing the structure of the communication system which concerns on the 4th Embodiment of this invention. It is the schematic showing the structure of HeNB which concerns on 4th Embodiment. It is a sequence diagram showing the communication processing which concerns on 4th Embodiment.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a conceptual diagram showing a communication system 1a according to the first embodiment.
The communication system 1a includes an eNB 12, a HeNB 13-1, 13-2, 13-3, and a UE. The HeNBs 13-1, 13-2, and 13-3 may be collectively referred to as HeNB13.

The eNB 12 is a macro cell base station apparatus (macro cell eNodeB) that transmits and receives data wirelessly to and from the UE 14. UE (User Equipment) is another name for a mobile station apparatus. In FIG. 1, a cell 32 is a macro cell that represents a range in which radio waves of the eNB 12 reach, that is, a range in which data can be transmitted and received with the UE 14. The radius of the cell 32 is, for example, a relatively wide range of several hundred m to several km. That is, the macro cell base station apparatus is a base station apparatus that has a wide communication range with the mobile station apparatus (typically, a radius of several hundreds to several tens of kilometers).
The HeNBs 13-1, 13-2, and 13-3 are small base station devices (Home eNodeB [indoor base station device], micro cell eNodeB [micro cell base station device]) that transmit and receive data wirelessly with the UE 14. pico cell eNodeB [picocell base station apparatus] and femto cell eNodeB [femtocell base station apparatus]). In the first embodiment, the number of HeNBs is not limited to three as illustrated, and may be one, two, or more than three.

In FIG. 1, cells 33-1, 33-2, and 33-3 represent ranges where radio waves of HeNBs 13-1, 13-2, and 13-3 reach, respectively. The radii of the cells 33-1, 33-2, 33-3 are in a relatively narrow range of, for example, several meters to several tens of meters. The areas of the cells 33-1, 33-2, and 33-3 shown in FIG. 1 are all included in the area of the cell 32. The cells 33-1, 33-2, and 33-3 may be collectively referred to as the cell 33. That is, the small base station device is a base station device that has a narrow communication range with the mobile station device (typically a radius of several meters to several tens of meters).

The cell 33 provided by the HeNB 13 may be any of the following types (1) to (3). (1) Open cell: Similar to a macro cell, it is a cell to which all UEs can be connected. As the identification information of the open cell, for example, PCI (Physical Cell Identity) in the same format as the macro cell is used. (2) CSG cell (Closed Subscriber Group cell): A cell to which only a subscriber UE (CSG member) limited in advance can connect. Such a group of subscribers is called a CSG. As the identification information of the CSG cell, for example, PCI dedicated to CSG is used. A CSG-ID is transmitted as a part of the system information to UEs located in the CSG cell, that is, within the coverage range. The system information is control information common to UEs in the area. The CSG-ID is CSG identification information. (3) Hybrid cell: A cell that can be connected to a CSG member as a CSG cell and to a non-CSG member as an open cell. Therefore, PCI having the same format as that of an open cell is used as hybrid cell identification information. Further, the CSG-ID is transmitted as a part of the system information to UEs located in the hybrid cell. The HeNB 13 may allocate frequency resources with priority over CSG members over non-CSG members.

The UE 14 is a mobile station device (User Equipment) that transmits and receives data wirelessly with at least one of the eNB 12 and the HeNBs 13-1, 13-2, and 13-3. The UE 14 is, for example, a mobile phone or a personal digital assistant (PDA).
In the following description, when the eNB 12 and the HeNBs 13-1, 13-2, and 13-3 are not distinguished from each other or when they are collectively referred to, they may be simply referred to as base station apparatuses. Further, when the HeNBs 13-1, 13-2, and 13-3 are not distinguished from each other, or are collectively referred to, they may be simply referred to as HeNB13.

The communication system 1a according to the first embodiment includes an eNB 12, a HeNB 13 having a partial area of the cell 32 as a cell, and a UE. UE14 communicates with eNB12 using the electromagnetic wave of a certain frequency band A1 (henceforth the band A1). UE14 produces | generates the request information showing requesting | requiring communication with HeNB13 using frequency band B1 different from frequency band A1. The UE 14 transmits the generated request information to the eNB 12. Thereby, the communication system 1a performs carrier aggregation (CA).

(Carrier aggregation)
Next, CA will be described. CA is a technology that aggregates (aggregates) two or more different frequency bands (component carriers; component carriers, CCs), and simultaneously transmits and receives data using these frequency bands. CC is a unit of a communication band in which data is allocated for each UE. The CC includes a plurality of resource blocks (RBs). RB is a unit (for example, 180 kHz) of a frequency band to which data in an OFDM (Orthogonal Frequency Division Multiplexing) signal frame is assigned.

2A and 2B are conceptual diagrams illustrating an example of a frequency band used for data transmission / reception. In both FIG. 2A and FIG. 2B, the horizontal axis represents frequency.
FIG. 2A shows that the eNB 12 transmits data to the UE 14 using PCC (Primary Component Carrier) of the band A1 before the CA process.

FIG. 2B shows that after the CA process, the eNB 12 transmits data to the UE 14 using the PCC of the band A1, and at the same time, the HeNB 13-1 uses the SCC (Secondary Component Carrier, secondary component carrier) of the band B1 to the UE 14. Represents sending data. At this time, the UE 14 receives data from the same counterpart device (for example, another mobile station device) using the band A1 and the band B1 via the eNB 12 and the HeNB 13-1, respectively. Therefore, CA refers to virtually expanding the frequency band by simultaneously using a plurality of CCs for communication with the same counterpart device. CA refers to communication using an expanded frequency band. Sometimes. In the above example, the band A1 (first frequency band) is the band used from the beginning before expanding the band between the eNB (macrocell base station apparatus) 12 and the UE (mobile station apparatus) 14. When extending the band, the newly added band between the HeNB 13-1 (small base station apparatus) and the UE 14 (mobile station apparatus) is the band B1 (second frequency band). That is, CA is to aggregate the band A1 (first frequency band) and the band B1 (second frequency band) and perform communication between the UE 14 and the counterpart device.

The CCs to be aggregated may be frequency bands separated from each other as shown in FIGS. 2A and 2B, or may be frequency bands adjacent to each other. The band of each CC may be any band (for example, any one of 800 MHz, 2.4 GHz, and 3.4 GHz). The bandwidth of each CC may be any bandwidth (for example, any of 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz). Further, the bandwidth and center frequency of each CC may be different between the uplink and the downlink.

Note that the PCC is a frequency band that serves as a reference for measurement control such as reception quality performed by the UE 14, detection of a downlink radio link failure, and transmission of an uplink control channel. The PCC is a main band assigned to each UE. The SCC is a frequency band assigned to the UE other than the PCC. System information to be described later may include information representing PCC and information representing SCC used for communication with the UE 14 for each base station apparatus.

The number of CCs to be aggregated is not limited to two, and may be an integer greater than one (for example, three). Of these, the number of SCCs is not limited to one, and may be an integer greater than one.
FIG. 3 is a conceptual diagram illustrating another example of a frequency band used for data transmission / reception.
In FIG. 3, the horizontal axis represents frequency. In the example shown in FIG. 3, the number of CCs used is three. Of the three, one is a PCC in the band A1 used for communication between the eNB 12 and the UE 14. The other two are SCCs used for communication between the HeNB 13-1 and the UE. The two SCC bands are bands B1 and C1.

(Physical signal / physical channel)
Next, physical signals and physical channels related to CA will be described.
In the communication system 1a, physical signals and physical channels are used in data transmission (downlink) from the base station apparatus to the UE 14 and data transmission (uplink) from the UE 14 to the base station apparatus. The physical signal is a signal used for system synchronization, cell identification, and radio channel prediction. A physical channel is a channel for transmitting information generated at a higher layer (upper layer) than the physical layer. Signals and physical signals assigned to physical channels are assigned to predetermined times and frequencies as part of transmission signals or reception signals. This assignment is called mapping. Also, reconstructing the original signal from the assigned signal is called demapping.

The downlink physical channels include, for example, a physical downlink shared channel (PDSCH, Physical Downlink Shared Channel) and a physical downlink control channel (PDCCH, Physical Downing Control Channel) shared by each UE. The PDSCH is a channel that transmits user data representing information transmitted and received by a user, for example. The PDCCH includes, for example, identification information (ID) of a UE that performs communication using PDSCH, information on the transport (transmission) format of user data (ie, downlink scheduling information), a physical uplink shared channel (PUSCH, Physical Up and Shared Channel). ) Is used to transmit control information such as the ID of a UE that performs communication using the user ID and information on the transport (transmission) format of user data (uplink scheduling grant).

The PDCCH is also called a downlink L1 / L2 control channel (Downlink L1 / L2 Control Channel). The downlink scheduling information and the uplink scheduling grant are also called downlink control information (DCI, Downlink Control Information). Other physical downlink channels include physical broadcast channels (PBCH, Physical Broadcast Channel). The PBCH is a channel that transmits information (for example, system information) unique to each base station apparatus to UEs that are located in the cell, that is, within the coverage of the cell.

The downlink physical signal includes a synchronization signal (SS, Synchronization Signal). The synchronization signal is a signal used for searching (cell search) or identifying a base station apparatus in which UE 14 is located. The synchronization signal includes a cell ID that is information for identifying the base station apparatus. The synchronization signal includes a primary synchronization signal (PSS, Primary Synchronization Signal) and a secondary synchronization signal (SSS, Secondary Synchronization Signal).

The uplink physical channel includes a physical uplink shared channel (PUSCH, Physical Uplink Shared Channel) and a physical uplink control channel (PUCCH, Physical Uplink Control Channel) common to each UE. The PUSCH is a channel for transmitting user data, for example. The PUCCH is a channel that transmits, for example, downlink quality information (CQI, Channel Quality Indicator), PUSCH delivery confirmation information, etc. used for PUSCH scheduling, adaptive modulation / demodulation, and encoding processing (AMCS, Adaptive Modulation and Coding Scheme). is there.

Downlink quality information may be channel state information (CSI, Channel State Indicator) including CQI, PMI (Precoding Matrix Indicator), and RI (Rank Indicator). The acknowledgment information includes an acknowledgment signal (ACK, Acknowledgment) indicating that the transmission signal has been properly received or a negative acknowledgment signal (NACK, Negative Acknowledgment) indicating that the transmission signal has not been properly received. May be included.

The uplink physical signal includes a demodulation reference signal (DMRS, Demodulation Reference Signal). The demodulation reference signal is a signal used by the base station apparatus for synchronization with the UE 14.
In the communication system 1a, the above-described physical signals and physical channel signals may be collected and transmitted in one CC for each pair of one base station device and one UE, or when CA is performed. May be distributed and transmitted to a plurality of CCs for each pair.

(System configuration)
Next, the configuration of the communication system 1a will be described.
FIG. 4 is a schematic diagram showing the configuration of the communication system 1a according to the first embodiment.
The communication system 1a includes an eNB 12, a HeNB 13, a UE 14, an MME (Mobility Management Entity) 15 and a RAN (Radio Access Network, radio access network) 11.

The RAN 11 is a network that connects at least one of the eNB 12 or the HeNB 13 and the UE 14 by radio (for example, RRC [Radio Resource Control] connection).
The eNB 12 and the HeNB 13 are each connected to the MME 15 by wire. The HeNB 13 may be connected to the MME 15 using, for example, a wired subscriber communication line such as an optical communication line or a fixed telephone line. Part or all of the HeNB 13 may be connected to the MME 15 via, for example, a HeNB-GW (indoor base station apparatus gateway apparatus).

The MME 15 includes base station identification information (for example, PCI), which is identification information for each base station apparatus, and registration area information (for example, TAI (Tracking Area Identity)) representing a registration area including cells of a plurality of base station apparatuses. It is stored in association with each other in advance. Since the cells 33-1 to 33-3 are all included in the cell 32, the HeNBs 13-1 to 13-3 all belong to the registration area identified by the same TAI as that of the eNB 12. When any of the HeNBs 13-1 to 13-3 is a CSG cell or a hybrid cell, the MME 15 stores a CSG-ID representing a CSG group including the HeNB related to the cell in association with the PCI of the cell. ing.

The MME 15 receives a registration request signal from the UE 14 via a base station device (for example, eNB 12 or HeNB 13-1) corresponding to the stored PCI. The registration request signal is a signal indicating that the UE 14 registers as a device located in the cell of the base station device. Thereafter, the MME 15 generates communication path information (also called a bearer or a bearer) between the base station device and the counterpart device. The MME 15 transmits a registration confirmation signal to the base station apparatus (for example, the eNB 12 or the HeNB 13-1) that has received the registration request signal.

The MME 15 receives a communication path setting request signal from a base station apparatus (for example, the HeNB 13-1 or the eNB 12) corresponding to the stored PCI. The communication path setting request signal is a request for setting a communication path between the base station apparatus (or designated base station apparatus) and the counterpart apparatus in order to perform communication between the UE 14 and the counterpart apparatus. It is a signal showing. Thereafter, the MME 15 generates communication path information between the base station apparatus and the counterpart apparatus related to the communication path setting request signal. The MME 15 transmits a communication path setting confirmation signal to the base station apparatus (for example, the HeNB 13-1 or the eNB 12) that has received the communication path setting request signal.

Thereby, the base station apparatus transmits and receives user data between the UE 14 and the counterpart apparatus via the communication path represented by the generated communication path information. However, when the base station apparatus that transmitted the registration request signal or the communication path setting request signal is a CSG cell, the MME 15 determines whether or not the UE 14 belongs to the CSG group corresponding to the CSG cell. The MME 15 generates the above-described communication path information when the UE 14 belongs to the CSG group, and does not generate the above-described communication path information when the UE 14 does not belong to the CSG group. Thereby, a CSG cell implement | achieves communication by UE which belongs to a CSG group, and a CSG cell refuses communication by UE which belongs to a CSG group. Further, the hybrid cell realizes communication by UEs belonging to the CSG group of the cell using parameters dedicated to the CSG group. The hybrid cell realizes communication by UEs not belonging to the CSG group of the cell using other parameters.

(UE configuration)
Next, the configuration of the UE 14 according to the first embodiment will be described.
FIG. 5 is a schematic diagram illustrating the configuration of the UE 14 according to the first embodiment. The UE 14 shown in FIG. 5 corresponds to the UE 14 in FIG.
The UE 14 includes a transmission / reception unit 141, a communication control unit 142, and a data processing unit 143.

The transmission / reception unit 141 includes an antenna unit 1411, a wireless reception unit 1412, a demodulation unit 1413, a modulation unit 1414, and a wireless transmission unit 1415.

The antenna unit 1411 outputs a reception signal (radio frequency reception signal) in a radio frequency band received from at least one of the eNB 12 and the HeNBs 13-1 to 13-3 to the radio reception unit 1412. The antenna unit 1411 transmits the radio frequency band transmission signal (radio frequency transmission signal) input from the radio transmission unit 1415 as a radio wave to the eNB 12 and the HeNBs 13-1 to 13-3.

The radio reception unit 1412 down-converts the radio frequency reception signal input from the antenna unit 1411 to a base frequency band (baseband) and generates a modulation reception signal. When the radio reception unit 1412 generates a modulated reception signal, the radio reception unit 1412 performs down-conversion so that the center frequency becomes a base frequency (for example, 0 Hz) for each band represented by the CC information input from the communication control unit 142. This CC information represents a downlink CC that receives a signal from the base station apparatus.
The radio reception unit 1412 outputs the modulated reception signal generated for each CC to the demodulation unit 1413.

The demodulator 1413 demodulates the modulated received signal input from the radio receiver 1412 (for example, CP (Cyclic Prefix) removal, serial-parallel conversion, FFT (Fast Fourier Transform, Fast Fourier Transform), demapping, parallel-serial conversion) Then, a reception signal is generated. The demodulator 1413 outputs the generated received signal to the communication controller 142 and the data processor 143. In demapping, the demodulator 1413 extracts allocation data determined for each signal included in a physical channel (for example, PDSCH, etc.) and for each type of physical signal (for example, user data signal, control signal, etc.). The received data is reconstructed by permuting the extracted data.

The modulation unit 1414 modulates the transmission signal input from the communication control unit 142 and the data processing unit 143 (for example, serial-parallel conversion, mapping, IFFT (Inverse Fast Fourier Transform), parallel-serial conversion, CP insertion) ) To generate a modulated transmission signal. In the mapping, the modulation unit 1414 arranges data on the basis of an assignment determined for each signal included in a physical channel (for example, PUSCH and the like) and each type of physical signal (for example, user data and the like). Modulation section 1414 generates a modulated transmission signal for each base station apparatus and frequency band represented by the CC information input from communication control section 142, and outputs the generated modulated transmission signal to radio transmission section 1415.

Radio transmission section 1415 upconverts the modulated transmission signal input from modulation section 1414 from the base frequency band to the radio frequency band, and generates a radio frequency transmission signal. When generating a modulated transmission signal, the wireless transmission unit 1415 up-converts the center frequency from the base frequency to the center frequency of the band for each band represented by the CC information input from the communication control unit 142. This CC information represents an uplink CC that transmits a signal to the base station apparatus.
Radio transmission section 1415 outputs the generated radio frequency transmission signal to antenna section 1411.

The communication control unit 142 includes a communication measurement unit 1421, a synchronization processing unit 1422, and a bandwidth management unit 1423.

The communication measurement unit 1421 measures the communication amount and communication quality related to communication with the base station apparatus (for example, eNB 12) based on the received signal input from the demodulation unit 1413. For example, the communication measuring unit 1421 calculates the amount of information (communication amount) per unit time (for example, 10 ms) of the received signal.
The communication measuring unit 1421 determines whether the calculated communication amount is greater than a predetermined communication amount (for example, r times the communication amount that can be transmitted by the CC being used, where r is a positive real number smaller than 1). Judge. When it is determined that the communication amount is larger than the predetermined communication amount, the communication measurement unit 1421 generates a CA determination signal indicating that it is determined that CA is required, and outputs the generated CA determination signal to the synchronization processing unit 1422. .

The communication measurement unit 1421 extracts a synchronization signal from the received signal received from the base station apparatus (for example, in the frequency band A1 from the eNB 12), and generates quality information based on the extracted synchronization signal. The quality information includes, for example, information indicating a signal-to-interference noise ratio (SINR, Signal to Interference Ratio). The communication measurement unit 1421 outputs the generated quality information to the modulation unit 1414 as a transmission signal to the connected base station apparatus.

The synchronization processing unit 1422 extracts a synchronization signal from the received signal input from the demodulation unit 1413, and detects the HeNB 13 in which the UE 14 is in the cell and can use a new CC based on the extracted synchronization signal. The new CC is a CC different from the CC (for example, the band A1) used for transmitting and receiving user data with the communicating base station apparatus. Here, the synchronization processing unit 1422 determines that the base station identification information (cell ID) represented by the extracted synchronization signal is base station identification information representing one of the HeNBs 13 (for example, the HeNB 13-1) (HeNB search). Cell search).

The synchronization processor 1422 extracts system information from the received signal input from the demodulator 1413. The synchronization processing unit 1422 reads, as a new CC (for example, band B1), a CC that is not used for transmission / reception among CCs related to any HeNB 13 from the extracted system information (band detection). Hereinafter, description may be made assuming that the new CC is the band B1 and the HeNB 13 that can use the CC is the HeNB 13-1. In the first embodiment, the new CC may be a band other than the band B1, and the HeNB 13 related to the CC is not limited to the HeNB 13-1.

The synchronization processing unit 1422 generates CA request information indicating that the HeNB 13-1 that can use the CC of the new band B1 requests CA. The synchronization processing unit 1422 outputs the CA request information to the modulation unit 1314 as a transmission signal to the eNB 12.
The synchronization processing unit 1422 may generate a PI (Proximity Indicator) as an example of CA request information. The PI is information (location information) indicating that the UE 14 is located in the cell 33-1 of the HeNB 13-1 that performs communication using the CC of the band B1, for example. The PI generated by the synchronization processing unit 1422 is, for example, entering proximity indication, that is, information indicating that the UE 14 has entered the cell 33-1. The synchronization processing unit 1422 outputs the generated PI to the modulation unit 1414 as a transmission signal to the eNB 12.

The synchronization processing unit 1422 performs a synchronization process with the HeNB 13-1 when the CA preparation notification information is input from the demodulation unit 1413 as a received signal in the band B1 from the HeNB 13-1. The CA preparation notification information is information for notifying that the eNB 12 and the HeNB 13-1 perform processing related to CA preparation. In the synchronization processing, the synchronization processing unit 1422 detects, for example, the PSS from the synchronization signal received in the band B1, and detects the relative position (offset amount) of the SSS from the PSS. The synchronization processing unit 1422 detects the SSS at the detected position, and identifies the range of each frame in the received signal from the HeNB 13-1, that is, the frame timing, based on the detected SSS position. After completing the synchronization process, the synchronization processing unit 1422 generates CA preparation confirmation information (ACK), and outputs the generated CA preparation confirmation information to the modulation unit 1414 as a transmission signal to the HeNB 13-1. The CA preparation confirmation information is information indicating that reception of CA preparation notification information has been confirmed. The synchronization processing unit 1422 generates a synchronization processing completion signal indicating that the synchronization processing has been completed for the band B1, and outputs the generated synchronization processing completion signal to the band management unit 1423.

Band management unit 1423 generates CC information indicating a band for communicating with the base station apparatus. Band management section 1423 outputs CC information related to the downlink to radio reception section 1412, and outputs CC information related to the uplink to radio transmission section 1415. Here, the bandwidth management unit 1423 generates CC information representing the bandwidth B1 to the HeNB 13-1 based on the synchronization processing completion signal input from the synchronization processing unit 1422. Band management section 1423 outputs the generated CC information to radio reception section 1412 and radio transmission section 1415. As a result, the UE 14 can receive user data from the HeNB 13-1 using the CC of the band B1 and transmit the user data to the HeNB 13-1. The band management unit 1423 generates CA start information indicating that CA to the HeNB 13-1 has started using the CC of the band B1. Band management section 1423 outputs CA start information generated as a transmission signal to eNB 12 to modulation section 1414.

The data processing unit 143 is a processing unit that performs processing on user data. The data processing unit 143 executes applications such as voice communication and data communication, for example. The data processing unit 143 extracts reception user data from the reception signal input from the demodulation unit 1413, and performs processing related to the extracted reception user data. The data processing unit 143 outputs the transmission user data to the modulation unit 1414 as a transmission signal.

(Configuration of eNB)
Next, the configuration of the eNB 12 according to the first embodiment will be described.
FIG. 6 is a schematic diagram illustrating the configuration of the eNB 12a according to the first embodiment. The eNB 12a illustrated in FIG. 6 corresponds to the eNB 12 illustrated in FIG.
The eNB 12a includes a transmission / reception unit 121, a communication control unit 122, and a data processing unit 123.

The transmission / reception unit 121 includes an antenna unit 1211, a wireless reception unit 1212, a demodulation unit 1213, a modulation unit 1214, and a wireless transmission unit 1215.

The antenna unit 1211 outputs the radio frequency reception signal received from the UE 14 to the radio reception unit 1212. The antenna unit 1211 transmits the radio frequency transmission signal input from the radio transmission unit 1215 to the UE 14 as a radio wave.
The radio reception unit 1212 generates a modulated reception signal by down-converting the radio frequency reception signal input from the antenna unit 1211 to the base frequency band. The processing performed by the wireless reception unit 1212 is the same as the processing performed by the wireless reception unit 1412. Radio reception section 1212 outputs the generated modulated reception signal to demodulation section 1213.
The demodulation unit 1213 demodulates the modulated reception signal input from the wireless reception unit 1212 to generate a reception signal. The demodulation unit 1213 outputs the generated reception signal to the communication control unit 122 and the data processing unit 123. The processing performed by the demodulation unit 1213 is the same as that of the demodulation unit 1413.

The modulation unit 1214 modulates the transmission signal input from the communication control unit 122 and the data processing unit 123 to generate a modulated transmission signal. The process performed by the modulation unit 1214 is the same as that of the modulation unit 1414. Modulation section 1214 outputs the generated modulated transmission signal to radio transmission section 1215.
The radio transmission unit 1215 generates a radio frequency transmission signal by up-converting the modulated transmission signal input from the modulation unit 1214 from the base frequency band to the radio frequency band. The process performed by the wireless transmission unit 1215 is the same as that of the wireless transmission unit 1415. Radio transmission section 1215 outputs the generated radio frequency transmission signal to antenna section 1211.

In addition, the transmission / reception part 121 transmits the transmission signal to HeNB13 or MME15 input from the communication control part 122 or the data processing part 123 to HeNB13 or MME15 by wire (not shown). The transmission / reception unit 121 outputs a reception signal received by wire from the HeNB 13 or the MME 15 to the communication control unit 122 or the data processing unit 123 (not shown).

The communication control unit 122 includes a preparation processing unit 1221 and a bandwidth management unit 1222.
When the CA request information is input from the demodulation unit 1213 as a received signal from the UE 14, the preparation processing unit 1221 uses the CC (for example, the band B1) indicated by the CA request information to communicate with the UE 14 (for example, the HeNB 13). CA preparation processing with HeNB13-1). The preparation processing unit 1221 transmits and receives a communication path setting request signal for requesting setting of a communication path between the HeNB 13 (for example, HeNB 13-1) represented by the input CA request signal and the counterpart apparatus as a transmission signal to the MME 15. Output to the unit 121. The preparation processing unit 1221 receives a communication path setting confirmation signal corresponding to the communication path setting request signal output from the transmission / reception unit 121 as a reception signal from the MME 15. The preparation processing unit 1221 outputs, to the transmission / reception unit 121, CA preparation notification information for notifying that processing related to preparation for performing communication with the UE 14 using the CC is performed as a transmission signal to the HeNB 13. The preparation processing unit 1221 receives CA start information from the demodulation unit 1213 as a reception signal from the UE 14.

Note that the preparation processing unit 1221 may receive CA preparation confirmation information from the HeNB 13 (for example, HeNB 13-1) from the demodulation unit 1213 instead of inputting the CA start information from the UE. The CA preparation confirmation information is information indicating that the CA preparation process has been completed. When the CA preparation confirmation information is input, the preparation processing unit 1221 generates CA start information, and outputs the generated CA start information to the modulation unit 1214 as a transmission signal to the UE 14. Thereby, eNB12a transmits CA start information to UE14.

The band management unit 1222 generates CC information indicating a band for communicating with the UE 14. The bandwidth management unit 1222 outputs downlink CC information to the radio transmission unit 1215 and transmits uplink CC information to the radio reception unit 1212. For example, when communication is performed by transmitting user data to the UE 14 in the band A1, the band management unit 1222 generates CC information representing the band A1 to the UE 14. Band management unit 1222 outputs the generated CC information to radio transmission unit 1215.

The data processing unit 123 is a processing unit that performs processing on user data. For example, the data processing unit 123 extracts received user data from the received signal input from the demodulation unit 1213 and transmits the extracted received user data to the counterpart device via the transmission / reception unit 121. The data processing unit 123 outputs the user data received from the counterpart device to the modulation unit 1214 as a transmission signal.

(Configuration of HeNB)
Next, the configuration of the HeNB 13a according to the first embodiment will be described.
FIG. 7 is a schematic diagram illustrating the configuration of the HeNB 13a according to the first embodiment. The HeNB 13a illustrated in FIG. 7 corresponds to the HeNBs 13-1, 13-2, and 13-3 illustrated in FIG.
The HeNB 13a includes a transmission / reception unit 131, a communication control unit 132, and a data processing unit 133.

The transmission / reception unit 131 includes an antenna unit 1311, a wireless reception unit 1312, a demodulation unit 1313, a modulation unit 1314, and a wireless transmission unit 1315.
The configuration and processing of the antenna unit 1311, the wireless reception unit 1312, the demodulation unit 1313, the modulation unit 1314, and the wireless transmission unit 1315 are the same as the above-described antenna unit 1211, wireless reception unit 1212, demodulation unit 1213, modulation unit 1214, and wireless transmission. The configuration and processing of the unit 1215 are the same.
The configuration and processing of the data processing unit 133 are the same as the configuration and processing of the data processing unit 123 described above.

The communication control unit 132 includes a preparation processing unit 1321, a synchronization processing unit 1322, and a bandwidth management unit 1323.

CA preparation notification information is input from the demodulation unit 1313 to the preparation processing unit 1321 as a received signal from the eNB 12a. The preparation processing unit 1321 outputs the input CA preparation notification information to the modulation unit 1314 as a transmission signal in the band B1 to the synchronization processing unit 1322 and the UE 14. The preparation processing unit 1321 receives CA preparation confirmation information as a received signal from the UE 14 from the demodulation unit 1313 and outputs the input CA preparation confirmation information to the band management unit 1323.
Note that the preparation processing unit 1321 outputs a communication path setting request signal for requesting setting of a communication path between the own device (HeNB 13a) and the counterpart device to the transmission / reception unit 131 as a transmission signal to the MME 15. Good. In this case, after the communication path setting confirmation signal is input as the reception signal from the MME 15 from the transmission / reception unit 131, the CA preparation notification information is output. In this case, the preparation processing unit 1221 of the eNB 12a may omit the process of outputting the communication path setting confirmation signal.

The synchronization processing unit 1322 performs synchronization processing with the UE 14 after the CA preparation notification information is input from the preparation processing unit 1321. The band related to the synchronization process is a CC (for example, band B1) represented by the CA preparation notification information. The synchronization processing unit 1322 receives the reception signal from the UE 14 received using the CC from the demodulation unit 1213 and extracts the DMRS from the input reception signal. The synchronization processing unit 1322 calculates a delay time that takes the maximum value (peak value) of the cross-correlation between the DMRS stored in advance and the extracted DMRS. The synchronization processing unit 1322 identifies the range of each frame in the received signal from the UE 14, that is, the frame timing, based on the calculated delay time. After the synchronization processing is completed, the synchronization processing unit 1322 outputs a synchronization processing completion signal indicating that the synchronization processing is completed to the band management unit 1323.

The band management unit 1323 generates CC information representing a band for communicating with the UE 14 after the synchronization processing completion signal is input from the synchronization processing unit 1322. The bandwidth management unit 1323 outputs CC information related to the downlink to the radio transmission unit 1315 and transmits CC information related to the uplink to the radio reception unit 1312. The band management unit 1323 generates CC information represented by the CA preparation confirmation information input from the preparation processing unit 1321 (for example, the band B1 to the UE 14). Band management section 1323 outputs the generated CC information to radio transmission section 1315. Thereby, HeNB13a can transmit user data to UE14 using CC of band B1, and can receive from UE14 now.

The data processing unit 133 is a processing unit that performs processing on user data. The configuration and processing of the data processing unit 133 are the same as those of the data processing unit 123.

(CA processing sequence)
Next, communication processing according to the first embodiment will be described.
FIG. 8 is a sequence diagram illustrating communication processing according to the first embodiment.
Here, communication is initially performed between the eNB 12a and the UE 14 using the CC of the band A1 as the PCC. FIG. 8 shows a process until communication is performed between the HeNB 13-1 and the UE 14 using the CC of the band B1 as the SCC.
Hereinafter, transmission / reception of information between each base station apparatus and the UE will be mainly described, and processing of the transmission / reception unit 121 and the like will be omitted.

(Step S101a) The communication measurement unit 1421 of the UE 14 measures the communication amount of the received signal from the eNB 12, and determines whether or not CA is necessary based on the measured communication amount.
When it is determined that the CA is necessary, the synchronization processing unit 1422 of the UE 14 searches for the HeNB 13 that is different from the band A1 and can use the CC of the unused band B1, based on the synchronization signal included in the received signal from the HeNB 13. To do. Thereafter, the process proceeds to step S102a.

(Step S102a) The synchronization processing unit 1422 of the UE 14 generates a PI as CA request information for the HeNB 13 (HeNB 13-1 in the example of FIG. 8) detected in Step S101a, and uses the generated PI using the CC of the band A1. It transmits to eNB12. Thereafter, the process proceeds to step S103a.

(Step S103a) After receiving the CA request information from the UE 14, the preparation processing unit 1221 of the eNB 12 performs CA preparation processing. For example, the preparation processing unit 1221 transmits to the MME 15 a communication path setting request signal indicating that a communication path between the HeNB 13-1 represented by the received CA request information and the counterpart device is set. After receiving the communication path setting request signal from the MME 15, the preparation processing unit 1221 transmits CA preparation notification information to the HeNB 13-1. Thereafter, the process proceeds to step S104a.

(Step S104a) The preparation processing unit 1321 of the HeNB 13-1 transmits the CA preparation notification information received from the eNB 12 to the UE 14 using the CC of the band B1. Thereafter, the process proceeds to step S105a.

(Step S105a) After receiving the CA preparation notification information from the HeNB 13-1, the synchronization processing unit 1422 of the UE 14 performs synchronization processing on the CC in the band B1 with the HeNB 13-1. After the CA preparation notification information is input from the preparation processing unit 1321, the synchronization processing unit 1322 of the HeNB 13-1 performs synchronization processing on the CC in the band B 1 with the UE 14. Thereafter, the process proceeds to step S106a.

(Step S106a) The synchronization processing unit 1422 of the UE 14 generates CA preparation confirmation information (ACK), and transmits the generated CA preparation confirmation information to the HeNB 13-1. The band management unit 1323 of the HeNB 13-1 generates CC information indicating the band B1 to the UE 14, and outputs the generated CC information to the radio reception unit 1412 and the radio transmission unit 1415. Thereafter, the process proceeds to step S107a.

(Step S107a) The band management unit 1423 of the UE 14 generates CC information indicating the band B1 to the HeNB 13-1, and outputs the generated CC information to the radio reception unit 1412 and the radio transmission unit 1415. The band management unit 1423 of the UE 14 generates CA start information indicating that CA with the HeNB 13-1 has started using the CC of the band B1, and transmits the generated CA start information to the eNB 12 using the CC of the band A1. To do. Thereafter, the process proceeds to step S108a.

(Step S108a) The HeNB 13-1 and the UE 14 start communication using the CC of the band B1. That is, the UE 14 receives user data from the counterpart device as a reception signal via the HeNB 13-1 using the CC of the band B1, and transmits user data to the counterpart device as a transmission signal. Thereafter, the process ends.

Next, the HeNB search process in step S101a described above will be described.
FIG. 9 is a flowchart showing the HeNB search process according to the first embodiment.

(Step S1011a) The communication measurement unit 1421 of the UE 14 measures the communication amount with the eNB 12 based on the received signal input from the demodulation unit 1413. Thereafter, the process proceeds to step S1012a.

(Step S1012a) The communication measuring unit 1421 determines whether or not CA is necessary based on the measured communication volume. For example, when the measured communication volume is larger than the predetermined communication volume, the communication measurement unit 1421 determines that CA is required. The communication measuring unit 1421 determines that the CA is unnecessary when the measured communication volume is equal to or smaller than the predetermined communication volume. When it is determined that CA is required (step S1012a Y), the process proceeds to step S1013a. If it is determined that the CA is not necessary (step S1012a N), the process ends.

(Step S1013a) The synchronization processing unit 1422 extracts a synchronization signal from the reception signal received from the HeNB 13-1. Based on the extracted synchronization signal, the synchronization processing unit 1422 searches for a HeNB 13 that has a cell where the UE 14 is located and can use a new CC. When a HeNB 13 that can use a new CC has been detected (step S1013a Y), the process proceeds to step S102a (see FIG. 8). When a HeNB 13 that can use a new CC cannot be detected (step S1013a N), the process is terminated.

In the synchronization processing unit 1422, the number of times of performing processing (HeNB search) for detecting the HeNB 13 that can use a new CC is not limited to one. The synchronization processing unit 1422 may repeat the HeNB search until the HeNB 13 is found. However, if the HeNB is not found even after repeating the HeNB search for a predetermined number of times (for example, three times) or for a predetermined time (for example, 30 seconds), the synchronization processing unit 1422 implements CA. Judge that it is not possible. When it is determined that CA cannot be realized, the synchronization processing unit 1422 may repeat the HeNB search after a predetermined time (for example, 180 seconds) has elapsed. Further, the synchronization processing unit 1422 may repeat the HeNB search at a predetermined time interval (for example, 180 seconds). Further, the synchronization processing unit 1422 may stop the HeNB search and output CA impossible information (NACK) to the modulation unit 1414 as a transmission signal to the eNB 12. Note that the synchronization processing unit 1422 may stop the HeNB search when the communication amount measured by the communication measurement unit 1421 does not exceed a predetermined communication amount. In that case, the synchronization processing unit 1422 may not output the CA impossibility information.

(Modification 1-1)
Next, a modification of the first embodiment will be described.
In the modified example 1-1, the synchronization processing unit 1422 of the UE 14 represents requesting CA with the HeNB 13-1, and generates CA request information (CA request command) represented by a command in a specific format.

FIG. 10 is a sequence diagram illustrating a modification of the communication process according to the first embodiment.
The communication process shown in FIG. 10 is common to the communication process shown in FIG. 8 in that it includes steps S101a and S103a to S108a. However, the communication process illustrated in FIG. 10 includes step S202a instead of step S102a included in the communication process illustrated in FIG. Here, step S202a is executed after step S101a.

(Step S202a) The synchronization processing unit 1422 of the UE 14 generates CA request information for the HeNB 13-1 discovered in Step S101a and represented by a command in a specific format. The synchronization processing unit 1422 transmits the generated CA request information to the eNB 12 using the CC of the band A1. Thereafter, the process proceeds to step S103a.

(Modification 1-2)
Next, another modification according to the first embodiment will be described.
In Modification 1-2, the CA request information generated by the synchronization processing unit 1422 of the UE 14 is added to other command information and transmitted to the eNB 12. The other command information is, for example, quality information generated by the communication measuring unit 1421. The communication measuring unit 1421 may include communication amount information representing the calculated communication amount in the generated quality information. When the CA request signal is input from the synchronization processing unit 1422, the communication measurement unit 1421 adds the CA request signal to the quality information and outputs it to the modulation unit 1414 as an output signal to the eNB 12.

FIG. 11 is a sequence diagram illustrating another modified example of the communication process according to the first embodiment.
The communication process shown in FIG. 11 includes steps S101a, S302a, and S103a-S108a. The communication process in FIG. 11 is common to the communication process shown in FIG. 8 in that it includes steps S101a and S103a to S108a. However, the communication process illustrated in FIG. 11 includes step S302a instead of step S102a included in the communication process illustrated in FIG. Here, step S302a is executed after step S101a.

(Step S302a) The synchronization processing unit 1422 of the UE 14 generates CA request information indicating that a CA with the HeNB 13-1 detected in Step S101a is requested, and outputs the generated CA request information to the communication measurement unit 1421. The communication measurement unit 1421 adds the CA request information input from the synchronization processing unit 1422 as a part of the quality information (another command). The communication measurement unit 1421 transmits the CA request information added as part of the quality information to the eNB 12. Thereafter, the process proceeds to step S103a.
In step S103a, the preparation processing unit 1221 of the eNB 12 extracts CA request information from the quality information received from the UE 14.

(Modification 1-3)
Next, another modification according to the first embodiment will be described.
In Modification 1-3, when the synchronization processing unit 1422 of the UE 14 detects a plurality of HeNBs 13 that can use a new CC, one of the detected plurality of HeNBs 13 (for example, the band B1 and the HeNB 13-1) select. The synchronization processing unit 1422 receives, for example, the quality information received from each HeNB 13 from the communication measurement unit 1421, and selects the HeNB 13 (best cell) of the CC having the highest communication quality represented by the input quality information. The synchronization processing unit 1422 generates CA request information for the HeNB 13 of the selected CC, and outputs the generated CA request information to the modulation unit 1414 as a transmission signal to the HeNB 13.

FIG. 12 is a sequence diagram illustrating another modified example of the communication process according to the first embodiment.
The communication process shown in FIG. 12 includes steps S101a, S401a, and S102a-S108a. The communication process of FIG. 12 is common to the communication process shown in FIG. 8 in that it includes steps S101a to S108a. However, in the communication process of FIG. 12, step S401a is executed after step S101a.

(Step S401a) When a plurality of HeNBs 13 that can use a new CC are detected, the synchronization processing unit 1422 has one HeNB 13 (band B1, HeNB 13-1 in the example of FIG. 12) having the highest communication quality. select. For example, the quality information received from each HeNB 13 from the communication measurement unit 1421 is input to the synchronization processing unit 1422, and the HeNB 13-1 of the CC having the highest communication quality represented by the input quality information is selected as the best cell. Thereafter, the process proceeds to step S102a.
In step S102a, the synchronization processing unit 1422 generates the PI of the best cell as CA request information, and transmits the generated PI to the eNB 12.

In the first embodiment, a case has been described as an example where the UE 14 determines whether or not CA is necessary based on the information amount of the downlink received signal and performs CA for both the downlink and the uplink. In 1st Embodiment, it is not restricted to this, You may perform CA only for a downlink.
In the first embodiment, the UE 14 may determine whether the CA is necessary based on the uplink traffic. Here, the communication measurement unit 1421 performs communication with the connection destination base station apparatus (for example, the eNB 12) based on the transmission signal input from the data processing unit 143 instead of the reception signal input from the demodulation unit 1413. The uplink traffic is calculated. In this case, CA may be performed only for the uplink.

Note that the UE 14 may determine whether or not the CA is necessary based on the total communication amount of the uplink communication amount and the downlink communication amount. Here, the communication measurement unit 1421 calculates the total communication amount by adding the downlink communication amount and the uplink communication amount calculated by performing the above-described processing. The communication measuring unit 1421 determines whether or not the CA is necessary based on the calculated total communication amount.

As described above, the first embodiment relates to a communication system 1 a including the eNB 12, the HeNB 13 having a partial region of the cell 32 as the cell 33, and the UE 14. In the first embodiment, the UE 14 communicates with the eNB 12 using the frequency band A1, and the UE 14 includes CA request information indicating that the UE 14 requests communication with the HeNB 13 using the frequency band B1 different from the frequency band A1. Generate. The UE 14 transmits the generated request information to the eNB 12. Therefore, in the first embodiment, the UE 14 requests communication between the UE 14 and the HeNB 13-1 that can communicate in the frequency band B1 according to the communication status with the eNB 12 in the frequency band A1, and therefore, the frequency resource utilization efficiency is high. It does not decline.

(Second Embodiment)
Next, a second embodiment according to the present invention will be described. Portions having the same configuration and processing as those of the first embodiment are denoted by the same reference numerals.
The communication system 2 a according to the second embodiment relates to a communication system including the eNB 22, the HeNB 13 having a partial region of the cell 32 as the cell 33, and the UE 14. The eNB 22 communicates with the UE 14 using the band A1, generates CA request information indicating that communication between the HeNB 13 and the UE 14 is requested using the band B1 different from the band A1, and transmits the CA request information to the UE 14. .

FIG. 13 is a schematic diagram illustrating a communication system 2a according to the second embodiment.
The communication system 2a according to the second embodiment includes a RAN 11, an eNB 22, HeNBs 13-1 to 13-3, a UE 14, and an MME 15. That is, the communication system 2a is common to the communication system 1a (see FIG. 4) in that it includes the RAN 11, the HeNBs 13-1 to 13-3, the UE 14, and the MME 15. The communication system 2a differs from the communication system 1a in that an eNB 22 is provided instead of the eNB 12.

FIG. 14 is a schematic diagram illustrating the configuration of the eNB 22 according to the second embodiment. An eNB 22a illustrated in FIG. 14 corresponds to the eNB 12 illustrated in FIG.
The eNB 22 includes a transmission / reception unit 121, a communication control unit 222, and a data processing unit 123. The communication control unit 222 includes a communication measurement unit 2223 in addition to the preparation processing unit 1221 and the bandwidth management unit 1222.
The communication measurement unit 2223 determines whether or not CA is necessary based on the communication amount of the received signal received from the UE 14. The communication measurement unit 2223 measures the amount of communication related to communication using the CC in the frequency band A1 with the UE 14 as the connection destination based on the received signal input from the demodulation unit 1213. The communication measuring unit 2223 determines whether the calculated communication amount is larger than a predetermined communication amount.
When it is determined that the communication amount is larger than the predetermined communication amount, the communication measurement unit 2223 generates CA request information. The generated CA request information indicates that the eNB 22 requests communication between the HeNB 13 and the UE 14 using a CC in a new band B1 different from the CC band A1 used for communication with the UE 14. Such communication is related to transmission / reception of user data between the UE 14 and the counterpart device.
The communication measurement unit 2223 outputs the generated CA request information to the modulation unit 1214 as a transmission signal to the UE 14.

The CA request information is input from the demodulation unit 1413 to the synchronization processing unit 1422 of the UE 14 as a reception signal from the eNB 22. The synchronization processing unit 1422 executes the above-described HeNB search after the CA request information is input. After completing the HeNB search, the synchronization processing unit 1422 generates CA request confirmation information (ACK) indicating that the CA request information has been received, and transmits the generated CA request confirmation information to the modulation unit 1414 as a transmission signal to the eNB 22. Output.
Thereafter, CA request confirmation information is input from the demodulation unit 1213 to the preparation processing unit 1221 of the eNB 22 as a reception signal from the UE 14. Thereafter, the preparation processing unit 1221 performs the CA preparation processing described above.

Next, communication processing according to the second embodiment will be described.
FIG. 15 is a sequence diagram illustrating communication processing according to the second embodiment.
The communication process shown in FIG. 15 includes steps S501a, S101a, S502a, and S103a-S108a. The communication process of FIG. 15 is common to the communication process shown in FIG. 8 in that it includes steps S101a and S103a to S108a. However, step S101a is executed after step S501a, and step S502a is executed after step S101a.

(Step S501a) The communication measurement unit 2223 determines whether or not CA is necessary based on the communication amount of the received signal received from the UE 14. If the communication measurement unit 2223 determines that the communication amount is larger than the predetermined communication amount, the communication measurement unit 2223 generates CA request information and transmits the generated CA request information to the UE 14. Thereafter, the process proceeds to step S101a. In step S101a, the communication measurement unit 1421 of the UE 14 may omit the processing related to the measurement of communication traffic and the necessity determination of CA (see FIG. 9, steps S1011a and S1012a).

(Step S502a) The synchronization processing unit 1422 of the UE 14 generates CA request confirmation information after the HeNB search (see FIG. 9, step S1013a) is completed, and transmits the generated CA request confirmation information to the eNB 22. Thereafter, the preparation processing unit 1221 of the eNB 22 receives the CA request confirmation information from the UE 14, and proceeds to Step S103a.

In the second embodiment, as in Modification 1-3 of the first embodiment described above, in step S101a, when the synchronization processing unit 1422 detects a plurality of HeNBs 13 that can use a new CC, You may make it select one HeNB13 of CC with the highest communication quality.

In the second embodiment, the case where the eNB 22 determines whether the CA is necessary based on the information amount of the uplink received signal and performs CA for both the uplink and the downlink has been described as an example. In 2nd Embodiment, it is not restricted to this, You may perform CA only for an uplink.
In the second embodiment, the eNB 22 may determine whether or not CA is necessary based on the downlink traffic. Here, the communication measurement unit 2223 calculates the downlink communication amount related to the communication with the UE 14 as the connection destination based on the reception signal input from the data processing unit 123 instead of the reception signal input from the demodulation unit 1213. calculate. In this case, CA may be performed only for the downlink.
Note that the eNB 22 may determine whether the CA is necessary based on the total communication amount of the uplink communication amount and the downlink communication amount. Here, the communication measurement unit 2223 calculates the total communication amount by adding the downlink communication amount and the uplink communication amount calculated by performing the above-described processing. The communication measuring unit 2223 determines whether or not CA is necessary based on the calculated total traffic.

As described above, the second embodiment relates to a communication system 2 a including the eNB 22, the HeNB 13 whose partial area of the cell 32 is the cell 33, and the UE 14. In the second embodiment, the eNB 22 communicates with the UE 14 using the frequency band A1, and the eNB 22 requests the communication between the HeNB 13 and the UE 14 using the frequency band B1 different from the frequency band A1. Generate information. The eNB 22 transmits the generated CA request information to the UE 14. Therefore, in the second embodiment, the eNB 22 requests communication using the UE 14 and the frequency band B1 in accordance with the communication status with the UE 14 in the frequency band A1, so that the use efficiency of the frequency resource does not decrease.

(Third embodiment)
The third embodiment of the present invention will be described below with reference to the drawings.
Since the conceptual diagram showing the communication system 1b which concerns on 3rd Embodiment is the same as that of FIG. 1 which shows the conceptual diagram showing the communication system 1a which concerns on 1st Embodiment, the description is abbreviate | omitted.
Further, a schematic diagram showing the configuration of the communication system 1b according to the third embodiment is the same as FIG. 4 showing the schematic diagram showing the configuration of the communication system 1b according to the first embodiment, and thus the description thereof is omitted. To do.
Moreover, since the schematic diagram showing the structure of UE which concerns on 3rd Embodiment is the same as that of FIG. 5 which shows the schematic diagram showing the structure of UE which concerns on 1st Embodiment, the description is abbreviate | omitted.

16A and 16B are conceptual diagrams showing an example of a frequency band used for data transmission / reception. In both FIG. 16A and FIG. 16B, the horizontal axis represents frequency.
FIG. 16A shows that the HeNB 13-1 transmits data to the UE 14 using the PCC in the band B2 before the CA process. FIG. 16B shows that, after CA processing, the HeNB 13-1 transmits data to the UE 14 using the PCC (Primary Component Carrier) of the band B2 to the UE 14, and at the same time, the eNB 12 transmits an SCC (Secondary Component) of the band A2 to the UE 14. (Carrier, secondary component carrier) represents data transmission.

At this time, the UE 14 receives data from the same counterpart device (for example, another mobile station device) via the HeNB 13-1 and the eNB 12, respectively, using the band A2 and the band B2. Therefore, CA refers to virtually expanding the frequency band by simultaneously using a plurality of CCs for communication with the same counterpart device. CA may also refer to communication using an expanded frequency band. In the above example, the band used from the beginning before expanding the band between the HeNB (small base station apparatus) 13-1 and the UE (mobile station apparatus) 14 is the band B2 (first frequency band). is there. When extending the band, the newly added band between the eNB 12 (macrocell base station apparatus) and the UE 14 (mobile station apparatus) is the band A2 (second frequency band). That is, CA is to aggregate the band B2 (first frequency band) and the band A2 (second frequency band) and perform communication between the UE 14 and the counterpart device.

The CCs to be aggregated may be frequency bands that are separated from each other as shown in FIGS. 16A and 16B, or may be frequency bands that are adjacent to each other. The band of each CC may be any band (for example, any one of 800 MHz, 2.4 GHz, and 3.4 GHz). The bandwidth of each CC may be any bandwidth (for example, any of 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz). Further, the bandwidth and center frequency of each CC may be different between the uplink and the downlink.

Here, the PCC is a frequency band serving as a reference for measurement control such as reception quality performed by the UE 14, detection of a downlink radio link failure, and transmission of an uplink control channel, for example. The PCC is a main band assigned to each UE. The SCC is a frequency band assigned to the UE other than the PCC. System information to be described later may include information representing PCC and information representing SCC used for communication with the UE 14 for each base station apparatus.

The number of CCs to be aggregated is not limited to two, and may be an integer greater than one (for example, three). The number of SCCs is not limited to one, and may be an integer greater than one.
FIG. 17 is a conceptual diagram illustrating another example of a frequency band used for data transmission / reception. In FIG. 17, the horizontal axis represents frequency. In the example shown in FIG. 17, the number of CCs used is three. Of the three, one is a PCC in the band B2 used in communication between the HeNB 13-1 and the UE. The other two are SCCs used in communication between the eNB 12 and the UE 14. The bands of the two SCCs are bands A2 and C2.

The communication measurement unit 1421 measures the communication amount and communication quality related to communication with each connection destination base station device (for example, the HeNB 13-1) based on the received signal input from the demodulation unit 1413.
For example, the communication measuring unit 1421 calculates the amount of information (communication amount) per unit time (for example, 10 ms) of the received signal.
The communication measuring unit 1421 determines whether the calculated communication amount is greater than a predetermined communication amount (for example, r times the communication amount that can be transmitted by the CC being used, where r is a positive real number smaller than 1). Judge. When it is determined that the communication amount is larger than the predetermined communication amount, the communication measurement unit 1421 generates a CA determination signal indicating that it is determined that CA is required, and outputs the generated CA determination signal to the synchronization processing unit 1422. .

The communication measurement unit 1421 extracts a synchronization signal from the received signal received from the base station apparatus (for example, in the frequency band B2 from the HeNB 13-1), and generates quality information based on the extracted synchronization signal. The quality information includes, for example, information indicating a signal-to-interference noise ratio (SINR, Signal to Interference Ratio). The communication measurement unit 1421 outputs the generated quality information to the modulation unit 1414 as a transmission signal to the connected base station apparatus.

When the CA determination signal is input from the communication measurement unit 1421, the synchronization processing unit 1422 extracts the synchronization signal from the reception signal input from the demodulation unit 1413, and the UE 14 is located in the cell based on the extracted synchronization signal. The eNB 12 that can use the new CC is detected. The new CC is a CC different from the CC (for example, the band B2) used for transmitting and receiving user data with the communicating base station apparatus. Here, the synchronization processing unit 1422 determines that the base station identification information (cell ID) represented by the extracted synchronization signal is base station identification information representing the eNB 12 (eNB search, cell search). The synchronization processing unit 1422 extracts system information from the received signal input from the demodulation unit 1413. The synchronization processing unit 1422 reads a CC that is not used for transmission / reception among CCs related to the eNB among the extracted system information as a new CC (for example, the band A2) (band detection). Hereinafter, the description may be made assuming that the new CC is the band A2 and the eNB that can use the CC is the eNB 12. In the third embodiment, the new CC may be a band other than the band A2, and the eNB related to the CC is not limited to the eNB 12.

The synchronization processing unit 1422 generates CA request information indicating that a CA is requested to the eNB 12 that can use the CC of the new band A2. Synchronization processing section 1422 outputs CA request information to modulation section 1414 as a transmission signal to HeNB 13-1.
The synchronization processing unit 1422 may generate a PI (Proximity Indicator) as an example of CA request information. The PI is, for example, information (location information) indicating that the UE 14 is in the cell 32 of the eNB 12 that performs communication using the CC of the band A2. The PI generated by the synchronization processing unit 1422 is, for example, entering proximity indication, that is, information indicating that the UE 14 has entered the cell 32. Synchronization processing section 1422 outputs the generated PI to modulation section 1414 as a transmission signal to HeNB 13-1.

The synchronization processing unit 1422 performs synchronization processing with the eNB 12 when the CA preparation notification information is input from the demodulation unit 1413 as a reception signal in the band B2 from the HeNB 13-1. The CA preparation notification information is information for notifying that the HeNB 13-1 and the eNB 12 perform processing related to CA preparation. In the synchronization processing, the synchronization processing unit 1422 detects the PSS from the synchronization signal received in the band A2, for example, and detects the relative position (offset amount) of the SSS from the PSS. The synchronization processing unit 1422 detects the SSS at the detected position, and identifies the range of each frame in the received signal from the eNB 12, that is, the frame timing, based on the detected position of the SSS. After completing the synchronization process, the synchronization processing unit 1422 generates CA preparation confirmation information (ACK), and outputs the generated CA preparation confirmation information to the modulation unit 1414 as a transmission signal to the HeNB 13-1. The CA preparation confirmation information is information indicating that the CA preparation process has been completed. The synchronization processing unit 1422 generates a synchronization processing completion signal indicating that the synchronization processing has been completed for the band A2, and outputs the generated synchronization processing completion signal to the band management unit 1423.

Band management unit 1423 generates CC information indicating a band for communicating with the base station apparatus. Band management section 1423 outputs CC information related to the downlink to radio reception section 1412, and outputs CC information related to the uplink to radio transmission section 1415. Here, the bandwidth management unit 1423 generates CC information representing the bandwidth A2 to the eNB 12 based on the synchronization processing completion signal input from the synchronization processing unit 1422. Band management section 1423 outputs the generated CC information to radio reception section 1412 and radio transmission section 1415. Thereby, UE14 comes to be able to receive user data from eNB12 using CC of zone | band A2, and to transmit to eNB12. The band management unit 1423 generates CA start information indicating that CA to the eNB 12 has started using the CC of the band A2. Band management section 1423 outputs CA start information generated as a transmission signal to eNB 12 to modulation section 1414.

The data processing unit 143 is a processing unit that performs processing on user data. The data processing unit 143 executes applications such as voice communication and data communication, for example. The data processing unit 143 extracts reception user data from the reception signal input from the demodulation unit 1413, and performs processing related to the extracted reception user data. The data processing unit 143 outputs the transmission user data to the modulation unit 1414 as a transmission signal.

(Configuration of HeNB)
Next, the configuration of the HeNB 13 according to the third embodiment will be described.
FIG. 19 is a schematic diagram illustrating the configuration of the HeNB 13b according to the third embodiment. The HeNB 13b illustrated in FIG. 19 corresponds to the HeNBs 13-1, 13-2, and 13-3 illustrated in FIG.
The HeNB 13b includes a transmission / reception unit 131, a communication control unit 132, and a data processing unit 133.

The transmission / reception unit 131 includes an antenna unit 1311, a wireless reception unit 1312, a demodulation unit 1313, a modulation unit 1314, and a wireless transmission unit 1315.

The antenna unit 1311 outputs the radio frequency reception signal received from the UE 14 to the radio reception unit 1312. The antenna unit 1311 transmits the radio frequency transmission signal input from the radio transmission unit 1315 to the UE 14 as a radio wave.
The radio reception unit 1312 generates a modulated reception signal by down-converting the radio frequency reception signal input from the antenna unit 1311 to the base frequency band. The processing performed by the wireless reception unit 1312 is the same as the processing performed by the wireless reception unit 1412. The wireless reception unit 1312 outputs the generated modulated reception signal to the demodulation unit 1313.
The demodulation unit 1313 demodulates the modulated reception signal input from the wireless reception unit 1312 and generates a reception signal. The demodulation unit 1313 outputs the generated reception signal to the communication control unit 132 and the data processing unit 133. The processing performed by the demodulation unit 1313 is the same as that of the demodulation unit 1413.

The modulation unit 1314 modulates the transmission signal input from the communication control unit 132 and the data processing unit 133 to generate a modulated transmission signal. The process performed by the modulation unit 1314 is the same as that of the modulation unit 1414. Modulation section 1314 outputs the generated modulated transmission signal to radio transmission section 1315.
Radio transmission section 1315 upconverts the modulated transmission signal input from modulation section 1314 from the base frequency band to the radio frequency band, and generates a radio frequency transmission signal. The process performed by the wireless transmission unit 1315 is the same as that of the wireless transmission unit 1415. Radio transmission section 1315 outputs the generated radio frequency transmission signal to antenna section 1311.

The transmission / reception unit 131 transmits a transmission signal to the eNB 12 or the MME 15 input from the communication control unit 132 or the data processing unit 133 to the eNB 12 or the MME 15 through the backbone network (not shown). The transmission / reception unit 131 outputs a reception signal received from the eNB 12 or the MME 15 through the backbone network to the communication control unit 132 or the data processing unit 133 (not shown).

The communication control unit 132 includes a preparation processing unit 1321 and a bandwidth management unit 1322.
When the CA request information is input from the demodulation unit 1313 as a reception signal from the UE 14, the preparation processing unit 1321 communicates with the eNB 12 that communicates with the UE 14 using the CC (for example, the band A2) represented by the CA request information. CA preparation processing is performed between them. The preparation processing unit 1321 outputs a communication path setting request signal indicating that a communication path between the eNB 12 and the counterpart device is requested to the transmission / reception unit 131 as a transmission signal to the MME 15. The preparation processing unit 1321 identifies the eNB 12 using the CA request information.

To the preparation processing unit 1321, a communication path setting confirmation signal corresponding to the above-described communication path setting request signal is input from the transmission / reception unit 131 as a reception signal from the MME 15. Then, the preparation processing unit 1321 outputs the input CA request information to the transmission / reception unit 131 as a transmission signal to the eNB 12. The preparation processing unit 1321 receives, from the transmission / reception unit 131, the CA preparation notification information for notifying that processing related to preparation for performing communication with the UE 14 using the CC represented by the CA request information is performed. . The preparation processing unit 1321 outputs the input CA preparation notification information to the modulation unit 1314 as a transmission signal to the UE 14. The preparation processing unit 1321 receives CA preparation confirmation information from the demodulation unit 1313 as a reception signal from the UE 14.

The band management unit 1322 generates CC information indicating a band for communicating with the UE 14. The bandwidth management unit 1322 outputs downlink CC information to the radio transmission unit 1315 and transmits uplink CC information to the radio reception unit 1312. For example, when performing communication by transmitting user data to the UE 14 in the band B2, the band management unit 1322 generates CC information representing the band B2 to the UE 14. Band management section 1322 outputs the generated CC information to radio transmission section 1315.

The data processing unit 133 is a processing unit that performs processing on user data. For example, the data processing unit 133 extracts user data from the reception signal input from the demodulation unit 1313, and transmits the extracted user data to the counterpart device via the transmission / reception unit 131. The data processing unit 133 outputs user data received from the counterpart device to the modulation unit 1314 as a transmission signal.

(Configuration of eNB)
Next, the configuration of the eNB 12 according to the third embodiment will be described.
FIG. 20 is a schematic diagram illustrating the configuration of the eNB 12b according to the third embodiment. An eNB 12b illustrated in FIG. 20 corresponds to the eNB 12 illustrated in FIG.
The eNB 12b includes a transmission / reception unit 121, a communication control unit 122, and a data processing unit 123.

The transmission / reception unit 121 includes an antenna unit 1211, a wireless reception unit 1212, a demodulation unit 1213, a modulation unit 1214, and a wireless transmission unit 1215.
The configuration and processing of the antenna unit 1211, the wireless reception unit 1212, the demodulation unit 1213, the modulation unit 1214, and the wireless transmission unit 1215 are the same as the above-described antenna unit 1311, wireless reception unit 1312, demodulation unit 1313, modulation unit 1314, and wireless transmission. The configuration and processing of the unit 1315 are the same.
The configuration and processing of the data processing unit 123 are the same as the configuration and processing of the data processing unit 133 described above.

The communication control unit 122 includes a preparation processing unit 1221, a synchronization processing unit 1222, and a bandwidth management unit 1223.

CA request information is input from the demodulation unit 1213 to the preparation processing unit 1221 as a reception signal from the HeNB 13b. The preparation processing unit 1221 outputs the input CA request information to the synchronization processing unit 1222. Thereafter, the preparation processing unit 1221 generates CA preparation notification information, and outputs the generated CA preparation notification information to the modulation unit 1214 as a transmission signal to the HeNB 13b.
Note that the preparation processing unit 1221 outputs a communication path setting request signal for requesting setting of a communication path between the own apparatus (eNB 12b) and the counterpart apparatus to the transmission / reception unit 121 as a transmission signal to the MME 15. Good. In this case, after the communication path setting confirmation signal is input as the reception signal from the MME 15 from the transmission / reception unit 121, the CA request information and the CA preparation notification information are output. In this case, the preparation processing unit 1321 of the HeNB 13b may omit the process of outputting the communication path setting confirmation signal.

The synchronization processing unit 1222 performs synchronization processing with the UE 14 after the CA request information is input from the preparation processing unit 1221. The band related to the synchronization process is a CC (for example, band A2) represented by the CA request information. The synchronization processing unit 1222 receives the reception signal from the UE 14 received using the CC from the demodulation unit 1213 and extracts the DMRS from the input reception signal. The synchronization processing unit 1222 calculates a delay time that takes the maximum value (peak value) of the cross-correlation between the DMRS stored in advance and the extracted DMRS. The synchronization processing unit 1222 identifies the range of each frame in the received signal from the UE 14, that is, the frame timing, based on the calculated delay time. The synchronization processing unit 1222 outputs a synchronization processing completion signal indicating that the synchronization processing is completed to the band management unit 1223 after the synchronization processing is completed.

The bandwidth management unit 1223 generates CC information indicating a bandwidth for communicating with the UE 14. Band management section 1223 outputs CC information related to the downlink to radio transmission section 1215 and transmits CC information related to the uplink to radio reception section 1212. When CA start information is input from the demodulation unit 1213 as a received signal from the UE 14, the band management unit 1223 generates CC information represented by the CA start information (for example, the band A2 to the UE 14). The bandwidth management unit 1223 outputs the generated CC information to the wireless reception unit 1212 and the wireless transmission unit 1215. Thereby, eNB12b can transmit user data to UE14 using CC of zone | band A2, and can receive from UE14 now.

Note that the bandwidth management unit 1223 may generate CC information after the synchronization processing completion signal is input from the synchronization processing unit 1222, and output the generated CC information to the wireless reception unit 1212 and the wireless transmission unit 1215. In that case, the band management unit 1223 generates CA start information, and outputs the generated CA start information to the modulation unit 1214 as a transmission signal to the UE 14. Thereby, eNB12b transmits CA start information to UE14. In this case, the UE 14 can omit transmitting the CA start information to the eNB 12b.

The data processing unit 123 is a processing unit that performs processing on user data. The configuration and processing of the data processing unit 123 is the same as that of the data processing unit 133.

(CA processing sequence)
Next, communication processing according to the third embodiment will be described.
FIG. 21 is a sequence diagram illustrating communication processing according to the third embodiment.
Here, communication is initially performed between the HeNB 13-1 and the UE 14 using the CC of the band B2 as the PCC. FIG. 21 illustrates a process until communication is performed between the eNB 12 and the UE 14 using the CC of the band A2 as the SCC. Hereinafter, transmission / reception of information between each base station apparatus and the UE will be mainly described, and processing of the transmission / reception unit 121 and the like will be omitted.

(Step S101b) The communication measurement unit 1421 of the UE 14 measures the communication amount of the received signal from the HeNB 13-1, and determines whether the CA is necessary based on the measured communication amount. When it is determined that the CA is necessary, the synchronization processing unit 1422 of the UE 14 searches for an eNB that is different from the band B2 and can use the CC of the unused band A2 based on the synchronization signal included in the received signal from the eNB 12 To do. Thereafter, the process proceeds to step S102b.

(Step S102b) The synchronization processing unit 1422 of the UE 14 generates a PI as CA request information for the eNB 12 detected in Step S101b, and transmits the generated PI to the HeNB 13-1 using the CC of the band B2. Thereafter, the process proceeds to step S103b.

(Step S103b) The preparation processing unit 1321 of the HeNB 13-1 receives the CA request information from the UE 14, and then performs CA preparation processing. For example, the preparation processing unit 1321 transmits a communication path setting request signal indicating that a communication path between the eNB 12 and the counterpart apparatus represented by the received CA request information is set to the MME 15 (not shown). The preparation processing unit 1321 transmits the received CA request information to the eNB 12 after receiving the communication path setting confirmation signal from the MME 15.
The preparation processing unit 1221 of the eNB 12 outputs the CA request information received from the HeNB 13-1 to the synchronization processing unit 1222. The preparation processing unit 1221 generates CA preparation notification information and transmits the generated CA preparation notification information to the HeNB 13-1. Thereafter, the process proceeds to step S104b.

(Step S104b) The preparation processing unit 1321 of the HeNB 13-1 transmits the CA preparation notification information received from the eNB 12 to the UE 14. Thereafter, the process proceeds to step S105b.

(Step S105b) After receiving the CA preparation notification information from the eNB 12, the synchronization processing unit 1422 of the UE 14 performs a synchronization process on the CC in the band A2 with the eNB 12. After the CA request information is input from the preparation processing unit 1221, the synchronization processing unit 1222 of the eNB 12 performs synchronization processing on the CC in the band A <b> 2 with the UE 14. Thereafter, the process proceeds to step S106b.

(Step S106b) The synchronization processing unit 1422 of the UE 14 generates a synchronization processing completion signal, and outputs the generated synchronization processing completion signal to the band management unit 1423. The synchronization processing unit 1422 of the UE 14 generates CA preparation confirmation information (ACK), and transmits the generated CA preparation confirmation information to the HeNB 13-1. The preparation processing unit 1321 of the HeNB 13-1 receives CA preparation confirmation information from the UE. Thereafter, the process proceeds to step S107b.

(Step S107b) After the synchronization processing management signal is input from the synchronization processing unit 1422, the band management unit 1423 of the UE 14 generates CC information indicating the band A2 to the eNB 12, and the generated CC information is transmitted to the radio reception unit 1412 and The data is output to the wireless transmission unit 1415. The band management unit 1423 generates CA start information indicating that CA with the eNB 12 has started using the CC of the band A2, and transmits the generated CA start information to the eNB 12 using the CC of the band A2.
The band management unit 1223 of the eNB 12 generates CC information indicating the band A2 to the UE 14, and outputs the generated CC information to the radio reception unit 1212 and the radio transmission unit 1215. Thereafter, the process proceeds to step S108b.

(Step S108b) The eNB 12 and the UE 14 start communication using the CC of the band A2. That is, the UE 14 receives user data from the counterpart device as a reception signal via the eNB 12 using the CC of the band A2, and transmits user data to the counterpart device as a transmission signal. Thereafter, the process ends.

Next, the eNB search process in step S101b described above will be described.
FIG. 22 is a flowchart showing eNB search processing according to the third embodiment.

(Step S1011b) The communication measurement unit 1421 of the UE 14 measures the communication amount with the HeNB 13-1 based on the received signal input from the demodulation unit 1413. Thereafter, the process proceeds to step S1012b.

(Step S1012b) The communication measuring unit 1421 determines whether or not CA is necessary based on the measured communication volume. For example, when the measured communication volume is larger than the predetermined communication volume, the communication measurement unit 1421 determines that CA is required. The communication measuring unit 1421 determines that the CA is unnecessary when the measured communication volume is equal to or smaller than the predetermined communication volume. When it is determined that CA is required (step S1012b Y), the process proceeds to step S1013b. If it is determined that the CA is not necessary (step S1012b N), the process is terminated.

(Step S1013b) The synchronization processing unit 1422 extracts a synchronization signal from the received signal received from the eNB 12. Based on the extracted synchronization signal, the synchronization processing unit 1422 searches for an eNB 12 that has a cell where the UE 14 is located and can use a new CC. When the eNB 12 that can use the new CC has been detected (step S1013b Y), the process proceeds to step S102b (see FIG. 21). When the eNB 12 that can use the new CC cannot be detected (step S1013b, N), the process ends.

Note that the number of times that the synchronization processing unit 1422 performs the process (eNB search) for detecting the eNB 12 that can use the new CC is not limited to one. The synchronization processing unit 1422 may repeat the eNB search until the eNB 12 is found. However, if the eNB is not found even after repeating the eNB search for a predetermined number of times (for example, three times) or for a predetermined time (for example, 30 seconds), the synchronization processing unit 1422 realizes the CA. Judge that it is not possible. When it is determined that CA cannot be realized, the synchronization processing unit 1422 may repeat the eNB search after a predetermined time (for example, 180 seconds) has elapsed. Further, the synchronization processing unit 1422 may repeat the eNB search at a predetermined time interval (for example, 180 seconds). Further, the synchronization processing unit 1422 may stop the eNB search and output CA impossible information (NACK) to the modulation unit 1414 as a transmission signal to the HeNB 13-1. Note that the synchronization processing unit 1422 may stop the eNB search when the communication amount measured by the communication measurement unit 1421 does not exceed a predetermined communication amount. In that case, the synchronization processing unit 1422 may not output the CA impossibility information.

(Modification 3-1)
Next, a modification of the third embodiment will be described.
In the modified example 3-1, the synchronization processing unit 1422 of the UE 14 represents requesting CA with the eNB 12, and generates CA request information (CA request command) represented by a command in a specific format.

FIG. 23 is a sequence diagram illustrating a modification of the communication process according to the third embodiment.
The communication process shown in FIG. 23 is common to the communication process shown in FIG. 21 in that it includes steps S101b and S103b-S108b. However, the communication process illustrated in FIG. 23 includes step S202b instead of step S102b included in the communication process illustrated in FIG. In the communication process shown in FIG. 23, step S202b is executed after step S101b.

(Step S202b) The synchronization processing unit 1422 of the UE 14 generates CA request information that is CA request information for the eNB 12 discovered in Step S101b and represented by a command in a specific format. The synchronization processing unit 1422 transmits the generated CA request information to the HeNB 13-1 using the CC of the band B2. Thereafter, the process proceeds to step S103b.

(Modification 3-2)
Next, another modified example according to the third embodiment will be described.
In Modification 3-2, the CA request information generated by the synchronization processing unit 1422 of the UE 14 is added to other command information and transmitted to the HeNB 13-1. The other command information is, for example, quality information generated by the communication measuring unit 1421. The communication measuring unit 1421 may include communication amount information representing the calculated communication amount in the generated quality information. When the CA request signal is input from the synchronization processing unit 1422, the communication measurement unit 1421 adds the CA request signal to the quality information and outputs it to the modulation unit 1414 as an output signal to the HeNB 13-1.

FIG. 24 is a sequence diagram illustrating another modification of the communication process according to the third embodiment.
The communication process shown in FIG. 24 is common to the communication process shown in FIG. 21 in that it includes steps S101b and S103b-S108b. However, the communication process illustrated in FIG. 24 includes step S302b instead of step S102b included in the communication process illustrated in FIG. Here, step S302b is executed after step S101b.

(Step S302b) The synchronization processing unit 1422 of the UE 14 generates CA request information indicating that a CA is requested with the eNB 12 detected in Step S101b, and outputs the generated CA request information to the communication measurement unit 1421. The communication measurement unit 1421 adds the CA request information input from the synchronization processing unit 1422 as a part of the quality information (another command). The communication measurement unit 1421 transmits the CA request information added as part of the quality information to the HeNB 13-1. Thereafter, the process proceeds to step S103b.
In step S103b, the preparation processing unit 1321 of the HeNB 13-1 extracts CA request information from the quality information received from the UE 14.

(Modification 3-3)
Next, another modified example according to the third embodiment will be described.
In Modification 3-3, when the synchronization processing unit 1422 of the UE 14 detects a plurality of eNBs 12 that can use a new CC, the synchronization processing unit 1422 selects one of the detected plurality of eNBs 12 (for example, the band A2 and the eNB 12). For example, the quality information received from each eNB from the communication measurement unit 1421 is input to the synchronization processing unit 1422, and the eNB 12 (best cell) of the CC having the highest communication quality represented by the input quality information is selected. The synchronization processing unit 1422 generates CA request information for the eNB 12 of the selected CC, and outputs the generated CA request information to the modulation unit 1414 as a transmission signal to the eNB 12.

FIG. 25 is a sequence diagram illustrating another modification of the communication process according to the third embodiment.
The communication process shown in FIG. 25 includes steps S101b, S401b, and S102b-S108b. The communication process of FIG. 25 is common to the communication process shown in FIG. 21 in that it includes steps S101b to S108b. However, step S401b is executed after step S101b.

(Step S401b) When a plurality of eNBs that can use a new CC are detected, the synchronization processing unit 1422 selects one eNB 12 (band A2 in the example of FIG. 25) having the highest communication quality. For example, the quality information received from each eNB from the communication measurement unit 1421 is input to the synchronization processing unit 1422, and the eNB 12 of the CC having the highest communication quality represented by the input quality information is selected as the best cell. Thereafter, the process proceeds to step S102b.
In step S102b, the synchronization processing unit 1422 generates the PI of the best cell as CA request information, and transmits the generated PI to the HeNB 13-1.

In the third embodiment, the case has been described as an example where the UE 14 determines whether or not the CA is necessary based on the information amount of the downlink received signal, and performs CA for both the downlink and the uplink. In 3rd Embodiment, it is not restricted to this, You may perform CA only for a downlink.
In the third embodiment, the UE 14 may determine whether or not CA is necessary based on the uplink traffic. Here, the communication measurement unit 1421 communicates with the connection destination base station apparatus (for example, the HeNB 13-1) based on the transmission signal input from the data processing unit 143 instead of the reception signal input from the demodulation unit 1413. The amount of uplink communication related to communication is calculated.
In this case, CA may be performed only for the uplink.
Note that the UE 14 may determine whether or not the CA is necessary based on the total communication amount of the uplink communication amount and the downlink communication amount. Here, the communication measurement unit 1421 calculates the total communication amount by adding the downlink communication amount and the uplink communication amount calculated by performing the above-described processing. The communication measuring unit 1421 determines whether or not the CA is necessary based on the calculated total communication amount.

As described above, the third embodiment relates to a communication system 1b including the eNB 12, the HeNB 13 whose partial area of the cell 32 is the cell 33, and the UE. In the third embodiment, the UE 14 communicates with the HeNB 12 using the frequency band B2, and the UE 14 transmits CA request information indicating that communication with the eNB 12 is requested using the frequency band A2 different from the frequency band B2. Generate. UE14 transmits the produced | generated request information to HeNB13. Therefore, in the third embodiment, the UE 14 requests communication between the UE 14 and the eNB 12 that can communicate in the frequency band A2 in accordance with the communication status with the HeNB 13 in the frequency band B2, so that the use efficiency of the frequency resource does not decrease. .

(Fourth embodiment)
Next, a fourth embodiment according to the present invention will be described. Portions having the same configuration and processing as those of the third embodiment are denoted by the same reference numerals.
The communication system 2b according to the fourth embodiment relates to a communication system including the eNB 12, the HeNBs 23-1 to 23-3 having the partial region of the cell 32 as the cell 33, and the UE. Hereinafter, the HeNBs 23-1 to 23-3 may be collectively referred to as the HeNB 23. The HeNB 23 communicates with the UE 14 using the band B2, generates CA request information indicating that communication between the eNB 12 and the UE 14 is requested using the band A2 different from the band B2, and transmits the CA request information to the UE 14. .

In 4th Embodiment, the structure which judges necessity of CA in HeNB is provided.
FIG. 26 is a schematic diagram illustrating a communication system 2b according to the fourth embodiment.
A communication system 2b according to the fourth embodiment includes a RAN 11, an eNB 12, HeNBs 23-1 to 23-3, a UE 14, and an MME 15. That is, the communication system 2b is common to the communication system 1a (see FIG. 4) in that it includes the RAN 11, the eNB 12, the UE 14, and the MME 15. The communication system 2b is different from the communication system 1a in that HeNBs 23-1 to 23-3 are provided instead of the HeNBs 13-1 to 13-3.

FIG. 27 is a schematic diagram illustrating the configuration of the HeNB 23 according to the fourth embodiment. The HeNB 23 illustrated in FIG. 27 corresponds to the HeNBs 13-1, 13-2, and 13-3 illustrated in FIG.
The HeNB 23 includes a transmission / reception unit 131, a communication control unit 232, and a data processing unit 133. The communication control unit 232 further includes a communication measurement unit 2323 in addition to the preparation processing unit 1321 and the bandwidth management unit 1322.
The communication measurement unit 2323 determines whether or not CA is necessary based on the communication amount of the received signal received from the UE 14. The communication measurement unit 2323 measures a communication amount related to communication with the connection destination UE 14 based on the reception signal input from the demodulation unit 1213. The communication measuring unit 2323 determines whether the calculated communication amount is larger than a predetermined communication amount. When it is determined that the communication amount is larger than the predetermined communication amount, the communication measurement unit 2323 generates CA request information. The generated CA request information indicates that the HeNB 23 requests communication between the eNB 12 and the UE 14 using a CC of a new band A2 different from the CC band B2 used for communication with the UE 14. Such communication is related to transmission / reception of user data between the UE 14 and the counterpart device.
The communication measurement unit 2323 outputs the generated CA request information to the modulation unit 1314 as a transmission signal to the UE 14.

CA request information is input from the demodulator 1413 to the synchronization processor 1422 of the UE 14 as a received signal from the HeNB 23. The synchronization processing unit 1422 performs the above-described eNB search after the CA request information is input. After the eNB search is completed, the synchronization processing unit 1422 generates CA request confirmation information (ACK) indicating that the CA request information has been received, and the generated CA request confirmation information is transmitted to the modulation unit 1414 as a transmission signal to the HeNB 23. Output.
Thereafter, CA request confirmation information is input from the demodulation unit 1313 to the preparation processing unit 1321 of the HeNB 23 as a reception signal from the UE 14. Thereafter, the preparation processing unit 1321 performs the CA preparation processing described above.

Next, communication processing according to the fourth embodiment will be described.
FIG. 28 is a sequence diagram illustrating communication processing according to the fourth embodiment.
The communication process shown in FIG. 28 includes steps S501b, S101b, S502b, and S103b-S108b. The communication process of FIG. 28 is common to the communication process shown in FIG. 21 in that steps S101b and S103b-S108b are included. However, in the communication process of FIG. 28, step S101b is executed after step S501b, and step S502b is executed after step S101b.

(Step S501b) The communication measuring unit 2323 determines whether or not CA is necessary based on the communication amount of the received signal received from the UE 14. When it is determined that the communication amount is larger than the predetermined communication amount, the communication measurement unit 2323 generates CA request information and transmits the generated CA request information to the UE 14. Thereafter, the process proceeds to step S101b. In step S101b, the communication measurement unit 1421 of the UE 14 omits the measurement of the traffic volume, and the communication measurement unit 1421 of the UE 14 omits the process related to the traffic volume measurement and the CA necessity determination (see FIG. 22, steps S1011b and S1012b). Also good.

(Step S502b) After completing the eNB search (see FIG. 22, step S1013b), the synchronization processing unit 1422 of the UE 14 generates CA request confirmation information, and transmits the generated CA request confirmation information to the HeNB 23-1. The preparation processing unit 1321 of the HeNB 23-1 receives CA request confirmation information from the UE 14. Thereafter, the process proceeds to step S103b.

Note that, in the fourth embodiment, as in Modification 3-3 of the third embodiment described above, in step S101b, the synchronization processing unit 1422 detects that a plurality of eNBs 12 that can use a new CC are detected. May select one eNB 12 of the CC with the highest communication quality.

In the fourth embodiment, an example has been described in which the HeNB 23 determines whether the CA is necessary based on the information amount of the uplink received signal and performs CA for both the uplink and the downlink. In 4th Embodiment, it is not restricted to this, You may perform CA only for an uplink.
In the fourth embodiment, the HeNB 23 may determine whether or not the CA is necessary based on the downlink traffic. Here, the communication measurement unit 2323 determines the downlink communication amount related to the communication with the UE 14 as the connection destination based on the reception signal input from the data processing unit 133 instead of the reception signal input from the demodulation unit 1313. calculate. In this case, CA may be performed only for the downlink.
Note that the HeNB 23 may determine whether or not the CA is necessary based on the total communication amount of the uplink communication amount and the downlink communication amount. Here, the communication measurement unit 2323 calculates the total communication amount by adding the downlink communication amount and the uplink communication amount calculated by performing the above-described processing. The communication measurement unit 2323 determines whether or not the CA is necessary based on the calculated total communication amount.

As described above, the fourth embodiment relates to a communication system 2b including the eNB 12, the HeNB 23 whose cell 33 is a partial region of the cell 32, and the UE 14. In the fourth embodiment, the HeNB 23 communicates with the UE 14 using the frequency band B2, and the HeNB 23 requests a communication between the HeNB 23 and the UE 14 using the frequency band A2 different from the frequency band B2. Generate information. The HeNB 23 transmits the generated CA request information to the UE 14. Therefore, in the fourth embodiment, the HeNB 23 requests communication using the UE 14 and the frequency band A2 according to the communication status with the UE 14 in the frequency band B2, so that the use efficiency of the frequency resource does not decrease.

Note that the eNBs 12, 12a, 22, HeNBs 13-1, 13-2, 13-3, 13a, or part of the UE 14 in the first to fourth embodiments described above, for example, the preparation processing unit 1221 and the bandwidth management unit 1222 The communication measurement unit 2223, the preparation processing unit 1321, the synchronization processing unit 1322, the bandwidth management unit 1323, the communication measurement unit 1421, the synchronization processing unit 1422, and the bandwidth management unit 1423 may be realized by a computer. In that case, the program for realizing the control function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read by a computer system and executed.

The “computer system” here is a computer system built in the eNB 12, 12a, 22, HeNB 13-1, 13-2, 13-3, 13a, 23, or the UE 14, and includes an OS and peripheral devices. Including hardware. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM or a CD-ROM, and a hard disk incorporated in a computer system.

Furthermore, the “computer-readable recording medium” is a medium that dynamically holds a program for a short time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, In such a case, a volatile memory inside a computer system serving as a server or a client may be included and a program that holds a program for a certain time. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

Further, a part or all of the eNBs 12, 12a, 22, HeNBs 13-1, 13-2, 13-3, 13a, or the UE 14 in the first to fourth embodiments described above are integrated into LSI (Large Scale Integration) or the like. It may be realized as an integrated circuit. Each functional block of the eNBs 12, 12a, 22, HeNBs 13-1, 13-2, 13-3, 13a, and the UE 14 may be individually made into a processor, or a part or all of them may be integrated into a processor. . Further, the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. Further, in the case where an integrated circuit technology that replaces LSI appears due to progress in semiconductor technology, an integrated circuit based on the technology may be used.

As described above, the first to fourth embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to the above-described one, and the scope of the present invention is not deviated. Various design changes can be made.

The present invention can be applied to a communication system, a mobile station apparatus, a base station apparatus, a communication method, and the like that do not reduce the use efficiency of frequency resources.

1a, 1a, 2a, 2b ... communication system,
11 ... RAN,
12, 12a, 12b, 22 ... eNB,
121... Transceiver unit,
1211 ... Antenna part,
1212 ... Wireless receiver,
1213 ... demodulator,
1214: Modulation unit,
1215: Wireless transmission unit,
122, 222... Communication control unit,
1221 ... Preparation processing unit,
1222 ... Band management unit,
2223: Communication measuring unit,
123 ... data processing unit,
13 (13-1 to 13-3), 13a, 13b... HeNB,
23 (23-1 to 23-3) ... HeNB,
131... Transceiver unit,
1311 ... Antenna portion,
1312 ... Wireless receiver,
1313: Demodulator,
1314... Modulation unit,
1315 ... Wireless transmission unit,
132: Communication control unit,
1321 ... Preparation processing unit,
1322 ... synchronization processing unit,
1323 Bandwidth management unit,
2323: Communication measuring unit,
133: Data processing unit,
14 ... UE,
141... Transceiver unit,
1411 ... Antenna portion,
1412 ... Wireless receiver,
1413 ... demodulator,
1414: modulation unit;
1415 ... wireless transmission unit,
142 ... communication control unit,
1421 ... Communication measuring unit,
1422 ... synchronization processing unit,
1423 ... Bandwidth management unit,
143 Data processing unit,
15 ... MME

Claims (11)

1. A communication system comprising a macro cell base station device, a small base station device having a partial cell area of the macro cell base station device as a cell, and a mobile station device,
   The mobile station device
   A transceiver that communicates with the macrocell base station apparatus or the small base station apparatus using a first frequency band;
   Generating request information indicating requesting communication with a small base station apparatus or a macrocell base station apparatus that is not communicating with the transceiver using a second frequency band different from the first frequency band, and A communication control unit for transmitting request information to the macro cell base station device or the small base station device communicating with the transceiver unit;
   A communication system comprising:
2. The mobile station device
   A communication measuring unit that measures the communication amount with the macro cell base station device or the small base station device,
   The communication system according to claim 1, wherein the communication control unit determines whether to perform communication using the second frequency band based on a communication amount measured by the communication measurement unit.
3. The communication control unit
   The communication system according to claim 1, wherein a small base station device or a macro cell base station device capable of communicating using the second frequency band is searched.
4. The communication system according to claim 3, wherein the communication control unit transmits, as the request information, location information indicating presence in a cell of the searched small base station device or macro cell base station device.
5. The communication control unit adds the request information to measurement information related to communication with the macro cell base station apparatus or the small base station apparatus, and transmits the measurement information to the macro cell base station apparatus or the small base station apparatus. The communication system described.
6. The communication system according to claim 3, wherein the communication control unit selects a small base station device or a macro cell base station device having the highest communication quality when a plurality of small base station devices or macro cell base station devices capable of communication are detected. .
7. A communication system comprising a macro cell base station device, a small base station device having a partial cell area of the macro cell base station device as a cell, and a mobile station device,
   The macro cell base station device or the small base station device is
   A transmission / reception unit that communicates with the mobile station apparatus using a first frequency band;
   Request information representing a request for communication between the mobile station apparatus and a small base station apparatus or macrocell base station apparatus that is not communicating with the transceiver using a second frequency band different from the first frequency band And a communication control unit for transmitting the request information to the mobile station apparatus communicating with the transmission / reception unit,
   A communication system comprising:
8. A transceiver unit for communicating with a macro cell base station device or a small base station device having a cell in a region of a part of a cell of the macro cell base station device using a first frequency band;
   Using a second frequency band different from the first frequency band, generating request information indicating requesting communication with a small base station device or a macro cell base station device that is not communicating with the transceiver unit, A communication control unit that transmits the request information to the macro cell base station device or the small base station device that is communicating with the transmission / reception unit;
   A mobile station apparatus comprising:
9. A transceiver that communicates with the mobile station device using the first frequency band;
   A small-sized base station apparatus that uses a second frequency band different from the first frequency band as a cell, or a macro cell base station apparatus that does not communicate with the transmission / reception unit, or a partial area of a cell of the macro cell base station apparatus as a cell Or, a communication control unit that generates request information representing a request for communication between a macro cell base station device and the mobile station device, and transmits the request information to the mobile station device that is communicating with the transmission / reception unit;
   A base station apparatus comprising:
10. A communication method in a mobile station device,
    The mobile station device communicates with a macro cell base station device or a small base station device having a part of a cell of the macro cell base station device as a cell using a first frequency band,
    The mobile station apparatus generates request information representing a request for communication with a small base station apparatus or macrocell base station apparatus that is not communicating, using a second frequency band different from the first frequency band. And transmitting the request information to the communicating macro cell base station apparatus or the small base station apparatus.
11. A macro cell base station apparatus or a communication method in a small base station apparatus having a cell as a partial area of a cell of the macro cell base station apparatus,
    The macro cell base station device or the small base station device communicates with the mobile station device using a first frequency band,
    The macro cell base station apparatus or the small base station apparatus uses a second frequency band different from the first frequency band, and is not communicating with the small base station apparatus or macro cell base station apparatus and the mobile station apparatus. The communication method which produces | generates the request information showing requesting communication of this, and transmits the said request information to the said mobile station apparatus which is communicating.

Images