Technical field
[0001]
　The present disclosure relates to devices and methods.
Background technique
[0002]
　Recent wireless communication environment are faced with the problem of the rapid increase in data traffic. Therefore, In 3GPP, by increasing the network density by installing a large number of small cells within a macrocell, it is considering to distribute traffic. In this way the technology to take advantage of the small cell, that small cell enhancement. Incidentally, the small cells are arranged overlapping with the macrocell, small various types of cells than macrocells (e.g., femtocell, nanocells, picocells and a micro cell) is a concept that may include. However, with the increase of small cells, because the power consumption of the entire network with the inter-cell interference increases can become enormous, in Patent Document 1, a technique for the adaptive sleep Small cell has been developed .
[0003]
　Further, as one of the expansion plan of radio resources utilization of 6GHz or more frequency bands called millimeter wave band it has been studied. However, the millimeter-wave band, linearity is strong, since the radio wave propagation attenuation is large, take advantage of in the small cell is expected smaller than macrocells. Under all it is not used situations where the vast frequency band of the millimeter wave band, can be in small cells, to turn on / off a portion of the frequency band. Then, with respect to the frequency band of the OFF state, the signal for measurement to allow measuring the quality on the terminal device side it is transmitted from the base station.
CITATION
Patent Literature
[0004]
Patent Document 1: JP 2015-61262 JP
Summary of the Invention
Problems that the Invention is to Solve
[0005]
　However, it has a large power burden for the base station that transmits a signal for measurement by using all the vast frequency band of the millimeter wave band. It is, it is larger power burden for the terminal apparatus to measure the signal for measurement at all vast frequency bands. Therefore, the transmitted signal for measurement in some frequency bands, it is desirable that provides a mechanism becomes possible to measure the terminal device side.
Means for Solving the Problems
[0006]
　According to the present disclosure, an apparatus for operating a small cell, the unit frequency of one or more off-state in the plurality of unit frequency bands may be in the on state for uplink communications or downlink communications in the small cell of band processing unit for selecting the unit frequency band of the off-state to be used for transmission of the discovery signal for enabling measurement in the unit frequency band in the oFF state, apparatus comprising a are provided.
[0007]
　Further, according to the present disclosure, a device for connecting the small cell, the one or more off-state in the plurality of unit frequency bands may be in the on state for uplink communications or downlink communications in the small cell processing unit that performs measurement for a discovery signal transmitted using the unit frequency band selected from the unit frequency band, device comprising a are provided.
[0008]
　Further, according to the present disclosure, of the unit frequency band of one or more off-state in the plurality of unit frequency bands may be in the on state for uplink communication or downlink communication in small cell, the unit of the off-state selecting by the processor the unit frequency band of the off-state to be used for transmission of the discovery signal to allow measurement in the frequency band, the method comprising is provided.
[0009]
　Further, according to the present disclosure, the unit frequency band selected from the unit frequency band of one or more off-state in the plurality of unit frequency bands may be in the on state for uplink communication or downlink communication in a small cell It is performed by processor measurement for discovery signals transmitted by using the method comprising is provided.
Effect of the invention
[0010]
　According to the present disclosure described above, the transmitted signal for measurement in some frequency bands, a mechanism that makes it possible to measure the terminal device side is provided. Incidentally, the above effect is not necessarily restrictive, with the above effects, or instead of the above effects, any effects shown herein, or other effects that may be grasped from the description, it may be achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011]
FIG. 1 is an explanatory diagram for explaining an overview of a system according to an embodiment of the present disclosure.
[2] is an explanatory diagram for describing the component carrier.
3 is an explanatory diagram for describing the component carrier on / off.
FIG. 4 is an explanatory diagram for describing DRS.
5 is a sequence diagram showing an example of a flow of processing related to the measurement of the DRS.
6 is a block diagram showing an example of the configuration of the small cell base station according to the embodiment.
7 is a block diagram showing an example of a configuration of a terminal device according to the embodiment.
8 is an explanatory diagram for explaining the technical features according to the first embodiment.
9 is an explanatory diagram for explaining the technical features according to the embodiment.
FIG. 10 is an explanatory diagram for explaining the technical features according to the embodiment.
11 is a sequence diagram illustrating an example of a process flow of the DRS request procedure performed in the system according to the embodiment.
FIG. 12 is an explanatory diagram for explaining the technical features according to the second embodiment.
13 is a sequence diagram illustrating an example of a process flow of the CC state change request procedure performed system 1 Oite according to the embodiment.
It is a block diagram showing a first exemplary configuration of FIG. 14] eNB.
It is a block diagram showing a second exemplary configuration of FIG. 15] eNB.
Is a block diagram illustrating an example of FIG. 16 schematic configuration of a smart phone.
17 is a block diagram showing an example of a schematic configuration of a car navigation system.
DESCRIPTION OF THE INVENTION
[0012]
　Reference will now be described in detail preferred embodiments of the present disclosure. In the specification and the drawings, components having substantially the same function and structure are a repeated explanation thereof by referring to the figures.
[0013]
　The description will be made in the following order.
　　1. Introduction
　　　1.1. Small cell
　　　1.2. Carrier aggregation
　　　1.3. Of the component carrier on / off
　　2. Configuration example
　　　2.1. Configuration example of the small cell base station
　　　2.2. Configuration of the terminal device
　　3. The first embodiment
　　　3.1. Technical problems
　　　3.2. Technical features
　　　3.3. Processing of flow
　　4. Second Embodiment
　　　4.1. Technical problems
　　　4.2. Technical features
　　　4.3. The flow of processing
　　5. Application Example
　　6. Summary
[0014]
　<< 1. Introduction
　　>> <1.1. Small Cell>
　FIG. 1 is an explanatory diagram for explaining an overview of a system 1 according to an embodiment of the present disclosure. As shown in FIG. 1, the system 1 includes a wireless communication device 10, the terminal device 20 and the communication control device 30.
[0015]
　In the example of FIG. 1, the communication control device 30 is a macrocell base station. Macrocell base station 30 provides wireless communication service to one or more terminal devices 20 located inside the macro cell 31. Macrocell base station 30 is connected to a core network 15. The core network 15 is connected to a packet data network (PDN) 16 via a gateway device (not shown). Macrocell 31 can, for example, LTE (Long Term Evolution), LTE-A (LTE-Advanced), GSM (registered trademark), UMTS, W-CDMA, CDMA200, WiMAX, any wireless communication system such as WiMAX2 or IEEE802.16 it may be operated in accordance with. Incidentally, not limited to the example of FIG. 1, even if the control node of the core network 15 or the PDN16 (upper node of the macrocell base station), have a function of cooperatively controlling wireless communication in the macro cell and small cell good. Note that the macro cell base station may also be referred to as Macro eNodeB.
[0016]
　The wireless communication device 10 is a small-cell base station to operate the small cell 11. Small cell base station 10 typically has the authority to allocate the radio resources to the terminal device 20 connected to the own device. However, allocation of radio resources for coordinated control may be delegated to at least partially the communication control device 30. Wireless communication device 20 may be a small-cell base station which is fixedly installed as shown in FIG. 1, it may be a dynamic AP (access point) to operate dynamically Small cell 11 . Incidentally, the small cell base station may also be referred to as pico eNB or Femto eNB.
[0017]
　The terminal device 20 connected to the macrocell base station 30 or the small cell base station 10, enjoy wireless communication services. For example, the terminal device 20 connected to the small cell base station 10 receives a control signal from the macrocell base station 30 receives data signals from the small cell base station 10. The terminal device 20 is also referred to as a user. The user, user equipment (User Equipment: UE) and may also be referred to. Here the UE can be a UE that is defined in the LTE or LTE-A, it may mean more generally communication equipment.
[0018]
　　<1.2. Carrier aggregation>
　The following describes technology relating to carrier aggregation defined in LTE Release 10.
[0019]
　　(1) component carriers
　and carrier aggregation, the communication channel between the base station and the terminal device, for example, the unit frequency bands supported is formed by a plurality of integrated in LTE, is a technique for improving the communication throughput . Individual unit frequency band included in one communication channel formed by the carrier aggregation, component carrier (CC: Component Carrier) called. Here CC on may be a CC which is defined in LTE or LTE-A, may mean more generally unit frequency band.
[0020]
　In LTE release 10, it is possible to integrate up to five CC. Further, one CC is 20MHz wide. Incidentally, CC of each to be integrated, may be arranged in series along the frequency axis, or may be spaced apart. Further, whether used to integrate any CC, it can be set for each terminal device.
[0021]
　A plurality of CC to be integrated, and one PCC (Primary Component Carrier), are classified into the other SCC and (Secondary Component Carrier). For each terminal device, PCC is different. PCC are the most important CC, CC communication quality is most stable is it is desirable that selected.
[0022]
　Figure 2 is an explanatory diagram for describing the component carrier. In the example shown in FIG. 2, a portion of the five CC, 2 one UE indicates a state of using integrated. For more information, UE1 is used to integrate CC1, CC2 and CC3, UE2 is using to integrate CC2 and CC4. In addition, UE1 of the PCC is a CC2. UE2 of the PCC is a CC4.
[0023]
　Here, the selection of the PCC is implementation-dependent. Change of SCC is carried out by adding another SCC and SCC deleted. In other words, it is difficult to make the change of SCC directly.
[0024]
　　(2) PCC formation and change
　terminal apparatus, when the transition from the RRC Idle state to the RRC Connected state, CC for establishing a first connection is PCC. Change of PCC is carried out by the same procedure and the handover.
[0025]
　The formation of the PCC is carried out by a procedure called Connection establishment. This procedure is a procedure that is initiated as a trigger a request from the terminal device side.
[0026]
　Change of PCC is carried out by a procedure called Connection Reconfiguration. This procedure involves sending and receiving messages of the handover. This procedure is a procedure that is initiated from the base station side.
[0027]
　　(3) Addition of SCC
　additional SCC is carried out by a procedure called Connection Reconfiguration. This procedure is a procedure that is initiated from the base station side. SCC is added to the PCC, so that the subordinate to PCC. Adding the SCC is also referred to activate the SCC.
[0028]
　　(4) Remove SCC
　deletion of the SCC is carried out by a procedure called Connection Reconfiguration. This procedure is a procedure that is initiated from the base station side. In this procedure, the particular SCC that was specified in the message is deleted. It should be noted that the deletion of the SCC, is also performed by the procedure, called the Connection Re-establishment. This procedure is a procedure to be initiated from the terminal device side. According to this procedure, all of the SCC is deleted. That you want to delete the SCC is also referred to de-activate the SCC.
[0029]
　　(5) special role of the PCC
　PCC has a special role that is different from the SCC. For example, transmission and reception of NAS signaling in Connection establishment is performed only by the PCC. The transmission of the PUCCH (Physical Uplink Control Channel) is carried out only in the PCC. Note that the control signal of the uplink, for example, there is ACK or NACK, and scheduling request, etc. indicates the reception success or failure for the transmitted data in downlink. In addition, the procedure of the Connection Re-establishment from the detection of Radio Link Failure is also performed only in the PCC.
[0030]
　　<1.3. The component carrier on / off>
　The following describes techniques defined in LTE Release 12 with respect to carrier aggregation.
[0031]
　In LTE release 12, in a macro cell base station and the small cell base station is shown a scenario using a different frequency. For example, the macrocell base station is assigned a frequency of about 2 GHz, the small cell base station may be assigned a high frequency of 5GHz and the like.
[0032]
　Also, in the LTE release 12, base station intermittently turned on / off to be at least part of the frequency band (i.e., be to / OFF state to the ON state) is specified. This is primarily in order to reduce power consumption by a large number small cell base station. Further, the second, by turning off the unnecessary frequency band used, in order to reduce interference.
[0033]
　Figure 3 is an explanatory diagram for describing on / off component carrier. Figure 3 shows an example of a CC provided by a certain base station, a CC1 and CC2 is ON, CC3 is off. Terminal, by activating the CC in the ON state, it is possible to perform uplink communication or downlink communication using the CC with the base station. That, CC in the ON state, is a candidate for activation possible CC. The base station, with respect to CC3 in the off state, transmits a signal for measurement to allow measuring the quality at the terminal device side. Signal for this measurement may also be referred to as a DRS (Discovery Reference signal). DRS here may be a DRS defined in LTE or LTE-A, more commonly signal measurement (e.g., discovery signals) may be means. Terminal device, DRS by measuring the quality of the downlink channel CC3 in the off state, reports the measurement result to the cell base station. The base station, based on the measurement result, determines whether to turn on CC3 off.
[0034]
　Figure 4 is an explanatory diagram for describing DRS. Figure 4 shows the transmission timing of the DRS schematically. As shown in FIG. 4, DRS is intermittently, may be transmitted and periodically. Period may be, for example, 50 ms (milliseconds). Furthermore, this period is variable, setting information of the period is notified from the base station to the terminal. In contrast, CRS is a reference signal (Cell Specific Reference Signal) is inserted into all subframes, the cycle was 1ms, for example.
[0035]
　Figure 5 is a sequence diagram showing an example of the flow of processing related to the measurement of the DRS. As shown in FIG. 5, first, the base station transmits a DRS (step S12). At that time, the base station in the CC in the OFF state, shall be pre-transmitted periodically DRS in the transmission cycle and CC were set commonly with the terminal device. Terminal in accordance with pre-set was measured in DRS (step S14), and transmits the measurement result to the base station (step S16). In the present specification, the measurement of the DRS, also referred to as measurement, referred to the measurement results with the measurement report. It should be noted that the measurement report is transmitted using the uplink of the on-state CC. The base station, based on the measurement report, to determine the on-off of the CC (step S18). For example, the base station turns on the CC in the off state it is determined to be turned on, off CC on-state it is determined to be off.
[0036]
　In a typical implementation, macro cell base station does not perform the on-off of the component carrier, the small cell base station performs. Therefore, in the following description, the small cell base station that performs on-off of the component carrier as a target. Of course, this is not intended to narrow the scope of the present technology, the technology is also applicable to the macrocell base station or the like.
[0037]
　<< 2. Configuration example
　　>> <2.1. Configuration Example> small cell base station
　Subsequently, referring to FIG. 6, the configuration of the small cell base station 10 according to an embodiment of the present disclosure. Figure 6 is a block diagram showing an example of the configuration of the small cell base station 10 according to an embodiment of the present disclosure. Referring to FIG. 6, the small cell base station 10 includes an antenna unit 110, the wireless communication unit 120, a network communication unit 130, storage unit 140 and the processing unit 150.
[0038]
　(1) Antenna unit 110
　antenna unit 110 radiates into the space a signal output by the radio communication unit 120 as a radio wave. The antenna unit 110 converts the radio waves of space signal, and outputs the signal to the radio communication unit 120.
[0039]
　(2) wireless communication unit 120
　radio communication unit 120 transmits and receives signals. For example, wireless communication unit 120 transmits a downlink signal to the terminal device, it receives uplink signals from the terminal device.
[0040]
　(3) Network communication unit 130
　network communication unit 130 sends and receives information. For example, the network communication unit 130 transmits the information to other nodes, to receive information from other nodes. For example, the other nodes, including other base stations and a core network node.
[0041]
　(4) storage unit 140
　storage unit 140 temporarily or permanently storing a program and various data for the operation of the small cell base station 10.
[0042]
　(5) processing unit 150
　processing unit 150 provides various functions of the small cell base station 10. Processing unit 150 includes a transmission processing unit 151 and notification unit 153. The processing unit 150 may further include other components other than these components. That is, processor 150 may perform also the operation other than the operation of these components.
[0043]
　Operation of the transmission processing unit 151 and notification unit 153 will be described in detail later.
[0044]
　　<2.2. Configuration of Terminal Device>
　Next, with reference to FIG. 7, an example of a configuration of the terminal device 20 according to an embodiment of the present disclosure. Figure 7 is a block diagram showing an example of the configuration of the terminal device 20 according to an embodiment of the present disclosure. Referring to FIG. 7, the terminal device 20 includes an antenna unit 210, radio communication unit 220, storage unit 230 and the processing unit 240.
[0045]
　(1) Antenna unit 210
　antenna unit 210 radiates into the space a signal output by the radio communication unit 220 as a radio wave. The antenna unit 210 converts the radio waves of space signal, and outputs the signal to the wireless communication unit 220.
[0046]
　(2) wireless communication unit 220
　radio communication unit 220 transmits and receives signals. For example, wireless communication unit 220 receives the downlink signal from the base station, transmits an uplink signal to the base station.
[0047]
　(3) storage unit 230
　storage unit 230 temporarily or permanently storing a program and various data for the operation of the terminal device 20.
[0048]
　(4) processing unit 240
　processing unit 240 provides various functions of the terminal device 20. Processing unit 240 includes a measurement processing unit 241 and the request unit 243. The processing unit 240 may further include other components other than these components. That is, the processing unit 240 may perform also the operation other than the operation of these components.
[0049]
　Operation of the measurement processing section 241 and the request unit 243 will be described in detail later.
[0050]
　<< 3. The first embodiment
　　>> <3.1. Technical Issues>
　　(1) The first problem
　millimeter wave band has a large frequency band. It has a higher power burden for small cell base station 10 to transmit the DRS using all CC contained in large frequency band of the millimeter wave band. Furthermore, sending and receiving DRS using all CC contained in large frequency band of the millimeter wave band, in addition to an increase in power consumption can also cause an increase in inter-cell interference.
[0051]
　Therefore, in the present embodiment provides a mechanism capable of small-cell base station 10 transmits a DRS in some CC of CC multiple off state.
[0052]
　Here, in the millimeter wave band, the bandwidth of the CC, which has been considered 20MHz in LTE release 10, for example 40 MHZ, is assumed to be made can be changed to the wider bandwidth than said 80MHz or 160 MHz. If the expansion of such a bandwidth is made, sends a DRS in some CC, mechanisms that can be measured, it can be said to be effective for the reduction of the power burden.
[0053]
　　(2) The second problem
　is the bandwidth of the CC is that there is a plurality of types. As an example, assume CC bandwidth 20 MHz, CC bandwidth 40 MHz, the CC of bandwidth 80 MHz. Then, for each terminal device, the bandwidth of 80 MHz, or as the CC bandwidth of one 80 MHz, or as the CC bandwidth of the two 40 MHz, is used as a CC bandwidth four 20MHz or, it is assumed that can be selected. For example, there is a terminal device, when it has only the ability to handle the bandwidth of 20MHz, it is desirable that the CC of 20MHz bandwidth is turned on. Therefore, the terminal device may be performed measurement for CC bandwidth 20 MHz, for example, measurement of the CC bandwidth 80MHz is required. For each terminal apparatus, where obtaining different CC bandwidth to perform such measurement, is that the DRS is sent by CC same bandwidth common to all terminal devices for, it was inefficient .
[0054]
　Therefore, in this embodiment, the CC base station transmits a DRS, the terminal device provides a mechanism that can be requested.
[0055]
　　(3) The third problem
　it is, is larger power burden for the terminal device side not only the base station to measure the DRS in all CC contained in large frequency band. In particular, if the base station as described in the first embodiment transmits a DRS in some CC, measuring the DRS in all CC at the terminal device side waste occurs in terms of power consumption.
[0056]
　In this regard, at present, or DRS in which the period for each CC is transmitted, it has been notified to the terminal device in advance RRC signaling. However, in a situation such as whether DRS are transmitted can often be switched for each CC, it can not be said that the notification to the terminal device is sufficient.
[0057]
　Therefore, in this embodiment, it provides a mechanism that can be notified to dynamically terminal device information relating to DRS.
[0058]
　　<3.2. Technical features>
　　(1) DRS of providing
　small cell base station 10 (e.g., the transmission processing unit 151), among the plurality of CC, which may be in the on state for uplink transmission or downlink transmission in small cells, one to allow measurement of the CC of the above off-state, selects the CC in the off state to be used for transmission of the DRS. Thus, the small cell base station 10, since the selectively it is possible to transmit the DRS on some band vast millimeter wave band, the power consumption can be reduced, even between more cell interference reduction it can be. Small cell base station 10 transmits the DRS with the selected CC.
[0059]
　For example, small-cell base station 10 (e.g., the transmission processing unit 151) may be stepwise increased CC to be used for transmission of the DRS. Conversely, small cell base station 10 may be stepwise reduced the CC to be used for transmission of the DRS. Thus, for example, depending on the increase or decrease of the number of users in the cell, it is possible to provide a DRS in neither excessive nor insufficient number of CC. Additional, small cell base station 10, all capable CC to the ON state at once may be used to send DRS.
[0060]
　Here, with reference to FIG. 8 shows an example of the configuration of the CC, it will be specifically described selection of the CC to provide a DRS. CC shown in FIG. 8, with a capable to be turned on CC, and a CC that can be used to send DRS. CC1 ~ CC4 is a CC of 20MHz bandwidth. CC5 and CC6 are CC of 40MHz bandwidth. CC7 is a CC of 80MHz bandwidth. For example, if one of the CC is also in the OFF state, the small cell base station 10 provides a DRS in CC1. Then, the small cell base station 10, when turned on CC1, provides a DRS in CC2. Then, the small cell base station 10, when turned on CC2, provides a DRS in CC3. Then, the small cell base station 10, when turned on CC3, provides a DRS in CC4. Of course, small cell base station 10 may be provided DRS with CC5 ~ CC7, it may provide DRS with multiple CC. Further, the small cell base station 10, when there is a change in the CC to provide a DRS is notifies the terminal device 20. This point will be described in detail later.
[0061]
　Further, the small cell base station 10 (e.g., the transmission processing unit 151) based on the DRS of measurement results in the terminal device 20 connected to the small cell may be selected CC to be used for transmission of the DRS. Thus, the CC for example in accordance with the variation of the radio environment, it is possible to provide a DRS.
[0062]
　The terminal device 20 (e.g., measurement processing unit 241) uses the CC selected from CC of one or more off-state in the plurality of CC, which may be in the on state for uplink transmission or downlink transmission in small cell carry out the measurement of the DRS sent Te. Thus, the terminal device 20, since the measurement it is possible to perform a part of the band of the vast millimeter wave band, it is possible to reduce power consumption. The terminal device 20 notifies the measurement report to the small cell base station 10. Small cell base station 10, based on the measurement report, it is possible to select a CC in the off state to be used for transmission of the DRS.
[0063]
　Here, CC in this embodiment is assumed to be a CC of the millimeter wave band is the frequency band above 6 GHz.
[0064]
　　(2) Notification of the setting information about the DRS
　　(2.1) first setting information
　Small cell base station 10 (e.g., the notification unit 153) is information indicating a CC capable to be turned on, the small cell It notifies the terminal device 20 to be connected. Thus, the terminal device 20, at least since DRS allows Chitoku the CC that the may be sent, the first place it is possible DRS to avoid measurement in the frequency band that can not be transmitted. Information indicating capable CC to the ON state, the following also referred to as CC configuration information.
[0065]
　CC capable to be turned on may be associated with the CC that is used to send the DRS. For example, the association has a CC to be used for transmission of the DRS, it may be a combination of a CC to be in the ON state based on the DRS of the measurement report provided by the CC. The present correspondence may be bidirectional relationship. For example, if it contains information that indicates the CC1 ~ CC7 shown in FIG. 8 the CC configuration information, CC2 is may be set to the ON state based on CC1 of measurement report, CC1 is turned on based on CC2 of measurement report it may be in the state. Of course, based on CC1 of measurement report it may be at least one on-state of the CC2 ~ CC7. As described later, the terminal device 20 may request the CC to begin providing DRS. If the CC configuration information including the correspondence has been notified from the small cell base station 10, the terminal device 20, from the CC depending on the contents of the measurement report may be the ON state, to provide a DRS in the desired CC it is possible to request to start.
[0066]
　The CC that can be turned on, and CC are used for the transmission of associated DRS, may include bandwidth different. That is, the CC to be measurement, the CC is turned on, may not necessarily coincide. For example, in the example shown in FIG. 8, based on CC1 of measurement results, it may be the CC6 is turned on.
[0067]
　Notification of the CC configuration information, for example, SI (System Information), means may be used, such as RRC signaling or PDCCH (Physical Downlink Control Channel). The notification of the CC configuration information may be periodically performed or may be performed at any timing such as each time a change is present. Incidentally, CC configuration information may be static or quasi-static information.
[0068]
　　(2.2) second setting information
　Small cell base station 10 (e.g., the notification unit 153), the information relating to the arrangement of the DRS in each CC, and notifies the terminal unit 20 connected to the small cell. Here, the arrangement of the DRS, refers to the frequency or the like in the transmission cycle, and each of the CC. By this information is reported, the terminal device 20, it is possible to suitably perform measurement. This information, the following also referred to as DRS arrangement information.
[0069]
　Notification of DRS arrangement information, for example SI, means may be used, such as RRC signaling or PDCCH. The notification of the DRS arrangement information may be performed periodically or may be performed at any timing such as each time a change is present. Incidentally, DRS arrangement information may be static or quasi-static information.
[0070]
　　(2.3) Third setting information
　Small cell base station 10 (e.g., the notification unit 153) the information indicating the CC to be used for transmission of the DRS, and notifies the terminal unit 20 connected to the small cell. By this information is reported, the terminal device 20, among the CC contained in large frequency band, targeting the CC that is actually used in the transmission of the DRS, it is possible to perform measurement. This information, the following also referred to as DRS state information.
[0071]
　Here, in FIGS. 9 and 10, an example of a DRS status information. In Figure 9, the value of the bit position corresponding to each of CC1 ~ CC7 shown in FIG. 8, each CC is shown or used to send DRS is. 1 bit corresponds to CC1, 2 bit corresponds to CC2, 3 bit corresponds to CC3, 4 bit corresponds to CC4, the fifth bit corresponds to CC5, the sixth bit CC6 corresponds to, seventh bit corresponds to CC7. If the bit value is 0 indicates that it is not used for the transmission of DRS, it indicates that the bit value is used for the transmission of DRS if 1. In Figure 10, the value of the bit position corresponding to each of CC1 ~ CC4 shown in FIG. 8, each CC is shown or used to send DRS is. Information representation in such a format is effective when sending DRS by CC 20MHz wide. In this case, the DRS for 80 MHz, by four bundled with DRS of 20 MHz, can be substituted.
[0072]
　Further, the small cell base station 10, information indicating the CC to start or stop the use in the transmission of DRS, may notify the terminal device 20 connected to the small cell. That is, the small cell base station 10, when there is a change in the CC to be used for transmission of the DRS, may notify the information indicating the difference.
[0073]
　Further, the small cell base station 10, when there is a change in the CC to be used for transmission of the DRS, may notify the DRS status information. That is, the small cell base station 10 at the timing of a change in the CC to be used for transmission of the DRS, may notify the DRS status information. Thus, the terminal device 20 can even when there is a change in the CC to be used for transmission of the DRS, which performs a measurement that target the appropriate CC, to reduce power consumption. Of course, the notification of the DRS arrangement information may be performed periodically. The period may be, for example, approximately 40 ms.
[0074]
　Notification of DRS status information, for example SI, means may be used, such as RRC signaling or PDCCH. However, the notification of the DRS status information, for example, such as PDCCH or SI, capable notification means instantaneously desirably used. Accordingly, even in a situation where the CC DRS is sent frequent switching, the terminal device 20 can switch the CC of measurement target instantaneously.
[0075]
　　(3) DRS change request of the CC to be used for transmission of
　the terminal device 20 (e.g., request 243) may request a change of the CC to be used for transmission of the DRS. For example, the terminal device 20 may notify the information indicating the CC in the off state to request the use of the transmission of the DRS to the small cell base station 10. That is, the terminal apparatus 20 may request the availability of DRS. Then, the small cell base station 10 (e.g., DRS transmission processing unit 151) based on a request from the terminal device 20 connected to the small cell may be selected CC to be used for transmission of the DRS. Thus, the CC of the terminal device 20 is desired to measurement, it is possible to provide the DRS is started immediately. Similarly, the terminal device 20, it is also possible to request provides stopping of DRS, that case it is possible to provide unnecessary DRS is stopped immediately. In the following, it referred to such a request with DRS request.
[0076]
　The terminal device 20, based on the CC configuration information may specify the CC of the DRS request. For example, the terminal device 20 includes a CC subjected to measurement, from among the one or more CC associated in CC configuration information specifying the CC to request provides start or stop the DRS. For example, if it contains information that indicates the CC1 ~ CC7 shown in FIG. 8 the CC configuration information, the terminal device 20 may request to transmit the DRS on at least one of CC2 ~ CC7 when measurement with CC1.
[0077]
　The DRS request, for example, may be notified together with the measurement report. In that case, the small-cell base station 10, based on both the measurement report and DRS request, it is possible to select whether to start providing DRS. Note that the both notifications may also mean a notice concurrent, may have means in series notifications, even if it means Notification included in the same or a different signal good.
[0078]
　　(4) CC on / off
　small-cell base station 10 (e.g., the transmission processing unit 151) selects the CC to or off state to the on state. For example, small-cell base station 10 may be selected based on the measurement results from the terminal device 20 connected to the small cell. Thus, for example, suitably it is possible to CC on or off in response to variations in the radio environment.

　An apparatus for operating a small cell,
　of the unit frequency band of one or more off-state in the plurality of unit frequency bands may be in the on state for uplink communications or downlink communications in the small cell, the OFF state the unit processor for selecting the unit frequency band of the off-state to be used for transmission of the discovery signal to allow measurement in the frequency band, the
device comprising a.
[Claim 2]
　Wherein the processing unit notifies the information indicative of the unit frequency band used for transmission of the discovery signal to terminals connected to the small cell, according to claim 1.
[Claim 3]
　Wherein, when there is a change in the unit frequency band used for transmission of the discovery signal, and notifies information indicating the unit frequency band used for transmission of the discovery signal to terminals connected to the small cell apparatus according to claim 2.
[Claim 4]
　Wherein the processing unit notifies the information indicative of the unit frequency band which can be the on state to the terminals connected to the small cell, according to claim 1.
[Claim 5]
　Wherein the unit frequency band which can be in the ON state is associated with the unit frequency band used for transmission of the discovery signal, apparatus according to claim 4.
[Claim 6]
　Wherein the said unit frequency band that can be turned on, and the unit frequency band used for transmission of the discovery signals correlated include bands that differ, according to claim 5.
[Claim 7]
　The notification to the, PDCCH (Physical Downlink Control Channel) or system information used, apparatus according to claim 2.
[8.]
　Wherein the processing unit performs the notification periodically, according to claim 2.
[Claim 9]
　Wherein the processing unit, the discovery signal to the unit frequency band used to transmit stepwisely to or reduce the increase in apparatus according to claim 1.
[Claim 10]
　Wherein the processing unit, based on said discovery signal measurement results for the terminal to be connected to the small cell, selects the unit frequency band used for transmission of the discovery signal, or to be or OFF state to the ON state selecting a unit frequency band, according to claim 1.
[Claim 11]
　Wherein the processing unit, based on a request from the terminal to be connected to the small cell, selects the unit frequency band used for transmission of the discovery signal, or the ON state or the unit frequency band which is turned off selecting, according to claim 1.
[Claim 12]
　Wherein the processing unit is different from the transmission period of the discovery signal for each of the unit frequency band, according to claim 1.
[Claim 13]
　Wherein the processing unit, as the unit frequency band bandwidth is small, to shorten the transmission period of the discovery signal, apparatus according to claim 12.
[Claim 14]
　The unit frequency band is a component carrier of the frequency band above 6 GHz, according to claim 1.
[Claim 15]
　A device for connecting the small cell,
　the selected in small cell from the unit frequency band of one or more off-state in the plurality of unit frequency bands may be in the on state for uplink communication or downlink communication the processing unit, which performs measurement for discovery signals transmitted by using the unit frequency band
device comprising a.
[Claim 16]
　Wherein the processing unit notifies the information indicative of the unit frequency band of the off state to request the use of the transmission of the discovery signal to the base station apparatus of claim 15.
[Claim 17]
　Wherein the processing unit notifies the information indicative of the unit frequency band required to the ON state to the base station apparatus of claim 15.
[Claim 18]
　Wherein the processing unit notifies the base station information indicating the unit frequency band according to the request together with the measurement report, according to claim 16.
[Claim 19]
　Among the unit frequency band of one or more off-state in the plurality of unit frequency bands may be in the on state for uplink communication or downlink communication in small cell, allow for measurement in the unit frequency band in the OFF state it, selecting by the processor the unit frequency band of the off-state to be used for transmission of the discovery signal for
methods including.
[Claim 20]
　Discovery that has been transmitted using the unit frequency band selected from the unit frequency band of one or more off-state in the plurality of unit frequency bands may be in the on state for uplink communication or downlink communication in a small cell it, performed by a processor of measurement for the signal
process including.