JP2016039581A - User apparatus, base station, and carrier aggregation setting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the delay occurring when setting carrier aggregation between base stations in a user device, in a communication system.SOLUTION: A user device for use in a mobile communication system including a first base station and a second base station communicating with the user device by carrier aggregation between base stations includes a reception unit for receiving a setting signal, for setting a cell used for the carrier aggregation between base stations, from the first base station, and a control unit for activating the cell, that was set based the setting signal received by the reception unit, and if there is the information indicating that acquisition of the predetermined notification information is not required, in the setting signal, transmitting a random access signal without performing the processing for acquiring predetermined notification information.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a broadcast information acquisition control technique used in a mobile communication system such as LTE.

  The LTE system employs carrier aggregation (CA) in which communication is performed using a plurality of carriers simultaneously with a predetermined bandwidth (maximum 20 MHz) as a basic unit. A carrier that is a basic unit in carrier aggregation is called a component carrier (CC).

  When CA is performed, a PCell (Primary cell) that is a highly reliable cell that ensures connectivity and a SCell (Secondary cell) that is an ancillary cell are set for the user apparatus UE. First, the user apparatus UE can connect to the PCell and add an SCell as necessary. The PCell is a cell similar to a single cell that supports RLM (Radio Link Monitoring), SPS (Semi-Persistent Scheduling), and the like.

  The SCell is a cell that is added to the PCell and set for the user apparatus UE. The addition and deletion of the SCell is performed by RRC (Radio Resource Control) signaling. Immediately after being set for the user apparatus UE, the SCell is a cell that is in an inactive state (deactivated state), and thus can be communicated (schedulable) only when activated.

  As shown in FIG. 1, in CA up to LTE Rel-10, a plurality of CCs under the same base station eNB are used.

  On the other hand, in Rel-12, dual connectivity has been proposed in which this is extended and simultaneous communication is performed using CCs under different base stations eNB to achieve high throughput (Non-patent Document 1). That is, in Dual connectivity, the UE performs communication using radio resources of two physically different base stations eNB at the same time.

  Dual connectivity is a kind of CA, also called Inter eNB CA (inter-base station carrier aggregation), and introduces Master-eNB (MeNB) and Secondary-eNB (SeNB). FIG. 2 shows an example of dual connectivity. In the example of FIG. 2, the dual connectivity (hereinafter, DC) is realized by the MeNB communicating with the user apparatus UE via CC # 1 and the SeNB communicating with the user apparatus UE via CC # 2.

  In DC, a cell group composed of cells (one or more) under the MeNB is defined as an MCG (Master Cell Group, master cell group), and a cell group composed of cells (one or a plurality) under the SeNB is defined as SCG ( (Secondary Cell Group, secondary cell group). A UL CC is set in at least one SCell of the SCGs, and a PUCCH is set in one of them. This SCell is called PSCell (primary SCell). The first SCell added in the SCG is the PSCell. Moreover, you may call PSCell a special cell (special cell).

3GPP TR 36.842 V12.0.0 (2013-12) 3GPP TS 36.331 V12.1.0 (2014-03)

  In the LTE system, when the user apparatus UE is located in a cell, the user apparatus UE acquires necessary information from broadcast information (System Information) (Non-Patent Document 2). The broadcast information is roughly classified into MIB (Master Information Block) and SIB (System Information Block), and the user apparatus UE first acquires the MIB, and then acquires various SIBs. The MIB includes dl-SystemBandwidth (system bandwidth), PHICH-Config (PHICH resource information, etc.), and systemFrameNumber (SFN, system frame number) as basic information necessary for being in the cell.

  The SFN included in the MIB is a number (0 to 1023) assigned to a frame composed of 10 subframes. The SFN is used, for example, to specify a transmission resource for PRACH (random access signal).

  In CA using one base station, it is considered that the SFN of each cell is uniform, but in DC using a plurality of base stations, the SFN is not necessarily uniform between the base station MeNB and the base station SeNB. It is assumed (it may be arranged as described later). FIG. 3 shows an example in which SFNs are not prepared. As illustrated in FIG. 3, for example, when a frame of SFN1 is transmitted from the base station MeNB at a certain point in time, a frame of SFN4 is transmitted in the base station SeNB.

  Therefore, in order to perform DC by communicating with the base station MeNB and the base station SeNB, the user apparatus UE needs to acquire the respective MIBs of the base station MeNB and the base station SeNB and grasp each SFN . Therefore, when the user apparatus UE performs DC by adding the base station SeNB (SCG) from a state in which the user apparatus UE is communicating with a single base station MeNB, the user apparatus UE acquires the MIB from the base station SeNB and grasps the SFN. There is a need to. Here, if the SCell is not in an active state, the user apparatus UE cannot read the DL signal from the SCell, and there is a delay of about several tens of ms in acquiring the MIB. There is a problem that a delay occurs when performing DC by adding SCG). This problem will be described with reference to FIG.

  FIG. 4 shows an outline of a procedure for adding an SCG (which may be one cell, that is, a PSCell) to the user apparatus UE. The user apparatus UE receives an RRC of an SCG addition instruction from the base station MeNB. A signal (RRC connection reconfiguration) is received (step 1). As the RRC process, the user apparatus UE performs decoding or the like for reading a parameter indicated by the RRC signal, but here an RRC process delay occurs. The user apparatus UE returns a completion response signal (RRC connection reconfiguration complete) (step 2) and activates the PSCell, but here a delay occurs. After activation of the PSCell, DL reception from the base station eNB becomes possible, and attempts to acquire the MIB. However, the MIB arrives periodically and generally requires multiple receptions for successful decoding. As shown, a MIB acquisition delay occurs. After acquiring the MIB, a random access procedure (RA procedure) is started in order to communicate with the base station SeNB (step 3). That is, first, a random access signal is transmitted to the base station SeNB by PRACH. After the RA procedure, data transmission / reception by scheduling can be performed.

  As described above, there is a problem that a delay occurs when setting the DC, the period until the scheduling start timing becomes longer, and the instantaneous interruption time becomes longer.

  The present invention has been made in view of the above points, and it is an object of the present invention to provide a technique capable of reducing a delay that occurs when inter-base station carrier aggregation is set in a user apparatus in a mobile communication system. And

According to an embodiment of the present invention, the user apparatus used in a mobile communication system comprising a first base station and a second base station that communicate with the user apparatus by inter-base station carrier aggregation,
A receiving unit that receives a setting signal for setting a cell to be used for inter-base station carrier aggregation from the first base station;
Activates a cell set based on the setting signal received by the receiving unit, and acquires the predetermined broadcast information when there is information indicating that acquisition of the predetermined broadcast information is unnecessary in the setting signal There is provided a user apparatus including a control unit that transmits a random access signal without performing the processing.

Moreover, according to the embodiment of the present invention, the user apparatus used in a mobile communication system including a first base station and a second base station that communicate with the user apparatus by inter-base station carrier aggregation. ,
Before receiving a setting signal for setting a cell used for inter-base station carrier aggregation from the first base station, an acquisition unit for acquiring predetermined broadcast information in the cell;
A control unit that receives the setting signal from the first base station, activates a cell set based on the setting signal, and transmits a random access signal using the predetermined broadcast information acquired by the acquiring unit; A user device is provided.

Moreover, according to the embodiment of the present invention, the user apparatus used in a mobile communication system including a first base station and a second base station that communicate with the user apparatus by inter-base station carrier aggregation. ,
A management table for storing difference information of system frame numbers between the cell of the first base station and the cell of the second base station;
The difference information stored in the management table is received from the first base station by receiving a setting signal for setting a cell used for carrier aggregation between the base stations, activating the cell set based on the setting signal. And a control unit that transmits a random access signal using the user apparatus.

Moreover, according to the embodiment of the present invention, it can be used as the first base station in a mobile communication system including a first base station and a second base station that communicate with a user apparatus by inter-base station carrier aggregation. A base station,
When a system frame number is synchronized between the first base station and the second base station, it is determined that acquisition of predetermined broadcast information by the user apparatus is unnecessary, and the first base station And a determination unit that determines that acquisition of predetermined broadcast information by the user device is necessary when the system frame number is not synchronized between the second base station and the second base station;
Based on the determination result by the determination unit, a transmission unit for transmitting the setting signal to the user apparatus, including whether or not to acquire predetermined broadcast information, in a setting signal for setting a cell used for carrier aggregation between base stations A base station is provided.

Moreover, according to the embodiment of the present invention, it can be used as the first base station in a mobile communication system including a first base station and a second base station that communicate with a user apparatus by inter-base station carrier aggregation. A base station,
Before transmitting a setting signal for setting a cell used for inter-base station carrier aggregation, an acquisition instruction transmission unit that transmits an instruction to acquire predetermined broadcast information in the cell to the user apparatus;
After receiving a completion report for the acquisition instruction, a base station is provided that includes a setting signal transmission unit that transmits the setting signal to the user apparatus.

Moreover, according to the embodiment of the present invention, it can be used as the first base station in a mobile communication system including a first base station and a second base station that communicate with a user apparatus by inter-base station carrier aggregation. A base station,
A management table for storing difference information of system frame numbers between the cell of the first base station and the cell of the second base station;
A transmission unit that includes the difference information stored in the management table in a setting signal for setting a cell used for carrier aggregation between the base stations, and that transmits a setting signal including the difference information to the user apparatus. A base station is provided.

Moreover, according to the embodiment of the present invention, the user apparatus used in the mobile communication system including the first base station and the second base station that communicate with the user apparatus by inter-base station carrier aggregation is executed. A carrier aggregation setting method,
Before receiving a setting signal for setting a cell used for inter-base station carrier aggregation from the first base station, an acquisition step of acquiring predetermined broadcast information in the cell;
Receiving the setting signal from the first base station, activating a cell set based on the setting signal, and transmitting a random access signal using the predetermined broadcast information acquired by the acquiring step; A carrier aggregation setting method is provided.

  According to the embodiment of the present invention, in a mobile communication system, it is possible to reduce a delay that occurs when inter-base station carrier aggregation is set in a user apparatus.

It is a figure which shows CA to Rel-10. It is a figure which shows the example of Dual connectivity. It is a figure for demonstrating the shift | offset | difference of SFN. It is a figure for demonstrating a subject. It is a block diagram of the communication system in embodiment of this invention. It is a figure which shows the example of a sequence of the control example 1 in 1st Embodiment. It is a figure for demonstrating the example in the case of performing DC with three base stations in the control example 1. FIG. It is a flowchart of the process of the base station MeNB in the example 1 of control. It is a flowchart of the process of the user apparatus UE in the example 1 of control. It is a figure which shows the example of a sequence of the example 2 of control in 1st Embodiment. It is a figure for demonstrating the modification in the control example 2. FIG. It is a flowchart of the process of the base station MeNB in the example 2 of control. It is a flowchart of a process of the user apparatus UE in the control example 2. It is a figure which shows the example of a sequence of the control example 3 (when a base station has a management table) in 1st Embodiment. It is a figure which shows the example of the information stored in a management table. 10 is a flowchart illustrating a processing example in Control Example 3. It is a figure which shows the example of a sequence of the control example 3 (when a user apparatus has a management table) in 1st Embodiment. It is a block diagram of the base station in 1st Embodiment. It is a block diagram of the user apparatus in 1st Embodiment. It is a figure which shows the example 1 of a sequence of the process in 2nd Embodiment. It is a figure which shows the example 2 of a sequence of the process in 2nd Embodiment. It is a figure which shows the example 3 of a sequence of the process in 2nd Embodiment. It is a flowchart which shows the operation example of the user apparatus in 2nd Embodiment. It is a block diagram of the base station in 2nd Embodiment. It is a block diagram of the user apparatus in 2nd Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. The embodiment described below is only an example, and the embodiment to which the present invention is applied is not limited to the following embodiment. Further, although the present embodiment is directed to an LTE mobile communication system, the present invention is not limited to LTE and can be applied to other mobile communication systems. In the present specification and claims, unless otherwise specified, the term “LTE” is used to mean 3GPP Rel-12 or Rel-12 or later.

(System configuration)
FIG. 5 is a diagram illustrating a configuration example of a communication system according to the embodiment of the present invention (common to the first and second embodiments). As illustrated in FIG. 5, the communication system includes a base station MeNB and a base station SeNB that are connected to the core network 10, respectively, and enables DC between the user apparatus UE. Further, the base station MeNB and the base station SeNB can communicate with each other through, for example, an X2 interface.

  In the communication system shown in FIG. 5, for example, PCell and SCell (including PSCell) can be set with MCG as a macro cell and SCG as a small cell. Although addition, deletion, and setting change of SCell (including PSCell) in the user apparatus UE are performed by RRC signaling from the base station MeNB, the present invention is not limited to this.

  Below, 1st Embodiment and 2nd Embodiment are described. In the first embodiment, a mode for eliminating a delay related to MIB acquisition at the time of DC setting (including change of the DC configuration) will be described. In the second embodiment, when MIB acquisition cannot be performed. A mode in which the DC setting procedure is quickly stopped and the delay is eliminated as a result will be described.

  Note that the first embodiment and the second embodiment can be applied in combination, both of which are embodiments of the present invention. For example, by applying the second embodiment to the first embodiment, it is necessary to acquire the MIB while eliminating the delay related to the MIB acquisition, and when the MIB cannot be acquired, the DC setting procedure Can be stopped quickly. In addition, by applying the first embodiment to the second embodiment, it is possible to quickly stop the DC setting procedure when MIB acquisition cannot be performed, for example, to stop using the old SeNB. Accordingly, when a new SeNB is added, DC setting can be performed with a small delay.

(First embodiment)
First, a first embodiment will be described. In the first embodiment, the control example 1 instructs the user apparatus UE from the network whether the MIB acquisition is necessary, the control example 2 performs the MIB acquisition procedure prior to the DC setting procedure, and the MIB information (specifically, SFN). There is a control example 3 that holds information) in advance, and each will be described below.

<Control example 1 of the first embodiment>
For example, when the control for synchronization is performed between the base station MeNB and the base station SeNB, the SFN may be synchronized (equipped) between the base station MeNB and the base station SeNB. . In such a case, since the user apparatus UE can use the SFN of the base station MeNB (MCG) as the SFN of the base station SeNB (SCG), the user apparatus UE needs to acquire the MIB of the base station SeNB. Therefore, the MIB acquisition procedure can be omitted.

  Therefore, in the control example 1, the base station MeNB notifies the user apparatus UE of necessity of MIB acquisition in the RRC signal that sets DC.

  As described above, the MIB includes dl-SystemBandwidth (system bandwidth) and PHICH-Config (PHICH resource information, etc.) in addition to SFN, both of which are important information. The base station MeNB can acquire from the base station SeNB and can notify the user apparatus UE. In this embodiment, when MIB is not acquired, dl-SystemBandwidth and PHICH-Config can be notified in this way.

  On the other hand, in order to grasp the SFN of the frame received at each time, it is necessary to actually receive the frame, so unless there is another standard, the SFN (timing information) of a certain base station eNB is It cannot be grasped unless a signal (MIB) is received from the station eNB.

  FIG. 6 is a diagram illustrating a sequence example of the control example 1 in the first embodiment. The procedure of the control example 1 will be described with reference to FIG. The user apparatus UE transmits, for example, a measurement report (Measurement report) including a quality (strength) measurement result of a cell that is a candidate for a cell constituting the SCG to the base station MeNB (step 101).

  The base station MeNB determines the DC setting for adding the base station SeNB (SCG) to the user apparatus UE, transmits a SeNB addition request (SeNB addition request) to the base station SeNB (step 102), and the base station SeNB confirms A response (SeNB addition request ack) is returned (step 103). In addition, in the SeNB addition request in Step 102, UE setting information, UE capability, and the like on the base station MeNB side are stored.

  The base station MeNB transmits an RRC signal (RRC connection reconfiguration) instructing addition of SCG (setting DC) to the user apparatus UE (step 104). In the control example 1, this RRC signal includes information on whether or not MIB acquisition is necessary. This is merely an example, and the MIB acquisition necessity may be notified separately from the RRC signal for setting the DC.

  The user apparatus UE that has received the RRC signal performs RRC processing (processing for setting SCG), and returns a completion signal (RRC connection reconfiguration complete) (step 105).

  When it is notified in step 104 that MIB acquisition is required, the user apparatus UE activates the SCG cell and then performs PRACH transmission (RA procedure) after performing the MIB acquisition procedure (step 106). In addition, although SCG may contain several cells, in this Embodiment, SCG assumes that it is comprised from PSCell. In addition, even when a plurality of cells are included, it is assumed that SFNs are prepared in the SCG. Therefore, as for SFN, it is only necessary to know MIB information of PSCell which is one cell.

  On the other hand, when it is notified that MIB acquisition is not required, the user apparatus UE performs PRACH transmission (RA procedure) using the SFN of the MeNB as the SFN of the SeNB without activating the MIB acquisition procedure after activating the SCG. (Step 106). After the RA procedure, a SeNB addition confirm is returned (step 107).

  As described above, when MIB acquisition is not necessary, the SFN is synchronized between the base station MeNB and the SeNB, and thus the user apparatus UE determines the SFN of the base station SeNB based on the SFN of the base station MeNB.

  In addition, as illustrated in FIG. 7, when DC is performed at 3 eNB or more (three in FIG. 7), when the third is already connected with 2 eNB, and MIB acquisition is not necessary. When notified, an eNB serving as an SFN criterion may be designated. In the example of FIG. 7, it is specified that the MeNB SFN is used as a reference. Moreover, when this designation | designated does not exist, the user apparatus UE is good also considering the SFN of MeNB as a reference | standard.

  According to the control example 1, when DC is set in the user apparatus UE, it is possible to shorten the time until the PRACH is transmitted to the base station SeNB.

<Operation flow>
FIG. 8 is a flowchart illustrating an operation example of the base station MeNB in the control example 1. As illustrated in FIG. 8, the base station MeNB receives a measurement report from the user apparatus UE (step 201). Based on the measurement report, the cell to be SCG (SeNB cell) is determined, and it is determined whether SFNs are prepared between the own cell (cell connected to user apparatus UE) and the cell to be the SCG (step) 202), if not, the user apparatus UE is instructed to perform MIB acquisition of the corresponding cell (step 203).

  FIG. 9 is a flowchart illustrating an operation example of the user apparatus UE in the control example 1. As shown in FIG. 9, the user apparatus UE transmits a measurement report (Measurement report) to the base station MeNB (step 301), and is instructed to set DC by the RRC signal from the base station MeNB (step 302). The RRC signal includes the necessity of MIB acquisition. The user apparatus UE sets the PSCell by the RRC process and activates the PSCell (Step 303). In step 303, the user apparatus UE can receive a DL signal from the base station SeNB.

  Subsequently, the user apparatus UE determines whether or not an instruction for MIB acquisition is received (step 304). If the instruction for MIB acquisition is received, the process proceeds to step 305, where MIB acquisition is performed, and SFN is set. Obtaining and performing PRACH transmission using SFN (predetermined broadcast information) (step 306).

<Control example 2 of the first embodiment>
Next, control example 2 will be described. In the control example 2, it is assumed that the user apparatus UE acquires the MIB of the base station SeNB independently of the DC setting by the RRC signal. In the control example 2, the time until the PRACH transmission can be shortened by performing the DC setting and the MIB acquisition procedure independently.

  FIG. 10 is a diagram illustrating a sequence example of the control example 2 in the first embodiment. Hereinafter, the sequence will be described, but the contents already described will be briefly described.

  The user apparatus UE transmits a measurement report (Measurement report) to the base station MeNB (step 401). The base station MeNB determines the DC setting for adding the SeNB, and transmits a SeNB addition request (SeNB addition request) to the base station SeNB (step 402).

  In the control example 2, the base station MeNB transmits an MIB acquisition instruction (MIB acquisition indication) to the user apparatus UE (step 403). The MIB acquisition instruction includes, for example, a cell ID that is predicted to be set in the PSCell among the cells that have received the measurement report (any information that can identify the cell may be used). The user apparatus UE that has received the MIB acquisition instruction acquires the MIB of the specified cell, for example, according to the instruction from the base station MeNB, calculates the SFN deviation (difference) between the base station MeNB and SeNB, and The difference is held, and the value of the difference or MIB acquisition complete is returned (step 404). The value of the difference may be included in the signal of MIB acquisition complete. Here, the base station MeNB may retransmit the MIB acquisition instruction or cancel the DC setting when there is no response from the user apparatus UE within a predetermined period after transmitting the MIB acquisition instruction. .

  When the base station MeNB receives a confirmation response (SeNB addition request ack from the base station SeNB (step 405), the base station MeNB transmits a DC setting RRC signal (RRC connection reconfiguration) to the user apparatus UE (step 406).

  After the RRC process and the completion response (step 407), the user apparatus UE activates the PSCell and performs PRACH transmission using the already acquired MIB information (specifically, SFN difference information) (step 408). . After the RA procedure, a SeNB addition confirm is returned (step 409).

<Modification of Control Example 2>
Next, a modification of the control example 2 will be described. The basic procedure is the same as in FIG. In the following, description will be made with reference to FIG. 11 with a focus on differences from the procedure shown in FIG.

  In the control example 2, MIB acquisition is performed when a measurement report is reported (eg, before step 401 in FIG. 10). Here, the MIB is basically acquired for the cell targeted for measurement, but more specifically, for example, the cell targeted for MIB acquisition has the best quality (RSRP / RSRQ) cell (best Or the top several), or several from the earliest timing to report the measurement report, or all the cells to be reported in the measurement report.

  After step 401 of FIG. 10, the base station MeNB determines the DC setting and transmits a SeNB addition request (SeNB addition request) to the base station SeNB (step 402).

  In the modified example of the control example 2, when the base station MeNB determines that the user apparatus UE has already acquired the MIB for the cell predicted to be set as the PSCell at the time of step 402, the MIB acquisition instruction If it is determined that the ID has not been acquired yet, an MIB acquisition instruction is issued. The procedure for issuing an MIB acquisition instruction is as shown in steps 403 and 404 of FIG.

  An example of determining whether or not to perform the MIB acquisition instruction will be described with reference to FIG. In the example of FIG. 11, for example, it is assumed that the user apparatus UE has acquired the MIBs of the cell 1, the cell 3, and the cell 4 with a predetermined logic (for example, top several pieces with good quality). Acquiring the MIB here means calculating and maintaining a difference (difference) between the SFN of the acquisition target cell and the SFN of the MeNB cell.

  In FIG. 11, the base station MeNB that has received the measurement report (including at least cell 1, cell 2, cell 3, and cell 4) decides to set DC, and the user equipment UE performs MIB acquisition cell selection. Therefore, a cell that can be determined to have acquired the MIB is specified with the same logic as that used for the purpose. Here, cell 1, cell 3, and cell 4 are specified. In addition, the base station MeNB determines a cell that is predicted to be set in the PSCell. The cell to be set in the PSCell is determined by the SeNB from the viewpoint of not only the quality but also the degree of congestion, for example, but the base station MeNB uses the same logic as that used in the SeNB to receive the measurement report. Among these, the cell predicted to be set to PSCell is determined. In the example of FIG. 11, it is predicted that the cell 2 is set to PSCell. On the other hand, since the cells predicted to have acquired the MIB are the cells 1, 3, and 4, the cell 2 is not included therein. Therefore, it is determined that the MIB that is predicted to be set as the PSCell has not been acquired, and in this case, an MIB acquisition instruction that instructs to acquire the MIB of the cell 2 is transmitted to the user apparatus UE.

  In the modified example, when the MIB acquisition instruction is performed, the processing after step 403 is the same as the basic processing of the control example 2 described with reference to FIG. Note that, when the MIB acquisition instruction is received for the cell of the MIB even though the MIB is acquired in the user apparatus UE, the previously acquired SFN difference information may be discarded.

  In the modified example, when the MIB acquisition instruction is not performed, the process is performed by removing steps 403 and 404 from FIG. In this case, the user apparatus UE uses the SNF difference information acquired in advance to determine the SFN of the SeNB from the SFN of the MeNB and perform PRACH transmission.

  In step 401 in FIG. 10, it may be notified which cell has acquired the MIB.

<Operation flow>
Next, an operation flow of the base station MeNB in the control example 2 (basic example) will be described with reference to FIG. When the base station MeNB receives the measurement report from the user apparatus UE (step 501), the base station MeNB determines the DC setting and transmits an MIB acquisition instruction to the user apparatus UE (step 502). Moreover, the base station MeNB transmits a SeNB addition request (SeNB addition request) to the base station SeNB (step 503). When receiving a confirmation response (SeNB addition request ack) from the base station SeNB, the base station MeNB transmits a DC setting RRC signal (RRC connection reconfiguration) to the user apparatus UE (step 504).

  Next, with reference to FIG. 13, the operation example of the user apparatus UE in the control example 2 is demonstrated. The user apparatus UE transmits a measurement report (Measurement report) to the base station MeNB (step 601), and receives an MIB acquisition instruction from the base station MeNB that has determined the DC setting (step 602). The user apparatus UE acquires the MIB according to the instruction, and holds the difference information with the SFN of the MeNB (step 603). The user apparatus UE which received the RRC signal of DC setting activates PSCell (step 604), and performs PRACH transmission (step 605).

<Control example 3 of the first embodiment>
Next, control example 3 will be described. In Control Example 3, MIB information (specifically, SFN difference information between cells) is held in the base station eNB or the user apparatus UE, and MIB acquisition at the time of DC setting is not performed by using the held information. In addition, the time until PRACH transmission in the DC setting is shortened.

  First, an example of holding the SFN difference information in the base station eNB will be described with reference to the sequence diagram of FIG. The base station eNB shown in FIG. 14 is a base station that has a function of providing DC and can be a MeNB or SeNB with respect to the user apparatus UE.

  In this example, the user apparatus UE acquires the SFN difference information between the two cells by acquiring the MIB in each of the two cells, and notifies the base station eNB of the information to thereby notify the base station eNB between the cells. A management table composed of SFN difference information is created.

  In step 701 of FIG. 14, an SFN information report trigger for performing the above-described report is generated. This trigger may be, for example, the MIB acquisition instruction described in Control Example 2, or may be at the time of MIB measurement at the time of conventional DC setting. Furthermore, for example, when the user apparatus UE changes from the IDLE state to the CONNECTED state, when the cell changes from inactive to active, it may be at the time of handover or at the time of reconnection. In addition, there may be a report instruction from the base station eNB.

  Note that if the SFN difference value is reported uniformly when the trigger occurs, the transmission of other data may be delayed due to the report in the case of a cell with poor quality. The report may be limited to a case where a predetermined quality or higher is ensured in the connected cell.

  The SFN difference value is acquired by the trigger. For example, if this is a report in the case of DC, the difference value between the SFN that can be acquired from the MIB of the MCG (example: PCell) and the SFN that can be acquired from the MIB of the SCG (example: PSCell) is acquired. If a difference value already exists at the time of trigger occurrence, there is no need to obtain it here.

  Then, in step 702 of FIG. 14, the user apparatus UE transmits SFN difference information to the base station eNB (for example, MeNB) of the connected cell. This difference information includes the difference value between the ID of the target two cells and the SFN.

  In step 703, the base station eNB that has received the SFN difference information stores the SFN difference information in the management table. Or when SFN difference information is already acquired about the group of the said cell, storage here becomes the position of "update."

  FIG. 15 shows an example of a management table possessed by the base station eNB. As shown in FIG. 15, SFN differences (shifts) are stored for each combination of cells. As an example, the difference of 3 in the cell 1 -cell 2 set indicates that the SFN of the cell 1 is 3 larger than the SFN of the cell 2 in the frame at the same time. That is, in this case, for example, when the SFN of the cell 2 is derived using the SFN of the cell 1 as a reference, the SFN obtained by subtracting 3 from the SFN of the cell 1 may be used as the SFN of the cell 2. In addition, the date and time (time stamp) of the difference information may be attached to the information in the management table. Thereby, as will be described later, when the management table is exchanged between the base stations, the oldest information can be overwritten with the new one, so that the newest information can be obtained.

  FIG. 14B shows a phase in which the management table created in this way is used in DC. As illustrated in FIG. 14B, this case is a case where the user apparatus UE performs DC with the base stations MeNB and SeNB. Here, the base station MeNB has the above-described management table, and the base station MeNB includes the SFN difference value between the MeNB cell and the SeNB cell regarding the DC in the DC setting RRC signal to the user apparatus. , Including the MIB acquisition unnecessary instruction (step 711). For example, in the management table illustrated in FIG. 15, when the MeNB cell and the SeNB cell are the cell 1 and the cell 2, 3 is notified as the difference value. The MIB acquisition unnecessary instruction may not be included. In this case, the user apparatus UE can determine that MIB acquisition is unnecessary by receiving the difference value.

  After that, through the RRC process, the user apparatus UE returns a response (complete) (step 712), and performs PRACH transmission through activation of PSCell (step 713).

  Since there may be a change in the SFN deviation between the base stations eNB during operation, it is desirable to update the values once recorded in the management table as needed. Therefore, the base station eNB may periodically report SFN difference information to the user apparatus UE.

  Moreover, the information of a management table may be mutually shared between eNBs using communication between base stations (example: X2 I / F). Furthermore, when information larger than the size that can be managed by the base station eNB has to be registered in the management table, the oldest information (creation or update timing is old) may be deleted. Or you may delete the information of cell ID (example: PCI) with the least frequency of performing DC.

  FIG. 16 is a flowchart illustrating an operation example of the base station eNB in the control example 3. This is an example of notifying the SFN difference information when the base station eNB sets DC as the MeNB. As shown in FIG. 16, after the base station eNB receives the measurement report from the user apparatus UE (step 801) and determines the DC setting, the management table determines whether or not the SFN difference value between cells used as DC is included. Judgment is made by reference (step 802). If there is an SFN difference value, the SFN difference value is included in, for example, a DC setting RRC signal and transmitted to the user apparatus UE.

  Next, an example of holding the management table (SFN difference information) in the user apparatus UE will be described with reference to the sequence diagram of FIG.

  In FIG. 17A, an SFN information acquisition trigger is generated (step 901). This trigger may be the same as the trigger for reporting the SFN difference information described above. Moreover, it is good also as a trigger in response to the instruction | indication of SFN difference information acquisition from the base station eNB. When the trigger is generated, the user apparatus UE acquires SFN difference information between cells capable of MIB reception (step 902) and stores it in the management table (step 903). If it is already stored in the management table, this process is positioned as an update. The contents of the management table are the same as those shown in FIG.

  FIG. 17A is a sequence example when DC setting is performed using the management table created as described above. Note that this sequence mainly indicates processing between the UE and the MeNB.

  In step 911, the user apparatus UE transmits a measurement report to the base station MeNB. At this time, the user apparatus UE refers to the management table, and when it has an SFN difference value between the cell related to the measurement and the cell (connected cell) of the MeNB, the MIB acquisition need not be performed for each cell in the measurement report. Information to indicate can be included. Note that information indicating that MIB acquisition is unnecessary may not be included.

  In Step 912, the base station MeNB transmits a DC setting RRC signal to the user apparatus UE. Here, based on the above-described information indicating that MIB acquisition is not required, the RRC signal may include an MIB acquisition unnecessary instruction.

  The user apparatus UE performs SRC addition by performing RRC processing, returns a response (Complete) (step 913), activates the PSCell, and acquires the MIB without acquiring the MIB, and the PCell The PFN is transmitted by obtaining the SFN of the PSCell from the SFN (step 914).

(Device configuration example)
Hereinafter, configuration examples of the user apparatus UE and the base station eNB that execute the operation of the first embodiment (including all control examples) will be described.

<Configuration example of base station eNB>
FIG. 18 shows a functional configuration diagram of a base station eNB (which can be used for both MeNB and SeNB) according to the present embodiment. As illustrated in FIG. 18, the base station eNB includes a DL signal transmission unit 101, a UL signal reception unit 102, a DC control unit 104, an inter-base station communication control unit 104, an SFN information acquisition unit 105, and a management table storage unit 106. . FIG. 18 shows only functional units particularly related to the embodiment of the present invention in the base station eNB, and also has a function (not shown) for operating as a base station in a mobile communication system compliant with LTE. Is. Further, the functional configuration shown in FIG. 18 is merely an example. As long as the operation according to the present embodiment can be performed, the function classification and the name of the function unit may be anything.

  The DL signal transmission unit 101 includes a function of generating and wirelessly transmitting various physical layer signals from higher layer signals to be transmitted from the base station eNB. The UL signal receiving unit 102 includes a function of wirelessly receiving various signals from the user apparatus UE and acquiring a higher layer signal from the received physical layer signal.

  The DC control unit 103 performs processing such as setting / changing / managing DC, and performs control in each control example, such as determining whether or not an MIB acquisition instruction is necessary and setting an RRC signal such as an MIB acquisition instruction. The inter-base station communication control unit 104 transmits / receives information to / from another base station (eg, MeNB / SeNB). The SFN information acquisition unit 105 acquires SFN information in the control example 3, and stores it in the management table. The management table storage unit 106 stores a management table.

<Configuration example of user apparatus UE>
FIG. 19 shows a functional configuration diagram of the user apparatus UE according to the present embodiment. As illustrated in FIG. 19, the user apparatus UE includes a DL signal reception unit 201, a UL signal transmission unit 202, a DC control unit 203, an MIB information acquisition unit 204, an SFN information acquisition unit 205, and a management table storage unit 206. Note that FIG. 19 shows only functional units that are particularly related to the embodiment of the present invention in the user apparatus UE, and has at least a function (not shown) for performing an operation based on LTE. Further, the functional configuration shown in FIG. 19 is merely an example. As long as the operation according to the present embodiment can be performed, the function classification and the name of the function unit may be anything.

  The DL signal reception unit 201 includes a function of wirelessly receiving various signals from the base station eNB and acquiring a higher layer signal from the received physical layer signal. The UL signal transmission unit 202 includes a function of generating and wirelessly transmitting various physical layer signals from higher layer signals to be transmitted from the user apparatus UE.

  The DC control unit 203 performs processing such as setting / changing / managing DC, and performs control in each control example such as determination of necessity of acquisition based on an MIB acquisition instruction. The MIB information acquisition unit 204 performs processing for acquiring an MIB. The SFN information acquisition unit 205 acquires SFN information in Control Example 3, and reports it to the base station eNB or stores it in the management table. The management table storage unit 206 stores a management table.

(Second Embodiment)
Next, a second embodiment will be described. For example, as described with reference to FIG. 4, when the SCG is added to the user apparatus UE in the DC setting, if the user apparatus UE cannot acquire the MIB, the user apparatus UE transmits the PRACH to the SeNB side. Cannot send. Therefore, communication is not possible. In such an error case, the NW needs to cancel the DC (SCG) setting.

  As a countermeasure example for such a case, when the base station SeNB transmits the SeNB addition request ack to the base station MeNB, if the PRACH transmission from the user apparatus UE cannot be confirmed within a predetermined period of time, the DC setting is stopped. Is assumed.

  However, since the timer value is set to a safe level in anticipation of the worst case to some extent, the user apparatus UE must wait for an instruction from the NW even in a case where it is found that the MIB cannot be acquired, and unnecessary instantaneous interruption. Time occurs.

  In the second embodiment, in order to avoid the unnecessary momentary interruption time as described above, when the user apparatus UE cannot acquire the MIB for a predetermined period at the time of DC setting (same when changing), The fact is reported to the base station MeNB. As a result, it is possible to take measures such as stopping DC setting without waiting for the timer on the NW side to expire, and to reduce instantaneous interruption.

  Note that “MIB” in the second embodiment may target SFN in the MIB information. In this case, for the MIB information other than SFN, for example, the MeNB notifies the user apparatus UE with an RRC signal as described above.

  Also in the second embodiment, the SFN difference value notification by the management table holding described in the first embodiment, the MIB acquisition instruction, and the like can be applied. That is, the items described in the first embodiment can be implemented in combination with the second embodiment.

  With reference to FIGS. 20-22, the example of a sequence of the process at the time of DC setting in 2nd Embodiment is demonstrated.

  In FIG. 20, the processing from the measurement report in step 1001 to the RRC connection reconfiguration complete in step 1005 is the same as the processing in the first embodiment described in FIG. However, here, there is no need for information on the necessity of MIB acquisition that existed in the example of FIG. Of course, this may be present. When this exists, the following processing corresponds to the case where MIB acquisition is required.

  In the second embodiment, when the RRC process is completed and the RRC connection reconfiguration complete is returned in Step 1005, the user apparatus UE sets the MIB acquisition timer (Step 1006). The timer value set here may be notified from the base station MeNB to the user apparatus UE by RRC connection reconfiguration in step 1004 or may be notified by another signal.

  The user apparatus UE activates the PSCell set in the RRC process, and the activation process is completed in a predetermined time. The MIB acquisition timer is started (time measurement is started) at the timing when activation of this PSCell is started or when it is completed.

  When the activation of the PSCell is completed, the user apparatus UE performs (trys) MIB acquisition. Although the MIB is transmitted a plurality of times, the MIB acquisition timer may be started at the timing when the first MIB is acquired (the MIB information is not necessarily successfully decoded).

  If the MIB information can be acquired before the timer expires (predetermined time elapses), the timer is stopped and PRACH transmission is performed. If the MIB cannot be acquired before the MIB acquisition timer expires (that is, when the timer expires), The base station MeNB is notified. FIG. 20 shows an example in which the MIB cannot be acquired before the MIB acquisition timer expires, and a report indicating that the MIB cannot be acquired is sent to the base station MeNB in step 1007.

  In the example of FIG. 20, the base station MeNB that has received the MIB acquisition failure report transmits a signal (for example, RRC connection reconfiguration) instructing to stop DC setting to the user apparatus UE. Note that such a signal may not be transmitted.

  When the timer expires, the user equipment UE may stop signal reception in the PSCell using the timer expiration as a trigger or the reception of the DC setting stop signal as a trigger, or forcibly deactivate the cell. May be used.

  In step 1007, the base station MeNB that has received the MIB acquisition impossibility report accompanying the expiration of the timer may perform the operations shown in FIG. 21 and FIG.

  In the example of FIG. 21, after step 1007, the base station MeNB acquires MIB information from the base station SeNB (step 1010), and notifies the user apparatus UE of this (step 1011). In this case, for example, it is assumed that the base station SeNB holds the management table described above, and the acquired MIB information is SFN difference information between the MCG and the SCG.

  Thereby, the user apparatus UE can implement PRACH transmission, without trying MIB acquisition from SeNB (step 1012).

  In the example of FIG. 22, after Step 1007, the base station MeNB instructs the user apparatus UE to acquire MIB (Step 1020). This instruction may be performed using an RRC signal or another signal. Receiving the instruction, the user apparatus UE starts the MIB acquisition timer again and tries to acquire the MIB. In the example of FIG. 22, MIB acquisition is successful before the timer expires (step 1021), and PRACH transmission is performed (step 1022).

  In the example of FIG. 20, the user apparatus UE may continue searching for the MIB even if the timer expires and the MIB acquisition impossible report is transmitted. Then, when the MIB can be acquired before receiving the DC setting cancellation instruction from the base station MeNB, the procedure may be shifted to the PRACH transmission procedure. At this time, it may be reported to the base station MeNB that the MIB has been acquired. Accordingly, the base station MeNB can not transmit a DC setting stop instruction.

  In addition, the MIB acquisition impossibility report method in Step 1007 is not limited to a specific method, but a dedicated control signal may be defined for this report, or RLF (Radio Link Failure, radio link failure) May be reported as Although the cause is defined in the RLF, the cause when the RLF is used as the MIB acquisition impossibility report may be a conventional RA failure, or a new MIB acquisition failure may be defined.

  FIG. 23 shows an operation flowchart of the user apparatus UE in the second embodiment. The user apparatus UE transmits a measurement report (step 1101), and is instructed to set DC by an RRC signal (step 1102). The RRC signal includes a timer value, and the timer value is set in the MIB acquisition timer. In this example, when the user apparatus UE completes the activation of the PSCell (step 1103), the MIB acquisition timer is started (step 1104).

  If the MIB acquisition is completed before the timer expires (Yes in Step 1105), the user apparatus UE performs PRACH transmission (Step 1106). On the other hand, if the MIB acquisition is not completed before the timer expires (No in step 1105), the user apparatus UE performs a MIB acquisition impossibility report (in this example, RLF) (step 1107).

(Device configuration example)
Hereinafter, configuration examples of the user apparatus UE and the base station eNB that execute the operation of the second embodiment (the operations of all the examples of the second embodiment) will be described.

<Configuration example of base station eNB>
FIG. 24 shows a functional configuration diagram of a base station eNB (which can be used for both MeNB and SeNB) according to the present embodiment. As illustrated in FIG. 24, the base station eNB includes a DL signal transmission unit 301, a UL signal reception unit 302, a DC control unit 303, an inter-base station communication control unit 304, an MIB information acquisition unit 305, and a MIB acquisition unavailable time processing unit 306. including. Note that FIG. 24 shows only the functional units particularly related to the embodiment of the present invention in the base station eNB, and also has a function (not shown) for operating as a base station in a mobile communication system compliant with LTE. Is. The functional configuration shown in FIG. 24 is only an example. As long as the operation according to the present embodiment can be performed, the function classification and the name of the function unit may be anything.

  The DL signal transmission unit 301 includes a function of generating and wirelessly transmitting various physical layer signals from higher layer signals to be transmitted from the base station eNB. The UL signal reception unit 302 includes a function of wirelessly receiving various signals from the user apparatus UE and acquiring a higher layer signal from the received physical layer signal.

  The DC control unit 303 performs processing such as DC setting / change / management. The inter-base station communication control unit 304 transmits / receives information to / from another base station (eg, MeNB / SeNB). The MIB information acquisition unit 305 performs processing such as acquiring MIB information from another base station, for example. The MIB acquisition impossibility processing unit 306 performs control when receiving a MIB acquisition impossibility report from the user apparatus UE.

<Configuration example of user apparatus UE>
FIG. 25 shows a functional configuration diagram of user apparatus UE according to the present embodiment. As illustrated in FIG. 25, the user apparatus UE includes a DL signal reception unit 401, a UL signal transmission unit 402, a DC control unit 203, an MIB information acquisition unit 404, and an MIB acquisition determination unit 405. Note that FIG. 25 shows only functional units that are particularly related to the embodiment of the present invention in the user apparatus UE, and also has a function (not shown) for performing at least LTE-compliant operation. In addition, the functional configuration illustrated in FIG. 25 is merely an example. As long as the operation according to the present embodiment can be performed, the function classification and the name of the function unit may be anything.

  The DL signal reception unit 401 includes a function of wirelessly receiving various signals from the base station eNB and acquiring a higher layer signal from the received physical layer signal. The UL signal transmission unit 402 includes a function of generating various physical layer signals from a higher layer signal to be transmitted from the user apparatus UE and wirelessly transmitting the signals.

  The DC control unit 403 performs processing such as setting / changing / managing DC, and also performs MIB acquisition impossibility report control based on timer expiration as described above. The MIB information acquisition unit 404 performs processing for acquiring an MIB. The MIB acquisition determination unit 405 manages a timer and determines whether or not MIB acquisition has been completed before expiration.

  Note that the base station eNB may have both the functions of the first embodiment and the second embodiment, and the user apparatus UE has the functions of both the first embodiment and the second embodiment. May be provided.

  In this Embodiment, it is the said user apparatus used in the mobile communication system provided with the 1st base station and 2nd base station which communicate with a user apparatus by the carrier aggregation between base stations, Comprising: Said 1st base A receiving unit that receives a setting signal for setting a cell to be used for inter-base station carrier aggregation from a station, and a cell that is set based on the setting signal received by the receiving unit, and activates the cell in the setting signal And a control unit that transmits a random access signal without performing processing for acquiring the predetermined broadcast information when there is information indicating that acquisition of the predetermined broadcast information is unnecessary. Is provided. With this configuration, in a mobile communication system, it is possible to reduce a delay that occurs when inter-base station carrier aggregation is set in a user apparatus.

  Moreover, in this Embodiment, it is the said user apparatus used in the mobile communication system provided with the 1st base station and 2nd base station which communicate with a user apparatus by the carrier aggregation between base stations, Before receiving a setting signal for setting a cell to be used for inter-base station carrier aggregation from the base station, an acquisition unit for acquiring predetermined broadcast information in the cell, and the setting from the first base station A user apparatus comprising: a control unit that receives a signal, activates a cell set based on the setting signal, and transmits a random access signal using the predetermined broadcast information acquired by the acquisition unit Is provided. With this configuration, in a mobile communication system, it is possible to reduce a delay that occurs when inter-base station carrier aggregation is set in a user apparatus.

  For example, when the acquisition unit receives an instruction to acquire the predetermined broadcast information from the first base station, the acquisition unit acquires the predetermined broadcast information based on the acquisition instruction. With this configuration, the user apparatus can acquire predetermined notification information based on a clear trigger, and can appropriately acquire predetermined notification information before receiving a setting signal.

  The predetermined broadcast information is, for example, a system frame number in MIB. With this configuration, it is possible to shorten the delay related to acquisition of the system frame number.

  Moreover, in this Embodiment, it is the said user apparatus used in the mobile communication system provided with the 1st base station and 2nd base station which communicate with a user apparatus by the carrier aggregation between base stations, A management table storing difference information of system frame numbers between the cell of the base station and the cell of the second base station, and a cell used for the carrier aggregation between the base stations is set from the first base station And a controller that activates a cell set based on the setting signal and transmits a random access signal using the difference information stored in the management table. A user equipment is provided. With this configuration, in a mobile communication system, it is possible to reduce a delay that occurs when inter-base station carrier aggregation is set in a user apparatus.

  Further, in the present embodiment, the mobile station is a base station that can be used as the first base station in a mobile communication system including a first base station and a second base station that communicate with a user apparatus by inter-base station carrier aggregation. When the system frame number is synchronized between the first base station and the second base station, it is determined that acquisition of predetermined broadcast information by the user apparatus is unnecessary, and the first base station When a system frame number is not synchronized between the base station and the second base station, a determination unit that determines that acquisition of predetermined broadcast information by the user apparatus is necessary, and a determination result by the determination unit A transmission signal for transmitting the setting signal to the user apparatus, including whether or not to acquire predetermined broadcast information in a setting signal for setting a cell to be used for inter-base station carrier aggregation. Base station is provided, characterized in that it comprises a part. With this configuration, in a mobile communication system, it is possible to reduce a delay that occurs when inter-base station carrier aggregation is set in a user apparatus.

  Further, in the present embodiment, the mobile station is a base station that can be used as the first base station in a mobile communication system including a first base station and a second base station that communicate with a user apparatus by inter-base station carrier aggregation. Before transmitting a setting signal for setting a cell used for inter-base station carrier aggregation, an acquisition instruction transmitting unit for transmitting an instruction to acquire predetermined broadcast information in the cell to the user apparatus, and the acquisition instruction And a setting signal transmitting unit that transmits the setting signal to the user apparatus after receiving a completion report for the base station. With this configuration, in a mobile communication system, it is possible to reduce a delay that occurs when inter-base station carrier aggregation is set in a user apparatus.

  The acquisition instruction transmission unit may not transmit the acquisition instruction to the user device when it is estimated that the predetermined notification information is acquired in the user device. With this configuration, useless acquisition of predetermined notification information can be avoided.

  Further, in the present embodiment, the mobile station is a base station that can be used as the first base station in a mobile communication system including a first base station and a second base station that communicate with a user apparatus by inter-base station carrier aggregation. A management table storing difference information of system frame numbers between the cell of the first base station and the cell of the second base station, and a cell for setting the cell used for the carrier aggregation between the base stations A base station is provided that includes a setting signal including the difference information stored in the management table, and a transmission unit that transmits the setting signal including the difference information to the user apparatus. With this configuration, in a mobile communication system, it is possible to reduce a delay that occurs when inter-base station carrier aggregation is set in a user apparatus.

  Moreover, in this Embodiment, the carrier aggregation setting method which the said user apparatus used in the mobile communication system provided with the 1st base station and 2nd base station which communicate with a user apparatus by the carrier aggregation between base stations performs An obtaining step of obtaining predetermined broadcast information in the cell before receiving a setting signal for setting a cell used for inter-base station carrier aggregation from the first base station; Receiving the setting signal from one base station, activating a cell set based on the setting signal, and transmitting a random access signal using the predetermined broadcast information acquired by the acquiring step. A carrier aggregation setting method is provided. With this configuration, in a mobile communication system, it is possible to reduce a delay that occurs when inter-base station carrier aggregation is set in a user apparatus.

  The functional configuration of the user apparatus UE described in the present embodiment may be a configuration realized by executing a program by a CPU (processor) in the user apparatus UE including a CPU and a memory. The configuration may be realized by hardware such as a hardware circuit having processing logic described in the above embodiment, or a program and hardware may be mixed.

  The base station eNB described in the present embodiment may also have a configuration realized by a program being executed by a CPU (processor) in a base station eNB including a CPU and a memory. The configuration may be realized by hardware such as a hardware circuit provided with the processing logic described in the above, or a program and hardware may be mixed.

  Although the embodiments of the present invention have been described above, the disclosed invention is not limited to such embodiments, and those skilled in the art will understand various variations, modifications, alternatives, substitutions, and the like. I will. Although specific numerical examples have been described in order to facilitate understanding of the invention, these numerical values are merely examples and any appropriate values may be used unless otherwise specified. The classification of items in the above description is not essential to the present invention, and the items described in two or more items may be used in combination as necessary, or the items described in one item may be used in different items. It may be applied to the matters described in (if not inconsistent). The boundaries between functional units or processing units in the functional block diagram do not necessarily correspond to physical component boundaries. The operations of a plurality of functional units may be physically performed by one component, or the operations of one functional unit may be physically performed by a plurality of components. For convenience of explanation, the user apparatus UE and the base station eNB have been described using functional block diagrams, but such an apparatus may be realized by hardware, software, or a combination thereof. The software operated by the processor of the user apparatus UE and the software operated by the processor of the base station according to the embodiment of the present invention are random access memory (RAM), flash memory, read-only memory (ROM), EPROM, respectively. , EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server, or any other suitable storage medium.

  The present invention is not limited to the above embodiments, and various modifications, modifications, alternatives, substitutions, and the like are included in the present invention without departing from the spirit of the present invention.

eNB, MeNB, SeNB Base station UE User device 101 DL signal transmission unit 102 UL signal reception unit 103 DC control unit 104 Inter-base station communication control unit 105 SFN information acquisition unit 106 Management table storage unit 201 DL signal reception unit 202 UL signal transmission Unit 203 DC control unit 204 MIB information acquisition unit 205 SFN information acquisition unit 206 Management table storage unit 301 DL signal transmission unit 302 UL signal reception unit 303 DC control unit 304 Inter-base station communication control unit 305 SFN information acquisition unit 306 MIB acquisition impossible Time processing unit 404 Notification information acquisition unit 405 MIB acquisition determination unit 403 DC control unit 406 SFN information acquisition unit 401 DL signal reception unit 402 UL signal transmission unit

Claims (10)

The user apparatus used in a mobile communication system including a first base station and a second base station that communicate with a user apparatus by inter-base station carrier aggregation,
A receiving unit that receives a setting signal for setting a cell to be used for inter-base station carrier aggregation from the first base station;
Activates a cell set based on the setting signal received by the receiving unit, and acquires the predetermined broadcast information when there is information indicating that acquisition of the predetermined broadcast information is unnecessary in the setting signal And a control unit that transmits a random access signal without performing the processing. The user apparatus used in a mobile communication system including a first base station and a second base station that communicate with a user apparatus by inter-base station carrier aggregation,
Before receiving a setting signal for setting a cell used for inter-base station carrier aggregation from the first base station, an acquisition unit for acquiring predetermined broadcast information in the cell;
A control unit that receives the setting signal from the first base station, activates a cell set based on the setting signal, and transmits a random access signal using the predetermined broadcast information acquired by the acquiring unit; A user apparatus comprising: The acquisition unit, when receiving an instruction to acquire the predetermined broadcast information from the first base station, acquires the predetermined broadcast information based on the acquisition instruction. The user device described.   The user apparatus according to any one of claims 1 to 3, wherein the predetermined broadcast information is a system frame number in MIB. The user apparatus used in a mobile communication system including a first base station and a second base station that communicate with a user apparatus by inter-base station carrier aggregation,
A management table for storing difference information of system frame numbers between the cell of the first base station and the cell of the second base station;
The difference information stored in the management table is received from the first base station by receiving a setting signal for setting a cell used for carrier aggregation between the base stations, activating the cell set based on the setting signal. And a control unit that transmits a random access signal by using a user device. A base station that can be used as the first base station in a mobile communication system including a first base station and a second base station that communicate with a user apparatus by inter-base station carrier aggregation,
When a system frame number is synchronized between the first base station and the second base station, it is determined that acquisition of predetermined broadcast information by the user apparatus is unnecessary, and the first base station And a determination unit that determines that acquisition of predetermined broadcast information by the user device is necessary when the system frame number is not synchronized between the second base station and the second base station;
Based on the determination result by the determination unit, a transmission unit for transmitting the setting signal to the user apparatus, including whether or not to acquire predetermined broadcast information, in a setting signal for setting a cell used for carrier aggregation between base stations And a base station. A base station that can be used as the first base station in a mobile communication system including a first base station and a second base station that communicate with a user apparatus by inter-base station carrier aggregation,
Before transmitting a setting signal for setting a cell used for inter-base station carrier aggregation, an acquisition instruction transmission unit that transmits an instruction to acquire predetermined broadcast information in the cell to the user apparatus;
A base station comprising: a setting signal transmitting unit that transmits the setting signal to the user apparatus after receiving a completion report for the acquisition instruction. The base according to claim 7, wherein the acquisition instruction transmission unit does not transmit the acquisition instruction to the user apparatus when it is estimated that the predetermined broadcast information is acquired in the user apparatus. Bureau. A base station that can be used as the first base station in a mobile communication system including a first base station and a second base station that communicate with a user apparatus by inter-base station carrier aggregation,
A management table for storing difference information of system frame numbers between the cell of the first base station and the cell of the second base station;
A transmission unit that includes the difference information stored in the management table in a setting signal for setting a cell used for carrier aggregation between the base stations, and transmits a setting signal including the difference information to the user apparatus; A base station comprising: A carrier aggregation setting method executed by the user apparatus used in a mobile communication system including a first base station and a second base station that communicate with the user apparatus by inter-base station carrier aggregation,
Before receiving a setting signal for setting a cell used for inter-base station carrier aggregation from the first base station, an acquisition step of acquiring predetermined broadcast information in the cell;
Receiving the setting signal from the first base station, activating a cell set based on the setting signal, and transmitting a random access signal using the predetermined broadcast information acquired by the acquiring step; A carrier aggregation setting method comprising:

Images