WO2011016195A1

WO2011016195A1 - Wireless communication terminal and method for reporting results of measurements of radio wave conditions

Info

Publication number: WO2011016195A1
Application number: PCT/JP2010/004681
Authority: WO
Inventors: 田村尚志; 平野純; 青山高久
Original assignee: パナソニック株式会社
Priority date: 2009-08-06
Filing date: 2010-07-21
Publication date: 2011-02-10

Abstract

If an event occurs continuously during a trigger interval in a measurement result of a component carrier having a low priority level, then a wireless communication terminal causes a report of the measurement result of the component carrier having the low priority level to be in standby state. If an event occurs continuously during a trigger interval in a measurement result of a component carrier having a high priority level and further if there is the report of the measurement result of the component carrier of the low priority level that is in standby state, then the wireless communication terminal implements both a report of the measurement result of the component carrier having the high priority level and the report of the measurement result of the component carrier of the low priority level that is in standby state. If an event occurs continuously during a trigger interval in a measurement result of a component carrier having a high priority level and further if there is no such report of the measurement result of the component carrier of the low priority level that is in standby state, then the wireless communication terminal implements solely a report of the measurement result of the component carrier having the high priority level. This allows a wireless communication base station to simply perform the mobility control of terminals and improves the data throughputs of the wireless communication terminals.

Description

Wireless communication terminal and radio wave condition measurement result reporting method

Related applications

This application claims the benefit of Patent Application No. 2009-183204 filed in Japan on August 6, 2009 and Patent Application No. 2010-002265 filed in Japan on January 7, 2010. The contents of the application are incorporated herein by reference.

The present invention relates to a wireless communication terminal capable of communicating by simultaneously using respective component carriers of a plurality of communication cells by carrier aggregation, and in particular, a wireless communication terminal that measures a radio wave condition and reports to a wireless communication base station, The present invention also relates to a method for reporting the measurement results of radio wave conditions by the wireless communication terminal.

The standardization organization 3GPP (The 3rd Generation Partnership Project) is promoting standardization of LTE (Long Term Evolution) as the next generation communication standard of W-CDMA (Wideband Code Division Multiple Access).

In LTE, a wireless communication base station (E-UTRAN NodeB (eNB)) of a network (Evolved Universal Mobile Radio Access Network (E-UTRAN)) has a plurality of communication cells, and a wireless communication terminal (User Equipment (User Equipment ( UE)) belongs to one of the communication cells. Hereinafter, the wireless communication base station is simply referred to as “base station”, the communication cell is simply referred to as “cell”, and the wireless communication terminal is simply referred to as “terminal”.

The state of the terminal includes a state called an idle state (RRC_Idle) where a radio bearer (Radio Bearer) is not established with the base station, and a state called a connected state (RRC_Connected) where a radio bearer is established with the base station. is there. When transmitting and receiving data, the terminal needs to change its state to a connected state.

FIG. 24 is a sequence diagram for the terminal 100 to transition from the idle state to the connected state. In order to synchronize with the base station 200, the terminal 100 uses random access means (Random Access Procedure).

As shown in FIG. 24, the terminal 100 sends a random access preamble (Random Access Preamble) to the base station 200 (S2101). The base station 200 sends a random access response message (Random Access Response) to the terminal 100 as a response to the random access preamble (S2102). This random access response message includes a temporary cell-specific terminal identifier (temporary C-RNTI). When terminal 100 has this temporary cell-specific terminal identifier, terminal 100 and base station 200 can use signaling radio bearer No. 0 (Signaling Radio Bearer 0, hereinafter also referred to as “SRB0”). The SRB 0 is used to transmit and receive a radio resource control message (Radio Resource Control message, hereinafter also referred to as “RRC message”) using a common control channel (Common Control Channel, hereinafter also referred to as “CCCH”).

The terminal 100 sends an RRC connection request (RRC Connection Request) to the base station 200 in order to establish an RRC connection using the SRB0 (S2103). The base station 200 transmits an RRC connection setup to the terminal 100 using SRB0 in order to establish a signaling radio bearer No. 1 (Signaling Radio Bearer 1, hereinafter simply referred to as “SRB1”) (S2104). ). In SRB1, terminal 100 transmits and receives an RRC message and a non-access layer message (also referred to as “NAS message”) using a dedicated control channel (also referred to as “DCCH”). Is for.

After that, the base station 200 establishes the SRB1 until it receives RRC connection setup complete from the terminal 100 (S2105). The timing at which the base station 200 establishes the SRB1 depends on the setting of the base station 200. On the other hand, when receiving the RRC connection setup, the terminal 100 establishes SRB1 (S2106).

Next, in order to confirm that the establishment of the RRC connection has been completed successfully, the terminal 100 transmits an RRC connection setup complete to the base station 200 using the SRB 1 (S2107). The base station 200 sends a security mode command (Security Mode Command) to the terminal 100 using the SRB 1 in order to validate AS security (Access Stratum Security (AS Security)) (S2108). After that, when the base station 200 receives a security mode completion (Security Mode Complete) sent from the terminal 100 (S2112), AS security is enabled between the terminal 100 and the base station 200.

At this time, the base station 200, for example, adds a higher urgency RRC message, such as a handover command or a measurement result report, than a NAS message with a lower urgency level, such as service addition. In order to give priority to the transmission of the SRC, a signaling radio bearer No. 2 (Signaling Radio Bearer 2, hereinafter simply referred to as “SRB2”) is established (S2110) for lowering priority than the SRB1 and transmitting / receiving NAS messages. In the base station 200, the SRB2 is established at the set predetermined timing. Further, the base station 200 transmits RRC connection reconfiguration to the terminal 100 (S2109). When the terminal 100 receives RRC connection reconfiguration, the terminal 100 establishes SRB2 (S2111). In order to confirm that the RRC connection reconfiguration has been completed successfully, the terminal 100 transmits RRC connection reconfiguration completion (RRC Connection Reconfiguration Complete) to the base station 200 using the SRB 1 (S2113).

This RRC connection reconfiguration includes setting information of a data radio bearer (Data Radio Bearer, hereinafter simply referred to as “DRB”) for transmitting and receiving data between the terminal 100 and the base station 200. Establishes DRB from RRC connection reconfiguration. As described above, the terminal 100 can shift from the idle state to the connected state.

When a connected terminal moves out of the cell, a handover (Handover, hereinafter referred to as “HO”) is performed to switch communication with the cell currently used by the terminal to communication with another adjacent cell in order to prevent communication disconnection. Technology).

FIG. 25 is a sequence diagram illustrating an example of handover. The terminal 100 receives a radio wave condition (reception power or reception quality) based on a reference signal measurement (Measurement Configuration, hereinafter simply referred to as “measurement setting”) included in the RRC connection reconfiguration. And a measurement result report (Measurement Report) is created (S2201). When an event for sending the created measurement result report (for example, the received power exceeds a set threshold (Threshold), etc.) occurs, the terminal 100 is connected to a base station (hereinafter referred to as Source eNB or “Movement”). A measurement result report is sent to 201 (also referred to as “original base station”) (S2202). The source base station 201 determines a base station (hereinafter also referred to as Target eNB or “destination base station”) 202 that is a handover destination of the terminal 100 based on the measurement result report (S2203). Then, the source base station 201 sends a handover request (Handover Request) to the destination base station 202 in order to transmit the handover request and information necessary for the handover to the determined destination base station 202 (S2204). .

Upon receiving the handover request, the movement-destination base station 202 performs admission control (S2205), measurement configuration (Measurement Configuration), mobility control information (Mobility Control Information), radio resource configuration (Radio Resource Configuration), A handover command including a security configuration (Security Configuration) is created, and the handover command is transmitted to the source base station 201 as a handover request response (Handover Request Ack) (S2206). When the source base station 201 receives the handover command from the destination base station 202, the source base station 201 sends the handover command as it is to the terminal 100 (S2208). At this time, the source base station 202 sends a downlink allocation (DL allocation) to the terminal 100 (S2207). Also, the source base station 201 sends the SN of the data packet sent to the terminal 100 first among the sequence numbers (Sequence Number, hereinafter also referred to as “SN”) of the data packet that has not yet been sent to the terminal 100. (SN Status Transfer) is transferred to the destination base station 202 (S2209), and the data to be sent to the terminal 100 is also transferred to the destination base station 202.

The terminal 100 uses the random access means to synchronize with the destination base station 202 (S2210), sends a handover confirmation to the destination base station 202 (S2212), and completes the handover. As described above, a connected terminal can switch communication from a communicating base station to another base station without communication interruption.

The measurement settings for causing the terminal to measure received power and reception quality include measurement identifiers (Measurement Identities (MeasID)) that indicate the measurement settings, measurement objects that indicate the measurement target (Measurement Object (MeasObject)), Quantity setting (Quantity Configuration (QuantityConfig)) indicating the filtering processing operation of the measurement results, trigger setting for sending the measurement result report, and report setting (Reporting Configuration (ReportConfig)) indicating the format of the measurement result report, Information such as a measurement gap indicating a period in which data for measuring other frequencies and other systems is not transmitted / received is included. And this measurement setting is sent by being included in RRC connection reconfiguration (RRC Connection Reconfiguration). Among them, the measurement identifier (MeasID), the measurement target (MeasObject), and the report setting (ReportConfig) are linked.

FIG. 26 is a diagram illustrating an example of measurement settings in the terminal. In FIG. 26, a measurement identifier (MeasID) is an identifier indicating a measurement setting. The measurement setting is configured by a combination of a measurement object identifier (MeasObjectID) and a report setting identifier (ReportConfigID). The measurement target identifier is an identifier for identifying the measurement target (MeasObject), and the report setting identifier is an identifier for identifying the report setting (ReportConfig).

FIG. 27 is a diagram illustrating an example of a measurement target (MeasObject). The measurement targets are downlink carrier frequency (EUTRA-DL-CarrierFreq), measurement bandwidth (MeasurementBandwidth), frequency offset (OffsetFreq), deletion list from neighboring cell list (CellsToRemoveList), list of additional changes to neighboring cells ( CellsToAddModifyList), a removal list from the black list cell list (BlackListedCellsToRemoveList), and an addition modification list to the black list cell (BlackListedCellsToAddModifyList).

The report setting (ReportConfig) depends on the trigger type of the measurement result report, the trigger quantity (Trigger Quantity), the report quantity (Report Quantity), the maximum number of cells to report, the report cycle, the report amount (report Amount), etc. Composed. There are trigger types that are sent when an event occurs (event trigger reporting), those that are sent periodically (periodic reporting), and those that are sent periodically after an event occurs (event trigger periodic reporting). E-UTRAN event types include, for example, serving cell higher than threshold, serving cell lower than threshold, neighboring cell better than serving cell, neighboring cell better than threshold, serving cell worse than threshold 1 There are five types of cells that are better than threshold 2. In addition, in order to determine the occurrence of an event, hysteresis (Hysteresis) and a period (Time To Trigger, hereinafter also referred to as “TTT”) until triggering transmission of a measurement result report are set. Hysteresis is used when the terminal state enters an event triggered reporting condition when an event occurs (event) and when it leaves the state that triggers a measurement result report due to an event. Parameter. Hysteresis is a margin above and below the threshold value for determining an event. The value measured by the terminal usually has some fluctuations. For this reason, when the threshold is uniquely determined, there may be a situation where the case where the measurement result report is triggered is switched to the case where the measurement result report is entered and the case where the threshold is exited many times. By providing hysteresis, it is effectively prevented that the measurement result report enters and exits the state triggered by the occurrence of an event many times. Here, “the state in which the measurement result report is triggered by the occurrence of an event” means a state in which a predetermined event criterion for triggering the report of the measurement result is satisfied. That's it.

In order for the terminal to trigger the measurement result, it is necessary to maintain the event occurrence state continuously for a predetermined period. This period is TTT. That is, when an event occurs continuously in the terminal during the TTT period, transmission of the measurement result report is triggered, and the measurement result report is transmitted from the terminal to the base station.

FIG. 28 is a diagram showing an example of a measurement result report. The structure of the measurement result report varies depending on what is measured. For example, the constituent elements of the measurement result report differ depending on the cell of E-UTRA or depending on different radio access technologies (Radio Access Technology, hereinafter simply referred to as “RAT”). Here, the case of E-UTRA will be described as a representative example.

When measuring an E-UTRA cell, the measurement result report is composed of the components shown in FIG. At the top of the measurement result report, the measurement identifier (MeasID), the serving cell reference signal received power (Reference Signal Received Power, hereinafter simply referred to as “RSRP”), the serving cell reference signal received quality (Reference Signal Received Quality, hereinafter simply “ "RSRQ"). When the measurement result of the neighbor cell is included, the measurement result report is the next part of the information of the neighbor cell (Neighbour cell) that meets the event criteria up to the maximum number of cells (maxReportCells) that can be reported included in the measurement settings. Included. The adjacent cell information includes a physical cell identifier (Physical Cell Identity, hereinafter also referred to as “PCI”). Neighboring cell information further includes a cell global identifier (Cell Global Identity, hereinafter referred to as “CGI”), a tracking area code (Tracking Area Code), and a PLMN identifier list (Public Land Mobile Network Identity List) as an option. Can do. Further, the information on the neighboring cell may optionally include information on RSRP or RSRQ. Which information of RSRP or RSRQ is included is described in the measurement settings. When there are a plurality of neighboring cells, information on a plurality of neighboring cells is included. For example, as shown in FIG. 28, the information of the next adjacent cell is included after the information of the first adjacent cell.

Also, the component values of the measurement result report differ depending on the purpose of measurement. There are three purposes: best cell search, SON (Self Optimizing Network), and CGI reports. When the purpose is to search for the best cell, the configuration of the measurement result report is as described above. When the purpose is SON, it becomes a restriction condition that it becomes a measurement result report of RAT and that there is one cell to report. When the purpose is a CGI report, a measurement result report including CGI of an adjacent cell as an option is used. However, when the CGI of an adjacent cell cannot be measured, the restriction is exempted.

The terminal performs the measurement indicated by the measurement identifier and sends a measurement result report to the base station. Based on the measurement result report, the base station determines whether or not to perform handover (to which cell, if handover is performed, which cell is to be handed over), and starts the procedure when performing handover.

Standardization organization 3GPP is proceeding with standardization of LTE-A (Long Term Evolution Advanced) as a next-generation wireless communication standard compatible with LTE. In LTE-A, introduction of carrier aggregation in which a terminal simultaneously uses component carriers of a plurality of cells of one base station is under consideration. Note that carrier aggregation is also referred to as band aggregation.

FIG. 29 is a diagram illustrating an example of carrier aggregation. In FIG. 29, terminal 100 includes four component carriers whose carrier frequencies are f1, f2, f3, and f6 among the six component carriers whose carrier frequencies are f1, f2, f3, f4, f5, and f6, respectively. An example of simultaneous use is shown. As described above, the use of a plurality of component carriers is expected to improve the throughput of communication between the terminal 100 and the base station 200.

When the terminal 100 uses a plurality of component carriers, from the viewpoint of connection between the terminal 100 and the base station 200, the component carrier includes an important component carrier and a less important component carrier.

Here, as in the background art described above, considering that the base station performs mobility control of the terminal based on the measurement result report sent from the terminal, the terminal performs measurements on important component carriers. It is conceivable that the base station performs mobility control of the terminal by sending a measurement result report of the component carrier to the base station.

However, focusing on the data throughput at the terminal, in addition to the information on the important component carrier, the information on the less important component carrier can find a better cell for the terminal. Throughput can be improved.

Therefore, in order to improve the data throughput of the terminal, it is conceivable to send a measurement result report of all the component carriers used by the terminal to the base station. In this case, the measurement result report is sent every time an event occurs. Therefore, if simultaneous measurement is performed with multiple carrier frequencies used in carrier aggregation, multiple events occur at close timings, and multiple measurement result reports are likely to be sent to the base station at close timings. There is a problem that the overhead of the network becomes large. In addition, multiple measurement result reports are sent at close timing to each other, so that after the base station has already determined the handover of the terminal, a measurement result report of a different component carrier arrives from the terminal, and the base station again determines the handover destination. There is a problem that the mobility control of the terminal in the base station becomes complicated, such as correction.

As described in Non-Patent Documents 4 to 7, if events occur at almost the same timing, a method of combining multiple measurement results into one measurement result report, or another event occurs during TTT For example, there is a method in which a single measurement result report is collected at the timing when the TTT of the event that started the TTT ends later.

However, in carrier aggregation using a plurality of component carriers, it is necessary to consider the priority between component carriers, and thus the above method cannot be applied as it is. Specifically, in the method of adjusting to the end of the TTT, the measurement result report must be sent early in the important component carrier, but after the TTT starts in the important component carrier, the less important component carrier When the TTT is started in, it is necessary to wait for the TTT to end in the less important component carrier, so that the timing of transmitting the measurement result report including the measurement result of the important component carrier is delayed. There is.

The present invention has been made to solve the conventional problems, and it is an object of the present invention to provide a terminal that can easily perform mobility control of a terminal at a base station. Another object of the present invention is to provide a terminal capable of improving data throughput.

The wireless communication terminal of the present invention is a wireless communication terminal capable of communicating with a wireless communication base station by simultaneously using each component carrier of a plurality of communication cells by carrier aggregation, and the measurement result of the radio wave condition of the component carrier is A measurement result report determination unit that determines whether or not a predetermined event criterion for triggering a measurement result report is satisfied, and a component carrier related to determination of the measurement result is a high-priority component carrier or low A carrier priority determination unit that determines whether the carrier is a priority component carrier, and a measurement result of the component carrier that has been determined to be low priority by the carrier priority determination unit is a reference of an event continuously for a predetermined trigger period. If the above is satisfied, the low priority component carrier When the measurement result of the component carrier that has been determined to be high priority by the carrier priority determination unit satisfies the event criteria continuously for a predetermined trigger period, When there is a report of the measurement result of the low-priority component carrier, the measurement result of the low-priority component carrier in the waiting state is reported to the radio communication base station together with the measurement result of the high-priority component carrier. And a measurement result report control unit for reporting the above.

As described below, there are other aspects of the present invention. Accordingly, the disclosure of the present invention is intended to provide part of the invention and is not intended to limit the scope of the invention described and claimed herein.

In the present invention, the base station can easily perform mobility control of the terminal by reporting the necessary measurement result to the base station early in consideration of the priority of the component carrier used by the terminal, It is possible to provide a terminal having an effect that the data throughput of the terminal can be improved.

FIG. 1 is a flowchart for explaining the operation of a terminal according to the first embodiment of the present invention. FIG. 2 is an overall configuration diagram of the wireless communication system according to the embodiment of this invention. FIG. 3 (a) is a schematic diagram showing a case where carrier aggregation is performed by simultaneously using a plurality of component carriers belonging to the same area in the embodiment of the present invention. FIG. 3 (b) shows the embodiment of the present invention. Schematic diagram showing a case where a plurality of component carriers belonging to different areas of the same base station are simultaneously used for carrier aggregation in FIG. 3C. FIG. 3C is different for different frequencies of base stations in the embodiment of the present invention. FIG. 3 (d) is a schematic diagram showing a case where carrier aggregation is performed using a plurality of component carriers at the same time in a situation where a cell of a size is managed. FIG. Schematic diagram illustrating a case where the carrier aggregation using component carrier of the plurality of same carrier frequencies belonging to that area at the same time FIG. 4A shows an example of a method for determining the priority of a component carrier when the terminal according to the embodiment of the present invention uses one backward compatible component carrier and one non-backward compatible component carrier. Fig. 4 (b) is a diagram for explaining the components. Fig. 4 (b) shows the priority of the component carrier when the terminal according to the embodiment of the present invention uses two backward compatible component carriers and one non-backward compatible component carrier. The figure for explaining the example of the determination method of the degree FIG. 5 is a block diagram of the terminal according to the first embodiment of this invention. FIG. 6 is a block diagram of the base station according to the first embodiment of this invention. FIG. 7 (a) is a diagram for explaining the measurement result reporting method when TTT is first started with a low priority component carrier in the terminal according to the first embodiment of the present invention. FIG. 7 (b) ) Is a diagram for explaining a method of reporting a measurement result when TTT is first started on a high-priority component carrier in the terminal according to the first embodiment of this invention. FIG. 8 is a diagram showing a configuration of a measurement result report according to the first embodiment of this invention. FIG. 9 is a block diagram of a terminal according to the second embodiment of this invention. FIG. 10 is a block diagram of a base station according to the second embodiment of this invention. FIG. 11 (a) shows a measurement result report when TTT is first started on a low priority component carrier when the quality of the component carriers is different in the terminal according to the second embodiment of the present invention. Diagram for explaining the method: The target is the TTT that starts with the high-priority component carrier when the quality of the component carriers differs in the terminal according to the second embodiment of the present invention in FIG. 11 (b). For explaining the measurement result reporting method FIG. 12 is a flowchart for explaining the operation of the terminal according to the second embodiment of the present invention. FIG. 13 is a block diagram of a terminal according to the third embodiment of this invention. FIG. 14 (a) is a diagram for explaining a measurement result reporting method when TTT is first started on a low-priority component carrier in the terminal according to the third embodiment of the present invention. FIG. 14 (b) ) Is a diagram for explaining the measurement result reporting method when TTT is first started with a high priority component carrier in the terminal of the third embodiment of the present invention. FIG. 14 (c) In the terminal according to the third embodiment of the invention, a method of reporting a measurement result when TTT starts with a high-priority component carrier first and after the elapse of hTTT, TTT starts with a low-priority component carrier will be described. Illustration to do FIG. 15 is a block diagram of a terminal according to the fourth embodiment of this invention. FIG. 16 is a block diagram of a base station according to the fourth embodiment of this invention. FIG. 17 (a) illustrates a measurement result reporting method when TTT is started on the high priority and low priority component carriers for the same base station in the terminal according to the fourth embodiment of the present invention. Fig. 17 (b) is a method for reporting measurement results when TTT is started on a high-priority component carrier and a low-priority component carrier for different base stations in the terminal according to the fourth embodiment of the present invention. Illustration for explaining FIG. 18 is a block diagram of a terminal according to the fifth embodiment of this invention. FIG. 19 is a diagram for explaining a measurement result reporting method in the terminal according to the fifth embodiment of this invention. FIG. 20 is a block diagram of a terminal according to the sixth embodiment of this invention. FIG. 21 is a diagram for explaining a measurement result reporting method in the terminal according to the sixth embodiment of this invention. FIG. 22 is a flowchart for explaining the operation of the terminal in the sixth embodiment of the invention. FIG. 23 is a diagram showing a configuration of a measurement result report according to a modification of the present invention. FIG. 24 is a sequence diagram for a conventional terminal to transition from an idle state to a connected state. FIG. 25 is a sequence diagram showing an example of a conventional handover. FIG. 26 shows an example of measurement settings in a conventional terminal. FIG. 27 is a diagram showing an example of a conventional measurement object FIG. 28 shows an example of a conventional measurement result report. FIG. 29 is a diagram showing an example of conventional carrier aggregation

The detailed description of the present invention will be described below. The embodiments described below are merely examples of the present invention, and the present invention can be modified in various ways. Accordingly, the specific configurations and functions disclosed below do not limit the scope of the claims.

A radio communication terminal according to an embodiment of the present invention is a radio communication terminal capable of communicating with a radio communication base station by using each component carrier of a plurality of communication cells simultaneously by carrier aggregation, and the radio wave status of the component carrier A measurement result report determination unit that determines whether or not the measurement result of the above satisfies a predetermined event criterion for triggering the report of the measurement result, and the component carrier related to the determination of the measurement result is a high priority component carrier The carrier priority determination unit for determining whether the carrier carrier is a low-priority component carrier, and the measurement result of the component carrier determined to be low-priority by the carrier priority determination unit continues for a predetermined trigger period. If the event criteria are met, the low priority component In the case where the measurement result of the component carrier determined to be a high priority by the carrier priority determination unit satisfies the event criteria continuously for a predetermined trigger period. When there is a report of the measurement result of the low-priority component carrier in the waiting state, the measurement result of the high-priority component carrier is reported to the radio communication base station together with the low-priority component carrier in the waiting state. And a measurement result report control unit for reporting the measurement results.

With this configuration, the measurement result of the low priority component carrier waits for the measurement result of the high priority component carrier and reports both to the base station at the same time. Can be considered in consideration of the quality of low-priority component carriers, the base station can easily control the mobility of the terminal, and improve the data throughput of the terminal Can do. Further, by suspending reporting of measurement results of low priority component carriers, it is possible to reduce useless use of radio resources and to suppress power consumption of the terminal.

In the wireless communication terminal according to the embodiment of the present invention, the measurement result report control unit continues the measurement result of the component carrier determined to be high priority by the carrier priority determination unit for a predetermined trigger period. When the event criteria are met and there is no report of the measurement result of the low-priority component carrier in the waiting state, the measurement result of the high-priority component carrier is separately reported to the radio communication base station. To do.

With this configuration, measurement results of high-priority component carriers that are important component carriers are reported without waiting for measurement results of low-priority component carriers that are less important. Measurement results can be reported to the base station.

In the wireless communication terminal according to the embodiment of the present invention, the measurement result report control unit reports the measurement result of the low priority component carrier in the waiting state together with the measurement result report of the high priority component carrier. Creates one measurement result report including the measurement result of the high priority component carrier and the measurement result of the low priority component carrier in the waiting state.

With this configuration, it is possible to know the measurement results of the high-priority component carrier and the low-priority component carrier by referring to one measurement result report in the base station, and the measurement result of the high-priority component carrier The handover can be determined in consideration of the measurement result of the low-priority component carrier based on the reference.

Moreover, in the wireless communication terminal according to the embodiment of the present invention, the measurement result report control unit is determined to be low priority by the carrier priority determination unit only when the quality among the plurality of component carriers is the same. When the component carrier measurement results satisfy the event criteria for a predetermined trigger period, the measurement results of the low-priority component carriers are put on standby, and the quality among multiple component carriers is different. If the measurement result of the component carrier determined to be low priority by the carrier priority determination unit satisfies the event criteria for a predetermined trigger period, the measurement of the high priority component carrier is performed. If the results do not meet the event criteria, the high-priority component carrier measurement Results without waiting for the meet the criteria of events continues for a predetermined period of time, reports the measurement result of the low priority component carrier.

With this configuration, if the quality between component carriers is different, the probability that the measurement result of the high-priority component carrier is reported in the situation where the measurement result of the low-priority component carrier is reported is between component carriers. Therefore, by reporting the measurement results only with low priority component carriers, it is possible to quickly handover a component carrier with a poor radio wave condition to another component carrier. Data throughput can be improved.

The wireless communication terminal according to the embodiment of the present invention further includes an inter-carrier quality determination unit that determines whether the quality between a plurality of component carriers is the same or different.

With this configuration, even when it is not known that the quality between component carriers is different in advance, it is possible to determine whether the quality among a plurality of component carriers is the same or different in the terminal.

In the wireless communication terminal according to the embodiment of the present invention, the component carrier measurement result determined to be low priority by the carrier priority determination unit satisfies the event criterion, and the carrier priority determination unit performs high priority. A trigger period shortening unit that shortens the trigger period of the high-priority component carrier when the measurement result of the component carrier determined to be the degree satisfies the event criterion;

With this configuration, since the report of the measurement result of the high-priority component carrier can be sent to the base station earlier than before, the base station can make a handover decision earlier than before.

In the wireless communication terminal according to the embodiment of the present invention, the trigger period shortening unit generates an event in the component carrier that has been determined to be low priority by the carrier priority determination unit. When the event has occurred in the component carrier that has been determined to be high priority by the carrier priority determination unit, the trigger period of the high priority component carrier is shortened.

With this configuration, it is possible to send a report of the measurement result of the high priority component carrier to the base station together with the low priority component carrier at an earlier timing than before.

In the wireless communication terminal according to the embodiment of the present invention, the trigger period shortening unit generates an event in the component carrier that has been determined to be high priority by the carrier priority determination unit, but the event is the trigger period. When the event has occurred in the component carrier that has been determined to be low priority by the carrier priority determination unit, the trigger period of the high priority component carrier is shortened.

This configuration makes it possible to send a report of measurement results of high-priority component carriers independently to the base station at a timing earlier than before.

In the wireless communication terminal according to the embodiment of the present invention, the trigger period shortening unit has already passed the trigger period after the shortening of the high priority component carrier when the event occurs in the low priority component carrier. If so, report the measurement results of the high priority component carrier immediately. *

Further, in the wireless communication terminal according to the embodiment of the present invention, the trigger period shortening unit is a wireless communication base station in which the low-priority component carrier in which the event has occurred and the high-priority component carrier in which the event has occurred are the same. Only when it is a component carrier, the trigger period of the high-priority component carrier is shortened, and the low-priority component carrier where the event occurred is different from the high-priority component carrier where the event occurred In the case of the component carrier, the trigger period of the high priority component carrier is not shortened.

With this configuration, in order to shorten the trigger period of the high-priority component carrier when the radio conditions of the same base station improve in the high-priority component carrier and the low-priority component carrier, the data throughput of the terminal Can be handed over to the base station.

In the wireless communication terminal according to the embodiment of the present invention, the component carrier measurement result determined to be low priority by the carrier priority determination unit satisfies the event criterion, and the carrier priority determination unit performs high priority. When the measurement result of the component carrier determined to be the degree satisfies the event criterion, the apparatus further includes a trigger period extension unit that extends the trigger period of the low priority component carrier.

With this configuration, by extending the trigger period in the low-priority component carrier, the number of reports containing the measurement results of the low-priority component carrier is reduced, and the radio status of the low-priority component carrier changes. Since a measurement result is reported only when there is more certainty that there has been, it is possible to suppress unnecessary transmission of the measurement result report, and it is possible to reduce power consumption of the terminal and to effectively use radio resources.

Further, in the wireless communication terminal according to the embodiment of the present invention, the measurement result report control unit has a predetermined trigger period when the measurement result of the first component carrier determined to be high priority by the carrier priority determination unit. When the event criterion is continuously satisfied, a predetermined trigger is still present after a state in which the measurement result of the second component carrier determined to be high priority by the carrier priority determination unit satisfies the event criterion occurs. When the period of time does not continue, the second component carrier is reported together with the measurement result of the first component carrier without waiting for the measurement result of the second component carrier to satisfy the event criteria for a predetermined trigger period. Report carrier measurement results.

With this configuration, measurement results of a plurality of high-priority component carriers can be collectively reported at a time, so that the MR including the measurement results of the high-priority component carriers is not repeatedly sent, The station can easily make a handover decision.

In the wireless communication terminal according to the embodiment of the present invention, the measurement result report control unit reports the measurement result of the second component carrier, and the measurement result of the second component carrier uses the event reference as a predetermined trigger period. Report that it was not continuously satisfied.

With this configuration, when the base station receives a report of measurement results of two high-priority component carriers, it can determine which of the high-priority component carriers has not expired the TTT.

In addition, the wireless communication terminal according to the embodiment of the present invention determines the priority of the component carrier by any of the following methods.
(1) An anchor carrier that manages a connection with a radio communication base station is a high priority component carrier, and a component carrier other than the anchor carrier is a low priority component carrier.
(2) A backward compatible component carrier is a high priority component carrier, and a component carrier other than the backward compatible component carrier is a low priority component carrier.
(3) A component carrier transmitting PDCCH is a high priority component carrier, and a component carrier not transmitting PDCCH is a low priority component carrier.
(4) A high priority component carrier and a low priority component carrier are set based on the frequency priority broadcast from the radio communication base station.
(5) An anchor carrier that manages a connection with a radio communication base station is a high-priority component carrier, a carrier that transmits a PDCCH other than the anchor carrier is a low-priority component carrier, and a PDCCH is transmitted. Do not make measurements on non-component carriers.

In addition, the radio wave condition measurement result reporting method according to the embodiment of the present invention includes a radio wave condition in a radio communication terminal capable of communicating with a radio communication base station by simultaneously using each component carrier of a plurality of communication cells by carrier aggregation. A measurement result reporting method for each of a plurality of component carriers, a measurement step for obtaining a measurement result from a reference signal indicating their radio wave conditions, and each of the measurement results for triggering reporting of the measurement result A measurement result report determination step for determining whether or not a predetermined event criterion is satisfied, and whether a component carrier related to determination of the measurement result is a high-priority component carrier or a low-priority component carrier Carrier priority determination step and carrier priority determination step When the component carrier measurement result determined to be low-priority by the above determination satisfies the event criteria for a predetermined trigger period, it waits to report the measurement result of the low-priority component carrier When the measurement result of the component carrier determined to be the high priority by the determination of the report waiting step and the carrier priority determination step satisfies the event criteria continuously for a predetermined trigger period, In the waiting state determination step for determining whether or not there is a report on the measurement result of the low priority component carrier, and in the waiting state determination step, it is determined that there is a report on the measurement result of the low priority component carrier in the waiting state. The measurement results of the high-priority component carrier to the wireless communication base station. In the measurement result merge report step for reporting the measurement result of the low-priority component carrier in the waiting state and the waiting state determination step, the measurement result of the low-priority component carrier in the waiting state is not reported. When determined, the wireless communication base station has a configuration including a measurement result single reporting step for independently reporting a measurement result of a high priority component carrier.

The radio communication base station according to the embodiment of the present invention is a radio communication base station capable of providing communication by carrier aggregation using each component carrier of a plurality of communication cells simultaneously to a radio communication terminal. Receiving a report of measurement results of radio wave quality of component carriers from a wireless communication terminal, and receiving a report of measurement results of low priority component carriers together with measurement results of high priority component carriers at the reception unit A handover determination processing unit that prioritizes the measurement result of the high-priority component carrier and also determines the handover in consideration of the measurement result of the low-priority component carrier. Yes.

The radio communication system according to the embodiment of the present invention is a radio communication system including the radio communication base station and the radio communication terminal. In this radio communication system, the radio communication base station and the radio communication terminal can communicate with each other using component carriers of a plurality of communication cells simultaneously by carrier aggregation.

Hereinafter, a wireless communication system according to an embodiment of the present invention will be described in detail with reference to the drawings. Hereinafter, a radio communication system including a terminal and a base station will be described as an example. Hereinafter, the first to sixth embodiments will be described. First, parts common to the first to sixth embodiments will be described, and then the features of the first to sixth embodiments will be described. The relevant part will be described. In the first to sixth embodiments, components having the same function are denoted by the same reference numerals, and redundant description is omitted.

[Overall configuration of wireless communication system]
The radio communication system according to the present embodiment includes a plurality of terminals and a plurality of base stations. In a wireless communication system, one base station constitutes a plurality of cells (also referred to as “areas”). Here, a cell refers to an identifier sent from one base station to a geographical area or a radio network object that can be uniquely identified based on a difference in frequency used. In the following description, a component carrier basically refers to a radio resource in a physical layer that is identified by a terminal by frequency and geographical area, like a cell.

In the following embodiments, the terminal is a mobile phone, and the base station is a mobile phone base station. In the following embodiment, a case where the present invention is applied to LTE and LTE-A, which are mobile communication technologies standardized by 3GPP, will be described. However, the terminal of the present invention is not limited to the mobile phone, and the base station is not limited to the base station of the mobile phone. In addition, the present invention is not limited to the above-mentioned standard defined by 3GPP, and is not limited to wireless LAN (Wireless Local Area Network), IEEE802.16, IEEE802.16e or IEEE802.16m, etc., WiMAX (Worldwide Interoperability for Microwave Access), It can be applied to wireless access technologies such as 3GPP2, SAE (System Architecture Evolution), or fourth generation mobile communication technology.

FIG. 2 is an overall configuration diagram of the wireless communication system 900 according to the embodiment of this invention. In the wireless communication system 900, a terminal can communicate with one base station by carrier aggregation by simultaneously using component carriers of a plurality of cells. In the example of FIG. 2, the terminal 101 performs carrier aggregation by simultaneously using two cell component carriers, ie, a cell 1 component carrier (carrier frequency is f1) and a cell 4 component carrier (carrier frequency is f2). Also, the terminal 103 performs carrier aggregation using the component carrier of cell 3 (carrier frequency is f1) and the component carrier of cell 6 (carrier frequency is f2) simultaneously. The wireless communication system 900 may include a conventional terminal that does not have a carrier aggregation function, such as the terminal 102. The terminal 102 communicates with the base station 200 using the component carrier of cell 2 (carrier frequency is f1).

FIG. 3 is a schematic diagram showing a plurality of cells managed by the base station. In carrier aggregation, each component carrier of a plurality of cells is used at the same time, and there are various modes of combinations of the plurality of cells. FIG. 3 shows three cells (cell 1, cell 2, cell 3) corresponding to the carrier frequency f1 and three cells (cell 4, cell 5, cell 6) corresponding to the carrier frequency f2 in one base station. Indicates the status being managed.

As a mode of simultaneously using a plurality of component carriers of different carrier frequencies belonging to the same base station, a case of simultaneously using a plurality of component carriers of different carrier frequencies belonging to the same area of the same base station as shown in FIG. In other cases, as shown in FIG. 3B, component carriers having different carrier frequencies belonging to different areas of the same base station may be used simultaneously. Also, as shown in FIG. 3 (c), carrier aggregation is performed in the same manner when cells of different sizes are managed at different carrier frequencies of the same base station. Further, as shown in FIG. 3D, a plurality of component carriers having the same carrier frequency belonging to different areas of the same base station may be used at the same time. In this specification, the term “carrier aggregation” includes the case of using a plurality of component carriers having the same carrier frequency as shown in FIG.

The carrier aggregation described above is merely an example, and the number of cells that can be used in the present invention is not limited to these examples. Also, in the present invention, in some cases (depending on the situation), only one cell may be used.

In the following embodiments, a radio communication system in which a base station and a terminal can communicate using component carriers of a plurality of carrier frequencies (for example, six frequencies f1, f2, f3, f4, f5, and f6) is taken as an example. explain. In this case, a single base station forms a plurality of cells for each of a plurality of carrier frequencies.

In addition, as described above, the type of trigger for reporting the measurement result for handover includes the occurrence of an event that “the neighboring cell is better than the serving cell”, but this event is used as a trigger in carrier aggregation. In this case, it is necessary to determine which cell is to serve as a serving cell among a plurality of cells respectively corresponding to a plurality of component carriers used simultaneously. The following two methods can be considered for determining the serving cell. The first is a method in which a specific component carrier is used as a serving cell. A specific component carrier is instruct | indicated from a base station, or is selected from the component carriers which the terminal is using. The second is a method in which a cell used at each component carrier frequency is a serving cell. In addition, the method of determining a serving cell by methods other than this may be used.

In the wireless communication system of the following embodiment, a plurality of component carriers used for carrier aggregation are an important component carrier, that is, a high priority component carrier, and a low importance component carrier, that is, a low priority component carrier. The handover is determined separately. The following methods can be employed for dividing the high priority component carrier and the low priority component carrier.

[Determination method of component carrier priority]
A first example of a component carrier priority determination method is a method applicable when a terminal manages a connection with a base station using one component carrier. The component carrier that manages this connection is called an anchor carrier. In this case, an anchor carrier can be a high priority component carrier, and a component carrier other than the anchor carrier can be a low priority component carrier. The terminal uses the anchor carrier to receive broadcast information and manage security keys. Which component carrier is used as the anchor carrier is notified from the base station to the terminal, or one of the carriers used by the terminal for carrier aggregation may be selected as the anchor carrier. In addition, when carrier aggregation is performed using component carriers of different frequency bands (for example, 800 MHz band and 2 GHz band), each frequency band may have one anchor carrier, or one for all frequency bands. You may have an anchor carrier. By doing so, the radio wave condition in the component carrier necessary for the terminal to establish a connection with the base station is preferentially handled, and the connection can be changed only when the terminal needs to change the connection. it can.

In the second example of the method for determining the priority of the component carrier, the backward compatible component carrier is a high priority component carrier, and the other component carriers are low priority component carriers. The backward compatible component carrier is a component carrier in which broadcast information necessary for a Rel-8 LTE terminal to connect is broadcast. The non-backward compatible component carrier is a component carrier in which a part of broadcast information necessary for the connection of the Rel-8 LTE terminal is insufficient. An extension component carrier is a component carrier used by an LTE-A terminal, and an LTE-A terminal cannot be used by itself, but can be used together with a backward compatible component carrier or a non-backward compatible component carrier. To be a career. When the terminal uses a non-backward compatible component carrier and an extension component carrier, the non-backward compatible component is a high priority component carrier and the extension component carrier is a low priority component carrier.

FIG. 4 is a diagram for explaining a second example of the component carrier priority determination method. For example, when the terminal performs carrier aggregation using a backward compatible component carrier with a carrier frequency f1 and a non-backward compatible component carrier with a carrier frequency f2, as shown in FIG. A component carrier having a carrier frequency f1 which is a compatible component carrier is a high priority component carrier, and a component carrier having a carrier frequency f2 which is a non-backward compatible component carrier is a low priority component carrier. Also, as shown in FIG. 4B, the terminal uses a backward compatible component carrier with a carrier frequency f1, a backward compatible component carrier with a carrier frequency f2, and a non-backward compatible component carrier with a carrier frequency f3. When carrier aggregation is performed, the backward compatible component carrier with the carrier frequency f1 and the backward compatible component carrier with the carrier frequency f2 are set as the high priority component carriers, and the non-backward compatible component carrier with the carrier frequency f3 is set with the low priority. Component carrier. By doing so, priority is given to the component carrier that broadcasts the broadcast information that is necessary for the terminal to connect, so that the setting for each component carrier of the terminal is easily maintained.

The third example of the method for determining the priority of the component carrier is that a component carrier transmitting a physical downlink control channel (hereinafter referred to simply as “PDCCH”) is a high priority component carrier, This is a method in which a component carrier that does not transmit a PDCCH is a low priority component carrier. Since the PDCCH is a control channel including information necessary for the terminal to receive data, when the terminal cannot receive the PDCCH, the terminal does not know where the data to be received is transmitted and receives the data. Can not do it. In addition, a PDCCH transmitted on a certain component carrier may include information necessary for receiving downlink data transmitted on another component carrier. According to the third example, priority is given to the radio wave status in the component carrier that also affects other component carriers, and thus the data throughput of the terminal is easily maintained.

A fourth example of the component carrier priority determination method is a method of setting a high priority component carrier and a low priority component carrier based on the frequency priority broadcast from the base station.

The fifth example of the component carrier priority determination method is that when there is an anchor carrier, the anchor carrier is a high priority component carrier, and the carrier transmitting the PDCCH other than the anchor carrier is a low priority component carrier. In this method, measurement is not performed on component carriers that are not transmitting PDCCH.

Note that a component carrier with a high priority and a component carrier with a low priority may be determined by a method other than the above example.

In the present invention, as described in the following first to sixth embodiments, a measurement result report of a high-priority component carrier (hereinafter also referred to as “MR”) is referred to as an MR of a low-priority component carrier. Together, the terminal transmits to the base station. Hereinafter, the first to sixth embodiments will be described in order.

(First embodiment)
A radio communication system according to the first embodiment of the present invention will be described with reference to FIG. 1 and FIGS. The radio communication system according to the first embodiment includes a terminal 110 and a base station 210.

FIG. 5 is a block diagram of the terminal 110 of the first embodiment, and FIG. 6 is a block diagram of the base station 210 of the first embodiment. In the wireless communication system, the terminal 110 receives a reference signal transmitted from the base station 210 for each cell in the downlink, and sets the measurement result derived based on a predetermined calculation formula as MR, and the base station in the uplink. The function to report to 210 is provided. Further, the base station 210 allocates and manages radio resources (for example, frequency bands in the frequency domain and time domain), and determines that a handover to another cell is necessary based on the MR reported from the terminal 110. In this case, it has a function of performing a handover process, and has a role of an access point of a radio access network for the terminal 110.

[Configuration of terminal 110]
With reference to FIG. 5, the structure of the terminal 110 in 1st Embodiment is demonstrated. The terminal 110 includes a reception unit 111, a measurement result report control unit 112, a control unit 113, and a transmission unit 114.

In response to instructions sent from the control unit 113 and the measurement result report control unit 112, the reception unit 111 receives broadcast information, individual control information, reference signals, and the like transmitted from the connected cell or other cells. It has a function to receive. The receiving unit 111 outputs notification information, individual control information, and the like to the control unit 113, and outputs a reference signal to the measurement result report control unit 112.

The measurement result report control unit 112 has a function of controlling the measurement of the reference signal based on the component carrier information and the measurement setting input from the control unit 113. The measurement result report control unit 112 has a function of instructing the reception unit 111 to measure the reference signal. The component carrier information includes information indicating whether the component carrier has a high priority or a low priority, position information of a reference signal, and the like.

The measurement result report control unit 112 includes a measurement result report determination unit 1121, a carrier priority determination unit 1122, and a measurement result report creation unit 1123. The carrier priority determination unit 1122 determines whether the component carrier input from the measurement result report determination unit 1122 is a high priority component carrier or a low priority component based on the component carrier information input from the control unit 113. It has a function of determining whether it is a carrier. The carrier priority determination unit 1122 has a function of outputting a result of determining whether a component carrier is a high priority component carrier or a low priority component carrier to the measurement result report determination unit 1121.

The measurement result report determination unit 1121 has a function of managing the state of the component carrier for each component carrier. The measurement result report determination unit 1121 has a function of performing event determination. The event determination is determination of whether or not the measurement result of the reference signal input to the measurement result report control unit 112 satisfies the event standard. Then, the measurement result report determination unit 1121 has a function of setting, as an event occurrence state, the state of the component carrier determined to satisfy the event criterion by event determination, and starting TTT for the component carrier. When an event is set for each component carrier, the state of the component carrier may be referred to as an event state. The measurement result report determination unit 1121 has a function of returning the component carrier state to the initial state and terminating the TTT when the measurement result of the reference signal does not satisfy the event criteria during the TTT period.

The measurement result report creation unit 1123 has a function of creating an MR based on the measurement result of the reference signal input from the measurement result report determination unit 1121 and outputting the MR to the transmission unit 114.

The measurement result report determination unit 1121 outputs the component carrier that maintains the event occurrence state until the TTT period ends, to the carrier priority determination unit 1122. The measurement result report determination unit 1121 has a function of changing processing according to the information input from the carrier priority determination unit 1122 as to whether the component carrier is a high priority component carrier or a low priority component carrier. Have

The measurement result report determination unit 1121 has a function of setting the state of the component carrier to a waiting state when the low priority component carrier maintains the event occurrence state during the TTT period. The measurement result report determination unit 1121 has a function of returning the state of the reference signal to the initial state when the measurement result of the reference signal does not satisfy the event standard in the component carrier in the waiting state. In this way, useless MR transmissions can be reduced by not sending MRs only with the measurement results of low-priority component carriers. Thereby, the use of radio resources can be reduced, and the power consumption of the terminal can be suppressed by reducing the number of times the terminal sends MR.

If the high priority component carrier maintains the event occurrence state during the TTT, the measurement result report determination unit 1121 determines the measurement result of the component carrier and the high priority component carrier if there is a waiting component carrier. The measurement result is output to the measurement result report creation unit 1123. The measurement result report creation unit 1123 creates one MR based on the measurement result for each component carrier output from the measurement result report determination unit 1121 and outputs the MR to the transmission unit 114.

FIG. 7 is a diagram for explaining a method for reporting a measurement result in terminal 110 according to the first embodiment. FIG. 7A illustrates an example in which an event occurs in a low priority component carrier and an event occurs in a high priority component carrier after an event occurs and TTT starts. . In this case, the terminal 110 enters a waiting state when the low-priority component carrier maintains the event occurrence state during the TTT period. When the terminal 110 enters the wait state, the terminal 110 waits to create an MR of the measurement result obtained by the event, and waits for transmission to the base station 210. The terminal 110 transmits MR when maintaining the event occurrence state for the TTT period in the high priority component carrier. At this time, the terminal 110 creates one MR including the measurement result of the event that has occurred in the high priority component carrier and the measurement result in the waiting state, and sends it to the base station 210. Note that the terminal 110 individually creates the MR of the measurement result of the event that has occurred in the high priority component carrier and the MR of the measurement result of the event in the waiting state, and sends them together to the base station 210. Also good.

FIG. 7B shows an example in which an event occurs in a high-priority component carrier and an event occurs in a low-priority component carrier and TTT starts after the TTT starts. . When the high priority component carrier maintains the event occurrence state during the TTT, the terminal 110 creates an MR and sends it to the base station 210. On the other hand, if the terminal 110 maintains the event occurrence state for the TTT period in the low priority component carrier, the terminal 110 enters a waiting state. At this time, even if TTT has not started in other component carriers, the low priority component carriers enter a waiting state. That is, terminal 110 does not send MR to base station 210 only by MR of the measurement result of the low priority component carrier.

By doing in this way, the terminal 110 does not transmit MR to the base station 210 only by the measurement result of the low priority component carrier, that is, information that the base station 500 cannot determine the handover from the terminal 110. Since transmission to the base station 210 is not performed, radio resources can be effectively used and power consumption of the terminal 110 can be suppressed within a range that does not hinder handover.

Note that the measurement result report determination unit 1121 may have a function of outputting the measurement results distinguished for each event occurrence to the measurement result report creation unit 1123. Further, the measurement result report determination unit 1121 may have a function of outputting the measurement results distinguished for each event to the measurement result report creation unit 1123. In addition, the measurement result report determination unit 1121 may have a function of managing the state for each component carrier. In this case, the operation of the measurement result report determination unit 1121 is determined by whether the component carrier is a high-priority component carrier or a low-priority component carrier, and thus is not different from the above-described operation.

FIG. 8 is a diagram showing a configuration of the MR created by the measurement result report creation unit 1123 of the present embodiment. With reference to FIG. 8, a configuration example of MR when the measurement results of component carriers of different carrier frequencies are put in one MR will be described. In the MR illustrated in FIG. 8, after the serving cell RSRQ information and before the neighboring cell information, information on the carrier frequency of the neighboring cell (Carrier freq) and the number of neighboring cell information of the carrier frequency included in the MR. (Number of Neighbour cell) is inserted. By doing in this way, the measurement result of the component carrier of a some carrier frequency can be included in one MR.

Note that the measurement result report creation unit 1123 may have a function of creating an MR for each component carrier frequency based on the measurement result for each component carrier output from the measurement result report determination unit 1121. In addition, the measurement result report creation unit 1123 may have a function of receiving an input of the measurement result distinguished for each event occurrence from the measurement result report determination unit 1121 and creating an MR for each event occurrence. Furthermore, the measurement result report creation unit 1123 may have a function of receiving an input of the measurement result distinguished for each event from the measurement result report determination unit 1121 and creating an MR for each event.

Returning to FIG. 5, the control unit 113 has a function of instructing the reception unit 111 to receive notification information and individual control information transmitted from the base station 210. The control unit 113 includes a carrier information management unit 1131 that manages component carrier information used by the terminal 110 based on broadcast information and individual control information output from the reception unit 111. Further, the control unit 113 outputs the measurement setting based on the individual control information output from the reception unit 111 and the component carrier information managed by the carrier information management unit 1131 to the measurement result report control unit 112.

When receiving an inquiry about the timing of sending MR from the transmission unit 114, the control unit 113 outputs the timing to the transmission unit 114 when the uplink allocation is obtained, and when the uplink allocation is not obtained. Then, in order to obtain uplink allocation, the transmitter 114 is instructed to transmit a scheduling request to the base station 210 using radio resources for uplink control signals allocated in advance. When the control unit 113 obtains an uplink assignment from the reception unit 111, the control unit 113 instructs the transmission unit 114 to transmit a buffer status report (Buffer Status Report) to the base station 210. Thereafter, the control unit 113 receives the uplink assignment from the reception unit 111 and instructs the transmission unit 114 to transmit the MR.

When the MR is input from the measurement result report creation unit 1123 of the measurement result report control unit 112, the transmission unit 114 has a function of inquiring the control unit 113 about the timing of transmitting the MR. In addition, the transmission unit 114 has a function of transmitting data (for example, MR and control signals) to the base station 210 in accordance with an instruction from the control unit 113.

[Configuration of base station 210]
Next, the configuration of the base station 210 will be described with reference to FIG. The base station 210 includes a reception unit 211, a handover determination processing unit 212, a control unit 213, and a transmission unit 214.

The reception unit 211 outputs the MR received from the terminal 110 to the handover determination processing unit 212.

The handover determination processing unit 212 determines whether or not to hand over to another cell different from the cell being used based on the MR input from the reception unit 211. The handover determination processing unit 212 has a function of inquiring the control unit 213 for a component carrier having a high priority when receiving MR from the terminal 110 that has been input as performing carrier aggregation from the control unit 213. When the MR including only the measurement result of the high-priority component carrier is input, the handover determination processing unit 322 uses only the measurement result of the high-priority component carrier and uses different cells of the same frequency under the same base station. Handover to a different frequency cell under the same base station, handover to a same frequency cell under a different base station, handover to a different frequency cell under a different base station, or It is determined whether to add, change, or delete a component carrier in place of a handover, or to do nothing. When the MR including the measurement result of the low priority component carrier is input in addition to the measurement result of the high priority component carrier, the handover determination processing unit 212 displays the measurement result of the high priority component carrier. Taking into account the measurement results of low priority component carriers while giving priority, handover to a different cell of the same frequency under the same base station, handover to a different frequency cell under the same base station, or a different base station Hand over to a cell of the same frequency under control, hand over to a cell of a different frequency under a different base station, or add, change, delete a component carrier instead of a handover, or nothing Judge whether to do. Note that the handover determination processing unit 212 may have a function of distinguishing MR formats based on information on whether or not the terminal input from the control unit 213 is performing carrier aggregation.

Note that the MR including the measurement result of the high priority component carrier and the MR including the measurement result of the low priority component carrier may be one MR or different MRs.

The control unit 213 outputs the control information for transmitting the measurement setting to the terminal 110 and the schedule information of the reference signal to be transmitted to the terminal 110 to the transmission unit 213. In addition, when the terminal 110 is performing carrier aggregation, the control unit 213 notifies the handover determination processing unit 212 that the terminal 110 is performing carrier aggregation. The control unit 213 has a function of responding to a request from the handover determination processing unit 212 as to which of the high priority component carriers of the terminal 110 is asked.

The transmission unit 214 transmits a reference signal, control information, and the like to the terminal 110 based on the schedule information.

[Operation of communication system]
FIG. 1 is a flowchart for explaining the operation of the radio communication system according to the first embodiment. With reference to FIG. 1, the operation of the wireless communication system of the present embodiment will be described.

The terminal 110 measures the reference signal for each component carrier based on the measurement setting or taking into account other information (for example, component carrier information used for carrier aggregation) (step S101). Subsequently, the terminal 110 derives a measurement result for each component carrier based on a calculation formula determined from the measured reference signal (step S102). Next, for each component carrier, the terminal 110 determines whether or not the measurement result satisfies an event criterion determined based on the measurement setting (event determination) (step S103). In addition, in the case where the reference signal is measured for each component carrier by adding other information to the measurement setting, if the measurement target (MeasObject) of the component carrier is not defined in the measurement setting, the terminal 110 newly measures. The target may be generated or used by changing a part of the measurement target specified in the measurement setting (for example, changing the carrier frequency to the carrier frequency of the component carrier used for carrier aggregation). Good.

If the measurement result satisfies the event criteria determined based on the measurement setting (YES in step S103), the terminal 110 enters an event generation state, starts TTT on the component carrier, and continues event determination (step S104). ). If the measurement result does not satisfy the event criteria determined based on the measurement setting (NO in step S103), the process returns to step S101 and the reference signal is measured again for each component carrier.

After starting TTT in step S104, the terminal 110 determines whether or not the component carrier satisfies the event criteria determined based on the measurement settings during the TTT period (step S105). If the event criteria are not met before the end of the TTT period (NO in step S105), the process returns to step S101 and the reference signal is measured again for each component carrier.

If the component carrier maintains the event occurrence state during the TTT period (YES in step S105), the terminal 110 determines whether or not the component carrier is a high priority component carrier (step S106). ). Note that which component carrier is a high priority component carrier and which component carrier is a low priority component carrier can be referred to the control information sent from the base station 210 or the terminal 110 in advance. Is determined by the calculation method of the high-priority component carrier held by Examples of high priority component carriers are as described above.

When the component carrier that has maintained the event occurrence state during the TTT is a high-priority component carrier (YES in step S106), the terminal 110 determines whether there is a waiting-state component carrier in the low-priority component carrier. Is determined (step S107).

If it is determined in step S107 that there is a waiting component carrier in the low priority component carrier, if there is a waiting low priority component carrier (YES in step S107), the terminal 110 The MR is created including the measurement result of the low priority component carrier in the waiting state, and the MR is transmitted to the base station 210 (step S109). By doing in this way, if the terminal 110 satisfies the event criteria for the TTT period in the low-priority component carrier at the timing of sending the MR of the high-priority component carrier, the high-priority component carrier In addition to the carrier measurement results, the low-priority component carrier measurement results can also be sent to the base station 210. As a result, the base station 210 can perform the mobility of the terminal 110 on the basis of the quality of the high priority component carrier while considering the quality of the low priority component carrier. In addition to being able to perform mobility control easily, the data throughput of the terminal 110 can be improved.

In addition, when the component carrier that has maintained the event occurrence state for the TTT period is a high-priority component carrier in step S106 (YES in step 106), the terminal 110 determines that there is no waiting component carrier ( No in step S107), an MR is created only from the measurement result of the high priority component carrier, and the MR is transmitted to the base station 210 (step S110). In this way, when the terminal 110 does not satisfy the event criteria for the TTT period in the low-priority component carrier, the terminal 110 satisfies the event criteria for the TTT period in the high-priority component carrier. MR of a component carrier with high priority can be sent to the base station 210, and the base station 210 can perform mobility control of the terminal 110 simply and quickly.

When the component carrier that has maintained the event occurrence state for the TTT period is a low priority component carrier (NO in step S106), the terminal 110 maintains the event occurrence state for the TTT period in the high priority component carrier. The process waits until it completes (step S108). By doing so, since it is not the time to send the MR in the high priority component carrier that is a reference for handover, the MR of the low priority component carrier is not sent, so that useless transmission of MR can be reduced, In addition to reducing the use of radio resources, the number of times the terminal 110 sends MR can be reduced, so that the power consumption of the terminal 110 can be suppressed.

As described above, according to the radio communication system of the present embodiment, a priority is given to a plurality of component carriers used in carrier aggregation, and a measurement result report of a low priority component carrier is a high priority component. Since both are sent to the base station at the same time after waiting for the measurement results of the carrier, the quality of the high priority component carrier should be taken into consideration, and the quality of the low priority component carrier should be taken into account. In addition, the base station can easily perform the mobility control of the terminal and improve the data throughput of the terminal. Further, by suspending the measurement result report of the low priority component carrier, it is possible to reduce useless use of radio resources and to suppress the power consumption of the terminal.

(Second Embodiment)
A radio communication system according to the second embodiment of the present invention will be described with reference to FIGS. The radio communication system according to the second embodiment of the present invention includes a terminal 120 and a base station 220.

FIG. 9 is a block diagram showing a configuration of terminal 120 of the present embodiment. FIG. 10 is a block diagram of base station 220 of the present embodiment. In the radio communication system according to the present embodiment, terminal 120 receives a reference signal transmitted for each cell from base station 220 in the downlink, and outputs a measurement result derived based on a predetermined calculation formula as MR. As a function to report to the base station 220 in the uplink. Further, the base station 220 allocates and manages radio resources (for example, frequency bands in the frequency domain and time domain), and needs to be handed over to another cell based on the MR reported from the terminal 120. If it is determined that the access point of the wireless access network for the terminal 120, it has a function of performing a handover process.

[Configuration of terminal 120]
With reference to FIG. 9, the structure of the terminal 120 in 2nd Embodiment is demonstrated. The difference between the terminal 120 and the terminal 110 of the first embodiment is the configuration of the measurement result report control unit 122. Therefore, in the terminal 120 of the present embodiment, the same components as those of the terminal 110 of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

The terminal 120 includes a reception unit 111, a measurement result report control unit 122, a control unit 113, and a transmission unit 114.

The measurement result report control unit 122 includes an inter-carrier quality determination unit 1221, a homogeneous measurement result report determination unit 1222, a heterogeneous measurement result report determination unit 1223, a carrier priority determination unit 1224, and a measurement result report creation unit 1225. I have. The carrier priority determination unit 1224 has the same function as the carrier priority determination unit 1122 of the first embodiment. The same-type measurement result report determination unit 1222 has the same function as the measurement result report determination unit 1121 of the first embodiment. The measurement result report creation unit 1225 has the same function as the measurement result report creation unit 1123 of the first embodiment.

The inter-carrier quality determination unit 1221 determines whether the quality among the plurality of component carriers is the same (similar) or different based on a criterion for determining whether the quality is the same or different between the component carriers. It has a function of determining whether there is (different).

There are several criteria for judging whether the quality is the same or different among multiple component carriers. In the first example, when carrier aggregation is performed using component carriers of different frequency bands, it is determined that the quality is different between component carriers, and carrier aggregation is performed using component carriers of one frequency band. Is a criterion for determining that the quality is similar between component carriers. For example, when carrier aggregation is performed using a component carrier belonging to the 800 MHz band and a component carrier belonging to the 2 GHz band, it is determined that the quality is different between the component carriers, and only the component carrier belonging to the 800 MHz band is used. When carrier aggregation is performed, it is determined that the quality is similar between component carriers.

In the second example, when carrier aggregation is performed using component carriers having adjacent carrier frequencies, it is determined that the quality is similar between the component carriers, and component carriers having carrier frequencies separated from each other are determined. When carrier aggregation is used, this is a criterion for determining that the quality differs between component carriers.

In the third example, when carrier aggregation is performed using component carriers whose carrier frequency is within a difference of k MHz (for example, k = 100), it is determined that the quality is similar between the component carriers, When carrier aggregation is performed using a component carrier having a carrier frequency difference of k MHz or more, this is a criterion for determining that the quality differs between component carriers.

The fourth example compares the measurement results of the reference signal for each component carrier. If the quality difference between component carriers is less than mdB (eg, m = 30), the quality is similar between the component carriers. If the quality difference between component carriers is greater than or equal to mdB, the criterion is that the quality is determined to be different between component carriers.

In the fifth example, when carrier aggregation is performed using component carriers having different cell sizes, it is determined that the quality is different between component carriers, and carrier aggregation is performed using component carriers having similar cell sizes. In this case, it is a criterion that it is determined that the quality is similar between the component carriers. In this case, it is necessary to notify the terminal 120 from the base station 220 that the cell sizes are different. For example, the notification information can be included in the notification or can be notified in the measurement target (MeasObject). Note that the base station 220 may notify the terminal 120 that the cell size is different by a method other than the above.

It should be noted that the criteria for determining whether the quality is the same or different between component carriers may be criteria other than the above five examples.

Based on the above criteria, the inter-carrier quality determination unit 1221 determines whether the quality between component carriers is the same type (similar) or different type (different), and the quality between component carriers is the same type. If it is determined that there is a reference signal, the measurement result of the reference signal is input to the homogeneous measurement result report determination unit 1222, and if it is determined that the quality between the component carriers is different, the measurement result of the reference signal is input to the heterogeneous measurement result report determination unit 1223. To do. By doing in this way, the process of the terminal 120 can be changed between the case where the quality is similar between the component carriers and the case where the quality is different between the component carriers.

The heterogeneous measurement result report determination unit 1223 has a function of managing the state of the component carrier for each component carrier. When the inter-carrier quality determination unit 1221 determines that the quality between component carriers is different, the heterogeneous measurement result report determination unit 1223 receives an input of the reference signal measurement result.

The heterogeneous measurement result report determination unit 1223 has a function of performing event determination as to whether or not the input reference signal measurement result satisfies the event standard. Then, the heterogeneous measurement result report determination unit 1223 has a function of setting, as an event occurrence state, the state of the component carrier determined to satisfy the event criterion by event determination, and starting TTT in the component carrier. When an event is set for each component carrier, the state of the component carrier may be referred to as an event state. The heterogeneous measurement result report determination unit 1223 has a function of returning the component carrier state to the initial state and terminating the TTT when the measurement result of the reference signal does not satisfy the event standard during the TTT period.

The heterogeneous measurement result report determination unit 1223 outputs, to the carrier priority determination unit 1224, the component carrier that maintains the event occurrence state during the TTT period. The measurement result report control unit 122 has a function of changing processing according to the determination in the carrier priority determination unit 1224 whether the component carrier is a high priority component carrier or a low priority component carrier. In this way, processing can be changed between a high priority component carrier and a low priority component carrier.

The heterogeneous measurement result report determination unit 1223 determines whether or not TTT is started in another component carrier when the event occurrence state is maintained for the TTT period in the low priority component carrier. The heterogeneous measurement result report determination unit 1223 has a function of setting the state of the component carrier to a waiting state when TTT is started in another component carrier. By doing in this way, MR can be transmitted according to the transmission timing of MR in other component carriers. Then, since the MR reaches the base station 220 at the same time, the base station 220 can easily determine the handover.

The heterogeneous measurement result report determination unit 1223 has a function of returning the state to the initial state when the measurement result of the reference signal does not satisfy the event standard in the component carrier in the waiting state. When the heterogeneous measurement result report determination unit 1223 determines that TTT is not started on another component carrier, the heterogeneous measurement result report determination unit 1223 confirms whether there is a component carrier in a waiting state. When there is a waiting component carrier, the heterogeneous measurement result report determination unit 1223 outputs the measurement result of the waiting component carrier and the measurement result of the component carrier to the measurement result report creation unit 1225. When there is no waiting component carrier, the heterogeneous measurement result report determination unit 1223 outputs the measurement result of the component carrier to the measurement result report creation unit 125.

In the high-priority component carrier, the heterogeneous measurement result report determination unit 1223 maintains the event occurrence state during the TTT period, and if there is a waiting component carrier, the measurement result of the waiting component carrier and the high priority The component carrier measurement results are output to the measurement result report creation unit 1225. The heterogeneous measurement result report determination unit 1223 maintains the measurement result of the high-priority component carrier when there is no component carrier in the waiting state when the event generation state is maintained for the TTT period in the high-priority component carrier. Output to the measurement result report generator 1225.

The measurement result report creation unit 1225 creates one MR based on the measurement results for each component carrier output from the same type measurement result report determination unit 1222 and the different type measurement result report determination unit 1223, and outputs the MR to the transmission unit 114. . The measurement result report control unit 122 has a function of creating an MR for each component carrier frequency based on the measurement results for each component carrier output from the same type measurement result report determination unit 1222 and the different type measurement result report determination unit 1223. You may have. Further, the heterogeneous measurement result report determination unit 1223 and the same type measurement result report determination unit 1222 may have a function of outputting the measurement results distinguished for each event occurrence to the measurement result report creation unit 1225. Further, the heterogeneous measurement result report determination unit 1223 and the same type measurement result report determination unit 1222 may have a function of outputting the measurement results distinguished for each event to the measurement result report creation unit 1225.

FIG. 11 is a diagram for explaining a method of reporting a measurement result in the terminal 120 when the quality among component carriers is different. With reference to FIG. 11, a method of reporting a measurement result in terminal 120 when the quality between the component carriers described above is different will be described.

FIG. 11A shows that after an event occurs in a low priority component carrier and the TTT starts, an event occurs in a high priority component carrier having a quality different from that of the low priority component carrier. The example in the case of starting TTT is shown. In this case, when an event occurs in a low-priority component carrier and TTT is started, an event occurs in a high-priority component carrier and TTT is started. Wait for MR transmission until the TTT of the priority component carrier ends, and at the timing of transmitting MR for the high priority component carrier, the low priority component carrier that was in a waiting state with the MR of the high priority component carrier Are combined into a single MR and transmitted to the base station 220. In addition, Fig.11 (a) is the same figure as Fig.7 (a). That is, the function and operation of the homogeneous measurement result report determination unit 1222 are the same as the function and operation of the measurement result report determination unit 1121 according to the first embodiment. That is, when the inter-carrier quality determination unit 1221 determines that the quality between component carriers is the same type, the same-type measurement result report determination unit 1222 receives the measurement result of the reference signal, and uses the method of FIG. Trigger MR transmission. In other words, if an event occurs in the high priority component carrier after the event occurs in the low priority component carrier and the TTT starts after the event occurs in the low priority component carrier, the terminal 120 Regardless of whether the quality is the same or different, the operations of FIG. 11A and FIG. 7A are performed.

FIG. 11B shows that after an event occurs in a high priority component carrier and TTT is started, an event occurs in a low priority component carrier having a quality different from that of the high priority component carrier. The example in the case of starting TTT is shown. When the terminal 120 maintains the event occurrence state for the TTT period in the high priority component carrier, the terminal 120 creates an MR and sends it to the base station 220. On the other hand, when the terminal 120 maintains the event occurrence state for the TTT period in the low priority component carrier, the terminal 120 creates an MR and sends it to the base station 220. That is, in this case, the MR of the low-priority component carrier is independently created and transmitted without waiting for the timing when the next high-priority component carrier creates and transmits the MR.

In terminal 120 of the present embodiment, when it is known that the quality between component carriers is different in advance, measurement result report control unit 122 omits inter-carrier quality determination unit 1221 and similar measurement result report determination unit 1222. it can.

[Configuration of Base Station 220]
With reference to FIG. 10, the structure of the base station 220 in 2nd Embodiment is demonstrated. The difference between the base station 220 and the base station 210 of the first embodiment is the configuration of the handover determination processing unit. Therefore, in the base station 220 of the present embodiment, the same components as those of the base station 210 of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. .

The base station 220 includes a reception unit 211, a handover determination processing unit 222, a control unit 213, and a transmission unit 214.

In addition to the function of the handover determination processing unit 212 of the first embodiment, the handover determination processing unit 222 receives an MR including only the measurement result of the low-priority component carrier. When MR including the measurement result of the component carrier is not sent, only the measurement result of the low priority component carrier is handed over to a different cell of the same frequency under the same base station, or a different frequency under the same base station Handover to another cell, handover to a cell of the same frequency under a different base station, handover to a cell of a different frequency under a different base station, or addition, change, or deletion of a component carrier instead of a handover It has a function to determine whether to do any of the above or do nothing. Further, when the handover determination processing unit 222 affects the cell used by the high priority component carrier, the handover determination processing unit 222 sends the MR of the high priority component carrier using the MR of the low priority component carrier as a trigger. May have a function of instructing the terminal 120. In addition, the handover determination processing unit 222 assigns a measurement gap (Measurement Gap) to the low priority component carrier and measures different carrier frequencies so as not to affect the high priority component carrier being used. As described above, it may have a function of sending the measurement setting to the terminal 120.

[Operation of communication system]
FIG. 12 is a flowchart for explaining the operation of the radio communication system according to the second embodiment. With reference to FIG. 12, the operation of the wireless communication system of the present exemplary embodiment will be described.

The terminal 220 determines whether or not the reception quality of the component carrier used for carrier aggregation differs between component carriers (step S201). If the terminal 120 determines that the reception qualities are similar between component carriers (NO in step S201), the terminal 120 performs the same operation as in the first embodiment shown in FIG. 1 (step S202). If the terminal 120 determines that the reception quality differs between component carriers (YES in step S202), the terminal 120 performs the following operation.

The terminal 120 measures the reference signal for each component carrier based on the measurement setting or taking into account other information (for example, information on the component carrier to which the PDCCH is transmitted and the component carrier to which the PDCCH is not transmitted). (Step S203). Subsequently, the terminal 120 derives a measurement result for each component carrier (step S204). Next, the terminal 120 determines, for each component carrier, whether or not the measurement result satisfies an event criterion determined based on the measurement setting (step S205).

When the measurement result satisfies the event criteria determined based on the measurement settings, the terminal 120 enters an event generation state, starts TTT in the component carrier, and continues event determination (step S206). If the measurement result does not satisfy the event criteria determined based on the measurement setting (NO in step S205), the process returns to step S203, and the reference signal is measured again for each component carrier.

After starting TTT in step S206, the terminal 120 determines whether or not the component carrier satisfies the event criteria determined based on the measurement settings during the TTT period (step S207). If the event criteria are not met before the end of the TTT period (NO in step S207), the process returns to step S203 and the reference signal is measured again for each component carrier.

In the component carrier, when the event occurrence state is maintained during the TTT period (YES in step S207), the terminal 120 determines whether or not the component carrier is a high priority component carrier (step S208). ). Note that which component carrier is a high priority component carrier and which component carrier is a low priority component carrier is referred to the control information sent from the base station 220, or in advance the terminal 120 Is determined by the calculation method of the high-priority component carrier held by the. Examples of high priority component carriers are as described above.

If the component carrier that has maintained the event occurrence state during the TTT is a high-priority component carrier (YES in step S208), the terminal 120 determines whether there is a waiting component carrier in the low-priority component carrier. Is determined (step S209).

If it is determined in step S209 that there is a waiting component carrier in the low priority component carrier, if there is a waiting low priority component carrier (YES in step S209), the terminal 120 The MR is created including the measurement result of the low priority component carrier in the waiting state, and the MR is transmitted to the base station 220 (step S210). By doing in this way, if the terminal 120 satisfies the event criteria for the TTT period in the low-priority component carrier at the timing of sending the MR of the high-priority component carrier, the high-priority component carrier In addition to the carrier measurement results, the low-priority component carrier measurement results can also be sent to the base station 220. As a result, the base station 220 can perform the mobility of the terminal 120 based on the quality of the component carrier with high priority while considering the quality of the component carrier with low priority. In addition to being able to perform mobility control easily, the data throughput of the terminal 120 can be improved.

In addition, in step S208, when the component carrier that has maintained the event occurrence state for the TTT period is a high priority component carrier (YES in step S208), the terminal 120 determines that there is no waiting component carrier ( In step S209, NO, an MR is created only from the measurement result of the high priority component carrier, and the MR is transmitted to the base station 220 (step S211). By doing in this way, when the terminal 120 does not satisfy the event criteria for the TTT period in the low priority component carrier, the terminal 120 satisfies the event criteria for the TTT period in the high priority component carrier. The MR of the high priority component carrier can be sent to the base station 220, and the base station 220 can perform the mobility control of the terminal 120 simply and quickly.

When the component carrier that has maintained the event occurrence state during the TTT is a low-priority component carrier (NO in step S208), the terminal 120 determines whether or not TTT has started in another component carrier. (Step S212).

If the TTT has started in another component carrier (YES in step S212), the state of the low priority component carrier is set to a waiting state (step S213). In this way, since MR can be transmitted in accordance with MR transmission timing in other component carriers, MR arrives at the base station 220 at the same time, and the base station 220 easily performs handover determination. be able to.

In step S212, if TTT has not started in another component carrier (NO in step S212), it is determined whether there is a waiting component carrier (step S214).

If there is a waiting component carrier (YES in step S214), the terminal 120 creates a waiting component carrier and an MR of the component carrier and transmits them to the base station 220 (step S215). Note that the component carrier in the waiting state and the MR of the component carrier may be separate MRs or may be the same MR.

On the other hand, if there is no waiting component carrier in step S214 (NO in step S214), the terminal 120 creates an MR of the component carrier and transmits it to the base station 220 (step S216).

As described above, in this embodiment, the method for determining whether to transmit MR is changed depending on whether the quality between component carriers is similar or different. When the quality between component carriers is similar, the same determination method as in the first embodiment is used, and when the quality between component carriers is different, a determination method different from that in the first embodiment is used.

In this way, when the quality between the component carriers is similar, there is a high probability that the MR of the high priority component carrier is sent in the situation where the MR of the low priority component carrier is sent. By sending MRs of low-priority component carriers at the same time as MRs of high-priority component carriers are sent, the base station can receive the necessary MRs at almost the same timing and easily determine handover Can be done.

On the other hand, when the quality of the component carriers is different, in the situation where the MR of the low priority component carrier is sent, the probability that the MR of the high priority component carrier is sent is similar to the quality between the component carriers. Therefore, it is possible to quickly hand over a component carrier having a poor radio wave condition to another component carrier by improving the data throughput of the terminal by transmitting MR even with only a low priority component carrier. be able to.

(Third embodiment)
A radio communication system according to a third embodiment of the present invention will be described with reference to FIGS. The radio communication system according to the third embodiment of the present invention includes a terminal 130 and a base station (not shown).

FIG. 13 is a block diagram showing a configuration of terminal 130 according to the present embodiment. In the radio communication system according to the present embodiment, terminal 130 receives a reference signal transmitted from the base station in the downlink for each cell, and uses MR as a measurement result derived based on a predetermined calculation formula. It has a function to report to the base station on the uplink. Also, the base station allocates and manages radio resources (for example, frequency bands in the frequency domain and time domain), and determines that a handover from the MR reported from the terminal 130 to another cell is necessary. It has a function of performing a handover process, and serves as an access point of a radio access network for the terminal 130.

[Configuration of terminal 130]
With reference to FIG. 13, the structure of the terminal 130 of this Embodiment is demonstrated. The terminal 130 is different from the terminal 110 of the first embodiment in the configuration of the measurement result report control unit. Therefore, in the terminal 130 of this Embodiment, the same reference number is attached | subjected about the component same as the component of the terminal 110 of 1st Embodiment, and the detailed description is abbreviate | omitted.

The terminal 130 includes a receiving unit 111, a measurement result report control unit 132, a control unit 113, and a transmission unit 114.

Similar to the measurement result report control unit 112 of the first embodiment, the measurement result report control unit 132 includes a measurement result report determination unit 1321, a carrier priority determination unit 1322, and a measurement result report creation unit 1323. ing. The measurement result report determination unit 1321 includes a TTT shortening unit 1324 and a determination processing unit 1325.

The carrier priority determination unit 1322 determines whether the component carrier is a high priority component carrier or a low priority component carrier in the same manner as the carrier priority determination unit 1122 of the first embodiment. To do. Similarly to the measurement result report creation unit 1123 of the first embodiment, the measurement result report creation unit 1323 creates one MR for one component carrier frequency, or creates one MR for a plurality of component carrier frequencies. The generated MR is output to the transmission unit 114.

In addition to the function of the measurement result report determination unit 1121 in the first embodiment, the measurement result report determination unit 1321 determines the carrier priority of component carrier information of a component carrier when TTT starts for that component carrier. A function of outputting to the unit 1322; The measurement result report determination unit 1321 changes processing according to the determination result input from the carrier priority determination unit 1322 as to whether the component carrier is a high priority component carrier or a low priority component carrier. It has a function.

When the TTT starts in the high priority component carrier, the determination processing unit 1325 of the measurement result report determination unit 1321 outputs a notification to the TTT shortening unit 1324 that the TTT has started in the high priority component carrier. When the TTT starts in the priority component carrier, the TTT shortening unit 1324 outputs a notification that the TTT has started in the low priority component carrier. Also, the determination processing unit 1325 returns the TTT shortening unit 1324 to the TTT shortening unit 1324 when returning the component carrier state to the initial state or creating the MR for the component carrier notified of the start of TTT to the TTT shortening unit 1324. It has a function of outputting an instruction to delete the component carrier information of the component carrier returned to the initial state or the component carrier that created the MR. When the determination processing unit 1325 is instructed by the TTT shortening unit 1324 to shorten the TTT in the high priority component carrier, the determination processing unit 1325 has a function of shortening the TTT of the corresponding component carrier.

When the TTT shortening unit 1324 receives notification from the determination processing unit 1325 that TTT has started in the low priority component carrier, the TTT shortening unit 1324 adds 1 to the count of the low priority component carrier while retaining the component carrier information. It has a function. When the determination processing unit 1325 instructs to delete the component carrier information, the count of the low priority component carriers is subtracted by the number of the low priority component carriers holding the component carrier information. It has a function. The initial value of the low-priority component carrier count is 0.

Upon receiving notification from the determination processing unit 1325 that TTT has started in the high priority component carrier, the TTT shortening unit 1324 adds 1 to the count of the high priority component carrier while retaining the component carrier information. It has a function. Further, when the determination processing unit 1325 instructs to delete the target component carrier information, the count of the high priority component carriers is subtracted by the number of the high priority component carriers holding the component carrier information. It has the function to do. The initial value of the high-priority component carrier count is 0.

When the count of high-priority component carriers is 1 or more, the TTT shortening unit 1324 determines whether the count of low-priority component carriers is x or more (for example, x = 1) or more, and x or more If it is determined that the TTT of the high priority component carrier is shortened, the determination processing unit 1325 is instructed to shorten the TTT of the high priority component carrier, and the count of the high priority component carrier is returned to the initial value. The TTT shortening unit 1324 has a function of determining whether or not the count of the low-priority component carrier is x or more as needed when the count of the high-priority component carrier is 1 or more. Note that the value of x may be held in advance by the terminal 130 or may be notified from the base station to the terminal 130.

When the measurement result report determination unit 1321 manages a plurality of cells having the same carrier frequency, the determination processing unit 1325 outputs a notification that TTT has started in one component carrier to the TTT shortening unit 1324. After that, when the TTT starts in a different cell with the same carrier frequency, the TTT shortening unit 1324 may not be notified of the start of the TTT. In this way, when TTT is started in a plurality of cells having the same carrier frequency, it is possible to notify only that TTT has started on one component carrier, and to keep the weight for counting between carrier frequencies equal. Can do.

FIG. 14 is a diagram for explaining a method of reporting a measurement result in the terminal 130 according to the third embodiment. As described above, when the TTT shortening unit 1324 determines that the count of the low-priority component carrier is equal to or greater than x when the count of the high-priority component carrier is equal to or greater than 1, the TTT shortening unit 1324 Although it is instructed to shorten the TTT of the priority component carrier, in the following description, a method of reporting a measurement result with the above x set to x = 1 will be described.

FIG. 14A shows an example in which an event occurs in a low priority component carrier and an event occurs in a high priority component carrier after an event occurs and TTT starts. . When starting TTT in the high priority component carrier, if TTT has started in the low priority component carrier, the TTT value of the high priority component carrier is shortened to gTTT. gTTT is a value obtained by adding g1 (g1 is a real number from 0 to 1) to the value of TTT, or a value obtained by subtracting g2 (g2 is an integer shorter than the value of TTT) from the value of TTT. g1 and g2 are sent from the base station or held in advance by the terminal 130. Note that the terminal 130 may have a function of obtaining g1 and g2 according to the value of TTT.

When the terminal 130 maintains the event occurrence state for the gTTT period with the high priority component carrier, the terminal 130 creates an MR and transmits it to the base station. The low-priority component carrier enters a waiting state if it maintains the event occurrence state for the period of TTT.

FIG. 14B shows an example in which TTT is started in a low priority component carrier after an event occurs in the high priority component carrier and TTT is started. When TTT is started with a low-priority component carrier after starting TTT in the high-priority component carrier, the TTT value of the high-priority component carrier is shortened to hTTT. hTTT is a value obtained by adding h1 (h1 is a real number from 0 to 1) to the value of TTT, or a value obtained by subtracting h2 (h2 is an integer shorter than the value of TTT) from the value of TTT. h1 and h2 are sent from the base station or held in advance by the terminal 130. Note that the terminal 130 may have a function of obtaining h1 and h2 according to the value of TTT.

When the terminal 130 maintains the event occurrence state for the hTTT period with the high-priority component carrier, the terminal 130 creates an MR and transmits it to the base station.

FIG. 14 (c) shows an example in which TTT is started in the low priority component carrier after elapse of a period longer than hTTT while maintaining the event occurrence state in the high priority component carrier. Yes. In this case, since the high-priority component carrier has already passed the hTTT period, when the low-priority component carrier TTT starts, the procedure immediately moves to the procedure for creating the MR, and the base station Send. The low-priority component carrier enters a waiting state if it maintains the event occurrence state for the period of TTT.

As described above, according to terminal 130 of the present embodiment, the radio wave condition of the base station is estimated from the radio wave condition of the low-priority component carrier, and the MR of the measurement result of the high-priority component carrier is conventionally obtained. Since it can be sent to the base station as soon as possible, the base station can make a handover decision at an earlier timing than before. As a result, the terminal 130 can be handed over to a cell with a better radio wave condition sooner than before, and data throughput can be improved.

(Fourth embodiment)
A radio communication system according to the fourth embodiment of this invention will be described with reference to FIGS. The radio communication system according to the fourth embodiment of the present invention includes a terminal 140 and a base station 240.

FIG. 15 is a block diagram of the terminal 140 of the present embodiment, and FIG. 16 is a block diagram of the base station 240 of the present embodiment. In the wireless communication system, the terminal 140 receives the reference signal transmitted from the base station 240 for each cell in the downlink, and sets the measurement result derived based on a predetermined calculation formula as MR, and the base station in the uplink. The function to report to. In addition, the base station 240 performs allocation and management of radio resources (for example, frequency bands in the frequency domain and time domain), and determines that a handover from the MR reported from the terminal 140 to another cell is necessary. And a function of performing a handover process, and serves as an access point of a radio access network for the terminal 140.

[Configuration of terminal 140]
With reference to FIG. 15, the structure of the terminal 140 of this Embodiment is demonstrated. The terminal 140 of the present embodiment differs from the terminal 130 of the third embodiment in the configuration of the control unit and the measurement result report control unit. Therefore, in the terminal 140 of this embodiment, the same components as those of the terminal 130 of the third embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

The terminal 140 includes a reception unit 111, a measurement result report control unit 142, a control unit 143, and a transmission unit 114.

The control unit 143 includes a carrier information management unit 1431 and a base station subordinate cell list management unit 1432. The carrier information management unit 1431 has the same function as the carrier information management unit 1331 of the third embodiment. The base station subordinate cell list management unit 1432 manages information related to the list of cells subordinate to the base station. The cell list information includes, for example, a cell PCI list. The cell list information is transmitted to the terminal by adding a flag indicating the same base station to the neighbor cell list in the system information sent from the base station to the terminal. The base station subordinate cell list management unit 1432 has a function of managing to which base station a cell belongs.

When the control unit 143 receives an inquiry from the measurement result report control unit 142 as to which base station the cell belongs to, the base station subordinate cell list management unit 1432 determines which base station the target cell belongs to. And the base station information of the base station is output to the measurement result report control unit 142.

The measurement result report control unit 142 includes a measurement result report determination unit 1421, a carrier priority determination unit 1422, and a measurement result report creation unit 1423. In addition to the function of the measurement result report control unit 132 of the third embodiment, the measurement result report control unit 142 has a function of inquiring the control unit 143 to which base station the cell that started the TTT belongs. The measurement result report determination unit 1421 has a function of receiving base station information of a base station to which a cell that has started TTT belongs, input from the control unit 143.

The measurement result report determination unit 1421 includes a base station-specific TTT shortening unit 1424 instead of the TTT shortening unit 1324 as compared with the function of the measurement result report determination unit 1321 of the third embodiment. The measurement result report determination unit 1421 includes a determination processing unit 1425 in addition to the base station specific TTT shortening unit 1424. When the TTT starts in the component carrier, the determination processing unit 1425 queries the control unit 143 to which base station the cell from which the TTT has started belongs, and the cell from which the TTT has started received from the control unit 143 belongs The base station information of the base station is input to the base station-specific TTT shortening unit 1424 together with a notification that TTT has started in the component carrier. In addition, in the component carrier in which TTT has already started, the determination processing unit 1425 causes the control unit 143 to determine which base station has the cell in which the TTT has started, when another cell satisfies the event criterion and TTT starts. The base station information of the base station to which the TTT started cell received from the control unit 143 is notified to the base station-specific TTT shortening unit 1424 together with a notification that the TTT has started in the component carrier. Has a function to input.

The base station-specific TTT shortening unit 1424 has a function of managing a low-priority component carrier count and a high-priority component carrier count for each base station. When the base station-specific TTT shortening unit 1424 receives notification from the determination processing unit 1425 that the TTT has started in the low priority component carrier together with the base station information, the base station It has a function of adding 1 to the count of low priority component carriers of the base station corresponding to the information. When a plurality of base stations are included in the base station information, the base station TTT shortening unit 1424 adds 1 to the low-priority component carrier count for each base station. When the base station-specific TTT shortening unit 1424 receives an instruction to delete the component carrier information from the determination processing unit 1425 together with the base station information, the low priority component carrier of the base station corresponding to the base station information is received. The number of the component carriers that have been instructed to be deleted is subtracted from the count. The initial value of the low-priority component carrier count is 0.

When the TTT shortening unit 1424 for each base station receives notification from the determination processing unit 1425 that the TTT has started in the high priority component carrier together with the base station information, the base station TTT shortening unit 1424 holds the component carrier information and It has a function of adding 1 to the count of high priority component carriers of the base station corresponding to the station information. In addition, when receiving an instruction to delete the component carrier information from the determination processing unit 1425 together with the base station information, the base station-specific TTT shortening unit 1424 deletes the base station from the count of the high priority component carriers of the base station. It has a function of subtracting the count by the number of component carriers that have been detected. The initial value of the high-priority component carrier count is 0.

If the count of high-priority component carriers is 1 or more, the base station-specific TTT shortening unit 1424 determines whether the count of low-priority component carriers of the same base station is x (for example, x = 1) or more. If it is determined that x is equal to or greater than x, the determination processing unit 4035 is instructed to shorten the TTT of the high priority component carrier of the corresponding base station, and the high priority component carrier of the base station is determined. Has a function of resetting the count to the initial value. The base station-specific TTT shortening unit 1424 has a function of determining whether or not the count of the low-priority component carriers of the same base station is greater than or equal to x when the count of the high-priority component carriers is 1 or more. .

[Configuration of Base Station 240]
With reference to FIG. 16, the structure of the base station 240 of this Embodiment is demonstrated. The difference of the base station 240 of this Embodiment from the base station 210 of 1st Embodiment is a structure of a control part. Therefore, in the base station 240 of the present embodiment, the same reference numerals are assigned to the same components as those of the base station 210 of the first embodiment, and detailed description thereof is omitted. .

The base station 240 includes a reception unit 211, a handover determination process 212 unit, a control unit 243, and a transmission unit 214. The control unit 243 includes a base station subordinate cell list management unit 2431. The base station subordinate cell list management unit 2431 manages a list of cells subordinate to the base station. The cell list information includes, for example, a cell PCI list. The base station subordinate cell list management unit 2431 outputs this information to the transmission unit 214 as control information.

FIG. 17 is a diagram for explaining a method of reporting a measurement result in the terminal 140 according to the fourth embodiment. As described above, the base station-specific TTT shortening unit 1424 of the terminal 140 determines that the count of low-priority component carriers of the same base station is x or more when the count of high-priority component carriers is 1 or more. When the determination is made, the determination processing unit 1425 is instructed to shorten the TTT of the high priority component carrier. In the following description, a method of reporting the measurement result with the above x set to x = 1 will be described.

FIG. 17 (a) shows that, in the low-priority component carrier, the radio wave condition in the base station A is improved, an event occurs, and after starting TTT, the high-priority component carrier in the same base station A An example in which an event occurs and TTT starts due to an improved radio wave condition is shown. When a TTT is started in a high priority component carrier, an event has occurred in the low priority component carrier due to radio wave conditions in the same base station as the high priority component carrier, and the TTT has started The TTT value of the high priority component carrier is shortened to gTTT. gTTT is obtained by the same method as in the third embodiment. When terminal 140 maintains an event occurrence state for a gTTT period with a high priority component carrier, terminal 140 creates an MR and transmits it to the base station. The low-priority component carrier enters a waiting state if it maintains the event occurrence state for the period of TTT.

In addition, in the high-priority component carrier, the radio wave condition in the base station A is improved, and after the event occurs and TTT is started, the radio wave condition in the base station A is improved in the low-priority component carrier. When an event occurs and TTT is started, the TTT value of the high priority component carrier is set to hTTT as shown in FIG. 14B, or low priority as shown in FIG. 14C. When an event occurs for a component carrier of a certain degree, an MR of a component carrier with a high priority is immediately created and transmitted without waiting for completion of TTT of the component carrier with a high priority. hTTT is obtained by the same method as in the third embodiment. Since other operations are the same as those in the third embodiment, the description thereof is omitted.

FIG. 17B shows a case where the base station B (base station B) in the high-priority component carrier after the occurrence of an event due to an improvement in the radio wave condition in the base station A in the low-priority component carrier and the start of TTT. An example is shown in which an event occurs and TTT is started when the radio wave condition at a base station different from station A is improved. When the terminal 140 starts TTT in a high-priority component carrier, an event occurs in the low-priority component carrier due to a radio wave condition in a base station different from the base station of the high-priority component carrier. When the TTT is started, the TTT value of the high priority component carrier is not shortened. When the terminal 140 maintains the event occurrence state for the TTT period with the high priority component carrier, the terminal 140 creates an MR and transmits the MR to the base station 240. The low-priority component carrier enters a waiting state if it maintains the event occurrence state for the period of TTT.

Note that the terminal 140 receives a radio wave condition at the base station B in the high-priority component carrier, an event occurs, and after starting TTT, the radio wave condition at the base station A in the low-priority component carrier. When an event occurs and TTT is started, the TTT value of the high priority component carrier is not shortened. When terminal 140 maintains an event occurrence state for a TTT period with a high-priority component carrier, terminal 140 creates an MR and transmits it to the base station. The low-priority component carrier enters a waiting state if it maintains the event occurrence state for the period of TTT.

As described above, in the present embodiment, when the base station 240 sends cell information under the control of the base station to the terminal 140, the terminal 140 can generate an event on a low-priority component carrier under the same base station. By applying the third embodiment to the above, when the quality of the same base station is improved in the high priority component carrier and the low priority component carrier, the TTT of the high priority component carrier is shortened. Therefore, the handover to the base station that improves the data throughput of the terminal 140 is performed as compared with the above-described third embodiment.

(Fifth embodiment)
A radio communication system according to a fifth embodiment of this invention will be described with reference to FIG. 18 and FIG. A radio communication system according to the fifth embodiment of the present invention includes a terminal and a base station.

FIG. 18 is a block diagram showing a configuration of terminal 150 of the present embodiment. In the radio communication system according to the present embodiment, terminal 150 receives a reference signal transmitted from the base station in the downlink for each cell, and uses MR as a measurement result derived based on a predetermined calculation formula. It has a function to report to the base station on the uplink. In addition, the base station allocates and manages radio resources (for example, frequency bands in the frequency domain and time domain), and determines that handover from the MR reported from the terminal 150 to another cell is necessary. It has a function of performing a handover process, and serves as an access point of a radio access network for the terminal 150.

[Configuration of terminal 150]
With reference to FIG. 18, the structure of the terminal 150 of this Embodiment is demonstrated. The terminal 150 is different from the terminal 110 of the first embodiment in the configuration of the measurement result report control unit. Therefore, in terminal 150 of this embodiment, the same reference numerals are assigned to the same components as those of terminal 110 of the first embodiment, and detailed description thereof is omitted.

The terminal 150 includes a reception unit 111, a measurement result report control unit 152, a control unit 113, and a transmission unit 114.

Similar to the measurement result report control unit 112 of the first embodiment, the measurement result report control unit 152 includes a measurement result report determination unit 1521, a carrier priority determination unit 1522, and a measurement result report creation unit 1523. ing. The measurement result determination unit 1521 includes a low priority TTT extension unit 1524 and a determination processing unit 1525.

The carrier priority determination unit 1522 determines whether the component carrier is a high priority component carrier or a low priority component carrier in the same manner as the carrier priority determination unit 1122 of the first embodiment. To do. Similar to the measurement result report creation unit 1123 of the first embodiment, the measurement result report creation unit 1523 creates one MR for one component carrier frequency, or creates one MR for a plurality of component carrier frequencies. The generated MR is output to the transmission unit 114.

In addition to the function of the measurement result report determination unit 1121 of the first embodiment, the measurement result report determination unit 1521 determines the carrier priority of component carrier information of a component carrier when TTT starts for that component carrier. A function of outputting to the unit 1522; The measurement result report determination unit 1521 changes processing according to the determination result input from the carrier priority determination unit 1522 as to whether the component carrier is a high priority component carrier or a low priority component carrier. It has a function.

The determination processing unit 1525 of the measurement result report determination unit 1521 outputs the currently set TTT value to the low priority TTT extension unit 1524 when the component carrier in which the event has occurred is a low priority component carrier. . When the extended TTT period is input from the low priority TTT extension unit 1524, the determination processing unit 1525 replaces the TTT of the corresponding component carrier with the input TTT period. It should be noted that when the TTT period extended from the low priority TTT extension unit 1524 is input, the determination processing unit 1525 changes the TTT value indicated by the control information, or the terminal 150 itself determines the TTT value. Use the same extended TTT period for the low priority component carrier until the reference TTT value changes, and every time TTT starts on the low priority component carrier, the low priority You may not make an inquiry to the TTT extension.

Also, the determination processing unit 1525 may inquire the low priority TTT extension unit 1524 about the TTT of the low priority component carrier in advance before the TTT starts in the low priority component carrier. In this case, when an inquiry is input from the determination processing unit 1525 regarding the TTT period of the low priority component carrier, the low priority TTT extension unit 1524 determines the TTT period of the low priority component carrier, The determination processing unit 1525 has a function of outputting the TTT period of the low priority component carrier.

When the reference TTT value is input, the low priority TTT extension unit 1524 adds j1 (for example, j1 = 1.5) to the reference TTT value, and extends the low priority component carrier. Calculate the TTT value obtained. j1 is a real value and is included in the control information transmitted from the base station or determined in advance by the terminal 150. Here, j1 may be a positive integer. The extended TTT value of the low priority component carrier may be calculated by adding j2 (for example, j2 = 200) to the reference TTT value. Here, j2 is a positive integer or real number, and is included in the control information transmitted from the base station or determined in advance by the terminal 150. Note that the terminal 150 may have a function of obtaining j1 and j2 according to the value of TTT.

FIG. 19 is a diagram for explaining a method for reporting a measurement result in the terminal 150 according to the fifth embodiment. FIG. 19 shows an example in which TTT is started in a high priority component carrier after starting TTT in a low priority component carrier. In this case, when an event occurs in a component carrier having a low priority, the value of TTT is lengthened to jTTT.

In this way, since the TTT value in the low priority component carrier can be increased, the probability of maintaining the event occurrence state in the TTT period (jTTT) in the low priority component carrier is reduced. Since the MR is sent only when it is more certain that the quality of the low-priority component carrier has changed, unnecessary MR transmission can be suppressed, and the power consumption of the terminal can be reduced and the radio resources can be reduced. Can be effectively utilized.

The low-priority component carrier enters the waiting state if it maintains the event occurrence state for the jTTT period. When the terminal 150 maintains the event occurrence state for the TTT period with the high priority component carrier, the terminal 150 creates an MR and transmits it to the base station. Further, in the high priority component carrier, when the event occurrence state is maintained for the TTT period, if there is already a low priority component carrier in a waiting state, the MR of the high priority component carrier and the low priority The component carrier MRs are collectively transmitted as one MR to the base station.

In the case of starting a TTT in a low priority component carrier after starting a TTT in a high priority component carrier, if an event occurs in a low priority component carrier, the value of the TTT is the same as above. Is set to jTTT. Other operations are also the same as described above, and thus description thereof is omitted.

As described above, in the present embodiment, the TTT period in the low-priority component carrier is made longer than the TTT period in the high-priority component carrier, thereby making it more than the first embodiment described above. Unnecessary because the number of MRs including the quality of the low-priority component carrier is reduced and the MR is sent only when it is more certain that the quality of the low-priority component carrier has changed. MR transmission can be suppressed, power consumption of the terminal can be reduced, and radio resources can be effectively used.

(Sixth embodiment)
A radio communication system according to the sixth embodiment of the present invention will be described with reference to FIGS. The radio communication system according to the sixth embodiment of the present invention includes a terminal 160 and a base station (not shown).

FIG. 20 is a block diagram showing a configuration of terminal 160 of the present embodiment. In the radio communication system according to the present embodiment, terminal 160 receives a reference signal transmitted from the base station for each cell in the downlink, and uses the measurement result derived based on a predetermined calculation formula as MR. It has a function to report to the base station on the uplink. Further, the base station allocates and manages radio resources (for example, frequency bands in the frequency domain and time domain), and needs to be handed over to another cell based on the MR reported from the terminal 160. In the case of determination, it has a function of performing a handover process, and has a role of an access point of a radio access network for the terminal 160.

[Configuration of terminal 160]
With reference to FIG. 20, the structure of the terminal 160 in 6th Embodiment is demonstrated. The difference between the terminal 160 and the terminal 110 of the first embodiment is the configuration of the measurement result report control unit 162. Therefore, in the terminal 160 of this Embodiment, the same reference number is attached | subjected about the component same as the component of the terminal 110 of 1st Embodiment, and the detailed description is abbreviate | omitted.

The terminal 160 includes a reception unit 111, a measurement result report control unit 162, a control unit 113, and a transmission unit 114.

The measurement result report control unit 162 has a function of controlling the measurement of the reference signal based on the component carrier information and the measurement setting input from the control unit 113. The measurement result report control unit 162 has a function of instructing the reception unit 111 to measure the reference signal. The component carrier information includes information indicating whether the component carrier has a high priority or a low priority, position information of a reference signal, and the like. The measurement result report control unit 162 includes a measurement result report determination unit 1621, a carrier priority determination unit 1622, and a measurement result report creation unit 1623. The carrier priority determination unit 1622 has the same function as the carrier priority determination unit 1122 of the first embodiment.

The measurement result report determination unit 1621 has the following functions in addition to the function of the measurement result report determination unit 1121. If the high priority component carrier maintains the event occurrence state for the TTT, the high priority component carrier expires the TTT. At that time, if there is a high-priority component carrier that has started TTT but has not yet expired, measurement result report determination unit 1621 has started TTT but has not yet expired TTT. Shorten the TTT of the high priority component carrier and stop. The measurement result report determination unit 1621 outputs the measurement result of the high-priority component carrier that has expired TTT and the measurement result of the high-priority component carrier that has stopped TTT to the measurement result report creation unit 1623. If there is a component carrier in a waiting state at this time, the measurement result of the component carrier is also output to the measurement result report creation unit 1623 together. Note that there may be a plurality of high priority component carriers that have expired TTT.

Note that the measurement result report determination unit 1623 adds information indicating that TTT has expired to the measurement result of the component carrier that has maintained the event occurrence state for the period of TTT, or adds TTT to the measurement result of the component carrier that has stopped TTT. The information indicating that the TTT has expired is added to the measurement result of the component carrier that has expired the TTT, and the information that the TTT has been terminated is added to the measurement result of the component carrier that has stopped the TTT. , A function of outputting to the measurement result report creation unit 1623 may be provided.

Also, the measurement result report determination unit 1621 may have a function of outputting the component carrier measurement result to the measurement result report creation unit 1623 by distinguishing each event. In this case, when TTT expires for a certain high priority component carrier, if there is another high priority component carrier that has started TTT in the same event, the measurement result of that component carrier is also measured. The result is output to the result report creation unit 1623. Similarly, the waiting component carriers may be output to the measurement result report creation unit 1623 together if there are waiting component carriers whose TTT has expired in the same event.

The measurement result report creation unit 1623 creates one MR based on the component carrier measurement result output from the measurement result report determination unit 1621 and outputs the MR to the transmission unit 114. Note that the measurement result report creation unit 1623 may have a function of creating a measurement result report for each event. In this way, MR can be created for each event, and items related to different events are not combined into one MR, so the MR format is simplified. In addition, since information on different events is not included, useless resource consumption can be eliminated. Also, since the information required by the base station differs for each event, dividing the MR for each event is effective for the base station to organize the information.

FIG. 21 is a diagram for explaining a method of reporting a measurement result in the terminal 160 according to the sixth embodiment. FIG. 21 shows an example in which an event occurs in the high-priority component carrier 2 and an event occurs in the high-priority component carrier 1 and TTT starts after the TTT starts. In this case, the terminal 160 maintains the event occurrence state for the high-priority component carrier 2 for TTT, and when the TTT expires, the measurement result of the high-priority component carrier 2 and the high-priority component at that time One MR including the measurement result of carrier 1 is created and sent to the base station.

By doing in this way, the terminal 160 can send the MR including the measurement result of the high priority component carrier all at once without repeatedly sending, so the base station can easily determine the handover. Can be done. Also, by including the measurement result of the high priority component carrier that was scheduled to be sent later in the report of the measurement result of the component carrier previously started by the TTT, the base station can move the terminal 160 to a more appropriate cell. Handover can be performed quickly.

[Operation of communication system]
FIG. 22 is a flowchart for explaining the operation of the radio communication system according to the sixth embodiment. With reference to FIG. 22, the operation of the wireless communication system of the present embodiment will be described.

The terminal 160 measures the reference signal for each component carrier based on the measurement setting or taking into account other information (for example, component carrier information used for carrier aggregation) (step S601). Subsequently, the terminal 160 derives a measurement result for each component carrier based on a calculation formula determined from the measured reference signal (step S602). Next, for each component carrier, the terminal 160 determines whether or not the measurement result satisfies an event criterion determined based on the measurement setting (event determination) (step S603). In addition, when the reference signal is measured for each component carrier by adding other information to the measurement setting, if the measurement target (MeasObject) of the component carrier is not defined in the measurement setting, the terminal 160 newly measures. The target may be generated or used by changing a part of the measurement target specified in the measurement setting (for example, changing the carrier frequency to the carrier frequency of the component carrier used for carrier aggregation). Good.

If the measurement result satisfies the event criteria determined based on the measurement setting (YES in step S603), the terminal 160 enters an event generation state, starts TTT on the component carrier, and continues event determination (step S604). ). When the measurement result does not satisfy the event criteria determined based on the measurement setting (NO in step S603), the process returns to step S601 and the reference signal is measured again for each component carrier.

After starting TTT in step S604, the terminal 160 determines whether or not the component carrier satisfies the event criteria determined based on the measurement settings during the TTT period (step S605). If the event criteria are not met before the end of the TTT period (NO in step S605), the process returns to step S601 and the reference signal is measured again for each component carrier.

When the component carrier maintains the event occurrence state during the TTT (YES in step S605), the terminal 160 determines whether or not the component carrier is a high priority component carrier (step S606). ). Note that which component carrier is a high-priority component carrier and which component carrier is a low-priority component carrier is referred to the control information sent from the base station or the terminal 160 in advance. It is determined by the method of calculating the high priority component carrier that is held. Examples of high priority component carriers are as described above.

If the component carrier that has maintained the event occurrence state during the TTT is a high-priority component carrier (YES in step S606), the terminal 160 determines whether TTT has been started in another high-priority component carrier. Is determined (step S607).

When it is determined in step S607 that TTT has been started in another high priority component carrier, TTT has been started in another high priority component carrier (YES in step S607). The terminal 160 shortens the TTT of the high-priority component carrier that has started TTT and stops (step S608). In step S608, the terminal 160 shortens the TTT of the high-priority component carrier that has started the TTT and, when stopped, determines whether there is a waiting component carrier in the low-priority component carrier. (Step S609).

If it is determined in step S609 that there is a waiting component carrier in the low priority component carrier, if there is a waiting low priority component carrier (YES in step S609), the terminal 160 Create MR including the measurement results of the low-priority component carriers in the waiting state, the measurement results of the high-priority component carriers that have expired TTT, and the measurement results of the high-priority component carriers that have stopped TTT Then, MR is transmitted to the base station (step S610).

By doing in this way, if the terminal 160 has started TTT in another high-priority component carrier at the timing of sending the MR of a certain high-priority component carrier, the other high-priority component carrier The component carrier measurement results are also sent to the base station in one MR, and if there is a low priority component carrier in the waiting state, the measurement results of the low priority component carrier are also combined in one MR. Can be sent to the base station. As a result, the base station can grasp the radio wave condition of the high priority component carrier and the radio wave condition of the low priority component carrier with one MR, so that the base station easily performs mobility control of the terminal 160. In addition, the data throughput of the terminal 160 can be improved.

In addition, when the terminal 160 starts TTT with another high priority component carrier in step S607 (YES in step 607), when there is no waiting component carrier (NO in step S609), An MR including the measurement result of the high-priority component carrier that has expired TTT and the measurement result of the high-priority component carrier that has stopped TTT is created, and the MR is transmitted to the base station (step S610). In this way, when there is no low-priority component carrier that already satisfies the TTT period event criterion, the terminal 160 can determine the TTT period event criterion in one cell of the high-priority component carrier. If the condition is satisfied, the MR including the measurement result of the high priority component carrier can be transmitted to the base station, and the base station can perform the mobility control of the terminal 160 simply and quickly.

If it is determined in step S607 that TTT is started in another high priority component carrier, TTT is not started in another high priority component carrier (NO in step S607). The terminal 160 determines whether there is a waiting component carrier in the low priority component carriers (step S612).

If it is determined in step S612 that there is a low-priority component carrier and there is a waiting component carrier (YES in step S612), the terminal 160 An MR is created including the measurement result of the low-priority component carrier in the waiting state and the measurement result of the high-priority component carrier that has expired TTT, and the MR is transmitted to the base station (step S613). By doing in this way, if the terminal 160 has not started the TTT at another high-priority component carrier at the timing of sending the MR of the high-priority component carrier, the high-priority component that has expired the TTT. The measurement result of the component carrier and the measurement result of the component carrier in the waiting state can be sent to the base station. As a result, the base station can grasp the radio wave conditions of the high-priority component carrier and the low-priority component carrier with one MR, so that the mobility control of the terminal 160 can be easily performed, The data throughput of the terminal 160 can be improved.

In addition, when the terminal 160 has not started TTT with another high priority component carrier in step S607 (NO in step 607), when there is no waiting component carrier (NO in step S612), An MR including the measurement result of the high-priority component carrier whose TTT period has expired is created, and the MR is transmitted to the base station (step S614). In this way, when there is no low-priority component carrier that already satisfies the TTT period event criterion, the terminal 160 satisfies the TTT period event criterion in the high-priority component carrier. The MR including the measurement result of the high priority component carrier can be transmitted to the base station, and the base station can perform the mobility control of the terminal 160 simply and quickly.

When the component carrier determined to maintain the TTT period event occurrence state in step S605 is a low priority component carrier (NO in step S606), the terminal 160 determines the TTT period in the high priority component carrier. A wait state is entered until the event occurrence state is maintained (step S615). By doing so, since it is not time to send MR in the high priority component carrier that is a reference for handover, MR of the low priority component carrier is not sent, so that useless transmission of MR can be reduced, In addition to reducing the use of radio resources, the number of times the terminal 160 sends MR can be reduced, and the power consumption of the terminal 160 can be suppressed.

As described above, according to the radio communication system of the present embodiment, when there are a plurality of high priority component carriers that have started TTT, the TTT is set to the timing at which TTT is completed earliest. Since the measurement results of other high-priority component carriers that have been started are included in one MR and sent to the base station, the base station can easily control the mobility of the terminal and improve the data throughput of the terminal can do. Further, by suspending the measurement result report of the low priority component carrier, it is possible to reduce useless use of radio resources and to suppress the power consumption of the terminal.

In the present embodiment, although an embodiment in which a high priority component carrier and a low priority component carrier are mixed is shown, the present invention is a case where only a high priority component carrier exists, that is, It can also be applied when there is no priority between carriers. In this case, the terminal can omit the functions of determining the priority of the component carrier and searching for a waiting carrier. That is, step S606, step S615, step S609, and step S612 can be omitted.

In the present embodiment, the TTT of another high priority component carrier has started at the timing when the TTT expires for a certain high priority component carrier and the measurement result is reported, but the TTT has still expired. When the TTT of the other high priority component carrier has not expired, the measurement of the other high priority component carrier is stopped and the measurement result is transmitted to the base station. However, in this case, at the timing when the TTT of the high-priority component carrier whose TTT has started first expires, the period in which the event priority is satisfied in the high-priority component carrier whose TTT has started later is a predetermined period. If it is shorter, the measurement result of the high-priority component carrier started by TTT after that TTT may not be reported together with the measurement result of the high priority component carrier expired and started. In this way, only more reliable information can be reported to the base station.

(Modification)
The embodiments of the present invention have been described above by way of example, but the scope of the present invention is not limited to these embodiments, and can be changed or modified according to the purpose within the scope of the claims. is there.

For example, although the first to sixth embodiments have been described separately in the above description, the scope of the present invention is not limited to this, and these embodiments can be used in combination with each other. It is.

For example, when the second embodiment and the third embodiment are combined, when the quality between component carriers in the second embodiment is similar, that is, the same type measurement result report determination unit 1222 has a third The TTT value of the high priority component carrier may be shortened by combining the embodiments. Further, both when the quality between component carriers in the second embodiment is similar and when the quality between component carriers is different, that is, the same type measurement result report determination unit 1222 and the different type measurement result report determination unit 1223, The TTT value of the high priority component carrier may be shortened by combining the third embodiment.

Also, for example, when combining the second embodiment and the fifth embodiment, both when the quality between component carriers in the second embodiment is similar and when the quality between component carriers is different, That is, the same measurement result report determination unit 1222 and the heterogeneous measurement result report determination unit 1223 may be combined with the fifth embodiment to increase the TTT value of the low priority component carrier.

Also, for example, when the second embodiment, the third embodiment, and the fifth embodiment are combined, the quality between component carriers in the second embodiment is similar, that is, the same kind of measurement result Combining the third embodiment with the report determination unit 1222 to shorten the TTT value of the high priority component carrier, and the case where the quality between the component carriers in the second embodiment is similar to the component carrier When the quality is different, that is, the same measurement result report determination unit 1222 and the heterogeneous measurement result report determination unit 1223 are combined with the fifth embodiment to increase the TTT value of the low priority component carrier. May be.

Further, for example, when the sixth embodiment is combined with the second embodiment, the second step is performed instead of step S614 as the next step after selecting NO in step S606 of the sixth embodiment. Step S212 and subsequent steps of the form may be applied. Further, by applying step S601 and subsequent steps of the sixth embodiment modified as described above instead of the following step and subsequent steps in which YES is selected in step S201 of the second embodiment, the second embodiment Also in the form, it is possible to apply operations between component carriers with high priority. By doing in this way, MR including only the measurement result of the low priority component carrier can be transmitted to the base station.

In the above embodiment, an example is shown in which there is one high-priority component carrier and one or more low-priority component carriers. However, when there are multiple high-priority component carriers. Also, the present invention can be applied. When a plurality of high-priority component carriers are used, MR is transmitted every time an event occurrence state is maintained for a period of TTT with high-priority component carriers. That is, even if the TTT is started in another high-priority component carrier when the event occurrence state is maintained for the TTT period in the high-priority component carrier, the terminal may have another high-priority component carrier. The MR is transmitted without waiting for the component carrier to maintain the event occurrence state during the TTT period.

In the third embodiment and the fourth embodiment, the method of shortening the TTT of the high-priority component carrier is shown. However, instead of shortening the TTT, the high-priority component carrier is used. A method of increasing the hysteresis may be used. By doing so, in the high priority component carrier, it becomes easy to maintain the event occurrence state during the TTT period, so the probability of sending MR increases. As a result, the probability that a handover decision will be made quickly increases.

In the fifth embodiment, the method of increasing the TTT in the low-priority component carrier has been described. However, instead of increasing the TTT, the hysteresis value is decreased for the low-priority component carrier. A method may be used. In this way, in the low priority component carrier, it becomes difficult to maintain the event occurrence state during the TTT period, so only when it is more certain that the situation has changed in the low priority component carrier, Since MR is sent, useless MR can be reduced.

In the above embodiment, a method of changing the operation for each event may be used. For example, when comparing the serving cell and the neighbor cell and when comparing with the threshold value, when changing the operation and comparing the serving cell and the neighbor cell, when applying the present invention and comparing with the threshold value, The present invention may not be applied. The reason why the present invention is not applied when comparing with the threshold value is that the base station may always need the information when comparing with the threshold value.

In the above embodiment, the operation may be changed depending on whether the measurement result included in the MR is RSRP or RSRQ. For example, when carrier aggregation is performed in the same frequency band (for example, 800 MHz band), when MR includes RSRP, it is determined that the quality difference between component carriers is similar. On the other hand, when MR includes RSRQ, it is determined that the difference in quality between component carriers is different. Therefore, when RSRP is included, an operation when the quality is similar between component carriers may be performed, and when RSRQ is included, an operation when the quality is different between component carriers may be performed.

In the above embodiment, when the predetermined condition described above is satisfied, the terminal transmits the measurement result of the high priority component carrier and the measurement result of the low priority component carrier together to the base station. To do. Specifically, one MR including the measurement result of the high priority component carrier and the measurement result of the low priority component carrier may be created and sent to the base station, or the high priority component carrier The MR including the measurement result and the MR including the measurement result of the low-priority component carrier may be separately created and the MRs may be sent together. Here, one MR example including the measurement result of the high priority component carrier and the measurement result of the low priority component carrier is shown in FIG. 8, but the measurement result of the high priority component carrier and the low priority are shown. There are several other methods for creating one MR that includes the measurement results of the component carriers of the degree.

The first example will be described with reference to FIG. FIG. 23 shows an example in which measurement results of measurements having different measurement identifiers (MeasID) are collected. The format part is provided at the very beginning. Conventionally, the base station has determined the measurement identifier in this part, but MRs of different formats can be sent by indicating the format with a value not assigned by the measurement identifier here. Immediately after that, indicate how many measurement identifiers the measurement results are included. Next, the value of the measurement identifier is entered and described in the conventional MR format. When the measurement result for one measurement identifier has been described, the value of the measurement identifier is entered and described in the conventional MR format. By repeating this, measurement results of a plurality of measurement identifiers can be included in one MR.

In the second example, when the serving cell is the same in the plurality of measurement identifiers in the first example, the reference signal reception power of the serving cell (RSRP of the serving cell) is used for the measurement result parts of the second and subsequent measurement identifiers. ) And the reference signal reception quality (serving cell RSRQ) of the serving cell.

The third example is a format in which the TTT is shortened or the TTT is lengthened is included in the MR. This will be described with reference to FIG. 23, the TTT of the high priority component carrier is lengthened, the TTT of the low priority component carrier is shortened, or the TTT of the high priority component carrier is lengthened to reduce the low priority component. A value including the meaning of shortening the carrier TTT is entered. This is because the base station can grasp what the high priority component carrier and the low priority component carrier of the terminal are. At this time, if there is a margin in the format value, the format value is changed depending on whether the measurement result of the different measurement identifier is included or not. Use the format without the number of the next measurement identifier (Number of MeasID).

A fourth example is a method including shortening the TTT value for a specific cell in a high priority component carrier. This will be described with reference to FIG. In the part of the format of FIG. 23, a value including the meaning that the TTT value of a specific cell is lengthened is entered. Thereafter, unlike FIG. 23, the number of target cells is entered in the next part, and the cell ID of the target cell is included in the next part. If there are multiple cells, list them. However, when only one specific cell is determined, it is only necessary to provide the cell ID part of the target cell after the format. After that, the format shown in FIG. 23 may be used, or another format may be used.

The fifth example is an example in which the first format (Frormat) portion is omitted in the first to fourth examples. This can be omitted if the format can be distinguished by the base station determining whether the terminal is performing carrier aggregation.

In addition, you may apply a base station to what accommodates terminals, such as a relay node (Relay Node) and a home eNB (Home eNB). Moreover, you may apply a terminal to what connects to base stations, such as a relay node. Further, the present invention may be applied only to a specific event or may be applied to all events.

In the case where the present invention is applied only to a specific event, when a TTT for event 1 is satisfied in a component carrier in which a specific event (event 1) is set, a specific event different from event 1 If one or more component carriers for which (Event 2) is set have started TTT for event 2, start TTT for event 2 in addition to the measurement result of the component carrier that satisfies TTT for event 1 A measurement result report including the measurement result of the component carrier that is being used may be created and reported. Here, one or both of the event 1 and the event 2 set as specific events may be a plurality of events. Further, event 1 and event 2 set as specific events may overlap. Event 1 and event 2 set as specific events may be set in the terminal in advance, or may be notified to the terminal when the measurement setting is performed from the base station.

In the sixth embodiment, the measurement result report determination unit 1623 adds the information that the TTT has not expired to the measurement result of the component carrier that has started the TTT but has not expired. Although it has been explained that it may have a function of outputting to the result report creating unit 1623, in the third to fifth embodiments, when the TTT is shortened or extended, the measurement result is similarly obtained. Information indicating that the TTT has been shortened or the TTT has been extended may be added to the report.

When there are a plurality of frequency measurement settings in one event, one MR may be sent for each event by applying the first to sixth embodiments for each event. By doing in this way, since the events set for different purposes are not put together in one MR, the base station can accurately acquire information that matches the purpose.

When there is no measurement setting for multiple frequencies in one event, the measurement results of multiple events are combined into one MR by applying the first to sixth embodiments across multiple events. You may send it. By doing in this way, in the measurement setting, since it is possible to combine things set in different events into one MR, the base station can easily make a handover decision.

Although the presently preferred embodiments of the present invention have been described above, various modifications can be made to the present embodiments, and such modifications are within the true spirit and scope of the present invention. It is intended that the appended claims include all modifications.

As described above, the terminal according to the present invention reports the necessary measurement results to the base station in consideration of the priority of the component carrier used by the terminal, so that the base station performs the mobility control of the terminal. It can be performed easily and has the effect of improving the data throughput of the terminal, and by means of carrier aggregation, it can communicate with each component carrier of a plurality of cells at the same time, especially in the radio wave condition. It is useful as a terminal for measuring and reporting to a base station.

110 terminal 112 measurement result report control unit 1121 measurement result report determination unit 1122 carrier priority determination unit 1123 measurement result report creation unit 210 base station 212 handover determination processing unit 120 terminal 1221 inter-carrier quality determination unit 1222 homogeneous measurement result report determination unit 1223 Heterogeneous measurement result report determination unit 220 base station 222 handover determination processing unit 130 terminal 1324 TTT shortening unit 140 terminal 1424 base station-specific TTT shortening unit 1432 base station subordinate cell list management unit 240 base station 2431 base station subordinate cell list management unit 150 terminal 1524 Low-priority TTT extension unit 160 Terminal 162 Measurement result control unit 1621 Measurement result report determination unit 1622 Carrier priority determination unit 1623 Measurement result report generation unit

Claims

A wireless communication terminal capable of communicating with a wireless communication base station by simultaneously using each component carrier of a plurality of communication cells by carrier aggregation,
A measurement result report determination unit that determines whether the measurement result of the radio wave condition of the component carrier satisfies a predetermined event criterion for triggering the measurement result report;
A carrier priority determination unit that determines whether the component carrier related to the determination of the measurement result is a high priority component carrier or a low priority component carrier;
When the measurement result of the component carrier determined to be low priority by the carrier priority determination unit satisfies the event criteria continuously for a predetermined trigger period, the measurement result of the low priority component carrier When the component carrier measurement result determined to be high priority by the carrier priority determination unit satisfies the event criteria continuously for a predetermined trigger period, When there is a report of the measurement result of the priority component carrier, the measurement result of the low priority component carrier in the waiting state is reported to the radio communication base station together with the measurement result of the high priority component carrier. A measurement result report control unit for reporting,
A wireless communication terminal comprising:
The measurement result report control unit, when the measurement result of the component carrier determined to be high priority by the carrier priority determination unit satisfies the event criteria continuously for a predetermined trigger period, the waiting state 2. When there is no report on the measurement result of the low-priority component carrier, the measurement result of the high-priority component carrier is independently reported to the radio communication base station. The wireless communication terminal described.
When the measurement result report control unit reports the measurement result of the low-priority component carrier in the waiting state together with the measurement result of the high-priority component carrier, the measurement result report of the high-priority component carrier The wireless communication terminal according to claim 1, wherein one measurement result report including the measurement result of the low priority component carrier in the waiting state is created.
The measurement result report control unit
Only when the quality among a plurality of component carriers is the same, the measurement result of the component carrier determined to be low priority by the carrier priority determination unit continuously satisfies the event criteria for a predetermined trigger period. When waiting, report the measurement result of the low priority component carrier.
When the quality among a plurality of component carriers is different, when the measurement result of the component carrier determined to be low priority by the carrier priority determination unit continuously satisfies the event criteria for a predetermined trigger period If the measurement result of the high-priority component carrier does not meet the event criteria, the measurement result of the high-priority component carrier continues for a predetermined period and does not wait until the event criteria are met. The wireless communication terminal according to claim 1, wherein the measurement result of the priority component carrier is reported.
The wireless communication terminal according to claim 4, further comprising an inter-carrier quality determination unit that determines whether the quality among a plurality of component carriers is the same or different.
Component carrier measurement result determined to be low priority by the carrier priority determination unit satisfies event criteria, and component carrier measurement result determined to be high priority by the carrier priority determination unit 6. The wireless communication according to claim 1, further comprising: a trigger period shortening unit that shortens the trigger period of the high-priority component carrier when an event criterion is satisfied. Terminal.
The trigger period shortening unit is after an event has occurred in a component carrier determined to be low priority by the carrier priority determination unit, and when the event has not passed the trigger period, The trigger period of the high priority component carrier is shortened when an event occurs in the component carrier determined to be high priority by the carrier priority determination unit. Wireless communication terminal.
The trigger period shortening unit generates the carrier priority when an event has occurred in a component carrier determined to be high priority by the carrier priority determination unit, but the event has not passed the trigger period. The wireless communication according to claim 6, wherein when an event occurs in a component carrier determined to be low priority by a degree determination unit, the trigger period of the high priority component carrier is shortened. Terminal.
When the trigger period after the shortening of the high-priority component carrier has already passed at the time when the event occurs in the low-priority component carrier, the trigger period shortening unit 9. The wireless communication terminal according to claim 8, wherein the measurement result of the carrier is reported immediately.
The trigger period shortening unit only applies the high priority when the low priority component carrier in which the event has occurred and the high priority component carrier in which the event has occurred are the same component carrier of the radio communication base station. If the component carrier of the radio communication base station is different from the low priority component carrier in which the event occurred and the high priority component carrier in which the event occurred The wireless communication terminal according to claim 6, wherein the trigger period of the high priority component carrier is not shortened.
The measurement result of the component carrier determined to be the low priority by the carrier priority determination unit satisfies the event criterion, and the component carrier determined to be the high priority reference by the carrier priority determination unit. The trigger period extension unit for extending the trigger period of the low priority component carrier when the measurement result satisfies an event criterion, according to any one of claims 1 to 5. Wireless communication terminal.
The measurement result report control unit, when the measurement result of the first component carrier determined to be high priority by the carrier priority determination unit continuously meets the event criteria for a predetermined trigger period, When the measurement result of the second component carrier determined to be high priority by the carrier priority determination unit has not yet continued for a predetermined trigger period after occurrence of a state satisfying the event criterion, the second component carrier The measurement result of the second component carrier is reported together with the measurement result of the first component carrier without waiting for the measurement result of the component carrier of the first component carrier to satisfy the event criteria continuously for a predetermined trigger period. The wireless communication terminal according to claim 1, wherein the wireless communication terminal is a wireless communication terminal.
The measurement result report control unit reports, together with the measurement result of the second component carrier, that the measurement result of the second component carrier does not satisfy the event criteria continuously for a predetermined trigger period. The wireless communication terminal according to claim 12.
An anchor carrier that manages a connection with a radio communication base station is the high-priority component carrier, a component carrier other than the anchor carrier is the low-priority component carrier, or
A backward compatible component carrier as the high priority component carrier, and a component carrier other than the backward compatible component carrier as the low priority component carrier, or
The component carrier that is transmitting PDCCH is the high-priority component carrier, the component carrier that is not transmitting PDCCH is the low-priority component carrier, or
Based on the frequency priority broadcast from the radio communication base station, set a high priority component carrier and a low priority component carrier, or
A component that does not transmit a PDCCH using an anchor carrier that manages a connection with a radio communication base station as the high-priority component carrier, a carrier that transmits a PDCCH other than the anchor carrier as a low-priority component carrier The wireless communication terminal according to claim 1, wherein no measurement is performed on a carrier.
A method for reporting a measurement result of a radio wave condition in a wireless communication terminal capable of communicating with a wireless communication base station by simultaneously using component carriers of a plurality of communication cells by carrier aggregation,
For each of the plurality of component carriers, a measurement step for obtaining a measurement result from a reference signal indicating their radio wave status;
A measurement result report determining step for determining whether or not each of the measurement results satisfies a predetermined event criterion for triggering the measurement result report;
A carrier priority determination step of determining whether a component carrier related to determination of the measurement result is a high priority component carrier or a low priority component carrier; and
When the measurement result of the component carrier determined to be low priority by the determination of the carrier priority determination step satisfies the event criteria continuously for a predetermined trigger period, measurement of the low priority component carrier A report waiting step for waiting for a result report;
When the measurement result of the component carrier determined to be high priority by the determination of the carrier priority determination step satisfies the event criterion continuously for a predetermined trigger period, the low priority component in the waiting state A waiting state determination step for determining whether there is a report of a measurement result of the carrier;
In the waiting state determination step, when it is determined that there is a report of the measurement result of the low priority component carrier in the waiting state, the measurement result of the high priority component carrier to the radio communication base station A measurement result merge report step for reporting the measurement result of the low-priority component carrier in the waiting state together with the report of
In the waiting state determination step, if it is determined that there is no report of the measurement result of the low priority component carrier in the waiting state, the measurement result of the high priority component carrier to the radio communication base station A single measurement result reporting step for reporting
A method for reporting measurement results of radio wave conditions, characterized by comprising:
A wireless communication base station capable of providing communication by carrier aggregation using simultaneously each component carrier of a plurality of communication cells to a wireless communication terminal,
A receiver for receiving a report of the measurement results of the radio quality of the component carrier from the wireless communication terminal;
When receiving the measurement result of the low-priority component carrier together with the measurement result of the high-priority component carrier at the receiving unit, giving priority to the measurement result of the high-priority component carrier, A handover determination processing unit for determining a handover in consideration of the measurement result of the priority component carrier;
A wireless communication base station comprising:
A wireless communication system comprising a wireless communication base station and a wireless communication terminal, wherein the wireless communication base station and the wireless communication terminal communicate with each other using component carriers of a plurality of communication cells simultaneously by carrier aggregation. Is possible,
The wireless communication terminal is
A measurement result report determination unit that determines whether the measurement result of the radio wave condition of the component carrier satisfies a predetermined event criterion for triggering the measurement result report;
A carrier priority determination unit that determines whether the component carrier related to the determination of the measurement result is a high priority component carrier or a low priority component carrier;
When the measurement result of the component carrier determined to be low priority by the carrier priority determination unit satisfies the event criteria continuously for a predetermined trigger period, the measurement result of the low priority component carrier When the component carrier measurement result determined to be high priority by the carrier priority determination unit satisfies the event criteria continuously for a predetermined trigger period, When there is a report of the measurement result of the priority component carrier, the measurement result of the low-priority component carrier in the waiting state is reported to the radio communication base station together with the measurement result of the high-priority component carrier. A measurement result report control unit for transmitting a report,
The wireless communication base station is
A receiving unit for receiving a measurement result report transmitted from the measurement result report control unit;
When receiving the measurement result of the low-priority component carrier together with the measurement result of the high-priority component carrier at the receiving unit, giving priority to the measurement result of the high-priority component carrier, A wireless communication system comprising: a handover determination processing unit configured to determine handover in consideration of a measurement result of a priority component carrier.