JP6850311B2 - Base stations, wireless communication systems and wireless communication methods - Google Patents

Description

The present disclosure relates to base stations, wireless communication systems and wireless communication methods in next-generation mobile communication systems.

In the Universal Mobile Telecommunications System (UMTS) network, Long Term Evolution (LTE) has been specified for the purpose of further high-speed data rate, low latency, etc. (Non-Patent Document 1). In addition, LTE-Advanced (3GPP Rel.10-14) has been specified for the purpose of further increasing the capacity and sophistication of LTE (Third Generation Partnership Project (3GPP) Release (Rel.) 8 and 9).

A successor system to LTE (for example, 5th generation mobile communication system (5G), 5G + (plus), New Radio (NR), 3GPP Rel.15 or later, etc.) is also being studied.

In wireless communication systems such as LTE (for example, 3GPP Rel.10-14) and NR (for example, 3GPP Rel.15 ~), a plurality of component carriers (CC) (also referred to as cells, serving cells, carriers, etc.) Carrier Aggregation (CA) is supported.

3GPP TS 36.300 V8.12.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)”, April 2010

Generally, in CA, since the bandwidth that can be transmitted increases by integrating a plurality of CCs, it is considered to be effective in improving the throughput.

However, under certain conditions (for example, a relatively high traffic environment such as a terminal station or flow line during commuting, a facility for attracting customers such as a stadium or an event venue), the effect of improving throughput by increasing the bandwidth by CA). May not be fully obtained.

Therefore, one of the purposes of the present disclosure is to provide a base station, a wireless communication system, and a wireless communication method capable of optimizing the throughput.

The base station according to one aspect of the present disclosure is assigned to a transmitter that transmits a downlink shared channel in a second cell that is integrated with the first cell by carrier aggregation, and a predetermined frequency domain of the first cell. A receiving unit that receives delivery confirmation information for the downlink shared channel by using the uplink control channel or an uplink shared channel assigned to a frequency domain other than the predetermined frequency domain of the first cell, the first cell, and the uplink shared channel. A control unit that controls switching on or off of the carrier aggregation based on the traffic in at least one of the second cells is provided, and the control unit has the traffic equal to or higher than the first threshold value. Or, if greater than, switch off carrier aggregation, delete the second cell that is integrated with the first cell, and the traffic is greater than or equal to the second threshold, which is greater than or equal to the first threshold, or more. When it is large, the uplink control channel resource allocated for the second cell is released, and the uplink shared channel is allocated to the area where the uplink control channel resource is released .

According to one aspect of the present disclosure, the throughput of the wireless communication system can be optimized.

1A and 1B are diagrams showing an example of a PUCCH region allocated within the bandwidth of a cell. FIG. 2 is a diagram showing an example of a transmission / reception status of downlink data when the PUSCH band is tight. 3A and 3B show an example of the amount of downlink data and the downlink throughput when the PUSCH band is tight. FIG. 4 is a diagram showing an example of the relationship between traffic and throughput in the batch control according to the second aspect. 5A and 5B are conceptual diagrams of collective control according to the second aspect. FIG. 6 is a diagram showing an example of the operation of batch control of CA off according to the second aspect. FIG. 7 is a diagram showing an example of the operation of batch control of CA ON according to the second aspect. FIG. 8 is a diagram showing an example of the relationship between traffic and throughput in the stepwise control according to the second aspect. 9A-9C are conceptual diagrams of stepwise control according to the second aspect. 10A-10D show an example of the configuration within the cell band. FIG. 11 is a diagram showing an example of the operation of the stepwise control of CA off according to the second aspect. FIG. 12 is a diagram showing an example of the operation of the stepwise control of CA ON according to the second aspect. FIG. 13 is a diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. FIG. 14 is a diagram showing an example of the configuration of the base station according to the embodiment. FIG. 15 is a diagram showing an example of the configuration of the user terminal according to the embodiment. FIG. 16 is a diagram showing an example of the hardware configuration of the base station and the user terminal according to the embodiment.

In wireless communication systems such as LTE (for example, 3GPP Rel.10-14) and NR (for example, 3GPP Rel.15 ~), carrier aggregation (Carrier) that aggregates a plurality of component carriers (CC). Aggregation (CA) is supported.

Each CC may be configured with a predetermined bandwidth (eg, up to 20 MHz for LTE). Further, the number of CCs integrated in CA may be, for example, a maximum of 5 CCs or a maximum of 32 CCs in LTE. The bandwidth of each CC and the number of CCs integrated by the CA are not limited to these. Further, CC may be paraphrased as a cell, a serving cell, a carrier, or the like.

In CA, a first (first) cell (for example, a primary cell (P cell), P cell)) and a second (second) cell (for example, a secondary cell (SCell), an S cell). )) And may be integrated. The second cell may be one or more. The plurality of cells integrated by the CA may be configured in the user terminal (User Equipment (UE)) by higher layer signaling (for example, Radio Resource Control (RRC) signaling).

For example, when multiple downlink data are transmitted in each of a plurality of cells integrated by CA, the bandwidth available for transmitting the downlink data is increased, so that the downlink throughput (for example, downlink Medium Access Control (MAC) throughput) is increased. ) Is effective.

By the way, when a plurality of downlink data is transmitted in each of a plurality of cells integrated by the CA, the UE feeds back delivery confirmation information for each of the plurality of downlink data in a specific cell (for example, P cell). May be good. The delivery confirmation information includes, for example, delivery confirmation information in the MAC layer (for example, it may be referred to as Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, A / N, etc.), and Transmission Control Protocol ( TCP) At least one of the delivery confirmation information in the layer, but is not limited to these, and may be any delivery confirmation information in a predetermined layer.

For example, in LTE, the UE receives a downlink shared channel (eg, Physical Downlink Shared Channel (PDSCH)) that transmits downlink data in each of the plurality of cells. The UE sets a plurality of A / N for the PDSCH of each of the plurality of cells to the uplink control channel (for example, Physical Uplink Control Channel (PUCCH)) or the uplink shared channel (for example, Physical) of a specific cell (for example, P cell). It may be transmitted (feedback, report) using Uplink Shared Channel (PUSCH)).

Specifically, when a PUSCH is assigned to the UE at the transmission timing of the plurality of A / Ns (for example, a subframe or a slot after a predetermined period after receiving the PDSCH), the UE sets the PUSCH. The plurality of A / Ns may be transmitted using the method. On the other hand, when the PUSCH is not assigned to the UE at the transmission timing of the plurality of A / Ns, the UE may transmit the plurality of A / Ns by using the PUCCH.

In a cell that feeds back a plurality of A / Ns (for example, P cell), the resource for PUCCH (PUCCH resource) is within the bandwidth of the cell (also referred to as cell bandwidth, system bandwidth, bandwidth, system bandwidth, etc.). It may be assigned to a predetermined frequency region (for example, a region at both ends) (also referred to as a PUCCH region). For example, each PUCCH resource may be composed of one or a plurality of resource blocks (Physical Resource Block (PRB)).

1A and 1B are diagrams showing an example of a PUCCH region allocated within the bandwidth of a cell. FIG. 1A shows an example of a PUCCH region when CA is not applied (off). FIG. 1B shows an example of a PUCCH region when CA is applied (on).

As shown in FIG. 1A, when CA is not applied, the PUCCH region includes a PUCCH resource for channel state information (CSI) of the cell, a PUCCH resource for A / N, and a PUSCH in the cell. At least one of the PUCCH resources for a scheduling request (SR) may be allocated.

Note that each PUCCH resource may be frequency hopping for each predetermined time unit (for example, a slot in a subframe or a predetermined number of symbols). Further, the CSI may include at least one of a channel quality identifier (Channel Quality Indicator (CQI)), a precoding matrix identifier (Precoding Matrix Indicator), and a rank identifier (Rank Indicator (RI)).

Further, in FIG. 1A, a PUSCH for one or a plurality of UEs may be assigned (scheduled) to a frequency domain (one or more PRBs) other than the PUCCH region.

As shown in FIG. 1B, when CA is applied, the PUCCH area is used for A / N for PDSCH transmitted in each of a plurality of cells (here, CC # 1 to # 3) integrated by CA. PUCCH resource may be allocated. Further, as shown in FIG. 1B, at least one of the PUCCH resource for CSI and the PUCCH resource for SR of the cell may be allocated to the PUCCH region.

As shown in FIG. 1B, when CA is applied, the PUCCH resource for A / N increases according to the number of cells to which the PDSCH is transmitted, and as a result, the frequency domain that can be allocated to the PUSCH within the bandwidth of the cell. (Also referred to as PUSCH band, PUSCH area, band, bandwidth, etc.) is reduced as compared with the case where CA is not applied (for example, FIG. 1A).

In this way, when CA (downlink CA, also simply referred to as CA) is applied for downlink, the PUSCH band is tight in the cell (for example, P cell) that feeds back A / N to the PDSCH of each of the plurality of cells. There is a risk of doing. When the PUSCH band is tight, the UE cannot properly feed back the A / N to the PDSCH, and as a result of repeated PDSCH retransmissions, there is a possibility that the effect of improving the downlink throughput by CA cannot be appropriately obtained.

In particular, under certain conditions (for example, a relatively high traffic environment such as a terminal station or flow line during commuting, a facility for attracting customers such as a stadium or an event venue), A / N is fed back due to the tightness of the PUSCH band. There is a risk that the number of UEs that cannot be used (the number of non-response terminals for downlink data) will increase. In this case, the amount of downlink data to be retransmitted increases, and there is a possibility that a state in which new downlink data cannot be transmitted continuously occurs (a queue of downlink data occurs). As a result, in the user's experience, it may be expressed as a communication impossible state (zero throughput).

FIG. 2 is a diagram showing an example of a transmission / reception status of downlink data when the PUSCH band is tight. As shown in FIG. 2, the server transmits downlink data for the UE for the first transmission to a base station (for example, eNodeB (eNB)). The base station transmits the downlink data using the PDSCH of one or more cells.

For example, in FIG. 2, the UE attempts to feed back A / N using the PUSCH or PUCCH of a specific cell (for example, P cell), but due to the tight PUSCH band of the specific cell, A with respect to the PDSCH. / N does not reach the base station.

In this case, the server cannot receive the response signal from the UE, so the same downlink data is retransmitted. The base station transmits PDSCH to the UE for the downlink data resent from the server. However, the A / N for the PDSCH also does not reach the base station. As a result, the downlink data is repeatedly resent, and new downlink data cannot be transmitted.

3A and 3B show an example of the amount of downlink data and the downlink throughput when the PUSCH band is tight. As shown in FIG. 3A, when the number of UEs that do not respond to downlink data increases due to the tightness of the PUSCH band, the ratio of retransmission data to initial transmission data in the total amount of downlink data transmitted from the base station increases.

When the ratio of the retransmission data increases as shown in FIG. 3A, the ratio of the initial transmission data decreases, so that the downlink throughput also decreases as shown in FIG. 3B.

As described above, when the PUSCH bandwidth is tight due to the PUCCH resource for A / N feedback to the PDSCH of each of the plurality of cells integrated by CA, the effect of improving the downlink throughput by expanding the downlink bandwidth is sufficiently obtained. It may not be possible (in addition, it may lead to zero throughput). Further, when the PUSCH band is tight, the PUSCH cannot be allocated quickly, and as a result, the uplink throughput may decrease.

In the area where the traffic is constantly higher than the predetermined threshold value (high traffic area), the case where the base stations are sufficiently arranged and the full band is completed is predominant. In such a high traffic area, it is often difficult to add a new base station on the board, and the potential of the already placed base station (existing station) is maximized to prevent a decrease in throughput. There is a need for a method to do (rescue users with zero throughput).

In order to prevent such a decrease in throughput (at least one of downlink throughput and uplink throughput) due to tight PUSCH bandwidth, it is conceivable to switch CA from on to off. On the other hand, if CA is kept off, the effect of improving throughput by CA may not be effectively obtained.

Therefore, the present inventors can optimize the throughput by monitoring (or estimating) the tightness (or traffic) of the PUSCH band and autonomously switching the CA on or off. I was inspired.

For example, we can switch CA from on to off when a tight PUSCH band is expected (or in the case of high traffic) to extend the PUSCH band and reduce CA-related control signals. The idea was to prevent a decrease in downlink throughput due to non-achievement of A / N with respect to PDSCH by making this possible. In addition, when the PUSCH band is not expected to be tight (or in the case of low traffic), the present inventors switch CA from off to on, and transmit PDSCH in a plurality of cells integrated by CA and CA-related. The idea was to improve the downlink throughput by enabling at least one of the control signal transmissions.

Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. The configurations shown in each embodiment may be applied individually or in combination.

(First aspect)
In the first aspect, an index used for determining whether to switch CA on or off will be described. Switching the CA on or off may be determined based on the tightness of the PUSCH band. For example, "base station traffic" may be used for monitoring (estimating) the tightness of the PUSCH band.

The "base station traffic" may be a cell-by-cell traffic formed by the base station, a traffic of at least one cell formed by the base station, or a specific cell (for example, a P cell). , PUCCH SCell, etc.).

The "base station traffic" may include, for example, at least one parameter (metric, index) of (1) to (4) below.
(1) Data flow rate in the wireless section (2) Data retention in the base station (3) Number of users (4) Device load of the base station

(1) The data flow rate in the radio section may be monitored (estimated) based on one or more parameters. The one or more parameters may include parameters of one or more layers (for example, layer 1 (L1), layer 2 (L2), layer 3 (L3) or more). In addition, the one or more parameters may include parameters of one or more protocols (for example, MAC, Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), RRC, Non-Access Stratum (NAS)).

For example, the parameter of L1 is the number of resource blocks available for PUSCH, the number of packets transmitted by PUSCH (for example, Transport Block (TB)) or the code block (Code Block (CB)). Number), at least one of frequency utilization efficiencies may be included.

Further, the parameter of L2 is at least one of the number of packets of the MAC layer (protocol) (for example, the number of MAC protocol data units (Protocol Data Units (PDUs)) and the number of MAC service data units (Service Data Units (SDUs)). One) may be included. Further, the parameter of L2 may include the number of packets of the RLC layer (protocol) (for example, at least one of the number of RLC PDUs and the number of RLC SDUs). Further, the parameter of L2 may include the number of packets of the PDCP layer (protocol) (for example, at least one of the number of PDCP PDUs and the number of PDCP SDUs).

Further, the parameter of L3 or more may include at least one of the number of RRC messages and the number of NAS messages.

(2) The data retention amount in the base station may be monitored (estimated) based on at least one of the retention data amount and the resource usage number (amount) in the buffer of the base station. The amount of stagnant data in the buffer is the amount of stagnant data on at least one of downlink and uplink, at least one of the number of logical channels in which stagnant data exists on at least one of downlink and uplink, and downlink and uplink. It may be paraphrased as at least one of the number of users (or the number of UEs) in which the retention data exists in at least one of the above. The number of resources used may include at least one of the number of resource blocks (for example, the number of resource blocks allocated to PUSCH) and the number of baseband band resources.

(3) The number of users may be monitored (estimated) based on at least one of the number of UEs in the active state (for example, RRC connected) and the number of UEs in the non-intermittent reception (DRX) state. The number of UEs may be monitored in all cells of the base station or in some cells.

(4) The device load of the base station may be monitored (estimated) based on the usage rate of the central processing unit (CPU) of the base station.

The "base station traffic" including at least one of the above (1) to (4) may be monitored (estimated) at a predetermined cycle.

According to the first aspect, the tightness of the PUSCH band (traffic of the base station) used for determining whether the CA is turned on or off can be appropriately monitored.

(Second aspect)
In the second aspect, the CA on / off switching process according to the tightness of the PUSCH band (for example, the “base station traffic” described in the first aspect) will be described.

For the base station, the CA on / off switching process is as follows: (1) S cell configuration (configure) process (S cell setting process), (2) Cell bandwidth configuration change process (configuration change process). At least one may be included.

(1) The S cell setting process may be a process of deleting or adding one or more cells configured as S cells in the UE. For example, the base station may delete at least one cell set as the S cell in the UE when switching CA off. Specifically, the base station may transmit information about the cell to be deleted (for example, the index of the S cell) to the UE. Further, the UE may change the setting of the S cell based on the information.

On the other hand, the base station may add at least one cell set as the S cell to the UE when switching the CA on. Specifically, the base station may transmit information about the cell to be added (for example, at least one of the S cell index, the physical cell ID, and the carrier frequency) to the UE. Further, the UE may change the setting of the S cell based on the information.

(2) The configuration change process may be a process of expanding or reducing the PUSCH band within each cell bandwidth. For example, when the CA is switched off, the base station may release the PUCCH resource for the S cell (reduce the PUCCH area) to expand the PUSCH band. On the other hand, when the CA is switched on, the base station may allocate the PUCCH resource for the S cell (extend the PUCCH area) to reduce the PUSCH band.

In the second aspect, when the CA is switched off or on, the base station may collectively perform the processes included in the above (1) and (2) (collective control), or may perform the processes in stages. Good (stepwise control).

<Batch control>
In the batch control, switching of CA on or off may be determined based on a predetermined threshold value regarding the tightness of the PUSCH band (for example, the traffic of the base station). For example, the base station may decide to turn off CA if the traffic is above (or greater than) a predetermined threshold. The base station may also decide to turn on CA if the traffic is less than (or less than) a predetermined threshold. The traffic is as described in the first aspect.

≪Judgment operation≫
FIG. 4 is a diagram showing an example of the relationship between traffic and throughput in the batch control according to the second aspect. As shown in FIG. 4, the base station may switch CA off when the traffic of the base station is greater than or equal to a predetermined threshold. On the other hand, the base station may switch CA on when the traffic of the base station is smaller than (or less than) a predetermined threshold value.

As the traffic, at least one of the above parameters (1) to (4) described in the first aspect may be monitored. Further, the traffic may be monitored by the base station itself, or the monitoring result of another device may be notified to the base station. In addition, the traffic may be monitored at a predetermined cycle.

As shown in FIG. 4, a predetermined threshold value may be determined based on throughput. Specifically, the throughput in the case of CA on and in the case of CA off is monitored (estimated), and the throughput in the case of CA off becomes larger (or more) than the throughput in the case of CA on (switching). Point) may be set as a predetermined threshold.

As shown in FIG. 4, the throughput (for example, peak throughput, user throughput) can be maximized by switching the CA on or off autonomously (dynamically) based on the traffic of the base station and a predetermined threshold value. ..

Specifically, when the traffic is above (or greater than) a predetermined threshold (high traffic), the throughput is increased by switching the downlink CA from on to off as compared with the case where the downlink CA is kept on. Can be improved. In the case of high traffic, due to the tight PUSCH bandwidth (for example, FIG. 1B), as described in FIG. 2, the non-delivery of the delivery confirmation information causes a state of zero throughput in which new downlink data cannot be transmitted. As a result, the effect of reducing the downlink throughput due to the tightness of the PUSCH bandwidth by the downlink CA may exceed the effect of improving the downlink throughput due to the expansion of the downlink bandwidth by the downlink CA. On the other hand, by switching to CA off, the tightness of the PUSCH band of each cell can be alleviated (for example, FIG. 1A), so that the delivery confirmation information for the downlink data can reach the base station in each cell, and is based on the delivery confirmation information. As a result of being able to transmit new downlink data, it is possible to rescue users with zero throughput (preventing a decrease in downlink throughput due to tight PUSCH bandwidth due to downlink CA). As a result, the effect of improving the downlink throughput by expanding the downlink bandwidth by the downlink CA can be obtained, so that the throughput can be improved.

On the other hand, when the traffic is smaller than (or less than or equal to) a predetermined threshold value (in the case of low traffic), the throughput can be improved by switching the downlink CA from off to on as compared with the case where the downlink CA is kept off. In the case of low traffic, even if the PUSCH bandwidth is tight (for example, FIG. 1B), it is highly possible that the delivery confirmation information for the downlink data can reach the base station in each cell, so that the delivery confirmation information is based on the delivery confirmation information. As a result of being able to transmit new downlink data, zero-throughput users are unlikely to occur. In this case, the effect of improving the downlink throughput by expanding the downlink bandwidth by the downlink CA can be obtained more than the effect of reducing the downlink throughput due to the tightness of the PUSCH bandwidth by the downlink CA. Therefore, in the case of low traffic, the downlink throughput can be maintained even if the downlink CA is turned on.

≪Batch control operation≫
Next, the detailed operation of the batch control of the CA off and on according to the second aspect will be described.

5A and 5B are conceptual diagrams of collective control according to the second aspect. For example, FIG. 5A shows an example of a CA on and off state. FIG. 5B shows an example of the configuration in the band of the cell in the on state and the off state of the CA.

As shown in FIG. 5A, when the CA is on, the UE may receive PDSCH in P cell and S cell # 0 and # 1, respectively. The UE may transmit the A / N for the PDSCH received in the three cells by using the PUCCH or the PUSCH of the P cell. Further, as shown in FIG. 5B, a PUCCH area for the P cell and a PUCCH area for the S cell (here, S cells # 0 and # 1) may be secured within the bandwidth of the P cell.

On the other hand, in the CA off state, S cells # 0 and # 1 set in the UE are deleted. In this case, the UE may receive the PDSCH only in the P cell. The UE may transmit an A / N for a PDSCH received in one cell using the PUCCH or PUSCH of the P cell. Further, as shown in FIG. 5B, the PUCCH area for the S cell may not be secured and the PUCCH area for the P cell may be secured within the bandwidth of the P cell.

FIG. 6 is a diagram showing an example of the operation of batch control of CA off according to the second aspect. In FIG. 6, for example, as shown in FIG. 5A, it is assumed that the base station communicates with the UE using the CAs of the P cell and the S cells # 0 and # 1. The UE in FIG. 6 may be at least one UE (for example, all UEs) that communicates with the base station.

In step S101, the base station monitors traffic at predetermined intervals. In step S102, the base station determines whether the monitored traffic is greater than or equal to a predetermined threshold. When the traffic is smaller than the predetermined threshold value (step S102; NO), this operation returns to step S101. Although not shown, in step S102, it may be determined whether or not the monitored traffic is larger than a predetermined threshold value. As the traffic, at least one parameter described in the first aspect may be monitored.

When the traffic is equal to or higher than a predetermined threshold value (step S102; YES), in step S103, the base station deletes the S cell integrated with the P cell by CA. Specifically, the base station transmits information about the cell to be deleted from the S cell setting (for example, the S cell index) to the UE. Information about the cell to be deleted may be included, for example, in an RRC re-configuration message.

In step S104, the UE may send a response message to the base station when the S cell is deleted based on the information received from the base station. The response message may be, for example, an RRC reset completion message.

In step S105, the base station may extend the PUSCH band of the P cell based on the response message from the UE. Specifically, as shown in FIG. 5B, the base station may release the PUCCH area for the S cell secured within the bandwidth of the P cell and allocate the PUCCH area for the S cell to the PUSCH. Good.

Further, the base station may stop the scheduling of the S cell. By stopping the scheduling of the PDSCH in the S cell, the uplink control information (UCI) (for example, A / N for the PDSCH transmitted in the S cell) superimposed on the PUSCH in FIG. 5B can be reduced.

In this way, by collectively deleting the S cell and expanding the PUSCH band by releasing the PUCCH area for the S cell, as shown in FIG. 4, the throughput due to the tight PUSCH band under high traffic is increased. The decrease can be suppressed quickly.

FIG. 7 is a diagram showing an example of the operation of batch control of CA ON according to the second aspect. Note that FIG. 7 mainly describes the differences from FIG. Step S201 of FIG. 7 is the same as step S101 of FIG.

In step S202, the base station determines whether the monitored traffic is greater than or equal to a predetermined threshold. When the traffic is equal to or higher than a predetermined threshold value (step S202; YES), this operation returns to step S201. Although not shown, in step S202, it may be determined whether or not the monitored traffic is larger than a predetermined threshold value.

If the traffic is less than a predetermined threshold (step S202; NO), in step S203, the base station may reduce the PUSCH band of the P cell. Specifically, as shown in FIG. 5B, the base station may secure a PUCCH area for the S cell within the bandwidth of the P cell, and the PUCCH area for the S cell may not be allocated to the PUSCH.

In step S204, the base station adds an S cell that is integrated with the P cell by CA. Specifically, the base station transmits information about the cell to be added to the S cell setting (for example, the S cell index) to the UE. Information about the cell to be added may be included, for example, in the RRC reset message.

In step S205, the UE may send a response message to the base station by adding an S cell based on the information received from the base station. The response message may be, for example, an RRC reset completion message.

In step S206, the base station may start scheduling the S cell. By starting the PDSCH scheduling in the S cell, for example, the A / N for the PDSCH transmitted in the S cell is multiplexed and transmitted to the PUCCH or PUSCH allocated to the PUCCH area for the S cell shown in FIG. 5B. To. The order of steps S203 and S204 and S205 may be interchanged.

By collectively adding the S cell and allocating the PUCCH area for the S cell in this way, it is possible to quickly obtain the effect of improving the throughput by expanding the bandwidth by CA under low traffic (Fig.). 4).

<Step-by-step control>
In the stepwise control, the on or off control of the CA may be determined in multiple steps based on a plurality of threshold values regarding the tightness of the PUSCH band (for example, the traffic of the base station). For example, the base station may stepwise control the non-setting (deletion) of the S cell and the configuration change of the PUSCH band in the control of CA off. Further, in the control of CA ON, the setting of S cell (start of CA) and the addition of S cell (change of the number of S cells) may be controlled stepwise.

≪Judgment operation≫
FIG. 8 is a diagram showing an example of the relationship between traffic and throughput in the stepwise control according to the second aspect. As shown in FIG. 8, in the stepwise control, the base station uses a plurality of threshold values (for example, threshold values 1 to 3 in FIG. 8) to determine the number of S cells and the configuration of the PUSCH band within the cell bandwidth. May be switched. In FIG. 8, the differences from FIG. 4 will be mainly described.

For example, as shown in FIG. 8, and when the traffic is less than (or less than or equal to) the threshold value 1 (first threshold value), the base station may perform CA with X cells S cells and P cells. Good. If the traffic is greater than or equal to (or greater than) threshold 1 and less than (or less than or equal to) threshold 2 (second threshold), the base station will include Y (Y <X) S and P cells. You may perform CA at.

Further, when the traffic is (or is greater than) a threshold value of 2 or more and is less than (or less than or equal to) a threshold value of 3 (third threshold value), the base station deletes all cells set as S cells (that is, , CA may be released). Further, when the traffic is 3 or more (or larger than) the threshold value, the base station may release the PUCCH region for the S cell to expand the PUSCH band.

As shown in FIG. 8, the plurality of thresholds used for the stepwise control may be set based on the traffic point (switching point) at which the throughput is maximized. As shown in FIG. 8, when the on or off of CA is controlled stepwise using a plurality of threshold values, the throughput can be controlled more flexibly.

The number of threshold values shown in FIG. 8 is merely an example, and a threshold value of 4 or more may be used, or one or two threshold values may be used. Further, the plurality of threshold values may be threshold values of the same parameter, and at least one of the plurality of threshold values may be a threshold value of different parameters. Further, in FIG. 8, four stages of control are shown, but some stages may be deleted, and controls (not shown) (for example, a stage of performing CA of Z (Z> X) S cells). May be added.

≪Stepwise control operation≫
Next, the detailed operation of the stepwise control of turning off and on of the CA according to the second aspect will be described.

9A-9C are conceptual diagrams of stepwise control according to the second aspect. For example, in FIG. 9A, CA (an example of an on state) of P cell and X (here, for example, 2) S cells is shown. In FIG. 9B, CA (another example in the on state) of P cells and Y cells (here, for example, 1) of S cells is shown. FIG. 9C shows an example of the CA off state. 10A-10D show an example of the configuration within the cell band.

In FIG. 9A, the UE may receive PDSCH in cells P and S cells # 0 and # 1, respectively. The UE may transmit the A / N for the PDSCH received in the three cells by using the PUCCH or the PUSCH of the P cell. In this case, as shown in FIG. 10A, a PUCCH region for the S cell is secured within the bandwidth of the P cell, and the PUSCH has a UCI (for example, A / N and CSI for the PDSCH of the P cell and the S cell). And at least one of SR) may be multiplexed. Further, a CA-related control signal (for example, an RRC message) or the like may be multiplexed on the PUSCH.

Further, in FIG. 9B, the UE may receive the PDSCH in the P cell and the S cell # 0. The UE may transmit the A / N for the PDSCH received in the two cells by using the PUCCH or the PUSCH of the P cell. In this case, as shown in FIG. 10B, the PUCCH area for the S cell is secured within the bandwidth of the P cell, but due to the decrease in the number of S cells, the UCI multiplexed on the PUSCH is compared with that of FIG. 10A. May decrease.

Further, in FIG. 9C, the UE may receive the PDSCH in the P cell. The UE may transmit an A / N for a PDSCH received in one cell using the PUCCH or PUSCH of the P cell. In this case, as shown in FIG. 10C, the PUCCH area for the S cell is secured within the bandwidth of the P cell, but due to the deletion of the S cell, the UCI of the S cell is not multiplexed on the PUSCH. Good.

Further, as shown in FIG. 10D, the base station determines the PUCCH region for the S cell when a predetermined condition is satisfied (for example, in FIG. 8, when the traffic is at or above the threshold value 3 (or becomes larger)). It may be released to extend the PUSCH band.

FIG. 11 is a diagram showing an example of the operation of the stepwise control of CA off according to the second aspect. In addition, in FIG. 11, the difference from FIG. 6 will be mainly described. Further, in FIG. 11, as described with reference to FIG. 8, four-step control is shown, but the control is not limited to this. If the above-mentioned (1) S cell setting process and (2) configuration change process are performed at least separately, the control may be performed in three stages (for example, CA on, all cell deletion, PUSCH bandwidth expansion), and 5 The control may be more than one step.

In step S301, the base station monitors traffic at predetermined intervals. In step S301, the base station determines whether the monitored traffic is equal to or greater than the threshold value 1. If the traffic is less than the threshold value 1 (step S302; NO), this operation returns to step S301. Although not shown, in step S302, it may be determined whether or not the monitored traffic is greater than the threshold value 1.

When the traffic is equal to or higher than the threshold value 1 (step S302; YES), in step S303, the base station deletes a part of the S cell integrated with the P cell by CA (see, for example, FIGS. 9B and 10B). Specifically, the base station transmits information (for example, S cell index, etc.) about some cells to be deleted from the S cell setting to the UE. Information about the cell to be deleted may be included, for example, in the RRC reset message.

In step S304, the UE may send a response message to the base station when some cells are deleted from the S cell settings based on the information received from the base station. The response message may be, for example, an RRC reset completion message.

Further, the base station may stop scheduling in the deleted S cell. By stopping the PDSCH scheduling in the S cell, as shown in FIG. 10B, the UCI multiplexed on the PUSCH (for example, A / N for the PDSCH transmitted in the S cell) can be reduced.

In step S305, the base station monitors traffic at predetermined intervals. In step S306, the base station determines whether the monitored traffic is greater than or equal to the threshold value 2. If the traffic is less than the threshold value 2 (step S306; NO), this operation returns to step S305. Although not shown, in step S306, it may be determined whether or not the monitored traffic is greater than the threshold value 2.

When the traffic is threshold value 2 or more (step S306; YES), in step S307, the base station deletes all the S cells integrated with the P cell by CA (see, for example, FIGS. 9C and 10C). Specifically, the base station transmits information about the cell to be deleted from the S cell setting (for example, the S cell index) to the UE. Information about the cell to be deleted may be included, for example, in the RRC reset message.

In step S308, the UE may send a response message to the base station after deleting all S cells based on the information received from the base station. The response message may be, for example, an RRC reset completion message.

Further, the base station may stop scheduling in all the S cells. By stopping the PDSCH scheduling in the S cell, as shown in FIG. 10C, the UCI multiplexed on the PUSCH (for example, A / N for the PDSCH transmitted in the S cell) can be reduced.

In step S309, the base station monitors traffic at predetermined intervals. In step S310, the base station determines whether the monitored traffic is equal to or greater than the threshold value 3. If the traffic is less than the threshold 3 (step S310; NO), the operation returns to step S309. Although not shown, in step S310, it may be determined whether or not the monitored traffic is greater than the threshold value 3.

When the traffic is a threshold value of 3 or more (step S310; YES), in step S311 the base station may extend the PUSCH band of the P cell. Specifically, as shown in FIG. 10D, the base station may release the PUCCH area for the S cell secured within the bandwidth of the P cell and allocate the PUCCH area for the S cell to the PUSCH. Good.

In this way, by controlling the number of S cells and the expansion of the PUSCH band by releasing the PUCCH area for the S cells stepwise, the throughput can be controlled more flexibly according to the traffic.

FIG. 12 is a diagram showing an example of the operation of the stepwise control of CA ON according to the second aspect. In addition, in FIG. 12, the difference from FIG. 11 will be mainly described. Step S401 of FIG. 12 is the same as step S301 of FIG.

In step S402, the base station determines whether the monitored traffic is equal to or greater than the threshold value 3. When the traffic is equal to or higher than the threshold value 3 (step S402; YES), this operation returns to step S401. Although not shown, in step S402, it may be determined whether or not the monitored traffic is greater than the threshold value 3.

If the traffic is less than the threshold 3 (step S402; NO), in step S403, the base station may reduce the PUSCH band of the P cell. Specifically, as shown in FIGS. 10A to 10C, even if the base station secures a PUCCH area for the S cell within the bandwidth of the P cell and cannot allocate the PUCCH area for the S cell to the PUSCH. Good.

In step S404, the base station monitors traffic at predetermined intervals. In step S405, the base station determines whether the monitored traffic is equal to or greater than the threshold value 2. When the traffic is equal to or higher than the threshold value 2 (step S405; YES), this operation returns to step S404. Although not shown, in step S405, it may be determined whether or not the monitored traffic is greater than the threshold value 2.

If the traffic is less than the threshold 2 (step S405; NO), in step S406, the base station initiates CA (see, eg, FIGS. 9B and 10B). Specifically, the base station transmits information about the cell to be set as the S cell (for example, the S cell index) to the UE. Information about the cell may be included, for example, in the RRC reset message.

In step S407, the UE may send a response message to the base station by adding an S cell based on the information received from the base station. The response message may be, for example, an RRC reset completion message.

In step S407, the base station may start scheduling the S cell. By starting the scheduling of the PDSCH in the S cell, for example, the A / N for the PDSCH transmitted in the S cell is multiplexed and transmitted in the PUCCH area for the S cell or the PUSCH.

Similar to S404 to S407, in S408 to S411, an S cell to be CA may be added by determining whether or not the traffic is a threshold value of 1 or more.

In this way, by controlling the number of S cells and the allocation of the PUCCH area for the S cells stepwise, the throughput can be controlled more flexibly according to the traffic.

According to the second aspect described above, the CA can be turned on or off collectively or stepwise according to the tightness of the PUSCH band (for example, the “base station traffic” described in the first aspect). , Throughput can be maximized according to traffic.

Further, according to the second aspect, the CA can be turned on or off autonomously without restarting the base station (without changing the setting accompanied by the restart). As a result, the CA can be switched on or off while the user's wireless communication is continued, and communication interruption due to the switching can be prevented.

(Other aspects)
The "base station traffic" described in the first aspect is assumed to be monitored (estimated) by the base station, but is not limited thereto. The "base station traffic" may be monitored by a device on the core network or by a device on the radio access network.

The collective control and the stepwise control described in the second aspect are assumed to be performed by the base station, but are not limited thereto. The collective control and the stepwise control may be performed by a device on the core network or may be performed by a device on the radio access network.

Further, in the collective control and the stepwise control described in the second aspect, hysteresis may be applied to the determination of the threshold value. For example, in FIG. 4, the base station autonomously switches between CA on and CA off depending on whether or not the traffic is equal to or higher than a predetermined threshold, but in the base station, the traffic is within a predetermined range (hysteresis) from the predetermined threshold. CA on or CA off may be autonomously switched depending on whether or not it belongs to the width).

Further, in step S102 of FIG. 6, even if the traffic becomes equal to or higher than (or larger than) the predetermined threshold value, if the traffic falls within a predetermined range (hysteresis width) from the predetermined threshold value, the UE performs the step S101. When the value exceeds the predetermined range, the operation of switching the CA from on to off (for example, step S103 or later) may be performed.

Further, in step S202 of FIG. 7, even if the traffic is smaller than (or less than or equal to) the predetermined threshold value, if the traffic belongs within a predetermined range (hysteresis width) from the predetermined threshold value, the UE is in step S201. When the value exceeds the predetermined range, the operation of switching the CA from on to off (for example, step S203 or later) may be performed.

Further, in steps S302, S306, and S310 of FIG. 11, hysteresis may be considered as in step S102 of FIG. Further, in steps S402, S405, and S409 of FIG. 12, hysteresis may be considered in the same manner as in step S202 of FIG.

Further, in the stepwise control illustrated in FIGS. 10 to 12, the XY S cells are deleted on the premise that the CA is turned on with the X S cells, and the CA with the Y (Y <X) S cells is deleted. In the continuous state (transient state) (for example, S305 in FIG. 11 or S408 in FIG. 12), if the monitored traffic is a threshold value of 2 or more (for example, step S306 in FIG. 11; YES), all cells are If deleted and the traffic is less than threshold 1 (eg, step S409; NO in FIG. 12), XY S cells are added (CA with X S cells is started). Not limited to.

For example, in the transient state (eg, S305 of FIG. 11), the monitored traffic may be compared to at least one of threshold 2 and threshold 3. The UE may perform processing corresponding to the threshold value at which the traffic monitored in the transient state satisfies the condition first. Specifically, when the traffic first reaches the threshold value 2 or more, Y S cells are deleted (for example, steps S307 and S308), and when the traffic first reaches the threshold value 3 or more, or the PUSCH band. The width expansion process (for example, step S311) may be performed.

Further, when the traffic monitored in the above transient state (for example, S305 in FIG. 11) is a threshold value of 3 or more, the UE deletes Y S cells and then performs the next monitoring without performing the next monitoring of the PUSCH. Bandwidth may be extended. As described above, the collective control and the stepwise control described in the second aspect may be combined.

Also, in a reduced PUSCH bandwidth (eg, S404 in FIG. 12), the monitored traffic may be compared to at least one of threshold 2 and threshold 1. The UE may perform processing corresponding to the threshold value at which the traffic monitored in the reduced state satisfies the condition first. Specifically, if the traffic is smaller than the threshold value 2, CA start processing with Y S cells is performed (for example, steps S406 and S407), and if the traffic is smaller than the threshold value 1 first. CA start processing with X (> Y) S cells may be performed.

Further, in the present specification, "above a certain threshold value" and "greater than a certain threshold value" may be paraphrased with each other. Further, "less than a certain threshold value" and "below a certain threshold value" may be paraphrased with each other. As described above, in the determination of traffic in the present specification, it is sufficient that the traffic is compared with a certain threshold value, and it does not matter whether the traffic includes the threshold value or not in the comparison.

(Wireless communication system)
Hereinafter, the configuration of the wireless communication system according to the embodiment of the present disclosure will be described. In this wireless communication system, communication is performed using at least one combination of the above aspects of the present disclosure.

FIG. 13 is a diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. The wireless communication system 1 may be a system that realizes communication using Long Term Evolution (LTE), 5th generation mobile communication system New Radio (5G NR), etc. specified by the Third Generation Partnership Project (3GPP). ..

In addition, the wireless communication system 1 may support dual connectivity between a plurality of Radio Access Technologies (RATs) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC is a dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), and a dual connectivity between NR and LTE (NR-E). -UTRA Dual Connectivity (NE-DC)) and the like may be included.

In EN-DC, the LTE (E-UTRA) base station (eNB) is the master node (Master Node (MN)), and the NR base station (gNB) is the secondary node (Secondary Node (SN)). In NE-DC, the base station (gNB) of NR is MN, and the base station (eNB) of LTE (E-UTRA) is SN.

The wireless communication system 1 has dual connectivity between a plurality of base stations in the same RAT (for example, dual connectivity (NR-NR Dual Connectivity (NN-DC)) in which both MN and SN are NR base stations (gNB). )) May be supported.

The wireless communication system 1 includes a base station 11 that forms a macro cell C1 having a relatively wide coverage, and a base station 12 (12a-12c) that is arranged in the macro cell C1 and forms a small cell C2 that is narrower than the macro cell C1. You may prepare. The user terminal 20 may be located in at least one cell. The arrangement, number, and the like of each cell and the user terminal 20 are not limited to the mode shown in the figure. Hereinafter, when the base stations 11 and 12 are not distinguished, they are collectively referred to as the base station 10.

The user terminal 20 may be connected to at least one of the plurality of base stations 10. The user terminal 20 may use at least one of carrier aggregation (CA) and dual connectivity (DC) using a plurality of component carriers (Component Carriers (CC)).

Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). The macro cell C1 may be included in FR1 and the small cell C2 may be included in FR2. For example, FR1 may be in a frequency band of 6 GHz or less (sub 6 GHz (sub-6 GHz)), and FR2 may be in a frequency band higher than 24 GHz (above-24 GHz). The frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may correspond to a frequency band higher than FR2.

Further, the user terminal 20 may perform communication using at least one of Time Division Duplex (TDD) and Frequency Division Duplex (FDD) in each CC.

The plurality of base stations 10 may be connected by wire (for example, optical fiber compliant with Common Public Radio Interface (CPRI), X2 interface, etc.) or wirelessly (for example, NR communication). For example, when NR communication is used as a backhaul between base stations 11 and 12, the base station 11 corresponding to the host station is the Integrated Access Backhaul (IAB) donor, and the base station 12 corresponding to the relay station (relay) is the IAB. It may be called a node.

The base station 10 may be connected to the core network 30 via another base station 10 or directly. The core network 30 may include, for example, at least one such as Evolved Packet Core (EPC), 5G Core Network (5GCN), and Next Generation Core (NGC).

The user terminal 20 may be a terminal that supports at least one of communication methods such as LTE, LTE-A, and 5G.

In the wireless communication system 1, a wireless access system based on Orthogonal Frequency Division Multiplexing (OFDM) may be used. For example, at least one of downlink (Downlink (DL)) and uplink (Uplink (UL)), Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple. Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), and the like may be used.

The wireless access method may be referred to as a waveform. In the wireless communication system 1, another wireless access system (for example, another single carrier transmission system, another multi-carrier transmission system) may be used as the UL and DL wireless access systems.

In the wireless communication system 1, as downlink channels, downlink shared channels (Physical Downlink Shared Channel (PDSCH)), broadcast channels (Physical Broadcast Channel (PBCH)), and downlink control channels (Physical Downlink Control) shared by each user terminal 20 are used. Channel (PDCCH)) and the like may be used.

Further, in the wireless communication system 1, as the uplink channel, the uplink shared channel (Physical Uplink Shared Channel (PUSCH)), the uplink control channel (Physical Uplink Control Channel (PUCCH)), and the random access channel shared by each user terminal 20 are used. (Physical Random Access Channel (PRACH)) and the like may be used.

User data, upper layer control information, System Information Block (SIB), etc. are transmitted by PDSCH. User data, upper layer control information, and the like may be transmitted by the PUSCH. In addition, the Master Information Block (MIB) may be transmitted by the PBCH.

Lower layer control information may be transmitted by the PDCCH. The lower layer control information may include, for example, downlink control information (DCI) including scheduling information of at least one of PDSCH and PUSCH.

The DCI that schedules PDSCH may be called DL assignment, DL DCI, or the like, and the DCI that schedules PUSCH may be called UL grant, UL DCI, or the like. The PDSCH may be read as DL data, and the PUSCH may be read as UL data.

A search space may be used for the detection of PDCCH. The search space corresponds to the search area and search method of PDCCH candidates. One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels.

Depending on the PUCCH, Channel State Information (CSI), delivery confirmation information (eg, may be referred to as Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.) and Scheduling Request (Scheduling Request). Uplink Control Information (UCI) containing at least one of SR)) may be transmitted. The PRACH may transmit a random access preamble to establish a connection with the cell.

In this disclosure, downlinks, uplinks, etc. may be expressed without "links". Further, it may be expressed without adding "Physical" at the beginning of various channels.

In the wireless communication system 1, a synchronization signal (Synchronization Signal (SS)), a downlink reference signal (DL-RS), and the like may be transmitted. In the wireless communication system 1, the DL-RS includes a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), and a demodulation reference signal (DeModulation). Reference Signal (DMRS)), positioning reference signal (PRS), phase tracking reference signal (PTRS), and the like may be transmitted.

Further, in the wireless communication system 1, even if a measurement reference signal (Sounding Reference Signal (SRS)), a demodulation reference signal (DMRS), or the like is transmitted as an uplink reference signal (UL-RS). Good. The DMRS may be called a user terminal specific reference signal (UE-specific reference signal).

(base station)
FIG. 14 is a diagram showing an example of the configuration of the base station according to the embodiment. The base station 10 includes a control unit 110, a transmission / reception unit 120, a transmission / reception antenna 130, and a transmission line interface 140. The control unit 110, the transmission / reception unit 120, the transmission / reception antenna 130, and the transmission line interface 140 may each be provided with one or more.

In this example, the functional blocks of the feature portion in the present embodiment are mainly shown, and it may be assumed that the base station 10 also has other functional blocks necessary for wireless communication. A part of the processing of each part described below may be omitted.

The control unit 110 controls the entire base station 10. The control unit 110 can be composed of a controller, a control circuit, and the like described based on the common recognition in the technical field according to the present disclosure.

The control unit 110 may control signal generation, scheduling (for example, resource allocation, mapping) and the like. The control unit 110 may control transmission / reception, measurement, and the like using the transmission / reception unit 120, the transmission / reception antenna 130, and the transmission line interface 140. The control unit 110 may generate data to be transmitted as a signal, control information, a sequence, and the like, and transfer the data to the transmission / reception unit 120. The control unit 110 may perform call processing (setting, release, etc.) of the communication channel, state management of the base station 10, management of radio resources, and the like.

The transmission / reception unit 120 may include a baseband unit 121, a radio frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may include a transmission processing unit 1211 and a reception processing unit 1212. The transmitter / receiver 120 includes a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transmitter / receiver circuit, and the like, which are described based on common recognition in the technical fields according to the present disclosure. be able to.

The transmission / reception unit 120 may be configured as an integrated transmission / reception unit, or may be composed of a transmission unit and a reception unit. The transmission unit may be composed of a transmission processing unit 1211 and an RF unit 122. The receiving unit may be composed of a receiving processing unit 1212, an RF unit 122, and a measuring unit 123.

The transmitting / receiving antenna 130 can be composed of an antenna described based on common recognition in the technical field according to the present disclosure, for example, an array antenna.

The transmission / reception unit 120 may transmit the above-mentioned downlink channel, synchronization signal, downlink reference signal, and the like. The transmission / reception unit 120 may receive the above-mentioned uplink channel, uplink reference signal, and the like.

The transmission / reception unit 120 may form at least one of a transmission beam and a reception beam by using digital beamforming (for example, precoding), analog beamforming (for example, phase rotation), and the like.

The transmission / reception unit 120 (transmission processing unit 1211) processes, for example, the Packet Data Convergence Protocol (PDCP) layer and the Radio Link Control (RLC) layer for data, control information, etc. acquired from the control unit 110 (for example,). RLC retransmission control), Medium Access Control (MAC) layer processing (for example, HARQ retransmission control), and the like may be performed to generate a bit string to be transmitted.

The transmission / reception unit 120 (transmission processing unit 1211) performs channel coding (may include error correction coding), modulation, mapping, filtering, and discrete Fourier transform (DFT) for the bit string to be transmitted. The baseband signal may be output by performing processing (if necessary), transmission processing such as Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-analog transformation.

The transmission / reception unit 120 (RF unit 122) may perform modulation, filtering, amplification, etc. on the baseband signal to the radio frequency band, and transmit the signal in the radio frequency band via the transmission / reception antenna 130. ..

On the other hand, the transmission / reception unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, and the like on the radio frequency band signal received by the transmission / reception antenna 130.

The transmission / reception unit 120 (reception processing unit 1212) performs analog-digital transform, fast Fourier transform (FFT) processing, and inverse discrete Fourier transform (IDFT) on the acquired baseband signal. )) Processing (if necessary), filtering, decoding, demodulation, decoding (may include error correction decoding), MAC layer processing, RLC layer processing, PDCP layer processing, and other reception processing are applied. User data and the like may be acquired.

The transmission / reception unit 120 (measurement unit 123) may perform measurement on the received signal. For example, the measuring unit 123 may perform Radio Resource Management (RRM) measurement, Channel State Information (CSI) measurement, or the like based on the received signal. The measuring unit 123 receives received power (for example, Reference Signal Received Power (RSRP)), reception quality (for example, Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR)). , Signal strength (eg, Received Signal Strength Indicator (RSSI)), propagation path information (eg, CSI), and the like. The measurement result may be output to the control unit 110.

The transmission line interface 140 transmits / receives signals (backhaul signaling) to / from a device included in the core network 30, another base station 10 and the like, and provides user data (user plane data) and control plane for the user terminal 20. Data or the like may be acquired or transmitted.

The transmission unit and the reception unit of the base station 10 in the present disclosure may be composed of at least one of the transmission / reception unit 120, the transmission / reception antenna 130, and the transmission line interface 140.

The transmission / reception unit 120 may transmit information regarding the S cell set in the user terminal 20. Specifically, the transmission / reception unit 120 may transmit information regarding a cell to be deleted or added from the S cell set in the user terminal 20. Information about the cell may be included, for example, in the RRC reset message. Further, the transmission / reception unit 120 may receive a response message (for example, an RRC resetting completion message) for the information regarding the cell.

Further, the transmission / reception unit 120 transmits a downlink shared channel (for example, PDSCH) in a second cell (for example, S cell) integrated with the first cell (for example, P cell) by carrier aggregation (CA). May be good. Further, the transmission / reception unit 120 is an uplink control channel (for example, PUCCH) assigned to a predetermined frequency region of the first cell, or an uplink shared channel assigned to a frequency region other than the predetermined frequency region of the first cell. (For example, PUSCH) may be used to receive delivery confirmation information for the downlink shared channel.

Further, the control unit 110 may control the on / off switching of the CA based on the traffic in at least one of the first and second cells integrated by the CA.

Specifically, the control unit 110 may switch off the carrier aggregation when the traffic is equal to or greater than a predetermined threshold (for example, the threshold in FIG. 4, the threshold 2 in FIG. 8 and the like).

In this case, the control unit 110 deletes the second cell integrated with the first cell by CA, and for the uplink control channel assigned to the predetermined frequency domain of the first cell for the second cell. At least one of the release of resources may be controlled (eg, FIGS. 6 and 11).

Further, the control unit 110 may switch the carrier aggregation on when the traffic is smaller than or less than a predetermined threshold value (for example, the threshold value of FIG. 4, the threshold value 2 of FIG. 8 or the like).

In this case, the control unit 110 may control at least one of the setting of the second cell to be integrated with the first cell by CA and the addition of the second cell (for example, FIG. 7, FIG. 12).

(User terminal)
FIG. 15 is a diagram showing an example of the configuration of the user terminal according to the embodiment. The user terminal 20 includes a control unit 210, a transmission / reception unit 220, and a transmission / reception antenna 230. The control unit 210, the transmission / reception unit 220, and the transmission / reception antenna 230 may each be provided with one or more.

In this example, the functional blocks of the feature portion in the present embodiment are mainly shown, and it may be assumed that the user terminal 20 also has other functional blocks necessary for wireless communication. A part of the processing of each part described below may be omitted.

The control unit 210 controls the entire user terminal 20. The control unit 210 can be composed of a controller, a control circuit, and the like described based on the common recognition in the technical field according to the present disclosure.

The control unit 210 may control signal generation, mapping, and the like. The control unit 210 may control transmission / reception, measurement, and the like using the transmission / reception unit 220 and the transmission / reception antenna 230. The control unit 210 may generate data to be transmitted as a signal, control information, a sequence, and the like, and transfer the data to the transmission / reception unit 220.

The transmission / reception unit 220 may include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may include a transmission processing unit 2211 and a reception processing unit 2212. The transmitter / receiver 220 can be composed of a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transmitter / receiver circuit, and the like, which are described based on the common recognition in the technical field according to the present disclosure.

The transmission / reception unit 220 may be configured as an integrated transmission / reception unit, or may be composed of a transmission unit and a reception unit. The transmission unit may be composed of a transmission processing unit 2211 and an RF unit 222. The receiving unit may be composed of a receiving processing unit 2212, an RF unit 222, and a measuring unit 223.

The transmitting / receiving antenna 230 can be composed of an antenna described based on common recognition in the technical field according to the present disclosure, for example, an array antenna.

The transmission / reception unit 220 may receive the above-mentioned downlink channel, synchronization signal, downlink reference signal, and the like. The transmission / reception unit 220 may transmit the above-mentioned uplink channel, uplink reference signal, and the like.

The transmission / reception unit 220 may form at least one of a transmission beam and a reception beam by using digital beamforming (for example, precoding), analog beamforming (for example, phase rotation), and the like.

The transmission / reception unit 220 (transmission processing unit 2211) performs PDCP layer processing, RLC layer processing (for example, RLC retransmission control), and MAC layer processing (for example, for data, control information, etc. acquired from the control unit 210). , HARQ retransmission control), etc., to generate a bit string to be transmitted.

The transmission / reception unit 220 (transmission processing unit 2211) performs channel coding (may include error correction coding), modulation, mapping, filtering processing, DFT processing (if necessary), and IFFT processing for the bit string to be transmitted. , Precoding, digital-to-analog conversion, and other transmission processing may be performed to output the baseband signal.

Whether or not to apply the DFT process may be based on the transform precoding setting. The transmission / reception unit 220 (transmission processing unit 2211) described above for transmitting a channel (for example, PUSCH) using the DFT-s-OFDM waveform when the transform precoding is enabled. The DFT process may be performed as the transmission process, and if not, the DFT process may not be performed as the transmission process.

The transmission / reception unit 220 (RF unit 222) may perform modulation, filtering, amplification, etc. on the baseband signal to the radio frequency band, and transmit the signal in the radio frequency band via the transmission / reception antenna 230. ..

On the other hand, the transmission / reception unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, and the like on the radio frequency band signal received by the transmission / reception antenna 230.

The transmission / reception unit 220 (reception processing unit 2212) performs analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filtering processing, demapping, demodulation, and decoding (error correction) for the acquired baseband signal. Decoding may be included), MAC layer processing, RLC layer processing, PDCP layer processing, and other reception processing may be applied to acquire user data and the like.

The transmission / reception unit 220 (measurement unit 223) may perform measurement on the received signal. For example, the measuring unit 223 may perform RRM measurement, CSI measurement, or the like based on the received signal. The measuring unit 223 may measure received power (for example, RSRP), reception quality (for example, RSRQ, SINR, SNR), signal strength (for example, RSSI), propagation path information (for example, CSI), and the like. The measurement result may be output to the control unit 210.

The transmission unit and the reception unit of the user terminal 20 in the present disclosure may be composed of at least one of the transmission / reception unit 220 and the transmission / reception antenna 230.

The transmission / reception unit 220 may receive information about the S cell set in the user terminal 20. Specifically, the transmission / reception unit 220 may receive information about a cell to be deleted or added from the S cell set in the user terminal 20. Information about the cell may be included, for example, in the RRC reset message. Further, the transmission / reception unit 220 may transmit a response message (for example, an RRC reset completion completion message) for the information regarding the cell.

Further, the transmission / reception unit 220 receives the downlink shared channel (for example, PDSCH) in the second cell (for example, S cell) integrated with the first cell (for example, P cell) by carrier aggregation (CA). May be good. Further, the transmission / reception unit 220 is an uplink control channel (for example, PUCCH) assigned to a predetermined frequency region of the first cell, or an uplink shared channel assigned to a frequency region other than the predetermined frequency region of the first cell. (For example, PUSCH) may be used to transmit delivery confirmation information for the downlink shared channel.

Further, the control unit 210 turns the CA on or off based on the instruction information from the base station 10 determined based on the traffic in at least one of the first and second cells integrated by the CA. Switching may be controlled.

The control unit 210 sets (for example, at least one of setting, addition, and deletion) of one or more second cells (for example, S cell) to be integrated with the first cell (for example, P cell) for CA. May be controlled. Specifically, the control unit 210 may control at least one of the setting, addition, and deletion of the S cell based on the information about the cell received from the base station 10 (for example, FIGS. 6, 7, and 11). , 12). The control may be performed by resetting the RRC connection.

(Hardware configuration)
The block diagram used in the description of the above embodiment shows a block of functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Further, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized by using one device that is physically or logically connected, or directly or indirectly (for example, by two or more devices that are physically or logically separated). , Wired, wireless, etc.) and may be realized using these plurality of devices. The functional block may be realized by combining the software with the one device or the plurality of devices.

Here, the functions include judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, selection, establishment, comparison, assumption, expectation, and deemed. , Broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, assigning, etc. Not limited. For example, a functional block (constituent unit) for functioning transmission may be referred to as a transmitting unit, a transmitter, or the like. As described above, the method of realizing each of them is not particularly limited.

For example, the base station, user terminal, and the like in one embodiment of the present disclosure may function as a computer that processes the wireless communication method of the present disclosure. FIG. 16 is a diagram showing an example of the hardware configuration of the base station and the user terminal according to the embodiment. The base station 10 and the user terminal 20 described above may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like. ..

In addition, in this disclosure, the wording of a device, a circuit, a device, a section, a unit and the like can be read as each other. The hardware configuration of the base station 10 and the user terminal 20 may be configured to include one or more of the devices shown in the figure, or may be configured not to include some of the devices.

For example, although only one processor 1001 is shown, there may be multiple processors. Further, the processing may be executed by one processor, or the processing may be executed simultaneously, sequentially, or by using other methods by two or more processors. The processor 1001 may be mounted by one or more chips.

For each function of the base station 10 and the user terminal 20, for example, by loading predetermined software (program) on hardware such as the processor 1001 and the memory 1002, the processor 1001 performs an operation and communicates via the communication device 1004. It is realized by controlling at least one of reading and writing of data in the memory 1002 and the storage 1003.

Processor 1001 operates, for example, an operating system to control the entire computer. The processor 1001 may be configured by a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, registers, and the like. For example, at least a part of the above-mentioned control unit 110 (210), transmission / reception unit 120 (220), and the like may be realized by the processor 1001.

Further, the processor 1001 reads a program (program code), a software module, data, and the like from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and executes various processes according to these. As the program, a program that causes a computer to execute at least a part of the operations described in the above-described embodiment is used. For example, the control unit 110 (210) may be realized by a control program stored in the memory 1002 and operating in the processor 1001, and may be realized in the same manner for other functional blocks.

The memory 1002 is a computer-readable recording medium, such as at least a Read Only Memory (ROM), an Erasable Programmable ROM (EPROM), an Electrically EPROM (EEPROM), a Random Access Memory (RAM), or any other suitable storage medium. It may be composed of one. The memory 1002 may be referred to as a register, a cache, a main memory (main storage device), or the like. The memory 1002 can store a program (program code), a software module, or the like that can be executed to implement the wireless communication method according to the embodiment of the present disclosure.

The storage 1003 is a computer-readable recording medium, for example, a flexible disk, a floppy (registered trademark) disk, an optical magnetic disk (for example, a compact disc ROM (CD-ROM), etc.), a digital versatile disk, and the like. At least one of Blu-ray® disks, removable disks, optical disc drives, smart cards, flash memory devices (eg cards, sticks, key drives), magnetic stripes, databases, servers, and other suitable storage media. It may be composed of. The storage 1003 may be referred to as an auxiliary storage device.

The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, or the like. The communication device 1004 includes, for example, a high frequency switch, a duplexer, a filter, a frequency synthesizer, etc. in order to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). May be configured to include. For example, the transmission / reception unit 120 (220), the transmission / reception antenna 130 (230), and the like described above may be realized by the communication device 1004. The transmission / reception unit 120 (220) may be physically or logically separated from the transmission unit 120a (220a) and the reception unit 120b (220b).

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

Further, each device such as the processor 1001 and the memory 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured by using a single bus, or may be configured by using a different bus for each device.

Further, the base station 10 and the user terminal 20 include a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), a field programmable gate array (FPGA), and the like. It may be configured to include hardware, and a part or all of each functional block may be realized by using the hardware. For example, processor 1001 may be implemented using at least one of these hardware.

(Modification example)
The terms described in the present disclosure and the terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, channels, symbols and signals (signals or signaling) may be read interchangeably. Also, the signal may be a message. The reference signal may be abbreviated as RS, and may be referred to as a pilot, a pilot signal, or the like depending on the applied standard. Further, the component carrier (Component Carrier (CC)) may be referred to as a cell, a frequency carrier, a carrier frequency, or the like.

The radio frame may be composed of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting the wireless frame may be referred to as a subframe. Further, the subframe may be composed of one or more slots in the time domain. The subframe may have a fixed time length (eg, 1 ms) that is independent of numerology.

Here, the numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel. Numerology includes, for example, SubCarrier Spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, and radio frame configuration. , A specific filtering process performed by the transmitter / receiver in the frequency domain, a specific windowing process performed by the transmitter / receiver in the time domain, and the like may be indicated.

Slots may be composed of one or more symbols in the time domain (Orthogonal Frequency Division Multiplexing (OFDM) symbols, Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols, etc.). In addition, the slot may be a time unit based on numerology.

The slot may include a plurality of mini slots. Each minislot may consist of one or more symbols in the time domain. The mini-slot may also be referred to as a sub-slot. A minislot may consist of a smaller number of symbols than the slot. PDSCH (or PUSCH) transmitted in time units larger than the minislot may be referred to as PDSCH (PUSCH) mapping type A. The PDSCH (or PUSCH) transmitted using the minislot may be referred to as PDSCH (PUSCH) mapping type B.

Radio frames, subframes, slots, mini-slots and symbols all represent time units when transmitting signals. The radio frame, subframe, slot, minislot and symbol may have different names corresponding to each. The time units such as frames, subframes, slots, mini slots, and symbols in the present disclosure may be read as each other.

For example, one subframe may be referred to as TTI, a plurality of consecutive subframes may be referred to as TTI, and one slot or one minislot may be referred to as TTI. That is, at least one of the subframe and TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (eg, 1-13 symbols), or a period longer than 1 ms. It may be. The unit representing TTI may be called a slot, a mini slot, or the like instead of a subframe.

Here, TTI refers to, for example, the minimum time unit of scheduling in wireless communication. For example, in the LTE system, the base station schedules each user terminal to allocate radio resources (frequency bandwidth that can be used in each user terminal, transmission power, etc.) in TTI units. The definition of TTI is not limited to this.

The TTI may be a transmission time unit such as a channel-encoded data packet (transport block), a code block, or a code word, or may be a processing unit such as scheduling or link adaptation. When a TTI is given, the time interval (for example, the number of symbols) to which the transport block, code block, code word, etc. are actually mapped may be shorter than the TTI.

When one slot or one minislot is called TTI, one or more TTIs (that is, one or more slots or one or more minislots) may be the minimum time unit for scheduling. Further, the number of slots (number of mini-slots) constituting the minimum time unit of the scheduling may be controlled.

A TTI having a time length of 1 ms may be referred to as a normal TTI (TTI in 3GPP Rel. 8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a slot, and the like. TTIs shorter than normal TTIs may be referred to as shortened TTIs, short TTIs, partial TTIs (partial or fractional TTIs), shortened subframes, short subframes, minislots, subslots, slots and the like.

The long TTI (for example, normal TTI, subframe, etc.) may be read as a TTI having a time length of more than 1 ms, and the short TTI (for example, shortened TTI, etc.) is less than the TTI length of the long TTI and 1 ms. It may be read as a TTI having the above TTI length.

A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers contained in the RB may be the same regardless of the numerology, and may be, for example, 12. The number of subcarriers contained in the RB may be determined based on numerology.

The RB may also include one or more symbols in the time domain and may be one slot, one minislot, one subframe or one TTI in length. Each 1TTI, 1 subframe, etc. may be composed of one or a plurality of resource blocks.

One or more RBs are a physical resource block (Physical RB (PRB)), a sub-carrier group (SCG), a resource element group (Resource Element Group (REG)), a PRB pair, and an RB. It may be called a pair or the like.

Further, the resource block may be composed of one or a plurality of resource elements (Resource Element (RE)). For example, 1RE may be a radio resource area of 1 subcarrier and 1 symbol.

Bandwidth Part (BWP) (which may also be called partial bandwidth, etc.) represents a subset of consecutive common resource blocks (RBs) for a neurology in a carrier. May be good. Here, the common RB may be specified by the index of the RB with respect to the common reference point of the carrier. PRBs may be defined in a BWP and numbered within that BWP.

The BWP may include UL BWP (BWP for UL) and DL BWP (BWP for DL). One or more BWPs may be set in one carrier for the UE.

At least one of the configured BWPs may be active and the UE may not expect to send or receive a given signal / channel outside the active BWP. In addition, "cell", "carrier" and the like in this disclosure may be read as "BWP".

The above-mentioned structures such as a wireless frame, a subframe, a slot, a minislot, and a symbol are merely examples. For example, the number of subframes contained in a wireless frame, the number of slots per subframe or wireless frame, the number of minislots contained within a slot, the number of symbols and RBs contained in a slot or minislot, included in the RB. The number of subcarriers, as well as the number of symbols in the TTI, the symbol length, the cyclic prefix (CP) length, and other configurations can be changed in various ways.

In addition, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, relative values from predetermined values, or using other corresponding information. It may be represented. For example, radio resources may be indicated by a given index.

The names used for parameters and the like in the present disclosure are not limited in any respect. Further, mathematical formulas and the like using these parameters may differ from those explicitly disclosed in this disclosure. Since the various channels (PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, the various names assigned to these various channels and information elements are not limiting in any way. ..

The information, signals, etc. described in the present disclosure may be represented using any of a variety of different techniques. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description are voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of these. It may be represented by a combination of.

In addition, information, signals, and the like can be output from the upper layer to the lower layer and from the lower layer to at least one of the upper layers. Information, signals, etc. may be input / output via a plurality of network nodes.

The input / output information, signals, and the like may be stored in a specific location (for example, a memory), or may be managed using a management table. Input / output information, signals, etc. can be overwritten, updated, or added. The output information, signals, etc. may be deleted. The input information, signals, etc. may be transmitted to other devices.

The notification of information is not limited to the embodiments / embodiments described in the present disclosure, and may be performed by other methods. For example, the notification of information in the present disclosure includes physical layer signaling (eg, downlink control information (DCI), uplink control information (UCI)), and higher layer signaling (eg, Radio Resource Control). (RRC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB), etc.), Medium Access Control (MAC) signaling), other signals or combinations thereof. May be carried out by.

The physical layer signaling may be referred to as Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signal), L1 control information (L1 control signal), and the like. Further, the RRC signaling may be referred to as an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like. Further, MAC signaling may be notified using, for example, a MAC control element (CE).

In addition, the notification of predetermined information (for example, the notification of "being X") is not limited to the explicit notification, but implicitly (for example, by not notifying the predetermined information or another information). May be done (by notification of).

The determination may be made by a value represented by 1 bit (0 or 1), or by a boolean value represented by true or false. , May be done by numerical comparison (eg, comparison with a given value).

Software, whether referred to as software, firmware, middleware, microcode, hardware description language, or by any other name, is an instruction, instruction set, code, code segment, program code, program, subprogram, software module. , Applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, features, etc. should be broadly interpreted.

Further, software, instructions, information and the like may be transmitted and received via a transmission medium. For example, the software uses at least one of wired technology (coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), etc.) and wireless technology (infrared, microwave, etc.) on the website. When transmitted from a server, or other remote source, at least one of these wired and wireless technologies is included within the definition of transmission medium.

The terms "system" and "network" used in this disclosure may be used interchangeably. The "network" may mean a device (eg, a base station) included in the network.

In the present disclosure, "precoding", "precoder", "weight (precoding weight)", "pseudo-colocation (Quasi-Co-Location (QCL))", "Transmission Configuration Indication state (TCI state)", "space". "Spatial relation", "spatial domain filter", "transmission power", "phase rotation", "antenna port", "antenna port group", "layer", "number of layers", Terms such as "rank", "resource", "resource set", "resource group", "beam", "beam width", "beam angle", "antenna", "antenna element", "panel" are compatible. Can be used for

In the present disclosure, "Base Station (BS)", "Radio Base Station", "Fixed Station", "NodeB", "eNB (eNodeB)", "gNB (gNodeB)", "Access point", "Transmission Point (TP)", "Reception Point (RP)", "Transmission / Reception Point (TRP)", "Panel" , "Cell", "sector", "cell group", "carrier", "component carrier" and the like can be used interchangeably. Base stations are sometimes referred to by terms such as macrocells, small cells, femtocells, and picocells.

The base station can accommodate one or more (eg, three) cells. When a base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, each smaller area being a base station subsystem (eg, a small indoor base station (Remote Radio)). Communication services can also be provided by Head (RRH))). The term "cell" or "sector" refers to part or all of the coverage area of at least one of the base stations and base station subsystems that provide communication services in this coverage.

In this disclosure, terms such as "mobile station (MS)", "user terminal", "user equipment (UE)", and "terminal" are used interchangeably. Can be done.

Mobile stations include subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless terminals, remote terminals. , Handset, user agent, mobile client, client or some other suitable term.

At least one of a base station and a mobile station may be referred to as a transmitting device, a receiving device, a wireless communication device, or the like. At least one of the base station and the mobile station may be a device mounted on the mobile body, the mobile body itself, or the like. The moving body may be a vehicle (for example, a car, an airplane, etc.), an unmanned moving body (for example, a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned type). ) May be. It should be noted that at least one of the base station and the mobile station includes a device that does not necessarily move during communication operation. For example, at least one of a base station and a mobile station may be an Internet of Things (IoT) device such as a sensor.

Further, the base station in the present disclosure may be read by the user terminal. For example, the communication between the base station and the user terminal is replaced with the communication between a plurality of user terminals (for example, it may be called Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.). Each aspect / embodiment of the present disclosure may be applied to the configuration. In this case, the user terminal 20 may have the function of the base station 10 described above. In addition, words such as "up" and "down" may be read as words corresponding to inter-terminal communication (for example, "side"). For example, an uplink channel, a downlink channel, and the like may be read as a side channel.

Similarly, the user terminal in the present disclosure may be read as a base station. In this case, the base station 10 may have the functions of the user terminal 20 described above.

In the present disclosure, the operation performed by the base station may be performed by its upper node in some cases. In a network including one or more network nodes having a base station, various operations performed for communication with a terminal are performed by one or more network nodes other than the base station and the base station (for example, the base station). Mobility Management Entity (MME), Serving-Gateway (S-GW), etc. are conceivable, but it is clear that it can be performed by (but not limited to) or a combination thereof.

Each aspect / embodiment described in the present disclosure may be used alone, in combination, or switched with execution. Further, the order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in the present disclosure may be changed as long as there is no contradiction. For example, the methods described in the present disclosure present elements of various steps using exemplary order, and are not limited to the particular order presented.

Each aspect / embodiment described in the present disclosure includes Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system ( 4G), 5th generation mobile communication system (5G), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM®), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi®), LTE 802.16 (WiMAX®), LTE 802. 20, Ultra-WideBand (UWB), Bluetooth®, other systems utilizing appropriate wireless communication methods, next-generation systems extended based on these, and the like may be applied. In addition, a plurality of systems may be applied in combination (for example, a combination of LTE or LTE-A and 5G).

The phrase "based on" as used in this disclosure does not mean "based on" unless otherwise stated. In other words, the statement "based on" means both "based only" and "at least based on".

Any reference to elements using designations such as "first", "second" as used in this disclosure does not generally limit the quantity or order of those elements. These designations can be used in the present disclosure as a convenient way to distinguish between two or more elements. Thus, references to the first and second elements do not mean that only two elements can be adopted or that the first element must somehow precede the second element.

The term "determining" as used in the present disclosure may include a wide variety of actions. For example, "judgment" means "judging", "calculating", "computing", "processing", "deriving", "investigating", "looking up", "search", "inquiry". For example, searching in a table, database or another data structure), ascertaining, etc. may be considered to be "judgment".

In addition, "judgment (decision)" includes receiving (for example, receiving information), transmitting (for example, transmitting information), input (input), output (output), and access (for example). It may be regarded as "judgment (decision)" such as "accessing" (for example, accessing data in memory).

In addition, "judgment (decision)" is regarded as "judgment (decision)" of solving, selecting, selecting, establishing, comparing, and the like. May be good. That is, "judgment (decision)" may be regarded as "judgment (decision)" of some action.

Further, "judgment (decision)" may be read as "assuming", "expecting", "considering" and the like.

The "maximum transmit power" described in the present disclosure may mean the maximum value of the transmit power, may mean the nominal UE maximum transmit power, or may mean the nominal UE maximum transmit power (the nominal UE maximum transmit power). It may mean rated UE maximum transmit power).

The terms "connected", "coupled", or any variation thereof, as used herein, are any direct or indirect connection or connection between two or more elements. Means, and can include the presence of one or more intermediate elements between two elements that are "connected" or "joined" to each other. The connection or connection between the elements may be physical, logical, or a combination thereof. For example, "connection" may be read as "access".

In the present disclosure, when two elements are connected, using one or more wires, cables, printed electrical connections, etc., and as some non-limiting and non-comprehensive examples, the radio frequency domain, microwaves. It can be considered to be "connected" or "coupled" to each other using frequency, electromagnetic energy having wavelengths in the light (both visible and invisible) regions, and the like.

In the present disclosure, the term "A and B are different" may mean "A and B are different from each other". The term may mean that "A and B are different from C". Terms such as "separate" and "combined" may be interpreted in the same way as "different".

When "include", "including" and variations thereof are used in the present disclosure, these terms are as comprehensive as the term "comprising". Is intended. Furthermore, the term "or" used in the present disclosure is intended not to be an exclusive OR.

In the present disclosure, if articles are added by translation, for example a, an and the in English, the disclosure may include that the nouns following these articles are in the plural.

Although the invention according to the present disclosure has been described in detail above, it is clear to those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described in the present disclosure. The invention according to the present disclosure can be implemented as an amended or modified mode without departing from the spirit and scope of the invention determined based on the description of the claims. Therefore, the description of the present disclosure is for purposes of illustration and does not bring any limiting meaning to the invention according to the present disclosure.

1: Wireless communication system 10: Base station 20: User terminal 30: Core network 110: Control unit 120: Transmission / reception unit 121: Baseband unit 1211: Transmission processing unit 1212: Reception processing unit 122: RF unit 123: Measurement unit 130: Transmission / reception antenna 140: Transmission path interface 210: Control unit 220: Transmission / reception unit 221: Baseband unit 2211: Transmission processing unit 2212: Reception processing unit 222: RF unit 223: Measurement unit 230: Transmission / reception antenna 1001: Processor 1002: Memory 1003: Storage 1004: Communication device 1005: Input device 1006: Output device 1007: Bus

Claims (5)

A transmitter that transmits a downlink shared channel in a second cell that is integrated with a first cell by carrier aggregation,
Delivery confirmation information for the downlink shared channel using the uplink control channel assigned to the predetermined frequency domain of the first cell or the uplink shared channel assigned to the frequency domain other than the predetermined frequency domain of the first cell. And the receiver that receives
A control unit that controls switching of carrier aggregation on or off based on traffic in at least one of the first cell and the second cell is provided.
When the traffic is equal to or greater than the first threshold value, the control unit switches off the carrier aggregation, deletes the second cell integrated with the first cell, and the traffic becomes the first. When it is equal to or greater than or greater than the second threshold value of 1 or more, the release of the uplink control channel resource allocated for the second cell and the release of the uplink control channel resource to the released area. Allocate the upstream shared channel
Said base station and a child. The base station according to claim 1, wherein the control unit switches the carrier aggregation on when the traffic is less than or equal to a predetermined threshold value. The control unit may set the second cell is integrated with the first cell, and a base according to claim 2, characterized by controlling at least one additional of said second cell Station. A transmitter that transmits a downlink shared channel in a second cell that is integrated with a first cell by carrier aggregation,
Delivery confirmation information for the downlink shared channel using the uplink control channel assigned to the predetermined frequency domain of the first cell or the uplink shared channel assigned to the frequency domain other than the predetermined frequency domain of the first cell. And the receiver that receives
A control unit that controls switching of carrier aggregation on or off based on traffic in at least one of the first cell and the second cell is provided.
When the traffic is equal to or greater than the first threshold value, the control unit switches off the carrier aggregation, deletes the second cell integrated with the first cell, and the traffic becomes the first. When it is equal to or greater than or greater than the second threshold value of 1 or more, the release of the uplink control channel resource allocated for the second cell and the release of the uplink control channel resource to the released area. Allocate the upstream shared channel
Wireless communication system comprising a call. The process of transmitting the downlink shared channel in the second cell, which is integrated with the first cell by carrier aggregation, and
Delivery confirmation information for the downlink shared channel using the uplink control channel assigned to the predetermined frequency domain of the first cell or the uplink shared channel assigned to the frequency domain other than the predetermined frequency domain of the first cell. And the process of receiving
It comprises a step of controlling the on / off switching of the carrier aggregation based on the traffic in at least one of the first cell and the second cell .
If the traffic is greater than or equal to the first threshold, the carrier aggregation is switched off, the second cell integrated with the first cell is deleted, and the traffic is greater than or equal to the first threshold. When it is equal to or larger than a certain second threshold value, the uplink control channel resource allocated for the second cell is released, and the uplink shared channel is allocated to the area where the uplink control channel resource is released. I do
Wireless communication method characterized by and this.

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