JP2020155877A - Base station and radio communication control method - Google Patents

Abstract

To improve resource allocation corresponding to a change of the amount of data retained by a terminal.SOLUTION: A base station includes: a reception unit that receives information indicating the amount of uplink data retained by a terminal from the terminal; and a control unit that assigns an uplink transmission opportunity to the terminal after detecting that the information indicates the amount of uplink data that does not require assignment of the uplink transmission opportunity.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to base stations and wireless communication control methods.

In the Universal Mobile Telecommunication System (UMTS) network, Long Term Evolution (LTE) has been specified for the purpose of higher data rate and lower latency. In addition, a successor system to LTE is also being studied for the purpose of further widening the bandwidth and increasing the speed from LTE. The successor systems to LTE include, for example, LTE-Advanced (LTE-A), Future Radio Access (FRA), 5th generation mobile communication system (5G), 5G plus (5G +), Radio Access Technology (New-RAT), and New. There is a system called Radio (NR).

3GPP TS 36.331 v15.4.0, “Radio Resource Control (RRC); Protocol specification (Release 15),” December 2018

In wireless communication, the base station may receive a notification regarding the amount of data held by the terminal and allocate resources to the terminal based on the notification.

However, there is room for consideration as to how to allocate resources according to changes in the amount of data held by the terminal.

One of the purposes of the present disclosure is to improve resource allocation according to changes in the amount of data held by the terminal.

The base station according to one aspect of the present disclosure indicates that a receiving unit that receives information indicating the amount of uplink data held by the terminal from the terminal and the information indicates the amount of uplink data for which allocation of uplink transmission opportunities is not required. After the detection, the terminal is provided with a control unit that allocates the uplink transmission opportunity.

According to the present disclosure, it is possible to improve resource allocation according to a change in the amount of data held by the terminal.

It is a sequence diagram which shows the example of the processing between a base station and a terminal. It is a block diagram which shows an example of the structure of the base station which concerns on one Embodiment. It is a block diagram which shows an example of the structure of the terminal which concerns on one Embodiment. It is a sequence diagram which shows the 1st example of the processing between a base station and a terminal which concerns on one Embodiment. It is a sequence diagram which shows the 2nd example of the processing between a base station and a terminal which concerns on one Embodiment. It is a sequence diagram which shows the 3rd example of the processing between a base station and a terminal which concerns on one Embodiment. It is a figure which shows an example of the hardware composition of the base station and the terminal which concerns on one Embodiment.

Hereinafter, embodiments according to one aspect of the present disclosure will be described with reference to the drawings.

In 3GPP, wireless communication systems for the Internet of Things (IoT) (for example, specifications of terminals (user devices: UE)) are being studied.

The base station (for example, eNodeB: eNB) manages the buffer retention amount of the uplink (UL) of the terminal based on the buffer status report (BSR) transmitted from the terminal.

The buffer retention amount may be, for example, the amount of data waiting for transmission from the terminal to the base station, in other words, the amount of uplink data held by the terminal in the buffer. The buffer retention amount changes when new data to be transmitted is generated (for example, when data to be transmitted is generated in the upper layer).

The buffer retention amount may be measured for each layer that processes uplink data. The buffer retention is, for example, the retention of Service Data Unit (SDU) in the Uplink Packet Data Convergence Protocol (PDCP) layer, the retention of SDU in the Uplink Radio Link Control (RLC) layer, and the uplink RLC layer. It may be expressed by the amount of retention of Protocol Data Unit (PDU) in.

Further, the buffer retention amount may be expressed by, for example, the transmission rate (or throughput) for each bearer. Alternatively, the upstream data retention amount of the terminal may be expressed by, for example, the transmission rate (or throughput) of the bearer of the Data Radio Bearer (DRB). Alternatively, the buffer retention amount may be expressed by the number of bearers (or the number of logical channels) above (or below) the predetermined transmission rate.

The base station allocates resources to terminals according to the amount of UL buffer retention to be managed.

However, in the BSR, since the changing buffer retention amount in the terminal cannot be immediately notified, the base station cannot appropriately allocate resources based on the buffer retention amount in the UL of the terminal. Therefore, the communication efficiency of the terminal may decrease.

For example, in the Narrow band Internet of Things (NB IoT) being considered in 3GPP, the terminal (NB IoT UE) does not have the function of sending a Scheduling Request requesting resource allocation to the base station. Therefore, when new data is generated in the terminal, the terminal executes a procedure for establishing a connection with the base station (for example, a Random Access (RA) procedure). RA procedure is a process of establishing a connection by transmitting and receiving a control signal between a terminal and a base station. Therefore, the transmission of data generated at the terminal is delayed until the connection is established, and the sequence related to the transmission / reception of the control signal is wasted.

The following describes an example of the sequence between the base station and the terminal that support NB-IoT.

FIG. 1 is a sequence diagram showing an example of processing between a base station and a terminal. FIG. 1 shows data and control information transmitted and received between the base station and the terminal, the buffer retention amount of the terminal, and the buffer retention amount of the terminal managed by the base station.

In S101, 100 bytes of data are generated at the terminal. In this case, the buffer retention amount of the terminal is updated to 100 bytes.

At S102, the terminal transmits a BSR indicating that the buffer retention amount is 100 bytes remaining to the base station. Here, the base station determines that the buffer retention amount of the terminal is 100 bytes, and updates the buffer retention amount of the managed terminal to 100 bytes.

In S103, the base station transmits a UL grant regarding resource allocation to the terminal. The UL grant indicates an opportunity to transmit data assigned to the terminal. Since the buffer retention amount of the terminal managed by the base station is 100 bytes, the UL grant of S103 allocates a resource capable of transmitting 100 bytes of data to the terminal. Further, in the UL grant, in addition to the resource capable of transmitting 100 bytes of data, a resource capable of transmitting BSR may be allocated. Further, in S103, the base station updates the buffer retention amount of the managed terminal to 0 bytes.

In S104, the terminal transmits the 100 bytes of data held in the buffer and the BSR to the base station. In S104, the terminal transmits 100 bytes of data held in the buffer, so the BSR indicates that the buffer retention amount of the terminal is 0 bytes.

In S105, 50 bytes of data are generated at the terminal. In this case, the buffer retention amount of the terminal is updated to 50 bytes.

In S106, the terminal executes a procedure (for example, Random Access (RA) procedure) for establishing a connection with the base station in order to transmit the newly generated 50 bytes of data.

As shown in S104 of FIG. 1, for example, when the terminal notifies the base station of a BSR indicating that the buffer retention amount is 0 bytes, the base station determines that the buffer retention amount of the terminal is 0 bytes. In this case, the base station determines that it is not necessary to allocate a data transmission opportunity (for example, a resource) to the terminal, and does not transmit the UL grant after S104.

However, after the notification of the BSR indicating that the buffer retention amount is 0 bytes, new data to be transmitted to the base station may occur at the terminal as in S105. In such a case, the base station cannot allocate appropriate resources until the procedure for establishing the connection with the terminal is completed as described above. Therefore, the transmission of new data generated in the terminal may be delayed.

In the present embodiment, resource allocation is performed according to a change in the amount of data held by the terminal by devising control at the base station after the notification of the BSR indicating that the buffer retention amount of the terminal is 0 bytes. Try to improve.

[Configuration of base station and terminal]
FIG. 2 is a block diagram showing an example of the configuration of the base station 10 according to the present embodiment. FIG. 3 is a block diagram showing an example of the configuration of the terminal 20 according to the present embodiment.

The base station 10 and the terminal 20 support NB-IoT communication. The terminal 20 transmits a BSR indicating the buffer retention amount of the buffer of the terminal 20 to the base station 10. The base station 10 allocates resources to the terminal 20 based on the BSR. Then, the base station 10 transmits a UL grant indicating the resources allocated to the terminal 20 to the terminal 20. The UL grant is an example of a control signal that gives an opportunity to transmit data to the terminal 20, and the amount of data that can be transmitted by the terminal 20 is set.

The base station 10 illustrated in FIG. 2 includes, for example, a transmission unit 101, a reception unit 102, and a control unit 103.

The transmission unit 101 transmits a downlink (DL) signal to the terminal 20 under the control of the control unit 103. The DL signal may include channel quality information, a control channel signal including control information, a data channel signal containing data, a reference signal, and the like. In addition, the DL signal may include a UL grant.

The receiving unit 102 receives the UL signal transmitted from the terminal 20 under the control of the control unit 103. The UL signal may include channel quality information, a control channel signal including control information, a data channel signal containing data, a reference signal, and the like. Also, the UL signal may include a BSR.

The control unit 103 controls the transmission process in the transmission unit 101 and the reception process in the reception unit 102. For example, the control unit 103 receives data, control information, and the like from the upper layer and outputs the data to the transmission unit 101. Further, the control unit 103 outputs the data and control information received from the reception unit 102 to the upper layer.

Further, for example, the control unit 103 allocates resources in communication with the terminal 20. For example, the control unit 103 manages the buffer retention amount of the terminal 20 based on the BSR. Then, the control unit 103 allocates resources according to the buffer retention amount, and outputs a UL grant indicating the resources (data transmission opportunity) allocated to the terminal 20 to the transmission unit 101.

The terminal 20 illustrated in FIG. 3 includes, for example, a receiving unit 201, a transmitting unit 202, and a control unit 203.

The receiving unit 201 receives the DL signal transmitted from the base station 10 under the control of the control unit 203.

The transmission unit 202 transmits the UL signal to the base station 10 under the control of the control unit 203.

The control unit 203 controls the reception process in the reception unit 201 and the transmission process in the transmission unit 202. For example, the control unit 203 receives data, control information, and the like from the upper layer and outputs the data to the transmission unit 202. Further, the control unit 103 outputs the data and control information received from the reception unit 201 to the upper layer.

Further, for example, the control unit 203 controls the transmission processing of data having an amount of data that can be transmitted by the terminal 20 based on the UL grant included in the DL signal. Further, for example, the control unit 203 has a buffer for storing data and the like received from the upper layer, and manages the buffer retention amount. Then, the control unit 203 outputs a BSR indicating the buffer retention amount to the transmission unit 202.

Next, the control after the base station 10 according to the present embodiment determines that the buffer retention amount of the terminal 20 is 0 bytes will be described. For example, the base station 10 determines that the buffer retention amount of the terminal 20 is 0 bytes by the notification of the BSR and / or the UL grant transmitted by the base station 10.

The base station 10 according to the present embodiment transmits a UL grant to the terminal 20 after determining that the buffer retention amount of the terminal 20 has reached 0 bytes. In the UL grant transmitted while the base station 10 determines that the buffer retention amount of the terminal 20 is 0 bytes, for example, the amount of data that the terminal 20 can transmit the BSR may be set. Further, the UL grant during this period may be transmitted a predetermined number of times, and the transmission cycle may be a constant cycle.

In the following, after the buffer retention amount of the terminal 20 becomes 0 bytes, three situations will be described according to the presence / absence of data generation in the terminal 20 and the difference in the timing of data generation.

[Situation 1]
In situation 1, data is generated in the terminal 20 immediately after the terminal 20 transmits the BSR indicating that the buffer retention amount is 0 bytes remaining to the base station 10.

FIG. 4 is a sequence diagram showing a first example of processing between the base station 10 and the terminal 20 according to the present embodiment.

FIG. 4 shows data and control information transmitted / received between the base station 10 and the terminal 20, the buffer retention amount of the terminal 20, and the buffer retention amount of the terminal 20 managed by the base station 10. .. Further, in FIG. 4, the UL grant transmitted from the base station 10 to the terminal 20 is assigned an identification number #i (i is an integer of 0 or more) indicating the order of transmission.

In S201, 100 bytes of data are generated in the terminal 20. In this case, the buffer retention amount of the terminal 20 is updated to 100 bytes.

In S202, the terminal 20 transmits a BSR indicating that the buffer retention amount is 100 bytes remaining to the base station 10. Here, the base station 10 determines that the buffer retention amount of the terminal 20 is 100 bytes, and updates the buffer retention amount of the managed terminal 20 to 100 bytes.

In S203, the base station 10 transmits UL grant # 0 regarding resource allocation to the terminal 20. Since the buffer retention amount of the terminal 20 managed by the base station 10 is 100 bytes, UL grant # 0 allocates a resource capable of transmitting 100 bytes of data to the terminal 20. Further, in UL Grant # 0, a resource capable of transmitting BSR may be allocated in addition to a resource capable of transmitting 100 bytes of data. Further, in S203, the base station 10 updates the buffer retention amount of the managed terminal 20 to 0 bytes.

In S204, the terminal 20 transmits the 100-byte data held in the buffer and the BSR to the base station 10. In S204, since the terminal 20 transmits 100 bytes of data held in the buffer, the BSR indicates that the buffer retention amount of the terminal 20 is 0 bytes.

In S205, 50 bytes of data are generated in the terminal 20. In this case, the buffer retention amount of the terminal 20 is updated to 50 bytes.

At S206, the base station 10 transmits UL grant # 1. In UL Grant # 1, a resource (for example, 2 bytes) capable of transmitting a BSR is allocated to the terminal 20. Here, in the buffer retention amount management of the base station 10, the buffer retention amount of the terminal 20 may be updated to be 2 bytes, or the determination that the buffer retention amount of the terminal 20 is 0 bytes may be maintained.

The time interval between the timing at which the base station 10 receives the data and the BSR in S204 and the transmission timing at UL Grant # 1 is, for example, Ta.

At S207, the terminal 20 transmits a BSR indicating that the buffer retention amount is 50 bytes remaining to the base station 10. Here, the base station 10 determines that the buffer retention amount of the terminal 20 is 50 bytes, and updates the buffer retention amount of the managed terminal 20 to 50 bytes.

At S208, the base station 10 transmits UL grant # 2. Since the buffer retention amount of the terminal 20 managed by the base station 10 is 50 bytes, UL Grant # 2 allocates a resource capable of transmitting 50 bytes of data to the terminal 20. Further, in UL Grant # 2, a resource capable of transmitting BSR may be allocated in addition to a resource capable of transmitting 50 bytes of data. Further, in S208, the base station 10 updates the buffer retention amount of the managed terminal 20 to 0 bytes.

The UL grant # 2 is a UL grant that is transmitted when it is determined that the buffer retention amount of the terminal 20 is not 0 bytes. The time interval between the transmission timing of UL grant # 2 and the transmission timing of UL grant # 1 may be different from Ta or the same as Ta.

In S209, the terminal 20 transmits the 50 bytes of data held in the buffer and the BSR to the base station 10. In S209, since the terminal 20 transmits 50 bytes of data held in the buffer, the BSR indicates that the buffer retention amount of the terminal 20 is 0 bytes. The base station 10 receives the BSR indicating that the buffer retention amount of the terminal 20 is 0 bytes, and updates the buffer retention amount of the managed terminal 20 to 0 bytes.

In S210, the base station 10 transmits UL grant # 3. In UL Grant # 3, a resource (for example, 2 bytes) capable of transmitting a BSR is allocated to the terminal 20. Here, in the buffer retention amount management of the base station 10, the buffer retention amount of the terminal 20 may be updated to be 2 bytes, or the determination that the buffer retention amount of the terminal 20 is 0 bytes may be maintained.

The time interval between the timing at which the base station 10 receives the data and the BSR in S209 and the transmission timing at UL Grant # 3 is Ta.

In S211 the terminal 20 transmits a BSR indicating that the buffer retention amount is 0 bytes remaining to the base station 10. For example, when the base station 10 updates that the buffer retention amount of the terminal 20 is 2 bytes (see S210), the base station 10 determines that the buffer retention amount of the terminal 20 is 0 bytes, and manages the buffer of the terminal 20. The retention amount may be updated to 0 bytes.

At S212, the base station 10 transmits UL grant # 4. In UL Grant # 4, a resource (for example, 2 bytes) capable of transmitting a BSR is allocated to the terminal 20. Here, in the buffer retention amount management of the base station 10, the buffer retention amount of the terminal 20 may be updated to be 2 bytes, or the determination that the buffer retention amount of the terminal 20 is 0 bytes may be maintained.

The time interval between the transmission timing of UL Grant # 4 and the transmission timing of UL Grant # 3 is Ta. In other words, after the base station 10 receives the data and the BSR in S209, the base station 10 determines that the buffer retention amount of the terminal 20 is 0 bytes, while the transmission cycle is UL. Grants # 3 and # 4 are transmitted.

In the sequence shown in FIG. 4, the base station 10 transmits the UL grant even when it is determined that the buffer retention amount of the terminal 20 is 0 bytes. For example, in S203 (or S204), even if the base station 10 determines that the buffer retention amount of the terminal 20 is 0 bytes, the base station 10 transmits the UL grant in S206.

When data is generated in the terminal 20 by this sequence (for example, S205), the base station 10 transmits the UL grant to the terminal 20, so that the resource allocation according to the change in the amount of data held by the terminal 20 Can be improved. Moreover, since the execution of the RA procedure is suppressed, the communication efficiency is improved.

For example, the base station 10 may control resource allocation based on the sequence shown in FIG. 4 when there is a high possibility that data will be generated at the terminal 20.

Further, in the sequence shown in FIG. 4, the shorter the Ta is set, the faster the data generated in the terminal 20 can be transmitted.

Note that FIG. 4 shows an example in which the UL grant is transmitted in one transmission cycle Ta when the base station 10 determines that the buffer retention amount of the terminal 20 is 0 bytes. Disclosure is not limited to this. The UL grant transmission cycle may be plural. For example, the base station 10 transmits the first predetermined number of UL grants in the first transmission cycle while maintaining the determination that the buffer retention amount of the terminal 20 is 0 bytes, and then the second transmission cycle. A second predetermined number of UL grants may be transmitted in the transmission cycle of.

An example in which a plurality of transmission cycles are set will be described in the following situations 2 and 3.

[Situation 2]
In situation 2, data is generated after a certain period of time has elapsed after the terminal 20 transmits the BSR indicating that the buffer retention amount is 0 bytes remaining to the base station 10.

FIG. 5 is a sequence diagram showing a second example of processing between the base station 10 and the terminal 20 according to the present embodiment.

5 shows the data and control information transmitted / received between the base station 10 and the terminal 20, the buffer retention amount of the terminal 20, and the buffer retention amount of the terminal 20 managed by the base station 10, as in FIG. Is shown. Further, in FIG. 5, the UL grant transmitted from the base station 10 to the terminal 20 is assigned an identification number #i (i is an integer of 0 or more) indicating the order of transmission.

The UL grants having the same identification number between FIGS. 4 and 5 do not have to be the same UL grants. For example, UL grants with the same identification number between FIGS. 4 and 5 may exhibit different resource allocations or may be transmitted at different time intervals.

In FIG. 5, the same processing as in FIG. 4 may be given the same number and the description thereof may be omitted. The difference between FIGS. 4 and 5 is that in FIG. 4, data is generated after S204 (S205 in FIG. 4), whereas in FIG. 5, it takes longer to generate data than in FIG. It is a point.

At S301, the base station 10 transmits UL grant # 1. In UL Grant # 1, a resource (for example, 2 bytes) capable of transmitting a BSR is allocated to the terminal 20. Here, in the buffer retention amount management of the base station 10, the buffer retention amount of the terminal 20 may be updated to be 2 bytes, or the determination that the buffer retention amount of the terminal 20 is 0 bytes may be maintained.

At S302, the terminal 20 transmits a BSR indicating that the buffer retention amount is 0 bytes remaining to the base station 10. For example, when the base station 10 updates that the buffer retention amount of the terminal 20 is 2 bytes (see S301), the base station 10 determines that the buffer retention amount of the terminal 20 is 0 bytes and manages it. The buffer retention amount of the terminal 20 may be updated to 0 bytes.

Since S303 and S304 are the same processes as S301 and S302, respectively, the description thereof will be omitted. Further, since S305 and S306 are the same processes as S301 and S302, respectively, the description thereof will be omitted.

The time interval between the transmission timing of UL grant # 2 and the transmission timing of UL grant # 1 is Ta. The time interval between the transmission timing of UL grant # 3 and the transmission timing of UL grant # 2 is Ta. In other words, after the base station 10 receives the data and the BSR in S204, the base station 10 determines that the buffer retention amount of the terminal 20 is 0 bytes, while the transmission cycle Ta is 3 The UL grant (UL grant # 1 to UL grant # 3) of the times is transmitted.

At S307, the base station 10 transmits UL grant # 4. In UL Grant # 4, a resource (for example, 2 bytes) capable of transmitting a BSR is allocated to the terminal 20. Here, in the buffer retention amount management of the base station 10, the buffer retention amount of the terminal 20 may be updated to be 2 bytes, or the determination that the buffer retention amount of the terminal 20 is 0 bytes may be maintained.

The base station 10 transmits the UL grant three times in the transmission cycle Ta, and then changes the transmission cycle from Ta to Tb. Therefore, in S307, the time between the transmission timing of UL Grant # 4 and the transmission timing of UL Grant # 3 to be transmitted when the base station 10 determines that the buffer retention amount of the terminal 20 is 0 bytes. The interval is Tb.

At S308, the terminal 20 transmits a BSR indicating that the buffer retention amount is 0 bytes remaining to the base station 10. For example, when the buffer retention amount of the terminal 20 is updated to be 2 bytes (see S307), the base station 10 determines that the buffer retention amount of the terminal 20 is 0 bytes, and manages the buffer of the terminal 20. The retention amount may be updated to 0 bytes.

In S309, 50 bytes of data are generated in the terminal 20. In this case, the buffer retention amount of the terminal 20 is updated to 50 bytes.

At S310, the base station 10 transmits UL grant # 5. In UL Grant # 5, a resource (for example, 2 bytes) capable of transmitting a BSR is allocated to the terminal 20. Here, in the buffer retention amount management of the base station 10, the buffer retention amount of the terminal 20 may be updated to be 2 bytes, or the determination that the buffer retention amount of the terminal 20 is 0 bytes may be maintained.

The time interval between the transmission timing of UL grant # 5 and the transmission timing of UL grant # 4 is Tb.

In S311 the terminal 20 transmits a BSR indicating that the buffer retention amount is 50 bytes remaining to the base station 10. Here, the base station 10 determines that the buffer retention amount of the terminal 20 is 50 bytes, and updates the buffer retention amount of the managed terminal 20 to 50 bytes. Further, since the base station 10 has received the BSR indicating that the buffer retention amount is not 0 bytes remaining, the history of the UL grant transmission cycle and the number of transmissions may be reset.

At S312, the base station 10 transmits UL grant # 6. Since the buffer retention amount of the terminal 20 managed by the base station 10 is 50 bytes, UL Grant # 6 allocates a resource capable of transmitting 50 bytes of data to the terminal 20. Further, in UL Grant # 6, a resource capable of transmitting BSR may be allocated. Further, in S312, the base station 10 updates the buffer retention amount of the managed terminal 20 to 0 bytes.

In S313, the terminal 20 transmits the 50-byte data held in the buffer and the BSR to the base station 10. In S313, the terminal 20 transmits 50 bytes of data held in the buffer, so the BSR indicates that the buffer retention amount of the terminal 20 is 0 bytes. The base station 10 receives the BSR indicating that the buffer retention amount of the terminal 20 is 0 bytes, and updates the buffer retention amount of the managed terminal 20 to 0 bytes.

At S314, the base station 10 transmits UL grant # 7. In the UL grant in S314, a resource (for example, 2 bytes) capable of transmitting a BSR is allocated to the terminal 20. Here, in the buffer retention amount management of the base station 10, the buffer retention amount of the terminal 20 may be updated to be 2 bytes, or the determination that the buffer retention amount of the terminal 20 is 0 bytes may be maintained.

Since the base station 10 received the BSR indicating that the buffer retention amount is not 0 bytes remaining in S311, the UL grant transmission cycle and the history of the number of transmissions are reset, and the transmission cycle is set to the initial value (for example,). , Ta). Therefore, the time interval between the timing at which the base station 10 receives the data and the BSR in S314 and the transmission timing of the UL grant # 7 is Ta.

In the sequence shown in FIG. 5, the base station 10 transmits the UL grant even when it is determined that the buffer retention amount of the terminal 20 is 0 bytes. By this sequence, when data is generated in the terminal 20, the base station 10 transmits the UL grant to the terminal 20, so that the resource allocation can be improved according to the change in the amount of data held by the terminal 20. Can be done. Moreover, since the execution of the RA procedure is suppressed, the communication efficiency is improved.

Further, in the sequence shown in FIG. 5, two transmission cycles, a transmission cycle Ta and a transmission cycle Tb, are set. By setting this transmission cycle, it is possible to reduce the number of UL grant transmissions and achieve both communication efficiency.

For example, the transmission cycle Tb is set longer than the transmission cycle Ta. With this setting, the base station 10 sets the UL grant transmission cycle longer after transmitting the UL grant a predetermined number of times in a state where the buffer retention amount of the terminal 20 is determined to be 0 bytes. With this setting, the number of UL grant transmissions can be reduced. Further, since the transmission of the UL grant is not stopped in the state where the transmission cycle is set to be long, the execution of the RA procedure is suppressed and the communication efficiency can be improved.

The setting of the transmission cycle Tb and the transmission cycle Ta is not limited. The transmission cycle Tb may be set shorter than the transmission cycle Ta. For example, when the probability of data generation in the terminal 20 increases with the passage of time, the transmission cycle of the UL grant can be shortened with the passage of time, so that the communication efficiency can be improved.

[Situation 3]
In situation 3, no data is generated after the terminal 20 transmits a BSR indicating that the buffer retention amount is 0 bytes remaining to the base station 10.

FIG. 6 is a sequence diagram showing a third example of processing between the base station 10 and the terminal 20 according to the present embodiment.

FIG. 6 shows data and control information transmitted / received between the base station 10 and the terminal 20, the buffer retention amount of the terminal 20, and the buffer retention amount of the terminal 20 managed by the base station 10, as in FIG. Is shown. Further, in FIG. 6, the UL grant transmitted from the base station 10 to the terminal 20 is assigned an identification number #i (i is an integer of 0 or more) indicating the order of transmission.

The UL grants having the same identification number in FIGS. 4, 5 and 6 do not have to be the same UL grants. For example, UL grants with the same identification number between FIGS. 4, 5 and 6 may exhibit different resource allocations or may be transmitted at different time intervals.

Further, in FIG. 6, the same processing as in FIGS. 4 and 5 may be assigned the same number and the description thereof may be omitted. The difference between FIGS. 5 and 6 is that in FIG. 5, data is generated after S308 (S309 in FIG. 5), whereas in FIG. 6, data is not generated.

In S308, the terminal 20 transmits a BSR indicating that the buffer retention amount is 0 bytes remaining to the base station 10, and then in S310, the base station 10 transmits UL grant # 5. In UL Grant # 5, a resource (for example, 2 bytes) capable of transmitting a BSR is allocated to the terminal 20. Here, in the buffer retention amount management of the base station 10, the buffer retention amount of the terminal 20 may be updated to be 2 bytes, or the determination that the buffer retention amount of the terminal 20 is 0 bytes may be maintained.

In S401, the terminal 20 transmits a BSR indicating that the buffer retention amount is 0 bytes remaining to the base station 10. For example, when the buffer retention amount of the terminal 20 is updated to be 2 bytes (see S310), the base station 10 determines that the buffer retention amount of the terminal 20 is 0 bytes, and manages the buffer of the terminal 20. The retention amount may be updated to 0 bytes.

At S402, the base station 10 transmits UL grant # 6. In UL Grant # 6, a resource (for example, 2 bytes) capable of transmitting a BSR is allocated to the terminal 20. Here, in the buffer retention amount management of the base station 10, the buffer retention amount of the terminal 20 may be updated to be 2 bytes, or the determination that the buffer retention amount of the terminal 20 is 0 bytes may be maintained.

The time interval between the transmission timing of UL grant # 6 and the transmission timing of UL grant # 5 is Tb. In other words, after transmitting UL Grant # 3, the base station 10 transmits UL Grants (UL Grants # 4 to UL Grants # 6) three times in the transmission cycle Tb.

In S403, the terminal 20 transmits a BSR indicating that the buffer retention amount is 0 bytes remaining to the base station 10. For example, when the buffer retention amount of the terminal 20 is updated to be 2 bytes (see S402), the base station 10 determines that the buffer retention amount of the terminal 20 is 0 bytes, and manages the buffer of the terminal 20. The retention amount may be updated to 0 bytes.

In S404, the base station 10 transmits the UL grant three times in the transmission cycle Tb, and then receives a BSR indicating that the buffer retention amount is 0 bytes remaining from the terminal 20, which triggers the UL grant. Stop sending.

In the sequence shown in FIG. 6, the base station 10 transmits the UL grant even when it is determined that the buffer retention amount of the terminal 20 is 0 bytes. Further, in the sequence shown in FIG. 6, two transmission cycles, a transmission cycle Ta and a transmission cycle Tb, are set. By setting this transmission cycle, it is possible to reduce the number of UL grant transmissions and achieve both communication efficiency.

For example, the transmission cycle Tb may be set longer than the transmission cycle Ta or shorter than the transmission cycle Ta.

Further, in the sequence shown in FIG. 6, after the UL grant is transmitted a predetermined number of times (three times in FIG. 6) in the transmission cycle Tb, there is no change in the state where the buffer retention amount of the terminal 20 is 0 bytes. Stop sending UL grants. By stopping the transmission according to the number of transmissions of the UL grant, it is possible to avoid extra transmission of the UL grant, and it is possible to achieve both reduction in the number of transmissions of the UL grant and communication efficiency.

Note that FIG. 6 shows an example in which three UL grants are transmitted in the transmission cycle Ta and three UL grants are transmitted in the transmission cycle Tb, but the number of transmission cycles and each transmission cycle are set. The number of UL grants transmitted is not limited to these.

Note that FIGS. 4, 5 and 6 show an example in which UL grants are transmitted in a fixed transmission cycle (for example, transmission cycles Ta and Tb), but the present disclosure is not limited to this. For example, UL grant transmission intervals may differ from each other. For example, the UL grant may be transmitted at a gradually longer transmission interval as the number of transmissions of the UL grant increases, or may be transmitted at a gradually shorter transmission interval as the number of transmissions of the UL grant increases. May be good.

Further, in FIGS. 4, 5 and 6, the UL grant transmitted by the base station 10 when it is determined that the buffer retention amount of the terminal 20 is 0 bytes can transmit the BSR to the terminal 20. An example is shown in which various resources are allocated. The present disclosure is not limited to this. When it is determined that the buffer retention amount of the terminal 20 is 0 bytes, the UL grant transmitted by the base station 10 may allocate a resource capable of transmitting a predetermined amount of data. For example, the base station 10 may gradually reduce the resources allocated as the number of transmissions of the UL grant increases, or may gradually increase the resources allocated as the number of transmissions of the UL grant increases.

Further, FIGS. 4, 5 and 6 show an example in which the transmission control of the UL grant is changed depending on whether or not the buffer retention amount of the terminal 20 is zero, but the present disclosure is not limited to this. .. "The buffer retention amount of the terminal 20 is zero" corresponds to an example of "a transmission opportunity (for example, a resource) is not required (unnecessary) for the terminal 20". For example, "the transmission opportunity (for example, resource) is not required (unnecessary) for the terminal 20" may correspond to "the buffer retention amount of the terminal 20 is equal to or less than the threshold value". In this case, the base station 10 may change the transmission control of the UL grant depending on whether or not the buffer retention amount of the terminal 20 is equal to or less than the threshold value.

The receiving unit 102 of the base station 10 according to the present embodiment described above receives information (for example, BSR) indicating the amount of uplink data (for example, the buffer retention amount) held by the terminal 20 from the terminal 20. The control unit 103 allocates the uplink transmission opportunity to the terminal 20 after detecting that the information indicates the amount of uplink data for which the UL transmission opportunity allocation is not required.

By this control, when data is generated in the terminal 20, the base station 10 is allocated a transmission opportunity (for example, a resource) for data transmission, and therefore responds to a change in the amount of data held by the terminal 20. You can improve resource allocation. Therefore, the communication efficiency is improved without delaying the transmission of the data generated in the terminal 20.

For example, in NB-IoT, the terminal does not have a function to send a Scheduling Request to the base station. Therefore, the terminal executes a procedure for establishing a connection with the base station when new data to be transmitted to the base station occurs at the terminal after the notification of the BSR indicating that the buffer retention amount is 0 bytes. Will be done. According to the present embodiment, when new data to be transmitted to the base station is generated in the terminal after the notification of the BSR indicating that the buffer retention amount is 0 bytes, the connection with the base station is established. You can avoid the procedure for.

Further, according to the present embodiment, the base station 10 determines that the buffer retention amount of the terminal 20 is 0, and then the data amount to be allocated to the terminal 20 is notified by the BSR (for example, 2 bytes). Set to. By setting this amount of data, it is possible to avoid allocating unnecessary resources to the terminal 20.

The amount of data allocated to the terminal 20 after it is determined that the buffer retention amount of the terminal 20 is 0 is not limited to the above-mentioned example. For example, the data amount of the transmission opportunity allocated to the terminal 20 after the buffer retention amount of the terminal 20 is determined to be 0 is the transmission opportunity data allocated to the terminal 20 when the buffer retention amount of the terminal 20 is not 0. It may be less than the amount.

In the above-described embodiment, an example in which the base station 10 and the terminal 20 support NB-IoT communication is shown, but the present disclosure is not limited to this. For example, the present disclosure may also be applied to a base station 10 and a terminal 20 that support a wireless communication system different from NB-IoT. For example, it may be applied to a base station 10 and a terminal 20 that support LTE communication.

(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.

Functions include judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, selection, establishment, comparison, assumption, expectation, and assumption. There are broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, assigning, etc., but only these. I can't. For example, a functional block (constituent unit) for functioning transmission is called a transmitting unit or a transmitter. As described above, the method of realizing each of them is not particularly limited.

For example, the base station, terminal, or 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. 7 is a diagram showing an example of the hardware configuration of the base station and the terminal according to the embodiment of the present disclosure. The base station 10 and the 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 the following description, the word "device" can be read as a circuit, a device, a unit, or the like. The hardware configuration of the base station 10 and the 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 each function of the base station 10 and the terminal 20, the processor 1001 performs an operation by loading predetermined software (program) on the hardware such as the processor 1001 and the memory 1002, and controls the communication by 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 a peripheral device, a control device, an arithmetic unit, a register, and the like. For example, the above-mentioned control unit 103, control unit 203, 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 103 of the base station 10 or the control unit 203 of the terminal 20 may be realized by a control program stored in the memory 1002 and operating in the processor 1001, or may be realized in the same manner for other functional blocks. Good. Although the above-mentioned various processes have been described as being executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. Processor 1001 may be implemented by one or more chips. The program may be transmitted from the network via a telecommunication line.

The memory 1002 is a computer-readable recording medium, and is composed of at least one such as a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EPROM (Electrically Erasable Programmable ROM), and a RAM (Random Access Memory). May be done. 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, and is, for example, an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (for example, a compact disk, a digital versatile disk, or a Blu-ray). It may consist of at least one (registered trademark) disk), smart card, flash memory (eg, card, stick, key drive), floppy (registered trademark) disk, magnetic strip, and the like. The storage 1003 may be referred to as an auxiliary storage device. The storage medium described above may be, for example, a database, server or other suitable medium containing at least one of memory 1002 and storage 1003.

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. Communication device 1004 includes, for example, a high frequency switch, a duplexer, a filter, a frequency synthesizer, and the like in order to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). It may be composed of. For example, the transmission unit 101, the reception unit 102, the reception unit 201, the transmission unit 202, and the like described above may be realized by the communication device 1004.

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, an LED lamp, etc.) that outputs 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 terminal 20 are hardware such as a microprocessor, a digital signal processor (DSP: Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), and an FPGA (Field Programmable Gate Array). It may be configured to include, and a part or all of each functional block may be realized by the hardware. For example, processor 1001 may be implemented using at least one of these hardware.

(Information notification, signaling)
Notification of information is not limited to the embodiments / embodiments described in the present disclosure, and may be performed by other methods. For example, information notification includes physical layer signaling (for example, DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (for example, RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, etc. It may be carried out by notification information (MIB (Master Information Block), SIB (System Information Block)), other signals, or a combination thereof. 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.

(Applicable system)
Each aspect / embodiment described in the present disclosure includes LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), and 5G (5th generation mobile communication). system), FRA (Future Radio Access), NR (New Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)) )), IEEE 802.16 (WiMAX®), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth®, and other systems that utilize and extend based on these. It may be applied to at least one of the next generation systems. Further, a plurality of systems may be applied in combination (for example, a combination of at least one of LTE and LTE-A and 5G).

(Processing procedure, etc.)
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.

(Operation of base station)
In some cases, the specific operation performed by the base station in the present disclosure may be performed by its upper node. In a network consisting of one or more network nodes having a base station, various operations performed for communication with a terminal are performed by the base station and other network nodes other than the base station (eg, MME or). It is clear that it can be done by at least one of (but not limited to, S-GW, etc.). Although the case where there is one network node other than the base station is illustrated above, it may be a combination of a plurality of other network nodes (for example, MME and S-GW).

(Input / output direction)
Information and the like (* see the item "Information, signal") can be output from the upper layer (or lower layer) to the lower layer (or upper layer). Input / output may be performed via a plurality of network nodes.

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

(Judgment method)
The determination may be made by a value represented by 1 bit (0 or 1), by a boolean value (Boolean: true or false), or by comparing numerical values (for example, a predetermined value). It may be done by comparison with the value).

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

Further, software, instructions, information and the like may be transmitted and received via a transmission medium. For example, a website, where 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.). 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.

(Information, signal)
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 may be voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of these. It may be represented by a combination of.

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, at least one of a channel and a symbol may be a signal (signaling). Also, the signal may be a message. Further, the component carrier (CC: Component Carrier) may be referred to as a carrier frequency, a cell, a frequency carrier, or the like.

("System", "Network")
The terms "system" and "network" used in this disclosure are used interchangeably.

(Parameter, channel name)
Further, 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, the radio resource may be indexed.

The names used for the above parameters 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 (eg, 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 in any respect limited names. is not.

(Base station (wireless base station))
In the present disclosure, "Base Station (BS)", "Wireless Base Station", "Fixed Station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", ""Accesspoint","transmissionpoint","receptionpoint","transmission / reception point", "cell", "sector", "cell group", "cell group" Terms such as "carrier" and "component carrier" 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 (RRH:)). Communication services can also be provided by Remote Radio Head). The term "cell" or "sector" is used in this coverage as part or all of the coverage area of at least one of the base station and base station subsystem providing communication services. Point to.

(Terminal)
In the present disclosure, terms such as "mobile station (MS)", "user terminal", "user equipment (UE)", and "terminal" may be used interchangeably. ..

Mobile stations can be 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, depending on the trader. It may also be referred to as a terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable term.

(Base station / Mobile station)
At least one of the base station and the mobile station may be referred to as a transmitting device, a receiving device, a 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 IoT (Internet of Things) device such as a sensor.

Further, the base station in the present disclosure may be read by the user terminal. For example, communication between a base station and a user terminal has been replaced with communication between a plurality of user terminals (for example, it may be called D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). Each aspect / embodiment of the present disclosure may be applied to the configuration. In this case, the 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 communication between terminals (for example, "side"). For example, the uplink, downlink, and the like may be read as side channels.

Similarly, the 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 terminal 20 described above.

(Meaning and interpretation of terms)
The terms "determining" and "determining" used in this disclosure may include a wide variety of actions. "Judgment" and "decision" are, for example, judgment, calculation, computing, processing, deriving, investigating, looking up, search, inquiry. It may include (eg, searching in a table, database or another data structure), ascertaining as "judgment" or "decision". Also, "judgment" and "decision" are receiving (for example, receiving information), transmitting (for example, transmitting information), input (input), output (output), and access. (Accessing) (for example, accessing data in memory) may be regarded as "judgment" or "decision". In addition, "judgment" and "decision" mean that "resolving", "selecting", "choosing", "establishing", "comparing", etc. are regarded as "judgment" and "decision". Can include. That is, "judgment" and "decision" may include that some action is regarded as "judgment" and "decision". Further, "judgment (decision)" may be read as "assuming", "expecting", "considering" and the like.

The terms "connected", "coupled", or any variation thereof, mean any direct or indirect connection or connection between two or more elements, and each other. It can include the presence of one or more intermediate elements between two "connected" or "combined" elements. The connection or connection between the elements may be physical, logical, or a combination thereof. For example, "connection" may be read as "access". As used in the present disclosure, the two elements use at least one of one or more wires, cables and printed electrical connections, and, as some non-limiting and non-comprehensive examples, the radio frequency domain. , Electromagnetic energy having wavelengths in the microwave and light (both visible and invisible) regions, etc., can be considered to be "connected" or "coupled" to each other.

The reference signal may also be abbreviated as RS (Reference Signal) and may be referred to as a pilot (Pilot) depending on the applied standard.

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", etc. 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 "part" in the configuration of each of the above devices may be replaced with a "means", a "circuit", a "device" and the like.

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.

The radio frame may be composed of one or more frames in the time domain.
Each one or more frames in the time domain may be referred to as a subframe. Subframes may further consist of one or more slots in the time domain. The subframe may have a fixed time length (eg, 1 ms) that does not depend on numerology.

The numerology may be a communication parameter that applies to at least one of the 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, radio frame configuration, transmission / reception. At least one of a specific filtering process performed by the machine in the frequency domain, a specific windowing process performed by the transmitter / receiver in the time domain, and the like may be indicated.

The slot may be composed of one or more symbols (OFDMA (Orthogonal Frequency Division Multiplexing) symbol, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbol, etc.) in the time domain. Slots may be unit of time 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. Further, the mini slot may be called 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 (or PUSCH) mapping type A. The PDSCH (or PUSCH) transmitted using the minislot may be referred to as PDSCH (or PUSCH) mapping type B.

Radio frames, subframes, slots, mini slots and symbols all represent time units for transmitting signals. The radio frame, subframe, slot, minislot and symbol may have different names corresponding to each.

For example, one subframe may be called a Transmission Time Interval (TTI), a plurality of consecutive subframes may be called a TTI, and one slot or one minislot may be called a TTI. You may. 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 mini slot is called TTI, one or more TTIs (that is, one or more slots or one or more mini slots) 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 LTE 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 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 time domain of the RB may also include one or more symbols and may be one slot, one mini slot, one subframe, or one TTI length. Each 1TTI, 1 subframe, etc. may be composed of one or a plurality of resource blocks.

In addition, one or more RBs include a physical resource block (PRB: Physical RB), a sub-carrier group (SCG: Sub-Carrier Group), a resource element group (REG: Resource Element Group), a PRB pair, an RB pair, and the like. May be called.

Further, the resource block may be composed of one or a plurality of resource elements (RE: Resource Element). 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.) may represent a subset of consecutive common resource blocks (RBs) for a neurology in a carrier. Good. Here, the common RB may be specified by an 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 a BWP for UL (UL BWP) and a BWP for DL (DL BWP). 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 wireless frames, subframes, slots, mini-slots and symbols 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, the number of symbols in the TTI, the symbol length, the cyclic prefix (CP) length, and the like can be variously changed.

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

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".

(Variations of modes, etc.)
Each aspect / embodiment described in the present disclosure may be used alone, in combination, or switched with execution. Further, the notification of predetermined information (for example, the notification of "being X") is not limited to the explicit notification, but is performed implicitly (for example, the notification of the predetermined information is not performed). May be good.

Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented as an amendment or modification without departing from the purpose and scope of the present disclosure, which is determined by the description of the scope of claims. Therefore, the description of this disclosure is for purposes of illustration only and does not have any restrictive meaning to this disclosure.

One aspect of the present disclosure is useful for wireless communication systems.

10 Base station 20 Terminals 101, 202 Transmitter 102, 201 Receiver 103,203 Control 1001 Processor 1002 Memory 1003 Storage 1004 Communication device 1005 Input device 1006 Output device 1007 Bus

Claims (6)

A receiver that receives information indicating the amount of uplink data held by the terminal from the terminal, and
After detecting that the information indicates the amount of uplink data for which the allocation of the uplink transmission opportunity is not required, the control unit that allocates the uplink transmission opportunity to the terminal, and the control unit.
Base station with. The control unit allocates the uplink transmission opportunity to the terminal in the first cycle.
The base station according to claim 1. When the control unit does not receive the information indicating the amount of uplink data larger than the threshold value the first number of times, the control unit performs the uplink with respect to the terminal in a second cycle longer than the first cycle. Assign transmission opportunities,
The base station according to claim 2. When the control unit does not receive the information indicating the amount of uplink data larger than the threshold value a second number of times greater than the first number of times, the control unit stops allocating the uplink transmission opportunity to the terminal. ,
The base station according to claim 3. After detecting that the information indicates the amount of uplink data for which the allocation of the uplink transmission opportunity is not required, the control unit determines the amount of uplink data of the uplink transmission opportunity to be allocated to the terminal, and the information transmits the uplink data. Set it smaller than when it detects that the opportunity allocation indicates the required amount of uplink data,
The base station according to claim 1. Information indicating the amount of uplink data held by the terminal is received from the terminal, and
After detecting that the information indicates an amount of uplink data for which allocation of uplink transmission opportunities is not required, the terminal is assigned the uplink transmission opportunity.
Wireless communication control method.

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