Base station device, terminal station device, wireless communication system, and wireless communication method

Abstract

To improve efficiency of data communication in an RRC inactive mode. To solve this problem, a terminal station device (200) has: a communication section (210) capable of performing communication when a base station device (100) as a communication partner is in a prescribed state; and a control section (220) that, for a setting related to a region that decodes a control signal for performing communication from the base station device (100) and an interval in which the region becomes valid, sets an interval corresponding to a first communication in the communication and an interval corresponding to a second communication, and performs control to intermittently use each interval to perform the communication according to a state of performance of data communication.

Description

TECHNICAL FIELD

[0001] The present application relates to a base station device, a terminal station device, a wireless communication system, and a wireless communication method. BACKGROUND

[0002] In the current network, services of mobile terminals (smartphones, feature phones) occupy a large portion of resources of the network. In addition, services used by mobile terminals are also likely to expand in the future.

[0003] On the other hand, it is required to cope with services having various requirements in conjunction with the development of IoT (Internet of Things) services (for example, a transportation system, a smart meter, a device, and the like monitoring system). Therefore, in the communication standard of the fifth generation mobile communication (5G or NR (New Radio)), in addition to the standard technology of 4G (fourth generation mobile communication) (for example, Non-Patent Literatures 1 to 13), it is required to achieve higher data rate, large capacity, and low latency technology.

[0004] In addition, regarding the fifth generation communication standard, technical studies are conducted in the working group meetings (for example, TSG-RAN WG1, TSG-RAN WG2, and the like) of 3GPP (Third Generation Partnership Project).

[0005] However, in general, in a wireless communication system, processing of an RRC (Radio Resource Control) layer is performed. In the processing of the RRC layer, for example, setting, changing, releasing, and the like of connection between a base station device and a terminal station device are performed. For example, in LTE (Long Term Evolution) or LTE-A (LTE-Advanced) which is a standard technology of 4G, as a state of the RRC layer, RRC connected mode (RRC_CONNECTED) and RRC idle mode (RRC_IDLE) are defined. The RRC connected mode is, for example, a mode in which data communication can be performed between a base station device and a terminal station device. The RRC idle mode is, for example, a mode in which data communication is not performed between a base station device and a terminal station device, and is a mode in which a terminal station device becomes a power saving state.

[0006] In 5G, in addition to the RRC connected mode and the RRC idle mode, the RRC inactive mode (RRC_INACTIVE) is being studied for introduction. The RRC inactive mode is a low power consumption mode equivalent to the RRC idle mode, and is a mode in which the RRC connected mode can be quickly shifted to when data transmission is to be performed. In the RRC inactive mode, information related to data communication with the terminal station device is held in the base station device. The information related to data communication includes information such as the location, communication capability, various parameters, and identifier (terminal ID) of the terminal station device. In this way, since the information related to data communication is held in the base station device, even in the RRC inactive mode, the terminal station device is considered to be connected from the core network to the base station device. As a result, when the terminal station device recovers from the RRC inactive mode to the RRC connected mode, transmission and reception of signals between the base station device and the core network is omitted, and quick shift to the RRC connected mode is achieved.

[0007] Prior Art Documents

[0008] Non-Patent Literature

[0009] Non-Patent Literature 1: 3GPP TS 36.133 V16.6.0 (2020-06)

[0010] Non-Patent Literature 2: 3GPP TS 36.211 V16.2.0 (2020-06)

[0011] Non-Patent Literature 3: 3GPP TS 36.212 V16.2.0 (2020-06)

[0012] Non-Patent Literature 4: 3GPP TS 36.213 V16.2.0 (2020-06)

[0013] Non-Patent Literature 5: 3GPP TS 36.214 V16.1.0 (2020-06)

[0014] Non-Patent Literature 6: 3GPP TS 36.300 V16.2.0 (2020-07)

[0015] Non-Patent Literature 7: 3GPP TS 36.321 V16.1.0 (2020-07)

[0016] Non-Patent Literature 8: 3GPP TS 36.322 V16.0.0 (2020-07)

[0017] Non-Patent Literature 9: 3GPP TS 36.323 V16.1.0 (2020-07)

[0018] Non-Patent Literature 10: 3GPP TS 36.331 V16.1.1 (2020-07)

[0019] Non-Patent Literature 11: 3GPP TS 36.413 V16.2.0 (2020-07)

[0020] Non-Patent Literature 12: 3GPP TS 36.423 V16.2.0 (2020-07)

[0021] Non-Patent Literature 13: 3GPP TS 36.425 V16.0.0 (2020-07)

[0022] Non-Patent Literature 14: 3GPP TS 37.324 V16.1.0 (2020-07)

[0023] Non-Patent Literature 15: 3GPP TS 37.340 V16.2.0 (2020-07)

[0024] Non-Patent Literature 16: 3GPP TS 38.201 V16.0.0 (2019-12)

[0025] Non-Patent Literature 17: 3GPP TS 38.202 V16.1.0 (2020-06)

[0026] Non-Patent Literature 18: 3GPP TS 38.211 V16.2.0 (2020-06)

[0027] Non-Patent Literature 19: 3GPP TS 38.212 V16.2.0 (2020-06)

[0028] Non-Patent Literature 20: 3GPP TS 38.213 V16.2.0 (2020-06)

[0029] Non-Patent Literature 21: 3GPP TS 38.214 V16.2.0 (2020-06)

[0030] Non-Patent Literature 22: 3GPP TS 38.215 V16.2.0 (2020-06)

[0031] Non-Patent Literature 23: 3GPP TS 38.300 V16.2.0 (2020-07)

[0032] Non-Patent Literature 24: 3GPP TS 38.321 V16.1.0 (2020-07)

[0033] Non-Patent Literature 25: 3GPP TS 38.322 V16.1.0 (2020-07)

[0034] Non-Patent Literature 26: 3GPP TS 38.323 V16.1.0 (2020-07)

[0035] Non-Patent Literature 27: 3GPP TS 38.331 V16.1.0 (2020-07)

[0036] Non-Patent Literature 28: 3GPP TS 38.401 V16.2.0 (2020-07)

[0037] Non-Patent Literature 29: 3GPP TS 38.410 V16.2.0 (2020-07)

[0038] Non-Patent Literature 30: 3GPP TS 38.413 V16.2.0 (2020-07)

[0039] Non-Patent Literature 31: 3GPP TS 38.420 V16.0.0 (2020-07)

[0040] Non-Patent Literature 32: 3GPP TS 38.423 V16.2.0 (2020-07)

[0041] Non-Patent Literature 33: 3GPP TS 38.470 V16.2.0 (2020-07)

[0042] Non-Patent Literature 34: 3GPP TS 38.473 V16.2.0 (2020-07)

[0043] Non-Patent Literature 35: 3GPP TR 38.801 V14.0.0 (2017-03)

[0044] Non-Patent Literature 36: 3GPP TR 38.802 V14.2.0 (2017-09)

[0045] Non-Patent Literature 37: 3GPP TR 38.803 V14.2.0 (2017-09)

[0046] Non-Patent Literature 38: 3GPP TR 38.804 V14.0.0 (2017-03)

[0047] Non-Patent Literature 39: 3GPP TR 38.900 V15.0.0 (2018-06)

[0048] Non-Patent Literature 40: 3GPP TR 38.912 V15.0.0 (2018-06)

[0049] Non-Patent Literature 41: 3GPP TR 38.913 V15.0.0 (2018-06) SUMMARY

[0050] PROBLEMS TO BE SOLVED BY THE INVENTION

[0051] The RRC inactive mode is a mode in which no data communication other than data communication necessary for implementation or maintenance of communication is implemented between the base station device and the terminal station device, but recently, transmission of data (e.g., small data) in the RRC inactive mode is being studied. That is, it is considered that small data such as failure information of the terminal station device, a measurement value of a sensor, and the like is transmitted from the terminal station device to the base station device in the RRC inactive mode.

[0052] It is being studied that any of a RACH method using random access and a CG (Configured Grant) method using a wireless resource set in advance is used in transmission of small data. In the RACH method, the terminal station device transmits a message containing a preamble and the like to the base station device as with random access at the time of establishing synchronization with the base station device, but transmits in one of these messages containing small data. On the other hand, in the CG method, the terminal station device transmits small data using a wireless resource set in advance in a case where the wireless resource used in transmission is set in advance from the base station device and small data is generated.

[0053] However, in data communication in the RRC inactive mode, there is a problem that the efficiency of control is poor. That is, in the RRC inactive mode, the terminal station device becomes a power saving state by cutting off power supply to the wireless communication section except for an essential case, but for example, with transmission of small data, switching of presence or absence of power supply for a short time occurs.

[0054] For example, in a case where small data is transmitted from the terminal station device in the RRC inactive mode, the terminal station device turns on power supply to the wireless reception circuit in order to receive a control channel (e.g., PDCCH (Physical Downlink Control CHannel)) that controls retransmission corresponding to the small data. In addition, for example, power supply to the wireless reception circuit is turned on in order to receive an ACK of TCP (Transmission Control Protocol), a Status Report of the RLC (Radio Link Control) layer, and the like. Furthermore, in the RRC inactive mode, the terminal station device receives a periodic paging signal through a paging frame and confirms the presence or absence of data on the downlink from the base station device.

[0055] Thus, in the RRC inactive mode in which the power supply to the wireless reception circuit is turned off, the power supply to the wireless reception circuit is frequently turned on, the switching between on and off in a short time occurs, and the efficiency of the control is reduced.

[0056] The disclosed technology is achieved in view of this point, and aims to provide a base station device, a terminal station device, a wireless communication system, and a wireless communication method capable of improving the efficiency of data communication in an RRC inactive mode.

[0057] Means for solving the problem

[0058] The base station device disclosed in the present application, in one mode, has: a communication section capable of performing communication when a terminal station device as a communication partner is in a prescribed state; and a control section that, with respect to a setting related to a region in which a control signal for performing communication with the terminal station device is decoded and an interval in which the region becomes valid, sets an interval corresponding to a first communication in the communication and an interval corresponding to a second communication, and is capable of performing control that causes the terminal station device to intermittently use each interval to perform the communication.

[0059] Effects of the Invention

[0060] According to one mode of the base station device, the terminal station device, the wireless communication system, and the wireless communication method disclosed in the present application, the effect of being capable of improving the efficiency of data communication in an RRC inactive mode is exerted. BRIEF DESCRIPTION OF DRAWINGS

[0061] Figure 1 is a block diagram showing the structure of a base station device of Embodiment 1.

[0062] Figure 2 is a block diagram showing the structure of a terminal station device of Embodiment 1.

[0063] Figure 3 is a timing chart showing an example of a wireless communication method.

[0064] Figure 4 is a timing chart showing another example of a wireless communication method.

[0065] Figure 5 is a timing chart showing an example of a small data transmission method.

[0066] Figure 6 is a timing chart showing a specific example of a wireless communication method of Embodiment 2.

[0067] Figure 7 is a timing chart showing another specific example of a wireless communication method of Embodiment 2.

[0068] Figure 8is a timing chart showing another example of the wireless communication method of Embodiment 2.

[0069] Figure 9 is a timing chart showing an example of the wireless communication method of Embodiment 3.

[0070] Figure 10 is a timing chart showing another example of the wireless communication method of Embodiment 3.

[0071] Figure 11 is a timing chart showing another example of the wireless communication method of Embodiment 3.

[0072] Figure 12 is a timing chart showing an example of the wireless communication method of Embodiment 4.

[0073] Figure 13 is a timing chart showing another example of the wireless communication method of Embodiment 4. DETAILED DESCRIPTION

[0074] Embodiments of a base station device, a terminal station device, a wireless communication system, and a wireless communication method disclosed in the present application will be explained in detail below with reference to the accompanying drawings. Note that the present application is not limited to the embodiments.

[0075] (Embodiment 1)

[0076] Figure 1 is a block diagram showing the structure of the base station device 100 of Embodiment 1. Figure 1 The base station device 100 shown in FIG. 1 has a network interface (hereinafter referred to as a "network IF") 110, a processor 120, a memory 130, and a wireless communication section 140.

[0077] The network IF 110 is wiredly connected to a core network not shown, and transmits and receives signals between devices constituting the core network.

[0078] The processor 120, for example, has a CPU (Central Processing Unit), an FPGA (Field Programmable Gate Array), or a DSP (Digital Signal Processor), and the like, and is a control unit that controls the entire base station device 100. Further, the processor 120 performs setting related to a region of a radio resource in which a control signal for performing communication with a terminal station device that is a communication counterpart of the base station device 100 is decoded, and a time interval in which the region becomes valid in the terminal station device. That is, the processor 120, for example, sets an interval corresponding to a first communication with the terminal station device and an interval corresponding to a second communication with the terminal station device, and controls so that the terminal station device intermittently uses each interval to perform communication. In addition, the processor 120 controls communication of the terminal station device by notifying the terminal station device of information related to setting of the above intervals by transmitting control information via the radio communication unit 140.

[0079] The memory 130, for example, has a RAM (Random Access Memory) or a ROM (Read Only Memory), and the like, and stores information used for processing of the processor 120.

[0080] The radio communication unit 140 performs radio communication with a terminal station device that is a communication counterpart. The radio communication unit 140, for example, transmits control information including information related to setting of an interval to the terminal station device. Further, the radio communication unit 140 receives data transmitted from the terminal station device. In addition, the radio communication unit 140 can also perform communication with the terminal station device when the terminal station device shifts to a prescribed state.

[0081] Figure 2 is a block diagram that shows a structure of the terminal station device 200 of Embodiment 1. Figure 2 The terminal station device 200 shown in the drawing has a radio communication unit 210, a processor 220, and a memory 230.

[0082] The radio communication unit 210 performs radio communication with a base station device 100 that is a communication counterpart. The radio communication unit 210, for example, receives control information from the base station device 100, the control information including information related to setting of a time interval in which a region of a radio resource in which a control signal is decoded becomes valid. Further, the radio communication unit 210, for example, transmits small data to the base station device 100. In addition, the radio communication unit 210 can also perform communication with the base station device 100 when the terminal station device 200 shifts to a prescribed state.

[0083] The processor 220, for example, has a CPU, an FPGA, or a DSP, and the like, and is a control unit that controls the entire terminal station device 200. Further, the processor 220 receives a setting from the base station device 100 regarding a region of a radio resource for decoding a control signal used for the terminal station device 200 to perform communication and a time interval in which the region becomes valid. That is, the processor 220, for example, sets an interval corresponding to the first communication of the terminal station device 200 and an interval corresponding to the second communication of the terminal station device 200, and performs control to intermittently use each interval to perform communication. At this time, the processor 220 performs control to perform communication according to an implementation state of data communication.

[0084] The memory 230, for example, has a RAM or a ROM, and the like, and stores information used for processing of the processor 220.

[0085] Next, a wireless communication method of the base station device 100 and the terminal station device 200 configured as described above will be described with reference to Figure 3 , 4

[0086] Figure 3 is a timing chart indicating an example of a wireless communication method. Here, the terminal station device 200 shifts to a prescribed state in which power supply to the wireless communication unit 210 is reduced to be low power consumption. In Figure 3 , a time interval in which a wireless reception circuit of the wireless communication unit 210 is turned on or off is shown. As Figure 3 indicated, the base station device 100 transmits control information including information (hereinafter referred to as "interval setting information") regarding a setting of an interval corresponding to the first communication of the terminal station device 200 and an interval corresponding to the second communication of the terminal station device 200 (step S101).

[0087] When the terminal station device 200 receives the interval setting information, the terminal station device 200 turns on the wireless reception circuit in the interval corresponding to the first communication, and receives a control signal related to the first communication from the base station device 100 (step S102). Then, the terminal station device 200 turns off the wireless reception circuit when the interval corresponding to the first communication elapses.

[0088] After that, when small data SD that should be transmitted from the terminal station device 200 is generated, the terminal station device 200 performs the second communication to transmit the small data SD to the base station device 100 using the radio resource CG set in advance by the base station device 100 (step S103). Further, the terminal station device 200 starts a timer 301 corresponding to the second communication according to the interval setting information, and turns on the wireless reception circuit in an interval before the timer 301 expires.

[0089] ​The base station device 100 that receives the small data SD from the terminal station device 200 transmits a control signal to the terminal station device 200 in accordance with the small data SD (step S104). Since the terminal station device 200 sets the wireless reception circuit to be on in the period until the expiration of the timer 301, it is able to receive the control signal in step S104. Then, the terminal station device 200 turns off the wireless reception circuit at the expiration of the timer 301.

[0090] In addition, the first communication can also be periodic. Thereafter, the terminal station device 200 turns on the wireless reception circuit in the period corresponding to the first communication that is implemented periodically, and receives the control signal involved in the first communication from the base station device 100 (step S105). Then, the terminal station device 200 turns off the wireless reception circuit when the period corresponding to the first communication has elapsed.

[0091] In this way, the terminal station device 200 controls the period in which the wireless reception circuit is turned on in accordance with the setting of the base station device 100, so the terminal station device 200 is able to receive the control signal corresponding to the transmission of the small data SD, and is able to minimize the frequency of switching the on and off of the wireless reception circuit, improving the efficiency of data communication.

[0092] Figure 4 is a timing chart showing another example of a wireless communication method. In Figure 4 , the same parts as in Figure 3 are labeled with the same reference numerals. In Figure 4 , it is also assumed that the terminal station device 200 shifts to the prescribed state in which the power supply to the wireless communication section 210 is reduced to low power consumption. As Figure 4 indicated, the base station device 100 transmits control information including period setting information (step S101).

[0093] The terminal station device 200, when receiving the period setting information, turns on the wireless reception circuit in the period corresponding to the first communication, and receives the control signal involved in the first communication from the base station device 100 (step S102). In addition, the terminal station device 200 starts the timer 302 in accordance with the period setting information, and turns on the wireless reception circuit in the period until the expiration of the timer 302.

[0094] Thereafter, when the small data SD that should be transmitted from the terminal station device 200 is generated, the terminal station device 200 implements the second communication that transmits the small data SD to the base station device 100 using the wireless resource CG that was set in advance by the base station device 100 (step S103).

[0095] The base station device 100, which receives small data SD from the terminal station device 200, sends a control signal to the terminal station device 200 based on the small data SD (step S104). Since the terminal station device 200 turns on the wireless receiving circuit during the interval before the timer 302 expires, it can receive the control signal in step S104. Then, the terminal station device 200 turns off the wireless receiving circuit when the timer 302 expires.

[0096] Then, the terminal station device 200 activates the wireless receiving circuit within the interval corresponding to the first communication and receives the control signals involved in the first communication from the base station device 100 (step S105). Then, the terminal station device 200 deactivates the wireless receiving circuit when it passes through the interval corresponding to the first communication.

[0097] exist Figure 4 In the example shown, the first communication could also be a periodic communication, and the radio resource CG could be a periodic resource. That is, the period of the periodically implemented first communication and the period of the periodic radio resource CG correspond to each other in terms of time length. Then, timer 302 is set to expire at a predetermined time corresponding to these periods.

[0098] Thus, according to the settings of the base station device 100, the wireless receiving circuit is continuously connected in the interval corresponding to the first communication and the interval corresponding to the second communication about the small data SD. Therefore, the terminal station device 200 can receive the control signal corresponding to the transmission of the small data SD, and can set the frequency of switching the wireless receiving circuit on and off to a minimum, thereby improving the efficiency of data communication.

[0099] As described above, according to this embodiment, based on the settings of the base station device, the terminal station device controls the interval during which the wireless receiving circuit is turned on to intermittently perform communication. Therefore, the terminal station device can receive control signals corresponding to the transmission of small data and can minimize the frequency of switching the wireless receiving circuit on and off, thereby improving the efficiency of data communication.

[0100] Furthermore, in the above-described embodiment 1, as an example, the periodically implemented first communication may be, for example, the transmission and reception of paging signals, and the second communication may be the transmission and reception of small data. Moreover, regarding the second communication, the control signals received by the terminal station device 200 may also be transmitted using a control channel such as a PDCCH. In this case, a region of inherent radio resources (i.e., a UE-specific search space (USS)) may be set for each terminal station device 200 within the control channel. Furthermore, in Figure 4In the example shown, the period of the first communication and the period of the periodic wireless resources CG become the corresponding time lengths. Specifically, for example, in a case where the subcarrier spacing is 15 KHz, the period of the periodic wireless resources CG can also be set to 320 ms * 14 symbols * N (N = 1, 2, 3, 4).

[0101] (Embodiment 2)

[0102] However, it is being studied that in a wireless communication system using, for example, FR2 (Frequency Range 2) including a frequency band of a millimeter wave band and the like, a base station device expands a cell by forming beams in multiple directions, and a terminal station device selects a beam with high reception power to communicate with the base station device. In this case, for example, when the terminal station device transmits small data in a CG manner using a wireless resource set in advance, the terminal station device transmits the small data using the wireless resource set before the best beam is selected.

[0103] Specifically, for example, as shown in Figure 5 The base station device 100 sets a wireless resource CG that the terminal station device 200 can use in transmission of small data SD by broadcast information such as an MIB (Master Information Block) or an SIB (System Information Block), or dedicated control information of an RRC layer (step S10). The terminal station device 200 sets the wireless resource CG in accordance with the broadcast information or the dedicated control information received from the base station device 100, and when small data SD is generated, transmits the small data SD using the wireless resource CG that comes next in timing (step S20). At this time, the terminal station device 200 selects a beam to use in transmission of the small data SD from among multiple beams formed by the base station device 100, but since the wireless resource CG is set in advance, a certain restriction is generated in selection of the beam. Further, from the time when the wireless resource CG is set to the time when the terminal station device 200 transmits the small data SD, a relatively long time can have passed, and during this period, the terminal station device 200 sometimes moves. Therefore, the wireless resource CG used in transmission of the small data SD is not necessarily the best wireless resource.

[0104] Therefore, in Embodiment 2, a case where the efficiency of data communication is improved using the best beam and the wireless resource is described. In particular, in Embodiment 2, a case where the wireless resource CG used in transmission of small data SD is set using a 4-step random access procedure is described.

[0105] The structure of the base station device 100 and the terminal station device 200 of Embodiment 2 is the same as that of the base station device 100 and the terminal station device 200 of Embodiment 1 Figure 1) and the terminal station device 200 Figure 2 ) are the same. Figure 6 is a timing chart showing a specific example of the wireless communication method of Embodiment 2. Here, it is assumed that the terminal station device 200 shifts to the RRC inactive mode in which the power supply to the wireless communication section 210 is reduced to be low power consumption. In Figure 6 , the time interval in which the wireless reception circuit of the wireless communication section 210 is turned on or off is shown.

[0106] The base station device 100 transmits control information including interval setting information that is information about the setting of the interval corresponding to the paging frame and the interval corresponding to the small data communication (step S201). In the interval setting information, for example, information that sets the time of the paging frame, information that sets the time of the timer that is started when the small data is transmitted, and the like can be included. Also, as the control information including the interval setting information, for example, broadcast information such as MIB or SIB, or dedicated control information of the RRC layer is used.

[0107] The terminal station device 200, when receiving the interval setting information, turns on the wireless reception circuit in the interval corresponding to the paging frame, for example, and receives the control signal such as the PDCCH relating to the paging from the base station device 100. Then, the terminal station device 200 turns off the wireless reception circuit when the interval corresponding to the paging frame elapses.

[0108] After that, when the small data SD that should be transmitted from the terminal station device 200 is generated, the terminal station device 200 selects the best beam from the plurality of beams formed by the base station device 100, and transmits a message (MSG1) including the preamble corresponding to the selected beam to the base station device 100 (step S202). The terminal station device 200 turns on the wireless reception circuit after transmitting the MSG1 in order to receive the message corresponding to the MSG1.

[0109] The base station device 100 that receives the MSG1 decides the timing advance value (hereinafter referred to as "TA value") that adjusts the transmission timing of the terminal station device 200, and allocates Temporary C-RNTI (Cell-Radio Network Temporary Identifier) that is a temporary identifier to the terminal station device 200. Then, the base station device 100 transmits a message (MSG2) including the TA value and the Temporary C-RNTI to the terminal station device 200 (step S203).

[0110] The terminal station apparatus 200 that received the MSG2 including the TA value judges that synchronization of the uplink is established, and starts a time alignment timer 311 that specifies a duration of synchronization of the uplink. After this, until the time alignment timer 311 expires, the processor 220 of the terminal station apparatus 200 can arbitrarily set the on and off of the wireless reception circuit. Further, the terminal station apparatus 200 holds the Temporary C-RNTI included in the MSG2 until the time alignment timer 311 expires.

[0111] Then, the terminal station apparatus 200 transmits a message (MSG3) equivalent to an RRC resume request (RRC ResumeRequest) to the base station apparatus 100 (step S204). At this time, the terminal station apparatus 200 can also transmit a part of the small data SD included in the MSG3. The base station apparatus 100 that received the MSG3 decides the wireless resource CG to be used by the terminal station apparatus 200 in the transmission of the small data SD, and transmits a message (MSG4) including the setting information of the wireless resource CG to the terminal station apparatus 200 (step S205). In addition, the MSG4 is equivalent to an RRC Release w / suspendConfig. Here, since the wireless resource CG is decided in a state where the best beam is selected by the terminal station apparatus 200, the best wireless resource CG is set. It is also possible to set the wireless resource CG in multiple time domains.

[0112] The terminal station apparatus 200 transmits a part of the small data SD to the base station apparatus 100 using the wireless resource CG after receiving the MSG4 (step S206). Further, the terminal station apparatus 200 starts a timer 312 related to the communication of the small data SD according to the interval setting information received in step S201, and turns on the wireless reception circuit in the interval until the timer 312 expires. In addition, the interval setting information of the timer and the like is received in step S201 here, but it is also possible to receive the interval setting information of the timer and the like related to the wireless resource CG in step S205.

[0113] The base station device 100, having received small data SD from the terminal station device 200, transmits a control signal for the PDCCH based on the small data SD (step S207). At this time, the base station device 100 masks the PDCCH according to the value of the Temporary C-RNTI contained in the MSG2 and transmits it. Since the terminal station device 200 keeps the radio receiving circuit on during the interval before the timer 312 expires, it can receive the control signal for the PDCCH in step S207. Furthermore, since the terminal station device 200 retains the Temporary C-RNTI notified by the MSG2, it can decode the control signal masked according to the value of the Temporary C-RNTI. Then, the terminal station device 200 disconnects the radio receiving circuit when the timer 312 expires.

[0114] Subsequently, the terminal station device 200 uses the next radio resource CG to send the remaining portion of the small data SD to the base station device 100 (step S208). In addition, the terminal station device 200 starts a timer 313 related to the communication of the small data SD according to the interval setting information received in step S201, and connects the radio receiving circuit in the interval before the timer 313 expires.

[0115] The base station device 100, having received small data SD from the terminal station device 200, transmits a control signal for the PDCCH based on the small data SD (step S209). At this time, the base station device 100 masks the PDCCH according to the value of the Temporary C-RNTI contained in the MSG2 and transmits it. Since the terminal station device 200 keeps the radio receiving circuit on during the interval before the timer 313 expires, it can receive the control signal for the PDCCH in step S209. Furthermore, since the terminal station device 200 retains the Temporary C-RNTI notified by the MSG2, it can decode the control signal masked according to the value of the Temporary C-RNTI. Then, the terminal station device 200 disconnects the radio receiving circuit when the timer 313 expires.

[0116] Thus, in Figure 6 In the example shown, timers 312 and 313 are started whenever small data SD is transmitted using wireless resource CG, and the wireless receiving circuit remains active until timers 312 and 313 expire. As a result, even when the terminal station device 200 is in RRC inactive mode, it can reliably receive the control signal of PDCCH for small data SD.

[0117] In addition, the wireless resource CG is set to be used twice to transmit the small data SD, but the wireless resource CG can be set to be used three or more times, and the small data SD can be transmitted using each wireless resource CG. Further, if the small data SD can be transmitted by one wireless resource CG, the small data SD can not be transmitted in step S208. In this case, instead of the small data SD, for example, buffer status information (BSR: Buffer Status Report) indicating the state of the buffer of the terminal station device 200 can be transmitted using the wireless resource CG.

[0118] Figure 7 is a timing chart showing another specific example of the wireless communication method according to Embodiment 2. In Figure 7 , the same parts as Figure 6 are denoted by the same reference numerals, and detailed description thereof will be omitted. Here, it is assumed that the terminal station device 200 shifts to the RRC inactive mode in which the power supply to the wireless communication unit 210 is reduced to be low power consumption. In Figure 7 , a time interval in which the wireless reception circuit of the wireless communication unit 210 is turned on or off is shown.

[0119] When the base station device 100 transmits the control information including the interval setting information (step S201), the terminal station device 200 turns on the wireless reception circuit in an interval corresponding to a paging frame, for example, and turns off the wireless reception circuit when the interval corresponding to the paging frame elapses. After that, when the small data SD that should be transmitted from the terminal station device 200 is generated, the terminal station device 200 selects the best beam from among the plurality of beams formed by the base station device 100, and transmits MSG1 to the base station device 100 (step S202). The terminal station device 200 turns on the wireless reception circuit after the transmission of the MSG1 in order to receive a message corresponding to the MSG1.

[0120] The base station device 100 that received the MSG1 transmits MSG2 including a TA value and a Temporary C-RNTI to the terminal station device 200 (step S203). The terminal station device 200 that received the MSG2 including the TA value starts the time adjustment timer 311. Further, the terminal station device 200 holds the Temporary C-RNTI included in the MSG2 until the time adjustment timer 311 expires.

[0121] Then, the terminal station device 200 transmits MSG3 to the base station device 100 (step S204). At this time, the terminal station device 200 can also include a part of the small data SD in MSG3 and transmit it. When MSG3 is transmitted, the terminal station device 200 starts a contention resolution timer 314, and attempts the reception detection of MSG4 until the contention resolution timer 314 expires. At this time, the terminal station device 200 handles the contention resolution timer 314 as a timer corresponding to the above-described timer 312 and the timer 313, and turns on the wireless reception circuit in the period until the contention resolution timer 314 expires (case 1). Alternatively, in order to separate the functions of the timers, the terminal station device 200 can define a timer different from the contention resolution timer 314, and handle the timer as a timer corresponding to the above-described timer 312 and the timer 313. In this case, the terminal station device 200 turns on the wireless reception circuit in the period until the defined other timer expires (case 2).

[0122] In case 1, the terminal station device 200 can also extend the setting time of the contention resolution timer 314 started when MSG3 is transmitted, according to the period setting information received in step S201. Specifically, the setting time of the contention resolution timer 314 is extended by the time specified by the period setting information, so that the contention resolution timer 314 expires after the time in which the wireless resource CG is followed by the time in which the reception of the control signal of the PDCCH is waited for. Further, the maximum setting time of the contention resolution timer 314 is specified as 64 subframes (corresponding to 64 ms), but a longer setting time can also be set in the contention resolution timer 314 as needed. When the contention resolution timer 314 is started, the terminal station device 200 turns on the wireless reception circuit in the period until the contention resolution timer 314 expires. Hereinafter, the description of the present embodiment will be continued assuming that the setting time of the contention resolution timer 314 is extended.

[0123] The base station device 100 that has received MSG3 decides the wireless resource CG used by the terminal station device 200 in the transmission of the small data SD, and transmits MSG4 including the setting information of the wireless resource CG to the terminal station device 200 (step S205). The terminal station device 200, after receiving MSG4, transmits a part of the small data SD to the base station device 100 using the wireless resource CG (step S206).

[0124] The base station device 100, having received small data SD from the terminal station device 200, sends a control signal for the PDCCH based on the small data SD (step S207). The terminal station device 200 sets the wireless receiving circuit to on during the extended contention resolution timer 314 period before it expires, thus enabling it to receive the control signal for the PDCCH in step S207.

[0125] Subsequently, the terminal station device 200 uses the next radio resource CG to send the remaining portion of the small data SD to the base station device 100 (step S208). The base station device 100, having received the small data SD from the terminal station device 200, sends a PDCCH control signal based on the small data SD (step S209). The terminal station device 200 keeps the radio receiving circuit on during the extended contention resolution timer 314 until it expires, thus enabling it to receive the PDCCH control signal in step S209. Then, when the contention resolution timer 314 expires, the terminal station device 200 disconnects the radio receiving circuit.

[0126] Thus, in Figure 7 In the example shown, by extending the set time of the contention resolution timer 314, the wireless receiving circuit remains on for an extended period until all PDCCH control signals for the multiple radio resource CGs are received. As a result, the wireless receiving circuit does not temporarily disconnect after each radio resource CG, thus suppressing on / off switching and further improving control efficiency.

[0127] Figure 8 This is a timing diagram illustrating yet another specific example of the wireless communication method of Implementation Method 2. Figure 8 In the middle, to and Figure 6 Identical parts are labeled with the same reference numerals, and their detailed descriptions will be omitted. Here, it is assumed that the terminal station device 200 switches to a low-power RRC inactive mode due to reduced power supply to the wireless communication unit 210. Figure 8 The diagram shows the time interval during which the wireless receiving circuit of the wireless communication unit 210 is turned on or off.

[0128] When the base station device 100 sends control information containing interval setting information (step S201), the terminal station device 200, for example, turns on the wireless receiving circuit within the interval corresponding to the paging frame, and turns off the wireless receiving circuit after passing through the interval corresponding to the paging frame. Then, when a small data SD to be transmitted from the terminal station device 200 is generated, the terminal station device 200 selects the optimal beam from the multiple beams formed by the base station device 100 and transmits MSG1 to the base station device 100 (step S202). After transmitting MSG1, the terminal station device 200 turns on the wireless receiving circuit to receive the message corresponding to MSG1.

[0129] The base station device 100 that has received the MSG 1 transmits the MSG 2 including the TA value and the Temporary C-RNTI to the terminal station device 200 (step S203). The terminal station device 200 that has received the MSG 2 including the TA value starts the time adjustment timer 311. Further, the terminal station device 200 holds the Temporary C-RNTI included in the MSG 2 until the time adjustment timer 311 expires.

[0130] Then, the terminal station device 200 transmits the MSG 3 to the base station device 100 (step S204). At this time, the terminal station device 200 can also transmit a part of the small data SD in the MSG 3. Further, the terminal station device 200 starts the contention resolution timer for waiting for the reception of the MSG 4 at the time of the transmission of the MSG 3, and turns on the wireless reception circuit during the period until the contention resolution timer expires. Further, the maximum set time of the contention resolution timer is set to 64 subframes (corresponding to 64 ms), but a longer set time can also be set in the contention resolution timer as needed.

[0131] The base station device 100 that has received the MSG 3 decides the wireless resource CG used by the terminal station device 200 in the transmission of the small data SD, and transmits the reconfiguration information of the RRC layer including the set information of the wireless resource CG to the terminal station device 200 (step S211). At this time, the base station device 100 sets the wireless resource CG at the timing before the MSG 4 is transmitted. Here, since the wireless resource CG is decided in the state where the best beam is selected by the terminal station device 200, the best wireless resource CG is set. The wireless resource CG can also be set in a plurality of time domains.

[0132] The terminal station device 200, after receiving the reconfiguration information, transmits the small data SD to the base station device 100 using the wireless resource CG set at the timing before the reception of the MSG 4 (step S212). The base station device 100 that has received the small data SD from the terminal station device 200 transmits the control signal of the PDCCH according to the small data SD (step S213). At this time, the base station device 100 masks the PDCCH according to the value of the Temporary C-RNTI included in the MSG 2 and transmits it. The terminal station device 200 turns on the wireless reception circuit during the period until the contention resolution timer for waiting for the reception of the MSG 4 expires, and thus can receive the control signal of the PDCCH in step S213. Further, since the terminal station device 200 holds the Temporary C-RNTI notified by the MSG 2, it can decode the control signal masked according to the value of the Temporary C-RNTI.

[0133] After that, the base station device 100 transmits the MSG4 corresponding to the MSG3 to the terminal station device 200 during a period until the expiration of the contention resolution timer of the terminal station device 200 (step S205). The terminal station device 200, upon receiving the MSG4, disconnects the wireless reception circuit if the contention resolution timer expires.

[0134] Thus, in the example shown in FIG. 8, the terminal station device 200 transmits the small data SD using the wireless resource CG during a period until the expiration of the contention resolution timer for waiting for the reception of the MSG4 after the transmission of the MSG3, and receives the control signal of the PDCCH. Therefore, the terminal station device 200 can monitor the PDCCH during a period from the transmission of the MSG3 to the reception of the MSG4, and does not need to set a new timer for waiting for the reception of the control signal of the PDCCH corresponding to the transmission of the small data SD. Figure 8

[0135] As described above, according to the present embodiment, after the generation of the small data, the wireless resource for transmitting the small data by the 4-step random access procedure is set, and the interval in which the wireless reception circuit of the terminal station device is kept on after the transmission of the small data is also set. Therefore, the terminal station device can receive the control signal corresponding to the transmission of the small data, and can minimize the frequency of switching the on and off of the wireless reception circuit, and improve the efficiency of data communication. Further, since the small data is transmitted using the optimal wireless resource set after the optimal beam is selected, the reception quality of the small data can be improved.

[0136] (Embodiment 3)

[0137] In Embodiment 3, a case where the wireless resource CG used in the transmission of the small data SD is set by the 2-step random access procedure is described.

[0138] The structure of the base station device 100 and the terminal station device 200 of Embodiment 3 is the same as that of the base station device 100 ( Figure 1 ) and the terminal station device 200 ( Figure 2 ) of Embodiment 1. Figure 9 is a timing chart showing a specific example of the wireless communication method of Embodiment 3. Here, it is assumed that the terminal station device 200 shifts to the RRC inactive mode in which the power supply to the wireless communication unit 210 is reduced to low power consumption. In Figure 9 , the time interval in which the wireless reception circuit of the wireless communication unit 210 is on or off is shown.

[0139] ​The base station device 100 transmits control information including interval setting information, which is information about setting of an interval corresponding to a paging frame and an interval corresponding to small data communication (step S301). In the interval setting information, for example, information of a time at which a paging frame is set, information of a set time of a timer that is started when small data is transmitted, and the like can be included. Also, as the control information including the interval setting information, for example, broadcast information such as an MIB or an SIB, or dedicated control information of an RRC layer is used.

[0140] When the interval setting information is received, the terminal station device 200 turns on a radio reception circuit in the interval corresponding to the paging frame, for example, and receives a control signal such as a PDCCH relating to paging from the base station device 100. Then, the terminal station device 200 turns off the radio reception circuit when the interval corresponding to the paging frame elapses.

[0141] After that, when small data SD that should be transmitted from the terminal station device 200 is generated, the terminal station device 200 selects an optimal beam from a plurality of beams formed by the base station device 100, and transmits a message (MSGA) including a preamble corresponding to the selected beam to the base station device 100 (step S302). At this time, the terminal station device 200 can also transmit a part of the small data SD in the MSGA. The MSGA is a message that combines MSG1 and MSG3 in the 4-step random access procedure explained in Embodiment 2. The terminal station device 200 turns on the radio reception circuit after transmitting the MSGA in order to receive a message corresponding to the MSGA.

[0142] The base station device 100 that has received the MSGA decides a TA value that adjusts a transmission timing of the terminal station device 200, and allocates a C-RNTI (Cell-Radio Network Temporary Identifier) that is an identifier to the terminal station device 200. Then, the base station device 100 transmits a message (MSGB) including the TA value and the C-RNTI to the terminal station device 200 (step S303). The MSGB is a message that combines MSG2 and MSG4 in the 4-step random access procedure explained in Embodiment 2, but RRC Release w / suspendConfig is not transmitted in the MSG4.

[0143] The terminal station apparatus 200 that has received the MSGB including the TA value judges that synchronization of the uplink is established, and starts a time adjustment timer 321 that specifies a duration of synchronization of the uplink. Thereafter, until the time adjustment timer 321 expires, the processor 220 of the terminal station apparatus 200 can arbitrarily set on and off of the wireless reception circuit. Further, the terminal station apparatus 200 holds the C-RNTI included in the MSGB until the time adjustment timer 321 expires.

[0144] The base station apparatus 100, after transmitting the MSGB, decides a wireless resource CG used by the terminal station apparatus 200 in transmission of the small data SD, and transmits dedicated control information including setting information of the wireless resource CG to the terminal station apparatus 200 (step S304). The dedicated control information corresponds to RRC Release w / suspendConfig. Here, since the wireless resource CG is decided in a state where the best beam is selected by the terminal station apparatus 200, the best wireless resource CG is set. The wireless resource CG can also be set in a plurality of time domains.

[0145] The terminal station apparatus 200, after receiving the dedicated control information, transmits a part of the small data SD to the base station apparatus 100 using the wireless resource CG (step S305). Further, the terminal station apparatus 200 starts a timer 322 related to communication of the small data SD according to the interval setting information received in step S301, and turns on the wireless reception circuit in an interval until the timer 322 expires.

[0146] The base station apparatus 100 that has received the small data SD from the terminal station apparatus 200 transmits a control signal of the PDCCH according to the small data SD (step S306). At this time, the base station apparatus 100 masks and transmits the PDCCH according to the value of the C-RNTI included in the MSGB. The terminal station apparatus 200 turns on the wireless reception circuit in an interval until the timer 322 expires, and thus can receive the control signal of the PDCCH in step S306. Further, since the terminal station apparatus 200 holds the C-RNTI notified by the MSGB, it can decode the control signal masked according to the value of the C-RNTI. Then, the terminal station apparatus 200 turns off the wireless reception circuit when the timer 322 expires.

[0147] Thereafter, the terminal station apparatus 200 transmits the remaining part of the small data SD to the base station apparatus 100 using the next wireless resource CG (step S307). Further, the terminal station apparatus 200 starts a timer 323 related to communication of the small data SD according to the interval setting information received in step S301, and turns on the wireless reception circuit in an interval until the timer 323 expires.

[0148] The base station device 100 that has received the small data SD from the terminal station device 200 transmits the control signal of the PDCCH in accordance with the small data SD (step S308). At this time, the base station device 100 masks and transmits the PDCCH in accordance with the value of the C-RNTI included in the MSGB. Since the terminal station device 200 has the wireless reception circuit turned on in the interval until the expiration of the timer 323, it is possible to receive the control signal of the PDCCH in step S308. Further, since the terminal station device 200 retains the C-RNTI notified by the MSGB, it is possible to decode the control signal masked in accordance with the value of the C-RNTI. Then, the terminal station device 200 turns off the wireless reception circuit at the expiration of the timer 323.

[0149] Thus, in the example shown in FIG. 12, the timer 322, 323 is started each time the small data SD is transmitted using the wireless resource CG, and the interval in which the wireless reception circuit is turned on continues until the expiration of the timer 322, 323. As a result, the terminal station device 200 is able to reliably receive the control signal of the PDCCH for the small data SD even in the RRC inactive mode. Figure 9

[0150] In addition, although it is assumed here that the small data SD is transmitted by 2 times of the wireless resource CG, the wireless resource CG can be set to 3 times or more, and the small data SD can be transmitted using each of the wireless resource CG. Further, if the small data SD can be transmitted by 1 time of the wireless resource CG, the small data SD can not be transmitted in step S307. In this case, instead of the small data SD, for example, buffer status information (BSR) indicating the state of the buffer of the terminal station device 200 can be transmitted using the wireless resource CG.

[0151] Figure 10 is a timing chart showing another specific example of the wireless communication method according to Embodiment 3. In Figure 10 the same parts as Figure 9 are denoted by the same reference numerals, and detailed description thereof will be omitted. Here, it is assumed that the terminal station device 200 shifts to the RRC inactive mode in which the power supply to the wireless communication unit 210 is reduced to be low power consumption. In Figure 10 , the time interval in which the wireless reception circuit of the wireless communication unit 210 is turned on or off is shown.

[0152] ​When the base station device 100 transmits the control information including the interval setting information (step S301), the terminal station device 200 turns on the wireless receiving circuit, for example, in the interval corresponding to the paging frame, and turns off the wireless receiving circuit when the interval corresponding to the paging frame elapses. After that, if small data SD that should be transmitted from the terminal station device 200 is generated, the terminal station device 200 selects the best beam from among the plurality of beams formed by the base station device 100, and transmits the MSGA to the base station device 100 (step S302). At this time, the terminal station device 200 can also transmit a part of the small data SD included in the MSGA.

[0153] After the transmission of the MSGA, the terminal station device 200 starts a response window (msg B-ResponseWindow) 324, and attempts the reception detection of the MSGB until the end of the response window 324. At this time, the terminal station device 200 handles the response window 324 as a timer corresponding to the above-described timer 322 and the timer 323, and turns on the wireless receiving circuit in the interval until the end of the response window 324 (case 1). Alternatively, in order to separate the functions of the timers, the terminal station device 200 can also define a timer different from the response window 324, and handle the timer as a timer corresponding to the above-described timer 322 and the timer 323. In this case, the terminal station device 200 turns on the wireless receiving circuit in the interval until the expiration of the other defined timer (case 2).

[0154] In the case 1, the terminal station device 200 can also extend the set time of the response window 324 for waiting for the reception of the MSGB, in accordance with the interval setting information received in step S301. Specifically, the set time of the response window 324 is extended by the time designated by the interval setting information, so that the response window 324 expires after the time elapses after the wireless resource CG in which the control signal of the PDCCH is waited for. In addition, the maximum set time of the response window 324 for the MSGB is currently set to 1320 slots, but a response window 324 with a longer set time can also be set as needed. When the response window 324 starts, the terminal station device 200 turns on the wireless receiving circuit in the interval until the end of the response window 324. Hereinafter, the set time of the response window 324 is extended, and the description of the present embodiment is continued.

[0155] The base station device 100 that has received the MSGA transmits the MSGB including the TA value and the C-RNTI to the terminal station device 200 (step S303). The terminal station device 200 that has received the MSGB including the TA value starts the time adjustment timer 321. In addition, the terminal station device 200 holds the C-RNTI included in the MSGB until the expiration of the time adjustment timer 321.

[0156] After transmitting the MSGB, the base station device 100 determines the radio resource CG to be used by the terminal station device 200 in transmitting the small data SD, and sends dedicated control information containing the setting information of the radio resource CG to the terminal station device 200 (step S304). After receiving the dedicated control information, the terminal station device 200 uses the radio resource CG to transmit a portion of the small data SD to the base station device 100 (step S305).

[0157] The base station device 100, having received small data SD from the terminal station device 200, sends a control signal for the PDCCH based on the small data SD (step S306). Since the terminal station device 200 has its radio receiving circuit enabled during the interval before the end of the extended response window 324, it is able to receive the control signal for the PDCCH in step S306.

[0158] Subsequently, the terminal station device 200 uses the next radio resource CG to send the remaining portion of the small data SD to the base station device 100 (step S307). The base station device 100, having received the small data SD from the terminal station device 200, sends a PDCCH control signal based on the small data SD (step S308). The terminal station device 200 keeps the radio receiving circuit on during the interval before the extended response window 324 expires, thus enabling it to receive the PDCCH control signal in step S308. Then, the terminal station device 200 disconnects the radio receiving circuit when the response window 324 ends.

[0159] Thus, in Figure 10 In the example shown, the set time for the response window 324 used for MSGB is extended, and the wireless receiving circuit remains on until a control signal for the PDCCH for all multiple radio resource CGs is received. As a result, the wireless receiving circuit does not temporarily disconnect after each radio resource CG, thus suppressing on / off switching and further improving control efficiency.

[0160] Figure 11 This is a timing diagram illustrating yet another specific example of the wireless communication method of Implementation Method 3. Figure 11 In the middle, to and Figure 9 The same reference numerals are used for the same parts, and their detailed descriptions will be omitted. Here, it is assumed that the terminal station device 200 switches to a low-power RRC inactive mode due to reduced power supply to the wireless communication unit 210. Figure 11 The diagram shows the time interval during which the wireless receiving circuit of the wireless communication unit 210 is turned on or off.

[0161] When the base station device 100 transmits the control information including the interval setting information (step S301), the terminal station device 200 turns on the wireless receiving circuit, for example, in the interval corresponding to the paging frame, and turns off the wireless receiving circuit when the interval corresponding to the paging frame elapses. After that, if small data SD that should be transmitted from the terminal station device 200 is generated, the terminal station device 200 selects the best beam from the plurality of beams formed by the base station device 100, and transmits the MSGA to the base station device 100 (step S302). At this time, the terminal station device 200 can also transmit a part of the small data SD in the MSGA. Further, the terminal station device 200 starts a response window for waiting for reception of the MSGB at the time of transmission of the MSGA, and turns on the wireless receiving circuit in the interval until the end of the response window. In addition, the maximum setting time of the current response window is set to 1320 slots, but a response window with a longer setting time can also be set as needed.

[0162] The base station device 100 that has received the MSGA transmits the MSGB including the TA value and the C-RNTI to the terminal station device 200 (step S303). However, the RRC Release w / suspendConfig is not transmitted in this MSGB. The terminal station device 200 that has received the MSGB including the TA value starts the time adjustment timer 321. Further, the terminal station device 200 holds the C-RNTI included in the MSGB until the time adjustment timer 321 expires.

[0163] The base station device 100, after transmitting the MSGB, decides the radio resource CG used by the terminal station device 200 in the transmission of the small data SD, and transmits the reconfiguration information of the RRC layer including the setting information of the radio resource CG (for example, RRC reconfiguration) to the terminal station device 200 (step S311). At this time, the base station device 100 sets the radio resource CG at the timing before the transmission of the dedicated control information corresponding to the MSG4. Here, since the radio resource CG is decided in the state where the best beam is selected by the terminal station device 200, the best radio resource CG is set. The radio resource CG can also be set in a plurality of time domains.

[0164] After receiving the reset information, the terminal station device 200 uses the radio resource CG set before the reception of the dedicated control information to send the small data SD to the base station device 100 (step S312). The base station device 100, having received the small data SD from the terminal station device 200, sends a control signal for the PDCCH based on the small data SD (step S313). At this time, the base station device 100 masks the PDCCH according to the value of the C-RNTI contained in the MSGB and sends it. The terminal station device 200 keeps the radio receiving circuit on during the period before the response window for waiting for the MSGB reception ends, thus enabling it to receive the control signal for the PDCCH in step S313. Furthermore, since the terminal station device 200 retains the C-RNTI notified via the MSGB, it can decode the control signal masked according to the value of the C-RNTI.

[0165] Subsequently, during the period before the response window of the terminal station device 200 ends, the base station device 100 sends dedicated control information equivalent to MSG4 to the terminal station device 200 (step S304). After receiving the dedicated control information, the terminal station device 200 disconnects the wireless receiving circuit when the response window ends.

[0166] Thus, in Figure 11 In the example shown, after transmitting the MSGA, the terminal station device 200 transmits small data SD using radio resource CG and receives control signals for the PDCCH during the period before the response window for waiting for the reception of MSGB ends. Therefore, the terminal station device 200 only needs to monitor the PDCCH from the time the MSGA is transmitted until the dedicated control information equivalent to MSG4, i.e., RRCreasew / suspendConfig, is received; there is no need to set a new timer for waiting for the reception of control signals for the PDCCH for the transmission of small data SD.

[0167] As described above, according to this embodiment, after small data is generated, dedicated control information is used to set the wireless resources for transmitting the small data, and a range is set in which the wireless receiving circuit of the terminal station device remains on even after the small data is transmitted. Therefore, the terminal station device can receive control signals corresponding to the transmission of small data, and the frequency of switching the wireless receiving circuit on and off can be minimized, improving the efficiency of data communication. Furthermore, since the optimal wireless resources set after selecting the optimal beam are used to transmit the small data, the reception quality of the small data can be improved.

[0168] (Implementation Method 4)

[0169] In Implementation 4, other cases of setting the radio resource CG used in the transmission of small data SD using a two-step random access process will be described.

[0170] The structure of the base station device 100 and the terminal station device 200 in Embodiment 4 is the same as that of the base station device 100 in Embodiment 1. Figure 1 ) and terminal station device 200 ( Figure 2 The structures are the same. Figure 12 This is a timing diagram illustrating a specific example of the wireless communication method in Implementation Method 4. Figure 12 In the middle, to and Figure 9 Identical parts are labeled with the same reference numerals, and their detailed descriptions will be omitted. Here, it is assumed that the terminal station device 200 switches to a low-power RRC inactive mode due to reduced power supply to the wireless communication unit 210. Figure 12 The diagram shows the time interval during which the wireless receiving circuit of the wireless communication unit 210 is turned on or off.

[0171] When the base station device 100 sends control information containing interval setting information (step S301), the terminal station device 200, for example, turns on the wireless receiving circuit within the interval corresponding to the paging frame, and turns off the wireless receiving circuit after passing through the interval corresponding to the paging frame. Then, if a small data SD to be transmitted from the terminal station device 200 is generated, the terminal station device 200 selects the optimal beam from the multiple beams formed by the base station device 100 and transmits the MSGA to the base station device 100 (step S302). At this time, the terminal station device 200 may also include a portion of the small data SD in the MSGA for transmission. After transmitting the MSGA, the terminal station device 200 turns on the wireless receiving circuit to receive the message corresponding to the MSGA.

[0172] Upon receiving the MSGA, the base station device 100 determines to adjust the TA value of the transmission timing of the terminal station device 200 and assigns a C-RNTI as an identifier to the terminal station device 200. Furthermore, the base station device 100 determines the radio resource CG used by the terminal station device 200 in the transmission of small data SD, and sends a message (MSGB) containing the setting information of the radio resource CG, the TA value, and the C-RNTI to the terminal station device 200 (step S401). The MSGB is a message that combines the MSG2 and MSG4 messages from the four steps of the random access process described in Embodiment 2.

[0173] Upon receiving an MSGB containing a TA value, the terminal station device 200 determines that uplink synchronization has been established and starts a time adjustment timer 331 for a specified uplink synchronization duration. Thereafter, until the time adjustment timer 331 expires, the processor 220 of the terminal station device 200 can arbitrarily set the wireless receiving circuit to be on or off. Furthermore, the terminal station device 200 retains the C-RNTI contained in the MSGB until the time adjustment timer 331 expires.

[0174] The terminal station device 200 transmits a part of the small data SD to the base station device 100 using the radio resource CG after receiving the MSGB (step S305). Further, the terminal station device 200 starts the timer 322 related to the communication of the small data SD according to the interval setting information received in step S301, and turns on the radio reception circuit in the interval until the timer 322 expires.

[0175] The base station device 100 that received the small data SD from the terminal station device 200 transmits the control signal of the PDCCH according to the small data SD (step S306). At this time, the base station device 100 masks and transmits the PDCCH according to the value of the C-RNTI included in the MSGB. The terminal station device 200 turns on the radio reception circuit in the interval until the timer 322 expires, and thus can receive the control signal of the PDCCH in step S306. Further, since the terminal station device 200 retains the C-RNTI notified by the MSGB, it can decode the control signal masked according to the value of the C-RNTI. Then, the terminal station device 200 turns off the radio reception circuit when the timer 322 expires.

[0176] After that, the terminal station device 200 transmits the remaining part of the small data SD to the base station device 100 using the next radio resource CG (step S307). Further, the terminal station device 200 starts the timer 323 related to the communication of the small data SD according to the interval setting information received in step S301, and turns on the radio reception circuit in the interval until the timer 323 expires.

[0177] The base station device 100 that received the small data SD from the terminal station device 200 transmits the control signal of the PDCCH according to the small data SD (step S308). At this time, the base station device 100 masks and transmits the PDCCH according to the value of the C-RNTI included in the MSGB. Since the terminal station device 200 turns on the radio reception circuit in the interval until the timer 323 expires, it can receive the control signal of the PDCCH in step S308. Further, since the terminal station device 200 retains the C-RNTI notified by the MSGB, it can decode the control signal masked according to the value of the C-RNTI. Then, the terminal station device 200 turns off the radio reception circuit when the timer 323 expires.

[0178] Thus, in the present embodiment, the terminal station device 200 can receive the control signal of the PDCCH according to the small data SD in the interval until the timer expires, and decode the control signal masked according to the value of the C-RNTI notified by the MSGB. Figure 12In the example shown, when small data SD is transmitted using the wireless resources CG, the timers 322, 323 are started, and the wireless reception circuit is turned on for the period until the timers 322, 323 expire. As a result, the terminal station device 200 can reliably receive the control signal of the PDCCH for the small data SD even in the RRC inactive mode.

[0179] In addition, although the small data SD is transmitted by two wireless resources CGs in this example, the wireless resources CGs can be set to three or more, and the small data SD can be transmitted using each wireless resource CG. Furthermore, if the small data SD can be transmitted by one wireless resource CG, the small data SD can not be transmitted in step S307. In this case, instead of the small data SD, for example, buffer state information indicating the state of the buffer of the terminal station device 200 can be transmitted using the wireless resource CG.

[0180] Figure 13 is a timing chart showing another specific example of the wireless communication method of Embodiment 4. In Figure 13 the same parts as Figure 9 , 12 Embodiment 3 are denoted by the same reference numerals, and detailed descriptions thereof are omitted. In this example, it is assumed that the terminal station device 200 shifts to the RRC inactive mode in which the power supply to the wireless communication unit 210 is reduced to low power consumption. In Figure 13 , the time period in which the wireless reception circuit of the wireless communication unit 210 is turned on or off is shown.

[0181] When the base station device 100 transmits the control information including the period setting information (step S301), the terminal station device 200 turns on the wireless reception circuit in the period corresponding to the paging frame, for example, and turns off the wireless reception circuit when the period corresponding to the paging frame elapses. Thereafter, if the small data SD that should be transmitted from the terminal station device 200 is generated, the terminal station device 200 selects the best beam from among the plurality of beams formed by the base station device 100, and transmits the MSGA to the base station device 100 (step S302). At this time, the terminal station device 200 can transmit a part of the small data SD in the MSGA.

[0182] The terminal station apparatus 200 starts a response window 324 after the transmission of the MSGA, and attempts the reception detection of the MSGB until the end of the response window 324. At this time, the terminal station apparatus 200 treats the response window 324 as a timer corresponding to the timer 322 and the timer 323 described above, and turns on the wireless reception circuit in the period until the end of the response window 324 (Case 1). Alternatively, in order to separate the functions of the timers, the terminal station apparatus 200 can define a timer different from the response window 324, and treat the timer as a timer corresponding to the timer 322 and the timer 323 described above. In this case, the terminal station apparatus 200 turns on the wireless reception circuit in the period until the end of the other defined timer (Case 2).

[0183] In Case 1, the terminal station apparatus 200 can also extend the set time of the response window 324 for waiting for the reception of the MSGB, according to the interval set information received in step S301. When the response window 324 starts, the terminal station apparatus 200 turns on the wireless reception circuit in the period until the end of the response window 324. Hereinafter, the set time of the response window 324 is assumed to be extended, and the description of the present embodiment is continued.

[0184] The base station apparatus 100 that has received the MSGA transmits the MSGB including the set information of the wireless resource CG and including the TA value and the C-RNTI to the terminal station apparatus 200 (step S401). The terminal station apparatus 200 that has received the MSGB including the TA value starts the time adjustment timer 321. Further, the terminal station apparatus 200 holds the C-RNTI included in the MSGB until the time adjustment timer 321 expires.

[0185] The terminal station apparatus 200 transmits a part of the small data SD to the base station apparatus 100 using the wireless resource CG after receiving the MSGB (step S305). The base station apparatus 100 that has received the small data SD from the terminal station apparatus 200 transmits the control signal of the PDCCH according to the small data SD (step S306). The terminal station apparatus 200 can receive the control signal of the PDCCH in step S306 because the wireless reception circuit is turned on in the period until the end of the extended response window 324.

[0186] After that, the terminal station device 200 transmits the remaining part of the small data SD to the base station device 100 using the next radio resource CG (step S307). The base station device 100 that has received the small data SD from the terminal station device 200 transmits the control signal of the PDCCH in accordance with the small data SD (step S308). The terminal station device 200 turns on the radio reception circuit in the period until the expiration of the extended response window 324, and thus can receive the control signal of the PDCCH in step S308. Then, the terminal station device 200 turns off the radio reception circuit at the end of the response window 324.

[0187] Thus, in the example shown in FIG. 12, the setting time of the response window 324 for the MSGB is extended, and the period in which the radio reception circuit is turned on continues until the control signal of the PDCCH for the entire plurality of radio resources CG is received. As a result, the radio reception circuit is not temporarily turned off after each radio resource CG, and the efficiency of the control can be further improved by suppressing the switching of the on / off. Figure 13

[0188] As described above, according to the present embodiment, after the generation of the small data, the radio resource for transmitting the small data is set using the 2-step random access procedure, and the period in which the radio reception circuit of the terminal station device is kept turned on after the transmission of the small data is set. Therefore, the terminal station device can receive the control signal corresponding to the transmission of the small data, and can minimize the frequency of switching the on and off of the radio reception circuit, and improve the efficiency of the data communication. Further, since the small data is transmitted using the optimal radio resource set after the selection of the optimal beam, the reception quality of the small data can be improved.

[0189] In addition, in the above-described Embodiment 4, the terminal station device 200 can also transmit the small data SD using the radio resource CG during the period until the end of the response window for waiting for the reception of the MSGB, like Embodiment 3 ( Figure 11 ).

[0190] (Other Embodiments)

[0191] ​The technology common to each of the above-described embodiments will be exemplified. In each of the above-described embodiments, when small data SD that should be transmitted in the terminal device 200 is generated, the small data SD is transmitted using the radio resources CG. Here, the generation of the small data SD includes, for example, the generation of a prescribed kind of data, the size of the generated data satisfying a criterion for determining small data, and the like. Further, since the radio quality is also important, the generation of the small data SD can also include a condition such as a state in which the radio quality that enables the transmission of MSG1 and MSGA and the like is satisfied. The terminal device 200 implements communication related to the transmission of the small data SD according to the implementation state of whether or not data communication of such small data SD is generated.

[0192] From the viewpoint of power consumption, the setting method (setting 1) in which the on and off of the radio reception circuit are repeated as shown in Figure 6 Figure 9 and Figure 12 is different from the setting method (setting 2) in which the on period of the radio reception circuit is concentrated as shown in Figure 7 Figure 8 Figure 10 Figure 11 and Figure 13 In setting 1, in a case where the on and off are repeated for a long time, the power consumption becomes large at the time of the rise of the on period, and thus the power consumption becomes large compared to setting 2. However, since the monitoring of the PDCCH as a downlink control signal is not performed in the off period, there is an advantage that the power consumption can be reduced from the viewpoint of the processing of the control signal. On the other hand, in setting 2, the power consumption at the time of the rise of the on period can be reduced, and thus the power consumption becomes small compared to setting 1. However, since the monitoring of the PDCCH is performed in the on period, there is a disadvantage that the power consumption increases from the viewpoint of the processing of the control signal. In view of such advantages and disadvantages, it is preferable to separately use the settings of the on period and the off period based on setting 1 and 2.

[0193] In each of the above-described embodiments, the management of quasi-normal communication (for example, various failures) can also be performed. For example, in the communication of small data, when a transmission failure in the RLC (Radio Link Control) layer occurs and the maximum number of retransmissions reaches a prescribed threshold value, RLF (Radio Link Failure) occurs. However, in the small data communication in the RRC inactive mode, it is sometimes difficult to implement communication using optimal parameters (for example, the transmission power of the uplink, the radio resources, the transmission timing, and the like), and there is a case where the number of retransmissions in the RLC layer becomes large. Therefore, in the small data communication in the RRC inactive mode, even when the maximum number of retransmissions reaches the prescribed threshold value, it can be determined that RLF does not occur. ​​​​

[0194] In addition, in each of the above-described embodiments, the length of the time adjustment timer 311, 321, 331 should be carefully set. In a case where there is a provision that the radio resources CG are released when these time adjustment timers expire, even if the terminal station device 200 wishes to continue the transmission of small data after the expiration of the time adjustment timer, the transmission of small data becomes difficult because the radio resources CG are released. Therefore, it is preferable to set the length of the time adjustment timer to a certain degree long, enabling the continuation of the transmission of small data. However, if the length of the time adjustment timer is not set long enough, there is a possibility that the transmission of small data still becomes difficult.

[0195] As one of the methods to fundamentally solve such a situation, there is a method in which the base station device 100 periodically transmits a TA command including a TA value to the terminal station device 200, and the terminal station device 200 renews the time adjustment timer. For example, in consideration of reducing the power consumption of the terminal station device 200, in a case where the base station device 100 transmits a TA command in accordance with the period of paging, it is preferable to set the length of the above-described time adjustment timer to a length equal to or longer than the period of paging. In addition, regardless of whether or not the power consumption of the terminal station device 200 is reduced, the base station device 100 preferably transmits a TA command before the expiration of the time adjustment timer of the terminal station device 200.

[0196] In addition, each of the above-described embodiments can be appropriately combined and implemented. For example, the various timers, the contention resolution timer, and the response window described in each of the embodiments can be combined, and the interval in which the terminal station device 200 turns on the radio reception circuit to monitor the PDCCH can be set. In this case, for example, the interval in which the PDCCH is monitored can be set in accordance with the maximum or minimum of the time lengths of the various timers and the windows that are set at the same time.

[0197] Label Description

[0198] 110 network IF

[0199] 120, 220 processor

[0200] 130, 230 memory 140, 210 wireless communication unit

Claims

1. A base station device, characterized in that, The base station device has: The communication unit transmits first information relating to a first interval of a first communication corresponding to a paging communication and second information relating to a second interval of a second communication corresponding to a small data communication, and is able to perform communication when the terminal station device, which is the communication counterpart, is inactive. as well as The control unit, regarding settings related to the radio resource area for decoding control signals used to communicate with the terminal station device and the intervals where the radio resource area becomes valid, sets a first interval corresponding to the first communication and a second interval corresponding to the second communication in the communication, and can control the terminal station device to intermittently use the first interval and the second interval to perform the communication. When the terminal station device sends data corresponding to the second communication, the second communication in the second interval is started.

2. The base station device according to claim 1, characterized in that, The control unit sets the range in which the radio resource area becomes effective by sending a MIB (Master Information Block) or SIB (System Information Block) from the communication unit.

3. The base station device according to claim 1, characterized in that, The control unit sets the range in which the radio resource area becomes effective by sending dedicated control information from the RRC (Radio Resource Control) layer from the communication unit.

4. A terminal station device, characterized in that, The terminal station device has: The communication unit receives first information relating to a first interval of a first communication corresponding to a paging communication and second information relating to a second interval of a second communication corresponding to a small data communication, and is able to communicate with a base station device as a communication counterpart when in an inactive state. as well as The control unit, regarding settings related to the radio resource area for decoding control signals used in communication and the intervals where the radio resource area becomes valid, sets a first interval corresponding to the first communication and a second interval corresponding to the second communication from the base station device. The control unit is capable of controlling the intermittent use of each interval to implement the communication according to the state of the data communication. When the communication unit sends data corresponding to the second communication, the second communication in the second interval is started.

5. The terminal station device according to claim 4, characterized in that, The control unit activates the wireless receiving circuit included in the communication unit in the first interval corresponding to the periodically implemented first communication, and activates the wireless receiving circuit included in the communication unit in the second interval corresponding to the second communication containing the transmission of data.

6. The terminal station device according to claim 5, characterized in that, From the first interval corresponding to the first communication to the second interval corresponding to the second communication, the control unit continuously activates the wireless receiving circuit included in the communication unit.

7. The terminal station device according to claim 4, characterized in that, When radio resources are allocated through a random access process that includes the transmission and reception of four messages, from the first message to the fourth message, the control unit activates the radio receiving circuit included in the communication unit within a set interval after transmitting data using the radio resources.

8. The terminal station device according to claim 7, characterized in that, After the third message of the four messages is sent, the control unit starts a timer to wait for the reception of the fourth message. From the start of the timer until the set interval, the wireless receiving circuit included in the communication unit is continuously connected.

9. The terminal station device according to claim 4, characterized in that, In a random access process that includes the transmission and reception of four messages, from the first message to the fourth message, the control unit starts a timer to wait for the reception of the fourth message after the transmission of the third message. Before the timer expires, wireless resources are allocated to transmit data from the communication unit.

10. The terminal station device according to claim 4, characterized in that, When radio resources are allocated through a random access process that includes the transmission and reception of two messages, from the first message to the second message, the control unit causes the radio receiving circuit included in the communication unit to be turned on within a set interval after transmitting data using the radio resources.

11. The terminal station device according to claim 10, characterized in that, After the first message is sent, the control unit starts a timer to wait for the second message to be received, and from the start of the timer until the set interval, the wireless receiving circuit included in the communication unit is continuously connected.

12. The terminal station device according to claim 4, characterized in that, In a random access process that includes the transmission and reception of two messages, from the first message to the second message, the control unit starts a timer after the first message is sent to wait for the second message to be received. Before the timer expires, wireless resources are allocated to send data from the communication unit.

13. A wireless communication system comprising a terminal station device and a base station device, characterized in that, The base station device includes: a communication unit that transmits first information relating to a first interval of a first communication corresponding to a paging communication and second information relating to a second interval of a second communication corresponding to a small data communication, and is capable of performing communication when the terminal station device is inactive; and a control unit that sets the first interval corresponding to the first communication and the second interval corresponding to the second communication in the communication, based on settings relating to a radio resource area for decoding control signals for performing communication with the terminal station device and an interval in which the radio resource area becomes valid, and controls the terminal station device to intermittently use the first interval and the second interval to perform the communication. When the terminal station device sends data corresponding to the second communication, the second communication in the second interval is started.

14. A wireless communication method, wherein the wireless communication method is a wireless communication method executed by a base station device having a communication unit and a control unit, characterized in that, The wireless communication method has the following processing: The system transmits first information relating to a first interval of a first communication corresponding to a paging communication and second information relating to a second interval of a second communication corresponding to a small data communication, and performs communication when the terminal station device, which is the communication counterpart of the base station device, is in an inactive state. Regarding the settings related to the radio resource area for decoding control signals used to communicate with the terminal station device and the intervals where the radio resource area becomes valid, a first interval corresponding to the first communication and a second interval corresponding to the second communication are set, and control is implemented to make the terminal station device intermittently use the first interval and the second interval to perform the communication. When the terminal station device sends data corresponding to the second communication, control is initiated to use the second communication in the second interval.

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