Wireless communication device and second wireless communication device

Abstract

A wireless communication device capable of performing a first type of data communication for transmitting and receiving a first type of data with a counterpart wireless communication device in a first mode, the wireless communication device being provided with a control unit capable of performing a communication control in which the first type of data is transmitted to and received from the counterpart wireless communication device in the first mode. And a controller configured to receive a first control signal transmitted from the counterpart wireless communication device in a first communication range, identify the counterpart wireless communication device when a second control signal transmitted from the counterpart wireless communication device is received in a second communication range, and continue the first type of data communication in the second communication range.

Description

Technical Field

[0001] The present invention relates to a wireless communication device and a second wireless communication device. Background Art

[0002] A terminal device in a wireless communication system has multiple states defined in connection with a base station device. For example, the terminal device has an RRC_INACTIVE state (temporarily stopped state) in addition to an RRC_CONNECTED state (communication state) and an RRC_IDLE state (unconnected state).

[0003] The terminal device saves power by turning off the wireless unit in the RRC_INACTIVE state. In the RRC_INACTIVE state, the terminal device turns on the wireless unit, for example, at the timing of receiving a paging (for example, RAN paging), and receives the paging. Paging is a message to call the terminal device. In addition, when the terminal device turns on the wireless unit for paging reception, the timing of turning on the wireless unit is collected by measuring, thereby suppressing the power consumption caused by turning on / off the wireless unit.

[0004] For example, when movement occurs in the RRC_INACTIVE state, the terminal device performs cell reselection. Cell reselection is, for example, a process of measuring a signal of a cell other than the cell (serving cell) in which the terminal device is located and moving to a more suitable cell.

[0005] The following prior art documents describe technologies related to cell reselection of terminal devices.

[0006] Prior art literature

[0007] Non-patent literature

[0008] Non-patent document 1: 3GPP (registered trademark) TS36.133 LTE-A wireless measurement standard

[0009] Non-patent document 2: 3GPP TS36.300 LTE-A Profile Standard

[0010] Non-patent document 3: 3GPP TS36.211 LTE-A PHY channel standard

[0011] Non-patent document 4: 3GPP TS36.212 LTE-A PHY coding standard

[0012] Non-patent document 5: 3GPP TS36.213 LTE-A PHY process standard

[0013] Non-patent document 6: 3GPP TS36.214 LTE-A PHY measurement standard

[0014] Non-patent document 7: 3GPP TS36.321 LTE-A MAC standard

[0015] Non-patent document 8: 3GPP TS36.322 LTE-A RLC standard

[0016] Non-patent document 9: 3GPP TS36.323 LTE-A PDCP standard

[0017] Non-patent document 10: 3GPP TS36.331 LTE-A RRC standard

[0018] Non-patent document 11: 3GPP TS36.413 LTE-A S1 standard

[0019] Non-patent document 12: 3GPP TS36.423 LTE-A X2 standard

[0020] Non-patent document 13: 3GPP TS36.425 LTE-A Xn standard

[0021] Non-Patent Document 14: 3GPP TR36.912 NR Radio Access Overview

[0022] Non-Patent Document 15: 3GPP TR38.913 NR Request Conditions

[0023] Non-Patent Document 16: 3GPP TR38.913 NR Request Conditions

[0024] Non-Patent Literature 17: 3GPP TR38.801 NR Network Architecture Overview

[0025] Non-Patent Literature 18: 3GPP TR38.802 NR PHY Overview

[0026] Non-Patent Document 19: 3GPP TR38.803 NR RF Overview

[0027] Non-Patent Document 20: 3GPP TR38.804 NR L2 Overview

[0028] Non-Patent Document 21: 3GPP TR38.900 NR High Frequency Overview

[0029] Non-patent document 22: 3GPP TS38.300 NR overview standard

[0030] Non-patent document 23: 3GPP TS37.340 NR multiple access profile standard

[0031] Non-Patent Document 24: 3GPP TS38.201 NR PHY Standard Overview

[0032] Non-patent document 25: 3GPP TS38.202 NR PHY service profile standard

[0033] Non-patent document 26: 3GPP TS38.211 NR PHY channel standard

[0034] Non-patent document 27: 3GPP TS38.212 NR PHY coding standard

[0035] Non-patent document 28: 3GPP TS38.213 NR PHY data channel procedure standard

[0036] Non-patent document 29: 3GPP TS38.214 NR PHY control channel procedure standard

[0037] Non-patent document 30: 3GPP TS38.215 NR PHY measurement standard

[0038] Non-patent document 31: 3GPP TS38.321 NR MAC standard

[0039] Non-patent document 32: 3GPP TS38.322 NR RLC standard

[0040] Non-patent document 33: 3GPP TS38.323 NR PDCP standard

[0041] Non-patent document 34: 3GPP TS37.324 NR SDAP standard

[0042] Non-patent document 35: 3GPP TS38.331 NR RRC standard

[0043] Non-patent document 36: 3GPP TS38.401 NR architecture overview standard

[0044] Non-patent document 37: 3GPP TS38.410 NR core network overview standard

[0045] Non-patent document 38: 3GPP TS38.413 NR core network AP standard

[0046] Non-patent document 39: 3GPP TS38.420 NR Xn interface overview standard

[0047] Non-patent document 40: 3GPP TS38.423 NR XnAP standard

[0048] Non-patent document 41: 3GPP TS38.470 NR F1 interface overview standard

[0049] Non-patent document 42: 3GPP TS38.473 NR F1AP standard Summary of the invention

[0050] Problems to be solved by the invention

[0051] On the other hand, the terminal device sometimes performs small data transmission (SDT) with the base station device in the RRC_INACTIVE state. If the terminal device moves during SDT communication and performs cell reselection, it may be impossible to transmit or receive small data, or it may take time to transmit and receive small data, and the service based on SDT cannot be continued.

[0052] Therefore, the present invention provides a wireless communication device and a second wireless communication device that efficiently perform small data transmission and reception during movement in the RRC_INACTIVE state.

[0053] Means for solving problems

[0054] A wireless communication device capable of performing a first type of data communication of sending and receiving a first type of data with a counterpart wireless communication device in a first mode, the wireless communication device comprising a control unit capable of implementing the following communication control: in the first mode, receiving a first control signal sent from the counterpart wireless communication device within a first communication range, and when receiving a second control signal sent from the counterpart wireless communication device within a second communication range, identifying the counterpart wireless communication device, and continuing the first type of data communication within the second communication range.

[0055] Effects of the Invention

[0056] The present invention can efficiently perform small data transmission and reception in cell reselection in the RRC_INACTIVE state. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 1 is a diagram showing an example of wireless communication in the wireless communication system 1 .

[0058] Figure 2 It is a diagram showing a configuration example of the wireless communication system 10 .

[0059] Figure 3 It is a diagram showing a configuration example of the terminal device 100 .

[0060] Figure 4 It is a diagram showing a configuration example of the base station apparatus 200 .

[0061] Figure 5 This is a diagram showing an example of a sequence of the first embodiment.

[0062] Figure 6 This is a diagram showing an example of a sequence of downlink data transmission in a cell update (Cell Update) mode.

[0063] Figure 7 This is a diagram showing an example of a sequence of uplink data transmission in a cell update method.

[0064] Figure 8 This is a diagram showing an example of a transmission trigger for a cell update.

[0065] Fig. 9 This is a diagram showing an example of a selection criterion for a new cell used for cell reselection.

[0066] Fig.10 This is a diagram showing an example of the timer value of the SDT Failure Timer.

[0067] Fig.11 This is a diagram showing an example of the maximum number of RLC retransmissions.

[0068] Fig.12 This is a diagram showing an example of a resume reason (ResumeCause).

[0069] Fig.13 This is a diagram showing an example of the sequence of SDT in UE-specific RNA (UE-specific RNA).

[0070] Fig.14 This is a diagram showing an example of the sequence of SDT in the UE-specific RNA.

[0071] Fig.15 It is a diagram showing an example of a restoration reason. DETAILED DESCRIPTION

[0072] [First embodiment]

[0073] The wireless communication system 1 includes wireless communication devices 3-1 and 2 and a counterpart wireless communication device 2. The wireless communication devices 3-1 and 2 and the counterpart wireless communication device 2 are wirelessly connected to each other and transmit and receive data wirelessly. The wireless communication devices 3-1 and 2 and the counterpart wireless communication device 2 correspond to a first type of data communication in which a first type of data is transmitted and received in a first mode.

[0074] The wireless communication devices 3-1, 2 and the counterpart wireless communication device 2 each have a processor. The processor executes the programs stored in the wireless communication devices 3-1, 2 and the counterpart wireless communication device 2 to construct the control units 5-1, 2 and the second control unit 4. The processing performed by the wireless communication devices 3-1, 2 described below can also be understood as being performed by the control units 5-1, 2. In addition, the processing performed by the counterpart wireless communication device 2 described below can also be understood as being performed by the second control unit 4.

[0075] The first mode is a mode in which the first type of data can be transmitted and received at a predetermined timing. In the first mode, the counterpart wireless communication device 2 turns on the wireless unit at a predetermined timing, for example, to be in a state in which a signal (message, channel) can be received.

[0076] Figure 1 This is a diagram showing an example of communication control of the first type of data communication in the wireless communication system 1. The wireless communication devices 3-1 and 2 can perform communication control to continue the first type of data communication. The wireless communication device 3-1 has a communication area C1 indicating a range in which communication is possible. In addition, the wireless communication device 3-2 has a communication area C2 indicating a range in which communication is possible. Hereinafter, the communication area C1 is sometimes referred to as the first communication range C1, and the communication area C2 is sometimes referred to as the second communication range C2.

[0077] The counterpart wireless communication device 2 is in the first mode, is located within the first communication range C1, and performs the first type of data communication with the wireless communication device 3-1 (S1).

[0078] The counterpart wireless communication device 2 moves, for example, in the direction of arrow D1. The counterpart wireless communication device 2 searches for a new communication area at a certain timing. Then, the counterpart terminal device 2 decides to change (move) the cell in which communication is to be performed from the first communication range C1 to the second communication range C2.

[0079] When changing the communication range, the counterpart wireless communication device 2 transmits a first control signal to the wireless communication device 3-1 in the first communication range C1 (S2). When the wireless communication device 3-1 receives the first control signal (S2), it stops, for example, transmitting and receiving data in the first data communication.

[0080] When the communication range is changed, the other wireless communication device 2 sends a second control signal to the wireless communication device 3-2 in the second communication range C2 (S3). When the wireless communication device 3-2 receives the second control signal (S3), it identifies the other wireless communication device 2 (identifies that the other wireless communication device 2 has moved to the second communication range C2) and performs the first type of data communication in the second communication range C2 (S4). As a result, the wireless communication device 3-2 can continue the first type of data communication in the second communication range C2.

[0081] Furthermore, when the wireless communication device has a plurality of communication ranges, the wireless communication devices 3 - 1 and 2 may be a single wireless communication device.

[0082] [Second Embodiment] A second embodiment is described.

[0083] <About Wireless Communication System 10>

[0084] Figure 2 1 is a diagram showing a configuration example of a wireless communication system 10. The wireless communication system 10 includes base station devices 200-1 and 2 and a terminal device 100. The wireless communication system 10 is, for example, a wireless communication system corresponding to uplink and downlink SDT in the RRC_INACTIVE state. Small data refers to data of a predetermined size or less, for example. In addition, the predetermined size is set to a size that can be transmitted in the manner shown below (for example, a size corresponding to a channel size, a wireless frame size, etc.).

[0085] The terminal device 100 is a communication device that wirelessly connects to the base station device 200-1 or 2 to transmit and receive data, and is, for example, a smartphone or a tablet terminal. Figure 2 In the figure, there is one terminal device 100, but there may be multiple terminal devices.

[0086] Base station devices 200-1, 2 (hereinafter sometimes referred to as base station devices 200) correspond to various communication generations (e.g., 5G, post-5G, etc.), for example. In addition, base station device 200 may be composed of one unit, or may be composed of a plurality of units such as CU (Central Unit), DU (Distributed Unit), and RU (Radio Unit).

[0087] Furthermore, the base station apparatuses 200-1 and 2 respectively have communication areas (cells) C200-1 and 2. The communication area is, for example, a range in which wireless communication with the terminal apparatus 100 is possible.

[0088] The terminal device 100 is wirelessly connected to the base station device 200-1 and performs wireless communication W101. Then, the terminal device 100 ends the communication, performs a predetermined sequence, and transitions to the RRC_INACTIVE state.

[0089] The terminal device 100 moves, for example, in the direction of arrow D100. Then, the terminal device 100 receives a signal from a cell (cell C200-2) other than the serving cell (cell C200-1) at a certain timing and measures the radio wave state. When the measurement result satisfies a predetermined condition, the terminal device 100 performs cell reselection on the measured cell.

[0090] In the following description, unless otherwise specified, the terminal device 100 performs cell reselection from the base station device 200-1 to the base station device 200-2. In addition, when the base station device 200 includes a plurality of DUs and RUs and has a plurality of cells, the terminal device 100 may perform cell reselection and select a different cell in the same base station device 200. When cell reselection is performed and a different cell in the same base station device 200 is selected, the base station device 200-1 (the base station device before the movement) and the base station device 200-2 (the base station device after the movement) in the subsequent sequence may be replaced by the cell before the movement and the cell after the movement, respectively.

[0091] <Configuration Example of Terminal Device 100>

[0092] Figure 3 1 is a diagram showing a configuration example of a terminal device 100 . The terminal device 100 includes a CPU (Central Processing Unit) 110 , a storage device 120 , a memory 130 , a wireless communication circuit 150 , and an antenna 151 .

[0093] The storage device 120 is an auxiliary storage device such as a flash memory, a HDD (Hard Disk Drive), or an SSD (Solid State Drive) that stores programs and data. The storage device 120 stores a terminal communication program 121 and a terminal side small data communication program 122 .

[0094] The memory 130 is an area for loading programs stored in the storage device 120. In addition, the memory 130 can also be used as an area for storing data of the program.

[0095] The wireless communication circuit 150 is a device that performs wireless communication with the base station device 200 and other terminal devices 100. The wireless communication circuit 150 includes an antenna 151. The antenna 151 includes, for example, a directional antenna that can control the transmission and reception direction of radio waves.

[0096] The CPU 110 is a processor that loads a program stored in the storage device 120 into the memory 130 , executes the loaded program, constructs each unit, and implements each process.

[0097] The CPU 110 constructs a second communication unit by executing the terminal communication program 121, and performs terminal communication processing. The terminal communication processing is processing for wirelessly connecting to the base station device 200 and other terminal devices 100 and performing wireless communication.

[0098] The CPU 110 constructs a second control unit and performs a terminal side small data communication process by executing the terminal side small data communication program 122. The terminal side small data communication process is a process for controlling the transmission and reception of small data between the terminal device 100 in the RRC_INACTIVE state and the base station device 200 in the terminal device 100.

[0099] <Configuration Example of Base Station Apparatus 200>

[0100] Figure 4 2 is a diagram showing a configuration example of the base station device 200. The base station device 200 includes a CPU 210, a storage device 220, a memory 230, a wireless communication circuit 250, and an antenna 251.

[0101] The storage device 220 is an auxiliary storage device such as a flash memory, HDD, or SSD that stores programs and data. The storage device 220 stores a base station communication program 221 and a base station side small data communication program 222 .

[0102] The memory 230 is an area for loading programs stored in the storage device 220. In addition, the memory 230 can also be used as an area for storing data of the program.

[0103] The wireless communication circuit 250 is a device that performs wireless communication with the terminal device 100. The wireless communication circuit 250 includes an antenna 251. The antenna 251 includes, for example, a directional antenna that can control the transmission and reception direction of radio waves.

[0104] The CPU 210 is a processor that loads a program stored in the storage device 220 into the memory 230 and executes the loaded program to construct each unit and realize each process.

[0105] The CPU 210 constructs a communication unit and performs communication processing by executing the base station communication program 221. The base station communication processing is processing for wireless communication with the terminal device 100. In the base station communication processing, the base station device 200 is wirelessly connected to the terminal device 100, and transmits data and control signals to the terminal device 100 or receives data from the terminal device 100.

[0106] The CPU 210 constructs a control unit by executing the base station side small data communication program 222 to perform base station side small data communication processing. The base station side small data communication processing is a process for controlling the transmission and reception of small data between the base station apparatus 100 and the base station apparatus 200 in the RRC_INACTIVE state.

[0107] <SDT during cell reselection>

[0108] Hereinafter, an example of a processing method when cell reselection is performed during SDT or when small data occurs will be described. In addition, data in the following description means small data unless otherwise specified.

[0109] <1. First Method>

[0110] Figure 5 1 is a diagram showing an example of a sequence of the first embodiment. The first embodiment is a method of performing uplink and downlink SDT while waiting for the timing of transmitting a paging to the terminal device 100 .

[0111] exist Figure 5 In the figure, base station devices 200-1 (gNB1) and 2 (gNB2) belong to RNA1 which is the same RNA (RAN Notification Area). In addition, terminal device 100 is in RRC_INACTIVE state. In the following figures, the RNA to which base station devices 200-1 and 2 belong and the state of terminal device 100 are also the same. Figure 5 same.

[0112] Uplink data is generated in the terminal device 100 (UE) (S10). Then, the terminal device 100 performs cell reselection before transmitting the uplink data (S11).

[0113] On the other hand, downlink data is generated in the base station device 200-1 (S12). At this timing, the terminal device 100 is located in the cell of the base station device 200-2 by cell reselection.

[0114] The base station devices 200-1 and 2 transmit paging (RAN paging) (S13 and S14) to transmit downlink data to the terminal device 100. Since RAN paging is performed on the entire RNA, both base station devices 200-1 and 2 belonging to the same RNA transmit paging.

[0115] The terminal device 100 receives the paging of the base station device 200 - 2 , and transmits an RRC resume request (RRC Resume Request) for downlink data transmission to the base station device 200 - 2 ( S15 ).

[0116] Furthermore, the terminal apparatus 100 receives the paging of the base station apparatus 200 - 2 , and transmits an RRC recovery request including uplink data to the base station apparatus 200 - 2 ( S16 ).

[0117] When receiving the RRC recovery request for downlink data transmission, the base station device 200-2 transmits a data request (Data Request) to the base station device 200-1 before the movement based on the cell reselection (S17). When receiving the data request, the base station device 200-1 includes the unsent downlink data in the data response (Data Forwarding) and transmits it to the base station device 200-2 (S18).

[0118] The base station apparatus 200-2 includes the downlink data in the DL-CCCH and transmits it to the terminal apparatus 100 (S19). The terminal apparatus 100 includes the uplink data (or ACK) in the UL-CCCH and transmits it to the base station apparatus 200-2.

[0119] DL-CCCH is, for example, an example of a message (channel) for sending small data to a terminal device 100 in the RRC_INACTIVE state. In addition, UL-CCCH is an example of a message (channel) for sending small data from a terminal device 100 in the RRC_INACTIVE state. UL-CCCH is, for example, an RRC recovery request. In subsequent figures, DL-CCCH and UL-CCCH are the same unless otherwise specified.

[0120] <2.Cell Update Method>

[0121] Figure 6 The figure shows an example of a sequence of downlink data transmission in a cell update method. The cell update method is a method of performing a process equivalent to cell update on a terminal device 100 that is performing or about to perform SDT. Parameters (related information) of the cell update method are set, for example, by an RRC message when setting SDT.

[0122] The base station device 200-1 generates downlink data 1 (S21). The base station device 200-1 includes the downlink data 1 in a channel for transmitting downlink small data (for example, DL-CCCH, the same below), and transmits the downlink data 1 to the terminal device 100 (S22).

[0123] The terminal device 100 receives downlink data 1 (S22), and transmits ACK1 (S24) confirming reception of downlink data 1. However, cell reselection occurs (S23), and the terminal device 100 fails to transmit ACK1 (or does not transmit ACK1) (S25).

[0124] Furthermore, the base station device 200 - 1 fails to transmit the downlink data 2 after the cell reselection ( S26 ).

[0125] The terminal device 100 transmits a cell update to the base station device 200-1 (S27). When receiving the cell update, the base station device 200-1 recognizes that the terminal device 100 has performed a cell reselection (recognizes the terminal device 100), and stops the SDT for the terminal device 100. When receiving the cell update, the base station device 200-1 does not transmit to the terminal device 100, for example, even if there is accumulated data (including ACK) that has not been transmitted (not transmitted, or ACK for transmission has not been received).

[0126] On the other hand, the terminal apparatus 100 transmits an RRC recovery request to the base station apparatus 200 - 2 in order to transmit ACK1 to the base station apparatus 200 - 2 ( S28 ).

[0127] When the base station device 200-2 receives the RRC recovery request, it sends a data request to the base station device 200-1 before the movement based on the cell reselection (S29). When the base station device 200-1 receives the data request, it includes the downlink data 1 and 2 in the data response and sends it to the base station device 200-2 (S30). In addition, since the base station device 200-1 does not receive the ACK1 for the downlink data 1, it recognizes that the downlink data 1 is also in the unsent state, so both the downlink data 1 and 2 become the data to be sent.

[0128] The base station 200-2 includes downlink data 1 and 2 in the DL-CCCH and transmits them to the terminal 100 (S31). The terminal 100 includes ACK1 and ACK2 indicating reception of downlink data 2 in the UL-CCCH and transmits them to the base station 200-2 (S32).

[0129] Furthermore, in the case of cell reselection in which a different cell in the same base station apparatus 200 is selected, the data request and the data response may be omitted.

[0130] Figure 7 1 is a diagram showing an example of a sequence of uplink data transmission in a cell update method. The terminal device 100 includes uplink data 1 in the UL-CCCH and transmits the uplink data 1 to the base station device 200-1 (S41). Then, the terminal device 100 performs cell reselection (S42).

[0131] The base station apparatus 200 - 1 receives the uplink data 1 ( S41 ), and attempts to transmit ACK1 indicating reception of the uplink data 1 to the terminal apparatus 100 , but fails to transmit the ACK1 because the cell is reselected ( S43 ).

[0132] The terminal device 100 transmits a cell update to the base station device 200-1 (S44). As a result, the communication between the terminal device 100 and the base station device 200-1 is temporarily interrupted.

[0133] On the other hand, the terminal apparatus 100 transmits an RRC recovery request to the base station apparatus 200 - 2 in order to receive ACK1 from the base station apparatus 200 - 2 ( S45 ).

[0134] When the base station device 200-2 receives the RRC recovery request, it sends a data request to the base station device 200-1 before the movement based on the cell reselection (S46). When the base station device 200-1 receives the data request, it includes ACK1 in the data response and sends it to the base station device 200-2 (S47). In addition, the base station device 200-1 receives the cell update after sending ACK1, so it can recognize that the ACK1 has not arrived at the terminal device 100 (it is possible that it has not arrived).

[0135] The base station device 200-2 includes ACK1 in the DL-CCCH and transmits it to the terminal device 100 (S48). The terminal device 100 receives ACK1 (S48) and recognizes that the transmission of the uplink data 1 is successful.

[0136] The terminal device 100 includes uplink data 2 generated later in the UL-CCCH and transmits it to the base station device 200-2 (S49). The base station device 200-2 includes ACK2 indicating that the uplink data 2 has been received in the DL-CCCH and transmits it to the terminal device 100 (S50).

[0137] The cell update method uses the cell update procedure, and can perform uplink and downlink small data transmission and reception without executing paging on all base station devices in RNA as in the first method.

[0138] <About community updates>

[0139] The cell update used in the cell update method is described. The cell update is defined as, for example, "Cause = Cell Update" of "RRC Recovery Request" transmitted via CCCH. In addition, for the RRC Recovery Request, subsequent RRC release may not occur. In addition, for example, "Cause = Cell Update" of "UE Assistance Information" transmitted via DCCH is defined.

[0140] <1. Event trigger>

[0141] The opportunity for sending cell updates is explained. Figure 8 This is a diagram showing an example of a transmission trigger for a cell update.

[0142] <1.1 Sending opportunity 1 (case (1))>

[0143] Transmission trigger 1 is the timing of the expiration of the SDT failure timer. The terminal device 100 starts the timer (S60) when receiving the RRC release (RRCRelease), and transmits the cell update (Cell Update) (S70) when the time expires. The terminal device 100 maintains the RRC_INACTIVE state (does not transition to the RRC_IDLE state) and continues to perform cell reselection.

[0144] <1.2 Sending opportunity 2 (cases of (2)-1 and (2)-2)>

[0145] The transmission trigger 2 is the timing when a transmission failure (reaching the number of retransmissions) in RLC (Radio Link Control) AM (Acknowledged Mode) is detected. The transmission trigger 2 is a transmission trigger that occurs when communication is performed in the AM mode.

[0146] In the case of downlink SDT, the terminal device 100 counts the number of times the corresponding ACK is transmitted ( S61 ), and transmits a cell update when it detects that a predetermined number of transmissions have been made ( S70 ).

[0147] In the case of uplink SDT, the terminal device 100 counts the number of uplink data transmissions (S62), and transmits a cell update (Cell Update) when a predetermined number of transmissions are detected (S70). The terminal device 100 maintains the RRC_INACTIVE state (does not transition to the RRC_IDLE state) and continues to perform cell reselection.

[0148] <1.3 Sending opportunity 3 (case (3))>

[0149] Transmission trigger 3 is when a cell reselection criterion is satisfied. The request condition in the cell reselection criterion complies with TS38.304 / TS38.133, for example.

[0150] <2. Delivery conditions>

[0151] The terminal device 100 can perform cell reselection while the signal level of the serving cell is good so that the cell update (Cell Update) reaches the connected cell (serving cell: the base station device 200 before cell reselection).

[0152] The base station device 200 introduces a new threshold value, for example, in order to particularly shorten the time of camping (movement caused by cell reselection) to a low priority, and notifies the terminal device 100 through RRC Release. In addition, when the terminal device 100 camps on a high priority, it is not determined whether the signal level of the serving cell is low, so a new threshold value may not be set.

[0153] Fig. 9 This is a diagram showing an example of a selection criterion for a new cell in cell reselection. Fig. 9 Examples of various cell reselections (intra-frequency reselection, inter-frequency reselection, and inter-RAT reselection) are shown. Fig. 9 In (1) and (2) of the inter-frequency reselection to the lower priority level (for the lower frequency priority), the underlined conditions are set. (1) and (2) respectively newly define the radio quality threshold (Thresh SDT，LowQ ) and the receiving level threshold (Thresh SDT，LowP ). The radio quality threshold for SDT is a value higher (better) than the radio quality threshold in normal cell reselection. In addition, the reception level threshold for SDT is a value higher than the radio quality threshold in normal cell reselection. Therefore, the terminal device 100 can perform cell reselection during a period when the radio wave state of the connected cell is in a better state than the normal cell reselection, and the cell update becomes easier to reach.

[0154] In addition, Fig. 9 In the embodiment, the selection criterion in the inter-RAT reselection is set in the same way as the selection criterion in the inter-frequency reselection.

[0155] <3.SDT Failure Timer>

[0156] Fig.10 This is a diagram showing an example of a timer value of an SDT failure timer. When the SDT failure timer is used as a trigger for sending a cell update, the terminal device 100 can use, for example, a value of T319. In addition, when the SDT failure timer is used as a trigger for sending a cell update, for example, the terminal device 100 can use a value set based on the value (range) of T319 as the timer value.

[0157] <4. Maximum number of RLC retransmissions>

[0158] Fig.111 is a diagram showing an example of the maximum number of RLC retransmissions. When the terminal device 100 uses the maximum number of RLC retransmissions as a trigger for sending a cell update, the existing value of the maximum number of RLC retransmissions may be used. In addition, when the terminal device 100 uses the maximum number of RLC retransmissions as a trigger for sending a cell update, the value set based on the existing value of the maximum number of RLC retransmissions may be used as the maximum number of RLC retransmissions.

[0159] <5.ASN.1>

[0160] Fig.12 is a diagram showing an example of ResumeCause (resumption reason). Fig.12 In the example, "cell-Update" is added to ResumeCause. In addition, when a new reason is added to the recovery reason, the name may be "cna-Update (Cell-based Notification Area Update)", "sdt-Access", etc. in addition to "cell-Update". As mentioned above, the recovery reason can be sent via "RRC recovery request" or "UE auxiliary information".

[0161] [Third Embodiment]

[0162] The third embodiment is described. In the third embodiment, a new RNA corresponding to SDT is defined. Hereinafter, the RNA for SDT is referred to as, for example, UE-specific RNA.

[0163] Fig.13 This is a diagram showing an example of the sequence of SDT in the UE-specific RNA. Fig.13 In the example, base station apparatus 200-1 and base station apparatus 200-2 belong to the same RNA. In addition, base station apparatuses 200-1 and 2 are structures that connect multiple DUs and RUs to a CU, and have multiple cells. Base station apparatus 200-1 has cell 1 and cell 2, and base station apparatus 200-2 has cell 3 and cell 4. The UE-specific RNA is composed of multiple cells in the same base station apparatus, for example. Fig.13 Cell 1 and cell 2 form a UE-specific RNA. Fig.13 In FIG. 1 , it is assumed that the terminal device 100 performs cell reselection from cell 1 to cell 3.

[0164] When downlink data is generated, the base station apparatus 200 - 1 transmits paging for downlink data transmission (implementation of SDT) to the terminal apparatus 100 in the RRC_INACTIVE state in the cell 1 and the cell 2 of the same UE-specific RNA ( S80 , S81 ).

[0165] Paging other than paging for implementing SDT is sent in units of RNA, so paging is sent in cells 1 to 4. On the other hand, in the present embodiment, paging for implementing SDT is sent in units of UE-specific RNA, so as shown in Fig.13 , paging is sent in cells 1 and 2, and no paging is sent in cells 3 and 4. Thus, the wireless communication system 10 can reduce the transmission of paging and can suppress the signal transmission amount of the entire system.

[0166] Since the terminal device 100 has moved and cell reselection has occurred to cell 3, it sends an RRC resume request (S82) to the base station device 200-2 (cell 3). When the base station device 200-2 receives the RRC resume request, it sends a data request (S83) to the base station device 200-1 before the movement based on cell reselection. When the base station device 200-1 receives the data request, it includes the downlink data in the response and sends it to the base station device 200-2 (S84). The base station device 200-1 (cell 3) includes the downlink data in the DL-CCCH and sends it to the terminal device 100 (S85).

[0167] Fig.14 is a diagram showing an example of the sequence of SDT in UE-specific RNA. In the example of Fig.14 , before paging for implementing SDT is performed, downlink data is sent using the DL-CCCH, and when an ACK cannot be received, paging for implementing SDT is sent.

[0168] When the base station device 200-1 has downlink data, it includes the downlink data in the DL-CCCH and sends it to the terminal device 100 in the RRC_INACTIVE state (S91). Then, when the base station device 200-1 cannot receive an ACK within a specified time (when the arrival confirmation of the data cannot be recognized) (S92), it sends paging for downlink data transmission (implementing SDT) in cells 1 and 2 of the same UE-specific RNA (S93, S94).

[0169] After that, the processing S95 to S98 is the same as the processing S82 to S85 in Fig.13 . In addition, the terminal device 100 can also send an ACK to the base station device 200-1 when it has obtained data during the reception of the DL-CCCH. In this case, since paging for implementing SDT is not sent, the signal transmission amount of the entire system can be suppressed.

[0170] <RRC Resume Request>

[0171] The RRC resume request in UE-specific RNA is described. The RRC resume request can define a new cause associated with the UE-specific RNA. Fig.15 is a diagram showing an example of a recovery reason. Fig.15 In the example, rna-UpdateDedicated (underlined part) is newly added. In addition, when a new reason is added to the recovery reason, the name may be "sna-Update (SDT-based Notification AreaUpdate)", "sna-UpdatDedicated" or the like in addition to "rna-UpdateDedicated".

[0172] [Other embodiments]

[0173] The elements described in the first to third embodiments and other embodiments may be combined respectively. In addition, the elements described in the first to third embodiments and other embodiments may be used separately according to, for example, the wireless state, system requirements, etc.

[0174] In addition, the names of messages, channels, etc. in each embodiment are not limited to the names in the embodiments. The messages and channels can be sent and received at the timing and state in each embodiment and can record the required information, and are not particularly limited to the messages and channels used in the embodiments.

[0175] Description of Reference Numerals

[0176] 1: Wireless communication system

[0177] 2: The other party's wireless communication device

[0178] 3: Wireless communication device

[0179] 10: Wireless communication system

[0180] 100: Terminal device

[0181] 110:CPU

[0182] 120: Storage device

[0183] 121: Terminal communication program

[0184] 122: Small data communication program on the terminal side

[0185] 130: Memory

[0186] 150: Wireless communication circuit

[0187] 151: Antenna

[0188] 200: Base station device

[0189] 210:CPU

[0190] 220: Storage device

[0191] 221: Base station communication program

[0192] 222: Small data communication program on the base station side

[0193] 230: Memory

[0194] 250: Wireless communication circuit

[0195] 251: Antenna

Claims

1. A wireless communication device capable of performing a first type of data communication of sending and receiving a first type of data with a counterpart wireless communication device in a first mode, wherein: The wireless communication device has a control unit, which can implement the following communication control: in the first mode, a first control signal sent from the other party's wireless communication device is received within a first communication range, and when a second control signal sent from the other party's wireless communication device is received within a second communication range, the other party's wireless communication device is identified, and the first type of data communication is continued within the second communication range.

2. The wireless communication device according to claim 1, wherein: When a first condition is satisfied, the first control signal is transmitted from the counterpart wireless communication device.

3. The wireless communication device according to claim 2, wherein: The first condition includes at least one of expiration of a timer related to control of the first type of data communication, the number of retransmissions of the first type of data reaching a first number, and a condition related to a change in the communication range of the counterpart wireless communication device.

4. The wireless communication device according to claim 1, wherein: The first mode is a state in which the counterpart wireless communication device can receive the first type of data at a predetermined timing. The first type of data is data smaller than a specified size.

5. The wireless communication device according to claim 4, wherein: The first mode is the RRC-INACTIVE state.

6. The wireless communication device according to claim 1, wherein: When receiving the first control signal, the control unit stops transmitting the first type of data in the first communication range.

7. The wireless communication device according to claim 1, wherein: When receiving the second control signal, the control unit transmits the first type of data that has not yet been transmitted to the counterpart wireless communication device within the second communication range.

8. The wireless communication device according to claim 1, wherein: The first control signal is a cell update.

9. The wireless communication device according to claim 1, wherein: The second control signal is an RRC resume request.

10. A second wireless communication device capable of performing a first type of data communication in a first mode to send and receive first type of data with a counterpart wireless communication device, wherein: The second wireless communication device has a control unit, which can, in the first mode, send a first control signal to the other wireless communication device within the first communication range, and send a second control signal to the other wireless communication device within the second communication range, so that the other wireless communication device can recognize the second wireless communication device and continue the first data communication within the second communication range.

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