Terminal device and base station device

Abstract

The disclosed technology improves the efficiency of a wireless access from terminal device to a second cell in a wireless communication system in which the second cell is provided in a wireless cell. This terminal device is used in a wireless communication system including a first base station that provides a first cell and a second base station that provides a second cell. The terminal device comprises a first communication control unit and a second communication control unit. The first communication control unit waits for third information related to communication with the second cell, which information is transmitted from the second base station, by using first information received from the first base station or second information received from the second base station. The second communication control unit executes an access procedure for transmitting, to the second base station, a request signal requesting the third information, and receiving a response corresponding to the request signal. When the first communication control unit acquires the third information before the second communication control unit receives the response, the second communication control unit stops the access procedure.

Description

Terminal device and base station device

[0001] The present invention relates to a terminal device, a base station device, and a wireless communication system for wireless communication.

[0002] The 3GPP (registered trademark) (3rd Generation Partnership Project) is studying a wireless communication system in which a Network Energy Saving (NES) cell is set within a wireless communication cell (cell A) to distribute the load of cell A. In such a wireless communication system, a terminal device (UE: User Equipment) in IDLE / INACTIVE mode transmits a wake-up signal (WUS) to the NES cell and acquires control information from the NES cell. The terminal device then camps on the NES cell according to the acquired control information. This procedure is proposed, for example, in Non-Patent Documents 1 and 2. The physical layer for the control information is described, for example, in Non-Patent Document 3. The UE procedure in IDLE / INACTIVE mode is described, for example, in Non-Patent Document 4. The MAC protocol of a radio access network is described, for example, in Non-Patent Document 5. The RRC protocol of a radio access network is described, for example, in Non-Patent Document 6.

[0003] 3GPP TSG-RAN WG2 Meeting #125bis, R2-2403731, Report from session on V2X / SL, R19 NES and MOB3GPP TSG-RAN WG2 Meeting #126, R2-2405701, Report from session on V2X / SL, R19 NES and MOB3GPP TS38.213 V18.2.0 (2024 / 06)3GPP TS38.304 V18.2.0 (2024 / 06)3GPP TS38.321 V18.2.0 (2024 / 06)3GPP TS38.331 V18.2.0 (2024 / 06)

[0004] However, the proposed procedure may result in low efficiency of wireless access from a terminal device to an NES cell. For example, when multiple terminal devices simultaneously transmit wake-up signals to an NES cell, the base station device providing the NES cell transmits a response to each wake-up signal. Therefore, it takes a long time for the terminal device to acquire control information from the NES cell, and in some cases, the terminal device may not be able to acquire the control information. Furthermore, the power saving effect of the NES cell may be reduced.

[0005] An object of one aspect of the present invention is to improve the efficiency of radio access from a terminal device to a second radio cell in a radio communication system in which a second radio cell is provided within a radio cell.

[0006] A terminal device according to one aspect of the present invention is used in a wireless communication system including a first base station providing a first cell and a second base station providing a second cell. The terminal device includes: a first communication control unit that uses first information received from the first base station or second information received from the second base station to wait for third information related to communication with the second cell, the third information being transmitted from the second base station; and a second communication control unit that executes an access procedure to transmit a request signal requesting the third information to the second base station and receive a response corresponding to the request signal. When the first communication control unit acquires the third information before the second communication control unit receives the response, the second communication control unit stops the access procedure.

[0007] According to the above-described aspect, in a wireless communication system in which a second wireless cell is provided within a wireless cell, the efficiency of wireless access from a terminal device to the second wireless cell is improved.

[0008] 10 is a diagram illustrating an example of a wireless communication system according to an embodiment of the present invention. FIG. 10 is a diagram illustrating an example of a procedure for requesting control information from a base station. FIG. 10 is a diagram illustrating a method for acquiring OD-SIB1. FIG. 10 is a diagram illustrating an example of a terminal device according to a first embodiment. FIG. 10 is a flowchart illustrating an example of a method for acquiring control information related to communication with an NES cell. FIG. 10 is a flowchart illustrating an example of a procedure for accessing an NES cell. FIG. 10 is a flowchart illustrating an example of a method for determining whether to start the random access procedure shown in FIG. 6. FIG. 10 is a flowchart illustrating an example of processing by an RRC processing unit related to acquisition of OD-SIB1. FIG. 10 is a flowchart illustrating another example of processing by a MAC processing unit related to acquisition of OD-SIB1. FIG. 10 is a flowchart illustrating an example of processing by a MAC processing unit when the random access procedure fails. FIG. 10 is a flowchart illustrating option 2 of the procedure for accessing an NES cell. FIG. 10 is a flowchart illustrating an example of processing by an RRC processing unit related to acquisition of OD-SIB1 in option 2. FIG. 10 is a diagram illustrating an example of an NES base station. FIG. 10 is a diagram illustrating an example of a random access procedure related to a second embodiment. FIG. 10 is a flowchart illustrating an example of processing by a UE in the second embodiment. 10 is a diagram illustrating an example of a random access procedure according to option 2 of the second embodiment. FIG. 11 is a flowchart illustrating an example of a process by a UE in option 2 of the second embodiment.

[0009] 1 shows an example of a wireless communication system according to an embodiment of the present invention. The wireless communication system 1 according to the embodiment of the present invention includes a base station device 10 and an NES base station device 20. The base station device 10 and the NES base station device 20 are, for example, gNBs that support 5G communication or NR (New Radio), although they are not particularly limited thereto. Furthermore, the terminal device 30 is a mobile communication device, and is, for example, a UE (User Equipment), although they are not particularly limited thereto.

[0010] Cell A is provided by a base station device 10. That is, the base station device 10 can accommodate terminal devices 30 located within cell A. The base station device 10 broadcasts a synchronization signal (SSB: Synchronization Signal Block) and a control signal (SIB1: System Information Block 1) to each terminal device 30 within cell A. Then, the terminal device 30 camps on cell A in accordance with the SSB and SIB1. "Camping on a cell" means becoming able to receive predetermined information in the cell, such as SI (System Information), paging that calls the terminal when a call is received, an ETWS (Earthquake and Tsunami Warning System) notification that notifies emergency information, and a CMAS (Commercial Mobile Alert System) notification.

[0011] The NES cell is provided by the NES base station device 20. The NES cell is formed in cell A with support from the base station device 10.

[0012] The SIB transmitted from the base station device 10 (SIB1, Other SIB indicating control information other than SIB1, or a newly defined SIB) includes WUSconfig information. The WUSconfig information also includes information required when the terminal device 30 transmits a wake-up signal (UL-WUS: Up Link Wake Up Signal) to the NES base station device 20. When accessing an NES cell, the terminal device 30 transmits a UL-WUS to the NES base station device 20 in accordance with the WUSconfig information. The UL-WUS corresponds to message 1 that is first transmitted from the UE to the base station in the random access procedure.

[0013] When the NES base station device 20 receives UL-WUS from the terminal device 30, it transmits control information (OD-SIB1: On-Demand SIB1). The OD-SIB1 includes control information for the terminal device 30 to camp on the NES cell. Then, the terminal device 30 camps on the NES cell in accordance with the OD-SIB1. When the terminal device 30 camps on the NES cell, it can receive predetermined information from the NES cell.

[0014] In addition, in 3GPP Release 19, a NES cell is being considered that transmits OD-SIB1 to a UE in IDLE / INACTIVE mode upon request. Also, a procedure using UL-WUS has been agreed upon as a technique for a UE to trigger OD-SIB1. Furthermore, it has been agreed upon that the request based on message 1 in the existing random access procedure will be reused for UL-WUS.

[0015] In the following description, a base station device that provides cell A may be referred to as a "base station." An NES base station device that provides an NES cell may be referred to as an "NES base station." A terminal device that can connect to cell A may be referred to as a "UE."

[0016] 2A shows an example of a procedure in which a UE acquires control information other than SIB1 (e.g., SIB2 to SIB13) in an existing random access procedure. The procedure of requesting SIB2 to SIB13 is sometimes called an SIB request.

[0017] UE 30 transmits message (msg) 1 to base station 10. Message 1 requests desired control information (e.g., any SIB other than SIB 1). Upon receiving message 1, base station 10 transmits message 2 to UE 30. Message 2 is a response in the random access procedure, and is therefore sometimes called a Random Access Response (RAR). Thereafter, base station 10 transmits the control information requested in message 1 to UE 30.

[0018] 2B shows an example of a procedure in which the UE obtains control information from the NES cell. In this case, the UE obtains OD-SIB1 from the NES cell.

[0019] The UE 30 transmits a UL-WUS to the NES base station 20. The UL-WUS corresponds to message 1 in the procedure shown in FIG. 2A and requests OD-SIB1 of the NES cell. The procedure thereafter reuses the procedure between the UE 30 and cell A shown in FIG. 2A. That is, the UE 30 that transmitted the UL-WUS waits for an RAR, just like the UE 30 that transmitted message 1. Upon receiving the UL-WUS, the NES base station 20 transmits an RAR to the UE 30. Thereafter, the NES base station 20 transmits the control information requested by the UL-WUS (i.e., OD-SIB1) to the UE 30. The UE 30 can then camp on the NES cell in accordance with the OD-SIB1.

[0020] As described above, in the procedure shown in Fig. 2B, the UE 30 that transmitted the UL-WUS receives the RAR from the NES base station 20, and then acquires the OD-SIB1. In other words, if the UE 30 cannot receive the RAR from the NES base station 20, there is a risk that the UE 30 will not be able to acquire the OD-SIB1. That is, as shown in Fig. 2C, if the UE 30 cannot receive the RAR from the NES base station 20, the UE 30 determines that the random access procedure to the NES cell has failed. In this case, the UE 30 determines that this NES cell is a "barred cell (a cell that cannot be camped on)."

[0021] When the NES base station 20 receives a UL-WUS from a UE, it transmits an RAR to that UE. Therefore, in a case where multiple UEs transmit UL-WUS simultaneously, the transmission of the RAR from the NES base station 20 to each UE may be delayed. If the UE is unable to receive the RAR within a predetermined time, it retransmits the UL-WUS. As a result, there is a risk that the transmission of the RAR from the NES base station 20 to each UE may be further delayed. If the UE is unable to receive the RAR even after retransmission a predetermined number of times, it determines that the random access procedure to the NES cell has failed.

[0022] 2, the efficiency of radio access from the UE 30 to the NES cell may be low. Specifically, the UE 30 may not be able to acquire the OD-SIB1 from the NES base station 20. Furthermore, the NES base station 20 increases the number of times it transmits the RAR, which increases power consumption.

[0023] <Acquisition of OD-SIB1> Fig. 3 is a diagram illustrating a method for acquiring OD-SIB1. In this example, UE 30a and UE 30b are located in cell A. Note that UE 30a and UE 30b are also located in the NES cell.

[0024] The UE 30a transmits a UL-WUS to the NES base station 20. This UL-WUS corresponds to a SIB1 request requesting the SIB1 (i.e., OD-SIB1) of the NES cell. Upon receiving the UL-WUS, the NES base station 20 transmits an RAR to the UE 30a. The RAR is omitted in FIG. 3. The NES base station 20 then transmits an OD-SIB1 to the UE 30a. This allows the UE 30a to camp on the NES cell using the OD-SIB1.

[0025] Unlike the SIB1 transmitted from the base station 10, the OD-SIB1 is transmitted in response to a request from a UE (UE 30a in FIG. 3). However, the OD-SIB1 is transmitted using a predetermined channel (Physical Downlink Shared Channel: PDSCH). Scheduling information for receiving the OD-SIB1 is transmitted on a predetermined channel (Physical Downlink Control Channel: PDCCH). The PDCCH used to transmit the OD-SIB1 is broadcast to each UE 30 in cell A. For example, the base station 10 broadcasts the SIB1 to each UE 30 in cell A. The SIB1 includes WUSconfig information representing information related to a wake-up signal. The WUSconfig information includes information specifying the PDCCH for the NES base station 20 to transmit the OD-SIB1. Therefore, each UE 30 located in cell A can recognize the PDCCH used to transmit OD-SIB1 by receiving an SIB including WUSconfig from the base station 10. Also, each UE 30 may recognize the PDCCH used to transmit OD-SIB1 from information from cell A other than this WUSconfig.

[0026] Alternatively, each UE 30 located within the NES cell may recognize the PDCCH used to transmit the OD-SIB1 based on a Master Information Block (MIB) broadcast from the NES base station 20. This MIB can be acquired by synchronization information (Synchronization Signal Block (SSB)) for receiving the OD-SIB1.

[0027] In this way, UE 30 located in cell A (or NES cell) can recognize the PDCCH used to transmit OD-SIB1 from information broadcast from base station 10 (or NES base station 20). That is, each UE 30 can acquire OD-SIB1 transmitted from NES base station 20 even when it does not receive an RAR corresponding to UL-WUS from NES base station 20. For example, in the case shown in FIG. 3, NES base station 20 transmits OD-SIB1 in response to a request from UE 30a. At this time, not only UE 30a but also UE 30b can acquire the OD-SIB1.

[0028] On the other hand, in 3GPP, a procedure using UL-WUS when triggering the OD-SIB1 of the NES cell is being considered. Therefore, the terminal device according to the embodiment of the present invention has a function of acquiring the OD-SIB1 of the NES cell even before receiving the RAR in the procedure using UL-WUS when triggering the OD-SIB1 of the NES cell.

[0029] <First embodiment> Fig. 4 shows an example of a terminal device 30 according to the first embodiment. The terminal device (UE) 30 according to the first embodiment includes a communication control unit 31 and a wireless communication unit 34. Note that the UE 30 may further include other functions, devices, or circuits not shown in Fig. 4. Furthermore, the UE 30 is used in the wireless communication system 1 shown in Fig. 1 or 3.

[0030] The communication control unit 31 controls the operation of the UE 30 to realize communication with the wireless cells (cell A and NES cell). That is, the communication control unit 31 generates signals to be transmitted to the wireless cells. The communication control unit 31 also processes signals received from the wireless cells. The communication control unit 31 is realized, for example, by a processor system including a processor and a memory. The communication control unit 31 may also be realized by a digital circuit such as a digital signal processor (DSP) and / or a field programmable gate array (FPGA).

[0031] The communication control unit 31 includes an RRC processing unit 32 and a MAC processing unit 33. The RRC processing unit 32 performs signal processing of the RRC (Radio Resource Control) layer. When the UE 30 is used in the wireless communication system 1 shown in FIG. 1 or 3, the RRC processing unit 32 uses control information (e.g., SIB) received from the base station 10 or control information (e.g., MIB) received from the NES base station 20 to wait for control information (OD-SIB1) related to communication with the NES cell, which is transmitted from the NES base station 20.

[0032] The MAC processing unit 33 processes signals of the MAC (Medium Access Control) layer. When the UE 30 is used in the wireless communication system 1 shown in Fig. 1 or 3, the MAC processing unit 33 executes an access procedure to transmit a request signal (UL-WUS) to the NES base station 20 requesting control information (OD-SIB1) related to communication with the NES cell, and to receive a response (RAR) corresponding to the request signal.

[0033] The RRC processing unit 32 and the MAC processing unit 33 operate in cooperation with each other. The RRC processing unit 32 and the MAC processing unit 33 may be realized by one hardware device (for example, a processor, a DSP, or an FPGA) or by two or more hardware devices.

[0034] The wireless communication unit 34 includes a wireless transmitter and transmits the signal generated by the communication control unit 31 to the wireless cell. The wireless communication unit 34 also includes a wireless receiver and receives the signal from the wireless cell.

[0035] 5 is a flowchart showing an example of a method for UE 30 to acquire control information related to communication with an NES cell. The process of this flowchart is executed, for example, when UE 30 enters the range of cell A or an NES cell in the wireless communication system 1 shown in FIG.

[0036] In S1, the communication control unit 31 receives control information for acquiring OD-SIB1 from the NES cell. This control information includes information indicating a channel (e.g., PDCCH) used to transmit system information of the NES cell (i.e., OD-SIB1). Furthermore, this control information is, for example, an SIB broadcast from the base station 10. In this case, this SIB includes WUSconfig information indicating the PDCCH used to transmit OD-SIB1. Alternatively, the control information for receiving a signal from the NES cell is an MIB broadcast from the NES base station 20.

[0037] In S2, the communication control unit 31 identifies the PDCCH to be used for transmitting the OD-SIB1 based on the control information received in S1 (the SIB broadcast from the base station 10 or the MIB broadcast from the NES base station 20). At this time, the frequency and timing of the PDCCH to be used for transmitting the OD-SIB1 are identified.

[0038] In S3, the communication control unit 31 monitors the PDCCH identified in S2, and waits for OD-SIB1 to be transmitted from the NES base station 20. Note that the communication control unit 31 waits for OD-SIB1 to be transmitted from the NES base station 20, regardless of whether or not the communication control unit 31 itself is transmitting UL-WUS to the NES base station 20. Then, upon acquiring OD-SIB1, the communication control unit 31 stores the acquired OD-SIB1 in a predetermined memory area in S4.

[0039] <Option 1 of the First Embodiment> Fig. 6 is a flowchart showing an example of a procedure in which UE 30 accesses an NES cell. The process of this flowchart is executed when a predetermined initiation condition is satisfied in UE 30. That is, when the predetermined initiation condition is satisfied, UE 30 starts a random access procedure. It is also assumed that the process shown in Fig. 5 (i.e., the process of waiting for OD-SIB1 transmitted from NES base station 20) is continuously performed.

[0040] In S11, the communication control unit 31 selects a Random Access Channel (RACH) preamble. At this time, the communication control unit 31 may determine the channel for transmitting the RACH preamble based on Synchronization Signal Reference Signal Received Power (SS-RSRP).

[0041] In S12, the communication control unit 31 selects the next random access opportunity (RO). The random access opportunity is specified by, for example, an SIB (including WUSconfig) from cell A.

[0042] In S13, the communication control unit 31 transmits a RACH preamble to the NES base station 20 at the random access opportunity selected in S12. The RACH preamble is a SIB1 request requesting the NES's SIB1 (i.e., OD-SIB1) and corresponds to UL-WUS. Thereafter, the communication control unit 31 waits for an RAR corresponding to the RACH preamble.

[0043] If the corresponding RAR is received within a predetermined time period from the time when the RACH preamble (i.e., UL-WUS) was transmitted, the communication control unit 31 continues the procedure shown in Fig. 2B. That is, the communication control unit 31 receives the OD-SIB1 from the NES base station 20 and camps on the NES cell using the received OD-SIB1.

[0044] If the corresponding RAR cannot be received within the predetermined time, the communication control unit 31 determines in S14 whether or not it has acquired the OD-SIB1 transmitted from the NES base station 20. The communication control unit 31 continuously executes the procedure of the flowchart shown in Fig. 5. Therefore, when the NES base station 20 transmits the OD-SIB1, the communication control unit 31 can acquire the OD-SIB1.

[0045] If OD-SIB1 has not been acquired, the communication control unit 31 increments a counter in S15 to S16. This counter counts the number of times random access to the NES base station 20 has been performed. If the counter value does not exceed a predetermined maximum value max, the processing of the communication control unit 31 returns to S11. The maximum value max is set by the base station 10 or the NES base station 20.

[0046] The communication control unit 31 repeatedly executes the processes of S11 to S16. Then, if the communication control unit 31 acquires OD-SIB1 from the NES base station 20 before the number of times the RACH preamble is transmitted exceeds the maximum value max, the communication control unit 31 stops the random access procedure to the NES cell in S17. That is, if the communication control unit 31 acquires OD-SIB1 before receiving the corresponding RAR, the communication control unit 31 assumes that the RAR from the NES base station 20 has been received, and stops the random access procedure. This realizes the procedure shown in FIG. 2B regardless of whether the UE 30 has received the RAR.

[0047] After that, the communication control unit 31 camps on the NES cell using the acquired OD-SIB 1. If the OD-SIB 1 cannot be acquired before the number of RACH preamble transmissions exceeds the maximum value max, the communication control unit 31 determines that the random access procedure to the NES base station 20 has failed.

[0048] In this way, the UE 30 can acquire the OD-SIB1 even before receiving the corresponding RAR after transmitting the RACH preamble (i.e., UL-WUS) to the NES base station 20. Then, when the UE 30 acquires the OD-SIB1 before receiving the corresponding RAR, the UE 30 stops the random access procedure to the NES cell that is considered to have received the RAR. Therefore, even if the RAR corresponding to the RACH preamble is delayed in the random access procedure to the NES cell, the UE 30 can efficiently camp on the NES cell.

[0049] An example of a method for acquiring OD-SIB1 during a SIB1 request procedure (i.e., a procedure for transmitting a UL-WUS and receiving a corresponding RAR) will be described. For example, the RRC processing unit 32 of the UE 30 attempts to receive OD-SIB1 regardless of whether the MAC processing unit 33 is performing the SIB1 request procedure (i.e., a procedure for transmitting a UL-WUS and receiving a corresponding RAR). That is, the process of S14 in FIG. 6 is executed, for example, by the RRC processing unit 32. Then, upon receiving OD-SIB1, the RRC processing unit 32 notifies the MAC processing unit 33 of this fact. Note that the RRC processing unit 32 attempts to receive OD-SIB1 until it is notified by the MAC processing unit 33 that the random access procedure has failed.

[0050] When the SIB1 request procedure is triggered, if the MAC processing unit 33 is notified by the RRC processing unit 32 that OD-SIB1 has been received, the MAC processing unit 33 does not start the SIB1 request procedure. Furthermore, after the start of the SIB1 request procedure, if the RRC processing unit 32 notifies the MAC processing unit 33 that OD-SIB1 has been received, the MAC processing unit 33 considers the SIB1 request procedure to be successful and stops or terminates the SIB1 request procedure. Note that, if the number of times that the RAR cannot be received exceeds a predetermined maximum value before receiving a notification indicating that OD-SIB1 has been received from the RRC processing unit 32, the MAC processing unit 33 notifies the RRC processing unit 32 that the random access procedure has failed. In this way, the processes of S11 to S13 and S15 to S17 in FIG. 6 are mainly executed by the MAC processing unit 33. Note that the "random access procedure has failed" can be expressed in other ways, such as "SIB1 request has failed" or "acquisition of a random access response has failed."

[0051] Fig. 7 is a flowchart showing an example of a method for determining whether to start the random access procedure shown in Fig. 6. In steps S21 to S23, the MAC processing unit 33 determines whether all or some of the following three conditions are met: (1) An instruction to start the random access procedure for the SIB1 request has been issued (i.e., the random access procedure for the SIB1 request has been triggered); (2) Resources to be allocated to the random access procedure for the SIB1 request have been provided by the RRC processing unit 32; or (3) A notification indicating that the OD-SIB1 has been acquired has been received from the RRC processing unit 32.

[0052] Then, when conditions including some or all of the following are met: the start of a random access procedure for a SIB1 request has been instructed, resources to be allocated to the random access procedure for a SIB1 request have been provided by the RRC processing unit 32, and a notification indicating that OD-SIB1 has been acquired has not been received from the RRC processing unit 32, the MAC processing unit 33 starts the random access procedure shown in Figure 6.

[0053] 8 is a flowchart showing an example of processing by the RRC processing unit 32 related to acquisition of the OD-SIB1. This processing is executed after the UE 30 identifies the PDCCH used to transmit the OD-SIB1. Furthermore, the RRC processing unit 32 can execute the processing in FIG. 8 regardless of whether the MAC processing unit 33 has requested the NES base station 20 for the OD-SIB1.

[0054] In S31, the RRC processing unit 32 causes the MAC processing unit 33 to monitor the identified PDCCH and receives the MAC PDU that has been decoded there. Then, the RRC processing unit 32 waits for the decoded OD-SIB1 transmitted from the NES base station 20. Then, upon acquiring the OD-SIB1, the RRC processing unit 32 notifies the lower layer (i.e., the MAC layer) in S32 that the OD-SIB1 has been acquired. That is, the RRC processing unit 32 notifies the MAC processing unit 33 that the OD-SIB1 has been acquired. At this time, the RRC processing unit 32 transmits an indication (SIB1 acquisition indication) indicating that the OD-SIB1 has been acquired to the MAC processing unit 33. Alternatively, the MAC processing unit 33 may determine that the OD-SIB1 has been acquired because it was successfully decoded.

[0055] If OD-SIB1 has not been acquired, the RRC processing unit 32 determines in S33 whether or not an indication indicating that the RAR cannot be acquired (SIB1 request failure indication) has been received from the MAC processing unit 33. If an SIB1 request failure indication has not been received, the processing of the RRC processing unit 32 returns to S31. That is, the RRC processing unit 32 continues the operation of waiting for OD-SIB1 transmitted from the NES base station 20.

[0056] When the SIB1 request failure indication is received, the RRC processing unit 32 determines in S34 that the NES cell is a "barred cell (a cell on which the UE 30 cannot camp on)." In this case, the UE 30 may attempt to access another NES cell.

[0057] 9 is a flowchart showing an example of processing by the MAC processing unit 33 related to acquisition of the OD-SIB1. This processing corresponds to S14 shown in FIG. 6. This processing is also realized in the procedure for transmitting the RACH preamble.

[0058] In S41, the MAC processing unit 33 determines whether a random access procedure for acquiring OD-SIB1 has been initiated. That is, it is determined whether a random access procedure for acquiring OD-SIB1 has been triggered. For example, the MAC processing unit 33 determines whether an instruction to transmit a RACH preamble has been issued to the physical layer of the UE 30. In addition, in S42, the MAC processing unit 33 determines whether an indication indicating that OD-SIB1 has been received (i.e., the SIB1 acquisition indication transmitted in S32 of FIG. 8) has been received from the RRC processing unit 32.

[0059] When the random access procedure for acquiring OD-SIB1 has been initiated and the SIB1 acquisition indication has been received, the MAC processing unit 33 determines in S43 that the random access procedure has been successfully completed. In this case, the processing of the MAC processing unit 33 proceeds to S17 shown in FIG. 6. That is, the MAC processing unit 33 stops the random access procedure, and the UE 30 camps on the NES cell. On the other hand, when the random access procedure for acquiring OD-SIB1 has not been initiated or the SIB1 acquisition indication has not been received, the processing of the MAC processing unit 33 proceeds to S15 shown in FIG. 6.

[0060] 10 is a flowchart showing another example of the process of the MAC processing unit 33 for acquiring the OD-SIB1. This process corresponds to S14 shown in FIG. 6. This process is realized in the procedure for receiving the RAR corresponding to the RACH preamble.

[0061] In S51, the MAC processing unit 33 determines whether or not a RACH preamble for acquiring OD-SIB1 has already been transmitted to the NES base station 20. In addition, in S52, the MAC processing unit 33 determines whether or not an indication indicating that OD-SIB1 has been received (i.e., the SIB1 acquisition indication transmitted in S32 in FIG. 8) has been received from the RRC processing unit 32.

[0062] If the RACH preamble has been transmitted to the NES base station 20 and the SIB1 acquisition indication has been received, the MAC processing unit 33 determines in S53 that the random access procedure has been successfully completed. In this case, the processing of the MAC processing unit 33 proceeds to S17 shown in Fig. 6. That is, the MAC processing unit 33 stops the random access procedure, and the UE 30 camps on the NES cell. On the other hand, if the RACH preamble has not been transmitted to the NES base station 20 or the SIB1 acquisition indication has not been received, the processing of the MAC processing unit 33 proceeds to S15 shown in Fig. 6.

[0063] Fig. 11 is a flowchart showing an example of the processing of the MAC processing unit 33 when the random access procedure has failed. This processing corresponds to S15 to S16 shown in Fig. 6, and is executed when it is determined that the random access has not been successful in the flowchart shown in Fig. 9 or 10.

[0064] In S61, the MAC processing unit 33 determines that reception of the RAR corresponding to the RACH preamble has failed. In S62, the MAC processing unit 33 increments the preamble transmission counter by 1. The preamble transmission counter counts the number of times that the UE 30 has transmitted the RACH preamble to the NES base station 20.

[0065] In S63, the MAC processing unit 33 compares the count value of the preamble transmission counter with a predetermined maximum value Max. The maximum value Max is set by the base station 10 or the NES base station 20. If the count value is equal to or less than the maximum value Max, the processing of the MAC processing unit 33 returns to S11 in Fig. 6. In other words, if the RRC processing unit 32 has not acquired OD-SIB1, the processing of S11 to S15 shown in Fig. 6 is repeatedly executed until the count value exceeds the maximum value Max.

[0066] When the count value exceeds the maximum value Max, the MAC processing unit 33 determines in S64 that the SIB1 request procedure has failed. Then, in S65, the MAC processing unit 33 notifies the upper layer (i.e., the RRC layer) of a SIB1 request failure indication indicating that the SIB1 request procedure has failed. That is, the SIB1 request failure indication is transmitted from the MAC processing unit 33 to the RRC processing unit 32. The SIB1 request failure indication is referenced in S42 of FIG. 9 or S52 of FIG. 10.

[0067] <Option 2 of the First Embodiment> Fig. 12 is a flowchart showing another example of the procedure for accessing the NES cell (i.e., option 2). The process of this flowchart is executed when the start condition shown in Fig. 7 is satisfied in the UE 30, similar to option 1 shown in Fig. 6. It is also assumed that the process shown in Fig. 5 (i.e., the process of waiting for OD-SIB1 transmitted from the NES base station 20) is being performed continuously.

[0068] In Option 1 shown in Fig. 6, UE 30 determines whether or not OD-SIB1 has been acquired each time it transmits a RACH preamble. In contrast, in Option 2, UE 30 determines whether or not OD-SIB1 has been acquired after transmitting a RACH preamble a predetermined number of times. The predetermined number of times may be the same as the maximum value Max shown in Fig. 6.

[0069] Specifically, UE 30 repeatedly transmits a RACH preamble to NES base station 20 to acquire OD-SIB1 (S11 to S13, S15, S16). Then, when UE 30 does not receive an RAR from NES base station 20 and the number of times the RACH preamble is transmitted exceeds the maximum value Max, UE 30 attempts to acquire OD-SIB1 in S71 to S72. As a result, if OD-SIB1 is successfully acquired, there is no need to receive an RAR from NES base station 20, so UE 30 stops the random access procedure in S17 and then camps on the NES cell. On the other hand, if OD-SIB1 cannot be acquired, it is determined that the random access procedure has failed.

[0070] In option 2, the RRC processing unit 32 and the MAC processing unit 33 also operate in cooperation with each other. Here, the operation of the MAC processing unit 33 is generally the same in option 1 and option 2. That is, in option 2, the MAC processing unit 33 repeatedly transmits a RACH preamble to the NES base station 20. Then, when the number of times the RACH preamble is transmitted exceeds the maximum value Max without receiving an RAR, the MAC processing unit 33 notifies the RRC processing unit 32 of a SIB1 request failure indication. Alternatively, before notifying the RRC processing unit 32 of the SIB1 request failure indication, the specified PDCCH is monitored, and if the MAC PDU can be decoded there, the UE 30 recognizes that the OD-SIB1 has been acquired, and the UE 30 stops the random access procedure and then camps on the NES cell.

[0071] 13 is a flowchart showing an example of processing by the RRC processing unit 32 related to acquisition of OD-SIB1 in Option 2. This processing is executed after the UE 30 identifies the PDCCH used to transmit OD-SIB1.

[0072] In S81, the RRC processing unit 32 waits for an indication indicating that the OD-SIB1 request has failed (i.e., an SIB1 request failure indication). As in Option 1, the SIB1 request failure indication is generated by the MAC processing unit 33 when the number of RACH preamble transmissions exceeds the maximum value Max without receiving an RAR, as shown in the flowchart of FIG.

[0073] Upon receiving the SIB1 request failure indication, the RRC processing unit 32 causes the MAC processing unit 33 to monitor the identified PDCCH and receives the MAC PDU that has been decoded therein in steps S82 to S83. The RRC processing unit 32 then attempts to acquire the decoded OD-SIB1. If the OD-SIB1 has been acquired, the UE 30 stops the random access procedure and then camps on the NES cell. On the other hand, if the OD-SIB1 has not been acquired, the RRC processing unit 32 determines that the accessed NES cell is a "barred cell (a cell that cannot be camped on)."

[0074] As described above, according to the first embodiment, when UE 30 wants to camp on an NES cell, it requests OD-SIB1 from NES base station 20 using the preamble of the random access procedure. After this, UE 30 can acquire OD-SIB1 regardless of whether it receives a response to the preamble. Therefore, even if UE 30 cannot receive a response to the preamble or if the response to the preamble is delayed, UE 30 can acquire OD-SIB1 and camp on the NES cell. In other words, in a wireless communication system 1 in which an NES cell is provided within cell A, the efficiency of wireless access from UE 30 to the NES cell is improved.

[0075] In the random access procedure for requesting the SIB1 of the NES cell, when the UE 30 receives a response to the preamble, the UE 30 camps on the NES cell in the normal procedure shown in Fig. 2B. That is, after receiving the response to the preamble, the UE 30 acquires the OD-SIB1 transmitted from the NES base station 20 and camps on the NES cell.

[0076] Second Embodiment When the NES base station 20 receives a UL-WUS from a UE 30, it transmits a corresponding response (i.e., an RAR) to the UE 30. Furthermore, in a case where UL-WUSs are received from multiple UEs 30, the NES base station 20 transmits a corresponding RAR for each UL-WUS. For example, in the wireless communication system 1 shown in FIG. 3 , when the NES base station 20 receives a UL-WUS from UE 30a, it transmits an RAR to UE 30a that includes information identifying UE 30a, and when it receives a UL-WUS from UE 30b, it transmits an RAR to UE 30b that includes information identifying UE 30b. Therefore, in a case where UL-WUSs are received from multiple UEs 30, the power consumption of the NES base station 20 increases. Therefore, in the second embodiment, the power consumption of the NES base station 20 in the SIB1 request procedure for requesting the SIB1 of the NES cell is reduced.

[0077] Fig. 14 shows an example of an NES base station 20. The NES base station 20 includes a communication control unit 21 and a wireless communication unit 22. The NES base station 20 may further include other functions, devices, or circuits not shown in Fig. 14. The NES base station 20 is used in the wireless communication system 1 shown in Fig. 1 or 3.

[0078] The communication control unit 21 controls the operation of the NES base station 20 to realize communication with the UE 30. That is, the communication control unit 21 generates signals to be transmitted to the UE 30 and processes signals received from the UE 30. The communication control unit 21 also processes signals of the RRC layer and the MAC layer. The communication control unit 21 is realized, for example, by a processor system including a processor and a memory. The communication control unit 21 may also be realized by a digital circuit such as a digital signal processor and / or an FPGA.

[0079] The wireless communication unit 22 includes a wireless transmitter and transmits a signal generated by the communication control unit 21 to the UE 30. The wireless communication unit 22 also includes a wireless receiver and receives a signal from the UE 30.

[0080] The configuration and operation of the UE 30 are substantially the same in the first embodiment and the second embodiment. That is, in the second embodiment, the UE 30 also includes a communication control unit 31 and a wireless communication unit 34, and the communication control unit 31 includes an RRC processing unit 32 and a MAC processing unit 33, as shown in FIG.

[0081] 15 shows an example of a random access procedure according to the second embodiment. In this example, UEs 30a and 30b are located within an NES cell provided by an NES base station 20.

[0082] In the case shown in FIG. 15A , the UE 30a transmits a wake-up signal UL-WUS for the random access procedure to the NES base station 20. This UL-WUS includes a Random Access Radio Network Temporary Identifier (RA-RNTI) that is set so that the UE 30a can be distinguished from other UEs during RA. The NES base station 20 then transmits a response signal corresponding to the received UL-WUS to the UE 30a. The response signal includes information related to the RA-RNTI received from the UE 30. The response signal is Downlink Control Information (DCI) and / or an RAR. For example, the DCI includes a code sequence obtained by scrambling predetermined information with the RA-RNTI received from the UE 30. In this way, the response signal transmitted from the NES base station 20 includes information related to the identification information of the UL-WUS sender.

[0083] UE 30a decodes the PDCCH using its own RA-RNTI. If this decoding is successful, UE 30a determines that the reception of the RAR in the random access procedure has been successful. At this time, the response signal transmitted from the NES base station 20 also reaches UE 30b. However, the value of the RA-RNTI of UE 30b is different from the value of the RA-RNTI of UE 30a. Therefore, UE 30b determines that the received signal is not a response signal addressed to itself.

[0084] In the case shown in Fig. 15B, UE 30a transmits an SIB1 request to the NES base station 20 to request SIB1 of the NES cell. The SIB1 request corresponds to message 1 in the random access procedure. Here, in option 1 of the second embodiment, a new RA-RNTI having a predetermined value is used as the RA-RNTI to be assigned to the SIB1 request. The new RA-RNTI is assumed to be shared by all UEs 30 in the NES cell. Furthermore, the value of the new RA-RNTI is broadcast from the NES base station 20 to each UE 30, for example. In this case, the value of the new RA-RNTI may be broadcast to each UE 30 using SSB.

[0085] The NES base station 20 that has received the SIB1 request including the new RA-RNTI transmits a response signal corresponding to the received SIB1 request to the UE 30a. This response signal includes information related to the received SIB1 request. For example, the response signal includes a code sequence obtained by scrambling predetermined information with the received new RA-RNTI.

[0086] Since UE 30a has previously transmitted an SIB1 request to NES base station 20, it decodes the PDCCH using the new RA-RNTI. In this case, since the decoding is successful, UE 30a determines that reception of the RAR has been successful. In other words, it considers the random access procedure to be successful. After this, UE 30a obtains OD-SIB1 from NES base station 20 and camps on the NES cell.

[0087] The response signal transmitted from the NES base station 20 also reaches the UE 30b. Here, it is assumed that the UE 30b also requests the SIB1 (i.e., OD-SIB1) of the NES cell. In this case, the UE 30b monitors the response signal transmitted from the NES base station 20 and decodes the PDCCH. At this time, the UE 30b decodes the PDCCH using the new RA-RNTI, not the RA-RNTI addressed to itself using the conventional method. In this case, since the decoding is successful, the UE 30b considers that the reception of the RAR has been successful. Thereafter, the UE 30b acquires the OD-SIB1 from the NES base station 20 and camps on the NES cell.

[0088] In this way, even if UE 30b has not received an RAR addressed to itself using the conventional method from NES base station 20, UE 30b can acquire OD-SIB1 by assuming that reception of the RAR in the random access procedure has been successful. In this case, NES base station 20 does not need to transmit an RAR to UE 30b. Therefore, power consumption of NES base station 20 is reduced.

[0089] 16 is a flowchart showing an example of a process of the UE 30 in the second embodiment. This process is executed when a random access procedure is triggered in the UE 30. This process is mainly executed by the MAC processing unit 33.

[0090] In S91, UE 30 determines whether the triggered random access procedure is a random access procedure for acquiring SIB1 (i.e., OD-SIB1) of the NES cell. If a random access procedure other than for acquiring OD-SIB1 is triggered, UE 30 performs a normal random access procedure in S98. In this case, the RA-RNTI of UE 30 is assigned to message 1.

[0091] When the random access procedure for acquiring the OD-SIB1 is triggered, in S92, the UE 30 monitors a response signal transmitted from the NES base station 20. If the response signal cannot be received, in S93, the UE 30 transmits a SIB1 request including a new RA-RNTI to the NES base station 20. Thereafter, the UE 30 returns to S92 and waits for a response signal.

[0092] When the UE 30 receives a response signal transmitted from the NES base station 20, the UE 30 decodes the received response signal using the new RA-RNTI in steps S94 and S95. If the decoding is successful, the UE 30 determines in step S96 that the reception of the RAR in the random access procedure has been successful. At this time, the UE 30 determines that the reception of the RAR has been successful even if the received response signal does not include identification information representing the UE 30 itself (for example, RAPID: RA Preamble ID). After this, the processing of the UE 30 proceeds to a procedure for acquiring the OD-SIB1 from the NES base station 20.

[0093] If the response signal cannot be decoded, the UE 30 performs error processing in S97. In the error processing, the UE 30 may retransmit the SIB1 request to the NES base station 20. Alternatively, the UE 30 may access another NES cell.

[0094] 15B transmits an SIB1 request to the NES base station 20 in S93, and then receives a response signal in S92. In contrast, if a random access procedure for acquiring OD-SIB1 has been triggered, the UE 30b shown in FIG. 15B can also receive and decode the response signal received by the UE 30a.

[0095] 17 shows an example of a random access procedure according to option 2 of the second embodiment. In this example, UEs 30a and 30b are located within an NES cell provided by an NES base station 20.

[0096] The UE 30a transmits an SIB1 request to the NES base station 20 in the random access procedure. Upon receiving the SIB1 request, the NES base station 20 transmits a corresponding RAR to the UE 30a. At this time, the RAR includes predetermined information. For example, the RAR includes a common MAC PDU (Protocol Data Unit). The contents of the common MAC PDU are predetermined and, for example, are broadcast from the NES base station 20 to each UE 30 in the NES cell. In this way, upon receiving an SIB1 request in the random access procedure, the NES base station 20 transmits the common MAC PDU to the sender of the SIB1 request.

[0097] After transmitting the SIB1 request, the UE 30a monitors the RAR. If the received RAR includes a common MAC PDU, the UE 30a determines that the RAR has been successfully received. In this case, the UE 30a obtains the OD-SIB1 from the NES base station 20 and camps on the NES cell.

[0098] The RAR transmitted from the NES base station 20 also reaches the UE 30b. Here, when a random access procedure for acquiring the OD-SIB1 is triggered, the UE 30b monitors the RAR transmitted from the NES base station 20. Then, when the UE 30b detects a common MAC PDU from the received RAR, it considers that the reception of the RAR has been successful.

[0099] Note that the information included in the RAR is not limited to a common MAC PDU, and for example, a common MAC-CE (Control Element) may be included in the RAR.

[0100] 18 is a flowchart showing an example of processing by UE 30 in option 2 of the second embodiment. The processing by UE 30 in option 1 and option 2 in the second embodiment is generally the same. However, in option 2, UE 30 monitors the RAR transmitted from the NES base station 20 in S101. Furthermore, in S102, UE 30 transmits an SIB1 request including its own RA-RNTI to the NES base station 20. In response, the NES base station 20 transmits an RAR including a common MAC PDU (or common MAC-CE) to UE 30.

[0101] In addition, when UE 30 receives an RAR from NES base station 20, UE 30 determines in S103 whether the RAR includes a common MAC PDU. At this time, UE 30 determines whether the received RAR includes a common MAC PDU, regardless of whether the RAR is addressed to UE 30. If the RAR includes a common MAC PDU, UE 30 determines in S96 that the RAR has been successfully received.

[0102] 17 transmits a SIB1 request to the NES base station 20 in S102, and then receives an RAR in S101. In contrast, if a random access procedure for acquiring OD-SIB1 has been triggered, UE 30b in FIG. 17 receives the RAR addressed to UE 30a and executes the process of S103.

[0103] In this way, even if UE 30b has not received an RAR addressed to itself from NES base station 20, it can acquire OD-SIB1 by assuming that reception of the RAR of the random access procedure has been successful. In this case, NES base station 20 does not need to transmit an RAR to UE 30b. Therefore, as with option 1, option 2 also reduces the power consumption of NES base station 20.

[0104] In the second embodiment, the search space representing the PDCCH resource associated with the RAR may be shared. Furthermore, in a case where both the above-described Option 1 and Option 2 are used, for example, Option 1 is prioritized. That is, when a random access procedure for acquiring OD-SIB1 is triggered, UE 30 first determines whether reception of the RAR was successful by decoding the PDCCH with the new RA-RNTI. Furthermore, if this decoding fails, a common MAC PDU (or a common MAC-CE) is detected from the received RAR. Furthermore, if both Option 1 and Option 2 fail, a normal random access procedure is executed.

[0105] Although this embodiment has been described using the case of NES, this embodiment can be applied to other technologies and methods. Furthermore, some of the messages in the sequence and the steps in the flowchart described above may not be performed in the correct order, or the order may be reversed. Furthermore, some of the messages in the sequence and the steps in the flowchart may not be performed.

[0106] "A may be replaced with B" and "A may be replaced with B" not only mean replacing A with B, but also B with A. Furthermore, if the conditions "A" and "B" are contradictory conditions, the condition "B" may be expressed as an "other" condition of the condition "A."

[0107] In each embodiment, an example of a device is described, but the method of the present disclosure is not limited to cellular phones, smartphones, tablet terminals, base station devices, etc., and can be applied to other electronic devices, for example, electronic devices mounted on automobiles, trains, airplanes, artificial satellites, etc., electronic devices mounted on drones, etc., robots, AV equipment, home appliances, office equipment, vending machines, other household equipment, industrial equipment, and other devices.

[0108] Although each embodiment has been described using NR, which is a radio access technology for fifth-generation communication, the application of the method of the present disclosure is not limited to this. For example, the method of the present disclosure may be applied to radio access technologies and networks for different generations of communication, such as sixth generation and seventh generation.

[0109] The present invention is not limited to the above-described embodiment, and various modifications can be made.

[0110] Although each embodiment has been described in detail with reference to the drawings, the specific configuration is not limited to the disclosed drawings and the described embodiments.

[0111] REFERENCE SIGNS LIST 1 Wireless communication system 10 Base station device 20 NES base station device 21 Communication control unit 22 Wireless communication unit 30, 30a, 30b Terminal device (UE) 31 Communication control unit 32 RRC processing unit 33 MAC processing unit 34 Wireless communication unit

Claims

1. A terminal device used in a wireless communication system including a first base station that provides a first cell and a second base station that provides a second cell, comprising: a first communication control unit that uses first information received from the first base station or second information received from the second base station to wait for third information related to communication with the second cell, which is transmitted from the second base station; and a second communication control unit that executes an access procedure that transmits a request signal requesting the third information to the second base station and receives a response corresponding to the request signal, wherein when the first communication control unit acquires the third information before the second communication control unit receives the response, the second communication control unit stops the access procedure.

2. The terminal device according to claim 1, characterized in that, when the first communication control unit has already acquired the third information at the start of the access procedure, the second communication control unit does not execute the access procedure.

3. The terminal device described in claim 1, characterized in that the second communication control unit determines whether the first communication control unit has acquired the third information each time the access procedure is executed, stops the access procedure when the first communication control unit acquires the third information before the number of times the access procedure is executed exceeds a predetermined maximum value, and outputs a failure display indicating that the access procedure has failed when the number of times the access procedure is executed exceeds the maximum value.

4. The terminal device described in claim 1, characterized in that the second communication control unit repeatedly executes the access procedure, and when the number of times the second communication control unit executes the access procedure exceeds a predetermined maximum value, the first communication control unit attempts to acquire the third information.

5. A wireless communication system including a first base station providing a first cell, a second base station providing a second cell, and a plurality of terminal devices, wherein a first terminal device among the plurality of terminal devices comprises: a first communication control unit that uses first information received from the first base station or second information received from the second base station to wait for third information related to communication with the second cell, which is transmitted from the second base station; and a second communication control unit that executes an access procedure that transmits a request signal requesting the third information to the second base station and receives a response corresponding to the request signal, wherein, upon receiving the request signal from the first terminal device, the second base station transmits a response corresponding to the request signal to the first terminal device and also transmits the third information to the first terminal device, and wherein each of the plurality of terminal devices considers that the access procedure requesting the third information has been triggered and that the access procedure has been successful when the third information has been acquired.

6. A terminal device used in a wireless communication system including a first base station providing a first cell and a second base station providing a second cell, comprising: a first communication control unit that uses first information received from the first base station or second information received from the second base station to wait for third information related to communication with the second cell, transmitted from the second base station; and a second communication control unit that executes an access procedure that transmits a request signal requesting the third information to the second base station and receives a response corresponding to the request signal, wherein the second base station is configured to, upon receiving the request signal, transmit a code generated using predetermined common information via a specified channel, and the second communication control unit is configured to consider the access procedure to be successful when it can decode the specified channel using the common information.

7. A wireless communication system including a first base station providing a first cell, a second base station providing a second cell, and a plurality of terminal devices, wherein a first terminal device among the plurality of terminal devices comprises: a first communication control unit that uses first information received from the first base station or second information received from the second base station to wait for third information related to communication with the second cell, which is transmitted from the second base station; and a second communication control unit that executes an access procedure that transmits a request signal requesting the third information to the second base station and receives a response corresponding to the request signal; when the second base station receives the request signal from the first terminal device, it transmits a code generated using predetermined common information via a specified channel; and when each of the plurality of terminal devices determines that the access procedure requesting the third information has been triggered and that the specified channel can be decoded using the common information, the wireless communication system is characterized in that 8. A base station device that provides a second cell in a wireless communication system including a first cell and a second cell, wherein a first terminal device among a plurality of terminal devices used in the wireless communication system comprises: a first communication control unit that waits for third information related to communication with the second cell, transmitted from the base station device, using first information received from the first cell or second information received from the base station device; and a second communication control unit that executes an access procedure to transmit a request signal requesting the third information to the base station device and receive a response corresponding to the request signal; and wherein the base station device comprises a communication control unit that, when receiving the request signal from the first terminal device, transmits the response including predetermined common information to the first terminal device.

9. A wireless communication system including a first base station providing a first cell, a second base station providing a second cell, and a plurality of terminal devices, wherein a first terminal device among the plurality of terminal devices comprises: a first communication control unit that uses first information received from the first base station or second information received from the second base station to wait for third information related to communication with the second cell, which is transmitted from the second base station; and a second communication control unit that executes an access procedure that transmits a request signal requesting the third information to the second base station and receives a response corresponding to the request signal; when the second base station receives the request signal from the first terminal device, it transmits the response including predetermined common information to the first terminal device; and when each of the plurality of terminal devices determines that the access procedure requesting the third information has been triggered and that the response including the common information has been received, it determines that the access procedure has been successful.

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