Terminal device, base station device, and wireless communication system

Abstract

This terminal device has a reception unit that receives first information transmitted from a first base station device, and second information transmitted from a second base station device in accordance with an uplink signal of the terminal device, said uplink signal being based on the first information. The terminal device also has a processing unit that, if the first information is stored, determines whether the second information corresponding to the first information is valid, on the basis of the result of a determination regarding whether the first information is valid.

Description

Terminal device, base station device, and wireless communication system

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

[0002] In today's networks, traffic from mobile devices (such as smartphones and feature phones) accounts for the majority of network resources, and the traffic used by mobile devices is expected to continue to expand.

[0003] In addition to traffic used by mobile terminals, for example, IoT (Internet of things) services (for example, monitoring systems for transportation systems, smart meters, devices, etc.) are being deployed. Therefore, networks are required to support services with diverse requirements. In order to support such diverse services, for example, in the communication standard for fifth-generation mobile communications (5G or NR (New Radio)) (for example, Non-Patent Document 1), eMBB (Enhanced Mobile Broadband), Massive MTC (Machine Type Communications), and URLLC (Ultra-Reliable and Low Latency Communications) The standard is being formulated assuming support for many use cases.

[0004] In addition, in the 3rd Generation Partnership Project (3GPP), an international standardization project, extension technologies for the above communication standards are currently being continuously studied and standardized.

[0005] For example, 3GPP is studying NES (Network Energy Savings), a network power reduction technology (Non-Patent Documents 2 and 3). Hereinafter, a cell (base station device) that corresponds to the NES function, i.e., a cell that supports the NES function, will also be referred to as an NES cell.

[0006] 3GPP TS 38.300 V18.1.0R2-2405136, InterDigitalR2-2404894, vivo

[0007] Generally, a base station device broadcasts system information within the cell as information commonly used by terminal devices within the cell. System information is also referred to as broadcast information. 3GPP is studying a method for reducing power consumption of a base station device by introducing an on-demand SIB1, which is appropriately transmitted (on-demand transmitted) from an NES cell in response to a request from a terminal device, instead of SIB1 (System Information Block Type 1), which is a type of broadcast information transmitted periodically. However, it is necessary to define a method for determining the validity of the on-demand SIB1 in a terminal device when information required to acquire the on-demand SIB1 is transmitted from a cell other than the NES cell, and a specific control method after the base station device and terminal device acquire the on-demand SIB1. However, neither Non-Patent Document 2 nor Non-Patent Document 3 mentions any solutions to these problems.

[0008] Therefore, one disclosure provides a terminal device, a base station device, and a wireless communication system that enable appropriate control of the On-demand SIB1 of the terminal device when information required to acquire the On-demand SIB1 is transmitted from a cell other than the NES cell.

[0009] The terminal device has a receiving unit that receives first information transmitted from a first base station device and second information transmitted from a second base station device in response to an uplink signal of the terminal device based on the first information. The terminal device also has a processing unit that, when the terminal device stores the first information, determines whether second information corresponding to the first information is valid based on a result of determining whether the first information is valid.

[0010] One disclosure provides an appropriate method for controlling On-demand SIB1 in a wireless communication system that applies On-demand SIB1 as a network power reduction technology, thereby making it possible to improve the power saving effect of a terminal device and a base station device.

[0011] FIG. 1 is a diagram showing an example of the configuration of a wireless communication system 10. FIG. 2 is a diagram showing an example of the configuration of a terminal device 100. FIG. 3 is a diagram showing an example of the configuration of a base station device 200. FIG. 4 is a diagram showing an example of the sequence of a determination control process in the first embodiment. FIG. 5 is a diagram showing an example of a flowchart of the determination control process in the first embodiment. FIG. 6 is a diagram showing an example of the sequence of a determination control process in the second embodiment. FIG. 7 is a diagram showing an example of the sequence of a determination control process in the third embodiment. FIG. 8 is a diagram showing an example of the sequence of a determination control process in the fourth embodiment.

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The problems and embodiments in this specification are merely examples and do not limit the scope of the rights of the present application. In particular, even if the expressions used are different, the technology of the present application can be applied as long as they are technically equivalent, and do not limit the scope of the rights. Furthermore, each embodiment can be appropriately combined within the scope of the processing content.

[0013] Publicly known technologies may be used as appropriate in the wireless communication system according to the embodiment of the present invention. Applicable publicly known technologies may be, for example, 5G (NR), Beyond 5G, 5G-Advanced, or other wireless communication methods. The wireless communication system according to the embodiment of the present invention targets NR, but is not limited thereto. For example, the embodiment of the present invention can also be applied to LTE (Long Term Evolution) and LTE-Advanced. It can also be applied to a wireless communication system that uses NR as part of the wireless communication system.

[0014] Furthermore, the embodiments of the present invention are applicable to any wireless communication system including at least a terminal device and a base station device, and are also applicable to future wireless communication systems such as 6G. In the following description, LTE and LTE-Advanced are also referred to as E-UTRA (Evolved Universal Terrestrial Radio Access), but the meaning is the same.

[0015] First Embodiment (Regarding Wireless Communication System 10) FIG. 1 is a diagram showing an example of the configuration of a wireless communication system 10. As shown in FIG.

[0016] 1, the wireless communication system 10 includes, for example, a terminal device 100, a base station device 200-1, and a base station device 200-2. The wireless communication system 10 is, for example, a wireless communication system that supports NES, in other words, a wireless communication system that supports the functions of NES. Hereinafter, the base station device 200-1 and the base station device 200-2 will be collectively referred to simply as the base station device 200. There may also be multiple terminal devices 100.

[0017] The terminal device 100 may be a wireless terminal such as a mobile phone, a smartphone, a PDA (Personal Digital Assistant), a tablet, a wearable device, a personal computer, a vehicle, or any other device or equipment (sensor device, etc.) having a wireless communication function. The terminal device 100 may also be referred to as a wireless communication device, a communication device, a receiving device, a mobile station, a UE (User Equipment), a user device, etc.

[0018] The base station device 200 may be configured, for example, as being divided into a CU (Centralized Unit), a DU (Distributed Unit), and an RU (Radio Unit). The CU is connected to a core network. The DU is connected to the terminal device 100 via the RU, for example. The communication path between the CU and the DU is realized by, for example, a fronthaul interface (F1 interface). Multiple DUs may be connected to one CU.

[0019] The base station device 200-1 is, for example, a device that is wirelessly connected to the terminal device 100 and performs wireless communication (first base station device). Specifically, the base station device 200-1 is, for example, an eNodeB (eNB) or a gNodeB (gNB). Furthermore, in order to transmit and receive base station device information, each of the base station devices 200 is physically or logically connected via an Xn interface if it is a gNodeB, or via an X2 interface if it is an eNodeB.

[0020] An area (coverage area) formed by the base station device 200 may be called a "cell." E-UTRA and 5G are cellular communication systems constructed by multiple cells. As a wireless communication system according to an embodiment of the present invention, either a time division duplex (TDD) or a frequency division duplex (FDD) method may be applied, and different methods may be applied to different cells.

[0021] Hereinafter, the cell configured by the base station device 200-1 will also be referred to as a normal cell 200-1. The normal cell 200-1 is, for example, a cell that does not support NES or an NES cell that does not apply power saving technology. As shown in FIG. 1, the normal cell 200-1 configures, for example, a communication area A200-1 in which wireless communication is possible. Furthermore, a terminal device 100 located within the range of the communication area A200-1 can perform wireless communication with the normal cell 200-1, for example.

[0022] The base station device 200-2 is, for example, another device that is wirelessly connected to the terminal device 100 and performs wireless communication (second base station device). Specifically, the base station device 200-2 is, for example, an eNodeB (eNB) or a gNodeB (gNB). A cell configured by the base station device 200-2 is also referred to as an NES cell 200-2. The NES cell 200-2 transitions to a state (sleep state) in which power consumption can be reduced by applying a predetermined power-saving technique, for example, in accordance with instructions from the normal cell 200-1 or another control device. Then, in the sleep state, the NES cell 200-2 achieves power saving by, for example, halting transmission and reception of all but predetermined physical signals and physical channels and cutting off standby power of wireless devices within the base station device 200. The predetermined physical signals and physical channels are, for example, the PDCCH and PDSCH related to reception of SIB1 (described below).

[0023] The sleep state is, for example, a state in which some of the functions related to transmission and reception of the base station device 200 are stopped, and at the same time, power supply to internal devices related to transmission and reception is suppressed, and at least some messages transmitted by the base station device 200 and corresponding physical signals and physical channels are not transmitted or received. Furthermore, for example, when the sleep state is released (application of a predetermined power saving technology is stopped) or when the sleep state is temporarily released, the NES cell 200-2 enters a non-sleep state and transitions to a cell (e.g., a normal cell) in which normal wireless communication is possible. The NES cell 200-2 then constitutes, for example, a communication area A200-2 in which wireless communication is possible, as shown in FIG. 1 . Furthermore, a terminal device 100 located within the range of the communication area A200-2 can, for example, perform wireless communication with the NES cell 200-2.

[0024] The terminal device 100 is a communication device that is wirelessly connected to the base station device 200-1 or the base station device 200-2 and transmits and receives data. Specifically, the terminal device 100 is, for example, a smartphone or a tablet terminal. The terminal device 100 is also a communication device that supports the NES function, that is, a communication device that supports the NES function.

[0025] The NES cell may include, for example, a base station device 200 that has transitioned to a sleep state and a base station device 200 that may transition to a sleep state.

[0026] Furthermore, the normal cell 200-1 and the NES cell 200-2 may be cells under the control of the same base station device, or may be cells under the control of different base station devices.

[0027] The terminal device 100 and the base station device 200 transmit and receive radio resource control (RRC) messages (also called RRC signaling) in a radio resource control (RRC) layer. Also, the terminal device 100 and the base station device 200 transmit and receive medium access control (MAC) control elements (MAC CEs) in a medium access control (MAC) layer.

[0028] The RRC message is transmitted as an RRC Protocol Data Unit (PDU), and a common control channel (CCCH), a dedicated control channel (DCCH), a paging control channel (PCCH), a broadcast control channel (BCCH), a multicast control channel (MCCH), or the like is used as a logical channel (LCH) to which the RRC message is mapped.

[0029] The MAC CE is transmitted as a MAC PDU (or MAC subPDU). A MAC subPDU is equivalent to a service data unit (SDU) in the MAC layer plus, for example, 8 bits of header information, and a MAC PDU includes one or more MAC subPDUs.

[0030] The physical channels and physical signals according to the embodiment include a synchronization signal (Primary Synchronization Signal, Secondary Synchronization Signal), a Physical Broadcast Channel (PBCH), a Physical Random Access Channel (PRACH), a Physical Downlink Control Channel (PDCCH), a Channel State Information Reference Signal (CSI-RS), and a Physical Uplink Control Channel (PUCCH). There are at least a physical downlink shared channel (PDSCH: Physical Downlink Shared Channel), a physical uplink shared channel (PUSCH: Physical Uplink Shared Channel), a scheduling reference signal (SRS: Scheduling Reference Signal), and a demodulation reference signal (DMRS: Demodulation Reference Signal), but detailed description thereof will be omitted.

[0031] In addition, the PDCCH has downlink control information (DCI) including radio resource scheduling information, power control information, demodulation method, HARQ (Hybrid Automatic Repeat reQuest) information, etc., set for each terminal device 100 or for each group of terminal devices 100, and it becomes possible to acquire the PDSCH by acquiring the DCI.

[0032] (On-demand SIB1) On-demand SIB1 is one of the power saving techniques applied to the base station device 200, and is a method of transmitting SIB1, which is one piece of periodically transmitted broadcast information, based on a request from the terminal device 100. The content included in On-demand SIB1 includes at least the setting information (radio connection information (cell common resource information, cell selection criteria information, cell access information, etc.)) notified in the conventional SIB1, and may further include UL-WUS setting information (described later) indicating the transmission setting of UL-WUS, which is a signal for requesting On-demand SIB1. The base station device 200 may be configured to similarly transmit system information other than On-demand SIB1 (SIB2, SIB3, ...) on demand.

[0033] In order to receive the on-demand SIB1 of the base station device 200 (NES cell 200-2), the terminal device 100 acquires transmission resource information of the PDCCH acquired from a master information block (MIB) transmitted in a synchronization signal / PBCH block (SSB) used for downlink synchronization control of the cell. Then, the terminal device 100 monitors the PDCCH in the acquired transmission resource and acquires the PDSCH (on-demand SIB1) indicated by the DCI of the detected PDCCH.

[0034] (Configuration example of terminal device 100) Fig. 2 is a diagram showing a configuration example of the terminal device 100. The terminal device 100 has, for example, a CPU (Central Processing Unit) 110, storage 120, memory 130, and a wireless communication circuit 150. Note that the functional configuration of the terminal device 100 shown in Fig. 2 is merely an example, and the functional divisions and names of each functional block may be different as long as the operations according to the embodiment can be executed.

[0035] The storage 120 is, for example, an auxiliary storage device that stores programs and data, and may be configured with a flash memory, a hard disk drive (HDD), a solid state drive (SSD), etc. The storage 120 may be configured to store, for example, a terminal communication program 121 and a determination control program 122.

[0036] The memory 130 is, for example, an area into which programs stored in the storage 120 are loaded. Note that the memory 130 may also be used as an area in which programs store data.

[0037] The wireless communication circuit 150 is, for example, a circuit that performs wireless communication with the base station device 200. The wireless communication circuit 150 may have an antenna 151. The antenna 151 may include one or more directional antennas that can control the direction of transmission and reception of radio waves. The wireless communication circuit 150 is also capable of changing the transmission power.

[0038] The CPU 110 is a processor that, for example, loads a program stored in the storage 120 into the memory 130 and executes it to configure each unit and realize each process.

[0039] The CPU 110 can execute the terminal communication program 121 to configure a receiving unit and a transmitting unit and perform terminal communication processing. The terminal communication processing is processing executed in the terminal device 100 to perform wireless communication to establish a wireless connection between the terminal device 100 and the base station device 200.

[0040] The CPU 110, for example, executes the determination control program 122 to construct a determination control unit (hereinafter also simply referred to as a processing unit) and perform the determination control process. The determination control process is, for example, a process that is performed in response to receiving UL-WUS (UpLink-Wake Up Signal) configuration information from the normal cell 200-1. The UL-WUS configuration information (UL-WUS configuration) includes, for example, the physical cell ID (IDentifier) ​​of the NES cell 200-2, a frequency, information related to the PRACH, and the like. Specifically, the determination control process is, for example, a process that determines (determines, confirms, identifies) the validity of the UL-WUS configuration information received from the normal cell 200-1, and also applies the result of the determination on the validity of the UL-WUS configuration information to the determination of the validity of the on-demand SIB1.

[0041] (Configuration example of base station device 200) Fig. 3 is a diagram showing a configuration example of the base station device 200. The base station device 200 has, for example, a CPU 210, a storage 220, a memory 230, and a wireless communication circuit 250. Note that the functional configuration of the base station device 200 shown in Fig. 3 is merely an example, and the functional divisions and names of each functional block may be different as long as the operations according to the embodiment can be executed.

[0042] The storage 220 is, for example, an auxiliary storage device that stores programs and data, and may be configured with a flash memory, HDD, SSD, etc. The storage 220 stores, for example, a base station communication program 221.

[0043] The memory 230 is, for example, an area into which programs stored in the storage 220 are loaded. Note that the memory 230 may also be used as an area in which programs store data.

[0044] The wireless communication circuit 250 is, for example, a device that performs wireless communication with the terminal device 100. The wireless communication circuit 250 may have an antenna 251. The antenna 251 may include one or more directional antennas that are capable of controlling the direction of transmission and reception of radio waves.

[0045] The CPU 210 is a processor that, for example, loads a program stored in the storage 220 into the memory 230 and executes it to configure each unit and realize each process.

[0046] The CPU 210 can execute, for example, the base station communication program 221 to configure a receiving unit and a transmitting unit and perform base station communication processing. The base station communication processing is processing executed in the base station device 200 to perform wireless communication with the terminal device 100. Specifically, in the base station communication processing, for example, the base station device 200 can establish a wireless connection between the terminal device 100 and the base station device 200, transmit data to the terminal device 100, and receive data from the terminal device 100.

[0047] (UL-WUS Setting Information) The UL-WUS setting information includes some or all of the following information: cell information identifying a cell transmitting UL-WUS (physical cell ID, downlink frequency information, etc.), information related to UL-WUS transmission (PRACH resource information, SSB reception power threshold, TDD UL / DL slot setting, uplink frequency, etc.), information related to SIB1 reception (SSB subcarrier offset information, PDCCH resource information, etc.), and information related to PRACH response reception (reception window length, reception start offset information, etc.), and may further include cell selection criterion information (RSRP threshold, etc.). The terminal device 100 may determine whether the base station device 200 is a normal cell 200-1 or an NES cell 200-2 based on the cell information.

[0048] (Determination control process in the first embodiment) Next, an example of the determination control process in the first embodiment will be described. Fig. 4 is a diagram showing an example of the sequence of the determination control process in the first embodiment. Fig. 5 is an example of a flowchart of the determination control process in the first embodiment.

[0049] As shown in FIG. 4, the NES cell 200-2 transmits, for example, an inter-base station device message including UL-WUS (UpLink-Wake Up Signal) setting information to the normal cell 200-1 (step S11). The NES cell 200-2 takes care to synchronize the UL-WUS setting information and on-demand SIB1 of the normal cell 200-1 and the NES cell 200-2. That is, when the UL-WUS setting information or the on-demand SIB1 is updated, the NES cell 200-2 synchronizes the information of the normal cell 200-1 with the information of the NES cell 200-2 using the inter-base station device message. Hereinafter, the UL-WUS setting information is also referred to as first information.

[0050] Then, the normal cell 200-1 transmits the UL-WUS setting information received in step S11 to, for example, the terminal device 100 camped on the normal cell 200-1 (steps S12 and S13). When the normal cell 200-1 receives UL-WUS setting information from multiple NES cells 200-2, the normal cell 200-1 may transmit the UL-WUS setting information including multiple pieces of UL-WUS setting information in step S13 by including information that can identify each NES cell 200-2 (for example, a physical cell ID and frequency information). The normal cell 200-1 may broadcast one or more pieces of UL-WUS setting information to the terminal device 100 as broadcast information (system information) within the cell, or may notify the terminal device 100 using an individual RRC message, a MAC CE, or the physical downlink control channel PDCCH. When the terminal device 100 receives (acquires) the UL-WUS setting information from the normal cell 200-1, it stores (holds, saves) the received UL-WUS setting information for each cell in a storage unit (not shown).

[0051] Next, the terminal device 100 can transmit a UL-WUS to the NES cell 200-2 based on the UL-WUS configuration information received in step S13 (step S14). The UL-WUS is an uplink signal (signal) that is transmitted when conditions are met in the terminal device 100 and requests the NES cell 200-2 to transmit an On-demand SIB1. The terminal device 100 may determine that it is permitted to transmit the UL-WUS when (1) the base station device 200 is the NES cell 200-2 (On-demand SIB1 transmitting cell), (2) the corresponding UL-WUS configuration information has been acquired, (3) a valid On-demand SIB1 for the NES cell 200-2 is not held (stored), and (4) the cell reception quality (RSRP, etc.) of the NES cell 200-2 satisfies the cell selection criteria.

[0052] UL-WUS may be realized by allocating dedicated resources as PRACH. For example, it may be realized by reserving time / frequency resources of the PRACH or part of the preamble information as UL-WUS dedicated resources. The reserved resource information is configured in the terminal device 100 from the normal cell 200-1 as part of the UL-WUS configuration information. Hereinafter, the On-demand SIB1 is also referred to as second information.

[0053] Thereafter, when responding to the UL-WUS received in step S14 (that is, when resuming transmission of the stopped On-demand SIB1), the NES cell 200-2 transmits the On-demand SIB1 to the terminal device 100 (step S15). Note that when the terminal device 100 receives the On-demand SIB1 from the NES cell 200-2, it stores the received On-demand SIB1 in a storage unit. The NES cell 200-2 does not need to receive the UL-WUS in step S14, and even when it receives the UL-WUS, it may ignore the request without responding to it.

[0054] The terminal device 100 attempts to receive the On-demand SIB1 transmitted in step S15. If the terminal device 100 successfully receives the On-demand SIB1, it camps on the NES cell 200-2 based on the cell information notified in the On-demand SIB1 (step S16). If the terminal device 100 is unable to receive the On-demand SIB1 in step S15, or if the information indicated in the On-demand SIB1 includes bit information (barring information) instructing prohibition of camping on the cell, it does not need to camp on the NES cell 200-2 (not shown).

[0055] The terminal device 100 camps on the NES cell 200-2 and, if necessary, performs a process (hereinafter also referred to as a validity determination process) to determine the validity of the UL-WUS setting information received in step S13 and the On-demand SIB1 received in step S15 (step S17).

[0056] For example, if the terminal device 100 moves out of service area after step S16 and then returns from out of service area, the terminal device 100 needs to determine whether the UL-WUS configuration information received in step S13 and / or the On-demand SIB1 received in step S15 are the latest, in other words, whether the UL-WUS configuration information or the On-demand SIB1 corresponding to the NES cell 200-2 has been updated while the terminal device 100 was out of service area. Therefore, the terminal device 100 performs a validity determination process for the UL-WUS configuration information and / or the On-demand SIB1. Details of the validity determination process in the terminal device 100 will be described below.

[0057] 5, the terminal device 100 may determine (judgment, confirmation, identification) whether or not it is validity determination timing at the start of processing (NO in step S101). The validity determination timing is performed by the terminal device 100 at a timing when a predetermined condition is satisfied. The predetermined condition may be, for example, the timing when the terminal device 100 goes out of service and then returns from out of service, or the timing when the terminal device 100 is selecting a cell (cell selection) after returning from out of service, or the timing when UL-WUS setting information is acquired, or the timing when On-demand SIB1 is acquired, or the timing when a certain time (for example, 3 hours) has elapsed after acquiring the UL-WUS setting information or On-demand SIB1, or the timing when the NES cell 200-2 is reselected by the RRC reconnection procedure.

[0058] If it is determined that the validity determination timing has arrived (YES in step S101), the terminal device 100 determines whether or not the On-demand SIB1 corresponding to the NES cell 200-2 has been acquired (step S102).

[0059] As a result of the determination, if it is determined that the corresponding On-demand SIB1 has been acquired (YES in step S102), the terminal device 100 continues to hold (store) the On-demand SIB1 that has been determined to have been acquired (step S103).

[0060] Specifically, for example, if the validity determination process is performed after step S15, the terminal device 100 receives the on-demand SIB1 in step S15. In this case, the terminal device 100 continues to hold the on-demand SIB1 received in step S15.

[0061] In this case, the terminal device 100 temporarily determines that the On-demand SIB1 determined to have been acquired is not valid, and stops applying the On-demand SIB1 corresponding to the NES cell 200-2 (step S104).

[0062] On the other hand, if it is determined that the corresponding On-demand SIB1 has not been acquired (NO in step S102), the terminal device 100 does not need to perform the processes in steps S103 and S104.

[0063] Next, the terminal device 100 determines the validity of the acquired UL-WUS setting information (step S105). Specifically, the terminal device 100 determines the validity of the UL-WUS setting information stored in the storage unit.

[0064] More specifically, as a first method, for example, the terminal device 100 may determine the validity by comparing information stored in the storage unit with information acquired from the normal cell 200-1 or the NES cell 200-2. When at least a portion of the information included in the On-demand SIB1 acquired from the NES cell 200-2 matches a portion of the information in the On-demand SIB1 of the same NES cell 200-2 stored in the storage unit, the terminal device 100 may determine that the information in the On-demand SIB1 stored in the storage unit and the corresponding UL-WUS setting information are each valid. Furthermore, if at least a portion of the information included in the UL-WUS setting information acquired from the normal cell 200-1 matches the UL-WUS setting information of the same NES cell 200-2 stored in the memory unit, the terminal device 100 may determine that the UL-WUS setting information stored in the memory unit and the information of the corresponding On-demand SIB1 are each valid.

[0065] On the other hand, for example, if the acquired information does not match at least a portion of the information included in the On-demand SIB1 stored in the storage unit, the terminal device 100 may determine that the On-demand SIB1 stored in the storage unit is invalid. Also, if the acquired information does not match at least a portion of the information included in the UL-WUS setting information stored in the storage unit, the terminal device 100 may determine that the UL-WUS setting information stored in the storage unit is invalid.

[0066] Furthermore, as a second method, for example, the terminal device 100 may reacquire the corresponding UL-WUS configuration information from the normal cell 200-1, overwrite the UL-WUS configuration information in the storage unit with the reacquired UL-WUS configuration information, and simultaneously determine that the UL-WUS configuration information is valid. If the corresponding UL-WUS configuration information can be reacquired from the NES cell 200-2, the UL-WUS configuration information may be reacquired from the NES cell 200-2. If the corresponding UL-WUS configuration information cannot be acquired, the terminal device 100 may determine that the UL-WUS configuration information stored in the storage unit is invalid.

[0067] As a second method, number information (hereinafter also referred to as a value tag) capable of determining the validity of the UL-WUS configuration information may be used. The base station device 200 (normal cell 200-1) sets a value tag as numerical information that is incremented each time the UL-WUS configuration information is updated for each corresponding UL-WUS configuration information (i.e., for each NES cell 200-2), and notifies the terminal device 100. The value tag may be, for example, information indicating 0 to 3 using two bits by using binary numbers, information indicating 0 to 7 using three bits, or information indicated by more bits.

[0068] When the UL-WUS configuration information stored in the storage unit includes a value tag, the terminal device 100 determines the validity of the UL-WUS configuration information stored in the storage unit by referencing the value tag included in the UL-WUS configuration information stored in the storage unit and the value tag included in the UL-WUS configuration information acquired from the normal cell 200-1 or the NES cell 200-2. For example, when the value of the value tag stored in the storage unit matches the value of the reacquired value tag, the terminal device 100 determines that the UL-WUS configuration information stored in the storage unit is valid. On the other hand, when the value of the value tag stored in the storage unit does not match the value of the reacquired value tag, for example, the terminal device 100 determines that the UL-WUS configuration information stored in the storage unit is invalid.

[0069] Then, when it is determined that the acquired UL-WUS configuration information is not valid (YES in step S106), the terminal device 100 determines whether or not the On-demand SIB1 has been acquired from the NES cell 200-2 (step S107).

[0070] As a result of the determination, if the On-demand SIB1 has been acquired from the NES cell 200-2 (YES in step S107), the terminal device 100 determines that the acquired On-demand SIB1 is invalid (step S108). At this time, the terminal device 100 may release the On-demand SIB1 determined to be invalid, may add an information bit indicating invalidity to the storage unit, may exclude the corresponding cell from candidate cells for cell selection, or may consider the cell as a barred cell temporarily or until a predetermined time (for example, 300 seconds) has elapsed.

[0071] On the other hand, if it is determined that the On-demand SIB1 has not been acquired from the NES cell 200-2 (NO in step S107), the terminal device 100 does not need to perform the process of step S108, for example.

[0072] Then, after step S108, or if it is determined in step S107 that the On-demand SIB1 has not been acquired, the terminal device 100 ends the validity determination process.

[0073] 4, if it is determined in step S17 that the acquired UL-WUS configuration information is invalid (YES in step S17), the terminal device 100 camped on the NES cell 200-2 will be unable to continue camping on the NES cell 200-2 as a suitable cell because the SIB1 (On-demand SIB1) of the NES cell 200-2 is determined to be invalid. The terminal device 100 will then regard the NES cell 200-2 as an acceptable cell and will camp on another suitable cell, such as the normal cell 200-1 (step S18).

[0074] The terminal device 100 that has camped on the normal cell 200-1 then performs the same processes as in steps S13 to S16 as necessary (steps S19 to S22).

[0075] Furthermore, if the terminal device 100 determines, for example, in step S106 that the acquired UL-WUS setting information is valid (NO in step S106 (step S17)), it skips steps S18 to S22 and continues camping on NES 200-2.

[0076] In addition, for example, when a RLF (Radio Link Failure) procedure or an RRC re-establishment procedure is started, the terminal device 100 may determine that either or both of the UL-WUS configuration information and / or the On-demand SIB1 determined to have been acquired are invalid at the start timing of the above-mentioned procedure. At this time, the terminal device 100 may lower the frequency priority of the NES cell 200-2.

[0077] Furthermore, for example, when the terminal device 100 is camped on the NES cell 200-2, if the terminal device 100 determines that the On-demand SIB1 that has been determined to have been acquired is invalid, the base station device 200 may determine that the corresponding acquired UL-WUS configuration information is invalid. In order to ensure the validity of the UL-WUS configuration information corresponding to the NES cell 200-2, the base station device 200 may notify the terminal device 100 of the cell camped on the NES cell 200-2 of an update of SIB1 (On-demand SIB1).

[0078] Furthermore, for example, when the terminal device 100 is not camped in the NES cell 200-2, if the terminal device 100 determines that the on-demand SIB1 that has been determined to have been acquired is invalid, the terminal device 100 may ignore the on-demand SIB1 that has been acquired.

[0079] Furthermore, the base station device 200 may include the UL-WUS setting information in an individual RRC message (e.g., RRC Release) and transmit the same to the terminal device 100. The base station device 200 may set, for example, information indicating the validity period of the corresponding UL-WUS setting information (RRC timer (e.g., T370)) in the RRC message. The terminal device 100 may start counting the validity period of the UL-WUS setting information at the timing of receiving the RRC message, and may consider the UL-WUS setting information invalid when the validity period expires.

[0080] In addition, for example, when the terminal device 100 performs cell reselection (Cell Reselection) from the normal cell 200-1 to another cell (a cell other than the NES cell 200-2), the terminal device 100 may regard the UL-WUS setting information received by an individual RRC message as invalid.

[0081] In this way, when the terminal device 100 acquires the UL-WUS setting information corresponding to the NES cell 200-2 from the normal cell 200-1, it performs a process of determining the validity of the UL-WUS setting information based on predetermined conditions, and can associate the result of the determination of the validity with the result of the determination of the validity of the On-demand SIB1 in a one-to-one correspondence.

[0082] (Determination Control Process in Second Embodiment) Next, an example of the determination control process in the second embodiment will be described. FIG. 6 is a diagram showing an example of the sequence of the determination control process in the second embodiment. Note that a description of configurations, functions, or procedures common to the first embodiment will be omitted. That is, the following mainly describes the points that are different from the first embodiment.

[0083] As shown in FIG. 6, the NES cell 200-2 transmits, for example, an inter-base station device message including UL-WUS setting information to the normal cell 200-1 (step S31).

[0084] Then, the normal cell 200-1 transmits the UL-WUS setting information received in step S31 to, for example, the terminal device 100 camped on the normal cell 200-1 (steps S32 and S33). The normal cell 200-1 may broadcast one or more pieces of UL-WUS setting information to the terminal device 100 as broadcast information (system information) within the cell, or may notify the terminal device 100 using an individual RRC message, may notify the terminal device 100 using a MAC CE, or may notify the terminal device 100 using the physical downlink control channel PDCCH. When the terminal device 100 receives the UL-WUS setting information from the normal cell 200-1, it stores the received UL-WUS setting information for each cell in a storage unit (not shown).

[0085] Here, the terminal device 100 performs a validity determination process to determine the validity of the UL-WUS setting information received in step S33, as necessary (step S34).

[0086] For example, if the terminal device 100 goes out of service after step S33 and then recovers from being out of service, the terminal device 100 needs to determine whether the UL-WUS setting information received in step S33 is the latest, in other words, whether the UL-WUS setting information corresponding to the NES cell 200-2 has been updated while the terminal device 100 was out of service. Therefore, the terminal device 100 performs the validity determination process described in FIG. 5 on the UL-WUS setting information.

[0087] Then, for example, if the UL-WUS setting information is invalid in step S106 described in FIG. 5, the terminal device 100 may, if necessary, perform processing similar to steps S13 to S16 described in FIG. 4 as processing from steps S35 to S38.

[0088] In addition, if the terminal device 100 determines, for example, in step S106 that the acquired UL-WUS setting information is valid (NO in step S106), it can perform the processes from step S36 to step S38 without performing the process in step S35.

[0089] (Determination Control Process in Third Embodiment) Next, an example of the determination control process in the third embodiment will be described. Fig. 7 is a diagram showing an example of the sequence of the determination control process in the third embodiment. Note that a description of configurations, functions, or procedures common to the first and second embodiments will be omitted. That is, the following description will mainly focus on the differences from the first and second embodiments.

[0090] As shown in FIG. 7, the NES cell 200-2 transmits, for example, an inter-base station device message including UL-WUS setting information to the normal cell 200-1 (step S41).

[0091] Then, the terminal device 100 performs a cell selection procedure (Stored Cell selection) in the case where system information (System Information) of a cell (candidate cell) that is a candidate for cell selection has already been acquired, and after camping on the normal cell 200-1, performs a validity determination process to determine the validity of the UL-WUS setting information stored in the storage unit, as necessary (steps S42, S43, and S44).

[0092] For example, when the NES cell 200-2 is selected immediately after power-on or when a cell is selected from another system, the terminal device 100 needs to determine whether the stored UL-WUS setting information is the latest, in other words, whether the stored UL-WUS setting information and / or the On-demand SIB1 have been updated. Therefore, the terminal device 100 performs the validity determination process described in FIG. 5 on the UL-WUS setting information and / or the On-demand SIB1.

[0093] Then, for example, if the UL-WUS setting information is invalid in step S106 described in FIG. 5, the terminal device 100 may, if necessary, perform processing similar to steps S13 to S16 described in FIG. 4 as processing from steps 45 to S48.

[0094] In addition, if the terminal device 100 determines, for example, in step S106 that the acquired UL-WUS setting information is valid (NO in step S106), it can perform the processes from step S46 to step S48 without performing the process in step S45.

[0095] (Determination Control Process in the Fourth Embodiment) Next, an example of the determination control process in the fourth embodiment will be described. FIG. 8 is a diagram showing an example of the sequence of the determination control process in the fourth embodiment. Note that a description of configurations, functions, or procedures common to the first to third embodiments will be omitted. That is, the following mainly describes the differences from the first to third embodiments.

[0096] As shown in FIG. 8, the NES cell 200-2 transmits, for example, an inter-base station device message including UL-WUS setting information to the normal cell 200-1 (step S51).

[0097] Then, the terminal device 100 performs a cell selection procedure (Stored Cell selection) in the case where system information (System Information) of a cell (candidate cell) that is a candidate for cell selection has already been acquired, and after camping on the normal cell 200-1, determines whether or not it is possible to acquire an on-demand SIB1 (SIB1) from the NES cell 200-2 (steps S52, S53, and S54).

[0098] As a result, for example, if it is determined that the on-demand SIB1 (SIB1) can be acquired from the NES cell 200-2, the terminal device 100 acquires the on-demand SIB1 (SIB1) from the NES cell 200-2 (step S55). On the other hand, if the on-demand SIB1 (SIB1) cannot be acquired from the NES cell 200-2 (NO in step S54), the terminal device 100 continues camping on the normal cell 200-1 (step S57).

[0099] Thereafter, the terminal device 100 performs a validity determination process to determine the validity of the UL-WUS setting information stored in the storage unit and the On-demand SIB1 (SIB1) received in step S53, as necessary (step S56).

[0100] For example, when the NES cell 200-2 is selected immediately after power-on or when a cell is selected from another system, the terminal device 100 needs to determine whether the stored UL-WUS setting information is the latest, in other words, whether the stored UL-WUS setting information and / or the On-demand SIB1 have been updated. Therefore, the terminal device 100 performs the validity determination process described in FIG. 5 on the UL-WUS setting information and / or the On-demand SIB1.

[0101] Then, for example, if the UL-WUS setting information is invalid in step S106 described with reference to FIG. 5, the terminal device 100 continues camping on the normal cell 200-1 (step S57).

[0102] Thereafter, the terminal device 100 may perform the same processes as steps S13 to S16 as the processes from steps S58 to S61 as necessary.

[0103] It should be noted that, for example, if the terminal device 100 determines in step S106 that the acquired UL-WUS setting information is valid (NO in step S106), it does not need to perform the processes from step S58 to step S61.

[0104] [Other Embodiments] The above-described embodiments are intended to facilitate understanding of the present invention and are not to be construed as limiting the present invention. The present invention may be modified or improved without departing from the spirit thereof, and the present invention also includes equivalents. Each method may be combined with another. The terminal device 100 and the base station device 200 may support any one of the methods, or may support multiple methods.

[0105] In addition, some of the messages in the sequence of each method may be transmitted out of order or in a different order. In addition, some of the messages in the sequence may not be transmitted. In addition, the messages in the sequence may be divided into multiple messages, or different notification methods may be applied. For example, the notification may be by an RRC message, a MAC CE, or L1 signaling (DCI), or a combination thereof.

[0106] Furthermore, what is described as a function or process of the terminal device 100 may be a function or process of the base station device 200. Furthermore, what is described as a function or process of the base station device 200 may be a function or process of the terminal device 100.

[0107] Although an example of a device has been described in each embodiment, the method of the present disclosure is not limited to cellular phones, smartphones, tablet terminals, base station devices, etc., but can be applied to other electronic devices, such as 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, etc.

[0108] 10: Wireless communication system 100: Terminal device 110: CPU 120: Storage 121: Terminal communication program 122: Determination control program 130: Memory 150: Wireless communication circuit 151: Antenna 200: Base station device 200-1: Normal cell 200-2: NES cell 210: CPU 220: Storage 221: Base station communication program 230: Memory 250: Wireless communication circuit 251: Antenna

Claims

1. A terminal device having: a receiving unit that receives first information transmitted from a first base station device and second information transmitted from a second base station device corresponding to an uplink signal of the terminal device based on the first information; and a processing unit that, when the first information is stored, determines whether the second information corresponding to the first information is valid based on a result of a determination as to whether the first information is valid.

2. The terminal device according to claim 1, wherein the first base station device periodically transmits the second information, and the second base station device transmits the second information based on a request from the terminal device instead of periodically transmitting the second information, and the terminal device transmits the uplink signal to the second base station device when requesting the second information based on the first information.

3. The terminal device according to claim 1, wherein the first information includes setting information related to reception of the second information.

4. The terminal device according to claim 3, wherein the first information is an UL-WUS (Uplink Wake-up signal) configuration corresponding to each of the second base station devices.

5. The terminal device according to claim 1, wherein the second information includes information regarding a wireless connection between the terminal device and the second base station device and the first information.

6. The terminal device according to claim 5, wherein the second information is an On-demand SIB1 (System Information Block Type 1).

7. The terminal device according to claim 1, wherein the processing unit determines that the second information corresponding to the first information is valid when it determines that the first information is valid, and determines that the second information corresponding to the first information is invalid when it determines that the first information is invalid.

8. The terminal device according to claim 7, wherein the processing unit, when determining that the first information is invalid, deletes the stored second information corresponding to the first information.

9. A base station device comprising: a transmitting unit that transmits first information to a terminal device via another base station device and transmits second information corresponding to an uplink signal of the terminal device based on the first information; a processing unit that synchronizes the first information of the base station device and the other base station device, thereby causing the terminal device to determine whether the first information is valid; and a receiving unit that receives the uplink signal of the terminal device based on the first information, which is transmitted in accordance with the result of the determination of the terminal device.

10. The base station device according to claim 9, wherein the processing unit sets number information that changes each time the first information is updated, and causes the terminal device to determine whether the first information is valid using the number information.

11. A wireless communication system having a terminal device, a first base station device, and a second base station device different from the first base station device, wherein the first base station device transmits first information to the terminal device, the second base station device transmits second information to the terminal device corresponding to the terminal device's uplink signal based on the first information, and when the terminal device stores the first information, it determines whether the second information corresponding to the first information is valid based on the result of determining whether the first information is valid.

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