Communication device, base station, and communication method

Abstract

A communication device (100) according to an embodiment comprises: a reception unit 112 that receives, from a serving cell, system information including information pertaining to a configuration for acquiring an on-demand SIB1; and a control unit 120. The information pertaining to the configuration for acquiring the on-demand SIB1 includes information for configuring an RAR window. On the basis of the information for configuring the RAR window and information indicating an SCS indicated by an MIB that is included in an SS / PBCH block received from a second cell, the control unit 120 determines the RAR window for receiving a random access response corresponding to a request for the on-demand SIB1.

Description

Communication Device, Base Station, and Communication Method Cross - Reference to Related Applications

[0001] This application is based on Patent Application No. 2024 - 174586 filed on October 3, 2024, claims the benefit of its priority, and all the contents of that patent application are incorporated herein by reference.

[0002] This disclosure relates to a communication device, a base station, and a communication method.

[0003] In the 3GPP (Registered Trademark. The same shall apply hereinafter) (Third Generation Partnership Project), which is a standardization project for mobile communication systems, network energy saving (NES) is being discussed. As one of the NESs, the introduction of System Information Block Type 1 (hereinafter, appropriately referred to as on - demand SIB1) transmitted in response to a request from a communication device is being considered (see, for example, Non - Patent Document 1). A cell that supports on - demand SIB1 (hereinafter, appropriately referred to as an NES cell) can save energy because it does not need to transmit SIB1 periodically.

[0004] In the acquisition procedure of on - demand SIB1, it is agreed that a communication device requests on - demand SIB1 by reusing the first message (so - called MSG1) in the random access procedure (see, for example, Non - Patent Document 1).

[0005] After transmitting MSG1 for requesting on - demand SIB1, the communication device can receive the on - demand SIB by receiving the second message (so - called MSG2), which is a response to MSG1, and considering that the request for on - demand SIB1 has been successful.

[0006] “R1 - 2406848” (On On - demand SIB1 for IDLE / INACTIVE mode UEs)

[0007] The communication device according to the first embodiment includes a receiving unit that receives system information from a first cell, which includes information regarding settings for acquiring an on-demand system information block type 1 (SIB1), and a control unit. The information regarding settings for acquiring the on-demand SIB1 includes information for setting a random access response (RAR) window. The control unit determines a RAR window for receiving a random access response corresponding to a request for the on-demand SIB1, based on the information for setting the RAR window and information indicating the subcarrier interval (SCS) indicated by the master information block (MIB) included in the SS / PBCH block received from the second cell.

[0008] The base station according to the second embodiment includes a transmitting unit that transmits system information, including information regarding settings for acquiring an on-demand system information block type 1 (SIB1), to a communication device in the first cell. The information regarding settings for acquiring the on-demand SIB1 includes information for setting a random access response (RAR) window. The information for setting the RAR window, together with information indicating the subcarrier interval (SCS) indicated by the master information block (MIB) included in the SS / PBCH block received from the second cell, is used by the communication device to determine the RAR window for receiving a random access response corresponding to the request for the on-demand SIB1.

[0009] The third aspect of the communication method is a communication method performed by a communication device. The communication method comprises the steps of: receiving system information from a first cell, which includes information regarding settings for acquiring an on-demand system information block type 1 (SIB1); determining a RAR window for receiving a random access response corresponding to a request for the on-demand SIB1, based on information for setting a random access response (RAR) included in the information regarding settings for acquiring the on-demand SIB1, and information indicating a subcarrier interval (SCS) indicated by a master information block (MIB) included in an SS / PBCH block received from a second cell.

[0010] The fourth aspect of the communication method is a communication method performed at a base station. This communication method includes a step of transmitting system information, including information regarding settings for acquiring an on-demand system information block type 1 (SIB1), from a first cell to a communication device. The information regarding settings for acquiring the on-demand SIB1 includes information for setting a random access response (RAR) window. The information for setting the RAR window, together with information indicating the subcarrier interval (SCS) indicated by the master information block (MIB) included in the SS / PBCH block received from the second cell, is used by the communication device to determine a RAR window for receiving a random access response corresponding to a request for the on-demand SIB1.

[0011] The purpose, features, and advantages of this disclosure will become clearer with reference to the attached drawings and the detailed description below. Figure 1 is a diagram showing the configuration of a mobile communication system according to an embodiment. Figure 2 is a diagram showing an example of the configuration of a protocol stack according to an embodiment. Figure 3 is a diagram showing the configuration of a UE according to an embodiment. Figure 4 is a diagram showing the configuration of a base station according to an embodiment. Figure 5 is a sequence diagram for explaining an example of operation according to an embodiment. Figure 6 is a flowchart (part 1) for explaining an example of operation according to an embodiment. Figure 7 is a flowchart (part 2) for explaining an example of operation according to an embodiment. Figure 8 is a flowchart (part 3) for explaining an example of operation according to an embodiment.

[0012] A mobile communication system according to an embodiment will be described with reference to the drawings. In the drawings, identical or similar parts are denoted by the same or similar reference numerals.

[0013] Existing random access procedures assume that the communication device receives MSG2 after pre-receiving SIB1, whereas the on-demand SIB1 acquisition procedure assumes that the communication device receives MSG2 without having received SIB1. However, since there is no defined operation for the communication device to receive MSG2 before receiving (on-demand) SIB1, there is a concern that the communication device may not be able to properly acquire on-demand SIB1.

[0014] One of the objectives of this disclosure is to provide a communication device, a base station, and a communication method that enable the communication device to appropriately acquire on-demand SIB1.

[0015] (System Configuration) First, the configuration of the mobile communication system 1 according to this embodiment will be described with reference to Figure 1. The mobile communication system 1 is, for example, a system that conforms to the 3GPP Technical Specifications (TS). In the following, the mobile communication system 1 will be described using as an example a 5th Generation System (5G system) of the 3GPP standard, that is, a mobile communication system based on NR (New Radio) radio access.

[0016] The mobile communication system 1 includes a network 10 and a user equipment (UE) 100 that communicates with the network 10. The network 10 includes an NG-RAN (Next Generation Radio Access Network) 20, which is a 5G radio access network, and a 5GC (5G Core Network) 30, which is a 5G core network.

[0017] UE100 is a communication device that communicates via base station 200. UE100 may be a device used by a user. UE100 may be a mobile device such as a smartphone or other mobile phone terminal, tablet terminal, notebook PC, communication module, or communication card. UE100 may be a vehicle (e.g., car, train, etc.) or a device installed thereon (e.g., Vehicle UE). UE100 may be a transport vehicle other than a vehicle (e.g., ship, airplane, etc.) or a device installed thereon (e.g., Aerial UE). UE100 may be a sensor or a device installed thereon. Note that UE100 may also be referred to by other names such as terminal, terminal device, mobile station, mobile terminal, mobile device, mobile unit, subscriber station, subscriber terminal, subscriber device, subscriber unit, wireless station, wireless terminal, wireless device, wireless unit, remote station, remote terminal, remote device, or remote unit. Furthermore, UE100 is just one example of a terminal, and terminals may include factory equipment, etc.

[0018] NG-RAN20 includes a plurality of base stations 200. Each base station 200 manages at least one cell. One or more base stations 200 may correspond to one or more cells. A base station 200 may be replaced by a cell, and a cell may be replaced by a base station 200. A cell constitutes the smallest unit of a communication area. One cell belongs to one frequency (carrier frequency). The term "cell" may represent a radio communication resource, or it may represent a communication target of UE100. Each base station 200 can perform radio communication with UE100 located within its own cell. Base stations 200 communicate with UE100 using the RAN protocol stack. Details of the protocol stack will be described later. Base stations 200 are also connected to other base stations 200 (which may be called adjacent base stations) via the Xn interface. Base stations 200 communicate with adjacent base stations via the Xn interface. Furthermore, the base station 200 provides NR user plane and control plane protocol termination for UE100 and is connected to 5GC30 via the NG interface. Such an NR base station 200 is sometimes referred to as gNodeB (gNB).

[0019] 5GC30 includes a core network device 300. The core network device 300 includes, for example, an AMF (Access and Mobility Management Function) and / or a UPF (User Plane Function). The AMF performs mobility management for the UE100. The UPF provides functions specifically for U-plane processing. The AMF and UPF are connected to the base station 200 via an NG interface.

[0020] (Example of protocol stack configuration) Next, an example of the protocol stack configuration according to this embodiment will be described with reference to Figure 2.

[0021] The protocol for the radio section between UE100 and base station 200 comprises a physical (PHY) layer, a MAC (Medium Access Control) layer, an RLC (Radio Link Control) layer, a PDCP (Packet Data Convergence Protocol) layer, and an RRC (Radio Resource Control) layer.

[0022] The PHY layer performs encoding and decoding, modulation and demodulation, antenna mapping and demapping, and resource mapping and demapping. Data and control information are transmitted between the PHY layer of UE100 and the PHY layer of base station 200 via a physical channel.

[0023] The MAC layer performs data priority control, retransmission processing using Hybrid ARQ (HARQ), and random access procedures. Data and control information are transmitted between the MAC layer of UE100 and the MAC layer of base station 200 via the transport channel. The MAC layer of base station 200 includes a scheduler. The scheduler determines the transport format for the uplink and downlink (transport block size, modulation and coding scheme (MCS)) and the resources to be allocated to UE100.

[0024] The RLC layer transmits data to the receiving RLC layer using the functions of the MAC layer and PHY layer. Data and control information are transmitted between the RLC layer of UE100 and the RLC layer of base station 200 via a logical channel.

[0025] The PDCP layer performs header compression / decompression, encryption / decryption.

[0026] A Service Data Adaptation Protocol (SDAP) layer may be provided as a layer above the PDCP layer. The SDAP layer maps IP flows, which are the units in which the core network performs Quality of Service (QoS) control, to wireless bearers, which are the units in which the Access Stratum (AS) performs QoS control.

[0027] The RRC layer controls the logical channel, transport channel, and physical channel in response to the establishment, re-establishment, and release of the radio bearer. RRC signaling for various settings is transmitted between the RRC layer of UE100 and the RRC layer of base station 200. If there is an RRC connection between the RRC layer of UE100 and the RRC layer of base station 200, UE100 is in the RRC connected state. If there is no RRC connection between the RRC layer of UE100 and the RRC layer of base station 200, UE100 is in the RRC idle state. If the RRC connection between the RRC layer of UE100 and the RRC layer of base station 200 is suspended, UE100 is in the RRC inactive state.

[0028] In UE100, the NAS layer, located above the RRC layer, performs session management and mobility management for UE100. NAS signaling is transmitted between the NAS layer of UE100 and the NAS layer of the core network device 300.

[0029] Furthermore, the UE100 has an application layer and other components in addition to the wireless interface protocol.

[0030] (Wireless Frame Configuration) In a 5G system, downlink and uplink transmissions are composed within wireless frames with a duration of 10ms. For example, a wireless frame is represented by a System Frame Number (SFN) from 0 to 1023. For example, a wireless frame consists of 10 subframes. For example, one subframe may be 1ms long. Also, one subframe may consist of one or more slots. For example, the number of symbols that make up one slot is usually 14 for a Cyclic Prefix (CP) and 12 for an extended CP. Also, the number of slots that make up one subframe changes according to the set subcarrier interval. For example, for a normal CP, if the subcarrier interval is set to 15 kHz, the number of slots per subframe is 1 (i.e., 14 symbols); if the subcarrier interval is set to 30 kHz, the number of slots per subframe is 2 (i.e., 28 symbols); if the subcarrier interval is set to 60 kHz, the number of slots per subframe is 4 (i.e., 56 symbols); and if the subcarrier interval is set to 120 kHz, the number of slots per subframe is 8 (i.e., 112 symbols). Also, for an extended CP, if the subcarrier interval is set to 60 kHz, the number of slots per subframe is 4 (i.e., 48 symbols). In other words, the number of slots constituting one subframe is determined based on the subcarrier interval set by the base station 200. Also, the number of symbols constituting one subframe is determined based on the subcarrier interval set by the base station 200. In other words, the number of symbols constituting a 1 ms subframe is determined based on the subcarrier interval set by the base station 200, and the length (length in the time direction) of each symbol changes.

[0031] (Configuration of User Device) Referring to Figure 3, the configuration of the UE100 according to this embodiment will be described. The UE100 includes a communication unit 110 and a control unit 120.

[0032] The communication unit 110 performs wireless communication with the base station 200 by transmitting and receiving radio signals to and from the base station 200. The communication unit 110 has at least one transmitting unit 111 and at least one receiving unit 112. The transmitting unit 111 and the receiving unit 112 may be configured to include a plurality of antennas and an RF (Radio Frequency) circuit. The antenna converts a signal into radio waves and radiates the radio waves into space. The antenna also receives radio waves in space and converts the radio waves into signals. The RF circuit performs analog processing of the signals transmitted and received via the antenna. The RF circuit may include a high-frequency filter, an amplifier, a modulator, and a low-pass filter, etc.

[0033] The control unit 120 performs various controls on the UE 100. The control unit 120 controls communication with the base station 200 via the communication unit 110. The operations of the UE 100 described above and below may be operations controlled by the control unit 120. The control unit 120 may include at least one processor capable of executing a program and a memory for storing the program. The processor may execute the program to perform the operations of the control unit 120. The control unit 120 may include a digital signal processor that performs digital processing of signals transmitted and received via the antenna and RF circuit. This digital processing includes processing of the RAN protocol stack. The memory stores the program executed by the processor, parameters related to the program, and data related to the program. Memory may include at least one of ROM (Read Only Memory), EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), RAM (Random Access Memory), and flash memory. All or part of the memory may be contained within the processor.

[0034] (Base station configuration) Referring to Figure 4, the configuration of the base station 200 according to this embodiment will be described. The base station 200 has a communication unit 210, a network communication unit 220, and a control unit 230.

[0035] The communication unit 210, for example, receives a radio signal from the UE 100 and transmits a radio signal to the UE 100. The communication unit 210 has at least one transmitting unit 211 and at least one receiving unit 212. The transmitting unit 211 and the receiving unit 212 may include an RF circuit. The RF circuit performs analog processing of the signals transmitted and received via the antenna. The RF circuit may include a high-frequency filter, an amplifier, a modulator, a low-pass filter, etc.

[0036] The network communication unit 220 transmits and receives signals to and from the network. For example, the network communication unit 220 receives signals from an adjacent base station connected via the Xn interface, which is an inter-base station interface, and transmits signals to the adjacent base station. The network communication unit 220 also receives signals from a core network device 300 connected via the NG interface, and transmits signals to the core network device 300.

[0037] The control unit 230 performs various controls on the base station 200. For example, the control unit 230 controls communication with the UE 100 via the communication unit 210. The control unit 230 also controls communication with nodes (e.g., adjacent base stations, core network devices 300) via the network communication unit 220. The operations of the base station 200 described above and below may be operations controlled by the control unit 230. The control unit 230 may include at least one processor capable of executing programs and a memory for storing programs. The processor may execute programs to perform the operations of the control unit 230. The control unit 230 may include a digital signal processor that performs digital processing of signals transmitted and received via the antenna and RF circuit. This digital processing includes processing of the RAN protocol stack. The memory stores programs executed by the processor, parameters related to the programs, and data related to the programs. All or part of the memory may be contained within the processor.

[0038] (Example of Operation) An example of operation according to this embodiment will be described with reference to Figures 5 to 8. Previously mentioned explanations may be omitted.

[0039] In Figure 5, UE100 may be in an RRC idle state or an RRC inactive state with respect to cell C1 managed by base station 200. Alternatively, UE100 may be in an RRC connected state with respect to cell C1. That is, the RRC state of UE100 may be an RRC idle state, an RRC inactive state, or an RRC connected state. Cell C1 may be a cell where UE100 is camping, or a cell that UE100 has (re)selected. Cell C1 may be a cell with which UE100 has established an RRC connection. That is, cell C1 may be a serving cell.

[0040] Cells C1 and C2 may be managed by the same base station 200. Cells C1 and C2 may each be managed by different base stations 200. For example, one base station 200 may manage both cell C1 and cell C2. A first base station may manage cell C1, and a second base station may manage cell C2. In this example, we will proceed with the explanation assuming that the first base station (hereinafter referred to as base station 201) manages cell C1 and the second base station (hereinafter referred to as base station 202) manages cell C2.

[0041] In this example, a cell that periodically broadcasts (i.e., transmits) System Information Block Type 1 (SIB1) is referred to as the first cell. The first cell may be a cell that does not support On-Demand SIB1 (i.e., On-Demand SIB1 functionality). The first cell may be a cell that broadcasts SIB1 without a request from UE100. The first cell may be referred to as an anchor cell. The first cell may be a general cell that does not transmit On-Demand SIB1. In this example, the first cell is cell C1. Cell C1 may be, for example, a primary cell (i.e., a P cell) for UE100.

[0042] In this example, a cell that does not periodically broadcast (i.e., transmit) System Information Block Type 1 (SIB1) is referred to as the second cell. The second cell may be a cell that transmits On-Demand SIB1. The second cell may also be a cell that supports On-Demand SIB1 (i.e., the functions of On-Demand SIB1). The second cell may initiate broadcasting of SIB1 based on a request from UE100. The second cell may be referred to as a non-anchor cell or as an NES cell. The second cell may be a special cell that transmits On-Demand SIB1. For example, the second cell (i.e., the base station 202 managing the second cell) may broadcast information indicating that it supports On-Demand SIB1. For example, information indicating that it supports On-Demand SIB1 may be included in MIB (i.e., SSB), SIB1, or system information other than SIB1 (system information block). Furthermore, information indicating that the second cell supports on-demand SIB1 may be transmitted from the first cell (i.e., the base station 201 managing the first cell) to the UE 100. For example, information indicating that it supports on-demand SIB1 may be included in the SIB1 request settings described later. Based on the information indicating that it supports on-demand SIB1, the UE 100 may perform operations related to the on-demand SIB1 request described later. In this example of operation, cell C2 is the second cell.

[0043] In this specification, communication between UE 100 and base station 200 (i.e., base stations 201 and 202) may also be communication with a cell. For example, base station 200 may transmit information / messages, etc., to UE 100 from (or within) a cell. For UE 100, receiving information / messages, etc., from a cell may also be receiving information / messages, etc., from base station 200. Similarly, base station 200 may receive information / messages, etc., from UE 100 via (or within) a cell. For UE, transmitting information / messages, etc., to a cell may also be transmitting information / messages, etc., to base station 200.

[0044] Step S110: The transmission unit 211 of the base station 201 transmits setting information for acquiring on-demand SIB1 (hereinafter referred to as SIB1 request setting information) from the cell C1 to the UE 100. The reception unit 112 of the UE 100 receives the SIB1 request setting from the cell C1.

[0045] The SIB1 request setting information may be information regarding settings for requesting on-demand SIB1 from a second cell (cell C2). The SIB1 request setting information may be a setting (i.e., information) used for transmitting information indicating a request for broadcasting of SIB1. The SIB1 request setting information may be setting information regarding a wake-up signal (WUS) for requesting on-demand SIB1. The wake-up signal may be referred to as an uplink wake-up signal (UL WUS). Hereinafter, simply transmitting information indicating a request for broadcasting of SIB1 is also described as transmitting a request. The SIB1 request setting information may be included in an RRC message. As shown in FIG. 5, the SIB1 request setting information may be included, for example, in SIB1 from the cell C1 (i.e., the SIB1 message). The SIB1 request setting information may be included in a system information block related to SIB of another cell. That is, the SIB1 request setting information may be included in a system information message (SI message, hereinafter also referred to as SIBX). The UE 100 may request the cell C1 to broadcast SIBX. The base station 201 may transmit SIBX including the SIB1 request setting information to the UE 100 in response to a request from the UE 100.

[0046] When the UE 100 is in the RRC connected state, the transmission unit 211 of the base station 201 may transmit an individual RRC message including SIB1 request setting information from the cell C1 to the UE 100. The reception unit 112 of the UE 100 may receive the individual RRC message from the cell C1. The individual RRC message may be an RRC message sent individually to each UE 100. The control unit 120 of the UE 100 may store (store) the SIB1 request setting information even after transitioning from the RRC connected state to the RRC idle state or the RRC inactive state. Details of the SIB1 request setting information will be described later.

[0047] Step S120: The transmission unit 211 of the base station 202 may transmit a master information block (MIB) from the cell C2 to the UE 100. The reception unit 112 of the UE 100 may receive the MIB from the cell C2. The MIB includes system information transmitted on the broadcast channel (BCH). Also, the MIB may be transmitted on the physical broadcast channel (PBCH). For example, the reception unit 112 of the UE 100 may receive a synchronization signal and a PBCH block (SSB: Synchronization Signal / PBCH block) in the cell C2, and receive the MIB in the PBCH of the SSB. The SSB may be a synchronization signal block (Synchronization Signal Block).

[0048] Note that the control unit 120 of the UE 100 may control to execute the process of step S130 without receiving the MIB from the cell C2. The control unit 120 may receive the MIB before step S110.

[0049] Step S130: The transmitter 111 of UE100 transmits a first message (MSG1) for an on-demand SIB1 request to cell C2 in the random access procedure based on the SIB1 request setting information. For example, the transmitter 111 of UE100 may transmit PRACH as MSG1 using the random access opportunity set in accordance with cell C2 and / or the random access preamble set in accordance with cell C2. The receiver 212 of base station 201 receives the MSG1 for the on-demand SIB1 request from UE100 in cell C2. Note that MSG1 may also be a preamble transmission for the random access procedure.

[0050] The SIB1 request setting information may include the following information. The control unit 120 of UE100 may send MSG1 to cell C2 based on the following information of the SIB1 request setting information.

[0051] The SIB1 request configuration information may include uplink resource information used to send the request. The uplink resource information may include, for example, configuration information for setting the uplink bandwidth portion (uplink BWP) for sending the request (hereinafter referred to as ULBWP information). The uplink resource information may also include configuration information used to identify random access parameters for sending the request (hereinafter referred to as RACH resource information).

[0052] ULBWP information may include, for example, information used to configure additional uplink bandwidth portions (not for the initial BWP) (e.g., BWP-Uplink information). ULBWP information may include, for example, information used to configure common parameters for the uplink BWP (e.g., BWP-UplinkCommon). ULBWP information may include BWP information (e.g., BWP) used to configure bandwidth portion parameters. BWP information may include at least one of the following: information indicating the frequency location and bandwidth of the bandwidth portion configured by the BWP information (e.g., locationAndBandwidth), information indicating the extended cyclic prefix for the bandwidth portion configured by the BWP information (e.g., cycloPrefix), and information indicating the subcarrier spacing for the bandwidth portion configured by the BWP information (e.g., subcarrierSpacing). Here, the information indicating the extended cyclic prefix may indicate whether an extended cyclic prefix is ​​used in the bandwidth portion set by the BWP information, or whether a normal cyclic prefix is ​​used. The information indicating the subcarrier spacing may also indicate the subcarrier spacing used for all channels and / or the reference signal in the bandwidth portion set by the BWP information.

[0053] The ULBWP information may include initial uplink BWP information (e.g., initialUplinkBWP) indicating the settings for the initial uplink BWP. The initial uplink BWP information may be information used only for on-demand SIB1 requests. Therefore, for example, an RRC message containing SIB1 request setting information may include initial uplink BWP information for initial access to the second cell, separate from the said initial uplink BWP information. Alternatively, the initial uplink BWP information for on-demand SIB1 requests may also be used for initial access to the second cell. The initial uplink BWP information may be the same for both on-demand SIB1 requests and initial access. In this case, the RRC message containing SIB1 request setting information does not need to include initial uplink BWP information for initial access to the second cell. In this embodiment, the RRC message may include system information messages and / or individual RRC messages.

[0054] RACH resource information may include information used to identify cell-specific random access parameters (e.g., RACH-ConfigCommon). RACH resource information may include information used to identify cell-specific random access parameters (e.g., RACH-ConfigCommon). RACH resource information may include information used to identify cell-specific random access parameters for both normal random access and beam failure recovery (e.g., RACH-ConfigGeneric). RACH resource information may be information used only for on-demand SIB1 requests. Therefore, for example, an RRC message containing SIB1 request setting information may include RACH resource information for initial access to the second cell, separate from the said RACH resource information. Alternatively, RACH resource information for on-demand SIB1 requests may also be used for initial access to the second cell. The RACH resource information may be the same for both the settings for on-demand SIB1 requests and the settings for initial access. In this case, the RRC message containing the SIB1 request setting information does not need to include the RACH resource information for initial access to the second cell.

[0055] In other words, the RACH resource information may include random access parameters used by UE100 to request on-demand SIB1. For example, the RACH resource information may include information for setting up random access opportunities for on-demand SIB1 requests. Random access opportunities may correspond to opportunities for physical random access channel (PRACH) transmission (i.e., transmission of message 1 in a random access procedure). In other words, the RACH resource information may include information for setting up time and / or frequency resources of the PRACH (indices corresponding to time and / or frequency resources). The RACH resource information may also include information for setting up the index of the random access preamble for on-demand SIB1 requests. For example, a random access preamble may be defined by 64 elements with indices from 0 to 63, and the random access preamble for on-demand SIB1 requests may be set by including information for setting the starting index of the random access preamble in the RACH resource information. In other words, UE100 may request a broadcast of on-demand SIB1 from cell C2 (i.e., the start of a broadcast) by sending a random access preamble during a random access opportunity on the uplink BWP. The RACH resource information may also include information for setting a period (RAR window) for receiving message 2 corresponding to the transmission of PRACH. For example, the period for receiving message 2 may be defined as the length of a slot, and UE100 may consider the random access procedure to have been successfully completed if it receives message 2 within that period in response to the transmission of PRACH. In other words, as will be described later, UE100 may consider the request for on-demand SIB1 to have been successfully completed if it receives message 2 within that period.

[0056] Uplink resource information may include information (e.g., si-RequestConfig) indicating the configuration of resources for message 1 used by UE100 to request SIB1 or an SI message for SIB1. Furthermore, uplink resource information may include information (e.g., SI-SchedulingInfo) containing information necessary for requesting SIB1 or an SI message for SIB1. Also, information (e.g., si-RequestConfig) indicating the configuration of resources for message 1 used by UE100 may include uplink resource information and / or information (e.g., SI-SchedulingInfo) containing information necessary for requesting SIB1 or an SI message for SIB1. For example, information (e.g., si-RequestConfig) indicating the configuration of resources for message 1 used by UE100 may correspond to SIB1 request configuration information. Base station 201 may configure UE 100 to request on-demand SIB1 by including SIB1 request setting information in the RRC message. That is, as described later, UE 100 may decide whether or not to send an on-demand SIB1 request. For example, UE 100 may request on-demand SIB1 if the RRC message includes SIB1 request setting information. Also, UE 100 does not have to request on-demand SIB1 if the RRC message does not include SIB1 request setting information. Furthermore, base station 201 may configure UE 100 to request on-demand SIB1 by including uplink resource information (e.g., random access parameters) in the SIB1 request setting information. That is, UE 100 may request on-demand SIB1 if the SIB1 request setting information includes uplink resource information. Furthermore, if the SIB1 request setting information does not include upstream link resource information, the UE100 does not need to make an on-demand SIB1 request.

[0057] The SIB1 request setting information may include a cell identifier corresponding to the second cell. The cell identifier is an identifier for identifying a cell. The cell identifier may be, for example, a physical cell identifier (e.g., physCellId). The cell identifier may be associated with uplink resource information. The uplink resource information associated with the cell identifier may be uplink resource information for the second cell identified by the cell identifier. For example, the SIB1 request setting information may include one or more cell identifiers corresponding to the second cell. That is, each of the one or more cell identifiers corresponding to the second cell may be associated with one or more uplink resource information. For example, the SIB1 request setting information may include a list of one or more cell identifiers corresponding to the second cell, and a list of one or more uplink resource information, and the one or more cell identifiers in the list may be associated with the order of the one or more uplink resource information in the list.

[0058] The SIB1 request setting information may include information about a set of synchronization signal (SS) bursts composed of SSBs from the second cell. For example, the information about the SS burst set may include information indicating the period of the SS burst set. Here, the SS burst set may be referred to as an SSB. The information about the SS burst set may also include information indicating the position in the time domain in which the SSB is actually transmitted. Furthermore, the information about the SS burst set may include information indicating the relationship (correspondence) between the SSB and the random access opportunity, and / or information indicating the threshold used for selecting the SSB. For example, the SIB1 request setting information may include information about one or more SS burst sets. That is, the SIB1 request setting information may associate one or more cell identifiers corresponding to the second cell with information about one or more SS burst sets. For example, the SIB1 request setting information may include a list of one or more cell identifiers corresponding to the second cell, and a list of information about one or more SS burst sets, and the order of the one or more cell identifiers included in the list may be associated with the order of the information about one or more SS burst sets included in the list.

[0059] The control unit 120 of UE 100 may select a random access opportunity to be used for requesting an on-demand SIB 1 based on information about the SS burst set. For example, UE 100 may determine a random access opportunity associated with an SSB based on information indicating the relationship (correspondence) between an SSB and a random access opportunity. Alternatively, UE 100 may measure the received power (e.g., reference signal power (RSRP)) based on the SSB, select an SSB with a received power higher than a threshold set by information indicating the threshold used for SSB selection, and select a random access opportunity associated with the selected SSB. UE 100 may request a broadcast of an on-demand SIB 1 (i.e., the start of a broadcast) by selecting a random access opportunity based on information about the SS burst set and transmitting a random access preamble at the selected random access opportunity.

[0060] The control unit 120 of UE 100 may omit or skip this step S130. The control unit 120 may not perform this step S130 (i.e., may omit or skip it) if it has performed, for example, the following steps and received a message for acknowledgment to MSG1. The control unit 120 may not perform this step S130 if it has performed, for example, the following steps before performing this step S130 and received a message for acknowledgment to MSG1. In this case, MSG1 may be transmitted, for example, from another UE 100. The control unit 120 may perform the following steps, for example, assuming that MSG1 was transmitted in a random access opportunity based on SIB1 request setting information. The control unit 120 may perform this step, for example, if it has performed the following steps and was unable to obtain an on-demand SIB1.

[0061] Step S140: The control unit 120 of the UE 100 may determine the parameters for receiving the MSG2. The control unit 120 of the UE 100 may determine at least one of the following as parameters for receiving the MSG2: subcarrier interval (SCS), PDCCH monitoring opportunity, random access response (RAR) window, and random access radio network temporary identifier (RA-RNTI). The following describes how the control unit 120 of the UE 100 determines the SCS, PDCCH monitoring opportunity, RAR window, and RA-RNTI, as shown in Figure 6.

[0062] Step S141: The control unit 120 may determine the SCS. The control unit 120 may determine the SCS by at least one of the following methods.

[0063] Firstly, the control unit 120 may determine the SCS based on the SIB1 request setting information. The SIB1 request setting information may include information related to the SCS (hereinafter referred to as SCS-related information). The SCS-related information may include information indicating the subcarrier spacing of the carrier (hereinafter referred to as SCS information (e.g., subcarrierSpacing)). The SCS information determines the subcarrier spacing.

[0064] Furthermore, SCS-related information may include information indicating a set of carriers with different subcarrier intervals (hereinafter referred to as SCS-specific carrier list information (e.g., scs-SpecificCarrierList)). SCS-specific carrier list information may consist of one or more pieces of information (hereinafter referred to as SCS-specific carrier information (e.g., SCS-SpecificCarrier)) that provide parameters for determining the position and width of the actual carrier or carrier bandwidth. Each piece of SCS-specific carrier information may include information indicating SCS information. The control unit 120 may determine the SCS based on the SCS-specific carrier list information. For example, the control unit 120 may determine the value indicated by one or more pieces of SCS information included in the SCS-specific carrier list information as the SCS. The control unit 120 may determine the maximum value among the one or more pieces of SCS information included in the SCS-specific carrier list information as the SCS.

[0065] Furthermore, the SCS-related information may include information used to set general parameters of the bandwidth portion (hereinafter referred to as BWP information (e.g., BWP)). The BWP information may include the SCS information and information indicating the frequency domain location and bandwidth of the bandwidth portion (e.g., locationAndBandwidth). The control unit 120 may determine the value indicated by the SCS information included in the BWP information as the SCS. For example, the control unit 120 may determine the SCS using the SCS information of the BWP information corresponding to the initial downlink BWP. The BWP identifier associated with the BWP information corresponding to the initial downlink BWP (hereinafter referred to as the BWP identifier (e.g., BWP-Id)) is 0.

[0066] SCS-related information may include information indicating the subcarrier spacing of the physical random access channel (PRACH) (hereinafter referred to as MSG1SCS information (e.g., msg1-SubcarrierSpacing)). The control unit 120 may determine the SCS based on the MSG1SCS information. For example, the control unit 120 may determine the value indicated by the MSG1SCS information as the SCS.

[0067] Secondly, the control unit 120 may determine the SCS based on the MIB. The MIB may include SCS-related information. The MIB may include information similar to the SIB1 request setting information described above. In the MIB, the SCS-related information may include information indicating a predetermined subcarrier interval (hereinafter referred to as SCS common information (e.g., subCarrierSpacingCommon)). The SCS common information may be used for at least one of SIB1, MSG2 / 4 and MSGB for initial access, paging, and broadcasting system information messages.

[0068] As SCS-related information included in the SIB1 request setting information and / or MIB, the SCS may be commonly set for the PDCCH monitoring opportunity, the start position of the RAR window, and / or the length of the RAR window. If the SCS is commonly set, the control unit 120 can determine the SCS using any of the SCS-related information for which the SCS is commonly set when determining the PDCCH monitoring opportunity, the start position of the RAR window, and / or the length of the RAR window. Alternatively, the SCS may be independently set for the PDCCH monitoring opportunity, the start position of the RAR window, and / or the length of the RAR window. If the SCS is independently set, the control unit 120 can determine the SCS using the (pre-specified) SCS-related information when determining the PDCCH monitoring opportunity, the start position of the RAR window, and / or the length of the RAR window.

[0069] SCS-related information may be set for one or more downlink bandwidth portions (BWPs). Therefore, SCS-related information may be associated with information indicating each downlink BWP. Each SCS-related information may indicate the SCS in the associated downlink BWP. SCS-related information may be set for only one downlink BWP. SCS-related information may be set for, for example, only the initial downlink BWP. SCS-related information may indicate the SCS for the initial downlink BWP. Also, SCS-related information may be set for the downlink. SCS-related information may indicate the SCS in the downlink. Also, SCS-related information may be set for SIB1, MSG2 / 4 and MSGB for initial access. SCS-related information may indicate the SCS for SIB1, MSG2 / 4 and MSGB for initial access.

[0070] The control unit 120 may decide whether to use the SCS-related information in the SIB1 request setting information or the SCS-related information in the MIB. The control unit 120 may also switch the SCS-related information used depending on the purpose. As shown in Figure 7, the control unit 120 may determine the SCS-related information as follows, for example.

[0071] Step S201: The control unit 120 may determine whether or not to acquire the on-demand SIB1. If the control unit 120 acquires the on-demand SIB1, it may execute the process in step S202. For example, if the control unit 120 requests and / or receives the on-demand SIB1, it may execute the process in step S202. If the control unit 120 does not have the on-demand SIB1 in its store, it may execute the process in step S202.

[0072] On the other hand, if the control unit 120 does not intend to acquire an on-demand SIB1, it may execute the process in step S205. For example, if the control unit 120 is performing initial access to cell C2, it may execute the process in step S205. Also, if the control unit 120 is holding an on-demand SIB1, it may execute the process in step S205.

[0073] Furthermore, the control unit 120 may retain the on-demand SIB1 after acquiring it. The control unit 120 may delete the retained on-demand SIB1 if it becomes invalid.

[0074] Step S202: The control unit 120 may determine whether the SIB1 request setting information includes SCS-related information. If the SIB1 request setting information includes SCS-related information, the control unit 120 may execute the process in step S203. On the other hand, if the SIB1 request setting information does not include SCS-related information, the control unit 120 may execute the process in step S204.

[0075] Step S203: The control unit 120 may use the SCS-related information in the SIB1 request setting information.

[0076] Step S204: The control unit 120 may use SCS-related information in the MIB. Therefore, if the SIB1 request setting information includes SCS-related information, the control unit 120 may determine the SCS based on the SCS-related information included in the SIB1 request setting information. If the SIB1 request setting information does not include SCS-related information, the control unit 120 may determine the SCS based on the SCS-related information included in the MIB.

[0077] Thus, the control unit 120 may switch between the SCS-related information (or SCS information) in the SIB1 request setting information and the SCS-related information (or SCS information) in the MIB as the information used to determine the SCS.

[0078] Note that the SCS information in the SIB1 request setting information and the SCS information in the MIB may be set to the same SCS, that is, they may indicate the same SCS.

[0079] Step S205: The control unit 120 may use the SCS-related information in SIB1. The control unit 120 of UE100 may use the stored SIB1 (on-demand SIB1) to determine the SCS.

[0080] SIB1 may include information used to set common parameters for the downlink BWP (hereinafter referred to as BWP downlink common information (e.g., BWP-DownlinkCommon)). The BWP downlink common information may include BWP information. The control unit 120 may use the SCS information included in the BWP information.

[0081] Furthermore, SIB1 may include information that provides basic parameters for the downlink carrier and transmission thereon (hereinafter referred to as frequency downlink information (e.g., FrequencyInfoDL)). The frequency downlink information may include SCS-specific carrier list information. As described above, the control unit 120 may determine the SCS using the SCS-specific carrier list information.

[0082] Thus, the control unit 120 may switch between the SIB1 request setting information and / or the SCS-related information (or SCS information) in the MIB and the SCS-related information (or SCS information) in the SIB1 as the information used to determine the SCS.

[0083] Note that the SCS information in the SIB1 request setting information and / or the SCS information in the MIB may be set to the same SCS, that is, they may indicate the same SCS.

[0084] The control unit 120 may determine the SCS based on the SCS-related information. The determined SCS may be used in at least one of the following steps S132 to S134.

[0085] Step S142: Returning to Figure 6, the control unit 120 may determine a PDCCH monitoring opportunity. The control unit 120 may determine a PDCCH monitoring opportunity for, for example, a Type 1-PDCCH CSS set. The control unit 120 may determine a PDCCH monitoring opportunity based on the SCS determined above.

[0086] The control unit 120 may determine that a PDCCH monitoring opportunity exists in a predetermined slot within a predetermined frame. Here, the predetermined slot may be a slot within the determined SCS frame. Therefore, the control unit 120 may determine the slot (or frame) in which the PDCCH monitoring opportunity exists based on the determined SCS.

[0087] The control unit 120 may determine an opportunity for PDCCH monitoring on an active downlink BWP based on the PDCCH monitoring period, the PDCCH monitoring offset, and the PDCCH monitoring pattern within the determined slot.

[0088] Step S143: The control unit 120 may determine the RAR window. The control unit 120 may determine the RAR window based on the determined SCS and / or the determined PDCCH monitoring opportunities.

[0089] The control unit 120 may determine the starting position of the RAR window, and the control unit 120 may determine the starting position to be the first symbol of the earliest CORESET set in UE 100 to receive a PDCCH (e.g., a PDCCH for a Type 1-PDCCH CSS set). The first symbol may be at least one symbol after the last symbol of the last PRACH opportunity corresponding to the PRACH transmission. The symbol duration may correspond to the determined SCS. The symbol duration may correspond to the SCS for a PDCCH for a Type 1-PDCCH CSS set, for example.

[0090] Here, the PRACH transmission may be the transmission of MSG1 as described above. The control unit 120 of UE100 may determine the starting position of the PAR window by assuming that UE100 has transmitted a PRACH even if it has not.

[0091] The control unit 120 may determine the length of the RAR window. The control unit 120 may determine the length of the RAR window based on the determined SCS. The control unit 120 may determine the length of the RAR window based on information indicating the number of slots based on the SCS of the PDCCH for a Type 1-PDCCH CSS set (e.g., ra-ResponseWindow). The length of the RAR window may be indicated by the number of slots. The RAR window may be referred to as the MSG2 window. This information may be included in the SIB1 request setting information.

[0092] Step S144: The control unit 120 may determine RA-RNTI. The control unit 120 may determine RA-RNTI by at least one of the following methods.

[0093] Firstly, the control unit 120 may determine RA-RNTI based on the determined SCS. The control unit 120 may calculate RA-RNTI using, for example, the following formula.

[0094] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id s_id is the index of the first OFDM symbol of the PRACH opportunity. The range of s_id is 0 or greater and less than 14 (0 ≤ s_id < 14). t_id is the index of the first slot of the PRACH opportunity within one system frame. The range of t_id is 0 or greater and less than 80 (0 ≤ t_id < 80). f_id is the index of the PRACH opportunity in the frequency domain. The range of f_id is 0 or greater and less than 8 (0 ≤ f_id < 8). ul_carrier_id is the uplink carrier used for RA preamble transmission. If the uplink carrier is a normal uplink (NUL) carrier, ul_carrier_id is 0. If the uplink carrier is a supplementary uplink (SUL) carrier, ul_carrier_id is 1.

[0095] The control unit 120 may determine t_id based on a PRACH opportunity (i.e., a PRACH transmission opportunity). Therefore, the control unit 120 may determine t_id based on the SCS. The control unit 120 can determine RA-RNTI based on SCS-related information. The control unit 120 may calculate RA-RNTI based on the determined t_id. The control unit 120 determines the calculated RA-RNTI as the RA-RNTI for MSG2 reception.

[0096] Secondly, the control unit 120 determines RA-RNTI based on information indicating RA-RNTI. The SIB1 request setting information may include information indicating RA-RNTI. The control unit 120 may determine RA-RNTI as a value indicated by information indicating RA-RNTI, for example.

[0097] The information indicating RA-RNTI may be information indicating a common RA-RNTI used in common by each UE100 (hereinafter referred to as common RA-RNTI information). The common RA-RNTI information may indicate a common RA-RNTI value. Furthermore, the common RA-RNTI may be a fixed value, for example, specified in the technical specifications. That is, the information (value) indicating RA-RNTI may be a predefined value, or it may be information (value) known to the base station 200 and UE100. The common RA-RNTI information may indicate that the use of the common RA-RNTI is permitted.

[0098] As shown in step S301 of Figure 8, the control unit 120 may determine whether the SIB1 request setting information includes common RA-RNTI information. If the SIB1 request setting information includes common RA-RNTI information, the control unit 120 may execute step S302. On the other hand, if the SIB1 request setting information does not include common RA-RNTI information, the control unit 120 may execute step S303.

[0099] In step S302, the control unit 120 may use a common RA-RNTI. Therefore, the control unit 120 may determine the common RA-RNTI as the RA-RNTI based on the common RA-RNTI information.

[0100] In step S303, the control unit 120 may use the normal RA-RNTI. Therefore, the control unit 120 may use the RA-RNTI (normal RA-RNTI) calculated using the above formula.

[0101] Thus, if the SIB1 request setting information includes common RA-RNTI information, the control unit 120 may determine the common RA-RNTI as the RA-RNTI. On the other hand, if the SIB1 request setting information does not include common RA-RNTI information, the control unit 120 may determine the RA-RNTI information based on the SCS-related information.

[0102] Information indicating RA-RNTI (e.g., common RA-RNTI information) may be set for one or more cells (so-called NES cells) that support on-demand SIB1. Therefore, information indicating RA-RNTI may be associated with information corresponding to each NES cell. Information indicating RA-RNTI may indicate the RA-RNTI used in the associated cell. Common RA-RNTI information may have different values ​​for each cell. Common RA-RNTI information may have the same value for each cell.

[0103] Furthermore, information indicating RA-RNTI (for example, common RA-RNTI information) is set for one or more frequencies. Therefore, the information indicating RA-RNTI may be associated with information corresponding to each frequency. The information indicating RA-RNTI may indicate the RA-RNTI used at the associated frequency.

[0104] As described above, the control unit 120 of UE100 may determine the parameters for receiving MSG2. The control unit 120 may use the determined parameters to control the reception of MSG2.

[0105] Step S150: The transmitter 211 of the base station 202 transmits the physical downlink control channel (PDCCH) from cell C2 to UE100. The receiver 112 of UE100 receives the PDCCH from cell C2.

[0106] The PDCCH is accompanied by cyclic redundancy check (CRC) scrambled by RA-RNTI. The PDCCH carries scheduling information (also called a downlink assignment) indicating the wireless resource allocation of message 2. That is, for example, the resources of the PDSCH may be scheduled using a PDCCH with a CRC scrambled by RA-RNTI. Here, MSG2 may include a PDCCH with a CRC scrambled by RA-RNTI, and the PDSCH scheduled by said PDCCH. MSG2 may also be called a random access response.

[0107] The control unit 120 of UE100 monitors the PDCCH with scrambled CRC by RA-RNTI in cell C2. The control unit 120 may monitor the PDCCH based on a determined PDCCH monitoring opportunity and / or RAR window. If the control unit 120 successfully detects (decodes) (i.e., receives) the PDCCH, it may attempt to receive the MSG2 (PDSCH) based on the scheduling information carried by the PDCCH. For example, the control unit 120 of UE100 may monitor the PDCCH with scrambled CRC by RA-RNTI within a determined RAR window and at a determined PDCCH monitoring opportunity.

[0108] Step S160: The transmitter 211 of the base station 202 transmits MSG2 from cell C2 to UE100. The receiver 112 of UE100 receives MSG2 from cell C2. MSG2 may be an acknowledgment message for MSG1.

[0109] The receiving unit 112 of UE100 may receive MSG2 based on downlink resource information. The receiving unit 112 may receive MSG2 in a downlink BWP based on downlink resource information, for example. That is, the control unit 120 of UE100 may receive a random access response based on downlink resource information. For example, the control unit 120 of UE100 may monitor a PDCCH with a CRC scrambled by RA-RNTI in a type 1 PDCCH CSS of a downlink BWP.

[0110] When the control unit 120 of UE100 receives MSG2, it may determine whether or not it contains specific information. The specific information may be, for example, a MAC subPDU containing a random access preamble identifier (RAPID) corresponding to the random access preamble (i.e., the index of the random access preamble) transmitted in the on-demand SIB1 request.

[0111] The control unit 120 may consider the reception of MSG2 to have been successful if MSG2 contains specific information. On the other hand, the control unit 120 may consider the reception of MSG2 to have been unsuccessful if MSG2 does not contain specific information. In other words, the control unit 120 may consider the reception of MSG2 to have been successfully completed if MSG2 (i.e., the random access response) contains a MAC subPDU that includes a RAPID corresponding to the transmitted random access preamble (i.e., the index of the random access preamble). Furthermore, if the control unit 120 considers the reception of MSG2 to have been successfully completed, the control unit 120 may consider the random access procedure to have been successfully completed if MSG2 (i.e., the random access response) contains a MAC subPDU that includes only the RAPID. In other words, the control unit 120 (for example, the MAC layer) may notify the RRC layer that it has received an acknowledgment message for the SIB1 request (MSG1). Alternatively, the control unit 120 (for example, the MAC layer) may notify the PHY layer that it has received an acknowledgment message for the SIB1 request (MSG1).

[0112] Step S170: The transmitter 211 of the base station 202 transmits PDCCH from cell C2 to UE100. The receiver 112 of UE100 receives PDCCH from cell C2.

[0113] The PDCCH is accompanied by a cyclic redundancy check (CRC) scrambled by a System Information Radio Network Temporary Identifier (SI-RNTI). The PDCCH carries scheduling information indicating the radio resource allocation of the SI message.

[0114] The control unit 120 of UE100 monitors the PDCCH with CRC scrambled by SI-RNTI. For example, the control unit 120 of UE100 (e.g., the PHY layer) may start monitoring the PDCCH with CRC scrambled by SI-RNTI based on notification of receipt of an acknowledgment message for an SIB1 request (MSG1) from the MAC layer. The control unit 120 may determine the control resource set #0 (CORESET #0) and search space #0 (SS #0) where downlink control information (DCI) dedicated to SIB1 resides, based on the SSB (specifically, MIB) of cell C2. That is, the control unit 120 may determine CORESET #0 and / or search space #0 for the PDCCH with CRC scrambled by SI-RNTI based on the information contained in the MIB. The control unit 120 may monitor the PDCCH based on the determined control resource set #0 and search space #0. The control unit 120 may also determine the control resource set #0 (CORESET #0) and search space #0 (SS #0) where SIB1-dedicated downlink control information (DCI) resides, based on the SIB1 request setting information. That is, the control unit 120 may determine CORESET #0 and / or search space #0 for the PDCCH with CRC scrambled by SI-RNTI, based on the information included in the SIB1 request setting information. The control unit 120 may monitor the PDCCH based on the determined control resource set #0 and search space #0.

[0115] If the control unit 120 successfully decodes the PDCCH with the CRC scrambled by SI-RNTI, it may attempt to receive the SI message (SIB1) based on the scheduling information carried by the PDCCH.

[0116] Here, the control unit 120 of UE100 may monitor the PDCCH with the CRC scrambled by P-RNTI. For example, the control unit 120 of UE100 (e.g., the PHY layer) may start monitoring the PDCCH with the CRC scrambled by P-RNTI based on notification of receipt of an acknowledgment message for an SIB1 request (MSG1) from the MAC layer. If the control unit 120 successfully decodes the PDCCH with the CRC scrambled by P-RNTI, it may receive notification of an update to a system information message based on a short message.

[0117] Step S205: The transmitting unit 211 of the base station 202 transmits an SI message including the on-demand SIB1 from cell C2 to UE100. The receiving unit 112 of UE100 receives the SI message including the on-demand SIB1 from cell C2. As a result, the receiving unit 112 receives the on-demand SIB1. UE100 can acquire the on-demand SIB1. Note that the SIB1 (SI message) may be carried by a physical downlink sharing channel (PDSCH).

[0118] As described above, the receiving unit 112 of UE 100 may receive SIB1 request setting information for acquiring on-demand SIB1 from cell C1. The control unit 120 may control the reception of MSG2, which is a response to MSG1 for requesting on-demand SIB1. The control unit 120 may control the reception of MSG2 based on SCS-related information contained in at least one of the SIB1 request setting information and the MIB from cell C2. Therefore, the SIB1 request setting information may be used to determine the RA-RNTI for receiving MSG2. This allows the control unit 120 to grasp the SCS based on the SCS-related information and to appropriately receive MSG2. The operation for receiving MSG2 for acquiring on-demand SIB1 becomes clear, and UE 100 can appropriately acquire on-demand SIB1.

[0119] Furthermore, the control unit 120 may determine the SCS based on SCS-related information. Based on the determined SCS, the control unit 120 may determine at least one of the RAR window and PDCCH monitoring opportunity for receiving MSG2. This allows the control unit 120 to determine the SCS based on SCS-related information and determine the RAR window and PDCCH monitoring opportunity for receiving MSG2, thereby enabling appropriate reception of MSG2.

[0120] Furthermore, the control unit 120 may determine the SCS based on the on-demand SIB1 obtained based on the SIB1 request setting information, without using the SCS determined in addition to acquiring the on-demand SIB1. This allows for conventional operation except for acquiring the on-demand SIB1, and reduces the impact on the mobile communication system.

[0121] Furthermore, if the SIB1 request setting information includes SCS-related information, the control unit 120 may determine the SCS based on the SCS-related information included in the SIB1 request setting information. If the SIB1 request setting information does not include SCS-related information, the control unit 120 may determine the SCS based on the SCS-related information included in the MIB. This allows the UE 100 to start the operation to acquire on-demand SIB1 based on the SIB1 request setting information before receiving the MIB of cell C2. This makes it possible for the UE 100 to speed up the acquisition of on-demand SIB1.

[0122] Furthermore, the SCS-related information included in the SIB1 request setting information and the SCS-related information included in the MIB may indicate the same SCS. This allows the UE100 to determine the SCS even if it receives only one of either the SIB1 request setting information or the MIB.

[0123] Furthermore, SCS-related information may be configured for one or more downlink BWPs. This allows for SCS configuration for each downlink BWP, enabling flexible control over the acquisition of on-demand SIB1.

[0124] Furthermore, the receiving unit 112 of UE100 may receive SIB1 request setting information for acquiring on-demand SIB1 from cell C1. The control unit 120 may control the reception of MSG2, which is a response to MSG1 for requesting on-demand SIB1. The control unit 120 may control the reception of MSG2 based on RA-RNTI determined based on the SIB1 request setting information. This clarifies the operation for receiving MSG2 to acquire on-demand SIB1, enabling UE100 to acquire on-demand SIB1 appropriately.

[0125] Furthermore, the SIB1 request setting information may include SCS-related information. The control unit 120 may determine RA-RNTI based on the SCS-related information. The control unit 120 can determine the SCS based on the SCS-related information and determine RA-RNTI for receiving MSG2, thereby enabling proper reception of MSG2.

[0126] Furthermore, the control unit 120 may determine the RA-RNTI based on the on-demand SIB1 obtained based on the SIB1 request setting information, without using the RA-RNTI determined for purposes other than acquiring the on-demand SIB1. This allows for conventional operation except for acquiring the on-demand SIB1, thereby reducing the impact on the mobile communication system.

[0127] Furthermore, if the SIB1 request setting information includes information indicating a common RA-RNTI used in common by each UE 100, the control unit 120 may determine the common RA-RNTI as the RA-RNTI. This allows UE 100 to receive on-demand SIB1 without sending its own request by using the common RA-RNTI shared with the other UE 100 when another UE 100 is sending an on-demand SIB1 request.

[0128] Furthermore, the SIB1 request setting information may include SCS-related information. If the SIB1 request setting information does not include information indicating a common RA-RNTI, the control unit 120 may determine the RA-RNTI based on the SCS-related information. As a result, even in cells where a common RA-RNTI is not set, the UE 100 can determine the RA-RNTI for receiving MSG2 and receive MSG2 appropriately.

[0129] Furthermore, information indicating a common RA-RNTI is set for one or more cells that support on-demand SIB1. This allows UE100s attempting to obtain on-demand SIB1 from the same cell to use a common RA-RNTI, enabling them to receive on-demand SIB1 without sending an on-demand SIB1 request.

[0130] Furthermore, information indicating a common RA-RNTI may be set for one or more frequencies. This allows UE100s attempting to acquire on-demand SIB1 from cells at the same frequency to use a common RA-RNTI, and may be able to receive on-demand SIB1 without sending an on-demand SIB1 request.

[0131] (Other Embodiments) In the embodiments described above, a mobile communication system based on NR was used as an example for the mobile communication system 1. However, the mobile communication system 1 is not limited to this example. The mobile communication system 1 may be a system compliant with a TS of either LTE (Long Term Evolution) or another generation system of the 3GPP standard (e.g., 6th generation). The base station 200 may be an eNB that provides E-UTRA user plane and control plane protocol terminations directed to UE100 in LTE. The mobile communication system 1 may be a system compliant with a TS of a standard other than the 3GPP standard. The base station 200 may be an IAB (Integrated Access and Backhaul) donor or IAB node. The base station 200 may be functionally divided into a CU (Central Unit) and a DU (Distributed Unit).

[0132] A program may be provided that causes a computer to execute each process performed by the UE 100 or base station 200. The program may be recorded on a computer-readable medium. Using a computer-readable medium, it is possible to install the program on a computer. Here, the computer-readable medium on which the program is recorded may be a non-transient recording medium. The non-transient recording medium is not particularly limited, but may be a recording medium such as a CD-ROM (Compact Disk Read Only Memory) or a DVD-ROM (Digital Versatile Disc Read Only Memory). Alternatively, the circuits that execute each process performed by the UE 100 or base station 200 may be integrated, and at least a part of the UE 100 or base station 200 may be configured as a semiconductor integrated circuit (chipset, SoC (System On Chip)).

[0133] In the embodiments described above, "transmit" may mean processing at least one layer in the protocol stack used for transmission, or it may mean physically transmitting a signal wirelessly or via a wire. Alternatively, "transmit" may mean a combination of processing at least one layer and physically transmitting a signal wirelessly or via a wire. Similarly, "receive" may mean processing at least one layer in the protocol stack used for reception, or it may mean physically receiving a signal wirelessly or via a wire. Alternatively, "receive" may mean a combination of processing at least one layer and physically receiving a signal wirelessly or via a wire. Similarly, "obtain / acquire" may mean obtaining information from stored information, obtaining information from information received from another node, or obtaining information by generating it. Similarly, the phrases “based on” and “depending on / in response to” do not mean “based solely on” or “in response to” unless otherwise specified. The phrase “based on” means both “based solely on” and “at least partially on.” Similarly, the phrase “in response” means both “at least partially on” and “in at least partially on.” Similarly, “include” and “comprise” do not mean “include only the listed items,” but rather “may include only the listed items,” or “may include additional items in addition to the listed items.” Similarly, in this disclosure, “or” does not mean exclusive OR, but rather logical OR. Furthermore, any reference to elements using designations such as “first,” “second,” etc., as used in this disclosure does not limit the quantity or order of those elements in general. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements.Therefore, references to the first and second elements do not imply that only two elements may be adopted therein, or that the first element must precede the second element in any way. In this disclosure, where articles are added by translation, such as a, an, and the in English, these articles shall be plural unless it is clearly indicated from the context that they are not.

[0134] This disclosure is described in accordance with the embodiments, but it is understood that this disclosure is not limited to such embodiments or structures. This disclosure also includes various modifications and variations within the equivalence. In addition, various combinations and forms, as well as other combinations and forms that include only one, more, or fewer of those elements, fall within the scope and concept of this disclosure.

[0135] (Note) The features of the above-described embodiment are noted below.

[0136] (Note 1) A communication device comprising: a receiving unit (112) that receives system information from a first cell, including information regarding settings for acquiring an on-demand system information block type 1 (SIB1); and a control unit (120), wherein the information regarding settings for acquiring the on-demand SIB1 includes information for setting a random access response (RAR) window; and the control unit determines a RAR window for receiving a random access response corresponding to a request for the on-demand SIB1 based on the information for setting the RAR window and information indicating the subcarrier interval (SCS) indicated by the master information block (MIB) included in the SS / PBCH block received from the second cell.

[0137] (Note 2) The information relating to the settings for acquiring the on-demand SIB1 includes a cell identifier corresponding to one or more of the second cells, and the information relating to setting the RAR window is the communication device described in Note 1, corresponding to each of the cell identifiers corresponding to one or more of the second cells.

[0138] (Note 3) The communication device according to Note 1 or 2, wherein the information relating to the settings for obtaining the on-demand SIB1 includes information relating to the SS / PBCH block of the second cell, and the control unit selects a random access opportunity to request the on-demand SIB1 to the second cell based on the information relating to the SS / PBCH block of the second cell.

[0139] (Note 4) The communication device according to any one of Notes 1 to 3, wherein the control unit monitors a PDCCH with cyclic redundancy check (CRC) scrambled by a System Information Radio Network Temporary Identifier (SI-RNTI) based on the reception of the random access response in the RAR window.

[0140] (Note 5) The base station includes a transmitting unit (211) that transmits system information, including information regarding settings for acquiring an on-demand system information block type 1 (SIB1), to a communication device in the first cell, wherein the information regarding settings for acquiring the on-demand SIB1 includes information for setting a random access response (RAR) window, and the information for setting the RAR window, together with information indicating the subcarrier interval (SCS) indicated by the master information block (MIB) included in the SS / PBCH block received from the second cell, is used in the communication device to determine a RAR window for receiving a random access response corresponding to a request for the on-demand SIB1.

[0141] (Note 6) The information relating to the settings for acquiring the on-demand SIB1 includes a cell identifier corresponding to one or more of the second cells, and the information relating to setting the RAR window is the base station described in Note 5 corresponding to each of the cell identifiers corresponding to one or more of the second cells.

[0142] (Note 7) The base station as described in Note 5 or 6, wherein the information relating to the settings for obtaining the on-demand SIB1 includes information relating to the SS / PBCH block of the second cell, and the information relating to the SS / PBCH block of the second cell is used in the communication device to select a random access opportunity used to request the on-demand SIB1 to the second cell.

[0143] (Note 8) A communication method performed by a communication device (100), comprising: receiving system information from a first cell, which includes information regarding settings for acquiring an on-demand system information block type 1 (SIB1); and determining a RAR window for receiving a random access response corresponding to a request for the on-demand SIB1, based on information for setting a random access response (RAR) window included in the information regarding settings for acquiring the on-demand SIB1, and information indicating a subcarrier interval (SCS) indicated by a master information block (MIB) included in an SS / PBCH block received from a second cell.

[0144] (Note 9) The information relating to the settings for acquiring the on-demand SIB1 includes a cell identifier corresponding to one or more of the second cells, and the information relating to setting the RAR window is the communication method described in Note 8 corresponding to each of the cell identifiers corresponding to one or more of the second cells.

[0145] (Note 10) The communication method according to Note 8 or 9, wherein the information relating to the settings for obtaining the on-demand SIB1 includes information relating to the SS / PBCH block of the second cell, and the communication method further comprises the step of selecting a random access opportunity to be used for requesting the on-demand SIB1 to the second cell based on the information relating to the SS / PBCH block of the second cell.

[0146] (Note 11) A communication method according to any one of Notes 8 to 10, which monitors a PDCCH with cyclic redundancy checks (CRC) scrambled by a System Information Radio Network Temporary Identifier (SI-RNTI) based on the reception of the random access response in the RAR window.

[0147] (Note 12) A communication method performed at a base station (200), comprising the step of transmitting system information, including information regarding settings for acquiring an on-demand system information block type 1 (SIB1), to a communication device in a first cell, wherein the information regarding settings for acquiring the on-demand SIB1 includes information for setting a random access response (RAR) window, and the information for setting the RAR window, together with information indicating the subcarrier interval (SCS) indicated by a master information block (MIB) included in an SS / PBCH block received from a second cell, is used in the communication device to determine a RAR window for receiving a random access response corresponding to a request for the on-demand SIB1.

[0148] (Note 13) The information relating to the settings for acquiring the on-demand SIB1 includes a cell identifier corresponding to one or more of the second cells, and the information relating to setting the RAR window is the communication method described in Note 12, corresponding to each of the cell identifiers corresponding to one or more of the second cells.

[0149] (Note 14) The information relating to the settings for obtaining the on-demand SIB1 includes information relating to the SS / PBCH block of the second cell, and the information relating to the SS / PBCH block of the second cell is the communication method described in Note 12 or 13 used in the communication device to select a random access opportunity to be used for requesting the on-demand SIB1 to the second cell.

[0150] (Note 15) A communication device comprising: a receiving unit that receives setting information for acquiring an on-demand SIB1, which is a system information block type 1 of a second cell transmitted from a first cell in response to a request; and a control unit that controls the reception of a second message (MSG2) which is a response to a first message (MSG1) for requesting the on-demand SIB1, wherein the control unit controls the reception of the MSG2 based on the setting information and information regarding the subcarrier interval (SCS) included in at least one of the master information blocks (MIBs) from the second cell.

[0151] (Note 16) The communication device according to Note 15, wherein the control unit determines the SCS based on information relating to the SCS, and the control unit determines at least one of a random access response (RAR) window and a physical downlink control channel (PDCCH) monitoring opportunity for receiving the MSG2 based on the determined SCS.

[0152] (Note 17) The communication device according to Note 15 or 16, wherein the control unit determines the SCS based on the on-demand SIB1 acquired based on the setting information, without using the determined SCS other than acquiring the on-demand SIB1.

[0153] (Note 18) The communication device according to any one of Notes 15 to 17, wherein the control unit determines the SCS based on the information about the SCS included in the setting information if the setting information includes information about the SCS, and determines the SCS based on the information about the SCS included in the MIB if the setting information does not include information about the SCS.

[0154] (Note 19) A communication device according to any one of Notes 15 to 18, wherein the information relating to the SCS included in the setting information and the information relating to the SCS included in the MIB indicate the same SCS.

[0155] (Note 20) The communication device described in any one of Notes 15 to 19, which is set for each of the one or more downlink bandwidth portions (BWPs) of the SCS.

[0156] (Note 21) A base station comprising a transmitting unit that transmits to a communication device configuration information for obtaining an on-demand SIB1, which is a system information block type 1 of a second cell transmitted from a first cell upon request, wherein the configuration information includes information regarding the subcarrier interval (SCS) for controlling the reception of a second message (MSG2), which is a response to a first message (MSG1) for requesting the on-demand SIB1.

[0157] (Note 22) A communication method performed by a communication device, comprising: receiving configuration information from a first cell for obtaining an on-demand SIB1, which is a system information block type 1 of a second cell transmitted in response to a request; controlling the reception of a second message (MSG2), which is a response to a first message (MSG1) for a request for the on-demand SIB1; and controlling the reception of the MSG2 based on the configuration information and information regarding the subcarrier interval (SCS) included in at least one of the master information blocks (MIBs) from the second cell.

Claims

A receiving unit (112) receives system information from the first cell, which includes information regarding the settings for acquiring on-demand system information block type 1 (SIB1), The system comprises a control unit (120) and The information regarding the settings for obtaining the aforementioned on-demand SIB1 includes information for setting the Random Access Response (RAR) window, The control unit determines a RAR window for receiving a random access response corresponding to a request from the on-demand SIB1, based on information for setting the RAR window and information indicating the subcarrier interval (SCS) indicated by the master information block (MIB) contained in the SS / PBCH block received from the second cell. Communication device. 　 The information regarding the settings for obtaining the on-demand SIB1 includes a cell identifier corresponding to one or more of the second cells, The information for setting the RAR window corresponds to each of the cell identifiers corresponding to one or more of the second cells. The communication device according to claim 1. 　 The information regarding the settings for obtaining the on-demand SIB1 includes information regarding the SS / PBCH block of the second cell, The control unit selects random access opportunities to be used for requesting on-demand SIB1 to the second cell based on information regarding the SS / PBCH block of the second cell. The communication device according to claim 1 or 2. 　 The control unit monitors the PDCCH with cyclic redundancy checks (CRC) scrambled by a System Information Radio Network Temporary Identifier (SI-RNTI) based on the reception of the random access response in the RAR window. 　 The communication device according to claim 1 or 2. 　 The system includes a transmitting unit (211) that transmits system information, including information regarding settings for acquiring an on-demand system information block type 1 (SIB1), to a communication device in the first cell. The information regarding the settings for obtaining the aforementioned on-demand SIB1 includes information for setting the Random Access Response (RAR) window, The information for setting the RAR window, along with information indicating the subcarrier interval (SCS) as shown by the master information block (MIB) contained in the SS / PBCH block received from the second cell, is used in the communication device to determine the RAR window for receiving a random access response corresponding to the request of the on-demand SIB1. Base station. 　 The information regarding the settings for obtaining the on-demand SIB1 includes a cell identifier corresponding to one or more of the second cells, The information for setting the RAR window corresponds to each of the cell identifiers corresponding to one or more of the second cells. The base station according to claim 5. 　 The information regarding the settings for obtaining the on-demand SIB1 includes information regarding the SS / PBCH block of the second cell, Information regarding the SS / PBCH block of the second cell is used in the communication device to select random access opportunities used for on-demand SIB1 requests to the second cell. The base station according to claim 5 or 6. 　 A communication method performed by a communication device (100), The steps include receiving system information from the first cell, which includes information regarding the settings for obtaining an on-demand system information block type 1 (SIB1), The step of determining a random access response for receiving a request for the on-demand SIB1, based on information for setting a random access response (RAR) window included in the information for setting the on-demand SIB1, and information indicating the subcarrier interval (SCS) indicated by the master information block (MIB) included in the SS / PBCH block received from the second cell. Communication method. 　 The information regarding the settings for obtaining the on-demand SIB1 includes a cell identifier corresponding to one or more of the second cells, The information for setting the RAR window corresponds to each of the cell identifiers corresponding to one or more of the second cells. The communication method according to claim 8. 　 The information regarding the settings for obtaining the on-demand SIB1 includes information regarding the SS / PBCH block of the second cell, The communication method further comprises the step of selecting a random access opportunity to be used for requesting an on-demand SIB1 to the second cell based on information regarding the SS / PBCH block of the second cell. The communication method according to claim 8 or 9. 　 Based on the reception of the Random Access Response in the RAR window, the PDCCH is monitored with cyclic redundancy checks (CRC) scrambled by the System Information Radio Network Temporary Identifier (SI-RNTI). The communication method according to claim 8 or 9. 　 A communication method performed at a base station (200), The system includes a step of transmitting system information, including information regarding settings for acquiring an on-demand system information block type 1 (SIB1), to a communication device in the first cell. The information regarding the settings for obtaining the aforementioned on-demand SIB1 includes information for setting the Random Access Response (RAR) window, The information for setting the RAR window, along with information indicating the subcarrier interval (SCS) as shown by the master information block (MIB) contained in the SS / PBCH block received from the second cell, is used in the communication device to determine the RAR window for receiving a random access response corresponding to the request of the on-demand SIB1. Communication method. 　 The information regarding the settings for obtaining the on-demand SIB1 includes a cell identifier corresponding to one or more of the second cells, The information for setting the RAR window corresponds to each of the cell identifiers corresponding to one or more of the second cells. The communication method according to claim 12. 　 The information regarding the settings for obtaining the on-demand SIB1 includes information regarding the SS / PBCH block of the second cell, Information regarding the SS / PBCH block of the second cell is used in the communication device to select random access opportunities used for on-demand SIB1 requests to the second cell. The communication method according to claim 12 or 13.

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