WO2023127634A1 - Communication device, base station, and communication method - Google Patents

Abstract

A communication device (100) which carries out radio communication in bandwidth portions constituting a portion of the total bandwidth of a cell of a base station (200) comprises: a control unit (120) that carries out a BWP timer-based switching process in which the bandwidth portions are switched on the basis of a BWP switching timer expiration for switching the bandwidth portions, and a physical downlink control channel (PDCCH) monitoring state relating to monitoring of the PDCCH is switched; and a reception unit (112) that receives radio resource control (RRC) messages that include switching control information for controlling the BWP timer-based switching process. The control unit (120) controls the BWP timer-based switching process on the basis of the switching control information.

Description

Communication device, base station, and communication method Cross-references to related applications

This application is based on and claims the benefit of priority from patent application number 2021-214683, filed December 28, 2021, the entire contents of which are incorporated by reference. incorporated herein by.

The present disclosure relates to communication devices, base stations, and communication methods used in mobile communication systems.

In recent years, in the 3GPP (registered trademark; hereinafter the same) (3rd Generation Partnership Project), which is a standardization project for mobile communication systems, power to reduce the power consumption of communication devices in a radio resource control (RRC) connected state The introduction of saving techniques into fifth generation (5G) systems is under consideration.

For example, as one of the power saving techniques, in order to reduce the power consumption required for monitoring a physical downlink control channel (PDCCH) in a communication device, PDCCH monitoring related to monitoring the physical downlink control channel A process of switching states (hereinafter referred to as switching process) is under consideration. For example, the communication device switches the PDCCH monitoring state to a state in which the PDCCH monitoring cycle is lengthened or PDCCH monitoring is skipped (hereinafter referred to as a PDCCH monitoring skipping state). In particular, in a communication device, by dynamically switching the PDCCH monitoring state during the active time in discontinuous reception (DRX) in the RRC connected state, a greater power consumption reduction effect than the power consumption reduction by DRX can be achieved. Obtainable. Such an operation of skipping PDCCH monitoring and an operation of switching PDCCH monitoring states may be referred to as PDCCH monitoring adaptation.

Here, assume a case where a communication device that performs wireless communication in a predetermined bandwidth part (BWP), which is part of the total bandwidth of a cell of a base station, is in a PDCCH monitoring skipping state. The communication device switches the PDCCH monitoring state, specifically, PDCCH monitoring, triggered by the switching of the predetermined BWP based on the expiration of the BWP switching timer due to no data communication occurring in the predetermined BWP for a certain period of time. A method of doing so has been proposed. (See Non-Patent Document 1).

A communication device according to the first aspect is a communication device that performs wireless communication in a bandwidth portion that is a portion of the total bandwidth of a cell of a base station. The communication device switches the bandwidth portion based on expiration of a BWP switching timer for switching the bandwidth portion, and switches a PDCCH monitoring state regarding monitoring of a physical downlink control channel (PDCCH). A control unit that performs processing, and a reception unit that receives a radio resource control (RRC) message including switching control information for controlling the BWP timer-based switching processing. The control unit controls the switching process caused by the BWP timer based on the switching control information.

A communication device according to the second aspect is a communication device that performs wireless communication in a bandwidth portion that is a portion of the total bandwidth of a cell of a base station. The communication device controls a switching process for switching a PDCCH monitoring state related to monitoring of a physical downlink control channel (PDCCH) in a predetermined bandwidth portion among one or more bandwidth portions set in the communication device. and a receiver for receiving a radio resource control (RRC) message including switching control information for controlling the switching process. The control unit performs the switching process in the predetermined bandwidth portion using switching settings for the predetermined bandwidth portion based on the switching control information when the predetermined bandwidth portion is activated. and suspends the switching setting when the predetermined bandwidth portion is deactivated.

A base station according to a third aspect is the base station that performs wireless communication with a communication device in a bandwidth portion that is a portion of the total bandwidth of a cell of the base station. The base station includes a control unit that generates a radio resource control (RRC) message including switching control information for controlling BWP timer-based switching processing in the communication device, and a transmission unit that transmits the RRC message to the communication device. And prepare. In the BWP timer-triggered switching process, the communication device switches the bandwidth portion based on expiration of a BWP switching timer for switching the bandwidth portion, and a PDCCH for monitoring a physical downlink control channel (PDCCH). Switch the monitoring state.

A communication method according to a fourth aspect is a communication method performed by a communication device that performs wireless communication in a bandwidth portion that is a portion of the total bandwidth of a cell of a base station. The communication method switches the bandwidth portion based on expiration of a BWP switching timer for switching the bandwidth portion, and switches a PDCCH monitoring state for monitoring a physical downlink control channel (PDCCH). and receiving a radio resource control (RRC) message containing switching control information for controlling said BWP timer triggered switching process. In the step of performing the switching process caused by the BWP timer, the switching process caused by the BWP timer is controlled based on the switching control information.

A communication method according to a fifth aspect is a communication method performed by a communication device that performs wireless communication in a bandwidth portion that is a portion of the total bandwidth of a cell of a base station. In the communication method, in a predetermined bandwidth portion among one or more bandwidth portions set in the communication device, a step of controlling a switching process for switching a PDCCH monitoring state regarding monitoring of a physical downlink control channel (PDCCH). and receiving a radio resource control (RRC) message containing switching control information for controlling the switching process. In the step of controlling the switching process, if the predetermined bandwidth portion is activated, using a switching setting for the predetermined bandwidth portion based on the switching control information, The method further comprises controlling the switching process and suspending the switching setting when the predetermined bandwidth portion is deactivated.

Objects, features, advantages, etc. of the present disclosure will become clearer from the following detailed description with reference to the accompanying drawings.
FIG. 1 is a diagram showing the configuration of a mobile communication system according to an embodiment. FIG. 2 is a diagram illustrating a configuration example of a protocol stack according to the embodiment; FIG. 3 is a sequence diagram showing an overview of radio communication operations in the mobile communication system according to the embodiment. FIG. 4 is a diagram showing an overview of PDCCH skipping according to the embodiment. FIG. 5 is a diagram showing an overview of search space set (SSSG) switching according to the embodiment. FIG. 6 is a diagram illustrating DRX and power saving states according to an embodiment. FIG. 7 is a sequence diagram illustrating an example of SSSG switching according to the embodiment. FIG. 8 is a diagram illustrating an example of timer-based SSSG switching according to an embodiment. FIG. 9 is a sequence diagram showing an overview of BWP switching based on expiration of the BWP switching timer according to the embodiment. FIG. 10 is a diagram showing the configuration of a UE according to the embodiment. FIG. 11 is a diagram showing the configuration of a base station according to the embodiment. FIG. 12 is a sequence diagram for explaining the first operation example of the mobile communication system according to the embodiment. FIG. 13 is a diagram for explaining a first operation example of the mobile communication system according to the embodiment. FIG. 14 is a sequence diagram for explaining a second operation example of the mobile communication system according to the embodiment. FIG. 15 is a diagram for explaining a second operation example of the mobile communication system according to the embodiment. FIG. 16 is a flowchart for explaining a third operation example of the mobile communication system according to the embodiment. 17 is a flowchart (part 1) for explaining a fourth operation example of the mobile communication system according to the embodiment; FIG. 18 is a flowchart (part 2) for explaining a fourth operation example of the mobile communication system according to the embodiment; FIG. FIG. 19 is a flowchart for explaining a fifth operation example of the mobile communication system according to the embodiment.

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

When the communication device switches the BWP based on the expiration of the BWP switching timer, there is a possibility that a discrepancy may occur between the actual PDCCH monitoring state in the communication device and the PDCCH monitoring state recognized by the base station. Therefore, there is a concern that the base station cannot properly perform radio communication with the communication device after the communication device switches the BWP based on the expiration of the BWP switching timer.

Therefore, the present disclosure enables appropriate wireless communication even when switching the BWP based on the expiration of the BWP switching timer in a mobile communication system in which the PDCCH monitoring state is switched based on the expiration of the BWP switching timer. One of the objects is to provide a communication device, a base station, and a communication method.

(1) Mobile communication system A mobile communication system according to this embodiment will be described.

First, the configuration of a mobile communication system 1 according to this embodiment will be described with reference to FIG. The mobile communication system 1 is, for example, a system conforming to the 3GPP Technical Specification (TS). In the following, as the mobile communication system 1, a mobile communication system based on the 3GPP standard 5th Generation System (5GS), that is, NR (New Radio) will be described as an example.

The mobile communication system 1 has a network 10 and user equipment (UE) 100 communicating 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.

The UE 100 is an example of a communication device. The UE 100 may be a mobile wireless communication device. UE 100 may be a device used by a user. The UE 100 may be a user equipment defined by 3GPP technical specifications. The UE 100 is, for example, a portable device such as a mobile phone terminal such as a smart phone, a tablet terminal, a notebook PC, a communication module, or a communication card. The UE 100 may be a vehicle (eg, car, train, etc.) or a device provided therein (eg, Vehicle UE). The UE 100 may be a transport body other than a vehicle (eg, a ship, an airplane, etc.) or a device provided thereon (eg, an Aerial UE). The UE 100 may be a sensor or a device attached thereto. Note that the UE 100 includes a mobile station, a mobile terminal, a mobile device, a mobile unit, a subscriber station, a subscriber terminal, a subscriber device, a subscriber unit, a wireless station, a wireless terminal, a wireless device, a wireless unit, a remote station, and a remote terminal. , remote device, or remote unit.

NG-RAN 20 includes multiple base stations 200 . Each base station 200 manages at least one cell. A cell constitutes the minimum unit of a communication area. One cell belongs to one frequency (carrier frequency) and is composed of one component carrier. The term “cell” may represent a radio communication resource and may also represent a communication target of UE 100 . Each base station 200 can perform radio communication with the UE 100 residing in its own cell. The base station 200 communicates with the UE 100 using the RAN protocol stack. Base station 200 provides NR user plane and control plane protocol termination towards UE 100 and is connected to 5GC 30 via NG interface. Such an NR base station 200 is sometimes referred to as a gNodeB (gNB).

The 5GC 30 includes a core network device 300. The core network device 300 includes, for example, AMF (Access and Mobility Management Function) and/or UPF (User Plane Function). AMF performs mobility management of UE100. UPF provides functions specialized for user plane processing. The AMF and UPF are connected with the base station 200 via the NG interface.

Next, a configuration example of a protocol stack according to this embodiment will be described with reference to FIG.

The protocol of the wireless section between the UE 100 and the base station 200 includes a physical (PHY) layer, a MAC (Medium Access Control) layer, an RLC (Radio Link Control) layer, a PDCP (Packet Data Convergence Protocol) layer, RRC layer.

The PHY layer performs encoding/decoding, modulation/demodulation, antenna mapping/demapping, and resource mapping/demapping. Data and control information are transmitted between the PHY layer of the UE 100 and the PHY layer of the base station 200 via physical channels.

The MAC layer performs data priority control, retransmission processing by hybrid ARQ (Hybrid Automatic Repeat Quest: HARQ), random access procedures, and the like. Data and control information are transmitted between the MAC layer of the UE 100 and the MAC layer of the base station 200 via transport channels. The MAC layer of base station 200 includes a scheduler. The scheduler determines uplink and downlink transport formats (transport block size, modulation and coding scheme (MCS)) and allocation resources to UE 100 .

The RLC layer uses the functions of the MAC layer and PHY layer to transmit data to the RLC layer on the receiving side. Data and control information are transmitted between the RLC layer of the UE 100 and the RLC layer of the base station 200 via logical channels.

The PDCP layer performs header compression/decompression and encryption/decryption.

An SDAP (Service Data Adaptation Protocol) layer may be provided as an upper layer of the PDCP layer. The SDAP (Service Data Adaptation Protocol) layer performs mapping between IP flows, which are the units in which the core network performs QoS control, and radio bearers, which are the units in which the AS (Access Stratum) performs QoS (Quality of Service) control.

The RRC layer controls logical channels, transport channels and physical channels according to radio bearer establishment, re-establishment and release. RRC signaling for various settings is transmitted between the RRC layer of UE 100 and the RRC layer of base station 200 . When there is an RRC connection between the RRC of UE 100 and the RRC of base station 200, UE 100 is in the RRC connected state. If there is no RRC connection between the RRC of the UE 100 and the RRC of the base station 200, the UE 100 is in RRC idle state. When the RRC connection between the RRC of UE 100 and the RRC of base station 200 is suspended, UE 100 is in RRC inactive state.

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 the UE 100 and the NAS layer of the core network device 300 (AMF). Note that the UE 100 has an application layer and the like in addition to the radio interface protocol.

(2) BWP (bandwidth part)
UE 100 and base station 200 communicate using BWP (Bandwidth Part), which is part of the total bandwidth of the cell. Specifically, the base station 200 configures one or more BWPs for the UE100. The base station 200 can notify the UE 100 of the BWP used for communication with the base station 200 (that is, the active BWP) among one or more set BWPs. Specifically, the base station 200 can transmit to the UE 100 an identifier indicating the BWP to be activated when executing the setting, that is, the BWP that is first used in communication with the base station 200 . In addition, for controlling switching from an active BWP to a BWP that is not an active BWP (hereinafter, inactive BWP) and switching from an inactive BWP to an active BWP (so-called BWP switching), for example, a physical downlink control channel (e.g., downlink link assignment, uplink grant), timers (ie bwp-InactivityTimer), RRC signaling, or MAC entities are used. Note that the higher layer signaling (RRC message) used for RRC signaling may be broadcasted system information or a dedicated RRC message transmitted to each UE.

BWP includes initial BWP and individual BWP. The initial BWP is used at least for initial access of the UE 100 . The initial BWP is commonly used by multiple UEs 100 . The initial BWP includes an initial BWP for downlink communication (hereinafter, initial downlink BWP (Initial DL BWP)) and an initial BWP for uplink communication (hereinafter, initial uplink BWP (Initial UL BWP)). The value of the identifier (ie, bwp-id) indicating each of the initial downlink BWP and the initial uplink BWP is 0.

For example, the UE 100 can determine the initial BWP (that is, the initial downlink BWP and the initial uplink BWP) using two methods. In the first method, the UE 100 determines the initial BWP based on CORESET#0, which is set using information contained in the master information block (MIB) within the physical broadcast channel (PBCH). In a second method, the UE 100 determines the initial BWP based on the location and bandwidth in the frequency domain configured using information contained in system information blocks (SIBs). UE 100 may apply the BWP determined by the first method to communication with base station 200, for example, until reception of message 4 in the random access procedure. For example, after receiving message 4, UE 100 may apply the BWP determined by the second method to communication with base station 200 .

The individual BWP is individually set for the UE 100. The dedicated BWP includes a dedicated BWP for downlink communication (hereinafter referred to as a dedicated downlink BWP (UE dedicated DL BWP)) and a dedicated BWP for uplink communication (hereinafter referred to as a dedicated uplink BWP (UE dedicated UL BWP)). The value of the identifier indicating each individual downlink BWP and individual uplink BWP is other than zero.

In the UE 100, for example, based on information (eg, information for downlink BWP (ie, BWP-Downlink) and information for uplink BWP (ie, BWP-Uplink)) included in the RRC message, individual BWP is set. For each of the information for downlink BWP and the information for individual uplink BWP, for example, information indicating the position and bandwidth in the frequency domain (eg, locationAndBadwidth), information indicating subcarrier spacing (eg, subcarrierSpacing), and At least one of information indicating whether to use an extended cyclic prefix (eg, cyclicPrefix) may be included.

In the following, the BWP for downlink communication may be referred to as downlink BWP (or DL BWP), and the BWP for uplink communication may be referred to as uplink BWP (or UL BWP).

Next, with reference to FIG. 3, an overview of wireless communication operations in the mobile communication system 1 according to this embodiment will be described.

The base station 200 configures the UE 100 with a search space corresponding to the candidate timing at which the PDCCH is provided. UE 100 in the RRC connected state monitors PDCCH in the set search space, receives downlink control information (Downlink Control Information: DCI) carried by PDCCH, and assigns resources (scheduling) indicated by DCI. According to the physical downlink shared channel (PDSCH) reception and / or physical uplink shared channel (PUSCH) is transmitted. For example, the UE 100 may monitor a set of PDCCH candidates according to the corresponding search space. That is, UE 100 may monitor a set of PDCCH candidates in a downlink BWP control resource set (CORESET) in a serving cell in which PDCCH monitoring is configured, according to the corresponding search space. Here, monitoring may refer to decoding each of the PDCCH candidates according to the monitored DCI format.

As shown in FIG. 3, in step S1, the base station 200 transmits an RRC message including PDCCH settings (PDCCH settings) to the UE 100, and performs various PDCCH settings for the UE 100. This RRC message is a UE-specific RRC message, and may be, for example, an RRC Reconfiguration message. Here, among the settings related to PDCCH, the search space settings include a search space period (also referred to as a PDCCH monitoring period), a search space offset (also referred to as a PDCCH monitoring offset), a search space duration (for example, the number of consecutive slots), and PDCCH monitoring. symbols for, aggregation level, search space type, DCI format, etc. Here, each search space (each set of search spaces) may be associated with one CORESET. Also, the search space setting may be set for each of one or more DL BWPs. Here, the search space type may include a UE-specific search space (USS) and/or a UE common search space (CSS).

DCI formats include scheduling DCI formats used for PDSCH or PUSCH scheduling and non-scheduling DCI formats not used for such scheduling. DCI transmitted in a scheduling DCI format is called scheduling DCI, and DCI transmitted in a non-scheduling DCI format is called non-scheduling DCI.

Scheduling DCI formats include a downlink DCI format used for PDSCH scheduling (eg, DCI format 1_0, DCI format 1_1, DCI format 1_2) and an uplink DCI format used for PUSCH scheduling (eg, DCI format 0_0, DCI format 0_1 and DCI format 0_2). The scheduling DCI may be UE-specific DCI that is sent for each UE. For example, the scheduling DCI may be transmitted by applying an RNTI (Radio Network Temporary Identifier) assigned to each UE. Here, the downlink DCI format used for PDSCH scheduling is also called downlink assignment. Also, the uplink DCI format used for PUSCH scheduling is also called an uplink grant.

On the other hand, non-scheduling DCI formats include, for example, DCI format 2_0 and DCI format 2_6. The non-scheduling DCI may be a DCI that can be transmitted to multiple UEs 100 at once. For example, non-scheduling DCI may be transmitted by applying a common RNTI to multiple UEs 100 .

In step S2, the UE 100 starts monitoring PDCCH in the search space set by the base station 200. For example, DCI format 1_0, DCI format 0_0, DCI format 1_1, DCI format 0_1, DCI format 1_2, and DCI format 0_2 are configured in the UE 100, and the UE 100 monitors the PDCCH (DCI) based on the configuration. For example, base station 200 may configure UE 100 to monitor DCI format 1_0 and DCI format 0_0 in a certain search space. Also, base station 200 may configure UE 100 to monitor DCI format 1_1 and DCI format 0_1 in a certain search space. Also, base station 200 may configure UE 100 to monitor DCI format 1_2 and DCI format 0_2 in a certain search space. That is, for example, base station 200 may configure UE 100 to monitor PDCCH candidates for DCI format 1_0 and DCI format 0_0 when CSS is configured for a certain search space. Also, base station 200 may configure UE 100 to monitor PDCCH candidates for DCI format 2_0 when CSS is configured for a certain search space. In addition, base station 200 instructs UE 100 to monitor PDCCH candidates for DCI format 1_0 and DCI format 0_0 or DCI format 1_1 and DCI format 0_1 when USS is configured for a certain search space. can be set to Also, base station 200 instructs UE 100 to monitor PDCCH candidates for DCI format 1_0 and DCI format 0_0 or DCI format 1_2 and DCI format 0_2 when USS is configured for a certain search space. can be set to

In step S3, the UE 100 receives and detects DCI or PDCCH addressed to itself from the base station 200. For example, the UE 100 is assigned a C-RNTI (Cell-Radio Network Temporary Identifier (RNTI)), an MCS-C-RNTI (Modulation and Coding Scheme-C-RNTI), or a CS-RNTI ( Blind decoding of PDCCH is performed using Configured Scheduling-RNTI), and successfully decoded DCI is acquired as DCI addressed to its own UE. Here, CRC (Cyclic Redundancy Check) parity bits scrambled by C-RNTI, MCS-C-RNTI, or CS-RNTI are added to the DCI (that is, DCI format) transmitted from the base station 200. there is That is, the downlink assignment is appended with CRC parity bits scrambled by C-RNTI, MCS-C-RNTI, or CS-RNTI. Also, CRC parity bits scrambled by C-RNTI, MCS-C-RNTI, or CS-RNTI are added to the uplink grant.

When the DCI indicates PDSCH scheduling, in step S4, the UE 100 receives downlink data from the base station 200 on the scheduled PDSCH. If the DCI indicates PUSCH scheduling, the UE 100 transmits uplink data to the base station 200 on the scheduled PUSCH in step S5. Here, downlink data is also referred to as downlink shared channel (DL-SCH) data. Uplink data is also referred to as uplink-shared channel (UL-SCH) data. Here, the downlink shared channel and the uplink shared channel are transport channels, and PDSCH and PUSCH are physical channels. For example, downlink data (DL-SCH data) is mapped to PDSCH, and uplink data (UL-SCH data) is mapped to PUSCH.

(3) Overview of Power Saving Technology An overview of the power saving technology according to this embodiment will be described.

First, an overview of PDCCH skipping according to this embodiment will be described with reference to FIG. It is assumed below that the UE 100 is in the RRC connected state.

First, the UE 100 monitors the PDCCH provided at predetermined intervals in the search space based on the search space setting set by the base station 200 . In the present embodiment, such a PDCCH monitoring state regarding PDCCH monitoring in UE 100 may be referred to as a PDCCH monitoring execution state for monitoring PDCCH.

Second, the base station 200 transmits to the UE 100 a skip instruction DCI that instructs PDCCH skipping. Skip instruction DCI is an example of switching instruction DCI. A skip indication DCI may be a scheduling DCI or a non-scheduling DCI.

Third, the UE 100 skips PDCCH monitoring for a predetermined period in response to receiving the skip instruction DCI from the base station 200 . The predetermined period for skipping PDCCH monitoring may be set by higher layer signaling (RRC message). The predetermined period may be determined by a timer value (that is, a setting value of a switching timer), or may be determined by the number of consecutive slots or the number of consecutive search spaces. The predetermined period may be referred to as a skipping period. Such PDCCH skipping reduces the power consumption required for the UE 100 to monitor the PDCCH, and can achieve dynamic power saving. Note that PDCCH skipping may mean skipping PDCCH monitoring, and PDCCH skipping may be referred to as PDCCH monitoring skipping. In this embodiment, such a PDCCH monitoring state in the UE 100 may be referred to as a PDCCH skipping state.

Next, an overview of search space set group switching (SSSG switching) according to this embodiment will be described with reference to FIG.

First, the base station 200 configures multiple search space sets, which are sets of settings related to search spaces, in the UE 100 through higher layer signaling (RRC messages). A set of settings related to such a search space is called a Search Space Set (SSS) or a Search Space Set Group (SSSG), but in the following it will be mainly called SSSG. . One SSSG includes one or more search space settings and is identified by an SSSG index. In the example of FIG. 5, base station 200 has SSSG#0 (first search space set) in which search spaces are provided at a predetermined cycle, and SSSG#1 (second search space set) in which search spaces are provided at a cycle longer than the predetermined cycle. space set) shall be set in the UE 100. Here, an example is shown in which the base station 200 sets two SSSGs, SSSG#0 and SSSG#1, to the UE 100. Three or more SSSGs are set for each of one or more BWPs (for example, DL BWP). You may set to UE100. Note that setting a plurality of SSSGs (or three or more SSSGs) in the UE 100 may mean setting a plurality of SSSGs (or three or more SSSGs) for one BWP, or a plurality of may mean setting multiple SSSGs (or three or more SSSGs) for each BWP. Also, considering that search spaces include UE-specific search spaces and/or UE-common search spaces as described above, a set of settings related to UE-specific search spaces may be referred to as a UE-specific search space set. , the set of configurations for UE-common search spaces may be referred to as a UE-common search space set.

Second, the UE 100 monitors the PDCCH provided at predetermined intervals in the search space based on SSSG#0.

Third, the base station 200 transmits to the UE 100 a switching instruction DCI that instructs SSSG switching. The switching instruction DCI may be a scheduling DCI or a non-scheduling DCI. That is, the base station 200 uses DCI to instruct the UE 100 to switch from SSSG#0 to SSSG#1.

Fourth, the UE 100 starts switching to SSSG#1 in response to receiving the switching instruction DCI. UE 100 performs switching to SSSG#1 in a symbol after a switching delay time (Switch delay) from the last symbol of PDCCH in SSSG#0. Such a switching delay time may be set from the base station 200 to the UE 100 by higher layer signaling (RRC message).

Fifth, based on SSSG#1, UE 100 monitors PDCCHs provided in a cycle longer than a predetermined cycle in search spaces. Such search space set switching reduces the power consumption required for UE 100 to monitor the PDCCH, and can achieve dynamic power saving.

Note that switching from SSSG#1 to SSSG#0 may be instructed by the base station 200 using DCI in the same manner as switching from SSSG#0 to SSSG#1, or the UE 100 may switch from SSSG#1 using a timer. You may switch to SSSG#0. The timer value of such a switching timer (Switching timer) is set from the base station 200 to the UE 100 by higher layer signaling (RRC message). The UE 100 starts monitoring the PDCCH in SSSG#1 in response to detection of the switching instruction DCI to SSSG#1, sets the value of the switching timer to the value set by the upper layer, and activates the switching timer. UE 100 decrements the value of the switching timer, stops monitoring PDCCH in SSSG#1 when the switching timer expires, and starts monitoring PDCCH in SSSG#0 after a switch delay time.

"#0" in SSSG#0 and "#1" in SSSG#1 indicate indexes (also called search space group IDs) for sets (groups) of search spaces. That is, one or more search space sets may be associated with a set (group) of search spaces identified by an index. For example, base station 200 may configure a set (group) of search spaces for UE 100 by configuring an index associated with the one or more search space sets. In this embodiment, the name SSSG is merely an example, and any name may be used as long as it is a set (group) of search spaces to which one or more search space sets are associated.

In search space set switching, one SSSG set in the UE 100 is set to have no search space, and switching to the one SSSG is indicated by DCI, thereby realizing the same operation as the PDCCH skipping described above. Also, a search space is set in one SSSG set in the UE 100, and no monitoring opportunity for the search space is set (or a parameter related to the monitoring opportunity is set to a predetermined value (e.g., "0" or "Null"). ), an operation similar to the PDCCH skipping described above may be realized. Hereinafter, in order to facilitate the explanation, as a setting for realizing the same operation as the PDCCH skipping described above, it will be described that there is no search space in one SSSG, but no monitoring opportunity is set (or monitoring setting a parameter related to the opportunity to a predetermined value). Also, in other SSSGs set in the UE 100, it is possible to set them to have a long search space cycle, and to instruct switching to the one SSSG by DCI. In order to realize such an operation, UE 100 is configured with a total of three SSSGs: an SSSG with a normal search space period, an SSSG with no search space period, and an SSSG with a long search space period. Flexible power saving can be realized by setting such various SSSGs in the UE 100 and instructing switching of SSSGs by DCI.

Next, regarding this embodiment, discontinuous reception (DRX) will be described, and the power saving state will be described with reference to FIG.

When DRX is configured in the UE 100, the UE 100 discontinuously monitors the PDCCH using the DRX operation. Specifically, the DRX operation is controlled by the following DRX parameters.
- DRX cycle: Defines the cycle in which the UE 100 wakes up.
On duration (on-duration): This is the period during which the UE 100 waits to receive the PDCCH after waking up. If the UE 100 successfully decodes the PDCCH, the UE 100 remains awake and starts an inactivity-timer.
Inactivity timer: Defines the time period during which the UE 100 waits after the last successful PDCCH decoding and sleeps again when the PDCCH decoding fails. In addition to this, after the inactivity timer expires and a predetermined set value DRX-SlotOffset elapses, the ON duration may be started. FIG. 6 corresponds to the operation with the set value of DRX-SlotOffset set to zero.
• Retransmission timer: defines the time interval during which retransmissions are expected.

In this way, the UE 100 configured with DRX does not need to monitor the PDCCH in the sleep state (that is, the reception off period), so the power consumption of the UE 100 can be reduced. On the other hand, the UE 100 waits to receive the PDCCH and monitors the PDCCH in the search space during the active time. The active time is any of the on duration timer (drx-onDurationTimer), the inactivity timer (drx-InactivityTimer), the downlink retransmission timer (drx-RetransmissionTimerDL), and the uplink retransmission timer (drx-RetransmissionTimerUL) is in operation. It's time.

By performing the above-described PDCCH skipping or search space set switching within the active time of DRX, it is possible to dynamically switch to the power saving state during the active time, and the power consumption is greater than the low power consumption achieved by DRX. A reduction effect can be obtained.

Next, an example of PDCCH monitoring adaptation according to this embodiment will be described with reference to FIG. PDCCH supervisory adaptation is a generic term for PDCCH skipping and SSSG switching. That is, in this embodiment, PDCCH monitoring adaptation may be replaced by PDCCH skipping and/or SSSG switching. In PDCCH monitoring adaptation, a process of switching the PDCCH monitoring state for PDCCH monitoring may be performed.

Here, a plurality of SSSGs having different search space cycles (different PDCCH cycles) and various SSSGs including SSSGs having no search space, one or more SSSGs can be set in the UE 100, and the SSSG's It is assumed that flexible power saving is realized by indicating switching (that is, switching of PDCCH monitoring state) with DCI. Here, in this embodiment, a plurality of SSSGs having different search space cycles (different PDCCH cycles) will be described, but it is possible to set the same search space cycle (different PDCCH cycles) for a plurality of SSSGs. is of course.

As shown in FIG. 7, in step S11, the base station 200 generates one or more RRC messages and transmits the generated RRC messages to the UE100. The one or more RRC messages may include a dedicated RRC message (eg, RRCReconfiguration message) sent for each UE. UE 100 receives the RRC message.

The RRC message includes PDCCH monitoring adaptation settings (hereinafter referred to as PMA settings). The PMA settings may be settings for performing PDCCH monitoring adaptation. PMA setting includes information for setting SSSG, information for setting a switching timer for switching SSSG, information for setting a duration related to PDCCH monitoring, and setting cases related to PDCCH monitoring state switching. may include at least one of information for

Note that the information for setting the case may be information for setting the case (also referred to as operation) of PDCCH monitoring adaptation. As described below, it may be specified to perform PDCCH skipping (ie PDCCH skipping only), for example for the case of PDCCH monitoring adaptation. It may also be specified to perform SSSG switching (ie SSSG switching only) as a case of PDCCH monitoring adaptation. It may also be specified to perform PDCCH skipping and SSSG switching as a case of PDCCH monitoring adaptation. That is, cases may be defined corresponding to operations performed as PDCCH monitoring adaptation.

Information for setting SSSG (hereinafter referred to as SSSG setting information as appropriate) includes, for example, information for setting SSSG to which PDCCH skipping is applied, and information for setting SSSG to which SSSG switching is applied. At least one may be included. The SSSG setting information may also include information for setting at least one of a default SSSG (eg, SSSG#0) and a non-default SSSG that is not the default SSSG. That is, SSSG configuration information may be configured for default SSSG and/or non-default SSSG. The SSSG configuration information may include SSSG information configured for each downlink BWP, and may include SSSG information configured for each downlink serving cell. That is, the SSSG configuration information may be configured for the downlink BWP and/or the downlink serving cell.

The SSSG configuration information may further include a search space configuration associated with each SSSG index (which may be referred to as a group index) corresponding to each SSSG. A search space setting includes one or more search space settings. Each search space configuration includes at least one of search space period, search space offset, search space duration (e.g., number of consecutive slots), symbols for PDCCH monitoring, aggregation level, search space type, and DCI format. OK.

Information for setting a switching timer for switching between SSSGs (hereinafter referred to as switching timer information as appropriate) may include information on switching timers set for each SSSG. The switch timer information may include switch timer information for the default SSSG and may include switch timer information for the non-default SSSG. That is, switching timer information may be configured for default SSSG and/or non-default SSSG. Note that the switching timer may not be set for the default SSSG. Also, the switching timer information may include switching timer information configured for each downlink BWP, and may include switching timer information configured for each downlink serving cell. That is, the switching timer information may be configured for the downlink BWP and/or the downlink serving cell. The switching timer information may include a timer set value of the switching timer.

Information for setting a period related to PDCCH monitoring (hereinafter referred to as monitoring period information as appropriate) may include information on a period set for each SSSG. The monitoring period information may include period information for the default SSSG and may include period information for the non-default SSSG. That is, monitoring period information may be set for default SSSGs and/or non-default SSSGs. The monitoring period information may include information on a period set for each downlink BWP, or may include information on a period set for each downlink serving cell. That is, the monitoring period information may be configured for the downlink BWP and/or the downlink serving cell. The set period may be a skipping period during which PDCCH monitoring is skipped.

A case related to PDCCH monitoring state switching, specifically, information for setting a case of PDCCH monitoring adaptation (hereinafter referred to as case setting information as appropriate) includes case information set for each downlink BWP. Alternatively, it may include case information configured for each downlink serving cell. That is, the case configuration information may be configured for the downlink BWP and/or the downlink serving cell. An example of the correspondence between cases and PDCCH monitoring adaptation (ie, PDCCH monitoring state) behavior is shown in Table 1. Table 1 shows an example of DCI notification contents in each case.

By setting case #1, PDCCH skipping (that is, execution of PDCCH skipping only) is set as PDCCH monitoring adaptation. The configuration for case #2 configures two different durations of SSSG switching (ie performing SSSG switching only) as PDCCH monitoring adaptation. The configuration for case #3 configures SSSG switching for three different durations (ie performing SSSG switching only) as a PDCCH monitoring adaptation. With the configuration of case #4, two different periods of SSSG switching and PDCCH skipping (ie performing PDCCH skipping and SSSG switching) are configured as PDCCH monitoring adaptations. In case #4, M (set to 1 or 2) indicates the number of periods set based on the monitoring period information. That is, M corresponds to period X. Period X may be referred to as a skipping period.

In each case, the value set in the information field (hereinafter referred to as the PDCCH monitoring adaptation notification field) in the switching instruction DCI that indicates the PDCCH monitoring adaptation (that is, SSSG switching and/or PDCCH skipping) applied by the UE 100 is indicated. It is associated with the operation (behavior) of the UE 100. Operations of the UE 100 may be defined as follows.
• PDCCH skipping is not activated on Beh1.
• For Beh1A, PDCCH skipping means stopping PDCCH monitoring for period X.
• Beh2 stops monitoring the search space sets associated with SSSG#1 and SSSG#2 (if configured) and monitors the search space set associated with SSSG#0.
• Beh2A stops monitoring the search space sets associated with SSSG#0 and SSSG#2 (if configured) and monitors the search space set associated with SSSG#1.
• In Beh2B, stop monitoring the search space set associated with SSSG#0 and SSSG#1 (if configured) and monitor the search space set associated with SSSG#2.

The information indicating the correspondence relationship in Table 1 may be stored in advance in each of the UE 100 and the base station 200, or may be notified from the base station 200 to the UE 100 by an RRC message.

When case #1 is configured in the UE 100, the UE 100 has one for PDCCH monitoring for each of one or more downlink BWPs (or each of one or more SSSGs) in a serving cell. Alternatively, multiple periods (including skipping periods) may be set.

When case #2 or case #3 is configured in the UE 100, the UE 100 has one serving cell for each of one or more downlink BWPs (or each of one or more SSSGs). One or more group indices (SSSG indices) may be configured.

When case #4 is configured in the UE 100, the UE 100 has PDCCH for each of one or more downlink BWPs (or each of one or more SSSGs) in a certain serving cell, in a certain serving cell. One or more time periods (including skipping periods) for monitoring may be set. Also, in the UE 100, one or more group indexes (SSSG indexes) are set for each of one or more downlink BWPs (or each of one or more SSSGs) in a serving cell. you can Note that the PDCCH monitoring adaptation notification field in DCI for PDCCH monitoring is defined as 2 bits.

The RRC message may include field settings indicating the presence or absence of the PDCCH monitoring adaptation notification field for each of one or more DCI formats. The switching indication DCI is a DCI having a DCI format indicating that there is a PDCCH monitoring adaptation notification field by field setting. The presence/absence of the PDCCH monitoring adaptation notification field may be configured commonly or independently for non-scheduling DCI and/or scheduling DCI. The presence/absence of the PDCCH monitoring adaptation notification field (presence/absence) may be set commonly for DCI format 1_1 and DCI format 0_1, and commonly for DCI format 1_2 and DCI format 0_2. The presence or absence (presence/absence) of the PDCCH monitoring adaptation notification field may be set commonly for DCI format 1_1 and DCI format 1_2, and commonly for DCI format 0_1 and DCI format 0_2. Here, the field setting indicating presence/absence of the PDCCH monitoring adaptation notification field may be replaced with the PMA setting. That is, the presence of the PDCCH monitoring adaptation notification field in one or more DCI formats may be indicated by configuring the PMA settings for the UE 100 . For example, UE 100 may identify that one or more DCI formats have a PDCCH monitoring adaptation notification field based on the PMA configuration being configured.

The RRC message may include a bit number setting that indicates the number of bits in the PDCCH supervisory adaptation notification field for each of one or more DCI formats. For non-scheduling DCI and/or scheduling DCI, the number of bits of the PDCCH monitoring adaptation notification field may be directly configured commonly or independently. The number of bits of the PDCCH monitoring adaptation notification field may be configured commonly for DCI format 1_1 and DCI format 0_1 and/or commonly for DCI format 1_2 and DCI format 0_2. For example, a PDCCH supervisory adaptation notification field of up to 2 bits is configured for DCI format 1_1 and/or DCI format 0_1, and/or a PDCCH supervisory adaptation notification field of 1 bit is configured for DCI format 1_2 and DCI format 0_2. may be set. The number of bits of the PDCCH monitoring adaptation notification field may be configured commonly for DCI format 1_1 and DCI format 1_2, and commonly for DCI format 0_1 and DCI format 0_2. Here, the number of bits setting indicating the number of bits of the PDCCH supervisory adaptation notification field may be replaced with the PMA setting. That is, the number of bits of the PDCCH monitoring adaptation notification field included in one or more DCI formats may be determined by configuring the PMA settings for the UE 100 . For example, UE 100 may determine the number of bits of the PDCCH monitoring adaptation notification field included in one or more DCI formats according to the number of SSSGs configured based on information for configuring SSSGs. Also, UE 100 may determine the number of bits of the PDCCH monitoring adaptation notification field included in one or more DCI formats according to the number of periods set based on the monitoring period information. Also, UE 100 may determine the number of bits of the PDCCH monitoring adaptation notification field included in one or more DCI formats, depending on the case set based on the case setting information (for example, shown in Table 1. may determine the number of bits to be stored).

In step S12, the UE 100 stores the information set by the base station 200.

In step S13, the base station 200 transmits a switching instruction DCI having a PDCCH monitoring adaptation notification field to the UE 100 on the PDCCH. UE 100 receives the switching instruction DCI on the PDCCH. The UE 100 may determine whether or not the DCI format of the detected DCI corresponds to the switching instruction DCI, based on field settings set by the base station 200 .

In step S14, the UE 100 acquires the value set in the PDCCH monitoring adaptation notification field of the switching instruction DCI received in step S13. UE 100 may specify the number of bits in the PDCCH monitoring adaptation notification field based on the bit number setting set by base station 200 and then acquire the value set in the PDCCH monitoring adaptation notification field. Here, as described above, for example, the UE 100 is based on the number of SSSG indexes set in the UE 100 (i.e., the number of entries in the set SSSG index (list)), and the number of bits of the PDCCH monitoring adaptation notification field is specified. Additionally, the value set in the PDCCH supervisory adaptation notification field may be obtained. For example, when the number of SSSG indexes set in UE 100 is set to "I", UE 100 calculates and identifies the number of bits of the PDCCH monitoring adaptation notification field by an integer value rounded up after the decimal point of log2 (I). good too.

In step S15, the UE 100 changes the PDCCH monitoring state to the state corresponding to the value set in the PDCCH monitoring adaptation notification field (hereinafter referred to as the PDCCH monitoring adaptation notification field value) in the received switching instruction DCI based on the set case. switch. An operation example of the UE 100 according to the number of bits of the PDCCH monitoring adaptation notification field in each case is shown below.

Case #1: PDCCH Supervisory Adaptation Notification field in DCI for PDCCH Monitoring is 1 bit If the PDCCH Supervisory Adaptation Notification field value is '0', no PDCCH skipping is performed.
If the PDCCH monitoring adaptation notification field value is '1', PDCCH skipping is performed during the configured period (the period of the first value).

Case #1: PDCCH supervisory adaptation notification field in DCI for PDCCH supervision is 2 bits If the PDCCH supervisory adaptation notification field value is '00', no PDCCH skipping is performed.
If the PDCCH monitoring adaptation notification field value is '01', PDCCH skipping is performed during the configured period (the period of the first value).
If the PDCCH monitoring adaptation notification field value is '10', PDCCH skipping is performed during the configured period (second value period).
If the PDCCH monitoring adaptation notification field value is '11', PDCCH skipping is performed during the configured period (the period of the third value).

Case #2: If the PDCCH supervisory adaptation notification field in the DCI for PDCCH supervision is 1 bit If the PDCCH supervisory adaptation notification field value is '0', the PDCCH according to the search space set corresponding to group index #0 Start monitoring and stop monitoring the PDCCH according to the search space set corresponding to the other group index value.
If the PDCCH monitoring adaptation notification field value is '1', start monitoring PDCCH according to the search space set corresponding to group index #1, and start monitoring PDCCH according to the search space set corresponding to other group index values. Stop monitoring.

Case #3: If the PDCCH supervisory adaptation notification field in the DCI for PDCCH supervision is 2 bits If the PDCCH supervisory adaptation notification field value is '00', the PDCCH according to the search space set corresponding to group index #0 Start monitoring and stop monitoring the PDCCH according to the search space set corresponding to the other group index value.
If the PDCCH monitoring adaptation notification field value is '01', start monitoring PDCCH according to the search space set corresponding to group index #1, and start monitoring PDCCH according to the search space set corresponding to other group index values. Stop monitoring.
If the PDCCH monitoring adaptation notification field value is '10', start monitoring the PDCCH according to the search space set corresponding to group index #2, and start monitoring the PDCCH according to the search space set corresponding to the other group index value. Stop monitoring.
The definition of when the PDCCH Supervisory Adaptation Notification field value is '11' is reserved.

Case #4: If the number of periods for PDCCH monitoring is set to '1' If the PDCCH Monitoring Adaptation Notification field value is '00', PDCCH monitoring according to the search space set corresponding to group index #0. and stop monitoring the PDCCH according to the search space set corresponding to the other group index value.
If the PDCCH monitoring adaptation notification field value is '01', start monitoring PDCCH according to the search space set corresponding to group index #1, and start monitoring PDCCH according to the search space set corresponding to other group index values. Stop monitoring.
If the PDCCH monitoring adaptation notification field value is '10', PDCCH skipping is performed during the configured period (the period of the first value).
The definition of when the PDCCH Supervisory Adaptation Notification field value is '11' is reserved.

Case #4: If the number of periods for PDCCH monitoring is set to '2' If the PDCCH Monitoring Adaptation Notification field value is '00', PDCCH monitoring according to the search space set corresponding to group index #0. and stop monitoring the PDCCH according to the search space set corresponding to the other group index value.
If the PDCCH monitoring adaptation notification field value is '01', start monitoring PDCCH according to the search space set corresponding to group index #1, and start monitoring PDCCH according to the search space set corresponding to other group index values. Stop monitoring.
If the PDCCH monitoring adaptation notification field value is '10', PDCCH skipping is performed during the configured period (the period of the first value).
If the PDCCH monitoring adaptation notification field value is '11', PDCCH skipping is performed during the configured period (second value period).

Next, an example of timer-based SSSG switching according to this embodiment will be described with reference to FIG. Here, it is assumed that the UE 100 switches between SSSGs on a timer basis and three or more SSSGs can be configured in the UE 100 .

The base station 200 may set one of the SSSGs set in the UE 100 as a default SSSG in the UE 100. For example, the base station 200 may specify one of the SSSG indices set in the UE 100 as "defaultSSSG-Id". For example, the base station 200 may set the 'defaultSSSG-Id' using an RRC message. That is, the base station 200 may configure the default SSSG for the UE 100 using information included in the RRC message. The default SSSG may be an SSSG determined according to a predetermined rule shared in advance by the base station 200 and the UE 100 among SSSGs set in the UE 100 . The default SSSG may be the SSSG set in the UE 100 by the base station 200 as the default SSSG.

As shown in FIG. 8, in step S21, the UE 100 for which multiple SSSGs have been set by the base station 200 monitors the PDCCH using one of the multiple SSSGs.

In step S22, the UE 100 receives a switching instruction DCI that instructs switching to another SSSG from the base station 200 on the PDCCH.

In step S23, the UE 100 switches to the SSSG specified by the switching instruction DCI and activates the timer (switching timer) associated with the SSSG.

In step S24, the UE 100 determines whether the switching timer has expired.

When the switching timer expires (step S24: YES), in step S25, the UE 100 switches to the default SSSG among the multiple set SSSGs. Here, by switching to the SSSG specified by the base station 200 as “defaultSSSG-Id”, the base station 200 can grasp the SSSG to which the UE 100 is switched. Since the switching timer is a value set by the base station 200, the base station 200 manages the switching timer in the same manner as the UE 100, and can recognize that the switching timer has expired in the UE 100.

If the default SSSG is not set by the base station 200, specifically, if the default SSSG is not explicitly specified by the base station 200 as "defaultSSSG-Id", the UE 100 determines the default SSSG according to a predetermined rule. do. For example, if the RRC message does not contain information for setting the default SSSG, the UE 100 may determine the default SSSG according to a predetermined rule. The predetermined rule is, for example, a rule defined by 3GPP technical specifications, and a rule shared in advance by the base station 200 and the UE 100 .

Here, the predetermined rule is the SSSG corresponding to the SSSG index with the smallest value among the SSSG indexes set in the UE 100, or the SSSG corresponding to the SSSG index with the largest value. good. For example, if the rule is to set the SSSG corresponding to the SSSG index with the smallest value as the default SSSG, the UE 100 determines the SSSG with SSSG index #0 as the default SSSG. If the rule is to set the SSSG corresponding to the SSSG index with the largest value as the default SSSG, the UE 100 determines the SSSG of SSSG index #4 as the default SSSG.

As described above, the UE 100 may receive from the base station 200 correspondence information indicating the correspondence between the SSSG index set in the UE 100 and the value set in the SSSG information field in the switching instruction DCI. The predetermined rule may be a rule for determining, as the default SSSG, the SSSG corresponding to the SSSG index indicated by a specific value (eg, "0") set in the SSSG information field in the switching instruction DCI. For example, the UE 100 determines, as the default SSSG, an SSSG having an SSSG index in which the value set in the SSSG information field in the switching instruction DCI is "0".

The predetermined rule may be a rule that determines the SSSG corresponding to the SSSG index (for example, index #0) having a predetermined value among the SSSG indices set in the UE 100 as the default SSSG.

The predetermined rule may be a rule for determining, among the SSSGs set in the UE 100, SSSGs other than SSSGs skipping PDCCH monitoring as default SSSGs. That is, UE 100 may assume that the SSSG index corresponding to PDCCH skipping is not set as the default SSSG.

When DRX is configured in the UE 100, the UE 100 may apply a specific SSSG when switching from a DRX reception off period to a reception on period (active time). The predetermined rule may be a rule that determines that particular SSSG as the default SSSG. That is, the UE 100 may determine the first SSSG to monitor the PDCCH after the DRX reception off period has elapsed as the default SSSG. For example, the base station 200 may transmit an RRC message including information for setting the specific SSSG, and the UE 100 may determine the specific SSSG as the default SSSG. In addition, the base station 200 transmits an RRC message including information for setting the default SSSG, and the UE 100 uses the default SSSG as the first SSSG to monitor the PDCCH after the DRX reception off period has passed. good too.

The UE 100 may receive a scheduling DCI indicating radio resources allocated to the UE 100 as a switching instruction DCI. After receiving the scheduling DCI as the switching instruction DCI, the UE 100 may start the switching timer at the timing of switching to one SSSG (specifically, the slot for performing SSSG switching).

The UE 100 may use a common value as the switching timer value applied to two or more of the three or more SSSGs set in the UE 100 . The base station 200 may set a common value as the switching timer value applied to two or more SSSGs among the three or more SSSGs set in the UE 100 .

The UE 100 may use an individual value for each SSSG as the switching timer value applied to each SSSG set in the UE 100 . The base station 200 may set an individual switching timer setting value in the UE 100 for each SSSG.

When the switching destination SSSG is an SSSG that supports PDCCH skipping, the UE 100 may activate the switching timer associated with the SSSG at the timing (slot) at which switching to the SSSG is started. When in the PDCCH skipping state, that is, during a predetermined period during which PDCCH monitoring is skipped, resources used for PDCCH monitoring are not dedicated, and switching to the relevant SSSG can be started at any timing. Taking advantage of this advantage, it is possible to minimize the effect of the switching delay time without disturbing the PDCCH monitoring operation. Note that the UE 100 may monitor the PDDCH assuming the default SSSG after the switching timer expires.

(4) Overview of BWP switching based on expiration of BWP switching timer An overview of BWP switching based on expiration of the BWP switching timer according to the present embodiment will be described.

An outline of BWP switching based on expiration of the BWP switching timer according to the present embodiment will be described with reference to FIG.

In step S31, the base station 200 transmits an RRC message to the UE100. UE 100 receives the RRC message from base station 200 . UE 100 stores the information set by the RRC message.

The RRC message may include BWP settings for setting BWP to the UE 100. The RRC message may also include BWP switching timer information for setting a BWP switching timer for switching BWP.

The BWP configuration may include, for example, information for downlink BWP (ie BWP-Downlink) and/or information for uplink BWP (ie BWP-Uplink). Note that the BWP setting may include BWP switching timer information.

The BWP switching timer information may include a timer value for setting the BWP switching timer. The BWP switching timer may be set for each cell (or for each frequency) set in the UE 100. The BWP switching timer information may be included in the serving cell configuration (ServingCellConfig) used to configure (add or modify) the serving cell to the UE 100. That is, the BWP switching timer may be set for the serving cell.

A BWP switching timer is, for example, a BWP inactivity timer (bwp-InactivityTimer). The BWP inactivity timer indicates the duration in ms before the UE 100 falls back to default BWP. The UE 100 switches (that is, falls back) from the active BWP to the default BWP based on the expiration of the BWP inactivity timer. The UE 100 switches to the initial BWP when the default BWP is not set.

In addition, in the case of UE 100 in an RRC connected state in which carrier aggregation (CA) or dual connectivity (DC) is not set, the serving cell consists of a primary cell (PCell).There is only one serving cell. For UE 100 in the RRC connected state where CA or DC is configured, the serving cell is a set of cells configured with a special cell (SpCell) and all secondary cells (SCell). For dual connectivity operation, the special cell is the primary cell (PCell) of the master cell group (MCG) or the secondary primary cell (PSCell) of the secondary cell group. Otherwise, the special cell is the primary cell. The secondary cell (SCell) is a cell that provides additional radio resources to the top of the special cell in the case of UE 100 configured with carrier aggregation (CA).

In step S32, the UE 100 starts the BWP switching timer. UE 100 specifically starts a BWP switching timer associated with the active BWP. For example, UE 100 starts a BWP switching timer for a serving cell configured with a BWP indicated as an active BWP.

In step S33, the BWP switching timer expires.

In step S34, the UE 100 switches the BWP (specifically, the active BWP) based on the expiration of the BWP switching timer. As described above, for example, when the BWP switching timer expires and the default BWP is set, the UE 100 may switch the BWP to the default BWP as the active BWP. Also, when the BWP switching timer expires and the default BWP is not set, the UE 100 may switch the BWP to the initial BWP as the active BWP. Here, the BWP (eg, active BWP, default BWP, and/or initial BWP) is the downlink BWP (specifically, active downlink BWP, default downlink BWP, and/or initial downlink BWP) may be Also, the BWP (for example, active BWP, default BWP, and/or initial BWP) is an uplink BWP (specifically, active uplink BWP, default uplink BWP, and/or initial uplink BWP). There may be.

As described above, the UE 100 switches the BWP based on the expiration of the BWP switching timer. Such a BWP switch may occur in a power saving state (that is, in a state of lengthening the PDCCH monitoring period or skipping PDCCH monitoring) by performing PDCCH monitoring adaptation.

Here, when the UE 100 switches the BWP based on the expiration of the BWP switching timer, there is a possibility that the actual PDCCH monitoring state in the UE 100 and the PDCCH monitoring state recognized by the base station 200 will not match. Therefore, there is a concern that the base station 200 cannot properly perform radio communication with the UE 100 after the UE 100 switches the PDCCH monitoring state. Also, even if UE 100 executes PDCCH monitoring adaptation before switching BWP, it is unknown how PDCCH monitoring adaptation is executed in BWP after switching. Therefore, in the present embodiment, in a mobile communication system in which the PDCCH monitoring state is switched based on the expiration of the BWP switching timer, even when the BWP is switched based on the expiration of the BWP switching timer, wireless communication is appropriately performed. make it possible.

Here, the "PDCCH monitoring state" in this embodiment may include skipping PDCCH monitoring and/or performing PDCCH monitoring in the configured SSSG. For example, switching the PDCCH monitoring state may include switching the operation from skipping PDCCH monitoring to monitoring PDCCH with the configured SSSG. Also, switching the PDCCH monitoring state may include switching the operation from the operation of monitoring the PDCCH in the configured SSSG to the operation of skipping the monitoring of the PDCCH. In addition, switching the PDCCH monitoring state includes switching the operation from the operation of monitoring the PDCCH in the set first SSSG to the operation of monitoring the PDCCH in the set second SSSG. good too.

Also, switching the PDCCH monitoring state may include switching the SSSG used for PDCCH monitoring. For example, switching the PDCCH monitoring state may include switching the SSSG from the SSSG configured for PDCCH skipping to the SSSG configured for PDCCH monitoring. Also, switching the PDCCH monitoring state may include switching the SSSG from the SSSG configured for PDCCH monitoring to the SSSG configured for PDCCH skipping. Also, switching the PDCCH monitoring state may include switching the SSSG from the first SSSG set for PDCCH monitoring to the second SSSG set for PDCCH monitoring.

That is, in the present embodiment, switching the PDCCH monitoring state may correspond to execution of PDCCH monitoring adaptation. Here, in the present embodiment, the SSSG used for PDCCH monitoring is also referred to as a PDCCH monitoring state for ease of explanation. Also, as described above, the set SSSG includes a default SSSG.

(5) Configuration of User Equipment A configuration of the UE 100 according to the present embodiment will be described with reference to FIG. UE 100 includes communication unit 110 and control unit 120 .

The communication unit 110 performs wireless communication with the base station 200 by transmitting and receiving wireless signals to and from the base station 200 . The communication unit 110 has at least one transmitter 111 and at least one receiver 112 . The transmitting section 111 and the receiving section 112 may be configured including an antenna and an RF circuit. The antenna converts a signal into radio waves and radiates the radio waves into space. Also, the antenna receives radio waves in space and converts the radio waves into signals. The RF circuitry performs analog processing of signals transmitted and received through the antenna. The RF circuitry may include high frequency filters, amplifiers, modulators, low pass filters, and the like.

The control unit 120 performs various controls in the UE 100. Control unit 120 controls communication with base station 200 via communication unit 110 . The operations of the UE 100 described above and below may be operations under the control of the control unit 120 . The control unit 120 may include at least one processor capable of executing a program and a memory that stores the program. The processor may execute a program to operate the control unit 120 . The control unit 120 may include a digital signal processor that performs digital processing of signals transmitted and received through the antenna and RF circuitry. The digital processing includes processing of the protocol stack of the RAN. Note that the memory stores programs executed by the processor, parameters related to the programs, and data related to the programs. The memory is ROM (Read Only Memory), EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), RAM (Random Access Mem ory) and flash memory. All or part of the memory may be included within the processor.

The UE 100 according to the present embodiment performs wireless communication in a bandwidth portion that is part of the total bandwidth of the cell of the base station 200. The control unit 120 switches the bandwidth portion based on the expiry of the BWP switching timer for switching the bandwidth portion, and switches the PDCCH monitoring state regarding monitoring of the physical downlink control channel (PDCCH). may be processed. The receiving unit 112 receives a radio resource control (RRC) message including switching control information for controlling the BWP timer-based switching process. The control unit 120 controls the switching process caused by the BWP timer based on the switching control information. As a result, it becomes possible to switch the PDCCH monitoring state based on the expiration of the BWP switching timer under the control of the base station 200, and even when switching the BWP based on the expiration of the BWP switching timer, wireless communication can be appropriately performed. It becomes possible to go to

Also, the switching control information may be information regarding whether to enable execution of the BWP timer-based switching process. The control unit 120 may perform the switching process caused by the BWP timer based on the switching control information indicating that the execution of the switching process caused by the BWP timer is enabled. As a result, the base station 200 explicitly indicates the validity/invalidity of execution of the switching process caused by the BWP timer, causing a discrepancy between the actual PDCCH monitoring state in the UE 100 and the PDCCH monitoring state recognized by the base station 200. can be further reduced.

The switching control information may be included in the PDCCH configuration for configuring UE-specific PDCCH parameters. For example, compared to the case where the switching control information is included in an information element different from the PDCCH setting, when changing the switching control information included in the PDCCH setting and another parameter, the switching control information ( change) can be notified to the UE 100. The base station 200 can also control switching of the PDCCH monitoring state based on expiration of the BWP switching timer when changing settings based on the PDCCH settings.

The switching control information may include information for setting a search space set group (SSSG) for monitoring the PDCCH in the switched bandwidth portion based on the expiration of the BWP switching timer. Thereby, the base station 200 can set the SSSG after switching based on the expiration of the BWP switching timer, and can control switching of the PDCCH monitoring state based on the expiration of the BWP switching timer.

The receiving unit 112 may receive from the base station 200 an instruction to switch to the PDCCH skipping state in which PDCCH monitoring is skipped as the PDCCH monitoring state. The control unit 120 may stop the BWP switching timer based on switching to the PDCCH skipping state according to the instruction. That is, the control unit 120 stops the BWP switching timer based on the reception (detection) of the switching instruction DCI that instructs PDCCH skipping (that is, the PDCCH monitoring adaptation notification field set to a value that instructs PDCCH skipping). good. This makes it possible to perform control so that the BWP switching timer does not expire while UE 100 is performing PDCCH skipping. As a result, the control unit 120 does not switch the BWP based on the expiration of the BWP switching timer during PDCCH monitoring adaptation. For example, even when the UE 100 switches the PDCCH monitoring state so that the PDCCH monitoring state switching process differs for each BWP, the UE 100 can appropriately switch the PDCCH monitoring state.

Also, the control unit 120 may start or restart the BWP switching timer based on switching from the PDCCH skipping state to the PDCCH monitoring state. For example, the control unit 120 starts or restarts the BWP switching timer based on the reception (detection) of the switching instruction DCI that instructs SSSG switching (that is, the PDCCH monitoring adaptation notification field set to a value that instructs SSSG switching). You can Also, the control unit 120 may start or restart the BWP switching timer based on expiration of the skipping period timer. As a result, control section 120 switches the BWP based on the expiration of the BWP switching timer only when monitoring the PDCCH, so UE 100 can avoid the continuous unusability of the BWP switching timer. can.

When the BWP switching timer expires in all the secondary cells set in the UE 100, the control unit 120 may switch the PDCCH monitoring state to the PDCCH monitoring state in the special cell set in the UE 100. For example, in a special cell, the control unit 120 may switch the PDCCH monitoring state to a state in which the PDCCH is monitored using the SSSG set for PDCCH monitoring. That is, the control unit 120 monitors the PDCCH in the special cell based on expiration of the BWP switching timer associated with the secondary cell (for example, based on expiration of all BWP switching timers associated with the secondary cell). good too. Here, the SSSG used to monitor the PDCCH may be the SSSG configured for the special cell (downlink BWP in the special cell). This enables UE 100 to monitor the PDCCH in the special cell, so base station 200 can control UE 100 even if BWP in all secondary cells is deactivated.

The BWP (eg, downlink BWP) in the special cell may be the default BWP (eg, default downlink BWP) set as default by the base station 200 or the initial BWP (eg, initial downlink BWP). The control unit 120 may monitor the PDCCH in the default BWP or initial BWP based on the switching control information. Thereby, the base station 200 can grasp that the UE 100 is monitoring the PDCCH in the default BWP or the initial BWP, and there is no discrepancy between the actual PDCCH monitoring state in the UE 100 and the PDCCH monitoring state recognized by the base station 200. What happens can be further reduced.

The switching control information may include information for setting a search space set group (SSSG) for monitoring PDCCH in the default BWP or initial BWP. The control unit 120 may monitor the PDCCH based on the SSSG set by the switching control information in the default BWP or initial BWP. The base station 200 can grasp the SSSG in which the UE 100 monitors the PDCCH in the default BWP or the initial BWP, and the actual PDCCH monitoring state in the UE 100 and the PDCCH monitoring state recognized by the base station 200 do not match. Further reduction is possible.

Also, the control unit 120 controls switching processing for switching the PDCCH monitoring state related to monitoring of the physical downlink control channel (PDCCH) in a predetermined BWP out of one or a plurality of BWPs set in the UE 100 . The receiving unit 112 receives a radio resource control (RRC) message including switching control information for controlling switching processing. The controller 120 controls the switching process in a given bandwidth portion using switching settings for the given bandwidth portion based on the switching control information when the given bandwidth portion is activated. The control unit 120 suspends switching settings when a predetermined bandwidth portion is deactivated. As a result, when the predetermined BWP is deactivated, the UE 100 suspends the switching setting for the predetermined BWP, thereby discarding (or clearing) the switching setting. control can be started earlier.

The control unit 120 restores (starts, resumes, (re- ) and the restored switching settings may be used to control the switching process. Thereby, the UE 100 can hasten the start of control of the switching process at the predetermined BWP.

The predetermined bandwidth portion may be a portion of the total bandwidth of the secondary cell. The control unit 120 discards (or clears) the suspended switching setting when the secondary cell is deactivated based on the expiration of the timer for deactivating the secondary cell (that is, the serving cell). good. When the secondary cell is deactivated based on the expiration of the timer for deactivating the secondary cell, by clearing the switching setting set for the secondary cell, the processing of UE 100 (control unit 120) It can reduce the load.

(6) Configuration of Base Station The configuration of the base station 200 according to this embodiment will be described with reference to FIG. Base station 200 has communication unit 210 , network interface 220 , and control unit 230 .

For example, the communication unit 210 receives radio signals from the UE 100 and transmits radio signals to the UE 100. The communication unit 210 has at least one transmitter 211 and at least one receiver 212 . The transmitting section 211 and the receiving section 212 may be configured including an antenna and an RF circuit. The antenna converts a signal into radio waves and radiates the radio waves into space. Also, the antenna receives radio waves in space and converts the radio waves into signals. The RF circuitry performs analog processing of signals transmitted and received through the antenna. The RF circuitry may include high frequency filters, amplifiers, modulators, low pass filters, and the like.

The network interface 220 transmits and receives signals to and from the network. The network interface 220, for example, receives signals from adjacent base stations connected via an Xn interface, which is an interface between base stations, and transmits signals to adjacent base stations. Also, the network interface 220 receives signals from the core network device 300 connected via the NG interface, for example, and transmits signals to the core network device 300 .

The control unit 230 performs various controls in the base station 200. The control unit 230 controls communication with the UE 100 via the communication unit 210, for example. Also, the control unit 230 controls communication with nodes (for example, adjacent base stations, core network device 300) via the network interface 220, for example. The operations of the base station 200 described above and below may be operations under the control of the control unit 230 . The control unit 230 may include at least one processor capable of executing programs and a memory storing the programs. The processor may execute a program to operate the controller 230 . Control unit 230 may include a digital signal processor that performs digital processing of signals transmitted and received through the antenna and RF circuitry. The digital processing includes processing of the protocol stack of the RAN. Note that 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 included within the processor.

The base station 200 according to this embodiment performs radio communication with the UE 100 in a bandwidth portion that is part of the total bandwidth of the cell of the base station 200. The control unit 230 generates a radio resource control (RRC) message including switching control information for controlling the BWP timer-based switching process in the UE 100 . Transmission section 211 transmits the RRC message to UE 100 . In the BWP timer-based switching process, the UE 100 switches the bandwidth part and switches the PDCCH monitoring state for monitoring the physical downlink control channel (PDCCH) based on the expiration of the BWP switching timer for switching the bandwidth part. As a result, it is possible to switch the PDCCH monitoring state based on the expiration of the BWP switching timer under the control of the base station 200, and it is possible to appropriately perform wireless communication even when switching the PDCCH monitoring state. Become.

(7) Operation of Mobile Communication System (7.1) First Operation Example Assuming the configuration and operation described above, a first operation example of the mobile communication system 1 will be described with reference to FIGS. 12 and 13. FIG. Note that differences from the above description will be mainly described.

In step S101, the base station 200 (transmitting section 211) transmits an RRC message to the UE100. The RRC message may be a dedicated RRC message (eg, RRCReconfiguration message) sent for each UE. UE 100 (receiving unit 112) receives the RRC message.

The RRC message includes switching control information for controlling switching processing for switching the PDCCH monitoring state based on the expiration of the BWP switching timer for switching BWP (hereinafter referred to as BWP timer-induced switching processing as appropriate). The switching control information may be included, for example, in a PDCCH configuration (PDCCH-Config) for configuring user equipment-specific PDCCH parameters.

The switching control information may include common parameters (for example, common settings) commonly applied to switching processing triggered by a trigger different from expiration of the BWP switching timer and different switching processing. Therefore, the common parameters are, for example, BWP timer-induced switching processing, CG-induced switching processing for switching the PDCCH monitoring state in response to CG transmission, which is uplink transmission based on the configuration grant (CG) from the base station 200, scheduling request (SR ), and RACH-induced switching processing for switching the PDCCH monitoring state according to RACH (Random Access Channel) transmission (or PRACH (Physical RACH) transmission). may be applied. Thereby, the UE 100 (control unit 120) can execute various switching processes based on the common parameter and triggered by a plurality of triggers. In this embodiment, in addition to switching processing based on expiration of the BWP switching timer, switching processing based on multiple types of voluntary uplink transmission may be performed. Note that multiple types of spontaneous uplink transmission may include transmission of a scheduling request (SR). Also, multiple types of spontaneous uplink transmission may include RACH transmission (or PRACH transmission). Also, multiple types of spontaneous uplink transmission may include CG transmission.

The switching control information may include individual parameters (for example, individual settings) individually applied to each switching process. Therefore, the individual parameters are, for example, parameters that are applied only to control the BWP timer-based switching process, parameters that are applied only to control the CG-based switching process, and parameters that are applied only to control the SR-based switching process. and/or parameters that only apply to control the RACH-triggered handover process.

Individual parameters may indicate settings that are not set by common parameters. Alternatively, individual parameters may indicate settings that are prioritized over common parameters. Also, the individual parameter may indicate whether to enable (or set) execution of the BWP timer-based switching process (BWP timer-based switching). For example, the individual parameter may include information (eg, 1-bit flag information) indicating whether to enable or disable execution of the BWP timer-triggered switching process (BWP timer-triggered switching). good. In addition, the individual parameter includes information (for example, 1-bit flag information) indicating whether to enable or disable execution of each other switching process (or each switching described above). It's okay. As a result, the UE 100 (control unit 120) can execute various effective switching processes based on the individual parameter and triggered by at least one of the above-described triggers. Note that the common parameter may include 1-bit flag information indicating whether to enable or disable each switching process.

Also, the RRC message may include BWP settings. The BWP configuration may contain individual parameters that only apply to control the BWP timer triggered switching process.

Therefore, the PDCCH configuration may include common parameters and individual parameters. Also, the BWP configuration may include individual parameters that are not included in the PDCCH configuration. Also, the PDCCH configuration may contain only common parameters and the BWP configuration may contain dedicated parameters. Note that the switching control information may be included in an information element different from the PDCCH setting.

When receiving the switching control information, the UE 100 (control unit 120) determines (or identifies) that execution of the BWP timer-induced switching process (or BWP timer-induced switching) is enabled (or set). good too. When receiving the switching control information, the UE 100 (control unit 120) may determine that execution of the BWP timer-based switching process (or BWP timer-based switching) is enabled (or set).

The switching control information may, for example, configure PDCCH monitoring adaptation (or execution of the PDCCH monitoring adaptation) based on expiration of the BWP switching timer.

As described above, the switching control information may include PDCCH monitoring adaptation settings (PMA settings). Therefore, the switching control information may include at least one of SSSG configuration information, switching timer information, monitoring period information, and case configuration information. The UE 100 (control unit 120) may determine that execution of the BWP timer-based switching process is enabled (set) when the RRC message includes the PMA setting.

Note that the switching control information may include at least one of the information included in the PMA settings. Accordingly, the switching control information may be at least part of the information included in the PMA configuration, for example. The switch control information may include, for example, information to configure a search space set group (SSSG) for monitoring PDCCH in a switched BWP based on expiry of a BWP switch timer.

The switching control information may be information for controlling the BWP timer-based switching process in each cell, each frequency, or each BWP set in the UE 100. Therefore, the BWP timer-based switching process may differ for each cell, each frequency, or each BWP.

Also, the switching control information may be included only in the BWP configuration without being included in the PDCCH configuration. In this case, the switching control information may be information for controlling the switching process caused by the BWP timer. The switching control information included in the BWP settings may not include information for controlling other switching processes.

Also, the switching control information may be information regarding whether to enable (or set) execution of the BWP timer-based switching process. The UE 100 (control unit 120) may perform the switching process caused by the BWP timer based on the switching control information indicating that the switching process caused by the BWP timer is enabled.

Also, the UE 100 (control unit 120) may perform control so that the BWP timer-based switching process is not performed when the RRC message does not include switching control information. For example, the UE 100 (control unit 120) is not set to enable execution of the BWP timer-induced switching process, and/or the PDCCH monitoring state of the switching destination when performing the BWP timer-induced switching process (for example, SSSG ) is not set, even if the BWP is switched based on the expiration of the BWP switching timer, the BWP timer-based switching process is not performed. This can prevent the actual PDCCH monitoring state in UE 100 and the PDCCH monitoring state recognized by base station 200 from being inconsistent.

Note that the RRC message may include information indicating the setting for switching the PDCCH monitoring state in step S104 (that is, the setting for switching the PDCCH monitoring state at a trigger other than the expiration of the BWP switching timer).

Based on the BWP setting, the UE 100 (control unit 120) switches a predetermined BWP (for example, BWP#1) out of one or a plurality of BWPs set in the UE 100 to the active BWP, and performs wireless communication with the base station 200. used for

In step S102, the UE 100 (control unit 120) starts the BWP switching timer based on the BWP switching timer information. As shown in FIG. 13, at time t11, the UE 100 (control unit 120) starts the BWP switching timer.

In step S103, the base station 200 (transmitting section 211) transmits a switching instruction DCI that instructs PDCCH skipping or SSSG switching to the UE 100 on the PDCCH. UE 100 (receiving unit 112) receives the switching instruction DCI. FIG. 13 illustrates a case where switching instruction DCI instructing PDCCH skipping is transmitted to UE 100 on PDCCH. The switching instruction DCI may be an instruction for switching to the PDCCH skipping state in which PDCCH monitoring is skipped as the PDCCH monitoring state. For example, when receiving a switching instruction DCI that instructs PDCCH skipping, UE 100 (control unit 120) detects a PDCCH monitoring adaptation notification field set to a value that instructs PDCCH skipping, based on the received switching instruction DCI. you can In addition, when the UE 100 (control unit 120) receives a switching instruction DCI that instructs SSSG switching, the UE 100 detects the PDCCH monitoring adaptation notification field set to a value that instructs SSSG switching based on the received switching instruction DCI. may

In step S104, the UE 100 (control unit 120) switches the PDCCH monitoring state in response to receiving the switching instruction DCI. For example, when PDCCH skipping is set, UE 100 (control unit 120) is set in the switching instruction DCI (skip instruction DCI) (specifically, according to the detected PDCCH monitoring adaptation notification field) , monitoring of the PDCCH may be skipped for a predetermined period of time (a set predetermined period of time). When SSSG switching is set, the UE 100 (control unit 120) may switch to the SSSG indicated by the switching instruction DCI according to the value set in the switching instruction DCI. As a result, UE 100 enters a power saving state in which power consumption required for PDCCH monitoring is reduced.

In step S105, the BWP switching timer expires. In FIG. 13, at time t12, the BWP switching timer expires.

In step S106, the UE 100 (control unit 120) switches the BWP based on the expiration of the BWP switching timer. UE 100 (control unit 120) switches the active BWP to the default BWP (for example, BWP#0). The UE 100 (control unit 120) switches to the initial BWP when the default BWP is not set. As a result, the default BWP is activated, and BWP#1 used by the UE 100 for wireless communication is deactivated.

In step S107, the UE 100 (control unit 120) switches the PDCCH monitoring state in the post-switching BWP based on the expiration of the BWP switching timer (BWP timer-induced switching processing). The UE 100 (control unit 120) controls the switching process caused by the BWP timer based on the switching control information.

The BWP timer-based switching process is a process of switching the PDCCH monitoring state from the first monitoring state to the second monitoring state. The first monitoring state may correspond to the power saving state described above. The second monitoring state may be a state in which the PDCCH is monitored more frequently than in the first monitoring state. This makes it easier to cope with wireless communication (data communication) that occurs after switching the BWP based on the expiration of the BWP switching timer. That is, UE 100 (control unit 120) may perform the above-described PDCCH skipping and/or SSSG switching based on expiration of the BWP switching timer. Also, the BWP timer triggered switching process may correspond to a process related to PDCCH skipping and/or SSSG switching based on expiration of the BWP switching timer.

For example, the first monitoring state may be a state in which PDCCH is monitored in a first period, and the second monitoring state may be a state in which PDCCH is monitored in a second period shorter than the first period. That is, in the second monitoring state, the search space period interval may be shorter than in the first monitoring state. For example, UE 100 (control unit 120), SSSG switching is set, after DCI instructs switching to SSSG having a long PDCCH monitoring cycle, based on the expiration of the BWP switching timer, a short PDCCH monitoring cycle Switch to SSSG with

Also, the first monitoring state may be a PDCCH skipping state in which PDCCH is not monitored (that is, PDCCH skipping), and the second monitoring state may be a state in which PDCCH is periodically monitored. Therefore, the BWP timer-based switching process may be a process of switching the PDCCH monitoring state from the PDCCH skipping state to the PDCCH monitoring state (that is, the PDCCH monitoring execution state). For example, the UE 100 (control unit 120) is set to PDCCH skipping, and after being instructed by the DCI to perform PDCCH skipping, switches to the state of monitoring the PDCCH according to CG transmission. Note that the UE 100 (control unit 120) may stop or cancel execution of PDCCH skipping as a process of switching to the PDCCH monitoring execution state.

The UE 100 (control unit 120) may perform the BWP timer-based switching process only when performing BWP switching based on the expiration of the BWP switching timer when the UE 100 (control unit 120) itself is in the power saving state. That is, UE 100 (control unit 120), in the period during which PDCCH skipping is performed (predetermined period that is set), only when performing BWP switching based on the expiration of the BWP switching timer, the BWP timer caused switching process. you can go That is, the UE 100 (control unit 120) does not need to perform the BWP timer-based switching process when switching the BWP based on the expiration of the BWP switching timer when the UE 100 (control unit 120) itself is not in the power saving state. Alternatively, the UE 100 (control unit 120) may perform the CG-induced switching process only when performing BWP switching based on the expiration of the BWP switching timer in a state where PDCCH skipping and/or SSSG switching are set. That is, UE 100 (control unit 120) does not need to perform the BWP timer-based switching process when PDCCH skipping and/or SSSG switching are not set. In this way, when the UE 100 (control unit 120) performs BWP switching based on the expiration of the BWP switching timer, if the PDCCH monitoring state is the PDCCH skipping state, the BWP timer-induced switching process is performed based on the switching control information. You can control it.

When UE 100 (control unit 120) performs BWP switching based on the expiration of the BWP switching timer, the PDCCH monitoring state indicates that among a plurality of search space set groups (SSSG) having different search space cycles, the search space cycle is When the SSSG equal to or greater than the predetermined value is applied, the BWP timer-based switching process may be controlled based on the switching control information. The switching control information may contain information indicating a predetermined value.

The UE 100 (control unit 120) may perform the BWP timer-based switching process only when the switching control information indicates that the execution of the BWP timer-based switching process (or the BWP timer-based switching) is enabled. When the UE 100 (control unit 120) performs the BWP timer-induced switching process based on the switching control information indicating that the execution of the BWP timer-induced switching process (or the BWP timer-induced switching) is enabled, the BWP timer-induced switching is performed. The process may switch to a predetermined PDCCH monitoring state. The predetermined PDCCH monitoring state may be the default SSSG described above or a non-default SSSG different from the default SSSG.

UE 100 (control unit 120), when the PDCCH monitoring state (for example, SSSG) of the switching destination by the BWP timer-based switching process is specified (set) by switching control information, PDCCH monitoring specified (set) by switching control information You can switch to state. For example, if the switching control information specifies (sets) an index indicating the SSSG after switching by the switching process caused by the BWP timer, the UE 100 (control unit 120) switches to the SSSG indicated by the index.

As described above, the UE 100 (control unit 120) controls the switching process caused by the BWP timer based on the switching control information transmitted from the base station 200. As a result, it becomes possible to switch the PDCCH monitoring state based on the expiration of the BWP switching timer under the control of the base station 200, and even if the PDCCH monitoring state is switched based on the expiration of the BWP switching timer, wireless communication can be performed. can be done properly.

(7.2) Second Operation Example A second operation example of the mobile communication system 1 will be described with reference to FIGS. 14 and 15. FIG. Note that differences from the above description will be mainly described. In the second operation example, UE 100 (control unit 120) stops the BWP switching timer based on switching to the PDCCH skipping state.

Steps S201 and S202 are the same as steps S101 and S102.

As shown in FIG. 15, at time t21, the UE 100 (control unit 120) starts the BWP switching timer.

Note that the switching control information may include information indicating a timer value for setting a predetermined period for skipping PDCCH monitoring. Hereinafter, a timer that counts a predetermined period of time will be referred to as a skipping period timer. UE 100 may maintain the PDCCH monitoring skipping state while the skipping period timer is in operation.

Note that, as shown in FIG. 15, UE 100 (control unit 120) uses BWP #1 as an active BWP for wireless communication with base station 200. FIG.

Steps S203 and S204 are the same as steps S103 and S104.

In step S205, the UE 100 (control unit 120) switches the PDCCH monitoring state to the PDCCH skipping state (first monitoring state) based on the switching instruction DCI.

The UE 100 (control unit 120) starts the skipping period timer based on the switching of the PDCCH monitoring state according to the switching instruction DCI. Also, the UE 100 (control unit 120) stops the BWP switching timer based on the switching of the PDCCH monitoring state according to the switching instruction DCI. UE 100 (control unit 120), for example, based on the reception (and detection) of the switching instruction DCI indicating PDCCH skipping (that is, the PDCCH monitoring adaptation notification field set to a value indicating PDCCH skipping), the BWP switching timer can be stopped. In FIG. 15, at time t22, the UE 100 (control unit 120) starts the skipping period timer and stops the BWP switching timer.

In step S206, the UE 100 (control unit 120) switches the PDCCH monitoring state from the PDCCH skipping state (first monitoring state) to the PDCCH monitoring execution state (second monitoring state) based on the expiration of the skipping period timer.

The UE 100 (control unit 120) starts or restarts the BWP switching timer based on switching from the PDCCH skipping state to the PDCCH monitoring execution state. UE 100 (control unit 120) starts or restarts the BWP switching timer based on the expiration of the skipping period timer. In FIG. 15, at time t23, the skipping period timer expires, and UE 100 (control unit 120) starts or restarts the BWP switching timer.

As a result, when the UE 100 (control unit 120) is in the PDCCH skipping state, the BWP switching timer does not expire because the BWP switching timer is stopped. As a result, the UE 100 (control unit 120) does not switch the BWP based on the expiration of the BWP switching timer during execution of PDCCH monitoring adaptation. As a result, for example, even when the UE 100 switches the PDCCH monitoring state so that the switching process of the PDCCH monitoring state differs for each BWP, the UE 100 can appropriately switch the PDCCH monitoring state.

(7.3) Third Operation Example A third operation example of the mobile communication system 1 will be described with reference to FIG. Note that differences from the above description will be mainly described. In the third operation example, the UE 100 (control unit 120) switches the PDCCH monitoring state to the PDCCH monitoring execution state in the special cell when the BWP switching timer expires in all the secondary cells.

In this operation example, the UE 100 is configured with a special cell and one or more secondary cells by the base station 200 . The UE 100 is performing radio communication with the base station 200 (and other base stations 200) by carrier aggregation or dual connectivity with the set special cell and secondary cell.

The BWP in the special cell may be the default BWP set as the default BWP by the base station 200, or may be the initial BWP.

The base station 200 (transmitting unit 211) transmits switching control information to the UE 100. UE 100 (receiving unit 112) receives the switching control information.

The switching control information may include BWP switching timer information for setting a BWP switching timer (eg, BWP inactivity timer) associated with each secondary cell. UE 100 manages a BWP switching timer associated with each secondary cell.

Also, the switching control information may include SSSG setting information for setting the SSSG for monitoring the PDCCH in the default BWP or the initial BWP. The SSSG configuration information may be applied when the BWP switching timer expires in all secondary cells.

In step S301, the UE 100 (control unit 120) determines whether or not the BWP switching timer has expired in the secondary cell set in the UE 100. UE 100 (control unit 120) may determine whether or not all BWP switching timers associated with any secondary cell among the secondary cells configured in UE 100 have expired. UE 100 (control unit 120) executes the process of step S302 when the BWP switching timer expires in the secondary cell. On the other hand, when the BWP switching timer has not expired in the secondary cell, the UE 100 (control unit 120) executes the process of step S301.

In step S302, the UE 100 (control unit 120) determines whether or not the BWP switching timers have expired in all the secondary cells set in the UE 100. Therefore, UE 100 (control unit 120) may determine whether or not all BWP switching timers associated with each secondary cell have expired. The UE 100 (control unit 120) executes the process of step S303 when the BWP switching timers expire in all secondary cells. On the other hand, UE 100 (control unit 120) executes the process of step S301 when the BWP switching timer has not expired in at least one of the one or more secondary cells configured in UE 100.

In step S303, the UE 100 (control unit 120) determines whether or not the special cell is in the PDCCH skipping state. UE 100 (control unit 120) executes the process of step S304 when the special cell is in the PDCCH skipping state. UE 100 (control unit 120) may terminate the process if the special cell is not in the PDCCH skipping state.

Note that UE 100 (control unit 120) may determine whether or not PDCCH monitoring adaptation is being executed in a special cell. UE 100 (control unit 120) may perform the process of step S304 when PDCCH monitoring adaptation is being performed in a special cell. UE 100 (control unit 120) may end the process when PDCCH monitoring adaptation is not being executed in the special cell.

Further, UE 100 (control unit 120), in a special cell, PDCCH monitoring state, among a plurality of SSSGs having different search space cycles, when the SSSG search space cycle is a predetermined value or more is applied. , the process of step S304 may be executed. The UE 100 (control unit 120) may end the process when SSSG with a search space period less than a predetermined value is applied.

In step S304, the UE 100 (control unit 120) switches the PDCCH monitoring state to the PDCCH monitoring execution state. The UE 100 (control unit 120) may switch the PDCCH monitoring state to a PDCCH monitoring execution state in which SSSG with a search space period less than a predetermined value is applied. The UE 100 (control unit 120) may switch the PDCCH monitoring state to a state of monitoring the PDCCH using the SSSG set for PDCCH monitoring in the special cell configured in the UE 100. The SSSG used to perform PDCCH monitoring may be the SSSG configured for the special cell (downlink BWP in the special cell).

The UE 100 (control unit 120) can switch the PDCCH monitoring state to the PDCCH monitoring execution state based on the switching control information. UE 100 (control unit 120) may monitor PDCCH based on SSSG set by switching control information in default BWP or initial BWP. Note that UE 100 (control section 120) may monitor PDCCH in non-default BWP.

As described above, the UE 100 (control unit 120) cannot monitor the PDCCH in the secondary cells when the BWP switching timer in the secondary cells expires and the BWPs in all the secondary cells are deactivated. However, if the special cell is not in the PDCCH skipping state, the UE 100 can monitor the PDCCH, so even if the BWP in all secondary cells is deactivated, the base station 200 can control the UE 100. .

(7.4) Fourth Operation Example A fourth operation example of the mobile communication system 1 will be described with reference to FIGS. 17 and 18. FIG. Note that differences from the above description will be mainly described. In the fourth operation example, when the predetermined BWP is deactivated, the UE 100 (control unit 120) suspends the switching setting for the predetermined BWP based on the switching control information.

In this operation example, PDCCH monitoring state switching processing (specifically, PDCCH monitoring adaptation) is set for each BWP in the UE 100 . Therefore, based on the switching control information from the base station 200, the UE 100 performs switching settings (specifically, PDCCH monitoring adaptation settings) for each of one or a plurality of BWPs.

In step S401, the UE 100 (control unit 120) activates a predetermined BWP.

In step S402, the UE 100 (control unit 120) controls PDCCH monitoring state switching processing (specifically, PDCCH monitoring adaptation) using switching settings for a predetermined BWP.

At step 403, the UE 100 (control unit 120) determines whether or not the predetermined BWP has been deactivated. The UE 100 (control unit 120) performs the process of step S404 when the predetermined BWP is deactivated (that is, the predetermined BWP is an inactive BWP). On the other hand, the UE 100 (control unit 120) performs the process of step S402 when the predetermined BWP is not deactivated (that is, the predetermined BWP is the active BWP).

In step S404, the UE 100 (control unit 120) suspends the switching setting for the predetermined BWP. The UE 100 (control unit 120) may suspend the value of the predetermined BWP parameter set by the switching control information included in the RRC message. The UE 100 (control unit 120) may hold the values of the parameters for the predetermined BWP without discarding (or clearing) them.

Therefore, when the predetermined BWP is activated, the UE 100 (control unit 120) uses the switching setting for the predetermined BWP based on the switching control information to control the switching process in the predetermined BWP. On the other hand, the UE 100 (control unit 120) suspends the switching setting for the predetermined BWP when the predetermined BWP is deactivated.

Next, an operation example when the UE 100 (control unit 120) suspends the switching setting for the predetermined BWP will be described using FIG.

Step S411 is the same as step S404.

In step S412, the UE 100 (control unit 120) determines whether or not the predetermined BWP has been activated again after the predetermined BWP has been deactivated. The UE 100 (control unit 120) executes the process of step S413 when the predetermined BWP is activated again. On the other hand, the UE 100 (control unit 120) executes the process of step S412 when the predetermined BWP is not activated again (that is, the predetermined BWP is an inactive BWP).

In step S413, the UE 100 (control unit 120) restores the suspended switching settings. The UE 100 (control unit 120) may reinitialize the suspended switching setting.

In step S414, the UE 100 (control unit 120) uses the restored switching settings to control switching processing in a predetermined BWP.

As described above, when the predetermined BWP is deactivated, the UE 100 suspends the switching setting for the predetermined BWP, thereby speeding up the start of control of the switching process in the predetermined BWP as compared with the case of discarding the switching setting. be able to.

(7.5) Fifth Operation Example A fifth operation example of the mobile communication system 1 will be described with reference to FIG. Note that differences from the above description will be mainly described. In the fifth operation example, the UE 100 (control unit 120) discards the suspended switching setting.

The UE 100 (control unit 120) suspends the switching setting, as in the fourth operation example. Note that the UE 100 (control unit 120) may perform the operation of the fourth operation example together with the operation of this operation example.

Step S421 is the same as step S404.

In step S422, the UE 100 (control unit 120) determines whether or not the predetermined BWP is the BWP of the secondary cell. The UE 100 (control unit 120) executes the process of step S423 when the predetermined BWP is the BWP of the secondary cell. On the other hand, if the predetermined BWP is not the BWP of the secondary cell (specifically, the predetermined BWP is the BWP of the special cell), the UE 100 (control unit 120) may end the processing of this operation example.

In step S423, the UE 100 (control unit 120) determines whether or not the secondary cell deactivation timer (specifically, sCellDeactivationTimer) of the predetermined BWP has expired. The UE 100 (control unit 120) executes the process of step S424 when the deactivation timer of the secondary cell of the predetermined BWP has expired. On the other hand, UE 100 (control unit 120) executes the process of step S423 when the deactivation timer of the secondary cell of the predetermined BWP has not expired (that is, the deactivation timer is in operation or stopped). do.

The deactivation timer (sCellDeactivationTimer) is used to determine whether to deactivate the secondary cell associated with the timer. UE 100 (control unit 120) deactivates the secondary cell associated with the timer based on the expiration of the deactivation timer.

Note that the set value (timer value) for setting the deactivation timer is included in the serving cell configuration (ServingCellConfig). If the field for setting the deactivation timer in the serving cell setting is blank (absent), the UE 100 (control unit 120) may apply an infinite value as the timer value of the deactivation timer.

In step S424, the UE 100 (control unit 120) deactivates the secondary cell.

In step S425, the UE 100 (control unit 120) stops the BWP switching timer associated with the predetermined BWP.

In step S426, the UE 100 (control unit 120) discards the switching setting for the predetermined BWP. The UE 100 (control unit 120) may clear the switching setting for the predetermined BWP.

As described above, UE 100, when the secondary cell is deactivated based on the expiration of the timer for deactivating the secondary cell, by clearing the switch setting set for the secondary cell, UE 100 ( The processing load on the control unit 120) can be reduced.

(8) Other Embodiments In the second operation example (see FIG. 14) described above, the control unit 120 starts or restarts the BWP switching timer based on the switching instruction DCI. However, it is not limited to this. The control unit 120 may start or restart the BWP switching timer based on expiration of the skipping period timer.

In the above-described embodiment, the BWP switching timer is an inactivity timer (inactivity-timer), but it is not limited to this. The BWP switching timer may be another timer.

The operation sequences (and operation flows) in the above-described embodiments do not necessarily have to be executed in chronological order according to the order described in the flow diagrams or sequence diagrams. For example, the steps in the operations may be performed out of order or in parallel with the order illustrated in the flow diagrams or sequence diagrams. Also, some steps in the operation may be omitted and additional steps may be added to the process. Further, the operation sequences (and operation flows) in the above-described embodiments may be implemented independently, or two or more operation sequences (and operation flows) may be combined and implemented. For example, some steps of one operation flow may be added to another operation flow, or some steps of one operation flow may be replaced with some steps of another operation flow.

In the above-described embodiment, the base station 200 may include multiple units. The plurality of units may include a first unit hosting a higher layer included in the protocol stack and a second unit hosting a lower layer included in the protocol stack. The upper layers may include the RRC layer, the SDAP layer and the PDCP layer, and the lower layers may include the RLC layer, the MAC layer and the PHY layer. The first unit may be a CU (central unit), and the second unit may be a DU (Distributed Unit). The plurality of units may include a third unit that performs processing below the PHY layer. The second unit may perform processing above the PHY layer. The third unit may be an RU (Radio Unit). Base station 200 may be one of a plurality of units, and may be connected to other units of the plurality of units. Also, the base station 200 may be an IAB (Integrated Access and Backhaul) donor or an IAB node.

In the above-described embodiment, the mobile communication system 1 based on NR has been described as an example. However, the mobile communication system 1 is not limited to this example. The mobile communication system 1 may be a TS-compliant system of either LTE (Long Term Evolution) or another generation system (for example, 6th generation) of the 3GPP standards. Base station 200 may be an eNB that provides E-UTRA user plane and control plane protocol termination towards UE 100 in LTE. The mobile communication system 1 may be a system conforming to a TS of a standard other than the 3GPP standard.

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

In the above embodiments, "transmit" may mean performing at least one layer of processing in the protocol stack used for transmission, or physically transmitting the signal wirelessly or by wire. It may mean sending to Alternatively, "transmitting" may mean a combination of performing the at least one layer of processing and physically transmitting the signal wirelessly or by wire. Similarly, "receive" may mean performing processing of at least one layer in the protocol stack used for reception, or physically receiving a signal wirelessly or by wire. may mean that Alternatively, "receiving" may mean a combination of performing the at least one layer of processing and physically receiving the signal wirelessly or by wire. Similarly, "obtain/acquire" may mean obtaining information among stored information, and may mean obtaining information among information received from other nodes. Alternatively, it may mean obtaining the information by generating the information. Similarly, references to "based on" and "depending on/in response to" are used unless otherwise specified. does not mean The phrase "based on" means both "based only on" and "based at least in part on." Similarly, the phrase "depending on" means both "only depending on" and "at least partially depending on." Similarly, "include" and "comprise" are not meant to include only the recited items, and may include only the recited items or in addition to the recited items. Means that it may contain further items. Similarly, in the present disclosure, "or" does not mean exclusive OR, but means logical OR. Furthermore, any references to elements using the "first," "second," etc. designations used in this disclosure do not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, reference to a first and second element does not imply that only two elements can be employed therein or that the first element must precede the second element in any way. In this disclosure, when articles are added by translation, such as a, an, and the in English, these articles are used in plural unless the context clearly indicates otherwise. shall include things.

Although the present disclosure has been described with reference to examples, it is understood that the present disclosure is not limited to those examples or structures. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and configurations, as well as other combinations and configurations, including single elements, more, or less, are within the scope and spirit of this disclosure.

(Appendix)
Features related to the above-described embodiments are added.

(Appendix 1)
A communication device (100) that performs wireless communication in a bandwidth portion that is a portion of the total bandwidth of a cell of a base station (200),
Based on the expiration of the BWP switching timer for switching the bandwidth portion, the bandwidth portion is switched and the PDCCH monitoring state regarding the monitoring of the physical downlink control channel (PDCCH) is switched BWP timer-based switching processing. (120) and
a receiving unit (112) for receiving a radio resource control (RRC) message including switching control information for controlling the BWP timer-triggered switching process;
The communication device (100), wherein the control unit (120) controls the switching process caused by the BWP timer based on the switching control information.

(Appendix 2)
The switching control information is information regarding whether to enable execution of the switching process caused by the BWP timer,
The communication device (100) according to appendix 1, wherein the control unit (120) performs the switching process caused by the BWP timer based on the switching control information indicating that execution of the switching process caused by the BWP timer is enabled. .

(Appendix 3)
3. The communication device (100) according to appendix 1 or 2, wherein the switching control information is included in a PDCCH setting for setting a PDCCH parameter unique to the communication device (100).

(Appendix 4)
3. According to Appendix 1 or 2, the switching control information includes information for setting a search space set group (SSSG) for monitoring the PDCCH in the bandwidth portion after switching based on expiration of the BWP switching timer. communication device (100).

(Appendix 5)
The receiving unit (112) receives from the base station (200) an instruction for switching to a PDCCH skipping state in which monitoring of the PDCCH is skipped as the PDCCH monitoring state,
The communication device (100) according to claim 1 or 2, wherein the control unit (120) stops the BWP switching timer based on switching to the PDCCH skipping state according to the instruction.

(Appendix 6)
The communication device (100) according to appendix 5, wherein the control unit (120) starts or restarts the BWP switching timer based on switching from the PDCCH skipping state to the PDCCH monitoring state.

(Appendix 7)
When the BWP switching timer expires in all the secondary cells set in the communication device (100), the control unit (120) controls the PDCCH monitoring state in the special cell set in the communication device (100). to a state of monitoring the PDCCH.

(Appendix 8)
The bandwidth portion in the special cell is a default bandwidth portion or an initial bandwidth portion set as a default by the base station (200),
The communication device (100) according to appendix 7, wherein the control unit (120) monitors the PDCCH in the default bandwidth portion or the initial bandwidth portion based on the switching control information.

(Appendix 9)
The switching control information includes information for setting a search space set group (SSSG) for monitoring the PDCCH in the default bandwidth portion or the initial bandwidth portion,
The communication device (100) according to appendix 8, wherein the control unit (120) monitors the PDCCH based on the SSSG set by the switching control information in the default bandwidth portion or the initial bandwidth portion.

(Appendix 10)
A communication device (100) that performs wireless communication in a bandwidth portion that is a portion of the total bandwidth of a cell of a base station (200),
A control unit (a control unit ( 120) and
a receiving unit (112) for receiving a radio resource control (RRC) message including switching control information for controlling the switching process;
The control unit (120)
controlling the switching process in the predetermined bandwidth portion using switching settings for the predetermined bandwidth portion based on the switching control information when the predetermined bandwidth portion is activated;
A communication device (100) that suspends the switching setting when the predetermined bandwidth portion is deactivated.

(Appendix 11)
The control unit (120) restores the suspended switching settings when the predetermined bandwidth portion is deactivated and then activated again, and uses the restored switching settings to 11. The communication device (100) according to appendix 10, which controls the switching process.

(Appendix 12)
the predetermined bandwidth portion is a portion of the total bandwidth of a secondary cell;
The control unit (120) discards the suspended switching setting when the secondary cell is deactivated based on the expiration of the timer for deactivating the secondary cell. A communication device (100) as described.

(Appendix 13)
A base station (200) that performs wireless communication with a communication device (100) in a bandwidth portion that is a portion of the total bandwidth of a cell of the base station (200),
a control unit (230) that generates a radio resource control (RRC) message including switching control information for controlling a BWP timer-based switching process in the communication device (100);
a transmission unit (211) for transmitting the RRC message to the communication device (100);
In the BWP timer-based switching process, the communication device (100) switches the bandwidth portion based on expiration of a BWP switching timer for switching the bandwidth portion, and switches the physical downlink control channel (PDCCH). A base station (200) to switch the PDCCH monitoring state for monitoring.

(Appendix 14)
A communication method performed by a communication device (100) that performs wireless communication in a bandwidth portion that is a portion of the total bandwidth of a cell of a base station (200),
switching the bandwidth portion based on expiration of a BWP switching timer for switching the bandwidth portion, and performing a BWP timer-triggered switching process for switching a PDCCH monitoring state for monitoring a physical downlink control channel (PDCCH); ,
receiving a radio resource control (RRC) message containing switching control information for controlling the BWP timer triggered switching process;
The communication method, wherein, in the step of performing the switching process caused by the BWP timer, the switching process caused by the BWP timer is controlled based on the switching control information.

(Appendix 15)
A communication method performed by a communication device (100) that performs wireless communication in a bandwidth portion that is a portion of the total bandwidth of a cell of a base station (200),
a step of controlling a switching process for switching a PDCCH monitoring state related to monitoring of a physical downlink control channel (PDCCH) in a predetermined bandwidth portion among one or more bandwidth portions set in the communication device (100);
receiving a Radio Resource Control (RRC) message containing switching control information for controlling the switching process;
In the step of controlling the switching process, if the predetermined bandwidth portion is activated, using a switching setting for the predetermined bandwidth portion based on the switching control information, controlling the switching process;
The communication method, further comprising suspending the switching setting when the predetermined bandwidth portion is deactivated.

Claims (15)

1. A communication device (100) that performs wireless communication in a bandwidth portion that is a portion of the total bandwidth of a cell of a base station (200),
   Based on the expiration of the BWP switching timer for switching the bandwidth portion, the bandwidth portion is switched and the PDCCH monitoring state regarding the monitoring of the physical downlink control channel (PDCCH) is switched BWP timer-based switching processing. (120) and
   a receiving unit (112) for receiving a radio resource control (RRC) message including switching control information for controlling the BWP timer-triggered switching process;
   The communication device (100), wherein the control unit (120) controls the switching process caused by the BWP timer based on the switching control information.
2. The switching control information is information regarding whether to enable execution of the switching process caused by the BWP timer,
   The communication device (100) according to Claim 1, wherein the control unit (120) performs the switching process caused by the BWP timer based on the switching control information indicating that execution of the switching process caused by the BWP timer is enabled. ).
3. The communication device (100) according to claim 1 or 2, wherein the switching control information is included in PDCCH settings for setting PDCCH parameters unique to the communication device (100).
4. 3. The switching control information includes information for setting a search space set group (SSSG) for monitoring the PDCCH in the bandwidth portion after switching based on expiration of the BWP switching timer. A communication device (100) as described.
5. The receiving unit (112) receives from the base station (200) an instruction for switching to a PDCCH skipping state in which monitoring of the PDCCH is skipped as the PDCCH monitoring state,
   The communication device (100) according to claim 1 or 2, wherein the control unit (120) stops the BWP switching timer based on switching to the PDCCH skipping state according to the instruction.
6. The communication device (100) according to claim 5, wherein the control unit (120) starts or restarts the BWP switching timer based on switching from the PDCCH skipping state to the PDCCH monitoring state.
7. When the BWP switching timer expires in all the secondary cells set in the communication device (100), the control unit (120) controls the PDCCH monitoring state in the special cell set in the communication device (100). to a state of monitoring the PDCCH.
8. The bandwidth portion in the special cell is a default bandwidth portion or an initial bandwidth portion set as a default by the base station (200),
   The communication device (100) according to claim 7, wherein the controller (120) monitors the PDCCH in the default bandwidth portion or the initial bandwidth portion based on the switching control information.
9. The switching control information includes information for setting a search space set group (SSSG) for monitoring the PDCCH in the default bandwidth portion or the initial bandwidth portion,
   The communication device (100) according to claim 8, wherein the control unit (120) monitors the PDCCH based on the SSSG set by the switching control information in the default bandwidth portion or the initial bandwidth portion.
10. A communication device (100) that performs wireless communication in a bandwidth portion that is a portion of the total bandwidth of a cell of a base station (200),
    A control unit (a control unit ( 120) and
    a receiving unit (112) for receiving a radio resource control (RRC) message including switching control information for controlling the switching process;
    The control unit (120)
    controlling the switching process in the predetermined bandwidth portion using switching settings for the predetermined bandwidth portion based on the switching control information when the predetermined bandwidth portion is activated;
    A communication device (100) that suspends the switching setting when the predetermined bandwidth portion is deactivated.
11. The control unit (120) restores the suspended switching settings when the predetermined bandwidth portion is deactivated and then activated again, and uses the restored switching settings to The communication device (100) according to claim 10, for controlling the switching process.
12. the predetermined bandwidth portion is a portion of the total bandwidth of a secondary cell;
    12. The control unit (120) discards the suspended switching configuration when the secondary cell is deactivated based on expiration of a timer for deactivating the secondary cell. A communication device (100) according to claim 1.
13. A base station (200) that performs wireless communication with a communication device (100) in a bandwidth portion that is a portion of the total bandwidth of a cell of the base station (200),
    a control unit (230) that generates a radio resource control (RRC) message including switching control information for controlling a BWP timer-based switching process in the communication device (100);
    a transmission unit (211) for transmitting the RRC message to the communication device (100);
    In the BWP timer-based switching process, the communication device (100) switches the bandwidth portion based on expiration of a BWP switching timer for switching the bandwidth portion, and switches the physical downlink control channel (PDCCH). A base station (200) to switch the PDCCH monitoring state for monitoring.
14. A communication method performed by a communication device (100) that performs wireless communication in a bandwidth portion that is a portion of the total bandwidth of a cell of a base station (200),
    switching the bandwidth portion based on expiration of a BWP switching timer for switching the bandwidth portion, and performing a BWP timer-triggered switching process for switching a PDCCH monitoring state for monitoring a physical downlink control channel (PDCCH); ,
    receiving a radio resource control (RRC) message containing switching control information for controlling the BWP timer triggered switching process;
    The communication method, wherein, in the step of performing the switching process caused by the BWP timer, the switching process caused by the BWP timer is controlled based on the switching control information.
15. A communication method performed by a communication device (100) that performs wireless communication in a bandwidth portion that is a portion of the total bandwidth of a cell of a base station (200),
    a step of controlling a switching process for switching a PDCCH monitoring state related to monitoring of a physical downlink control channel (PDCCH) in a predetermined bandwidth portion among one or more bandwidth portions set in the communication device (100);
    receiving a Radio Resource Control (RRC) message containing switching control information for controlling the switching process;
    In the step of controlling the switching process, if the predetermined bandwidth portion is activated, using a switching setting for the predetermined bandwidth portion based on the switching control information, controlling the switching process;
    The communication method, further comprising suspending the switching setting when the predetermined bandwidth portion is deactivated.
    

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