Wireless terminal, base station, and methods thereof

Abstract

This contributes to quickly deactivating the radio resource range used for transmitting downlink control information or the reception operation of the radio terminal therein. In one embodiment, a wireless terminal (2) receives a first information element via a dedicated signaling message addressed to the wireless terminal (2), the first information element indicating a list of search spaces configured for the wireless terminal (2) by a base station (1). The first information element includes a second information element indicating the configuration of each search space required for the wireless terminal (2) to monitor downlink control information in each search space included in the list. The first information element further includes a third information element indicating, for each search space, whether each search space is initially deactivated.

Description

[Technical field]

[0001] TECHNICAL FIELD This disclosure relates to wireless communication systems and to the transmission of downlink control information from base stations to wireless terminals. [Background technology]

[0002] A base station (e.g., Long Term Evolution (LTE) eNB or NR gNB) transmits Downlink Control Information (DCI) to a wireless terminal (e.g., User Equipment (UE) or NR UE) on a physical layer downlink control channel (e.g., Physical Downlink Control Channel (PDCCH)). DCI is used for various purposes, and therefore various DCI formats are defined. One of the main purposes of DCI is to inform wireless terminals of Physical Uplink Shared Channel (PUSCH) scheduling and Physical Downlink Shared Channel (PDSCH) scheduling (i.e., resource allocation). Besides this, DCI is used, for example, for transmitting transmission power control.

[0003] A wireless terminal must try to decode each PDCCH candidate within a predefined (or base station configured) resource range (i.e., Control Channel Element (CCE) locations, CCE resources) to find a PDCCH that contains DCI addressed to the wireless terminal (hereafter, PDCCH / DCI). Specifically, the UE must check all possible PDCCH locations, PDCCH formats, and DCI formats. Such an operation is called blind decoding.

[0004] The locations where PDCCH / DCI may be transmitted depend on the PDCCH format (eg, the number of CCEs aggregated for PDCCH transmission (ie, aggregation level)). Each location where PDCCH / DCI may be transmitted is called a PDCCH candidate. A set of PDCCH candidates that a UE should monitor is called PDCCH search spaces or simply search spaces. A search space is a set of PDCCH candidates for a certain PDCCH format. There are two types of search spaces, called UE-specific search space (USS) and Common Search Space (CSS). The UE-specific search space is individually configured for each UE through a dedicated signaling message (eg, Radio Resource Control (RRC) message). Therefore, the UE needs to complete an RRC connection establishment to obtain information about the UE-specific search space. Meanwhile, all UEs know the extent or range of the Common Search Space. Every UE knows the Common Search Space in which it should attempt blind decoding, either through predefined rules, information that every UE can receive (i.e., Master Information Block (MIB)), or UE-specific signaling messages. The Common Search Space is used, for example, to broadcast system information, paging, and random access channel (RACH) responses.

[0005] It is known that a UE needs to continuously perform many blind decoding attempts during communication, which consumes a lot of power. Usually, most of this power consumption is spent on decoding PDCCHs that are not addressed to the UE. To address this issue, power saving schemes by reducing PDCCH monitoring and blind decoding have been proposed (see Non-Patent Documents 1-7). The proposed schemes include, but are not limited to, Triggering of PDCCH monitoring, PDCCH skipping, Multiple CORESET / search space configurations, and UE assistance information / feedback for the power saving schemes. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] MediaTek Inc., “Adaptation Designs for NR UE Power Saving”, R1-1900192, 3GPP TSG RAN WG1 Ad-Hoc Meeting 1901, Taipei, Taiwan, 21st-25th January, 2019 [Non-Patent Document 2] OPPO, “UE Adaptation to the Traffic and UE Power Consumption”, R1-1900305, 3GPP TSG RAN WG1 Ad-Hoc Meeting 1901, Taipei, Taiwan, 21st-25th January, 2019 [Non-Patent Document 3] CMCC, “Discussion on UE power saving schemes with adaptation to UE traffic”, R1-1900421, 3GPP TSG RAN WG1 Ad-Hoc Meeting 1901, Taipei, Taiwan, 21st-25th January, 2019 [Non-Patent Document 4] InterDigital, Inc., “On Power Saving Techniques”, R1-1900813, 3GPP TSG RAN WG1 Ad-Hoc Meeting 1901, Taipei, Taiwan, 21st-25th January, 2019 [Non-Patent Document 5] Qualcomm Incorporated, “UE Adaptation to the Traffic and UE Power Consumption Characteristics”, R1-1900911, 3GPP TSG RAN WG1 Ad-Hoc Meeting 1901, Taipei, Taiwan, 21st-25th January, 2019 [Non-Patent Document 6] Samsung, “On UE adaptation Schemes”, R1-1901087, 3GPP TSG RAN WG1 Ad-Hoc Meeting 1901, Taipei, Taiwan, 21st-25th January, 2019 [Non-Patent Document 7] 3GPP TR 38.840 V0.1.0 (2018-11) “3rd Generation Partnership Project; Technical Specification Group Radio Access Network;NR; Study on UE Power Saving (Release 16)”, November 2018 Summary of the Invention [Problem to be solved by the invention]

[0007] In the current 3GPP (registered trademark) specifications, when a wireless terminal is (semi-statically) configured with search spaces via an RRC signaling message, the UE must attempt PDCCH monitoring in each configured search space. In other words, each search space configured in the UE is initially activated so that the UE can attempt PDCCH monitoring therein. Thus, for example, in the power saving proposal mentioned above, the wireless terminal must perform PDCCH monitoring in a particular search space until it receives signaling (e.g., power saving signal or go-to-sleep signaling) indicating skipping PDCCH monitoring in the particular search space (or deactivation of the particular search space). However, in order to reduce power consumption required for PDCCH monitoring, it is preferable that a search space that the wireless terminal does not need to receive is promptly deactivated.

[0008] One of the objectives to be achieved by the embodiments disclosed in this specification is to provide an apparatus, method, and program that contribute to quickly deactivating a radio resource range (e.g., search space, control resource set (CORSET), CCEs, or resource element groups (REGs)) used for transmitting downlink control information or a reception operation of a wireless terminal therein. It should be noted that this objective is merely one of multiple objectives to be achieved by multiple embodiments disclosed in this specification. Other objectives or problems and novel features will become apparent from the description of this specification or the accompanying drawings. [Means for solving the problem]

[0009] In a first aspect, a wireless terminal includes at least one memory and at least one processor coupled to the at least one memory. The at least one processor is configured to receive, via an individual signaling message addressed to the wireless terminal, a first information element indicating a list of search spaces configured by a base station for the wireless terminal. The first information element includes a second information element indicating a configuration of each search space required for the wireless terminal to monitor downlink control information in each search space included in the list. The first information element further includes a third information element indicating, on a per-search space basis, whether each search space is initially deactivated.

[0010] In a second aspect, a base station includes at least one memory and at least one processor coupled to the at least one memory. The at least one processor is configured to transmit a first information element indicating a list of search spaces configured by the base station for the wireless terminal to the wireless terminal via an individual signaling message addressed to the wireless terminal. The first information element includes a second information element indicating a configuration of each search space required for the wireless terminal to monitor downlink control information in each search space included in the list. The first information element further includes a third information element indicating whether each search space is initially deactivated on a per-search space basis.

[0011] In a third aspect, a method for a wireless terminal includes receiving, via a dedicated signaling message for the wireless terminal, a first information element indicating a list of search spaces configured by a base station for the wireless terminal, the first information element including a second information element indicating a configuration of each search space required for the wireless terminal to monitor downlink control information in each search space included in the list, the first information element further including a third information element indicating, on a per-search space basis, whether each search space is initially deactivated.

[0012] In a fourth aspect, a method for a base station includes transmitting a first information element to a wireless terminal via a dedicated signaling message for the wireless terminal, the first information element indicating a list of search spaces configured by the base station for the wireless terminal, the first information element including a second information element indicating a configuration of each search space required for the wireless terminal to monitor downlink control information in each search space included in the list, the first information element further including a third information element indicating, on a per-search space basis, whether each search space is initially deactivated.

[0013] In a fifth aspect, a program includes a set of instructions (software code) for causing a computer to carry out the method according to the third or fourth aspect above when the program is loaded into the computer. Effect of the Invention

[0014] According to the above-described aspects, it is possible to provide an apparatus, a method, and a program that contribute to promptly deactivating a radio resource range (e.g., search space, control resource set (CORSET), CCEs, or resource element groups (REGs)) used for transmitting downlink control information or a receiving operation of a wireless terminal therein. [Brief description of the drawings]

[0015] [Figure 1] 1 is a diagram illustrating an example of the configuration of a wireless communication network according to an embodiment. [Diagram 2] FIG. 4 is a sequence diagram showing an example of the operation of a base station and a wireless terminal according to the first embodiment. [Diagram 3] 5 is a flowchart showing an example of an operation of the base station according to the first embodiment. [Figure 4] 5 is a flowchart showing an example of an operation of the wireless terminal according to the first embodiment. [Diagram 5] A figure showing an example of the format of a Search Space information element transmitted in an RRC signaling message. [Figure 6A] A figure showing an example of the format of a Medium Access Control (MAC) Control Element (CE) for activating / deactivating a search space. [Figure 6B] A figure showing an example of a MAC CE format for activating / deactivating a search space. [Figure 6C] A figure showing an example of a MAC CE format for activating / deactivating a search space. [Figure 7] FIG. 2 is a block diagram illustrating an example configuration of a base station according to some embodiments. [Figure 8] FIG. 2 is a block diagram illustrating an example configuration of a wireless terminal according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] In the following, specific embodiments will be described in detail with reference to the drawings. In each drawing, the same or corresponding elements are denoted by the same reference numerals, and duplicated descriptions will be omitted as necessary for clarity of explanation.

[0017] The multiple embodiments described below can be implemented independently or in appropriate combination. These multiple embodiments have different novel features. Therefore, these multiple embodiments contribute to solving different objects or problems and provide different effects.

[0018] The following embodiments are described mainly for the 3GPP 5th generation mobile communication system (5G system). However, these embodiments may be applied to other wireless communication systems such as, for example, an LTE system or an LTE-Advanced system.

[0019] <First embodiment> Fig. 1 shows a configuration example of a wireless communication network according to some embodiments including the present embodiment. In the example of Fig. 1, the wireless communication network includes a base station (i.e., gNB) 1 and a wireless terminal (i.e., UE) 2. The gNB 1 is deployed in a Radio Access Network (RAN) (i.e., NG-RAN). The gNB 1 may include a gNB Central Unit (gNB-CU) and one or more gNB Distributed Units (gNB-DU) in a cloud RAN (C-RAN) deployment.

[0020] The UE2 is connected to the gNB1 via the air interface 101. The UE2 may perform carrier aggregation (CA). Specifically, the UE2 may simultaneously connect to multiple serving cells provided by the gNB1. The multiple serving cells include a primary cell (PCell) and one or more secondary cells (SCells). The UE2 communicates with the gNB1 using CA between the PCell and one or more SCells. In this case, the gNB1 may set search spaces and activate / deactivate them so that the UE2 can synchronize PDCCH monitoring between cells. That is, in one example, but not limited to this, the UE2 may perform PDCCH monitoring in multiple cells at the same time (period). Also, the UE2 may monitor PDCCHs for multiple cells in one cell, and in one example, but not limited to this, the UE2 may perform PDCCH monitoring of multiple cells in the same search space at the same time (period) (cross carrier scheduling).

[0021] Furthermore, the UE2 may be simultaneously connected to multiple base stations (i.e., Master gNB (MgNB) and Secondary gNB (SgNB)) for dual connectivity. In this case, the gNB1 in FIG. 1 may be an MgNB or an SgNB. The gNB1 operating as an MgNB provides the UE2 with a Master Cell Group (MCG) including a PCell and one or more SCells. Meanwhile, the gNB1 operating as an SgNB provides the UE2 with a Secondary Cell Group (SCG) including a Primary SCG Cell (PSCell) and one or more SCells. The PCell of the MCG and the PSCell of the SCG are also called Special Cells (SpCells). For example, when synchronization is established between cell groups (e.g., between the MCG and the SCG), the MgNB and the SgNB may share the configuration and state (i.e., activation or deactivation) of the search spaces of the MCG and the SCG with each other. The MgNB and SgNB may set search spaces and activate / deactivate them so that the UE 2 can synchronize PDCCH monitoring between cell groups. That is, in one example, but not limited to this, the UE 2 may perform PDCCH monitoring in multiple cells of multiple cell groups at the same time (period).

[0022] The DC may be a Multi-Radio Dual Connectivity (MR-DC). The MR-DC includes an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (E-UTRA)-NR Dual Connectivity (EN-DC), an NR-E-UTRA DC (NE-DC), an NG-RAN EN-DC (NGEN-DC), and an NR-NR DC (NR DC). In these cases, the gNB1 in FIG. 1 may be an LTE eNB or an LTE eNB (Next generation (ng)-eNB) that can be connected to a 5G core network (5GC).

[0023] 2 is a sequence diagram showing a process 200 as an example of the operation of the gNB1 and the UE2 according to the present embodiment. In step 201, the gNB1 transmits a dedicated signaling message to the UE2. The dedicated signaling message is transmitted specifically or dedicatedly to the UE2. In the case of a 5G system, the UE dedicated signaling message is, for example, an RRC message.

[0024] The RRC message of step 201 includes a first information element (IE) indicating a list of search spaces to be configured (i.e., added or modified) by gNB1 for UE2. The list may include one or more common search spaces or one or more UE-specific search spaces. The first information element includes a second information element indicating the configuration of each search space required for UE2 to monitor a PDCCH containing DCI (i.e., PDCCH / DCI) in each search space included in the list.

[0025] The second information element may, for example, indicate an identifier of each search space. The second information element may further include at least one of an information element indicating a resource location of each search space, an information element indicating a type of each search space, an information element indicating a type of downlink control information to be monitored in each search space, and an information element indicating a periodicity of each search space.

[0026] Furthermore, the second information element includes a third information element indicating whether each search space is initially deactivated on a per-search space basis. Alternatively, the third information element may be included in the first information element independently of the second information element.

[0027] In the case of a 5G system, the RRC message used to transmit the first information element indicating the list of search spaces configured by the gNB1 is, for example, an RRC Setup message, an RRC Reconfiguration message, or an RRC Resume message. The RRC Setup message is transmitted to establish a signaling radio bearer (i.e., Signaling Radio Bearer 1 (SRB1)) upon establishment of an RRC connection. The RRC Reconfiguration message is transmitted to instruct the UE2 to modify an already established RRC connection. The RRC Resume message is transmitted to resume a suspended RRC connection.

[0028] In the case of a 5G system, the above-mentioned first information element (IE) indicating a list of search spaces may relate to multiple search spaces configured in one downlink Bandwidth Part (BWP), while the second information element indicating the configuration of each search space and the third information element included therein may relate to each search space configured in the downlink BWP.

[0029] More specifically, the RRC Setup message and the RRC Resume message may include the MCG configuration (i.e., masterCellGroup IE). Meanwhile, the RRC Reconfiguration message may include the MCG configuration (i.e., masterCellGroup IE) or the SCG configuration (i.e., masterCellGroup IE), or both. Each of the MCG configuration and the SCG configuration may include a configuration of a respective serving cell (i.e., ServingCellConfig IE). Each of the serving cell configurations may include a configuration of dedicated (i.e., UE-specific) parameters for the downlink BWP (i.e., BWP-DownlinkDedicated IE). The dedicated configuration for the downlink BWP may include a PDCCH configuration (i.e., PDCCH-Config IE) that includes a list of search spaces to be configured (i.e., added or modified) (i.e., searchSpacesToAddModList IE). The list of search spaces is a list of Search Spaces that are specifically configured for a UE, and includes the configuration of each search space (i.e., SearchSpace IE). In the current 3GPP specifications, a network can configure 10 search spaces (including UE-specific and common Search Spaces) per BWP per cell.

[0030] In addition, the serving cell configuration for the SCell may include a configuration of common parameters for the downlink BWP (i.e., BWP-DownlinkCommon IE). The common configuration for the downlink BWP may include a PDCCH common configuration (i.e., PDCCH-ConfigCommon IE) including a list of common search spaces (i.e., commonSearchSpaceList IE). The list of common search spaces is a list of additional common search spaces, and includes the configuration of each additional common search space (i.e., SearchSpace IE).

[0031] The third information element included in the RRC message of step 201 may cause UE2 to determine for each search space whether each search space needs to be monitored to receive PDCCH / DCI. In other words, UE2 may determine for each search space whether each search space needs to be monitored to receive PDCCH / DCI based on the third information element. UE2 may not perform blind decoding for PDCCH / DCI reception in a search space in an inactive state. Meanwhile, UE2 needs to perform blind decoding for PDCCH / DCI reception in a search space in an active state.

[0032] Specifically, the third information element may prompt UE2 to determine that the search space associated with the third information element does not need to be monitored to receive PDCCH / DCI if the third information element indicates deactivation. On the other hand, the third information element may prompt UE2 to determine that the search space associated with the third information element does not need to be monitored to receive PDCCH / DCI if the third information element does not indicate deactivation. Thus, UE2 may determine that the search space associated with the third information element does not need to be monitored to receive PDCCH / DCI if the third information element indicates deactivation. On the other hand, UE2 may determine that the search space associated with the third information element needs to be monitored to receive PDCCH / DCI if the third information element does not indicate deactivation.

[0033] More specifically, the third information element may prompt the RRC layer of the UE2 to inform the physical layer of the UE2 that the search space associated with the third information element may not be monitored if the third information element indicates deactivation. Thus, the RRC layer of the UE2 may inform the physical layer of the UE2 that the search space associated with the third information element may not be monitored if the third information element indicates deactivation. In other words, the RRC layer of the UE2 may configure the physical layer of the UE2 not to monitor the search space associated with the third information element if the third information element indicates deactivation.

[0034] 3 is a flowchart showing an example of the operation of the gNB1 according to the present embodiment. In step 301, the gNB1 creates a list of search spaces to be configured in the UE2. The list indicates, for each search space, whether each search space is initially deactivated. In step 302, the gNB1 transmits the list of search spaces to the UE2 via an RRC message.

[0035] 4 is a flowchart showing an example of the operation of UE2 according to this embodiment. In step 401, a list of search spaces configured in UE2 is received from gNB1 via an RRC message. In step 402, UE2 determines for each configured search space whether or not it needs to be monitored to receive PDCCH / DCI.

[0036] FIG. 5 shows an example of a format of a Search Space IE transmitted in an RRC signaling message. In the example of FIG. 5, the Search Space IE includes a "toMonitor" IE (505). The toMonitor IE (505) indicates that a search space associated with the Search Space IE (configured by the Search Space IE) is initially inactivated. When the gNB1 initially deactivates the search space, the gNB1 includes the toMonitor IE (505) in the Search Space IE. If the Search Space IE includes the toMonitor IE (505), the UE2 may determine that the search space associated with the Search Space IE is initially inactivated. On the other hand, if the Search Space IE does not include the toMonitor IE (505), the UE2 may determine that the search space associated with the Search Space IE is initially activated.

[0037] Conversely, the gNB1 may include the toMonitor IE (505) in the Search Space IE when the gNB1 initially activates the search space. In this case, the UE2 may determine that the search space associated with the Search Space IE is initially inactive if the Search Space IE does not include the toMonitor IE (505).

[0038] Alternatively, the Search Space IE may specify whether the initial state of the search space is Activated or deactivated.

[0039] As shown in FIG. 5, the Search Space IE may include other information elements such as a searchSpaceId IE (501), a controlResourceSetId IE (502), a monitoringSlotPeriodicityAndOffset IE (503), and a searchSpaceType IE (504). The searchSpaceId IE (501) indicates an identifier of a search space set by this Search Space IE. The controlResourceSetId IE (502) indicates an identifier of a Control Resource Set (CORESET) applied for the search space set by this Search Space IE. The CORESET is a set of physical resources and parameters used to carry the PDCCH / DCI. The monitoringSlotPeriodicityAndOffset IE (503) indicates the slots in which PDCCH monitoring is performed by periodicity and offset. The searchSpaceType IE (504) indicates whether the search space set by this Search Space IE is a common search space or a UE specific search space, and indicates the DCI format monitored in the search space.

[0040] In one example, the gNB1 may deactivate one or more UE-specific search spaces configured for the UE2. In this case, the UE2 may receive PDCCH / DCI in the common search space.

[0041] According to this embodiment, the gNB1 transmits to the UE2 a search space configuration (i.e., a configuration required for the UE2 to monitor the PDCCH / DCI) for adding or modifying a plurality of search spaces, together with an information element (i.e., the above-mentioned third information element) indicating whether each search space is initially deactivated per search space. This allows the UE2 to consider that the search space to be configured (i.e., added or modified) is initially deactivated based on the information element. In other words, the UE2 can quickly deactivate the search space based on the information element without activating it, and can quickly deactivate the reception operation (e.g., blind decoding for PDCCH / DCI reception) in the search space. Therefore, the UE2 can operate not to perform blind decoding for PDCCH / DCI reception from the beginning in the newly configured (i.e., added or modified) search space.

[0042] <Second embodiment> This embodiment describes a modification of the first embodiment. An example of the configuration of a wireless communication network according to this embodiment is similar to that shown in FIG.

[0043] gNB1 may activate a search space that is initially in a deactivated state at any given time, as needed.

[0044] Further, gNB1 may dynamically change the activation and deactivation of one or more search spaces to adjust the frequency (or periodicity) at which UE2 monitors the PDCCH / DCI.

[0045] For example, when the gNB1 detects an increase in the frequency (or period) of scheduling for the UE2 (in other words, when the gNB1 detects that the scheduling queue is short or when the gNB1 detects that the scheduling queue has become short), the gNB1 may activate a search space that is set for the UE2 but is in an inactive state. That is, the gNB1 may transmit an indication (e.g., Layer-1 signaling or Layer-2 signaling) indicating the activation of the search space to the UE2.

[0046] Additionally or alternatively, when the gNB1 receives an explicit or implicit request from the UE2 indicating an increase in the frequency (or period) of monitoring the PDCCH / DCI, the gNB1 may activate one or more search spaces configured but inactivated for the UE2. The request from the UE2 to the gNB1 may be RRC layer signaling, MAC layer (Layer-2) signaling, or physical layer (Layer-1) signaling.

[0047] In one example, the request may be physical layer signaling, such as a scheduling request or similar Uplink Control Information (UCI). In another example, the request may be included in an information element (e.g., UEAssistanceInformation IE) included in a UE assistance information message of the RRC layer. More specifically, the request may be a delayBudgetReport IE included in the UEAssistanceInformation IE. The delayBudgetReport IE is used by the UE to inform the gNB of the UE's preference regarding connected mode discontinuous reception (DRX). Alternatively, the request may be a newly defined information element to indicate the frequency (or period) of monitoring the PDCCH / DCI. The new information element may be called, for example, a PrefPdcchPeriodReport IE and may be an ENUMERATED type variable indicating the monitoring period desired by the UE (e.g., 0 ms, 2 ms, 4 ms, 5 ms, 8 ms, 10 ms, 20 ms, or 40 ms, etc.).

[0048] Conversely, for example, when the gNB1 detects a decrease in the frequency (or period) of scheduling to the UE2 (in other words, when the gNB1 detects that the scheduling queue is long or has become long), the gNB1 may deactivate one or more search spaces in the activation state of the UE2. That is, the gNB1 may transmit an indication (e.g., Layer-1 signaling or Layer-2 signaling) indicating the deactivation of the search space to the UE2.

[0049] Additionally or alternatively, when the gNB1 receives an explicit or implicit request from the UE2 indicating a decrease in the frequency (or periodicity) of monitoring the PDCCH / DCI, the gNB1 may deactivate one or more active search spaces of the UE2. As described above with respect to an increase in the frequency (or periodicity) of monitoring the PDCCH / DCI, the request from the UE2 to the gNB1 may be an RRC layer signaling, a MAC layer (Layer-2) signaling, or a physical layer (Layer-1) signaling.

[0050] The gNB1 may change the activation / deactivation of the search space of the UE2 based on a Radio Network Temporary Identifier (RNTI). Specifically, the gNB1 may determine the service type of the UE2 from the RNTI and change the activation / deactivation of the search space according to the service type.

[0051] In the case of CA, gNB1 may send signaling for activating (or deactivating) a search space to UE2 in a serving cell other than the serving cell in which the search space is configured, for example by MAC layer (Layer-2) signaling.

[0052] To activate (or deactivate) a search space, the gNB1 may use signaling of a lower layer (e.g., a Physical (PHY) layer or a Medium Access Control (MAC) layer) instead of the RRC layer. More specifically, the activation (or deactivation) of a search space may be performed by signaling of a physical layer (Layer-1), for example, a PDCCH / DCI transmitted in any search space (e.g., common search space #0). Alternatively, the activation (or deactivation) of a search space may be performed by signaling of a MAC layer (Layer-2), for example, a MAC Control Element (CE).

[0053] 6A, 6B, and 6C show examples of formats of MAC CEs used for search space activation / deactivation (eg, Search Space Activation / Deactivation MAC CEs).

[0054] In the example of FIG. 6A, the first octet of the MAC CE 610 indicates a Serving Cell ID field and a BWP ID field. The Serving Cell ID field indicates an identifier of a serving cell to which the MAC CE applies. The BWP ID field indicates an identifier of a downlink BWP to which the MAC CE applies. The symbol "R" means a reserved bit. The SSi fields (i.e., SS0 to SS15) in the second and third octets of the MAC CE 610 indicate the activation status of a search space having a Search Space ID i. For example, the SSi field may be set to "0" to indicate that the search space having Search Space ID i is deactivated. Meanwhile, the SSi field may be set to "1" to indicate that the search space having Search Space ID i is activated.

[0055] Note that a search space with Search Space ID 0 (search space #0) is associated with a common search space of an initial downlink BWP configured via a Master Information Block (MIB) transmitted on a Physical Broadcast Channel (PBCH). Since search space #0 is always activated or not configured in an SCell, the UE 2 may ignore the SS0 field in Fig. 6A. Alternatively, as in the examples of MAC CE 620 and MAC CE 630 shown in Fig. 6B and Fig. 6C, the Search Space Activation / Deactivation MAC CE may not include the SS0 field.

[0056] <Third embodiment> In the above embodiment, the gNB1 may transmit an RRC message including a list of search spaces configured for the UE2 to the UE2 via another base station (e.g., gNB or eNB). Specifically, the gNB1 may transmit an RRC message to the UE2 via the other base station upon handover of the UE2 from the other base station to the gNB1. Additionally or alternatively, when the gNB1 operates as a secondary node (i.e., SgNB) of the DC, the gNB1 may transmit an RRC message to the UE2 via the other base station operating as a master node (e.g., MgNB or MeNB).

[0057] <Fourth embodiment> In the above-described embodiment, the gNB1 and the UE2 may be configured as follows. FIG. 7 is a block diagram showing an example of the configuration of the gNB1 according to the above-described embodiment. Referring to FIG. 7, the gNB1 includes a radio frequency transceiver 701, a network interface 703, a processor 704, and a memory 705. The RF transceiver 701 performs analog RF signal processing to communicate with UEs including the UE2. The RF transceiver 701 may include multiple transceivers. The RF transceiver 701 is coupled to an antenna array 702 and a processor 704. The RF transceiver 701 receives modulation symbol data from the processor 704, generates a transmit RF signal, and provides the transmit RF signal to the antenna array 702. The RF transceiver 701 also generates a baseband receive signal based on the receive RF signal received by the antenna array 702, and provides the baseband receive signal to the processor 704. The RF transceiver 701 may include an analog beamformer circuit for beamforming. The analog beamformer circuit includes, for example, multiple phase shifters and multiple power amplifiers.

[0058] The network interface 703 is used to communicate with network nodes (eg, 5G Core control nodes and forwarding nodes). The network interface 703 may include, for example, a network interface card (NIC) compliant with the IEEE 802.3 series.

[0059] The processor 704 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. The processor 704 may include multiple processors. For example, the processor 704 may include a modem processor (e.g., Digital Signal Processor (DSP)) that performs digital baseband signal processing and a protocol stack processor (e.g., Central Processing Unit (CPU) or Micro Processing Unit (MPU)) that performs control plane processing.

[0060] For example, digital baseband signal processing by the processor 704 may include signal processing of a Service Data Adaptation Protocol (SDAP) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, a MAC layer, and a PHY layer, and control plane processing by the processor 704 may include processing of Non-Access Stratum (NAS) messages, RRC messages, MAC CEs, and DCIs.

[0061] The processor 704 may include a digital beamformer module for beamforming, which may include a Multiple Input Multiple Output (MIMO) encoder and a precoder.

[0062] The memory 705 is configured by a combination of volatile memory and non-volatile memory. The volatile memory is, for example, Static Random Access Memory (SRAM) or Dynamic RAM (DRAM), or a combination thereof. The non-volatile memory is, for example, Mask Read Only Memory (MROM), Electrically Erasable Programmable ROM (EEPROM), flash memory, or a hard disk drive, or any combination thereof. The memory 705 may include storage located remotely from the processor 704. In this case, the processor 704 may access the memory 705 via the network interface 703 or an I / O interface not shown.

[0063] The memory 705 may store one or more software modules (computer programs) 706 including instructions and data for performing the processing by the gNB1 described in the above-mentioned embodiments. In some implementations, the processor 704 may be configured to read the software modules 706 from the memory 705 and execute them to perform the processing by the gNB1 described in the above-mentioned embodiments.

[0064] In addition, if gNB1 is a gNB-CU, gNB1 may not include RF transceiver 701 (and antenna array 702).

[0065] FIG. 8 is a block diagram showing an example of the configuration of the UE2. A radio frequency (RF) transceiver 801 performs analog RF signal processing to communicate with the gNB1. The RF transceiver 801 may include multiple transceivers. The analog RF signal processing performed by the RF transceiver 801 includes frequency up-conversion, frequency down-conversion, and amplification. The RF transceiver 801 is coupled to an antenna array 802 and a baseband processor 803. The RF transceiver 801 receives modulation symbol data (or OFDM symbol data) from the baseband processor 803, generates a transmission RF signal, and provides the transmission RF signal to the antenna array 802. The RF transceiver 801 also generates a baseband reception signal based on the reception RF signal received by the antenna array 802, and provides the baseband reception signal to the baseband processor 803. The RF transceiver 801 may include an analog beamformer circuit for beamforming. The analog beamformer circuit includes, for example, multiple phase shifters and multiple power amplifiers.

[0066] The baseband processor 803 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. Digital baseband signal processing includes (a) data compression / decompression, (b) data segmentation / concatenation, (c) generation / decomposition of transmission format (transmission frame), (d) transmission line coding / decoding, (e) modulation (symbol mapping) / demodulation, and (f) generation of OFDM symbol data (baseband OFDM signal) by Inverse Fast Fourier Transform (IFFT). Meanwhile, control plane processing includes communication management of layer 1 (e.g., transmission power control), layer 2 (e.g., radio resource management, and hybrid automatic repeat request (HARQ) processing), and layer 3 (e.g., signaling related to attachment, mobility, and call management).

[0067] For example, the digital baseband signal processing by the baseband processor 803 may include signal processing of a Service Data Adaptation Protocol (SDAP) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, a MAC layer, and a PHY layer. Also, the control plane processing by the baseband processor 803 may include processing of NAS messages, RRC messages, MAC CEs, and DCIs.

[0068] The baseband processor 803 may perform MIMO encoding and precoding for beamforming.

[0069] The baseband processor 803 may include a modem processor (e.g., DSP) that performs digital baseband signal processing and a protocol stack processor (e.g., CPU or MPU) that performs control plane processing. In this case, the protocol stack processor that performs control plane processing may be shared with the application processor 804 described later.

[0070] The application processor 804 is also called a CPU, an MPU, a microprocessor, or a processor core. The application processor 804 may include multiple processors (multiple processor cores). The application processor 804 executes a system software program (operating system (OS)) and various application programs (e.g., a calling application, a web browser, a mailer, a camera operation application, and a music playback application) read from the memory 806 or a memory not shown, thereby implementing various functions of the UE2.

[0071] In some implementations, the baseband processor 803 and the application processor 804 may be integrated on a single chip, as shown by the dashed line (805) in Figure 8. In other words, the baseband processor 803 and the application processor 804 may be implemented as a single System on Chip (SoC) device 805. An SoC device may also be called a system Large Scale Integration (LSI) or a chipset.

[0072] The memory 806 is a volatile memory or a non-volatile memory, or a combination thereof. The memory 806 may include a plurality of physically independent memory devices. The volatile memory is, for example, an SRAM or a DRAM, or a combination thereof. The non-volatile memory is an MROM, an EEPROM, a flash memory, or a hard disk drive, or any combination thereof. For example, the memory 806 may include an external memory device accessible from the baseband processor 803, the application processor 804, and the SoC 805. The memory 806 may include an internal memory device integrated in the baseband processor 803, the application processor 804, or the SoC 805. Furthermore, the memory 806 may include a memory in a Universal Integrated Circuit Card (UICC).

[0073] The memory 806 may store one or more software modules (computer programs) 807 including instructions and data for performing the processes by the UE 2 described in the above-mentioned embodiments. In some implementations, the baseband processor 803 or the application processor 804 may be configured to read the software modules 807 from the memory 806 and execute them to perform the processes by the UE 2 described in the above-mentioned embodiments using the drawings.

[0074] In addition, the control plane processing and operations performed by UE2 described in the above embodiment can be realized by elements other than the RF transceiver 801 and the antenna array 802, i.e., at least one of the baseband processor 803 and the application processor 804, and the memory 806 storing the software module 807.

[0075] As described with reference to FIG. 7 and FIG. 8, each of the processors of the gNB1 and UE2 according to the above-described embodiment executes one or more programs including instructions for causing a computer to perform the algorithm described with reference to the drawings. The program can be stored and provided to a computer using various types of non-transitory computer readable media. The non-transitory computer readable medium includes various types of tangible storage media. Examples of the non-transitory computer readable medium include magnetic recording media (e.g., flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (e.g., magneto-optical disks), Compact Disc Read Only Memory (CD-ROM), CD-R, CD-R / W, and semiconductor memory (e.g., mask ROM, Programmable ROM (PROM), Erasable PROM (EPROM), flash ROM, Random Access Memory (RAM)). The program may also be provided to a computer by various types of transitory computer readable media. Examples of the transitory computer readable medium include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire or an optical fiber, or via a wireless communication path.

[0076] <Other embodiments> The above-described embodiments may be implemented independently of each other, or the whole or part of the embodiments may be implemented in appropriate combination.

[0077] In the above embodiment, the serving cell configuration for the SCell may include information (e.g., a flag) indicating a UE-specific search space that the UE2 should always monitor. If a common search space is not configured in the downlink BWP of the SCell, the UE2 can receive the PDCCH / DCI by monitoring the UE-specific search space indicated by the flag. Such a UE-specific search space may be referred to as a default search space.

[0078] A wireless terminal (User Equipment (UE)) in this specification is an entity connected to a network via a radio interface. The wireless terminal (UE) in this specification is not limited to a dedicated communication device, but may be any device having the communication function of the wireless terminal (UE) described in this specification, such as:

[0079] The terms "User Equipment (UE)" (as the term is used in 3GPP), "mobile station", "mobile terminal", "mobile device" and "wireless device" are generally intended to be synonymous with each other. A UE may be a standalone mobile station such as a terminal, a mobile phone, a smartphone, a tablet, a cellular IoT terminal, an IoT device, etc. The terms "UE" and "wireless terminal" also encompass devices that are stationary for extended periods of time.

[0080] The UE may be, for example, production equipment, manufacturing equipment, and / or energy related machinery (including, by way of example only, boilers, engines, turbines, solar panels, wind power generators, hydroelectric generators, thermal power generators, nuclear generators, batteries, nuclear power systems, nuclear related equipment, heavy electrical equipment, pumps including vacuum pumps, compressors, fans, blowers, hydraulic equipment, pneumatic equipment, metal processing machinery, manipulators, robots, robot application systems, tools, dies, rolls, conveying equipment, lifting equipment, cargo handling equipment, textile machinery, sewing machinery, printing presses, printing related machinery, paper converting machinery, chemical machinery, mining machinery, mining related machinery, construction machinery, construction related machinery, agricultural machinery and / or equipment, forestry machinery and / or equipment, fishing machinery and / or equipment, safety and / or environmental protection equipment, tractors, bearings, precision bearings, chains, cogwheels, power transmission equipment, lubrication equipment, valves, fittings, and / or application systems of any of the equipment or machinery mentioned above).

[0081] The UE may be, for example, a transportation device (by way of example only, a vehicle, an automobile, a motorcycle, a bicycle, a train, a bus, a handcart, a rickshaw, a ship and other watercraft, an airplane, a rocket, a satellite, a drone, a balloon, etc.).

[0082] The UE may be, for example, a device for information communication (eg, an electronic computer and related devices, a communication device and related devices, an electronic component, etc.).

[0083] The UE may be, for example, a refrigerator, a refrigerator application product and device, commercial and service equipment, a vending machine, an automatic service machine, an office machine and device, or a consumer electric or electronic machine (for example, an audio device, a speaker, a radio, a video device, a television, an oven range, a rice cooker, a coffee maker, a dishwasher, a washing machine, a dryer, an electric fan, a ventilation fan and related products, a vacuum cleaner, etc.).

[0084] The UE may be, for example, an electronic application system or device (eg, an x-ray device, a particle accelerator device, a radioactive material application device, a sonic application device, an electromagnetic application device, a power application device, etc.).

[0085] The UE may be, for example, a light bulb, a light, a weighing machine, an analytical instrument, a testing and measuring instrument (including, by way of example, a smoke alarm, an occupancy alarm sensor, a motion sensor, a radio tag, etc.), a watch or clock, a lab machine, an optical machine, a medical instrument and / or a medical system, a weapon, a sharp tool, or a hand tool.

[0086] The UE may be, for example, a personal digital assistant or device with wireless communication capabilities (e.g., an electronic device (e.g., a personal computer, electronic measuring instrument, etc.) configured to accommodate or accept a wireless card, wireless module, etc.).

[0087] The UE may be, for example, a device or part of a device that provides the following applications, services, and solutions in the "Internet of Things" (IoT) using wired and wireless communication technologies: IoT devices (or things) comprise appropriate electronics, software, sensors, network connections, etc. that enable the devices to collect and exchange data with each other and with other communication devices. IoT devices may be automated devices that follow stored software instructions in their internal memory. IoT devices may operate without the need for human supervision or attention. IoT devices may be devices that are stationary and / or remain inactive for long periods of time. IoT devices may be implemented as part of stationary devices. IoT devices may be embedded in non-stationary devices (such as vehicles) or attached to animals or people being monitored / tracked. IoT technology may be implemented on any communication device that can be connected to a communication network to send and receive data without control by human input or software instructions stored in memory. IoT devices are also sometimes called Machine Type Communication (MTC) devices, or Machine to Machine (M2M) communication devices, or Narrow Band-IoT (NB-IoT) UEs.

[0088] The UE may support one or more IoT or MTC applications.

[0089] Some examples of MTC applications are listed in the list given in 3GPP TS22.368 V13.2.0(2017-01-13) Annex B, the contents of which are incorporated herein by reference. This list is not exhaustive but shows exemplary MTC applications. In this list, the Service Areas of the MTC applications include Security, Tracking & Tracing, Payment, Health, Remote Maintenance / Control, Metering, and Consumer Devices.

[0090] Examples of MTC applications related to security include Surveillance systems, Backup for landline, Control of physical access (eg to buildings), and Car / driver security.

[0091] Examples of MTC applications related to track and trace include Fleet Management, Order Management, Telematics Insurance: Pay as you drive (PAYD), Asset Tracking, Navigation, Traffic information, Road tolling, and Road traffic optimisation / steering.

[0092] Examples of payment related MTC applications include Point of sales (POS), Vending machines, and Gaming machines.

[0093] Examples of health-related MTC applications include Monitoring vital signs, Supporting the aged or handicapped, Web Access Telemedicine points, and Remote diagnostics.

[0094] Examples of MTC applications for remote maintenance / control include Sensors, Lighting, Pumps, Valves, Elevator control, Vending machine control, and Vehicle diagnostics.

[0095] Examples of MTC applications related to metering are Power, Gas Includes Water, Heating, Grid control, and Industrial metering.

[0096] Examples of MTC applications for consumer devices include digital photo frames, digital cameras, and ebooks.

[0097] Furthermore, the above-described embodiment is merely an example of application of the technical idea obtained by the inventor of the present invention. In other words, the technical idea is not limited to the above-described embodiment, and various modifications are possible.

[0098] For example, some or all of the above embodiments may be described as, but are not limited to, the following supplementary notes.

[0099] (Appendix 1) A wireless terminal, At least one memory; at least one processor coupled to the at least one memory; Equipped with The at least one processor is configured to receive, via a dedicated signaling message addressed to the wireless terminal, a first information element indicating a list of search spaces configured by a base station for the wireless terminal; the first information element includes a second information element indicating a configuration of each search space required for the wireless terminal to monitor downlink control information in each search space included in the list; The first information element further includes a third information element indicating, on a per-search space basis, whether each search space is initially deactivated. Wireless terminal.

[0100] (Appendix 2) the at least one processor is configured to determine, for each search space, whether each search space needs to be monitored to receive downlink control information based on the third information element. 2. A wireless terminal as defined in claim 1.

[0101] (Appendix 3) The at least one processor is configured to determine, when the third information element indicates deactivation, that a search space associated with the third information element does not need to be monitored to receive downlink control information; the at least one processor is configured to determine, if the third information element does not indicate deactivation, that the search space associated with the third information element needs to be monitored to receive downlink control information. 3. A wireless terminal according to claim 1 or 2.

[0102] (Appendix 4) the at least one processor is configured to perform Radio Resource Control (RRC) layer operations; The RRC layer operation includes, when the third information element indicates deactivation, informing a physical layer of the wireless terminal that a search space associated with the third information element does not need to be monitored. 4. The wireless terminal according to claim 1,

[0103] (Appendix 5) the at least one processor is configured to perform Radio Resource Control (RRC) layer operations; The RRC layer operation includes configuring a physical layer of the wireless terminal not to monitor a search space associated with the third information element when the third information element indicates deactivation. 4. The wireless terminal according to claim 1,

[0104] (Appendix 6) The second information element includes an information element indicating an identifier of each search space; 6. The wireless terminal according to claim 1,

[0105] (Appendix 7) The second information element includes at least one of an information element indicating a resource location of each search space, an information element indicating a type of each search space, an information element indicating a type of downlink control information to be monitored in each search space, and an information element indicating a periodicity of each search space. 7. The wireless terminal according to claim 1,

[0106] (Appendix 8) The first information element relates to a configuration of one downlink Bandwidth Part (BWP), The second and third information elements include, for each search space configured in the downlink BWP, 8. The wireless terminal according to claim 1,

[0107] (Appendix 9) The dedicated signaling message is a Radio Resource Control (RRC) message. 9. The wireless terminal according to claim 1,

[0108] (Appendix 10) the first information element is a searchSpacesToAddModList information element; the second information element is a SearchSpace information element included in the searchSpacesToAddModList information element, The third information element is included in the SearchSpace information element. 10. The wireless terminal of claim 9.

[0109] (Appendix 11) the at least one processor is configured to receive the dedicated signaling message via the other base station upon handover of the wireless terminal from the other base station to the base station. 11. The wireless terminal according to claim 1.

[0110] (Appendix 12) A base station, At least one memory; at least one processor coupled to the at least one memory; Equipped with The at least one processor is configured to transmit, via a dedicated signaling message addressed to the wireless terminal, a first information element indicating a list of search spaces configured by the base station for the wireless terminal; the first information element includes a second information element indicating a configuration of each search space required for the wireless terminal to monitor downlink control information in each search space included in the list; The first information element further includes a third information element indicating, on a per-search space basis, whether each search space is initially deactivated. Base station.

[0111] (Appendix 13) The third information element prompts the wireless terminal to determine, for each search space, whether each search space needs to be monitored to receive downlink control information. 13. The base station according to claim 12.

[0112] (Appendix 14) the third information element prompts the wireless terminal to determine that a search space associated with the third information element does not need to be monitored to receive downlink control information if the third information element indicates deactivation; the third information element causes the wireless terminal to determine that the search space associated with the third information element needs to be monitored to receive downlink control information if the third information element does not indicate deactivation. 14. The base station according to claim 12 or 13.

[0113] (Appendix 15) The third information element prompts a Radio Resource Control (RRC) layer of the wireless terminal to inform a physical layer of the wireless terminal that a search space associated with the third information element does not need to be monitored if the third information element indicates deactivation. The base station according to any one of Supplementary notes 12 to 14.

[0114] (Appendix 16) The third information element prompts a Radio Resource Control (RRC) layer of the wireless terminal to configure a physical layer of the wireless terminal not to monitor a search space associated with the third information element if the third information element indicates deactivation. The base station according to any one of Supplementary notes 12 to 14.

[0115] (Appendix 17) The second information element includes an information element indicating an identifier of each search space; The base station according to any one of Supplementary notes 12 to 16.

[0116] (Appendix 18) The second information element includes at least one of an information element indicating a resource location of each search space, an information element indicating a type of each search space, an information element indicating a type of downlink control information to be monitored in each search space, and an information element indicating a periodicity of each search space. 18. The base station according to claim 12,

[0117] (Appendix 19) The first information element relates to a plurality of search spaces set in one downlink bandwidth part (BWP), The second and third information elements include, for each search space configured in the downlink BWP, The base station according to any one of Supplementary notes 12 to 18.

[0118] (Appendix 20) The dedicated signaling message is a Radio Resource Control (RRC) message. The base station according to any one of Supplementary notes 12 to 19.

[0119] (Appendix 21) the first information element is a searchSpacesToAddModList information element; the second information element is a SearchSpace information element included in the searchSpacesToAddModList information element, The third information element is included in the SearchSpace information element. 21. The base station of claim 20.

[0120] (Appendix 22) the at least one processor is configured to transmit the dedicated signaling message to the wireless terminal via the other base station upon handover of the wireless terminal from the other base station to the base station. The base station according to any one of Supplementary notes 12 to 21.

[0121] (Appendix 23) 1. A method for a wireless terminal, comprising: receiving, via a dedicated signaling message addressed to the wireless terminal, a first information element indicating a list of search spaces configured by a base station for the wireless terminal; the first information element includes a second information element indicating a configuration of each search space required for the wireless terminal to monitor downlink control information in each search space included in the list; The first information element further includes a third information element indicating, on a per-search space basis, whether each search space is initially deactivated. method.

[0122] (Appendix 24) 1. A method for a base station, comprising: transmitting a first information element indicating a list of search spaces configured by the base station for the wireless terminal via a dedicated signaling message addressed to the wireless terminal; the first information element includes a second information element indicating a configuration of each search space required for the wireless terminal to monitor downlink control information in each search space included in the list; The first information element further includes a third information element indicating, on a per-search space basis, whether each search space is initially deactivated. method.

[0123] (Appendix 25) A program for causing a computer to perform a method for a wireless terminal, comprising: The method comprises receiving, via a dedicated signaling message addressed to the wireless terminal, a first information element indicating a list of search spaces configured by a base station for the wireless terminal; the first information element includes a second information element indicating a configuration of each search space required for the wireless terminal to monitor downlink control information in each search space included in the list; The first information element further includes a third information element indicating, on a per-search space basis, whether each search space is initially deactivated. program.

[0124] (Appendix 26) A program for causing a computer to perform a method for a base station, comprising: The method comprises transmitting a first information element to the wireless terminal via a dedicated signaling message addressed to the wireless terminal, the first information element indicating a list of search spaces configured by the base station for the wireless terminal; the first information element includes a second information element indicating a configuration of each search space required for the wireless terminal to monitor downlink control information in each search space included in the list; The first information element further includes a third information element indicating, on a per-search space basis, whether each search space is initially deactivated. program.

[0125] This application claims priority based on Japanese Patent Application No. 2019-022949, filed on February 12, 2019, the disclosure of which is incorporated herein in its entirety. [Explanation of symbols]

[0126] 1 gNB 2. UE 101 Air Interface 604 Processor 605 Memory 703 Baseband Processor 704 Application Processor 706 Memory

Claims

1. A wireless terminal, receiving means for receiving from a base station first information indicating a list of a plurality of search spaces and second information indicating that the wireless terminal is to monitor at least one search space included in the list; the second information indicates that at least one search space included in the list is initially monitored by the wireless terminal, and that a search space not monitored by the wireless terminal is initially deactivated. Wireless terminal.

2. The receiving means further receives third information from the base station, the third information indicating that a state of one or more search spaces included in the list is to be changed to an active state or a deactivated state. The wireless terminal of claim 1.

3. The receiving means receives at least one of the first information and the second information in an RRC (Radio Resource Control) message.

3. A wireless terminal according to claim 1 or 2.

4. The RRC message is an RRC Setup message.

4. The wireless terminal of claim 3.

5. 1. A method for a wireless terminal, comprising: receiving, from a base station, first information indicating a list of a plurality of search spaces and second information indicating that the wireless terminal is to monitor a portion of the search spaces included in the list; the second information indicates that at least one search space included in the list is initially monitored by the wireless terminal, and that a search space not monitored by the wireless terminal is initially deactivated. A method for wireless terminals.

6. A base station, a transmitting means for transmitting, to a wireless terminal, first information indicating a list of a plurality of search spaces and second information indicating that the wireless terminal is to monitor a part of the search spaces included in the list; the second information indicates that at least one search space included in the list is initially monitored by the wireless terminal, and that a search space not monitored by the wireless terminal is initially deactivated. Base station.

7. 1. A method of a base station, comprising: First information indicating a list of a plurality of search spaces, and second information indicating that a wireless terminal is to monitor a portion of the search spaces included in the list, Transmitting to the wireless terminal, the second information indicates that at least one search space included in the list is initially monitored by the wireless terminal, and that a search space not monitored by the wireless terminal is initially deactivated. Base station method.

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