User Equipment and Base Station Involved in the Adaptation Procedure

Abstract

The present disclosure relates to a user equipment UE comprising: a receiver of the UE receives a first control signal from a base station, the first control signal being common to a radio cell to which the UE belongs or a group of UEs, the first control signal indicating an operating target bandwidth part BWP; a processing circuit of the UE operates according to the indicated target BWP.

Description

[Technical field]

[0001] The present disclosure is directed to methods, apparatus, and articles in communication systems, such as 3GPP® communication systems. [Background technology]

[0002] Currently, the 3rd Generation Partnership Project (3GPP) is working on technical specifications for the next generation of cellular technology, also known as the fifth generation (5G).

[0003] One objective is to provide a single technical framework that addresses all usage scenarios, requirements, and deployment scenarios (e.g., see 3GPP TR 38.913 version 16.0.0, section 6), including at least enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine type communication (mMTC). For example, eMBB deployment scenarios may include indoor hotspots, dense urban, rural, urban macro, and high speed, URLLC deployment scenarios may include industrial control systems, mobile healthcare (remote monitoring, diagnosis, and treatment), real-time control of vehicles, wide area monitoring, and control systems for smart grids, and mMTC deployment scenarios may include scenarios with a large number of devices with non-time-critical data transfer, such as smart wearables and sensor networks. eMBB and URLLC services are similar in that both require very high bandwidth, but differ in that URLLC services may preferably require ultra-low latency.

[0004] A second objective is to achieve forward compatibility: backward compatibility to Long Term Evolution (LTE, LTE-A) cellular systems is not required, thus facilitating the introduction of entirely new system designs and / or novel features. Summary of the Invention [Problem to be solved by the invention]

[0005] One non-limiting exemplary embodiment facilitates providing a procedure for a UE to perform an improved adaptation procedure. [Means for solving the problem]

[0006] In one embodiment, the technology disclosed herein features a user equipment UE comprising: a receiver of the UE receives a first control signal from a base station, the first control signal being common to a radio cell to which the UE belongs or a group of UEs, the first control signal indicating an operating target bandwidth part BWP, and a processing circuit of the UE operates according to the indicated target BWP.

[0007] It should be noted that the general or specific embodiments may be implemented as a system, a method, an integrated circuit, a computer program, a storage medium, or any combination thereof. For example, an integrated circuit may control processing of a UE or a base station.

[0008] Further benefits and advantages of the disclosed embodiments and various implementations will become apparent from the specification and drawings. These benefits and / or advantages may be obtained individually by the various embodiments and features of the specification and drawings, and it is not necessary for all of the embodiments and features to be provided in order to obtain one or more of such benefits and / or advantages. [Brief description of the drawings]

[0009] The following embodiments are explained in more detail with reference to the accompanying drawings. [Figure 1] FIG. 1 is an example architecture diagram of a 3GPP NR system. [Diagram 2] Schematic showing the functional separation between NG-RAN and 5GC [Diagram 3] Sequence diagram of RRC connection setup / reconfiguration procedure [Figure 4] Schematic diagram showing the usage scenarios for enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable low latency communications (URLLC) [Diagram 5] Block diagram illustrating an example 5G system architecture for a non-roaming scenario [Figure 6] A diagram showing the relationship between bandwidth parts, control resource sets (CORESETs), search spaces, search space sets, and PDCCH candidates. [Figure 7] FIG. 1 illustrates an example time domain structure in a communication system such as 5G NR, including radio frames, subframes, slots, and OFDM symbols with different subcarrier spacing. [Figure 8] FIG. 1 illustrates a simplified exemplary implementation of a set of synchronization signal blocks distributed within a half-frame. [Figure 9] A diagram showing several beams and corresponding SSB indices SSB1 to SSB8, as well as how the beams are transmitted by a GNB in ​​a beam sweeping manner. [Figure 10] A diagram showing an exemplary simplified structure of a UE and a GNB. [Figure 11] FIG. 1 illustrates a structure of a UE with an exemplary implementation of an improved adaptation procedure. [Figure 12] 13 is a flow diagram of a UE operation in accordance with an example implementation of an improved adaptation procedure. [Figure 13] FIG. 2 illustrates the structure of a base station with an exemplary implementation of an improved adaptation procedure. [Figure 14] 4 is a flow diagram of the operation of a base station participating in an exemplary implementation of an improved adaptation procedure. [Figure 15] A signaling diagram showing an example exchange between a UE and a GNB in ​​an example implementation of an improved adaptation procedure. [Figure 16] A diagram showing the active BWPs of three UEs before and after BWP switching in an exemplary implementation of the improved adaptation procedure. [Figure 17] A diagram showing the active BWPs of three UEs before and after BWP switching in an exemplary implementation of the improved adaptation procedure. [Figure 18] FIG. 1 illustrates the modification of antenna elements at the GNB and the resulting changes in beams and SSB. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <5G NR system architecture and protocol stack> 3GPP continues to work on the next release of fifth-generation cellular technology (also known simply as "5G"), which includes the development of New Radio Access Technology (NR) that will operate in the frequency range up to 100 GHz. The first version of the 5G standard was completed in late 2017, allowing for the prototyping and commercial deployment of 5G NR-compliant smartphones.

[0011] In particular, the overall system architecture assumes a Next Generation-Radio Access Network (NG-RAN) with gNBs. The gNBs provide the UE-side termination of the NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocols. The gNBs are interconnected with each other by an Xn interface. The gNBs are also connected to the Next Generation Core (NGC) by a Next Generation (NG) interface, more specifically to the Access and Mobility Management Function (AMF, e.g. a specific core entity running AMF) by an NG-C interface and to the User Plane Function (UPF, e.g. a specific core entity running UPF) by an NG-U interface. The NG-RAN architecture is shown in Figure 1 (see, e.g., section 4 of 3GPP TS 38.300 v16.46.0).

[0012] The NR user plane protocol stack (see, for example, section 4.4.1 of 3GPP TS 38.300) includes the PDCP (Packet Data Convergence Protocol, see section 6.4 of TS 38.300) sublayer, the RLC (Radio Link Control, see section 6.3 of TS 38.300) sublayer, and the MAC (Medium Access Control, see section 6.2 of TS 38.300) sublayer, which are terminated on the network side at the gNB. In addition, a new Access Stratum (AS) sublayer (SDAP: Service Data Adaptation Protocol) is introduced above PDCP (see, for example, sub-clause 6.5 of TS 38.300). NR also defines a control plane protocol stack (see, for example, section 4.4.2 of TS 38.300). An overview of Layer 2 functions is given in sub-clause 6 of TS 38.300. The functions of the RRC layer are listed in sub-clause 7 of TS 38.300.

[0013] For example, the MAC layer is responsible for multiplexing logical channels and scheduling and scheduling-related functions, including handling various numerologies.

[0014] The physical layer (PHY) is responsible for, for example, coding, PHY HARQ processing, modulation, multi-antenna processing, and mapping of signals to appropriate physical time-frequency resources. It also maps transport channels to physical channels. The physical layer provides services to the MAC layer in the form of transport channels. A physical channel corresponds to a set of time-frequency resources used for transmission of a particular transport channel, and each transport channel is mapped to a corresponding physical channel. For example, the physical channels are PRACH (Physical Random Access Channel), PUSCH (Physical Uplink Shared Channel), and PUCCH (Physical Uplink Control Channel) in the uplink, and PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), and PBCH (Physical Broadcast Channel) in the downlink.

[0015] NR use cases / deployment scenarios include eMBB (enhanced Mobile Broadband), URLLC (Ultra-Reliable Low-Latency Communications), and mMTC (massive Machine Type Communication), which have diverse requirements for data rate, latency, and coverage. For example, eMBB is required to support peak data rates (20Gbps downlink, 10Gbps uplink) and effective (user-experienced) data rates that are about three times higher than those offered by IMT-Advanced. On the other hand, URLLC has more stringent requirements for ultra-low latency (user plane latency of 0.5ms for both UL and DL) and high reliability (1-10 Mbps latency within 1ms). -5Finally, mMTC preferably requires high connection density (1 million devices per square kilometer in urban environments), wide coverage in adverse environments, and ultra-long battery life (15 years) for low-cost equipment.

[0016] Therefore, OFDM numerology (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) suitable for one use case may not be valid for other use cases. For example, low latency services may preferably require a shorter symbol length (and therefore a larger subcarrier spacing) and / or fewer symbols per scheduling interval (in other words, TTI) than mMTC services. Furthermore, deployment scenarios with large channel delay spreads may preferably require a longer CP length than scenarios with small delay spreads. To maintain similar CP overhead, the subcarrier spacing needs to be optimized accordingly. NR may support multiple values ​​of subcarrier spacing. Correspondingly, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, ... are currently being considered. Symbol length T u and the subcarrier spacing Δf is expressed by the formula Δf=1 / T u Similar to LTE systems, the term "resource element" can be used to denote the smallest resource unit consisting of one subcarrier for the length of one OFDM / SC-FDMA symbol.

[0017] In the new radio system 5G-NR, for each numerology and carrier, a resource grid of subcarriers and OFDM symbols is defined for the uplink and downlink, respectively. Each element of the resource grid is called a resource element and is identified based on a frequency index in the frequency domain and a symbol position in the time domain (see 3GPP TS 38.211 v16.46.0, e.g., section 4). For example, downlink and uplink transmissions are organized into frames with a duration of 10 ms, each frame consisting of 10 subframes of 1 ms duration each. In a 5g NR implementation, the number of consecutive OFDM symbols per subframe depends on the subcarrier spacing setting. For example, for a subcarrier spacing of 15 kHz, a subframe has 14 OFDM symbols (similar to an LTE-compatible implementation assuming a normal cyclic prefix). On the other hand, for a subcarrier spacing of 30 kHz, a subframe has two slots, each slot containing 14 OFDM symbols.

[0018] <Functional separation between NG-RAN and 5GC in 5G NR> Figure 2 shows the functional separation between NG-RAN and 5GC. The logical node of NG-RAN is gNB or ng-eNB. 5GC has logical nodes AMF, UPF, and SMF.

[0019] In particular, the gNB and ng-eNB host the following main functions: - Radio Resource Management functions such as Radio Bearer Control, Radio Admission Control, Connection Mobility Control, dynamic allocation (scheduling) of resources to UEs in both uplink and downlink; - IP header compression, encryption, and integrity protection of data; - Selection of the AMF at UE attach time if routing to the AMF cannot be determined from information provided by the UE; - Routing of user plane data towards the UPF; - Routing of control plane information towards AMF; - Setting up and tearing down connections; - Scheduling and sending paging messages; - Scheduling and transmission of system broadcast information (sourced from AMF or Operation, Admission, Maintenance Function (OAM)); - Setting up measurements and reporting of measurements for mobility and scheduling; - Transport level packet marking in the uplink; - Session management; - Support for network slicing; - QoS flow management and mapping to data radio bearers; - Support for UEs in RRC_INACTIVE state; - Non-Access Stratum (NAS) message delivery function; - Sharing of radio access networks; - Dual connectivity; - Close cooperation between NR and E-UTRA.

[0020] The Access and Mobility Management Function (AMF) hosts the following main functions: - Termination of Non-Access Stratum (NAS) signalling; - NAS signaling security; - Access Layer (AS) security controls; - 3GPP Core Network (CN) inter-node signalling for mobility between access networks; - Reachability to idle mode UEs (including control and execution of paging retransmissions); - Managing the registration area; - Support for intra-system and inter-system mobility; - Access authentication; - Access authorization including roaming privilege checks; - Mobility management control (subscription and policies); - Support for network slicing; - Selection of Session Management Function (SMF).

[0021] Additionally, the User Plane Function (UPF) hosts the following main functions: - Anchor points for intra-RAT / inter-RAT mobility (if applicable); - External PDU (Protocol Data Unit) Session Points for interconnection with data networks; - Packet routing and forwarding; - Packet inspection and policy rule enforcement for the user plane part; - Traffic usage reporting; - an uplink classifier that supports routing of traffic flows to the data network; - Branching Point to support multi-homed PDU sessions; - QoS processing for the user plane (e.g., packet filtering, gating, UL / DL rate enforcement); - Validation of uplink traffic (mapping of SDF to QoS flows); - Downlink packet buffering and downlink data notification triggering.

[0022] Finally, the Session Management Function (SMF) hosts the following main functions: - Session management; - IP address allocation and management for the UE; - Selection and control of the UPF; - Traffic steering setting function in the User Plane Function (UPF) for routing traffic to the appropriate destination; - Policy enforcement and QoS of the control plane; - Notification of downlink data.

[0023] <Procedures for RRC connection setup and reconfiguration> Figure 3 shows some of the interactions between the UE, gNB, and AMF (5GC entity) in the NAS part when the UE moves from RRC_IDLE to RRC_CONNECTED (see TS 38.300).

[0024] RRC is a higher layer signaling (protocol) used for the configuration of the UE and the gNB. In particular, with this transition, the AMF prepares UE context data (which includes, for example, PDU session context, security keys, UE Radio Capability, UE Security Capabilities, etc.) and sends it to the gNB with an INITIAL CONTEXT SETUP REQUEST. The gNB then activates AS security together with the UE. This is done by the gNB sending a SecurityModeCommand message to the UE, and the UE responding with a SecurityModeComplete message to the gNB. The gNB then performs reconfiguration to set up signaling radio bearer 2 (SRB2) and data radio bearer (DRB) by sending an RRCReconfiguration message to the UE and receiving an RRCReconfigurationComplete from the UE. For signaling-only connections, the steps related to RRCReconfiguration are omitted since SRB2 and DRB are not set up. Finally, the gNB informs the AMF that the setup procedure is complete with an INITIAL CONTEXT SETUP RESPONSE.

[0025] Therefore, the present disclosure provides an entity (e.g., AMF, SMF, etc.) of a 5th Generation Core (5GC), comprising: a control circuit that operatively establishes a Next Generation (NG) connection with a gNodeB; and a transmitter that operatively transmits an initial context setup message to the gNodeB via the NG connection such that a signaling radio bearer between the gNodeB and a User Equipment (UE) is set up. Specifically, the gNodeB transmits Radio Resource Control (RRC) signaling including a resource allocation configuration information element (IE) to the UE via the signaling radio bearer. Then, the UE transmits in uplink or receives in downlink based on the resource allocation configuration.

[0026] <IMT usage scenarios after 2020> Figure 4 shows some of the use cases for 5G NR. The 3rd Generation Partnership Project NR (3GPP NR) is considering three use cases that are expected to support a wide variety of services and applications with IMT-2020. The first phase of specifications for enhanced Multimedia Broadcasting (eMBB) has been completed. In addition to further expanding support for eMBB, current and future research is also being conducted on the standardization of ultra-reliable low latency (URLLC) and multiple simultaneous connections. Figure 4 shows examples of usage scenarios that are expected for IMT beyond 2020 (see, for example, Figure 2 in ITU-R M.20183).

[0027] URLLC use cases have stringent performance requirements such as throughput, latency, and availability, and are envisioned as one of the enablers of future vertical applications such as wireless control of industrial production and manufacturing processes, remote medical surgery, power distribution automation for smart grids, and road safety. URLLC's ultra-high reliability is supported by identifying technologies that meet the requirements set by TR 38.913v16.0.0. For NR URLLC in Release 15, the key requirement is to target user plane latency of 0.5 ms UL (uplink) and 0.5 ms DL (downlink). The general URLLC requirement for a single packet transmission is a block error rate (BLER) of 1E-5 for a packet size of 32 bytes with a user plane latency of 1 ms.

[0028] From a physical layer perspective, reliability can be improved in many possible ways. Current room for reliability improvement includes defining a separate CQI table for URLLC, more compact DCI formats, repeated transmission of PDCCH, etc. However, this room can be expanded to achieve ultra-high reliability as NR (with respect to the key requirements of NR URLLC) becomes more stable and more developed. Specific use cases for NR URLLC in Release 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0029] Also, technology extensions targeted by NR URLLC aim to improve latency and reliability. Technology extensions for improving latency include configurable numerology, non-slot-based scheduling with flexible mapping, grant-free (configurable grant) uplink, repeated transmissions at slot level in data channel, and pre-emption in downlink. Pre-emption means that a transmission with already allocated resources is stopped and the already allocated resources are used for other transmissions with lower latency / higher priority requirements that are requested later. Thus, a transmission that was already allowed is preempted by a later transmission. Pre-emption is applicable regardless of the specific service type. For example, a transmission of service type A (URLLC) can be preempted by a transmission of service type B (eMBB, etc.). Technology extensions for improving reliability include dedicated CQI / MCS tables for a target BLER of 1E-5.

[0030] The mMTC (Massive Machine Type Communication) use case is characterized by a very large number of connected devices that typically transmit relatively small amounts of data that are not sensitive to latency. The devices are required to be low cost and have very long battery life. From an NR perspective, the use of very narrow bandwidth portions is one solution that saves power from the UE's perspective and allows for long battery life.

[0031] As mentioned above, it is expected that the scope of reliability improvement in NR will be broader. One of the key requirements for all cases, especially for URLLC and mMTC, is high or ultra-high reliability. Several mechanisms can be considered that can improve reliability from a radio perspective and a network perspective. In general, there are two to three key areas that can help improve reliability. These areas include compact control channel information, repeated transmission of data channel / control channel, and diversity with respect to frequency domain, time domain, and / or spatial domain. These areas are generally applicable to reliability improvement regardless of the specific communication scenario.

[0032] Further use cases with more stringent requirements are envisaged for NR URLLC, such as factory automation, transportation, and power distribution. The stringent requirements include high reliability (10 6 level of reliability), high availability, packet size up to 256 bytes, time synchronization up to a few μs (depending on the use case, the value can be 1 μs or a few μs depending on the frequency range and short latency on the order of 0.5 ms to 1 ms (in particular, a targeted latency of 0.5 ms on the user plane).

[0033] Furthermore, for NR URLLC, several technical extensions may be available from the perspective of the physical layer. These technical extensions include the extension of the Physical Downlink Control Channel (PDCCH) related to compact DCI, the repeated transmission of PDCCH, and the increase in the monitoring of PDCCH. In addition, the extension of UCI (Uplink Control Information) is related to the extension of enhanced HARQ (Hybrid Automatic Repeat Request) and CSI feedback. Also, there may be extensions of PUSCH related to mini-slot level hopping, and extensions of retransmission / repeated transmission. The term "mini-slot" refers to a transmission time interval (TTI) that contains fewer symbols than a slot (a slot contains 14 symbols).

[0034] <QoS Control> The QoS (Quality of Service) model of 5G is based on QoS flows and supports both QoS flows that require a guaranteed flow bit rate (GBR (Granteed Bit Rate) QoS flows) and QoS flows that do not require a guaranteed flow bit rate (non-GBR QoS flows). Therefore, at the NAS level, a QoS flow is the finest-grained QoS differentiation in a PDU session. A QoS flow is identified within a PDU session by a QoS Flow ID (QFI: QoS Flow ID) that is carried in an encapsulation header via the NG-U interface.

[0035] For each UE, the 5GC establishes one or more PDU sessions. For each UE, the NG-RAN establishes at least one Data Radio Bearer (DRB) for the PDU session, e.g. as shown above with reference to Fig. 3. Additional DRBs for the QoS flows of the PDU session can be configured later (when it is up to the NG-RAN). The NG-RAN maps packets belonging to different PDU sessions to different DRBs. The NAS level packet filters in the UE and the 5GC associate UL and DL packets with QoS flows, whereas the AS level mapping rules in the UE and the NG-RAN associate UL and DL QoS flows with DRBs.

[0036] FIG. 5 shows a non-roaming reference architecture for 5G NR (see, for example, 3GPP TS 23.501 v16.9.0 or v16.7.1.1, section 4.2.3). An application function (AF), such as an external application server hosting a 5G service, as illustrated in FIG. 4, interacts with the 3GPP core network to provide the service. For example, it may access a network exposure function (NEF) to support applications that affect traffic routing, and interact with a policy framework for policy control such as QoS control (see Policy Control Function (PCF)). Based on the operator's deployment, application functions that are deemed trusted by the operator may directly interact with the relevant network functions. Application functions that are not allowed by the operator to directly access network functions interact with the relevant network functions using an external exposure framework via the NEF.

[0037] Figure 5 further illustrates further functional units of the 5G architecture, namely, Network Slice Selection Function (NSSF), Network Repository Function (NRF), Unified Data Management (UDM), Authentication Server Function (AUSF), Access and Mobility Management Function (AMF), Session Management Function (SMF), and Data Network (DN, e.g., operator-provided services, Internet access, or third-party services). All or part of the core network functions and application services may be deployed and run in a cloud computing environment.

[0038] Therefore, the present disclosure provides an application server (e.g., an AF in a 5G architecture) comprising: a transmitter that, in operation, sends a request including QoS requirements for at least one of a URLLC service, an eMBB service, and an mMTC service to at least one of the 5GC functions (e.g., NEF, AMF, SMF, PCF, UPF, etc.) to establish a PDU session including a radio bearer between a gNodeB and a UE according to the QoS requirements; and a control circuit that, in operation, performs a service using the established PDU session.

[0039] Bandwidth Part - BWP The NR system supports a maximum channel bandwidth (e.g., 100 MHz) that is much wider than the 20 MHz bandwidth of LTE. LTE also supports wideband communication via carrier aggregation (CA) of component carriers up to 20 MHz. Defining a wider channel bandwidth in NR allows for dynamic allocation of frequency resources via scheduling, which can be more efficient and flexible than the carrier aggregation operation of LTE, whose activation / deactivation is based on MAC control elements. Having a single wideband carrier also benefits in terms of lower control overhead, since only one control signaling is required (carrier aggregation requires separate control signaling for each aggregated carrier).

[0040] Also, like LTE, NR may support aggregation of multiple carriers via carrier aggregation or dual connectivity.

[0041] Since UEs do not always require high data rates, the use of wide bandwidths can lead to high idle power consumption in terms of both RF and baseband signal processing. In this regard, the newly developed bandwidth part concept for NR offers an energy-efficient solution despite supporting wideband operation by providing a means to operate UEs with bandwidths narrower than the configured channel bandwidth. Low-end terminals that cannot access the full NR bandwidth can benefit from it.

[0042] A bandwidth part (BWP) is a subset of the total cell bandwidth of a cell, e.g., defined by the location and number of contiguous physical resource blocks (PRBs). It may be defined separately for uplink and downlink. Furthermore, each bandwidth part may be associated with a specific OFDM numerology, e.g., subcarrier spacing and cyclic prefix. For example, bandwidth adaptation is achieved by configuring a BWP(s) in a UE and informing the UE which of the configured BWPs is currently active.

[0043] Exemplarily, in 5G NR, a specific BWP is configured only for a UE in the RRC_Connected state. For example, other than an initial BWP (e.g., one for UL and one for DL), BWPs exist only for UEs in the connected state. To support initial data exchange between the UE and the network, such as in the process of transitioning the UE from the RRC_IDLE or RRC_INACTIVE state to the RRC_CONNECTED state, the initial DL BWP and the initial UL BWP are configured with minimum system information.

[0044] Although a UE can be configured with more than one BWP (e.g., up to four BWPs per serving cell as currently defined in NR), a UE can only have one active DL BWP at a time.

[0045] There are several types of BWPs, namely initial BWP, first active BWP, default BWP and other (normal) BWPs that can be configured in the UE, including dormant BWP.

[0046] The first active DL BWP is the BWP that becomes active immediately after the initial connection is completed.

[0047] The default DL BWP is the BWP to which the UE / BS will automatically switch if there is no activity on the current BWP (see bwp-Inactivity Timer).

[0048] An initial UL BWP can be configured for the SpCell and is activated upon performing a reconfiguration in which it is received.

[0049] A dormant BWP is one of the downlink BWPs configured by the network, e.g., using dedicated RRC signaling. In a dormant BWP, the UE stops monitoring the PDCCH on / for the Scell. Meanwhile, the UE may continue to perform, e.g., CSI measurements, Automatic Gain Control (AGC), and beam management on the dormant BWP, if configured to do so. For each serving cell other than the SpCell or PUCCH SCell, the network may configure one BWP as a dormant BWP.

[0050] For each SCell, dormantBWP-Id may be set to a dormant BWP by RRC signaling as described in TS38.331. The transition of an SCell to or from a dormant BWP is performed by BWP switching per SCell or per dormant SCell group based on an indication from the PDCCH (as specified in TS38.213). Dormant SCell group configuration is configured by RRC signaling as described in TS38.331. Upon reception of a PDCCH indicating a transition from a dormant BWP, the DL BWP indicated by firstOutsideActiveTimeBWP-Id or firstWithinActiveTimeBWP-Id (specified in TS38.331 and TS38.213) is activated. Upon reception of a PDCCH indicating a transition to a dormant BWP, the DL BWP indicated by dormantBWP-Id (specified in TS38.331) is activated. Dormant BWP configuration for SpCell or PUCCH SCell is not supported. Further details on BWP operation are given in section 5.15 of 3GPP TS38.321v16.6.0.

[0051] Switching between configured BWPs can be realized in various ways. The operation of the bandwidth parts in the uplink and downlink is defined, for example, in the 5G NR compliant implementation of 3GPP 38.321 v16.6.0 section 5.15. The BWP can be switched, for example, using the downlink control information (DCI) (e.g., using the bandwidth part indicators in DCI format 0_1 ​​(UL grant) and DCI format 1_1 (DL schedule)), using the bwp-inactivity Timer, using RRC signaling, and by the MAC entity itself at the start of the random access procedure. For a primary cell (PCell), the initial BWP is the BWP used for initial access, and the default BWP is the initial BWP unless another initial BWP is explicitly configured. For a secondary cell (SCell), the initial BWP is always explicitly configured and a default BWP may also be configured. If a default BWP is configured for the serving cell, the active BWP is switched to the default BWP when the inactivity timer associated with that cell expires.

[0052] Some DCI formats do not include a BWP ID (e.g., formats 0_0 and 1_0), while in other DCI formats the number of bits for the BWP ID is configurable by the RRC and can be 0, 1 or 2 bits (e.g., for formats 0_1, 0_2, 1_1, and 1_2).

[0053] Figure 6 shows a scenario in which three different BWPs are configured: BWP1 with a frequency bandwidth of 40 MHz and a subcarrier spacing of 15 kHz, BWP2 with a width of 10 MHz and a subcarrier spacing of 15 kHz, and BWP3 with a width of 20 MHz and a subcarrier spacing of 60 kHz.

[0054] The various BWPs may be configured, for example, using appropriate information elements of the RRC protocol.

[0055] A carrier bandwidth part is a contiguous set of physical resource blocks selected from a contiguous subset of common resource blocks for a given numerology (u) on a given carrier.

[0056] More specifically, according to an example of a 5G NR compatible implementation in line with 3GPP 38.331v16.6.0, the following RRCReconfiguration information elements can be used:

[0057] The RRC parameters for BandwidthPart Configuration are described in TS38.331 and include at least initialDownlinkBWP, firstActiveDownlinkBWP-Id, defaultDownlinkBWP-Id, bwp-InactivityTimer, initialUplinkBWP, firstActiveUplinkBWP-Id, BWP-Id, locationAndBandwidth, subcarrierSpacing, etc.

[0058] Specifically, the information element (IE) BWP-Uplink is used to configure an additional uplink BWP (rather than the initial BWP). The BWP-Uplink may define common (e.g., cell-specific) parameters of the uplink bandwidth part (BWP-UplinkCommon IE) or dedicated (e.g., UE-specific) parameters of the uplink bandwidth part (BWP-UplinkDedicated IE) and may be identified by a bwp-Id.

[0059] Similarly, the information element BWP-Downlink is used to configure an additional downlink BWP (rather than the initial BWP). BWP-Downlink may define common (e.g. cell-specific) parameters of the downlink bandwidth part (BWP-DownlinkCommon IE) or dedicated (e.g. UE-specific) parameters of the downlink bandwidth part (BWP-DownlinkDedicated IE) and may be identified by a bwp-Id.

[0060] The IE BWP is used to set generic parameters of the BWP, such as the parameters locationAndBandwidth, subcarrierSpacing, and cyclicPrefix.

[0061] The BWP-ID IE is used to reference different BWPs: the initial BWP is referenced by BWP-Id 0, the other BWPs are referenced by BWP-Id 1 to the maximum number of BWPs.

[0062] The DownlinkConfigCommon IE and the DownlinkConfigCommonSIB IE can define an initial DL BWP using the above-mentioned IE BWP-DownlinkCommon. Similarly, the UplinkConfigCommon IE and the UplinkConfigCommonSIB IE can define an initial UL BWP using the above-mentioned IE BWP-UplinkCommon.

[0063] The ServingCellConfig IE is used to configure the serving cell for the UE, and the aforementioned BWP-DownlinkDended IE can be used to define the initial downlink BWP.

[0064] The ServingCellConfig IE can also define a default downlink BWP by indicating a suitable BWP-ID among the configured BWPs. Similarly, the ServingCellConfig IE can also define an initial active downlink BWP by indicating a suitable BWP-ID among the configured BWPs. The ServingCellConfig IE can also define a bwp-inactivity timer value, which is used as a possible mechanism for the UE to revert to the default BWP upon expiration of the timer.

[0065] The ServingCellConfig IE can define a dormant BWP using a dormantBWP-Config-r16 IE that indicates the BWP ID.

[0066] Control information - Search space set PDCCH monitoring is performed by the UE to identify and receive information intended for the UE, such as control information and user traffic (eg, DCI on the PDCCH and user data on the PDSCH indicated by the PDCCH).

[0067] Downlink control information (which may be referred to, for example, as downlink control information DCI) has essentially the same purpose in 5G NR as DCI in LTE, i.e., it is a set of special control information that schedules a downlink data channel (such as PDSCH) or an uplink data channel (such as PUSCH). In an exemplary 5G NR compliant implementation, there are several different predefined DCI formats (see TS38.212v16.7.0 section 7.3.1). An overview is shown in the table below. [Table 1]

[0068] In addition to the DCI formats listed above, a new DCI format 2_7 has just been defined and may be agreed upon and included in further 3GPP standard specifications. DCI format 2_7 is intended to be used to signal paging early indication and TRS availability indication. The following agreement on the new DCI format 2_7 is provisional and subject to change.

[0069] 7.3.1.3.8 Format 2_7 DCI format 2_7 is used to inform one or more UEs of the paging early indication and the TRS availability indication. The following information is transmitted using DCI format 2_7 with CRC scrambled by the PEI-RNTI:

[0070] The bit(s) of the paging indication field can be expressed by Equation 1.

number

number

number

number

[0071] If subgroupsNumPerPO is set and not set to 0, then each bit in this field indicates one UE subgroup for a paging occasion, otherwise each bit in this field indicates a UE group for a paging occasion.

[0072] - TRS Availability Indication - 1, 2, 3, 4, 5, or 6 bits if TRS-ResourceSetConfig is set, 0 bit otherwise.

[0073] The size of DCI format 2_7 is indicated by the higher layer parameter payloadSizeDCI_format2_7 according to clause 10.4A of [5, TS38.213]. If the number of information bits of format 2_7 is less than the size of format 2_7, the remaining bits are reserved.

[0074] In 5G NR, the PDCCH is transmitted in a radio resource region called the control resource set (CORESET). In LTE, the concept of a CORESET does not exist explicitly. Instead, the LTE PDCCH uses the entire carrier bandwidth in the first 1-3 OFDM symbols (4 in the narrowest case). In contrast, the 5G NR CORESET can be anywhere in the slot and anywhere within the frequency range of the carrier, except that a UE is not expected to handle a CORESET outside its active bandwidth part (BWP).

[0075] Thus, the UE performs a PDCCH monitoring operation, for example as defined in 3GPP TS38.213 version 16.7.0, sections 10 and 11. As exemplarily defined therein, the UE monitors a set of PDCCH candidates defined in units of a PDCCH search space set. The search space set can be a common search space set (CSS) or a UE-specific search space set (USS).

[0076] The search space sets in one or more CORESETs on the active DL BWP in each activated serving cell configured for PDCCH monitoring using the corresponding search space set are monitored, where monitoring means decoding each PDCCH candidate according to the monitored DCI format.

[0077] Conceptually, Figure 6 provides an exemplary diagram of the relationship between bandwidth parts, CORESETs, search spaces, search space sets, and PDCCH candidates that a UE can monitor. As is evident from Figure 6, one CORESET is shown per BWP, but more than one is possible. Each CORESET can then have several search spaces of one or more PDCCH candidates of a particular aggregation level (e.g., AL2, 4, or 8), which can be grouped into search space sets, e.g., common SS sets and UE-specific SS sets.

[0078] <Search Space Set Group Switching> In 3GPP, the concept of configuring at least two groups of search space sets (abbreviated as SSS or SS set) for monitoring the PDCCH has been discussed. This concept may be particularly useful for operation in unlicensed radio spectrum, for example, where the gNB must first acquire a channel before it can transmit the PDCCH. For example, different SSS groups may differ depending on when and / or how long the UE needs to monitor the PDCCH during a slot.

[0079] Different groups may contain different search space sets, and one search space set may be part of more than one SSS group.

[0080] According to one exemplary aspect of this concept, the UE can be configured to switch groups. One particular exemplary implementation of search space set switching is defined in the 3GPP specifications for 5G NR, specifically TS38.213v16.7.0, section 10.4 "Search space set group switching."

[0081] <Time domain in 5G NR> In the time domain, 5G NR transmissions are organized into frames of length 10 ms, each of which is divided into 10 equally sized subframes of length 1 ms. In turn, the subframes are divided into one or more slots, each of which consists of 14 OFDM symbols. The duration of the slots in milliseconds varies depending on the numerology. Thus, for example, for a subcarrier spacing of 15 kHz, an NR slot has the same structure as an LTE subframe with a normal cyclic prefix. The 5G NR subframe serves as a numerology-independent time reference, which is particularly useful when multiple numerologies are mixed on the same carrier, whereas the slot is the typical unit of dynamic scheduling. This frame structure, which is the basis of 3GPP 5G NR communication, is exemplarily shown in Figure 7.

[0082] 5G NR offers multiple slot formats, where a slot format indicates how each symbol in a single slot is used. The slot format defines which symbols in a particular slot are used for the uplink and which symbols are used for the downlink. In LTE TDD, if a subframe (corresponding to a slot in NR) is configured for DL ​​or UL, all symbols in the subframe must be used as DL or UL. However, in NR, each symbol in a slot can be configured differently as DL or UL. There are also flexible symbols that can be configured as DL or UL. In an exemplary 5G NR compliant implementation, the gNB uses a slot format indicator (SFI) to inform the UE about the slot format to be used (see also TS38.213v16.7.0 section 11.1.1). For example, the slot format indicator includes an index value associated with the slot format (e.g., in a table format).

[0083] The following table illustrates, by way of example, how each OFDM symbol in a slot can be defined as a downlink (D), uplink (U), or flexible (F) OFDM symbol. [Table 2]

[0084] Synchronization signal block measurement timing configuration SMTC (Synchronization Signal Block measurement timing configuration)-PSS / SSS, PBCH

[0085] In NR, the so-called synchronization signal block (SSB, SS block) is introduced, which contains the Primary Synchronization Signal (PSS, SSS), the Secondary Synchronization Signal (SSS, SSS), and the Physical Broadcast Channel (PBCH, PBCH DMRS and PBCH data). The PSS and SSS can be used by the UE to discover, synchronize to, and identify the network. The PBCH carries minimal system information, including an indication of where the rest of the broadcast system information is transmitted.

[0086] In LTE, these three signals, PSS, SSS, and PBCH, were also used, but not as part of one SSB. In NR, the three SSB components are always transmitted together, e.g., they have the same periodicity. A given SSB may be repeated within an SS burst set, and the SS burst set may be used for gNB beam sweep transmissions. The SS burst set may be limited to a specific period, such as a 5 ms window (half frame). For initial cell selection, the UE may assume a default SS burst set periodicity of 20 ms.

[0087] 5G NR PSS is a physical layer specific signal for identifying radio frame boundaries and is a type of m-sequence. 5G NR SSS is a physical layer specific signal for identifying subframe boundaries and is also an m-sequence. PSS / SSS sequences are defined in 3GPP TS38.212 and consist of complex values ​​used for each element / sample of the sequence. Information regarding current exemplary 5G implementations of PSS and SSS, including the generation of the respective sequences and their mapping to physical resources, can be found in TS38.211v16.7.0 sections 7.4.2 and 7.4.3.

[0088] The time-frequency structure of the SS / PBCH block carrying the SSS is described in TS38.211 section 7.4.3.1. In such an exemplary 5G implementation, in the time domain, the SS / PBCH block consists of four OFDM symbols numbered in ascending order from 0 to 3. The placement of the PSS, SSS, and PBCH signals within the SS / PBCH block is defined in Table 7.4.3.1-1.

[0089] In the frequency domain, an SS / PBCH block consists of 240 contiguous subcarriers indexed from 0 to 239. The exact subcarriers used for each PSS, SSS, and PBCH signal within the SS / PBCH block are also defined in Table 7.4.3.1-1.

[0090] A simplified exemplary diagram of an SSB according to the above definition is shown in FIG. 8, which shows the PSS, SSS, and PBCH in the time and frequency domain at the bottom.

[0091] The timing (OFDM symbols) at which the SS block (see FIG. 8) is transmitted by the gNB can be defined differently. Specifically, the first symbol index (within each half frame containing an SSB) at which the candidate SSB begins is determined according to 3GPP38.213v16.7.0, section 4.1 “Cell search”. In this exemplary 5G NR implementation, the first symbol index varies depending on the SCS (e.g., 15 kHz, 30 kHz, 120 kHz, 240 kHz), the type of channel access (e.g., without shared spectrum channel access, with shared spectrum channel access), and the carrier frequency (e.g., below 3 GHz, above 3 GHz, below 1.88 GHz, above 1.88 GHz, below 6 GHz, above 6 GHz). Exemplary sets of SSBs are shown in Figure 8, assuming starting OFDM symbols are 2, 8, 16, 22, 30, 36, 44, and 50 (for SCS = 30 kHz, frequencies > 3 GHz), where the numbering of OFDM symbols starts from 0 within a half frame. The number of SSBs in a set of SSBs may also be limited to a maximum of Lmax. In one example, an SSB set may include 4, 8, or 64 SSBs.

[0092] The time domain periodicity can be defined in the ServingCellConfigCommon or ServingCellConfigCommon SIB IE using the field ssb-periodictyServingCell between the values ​​ms5, ms10, ms20, ms40, ms80, ms160.

[0093] The candidate SS / PBCH blocks in a half-frame (e.g., called the set of SSBs) are indexed in ascending time order from 0 to Lmax-1. Correspondingly, each SSB in the set of SSBs is assigned a unique number (starting at 0 and incrementing by 1).

[0094] The SSB set described above in FIG. 8 illustrates the case where all possible candidate SSBs are actually transmitted by the base station. However, it is not necessary to transmit all SSBs. Rather, the gNB may select and transmit only a portion of those SSBs in the set of SSBs based on some requirements. The SSBs actually transmitted by the SSBs may also be referred to as SSB patterns. An SSB pattern essentially has the same properties as the corresponding set of SSBs, including periodicity.

[0095] The gNB informs the UE of the SSB pattern, i.e. which SSBs are actually transmitted and which are not, for example by the gNB transmitting an SSB bitmap that defines the SSB pattern.

[0096] The length of the SSB bitmap depends on the relevant SSB set, e.g., 4, 8 or 64 bits.

[0097] According to one exemplary option, the information element ssb-PositionsInBurst of the RRC protocol can be transmitted as part of the ServingCellConfigCommon and ServingCellConfigCommonSIB information elements (see 3GPP TS38.331v16.6.0, section 6.3.2). The ssb-PositionsInBurst IE indicates the time domain positions of the transmitted SSBs within the SS burst. A bitmap can be used for the indication, e.g. {1,1,1,1,1,1,1,1,1} meaning that all 8 SSBs of the set are transmitted, or {1,0,1,0,1,0,1,0} meaning that only 4 SSBs out of 8 are transmitted, specifically SSB indexes #0,2,4,6.

[0098] Two examples are provided below.

number

[0099] Among the SSBs defined in the different bandwidth parts, one of them is defined as a cell-defined SSB, which is an SSB associated with a Remaining Minimum System Information (RMSI).

[0100] Simply put, a set of candidate SSBs is configured by the gNB to be used in the cell. Furthermore, from the set of candidate SSBs, the gNB can select all or fewer candidate SSBs to actually transmit, called an SSB pattern.

[0101] In one example, the transmit power used by the gNB for SSB transmissions can be signaled to the UE by the higher layer parameter ss-PBCH-BlockPower described in TS38.331, which defines the average EPRE (Energy per Resource Element) in dBm of resource elements carrying secondary synchronization signals used by the gNB for SSB transmissions (see also TS38.213, clause 7). The UE assumes that the SSS, PBCH DM-RS, and PBCH data have the same EPRE. The UE may assume that the ratio of PSS EPRE to SSS EPRE in the SS / PBCH block is either 0 dB or 3 dB.

[0102] All SSBs can be transmitted in all beams in the system. Alternatively, the SSBs can be transmitted in different beams, such as when SSB beamforming is enabled. In that case, as shown in FIG. 9, each SSB is transmitted in a different spatial beam. Similar to the exemplary assumption in FIG. 8, there are eight SSBs (0-7) that can be transmitted in different beams, each beam being transmitted in a different beam direction. Thus, a beam-sweep type transmission of SSBs is realized, in other words, the sweep transmission of beams (and SSBs) is time-division multiplexed and occurs at different times. Two UEs, UE1 and UE2, receive different SSBs at different times. Each beam has a beam index, e.g., the beam index corresponds to the SSB index transmitted through that beam.

[0103] The UE uses the SSB, and in particular the SSB signals (eg, PSS, SSS, PBCH), for various mechanisms, such as, for example, serving cell measurements, time / frequency synchronization, and so on.

[0104] <Reference signal> In 5G NR, several different types of reference signals (RS) are used (see 3GPP TS38.211v16.7.0 section 7.4.1). At least the following reference signals are available in 5G NR: · CSI-RS, or Channel State Information Reference Signal, which can be used to obtain channel state information and manage beams PDSCH DMRS that can be used for PDSCH demodulation, i.e. Demodulation Reference Signal PDCCH DMRS that can be used for PDCCH demodulation, i.e. Demodulation Reference Signal PBCH DMRS, i.e., Demodulation Reference Signal, that can be used for PBCH demodulation PTRS, i.e. Phase Tracking Reference Signal, that can be used for phase tracking of the PDSCH Tracking reference signals that can be used for time tracking, also known as "CSI-RS for tracking" (see TS38.214) ·RIM reference signal Positioning reference signal

[0105] As a DL-only signal, the CSI-RS received by the UE can be used by the UE to estimate the channel and report channel quality information to the gNB (assisting in modulation and coding scheme selection, resource allocation, beamforming, and MIMO rank selection by the gNB). The CSI-RS can be configured for periodic, aperiodic (e.g., triggered by DCI), or semi-persistent transmission with configuration density by the gNB. The CSI-RS can also be used for interference measurement (IM) and detailed frequency / time tracking purposes. Specific instances of the CSI-RS can be configured for time / frequency tracking and mobility measurements. During MIMO operation, NR may use different antenna approaches based on carrier frequency. At lower frequencies, the system uses fewer active antennas for MU-MIMO and adds FDD operation. In this case, the UE may use the CSI-RS to calculate CSI and report CSI in the UL direction.

[0106] Although CSI-RS is UE-specific, multiple users can share the same CSI-RS resources. Specifically, UE-specific configuration of CSI-RS does not necessarily mean that the transmitted CSI-RS can only be used by a single device, but rather that the same set of CSI-RS resources can be configured individually for multiple devices, which means that a single CSI-RS can be shared among multiple devices.

[0107] For example, a single-port CSI-RS occupies a single resource element in a resource block in the frequency domain and one slot in the time domain. Although the CSI-RS can be configured to occur anywhere in the resource block, in practice some restrictions can be imposed on the allocation of CSI-RS resources to avoid collisions with other downlink physical channels and signals. As an example, the transmission of the configured CSI-RS can be such that it does not collide with the DM-RS associated with the CORESET, PDSCH transmissions and SS block transmissions configured for the device.

[0108] The 5G NR standard supports flexible CSI-RS configuration: in the time domain, a CSI-RS resource may start at any OFDM symbol of a slot and span, for example, one, two or four OFDM symbols depending on the number of configured antenna ports.

[0109] The Tracking Reference Signal (TRS) is a further reference signal that can be used to synchronize time and / or frequency with the gNB. Detailed information on the TRS based on the current 5G definition is given in TS38.331v16.6.0, section 6.3.2, specifically in the information element NZP-CSI-RS-ResourceSet. Further information on the TRS can be taken from TS38.214v16.7.0, section 5.2.2.3.1 "NZP CSI-RS". Furthermore, TS38.214v16.6.0 section 5.1.6.1.1 specifies conditions on how multiple CSI-RS are grouped into a TRS and restrictions on the configuration of each CSI-RS grouped into a TRS.

[0110] According to an example, system information signaling (e.g., one of the system information blocks) may provide configuration of TRS and / or CSI-RS opportunity(s) for idle and / or inactive UE(s). In addition to system information, other signaling methods for configuring TRS / CSI-RS opportunities may also be supported, such as dedicated RRC messages, such as RRC release messages.

[0111] In one exemplary 5G NR implementation, a table (see, e.g., TS38.211, table 7.4.1.5.3-1) defines a set of candidate CSI-RS configurations, where each candidate CSI-RS configuration defines a set of resource elements (in slots) on which reference signals are transmitted. Different CSI-RS configurations differ from each other, e.g., in number of ports, density, and / or cdm type (code division multiplexing type). The gNB can inform the UE which CSI-RS it is currently transmitting using the IE CSI-RS-ResourceMapping, which sets the resource element mapping of CSI-RS resources in the time and frequency domains.

[0112] <Network energy saving considerations> As part of the global trend to reduce the environmental impact of Information and Communication Technology (ICT) equipment and the continuing desire of network operators to reduce operational costs, 3GPP has been working for many years on developing standards for energy efficiency in mobile networks.

[0113] Energy savings may be implemented in the UE including the following mechanisms: UE-specific BWP adaptation and use of dormant SCells (using DCI format 0_1 ​​(for UL) and DCI format 1_1 (for DL)) UE or UE group specific time domain adaptation by DRX using DCI format 2_6 TRS availability indication for IDLE / INACTIVE UEs with UE group specific CSI-RS / DCI format 2_7 and paging DCI-based PDCCH monitoring adaptation with PDCCH skipping and SSSG (Search Space Set Group) switching

[0114] 3GPP is currently looking into network energy savings for Release 18 and has concluded that network energy consumption models, KPIs and evaluation methods need to be considered and developed, and network energy saving techniques need to be identified and considered in targeted deployment scenarios. This should investigate how to achieve more efficient operation dynamically and / or semi-statically in one or more of the network energy saving techniques in time, frequency, space and power domains, and achieve finer granularity adaptation of transmission and / or reception, with possible support / feedback from the UE, possible UE assistance information and information exchange / coordination over the network interface.

[0115] This study item aims to explore and identify gNB-side and UE-side techniques to improve network energy savings for both BS transmission and reception [RAN1, RAN2, RAN3, [RAN4]]. Idle / empty and low / medium load scenarios should be prioritized in this study (the exact definition of such loads is left to this study).

[0116] One goal is to enable legacy UE to continue to access networks that implement Rel-18 network energy saving techniques, with the possible exception of technologies developed specifically for greenfield deployments.

[0117] To achieve network energy savings, dynamic network-level radio resource adaptation is an important part of the Rel.18 study. For gNBs to perform network-level resource adaptation, the new features are: Supports L1-based instructions for dynamic traffic adaptation. Semi-static adaptation is also possible. Enable dynamic time, frequency, space, and / or power domain adaptation using a unified framework to improve efficiency. Each domain adaptation can operate independently or in conjunction with each other. · May support cell-specific or UE group level indication to reduce control overhead. · May support both DL and UL adaptation when gNB transmission and reception are both within the SID scope.

[0118] <Further improvements> Above is a brief overview of network energy saving considerations in 3GPP Release 18. The inventors have identified the need to support cell-level or UE group specific dynamic adaptation mechanisms for network energy saving mechanisms in one or more of frequency, time and space domains. The mechanisms currently available in 3GPP standards for enabling energy savings are not well suited to realizing energy savings on the network side.

[0119] The inventors have thus identified the possibility of providing an improved adaptation procedure for the adaptation of operations between UE(s) and a base station, which makes it possible to avoid or mitigate one or more of the problems identified above and in particular to save energy on the network side. The present invention relates to various solutions and variants for such an improved adaptation procedure.

[0120] <Embodiment> In the following, UEs, base stations, and respective procedures that meet these needs are described for new radio access technologies envisioned for 5G mobile communication systems, but which may also be used in previous LTE mobile communication systems or future mobile communication systems. Various implementations and variations are described as well. The following disclosure is facilitated by, and may be based, for example, at least in part on, the discussion and insights presented above.

[0121] In general, it should be noted that many assumptions have been made herein and will be made below in order to enable the principles underlying the present disclosure to be explained in a clear, concise and understandable manner. However, these assumptions should be understood as examples made herein for illustrative purposes only, and are not necessarily essential to the present invention, and therefore do not limit the scope of the present disclosure. Those skilled in the art will realize that the principles of the following disclosure and claims can be applied in different scenarios and in ways not explicitly described herein.

[0122] Furthermore, some of the terms such as procedures, entities, layers, etc. used below are closely related to the terms used in the LTE / LTE-A system or the current 3GPP 5G standardization, but the specific terms used in the context of new radio access technologies for the upcoming 3GPP 5G communication system have not yet been fully determined or may eventually be changed. Thus, the terms may be changed in the future without affecting the functionality of the embodiments. Therefore, those skilled in the art will recognize that the scope of the embodiments and their protection should not be limited to the specific terms used illustratively herein due to the lack of newer or finally agreed terms, but should be more broadly understood with respect to the functions and concepts underlying the solutions described in this disclosure.

[0123] For example, a mobile station or mobile node or user terminal or user equipment (UE) is a physical entity (physical node) in a communication network. A node may have several functional entities. A functional entity refers to a software or hardware module that implements and / or provides a predefined set of functions to other functional entities of the same or another node or network. A node may have one or more interfaces that attach the node to a communication facility or medium that allows the node to communicate. Similarly, a network entity may have logical interfaces that attach a functional entity to a communication facility or medium that allows the node to communicate with other functional entities or corresponding nodes.

[0124] The term "base station" or "radio base station" in this specification refers to a physical entity in a communication network. Similar to a mobile station, a base station may have several functional entities. A functional entity refers to a software or hardware module that implements and / or provides a predefined set of functions to other functional entities of the same or another node or network. A physical entity performs several control tasks for a communication device, including one or more of scheduling and configuration. Note that the base station functionality and the communication device functionality may be integrated in a single device. For example, a mobile terminal may also implement the base station functionality for other terminals. The term used in LTE is eNB (or eNodeB), while the term currently used for 5G NR is gNB.

[0125] Communications between a UE and a base station are typically standardized and may be defined by different layers, such as, for example, PHY, MAC, RRC, etc. (see background discussion above).

[0126] 10 shows a general, simplified, exemplary block diagram of a user equipment (also called a communication device) and a scheduling device (here assumed, for illustrative purposes, to be located in a base station such as an LTE eNB (aka ng-eNB) or a gNB in ​​5G NR). The UE and the eNB / gNB communicate with each other via (wireless) physical channels using their respective transceivers.

[0127] The communication device may include a transceiver and a processing circuit. The transceiver may include a receiver and a transmitter and / or may function as a receiver and a transmitter. The processing circuit may be one or more hardware, such as, for example, one or more processors or any LSI. There is an input / output point (or node) between the transceiver and the processing circuit, through which the processing circuit can control the transceiver during operation, i.e., control the receiver and / or the transmitter to exchange receive / transmit data. The transceiver may include an RF (radio frequency) front, including one or more antennas, amplifiers, and RF modulators / demodulators, as a transmitter and receiver. The processing circuit may perform control tasks, such as, for example, controlling the transceiver to transmit user data and control data provided by the processing circuit and / or to receive user data and control data that are further processed by the processing circuit. In addition, the processing circuit may be responsible for performing other processes, such as, for example, judgment, decision, calculation, measurement, etc. The transmitter may be responsible for performing the process of transmission and other processes related thereto. The receiver may be responsible for performing the process of reception and other processes related thereto, such as monitoring the channel.

[0128] Various solutions of the improved adaptation procedure are described below. In this connection, an improved UE, an improved base station, and an improved integrated circuit that participate separately or together in the improved adaptation procedure are presented. Corresponding methods for the UE operation and the base station operation are also provided. The integrated circuits correspond to the UE and the base station and their respective operations.

[0129] Figure 11 shows a simplified exemplary UE structure with an exemplary implementation of the improved adaptation procedure, which may be implemented based on the general UE structure described in relation to Figure 10. The various structural elements of the UE shown in this Figure 11 may be interconnected with each other, e.g., by corresponding input / output nodes (not shown), e.g., for exchanging control and user data and other signals. Although not shown for illustrative purposes, the UE may include further structural elements.

[0130] As is clear from Figure 11, the UE may include a control signal receiver and an operation adaptation circuit. According to various solutions shown below, the operation adaptation may relate to one or more of BWP operation, SSB operation, RS operation, time domain operation, PDCCH monitoring operation, and search space set operation.

[0131] Thus, in the present case, as will become apparent from the disclosure below, the UE receiver may be exemplarily configured to at least partially perform one or more of the following: receive control signals such as BWP control signals, SSB control signals, RS control signals, time domain control signals, PDCCH adaptation control signals, etc.

[0132] Thus, in the present case, as will become apparent from the disclosure below, the processing circuitry of the UE may be exemplarily configured to at least partially perform one or more of: determining operational parameters from received control signals; and operating in accordance with the determined operational parameters.

[0133] Thus, in the present case, as will become apparent from the disclosure below, the transmitter of the UE may be exemplarily configured to at least partially perform one or more of the following: transmit data to a base station.

[0134] One exemplary procedure, disclosed in further more detail below, is implemented by a UE, which includes: a receiver of the UE receives a first control signal from a base station, the first control signal being common to a radio cell to which the UE belongs or a group of UEs, the first control signal indicating an operating target bandwidth part BWP, and a processing circuit of the UE operates according to the indicated target BWP.

[0135] A corresponding exemplary method is performed by a UE: receiving a first control signal from a base station, the first control signal being common to a radio cell to which the UE belongs or to a group of UEs, the first control signal indicating an operating target bandwidth part BWP; operating according to the indicated target BWP; Includes.

[0136] A sequence diagram corresponding to an exemplary UE operation in accordance with the UE and UE methods discussed above is shown in Figure 12. As can be seen from Figure 12, the UE receives the control signal and then determines the operation parameters therefrom. The UE subsequently operates in accordance with the determined operation parameters, e.g., according to the indicated BWP, SSB, RS, blanking period, PDCCH skip, and target SSS group, as described below in various solutions.

[0137] In this way, the improved adaptation procedure described above achieves the objectives and overcomes some of the drawbacks described above. Specifically, the UE can appropriately process cell-wide or UE group-wide control signals from the base station to operate according to the operating parameters determined by the base station, thereby promoting network energy savings.

[0138] Some exemplary implementations of the improved adaptation procedure also involve the base station to which the UE is currently connected (e.g., called the serving base station because the base station serves the UE), and correspondingly, the improved adaptation procedure also provides for improved base stations to participate therein.

[0139] Fig. 13 shows a simplified exemplary base station structure with an exemplary implementation of the improved adaptation procedure, which may be implemented based on the general base station structure described in connection with Fig. 10. The various structural elements of the base station shown in this Fig. 13 may be interconnected with each other, e.g., by corresponding input / output nodes (not shown), e.g., for exchanging control and user data as well as other signals. Although not shown for illustrative purposes, the base station may include further structural elements.

[0140] As can be seen from Fig. 13, the base station includes a control signal transmitter, an operation parameter determination circuit, and an operation adaptation circuit. According to various solutions presented below, the operation adaptation and the operation parameters may be related to one or more of BWP operation, SSB operation, RS operation, time domain operation, PDCCH monitoring operation, and search space set operation.

[0141] Thus, in the present case, as will become apparent from the disclosure below, the base station receiver may be exemplarily configured to at least partially perform one or more of: receiving data from the UE;

[0142] Thus, in the present case, as will become apparent from the disclosure below, the base station's processing circuitry may be exemplarily configured to at least partially perform one or more of: determining operating parameters; and adapting its own operation to the determined operating parameters.

[0143] Thus, in the present case, as will become apparent from the disclosure below, the base station transmitter may be exemplarily configured to at least partially perform one or more of the following: transmit control signals such as a BWP control signal, an SSB control signal, an RS control signal, a time domain control signal, a PDCCH adaptation control signal, etc.

[0144] One exemplary procedure, disclosed in further more detail below, is implemented by a base station including: a processing circuit of the base station determines an operational target bandwidth part BWP; a transmitter of the base station transmits a first control signal to all UEs or a group of UEs in a radio cell, the first control signal being common to the radio cell or the group of UEs and indicating the target BWP; and a processing circuit operates according to the indicated target BWP.

[0145] The corresponding method is performed by a base station, determining an operational target bandwidth part BWP; transmitting a first control signal to all UEs or a group of UEs in a radio cell, the first control signal being common to the radio cell or the group of UEs and indicating a target BWP; operating according to the indicated target BWP; Includes.

[0146] A sequence diagram corresponding to an exemplary base station operation in accordance with the base station and corresponding method discussed above is shown in FIG. 14. This sequence diagram illustrates an exemplary simplified implementation of the base station method presented above. As is evident from FIG. 14, the base station determines operating parameters, and then generates and transmits appropriate control signals to the UE(s) to indicate the determined operating parameters. The base station (corresponding to the UE) operates according to the determined operating parameters indicated to the UE.

[0147] FIG. 15 illustrates a simplified exemplary interaction between an improved UE and an improved base station (here, for example, a gNB) of the improved adaptation procedure discussed above. In this solution illustrated in FIG. 15, this interaction first involves the determination of operating parameters under the control of the base station. A control signal indicating the operating parameters is transmitted from the base station to the UE (for example, a group of UEs or all UEs in a radio cell). Both the UE and the base station then subsequently operate according to the indicated operating parameters.

[0148] In the following, more specific implementations and variations of the operations discussed above are described, both from the perspective of the UE and the base station, and various solutions are presented to enable energy savings on the network side in various time, frequency and spatial domains.

[0149] In summary, according to the first solution, network energy savings are promoted by adapting frequency domain operations between the UE and the base station, in particular by adapting the bandwidth parts used between the UE and the base station. According to the second solution, network energy savings are promoted by adapting spatial domain operations between the UE and the base station, in particular by adapting the SSBs and / or reference signals (RS) used between the UE and the base station. According to the third solution, network energy savings are promoted by adapting time domain operations between the UE and the base station, in part by defining blank periods during which the UE and the base station are allowed to skip some operations. According to the fourth solution, network energy savings are promoted by adapting downlink control channel related operations between the UE and the base station, in particular by skipping downlink control channel operations and / or by switching to a different SSS group.

[0150] First, the four solutions are described as standalone solutions, and one or more of these four solutions can be implemented individually and independently of each other. In other words, the UE and the base station can implement one, more than one, or all of the four solutions.

[0151] However, it is also possible to implement two, more than two or all of the four solutions in combination to obtain synergistic effects, which will be described as part of a further solution, which we will call the fifth solution.

[0152] <First solution - Frequency domain - BWP adaptation> According to this first solution, network energy savings are promoted by adapting the frequency domain operation between the UE and the base station, specifically by adapting the bandwidth part used between the UE and the base station. This improved BWP adaptation procedure is under the control of the base station, which is responsible for determining the operational target BWP and informing the UE accordingly.

[0153] Specifically, the base station intends to adapt the entire system bandwidth, for example by reducing the system bandwidth, in order to save energy. For this purpose, the base station determines a target bandwidth part to be indicated to the UE.

[0154] Which BWP the base station decides to use as the target BWP may depend on various criteria. For example, the base station may take into account the current traffic situation with the UEs in its radio cell, the targeted energy savings on the network side, the current BWP settings of the UEs in the base station's radio cell, or other criteria. For example, depending on system-level throughput estimates, required spectral efficiency, number of UEs served, etc., the gNB may decide to operate a relatively wide or narrow BWP to adapt to the traffic and save energy where possible.

[0155] Specifically, the UEs in the radio cell of the base station operate according to the bandwidth parts previously set for the UEs. Therefore, the currently active BWP in the BWP may be different among various UEs, or may be overlapped or the same for some UEs. For example, from the perspective of each UE, the currently active BWP may be the initial BWP, default BWP, dormant BWP, or common BWP set for that particular UE.

[0156] According to the improved BWP adaptation procedure, the resulting target bandwidth part is: · Default BWP configured in the UE, Initial BWP configured in the UE, Dormant BWP configured in the UE, The first non-dormant BWP configured in the UE, A common BWP configured in the UE, which is common to all UEs in the base station's radio cell or common to a group of UEs; The above-mentioned embodiment may be any one of the above.

[0157] The various BWPs listed above as candidates for the target BWP may be pre-configured for the UE by the base station.

[0158] When the UE receives a BWP control signal indicating an operating target BWP, the UE subsequently operates according to this target BWP instead of the currently active BWP. In one example, the UE's operation may include a check to determine the currently active BWP. If the indicated target BWP is indeed different from the currently active BWP, the UE switches its operation to the indicated target BWP. Otherwise, i.e., if the currently active BWP is the same as the target BWP, the UE does not need to perform an actual switch and can continue its current BWP operation.

[0159] Thus, the UE and base station subsequently operate based on the target BWP, including performing BWP-related functions based on the target BWP (rather than the previously active BWP). The BWP-related functions may include random access procedures or monitoring a downlink control channel (e.g., PDCCH).

[0160] Correspondingly, the base station and all UEs (or a group of UEs) within the base station's radio cell operate according to a target BWP (eg, a common BWP) to enable the base station to save network energy.

[0161] Figure 16 shows the active BWPs before and after target BWP adaptation for three UEs, UE1-UE3, and the resulting system bandwidth. As is clear from Figure 16, the BWPs of the three UEs together occupy the system bandwidth, which the base station operates using. The three UEs may be all UEs in the cell of the base station, in which case the BWP control signal may be a cell-common BWP control signal to reach the three UEs. Alternatively, the three UEs may belong to the same UE group, and the required BWP control signal may be common to that UE group, i.e., UE1-UE3.

[0162] It is exemplarily assumed that the target BWP indicated by the BWP control signal of the first solution is one of the default BWP, the initial BWP, or the dormant or first dormant BWP pre-configured in the UE, respectively. For example, after receiving the BWP control signal, UE1 switches to its own default BWP shown in Figure 16, UE2 switches to its own default BWP shown in Figure 16, and UE3 also switches to its own default BWP shown in Figure 16. Since the resulting system bandwidth is narrower than the previous system bandwidth, the base station can operate at a narrower bandwidth and save energy.

[0163] The resulting system bandwidth used by the three UEs depends on the UE-specific configuration of the BWP in the UE, which is indicated as the target BWP by the BWP control signal. The base station pre-configures various BWPs, such as the default BWP, the initial BWP, the dormant BWP, and the common BWP. In the example of FIG. 16 above, it is assumed that the three default BWPs are consecutive with each other and each is narrower than the previous active BWP. However, this is only an example. The three default BWPs may overlap or may not be consecutive. To promote network energy saving, the system bandwidth resulting from the sum of the three target BWPs may be narrower than the previous one.

[0164] Figure 17 is similar to Figure 16, but assumes that the target BWP is a common BWP, e.g., common to all UEs in a radio cell, or common to a group of three UEs as shown. Correspondingly, the three UEs use the same frequency band of the common BWP, which corresponds to the system bandwidth at the base station.

[0165] As mentioned above, the BWP control signal can be common to all UEs of a cell of the base station or common to a group of UEs in the cell of the base station. Compared to UE-specific control of UEs in a radio cell, using such cell-wide or UE-group-wide control signals to adapt frequency domain operations is more efficient and results in less control overhead.

[0166] The base station determines one of the cell-wide or UE group-wide BWP control signals and transmits the BWP control signal within its own radio cell. The base station's decision of whether to transmit the cell-wide or UE group-wide BWP control signal may also depend on the target BWP and which UE the base station should contact to enable energy saving.

[0167] In the above, it is exemplarily assumed that the system bandwidth of the base station is reduced to promote network energy saving. However, the improved BWP adaptation procedure may also include an increase in the system bandwidth, for example when network energy saving functions are reduced or stopped. Correspondingly, in such cases, the base station may configure some or all UEs in its radio cell to operate according to a different BWP than the previously indicated target BWP.

[0168] According to one option, the base station can indicate to each UE individually in a UE-specific manner, for example using signaling already defined in current 3GPP 5G compliance standards, in particular using the bandwidth part indicator in DCI format 0_1 ​​or 1_1.

[0169] According to another option, the BWP control signal according to the improved BWP adaptation procedure of the first solution can also be used to reconfigure the BWP operation of the UE(s). In one example, the base station may determine yet another operational target BWP and provide a BWP control signal to the UE(s) as described above. In that case, the new target BWP may have the same or a wider frequency bandwidth than the previously indicated target BWP.

[0170] In another example, the base station may decide to return the BWP operation to the original BWP of each UE, i.e., the BWP that the UE used before switching to the target BWP. Thus, the cell / UE group common BWP control signal may include an appropriate trigger for each UE to return to the original BWP. The trigger may be, for example, a preset value of the target BWP indicator that is not used to identify the target BWP.

[0171] According to yet another example, the BWP adaptation procedure may also include a UE action of returning to the original BWP after a timer expires. The timer is triggered to start counting from the point when the UE is instructed to use the target BWP. The value of the timer can be set by the gNB via RRC configuration, MAC CE, or DCI.

[0172] In the above, it is assumed that the subsequent action target BWP is indicated to the UE. The following exemplary variant relates to how the target BWP can be indicated by the BWP control signal. In one exemplary variant, the action target BWP can be indicated by a suitable indicator included in the BWP control signal. The target BWP indicator can have one or more bits and identifies the target BWP among the set of BWPs. The number of bits of the target BWP indicator can be defined to be sufficient to clearly distinguish the BWPs in the set.

[0173] The set of BWPs can be pre-configured by the base station using appropriate BWP configuration signaling. Correspondingly, various BWPs can be defined with corresponding BWP IDs. The base station can generate a BWP control signal to include the BWP ID of the determined target BWP as a target BWP indicator. In turn, the UE can determine the corresponding target BWP from the received BWP ID in the set of pre-configured BWPs.

[0174] According to one example, to pre-configure a set of BWPs, a mechanism similar or identical to that described above for a 5G NR compliant implementation may be used, e.g. based on appropriate information elements in RRC signaling.

[0175] The following exemplary variants relate to how the BWP control signal itself can be implemented. In general, the BWP control signal can be a downlink control information DCI message. According to one option, a new DCI message can be defined that includes an appropriate field for carrying the target BWP indication, which is not yet defined in the 3GPP 5G standard.

[0176] Another option is to reuse existing DCI messages to carry the BWP control signals. For example, the existing DCI messages are DCI messages for paging, DCI messages for signaling one or more of slot format and search space set group switching, e.g., DCI messages having a format identical or similar to DCI format 2_0 described above for a 3GPP 5G compliant communication system; DCI messages for reporting power saving information, for example DCI messages having a format identical or similar to DCI format 2_6 described above for a 3GPP 5G compliant communication system; DCI messages for indicating one or more of whether to start monitoring for a paging early control signal and whether a reference signal is available, for example DCI messages having a format identical or similar to DCI format 2_7 described above for a 3GPP 5G compliant communication system; It can be said that:

[0177] When reusing such an existing DCI message, a new field may be added or an existing field may be reused to carry the target BWP indication.

[0178] Alternatively, the BWP control signal can be a message of the radio resource control RRC protocol. For example, if the base station reconfigures the UE to change some of the RRC parameters, the RRC can reconfigure the BWP en masse without any special DCI overhead. As another example, the BWP switching can be done periodically, which can be configurable in the RRC, e.g., the UE stays on BWP#1 for N slots, then switches to BWP#2 and stays for M slots. This does not require additional DCI overhead and allows the gNB to save energy periodically.

[0179] According to yet another alternative, the BWP control signal may be implemented as a control element of a medium access control MAC protocol.

[0180] Furthermore, as explained above, the BWP control signals transmitted by the base station may be common to a cell or to a group of UEs.

[0181] According to a first exemplary variant, the BWP control signal may be addressed to an identifier common to the entire radio cell, and all UEs located within that radio cell may determine that the BWP control signal is intended for them and proceed to process the BWP control signal. In one example, it may be assumed that the BWP control signal is a DCI message, in which case a cell-common identifier (e.g., RNTI) may be used to scramble the DCI message.

[0182] According to a second exemplary variant, the BWP control signal can be addressed to an identifier common to a group of UEs. Since each UE in the group knows the group identifier, the UE determines that the BWP control signal is intended for it and proceeds to process the BWP control signal. In one example, it can be assumed that the BWP control signal is a DCI message, in which case a UE group common identifier (e.g., RNTI) can be used to scramble the DCI message.

[0183] According to a third exemplary variant, the BWP control signal can include several information blocks and be addressed to a group of UEs, each information block being addressed to one or several UEs. Correspondingly, the UEs are informed which information blocks are relevant to them, and then, upon receiving the BWP control signal, each UE can read the corresponding information block. According to an example, the BWP control signal can be a DCI message having a format identical or similar to the DCI format 2_6 described above in connection with the 3GPP implementation, for example.

[0184] As explained above, one variant of the first solution allows implementing a common BWP control signal for a UE group. The following description relates to details on how the base station determines the group of UEs to which the BWP control signal is addressed. It is also possible to reduce the system bandwidth and save energy on the network side by simply adapting the BWP operation of the UE group. As an example, when a group of UEs becomes less traffic, this group of UEs may use a narrower BWP. Therefore, one option to determine the group of UEs is to select UEs based on their traffic status.

[0185] <Second solution - spatial domain - SSB and RS adaptation> According to this second solution, network energy savings are promoted by adapting the spatial domain operation between the UE and the base station, specifically by adapting the SSB and / or Reference Signals (RS) used between the UE and the base station. This improved spatial domain adaptation procedure is under the control of the base station.

[0186] The improved adaptation procedure according to the second solution assumes that by providing an improved mechanism for dynamically adapting the spatial domain operation between the UE and the base station, the base station can further save energy (especially on the network side) while adapting the operation to the current traffic load and coverage. For example, the base station can adjust the following hardware parameters: Number of active antenna elements, Number of antenna panels, and ·TRP (Transmitting / Receiving Point) One or more of the following may be adjusted:

[0187] This allows the base station to save energy. Thus, the base station has the ability to adapt its hardware parameters to meet several requirements such as traffic load and required coverage. In one exemplary implementation of the improved spatial domain adaptation procedure, it is assumed that the base station adapts, specifically reduces, the number of active antenna elements. This may result in different shapes, patterns, or numbers of beams that the base station can transmit.

[0188] From the UE's point of view, the UE is not aware whether the base station has changed the number of active antenna elements or not, however, since a change in the number of antenna elements affects the transmission characteristics, the UE(s) should be effectively informed of the relevant changes in this regard.

[0189] Correspondingly, the UE can track the beam transmitted from the base station based on the SSB and a reference signal (e.g., CSI-RS or TRS). As a result, the second solution includes two variants, the first variant providing an improved SSB adaptation procedure, and the second variant providing an improved RS adaptation procedure. The first and second variants can be used individually or together.

[0190] In the following description, it is illustratively assumed that the base station intends to reduce the number of active antenna elements to facilitate energy savings at the base station, however, the following description applies equally to changes in the number of antenna panels and / or TRPs.

[0191] A first variant of the second solution concerns an improved SSB adaptation procedure: Each UE is configured to operate according to a set of SSBs, hereafter called cell-defining SSBs (CD-SSB), which in one exemplary option can be configured using SIB1 (System Information Block 1).

[0192] As mentioned above, the base station is responsible for changing the active antenna elements, which may result in the need to adapt the beam and thus the SSBs transmitted via the beam.

[0193] The resulting set of SSBs may differ in various ways from the set of SSBs previously used (CD-SSBs), including, for example: Changing the number of SSBs sent as part of a set of SSBs Changing the time or frequency at which some or all of the SSBs of a set of SSBs are transmitted · Changing the sequence used for PSS / SSS of SSB sets ·Beam (SSB) index change -Transmission power at which SSB is transmitted Power gap between SSB and CD-SSB The radio resources of the PRACH (Physical Random Access Channel) associated with the SSBs of the set of SSBs may include one or more of:

[0194] Another possible difference is the channel raster used by SSB. Specifically, the channel raster defines a subset of RF reference frequencies that can be used to identify RF channel locations in the uplink and downlink. In one exemplary 5G NR-compliant implementation, according to 3GPP TS38.104v17.3.0, including sections 5.4.2 and 5.4.3: - NR-ARFCN (New Radio - Absolute Radio Frequency Channel Number) - absolute radio-frequency channel number)) Table 5.4.2.1-1: NR-ARFCN parameters for global frequency raster Table 5.4.2.3-1: NR-ARFCN applicable to each FR1 operating band Table 5.4.2.3-2: NR-ARFCN applicable to each FR2 operating band - GSCN (Global Synchronization Raster Channel) ○ Table 5.4.3.1-1: GSCN parameters for global frequency raster ○ Table 5.4.3.3-1: Applicable SS raster entries per operating band (in FR1) Table 5.4.3.3-2: Applicable SS Raster Entries per Operating Band (in FR2) exists.

[0195] Therefore, the base station may use a different SSB than before and needs to inform the UE accordingly. For this purpose, the base station generates an SSB control signal indicating a target SSB pattern to be used by the UE (and also used by the base station) that includes one or more SSBs of the set of candidate SSBs. The generated SSB control signal is transmitted from the base station to the UE.

[0196] When the UE receives the SSB control signal indicating the target SSB pattern, the UE subsequently operates according to this target SSB pattern instead of according to the CD-SSB. Thus, the UE performs SSB-related functions, such as, for example, one or more of serving cell measurements, time synchronization, and frequency synchronization, based on the target SSB pattern. Accordingly, the base station and the UE operate using the same SSB, and the base station can save energy by using fewer antenna elements.

[0197] The base station is responsible for determining the SSBs of the target SSB pattern. The base station's determination of the target SSB pattern can depend on various criteria, including the number of active antenna elements, the current traffic situation of the UEs in its radio cell, the intended energy savings on the network side, or other criteria.

[0198] In one example, the number of beams is reduced from 8 beams to 4 beams and the number of SSBs transmitted by the base station is correspondingly reduced from 8 SSBs to 4 SSBs. This is shown in a simplified manner in Figure 18. The upper part of Figure 18 shows a CD-SSB containing 8 SSBs (see also Figure 8), correspondingly the 8 SSBs are transmitted in a beam sweeping manner using 8 beams, one SSB per beam.

[0199] The base station changes the active antenna elements from 64 to 8, and as a result uses only 4 beams instead of 8. Therefore, the base station also determines that it needs to transmit fewer SSBs, i.e. only 4 SSBs (still one SSB per beam). An example of a resulting beam pattern is shown in the lower half, where, of all candidate SSBs, the target SSB pattern consists of SSBs with indexes 0, 2, 4, and 6.

[0200] In the above, it was exemplarily assumed that the antenna elements are reduced, resulting in a change in the SSB, and as a result, the SSB is adapted to use the target SSB pattern. However, the improved SSB adaptation procedure may include further changes in the SSB, for example when the network energy saving function is reduced or stopped. Correspondingly, the base station in such a case may decide to use more antenna elements again, for example the same (or fewer or more) antenna elements as before the SSB switching.

[0201] According to one option, the SSB control signal according to the improved SSB adaptation procedure of the second solution can be used to reconfigure the SSB pattern of the UE(s). In one example, the base station may determine yet another target SSB pattern as explained above and provide the SSB control signal to the UE(s). In another example, the base station may decide to return to the original SSB pattern used before switching to the target SSB pattern. Thus, the SSB control signal may include an appropriate trigger for each UE to return to the original SSB, for example CD-SSB.

[0202] According to another option, the base station can use a legacy mechanism (defined in previous 5G NR standards) to instruct the UE to return to the original SSB (e.g., CD-SSB). Such a legacy mechanism can be for returning to CD-SSB.

[0203] As another example, the SSB adaptation procedure may also include the UE action of returning to the original SSB, e.g., CD-SSB, after the timer expires. The timer is triggered to start counting from the point in time when the UE is instructed to use the new set of SSBs. The timer value can be set by the gNB via RRC configuration, MAC CE, or DCI.

[0204] Above it was assumed that the operational target SSB pattern is indicated to the UE using an SSB control signal. The following exemplary variants relate to details on how the target SSB pattern can be indicated as part of the SSB control signal. In one exemplary variant, the target SSB pattern can be indicated by a suitable indicator included in the SSB control signal, and the SSB pattern indication can be in the form of a bitmap, where each bit is associated with one SSB of a set of candidate SSBs and indicates whether the respective candidate SSB is transmitted or not. The number of bits of such a target SSB indication can be the same as the number of candidate SSBs of the SSB set from which the base station can determine the target SSB pattern. Such a solution is similar to the concept currently implemented in the 5G NR compliant communication system described above, where the information element ssb-PositionsInBurst indicates the time domain positions of the SSBs to be transmitted as a bitmap.

[0205] According to another option, the target SSB indicator can be in the form of an index pointing to an entry of different preconfigured candidate SSB patterns. These candidate SSB patterns can be preconfigured by the base station using appropriate SSB configuration signaling. Correspondingly, different candidate SSB patterns can be defined together with corresponding SSB pattern IDs. The base station determines one among the different candidate SSB patterns and generates an SSB control signal to include the SSB pattern ID corresponding to the determined target SSB pattern. In turn, the UE can determine the corresponding target SSB pattern among the different preconfigured SSB patterns from the received SSB pattern ID.

[0206] The following variants relate to how the SSB control signal itself can be implemented. In general, the SSB control signal can be implemented the same or similar to the BWP control signal, for example, the signal can be a Downlink Control Information DCI message. According to one option, a new DCI message can be defined, including an appropriate field for carrying the target SSB pattern indication, which is not yet defined in the 3GPP 5G standard.

[0207] Another option is to reuse existing DCI messages to carry SSB control signals. For example, the existing DCI messages are DCI messages for paging, DCI messages for signaling one or more of slot format and search space set group switching, e.g., DCI messages having a format identical or similar to DCI format 2_0 described above for a 3GPP 5G compliant communication system; DCI messages for reporting power saving information, for example DCI messages having a format identical or similar to DCI format 2_6 described above for a 3GPP 5G compliant communication system; DCI messages for indicating one or more of whether to start monitoring for a paging early control signal and whether a reference signal is available, for example DCI messages having a format identical or similar to DCI format 2_7 described above for a 3GPP 5G compliant communication system; It can be said that:

[0208] When reusing such existing DCI messages, a new field may be added or an existing field may be reused to carry the target SSB pattern indication.

[0209] Alternatively, the SSB control signal may be a message of the Radio Resource Control (RRC) protocol.

[0210] According to yet another alternative, the SSB control signal may be implemented as a control element of a medium access control MAC protocol.

[0211] Furthermore, as explained above, the SSB control signals transmitted by the base station may be common to a cell or to a group of UEs.

[0212] According to a first exemplary variant, the SSB control signal may be addressed to an identifier common to the entire radio cell, and all UEs located within that radio cell will determine that the SSB control signal is intended for them and proceed to process the SSB control signal. In one example, it may be assumed that the SSB control signal is a DCI message, in which case a cell-common identifier (e.g., RNTI) may be used to scramble the DCI message.

[0213] According to a second exemplary variant, the SSB control signal can be addressed to an identifier common to a group of UEs. Since each UE in the group knows the group identifier, the UE determines that the SSB control signal is intended for it and proceeds to process the SSB control signal. In one example, it can be assumed that the SSB control signal is a DCI message, in which case a UE group common identifier (e.g., RNTI) can be used to scramble the DCI message.

[0214] According to a third exemplary variant, the SSB control signal can include several information blocks and be addressed to a group of UEs, each information block being addressed to one or several UEs. Correspondingly, the UEs are informed which information blocks are relevant to them, and then, upon receiving the SSB control signal, each UE can read the corresponding information block. According to an example, the SSB control signal can be a DCI message, for example having the same or similar format as DCI format 2_6 described above in connection with the 3GPP implementation.

[0215] As explained above, one variation of the SSB adaptation procedure allows for implementing SSB signals common to a group of UEs. The following description provides details on how the base station determines the group of UEs to which the SSB control signal is addressed.

[0216] For example, for some UEs served by a particular TRP, antenna panel, or group of antenna elements that the gNB decides to later change, activate, or deactivate through traffic adaptation for energy savings, these UEs are selected by the gNB to direct SSB adaptation through a UE group common SSB signal since they are affected as a result of the gNB's actions.

[0217] A second variant of the second solution relates to an improved reference signal adaptation procedure. Each UE is configured to operate based on a specific reference signal, in this example one or more of CSI-RS and TRS. A set of CSI-RS and a set of TRS are configured for each UE, and the UE can use these reference signals to perform reference signal-related functions, such as channel state measurement, interference measurement, beam management, time tracking, frequency tracking, etc.

[0218] As already explained above in the first SSB variant of the second solution, the base station is responsible for changing the active antenna elements, which may result in the need to adapt the beams and also the reference signals (e.g. CSI-RS and TRS) transmitted via the beams. The resulting reference signals may differ in various ways from the previously used reference signals, for example in terms of the following parameters: - time radio resources, - frequency radio resources, - a sequence of reference signals, - Scramble ID, - Quasi Co Location (QCL) criterion, - Transmission power gap compared to the reference synchronization signal block One or more of may be different.

[0219] The Scrambling ID described above can be used, for example, to scramble the RS sequence values ​​to generate the complex-valued sequence that is actually transmitted, randomizing the transmitted signal and reducing interference to adjacent cells.

[0220] Therefore, the base station may use a different reference signal than before and needs to inform the UE accordingly. For this purpose, the base station generates an RS control signal that indicates the target setting of the reference signal to be used by the UE (and also by the base station). The generated RS control signal is transmitted from the base station to the UE.

[0221] When the UE receives the RS control signal indicating the target RS configuration, the UE subsequently operates according to the indicated target RS configuration instead of continuing to use the previous reference signal configuration. Correspondingly, the UE performs reference signal-related functions, such as, for example, one or more of channel state measurement, interference measurement, beam management, time tracking, and frequency tracking, based on the indicated target RS configuration. Accordingly, the base station and the UE operate using the same RS configuration determined by the base station, and save energy as a result of using fewer antenna elements.

[0222] The base station is responsible for determining the target RS configuration, which may depend on various criteria, including, for example, the number of active antenna elements, the current traffic situation of the UE in its radio cell, the intended energy savings on the network side, or other criteria, as already explained above with respect to the target SSB pattern.

[0223] In the above, it is exemplarily assumed that the antenna elements are reduced, and as a result, the RS configuration is changed. However, the improved RS adaptation procedure may include further modification of the reference signal, such as when the network energy saving function is reduced or stopped. Correspondingly, the base station in such a case may decide to use more antenna elements again, for example, the same (or fewer or more) antenna elements as before the RS switching.

[0224] According to one option, the RS control signal according to the improved RS adaptation procedure of the second solution can be used to reconfigure the reference signal of the UE(s). In one example, the base station may determine further target RS configurations as described above and provide RS control signal to the UE(s). In another example, the base station may decide to return to the original RS configuration used before switching to the target RS configuration. Thus, the RS control signal may include an appropriate trigger for each UE to return to its original RS configuration.

[0225] According to another option, the base station can use a legacy mechanism (defined in previous 5G NR standards) to instruct the UE to revert to the original RS configuration. Such a legacy mechanism can be based on an RRC message, such that the UE follows the RRC RS configuration. According to yet another example, the RS adaptation procedure can also include a UE behavior of reverting to the original RS configuration after a timer expires. The timer is triggered to start counting from the point in time when the UE is instructed to use the target RS configuration. The value of the timer can be set by the gNB via RRC configuration, MAC CE, or DCI.

[0226] In the above, it is assumed that the operational target RS configuration is indicated to the UE using an RS control signal. The following exemplary variants relate to details on how the target RS configuration can be indicated as part of the RS control signal. In one exemplary variant, the target RS configuration indicator can be in the form of an index pointing to an entry of different previously configured candidate RS configurations. These candidate RS configurations can be pre-configured by the base station using appropriate RS configuration signaling. Correspondingly, various candidate RS configurations can be defined with corresponding RS configuration IDs. The base station determines one among the different candidate RS configurations and generates an RS control signal to include the RS configuration ID corresponding to the determined target RS configuration. In turn, the UE can determine the corresponding RS configuration among the various pre-configured RS configurations from the received RS configuration ID.

[0227] The following variants relate to how the RS control signal itself can be implemented. In general, the RS control signal can be implemented the same or similar to the SSB control signal, for example, the signal can be a downlink control information DCI message. According to one option, a new DCI message can be defined that includes an appropriate field for carrying the target RS configuration indication, which is not yet defined in the 3GPP 5G standard.

[0228] Another option is to reuse existing DCI messages to carry RS control signals. For example, the existing DCI messages are DCI messages for paging, DCI messages for signaling one or more of slot format and search space set group switching, e.g., DCI messages having a format identical or similar to DCI format 2_0 described above for a 3GPP 5G compliant communication system; DCI messages for reporting power saving information, for example DCI messages having a format identical or similar to DCI format 2_6 described above for a 3GPP 5G compliant communication system; DCI messages for indicating one or more of whether to start monitoring for paging control signals and whether reference signals are available, for example DCI messages having a format identical or similar to DCI format 2_7 described above for a 3GPP 5G compliant communication system; It can be said that:

[0229] When reusing such an existing DCI message, a new field may be added or an existing field may be reused to carry the target RS configuration indication.

[0230] Alternatively, the RS control signal may be a message of a radio resource control RRC protocol.

[0231] According to yet another alternative, the RS control signal may be implemented as a control element of a medium access control MAC protocol.

[0232] Furthermore, as explained above, the RS control signals transmitted by the base station may be common to a cell or to a group of UEs.

[0233] According to a first exemplary variant, the RS control signal may be addressed to an identifier common to the entire radio cell, and all UEs located within that radio cell may determine that the RS control signal is intended for them and proceed to process the RS control signal. In one example, it may be assumed that the RS control signal is a DCI message, in which case a cell-common identifier (e.g., RNTI) may be used to scramble the DCI message.

[0234] According to a second exemplary variant, the RS control signal may be addressed to an identifier common to a group of UEs. Since each UE in the group knows the group identifier, the UE determines that the RS control signal is directed to it and proceeds to process the RS control signal. In one example, it may be assumed that the RS control signal is a DCI message, in which case a UE group common identifier (e.g., RNTI) may be used to scramble the DCI message.

[0235] According to a third exemplary variant, the RS control signal may include several information blocks addressed to a group of UEs, each information block being addressed to one or more UEs. Correspondingly, the UEs are informed which information blocks are relevant to them, and then, upon receiving the RS control signal, each UE may read the corresponding information block. According to an example, the RS control signal may be a DCI message having a format identical or similar to, for example, DCI format 2_6 as described above in connection with the 3GPP implementation.

[0236] As explained above, one variation of the RS adaptation procedure allows for implementing RS signals common to a group of UEs. The following description relates to the details of how the base station determines the group of UEs to which the RS control signal is destined.

[0237] For example, for some UEs served by a particular TRP, antenna panel, or group of antenna elements that the gNB decides to later change, activate, or deactivate by traffic adaptation for energy savings, these UEs are selected by the gNB to direct RS adaptation by the UE group common SSB signal since they are affected as a result of the gNB's actions.

[0238] <Third solution - Time domain adaptation> According to this third solution, network energy savings are promoted by adapting the time domain operations between the UE and the base station, specifically by defining blanking periods during which the UE is allowed to skip some communication operations. This improved time domain adaptation procedure is under the control of the base station, which is responsible for determining the blanking periods during which the UE and the base station are allowed to skip certain communications between each other, e.g. one or more of the downlink and uplink communications.

[0239] Thus, from the base station's perspective, the base station is permitted to not receive uplink communications from, and not transmit downlink communications to, the UE(s) in the cell, and from the UE's perspective, the UE is permitted to not receive downlink communications from, and not transmit uplink communications to, the base station.

[0240] The base station may take into account certain requirements (e.g., current traffic) when determining the blank period and when determining whether energy savings are achieved by skipping downlink communication (hereinafter referred to as DL blank period), or by skipping uplink communication (hereinafter referred to as UL blank period), or by skipping both uplink and downlink communication (hereinafter referred to as UL+DL blank period).

[0241] Other alternatives to the term "blank" could be skip, sleep, low activity, or light.

[0242] In addition to the energy saving advantages promoted by the third solution on the UE and base station side, avoiding uplink transmissions from the UE may make it possible to reduce interference caused by the UE, and conversely avoiding downlink transmissions from the base station may make it possible to reduce interference caused by the base station.

[0243] As a result of those blanking periods, the base stations and UEs can conserve energy by turning off hardware circuitry or relaxing processing timelines. For example, the base stations and UEs can deactivate some or all of their radio frequency (RF) and / or baseband modules to conserve network energy during those blanking periods.

[0244] The base station is responsible for determining the blanking period and deciding whether the blanking period relates to the downlink, the uplink, or both the uplink and the downlink. This decision by the base station can be based on certain criteria, such as the current traffic with the UE in its radio cell, the intended energy savings on the network side, or other criteria.

[0245] After determining the appropriate blanking periods, the base station can generate and transmit to the UE an appropriate blanking period control signal indicating the determined blanking periods. Upon receiving the blanking period control signal, the UE determines the indicated blanking periods and then operates according to these determined blanking periods. For example, both the UE and the base station operate accordingly during the indicated blanking periods, e.g., the UE does not transmit on the uplink while the base station does not expect to receive from the UE on the uplink, or the base station does not transmit on the downlink while the UE does not expect to receive from the base station on the downlink.

[0246] The period can be of different types, for example, it can span one or more time slots of a subframe, or span one or more OFDM symbols of a time slot, or span one or more subframes of a frame, or span one or more frames, or it can be defined as a certain duration (e.g., in milliseconds). The period can be a one-time period in the sense that it is applied only once in response to receiving a blanking period control signal. In that case, the blanking period control signal can simply indicate the duration, such as a value in milliseconds. This one-time period can start at a specific (predefined) time point after receiving the control signal and end correspondingly after the period has ended.

[0247] Alternatively, the period may be periodic in the sense that it is repeatedly applied at a regular period in response to receipt of a blanking period control signal, in which case the blanking period control signal may indicate a duration (e.g., a value in milliseconds) and a period.

[0248] According to yet another option, the blank period follows a blank period pattern indicated by the blank period control signal. Specifically, a plurality of different blank period patterns can be predefined by the base station using appropriate configuration signaling. For example, the blank period pattern can define a series of spaced apart periods, each period being either a DL, UL, or DL+UL blank period. Correspondingly, different blank period patterns can be defined and associated with a blank period pattern ID, respectively. The base station can generate a blank period control signal including the blank period pattern ID of the determined blank period pattern. In turn, the UE can determine the ID from the received blank period control signal, and thus determine the blank period pattern among the plurality of blank period patterns.

[0249] A further exemplary option relates to the use of a slot format indicator as part of the blanking period control signal. The slot format indicator indicates a particular slot format, which is then interpreted by the UE and base station in an appropriate manner to indicate the blanking period. Specifically, the slot format defines how each OFDM symbol of the slot is used.

[0250] According to a first exemplary implementation, the slot format distinguishes each OFDM symbol as either downlink, uplink, or flexible, where flexible can mean either uplink or downlink. In this case, the flexible OFDM symbol can be reinterpreted as a blanking period. Correspondingly, when such a slot format is applied between a UE and a base station, each "flexible" OFDM symbol of a slot is used as a blanking period to save energy. Alternatively, not all "flexible" OFDM symbols of a slot are used as blanking periods, but only a part of them, for example the first two flexible OFDM symbols, are used as blanking periods.

[0251] According to another second exemplary implementation, the slot format distinguishes each OFDM symbol as either downlink, uplink, flexible or blank. Correspondingly, a new type of OFDM symbol is introduced by this implementation, and this new blank type OFDM symbol can be interpreted as meaning that no uplink or downlink communication is expected to occur during these blank OFDM symbols.

[0252] In either of the two implementations, different slot formats are predefined and associated with appropriate slot format IDs. The base station can determine the slot format and include the associated slot format ID in the blanking period control signal. In turn, the UE can determine the slot format, and thus the blanking period, from the received slot format ID.

[0253] In the 5G NR compliant communication system described above, the slot format is indicated using DCI format 2_0. In one variation, a similar or identical DCI format 2_0 can be used as the blanking period control signal.

[0254] Above we illustratively assumed that time domain operations are limited to promote network energy conservation. Some of the above implementations have limitations on how long they apply, such as a one-time blanking period.

[0255] However, in other implementations it may be advantageous to allow the mechanism to return to normal operation, for example when network energy saving features are reduced or stopped. To this end, in one option, an appropriate stop signal may be sent by the base station to the UE.

[0256] Alternatively, the blanking period control signal may already include appropriate information, such as the maximum time for which the blanking period is to be applied.

[0257] According to yet another alternative, the base station may, for example, transmit an other slot format indicator to instruct the UE to override the current slot format and operate according to another slot format having fewer or no blanking periods.

[0258] The following exemplary variants relate to how the blanking period control signal itself can be implemented. In general, the blanking period control signal can be a downlink control information DCI message. According to one option, a new DCI message can be defined that includes an appropriate field for carrying the blanking period indication, which is not yet defined in the 3GPP 5G standard.

[0259] Another option is to reuse an existing DCI message to carry the blanking period indication. For example, the existing DCI message may be DCI messages for paging, DCI messages for signaling one or more of slot format and search space set group switching, e.g., DCI messages having a format identical or similar to DCI format 2_0 described above for a 3GPP 5G compliant communication system; DCI messages for reporting power saving information, for example DCI messages having a format identical or similar to DCI format 2_6 described above for a 3GPP 5G compliant communication system; DCI messages for indicating one or more of whether to start monitoring for a paging early control signal and whether a reference signal is available, for example DCI messages having a format identical or similar to DCI format 2_7 described above for a 3GPP 5G compliant communication system; It can be said that:

[0260] When reusing such existing DCI messages, a new field may be added or an existing field may be reused to carry the blanking period indication.

[0261] Alternatively, the blanking period control signal may be a message of a radio resource control RRC protocol.

[0262] According to yet another alternative, the blanking period control signal may be implemented as a control element of a medium access control MAC protocol.

[0263] Furthermore, as explained above, the blanking period control signal transmitted by the base station may be common to a cell or to a group of UEs.

[0264] According to a first exemplary variant, the blanking period control signal may be addressed to an identifier common to the entire radio cell, and all UEs located within that radio cell may determine that the blanking period control signal is intended for them and proceed to process the blanking period control signal. In one example, it may be assumed that the blanking period control signal is a DCI message, in which case a cell-common identifier (e.g., RNTI) may be used for scrambling the DCI message.

[0265] According to a second exemplary variant, the blanking period control signal can be addressed to an identifier common to a group of UEs. Since each UE in the group knows the group identifier, the UE determines that the blanking period control signal is intended for it and proceeds to process the blanking period control signal. In one example, it can be assumed that the blanking period control signal is a DCI message, in which case a UE group common identifier (e.g., RNTI) can be used to scramble the DCI message.

[0266] According to a third exemplary variant, the blanking period control signal may include several information blocks and be addressed to a group of UEs, each information block being addressed to one or several UEs. Correspondingly, the UEs are informed which information blocks are relevant to them, and then, upon receiving the blanking period control signal, each UE may read the corresponding information block. According to an example, the blanking period control signal may be a DCI message having a format identical or similar to, for example, DCI format 2_6 as described above in connection with the 3GPP implementation.

[0267] As explained above, one variation of the time domain solution allows for implementing a UE group common blanking period control signal. The following description relates to the details of how the base station determines the group of UEs to which the blanking period control signal is addressed.

[0268] As an example, with respect to traffic adaptation, the gNB may estimate that some UEs' DL or UL traffic will not come, or will not be scheduled even if traffic comes, and then the gNB may instruct this group of UEs by control signals to perform the above-mentioned time domain adaptation.

[0269] Another example is that the gNB may decide to turn off or deactivate some of the TRPs, antenna panels, antenna elements for DL ​​transmission, UL reception, or both. The gNB may then instruct by control signals the groups of UEs served by these TRPs, antenna panels, or elements to perform the adaptation described above.

[0270] <Fourth solution - Downlink control channel adaptation> According to this fourth solution, network energy savings are promoted by adapting downlink control channel related operations between the UE and the base station. This improved downlink control channel adaptation procedure is under the control of the base station, which is responsible for determining how downlink control channel (e.g., PDCCH) operations between the UE and the base station are performed.

[0271] In the fourth solution, two separate mechanisms are provided, the first being the possibility to skip downlink control channel operation for a certain period in the base station and the UE, and the second being the possibility to switch search space set groups associated with monitoring the downlink control channel.

[0272] The downlink control channel adaptation procedure involves the base station transmitting a corresponding control signal, hereafter referred to as the PDCCH adaptation control signal, which can be common to all UEs in its radio cell or to a group of UEs. The PDCCH adaptation control signal instructs the UE to implement one or both of the two mechanisms.

[0273] According to the first mechanism of this fourth solution (hereinafter referred to as PDCCH skip mechanism), the base station does not need to transmit control data on the downlink control channel to any UE or group of UEs in its radio cell for a certain period of time, so energy can be saved. In turn, the UE does not need to monitor the downlink control channel during that period of time, so energy can be saved as well.

[0274] Correspondingly, the PDCCH adaptation control signal may include appropriate instructions regarding whether and for how long the UE and base station may skip the PDCCH, for example when the gNB decides to enter a sleep mode for a particular period of time.

[0275] The base station may determine whether to apply the PDCCH skip mechanism and may also determine the period.

[0276] According to the second mechanism of this fourth solution (hereinafter referred to as SSS group switching mechanism), the group of the search space set currently used by the UE to monitor the PDCCH is changed to another target SSS group. This target SSS group can be defined to enable network energy saving at the base station side, for example, by defining a long (longer) period during which the UE does not need to monitor the PDCCH during a slot. For this purpose, a set of corresponding SSS groups suitable for facilitating network energy saving is predefined by the base station and signaled to the UE. Each SSS group in the set can be associated with an SSS group ID. The PDCCH adaptation control signal can then include an appropriate indication with the SSS group ID regarding which SSS group the UE should use.

[0277] The base station determines the target SSS group to be used and generates a corresponding SSS group indication for the PDCCH adaptation control signal.

[0278] The following exemplary variants relate to how the PDCCH adaptation control signal itself can be implemented. In general, the PDCCH adaptation control signal can be a downlink control information DCI message. According to one option, a new DCI message can be defined that includes appropriate fields for carrying the PDCCH skip indication and the SSS group indication, which are not yet defined in the 3GPP 5G standard.

[0279] Another option is to reuse existing DCI messages to carry the PDCCH adaptation control signals. For example, the existing DCI messages are DCI messages for paging, DCI messages for signaling one or more of slot format and search space set group switching, e.g., DCI messages having a format identical or similar to DCI format 2_0 described above for a 3GPP 5G compliant communication system; DCI messages for reporting power saving information, for example DCI messages having a format identical or similar to DCI format 2_6 described above for a 3GPP 5G compliant communication system; DCI messages for indicating one or more of whether to start monitoring for a paging early control signal and whether a reference signal is available, for example DCI messages having a format identical or similar to DCI format 2_7 described above for a 3GPP 5G compliant communication system; It can be said that:

[0280] When reusing such existing DCI messages, new fields may be added or existing fields may be reused to carry the PDCCH skip indication and the target SSS group indication.

[0281] Alternatively, the PDCCH adaptation control signal may be a message of the radio resource control RRC protocol.

[0282] According to yet another alternative, the PDCCH adaptation control signal may be implemented as a control element of a medium access control MAC protocol.

[0283] Furthermore, as explained above, the PDCCH adaptive control signals transmitted by the base station may be common to a cell or to a group of UEs.

[0284] According to a first exemplary variant, the PDCCH adaptation control signal may be addressed to an identifier common to the entire radio cell, and all UEs located within that radio cell may determine that the PDCCH adaptation control signal is intended for them and proceed to process the PDCCH adaptation control signal. In one example, it may be assumed that the PDCCH adaptation control signal is a DCI message, in which case a cell-common identifier (e.g., RNTI) may be used for scrambling the DCI message.

[0285] According to a second exemplary variant, the PDCCH adaptive control signal may be addressed to an identifier common to a group of UEs. Since each UE in the group knows the group identifier, the UE determines that the PDCCH adaptive control signal is intended for it and proceeds to process the PDCCH adaptive control signal. In one example, it may be assumed that the PDCCH adaptive control signal is a DCI message, in which case a UE group common identifier (e.g., RNTI) may be used to scramble the DCI message.

[0286] According to a third exemplary variant, the PDCCH adaptation control signal may include several information blocks addressed to a group of UEs, each information block being addressed to one or several UEs. Correspondingly, the UEs are informed which information blocks are relevant to them and then, upon receiving the PDCCH adaptation control signal, each UE may read the corresponding information block. According to an example, the PDCCH adaptation control signal may be a DCI message having a format identical or similar to, for example, DCI format 2_6 as described above in connection with the 3GPP implementation.

[0287] Other mechanisms exist in the current 5G NR standard that allow for indicating PDCCH skipping and SSS group switching, but the corresponding signaling is UE specific rather than cell / UE group common as described above with respect to the PDCCH adaptation control signal of the fourth solution. In one variant of the fourth solution, the priority of the UE specific mechanisms for PDCCH skipping and SSS group switching has a higher priority than the corresponding cell / UE group common PDCCH adaptation of the fourth solution.

[0288] Alternatively, the UE does not expect inconsistent behavior when instructed by both a UE-specific mechanism (for PDCCH skipping or SSS group switching) and a cell / UE group common mechanism. If such inconsistent behavior occurs, the UE may detect this error case and, for example, operate according to only one instruction, e.g., the UE-specific instruction or the cell / UE group common instruction.

[0289] <Fifth solution - a combination of the above solutions> Above, four solutions (and their variants) have been described individually and independently of each other. According to this fifth solution, two, more than two or all of the four solutions are implemented in combination to obtain a synergistic effect.

[0290] Specifically, the four solutions provide five different control signals: a BWP control signal, an SSB control signal, an RS control signal, a blanking period control signal, and a PDCCH adaptation control signal.

[0291] These control signals are transmitted to adapt the corresponding operations between the UE and the base station. It is also possible to combine two or more as well as all control signals into one and the same message.

[0292] As an example, the BWP control signal can be combined with one or more of the remaining SSB control signals, the RS control signals, the blanking period control signals, and the PDCCH adaptation control signals. As another example, the SSB control signal can be combined with one or more of the remaining BWP control signals, the RS control signals, the blanking period control signals, and the PDCCH adaptation control signals. And so on.

[0293] As a result, the combined message includes some of the following indications: target BWP indication, SSB pattern indication, RS configuration indication, blanking period indication, PDCCH skip indication, and SSS group indication. Correspondingly, applying two or more network energy saving mechanisms can improve network energy saving while allowing efficient indications that cause only limited overhead by using one combined message.

[0294] In one exemplary implementation of the fifth solution, assuming that five control signals of cell-common type are used, two or more of these five cell-common control signals can be combined, given that they are addressed in the same way.

[0295] On the other hand, if a common control signal is used for a UE group, the combined control signal message is addressed to the same UE group. Correspondingly, the base station can determine which of the five control signals can be combined into one message depending on the targeted UE group. The advantage of the combination is that it can save control overhead. Also, reusing parts of existing signaling / procedure frameworks such as the BWP framework has less impact on standard specifications and reduces the complexity of implementation / development of base stations and UEs.

[0296] In one example implementation, the BWP control signal also implicitly indicates the SSB set and / or time domain adaptation that are part of the configuration in the RRC configuration of the BWP. When the UE switches to the target BWP, it may also apply the corresponding SSB or time domain adaptation according to the configuration associated with the target BWP.

[0297] Further aspects According to a first aspect, a user equipment is provided, which includes: a receiver of the UE receives a first control signal from a base station, the first control signal being common to a radio cell to which the UE belongs or a group of UEs, the first control signal indicating an operating target bandwidth part BWP; a processing circuit of the UE operates according to the indicated target BWP.

[0298] According to a second aspect provided in addition to the first aspect, the processing circuit determines a currently active BWP, and switches from the determined currently active BWP to the indicated target BWP if the determined currently active BWP is different from the indicated target BWP. In an optional implementation, the processing circuit performs BWP-related functions based on the target BWP. Further, optionally, the BWP-related functions include one or more of a random access procedure, a measurement, and monitoring a downlink control channel.

[0299] According to a third aspect provided in addition to the first or second aspect, the target BWP comprises: - Default BWP configured in the UE, Initial BWP configured in the UE, Dormant BWP configured in the UE, The first non-dormant BWP configured in the UE; A common BWP configured in the UE, the common BWP being common to all UEs in a radio cell of the base station or common to a group of UEs; It is one of them. The target BWP may be narrower, wider, or have the same frequency bandwidth as the currently active BWP.

[0300] According to a third aspect provided in addition to any one of the first to fourth aspects, a first control signal instructing an operation target BWP is: A downlink control information (DCI) message, optionally DCI messages for paging, A DCI message for notifying one or more of a slot format and a search space set group switch, for example a DCI message having a format of DCI format 2_0 of a 3GPP communication system; A DCI message for notifying power saving information, for example, a DCI message having a format of DCI format 2_6 of the 3GPP communication system; A DCI message for informing one or more of whether to start monitoring for a paging early control signal and whether a reference signal is available, for example a DCI message having a format of DCI format 2_7 of a 3GPP communication system; a downlink control information DCI message including one of: Radio Resource Control (RRC) protocol messages; A control element of the Medium Access Control (MAC) protocol; It is one of them.

[0301] According to a fifth aspect provided in addition to any one of the first to fourth aspects, the first control signal indicates the operating target BWP based on a target BWP indicator having one or more bits and identifying a target BWP among the set of BWPs. In an optional implementation, the receiver receives a BWP setting signal for setting the set of BWPs.

[0302] According to a sixth aspect provided in addition to any one of the first to fifth aspects, a first control signal common to a group of UEs includes a plurality of information blocks, and the UE is associated with at least one of the plurality of information blocks. The processing circuit determines an information block associated with the UE. In an optional implementation, the first control signal is a downlink control information message having a format of DCI format 2_6 of the 3GPP communication system. Alternatively, the first control signal common to the group of UEs is addressed to an identifier associated with the group of UEs. The first control signal common to the radio cells is addressed to an identifier common to the entire radio cell.

[0303] According to a seventh aspect provided in addition to any one of the first to sixth aspects, the receiver receives a second control signal from the base station, the second control signal being common to a radio cell to which the UE belongs or a group of UEs. The second control signal indicates a target SSB pattern including one or more SSBs of a set of candidate synchronization signal blocks SSBs to be used by the UE. The processing circuit performs SSB-related functions based on the target SSB pattern indicated by the second control signal. In an optional implementation, the SSB-related functions include one or more of serving cell measurements, time synchronization, and frequency synchronization.

[0304] According to an eighth aspect provided in addition to the seventh aspect, the second control signal includes an SSB pattern indication for indicating a target SSB pattern. The SSB pattern indication is in the form of a bitmap, with each bit being associated with one candidate SSB of a set of candidate SSBs and indicating whether the respective candidate SSB is to be transmitted or not. In an optional implementation, each of the one or more candidate SSBs used by the UE is determined based on the following parameters: - the time domain period and offset of the candidate SSB; - the sequence used for the synchronization signal of the candidate SSB, - beam index of the candidate SSB, - the transmit power of the candidate SSB, - the transmission power gap of the candidate SSB compared to the cell-defining SSB, and - the radio resources of the physical random access channels associated with the candidate SSBs; - Channel raster of candidate SSBs, is defined by one or more of:

[0305] According to a ninth aspect provided in addition to any one of the first to eighth aspects, the receiver receives a third control signal from a base station, the third control signal being common to a radio cell to which the UE belongs or a group of UEs. The third control signal indicates a target configuration of one or more reference signals to be used by the UE from a set of reference signal configurations. The reference signals are one or more of a channel state information CSI reference signal and a tracking reference signal TRS. In an optional implementation, the processing circuit performs a reference signal related function based on the indicated target reference signal configuration. In an optional implementation, the reference signal related function includes one or more of a channel state measurement, an interference measurement, a beam management, a time tracking, and a frequency tracking.

[0306] According to a tenth aspect provided in addition to the eighth aspect, the third control signal includes a target reference signal configuration indication. The target reference signal configuration indication is in the form of an index pointing to one reference signal configuration of a plurality of reference signal configurations. In an optional implementation, each set of reference signal configurations may include the following parameters: - time radio resources, - frequency radio resources, - a sequence of reference signals, - Scramble ID, - Quasi-colocation QCL criteria, - a transmission power gap compared to the reference synchronization signal block, is defined by one or more of:

[0307] According to an eleventh aspect provided in addition to any one of the first to tenth aspects, the receiver receives a fourth control signal from the base station, the fourth control signal being common to a radio cell to which the UE belongs or a group of UEs. The fourth control signal indicates one or more (blank) periods during which the UE is allowed to skip one or more of receiving downlink communications from the base station and transmitting uplink communications to the base station. In an optional implementation, the one or more (blank) periods are defined per time slot of a subframe, or per OFDM symbol of a time slot, or per subframe of a frame, or per frame, or per unit of some duration.

[0308] According to a twelfth aspect provided in addition to the eleventh aspect, the fourth control signal indicates a (blank) period and indicates a duration of the (blank) period. The (blank) period starts at a time after receiving the fourth control signal and stops after the duration of the (blank) period ends. In an optional implementation, the (blank) period is applied periodically with a certain time period. Alternatively, the fourth control signal indicates a pattern of a (blank) period among a plurality of (blank) period patterns. In an optional implementation thereof, the receiver receives a (blank) period pattern setting signal for setting a plurality of (blank) period patterns.

[0309] According to a thirteenth aspect provided in addition to the eleventh aspect, the fourth control signal includes a slot format indicator SFI. The processing circuit determines the indicated one or more (blank) periods based on the value of the included SFI and on the association between different slot format definitions and different SFI values. The slot format defines how each OFDM symbol of the slot is used. In its optional implementation, the slot format defines each OFDM symbol in the slot as a downlink, an uplink or a flexible OFDM symbol, and the processing circuitry in operation determines that some or each flexible OFDM symbol is one of the (blank) periods; or The slot format defines each OFDM symbol in the slot as a downlink OFDM symbol, an uplink OFDM symbol, a flexible OFDM symbol or a (blank) OFDM symbol during which the UE is permitted to skip one or more of receiving downlink communications from the base station and transmitting uplink communications to the base station, and in operation the processing circuitry determines that each (blank) OFDM symbol during which the UE is permitted to skip one or more of receiving downlink communications from the base station and transmitting uplink communications to the base station is one of the (blank) periods.

[0310] According to a 14th aspect provided in addition to any one of the first to 13th aspects, the receiver, in operation, receives a fifth control signal from a base station, the fifth control signal being common to a radio cell to which the UE belongs or a group of the UEs, the fifth control signal comprising: - skipping monitoring of a downlink control channel for a period of time; - switching to a target search space set group indicated by a fifth control signal; and and instructing the UE to perform one or both of: Optionally, the fifth control signal is specific to the UE and has a lower priority than other control signals to instruct the UE to perform one of: skipping monitoring the downlink control channel; and switching to a target search space set group.

[0311] According to a 15th aspect provided in addition to the first, seventh, ninth, eleventh and fourteenth aspects, any combination of two or more of the first to fifth control signals is transmitted by the base station to the UE in the same message.

[0312] According to a 16th aspect provided in addition to the 1st, 7th, 9th, 11th and 14th aspects, any one or more of the 1st to 5th control signals is an upper layer signal of one of a medium access control (MAC control) element, a radio resource control (RRC) message addressed to one or more UEs, and a system information broadcast message.

[0313] According to a seventeenth aspect, a method for transmitting a signal to a user equipment (UE), the method comprising: receiving a first control signal from a base station, the first control signal being common to a radio cell to which the UE belongs or to a group of UEs, the first control signal indicating an operating target bandwidth part BWP; operating according to the indicated target BWP; A method is provided, comprising:

[0314] According to an eighteenth aspect, there is provided a base station comprising: a processing circuit of the base station determines an operating target bandwidth part BWP; a transmitter of the base station transmits a first control signal to all UEs or a group of UEs in a radio cell; the first control signal is common to the radio cell or the group of UEs and indicates the target BWP; and the processing circuit operates according to the indicated target BWP.

[0315] According to a nineteenth aspect provided in addition to the eighteenth aspect, the processing circuitry includes: - Default BWP configured in the UE, Initial BWP configured in the UE, Dormant BWP configured in the UE, The first non-dormant BWP configured in the UE; A common BWP configured in the UE, the common BWP being common to all UEs in a radio cell of the base station or common to a group of UEs; Determine one of the following:

[0316] According to a twentieth aspect provided in addition to the eighteenth or nineteenth aspects, the first control signal indicates the operation target BWP based on a target BWP indicator having one or more bits and identifying a target BWP among a set of BWPs. In an optional implementation, the transmitter transmits a BWP setting signal for setting the set of BWPs.

[0317] According to a 21st aspect provided in addition to any one of the 18th to 20th aspects, the processing circuit determines a target synchronization signal block SSB pattern. The transmitter transmits a second control signal to all UEs or a group of UEs in a radio cell. The second control signal indicates a target SSB pattern that is common to the radio cell or the group of UEs and includes one or more SSBs of a set of candidate SSBs used by the UE and the base station. The processing circuit performs an SSB-related function based on the target SSB pattern indicated by the second control signal.

[0318] According to a twenty-second aspect provided in addition to the twenty-first aspect, the second control signal includes an SSB pattern indication for indicating the target SSB pattern, the SSB pattern indication being in the form of a bitmap, with each bit being associated with one candidate SSB of a set of candidate SSBs and indicating whether or not each candidate SSB is to be transmitted.

[0319] According to a 23rd aspect provided in addition to any one of the 18th to 22nd aspects, a processing circuit determines a target configuration of one or more reference signals used by the UE and the base station. The transmitter transmits a third control signal to all UEs or a group of UEs in a radio cell. The third control signal is common to the radio cell and the group of UEs and indicates a target configuration of one or more reference signals of a set of reference signal configurations. The reference signals are one or more of a channel state information CSI reference signal and a tracking reference signal TRS. In an optional implementation, the third control signal includes a reference signal configuration indication. The target reference signal configuration indication is in the form of an index indicating a target configuration of one or more reference signals used by the UE of the multiple reference signal configurations.

[0320] According to a 24th aspect provided in addition to any one of the 18th to 23rd aspects, the processing circuit determines one or more (blank) periods during which the UE is allowed to skip one or more of receiving downlink communication from the base station and transmitting uplink communication to the base station. The transmitter transmits a fourth control signal to all UEs or a group of UEs in the wireless cell. The fourth control signal is common to the wireless cell or the group of UEs and indicates the one or more (blank) periods. In an optional implementation, the one or more (blank) periods are defined per time slot of a subframe, or per OFDM symbol of a time slot, or per subframe of a frame, or per frame, or per certain duration.

[0321] According to a twenty-fifth aspect provided in addition to the twenty-fourth aspect, the processing circuit determines one (blank) period and a duration of the one (blank) period. The fourth control signal indicates the one (blank) period and the duration. The one (blank) period starts at a time after transmitting the fourth control signal and stops after the duration of the one (blank) period ends. In an optional implementation, the one period is applied periodically with a certain time period. Alternatively, the processing circuit determines a pattern of a certain (blank) period among a plurality of (blank) period patterns. The fourth control signal indicates the determined pattern of the (blank) period. In an optional implementation, the transmitter transmits a (blank) period pattern setting signal for setting a plurality of (blank) period patterns.

[0322] According to a twenty-sixth aspect provided in addition to the twenty-fourth aspect, the processing circuit determines a slot format of a plurality of slot formats and includes a slot format indicator SFI in the fourth control signal that identifies the determined slot format, the slot format defining how each OFDM symbol of the slot is used. the slot format defines each OFDM symbol in the slot as a downlink, an uplink or a flexible OFDM symbol, and the processing circuitry, in operation, determines that each flexible OFDM symbol is one of the (blank) periods; or The slot format defines each OFDM symbol in the slot as a downlink OFDM symbol, an uplink OFDM symbol, a flexible OFDM symbol or a (blank) OFDM symbol during which the UE is permitted to skip one or more of receiving downlink communications from the base station and transmitting uplink communications to the base station, and in operation the processing circuitry determines that each (blank) of the OFDM symbols during which the UE is permitted to skip one or more of receiving downlink communications from the base station and transmitting uplink communications to the base station is one of the (blank) periods.

[0323] According to a 27th aspect provided in addition to any one of the 18th to 26th aspects, a processing circuit includes: - skipping monitoring of a downlink control channel for a period of time; - switching to a target search space set group indicated by a fifth control signal; and The UE determines whether to instruct the UE to perform one or both of the following: The transmitter transmits a fifth control signal to all UEs or a group of UEs in the radio cell, the fifth control signal being common to the radio cell or the group of UEs and instructing the determined instruction. In an optional implementation, the fifth control signal is specific to the UE and has a lower priority than other control signals instructing the UE to perform one of skipping monitoring the downlink control channel and switching to the target search space set group.

[0324] According to a 28th aspect provided in addition to the 18th, 21st, 23rd, 24th and 27th aspects, any combination of two or more of the first to fifth control signals is transmitted by the base station to the UE in the same message.

[0325] According to a twenty-ninth aspect, a method for transmitting a signal to a base station, the method comprising: determining an operational target bandwidth part BWP; transmitting a first control signal to all UEs or a group of UEs in a radio cell, the first control signal being common to the radio cell or the group of UEs and indicating a target BWP; operating according to the indicated target BWP; A method is provided, comprising:

[0326] According to a 30th aspect, there is provided an integrated circuit that, in operation, controls a process of a user equipment (UE), the process being executed by the user equipment (UE), receiving a first control signal from a base station, the first control signal being common to a radio cell to which the UE belongs or to a group of UEs, the first control signal indicating an operating target bandwidth part BWP; operating according to the indicated target BWP; An integrated circuit is provided, comprising:

[0327] According to a thirty-first aspect, there is provided an integrated circuit that, in operation, controls a process of a base station, the process being executed by the base station, determining an operational target bandwidth part BWP; transmitting a first control signal to all UEs or a group of UEs in a radio cell, the first control signal being common to the radio cell or the group of UEs and indicating a target BWP; operating according to the indicated target BWP; An integrated circuit is provided, comprising:

[0328] Further variations including hardware and software implementations of the present disclosure The present disclosure can be realized by software, hardware, or software interlocked with hardware. Each functional block used in the description of each embodiment above can be partially or entirely realized by an LSI such as an integrated circuit, and each process described in each embodiment can be partially or entirely controlled by the same LSI or a combination of LSIs. The LSI may be formed as an individual chip, or a single chip may be formed to include some or all of the functional blocks. The LSI may include data input / output coupled thereto. Here, the LSI may be called an IC (integrated circuit), a system LSI, a super LSI, or an ultra LSI depending on the degree of integration. However, the technology for realizing the integrated circuit is not limited to the LSI, and may be realized using a dedicated circuit, a general-purpose processor, or a processor for a specific application. Furthermore, an FPGA (Field Programmable Gate Array) that can be programmed after the manufacture of an LSI or a reconfigurable processor that can reconfigure the connection and settings of the circuit cells arranged inside the LSI may be used. The present disclosure can be realized as digital processing or analog processing. If future integrated circuit technologies replace LSI as a result of advances in semiconductor technology and other derived technologies, the functional blocks can be integrated using the future integrated circuit technologies. Biotechnology can also be applied.

[0329] The present disclosure may be implemented by any type of apparatus, device or system having communication capabilities, referred to as a communications apparatus.

[0330] A communication device may include a transceiver and processing / control circuitry. The transceiver may include and / or function as a receiver and a transmitter. The transceiver as a transmitter and receiver may include a Radio Frequency (RF) module including amplifiers, RF modulators / demodulators, etc., and one or more antennas.

[0331] Some non-limiting examples of such communications devices include telephones (e.g., mobile (cell) phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, netbooks), cameras (e.g., digital still / video cameras), digital players (digital audio / video players), wearable devices (e.g., wearable cameras, smart watches, tracking devices), game consoles, digital book readers, telehealth / telemedicine (remote health and remote medical) devices, and vehicles (e.g., automobiles, airplanes, ships) that provide communications capabilities, and various combinations thereof.

[0332] The communications apparatus is not limited to being portable or mobile, but may include any type of apparatus, device or system that is non-portable or fixed, such as smart home devices (e.g., appliances, lighting, smart meters, control panels), vending machines, and any other "thing" in an "Internet of Things (IoT)" network.

[0333] Communications may include, for example, exchanging data via cellular systems, wireless LAN systems, satellite systems, and the like, as well as various combinations thereof.

[0334] A communications apparatus may include devices such as a controller or a sensor coupled to the communications device to perform the communications functions described in this disclosure. For example, a communications apparatus may include a controller or a sensor that generates control or data signals used by the communications device to perform the communications functions of the communications apparatus.

[0335] Additionally, the communications equipment may include infrastructure facilities such as, for example, base stations, access points, and any other equipment, devices, or systems that communicate with or control equipment such as those in the non-limiting examples above.

[0336] (Control signal) In this disclosure, the downlink control signal (information) related to this disclosure may be a signal (information) transmitted via a PDCCH of a physical layer, or may be a signal (information) transmitted via a MAC control element (CE) or RRC of a higher layer. The downlink control signal may be a predefined signal (information).

[0337] The uplink control signal (information) related to the present disclosure may be a signal (information) transmitted via a PUCCH of a physical layer, or may be a signal (information) transmitted via a MAC CE or RRC of a higher layer. Also, the uplink control signal may be a predefined signal (information). The uplink control signal may be replaced by uplink control information (UCI), first stage sidelink control information (SCI), or second stage SCI.

[0338] (base station) In the present disclosure, the base station may be, for example, a Transmission Reception Point (TRP), a cluster head, an access point, a Remote Radio Head (RRH), an eNodeB (eNB), a gNodeB (gNB), a Base Station (BS), a Base Transceiver Station (BTS), a base unit, or a gateway. Also, in sidelink communication, a terminal may be employed instead of the base station. The base station may be a relay device that relays communication between an upper node and a terminal. The base station may be a roadside unit.

[0339] (uplink / downlink / sidelink) The present disclosure may be applied to any of the uplink, downlink, and sidelink.

[0340] The present disclosure may apply, for example, to uplink channels such as PUSCH, PUCCH, and PRACH, downlink channels such as PDSCH, PDCCH, and PBCH, and sidelink channels such as the Physical Sidelink Shared Channel (PSSCH), the Physical Sidelink Control Channel (PSCCH), and the Physical Sidelink Broadcast Channel (PSBCH).

[0341] The PDCCH, PDSCH, PUSCH, and PUCCH are examples of a downlink control channel, a downlink data channel, an uplink data channel, and an uplink control channel, respectively. The PSCCH and PSSCH are examples of a sidelink control channel and a sidelink data channel, respectively. The PBCH and PSBCH are examples of a broadcast channel, and the PRACH is an example of a random access channel.

[0342] (Data Channel / Control Channel) The present disclosure may be applied to both data channels and control channels. The channels in the present disclosure may be replaced with data channels including PDSCH, PUSCH, and PSSCH, and / or control channels including PDCCH, PUCCH, PBCH, PSCCH, and PSBCH.

[0343] (reference signal) In this disclosure, a reference signal is a signal known to both a base station and a mobile station, and each reference signal may be referred to as a reference signal (RS) or, in some cases, a pilot signal. A reference signal may be any of a DMRS, a Channel State Information-Reference Signal (CSI-RS), a Tracking Reference Signal (TRS), a Phase Tracking Reference Signal (PTRS), a Cell-specific Reference Signal (CRS), and a Sounding Reference Signal (SRS).

[0344] (Time Interval) In the present disclosure, the time resource unit is not limited to one or a combination of a slot and a symbol, and may be a time resource unit such as a frame, a superframe, a subframe, a slot, a time slot subslot, a minislot, or a time resource unit such as a symbol, an Orthogonal Frequency Division Multiplexing (OFDM) symbol, a Single Carrier-Frequency Division Multiplexing Access (SC-FDMA) symbol, or other time resource unit. The number of symbols included in one slot is not limited to any number of symbols exemplified in the above embodiment(s), and may be other numbers of symbols.

[0345] (Frequency Band) The present disclosure may be applied to both licensed and unlicensed bands.

[0346] (communication) The present disclosure may be applied to any of communication between a base station and a terminal (Uu link communication), communication between terminals (sidelink communication), and vehicle to everything (V2X) communication. The channels in the present disclosure may be replaced with PSCCH, PSSCH, physical sidelink feedback channel (PSFCH), PSBCH, PDCCH, PUCCH, PDSCH, PUSCH, and PBCH.

[0347] The present disclosure may also be applied to any of terrestrial networks and non-terrestrial networks (NTN: Non-Terrestrial Networks) using satellites or High Altitude Pseudo Satellites (HAPS). The present disclosure may also be applied to networks with large cell sizes and terrestrial networks with large delays compared to the symbol length or slot length, such as ultra-wideband transmission networks.

[0348] (Antenna port) An antenna port refers to a logical antenna (antenna group) formed by one or more physical antennas (multiple possible). That is, an antenna port does not necessarily refer to one physical antenna, but may refer to an array antenna formed by multiple antennas. For example, the number of physical antennas forming an antenna port is not defined, and instead, an antenna port is defined as the smallest unit by which a terminal can transmit a reference signal. Also, an antenna port may be defined as the smallest unit for multiplying the weighting of a precoding vector.

[0349] Furthermore, the various embodiments may be implemented by means of software modules which are executed by a processor or directly in hardware. A combination of software modules and hardware implementations may also be possible. The software modules may be stored in any kind of computer-readable storage medium, for example RAM, EPROM, EEPROM, flash memory, registers, hard disks, CD-ROM, DVD, etc. Furthermore, it should be noted that individual features of the different embodiments may be the subject of another embodiment, either individually or in any combination.

[0350] Those skilled in the art will recognize that numerous changes and / or modifications may be made to the present disclosure as shown in the specific embodiments, and the present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

1. A user equipment (UE), A receiver for receiving, in operation, a first control signal from a base station, the first control signal being common to a radio cell or a group of UEs to which the UE belongs, the first control signal indicating an operational target bandwidth part (BWP); In operation, a processing circuit operates in accordance with the indicated target BWP; A user equipment (UE) comprising:

2. The processing circuitry operates to determine a currently active BWP, and if the determined currently active BWP differs from the indicated target BWP, switch from the determined currently active BWP to the indicated target BWP; Optionally, the processing circuitry, in operation, performs BWP-related functions based on the target BWP, and optionally the BWP-related functions include one or more of a random access procedure, measurements, and monitoring a downlink control channel. The UE of claim 1.

3. The target BWP is A default BWP configured in the UE; An initial BWP configured in the UE; A dormant BWP configured in the UE; a first non-dormant BWP configured in the UE; a common BWP configured in the UE, the common BWP being common to all UEs in the radio cell of the base station or common to a group of the UEs; It is one of the The target BWP has a narrower, wider, or the same frequency bandwidth as the currently active BWP.

3. The UE according to claim 1 or 2.

4. The first control signal indicating the operation target BWP is A downlink control information (DCI) message, optionally comprising: DCI message for paging, A DCI message for notifying one or more of a slot format and a search space set group switch, for example, a DCI message having a format of DCI format 2_0 of a 3GPP communication system; A DCI message for notifying power saving information, for example, a DCI message having a format of DCI format 2_6 of the 3GPP communication system; a DCI message for informing one or more of whether to start monitoring for a paging control signal and whether a reference signal is available, for example, a DCI message having a format of DCI format 2_7 of a 3GPP communication system; the downlink control information DCI message comprising one of: Radio resource control (RRC) protocol messages; a control element of a medium access control (MAC) protocol; The UE according to any one of claims 1 to 3, wherein the UE is one of the following:

5. the first control signal indicates the operational target BWP based on a target BWP indicator having one or more bits and identifying the target BWP among a set of BWPs; Optionally, the receiver, in operation, receives a BWP setting signal for setting the set of BWPs. A UE according to any one of claims 1 to 4.

6. the first control signal common to a group of UEs includes a plurality of information blocks, the UE being associated with at least one of the plurality of information blocks, the processing circuitry in operation determining an information block associated with the UE, optionally the first control signal being a downlink control information message having a format of DCI format 2_6 of a 3GPP communication system; or the first control signal common to a group of UEs is addressed to an identifier associated with the group of UEs; the first control signal common to the radio cells is addressed to an identifier common to the entire radio cell; A UE according to any one of claims 1 to 5.

7. In operation, the receiver receives from the base station a second control signal common to the radio cell or group of UEs to which the UE belongs, the second control signal indicating a target SSB pattern to be used by the UE, the target SSB pattern including one or more SSBs of a set of candidate synchronization signal blocks (SSBs); the processing circuitry, in operation, performs SSB-related functions based on the target SSB pattern indicated by the second control signal, and optionally, the SSB-related functions include one or more of serving cell measurements, time synchronization, and frequency synchronization. A UE according to any one of claims 1 to 6.

8. The second control signal includes an SSB pattern indication for indicating the target SSB pattern, the SSB pattern indication being in the form of a bitmap, each bit being associated with one candidate SSB of the set of candidate SSBs and indicating whether the respective candidate SSB is to be transmitted; Optionally, each of the one or more candidate SSBs used by the UE may be configured to include the following parameters: a time domain period and offset of the candidate SSB; A sequence used for the synchronization signal of the candidate SSB; the beam index of the candidate SSB; the transmission power of the candidate SSB; a transmission power gap of the candidate SSB compared to a cell-defined SSB; and A radio resource of a physical random access channel associated with the candidate SSB; A channel raster of the candidate SSBs; The UE of claim 7, defined by one or more of:

9. In operation, the receiver receives from the base station a third control signal common to the radio cell or group of UEs to which the UE belongs, the third control signal indicating a target configuration of one or more reference signals to be used by the UE from a set of reference signal configurations; The reference signal is one or more of a channel state information (CSI) reference signal and a tracking reference signal (TRS); Optionally, the processing circuitry, in operation, performs reference signal related functions based on the indicated target reference signal configuration, and optionally the reference signal related functions include one or more of channel condition measurement, interference measurement, beam management, time tracking, and frequency tracking. A UE according to any one of claims 1 to 8.

10. The third control signal includes a reference signal configuration indication, and the target reference signal configuration indication is in the form of an index indicating one reference signal configuration among a plurality of reference signal configurations; Optionally, each set of reference signal configurations comprises the following parameters: Time radio resources, Frequency radio resources, a sequence of said reference signals; Scramble ID, Quasi-collocation QCL criteria, a transmission power gap compared to a reference synchronization signal block; 10. The UE of claim 9, wherein the UE is defined by one or more of:

11. In operation, the receiver receives a fourth control signal from the base station, the fourth control signal being common to a radio cell or group of UEs to which the UE belongs, the fourth control signal indicating one or more time periods during which the UE is allowed to skip one or more of receiving downlink communications from the base station and transmitting uplink communications to the base station; Optionally, the one or more periods are defined per time slot of a subframe, or per OFDM symbol of a time slot, or per subframe of a frame, or per frame, or in units of duration. A UE according to any one of claims 1 to 10.

12. the fourth control signal indicates a time period and indicates a duration of the time period, the time period starting at a time after receiving the fourth control signal and stopping after the duration of the time period has ended, optionally the time period being applied periodically over a period of time; or the fourth control signal indicates a period pattern among a plurality of period patterns, and optionally, the receiver receives, in operation, a period pattern setting signal for setting the plurality of period patterns. The UE of claim 11.

13. the fourth control signal includes a slot format indicator SFI, and in operation the processing circuit determines the indicated one or more periods based on a value of the included SFI and an association between different slot format definitions and different SFI values, the slot format defining how each OFDM symbol of a slot is used; Optionally, the slot format defines each OFDM symbol in the slot as a downlink, uplink, or flexible OFDM symbol, and the processing circuitry in operation determines that some or each flexible OFDM symbol is in one of the periods; or the slot format defines each OFDM symbol of a slot as a downlink OFDM symbol, an uplink OFDM symbol, a flexible OFDM symbol, or an OFDM symbol for which the UE is permitted to skip one or more of receiving downlink communications from the base station and transmitting uplink communications to the base station, and in operation the processing circuitry determines that each of the OFDM symbols for which the UE is permitted to skip one or more of receiving downlink communications from the base station and transmitting uplink communications to the base station is one of the periods. The UE of claim 11.

14. In operation, the receiver receives a fifth control signal from the base station, the fifth control signal being common to the radio cell or the group of UEs to which the UE belongs, the fifth control signal comprising: skipping monitoring of a downlink control channel for a period of time; Switching to a target search space set group indicated by the fifth control signal; instructing the UE to perform one or both of Optionally, the fifth control signal is specific to the UE and has a lower priority than other control signals instructing the UE to perform one of skipping monitoring the downlink control channel and switching to a target search space set group. A UE according to any one of claims 1 to 13.

15. The UE of claim 1, 7, 9, 11 or 14, wherein any combination of two or more of the first to fifth control signals are transmitted by the base station to the UE in the same message.

16. 15. The UE of claim 1, 7, 9, 11, or 14, wherein any one or more of the first to fifth control signals is one of higher layer signals of a medium access control (MAC) control element, a radio resource control (RRC) message addressed to one or more UEs, and a system information broadcast message.

17. Executed by the user equipment UE, receiving a first control signal from a base station, the first control signal being common to a radio cell to which the UE belongs or a group of UEs, the first control signal indicating an operating target bandwidth part (BWP); operating according to the indicated target BWP; A method comprising:

18. a processing circuit for determining an operational target bandwidth part (BWP) during operation; In operation, a transmitter for transmitting a first control signal to all UEs or a group of UEs in a radio cell, the first control signal being common to the radio cell or the group of UEs and indicating the target BWP; Equipped with The processing circuitry, in operation, operates according to the indicated target BWP. Base station.

19. The processing circuitry may include, as the target BWP: A default BWP configured in the UE; An initial BWP configured in the UE; A dormant BWP configured in the UE; a first non-dormant BWP configured in the UE; a common BWP configured in the UE, the common BWP being common to all UEs in the radio cell of the base station or common to a group of the UEs; The base station of claim 18, further comprising:

20. the first control signal indicates the operational target BWP based on a target BWP indicator having one or more bits and identifying the target BWP among a set of BWPs; Optionally, the transmitter, in operation, transmits a BWP setting signal to set the BWP set. A base station according to claim 18 or 19.

21. The processing circuitry operates to determine a target synchronization signal block (SSB) pattern; In operation, the transmitter transmits a second control signal to all UEs or a group of UEs in the radio cell, the second control signal indicating the target SSB pattern that is common to the radio cell or the group of UEs and includes one or more SSBs of a set of candidate SSBs used by the UEs and the base station; the processing circuitry, in operation, performs an SSB-related function based on the target SSB pattern indicated by the second control signal. A base station according to any one of claims 18 to 20.

22. 22. The base station of claim 21, wherein the second control signal includes an SSB pattern indication for indicating the target SSB pattern, the SSB pattern indication being in the form of a bitmap, each bit being associated with one candidate SSB of the set of candidate SSBs and indicating whether the respective candidate SSB is to be transmitted or not.

23. The processing circuitry, in operation, determines a target setting for one or more reference signals used by the UE and the base station; In operation, the transmitter transmits a third control signal to all the UEs or a group of UEs in the radio cell, the third control signal being common to the radio cell and the group of UEs and indicating the target configuration of one or more reference signals of a set of reference signal configurations; The reference signal is one or more of a channel state information (CSI) reference signal and a tracking reference signal (TRS); Optionally, the third control signal includes a reference signal configuration indication, the target reference signal configuration indication being in the form of an index indicating a target configuration of one or more reference signals to be used by the UE among a plurality of reference signal configurations. A base station according to any one of claims 18 to 22.

24. The processing circuitry, in operation, determines one or more time periods during which the UE is allowed to skip one or more of receiving downlink communications from the base station and transmitting uplink communications to the base station; In operation, the transmitter transmits a fourth control signal to all the UEs or a group of UEs in the radio cell, the fourth control signal being common to the radio cell or the group of UEs and indicating the one or more time periods; Optionally, the one or more periods are defined per time slot of a subframe, or per OFDM symbol of a time slot, or per subframe of a frame, or per frame, or in units of duration. A base station according to any one of claims 18 to 23.

25. the processing circuitry, in operation, determines a time period and a duration of the time period, the fourth control signal indicating the time period and the duration, the time period starting at a time after transmitting the fourth control signal and stopping after the duration of the time period has ended, optionally the time period being applied periodically over a period of time; or the processing circuit, in operation, determines a period pattern among a plurality of period patterns, the fourth control signal indicates the determined period pattern, and optionally, the transmitter, in operation, transmits a period pattern setting signal for setting the plurality of period patterns.

25. The base station of claim 24.

26. In operation, the processing circuit determines a slot format of a plurality of slot formats and includes a slot format indicator SFI in the fourth control signal that identifies the determined slot format, the slot format defining how each OFDM symbol of the slot is used; Optionally, the slot format defines each OFDM symbol in the slot as a downlink, uplink, or flexible OFDM symbol, and in operation the processing circuitry determines that each flexible OFDM symbol is one of the periods; or the slot format defines each OFDM symbol of a slot as a downlink OFDM symbol, an uplink OFDM symbol, a flexible OFDM symbol, or an OFDM symbol for which the UE is permitted to skip one or more of receiving downlink communications from the base station and transmitting uplink communications to the base station, and in operation the processing circuitry determines that each of the OFDM symbols for which the UE is permitted to skip one or more of receiving downlink communications from the base station and transmitting uplink communications to the base station is one of the periods.

25. The base station of claim 24.

27. The processing circuitry, in operation, skipping monitoring of a downlink control channel for a period of time; Switching to a target search space set group indicated by the fifth control signal; determining whether to instruct the UE to perform one or both of The transmitter, in operation, transmits a fifth control signal to all the UEs or group of UEs in the radio cell, the fifth control signal being common to the radio cell or group of UEs and indicating the determined instruction; Optionally, the fifth control signal is specific to the UE and has a lower priority than other control signals instructing the UE to perform one of skipping monitoring the downlink control channel and switching to a target search space set group. A base station according to any one of claims 18 to 26.

28. The base station of claim 18, 21, 23, 24 or 27, wherein any combination of two or more of the first to fifth control signals are transmitted by the base station to the UE in the same message.

29. Executed by the base station, determining an operational target bandwidth part BWP; transmitting a first control signal to all UEs or a group of UEs in a radio cell, the first control signal being common to the radio cell or the group of UEs and indicating the target BWP; operating according to the indicated target BWP; A method comprising:

30. an integrated circuit which, in operation, controls a process of a user equipment (UE), the process being executed by the user equipment (UE); receiving a first control signal from a base station, the first control signal being common to a radio cell to which the UE belongs or a group of UEs, the first control signal indicating an operating target bandwidth part (BWP); operating according to the indicated target BWP; 4. An integrated circuit comprising:

31. an integrated circuit which, in operation, controls a process of a base station, said process being executed by said base station; determining an operational target bandwidth part BWP; transmitting a first control signal to all UEs or a group of UEs in a radio cell, the first control signal being common to the radio cell or the group of UEs and indicating the target BWP; operating according to the indicated target BWP; 4. An integrated circuit comprising:

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