Method performed by user equipment, method performed by network node, user equipment and network node

Abstract

A wireless communication system comprising at least one RAN node, and at least one UE that supports SSB adaptation mechanisms and procedures for the provision of NCD-SSBs and / or CD-SSBs to UEs in RRC Connected and for performing Layer-1 (L1) measurements using NCD-SSBs.

Description

METHOD PERFORMED BY USER EQUIPMENT, METHOD PERFORMED BY NETWORK NODE, USER EQUIPMENT AND NETWORK NODE

[0001] The present disclosure relates to a communication system and to parts thereof.

[0002] The disclosure has particular but not exclusive relevance to wireless communication systems and devices thereof operating according to the 3rd Generation Partnership Project (3GPP) standards or equivalents or derivatives thereof (including Long-Term Evolution (LTE)-Advanced, Next Generation or 5G / 6G networks, future generations, and beyond). The present disclosure in particular, but not exclusively, relates Synchronization Signal Block (SSB) adaptation mechanisms and procedures for the provision of NCD-SSBs and / or CD-SSBs to UEs in RRC Connected (or RRC Idle / Inactive) and for performing Layer-1 (L1) measurements using NCD-SSBs.

[0003] Earlier developments of the 3GPP standards were referred to as the LTE of Evolved Packet Core (EPC) network and Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), also commonly referred as '4G'. More recently, the term '5G' and 'new radio' (NR) has started to be used to refer to an evolving communication technology that is expected to support a variety of applications and services. Various details of 5G networks are described in, for example, the 'NGMN 5G White Paper' V1.0 by the Next Generation Mobile Networks (NGMN) Alliance, which document is available from https: / / www.ngmn.org / 5g-white-paper.html. 3GPP intends to support 5G by way of the so-called 3GPP Next Generation (NextGen) radio access network (RAN) and the 3GPP NextGen core network.

[0004] Under the 3GPP standards, a NodeB (or an eNB in LTE, and gNB in 5G) is the radio access network (RAN) node (or simply 'access node', 'access network node' or 'base station') via which communication devices (user equipments or 'UEs') connect to a core network and communicate with other communication devices or remote servers. For simplicity, the present application will use the term access network node, RAN node or base station to refer to any such access nodes.

[0005] For simplicity, the present application will use the term mobile device, user device, or UE to refer to any communication device that is able to connect to the core network via one or more RAN nodes. Although the present application may refer to mobile devices in the description, it will be appreciated that the technology described can be implemented on any communication devices (mobile and / or generally stationary) that can connect to a communication network for sending / receiving data, regardless of whether such communication devices are controlled by human input or software instructions stored in memory.

[0006] In the current 5G architecture, the gNB structure may be split into two or more parts. In some RAN implementations there are two parts, known as the Central Unit (CU or gNB-CU) - sometimes referred to as a 'control unit' - and the Distributed Unit (DU or gNB-DU), connected by an F1 interface. This enables the use of a 'split' architecture in which the typically 'higher' CU layers (for example, but not necessarily or exclusively, Packet Data Convergence Protocol (PDCP) and Radio Resource Control (RRC) layers) and the 'lower' DU layers (for example, but not necessarily or exclusively, Radio Link Control (RLC), Media (sometimes referred to as 'Medium') Access Control (MAC), and Physical (PHY) layers) are separated between a particular CU, and one or more DUs that are connected to and controlled by that CU via the F1 interface. Thus, for example, the higher layer CU functionality for a number of gNBs may be implemented centrally (for example, by a single processing unit, or in a cloud-based or virtualised system), whilst retaining the lower layer DU functionality locally separately for each gNB.

[0007] With the increasing usage of mobile communication for a wide range of different use cases, additional frequencies and bands are needed to accommodate this increasing demand. Accordingly, a variety of different frequency bands are available for 5G NR. These frequency bands include many of the existing frequency bands used by previous generations of telecommunication technology and many new frequency bands including bands in the millimetre wave region. The bandwidth available for frequency bands in the millimetre wave region is very much higher than for frequency bands used by earlier generations and thus allow for greater data speeds to be achieved albeit at the expense of the range of the signals.

[0008] The available frequency bands are grouped into two different frequency ranges referred to as frequency range 1 (FR1) containing the lower frequency bands and frequency range 2 (FR2) containing the higher frequency bands. FR1 bands are likely to carry much of the traditional cellular mobile communication traffic whereas the FR2 bands are aimed at providing short range very high data rate capability for 5G radio. Originally the FR1 band was intended to define bands below 6 GHz, but with anticipated additional spectrum allocations, the FR1 range has now been extended to 7.125 GHz.

[0009] Furthermore, as cellular communication systems evolve, there is also an increasing need for wireless communication networks having improved energy efficiency. This need is being driven, for example, by the fact that 5G (and beyond) communication systems are becoming more pervasive across industries and geographical areas, handling more advanced services and applications requiring very high data rates. Moreover, networks are becoming denser, use more antennas, larger bandwidths, and more frequency bands.

[0010] A reduction in the amount of energy needed to operate a communication network beneficially reduces both the operational expenditure or (OPEX), and the environmental impact, of operating the system. Moreover, for battery-powered devices (for example, a UE) reduced power consumption extends the battery life of the device. However, more recent developments of cellular communication systems (for example to implement wide channel bandwidths, to enable operations at significantly higher frequencies than previously, to provide improved capacity, and the like) tend to increase, rather than reduce, power demand and thus present significant challenges when it comes to energy saving.

[0011] In this context, a number of network energy saving (NES) techniques are typically implemented in cellular communication systems, and improvements to those NES techniques and completely new techniques are being developed. The NES techniques being considered include time, frequency, spatial, and power domain adaptation techniques.

[0012] One method of achieving energy savings in a cellular communication system is to reduce the energy requirements associated with communication between a UE and an associated RAN node. The energy consumption arising from such communication includes a dynamic part that is associated with data transmission and reception, and a static part that is associated with operations of the UE, and the RAN node, that are performed even when there is no ongoing data transmission or reception. The static part may include, for example, the power required to operate a UE in a mode in which the UE is able to receive and decode a physical downlink control channel (PDCCH) transmitted by a RAN node.

[0013] Energy saving modes may be configured for one or more devices in the system (e.g., a UE). For example, a UE may be configured to operate in an energy saving mode (which may also be referred to as a sleep mode) in which the UE performs a reduced number of transmissions, or in which the UE is configured not to attempt to transmit and / or to receive signals during a particular time period. Such operation is commonly referred to as DRX / DTX which stands for Discontinuous Reception (DRX) and Discontinuous Transmission (DTX). DRX for a UE includes idle mode DRX and connected mode DRX (C-DRX). In idle mode DRX, the UE periodically wakes up to monitor for paging messages and goes back to a sleep mode if paging message is not intended for it. In C-DRX, the UE powers down most of its circuitry when there are no packets to be received or transmitted. During this time, the UE nevertheless still monitors for a physical downlink control channel (PDCCH) occasionally during a DRX 'active' state, or DRX 'ON' period. The time during which UE does not monitor the PDCCH is often called a DRX 'sleep' or 'inactive' state, or DRX 'OFF' period.

[0014] However, most of the energy consumption (and associated OPEX), comes from the radio access network. In view of this, therefore, there remains an ongoing need to develop techniques for achieving more efficient operation (dynamically and / or semi-statically) at the RAN side, and potentially adaptation of transmissions and / or receptions for NES in time, frequency, spatial, and / or power domains with a finer granularity than is currently possible.

[0015] One NES technique that is being developed to help address this involves discontinuous operation of the cell or cells provided by a RAN node in a similar manner to DTX / DRX at the UE. This is often referred to as 'cell DTX / DRX'. With cell DTX / DRX, the RAN node operating a cell stops transmitting and receiving in that cell during certain periods of time. The UEs that are served by the cell may be provided with information that allows them to determine when the RAN node is in an active or 'ON' state (and is therefore able to communicate with the UE) and when it is in an inactive or 'OFF' state (and is therefore not able to communicate with the UE).

[0016] Earlier NES development has also focused, primarily, on NES enhancements aimed at reducing energy associated with connected mode UEs during a low cell load scenario. These enhancements deliberately avoided any impact on idle or legacy UE operation and focused on reducing energy associated with user specific signals and channels. However, this focus has limited the NES gains that are potentially achievable, especially in the RAN.

[0017] More recently, therefore, a number of procedures have been developed to reduce the amount of energy expenditure associated with idle / inactive mode UEs selecting, camping on, and / or reselecting cells. Much of the energy expenditure associated with these procedures arises from the transmission, reception, and processing of the minimum system information that a RAN node periodically sends to provide a UE with the parameters required for initial access to the cell and acquisition of any other system information.

[0018] Part of the minimum system information is carried by the SSBs which are periodically transmitted in the cells of the communication system. The PBCH in the SSB carries a master information block (MIB) that provides an initial part of the minimum system information. The MIB typically includes, for example, information identifying whether the cell is or is not barred for access, and information allowing subsequent acquisition of the remaining minimum system information (carried by system information block 1 (SIB1)). The minimum system information carried by the MIB and SIB1 effectively provides the UE with the parameters required for initial access to the cell and acquisition of any other system information.

[0019] To help reduce energy expenditure associated with the transmission, reception, and processing of the minimum system information, therefore, techniques / procedures are being developed to avoid unnecessary SSB and / or SIB1 transmission. By way of example, such techniques / procedures may include: -　　The application of 'SSB-less' or 'SIB1-less' operation in certain 'non-anchor' cells, which involves not transmitting SSBs or SIB1s in those cells. Instead, a UE may rely on an SSB or SIB1 transmission in a different 'anchor' cell for acquiring synchronisation and / or minimum system information; -　　The use of on-demand transmission, rather than automatic (periodic) transmission, of SSBs for camping onto certain cells (e.g., secondary cells (SCells) and / or non-serving cells) by UEs configured to connect to, and use, such cells; and -　　The use of on-demand transmission, rather than automatic (periodic) transmission, of system information block 1 (SIB1) for certain cells in which a UE is able to retrieve the system information carried by SIB1 by sending an uplink wake-up signal (WUS) to a corresponding RAN node and can perform synchronisation based on another cell in which SIB1 is transmitted.

[0020] NPL 1: 'NGMN 5G White Paper' V1.0 by the Next Generation Mobile Networks (NGMN), available from https: / / www.ngmn.org / 5g-white-paper.html.

[0021] The work to date on network energy savings has led to some agreement in relation to, and associated specification of, a number of techniques - primarily for RRC Connected, user specific signals and channels, and low load scenarios. These techniques include, for example: aspects of SSB-less secondary cell operation for inter-band carrier aggregation for FR1 and co-located cells, enhancement on cell DTX / DRX mechanism including the alignment of cell DTX / DRX and UE DRX in an RRC connected mode; and inter-node information exchange on cell DTX / DRX. The techniques also include, for example, techniques in spatial and power domains to enable efficient adaptation of spatial elements; efficient adaptation of power offset values between physical downlink shared channel (PDSCH) and CSI-RS; mechanisms to inhibit legacy UEs from camping on cells adopting newer NES techniques (i.e., so-called 'NES Cells'); conditional handover (CHO) procedural enhancement; inter-node beam activation; and enhancements on restricting paging in a limited area.

[0022] More recently, 5G Reduced Capability (RedCap) - also known as 5G NR-Light - has been proposed that is a variant of 5G designed for applications that do not require high-performance attributes of conventional 5G technologies; in particular RedCap aims to meet the requirements of RedCap devices (e.g., IoT devices such as smartwatches, wearables, industrial sensors, and the like) that do not need to support high-performance attributes of conventional 5G technologies.

[0023] As part of the development of RedCap, Cell-Defining (CD) and Non-Cell-Defining (NCD) SSBs have been defined.

[0024] CD-SSBs are SSBs associated with remaining minimum system information (RMSI) and are located on the synchronisation raster. Such CD-SSBs are similar to conventional SSBs in that they are associated with a SIB1 and may be used by UEs (e.g., RedCap UEs) for cell detection and initial attach. The configuration of CD-SSBs transmitted in a cell is typically provided to a UE by a RAN node as part of a serving cell configuration for that cell (e.g., as part of a ServingCellConfigCommon IE, or the like) via an appropriate RRC message, or the like.

[0025] The serving cell configuration associated with the CD-SSBs may, for example, include: an indication of time domain position of the transmitted CD-SSBs (e.g., in an ssb-PositionsInBurst IE); an indication of a periodicity of the transmitted CD-SSBs (e.g., in an ssb-periodicity IE); an indication of a subcarrier spacing (SCS) of the transmitted CD-SSBs (e.g., in an ssbSubcarrierSpacing IE); a transmission power that may be used by the network for transmission of the CD-SSBs (e.g., in an ss-PBCH-BlockPower IE); a physical cell identifier (PCI) associated with the CD-SSBs, as well as other appropriate parameters / IEs.

[0026] Moreover, as part of the CD-SSB configuration, the RAN node also typically provides an SSB frequency of the CD-SSBs for the SCell (e.g., in an absoluteFrequencySSB IE within e.g., an FrequencyInfoDL IE, or the like).

[0027] Cell configurations associated with NCD-SSBs carry most of the same (or similar) information as for a CD-SSB except that they are not associated with SIB1 (or any other SIB) of a cell. Such NCD-SSBs are single-frequency signals that do not contain any information about the cell identity or location. They are therefore less complex and more power-efficient than the CD-SSBs. NCD-SSBs are typically used by UEs (e.g., RedCap UEs) for basic cell detection purposes like time synchronisation; radio link monitoring / measurement (RLM); beam failure detection (BFD); radio resource management (RRM); and the like. It will be appreciated that as such NCD-SSBs are not associated with SIB1 (or any other SIB) of a cell they cannot be used by UEs (e.g., RedCap UEs) for initial attach.

[0028] For example, as with the serving cell configuration for CD-SSBs, the configuration for NCD-SSBs may carry information such as an indication of time domain position of the transmitted NCD-SSBs (e.g., in an ssb-PositionsInBurst IE); an indication of a subcarrier spacing (SCS) of the transmitted NCD-SSBs (e.g., in an ssbSubcarrierSpacing IE); a transmission power that may be used by the network for transmission of the NCD-SSBs (e.g., in an ss-PBCH-BlockPower IE); a physical cell identifier (PCI) associated with the NCD-SSBs, as well as other appropriate parameters / IEs.

[0029] Moreover, as part of the NCD-SSB configuration, the RAN node also typically provides a SSB frequency of the NCD-SSBs for the SCell and an indication of a periodicity of the transmitted NCD-SSBs. For example, the configuration for the NCD-SSBs may include an absoluteFrequencySSB IE within e.g., an FrequencyInfoDL IE, or the like (or alternatively an absoluteFrequencySSB-r17 IE within a NonCellDefiningSSB-r17 IE contained with a BWP-DownlinkDedicated IE, or the like) to indicate a SSB frequency of the NCD-SSBs for the SCell. Similarly, the configuration for the NCD-SSBs may include an ssb-periodicity IE (or alternatively an ssb-periodicity-r17 IE) to indicate a periodicity of the NCD-SSBs.

[0030] Alternatively, an indication of an SSB frequency of the NCD-SSBs for the SCell (e.g., in an absoluteFrequencySSB IE) and an indication of a periodicity of the transmitted NCD-SSBs (e.g., in an ssb-periodicity IE) may be provided by the network explicitly (e.g., via dedicated signalling separate from a transmission of the NCD-SSB configuration), and which may be used as a quasi-co-location (QCL) source and / or which may be used for random access channel (RACH) occasion (RO) selection.

[0031] It will be appreciated that the transmission (Tx) power used by a RAN node to transmit NCD-SSBs may be the same as, or different from, the Tx power used by the RAN node 5 to transmit CD-SSBs. For example, when a RAN node is to transmit CD-SSBs and NCD-SSBs, it may not be able to use the same Tx power for both the CD-SSBs and the NCD-SSBs if power boosting procedures are to be implemented (or are implemented) for the transmission of CD-SSBs. In this scenario a UE may be to be informed of the difference in Tx power between the transmission of NCD-SSBs and CD-SSBs to ensure that the UE is able to correctly receive both types of SSB transmissions. Such power differences may be indicated to the UE via an appropriate IE in the corresponding CD-SSB configuration and NCD-SSB configuration (e.g., ss-PBCH-BlockPower IE, or the like).

[0032] It will also be appreciated that the periodicity of the transmitted NCD-SSBs configured by the NCD-SSB configuration (or which is alternatively indicated by the network explicitly via, for example dedicated signalling) as described above does not have to be configured the same as the periodicity for the transmission of CD-SSBs over a servicing cell. Instead, the periodicity of the transmitted NCD-SSBs may be configured to typically be less than the periodicity configured for the transmission of CD-SSBs over a serving cell and no greater than 160 ms.

[0033] Once configured, those CD-SSBs and / or NCD-SSBs can also be used for the purposes of performing RRM measurements on the serving cell associated with the CD-SSBs. For example, if configured with NCD-SSBs, the UE may perform RRM measurements based on the NCD-SSBs that are available within the active bandwidth part (BWP) for the serving cell assuming that the CD-SSBs are outside of the active BWP for the serving cell.

[0034] Once configured, a UE in RRC IDLE / INACTIVE state (mode) can perform RRC IDLE / INACTIVE mobility procedures, or the like, based on measurements performed by the UE on CD-SSBs.

[0035] Once configured, a UE in RRC CONNECTED state (mode) can perform RRM measurements on neighbouring cells based on CD-SSBs and / or NCD-SSBs for neighbouring cells. In this scenario, configuration-type information associated with the NCD-SSBs of the neighbouring cells that may be required to use the NCD-SSBs (e.g., the frequency of the NC-SSBs, the periodicity of the NCD-SSBs, the SCS of the NCD-SSBs, or the like) may be provided to the UE when the UE is configured to perform cell identification and / or cell measurements using the NCD-SSBs of the neighbouring cells.

[0036] However, the implementation and use of CD-SSBs and NCD-SSBs in communication systems (e.g., communication systems that include RedCap UEs) is still in its infancy, as such the maximum potential of using such CD-SSBs and NCD-SSBs has not yet been reached. Further adaptations of CD-SSBs and NCD-SSBs are therefore desirable. In particular, it would be beneficially to adapt SSB configurations, and the like, to enhance the provision of NCD-SSBs to UEs when in RRC CONNECTED state (mode), and to allow those UEs to use such NCD-SSBs to perform Layer-1 (L1) type measurements.

[0037] The disclosure aims to describe one or more apparatus and / or one or more associated mechanisms / procedures that at least partially addresses or contributes to meeting one or more of the above needs and / or addressing one or more of the above issues.

[0038] The disclosure has a method performed by a User Equipment, UE, the method comprising receiving, from a network node, first information indicating N periodicities for a Synchronization Signal Block, SSB, for a cell, wherein N is larger than one; and receiving the SSB from the network node.

[0039] The disclosure has a method performed by a network node, the method comprising transmitting, to User Equipment, UE, first information indicating N periodicities for a Synchronization Signal Block, SSB, for a cell, wherein N is larger than one; and transmitting the SSB to the UE.

[0040] The disclosure has a User Equipment, UE, comprising means for receiving, from a network node, first information indicating N periodicities for a Synchronization Signal Block, SSB, for a cell, wherein N is larger than one; and means for receiving the SSB from the network node.

[0041] The disclosure has a network node comprising means for transmitting, to User Equipment, UE, first information indicating N periodicities for a Synchronization Signal Block, SSB, for a cell, wherein N is larger than one; and means for transmitting the SSB to the UE.

[0042] The various functional means described below that are part of the UE may be provided by a memory and one or more processors that execute instructions stored in the memory. Similarly, the various functional means described below that are part of the access network node may be provided by a memory and one or more processors that execute instructions stored in the memory.

[0043] Various example described below may be implemented by means of a computer program product comprising computer implementable instructions for causing a programmable computer to carry out any of the methods described below. The computer implementable instructions may be provided as a signal or on a tangible computer readable medium.

[0044] Examples of apparatus and methods will now be described, by way of example, with reference to the accompanying drawings in which:

[0045] Fig. 1 schematically illustrates a ('cellular' or 'wireless') communication system;Fig. 2 schematically illustrates a RAN node of the communication system and anchor / non-anchor cell coverage provided by the RAN node to a UE;Fig. 3 illustrates an example adapted SSB configuration for NCD-SSBs that may be provided to a UE to configure NCD-SSBs for a SCell (UE in RRC CONNECTED);Fig. 4 illustrates an example procedure for configuring and activating / deactivating a UE to use the adapted SSB configuration for NCD-SSBs described with reference to Fig. 3;Fig. 5 illustrates an example procedure for configuring CSI reporting that may be implemented in the communication system of Fig. 1;Fig. 6 illustrates an example adapted SSB configuration indication that may be provided to a UE to configure NCD-SSBs for a SCell (UE in RRC IDLE / INACTIVE);Fig. 7 is a simplified block schematic illustrating the main components of a UE for implementation in the communication system of Fig. 1; andFig. 8 is a simplified block schematic illustrating the main components of a RAN node for implementation in the communication system of Fig. 1.

[0046] <Overview> 　　An exemplary communication system will now be described in general terms, by way of example only, with reference to Fig. 1.

[0047] Fig. 1 schematically illustrates a mobile ('cellular' or 'wireless') communication system 1 to which the examples described herein are applicable.

[0048] In the communication system 1 user equipment (UEs) 3 (3-1, 3-2, 3-3) (e.g., mobile telephones and / or other mobile or stationary devices) can communicate with each other via a (radio) access network ((R)AN) node 5 that operates according to one or more compatible radio access technologies (RATs). In the illustrated example, the RAN node 5 comprises a base station 5 or 'gNB' 5 operating one or more associated cells. Communication via the RAN node 5 is typically routed through a core network 7 (e.g., a 5G / 6G core network evolved packet core network (EPC)) or any other core network.

[0049] As those skilled in the art will appreciate, whilst three UEs 3 and one RAN node 5 are shown in Fig. 1 for illustration purposes, the system, when implemented, will typically include other RAN nodes 5 and UEs 3.

[0050] Each RAN node 5 controls one or more associated cells either directly, or indirectly via one or more other nodes (such as home base stations, relays, remote radio heads, distributed units, and / or the like). It will be appreciated that the RAN nodes 5 may be configured to support 4G, 5G, 6G and / or later generations, and / or any other 3GPP or non-3GPP communication protocols.

[0051] The UEs 3 and their serving RAN node 5 are connected via an appropriate air interface (for example the so-called 'Uu' interface and / or the like). Neighbouring RAN nodes 5 may be connected to each other via an appropriate base station to base station interface (such as the so-called 'X2' interface, 'Xn' interface, and / or the like).

[0052] The core network 7 includes a number of logical nodes (or 'functions') for supporting communication in the communication system 1. In this example, the core network 7 comprises control plane functions (CPFs) 10 and one or more network node entities for the communication of user data (e.g., user plane functions (UPFs)) 11. The CPFs 10 include one or more network node entities for the communication of control signalling (e.g., Access and Mobility Management Functions (AMFs)) 10-1 , one or more network node entities for session management (e.g., Session Management Functions (SMFs)) 10-2 and a number of other functions 10-n (such as, for example an Authentication Server Function (AUSF) which facilitates 5G security processes).

[0053] The RAN node 5 is connected to the core network nodes via appropriate interfaces (or 'reference points') such as an N2 reference point between the RAN node 5 and the AMF 10-1 for the communication of control signalling, and an N3 reference point between the RAN node 5 and each UPF 11 for the communication of user data. The UEs 3 are each connected to the AMF 10-1 via a non-access stratum (NAS) connection over an appropriate reference point (e.g. N1 reference point (analogous to the S1 reference point in LTE)). It will be appreciated that N1 communication are routed transparently via the RAN node 5.

[0054] Each UPF 11 is connected to an external data network 20 (e.g., an IP network such as the internet) via an appropriate reference point (e.g., N6 reference point) for communication of the user data.

[0055] The AMF 10-1 performs mobility management related functions, maintains the NAS connection with each UE 3 and manages UE registration. The AMF 10-1 is also responsible for managing paging. The AMF 10-1 receives user information sent through the network and forwards the information to the SMF 10-2.

[0056] The SMF 10-2 is connected to the AMF 10-1 via an appropriate reference point (e.g., N11 reference point). The SMF 10-2 provides session management functionality (that formed part of MME functionality in LTE) and additionally combines some control plane functions (provided by the serving gateway and packet data network gateway in LTE). The SMF 10-2 uses user information provided via the AMF 10-1 to determine what session manager would be best assigned to the user. The SMF 10-2 may be considered effectively to be a gateway from the user plane to the control plane of the network. The SMF 10-2 also allocates IP addresses to each UE 3.

[0057] The RAN node 5 of the communication system 1 is configured to operate at least one cell on an associated time-division duplex (TDD) carrier that operates in unpaired spectrum and / or at least one cell on an associated frequency-division duplex (FDD) carrier that operates in paired spectrum.

[0058] The RAN node 5 is also configured for transmission of, and the UEs 3 are configured for the reception of, control information and user data via a number of downlink (DL) physical channels and for transmission of a number of physical signals. The DL physical channels correspond to resource elements (REs) carrying information originated from a higher layer, and the DL physical signals are used in the physical layer and correspond to REs which do not carry information originated from a higher layer.

[0059] The DL physical channels may include, for example, a physical downlink shared channel (PDSCH), a physical broadcast channel (PBCH), and a physical downlink control channel (PDCCH). The PDSCH carries data sharing the PDSCH's capacity on a time and frequency basis. The PDSCH can carry a variety of items of data including, for example, user data, UE-specific higher layer control messages mapped down from higher channels, system information blocks (SIBs), and paging. The PDCCH carries downlink control information (DCI) for supporting a number of functions including, for example, scheduling the downlink transmissions on the PDSCH and also the uplink data transmissions on a physical uplink shared channel (PUSCH). The PBCH provides UEs 3 with the Master Information Block (MIB). It also, in conjunction with the PDCCH, supports the synchronisation of time and frequency, which aids cell acquisition, selection and re-selection.

[0060] The RAN node 5 also transmits DL physical signals that do not carry any data, such as, for example, reference signals (RSs) and synchronization signals (SSs). A reference signal (sometimes known as a pilot signal) is a signal with a predefined special waveform known to both the UE 3 and the RAN node 5. The reference signals may include, for example, cell specific reference signals, UE-specific reference signal (UE-RS), downlink demodulation signals (DMRS), and channel state information reference signal (CSI-RS).

[0061] Similarly, the UEs 3 are configured for transmission of, and the RAN node 5 is configured for the reception of, control information and user data via a number of uplink (UL) physical channels corresponding to REs carrying information originated from a higher layer, and UL physical signals which are used in the physical layer and correspond to REs which do not carry information originated from a higher layer. The physical channels may include, for example, the PUSCH, a physical uplink control channel (PUCCH), and / or a physical random-access channel (PRACH). The UL physical signals may include, for example, demodulation reference signals (DMRS) for an UL control / data signal, and / or sounding reference signals (SRS) used for UL channel measurement.

[0062] < Control Information> 　　In the communication system 1 the RAN node 5 is configured to transmit control information to the UE 3 using one or more control resource sets (CORESETs). A CORESET is a set of time-frequency resources within which the UE 3 can search for DCI transmitted by a RAN node 5 on a PDCCH. A CORESET is analogous to the control region at the start of subframes in earlier generations of communication technology. Unlike earlier generations, however, in which the frequency domain of the control region typically corresponded to the total system bandwidth, the frequency domain location for CORESET is localised to a specific region in the frequency domain and has a variable width that can be set to any suitable value (typically in multiples of six resource blocks where each resource block comprises twelve subcarriers in the frequency domain).

[0063] A number of different DCI formats can be used by the RAN node 5, depending on requirements, for transmission on a PDCCH corresponding to one of the PDCCH candidates in one of the search spaces configured for a given UE 3. For example, the RAN node 5 may be able to transmit DCI using one or more of the currently standardised DCI formats as set out in Table 1.

[0064] Different DCI formats may or may not have the same DCI size. Moreover, DCI may be addressed (scrambled) using different radio network temporary identifiers (RNTIs) that a UE 3 may monitor for. Typically, a UE 3 is capable of monitoring up to three different DCI sizes for DCI formats using a cell RNTI (C-RNTI) - typically used as an identifier for scheduling purposes. Additionally, a UE 3 is typically capable of monitoring one additional DCI size using other RNTIs for specific purposes (e.g., a slot format indication RNTI (SFI-RNTI), interruption RNTI (INT-RNTI), or the like). This constraint is sometimes referred to as the "3+1" size budget and is imposed because a DCI scrambled with a C-RNTI is, generally, more time critical than a DCI scrambled with a RNTI used for another specific purpose, and so requires the UE 3 to decode it promptly in order to be able to process the scheduled data transmission.

[0065] To take account of the constraint imposed by the DCI size budget, the sizes of some DCI formats may be aligned by padding, truncation, and / or determining a frequency domain resource assignment field differently.

[0066] A UE 3 may monitor a set of PDCCH candidates in one or more control resource sets (CORESETs) on an active DL bandwidth part, where monitoring implies decoding each PDCCH candidate according to the monitored DCI formats. The number of blind decodes (BDs) may be restricted on a per carrier basis of a serving cell. The number of BDs may refer to the number of monitored PDCCH candidates or the number of PDCCH candidates a UE is capable of decoding within a certain time frame, such as a slot or span of consecutive symbols in a slot. As an example, at a 15 kHz subcarrier spacing (SCS), the maximum number of BDs per slot per serving cell supported by a UE 3 may be 44 BDs.

[0067] <Synchronisation Signal Blocks (SSBs)> 　　The RAN node 5 is also configured to transmit synchronisation signal blocks (SSBs) periodically in the cell or cells that it operates. The SSB includes both synchronisation signals (e.g., a primary synchronisation signal (PSS) and a secondary synchronisation signal (SSS)) and the PBCH carrying a MIB that provides at least part of the minimum system information for accessing the corresponding cell (e.g., parameters required for acquiring system information block 1 (SIB1) which carries other minimum system information).

[0068] Each UE 3 may receive an SSB, and the UE 3 may assume that reception occasions of a PBCH, PSS and SSS are in consecutive symbols from the SSB (also referred to as a SS / PBCH block). The PSS is a part of the SSB that aids in initial cell detection and synchronization. It provides coarse timing and frequency synchronization for UEs. The PSS consists of a predefined sequence of complex-valued symbols transmitted over a specific frequency range. The SSS is another component of the SSB that provides additional information for fine-grained synchronization and cell identification. It carries the cell identity group and provides the necessary information to determine the exact physical cell ID (PCI) of the serving cell (e.g., a unique identifier assigned to each cell within the network that helps UEs differentiate between neighbouring cells and synchronize with the correct cell.

[0069] The RAN node 5 may transmit several SSBs corresponding to different DL beams. The total number of SSBs may be confined, for example, within a 5 ms duration as an SS burst. The periodicity of the SSB transmissions may be indicated to the UE using any suitable signalling (e.g., per serving cell using ssb-periodicityServingCell). The periodicity value for the SSB may be, for example, greater than or equal to 20 ms. For initial cell selection, the UE 3 may be configured to assume that an SS burst occurs with a periodicity of 2 frames. The UE 3 may also be provided with an indication of which SSBs within a 5 ms duration are transmitted (e.g., using ssb-PositionsInBurst). The UE 3 may also be provided with an indication of an absolute transmit power value of the SSS (e.g., using ss-PBCH-BlockPower) which may range from -60 to 50 dBm. Furthermore, the UE 3 may also be provided with an indication of the subcarrier spacing (SCS) used for the SSB (e.g., using ssbSubcarrierSpacing). It will be appreciated that all indications to the UE 3 about the SSB may be indicated to the UE 3 via any appropriate information element (IE) (e.g., ServingCellConfigCommon provided in a SIB1 message, or any other appropriate dedicated message).

[0070] Each UE 3 is configured to search for SSBs when scanning for a primary cell (PCell) to camp on and to decode the associated PBCH before proceeding to decode other system information transmitted on the PDSCH. Each UE 3 is also configured to perform measurements on specific resources configured for the SSBs, for example reference signal received power (RSRP), reference signal received quality (RSRQ), and / or signal to interference and noise ratio (SINR) measurements or the like. Each UE 3 may also be configured to perform radio resource management (RRM) measurements when triggered to do so by a RAN node 5.

[0071] Each UE 3 may also be configured to search for SSBs associated with SCells when scanning for SCells to camp on and to decode the associated PBCH before proceeding to decode other system information transmitted on the PDSCH, rather than rely on SSBs associated with the PCell. Given that SCells are not typically used by UEs 3 all the time, each UE 3 may be configured to perform on-demand SSB searching to search for SSBs associated with SCells only when the UE 3 (or network) decides that it wishes to utilise one or more SCells.

[0072] <Cell-Defining (CD) and Non-Cell-Defining (NCD) SSBs> 　　The RAN node 5 and UEs 3 of the communication system 1 are also configured to support Cell-Defining (CD) and Non-Cell-Defining (NCD).

[0073] Specifically, the RAN node 5 is configured to provide configuration information for CD-SSBs transmitted in an SCell to a UE 3 as part of a serving cell configuration for that cell (e.g., as part of a ServingCellConfigCommon IE, or the like) via an appropriate RRC message, or the like. The serving cell configuration associated with the CD-SSBs may, for example, include: an indication of time domain position of the transmitted CD-SSBs (e.g., in an ssb-PositionsInBurst IE); an indication of a periodicity of the transmitted CD-SSBs (e.g., in an ssb-periodicityServingCell IE); an indication of a subcarrier spacing (SCS) of the transmitted CD-SSBs (e.g., in an ssbSubcarrierSpacing IE); and a transmission power that may be used by the network for transmission of the CD-SSBs (e.g., in an ss-PBCH-BlockPower IE). Moreover the RAN node 5 is configured to provide, as part of the CD-SSB configuration, an SSB frequency of the CD-SSBs for the SCell (e.g., in an absoluteFrequencySSB IE within an FrequencyInfoDL IE, or the like).

[0074] The RAN node 5 is also configured to provide configuration information for NCD-SSBs. For example, the configuration for NCD-SSBs typically includes an appropriate indication of an SSB frequency of the NCD-SSBs for the SCell (e.g., in absoluteFrequencySSB-r17 IE within a NonCellDefiningSSB-r17 IE contained with a BWP-DownlinkDedicated IE, or the like). Additionally, the configuration for NCD-SSBs typically includes an appropriate indication of a periodicity of the NCD-SSB transmissions for the SCells (e.g., in an ssb-periodicity-r17 IE), and an appropriate indication of a timing offset for the NCD-SSB transmissions for the SCells (e.g., in an ssb-TimeOffset-r17 IE).

[0075] For example, the appropriate indication of the periodicity of the NCD-SSB transmissions for the SCells (e.g., in an ssb-periodicity-r17 IE) may typically indicate a periodicity of one of: 5 ms, 10 ms, 20 ms, 40 ms, 80 ms, or 160 ms. Similarly, the appropriate indication of the timing offset for the NCD-SSB transmissions for the SCells (e.g., in an ssb-TimeOffset-r17 IE) may typically indicate a timing offset of one of: 5 ms, 10 ms, 15 ms, 20 ms, 40 ms, or 80 ms.

[0076] <Channel State Information Reference Signals (CSI-RS) and Demodulation Reference Signals (DMRS)> 　　The RAN node 5 is also configured to transmit reference signals (RS) in the one or more cells that it operates. These reference signals include channel state information RS (CSI-RS) and demodulation RS (DMRS). The CSI-RS may be used by the UE 3 for a number of different purposes including, for example, CSI reporting in which the UE 3 derives channel state information including one or more channel quality indicator(s) (CQI), rank indicator(s) (RI), and / or precoding matrix indicator(s) (PMI) from CSI-RS measurements and reports them to the RAN node 5 in a CSI report.

[0077] The CSI-RS may also be used by the UE 3 for beam management including the refinement of initial beam selection based on SSBs. For example, the RAN node 5 may use a set of relatively broad beams may be used for transmission of the SSBs and a set of narrower (more directional) beams for the CSI-RS. The UE 3 can be configured, by the RAN node 3, to measure each CSI-RS transmission to identify the best CSI-RS beam and to report this to the RAN node 5 (e.g., by means of a CSI report including a CSI-RS indicator (CRI) identifying the strongest CSI-RS and hence CSI-RS beam). The UE 3 may also be configured to report a Layer 1 RSRP (L1-RSRP) and / or Layer 1 signal to interference and noise ratio (L1-SINR) which has been measured for the strongest CSI-RS.

[0078] CSI-RS may either be either zero power (ZP-CSI-RS) or non-zero power (NZP-CSI-RS). NZP-CSI-RS are used for most of the procedures including channel measurement, beam management, beam measurement, connected mode mobility etc. ZP-CSI-RS are empty resource elements, used primarily for interference measurement.

[0079] There are also several other ways in which the CSI-RS may be used including, for example, for connected mode mobility, radio link failure detection, beam failure detection / recovery, and fine timing of time and / or frequency synchronisation.

[0080] The DMRS include DMRS for the PBCH, DMRS for the PDCCH and DMRS for the PDSCH. The DMRS for the PBCH are used by the UE 3 to estimate the propagation channel experienced by the PBCH for the purposes of demodulating the PBCH and subsequent decoding of system information (e.g., carried by the MIB). The DMRS for the PDCCH are used by the UE 3 to estimate the propagation channel experienced by the PDCCH for the purposes of demodulating the PDCCH and subsequent decoding of DCI.

[0081] A DMRS for the PDSCH is transmitted in combination with the associated PDSCH using the same precoding and logical antenna ports. Accordingly the DMRS and associated PDSCH both experience the same combined propagation channel. The DMRS is transmitted using a sequence that is known to the UE 3 and hence the UE 3 can determine the characteristics (propagation coefficients) of the propagation channel based on a comparison of the received DMRS with the original DMRS as transmitted by the RAN node 5. The UE 3 is then able to decode the associated PDSCH based on the derived propagation coefficients.

[0082] Data communicated on the PDSCH (and the associated DMRS) may be transmitted in parallel transmission layers and / or may be beamformed.

[0083] <CSI Reporting> 　　The RAN node 5 can configure how the UE 3 measures and reports CSI using appropriate measurement configuration signalling.

[0084] A CSI report may include a Channel Quality Indicator (CQI), a precoding matrix indicator (PMI), a CSI-RS resource indicator (CRI), SS / PBCH Block Resource indicator (SSBRI), a layer indicator (LI), a rank indicator (RI), a layer 1 reference signal received power (L1-RSRP), a layer 1 signal to interference and noise ratio (L1-SINR), and / or a Capability[Set]Index. A CSI report may be sent as uplink control information (UCI) in a PUCCH or a UCI part of a PUSCH.

[0085] The CQI is an index (typically 4 bits) value representing a signal to interference and noise ratio (SINR). The CQI value also corresponds to a modulation and coding scheme (MCS) to be used for each layer. The RI indicates a number of MIMO transmission layers requested by the UE 3 (albeit the RAN node 5 may not use the requested number of MIMO transmission layers). The PMI is used by the UE 3 to report parameters defining a preferred precoding matrix to be applied for downlink transmissions (albeit the RAN node 5 may not use the requested precoding). A layer indicator (LI) may also be included in the CSI report for identifying the strongest layer from the set of layers indicated by the RI.

[0086] The L1-RSRP and / or L1-SINR may be measured for SSB channel measurement resources or for CSI-RS channel measurement resources.

[0087] The RAN node 5 can, for example, use the measurement configuration signalling (e.g., using a CSI-measconfig IE) to configure the UE 3 to measure and report specific resources used for CSI-RS (e.g., using the CSI-ReportConfig IE). Multiple different reporting configurations can be configured and identified by an appropriate identifier (e.g., a CSI-ReportConfigID IE).

[0088] The RAN node 5 can, for example, configure the UE 3 to provide different types of CSI reports (e.g., using the CSI-ReportConfig IE) providing different information, depending on the requirements for the use case, by setting a reporting quantity parameter (e.g., the reportQuantity IE) appropriately. For example, the reporting quantity may indicate the CSI-related, L1-RSRP-related, or L1-SINR-related quantities to report. The UE 3 may, for example, be configured: to report only RI, and CQI for associated one or more CRIs, by setting the reporting quantity parameter appropriately (e.g., to cri-RI-CQI); to report RI, PMI and CQI for associated one or more CRIs by setting the reporting quantity parameter appropriately (e.g., to cri-RI-PMI-CQI), or to report RI, LI, PMI and CQI for associated one or more CRIs by setting the reporting quantity parameter appropriately (e.g., to cri-RI-LI-PMI-CQI). Similarly, for beam management procedures, the UE 3 may be configured to report RSRP or SINR for associated one or more CRIs, by setting the reporting quantity parameter appropriately (e.g., to cri-RSRP or cri-SINR), to report RSRP or SINR for associated one or more SSBs, by setting the reporting quantity parameter appropriately (e.g., to ssb-Index-RSRP or ssb-Index- SINR).

[0089] The RAN node 5 can also configure the UE 3 to provide CSI reports based on different report timing configurations (e.g., using a reportConfigType IE in the CSI-ReportConfig IE). For example, the UE 3 may be configured for persistent reporting, semi-persistent reporting on the PUSCH, semi-persistent reporting on the PUCCH, or aperiodic reporting. The time domain behaviour of the CSI report configuration indicated by the higher layer report configuration type parameter has a configured periodicity and slot offset that applies in the numerology of the UL BWP in which the CSI report is configured for transmission on.

[0090] Aperiodic reporting and semi-persistent reporting on PUSCH may be triggered using a PUSCH DCI. For example, DCI (e.g., using DCI format 0_1 or DCI format 0_2). For example, CSI reporting may be triggered by the content of a CSI request, included in the DCI, that has a size (in number of bits) corresponding to a higher layer trigger size parameter (e.g., the reportTriggerSize parameter in the case of DCI format 0_1 or the reportTriggerSizeDCI-0-2 in the case of DCI format 0_2). The size of the CSI request field may, for example, be configured to be one of the set of possible numbers of bits: {0, 1, 2, 3, 4, 5, 6}. The CSI request typically has a value that points to a respective index of each of one or more corresponding aperiodic trigger states (e.g., configured in the CSI-AeriodicTriggerStateList IE). Each of these trigger states is associated with one or more corresponding CSI report configurations (e.g., identified by associated CSI-ReportConfig IE or IEs)). The time and frequency resources that can be used by the UE to report CSI are controlled by the RAN node.

[0091] Semi-persistent reporting on PUSCH may be triggered in a similar way (e.g., by use of DCI identifying one or more CSI-ReportConfig IEs of one or more CSI-SemiPersistentOnPUSCH-TriggerStates listed in a CSI-SemiPersistentOnPUSCH-TriggerStateList).

[0092] Semi-persistent reporting on PUCCH may be triggered using a MAC control element (MAC CE).

[0093] Each CSI report configuration identifies at least one CSI resource configuration (e.g., using a CSI-ResourceConfigId IE) for measurement. The identified CSI resource configuration is defined by a corresponding IE (e.g., using a CSI-ResourceConfigId IE) that includes a list of identifiers corresponding to one or more sets of CSI resources (e.g. a list of one or more NZP-CSI-RS-ResourceSetIDs for non-zero power CSI-RS) and associated configuration information. The associated configuration information may, for example, identify an associated bandwidth part (e.g., by means of the BWP ID) and a resource type (e.g., by means of a resourceType IE). The identified resource type may, for example, identify the CSI-RS resource to be a periodic, a semi-persistent, or an aperiodic type. Each resource set comprises one or more specific CSI resource configurations represented by associated identifiers (e.g. NZP-CSI-RS-ResourceIDs for non-zero power CSI-RS) that each point to the specific configuration information (e.g. defined by an NZP-CSI-RS-Resource IE for non-zero power CSI-RS) for that CSI resource configuration).

[0094] For CQI, PMI, CRI, SSBRI, LI, RI, L1-RSRP, L1-SINR, Capability[Set]Index a UE is configured by higher layers with one or more CSI report configuration reporting settings (e.g., defined in the CSI-ReportConfig IE), one or more CSI resource configuration resource settings (e.g., defined in the CSI-ReportConfig IE), and one or two list(s) of trigger states (e.g., given by the higher layer parameter CSI-AperiodicTriggerStateList and / or the higher layer parameter CSI-SemiPersistentOnPUSCH-TriggerStateList). Each trigger state of a list of aperiodic CSI trigger states (e.g., defined by the CSI-AperiodicTriggerStateList IE) may define a list of associated CSI report configurations indicating the resource set IDs for channel measurement and possibly interference measurement. Each trigger state of a list of semi-persistent CSI trigger states (e.g., defined by the CSI-SemiPersistentOnPUSCH-TriggerStateList IE) may contain a single associated CSI report configuration.

[0095] Each reporting setting is associated with a single downlink BWP (e.g., indicated by the higher layer parameter BWP-Id given in an associated CSI-ResourceConfig IE for channel measurement) and contains the one or more parameters for one CSI reporting band: measurement restriction configurations, and the CSI-related quantities to be reported by the UE such as the LI, L1-RSRP, L1-SINR, CRI, and SSBRI.

[0096] Accordingly, the RAN node can configure multiple CSI report configuration instances and CSI resource configuration instances. It will be appreciated that multiple resource sets can be configured per CSI resource config for the case of aperiodic CSI RS resources. The same number of CSI-RS ports are assumed for multiple CSI-RS resources within a given resource set.

[0097] In this way reporting of specific CSI resource sets for specific use cases may be configured. For example, a CSI-RS resource set may be configured that includes CSI-RS resources for different beams for beam management purposes. A CSI-RS resource set may be configured that includes a single CSI-RS resource for a number, N, of ports for channel estimation purposes.

[0098] Different resource sets may also be configured per resource configuration in for the case of multiple transmission reception points (TRPs). In this scenario, different resource sets can be part of same CSI resource configuration for aperiodic CSI reporting or can be part of different CSI resource configuration for periodic / semi-persistent CSI reporting. It will, nevertheless, be appreciated that in the case of the same number of ports for all TRPs it is possible to configure CSI-RS resources belonging to different TRPs within same resource set.

[0099] In another example, a CSI report for multiple secondary cells (SCells) can be triggered together by including CSI reporting configurations for different SCells within the information defining a single CSI aperiodic trigger state.

[0100] The RAN node 5 can also configure the UE 3 to provide either a wideband or a subband granularity of reporting (e.g., using a reportFreqConfiguration IE in a CSI-ReportConfig IE). For example CQI and / or partial PMI can be reported per subband setting a corresponding indicator (e.g., a cqi-FormatIndicator IE and / or a pmi-FormatIndicator IE respectively) appropriately (e.g., to widebandCQI or subbandCQI and / or to widebandPMI or subbandPMI respectively).

[0101] The RAN node 5 can also configure the UE 3 with a time restriction for channel measurements (and / or interference measurements). When the time restriction is configured, the UE 3 is configured to derive the measurements for computing CSI values based only on the last measured CSI-RS occasion associated with the CSI report.

[0102] It will be appreciated that the UE 3 may need to transmit quite a few CSI reports (based on the CSI configuration) but there may be limited space available in PUCCH or uplink control UCI part of the PUSCH. Moreover, the CSI report payload size can increase significantly in presence of subband based reporting. Hence, prioritization rules are defined for indicating which CSI report parameters should be transmitted with the highest priority.

[0103] For CSI reporting of RI, CQI and PMI, a CSI report for a single CSI resource may be divided into two parts: a first part containing RI, CRI, CQI for a first codeword; and a second part containing PMI and CQI for a second codeword. The first part can be transmitted in whole while it is possible to omit a portion of the second part (depending on allowed size of UCI). For UCI coding, the first part of each CSI report is encoded into the UCI, and the second part of the CSI report is encoded based on amount of space available.

[0104] <L1-RSRP computation and reporting> 　　For the purposes of L1-RSRP computation a UE 3 may be configured with CSI-RS resources, SSB resources or both CSI-RS and SSB resources (when resource-wise 'type C' and / or 'type D' quasi co-located where applicable).

[0105] A UE 3 may typically be configured with a CSI-RS resource setting of up to 16 CSI-RS resource sets typically having up to 64 resources within each set. The total number of different CSI-RS resources over all resource sets is generally no more than 128.

[0106] For the purposes of L1-RSRP reporting, a higher layer parameter may be provided in the CSI report configuration to indicate the number (N) of measured RS resources to be reported per report setting in a non-group-based report (e.g., indicated by a nofReportedRS IE in the CSI-ReportConfig IE). The value of the parameter (N) is less than or equal to a maximum value (N_max) which may be either 2 or 4 depending on the capability of the UE 3. When the field is absent the UE 3 applies a value of one. Where the number of measured RS is configured to be one, the reported L1-RSRP value is defined by a 7-bit value (e.g., corresponding to a L1-RSRP value in the range [-140, -44] dBm with 1dB step size). If the higher layer parameter is configured to be larger than one, or when group based beam reporting is enabled (e.g., if a higher layer parameter groupBasedBeamReporting is configured as 'enabled', or if a higher layer parameter groupBasedBeamReporting-r17 is configured) the UE 3 uses differential L1-RSRP based reporting. For differential based reporting, the largest measured value of L1-RSRP is quantised to a 7-bit value (e.g., in the range [-140, -44] dBm with 1dB step size) and other measured values of L1-RSRP are represented as differential L1-RSRP values, relative to the largest measured value, quantised to a 4-bit value. The differential L1-RSRP value is typically computed with 2 dB step size relative to the largest measured L1-RSRP value which is part of the same L1-RSRP reporting instance.

[0107] Moreover, when group based beam reporting is enabled (e.g., when the higher layer parameter groupBasedBeamReporting-r17 is configured in the CSI-ReportConfig IE), the UE 3 may also indicate the CSI Resource Set associated with the largest measured value of L1-RSRP, and for each group, CRI or SSBRI of the indicated CSI Resource Set may be present first.

[0108] A UE 3 may also be configured with a number of additional PCIs for L1-RSRP reporting of SSB resources (e.g., by means of an SSB-MTC-AddtionalPCI). When one or more additional PCIs are configured, a resource set configured for SSB resource related L1-RSRP CSI reporting (e.g., defined by a CSI-SSB-ResourceSet IE) may include a set of SSB indices and a set of PCI indices, where each SSB index is associated with a PCI index.

[0109] < L1-SINR measurement and reporting> 　　When one resource setting is configured, the resource setting (e.g., given by a higher layer parameter resourcesForChannelMeasurement) is for channel and interference measurement on NZP CSI-RS for L1-SINR computation. In this case the UE 3 may assume that the same single port NZP CSI-RS resource(s) (with density of three REs per RB) is used for both channel and interference measurements.

[0110] When two resource settings are configured, the first resource setting (e.g., given by a higher layer parameter resourcesForChannelMeasurement) is for channel measurement on an SSB or on NZP CSI-RS, and the second resource setting (e.g. given by either higher layer parameter csi-IM-ResourcesForInterference or higher layer parameter nzp-CSI-RS-ResourcesForInterference) is for interference measurement performed on CSI-IM or on a single port NZP CSI-RS (with density of three REs per RB), where each SSB or NZP CSI-RS resource for channel measurement is associated with one CSI-IM resource or one NZP CSI-RS resource for interference measurement by the ordering of the SSB or NZP CSI-RS resource for channel measurement and CSI-IM resource or NZP CSI-RS resource for interference measurement in the corresponding resource sets. The number of SSB(s) or CSI-RS resources for channel measurement equals the number of CSI-IM resources or the number of NZP CSI-RS resources for interference measurement.

[0111] A UE 3 may apply the SSB, or a 'typeD' reference signal configured with a QCL type set to 'typeD' for the corresponding NZP CSI-RS resource for channel measurement, as the 'reference' reference signal for determining a 'type D' assumption for the corresponding CSI-IM resource, or the corresponding NZP CSI-RS resource for interference measurement, configured for one CSI reporting. A UE 3 may expect that the NZP CSI-RS resource set for channel measurement and the NZP-CSI-RS resource set for interference measurement, if any, are configured with a higher layer 'repetition' parameter (set to 'ON') indicating that resources within the resource set are transmitted with the same downlink spatial domain transmission filter.

[0112] <Triggering / Activation of CSI Reporting for the possible CSI-RS Configurations> 　　As explained above, the reporting configuration for CSI can be aperiodic (using PUSCH), periodic (using PUCCH), or semi-persistent (using PUCCH or DCI activated PUSCH). Similarly, the CSI-RS transmissions which are used to derive the CSI measurements can be periodic, semi-persistent, or aperiodic (e.g., an aperiodic CSI report can be generated based on periodic CSI-RS transmissions).

[0113] Periodic CSI reporting requires periodic CSI-RS transmission, both of which are configured and initiated by higher layer (e.g., RRC) signalling.

[0114] Semi-persistent CSI reporting on the PUCCH, for both semi-persistent and periodic CSI-RS transmission, are activated / deactivated by an activation command using an appropriate MAC control element (MAC CE) (e.g., a 'semi-persistent CSI reporting on PUCCH activation / deactivation' MAC CE). Semi-persistent CSI-RS transmission is also activated / deactivated by an activation command using an appropriate MAC CE (e.g., using a 'semi-persistent CSI-RS / CSI IM resource set activation / deactivation' MAC CE).

[0115] In contrast, semi-persistent CSI reporting on the PUSCH, for both semi-persistent and periodic CSI-RS transmission, is triggered using the CSI request field, as described earlier, in DCI (e.g., using DCI format 0_1 or DCI format 0_2) with cyclic redundancy bits scrambled appropriately (e.g., using a semi-persistent CSI radio network temporary identifier - SP-CSI-RNTI). Semi-persistent CSI reporting is not, however, supported for aperiodic CSI-RS transmission.

[0116] Aperiodic CSI reporting for periodic, semi-persistent, and aperiodic CSI-RS transmission are also all triggered using the CSI request field in the DCI (e.g., using DCI format 0_1 or DCI format 0_2) for semi-persistent, periodic, or aperiodic CSI-RS transmission.

[0117] Aperiodic CSI-RS transmission is also triggered using the CSI request field in the DCI (e.g., using DCI format 0_1 or DCI format 0_2).

[0118] The supported combinations of CSI Reporting configurations and CSI-RS Resource configurations, and how the CSI Reporting is triggered for each CSI-RS Resource configuration, is summarised below in Table 2.

[0119] <SSBs in the context of Carrier Aggregation (CA)> 　　In the communication system 1, increases in bandwidth, and thereby bitrate can be achieved through carrier aggregation (CA), whereby multiple frequency blocks, i.e., component carriers (CCs), are assigned to the same UE 3 for use. Each CC in turn serves a cell which provides a particular bandwidth and set of services to the UE 3. For example, in CA each UE 3 has a first CC that provides a primary cell (PCell) that carries traffic and RRC signalling messages and may additionally any number of other CCs that each provide their own corresponding secondary cell (SCell) which carry traffic alone. The SCells are optional, and are added, removed, and / or reconfigured are required by the UE 3 and the network.

[0120] In CA, when initially scanning for a cell to camp on each UE 3 scans for a PCell. The PCell serves as the main point of communication between the UE 3 and the RAN node 5 and is responsible for all control information signalling (e.g., RRC Configuration signalling), non-access stratum (NAS) signalling, and the like, between the UE 3 and the network, as well as initial data transmissions. The PCell typically offers a high bandwidth for low latency data transmission. It will be appreciated that when initially scanning for a PCell to camp on each UE 3 searches for SSB as described previously to enable efficient cell searching for, and initial access to the PCell.

[0121] As and when required, the UE 3 may be triggered to search for, and camp on one or more secondary cells (SCells) to provide additional capacity and adaptability in the network. For example, the UE 3 may be triggered to search for, and camp on one or more SCells to provide extra bandwidth when the network is experiencing high data traffic or congestion. Additionally, or alternatively, SCells may be camped on to provide specific specialist services, for example, the UE 3 may camp onto a SCell that caters for Internet-of-Things (IoT) devices, high-definition data streaming, or the like.

[0122] The UEs 3 may be configured to camp onto SCells using a so-called 'SSB-less' procedure, where an SSB from the PCell is used for time / frequency synchronization, layer-1 (L1) / layer-3 (L3) measurements, SCell activation procedures, and the like. However, such an SSB-less procedure is most appropriately suited to scenarios where the CA is intra-band e.g., the PCell and the SCells operate on different frequencies within a specific frequency band such as the FR1 band (e.g., DL: 150 MHz to 7650 MHz, UL: 2300 MHz to 29250 MHz).

[0123] A group of serving cells associated with a master RAN Node may be referred to as a master cell group (MCG). The MCG typically comprises a so called special cell (SpCell) which is the PCell (Primary Cell), and one or more SCells. A group of serving cells associated with a secondary RAN Node may be referred to as a secondary cell group (SCG). The SCG typically comprises an SpCell, which is known as a primary SCell (PSCell) in this case, and one or more SCells.

[0124] It will be appreciated that where the CA is inter-band e.g., the PCell and the SCells operate on different frequencies within different frequency bands such as the FR1 band (e.g., DL: 150 MHz to 7650 MHz, UL: 2300 MHz to 29250 MHz) and FR2 band respectively (e.g., DL / UL: 28 GHz and 29 GHz) SSB-less procedures for camping onto SCells may prove difficult as the time / frequency synchronization information (and the like) associated with the PCell on FR1 may not be appropriate for the SCells on FR2. In such cases the use of dedicated SSBs for SCells (e.g., on-demand SSBs for SCells) may be beneficial to ensure appropriate SCell activation procedures and RRM measurement procedures are performed for the SCell, and that correct SCell timing synchronization is achieved.

[0125] In such scenarios each UE 3 may be configured to search for SSBs associated with SCells when scanning for SCells to camp on and to decode the associated PBCH before proceeding to decode other system information transmitted on the PDSCH as described above, rather than rely on SSBs associated with the PCell. Given that SCells are not typically used by UEs 3 all the time, each UE 3 may be configured to acquire SSBs on-demand SSB and to search for SSBs associated with SCells only when the UE 3 (or network) decides that it wishes to utilise one or more SCells.

[0126] There are a number of scenarios to which such on demand SSB transmission for an SCell may be appropriate. For example, a scenario involving a downlink only SCell that is otherwise without SSB transmission but with tracking reference signals (TRS) / aperiodic TRS (A-TRS) DL transmissions, a scenario involving an SCell that is otherwise without SSB transmission and without any other downlink transmissions, but with uplink reception at the NW side), and / or the like.

[0127] On-demand SSB transmission may be enabled semi-statically or dynamically. For example, common channel adaptation and / or on-demand SSB may be enabled via dedicated RRC signalling on a PCell and / or PScell if the UE has a PCell and / or PScell connection. On-demand SSB may be enabled via system information (e.g., where the content of system information includes a carrier indication field to indicate the applicable carrier / cell for the enabling of on-demand SSB transmission). On-demand SSB may be enabled via a DCI with an appropriate DCI format (e.g., DCI format 1_0 with a cyclic redundancy check (CRC) scrambled with a system information RNTI (SI-RNTI), for example that includes a carrier indication field to indicate the applicable carrier / cell for the system information to be transmitted.

[0128] By way of example, Fig. 2 schematically illustrates a RAN node 5 of the communication system 1 and PCell and SCell (e.g., an NES Cell) coverage provided by the RAN node 5 to a UE 3.

[0129] As shown in Fig. 2, in the illustrated example, the RAN node 5 provides a first serving (primary) cell (PCell) over which CD-SSBs may be transmitted to the UE 3 by the RAN node 5. Additionally, the RAN node 5 also provides one or more other cells (other than the PCell) for the UE 3 to communicate via using CA. In this example, the RAN node 5 provides a secondary cell (SCell) that a UE 3 may access at some later time after initially camping onto the serving cell.

[0130] As shown in Fig. 2, the SCell may be a cell that is a smaller cell overlapping with, or wholly incorporated within, the PCell. The SCell, unlike the PCell, may be a cell over which UEs cannot (or at least cannot routinely) receive SSBs and / or system information (e.g., SIB messages). For example, a SCell may be configured as an SSB-less cell or a cell in which SSBs are not sent periodically, but rather are sent on an on-demand basis. Additionally, those SSBs for a SCell may, for example be NCD-SSBs. As such SCells may be configured to not (or at least not routinely) provide SSBs and / or system information, and / or provide only NCD-SSBs as described above, thereby providing network energy savings to the communication system, they may also be referred to as NES Cells.

[0131] It will be appreciated, nevertheless, that in the case where the SSBs for the SCell are NCD-SSBs further enhancements would be advantageous to meet the requirements of different use cases of such SCells. For example, in cases where the SSBs for the SCell are NCD-SSBs, it might be advantageous to extend the periodicity range of the NCD-SSBs (i.e., the periodicity at which the NCD-SSBs can be transmitted over the SCell) to meet the requirements of different use cases.

[0132] By way of example only, the periodicity of NCD-SSBs transmitted over the SCell may be configured to be less than the periodicity for CD-SSBs transmitted over the serving cell (e.g., PCell) when the NCD-SSBs are configured for random-access channel (RACH) occasion (RO) selection, particularly in cases where PRACH adaptation is implemented (e.g., additional PRACH resources are provided / indicated to the UE, and / or PRACH resources are configured in a pattern using a cell discontinuous reception (DRX) configuration, or the like).

[0133] In another example, the periodicity of NCD-SSBs transmitted over the SCell may be extended in cases where periodic CD-SSBs are transmitted during a cell discontinuous transmission (DTX) active duration to allow the NCD-SSBs, for example, to be configured during a cell DTX inactive duration. It would, therefore, be particularly advantageous to introduce mechanisms for allowing SSB adaptation to support different use cases, e.g., by providing adapted configurations for NCD-SSBs to meet the requirements of the different use cases of NCD-SSBs in SCells (e.g., NES Cells). Beneficially therefore, the communication system 1 may be configured to implement one or more enhancements to support extended / adapted SSB configurations, for the purposes of SSB adaptation.

[0134] For example, the UEs 3 and RAN node 5 of the communication system 1 may be mutually configured to support SSB adaptation for NCD-SSB for connected mode NES capable UEs 3 in an SCell. Moreover, the UEs 3 and RAN node 5 of the communication system 1 may be mutually configured to support an extended SSB periodicity value range for the purposes of such NCD-SSB adaptation.

[0135] It would also be advantageous to introduce mechanisms for allowing SSB adaptation in the time domain.

[0136] For example, the UEs 3 and RAN node 5 of the communication system 1 may be mutually configured to support adaptation of SSBs in the time domain based on an RRC configuration. Moreover, the UEs 3 and RAN node 5 of the communication system 1 may be mutually configured to support dynamic SSB adaptation in the time domain (e.g., via DCI). The UEs 3 and RAN node 5 of the communication system 1 may also (or alternatively) be mutually configured to support the provision of a dynamic indication to select / indicate a configuration from multiple possible SSB adaptation configurations. The UEs 3 and RAN node 5 of the communication system 1 may also (or alternatively) be mutually configured to support the provision of a CSI report configuration that is associated both with CD-SSBs and NCD-SSBs (or one of CD-SSBs and NCD-SSBs) based on configuration.

[0137] Specifically, as described in more detail later, the UEs 3 and RAN node 5 of the communication system 1 may be mutually configured to implement one or more mechanisms or procedures to activate / deactivate the use of such extended / adapted SSB configurations for the implementation of extended / adapted NCD-SSBs to provide control over when and if extended / adapted NCD-SSBs for SCells should be used. Moreover, as described in more detail later, the UEs 3 and RAN node 5 of the communication system 1 may be mutually configured to implement one or more mechanisms or procedures to allow configuration of the UE 3 to perform measurements (e.g., Layer-1 type measurements) in respect of both CD-SSBs and NCD-SSBs, or either of CD-SSBs or NCD-SSBs.

[0138] There now follows a description of an example adapted SSB configuration for NCD-SSBs that may be supported in the communication system 1.

[0139] <SSB Configuration Adaptations for UE in RRC CONNECTED> <Example adapted SSB configuration for NCD-SSBs> 　　Fig. 3 illustrates an example adapted SSB configuration for NCD-SSBs that may be provided to a UE 3 by a RAN node 5 to configure NCD-SSBs for a SCell over which the UE 3 and the RAN node 5 may communicate.

[0140] As shown in Fig. 3, there is provided a UE 3 and a RAN node 5 in communication with one another over a serving cell (e.g., a PCell) on which the UE 3 is camped.

[0141] At step S302, an appropriate SSB configuration (or 'SSB adaptation configuration') for a SCell, in the context of when the RAN node 5 wishes to provide on-demand CD-SSBs and / or NCD-SSBs to the UE 3, may be transmitted to the UE 3 by the RAN node 5. That SSB configuration may, for example, be sent to the UE 3 via an appropriate RRC message (e.g., an RRC (re)configuration message, or the like).

[0142] That SSB configuration for the SCell may, for example, include all configuration information / parameters that are typically required for CD-SSBs as previously described. For example, for CD-SSBs, the SSB configuration may include an indication of time domain position of the transmitted CD-SSBs (e.g., in an ssb-PositionsInBurst IE); an indication of a periodicity of the transmitted CD-SSBs (e.g., in an ssb-periodicityServingCell IE); an indication of a subcarrier spacing (SCS) of the transmitted CD-SSBs (e.g., in an ssbSubcarrierSpacing IE); and a transmission power that may be used by the network for transmission of the CD-SSBs (e.g., in an ss-PBCH-BlockPower IE). Moreover the RAN node 5 may also be configured to provide, as part of the SSB configuration, an SSB frequency of the CD-SSBs for the SCell (e.g., in an absoluteFrequencySSB IE within an FrequencyInfoDL IE, or the like).

[0143] Additionally, for NCD-SSBs, the SSB configuration for the SCell may include newly adapted information / parameters compared to those described above for a conventional configuration for NCD-SSBs. For example, for NCD-SSBs, the SSB configuration for the SCell may include (e.g., within an adapted IE such as NonCellDefiningSSB-NES IE, or the like, within an NonCellDefiningSSB-NES IE, or the like): an appropriate indication of an SSB frequency offset of the NCD-SSBs for the SCell (e.g., in offsetFrequencyNCDSSB-r19 IE) for SSBs not on the synchronisation raster (e.g., NCD-SSBs), an SSB periodicity for the NCD-SSBs (e.g., in a ssb-Periodicity-r19 IE), a timing offset indication (e.g., in an ssb-TimeOffset-r19 IE), and a transmission power that may be used by the network for transmission of the NCD-SSBs (e.g., in an ncd-ss-Power-r19 IE).

[0144] As shown in Fig. 3, the possible SSB periodicities for the NCD-SSBs which may be indicated by an appropriate IE (e.g., in a ssb-Periodicity-r19 IE, or the like) may also beneficially be adapted / extended to support a greater number of periodicities than those supported by, for example, the ssb-Periodicity-r17 IE described above. For example, the appropriate IE (e.g., ssb-Periodicity-r19 IE, or the like) may additionally support NCD-SSB periodicities of 60 ms, 120 ms, and 320 ms, as well as the typical periodicities of 5 ms, 10 ms, 20 ms, 40 ms, 80 ms, and 160 ms.

[0145] Furthermore, as shown in Fig. 3, the possible timing offsets for the NCD-SSBs which may be indicated by an appropriate IE (e.g., ssb-TimeOffset-r19 IE, or the like) may also beneficially be adapted / extended to support a greater number of time offsets than those supported by, for example, the ssb-TimeOffset-r17 IE described above. For example, the appropriate IE (e.g., ssb-TimeOffset-r19 IE, or the like) may additionally support NCD-SSB timing offsets of 25 ms, 30 ms, 50 ms, and 60 ms, as well as the typical periodicities of 5 ms, 10 ms, 15 ms, 20 ms, 40 ms, and 80 ms.

[0146] It will be appreciated that a plurality of different SSB (adaptation) configurations may be configured for an NES cell. One of multiple NCD SSB configurations on a cell may then be activated immediately upon RRC configuration or activated later via a dynamic SSB adaptation indication, such as DCI, as described above. Alternatively, adaptation of NCD SSB transmission on a cell may be activated via an update of NCD SSB configuration specific parameters such as periodicity, power level, time offset.

[0147] <Activation / deactivation use of adapted SSB configuration for NCD-SSBs> 　　Fig. 4 illustrates an example procedure for configuring and activating / deactivating a UE 3 to use the adapted SSB configuration for NCD-SSBs described with reference to Fig. 3.

[0148] As shown in Fig. 4, there is provided a UE 3 and a RAN node 5 where the UE 3 is in an RRC CONNECTED mode (state) ( as seen at S402).

[0149] Sometime later at step S404, the UE 3 and RAN node 5 may engage in a procedure during which the RAN node 5 transmits an RRC (re)configuration message (or other RRC message), or the like, to the UE 3. That RRC message may, for example, include appropriate indications (e.g., ncd-SSB-NES-r19 SetupRelease IE, or the like) to configure the UE 3 to use the adapted SSB configuration for NCD-SSBs described with reference to Fig. 3 when transmitted by the RAN node 5 to the UE 3. Additionally, RRC (re)configuration message may be adapted / extended to include an appropriate indication (e.g., additional-NonCellDefining-SSB-ConfigList IE) to configure the UE 3 with a list of SSB configurations for NCD-SSBs.

[0150] At step S406, having transmitted the RRC (re)configuration message to the UE 3, the RAN node 5 may activate NCD-SSB transmissions for a SCell to the UE 3 (mode 1) i.e., the RAN node 5 may activate NCD-SSB transmissions for a SCell to the UE 3 on RRC (re)configuration. Those NCD-SSB transmissions may be transmitted to the UE 3 in accordance with the adapted SSB configuration for NCD-SSBs described with reference to Fig. 3.

[0151] Alternatively (or additionally), at step S408, sometime after RRC (re)configuration, the RAN node 5 may activate (or deactivate) NCD-SSB transmissions for a SCell to the UE 3 and may send an appropriate indication (e.g., an SSB adaptation indication, or the like) to the UE 3 to indicate that the RAN node 5 has activated NCD-SSB transmissions for a SCell (mode 2).

[0152] In one example, as indicated at step S408-1, the RAN node 5 may send a UE-specific DCI or a group-common DCI to the UE 3 to provide an SSB adaptation indication to the UE 3 to indicate that the RAN node 5 has activated NCD-SSB transmissions for a SCell (mode 2). For example, the RAN node 5 may be able to send a group-common DCI (e.g., using DCI format 2_9 with CRC scrambled by CellDTRX-RNTI, or a DCI format 2_7 with new RNTI) or UE-specific DCI (e.g., using a DCI Format 1_0 with CRC scrambled by C-RNTI) to indicate that the RAN node 5 has activated NCD-SSB transmissions for a SCell.

[0153] Those DCIs (UE-specific and group-common) may include, for example, a 1-bit indication to indicate that the RAN node 5 has activated (or deactivate) NCD SSB transmissions. Alternatively, those DCIs (UE-specific and group-common) may include a 2-bit indication to indicate that the RAN node 5 has activated (or deactivate) NCD SSB transmissions and / or CD-SSB transmissions. In either scenario, those NCD-SSB transmissions may be transmitted to the UE 3 in accordance with the adapted SSB configuration for NCD-SSBs described with reference to Fig. 3.

[0154] In another example, as indicated at step S408-2, the RAN node 5 may send an SSB adaptation indication to the UE 3 via a MAC control element (CE) to indicate to the UE 3 that the RAN node 5 has activated the transmission of NCD-SSBs for a SCell to the UE 3. That MAC CE used for the transmission of the SSB adaptation indication may, for example, be sent to the UE 3 along with (i.e., at the same time as and / or in the same MAC CE as) an appropriate SCell activation / deactivation indication to indicate to the UE 3 that the RAN node 5 has activated (or is about to activate) a SCell. Alternatively (or additionally), the RAN node 5 may be able to send the SSB adaptation indication to a given UE 3 via a MAC CE at MAC CE based signalling timing (e.g., in a case where that given UE 3 has not successfully received a DCI (e.g., a group-common DCI)).

[0155] Where the RAN node 5 sends an an SSB adaptation indication to the UE 3 as described above, different periodicities for the NCD-SSBs, transmission power levels for the NCD-SSBs, and frequency offsets associated with the NCD-SSBs may be updated via the SSB adaptation indication.

[0156] For example, while the periodicity for the NCD-SSBs, transmission power levels for the NCD-SSBs, and frequency offsets associated with the NCD-SSBs may be configured in accordance with the adapted SSB configuration for NCD-SSBs described with reference to Fig. 3, appropriate indications may be included in the SSB adaptation indication to update / change the periodicity for the NCD-SSBs, transmission power levels for the NCD-SSBs, and frequency offsets associated with the NCD-SSBs. In this scenario, the SSB adaptation indication may include, by way of example, an indication of a periodicity for the NCD-SSBs (e.g., in a ssb-Periodicity IE, or the like), an indication of a transmission power for the NCD-SSBs (e.g., in a ssb-PBCH-BlockPower IE, or the like), and optionally an indication of an SSB frequency offset of the NCD-SSBs for the SCell (e.g., in frequencyOffset IE) for SSBs not on the synchronisation raster.

[0157] Additionally, appropriate indications may be included in the SSB adaptation indication to indicate whether the type of SSB that the RAN node 5 will send to the UE 3 is a CD-SSB or an NCD-SSB (e.g., via an ssb-type IE, or the like).

[0158] < SSB Adaptation and DTX / DRX> 　　As indicated above, in the case where the RAN node 5 sends an appropriate indication (e.g., an SSB adaptation indication, or the like) to the UE 3 to indicate that the RAN node 5 has activated NCD-SSB transmissions for a SCell (mode 2), that SSB adaptation indication may additionally include appropriate information for aligning the SSB transmissions with a cell DTX mode where the UE 3 is configured to attempt to receive signals during a particular time period.

[0159] For example, the SSB adaptation indication may include an appropriate pointer (e.g., Identifier) to point to a row of an appropriate (pre)configured configuration table (e.g., configured by RRC) that informs the UE 3 of periodicity / duration patterns that may be configured for SSB transmissions at the RAN node 5 (e.g., for alignment with cell DTX). The appropriate (pre)configured configuration table may, by way of example only, include the following rows.

[0160] < Impact on SSB Measurement Reporting> 　　As explained above, a UE 3 may use an NCD-SSB for RLM, BFD, and RRM, and may perform serving cell measurements (e.g., in support of any of these). Moreover, an NCD-SSB may be used as a QCL source and / or for RO selection. On the other hand, where a UE 3 needs to perform cell (re-)selection or measurements on a neighbor cell, the UE 3 will, conventionally, use a CD-SSB.

[0161] Beneficially, the communication system 1 may support one or more enhanced techniques for configuring CSI reports, and / or one or more enhancements to triggering / activation mechanisms for L1 measurement, based on NCD-SSB.

[0162] <CSI reporting configuration> 　　For example, as seen in Fig. 5 which illustrates an example procedure for configuring CSI reporting, a CSI reporting configuration may be sent to the UE 3, as indicated at S510, which includes NCD-SSB related configuration parameters.

[0163] As indicated at S510-1, the CSI reporting configuration may, for example, comprise a conventional CSI reporting configuration IE (e.g., CSI-ReportConfig IE) that has been adapted to include the NCD-SSB reporting configuration information. Nevertheless, it will be appreciated that, a new dedicated reporting configuration IE may be used specifically for NCD-SSB reporting configuration (e.g., a CSI-ReportConfig-NCD-SSB IE or the like).

[0164] As indicated at S510-2, the NCD-SSB related configuration parameters included with the CSI reporting configuration may, for example, include an SSB Type IE for indicating the type of SSB (CD-SSB, NCD-SSB, or both) to which the configuration parameter relate (e.g., via a two bit indication that may be set to {1,0}, {0,1} or {1,1} or the like). Alternatively (or additionally) the NCD-SSB related configuration parameters included with the CSI reporting configuration may, for example, include one or more SSB configuration identifiers (e.g., a respective SSB configuration identifier for identifying an SSB configuration for each of one or more NCD-SSBs (or one or more subsets of NCD-SSBs)).

[0165] <Measurement report configuration> 　　For the purposes of L1 measurement reporting based on NCD-SSB, the communication system 1 may be configured to support one or more techniques for activating and / or deactivating semi-persistent L1 measurement reporting on a PUCCH for NCD-SSBs.

[0166] In one technique, for example, a conventional MAC CE (e.g., an SP CSI reporting on PUCCH Activation / Deactivation MAC CE) may be adapted to be able to indicate activation / deactivation of SP CSI reporting on PUCCH for NCD-SSB. This may be achieved, for example, by repurposing one of the reserved bits to allow its use to indicate either that the MAC CE applies to SP CSI reporting on PUCCH Activation / Deactivation for NCD-SSB or that the MAC CE does not apply to SP CSI reporting on PUCCH Activation / Deactivation for NCD-SSBs.

[0167] In another technique, for example, a new dedicated MAC CE may be used for activation / deactivation of semi-persistent L1 measurement reporting on PUCCH for NCD-SSBs.

[0168] Moreover, for the purposes of L1 measurement reporting based on NCD-SSBs, the communication system 1 may be configured to support one or more techniques for configuring one or more trigger states for semi-persistent L1 measurement reporting on a PUSCH for one or more NCD-SSBs from one or more SCells.

[0169] In one technique, for example, a conventional trigger state IE (e.g., a CSI-SemiPersistentOnPUSCH-TriggerState IE) could be adapted to include multiple CSI configuration identifiers (e.g., CSI-ReportConfigId IEs), where each CSI configuration identifier is respectively associated with a corresponding NCD-SSB configuration.

[0170] In another technique, for example, a new dedicated trigger state IE for NCD-SSBs may be used (e.g. a CSI-SemiPersistentOnPUSCH-TriggerState-NCD-SSB IE or the like).

[0171] Moreover, for the purposes of L1 measurement reporting based on NCD-SSBs, the communication system 1 may be configured to support one or more techniques for configuring aperiodic L1 measurement reporting on a PUSCH for NCD-SSBs.

[0172] In one technique, for example, a dedicated NCD-SSB related RNTI (e.g., an NCD-SSB-Aperiodic-Reporting-RNTI IE) may be introduced for configuring one or more uplink scheduling DCI formats (e.g., DCI format 0_1 and / or 0_2) for the purpose of triggering aperiodic L1 measurement reporting on PUSCH for NCD-SSBs.

[0173] <Measurement Report Configuration> <L1 measurement reporting based on NCD-SSB (semi-persistent L1 measurement reporting on a PUCCH)> 　　For the purposes of L1 measurement reporting based on NCD-SSB, the communication system 1 may be configured to support one or more techniques for activating and / or deactivating semi-persistent L1 measurement reporting on a PUCCH for NCD-SSBs.

[0174] In one technique, for example, a conventional MAC CE (e.g., an SP CSI reporting on PUCCH Activation / Deactivation MAC CE) may be adapted to be able to indicate activation / deactivation of SP CSI reporting on PUCCH for NCD-SSB. This may be achieved, for example, by repurposing one of the reserved bits to allow its use to indicate either that the MAC CE applies to SP CSI reporting on PUCCH Activation / Deactivation for NCD-SSB or that the MAC CE does not apply to SP CSI reporting on PUCCH Activation / Deactivation for NCD-SSBs.

[0175] In another technique, for example, a new dedicated MAC CE may be used for activation / deactivation of semi-persistent L1 measurement reporting on PUCCH for NCD-SSBs.

[0176] < L1 measurement reporting based on NCD-SSB (semi-persistent L1 measurement reporting on a PUSCH)> 　　Moreover, for the purposes of L1 measurement reporting based on NCD-SSBs, the communication system 1 may be configured to support one or more techniques for configuring one or more trigger states for semi-persistent L1 measurement reporting on a PUSCH for one or more NCD-SSBs from one or more SCells.

[0177] In one technique, for example, a conventional trigger state IE (e.g., a CSI-SemiPersistentOnPUSCH-TriggerState IE) could be adapted to include multiple CSI configuration identifiers (e.g., CSI-ReportConfigId IEs), where each CSI configuration identifier is respectively associated with a corresponding NCD-SSB configuration.

[0178] In another technique, for example, a new dedicated trigger state IE for NCD-SSBs may be used (e.g. a CSI-SemiPersistentOnPUSCH-TriggerState-NCD-SSB IE or the like).

[0179] <L1 measurement reporting based on NCD-SSB (aperiodic L1 measurement reporting on a PUSCH)> 　　Moreover, for the purposes of L1 measurement reporting based on NCD-SSBs, the communication system 1 may be configured to support one or more techniques for configuring aperiodic L1 measurement reporting on a PUSCH for NCD-SSBs.

[0180] In one technique, for example, a dedicated NCD-SSB related RNTI (e.g., an NCD-SSB-Aperiodic-Reporting-RNTI) may be introduced for configuring one or more uplink scheduling DCI formats (e.g., DCI format 0_1 and / or 0_2) for the purpose of triggering aperiodic L1 measurement reporting on PUSCH for NCD-SSBs.

[0181] < L1 measurement reporting based on NCD-SSB (cell supporting NCD-SSB in which CD-SSBs are periodically transmitted)> 　　In the context of cell supporting NCD-SSB in which CD-SSBs are periodically transmitted, the communication system 1 may be configured to support one or more techniques for configuring the UE 3 to perform L1 / L3 measurements.

[0182] In one technique, for example, a CSI report configuration may be associated with both NCD-SSBs and CD-SSBs. In this case, if NCD-SSB transmission is indicated, a UE 3 may perform L1 measurement based on both CD-SSBs and NCD-SSBs. Otherwise, the UE 3 performs L1 measurement based on the CD-SSBs. Alternatively, if NCD-SSB transmission is indicated, a UE 3 may perform L1 measurement based on NCD-SSBs. Otherwise, the UE 3 performs L1 measurement based on the CD-SSBs.

[0183] In another technique, for example, a given CSI report configuration may be associated with NCD-SSBs or CD-SSBs, but not both.

[0184] <SSB Configuration Adaptations for UE in RRC INACTIVE / IDLE> 　　Fig. 6 illustrates an example procedure for providing an SSB configuration indication to the UE 3 while it is in RRC INACTIVE / IDLE state (mode) to indicate (or point to) an SSB configuration for use by the UE 3 in receiving NCD-SSBs from the RAN node 5.

[0185] As shown in Fig. 6, there is provided a UE 3 and a RAN node 5 that is in RRC IDLE / INACTIVE mode (state) at step S602. That UE 3 is camped on a serving cell (e.g., PCell) of the RAN node 5.

[0186] In one example (option 1 - step S604), the RAN node 5 may provide an NCD-SSB configuration indication to the UE 3 to indicate (or point to) an SSB configuration for use by the UE 3 in receiving NCD-SSBs from the RAN node 5 via a DCI (step S604-1). For example, the RAN node 5 may, at step S604-1, send a UE-specific (or dedicated) DCI to the UE 3 (e.g., a DCI Format 1_0) to indicate (or point to) an SSB configuration for use by the UE 3 in receiving NCD-SSBs from the RAN node 5 via a DCI. In another example, the RAN node 5 may, at step S604-1, send a group-common DCI to the UE 3 (e.g., a DCI Format 2_7 with new RNTI) to indicate (or point to) an SSB configuration for use by the UE 3 in receiving NCD-SSBs from the RAN node 5 via a DCI.

[0187] In an alternative example (option 2 - step S606) the RAN node 5 may provide an NCD-SSB configuration indication to the UE 3 to indicate (or point to) an SSB configuration for use by the UE 3 in receiving NCD-SSBs from the RAN node 5 via a system information (step S606-1). For example, the RAN node 5 may provide an NCD-SSB configuration indication to the UE 3 to indicate (or point to) an SSB configuration for use by the UE 3 in receiving NCD-SSBs from the RAN node 5 in a SIB (e.g., SIBx).

[0188] <Devices in the Communication System> <User Equipment> 　　Fig. 7 is a simplified block schematic illustrating the main components of a UE 3 for implementation in the communication system 1. It will be appreciated that the UE 3 may be configured to operate as an intermediate / assisting node 5-2 (i.e., as an A-IoT device reader) in the communication system 1.

[0189] As shown, the UE 3 has a transceiver circuit 31 that is operable to transmit signals to and to receive signals from a base station 5-1 via one or more antenna 33 (e.g., comprising one or more antenna elements). The UE 3 has a controller 37 to control the operation of the UE 3. The controller 37 is associated with a memory 39 and is coupled to the transceiver circuit 31. Although not necessarily required for its operation, the UE 3 might, of course, have all the usual functionality of a conventional UE 3 (e.g., a user interface 35, such as a touch screen / keypad / microphone / speaker and / or the like for, allowing direct control by and interaction with a user) and this may be provided by any one or any combination of hardware, software, and firmware, as appropriate. Software may be pre-installed in the memory 39 and / or may be downloaded via the communication system or from a removable data storage device (RMD), for example.

[0190] The controller 37 is configured to control overall operation of the UE 3 by, in this example, program instructions or software instructions stored within memory 39. As shown, these software instructions include, among other things, an operating system 41, and a communication control module 43.

[0191] The communication control module 43 is operable to control the communication between the UE 3 and its serving RAN node or RAN nodes 5-1 (and other communication devices connected to the RAN node 5-1, such as further UEs and / or core network nodes). The communication control module 43 is configured for the overall handling of uplink communication via associated uplink channels (e.g., via a physical uplink control channel (PUCCH), random access channel (RACH), and / or a physical uplink shared channel (PUSCH)) including both dynamic and semi-static signalling (e.g., SRS). The communication control module 43 is also configured for the overall handling of receipt of downlink communication via associated downlink channels (e.g., of DCI via a physical downlink control channel (PDCCH) and / or a physical downlink shared channel (PDSCH)) including both dynamic and semi-persistent scheduling (e.g., SPS). The communication control module 43 is responsible, for example: for determining where to monitor for downlink control information; for determining the resources to be used by the UE 3 for transmission / reception of UL / DL communication (including interleaved resources and resources subject to frequency hopping); for managing frequency hopping at the UE side; for determining how slots / symbols are configured (e.g., for UL, DL or full duplex communication, or the like); for determining which bandwidth parts are configured for the UE 3; for determining how uplink transmissions should be encoded and the like.

[0192] Where the UE 3 is configured to operate as an intermediate / assisting node 5-2 (i.e., as an A-IoT device reader), the communication control module 43 may be operable to control the communication between the IoT device 3-1 and the UE 3-2, 3-3, for example, via the associated physical channels (e.g., via a physical D2R (device to reader) channel (PDRCH), random access channel (RACH), and / or a physical R2D (reader to device) channel (PRDCH)).

[0193] It will be appreciated that the communication control module 43 may include a number of sub-modules ('layers' or 'entities') to support specific functionalities. For example, the UE 3 may include sub-modules corresponding to the layers of a conventional protocol stack (PHY, MAC, RRC, RLC, PDCP etc.). Moreover, where the UE 3 is configured to operate as an intermediate / assisting node 5-2, communication control module 43 may include sub-modules corresponding to the layers of a dedicated ambient IoT device protocol stack for controlling functions associated with those layers.

[0194] The communication control module 43 is configured, in particular, to control the UE's communication, where applicable, in accordance with any of the methods described herein.

[0195] <RAN node> 　　Fig. 8 is a simplified block schematic illustrating the main components of a RAN node 5-1 (e.g., a base station / IoT reader device) for implementation in the system of Fig. 1. It will be appreciated that the RAN node 5-1 may be configured to operate as an A-IoT device reader in the communication system 1.

[0196] As shown, the RAN node 5-1 has a transceiver circuit 51 for transmitting signals to and for receiving signals from the communication devices (such as UEs 3-2; 3-3, IoT devices 3-1, and possibly intermediate / assisting nodes 5-2) via one or more antenna 53 (e.g., a single or multi-panel antenna array / massive antenna), and a core network interface 55 for transmitting signals to and for receiving signals from network nodes in the core network 7. Although not shown, the RAN node 5-1 may also be coupled to other base stations via an appropriate interface (e.g., the so-called 'X2' interface in LTE or the 'Xn' interface in NR). The RAN node 5-1 has a controller 57 to control the operation of the base station 5-1. The controller 57 is associated with a memory 59. Software may be pre-installed in the memory 59 and / or may be downloaded via the communication system 1 or from a removable data storage device (RMD), for example. The controller 57 is configured to control the overall operation of the RAN node 5-1 by, in this example, program instructions or software instructions stored within memory 59.

[0197] As shown, these software instructions include, among other things, an operating system 61, and a communication control module 63.

[0198] The communication control module 63 is operable to control the communication between the RAN node 5-1 and UEs 3 and other network entities (e.g., core network nodes) that communicate with the base station 5. The communication control module 63 is configured for the overall control of the reception and decoding of uplink communication, via associated uplink channels (e.g., via a physical uplink control channel (PUCCH), a random-access channel (RACH), and / or a physical uplink shared channel (PUSCH)) including both dynamic and semi-static signalling (e.g., SRS), and modulated backscattered communication in accordance with ambient IoT (where applicable). The communication control module 63 is also configured for the overall control of the transmission of downlink communication including downlink communication via associated downlink channels (e.g., via a physical downlink control channel (PDCCH) and / or a physical downlink shared channel (PDSCH)) including both dynamic and semi-persistent scheduling (e.g., SPS), and downlink communication of an unmodulated carrier signal in accordance with ambient IoT (where applicable). The communication control module 63 is responsible, for example: for determining where to configure the UE 3 to monitor for downlink control information (e.g., the location of search spaces, CORESETs, and associated PDCCH candidates to monitor); for determining the resources to be scheduled for UE transmission / reception of UL / DL communication (including interleaved resources and resources subject to frequency hopping); for managing frequency hopping at the base station side; for configuring slots / symbols appropriately (e.g., for UL, DL or full duplex communication, or the like); for configuring bandwidth parts for the UE 3; for providing related configuration signalling to a UE 3; and the like.

[0199] Where the RAN node 5-1 is configured to operate as an A-IoT device reader the communication control module 63 is operable to control the communication between the IoT device 3-1 and the RAN node 5-1, for example, via the associated physical channels (e.g., via a physical D2R channel (PDRCH), random access channel (RACH), and / or a physical R2D channel (PRDCH)) including both dynamic and semi-static signalling.

[0200] It will be appreciated that the communication control module 63 may include a number of sub-modules ('layers' or 'entities') to support specific functionalities. By way of example only the communication control module 63 may include sub-modules corresponding to the layers of a conventional protocol stack (PHY, MAC, RRC, RLC, PDCP etc.). Moreover, where the RAN node 5-1 is configured to operate as an A-IoT device reader, the communication control module 63 may include, sub-modules corresponding to the layers of a dedicated ambient IoT device protocol stack for controlling functions associated with those layers.

[0201] The communication control module 63 is configured in particular, to control the base station's communication, in accordance with any of the methods described herein.

[0202] <Modifications and Alternatives> 　　Detailed examples been described above. As those skilled in the art will appreciate, a number of modifications and alternatives can be made to the above examples whilst still benefiting from the enhancements embodied therein.

[0203] It will be appreciated that description of features of and actions performed by a RAN node (base station), apply equally to distributed type base stations as to non-distributed type base stations.

[0204] It will also be appreciated that whilst information elements having specific names have been described differently named information elements but having a similar purpose may be used.

[0205] In the above description the UE and the base station are described for ease of understanding as having a number of discrete functional components or modules. Whilst these modules may be provided in this way for certain applications, for example where an existing system has been modified to implement the disclosed enhancements, in other applications, for example in systems designed with the inventive features in mind from the outset, these modules may be built into the overall operating system or code and so these modules may not be discernible as discrete entities.

[0206] In the above examples, a number of software modules were described. As those skilled in the art will appreciate, the software modules may be provided in compiled or un-compiled form and may be supplied to the UE or base station as a signal over a computer network, or on a recording medium. Further, the functionality performed by part, or all, of this software may be performed using one or more dedicated hardware circuits. However, the use of software modules is preferred as it facilitates the updating of the UE or the base station in order to update their functionalities.

[0207] Each controller may comprise any suitable form of processing circuitry including (but not limited to), for example: one or more hardware implemented computer processors; microprocessors; central processing units (CPUs); arithmetic logic units (ALUs); input / output (IO) circuits; internal memories / caches (program and / or data); processing registers; communication buses (e.g. control, data and / or address buses); direct memory access (DMA) functions; hardware or software implemented counters, pointers and / or timers; and / or the like. Various other modifications will be apparent to those skilled in the art and will not be described in further detail here.

[0208] The User Equipment (or "UE," "mobile station," "mobile device" or "wireless device") in the present disclosure is an entity connected to a network via a wireless interface.

[0209] It should be noted that the present disclosure is not limited to a dedicated communication device and can be applied to any device having a communication function as explained in the following paragraphs.

[0210] The terms "User Equipment" or "UE" (as the term is used by 3GPP), "mobile station", "mobile device", and "wireless device" are generally intended to be synonymous with one another, and include standalone mobile stations, such as terminals, cell phones, smart phones, tablets, cellular IoT devices, IoT devices, and machinery. It will be appreciated that the terms "mobile station" and "mobile device" also encompass devices that remain stationary for an extended period of time.

[0211] A UE may, for example, be an item of equipment for production or manufacture and / or an item of energy related machinery (for example equipment or machinery such as: boilers; engines; turbines; solar panels; wind turbines; hydroelectric generators; thermal power generators; nuclear electricity generators; batteries; nuclear systems and / or associated equipment; heavy electrical machinery; pumps including vacuum pumps; compressors; fans; blowers; oil hydraulic equipment; pneumatic equipment; metal working machinery; manipulators; robots and / or their application systems; tools; moulds or dies; rolls; conveying equipment; elevating equipment; materials handling equipment; textile machinery; sewing machines; printing and / or related machinery; paper converting machinery; chemical machinery; mining and / or construction machinery and / or related equipment; machinery and / or implements for agriculture, forestry and / or fisheries; safety and / or environment preservation equipment; tractors; precision bearings; chains; gears; power transmission equipment; lubricating equipment; valves; pipe fittings; and / or application systems for any of the previously mentioned equipment or machinery etc.).

[0212] A UE may, for example, be an item of transport equipment (for example transport equipment such as: rolling stocks; motor vehicles; motorcycles; bicycles; trains; buses; carts; rickshaws; ships and other watercraft; aircraft; rockets; satellites; drones; balloons etc.).

[0213] A UE may, for example, be an item of information and communication equipment (for example information and communication equipment such as: electronic computer and related equipment; communication and related equipment; electronic components etc.).

[0214] A UE may, for example, be a refrigerating machine, a refrigerating machine applied product, an item of trade and / or service industry equipment, a vending machine, an automatic service machine, an office machine or equipment, a consumer electronic and electronic appliance (for example a consumer electronic appliance such as: audio equipment; video equipment; a loud speaker; a radio; a television; a microwave oven; a rice cooker; a coffee machine; a dishwasher; a washing machine; a dryer; an electronic fan or related appliance; a cleaner etc.).

[0215] A UE may, for example, be an electrical application system or equipment (for example an electrical application system or equipment such as: an x-ray system; a particle accelerator; radio isotope equipment; sonic equipment; electromagnetic application equipment; electronic power application equipment etc.).

[0216] A UE may, for example, be an electronic lamp, a luminaire, a measuring instrument, an analyser, a tester, or a surveying or sensing instrument (for example a surveying or sensing instrument such as: a smoke alarm; a human alarm sensor; a motion sensor; a wireless tag etc.), a watch or clock, a laboratory instrument, optical apparatus, medical equipment and / or system, a weapon, an item of cutlery, a hand tool, or the like.

[0217] A UE may, for example, be a wireless-equipped personal digital assistant or related equipment (such as a wireless card or module designed for attachment to or for insertion into another electronic device (for example a personal computer, electrical measuring machine)).

[0218] A UE may be a device or a part of a system that provides applications, services, and solutions described below, as to "internet of things (IoT)," using a variety of wired and / or wireless communication technologies.

[0219] Internet of Things devices (or "things") may be equipped with appropriate electronics, software, sensors, network connectivity, and / or the like, which enable these devices to collect and exchange data with each other and with other communication devices. IoT devices may comprise automated equipment that follow software instructions stored in an internal memory. IoT devices may operate without requiring human supervision or interaction. IoT devices might also remain stationary and / or inactive for an extended period of time. IoT devices may be implemented as a part of a (generally) stationary apparatus. IoT devices may also be embedded in non-stationary apparatus (e.g., vehicles) or attached to animals or persons to be monitored / tracked.

[0220] It will be appreciated that IoT technology can be implemented on any communication devices that can connect to a communication system for sending / receiving data, regardless of whether such communication devices are controlled by human input or software instructions stored in memory.

[0221] It will be appreciated that IoT devices are sometimes also referred to as Machine-Type Communication (MTC) devices or Machine-to-Machine (M2M) communication devices. It will be appreciated that a UE may support one or more IoT or MTC applications. Some examples of MTC applications are listed in the following table. This list is not exhaustive and is intended to be indicative of some examples of machine type communication applications.

[0222] Further, the above-described UE categories are merely examples of applications of the technical ideas and exemplary examples described in the present document. Needless to say, these technical ideas and examples are not limited to the above-described UE and various modifications can be made thereto.

[0223] Various other modifications will be apparent to those skilled in the art and will not be described in further detail here.

[0224] For example, the whole or part of the exemplary embodiments disclosed above can be described as, but not limited to, the following supplementary notes. 　　(Supplementary note 1) 　　A method performed by a User Equipment, UE, the method comprising: receiving, from a network node, first information indicating N periodicities for a Synchronization Signal Block, SSB, for a cell, wherein N is larger than one; and receiving the SSB from the network node. 　　(Supplementary note 2) 　　The method of supplementary note 1, wherein the SSB is a Non-Cell-Defining, NCD, SSB. 　　(Supplementary note 3) 　　The method of supplementary note 1 or 2, further comprising: receiving from the network device, UE-specific Downlink Control Information, DCI, group-common DCI, or a Media Access Control, MAC, Control Element, CE, for switching a periodicity from among the N periodicities, or transmission power levels for the SSBs, or frequency offsets associated with the SSBs. 　　(Supplementary note 4) 　　The method of supplementary note 3, wherein the UE-specific DCI, the group-common DCI, or the MAC CE is an indication for adaptation of a periodicity from among the N periodicities. 　　(Supplementary note 5) 　　The method of supplementary note 3 or 4, wherein the UE-specific DCI or the group-common DCI includes a 1-bit indication to indicate that the network node has either activated or deactivated transmission of the SSB. 　　(Supplementary note 6) 　　The method of supplementary note 2, further comprising: receiving from the network device, UE-specific DCI or group-common Downlink Control Information, DCI, for switching a periodicity from among the N periodicities, transmission power levels for the SSBs, or frequency offsets associated with the SSBs, wherein the UE-specific DCI or the group-common DCI includes a 2-bit indication to indicate that the network node has either activated or deactivated transmission of the NCD SSB or transmission of a Cell-Defining, CD, SSB. 　　(Supplementary note 7) 　　The method of any one of supplementary notes 1-6, wherein the N periodicities are in time domain. 　　(Supplementary note 8) 　　The method of any one of supplementary notes 1-7, wherein the first information further indicates a timing offset for the SSB. 　　(Supplementary note 9) 　　The method of any one of supplementary notes 1-8, wherein the first information further indicates frequency information for the SSB. 　　(Supplementary note 10) 　　The method of any one of supplementary notes 1-9, further comprising: receiving, from the network node, second information indicating configuration for a Cell-Defining, CD, SSB. 　　(Supplementary note 11) 　　The method of any one of supplementary notes 1-10, further comprising: receiving, from the network node, third information configuring the UE to use a configuration indicated by the first information. 　　(Supplementary note 12) 　　The method of any one of supplementary notes 1-11, further comprising: receiving, from the network node, fourth information configuring the UE with a list of configurations of the SSB. 　　(Supplementary note 13) 　　A method performed by a network node, the method comprising: transmitting, to User Equipment, UE, first information indicating N periodicities for a Synchronization Signal Block, SSB, for a cell, wherein N is larger than one; and transmitting the SSB to the UE. 　　(Supplementary note 14) 　　The method of supplementary note 13, wherein the SSB is a Non-Cell-Defining, NCD, SSB. 　　(Supplementary note 15) 　　The method of supplementary note 13 or 14, further comprising: transmitting to the UE, UE-specific Downlink Control Information, DCI, group-common DCI, or a Media Access Control, MAC, Control Element, CE, for switching a periodicity from among the N periodicities, or transmission power levels for the SSBs, or frequency offsets associated with the SSBs. 　　(Supplementary note 16) 　　The method of supplementary note 15, wherein the UE-specific DCI, the group-common DCI, or the MAC CE is an indication for adaptation of a periodicity from among the N periodicities. 　　(Supplementary note 17) 　　The method of supplementary note 15 or 16, wherein the UE-specific DCI or the group-common DCI includes a 1-bit indication to indicate that the network node has either activated or deactivated transmission of the SSB. 　　(Supplementary note 18) 　　The method of supplementary note 14, further comprising: transmitting to the UE, UE-specific DCI or group-common Downlink Control Information, DCI, for switching a periodicity from among the N periodicities, transmission power levels for the SSBs, or frequency offsets associated with the SSBs, wherein the UE-specific DCI or the group-common DCI includes a 2-bit indication to indicate that the network node has either activated or deactivated transmission of the NCD SSB or transmission of a Cell-Defining, CD, SSB. 　　(Supplementary note 19) 　　The method of any one of supplementary notes 13-18, wherein the N periodicities are in time domain. 　　(Supplementary note 20) 　　The method of any one of supplementary notes 13-19, wherein the first information further indicates a timing offset for the SSB. 　　(Supplementary note 21) 　　The method of any one of supplementary notes 13-20, wherein the first information further indicates frequency information for the SSB. 　　(Supplementary note 22) 　　The method of any one of supplementary notes 13-21, further comprising: transmitting, to the UE, second information indicating configuration for a Cell-Defining, CD, SSB. 　　(Supplementary note 23) 　　The method of any one of supplementary notes 13-22, further comprising: transmitting, to the UE, third information configuring the UE to use a configuration indicated by the first information. 　　(Supplementary note 24) 　　The method of any one of supplementary notes 13-23, further comprising: transmitting, to the UE, fourth information configuring the UE with a list of configurations of the SSB. 　　(Supplementary note 25) 　　A User Equipment, UE, comprising: means for receiving, from a network node, first information indicating N periodicities for a Synchronization Signal Block, SSB, for a cell, wherein N is larger than one; and means for receiving the SSB from the network node. 　　(Supplementary note 26) 　　A network node comprising: means for transmitting, to User Equipment, UE, first information indicating N periodicities for a Synchronization Signal Block, SSB, for a cell, wherein N is larger than one; and means for transmitting the SSB to the UE.

[0225] This application is based upon and claims the benefit of priority from Great Britain Patent Application No. 2416509.4, filed on November 8, 2024, the disclosure of which is incorporated herein in its entirety by reference.

[0226] 1 COMMUNICATION SYSTEM 3 USER EQUIPMENT 5 RAN NODE 7 CORE NETWORK 10 CONTROL PLANE FUNCTIONS 11 USER PLANE FUNCTIONS 20 EXTERNAL DATA NETWORK 31 TRANSCEIVER CIRCUIT 33 ANTENNA 35 USER INTERFACE 37 CONTROLLER 39 MEMORY 41 OPERATING SYSTEM 43 COMMUNICATIONS CONTROL MODULE 51 TRANSCEIVER CIRCUIT 53 ANTENNA 55 CORE NETWORK INTERFACE 57 CONTROLLER 59 MEMORY 61 OPERATING SYSTEM 63 COMMUNICATIONS CONTROL MODULE

Claims

1. A method performed by a User Equipment, UE, the method comprising: receiving, from a network node, first information indicating N periodicities for a Synchronization Signal Block, SSB, for a cell, wherein N is larger than one; and receiving the SSB from the network node.

2. The method of claim 1, wherein the SSB is a Non-Cell-Defining, NCD, SSB.

3. The method of claim 1 or 2, further comprising: receiving from the network device, UE-specific Downlink Control Information, DCI, group-common DCI, or a Media Access Control, MAC, Control Element, CE, for switching a periodicity from among the N periodicities, or transmission power levels for the SSBs, or frequency offsets associated with the SSBs.

4. The method of claim 3, wherein the UE-specific DCI, the group-common DCI, or the MAC CE is an indication for adaptation of a periodicity from among the N periodicities.

5. The method of claim 3 or 4, wherein the UE-specific DCI or the group-common DCI includes a 1-bit indication to indicate that the network node has either activated or deactivated transmission of the SSB.

6. The method of claim 2, further comprising: receiving from the network device, UE-specific DCI or group-common Downlink Control Information, DCI, for switching a periodicity from among the N periodicities, transmission power levels for the SSBs, or frequency offsets associated with the SSBs, wherein the UE-specific DCI or the group-common DCI includes a 2-bit indication to indicate that the network node has either activated or deactivated transmission of the NCD SSB or transmission of a Cell-Defining, CD, SSB.

7. The method of any one of claims 1-6, wherein the N periodicities are in time domain.

8. The method of any one of claims 1-7, wherein the first information further indicates a timing offset for the SSB.

9. The method of any one of claims 1-8, wherein the first information further indicates frequency information for the SSB.

10. The method of any one of claims 1-9, further comprising: receiving, from the network node, second information indicating configuration for a Cell-Defining, CD, SSB.

11. The method of any one of claims 1-10, further comprising: receiving, from the network node, third information configuring the UE to use a configuration indicated by the first information.

12. The method of any one of claims 1-11, further comprising: receiving, from the network node, fourth information configuring the UE with a list of configurations of the SSB.

13. A method performed by a network node, the method comprising: transmitting, to User Equipment, UE, first information indicating N periodicities for a Synchronization Signal Block, SSB, for a cell, wherein N is larger than one; and transmitting the SSB to the UE.

14. The method of claim 13, wherein the SSB is a Non-Cell-Defining, NCD, SSB.

15. The method of claim 13 or 14, further comprising: transmitting to the UE, UE-specific Downlink Control Information, DCI, group-common DCI, or a Media Access Control, MAC, Control Element, CE, for switching a periodicity from among the N periodicities, or transmission power levels for the SSBs, or frequency offsets associated with the SSBs.

16. The method of claim 15, wherein the UE-specific DCI, the group-common DCI, or the MAC CE is an indication for adaptation of a periodicity from among the N periodicities.

17. The method of claim 15 or 16, wherein the UE-specific DCI or the group-common DCI includes a 1-bit indication to indicate that the network node has either activated or deactivated transmission of the SSB.

18. The method of claim 14, further comprising: transmitting to the UE, UE-specific DCI or group-common Downlink Control Information, DCI, for switching a periodicity from among the N periodicities, transmission power levels for the SSBs, or frequency offsets associated with the SSBs, wherein the UE-specific DCI or the group-common DCI includes a 2-bit indication to indicate that the network node has either activated or deactivated transmission of the NCD SSB or transmission of a Cell-Defining, CD, SSB.

19. The method of any one of claims 13-18, wherein the N periodicities are in time domain.

20. The method of any one of claims 13-19, wherein the first information further indicates a timing offset for the SSB.

21. The method of any one of claims 13-20, wherein the first information further indicates frequency information for the SSB.

22. The method of any one of claims 13-21, further comprising: transmitting, to the UE, second information indicating configuration for a Cell-Defining, CD, SSB.

23. The method of any one of claims 13-22, further comprising: transmitting, to the UE, third information configuring the UE to use a configuration indicated by the first information.

24. The method of any one of claims 13-23, further comprising: transmitting, to the UE, fourth information configuring the UE with a list of configurations of the SSB.

25. A User Equipment, UE, comprising: means for receiving, from a network node, first information indicating N periodicities for a Synchronization Signal Block, SSB, for a cell, wherein N is larger than one; and means for receiving the SSB from the network node.

26. A network node comprising: means for transmitting, to User Equipment, UE, first information indicating N periodicities for a Synchronization Signal Block, SSB, for a cell, wherein N is larger than one; and means for transmitting the SSB to the UE.

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