Synchronization signal measurement technique

Abstract

The technique comprises a method aspect performed by a radio device (100; 1000; 1291; 1292) in communication with a radio access network, RAN (500). The method (300) comprises receiving (304), from a network node (200; 1100; 1212) of the RAN (500), a control message that is indicative of measuring at least one of always-on synchronization signal blocks, AO-SSB (901), on an AO-SSB frequency resource (911) and on-demand synchronization signal blocks, OD-SSB (902), on an OD-SSB frequency resource (912). The method (300) further comprises measuring (306) on at least one of the AO-SSB frequency resource (911) and the OD- SSB frequency resource (912) in response to the received (304) control message.

Description

[0001] SYNCHRONIZATION SIGNAL MEASUREMENT TECHNIQUE

[0002] Technical Field

[0003] The present disclosure relates to a technique for synchronization signal measurement in a wireless network. More specifically, and without limitation, methods and devices for measuring synchronization signal blocks are provided.

[0004] Background

[0005] The telecommunications industry, particularly under the coordination of the Third Generation Partnership Project (3GPP), is continuously evolving radio access technologies. These developments often intersect with frameworks such as the O-RAN Alliance to ensure openness and interoperability across different vendor solutions. As networks become more advanced, synchronization signal blocks are used to facilitate efficient network performance under varying network conditions.

[0006] Vendors and operators have sought mechanisms to manage synchronization signals in ways that meet both performance and efficiency requirements. In such efforts, measurement procedures for synchronization signals have played a significant role, influencing how radio devices and network nodes coordinate resource usage.

[0007] However, existing approaches often face limitations in adaptively handling synchronization signals, especially in scenarios involving different types of transmission resources. This can lead to suboptimal performance and increased complexity when trying to balance flexibility with transmission overhead.

[0008] Summary

[0009] Accordingly, there is a need for a measurement technique that enables efficient and flexible measurements of synchronization signals.

[0010] According to a first method aspect, a method performed by a radio device in communication with a radio access network is provided. The method comprises receiving from a network node a control message that is indicative of measuring at least one of always-on synchronization signal blocks (AO-SSB) on an always-on frequency resource (AO-SSB frequency resource) and on-demand synchronizationsignal blocks (OD-SSB) on an on-demand frequency resource (OD-SSB frequency resource). The method further comprises measuring, in response to the received control message, on at least one of the always-on frequency resource and the on-demand frequency resource.

[0011] By performing these steps, method embodiments enable the radio device to dynamically adapt its measurement processes based on instructions from the network node. This allows a controlled and efficient usage of frequency resources, avoids futile rigid synchronization monitoring, and leads to improved network adaptability without imposing unnecessary overhead on the radio device.

[0012] The first method aspect may be implemented alone or in combination with any one of the embodiments in the below embodiments.

[0013] According to a second method aspect, a method performed by a network node in a radio access network is provided. The method comprises transmitting to a radio device a control message that is indicative of measuring at least one of always-on synchronization signal blocks (AO-SSB) on an always-on frequency resource (AO-SSB frequency resource) and on-demand synchronization signal blocks (OD-SSB) on an on-demand frequency resource (DO-SSB frequency resource). The method further comprises receiving from the radio device a measurement report that is indicative of results of measuring on at least one of the always-on frequency resource and the on-demand frequency resource.

[0014] Through these steps, method embodiments enable the network node to flexibly instruct the radio device to measure certain frequency resources and then appropriately obtain corresponding measurement information. As a result, the network node resolves the technical problem of coordinating synchronization signal measurements, ensuring that resources are used efficiently and that measurement procedures can be adapted to changing network conditions.

[0015] The second method aspect may be implemented alone or in combination with any one of the below embodiments, particularly network-side embodiments corresponding mutatis mutandis to the radio device-side embodiments.

[0016] The second method aspect may further comprise any feature and / or any step disclosed in the context of the first method aspect, or a feature and / or stepcorresponding thereto, e.g., a receiver counterpart to a transmitter feature or step.

[0017] The technique may be applied in the context of 3GPP New Radio (NR), NR Advanced, and beyond fifth generation (5G) radio access technology.

[0018] The technique may be implemented in accordance with a 3GPP specification, e.g., for 3GPP release 19 or beyond. The technique may be implemented for 3GPP NR according to a modification of the 3GPP document TS 38.331 (e.g., version 18.5.1 or later), particularly clauses 5.5.2.9 (Measurement gap configuration), 5.5.2.11 (Measurement gap sharing configuration), 5.5.3.3a (Derivation of layer 3 beam filtered measurement) thereof; and / or 3GPP TS 38.133 (e.g., version 18.8.0), particularly clauses 9. ID (General measurement requirement for ATG), 9.2.4.4 (SCell activation Triggered Reporting), 9.2.7.2 (Tables on intra-frequency measurements), 9.2C.5.1 (Intra-frequency cell identification), 9.10.2.5 (Tables on intra-frequency measurements without gaps); and / or 3GPP TS 38.321 (e.g., version 18.5.0), particularly clauses 5.1 (Random Access procedure), 5.15 (Bandwidth Part (BWP) operation); and / or 3GPP TS 38.213 (e.g., version 18.6.0), particularly clauses 4.1 (Synchronization procedures for Cell search), 5 (Radio link monitoring), 8.1 (Random access preamble, which may be triggered by the first and second method aspects), 10 (UE procedure for receiving control information) and 10.1 (UE procedure for determining physical downlink control channel assignment), which may be modified for the control message.

[0019] In any radio access technology (RAT), the technique may be implemented for SL relay selection. The SL may be implemented using proximity services (ProSe), e.g. according to a 3GPP specification.

[0020] Any radio device may be a user equipment (UE), e.g., according to a 3GPP specification. The radio device and the RAN (e.g., the network node or any further network node serving the radio device) may be wirelessly connected in an uplink (UL) and / or a downlink (DL) through a Uu interface. Alternatively or in addition, a sidelink (SL) may enable a direct radio communication between proximal radio devices, e.g., the remote radio device and the relay radio device, optionally using a PC5 interface. Services provided using the SL or the PC5 interface may be referred to as proximity services (ProSe). Any radio device (e.g., a remote radio device and / or a relay radio device) supporting a SL may be referred to as ProSe-enabledradio device. The relay radio device may also be referred to as ProSe UE-to-Network Relay.

[0021] The radio device and / or the RAN (e.g., the network node or further network nodes) may form, or may be part of, a radio network, e.g., according to the Third Generation Partnership Project (3GPP) or according to the standard family IEEE 802.11 (Wi-Fi). The first method aspect and the second method aspect may be performed by one or more embodiments of the radio device and the relay radio device or the network node (or any other node of the RAN, e.g., including base station functionality), respectively.

[0022] The RAN may comprise one or more network nodes (e.g., base stations) performing the second method aspect. Alternatively or in addition, the radio network may be a vehicular, ad hoc and / or mesh network comprising two or more radio devices, e.g., acting as the radio device (first aspect) and the relay radio device (second aspect).

[0023] Any of the radio devices may be a 3GPP user equipment (UE) or a Wi-Fi station (STA). The radio device may be a mobile or portable station, a device for machinetype communication (MTC), a device for narrowband Internet of Things (NB-IoT) or a combination thereof. Examples for the UE and the mobile station include a mobile phone, a tablet computer and a self-driving vehicle. Examples for the portable station include a laptop computer and a television set. Examples for the MTC device or the NB-IoT device include robots, sensors and / or actuators, e.g., in manufacturing, automotive communication and home automation. The MTC device or the NB-IoT device may be implemented in a manufacturing plant, household appliances and consumer electronics.

[0024] Whenever referring to the RAN, the RAN may be implemented by one or more base stations, which functionality may be split across multiple network node (e.g., a central unit and a distributed unit).

[0025] The radio device may be wirelessly connected or connectable (e.g., according to a radio resource control, RRC, state or active mode) with the network node of the RAN (or the relay radio device of the mesh network). The relay radio device may be wirelessly connected or connectable (e.g., according to a radio resource control, RRC, state or active mode) with at least one base station of the RAN.The network node (e.g., a base station) may encompass any station that is configured to provide radio access to any of the radio devices. The network node may correspond to one or more cells (e.g., serving cells for the radio device), a transmission and reception point (TRP), a central unit (CU), a distributed unit (DU), a radio access node or an access point (AP). The network node (and / or the relay radio device) may provide a data link to a host computer providing user data to the (e.g., remote) radio device or gathering user data from the (e.g., remote) radio device. Examples for the base stations may include a 3G base station or Node B (NB), 4G base station or eNodeB (eNB), a 5G base station or gNodeB (gNB), a Wi-Fi AP and a network controller (e.g., according to Bluetooth, ZigBee or Z-Wave).

[0026] The RAN may be implemented according to the Global System for Mobile Communications (GSM), the Universal Mobile Telecommunications System (UMTS), 3GPP Long Term Evolution (LTE) and / or 3GPP New Radio (NR).

[0027] Any aspect of the technique may be implemented on a Physical Layer (PHY), a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer, a packet data convergence protocol (PDCP) layer, and / or a Radio Resource Control (RRC) layer of a protocol stack for the radio communication.

[0028] Herein, referring to a protocol of a layer may also refer to the corresponding layer in the protocol stack. Vice versa, referring to a layer of the protocol stack may also refer to the corresponding protocol of the layer. Any protocol may be implemented by a corresponding method.

[0029] In other words, as to a first method aspect, a method performed by a radio device in communication with a radio access network (RAN) is provided. The method comprises receiving, from a network node of the RAN, a control message that is indicative of measuring at least one of always-on synchronization signal blocks (AO-SSB) on an AO-SSB frequency resource and on-demand synchronization signal blocks (OD-SSB) on an OD-SSB frequency resource. The method further comprises measuring on at least one of the AO-SSB frequency resource and the OD-SSB frequency resource in response to the received control message.

[0030] Alternatively or additionally, the control message may be indicative of measuring AO-SSB on the AO-SSB frequency resource, and the measuring may be performed on the AO-SSB frequency resource.Alternatively or additionally, the control message may be indicative of measuring OD-SSB on the OD-SSB frequency resource, and the measuring may be performed on the OD-SSB frequency resource.

[0031] Method embodiments can, based on the control message, avoid an interruption of SSB measurements and / or resolve an arbitrariness as to which reference signals (e.g., synchronization signals) the radio device shall monitor. By receiving the control message of the AO-SSB associated with the AO-SSB frequency resource and / or the OD-SSB associated with the OD-SSB frequency resource, and then performing measurements on the indicated frequency, embodiments of the method enable changing the SSB measurement flexible in the frequency domain and / or with reduced transmission of reference signals. Same or further method embodiments support dynamic activation and deactivation of synchronization signals, e.g., reducing energy consumption on the network side and measurement overhead on the device side. This approach can allow the RAN to reduce unnecessary SSB transmissions, thereby reducing power consumption and improving overall efficiency. Alternatively or in addition, method embodiment can enable the radio device to receive SSB and / or system information only when necessary, e.g. optimizing the use of network resources.

[0032] The OD-SSB may refer to synchronization signal bursts that are transmitted by the network node and / or received by the radio device only when necessary or triggered, e.g. rather than continuously or periodically. The OD-SSB frequency resource may be a radio frequency channel and / or a set of contiguous subcarriers on which the network node configures and / or transmits the OD-SSB and / or the radio device measures (e.g., receives) the OD-SSB. Alternatively or in addition, the AO-SSB may refer to a continuous or periodic transmission of SSB.

[0033] The measuring (e.g., a measurement procedure) may encompasses activities such as any one or more of radio signal assessment, synchronization, beam detection, and link quality evaluation, and reception of a master information block (or another system information block).

[0034] In an example RAN, the network node may transmit (e.g., broadcast or unicast) an indication of OD-SSB activation or deactivation as the control message. The radio device may, e.g. upon receiving the indication of the activation of the OD-SSB, measure (e.g., receive) on the OD-SSB frequency resource. This may happen in conjunction with AO-SSB transmissions and / or when OD-SSB is newly activated on a cell, e.g. a secondary cell serving the radio device. Alternatively or in addition,the radio device may, e.g. upon receiving the indication of the deactivation of the OD-SSB, measure (e.g., receive) on the AO-SSB frequency resource.

[0035] Each SSB (e.g. of the AO-SSB and the OD-SSB) may comprise at least one of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). The PBCH may comprise at least one of demodulation reference signals (DM-RS) and PBCH data. The PBCH data may comprise a Master Information Block (MIB).

[0036] The AO-SSB frequency resource and the OD-SSB frequency resource may be different.

[0037] Alternatively or additionally, the AO-SSB frequency resource and the OD-SSB frequency resource may be in the same bandwidth part (BWP), or in-band.

[0038] The AO-SSB frequency resource may be indicative of a center frequency of the AO-SSB. The OD-SSB frequency resource may be indicative of a center frequency of the OD-SSB. The center frequency of the AO-SSB and the center frequency of the OD-SSB may be different. Alternatively or in addition, the AO-SSB and OD-SSB occupy non-overlapping and / or spaced-apart frequency ranges in the frequency domain. For example, the AO-SSB frequency resource may be indicative of a frequency range of the AO-SSB. The OD-SSB frequency resource may be indicative of a frequency range of the OD-SSB. The frequency range of the AO-SSB and the frequency range of the OD-SSB may be distinct, non-overlapping (e.g., disjoint), and / or separated (e.g., non-contiguous).

[0039] The BWP may refer to a carrier bandwidth part of a serving cell of the network node serving the radio device, e.g. a secondary cell (e.g., of a carrier aggregation and / or dual connectivity). Alternatively or in addition, the BWP may be a contiguous set of physical resource blocks (PRB) within the overall channel bandwidth of a serving cell of the network node serving the radio device.

[0040] Alternatively or in addition, the BWP may be configured with specific parameters, e.g. at least one of numerology, subcarrier spacing (SCS), and cyclic prefix length. Alternatively or in addition, the AO-SSB frequency resource and the OD-SSB frequency resource may be in the same active BWP. For example, the BWP may be activated (e.g., by switching to this BWP) using at least one of radio resource control (RRC) signaling; downlink control information (DCI, e.g. using DCI formats 0_l for uplink grant and 1_1 for downlink assignment); and BWP inactivity timer (e.g., a timer-based mechanism where the radio device switches to a default BWP after a specified period of inactivity).Herein, being "in-band" and "in the same BWP" may be synonymous. Alternatively or in addition, "in-band" may mean within the currently active BWP frequency span, e.g. of the radio device.

[0041] In one variant of any embodiment, the AO-SSB frequency resource and the OD-SSB frequency resource may be in-band frequencies, e.g., within one BWP, of a serving cell serving the radio device. In another variant of any embodiment, the AO-SSB frequency resource and the OD-SSB frequency resource may be intra-band or within the same carrier band (e.g., also including frequencies outside of an active BWP) of a serving cell serving the radio device.

[0042] The measuring may be a serving-cell measurement of a serving cell serving the radio device.

[0043] Alternatively or additionally, the AO-SSB may be cell-defining synchronization signal blocks (CD-SSB).

[0044] Alternatively or additionally, the OD-SSB may be non-cell-defining synchronization signals (NCD-SSB).

[0045] The PSS and the SSS of a CD-SSB may carry a physical cell identity (PCI) of a serving cell, provided by the network node and / or serving the radio device.

[0046] The AO-SSB and / or the OD-SSB may be received in the same cell served by the network node.

[0047] Alternatively or additionally, a cell of the AO-SSB and / or the OD-SSB may be a primary cell (PCell), or a secondary cell (SCell), serving the radio device in a carrier aggregation (CA).

[0048] Alternatively or additionally, the network node may be a master node (MN), and a cell of the AO-SSB and / or the OD-SSB may be an SCell of the MN. Alternatively or additionally, the network node may be a secondary node (SN), and a cell of the AO-SSB and / or the OD-SSB may be a primary secondary cell (PSCell), or an SCell of the SN, serving the radio device in a dual connectivity (DC) and / or CA.

[0049] The received control message, optionally a flag comprised in the control message, may be indicative of one of several measurement alternatives.

[0050] For example, the control message, optionally the flag comprised in the control message, may be indicative of whether or not the radio device shall measure the AO-SSB.Alternatively or additionally, the control message, optionally the flag comprised in the control message, may be indicative of whether or not the radio device shall measure the OD-SSB.

[0051] Alternatively or additionally, the control message, optionally the flag comprised in the control message, may be indicative of whether the radio device shall measure either the AO-SSB or the OD-SSB.

[0052] Alternatively or additionally, the control message, optionally the flag comprised in the control message, may be indicative that the radio device shall measure both the AO-SSB and the OD-SSB.

[0053] The method may further comprise receiving, from the network node of the RAN, a configuration message that is indicative of a configuration of the radio device for at least one of the AO-SSB and the OD-SSB.

[0054] Alternatively or additionally, the configuration message may be indicative of a configuration of the radio device for the AO-SSB.

[0055] Alternatively or additionally, the configuration message may be indicative of a configuration of the radio device for the OD-SSB.

[0056] The control message may be (e.g., implied by or included in or identical with) the configuration message indication (e.g., the flag).

[0057] The configuration message may configure the radio device, or the radio device may be configured, to selectively utilize the OD-SSB, e.g. to enhance network energy efficiency when there is minimal or no data transmission. In such scenarios, the network node may cease a transmission of the AO-SSB and instead rely on transmission of the OD-SSB, e.g. according to the control message.

[0058] In a radio protocol stack, a configuration layer for the configuration message (e.g., radio resource control (RRC) layer) may be above a control layer for the control message (e.g., a physical layer (PHY) or a medium access control (MAC) layer). This may enable dynamically activating and / or deactivating the OD-SSB by the control message, e.g. without repeating a configuration of the OD-SSB according to the configuration message.

[0059] The method may comprise triggering (by the radio device) the transmission of the OD-SSB and / or System Information Block 1 (SIB1), e.g., as needed or to fulfill a Quality of Service (QoS) requirement of the radio device. The radio device and / orthe network node may determine the QoS requirement or transmit an indication of the QoS requirement to the network node or the radio device, respectively. Alternatively or in addition, the configuration message may configure the radio device, or the radio device may be configured, with parameters to trigger (e.g., request) the OD-SSB, e.g., to trigger the activation of the OD-SSB and / or the deactivation of the AO-SSB. The configuration message received by the radio device may be indicative of an availability and / or a procedure for OD-SSB transmission (from the network node and / or in a cell serving the radio device). The radio device may, upon accessing the RAN or establishing a secondary carrier (e.g., a secondary cell, e.g., for carrier aggregation or dual connectivity) initiate a request for AO-SSB or OD-SSB, e.g., prompting the network node to transmit the AO-SSB and / or the OD-SSB (e.g. and associated system information) to the radio device. At least one of the configuration message and the control message may be indicative of the OD-SSB frequency resource of the OD-SSB.

[0060] Alternatively or additionally, at least one of the configuration message and the control message may be indicative of the AO-SSB frequency resource of the AO-SSB.

[0061] The network node may indicate which frequency is believed as the intra-frequency for the serving cell.

[0062] For example, the network node may indicate that the OD-SSB frequency is believed as the intra-frequency for the serving cell.

[0063] Alternatively or additionally, the network node may indicate that the AO-SSB frequency is believed as the intra-frequency for the serving cell.

[0064] Alternatively or additionally, the network node may indicate that both frequencies are believed as the intra-frequency for the serving cell.

[0065] Such indication may be explicitly based on network signaling, such as OD-SSB indication, Measurement Objects configuration, or servingCellMO configuration. Upon receiving the control message, the method may further comprise treating the indicated OD-SSB frequency resource as an intra-frequency resource.

[0066] Alternatively or additionally, the measurement on the OD-SSB frequency resource may be an intra-frequency measurement.Alternatively or additionally, the measurement on the OD-SSB frequency resource may be an intra-BWP measurement.

[0067] Alternatively or additionally, the measurement on the OD-SSB frequency resource may require no dedicated measurement gap.

[0068] The radio device may measure on the OD-SSB frequency resource without tuning, and / or without time for changing a carrier frequency, of a radio receiver of the radio device to the OD-SSB frequency resource, e.g. since a carrier bandwidth and / or an active BWP of a serving cell of the network node (e.g., which cell is serving the radio device) covers both the AO-SSB frequency resource and the OD-SSB frequency resource.

[0069] Method embodiments can allow the radio device to carry out the measurement without having to schedule a dedicated gap, thereby facilitating quicker and more power-efficient measurements. Because the radio device treats OD-SSB frequency resource as intra-frequency, the radio device may reuse the serving cell's receiver configuration.

[0070] Herein, intra-frequency resource (or accordingly intra-frequency measurement) may be a frequency domain that is aligned with or subsumed under the radio device's currently active bandwidth part (BWP) or otherwise recognized as same band for measurement, e.g. avoiding the need for measurement gaps.

[0071] In a multi-carrier deployment, the network node may configure OD-SSB (e.g., for a secondary cell or SCell) on the same carrier (e.g., carrier bandwidth) or BWP in which the radio device's primary cell (PCell) is operating. Consequently, the radio device does not need to interrupt data reception or transmission to measure on a separate frequency band.

[0072] The measuring may be a neighbor-cell measurement on the OD-SSB frequency resource.

[0073] Alternatively or additionally, the neighbor-cell measurement on the OD-SSB frequency resource may be an intra-frequency measurement.

[0074] Alternatively or additionally, dedicated measurement gaps may be avoided for the neighbor-cell measurement.By extending the intra-frequency designation to neighbor cells, embodiments of the method can reduce measurement overhead and complexity for multi-cell scenarios, accelerating handover decisions and neighbor evaluation.

[0075] Herein, neighbor-cell measurements may refer to evaluating cell-specific parameters (e.g., reference signal power or quality) for cells other than a serving cell of the radio device.

[0076] For instance, the radio device may need to measure (e.g., receive) the OD-SSB from one or more neighboring cells (on the same frequency resource) to decide if a handover to or addition of a secondary cell is beneficial. Since the radio device treats these measurements as intra-frequency measurements, the radio device can monitor all candidate neighbors without scheduling measurement gaps.

[0077] The method may further comprise reverting to measuring a or the AO-SSB on an or the AO-SSB frequency resource if the received control message is indicative of transmissions of the OD-SSB being deactivated and / or if an on-demand timer at the radio device has expired.

[0078] For example, the AO-SSB may be measured on a default frequency not indicated by the control message.

[0079] Embodiments of the method can ensure continuity of SSB measurements when the OD-SSB is no longer being transmitted by the network node. The radio device may maintain reliable synchronization and / or mobility support by reverting to the AO-SSB measurement.

[0080] The default frequency may be a (e.g., by the network node) previously configured frequency at which AO-SSB is continuously or periodically available.

[0081] For example, if the network node disables OD-SSB to save power, the radio device may seamlessly return to measuring AO-SSB. In a typical scenario, this can avoid a measurement interruption and / or resolve arbitrariness as to which reference signals the radio device shall monitor.

[0082] If the received control message is indicative of a deactivation of the OD-SSB and / or in the absence of an explicit activation of the OD-SSB, the method may further comprise treating an or the AO-SSB frequency resource as primary intra-frequency resource and / or performing the measurement on an or the AO-SSB frequency resource.Alternatively or additionally, the method may further comprise skipping OD-SSB measurements in the measurement unless a specific activation is received in the control message.

[0083] Method embodiments can ensure a stable baseline for serving-cell measurements by using an always-on reference frequency whenever OD-SSB is not actively indicated, thereby guaranteeing continuous signal availability for measurements. According to the primary intra-frequency resource, the radio device may associate a priority or default status with the AO-SSB for performing ongoing measurements unless OD-SSB is explicitly configured.

[0084] In an example RAN deployment, the radio device can rely on AO-SSB for routine measurements and only switch to OD-SSB when the network node signals that OD-SSB is active on the OD-SSB frequency resource as a particular frequency.

[0085] By skipping OD-SSB measurements unless a specific activation is received, embodiments can reduce measurement complexity and / or radio device processing load. Same or further embodiments can prevent the radio device from wasting energy searching for OD-SSB signals when none are present.

[0086] Skipping OD-SSB measurements may mean that the radio device does not configure or attempt to detect on-demand reference signals without a prior indication from the network node. For example, in a RAN that rarely uses OD-SSB, the radio device may remain aligned with the AO-SSB frequency resource and only reconfigures to OD-SSB measurement mode upon explicit instruction.

[0087] When both the AO-SSB frequency resource and the OD-SSB frequency resource are simultaneously configured within the same carrier bandwidth and / or activated for measurement, the method may further comprise performing the measurements for each of the AO-SSB frequency resource and the OD-SSB frequency resource as intra-frequency measurements.

[0088] Alternatively or additionally, both frequency resources may be simultaneously configured within the same carrier bandwidth.

[0089] Alternatively or additionally, both frequency resources may be activated for measurement.

[0090] By measuring both AO-SSB and OD-SSB located in the same active bandwidth of the radio device, such embodiments of the radio device may acquirecomprehensive information on serving-cell quality across multiple possible reference signals, enabling more robust mobility and beam management decisions.

[0091] Herein, the same active and / or carrier bandwidth may refer to frequencies (e.g., subcarriers) belonging to a Fourier window in the frequency domain simultaneously received or receivable by the radio device. When the network node configures the AO-SSB and the OD-SSB in-band, the radio device can unify its measurement timeline to consider both the AO-SSB and the OD-SSB without scheduling (e.g., additional) measurement gaps. This can be beneficial in coveragelimited or capacity-limited scenarios.

[0092] In a high-frequency or frequency range 2 (FR2) deployment of a serving cell of the network node serving the radio device, the method may further comprise applying a quasi co-location (QCL) between the AO-SSB and the OD-SSB in the measuring. For example, the QCL may be applied so as to carry out OD-SSB serving-cell measurements without receive beam sweeping.

[0093] Embodiments of the method can accelerate OD-SSB measurements by exploiting known spatial relationships (e.g., QCL) from the AO-SSB. The QCL (e.g., as an assumption in the measuring) can reduce measurement overhead in high-frequency (e.g., millimeter-wave) scenarios requiring beam-based detection.

[0094] Herein, a high-frequency deployment may use millimeter-wave frequencies or FR2-like bands, e.g. where beamforming is extensively used. Furthermore, QCL (e.g. as an QCL assumption) may mean that one or more beams of the OD-SSB are considered to have spatial parameters (e.g., for reception at the radio device) correlated with one or more beams of the AO-SSB, e.g. allowing reuse of beam directions.

[0095] In a typical RAN using beamforming, the network node may signal that the OD-SSB is aligned or partially aligned with the AO-SSB. Hence, the radio device can avoid re-searching angle directions, e.g. thus speeding up cell synchronization and measurement updates.

[0096] The measuring may comprise prioritizing measurements of the OD-SSB in time and / or deferring neighbor-cell measurements on the AO-SSB frequency resource or on a frequency resource other than the OD-SSB frequency resource.For example, the neighbor-cell measurements may be deferred until a completion of the measurement of the OD-SSB.

[0097] Method embodiments can increase measurement responsiveness by focusing on the OD-SSB first. The radio device may quickly update serving-cell metrics, potentially enabling faster cell configuration changes or updates before resuming neighbor-cell scanning.

[0098] Prioritizing the OD-SSB measurements may refer to a scheduling decision in the radio device's measurement controller where OD-SSB scanning is allocated higher priority over other tasks. For example, when the network node triggers (e.g., according to the control message and / or due to an urgent event) the measuring on the OD-SSB frequency resource for cell reconfiguration, the radio device may (e.g., momentarily) defer neighbor-cell scans. Thereby, embodiments can achieve minimal latency in measuring the (e.g., newly activated) OD-SSB (e.g., OD-SSB beams).

[0099] The control message or the configuration message may configure a measurement object of the OD-SSB and / or a measurement object of the AO-SSB in the radio device.

[0100] Alternatively or additionally, a measurement object of the OD-SSB may be configured in the radio device.

[0101] Alternatively or additionally, a measurement object of the AO-SSB may be configured in the radio device.

[0102] Alternatively or additionally, each measurement object in the control message or the configuration message may define whether a frequency resource of the respective measurement object is treated as intra-frequency resource or interfrequency resource.

[0103] Alternatively or additionally, each measurement object in the control message or the configuration message may define whether the measurement of the respective measurement object is an intra-frequency measurement or an inter-frequency measurement.

[0104] Method embodiments can enable flexible measurement strategies by letting the network node, or a higher-layer controller of the RAN, specify for each frequency resource (or each measurement object) if it is considered intra-frequency (e.g., measured or measurable by the radio device without a dedicated measurementgap) or inter-frequency (e.g. requiring a measurement gap or retuning at the radio device).

[0105] The measurement object may be a configuration element (e.g., configured at the radio device) storing parameters for how the radio device measures signals on one or more frequencies. Moreover, inter-frequency may refer to a radio resource is out-of-band or outside an active BWP or outside a carrier bandwidth of the radio device and / or that requires a separate measurement gap or retuning of the radio device to measure signals on the radio resource.

[0106] For example, the network node may provide (e.g., in the control message or configuration message) a list of frequencies and flags each of them as either intrafrequency or inter-frequency. The radio device then adapts its measurement schedule and resource allocation accordingly.

[0107] The or each measurement object may further comprise a field parameter within the measurement object to indicate or distinguish between AO-SSB frequency resource and OS-SSB frequency resource.

[0108] The measuring may handle the or each measurement object (MO) according to the respectively indicated type. The control message or the configuration message may refine the measurement process by explicitly classifying frequencies for OD-SSB vs. AO-SSB. The radio device may optimize scanning times, measurement periodicities, and / or concurrency rules for each frequency type.

[0109] The field parameter may be a single-bit flag or a multi-valued parameter in the measurement object that specifies whether the frequency is activated or deactivated or used for OD-SSB, AO-SSB, or both.

[0110] In a RAN with multiple cells, the control message and / or the configuration may refer to or specify for each cell at least one of measurement objects and OD-SSB frequency resources and AO-SSB frequency resources. The radio device may process the received configuration parameters to build an internal measurement schedule.

[0111] The method may further comprise transmitting a measurement report to the network node based on and / or upon completion of the measurement of the OD-SSB and / or the AO-SSB.For example, the measurement report may enable the network node to adjust or deactivate OD-SSB transmissions based on the reported result of the measurement.

[0112] Embodiments allow the network node to quickly adapt or turn off OD-SSB once the radio device's measurement objectives are met, reducing network energy usage while ensuring the radio device and its serving cell remain in synchronization.

[0113] The measurement report may be indicative of signal quality metrics and / or cell identities (CID) and / or beam indices acquired during the OD-SSB measurement. Upon receiving, from the radio device, the measurement report that is indicative of sufficient synchronization or acceptable signal quality, the network node may switch the OD-SSB off to reduce power consumption, or change transmission intervals for improved resource utilization.

[0114] The control message may comprise an updated control, or the method may further comprise receiving, from the network node, an updated control, that OD-SSB transmissions are deactivated or reconfigured. In response, the measuring may be updated to exclude OD-SSB or to modify OD-SSB scanning periodicity.

[0115] Alternatively or additionally, the updated control may be comprised in the control message.

[0116] Alternatively or additionally, the method may further comprise receiving the updated control from the network node.

[0117] Alternatively or additionally, updating the measuring may exclude OD-SSB.

[0118] Alternatively or additionally, updating the measuring may modify OD-SSB scanning periodicity.

[0119] The device may adapt seamlessly whenever OD-SSB availability changes, e.g. as indicated in the control message or a further (e.g., updated) control message. This signaling can avoid measurement attempts when OD-SSB is deactivated and / or may maintain an accurate measurement timeline of the radio device.

[0120] The updated control may take the form of a high-level reconfiguration message (e.g., RRC signaling) from the network node, e.g. instructing the radio device to revise its measurement.For instance, once the radio device reports to the network node that signal quality is acceptable, the network node may decide to reduce usage of the OD-SSB (i.e., of the OD-SSB frequency resource). The radio device may then stop scanning or adjusts how frequently it measures for OD-SSB (e.g., OD-SSB beams).

[0121] The measuring may comprise, for neighbor cells whose SSB frequency resource (e.g., center frequency) matches the OD-SSB or AO-SSB resource frequency (e.g., center frequency) of the serving cell, performing a neighbor-cell measurement on the SSB frequency resource of the neighbor cell as an intra-frequency measurement. Thus, embodiments of the method may bypass dedicated measurement gaps.

[0122] Embodiments may optimize neighbor-cell monitoring. When neighbor cells use the same center frequency as the serving cell (e.g. for OD-SSB and / or AO-SSB), the radio device may reuse the same receiver channel settings for neighbor-cell measurements and / or without scheduling separate gaps. For example, in a multicell RAN covering overlapping frequency resources, the radio device can unify neighbor-cell and serving-cell measurements for more coherent mobility management and smoother handovers.

[0123] Herein, bypassing dedicated measurement gaps may means that the radio device continually monitors neighbor synchronization signals within the same frequency resource, obviating arrangement of off periods or re-tuning intervals.

[0124] In contrast, the method may further comprise determining that a further SSB (e.g., AO-SSB or OD-SSB) frequency resource of a neighbor cell is within a carrier frequency band of a serving cell serving the radio device and / or outside a currently active BWP of the radio device. The measuring may, responsive to the determination, comprises an inter-frequency measurement of the SSB of the neighbor cell and / or the radio device may use a dedicated gap or retuning procedure to perform the measurement of the SSB of the neighbor cell. The method may further comprise the radio device retuning when measurements become inter-frequency due to being outside of one or more active bandwidth parts (optionally although a partial frequency overlap) of the radio device.

[0125] Herein, a (dedicated) measurement gap may involve momentarily ceasing or limiting serving-cell reception, and / or transmission and / or retuning a carrier frequency of the radio device, to measure in another portion of the band. In practice, a carrier may be subdivided into multiple bandwidth parts. If the neighbor cell (e.g., the further OD-SSB of the neighbor cell) is in a different sub-range of the band outside the BWP of the serving cell, the radio device recognizes the need to switch resources or schedule measurement gaps.

[0126] The network node may serve the radio device using one or more radio access technologies (RAT). Furthermore, the method may comprise designating, by the radio device, at least some of the measuring or further measurements as inter-RAT measurements (e.g., inter-technology or inter-radio-access measurements) if a neighbor cell is operating on a different radio access technology or in a different frequency band. By distinguishing entirely separate bands or radio-access technologies, embodiments allow the radio device to follow a standard approach for cross-band or cross-technology measurements, including possible measurement-gap usage or retuning. Inter-RAT measurements may comprise scanning for (e.g., synchronization or other reference) signals that are not compatible or co-located with the serving cell's technology or frequency band. In some systems, the network node may coordinate deployments of multiple RAT, and / or the radio device may handle multiple RAT systematically,

[0127] e.g. differentiating them from OD-SSB and / or AO-SSB that share a band and / or the RAT with the serving cell of the network node.

[0128] The method may further comprise receiving, optionally in the control message, a mobility command from the network node specifying that the measuring by the radio device comprises handover-related measurements on the OD-SSB frequency resource, the AO-SSB frequency resource, or both.

[0129] For example, the mobility command may be received in the control message. Method embodiments can ensure that the radio device follows mobility-related instructions regarding which SSB to measure, preventing confusion and facilitating timely handover decisions. The mobility command may be a higher-layer message from the network node instructing the device to prepare for or perform mobility actions toward a target cell. For example, the radio device may be nearing celledge coverage. The network node may choose the best frequency resource, out of the OD-SSB frequency resource and the AO-SSB frequency resource, to base the handover decision upon, e.g., depending on coverage or energy-saving considerations.

[0130] The measuring may comprise, upon receiving, optionally in the control message, an indication that measuring the OD-SSB is prioritized for mobility, skipping neighbor-cell measurements on an or the AO-SSB.For example, the indication that measuring the OD-SSB is prioritized for mobility may be received in the control message.

[0131] For example, the neighbor-cell measurements on an or the AO-SSB may be skipped for a predefined time interval.

[0132] The radio device may temporarily focus resources on OD-SSB. Embodiments may avoid measurement overload on the radio device. By focusing on OD-SSB, the radio device may quickly finalize a handover decision, e.g. beneficial in time-critical or high-interference conditions.

[0133] Herein, the on-demand timer and / or the predefined time interval may be a period defined (e.g., configured) by the network node and / or by a technical standard. Alternatively or in addition, the on-demand timer and / or the predefined time interval may be defined in terms of a number of frames or slots of the serving cell for the radio device. Similar mechanisms, as described for mobility, may be applied if the network node indicates another urgent reconfiguration. The radio device may dedicate its resources to measuring OD-SSB. Once complete, the radio device may revert to normal scanning.

[0134] The method may further comprise, upon receiving in the control message an indication that network node transmissions of both OD-SSB and AO-SSB are active in the same radio cell, measuring both OD-SSB and AO-SSB frequency resources. For example, the method may further comprise updating beam or synchronization parameters based on the combined measuring of OD-SSB and AO-SSB.

[0135] Method embodiments can enable the radio device to gather spatial information from both SSB types, improving accuracy of, or shortening the time for, beamforming decisions and synchronization in time and / or frequency domain. The updating of beam or synchronization parameters may comprise (e.g., dynamically) selecting or refining one or more beam directions for radio communication with the network node, e.g., in high-frequency scenarios or RF2. For example, if the network node uses AO-SSB as a baseline but also activates OD-SSB for bursts of improved coverage or capacity, the radio device can align or compare measurements from both signals to refine its beam configuration.

[0136] The method may further comprise applying separate or combined beam management procedures to OD-SSB and AO-SSB based on quasi co-location (QCI), or transmission configuration information (TCI), received from the network node.For example, the QCI or TCI may be received in the control message or the configuration message.

[0137] Herein, TCI may include parameters that indicate spatial and timing alignments or distinctions between OD-SSB and AO-SSB, e.g. guiding how beams can be merged or separated.

[0138] Embodiments can augment flexibility by allowing the radio device to selectively combine, or treat separately, beams associated with OD-SSB and AO-SSB, e.g. leading to more adaptive and accurate beam steering or selection. In a RAN that employs multiple beam sets for coverage (e.g., a dense multi-beam deployment), the radio device may interpret TCI from the network node to handle OD-SSB and / or AO-SSB in a more power-efficient and performance-optimal way, or coordinating them for improved throughput or coverage.

[0139] As to a second method aspect, a method performed by a network node of a radio access network (RAN) is provided. The method comprises transmitting, to a radio device, a control message that is indicative of measuring at least one of always-on synchronization signal blocks (AO-SSB) on an AO-SSB frequency resource and on-demand synchronization signal blocks (OD-SSB) on an OD-SSB frequency resource. The method further comprises receiving, from the radio device, a measurement report that is indicative of results of measuring on at least one of the AO-SSB frequency resource and the OD-SSB frequency resource.

[0140] Alternatively or additionally, the control message may be indicative of measuring AO-SSB on the AO-SSB frequency resource, and the measurement report may be indicative of results of measuring on the AO-SSB frequency resource.

[0141] Alternatively or additionally, the control message may be indicative of measuring OD-SSB on the OD-SSB frequency resource, and the measurement report may be indicative of results of measuring on the OD-SSB frequency resource.

[0142] The measurement report may be received in response to the transmitted control message.

[0143] The method may further comprise the features and steps according to any one of the embodiments of the first method aspect, or corresponding features and steps applied mutatis mutandis according to any one of the embodiments of the first method aspect.As to another aspect, a computer program product is provided. The computer program product comprises program code portions for performing any one of the steps of the first or second method aspect disclosed herein when the computer program product is executed by one or more computing devices. The computer program product may be stored on a computer-readable recording medium. The computer program product may also be provided for download, e.g., via the radio network, the RAN, the Internet and / or the host computer. Alternatively, or in addition, the method may be encoded in a Field-Programmable Gate Array (FPGA) and / or an Application-Specific Integrated Circuit (ASIC), or the functionality may be provided for download by means of a hardware description language.

[0144] As to a first device aspect, a device for measuring SSB is provided. The device may be configured to perform any one of the steps of the first method aspect. As to a further first device aspect, a device for measuring SSB is provided. The device comprises processing circuitry (e.g., at least one processor and a memory). Said memory comprises instructions executable by said at least one processor whereby the device is operative to perform any one of the steps of the first method aspect.

[0145] As to a second device aspect, a device for controlling SSB measurements is provided. The device may be configured to perform any one of the steps of the second method aspect. As to a further second device aspect, a device for controlling SSB measurements is provided. The device comprises processing circuitry (e.g., at least one processor and a memory). Said memory comprises instructions executable by said at least one processor whereby the device is operative to perform any one of the steps of the second method aspect.

[0146] As to a still further aspect a communication system comprising at least one radio device and at least one network node according to the afore-mentioned aspects is provided. Alternatively or in addition, communication system comprises a host computer. The host computer comprises a processing circuitry configured to provide user data, e.g., included in a secondary cell synchronized using the subject technique. The host computer further comprises a communication interface configured to forward the user data to a cellular network (e.g., the RAN and / or the base station) for transmission to a UE. A processing circuitry of the cellular network is configured to execute any one of the steps of the second method aspects. The UE comprises a radio interface and processing circuitry, which is configured to execute any one of the steps of the first method aspects.The communication system may further include the UE. Alternatively, or in addition, the cellular network may further include one or more base stations configured for radio communication with the UE and / or to provide a data link between the UE and the host computer using the first and / or second method aspects.

[0147] The processing circuitry of the host computer may be configured to execute a host application, thereby providing the user data and / or any host computer functionality described herein. Alternatively, or in addition, the processing circuitry of the UE may be configured to execute a client application associated with the host application.

[0148] Any one of the devices, the UE, the network node, the base station, the communication system or any node or station for embodying the technique may further include any feature disclosed in the context of the method aspect, and vice versa. Particularly, any one of the units and modules disclosed herein may be configured to perform or initiate one or more of the steps of the method aspect.

[0149] Brief Description of the Drawings

[0150] Further details of embodiments of the technique are described with reference to the enclosed drawings, wherein:

[0151] Fig. 1 shows a schematic block diagram of an embodiment of a device for measuring SSB;

[0152] Fig. 2 shows a schematic block diagram of an embodiment of a device for controlling SSB measurements;

[0153] Fig. 3 shows a flowchart for a method of measuring SSB, which method may be implementable by the device of Fig. 1;

[0154] Fig. 4 shows a flowchart for a method of controlling SSB measurements, which method may be implementable by the device of Fig. 2;

[0155] Fig. 5 schematically illustrates a first example of a radio network comprising embodiments of the devices of Figs. 1 and 2 for performing the methods of Figs. 3 and 4, respectively;Fig. 6 schematically illustrates a second example of a radio network comprising embodiments of the devices of Figs. 1 and 2 for performing the methods of Figs. 3 and 4, respectively;

[0156] Fig. 7 schematically illustrates a third example of a radio network comprising embodiments of the devices of Figs. 1 and 2 for performing the methods of Figs. 3 and 4, respectively;

[0157] Fig. 8 schematically illustrates an exemplary time domain structure of SSB transmissions, which may be used in any embodiment of the devices of Figs. 1 and 2 when performing the methods of Figs. 3 and 4, respectively, in radio communication;

[0158] Fig. 9 schematically illustrates an exemplary time-frequency structure of SSB transmissions, which may be used in any embodiment of the devices of Figs. 1 and 2 when performing the methods of Figs. 3 and 4, respectively, in radio communication;

[0159] Fig. 10 shows a schematic block diagram of a radio device embodying the device of Fig. 1;

[0160] Fig. 11 shows a schematic block diagram of a network node embodying the device of Fig. 2; and

[0161] Fig. 12 schematically illustrates an example telecommunication network connected via an intermediate network to a host computer.

[0162] Detailed Description

[0163] In the following description, for purposes of explanation and not limitation, specific details are set forth, such as a specific network environment in order to provide a thorough understanding of the technique disclosed herein. It will be apparent to one skilled in the art that the technique may be practiced in other embodiments that depart from these specific details. Moreover, while the following embodiments are primarily described for a New Radio (NR) or 5G implementation, it is readily apparent that the technique described herein may also be implemented for any other radio communication technique, including aWireless Local Area Network (WLAN) implementation according to the standard family IEEE 802.11, 3GPP LTE (e.g., LTE-Advanced or a related radio access technique such as MulteFire), for Bluetooth according to the Bluetooth Special Interest Group (SIG), particularly Bluetooth Low Energy, Bluetooth Mesh Networking and Bluetooth broadcasting, for Z-Wave according to the Z-Wave Alliance or for ZigBee based on IEEE 802.15.4.

[0164] Moreover, those skilled in the art will appreciate that the functions, steps, units and modules explained herein may be implemented using software functioning in conjunction with a programmed microprocessor, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Digital Signal Processor (DSP) or a general purpose computer, e.g., including an Advanced RISC Machine (ARM). It will also be appreciated that, while the following embodiments are primarily described in context with methods and devices, the invention may also be embodied in a computer program product as well as in a system comprising at least one computer processor and memory coupled to the at least one processor, wherein the memory is encoded with one or more programs that may perform the functions and steps or implement the units and modules disclosed herein.

[0165] Fig. 1 schematically illustrates a block diagram of an embodiment of a device for performing the first method aspect and / or measuring synchronization signal blocks (SSB). The device is generically referred to by reference sign 100.

[0166] The device 100 comprises a control message reception module 104 that is operable to receive from the network node 200 a control message indicative of measuring at least one of always-on synchronization signal blocks (AO-SSB) and on-demand synchronization signal blocks (OD-SSB). The device 100 further comprises an SSB measurement module 106 that is operable to measure, in response to (e.g., according to) the received control message, at least one of the AO-SSB and the OD-SSB.

[0167] Any of the modules of the device 100 may be implemented by units configured to provide the corresponding functionality. The device 100 may also be referred to as, or may be embodied by, a radio device (or briefly: the UE). The radio device 100 and the network node may be in direct radio communication, e.g., at least for receiving the control message at the radio device 100. The network node may be embodied by below-mentioned device 200.Fig. 2 schematically illustrates a block diagram of an embodiment of a device for controlling SSB measurements and / or according to the first device aspect. The device is generically referred to by reference sign 200.

[0168] The device 200 comprises a Control Message Transmission Module 204 that is operable to transmit to a radio device a control message indicative of measuring at least one of an always-on synchronization signal block (AO-SSB, herein-below referred to by reference sign 901) on an always-on frequency resource (hereinbelow referred to by reference sign 911) and an on-demand synchronization signal block (OD-SSB, herein-below referred to by reference sign 902) on an on-demand frequency resource (herein-below referred to by reference sign 912).

[0169] Optionally, the device 200 comprises a Measurement Reception Module 208 that is operable to receive from the radio device (e.g., above-mentioned device 100) a measurement report indicative of results of measuring on at least one of the always-on frequency resource 911 and the on-demand frequency resource 912.

[0170] Any modules of the device 200 may be implemented by units configured to provide the corresponding functionality for controlling SSB measurements.

[0171] The device 200 may also be referred to as, or may be embodied by, a network node 200 (further below also referred to by reference sign 1100 and 1212). The network node 200 and the radio device 100 may be in direct radio communication, for example at least for the transmission of the control message to the radio device 100 and the reception of the measurement report from the radio device 100 at the network node 200. The radio device may be embodied by the above-mentioned device 100.

[0172] Fig. 3 illustrates an embodiment of a method 300 performed by a radio device 100. The radio device 100 and a network node 200 operate in a radio access network and exchange one or more messages that control synchronization signal measurements.

[0173] The method 300 may comprise a preparatory acquisition of basic configuration parameters (not shown in Fig. 3) that enable the radio device 100 to receive subsequent instructions and measure relevant signals.In an optional step 302 (not shown in Fig. 3), the radio device 100 receives a configuration message from the network node 200. This message configures the radio device 100 to handle at least one of always-on synchronization signal blocks (AO-SSB) 901 and on-demand synchronization signal blocks (OD-SSB) 902.

[0174] Optionally, the configuration message is indicative an AO-SSB frequency resource 911 and / or an OD-SSB frequency resource 912. In some embodiments, by defining these frequency resources early, the radio device 100 can treat them as intrafrequency resources or schedule them with reduced measurement gaps.

[0175] In a step 304 of the method 300, the radio device 100 receives a control message from the network node 200. This control message indicates whether the radio device 100 should measure the AO-SSB 901 on the AO-SSB frequency resource 911 and / or the OD-SSB 902 on the OD-SSB frequency resource 912. By signaling this choice dynamically, the network node 200 can switch to using exclusively OD-SSB 902, or may activate or deactivate OD-SSB 902, or keep only AO-SSB 901, so that the radio device 100 conserves processing and reduces measurement overhead. In a variant, the frequency resource is not indicated in the configuration message but in the control message.

[0176] In a step 306 of the method 300, the radio device 100 measures, e.g. following the instructions of the control message, on the indicated AO-SSB frequency resource 911 and / or the OD-SSB frequency resource 912. Depending on the control message, the radio device 100 can focus its receiver on the AO-SSB 901 if no additional resources are needed, or switch to the OD-SSB 902 if higher measurement granularity is required. This step 306 ensures that the radio device 100 remains adaptable to changing network conditions and power-saving configurations.

[0177] In a step 308 of the method 300, the radio device 100 transmits a measurement report to the network node 200. This report reflects the results of measuring 306 on the AO-SSB 901 and / or the OD-SSB 902. Based on the measurement report, the network node 200 may maintain, modify, or deactivate the OD-SSB 902 transmissions to reduce power consumption without jeopardizing synchronization quality.

[0178] The method 300 may be performed by the device 100. For example, the modules 104 and 106 may perform the steps 304 and 306, respectively.Fig.4 depicts a flowchart for a method 400 performed by a network node 200. The method 400 controls measurements of an always-on synchronization signal block (AO-SSB) frequency resource and / or an on-demand synchronization signal block (OD-SSB) frequency resource at a radio device 100.

[0179] In an optional step 402 (not shown in Fig. 4, indicated in later Fig. 5), the network node 200 may preconfigure (e.g. using radio resource control, RRC, and / or by defining a transmission configuration indicator, TCI, state) AO-SSB reception and OD-SSB reception at the radio device 100.

[0180] In a step 404, the network node 200 transmits a control message to the radio device 100. The control message indicates whether the radio device 100 is to measure on the always-on (AO) frequency resource or the on-demand (OD) frequency resource, or both. This selective indication enables the network node 200 to adapt measurement overhead to prevailing network conditions and conserve power when fewer measurements are needed.

[0181] Once the radio device 100 completes its measurements, the network node 200 receives 408 a measurement report that reflects results of measuring the AO frequency resource or the OD frequency resource.

[0182] The network node 200 may evaluate these results to refine future measurement instructions— for instance, deactivating on-demand transmissions or altering measurement periodicities. This may lead to transmitting 402 an updated configuration message and / or transmitting 404 an updated control message, e.g. in a loop of the method 400.

[0183] The method 400 may be performed by the device 200. For example, the modules 204 and 208 may perform the steps 404 and 408, respectively.

[0184] In any aspect, the technique may be applied to uplink (UL), downlink (DL) or direct communications between radio devices, e.g., device-to-device (D2D) communications or sidelink (SL) communications.

[0185] Each of the transmitting station 100 and receiving station 200 may be a radio device or a base station. Herein, any radio device may be a mobile or portable station and / or any radio device wirelessly connectable to a base station or RAN, or to another radio device. For example, the radio device may be a user equipment(UE), a device for machine-type communication (MTC) or a device for (e.g., narrowband) Internet of Things (IoT). Two or more radio devices may be configured to wirelessly connect to each other, e.g., in an ad hoc radio network or via a 3GPP SL connection. Furthermore, any base station may be a station providing radio access, may be part of a radio access network (RAN) and / or may be a node connected to the RAN for controlling the radio access. For example, the base station may be an access point, for example a Wi-Fi access point.

[0186] For example, the network node 200 may change usage and transmission of AO-and / or OD-SSB according to the control message depending on noise or a signal-to-noise ratio (SNR), and / or interference or a signal-to-interference-and-noise ratio (SINR) on a channel or radio link (e.g., responsive to the measurement report).

[0187] Furthermore, "predefined" may encompass stored in memory (e.g., in a Subscriber Identity Module, SIM) of the transmitting wireless device, or hard-coded or hard-wired in the transmitting wireless device, or preconfigured or configured by a network node or radio access network (RAN) for the transmitting wireless device (e.g., preconfigured while in coverage prior to performing the method out of coverage, or configured while in coverage when performing the method).

[0188] The radio spectrum shared by multiple RATs and / or in FR2 may comprise an unlicensed spectrum.

[0189] Herein, a list of the form A, B, and / or C (also written as A, B and / or C) may correspond to at least one or each of A, B, and C, i.e., A and / or B and / or C.

[0190] Fig. 5 illustrates a radio network 500 that encompasses a radio device 100 and a network node 200. This arrangement provides a framework for exchanging messages that trigger, execute, and report measurements of synchronization signal blocks. The presence of the radio network 500 ensures that the radio device 100 and the network node 200 can communicate seamlessly under unified protocols.

[0191] In Fig. 5, the radio device 100 performs a method 300 that includes receiving, in steps 302 and 304, one or more configuration and / or control messages from the network node 200. These control messages indicate whether the radio device100 should measure on at least one of an always-on or on-demand frequency resource. By following the instructions received in steps 302 and 304, the radio device 100 can adapt its SSB measurement efforts, e.g. in real time.

[0192] As indicated in Fig. 5, the configuration and / or control messages may be received using RRC and / or DCI signaling.

[0193] Once configured, the radio device 100 proceeds with the measurement step 306 to evaluate the indicated frequency or frequencies. This measurement step 306 enables efficient synchronization and resource utilization, since the radio device 100 only focuses on SSB transmissions that are currently relevant according to the signaling received 302, 304. Upon obtaining its measurement results, the radio device 100 sends 308 a measurement report back to the network node 200 so that the network node 200 can make timely adjustments to on-demand transmissions.

[0194] Meanwhile, the network node 200 carries out a method 400, where it transmits messages 402 and 404 to configure and control, respectively, (e.g., refine) measurement tasks at the radio device 100. In step 408, the network node 200 receives the measurement report from the radio device 100. The network node 200 uses the incoming data to modify or deactivate synchronization signals when they are no longer needed. This interactive control loop between the radio device 100 and the network node 200 ultimately reduces SSB overhead in the radio network 500 and improves power efficiency.

[0195] Fig. 6 depicts a second example scenario with carrier aggregation (CA), i.e. a radio device 100 connects to a network node 200 over two concurrently active cells, i.e. serving cells. The radio device 100 is linked to a primary cell (e.g., PCell) 601 and a secondary cell (e.g., SCell) 602. This arrangement allows the radio device 100 to receive baseline connectivity via the primary cell 601 while boosting capacity and throughput via the secondary cell 602. An advantage of this split is that extra data flows can be handled over the secondary cell 602 without disrupting the primary cell 601.

[0196] The network node 200 provides a multi-layer architecture including the layers SDAP (Service Data Adaptation Protocol), PDCP (Packet Data Convergence Protocol), RLC (Radio Link Control), MAC (Medium Access Control), and PHY (Physical Layer).These layers collaborate sequentially to serve both a primary cell 601 and a secondary cell 602. The primary cell 601 retains essential scheduling duties and transmits baseline control channels, while the secondary cell 602 contributes extra spectrum to boost data throughput. This cooperative structure allows the network node 200 to flexibly allocate transmission blocks across multiple carriers and balance load according to current conditions.

[0197] In one interpretation, each PHY layer protocol data unit, i.e., transport block (TB), in the network node 200 is represented in Fig. 6 by one of the sequential labels 1, 2, 3, and 4. Two of these PDU are handled by the primary cell 601, and the other two handle are handled by the secondary cell 602, so that the radio device 100 can receive packet data from both cells in parallel. Through these distinct lower-layer paths, the radio device 100 obtains improved coverage and high data rates, while the network node 200 maintains separate yet synchronized control of each carrier.

[0198] In another interpretation, between the radio device 100 and the network node 200, there are four IP flows labeled 1, 2, 3, and 4. Flows 1 and 2 correspond to primary traffic over the primary cell 601, and flows 3 and 4 handle secondary traffic over the secondary cell 602. By separating the flows, Fig. 6 illustrates how the primary cell 601 and the secondary cell 602 can each be monitored or measured, which is key to efficiently activating and deactivating on-demand transmissions.

[0199] In one variant of any embodiment of any aspect, the technique is applied to the secondary cell 602. The frequency resources of both the AO-SSB and the OD-SSB are in the carrier bandwidth of the secondary cell 602.

[0200] In another variant, the carrier bandwidth is split (e.g., using carrier bandwidth parts, BWP) between the two PHY layer entities forming the primary cell 601 and the secondary cell 602, respectively. The network node may activate and deactivate the secondary cell 602 by activating and deactivating, respectively, the OD-SSB on the secondary cell, while the AO-SSB are transmitted on (and thus identify) the primary cell 601. In other words, in the second variant, the radio device 100 may measure the secondary cell 602 by (e.g., selectively according to the control message) measuring on the OD-SSB frequency resource, whilesimultaneously measuring the primary cell 601 by measuring on the AO-SSB frequency resource.

[0201] In either variant, by applying the methods 300 and 400, the radio device 100 can adapt more readily to changes in network load and energy-saving configurations.

[0202] While arrows in Fig. 6 focus on the downlink (DL), the radio device 100 may transmit data using outgoing signals on the two PHY layers of the two serving cells, i.e. in the uplink (UL).

[0203] In Fig. 7, a dual connectivity (DC) scenario is schematically shown with a radio device 100 served by a master node MN 200 and a secondary node SN 200 as embodiments of the network node. A master cell group MCG is anchored by the master node 200, and a secondary cell group SCG is provided by the secondary node 200, thereby offering separate resources that operate in parallel for the radio device 100.

[0204] The radio device 100 communicates with the master node 200 over a primary cell PCell 601 on link 1 and simultaneously uses a primary secondary cell (PSCell) 602 on link 2 to exchange data with the secondary node 200. This concurrent activation of link 1 and link 2 augments available spectrum, boosting throughput and improving reliability across the master cell group MCG and the secondary cell group SCG.

[0205] Within the master node 200, an RLC layer, a MAC layer, and a PHY layer manage transmissions on link 1, while the secondary node 200 features a corresponding set of radio link layers for link 2. Above these layers, the master node 200 implements SDAP and PDCP functions that coordinate packet flows and ensure consistent delivery. A forwarding tunnel interconnects the master node 200 and the secondary node 200, thereby enabling flexible redirection of user-plane data between the two nodes so that the radio device 100 sees a unified service.

[0206] Moreover, the forwarding tunnel may carry higher-layer traffic between the master cell group MCG and the secondary cell group SCG, helping the RAN 500 decide which link is best for a given packet flow. This arrangement allows the radio device 100 to maintain robust connectivity under varying load conditions and switch easily between link 1 and link 2 as throughput demands evolve or as channel quality fluctuates.By taking advantage of both a PCell 601 and a PSCell 602 in the dual connectivity setup, the radio device 100 gains access to additional spectrum resources, thereby lowering latency and raising overall data rates. Because the master node 200 and the secondary node 200 interact seamlessly via the forwarding tunnel, the RAN 500 is free to implement further optimizations— such as activating on-demand synchronization signal blocks— so that cell configurations can be adapted quickly and power efficiency can be improved.

[0207] For example, in one variant of any embodiment of any aspect, the technique is applied to the primary secondary cell 602. The frequency resources of both the AO-SSB and the OD-SSB are in the carrier bandwidth of the primary secondary cell 602.

[0208] In another variant, the carrier bandwidth of the radio device 100 is split (e.g., using carrier bandwidth parts, BWP) between the two (e.g., distributed unit, DU) protocol stacks (e.g., RLC, MAC, and PHY) forming the primary cell 601 and the primary secondary cell 602, respectively. The network node 200 may activate and deactivate the primary secondary cell 602 by activating and deactivating, respectively, the OD-SSB on the primary secondary cell, while the AO-SSB are transmitted on (and thus identify) the primary cell 601. In other words, in the second variant, the radio device 100 may measure the primary secondary cell 602 by (e.g., selectively according to the control message) measuring on the OD-SSB frequency resource, while simultaneously measuring the primary cell 601 by measuring on the AO-SSB frequency resource.

[0209] Any embodiment of the method 300 may be implemented as an OD-SSB measurement for OD-SSB and AO-SSB having different (e.g., center) frequencies.

[0210] In a variant of any embodiment of any aspect, both the measuring of the AO-SSB and the measuring of the OD-SSB may be part of serving cell measurements. In another variant, the measuring of the AO-SSB and the measuring of the OD-SSB may be a serving cell measurement and a neighbor cell measurement, respectively. In both variants, the AO-SSB measurement and the OD-SSB measurement may be intra-frequency measurements.

[0211] For brevity and not limitation, the radio device 100 is referred to as a UE 100 and the network node 200 is referred to as a gNB 200 or network (NW) in the followingdescription of embodiments, each of which may combined with the embodiments in the appended list.

[0212] At least some embodiments of the technique may address or meet objectives of the 3GPP Release 19 Work Item on Enhancements of network energy savings for NR. For example, the 3GPP Release 19 Work Item entitled " Enhancements of network energy savings for NR" includes the following objective related to on-demand SSB transmission (cf. Work Item Description 3GPP RP-234065, December 2023):

[0213] 1. Specify procedures and signaling method(s) to support on-demand SSB SCell operation for UEs in connected mode configured with CA, for both intra- / inter-band CA. [RAN1 / 2 / 3 / 4]

[0214] 8Specify triggering method(s) (select from UE uplink wake-up-signal using an existing signal / channel, cell on / off indication via backhaul, Scell activation / deactivation signaling)

[0215] 8Notel: On-demand SSB transmission can be used by UE for at least SCell time / frequency synchronization, L1 / L3 measurements and SCell activation, and is supported for FR1 and FR2 in non-shared spectrum.

[0216] Any embodiment may reuse mechanisms of intra-frequency measurement, e.g. embodiments of the methods 300 and 400 may comprise at least one of the following features and steps.

[0217] Intra-frequency measurement requirement is defined in TS 38.133 (e.g., version 18.5.0, particularly in clause 9. ID) as follows.

[0218] A measurement is defined as a SSB based intra-frequency measurement provided the center frequency of the SSB of the serving cell indicated for measurement and the center frequency of the SSB of the neighbor cell are the same, and the subcarrier spacing of the two SSB are also the same.

[0219] If the UE supports non-cell-defining SSB, e.g. ncd-SSB-BWP-Wor-rl8, a measurement is defined as a SSB based intra-frequency measurement provided the center frequency of the reference SSB of the serving cell and the center frequency of the SSB of the neighbor cell are the same, and the subcarrier spacing of the two SSB are also the same. The reference SSB is the SSB defined in BWP-specific servingCellMO under BWP-DownlinkDedicated of active DL BWP. If thefield is absent, the reference SSB is the SSB defined in servingCellMO under ServingCellConfig in TS 38.331, version 18.2.0.

[0220] Table 1: Measurement period for intra-frequency measurements without gaps (FR1)

[0221] DRX cycle T SSB_measurement_period_intra

[0222] No DRX max(200ms, ceil( 5 x Kp) x SMTC period)Note 1x CSSFintra

[0223] DRX cycle< 320ms max(200ms, ceil(1.5x 5 x Kp) x max(SMTC period, DRX cycle)) x CSSFintra DRX cycle>320ms cei 1 ( 5 x Kp) x DRX cycle x CSSFintra NOTE 1: If different SMTC periodicities are configured for different cells, the

[0224]

[0225] SMTC period in the requirement is the one used by the cell being identified

[0226] Table 2: Measurement period for intra-frequency measurements without gaps (FR2)

[0227] DRX cycle T SSB_measurement_period_intra

[0228] No DRX max(400mS, Ceil(Mmeas_Period_w / o_gaps X KpX Klayerl measurement) X SMTC period)^oteX CSSFintra

[0229] DRX cycle< 320ms max(400mS, ceil(1.5x Mmeas period w / o gaps X KpX Klayerl measurement) X max(SMTC period, DRX cycle)) x CSSFintra

[0230] DRX cycle>320ms Ceil(Mmeas_period_w / o_gaps XKPX

[0231] Klayerl measurement ) X DRX Cycle X CSSFintra NOTE 1: If different SMTC periodicities are configured for different cells, the

[0232]

[0233] SMTC period in the requirement is the one used by the cell being identified

[0234] Any embodiment may reuse mechanisms of deactivated SCell measurement, e.g. embodiments of the methods 300 and 400 may comprise at least one of the following features and steps. Deactivated SCell measurement requirement is defined in 3GPP TS 38.133, e.g. version 18.5.0, as follow.Table 3: Measurement period for intra-frequency measurements without gaps (deactivated SCell) (FR1)

[0235] DRX cycle T SSB_measurement_period_intra

[0236] No DRX Ceil(5 x Kp) x measCycleSCell x CSSFintra DRX cycle< 320ms Ceil(5 x Kp) x max(measCycleSCell,

[0237] 1.5xDRX cycle) x CSSFintra

[0238] DRX cycle> 320ms Ceil(5 x Kp) x max(measCycleSCell, DRX Cycle) X CSSFintra

[0239]

[0240] NOTE 1: The requirements also apply to deactivated SCG SCell.

[0241] Table 4: Measurement period for intra-frequency measurements without gaps (deactivated SCell) (FR2)

[0242] DRX cycle T SSB_measurement_period_intra

[0243] No DRX Ceil(Mmeas_period_w / o_gaps X Kp) X measCycleSCell x CSSFintra

[0244] DRX cycle< 320ms Ceil(Mmeas_period_w / o_gaps X Kp) X max(measCycleSCell, 1.5xDRX cycle) x CSSFintra

[0245] DRX cycle> 320ms Ceil(Mmeas_period_w / o_gaps X Kp) X max(measCycleSCell, DRX cycle) x CSSFintra

[0246]

[0247] NOTE 1: The requirements also apply to deactivated SCG SCell.

[0248] Moreover, the deactivated SCell measurement cycle is configured in the Information Element (IE) MeasObjectNR according to 3GPP TS 38.331, e.g. version 18.0.0 as follows.

[0249] measCycleSCell ENUM ERA TED {sfl 60, sf256, sf320, sf512, sf640, sfl024, sfl280}

[0250] measCycleSCell

[0251] The parameter is used only when an SCell is configured on the frequency indicated by the measObjectNR and is in deactivated state, see TS 38.133. gNB configures the parameter whenever an SCell is configured on the frequency indicated by the measObjectNR, but the field may also be signaled when an SCell is not configured. Value sfl60 corresponds to 160 sub-frames, value sf256

[0252]

[0253] corresponds to 256 sub-frames and so on.Any embodiment may reuse or modify a time domain structure of the SSB 901, 902, e.g. embodiments of the methods 300 and 400 may comprise at least one of the following features and steps of an SSB measurement time configuration (SSB-MTC or SMTC).

[0254] NR synchronization signal (SS) consists of primary SS (PSS) and secondary SS (SSS). NR physical broadcast channel (PBCH) carries the very basic system information. In NR PSS, PBCH and SSS are always transmitted together and the combination of PSS, SSS and PBCH is referred as SSB in NR. Multiple SSB are transmitted in a localized burst set. Within an SS burst set, multiple SSB can be transmitted in different beams. The transmission of SSBs within a localized burst set is confined to a 5 ms window and the SSB and SSB burst set are repeated in a periodic manner. The SSB periodicity can be configured from the value set {5, 10, 20, 40, 80, 160} ms.

[0255] SSB is primarily used for performing the Radio resource Management (RRM) measurements, beam measurements, synchronization measurements, etc. Since SSB periodicity can be as low as 5 ms, UE do not need to perform RRM measurements or beam management measurements or synchronization measurements with the periodicity of SSB. To inform the UE about the SSB measurement periodicity, in NR SSB measurement time configuration (SMTC) is introduced. SMTC consists of SMTC periodicity and SMTC window length. In NR, since different beams can be configured to cover different spatial implementation, UE do not need to measure all the spatial directions. The beams to be measured can be controlled or configurable through SMTC window. SMTC window length indicates the location of the SSB to be measured within the SSB burst set. The signaling of SMTC window informs the UE 100 of the timing and periodicity of the one or more SSB that the UE can use for measurements. The SMTC window periodicity can be configured from the value set {5, 10, 20, 40, 80, 160} ms, matching the possible SSB periodicities. The SMTC window duration can be configured from the value set {1, 2, 3, 4, 5} ms. The SMTC window duration may also be simply called as SMTC duration or SMTC length or SMTC occasion duration or SMTC occasion length etc.

[0256] Hereinbelow, the reference signs 901 and 902 are generically used to refer to SSB.

[0257] Fig. 8 provides an illustration of SSB time domain and SMTC window.At least some embodiments of the technique may improve or modify current technical specifications. E.g., embodiments of the methods 300 and 400 may improve at least one of the following current states.

[0258] As a first current state, in RANI #116 meeting, it was agreed that two scenarios, with or without always-on SSB(AO-SSB) will be supported for on-demand SSB(OD- SSB).

[0259] Agreement

[0260] Regarding the UE assumption on SSB transmission on a cell supporting on- demand SSB SCell operation, the following cases are identified for further study:

[0261] Case #1: No always-on SSB on the cell

[0262]

[0263] Case #2: Always-on SSB is periodically transmitted on the cell

[0264] As a second current state, in RANI #119 meeting, it was agreed that AO-SSB and OD-SSB are staying in the same frequency location.

[0265] Agreement

[0266] Response to Q3 (What is the relation in terms of frequency location between the always-on SSB and OD-SSB?) of Obj.l:

[0267] The frequency location of on-demand SSB is the same as the frequency location of always-on SSB at least for the case where always-on SSB is not CD- SSB. RANI is discussing the frequency location of OD-SSB for the case where

[0268]

[0269] always-on SSB is CD-SSB.As a third current state, in RANI #120 meeting, it was agreed that AO-SSB and OD-SSB can stay in different frequencies.

[0270] Agreement

[0271] Regarding the relation in terms of frequency location (i.e., center frequency) between the always-on SSB and on-demand SSB,

[0272] Alt 1: If always-on SSB is CD-SSB on a synchronization raster, the frequency location of on-demand SSB is different from the frequency location of always-on SSB.

[0273] On-demand SSB is not on sync raster

[0274] AO-SSB and OD-SSB are located in the same BWP

[0275] For Further Study: Additional conditions

[0276] Subject to separate UE capability

[0277]

[0278] - Note: UE is not required to measure both AO-SSB and OD-SSB

[0279] More specifically, at least some embodiments of the technique can address the following problems in above-mentioned current states of radio access technology. Network energy saving (NES), being of great importance for environmental sustainability, to reduce environmental impact (e.g., greenhouse gas emissions) and for operational cost savings, has been studied from Release 18. Regarding those promising techniques which were raised but not specified, it is agreed that Wl, RP-234065, in Release 19 aims to study and specify them including on-demand SSB and on-demand SIB1 transmissions, as well as adaptation of common signal / channel transmissions. Among them, on-demand SSB is considered to be an enhancement to SCell activation operation, the relevant objective is again cited as follows.

[0280] 1. Specify procedures and signaling method(s) to support on- demand SSB SCell operation for UEs in connected mode

[0281] configured with CA, for both intra- / inter-band CA. [RAN1 / 2 / 3 / 4]

[0282] • Specify triggering method(s) (select from UE uplink wake-up- signal using an existing signal / channel, cell on / off indication via backhaul, Scell activation / deactivation signaling)

[0283] • Notel: On-demand SSB transmission can be used by UE for at

[0284] least SCell time / frequency synchronization, L1 / L3measurements and SCell activation, and is supported for FR1

[0285] and FR2 in non-shared spectrum.

[0286] Herein, LI measurements may be used for beam selection. L3 measurements may be used for handover.

[0287] RANI has agreed to consider both OD-SSB and AO-SSB are transmitted in the same or different frequencies. However, there is ambiguity in the operation state of the UE. it is unclear how the on-demand SSB can be used for measurement, especially when the network transmits the OD-SSB in the different frequency as the AO-SSB. Furthermore, it is also unclear for the UE as to whether to measure neighbor cells on the AO-SSB frequency or on the OD-SSB frequency.

[0288] At least some embodiments beneficially improve the mechanism for gap-less measurements and / or related to intra-frequency measurements, applied to on-demand SSB measurements.

[0289] A general embodiment of the technique defines how to perform measurements using on-demand SSB transmissions 902, e.g. in an Scell 602. To achieve power savings in a network, with the help of the Network Energy Saving (NES) feature of Release 19, i.e., on demand SSB transmissions in general, the solution proposes how to indicate the UE to perform measurement once the RAN 500 (e.g., the network node 200) transmits both on-demand SSB (OD-SSB) 902 and always-on (AO-SSB) 901.

[0290] After UE 100 finished the measurements and reports 308 the measurement report, the NW 200 can have chance to go to sleep by turning off the on-demand SSB transmission or lowering down the transmission periodicity of on-demand SSB. It comprises a method 300 at a User Equipment (UE) 100 in which the UE 100 receives at least one message indicating the frequency as intra-frequency to perform measurement once NW 200 indicates 404 the OD-SSB transmission in a different frequency location as compared to the AO-SSB transmission.

[0291] Any embodiment of any aspect may comprise, alone or in addition to the claims and below embodiments, at least one of the following features and steps.

[0292] A general embodiment may introduce a control message, e.g., indicators and / or flags in the configuration, to indicate 404 the UE 100 to perform measurement 306 on which component, such as on-demand SSB (OD-SSB) frequency 912 and / oralways-on SSB (AO-SSB) frequency 911, if the NW 200 configures 402 both AO-SSB and OD-SSB and they are in different frequency location in the cell 601 or 602. When both the AO-SSB and the OD-SSB transmission in different frequency locations

[0293] When NW indicates OD-SSB transmission in fl, UE starts to perform measurement in fl, e.g. as illustrated at reference sign 911 in Fig. 9.

[0294] As such or in combination with the above features, the measurement can be an OD-SSB based L3 measurement or an OD-SSB based LI measurement.

[0295] As such or in combination with the above features, indicated by the mobility command from NW, e.g., handover / conditional handover, the measurement for mobility conducted by UE is based on OD-SSB or AO-SSB.

[0296] NW indicates the intra-frequency

[0297] As such or in combination with the above features, NW indicates which frequency is believed as the intra-frequency for the serving cell, either OD-SSB frequency or AO-SSB frequency or both frequencies.

[0298] As such or in combination with the above features, such indication can be explicitly based on NW signaling, such as OD-SSB indication, Measurement Objects configuration, or servingCellMO configuration

[0299] As such or in combination with the above features, UE performs neighbor cell measurement on AO-SSB frequency if NW indicates AO-SSB as the intra-frequency. As such or in combination with the above features, UE performs serving cell measurement on OD-SSB frequency if NW indicates AO-SSB as the intra-frequency. As such or in combination with the above features, UE performs intra-frequency serving and neighbor cell measurement on both AO-SSB and OD-SSB frequencies. As such or in combination with the above features, UE performs the neighbor cell measurement in intra-frequency in any SSB frequency based on NW indication. As such or in combination with the above features, UE performs both serving cell and neighbor cell measurement on OD-SSB frequency if NW indicates OD-SSB as the intra-frequency.As such or in combination with the above features, UE drops / skips / suspends the measurement on AO-SSB.

[0300] As such or in combination with the above features, UE switches to apply AO-SSB as intra-frequency if OD-SSB isn't able to be measured by UE, such as OD-SSB is deactivated by NW indication or OD-SSB transmission timer is expired.

[0301] OD-SSB frequency as Intra-frequency

[0302] As such or in combination with the above features, the OD-SSB frequency is intra-frequency and the AO-SSB frequency is inter-frequency once NW indicates the OD-SSB transmission.

[0303] As such or in combination with the above features, UE performs the neighbor cell measurement in intra-frequency with OD-SSB.

[0304] As such or in combination with the above features, UE performs the L3 interfrequency measurement for AO-SSB frequency with gap if the AO-SSB frequency is outside the active BWP; otherwise, UE performs the L3 inter-frequency measurement for AO-SSB frequency without gap.

[0305] AO-SSB frequency as Intra-frequency

[0306] As such or in combination with the above features, both OD-SSB frequency and AO-SB frequency are configured as intra-frequency.

[0307] As such or in combination with the above features, UE performs the neighbour cell measurement in intra-frequency in AO-SSB frequency.

[0308] As such or in combination with the above features, UE performs serving cell measurement in OD-SSB frequency if NW indicates OD-SSB transmission.

[0309] As such or in combination with the above features, UE performs the neighbor cell measurement in intra-frequency in both AO-SSB and OD-SSB frequency.

[0310] As such or in combination with the above features, UE performs the neighbor cell measurement in intra-frequency in any SSB frequency based on NW indication.FR2 Rx beam

[0311]

[0312] When NW indicates the OD-SSB transmission, UE shall assume OD-SSB is QCL Type-D with AO-SSB.

[0313] As such or in combination with the above features, when NW indicates the OD-SSB transmission, such QCL information between OD-SSB and AO-SSB can be configured by NW, such as by TCI state.

[0314] As such or in combination with the above features, UE performs fast measurement for serving cell without Rx beam sweeping in FR2 in OD-SSB frequency if OD-SSB is QCL'ed Type-D with AO-SSB.

[0315] As such or in combination with the above features, the SSB index can be reported by UE based on AO-SSB before OD-SSB indication.

[0316] As such or in combination with the above features, UE prioritize the fast measurement for OD-SSB frequency and suspend / extend the measurement for AO-SSB frequency.

[0317] As such or in combination with the above features, UE performs neighbor cell measurement in AO-SSB frequency.

[0318] As such or in combination with the above features, the neighbor cell measurement in AO-SSB frequency can be restarted after UE finishing the OD-SSB fast measurement in OD-SSB frequency.

[0319] Any embodiment as described above or in the claims may further comprise at least one of the following features from detailed embodiments.

[0320] Examples of network nodes are NodeB, base station (BS), multi-standard radio (MSR) radio node such as MSR BS, eNodeB, gNodeB, MeNB, SeNB, location measurement unit (LMU), integrated access backhaul (IAB) node, network controller, radio network controller (RNC), base station controller (BSC), relay, donor node controlling relay, base transceiver station (BTS), Central Unit (e.g. in a gNB), Distributed Unit (e.g. in a gNB), Baseband Unit, Centralized Baseband, C-RAN, access point (AP), transmission points, transmission nodes, transmission reception point (TRP), RRU, RRH, nodes in distributed antenna system (DAS), core network node (e.g. MSC, MME etc.), O& M, OSS, SON, positioning node (e.g. E-SMLC),etc.The non-limiting term UE refers to any type of wireless device communicating with a network node and / or with another UE in a cellular or mobile communication system. Examples of UE are target device, device to device (D2D) UE, vehicular to vehicular (V2V), machine type UE, MTC UE or UE capable of machine to machine (M2M) communication, PDA, tablet, mobile terminals, smart phone, laptop embedded equipment (LEE), laptop mounted equipment (LME), USB dongles etc.

[0321] The term radio access technology, or RAT, may refer to any RAT e.g. UTRA, E-UTRA, narrow band internet of things (NB-IoT), Wi-Fi, Bluetooth, next generation RAT, New Radio (NR), 4G, 5G, etc. Any of the equipment denoted by the term node, network node or radio network node may be capable of supporting a single or multiple RATs.

[0322] The term signal or radio signal used herein can be any physical signal or physical channel. Examples of DL physical signals are reference signal (RS) such as PSS, SSS, CSI-RS, DM-RS signals in SS / PBCH block (SSB), discovery reference signal (DRS), CRS, PRS etc. RS may be periodic e.g. RS occasion carrying one or more RSs may occur with certain periodicity e.g. 20 ms, 40 ms etc. The RS may also be aperiodic. Each SSB carries NR-PSS, NR-SSS and NR-PBCH in 4 successive symbols. One or multiple SSB are transmit in one SSB burst which is repeated with certain periodicity e.g. 5 ms, 10 ms, 20 ms, 40 ms, 80 ms and 160 ms. The UE is configured with information about SSB on cells of certain carrier frequency by one or more SS / PBCH block measurement timing configuration (SMTC) configurations. The SMTC configuration comprising parameters such as SMTC periodicity, SMTC occasion length in time or duration, SMTC time offset w.r.t. reference time (e.g. serving cell's SFN) etc. Therefore, SMTC occasion may also occur with certain periodicity e.g. 5 ms, 10 ms, 20 ms, 40 ms, 80 ms and 160 ms. Examples of UL physical signals are reference signal such as SRS, DM-RS etc. The term physical channel refers to any channel carrying higher layer information e.g. data, control etc. Examples of physical channels are PBCH, NPBCH, PDCCH, PDSCH, sPUCCH, sPDSCH, sPUCCH, sPUSCH, MPDCCH, NPDCCH, NPDSCH, E-PDCCH, PUSCH, PUCCH, NPUSCH etc.

[0323] The term A-TRS (Aperiodic-temporary reference symbol) used herein is a Release 17 application of a channel state information reference signal (CSI-RS) for the UE measurement to settle the AGC (automatic gain control) during the secondary cell activation timeline. A-TRS can be typical non-zero-power CSI-RS (NZP CSI-RS), which may follow the configuration from higher layer (e.g., RRC layer).The term time resource used herein may correspond to any type of physical resource or radio resource expressed in terms of length of time. Examples of time resources are: symbol, time slot, subframe, radio frame, transmission time interval (TTI), interleaving time, slot, sub-slot, mini-slot, system frame number (SFN) cycle, hyper-SFN (H-SFN) cycle etc.

[0324] The configuration and / or control message may comprise an OD-SSB measurement indication, e.g. according to at least one of the following examples.

[0325] Any embodiments of the methods 300 and 400 may be applied to at least one of the following scenarios (i.e., cases).

[0326] In one OD-SSB based SCell scenario (case 1), the NW 200 (e.g., the network node) refrains from configuring a UE 100 with SSB transmission. Afterwards, NW 200 may indicate a high-rate SSB periodicity, which is achieved by using, and / or referred to as, OD-SSB to perform measurements.

[0327] In another OD-SSB based SCell scenarios (case 2), the NW 200 may configure a UE 100 with SSB configuration with a low-rate SSB periodicity. Afterwards, the NW 200 can further indicate a high-rate SSB periodicity, which is achieved by using, and / or referred to as, OD-SSB to perform measurement.

[0328] In any case, the NW 200 may indicate (according to the steps 404 and 304) the OD-SSB transmission in time slot n, and the UE 100 may be expected to receive the OD-SSB transmission in time slot n+T, where T depends on UE's parsing time and other uncertain time, such as the offset of SSB transmission.

[0329] In case 2, when NW 200 configures OD-SSB 902 as the different frequency as AO- SSB, the method 400 to indicate 404 to the UE 100 to perform measurement 306 on which component is introduced, e.g., NW explicit indicators / flags in the configuration to indicate UE to perform measurement on which one or more frequencies, e.g. on-demand SSB (OD-SSB) frequency 912 and / or always-on SSB (AO-SSB) frequency 911 if NW configures 402 both AO-SSB and OD-SSB and their frequency locations in the cell are different.

[0330] For example, NW configures AO-SSB in fO, and NW configures OD-SSB in fl. The AO-SSB and OD-SSB can be configured in the same BWP.

[0331] As illustrate in the Fig. 9, when there is an AO-SSB transmission in fO (at reference sign 911), the UE 100 shall perform intra-frequency measurement on AO-SSB frequency if there is no OD-SSB transmission.When the NW 200 indicates OD-SSB transmission in fl (at reference sign 912), which received in the step 304, the UE 100 starts to perform 306 serving-cell measurement in fl (at reference sign 912). The measurement can be an OD-SSB based L3 measurement or an OD-SSB based LI measurement.

[0332] The indication can also be based on the mobility command from NW, e.g., handover / conditional handover, the measurement for mobility conducted by UE is based on OD-SSB or AO-SSB.

[0333] Alternatively or in addition, the control message may be indicative of intrafrequency measurements, i.e. a signaling-based intra-frequency indication.

[0334] When NW indicates the OD-SSB transmission, NW can also indicate which frequency is believed as the intra-frequency for the serving cell, either OD-SSB frequency or AO-SSB frequency.

[0335] If there is no explicit indication, by default, the AO-SSB frequency can be believed as intra-frequency. Alternatively, if there is no explicit indication, by default, the OD-SSB frequency can be believed as intra-frequency.

[0336] Such indication can be explicitly based on NW signaling, such as OD-SSB indication or any implicit indication, such as measurement configuration, serving cell measurement object etc.

[0337] For example, if serving-cell measurement object indicates the SSB frequency as AO-SSB, it means AO-SSB will be believed or treated as intra-frequency.

[0338] Alternatively, if serving cell measurement object indicates the SSB frequency as OD-SSB, it means OD-SSB will be believed as intra-frequency.

[0339] For example, the UE 100 shall perform serving cell measurement and neighbor cell measurement with OD-SSB or / and AO-SSB based on the following rules.

[0340] a. In one embodiment, UE performs neighbor cell measurement on AO-SSB frequency if NW indicates AO-SSB as the intra-frequency. UE performs serving cell measurement on OD-SSB frequency.

[0341] b. In another embodiment, UE performs intra-frequency serving and neighbor cell measurement on both AO-SSB and OD-SSB frequencies. Both AO-SSB and OD-SSB frequencies are counted as intra-frequency.c. In another embodiment, UE performs both serving cell and neighbor cell measurement on OD-SSB frequency if NW indicates OD-SSB as the intra- frequency. UE drops / skips / suspends the measurement on AO-SSB.

[0342] UE switches to apply AO-SSB as intra-frequency if OD-SSB isn't able to be measured by UE, such as OD-SSB is deactivated by NW indication or OD-SSB transmission timer is expired.

[0343] In another example, both OD-SSB frequency and AO-SB frequency are configured as intra-frequency. For example, configured both frequency in serving cell MO. UE performs the neighbor cell measurement in intra-frequency in both AO-SSB and OD-SSB frequency.

[0344] Alternatively, UE performs the neighbor cell measurement in intra-frequency in any SSB frequency based on NW indication.

[0345] In another embodiment, a new field parameter is introduced in MeasObjectNR IE, same as or similar to the legacy field parameter, freqBandlndicatorNR. to indicate the frequency band in which the SSB and / or CSI-RS indicated in this MeasObjectNR IE are located. This new parameter is intended for indicating the frequency band for OD-SSB transmission if the indication for the AO-SSB frequency is provided in the legacy field parameter, i.e., freqBandlndicatorNR, or vice versa.

[0346] In another embodiment, a flag is introduced in the MeasObjectNR IE, instead of the field parameter freqBandlndicatorNR. to indicate that there are additional SSB transmission to support serving cell measurements in the serving cell.

[0347] Alternatively or in addition, in a variant of any embodiments, the configuration message or the control message may be indicative of rules, i.e. a rules-based intra- frequency indication.

[0348] When NW configures OD-SSB as the different frequency as AO-SSB, some pre¬ defined rules can be defined to indicate which frequency as intra-frequency. The rules can be as follow.

[0349] a. The OD-SSB frequency is believed as intra-frequency and the AO-SSB frequency is believed as inter-frequency once NW indicates the OD-SSB transmission.

[0350] UE performs the neighbor-cell measurement in intra-frequency with OD-SSB.UE performs the L3 inter-frequency measurement for AO-SSB frequency with gap if the AO-SSB frequency is outside the active BWP; otherwise, UE performs the L3 inter-frequency measurement for AO-SSB frequency without gap.

[0351] b. The AO-SSB frequency is intra-frequency and the OD-SSB frequency is inter¬ frequency once NW indicates the OD-SSB transmission.

[0352] c. Both OD-SSB frequency and AO-SB frequency are considered as intra- frequency.

[0353] UE 100 performs the neighbor cell measurement 306 in intra-frequency in (i.e., w.r.t) AO-SSB frequency.

[0354] UE performs serving cell measurement in OD-SSB frequency if NW indicates OD- SSB transmission.

[0355] UE performs the neighbor cell measurement in intra-frequency in both AO-SSB and OD-SSB frequency.

[0356] UE performs the neighbor cell measurement in intra-frequency in any SSB frequency based on NW indication.

[0357] Any embodiment of the methods 300 and 400 may comprise (e.g., in FR2) receiver (Rx) beam sweeping

[0358] When the NW 200 indicates the OD-SSB transmission in the steps 402 and 302, the UE 100 shall assume OD-SSB is QCL Type-D with AO-SSB. Alternatively, when NW indicates the OD-SSB transmission, such QCL information between OD-SSB and AO-SSB can be configured by NW, such as by TCI state.

[0359] In one embodiment, UE performs fast measurement for serving cell without Rx beam sweeping in OD-SSB frequency if OD-SSB is QCL'ed Type-D (i.e., QCL information is used) with AO-SSB. The prior Tx-Rx beam pair relation can be measured by AO-SSB before OD-SSB indication. The measured best SSB beam index can be reported by UE.

[0360] In one embodiment, UE prioritize the fast measurement for OD-SSB frequency and suspend / extend the measurement for AO-SSB frequency. The neighbor cell measurement in AO-SSB frequency can be restarted after UE finishing the OD-SSB fast measurement in OD-SSB frequency.In another embodiment, UE performs neighbor cell measurement with Rx beam sweeping in AO-SSB frequency at the same time as serving cell measurement in OD-SSB frequency.

[0361] Herein, when referring to Release 19 Network Energy Saving, an energy improvement may be calculated or estimated at the network level.

[0362] Fig. 10 shows a schematic block diagram for an embodiment of the device 100. The device 100 comprises processing circuitry, e.g., one or more processors 1004 for performing the method 300 and memory 1006 coupled to the processors 1004. For example, the memory 1006 may be encoded with instructions that implement at least one of the modules 104 and 106.

[0363] The one or more processors 1004 may be a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, microcode and / or encoded logic operable to provide, either alone or in conjunction with other components of the device 100, such as the memory 1006, radio device functionality. For example, the one or more processors 1004 may execute instructions stored in the memory 1006. Such functionality may include providing various features and steps discussed herein, including any of the benefits disclosed herein. The expression "the device being operative to perform an action" may denote the device 100 being configured to perform the action.

[0364] As schematically illustrated in Fig. 10, the device 100 may be embodied by a radio device 1000, e.g., functioning as a UE. The radio device 1000 comprises a radio interface 1002 coupled to the device 100 for radio communication with one or more network nodes, e.g., functioning as base stations or relay UE.

[0365] Fig. 11 shows a schematic block diagram for an embodiment of the device 200. The device 200 comprises processing circuitry, e.g., one or more processors 1104 for performing the method 400 and memory 1106 coupled to the processors 1104. For example, the memory 1106 may be encoded with instructions that implement at least one of the modules 202 and 206.

[0366] The one or more processors 1104 may be a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signalprocessor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, microcode and / or encoded logic operable to provide, either alone or in conjunction with other components of the device 200, such as the memory 1106, network node functionality. For example, the one or more processors 1104 may execute instructions stored in the memory 1106. Such functionality may include providing various features and steps discussed herein, including any of the benefits disclosed herein. The expression "the device being operative to perform an action" may denote the device 200 being configured to perform the action.

[0367] As schematically illustrated in Fig. 11, the device 200 may be embodied by a network node 1100, e.g., functioning as a gNB base station. The network node 1100 comprises a radio interface 1102 coupled to the device 200 for radio communication with one or more radio devices, e.g., functioning as a UE.

[0368] With reference to Fig. 12, in accordance with an embodiment, a communication system 1200 includes a telecommunication network 1210, such as a 3GPP-type cellular network, which comprises an access network 1211, such as a radio access network, and a core network 1214. The access network 1211 comprises a plurality of base stations 1212a, 1212b, 1212c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 1213a, 1213b, 1213c. Each base station 1212a, 1212b, 1212c is connectable to the core network 1214 over a wired or wireless connection 1215. A first user equipment (UE) 1291 located in coverage area 1213c is configured to wirelessly connect to, or be paged by, the corresponding base station 1212c. A second UE 1292 in coverage area 1213a is wirelessly connectable to the corresponding base station 1212a. While a plurality of UEs 1291, 1292 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station 1212.

[0369] Any of the base stations 1212 and the UEs 1291, 1292 may embody the device 200 and 100, respectively.

[0370] The telecommunication network 1210 is itself connected to a host computer 1230, which may be embodied in the hardware and / or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. The host computer 1230 may be under the ownership or control of aservice provider, or may be operated by the service provider or on behalf of the service provider. The connections 1221, 1222 between the telecommunication network 1210 and the host computer 1230 may extend directly from the core network 1214 to the host computer 1230 or may go via an optional intermediate network 1220. The intermediate network 1220 may be one of, or a combination of more than one of, a public, private or hosted network; the intermediate network 1220, if any, may be a backbone network or the Internet; in particular, the intermediate network 1220 may comprise two or more sub-networks (not shown).

[0371] The communication system 1200 of Fig. 12 as a whole enables connectivity between one of the connected UEs 1291, 1292 and the host computer 1230. The connectivity may be described as an over-the-top (OTT) connection 1250. The host computer 1230 and the connected UEs 1291, 1292 are configured to communicate data and / or signaling via the OTT connection 1250, using the access network 1211, the core network 1214, any intermediate network 1220 and possible further infrastructure (not shown) as intermediaries. The OTT connection 1250 may be transparent in the sense that the participating communication devices through which the OTT connection 1250 passes are unaware of routing of uplink and downlink communications. For example, a base station 1212 need not be informed about the past routing of an incoming downlink communication with data originating from a host computer 1230 to be forwarded (e.g., handed over) to a connected UE 1291. Similarly, the base station 1212 need not be aware of the future routing of an outgoing uplink communication originating from the UE 1291 towards the host computer 1230.

[0372] By virtue of the method 200 being performed by any one of the UEs 1291 or 1292 and / or any one of the base stations 1212, the performance or range of the OTT connection 1250 can be improved, e.g., in terms of increased throughput and / or reduced latency. More specifically, the host computer 1230 may indicate to the RAN 500 or the radio device 100 or the network node 200 (e.g., on an application layer) the QoS of the traffic. The QoS may in turn trigger usage of the OD-SSB according to an embodiment of the methods 300 and 400.

[0373] As has become apparent from above description, at least some embodiments of the technique enable a radio device (e.g., UE) understand, e.g. based on the control message or any other indication from the network, how to perform measurement when the network (NW, e.g. a RAN, particularly its serving network node) configures both always-on SSB and on-demand SSB transmissions.Same or further embodiments are beneficial for both the NW (e.g., the network node) and the radio device (e.g., UE) to reduce better power consumption to only monitor OD-SSB in a short time period. By way of example, the radio device may use QCL information (e.g., of the AO-SBB reception) to speed up measuring 306 on the OD-SSB (e.g., an OD-SSB frequency serving cell measurement), e.g., by skipping an Rx beam sweeping.

[0374] Reference signs

[0375] Radio device, e.g. UE 100; 1000; 1291; 1292 Network node, e.g. gNB 200; 1100; 1212

[0376] Radio access network (RAN) 500

[0377] Method performed by a radio device 300

[0378] Receiving a configuration message 302

[0379] (e.g., at the radio device)

[0380] Receiving a control message 304

[0381] (e.g., at the radio device)

[0382] Measuring SSB 306

[0383] (e.g., at the radio device)

[0384] Transmitting a measurement report 308

[0385] (e.g., at the radio device)

[0386] Method performed by a network node 400

[0387] Transmitting a configuration message 402

[0388] (e.g., by the RRC layer of the network node)

[0389] Transmitting a control message 404

[0390] (e.g., by the MAC or PHY layer of the network node)

[0391] Receiving a measurement report 408

[0392] (e.g., at the network node)

[0393] Synchronization Signal Block (SSB) 901; 902

[0394] Always-on synchronization signal block (AO-SSB) 901

[0395] On-demand synchronization signal block (OD-SSB) 902

[0396] AO-SSB frequency resource, e.g. center frequency 911

[0397] OD-SSB frequency resource, e.g. center frequency 912

[0398] Bandwidth part (BWP) or carrier bandwidth 920

[0399] Serving cell 601; 602

[0400] Primary cell (PCell) 601

[0401] Secondary cell (SCell), e.g. PSCell 602Control Message Reception Module 104

[0402] (e.g., in radio device)

[0403] SSB Measurement Module 106

[0404] (e.g., in radio device)

[0405] Control Message Transmission Module 204

[0406] (e.g., in network node)

[0407] Measurement Reception Module 208

[0408] (e.g., in network node)

[0409] Radio interface 1002 1102

[0410] Processing circuitry, 1004, 1104

[0411] e.g. computing device or Processor

[0412] Memory, 1006, 1106

[0413] e.g. computer-readable recording medium

[0414] Many advantages of the present invention will be fully understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the units and devices without departing from the scope of the invention and / or without sacrificing all of its advantages. Since the invention can be varied in many ways, it will be recognized that the invention should be limited only by the scope of the following claims.

Claims

Claims1. A method (300) performed by a radio device (100; 1000; 1291; 1292) in communication with a radio access network, RAN (500), the method (300) comprising:receiving (304), from a network node (200; 1100; 1212) of the RAN (500), a control message that is indicative of measuring at least one of always-on synchronization signal blocks, AO-SSB (901 ), on an AO-SSB frequency resource (911 ) and on-demand synchronization signal blocks, OD-SSB (902), on an OD-SSB frequency resource (912); andmeasuring (306) on at least one of the AO-SSB frequency resource (911 ) and the OD-SSB frequency resource (912) in response to the received (304) control message.

2. The method (300) of claim 1, further comprising:receiving (302), from the network node (200; 1100; 1212) of the RAN (500), a configuration message that is indicative of a configuration of the radio device (100; 1000; 1291; 1292) for at least one of the AO-SSB (901 ) and the OD-SSB (902).

3. The method (300) of claim 1 or 2, wherein at least one of the configuration message and the control message is indicative of the OD-SSB frequency resource (912) of the OD-SSB (902); and / orwherein at least one of the configuration message and the control message is indicative of the AO-SSB (901 ) frequency resource of the AO-SSB (901 ).

4. The method (300) of any one of claims 1 to 3, wherein the received (304) control message, optionally a flag comprised in the control message, is indicative of one ofwhether or not the radio device (100; 1000; 1291; 1292) shall measure (306) the AO-SSB (901);whether or not the radio device (100; 1000; 1291; 1292) shall measure (306) the OD-SSB (902);whether the radio device (100; 1000; 1291; 1292) shall measure (306) either the AO-SSB (901 ) or the OD-SSB (902); andthat the radio device (100; 1000; 1291; 1292) shall measure (306) both the AO-SSB (901 ) and the OD-SSB (902).

5. The method (300) of any one of claims 1 to 4,wherein the measuring (306) is a serving-cell measurement of a serving cell (601; 602) serving the radio device (100; 1000; 1291; 1292).

6. The method (300) of any one of claims 1 to 5, further comprising: reverting to measuring a or the AO-SSB (901 ) on an or the AO-SSB frequency resource (911 ), optionally a default frequency not indicated by the control message, if the received (304) control message is indicative of transmissions of the OD-SSB (902) being deactivated and / or if an on-demand timer at the radio device (100; 1000; 1291; 1292) has expired.

7. The method (300) of any one of claims 1 to 6, further comprising:if the received (304) control message is indicative of a deactivation of the OD-SSB (902) and / or in the absence of an explicit activation of the OD-SSB (902), treating an or the AO-SSB frequency resource (911 ) as primary intra-frequency resource and / or performing the measurement (306) on an or the AO-SSB frequency resource (911); and / orskipping OD-SSB measurements in the measurement (306) unless a specific activation is received (304) in the control message.

8. The method (300) of any one of claims 1 to 7, further comprising:transmitting (308) a measurement report to the network node (200; 1100; 1212) based on and / or upon completion of the measurement (306) of the OD-SSB (902) and / or the AO-SSB (901 ), optionally the measurement report enabling the network node (200; 1100; 1212) to adjust or deactivate OD-SSB transmissions based on the reported result of the measurement (306).

9. The method (300) of claim 8, wherein the control message comprises an updated control, or the method further comprising receiving, from the network node (200; 1100; 1212), an updated control, that OD-SSB transmissions are deactivated or reconfigured, and in response, updating the measuring (306) to exclude OD-SSB (902) or modify OD-SSB scanning periodicity.

10. The method (300) of any one of claims 1 to 9, wherein the control message or the configuration message configures a measurement object of the OD-SSB (902) and / or a measurement object of the AO-SSB (901 ) in the radio device (100; 1000; 1291; 1292), and / orwherein each measurement object in the control message or the configuration message defines whether a frequency resource of the respective measurement object is treated as intra-frequency resource or inter-frequency resource, and / or wherein each measurement object in the control message or the configuration message defines whether the measurement (306) of the respective measurement object is an intra-frequency measurement (306) or an inter-frequency measurement (306).

11. The method (300) of claim 10, wherein the or each measurement object further comprises a field parameter within the measurement object to indicate or distinguish between AO-SSB frequency resource (911 ) and OS-SSB frequency resource (912).

12. The method (300) of any one of claims 1 to 11, wherein the AO-SSB (901 ) and / or the OD-SSB (902) are received in the same cell (601; 602) served by the network node (200; 1100; 1212), and / orwherein a cell (601; 602) of the AO-SSB (901 ) and / or the OD-SSB (902) is a primary cell, PCell (601 ), or a secondary cell, SCell (602), serving the radio device (100; 1000; 1291; 1292) in a carrier aggregation, CA, and / orwherein the network node (200; 1100; 1212) is a master node, MN, and a cell (601; 602) of the AO-SSB (901 ) and / or the OD-SSB (902) is an SCell (602) of the MN (200; 1100; 1212) or wherein the network node (200; 1100; 1212) is a secondary node, SN, and a cell (601; 602) of the AO-SSB (901 ) and / or the OD-SSB (902) is a primary secondary cell, PSCell (602), or an SCell (602) of the SN (200; 1100; 1212) serving the radio device (100; 1000; 1291; 1292) in a dual connectivity, DC, and / or CA.

13. The method (300) of any one of claims 1 to 12, wherein the AO-SSB frequency resource (911 ) and the OD-SSB frequency resource (912) are different; and / or wherein the AO-SSB frequency resource (911 ) and the OD-SSB frequency resource (912) are in the same bandwidth part, BWP (920), or in-band.

14. The method (300) of any one of claims 1 to 13, wherein the network node indicates which frequency is believed as the intra-frequency for the serving cell, either OD-SSB frequency or AO-SSB frequency or both frequencies.

15. The method (300) of claim 14, wherein such indication is explicitly based on NW signaling, such as OD-SSB indication, Measurement Objects configuration, or servingCellMO configuration.

16. The method (300) of any one of claims 1 to 15, further comprising, upon receiving (304) the control message, treating the indicated OD-SSB frequency resource (912) as an intra-frequency resource; and / orwherein the measurement (306) on the OD-SSB frequency resource (912) is an intra-frequency measurement; and / orwherein the measurement (306) on the OD-SSB frequency resource (912) is an intra-BWP measurement; and / orwherein the measurement (306) on the OD-SSB frequency resource (912) requires no dedicated measurement gap.

17. The method (300) of any one of claims 1 to 16, wherein the measuring (306) is a neighbor-cell measurement on the OD-SSB frequency resource (912), optionally as an intra-frequency measurement and / or avoiding dedicated measurement gaps for the neighbor-cell measurement.

18. The method (300) of any one of claims 1 to 17, further comprising:when both the AO-SSB frequency resource (911 ) and the OD-SSB frequency resource (912) are simultaneously configured (302; 304) within the same carrier bandwidth (920) and / or activated for measurement (306), performing the measurements (306) for each of the AO-SSB frequency resource (911 ) and the OD-SSB frequency resource (912) as intra-frequency measurements (306).

19. The method (300) of any one of claims 1 to 18, further comprising, in a high-frequency or frequency range 2, FR2, deployment of a serving cell (601; 602) of the network node (200; 1100; 1212) serving the radio device (100; 1000; 1291; 1292), applying a quasi co-location, QCL, between the AO-SSB (901 ) and the OD-SSB (902) in the measuring (306), optionally so as to carry out OD-SSB (902) serving-cell measurements without receive beam sweeping.

20. The method (300) of any one of claims 1 to 19, further comprising receiving (304), optionally in the control message, a mobility command from the network node (200; 1100; 1212) specifying that the measuring (306) by the radio device (100; 1000; 1291; 1292) comprises handover-related measurements (306) on the OD-SSB frequency resource (912), the AO-SSB frequency resource (911 ), or both.

21. The method (300) of any one of claims 1 to 20, wherein the measuring (306) comprising, upon receiving (304), optionally in the control message, an indication that measuring the OD-SSB (902) is prioritized for mobility, skipping neighbor-cell measurements on an or the AO-SSB (901 ), optionally for a predefined time interval.

22. The method (300) of any one of claims 1 to 21, further comprising:applying separate or combined beam management procedures to OD-SSB (902) and AO-SSB (901) based on quasi co-location, QCI, or transmission configuration information, TCI, received (302; 304) from the network node (200; 1100; 1212), optionally in the control message or the configuration message.

23. A method (400) performed by a network node (200; 1100; 1212) of a radio access network, RAN (500), the method (400) comprising:transmitting (404), to a radio device (100; 1000; 1291; 1292), a control message that is indicative of measuring at least one of always-on synchronization signal blocks, AO-SSB (901 ), on an AO-SSB frequency resource (911 ) and on-demand synchronization signal blocks, OD-SSB (902), on an OD-SSB frequency resource (912); andreceiving (408), from the radio device (100; 1000; 1291; 1292), a measurement report that is indicative of results of measuring on at least one of the AO-SSB frequency resource (911 ) and the OD-SSB frequency resource (912).

24. The method (400) of claim 23, further comprising the features and steps according to any one of claims 2 to 22, or corresponding features and steps applied mutatis mutandis according to any one of claims 2 to 22.

25. A computer program product comprising program code portions for performingthe steps of any one of the claims 1 to 22 or23 to 24 when the computer program product is executed on one or more computing devices (1004; 1104), optionally stored on a computer-readable recording medium (1006; 1106).

26. A radio device (100; 1000; 1291; 1292) comprising memory operable to store instructions and processing circuitry operable to execute the instructions, such that the radio device (100; 1000; 1291; 1292) is operable to:receive, from a network node (200; 1100; 1212), a control message that is indicative of measuring at least one of always-on synchronization signal blocks, AO-SSB (901), on an AO-SSB frequency resource (911) and on-demand synchronization signal blocks, OD-SSB (902), on an OD-SSB frequency resource (912); and measure on at least one of the AO-SSB frequency resource (911 ) and the OD-SSB frequency resource (912) in response to the received control message.

27. The radio device (100; 1000; 1291; 1292) of claim 26, further operable to perform the steps of any one of claims 2 to 22.

28. A radio device (100; 1000; 1291; 1292), configured to:receive, from a network node (200; 1100; 1212), a control message that is indicative of measuring at least one of always-on synchronization signal blocks, AO-SSB (901), on an AO-SSB frequency resource (911) and on-demand synchronization signal blocks, OD-SSB (902), on an OD-SSB frequency resource (912); and measure on at least one of the AO-SSB frequency resource (911 ) and the OD-SSB frequency resource (912) in response to the received control message.

29. The radio device (100; 1000; 1291; 1292) of claim 28, further configured to perform the steps of any one of claims 2 to 22.

30. A network node (200; 1100; 1212) comprising memory operable to store instructions and processing circuitry operable to execute the instructions, such that the network node (200; 1100; 1212) is operable to:transmit, to a radio device (100; 1000; 1291; 1292), a control message that is indicative of measuring at least one of always-on synchronization signal blocks, AO-SSB (901), on an AO-SSB frequency resource (911) and on-demand synchronization signal blocks, OD-SSB (902), on an OD-SSB frequency resource (912); and receive, from the radio device (100; 1000; 1291; 1292), a measurement report that is indicative of results of measuring on at least one of the AO-SSB frequency resource (911 ) and the OD-SSB frequency resource (912).

31. The network node (200; 1100; 1212) of claim 30, further operable to perform any one of the steps of claim 24.

32. A network node (200; 1100; 1212), configured to:transmit, to a radio device (100; 1000; 1291; 1292), a control message that is indicative of measuring at least one of always-on synchronization signal blocks, AO-SSB (901), on an AO-SSB frequency resource (911) and on-demand synchronization signal blocks, OD-SSB (902), on an OD-SSB frequency resource (912); and receive, from the radio device (100; 1000; 1291; 1292), a measurement report that is indicative of results of measuring on at least one of the AO-SSB frequency resource (911 ) and the OD-SSB frequency resource (912).

33. The network node (200; 1100; 1212) of claim 32, further configured to perform the steps of claim 24.

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