Selecting beams to include in user equipment event-triggered layer-1 measurement report

Abstract

Embodiments include methods for a user equipment (UE) configured for mobility between cells in a radio access network (RAN) Such methods include performing lower layer measurements on a plurality of beams associated with one or more mobility candidate cells, and determining that the lower layer measurements of a first subset of the plurality of beams fulfill one or more conditions that trigger measurement reporting. Such methods include selecting a second subset of the plurality of beams whose lower layer measurements do not fulfill the one or more conditions that trigger measurement reporting. Each beam of the second subset is selected based on one or more of various conditions, described herein. Such methods include sending, to a RAN node, a measurement report comprising measurement values for the first subset of beams and measurement values for the second subset of beams. Other embodiments include UEs configured to perform such methods.

Description

[0001] SELECTING BEAMS TO INCLUDE IN USER EQUIPMENT EVENT- TRIGGERED LAYER-1 MEASUREMENT REPORT TECHNICAL FIELD

[0002] The present disclosure relates generally to wireless networks and more specifically to mobility of user equipment (UEs) between cells in a radio access network (RAN), even more specifically in relation to UE reporting of measurements that facilitate such mobility.

[0003] BACKGROUND

[0004] The fifth generation (5G) of cellular systems was standardized within the Third-Generation Partnership Project (3GPP). 5G was developed for maximum flexibility to support various use cases including enhanced mobile broadband (eMBB), machine type communications (MTC), ultra-reliable low latency communications (URLLC), side-link device-to-device (D2D), and several others 5G was initially specified in Release 15 (Rel-15) and continues to evolve through subsequent releases.

[0005] Figure 1 illustrates a high-level view of an exemplary 5G network architecture, consisting of a Next Generation Radio Access Network (NG-RAN, 199) and a 5G Core (5GC, 198). The NG-RAN can include one or more gNodeB’s (gNBs) connected to the 5GC via one or more NG interfaces, such as gNBs (100, 150) connected via respective interfaces (102, 152). More specifically, the gNBs can be connected to one or more Access and Mobility Management Functions (AMFs) in the 5GC via respective NG-C interfaces and to one or more User Plane Functions (UPFs) in 5GC via respective NG-U interfaces. The 5GC can include various other network functions (NFs), such as Session Management Function(s) (SMF).

[0006] In addition, the gNBs can be connected to each other via one or more Xn interfaces, such as Xn interface (140) between gNBs (100, 150). The radio technology for the NG-RAN is often referred to as “New Radio” (NR). With respect to the NR interface to UEs, each of the gNBs can support frequency division duplexing (FDD), time division duplexing (TDD), or a combination thereof. Each of the gNBs can serve a geographic coverage area including one or more cells and, in some cases, can also use various directional beams to provide coverage in the respective cells.

[0007] NG RAN logical nodes (e.g., gNB 100) include a Central Unit (CU or gNB-CU, e.g., 110) and one or more Distributed Units (DU or gNB-DU, e.g., 120, 130). CUs are logical nodes that host higher-layer protocols and perform various gNB functions such controlling the operation of DUs. DUs are decentralized logical nodes that host lower layer protocols and can include, depending on the functional split option, various subsets of the gNB functions. Each CU and DU can include various circuitry needed to perform their respective functions, including processing circuitry, communication interface circuitry (e.g., transceivers), and power supply circuitry. AgNB-CU connects to one or more gNB-DUs over respective Fl logical interfaces (e.g., 122 and 132 shown in Figure 1).

[0008] Seamless mobility is a key feature of 3GPP radio access technologies (RATs). In general, a RAN (e.g., NG-RAN) configures a UE to perform and report radio resource management (RRM) measurements to assist network-controlled mobility decisions, such as for handover from a serving cell to a neighbor cell. Seamless handovers ensure that the UE moves around in the coverage area of different cells without excessive interruption to data transmission.

[0009] Conventional inter-cell mobility is triggered by layer 3 (L3) measurements and involves radio resource control (RRC) signaling to change primary cells as well as to release / add secondary cells as needed. Moreover, conventional inter-cell mobility involves complete layer 2 (L2) and layer 1 (LI) resets, leading to longer latency, increased signaling overhead, and longer interruptions than for intra-cell beam switching.

[0010] 3GPP Rel-18 includes new mobility procedures that facilitate serving cell changes via L1 / L2 signaling to address these problems and / or difficulties. These new procedures are often referred to as L1 / L2 based inter-cell mobility or L1 / L2 triggered mobility (LTM). In LTM, a UE is pre-configured by its serving RAN node with one RRC configuration per LTM candidate cell, sometimes referred to as an “LTM candidate cell configuration.” The serving RAN node may also send the UE L1 / L2 messages that trigger early UL and DL synchronization by the UE with each of the configured LTM candidate cells.

[0011] The UE performs measurements on configured LTM candidate cells (and beams of those cells) and transmits corresponding measurement reports to the RAN node, based on which the RAN node triggers execution of an LTM cell switch procedure by the UE to one of the configured LTM candidate cells (and a beam of that cell). The RAN node may trigger the LTM cell switch by sending the UE an LTM cell switch command, including an identifier of an earlier-activated “TCI state” that the UE should use after LTM cell switch. This TCI state may correspond to a beam in the LTM candidate cell. If the UE previously performed early UL synchronization with the LTM candidate cell, the UE may transmit directly in the LTM candidate cell during LTM cell switch without performing a random access (RA) procedure.

[0012] 3GPP Rel-19 will include measurement-related enhancements for LTM. One of these enhancements is called “event-triggered LI reporting” and is intended to address various Rel-18 LTM issues such as excessive UE energy consumption caused by performing and reporting LI measurements for LTM.SUMMARY

[0013] According to a 3GPP agreement for Rel-19, when an LI event (e.g., involving a beam) that triggers a UE LI measurement report is fulfilled, the serving RAN node can control whether measurements for other beams that have not fulfilled any LI events should be included in the LI measurement report. However, the details for this have not been specified or discussed. Furthermore, it is unclear how the UE chooses (e.g., which criteria to use) the beams for which LI measurements are included in the event-triggered LI measurement report. If the UE does not include all beam measurements that are relevant for the serving RAN node’s LTM decisions, the UE may experience delays and / or failures in LTM cell switching. On the other hand, including many beam measurements will increase signaling overhead and UE energy consumption.

[0014] An object of embodiments of the present disclosure is to improve UE selection of a relevant subset of available LI (or beam) measurements in an LI measurement report, such as by providing, enabling, and / or facilitating solutions to exemplary problems summarized above and described in more detail below.

[0015] Embodiments include methods (e.g., procedures) for a UE configured for mobility between cells in a radio access network (RAN, e.g., E-UTRAN, NG-RAN).

[0016] These exemplary methods include performing lower layer measurements on a plurality of beams associated with one or more mobility candidate cells. These exemplary methods also include determining that the lower layer measurements of a first subset of the plurality of beams fulfill one or more conditions that trigger measurement reporting. These exemplary methods also include selecting a second subset of the plurality of beams whose lower layer measurements do not fulfill the one or more conditions that trigger measurement reporting. These exemplary methods also include sending, to a RAN node that provides a serving cell for the UE, a measurement report comprising measurement values for the first subset of beams and measurement values for the second subset of beams.

[0017] In some embodiments, the measurement report further comprises, for each beam in the second subset, an explicit indication that the lower layer measurements for the beam did not fulfill any condition for measurement reporting.

[0018] In some embodiments, the second subset of beams is selected further based on a size of the reported measurement values for the first subset being less than an allocated resource capacity for the measurement report. In some of these embodiments, a number of beams in the second subset is zero when the size of the reported measurement values for the first subset is substantially equal to the allocated resource capacity for the measurement report.

[0019] In some embodiments, a total number of beams in the first and second subsets is less than a maximum number of beams that may be reported. In some embodiments, the measurementvalues for one or more beams of the first subset are at least the threshold value.

[0020] In some embodiments, a total number of beams in the second subset is one of the following: constant, based on how many beams on which the lower layer measurements are performed, or based on how many mobility candidate cells on which the lower layer measurements are performed.

[0021] In some embodiments, one or more beams of the second subset are selected based on being involved in one or more of the following: early uplink synchronization, and early downlink synchronization.

[0022] In some embodiments, the threshold value is for one of the following: reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-interference-and-noise ratio (SINR), and received signal strength (RSSI).

[0023] In some embodiments, these exemplary methods also include performing upper layer measurements on the plurality of beams associated with the one or more mobility candidate cells. One or more beams of the second subset are selected further based on their upper layer measurements fulfilling one or more further conditions that trigger upper layer measurement reporting. In some of these embodiments, the lower layer measurements are LI measurements, and the upper layer measurements are layer-3 (L3) measurements that have been time-filtered.

[0024] In various embodiments, one or more beams of the second subset may be selected further based on various other rules, criteria, and / or conditions, with various examples described herein.

[0025] Other embodiments include UEs (e.g., wireless devices) configured to perform operations corresponding to any of the exemplary methods described herein. Other embodiments include non-transitory, computer-readable media storing program instructions that, when executed by processing circuitry, configure such UEs to perform operations corresponding to any of the exemplary methods described herein.

[0026] These and other embodiments described herein may provide various advantages and / or benefits. For example, embodiments may enable a UE to include in an event-triggered LI measurement report beams whose measurements are relevant and / or usable by the serving RAN node to make informed and / or optimal mobility decisions for the UE. Furthermore, embodiments enable the UE to avoid including beams that are not relevant and / or not usable by the serving RAN node for mobility decisions, thereby reducing signaling overhead and UE energy consumption. By avoiding over- or under-inclusiveness of beams in event-triggered LI measurement reports, embodiments facilitate timely mobility decisions by the serving RAN node, thereby reducing HO failures, RLFs, cell switch latency, and connection interruptions.These and other objects, features, and advantages of embodiments of the present disclosure will become apparent upon reading the following Detailed Description in view of the Drawings briefly described below.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 shows a high-level view of an exemplary 5G / NR network architecture.

[0029] Figure 2 shows exemplary NR user plane (UP) and control plane (CP) protocol stacks. Figure 3 shows an ASN.l data structure for an exemplary radio resource control (RRC) TCI-State information element (IE).

[0030] Figure 4 shows an exemplary TCI state activation MAC CE.

[0031] Figure 5 shows a signaling diagram for an exemplary LTM cell switch procedure.

[0032] Figure 6 shows an exemplary RRC LTM-CSI-SSB-Re sourceSet information element (IE). Figure 7 shows a flow diagram of an exemplary method for a UE (e.g., wireless device), according to various embodiments of the present disclosure.

[0033] Figure 8 shows a communication system according to various embodiments of the present disclosure.

[0034] Figure 9 shows a UE according to various embodiments of the present disclosure.

[0035] DETAILED DESCRIPTION

[0036] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein, the disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided as examples to convey the scope of the subject matter to those skilled in the art.

[0037] In general, all terms used herein are to be interpreted according to their ordinary meaning to a person of ordinary skill in the relevant technical field, unless a different meaning is expressly defined and / or implied from the context of use. All references to a / an / the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise or clearly implied from the context of use. The operations of any methods and / or procedures disclosed herein do not have to be performed in the exact order disclosed, unless an operation is explicitly described as following or preceding another operation and / or where it is implicit that an operation must follow or precede another operation. Any feature of any embodiment disclosed herein can apply to any other disclosed embodiments, as appropriate. Likewise, any advantage of any embodiment described herein can apply to any other disclosed embodiments, as appropriate.

[0038] Furthermore, the following terms are used throughout the description given below:• Radio Access Node: As used herein, a “radio access node” (or equivalently “radio network node,” “radio access network node,” or “RAN node”) can be any node in a radio access network (RAN) that operates to wirelessly transmit and / or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., gNB in a 3GPP 5G / NR network or an enhanced or eNB in a 3GPP LTE network), base station distributed components (e.g., CU and DU), a high-power or macro base station, a low-power base station (e.g., micro, pico, femto, or home base station, or the like), an integrated access backhaul (IAB) node, a transmission point (TP), a transmission reception point (TRP), a remote radio unit (RRU or RRH), and a relay node.

[0039] • Core Network Node: As used herein, a “core network node” is any type of node in a core network. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a serving gateway (SGW), a PDN Gateway (P-GW), a Policy and Charging Rules Function (PCRF), an access and mobility management function (AMF), a session management function (SMF), a user plane function (UPF), a Charging Function (CHF), a Policy Control Function (PCF), an Authentication Server Function (AUSF), a location management function (LMF), or the like.

[0040] • Wireless Device: As used herein, a “wireless device” (or “WD” for short) is any type of device that is capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other wireless devices. Communicating wirelessly can involve transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information through air. Unless otherwise noted, the term “wireless device” is used interchangeably herein with the term “user equipment” (or “UE” for short), with both of these terms having a different meaning than the term “network node”.

[0041] • Radio Node: As used herein, a “radio node” can be either a “radio access node” (or equivalent term) or a “wireless device.”

[0042] • Network Node: As used herein, a “network node” is any node that is either part of the radio access network (e.g., a radio access node or equivalent term) or of the core network (e.g., a core network node discussed above) of a cellular communications network. Functionally, a network node is equipment capable, configured, arranged, and / or operable to communicate directly or indirectly with a wireless device and / or with other network nodes or equipment in the cellular communications network, to enable and / or provide wireless access to the wireless device, and / or to perform other functions (e.g., administration) in the cellular communications network.• Node: As used herein, the term “node” (without prefix) can be any type of node that can in or with a wireless network (including RAN and / or core network), including a radio access node (or equivalent term), core network node, or wireless device. However, the term “node” may be limited to a particular type (e.g., radio access node, IAB node) based on its specific characteristics in any given context.

[0043] The above definitions are not meant to be exclusive. In other words, various ones of the above terms may be explained and / or described elsewhere in the present disclosure using the same or similar terminology. Nevertheless, to the extent that such other explanations and / or descriptions conflict with the above definitions, the above definitions should control.

[0044] Note that the description given herein focuses on a 3 GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system and can be applied to any communication system that may benefit from them.

[0045] Figure 2 shows an exemplary configuration of NR user plane (UP) and control plane (CP) protocol stacks between a UE (210), a gNB (220), and an AMF (230). Physical (PHY), Medium Access Control (MAC), Radio Link Control (RLC), and Packet Data Convergence Protocol (PDCP) layers between UE and gNB are common to UP and CP. PDCP provides ciphering / deciphering, integrity protection, sequence numbering, reordering, and duplicate detection for both CP and UP, as well as header compression and retransmission for UP data.

[0046] On the UP side, Internet protocol (IP) packets arrive to PDCP as service data units (SDUs), and PDCP creates protocol data units (PDUs) to deliver to RLC. The Service Data Adaptation Protocol (SDAP) layer handles quality-of-service (QoS) including mapping between QoS flows and Data Radio Bearers (DRBs) and marking QoS flow identifiers (QFI) in UL and DL packets. RLC transfers PDCP PDUs to MAC through logical channels (LCH). RLC provides error detection / correction, concatenation, segmentation / reassembly, sequence numbering, reordering of data transferred to / from the upper layers. MAC provides mapping between LCHs and PHY transport channels, LCH prioritization, multiplexing into or demultiplexing from transport blocks (TBs), hybrid ARQ (HARQ) error correction, and dynamic scheduling (in gNB). PHY provides transport channel services to MAC and handles transfer over the NR radio interface, e.g., via modulation, coding, antenna mapping, and beam forming.

[0047] On the CP side, the non-access stratum (NAS) layer between UE and AMF handles UE / gNB authentication, mobility management, and security control. RRC sits below NAS in the UE but terminates in the gNB rather than the AMF. RRC controls communications between UE and gNB at the radio interface as well as the mobility of a UE between cells in the NG-RAN. RRC also broadcasts system information (SI) and performs establishment, configuration, maintenance,and release of DRBs and Signaling Radio Bearers (SRBs) and used by UEs. Additionally, RRC controls addition, modification, and release of carrier aggregation (CA) and dual -connectivity (DC) configurations for UEs, and performs various security functions such as key management.

[0048] After a UE is powered ON it will be in the RRC IDLE state until an RRC connection is established with the network, at which time the UE will transition to RRC CONNECTED state (e.g., where data transfer can occur). The UE returns to RRC IDLE after the connection with the network is released. In RRC IDLE state, the UE’s radio is active on a discontinuous reception (DRX) schedule configured by upper layers. During DRX active periods (also referred to as “DRX On durations”), an RRC IDLE UE receives SI broadcast in the cell where the UE is camping, performs measurements of neighbor cells to support cell reselection, and monitors a paging channel on PDCCH for pages from 5GC via gNB. An NR UE in RRC IDLE state is not known to the gNB serving the cell where the UE is camping. However, NR RRC includes an RRC_INACTIVE state in which a UE is known (e.g., via UE context) by the serving gNB. RRC INACTIVE has some properties similar to a “suspended” condition used in LTE.

[0049] A gNB can also use various directional beams to provide coverage in the respective cells served by the gNB. In general, a downlink (DL) beam is a coverage area of a network-transmitted reference signal (RS) that may be measured or monitored by a UE. Two DL RS have a quasicolocation (QCL) relation when the respective gNB antenna ports on which they are transmitted are configured such that properties of a channel over which the RS on one antenna port is conveyed can be inferred from the channel over which a RS on the other antenna port is conveyed. Such large-scale properties may include one or more of delay spread, Doppler spread, Doppler shift, average gain, average delay, and spatial Rx parameters. Since the channel is estimated using a RS, two RS may also be referred to as QCL or having a QCL relation.

[0050] The RAN can indicate to a UE that two antenna ports are QCL with respect to a certain parameter. Subsequently, the UE can estimate that parameter based on one of the antenna ports and use that estimate when receiving the other antenna port. In NR, four types of QCL relations between a source RS and target RS may be indicated by a RAN node:

[0051] • Type A: {Doppler shift, Doppler spread, average delay, delay spread}

[0052] • Type B: {Doppler shift, Doppler spread}

[0053] • Type C: {average delay, Doppler shift}

[0054] • Type D: {Spatial Rx parameter}

[0055] QCL type D was introduced to facilitate beam management with analog beamforming and is also known as “spatial QCL”.

[0056] In NR, a RAN node can configure a UE (e.g., via RRC) with multiple transmission configuration indicator (TCI) states, with each TCI state providing QCL information that the UEcan use to receive a target RS. In particular, the TCI state may define a QCL source RS, such that the TCI state itself may be referred to as a QCL source. Figure 3 shows an ASN.l data structure for an exemplary RRC TCI-State information element (IE).

[0057] Once configured, a TCI state can be activated by the RAN node sending the UE a TCI state activation MAC CE. Figure 4 shows an exemplary TCI state activation MAC CE, which is arranged into N octets (i.e., bytes), with N being the number of TCI states being activated. Each activated TCI state is identified by a TCI state ID, which identifies a TCI state previously configured via RRC. The Serving Cell ID field indicates the serving cell for which the MAC CE applies. If the indicated Serving Cell is configured as part of a simultaneous TCI update list, then this MAC CE applies to all serving cells in the list. This may be referred to as “unified TCI state activation.”

[0058] 3 GPP Rel-10 introduced support for channel bandwidths larger than 20 MHz in Fourthgeneration (4G) Long-Term Evolution (LTE) networks. To remain compatible with UEs from earlier releases (e.g., LTE Rel-8), a wideband LTE Rel-10 carrier appears as multiple component carriers (CCs), each having the same structure as an LTE Rel-8 carrier. A Rel-10 UE can receive the multiple CCs based on Carrier Aggregation (CA). The CCs can also be considered “cells,” such that a UE in CA has one primary cell (PCell) and one or more secondary cells (SCells) that are referred to collectively as a “cell group.”

[0059] LTE Rel-12 introduced dual connectivity (DC) whereby a UE can be connected to two network nodes simultaneously, thereby improving connection robustness and / or capacity. 5G / NR also supports various DC (or more generally, multi-connectivity) configurations for UEs. 3 GPP TR 38.804 (vl4.0.0) describes various exemplary DC scenarios or configurations in which the MN and SN can apply NR, LTE, or both. In particular, a UE is configured with a Master Cell Group (MCG) provided by a master node (MN) and a Secondary Cell Group (SCG) provided by a secondary node (SN). Each cell group includes one MAC entity, a set of logical channels with associated RLC entities, a primary cell (i.e., PCell for MCG, PSCell for SCG), and optionally one or more SCells.

[0060] Seamless mobility is a key feature of 3GPP radio access technologies (RATs). When the UE moves between the coverage areas of two cells, a serving cell change needs to be performed at some point. Currently, serving cell change is triggered by L3 (e.g., RSRP) measurements and involves RRC signaling to change PCell and PSCell (e.g., when dual connectivity is configured), as well as release / add SCells (e.g., when CA is configured).

[0061] In general, a RAN (e.g., NG-RAN) configures a UE in RRC_CONNECTED state to perform and report radio resource management (RRM) measurements to assist network-controlled mobility decisions, such as for handover from a serving cell to a target cell (e.g.,PCell change). Upon the reported measurements meeting a certain condition or threshold, the serving RAN node may send a handover command to the UE, indicating a target cell for the handover. In NR, the handover command is an RRCReconfiguration message with a reconfigurationWithSync field. The procedure to perform a handover is sometimes also referred to as “L3 mobility”, as it is controlled by L3 and the RRC messages exchanged are part of L3.

[0062] These reconfigurations are prepared in advance by a target RAN node serving the target cell, upon a request from the UE’s serving RAN node. This request is transmitted over the Xn interface in case the serving and target RAN nodes are part of the NG-RAN. The reconfiguration in the handover command is based on the UE’s existing RRC configuration in its current serving cell (also referred to as “source cell”), which are provided in the inter-node request. In some cases, the reconfiguration can be provided as a “delta” to the UE’s existing configuration in the source cell, which reduces the size of the handover command.

[0063] The reconfiguration provided by the target RAN node contains all information the UE needs to access the target cell, e.g., random access configuration, a new cell radio network temporary identifier (C-RNTI) assigned to the UE in the target cell, and parameters enabling the UE to calculate security keys that it can use when communicating with the target cell (including sending a handover complete message).

[0064] In general, UE nobility in RRC CONNECTED state is network-based since the network has the most information about conditions such as cell loading (UEs and / or traffic), available node resources (e.g., processing), available frequencies, etc. Seamless handovers ensure that the UE moves around in the coverage area of different cells without excessive interruption to data transmission. However, there will be scenarios when the network fails to handover the UE to the “correct” neighbor cell in time, which can cause the UE will declare radio link failure (RLF) or handover failure (HOF).

[0065] To address various difficulties with handovers and other mobility procedures, 3 GPP Rel-16 includes support for conditional handover (CHO) and SN-initiated intra-SN conditional PSCell change (CPC) procedures while Rel-17 includes support for various other conditional mobility procedures. A main principle of conditional mobility is separation of transmission and execution of a mobility (e.g., handover) command. This allows the mobility command to be sent earlier to UE when the radio conditions are still good, thus increasing the likelihood that it is successfully transferred. The execution of the mobility command is done at later point in time based on an associated execution condition.

[0066] Even so, both conditional (e.g., CHO) and non-conditional (e.g., HO) mobility procedures are triggered by L3 measurements and involve RRC signaling to change PCell and PSCell (e.g., when DC is configured), as well as release / add SCells as needed. Moreover,conventional inter-cell mobility involves complete LI (i.e., PHY) and L2 resets, leading to longer latency, increased signaling overhead, and longer interruptions than for intra-cell beam switching.

[0067] 3GPP Rel-18 includes new mobility procedures that facilitate serving cell changes via L1 / L2 signaling to address these problems and / or difficulties. These new procedures are often referred to as L1 / L2 based inter-cell mobility or L1 / L2 triggered mobility (LTM). In LTM, a UE is pre-configured by its serving RAN node with one RRC configuration per LTM candidate cell, sometimes referred to as an “LTM candidate cell configuration.” The UE performs measurements on configured LTM candidate cells and transmits corresponding measurement reports to the RAN node, based on which the RAN node triggers execution of a LTM cell switch procedure by the UE to one of the configured LTM candidate cells. The RAN node may trigger the LTM cell switch procedure by sending the UE an LTM cell switch command.

[0068] In LTM, a UE is pre-configured by its serving RAN with one RRC configuration per LTM candidate cell, sometimes referred to as an “LTM candidate cell configuration.” This RRC configuration may be an RRCReconfiguration message or a portion thereof, such as one or more lEs / fields / parameters (e.g., CellGroupConfig IE). The UE performs measurements on configured LTM candidate cells and transmits corresponding measurement reports to the RAN, which triggers the execution of a LTM cell switch procedure by the UE to one of the configured LTM candidate cells. This triggering is done by transmitting an LTM cell switch command to the UE in lower layer signaling (e.g., DCI or MAC CE). Based on this command, the UE connects to the associated LTM candidate cell and uses the previously received RRC configuration for this cell.

[0069] Regarding terminology, a candidate cell configured for a UE mobility procedure (e.g., LTM or L3) becomes a target cell when the UE performs the mobility procedure, either due to a command from the UE’s current serving RAN node or due to execution conditions being met at the UE. As such, in the context of conditions. As such, the terms “candidate,” “target,” and “candidate (target)” may be used interchangeably when referring to that cell or to the RAN node serving that cell. Likewise, the UE’s serving cell becomes when the UE performs the mobility procedure, and so the terms “source,” “serving,” and “serving (source)” may be used interchangeably when referring to that cell or to the RAN node serving that cell.

[0070] Figure 5 shows signaling for an exemplary LTM cell switch procedure between a UE (510) and a gNB (520). Although the operations are shown with numerical labels, this is done to facilitate explanation rather than to require or imply any specific operational order, unless expressly stated otherwise.

[0071] In operation 1, the UE sends a MeasurementReport message to the gNB. The UE may be configured to perform this measurement reporting periodically, semi-persistently, oraperiodically. Typically, periodic measurement reports for LTM are carried via physical uplink control channel (PUCCH), with the PUCCH resource configuration for report transmission, reporting periodicity, and offset being configured by the serving RAN node via RRC signaling.

[0072] In contrast, semi-persistent measurement reports for LTM may be carried via PUCCH or physical uplink shared channel (PUSCH), with transmission triggered by a MAC CE from the serving RAN node. Aperiodic measurement reports for LTM may only be carried via PUSCH, with transmission being polled or triggered by downlink control information (DCI) from the serving RAN node.

[0073] Based on one or more measurement reports from the UE, the gNB decides to configure LTM for the UE and initiates preparation of one or more LTM candidate cells. In operation 2, the gNB sends an RRCReconfiguration message to the UE including LTM candidate cell configurations of one or more candidate cells. In operation 3, the UE stores the received LTM candidate cell configurations and transmits an RRCReconfigurationComplete message to the gNB.

[0074] Since a goal of LTM is to reduce interruption time for UE data transmissions, the UE needs to be ready to communicate with an LTM candidate cell upon (or shortly after) receiving the L1 / L2 signaling for mobility execution from the source cell. For example, the UE must be able to transmit UL data or a scheduling request (SR) to the LTM candidate cell and / or monitor a DL control channel (e.g., PDCCH) from the LTM candidate cell. In other words, UE needs to know the cell that it is moving to so it can apply the corresponding configuration, including the correct timing alignment and / or TCI state for the cell. Likewise, in the case of inter-DU LTM, when the source DU transmits the L1 / L2 signaling for mobility execution, the target DU needs to be prepared for scheduling UL and DL transmissions for the UE in the target cell, and for receiving SR from the UE.

[0075] The UE performs operations 4a-b before receiving any LTM cell switch command. In operation 4a, the UE performs early DL synchronization with the configured LTM candidate cells. Each LTM candidate cell configuration may include a configuration for early DL synchronization, which may also be referred to as an “LTM candidate TCI state configuration” or more simply as a “TCI state configuration.” For example, the TCI state configuration may include an RRC CandidateTCI-State IE and / or an RRC CandidateTCI-UL-State IE.

[0076] Each TCI state for an LTM candidate may be a DL TCI state, an UL TCI state, or a joint DL / UL TCI state. Each DL or joint TCI state may have one or two QCL types, each of which is associated with a DL RS. Each UL TCI state is associated with one or more DL RS.

[0077] The RRC LTM-Candidate IE may be used to provide an LTM candidate cell configuration to a UE. The LTM-Candidate IE includes an ltm-DL-OrJointTCI-StateToAddModList Q\ , which is a sequence of CandidateTCI-State IES - one for each DL or joint UL / DL TCI state to beconfigured for the LTM candidate cell. The LTM-Candidate IE also includes an Itm-UL-TCI-StateToAddModList field, which is a sequence of CandidateTCI-UL-State IES - one for each UL TCI state to be configured for the LTM candidate cell. The LTM-Candidateld field identifies the particular LTM candidate cell. Once configured in this manner, early TCI state activation in an LTM candidate cell may be triggered by an LTM candidate cell TCI state activation / deactivation MAC CE from the serving RAN node.

[0078] Returning to Figure 6 operation 4b, when UE-based TA measurement is configured, UE acquires the TA value(s) of the candidate cell(s) by measurement. Otherwise, in operation 4b, the UE performs early TA acquisition with the candidate cell(s) as requested by the network. This is done via contention-free random access (CFRA) triggered by a physical DL control channel (PDCCH) order from the source cell, following which the UE sends a RA preamble towards the indicated LTM candidate cell. In order to minimize the data interruption of the source cell due to CFRA towards the LTM candidate cell(s), the UE doesn’t receive a RA response (with TA) from the LTM candidate cell; instead, TA for the LTM candidate cell is indicated in a subsequent LTM cell switch command. Similarly, the UE doesn’t maintain a TA timer for the LTM candidate cell but relies on the RAN to guarantee the TA validity.

[0079] In operation 5, the UE performs LI measurements on the configured LTM candidate cells and transmits LI measurement reports to the gNB. The UE performs such LI measurement as long as the LTM candidate cell configurations received in operation 2 remain applicable.

[0080] In operation 6, the gNB decides to trigger an LTM cell switch for the UE to one of the configured LTM candidate cells ( “target cell”) and transmits an LTM cell switch command, which is a MAC CE that includes an identifier (e.g., index) of the corresponding LTM candidate cell configurations provided to the UE in operation 2. The MAC CE may also include an identifier of a beam (e.g., a TCI State ID) by which the UE should access the target cell.

[0081] The gNB selects the identified beam based on the LI measurements reported by the UE. These are typically per-beam measurements, such as LI reference signal received power (RSRP) for synchronization signal / PBCH blocks (SSBs). These measurements may not be layer 3 (L3) filtered, so they may change relatively frequently as UE radio conditions change. As such, it may be challenging for the gNB to determine the optimal beam to indicate to the UE in the LTM cell switch command.

[0082] Upon receiving the LTM cell switch command, the UE monitors PDCCH on the indicated beam of the target cell. In other words, the UE considers the TCI state for the indicated beam / TCI state ID to be “activated” when performing the LTM cell switch. The UE also applies the configuration identified in the MAC CE.In operation 7, if UE does not have valid TA of the target cell, the UE performs a RA procedure towards the target cell. This may also be referred to as “RACH-based LTM.” The UE performs CFRA if the LTM cell switch command contains the necessary information, as specified in clause 6.1.3.xy of 3GPP TS 38.321 (vl7.7.0). In operation 8, the UE completes the LTM cell switch procedure by sending RRCReconfigurationComplete message to the gNB via the target cell. If the LTM candidate cell configuration for the target cell included a configured UL grant of resources, the UE uses these resources for transmitting the RRCReconfigurationComplete message. Alternately, if the LTM candidate cell configuration for the target cell included SR resources instead of a configured UL grant of resources, the UE transmits a SR using these resources to obtain a grant of UL resources, which it then uses to transmit the RRCReconfigurationComplete message.

[0083] If the UE performs a RA procedure in operation 7, the UE considers that LTM cell switch execution is successfully completed when the RA procedure is successfully completed. For RACH-less LTM (e.g., when the UE performed early TA acquisition in operation 4b), the UE considers that LTM cell switch execution is successfully completed when it determines that the gNB has successfully received its initial UL data transmission (e.g., RRCReconfigurationComplete) in the target cell. The UE determines successful reception of the initial UL data by receiving a PDCCH addressing the UE’s C-RNTI in the target cell, which schedules a new transmission following the first UL data. The PDCCH carries either a DL assignment or an UL grant addressing the same HARQ process as the first UL data.

[0084] The split CU / DU architecture shown in Figure 1 also supports LTM, including for intra-DU and inter-DU / intra-CU cell changes. In the inter-DU / intra-CU scenario, the candidate cell for LTM is a cell served by a neighbor DU to the source DU that currently provides the UE’s PCell (or PSCell, for SCG change in DC). In the intra-DU scenario, the candidate cell for LTM is a cell served by the same DU that currently provides the UE’s PCell (or PSCell, for SCG change in DC). Since the procedure shown in Figure 5 involves a single gNB, it can also be considered an intra-CU LTM cell switch.

[0085] In contrast, an inter-CU (or inter-gNB) LTM procedure involves a cell switch from a source cell served by a first CU / gNB to a candidate (target) cell served by a second CU / gNB. In addition to the operations described above in relation to Figure 5, UE actions performed during an inter-CU LTM cell switch procedure may include other actions such as refresh of security keys. As such, an inter-CU LTM configuration may include the same information as an intra-CU LTM configuration as well as one or more of the following:

[0086] • Information needed to perform security key refresh, e.g., MasterKeyUpdate IE or a RadioBearerConfig IE that includes SecurityConfig with SecurityAlgorithmConfig• Indication to perform L2 / PDCP re-establishment; and

[0087] • Indication to perform a full configuration, e.g., RRC field fullConfig.

[0088] As mentioned above, there are some notable differences between Rel-18 LTM and conditional L3 mobility. For example, unlike conditional L3 mobility in which the UE initiates execution, LTM is initiated by a UE’s serving RAN node based on measurements reported by the UE. This introduces some amount of delay in an LTM cell switch. To capture advantages of both LTM and conditional L3 mobility, 3GPP Rel-19 will introduce conditional LTM (CLTM). Much like conditional L3 mobility, a UE is configured with CLTM execution conditions along with the LTM candidate cell configurations. When a UE detects CLTM execution condition(s) associated with an earlier-received LTM candidate cell configuration, the UE executes an LTM cell switch to the candidate cell.

[0089] The UE’s evaluation of a CLTM execution condition associated with an LTM candidate cell is based on lower layer measurements, such as LI reference signal received power (Ll-RSRP) and / or SS-RSRP, derived from SSBs and / or CSLRSs of the UE’s source cell and / or the LTM candidate cell. Lower layer measurements include measurements reported to support lower layer procedures like beam management, candidate cell TCI state activation / deactivation, early TA acquisition, link adaptation, etc. Unlike L3 measurements, lower layer measurements are not filtered based on L3 parameters, although some filtering may be performed based on the other lower layer parameters.

[0090] A CLTM execution condition may include an indication of the condition and / or a configuration such as event identifier(s), offset(s), threshold(s), RS type, trigger quantity (e.g., RSRP, RSRQ, SINR, etc.), time-to-trigger (TTT), etc. A CLTM execution condition may also be referred to as LTM execution condition, triggering condition, or a similar term.

[0091] For CLTM, typically a UE evaluates one or two CLTM execution conditions and performs a LTM cell switch when the CLTM execution condition(s) is / are fulfilled, without reception of an explicit LTM cell switch command from the RAN. In other words, upon satisfaction of the CLTM execution condition(s) for an LTM candidate cell, the UE initiates an LTM cell switch.

[0092] 3GPP Rel-19 will also include measurement-related enhancements for LTM. One of these enhancements is called “event-triggered LI reporting.” This enhancement is intended to address various Rel-18 LTM issues such as the following:

[0093] • Excessive UE energy consumption caused by high reporting overhead in periodic and semi -persistent LI -report types.

[0094] • Inefficient use of UL resources in periodic and semi-persistent Ll-report types in LTM.• If periodic and semi-persistent reporting intervals are increased to reduce UE energy consumption and / or improve UL resource efficiency, handover failures and / or radio link failures (RLF) may occur due to delayed updates in the channel quality at the network.

[0095] • Aperiodic LI -report in LTM may result in RLF if the report is not requested by the network in a timely manner.

[0096] The following 3 GPP agreements have been made for the proposed event-triggered LI measurement report for Rel-19:

[0097] • For event-triggered LI LTM measurement reporting, measurements for a maximum of N beams may be included into a measurement report (MR) MAC CE; and

[0098] • For event-triggered LI LTM measurement reporting, the network controls whether any beams whose measurements do not satisfy a reporting event may be reported among the maximum N beams in the MR MAC CE

[0099] In other words, when an LI event (e.g., involving a beam) that triggers a UE LI measurement report is fulfilled, the serving RAN node can control whether measurements for other beams that have not fulfilled any LI events should be included in the LI measurement report. However, the details for this have not been specified or discussed. Furthermore, it is unclear how the UE chooses (e.g., which criteria to use) the beams for which LI measurements are included in the event-triggered LI measurement report.

[0100] For example, if the UE includes beams with a very low (or poor) measurement quantity (e.g., RSRP), these beam measurements will not be relevant for any LTM decisions by the serving RAN node. Furthermore, if the UE includes many beams with a very low (or poor) measurement quantity, this unnecessarily increases signaling overhead and UL resource consumption unnecessarily. On the other hand, the UE is not required to include beams with the highest (or best) measurement quantity, so the serving RAN node is not assured of getting the measurements it needs for LTM decisions. But if the UE does not include all beam measurements that are relevant for the serving RAN node’s LTM decisions, the UE may experience delays and / or failures in LTM cell switching.

[0101] Accordingly, embodiments of the present disclosure address these and related problems and / or issues by various techniques whereby a UE may determine a sub-set of beams that did not fulfill one or more LI events to include within an event-triggered LI measurement report, along with measurement s) for beams that did fulfill the one or more LI events.

[0102] As an illustrative example, a UE may be configured with one or more LTM candidate cells, where each LTM candidate cell is associated with one or more beams, which may be further associated with RS such as SSBs. The UE is also configured with a LTM channel state information (CSI) report configuration that includes one or more LI events to be evaluated by the UE againstmeasurements of the RS (or beams) of the configured LTM candidate cells. When measurements of a first beam fulfills a first one of the configured LI events, the UE determines a sub-set of beams that did not fulfill the first LI event (and possible no other configured LI events) to include in an event-triggered LI measurement report, along with measurement(s) for the first beam that fulfilled the first LI event.

[0103] For example, the UE may determine to include beams whose measurements did not fulfill the first LI event (i.e., that the first beam fulfilled), based on one or more of the following rules:

[0104] • when all beams whose measurements have fulfilled the first LI event have been included in the event-triggered LI measurement report, and the resource capacity allocated for the report is sufficient to report additional beams whose measurements do not fulfill the first LI event (and possibly no other configured LI events);

[0105] • when measurements of a beam did not fulfill the first LI event but is / are above another threshold (i.e., different than the first LI event).

[0106] • when measurements of a beam did not fulfill the first LI event but the beam was indicated in an early synchronization procedure.

[0107] • when measurements of a beam did not fulfill the first LI event but the beam is part of an LTM candidate cell associated with measurements (e.g., of the first beam) that fulfilled the first LI event that triggered the LI measurement report.

[0108] • when measurements of a beam did not fulfill the first LI event but L3 measurements of this beam fulfill an L3 event.

[0109] Embodiments of the present disclosure may provide various advantages and / or benefits. For example, embodiments may enable a UE to include in an event-triggered LI measurement report beams whose measurements are relevant and / or usable by the serving RAN node to make informed and / or optimal LTM decisions for the UE. Furthermore, embodiments enable the UE to avoid including beams that are not relevant and / or usable by the serving RAN node for LTM decisions, thereby reducing signaling overhead and UE energy consumption. By avoiding over-or under-inclusiveness of beams in event-triggered LI measurement reports, embodiments facilitate timely LTM decisions by the serving RAN node, thereby reducing HO failures, RLFs, LTM cell switch latency, and connection interruptions.

[0110] The term “LTM candidate cell” refers to a cell for which the UE is configured for LTM, specifically a cell the UE can move to in a LTM cell switch procedure in response to receiving an LTM cell switch command. An LTM candidate cell is one example of the more generic term “mobility candidate cell.” A UE may perform and report measurements (e.g., CSI measurements) on an LTM candidate cell, based on which the UE’s serving RAN node may make an informed decision about which beam (or TCI state) and / or cell to switch the UE. An LTM candidate cellmay be a candidate to be a target PCell or PSCell, or an SCell of a cell group (e.g., MCG SCell). In the case of LTM fast recovery, when a failure is detected and the UE selects an LTM candidate cell, the UE performs an LTM cell switch towards the selected LTM candidate cell (e.g., by applying the associated LTM candidate cell configuration) rather than performing RRC reestablishment.

[0111] The change of serving cell (e.g., PCell) may also lead to a change in SCell(s) of the same cell group, e.g., in case an LTM cell switch command triggers the UE to change to another cell group configuration of the same type (e.g., another MCG configuration). For example, an LTM cell switch may include a change in SpCell (e.g., PCell for MCG, PSCell for SCG) and a change (e.g., addition, modification and / or release) in SCells of the same cell group. This may happen when the command triggers the UE to change to another cell group configuration of the same type (e.g., another SCG configuration).

[0112] Before the UE receives the LTM cell switch command, the UE is configured by the network with one or more “LTM candidate cell configurations” via an RRCReconfiguration message. The terms “(LTM) candidate configuration”, “(LTM) candidate target cell configuration”, and “(LTM) target candidate (cell) configuration” may be used interchangeably with LTM candidate cell configuration.

[0113] An LTM candidate cell configuration may be included in an RRC IE such as CellGroupConfig, SpCellConfig, or SCellConfig and / or an embedded RRCReconfiguration message for an LTM candidate cell. An LTM candidate cell configuration includes configuration parameters the UE needs to operate in that LTM candidate cell when it performs an LTM cell switch procedure, e.g., upon reception of the LTM cell switch command. As some more specific examples, an LTM candidate cell configuration can include a PCell configuration and one or more SCell configurations of an MCG, or a PSCell configuration and one or more SCell configurations of an SCG. The exact content and / or structure of the IE and / or embedded message for an LTM candidate cell configuration may be called “RRC model for the candidate configuration” or more simply “RRC model”.

[0114] A UE may receive an LTM candidate cell configuration in complete form or as a delta (or difference) relative to a reference configuration (which may be signaled separately). In the latter case, the actual LTM candidate configuration is a combination of the delta configuration and the reference configuration. For non-conditional LTM, an identifier (or index) associated with an LTM candidate cell configuration may be sent together with an LTM cell switch command, indicating for the UE to perform an LTM cell switch to the associated LTM candidate cell.

[0115] The term “LTM configuration” refers to a data structure that is used for or related to UE LTM operations, and may include one or more of the following elements (non-exclusive):an LTM candidate cell configuration, such as one or more of the following for an LTM candidate cell:

[0116] o lower layer information, such as Ll / PHY configuration, L2 / MAC / RLC configuration, cell group configuration, serving cell configuration, etc.; and

[0117] o higher layer information, such as L3 / RRC parameter and / or timer values, PDCP configuration, radio bearer configuration, L3 / RRC measurement configuration, etc.;

[0118] • a measurement configuration, e.g., measurements for LTM, measurement reports for LTM, CSI resource configuration for LTM, CSI report configuration for LTM, etc.; • a configuration for early DL synchronization, e.g., for early TCI state activation;

[0119] • a configuration for early UL synchronization, e.g., for transmission of PDCCH ordered preamble transmission and reception of timing advance (TA);

[0120] • a configuration for execution of an LTM cell switch procedure according to a given LTM candidate cell configuration (e.g., whether to perform RA, RLC reestablishment, MAC reset, PDCP recovery, etc.).;

[0121] • additional information needed for an intra-CU / gNB LTM cell switch procedure.

[0122] The term “part of an LTM configuration” may refer to a subset of the elements in the above list, and / or a subset of items comprising any of the elements present (e.g., subset of configurations for DL pre-sync).

[0123] As part of the measurement configuration, a UE may be configured to perform “lower layer measurements,” such as LI reference signal received power (RSRP), on synchronization signal block (SSB) and / or channel state information reference signal (CSLRS). These may be referred to more generally as “LTM CSI measurements.” The UE may also be configured to report these lower layer measurements to support procedures like LTM, beam management, TCI state activations / deactivations, early TA acquisition, link adaptation, etc. Unlike L3 measurements, the UE does not filter lower layer measurements based on L3 parameters, although ion some cases the UE may filter lower layer measurements based on LI parameters. Based on the UE’s reporting of lower layer measurements, the serving RAN node makes decision about which beam (e.g., TCI state) and / or cell the UE should be switched to.

[0124] In general, RS on which lower layer measurements should be performed are identified in an RRC LTM-CSI-SSB-ResourceSet information element (IE) that is part of an LTM CSI Resource Configuration. For example, an SSB Index may be used to uniquely identify each SSB of an LTM candidate cell, or a serving cell, that should be measured by the UE. Figure 6 shows an exemplary RRC LTM-CSI-SSB-ResourceSet IE. In this example, the ith position of the list in the Itm-CSI-SSB-ResourceList field indicates the SSB index of the RS resource to be measured, while the sameith position of the list in the Itm-CandidateldList field indicates the index of the LTM candidate configuration to which the RS resource (or SSB index) belongs.

[0125] In general, LI event types are different classes of LTM-related events, with alphanumeric labels such as LTM2, LTM3, LTM4, etc.. An LI event (or event instance) is a specific event of a particular LI event type, e.g., an LTM3 event configured with particular parameters (or conditions) such as offset, threshold, time-to-trigger (TTT), etc. An LI event may be associated with an LTM resource configuration and may be uniquely identified by an LI event identifier that is understood by both the UE and the serving RAN node. The configured parameters for LTM events may also be referred to as trigger conditions, event conditions, LTM event conditions, event trigger conditions, etc.

[0126] Lower layer measurements on RS may be of a particular quantity or parameter, which is also referred to as “measurement quantity.” Some example measurement quantities are:

[0127] • Ll-RSRP from SS-RSRP or CSLRSRP,

[0128] • Ll-signal-to-interference and noise ratio (SINR) from SS-SINR or CSLSINR, and

[0129] • Ll-reference signal received quality (RSRQ) from SS-RSRQ or CSLRSRQ,

[0130] In Rel-18 LTM Ll-reporting, the reported measurement quantity is SS-RSRP for the LTM measurement resource having the highest SS-RSRP measurement, along with differential SS-RSRPs (with respect to the highest SS-RSRP measurement) for one or more other LTM measurement resources. The value of a measurement quantity that a UE reports may be referred to as a “measurement quantity value”, “measurement value”, or more simply as a “measurement” or “reported measurement” when it is clear what is being reported in the particular context. Likewise, a value of a measurement quantity that meets a condition associated with an LI event (and triggers an LI measurement report) may be referred to as a “triggering measurement quantity value” or more simply a “triggering measurement” when it is otherwise clear from the context.

[0131] The phrase “LTM cell switch procedure” refers to the process of a UE switching (or changing) from a source cell to a target cell (i.e., an LTM candidate cell) using LTM. An LTM cell switch procedure may also be referred to as “L1 / L2 based inter-cell mobility execution”, “LTM execution”, “dynamic switch”, “LTM switch”, “(LTM) cell switch”, “(LTM) serving cell change”, or “(LTM) cell change”. Similarly, the phrase “switching to an LTM candidate cell configuration” means that the UE applies an LTM candidate cell configuration such that the associated LTM candidate cell becomes its new special cell (SpCell, e.g., PCell for LTM in MCG or PSCell for LTM in SCG) or its new SCell. In other words, an LTM candidate cell can be a candidate for the UE’s PCell, PSCell, or SCell.

[0132] Furthermore, an LTM cell switch may involve a UE switching (or changing) from a source cell group to a target cell group using LTM. For example, this may involve a change in the SpCellfor a cell group (e.g., PCell for MCG, PSCell for SCG), a change in SCells of the cell group (e.g., addition, modification, and / or release of one or more SCells), and / or a swap between SpCell and SCell roles for two cells in the same cell group. More generally, embodiments are not limited to cells but are applicable to any UE switch from a first (or source) set of radio resources to a second (or target) set of radio resources.

[0133] Although embodiments are primarily described in the context of LTM, principles of disclosed embodiments are also applicable to conditional LTM or, more generally, conditional mobility. In the present disclosure, the terms “conditional configuration” and “conditional reconfiguration” may be used to refer to a configuration for UE execution of a mobility procedure (which may be referred to as a “conditional mobility procedure”), which includes one or more execution conditions that trigger UE execution of the mobility procedure. A conditional configuration may include a message (e.g., RRCReconfiguration or a portion thereof such as an IE, that the UE applies when executing the mobility procedure upon fulfillment of the execution condition(s).

[0134] The mobility procedure may be CLTM, CHO, CPC, CPA, conditional PSCell release or suspend, etc. In one example, a conditional configuration may be a conditional LTM (CLTM) configuration and upon fulfillment of the execution condition(s), the UE performs an LTM cell switch to an LTM candidate cell. The execution conditions may relate to lower-layer (e.g., LI) measurements such as Ll-RSRP, SS-RSRP, etc. of a UE’s serving cell and / or a mobility candidate cell. Such lower-layer measurements may also be used for other lower layer procedures such as beam management, TCI state activation / deactivations, link adaptation, etc. In some procedures, the execution conditions may relate to layer-3 (L3) measurements of RSRP, RSRQ, SINR, etc. which are often filtered versions of lower-layer measurements.

[0135] In some cases, CLTM may be part of a unified mobility procedure in which the UE may expect a command (e.g., MAC CE) from the network to trigger a non-conditional LTM cell switch to an LTM candidate for which the UE is also monitoring CLTM execution conditions.

[0136] Embodiments will now be described in more detail. In some embodiments, a UE is configured with one or more LTM candidate cells, where each LTM candidate cell is associated with one or more beams, which may be further associated with RS such as SSBs. The UE is also configured with a LTM CSI report configuration that includes or identifies one or more LI events to be evaluated by the UE against measurements of the RS (or beams) of the configured LTM candidate cells. When measurements of a first beam fulfills a first one of the configured LI events, the UE determines a sub-set of beams that did not fulfill the first LI event (and possibly no other configured LI events) to include in an event-triggered LI measurement report, along with measurement(s) for the first beam that fulfilled the first LI event.In some embodiments, a UE is configured with one or more LTM candidate cells, where each LTM candidate cell is associated with one or more beams, which may be further associated with RS such as SSBs. The UE is also configured with a LTM CSI reporting configuration that includes or identifies one or more LTM CSI resources (e.g., beams or RS in LTM candidate cells) to be measured by the UE, and one or more LI events to be evaluated by the UE against measurements of the configured LTM CSI resources. For example, each LTM CSI resource may include or indicate a beam or RS (e.g., SSB index) and a configured LTM candidate cell associated with the RS. The LI event configuration identifies a condition to be fulfilled and which of the LTM CSI resources should fulfil the condition.

[0137] The UE performs measurements of the configured LTM CSI resources and evaluates the measurements against the corresponding configured LI events. When measurements of one of the configured LTM CSI resources (e.g., a first beam in a first LTM candidate cell) fulfills a first LI event, the UE determines that an event-triggered LI measurement report needs to be transmitted. The UE will include in the LI measurement report the measurement results of the LTM CSI resource (i.e., the first beam) that fulfilled the first LI event.

[0138] Furthermore, the UE determines a sub-set of beams (or LTM CSI resources) that did not fulfill the first LI event (and possibly no other configured LI events) to include in the event-triggered LI measurement report, along with measurement(s) for the first beam that fulfilled the first LI event. Some exemplary rules or criteria for determining the subset are discussed below. For each beam in this subset, the UE includes in the report an explicit indication that this beam did not fulfilled any LI event condition.

[0139] In some embodiments, the UE may determine to include beams whose measurements did not fulfill the first LI event (and possibly no other configured LI events), when all beams whose measurements fulfilled the first LI event have been included in the event-triggered LI measurement report, and the resource capacity allocated for the report is sufficient to report additional beams whose measurements did not fulfill the first LI event.

[0140] In these embodiments, beams whose measurements fulfilled a LI event have priority to be included in the event-triggered LI measurement report. This means that the UE will include a beam whose measurements did not fulfill the first LI event (and possibly no other configured LI events) only after all beams that fulfilled the first LI event have been included within the report. When beams whose measurements fulfilled the first LI event occupy the entire allocated resources for the LI measurement report, the UE does not include any beams whose measurements did not fulfill the first LI event (and possibly no other configured LI events).

[0141] These operations may be verified in test lab environment or by simulation, whereby a UE is configured with a candidate configuration that identifies multiple RS to be measured and an LIevent, such that always the same sub-set of beams would fulfill the LI event. It could then be observed whether the UE reports beams that are known not to fulfill the LI event, in addition to the fulfilling beams.

[0142] In some embodiments, the UE may determine to include beams whose measurements do not fulfill the first LI event (and possibly no other configured LI events) but is / are above another threshold (i.e., different than the configured LI events).

[0143] In these embodiments, the UE may determine the threshold and all the beams whose LI measurement quantity (e.g., RSRP, RSRQ, SINR, RSSI) is above such threshold are candidates to be included in the event-triggered LI measurement report. After giving priority the beam(s) fulfilling the first LI event, the UE will also include beams that did not fulfilled the first LI event but whose measurements were above the threshold. In some variants, the UE includes the beams above the threshold when the number of beans above the threshold to not exceed the maximum number of beams to be reported. In other variants, the UE may include the beams whose measurements were above the threshold regardless of whether they also fulfilled an LI event.

[0144] These operations may be verified in test lab environment or by simulation, whereby a UE is configured with a candidate configuration that identifies multiple RS to be measured and an LI event. It could then be observed whether the measurement quantity of the beams reported by the UE is always above a certain number, representing the threshold chosen by the UE. The same behavior should be observed even if the UE is configured with a different candidate cell and / or with different RS to measure.

[0145] In some embodiments, the number (N) of reported beams whose measurements do not fulfill the first LI event (and possibly no other configured LI event) may be constant or fixed, regardless of the number of candidate configurations or RS to be measured. In other variants, N may depend (or be based) on the number of RS to be measured and / or on the LTM candidate cell associated with the beams whose measurements triggered the event-triggered LI measurement report.

[0146] These operations may be verified in test lab environment or by simulation, whereby a UE is configured with a candidate configuration that identifies multiple RS to be measured and an LI event. In this case, from the measurement report received by the UE, it may be observed that the number of reported beams that do not fulfill an LI event condition is always the same. The same behavior would be observed even if the UE is configured with a different candidate cell of with different reference signal to measure.

[0147] In some embodiments, the UE may determine to include a beam whose measurements do not fulfill the first LI event (and possibly no other configured LI event) when the beam wasindicated (or used) in an early synchronization procedure. For example, such a beam could have been indicated in a PDCCH order for early TA acquisition (i.e., early UL synchronization), or that the TCI state linked to such beam has been activated for early DL synchronization.

[0148] In some variants, the UE may also condition inclusion of a non-fulfilling beam on whether this beam is associated with the same candidate configuration as the beam whose measurements fulfilled the first LI event and triggered the LI measurement report. In other variants, the UE may also condition inclusion of a non-fulfilling beam on whether this beam is associated with an LTM candidate cell for which early UL synchronization was previously performed / triggered. In other variants, the UE may also condition inclusion of a non-fulfilling beam on whether this beam is associated with an LTM candidate cell for which early DL synchronization was previously performed / triggered.

[0149] These operations may be verified in test lab environment or by simulation, whereby a UE is configured with a candidate configuration that identifies multiple RS to be measured and an LI event. In this case, an early synchronization procedure may be triggered for the candidate cell and from the measurement report received by the UE, it may be observed whether the UE has included beams that do not fulfill an LI event condition. The same behavior would be observed even if the UE is configured with a different candidate cell of with different reference signal to measure.

[0150] In some embodiments, the UE may determine to include a beam whose measurements do not fulfill the first LI event (and possibly no other configured LI event) when the beam is part of an LTM candidate cell associated with measurements (e.g., of the first beam) that fulfilled the LI event that triggered the LI measurement report. These operations may be verified in test lab environment or by simulation, whereby a UE is configured with at least two candidate configurations that identify multiple RS to be measured but only one of these candidate configuration triggers an event-triggered LI measurement report. It could be observed that the reported beams whose measurements do not fulfill an LI event are all from the candidate cell whose beam measurements fulfilled the LI event and triggered the LI measurement report. The same behavior would be observed even if beam measurements that fulfilled the LI event and triggered the LI measurement report were associated with a different candidate cell.

[0151] In some embodiments, the UE may determine to include a beam whose measurements do not fulfill the first LI event (and possibly no other configured LI event) when L3 measurements of this beam fulfill a configured L3 event. For example, the UE may determine that that beam is relatively good over time since L3 measurements are time-filtered. This rule or criterion may be combined with other rules or criteria disclosed herein, e.g., the beam is included only if its L3 measurement is above a threshold and / or the L3 measurement fulfilled some configured L3 event previously.In some embodiments, the UE may determine to include a beam whose measurements do not fulfill the first LI event (and possibly no other configured LI event) when an early UL synchronization procedure was triggered previously on this beam. In other words, the UE may include a beam associated with an LTM candidate cell for which the UE has a valid TA (e.g., indicated by a running Time Alignment timer). In another option, the UE may include a beam for which a previously received PDCCH order instructed the UE to send a preamble to the LTM candidate cell via this beam.

[0152] These operations may be verified in test lab environment or by simulation, whereby a UE is configured with a candidate configuration that identifies multiple RS to be measured. In this case, an early UL synchronization procedure with the LTM candidate cell (associated with the candidate configuration) may be triggered for the UE, and the UE’s LI measurement report indicates whether the UE has included beams that do fulfill an LI event.

[0153] In some embodiments, the UE may determine to include a beam whose measurements do not fulfill the first LI event (and possibly no other configured LI event) when an early DL synchronization procedure was triggered previously on this beam. In other words, the UE previously received a TCI state activation MAC CE for this beam, causing this beam (corresponding to the TCI state) to be activated.

[0154] These operations may be verified in test lab environment or by simulation, whereby a UE is configured with a candidate configuration that identifies multiple RS to be measured. In this case, an early DL synchronization procedure (i.e., activating a TCI state which is related to a beam) for the candidate cell may be triggered for the UE, and the measurement report received from the UE indicates whether the UE has included beams whose measurements do not fulfill a configured LI event.

[0155] In some embodiments, the UE may determine to include a beam whose measurements do not fulfill the first LI event (and possibly no other configured LI event) based on the number of beams associated with the same LTM candidate cell (i.e., as the non-fulfilling beam) that have fulfilled a configured LI event. In other words, the UE may include in the event-triggered LI measurement report a non-fulfilling beam when a certain number (X) of beams from the same LTM candidate cell have fulfilled configured LI events.

[0156] In some variants, X may be a minimum, such that the UE includes a non-fulfilling beam when at least X fulfilling beams associated with the same LTM candidate cell are included. In other variants, X may be a maximum, such that the UE includes a non-fulfilling beam when at most X fulfilling beams associated with the same LTM candidate cell are included. In this manner, the combination of fulfilling and non-fulfilling beams provides a better overview for network LTM decisions. In some variants, X may be common to all configured LTM candidatecells. In other variants, X may be specific to each LTM candidate cell. In other variants, X may be LI event-specific.

[0157] These operations may be verified in test lab environment or by simulation, whereby a UE is configured with a candidate configuration that identifies multiple RS to be measured. In this case, it may be observed in UE measurement reports that non-fulfilling beam(s) is / are always included when the number of fulfilling beams (associated with the same candidate cell) is above (or below) X. The same behavior should be observed even if the UE is configured with a different LTM candidate cell or with different RS to measure.

[0158] In some embodiments, the UE may determine to include a beam whose measurements do not fulfill the first LI event (and possibly no other configured LI event) based on the same number (M) of beams associated with each LTM candidate cell being included in the LI measurement report. In other words, if two fulfilling beams for an LTM candidate cell are included, then the UE determines to include M-2 non-fulfilling beams associated with the same LTM candidate cell in the LI measurement report. Put differently, the UE first includes the fulfilling beams for the LTM candidate cell and, if less than M fulfilling beams are included, the UE then includes non-fulfilling beams such that M total beams for the LTM candidate cell are included.

[0159] These operations may be verified in test lab environment or by simulation, whereby a UE is configured with a candidate configuration that identifies multiple RS to be measured. In this case, it may be observed that the same number of beams for an LTM candidate cell are always included in UE measurement reports, with different mixtures of fulfilling and non-fulfilling beams according to the test conditions applied. The same behavior should be observed even if the UE is configured with a different LTM candidate cell or with different RS to measure.

[0160] In some embodiments, the UE may determine to include a beam whose measurements do not fulfill the first LI event (and possibly no other configured LI event) based on one or more of the following criteria pertaining to the LTM candidate cell associated with the beam:

[0161] • whether L2 reset is needed for the LTM candidate cell associated with the beam;

[0162] • whether a change of security is needed for the LTM candidate cell associated with the beam;

[0163] • whether the LTM candidate cell associated with the beam is both an LTM candidate cell and a CLTM candidate cell;

[0164] • whether the LTM candidate cell associated with the beam is both an LTM candidate cell and a CHO candidate cell; and

[0165] • frequency and / or subcarrier spacing of the LTM candidate cell associated with the beam.

[0166] In some embodiments, the UE may determine to include a beam whose measurements do not fulfill the first LI event (and possibly no other configured LI event) based on whether theLTM candidate cell associated with the beam contains contention free random access (CRFA) resources to be used for the first transmission (i.e., of a RA preamble) when an LTM cell switch is triggered. The CFRA resources are a pre-allocated set of resources that the UE can use when executing an LTM cell switch.

[0167] These operations may be verified in test lab environment or by simulation, whereby a UE is configured with at least two candidate configurations that identify multiple RS to be measured. In this case, only one of the two candidate configurations includes CFRA resources for the LTM candidate cell. When an event-triggered LI measurement report is received, it may be observed whether the included non-fulfilling beams are all from the LTM candidate cell for which CFRA resources are configured.

[0168] In some embodiments, the UE may determine to include a beam whose measurements do not fulfill the first LI event (and possibly no other configured LI event) based on whether the configuration of the LTM candidate cell associated with the beam includes a configured grant to be used for the UE’s initial transmission (e.g., of UL data or signaling) in the cell after an LTM cell switch. The configured grant is a pre-allocated set of UL resources that the UE can use when executing an LTM cell switch.

[0169] These operations may be verified in test lab environment or by simulation, whereby a UE is configured with at least two candidate configurations that identify multiple RS to be measured. In this case, only one of the two candidate configurations includes a configured grant for the LTM candidate cell. When an event-triggered LI measurement report is received, it may be observed whether the included non-fulfilling beams are all from the LTM candidate cell whose configuration includes the configured grant of UL resources.

[0170] In some embodiments, the UE may determine to include a beam whose measurements do not fulfill the first LI event (and possibly no other configured LI event) based on one or more of the following numerical criteria:

[0171] • a maximum ratio or percentage of such beams among the (maximum) total number of beams that may be included in an event-triggered LI measurement report (e.g., 50% of total beams, which would be four if maximum total number of beams is eight); and • random selection.

[0172] Various features of the embodiments described above correspond to various operations illustrated in Figure 7, which shows an exemplary method (e.g., procedures) for a UE. In other words, various features of the operations described below correspond to various embodiments described above. Although Figure 7 show specific blocks in particular orders, the operations of the exemplary method may be performed in different orders than shown and can be combined and / or divided into blocks having different functionality than shown. Optional blocks oroperations are indicated by dashed lines. The exemplary method may be performed by any appropriate UE (e.g., wireless device) such as described elsewhere herein.

[0173] The exemplary method includes the operations of block 720, where the UE performs lower layer measurements on a plurality of beams associated with one or more mobility candidate cells. The exemplary method also includes the operations of block 730, where the UE determines that the lower layer measurements of a first subset of the plurality of beams fulfill one or more conditions that trigger measurement reporting. The exemplary method also includes the operations of block 750, where the UE selects a second subset of the plurality of beams whose lower layer measurements do not fulfill the one or more conditions that trigger measurement reporting. Each beam of the second subset is selected based on one or more of the following:

[0174] • a measurement value being at least a threshold value,

[0175] • being involved in an early synchronization of the UE with the mobility candidate cell associated with the beam, and

[0176] • being associated with a same mobility candidate cell as one or more beams of the first subset.

[0177] The exemplary method also includes the operations of block 760, where the UE sends, to a RAN node that provides a serving cell for the UE, a measurement report comprising measurement values for the first subset of beams and measurement values for the second subset of beams.

[0178] In some embodiments, the measurement report further comprises, for each beam in the second subset, an explicit indication that the lower layer measurements for the beam did not fulfill any condition for measurement reporting.

[0179] In some embodiments, the one or more mobility candidate cells are layer-l / layer-2 triggered mobility (LTM) candidate cells, the lower layer measurements are layer-1 (LI) measurements, and the conditions for measurement reporting are associated with LI events. In some of these embodiments, the exemplary method also includes the operations of block 710, where the UE receives the following from the RAN node:

[0180] • LTM candidate configurations for the respective one or more LTM candidate cells, and • an LTM reporting configuration that identifies the following: the plurality of beams to be measured by the UE, and at least one of the conditions for LI measurement reporting. In some variants of these embodiments, the LTM reporting configuration identifies a plurality of LTM channel state information (CSI) resources corresponding respectively to the plurality of beams to be measured. Also, each of the plurality of LTM CSI resources identifies a reference signal (RS) associated with the corresponding beam and an LTM candidate cell associated with the RS. In some further variants, the LTM reporting configuration further identifies which of the plurality of LTM CSI resources should fulfill each of the at least onecondition for LI measurement reporting.

[0181] In some embodiments, the second subset of beams is selected further based on a size of the reported measurement values for the first subset being less than an allocated resource capacity for the measurement report. In some of these embodiments, a number of beams in the second subset is zero when the size of the reported measurement values for the first subset is substantially equal to the allocated resource capacity for the measurement report.

[0182] In some embodiments, a total number of beams in the first and second subsets is less than a maximum number of beams that may be reported. In some embodiments, the measurement values for one or more beams of the first subset are at least the threshold value.

[0183] In some embodiments, a total number of beams in the second subset is one of the following: constant, based on how many beams on which the lower layer measurements are performed, or based on how many mobility candidate cells on which the lower layer measurements are performed.

[0184] In some embodiments, one or more beams of the second subset are selected based on being involved in one or more of the following: early uplink synchronization, and early downlink synchronization.

[0185] In some embodiments, the threshold value is for one of the following: reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-interference-and-noise ratio (SINR), and received signal strength (RSSI).

[0186] In some embodiments, the exemplary method also includes the operations of block 740, where the UE performs upper layer measurements on the plurality of beams associated with the one or more mobility candidate cells. One or more beams of the second subset are selected further based on their upper layer measurements fulfilling one or more further conditions that trigger upper layer measurement reporting. In some of these embodiments, the lower layer measurements are LI measurements, and the upper layer measurements are layer-3 (L3) measurements that have been time-filtered.

[0187] In some embodiments, one or more beams of the second subset are selected further based on one or more of the following:

[0188] • the UE having a valid timing advance for the associated candidate cell,

[0189] • the UE having previously received a physical downlink control channel (PDCCH) order instructing the UE to transmit a random access preamble via the beam to the associated mobility candidate cell,

[0190] • the UE having previously received a transmission configuration indicator (TCI) state activation command for the beam, and

[0191] • the UE’s TCI state corresponding to the beam being activated.In some embodiments, one or more beams of the second subset are selected further based on one or more of the following:

[0192] • whether layer-2 (L2) reset is needed for the associated mobility candidate cell;

[0193] • whether a change of security is needed for the associated mobility candidate cell;

[0194] • whether the mobility candidate cell associated with the beam is both an non-conditional mobility candidate cell and a conditional mobility candidate cell;

[0195] • whether the mobility candidate cell associated with the beam is both a L1 / L2 mobility candidate cell and an L3 mobility candidate cell; and

[0196] • frequency and / or subcarrier spacing of the associated mobility candidate cell.

[0197] In some embodiments, one or more beams of the second subset are selected further based on being associated with a same mobility candidate cell as one of the following: at least a minimum number of beams of the first subset, or no more than a maximum number of beams of the first subset. In some of these embodiments, the minimum number or the maximum number is one of the following: common to all of the mobility candidate cells, specific to each of the mobility candidate cells, or specific to each of the conditions for measurement reporting.

[0198] In some embodiments, one or more beams of the second subset are selected further based on a condition that the measurement report include measurement values for a same number of beams associated with each of the mobility candidate cells. In some embodiments, one or more beams of the second subset are selected further based on one or more of the following being configured for the UE in the associated mobility candidate cells: contention-free random access (CFRA) resources, and a grant of uplink resources.

[0199] In some embodiments, one or more beams of the second subset are selected further based on one of the following:

[0200] • a maximum ratio or percentage of a total number of beams in the second subset relative to a total number of beams having measurement values included in the measurement report; and

[0201] • a random selection algorithm.

[0202] Although various embodiments are described above in terms of methods, techniques, and / or procedures, the person of ordinary skill will readily comprehend that such methods, techniques, and / or procedures can be embodied by various combinations of hardware and software in various systems, communication devices, computing devices, control devices, apparatuses, non-transitory computer-readable media, computer program products, etc.

[0203] Figure 8 shows an example of a communication system 800 in accordance with some embodiments. In this example, communication system 800 includes a telecommunication network 802 that includes an access network 804 (e.g., RAN) and a core network 806, which includes oneor more core network nodes 808. Access network 804 includes one or more access network nodes, such as network nodes 810a-b (one or more of which may be generally referred to as network nodes 810), or any other similar 3 GPP access nodes or non-3GPP access points. Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, telecommunication network 802 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in telecommunication network 802 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in telecommunication network 802, including one or more network nodes 810 and / or core network nodes 808.

[0204] Examples of an ORAN network node include an open radio unit (O-RU), an open distributed unit (O-DU), an open central unit (O-CU), including an O-CU control plane (O-CU-CP) or an O-CU user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN access node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an O-2 interface defined by the O-RAN Alliance or comparable technologies. Network nodes 810 facilitate direct or indirect connection of UEs, such as by connecting UEs 812a-d (one or more of which may be generally referred to as UEs 812) to core network 806 over one or more wireless connections.

[0205] Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, communication system 800 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / orsignals whether via wired or wireless connections. Communication system 800 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0206] UEs 812 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with network nodes 810 and other communication devices. Similarly, network nodes 810 are arranged, capable, configured, and / or operable to communicate directly or indirectly with UEs 812 and / or with other network nodes or equipment in telecommunication network 802 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in telecommunication network 802.

[0207] In the depicted example, core network 806 connects network nodes 810 to one or more hosts, such as host 816. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. Core network 806 includes one or more core network nodes (e.g., 808) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of core network node 808. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0208] Host 816 may be under the ownership or control of a service provider other than an operator or provider of access network 804 and / or telecommunication network 802, and may be operated by the service provider or on behalf of the service provider. Host 816 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0209] As a whole, communication system 800 of Figure 8 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal MobileTelecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

[0210] In some examples, telecommunication network 802 is a cellular network that implements 3GPP standardized features. Accordingly, telecommunication network 802 may support network slicing to provide different logical networks to different devices that are connected to telecommunication network 802. For example, telecommunication network 802 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC) / Massive loT services to yet further UEs.

[0211] In some examples, UEs 812 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit information to access network 804 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from access network 804. Additionally, a UE may be configured for operating in single- or multi -RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e., being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

[0212] In the example, hub 814 communicates with access network 804 to facilitate indirect communication between one or more UEs (e.g., 812c and / or 812d) and network nodes (e.g., 810b). In some examples, hub 814 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, hub 814 may be a broadband router enabling access to core network 806 for the UEs. As another example, hub 814 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 810, or by executable code, script, process, or other instructions in hub 814. As another example, hub 814 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, hub 814 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, hub 814 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which hub 814 then provides to the UE either directly, after performing localprocessing, and / or after adding additional local content. In still another example, hub 814 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[0213] Hub 814 may have a constant / persistent or intermittent connection to network node 810b. Hub 814 may also allow for a different communication scheme and / or schedule between hub 814 and UEs (e.g., 812c and / or 812d), and between hub 814 and core network 806. In other examples, hub 814 is connected to core network 806 and / or one or more UEs via a wired connection. Moreover, hub 814 may be configured to connect to an M2M service provider over access network 804 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with network nodes 810 while still connected via hub 814 via a wired or wireless connection. In some embodiments, hub 814 may be a dedicated hub - that is, a hub whose primary function is to route communications to / from the UEs from / to network node 810b. In other embodiments, hub 814 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 810b, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0214] In some embodiments, UE 812 may be configured to perform operations attributed to a UE in embodiments described above, including the exemplary method shown in Figure 7.

[0215] Figure 9 shows a UE 900 in accordance with some embodiments. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart device, wireless customer-premise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, etc. Other examples include any UE identified by 3 GPP, including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0216] A UE may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may representa device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0217] UE 900 includes processing circuitry 902 that is operatively coupled via bus 904 to input / output interface 906, power source 908, memory 910, communication interface 912, and possibly other components not explicitly shown. Certain UEs may utilize all or a subset of the components shown in Figure 9. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0218] Processing circuitry 902 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in memory 910. Processing circuitry 902 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general -purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, processing circuitry 902 may include multiple central processing units (CPUs).

[0219] In the example, input / output interface 906 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into UE 900. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0220] In some embodiments, power source 908 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. Power source 908 may further include power circuitry for delivering power from power source 908 itself, and / or an external power source, to the various parts of UE 900 via input circuitry or an interface such as an electrical power cable. Deliveringpower may be, for example, for charging of power source 908. Power circuitry may perform any formatting, converting, or other modification to the power from power source 908 to make the power suitable for the respective components of UE 900 to which power is supplied.

[0221] Memory 910 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, memory 910 includes one or more application programs 914, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 916. Memory 910 may store, for use by UE 900, any of a variety of various operating systems or combinations of operating systems.

[0222] Memory 910 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ Memory 910 may allow UE 900 to access instructions, application programs and the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in memory 910, which may be or comprise a device-readable storage medium.

[0223] Processing circuitry 902 may be configured to communicate with an access network or other network using communication interface 912. Communication interface 912 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 922. Communication interface 912 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 918 and / or a receiver 920 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, transmitter 918 and receiver 920 may be coupled to one or more antennas (e.g., antenna 922) and may share circuit components, software, or firmware, or alternatively be implemented separately.In the illustrated embodiments, communication functions of communication interface 912 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / internet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0224] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 912, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0225] As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0226] A UE, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door / window sensor, a flood / moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a head-mounted display for Augmented Reality (AR) or Virtual Reality (VR), a wearable for tactile augmentation or sensory enhancement, a water sprinkler, ananimal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and / or software in dependence of the intended application of the loT device in addition to other components as described in relation to UE 900 shown in Figure 9.

[0227] As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements, and transmits the results of such monitoring and / or measurements to another UE and / or a network node. The UE may in this case be an M2M device, which may in a 3 GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0228] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g., by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

[0229] In some embodiments, UE 900 may be configured to perform operations attributed to a UE in various embodiments described above, including the exemplary method shown in Figure 7.

[0230] The foregoing merely illustrates the principles of the disclosure. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements, and procedures that, although not explicitly shown or described herein, embody the principles of the disclosure and can be thus within the spirit and scope of the disclosure. Various embodiments can be used together with one another, as well as interchangeably therewith, as should be understood by those having ordinary skill in the art.

[0231] The term unit, as used herein, can have conventional meaning in the field of electronics, electrical devices and / or electronic devices and can include, for example, electrical and / or electronic circuitry, devices, modules, processors, memories, logic solid state and / or discrete devices, computer programs or instructions for carrying out respective tasks, procedures,computations, outputs, and / or displaying functions, and so on, as such as those that are described herein.

[0232] Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processor (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and / or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according to one or more embodiments of the present disclosure.

[0233] As described herein, device and / or apparatus can be represented by a semiconductor chip, a chipset, or a (hardware) module comprising such chip or chipset; this, however, does not exclude the possibility that a functionality of a device or apparatus, instead of being hardware implemented, be implemented as a software module such as a computer program or a computer program product comprising executable software code portions for execution or being run on a processor. Furthermore, functionality of a device or apparatus can be implemented by any combination of hardware and software. A device or apparatus can also be regarded as an assembly of multiple devices and / or apparatuses, whether functionally in cooperation with or independently of each other. Moreover, devices and apparatuses can be implemented in a distributed fashion throughout a system, so long as the functionality of the device or apparatus is preserved. Such and similar principles are considered known to a skilled person.

[0234] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0235] In addition, certain terms used in the present disclosure, including the specification and drawings, can be used synonymously in certain instances (e.g., “data” and “information. Althoughsuch terms may be used synonymously herein, there may be instances when such words are not intended to be used synonymously.

[0236] Embodiments described herein also include, but are not limited to, the following enumerated examples:

[0237] Al . A method for a user equipment (UE) configured for mobility between cells in a radio access network (RAN), the method comprising:

[0238] performing lower layer measurements on a plurality of beams associated with one or more mobility candidate cells;

[0239] determining that the lower layer measurements of a first subset of the plurality of beams fulfill one or more conditions for measurement reporting;

[0240] selecting a second subset of the plurality of beams whose lower layer measurements do not fulfill any conditions for measurement reporting; and

[0241] sending, to a RAN node that provides a serving cell for the UE, a measurement report comprising measurement values for the first subset of beams and measurement values for the second subset of beams.

[0242] Ala. The method of embodiment Al, wherein the measurement report further comprises, for each beam in the second subset, an explicit indication that the lower layer measurements for the beam did not fulfill any condition for measurement reporting.

[0243] A2. The method of any of embodiments Al -Al a, wherein the one or more mobility candidate cells are layer-l / layer-2 triggered mobility (LTM) candidate cells, the lower layer measurements are layer- 1 (LI) measurements, and the conditions for measurement reporting are associated with LI events.

[0244] A2a. The method of embodiment A2, further comprising receiving the following from the RAN node:

[0245] LTM candidate configurations for the respective one or more LTM candidate cells, and an LTM reporting configuration that identifies the following: the plurality of beams to be measured by the UE, and at least one of the conditions for LI measurement reporting.

[0246] A2b. The method of embodiment A2a, wherein:

[0247] the LTM reporting configuration identifies a plurality of LTM channel stateinformation (CSI) resources corresponding respectively to the plurality of beams to be measured, and

[0248] each of the plurality of LTM CSI resources identifies a reference signal (RS) associated with the corresponding beam and an LTM candidate cell associated with the RS.

[0249] A2c. The method of embodiment A2b, wherein the LTM reporting configuration further identifies which of the plurality of LTM CSI resources should fulfill each of the at least one condition for LI measurement reporting.

[0250] A3. The method of any of embodiments Al-A2c, wherein the second subset of beams is selected based on a size of the reported measurement values for the first subset being less than an allocated resource capacity for the measurement report.

[0251] A3a. The method of embodiment A3, wherein a number of beams in the second subset is zero when the size of the reported measurement values for the first subset is substantially equal to the allocated resource capacity for the measurement report.

[0252] A4. The method of any of embodiments Al-A3a, wherein the second subset of beams is selected based on the measurement values for beams of the second subset being at least a threshold value.

[0253] A4a. The method of embodiment A4, wherein a combined number of beams in the first and second subsets is less than a maximum number of beams that may be reported.

[0254] A4b. The method of embodiment A4, wherein the measurement values for one or more beams of the first subset are at least the threshold value.

[0255] A5. The method of any of embodiments Al-A4b, wherein one of the following applies: a number of beams (N) in the second subset is constant;

[0256] N is dependent on how many beams on which the lower layer measurements are performed; or

[0257] N is dependent on how many candidate cells on which the lower layer measurements are performed.A6. The method of any of embodiments A1-A5, wherein one or more beams of the second subset are selected based on being involved in an early synchronization of the UE with the associated mobility candidate cell.

[0258] A6a. The method of embodiment A6, wherein for each of the one or more beams, the early synchronization is one or more of the following: early uplink (UL) synchronization, or early downlink (DL) synchronization.

[0259] A6b. The method of any of embodiments A6-A6a. wherein one or more beams of the second subset are selected further based on their associated candidate cells being also associated with one or more beams of the first subset.

[0260] A7. The method of any of embodiments Al-A6b, wherein one or more beams of the second subset are selected based on being associated with a same mobility candidate cell as one or more beams of the first subset.

[0261] A8. The method of any of embodiments A1-A7, further comprising performing upper layer measurements on the plurality of beams associated with the one or more mobility candidate cells, wherein one or more beams of the second subset are selected based on their upper layer measurements fulfilling one or more conditions for upper layer measurement reporting.

[0262] A8a. The method of embodiment A8, wherein the lower layer measurements are layer- 1 (LI) measurements, and the upper layer measurements are layer-3 (L3) measurements that have been time-filtered.

[0263] A9. The method of any of embodiments Al-A8a, wherein one or more beams of the second subset are selected based on one or more of the following:

[0264] the UE having a valid timing advance for the associated candidate cell,

[0265] the UE having previously received a physical downlink control channel (PDCCH) order instructing the UE to transmit a random access preamble to the associated mobility candidate cell via the beam,

[0266] the UE having previously received a transmission configuration indicator (TCI) state activation command for the beam, and

[0267] the UE’s TCI state corresponding to the beam being activated.A10. The method of any of embodiments A1-A9, wherein one or more beams of the second subset are selected based on one or more of the following:

[0268] whether layer-2 (L2) reset is needed for the associated mobility candidate cell; whether a change of security is needed for the associated mobility candidate cell; whether the mobility candidate cell associated with the beam is both an non-conditional mobility candidate cell and a conditional mobility candidate cell;

[0269] whether the mobility candidate cell associated with the beam is both a layer- 1 (Ll) / L2 mobility candidate cell and a layer-3 (L3) mobility candidate cell; and frequency and / or subcarrier spacing of the associated mobility candidate cell.

[0270] All. The method of any of embodiments A1-A10, wherein one or more beams of the second subset are selected based on being associated with a same mobility candidate cell as one of the following: at least a minimum number of beams of the first subset, or no more than a maximum number of beams of the first subset.

[0271] Alla. The method of embodiment All, wherein the minimum number or the maximum number is one of the following: common to all of the mobility candidate cells, specific to each of the mobility candidate cells, or specific to each of the conditions for measurement reporting.

[0272] A12. The method of any of embodiments Al-Al la, wherein one or more beams of the second subset are selected such that measurement values for a same number of beams associated with each of the mobility candidate cells are included in the measurement report.

[0273] A13. The method of any of embodiments A1-A12, wherein one or more beams of the second subset are selected based on one or more of the following being configured for the UE in the associated mobility candidate cells: contention-free random access (CFRA) resources, and a grant of uplink resources.

[0274] A14. The method of any of embodiments Al -Al 3, wherein one or more beams of the second subset are selected based on one of the following:

[0275] a maximum ratio or percentage of a total number of beams in the second subset relative to a total number of beams having measurement values included in the measurement report; and

[0276] a random selection algorithm.Bl. User equipment (UE) configured for mobility between cells in a radio access network (RAN), the UE comprising:

[0277] communication interface circuitry configured to communicate with RAN nodes; and processing circuitry operatively coupled to the communication interface circuitry, wherein the processing circuitry and the communication interface circuitry are configured to perform operations corresponding to the methods of any of embodiments A1-A14.

[0278] B2. User equipment (UE) configured for mobility between cells in a radio access network (RAN), the UE being further configured to perform operations corresponding to the methods of any of embodiments A1-A14.

[0279] B3. Non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of user equipment (UE) configured for mobility between cells in a radio access network (RAN), configure the UE to perform operations corresponding to the methods of any of embodiments A1-A14.

[0280] B4. Computer program product comprising computer-executable instructions that, when executed by processing circuitry of user equipment (UE) configured for mobility between cells in a radio access network (RAN), configure the UE to perform operations corresponding to the methods of any of embodiments A1-A14.

Claims

CLAIMS1. A method for a user equipment, UE, configured for mobility between cells in a radio access network, RAN, the method comprising:performing (720) lower layer measurements on a plurality of beams associated with one or more mobility candidate cells;determining (730) that the lower layer measurements of a first subset of the plurality of beams fulfill one or more conditions that trigger measurement reporting; selecting (750) a second subset of the plurality of beams whose lower layer measurements do not fulfill the one or more conditions that trigger measurement reporting, wherein each beam of the second subset is selected based on one or more of the following:a measurement value being at least a threshold value,being involved in an early synchronization of the UE with the mobility candidate cell associated with the beam,being associated with a same mobility candidate cell as one or more beams of the first subset; andsending (760), to a RAN node that provides a serving cell for the UE, a measurement report comprising measurement values for the first subset of beams and measurement values for the second subset of beams.

2. The method of claim 1, wherein the measurement report further comprises, for each beam in the second subset, an explicit indication that the lower layer measurements for the beam did not fulfill any condition that trigger measurement reporting.

3. The method of any of claims 1-2, wherein the second subset of beams is selected further based on a size of the reported measurement values for the first subset being less than an allocated resource capacity for the measurement report.

4. The method of claim 3, wherein a number of beams in the second subset is zero when the size of the reported measurement values for the first subset is substantially equal to the allocated resource capacity for the measurement report.

5. The method of any of claims 1-4, wherein one or more of the following applies:45a total number of beams in the first and second subsets is less than a maximum number of beams that may be reported; andthe measurement values for one or more beams of the first subset are at least the threshold value.

6. The method of any of claims 1-5, wherein the threshold value is for one of the following: reference signal received power, RSRP; reference signal received quality, RSRQ; signal-to-interference-and-noise ratio, SINR; and received signal strength, RSSI.

7. The method of any of claims 1-6, wherein a total number of beams in the second subset is one of the following: constant, based on how many beams on which the lower layer measurements are performed, or based on how many mobility candidate cells on which the lower layer measurements are performed.

8. The method of any of claims 1-7, wherein one or more beams of the second subset are selected based on being involved in one or more of the following: early uplink synchronization, and early downlink synchronization.

9. The method of any of claims 1-8, further comprising performing (730) upper layer measurements on the plurality of beams associated with the one or more mobility candidate cells, wherein one or more beams of the second subset are selected further based on their upper layer measurements fulfilling one or more further conditions that trigger upper layer measurement reporting.

10. The method of claim 9, wherein the lower layer measurements are layer-1 measurements, and the upper layer measurements are layer-3 measurements that have been time-filtered.

11. The method of any of claims 1-10, wherein one or more beams of the second subset are selected further based on one or more of the following:the UE having a valid timing advance for the associated candidate cell,the UE having previously received a physical downlink control channel, PDCCH, order instructing the UE to transmit a random access preamble via the beam to the associated mobility candidate cell,the UE having previously received a transmission configuration indicator, TCI, state activation command for the beam, and46the UE’s TCI state corresponding to the beam being activated.

12. The method of any of claims 1-11, wherein one or more beams of the second subset are selected further based on one or more of the following:whether layer-2 reset is needed for the associated mobility candidate cell; whether a change of security is needed for the associated mobility candidate cell; whether the mobility candidate cell associated with the beam is both an nonconditional mobility candidate cell and a conditional mobility candidate cell; whether the mobility candidate cell associated with the beam is both a layer- l / layer-2 mobility candidate cell and a layer-3 mobility candidate cell; and frequency and / or subcarrier spacing of the associated mobility candidate cell.

13. The method of any of claims 1-12, wherein one or more beams of the second subset are selected further based on being associated with a same mobility candidate cell as one of the following: at least a minimum number of beams of the first subset, or no more than a maximum number of beams of the first subset.

14. The method of claim 13, wherein the minimum number or the maximum number is one of the following: common to all of the mobility candidate cells, specific to each of the mobility candidate cells, or specific to each of the conditions that trigger measurement reporting.

15. The method of any of claims 1-14, wherein one or more beams of the second subset are selected further based on a condition that the measurement report include measurement values for a same number of beams associated with each of the one or more mobility candidate cells.

16. The method of any of claims 1-15, wherein one or more beams of the second subset are selected further based on one or more of the following being configured for the UE in the associated mobility candidate cells: contention-free random access resources, and a grant of uplink resources.

17. The method of any of claims 1-16, wherein one or more beams of the second subset are selected further based on one of the following:a maximum ratio or percentage of a total number of beams in the second subset relative to a total number of beams having measurement values included in the measurement report; and47a random selection algorithm.

18. User equipment, UE (210, 510, 812, 900) configured for mobility between cells in a radio access network, RAN (199, 904), the UE comprising:communication interface circuitry (912) configured to communicate with RAN nodes (220, 520, 810); andprocessing circuitry (902) operatively coupled to the communication interface circuitry, wherein the processing circuitry and the communication interface circuitry are configured to:perform lower layer measurements on a plurality of beams associated with one or more mobility candidate cells;determine that the lower layer measurements of a first subset of the plurality of beams fulfill one or more conditions that trigger measurement reporting; select a second subset of the plurality of beams whose lower layer measurements do not fulfill the one or more conditions that trigger measurement reporting, wherein each beam of the second subset is selected based on one or more of the following:a measurement value being at least a threshold value, being involved in an early synchronization of the UE with the mobility candidate cell associated with the beam,being associated with a same mobility candidate cell as one or more beams of the first subset; andsend, to a RAN node that provides a serving cell for the UE, a measurement report comprising measurement values for the first subset of beams and measurement values for the second subset of beams.

19. The UE of claim 18, wherein the processing circuitry and the communication interface circuitry are further configured to perform operations corresponding to the methods of any of claims 2-17.

20. User equipment, UE (210, 510, 812, 900) configured for mobility between cells in a radio access network, RAN (199, 904), the UE being further configured to:perform lower layer measurements on a plurality of beams associated with one or more mobility candidate cells;determine that the lower layer measurements of a first subset of the plurality of beams fulfill one or more conditions that trigger measurement reporting;select a second subset of the plurality of beams whose lower layer measurements do not fulfill the one or more conditions that trigger measurement reporting, wherein each beam of the second subset is selected based on one or more of the following:a measurement value being at least a threshold value,being involved in an early synchronization of the UE with the mobility candidate cell associated with the beam,being associated with a same mobility candidate cell as one or more beams of the first subset; andsend, to a RAN node (220, 520, 810) that provides a serving cell for the UE, a measurement report comprising measurement values for the first subset of beams and measurement values for the second subset of beams.

21. The UE of claim 20, being further configured to perform operations corresponding to the methods of any of claims 2-17.

22. Non-transitory, computer-readable medium (910) storing computer-executable instructions that, when executed by processing circuitry (902) of user equipment, UE (210, 510, 812, 900) configured for mobility between cells in a radio access network, RAN (199, 904), configure the UE to perform operations corresponding to the methods of any of claims 1-17.

23. Computer program product (914) comprising computer-executable instructions that, when executed by processing circuitry (902) of user equipment, UE (210, 510, 812, 900) configured for mobility between cells in a radio access network, RAN (199, 904), configure the UE to perform operations corresponding to the methods of any of claims 1-17.

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