Lower-layer triggered mobility (LTM) event evaluation in multi-transmission-reception point (multi-TRP) operation

Abstract

A method is provided that includes operating with a configuration including at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell. The method includes receiving a reporting configuration for event-triggered layer 1 measurement reporting. The method includes determining a reference resource quality based on at least one reference signal (RS) resource of respective RS resources associated with the at least two indicated TCI states. The method includes determining that a reporting event of the reporting configuration is fulfilled based on at least the reference resource quality. And the method includes sending a measurement report triggered by the determination to the serving cell.

Description

LOWER-LAYER TRIGGERED MOBILITY (LTM) EVENT EVALUATION IN MULTI-TRANSMISSION-RECEPTION POINT (MULTLTRP) OPERATIONTECHNOLOGICAL FIELD

[0001] The present disclosure relates generally to telecommunications and, in particular, to layer 1 measurement reporting in a telecommunications system.BACKGROUND

[0002] A telecommunications system can be seen as a facility that enables communication sessions between two or more entities such as user terminals, base stations and / or other nodes by providing carriers between the various entities involved in the communications path. A telecommunications system can be provided for example by means of a communication network and one or more compatible communication devices. The communication sessions may comprise, for example, communication of data for carrying communications such as voice, video, electronic mail (email), text message, multimedia and / or content data and so on. Non-limiting examples of services provided comprise two-way or multi-way calls, data communication or multimedia services and access to a data network system, such as the Internet.

[0003] In a wireless telecommunications system, at least a part of a communication session between at least two stations occurs over a wireless link. Examples of wireless telecommunications systems comprise public land mobile networks (PLMN), satellite based communication systems and different wireless local networks, for example wireless local area networks (WLAN). Some wireless systems can be divided into cells, and are therefore often referred to as cellular systems.

[0004] A user can access the telecommunications system by means of an appropriate communication device or terminal. A communication device of a user may be referred to as user equipment (UE) or user device. A communication device is provided with an appropriate signal receiving and transmitting apparatus for enabling communications, for example enabling access to a communication network or communications directly with other users. The communication device may access a carrier provided by a station, for example a base station of a cell, and transmit and / or receive communications on the carrier.

[0005] The telecommunications system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entities associated with the communication system are permitted to do and how operations should be achieved. Communication protocols and / or parameters which shall be used for connection of the various entities are also typically defined. One example of a telecommunications system is the Universal Mobile Telecommunications System (UMTS). Other examples of telecommunications systems are Long-Term Evolution (LTE), LTE Advanced and the so- called 5G or New Radio (NR) networks. NR is being standardized by the 3rd Generation Partnership Project (3 GPP).BRIEF SUMMARY

[0006] Example implementations of the present disclosure are directed to telecommunications and, in particular, to layer 1 measurement reporting in a telecommunications system. The present disclosure includes, without limitation, the following example implementations.

[0007] Some example implementations provide an apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: operate with a configuration including at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; receive a reporting configuration for event-triggered layer 1 measurement reporting; determine a reference resource quality based on at least one reference signal (RS) resource of respective RS resources associated with the at least two indicated TCI states; determine that a reporting event of the reporting configuration is fulfilled based on at least the reference resource quality; and send a measurement report triggered by the determination to the serving cell.

[0008] Some example implementations provide an apparatus comprising: means for operating with a configuration including at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; means for receiving a reporting configuration for event-triggered layer 1 measurement reporting; means for determining a reference resource quality based on at least one reference signal (RS) resource of respective RS resources associated with the at least two indicated TCI states;means for determining that a reporting event of the reporting configuration is fulfilled based on at least the reference resource quality; and means for sending a measurement report triggered by the determination to the serving cell.

[0009] Some example implementations provide a method comprising: operating with a configuration including at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; receiving a reporting configuration for event-triggered layer 1 measurement reporting; determining a reference resource quality based on at least one reference signal (RS) resource of respective RS resources associated with the at least two indicated TCI states; determining that a reporting event of the reporting configuration is fulfilled based on at least the reference resource quality; and sending a measurement report triggered by the determination to the serving cell.

[0010] Some example implementations provide a computer-readable storage medium that is non-transitory and has instructions stored therein that, in response to execution by at least one processing circuitry, causes an apparatus to at least: operate with a configuration including at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; receive a reporting configuration for event-triggered layer 1 measurement reporting; determine a reference resource quality based on at least one reference signal (RS) resource of respective RS resources associated with the at least two indicated TCI states; determine that a reporting event of the reporting configuration is fulfilled based on at least the reference resource quality; and send a measurement report triggered by the determination to the serving cell.

[0011] Some example implementations provide an apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: configure a user equipment (UE) with at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; send a reporting configuration to the UE for event-triggered layer 1 measurement reporting, the reporting configuration including an indication of at least one of the at least two indicated TCI states; receive a measurement report triggered by a determination at the UE that a reporting event of the reporting configuration is fulfilled based on at least a reference resource quality determined based on at least one respective reference signal (RS) resource associated with theat least one of the at least two indicated TCI states; and make a determination whether to initiate an early synchronization or cell switch procedure toward a candidate cell, or whether to change one or more indicated beams for beam management, based on the measurement report.

[0012] Some example implementations provide an apparatus comprising: means for configuring an user equipment (UE) with at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; means for sending a reporting configuration to the UE for event-triggered layer 1 measurement reporting, the reporting configuration including an indication of at least one of the at least two indicated TCI states; means for receiving a measurement report triggered by a determination at the UE that a reporting event of the reporting configuration is fulfilled based on at least a reference resource quality determined based on at least one respective reference signal (RS) resource associated with the at least one of the at least two indicated TCI states; and means for making a determination whether to initiate an early synchronization or cell switch procedure toward a candidate cell, or whether to change one or more indicated beams for beam management, based on the measurement report.

[0013] Some example implementations provide a method comprising: configuring a user equipment (UE) with at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; sending a reporting configuration to the UE for event-triggered layer 1 measurement reporting, the reporting configuration including an indication of at least one of the at least two indicated TCI states; receiving a measurement report triggered by a determination at the UE that a reporting event of the reporting configuration is fulfilled based on at least a reference resource quality determined based on at least one respective reference signal (RS) resource associated with the at least one of the at least two indicated TCI states; and making a determination whether to initiate an early synchronization or cell switch procedure toward a candidate cell, or whether to change one or more indicated beams for beam management, based on the measurement report.

[0014] Some example implementations provide a computer-readable storage medium that is non-transitory and has instructions stored therein that, in response to execution by at least one processing circuitry, causes an apparatus to at least: configure a user equipment (UE) with at least two indicated transmission configuration indicator (TCI) states to be applied to at leastone downlink channel in a serving cell; send a reporting configuration to the UE for event- triggered layer 1 measurement reporting, the reporting configuration including an indication of at least one of the at least two indicated TCI states; receive a measurement report triggered by a determination at the UE that a reporting event of the reporting configuration is fulfilled based on at least a reference resource quality determined based on at least one respective reference signal (RS) resource associated with the at least one of the at least two indicated TCI states; and make a determination whether to initiate an early synchronization or cell switch procedure toward a candidate cell, or whether to change one or more indicated beams for beam management, based on the measurement report.

[0015] These and other features, aspects, and advantages of the present disclosure will be apparent from a reading of the following detailed description together with the accompanying figures, which are briefly described below. The present disclosure includes any combination of two, three, four or more features or elements set forth in this disclosure, regardless of whether such features or elements are expressly combined or otherwise recited in a specific example implementation described herein. The present disclosure is intended to be read holistically such that any separable features or elements of the disclosure, in any of its aspects and example implementations, should be viewed as combinable unless the context of the disclosure clearly dictates otherwise.

[0016] It will therefore be appreciated that this Brief Summary is provided merely for purposes of summarizing some example implementations so as to provide a basic understanding of some aspects of the disclosure. Accordingly, it will be appreciated that the above described example implementations are merely examples and should not be construed to narrow the scope or spirit of the disclosure in any way. Other example implementations, aspects and advantages will become apparent from the following detailed description taken in conjunction with the accompanying figures which illustrate, by way of example, the principles of some described example implementations.BRIEF DESCRIPTION OF THE FIGURE(S)

[0017] Having thus described example implementations of the disclosure in general terms, reference will now be made to the accompanying figures, which are not necessarily drawn to scale, and wherein:

[0018] FIG. 1 illustrates a telecommunications system that includes one or more public land mobile networks (PLMNs) coupled to one or more external data networks, according to some example implementations of the present disclosure;

[0019] FIG. 2 illustrates a 5G deployment of a PLMN, according to some example implementations;

[0020] FIG. 3 is a signaling chart for a Ll / L2-triggered mobility, also known as lower- layer triggered mobility (LTM) procedure, according to some example implementations;

[0021] FIGS. 4A and 4B illustrate a signaling chart for an LTM procedure in a CU-DU split architecture, according to some example implementations;

[0022] FIGS. 5 and 6 are flowcharts illustrating various steps in respective methods according to various example implementations; and

[0023] FIG. 7 illustrates an apparatus according to some example implementations.DETAILED DESCRIPTION

[0024] Some implementations of the present disclosure will now be described more fully hereinafter with reference to the accompanying figures, in which some, but not all implementations of the disclosure are shown. Indeed, various implementations of the disclosure may be embodied in many different forms and should not be construed as limited to the implementations set forth herein; rather, these example implementations are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Like reference numerals refer to like elements throughout.

[0025] Unless specified otherwise or clear from context, references to first, second or the like should not be construed to imply a particular order. A feature described as being above another feature (unless specified otherwise or clear from context) may instead be below, and vice versa; and similarly, features described as being to the left of another feature else may instead be to the right, and vice versa. Also, while reference may be made herein to quantitative measures, values, geometric relationships or the like, unless otherwise stated, any one or more if not all of these may be absolute or approximate to account for acceptable variations that may occur, such as those due to engineering tolerances or the like.

[0026] As used herein, unless specified otherwise or clear from context, the “or” of a set of operands is the “inclusive or” and thereby true if and only if one or more of the operands istrue, as opposed to the “exclusive or” which is false when all of the operands are true. Thus, for example, “[A] or [B]” is true if [A] is true, or if [B] is true, or if both [A] and [B] are true. Further, the articles “a” and “an” mean “one or more,” unless specified otherwise or clear from context to be directed to a singular form. Furthermore, it should be understood that unless otherwise specified, the terms “data,” “content,” “digital content,” “information,” and similar terms may be at times used interchangeably. The term “network” may refer to a group of interconnected computers including clients and servers; and within a network, these computers may be interconnected directly or indirectly by various means including via one or more switches, routers, gateways, access points or the like.

[0027] Reference may be made herein to terms specific to a particular system, architecture or the like, but it should be understood that example implementations of the present disclosure may be equally applicable to any of a number of systems, architectures and the like. For example, reference may be made to 3 GPP technologies such as Global System for Mobile Communications (GSM), UMTS, LTE, LTE Advanced, 5GNR, 5G Advanced and 6G; however, it should be understood that example implementations of the present disclosure may be equally applicable to non-3GPP technologies such as IEEE 802, Bluetooth and Bluetooth Low Energy.

[0028] Further, as used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry); (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions); or (c) hardware circuit(s) and / or processor(s), such as a microprocessor(s) or a portion of a microprocessor s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0029] The above definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanyingsoftware and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0030] FIG. 1 illustrates a telecommunications system 100 according to various example implementations of the present disclosure. The telecommunications system generally includes one or more telecommunications networks. As shown, for example, the system includes one or more public land mobile networks (PLMNs) 102 coupled to one or more other external data networks 104 - notably including a wide area network (WAN) such as the Internet. Each of the PLMNs includes a core network (CN) 106 backbone such as the Evolved Packet Core (EPC) of LTE, the 5G core network (5GC) or the like; and each of the core networks and the Internet are coupled to one or more radio access networks (RANs) 108, air interfaces or the like that implement one or more radio access technologies (RATs). As used herein, a “network device” refers to any suitable device at a network side of a telecommunications network. Examples of suitable network devices are described in greater detail below.

[0031] In addition, the system includes one or more radio units that may be varyingly known as user equipment (UE) 110, terminal device, terminal equipment, mobile station or the like. The UE is generally a device configured to communicate with a network device or a further UE in a telecommunications network. The UE may be a portable computer (e.g., laptop, notebook, tablet computer), mobile phone (e.g., cell phone, smartphone), wearable computer (e.g., smartwatch), or the like. In other examples, the UE may be an Internet of things (loT) device, an industrial loT (IIoT device), a vehicle equipped with a vehicle-to- everything (V2X) communication technology, or the like. In some examples, as referenced by 3GPP, the UE may be a narrowband loT (NB-IoT) device, an enhanced machine-type communication (eMTC) device, a reduced capability (RedCap) device, an ambient loT device, or the like.

[0032] In operation, these UEs 110 may be configured to connect to one or more of the RANs 108 according to their particular radio access technologies to thereby access a particular CN 106 of a PLMN 102, or to access one or more of the external data networks 104 (e.g., the Internet). The external data network may be configured to provide Internet access, operator services, 3rd party services, etc. For example, the International Telecommunication Union(ITU) has classified 5G mobile network services into three categories: enhanced mobile broadband (eMBB), ultra-reliable and low-latency communications (URLLC), and massive machine type communications (mMTC) or massive internet of things (MIoT).

[0033] Examples of radio access technologies include 3 GPP radio access technologies such as GSM, UMTS, LTE, LTE Advanced, 5GNR, 5G Advanced, and 6G. Other examples of radio access technologies include IEEE 802 technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.15 (including 802.15.1 (WPAN / Bluetooth), 802.15.4 (Zigbee) and 802.15.6 (WBAN)), Bluetooth, Bluetooth Low Energy (BLE), ultra wideband (UWB), and the like. Generally, a radio access technology may refer to any 2G, 3G, 4G, 5G, 6G or higher generation mobile communication technology and their different versions, as well as to any other wireless radio access technology that may be arranged to interwork with such a mobile communication technology to provide access to the CN 106 of a mobile network operator (MNO).

[0034] In various examples, a RAN 108 may be configured as one or more macrocells, microcells, picocells, femtocells or the like. The RAN may generally include one or more radio access nodes that are configured to interact with UEs 110. In various examples, a radio access node may be referred to as a base station (BS), access point (AP), base transceiver station (BTS), Node B (NB), evolved NB (eNB), macro BS, NB (MNB) or eNB (MeNB), home BS, NB (HNB) or eNB (HeNB), next generation NB (gNB), enhanced gNB (en-gNB), next generation eNB (ng-eNB), or the like. The RAN may include some type of network controlling / governing entity responsible for control of the radio access nodes. The network controlling / governing entity and radio access node may be separate or integrated into a single apparatus. The network controlling / governing entity may include processing circuity configured to carry out various management functions, etc. The processing circuity may be associated with a memory, computer-readable storage medium or database for maintaining information required in the management functions.

[0035] ARAN 108 may be centralized or distributed. In various examples, components of a RAN may be interconnected by Ethernet, Gigabit Ethernet, Asynchronous Transfer Mode (ATM), optical fiber, dark fiber, passive wavelength division multiplexing (WDM), WDM passive optical network (WDM-PON), optical transport network (OTN), time sensitive networking (TSN) and / or any other data link layer network, possibly including radio links.The RAN may be connected to a CN 106 through one or more gateways, network functions or the like.

[0036] As will be appreciated, a PLMN 102 may be deployed in a number of different manners. In a 4GLTE deployment, the EPC is the CN 106, and the evolved UMTS terrestrial radio access network (E-UTRAN) is the RAN 108; and the E-UTRAN includes one or more eNBs (radio access nodes) configured to connect UEs 110 to the E-UTRAN to thereby access the EPC. As shown in FIG. 2, in a 5G deployment 200, the 5GC 202 is the CN, and the next generation (NG) radio access network (NG-RAN) 204 is the RAN; and the NG-RAN includes one or more gNBs 206 (radio access nodes) configured to connect UEs 110 to the NG-RAN to thereby access the 5GC (at times referred to as the NGC). The term ‘gNB’ in 5G may correspond to the eNB in 4G LTE.

[0037] Some deployments of 4G LTE and 5G in particular are considered standalone (SA) deployments. Other deployments combine 4G LTE and 5 G technologies, and are referred to as non-standalone (NSA) deployments. In some deployments, the E-UTRAN includes one or more ng-eNBs that are configured to communicate with the 5GC, and that may also be configured to communicate with one or more gNBs. Similarly, in another deployment, the NG-RAN may include one or more en-gNBs that are configured to communicate with the EPC, and that may also be configured to communicate with one or more eNBs. In various instances, a single UE 110, a dual -mode or multimode UE, may support multiple (two or more) RANs — thereby being configured to connect to multiple RANs, such as 4G LTE and 5G.

[0038] In some deployments, operations of a gNB 206 or other radio access node may be distributed or functionally split into components including one or more remote radio head (RRHs) or radio units (RUs) 208, and a baseband unit (BBU); and in some architectures, the BBU may be split into a distributed unit (DU) 210 and a central / centralized unit (CU) 212, such as a server, host or node. In some architectures, the RRH / RU and DU may be co-located. It is also possible that node operations may be distributed among a plurality of servers, hosts or nodes. It should also be understood that the distribution of work between CN operations and radio access node operations may vary depending on implementation.

[0039] As shown and described, for example, some 5G deployments may be based on a so-called CU-DU split including one or more DUs 210 and a CU 212. One gNB-CU (centralnode) may control one or more gNB-DUs. The gNB-CU may control a plurality of spatially separated gNB-DUs, acting at least as transmit / receive (Tx / Rx) nodes. In some example implementations, however, the gNB-DUs (also called DU) may include, for example, a radio link control (RLC), medium access control (MAC) layer and a physical (PHY) layer, whereas the gNB-CU (also called a CU) may include the layers above the RLC layer, such as a packet data convergence protocol (PDCP) layer, a radio resource control (RRC), and an internet protocol (IP) layer. Other functional splits are also possible. It is considered that a skilled person is familiar with the open systems interconnection (OSI) model and the functionalities within each layer.

[0040] In some example implementations, the server or CU 212 may generate a virtual network through which the server communicates with the radio node. In general, virtual networking may involve a process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. Such virtual network may provide flexible distribution of operations between the server and the radio head / node. In practice, any digital signal processing task may be performed in either the CU or the DU 210, and the boundary where the responsibility is shifted between the CU and the DU may be selected according to implementation.

[0041] In various instances, a UE 110 may be configured to operate using multiple antenna panels or beams, such as via multiple input, multiple output (MIMO) technology, which may allow the UE to dramatically increase its data rate capabilities. One feature related to this capability is referred to as multi-TRP (transmission-reception point). This feature enables the network to use multiple TRPs to communicate with a UE. In this regard, a TRP may be a set of geographically co-located antennas, antenna arrays or panels supporting transmission point (TP) and / or reception point (RP) functionality. In various examples, TRPs may be radio access nodes (e.g., gNBs 206, ng-eNBs), radio access node antennas, antenna arrays or panels, RRHs, RUs 208, a remote antenna, antenna array or panel of a radio access node, or the like.

[0042] In multi-TRP operation, a serving cell of a radio access node 202 may schedule the UE 110 from two TRPs, providing better coverage, reliability and / or data rates for the physical downlink shared channel (PDSCH), physical downlink control channel (PDCCH), physical uplink shared channel (PUSCH), and physical uplink control channel (PUCCH).

[0043] There are two different operation modes to schedule multi-TRP PDSCH transmissions based on downlink control information (DCI), namely, single-DCI and multi- DCI. For both modes, control of uplink (UL) and downlink (DL) operation may be implemented at the PHY and MAC layers, within a configuration provided by the RRC layer. In single-DCI mode, the UE 110 may be scheduled by the same DCI for both TRPs; and in multi-DCI mode, the UE may be scheduled by independent DCIs from each TRP

[0044] There are two different operation modes for multi-TRP PDCCH, namely, PDCCH repetition and single frequency network (SFN) based PDCCH transmission. In both modes, the UE 110 may receive two PDCCH transmissions, one from each TRP, carrying the same DCI. In PDCCH repetition mode, the UE may receive the two PDCCH transmissions carrying the same DCI from two linked search spaces each associated with a different control resource set (CORESET). In SFN based PDCCH transmission mode, the UE may receive the two PDCCH transmissions carrying the same DCI from a single search space / CORESET using different TCI states.

[0045] For multi-TRP PUSCH repetition, according to indications in a single DCI or in a semi-static configured grant provided over RRC, the UE 110 may perform PUSCH transmission of the same contents toward two TRPs with corresponding beam directions associated with different spatial relations. For multi-TRP PUCCH repetition, the UE may perform PUCCH transmission of the same contents toward two TRPs with corresponding beam directions associated with different spatial relations.

[0046] For inter-cell multi-TRP operation, for multi-DCI PDSCH transmission, one or more TCI states may be associated with synchronization signal blocks (SSBs) with a physical cell identifier (PCI) different from the serving cell PCI. The activated TCI states may be associated with at most one PCI different from the serving cell PCI at a time. As used herein, a SSB may be a synchronization signal (SS) / physical broadcast channel (PBCH) block.

[0047] For inter-cell and intra-cell multi-DCI multi-TRP operation, up to two timing advance groups (TAGs) with associated TAG IDs may be configured per serving cell. Each UL / joint TCI state may be associated with a TAG ID, and the UE 110 may apply the timing advance of the TAG ID associated with the UL / joint TCI state utilized for UL transmission.

[0048] For single-DCI multi-TRP simultaneous transmission with multi-panel (STxMP) spatial domain multiplexing (SDM) PUSCH transmission, different layers of one PUSCH maybe separately transmitted towards two TRPs. For single-DCI multi-TRP STxMP SFN PUSCH transmission, the same layers of one PUSCH may be transmitted towards two TRPs. For multi-DCI based multi-TRP STxMP PUSCH+PUSCH transmission, two PUSCHs may be transmitted towards two TRPs. For single-DCI multi-TRP STxMP SFN PUCCH transmission, one PUCCH may be transmitted towards two TRPs.

[0049] A unified TCI state framework may be used for beam indication; and in an extension of the framework, the UE may be configured with two (or more) indicated TCI states. For example, the indicated TCI states may be applied to PDCCH monitoring (the indicated TCI states may also be applied to other channels PDSCH PUCCH PUSCH).

[0050] Also consider a scenario in which a UE 110 is provided with TCI states for DL or joint DL / UL transmission (dl-OrJointTCI-StateList), indicated a first TCI state (TCI-State) and a second TCI state (TCI-State), and provided a configuration (apply -IndicatedTCI State) to apply an indicated TCI state for a CORESET, other than a CORESET with index 0, and the CORESET is associated only with user-specific search space (USS) sets and / or Type3- PDCCH common search space (CSS) sets. If the configuration is for the UE to apply the first TCI state (apply-IndicatedTCIState = ‘first’), the UE may assume that a demodulation reference signal (DM-RS) antenna port for PDCCH receptions in the CORESET is quasi colocated with the reference signals (RSs) provided by the first TCI state. Similarly, the configuration is for the UE to apply the second TCI state (apply-IndicatedTCIState = ‘second’), the UE may assume that a DM-RS antenna port for PDCCH receptions in the CORESET is quasi co-located with the reference signals (RSs) provided by the second TCI state. And if the configuration is for the UE to apply the both the first TCI state and the second TCI state (apply-IndicatedTCIState = ‘both’), the UE may assume that a DM-RS antenna port for PDCCH receptions in the CORESET is quasi co-located with the reference signals provided by the TCI state and the second TCI state.

[0051] The above is also applicable to CORSET other than a CORESET with index 0, and the CORESET is associated with CSS sets other than Type3-PDCCH CSS sets. This also applicable to CORESET with index 0 except for a CORESET with index 0 which is associated with a Type 0 / 0A / 2-PDCCH CSS set that has search space set index 0, a configuration that allows for the UE to apply the both the first TCI state and the second TCI state may not be applicable. Also, for a CORESET with index 0 and CORSET other than a CORESET withindex 0 associated with CSS sets other than Type3-PDCCH CSS sets, if the configuration is for the UE to apply the ‘none’ TCI state (apply-IndicatedTCIState = 'none'), the UE may assume that a DM-RS antenna port for PDCCH receptions in the CORESET is quasi colocated with the one or more DL RS configured by a TCI state, where the TCI state is indicated by a MAC CE activation command for the CORESET, if any. The above rules may be applied for single-DCI based multi- TRP transmissions. For multi-DCI based multi-TRP transmissions, a CORSET is configured to be associated with a specific CORESET pool index (0 or 1), and the TCI state for a CORSET is determined from the indicated TCI state associated to the same CORSET pool index associated with the CORESET.

[0052] Currently in 3 GPP, mainstream mobility has been conducted using higher layer (L3 or RRC controlled) mobility. In this regard, L3 handover based mobility is a well-known and proven method for ensuring a robust way of handing over the UE 110 from one serving cell (source cell) of a radio access node 202 to a new serving cell (target cell) of the same or another radio access node. The method has been used at least since GSM and is still in use in 5G NR. It is expected that L3 mobility (legacy handover) will also be commonly used in the future.

[0053] Ll / L2-triggered mobility, or lower-layer triggered mobility (LTM) moves the execution of the ‘handover’ from one cell to another from higher layers (L3), such as RRC, to lower layers. These lower layers may be either PHY (or LI) or MAC (or L2). LTM may reduce latency, overhead and interruption time when compared to L3 handover based mobility. In a CU-DU split architecture, LTM may support one or more of intra-DU mobility, intra-CU inter-DU mobility, or inter-CU inter-DU mobility.

[0054] FIG. 3 illustrates a signaling chart 300 for an LTM procedure of a UE 110 in a RRC connected state with a gNB 206, which has been proposed. During LTM preparation, as shown at step 301, the UE sends a L3 measurement report to the gNB, which decides to use LTM and initiate LTM candidate preparation. The gNB at step 302 transmits a RRC reconfiguration message to the UE, including the configuration of one or more candidate target cells. The RRC reconfiguration message may also include a configuration of LI measurement reporting for LTM execution. The UE stores the configurations, and the UE at step 303 transmits a RRC reconfiguration complete message to the gNB.

[0055] An early synchronization of the UE 110 with the candidate target cell(s) follows LTM preparation. As shown at step 304, the UE 110 performs downlink (DL) / uplink (UL) synchronization with the candidate target cell(s). During this procedure, the UE may acquire a timing advance (TA) of respective ones of the candidate target cell(s). This early synchronization may reduce interruption during LTM execution, as compared to L3 handover based mobility. In this regard, the TA may be used to control the timing of uplink transmissions of a UE toward the candidate target cell(s). The UE may likewise have an acquired TA of the cell of the gNB to control the timing of uplink transmissions toward the gNB.

[0056] During LTM execution, the UE 110 performs LI measurements on the configured candidate target cell(s), and the UE at step 305 transmits LI measurement reports to the gNB 206. The gNB decides to execute a cell switch, and selects one of the candidate target cell(s) as a target cell for the cell switch. The gNB then at step 306 transmits a cell switch command, such as a MAC control element (MAC-CE), to trigger cell switch. The UE switches to the configuration of the target cell; and if the TA of the target cell (from step 304) is no longer available, the UE at step 307 initiates a random access channel (RACH) procedure with the target cell to acquire the TA of the target cell. The UE then at step 308 indicates successful completion of the cell switch.

[0057] FIGS. 4A and 4B illustrate a signaling chart 400 for an LTM procedure in a CU- DU split architecture, including a CU 212, a source DU (S-DU) 210Afor a serving cell, and a target DU (T-DU) 210B for a target cell. During preparation for LTM, as shown at steps 401 and 402, the UE 110 sends a L3 measurement report to the CU via the S-DU, and the CU at step 403 decides prepare one or more candidate target cells (DUs) for LTM. As shown at steps 404, 405, 406 and 407, the CU proceeds with the UE context setup / modification procedures. At step 408, the CU generates RRC reconfiguration(s) for the configured candidate target cell(s); and at steps 409 and 410, the CU provides the configurations to the UE 110 via the S- DU.

[0058] At steps 408, 409 and 410, the CU 212 also configures the UE 110 with LI measurement reporting for LTM execution. The CU provides the S-DU 210A with TA acquisition triggering criteria and configuration(s), as well as cell switch triggering criteria and configuration(s). The triggering criteria for TA acquisition and cell switch may be similar tomeasurement event report triggering conditions, e.g., A3, A4 or A5 event conditions or validity of acquired TA. The triggering conditions may include, for example, a filter configuration (for LI measurements), trigger offsets, cell individual offsets, or the like.

[0059] At steps 411 and 412, the UE 110 sends a RRC reconfiguration complete to the CU 212 via the S-DU 210A.

[0060] During execution, at step 413 onwards, the UE 110 performs LI measurements on the configured candidate target cell(s), and transmits LI measurement reports to the S-DU 210A. The S-DU at step 414 decides to trigger the TA acquisition of the candidate target cell(s) (including the cell of T-DU 210B), and the S-DU at step 415 transmits a TA acquisition command to the UE. The UE at step 416 transmits a random access preamble to the candidate target cell(s) (T-DU 210B / cell) to signal the candidate target cell(s) to estimate the TA between the UE and the candidate target cell(s). And at step 417, the S-DU 210A / cell receives a random access response (RAR) from respective ones of the candidate target cell(s) indirectly via the CU 212. Alternatively, the UE may receive the RAR of respective ones of the candidate target cell(s), indirectly via the CU and the S-DU.

[0061] The UE 110 at step 418 transmits LI beam measurements of the candidate target cell(s) to the S-DU 210A. The S-DU at steps 419 and 420 decides to initiate a cell change to the T-DU 210B / cell, and transmits a cell switch command (e.g., MAC-CE) to trigger the cell switch. In examples in which the RAR is received at the S-DU at step 417 (instead of the UE), the S-DU provides the TA of the T-DU / cell to the UE. If the TA of the T-DU / cell is still valid, the UE may skip the RACH procedure at step 421 when executing the cell switch. And at steps 422, 423, 424 and 425, the UE, S-DU, T-DU and CU proceed with completion of the LTM procedure.

[0062] A number of enhancements are under discussion, including enhancements to LTM with event- triggered LI measurement reporting, and MIMO enhancements with UE- initiated / event- driven beam management. As described herein, the terms event-triggered, event-driven, event- based and the like may be used interchangeably. For example, agreement has been made on a number of LTM events based on beam specific quality of the serving cell and candidate cells as LI measurement events. These LTM events include LTM-2 (beam of serving cell becomes worse than absolute threshold), LTM-3 (beam of candidate cell becomes amount of offset better than beam of serving cell), LTM-4 (beam of candidate cell becomesbeter than absolute threshold), and LTM-5 (beam of serving cell becomes worse than a first absolute threshold and beam of candidate cell becomes better than another, second absolute threshold).

[0063] The above agreed LTM events are based on the beam specific quality of a serving cell and candidate cell to trigger a measurement event. Similarly in UE-initiated / event-driven beam management, agreements have been made to support events like Event-2 which implies quality of at least one new beam becomes a threshold value better than the current beam. The beam specific quality may be indicated in a number of different manners, such as RS received power (RSRP), RS received quality (RSRQ), signal to interference plus noise ratio (SINR), or the like. When the event is fulfilled, the UE 110 may be configured indicate the event to the radio access node 202, and typically report measurements to the radio access node on one or more RSs that fulfilled the event.In LTM-3, which may be referred as relative threshold event, a beam of a serving cell is referred as the reference resource / beam. In LTM-4, which may be referred as absolute threshold event, the beam of a candidate cell may be any of the candidate cell RSs that are configured for measurement.

[0064] In LTM-3, which may be referred as relative threshold event, a beam of a serving cell can be referred as the reference resource. Similarly, in Event- 2, the current beam can be referred as the reference resource. The reference resource may be a RS resource of a beam (the reference resource at times referred to as a reference beam, or as a reference resource / beam). In LTM-4, which may be referred as absolute threshold event, the beam of a candidate cell may be any of the candidate cell RSs that are configured for measurement.

[0065] In above cases, when the cell configuration is for serving cell and / or candidate cell is a single TRP (or non-multi TRP) configuration, derivation of the beam of the serving cell (and its reference resource) may be rather straightforward. That is, the beam of the serving cell may be the indicated TCI state (the RS included in the indicated TCI state). When the UE is configured for multi-TRP operation (single-DCI / multi-DCI), however, the UE has at least two indicated TCI states, which may create an ambiguity in the reference resource or the serving cell beam quality for a configured event (e.g. LTM- 2 / 3 / 5). This may be applicable for both LTM and UE-initiated / event-driven beam management events.

[0066] Example implementations of the present disclosure therefore provide a solution to the issue of reference resource determination for event-based LI measurement reporting. The solution of example implementations may apply to a UE 110 configured with at least two indicated TCI states, and provide different options for the UE to use at least one of the indicated TCI states to determine a quality of a reference resource, which can be taken for evaluation as the quality of the serving cell for LTM or as the quality of the current beam for UE-initiated / event-driven beam management. The solution of example implementations may apply to any event-triggered LI measurement reporting in which the quality of a reference resource (e.g., RS or beam) needs to be taken into account such as one of more events for event-based LI measurement reporting for LTM, UE-initiated / event-driven beam management, or the like.

[0067] Some example implementations provide a UE 110 may operate with a configuration including at least two indicated TCI states to be applied to at least one downlink channel in a serving cell (source gNB 206, S-DU 210A). The UE may receive a reporting configuration for event-triggered LI measurement reporting (e.g., at step 302, 410). For LTM, event-triggered LI measurement reporting configuration may be provided by the gNB to the UE as a part of the LTM configuration in a RRC Reconfiguration message for cell switch configuration. For UE-initiated / event-driven beam management, event-triggered LI measurement reporting may be provided by the gNB to the UE as a serving cell configuration in a RRC configuration or reconfiguration message. The UE may determine a reference resource quality based on at least one RS resource of respective RS resources associated with the at least two indicated TCI states. The UE may determine that a reporting event of the reporting configuration is fulfilled based on at least the reference resource quality, and send a measurement report triggered by the determination to the serving cell (e.g., at step 305, 418).

[0068] Some example implementations provide a gNB 206 to configure a UE 110 with at least two indicated TCI states, and send a reporting configuration to the UE for event-triggered LI measurement reporting. The gNB (S-DU 212A) may receive a measurement report triggered by a determination at the UE that a reporting event is fulfilled based on at least the reference resource quality determined by the UE based on at least one respective RS resource associated with the at least one of the at least two indicated TCI states. And, for LTM, the gNB may make a determination whether to initiate an early synchronization or cell switchprocedure toward a candidate cell based on the measurement report (e.g., step 414, 419). In case of UE-initiated / event-driven beam management, the gNB may decide whether to change one or more indicated beams for beam management.

[0069] In some examples, each TCI state of the at least two indicated TCI states is a DL or joint TCI state. In some examples, each of the respective RS resources may be associated with a TCI state is configured in quasi co-location (QCL) information of the TCI state, or a QCL source of at least one RS resource configured in QCL information of the TCI state. In this regard, each of the respective RS resources may be a SSB, a CSI-RS, or a tracking RS (TRS).

[0070] The UE 110 may determine a reference resource quality according to any of a number of different options. In a first option, which of the at least two TCI states is used for the reference resource may be configured by the network (e.g., gNB 206). In this regard, in some examples, the RS resource(s) on which the reference resource quality is determined may be associated with indicated TCI state(s), and the reporting configuration may further comprise an indication of the indicated TCI state(s).

[0071] In some more particular examples, the reporting configuration (that may include a resource configuration and / or report configuration) may have a parameter or field that indicates which of the at least two indicated TCI states (e.g., first indicated TCI state or second indicated TCI state) to use. If the first indicated TCI state is used, the UE 110 may derive the reference resource quality (serving cell (beam) measurement for LTM or current beam measurement for UE-initiated / event-driven beam management) for event evaluation based on the first indicated TCI state. If the second indicated TCI state is used, the UE may derive the reference resource quality for event evaluation based on the second indicated TCI state. And if both the first indicated TCI state and the second indicated TCI state are used, the UE may derive the reference resource quality for event evaluation based on both indicated TCI states, such as in the manner provided below for a second option.

[0072] In the second option, the reference resource quality may be determined based on multiple of the respective RS resources associated with multiple of the at least two indicated TCI states. In some of these examples, the reference resource quality may be determined as a highest RS resource quality of the multiple of the respective RS resources. In other of these examples, the reference resource quality may be determined as an average RS resource quality of the multiple of the respective RS resources. Similar to the first option, in examples in whichanother option indicates use of multiple of the respective RS resources associated with multiple of the at least two indicated TCI states, the UE may apply the second option.

[0073] In a third option, the reference resource quality may be determined based on the RS resource associated with the indicated TCI state provisioning the DCI (single-DCI multi-TRP). In this regard, in some examples, the reference resource quality may be determined based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of at least one downlink control channel carrying a downlink control information. According to the third option, if the UE 110 is configured with single-DCI multi-TRP and has at least two indicated TCI states, the UE may use the RS resource included in the indicated TCI state that is used for reception of PDCCH (DCI). In some examples, if the UE is configured with single-DCI multi-TRP and configured to use multiple indicated TCI states for reception of PDCCH (DCI), the the UE may apply the second option.

[0074] In a fourth option, the reference resource quality may be determined based on the RS resource associated with the indicated TCI state of the TRP with a CORESET provisioning the CSS. In this regard, in some examples, the reference resource quality may be determined based on at least one of the respective RS resources associated with at least one of the at least two indicated TCI states that is applied for reception of at least one CORESET configured to follow a unified TCI state and associated with a CSS.

[0075] In some examples of the fourth option, a CORESET or CORESETs may be configured to follow an indicated TCI state and associated with a CSS. In one example, the CORESET may be configured with CSS, and the UE 110 may use the RS resource associated with the indicated TCI state for that CORESET as the reference resource. If multiple CORESETs are configured with CSSs, and associated with different indicated TCI states, the UE may use multiple (e.g., both) indicated TCI states (e.g., the second option), or use either or multiple of the TCI states based on the reporting configuration (e.g., the first option).

[0076] In a fifth option, the reference resource quality may be determined based on the RS resource associated with the indicated TCI state of the TRP associated with the CORESET with index 0 (CORESETO). In some examples, then, the reference resource quality may be determined based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of CORESETO configured to follow a unified TCI state. According to the fifth option, if a CORESET is a CORESETO (configured withsearch space zero) and configured to follow a unified TCI state (first or second), the UE 110 may use the indicated TCI state that the CORESET is configured to follow. If a CORESET with index 0 is configured to follow both indicated TCI states, the the UE may apply the second option.

[0077] In a sixth option, the reference resource quality may be determined based on the RS resource associated with the indicated TCI state associated with a CORSET associated with a CORESET pool index 0 (or 1). In this regard, in some examples, the reference resource quality may be determined based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of at least one CORESET associated with a CORESET pool index 0 (or pool index 1).

[0078] In a seventh option, the reference resource quality may be determined based on the RS resource associated with the indicated TCI state associated with a specific TAG ID (e.g., tag-ID or tag2-ID). In this regard, in some examples, the reference resource quality may be determined based on one of the respective RS resources associated with one of the at least two indicated TCI states associated with a particular TAG ID from multiple configured TAG IDs. According ot the seventh option, if the serving cell is configured with two TAGs to handle multi-TRP UL transmissions to two TRPs with different TAs), the UE 110 may use the indicated TCI state of TRP with tag-ID (or tag2-ID).

[0079] In an eighth option, the reference resource quality may be determined based on the RS resource associated with the indicated TCI state of the TRP with a higher number of activated TCI states (compared to another TRP). In some examples, then, the reference resource quality may be determined based on one of the respective RS resources associated with the the indicated TCI state of one of at least two TRPs having a higher number of activated TCI states than other of the at least two TRPs.

[0080] According to various example implementations, the indicated TCI state may refer to the DL or joint TCI state. The use of TCI state (TCI state ID) for measurement for evaluation of a reporting event may refer to using the RS resource(s) included or associated with the TCI state ID. Examples of suitable RS resources include the QCL information RS of TCI state (SSB / CSI-RS), the QCL source RS (SSB / CSI-RS) of the QCL information RS of TCI state, the SSB that is associated with the TCI State a QCL source, and TRS or the QCL source RS of the TRS (SSB / CSI-RS).

[0081] FIG. 5 is a flowchart illustrating various steps in a method 500 according to various example implementations. The method includes operating with a configuration including at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell, as shown at block 502. The method includes receiving a reporting configuration for event-triggered layer 1 measurement reporting, as shown at block 504. The method includes determining a reference resource quality based on at least one reference signal (RS) resource of respective RS resources associated with the at least two indicated TCI states, as shown at block 506. The method includes determining that a reporting event of the reporting configuration is fulfilled based on at least the reference resource quality, as shown at block 508. And the method includes sending a measurement report triggered by the determination to the serving cell, as shown at block 510.

[0082] In some examples, the at least one RS resource is associated with at least one indicated TCI state of the at least two indicated TCI states, and the reporting configuration further includes an indication of the at least one indicated TCI state.

[0083] In some examples, the reference resource quality is determined at block 506 based on multiple of the respective RS resources associated with multiple of the at least two indicated TCI states.

[0084] In some examples, the reference resource quality is determined at block 506 as a highest or an average RS resource quality of the multiple of the respective RS resources associated with the multiple of the at least two indicated TCI states.

[0085] In some examples, the reference resource quality is determined at block 506 based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of at least one downlink control channel carrying a downlink control information.

[0086] In some examples, the reference resource quality is determined at block 506 based on at least one of the respective RS resources associated with at least one of the at least two indicated TCI states that is applied for reception of at least one control resource set (CORESET) configured to follow a unified TCI state and associated with a common search space.

[0087] In some examples, the reference resource quality is determined at block 506 based on one of the respective RS resources associated with one of the at least two indicated TCIstates that is applied for reception of a control resource set (CORESET) with index 0 configured to follow a unified TCI state.

[0088] In some examples, the reference resource quality is determined at block 506 based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of at least one control resource set (CORESET) associated with a CORESET pool index 0.

[0089] In some examples, the reference resource quality is determined at block 506 based on one of the respective RS resources associated with one of the at least two indicated TCI states associated with a particular timing advance group (TAG) identifier (ID) from multiple configured TAG IDs.

[0090] In some examples, the at least two indicated TCI states and thereby the respective RS resources are associated with at least two transmission-reception points (TRPs). In some of these examples, the reference resource quality is determined at block 506 based on one of the respective RS resources associated with one of the at least two indicated TCI states associated with one of the at least two TRPs having a higher number of activated TCI states than other of the at least two TRPs.

[0091] In some examples, each TCI state of the at least two indicated TCI states is a downlink or joint TCI state.

[0092] In some examples, each of the respective RS resources associated with a TCI state of the at least two indicated TCI states is configured in quasi co-location (QCL) information of the TCI state, or a QCI source of at least one RS resource configured in QCL information of the TCI state.

[0093] In some examples, each of the respective RS resources is a synchronization signal block (SSB), a channel state information RS (CSI-RS), or a tracking RS (TRS).

[0094] FIG. 6 is a flowchart illustrating various steps in a method 600 according to various example implementations. The method includes configuring a user equipment (UE) with at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell, as shown at block 602. The method includes sending a reporting configuration to the UE for event-triggered layer 1 measurement reporting, the reporting configuration including an indication of at least one of the at least two indicated TCI states, as shown at block 604. The method includes receiving a measurement report triggeredby a determination at the UE that a reporting event of the reporting configuration is fulfilled based on at least a reference resource quality determined based on at least one respective reference signal (RS) resource associated with the at least one of the at least two indicated TCI states, as shown at block 606. And the method includes making a determination whether to initiate an early synchronization or cell switch procedure toward a candidate cell, or whether to change one or more indicated beams for beam management, based on the measurement report, as shown at block 608.

[0095] In some examples, the measurement configuration includes an indication of one of the at least two indicated TCI states, and the reference resource quality is determined based on a respective RS resource associated with the one of the at least two indicated TCI states.

[0096] In some examples, the measurement configuration includes an indication of multiple of the at least two indicated TCI states, and the reference resource quality is determined based on respective RS resources associated with the multiple of the at least two indicated TCI states.

[0097] In some examples, the measurement configuration includes an indication of multiple of the at least two indicated TCI states, and the reference resource quality is determined as a highest or an average RS resource quality of respective RS resources associated with the multiple of the at least two indicated TCI states.

[0098] According to example implementations of the present disclosure, a telecommunications system 100 or PLMN 102, and its components such as a UE 110, gNB 206, CU 208, DU 210, S-DU 210A and / or T-DU 210B, may be implemented by various means. Means for implementing the system and its components may include hardware, firmware, software, or combinations thereof. In some examples, one or more apparatuses may be configured to function as or otherwise implement the system and its components shown and described herein. In examples involving more than one apparatus, the respective apparatuses may be connected to or otherwise in communication with one another in a number of different manners, such as directly or indirectly via a wired or wireless network or the like.

[0099] According to some example implementations, at least some of the method 500 described with respect to FIG. 5 may be carried out by an apparatus comprising means for performing functions corresponding steps of the method. Similarly, at least some of the method 600 described with respect to FIG. 6 may be carried out by an apparatus comprisingmeans for performing functions corresponding steps of the method. Examples of a suitable apparatus may a user equipment, user device, user terminal or the like. Other examples of a suitable apparatus may include a gNB (e.g., gNB-DU, gNB-CU), ng-eNB or any suitable apparatus, such as a server, host or node.

[0100] FIG. 7 illustrates an apparatus 700 in which means for performing various functions includes hardware, alone or under direction of one or more computer programs from a computer-readable storage medium or other memory, such as computer memory, according to some example implementations of the present disclosure. Generally, an apparatus of example implementations of the present disclosure may comprise, include or be embodied in one or more fixed or portable electronic devices. Examples of suitable electronic devices include a wearable computer, mobile phone, portable computer, desktop computer, workstation computer, server (server computer) or the like. The apparatus may include one or more of each of a number of components such as, for example, processing circuitry 702 connected to computer-readable storage medium or other memory 704.

[0101] The processing circuitry 702 may be composed of one or more processors alone or in combination with one or more computer-readable storage media. The processing circuitry is generally any piece of computer hardware that is capable of processing information such as, for example, data, computer programs and / or other suitable electronic information. The processing circuitry is composed of a collection of electronic circuits some of which may be packaged as an integrated circuit or multiple interconnected integrated circuits (an integrated circuit at times more commonly referred to as a “chip”). The processing circuitry may be configured to execute computer programs, which may be stored onboard the processing circuitry or otherwise stored in the memory 704 (of the same or another apparatus).

[0102] The processing circuitry 702 may be a number of processors, a multi-core processor or some other type of processor, depending on the particular implementation. Further, the processing circuitry may be implemented using a number of heterogeneous processor systems in which a main processor is present with one or more secondary processors on a single chip. As another illustrative example, the processing circuitry may be a symmetric multi-processor system containing multiple processors of the same type. In yet another example, the processing circuitry may be embodied as or otherwise include one or more ASICs, FPGAs or the like. Thus, although the processing circuitry may be capable ofexecuting a computer program to perform one or more functions, the processing circuitry of various examples may be capable of performing one or more functions without the aid of a computer program. In either instance, the processing circuitry may be appropriately programmed to perform functions or operations according to example implementations of the present disclosure.

[0103] The memory 704 is generally any piece of computer hardware that is capable of storing information such as, for example, data, computer programs, instructions 706 (e.g., computer-readable program code) and / or other suitable information either on a temporary basis and / or a permanent basis. The memory may include volatile and / or non-volatile memory, and may be fixed or removable. Examples of suitable memory include recording media, random access memory (RAM), read-only memory (ROM), a hard drive, a flash memory, a thumb drive, a removable computer diskette, an optical disk or some combination thereof.

[0104] The memory 704 is a non-transitory device capable of storing information. One example of a suitable memory is a computer-readable storage medium, which is distinguishable from a computer-readable transmission medium capable of carrying information from one location to another. Examples of suitable computer-readable transmission media comprise electronic carrier signals, telecommunications signals, or some combination thereof. As used herein, the term “non-transitory” is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM versus ROM). A computer-readable medium as described herein generally refers to a computer-readable storage medium or computer-readable transmission medium. A computer- readable medium is any entity or device capable in which information, such as one or more computer programs or portions thereof, may be stored and carried.

[0105] In addition to the memory 704 (e.g., computer-readable storage medium), the processing circuitry 702 may also be connected to one or more interfaces for displaying, transmitting and / or receiving information. The interfaces may include a communications interface 708 and / or one or more user interfaces. The communications interface may be configured to transmit and / or receive information, such as to and / or from other apparatus(es), network(s) or the like. The communications interface may be configured to transmit and / or receive information by physical (wired) and / or wireless communications links. Examples ofsuitable communication interfaces include a network interface controller (NIC), wireless NIC (WNIC) or the like.

[0106] The user interfaces may include a display 710 and / or one or more user input interfaces 712. The display may be configured to present or otherwise display information to a user, suitable examples of which include a liquid crystal display (LCD), light-emitting diode (LED) display, organic LED (OLED) display, active-matrix OLED (AMOLED) or the like. The user input interfaces may be wired or wireless, and may be configured to receive information from a user into the apparatus, such as for processing, storage and / or display. Suitable examples of user input interfaces include a microphone, image or video capture device, keyboard or keypad, joystick, touch-sensitive surface (separate from or integrated into a touchscreen), biometric sensor or the like. The user interfaces may further include one or more interfaces for communicating with peripherals such as printers, scanners or the like.

[0107] Execution of the instructions 706 by the processing circuitry 702, or storage of the instructions in the memory 704, supports combinations of operations for implementing example implementations of the present disclosure. In this manner, an apparatus 700 may comprise at least one processing circuitry and at least one memory coupled to the at least one processing circuitry, where the at least one processing circuitry is configured to execute instructions stored in the at least one memory. It will also be understood that one or more functions, and combinations of functions, may be implemented by special purpose hardwarebased computer systems and / or processing circuitry which perform the specified functions, or combinations of special purpose hardware and program code instructions.

[0108] Some example implementations of the present disclosure may also be carried out in the form of a computer process defined by one or more computer programs or portions thereof. Example implementations of the present disclosure may be carried out by executing at least one portion of a computer program comprising instructions. The computer program may be in source code form, object code form, or in some intermediate form. The computer program may be stored in a computer-readable medium that is readable by a computer, processing circuitry or other suitable apparatus. As indicated above, for example, the computer program may be stored in a memory, such as a computer-readable storage medium.Additionally or alternatively, for example, the computer program may be stored in a computer-readable transmission medium. The coding of software for carrying out exampleimplementations of the present disclosure is well within the scope of a person of ordinary skill in the art.

[0109] As will be appreciated, any suitable instructions may be loaded onto a computer, a processing circuitry or other programmable apparatus from a memory or a computer-readable medium (e.g., computer-readable storage medium, computer-readable transmission medium) to produce a particular machine, such that the particular machine becomes a means for implementing the functions specified herein. The instructions may also be stored in a computer-readable medium that can direct a computer, a processing circuitry or other programmable apparatus to function in a particular manner to thereby generate a particular machine or particular article of manufacture. In some examples, the instructions stored in the computer-readable medium may produce an article of manufacture, where the article of manufacture becomes a means for implementing functions described herein. The instructions may be retrieved from a computer-readable medium and loaded into a computer, processing circuitry or other programmable apparatus to configure the computer, processing circuitry or other programmable apparatus to execute operations to be performed on or by the computer, processing circuitry or other programmable apparatus.

[0110] Retrieval, loading and execution of instructions comprising program code instructions may be performed sequentially such that one instruction is retrieved, loaded and executed at a time. In some example implementations, retrieval, loading and / or execution may be performed in parallel such that multiple instructions are retrieved, loaded, and / or executed together. Execution of the program code instructions may produce a computer-implemented process such that the instructions executed by the computer, processing circuitry or other programmable apparatus provide operations for implementing functions described herein.

[0111] As explained above and reiterated below, the present disclosure includes, without limitation, the following example implementations.

[0112] Clause 1. An apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: operate with a configuration including at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; receive a reporting configuration for event-triggered layer 1 measurement reporting; determine a referenceresource quality based on at least one reference signal (RS) resource of respective RS resources associated with the at least two indicated TCI states; determine that a reporting event of the reporting configuration is fulfilled based on at least the reference resource quality; and send a measurement report triggered by the determination to the serving cell.

[0113] Clause 2. The apparatus of clause 1, wherein the at least one RS resource is associated with at least one indicated TCI state of the at least two indicated TCI states, and the reporting configuration further includes an indication of the at least one indicated TCI state.

[0114] Clause 3. The apparatus of clause 1 or clause 2, wherein the reference resource quality is determined based on multiple of the respective RS resources associated with multiple of the at least two indicated TCI states.

[0115] Clause 4. The apparatus of clause 3, wherein the reference resource quality is determined as a highest or an average RS resource quality of the multiple of the respective RS resources associated with the multiple of the at least two indicated TCI states.

[0116] Clause 5. The apparatus of any of clauses 1 to 4, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of at least one downlink control channel carrying a downlink control information.

[0117] Clause 6. The apparatus of any of clauses 1 to 5, wherein the reference resource quality is determined based on at least one of the respective RS resources associated with at least one of the at least two indicated TCI states that is applied for reception of at least one control resource set (CORESET) configured to follow a unified TCI state and associated with a common search space.

[0118] Clause 7. The apparatus of any of clauses 1 to 6, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of a control resource set (CORESET) with index 0 configured to follow a unified TCI state.

[0119] Clause 8. The apparatus of any of clauses 1 to 7, wherein the reference resource qual ity is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of at least one control resource set (CORESET) associated with a CORESET pool index 0.

[0120] Clause 9. The apparatus of any of clauses 1 to 8, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states associated with a particular timing advance group (TAG) identifier (ID) from multiple configured TAG IDs.

[0121] Clause 10. The apparatus of any of clauses 1 to 9, wherein the at least two indicated TCI states and thereby the respective RS resources are associated with at least two transmission-reception points (TRPs), and wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TC states associated with one of the at least two TRPs having a higher number of activated TCI states than other of the at least two TRPs.

[0122] Clause 11. The apparatus of any of clauses 1 to 10, wherein each TCI state of the at least two indicated TCI states is a downlink or joint TCI state.

[0123] Clause 12. The apparatus of any of clauses 1 to 11, wherein each of the respective RS resources associated with a TCI state of the at least two indicated TCI states is configured in quasi co-location (QCL) information of the TCI state, or a QCL source of at least one RS resource configured in QCL information of the TCI state.

[0124] Clause 13. The apparatus of clause 12, wherein each of the respective RS resources is a synchronization signal block (SSB), a channel state information RS (CSI-RS), or a tracking RS (TRS).

[0125] Clause 14. An apparatus comprising: means for operating with a configuration including at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; means for receiving a reporting configuration for event-triggered layer 1 measurement reporting; means for determining a reference resource quality based on at least one reference signal (RS) resource of respective RS resources associated with the at least two indicated TCI states; means for determining that a reporting event of the reporting configuration is fulfilled based on at least the reference resource quality; and means for sending a measurement report triggered by the determination to the serving cell.

[0126] Clause 15. The apparatus of clause 14, wherein the at least one RS resource is associated with at least one indicated TCI state of the at least two indicated TCI states, and the reporting configuration further includes an indication of the at least one indicated TCI state.

[0127] Clause 16. The apparatus of clause 14 or clause 15, wherein the reference resource quality is determined based on multiple of the respective RS resources associated with multiple of the at least two indicated TCI states.

[0128] Clause 17. The apparatus of clause 16, wherein the reference resource quality is determined as a highest or an average RS resource quality of the multiple of the respective RS resources associated with the multiple of the at least two indicated TCI states.

[0129] Clause 18. The apparatus of any of clauses 14 to 17, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of at least one downlink control channel carrying a downlink control information.

[0130] Clause 19. The apparatus of any of clauses 14 to 18, wherein the reference resource quality is determined based on at least one of the respective RS resources associated with at least one of the at least two indicated TCI states that is applied for reception of at least one control resource set (CORESET) configured to follow an unified TCI state and associated with a common search space.

[0131] Clause 20. The apparatus of any of clauses 14 to 19, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of a control resource set (CORESET) with index 0 configured to follow an unified TCI state.

[0132] Clause 21. The apparatus of any of clauses 14 to 20, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of at least one control resource set (CORESET) associated with a CORESET pool index 0.

[0133] Clause 22. The apparatus of any of clauses 14 to 21, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states associated with a particular timing advance group (TAG) identifier (ID) from multiple configured TAG IDs.

[0134] Clause 23. The apparatus of any of clauses 14 to 22, wherein the at least two indicated TCI states and thereby the respective RS resources are associated with at least two transmission-reception points (TRPs), and wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least twoindicated TC states associated with one of the at least two TRPs having a higher number of activated TCI states than other of the at least two TRPs.

[0135] Clause 24. The apparatus of any of clauses 14 to 23, wherein each TCI state of the at least two indicated TCI states is a downlink or joint TCI state.

[0136] Clause 25. The apparatus of any of clauses 14 to 24, wherein each of the respective RS resources associated with a TCI state of the at least two indicated TCI states is configured in quasi co-location (QCL) information of the TCI state, or a QCI source of at least one RS resource configured in QCL information of the TCI state.

[0137] Clause 26. The apparatus of clause 25, wherein each of the respective RS resources is a synchronization signal block (SSB), a channel state information RS (CSI-RS), or a tracking RS (TRS).

[0138] Clause 27. A method comprising: operating with a configuration including at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; receiving a reporting configuration for event-triggered layer 1 measurement reporting; determining a reference resource quality based on at least one reference signal (RS) resource of respective RS resources associated with the at least two indicated TCI states; determining that a reporting event of the reporting configuration is fulfilled based on at least the reference resource quality; and sending a measurement report triggered by the determination to the serving cell.

[0139] Clause 28. The method of clause 27, wherein the at least one RS resource is associated with at least one indicated TCI state of the at least two indicated TCI states, and the reporting configuration further includes an indication of the at least one indicated TCI state.

[0140] Clause 29. The method of clause 27 or clause 28, wherein the reference resource quality is determined based on multiple of the respective RS resources associated with multiple of the at least two indicated TCI states.

[0141] Clause 30. The method of clause 29, wherein the reference resource quality is determined as a highest or an average RS resource quality of the multiple of the respective RS resources associated with the multiple of the at least two indicated TCI states.

[0142] Clause 31. The method of any of clauses 27 to 30, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the atleast two indicated TCI states that is applied for reception of at least one downlink control channel carrying a downlink control information.

[0143] Clause 32. The method of any of clauses 27 to 31, wherein the reference resource quality is determined based on at least one of the respective RS resources associated with at least one of the at least two indicated TCI states that is applied for reception of at least one control resource set (CORESET) configured to follow a unified TCI state and associated with a common search space.

[0144] Clause 33. The method of any of clauses 27 to 32, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of a control resource set (CORESET) with index 0 configured to follow a unified TCI state.

[0145] Clause 34. The method of any of clauses 27 to 33, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of at least one control resource set (CORESET) associated with a CORESET pool index 0.

[0146] Clause 35. The method of any of clauses 27 to 34, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states associated with a particular timing advance group (TAG) identifier (ID) from multiple configured TAG IDs.

[0147] Clause 36. The method of any of clauses 27 to 35, wherein the at least two indicated TCI states and thereby the respective RS resources are associated with at least two transmission-reception points (TRPs), and wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TC states associated with one of the at least two TRPs having a higher number of activated TCI states than other of the at least two TRPs.

[0148] Clause 37. The method of any of clauses 27 to 36, wherein each TCI state of the at least two indicated TCI states is a downlink or joint TCI state.

[0149] Clause 38. The method of any of clauses 27 to 37, wherein each of the respective RS resources associated with a TCI state of the at least two indicated TCI states is configured in quasi co-location (QCL) information of the TCI state, or a QCI source of at least one RS resource configured in QCL information of the TCI state.

[0150] Clause 39. The method of clause 38, wherein each of the respective RS resources is a synchronization signal block (SSB), a channel state information RS (CSI-RS), or a tracking RS (TRS).

[0151] Clause 40. A computer-readable storage medium that is non-transitory and has instructions stored therein that, in response to execution by at least one processing circuitry, causes an apparatus to at least: operate with a configuration including at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; receive a reporting configuration for event-triggered layer 1 measurement reporting; determine a reference resource quality based on at least one reference signal (RS) resource of respective RS resources associated with the at least two indicated TCI states; determine that a reporting event of the reporting configuration is fulfilled based on at least the reference resource quality; and send a measurement report triggered by the determination to the serving cell.

[0152] Clause 41. The computer-readable storage medium of clause 40, wherein the at least one RS resource is associated with at least one indicated TCI state of the at least two indicated TCI states, and the reporting configuration further includes an indication of the at least one indicated TCI state.

[0153] Clause 42. The computer-readable storage medium of clause 40 or clause 41, wherein the reference resource quality is determined based on multiple of the respective RS resources associated with multiple of the at least two indicated TCI states.

[0154] Clause 43. The computer-readable storage medium of clause 42, wherein the reference resource quality is determined as a highest or an average RS resource quality of the multiple of the respective RS resources associated with the multiple of the at least two indicated TCI states.

[0155] Clause 44. The computer-readable storage medium of any of clauses 40 to 43, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of at least one downlink control channel carrying a downlink control information.

[0156] Clause 45. The computer-readable storage medium of any of clauses 40 to 44, wherein the reference resource quality is determined based on at least one of the respective RS resources associated with at least one of the at least two indicated TCI states that is applied forreception of at least one control resource set (CORESET) configured to follow a unified TCI state and associated with a common search space.

[0157] Clause 46. The computer-readable storage medium of any of clauses 40 to 45, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of a control resource set (CORESET) with index 0 configured to follow a unified TCI state.

[0158] Clause 47. The computer-readable storage medium of any of clauses 40 to 46, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of at least one control resource set (CORESET) associated with a CORESET pool index 0.

[0159] Clause 48. The computer-readable storage medium of any of clauses 40 to 47, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states associated with a particular timing advance group (TAG) identifier (ID) from multiple configured TAG IDs.

[0160] Clause 49. The computer-readable storage medium of any of clauses 40 to 48, wherein the at least two indicated TCI states and thereby the respective RS resources are associated with at least two transmission-reception points (TRPs), and wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TC states associated with one of the at least two TRPs having a higher number of activated TCI states than other of the at least two TRPs.

[0161] Clause 50. The computer-readable storage medium of any of clauses 40 to 49, wherein each TCI state of the at least two indicated TCI states is a downlink or joint TCI state.

[0162] Clause 51. The computer-readable storage medium of any of clauses 40 to 50, wherein each of the respective RS resources associated with a TCI state of the at least two indicated TCI states is configured in quasi co-location (QCL) information of the TCI state, or a QCL source of at least one RS resource configured in QCL information of the TCI state.

[0163] Clause 52. The computer-readable storage medium of clause 51, wherein each of the respective RS resources is a synchronization signal block (SSB), a channel state information RS (CSI-RS), or a tracking RS (TRS).

[0164] Clause 53. An apparatus comprising means for performing the method of any of clauses 27 to 39.

[0165] Clause 54. A computer-readable medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 27 to 39.

[0166] Clause 55. A computer-readable storage medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 27 to 39.

[0167] Clause 56. A computer program comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 27 to 39.

[0168] Clause 57. An apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: configure a user equipment (UE) with at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; send a reporting configuration to the UE for event-triggered layer 1 measurement reporting, the reporting configuration including an indication of at least one of the at least two indicated TCI states; receive a measurement report triggered by a determination at the UE that a reporting event of the reporting configuration is fulfilled based on at least a reference resource quality determined based on at least one respective reference signal (RS) resource associated with the at least one of the at least two indicated TCI states; and make a determination whether to initiate an early synchronization or cell switch procedure toward a candidate cell, or whether to change one or more indicated beams for beam management, based on the measurement report.

[0169] Clause 58. The apparatus of clause 57, wherein the measurement configuration includes an indication of one of the at least two indicated TCI states, and the reference resource quality is determined based on a respective RS resource associated with the one of the at least two indicated TCI states.

[0170] Clause 59. The apparatus of clause 57 or clause 58, wherein the measurement configuration includes an indication of multiple of the at least two indicated TCI states, andthe reference resource quality is determined based on respective RS resources associated with the multiple of the at least two indicated TCI states.

[0171] Clause 60. The apparatus of any of clauses 57 to 59, wherein the measurement configuration includes an indication of multiple of the at least two indicated TCI states, and the reference resource quality is determined as a highest or an average RS resource quality of respective RS resources associated with the multiple of the at least two indicated TCI states.

[0172] Clause 61. An apparatus comprising: means for configuring an user equipment (UE) with at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; means for sending a reporting configuration to the UE for event-triggered layer 1 measurement reporting, the reporting configuration including an indication of at least one of the at least two indicated TCI states; means for receiving a measurement report triggered by a determination at the UE that a reporting event of the reporting configuration is fulfilled based on at least a reference resource quality determined based on at least one respective reference signal (RS) resource associated with the at least one of the at least two indicated TCI states; and means for making a determination whether to initiate an early synchronization or cell switch procedure toward a candidate cell, or whether to change one or more indicated beams for beam management, based on the measurement report.

[0173] Clause 62. The apparatus of clause 61, wherein the measurement configuration includes an indication of one of the at least two indicated TCI states, and the reference resource quality is determined based on a respective RS resource associated with the one of the at least two indicated TCI states.

[0174] Clause 63. The apparatus of clause 61 or clause 62, wherein the measurement configuration includes an indication of multiple of the at least two indicated TCI states, and the reference resource quality is determined based on respective RS resources associated with the multiple of the at least two indicated TCI states.

[0175] Clause 64. The apparatus of any of clauses 61 to 63, wherein the measurement configuration includes an indication of multiple of the at least two indicated TCI states, and the reference resource quality is determined as a highest or an average RS resource quality of respective RS resources associated with the multiple of the at least two indicated TCI states.

[0176] Clause 65. A method comprising: configuring a user equipment (UE) with at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; sending a reporting configuration to the UE for event- triggered layer 1 measurement reporting, the reporting configuration including an indication of at least one of the at least two indicated TCI states; receiving a measurement report triggered by a determination at the UE that a reporting event of the reporting configuration is fulfilled based on at least a reference resource quality determined based on at least one respective reference signal (RS) resource associated with the at least one of the at least two indicated TCI states; and making a determination whether to initiate an early synchronization or cell switch procedure toward a candidate cell, or whether to change one or more indicated beams for beam management, based on the measurement report.

[0177] Clause 66. The method of clause 65, wherein the measurement configuration includes an indication of one of the at least two indicated TCI states, and the reference resource quality is determined based on a respective RS resource associated with the one of the at least two indicated TCI states.

[0178] Clause 67. The method of clause 65 or clause 66, wherein the measurement configuration includes an indication of multiple of the at least two indicated TCI states, and the reference resource quality is determined based on respective RS resources associated with the multiple of the at least two indicated TCI states.

[0179] Clause 68. The method of any of clauses 65 to 67, wherein the measurement configuration includes an indication of multiple of the at least two indicated TCI states, and the reference resource quality is determined as a highest or an average RS resource quality of respective RS resources associated with the multiple of the at least two indicated TCI states.

[0180] Clause 69. A computer-readable storage medium that is non-transitory and has instructions stored therein that, in response to execution by at least one processing circuitry, causes an apparatus to at least: configure a user equipment (UE) with at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; send a reporting configuration to the UE for event-triggered layer 1 measurement reporting, the reporting configuration including an indication of at least one of the at least two indicated TCI states; receive a measurement report triggered by a determination at the UE that a reporting event of the reporting configuration is fulfilled basedon at least a reference resource quality determined based on at least one respective reference signal (RS) resource associated with the at least one of the at least two indicated TCI states; and make a determination whether to initiate an early synchronization or cell switch procedure toward a candidate cell, or whether to change one or more indicated beams for beam management, based on the measurement report.

[0181] Clause 70. The computer-readable storage medium of clause 69, wherein the measurement configuration includes an indication of one of the at least two indicated TCI states, and the reference resource quality is determined based on a respective RS resource associated with the one of the at least two indicated TCI states.

[0182] Clause 71. The computer-readable storage medium of clause 69 or clause 70, wherein the measurement configuration includes an indication of multiple of the at least two indicated TCI states, and the reference resource quality is determined based on respective RS resources associated with the multiple of the at least two indicated TCI states.

[0183] Clause 72. The computer-readable storage medium of any of clauses 69 to 71, wherein the measurement configuration includes an indication of multiple of the at least two indicated TCI states, and the reference resource quality is determined as a highest or an average RS resource quality of respective RS resources associated with the multiple of the at least two indicated TCI states.

[0184] Clause 73. An apparatus comprising means for performing the method of any of clauses 65 to 68.

[0185] Clause 74. A computer-readable medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 65 to 68.

[0186] Clause 75. A computer-readable storage medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 65 to 68.

[0187] Clause 76. A computer program comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 65 to 68.

[0188] Many modifications and other implementations of the disclosure set forth herein will come to mind to one skilled in the art to which the disclosure pertains having the benefitof the teachings presented in the foregoing description and the associated figures. Therefore, it is to be understood that the disclosure is not to be limited to the specific implementations disclosed and that modifications and other implementations are intended to be included within the scope of the appended claims. Moreover, although the foregoing description and the associated figures describe example implementations in the context of certain example combinations of elements and / or functions, it should be appreciated that different combinations of elements and / or functions may be provided by alternative implementations without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and / or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

CLAIMS:

1. An apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: operate with a configuration including at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; receive a reporting configuration for event-triggered layer 1 measurement reporting; determine a reference resource quality based on at least one reference signal (RS) resource of respective RS resources associated with the at least two indicated TCI states; determine that a reporting event of the reporting configuration is fulfilled based on at least the reference resource quality; and send a measurement report triggered by the determination to the serving cell.

2. The apparatus of claim 1, wherein the at least one RS resource is associated with at least one indicated TCI state of the at least two indicated TCI states, and the reporting configuration further includes an indication of the at least one indicated TCI state.

3. The apparatus of claim 1, wherein the reference resource quality is determined based on multiple of the respective RS resources associated with multiple of the at least two indicated TCI states.

4. The apparatus of claim 3, wherein the reference resource quality is determined as a highest or an average RS resource quality of the multiple of the respective RS resources associated with the multiple of the at least two indicated TCI states.

5. The apparatus of claim 1, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of at least one downlink control channel carrying a downlink control information.

6. The apparatus of claim 1, wherein the reference resource quality is determined based on at least one of the respective RS resources associated with at least one of the at least two indicated TCI states that is applied for reception of at least one control resource set (CORESET) configured to follow a unified TCI state and associated with a common search space.

7. The apparatus of claim 1, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of a control resource set (CORESET) with index 0 configured to follow a unified TCI state.

8. The apparatus of claim 1, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states that is applied for reception of at least one control resource set (CORESET) associated with a CORESET pool index 0.

9. The apparatus of claim 1, wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states associated with a particular timing advance group (TAG) identifier (ID) from multiple configured TAG IDs.

10. The apparatus of claim 1, wherein the at least two indicated TCI states and thereby the respective RS resources are associated with at least two transmission-reception points (TRPs), and wherein the reference resource quality is determined based on one of the respective RS resources associated with one of the at least two indicated TCI states associated with one of the at least two TRPs having a higher number of activated TCI states than other of the at least two TRPs.

11. The apparatus of claim 1, wherein each TCI state of the at least two indicated TCI states is a downlink or joint TCI state.

12. The apparatus of claim 1, wherein each of the respective RS resources associated with a TCI state of the at least two indicated TCI states is configured in quasi colocation (QCL) information of the TCI state, or a QCL source of at least one RS resource configured in QCL information of the TCI state.

13. The apparatus of claim 12, wherein each of the respective RS resources is a synchronization signal block (SSB), a channel state information RS (CSLRS), or a tracking RS (TRS).

14. A method comprising: operating with a configuration including at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; receiving a reporting configuration for event-triggered layer 1 measurement reporting; determining a reference resource quality based on at least one reference signal (RS) resource of respective RS resources associated with the at least two indicated TCI states; determining that a reporting event of the reporting configuration is fulfilled based on at least the reference resource quality; and sending a measurement report triggered by the determination to the serving cell.

15. The method of claim 14, wherein the at least one RS resource is associated with at least one indicated TCI state of the at least two indicated TCI states, and the reporting configuration further includes an indication of the at least one indicated TCI state.

16. An apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least:configure a user equipment (UE) with at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; send a reporting configuration to the UE for event-triggered layer 1 measurement reporting, the reporting configuration including an indication of at least one of the at least two indicated TCI states; receive a measurement report triggered by a determination at the UE that a reporting event of the reporting configuration is fulfilled based on at least a reference resource quality determined based on at least one respective reference signal (RS) resource associated with the at least one of the at least two indicated TCI states; and make a determination whether to initiate an early synchronization or cell switch procedure toward a candidate cell, or whether to change one or more indicated beams for beam management, based on the measurement report.

17. The apparatus of claim 16, wherein the measurement configuration includes an indication of one of the at least two indicated TCI states, and the reference resource quality is determined based on a respective RS resource associated with the one of the at least two indicated TCI states.

18. The apparatus of claim 16, wherein the measurement configuration includes an indication of multiple of the at least two indicated TCI states, and the reference resource quality is determined based on respective RS resources associated with the multiple of the at least two indicated TCI states.

19. The apparatus of claim 16, wherein the measurement configuration includes an indication of multiple of the at least two indicated TCI states, and the reference resource quality is determined as a highest or an average RS resource quality of respective RS resources associated with the multiple of the at least two indicated TCI states.

20. A method comprising: configuring a user equipment (UE) with at least two indicated transmission configuration indicator (TCI) states to be applied to at least one downlink channel in a serving cell; sending a reporting configuration to the UE for event-triggered layer 1 measurement reporting, the reporting configuration including an indication of at least one of the at least two indicated TCI states; receiving a measurement report triggered by a determination at the UE that a reporting event of the reporting configuration is fulfilled based on at least a reference resource quality determined based on at least one respective reference signal (RS) resource associated with the at least one of the at least two indicated TCI states; and making a determination whether to initiate an early synchronization or cell switch procedure toward a candidate cell, or whether to change one or more indicated beams for beam management, based on the measurement report.

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