Lower-layer triggered mobility (LTM) event triggered reporting with different types of refernce signals

Abstract

A method is provided that includes determining a reference signal associated with a serving beam and a reference signal associated with a candidate beam are different types of reference signal. The method includes determining a second reference signal associated with one of the serving beam or the candidate beam that is the same type of reference signal as the reference signal associated with the other of the serving beam or the candidate beam. And the method includes sending a measurement report to the serving beam triggered by a determination that a reporting event of the one or more reporting events is fulfilled based on an evaluation for the second reference signal associated with the one of the serving beam or the candidate beam and the reference signal associated with the other of the serving beam or the candidate beam.

Description

LOWER-LAYER TRIGGERED MOBILITY (LTM) EVENT EVALUATIONTECHNOLOGICAL 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 withother 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 (3GPP).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: means for receiving an event- triggered layer 1 (LI) measurement reporting configuration including one or more reporting events associated with a serving beam and at least one candidate beam, and that indicates one or more reference signals of the one or more candidate beams to monitor for the one or more reporting events; means for determining a reference signal associated with the serving beam and a reference signal associated with a candidate beam are different types of reference signal; means for determining a second reference signal associated with one of the serving beam or the candidate beam that is the same type of reference signal as the reference signal associated with the other of the serving beam or the candidate beam; means for performing an evaluation of the one or more reporting events based on LI measurements of the second reference signal associated with the one of the serving beam or the candidate beam and the reference signal associated with the other of the serving beam or the candidate beam; and means forsending a measurement report to the serving cell triggered by a determination that a reporting event of the one or more reporting events is fulfilled based on the evaluation.

[0008] Some example implementations provide a method comprising: receiving an event- triggered layer 1 (LI) measurement reporting configuration including one or more reporting events associated with a serving beam and at least one candidate beam, and that indicates one or more reference signals of the one or more candidate beams to monitor for the one or more reporting events; determining a reference signal associated with the serving beam and a reference signal associated with a candidate beam are different types of reference signal; determining a second reference signal associated with one of the serving beam or the candidate beam that is the same type of reference signal as the reference signal associated with the other of the serving beam or the candidate beam; performing an evaluation of the one or more reporting events based on LI measurements of the second reference signal associated with the one of the serving beam or the candidate beam and the reference signal associated with the other of the serving beam or the candidate beam; and sending a measurement report to the serving cell triggered by a determination that a reporting event of the one or more reporting events is fulfilled based on the evaluation.

[0009] 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.

[0010] 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 exampleimplementations, 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)

[0011] 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:

[0012] 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;

[0013] FIG. 2 illustrates a 5G deployment of a PLMN, according to some example implementations;

[0014] FIG. 3 is a signaling chart for a L1 / L2 -triggered mobility, also known as lower-layer triggered mobility (LTM) procedure;

[0015] FIG. 4 illustrates beams on which a number of synchronization signal (SS) / physical broadcast channel (PBCH) blocks (SSBs) and channel state information reference signals (CSI-RSs) may be transmitted;

[0016] FIG. 5 is a signaling chart of a procedure for event-based reporting of LI measurements, according to some example implementations;

[0017] FIG. 6 is a flowchart illustrating various steps in a method, according to various example implementations; and

[0018] FIG. 7 illustrates an apparatus according to some example implementations.DETAILED DESCRIPTION

[0019] 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 thescope of the disclosure to those skilled in the art. Like reference numerals refer to like elements throughout.

[0020] 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.

[0021] 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 is true, 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.

[0022] 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.

[0023] 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.

[0024] 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) accompanying software 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.

[0025] 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 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 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.

[0026] 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 stationor 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 3 GPP, 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.

[0027] 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).

[0028] 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).

[0029] 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 variousexamples, 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.

[0030] A RAN 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.

[0031] 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.

[0032] Some deployments of 4G LTE and 5G in particular are considered standalone (SA) deployments. Other deployments combine 4G LTE and 5G 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, andthat 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.

[0033] 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.

[0034] 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 (central node) 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.

[0035] 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 operationsbetween 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.

[0036] 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 5GNR. It is expected that L3 mobility (legacy handover) will also be commonly used in the future.

[0037] L1 / 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.

[0038] 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 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.

[0039] An early synchronization of the UE 110 with the candidate cell(s) follows LTM preparation. As shown at step 304, the UE 110 performs downlink (DL) and may perform uplink (UL) synchronization with the candidate cell(s). For DL synchronization, the gNB 206 may perform an early activation of configured transmission configuration indicator (TCI) states for the candidate cell(s), such as via a MAC control element (MAC CE). The UE may receive this TCI state activation MAC CE, and begin monitoringconfigured DL reference signal (RS) resources associated with the activate TCI states to synchronize with the candidate cell(s).

[0040] During early UL synchronization, the UE 110 may acquire a timing advance (TA) of respective one or more of the candidate cell(s). In this regard, the gNB 206 may request that the UE to perform early TA acquisition for example via contention free random access (CFRA) triggered by a physical downlink control channel (PDCCH) order (using downlink control information (DCI) format 1 0) or other TA acquisition command, following which the UE 110 sends a random access channel (RACH) preamble on the physical random access channel (PRACH) towards an indicated candidate cell. In 3 GPP, the random access (RA) or RACH preamble is sent as a first message (msgl) as part of a RA or RACH procedure; and accordingly, the RA or RACH preamble may at times be referred to as msgl. In order to minimize the data interruption of the gNB due to CFRA towards the candidate cell(s), the UE may not receive a random access response (RAR) from the network (from the candidate cell) for the purpose of TA value acquisition, and the TA value to be used when accessing the candidate cell may be indicated in a subsequent cell switch command.

[0041] 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 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.

[0042] During LTM execution, the UE 110 performs LI measurements on the configured candidate 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 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 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 (or otherwise not acquired), the UE at step 307 initiates a RACH procedure with the target cell to acquire the TA of the target cell. In some cases, the cell switch command may include CFRA RACH related parameters for the UE to perform theRACH procedure. The UE then at step 308 indicates successful completion of the cell switch.

[0043] In 3 GPP, the configuration of a candidate cell (LTM-Candidate) includes a number of information elements (IES), such as a configuration (Itm-EarlyUL-SyncConfig) used to perform the early UL synchronization procedure. The configuration to perform the early UL synchronization procedure includes an IE (EarlyUL-SyncConfig) used to configure random access resources for the early UL synchronization procedure (referred to at times as a RACH configuration). The EarlyUL-SyncConfig IE in turn includes RACH parameters for performing a random access procedure on a candidate cell (rach- ConfigGeneric), and a number of synchronization signal (SS) / physical broadcast channel (PBCH) blocks (SSBs) (ssb-PerRACH-Occasion) per RACH occasion. An SSB may also at times be more simply referred to as a synchronization signal block (SSB).

[0044] Similar to the configuration of a candidate cell for early UL synchronization, the cell switch command (MAC-GE) may include CFRA RACH related parameters for the UE 110 to perform a RACH procedure with the T-DU 210B / cell. These parameters may include, for example, a random access preamble (RACH) index of CFRA resources, a SSB index that indicates the SSB used to determine the RACH occasion for the RACH preamble, and PRACH mask index that indicates RACH occasion(s) associated with the SSB indicated by the SSB index for the RACH preamble.

[0045] LTM was introduced in 3 GPP Release 18 and offers improvements in handover latency and interruption time compared to L3 mobility. But LTM as introduced also has a number of limitations relative to L3 mobility. A number of enhancements of LTM are currently under discussion to address these limitations. One of the objectives is to enable channel state information reference signal (CSI-RS) measurements for LTM procedures. In particular, enhancements are under discussion to support CSI-RS measurements for LTM procedures and enable CSI-RS beam based management.

[0046] For a CSI-RS resource, there may be an SSB index that serves as a source reference signal (RS) for quasi co-location (QCL) information that may be configured by the NG-RAN 204. For periodic CSI-RSs, the QCL information may be given by an IE (qcl-InfoPeriodicCSI-RS) that points to a transmission configuration index (TCI) state, which further points to its QCL source RS. For other types of CSI-RSs, i.e., semi-persistent CSI-RS, TCI state information can be provided by other means, i.e., dynamic signaling like MAC CE. For an aperiodic CSI-RS, the TCI state information may be provided in the RRC configuration but can be also be updated dynamically based on the indicated TCI state(s) if the aperiodic CSI-RS is configured to follow the unified TCI states. This connection between CSI-RS and SSB may be made by a direct QCL reference or an indirect QCL chain reference. In case of direct QCL reference, a SSB may be configured as the QCL source of the CSI-RS. In case of indirect QCL reference, for example, a CSI-RS may have another CSI-RS as the QCL reference, where the reference CSI-RS has a SSB as its QCL reference.

[0047] FIG. 4 illustrates beams 400 on which a number of SSBs and CSI-RSs may be transmitted. Given that an SSB is typically transmitted using a wider beam compared with a CSI-RS, multiple CSI-RS indices may be associated with the same source SSB index. As shown in FIG. 5, for example, SSB1 serves as a source RS for QCL information of four CSI-RS indices, namely, CSI-RS 1, CSI-RS2, CSI-RS3 and CSI-RS4. Likewise, SSB2 serves as a source RS for another four CSI-RS indices, namely, CSI- RSS, CSI-RS6, CSI-RS7 and CSI-RS8.

[0048] As currently specified, a TCI State includes QCL information for receiving on the PDCCH / physical downlink shared channel (PDSCH) from a candidate (target) cell (DL reception), and / or for transmitting on the physical uplink control channel (PUCCH) / physical uplink shared channel (PUSCH) to a candidate (target) cell (UL transmission). The QCL information, in turn, includes the RS, QCL type, and the bandwidth part (bwp) where the RS is located. The QCL type may indicate a typeA (Doppler shift, Doppler spread, average delay, delay spread), typeB (Doppler shift, Doppler spread), typeC (Doppler shift, average delay), or typeD (spatial RX parameter).

[0049] Other enhancements currently under discussion include event- triggered LI measurement reporting for LTM. 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 reporting events based on beam specific quality of the serving cell and candidate cells as LI measurement events. These LTM reporting 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 servingcell), LTM-4 (beam of candidate cell becomes better 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).

[0050] The above agreed LTM reporting events are based on the beam specific quality of a serving cell and candidate cell to trigger a measurement event. The beam specific quality may be indicated in a number of different manners, some of which may be based on a RS, such as a SSB or a CSI-RS. The term beam refers to a RS. For example, beam specific quality may be indicated by RS received power (RSRP), RS received quality (RSRQ), signal to interference plus noise ratio (SINR), or the like.

[0051] 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 (e.g., SSB, CSI-RS) that fulfilled the event. In LTM-3, which may be referred to as relative threshold event, a beam of a serving cell is referred as the reference resource / beam. In LTM-4, which may be referred to as absolute threshold event, the beam of a candidate cell may be any of the candidate cell RSs that are configured for measurement.

[0052] As agreed, both types of RSs, namely, SSB and CSI-RSs, may be configured to perform the beam measurements for LTM reporting events. For event evaluation, beams of candidate cells (referred to at times as candidate beams) can be determined based on the configured RSs of the candidate cells (referred to as candidate RSs) in the LTM configuration, which may be SSBs and / or CSI-RSs associated with the candidate cell.For the serving cell beam, the current beam (i.e., a beam corresponding to the indicated TCI state) in the serving cell may be used for event evaluation. The RS from the current beam can be derived from the QCL RS of the indicated TCI state or from the QCL RS, which is QCL’ed with the QCL RS of the indicated TCI state.

[0053] A working assumption has been made that the same RS type (SSB or CSI-RS) should be used for both the serving and candidate cells in events LTM-3 and LTM-5. But in scenarios where the serving beam (the beam from the serving cell used for event evaluation) and candidate beam (the beam from a candidate cell used for event evaluation) are associated with different RS types (e.g., the serving cell beam has a QCLRS based on SSB, and the candidate RS is a CSI-RS), it is unclear how the event evaluation should be conducted for LTM-3 and LTM-5, and what RS information should be reported in a measurement report when the LTM reporting event is fulfilled.

[0054] The issues and the example implementations described herein are also applicable for beam management enhancement being considered under discussion of MIMO enhancements with UE-initiated / event-driven beam management, where 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. This is used for intra or inter-cell beam switching operations (without any cell change). When an event is evaluated using the quality of the serving beam (e.g., the current beam or associated with the indicated TCI state), and a candidate beam (e.g., associated with one of configured RSs, or associated with one of the the activated TCI states), the UE may be required to use the same type of RS (SSB or CSI-RS) for event evaluation.

[0055] In view of the foregoing, example implementations of the present disclosure provide solutions for evaluating events when the RS type of the RS derived for the serving beam (referred to as the serving RS herein) and the RS type of the RS configured for a candidate beam (referred to as the candidate RS herein) are different. Example implementations of the present disclosure will be primarily described in the context of LTM reporting event evaluation. In this context, the serving beam is associated with an RS of a serving cell, and the candidate beam is associated with an RS of a candidate cell. It should be understood, however, that example implementations are equally applicable for evaluating other types of events, such as for event-driven beam management.

[0056] According to some example implementations, the UE 110 may determine a RS associated with a candidate RS for event evaluation which has the same RS type as the serving RS; and the UE may evaluate reporting event(s), such as LTM reporting event(s), based on measurements for the determined RS and serving RS. The UE may send a measurement report including information of the candidate RS even when the reporting event evaluation was performed on a different RS associated with the candidate RS. And in the case when there are multiple candidate RSs (associated with multiple candidate beams to be considered for event evaluation) for which the derived RS is thesame, the event evaluation and corresponding reporting may be performed on less than all (e.g., only one) candidate RS.

[0057] Some example implementations of the present disclosure therefore provide a UE 110 that may receive an event-triggered LI measurement reporting configuration including reporting event(s) associated with a serving beam / cell and candidate beam / cell(s), and that indicates RSs of the candidate beam / cell(s) to monitor for the reporting event(s). The UE may determine a RS associated with the serving beam / cell (a serving RS) and a RS associated with a candidate beam / cell (a candidate RS) are different types of RS (e.g., SSB, CSI-RS). The UE may determine a second RS associated with one of the serving beam / cell or the candidate beam / cell that is the same type of RS as the RS associated with the other of the serving beam / cell or the candidate beam / cell. The UE may then perform an evaluation of the reporting event(s) based on LI measurements of the second RS associated with the one of the serving beam / cell or the candidate beam / cell and the RS associated with the other of the serving beam / cell or the candidate beam / cell.

[0058] In some examples, the UE may receive two event-triggered LI measurement reporting configurations for the reporting event(s). One of the configurations may compare a serving RS of a first type (e.g., SSB) against the candidate RS of the first type, and the other of the configurations may compare a serving RS of a second type (e.g., CSI-RS) against the candidate RS of the second type. Alternatively, the event-triggered LI measurement reporting configuration may point to two resource sets for the candidate beam / cell, one including a resource set of RS(s) of the first type, and another including a resource set of RS(s) of the second type.

[0059] The UE 110 may send a measurement report to the serving beam / cell triggered by a determination that a reporting event of the reporting event(s) is fulfilled based on the evaluation. In some examples, the measurement report includes information that indicates whether the evaluation was performed using the serving RS and the candidate RS, or the evaluation was performed using the second RS and the serving RS / candidate RS. In some other examples in which the measurement report does not include this information, the network may determine which RS the UE used for the reporting event evaluation based on the serving RS.

[0060] In some examples, the second RS is associated with the serving beam / cell (a second serving RS), and the evaluation is performed based on LI measurements of the second serving RS and the candidate RS. In other examples, the second RS is associated with the candidate beam / cell (a second candidate RS), and the evaluation is performed based on LI measurements of the second candidate RS and the serving RS. In some of these other examples, the measurement report may include RS identifier (ID) information for the candidate RS for the candidate beam / cell for which the second candidate RS is determined for the evaluation. Here, the RS ID information may refer to index or identifier value of SSB or CSI-RS configured in the measurement set, or RS ID values are determined based on the listing order of RSs in the measurement set configuration instead of the index or identified value. Additionally or alternatively, for example, the measurement report may include RS ID information for the second candidate RS. Additionally, the measurement report may include LI measurements (e.g., RSRP, SINR) for the second candidate RS which was used during the event evaluation.

[0061] The measurement report may also include information (e.g., one-bit indication) that indicates the evaluation was performed using the second candidate RS. For example, a one-bit field may be included in the report (e.g., in a report sent via a MAC CE or as uplink control information over the physical uplink control channel or physical uplink shared channel) to indicate whether the evaluation was performed using the second RS. This one-bit field can be reported alongside the RS information (e.g., RS ID or LI measurement). If the bit field is set to one value (e.g., 1), it indicates that the RS ID in the report is associated with the RS used for event evaluation. If the bit field is set to another value (e.g., 0), it indicates that the RS ID in the report is associated with the RS not used for event evaluation, and a second RS was derived for the event evaluation.

[0062] In some examples in which the event- triggered LI measurement reporting configuration indicates multiple candidate RSs (e.g., N candidate RSs, where N > 1), the second candidate RS may be the same for the multiple RSs. This may occur, for example, when multiple candidate CSLRSs share the same SSB as the QCL reference or source RS (e.g., the SSB is transmitted via a wider beam, and the CSI-RSs are transmitted via narrower beams). In this regard, the multiple candidate RSs may be associated with the same second candidate RS in terms of QCL relation.

[0063] In some examples including the multiple candidate RSs for which the second candidate RS is the same, the reporting event may be triggered for at least one of the multiple candidate RSs (using the second candidate RS in the evaluation). The measurement report may include RS ID information for one or more but less than all (M <= N) of the multiple candidate RSs. In one specific example, the measurement report may include RS ID and / or LI measurement information for only one (M = 1) of the multiple candidate RSs. In some of these examples, the UE may autonomously select the M out of N candidate RSs to report, or the M candidate RSs to report may be determined based on information such as network-configured priority information or measurement based information (if the UE is also measuring the candidate RS in addition to the second candidate RS).

[0064] In some examples, the serving RS is a S SB associated with the serving beam / cell (a serving SSB), and the candidate RS associated with a candidate beam / cell is a CSI-RS (a candidate CSI-RS). In some of these examples, the second candidate RS determined for the evaluation is a SSB associated with the candidate CSI-RS (a candidate SSB). In case of beam management, this may happen when the serving RS is a SSB associated with the serving beam (a serving SSB), and the candidate RS is a CSI-RS associated with the candidate beam (a candidate CSI-RS), and the second candidate RS determined for the evaluation is a SSB associated with the candidate CSI-RS. The UE 110 may determine the candidate SSB in a number of different manners. In this regard, the candidate SSB may be the QCL source (QCL’ed) of the candidate CSI-RS, or a QCL RS configured in a TCI associated with the candidate CSI-RS (e.g., given in qcl- InfoPeriodicCSI-RS for a periodic CSI-RS). The evaluation may then be performed based on the LI measurements of the candidate SSB and the serving SSB.

[0065] In some examples in which the second candidate RS is a candidate SSB, the measurement report may include RS ID information for the candidate CSI-RS for which the candidate SSB is determined for the evaluation. In this case, the RS ID information may refer to index or identifier value CSI-RS configured in the measurement set, or RS ID is determined based on the listing order of CSI-RS s in the measurement set configuration. Additionally or alternatively, for example, the measurement report may include RS ID information for the candidate SSB, i.e., SSB index. Additionally, themeasurement report may include LI measurement of candidate SSB used in the event evaluation. The measurement report may also include information that indicates the evaluation was performed using the candidate SSB. For example, a one-bit field may be included in the report to indicate whether the evaluation was performed using the CSLRS or SSB. If the RS ID information in the report is associated with the candidate CSLRS, the bit field is set to one value (e.g., 1) to indicate that configured candidate CSLRS was not used for event evaluation, instead a second RS, SSB, was derived for the event evaluation.

[0066] In some examples in which the event- triggered LI measurement reporting configuration indicates multiple candidate CSLRSs, the candidate SSB maybe the same for the multiple candidate CSLRSs. In some of these examples, the measurement report may include RS ID information (either ID information of configured CSLRSs or ID information of SSB derived from candidate CSLRSs) and / or LI measurements for one or more but less than all of the multiple candidate CSLRSs. When the event-triggered LI measurement reporting configuration indicates a RS set of three candidate CSLRSs (N = 3), for example, the three candidate CSLRSs may be associated with the same candidate SSB. The evaluation may be performed using the candidate SSB (instead of the candidate CSLRSs), and the UE 110 may report information (RS IDs and / or LI measurements) for one or more but less than all (e.g., M = 1) of the three (N) candidate CSLRSs.

[0067] FIG. 5 illustrates a signaling chart 500 of a procedure for event-based reporting of LI measurements, according to some example implementations. In some examples, the procedure may be carried out during an LTM procedure, such as shown in FIG. 3. In this regard, the procedure may be carried out to determine when to send an LI measurement report, and send the LI measurement report, as indicated at step 305 of FIG. 3.

[0068] As shown in FIG. 5, a serving cell 508 (provided by a serving gNB 206) may at step 501 send, to the UE 110, a LTM configuration (candidate measurement RS configuration), and a reporting configuration (event-triggered reporting configuration) for LTM reporting event(s). In the example, the LTM configuration indicates a RS set associated with a candidate cell 510. The RS set includes a number of CSLRS (e.g., CSI- RS1, CSLRS2, ... CSLRS n). As shown in FIG. 3, the configurations may be sent by theserving gNB to the UE as part of an LTM candidate configuration at step 302.

[0069] As shown at 502, the RS associated with the serving cell 508 is a SSB, which is different from the type of RS indicated for the candidate cell 510 in the LTM configuration. For the RSs associated with the candidate cell 510 (i.e., the candidate RSs), the UE 110 may at step 503 derive candidate SSBs associated with the candidate CSI-RSs. The UE may then at step 504 perform measurements on SSB of the serving cell and one or more different ones of the candidate SSBs derived from the candidate CSI- RSs.

[0070] The UE 110 may perform an evaluation of the LTM reporting event(s) based on the measurements, and the UE may at step 505 determine that an LTM reporting event has been fulfilled (triggered) based on the evaluation. The UE may then prepare a measurement report triggered by the determination.

[0071] The serving cell 508 may at step 506 provide the UE 110 with a UL resource allocation that includes an UL grant. The UE may at step 506 transmit a MAC packet data unit (PDU) including the measurement report to the serving cell on an uplink shared channel (UL-SCH) in the uplink grant. Although shown after the UE determines that the reporting event has been triggered, the UL resource allocation may be provided to the UE at any time before the MAC CEs for the uplink grant are determined. The measurement report may include, for example, RS identifier (ID) information for the candidate CSI- RSs for which the LTM reporting event triggered, along with measurements on the associated SSBs. In some examples in which CSI-RSs are associated with the same SSB, the measurement report may include information for less than all (e.g., only a single) of the CSI-RSs.

[0072] FIG. 6 is a flowchart illustrating various steps in a method 600 according to various example implementations. The method includes receiving an event-triggered layer 1 (LI) measurement reporting configuration including one or more reporting events associated with a serving beam and at least one candidate beam, and that indicates one or more reference signals of the one or more candidate beams to monitor for the one or more reporting events, as shown at block 602. The method includes determining a reference signal associated with the serving beam and a reference signal associated with a candidate beam are different types of reference signal, as shown at block 604. Themethod includes determining a second reference signal associated with one of the serving beam or the candidate beam that is the same type of reference signal as the reference signal associated with the other of the serving beam or the candidate beam, as shown at block 606. The method includes performing an evaluation of the one or more reporting events based on LI measurements of the second reference signal associated with the one of the serving beam or the candidate beam and the reference signal associated with the other of the serving beam or the candidate beam, as shown at block 608. And the method includes sending a measurement report to the serving beam triggered by a determination that an reporting event of the one or more reporting events is fulfilled based on the evaluation, as shown at block 610.

[0073] In some examples, the one or more reporting events are for lower-layer triggered mobility (LTM), the serving beam is associated with a reference signal of a serving cell, and the candidate beam is associated with a reference signal of a candidate cell.

[0074] In some examples, the reference signal associated with one of the serving beam or the candidate beam is a synchronization signal block (SSB), and the reference signal associated with the other of the serving beam or the candidate beam is a channel state information reference signal (CSLRS).

[0075] In some examples, the second reference signal is associated with the serving beam, and the evaluation is performed at block 608 based on LI measurements of the second reference signal associated with the serving beam and the reference signal associated with the candidate beam.

[0076] In some examples, the measurement report includes information that indicates the evaluation was performed using the second reference signal.

[0077] In some examples, the second reference signal is associated with the candidate beam, and the evaluation is performed at block 608 based on LI measurements of the second reference signal associated with the candidate beam and the reference signal associated with the serving beam.

[0078] In some examples, the measurement report includes reference signal identifier information for the reference signal associated with the candidate beam for which the second reference signal is determined for the evaluation.

[0079] In some examples, the measurement report includes information that indicates the evaluation was performed using the second reference signal.

[0080] In some examples, the event-triggered LI measurement reporting configuration indicates multiple reference signals associated with the multiple candidate beams, and the second reference signal is the same for the multiple reference signals. In some of these examples, the evaluation is performed on one or more but less than all of the multiple reference signals associated with the multiple candidate beams, and the measurement report includes reference signal identifier information for the one or more but less than all of the multiple reference signals.

[0081] In some examples, the measurement report includes at least one of reference signal identifier information or LI measurements for the second reference signal which is determined for the evaluation.

[0082] In some examples, the reference signal associated with the serving beam is a synchronization signal block (SSB), and the reference signal associated with a candidate beam is a channel state information reference signal (CS RS). In some of these examples, the second reference signal associated with the candidate beam is a SSB, and the evaluation is performed at block 608 based on the LI measurements of the SSB associated with the candidate beam and the SSB associated with the serving beam.

[0083] In some examples, determining the second reference signal at block 606 includes determining the SSB associated with the candidate beam that is a quasi colocation (QCL) source of the CSLRS associated with the candidate beam.

[0084] In some examples, determining the second reference signal at block 606 includes determining the SSB associated with the candidate beam that is a quasi colocation (QCL) reference signal configured in a transmission configuration indicator (TCI) associated with the CSLRS associated with the candidate beam.

[0085] In some examples, the measurement report includes reference signal identifier information for the CSLRS associated with the candidate beam for which the SSB is determined for the evaluation.

[0086] In some examples, the measurement report includes information that indicates the evaluation was performed using the SSB.

[0087] In some examples, the event-triggered LI measurement reporting configuration indicates multiple CSI-RSs associated with the multiple candidate beams, and the SB is the same for the multiple CSI-RSs. In some of these examples, the evaluation is performed on one or more but less than all of the multiple CSI-RSs associated with the candidate beam, and the measurement report includes reference signal identifier information for the one or more but less than all of the multiple CSI-RSs.

[0088] In some examples, the measurement report includes at least one of reference signal identifier information or LI measurements for the SSB which is determined for the evaluation.

[0089] 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, serving cell 508 and / or candidate cell 510, 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.

[0090] According to some example implementations, at least some of the method 600 described with respect to FIG. 6 may be carried out by an apparatus comprising means for performing functions corresponding steps of the method. Examples of a suitable apparatus may include a user equipment, user device, user terminal or the like.

[0091] 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. Theapparatus 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.

[0092] 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).

[0093] 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 of executing 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.

[0094] 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 nonvolatile memory, and may be fixed or removable. Examples of suitable memory includerecording 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.

[0095] 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.

[0096] 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 of suitable communication interfaces include a network interface controller (NIC), wireless NIC (WNIC) or the like.

[0097] 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.

[0098] 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 hardware-based computer systems and / or processing circuitry which perform the specified functions, or combinations of special purpose hardware and program code instructions.

[0099] 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 example implementations of the present disclosure is well within the scope of a person of ordinary skill in the art.

[0100] 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 mayalso 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.

[0101] 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.

[0102] As explained above and reiterated below, the present disclosure includes, without limitation, the following example implementations.

[0103] Clause 1. A method comprising: receiving an event-triggered layer 1 (LI) measurement reporting configuration including one or more reporting events associated with a serving beam and at least one candidate beam, and that indicates one or more reference signals of the one or more candidate beams to monitor for the one or more reporting events; determining a reference signal associated with the serving beam and a reference signal associated with a candidate beam are different types of reference signal; determining a second reference signal associated with one of the serving beam or the candidate beam that is the same type of reference signal as the reference signal associated with the other of the serving beam or the candidate beam ; performing an evaluation of the one or more reporting events based on LI measurements of the second reference signal associated with the one of the serving beam or the candidate beam and the referencesignal associated with the other of the serving beam or the candidate beam; and sending a measurement report to the serving cell triggered by a determination that a reporting event of the one or more reporting events is fulfilled based on the evaluation.

[0104] Clause 2. The method of clause 1, wherein the one or more reporting events are for lower-layer triggered mobility (LTM), the serving beam is associated with a reference signal of a serving cell, and the candidate beam is associated with a reference signal of a candidate cell.

[0105] Clause 3. The method of clause 1 or clause 2, wherein the reference signal associated with one of the serving beam or the candidate beam is a synchronization signal block (SSB), and the reference signal associated with the other of the serving beam or the candidate beam is a channel state information reference signal (CSI-RS).

[0106] Clause 4. The method of any of clauses 1 to 3, wherein the second reference signal is associated with the serving beam, and the evaluation is performed based on LI measurements of the second reference signal associated with the serving beam and the reference signal associated with the candidate beam.

[0107] Clause 5. The method of any of clauses 1 to 4, wherein the measurement report includes information that indicates the evaluation was performed using the second reference signal.

[0108] Clause 6. The method of any of clauses 1 to 5, wherein the second reference signal is associated with the candidate beam, and the evaluation is performed based on LI measurements of the second reference signal associated with the candidate beam and the reference signal associated with the serving beam.

[0109] Clause 7. The method of clause 6, wherein the measurement report includes reference signal identifier information for the reference signal associated with the candidate beam for which the second reference signal is determined for the evaluation.

[0110] Clause 8. The method of clause 7, wherein the measurement report includes information that indicates the evaluation was performed using the second reference signal.

[0111] Clause 9. The method of any of clauses 6 to 8, wherein the event-triggered LI measurement reporting configuration indicates multiple reference signals associated with the multiple candidate beams, and the second reference signal is the same for the multiplereference signals, and wherein the evaluation is performed on one or more but less than all of the multiple reference signals associated with the multiple candidate beams, and the measurement report includes reference signal identifier information for the one or more but less than all of the multiple reference signals.

[0112] Clause 10. The method of any of clauses 6 to 9, wherein the measurement report includes at least one of reference signal identifier information or LI measurements for the second reference signal which is determined for the evaluation.

[0113] Clause 11. The method of any of clauses 6 to 10, wherein the reference signal associated with the serving beam is a synchronization signal block (SSB), and the reference signal associated with a candidate beam is a channel state information reference signal (CSI-RS), and wherein the second reference signal associated with the candidate beam is a SSB, and the evaluation is performed based on the LI measurements of the SSB associated with the candidate beam and the SSB associated with the serving beam.

[0114] Clause 12. The method of clause 11, wherein determining the second reference signal includes determining the SSB associated with the candidate beam that is a quasi co-location (QCL) source of the CSI-RS associated with the candidate beam, or a QCL reference signal configured in a transmission configuration indicator (TCI) associated with the CSI-RS associated with the candidate beam.

[0115] Clause 13. The method of clause 11 or clause 12, wherein the measurement report includes reference signal identifier information for the CSI-RS associated with the candidate beam for which the SSB is determined for the evaluation.

[0116] Clause 14. The method of clause 13, wherein the measurement report includes information that indicates the evaluation was performed using the SSB.

[0117] Clause 15. The method of any of clauses 11 to 14, wherein the event-triggered LI measurement reporting configuration indicates multiple CSI-RSs associated with the multiple candidate beams, and the SB is the same for the multiple CSI-RSs, and wherein the evaluation is performed on one or more but less than all of the multiple CSI-RSs associated with the candidate beam, and the measurement report includes reference signal identifier information for the one or more but less than all of the multiple CSI-RSs.

[0118] Clause 16. The method of any of clauses 11 to 15, wherein the measurement report includes at least one of reference signal identifier information or LI measurements for the SSB which is determined for the evaluation.

[0119] Clause 17. 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 perform the method of any of clauses 1 to 16.

[0120] Clause 18. An apparatus comprising means for performing the method of any of clauses 1 to 16.

[0121] Clause 19. 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 1 to 16.

[0122] Clause 20. 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 1 to 16.

[0123] Clause 21. 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 1 to 16.

[0124] 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 benefit of 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 theappended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

WHAT IS CLAIMED IS:

1. An apparatus comprising: means for receiving an event-triggered layer 1 (LI) measurement reporting configuration including one or more reporting events associated with a serving beam and at least one candidate beam, and that indicates one or more reference signals of the one or more candidate beams to monitor for the one or more reporting events; means for determining a reference signal associated with the serving beam and a reference signal associated with a candidate beam are different types of reference signal; means for determining a second reference signal associated with one of the serving beam or the candidate beam that is the same type of reference signal as the reference signal associated with the other of the serving beam or the candidate beam; means for performing an evaluation of the one or more reporting events based on LI measurements of the second reference signal associated with the one of the serving beam or the candidate beam and the reference signal associated with the other of the serving beam or the candidate beam; and means for sending a measurement report to the serving cell triggered by a determination that a reporting event of the one or more reporting events is fulfilled based on the evaluation.

2. The apparatus of claim 1, wherein the one or more reporting events are for lower-layer triggered mobility (LTM), the serving beam is associated with a reference signal of a serving cell, and the candidate beam is associated with a reference signal of a candidate cell.

3. The apparatus of claim 1 or claim 2, wherein the reference signal associated with one of the serving beam or the candidate beam is a synchronization signal block (SSB), and the reference signal associated with the other of the serving beam or the candidate beam is a channel state information reference signal (CSI-RS).

4. The apparatus of any of claims 1 to 3, wherein the second reference signal is associated with the serving beam, and the evaluation is performed based on LI-32-measurements of the second reference signal associated with the serving beam and the reference signal associated with the candidate beam.

5. The apparatus of any of claims 1 to 4, wherein the measurement report includes information that indicates the evaluation was performed using the second reference signal.

6. The apparatus of any of claims 1 to 5, wherein the second reference signal is associated with the candidate beam, and the evaluation is performed based on LI measurements of the second reference signal associated with the candidate beam and the reference signal associated with the serving beam.

7. The apparatus of claim 6, wherein the measurement report includes reference signal identifier information for the reference signal associated with the candidate beam for which the second reference signal is determined for the evaluation.

8. The apparatus of claim 7, wherein the measurement report includes information that indicates the evaluation was performed using the second reference signal.

9. The apparatus of any of claims 6 to 8, wherein the event-triggered LI measurement reporting configuration indicates multiple reference signals associated with the multiple candidate beams, and the second reference signal is the same for the multiple reference signals, and wherein the evaluation is performed on one or more but less than all of the multiple reference signals associated with the multiple candidate beams, and the measurement report includes reference signal identifier information for the one or more but less than all of the multiple reference signals.-33-10. The apparatus of any of claims 6 to 9, wherein the measurement report includes at least one of reference signal identifier information or LI measurements for the second reference signal which is determined for the evaluation.

11. The apparatus of any of claims 6 to 10, wherein the reference signal associated with the serving beam is a synchronization signal block (SSB), and the reference signal associated with a candidate beam is a channel state information reference signal (CSI-RS), and wherein the second reference signal associated with the candidate beam is a SSB, and the evaluation is performed based on the LI measurements of the SSB associated with the candidate beam and the SSB associated with the serving beam.

12. The apparatus of claim 11, wherein the means for determining the second reference signal includes means for determining the SSB associated with the candidate beam that is a quasi co-location (QCL) source of the CSI-RS associated with the candidate beam, or a QCL reference signal configured in a transmission configuration indicator (TCI) associated with the CSI-RS associated with the candidate beam.

13. The apparatus of claim 11 or claim 12, wherein the measurement report includes reference signal identifier information for the CSI-RS associated with the candidate beam for which the SSB is determined for the evaluation.

14. The apparatus of claim 13, wherein the measurement report includes information that indicates the evaluation was performed using the SSB.

15. The apparatus of any of claims 11 to 14, wherein the event-triggered LI measurement reporting configuration indicates multiple CSI-RS s associated with the multiple candidate beams, and the SB is the same for the multiple CSI-RS s, and wherein the evaluation is performed on one or more but less than all of the multiple CSLRSs associated with the candidate beam, and the measurement reportincludes reference signal identifier information for the one or more but less than all of the multiple CSI-RSs.

16. The apparatus of any of claims 11 to 15, wherein the measurement report includes at least one of reference signal identifier information or LI measurements for the SSB which is determined for the evaluation.

17. A method comprising: receiving an event-triggered layer 1 (LI) measurement reporting configuration including one or more reporting events associated with a serving beam and at least one candidate beam, and that indicates one or more reference signals of the one or more candidate beams to monitor for the one or more reporting events; determining a reference signal associated with the serving beam and a reference signal associated with a candidate beam are different types of reference signal; determining a second reference signal associated with one of the serving beam or the candidate beam that is the same type of reference signal as the reference signal associated with the other of the serving beam or the candidate beam; performing an evaluation of the one or more reporting events based on LI measurements of the second reference signal associated with the one of the serving beam or the candidate beam and the reference signal associated with the other of the serving beam or the candidate beam; and sending a measurement report to the serving cell triggered by a determination that a reporting event of the one or more reporting events is fulfilled based on the evaluation.

18. The method of claim 17, wherein the reference signal associated with one of the serving beam or the candidate beam is a synchronization signal block (SSB), and the reference signal associated with the other of the serving beam or the candidate beam is a channel state information reference signal (CSI-RS).

19. The method of claim 17 or claim 18, wherein the second reference signal is associated with the serving beam, and the evaluation is performed based on LImeasurements of the second reference signal associated with the serving beam and the reference signal associated with the candidate beam.

20. The method of any of claims 17 to 19, wherein the measurement report includes information that indicates the evaluation was performed using the second reference signal.

21. The method of any of claims 17 to 20, wherein the second reference signal is associated with the candidate beam, and the evaluation is performed based on LI measurements of the second reference signal associated with the candidate beam and the reference signal associated with the serving beam.

22. The method of claim 21, wherein the measurement report includes reference signal identifier information for the reference signal associated with the candidate beam for which the second reference signal is determined for the evaluation.

23. The method of claim 21 or claim 22, wherein the event-triggered LI measurement reporting configuration indicates multiple reference signals associated with the multiple candidate beams, and the second reference signal is the same for the multiple reference signals, and wherein the evaluation is performed on one or more but less than all of the multiple reference signals associated with the multiple candidate beams, and the measurement report includes reference signal identifier information for the one or more but less than all of the multiple reference signals.

24. The method of any of claims 21 to 23, wherein the measurement report includes at least one of reference signal identifier information or LI measurements for the second reference signal which is determined for the evaluation.

25. The method of any of claims 21 to 24, wherein the reference signal associated with the serving beam is a synchronization signal block (SSB), and the-36-reference signal associated with a candidate beam is a channel state information reference signal (CSI-RS), and wherein the second reference signal associated with the candidate beam is a SSB, and the evaluation is performed based on the LI measurements of the SSB associated with the candidate beam and the SSB associated with the serving beam.-37-

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