GB2640874A - Determining and exploiting spatial proximity between reference signals - Google Patents

Abstract

This application is concerned with beam reporting from apparatus such as a user equipment (UE). The apparatus/UE receives reporting configuration information, such as channel state information (CSI) reporting configuration information, indicating different reporting periodicities for different reference signals RS1- RS8. The reference signals are preferably downlink reference signals, such as CSI-RS signals. The reporting periodicities are based on a spatial relationship between the reference signals. The spatial relationship is preferably beam distance. Longer beam reporting periodicities may be configured for beams (b4 and b5) located further away from a currently strongest beam b2 than for beams (b1 and b3) located adjacent to the strongest beam. This is because there is a lower likelihood of the UE transitioning to a non-adjacent beam than to an adjacent beam.

Description

DESCRIPTION

DETERMINING AND EXPLOITING SPATIAL PROXIMITY BETWEEN REFERENCE

SIGNALS

tECHNICAL FIELD

[0001] The present application relates to wireless communications and, in particular, to methods, apparatuses and computer program products for determining and exploiting spatial proximity between reference signals.

BACKGROUND

[0002] It is known that in beam management procedures, user equipment may be configured or may initiate beam measurements and/or reporting to assist network to acquire the best/preferred beam for data and/or control transmissions.

SUMMARY

100031 Various aspects of examples of the invention are set out in the claims.

100041 In accordance with one aspect, an apparatus comprising: at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to: determine a spatial relationship between a pair of reference signals, comprising a first reference signal and a second reference signal, among a set of reference signals transmitted by another apparatus, wherein the spatial relationship comprises a beam distance between a first beam associated with the first reference signal and a second beam associated with the second reference signal.

[0005] In accordance with one aspect, a method comprising: determining a spatial relationship between a pair of reference signals, comprising a first reference signal and a second reference signal, among a set of reference signals transmitted by another apparatus, wherein the spatial relationship comprises a beam distance between a first beam associated with the first reference signal and a second beam associated with the second reference signal.

[0006] In accordance with one aspect, a non-transitory computer-readable medium comprising program instructions stored thereon for performing at least the following: determining a spatial relationship between a pair of reference signals, comprising a first reference signal and a second reference signal, among a set of reference signals transmitted by another apparatus, wherein the spatial relationship comprises a beam distance between a first beam associated with the first reference signal and a second beam associated with the second reference signal.

[0007] In accordance with one aspect, an apparatus comprising means for performing: determining a spatial relationship between a pair of reference signals, comprising a first reference signal and a second reference signal, among a set of reference signals transmitted by another apparatus, wherein the spatial relationship comprises a beam distance between a first beam associated with the first reference signal and a second beam associated with the second reference signal.

[0008] In accordance with one aspect, an apparatus comprising: at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to: transmit control information to a user equipment, wherein the control information comprises or indicates at least one of: for each pair of reference signals in the set of reference signals, a beam distance between their associated beams, or a permutation index indicating an ordering of the set of reference signals, wherein consecutive entries correspond to signals associated with adjacent beams.

[0009] In accordance with one aspect, a method comprising: transmitting control information to a user equipment, wherein the control information comprises or indicates at least one of: for each pair of reference signals in the set of reference signals, a beam distance between their associated beams, or a permutation index indicating an ordering of the set of reference signals, wherein consecutive entries correspond to signals associated with adjacent beams.

[0010] In accordance with one aspect, a non-transitory computer-readable medium comprising program instructions stored thereon for performing at least the following: transmitting control information to a user equipment, wherein the control information comprises or indicates at least one of: for each pair of reference signals in the set of reference signals, a beam distance between their associated beams, or a permutation index indicating an ordering of the set of reference signals, wherein consecutive entries correspond to signals associated with adjacent beams.

100111 In accordance with one aspect, an apparatus comprising means for performing: transmitting control information to a user equipment, wherein the control information comprises or indicates at least one of: for each pair of reference signals in the set of reference signals, a beam distance between their associated beams, or a permutation index indicating an ordering of the set of reference signals, wherein consecutive entries correspond to signals associated with adjacent beams.

[0012] In accordance with one aspect, an apparatus comprising: at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to: receive reporting configuration information indicating a first reporting periodicity for a first reference signal and a second reporting periodicity for a second reference signal, wherein a relative difference between the first reporting periodicity and the second reporting periodicity is based on a spatial relationship between the first reference signal and the second reference signal, report measurements on the first reference signal according to the first reporting periodicity and report measurements on the second reference signal according to the second reporting periodicity.

[0013] In accordance with one aspect, a method comprising: receiving reporting configuration information indicating a first reporting periodicity for a first reference signal and a second reporting periodicity for a second reference signal, wherein a relative difference between the first reporting periodicity and the second reporting periodicity is based on a spatial relationship between the first reference signal and the second reference signal, reporting measurements on the first reference signal according to the first reporting periodicity and reporting measurements on the second reference signal according to the second reporting periodicity.

[0014] In accordance with one aspect, a non-transitory computer-readable medium comprising program instructions stored thereon for performing at least the following: receiving reporting configuration information indicating a first reporting periodicity for a first reference signal and a second reporting periodicity for a second reference signal, wherein a relative difference between the first reporting periodicity and the second reporting periodicity is based on a spatial relationship between the first reference signal and the second reference signal, reporting measurements on the first reference signal according to the first reporting periodicity and reporting measurements on the second reference signal according to the second reporting periodicity.

[0015] In accordance with one aspect, an apparatus comprising means for performing: receiving reporting configuration information indicating a first reporting periodicity for a first reference signal and a second reporting periodicity for a second reference signal, wherein a relative difference between the first reporting periodicity and the second reporting periodicity is based on a spatial relationship between the first reference signal and the second reference signal, reporting measurements on the first reference signal according to the first reporting periodicity and reporting measurements on the second reference signal according to the second reporting periodicity.

[0016] In accordance with one aspect, an apparatus comprising: at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to: receive event configuration information indicating one or more of: at least one first event condition for triggering measurement and/or reporting associated with at least one adjacent beam, or at least one second event condition for triggering measurement and/or reporting associated with at least one beam within a certain beam distance.

[0017] In accordance with one aspect, a method comprising: receiving event configuration information indicating one or more of: at least one first event condition for triggering measurement and/or reporting associated with at least one adjacent beam, or at least one second event condition for triggering measurement and/or reporting associated with at least one beam within a certain beam distance.

[0018] In accordance with one aspect, a non-transitory computer-readable medium comprising program instructions stored thereon for performing at least the following: receiving event configuration information indicating one or more of: at least one first event condition for triggering measurement and/or reporting associated with at least one adjacent beam, or at least one second event condition for triggering measurement and/or reporting associated with at least one beam within a certain beam distance.

[0019] In accordance with one aspect, an apparatus comprising means for performing: receiving event configuration information indicating one or more of: at least one first event condition for triggering measurement and/or reporting associated with at least one adjacent beam, or at least one second event condition for triggering measurement and/or reporting associated with at least one beam within a certain beam distance.

100201 In accordance with one aspect, an apparatus comprising: at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to: transmit, to a user equipment, reporting configuration information indicating a first reporting periodicity for a first reference signal and a second reporting periodicity for a second reference signal, wherein a relative difference between the first reporting periodicity and the second reporting periodicity is based on a spatial relationship between the first reference signal and the second reference signal, receive measurements on the first reference signal according to the first reporting periodicity and receive measurements on the second reference signal according to the second reporting periodicity.

[0021] In accordance with one aspect, a method comprising: transmitting, to a user equipment, reporting configuration information indicating a first reporting periodicity for a first reference signal and a second reporting periodicity for a second reference signal, wherein a relative difference between the first reporting periodicity and the second reporting periodicity is based on a spatial relationship between the first reference signal and the second reference signal, receiving measurements on the first reference signal according to the first reporting periodicity and receiving measurements on the second reference signal according to the second reporting periodicity.

[0022] In accordance with one aspect, a non-transitory computer-readable medium comprising program instructions stored thereon for performing at least the following: transmitting, to a user equipment, reporting configuration information indicating a first reporting periodicity for a first reference signal and a second reporting periodicity for a second reference signal, wherein a relative difference between the first reporting periodicity and the second reporting periodicity is based on a spatial relationship between the first reference signal and the second reference signal, receiving measurements on the first reference signal according to the first reporting periodicity and receiving measurements on the second reference signal according to the second reporting periodicity.

[0023] In accordance with one aspect, an apparatus comprising means for performing: transmitting, to a user equipment, reporting configuration information indicating a first reporting periodicity for a first reference signal and a second reporting periodicity for a second reference signal, wherein a relative difference between the first reporting periodicity and the second reporting periodicity is based on a spatial relationship between the first reference signal and the second reference signal, receiving measurements on the first reference signal according to the first reporting periodicity and receiving measurements on the second reference signal according to the second reporting periodicity.

[0024] In accordance with one aspect, an apparatus comprising: at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to: transmit, to a user equipment, event configuration information indicating one or more of: at least one first event condition for triggering measurement and/or reporting associated with at least one adjacent beam, or at least one second event condition for triggering measurement and/or reporting associated with at least one beam within a certain beam distance.

[0025] In accordance with one aspect, a method comprising: transmitting, to a user equipment, event configuration information indicating one or more of: at least one first event condition for triggering measurement and/or reporting associated with at least one adjacent beam, or at least one second event condition for triggering measurement and/or reporting associated with at least one beam within a certain beam distance.

[0026] In accordance with one aspect, a non-transitory computer-readable medium comprising program instructions stored thereon for performing at least the following: transmitting, to a user equipment, event configuration information indicating one or more of: at least one first event condition for triggering measurement and/or reporting associated with at least one adjacent beam, or at least one second event condition for triggering measurement and/or reporting associated with at least one beam within a certain beam distance.

[0027] In accordance with one aspect, an apparatus comprising means for performing: transmitting, to a user equipment, event configuration information indicating one or more of: at least one first event condition for triggering measurement and/or reporting associated with at least one adjacent beam, or at least one second event condition for triggering measurement and/or reporting associated with at least one beam within a certain beam distance.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] For a more complete understanding of example embodiments of the present invention, reference is now made to the following descriptions taken in connection with the accompanying drawings in which: [0029] Figure 1 is a diagram illustrating features as described herein; [0030] Figure 2 is a diagram illustrating features as described herein; [0031] Figure 3 is a diagram illustrating features as described herein; [0032] Figure 4 is a block diagram of an apparatus in accordance with an example

embodiment of the present disclosure;

[0033] Figure 5 is a flow chart illustrating steps as described herein; [0034] Figure 6 is a diagram illustrating features as described herein; [0035] Figure 7 is a flow chart illustrating steps as described herein; [0036] Figure 8 is a flow chart illustrating steps as described herein; [0037] Figure 9 is a flow chart illustrating steps as described herein; [0038] Figure 10 is a flow chart illustrating steps as described herein; and 100391 Figure 11 is a flow chart illustrating steps as described herein.

DETAILED DESCRIPTION OF EMBODIMENTS

100401 The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows: 3GPP third generation partnership project A2X aircraft to everything CSI-RS channel state information reference signal CU central unit FR2 frequency range 2 Ll Layer 1 LOS line of sight LTM Layer 2 mobility MCG master cell group -7 -NLOS non-line-of-sight NR new radio QCL quasi-colocated RSRP reference signal received power SCG secondary cell group SL sidelink SSB synchronization signal block Tel transmission configuration indicator TRP transmission reception point UE user equipment V2X vehicle to everything [0041] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

[0042] Some embodiments of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all, embodiments of the disclosure are shown. Indeed, various embodiments of the disclosure may be embodied in many different forms and should not be construed as limited to the example embodiments set forth herein; rather, these example embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout. As used herein, the terms "data," "content," "information," and similar terms may be used interchangeably to refer to data capable of being transmitted, received and/or stored in accordance with some embodiments of the present disclosure. Thus, use of any such terms should not be taken to limit the spirit and scope of example embodiments of the present

disclosure.

[0043] Additionally, as used herein, the term 'circuitry' refers to (a) hardware-only circuit implementations (e.g., implementations in analog circuitry and/or digital circuitry); (b) combinations of circuits and computer program product(s) comprising software and/or firmware instructions stored on one or more computer readable memories that work together to cause an apparatus to perform one or more functions described herein; and (c) circuits, such as, for example, a microprocessor(s) or a portion of a microprocessor(s), that use software or firmware -8 -for operation even if the software or firmware is not physically present. This definition of circuitry' applies to all uses of this term herein, including in any claims. As a further example, as used herein, the term 'circuitry' also includes an implementation comprising one or more processors and/or portion(s) thereof and accompanying software and/or firmware. As another example, the term 'circuitry' as used herein also includes, for example, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, other network device (such as a core network apparatus), field programmable gate array, and/or other computing device.

[0044] In legacy beam management procedures, the network may configure/activate frequent periodic or semi-persistent beam reporting, for example, for N best beams and corresponding Ll-RSRPs, or triggers frequent aperiodic beam reporting to timely acquire the best/preferred beam for data/control transmissions. However, this clearly results in large uplink reporting overhead and control signaling overhead. At the same time, if less frequent beam reporting is configured, the network could not always acquire the best/preferred beam(s) because the beam reporting by user equipment may be outdated, thus leading to performance degradation. Given that UE has better and more-timely knowledge of beam quality changes, UE-initiated beam reporting procedure can lead to more timely beam reports yet with reduced reporting overhead. Under such a procedure, if the UE determines that, for example, current beam(s) quality becomes poor, UE can trigger beam reporting without the network needing to configure or trigger frequent reporting.

[0045] One objective from 3GPP is to specify enhancement to the beam management procedure for reducing overhead and/or latency: 7. Specify enhancement to facilitate GE-initiated/event-driven beam management for reducing overhead and/or latency, assuming the unified TCI while leveraging (as much as possible) legacy CS! measurement and reporting configuration frameworks, targeting FR2 and s7-RP with intra-and inter-cell beam management a. UL signaling contents) (and procedure(s) as required) for UE-initiated/eventdriven beam reporting facilitating fast beam switching b. UL signaling medium/container considering the UE-initiated/event-driven nature of the UL transmission, designed primarily for the purpose of beam reporting -9 - [0046] Layer 2 mobility (LTM) was introduced in 3GPP Re1-1 8 and can offer improvements in handover latency and interruption time compared to Layer 3 based mobility. However, LTM as introduced in Rel-18 also has a number of limitations compared to Layer 3 mobility. The Rel19 work item aims to remove a number of these limitations.

[0047] Layer 3 mobility uses layer 3 measurement reporting which supports UE evaluated events for triggering of measurement reports and reduces signaling overhead compared to periodic measurement reporting. Such event triggering is not supported by the Ll measurements that are used for LTM mobility.

[0048] Layer 1 (L1) measurements for LTM procedures are limited to SSB measurements.

Expanding Ll measurements to include CSI-RS can address this limitation and can be expected to enable greater throughput on the target cell immediately after cell switch.

[0049] Another objective from 3GPP is measurement enhancement to support LTM: * Measurements related enhancements for purpose of supporting LTM: o Measurement related enhancements are applicable to lntra-CLI MCG/SCG LTM and Inter-CU MCG/SCG LTM o Specify necessary components to support event triggered L7 measurement reporting [RANI, RAN]) * RAN7 and RAN2 to progress independently on the event triggered measurements objectives of their respective MIMO and Mobility enhancement I/Vls. Review progress at RAIW7 05 to see iranv modification of objectives is required to avoid/manage any overlap in the work o Specify support for CSI-RS measurements for LTM procedures and enable CSI-PS based beam management, and/or other necessary physical layer operations on candidate cells before LTM (RANT) [0050] In 3GPP new radio (NR) specification, a device receiver can assume that the radio channels corresponding to two different antenna ports have the same large-scale properties in terms of specific parameters such as average delay spread, Doppler spread/shift, average delay, average gain, and spatial Rx parameters if and only if the antenna ports are specified as being quasi-colocated (QCL). Whether or not two specific antenna ports can be assumed to be quasi-colocated with respect to a certain channel property is in some cases given by the NR specification. In other cases, the device may be explicitly informed by the network by means of -I 0 - signaling if two specific antenna ports can be assumed to be quasi-colocated or not. The general principle of QCL is present already in the later releases of LTE when it comes to the temporal parameters. However, with the extensive support for beamfonning in NR, the QCL framework has been extended to spatial domain. Spatial quasi-colocation or, more formally, quasi-col ocation with respect to receiver parameters is a key part of beam management. Although somewhat vague in its formal definition, in practice spatial QCL between two different signals implies that they are transmitted from the same place and in the same beam. Consequently, if a device knows that a certain receiver beam direction is good for one of the signals, it can assume that the same beam direction is suitable also for reception of the other signal. In a typical situation, the NR specification states that certain transmissions, for example, PDSCH and PDCCH transmissions, are spatially quasi-colocated with specific reference signals, for example, CSI-RS or SS block. The device may have decided on a specific receiver beam direction based on measurements on the reference signal in question and the device can then assume that the same beam direction is a good choice also for the PDSCH/PDCCH reception.

100511 Figure 1 illustrates an example of intra-cell beam measurement scenario in frequency range 2 (FR2), where a UE may be configured to perform measurements on a set of reference signals {RS1, RS8}, for example, SSB and/or CST-RS, transmitted by one or more network entity. The different beams available within a codebook for transmitting the different reference signals {RS1, ..., RS8} may be viewed as a quantization or discretization of a certain region of angular space. It is noted that the term "beam" herein is used synonymously with "spatial filter" or "spatial-domain filter", as found in 3GPP specifications. In this example, an angular region spanning 80 deg in azimuth is discretized into 8 angular sub-regions each spanning 10 deg in azimuth. At present, it is not possible for the UE to make any assumptions regarding the angular spacing among the beams used to transmit such a set of reference signals {RS1, ..., RS8}.

100521 In this example, the UE may initially perform measurements on the entire set of reference signals {RS1, ..., RS8} and determine that RS2 (transmitted on beam b2) is the strongest one. As the UE moves and RS2 becomes weaker, it is likely that either RS1 or RS3, which are transmitted on adjacent beams (bi, b3), become the strongest reference signal. However, as the UE is not aware about such adjacency, it may need to once again perform measurements on the entire set of reference signals {RSI, R58} in order to determine which one is strongest. This is inefficient as, for example, it is highly unlikely that RS8 will be strong anytime soon, given that its associated beam (b8) points to a direction far away from the UE.

[0053] In order to better explain the limitations of the present NR specification, Figure 2 shows an example of SSB-to-CST-RS association using the current QCL framework. Here, according to the known prior art, the subset of CST-RSs CSI-RS2, CST-RS3, CST-RS4} are said to be (spatially) quasi co-located (QCLed) with SSB1, while the subset of CS1-RSs {CSI-RS5, CSI-RS6, CSI-RS2, CSI-RS8} are said to be (spatially) quasi co-located (QCLed) with SSB2. However, the UE lacks any awareness, for example, regarding the spatial proximity of CSI-RS4 and CSI-RS5, which are transmitted on adjacent beams.

[0054] Figure 3 illustrates a further example of sidelink (SL) beam measurement in FR2 between two airborne UEs, namely UE1 and UE2, in an Aircraft-to-Everything (A2X) scenario. In the example embodiment, both beamforming dimensions (azimuth and elevation) are shown. In general, the beam spacing may be different in each dimension, for example, depending on the corresponding beamwidth. For example, a larger beamwidth in one dimension may lead to a larger beam spacing in that dimension.

[0055] One example of an apparatus 40 is depicted in Figure 4. As shown in Figure 4, the apparatus includes, is associated with, or is in communication with processing circuity 42, a memory 44 and a communication interface 46. The processing circuitry 42 may be in communication with the memory 44 (e.g., a memory device) via a bus for passing information among components of the apparatus. The memory device 44 may be non-transitory and may include, for example, one or more volatile and/or non-volatile memories. In other words, for example, the memory device 44 may be an electronic storage device (e.g., a computer readable storage medium) comprising gates configured to store data (e.g., bits) that may be retrievable by a machine (e.g., a computing device like the processing circuitry 42). The memory device 44 may be configured to store information, data, content, applications, instructions, or the like for enabling the apparatus 40 to carry out various functions in accordance with an example embodiment of the present disclosure. For example, the memory device 44 could be configured to buffer input data for processing by the processing circuitry. Additionally or alternatively, the memory device 44 could be configured to store instructions for execution by the processing circuitry. The apparatus 40 may, in some embodiments, be embodied in various computing devices as described above. However, in some embodiments, the apparatus 40 may be embodied -I 2 -as a chip or chip set. In other words, the apparatus 40 may comprise one or more physical packages (e.g., chips) including materials, components and/or wires on a structural assembly (e.g., a baseboard). The structural assembly may provide physical strength, conservation of size, and/or limitation of electrical interaction for component circuitry included thereon. The apparatus 40 may therefore, in some cases, be configured to implement an embodiment of the present disclosure on a single chip or as a single "system on a chip." As such, in some cases, a chip or chipset may constitute means for performing one or more operations for providing the functionalities described herein.

[0056] The processing circuitry 42 may be embodied in a number of different ways. For example, the processing circuitry 42 may be embodied as one or more of various hardware processing means such as a coprocessor, a microprocessor, a controller, a digital signal processor (DSP), a processing element with or without an accompanying DSP, or various other circuitry including integrated circuits such as, for example, an ASIC (application specific integrated circuit), an FPGA (field programmable gate array), a microcontroller unit (MCU), a hardware accelerator, a special-purpose computer chip, or the like. As such, in some embodiments, the processing circuitry 42 may include one or more processing cores configured to perform independently. A multi-core processing circuitry may enable multiprocessing within a single physical package. Additionally, or alternatively, the processing circuitry 42 may include one or more processors configured in tandem via the bus to enable independent execution of instructions, pipelining and/or multithreading. In an example embodiment, the processing circuitry 42 may be configured to execute instructions stored in the memory device 44 or otherwise accessible to the processing circuitry. Alternatively, or additionally, the processing circuitry 42 may be configured to execute hard coded functionality. As such, whether configured by hardware or software methods, or by a combination thereof, the processing circuitry 42 may represent an entity (e.g., physically embodied in circuitry) capable of performing operations according to an embodiment of the present disclosure while configured accordingly. Thus, for example, when the processing circuitry 42 is embodied as an ASIC, FPGA or the like, the processing circuitry may be specifically configured hardware for conducting the operations described herein. Alternatively, as another example, when the processing circuitry 42 is embodied as an executor of instructions, the instructions may specifically configure the processor to perform the algorithms and/or operations described herein when the instructions are -13 -executed. However, in some cases, the processing circuitry 42 may be a processor of a specific device (e.g., an image or video processing system) configured to employ an embodiment of the present disclosure by further configuration of the processing circuitry 42 by instructions for performing the algorithms and/or operations described herein. The processing circuitry 42 may include, among other things, a clock, an arithmetic logic unit (ALU) and logic gates configured to support operation of the processing circuitry.

[0057] The communication interface 46 may be any means such as a device or circuitry embodied in either hardware or a combination of hardware and software that is configured to receive and/or transmit data, including media content in the form of video or image files, one or more audio tracks or the like. In this regard, the communication interface 46 may include, for example, an antenna (or multiple antennas) and supporting hardware and/or software for enabling communications with a wireless communication network. Additionally, or alternatively, the communication interface 46 may include the circuitry for interacting with the antenna(s) to cause transmission of signals via the antenna(s) or to handle receipt of signals received via the antenna(s). In some environments, the communication interface 46 may alternatively or also support wired communication. As such, for example, the communication interface 46 may include a communication modem and/or other hardware/software for supporting communication via cable, digital subscriber line (DSL), universal serial bus (USB) or other mechanisms. The apparatus 40 may be (or be included in) one or more types of devices, such as an access node (e.g., a base station), a 11E, and/or an IoT device.

[0058] In one example embodiment, a network entity/node may include the apparatus 40.

For example, the network entity/node may include one or more components (e.g., the processing circuity 42, the memory 44, the communication interface 46) configured to support one or more techniques for determining and exploiting spatial proximity between reference signals, as described herein. The network entity/node may be but is not limited to a base station, a gNB or a TRP. In another example embodiment, a UE may include the apparatus 40. For example, the UE may include one or more components (e.g., the processing circuity 42, the memory 44, the communication interface 46) configured to support one or more techniques for determining and exploiting spatial proximity between reference signals, as described herein.

[0059] A set of reference signals {RS1, , RS1,11 may be transmitted by a network entity (e.g., a base station, a gNB or TRP), within a serving cell of a ITE, in some examples, for intra- -14 -cell beam management. In some examples, it may be transmitted within a neighboring cell of the UE, in some examples, for inter-cell beam management and/or LTM. In s delink communication scenarios, for example, V2X and A2X, the set of reference signals {R,Si, , RSic} may be transmitted by another UE, for example, another vehicle.

[0060] The angular spacing among beams may be uniform (i.e., with a same angular step between any adjacent beams) or non-uniform, for example, in the elevation dimension, the spacing may be finer towards the horizon and coarser for high or low elevations.

[0061] The spatial relationship between a pair of reference signals (RSi, RSJ) may be in the form of a beam adjacency (au = {0, 1}) between their associated transmission beams (bi, b;), where adjacent beams may be understood to be contiguous in space (i.e., next to each other). As disclosed herein, in some examples, adjacent beams may partially overlap, but they do not fully overlap. In other words, there's at least some region of space covered (with sufficient beamforming gain) only by one of the beams and at least some region of space covered (with sufficient beamforming gain) only by the other beam. For example, in Figure 1, beam b2 (corresponding to reference signal RS2) is adjacent to beams bi and b3 (corresponding to reference signals RS1 and RS3, respectively), thus an = 1 and a23 = 1. Conversely, non-adjacent beams may be understood to be non-contiguous in space (i.e., not next to each other). For example, beams bi and b3 are non-adjacent, thus an = 0.

[0062] In some examples, the spatial relationship between a pair of reference signals (R,Si, RS]) may be in the form of a beam distance (du = {0, 1, 2, ... {) between their associated transmission beams (bi, bi). The case du = 0 applies when bi = bi (i.e., any beam is at zero distance to itself). Adjacent beams, as described above, may be considered to be at a distance of one (du = 1), for example, d12 = 1. Non-adjacent beams may be considered to be at a distance larger than one (du = 2, 3, ). For example, beams bi and b3 may be said to be 2 beams apart, i.e., d13 = 2.

[0063] In some examples, the beam distance may be in the form of an angular separation (Au E [0, 180] deg) between a first transmission direction (Oh pi) associated with the first beam (bi) and a second transmission direction (01, pi) associated with the second beam (b). The transmission direction associated with a beam may correspond to the direction of maximum or peak beamforming gain. For example, the set of reference signals {RS1, ..., RS8} in Error! Reference source not found. are transmitted on beams with transmission directions separated by steps of 10 deg. For instance, the angular separation between bi and b3 is An = 20 deg.

[0064] Referring now to Figure 5, some operations performed by the apparatus 40, for example by a UE, in order to determine and exploit spatial proximity between reference signals, in one example embodiment, are depicted.

100651 As shown in block 52 of Figure 5, the UE includes means (e.g., the processing circuitry 42, the memory device 44) for determining a spatial relationship between a pair of reference signals, comprising a first reference signal and a second reference signal, among a set of reference signals transmitted by a network entity or another UE, in an example, in the case of sidelink communication. The spatial relationship comprises a beam distance between a first beam associated with the first reference signal and a second beam associated with the second reference signal.

[0066] In some examples, the spatial relationship between a pair of reference signals (RS1, RS;) may be determined by the UE based on a time offset (At = t -ti) between their associated transmission resources (ti, t) (e.g., symbols, slots). In some examples, the UE may assume that RSs transmitted closer in time correspond to beams located closer in space. In some examples, consecutive RS transmissions in time may be assumed to be associated with adjacent beams in space. Referring to Error! Reference source not found., this would correspond to transmitting the set of reference signals sequentially in time (e.g., in contiguous symbols within a slot) in the order (RS1, RS2, , RS8) or (RS8, RSA, , RS1). In this case, the beam distance (du) may be determined based on the time offset (At). For example, in case the set of reference signals are transmitted in contiguous symbols Oh, siv), reference signals transmitted m symbols apart may be assumed to be transmitted on beams that are at a beam distance du = m beams.

[0067] In some examples, the time offset (At = t -ti) may further convey information about an order in azimuth and/or elevation between the first beam (b) and the second beam (b). For example, a negative time offset (At < 0) may indicate that the first beam (bi) has a lower azimuth (e.g., in a clockwise angular direction) and/or elevation than the second beam (b;), while a positive time offset (At > 0) may indicate that the first beam (bi) has a higher azimuth and/or elevation than the second beam (b).

[0068] In some examples, the network entity or the other UE may configure the UE for periodic beam reporting, with longer periodicities (i.e., less frequent reporting) for reporting distant beams (e.g., relative to the strongest beam) and shorter periodicities for reporting adjacent beams (i.e., more frequent reporting). Furthermore, in some examples, the UE may leverage such awareness to skip certain beam measurements or perform certain beam measurements less frequently, for example, on beams that are distant from the currently strongest beam, and are therefore likely to result in a weak received signal.

100691 In some examples, the spatial relationship between a pair of reference signals (RS, RSJ) may be determined by the UE based on a difference (An) between their associated identifiers. An identifier for a reference signal may include an SSB resource indicator (SSBRI), a CSI-RS resource indicator (CRT), a TCI state ID, etc. For example, the UE may assume that RSs with numerically closer identifiers correspond to beams located closer in space. In some examples, RSs with consecutive identifiers may be assumed to be associated with adjacent beams in space. In this case, the beam distance (di) may be determined based on the difference (An) between their identifiers, and independently from their associated transmission resources. For example, CRT and CRT may be assumed to be transmitted on beams that are at a beam distance du = CRT; -CRT.; beams.

[0070] In some examples, among reference signals {RSI, , RSN}, such as SSBs or CSI-RSs, transmitted by the network entity or another UE, the network entity or the other UE may indicate, either explicitly or implicitly, whether a pair of reference signals (RS;, RS;) are transmitted on adjacent beams (au = 1) or non-adjacent beams (aJJ = 0), or are transmitted on beams that are a certain beam distance (du = {0, I, 2, ... }) apart (in azimuth and/or elevation).

[0071] In some examples, the spatial relationship between a pair of reference signals (RS;, RSJ) may be determined by the UE based on received control information, for example, an indication by the network entity or the other apparatus. Such control information may include or indicate (e.g., using an efficient encoding) a beam adjacency matrix (aJJ = {0, 1}) indicating, for each pair of reference signals (RSA, RS) in the set of reference signals (RS1, , RSN), whether their associated beams (bi bj) are adjacent (au = 1) or non-adjacent (au = 0) in space.

[0072] Additional or alternatively, in some examples, the control information may include or indicate (e.g., using an efficient encoding) a beam distance matrix (du = {0, 1, 2, ... }) indicating, for each pair of reference signals (RSJ, RSJ) in the set of reference signals IRS1, RSNI, a beam distance between their associated beams (bi, b.). In one example, the beam distance (du) corresponding to a pair of reference signals (RS;, RS;) may be determined as a length of a shortest path between vertices (vi, yi) representing their associated beams (bi, Ili) in a graph (G). An example of such a graph (G) is illustrated in Figure 6, where each hexagon represents a subregion of angular space covered by a different transmission beam in azimuth and elevation, and the presence of an edge between two vertices indicates beam adjacency. In this case, each vertex in the graph, representing a particular transmission beam, has up to six (6) neighbor vertices, representing its adjacent transmission beams in a hexagonal tiling on a sphere. According to this example graph, the beam distance between RS, and RS12 is cli_12 = 4 beams, corresponding to the length of a shortest path between the associated vertices.

[0073] In some examples, such as when the spatial relationship among beams can be represented by a graph with a linear topology (or a ring topology), such as the example of Error! Reference source not found., beam adjacency may be efficiently indicated by means of a permutation index, indicating one out of all possible (N!) permutations (i.e., orderings) of the set of reference signals {RS,, RSNI, where N is the cardinality of the set. For example, the ordered sequence (CR15, CRI2, CR17, CRIB, CRIB, CRI4, CR16, CR11) (where consecutive entries correspond to CSI-RSs transmitted on adjacent beams) may be indicated by a certain permutation index, while the ordered sequence (CR18, CR13, CRI2, CR11, CR14, CRI7, CRI6, CRI5) may be indicated by a different permutation index. Such an encoding requires ceil( log2(N!) ) bits. This encoding may also be applied to more complex, non-linear topologies (such as that shown in Figure 6), by assuming a specific linear path across all vertices (e.g., see path of increasing RS indices along adjacent beams in Figure 6).

[0074] In some examples, the control information may include or indicate (e.g., using an efficient encoding) an angular separation matrix (Au e [0, n]) indicating, for each pair of reference signals (RSi, RS;) in the set of reference signals {RSi, RSNI, an angular separation between their associated transmission directions (0i, (pi) and (0i, (pj). In case of a uniform spacing among the beams, this may be efficiently indicated by the above permutation index, accompanied by an indication of the spacing (e.g., 10 deg).

[0075] In some examples, the UE may determine whether or not to use the spatial relationship among reference signals for measurement and/or reporting based on certain considerations or criteria. For example, the UE may use the spatial relationship only for certain reference signal types (e.g., CSI-RS) but not others (e.g., SSB). Similarly, the UE may use the spatial relationship for certain purposes (e.g., intra-cell beam management) but not others (e.g., -I 8 -inter-cell beam management, LTM). Tn some examples, the UE may use the spatial relationship when it determines a LOS channel condition relative to the reference signal transmitter (e.g., the network entity), but abstain from using it when it determines a NLOS channel condition.

[0076] In some examples, the network entity or the other TIE may explicitly enable/disable the use of the spatial relationship. For example, the network entity or the other UE may configure the UE to use the spatial relationship for a test period (e.g., a certain measurement duration, a number of samples, a number of measurement reports). During the test period, the UE may leverage its awareness of the spatial proximity or distance among reference signals when performing measurements and/or reporting. After the test period, the UE may report whether using the spatial relationship was suitable or desirable (e.g., in case of a LOS condition). For example, in NLOS conditions, the UE may determine that abstaining from measuring distant beams leads to a performance loss compared to performing all beam measurements (e.g., in an environment with rich scattering and/or strong reflectors). The network can then decide whether to enable or disable the use of the spatial relationship knowledge for future measurement and/or reporting.

[0077] Referring now to Figure 7, some operations performed at the apparatus 40, for example at a network entity or a TIE, for example, in the case of sidel ink communication, in order to determine and exploit spatial proximity between reference signals, in one example embodiment, are depicted.

[0078] As shown in block 72 of Figure 7, the apparatus 40 includes means (e.g., the processing circuitry 42, the communication interface 46) for transmitting control information to a UE, wherein the control information comprises or indicates at least one of: for each pair of reference signals in the set of reference signals, a beam distance between their associated beams, or a permutation index indicating an ordering of the set of reference signals, wherein consecutive entries correspond to signals associated with adjacent beams. The control information, the beam distance and permutation index may refer to the descriptions provided in the preceding paragraphs.

[0079] Referring now to Figure 8, some operations performed by the apparatus 40, for example by a UE, in order to determine and exploit spatial proximity between reference signals, in one example embodiment, are depicted.

-I 9 - [0080] As shown in block 82 of Figure 8, the UE includes means (e.g., the processing circuitry 42, the communication interface 46) for receiving, from a network entity or another UE, reporting configuration information indicating a first reporting periodicity for a first reference signal and a second reporting periodicity for a second reference signal, wherein a relative difference between the first reporting periodicity and the second reporting periodicity is based on a spatial relationship between the first reference signal and the second reference signal.

[0081] In block 84, the UE includes means (e.g., the processing circuitry 42, the communication interface 46) for reporting measurements on the first reference signal according to the first reporting periodicity and reporting measurements on the second reference signal according to the second reporting periodicity.

[0082] In some examples, the UE may receive reporting configuration information (e.g., CSI reporting configuration) for periodic or semi-persistent reporting of measurements on the set of reference signals {RS1, , RSN}, with different reporting periodicities for different reference signals based on their spatial relationship. In some examples, longer beam reporting periodicities may be configured for beams located further away from the currently strongest beam. For example, referring to Figure 1, the UE may be configured to report measurements on the currently strongest beam b2 as well as adjacent beams bi and b3 with a first reporting periodicity, and report measurements on non-adjacent beams b4, b5, etc. with a second reporting periodicity which is longer (i.e., less frequent reporting). This is motivated by the lower likelihood of the UE transitioning to a non-adjacent beam. The further a beam is from the currently strongest one, the longer the reporting periodicity may be configured. In some examples, the UE may be configured to abstain from reporting measurements on reference signals associated with beams that are further than a threshold (dth) relative to the strongest beam. For example, for currently strongest beam b2 and a threshold dth = 3, the UE may be configured to skip reporting measurements on RS6, RS7, RSs.

[0083] Referring now to Figure 9, some operations performed at the apparatus 40, for example at a network entity or a UE, for example, in the case of sidelink communication, in order to determine and exploit spatial proximity between reference signals, in one example embodiment, are depicted.

[0084] As shown in block 92 of Figure 9, the apparatus 40 includes means (e.g., the processing circuitry 42, the communication interface 46) for transmitting reporting configuration -20 -information indicating a first reporting periodicity for a first reference signal and a second reporting periodicity for a second reference signal, wherein a relative difference between the first reporting periodicity and the second reporting periodicity is based on a spatial relationship between the first reference signal and the second reference signal.

[0085] In block 94, the apparatus 40 includes means (e.g., the processing circuitry 42, the communication interface 46) for receiving measurements on the first reference signal according to the first reporting periodicity and receiving measurements on the second reference signal according to the second reporting periodicity.

[0086] Referring now to Figure 10, some operations performed by the apparatus 40, for example by a UE, in order to determine and exploit spatial proximity between reference signals, in one example embodiment, are depicted.

[0087] As shown in block 102 of Figure 10, the UE includes means (e.g., the processing circuitry 42, the communication interface 46) for receiving, from a network entity or another UE, event configuration information indicating one or more of: at least one first event condition for triggering measurement and/or reporting associated with at least one adjacent beam, or at least one second event condition for triggering measurement and/or reporting associated with at least one beam within a certain beam distance.

[0088] In some examples, the UE may receive event configuration information indicating one or more event conditions for triggering measurement and/or reporting associated with an adjacent beam, e.g., based on a received signal strength on a reference beam crossing a threshold.

For example, the UE may be configured to trigger measurements on reference signals associated with on one or more beams adjacent to the currently strongest beam when the RSRP of the strongest beam becomes weaker than the threshold. In some other examples, the event configuration information may indicate one or more event conditions for triggering measurement and/or reporting associated with beams that are within a certain beam distance (e.g., 2 hops away) or angular separation (e.g., 30 deg) relative to the reference beam.

[0089] Referring now to Figure I I, some operations performed at the apparatus 40, for example at a network entity or a DE, for example, in the case of sidelink communication, in order to determine and exploit spatial proximity between reference signals, in one example embodiment, are depicted.

-21 - [0090] As shown in block 112 of Figure II, the apparatus 40 includes means (e.g., the processing circuitry 42, the communication interface 46) for transmitting to a UE event configuration information indicating one or more of: at least one first event condition for triggering measurement and/or reporting associated with at least one adjacent beam, or at least one second event condition for triggering measurement and/or reporting associated with at least one beam within a certain beam distance.

[0091] In some examples, the TIE may leverage its enhanced awareness regarding the spatial relationship among reference signals to skip certain beam measurements which are likely to be weak, or perform certain beam measurements less frequently.

[0092] For example, referring to Figure 1, the UE may have determined RS2 as the strongest reference signal after performing measurements on the entire set of reference signals {RS1, , RS8}. Based on its knowledge about the beam distance or angular separation among the associated beams, the UE may decide whether or not to perform measurements on distant beams. For example, the UE may decide to skip measurements on beams b6, b7, b8, while continuing to measure all other beams bi, b2, b3, b4, b5.

[0093] In some examples, the number of beams that are skipped may depend on the measurements on the strongest beam (e.g., RSRP2) and/or adjacent beams (e.g., RSRPI, RSRP3). For example, the UE may use a stopping criterion whereby a beam measurement below a threshold causes the UE to abstain from measuring beams even further away. Such threshold may also depend on the strongest beam measurement (e.g., RSRP2). For example, if RSRP2 is very strong, the UE may stop sooner, e.g., only perform measurements on adjacent and/or near-adjacent beams.

[0094] In some examples, such decisions may be further based on whether the UE is experiencing a LOS or NLOS channel relative to the transmitter of the reference signals (e.g. a TRP). In NLOS scenarios, and especially in an environment with rich scattering and/or many strong reflectors (e.g., a factory floor), the UE may decide to continue measuring the entire set of reference signals IRSI, , RS81, as there may be distant beams with an unexpectedly strong received signal (e.g., as a result of a strong reflection).

[0095] The stopping or skipping of beam measurements may also be based on a threshold.

For example, a beam distance threshold (dth) and/or an angular separation threshold (All). In such cases, the UE may perform measurements on beams whose beam distance, relative to the -22 -currently strongest beam, is below the beam distance threshold (dth), or whose angular separation with respect to the transmission direction of the currently strongest reference signal is below the angular separation threshold (Ad,). For example, the UE may abstain from performing measurements on reference signals transmitted beyond 30 deg of the currently strongest reference signal.

100961 In some other examples, rather than skipping certain beam measurements, the UE may perform them less frequently. For example, the measurement periodicity (NO of a reference signal (RSJ) may depend on its spatial relationship relative to the strongest beam. The UE may measure distant beams less frequently, while measuring closer beams more frequently.

[0097] Without in any way limiting the scope, interpretation, or application of the claims appearing below, a technical effect of one or more of the example embodiments disclosed herein may include enhancement of a UE's awareness about the spatial relationship among reference signals transmitted by network entity or another UE. The UE may skip or perform less frequently certain measurements which are likely to be weak (e.g., corresponding to beams which point far away from the direction of the LIE, as seen from the network). In addition, the network entity may configure longer reporting periodicities (i.e., less frequent reporting) for distant beams relative to the currently strongest beam and/or shorter reporting periodicities (i.e., more frequent reporting) for adjacent beams. The benefit for doing this is more timely beam report and yet with reduced reporting overhead, which may provide energy savings, latency reduction and lower UE complexity.

[0098] The subject matter described herein may be embodied in systems, apparatus, methods, and/or articles depending on the desired configuration. For example, the base stations and user equipment (or one or more components therein) and/or the processes described herein can be implemented using one or more of the following: a processor executing program code, an application-specific integrated circuit (ASIC), a digital signal processor (DSP), an embedded processor, a field programmable gate array (FPGA), and/or combinations thereof These various implementations may include implementation in one or more computer programs that are executable and/or interpretable on a programmable system including at least one programmable processor, which may be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device. These computer programs (also known as programs, software, software -23 -applications, applications, components, program code, or code) include machine instructions for a programmable processor, and may be implemented in a high-level procedural and/or object-oriented programming language, and/or in assembly/machine language. As used herein, the term "computer-readable medium" refers to any computer program product, machine-readable medium, computer-readable storage medium, apparatus and/or device (for example, magnetic discs, optical disks, memory, Programmable Logic Devices (PLDs)) used to provide machine instructions and/or data to a programmable processor, including a machine-readable medium that receives machine instructions. Similarly, systems are also described herein that may include a processor and a memory coupled to the processor. The memory may include one or more programs that cause the processor to perform one or more of the operations described herein.

[0099] If desired, the different functions discussed herein may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the above-described functions may be optional or may be combined.

[001001 Although various aspects of the invention are set out in the independent claims, other aspects of the invention comprise other combinations of features from the described embodiments and/or the dependent claims with the features of the independent claims, and not solely the combinations explicitly set out in the claims.

[001011 It is also noted herein that while the above describes example embodiments of the invention, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope of the present invention as defined in the appended claims. Other embodiments may be within the scope of the following claims. The term "based on" includes "based at least in part on". The use of the phase "such as" means "such as for example" unless otherwise indicated.

-24 -

Claims (25)

1. CLAIMSWhat is claimed is: 1. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive reporting configuration information indicating: i. a first reporting periodicity for a first reference signal, and ii. a second reporting periodicity for a second reference signal, wherein a relative difference between the first reporting periodicity and the second reporting periodicity is based on a spatial relationship between the first reference signal and the second reference signal; and report measurements on the first reference signal according to the first reporting periodicity and report measurements on the second reference signal according to the second reporting periodicity.
2. 2. The apparatus according to claim 1, wherein the spatial relationship comprises: a beam distance between a first beam associated with the first reference signal and a second beam associated with the second reference signal.
3. 3. The apparatus according to claim 2, wherein the beam distance between the first beam and the second beam is based on an angular separation between a first transmission direction associated with the first beam and a second transmission direction associated with the 25 second beam.
4. 4. The apparatus according to claim 2 or 3, wherein the relative difference between the first reporting periodicity and the second reporting periodicity increases with the beam distance.
5. -25 - 5. The apparatus according to any of claims I -4, wherein the apparatus is further caused to: abstain from reporting measurements on reference signals associated with beams that are further than a threshold relative to a strongest beam.
6. 6. The apparatus according to any of claims 1-5, wherein the apparatus is further caused to: determine to use the spatial relationship for a test period, and report whether using the spatial relationship is suitable or desirable based on a relative performance observed during the test period.
7. 7. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive event configuration information indicating one or more of: i. at least one first event condition for triggering measurement and/or reporting associated with at least one adjacent beam, or ii. at least one second event condition for triggering measurement and/or reporting associated with at least one beam within a certain beam distance.
8. 8. The apparatus according to claim 7, wherein based on the received event configuration information, the apparatus is further caused to perform at least one of: perform and/or report measurements on reference signals associated with one or more 25 beams adjacent to a strongest beam when a received signal strength of the strongest beam becomes weaker than a threshold, or perform and/or report measurements on reference signals associated with one or more beams within a beam distance relative to a reference beam when a received signal strength of the reference beam becomes weaker than a threshold.
9. -26 - 9. The apparatus according to claim 8, wherein a beam distance between a first beam and a second beam is determined based on an angular separation between a first transmission direction associated with the first beam and a second transmission direction associated with the second beam.
10. 10. The apparatus according to any of claims 1-9, wherein the apparatus is or s comprised in a user equipment.
11. 11. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: transmit, to a user equipment, reporting configuration information indicating: i. a first reporting periodicity for a first reference signal and ii. a second reporting periodicity for a second reference signal, wherein a relative difference between the first reporting periodicity and the second reporting periodicity is based on a spatial relationship between the first reference signal and the second reference signal, receive measurements on the first reference signal according to the first reporting periodicity and receive measurements on the second reference signal according to the second reporting periodicity.
12. 12. The apparatus according to claim 11, wherein the spatial relationship comprises: a beam distance between a first beam associated with the first reference signal and a second beam associated with the second reference signal.
13. 13. The apparatus according to claim 12, wherein the beam distance between the first beam and the second beam is based on an angular separation between a first transmission direction associated with the first beam and a second transmission direction associated with the 30 second beam.
14. -27 - 14. The apparatus according to claim 12 or 13, wherein the relative difference between the first reporting periodicity and the second reporting periodicity increases with the beam distance.
15. 15. '1' he apparatus according to any of claims 11-14, wherein the apparatus is further caused to: configure the user equipment to use the spatial relationship for a test period; receive a report from the user equipment on whether using the spatial relationship is suitable or desirable based on a relative performance observed during the test period; and determine whether to enable or disable the use of the spatial relationship for measurement and/or reporting based on the report.
16. 16. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: transmit, to a user equipment, event configuration information indicating one or more of: i. at least one first event condition for triggering measurement and/or reporting associated with at least one adjacent beam, or at least one second event condition for triggering measurement and/or reporting associated with at least one beam within a certain beam distance.
17. 17. The apparatus according to any of claims 11-16, wherein the apparatus is or is comprised in a network entity.
18. 18. The apparatus according to any of claims I 1-16, wherein the apparatus is or is comprised in another user equipment.
19. 19. An apparatus comprising: means for receiving reporting configuration information indicating: -28 -i. a first reporting periodicity for a first reference signal, and ii. a second reporting periodicity for a second reference signal, wherein a relative difference between the first reporting periodicity and the second reporting periodicity is based on a spatial relationship between the first reference signal and the second reference signal; and means for reporting measurements on the first reference signal according to the first reporting periodicity and means for reporting measurements on the second reference signal according to the second reporting periodicity.
20. 20. An apparatus comprising: means for receiving event configuration information indicating one or more of i. at least one first event condition for triggering measurement and/or reporting associated with at least one adjacent beam, or at least one second event condition for triggering measurement and/or reporting associated with at least one beam within a certain beam distance.
21. 21. An apparatus comprising: means for transmitting, to a user equipment, reporting configuration information indicating: i. a first reporting periodicity for a first reference signal and a second reporting periodicity for a second reference signal, wherein a relative difference between the first reporting periodicity and the second reporting periodicity is based on a spatial relationship between the first reference signal and the second reference signal, means for receiving measurements on the first reference signal according to the first reporting periodicity and means for receiving measurements on the second reference signal according to the second reporting periodicity.
22. 22. An apparatus comprising: :30 means for transmitting, to a user equipment, event configuration information indicating one or more of -29 -i. at least one first event condition for triggering measurement and/or reporting associated with at least one adjacent beam, or ii. at least one second event condition for triggering measurement and/or reporting associated with at least one beam within a certain beam distance. 5
23. 23. A method comprising: receiving reporting configuration information indicating: i. a first reporting periodicity for a first reference signal, and a second reporting periodicity for a second reference signal, wherein a relative difference between the first reporting periodicity and the second reporting periodicity is based on a spatial relationship between the first reference signal and the second reference signal, reporting measurements on the first reference signal according to the first reporting periodicity and reporting measurements on the second reference signal according to the second reporting periodicity.
24. 24. A method comprising: receiving event configuration information indicating one or more of: i. at least one first event condition for triggering measurement and/or reporting associated with at least one adjacent beam, or at least one second event condition for triggering measurement and/or reporting associated with at least one beam within a certain beam distance.
25. 25. A method comprising: transmitting, to a user equipment, reporting configuration information indicating: i. a first reporting periodicity for a first reference signal and a second reporting periodicity for a second reference signal, wherein a relative difference between the first reporting periodicity and the second reporting periodicity is based on a spatial relationship between the first reference signal and the second reference signal, receiving measurements on the first reference signal according to the first reporting periodicity and receiving measurements on the second reference signal according to the second reporting periodicity.