Method and apparatus for lower-layer triggered mobility (LTM) measurement reporting

Abstract

Methods, apparatuses, and systems provide MAC CE formats for LTM measurement reporting. In the context of a method, the method includes identifying an occurrence of an event associated with LTM reporting for one or more candidate cells based at least in part on one or more measurements associated with the one or more candidate cells; receiving control information indicative of an uplink grant for the LTM reporting; determining that a size of the uplink grant fails to accommodate an LTM report for the event; and transmitting a MAC CE indicating a portion of the LTM report based at least in part on the determination, wherein the portion of the LTM report includes a quantity of measurement values associated with the one or more measurements, and wherein the quantity of measurement values is based at least in part on the size of the uplink grant.

Description

METHOD AND APPARATUS FOR LOWER-LAYER TRIGGERED MOBILITY (LTM)MEASUREMENT REPORTINGTECHNOLOGICAL FIELD

[0001] The present disclosure relates generally to techniques for lower-layer triggered mobility (LTM) measurement reporting and, more particularly, to medium access control (MAC) control element (CE) formats for LTM measurement reporting.BACKGROUND

[0002] In 5G New Radio, beam management is used for maintaining reliable communication within a network. A user equipment (UE) may be configured to support one or more beam management procedures, such as lower-layer triggered mobility (LTM) measurement reporting, to improve beam selection for communications with one or more network nodes. In accordance with a beam management procedure, the UE may perform measurements to assess a quality of one or more beams used for communications with the one or more network nodes. The UE may report information pertaining to the quality of the beam(s) to a network node, which may use the reported information for beam selection. Improvements in how a UE reports, to the network, information associated with beam management procedures are needed.BRIEF SUMMARY

[0003] Methods, apparatuses, and systems are disclosed for LTM measurement reporting. In this regard, the methods, apparatuses, and systems are configured to support MAC CE formats for LTM measurement reporting so as to provide for increased flexibility for resource management and more efficient traffic prioritization for user equipment (UE) triggered reporting. By providing for increased flexibility for resource management and more efficient traffic prioritization, the methods, apparatuses, and systems may provide for reduced latency and improved performance of wireless communications in a network.

[0004] In at least one example embodiment, an apparatus is provided comprising at least one processor and at least one memory including computer program code (e.g., instructions) configured to, with the at least one processor, cause the apparatus at least to identify an occurrence of an event associated with lower-layer triggered mobility (LTM) reporting for one ormore candidate cells based at least in part on one or more measurements associated with the one or more candidate cells; receive control information indicative of an uplink grant for the LTM reporting; determine that a size of the uplink grant fails to accommodate an LTM report for the event; and transmit a medium access control (MAC) control element (CE) indicating a portion of the LTM report based at least in part on the determination, wherein the portion of the LTM report includes a quantity of measurement values associated with the one or more measurements, and wherein the quantity of measurement values is based at least in part on the size of the uplink grant.

[0005] In at least one example embodiment, the portion of the LTM report is encoded in the MAC CE in accordance with a truncated MAC CE format, and wherein the MAC CE includes an indication of the truncated MAC CE format.

[0006] In at least one example embodiment, based at least in part on the size of the uplink grant, the quantity of measurement values includes at least one measurement value.

[0007] In at least one example embodiment, the portion of the LTM report includes a set of reference signal identifier and measurement value pairs for each of the one or more candidate cells, and wherein a reference signal identifier and measurement value pair of the set of reference signal identifier and measurement value pairs includes the at least one measurement value.

[0008] In at least one example embodiment, a quantity of reference signal identifier and measurement value pairs included in the set of reference signal identifier and measurement value pairs is based at least in part on a threshold.

[0009] In at least one example embodiment, based at least in part on the size of the uplink grant, the quantity of measurement values includes zero measurement values.

[0010] In at least one example embodiment, the quantity of measurement values includes zero measurement values based at least in part on the portion of the LTM report including zero reference signal identifier and measurement value pairs.

[0011] In at least one example embodiment, the MAC CE omits a measurement value of a reference signal identifier and measurement value pair based at least in part on the size of the uplink grant failing to accommodate the reference signal identifier and measurement value pair.

[0012] In at least one example embodiment, the measurement value is associated with an octet of the MAC CE, and wherein the octet follows at least one other octet of the MAC CE carrying at least one reference signal identifier and measurement value pair.

[0013] In at least one example embodiment, the portion of the LTM report includes one or more reference signal identifiers for at least one candidate cell of the one or more candidate cells, and wherein the quantity of measurement values is based at least in part on one or more measurement values associated with the one or more reference signal identifiers being omitted from the MAC CE.

[0014] In at least one example embodiment, the one or more reference signal identifiers are included in one or more consecutive octets of the MAC CE.

[0015] In at least one example embodiment, the one or more measurement values are associated with one or more consecutive octets of the MAC CE.

[0016] In at least one example embodiment, the portion of the LTM report includes a set of reference signal identifiers for at least one candidate cell of the one or more candidate cells, and wherein the quantity of measurement values includes a set of measurement values associated with one or more reference signal identifiers of the set of reference signal identifiers.

[0017] In at least one example embodiment, the set of reference signal identifiers are included in a first set of one or more consecutive octets of the portion of the MAC CE and the set of measurement values are included in a second set of one or more consecutive octets of the portion of the MAC CE following the first set of one or more consecutive octets.

[0018] In at least one example embodiment, an order of measurement values within the second set of one or more consecutive octets is based at least in part on an order of reference signal identifiers within the first set of one or more consecutive octets.

[0019] In at least one example embodiment, the portion of the LTM report includes one or more reference signal identifiers for at least one candidate cell of the one or more candidate cells, and wherein the quantity of measurement values includes a measurement value associated with a reference signal identifier of the one or more reference signal identifiers.

[0020] In at least one example embodiment, the portion of the LTM report includes the measurement value based at least in part on a position, within the portion of the MAC CE, of the reference signal identifier relative to at least one other reference signal identifier of the one or more reference signal identifiers.

[0021] In at least one example embodiment, the portion of the LTM report includes the measurement value based at least in part on the measurement value being greater than one ormore other measurement values associated with one or more other reference signal identifiers of the one or more reference signal identifiers.

[0022] In at least one example embodiment, the portion of the LTM report includes, for each candidate cell of the one or more candidate cells, a set of reference signal identifiers and a set of measurement values associated with one or more reference signal identifiers of the set of reference signal identifiers, wherein the quantity of measurement values includes the set of measurement values, and wherein the quantity of measurement values is based at least in part on a threshold.

[0023] In at least one example embodiment, a respective value of each reference signal identifier of the one or more reference signal identifiers is lower than one or more values of one or more other reference signal identifiers in the set of reference signal identifiers.

[0024] In at least one example embodiment, the MAC CE omits information pertaining to a serving cell associated with the apparatus based at least in part on the size of the uplink grant.

[0025] In at least one example embodiment, the MAC CE includes an indication that the LTM report includes a portion of information to be reported for the event.

[0026] In at least one example embodiment, the MAC CE includes an indication that the event is pending.

[0027] In at least one example embodiment, transmitting the portion of the LTM report via the MAC CE indicates that the event is pending.

[0028] In at least one example embodiment, the at least one memory and the instructions, when executed by the at least one processor, cause the apparatus to transmit a request for additional uplink resources based at least in part on the determination.

[0029] In at least one example embodiment, an apparatus is provided comprising at least one processor and at least one memory including computer program code (e.g., instructions) configured to, with the at least one processor, cause the apparatus at least to transmit control information indicative of an uplink grant for lower-layer triggered mobility (LTM) reporting associated with an event for one or more candidate cells based at least in part on one or more measurements associated with the one or more candidate cells; and receive a medium access control (MAC) control element (CE) indicating a portion of an LTM report for the event based at least in part on a size of the uplink grant failing to accommodate the LTM report, wherein the portion of the LTM report includes a quantity of measurement values associated with the one ormore measurements, and wherein the quantity of measurement values is based at least in part on the size of the uplink grant.

[0030] In at least one example embodiment, the portion of the LTM report is encoded in the MAC CE in accordance with a truncated MAC CE format, and wherein the MAC CE includes an indication of the truncated MAC CE format.

[0031] In at least one example embodiment, based at least in part on the size of the uplink grant, the quantity of measurement values includes at least one measurement value.

[0032] In at least one example embodiment, the portion of the LTM report includes a set of reference signal identifier and measurement value pairs for each of the one or more candidate cells, and wherein a reference signal identifier and measurement value pair of the set of reference signal identifier and measurement value pairs includes the at least one measurement value.

[0033] In at least one example embodiment, a quantity of reference signal identifier and measurement value pairs included in the set of reference signal identifier and measurement value pairs is based at least in part on a threshold.

[0034] In at least one example embodiment, based at least in part on the size of the uplink grant, the quantity of measurement values includes zero measurement values.

[0035] In at least one example embodiment, the quantity of measurement values includes zero measurement values based at least in part on the portion of the LTM report including zero reference signal identifier and measurement value pairs.

[0036] In at least one example embodiment, the MAC CE omits a measurement value of a reference signal identifier and measurement value pair based at least in part on the size of the uplink grant failing to accommodate the reference signal identifier and measurement value pair.

[0037] In at least one example embodiment, the measurement value is associated with an octet of the MAC CE, and wherein the octet follows at least one other octet of the MAC CE carrying at least one reference signal identifier and measurement value pair.

[0038] In at least one example embodiment, the portion of the LTM report includes one or more reference signal identifiers for at least one candidate cell of the one or more candidate cells, and wherein the quantity of measurement values is based at least in part on one or more measurement values associated with the one or more reference signal identifiers being omitted from the MAC CE.

[0039] In at least one example embodiment, the one or more reference signal identifiers are included in one or more consecutive octets of the MAC CE.

[0040] In at least one example embodiment, the one or more measurement values are associated with one or more consecutive octets of the MAC CE.

[0041] In at least one example embodiment, the portion of the LTM report includes a set of reference signal identifiers for at least one candidate cell of the one or more candidate cells, and wherein the quantity of measurement values includes a set of measurement values associated with one or more reference signal identifiers of the set of reference signal identifiers.

[0042] In at least one example embodiment, the set of reference signal identifiers are included in a first set of one or more consecutive octets of the portion of the MAC CE and the set of measurement values are included in a second set of one or more consecutive octets of the portion of the MAC CE following the first set of one or more consecutive octets.

[0043] In at least one example embodiment, an order of measurement values within the second set of one or more consecutive octets is based at least in part on an order of reference signal identifiers within the first set of one or more consecutive octets.

[0044] In at least one example embodiment, the portion of the LTM report includes one or more reference signal identifiers for at least one candidate cell of the one or more candidate cells, and wherein the quantity of measurement values includes a measurement value associated with a reference signal identifier of the one or more reference signal identifiers.

[0045] In at least one example embodiment, the portion of the LTM report includes the measurement value based at least in part on a position, within the portion of the MAC CE, of the reference signal identifier relative to at least one other reference signal identifier of the one or more reference signal identifiers.

[0046] In at least one example embodiment, the portion of the LTM report includes the measurement value based at least in part on the measurement value being greater than one or more other measurement values associated with one or more other reference signal identifiers of the one or more reference signal identifiers.

[0047] In at least one example embodiment, the portion of the LTM report includes, for each candidate cell of the one or more candidate cells, a set of reference signal identifiers and a set of measurement values associated with one or more reference signal identifiers of the set of reference signal identifiers, wherein the quantity of measurement values includes the set ofmeasurement values, and wherein the quantity of measurement values is based at least in part on a threshold.

[0048] In at least one example embodiment, a respective value of each reference signal identifier of the one or more reference signal identifiers is lower than one or more values of one or more other reference signal identifiers in the set of reference signal identifiers.

[0049] In at least one example embodiment, the MAC CE omits information pertaining to a serving cell associated with the apparatus based at least in part on the size of the uplink grant.

[0050] In at least one example embodiment, the MAC CE includes an indication that the LTM report includes a portion of information to be reported for the event.

[0051] In at least one example embodiment, the MAC CE includes an indication that the event is pending.

[0052] In at least one example embodiment, transmitting the portion of the LTM report via the MAC CE indicates that the event is pending.

[0053] In at least one example embodiment, the at least one memory and the instructions, when executed by the at least one processor, cause the apparatus to receive a request for additional uplink resources based at least in part on the determination.

[0054] In at least one example embodiment, a method is provided comprising identifying an occurrence of an event associated with lower-layer triggered mobility (LTM) reporting for one or more candidate cells based at least in part on one or more measurements associated with the one or more candidate cells; receiving control information indicative of an uplink grant for the LTM reporting; determining that a size of the uplink grant fails to accommodate an LTM report for the event; and transmitting a medium access control (MAC) control element (CE) indicating a portion of the LTM report based at least in part on the determination, wherein the portion of the LTM report includes a quantity of measurement values associated with the one or more measurements, and wherein the quantity of measurement values is based at least in part on the size of the uplink grant.

[0055] In at least one example embodiment, a method is provided comprising transmitting control information indicative of an uplink grant for lower-layer triggered mobility (LTM) reporting associated with an event for one or more candidate cells based at least in part on one or more measurements associated with the one or more candidate cells; and receiving a medium access control (MAC) control element (CE) indicating a portion of an LTM report for the eventbased at least in part on a size of the uplink grant failing to accommodate the LTM report, wherein the portion of the LTM report includes a quantity of measurement values associated with the one or more measurements, and wherein the quantity of measurement values is based at least in part on the size of the uplink grant.

[0056] In at least one example embodiment, a non-transitory computer readable storage medium is provided. The non-transitory computer readable storage medium comprises computer instructions that, when executed by an apparatus, cause the apparatus to identify an occurrence of an event associated with lower-layer triggered mobility (LTM) reporting for one or more candidate cells based at least in part on one or more measurements associated with the one or more candidate cells; receive control information indicative of an uplink grant for the LTM reporting; determine that a size of the uplink grant fails to accommodate an LTM report for the event; and transmit a medium access control (MAC) control element (CE) indicating a portion of the LTM report based at least in part on the determination, wherein the portion of the LTM report includes a quantity of measurement values associated with the one or more measurements, and wherein the quantity of measurement values is based at least in part on the size of the uplink grant.

[0057] In at least one example embodiment, a non-transitory computer readable storage medium is provided. The non-transitory computer readable storage medium comprises computer instructions that, when executed by an apparatus, cause the apparatus to transmit control information indicative of an uplink grant for lower-layer triggered mobility (LTM) reporting associated with an event for one or more candidate cells based at least in part on one or more measurements associated with the one or more candidate cells; and receive a medium access control (MAC) control element (CE) indicating a portion of an LTM report for the event based at least in part on a size of the uplink grant failing to accommodate the LTM report, wherein the portion of the LTM report includes a quantity of measurement values associated with the one or more measurements, and wherein the quantity of measurement values is based at least in part on the size of the uplink grant.

[0058] In at least one example embodiment, an apparatus is provided that comprises means for identifying an occurrence of an event associated with lower-layer triggered mobility (LTM) reporting for one or more candidate cells based at least in part on one or more measurements associated with the one or more candidate cells; receiving control information indicative of anuplink grant for the LTM reporting; determining that a size of the uplink grant fails to accommodate an LTM report for the event; and transmitting a medium access control (MAC) control element (CE) indicating a portion of the LTM report based at least in part on the determination, wherein the portion of the LTM report includes a quantity of measurement values associated with the one or more measurements, and wherein the quantity of measurement values is based at least in part on the size of the uplink grant.

[0059] In at least one example embodiment, an apparatus is provided that comprises means for transmitting control information indicative of an uplink grant for lower-layer triggered mobility (LTM) reporting associated with an event for one or more candidate cells based at least in part on one or more measurements associated with the one or more candidate cells; and receiving a medium access control (MAC) control element (CE) indicating a portion of an LTM report for the event based at least in part on a size of the uplink grant failing to accommodate the LTM report, wherein the portion of the LTM report includes a quantity of measurement values associated with the one or more measurements, and wherein the quantity of measurement values is based at least in part on the size of the uplink grant.

[0060] The above summary is provided merely for purposes of summarizing at least some example embodiments to provide a basic understanding of some aspects of the disclosure. Accordingly, it will be appreciated that the above-described embodiments are merely examples and should not be construed to narrow the scope or spirit of the disclosure in any way. It will also be appreciated that the scope of the disclosure encompasses many potential embodiments in addition to those summarized here, some of which will be further described below.BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Having thus described certain example embodiments of the present disclosure in general terms, reference will hereinafter be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

[0062] FIG. 1 illustrates an example of a communication network to which one or more examples disclosed herein may be applied;

[0063] FIG. 2 illustrates an example signaling diagram for LTM to which one or more examples disclosed herein may be applied;

[0064] FIG. 3 illustrates an example diagram of an LTM configuration to which one or more examples disclosed herein may be applied;

[0065] FIG. 4 illustrates an example diagram of components of an LTM configuration to which one or more examples disclosed herein may be applied;

[0066] FIG. 5 A and FIG. 5B illustrate examples of MAC subheaders to which one or more examples disclosed herein may be applied;

[0067] FIG. 6A and FIG. 6B illustrated examples of an octet of a MAC CE format to which one or more examples disclosed herein may be applied;

[0068] FIG. 7 illustrates an example diagram of encoded candidate cell information in a MAC CE format to which one or more examples disclosed herein may be applied;

[0069] FIG. 8 illustrates an example of a MAC CE format to which one or more examples disclosed herein may be applied;

[0070] FIG. 9 illustrates an example of octets in a MAC CE format to which one or more examples disclosed herein may be applied;

[0071] FIG. 10 illustrates an example of octets in a MAC CE format to which one or more examples disclosed herein may be applied;

[0072] FIG. 11 illustrates an example of octets in a MAC CE format to which one or more examples disclosed herein may be applied;

[0073] FIG. 12 illustrates an example of an octet in a MAC CE format to which one or more examples disclosed herein may be applied;

[0074] FIG. 13 illustrates an example diagram of encoded candidate cell in-formation in a multi-cell MAC CE format to which one or more examples dis-closed herein may be applied;

[0075] FIG. 14 illustrates an example diagram of encoded candidate cell in-formation in a single-cell MAC CE format to which one or more examples dis-closed herein may be applied;

[0076] FIG. 15 illustrates an example of an octet in a MAC CE format to which one or more examples disclosed herein may be applied;

[0077] FIG. 16 illustrates an example signaling diagram for LTM to which one or more examples disclosed herein may be applied;

[0078] FIG. 17A and FIG. 17B illustrate examples of octets in a MAC CE format to which one or more examples disclosed herein may be applied;

[0079] FIG. 18A and FIG. 18B illustrate examples of octets in a MAC CE format to which one or more examples disclosed herein may be applied;

[0080] FIG. 19 illustrates an example signaling diagram for LTM to which one or more examples disclosed herein may be applied;

[0081] FIG. 20 illustrates an example flowchart of a method to which one or more examples disclosed herein may be applied;

[0082] FIG. 21 illustrates an example flowchart of a method to which one or more examples disclosed herein may be applied; and

[0083] FIG. 22 illustrates an example block diagram of an apparatus to which one or more examples disclosed herein may be applied.DETAILED DESCRIPTION

[0084] The following embodiments are exemplary. Although the specification may refer to “an”, “one”, or “some” embodiment(s) in several locations of the text, this does not necessarily mean that each reference is made to the same embodiment(s), or that a particular feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments. Further, when a particular feature, structure, or characteristic is described in connection of an embodiment, it is within the knowledge of one skilled in the art to apply such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. It shall be understood that although the terms “first,” “second” and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another.

[0085] For the purposes of the present disclosure, the phrases “at least one of A or B”, “at least one of A and B”, and “A and / or B” means (A), (B), or (A and B). For the purposes of the present disclosure, the phrase “A, B, and / or C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C).

[0086] Embodiments described may be implemented in a communication network, such as any of the following radio access technologies (RATs): Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile communications (GSM, 2G), GSM EDGE radio access Network (GERAN), General Packet Radio Service (GRPS), Universal Mobile Telecommunication System (UMTS, 3G) based on basic wideband-code division multiple access (W-CDMA), high-speed packet access (HSPA), Long Term Evolution (LTE), LTE-Advanced, and enhanced LTE (eLTE), 5G (also called NR), or any future RAT such as 6G. Moreover, communication within the communication network may utilize any proper wirelesscommunication technology, comprising but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiple (OFDM), and / or Discrete Fourier Transform spread OFDM (DFT-s-OFDM).

[0087] As used herein, the term “network device” or “network node” refers to a node in a communication network via which user equipment may access the network and / or which is capable of controlling radio communication and managing radio resources within a cell. The network node or network device may be referred to as a base station (BS), an access point (AP) or an access node. The network device may be, depending on the applied technology, for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio head (RH), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low power node, a nonterrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, or an aircraft network device.

[0088] Moreover, in reference to a split radio access network (RAN), the network device may refer to a centralized unit (CU) of a base station and / or a distributed unit (DU) of a base station. An interface between CU and DU may be referred to as an Fl interface in NR. In the split RAN architecture, node operations may be carried out, at least partly, in the central / centralized unit, CU, (e.g. server, host or node) operationally coupled to the DU, (e.g. a radio head / node). One CU may control one or more DUs, acting at least as transmit / receive (Tx / Rx) nodes. In at least some embodiments, the DUs may comprise e.g. a radio link control (RLC), medium access control (MAC) layer and a physical (PHY) layer, whereas the CU may comprise the layers above RLC layer, such as a packet data convergence protocol (PDCP) layer, a radio resource control (RRC) layer and an internet protocol (IP) layer. Other functional splits are possible too. In practice, any processing task may be performed in either the CU or the DU and the boundary where the responsibility is shifted between the CU and the DU may depend on the applied implementation.

[0089] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example, a terminal device may be referred to as a communicationdevice, user equipment (UE), a Subscriber Station (SS), or a Mobile Station (MS). The terminal device may include a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehiclemounted wireless terminal devices, USB dongles, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like.

[0090] A term “resource”, as used herein, may refer to radio resources in time domain, in frequency domain, in space domain, and / or in code domain. Some examples of resources include e.g. a physical resource block (PRB), a radio frame, a subframe, a time slot, a subband, a frequency region, a sub-carrier, a beam, etc. The term “transmission” and / or “reception” may refer to wirelessly transmitting and / or receiving via a wireless propagation channel on radio resources.

[0091] FIG. 1 illustrates an example of a communication network to which one or more examples disclosed herein may be applied. The communication network may be a cellular communication network may comprise a network node 110 providing one or more cells, such as cell 100, and a network node 112 providing one or more other cells, such as cell 102. Each cell may be, e.g., a macro cell, a micro cell, femto, or a pico cell, for example. The cell may define a coverage area or a service area of the corresponding access node.

[0092] The network node 110 may provide a user equipment (UE) 120 (one or more UEs) with wireless access to the communication network. The wireless access may comprise downlink (DL) communication from the network node to the UE 120 and uplink (UL) communication from the UE 120 to the network node. Examples of uplink channels comprise physical uplink control channel (PUCCH) for transmitting control information and physical uplink shared channel (PUSCH) for transmitting data towards the network. Examples of downlink channels comprise physical downlink control channel (PDCCH) for transmitting control information and physical downlink shared channel (PDSCH) for transmitting data towards the user equipment.

[0093] There may be a plurality of UEs 120, 122 in the system. Each of them may be served by the same or by different network nodes 110, 112. UE may be configured with dual connectivity (DC), wherein the UE, e.g. UE 120, may be connected to multiple network nodes 110, 112. The UEs 120, 122 may communicate with each other, in case device-to-device (D2D) communication interface is established between them via a so-called sidelink (SL). Such D2D communications may be referred to as machine-to-machine, peer-to-peer (P2P) communications, or vehicle-to-vehicle (V2V), for example.

[0094] In the case of multiple network nodes in the communication network, the network nodes may be connected to each other via an interface. LTE specifications refer to such an interface as an X2 interface. An interface between an LTE node and a 5G node, or between two 5G nodes may be called an Xn interface.

[0095] The network nodes 110 and 112 may be further connected via another interface to a core network 116 of the communication network. The LTE specifications specify the core network as an evolved packet core (EPC), and the core network may comprise e.g. a mobility management entity (MME) and a gateway node. The MME may handle mobility of terminal devices in a tracking area encompassing a plurality of cells and handle signaling connections between the terminal devices and the core network. The gateway node may handle data routing in the core network and to / from the terminal devices. The 5G specifications specify the core network as a 5G core (5GC). The 5G core may comprise e.g. an access and mobility management function (AMF) and a user plane function / gateway (UPF) and other functions. The AMF may handle termination of non-access stratum (NAS) signaling, NAS ciphering & integrity protection, registration management, connection management, mobility management, access authentication and authorization, security context management. The UPF node may support packet routing and forwarding, packet inspection and quality of service (QoS) handling, for example.

[0096] In 3GPP Rel-18, a mobility mechanism was introduced, namely lower layer-triggered mobility (LTM), which aims to reduce interruption time during handover. LTM may refer to a procedure that allows a change of serving cell to be initiated through layer 1 / layer 2 (L1 / L2) signaling. L1 / L2 signaling refers to signaling that supports the transmission of uplink and downlink transport channels. L1 / L2 signaling includes signaling of information that originates from both the physical layer (layer 1 (LI)) and the MAC layer (layer 2 (L2)). In other words,information carried via L1 / L2 signaling partly originates from the physical layer (Layer 1) and partly from MAC (Layer 2). In other words, LTM is a cell switch procedure, in which a serving cell (PCell or PSCell) for a UE is switched by the network through an LTM cell switch command. An LTM switch command may be delivered by MAC signaling using a MAC CE rather than RRC signaling as a L3 based handover. An LTM cell switch decision may be based on LI measurements that are performed and reported by the UE using LI measurement reports . Measurements and reporting are based on LTM candidate cell configuration(s) provided by the network for one or more LTM candidate cells. An LTM candidate cell may be neighboring cells or the current serving cells (e.g. S Cells) for the UE. LTM may lead to reduced latency, overhead, and interruption time during handover.

[0097] In Release- 18, LTM measurements on a neighboring candidate cell are performed using SSBs transmitted by the candidate cell for which the SSB configuration is provided to the UE.

[0098] Before the cell switch, the network may optionally activate one or more TCI state(s) for one or more candidate cells. Once a candidate cell TCI state is activated, the UE may start tracking the time / frequency synchronization using the reference signals associated with the activated TCI state(s). The UE may also perform early UL synchronization before the cell switch if this is requested by the network.

[0099] The system may support a split gNB architecture to allow distributed RAN network and disaggregation of one or more RAN network elements. In some instances, however, the split to multiple network entities / components, necessitates, for various configurations, multiple and relatively long messages to be exchanged between the centralized unit control plane (CU-CP) and DU (or centralized unit user plane (CU-UP) and DU) irrespective of a type of service a UE is utilizing. Such signaling may lead to increased latency and relatively high CPU processing. To reduce a latency associated with measurement reporting by a UE, the network may support lower layer triggered mobility (LTM), which may provide for reduced interruption times and execution delays including, for example, interruption times and execution delays for switching between cells controlled by a same CU. Unlike higher layer mobility procedures, such as layer 3 (L3) based mobility procedures in which handover decisions are based on L3 cell quality measurement results, handover in LTM may be triggered by the MAC layer (L2) in the DU based on LI beam measurement results. In other words, LTM may provide for reduced latenciesassociated with measurement reporting by the UE through utilization of MAC layer signaling. However, in some instances, the UE (and the network) may lack a mechanism for LTM measurement reporting at the MAC layer. For example, the UE may lack (e.g., may not be configured with) a MAC CE format that supports LTM measurement reporting In other words, a MAC CE format that supports LTM measurement reporting may not be defined.

[0100] Various aspects of the present disclosure provide medium access control (MAC) control element (CE) formats for LTM measurement reporting. In accordance with one or more MAC CE formats of the present disclosure, the UE 120 (or the UE 122) may receive control information indicative of one or more reference signals, within one or more candidate cells, to monitor for one or more events associated with LTM reporting. In some examples, the UE 120 may provide for one or more measurements of the one or more reference signals in accordance with the control information. In some such examples, the UE 120 may identify, based at least in part on the one or more measurements, an occurrence of at least an event of the one or more events for at least a candidate cell of the one or more candidate cells. In response to identifying the occurrence of the event, the UE 120 may transmit a MAC CE including an LTM report. The MAC CE may include a MAC CE format for LTM reporting as described in accordance with one or more examples disclosed herein. For example, the MAC CE may include a bit field that is indicative of at least the candidate cell.

[0101] FIG. 2 illustrates an example signaling diagram for LTM to which one or more examples disclosed herein may be applied. As illustrated in the example of FIG. 2, the UE 120 and the network node 110 may be configured to perform one or more operations to support LTM measurement reporting in accordance with one or more examples of the present disclosure.

[0102] In step 1 of FIG. 2, the UE 120, sends a MeasurementReport message to the gNB 110, which provides access to the source cell 100. The gNB 110 decides to configure LTM and initiates LTM preparation.

[0103] In step 2 of FIG. 2, the gNB 110 transmits an RRC Reconfiguration message to the UE 120 including the LTM candidate configurations.

[0104] In step 3 of FIG. 2 the UE 120 stores the LTM candidate configurations and transmits an RRCReconfigurationComplete message to the gNB 110.

[0105] In step 4a of FIG. 2, the UE 120 performs DL synchronization with the candidate cell(s) 102 before receiving the cell switch command.

[0106] In step 4b of FIG. 2, when the UE-based TA measurement is configured, the UE 120 acquires the TA value(s) of the candidate cell(s) 102 by measurement. The UE 120 performs early TA acquisition with the candidate cell(s) 102 as requested by the network before receiving the cell switch command as specified in clause 9.2.6. This is done via CFRA triggered by a PDCCH order from the source cell 100, following which the UE 120 sends preamble towards the indicated candidate cell 102. In order to minimize the data interruption of the source cell 100 due to CFRA towards the candidate cell(s) 102, the UE 120 does not receive a random access (RA) response from the network for the purpose of TA value acquisition and the TA value of the candidate cell 102 is instead indicated in the cell switch command. The UE 120 does not maintain the TA timer for the candidate cell 102 and relies on network implementation to guarantee the TA validity.

[0107] In step 5 of FIG. 2 the UE 120 performs LI measurements (e.g., reference signal received power (RSRP) measurements) on the configured candidate cell(s) 102 and transmits one or more LI measurement reports to the source gNB 110. LI measurement should be performed as long as the RRC reconfiguration (from step 2) is applicable. The UE 120 may transmit the LI measurement report(s) in accordance with one or more MAC CE formats disclosed herein.

[0108] In step 6 of FIG. 2, the gNB 110 decides to execute a cell switch from the source cell 100 to the candidate or target cell 102 and transmits a MAC CE triggering cell switch by including the candidate configuration index of the target cell 102. The UE 120 then switches to the target cell 102 and applies the configuration indicated by candidate configuration index.

[0109] In step 7 of FIG. 2, the UE 120 performs the RA procedure towards the target cell 102, for example, if the UE 120 does not have a valid TA of the target cell 102 (e.g., as specified in TS 38.321).

[0110] In step 8 of FIG. 2, the UE 120 completes the LTM cell switch procedure by sending RRCReconfigurationComplete message to the gNB 112 providing access to the target cell 102.

[0111] The steps 4-8 can be performed multiple times for subsequent LTM using the LTM candidate configuration(s) provided in step 2.

[0112] The procedure over the air interface described above is applicable to both intra-gNB- DU LTM and inter-gNB-DU LTM. One or more operations of the LTM procedure may be configured at the UE (e.g., in accordance with TS 38.401, which may define the overall LTM procedures over Fl-C interface).

[0113] If the UE 120 has performed a RA procedure in step 7 of FIG. 2, then the UE 120 considers that LTM cell switch execution is successfully completed when the RA procedure is successfully completed.

[0114] For RACH-less LTM, the UE 120 considers that the LTM cell switch execution is successfully completed when the UE 120 determines that the network has successfully received first UL data.

[0115] As illustrated in FIG. 2, in LTM, early TA acquisition (e.g., TA acquisition before handover / cell switch) can be performed in one or more ways. In some examples, the network can order the UE 120 to perform RA preamble transmission to a candidate cell 102. The candidate cell 102 uses the received RA preamble to estimate the TA and provides the TA estimate to the source cell 100. When the source cell 100 decides to trigger the cell switch, the source cell provides the estimated TA value along with the cell switch command.

[0116] Additionally, or alternatively, during LTM preparation, the network can configure the UE 120 to perform UE-based TA measurements. UE-based TA measurements may be performed based on the TA of the serving cell 100 and the measured time difference between the candidate cell 102 and the serving cell 100. After being configured, the UE 120 is assumed to obtain a TA measurement before a cell switch command is issued by the gNB 110 providing access to the source cell 100.

[0117] Another purpose served by random access is that the target gNB 112 is notified about the presence of the UE 120 and resources for the UE’s subsequent transmissions are provided to the UE 120. Hence, when RACH-less LTM cell switch is performed, a mechanism is required to support the initial transmission of the UE 120 to the target cell 102. A mechanism that supports this purpose is the provisioning of configured grants, which consist of sets of resources in the candidate / target cell that the UE 120 may use if / when the UE performs an initial transmission after handover / cell switch to the target cell 102. An alternative to this mechanism is to provide an access notification from the source cell 100 to the target cell 102, so that the target cell 102 can then provide a dynamic grant to the UE 120 for the target cell 102.

[0118] A similar RACH-less approach has also been proposed for baseline and conditional handover (BHO / CHO) as well to facilitate fast cell switch.

[0119] FIG. 3 illustrates an example diagram of an LTM configuration to which one or more examples disclosed herein may be applied. In some examples of LTM (e.g., in Release-18 LTM),information about measurement resources (e.g., synchronization signal blocks (SSBs)) from LTM candidate cells is provided to a UE (e.g., the UE 120) for UE measurements. As used herein SSBs may also be referred to herein as synchronization signal / physical broadcast channel (SS / PBCH) blocks. The UE is also configured with LI measurement reporting configuration(s) according to which the UE can report the measurements. For LTM, periodic and semi-persistent reports may be transmitted on the PUCCH, semi-persistent reports may be transmitted on the PUSCH, and aperiodic reports may be transmitted on PUSCH.

[0120] The UE may be configured with one or more LTM CSI reporting configurations, such as an LTM-CSI-ReportConfig 310, in which the LTM-CSI-ReportConfig 310 includes (e.g., in each reporting configuration) an LTM CSI resource configuration, such as an LTM-CSI- ResourceConfig 312, which includes information of resources to be used for channel measurements (Ll-RSRP measurements). For an LTM CSI reporting configuration (e.g., each LTM CSI reporting configuration), the UE may be configured to report measurements for M beams from one or more of the L configured candidate cells (e.g., for each of the L configured candidate cells). In other words, each LTM CSI resource setting (e.g., in the LTM-CSI- ResourceConfig 312) includes configuration information of an information element (IE), such as information of an LTM-CSI-SSB-ResourceSei \E 314, which includes a list of Z > 1 SS / PBCH blocks indices (given by Itm-CSI-SSB-ResourceList 316) and a list of Z LTM-Candidatelds (given by Itm-CandidatelDListlE 318) referring to candidate cells associated with SSB indices (e.g., SS / PBCH block indices).

[0121] FIG. 4 illustrates an example diagram of components of an LTM configuration to which one or more examples disclosed herein may be applied. In some examples, a UE (e.g., the UE 120, 122) may be configured with one or more LTM configurations, which include one or more components (e.g., an LTM CSI resource configuration 412, LTM candidate cells, LTM report configurations) placed in accordance with the example diagram of FIG. 4. As illustrated in the example of FIG. 4, for a candidate cell (e.g., each candidate cell), the UE determines the time domain behavior of a SS / PBCH block resource from ssb-Periodicity and ssb-PositionsInBurst IES and determines the frequency domain behavior of a SS / PBCH block resource by the higher layer parameters subCarrier Spacing and ssbFrequency.

[0122] For a cell (e.g., each cell), LTM CSI report configuration(s) are given under serving cell configuration (e.g., a current serving cell configuration), in which each report configurationincludes an indication of the LTM CSI resource configuration 412 and other parameters for reporting (e.g., timing and uplink resources for the UE to transmit reports).

[0123] An LTM CSI resource configuration 412 (e.g., LTM CSI Resource Config 1, LTM CSI Resource Config 2, LTM CSI Resource Config 3) may include a set of SSB indices from multiple candidate cells. The set of SSB indices may be placed in a common LTM configuration, (e.g., in an LTM-Config R 410).

[0124] A configuration for each SSB of a candidate cell indicated in a LTM CSI resource configuration 412 may be provided in an LTM-SSB-Config under LTM-Candidate IE. For each candidate cell, the LTM-Candidate IE includes the configuration / information, which is needed by the UE before the cell switch (e.g., SSB information for LTM measurements).

[0125] The LTM-Candidate IE also includes the list of NZP-CSI-RS resources, which are used to provide the information for activation of TCI states associated with tracking RS (a type of CSI-RS). The listed resources may be used for LTM measurements with CSI-RSs.

[0126] An LTM-Candidate IE also includes RRC container (e.g., ServingCellConfig), which includes the configuration information that may be used by the UE after the UE switches to the corresponding candidate cell after the cell switch from the current serving cell. In other words, a ServingCellConfig given under an LTM-Candidate IE includes the configuration information used to perform one or more serving cell operations within the candidate cell.

[0127] Information regarding values of IES of the LTM-CSI-ReportConfig, LTM-CSI- ResourceConfig, and LTM-CSI-SSB-ResourceSet may be configured at the UE (e.g., in accordance with TS 38.331). In some examples, the IE LTM-CSI-ReportConfig is used to configure report on the cell in which the LTM-CSI-ReportConfig is included. Tables 1 and 2 provide examples of information provided for the LTM-CSI-ReportConfig IE.

[0128] The IE LTM-CSI-ReportConfigld is used to identify an LTM-CSI-ReportConfig.Tables 3 and 4 provide examples of information provided for the LTM-CSI-ReportConfigld IE.

[0129] LTM may provide improvements in handover latency and interruption time compared to Layer 3 based mobility. However, LTM (e.g., as introduced in Rel-18), may be associated with a number of constraints compared to Layer 3 mobility. One or more features, such as CSI- RS measurement features, may be incorporated into LTM to reduce the number of constraints associated with LTM. For example, LTM may incorporate one or more measurement features pertaining to Intra-CU MCG / SCG LTM and Inter-CU MCG / SCG LTM, one or more features to support event triggered LI measurement reporting, one or more features to support event triggered measurements for MIMO, one or more features to support CSLRS measurements for LTM procedures and enabling CSLRS based beam management, and / or one or more other features to support physical layer operations on candidate cells prior to LTM.

[0130] Referring back to FIG. 1, the system may support one or more designs for event triggered LI measurements for LTM. For example, the system may support selection of candidate beam(s) / cell(s) to trigger early synchronization, selection of target beam(s) / cell(s) and triggering of an LTM cell switch procedure, event triggered LI measurements (which may include the use of beam level measurement results as a baseline for event evaluation), and / or LTM events based on beam-specific quality of serving cell and candidate cells as the LI LTM measurement events. In some examples, the system may support an Event LTM2 in which a beam of a serving cell becomes worse than absolute threshold. Additionally, or alternatively, the system may support an Event LTM3, in which a beam of a candidate cell becomes better than a beam of the serving cell by a specified offset. Additionally, or alternatively, the system may support an Event LTM4, in which a beam of a candidate cell becomes beter than an absolute threshold. Additionally, or alternatively, the system may support an Event LTM5, in which a beam of a serving cell becomes worse than an absolute threshold and a beam of candidate cell becomes beter than another absolute threshold.

[0131] In some examples, the system may support one or more rules for determining beam(s) of the serving cell and neighboring cell to use for event evaluation. Additionally, in some examples, the system may support beam configurations for both SSB and CSI-RS in LI measurement in a resource configuration in LTM-config (e.g., as illustrated by and described with reference to FIG. 4). In some such examples, a same reference signal type may be used for both the serving cell and one or more neighboring cells for Event LTM3 and Event LTM5. In some examples, filtering of the LI measurement results is used. Such filtering may be configured by the network or performed according to a UE implementation. In some examples, for LTM event evaluations, timetotrigger (TTT), hysteresis for entering / leaving, and / or beam specific (or cell specific) offsets may be applied. Accordingly, in some examples, the system may support one or more rules for measurement reporting once a leaving condition is satisfied.

[0132] In some examples, an LI measurement report may be carried using UCI (e.g., LI signaling is used to carry the reported measurements). A format of LI measurement report may be configured at the UE (e.g., in accordance with 38.212). In some examples, the UE may be configured with a mapping order of CSI fields of a report for SSBRI / RSRP reporting for LTM (e.g., in accordance with one or more tables provided in TS 38.212).

[0133] A reporting configuration for LTM (or a portion thereof) may be provided by an LTM-TCI-Info IE. For example, the IE LTM-TCI-Info may be used to configure TCI related information for an LTM candidate configuration. The LTM-TCI-Info IE may include a unifiedTCI-StateType parameter that indicates the unified TCI states type the UE is configured for this LTM candidate configuration. In some examples, the unifiedTCI-StateType parameter may be set to “separate” or “joint.”The value “separate” means this LTM candidate configuration is configured with Itm-DL-OrJointTCI-StateToAddModList for DL TCI states and Itm-UL-TCI- StatesToAddModList for UL TCI states. The value “joint” means this LTM candidate configuration is configured with Itm-DL-OrJointTCI-StateToAddModList for joint TCI states for uplink (UL) and downlink (DL) operation.

[0134] In some examples, the UE may be configured with up to M LTM candidate cells. For the event triggered LTM reporting, the reporting event may be triggered for one or more cells simultaneously. Accordingly, signaling for LTM reporting may support reporting for multiple cells simultaneously.

[0135] A UE may be configured to use MAC layer signaling for LI measurement reporting. MAC layer signaling may provide increased flexibility for resource management, as well as reduced CPU processing relative to higher layer signaling. Additionally, MAC layer signaling may provide for faster and more efficient control of resource allocation and traffic prioritization, which may reduce latency for communications within a network.

[0136] FIG. 5 A and FIG. 5B illustrate examples of MAC subheaders to which one or more examples disclosed herein may be applied. For example, FIG. 5 A shows an example of a downlink MAC PDU and FIG. 5B shows an example of an uplink MAC PDU.

[0137] A MAC PDU is a bit string that is byte aligned (e.g., multiple of 8 bits) in length. The bit strings are represented by tables in which the most significant bit is the leftmost bit of the first line of the table, the least significant bit is the rightmost bit on the last line of the table, and more generally the bit string is to be read from left to right and then in the reading order of the lines. The bit order of each parameter field within a MAC PDU is represented with the first and most significant bit in the leftmost bit and the last and least significant bit in the rightmost bit.

[0138] A MAC SDU is a bit string that is byte aligned (e.g., multiple of 8 bits) in length. A MAC SDU is included into a MAC PDU from the first bit onward. A MAC CE is a bit string that is byte aligned (e.g., multiple of 8 bits) in length. A MAC subheader is a bit string that is byte aligned (e.g., multiple of 8 bits) in length. Each MAC subheader is placed immediately in front of the corresponding MAC SDU, MAC CE, or padding. The MAC entity shall ignore the value of the Reserved bits in downlink MAC PDUs.

[0139] Referring to FIG. 5A and 5B, the MAC PDU comprises one or more MAC subPDUs. Each MAC subPDU comprises one of the following: a MAC subheader only (including padding); a MAC subheader and a MAC SDU; a MAC subheader and a MAC CE; or a MAC subheader and padding. The MAC SDUs may have variable sizes.

[0140] Referring back to FIG. 5A and 5B, the MAC CEs may be grouped together (e.g., concatenated). DL MAC subPDU(s) with MAC CE(s) is placed before any MAC subPDU with MAC SDU and MAC subPDU with padding. UL MAC subPDU(s) with MAC CE(s) is placed after all the MAC subPDU(s) with MAC SDU and before the MAC subPDU with padding in the MAC PDU. The size of padding can be zero. In some examples, a maximum of one MAC PDU can be transmitted per TB per MAC entity.

[0141] In some cases, the UE may lack a MAC CE format that supports LI measurement reporting, much less LI measurement reporting for multiple cells simultaneously. Various aspects of the present disclosure provide one or more designs for a MAC CE format for LTM event triggered reporting of LI measurements, which may lead to improved performance of LTM reporting within a communication network. In other words, the present disclosure provides for one or more MAC CE formats that support event triggered LTM reporting for one or more candidate cells.

[0142] FIG. 6A and FIG. 6B illustrate examples of an octet of a MAC CE format to which one or more examples disclosed herein may be applied. In some examples, the UE may be configured with a MAC CE format for an LTM event triggered measurement report that supports LI measurement reporting for one or multiple candidate cells. For example, the UE may be configured with a single-cell MAC CE format that supports measurement reporting for a single candidate cell and / or a multi-cell MAC CE format that supports measurement reporting for one or multiple candidate cells.

[0143] In some examples, the multi-cell MAC CE format includes a candidate cell identifier field 610, in which RRC configured candidate cell identifiers (e.g., LTM Cl through LTM C8) are mapped to bit positions in the candidate cell identifier field 610. In other words, the candidate cell identifier field 610 includes a bitmap in which each bit position of the bit map corresponds to a candidate cell identifier associated with a particular candidate cell. As illustrated in the example of FIG. 6A, a first candidate cell identifier (LTM Cl) of a first candidate cell is mapped to a first bit position 612 and a fourth candidate cell identifier (LTM C4) of a fourth candidate cell is mapped to a fourth bit position 614.

[0144] In some examples, for a bit position (e.g., each bit position) for which the bit is set to a first value (e.g. ‘ 1 ’), the bit indicates that at least one reporting event has occurred for a beam within the candidate cell associated with the bit position. In some such examples, the MAC CE may further encode at least one reference signal identifier (referred to herein as an RS index) or a reference signal identifier and measurement value pair (referred to herein as RS index+RSRP pair) for the candidate cell indicated by the bit. In some examples, the reference signal identifier (e.g., RS-index) may refer to resource indicator. The resource indicator may refer to a reference signal index / identifier in the measurement resource configuration (e.g. CSI resource configuration). In some examples, a CSI resource configuration may be provided for (e.g.,specific to) LTM. In some examples, for a bit position for which the bit is set to the first value (e.g. ‘ 1 ’), the MAC CE may further encode at least one RS index or RS index+RSRP pair for the corresponding cell indicated by the bit. Additionally, for some examples in which a bit position for which the bit is set to a second value (e.g. ‘0’), the bit indicates that no reporting event has been triggered for the candidate cell and the MAC CE does not encode RS index values (or RS index+RSRP pair values) for the candidate cell. In some examples the measurement value may refer to signal to interference and noise ratio (SINR).

[0145] As illustrated in the example of FIG. 6A, the candidate cell identifier field 610 may be included in an octet (Oct 1) of the MAC CE. In some examples, the bit positions in the bitmap map to candidate cell identifiers in ascending order of the candidate cell identifiers. That is, each bit position in the bitmap is mapped to a LTM candidate cell identifier in ascending order of the candidate identifiers (e.g., provided in the LTM configuration). In some such examples, the first bit position (LTM Cl) maps to the lowest configured candidate cell identifier (e.g., LTM candidate ID). In other words, the first bit position maps to a candidate cell identifier with a lowest value among a set of configured candidate cell identifiers. For example, the UE may be configured with a set of candidate cell identifiers including Candidate ID #rl, Candidate ID #r2, and Candidate ID #r3. In such an example, Candidate ID #rl may correspond to the lowest configured candidate cell identifier and, as such, may be mapped to the first bit position (LTM Cl). Additionally, the next bit position (e.g., the following bit position, the second bit position, LTM C2) may map to the second lowest candidate identifier. For example, Candidate ID #r2 may correspond to the next lowest configured candidate identifier (e.g., the second lowest candidate cell identifier) and, as such, may be mapped to the next lowest bit position (e.g., the second lowest bit position, LTM C2). In other words, the bit positions map to configured LTM candidate identifiers in ascending order of the configured LTM candidate identifiers. In some examples, the LTM candidate IDs are configured via RRC signaling.

[0146] In some examples, up to k candidate identifiers may be supported. In some such examples, the bitmap may have a length that is an integer multiple of k. As an illustrative examples, up to 8 candidate identifiers may be supported and the bitmap map have a length of 8,16 etc. bits. In the example of FIG. 6A, the bitmap includes an 8 bit bitmap. In some examples, if the quantity of candidate cell identifiers is less than the quantity of bit positions in the bitmap, bit values in the bit positions not mapping to LTM candidate cell identifiers are not encoded orare set to a particular value. As an illustrative example, for the set of candidate cell identifiers including Candidate ID #rl, Candidate ID #r2, and Candidate ID #r3, the fourth bit position 614 may not be encoded or may be set to a particular value (e.g., a value other than the first value).

[0147] In some examples, in accordance with the multi-cell MAC CE format, the UE may set the bit to the first value (e.g. ‘ 1 ’) to indicates that at least one event triggered reporting event has been triggered for the indicated candidate cell by the bit position. In some such examples, the UE may set the bit to the second value (e.g. ‘0’) to indicate that no event has occurred for the candidate cell identifier mapped to the bit position. In some examples, by setting the bit to the first value (e.g. ‘ 1’), the UE may further indicate that, for the corresponding candidate cell identifier (e.g., mapped to the bit position of the bit), at least one RS index is included in the MAC CE. In some such examples, the RS index corresponds to a reference signal for which the event triggered reporting criteria has been satisfied. In some examples, RS index values included in the MAC CE are listed in the order of the reported candidate cells. In some examples, one or more RS index values are included in the MAC CE as an RS index+RSRP pair.

[0148] In accordance with the one or more aspects of the present disclosure, the UE may be configured with a single cell MAC CE format. That is, the UE may be configured with a MAC CE format for an LTM event triggered measurement report that supports LI measurement reporting for a single candidate cell. As illustrated in the example of FIG. 6A, the single cell MAC CE format may include at least a bit field (e.g., a candidate ID field 616) that indicates a single candidate cell identifier, in which the candidate cell identifier indicates that at least one reporting event has been triggered for the corresponding candidate cell. In some examples, for the indicated candidate cell in the candidate ID field 616, the MAC CE may list at least one RS index or RS index+RSRP pair. FIG. 6B illustrates an example of an octet included in the MAC CE. In some such examples, the candidate cell identifier may be encoded in the same octet (e.g., octet 1) as an event identifier. In other words, the single cell MAC CE format may include at least one octet that indicates the candidate cell identifier and the event identifier. In the example of FIG. 6B, the octet of the MAC CE (e.g., octet 1) may include the candidate ID field 616 for the candidate cell identifier and an event ID field 618 for the event identifier. In other words, the candidate ID field 616 and the event ID field 618 may be in the same octet.

[0149] In some examples, the UE may be configured to select a MAC CE format (e.g., the single-cell MAC CE format or the multi-cell MAC CE format) for event triggered reportingbased on one or more rules and / or parameters. For example, the UE may select a MAC CE format based on a quantity of configured candidate cell identifiers associated with the reference signals in a reference signal resource set used for evaluating the event. As an illustrative example, if a resource set for evaluating the event (e.g., the measurement resource set) is associated with a reference signal of one cell, the UE may use the single-cell MAC CE format. As another illustrative example, if the resource set for evaluating the event (e.g., the measurement resource set) is associated with a reference signal of more than one cell, the UE may use the multi-cell MAC CE format.

[0150] In some examples, if the quantity of candidate cells for which the reporting event has been triggered is one, the UE may select the single-cell MAC CE format. In some other examples, if the quantity of candidate cells for which the reporting event has been triggered is more than one, the UE may select the multi-cell MAC CE format. In some examples, if one candidate cell is configured for the UE, the UE may use the single-cell MAC CE format. In some other examples, if more than one or more than K candidate cells (where K is a value preconfigured at the UE) are configured at the UE, the UE may use the multi-cell MAC CE format.

[0151] FIG. 7 illustrates an example diagram of encoded candidate cell information in a MAC CE format to which one or more examples disclosed herein may be applied. As illustrated in the example of FIG. 7, the MAC CE may include a first octet (Oct 1) that includes a candidate identifier field, which may be an example of a candidate identifier field illustrated by and described with reference to FIG. 6A. In some examples, the candidate cell identifier field includes a bitmap in which each bit position of the bit map corresponds to a candidate cell identifier associated with a particular candidate cell. The candidate cell identifiers are associated with reference signal identifiers. For example, each candidate cell identifier may be associated with one or more respective reference signal identifiers. As illustrated in the example of FIG. 7, the reference signal identifiers may be listed in the MAC CE in the order of the candidate cell identifiers indicated by the candidate cell identifier bitmap.

[0152] In any of the examples provided herein the term ‘octet’ may be used interchangeably with the term ‘bitfield.’ For example, while octets may be referred to herein, it is to be understood that another type of bit filed comprising one or more bits or one or more 8-bit groups may be used.

[0153] For example, a first bit position 712 may map to a first candidate identifier associated with first candidate cell information 716. In such an example, the first candidate cell information 716 includes a first reference signal identifier and a first RSRP value associated with the first reference signal identifier. That is, the first candidate cell information 716 includes a first reference signal identifier and an RSRP value measured for a reference signal corresponding to the first reference signal identifier. Additionally, a third bit position 714 may map to a third candidate identifier associated with third candidate cell information 718. The third candidate cell information 718 includes a third reference signal identifier and a third RSRP value associated with the third reference signal identifier. That is, the third RSRP value includes an RSRP value measured for a reference signal corresponding to the third reference signal identifier. In such an example, the third candidate cell information 718 follows the first candidate cell information 716 based on the third candidate cell being mapped to the third bit position 714, which follows the first bit position 712. In other words, the third candidate cell information 718 is listed after the first candidate cell information 716 based on the associated candidate cell identifiers having an order in which the third candidate cell identifier is listed after the first candidate cell identifier. In the example of FIG. 7, the third candidate cell information may follow (e.g., come immediately after) the first candidate cell information based on a bit in a second bit position (LTM C2) indicating that no reporting event has been triggered for a second candidate cell associated with the second bit position. The examples in FIG. 7 illustrate reporting of one RS index for each candidate cell for which the reporting is indicated. The UE may be configured to report up to N RS index values per candidate cell in which the reported RS index values fulfill the event reporting criteria (such as LTM3 event criteria).

[0154] In some examples, the order of the RS index and / or associated measurement result (e.g. RSRP value) for the candidate cells in the MAC CE is based on the value of the associated measurement result. That is, in some examples, the order of the RS index and / or associated the measurement results are included in the MAC CE in the order of the reported RSRP value. In other words, an RS index associated with the highest measured RSRP value among the RSRP values measured by the UE may be included in the MAC CE first (e.g., in a lowest numbered octet among octets in the MAC CE carrying RS index values associated with measured RSRP values). The RSRP values may be used for determining the listing order of RS index for each reported candidate cell. In some examples, the RS index values that are listed inthe MAC CE are the RS index values that fulfill the reporting criterion (such as LTM3) for the reported candidate cells. In one example, the RSRP value of the first candidate cell information 716 may be greater than the RSRP value of the third candidate cell information 718.Accordingly, the first candidate cell (identifier)may be mapped to a lower bit position (e.g., the first bit position 712, LTM Cl) than the third candidate cell (identifier), and the first RS index corresponding to the first candidate cell may be listed before the third RS index corresponding to third candidate cell.

[0155] FIG. 8 illustrates an example of a MAC CE format to which one or more examples disclosed herein may be applied. As illustrated in the example of FIG. 8, the MAC CE format may include a bitmap in a first octet (Oct 1) of the MAC CE. In some examples, a bit of the bitmap may map to a candidate cell identifier corresponding to a candidate cell configured at the UE for LTM reporting. In some such examples, the candidate cell identifier may map to one or more reference signal identifiers (e.g., RS index values) and one or more associated measurement values (e.g., RSRP values). In some examples, an RSRP value associated with a reference signal identifier is reported in the octet following (e.g., in the octet immediately after) an octet carrying the reference signal identifier. For example, a first reference signal identifier associated with a first candidate cell (Cl, that maps to LTM Cl) may be reported in Oct 3 and an RSRP value associated with the first reference signal identifier may be reported in Oct 4.

[0156] FIG. 9 illustrates an example of octets in a MAC CE format to which one or more examples disclosed herein may be applied. As illustrated in the example of FIG. 9, the MAC CE may include one or more pairs of octets carrying one or more reference signal identifier and measurement value pairs. In some examples, a reference signal identifier and measurement value pair (RS index+RSRP pair) may be reported for one or more candidate cells. As illustrated in the example of FIG. 9, the reference signal identifier (RS index) of the reference signal identifier and measurement value pair may precede (e.g., be carried in the RSRP value of the reference signal identifier and measurement value pair. For example, the RS ID (RS index) may be reported in an octet (Oct 1) and the RSRP value may be reported in the following octet (Oct 2).

[0157] FIG. 10 illustrates an example of octets in a MAC CE format to which one or more examples disclosed herein may be applied. As illustrated in the example of FIG. 10, the MAC CE format may include one or more octets to list reference signal identifiers and one or more octets to list associated RSRP values. In some examples, the MAC CE format lists the referencesignal identifiers first and lists the RSRP values. For example, the MAC CE may report a set of N reference signal identifiers and a set of M measurement values, in which a measurement value of the set of M measurement values is associated with a respective reference signal identifier of the set of N reference signal identifiers. As illustrated in the example of FIG. 10, the set of reference signal identifiers may be listed in a first set of octets 1010 and the set of associated measurement values may be listed in a second set of octets 1012 following (e.g., immediately after) the first set of octets. In such an example, an order in which the measurement values are listed in the second set of octets 1012 may be based on an order in which the reference signal identifiers are listed in the first set of octets 1010. That is, an order of the measurement values is based on the order of associated the reference signal identifiers. For example, a first measurement value 1014 (RSRP#1) may be reported in a first octet of the second set of octets 1012 based on the first measurement value 1014 being associated with a first reference signal identifier 1016 (RS ID#1) reported in a first octet (Oct 1) of the first set of octets 1010. Additionally, a last measurement value 1018 (RSRP#N) may be reported in a last octet of the second set of octets (Oct M) based on the last measurement value 1018 being associated with a last reference signal identifier 1020 (RS ID#N) reported in a last octet of the first set of octets.

[0158] In some examples, a candidate cell may be associated with one or multiple reference signal identifiers (and one or more associated RSRP values). For example, for a candidate cell (e.g., each candidate cell) indicated in the candidate cell identifier field in the MAC CE, one or more RS index values that satisfy the reporting criteria may be included in the MAC CE. In other words, for a reference signal for which a measurement value satisfies a criterion associated with an LTM report for a candidate cell, the UE may report the measurement value and / or an RS index value corresponding to the reference signal in the MAC CE. In some examples, multiple reference signals may have measurement values that satisfy the criterion associated with the LTM report for the candidate cell. In some such examples, the UE may report the multiple measurement value and / or multiple RS index values corresponding to the multiple reference signals in the MAC CE. In some examples, the UE may be configured with a quantity of measurements (e.g., a number of reference signals or beams for which information is reported) to report for a candidate cell via the MAC CE.

[0159] FIG. 11 illustrates an example of octets in a MAC CE format to which one or more examples disclosed herein may be applied. As illustrated in the example of FIG. 11 , the UE maydetermine (e.g., may be configured) to report LI measurements for the current serving cell of the UE. The current serving cell corresponds to a serving cell with which the UE has established a connection (e.g., Primary Cell, PCell or PSCell or SCell, Secondary Cell). That is, in some examples, serving cell inclusion may be configured at the UE. In some such examples, serving cell information may be listed in a MAC CE (e.g., the multi-cell MAC CE format or the single cell MAC CE format) before candidate cell information for one or more candidate cells. In other words, an RS index or RS index+RSRP pair for the serving cell may be listed in one or more octets within the MAC CE that are lower in number than (e.g., precede) one or more octets carrying RS index values or RS index+RSRP pairs for candidate cell(s). In other words, the serving cell information may precede candidate cell information in the MAC CE. The reported serving cell information may correspond to the serving cell reference signal used for evaluation of the reporting criteria for the reported reference signals and / or candidate cells. In some examples, the RS index may be reported for the serving cell reference signal included in the MAC CE. In some examples, the RS index and RSRP value pair may be reported for the serving cell reference signal included in the MAC CE.

[0160] In some examples, the serving cell information may precede the candidate cell information by being in one or more lower numbered octets than one or more octets carrying the candidate cell information. For example, the serving cell information may be included in a first octet and first candidate cell information may be included in one or more octets following the first octet. As an illustrative example, the serving cell information may include an RSRP value for the serving cell and the candidate cell information may include an RS index+RSRP pair for the candidate cell. In such an example, the RSRP value for the serving cell may be included in Oct 1, an RS index corresponding to a candidate cell (e.g., a first candidate cell) may be included in Oct 2, and an RSRP value corresponding to the RS index for the candidate cell may be included a third octet (Oct 3).

[0161] In some examples, the serving cell inclusion may mean that the RSRP value for the serving cell and an RS index corresponding to the RSRP value are reported. In some other examples, the serving cell inclusion may mean that the RSRP value for the serving cell is reported and the RS index is omitted. For example, the UE may derive the serving cell information based on an indicated TCI state. In such an example, the RSRP value may be reported, and the RS index value may be omitted. In some other examples, the UE may derivethe serving cell information based on an RSRP value of a reference signal (e.g., an SSB or CSI- RS), such as the highest RSRP value among RSRP values obtained by the UE. In some such examples, the RS index of the SSB or CSI-RS and the RSRP value may be included.Alternatively, the reference signal (or signals) corresponding to the TCI State or derived from the reference signal corresponding to the TCI state may be included.

[0162] In some examples, the serving cell inclusion may mean that the RSRP value of the RS index of a reference signal corresponding to the indicated or activated TCI state is reported. In some other examples, the serving cell inclusion may mean that the RS index (and / or RSRP value) for an SSB or CSI-RS, such as the highest quality SSB or CSI-RS among the SSB or CSI- RS s measured by the UE, is included.

[0163] FIG. 12 illustrates an example of an octet in a MAC CE format to which one or more examples disclosed herein may be applied. As illustrated in the example of FIG. 12, the MAC CE format may include an event identifier field (e.g., the event ID field 1210). In some such examples, the event identifier field corresponds to an LTM event triggered reporting configuration identifier (e.g. an N bit value, which can support up to 2*N configuration values). In some such examples, the event identifier field corresponds to or refers at least partly to an CSI reporting configuration identifier. In some such examples, the event identifier field corresponds to or refers at least partly to an LTM reporting configuration identifier. In some such examples, the event identifier field corresponds to or refers at least partly to a reporting configuration identifier. Additionally, or alternatively, the event identifier field may correspond to a codepoint value mapping to the LTM event triggered reporting configuration identifier in ascending order for the LTM reporting configuration identifiers. Additionally, or alternatively, the event identifier field may correspond to an LTM event type (e.g., Event LTM1, Event LTM2, Event LTM3, Event LTM4, or Event LTM 5). Additionally, or alternatively, the event identifier field may correspond to a codepoint value mapping to the LTM event triggered reporting configuration identifier in ascending order for the CSI reporting configuration identifier associated with LTM event triggered reporting. Additionally, or alternatively, the event identifier field may correspond to a CSI reporting configuration identifier associated with LTM event triggered reporting. In other words, the event identifier may correspond to (e.g., be indicative of) one or more types of measurement resource configurations. In some examples, the event ID field 1210 field may occupy N bits. In the example of FIG. 12, the event ID field 1210 occupies 3 bits(e.g., is a 3 bit value). In some examples, by setting the event ID field 1210 to particular value, the UE may indicate the triggering of a reporting event for at least one cell. In some examples, the LTM event type may be indicated in a specific field in the MAC CE. In some examples, the LTM event type (e.g., Event LTM1, Event LTM2, Event LTM3, Event LTM4, or Event LTM 5) may be configured in the reporting configuration (for LTM event triggered reporting) an identifier of an LTM reporting configuration,

[0164] FIG. 13 illustrates an example diagram of encoded candidate cell information in a multi-cell MAC CE format to which one or more examples disclosed herein may be applied. In some examples, as illustrated in the example of FIG. 13, a reporting configuration identifier (e.g., associated with or indicated via an event identifier) may be associated with a measurement resource configuration 1318 (also referred to as a measurement report configuration). The measurement resource configuration 1318 may be an example of an LTM event triggered reporting configuration or a CSI reporting configuration. The measurement resource configuration 1318 may indicate one or more reference signals corresponding to one or more resource indicators (e.g., RS index values). As illustrated in the example of FIG. 13, the measurement resource configuration 1318 may include a first resource set 1314 for a first candidate cell (Cl) and a third resource set 1316 for a third candidate cell (C3). Accordingly, a first resource indicator 1310 (RS index #1) corresponding to the first candidate cell (Cl) may indicate a resource provided in the first resource set 1314 (e.g., SSB-index 1 in the first resource set 1314). Additionally, a second resource indicator 1312 (RS index #1) corresponding to the third candidate cell (C3) may indicate a resource provided in the third resource set 1316 (e.g., SSB-index 1 in the third resource set 1316). In some examples the at least one field (e.g. event identifier field) in the MAC CE as described herein may point to a particular resource / reference signal configuration and the reported RS in the MAC CE are based on the configuration.

[0165] In some examples, as illustrated in FIG. 13, a resource indicator (e.g., the first resource indicator 1310, the second resource indicator 1312) may be an index or identifier of an SSB. In some other examples, the resource indicator may be an index or identifier of a CSI-RS. Additionally, or alternatively, the resource indicator may be a resource index or indicator that points to the SSB index or CSI-RS index / identifier. In some examples, the UE may determine one or more resource index values based on a listing order of reference signals in the measurement resource configuration or based on the index or identifier value. For example, asecond resource index value corresponding to SSB-index 4 configured for the first candidate cell (Cl) may have a value of 2 based on the SSB-index 4 being the second listed reference signal. Alternatively, second resource index value corresponding to SSB-index 4 configured for the first candidate cell (Cl) may have a value of 4 based on the SSB-index 4 having an index value of 4. In some examples, a resource indicator ID space may be configured per PCI / candidate cell (e.g., up to 64 values per resource indicator per candidate cell). In some examples, a RS index field is 6 bits. In some examples the at least one field (e.g. event identifier field) in the MAC CE as described herein may point to a particular resource / reference signal configuration and the reported RS in the MAC CE are based on the configuration.

[0166] FIG. 14 illustrates an example diagram of encoded candidate cell information in a single-cell MAC CE format to which one or more examples disclosed herein may be applied. In some examples, as illustrated in the example of FIG. 14, a reporting configuration identifier (e.g., associated with or indicated via an event identifier) may be associated with a measurement resource configuration 1418. The measurement resource configuration 1418 may be an example of an LTM event triggered reporting configuration or a CSI reporting configuration. The measurement resource configuration 1418 may indicate one or more reference signals corresponding to one or more resource indicators (e.g., RS index values). As illustrated in the example of FIG. 14, the measurement resource configuration 1418 may include a first resource set 1414 for a first candidate cell (Cl) and a third resource set 1416 for a third candidate cell (C3). The MAC CE may include a candidate identifier field 1412 that indicates a candidate cell identifier corresponding to the first candidate cell. Accordingly, based on a first resource indicator 1410 (RS index #1) corresponding to the first candidate cell (Cl), the first resource indicatorl420 may indicate a resource provided in the first resource set 1414 (e.g., SSB-index 1 in the first resource set 1414).

[0167] FIG. 15 illustrates an example of an octet in a MAC CE format to which one or more examples disclosed herein may be applied. As illustrated in the example of FIG. 15, the MAC CE may include a resource set identifier field 1510. In some such examples, the resource set identifier field 1510 indicates a resource set associated with the triggered reporting event (e.g., indicated by the event identifier) or the listed RS index values in the MAC CE. In other words, the resource set identifier field 1510 indicates the set of resources used for measurement and triggering of the event. In some examples, the resource set identifier field 1510 corresponds to aresource set identifier associated with one or more reference signals for candidate cell measurements. In some such examples, the RS index values included in the MAC CE are associated with the resource set identifier. As an illustrative example, the event identifier field may indicate a type of event (e.g. LTM3) and the resource identifier may indicate a set of reference signals that the UE measured for the type of event. In some examples, the resource set used for measurement and triggering of the event may also be indicated by the event identifier field ( as described herein).

[0168] FIG. 16 illustrates an example signaling diagram for LTM to which one or more examples disclosed herein may be applied. The signalling flow diagram of FIG. 16 illustrates operations performed, such as within the system of FIG. 1, by the UE 120 and the network node 110 in accordance with one or more aspects of the present disclosure. One or more operations performed at the UE 120 and the network node 110 may be performed in a different order than the example order shown. Additionally, or alternatively, one or more operations performed at the UE 120 and the network node 110 may be omitted and / or one or more other operations may be added.

[0169] At step 1612, the UE 120 may receive control information (e.g., an LTM configuration and / or a reporting configuration) that is indicative of one or more reference signals, within one or more candidate cells, to monitor for one or more events associated with LTM reporting. In some examples, the control information is indicative of a quantity of measurement values associated with the LTM report (e.g., a number of reference signals or beams for which information is reported). In some such examples, one or more reference signal identifiers associated with the one or more reference signals are included in a MAC CE (e.g., transmitted at step 1620) based on the quantity of measurement values.

[0170] At step 1614, the UE may provide for one or more measurements of the one or more reference signals in accordance with the control information. In other words, the UE may perform one or more measurements on reference signals transmitted via one or more cells (e.g., a serving cell and / or one or more candidate cells).

[0171] At step 1616, the UE may determine one or more events are triggered for at least one cell of the one or more cells. In other words, the UE may identify, based at least in part on the one or more measurements, an occurrence of at least an event of the one or more events for at least a candidate cell of the one or more candidate cells.

[0172] At step 1618, the UE may encode an LTM report (e.g., information configured at the UE to be reported to the network in response to the one or more events being triggered) into a MAC CE format. The MAC CE format may be an example of a MAC CE format illustrated by and described with reference to at least FIGs. 5-15. For example, the MAC CE format may include a single-cell MAC CE format or a multi-cell MAC CE format.

[0173] That is, in some examples, the UE may provide for encoding of the MAC CE in accordance with a multi-cell format. In some such examples, a bit field of the MAC CE may include a candidate cell identifier field, in which the candidate cell identifier field is indicative of the candidate cell based on the candidate cell identifier field being encoded in a bit in a bit position associated with a candidate cell identifier corresponding to the candidate cell. For example, the bit field may be an example of a candidate cell identifier bit field illustrated by and described with reference to at least FIG. 6A.

[0174] In some such examples, the bit position is one of a plurality of bit positions included in the bit field. For example, the MAC CE format may provide for multiple bitfield fields to support multiple cells irrespective of whether the UE is reporting information for one or multiple cells. In some examples, the bit position of the candidate cell identifier is based on a value of the candidate cell identifier. For example, the UE may encode a respective candidate cell identifier for one or multiple cells in ascending order of the candidate cell identifier values. For example, the bit position of the candidate cell identifier may precede at least one other bit position of the plurality of bit positions based on a value of the candidate cell identifier being lower than at least one other value of at least one other candidate cell identifier corresponding to at least one other candidate cell of the one or more candidate cells. In some examples, the MAC CE format may provide for up to N (e.g., up to 8) candidate cells and the UE may report candidate cell information for one or up to N candidate cells.

[0175] In some examples, the MAC CE includes one or more reference signal identifiers associated with a candidate cell (e.g., each candidate cell) of the one or more candidate cells. Additionally, in some examples, a value of a bit in a bit position of the candidate cell identifier field indicates the occurrence of the event for the candidate cell. In some examples, the value of the bit in the bit position further indicates that the MAC CE includes a reference signal identifier corresponding to a reference signal associated with a beam within the candidate cell, and / or a measurement value associated with the reference signal.

[0176] In some other examples, the UE may provide for encoding of the MAC CE in accordance with a single-cell format. In some such examples, the bit field may include a single candidate cell identifier that indicates the occurrence of the event for the candidate cell. For example, the bit field may be an example of a candidate identifier bit field illustrated by and described with reference to at least FIG. 6B.

[0177] In some examples, the UE may be configured to select a format for encoding the MAC CE based on a quantity of candidate cell identifiers associated with reference signals in a reference signal resource set used for evaluating the event (e.g., a resource set indicated via the measurement resource configuration or reporting configuration), a quantity of candidate cells for which at least one occurrence of the event is identified, and / or a quantity of candidate cells indicated via the control information.

[0178] At step 1620, the UE may transmit the LTM report MAC CE to the network node 110. In other words, the UE may transmit a MAC CE to the network based on the occurrence of the event. The MAC CE may include a portion (e.g., some or all) of the information encoded at step 1618. In other words, the MAC CE may include the LTM report (or a portion thereof) based on the occurrence of the event. In some examples, the MAC CE includes one or more bit fields illustrated by and described with reference to at least FIGs. 5-15. For example, the MAC CE may include a bit field that is indicative of at least the candidate cell (e.g., a bit field illustrated by and described with reference to at least FIG. 6A or FIG. 6B).

[0179] In some examples, the MAC CE includes a one or more reference signal identifiers corresponding to the one or more reference signals. In some such examples, a reference signal (e.g., each reference signal) of the one or more reference signals is associated with a respective candidate cell of the one or more candidate cells. In some examples, an order of the one or more reference signal identifiers within the MAC CE are based on a respective value of a candidate cell identifier (e.g., each candidate cell identifier) of one or more candidate cell identifiers corresponding to the one or more candidate cells. For example, one or more reference signal identifiers may be listed in ascending order of the one or more candidate cell identifiers. That is, in some examples, the reference signal identifier corresponding to the lowest candidate cell identifier value (or lowest numbered bit position within the candidate cell identifier field) among the one or more candidate cell identifiers may be listed first (e.g., in the lowest numbered octet of one or more octets carrying the one or more reference signal identifiers). In some such examples,the reference signal identifier corresponding to the highest candidate cell identifier value (or highest numbered bit position within the candidate cell identifier field) among the one or more measurement values may be listed last (e.g., in the highest numbered octet of one or more octets carrying the one or more reference signal identifiers).

[0180] In some examples, the MAC CE includes one or more measurement values corresponding to the one or more reference signal identifiers. In some such examples, a reference signal identifier (e.g., each reference signal identifier) of the one or more reference signal identifiers is associated with a respective measurement value of the one or more measurement values. In some examples, an order of the one or more reference signal identifiers within the MAC CE is based on the one or more measurement values. For example, one or more reference signal identifiers may be listed in ascending order of the measurement values. That is, in some examples, the reference signal identifier corresponding to the lowest measurement value among the one or more measurement values may be listed first (e.g., in the lowest numbered octet of one or more octets carrying the one or more reference signal identifiers). In such an example, the reference signal identifier corresponding to the highest measurement value among the one or more measurement values may be listed last (e.g., in the highest numbered octet of one or more octets carrying the one or more reference signal identifiers).

[0181] In some examples, the reference signal identifier is listed in the MAC CE as a reference signal identifier and measurement value pair as illustrated by and described with reference to at least FIG. 7. In some such examples, a reference signal identifier of the one or more reference signal identifiers may precede at least the respective measurement value associated with the reference signal identifier. For example, the reference signal identifier may be included in a first octet of the MAC CE and the respective measurement value is included in a second octet of the MAC CE, in which the first octet precedes the second octet.

[0182] In some other examples, the reference signal identifier is listed in the MAC CE as a reference signal identifier and measurement value pair as illustrated by and described with reference to at least FIG. 10. In some such examples, the one or more reference signal identifiers precedes the one or more measurement values. For example, the one or more reference signal identifiers may be included in a first one or more octets of the MAC CE and the one or more measurement values is included in a second one or more octets of the MAC CE, in which the first one or more octets precedes the second one or more octets. In some examples, the MAC CEfurther includes an event identifier field (e.g., illustrated by and described with reference to at least FIGs. 6B, 8, and 12) or a resource set identifier field (e.g., illustrated by and described with reference to at least FIG. 15).

[0183] For example, the MAC CE may include an event identifier field indicative of an event identifier. In some such examples, the control information (e.g., received at step 1612) includes a measurement resource configuration (e.g., LTM CSI resource configuration illustrated by and described with reference to at least FIGs. 3, 4, 13 and 14) and the event identifier field (e.g., the event identifier indicated via the event identifier field) corresponds to a reporting configuration associated with the measurement resource configuration. Additionally, or alternatively, in some examples, the event identifier field is indicative of an identifier of an LTM event triggered reporting configuration, an identifier of an LTM reporting configuration, a codepoint value associated with the LTM event triggered reporting configuration, an LTM event type associated with the event, a codepoint value associated with the identifier of the LTM event triggered reporting configuration, an identifier of a CSI reporting configuration associated with LTM event triggered reporting, and / or an identifier of a CSI reporting configuration. In some examples in which the control information includes a measurement resource configuration, the event identifier field corresponds to a reporting configuration associated with the measurement resource configuration.

[0184] In some examples, the MAC CE includes the event identifier field and a candidate cell identifier corresponding to the candidate cell, in which the candidate cell identifier and the event identifier field are included in a same octet of the MAC CE. In some examples, the resource set identifier corresponds to a set of resources used for the one or more measurements, an identifier of a resource set associated with the one or more reference signals, and / or one or more reference signal identifiers included in the MAC CE.

[0185] In some examples, the MAC CE includes serving cell information and candidate cell information. In some such examples, the serving cell information corresponds to a serving cell associated with the apparatus and the candidate cell information corresponds to at least the candidate cell. The serving cell information may be an example of serving cell information illustrated by and described with reference to at least FIG. 11. For example, the serving cell information may precede the candidate cell information. That is, the serving cell information may be included in a first octet of the MAC CE and the candidate cell information may beincluded in at least a second octet of the MAC CE, in which the first octet precedes the second octet (e.g., the first octet is lower in number than the second octet). The serving cell information, in some examples, includes at least one measurement value associated with the serving cell (e.g., an RSRP value for the serving cell). Additionally, in some examples, the candidate cell information may include a reference signal identifier corresponding to a reference signal associated with a beam within the candidate cell and / or a measurement value of at least one measurement performed using the reference signal.

[0186] FIG. 17A and FIG. 17B illustrate examples of an octet in a MAC CE format to which one or more examples disclosed herein may be applied. FIGs. 17A illustrates an example of a single-cell MAC CE format and 17B illustrates an example of a multi-cell MAC CE format. As illustrated in the examples of FIGs. 17A and 17B, information conveyed in the MAC CE may include a reference signal index or resource identifier, the associated cell identifier of the reference signal, a measurement value (e.g., RSRP value), and / or an Event ID

[0187] In some examples, an LI event triggered measurement report (e.g., an LTM report) may carry one or more resource indicators, such as an SSB resource indicator (SSBRI) or a CSI- RS resource indicator (CRI). The resource indicator(s) may correspond to reference signal(s) configured in a measurement configuration. For example, a resource indicator may point to a particular downlink reference signal index or identifier and / or the associated cell. In some examples, more than one resource indicator may be reported. In some examples, the measurement quantity may be a measured RSRP value. In some examples, the measurement quantity may be a measured SINR value.

[0188] In some examples, to provision an LTM Measurement report MAC CE, the UE may be configured to transmit the MAC CE via one or more mechanisms. In some examples, the UE may be configured to transmit an uplink indication ( e.g. a dedicated scheduling request (SR)) to indicate a request by the UE for one or more resources to provision an event triggered report. In some such examples, the UE may transmit the MAC CE in accordance with an uplink grant provided by the network in response to the request. Additionally, or alternatively, the UE may be configured to include the MAC CE in an uplink message transmitted in accordance with an uplink grant provided as part of a random access channel (RACH) procedure (e.g., in MSG3 of a CBRA or MSG A of a 2 step RACH). Additionally, or alternatively, the UE may be configured to include the MAC CE in an uplink message transmitted in accordance with a periodic uplinkgrant (e.g., a configured grant). Additionally, or alternatively, the UE may be configured to include the MAC CE in an uplink message transmitted in accordance with a dynamically scheduled uplink grant and / or an otherwise available uplink grant.

[0189] In some examples, an available uplink grant is not sufficient to carry information (e.g., all information) to be reported to the network. Accordingly, the UE may determine to report less than the configured amount of information in a MAC CE. That is, the UE may be configured to transmit a portion of the configured amount of information in a MAC CE. In other words, the UE may determine that an uplink grant (e.g., a size of the uplink grant) fails to accommodate information to be reported to the network (e.g., all configured report information) and, as such, may determine to encode a portion of the information in a MAC CE. The MAC CE including less than the configured amount of information may be referred to herein as a truncated MAC CE (e.g., a truncated LTM measurement report MAC CE).

[0190] In some examples in which a size of the uplink grant is not sufficient to carry information (e.g., all information) to be reported to the network, the UE may determine which information to encode in the MAC CE. In some instances, however, the UE may lack a mechanism for determining which information to include in the MAC CE (e.g., an LTM measurement report MAC CE).

[0191] Various aspects of the present disclosure provide a framework (e.g., rules) for the UE to determine the information to be included in the LTM measurement report MAC CE. For example, the UE may be configured to provision the LTM report MAC CE in a provided uplink resource allocation. However, the uplink resource allocation may not accommodate some information that the UE is configured to provision in the LTM report MAC CE. In some such examples, in accordance with various aspects of the present disclosure, the UE may include a portion of the information in a particular MAC CE format in which the portion of the information is determined based on one or more rules for inclusion and / or exclusion of RSRP fields associated with reported RS index values. That is, the UE may determine a quantity of RSRP values to include in the MAC CE based on the one or more rules. In some examples, the LTM report MAC CE may be triggered based on an event indicated by an event triggered reporting configuration being triggered for one or more candidate cells.

[0192] FIG. 18 A and FIG. 18B illustrate examples of octets in a MAC CE format to which one or more examples disclosed herein may be applied. As illustrated in the example of FIGs.18 A and 18B, the UE may be configured to omit one or more measurement results from a MAC CE. For example, the UE may be configured to include up to N RS-index+RSRP pairs (e.g., in which N may be an integer configured at the UE, such as 1, 2, or 3) in the MAC CE for at least one candidate cell for which the event has been triggered. In some examples, the RS index or RS index + RSRP pair included in the MAC CE may fulfill one or more event criteria or event triggered reporting criteria.

[0193] As illustrated in the example of FIG. 18 A, the UE may be configured to report a first RS-index (RS-index#l) and an associated RSRP measurement result (RSRP#1), as well as a second RS-index (RS-index#2) and an associated RSRP measurement result (RSRP#2). In some examples, based on an uplink grant failing to accommodate the information that the UE is configured to report, the RSRP measurement results for the listed RS index values for the candidate cells may be omitted from the MAC CE. That is, the fields in the MAC CE that include the RSRP values (or are intended to include the RSRP values) may be omitted from the MAC CE.

[0194] For example, the MAC CE may include a first RSRP field 1810 and a second RSRP field 1812. In such an example, the first RSRP field 1810 and the second RSRP field 1812 may be omitted based on the uplink grant failing to accommodate the information to be reported to the network. As shown in the example of FIG. 18A, the RSRP values may be RSRP values included in RS index + RSRP pairs in which the RS index values and RSRP values are listed in the consecutive octets. In such an example, the fields (e.g., octets) carrying the RSRP values are omitted and the fields (e.g., octets) carrying the RS index values are included. In other words, Oct 1 and Oct 2 are included and the first RSRP field 1810 and the second RSRP field 1812 are omitted.

[0195] As illustrated in the example of FIG. 18B, the RSRP measurement results for the listed RS-index values for the candidate cell(s) may be omitted from the MAC CE. That is fields including the RSRP values may be omitted from the MAC CE. For example, the MAC CE may include a first RSRP field 1814 and a second RSRP field 1816. In such an example, the first RSRP field 1814 and the second RSRP field 1816 may be omitted based on the uplink grant failing to accommodate some information to be reported to the network.

[0196] As shown in the example of FIG. 18B, the RSRP values may be included in RS index+RSRP value pairs in which the RS index values of the index+RSRP value pairs are listedbefore the RSRP values of the index+RSRP value pairs (e.g., the RS-index values are listed first and then the RSRP values are listed after the RS index values). In such an example, fields carrying the RSRP values (e.g., octets intended to carry the RSRP values) are omitted and the fields carrying the RS index values are included, such that the RS-index values are listed in the consecutive fields (e.g., in consecutive octets). That is, Oct 1 and Oct2 are included and the first RSRP field 1814 and the second RSRP field 1816 are omitted.

[0197] In some examples, the RSRP values are included in the MAC CE in the same listing order as the (associated) RS-index values. In some such examples, a quantity of RSRP values included in the MAC CE is based on the size of an available uplink grant. For example, the quantity of RSRP values included in the MAC CE may be determined (e.g., maximized) so that the available uplink grant size is not exceeded. In some examples, J RS-index values are included in the MAC CE. In some such examples, the quantity of RSRP fields may be less than J. In some examples, the quantity of RSRP fields may be zero.

[0198] In some examples, the RSRP measurement result for one RS index value may be included in the MAC CE. For example, the MAC CE may include the RSRP measurement result associated with the first listed RS index value (e.g., the RS-index value reported in the lowest numbered octet among one or more octets including RS-index values). In some such examples, other RSRP values for other RS-index values may be omitted. Additionally, or alternatively, the RS-index with the highest measured RSRP value (e.g., among RSRP values measured by the UE) may be included. For example, both the RS-index and the RSRP value may be included for the RS-index+RSRP pair having the highest RSRP value among RS-index+RSRP pairs for which the RS-index is reported. For example, both the RS-index and the RSRP value may be included for the RS-index+RSRP pair having the highest RSRP value among RS-index+RSRP pairs for which the RS-index is reported, for each cell. This method has the benefit of simple implementation and encoding of a MAC CE.

[0199] In some examples, the MAC CE may include at least one RSRP value for multiple candidate cells for which at least one RS-index is reported. In some such examples, the MAC CE may include the RSRP value for the first listed RS index for each candidate cell for which at least one RS-index is included. For example, the MAC CE may include the RSRP value for the RS-index reported in the lowest numbered octet among one or more octets including RS-index values for each candidate cell for which at least one RS-index is included. In some suchexamples, the RSRP values are included for RS -index values for each candidate cell so that at least one RSRP value is reported for at least one candidate cell. In some examples, the RSRP value is included for the first ‘N’ listed RS index values in the MAC CE for each candidate cell for which the up to N RS -index values are included. This has the benefit of limiting the amount of information for one candidate cell to be able to provision more information on multiple candidate cells.

[0200] In some examples, the UE is configured to report serving cell information (e.g., information for a current SpCell) in the MAC CE. For example, the UE may be configured to report serving cell information for the one or more events such as an LTM3 event. In some such examples, the serving cell information may be excluded (e.g., omitted) from the MAC CE. The excluded serving information may include a serving cell RS-index, a RS-index+RSRP pair, or an RSRP value.

[0201] In some examples in which the UE determines to omit (e.g., not include) the serving cell information, one or more fields (or octets) associated with one or more RSRP values of a serving cell RS-index may be omitted from MAC CE. In some such examples, the serving cell RS-index may correspond to a reference signal included in an indicated TCI state (or otherwise associated with the TCI state), a QCL source RS included in the TCI state (or otherwise associated with the TCI state), a QCL source reference signal of a QCL source included in the TCI state (or otherwise associated with the TCI state), an RS-index associated with a reference signal having a highest measured RSRP value among RSRP values measured for the serving cell, and / or an RS-index used for evaluation of the reporting event.

[0202] In some examples, the available uplink grant size may fail to accommodate fields / octets for both RS-index values and RSRP values. In some such examples, one or more fields / octets including (or intended to include) a field / octet carrying an RSRP value are excluded. The excluded field / octets may be the last field / octets carrying an RSRP value (e.g., the highest numbered octets among octets carrying an RSRP value).

[0203] In some examples, a quantity of RSRP values included in the MAC CE (e.g., a truncated MAC CE) may be zero. Additionally, or alternatively, a quantity of RS identifiers (e.g., RS-index values) included in the MAC CE may be zero.

[0204] In some examples, a quantity of cell identifiers (e.g., candidate cell identifiers and / or serving cell identifiers) included in a truncated MAC CE may be zero.

[0205] In some examples in which the MAC CE is encoded in accordance with a truncated MAC CE format (e.g., a truncated LTM MAC CE format), the truncated MAC CE format may be indicated by a field included in the MAC CE. For example, an LCID (e.g., the header) of the MAC CE may indicate that the MAC CE is a truncated MAC CE and / or may indicate the truncated MAC CE format. In some examples, the truncated MAC CE format may indicate, to the network, that the MAC CE includes a portion (e.g., a part, not the full amount) of information provisioned in the MAC CE by the UE. In other words, the truncated MAC CE format may indicate, to the network, that the MAC CE includes a portion (e.g., a part, not the full amount) of information configured at the UE to be included in an LTM report.

[0206] In some examples, the truncated MAC CE may indicate that some information has been omitted from the MAC CE. In other words, the indication of the omission of information from the MAC CE may indicate that some information is not encoded into the MAC CE. In other words, the truncated MAC CE indicates that the not all the information that the UE is configured to report is encoded into the MAC CE. For example, the truncated MAC CE may be a MAC CE into which the LTM report information is encoded (e.g., the full amount of information) and a portion of the MAC CE is transmitted. Alternatively, the truncated MAC CE may be a MAC CE into which a portion of the LTM report information is encoded.

[0207] In some examples, an RS-index may refer to a reference signal identifier (e.g., an SSB index or CSI-RS index). Additionally, or alternatively, the RS-index may refer to a resource indicator (e.g., an SSBRI or CRI). In some examples, the M-th resource indicator value may indicate the M-th listed reference signal field in a measurement resource set configuration, such as a measurement resource set configuration illustrated by and described with reference to FIGs. 13 and 14. In some examples, an RS-index may be included in a bit field. In some such examples, the bit field may include an RS-index bit field identifying the reference signal, or the bit field may be one of multiple bit fields including an RS-index+RSRP pair.

[0208] In some examples, a reported RS-index or cell, or cell and RS-index+RSRP pair may be determined based on the one or more configured reporting criteria such as an LTMx event. In some such examples, the RSRP value of at least one reference signal of a candidate cell (e.g., at least one beam within a candidate cell used to transmit the at least one reference signal) may be greater than an RSRP value of a reference signal of a serving cell (LTM3).

[0209] FIG. 19 illustrates an example signaling diagram for LTM to which one or more examples disclosed herein may be applied. The signalling flow diagram of FIG. 19 illustrates operations performed, such as within the system of FIG. 1, by the UE 120 and the network node 110 in accordance with one or more aspects of the present disclosure. One or more operations performed at the UE 120 and the network node 110 may be performed in a different order than the example order shown. Additionally, or alternatively, one or more operations performed at the UE 120 and the network node 110 may be omitted and / or one or more other operations may be added.

[0210] At step 1912, the UE 120 may receive control information (e.g., an LTM configuration and / or a reporting configuration) that is indicative of one or more reference signals, within one or more candidate cells, to monitor for one or more events associated with LTM reporting. In some examples, the control information is indicative of a quantity of measurement values associated with the LTM report (e.g., a number of reference signals or beams for which information is reported). In some such examples, one or more reference signal identifiers associated with the one or more reference signals are included in a MAC CE (e.g., transmitted at step 1924) based on the quantity of measurement values.

[0211] At step 1914, the UE may obtain one or more measurement values based on one or more measurements of the one or more reference signals in accordance with the control information. For example, the UE may provide for one or more measurements of the one or more reference signals in accordance with the control information. In other words, the UE may perform one or more measurements on reference signals transmitted via one or more cells (e.g., a serving cell and / or one or more candidate cells).

[0212] At step 1916, the UE may determine one or more events are triggered for at least one cell of the one or more cells. In other words, the UE may identify an occurrence of an event associated with LTM reporting for one or more candidate cells based on one or more measurements associated with the one or more candidate cells (e.g., one or more measurements obtained at 1914).

[0213] At step 1918, the UE may receive control information indicative of an uplink grant for the LTM reporting.

[0214] At step 1920, the UE may determine that a size of the uplink grant fails to accommodate an LTM report for the event.

[0215] At step 1922, the UE may encode a portion of the LTM report (e.g., a portion of information configured at the UE to be reported to the network) into a MAC CE format in response to the one or more events being triggered and based on the determination at 1920. The MAC CE format may be an example of a MAC CE format illustrated by and described with reference to FIGs. 5-15, 17A, 17B, 18A, and / or 18B. For example, the MAC CE format may include a single-cell MAC CE format or a multi-cell MAC CE format.

[0216] In some examples, the portion of the LTM report is encoded in the MAC CE in accordance with a truncated MAC CE format. In some such examples, the MAC CE may include an indication of the truncated MAC CE format.

[0217] At step 1924, the UE may transmit the portion of the LTM report via the MAC CE to the network node 110. In other words, the UE may transmit a truncated MAC CE to the network based on the occurrence of the event and the determination at 1920. The MAC CE may include the portion of the information encoded at step 1922. In some examples, the portion of the LTM report may include a quantity of measurement values associated with the one or more measurements. In some such examples, the quantity of measurement values is based on the size of the uplink grant.

[0218] In some examples, based on the size of the uplink grant, the quantity of measurement values includes at least one measurement value. For example, the portion of the LTM report may include a set of reference signal identifier and measurement value pairs for each of the one or more candidate cells. In such an example, a reference signal identifier and measurement value pair of the set of reference signal identifier and measurement value pairs may include the at least one measurement value. In some examples, a quantity of reference signal identifier and measurement value pairs included in the set of reference signal identifier and measurement value pairs is based at least in part on a threshold. For example, the UE may be configured to report N RS-index+RSRP pairs (e.g., in which N may be an integer configured at the UE, such as 1, 2, or 3) in the MAC CE for at least one candidate cell (e.g., each candidate cell) for which the event has been triggered.

[0219] In some examples, based on the size of the uplink grant, the quantity of measurement values includes zero measurement values. In some such examples, the quantity of measurement values includes zero measurement values based on the portion of the LTM report including zero reference signal identifier and measurement value pairs.

[0220] In some examples, the MAC CE omits a measurement value of a reference signal identifier and measurement value pair based on the size of the uplink grant failing to accommodate the reference signal identifier and measurement value pair (e.g., fails to accommodate both the reference signal identifier and the measurement value). In some such examples, the measurement value is associated with an octet of the MAC CE, and the octet follows at least one other octet of the MAC CE carrying at least one reference signal identifier and measurement value pair. For example, the octet may be a last octet carrying candidate cell information.

[0221] In some examples, the portion of the LTM report includes one or more reference signal identifiers for at least one candidate cell of the one or more candidate cells. In some such examples, the quantity of measurement values is based on one or more measurement values associated with the one or more reference signal identifiers being omitted from the MAC CE. In some examples, the one or more reference signal identifiers are included in one or more consecutive octets of the MAC CE. In some examples, the one or more measurement values are associated with one or more consecutive octets of the MAC CE.

[0222] In some examples, the portion of the LTM report includes a set of reference signal identifiers for at least one candidate cell of the one or more candidate cells. In some such examples, the quantity of measurement values includes a set of measurement values associated with one or more reference signal identifiers of the set of reference signal identifiers. In some examples, the set of reference signal identifiers are included in a first set of one or more consecutive octets of the portion of the MAC CE and the set of measurement values are included in a second set of one or more consecutive octets of the portion of the MAC CE following the first set of one or more consecutive octets. In some examples, an order of measurement values within the second set of one or more consecutive octets is based at least in part on an order of reference signal identifiers within the first set of one or more consecutive octets.

[0223] In some examples, the portion of the LTM report includes one or more reference signal identifiers for at least one candidate cell of the one or more candidate cells. In some such examples, the quantity of measurement values includes a measurement value associated with a reference signal identifier of the one or more reference signal identifiers. In some examples, the portion of the LTM report includes the measurement value based at least in part on a position, within the portion of the MAC CE, of the reference signal identifier relative to at least one otherreference signal identifier of the one or more reference signal identifiers. In some examples, the portion of the LTM report includes the measurement value based at least in part on the measurement value being greater than one or more other measurement values associated with one or more other reference signal identifiers of the one or more reference signal identifiers.

[0224] In some examples, the portion of the LTM report includes, for each candidate cell of the one or more candidate cells, a set of reference signal identifiers and a set of measurement values associated with one or more reference signal identifiers of the set of reference signal identifiers. In some such examples, the quantity of measurement values includes the set of measurement values the quantity of measurement values is based on a threshold. For example, the UE may be configured to include the RSRP value for the first ‘N’ listed RS index values in the MAC CE for each candidate cell for which the up to N RS-index values are included. In some examples, a respective value of each reference signal identifier of the one or more reference signal identifiers is lower than one or more values of one or more other reference signal identifiers in the set of reference signal identifiers.

[0225] In some examples, the MAC CE omits information pertaining to a serving cell associated with the apparatus based at least in part on the size of the uplink grant. In some examples, the MAC CE includes an indication that the LTM report includes a portion of information to be reported for the event. In some examples, the MAC CE includes an indication that the event is pending. In some examples, transmitting the portion of the LTM report via the MAC CE indicates that the event is pending. In some examples, to transmit a remaining portion of the LTM report, the UE may transmit a request for additional uplink resources (e.g., in response to the determination at 1920).

[0226] FIG. 20 illustrates an example flowchart 2000 of a method to which one or more examples disclosed herein may be applied. The method may be computer-implemented. The method may be performed by a UE, such as a UE illustrated by and described with reference to FIGs. 1-19.

[0227] As shown in FIG. 20, the UE at block 2010 identifies an occurrence of an event associated with lower-layer triggered mobility (LTM) reporting for one or more candidate cells based at least in part on one or more measurements associated with the one or more candidate cells.

[0228] As shown in FIG. 20, the UE at block 2012 receives control information indicative of an uplink grant for the LTM reporting.

[0229] As shown in FIG. 20, the UE at block 2014 determines that a size of the uplink grant fails to accommodate an LTM report for the event.

[0230] As shown in FIG. 20, the UE at block 2016 transmits a medium access control (MAC) control element (CE) indicating a portion of the LTM report based at least in part on the determination, wherein the portion of the LTM report includes a quantity of measurement values associated with the one or more measurements, and wherein the quantity of measurement values is based at least in part on the size of the uplink grant.

[0231] FIG. 21 illustrates an example flowchart 2100 of a method to which one or more examples disclosed herein may be applied. The method may be computer-implemented. The method may be performed by a network node (also referred to herein as a network entity), such as a network node illustrated by and described with reference to FIGs. 1-19.

[0232] As shown in FIG. 21, the network node at block 2110 transmits control information indicative of an uplink grant for lower-layer triggered mobility (LTM) reporting associated with an event for one or more candidate cells based at least in part on one or more measurements associated with the one or more candidate cells.

[0233] As shown in FIG. 21, the network node at block 2112 receives a medium access control (MAC) control element (CE) indicating a portion of an LTM report for the event based at least in part on a size of the uplink grant failing to accommodate the LTM report, wherein the portion of the LTM report includes a quantity of measurement values associated with the one or more measurements, and wherein the quantity of measurement values is based at least in part on the size of the uplink grant.

[0234] FIG. 22 shows, by way of example, a block diagram of an apparatus 10. The apparatus 10 comprises, for example, at least one processor 12 and at least one memory 14 storing instructions 15 that, when executed by the at least one processor, cause the apparatus 10 at least to perform the method or methods as disclosed herein, and any of the embodiments thereof. In an example, the at least one memory and the instructions (e.g. a computer program code, software), are configured, with the at least one processor, to cause the apparatus 10 to perform the method or methods as disclosed herein, and any of the embodiments thereof.

[0235] A processor 12 may comprise circuitry, or be constituted as circuitry or circuitries, the circuitry or circuitries being configured to perform phases of methods in accordance with example embodiments described herein. 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, and (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 user equipment, to perform various functions) and (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. This 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.

[0236] The memory 14 may be implemented using any suitable data storage technology. The memory may comprise a database for storing data. The memory 14 may be at least in part external to apparatus 10 but accessible to apparatus 10.

[0237] The instructions 15 may be comprised in a computer readable medium or a non- transitory computer readable medium. A term non-transitory, as used herein, is a limitation of the medium itself (e.g., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g. random access memory, RAM, vs. read only memory, ROM).

[0238] For example, the apparatus 10 is a terminal device, such as the UE of FIGs. 1-19. As another example, the apparatus is comprised in such a terminal device, e.g. as a chipset configured to control the terminal device. The apparatus 10 may be caused or configured to perform at least the method of FIG. 20 and / or any one or more of the embodiments described.

[0239] As another example, the apparatus 10 is a network node, e.g. the network node of FIGs. 1-19. In another embodiment, the apparatus is comprised in such a network node, e.g. as a chipset configured to control the network node. The apparatus 10 may be caused or configured to perform at least the method of FIG. 21 and / or any one or more of the embodiments described.

[0240] The apparatus may comprise one or more entities of any of protocol layers, such as a MAC entity, an RRC entity, an RLC entity, a PDCP entity or a PHY entity. In some embodiments, the entity is configured to perform at least the method of FIG. 20 or FIG. 21, and / or any one or more of the embodiments described.

[0241] The apparatus 10 comprises a radio interface 16. The radio interface 16 may provide the apparatus 10 with communication capabilities. The radio interface 16 may comprise a receiver configured to receive information in accordance with at least one cellular or non-cellular standard. The radio interface 16 may comprise a transmitter configured to transmit information in accordance with at least one cellular or non-cellular standard. The receiver may comprise more than one receiver. The transmitter may comprise more than one transmitter. The radio interface 16 may comprise a transceiver configured to receive and transmit information in accordance with at least one cellular or non-cellular standard. The transceiver may comprise more than one transceiver.

[0242] The apparatus 10 may comprise a user interface 18 comprising, for example, at least one of a keypad, a microphone, a touch display, a display, a speaker, etc. The user interface 18 may be used to control the apparatus by the user. The user interface 18 may be external to the apparatus 10. For example, the apparatus 10 may be connected to another device, such as a computer, either via wireless or wired connection, and the apparatus 10 is controlled by the user via the computer.

[0243] In at least some embodiments, at least some of the processes described herein may be carried out by an apparatus comprising means for carrying out at least some of the described processes. Means for performing method steps as disclosed herein may include software and / or hardware components of the apparatus 10. For example, the at least one processor 12, the memory 14, and the computer program code form means for carrying out the method or methods as disclosed herein, and any of the embodiments thereof. As used herein the term “means” is to be construed in singular form, in other words referring to a single element, or in plural form, in other words referring to a combination of single elements. Therefore, terminology “means for[performing A, B, C]”, is to be interpreted to cover an apparatus in which there is only one means for performing A, B and C, or where there are separate means for performing A, B and C, or partially or fully overlapping means for performing A, B, C. Further, terminology “means for performing A, means for performing B, means for performing C” is to be interpreted to cover an apparatus in which there is only one means for performing A, B and C, or where there are separate means for performing A, B and C, or partially or fully overlapping means for performing A, B, C.

[0244] Even though the present disclosure has been described above with reference to an example according to the accompanying drawings, it is clear that the present disclosure is not restricted thereto but can be modified in several ways within the scope of the appended claims. Therefore, all words and expressions should be interpreted broadly and they are intended to illustrate, not to restrict, the embodiment. It will be obvious to a person skilled in the art that, as technology advances, the inventive concept can be implemented in various ways. Further, it is clear to a person skilled in the art that the described embodiments may, but are not required to, be combined with other embodiments in various ways.

Claims

What 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: identify an occurrence of an event associated with lower-layer triggered mobility (LTM) reporting for one or more candidate cells based at least in part on one or more measurements associated with the one or more candidate cells; receive control information indicative of an uplink grant for the LTM reporting; determine that a size of the uplink grant fails to accommodate an LTM report for the event; and transmit a medium access control (MAC) control element (CE) indicating a portion of the LTM report based at least in part on the determination, wherein the portion of the LTM report includes a quantity of measurement values associated with the one or more measurements, and wherein the quantity of measurement values is based at least in part on the size of the uplink grant.

2. An apparatus according to claim 1, wherein the portion of the LTM report is encoded in the MAC CE in accordance with a truncated MAC CE format, and wherein the MAC CE includes an indication of the truncated MAC CE format.

3. An apparatus according to claim 1 or 2, wherein, based at least in part on the size of the uplink grant, the quantity of measurement values includes at least one measurement value.

4. An apparatus according to claim 3, wherein the portion of the LTM report includes a set of reference signal identifier and measurement value pairs for each of the one or more candidate cells, and wherein a reference signal identifier and measurement value pair of the set of reference signal identifier and measurement value pairs includes the at least one measurement value.

5. An apparatus according to claim 4, wherein a quantity of reference signal identifier and measurement value pairs included in the set of reference signal identifier and measurement value pairs is based at least in part on a threshold.

6. An apparatus according to claim 1, wherein, based at least in part on the size of the uplink grant, the quantity of measurement values includes zero measurement values.

7. An apparatus according to claim 6, wherein the quantity of measurement values includes zero measurement values based at least in part on the portion of the LTM report including zero reference signal identifier and measurement value pairs.

8. An apparatus according to any one of claims 1-7, wherein the MAC CE omits a measurement value of a reference signal identifier and measurement value pair based at least in part on the size of the uplink grant failing to accommodate the reference signal identifier and measurement value pair.

9. An apparatus according to claim 8, wherein the measurement value is associated with an octet of the MAC CE, and wherein the octet follows at least one other octet of the MAC CE carrying at least one reference signal identifier and measurement value pair.

10. An apparatus according to claim 1, wherein the portion of the LTM report includes one or more reference signal identifiers for at least one candidate cell of the one or more candidate cells, and wherein the quantity of measurement values is based at least in part on one or more measurement values associated with the one or more reference signal identifiers being omitted from the MAC CE.

11. An apparatus according to claim 10, wherein the one or more reference signal identifiers are included in one or more consecutive octets of the MAC CE.

12. An apparatus according to claim 10, wherein the one or more measurement values are associated with one or more consecutive octets of the MAC CE.- 56 -13. An apparatus according to claim 1, wherein the portion of the LTM report includes a set of reference signal identifiers for at least one candidate cell of the one or more candidate cells, and wherein the quantity of measurement values includes a set of measurement values associated with one or more reference signal identifiers of the set of reference signal identifiers.

14. An apparatus according to claim 13, wherein the set of reference signal identifiers are included in a first set of one or more consecutive octets of the portion of the MAC CE and the set of measurement values are included in a second set of one or more consecutive octets of the portion of the MAC CE following the first set of one or more consecutive octets.

15. An apparatus according to claim 14, wherein an order of measurement values within the second set of one or more consecutive octets is based at least in part on an order of reference signal identifiers within the first set of one or more consecutive octets.

16. An apparatus according to claim 1, wherein the portion of the LTM report includes one or more reference signal identifiers for at least one candidate cell of the one or more candidate cells, and wherein the quantity of measurement values includes a measurement value associated with a reference signal identifier of the one or more reference signal identifiers.

17. An apparatus according to claim 16, wherein the portion of the LTM report includes the measurement value based at least in part on a position, within the portion of the MAC CE, of the reference signal identifier relative to at least one other reference signal identifier of the one or more reference signal identifiers.

18. An apparatus according to claim 16 or 17, wherein the portion of the LTM report includes the measurement value based at least in part on the measurement value being greater than one or more other measurement values associated with one or more other reference signal identifiers of the one or more reference signal identifiers.

19. An apparatus according to claim 1 , wherein the portion of the LTM report includes, for each candidate cell of the one or more candidate cells, a set of reference signal- 57 -identifiers and a set of measurement values associated with one or more reference signal identifiers of the set of reference signal identifiers, wherein the quantity of measurement values includes the set of measurement values, and wherein the quantity of measurement values is based at least in part on a threshold.

20. An apparatus according to claim 19, wherein a respective value of each reference signal identifier of the one or more reference signal identifiers is lower than one or more values of one or more other reference signal identifiers in the set of reference signal identifiers.

21. An apparatus according to any one of claims 1-20, wherein the MAC CE omits information pertaining to a serving cell associated with the apparatus based at least in part on the size of the uplink grant.

22. An apparatus according to any one of claims 1-21, wherein the MAC CE includes an indication that the LTM report includes a portion of information to be reported for the event.

23. An apparatus according to any one of claims 1-22, wherein the MAC CE includes an indication that the event is pending.

24. An apparatus according to any one of claims 1-22, wherein transmitting the portion of the LTM report via the MAC CE indicates that the event is pending.

25. An apparatus according to any one of claims 1-24, wherein the at least one memory and the instructions, when executed by the at least one processor, cause the apparatus to: transmit a request for additional uplink resources based at least in part on the determination.

26. 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 control information indicative of an uplink grant for lower-layer- 58 -triggered mobility (LTM) reporting associated with an event for one or more candidate cells based at least in part on one or more measurements associated with the one or more candidate cells; and receive a medium access control (MAC) control element (CE) indicating a portion of an LTM report for the event based at least in part on a size of the uplink grant failing to accommodate the LTM report, wherein the portion of the LTM report includes a quantity of measurement values associated with the one or more measurements, and wherein the quantity of measurement values is based at least in part on the size of the uplink grant.

27. An apparatus according to claim 26, wherein the portion of the LTM report is encoded in the MAC CE in accordance with a truncated MAC CE format, and wherein the MAC CE includes an indication of the truncated MAC CE format.

28. An apparatus according to claim 26 or 27, wherein, based at least in part on the size of the uplink grant, the quantity of measurement values includes at least one measurement value.

29. An apparatus according to claim 28, wherein the portion of the LTM report includes a set of reference signal identifier and measurement value pairs for each of the one or more candidate cells, and wherein a reference signal identifier and measurement value pair of the set of reference signal identifier and measurement value pairs includes the at least one measurement value.

30. An apparatus according to claim 29, wherein a quantity of reference signal identifier and measurement value pairs included in the set of reference signal identifier and measurement value pairs is based at least in part on a threshold.

31. An apparatus according to claim 26, wherein, based at least in part on the size of the uplink grant, the quantity of measurement values includes zero measurement values.

32. An apparatus according to claim 31, wherein the quantity of measurement values includes zero measurement values based at least in part on the portion of the LTM report including zero reference signal identifier and measurement value pairs.

33. An apparatus according to any one of claims 26-32, wherein the MAC CE omits a measurement value of a reference signal identifier and measurement value pair based at least in part on the size of the uplink grant failing to accommodate the reference signal identifier and measurement value pair.

34. An apparatus according to claim 33, wherein the measurement value is associated with an octet of the MAC CE, and wherein the octet follows at least one other octet of the MAC CE carrying at least one reference signal identifier and measurement value pair.

35. An apparatus according to claim 26, wherein the portion of the LTM report includes one or more reference signal identifiers for at least one candidate cell of the one or more candidate cells, and wherein the quantity of measurement values is based at least in part on one or more measurement values associated with the one or more reference signal identifiers being omitted from the MAC CE.

36. An apparatus according to claim 35, wherein the one or more reference signal identifiers are included in one or more consecutive octets of the MAC CE.

37. An apparatus according to claim 35, wherein the one or more measurement values are associated with one or more consecutive octets of the MAC CE.

38. An apparatus according to claim 26, wherein the portion of the LTM report includes a set of reference signal identifiers for at least one candidate cell of the one or more candidate cells, and wherein the quantity of measurement values includes a set of measurement values associated with one or more reference signal identifiers of the set of reference signal identifiers.

39. An apparatus according to claim 38, wherein the set of reference signal identifiers are included in a first set of one or more consecutive octets of the portion of the MAC CE andthe set of measurement values are included in a second set of one or more consecutive octets of the portion of the MAC CE following the first set of one or more consecutive octets.

40. An apparatus according to claim 39, wherein an order of measurement values within the second set of one or more consecutive octets is based at least in part on an order of reference signal identifiers within the first set of one or more consecutive octets.

41. An apparatus according to claim 26, wherein the portion of the LTM report includes one or more reference signal identifiers for at least one candidate cell of the one or more candidate cells, and wherein the quantity of measurement values includes a measurement value associated with a reference signal identifier of the one or more reference signal identifiers.

42. An apparatus according to claim 41, wherein the portion of the LTM report includes the measurement value based at least in part on a position, within the portion of the MAC CE, of the reference signal identifier relative to at least one other reference signal identifier of the one or more reference signal identifiers.

43. An apparatus according to claim 41 or 42, wherein the portion of the LTM report includes the measurement value based at least in part on the measurement value being greater than one or more other measurement values associated with one or more other reference signal identifiers of the one or more reference signal identifiers.

44. An apparatus according to claim 26, wherein the portion of the LTM report includes, for each candidate cell of the one or more candidate cells, a set of reference signal identifiers and a set of measurement values associated with one or more reference signal identifiers of the set of reference signal identifiers, wherein the quantity of measurement values includes the set of measurement values, and wherein the quantity of measurement values is based at least in part on a threshold.

45. An apparatus according to claim 44, wherein a respective value of each reference signal identifier of the one or more reference signal identifiers is lower than one or more values of one or more other reference signal identifiers in the set of reference signal identifiers.

46. An apparatus according to any one of claims 1-45, wherein the MAC CE omits information pertaining to a serving cell associated with the apparatus based at least in part on the size of the uplink grant.

47. An apparatus according to any one of claims 1-46, wherein the MAC CE includes an indication that the LTM report includes a portion of information to be reported for the event.

48. An apparatus according to any one of claims 1-47, wherein the MAC CE includes an indication that the event is pending.

49. An apparatus according to any one of claims 1-48, wherein transmitting the portion of the LTM report via the MAC CE indicates that the event is pending.

50. An apparatus according to any one of claims 1-49, wherein the at least one memory and the instructions, when executed by the at least one processor, cause the apparatus to: receive a request for additional uplink resources based at least in part on the determination.

51. A method, comprising: identifying an occurrence of an event associated with lower-layer triggered mobility (LTM) reporting for one or more candidate cells based at least in part on one or more measurements associated with the one or more candidate cells; receiving control information indicative of an uplink grant for the LTM reporting; determining that a size of the uplink grant fails to accommodate an LTM report for the event; and transmitting a medium access control (MAC) control element (CE) indicating a portion of the LTM report based at least in part on the determination, wherein the portion of the LTM report includes a quantity of measurement values associated with the one or more measurements, and wherein the quantity of measurement values is based at least in part on the size of the uplink- 62 -grant.

52. A method, comprising: transmitting control information indicative of an uplink grant for lower-layer triggered mobility (LTM) reporting associated with an event for one or more candidate cells based at least in part on one or more measurements associated with the one or more candidate cells; and receiving a medium access control (MAC) control element (CE) indicating a portion of an LTM report for the event based at least in part on a size of the uplink grant failing to accommodate the LTM report, wherein the portion of the LTM report includes a quantity of measurement values associated with the one or more measurements, and wherein the quantity of measurement values is based at least in part on the size of the uplink grant.

Images