Candidate cell semi-persistent RS activation and deactivation
The introduction of MAC-CE signaling for semi-persistent reference signal activation in 5G NR systems addresses inefficiencies in lower-layer triggered mobility, improving measurement and reporting to enhance mobility management and reduce latency.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- QUALCOMM INC
- Filing Date
- 2025-01-09
- Publication Date
- 2026-07-16
AI Technical Summary
Existing 5G NR technologies lack efficient mechanisms for semi-persistent activation and deactivation of reference signals in lower-layer triggered mobility operations, leading to suboptimal performance in wireless communication systems.
Implementing MAC-CE signaling for activating and deactivating semi-persistent reference signals in candidate cells to support Layer-1/Layer-2 triggered mobility, enhancing measurement and reporting processes for improved mobility management.
Enhances mobility performance by optimizing CSI-RS and SRS operations in candidate cells, facilitating more efficient handover processes and reducing latency in 5G NR networks.
Smart Images

Figure CN2025071448_16072026_PF_FP_ABST
Abstract
Description
CANDIDATE CELL SEMI-PERSISTENT RS ACTIVATION AND DEACTIVATIONTECHNICAL FIELD
[0001] The present disclosure relates generally to communication systems, and more particularly, to a Layer-1 / Layer-2 (L1 / L2) (or lower layer) triggered mobility (LTM) . INTRODUCTION
[0002] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.
[0003] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is 5G New Radio (NR) . 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoT) ) , and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB) , massive machine type communications (mMTC) , and ultra-reliable low latency communications (URLLC) . Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There exists a need for further improvements in 5G NR technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies. BRIEF SUMMARY
[0004] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects. This summary neither identifies key or critical elements of all aspects nor delineates the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.
[0005] In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a wireless device such as a user equipment (UE) that may be configured to receive, while being served by a first cell, a medium access control (MAC) control element (CE) (MAC-CE) indicating an activation of a resource set associated with semi-persistent (SP) reference signals (RS) for a second cell that is a candidate for a lower-layer triggered mobility (LTM) operation, and one of measuring or transmitting, based on the MAC-CE, signals via the resource set associated with the SP RS.
[0006] In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a network node such as a base station that may be configured to serve a UE via a first cell and transmit from the first cell serving the UE, a MAC-CE indicating an activation of a resource set associated with SP RS for a second cell that is a candidate for a LTM operation.
[0007] To the accomplishment of the foregoing and related ends, the one or more aspects may include the features hereinafter fully described and particularly pointed out in the claims. The following description and the drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed.BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network.
[0009] FIG. 2A is a diagram illustrating an example of a first frame, in accordance with various aspects of the present disclosure.
[0010] FIG. 2B is a diagram illustrating an example of downlink (DL) channels within a subframe, in accordance with various aspects of the present disclosure.
[0011] FIG. 2C is a diagram illustrating an example of a second frame, in accordance with various aspects of the present disclosure.
[0012] FIG. 2D is a diagram illustrating an example of uplink (UL) channels within a subframe, in accordance with various aspects of the present disclosure.
[0013] FIG. 3 is a diagram illustrating an example of a base station and user equipment (UE) in an access network.
[0014] FIG. 4 is a diagram illustrating an example configuration in UE mobility, in various aspects.
[0015] FIG. 5 illustrates a signaling design for a MAC-CE that may be used for semi-persistent CSI-RS resource set activation / deactivation for a candidate cell in accordance with some aspects of the disclosure.
[0016] FIG. 6 illustrates a signaling design for a MAC-CE that may be used for semi-persistent zero power CSI-RS resource set activation / deactivation for a candidate cell in accordance with some aspects of the disclosure.
[0017] FIG. 7 illustrates a signaling design for a MAC-CE that may be used for semi-persistent SRS resource set activation / deactivation for a candidate cell in accordance with some aspects of the disclosure.
[0018] FIG. 8 is a call flow diagram illustrating a method of wireless communication in accordance with some aspects of the disclosure.
[0019] FIG. 9 is a flowchart of a method of wireless communication.
[0020] FIG. 10 is a flowchart of a method of wireless communication.
[0021] FIG. 11 is a flowchart of a method of wireless communication.
[0022] FIG. 12 is a flowchart of a method of wireless communication.
[0023] FIG. 13 is a diagram illustrating an example of a hardware implementation for an example apparatus and / or network entity.
[0024] FIG. 14 is a diagram illustrating an example of a hardware implementation for an example network entity.
[0025] FIG. 15 is a diagram illustrating an example configuration in UE mobility, in various aspects.DETAILED DESCRIPTION
[0026] In some aspects of wireless communication, a wireless device (e.g., a UE) may move (or transfer) from a first serving cell to another serving cell in association with a mobility operation and / or mobility procedure. In some aspects, the mobility operation and / or procedure may be associated with mobility between central units (CUs) , distributed units (DUs) , and / or radio units (RUs) .
[0027] Support for inter-CU Layer-1 / Layer-2 (L1 / L2) triggered mobility (LTM) , may be indicated and / or specified in some aspects. The support may prioritize situations (or cases) in which the CU is acting as a master node (MN) when dual connectivity (DC) is not configured. In some aspects, there may be support for (1) the case when NR-DC is configured and the CU is acting as a secondary node (SN) and a master cell group (MCG) is unchanged and / or (2) the case when NR-DC is configured, the CU is acting as the MN and a secondary cell group (SCG) is unchanged or the SCG is released. In some aspects, the case for which LTM is configured in both the MCG and the SCG may be excluded. In some aspects, support for subsequent LTM procedures may be specified and / or indicated to avoid radio resource control (RRC) configuration between cell switches (e.g., based on LTM defined for a particular release of a wireless telecommunications standard, such as a 3GPP 5G NR wireless standard for release 18, e.g., release 18 LTM, among other possible examples) . The support for LTM may be associated with security key handling in coordination with security and privacy aspects of wireless communication. In some aspects, an intra-CU LTM procedure may be considered as a baseline for adding inter-CU support.
[0028] In some aspects, enhancements related to measurements may be associated with supporting LTM. Measurement-related enhancements may be applicable to Intra-CU MCG / SCG LTM and Inter-CU MCG / SCG LTM. Components supporting event triggered L1 measurement reporting may be specified in some aspects. Support for channel state information (CSI) reference signals (RS) (CSI-RS) measurements for LTM procedures, in some aspects, may be specified. In some aspects, support for enabling CSI-RS based beam management, and / or other physical layer operations on candidate cells before LTM may also be specified and / or indicated. Support of conditional LTM, in some aspects, may be specified and / or indicated. In some aspects, UE-evaluated conditions for triggering LTM may be specified and / or identified with the goal of supporting conditional LTM including subsequent LTM. Intra-CU LTM, in some aspects, may be prioritized. Aspects of radio resource management (RRM) may be enhanced or modified, in some aspects, related to the above objectives.
[0029] In some aspects, CSI-RS measurement and CSI reporting operations may be performed before reception of a LTM cell switch command (CSC) MAC-CE. The report (e.g., relating to the CSI-RS measurement on one or more candidate and / or target cell (s) ) may be sent to a serving cell and transferred to the candidate / target cell (s) . In some aspects, CSI-RS measurement may start before reception of the LTM CSC MAC-CE and CSI reporting operation may be performed after reception of LTM CSC MAC-CE, such that the report may be sent directly to a target cell (e.g., a candidate cell identified as a target cell) . CSI-RS measurement and CSI reporting operations, in some aspects, may be performed after reception of the LTM CSC MAC-CE and the report may be sent directly to the target cell.
[0030] Various aspects relate generally to a signaling design for a set one or more activation / deactivation MAC-CE (s) for semi-persistent scheduling of CSI-RS, zero-power (ZP) CSI-RS, and / or sounding reference signals (SRS) associated with candidate special cells (SpCells) , where an SpCell may include a primary cell (PCell) and a primary secondary cell (PSCell) . In some examples, a wireless device may be configured to receive, while being served by a first cell, a MAC-CE indicating an activation of a resource set associated with SP RS for a second cell that is a candidate for a LTM operation, and one of measuring or transmitting, based on the MAC-CE, signals via the resource set associated with the SP RS. In some examples, a network node such as a base station may be configured to serve a UE via a first cell and transmit from the first cell serving the UE, a MAC-CE indicating an activation of a resource set associated with SP RS for a second cell that is a candidate for a LTM operation.
[0031] Particular aspects of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. In some examples, by introducing and / or using one or more activation / deactivation MAC-CE(s) for semi-persistently scheduled CSI-RS, ZP CSI-RS, and / or SRS associated with candidate SpCells, the described techniques can be used to enhance LTM among a set of candidate SpCells.
[0032] The detailed description set forth below in connection with the drawings describes various configurations and does not represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.
[0033] Several aspects of telecommunication systems are presented with reference to various apparatus and methods. These apparatus and methods are described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements” ) . These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.
[0034] By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. When multiple processors are implemented, the multiple processors may perform the functions individually or in combination. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs) , central processing units (CPUs) , application processors, digital signal processors (DSPs) , reduced instruction set computing (RISC) processors, systems on a chip (SoC) , baseband processors, field programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise, shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, or any combination thereof.
[0035] Accordingly, in one or more example aspects, implementations, and / or use cases, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, such computer-readable media can include a random-access memory (RAM) , a read-only memory (ROM) , an electrically erasable programmable ROM (EEPROM) , optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer.
[0036] While aspects, implementations, and / or use cases are described in this application by illustration to some examples, additional or different aspects, implementations and / or use cases may come about in many different arrangements and scenarios. Aspects, implementations, and / or use cases described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, aspects, implementations, and / or use cases may come about via integrated chip implementations and other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / purchasing devices, medical devices, artificial intelligence (AI) -enabled devices, etc. ) . While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described examples may occur. Aspects, implementations, and / or use cases may range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more techniques herein. In some practical settings, devices incorporating described aspects and features may also include additional components and features for implementation and practice of claimed and described aspect. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes (e.g., hardware components including antenna, RF-chains, power amplifiers, modulators, buffer, processor (s) , interleaver, adders / summers, etc. ) . Techniques described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, aggregated or disaggregated components, end-user devices, etc. of varying sizes, shapes, and constitution.
[0037] Deployment of communication systems, such as 5G NR systems, may be arranged in multiple manners with various components or constituent parts. In a 5G NR system, or network, a network node, a network entity, a mobility element of a network, a radio access network (RAN) node, a core network node, a network element, or a network equipment, such as a base station (BS) , or one or more units (or one or more components) performing base station functionality, may be implemented in an aggregated or disaggregated architecture. For example, a BS (such as a Node B (NB) , evolved NB (eNB) , NR BS, 5G NB, access point (AP) , a transmission reception point (TRP) , or a cell, etc. ) may be implemented as an aggregated base station (also known as a standalone BS or a monolithic BS) or a disaggregated base station.
[0038] An aggregated base station may be configured to utilize a radio protocol stack that is physically or logically integrated within a single RAN node. A disaggregated base station may be configured to utilize a protocol stack that is physically or logically distributed among two or more units (such as one or more central or centralized units (CUs) , one or more distributed units (DUs) , or one or more radio units (RUs) ) . In some aspects, a CU may be implemented within a RAN node, and one or more DUs may be co-located with the CU, or alternatively, may be geographically or virtually distributed throughout one or multiple other RAN nodes. The DUs may be implemented to communicate with one or more RUs. Each of the CU, DU and RU can be implemented as virtual units, i.e., a virtual central unit (VCU) , a virtual distributed unit (VDU) , or a virtual radio unit (VRU) .
[0039] Base station operation or network design may consider aggregation characteristics of base station functionality. For example, disaggregated base stations may be utilized in an integrated access backhaul (IAB) network, an open radio access network (O-RAN (such as the network configuration sponsored by the O-RAN Alliance) ) , or a virtualized radio access network (vRAN, also known as a cloud radio access network (C-RAN) ) . Disaggregation may include distributing functionality across two or more units at various physical locations, as well as distributing functionality for at least one unit virtually, which can enable flexibility in network design. The various units of the disaggregated base station, or disaggregated RAN architecture, can be configured for wired or wireless communication with at least one other unit.
[0040] FIG. 1 is a diagram 100 illustrating an example of a wireless communications system and an access network. The illustrated wireless communications system includes a disaggregated base station architecture. The disaggregated base station architecture may include one or more CUs 110 that can communicate directly with a core network 120 via a backhaul link, or indirectly with the core network 120 through one or more disaggregated base station units (such as a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) 125 via an E2 link, or a Non-Real Time (Non-RT) RIC 115 associated with a Service Management and Orchestration (SMO) Framework 105, or both) . A CU 110 may communicate with one or more DUs 130 via respective midhaul links, such as an F1 interface. The DUs 130 may communicate with one or more RUs 140 via respective fronthaul links. The RUs 140 may communicate with respective UEs 104 via one or more radio frequency (RF) access links. In some implementations, the UE 104 may be simultaneously served by multiple RUs 140.
[0041] Each of the units, i.e., the CUs 110, the DUs 130, the RUs 140, as well as the Near-RT RICs 125, the Non-RT RICs 115, and the SMO Framework 105, may include one or more interfaces or be coupled to one or more interfaces configured to receive or to transmit signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units, or an associated processor or controller providing instructions to the communication interfaces of the units, can be configured to communicate with one or more of the other units via the transmission medium. For example, the units can include a wired interface configured to receive or to transmit signals over a wired transmission medium to one or more of the other units. Additionally, the units can include a wireless interface, which may include a receiver, a transmitter, or a transceiver (such as an RF transceiver) , configured to receive or to transmit signals, or both, over a wireless transmission medium to one or more of the other units.
[0042] In some aspects, the CU 110 may host one or more higher layer control functions. Such control functions can include radio resource control (RRC) , packet data convergence protocol (PDCP) , service data adaptation protocol (SDAP) , or the like. Each control function can be implemented with an interface configured to communicate signals with other control functions hosted by the CU 110. The CU 110 may be configured to handle user plane functionality (i.e., Central Unit –User Plane (CU-UP) ) , control plane functionality (i.e., Central Unit –Control Plane (CU-CP) ) , or a combination thereof. In some implementations, the CU 110 can be logically split into one or more CU-UP units and one or more CU-CP units. The CU-UP unit can communicate bidirectionally with the CU-CP unit via an interface, such as an E1 interface when implemented in an O-RAN configuration. The CU 110 can be implemented to communicate with the DU 130, as necessary, for network control and signaling.
[0043] The DU 130 may correspond to a logical unit that includes one or more base station functions to control the operation of one or more RUs 140. In some aspects, the DU 130 may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation, demodulation, or the like) depending, at least in part, on a functional split, such as those defined by 3GPP. In some aspects, the DU 130 may further host one or more low PHY layers. Each layer (or module) can be implemented with an interface configured to communicate signals with other layers (and modules) hosted by the DU 130, or with the control functions hosted by the CU 110.
[0044] Lower-layer functionality can be implemented by one or more RUs 140. In some deployments, an RU 140, controlled by a DU 130, may correspond to a logical node that hosts RF processing functions, or low-PHY layer functions (such as performing fast Fourier transform (FFT) , inverse FFT (iFFT) , digital beamforming, physical random access channel (PRACH) extraction and filtering, or the like) , or both, based at least in part on the functional split, such as a lower layer functional split. In such an architecture, the RU (s) 140 can be implemented to handle over the air (OTA) communication with one or more UEs 104. In some implementations, real-time and non-real-time aspects of control and user plane communication with the RU (s) 140 can be controlled by the corresponding DU 130. In some scenarios, this configuration can enable the DU (s) 130 and the CU 110 to be implemented in a cloud-based RAN architecture, such as a vRAN architecture.
[0045] The SMO Framework 105 may be configured to support RAN deployment and provisioning of non-virtualized and virtualized network elements. For non-virtualized network elements, the SMO Framework 105 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements that may be managed via an operations and maintenance interface (such as an O1 interface) . For virtualized network elements, the SMO Framework 105 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) 190) to perform network element life cycle management (such as to instantiate virtualized network elements) via a cloud computing platform interface (such as an O2 interface) . Such virtualized network elements can include, but are not limited to, CUs 110, DUs 130, RUs 140 and Near-RT RICs 125. In some implementations, the SMO Framework 105 can communicate with a hardware aspect of a 4G RAN, such as an open eNB (O-eNB) 111, via an O1 interface. Additionally, in some implementations, the SMO Framework 105 can communicate directly with one or more RUs 140 via an O1 interface. The SMO Framework 105 also may include a Non-RT RIC 115 configured to support functionality of the SMO Framework 105.
[0046] The Non-RT RIC 115 may be configured to include a logical function that enables non-real-time control and optimization of RAN elements and resources, artificial intelligence (AI) / machine learning (ML) (AI / ML) workflows including model training and updates, or policy-based guidance of applications / features in the Near-RT RIC 125. The Non-RT RIC 115 may be coupled to or communicate with (such as via an A1 interface) the Near-RT RIC 125. The Near-RT RIC 125 may be configured to include a logical function that enables near-real-time control and optimization of RAN elements and resources via data collection and actions over an interface (such as via an E2 interface) connecting one or more CUs 110, one or more DUs 130, or both, as well as an O-eNB, with the Near-RT RIC 125.
[0047] In some implementations, to generate AI / ML models to be deployed in the Near-RT RIC 125, the Non-RT RIC 115 may receive parameters or external enrichment information from external servers. Such information may be utilized by the Near-RT RIC 125 and may be received at the SMO Framework 105 or the Non-RT RIC 115 from non-network data sources or from network functions. In some examples, the Non-RT RIC 115 or the Near-RT RIC 125 may be configured to tune RAN behavior or performance. For example, the Non-RT RIC 115 may monitor long-term trends and patterns for performance and employ AI / ML models to perform corrective actions through the SMO Framework 105 (such as reconfiguration via O1) or via creation of RAN management policies (such as A1 policies) .
[0048] At least one of the CU 110, the DU 130, and the RU 140 may be referred to as a base station 102. Accordingly, a base station 102 may include one or more of the CU 110, the DU 130, and the RU 140 (each component indicated with dotted lines to signify that each component may or may not be included in the base station 102) . The base station 102 provides an access point to the core network 120 for a UE 104. The base station 102 may include macrocells (high power cellular base station) and / or small cells (low power cellular base station) . The small cells include femtocells, picocells, and microcells. A network that includes both small cell and macrocells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs) , which may provide service to a restricted group known as a closed subscriber group (CSG) . The communication links between the RUs 140 and the UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to an RU 140 and / or downlink (DL) (also referred to as forward link) transmissions from an RU 140 to a UE 104. The communication links may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. The communication links may be through one or more carriers. The base station 102 / UEs 104 may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than for UL) . The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell) .
[0049] Certain UEs 104 may communicate with each other using device-to-device (D2D) communication link 158. The D2D communication link 158 may use the DL / UL wireless wide area network (WWAN) spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH) , a physical sidelink discovery channel (PSDCH) , a physical sidelink shared channel (PSSCH) , and a physical sidelink control channel (PSCCH) . D2D communication may be through a variety of wireless D2D communications systems, such as for example, BluetoothTM (Bluetooth is a trademark of the Bluetooth Special Interest Group (SIG) ) , Wi-FiTM (Wi-Fi is a trademark of the Wi-Fi Alliance) based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.
[0050] The wireless communications system may further include a Wi-Fi AP 150 in communication with UEs 104 (also referred to as Wi-Fi stations (STAs) ) via communication link 154, e.g., in a 5 GHz unlicensed frequency spectrum or the like. When communicating in an unlicensed frequency spectrum, the UEs 104 / AP 150 may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.
[0051] The electromagnetic spectrum is often subdivided, based on frequency / wavelength, into various classes, bands, channels, etc. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz –7.125 GHz) and FR2 (24.25 GHz –52.6 GHz) . Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz –300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band.
[0052] The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Recent 5G NR studies have identified an operating band for these mid-band frequencies as frequency range designation FR3 (7.125 GHz –24.25 GHz) . Frequency bands falling within FR3 may inherit FR1 characteristics and / or FR2 characteristics, and thus may effectively extend features of FR1 and / or FR2 into mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operation beyond 52.6 GHz. For example, three higher operating bands have been identified as frequency range designations FR2-2 (52.6 GHz –71 GHz) , FR4 (71 GHz –114.25 GHz) , and FR5 (114.25 GHz –300 GHz) . Each of these higher frequency bands falls within the EHF band.
[0053] With the above aspects in mind, unless specifically stated otherwise, the term “sub-6 GHz” or the like if used herein may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, the term “millimeter wave” or the like if used herein may broadly represent frequencies that may include mid-band frequencies, may be within FR2, FR4, FR2-2, and / or FR5, or may be within the EHF band.
[0054] The base station 102 and the UE 104 may each include a plurality of antennas, such as antenna elements, antenna panels, and / or antenna arrays to facilitate beamforming. The base station 102 may transmit a beamformed signal 182 to the UE 104 in one or more transmit directions. The UE 104 may receive the beamformed signal from the base station 102 in one or more receive directions. The UE 104 may also transmit a beamformed signal 184 to the base station 102 in one or more transmit directions. The base station 102 may receive the beamformed signal from the UE 104 in one or more receive directions. The base station 102 / UE 104 may perform beam training to determine the best receive and transmit directions for each of the base station 102 / UE 104. The transmit and receive directions for the base station 102 may or may not be the same. The transmit and receive directions for the UE 104 may or may not be the same.
[0055] The base station 102 may include and / or be referred to as a gNB, Node B, eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , a TRP, network node, network entity, network equipment, or some other suitable terminology. The base station 102 can be implemented as an integrated access and backhaul (IAB) node, a relay node, a sidelink node, an aggregated (monolithic) base station with a baseband unit (BBU) (including a CU and a DU) and an RU, or as a disaggregated base station including one or more of a CU, a DU, and / or an RU. The set of base stations, which may include disaggregated base stations and / or aggregated base stations, may be referred to as next generation (NG) RAN (NG-RAN) .
[0056] The core network 120 may include an Access and Mobility Management Function (AMF) 161, a Session Management Function (SMF) 162, a User Plane Function (UPF) 163, a Unified Data Management (UDM) 164, one or more location servers 168, and other functional entities. The AMF 161 is the control node that processes the signaling between the UEs 104 and the core network 120. The AMF 161 supports registration management, connection management, mobility management, and other functions. The SMF 162 supports session management and other functions. The UPF 163 supports packet routing, packet forwarding, and other functions. The UDM 164 supports the generation of authentication and key agreement (AKA) credentials, user identification handling, access authorization, and subscription management. The one or more location servers 168 are illustrated as including a Gateway Mobile Location Center (GMLC) 165 and a Location Management Function (LMF) 166. However, generally, the one or more location servers 168 may include one or more location / positioning servers, which may include one or more of the GMLC 165, the LMF 166, a position determination entity (PDE) , a serving mobile location center (SMLC) , a mobile positioning center (MPC) , or the like. The GMLC 165 and the LMF 166 support UE location services. The GMLC 165 provides an interface for clients / applications (e.g., emergency services) for accessing UE positioning information. The LMF 166 receives measurements and assistance information from the NG-RAN and the UE 104 via the AMF 161 to compute the position of the UE 104. The NG-RAN may utilize one or more positioning methods in order to determine the position of the UE 104. Positioning the UE 104 may involve signal measurements, a position estimate, and an optional velocity computation based on the measurements. The signal measurements may be made by the UE 104 and / or the base station 102 serving the UE 104. The signals measured may be based on one or more of a satellite positioning system (SPS) 170 (e.g., one or more of a Global Navigation Satellite System (GNSS) , global position system (GPS) , non-terrestrial network (NTN) , or other satellite position / location system) , LTE signals, wireless local area network (WLAN) signals, Bluetooth signals, a terrestrial beacon system (TBS) , sensor-based information (e.g., barometric pressure sensor, motion sensor) , NR enhanced cell ID (NR E-CID) methods, NR signals (e.g., multi-round trip time (Multi-RTT) , DL angle-of-departure (DL-AoD) , DL time difference of arrival (DL-TDOA) , UL time difference of arrival (UL-TDOA) , and UL angle-of-arrival (UL-AoA) positioning) , and / or other systems / signals / sensors.
[0057] Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA) , a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player) , a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor / actuator, a display, or any other similar functioning device. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc. ) . The UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. In some scenarios, the term UE may also apply to one or more companion devices such as in a device constellation arrangement. One or more of these devices may collectively access the network and / or individually access the network.
[0058] Referring again to FIG. 1, in certain aspects, the UE 104 may have a candidate cell SP RS activation / deactivation MAC-CE (or SP RS A / D MAC-CE) component 198 that may be configured to receive, while being served by a first cell, a MAC-CE indicating an activation of a resource set associated with SP RS for a second cell that is a candidate for a LTM operation, and one of measuring or transmitting, based on the MAC-CE, signals via the resource set associated with the SP RS. In certain aspects, the base station 102 may have a candidate cell SP RS activation / deactivation MAC-CE (SP RS A / D MAC-CE) component 199 that may be configured to serve a UE via a first cell and transmit from the first cell serving the UE, a MAC-CE indicating an activation of a resource set associated with SP RS for a second cell that is a candidate for a LTM operation. Although the following description may be focused on 5G NR, the concepts described herein may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.
[0059] FIG. 2A is a diagram 200 illustrating an example of a first subframe within a 5G NR frame structure. FIG. 2B is a diagram 230 illustrating an example of DL channels within a 5G NR subframe. FIG. 2C is a diagram 250 illustrating an example of a second subframe within a 5G NR frame structure. FIG. 2D is a diagram 280 illustrating an example of UL channels within a 5G NR subframe. The 5G NR frame structure may be frequency division duplexed (FDD) in which for a particular set of subcarriers (carrier system bandwidth) , subframes within the set of subcarriers are dedicated for either DL or UL, or may be time division duplexed (TDD) in which for a particular set of subcarriers (carrier system bandwidth) , subframes within the set of subcarriers are dedicated for both DL and UL. In the examples provided by FIGs. 2A, 2C, the 5G NR frame structure is assumed to be TDD, with subframe 4 being configured with slot format 28 (with mostly DL) , where D is DL, U is UL, and F is flexible for use between DL / UL, and subframe 3 being configured with slot format 1 (with all UL) . While subframes 3, 4 are shown with slot formats 1, 28, respectively, any particular subframe may be configured with any of the various available slot formats 0-61. Slot formats 0, 1 are all DL, UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. UEs are configured with the slot format (dynamically through DL control information (DCI) , or semi-statically / statically through radio resource control (RRC) signaling) through a received slot format indicator (SFI) . Note that the description infra applies also to a 5G NR frame structure that is TDD.
[0060] FIGs. 2A-2D illustrate a frame structure, and the aspects of the present disclosure may be applicable to other wireless communication technologies, which may have a different frame structure and / or different channels. A frame (10 ms) may be divided into 10 equally sized subframes (1 ms) . Each subframe may include one or more time slots. Subframes may also include mini-slots, which may include 7, 4, or 2 symbols. Each slot may include 14 or 12 symbols, depending on whether the cyclic prefix (CP) is normal or extended. For normal CP, each slot may include 14 symbols, and for extended CP, each slot may include 12 symbols. The symbols on DL may be CP orthogonal frequency division multiplexing (OFDM) (CP-OFDM) symbols. The symbols on UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (for power limited scenarios; limited to a single stream transmission) . The number of slots within a subframe is based on the CP and the numerology. The numerology defines the subcarrier spacing (SCS) (see Table 1) . The symbol length / duration may scale with 1 / SCS. Table 1: Numerology, SCS, and CP
[0061] For normal CP (14 symbols / slot) , different numerologies μ 0 to 4 allow for 1, 2, 4, 8, and 16 slots, respectively, per subframe. For extended CP, the numerology 2 allows for 4 slots per subframe. Accordingly, for normal CP and numerology μ, there are 14 symbols / slot and 2μ slots / subframe. The subcarrier spacing may be equal to 2μ* 15 kHz, where μ is the numerology 0 to 4. As such, the numerology μ=0 has a subcarrier spacing of 15 kHz and the numerology μ=4 has a subcarrier spacing of 240 kHz. The symbol length / duration is inversely related to the subcarrier spacing. FIGs. 2A-2D provide an example of normal CP with 14 symbols per slot and numerology μ=2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within a set of frames, there may be one or more different bandwidth parts (BWPs) (see FIG. 2B) that are frequency division multiplexed. Each BWP may have a particular numerology and CP (normal or extended) .
[0062] A resource grid may be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs) ) that extends 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs) . The number of bits carried by each RE depends on the modulation scheme.
[0063] As illustrated in FIG. 2A, some of the REs carry reference (pilot) signals (RS) for the UE.The RS may include demodulation RS (DM-RS) (indicated as R for one particular configuration, but other DM-RS configurations are possible) and channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS) , beam refinement RS (BRRS) , and phase tracking RS (PT-RS) .
[0064] FIG. 2B illustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) (e.g., 1, 2, 4, 8, or 16 CCEs) , each CCE including six RE groups (REGs) , each REG including 12 consecutive REs in an OFDM symbol of an RB. A PDCCH within one BWP may be referred to as a control resource set (CORESET) . A UE is configured to monitor PDCCH candidates in a PDCCH search space (e.g., common search space, UE-specific search space) during PDCCH monitoring occasions on the CORESET, where the PDCCH candidates have different DCI formats and different aggregation levels. Additional BWPs may be located at greater and / or lower frequencies across the channel bandwidth. A primary synchronization signal (PSS) may be within symbol 2 of particular subframes of a frame. The PSS is used by a UE 104 to determine subframe / symbol timing and a physical layer identity. A secondary synchronization signal (SSS) may be within symbol 4 of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI) . Based on the PCI, the UE can determine the locations of the DM-RS. The physical broadcast channel (PBCH) , which carries a master information block (MIB) , may be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block (also referred to as SS block (SSB) ) . The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN) . The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs) , and paging messages.
[0065] As illustrated in FIG. 2C, some of the REs carry DM-RS (indicated as R for one particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE may transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH) . The PUSCH DM-RS may be transmitted in the first one or two symbols of the PUSCH. The PUCCH DM-RS may be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and depending on the particular PUCCH format used. The UE may transmit sounding reference signals (SRS) . The SRS may be transmitted in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL.
[0066] FIG. 2D illustrates an example of various UL channels within a subframe of a frame. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI) , such as scheduling requests, a channel quality indicator (CQI) , a precoding matrix indicator (PMI) , a rank indicator (RI) , and hybrid automatic repeat request (HARQ) acknowledgment (ACK) (HARQ-ACK) feedback (i.e., one or more HARQ ACK bits indicating one or more ACK and / or negative ACK (NACK) ) . The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR) , a power headroom report (PHR) , and / or UCI.
[0067] FIG. 3 is a block diagram of a base station 310 in communication with a UE 350 in an access network. In the DL, Internet protocol (IP) packets may be provided to a controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller / processor 375 provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIBs) , RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release) , inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression / decompression, security (ciphering, deciphering, integrity protection, integrity verification) , and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs) , error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs) , re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs) , demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.
[0068] The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding / decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation / demodulation of physical channels, and MIMO antenna processing. The TX processor 316 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK) , quadrature phase-shift keying (QPSK) , M-phase-shift keying (M-PSK) , M-quadrature amplitude modulation (M-QAM) ) . The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and / or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and / or channel condition feedback transmitted by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318Tx. Each transmitter 318Tx may modulate a radio frequency (RF) carrier with a respective spatial stream for transmission.
[0069] At the UE 350, each receiver 354Rx receives a signal through its respective antenna 352. Each receiver 354Rx recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 may perform spatial processing on the information to recover any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, they may be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT) . The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 310. These soft decisions may be based on channel estimates computed by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station 310 on the physical channel. The data and control signals are then provided to the controller / processor 359, which implements layer 3 and layer 2 functionality.
[0070] The controller / processor 359 can be associated with at least one memory 360 that stores program codes and data. The at least one memory 360 may be referred to as a computer-readable medium. In the UL, the controller / processor 359 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets. The controller / processor 359 is also responsible for error detection using an ACK and / or NACK protocol to support HARQ operations.
[0071] Similar to the functionality described in connection with the DL transmission by the base station 310, the controller / processor 359 provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression / decompression, and security (ciphering, deciphering, integrity protection, integrity verification) ; RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.
[0072] Channel estimates derived by a channel estimator 358 from a reference signal or feedback transmitted by the base station 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antenna 352 via separate transmitters 354Tx. Each transmitter 354Tx may modulate an RF carrier with a respective spatial stream for transmission.
[0073] The UL transmission is processed at the base station 310 in a manner similar to that described in connection with the receiver function at the UE 350. Each receiver 318Rx receives a signal through its respective antenna 320. Each receiver 318Rx recovers information modulated onto an RF carrier and provides the information to a RX processor 370.
[0074] The controller / processor 375 can be associated with at least one memory 376 that stores program codes and data. The at least one memory 376 may be referred to as a computer-readable medium. In the UL, the controller / processor 375 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets. The controller / processor 375 is also responsible for error detection using an ACK and / or NACK protocol to support HARQ operations.
[0075] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 may be configured to perform aspects in connection with the candidate cell SP RS activation / deactivation MAC-CE (SP RS A / D MAC-CE) component 198 of FIG. 1.
[0076] At least one of the TX processor 316, the RX processor 370, and the controller / processor 375 may be configured to perform aspects in connection with the candidate cell SP RS activation / deactivation MAC-CE (SP RS A / D MAC-CE) component 199 of FIG. 1.
[0077] Wireless communication may adopt various mobility scenarios. In some scenarios, a serving cell may be changed through an L3 (L3) handover (e.g., using RRC signaling to indicate the handover) , and the cell evaluation may be relatively slow (on the order of 1 second) . An L3 handover may incur about 80 ms blackout time, without data exchange during this period. A network node may utilize an improved lower layer (e.g., L1 / L2) signaling scheme to change one or more serving cells for a UE in a more efficient manner and with reduced overhead in comparison to L3 based handover approaches. For example, a UE may receive a configuration for a set of cells that are candidates for L1 or L2 inter-cell mobility (e.g., L1 / L2-triggered mobility, or LTM) . The set of cells may include multiple cells, and each cell in the set of cells can be activated or deactivated for data and / or control transfer using L1 or L2 signaling.
[0078] FIG. 15 is a diagram 1500 showing various aspects in connection with LTM. The UE 1512 may be configured with a set of cells or cell groups for LTM (e.g., an LTM candidate set 1506) , e.g., receive an indication for each candidate cell or cell group an associated candidate RRC configuration that could be an RRC reconfiguration message or a cellgroupconfig message along other information elements (IEs) . A candidate cell for the LTM may be a current serving PCell (or PSCell or SpCell) , a current serving SCell, or a current non-serving cell, for example. If the candidate cell for LTM is a current serving SCell, the SCell may be activated or deactivated for LTM before executing LTM to the SCell. For LTM, the UE 1512 may switch to a target cell (or target cell group) . For the latter case, the UE switches to a target PCell and one or more SCells, each of which may be activated or deactivated. Once a cell or cell group is configured for LTM for the UE (e.g., in RRC signaling to the UE) , the UE may receive an indication that one or more of the candidate cells is activated for LTM and / or an indication that one or more of the candidate cells is deactivated for LTM. Once a candidate cell is activated for LTM, the UE may change to being served by that candidate cell based on L1 or L2 signaling, such as a MAC-CE, e.g., rather than L3 signaling. In some aspects, activation or deactivation may be performed for groups of carriers (cells) .
[0079] The configuration and maintenance of multiple candidate cells may allow for a quicker application of configurations for the candidate cells, and the activated set of cells may provide for more dynamic switching among the candidate serving cells (e.g., including an SpCell and SCell) based on L1 or L2 signaling. This can improve service to the UE and reduce overhead for serving cell changes.
[0080] FIG. 15 illustrates a CU 1502 (which may correspond to a component of a base station) may be associated with one or more DUs (e.g., a DU 1504) . The network may configure an LTM candidate set 1506, which may be associated with the DU 1504. As shown, there may be multiple sets of LTM candidate cells configured by the network for the UE 1512. FIG. 15 illustrates an activated candidate cell set 1508 (e.g., that has been configured for the UE for LTM and activated for the UE for LTM) and a deactivated candidate cell set 1510 (e.g., that has been configured for the UE for LTM but has not yet been activated for the UE and / or has been deactivated for the UE) . The LTM candidate set 1506 may also include one or more cells not in the current activated candidate cell set 1508 or the current deactivated candidate cell set 1510. For example, at a given time, the activated candidate cell set 1508 may include a first subset of the LTM configured cell set, and the deactivated candidate cell set 1510 may include a second, non-overlapping subset of the LTM configured cell set. There may remain one or more cells that are in the LTM configured cell set that are not in the first set subset (e.g., activated) or the second subset (e.g., deactivated) . The UE 1512 may use the cells in the activated candidate cell set 1508 for data channel and control channel communications by updating a serving cell in response to L1 / L2 signaling, based on L1 measurement.
[0081] When the serving cell is changed to a target cell selected for switching, the UE 1512 may apply the associated RRC configuration of the target cell. The UE 1512 may perform measurements (e.g., L1 measurements) on the candidate cells, and the target cell may be selected based on these measurements. For example, the UE 1512 may provide a measurement report and receive a cell switch command via L1 / L2 signaling (e.g., a medium access control-control element (MAC-CE) or DCI) . Thus, a set of candidate cells for LTM may be configured for the UE, and a subset of the candidate cells may be activated for the UE. The cells that are not activated, which in some aspects may be referred to as deactivated cells, are cells for which the UE received the LTM configuration, and for which the UE performs measurements but are not used for the transfer of data or control until activated. As the UE 1512 moves, cells from the LTM configured cell set may be deactivated and activated by L1 / L2 signaling based on signal quality (e.g., based on measurements) , loading, or the like. Example measurements may include cell coverage measurements represented by RSRP, and quality represented by Radio Signal Received Quality (RSRQ) , or other measurements that the UE performs on signals from the base station. In some aspects, the measurements may be L1 measurements such as one or more of an RSRP, an RSRQ, a received signal strength indicator (RSSI) , or a signal to noise and interference ratio (SINR) measurement of various signals, such as an SSB, a PSS, an SSS, a broadcast channel (BCH) , a DM-RS, CSI-RS, or the like. Although FIG. 15 illustrates an intra-DU example, serving cell changes through LTM may be used for intra-DU and inter-DU scenarios. Although the example is described in connection with individual cells, the aspects are similarly applicable for cells groups. For example, the UE 1512 may be served by a cell group (e.g., cell group 1 (CG1) ) and be configured with a group of candidate cell groups for LTM (e.g., CG2, CG3, CG4) . The UE 1512 may switch the serving cell (or serving cell group) among the candidate cell groups based on the aspects described for cell changes.
[0082] FIG. 4 is a diagram 400 illustrating an example configuration in UE mobility, in various aspects. In diagram 400, a UE 404 may be initially served by an SpCell 402, while three candidate cells (e.g., a configured candidate SpCell set 420) are available to the UE 404 for mobility: an SpCell 406, an SpCell 408, and an SpCell 410. In some aspects, a set of SP RS (e.g., SP CSI-RS, SP ZP-CSI-RS, or SP SRS) may be activated and / or deactivated by a MAC-CE from the SpCell 402 (e.g., a current serving cell) for one or more of the SpCell 406, the SpCell 408, and / or the SpCell 410. After the UE 404 performs measurements for the SpCells shown, the UE 404 may receive mobility communications from SpCell 402 (e.g., a mobility command) for a change to the UE being served by the SpCell 406, e.g., as a target cell or new serving cell. Such mobility may be Layer-1 / Layer-2 (L1 / L2) triggered mobility (LTM) , in various aspects.
[0083] In response to the LTM indication, the UE 404 then changes to being served by the SpCell 406 and initiates its setup (e.g., configurations for beams, transmission configuration indicator (TCI) , RACH, etc. ) for communications with the SpCell 406.
[0084] SpCells are illustrated in the diagram 400 by way of example and not limitation. Aspects herein contemplate SCell implementations in addition to, or in lieu of, SpCell implementations. Additionally, more or fewer cells may be present in different configurations, in some aspects.
[0085] In some aspects of wireless communication, a wireless device (e.g., a UE) may move (or transfer) from a first serving cell to another serving cell in association with a mobility operation and / or mobility procedure. In some aspects, the mobility operation and / or procedure may be associated with mobility between CUs, DUs, and / or RUs.
[0086] Support for inter-CU LTM, may be indicated and / or specified in some aspects. The support may prioritize situations (or cases) in which the CU is acting as an MN when DC is not configured. In some aspects, there may be support for (1) the case when NR-DC is configured and the CU is acting as an SN and an MCG is unchanged and / or (2) the case when NR-DC is configured, the CU is acting as the MN and a SCG is unchanged or the SCG is released. In some aspects, the case for which LTM is configured in both the MCG and the SCG may be excluded. In some aspects, support for subsequent LTM procedures may be specified and / or indicated to avoid RRC configuration between cell switches (e.g., based on LTM defined for a particular release, such as release 18 LTM associated with the 3GPP 5G NR telecommunication standard, among other examples) . The support for LTM may be associated with security key handling in coordination with security and privacy aspects of wireless communication. In some aspects, an intra-CU LTM procedure may be considered as a baseline for adding inter-CU support.
[0087] In some aspects, enhancements related to measurements may be associated with supporting LTM. Measurement-related enhancements may be applicable to Intra-CU MCG / SCG LTM and Inter-CU MCG / SCG LTM. Components supporting event triggered L1 measurement reporting may be specified in some aspects. Support for CSI-RS measurements for LTM procedures, in some aspects, may be specified. In some aspects, support for enabling CSI-RS based beam management, and / or other physical layer operations on candidate cells before LTM may also be specified and / or indicated. Support of conditional LTM, in some aspects, may be specified and / or indicated between a UE and a network. In some aspects, UE-evaluated conditions for triggering LTM may be specified and / or identified with the goal of supporting conditional LTM including subsequent LTM. Intra-CU LTM, in some aspects, may be prioritized. Aspects of RRM may be enhanced or modified, in some aspects, related to the above objectives.
[0088] In some aspects, CSI-RS measurement and CSI reporting operations may be performed before reception of a LTM CSC MAC-CE. The report (e.g., relating to the CSI-RS measurement on one or more candidate and / or target cell (s) ) may be sent to a serving cell and transferred to the candidate / target cell (s) . In some aspects, CSI-RS measurement may start before reception of the LTM CSC MAC-CE and CSI reporting operation may be performed after reception of LTM CSC MAC-CE, such that the report may be sent directly to a target cell (e.g., a candidate cell identified as a target cell) . CSI-RS measurement and CSI reporting operations, in some aspects, may be performed after reception of the LTM CSC MAC-CE and the report may be sent directly to the target cell.
[0089] Various aspects relate generally to a signaling design for one or more activation / deactivation MAC-CE (s) for semi-persistent scheduling of CSI-RS, ZP CSI-RS, and / or SRS associated with candidate SpCells, where an SpCell may include a PCell and a PSCell. In some examples, a wireless device may be configured to receive, while being served by a first cell, a MAC-CE indicating an activation of a resource set associated with SP RS for a second cell (e.g., rather than the first cell that is serving the UE) that is a candidate for a LTM operation, and one of measuring or transmitting, based on the MAC-CE, signals via the resource set associated with the SP RS. In some examples, a network node such as a base station may be configured to serve a UE via a first cell and transmit from the first cell serving the UE, a MAC-CE indicating an activation of a resource set associated with SP RS for a second cell that is a candidate for a LTM operation. In some aspects, the MAC-CE may indicate a deactivation of a SP CSI-RS resource set. In some aspects, the MAC-CE may be referred to as a MAC-CE for SP CSI-RS resource set activation or deactivation.
[0090] FIG. 5 illustrates a signaling design for a MAC-CE 500 that may be used for semi-persistent CSI-RS resource set activation / deactivation for a candidate cell in accordance with some aspects of the disclosure. In some aspects, the MAC-CE 500 may be transmitted by a current serving cell and received by a UE configured with a set of LTM candidate cells as described in relation to FIG. 4 or FIG. 15. For example, referring to FIG. 4, the MAC-CE 500 may be transmitted by SpCell 402 and may identify (or be associated with) one of the candidate SpCells from the configured candidate SpCell set 420 such as the SpCell 406, the SpCell 408, and / or the SpCell 410.
[0091] The MAC-CE 500, in some aspects, may include a first octet (e.g., Oct 1) that includes a first bit (e.g., A / D 501 or an A / D field) used to indicate whether the MAC-CE 500 is activating (A) or deactivating (D) a set of resources for the SP CSI-RS. In some aspects, a bit value of “0” may indicate one of activation or deactivation and a bit value of “1” may indicate the other alternative (e.g., deactivation or activation, respectively) . For example, the A / D 501 or the A / D field may indicate whether to activate or deactivate indicated SP CSI-RS and CSI-IM resource set (s) and the field may be set to 1 to indicate activation, otherwise it indicates deactivation. The first bit, A / D 501, may be followed in the first octet by a set of reserved bits that may be used for additional signaling and a field and / or a set of bits indicating a candidate cell for which the MAC-CE is activating / deactivating the SP CSI-RS resource set (e.g., the sixth, seventh, and eighth bits making up a single (e.g., 3-bit) candidate cell ID field) . The candidate cell ID field, in some aspects, may indicate the identity of an LTM candidate cell for which the MAC-CE 500 applies. In some aspects, the candidate cell ID may correspond to an ltm-CandidateId minus 1. The length of the candidate cell ID field, in some aspects, may be 3 bits. For example, the MAC-CE 500 may include candidate cell ID 503 (e.g., a candidate cell ID field for an LTM candidate ID) to indicate the identity of the LTM candidate cell (e.g., one of the candidate SpCells of FIG. 4 such as the SpCell 406, the SpCell 408, and / or the SpCell 410) for which the MAC-CE applies (e.g., for which to activate / deactivate a SP CSI-RS resource set) .
[0092] A second octet (e.g., Oct 2) of the MAC-CE 500, in some aspects, may include a reserved bit followed by a bit (e.g., IM 511 or an IM field) used to identify if, or indicate that, (SP) interference measurement (IM) resources for activation / deactivation are included in the MAC-CE 500. For example, the IM 511 or the IM field may indicate the presence of the octet (e.g., Oct 3) containing an SP CSI-IM resource set ID field. In some aspects, if the IM field is set to 1, the octet containing SP CSI-IM resource set ID field is present and if the IM field is set to 0, the octet containing SP CSI-IM resource set ID field is not present (where the selection of the meaning of 0 and 1 may be changed without changing the function of the IM field) . The second octet may further include an SP CSI-RS resource set ID 513 indicating a particular resource set (e.g., a configured, known, and / or preconfigured resource set) associated with SP CSI-RS from the candidate cell (e.g., the LTM candidate cell) identified by the candidate cell ID 503 (e.g., the LTM candidate ID) . For example, the SP CSI-RS resource set ID 513 may be included in a SP CSI-RS resource set field occupying the last six bits of the second octet used to indicate a resource set ID. The resource set ID may be an index of (or an index into) a configured list of non-zero-power (NZP) CSI-RS resource sets (e.g., NZP-CSI-RS-ResourceSet containing SP NZP CSI-RS resources) indicating the SP NZP CSI-RS (or SP CSI-RS) resource set to be activated or deactivated. The length of the SP CSI-RS resource set field, in some aspects, may be 6 bits.
[0093] The MAC-CE 500, in some aspects, may include an SP CSI-IM resource set ID 521 indicating a particular resource set (e.g., a configured, known, and / or preconfigured resource set) for the UE to use for interference measurements associated with the candidate cell identified by the candidate cell ID 503. For example, if the IM 511 (or the IM field) indicates that the MAC-CE 500 includes IM resources for activation / deactivation (the third octet or Oct 3) , the MAC-CE 500 may include the SP CSI-IM resource set ID 521 (e.g., in a SP CSI-IM resource set ID field) . In some aspects, the SP CSI-IM resource set ID field may contain, or the SP CSI-IM resource set ID 521 may be, an index of (or an index into) a configured list of resource sets (e.g., CSI-IM-ResourceSet containing SP CSI-IM resources) indicating the SP CSI-IM resource set to be activated or deactivated based on the MAC-CE 500. The length of the SP CSI-IM resource set ID field, in some aspects, may be 6 bits.
[0094] In subsequent octets (Oct 4 through Oct N+4) , the MAC-CE 500 may include a TCI state ID field (e.g., N+1 Octets including N+1 TCI state ID fields) . The TCI state ID field, in some aspects, may contain a TCI state identifier (e.g., a TCI state ID such as TCI-StateId) of a TCI State which is used as a quasi-colocation (QCL) source for the resource within the SP NZP CSI-RS resource set indicated by the SP CSI-RS resource set ID field (e.g., by the SP CSI-RS resource set ID 513) or for the resource within the SP CSI-IM resource set indicated by the SP CSI-IM resource set ID field (e.g., by the SP CSI-IM resource set ID 521) . In some aspects, TCI state ID0 531 may indicate the TCI State for the first resource within the SP NZP CSI-RS resource set indicated by the SP CSI-RS resource set ID field, a TCI State ID1 (e.g., indicated in a fifth octet, not shown) may indicate the TCI State for the second resource within the SP NZP CSI-RS resource set indicated by the SP CSI-RS resource set ID field, and so on through TCI State IDN, where the TCI State applied to a resource within the SP NZP CSI-RS resource set may be applied to a corresponding CSI-IM resource. The length, in some aspects, of the TCI state ID field may be 7 bits. For example, the MAC-CE 500 may include a set of TCI state ID fields in a corresponding set of octets (e.g., Oct 4 through Oct N+4) indicating a TCI state (e.g., via TCI state ID0 531 through TCI state IDN 541) associated with each resource in the resource set for SP CSI-RS or the resource set for SP CSI-IM indicated in the MAC-CE 500 (via the SP CSI-RS resource set ID 513 and the SP CSI-IM resource set ID 521) . If the A / D field is set to 0, in some aspects, the octets containing TCI State ID field (s) may not be present.
[0095] The MAC-CE 500, in some aspects, may not carry a BWP ID for the SP CSI-RS resource set. In some aspects, a default BWP, such as the first active BWP, in the candidate cell may be applied to the identified SP CSI-RS resource set and / or the SP CSI-IM resource set.
[0096] FIG. 6 illustrates a signaling design for a MAC-CE 600 that may be used for semi-persistent zero power CSI-RS resource set activation / deactivation for a candidate cell in accordance with some aspects of the disclosure. In some aspects, the MAC-CE 600 may be transmitted by a current serving cell and received by a UE configured with a set of LTM candidate cells as described in relation to FIG. 4. For example, referring to FIG. 4, the MAC-CE 600 may be transmitted by SpCell 402 and may identify (or be associated with) one of the candidate SpCells from the configured candidate SpCell set 420 such as the SpCell 406, the SpCell 408, and / or the SpCell 410.
[0097] The MAC-CE 600, in some aspects, may include a first octet (e.g., Oct 1) that includes a first bit (e.g., A / D 601 or an A / D field) used to indicate whether the MAC-CE 600 is activating (A) or deactivating (D) a set of resources for the SP ZP-CSI-RS. In some aspects, a bit value of “0” may indicate one of activation or deactivation and a bit value of “1” may indicate the other alternative (e.g., deactivation or activation, respectively) . For example, the A / D 601 or the A / D field may indicate whether to activate or deactivate indicated SP ZP-CSI-RS resource set and the field may be set to 1 to indicate activation, otherwise it indicates deactivation. The first bit, A / D 601, may be followed in the first octet by a set of reserved bits that may be used for additional signaling and a field and / or a set of bits indicating a candidate cell for which the MAC-CE is activating / deactivating the SP ZP-CSI-RS resource set (e.g., the sixth, seventh, and eighth bits making up a single (3-bit) candidate cell ID field) . The candidate cell ID field, in some aspects, may indicate the identity of an LTM candidate cell for which the MAC-CE 600 applies. In some aspects, the candidate cell ID may correspond to an ltm-CandidateId minus 1. The length of the candidate cell ID field, in some aspects, may be 3 bits. For example, the MAC-CE 600 may include candidate cell ID 603 (e.g., a candidate cell ID field for an LTM candidate ID) to indicate the identity of the LTM candidate cell (e.g., one of the candidate SpCells of FIG. 4 such as the SpCell 406, the SpCell 408, and / or the SpCell 410) for which the MAC-CE applies (e.g., for which to activate / deactivate a SP ZP-CSI-RS resource set) .
[0098] A second octet (e.g., Oct 2) of the MAC-CE 600, in some aspects, may include a set of reserved bits followed by an SP ZP-CSI-RS resource set ID 611 indicating a particular resource set (e.g., a configured, known, and / or preconfigured resource set) associated with SP ZP-CSI-RS from, or associated with, the candidate cell (e.g., the LTM candidate cell) identified by the candidate cell ID 603 (e.g., the LTM candidate ID) . For example, the SP ZP-CSI-RS resource set ID 611 may be included in a SP ZP-CSI-RS resource set field occupying the last four bits of the second octet used to indicate a resource set ID. The resource set ID may be an index of (or an index into) a configured list of resource sets (e.g., sp-ZP-CSI-RS-ResourceSetsToAddModList containing SP ZP CSI-RS resources) indicating the SP ZP CSI-RS resource set to be activated or deactivated. The length of the SP ZP-CSI-RS resource set field, in some aspects, may be 4 bits.
[0099] The MAC-CE 600, in some aspects, may not carry a BWP ID for the SP ZP-CSI-RS resource set. In some aspects, a default BWP, such as the first active BWP, in the candidate cell may be applied to the identified SP ZP-CSI-RS resource set.
[0100] FIG. 7 illustrates a signaling design for a MAC-CE 700 that may be used for semi-persistent SRS resource set activation / deactivation for a candidate cell in accordance with some aspects of the disclosure. In some aspects, the MAC-CE 700 may be transmitted by a current serving cell and received by a UE configured with a set of LTM candidate cells as described in relation to FIG. 4. For example, referring to FIG. 4, the MAC-CE 700 may be transmitted by SpCell 402 and may identify (or be associated with) one of the candidate SpCells from the configured candidate SpCell set 420 such as the SpCell 406, the SpCell 408, and / or the SpCell 410.
[0101] The MAC-CE 700, in some aspects, may include a first octet (e.g., Oct 1) that includes a first bit (e.g., A / D 701 or an A / D field) used to indicate whether the MAC-CE 700 is activating (A) or deactivating (D) a set of resources for the SP SRS. In some aspects, a bit value of “0” may indicate one of activation or deactivation and a bit value of “1” may indicate the other alternative (e.g., deactivation or activation, respectively) . For example, the A / D 701 or the A / D field may indicate whether to activate or deactivate indicated SP SRS resource set (s) and the field may be set to 1 to indicate activation, otherwise it indicates deactivation. The first bit, A / D 701, may be followed in the first octet by a set of reserved bits that may be used for additional signaling and a field and / or a set of bits indicating a candidate cell for which the MAC-CE is activating / deactivating the SP SRS resource set (e.g., the sixth, seventh, and eighth bits making up a single (3-bit) candidate cell ID field) . The candidate cell ID field, in some aspects, may indicate the identity of an LTM candidate cell for which the MAC-CE 700 applies. In some aspects, the candidate cell ID may correspond to an ltm-CandidateId minus 1. The length of the candidate cell ID field, in some aspects, may be 3 bits. For example, the MAC-CE 700 may include candidate cell ID 703 (e.g., a candidate cell ID field for an LTM candidate ID) to indicate the identity of the LTM candidate cell (e.g., one of the candidate SpCells of FIG. 4 such as the SpCell 406, the SpCell 408, and / or the SpCell 410) for which the MAC-CE applies (e.g., for which to activate / deactivate a SP SRS resource set) .
[0102] A second octet (e.g., Oct 2) of the MAC-CE 700, in some aspects, may include a set of reserved bits followed by a set of fields, e.g., a “C” field, a “SUL” field, and a SRS resource set ID field. The “C” field, in some aspects, may be used to indicate whether the octets containing Resource Serving Cell ID field (s) and Resource BWP ID field (s) are present. If the “C” field is set to 1, the octets containing Resource Serving Cell ID field (s) and Resource BWP ID field (s) are present, otherwise they are not present. In some aspects, the “SUL field” may indicate whether the MAC-CE 500 applies to the NUL carrier or SUL carrier configuration. The “SUL” field may be set to 1 to indicate that it applies to the SUL carrier configuration, and it may be set to 0 to indicate that it applies to the NUL carrier configuration.
[0103] The SP SRS resource set ID 713 included in the second octet (Oct 2) , in some aspects, indicates a particular resource set (e.g., a configured, known, and / or preconfigured resource set) associated with SP SRS for the candidate cell (e.g., the LTM candidate cell) identified by the candidate cell ID 703 (e.g., the LTM candidate ID) . For example, the SP SRS resource set ID 713 may be included in a SP SRS resource set field that indicates the SP SRS resource set (e.g., identified by the SP SRS resource set ID 713 such as an SRS-ResourceSetId) which is to be activated or deactivated. The length of the SP SRS resource set field, in some aspects, may be 4 bits and may occupy the last four bits of the second octet (Oct 2) .
[0104] In subsequent octets (Oct 3 through Oct N+2) , the MAC-CE 700 may include a TCI state ID field (e.g., N Octets including N TCI state ID fields) . The TCI state ID field, in some aspects, may contain a TCI state identifier (e.g., a TCI state ID such as TCI-StateId) of a TCI State which is used as a quasi-colocation (QCL) source for the resource within the SP SRS resource set indicated by the SP SRS resource set ID field (e.g., by the SP SRS resource set ID 713) . In some aspects, TCI state ID0 731 may indicate the TCI State for the first resource within the SP SRS resource set indicated by the SP SRS resource set ID field, a TCI State ID1 (e.g., indicated in a fourth octet, not shown) may indicate the TCI State for the second resource within the SP SRS resource set indicated by the SP SRS resource set ID field, and so on through TCI State IDN-1. The length, in some aspects, of the TCI state ID field may be 7 bits. For example, the MAC-CE 700 may include a set of TCI state ID fields in a corresponding set of octets (e.g., Oct 3 through Oct N+2) indicating a TCI state (e.g., via TCI state ID0 721 through TCI state IDN-1 731) associated with each resource in the resource set for SP SRS (e.g., the SP SRS resource set identified by the SP SRS resource set ID 713) . If the A / D field is set to 0, in some aspects, the octets containing TCI State ID field (s) may not be present.
[0105] The MAC-CE 700, in some aspects, may not carry a BWP ID for the SP SRS resource set. In some aspects, a default BWP in the candidate cell may be applied to the identified SP SRS resource set.
[0106] FIG. 8 is a call flow diagram 800 illustrating a method of wireless communication in accordance with some aspects of the disclosure. The method is illustrated in relation to a (first) base station 802 (e.g., as an example of a network device or network node that may include one or more components of a disaggregated base station) acting as a serving cell, or SpCell, for a UE 804 (e.g., as an example of a wireless device) . Additional base stations (e.g., base station 806 or a set of one or more base stations 808) may be identified as candidate serving cells, or SpCells, for a mobility operation (e.g., LTM) and may be associated with candidate cell IDs identifying the different base stations and / or cells. The functions ascribed to the base station 802 (or the other base stations) , in some aspects, may be performed by one or more components of a network entity, a network node, or a network device (a single network entity / node / device or a disaggregated network entity / node / device as described above in relation to FIG. 1) . Similarly, the functions ascribed to the UE 804, in some aspects, may be performed by one or more components of a wireless device supporting communication with a network entity / node / device. Accordingly, references to “transmitting” in the description below may be understood to refer to a first component of a base station (or the UE 804) outputting (or providing) an indication of the content of the transmission to be transmitted by a different component of the base station (or the UE 804) . Similarly, references to “receiving” in the description below may be understood to refer to a first component of the base station (or the UE 804) receiving a transmitted signal and outputting (or providing) the received signal (or information based on the received signal) to a different component of the base station (or the UE 804) .
[0107] The base station 802 may exchange communication 810 with the UE 804 (e.g., in its capacity as a serving cell) . The base station 802 may transmit, and the UE 804 may receive, one or more activation MAC-CEs 812. The one or more activation MAC-CEs 812 may be associated with one or more of an SP CSI-RS, an SP ZP-CSI-RS, or an SP SRS as described in relation to FIGs. 5-7 above. The one or more activation MAC-CEs may identify base station 806 (e.g., via a candidate cell ID 503, 603, or 703) as being associated with one or more activated resource sets. The UE 804 may, at 815, activate the indicated resource sets in association with the indicated candidate cell (e.g., base station 806) based on the one or more activation MAC-CEs 812.
[0108] Activating the resources at 815 based on the one or more activation MAC-CEs 812, in some aspects, may include activating an SP SRS resource set. Based on activating the SP SRS resource set, the UE 804 may transmit, and the base station 806 may receive, (SP) SRS 816. The SRS 816 may be transmitted in resources included in the indicated SP SRS resource set and based on TCI states indicated for the resources as discussed in relation to FIG. 7.
[0109] Activating the resources at 815 based on the one or more activation MAC-CEs 812, in some aspects, may additionally, or alternatively, include activating at least one of a SP ZP-CSI-RS resource set or a SP NZP CSI-RS (or SP CSI-RS) and / or a SP CSI-IM resource set as described in relation to FIGs. 5 and 6 for measurement at the UE 804. Based on activating the at least one of the SP ZP-CSI-RS resource set or the SP NZP CSI-RS (or SP CSI-RS) and / or the SP CSI-IM resource set, the UE 804 may, at 818, measure received signals associated with the activated resources. The received signals measured at 818, in some aspects, may include a SP RS 820 (e.g., a SP CSI-RS) transmitted by the base station 806 (e.g., the candidate cell identified in the one or more activation MAC-CEs 812) , one or more transmissions 822 (e.g., RS or communications to the UE 804 or another UE, not shown) from the base station 802, or transmissions 824 from the one or more base stations 808 (e.g., additional candidate cells not identified in the one or more activation MAC-CEs 812) . Based on the signals measured at 818, the UE 804 may transmit, and the base station 802 and the base station 806 may respectively receive, one or more of a report 826 or a report 828.
[0110] In some aspects, the base station 802 may transmit, and the UE 804 may receive, one or more deactivation MAC-CEs 830. The one or more deactivation MAC-CEs 830 may be associated with one or more of the SP CSI-RS, the SP ZP-CSI-RS, or the SP SRS as described in relation to FIGs. 5-7 above. The one or more deactivation MAC-CEs may identify base station 806 (e.g., via a candidate cell ID 503, 603, or 703) as being associated with the one or more deactivated resource sets. The UE 804 may, at 832, deactivate the indicated resource sets in association with the indicated candidate cell (e.g., base station 806) based on the one or more deactivation MAC-CEs 830.
[0111] FIG. 9 is a flowchart 900 of a method of wireless communication. The method may be performed by a wireless device such as a UE (e.g., the UE 104, 404, 804; the apparatus 1304) . At 902, the UE may receive a MAC-CE indicating an activation of a resource set associated with SP RS for a second cell that is a candidate for a LTM operation. In some aspects, the MAC-CE is received from a first cell while being served by the first cell. For example, 902 may be performed by application processor (s) 1306, cellular baseband processor (s) 1324, transceiver (s) 1322, antenna (s) 1380, and / or candidate cell SP RS activation / deactivation MAC-CE component 198 of FIG. 13. In some aspects, the SP RS may be SP CSI-RS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, a first resource set identifier for the resource set associated with the SP CSI-RS, a second resource set identifier for an additional resource set associated with SP CSI-IM, or one or more TCI state identifiers for one or more TCI states associated with one or more of the SP CSI-RS or the SP CSI-IM. The SP RS, in some aspects, may be SP ZP-CSI-RS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, or a resource set identifier for the resource set associated with the SP ZP-CSI-RS. In some aspects, the SP RS may be SP SRS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, a resource set identifier for the resource set associated with the SP SRS, or one or more TCI state identifiers for one or more TCI states associated with the resource set associated with the SP SRS. For example, referring to FIGs. 5-8, the UE 804 may receive, while being served by base station 802, the one or more MAC-CEs 812 from the base station 802, where the MAC-CEs may be associated with one or more of an SP CSI-RS, an SP ZP-CSI-RS, or an SP SRS as described in relation to FIGs. 5-7.
[0112] At 904, the UE may measure or transmit, based on the MAC-CE, signals via the resource set associated with the SP RS. For example, 904 may be performed by application processor (s) 1306, cellular baseband processor (s) 1324, transceiver (s) 1322, antenna (s) 1380, and / or candidate cell SP RS activation / deactivation MAC-CE component 198 of FIG. 13. In some aspects, the SP RS may be one of SP CSI-RS and the UE may measure the SP CSI-RS from the second cell via the resource set associated with the SP CSI-RS and / or the SP CSI-IM. The SP RS, in some aspects, may be SP ZP-CSI-RS and the UE may measure the signals via the resource set associated with the SP ZP-CSI-RS and the measured signals may include one or more signals not transmitted by the second cell. In some aspects, the SP RS may be SP SRS and the UE may transmit the SP SRS via the resource set associated with the SP SRS. For example, referring to FIG. 8, the UE 804 may, at 815, activate the indicated resource sets in association with the indicated candidate cell (e.g., base station 806) based on the one or more activation MAC-CEs 812.
[0113] In some aspects, the UE may transmit a report regarding one or more of the SP RS measured at the UE via the resource set activated by the MAC-CE. In some aspects, the report may be transmitted to the first cell (e.g., a serving cell) . The report, in some aspects, may be transmitted to the second cell (e.g., the candidate cell for the LTM operation) . For example, referring to FIG. 8, the UE 804 may transmit at least one of report 826 or report 828 based on the measurement at 818.
[0114] The UE, in some aspects, may receive, while being served by the first cell, a second MAC-CE indicating a deactivation of the resource set associated with the SP RS for the second cell. In some aspects, the SP RS may be SP CSI-RS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, a first resource set identifier for the resource set associated with the SP CSI-RS, or a second resource set identifier for an additional resource set associated with SP CSI-IM.The MAC-CE, in some aspects, may not include a TCI state identifier for the one or more of the SP CSI-RS or the SP CSI-IM. The SP RS, in some aspects, may be SP ZP-CSI-RS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, or a resource set identifier for the resource set associated with the SP ZP-CSI-RS. In some aspects, the SP RS may be SP SRS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell or a resource set identifier for the resource set associated with the SP SRS. The MAC-CE, in some aspects, may not include a TCI state identifier for the resource set associated with the SP SRS. For example, referring to FIGs. 5-8, the UE 804 may receive, while being served by base station 802, the one or more MAC-CEs 830 from the base station 802, where the MAC-CEs may be associated with one or more of an SP CSI-RS, an SP ZP-CSI-RS, or an SP SRS as described in relation to FIGs. 5-7.
[0115] In some aspects, the UE may omit one of the measuring or the transmitting, based on the second MAC-CE, of one or more subsequent signals via the resource set associated with the SP RS. In some aspects, the SP RS may be one of SP CSI-RS and the UE may omit measuring the SP CSI-RS from the second cell via the resource set associated with the SP CSI-RS and / or the SP CSI-IM. The SP RS, in some aspects, may be SP ZP-CSI-RS and the UE may omit measuring the signals via the resource set associated with the SP ZP-CSI-RS. In some aspects, the SP RS may be SP SRS and the UE may omit transmitting the SP SRS via the resource set associated with the SP SRS. For example, referring to FIG. 8, the UE 804 may, at 832, deactivate the indicated resource sets in association with the indicated candidate cell (e.g., base station 806) based on the one or more deactivation MAC-CEs 830.
[0116] FIG. 10 is a flowchart 1000 of a method of wireless communication. The method may be performed by a wireless device such as a UE (e.g., the UE 104, 404, 804; the apparatus 1304) . At 1002, the UE may receive a MAC-CE indicating an activation of a resource set associated with SP RS for a second cell that is a candidate for a LTM operation. In some aspects, the MAC-CE is received from a first cell while being served by the first cell. For example, 1002 may be performed by application processor (s) 1306, cellular baseband processor (s) 1324, transceiver (s) 1322, antenna (s) 1380, and / or candidate cell SP RS activation / deactivation MAC-CE component 198 of FIG. 13. In some aspects, the SP RS may be SP CSI-RS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, a first resource set identifier for the resource set associated with the SP CSI-RS, a second resource set identifier for an additional resource set associated with SP CSI-IM, or one or more TCI state identifiers for one or more TCI states associated with one or more of the SP CSI-RS or the SP CSI-IM. The SP RS, in some aspects, may be SP ZP-CSI-RS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, or a resource set identifier for the resource set associated with the SP ZP-CSI-RS. In some aspects, the SP RS may be SP SRS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, a resource set identifier for the resource set associated with the SP SRS, or one or more TCI state identifiers for one or more TCI states associated with the resource set associated with the SP SRS. For example, referring to FIGs. 5-8, the UE 804 may receive, while being served by base station 802, the one or more MAC-CEs 812 from the base station 802, where the MAC-CEs may be associated with one or more of an SP CSI-RS, an SP ZP-CSI-RS, or an SP SRS as described in relation to FIGs. 5-7.
[0117] At 1004, the UE may measure or transmit, based on the MAC-CE, signals via the resource set associated with the SP RS. For example, 1004 may be performed by application processor (s) 1306, cellular baseband processor (s) 1324, transceiver (s) 1322, antenna (s) 1380, and / or candidate cell SP RS activation / deactivation MAC-CE component 198 of FIG. 13. In some aspects, the SP RS may be one of SP CSI-RS and the UE may measure the SP CSI-RS from the second cell via the resource set associated with the SP CSI-RS and / or the SP CSI-IM. The SP RS, in some aspects, may be SP ZP-CSI-RS and the UE may measure the signals via the resource set associated with the SP ZP-CSI-RS and the measured signals may include one or more signals not transmitted by the second cell. In some aspects, the SP RS may be SP SRS and the UE may transmit the SP SRS via the resource set associated with the SP SRS. For example, referring to FIG. 8, the UE 804 may, at 815, activate the indicated resource sets in association with the indicated candidate cell (e.g., base station 806) based on the one or more activation MAC-CEs 812.
[0118] At 1006, the UE may transmit a report regarding one or more of the SP RS measured at the UE via the resource set activated by the MAC-CE. For example, 1006 may be performed by application processor (s) 1306, cellular baseband processor (s) 1324, transceiver (s) 1322, antenna (s) 1380, and / or candidate cell SP RS activation / deactivation MAC-CE component 198 of FIG. 13. In some aspects, the report may be transmitted to the first cell (e.g., a serving cell) . The report, in some aspects, may be transmitted to the second cell (e.g., the candidate cell for the LTM operation) . For example, referring to FIG. 8, the UE 804 may transmit at least one of report 826 or report 828 based on the measurement at 818.
[0119] At 1008, the UE may receive, while being served by the first cell, a second MAC-CE indicating a deactivation of the resource set associated with the SP RS for the second cell. For example, 1008 may be performed by application processor (s) 1306, cellular baseband processor (s) 1324, transceiver (s) 1322, antenna (s) 1380, and / or candidate cell SP RS activation / deactivation MAC-CE component 198 of FIG. 13. In some aspects, the SP RS may be SP CSI-RS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, a first resource set identifier for the resource set associated with the SP CSI-RS, or a second resource set identifier for an additional resource set associated with SP CSI-IM. The MAC-CE, in some aspects, may not include a TCI state identifier for the one or more of the SP CSI-RS or the SP CSI-IM. The SP RS, in some aspects, may be SP ZP-CSI-RS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, or a resource set identifier for the resource set associated with the SP ZP-CSI-RS. In some aspects, the SP RS may be SP SRS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell or a resource set identifier for the resource set associated with the SP SRS. The MAC-CE, in some aspects, may not include a TCI state identifier for the resource set associated with the SP SRS. For example, referring to FIGs. 5-8, the UE 804 may receive, while being served by base station 802, the one or more MAC-CEs 830 from the base station 802, where the MAC-CEs may be associated with one or more of an SP CSI-RS, an SP ZP-CSI-RS, or an SP SRS as described in relation to FIGs. 5-7.
[0120] At 1010, the UE may omit, based on the second MAC-CE, one of measurement or transmission of one or more subsequent signals via the resource set associated with the SP RS. For example, 1010 may be performed by application processor (s) 1306, cellular baseband processor (s) 1324, transceiver (s) 1322, antenna (s) 1380, and / or candidate cell SP RS activation / deactivation MAC-CE component 198 of FIG. 13. In some aspects, the SP RS may be one of SP CSI-RS and the UE may omit measuring (e.g., measurement of) the SP CSI-RS from the second cell via the resource set associated with the SP CSI-RS and / or the SP CSI-IM. The SP RS, in some aspects, may be SP ZP-CSI-RS and the UE may omit measuring (e.g., measurement of) the signals via the resource set associated with the SP ZP-CSI-RS. In some aspects, the SP RS may be SP SRS and the UE may omit transmitting (e.g., transmission of) the SP SRS via the resource set associated with the SP SRS. For example, referring to FIG. 8, the UE 804 may, at 832, deactivate the indicated resource sets in association with the indicated candidate cell (e.g., base station 806) based on the one or more deactivation MAC-CEs 830.
[0121] FIG. 11 is a flowchart 1100 of a method of wireless communication. The method may be performed by a network node such as a base station (e.g., the base station 102, 802; the SpCell 402; the network entity 1302, 1402) . At 1102, the network node may serve a UE via a first cell. For example, 1102 may be performed by CU processor (s) 1412, DU processor (s) 1432, RU processor (s) 1442, transceiver (s) 1446, antenna (s) 1480, and / or candidate cell SP RS activation / deactivation MAC-CE component 199 of FIG. 14. For example, referring to FIG. 8, the base station 802 may exchange communication 810 with the UE 804 (e.g., in its capacity as a serving cell) .
[0122] At 1104, the network node may transmit a MAC-CE indicating an activation of a resource set associated with SP RS for a second cell that is a candidate for a LTM operation. In some aspects, the MAC-CE may be transmitted from the first cell serving the UE. The MAC-CE, in some aspects, may be transmitted to the UE. For example, 1104 may be performed by application processor (s) 1306, cellular baseband processor (s) 1324, transceiver (s) 1322, antenna (s) 1380, and / or candidate cell SP RS activation / deactivation MAC-CE component 198 of FIG. 13. In some aspects, the SP RS may be SP CSI-RS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, a first resource set identifier for the resource set associated with the SP CSI-RS, a second resource set identifier for an additional resource set associated with SP CSI-IM, or one or more TCI state identifiers for one or more TCI states associated with one or more of the SP CSI-RS or the SP CSI-IM. The SP RS, in some aspects, may be SP ZP-CSI-RS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, or a resource set identifier for the resource set associated with the SP ZP-CSI-RS. In some aspects, the SP RS may be SP SRS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, a resource set identifier for the resource set associated with the SP SRS, or one or more TCI state identifiers for one or more TCI states associated with the resource set associated with the SP SRS. For example, referring to FIGs. 5-8, the base station 802 may, while serving the UE 804, transmit, and the UE 804 may receive, the one or more MAC-CEs 812, where the MAC-CEs may be associated with one or more of an SP CSI-RS, an SP ZP-CSI-RS, or an SP SRS as described in relation to FIGs. 5-7.
[0123] In some aspects, the network node may receive a report regarding one or more of the SP RS measured at the UE via the resource set activated by the MAC-CE. In some aspects, the SP RS may be one of SP CSI-RS and the report may be related to the SP CSI-RS from the second cell via the resource set associated with the SP CSI-RS and / or the SP CSI-IM. The SP RS, in some aspects, may be SP ZP-CSI-RS and the report may be related to the resource set associated with the SP ZP-CSI-RS and the measured signals may include one or more signals not transmitted by the second cell. In some aspects, the report may be provided to the second cell (e.g., the candidate cell for the LTM operation) . For example, referring to FIG. 8, the base station may receive report 826 based on the measurement at 818.
[0124] The network node, in some aspects, may transmit from the first cell serving the UE, a second MAC-CE indicating a deactivation of the resource set associated with the SP RS for the second cell. In some aspects, the SP RS may be SP CSI-RS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, a first resource set identifier for the resource set associated with the SP CSI-RS, or a second resource set identifier for an additional resource set associated with SP CSI-IM. The MAC-CE, in some aspects, may not include a TCI state identifier for the one or more of the SP CSI-RS or the SP CSI-IM. The SP RS, in some aspects, may be SP ZP-CSI-RS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, or a resource set identifier for the resource set associated with the SP ZP-CSI-RS. In some aspects, the SP RS may be SP SRS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell or a resource set identifier for the resource set associated with the SP SRS. The MAC-CE, in some aspects, may not include a TCI state identifier for the resource set associated with the SP SRS. For example, referring to FIGs. 5-8, the base station 802 may, while serving the UE 804, transmit, and the UE 804 may receive, the one or more MAC-CEs 830, where the MAC-CEs may be associated with one or more of an SP CSI-RS, an SP ZP-CSI-RS, or an SP SRS as described in relation to FIGs. 5-7.
[0125] FIG. 12 is a flowchart 1200 of a method of wireless communication. The method may be performed by a network node such as a base station (e.g., the base station 102, 802; the SpCell 402; the network entity 1302, 1402) . At 1202, the network node may serve a UE via a first cell. For example, 1202 may be performed by CU processor (s) 1412, DU processor (s) 1432, RU processor (s) 1442, transceiver (s) 1446, antenna (s) 1480, and / or candidate cell SP RS activation / deactivation MAC-CE component 199 of FIG. 14. For example, referring to FIG. 8, the base station 802 may exchange communication 810 with the UE 804 (e.g., in its capacity as a serving cell) .
[0126] At 1204, the network node may transmit a MAC-CE indicating an activation of a resource set associated with SP RS for a second cell that is a candidate for a LTM operation. In some aspects, the MAC-CE may be transmitted from the first cell serving the UE. The MAC-CE, in some aspects, may be transmitted to the UE. For example, 1204 may be performed by application processor (s) 1306, cellular baseband processor (s) 1324, transceiver (s) 1322, antenna (s) 1380, and / or candidate cell SP RS activation / deactivation MAC-CE component 198 of FIG. 13. In some aspects, the SP RS may be SP CSI-RS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, a first resource set identifier for the resource set associated with the SP CSI-RS, a second resource set identifier for an additional resource set associated with SP CSI-IM, or one or more TCI state identifiers for one or more TCI states associated with one or more of the SP CSI-RS or the SP CSI-IM. The SP RS, in some aspects, may be SP ZP-CSI-RS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, or a resource set identifier for the resource set associated with the SP ZP-CSI-RS. In some aspects, the SP RS may be SP SRS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, a resource set identifier for the resource set associated with the SP SRS, or one or more TCI state identifiers for one or more TCI states associated with the resource set associated with the SP SRS. For example, referring to FIGs. 5-8, the base station 802 may, while serving the UE 804, transmit, and the UE 804 may receive, the one or more MAC-CEs 812, where the MAC-CEs may be associated with one or more of an SP CSI-RS, an SP ZP-CSI-RS, or an SP SRS as described in relation to FIGs. 5-7.
[0127] At 1206, the network node may receive a report regarding one or more of the SP RS measured at the UE via the resource set activated by the MAC-CE. For example, 1206 may be performed by application processor (s) 1306, cellular baseband processor (s) 1324, transceiver (s) 1322, antenna (s) 1380, and / or candidate cell SP RS activation / deactivation MAC-CE component 198 of FIG. 13. In some aspects, the SP RS may be one of SP CSI-RS and the report may be related to the SP CSI-RS from the second cell via the resource set associated with the SP CSI-RS and / or the SP CSI-IM.The SP RS, in some aspects, may be SP ZP-CSI-RS and the report may be related to the resource set associated with the SP ZP-CSI-RS and the measured signals may include one or more signals not transmitted by the second cell. In some aspects, the report may be provided to the second cell (e.g., the candidate cell for the LTM operation) . For example, referring to FIG. 8, the base station may receive report 826 based on the measurement at 818.
[0128] At 1208, the network node may transmit from the first cell serving the UE, a second MAC-CE indicating a deactivation of the resource set associated with the SP RS for the second cell. For example, 1208 may be performed by application processor (s) 1306, cellular baseband processor (s) 1324, transceiver (s) 1322, antenna (s) 1380, and / or candidate cell SP RS activation / deactivation MAC-CE component 198 of FIG. 13. In some aspects, the SP RS may be SP CSI-RS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, a first resource set identifier for the resource set associated with the SP CSI-RS, or a second resource set identifier for an additional resource set associated with SP CSI-IM. The MAC-CE, in some aspects, may not include a TCI state identifier for the one or more of the SP CSI-RS or the SP CSI-IM. The SP RS, in some aspects, may be SP ZP-CSI-RS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell, or a resource set identifier for the resource set associated with the SP ZP-CSI-RS. In some aspects, the SP RS may be SP SRS and the MAC-CE may include an indication of one or more of a candidate cell identifier of the second cell or a resource set identifier for the resource set associated with the SP SRS. The MAC-CE, in some aspects, may not include a TCI state identifier for the resource set associated with the SP SRS. For example, referring to FIGs. 5-8, the base station 802 may, while serving the UE 804, transmit, and the UE 804 may receive, the one or more MAC-CEs 830, where the MAC-CEs may be associated with one or more of an SP CSI-RS, an SP ZP-CSI-RS, or an SP SRS as described in relation to FIGs. 5-7.
[0129] FIG. 13 is a diagram 1300 illustrating an example of a hardware implementation for an apparatus 1304. The apparatus 1304 may be a UE, a component of a UE, or may implement UE functionality. In some aspects, the apparatus 1304 may include at least one cellular baseband processor 1324 (also referred to as a modem) coupled to one or more transceivers 1322 (e.g., cellular RF transceiver) . The cellular baseband processor (s) 1324 may include at least one on-chip memory 1324'. In some aspects, the apparatus 1304 may further include one or more subscriber identity modules (SIM) cards 1320 and at least one application processor 1306 coupled to a secure digital (SD) card 1308 and a screen 1310. The application processor (s) 1306 may include on-chip memory 1306'. In some aspects, the apparatus 1304 may further include a Bluetooth module 1312, a WLAN module 1314, an SP module 1316 (e.g., GNSS module) , one or more sensor modules 1318 (e.g., barometric pressure sensor / altimeter; motion sensor such as inertial measurement unit (IMU) , gyroscope, and / or accelerometer (s) ; light detection and ranging (LIDAR) , radio assisted detection and ranging (RADAR) , sound navigation and ranging (SONAR) , magnetometer, audio and / or other technologies used for positioning) , additional memory modules 1326, a power supply 1330, and / or a camera 1332. The Bluetooth module 1312, the WLAN module 1314, and the SP module 1316 may include an on-chip transceiver (TRX) (or in some cases, just a receiver (RX) ) . The Bluetooth module 1312, the WLAN module 1314, and the SP module 1316 may include their own dedicated antennas and / or utilize one or more antennas 1380 for communication. The cellular baseband processor (s) 1324 communicates through the transceiver (s) 1322 via the one or more antennas 1380 with the UE 104 and / or with an RU associated with a network entity 1302. The cellular baseband processor (s) 1324 and the application processor (s) 1306 may each include a computer-readable medium / memory 1324', 1306', respectively. The additional memory modules 1326 may also be considered a computer-readable medium / memory. Each computer-readable medium / memory 1324', 1306', 1326 may be non-transitory. The cellular baseband processor (s) 1324 and the application processor (s) 1306 are each responsible for general processing, including the execution of software stored on the computer-readable medium / memory. The software, when executed by the cellular baseband processor (s) 1324 / application processor (s) 1306, causes the cellular baseband processor (s) 1324 / application processor (s) 1306 to perform the various functions described supra. The cellular baseband processor (s) 1324 and the application processor (s) 1306 are configured to perform the various functions described supra based at least in part of the information stored in the memory. That is, the cellular baseband processor (s) 1324 and the application processor (s) 1306 may be configured to perform a first subset of the various functions described supra without information stored in the memory and may be configured to perform a second subset of the various functions described supra based on the information stored in the memory. The computer-readable medium / memory may also be used for storing data that is manipulated by the cellular baseband processor (s) 1324 / application processor (s) 1306 when executing software. The cellular baseband processor (s) 1324 / application processor (s) 1306 may be a component of the UE 350 and may include the at least one memory 360 and / or at least one of the TX processor 368, the RX processor 356, and the controller / processor 359. In one configuration, the apparatus 1304 may be at least one processor chip (modem and / or application) and include just the cellular baseband processor (s) 1324 and / or the application processor (s) 1306, and in another configuration, the apparatus 1304 may be the entire UE (e.g., see UE 350 of FIG. 3) and include the additional modules of the apparatus 1304.
[0130] As discussed supra, the candidate cell SP RS activation / deactivation MAC-CE component 198 may be configured to receive, while being served by a first cell, a MAC-CE indicating an activation of a resource set associated with SP RS for a second cell that is a candidate for a LTM operation, and one of measuring or transmitting, based on the MAC-CE, signals via the resource set associated with the SP RS. The candidate cell SP RS activation / deactivation MAC-CE component 198 may be within the cellular baseband processor (s) 1324, the application processor (s) 1306, or both the cellular baseband processor (s) 1324 and the application processor (s) 1306. The candidate cell SP RS activation / deactivation MAC-CE component 198 may be one or more hardware components specifically configured to carry out the stated processes / algorithm, implemented by one or more processors configured to perform the stated processes / algorithm, stored within a computer-readable medium for implementation by one or more processors, or some combination thereof. When multiple processors are implemented, the multiple processors may perform the stated processes / algorithm individually or in combination. As shown, the apparatus 1304 may include a variety of components configured for various functions. In one configuration, the apparatus 1304, and in particular the cellular baseband processor (s) 1324 and / or the application processor (s) 1306, may include means for receiving, while being served by a first cell, a medium access control (MAC) control element (CE) (MAC-CE) indicating an activation of a resource set associated with semi-persistent (SP) reference signals (RS) for a second cell that is a candidate for a lower-layer triggered mobility (LTM) operation. The apparatus 1304, and in particular the cellular baseband processor (s) 1324 and / or the application processor (s) 1306, may include means for one of measuring or transmitting, based on the MAC-CE, signals via the resource set associated with the SP RS. The apparatus 1304, and in particular the cellular baseband processor (s) 1324 and / or the application processor (s) 1306, may include means for transmitting a report regarding one or more of the SP RS measured at the UE via the resource set activated by the MAC-CE. The apparatus 1304, and in particular the cellular baseband processor (s) 1324 and / or the application processor (s) 1306, may include means for receiving, while being served by the first cell, a second MAC-CE indicating a deactivation of the resource set associated with the SP RS for the second cell. The apparatus 1304, and in particular the cellular baseband processor (s) 1324 and / or the application processor (s) 1306, may include means for omitting one of the measuring or the transmitting, based on the second MAC-CE, of one or more subsequent signals via the resource set associated with the SP RS. The apparatus 1304 may further include means for performing any of the aspects described in connection with the flowcharts in FIGs. 9 or 10, and / or performed by the UE in the communication flow of FIG. 8. The means may be the candidate cell SP RS activation / deactivation MAC-CE component 198 of the apparatus 1304 configured to perform the functions recited by the means. As described supra, the apparatus 1304 may include the TX processor 368, the RX processor 356, and the controller / processor 359. As such, in one configuration, the means may be the TX processor 368, the RX processor 356, and / or the controller / processor 359 configured to perform the functions recited by the means.
[0131] FIG. 14 is a diagram 1400 illustrating an example of a hardware implementation for a network entity 1402. The network entity 1402 may be a BS, a component of a BS, or may implement BS functionality. The network entity 1402 may include at least one of a CU 1410, a DU 1430, or an RU 1440. For example, depending on the layer functionality handled by the candidate cell SP RS activation / deactivation MAC-CE component 199, the network entity 1402 may include the CU 1410; both the CU 1410 and the DU 1430; each of the CU 1410, the DU 1430, and the RU 1440; the DU 1430; both the DU 1430 and the RU 1440; or the RU 1440. The CU 1410 may include at least one CU processor 1412. The CU processor (s) 1412 may include on-chip memory 1412'. In some aspects, the CU 1410 may further include additional memory modules 1414 and a communications interface 1418. The CU 1410 communicates with the DU 1430 through a midhaul link, such as an F1 interface. The DU 1430 may include at least one DU processor 1432. The DU processor (s) 1432 may include on-chip memory 1432'. In some aspects, the DU 1430 may further include additional memory modules 1434 and a communications interface 1438. The DU 1430 communicates with the RU 1440 through a fronthaul link. The RU 1440 may include at least one RU processor 1442. The RU processor (s) 1442 may include on-chip memory 1442'. In some aspects, the RU 1440 may further include additional memory modules 1444, one or more transceivers 1446, one or more antennas 1480, and a communications interface 1448. The RU 1440 communicates with the UE 104. The on-chip memory 1412', 1432', 1442' and the additional memory modules 1414, 1434, 1444 may each be considered a computer-readable medium / memory. Each computer-readable medium / memory may be non-transitory. Each of the processors 1412, 1432, 1442 is responsible for general processing, including the execution of software stored on the computer-readable medium / memory. The software, when executed by the corresponding processor (s) causes the processor (s) to perform the various functions described supra. The computer-readable medium / memory may also be used for storing data that is manipulated by the processor (s) when executing software.
[0132] As discussed supra, the candidate cell SP RS activation / deactivation MAC-CE component 199 may be configured to serve a UE via a first cell and transmit from the first cell serving the UE, a MAC-CE indicating an activation of a resource set associated with SP RS for a second cell that is a candidate for a LTM operation. The candidate cell SP RS activation / deactivation MAC-CE component 199 may be within one or more processors of one or more of the CU 1410, DU 1430, and the RU 1440. The candidate cell SP RS activation / deactivation MAC-CE component 199 may be one or more hardware components specifically configured to carry out the stated processes / algorithm, implemented by one or more processors configured to perform the stated processes / algorithm, stored within a computer-readable medium for implementation by one or more processors, or some combination thereof. When multiple processors are implemented, the multiple processors may perform the stated processes / algorithm individually or in combination. The network entity 1402 may include a variety of components configured for various functions. In one configuration, the network entity 1402 may include means for serving a user equipment (UE) via a first cell. The network entity 1402, in some aspects, may include means for transmitting from the first cell serving the UE, a medium access control (MAC) control element (CE) (MAC-CE) indicating an activation of a resource set associated with semi-persistent (SP) reference signals (RS) for a second cell that is a candidate for a lower-layer triggered mobility (LTM) operation. The network entity 1402, in some aspects, may include means for receiving a report regarding one or more of the SP RS measured at the UE via the resource set activated by the MAC-CE. The network entity 1402, in some aspects, may include means for transmitting from the first cell serving the UE, a second MAC-CE indicating a deactivation of the resource set associated with the SP RS for the second cell. The network entity 1402 may further include means for performing any of the aspects described in connection with the flowchart in FIGs. 11 and 12, and / or performed by the base station in the communication flow of FIG. 8. The means may be the candidate cell SP RS activation / deactivation MAC-CE component 199 of the network entity 1402 configured to perform the functions recited by the means. As described supra, the network entity 1402 may include the TX processor 316, the RX processor 370, and the controller / processor 375. As such, in one configuration, the means may be the TX processor 316, the RX processor 370, and / or the controller / processor 375 configured to perform the functions recited by the means.
[0133] Various aspects relate generally to a signaling design for a set one or more activation / deactivation MAC-CE (s) for semi-persistent scheduling of CSI-RS, zero-power (ZP) CSI-RS, and / or sounding reference signals (SRS) associated with candidate special cells (SpCells) , where an SpCell may include a primary cell (PCell) and a primary secondary cell (PSCell) . In some examples, a wireless device may be configured to receive, while being served by a first cell, a MAC-CE indicating an activation of a resource set associated with SP RS for a second cell that is a candidate for a LTM operation, and one of measuring or transmitting, based on the MAC-CE, signals via the resource set associated with the SP RS. In some examples, a network node such as a base station may be configured to serve a UE via a first cell and transmit from the first cell serving the UE, a MAC-CE indicating an activation of a resource set associated with SP RS for a second cell that is a candidate for a LTM operation.
[0134] Particular aspects of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. In some examples, by introducing and / or using one or more activation / deactivation MAC-CE(s) for semi-persistently scheduled CSI-RS, ZP CSI-RS, and / or SRS associated with candidate SpCells, the described techniques can be used to enhance LTM among a set of candidate SpCells.
[0135] It is understood that the specific order or hierarchy of blocks in the processes / flowcharts disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes / flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not limited to the specific order or hierarchy presented.
[0136] The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not limited to the aspects described herein, but are to be accorded the full scope consistent with the language claims. Reference to an element in the singular does not mean “one and only one” unless specifically so stated, but rather “one or more. ” Terms such as “if, ” “when, ” and “while” do not imply an immediate temporal relationship or reaction. That is, these phrases, e.g., “when, ” do not imply an immediate action in response to or during the occurrence of an action, but simply imply that if a condition is met then an action will occur, but without requiring a specific or immediate time constraint for the action to occur. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration. ” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” include any combination of A, B, and / or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. Sets should be interpreted as a set of elements where the elements number one or more. Accordingly, for a set of X, X would include one or more elements. When at least one processor (i.e., a set of one or more processors P) is configured to perform a set of functions F, each processor of P may be configured to perform a subset S of F, where Accordingly, each processor of the at least one processor may be configured to perform a particular subset of the set of functions, where the subset is the full set, a proper subset of the set, or an empty subset of the set. A processor may be referred to as processor circuitry. A memory / memory module may be referred to as memory circuitry. If a first apparatus receives data from or transmits data to a second apparatus, the data may be received / transmitted directly between the first and second apparatuses, or indirectly between the first and second apparatuses through a set of apparatuses. A device configured to “output” data or “provide” data, such as a transmission, signal, or message, may transmit the data, for example with a transceiver, or may send the data to a device that transmits the data. A device configured to “obtain” data, such as a transmission, signal, or message, may receive, for example with a transceiver, or may obtain the data from a device that receives the data. Information stored in a memory includes instructions and / or data. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are encompassed by the claims. Moreover, nothing disclosed herein is dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words “module, ” “mechanism, ” “element, ” “device, ” and the like may not be a substitute for the word “means. ” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for. ”
[0137] As used herein, the phrase “based on” shall not be construed as a reference to a closed set of information, one or more conditions, one or more factors, or the like. In other words, the phrase “based on A” (where “A” may be information, a condition, a factor, or the like) shall be construed as “based at least on A” unless specifically recited differently.
[0138] The following aspects are illustrative only and may be combined with other aspects or teachings described herein, without limitation.
[0139] Aspect 1 is a method of wireless communication at a user equipment (UE) , comprising: receiving, while being served by a first cell, a medium access control (MAC) control element (CE) (MAC-CE) indicating an activation of a resource set associated with semi-persistent (SP) reference signals (RS) for a second cell that is a candidate for a lower-layer triggered mobility (LTM) operation; and one of measuring or transmitting, based on the MAC-CE, signals via the resource set associated with the SP RS.
[0140] Aspect 2 is the method of aspect 1, wherein receiving the MAC-CE comprises receiving the MAC-CE from the first cell.
[0141] Aspect 3 is the method of any of aspects 1 and 2, wherein the MAC-CE is a first MAC-CE, the method further comprising: receiving, while being served by the first cell, a second MAC-CE indicating a deactivation of the resource set associated with the SP RS for the second cell; and omitting, based on the second MAC-CE, one of measurement or transmission of one or more subsequent signals via the resource set associated with the SP RS.
[0142] Aspect 4 is the method of any of aspects 1 to 3, wherein the SP RS comprise SP channel state information (CSI) RS (SP CSI-RS) , and wherein the one of measuring or transmitting the signals via the resource set associated with the SP CSI-RS comprises measuring the SP CSI-RS from the second cell via the resource set associated with the SP CSI-RS.
[0143] Aspect 5 is the method of aspect of any of aspects 4, wherein the MAC-CE comprises an indication of one or more of: a candidate cell identifier of the second cell; a first resource set identifier for the resource set associated with the SP CSI-RS; a second resource set identifier for an additional resource set associated with SP CSI interference measurement (SP CSI-IM) ; or one or more transmission configuration indicator (TCI) state identifiers for one or more TCI states associated with one or more of the SP CSI-RS or the SP CSI-IM.
[0144] Aspect 6 is the method of any of aspects 1 to 3, wherein the SP RS comprise SP zero power (ZP) channel state information (CSI) RS (SP ZP-CSI-RS) , wherein the one of measuring or transmitting the signals via the resource set associated with the SP ZP-CSI-RS comprises measuring the signals via the resource set associated with the SP ZP-CSI-RS, and wherein the measured signals comprise one or more signals not transmitted by the second cell.
[0145] Aspect 7 is the method of aspect of any of aspects 6, wherein the MAC-CE comprises an indication of one or more of: a candidate cell identifier of the second cell; or a resource set identifier for the resource set associated with the SP ZP-CSI-RS.
[0146] Aspect 8 is the method of any of aspects 1 to 3, wherein the SP RS comprise SP sounding reference signals (SRS) , wherein the one of measuring or transmitting the signals via the resource set associated with the SP SRS comprises transmitting the SP SRS via the resource set associated with the SP SRS.
[0147] Aspect 9 is the method of aspect of any of aspects 8, wherein the MAC-CE comprises an indication of one or more of: a candidate cell identifier of the second cell; a resource set identifier for the resource set associated with the SP SRS; or one or more transmission configuration indicator (TCI) state identifiers for one or more TCI states associated with the resource set associated with the SP SRS.
[0148] Aspect 10 is the method of any of aspects 1 to 9, wherein the MAC-CE does not comprise an identifier of a bandwidth part (BWP) associated with the resource set associated with the SP RS, and wherein measuring or transmitting the signals via the resource set associated with the SP RS comprises measuring or transmitting the signals via the resource set associated with the SP RS in a default BWP.
[0149] Aspect 11 is a method of wireless communication at a network node, comprising: serving a user equipment (UE) via a first cell; and transmitting from the first cell serving the UE, a medium access control (MAC) control element (CE) (MAC-CE) indicating an activation of a resource set associated with semi-persistent (SP) reference signals (RS) for a second cell that is a candidate for a lower-layer triggered mobility (LTM) operation.
[0150] Aspect 12 is the method of aspect 11, further comprising: receiving a report regarding one or more of the SP RS measured at the UE via the resource set activated by the MAC-CE.
[0151] Aspect 13 is the method of any of aspects 11 and 12, wherein the MAC-CE is a first MAC-CE, the method further comprising: transmitting from the first cell serving the UE, a second MAC-CE indicating a deactivation of the resource set associated with the SP RS for the second cell.
[0152] Aspect 14 is the method of any of aspects 11 to 13, wherein the SP RS comprise SP channel state information (CSI) RS (SP CSI-RS) , and wherein the MAC-CE comprises an indication of one or more of: a candidate cell identifier of the second cell; a first resource set identifier for the resource set associated with the SP CSI-RS; a second resource set identifier for an additional resource set associated with SP CSI interference measurement (SP CSI-IM) ; or one or more transmission configuration indicator (TCI) state identifiers for one or more TCI states associated with one or more of the SP CSI-RS or the SP CSI-IM.
[0153] Aspect 15 is the method of any of aspects 11 to 13, wherein the SP RS comprise SP zero power (ZP) channel state information (CSI) RS (SP ZP-CSI-RS) , wherein the MAC-CE comprises an indication of one or more of: a candidate cell identifier of the second cell; or a resource set identifier for the resource set associated with the SP ZP-CSI-RS.
[0154] Aspect 16 is the method of any of aspects 11 to 13, wherein the SP RS comprise SP sounding reference signals (SRS) , wherein the MAC-CE comprises an indication of one or more of: a candidate cell identifier of the second cell; a resource set identifier for the resource set associated with the SP SRS; or one or more transmission configuration indicator (TCI) state identifiers for one or more TCI states associated with the resource set associated with the SP SRS.
[0155] Aspect 17 is the method of any of aspects 11 to 16, wherein the MAC-CE does not comprise an identifier of a bandwidth part (BWP) associated with the resource set associated with the SP RS, and wherein the MAC-CE is associated with a default BWP.
[0156] Aspect 18 is an apparatus for wireless communication at a UE, comprising: at least one memory; and at least one processor coupled to the at least one memory, the at least one processor is configured to perform the method of any of aspects 1 to 10.
[0157] Aspect 19 is an apparatus for wireless communication at a UE, comprising means for performing each step in the method of any of aspects 1 to 10.
[0158] Aspect 20 is the apparatus of any of aspects 18 to 19, further comprising a transceiver configured to receive or to transmit in association with the method of any of aspects 1 to 10.
[0159] Aspect 21 is a computer-readable medium storing computer executable code at a UE, the code when executed by at least one processor causes the at least one processor to perform the method of any of aspects 1 to 10.
[0160] Aspect 22 is an apparatus for wireless communication at a network node, comprising: at least one memory; and at least one processor coupled to the at least one memory, the at least one processor is configured to perform the method of any of aspects 11 to 17.
[0161] Aspect 23 is an apparatus for wireless communication at a network node, comprising means for performing each step in the method of any of aspects 11 to 17.
[0162] Aspect 24 is the apparatus of any of aspects 22 to 23, further comprising a transceiver configured to receive or to transmit in association with the method of any of aspects 11 to 17.
[0163] Aspect 25 is a computer-readable medium storing computer executable code at a network node, the code when executed by at least one processor causes the at least one processor to perform the method of any of aspects 11 to 17.
Claims
1.An apparatus for wireless communication at a user equipment (UE) , comprising:at least one memory; andat least one processor coupled to the at least one memory and, based at least in part on information stored in the at least one memory, the at least one processor is configured to:receive, while being served by a first cell, a medium access control (MAC) control element (CE) (MAC-CE) indicating an activation of a resource set associated with semi-persistent (SP) reference signals (RS) for a second cell that is a candidate for a lower-layer triggered mobility (LTM) operation; andone of measure or transmit, based on the MAC-CE, signals via the resource set associated with the SP RS.2.The apparatus of claim 1, wherein to receive the MAC-CE, the at least one processor, individually or in any combination, is configured to receive the MAC-CE from the first cell.3.The apparatus of claim 1, wherein the MAC-CE is a first MAC-CE, the apparatus further comprising a transceiver coupled to the at least one processor, the transceiver being configured to:receive, while being served by the first cell, a second MAC-CE indicating a deactivation of the resource set associated with the SP RS for the second cell; andomit, based on the second MAC-CE, one of measurement or transmission of one or more subsequent signals via the resource set associated with the SP RS.4.The apparatus of claim 1, wherein the SP RS comprise SP channel state information (CSI) RS (SP CSI-RS) , and wherein to one of measure or transmit the signals via the resource set associated with the SP CSI-RS, the at least one processor, individually or in any combination, is configured to measure the SP CSI-RS from the second cell via the resource set associated with the SP CSI-RS.5.The apparatus of claim 4, wherein the MAC-CE comprises an indication of one or more of:a candidate cell identifier of the second cell;a first resource set identifier for the resource set associated with the SP CSI-RS;a second resource set identifier for an additional resource set associated with SP CSI interference measurement (SP CSI-IM) ; orone or more transmission configuration indicator (TCI) state identifiers for one or more TCI states associated with one or more of the SP CSI-RS or the SP CSI-IM.6.The apparatus of claim 1, wherein the SP RS comprise SP zero power (ZP) channel state information (CSI) RS (SP ZP-CSI-RS) , wherein to one of measure or transmit the signals via the resource set associated with the SP ZP-CSI-RS, the at least one processor, individually or in any combination, is configured to measure the signals via the resource set associated with the SP ZP-CSI-RS, and wherein the measured signals comprise one or more signals not transmitted by the second cell.7.The apparatus of claim 6, wherein the MAC-CE comprises an indication of one or more of:a candidate cell identifier of the second cell; ora resource set identifier for the resource set associated with the SP ZP-CSI-RS.8.The apparatus of claim 1, wherein the SP RS comprise SP sounding reference signals (SRS) , wherein to one of measure or transmit the signals via the resource set associated with the SP SRS, the at least one processor, individually or in any combination, is configured to transmit the SP SRS via the resource set associated with the SP SRS.9.The apparatus of claim 8, wherein the MAC-CE comprises an indication of one or more of:a candidate cell identifier of the second cell;a resource set identifier for the resource set associated with the SP SRS; orone or more transmission configuration indicator (TCI) state identifiers for one or more TCI states associated with the resource set associated with the SP SRS.10.The apparatus of claim 1, wherein the MAC-CE does not comprise an identifier of a bandwidth part (BWP) associated with the resource set associated with the SP RS, and wherein to one of measure or transmit the signals via the resource set associated with the SP RS, the at least one processor, individually or in any combination, is configured to measure or transmit the signals via the resource set associated with the SP RS in a default BWP.11.An apparatus for wireless communication at a network node, comprising:at least one memory; andat least one processor coupled to the at least one memory and, based at least in part on information stored in the at least one memory, the at least one processor is configured to:serve a user equipment (UE) via a first cell; andtransmit from the first cell serving the UE, a medium access control (MAC) control element (CE) (MAC-CE) indicating an activation of a resource set associated with semi-persistent (SP) reference signals (RS) for a second cell that is a candidate for a lower-layer triggered mobility (LTM) operation.12.The apparatus of claim 11, further comprising a transceiver coupled to the at least one processor, the transceiver being configured to:receive a report regarding one or more of the SP RS measured at the UE via the resource set activated by the MAC-CE.13.The apparatus of claim 11, wherein the MAC-CE is a first MAC-CE, wherein the at least one processor, individually or in any combination, is further configured to:transmit from the first cell serving the UE, a second MAC-CE indicating a deactivation of the resource set associated with the SP RS for the second cell.14.The apparatus of claim 11, wherein the SP RS comprise SP channel state information (CSI) RS (SP CSI-RS) , and wherein the MAC-CE comprises an indication of one or more of:a candidate cell identifier of the second cell;a first resource set identifier for the resource set associated with the SP CSI-RS;a second resource set identifier for an additional resource set associated with SP CSI interference measurement (SP CSI-IM) ; orone or more transmission configuration indicator (TCI) state identifiers for one or more TCI states associated with one or more of the SP CSI-RS or the SP CSI-IM.15.The apparatus of claim 11, wherein the SP RS comprise SP zero power (ZP) channel state information (CSI) RS (SP ZP-CSI-RS) , wherein the MAC-CE comprises an indication of one or more of:a candidate cell identifier of the second cell; ora resource set identifier for the resource set associated with the SP ZP-CSI-RS.16.The apparatus of claim 11, wherein the SP RS comprise SP sounding reference signals (SRS) , wherein the MAC-CE comprises an indication of one or more of:a candidate cell identifier of the second cell;a resource set identifier for the resource set associated with the SP SRS; orone or more transmission configuration indicator (TCI) state identifiers for one or more TCI states associated with the resource set associated with the SP SRS.17.The apparatus of claim 11, wherein the MAC-CE does not comprise an identifier of a bandwidth part (BWP) associated with the resource set associated with the SP RS, and wherein the MAC-CE is associated with a default BWP.18.A method of wireless communication at a user equipment (UE) , comprising:receiving, while being served by a first cell, a medium access control (MAC) control element (CE) (MAC-CE) indicating an activation of a resource set associated with semi-persistent (SP) reference signals (RS) for a second cell that is a candidate for a lower-layer triggered mobility (LTM) operation; andone of measuring or transmitting, based on the MAC-CE, signals via the resource set associated with the SP RS.19.The method of claim 18, wherein the MAC-CE is a first MAC-CE, the method further comprising:receiving, while being served by the first cell, a second MAC-CE indicating a deactivation of the resource set associated with the SP RS for the second cell; andomitting, based on the second MAC-CE, one of measurement or transmission of one or more subsequent signals via the resource set associated with the SP RS.20.The method of claim 18, wherein the SP RS comprise one of:SP channel state information (CSI) RS (SP CSI-RS) , and the one of measuring or transmitting the signals via the resource set associated with the SP CSI-RS comprises measuring the SP CSI-RS from the second cell via the resource set associated with the SP CSI-RS;SP zero power (ZP) channel state information (CSI) RS (SP ZP-CSI-RS) , and the one of measuring or transmitting the signals via the resource set associated with the SP ZP-CSI-RS comprises measuring the signals via the resource set associated with the SP ZP-CSI-RS, wherein the measured signals comprise one or more signals not transmitted by the second cell; orSP sounding reference signals (SRS) , and the one of measuring or transmitting the signals via the resource set associated with the SP SRS comprises transmitting the SP SRS via the resource set associated with the SP SRS.